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This is a continuation of application Ser. No. 07/672,020, filed Mar. 19, 1991, now abandoned. FIELD OF THE INVENTION This invention relates to aminoalcohols and their derivatives as penetration-enhancers for pharmaceutical, agricultural and cosmetic agents. BACKGROUND OF THE INVENTION Many physiologically active agents are best applied topically to obtain desirable results. Topical application, in the form of creams, lotions, gels, solutions, etc., largely avoids side effects of the agents and permits high level concentrations of the agents. Some therapeutic drugs may also be administered for systemic use through the skin or other body membranes including intranasal and intravaginal application of humans and other animals, utilizing a transdermal device or formulated in a suppository or aerosol spray. For some years, pharmaceutical researchers have sought an effective means of introducing drugs into the bloodstream by applying them to the unbroken skin. Among other advantages, such administration can provide a comfortable, convenient and safe way of giving many drugs now taken orally or infused into veins or injected intramuscularly. Using skin as the portal for drug entry offers unique potential, because transdermal delivery permits close control over drug absorption. For example, it avoids factors that can cause unpredictable absorption from gastrointestinal tract, including changes in acidity, motility, and food content. It also avoids initial metabolism of the drug by the liver known as the first pass effect. Thus, controlled drug entry through skin can achieve a high degree of control over blood concentrations of drug. Close control over drug concentration in blood can translate readily into safer and more comfortable treatment. When a drug's adverse effects occur at higher concentrations than its beneficial ones, rate control can maintain the concentration that evoke only--or principally the drug's desired actions. This ability to lessen undesired drug actions can greatly reduce the toxicity hazards that now restrict or prevent the use of many valuable agents. Transdermal delivery particularly benefits patients with chronic disease. Many such patients have difficulty following regimens requiring several doses daily of medications that repeatedly cause unpleasant symptoms. They find the same drugs much more acceptable when administered in transdermal system that require application infrequently--in some cases, only once or twice weekly and reduce adverse effects. Transdermal delivery is feasible for drugs effective in amounts that can pass through the skin area and that are substantially free of localized irritating or allergic effects. While these limitations may exclude some agents, many others remain eligible for transdermal delivery. Moreover, their numbers will expand as pharmaceutical agents of greater potency are developed. Particularly suitable for transdermal delivery are potent drugs with only a narrow spread between their toxic and safe blood concentrations, those having gastrointestinal absorption problems, those susceptible to a higher first pass liver metabolism or those requiring frequent dosing in oral or injectable form. Transdermal therapy permits much wider use of natural substances such as hormones. Often the survival times of these substances in the body are so short that they would have to be taken many times daily in ordinary dosage forms. Continuous transdermal delivery provides a practical way of giving them, and one that can mimic the body's own patterns of secretion. At present, controlled transdermal therapy appears feasible for many drugs used for a wide variety of ailments including, but not limited to, circulatory problems, hormone deficiency, respiratory ailments, and pain relief. Percutaneous administration can have the advantage of permitting continuous administration of drug to the circulation over prolonged periods of time to obtain a uniform delivery rate and blood level of drug. Commencement and termination of drug therapy are initiated by the application and removal of the dosing devices from the skin. Uncertainties of administration through the gastrointestinal tract and the inconvenience of administration by injection are eliminated. Since a high concentration of drug never enters the body, problems of pulse entry are overcome and metabolic half-life is not a factor of controlling importance. The greatest problems in applying physiologically active agents topically or transdermally is that the skin is an effective barrier to penetration. The epidermis of the skin has an exterior layer of dead cells called the stratum corneum which is tightly compacted and oily and which provides an effective barrier against gaseous, solid or liquid chemical agents, whether used alone or in water or in oil solutions. If a physiologically active agent penetrates the stratum corneum, it can readily pass through the basal layer of the epidermis and into the dermis. Although the effectiveness of the stratum corneum as a barrier provides great protection, it also frustrates efforts to apply beneficial agents directly to local areas of the body. The inability of physiologically active agents to penetrate the stratum corneum prevents their effective use of treating such conditions as inflammation, acne, psoriasis, herpes labialis, herpes genitalis, eczema, infections caused by fungi, viruses and other microorganisms, or or, her disorders or conditions of the skin or mucous membranes or of conditions beneath the exterior surface of the skin or mucous membranes. The stratum corneum also prevents the skin from absorbing and retaining cosmetic-type materials such as sunscreens, perfumes, mosquito repellents and the like. Physiologically active agents may be applied to the locally affected parts of the body in the form of a solution, cream, lotion or gel utilizing the vehicle system described herein. These agents may also be delivered for systemic use utilizing the vehicle system in a transdermal patch. Vehicles such as USP cold cream, ethanol and various ointments, oils, solvents and emulsions have been used heretofore to apply physiologically active ingredients locally. Most such vehicles are not effective to carry significant amounts of physiologically active agents into and through the skin. One such vehicle is dimethyl sulfoxide, which is described in U.S. Pat. No. 3,551,554. My previous inventions disclosed in U.S. Patent Nos. 3,989,816; 3,991,203; 4,122,170; 4,316,893; 4,405,616; 4,415,563; 4,423,040; 4,424,210; 4,444,762; 4,837,026 and 4,876,249 describe a method for enhancing the topical or transdermal administration of physiologically active agents by combining such an agent with an effective amount of a penetration enhancer and applying the combination to skin or other body membranes of humans or animals, in the form of solution, cream, gel, lotion, or a transdermal device. My related U.S. Patent Nos. 4,461,638 and 4,762,549 describe a method for enhancing delivery of plant nutrients and plant growth regulators, and my U.S. Pat. No. 4,525,199 describes an improved method of pest control by enhancing pesticide permeation. My related U.S. application, Ser. No. 218,316, filed on Jul. 12, 1988, describes a method for enhancing topical and transdermal administration of physiologically active agents with membrane penetration enhancers selected from oxazolidone and related heterocyclic compounds. My related U.S. application Set. No. 07/348,387, filed on May 8, 1989 describes a method for enhancing topical and transdermal administration of physiologically active agents with yet another series of membrane penetration enhancers. My related U.S. applications Ser. No. 07/393,584, filed on Aug. 11, 1989 and Set. No. 07/451,124, filed on Dec. 15, 1989, C.I.P.s of U.S. patent application Ser. No. 002,387, filed on Jan. 12, 1987, now U.S. Pat. No. 4,876,249, describe a method for enhancing topical and transdermal administration of physiologically active agents with membrane penetration enhancers selected from heterocyclic compounds containing two heteroatoms. Penetration enhancers for enhancing systemic administration of therapeutic agents transdermally disclosed in the art include dodecyl pyrrolidone, dimethyl lauramide, dimethyl sulfoxide, decyl methyl sulfoxide, ethanol, 1-dodecylhexahydro-2H-azepin-2-one, 1-dodecanoyl hexamethylenimine, 2-nonyl-1,3-dioxolane, fatty acids and their esters, sucrose esters etc. These agents may be used prior to or concurrently with administration of the active agent, see, e.g., U.S. Pat. Nos. 4,031,894; 3,996,934 and 3,921,636. SUMMARY OF THE INVENTION One of the main function of the epidermis is the production of a cohesive, relatively impermeable outer sheath. It has been known that from the time an epidermal cell leaves the basal layer to the time it is desquamated, the cell lipids change both qualitatively and quantitatively. A phospholipid is the most abundant lipid class in basal cell, whereas half of the lipid in a desquamated cell consists of ceramide. The lipid content of desquamated stratum corneum cell is approximately six time that of basal cell. The change in lipid composition of a cell undergoing cornification results mainly from de nuvo synthesis of cholesterol, fatty acid and ceramide. This invention relates to penetranion enhancers closely related to the constituents of the epidermal outer sheath and therefore interact with it without irreversible disruption of the barrier. Moreover, these enhancers possess an advantage that they are expected to yield nontoxic, pharmacologically inert metabolites after passage through the skin and the systemic circulation. The invention further relates to compositions for carrying physiologically active agents through body membranes such as skin and mucosa for retaining these agents in the body tissues and further relates to a method of administering systemically and locally active agents through the skin or other body membranes of humans and animals, utilizing a transdermal device or formulation, containing an effective, non-toxic amount of a membranae penetration enhancer having the structural formula I: ##STR2## wherein: R is selected from H, and an aliphatic hydrocarbon group with from about i to about 20 carbon atoms, optionally containing a heteroatom in the hydrocarbon chain; R1 is selected from H, OH or O-CO-RS, where R5 is an aliphatic hydrocarbon group with from about 1 to about 18 carbon atoms; R2 is selected from H, a lower aliphatic hydrocarbon group, acyl, hydroxyacyl or alkoyloxyacyl group with up to about 40 carbon atoms; R3 is selected from H, an aliphatic hydrocarbon group, with up to about 16 carbon atoms unsubstituted or substituted with hydroxy, acyloxy or alkylthio or an aryl or aralkyl group; and R4 is H or an acyl group with from about 1 to about 18 carbon atoms; or when R1 is OH 1 R1and R4 are combined to form compounds having a 1,3 -dioxane ring, ##STR3## wherein, R6 and R7 are selected from H, an aliphatic hydrocarbon group unsubstituted or substituted with hydroxy, acyloxy, or carboalkoxy, or an aryl group, or they may combine to form a carbonyl group, or a physiologically acceptable salt thereof. It is understood that the aliphatic hydrocarbon groups in the substituents R-R7 may be straight or branched and saturated or unsaturated, such as straight or branched chained alkyl, alkenyl or alkinyl groups. In the substituents where the hydrocarbon group may contain a heteroatom (R), this heteroatom usually is S or O. It will be readily appreciated by those skilled in the art that certain compounds represented by formula I may exhibit optical and geometric isomerism. However, where no designation of isomers is specified with respect to the compounds of this invention, it is to be understood that all possible stereoisomers and geometric isomers (E and Z), and racemic and optically active compounds are included. It will also be readily appreciated by those skilled in the art that certain of the compounds described in the disclosure may form salts with carboxylic and mineral acids and it is understood that all such salts, in particular the physiologically acceptable salts, are included in the invention. In one preferred embodiment of I, R is an alkyl group with from 1 to 20 carbon atoms, R1 and R3 are H, R2 is an acyl group with from 1 to 30 carbon atoms and R4 is an acyl group with from 1 to 18 carbon atoms. In another preferred embodiment of I, R1 is -O-CO-R5, wherein R5 is an alkyl group with from 1 to 18 carbon atoms and R, R2, R3 and R4 are as defined above. Yet in another preferred embodiment of I, R1 is OH, R2 is H or acyl, R3 and R4 are H and R1 and R4 are combined to form a 1,3-dioxane ring and R, R6 and R7 are as defined above. Yet in another preferred embodiment of I, R1 is OH, R2 is H or acyl, R3 is alkyl, aryl, aralkyl, hydroxyalkyl, acyloxyalkyl or alkylthioalkyl, R and R4 are H and R1 and R4 are combined to form a 1,3-dioxane ring, wherein R6 and R7 are as defined above. It has been found that the physiologically active agents are carried through body membranes by the claimed penetration enhancers and are retained in the body tissue when applied topically in form of a cream, gel, or lotion or absorbed systemically when applied in the form of a transdermal device or formulation, for example, as a transdermal patch, a rectal or vagina suppository, as a nasal spray or when incorporated in a vaginal sponge or tampon. This invention also relates to the problems such as skin irritation and skin sensitization that are commonly associated with conventional penetration enhancers found in the prior art. Since the compounds of this invention are structurally closely related to the ceramides, the lipids primarily present in the top layers of the skin, it is believed that skin irritation and skin sensitization can be avoided significantly with the use of these compounds as enhancers in the therapeutic compositions. The invention further relates the penetration enhancers themselves and their method of making. DETAILED DESCRIPTION OF THE INVENTION Typical examples of compounds included in the foregoing formula I of this invention are the following: 1) 2-Ethanoylaminododecyl ethanoate 2) 2-Octanoylaminododecyl octanoate 3) 2-Octadec-9-enoylaminododecyl octadec-9-enoate 4) 2-Octadec-9-enoylaminododecyl ethanoate 5) 2-Octadecanoylaminooctadec-4-enyl-1,3-diethanoate 6) 2-Ethanoylaminooctadec-4-enyl 1,3-diethanoate 7) 2-Ethanoylaminooctadecyl 1,3-diethanoate 8) 5-Amino-2,2-dimethyl-4-(pentadec-1-enyl)-1,3-dioxane 9) 5-Amino-2,2-dimethyl-4-pentadecyl-1,3-dioxane 10) 5-Amino-4-(pentadec-1-enyl)-1,3-dioxan-2-one 11) 5-amino-4-dodecyl-1,3-dioxan-2-one 12) 4-Dodecyl-5-ethanoylamino-1,3-dioxan-2-one 13) 2-Ethanoylaminododecyl octadec-9-enoate 14) 2-Ethanoylamino-3-octadecyloxypropyl ethanoate 15) 5 -Amino-2,2-dimethyl-4-(2,6,10,14 -tetramethylpentadecyl)-1,3-dioxane 16) 5-Amino-2,2-dimethyl-4-(2,6-dimethyl-5-heptenyl)-1,3-dioxane 17) 5-amino-5-ethyl-2-undecyl-1,3-dioxane 18) 5-amino-2,2-dimethyl-5-undecyl-1,3-dioxane 19) 2,2-Dimethyl-5-dodecanoylamino-5-ethyl-1,3-dioxane 20) 5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 21) 5-Amino-5-hydroxymethyl-2-(3-heptyl)-1,3-dioxane 22) 5-Amino-5-ethyl-2-carbobutoxyethyl-2-methyl-1,3-dioxane 23) 5-Dodecanoylamino-5-methyl-1,3-dioxan-2-one 24) 5-Amino-5-undecyl-1,3-dioxan-2-one. The following compounds, encompassed by general formula I of this invention are known in the literature. The 4E,2S,3R isomer of compound 6 is the triacetyl derivative of naturally occurring D-erythro-Sphingosine and has been synthesized by Findeis and Whitesides, J. Org. Chem. 52, 2838 (1987); Julina et. al. Helv. Chim. Acta 69, 368 (1986) and references cited therein; Schmidt and Zimmermann, Tet. Lett. 27, 481 (1986). The 2-octadecanoylamino 2S,3R 1,3-diol derivative of compound 5, a ceramide, has been synthesized by Julina et. al., loc. cit. Compound 7 is the dihydro derivative of compound 6 and the 2S,3R isomer has been prepared by Roush and Adam, J. Org. Chem. 50, 3752 (1985). The E isomer of the 4R,5S stereoisomers of compounds 8 and its corresponding 1-heptadecenyl analog have been synthesized, Hasegawa and Kiso, JPN. Kokai Tokyo Koho JP 62,207,247 [87,207,247], 11 Sep 1987, C.A., 108:P167212 (1988), Hino et. al. J. Chem. Soc. Perkin Trans. I, 1687 (1986) and both E and Z isomers have been prepared by Kiso et. al., Carbohydr. Res. 158, 101 (1986) and J. Carbohydr. Chem. 5, 335 (1986). 4R,5S isomer of Compound 9 have been prepared by Nakagawa et. al., Tet. Lett. 6281 (1987) during the synthesis of Cerebroside B1 b . and Saitoh et. al. Bull. Chem. Soc. Japan, 54, 488 (1981), who also prepared the 4-[(Z)-3pentadecenyl]analog of Compound 8 during the total synthesis of two prosopis alkaloids. Compounds 15 and 16 have been prepared by Umemura and Mori, Agric. Biol. Chem., 46, 1797 (1982) as intermediates in the synthesis of spinghosine analogs. Compound 17 and related 5-amino-1,3-dioxanes have been prepared by Senkus, J. Amer. Chem. Soc. 63, 2635 (1941), ibid., 65, 1656 (1943) and U.S. Pat. Nos. 2,247,256, 2,260,265, 2,370,586, 2,383,622, 2,399,068 and evaluated as coating compounds, as intermediates for the preparation of insecticides and surface active agents and as insecticides, U.S. Pat. No. 2,485,987 and by CIBA Ltd., Fr. 1,457,767, as intermediates in the preparation of isonitriles useful as insecticides, acaricides, ovicides, herbicides, fungicides, bactericides, and molluscicides. Robinette, U.S. Pat. Nos. 2,317,555, 2,320,707 and 2,346,454, has studied the 5-amino-1,3-dioxanes as wetting, penetrating & cleansing agents for various textile and leather treatments. The 2-unsubstituted analog of Compound 19 has been utilized by Tucker, U.S. Patent No. 2,527,078, as an ingredient in detergent mixture for inhibiting the precipitation of lime soaps. Compound 20, 21 and analogs have been prepared and investigated by Senkus for insecticidal properties. Compound 22 has been prepared by Morey, U.S. Pat. No. 2,415,021. Aliphatic substituted 1,3-dioxacycloalkanes, without the prerequisite amino or substituted amino functionality of this invention, have been disclosed as skin penetration enhancers by Samour and Daskalakis, Eur. Pat. Appl. EP 268,460, 25 May 1988 and particularly, 2-nonyl-1,3-dioxolane, Proceed. Intern. Symp. Control Rel. Bioact. Mater. 17, 415 (1990) and references cited therein. To my knowledge the other compounds are novel. The use of the compounds of the present invention as penetration enhancers in drug delivery is, however, novel and not predictable from the prior art. The aminoalcohol derivatives covered by the general formula I may be prepared by any of the processes known in the literature, and are hereby incorporated by reference. For example, Ohashi et. al., Tet. Lett. 29, 1185 (1988); Findeis and Whitesides, J. Org. Chem. 52, 2838 (1987); Nakagawa et. al., Tet. Lett. 6281 (1987); Hino et. al., J. Chem. Soc. Perkin Trans. I, 1687 (1986); Koike et. al., Carbohydr. res. 158, 113 (1986), Kiso et. al., Carbohydr. Res. 158, 101 (1986) and J. Carbohydr. Chem. 5, 335 (1986); Schmidt and Zimmermann, Tet. Lett. 481 (1986); Julina et. al. Helv. Chim. Acta 69, 368 (1986); Roush and Adam, J. Org. Chem. 50, 3752 (1985); Bernet and Vasella, Tet. Lett. 24, 5491 (1983); Chandrakumar and Hajdu, J. Org. Chem. 48, 1197 (1983); Garigipati and Weinreb, J. Amer. Chem. Soc. 105, 4499 (1983); Schmidt and Klaeger, Angew. Chem. Suppl. 393 (1982) and Angew. Chem. Int. Ed. 21, 982 (1982); Umemura and Mori, Agric. Biol. Chem. 46, 1797 (1982); Saitoh et. al., Bull. Chem. Soc. Japan 54, 488 (1981); Newman, J. Amer. Chem. Soc.95, 4098 (1973) and Shapiro et. al., J. Amer. Chem. Soc. 80, 1194 (1958). In addition, the acetal and ketal derivatives of 5-amino-1,3-dioxane can be prepared from the nitro alcohols according to the methods of Senkus mentioned earlier and the corresponding 2-oxo derivatives by processes known for carbonyl group insertion,such as those outlined in my pending U.S. application Ser. No. 218,316, filed on Jul. 12, 1988, followed by hydrogenation of the nitro group. 5-Acylamino-1,3-dioxanes can be easily prepared by acylation of the 5=amino compounds with an appropriate carboxylic acid derivative according to the well established methods in the literature. 5-Amino-1,3-dioxanes with other substituents in 2-position can be prepared by the treatment of the said nitro alcohols with compounds containing a carbonyl group and the desired functionality, for example, with butyl levulinate as outlined by Morey. Other amino alcohols can be prepared as outlined in my pending U.S. application Ser. No. 218,316, filed on Jul. 12, 1988 and derivatized to compounds of formula I. The compounds of the present invention may be used as penetration enhancers in the same manner as described in my U.S. Pat. Nos. 3,989,816; 3,991,203; 4,415,563; 4,122,170; 4,316,893; 4,405,616; 4,415,563; 4,423,040; 4,424,210; 4,444,762; 4,837,026 4,876,249 and U.S. applications Ser. No. 218,316, filed on Jul. 12, 1988; Ser. No. 07/348,387 filed May 8, 1989; Ser. No. 07/393,584, filed Aug. 11, 1989, and Ser. No. 07/451,124, filed on Dec. 15, 1989, which are hereby incorporated by reference. The compounds of the present invention are useful as penetration enhancers for a wide range of physiologically active agents and the compositions disclosed herein are useful for topical and transdermal therapeutic application of these agents. Typically systemically active agents which may be delivered transdermally are therapeutic agents which are sufficiently potent such that they can be delivered through the skin or other membranes to the bloodstream in sufficient quantities to produce the desired therapeutic effect. In general this includes agents in all of the major therapeutic areas including, but not limited to, anti-infectives, such as antibiotics and antiviral agents, analgesics and analgesics combinations, anorexics, anthelmintics, antiarthritics, antiasthma agents, anticonvul sants, antidepressants, antidiabetic agents, antidiarrheals, antihistamines, anti-inflammatory agents, antimigraine preparations, antimotion sickness, antinauseants, antineoplastics, antiparkinsonism drugs, antipruritics, antipsychotics, antipyretics, antispasmodics, including gastrointestinal and urinary; anticholinergics, sympathomimetics, xanthine derivatives, cardiovascular preparations including calcium channel blockers, beta-blockers, antiarryhthmics, antihypertensives, diuretics, vasodilators including general, coronary, peripheral and cerebral; central nervous system stimulants, cough and cold preparations, decongestants, diagnostics, hormones, hypnotics, immunosuppressives, muscle relaxants, parasympatholytics, parasympathomimetics, sedatives, tranquilizers and antiosteoporos is agents. The subject compositions are also useful for topical application of many physiologically active agents in combination with the compounds of this invention. Fungistatic and fungicidal agents such as, for example, thiabendazole, chloroxine, amphotericin, candicidin, fungimycin, nystatin, chlordantoin, clotrimazole, miconazole and related imidazole antifungal agents, pyrrolnitrin, salicylic acid, fezatione, ticlatone, tolnaftate, triacetin and zinc and sodium pyrithione may be combined with the compounds described herein and topically applied to affected areas of the skin. For example, fungistatic or fungicidal agents so applied are carried through the stratum corneum, and thereby successfully treat fungus-caused skin problems. These agents, thus applied, not only penetrate more quickly, but additionally enter the animal tissue in high concentrations and are retained for substantially longer time periods whereby a far more successful treatment is effected. For example, the subject composition may also be employed in the treatment of fungus infections on the skin caused by candida and dermatophytes which cause athletes foot or ringworm, by incorporating thiabendazole or similar antifungal agents with one of the enhancers and applying it to the affected area. The subject compositions are also useful in treating skin problems, such as for example, those associated with the herpes viruses, which may be treated with a cream of iododeoxyuridine or acyclovir in combination with one of the enhancers, or such problems as warts which may be treated with agents such as podophylline combined with one of the enhancers. Skin problems such as psoriasis may be treated by topical application of a conventional topical steroid formulated with one of the enhancers or by treatment with methotrexate incorporated with one of the enhancers of this invention. Scalp conditions such as alopecia arcata may be treated more effectively by applying agents such as minoxidil in combination with one of the enhancers of this invention directly to the scalp. The subject compositions are also useful for treating mild eczema, for example, by applying a formulation of Fluocinolone acetonide or its derivatives; hydrocortisone or triamcinolone acetonide incorporated with one of the enhancers to the affected area. Examples of other physiologically active steroids which may be used with the enhancers include corticosteroids such as, for example, cortisone, cortodoxone, flucetonide, fludrocortisone, difluorasone diacetate, flurandrenolone acetonide, medrysone, amcinafel, amcinafide, betamethasone and its esters, chloroprednisone, clocorelone, descinolone, desonide, dexamethasone, dichlorisone, difluprednate, flucloronide, flumethasone, flunisolide, fluocinonide, flucortolone, fluoromethalone, fluperolone, fluprednisolone, meprednisone, methylmeprednisolone, paramethasone, prednisolone and prednisone. The subject compositions are also useful in antibacterial chemotherapy, e.g. in the treatment of skin conditions involving pathogenic bacteria. Typical antibacterial agents which may be used in this invention include sul fonamides, penicillins, cephalosporins, erythromycins, lincomycins, vancomycins, tetracyclines, chloramphenicols, streptomycins, etc. Typical examples of the foregoing include erythromycin, erythromycin ethyl carbonate, erythromycin estolate, erythromycin glucepate, erythromycin ethylsuccinate, erythromycin lactobionate, lincomycin, clindamycin, tetracycline, chlortetracycline, demeclocycline, doxycycline, methacycline, oxtcetracycline, minocycline, etc. The subject compositions are also useful in protecting ultra-sensitive skin or even normally sensitive skin from damage or discomfort due to sunburn. Thus, actinic dermatitis may be avoided by application of a sunscreen, such as PABA or its well known derivatives or benzophenones in combination with one of the enhancers, to skin surfaces that are to be exposed to the sun; and the protective agent will be carried into the stratum comeurn more successfully and will therefore be retained even when exposed to water or washing for a substantially longer period of time than when applied to the skin in conventional vehicles. This invention is particularly useful for ordinary suntan lotions used in activities involving swimming because the ultraviolet screening ingredients in the carriers are washed off the skin when it is immersed in water. The subject compositions may also find use in treating scar tissue by applying agents which soften collagen, such as aminopropionitrile or penicillamine combined with one of the enhancers of this invention topically to the scar tissue. Agents normally applied as eye drops, ear drops, or nose drops are more effective when combined with the enhancers of this invention. Agents used in the diagnosis may be used more effectively when applied in combination with one of the enhancers of this invention. Patch tests to diagnose allergies may be effected promptly without scratching the skin or covering the area subjected to an allergen when the allergens are applied with one of the enhancers of this invention. The subject compositions are also useful for topical application of cosmetic or esthetic agents. For example, compounds such as melanin-stimulating hormone (MSH) or dihydroxyacetone and the like are more effectively applied to the skin to simulate a suntan when they are used in combination with one of the enhancers of this invention. Depigmenting agents, such as hydroquinone, which bleach and lighten hyperpigmented skin are more effective when combined with one of the enhancers of this invention. Hair dyes also penetrate more completely and effectively when incorporated with enhancers of this invention. These enhancers are also useful in the compositions containing skin moisturizing agents. The effectiveness of such topically applied materials as insect repellants or fragrances, such as perfumes and colognes, can be prolonged when such agents are applied in combination with the vehicles of this invention. It is to be emphasized that the foregoing are simply examples of physiologically active agents including therapeutic and cosmetic agents having known effects for known conditions, which may be used more effectively for their known properties in accordance with this invention. The term "physiologically active agent" is used herein to refer to a broad class of useful chemical and therapeutic agents including physiologically active steroids, antibiotics, anti-fungal agents, antibacterial agents, antineoplastic agents, allergens, antiinflammatory agents, antiemetics, antipruritic agents, antihistaminic agents, vasodilators, expectorants, analgesics, antiosteoporosis agents, sunscreen compounds, antiacne agents, collagen softening agents and other similar compounds. Cosmetic agents, hair and skin dyes, natural and synthetic hormones, perfumes, insect repellents, diagnostic agents and other such compounds may also be advantageously formulated with these penetration enhancers. In addition, these membrane penetration enhancers may be used in transdermal applications in combination with ultrasound and iontophoresis. Moreover, these penetration enhancers are useful in agriculture in the application of fertilizers, hormones, growth factors including micronutrients, insecticides, molluscicides, arachides, nematocides, rodenticides, herbicides, and other pesticides to plants, animals and pests. These penetration enhancers are also useful for penetration of micronutrients and chemical hybridization agents in seeds for enhanced plant growth. Of course, the appropriate dosage levels of all the physiologically active agents, without conjoint use of the penetration enhancing compounds of formula I, are known to those of ordinary skill in the art. These conventional dosage levels correspond to the upper range of dosage levels for compositions including a physiologically active agent and a compound of formula I as a penetration enhancer. However, because the delivery of the active agent is enhanced by compounds of the present invention, dosage levels significantly lower than conventional dosage levels may be used with success. Systemically active agents are used in amounts calculated to achieve and maintain therapeutic blood levels in a human or other animal over the period of time desired. (The term "Animal" as used here encompasses humans as well as other animals, including particularly pets and other domestic animals.) These amounts vary with the potency of each systemically active substance, the amount required for the desired therapeutic or other effect, the rate of elimination or breakdown of the substance by the body once it has entered the bloodstream and the amount of penetration enhancer in the formulation. In accordance with conventional prudent formulating practices, a dosage near the lower end of the useful range of a particular agent is usually employed initially and the dosage increased or decreased as indicated from the observed response, as in the routine procedure of the physician. The present invention contemplates compositions of compounds of formula I, together with physiologically active agents from 0.05% to 100% of conventional dosage levels. The amount of compound of Formula I which may be used in the present invention is an effective, non-toxic amount for enhancing percutaneous absorption. Generally, for topical use the amount ranges between 0.1 to about 10 and preferably about 0.1 to 5 percent by weight of the composition. For transdermal enhancement of systemic agents, the amount of penetration enhancer which may be used in the invention varies from about 1 to 100 percent although adequate enhancement of penetration is generally found to occur in the range of about 1 to 30 percent by weight of the formulation to be delivered. For transdermal use, the penetration enhancers disclosed herein may be used in combination with the active agent or may be used separately as a pre-treatment of the skin or other body membranes through which the active agent is intended to be delivered. Dosage forms for application to the skin or other membranes of humans and animals include creams, lotions, gels, ointments, suppositories, sprays, aerosols, buccal and sublingual tablets and any one of a variety of transdermal devices for use in the continuous administration of systemically active drugs by absorption through the skin, oral mucosa or other membranes, see for example, one or more of U.S. Pat. Nos. 3,598,122; 3,598,123; 3,731,683; 3,742,951; 3,814,097; 3,921,636; 3,972,995; 3,993,072; 3,993,073; 3,996,934; 4,031,894; 4,060,084; 4,069,307; 4,201,211; 4,230,105; 4,292,299 and 4,292,303. U.S. Pat. No. 4,077,407 and the foregoing patents also disclose a variety of specific systemically active agents which may also be useful as in transdermal delivery, which disclosures are hereby incorporated herein by this reference. The penetration enhancers of this invention may also be used in admixture with other penetration enhancers disclosed earlier and incorporated herein by reference. Typical inert carriers which may be included in the foregoing dosage forms include conventional formulating materials, such as, for example, water, ethanol, 2-propanol, 1,2-propanediol, 1,3-butanediol, 2-octyldodecanol, 1,2,3,-propanetriol, oleyl alcohol, propanone, butanone, carboxylic acids such as lauric, oleic and linoleic acid, carboxylic acid esters such as isopropyl myristate, diisopropyl adipate and glyceryl oleate, acyclic and cyclic amides including N-methyl pyrrolidone, urea, freons, PEG-200, PEG-400, Polyvinyl pyrrolidone, fragrances, gel producing materials such as "Carbopol", stearyl alcohol, stearic acid, spermaceti, sorbitan monooleate, sorbital, "polysorbates", "Tweens", methyl cellulose etc., antimicrobial agent/preservative compositions including parabens, benzyl alcohol, potassium sorbate, sorbic acid, or a mixture thereof and antioxidant such as BHA or BHT. The dosage form may include a corticosteroid, such as hydrocortison, to prevent skin sensitization, a local anaesthetic, such as lidocaine or benzocaine to suppress local irritation. The examples which follow illustrate the penetration enhancers and the compositions of the present invention. However, it is understood that the examples are intended only as illustrative and are not to be construed as in any way limiting to scope of this invention. EXAMPLE 1 Preparation of 2-Ethanoylaminododecyl ethanoate To a solution of 4.1 g of 2-aminododecanol, 5 g of triethylamine in 100 ml of dichloromethane was slowly added 3.2 ml of acetyl chloride. The reaction mixture was stirred for 3 hours and then quenched by pouring into ice. The aqueous solution was extracted with dichloromethane. The organic layer was washed with water, brine and then dried, filtered and concentrated to 5.7 g of a waxy solid. Recrystallization from ether/hexane gave 4.22 g (72.2%) of the desired amidoester as white crystals, m.p. 77°-79° C. EXAMPLE 2 Preparation of 5-Amino-5-ethyl-2-carbobutoxyethyl-2-methyl-1,3-dioxane 7.46 g of 2-nitro-2-ethyl-1,3-propanediol, 8.61 g of butyl levulinate, 50 mg of p-toluenesulfonic acid in 50 ml of toluene was refluxed until no more water separated. The reaction mixture was cooled, washed with 2% sodium bicarbonate and water, dried and concentrated to give 13.65 g of 2-carbobutoxyethyl-2-methyl-5-nitro-5-ethyl-1,3-dioxane as a light yellow oil. This was dissolved in 50 ml of ethanol and hydrogenated over 1 g Raney Nickel catalyst at 60 under pressure. Distillation of the crude material at 160° C./3mm gave 11 g of the product. EXAMPLE 3 Preparation of 5-Amino-5-ethyl-2- (3 -heptyl ) -1,3-dioxane Procedure of Example 2 was repeated with 6.41 g of 2-ethylhexanal in place of butyl levulinate to give 11.6 g of the 5-nitro-1,3-dioxane, which was reduced and distilled at 135°-137° C./10 mm to give 9.23 g of the product. EXAMPLE 4 Preparation of 5-Amino-5-hydroxymethyl-2-(3-heptyl)-1,3-dioxane Procedure of Example 2 was repeated with 6.41 g of 2-ethylhexanal and 7.56 g of 2-(hydroxymethyl)-2-nitro-1,3-propanediol to give 11 g of 5-nitro-5-hydroxymethyl-1,3-dioxane derivative, which was reduced and distilled at 175°-178° C. to give 8.7 g of the product. EXAMPLE 5 Preparation of 5-Amino-5-ethyl-2-undecyl-1,3-dioxane Procedure of Example 2 was repeated with 9.216 g of dodecanal in place of butyl levulinate to give 13.4 g of the 5-nitro-1,3-dioxane derivative. Hydrogenation followed by distillation of the crude liquid at 150° C./1 mm gave 10.9 g of the product. EXAMPLE 6 Preparation of erythro-5-Amino-2,2-dimethyl-4-[(E)-pentadec-1-enyl]-1,3-dioxane 17.6 g of nitroethanol was added to a solution of 22 g of (E)-hexa-dec-2-enal in 160 ml of triethylamine under an inert atmosphere. The mixture was stirred and the reaction was followed by t.l.c. After 4 days the reaction mixture was concentrated and the residue was dissolved in dichloromethane. This was washed with ice-cold 5% HCl, water, dried and concentrated to give an orange oil. This was flash chromatographed (silica gel: hexane/ethyl acetate, 7:3) to give 21.2 g of a mixture of threo- and erythro-nitro diols. 20.9 g of the isomeric mixture, 500 ml of 2,2-dimethoxypropane and 100 mg of camphor-10-sulfonic acid was refluxed overnight under an inert atmosphere. The reaction mixture was cooled, concentrated and the residue was dissolved in dichloromethane. The organic solution was washed with bicarbonate solution, water and brine. It was dried and concentrated to give a mixture of acetonides which were dissolved in benzene and the solution was refluxed for 8 hours in presence of Merck silica gel-60. The mixture was filtered and the silica gel was washed with warm benzene. The filtrate was concentrated and the residue was chromatographed to give 16.7 g of erythro-nitro acetonide. To a suspension of 5 g of lithium aluminum hydride in 200 ml of THF was added dropwise a solution of 16.7 g of the erythro-nitro acetonide in 100 ml of THF at room temperature. The reaction mixture was stirred for 8 hours and then excess LAH was quenched with water. THF was removed under reduced pressure, the residue was diluted with ethyl acetate and the mixture was filtered. The organic layer was separated, washed with water, brine and dried. Concentration of the filtrate under reduced pressure gave 15.1 g of erythro-5-Amino-4-[(E)-pentadec-l-enyl]-1,3-dioxane as an oil. EXAMPLE 7 Preparation of erythro-5-Amino-2,2-dimethyl-4-pentadecyl-1,3-dioxane 3 g of the material obtained under Example 6 was dissolved in 50 ml of methanol and hydrogenated over 100 mg of platinum oxide catalyst. Filtration and concentration gave 2.86 g of an oil. EXAMPLE 8 Preparation of erythro and threo-5-Amino-2,2-dimethyl-4-(2,6-dimethyl-5-heptenyl)-1,3-dioxane To a mixture of 11,565 g of racemic citronellal and 13.65 g of 2-nitroethanol was added 872 mg of KF and 1.21 g of tetra-n-butylammonium bromide in 75 ml of acetonitrile and the mixture was stirred at room temperature under an inert atmosphere. After 24 hours the reaction mixture was poured into ice-cold water and extracted with ether. The ether extract was washed with water and brine, dried and concentrated to give 15.6 g of isomeric mixture of 5,9-dimethyl-2-nitro-S-decene-1,3-diol. A mixture of 14,715 g of the nitrodiol, 18.75 g of 2,2-dimethoxy-propane and 30 mg of p-toluenesulfonic acid in 150 ml of toluene was heated to reflux and water was removed by azeotropic distillation. The reaction mixture was cooled, diluted with ether and this was washed with water, brine, dried and concentrated in vacuo to give a yellow oil. The two isomers were separated by chromatography on Merck silica gel 60 and solution with benzene. 5.9 g of equatorial isomer was obtained first followed by 7.9 g of axial isomer, both as pale yellow oils. To an ice-cold mixture of 4.5 g of the equatorial nitro isomer in 210 ml of ether and 13.5 ml of water was added freshly prepared amalgamated aluminum under stirring. The temperature of the reaction mixture was allowed to come to room temperature and then it was stirred for an additional 24 hours. The reaction mixture was filtered through celite and the filter cake was thoroughly washed with ether. The filtrate was concentrated to give an oil which was passed through neutral alumina to give 3 g of erythro isomer of 5-amino-2,2-dimethyl-4-(2,6-dimethyl-5-heptenyl)-1,3-dioxane as a colorless oil. 7.5 g of the axial nitro isomer was similarly reduced to give 4.99 g of the threo isomer as a colorless oil. EXAMPLE 9 Preparation of 2-Octanoylaminododecyl octanoate To a solution of 2 g of 2-aminododecanol, 3 g of triethylamine in 50 ml of dichloromethane is added 3.5 g of octanoyl chloride. The reaction mixture is stirred overnight and then quenched by pouring into ice. This is extracted with dichloromethane and the organic solution is washed with aqueous bicarbonate solution, water and brine. The organic phase is dried over magnesium sulfate, filtered and concentrated to give 3.8 g of the product. EXAMPLE 10 Preparation of 2-Octadec-9-enoylamincdodecyl octadec-9-enoate Example 9 is repeated under identical conditions with a solution of 2 g of 2-aminododecanol, 3 g of triethylamine in 50 ml of dichloromethane to which is added 6.3 g of oleoyl chloride. The reaction mixture is worked up as under Example 8 to give 5.1 g of product. EXAMPLE 11 Preparation of 2-Ethanoylaminododecyl octadec-9-enoate To a solution of 2.43 g of 2-ethanoylaminododecanol, 3 g of triethylamine in 50 ml of dichloromethane is added 3.2 g of oleoyl chloride. The reaction mixture is worked up as under Example 9 to give 4.2 g of product. EXAMPLE 12 Preparation of 2,2-Dimethyl-5-dodecanoylamino-5-ethyl-1,3-dioxane 2,2-Dimethyl-5-amino-5-ethyl-1,3-dioxane is acylated wih dodecanoic acid in methylene chloride in the presence of DCC and 1-hydroxybenzo-triazole. Filtration and concentration gives the product. EXAMPLE 13 Preparation of 5-Dodecanoylamino-5-methyl-1,3-dioxan-2-one A solution of 2-methyl-2-nitro-1,3-propanediol and ethylene carbonate is heated overnight. The reaction mixture is diluted with ethyl acetate and the solution is washed with water. The organic phase is dried and concentrated to obtain 5-methyl-5-nitro-1,3-dioxan-2-one. This is dissolved in methanol and hydrogenated under pressure to give the 5amino compound which is acylated with dodecanoyl chloride to give the product. EXAMPLE 14 Preparation of 5-Amino-5-undecyl-1,3-dioxan-2-one 2-Nitro-2-undecyl-1,3-propanediol is treated under identical conditions according to the reaction sequence outlined under Example 13 to give the product. EXAMPLE 15 The following analgesic gel is prepared: ______________________________________ %______________________________________Carbopol 941 1.5Diclofenac Na 12-Propanal 35Diisopropanolamine 1.8Diisopropyl adipate 55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 2Water 53.7______________________________________ EXAMPLE 16 The following cream formulation is prepared: ______________________________________ %______________________________________Isosorbide dinitrate 1.0Glycerol monostearate 5.5Polyoxyethylene stearate 4.5C8-C18 fatty acid esters of a 8glycerol ethoxylated with about7 moles of ethylene oxide5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 2Sorbic acid 0.165Ascorbyl palmitate 0.055Citric acid 0.1Na EDTA 0.014Fragrance 0.05Water 78.616______________________________________ This formulation is effective in the treatment of angina. EXAMPLE 17 The following skin moisturizing formulation is prepared: ______________________________________ %______________________________________Pyrrolidonecarboxylic acid Na 1Glycerine 4Citric acid 0.03Sodium citrate 0.05Allantoin 0.1Ethanol, 95% 9Oleth-15 1Linaleic acid 15-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 2Sunscreen agent 0.1Water 81.72______________________________________ EXAMPLE 18 The following formulation for promoting hair growth is described. ______________________________________ %______________________________________Minoxidil 2.0Benzyl nicotinate 0.5Ethanol 40.01,2-Propanediol 20.05-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 5.0Ethyl aleate 5.0Water 27.5______________________________________ EXAMPLE 19 The following solution formulation is prepared. ______________________________________ %______________________________________Griseofulvin 15-Amino-5-ethyl-2-(3-heptyl)1,3-dioxane 1.5C12-C15 benzoate 5Fragrance 0.1Ethanol 92.4______________________________________ This formulation is effective in the treatment of fungus infection. EXAMPLE 20 The following depilatory gel is prepared. ______________________________________ %______________________________________Poloxamer 407 15.0Benzyl alcohol 6.0Urea 6.5alpha-Thioglycerol 6.55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 5.0Water q.s. 100.0Sodium hydroxide g.s. to pH 12.5______________________________________ EXAMPLE 21 The following cream formulation is prepared: ______________________________________ %______________________________________Clindamycin Base 1.0Stearyl alcohol, U.S.P. 12.0Ethoxylated cholesterol 0.4Synthetic spermaceti 7.5Sorbitan monooleate 1.0Polysorbate 80, U.S.P. 3.05-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 1.9Sorbitol solution, U.S.P. 5.5Sodium citrate 0.5Chemoderm #844 0.2Purified water 67.0______________________________________ This formulation is effective in the treatment of ache. EXAMPLE 22 The following solution formulations are prepared: ______________________________________ A (%) B (%)______________________________________Clindamycin base -- 1.0Clindamycin phosphate acid 1.3 --Sodium hydroxide 0.077 --1M Hydrochloric acid -- 2.27Disodium edentate.2H20 0.003 0.003Fragrances 0.5 0.55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 1.0 1.0Purified water 20.0 17.73Isopropanal 77.12 77.497______________________________________ These solutions are effective for the treatment of ache in humans. EXAMPLE 23 The following solution formulation is prepared: ______________________________________ %______________________________________Neomycin sulfate 0.5Lidocaine 0.5Hydrocortisone 0.255-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 1.50Propylene glycol 97.25______________________________________ This solution is effective for the treatment of otitis in domestic animals. EXAMPLE 24 The following sunscreen emulsion is prepared: ______________________________________ %______________________________________PABA 2.0Benzyl alcohol 0.55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 2.0Polyethylene glycol 9.0Isopropyl lanolate 3.0Lantrol 1.0Acetylated lanolin 0.5C12-C15 benzoate 5.0Diisopropyl adipate 2.0Cetyl alcohol 1.0Veegum 1.0Propylene glycol 3.0Purified water 70.0______________________________________ EXAMPLE 25 The following antineoplastic solution is prepared: ______________________________________ %______________________________________5-Fluorouracil 55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 1.5Polyethylene glycol 5Purified water 88.5______________________________________ EXAMPLE 26 The following insect repellant atomizing spray is prepared: ______________________________________ %______________________________________N,N-diethyltoluamide 0.55-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 0.5Ethanol 99______________________________________ EXAMPLE 27 The following cream formulation may be prepared containing about 0,001 to 1 percent, with preferably 0.1% fluocinolone acetonide: ______________________________________ %______________________________________Oil PhaseFluocinolone acetonide 0.15-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane 1.6Cetyl alcohol 9.3Stearyl alcohol 1.3Glyceryl monostearate 3.8Water PhasePropylene glycol 10Sodium dodecyl sulfate 0.1Deionized water q.s. 100______________________________________ The steroid is dissolved in the vehicle and added to a stirred, cooling melt of the other ingredients. The preparation is particularly useful for the treatment of inflamed dermatoses by topical application to the affected skin area. The amount and frequency of application is in accordance with standard practice for topical application of this steroid. Penetration of this steroid in the inflamed tissue is enhanced and a therapeutic level is achieved more rapidly and sustained for longer duration than when the steroid is applied in the conventional formulation. EXAMPLE 28 Transdermal patches containing nicotine with the following composition are prepared. 800 mg of Estane (B.F. Goodrich) is dissolved in 10 ml THF and 99 mg of nicotine, 50 mg of 1,2-propanediol and 50 mg of 5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane is added. The homogenous solution is poured in a petri dish and the solvent is removed. The patches are die cut from the polymer film. EXAMPLE 29 Transdermal patches containing progesterone with the following composition are prepared. 9.2 g of PDMS-382 (Dow Corning) pre-polymer, 300 mg of progesterone and 500 mg of 5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane are mixed. One drop of polymerization initiator is added and the contents are thoroughly mixed. The mixture is degassed and allowed to polymerize in sheet molds for 24 hours at room temperature. After the curing is complete disks with 1 cm diameter are die cut. EXAMPLE 30 Transdermal patches containing estradiol with the following compositions are prepared. 8.5 g of PDMS-382 (Dow Coming) pre-polymer, 1 g of estradiol, 500 mg of 5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane are mixed and the patches are prepared as under Example 29. EXAMPLE 31 EXAMPLES 15-30 are repeated, except the 5-Amino-5-ethyl-2-(3-heptyl)-1,3-dioxane is replaced with an equimolar amount of each of the following listed compounds, and comparable results are obtained. 2-Ethanoylaminododecyl ethanoate 2-Ethanoylaminododecyl octadec-9-enoate 5-Amino-2,2-dimethyl-4-(pentadec-l-enyl)-1,3-dioxane 5-Amino-2,2-dimethyl-4-pentadecyl-1,3-dioxane 5-amino-4-dodecyl-1,3-dioxan-2-one 4-Dodecyl-5-ethanoylamino-1,3-dioxan-2-one 2-Ethanoylamino-3-octadecyloxypropyl ethanoate 5-Amino-2,2-dimethyl-4-(2,6-dimethyl-5-heptenyl)l,3-dioxane 5-Amino-5-ethyl-2-undecyl-1,3-dioxane 2,2-Dimethyl-5-dodecanoylamino-5-ethyl-1,3-dioxane 5-Amino-5-hydroxymethyl-2-(3-heptyl)-1,3-dioxane 5-Amino-5-ethyl-2-carbobutoxyethyl-2-methyl-1,3-dioxane EXAMPLE 32 The compounds of the present invention are tested in vitro as penetration enhancers according to the procedure outlined below. Human stratum corneum is isolated from full thickness human skin as described by Bronaugh et al., J. Pharm. Sci. 75, 1094 (1986). The skin is placed between the donor and the receptor compartments of diffusion cells in such a way that the dermal side of the skin faces the receptor compartment which is filled with normal saline (pH 7.2-7.4). The stratum comeurn is equilibriated at 37° C. overnight prior to the application of a topical formulation or transdermal patch. All formulations are studied in triplicate. About 500 mg of the following three Isosorbide Dinitrate (ISDN) formulations (40% ISDN & 60% Lactose) are applied to cover the stratum comeurn surface within the donor compartment. The entire contents of the receptor compartment are removed at specific time intervals over 51 hours and replenished with fresh saline. The aliquots are analyzed by HPLC and the average cumulative amount of ISDN in micrograms permeating over the study period is calculated. The results show that the formulations containing the penetration enhancers of the present invention show superior permeation as compared to control. While particular embodiments of the invention have been described it will be understood of course that the invention is not limited thereto since many obvious modifications can be made and it is intended to include within this invention any such modifications as will fall within the scope of appended claims.

A method and compositions for enhancing absorption of topically administered physiologically active agents through the skin and mucous membranes of humans and animals in a transdermal device or formulation for local or systemic use, comprising a therapeutically effective amount of a pharmaceutically active agent and a non-toxic, effective amount of penetration enhancing agent of the formula I or a physiologically acceptable salt thereof: ##STR1## wherein: R 1 , R 2 , R 3 and R 4 are as defined herein.

BACKGROUND OF THE INVENTION In a selctive call communication system a particular receiver is rendered operative when the carrier wave signal applied thereto contains a certain tone or set of tones to which the decoder in such receiver is designed to respond. These tones are generated by an encoder, which tones are then modulated onto the carrier wave generated by the transmitter with which that encoder is associated. In systems involving voice communication, the tone or set of tones is transmitted to unsquelch the receiver, whereupon the operator at the transmitter can speak into his microphone and the possessor of the associated receiver will hear his words. Alternatively, the system may involve nonvoice communication, wherein the receiver emits an alerting signal such as a tone when the proper tone or set of tones is applied thereto. Usually in such systems, there is a single base station which has a transmitter, an associated encoder, and other interface equipment to enable persons to gain access to the transmitter. Such equipment may take the form of a telephone system in which a person dials a certain number to connect the telephone to the transmitter, whereupon a selected code may be transmitted. Usually a multiplicity of receivers will be associated with such transmitter. For example, a system used in a hospital would entail each doctor being furnished with a receiver designed to emit an alerting signal in response to a unique code. In this type of system, the transmitter is likely to be very expensive compared to the cost of the individual receivers. Since there is only one transmitter, the cost thereof does not render the cost of the entire system prohibitive. It has been proposed to use selective call capability in an automatic identification system. In such system, each user, such as a vehicle, is furnished with a transmitter and an associated encoder to enable the user, not only to receive a voice message, but also to communicate with the base station and also to identify himself without so stating. When the vehicle driver wishes to communicate with the base station, he operates his push-to-talk switch and speaks into his microphone. With automatic identification capabilities, the encoder generates a signal representing that encoder, which signal is modulated onto the carrier wave. The identification signal, by way of a suitable display or otherwise, apprises the base station operator of the identity of the encoder transmitting. The value of such automatic identification is recognized and need not be delved into here. In prior systems, the information automatically sent to the base station has been limited to the identity of vehicle or driver. Such systems have not supplied additional information, such as where the vehicle is located or what is its status, etc. Furthermore, the encoders previously available have not been sufficiently inexpensive to enable widespread use such as is necessary when many vehicles are provided with an encoder. It is important in selective call communication systems to maximize the number of channels used in a given frequency spectrum. In other words, if the frequency spectrum for tones is, for example 500 Hz. to 3,500 Hz., it is desirable to maximize the number of channels within that range that can be utilized. Of course, the limiting factor is that the channels cannot be so close that operation of a decoder responsive to one channel will also operate a decoder responsive to an adjacent channel. Furthermore, with limiting, the encoders generate not only the specific tone, but also its harmonics, particularly its third harmonic. It is therefore important that the third harmonic of one tone in the frequency spectrum not coincide with other channels in the spectrum and, in fact, be as far removed as possible therefrom. Since each vehicle in such a system is also provided with a receiver and an associated decoder to respond to a particular sequence of tones, it is equally desirable that the cost of the decoder be minimized. SUMMARY OF THE INVENTION It is therefore an important object of the present invention to provide in a selective call communication system encoders and decoders which are less expensive to make. Another object is to provide an automatic identification system which not only supplies the base station with the identity of the encoder transmitting, but also other selected information, such as its status. Still another object is to maximize the frequency difference between tones used in a selective call communication system and third harmonics of such tones. In one aspect of the present invention, there is provided an encoder for a selective call transmitter comprising oscillator means for producing a sequence of first tones, multiplier means coupled to the oscillator means for multiplying the frequencies of the first tones by a predetermined multiplier to produce a sequence of second tones, an output circuit coupled to the oscillator means and to the multiplier means for receiving the sequence of the first tones and the sequence of the second tones, and control means coupled to the output circuit for rendering the output circuit operative to alternate between supplying the first tones and the second tones. In another aspect of the invention, the encoder also comprises switchable impedance means associated with the oscillator means for controlling the frequency of the tone produced thereby, counter means coupled to the switchable impedance means for sequentially changing the value of impedance furnished thereby to cause the oscillator means to produce a sequence of tones, clock means for producing clock pulses at a predetermined rate, and switching means having a pair of inputs respectively coupled to the oscillator means and to the clock means for producing a sequence of pulses at the predetermined rate each having a leading edge in time coincidence with an instant when the amplitude of the tone produced by the oscillator means is substantially zero, whereby each tone in the sequence of tones has a duration substantially proportional to the predetermined rate and is substantially in phase with the preceding tone in the sequence of tones. In yet another aspect of the invention, the oscillator means generates tones selected from a first group of tones in a first band of frequencies and tones selected from a second group of tones in a second band of frequencies separate and distinct from the first band of frequencies, the tones in the second bank respectively being harmonics of the tones in the first bank, and means for receiving the tones from the oscillator means and for producing a sequence of tones alternately from the first and second groups. In a further aspect of the invention, the sequence of tones produced by the oscillator means includes at least one identification tone representing the identification of the encoder and at least one information tone representing information relative to the encoder, program means for internally fixing the frequencies and the order of the identification tones, and selector means for externally selecting the frequencies of the information tones, whereby energization of the encoder automatically produces identification tones corresponding to the program of the program means and information tones corresponding to the condition of the selector means. In a still further aspect, there is provided a single switch for operating the encoder and the decoder, and lockout circuitry to insure that when the decoder is in use, the associated encoder is not accidentally operated. The invention consists of certain novel features and a combination of elements hereafter fully described, illustrated in the appended claims, it being understood that various changes in the details of the circuitry may be made without departing from the spirit or sacrificing any of the advantages of the invention. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings preferred embodiments thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages can be readily understood and appreciated. FIG. 1 is a diagram partially in block and partially in schematic depicting a selective call communication transmitter having an encoder incorporating the features of the present invention; FIG. 1A is a block diagram of the multiplier circuit and the phase-synchronized circuit of FIG. 1; FIG. 2 is a timing diagram showing wave forms at various points in FIG. 1; FIG. 3 is a diagram partially in block and partially in schematic depicting a receiver having a decoder incorporating therein other features of the present invention; and FIG. 4 is a timing diagram showing wave forms at various points in the diagram of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning first to FIG. 1, there is depicted therein a transmitter 20 adapted to generate an RF carrier wave modulated selectively by audio signals and by tones. The transmitter 20 includes an oscillator 22 which develops on its output a relatively low-frequency oscillatory signal. A modulator 24 receives the oscillatory signal from the oscillator and also receives audio signals supplied by an audio amplifier 26. The audio signals are either tones generated by an encoder to be described presently or electrical signals representative of a voice message applied to a microphone 28 and then amplified in a preamplifier 30. The audio signals from the amplifier 26 are modulated by the modulator 24 onto the oscillatory signal. The frequency of the modulated signal is increased in a frequency multiplier 32 and then its amplitude increased in a power output amplifier 34, thereby to provide a high level, frequency multiplied carrier wave which is emitted from an antenna 36. Although the transmitter 20 is of the FM type, that is merely exemplary. The transmitter 20 also includes a power supply 38 which provides a supply voltage to the other elements in the transmitter, including the power output amplifier 34, the audio amplifier 26, etc. The power supply 38 is selectively rendered operative by a relay 40 having a winding 42 and contacts 44. In a manner to be described presently, when the winding 42 is energized, the contacts 44 close to enable the power supply 38 to supply power to the rest of the transmitter 20. The transmitter 20 also includes an encoder 50 which provides the tones to the audio amplifier 26. The encoder 50 includes a switch 52 having a set of normally open contacts 54 and a set of normally closed contacts 56 (FIG. 3). A single actuator (not shown) is adapted simultaneously to close the contacts 54 and to open the contacts 56. A capacitor 60 is charged rapidly through a resistor 58 when the contacts 54 are closed, and discharged relatively slowly through a resistor 61. There is provided a latching circuit 62 which is in the form of a bistable multivibrator and is composed of two NOR gates 64 and 66 connected as shown. When the switch 52 is actuated, the contacts 54 close and, as shown in FIG. 2A, the capacitor 60 charges rapidly, in about 2 ms., to a level 1, at which the latching circuit 62 switches, and the output thereof becomes "high," as can be seen in FIG. 2B. As is standard in logic nomenclature, this application will refer to "high" and "low" inputs and outputs. The term "low" means that the voltage is at its low value, for example, zero, and the term "high" means that it is at its high value, for example, close to the supply voltage. The output of the latching circuit 62 is connected by way of a resistor 68 to an NPN transistor 70, the emitter of which is grounded and the collector of which is coupled through the relay winding 42 to the B+ supply voltage. Thus, when the latching circuit 62 is energized, and the output thereof becomes high, the transistor 70 is rendered conductive to energize the relay 40, closing the contacts 44 and thereby supplying power to the transmitter 20, enabling it to produce a carrier wave prior to transmitting the tones. The output of the NOR gate 66 is coupled through a resistor 92 to one input of a NOR gate 94, the other input of which is derived from the contacts 54. The output of the NOR gate 94 is coupled by way of a resistor 96 to an NPN transistor 98, having its emitter grounded and its collector coupled to a bulb 414 (FIG. 3). The output of the NOR gate 94 is also coupled to a further NOR gate 100 connected to be an inverter. The output of the NOR gate 100 is coupled to an astable multivibrator 102 comprised of two NOR gates 104 and 106, resistors 108 and 110, and a capacitor 112. When energized, the multivibrator 102, as shown in FIG. 2D, produces a sequence of pulses having a predetermined repetition rate determined by the values of the resistors 108 and 110 and the capacitor 112. The resistor 110 is variable to enable selection of such rate, which controls the duration of each tone in the sequence produced by the encoder 50. When the contacts 54 are closed, the capacitor 60 charges rapidly, as previously mentioned. When the switch 52 is released, the contacts 54 open and the capacitor 60 discharges through the resistor 61, causing the NOR gate 94 to switch when the voltage reaches the level 1 2 (FIG. 2A). The output of the NOR gate 94 thereupon becomes high (FIG. 2C), to render conductive the transistor 98 and to cause illumination of the bulb 414 (FIG. 3). The high output from the NOR gate 94 is inverted by the NOR gate 100 to provide a low input to the NOR gate 104, thereby rendering the multivibrator 102 operative to produce the sequence of pulses. One input to the NOR gate 94 remains low until the next time the switch 52 is actuated, while the other input remains low until the latching circuit 62 is opened, in the manner to be described hereinafter. The output of the NOR gate 100 is also coupled by way of a resistor 114 to the base of a PNP transistor 116 having its emitter coupled to the supply voltage and its collector coupled to the preamplifier 30. When the output of the NOR gate 100 becomes low, the transistor 116 is rendered conductive, which applies a disabling voltage to the preamplifier 30. Thus, while the tones are being generated, no speech applied to the microphone 28 will be transmitted. The output of the latching circuit 62 is inverted by an inverter 118, the output of which is coupled to an oscillator 120. An NPN transistor 122, biasing resistors 124, 126, and 128, frequency determining capacitors 130 and 131, and an inductor 132 comprise the oscillator 120. The oscillator 120 begins to produce a signal (FIG. 2E) at the same time the output of the NOR gate 64 becomes high. The inductor 132 has ten taps 132a to 132j. A terminal block 134 has a plurality of electrical sockets 134a through 134j respectively coupled to the taps 132a to 132j. Also, the block has a set of sockets 136a to 136d respectively coupled to the collectors of four switching transistors 138a to 138d, the emitter of each of which switching transistors is coupled to the B+ supply voltage. Associated with the block 134 is a plug 140, having pins 140a to 140j and 142a to 142d. The plug 140 is adapted to be programmed to set the code produced by the encoder 50 by connecting jumper wires from selected ones of the pins 140a to 140j to the pins 142a to 142d. The particular encoder shown is capable of producing a sequence of as many as four tones which can be internally programmed by connecting all four pins 142a to 142d to selected pins 140a-140 j. As an example only pins 140b and 140e, are respectively connected by way of jumper wires to the pins 142a and 142b, so as internally to program two tones. The particular embodiment described envisions a sequence of two internally programmed tones followed by a third externally selected tone, as will be explained. Initially the transistor 138a is conducting, whereas the transistors 138b to 138d are initially nonconducting, which will be described in greater detail hereinafter. Then, the supply voltage on the emitter of the transistor 138a is coupled through its collector, through the terminal 136a, the pin 142a, the corresponding jumper 144, the pin 140b, the socket 134b, whereby that portion of the inductor 132 between a tap 132b and an end 132k will be in circuit with the oscillator 120. The oscillator 120 will therefore produce a tone when energized, in accordance with the value of such inductance and the value of the capacitor 130. As previously explained, the output (FIG. 2B) of the NOR gate 64 becomes high when the switch 52 is closed, which output is inverted by the inverter 118 to provide a low input to the oscillator 120 for energization thereof. The output from the oscillator 120 is derived from the emitter of the transistor 122, the oscillatory signal produced thereby being amplified and inverted by the amplifier 150 to produce a square wave (FIG. 2F) of a frequency corresponding to the frequency of the oscillatory signal from the oscillator 120. Such square wave is applied to the clock input C of a multiplier circuit 152. The multiplier circuit 152 consists of a "dual `D` type flip-flop" device with set and reset capability, having set (S), reset (R), clock (C), data (D), and supply (V) inputs and "Q" and "Q" outputs. Each such device is schematically illustrated in FIG. 1A. As an example, Solid State Scientific, Inc. makes a product under the designation LCL4013A which contains two such flip-flops on a single monolithic silicon chip. The D and Q inputs are connected together, and the R, V, and S are grounded. With such connections, the signal on the Q output has one half the frequency of the signal on the C input, whereby the predetermined multiplier of the multiplier circuit 152 is one half. Therefore, there will appear on the Q output a square wave, as shown in FIG. 2M, at one half the frequency of the oscillatory signal (FIG. 2E) from the oscillator 120. The second input to the NAND gate 154 is derived across a resistor 156 through a diode 158. The signal applied to such diode, as shown in FIG. 2J, becomes high during the second tone, and is low before and after the second tone. The origin of such signal will be described hereinafter. Accordingly, as can be seen in FIG. 2N, the output of the NAND gate 154 is high during the first tone, and follows the Q output (FIG. 2M) during the second tone, but is inverted. The signal represented by the waveform of FIG. 2J is also coupled to a NAND gate 160 connected as an inverter, whereby the output (FIG. 2P) thereof is low during the second tone, but is high the rest of the time. The output of the NAND gate 160 is connected to one input of a further NAND gate 162, the other input of which is coupled to the output of the amplifier 150. The low input to the NAND gate 162 during the second tone causes the output of the NAND gate 162 to be high for that interval, but, during the rest of the time, there appears on such output an inverted form of the square wave from the amplifier 150. The output of the NAND gates 154 and 162 are respectively coupled as inputs to a NOR gate 164. During the first and third tones, the signal from the NAND gate 162 (FIG. 2Q) is inverted and coupled to the output of the NOR gate 164, while during the second tone the output of the NAND gate 154 (FIG. 2N) is coupled to such output, whereby the output of the OR gate 164, shown in FIG. 2R, includes a first tone having a frequency equal to the frequency of the tone produced by the oscillator 120 during the interval t 2 -t 3 , a second tone having a frequency equal to one half the frequency of the tone produced by the oscillator 120 during the interval t 3 -t 4 , and a third tone having a frequency equal to the frequency of the tone produced by the oscillator 120 during the interval t 4 -t 5 . The output of the NOR gate 164 is coupled to a further NOR gate 166 having a second input on which appears a signal represented by the waveform of FIG. 2H. Such input is high prior to time t 2 when the tones commence, whereby the output of the NOR gate 166, as shown in FIG. 2S, is low during the interval t 1 -t 2 . Starting at t 2 , the output of the NOR gate 166 is the inverse of the output from the NOR gate 164 (FIG. 2R). The output of the NOR gate 166 is coupled by way of a resistor 168 to an emitter follower transistor 170, the collector of which is coupled to the supply voltage, and the emitter of which is coupled through a potentiometer 172 to ground. The movable arm of the potentiometer 172 is coupled by way of a capacitor 174 to the audio amplifier 26. The signal coupled to the amplifier 26 consists of a sequence of three square wave tones, shown in FIG. 2T. The transistors 138a to 138d are sequentially rendered conductive by, and certain of the inputs to the gates 154, 160, and 166 are derived from, a counter 176. The counter 176 has a plurality of outputs and a clock input. A pulse train applied to the clock input will cause each output to become high in succession. An example of a counter that may be used, is one sold by Solid State Scientific, Inc. under the designation SCL4017A, which it calls a "CMOS decade counter/divider." Such device has clock (C), reset (R), clock enable (CE) inputs, and ten outputs "0" to "9". In this particular form, only the outputs "0" to "4" are used, and therefore outputs "5" to "9" are not shown. The CE input is grounded, the R input is coupled to the NAND gate 118, and the C input is coupled to a clock 190 which furnishes a sequence of pulses shown in FIG. 2G. With such connections, the "0" output is high and the other outputs "1" to "4" are low in the quiescent condition of the counter 176. The first positive going transition at the C input causes the "0" output to become low, the "1" output to become high, and the "2" to "4" outputs to remain low. The next positive transition at the C input causes the "2" output to become high and the rest of the outputs to be low, etc. In order for the stepping operation just described to take place, the R input must be low. The "0" and "1" outputs are coupled respectively through diodes 180 and 182 to appear across a resistor 184 as inputs to an NPN transistor 186a, the collector of which transistor is coupled to the base of the transistor 138a. The transistors 186a and 138a define an electronic switch. The "2", "3" and "4" outputs are respectively coupled to NPN transistors 186b, 186c and 186d, the collectors of which transistors are respectively connected to the bases of the transistors 138b to 138d. Associated pairs of the transistors (e.g. 186b and 138b) define electronic switches. Initially, the "0" output of the counter 176 is high (FIG. 2H), thereby actuating the switch consisting of the transistors 138a and 186a, to cause the associated portion of the inductor 132 to be coupled in circuit in the oscillator 120, as previously described. As can be seen in FIG. 2G, the first positive transition of the C input to the counter 176 occurs at time t 2 , causing the counter 176 to step so that the "1" output becomes high (FIG. 2I). The transistors 186a and 138a are maintained conductive so that the oscillator 120 continues to run at the same frequency. The next clock pulse, that is, a positive transition, occurs at time t 3 , which causes the "2" output to become high (see FIG. 2J). The transistors 186b and 138b conduct, thereby coupling in the oscillator 120 another portion of the inductor 132. Similarly, when the "3" output of the counter 176 becomes high (FIG. 2K), in response to a clock pulse at t 4 , yet another portion of the inductor 132 is connected in circuit with the oscillator 120 to change the frequency of oscillation thereof. In order to insure that there are no discontinuities as the oscillator 120 changes its frequency of oscillation, there is provided a phase synchronized clock 190 to supply the pulses to the "C" input of the counter 176, such clock is the second flip-flop device on the silicon chip, previously discussed (the first such flip-flop device is the multiplier circuit 152). The flip-flop device constituting the phase synchronized clock 190 also has data (D), set (S), reset (R), and clock (C) inputs and Q and Q outputs. The S and R inputs are connected to ground, the D input is connected to the output of the NOR gate 106, and the clock input C is connected to the inverting amplifier 150. Considering the logic of the clock 190, its Q output will become high if its D input is low and its C input has a rapidly rising transition; the Q output will become low if the D input is high and the C input receives a rapidly rising transition; and the Q output will not change if the C input is receiving a rapidly falling transition, irrespective of the D input. Referring to FIG. 2D, the D input first becomes low shortly before t 2 . Referring to FIG. 2F, the C input receives a rapidly rising transition at t 2 , at which time, therefore, the Q output rises, as may be seen in FIG. 2G. The Q output remains high until the concurrence of a high D input and a rising transition at the C input. Thus, midway between time t 2 and t 3 , the Q output becomes low. At time t 4 , the D input is already low and the C input receives a rising transition, whereby the Q input becomes high. Following through on this analysis the clock signal appearing on the Q output is that shown in FIG. 2G. It should be noted that the leading edge of each positive pulse in the wave form of FIG. 2G is in time coincidence with a leading edge of a pulse in the pulse train at the output of the amplifier 150 (FIG. 2F), which in turn corresponds to the instant when the signal out of the oscillator 120 is substantially zero (FIG. 2E). It is the leading edge of each of the positive pulses on the Q output which, when applied to the clock input C of the counter 176, causes the counter 176 to step to the next output, as may be seen by FIGS. 2G-2L and the dashed vertical lines therebetween. It is at these times, when the frequency of oscillation of the oscillator 120 shifts and because it is shifting at a time when the amplitude of the oscillatory signal produced thereby is substantially zero, there will be no discontinuity between the two tones as the change takes place. In other words, there will be a minimal loss of energy by the oscillator 120 during the transition, because the phase between two tones in sequence is substantially continuous. This also results in a faster tone signaling. While the first two tones in the sequence are internally programmed by the jumpers 144 and the plug 140, the third tone is externally programmed by a switching apparatus 200 having three double-throw switches 202, 204, and 206 connected in the manner shown. Each of the switches has a first position shown and a second position when each slide contact is moved to continue to engage the center fixed contact, and to engage the lower fixed contact rather than the upper fixed contact. If the switch 202 is actuated, there will be coupled to the collector of the transistor 138c the tap 132g. In that case, the oscillator 120 will produce during the last interval t 4 -t 5 an oscillatory signal corresponding to the value of the inductance between the taps 132g and 132j. If, instead, the switch 204 is actuated, then the oscillatory signal will be representative of the inductance between the taps 132h and 132j, while, if the switch 206 is, instead, actuated, the oscillatory signal will have a frequency dependent upon the value of the inductance between the taps 132 i and 132j. When any one of the three switches 202 to 206 is actuated, there will appear a short across the conductors 208 which, in turn, renders the speaker (FIG. 3) operative to hear whether the channel corresponding to the decoder is being used. If he hears communication, then he knows that the channel is being used and he must wait. As soon as the channel is quiet, he can operate the switch 52 to transmit the sequence of three tones, the first two of which were internally programmed by the connector 140 and represent the identification of the encoder 50, while the third tone in the sequence has been manually selected by the operator of the encoder, by actuating one of the switches 202 to 206. Actuation of the switch 202 might mean, for example, that the vehicle in which the encoder 50 is mounted is available for assignment, while actuating the switch 204 might mean that he has just completed assignment and is going home, etc. Upon completion of the three tones, the "4" output of the counter 176 becomes high (FIG. 2L), which output is coupled through a diode 212 as one input to a NOR gate 214, the output of which NOR gate is inverted by an inverter 216, and then coupled as a second input to the NOR gate 64. The high input to the NOR gate 214 supplies a low input to the NOR gate 64, thereby opening the latch at time t 5 , that is, the output of the NOR gate 64 becomes low. Such low output de-energizes the transistor 70, so that the supply voltage from the power supply 38 to the transmitter 20 is disrupted. Also, the low output from the NOR gate 64 is inverted by the inverter 118 to cause the R input of the counter 176 to become high, thereby resetting the counter. When reset, its "0" output becomes high and the other outputs "1" - "4" are low. The high output from the inverter 118 de-energizes the oscillator 120, causing the oscillatory signal (FIG. 2E) to end. The output of the NOR gate 66 becomes high, thereby providing a high input to the NOR gate 94, causing the output of the NOR gate 94 to become low, thereby extinguishing the bulb 414, so as to apprise the operator that the tone transmission has been completed. Also, operation of the multivibrator 102 is disrupted and the preamplifier 30 enabled. A high input to the NOR gate 214, to accomplish the termination and reset just described, is also furnished by the switch apparatus 200. If none of the switches 202, 204 and 206 is actuated, then, during the third tone when the transistor 138c becomes conductive, the supply voltage will be coupled therethrough, through the switches 202, 204 and 206, to provide the high input to the NOR gate 214. It should be understood that the encoder 50 is more inexpensively constructed because of the use of a single oscillator to provide twenty different tones. Ten tones are provided by virtue of the ten taps on the inductor 132, and ten more tones are provided by halving the signals produced by that oscillator. The absence of the additional oscillator and associated circuitry also reduces the weight and size of the encoder. The encoder 50 has capability of being internally programmed to establish the tones for automatic identification. Also, externally selected tones supply information on the status of the encoder. Although only five outputs of the counter 176 are shown, the particular counter used in the example has ten such outputs, so that it has the capability of supplying several more tones in sequence if desired. Also, the number of tones being internally programmed and the number of tones subject to external selection can be varied in accordance with particular needs. There can be provided various socket and plug arrangement, such as has been shown to select the frequencies of oscillation of the oscillator 120, and to select the number of tones. One such socket-plug arrangement could be used which couples all those outputs of the counter that are needed to interconnect the switching transistors 138a-138d to the associated coil taps. Alternately, a socket-plug arrangement may be employed to select all tones in the sequence by the switching apparatus 200. For example, all ten tones could be available for external selection, rather than just the three corresponding to the taps 132j to 132i. The selection of the tones in the encoder 50 is significant. First, it is clear that the every other tone in the transmitted sequence is selected from one bank of frequencies, while the remaining tones are selected from a second bank. The ten tones in the first bank are respectively harmonics of the ten tones in the second bank; in this example, each tone in the first bank is a second harmonic of a corresponding tone in the second bank. However, other harmonic relationships are certainly contemplated. One difficulty in making the proper selection of available tones is to insure that harmonics of the tones in one bank are not the same as tones in the other bank. This consideration is particularly important in an encoder as above described, since it squares the oscillatory signal. A square wave has virtually no second harmonics of the original sine wave, but is rich in third harmonics. In fact, it is desirable that the third harmonics actually be displaced by as much as possible from the tones in the other bank. It has been found that such optimum placement occurs when each tone is the 11th root of 2 times the next lower tone. The tones in the other bank have a similar relationship, but are obtained by halving the frequencies of the tones in the first bank. The tones in the two banks using such a relationship may be as follows: ______________________________________First Bank Second Bank______________________________________# Freq. # Freq.0 2400 OA 12001 2253.43 1A 1126.722 2115.82 2A 1057.913 1986.61 3A 993.34 1865.29 4A 932.645 1751.38 5A 875.696 1644.42 6A 822.217 1544 7A 7728 1449.71 8A 724.859 1361.18 9A 680.59______________________________________ With such tones, the third harmonic of any tones of one bank that happen to fall within the frequency spectrum of the second bank fall substantially midway between the channels. The feature of operating the switch 52 to start the transmitter 20 and then releasing that switch to start the sequence of tones insures that the carrier wave will be produced before the tones commence, so that no part of the tone sequence is lost. Alternatively, there could be employed a delay after the encoder is operated to allow the carrier wave to be produced, after which delay a quick start oscillator produces the tones. It is contemplated that the encoder 50 will be used to transmit to a base station having a display or other means of enabling the base station operator to evaluate the codes received. For example, a board may display a three-digit number in which the first two digits represent the identification of the encoder transmitting, and the last digit represents his status. If the number "123" appeared on the board, the base station operator would know that vehicle 12 is communicating with him and his status is 3 which may mean that that vehicle is ready for assignment. It is also contemplated that the decoder in such base station would have the frequency division structure described above. It becomes even more important in the decoder because the decoder in the base station would have to have capabilities to respond to a large number of different codes corresponding to the number of encoders in the field. FIG. 3 depicts a receiver 250 in which RF signals are applied to an antenna 252, then amplified by an RF amplifier 254, which is heterodyned in a mixer 256, using a local oscillator 258. The resulting IF signal is amplified in an amplifier 260 and then further amplified to limiting by a limiter 262. A discriminator 264 detects the modulation components in the signal, which modulation components include a sequence of tones followed by electrical signals representative of intelligence. The demodulated signal is coupled by way of a transformer 266 to a speaker 268, wherein the signal is converted into sound waves. In order for such conversion to take place, the contacts 270, which are normally open, must be closed. These contacts are part of a relay having a winding 272. When the winding 272 is energized, in the manner to be described hereinafter, the contacts 270 close, and the speaker 268 can reproduce the electrical signals applied thereto. The demodulated signals on the secondary of the transformer 266 are applied to a decoder 280 which includes a transformer 282. The demodulated signals on the secondary of the transformer 282 are depicted in FIG. 4A, and include noise and other extraneous components during the interval t o -t 1 , a first tone during the interval t 1 -t 5 , a second tone during the interval t 5 -t 8 , followed by a voice message during the interval t 8 -t 9 . The gaps in FIG. 4A indicate that many cycles of the signals may appear during each interval. For example, each of the two tones may have a duration of 100-150 ms. The demodulated signals are limited by the back-to-back diodes 284 and 286, and are impedance matched and filtered by the resistors 288-294 and the capacitor 296. The demodulated signals are amplified in an amplifier 298, to convert them into a square wave of the same frequencies, as shown in FIG. 4B. The square wave is applied to a Schmitt trigger circuit 300 which, in turn, supplies a square wave for the clock input C of a multiplier circuit 320. An example of such multiplier circuit is the flip-flop device illustrated in FIG. 1A, and used as the multiplier circuit 152. The R, S, and V inputs of the multiplier circuit 320 are grounded, while the D input and the Q output are connected together. The multiplier circuit 320 performs in the same manner as the multiplier circuit 152 of FIG. 1, that is, the signal produced at the Q output, as shown in FIG. 4C, has a frequency one half the frequency of the square wave shown in FIG. 4B. The Q output of the multiplier circuit 320 provides one input of a NOR gate 322, the other input of which is derived from a counter 382 in a manner to be presently described, which input is shown in FIG. 4K. Such input to the NOR gate 322 is initially low and therefore its output, as shown in FIG. 4H, will be the inverse of the Q output of the multiplier circuit 320. At time t 5 when the input to the NOR gate 322 derived from the counter becomes high, as shown in FIG. 4K, the output from such NOR gate becomes low, as shown in FIG. 4H. The wave form shown in FIG. 4K also constitutes an input to a NOR gate 324 which is connected as an inverter. The output of the NOR gate 324 is connected as one input to a NOR gate 326, the other input thereof being derived from the Schmitt trigger 300. Initially, when the signal shown in FIG. 4K is low, the corresponding input to the NOR gate 326 is high, whereby the output thereof, as shown in FIG. 4I, is low. On the other hand, when the signal shown in FIG. 4K becomes high at time t 5 , the corresponding input to the NOR gate 326 becomes low, and the output thereof follows the output from the Schmitt trigger 300, but is inverted. The output from the NOR gate 326 is shown in FIG. 4I. The NOR gates 322 and 326 are coupled as inputs to a NOR gate 328 which responds to the signals shown in FIGS. 4I and 4H to furnish the signal shown in FIG. 4G. It will be noted that when the first tone is present during the interval t 1 -t 4 , the output of the NOR gate 328 is a square wave having half the frequency of the signal shown in FIG. 4A, wherein, during the interval t 5 -t 9 the frequency of the square wave at the output of the NOR gate 328 is the same as the frequency of the second tone. The signal at the output of the NOR gate 328 is applied to a reference circuit 330 which is a voltage doubler and acts to rectify the signal from the NOR gate 328 and provide a reference voltage on the conductor 332. The signal from the NOR gate 328 is also applied to a filter 334 comprised of a pair of capacitors 336 and 338 and an inductor 340 having ten taps 340a to 340j. One end 340k of the inductor 340 is connected to the junction of the capacitors 336 and 338. A terminal block 342 has a plurality of electrical sockets 342a-342j respectively coupled to the taps 340a-340j. Also, the block has a set of sockets 344a-344d respectively coupled to the collectors of four PNP switching transistors 346a-346d, the emitter of each of which switching transistors is coupled to the supply voltage. Associated with the block 342 is a plug 348, having pins 348a-348j and 350a-350d. The plug 348 is adapted to be programmed to set the code to which the decoder 280 is to respond, by connecting jumper wires from selective ones of the pins 348a-348j to the pins 350a-350d. As an example, the pins 348i, 348g, 348e, and 348b are respectively connected by way of jumper wires 352 to the pins 350a-350d, so as internally to program the decoder to receive a sequence of four predetermined tones. However, as will be described, the decoder 280 has other elements so connected that it requires a sequence of only two tones to become actuated. Initially, during the interval t o -t 5 the transistor 346a is conducting, whereas the transistors 346b-346d are initially nonconducting, the reasons for which will be described in greater detail hereinafter. Then, the supply voltage on the emitter of the transistor 346a is coupled through its collector, through the socket 344a, the pin 350a, the corresponding jumper 352, the pin 348i, the socket 342i, whereby that portion of the inductor 340 between the tap 340i and the end 340k will be in the filter 334. The resonant frequency of the filter 334 will be determined by the value of such inductance and the value of the capacitors 336 and 338. When there is applied to the filter 334 a signal having such resonant frequency, a substantial output will be generated. In a manner to be described hereinafter, the resonant frequency of the filter 334 charges at time t 5 because a different amount of inductance has been switched into the circuit (the inductance between the tap 340g and the end 340k). If the square wave output of the NOR gate 328 (FIG. 4G) during the interval t 1 -t 5 has a frequency corresponding to the resonant frequency of the filter 334 prior to t 5 , the output of such filter will have the substantial amplitude shown in FIG. 4D during the interval t 1 -t 5 . If the square wave output of the NOR gate 328 during the interval t 5 -t 8 has a frequency corresponding to the resonant frequency of the filter 334 during that interval, then the amplitude of the output during that interval will also be substantial, as shown in FIG. 4D. FIG. 4D depicts the characteristic of the output of the NOR gate 328 that it takes some time to increase to full amplitude when the tone begins (on the order of 5-50 ms. for example) and some time to decrease to zero amplitude after the tone terminates (on the order of 20 ms. for example). The output of the filter 334 is applied to a rectifier 362 which detects the envelope of the filter output (i.e., it rectifies such output), as long as the output exceeds the reference voltage on the conductor 332 produced by rectification of the entire demodulated signal. The rectified signal, as shown in FIG. 2E, is applied to a clipper 364. When the amplitude of the rectified signal increases to level "1" at a time t 2 , shortly after the first tone has commenced, the clipper 364 will operate and its output becomes low, as shown in FIG. 4F. The switching level "1" of the clipper 364 is determined by the bias furnished by the resistors 363a and 363b applied to its other input. When the first tone terminates at t 4 , the rectified signal begins to fall in amplitude in accordance with the decreasing amplitude of the envelope shown in FIG. 4D. When the rectified signal amplitude reaches the switching level at time t 5 , the output of the clipper 364 becomes high again and stays high until t 6 , at which time the rectified signal arising from the second tone has reached the switching level, thereby causing the clipper output to become low. Such output remains low until t 8 . At t 8 , shortly after the second tone terminates, the switching level of the clipper 364 is reached and the output of the clipper 364 becomes high, at which level it remains until an ensuing tone sequence. Coupled to the output of the clipper 364 is a resistor 366 and a capacitor 368 in series to the supply voltage, the juncture of the two being coupled to a NAND gate connected as an inverter 370. A diode 369 is coupled in parallel with the resistor 366. Subsequent to the last tone sequence applied to the decoder 280, the capacitor 368 had been rapidly charged through the diode 369. When the output of the clipper 364 becomes low at t 2 , the capacitor 368 discharges through the resistor 366 at a rate determined by the values of the resistor 366 and the capacitor 368. After the resultant delay, the voltage at the input to the inverter 370 reaches a value to cause same to switch, whereby its output becomes high. The inverter 370 is coupled to a Schmitt trigger 384. Referring to FIG. 2M, the output of the Schmitt trigger 384 is normally low. At time t 3 , after the above-mentioned predetermined delay has passed, the output of the inverter 370 becomes high, which causes the output of the Schmitt trigger 384 to become low. After the first tone terminates, at t 5 , the capacitor 368 is rapidly charged through the diode 369, causing the output of the inverter 370 rapidly to become low, thereby causing the output of the Schmitt trigger 384 to become high at time t 5 . After the predetermined delay has passed, following t 6 , that is, at time t 7 , the output of the Schmitt trigger 384 becomes low and remains low until t 8 which is shortly after termination of the second tone. The capacitor 368 is rapidly charged at t 8 , causing the output of the Schmitt trigger 384 to become high and to remain high until the next tone sequence. The delay between time t 2 , when the leading edge of the negative-going transition at the output of the clipper 364 becomes low, and time t 3 , when the output of the Schmitt trigger 384 becomes low, is determined by the values of the resistor 366 and the capacitor 368, which predetermined delay may be on the order of 30 ms., for example. Such delay insures that noise or other short duration signals will not unintentionally trip the decoder 280. The output of the inverter 370 is also coupled to a timing circuit 372, comprising a resistor 374, a diode 376 coupled in parallel therewith, and a capacitor 378 coupled to ground. The output of the timing circuit 372 is coupled to a NAND gate connected as an inverter 380, which in turn is coupled to the counter 382. When the output of the inverter 370 becomes high at t 3 , the capacitor 378 is rapidly charged through the diode 376, causing the output of the inverter 380 to become low, as shown in FIG. 4P. At t 5 , shortly after the first tone terminates, the output of the NAND gate 370 becomes low and the capacitor 378 begins to discharge through the resistor 374. If no second tone is received, then the capacitor 378 will discharge to the point where the output of the inverter 380 will become high. However, in the example of FIG. 4, a second tone of the proper frequency is received at t 4 . At t 7 , after the delay furnished by the capacitor 368 and the resistor 366, the output of the inverter 370 again becomes high rapidly charging the capacitor 378 back to its maximum value, as shown in FIG. 4N. When the second tone terminates, the capacitor 378 again discharges, but because no subsequent tone is received, it discharges to a level at t 9 when the output of the inverter 380 becomes high (FIG. 4P). Thus, the output of the inverter 380 is low from t 3 to t 9 . The transistors 346a to 346d are sequentially rendered conductive by, and certain of the inputs to the gates 322 and 324 are derived from, a counter 382. The counter 382 has substantially the same construction as the counter 176 used in the encoder of FIG. 1. In this form, the "0" to "3" outputs are used, so those are the only ones shown. The CE input is grounded, the R input is coupled to the inverter 380, and the C input is coupled to the Schmitt trigger 384. The "0" output is coupled as an input to an NPN transistor 386a, the collector of which transistor is coupled to the base of the transistor 346a. The transistors 386a and 346a define an electronic switch. The "1", "2" and "3" outputs are respectively coupled to NPN transistors 386b, 386c and 386d, the collectors of which transistors are respectively connected to the bases of the transistors 346b, 346c, and 346d. Associated pairs of the transistors (e.g., 386b and 346b) define electronic switches. Initially, the "0" output of the counter 382 is high (FIG. 4J), thereby actuating the switch consisting of the transistors 386a and 346a, to cause the associated portion of the inductor 340 to be coupled in circuit in the filter 334, as previously described. At time t 3 , the reset input (FIG. 4P) becomes low, whereupon the counter 382 is in condition to be stepped. As can be seen in FIG. 4M, the first positive transition of the C input to the counter 382 occurs at time t 5 , on termination of the first tone, causing the counter 382 to step so that the "1" output becomes high (FIG. 4K). The transistors 386b and 346b conduct, thereby coupling in the filter circuit 334 another portion of the inductor 340, as previously described. Similarly, when the "2" output of the counter 382 becomes high (FIG. 4L), in response to a clock pulse at t 8 , another portion of the inductor 340 is connected in circuit with the filter circuit 334 to change the resonant frequency thereof. Since the decoder 280 is arranged to respond to only two tones, there will be no further clock pulses to cause the counter 382 to step to cause the "3" output to become high. The connections are there, however, so that the decoder 280 can be modified to accept more than two tones. The jumper connected to terminals 350c and 350d would not ordinarily be used if the decoder responds only to two tones. The "1" and "3" outputs of the counter 382 are coupled by way of diodes 388 and 390, across a resistor 392, to the gates 322 and 324 to provide the inputs thereto described previously. At time t 8 , the R input to the counter 382 becomes high, whereupon the counter 382 is reset to cause the "0" output to become high and the rest of the outputs "1"-"3" to be low. Thus, the counter 382 is reset either when the two-tone sequence is completed or when a second tone is not received. The "2" output of the counter 382 is coupled through a resistor 400 to the base of an emitter follower NPN transistor 402, the collector of which is coupled to the supply voltage and the emitter of which is coupled to a resistor 404 connected to ground. The emitter of the transistor 402 is coupled through filtering elements 406 to the control electrode of an SCR 408, the cathode of which is coupled to ground and the anode of which is coupled through a large resistor of for example, 100K to the supply voltage. The anode of the SCR 408 is also coupled to the supply voltage through a diode 412, the relay winding 272 and the normally closed contacts 56 of the switch 52. A bulb 414 and a diode 416 are coupled in series between the contacts 56 and the anode of the SCR 408. The anode of the SCR 408 is coupled through a resistor 418 and a diode 420 to a NAND gate connected as an inverter 422. A resistor 424 is connected across the resistor 418 and the diode 420. A capacitor 426 is connected from the input of the inverter 422 to the supply voltage. The output of the inverter 422 is coupled to the second input of the NOR gate 214 (FIG. 1). The transistor 402 is rendered conductive by the "2" output of the counter 382 becoming high at time t 8 , after termination of the second tone, thereby causing a positive input to be applied to the control electrode of the SCR 408, rendering it conductive to cause current flow from the supply voltage, through the normally closed contacts 56, the relay winding 272, the diode 412 and the SCR 408. The current flow through the winding 272 closes the contacts 270, thereby enabling the speaker 268 so that it can reproduce the voice message which follows the tones (see FIG. 4A). Also, current flows from the supply voltage through the contacts 56, the bulb 414, the diode 416 and the SCR 408, to illuminate the bulb 414 thereby apprising the possessor of the receiver 250 that he is being paged. The relay winding 272 and the bulb 414 will remain energized until the switch 52 is actuated to open the contacts 56. Such actuation disrupts current flow through the winding 272 to open the contacts 270 and also extinguishes the bulb 414. It will be remembered that another set of contacts 54 of the same switch 52 is used to initiate transmission of a sequence of tones by the encoder. In order to so use a common switch, it is necessary to insure that actuation of the switch 52 to extinguish the bulb 414 and de-energize the relay winding 272 does not also send out a tone sequence. To that end, the circuitry 418-424 is provided. When the SCR 408 is rendered conductive at t 8 , shortly after termination of the second tone, a path is provided for the capacitor 426 to charge rapidly through the diode 420 and the resistor 418, thereby causing the output of the gate 422 to become high, as shown in FIG. 4Q. Such high output furnishes a high input to the NOR gate 214 which disables the encoder 50. When the switch 52 is actuated to open the contacts 56, the capacitor 426 discharges slowly to maintain the high input to the NOR gate 214 high for, say, one second. Thus, if the switch 52 is only momentarily actuated, after the decoder 280 receives a coded signal, the encoder 50 will not produce a tone sequence. However, if the switch 52 is maintained actuated for more than one second, then the encoder will produce a sequence of tones. The decoder 280 responds to a sequence of two tones, by virtue of the input to the transistor 402 being derived from the "2" output of the counter 382. By moving the connection to the "3" output, the decoder 280 would be responsive to a sequence of three tones. What has been described, is a decoder in which the frequency of every other tone applied to the filter is multiplied by a predetermined multiplier, in this instance, that multiplier being one half, and the remaining tones are applied to the filter without any change in frequency. In this way, a single filter 334, having one tapped inductor, is able to respond to twenty tones. These principles can be used in a decoder to respond to any number of tones in sequence. Also, because of the smaller size of the encoder 50 and the decoder 280, they can be readily placed in the same package. It is believed that the invention, its mode of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that, while preferred embodiments of the invention have been shown and described for illustrative purposes, the structural details are, nevertheless, capable of wide variation within the purview of the invention as defined by the appended claims.

The encoder in such system generates a sequence of tones in which every other tone is selected from a first group of tones in one band of frequencies, and the remaining tones in the sequence are selected from a second group of tones in another band of frequencies. The tones in the second group are respectively harmonically related to the tones in the first group, such as having frequencies double the respective frequencies of the tones in such second group. The tones are generated by an oscillator in the encoder, every other tone being multiplied by 1/2, for example. Circuitry, coupled to the oscillator and to the multiplier, alternately delivers the divided and undivided tones, to create the afore-mentioned sequence of tones. The oscillator has associated therewith a switchable impedance, predetermined amounts of which are sequentially switched into the oscillator to cause it to produce the sequence of tones. To minimize energy loss, circuitry is provided to insure that the phase of the tones is substantially continuous as the different amounts of impedance are switched into the oscillator. A programming device enables internal fixing of the frequencies of certain tones, which tones represent the identification of the encoder. A manual selector enables external selection of the frequencies of other tones which represent other information relative to the encoder.

BACKGROUND This description relates to reverse link power control. ACRONYMS AND ABBREVIATIONS 1x-EVDO Evolution Data only, CDMA2000 family standard for high speed data only wireless internet access AN Access Network API Application Programmable Interface ASIC Application Specific Integrated Circuit AT Access Terminal BIO-SC Basic Input/Output-System Controller CDMA Code-Division Multiple Access CPU Central Processing unit CSM5500 ASIC Qualcomm Inc. modem ASIC CSM5500 Drivers Qualcomm Inc. modem ASIC Driver and API FCS Frame Check Sequence FER Frame Error Rate FLM Forward Link Modem IP Internet Protocol PCT Power Control Threshold PCT RNi Power Control Threshold computed at ith RN PCT RNC Power Control Threshold computed at RNC RAN Radio Access Network RL Reverse Link or uplink-from mobile to base station. RLILPC Reverse Link Inner-Loop Power Control RLM Reverse Link Modem RLOLPC Reverse Link Outer-Loop Power Control RLOLPC-RN Power Control Algorithm running on RN RLOLPC-RNC Power Control Algorithm running on RNC RN Radio Node or Base Station RN-BIO-SC Radio Node BIO-SC Card or module RNC Radio Network Controller RNSM Radio Network Serving Module RPC Reverse Power Control RTCHMO Reverse Traffic Channel MAC Object SDU Selection and Distribution Unit SINR Signal-to-Interference Ratio (E b /I t ) Capacity of a cellular system represents the total number of mobile users (access terminals or ATs) that can be supported by the system. Capacity can be an important factor for cellular service providers, since it directly impacts revenue. CDMA wireless communications systems offer improved capacity and reliable communications for cellular and PCS systems. In a CDMA system, each AT transmit signal utilizes a different pseudo random sequence signal that appears as noise to other ATs. This enables many ATs to transmit on the same frequency. However, each AT's transmitted signal contributes to interference to the transmitted signal of all other users. Thus, the total number of users supported by the system is limited by interference. Therefore, reducing the amount of interference in a CDMA wireless communications system increases capacity. A typical problem in a CDMA cellular environment is the near/far problem. This entails the scenario where the transmit power of an AT near the RN may drown out an AT which is far from the RN. This is effectively mitigated by controlling the transmit power of each AT via power control scheme implemented by the access network (AN). AN continuously commands each AT to increase or decrease its transmit power to keep them all transmitting at the minimal power required to achieved the configured error rate for the operating data rate and maintain the overall balance of the power while reducing the interference in the area of coverage. In a CDMA 1x-EVDO system (see e.g., CDMA2000 High Data Rate Packet Data Air Interface Specification, 3GPP2 C.S0024, Version 4.0, Oct. 25, 2002), the reverse link operates in CDMA and hence reverse link power control is needed. The reverse link power control comprises of an open-loop power control (also called autonomous power control) and closed-loop power control. Open-loop power control is implemented in an AT, based on the received pilot-power of an RN. Closed-loop power control includes inner loop power control and outer loop power control, both of which are performed by the access network. Typical operation of a closed loop power control can be found in textbooks (see e.g., Vijay K. Garg, IS-95 CDMA and CDMA2000 Cellular/PCS Systems Implementation, Chapter 10, Prentice Hall, 1999, R. Steele. Mobile Radio Communications. Pentech Press, London, England, 1992, and Rashid A. Attar and Eduardo Esteves, A Reverse Link Outer-Loop Power Control Algorithm for CDMA2000 1xEV Systems, Proceedings of ICC, April 2002). Also, additional details can be found in e.g., U.S. Pat. No. 6,633,552, titled Method And Apparatus For Determining The Closed Loop Power Control Set Point In A Wireless Packet Data Communication System, and issued on Oct. 14, 2003, U.S. Pat. No. 6,507,744, titled Outer Loop Power Control Method During A Soft Handoff Operation, and issued on Jan. 14, 2003, and U.S. Pat. No. 5,884,187, titled Outer Loop Power Control Method During A Soft Handoff Operation, and issued on Mar. 16, 1999. A typical implementation is now described. FIG. 1 illustrates a system 100 implementing the basic closed loop power control operation. In closed loop power control, power adjustment is done at an AT 105 in accordance with the power control commands received from an RN 110 (also referred to as a base station 110 ). RN 110 sends up/down commands to each active AT (e.g., 105 ) to ensure that the AT transmit signal is received at the RN 110 at the lowest possible power required for the RN 110 to receive the data correctly at the operating rate. In a reverse link inner-loop power control (RLILPC) mechanism 115 , the reverse link signal to the interference-noise ratio (SINR) is continuously and frequently measured at a modem receiver of RN 110 . These frequent measurements track rapid channel variations of the link between the AT 105 and the RN 110 and facilitate accurate power control even when the AT 105 is in a deep fade. This measured of SINR is compared to a threshold value called ‘power control threshold’ (PCT). If the measured value is greater than PCTmax (=PCT+PCTDelta), the RPC bit is cleared. If the measured value is less than PCTmin (=PCT−PCTDelta), RPC bit is set. PCTDelta is a small value that provides an interval around the PCT. If the PCT is within this interval, the RPC bit status is unchanged from the previous value. Setting the RPC bits Cup decisions') commands AT 105 to increase its transmit power by a pre-determined step size, say ‘x’ dB. Clearing RPC bits (‘down decisions’) commands the AT 105 to decrease its transmit power by ‘x’ dB. The step size is negotiated a priori between RN 110 and AT 105 . Frame Error Rate (FER) is defined as a ratio of the bad frames to the total number of frames received by the RN 110 . A frame with correct physical layer frame check sequence (FCS) is defined to be a good frame. In 1x-EVDO, the physical layer cyclic redundancy code (CRC) can be used to determine good or bad frames. In a reverse link closed outer-loop power control (RLOLPC) algorithm 120 , the PCT is adaptively adjusted such that the configured target FER is achieved and maintained for the duration of the connection. (A target reverse link FER of 1% is considered typical for wireless networks). The RLOLPC algorithm 120 is implemented in a RNC 125 . It should be noted that there is another parameter beside FCS that is used in the voice application in CDMA system. This parameter is called the quality metric, which is an indication of how “bad” the bad frame is. For voice, it may be beneficial to play out a bad packet in order to maintain the perception of a good voice quality. Therefore, even the bad packets are still sent to the RNC 125 from the RN 110 with the marking for a correct FCS and a quality metric. It's up to the RNC 125 to determine if the quality metric meets the criteria for the packet to be used even when the FCS is incorrect. Typical operation of the RLOLPC algorithm 120 is described now. Upon reception of a RL frame with bad FCS, PCT is increased by a pre-set large value (e.g., 0.5 dB), which is termed a good frame PCT Delta. Upon reception of a RL frame with good FCS, PCT is decreased by a pre-set small value (e.g., 0.5 dB), which is termed a bad frame PCT Delta. Given the values of RL FER and the good frame PCT Delta, the bad frame PCT Delta value is computed as follows: Bad Frame PCT Delta=Good Frame PCT Delta(1−RL FER)/RL FER (Note that this same equation can be used to compute the good frame PCT Delta given the values of RL FER and the bad frame PCT Delta.) Before a connection establishment, or if there is no data on a RL, the PCT is set to a pre-set high value to facilitate rapid reverse link acquisition. A new value of the PCT is computed upon reception of each good/bad RL frame and an updated PCT is input into the RN modem receiver and to the RLILPC algorithm 115 . FIG. 2 illustrates an example system 200 , in which AT 105 is in a L-way soft hand-off (i.e., AT 105 is communicating with L RNs, e.g., RN 1 110 , RN 2 205 , and RN L 210 , at the same time). The selection and distribution unit (SDU) (not shown) at the RNC 125 determines which received frame from all the different ‘legs’ should be used. In addition it determines if correct or incorrect received frame indication needs to be send to the RLOLPC algorithm 120 on each frame boundary. The RLOLPC algorithm 120 uses this information to compute the overall PCT for the AT 105 . This PCT value is sent to all L RNs involved in the soft hand-off. SUMMARY OF INVENTION In one aspect, there is a method of performing reverse link power control in a mobile network having a plurality of first modem devices that receive and transmit signals to wireless access terminals (ATs) and a second device in communication with the plurality of first devices. The method includes transitioning execution between a first and a second loop to control reverse link power of one of the ATs, the transition being based on a state of a connection. The first control loop executes at one of the first devices and the second loop executes at the second device. Other examples can include one or more of the following features. The transitioning can include synchronizing between the first control loop and the control loop based on a change of the state. The change of the state of the connection can include transitioning from the connection not in handoff to the connection in soft handoff. The method can include transmitting to the second control loop a value for a power control threshold calculated by the first control loop. The transmitting can include transmitting the value for the power control threshold during transmission of handoff-related data. The method can include deriving a power control threshold using the first or second control loop. The method can include generating, by the one of the first devices, an indicator representing quality of a signal received from the one of the ATs, and calculating a power control threshold using the indicator. The method can include preventing transmission of a packet from the one of the first devices to the second device if the packet is associated with a bad indication. The method can include transmitting the bad indication to the second device. The method can include determining good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The state of the connection can include the connection not in handoff, the connection in softer handoff, or the connection in soft handoff. The method can include communicating between the first devices and the second device using Internet Protocol (IP) or asynchronous transfer mode (ATM). In another aspect, there is a method of performing reverse link power control in a mobile network having a plurality of first modem devices that receive and transmit signals to wireless access terminals (ATs) and a second device in communication with the plurality of first devices. The method includes deriving, by one of the first devices, a first power control threshold (PCT) value for reverse link power of one of the access terminals (ATs) and deriving, by the second device, a second power control threshold (PCT) value for reverse link power of the one of the ATs. The method also includes transmitting the second power control threshold (PCT) value using a data traffic path and selecting the first PCT value or the second PCT value. Other examples can include one or more of the following features. The transmitting can include transmitting using User Datagram Protocol or Generic Route Encapsulation protocol. The transmitting can include transmitting the second power control threshold (PCT) value based on a state of a connection. The state of the connection can include the connection in soft handoff. The second PCT value can be selected when the second PCT value is received at the one of the first devices. The first PCT value can be selected when a connection is not in handoff or a connection is in softer handoff. The second PCT value can be selected when a connection is in soft handoff. The method can include generating, by the one of the first devices, an indicator representing quality of a signal received from the one of the ATs, and calculating the first PCT and the second PCT using the indicator. The method can include preventing transmission of a packet from the one of the first devices to the second device if the packet is associated with a bad indication; and transmitting the bad indication to the second device. The method can include determining good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The method can include communicating between the first devices and the second device using Internet Protocol (IP) or asynchronous transfer mode (ATM). In another aspect, there is a system for performing reverse link power control in a radio access network (RAN). The system includes a first modem device and a second device in communication with the first device over a network. The first modem device receives and transmits signals to a wireless access terminal (AT). The first device is configured to execute a first loop to control reverse link power of the AT based on a first state of a connection. The second device is configured to execute a second loop to control reverse link power of the AT based on a second state of the connection and to synchronize the second loop with the first loop during a transition from the first state to the second state. Other examples can include one or more of the following features. The first state of the connection can include the connection not in handoff or the connection in softer handoff. The second state of the connection can include the connection in soft handoff. The second device can be configured to obtain a power control threshold calculated by the first control loop. The second device can be configured to obtain a power control threshold calculated by the first control loop during transmission of handoff-related data. The first device can be configured to derive a power control threshold using the first control loop. The first device can be configured to generate an indicator representing quality of a signal received from the AT and to calculate a power control threshold using the indicator. The first device can be configured to prevent transmission of a packet from the first device to the second device if the packet is associated with a bad indication and to transmit the bad indication to the second device in place of the packet. The first device can be configured to determine good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The first device and the second device can communicate using Internet Protocol (IP) or asynchronous transfer mode (ATM). In another aspect, there is a system for performing reverse link power control. The system includes a first modem device and a second device in communication with the first device over a network. The first modem device receives and transmits signals to a wireless access terminal (AT). The first device is configured to derive a first power control threshold (PCT) value for reverse link power of an AT. The second device is configured to derive a second power control threshold (PCT) value for reverse link power of the AT and to transmit the second power control threshold (PCT) value to the first device using a data traffic path. Other examples can include one or more of the following features. The first device can be configured to transmit the second power control threshold (PCT) value to the first device over the data traffic path using User Datagram Protocol or Generic Route Encapsulation protocol. The first device can be configured to select the first PCT value or the second PCT value. The first device can be configured to select the second PCT value when the second PCT value is received at the first device. The first device can be configured to select the first PCT when the connection is not in handoff or the connection is in softer handoff. The first device can be configured to select the second PCT value when the connection is in soft handoff. The first device can be configured to generate an indicator representing quality of a signal received from the AT and to calculate the first PCT using the indicator. The first device can be configured to prevent transmission of a packet from the one of the first devices to the second device if the packet is associated with a bad indication and to transmit the bad indication to the second device. The first device can be configured to determine good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The first device and the second device can communicate using Internet Protocol (IP) or asynchronous transfer mode (ATM). In another aspect, there is a computer program product, tangibly embodied in an information carrier, for performing reverse link power control in a mobile network having a plurality of first modem devices that receive and transmit signals to wireless access terminals (ATs) and a second device in communication with the plurality of first devices. The computer program product includes instructions being operable to cause data processing apparatus to transition execution between a first and a second loop to control reverse link power of one of the ATs, where the transition is based on a state of a connection, and the first control loop executes at one of the first devices and the second loop executes at the second device. Other examples can include one or more of the following features. The computer program product of can include instructions operable to cause the data processing apparatus to synchronize between the first control loop and the control loop based on a change of the state. The change of state of the connection can include transitioning from the connection not in handoff to the connection in soft handoff. The computer program product can include instructions operable to cause the data processing apparatus to transmit to the second control loop a value for a power control threshold calculated by the first control loop. The computer program product can include instructions operable to cause the data processing apparatus to transmit the value for the power control threshold during transmission of handoff-related data. The computer program product can include instructions operable to cause the data processing apparatus to derive a power control threshold using the first or second control loop. The computer program product can include instructions operable to cause the data processing apparatus to generate, by the one of the first devices, an indicator representing quality of a signal received from the one of the ATs, and calculate a power control threshold using the indicator. The computer program product can include instructions operable to cause the data processing apparatus to prevent transmission of a packet from the one of the first devices to the second device if the packet is associated with a bad indication, and transmit the bad indication to the second device. The computer program product can include instructions operable to cause the data processing apparatus to determine good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The state of the connection can include the connection not in handoff, the connection in softer handoff, or the connection in soft handoff. The computer program product can include instructions operable to cause the data processing apparatus to communicate between the first devices and the second device using Internet Protocol (IP) or asynchronous transfer mode (ATM). In another aspect, there is a computer program product, tangibly embodied in an information carrier, for performing reverse link power control in a mobile network having a plurality of first modem devices that receive and transmit signals to wireless access terminals (ATs) and a second device in communication with the plurality of first devices. The computer program product includes instructions being operable to cause data processing apparatus to derive, by one of the first devices, a first power control threshold (PCT) value for reverse link power of one of the access terminals (ATs), derive, by the second device, a second power control threshold (PCT) value for reverse link power of the one of the ATs, transmit the second power control threshold (PCT) value using a data traffic path, and select the first PCT value or the second PCT value. Other examples can include one or more of the following features. The computer program product can include instructions operable to cause the data processing apparatus to transmit using User Datagram Protocol or Generic Route Encapsulation protocol. The computer program product can include instructions operable to cause the data processing apparatus to select the second PCT value when the second PCT value is received at the one of the first devices. The computer program product can include instructions operable to cause the data processing apparatus to select the first PCT value when a connection is not in handoff or a connection is in softer handoff. The computer program product can include instructions operable to cause the data processing apparatus to select the second PCT value when a connection is in soft handoff. The computer program product can include instructions operable to cause the data processing apparatus to generate, by the one of the first devices, an indicator representing quality of a signal received from the one of the ATs, and calculate the first PCT and the second PCT using the indicator. The computer program product can include instructions operable to cause the data processing apparatus to prevent transmission of a packet from the one of the first devices to the second device if the packet is associated with a bad indication and transmit the bad indication to the second device. The computer program product can include instructions operable to cause the data processing apparatus to determine good or bad indication of a packet using a cyclic redundancy code (CRC) associated with the packet. The computer program product can include instructions operable to cause the data processing apparatus to communicate between the first devices and the second device using Internet Protocol (IP) or asynchronous transfer mode (ATM). Among the advantages of the system are one or more of the following. By reducing RNC-RN signaling (e.g., sending PCT only for connections in handoff), there is a reduced backhaul bandwidth consumption. Similarly, by reducing RN-RNC data traffic (e.g., sending only an indication of bad frames to a RNC, excluding the payload), there is a reduced backhaul bandwidth consumption. Other features and advantages will become apparent from the following description and from the claims. DESCRIPTION FIG. 1 is a block diagram illustrating reverse link power control in an example CDMA System. FIG. 2 is a block diagram illustrating reverse link power control in another example CDMA System. FIG. 3 is a block diagram illustrating a system for distributed reverse link power control. FIG. 4 is a block diagram depicting an example system for reverse link power control on the RN. FIG. 5 is a block diagram depicting an example system for reverse link power control on the RNC. FIG. 6 ( a ) depicts an example data structure of a message from RNC to RN. FIG. 6 ( b ) depicts an example data structure of a message from RN-BIO-SC to RLM. FIG. 3 illustrates a 1xEV-DO Radio Access Network (RAN) 300 . The RAN 300 can be built entirely on IP technology, all the way from an AT 305 to a network connection to the Internet (e.g., via a RNC 310 ), thus taking full advantage of the scalability, redundancy, and low-cost of IP networks. The entire service area of a wireless access provider may comprise one or more IP RANs 300 . Each IP RAN 300 can include many radio nodes (RNs), e.g., RN 315 and RN 320 , and one or more radio network controllers (RNC), e.g., 310 . The RNs 315 and 320 and the RNC 310 are connected over an IP (backhaul) network 330 , which supports many-to-many connectivity between RNs 315 and 320 and RNC 310 , and any other RNs and RNCs that may be part of RAN 300 . In presence of an IP connectivity between RNs 315 and 320 and RNC 310 , transmission of PCT values as IP packets over IP backhaul 330 to connections on all RNs can generate a high amount of signaling message transmission. Each RNC could potentially support 100s of RNs and the signaling message overhead for PCT message transmission could be a significant portion of the overall backhaul traffic. System 300 implements a distributed approach to reduce the signaling messaging over IP backhaul 330 , as described in more detail below, since signaling messaging has priority over data, which can cause significant reduction of data throughput to the end user. In system 300 , the RLOLPC functionality (e.g., updating the PCT) is distributed across RNs 315 and 320 and RNC 310 . This distribution is accomplished by using a RLOLPC-RNC module 335 for RLOLPC functionality in RNC 310 and a RLOLPC-RN module 340 for RLOLPC functionality in RNs 315 and 320 . In a general overview, system 300 uses RLOLPC-RNC module 335 or RLOLPC-RN module 340 based on the handoff state of AT 305 . In general, handoff represents the migration of a connection of AT 305 from one RN to another RN. When AT 305 is in communication with only one RN, for example RN 315 , then AT 305 is not in handoff. When AT 305 migrates, for example, from RN 315 to RN 320 , then AT 305 is in handoff. Soft handoff represents the overlapping coverage area of RNs 315 and 320 , where AT 305 can communicate with both RN 315 and RN 320 at the same time. A soft handoff is sometimes referred to as a make before break connection. Softer handoff represents the overlapping coverage area between different sectors for the same RN. If the AT 305 is not in handoff or is in softer handoff, the RLOLPC-RN module 340 of the serving RN handles the RLOLPC functionality. For example, if AT 305 is in communication only with RN 315 or is in a coverage area of RN 315 where AT 305 can communicate with multiple sectors of RN 315 , then the RLOLPC-RN module 340 of the RN 315 handles the RLOLPC functionality. As described above, the RLOLPC algorithm increases or decreases the PCT value based on whether the reverse link receives good or bad frame input. The RLOLPC-RN module 340 can determine bad or good frame input locally at the RN 315 by using the CRC state. Because system 300 is a 1xEV-DO system, there is no quality metric assigned to each received packet. Since the packet of data is either good or bad, the CRC state indicates the usefulness of the packet. In this scenario, the RLILPC 350 receives the PCT locally (shown by arrow 355 ) and not from the RNC 310 (shown by arrow 360 ). Because no information has to be transferred between RN 315 and RNC 310 , this local PCT calculation advantageously generates bandwidth savings on both reverse and forward links in backhaul 330 . Also, there is a saving of processor bandwidth in RNC 310 , since it does not have to execute an RLOLPC algorithm for this connection. If the AT 305 is in soft handoff, the RLOLPC-RNC module 335 of the serving RNC handles the RLOLPC functionality. For example, if AT 305 is in communication with both RN 315 and RN 320 , then the RLOLPC-RNC module 335 of the RNC 310 handles the RLOLPC functionality. In this scenario, like the scenario above, the RN (e.g., 315 and/or 320 ) receiving the packet determines whether it is a good or bad frame using the CRC state. If the RN (e.g., 315 and/or 320 ) determines the packet is a good frame, the RN forwards the packet to RNC 310 . If the RN (e.g., 315 and/or 320 ) determines the packet is a bad frame, the RN does not forward the packet to RNC 310 . Instead, the packet is dropped at the RN and an indication of a bad frame is sent to RNC 310 . This indication is smaller than sending the entire received packet, hence less traffic is generated on the backhaul 330 . An SDU in RNC 310 determines which leg (e.g., the communication between AT 305 and RN 315 or the communication between AT 305 and RN 320 ) is providing the good frame, if any, and inputs the RLOLPC-RNC module 335 accordingly. The RLOLPC-RNC module 335 generates the PCT and sends it to the applicable RNs using, for example, a packet. The PCT packet may be treated as a signaling packet and sent using a signaling path, (e.g., using Transmission Control Protocol (TCP)). This signaling path can be slower but more reliable than the data traffic path. In another example, the PCT packet can be treated as a data packet and sent using a data traffic path (e.g., using User Datagram Protocol (UDP) or Generic Route Encapsulation (GRE) protocol). This data traffic path can be faster but less reliable than the signaling path. For each RN, the PCT for all connections on each carrier in that RN can be multiplexed into one packet and sent to the respective RN. Also, the PCT values for all of the RNs can be multiplexed into one packet and multicast to all of the RNs. These examples of using a single packet advantageously saves bandwidth on the forward link of the backhaul 330 . Sending only a bad frame indication instead of the entire bad frame with appropriate markings advantageously generates bandwidth savings on the backhaul 330 . Also, there is a saving of processor bandwidth in the RNs since the RLOLPC-RN module 340 is not run for this connection. System 300 coordinates RLOLPC between the RLOLPC-RNC module 335 and the RLOLPC-RN module 340 for PCT input into the RLILPC 350 as the connection (with AT 305 ) enters handoff or exits handoff. System 300 coordinates RLOLPC in a number of ways. One way to coordinate RLOLPC is to transition the RLOLPC from RN to RNC and back to RN as connection (with AT 305 ) enters and exists handoff and to synchronize the RLOLPC to generate the same PCT while RLOLPC is transitioned. To start the description of this process, the AT 305 is not in handoff and is communicating with RNC 310 only through RN 315 . At some point, as AT 305 moves closer to RN 320 , AT 305 enters an area where AT 305 can communicate with RNC 310 through both RN 315 and RN 320 (a soft handoff condition). Once RNC 310 detects this condition, which requires the connection to enter into handoff, the RNC 310 requests the channel-element resources from target RN 320 and has to update the source RN 315 with the number of legs in the handoff (in this case 2). During these transactions, source RN 315 responds with the latest value of PCT to initialize the RLOLPC-RNC module 335 in RNC 335 . During resource allocation on target RN, the RNC 335 uses this PCT value to prime the target RN RLILPC 350 . Once initialized, the RLOLPC-RNC module 335 determines the PCT and transmits the value to the RNs 315 and 320 s described above. This transmission of the PCT from the RLOLPC-RN 340 to the RLOLPC-RNC 335 enables the RLOLPC-RNC 335 to become synchronized with the RLOLPC-RN 340 . The RLOLPC-RNC 335 can then take over the RLOLPC functionality seamlessly from the RLOLPC-RN 340 . Once RNC detects the condition that AT needs to leave the handoff state, it has to update the last remaining leg with the number of handoff legs. The latest value of PCT can be also sent to RN at this time, before the periodic update time. Once the RN receives the above message, the RN switches to run RLOLPC (using the RLOLPC-RN 340 ) and generates the PCT locally (e.g., at the RN) for this connection. Another way to coordinate RLOLPC is to simultaneously run RLOLPC in both RLOLPC-RN 340 and RLOLPC-RNC 335 . Unlike the above examples, in this scenario, the RNs send a bad frame indication to the RNC 310 , even when in a no handoff state, because RLOLPC-RNC 335 continuously calculates PCT, regardless of the handoff state. In this way, both RLOLPC-RN 340 and RLOLPC-RNC 335 are synchronized with each other. When, however, the AT 305 is in a no handoff or softer handoff state, RNC 310 does not transmit its PCT value to the RNs. RNs 315 and 320 are configured such that when they do not receive a PCT value from the RNC 310 they use the PCT value calculated by the RLOLPC-RN module 340 . When the AT 305 moves into a soft handoff state, RNC 310 starts transmitting the PCT value calculated by RLOPC-RNC module 335 . When the RNs 315 and 320 receive a PCT value from the RNC 310 , they use that received PCT value instead of their locally calculated value. In other words, a PCT value received from the RNC 310 overwrites, or has higher priority than, the PCT value calculated by the local RLOLPC-RN module 340 . In some examples, the updated PCT is computed immediately after reception of the FCS information. However, since RLOLPC is a slow control loop, other examples input the PCT value to a RN modem receiver only once every ‘N’ RL frames. N represents a configurable parameter. In one example, N is set to 4 RL frames. Typically, each 1x-EVDO RL frame duration is 26.66 ms (see e.g., CDMA2000 High Data Rate Packet Data Air Interface Specification, 3GPP2 C.S0024, Version 4.0, Oct. 25, 2002) and hence an update period where N is set to 4 is 106.64 ms. This characteristic of the RLOLPC algorithm also facilitates transmission of consolidated PCT messages as opposed to individual PCT messages from RNC 310 (e.g., single PCT packets described above). FIGS. 4 and 5 illustrate the modules of RN 315 and RNC 310 in more detail. The modules that are running on RN 315 are shown in FIG. 4 . The modules that are running on RNC 310 are shown in FIG. 5 . In one example, the power control function at RN 315 is distributed across a BIO-SC 515 and modem line cards. The modem line card contains both a FLM module 440 and a RLM module 435 . In one example, the power control function at the RNC 310 resides on a RNSM card 540 . In the illustrated example, the inner loop power control module (RLILPC) 405 exists in a modem receiver 410 of the RN 315 . In the distributed approach for reverse link power control described above, the RLOLPC functionality is distributed across RNs and RNC based on all different handoff scenarios of the mobile (e.g., AT 305 ). In describing FIGS. 4-6 , the following handoff scenarios will be used, and referred to using its respective preceding letter. (a) Connection (AT) is not in hand-off. (b) Connection (AT) is in softer hand-off but not in soft hand-off. (c) Connection (AT) is in softer and soft hand-off. (d) Connection (AT) is in soft hand-off. Handoff areas are located at the cell site boundaries. As described above, an AT 305 is said to be in ‘soft’ handoff if the AT 305 is able to see pilot signals from multiple RNs (e.g., both RN 315 and RN 320 ). An AT 305 is said to be in ‘softer’ handoff if the AT is able to see pilot signals from multiple sectors of a single RN. The AT 305 reports the pilots seen to the AN (e.g., RAN 300 ) as part of the route update message (see e.g., CDMA2000 High Data Rate Packet Data Air Interface Specification, 3GPP2 C.S0024, Version 4.0, Oct. 25, 2002). At the AN, a determination of whether the AT 305 is in no/soft/softer handoff is made based on the number of pilots and corresponding PN offsets. For example: An AT is said to be in ‘three-way’ soft handoff if the AN resolves PN offsets of the three pilots reported in the route update message that corresponds to the three different RNs. For example, if the system is compliant with CDMA2000 High Data Rate Packet Data Air Interface Specification, 3GPP2 C.S0024, Version 4.0, dated Oct. 25, 2002, the maximum number of pilots allowed in soft/softer handoff is 6. The number of pilots in soft handoff is referred to as the “soft handoff count”. During connection establishment, the RNC call control module 505 passes Soft Handoff count down to its peer, a call control agent (CCA) module 510 on each RN in the handoff. This facilitates connection resource allocation at RNs. As described above, the power control for softer handoff can be identical to the no hand-off since the received signals of a specific AT 305 from different sectors on the specific RN are combined before generating FCS on that specific RN. Hence, there is no RNC involvement for softer handoff. The techniques described herein distinguish the fact that for situations (a) and (b), the updated PCT provided by RLOLPC-RN module 340 is sufficient without any necessity of RNC 310 communicating with a RN (e.g., RN 315 ). For situations (c) and (d), updated PCT from RLOLPC-RNC module 335 is sent to all RNs in the handoff (e.g., RN 315 and RN 320 ) and this overrides the updated PCT from the RLOLPC-RN 340 . Power Control when AT is not in Soft Handoff FIG. 4 illustrates portions of RN 315 , highlighting power control operation for scenarios (a) and (b). A reverse link modem 435 receives signals transmitted by the AT 305 . A received signal from the AT 305 is decoded and MAC packets are generated by the modem receiver. This is represented by a RL Decoder block 415 . A RTCHMO block 420 receives FCS and reverse rate indication of the received RL frame. The FCS information is input to the RLOLPC-RN module 340 and the updated PCT is computed. Updated PCT is input to a Decision Module 425 . Soft Handoff Count is a key parameter that is used by the Decision Module 425 to determine whether the AT 305 is in soft handoff. For no handoff or softer handoff, the value of Soft Handoff Count=1. In one example, this soft handoff count parameter is sent from the CCA 510 to a power control connection object module 430 at the RLM 435 during power control connection resource allocation. A connection list scanner module 435 scans a linked list of all active connections on the RN 315 . Entries to this list are added/deleted when a connection is opened/closed with an AT. The scan list is updated from interaction with the RN call control agent module 510 . Updates from the call control agent 510 are based on messages from its peer RNC call control 505 . In one example, upon reception of a timing callbacks (e.g., 4 RL frames detected by RL frame timing callback module 440 ) the entire active connection list is scanned. For each connection, the decision module 425 chooses appropriate PCT depending on the soft handoff count value. In cases (a) and (b), Soft Handoff Count=1 and hence PCT RN is chosen (e.g., the PCT value calculated by the RLOLPC-RN module 340 ). This value is used as the current input to RLILPC 405 . Using the latest PCT value, the RLILPC algorithm 405 determines RPC bits and transmits them to the mobile 305 on a forward link MAC channel. Since there is no involvement of RNC signaling, delays on the backhaul 330 are minimized and bandwidth conserved, as described above. Minimization of delay from the time the updated PCT is determined to the time it is used by RLILPC advantageously offers better power control on the reverse link. This can also help improve capacity on the forward link for high data rate wireless systems. Power Control when AT is in Soft Handoff FIG. 5 illustrates portions of RNC 310 and RN 315 , highlighting power control operation for scenarios (c) and (d). In these scenarios, the AT is power controlled from the RNC 310 . An SDU algorithm 515 running on the RNC 310 processes FCS information received from all RNs that are involved in the soft hand-off and generates the consolidated FCS. If a good frame is received from at least one RN, then consolidated FCS is considered good. Bad FCS indication is generated if bad frames are received from all RNs. The RLOLPC-RNC module 335 gets FCS information from the SDU 515 and determines adaptive PCT that satisfies the FER criterion (RL FER is a configurable parameter. See the description above about the soft handoff count parameter). This value is stored in the power control connection object 520 for the specific connection. A connection list scanner module 525 scans the linked list of active connections that are in soft handoff. Entries to this list are added/deleted when an AT moves in and out of soft handoff. The scan list is updated from an interaction with the RNC call control module 505 . Updates from the call control 505 are based on soft handoff count information. Upon firing of a power control timer 530 (e.g., period=4 RL frames), the connection list is scanned. The RN-IP address and channel record 2-tuple uniquely identifies each RN. For each soft handoff leg (RN) in that connection, a PCT multiplexer 535 updates a consolidated PCT message with a new PCT. The structure of the consolidated PCT message is given in FIG. 6( a ). Once all connections in the list are scanned, PCT messages are transmitted to all RNs. In one example, for load balancing amongst competing tasks on the RNSM 540 , the connection list scanner 525 scans only a subset of connections in the connection list. This scanning size can be a configurable parameter on the RNC 310 and in one example is set to 960. In one example, the signaling PCT messages are sent to the RN 315 over the IP backhaul 330 using proprietary ABIS signaling protocol. In this example, there is no acknowledgement provided by RN 315 to RNC 310 . PCT values are quasi real-time and hence acknowledgements/retransmissions are redundant if messages are lost or dropped on the backhaul 330 . For a received message at RN-BIO-SC 515 , the PCT message remapper 545 strips out the BSCConnectionId and sends the received message to the appropriate RLM card 435 . Contents of this message are illustrated in FIG. 6( b ). PCT demultiplexer 445 located on the RLM 435 populates the appropriate power control connection object 430 with PCT RNC . For each connection, the decision module 425 chooses an appropriate PCT depending on the soft handoff count value. In scenarios (c) and (d), the soft handoff count>1 and hence PCT RNC is chosen. This value is written into the modem receiver and serves as current input to RLILPC 405 .

The description describes examples for performing reverse link power control in a mobile network having a plurality of first modem devices that receive and transmit signals to wireless access terminals (ATs) and a second device in communication with the plurality of first devices. Execution is transitioned between a first and a second loop to control reverse link power of one of the ATs. The transition is based on a state of a connection. The first control loop executes at one of the first devices and the second loop executes at the second device.

TECHNICAL FIELD This invention relates to ring transmission systems and, more particularly, to bidirectional ring transmission systems. BACKGROUND OF THE INVENTION It has become increasingly important to maintain communications connectivity in the presence of transmission system failures. To this end, path-switched ring type transmission systems and, more recently, bidirectional line-switched ring type transmission systems have been proposed that heal communications circuits in the presence of equipment failures, fiber cuts and node failures. Bidirectional line-switched ring transmission systems have a capacity advantage over path-switched ring transmission systems for all communications traffic patterns except a so-called simple hubbed traffic pattern, where the path-switched and line-switched ring transmission systems have the same capacity. On the other hand, a path-switched ring transmission system provides circuit presence at every ring node on the ring transmission system for each communications circuit being transported on the ring. In a bidirectional line-switched ring transmission system, circuit presence at every ring node for communications circuits propagating on the ring can only be established by employing twice the bandwidth as that used for the same communications circuits in the path-switched ring transmission system. Additionally, in the bidirectional line-switched ring transmission system, all service bandwidth is ring-protection-switched when necessary, and it is not possible to leave any of the bandwidth unprotected by ring switching. SUMMARY OF THE INVENTION The problems related to inefficient universal communications circuit presence and of lack of bandwidth unprotected by ring switching in a bidirectional line-switched transmission system are overcome, in accordance with the principles of the invention, by selectively switching, in accordance with the same rules governing the set-up and take down procedures of full line-switching, only that portion of the bandwidth of the particular line which has been provisioned to be ring-switched. In accordance with the invention, the remaining bandwidth can be left unprotected or path-switched on a communications-circuit-by-communications-circuit basis, thereby, for the first time, line-switched ring functionality is combined with path-switched ring functionality in the same ring transmission system. Furthermore, in accordance with the invention, another degree of switching freedom is achieved in a four-optical-fiber bidirectional line-switched ring transmission system by selectively span-switching, but not ring-switching, specific bandwidth on the line. To this end, communications circuit provisioning information is provided in the ring nodes as to whether a particular communications circuit should be line switched or not and, if not, whether it should be path-switched, span-switched or not switched, i.e., left unprotected. Thus, a determination can be made, in accordance with the principles of the invention, on a communications-circuit-by-communications-circuit basis whether an individual communications circuit on the ring should be protection switched and, if so, the type of switching to be effected. BRIEF DESCRIPTION OF THE DRAWING In the drawing: FIG. 1 shows, in simplified block diagram form, a ring transmission system including the invention; FIG. 2 shows, in simplified block diagram form, details of a ring node including an embodiment of the invention; FIG. 3 shows, in simplified block diagram form, details of a squelcher used in the ring node of FIG. 2; FIG. 4 shows, in simplified block diagram form, details of an AIS insert unit employed in the squelcher of FIG. 3; FIG. 5 is an exemplary ring node ID table included in memory of the controller of FIG. 2; FIG. 6 is an exemplary communications circuit ID table also included in memory of the controller of FIG. 2 for ring node 104; FIG. 7 is another exemplary communications circuit ID table also included in memory of the controller of FIG. 2 for ring node 104; FIG. 8 is a flow chart illustrating the switching and possible squelching operation of the controller of FIG. 2; FIG. 9 illustrates the failure message transmission for a complete fiber failure in the bidirectional line-switched ring transmission system; and FIG. 10 illustrates the failure message transmission for a single ring node failure in the bidirectional line-switched ring transmission system. DETAILED DESCRIPTION FIG. 1 shows, in simplified form, a bidirectional ring transmission system, in this example bidirectional line-switched-ring transmission system 100, which for brevity and clarity of exposition is shown as including only ring nodes 101 through 104, each incorporating an embodiment of the invention. Ring nodes 101 through 104 are interconnected by transmission path 110 in a counter-clockwise direction and by transmission path 120 in a clockwise direction. In this example, transmission paths 110 and 120 are comprised of optical fibers and each could be comprised of a single optical fiber or two (2) optical fibers. That is, bidirectional line-switched ring transmission system 100 could be either a two (2) optical fiber or a four (4) optical fiber system. In a two (2) optical fiber system, each of the fibers in transmission paths 110 and 120 includes service bandwidth and protection bandwidth. In a four (4) optical fiber system, each of transmission paths 110 and 120 includes an optical fiber for service bandwidth and a separate optical fiber for protection bandwidth. Such bidirectional line-switched ring transmission systems are known. In this example, transmission of digital signals in the SONET digital signal format is assumed. However, it will be apparent that the invention is equally applicable to other digital signal formats, for example, the CCITT synchronous digital hierarchy (SDH) digital signal formats. In this example, it is assumed that an optical OC-N SONET digital signal format is being utilized for transmission over transmission paths 110 and 120. The SONET digital signal formats are described in a Technical Advisory entitled "Synchronous Optical Network (SONET) Transport Systems: Common Generic Criteria", TA-NWT-000253, Bell Communications Research, Issue 6, September 1990. It is noted that requests and acknowledgments for protection switch action are transmitted in an automatic protection switch (APS) channel in the SONET overhead accompanying the protection bandwidth on each of transmission paths 110 and 120. The APS channel, in the SONET format, comprises the K1 and K2 bytes in the SONET overhead of the protection bandwidth. The K1 byte indicates a request of a communications circuit for switch action. The first four (4) bits of the K1 byte indicate the switch request priority and the last four (4) bits indicate the ring node identification (ID). The K2 byte indicates an acknowledgment of the requested protection switch action. The first four (4) bits of the K2 byte indicate the ring node ID and the last 4 bits indicate the action taken. For purposes of this description, a "communications circuit" is considered to be a SONET STS-3 digital signal having its entry and exit points on the ring. Each of ring nodes 101 through 104 comprises an add-drop multiplexer (ADM). Such add-drop multiplexer arrangements are known. For generic requirements of a SONET based ADM see the Technical Reference entitled "SONET ADD-DROP Multiplex Equipment (SONET ADM) GENERIC CRITERIA", TR-TSY-000496, Issue 2, September 1989, Supplement 1, September 1991, Bell Communications Research. In this example, the ADM operates in a transmission sense to pass signals through the ring node, to add signals at the ring node, to drop signals at the ring node, to bridge signals during a protection switch and to loop-back-switch signals during a protection switch at the ring node. FIG. 2 shows, in simplified block diagram form, details of ring nodes 101 through 104, including an embodiment of the invention. In this example, a west(W)-to-east(E) digital signal transmission direction is assumed in the service bandwidth and the protection bandwidth on transmission path 110. It will be apparent that operation of the ring node and the ADM therein would be similar for an east(E)-to-west(W) digital signal transmission direction in the service bandwidth and the protection bandwidth on transmission path 120. Specifically, shown is transmission path 110 entering the ring node and supplying an OC-N SONET optical signal to receiver 201, where N could be, for example, 12 or 48. Receiver 201 includes an optical/electrical (O/E) interface 202 and a demultiplexer (DEMUX) 203, which yields at least one (1) STS-M SONET digital signal. Such O/E interfaces and demultiplexers are known. In this example, M is assumed to be three (3) and N is greater than M. In order to accomplish line-switching in a two optical fiber bidirectional line-switched ring transmission system, M must be a divisor of N/2. In accordance with the principles of the invention, however, M must be no greater than the tributary level which it is desired to path protection switch. The STS-M signal output from DEMUX 203 is supplied to squelcher (S) 204 which, under control of controller, 205 controllably squelches, i.e., blocks, particular incoming communications circuits by inserting an alarm indication signal (AIS), as described below. Details of squelcher (S) 204 are shown in FIGS. 3 and 4 and its operation is described below. Thereafter, the STS-M signal, squelched or otherwise, is supplied to monitor element 230 and to broadcast element 206. Monitor element 230 checks the passing communication circuit signal for conditions such as loss of signal (LOS) or for parameters such as a bit error rate (BER). Such monitor elements are known in the art. A broadcast element replicates the STS-M signal supplied to it and supplies the replicated signals as a plurality of individual outputs. Such broadcast elements are known. Broadcast element 206 generates three identical STS-M signals and supplies one STS-M signal to an input of 3:1 selector 207, a second STS-M signal to an input of 2:1 selector 208 and a third STS-M signal to an input of 3:1 selector 209. An STS-M signal output from 3:1 selector 207 is supplied to squelcher (S) 210, which is identical to squelcher (S) 204. Squelcher (S) 210 is employed, under control of controller 205, to squelch particular outgoing communications circuits. The STS-M signal output from squelcher (S) 210 is supplied to transmitter 211 and, therein, to multiplexer (MUX) 212. The output of MUX 212 is an electrical OC-N digital signal, which is interfaced to transmission path 110 via electrical/optical (E/O) interface 213. Such multiplexers (MUXs) and electrical/optical (E/O) interfaces are well known. Similarly, in the east(E)-to-west(W) direction an OC-N optical signal is supplied via transmission path 120 to receiver 214 and, therein, to optical/electrical (O/E) interface 215. In turn, demultiplexer (DEMUX) 216 yields a STS-M signal which is supplied via squelcher (S) 217 to monitor element 231 and then to broadcast element 218. Broadcast element 218 replicates the STS-M signal into a plurality of identical STS-M signals, in this example, three (3). One STS-M signal is supplied to an input of 3:1 selector 207, a second STS-M signal is supplied to an input of 2:1 selector 208 and a third STS-M signal is supplied to an input of 3:1 selector 209. An output from 3:1 selector 209 is supplied via squelcher (S) 219 to transmitter 220. In transmitter 220, multiplexer (MUX) 221 multiplexes the STS-M into an electrical OC-N and, then, electrical/optical (E/O) interface 222 supplies the optical OC-N signal to transmission path 120. Controller 205 operates to effect the provisioned line-switching and deterministic squelching of communications circuits, or path-switching, in accordance with the principles of the invention. Additionally, as indicated below, a restriction to span-switching of a particular communications circuit can also be realized in a four fiber bidirectional line-switched ring transmission system, in accordance with another aspect of the invention. Controller 205 communicates with receivers 201 and 214 and transmitters 211 and 220 via bus 223 and with interface 224 via bus 227. Specifically, controller 205 monitors the incoming digital signals to determine loss-of-signal, SONET format K bytes and the like. Additionally, controller 205 causes the insertion of appropriate K byte messages for protection switching purposes, examples of which are described below. To realize the desired deterministic squelching of the communications circuits, controller 205 is advantageously provisioned via bus 228 with the identities (IDs) of all the communications circuits passing through the ring node, as well as those communications circuits being added and/or dropped at the ring node and the identities of all the ring nodes in bidirectional line-switched ring 100. The squelching of communications circuits under control of controller 205 to effect the invention is described below. Controller 205 communicates with monitors 230 and 231 to compare the health of two copies of an incoming path-switched communications circuit, and then instructs selector 208 to pick the better of the two copies. Interface 224 is employed to interface to a particular duplex link 225 and could include any desired arrangement. For example, interface 224 could include a DS3 digital signal interface to a DSX, an STS-1E (electrical) SONET digital signal interfacing to a DSX, an optical extension interface to an OC-N SONET optical signal or the like. Such interface arrangements are known. Specifically, a signal (R) to be dropped at the ring node is supplied to interface 224 via 2:1 selector 208, under control of controller 205, from either broadcast element 206 or broadcast element 218. In turn, interface 224 supplies the appropriate signal to duplex link 225. A signal (T) to be added at the ring node is supplied from duplex link 225 to interface 224 where it is convened to the STS-M digital signal format, if necessary. The STS-M digital signal is then supplied to broadcast element 226 where it is replicated. The replicated STS-M digital signals are supplied by broadcast element 226, to an input of 3:1 selector 207 and an input of 3:1 selector 209. In this example, 3:1 selectors 207 and 209, under control of controller 205, select the signal being added for transmission in the service bandwidth or the protection bandwidth on either transmission path 110 or transmission path 120. It should be noted that, in this example, the normal transmission path for a digital signal being added at the ring node would be in the service bandwidth on transmission path 120, for example, towards the west (W). The following describes the procedure for those communications circuits which are to be line-switched, if there were to be a protection switch. The signal (T) being added from interface 224 would be bridged via broadcast element 226 and chosen by 3:1 selector 207, under control of controller 205, to the protection bandwidth on transmission path 110. Similarly, if there were to be a loop-back protection switch and the ring node was adjacent to the failure, the signal (R) to be dropped at the ring node would be received in the protection bandwidth on transmission path 120 and would be switched from broadcast element 218 via 2:1 selector 208 to interface 224. It is noted that "failure" or "ring node failure" as used herein is intended to include node equipment failure and so-called node isolation failure caused by optical fiber cuts, cable cuts or the like. Otherwise, the signal (R) to be dropped would be switched in a ring node adjacent the failure from the protection bandwidth on transmission path 120 to the service,bandwidth on transmission path 110 and received at the ring node in usual fashion. Then, the signal (R) being dropped from transmission path 110 is supplied via broadcast element 206 and 2:1 selector 208 to interface 224. As indicated above, controller 205 monitors the status of interface 224 and the digital signal supplied thereto via bus 227. Specifically, controller 205 monitors interface 224 for loss-of-signal, coding violations and the like, i.e., a signal failure condition. Under control of controller 205, as previously noted, digital signals may be passed through, added at, dropped at, bridged at or loop-back-switched at the ring node. A loop-back-switch of an STS-M digital signal incoming in the service bandwidth on transmission path 110 is effected by controller 205 causing 3:1 selector 209 to select the STS-M digital signal from broadcast element 206 and supplying it via squelcher (S) 219 to transmitter 220. In turn, transmitter 220 supplies an OC-N optical signal to the protection bandwidth on transmission path 120. It will be apparent that in the loop-back-switch operation, if the signal is incoming in a service bandwidth on transmission path 110, it will be loop-back-switched to the protection bandwidth on transmission path 120 and vice versa. If the signal is incoming in protection bandwidth on transmission path 110, it will be loop-back-switched to the service bandwidth on transmission path 120 and vice versa. A signal to be added at the ring node is supplied from interface 224, replicated via broadcast element 226 and selected either by 3:1 selector 207 or 3:1 selector 209, under control of controller 205, to be added on transmission path 110 or transmission path 120, respectively. A digital signal to be dropped at the ring node is selected by 2:1 selector 208, under control of controller 205, either from broadcast element 206 (transmission path 110) or broadcast element 218 (transmission path 120). The pass-through and loop-back-switch functions for a signal incoming on transmission path 120 is identical to that for an incoming signal on transmission path 110. Possible communications circuit misconnections are avoided in bidirectional line-switched ring 100 by deterministically squelching communications circuits to be line-switched that are terminated in a failed ring node in ring nodes adjacent to the failed ring nodes(s). The adjacent failed ring nodes can include a plurality of nodes including those that appear to be failed because of being isolated by other failed ring nodes or by fiber and/or cable cuts. To this end, each ring node in bidirectional line-switched ring transmission system 100 is typically equipped to effect the desired squelching via squelchers (S) 204, 210, 217 and 219, under control of controller 205. In this example, both incoming and outgoing communications circuits are squelched, however, it may only be necessary to squelch outgoing communications circuits. FIG. 3 shows, in simplified block diagram form, details of an exemplary squelcher (S) unit. Specifically, the STS-M digital signal is supplied to demultiplexer (DEMUX) 301 where it is demultiplexed into its constituent M STS-1 digital signals 302-1 through 302-M. The M STS-1 digital signals are supplied on a one-to-one basis to AIS insert units 303-1 through 303-M. AIS insert units 303-1 through 303-M, under control of controller 205, insert AIS in the STS-1 digital signals included in the communications circuits, i.e., STS-M digital signals, to be squelched. Details of AIS insert units 303 are shown in FIG. 4 and described below. Thereafter, the M STS-1 digital signals are multiplexed in multiplexer (MUX) 304 to yield the desired STS-M digital signal. The details of multiplex schemes for the STS-M digital signal are described in the technical advisory TA-NWT-000253, referenced above. FIG. 4 shows, in simplified block diagram form, details of AIS insert units 303. Specifically, shown is an STS-1 digital signal being supplied to AIS generator 401 and to one input of 2:1 selector 402. AIS generator 401 operates to insert AIS in the STS-1 digital signal. As indicated in the technical advisory TA-NWT-000253, the STS path AIS is an "all ones" (1's) signal in the STS-1 overhead bytes H1, H2 and H3 and in the bytes of the entire STS SPE (synchronous payload envelope). Selector 402 selects as an output, under control of controller 205, either the incoming STS-1 digital signal or the STS-1 digital signal with AIS inserted from AIS generator 401. FIG. 5 is a table including the identification (ID) of ring nodes 101 through 104. The ring node IDs are stored in a look-up table which is provisioned via 228 in memory of controller 205. As indicated above, the ring node IDs are 4 bit words and are included in the second 4 bits of the K1 bytes and the first 4 bits of the K2 bytes in the APS channel. FIG. 6 is illustrative of a table including the identification of all the active communications circuits in a ring node, in this example, ring node 104, for a counter-clockwise communication through nodes 101 through 104 (FIG. 1). The active communications circuits include those being added, being dropped or passing through ring node 104. The table including the IDs of the active communications circuits in the ring node are provisioned via input 228 in a look-up table in memory of controller 205. Shown in the table of FIG. 6 are (a) the STS-M communications circuit numbers (#) b through f; (b) an identification of the ring node which includes the communications circuit entry point, i.e., the A termination for the communications circuit; and (c) an identification of the ring node which includes the communications circuit exit point, i.e., the Z termination for the communications circuit. Thus, the communications circuit ID table of FIG. 6, shows that STS-M(b) enters ring 100 at ring node 104 and exits at ring node 102; STS-M(c) enters ring 100 at ring node 103 and exits at ring node 101; STS-M(d) enters ring 100 at ring node 102 and exits at ring node 101; STS-M(e) enters ring 100 at ring node 103 and exits at ring node 102; and STS-M(f) enters ring 100 at ring node 103 and exits at ring node 104. Although the ring nodes designated as A terminations are considered entry points and the ring nodes designated as Z terminations are considered exit points, it will be apparent that the individual communications circuits may be duplex circuits having both entry and exit points at each such node. It should be noted that heretofore all communications circuits would be line-switched, but now it is possible, in accordance with the principles of the invention, to line-switch a subset of the communications circuits and to path-switch another subset of the communications circuits, as desired. Thus, as shown in FIG. 6, STS-M(b), STS-M(c) and STS-M(d) are provisioned, in accordance with the invention, to be line-switched and STS-M(e) and STS-M(f) are provisioned, in accordance with the invention, to be path-switched. Also encompassed within the principles of the invention is the capability of leaving a subset of the communications circuits unprotected. And in a four optical fiber bidirectional line-switch ring transmission system, it is now also possible to specify whether span-switching of communications circuits will be employed or not. These concepts are illustrated in FIG. 7 which, is illustrative of another exemplary table including the identification of all the active communications circuits in ring node 104, for counter-clockwise communication through ring nodes 101 through 104. Specifically, FIG. 7 illustrates how unprotected or span-switched communications circuits are provisioned via input 228 in a look-up table in memory of controller 205 (FIG. 2) in a four fiber ring transmission system. Communications circuits STS-M(b) through STS-M(f) are provisioned as shown in FIG. 6 and described above. Communications circuit STS-M(g) is span-switched only, and communications circuit STS-M(h) is unprotected. FIG. 8 is a flow chart illustrating the operation of controller 205 in controlling the operation of the ring nodes in order to effect the provisioned switching (and the deterministic squelching, if necessary) of communications circuits in the presence of a failure, in accordance with the invention. Specifically, the process is entered via step 801. Then, operational block 802 causes the K bytes of an incoming OC-N signal to be observed and processes the ring node IDs therein. Then, conditional branch point 803 tests to determine if the processed ring node IDs indicate that one or more ring nodes have failed. Again, a ring node failure is defined as to include node equipment failure and so-called node isolation failure caused by fiber cuts and the like. Specific examples of failure conditions are discussed below. If the processed ring node IDs indicate no ring node failure, the failure is other than a ring node failure and control is passed to operational block 804. Similarly, if step 803 indicates a single ring node failure, the failed ring node ID is already known and control is also passed directly to step 804. If the processed ring node IDs indicate a multiple ring node failure, operational block 805 causes the failed ring node IDs to be obtained from the ring node ID look-up table in memory (FIG. 5). Then, as in the other two instances, control is passed to operational block 804. Operational block 804 causes the identity (ID) of the affected communications circuits to be obtained whether or not any particular such communications circuit is to be line-switched (or possibly squelched), and if not line-switched, whether or not it is to be path-switched, and if not path-switched, whether or not it is to be span-switched from the communications circuit ID look-up table (FIG. 7) in memory of controller 205 (FIG. 2). Once the affected communications circuits are identified, conditional branch points 806, 810 and 812 separate the control process depending upon whether the affected individual communications circuit should be line-switched or not, should be path-switched or not, or should span-switched or not. It should be noted that if the communications circuit is not line-switched, path-switched or span-switched, it is left unprotected, in accordance with an aspect of the invention. It will be apparent to those skilled in the art that the individual affected communications circuits can be arranged into subgroups of communications circuits to be either line-switched, path-switched, span-switched only or not switched, i.e., left unprotected. If the communications circuit is to be line-switched, as determined in step 806, operational block 807 causes, if necessary, the appropriate ones of squelchers (S) 204, 210, 217 and 219 (FIG. 2), in this example, to squelch those identified communications circuits in the ring node. As indicated above, all line-switched communications circuits active in this ring node that are terminated in a failed ring node are squelched. Operational block 808 thereupon causes the line-switched communications circuits not terminated in the failed ring node(s) to be bridged and switched to "heal" the ring. Thereafter, the process is ended in step 809. If a communications circuit is to be path-switched, as determined in steps 806 and 810, operational block 811 compares, via monitors 230 and 231 (FIG. 2), the relative health of the two copies of the particular communications circuit, and engages path-switching in selector 208 (FIG. 2), if appropriate. Thereafter, the process is ended in step 809. If the affected communications circuit is not to be either line-switched or path-switched as determined in steps 806 and 810, conditional branch point 812 tests to determine whether or not the communications circuit is to be span-switched. If the affected communications circuit is to be span-switched, operational block 814 effects the span-switching as appropriate. Thereafter, the process is ended in step 809. Again, if the affected communications circuit is to be left unprotected as determined in steps 806, 810 and 812 the process is ended in step 809. FIG. 9 illustrates the failure message transmission in the automatic protection switch (APS) channel K1 bytes for a transmission path failure in bidirectional line-switched ring 100. In this example, the failure is shown as being in transmission paths 110 and 120 between ring nodes 101 and 102. Ring node 101 detects loss-of-signal from ring node 102 on incoming transmission path 120. Loss-of-signal as used herein is intended to include other indicators such as loss-of-frame, high bit error rate or the like. Then, ring node 101 transmits a line-switch request message identifying the signal from ring node 102 as having failed. Specifically, the line-switch request messages are transmitted in the APS channel K1 byte on transmission path 120 away from the failure toward ring node 104. This line-switch request message is designated SF L /102. Ring node 101 also transmits a span-switch request message in the APS channel K1 byte on transmission path 110 towards the failure. The span-switch request message is designated SF L /102. It should be noted, however, that a span-switch request is only issued and can only be realized in a four (4) fiber bidirectional line-switched ring transmission system 100. Ring node 104 recognizes that the line-switch request message SF L /102 in the incoming APS channel K1 byte does not identify an adjacent ring node and passes the line-switch request message on to ring node 103. Similarly, ring node 103 passes the line-switch request message on to ring node 102. In turn, ring node 102 recognizes its own ID in the SF L /102 line-switch request message, which indicates to ring node 102 that a ring node has not failed. Since there was no ring node failure, there is no need to squelch any of the communication circuits active in ring node 102. Ring node 102 does, however, effect a loop-back-switch of line-switched communications circuits received at the ring node in the service bandwidth on transmission path 120 to the protection bandwidth on transmission path 110 for communications circuits intended for other ring nodes in ring 100. Ring node 102 also effects a ring loop-back-switch of line-switched communications circuits entering the node that were intended to be transmitted in the service bandwidth on transmission path 120 to the protection bandwidth on transmission path 110. Any communication circuits received at ring node 102 that are intended to be dropped from either the service bandwidth or protection bandwidth on transmission path 120, are supplied to interface 224 (FIG. under control of controller 205, as described above. Any communications circuits to be path-switched are path-switched at their termination ring nodes if the current path selections are affected by the failure. Similarly, ring node 102 detects a loss-of-signal from ring node 101 on transmission path 110 because of the failure in transmission paths 110 and 120 between ring nodes 101 and 102. Then, ring node 102 transmits a line-switch request message identifying the signal from ring node 101 as having failed in the APS channel K1 byte on transmission path 110. This line-switch request message is designated SF L /101. Ring node 102 also transmits a span-switch request message in the APS channel K1 byte on transmission path 120 towards the failure. The span-switch request message is designated SF S /101. Again, it should be noted that a span-switch request is only issued and can only be realized in a four (4) fiber bidirectional line-switched ring transmission system 100. Ring node 103 recognizes that the line-switch request SF L /101 in the incoming APS channel K1 byte does not identify an adjacent ring node and passes the line-switch request message on to ring node 104. Similarly, ring node 104 passes the line-switch request message on to ring node 101. In turn, ring node 101 recognizes its own ID in the SF L /101 line-switch request message, which indicates to ring node 101 that a ring node has not failed. Since there was no ring node failure, there is no need to squelch any of the communication circuits active in ring node 101. Ring node 101 does, however, effect a loop-back-switch of line-switched communications circuits received at the ring node in the service bandwidth on transmission path 110 to the protection bandwidth on transmission path 120 for communications circuits intended for other ring nodes in ring 100. Ring node 101 effects a ring loop-back-switch of line-switched communications circuits entering the node that were intended to be transmitted in the service bandwidth on transmission path 110 to the protection bandwidth on transmission path 120. Any communications circuits received at ring node 101 that are intended to be dropped from either the service bandwidth or protection bandwidth on transmission path 110, are supplied as described above, under control of controller 205 to interface 224 (FIG. 2). Any communications circuits to be path-switched are path-switched at their termination ring nodes if the current path selections are affected by the failure. FIG. 10 illustrates the failure message transmission in the automatic protection switch (APS) channel via the K1 byte for a single ring node failure in bidirectional line-switched ring 100. In this example, the failure is shown as being in ring node 101. Ring node 102 detects a loss-of-signal from ring node 101 on transmission path 110 because of the failure of node 101. Then, ring node 102 transmits a line-switch request message identifying the signal from ring node 101 as having failed in the APS channel K1 byte on transmission path 110 away from the failure toward ring node 103. This line-switch request signal is designated SF L /101. Ring node 102 also transmits a span-switch request message from the APS channel K1 byte on transmission paths 120 towards failed node 101. The span-switch request message is designated SF S /101. As indicated above, a span-switch is only issued and can only be realized in a four (4) fiber bidirectional line-switched ring transmission system 100. Ring node 103 recognizes that the line-switch request message SF L /101 in the incoming APS channel K1 byte does not identify an adjacent ring node and, therefore, passes the line-switch request message on to ring node 104. Ring node 104 recognizes that the line-switch request message SF L /101 includes the ID of the adjacent failed ring node 101. A single node failure is indicated because ring node 104 has also detected loss-of-signal from ring node 101 on transmission path 120. Consequently, ring node 104, under control of controller 205 (FIG. 2), causes all active line-switched communications circuits in ring node 104 intended for ring node 101 to be squelched. The squelching is realized as described above in conjunction with FIG. 2 and the process of FIG. 8. Specifically, referring to the communications circuit ID table for ring node 104 in FIG. 6 or FIG. 7, it is seen that communications circuits STS-M (c) and STS-M (d) are to be squelched. Line-switched communications circuit STS-M (b) is identified as not being terminated in ring node 101 and, therefore, no squelching is effected for it. Thus, communications circuit STS-M(b) is ring loop-back-switched in ring node 104 to the protection bandwidth on transmission path 120 and supplied thereon to ring node 102 where it is appropriately dropped, in the manner described above. Path-switched communications circuits STS-M(e) and STS-M(f) are path-switched at their terminations if the current path selections are affected by the failure of ring node 101. The mechanics and process for effecting path-switching are well known to those skilled in the art. Communications circuit STS-M(f) is not affected by the failure of node 101 and communications between ring nodes 103 and 104 are realized in normal fashion. As indicated above, ring node 104 detects a loss-of-signal on transmission path 120 from failed ring node 101. Then, ring node 104 transmits a line-switch request message identifying the signal from ring node 101 as having failed in the APS channel K1 byte on transmission path 120 away from the failure toward ring node 103. Again, this line-switch request message is designated SF L /101. Ring node 104 also transmits a span-switch request message in the APS channel K1 byte on transmission path 110 towards the failed node 101. The span-switch request message is designated SF S /101. As indicated above, a span-switch can only be realized in a four (4) fiber bidirectional line-switched ring transmission system 100. Ring node 103 recognizes that the line-switch request SF L /101 incoming in the APS channel on transmission path 120 does not identify an adjacent failed node and passes the line-switch request message on to ring node 102. Ring node 102 recognizes that the line-switch request message includes the ID of an adjacent failed ring node, namely, ring node 101. A single ring node failure is indicated because ring node 102 has detected loss-of-signal from ring node 101 and has received a line-switch request message identifying node 101 as having failed. Consequently, ring node 102 will squelch all active line-switched communications circuits intended for ring node 101. Line-switched communications circuits terminated in others of the ring nodes in ring 100 are appropriately bridged and loop-back-switched as required to "heal" the ring 100. As indicated above, communications circuits to be path-switched are path-switched at their termination ring nodes if the current path selections are affected by the failure. The above-described arrangements are, of course, merely illustrative of the application of the principles of the invention. Other arrangements may be devised by those skilled in the art without departing from the spirit or scope of the invention. For example, it will be apparent to those skilled in the art that a particular communications circuit, i.e., tributary, on the ring could be segmented into portions which can be line-switched, path-switched, span-switched or not switched, i.e., left unprotected with appropriate priorities assigned to the portions and the type of switching, as desired. It will also be apparent that the bidirectional ring transmission system can support only path-switching of some communications circuits while leaving others unprotected. Additionally, it will be apparent that a four (4) fiber bidirectional ring transmission system can support path-switching of some of the communications circuits and span-switching of others. Finally, the four (4) fiber bidirectional ring transmission system can also support span-switching of some of the communications circuits and leaving others unprotected.

Selective tributary switching is realized in a bidirectional transmission system by selectively switching, in accordance with the same rules governing the set-up and take down procedures of full line-switching, only that portion of the bandwidth of the particular line which has been provisioned to be line-switched. The remaining bandwidth can be left unprotected or, by for the first time combining line-switched ting functionality with path-switched ring functionality in the same ring transmission system, some remaining bandwidth can be path-switched. Furthermore, another degree of switching freedom is achieved in a four optical fiber bidirectional ring transmission system by selectively span-switching, but not ring-switching, specific bandwidth on the line. To this end, communications circuit provisioning information is provided in the ring nodes as to whether a particular communications circuit should be line-switched or not and, if not, whether it should be span-switched, path-switched or left unprotected.

[0001] This application is a continuation of application Ser. No. 11/011,008, filed on Dec. 13, 2004, which claims the benefit of Korean Patent Application No. 10-2003-0091341, filed on Dec. 15, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of controlling a digital photographing apparatus (e.g., a digital camera), and more particularly, to a method of controlling a digital photographing apparatus that receives an image having a resolution with a first pixel number and displays a display image on a displaying unit having a resolution with a second pixel number. [0004] The method of controlling the digital photographing apparatus of the present invention can be adopted in any digital photographing apparatus that captures and stores images in addition to digital cameras. In the present application, a digital camera is used as a typical example in which the present invention can be adopted. [0005] 2. Description of the Related Art [0006] FIG. 1 is a front perspective view of a conventional digital camera 1 . Referring to FIG. 1 , the digital camera 1 includes on its front surface, a microphone MIC, a self-timer lamp 11 , a flash 12 , a shutter button 13 , a mode dial 14 , a function-select button 15 , a photograph information display unit 16 , a view finder 17 a , a function-block button 18 , a flash-light amount sensor (FS) 19 , a lens unit 20 , and an external interface unit 21 . [0007] When in a self-timer mode, the self-timer lamp 11 operates when the shutter button 13 is pressed until a shutter (not shown) operates. The mode dial 14 is used to select one of various operating modes, for example, a still image photographing mode, a night scene photographing mode, a moving picture photographing mode, a reproducing mode, a computer connecting mode, and a system setting mode. The function-select button 15 is used to select one of the operating modes, for example, a still image photographing mode, a night scene photographing mode, a moving picture photographing mode, or a reproducing mode. The photograph information displaying unit 16 displays various information regarding each function related to photographing. The function-block button 18 is used to select one of the functions displayed on the photograph information display unit 16 . [0008] FIG. 2 is a rear view of the digital camera 1 of FIG. 1 . Referring to FIG. 2 , a speaker SP, a power button 31 , a monitor button 32 , an automatic focus lamp 33 , a view finder 17 b , a flash standby lamp 34 , a color liquid crystal display (LCD) panel 35 , a confirm/delete button 36 , an enter/play button 37 , a menu button 38 , a wide-angle zoom button 39 w , a telephoto zoom button 39 t , an up-movement button 40 up , a right-movement button 40 ri , a down-movement button 40 do , and a left-movement button 40 le are included on the back of the digital camera 1 . [0009] The monitor button 32 is used to control the operation of the color LCD panel 35 . For example, if the user presses the monitor button 32 a first time, an image of a subject and photographing information is displayed on the color LCD panel 35 ; when the monitor button 32 is pressed a second time, only the image of the subject is displayed on the color LCD panel 35 ; and when the monitor button 32 is pressed a third time, power supplied to the color LCD panel 35 is blocked. The automatic focus lamp 33 operates when an automatic focusing operation is completed. The flash standby lamp 34 operates when the flash 12 (see FIG. 1 ) is on standby. The confirm/delete button 36 is used as a confirm or delete button in the process in which a user sets one of the modes. The enter/play button 37 is used to input data or perform various functions such as stop or play in the reproducing mode. The menu button 38 is used to display a menu of a mode selected from the mode dial 14 . The up-movement button 40 up , the right-movement button 40 ri , the down-movement button 40 do , and the left-movement button 40 le are used in the process in which a user selects one of the modes. [0010] FIG. 3 is a view illustrating a structure of a surface of the digital camera 1 of FIG. 1 on which light is incident. FIG. 4 is a block diagram of the digital camera 1 of FIG. 1 . [0011] An optical system OPS including the lens unit 20 and a filter unit 41 optically processes light reflected from a subject. The lens unit 20 of the optical system OPS includes a zoom lens ZL, a focus lens FL, and a compensation lens CL. [0012] If a user presses the wide-angle zoom button 39 w (see FIG. 2 ) or the telephoto zoom button 39 t (see FIG. 2 ) included in a user inputting unit INP, a signal corresponding to the wide-angle zoom button 39 w or the telephoto zoom button 39 t is input to a micro-controller 512 . Accordingly, as the micro-controller 512 controls a lens driving unit 510 , a zoom motor M Z operates, thereby moving the zoom lens ZL. That is, if the wide-angle zoom button 39 w is pressed, the focal length of the zoom lens ZL is shortened, and thus increases a viewing angle. On the other hand, if the telephoto zoom button 39 t is pressed, the focal length of the zoom lens ZL is lengthened, and thus decreases a viewing angle. According to the above-mentioned characteristics, the micro-controller 512 can calculate a viewing angle based on the location of the zoom lens ZL from design data of the optical system OPS. Since the location of the focus lens FL is altered while the location of the zoom lens ZL is fixed, the viewing angle is hardly affected by the location of the focus lens FL. [0013] When the focus on a subject is automatically or manually fixed, the current location of the focus lens FL changes with respect to a distance Dc to a subject. Since the location of the focus lens FL is changed when the location of the zoom lens ZL is fixed, the distance Dc to the subject is affected by the location of the zoom lens ZL. In the automatic focusing mode, the micro-controller 512 controls the lens driving unit 510 , thereby driving a focus motor M F . Accordingly, the focus lens FL moves from the very front to the very back. In this process, a number of steps of the location of the focus lens FL (e.g., a number of location steps of the focus motor M F ) are set at which an amount of high frequency in an image signal is increased the most. [0014] The compensation lens CL is not separately operated since it acts to compensate for the overall refractive index. [0015] A motor M A drives an aperture (not shown). A rotation angle of the aperture driving motor M A depends on whether the digital camera 1 is in a specified area exposure mode or in another mode. In the specified exposure mode, when a part of a subject region desired by a user coincides with a specified detected region displayed on the color LCD panel 35 of the digital camera 1 , a light amount of the digital camera 1 is set to a mean brightness value of the specified detected region. [0016] An optical low pass filter (OLPF) included in the filter unit 41 of the optical system OPS removes optical noise with a high frequency. An infrared cut filter (IRF) included in the filter unit 41 blocks infrared components of incident light. [0017] A photoelectric converter OEC of a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) (not shown) converts light from the optical system OPS into an electrical analog signal. Here, a digital signal processor (DSP) 507 controls a timing circuit 502 and controls the operation of the photoelectric converter OEC and a correlation double sampler and analog-to-digital converter (CDS-ADC) device 501 . The CDS-ADC device 501 , which is an ADC, processes the analog signal output from the photoelectric converter OEC, and converts it into a digital signal after removing high frequency noise from the analog signal and altering the bandwidth of the analog signal. The DSP 507 processes the digital signal from the CDS-ADC device 501 , and generates a digital image signal divided into a chrominance signal and a luminance signal. [0018] A light emitting unit LAMP that is operated by the micro-controller 512 includes the self-timer lamp 11 , the automatic focus lamp 33 (see FIG. 2 ), and the flash standby lamp 34 (see FIG. 2 ). The user inputting unit INP includes the shutter button 13 (see FIG. 1 ), the mode dial 14 (see FIG. 1 ), the function-select button 15 (see FIG. 1 ), the function-block button 18 (see FIG. 1 ), the monitor button 32 (see FIG. 2 ), the confirm/delete button 36 (see FIG. 2 ), the enter/play button 37 (see FIG. 2 ), the menu button 38 (see FIG. 2 ), the wide-angle zoom button 39 w (see FIG. 2 ), the telephoto zoom button 39 t , the up-movement button 40 up (see FIG. 2 ), the right-movement button 40 ri (see FIG. 2 ), the down-movement button 40 do (see FIG. 2 ), and the left-movement button 40 le (see FIG. 2 ). [0019] The digital image signal output from the DSP 507 is temporarily stored in a dynamic random access memory (DRAM) 504 . Algorithms needed for the operation of the DSP 507 and for setting data are stored in an electrically erasable and programmable read-only memory (EEPROM) 505 . A memory card is inserted into a memory card interface (MCI) 506 . [0020] The digital image signal output from the DSP 507 is input to an LCD driving unit 514 . As a result, an image is displayed on the color LCD panel 35 . [0021] The digital image signal output from the DSP 507 can be transmitted in a series communication via a universal serial bus (USB) connector 21 a or an RS232C interface 508 and its connector 21 b , or can be transmitted as a video signal via a video filter 509 and a video outputting unit 21 c. [0022] An audio processor 513 outputs an audio signal from the microphone MIC to the DSP 507 or the speaker SP, and outputs an audio signal from the DSP 507 to the speaker SP. [0023] The micro-controller 512 controls the operation of a flash controller 511 according to a signal output from the FS 19 , and thus operates the flash 12 . [0024] FIG. 5 is a flowchart illustrating a method of controlling photographing of the micro-controller 512 illustrated in FIG. 4 . [0025] Referring to FIGS. 1 through 5 , the shutter button 13 included in the user inputting unit INP has a two-step structure. That is, if a user presses the shutter button 13 to a first step after the user operates the wide-angle zoom button 39 w or the telephoto zoom button 39 t , a first signal S 1 output from the shutter button 13 is activated, and if the shutter release button 13 is pressed to a second step, a second signal S 2 output from the shutter button 13 is activated. Therefore, the algorithm for controlling photographing illustrated in FIG. 5 starts when the shutter release button 13 is pressed up to the first step (Operation 101 ). Here, the current location of the zoom lens ZL is already set. [0026] Remaining storage space of the memory card is detected (Operation 102 ), and it is determined whether the storage space is sufficient to record a digital image (Operation 103 ). If there is not enough storage space, a message indicating a lack of storage space in the memory card is displayed (Operation 104 ). If there is enough storage space, the following operations are performed. [0027] Automatic white balance (AWB) is performed, and parameters related to the AWB process are set (Operation 105 ). Then, automatic exposure (AE) is performed in which a brightness of incident light is calculated, and the aperture driving motor M A is operated according to the calculated brightness amount (Operation 106 ). Then, automatic focusing is performed, and the location of the focus lens FL is set (Operation 107 ). [0028] Then, it is determined whether a first signal S 1 , which is a signal generated when the shutter button 13 is at a first step, is activated (Operation 108 ). If the first signal S 1 is inactivated, the user has no intention of photographing, and thus, a perform-program is terminated. If the first signal S 1 is activated, the following operations are performed. [0029] First, it is determined whether the second signal S 2 is activated (Operation 109 ). If the second signal S 2 is not activated, the user has not pressed the shutter button 13 to the second step for photographing, and thus the method moves to operation 106 . [0030] If the second signal S 2 is activated, a photographing operation is performed since the user has pressed the shutter button 13 to the second step for photographing. That is, the micro-controller 512 operates the DSP 507 , and the timing circuit 502 operates the photoelectric converter OEC and the CDS-ADS 501 . Then, image data is compressed (Operation 111 ), and a compressed image file is generated (Operation 112 ). After the generated image file is stored in the memory card via the MCI 506 from the DSP 507 (Operation 113 ), the method is completed. [0031] For reference, Japanese Patent Publication No. hei 11-196301, titled “Electronic Camera Device,” discloses an electronic camera device in which the state of an image, for example, a focusing or a shaking of the image at the moment of photographing, can be easily checked. [0032] FIGS. 6A , 6 B, 6 B′, and 6 C are views illustrating a conventional method of controlling a digital photographing apparatus to enlarge an image to check a focus of the image. [0033] Referring to FIGS. 6A , 6 B, 6 B′, and 6 C, in the conventional method of controlling the digital photographing apparatus, a predetermined region of an image displayed on an image displaying device 35 is set as a focus zone before photographing the image. After displaying an enlarged focus zone, a user focuses the image or presses a shutter switch to perform photographing. [0034] To do so, first, a focus frame 61 for checking the focus of the image is displayed inside a monitor image 60 of the subject, which is displayed on the image displaying device 35 , in a recording mode ( FIG. 6A ). Then, a portion of the image inside the focus frame 61 is automatically or manually at a command of the user enlarged, and displayed on the entire screen 62 or on a portion 63 of the screen (FIGS. 6 B and 6 B′). Then, the user checks whether the image is in focus by looking at the enlarged image, changes the focus if necessary, and performs photographing, and thus a photographed image 64 is displayed ( FIG. 6C ). [0035] Image sensors used in digital photographing apparatuses have an increasing number of pixels due to advancements in technology, and the size of an LCD display window, which is an image displaying device, is becoming smaller due to the miniaturization of digital photographing apparatuses. Therefore, there is a large difference between the resolutions of the image sensor and the LCD display window, which is the image displaying device. [0036] However, in the conventional method of controlling the digital photographing apparatus, the focus region is simply enlarged and displayed and resolutions of an image sensor and the image displaying device are not considered. Thus, it is difficult to achieve a good effect in the situation in which there is a large difference between the resolutions of the image sensor and the LCD display window as the image displaying device. SUMMARY OF THE INVENTION [0037] The present invention provides a method of controlling a digital photographing apparatus that can check the quality of a photographed image by enlarging a portion of the photographed image and displaying it on an image displaying device after photographing considering the difference between the resolution of an image sensor and the resolution of the image displaying device. [0038] According to an aspect of the present invention, there is provided a method of controlling a digital photographing apparatus in which a portion of an input image is enlarged and displayed as a display image on an image displaying unit so that a user may determine the clarity of the input image, the digital photographing apparatus receiving the input image having a resolution of a first pixel number and displaying the display image on the image displaying unit having a resolution of a second pixel number. The method includes: receiving the input image; setting an enlarged display region that is to be enlarged from the input image, dividing the enlarged display region into at least two display images, and continually displaying the display images on the image display unit. [0039] According to another aspect of the present invention, there is provided a method of controlling a digital photographing apparatus in which a portion of an input image is enlarged and displayed as a display image on an image displaying unit so that a user may determine the clarity of the input image, the digital photographing apparatus receiving the input image having a resolution of a first pixel number and displaying the display image on the image displaying unit having a resolution of a second pixel number. The method includes: receiving the input image; determining whether to enlarge the input image; setting a portion of the input image that is to be enlarged as an enlarged display region having a resolution of a third pixel number; calculating a number of display frames that are to be displayed on the image displaying unit by dividing the third pixel number by the second pixel number and rounding the result to an integer, and dividing the enlarged display region into the display images according to the number of the display frames; and displaying the display images on the image displaying unit. BRIEF DESCRIPTION OF THE DRAWINGS [0040] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: [0041] FIG. 1 is a front perspective view of a conventional digital camera; [0042] FIG. 2 is a rear view of the digital camera of FIG. 1 ; [0043] FIG. 3 is a view illustrating a structure of a surface of the digital camera of FIG. 1 on which light is incident; [0044] FIG. 4 is a block diagram of the digital camera of FIG. 1 ; [0045] FIG. 5 is a flowchart illustrating a method of controlling photographing of a micro-controller illustrated in FIG. 4 ; [0046] FIGS. 6A , 6 B, 6 B′, and 6 C are views illustrating a conventional method of controlling a digital photographing apparatus to enlarge a screen to check a focus of an image; [0047] FIG. 7 is a flowchart illustrating a method of controlling a digital photographing apparatus according to an embodiment of the present invention; [0048] FIG. 8 is a flowchart illustrating a method of displaying an enlarged image in the method of controlling the digital camera illustrated in FIG. 7 ; [0049] FIG. 9 is a view schematically illustrating the displaying of the enlarged image of FIG. 8 ; [0050] FIG. 10 is a view illustrating a setting of an enlarged display region in the displaying of the enlarged image described in FIG. 8 [0051] FIG. 11 is a view illustrating dividing of the enlarged display region into display images in the displaying of the enlarged image described in FIG. 8 ; and [0052] FIGS. 12A through 12D are views illustrating the displaying of the respective divided display images in FIG. 11 in an automatic slide show. DETAILED DESCRIPTION OF THE INVENTION [0053] The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The description of a digital photographing apparatus with reference to FIGS. 1 through 5 also applies to all digital photographing apparatuses in embodiments of the present invention. [0054] FIG. 7 is a flowchart illustrating a method 200 of controlling a digital photographing apparatus according to an embodiment of the present invention. [0055] Referring to FIG. 7 , in the method 200 , the digital photographing apparatus receives an input image having a first resolution and displays a display image on an image displaying unit having a second resolution. A portion of the input image is enlarged and displayed as the display image on the image displaying unit so that a user may determine the clarity of the input image. [0056] To do this, the digital photographing apparatus receives an input image (S 201 ). Then, a portion of the input image that is to be enlarged is set as an enlarged display region, the enlarged display region is divided into at least two display images, and the display images are continually displayed on an image displaying unit (S 203 ). The method may further include an operation of determining whether to enlarge the input image (S 202 ). [0057] In the present embodiment, the input image is input from the outside by photographing in operation S 201 . The input image may be input via an image sensor (a charge-coupled device (CCD)) as in a conventional digital photographing apparatus, and the image sensor has a first resolution. [0058] Although the input image is input from the outside by photographing in operation S 201 in the present embodiment, an input image may be obtained from the outside from an external device, and the obtained image may be input as image data via a data input/output unit in operation S 201 . In this case, in order to apply the method 200 of controlling the digital photographing apparatus according to the present invention, the input image data has the first resolution. [0059] In addition, the image data may be stored in a predetermined storage medium or a pre-photographed image may be stored as image data, and the stored input image may be checked by displaying the input image on the image displaying unit through the manipulation of the user. Operation S 203 may be performed by the manipulation of the user that makes the input image to be displayed on the image displaying unit. [0060] When desiring to display the photographed input image or the input image stored in the storage on the image displaying unit in advance, whether to display the enlarged input image or not may be set as a default. [0061] In operation S 202 , when displaying the input image on the image displaying unit using a setting, whether to enlarge and display the image can be determined. In this case, when not enlarging and displaying the input image according to the determination result of S 202 , the input image having the first resolution is converted into an image having a second resolution and displayed on the image displaying unit in S 204 . [0062] Since an image sensor used in a digital photographing apparatus usually has a higher number of pixels due to the advancement in technology, and the size of a liquid crystal display (LCD) display window, which is an image displaying device, is becoming more limited due to the miniaturizing of the digital photographing apparatus. Therefore, the first pixel number is higher than the second pixel number in many cases, and thus an input image with a high resolution is not properly displayed on the image displaying unit that has a lower resolution than the input image. Therefore, there is a limit in properly recognizing the clarity of the input image only with the image displayed on the image displaying unit. [0063] The image displaying unit maybe a display device such as an LCD or an organic electro luminescent may be used. In the present embodiment, an LCD panel is used. [0064] In operation S 203 , when enlarging and displaying the input image according to the determination result from operation S 202 , a portion of the input image that is to be enlarged is set as the enlarged display region. The enlarged display region is divided into at least two display images, and is continually displayed on the image displaying unit. The displaying of the enlarged input image in operation S 203 will be described in more detail with reference to FIG. 8 . In this case, each of the display images may be automatically displayed continually using an automatic slide show, as illustrated in FIG. 8 . [0065] In operation S 203 , one of the divided display images is displayed on the image displaying unit, and each of the display images selected by an input from the outside, for example, by the user, may be manually displayed. [0066] When enlarging a portion of the input image and displaying it on the image displaying unit in operation S 203 , an entire input image may be reduced and displayed on a portion of the image displaying unit on which the display image is displayed. Here, the input image may be surrounded by, for example, a quadrangular line so that it is distinguishable from the display image. The reducing of the entire input image and displaying it on the portion of the image displaying unit is as illustrated in FIGS. 9 and 12 . [0067] The displaying of the entire input image on the portion of the image displaying unit is used to indicate which portion of the entire input image is currently displayed as the display image on the image displaying unit. [0068] The enlarged display region of the input image is divided into at least two display images and displayed in operation S 203 so that the user may determine the clarity of the input image from the display image displayed on the image displaying unit. Here, the clarity of the image may be affected by how much the focus, a white balance, an amount of exposure, the shaking of the hands etc., were controlled. If the clarity of the image is reduced, the quality of the image becomes poorer. [0069] That is, when reproducing the photographed image on the image displaying unit and checking the photographed image in the present embodiment, the image is enlarged and reproduced in consideration of the resolution of the input image and the resolution of the image displaying unit, and thus making it easier for the user to determine the clarity of the input image. An image photographed when it is difficult to focus the image (e.g., when the hand shakes, the surrounding is dark, a manual focus is set, or a near subject is photographed) may be blurred. Even when the image appears to be well focused on the image displaying unit of the digital photographing apparatus, the clarity of the image may still be poor when displaying the image on an external displaying device having a much higher resolution than the image displaying unit. [0070] In this case, a specific region (i.e., a focus zone) of the input image is enlarged and displayed to easily check the clarity of the input image, or the user may easily check the clarity of the input image using a digital zoom. [0071] In addition, the method 200 of controlling the digital photographing apparatus may further include deleting the input image when the clarity of the display image is not satisfactory according to the determination of the user. That is, first, the specific region of the input image is enlarged and displayed so that the user may check the clarity of the input image. Then, when the input image does not have a satisfactory clarity according to the determination of the user and the user desires to delete the currently checked input image, the input image may be deleted. [0072] Furthermore, after checking the clarity of the input image using the method 200 of controlling the digital photographing apparatus, a process of deleting the input image if the clarity of the display image is lower than a standard clarity may be performed automatically by the digital photographing apparatus. The clarity can be determined based on a focus, a white balance, an amount of exposure etc., and a satisfactory clarity may be pre-set as the standard clarity. [0073] To do so, first, it is determined whether the input image is to be deleted by the selection of the user (S 205 ). In the case it is set for the user to delete the input image, the input image is deleted (S 206 ). The input image that does not have a desired quality is deleted so that a new input image may be obtained. [0074] FIG. 8 is a flowchart illustrating the displaying the enlarged image (S 203 ) in the method 200 of controlling the digital camera of FIG. 7 . FIG. 9 is a view schematically illustrating the displaying of the enlarged image (S 203 ) of FIG. 8 . [0075] Referring to FIGS. 7 through 9 , in the method 200 , the digital photographing apparatus receives the input signal having the first resolution and displays the display image on the image displaying unit having the second resolution. A portion of the input image is enlarged and displayed on the image displaying unit so that the user can determine the clarity of the input image. [0076] The method 200 of controlling the digital photographing apparatus includes receiving the input image (S 201 ), and determining whether to enlarge the input image (S 202 ). The operation S 203 of displaying the enlarged image includes setting a portion of the input image that is to be enlarged as an enlarged display region having a resolution of a third pixel number (S 301 ); dividing the second pixel number by the third pixel number, rounding the result to the nearest integer, calculating the number of display frames that is to be displayed on the displaying unit, and dividing the enlarged display region into display images according to the number of the display frames (S 303 ); and displaying each of the display images on the image display unit (S 304 , S 305 , and S 306 ). [0077] In operation S 301 , the portion of the input image that is to be enlarged is set as the enlarged display region, which has the resolution with the third number pixel. That is, the third pixel number expresses the size of the enlarged display region in pixel numbers. [0078] The enlarged display region may be set in a variety of ways in operation S 301 . When enlarging and displaying the enlarged display region, a region in which the user can readily determine the clarity of the input image can be set as the enlarged display region. Here, the user may personally set the enlarged display region via a user input unit of the digital photographing apparatus. [0079] As an example of the method of setting the enlarged display region of S 301 , an input image can be divided into at least two regions, and a region having the most edges may be set as an enlarged display region. That is, the divided regions are examined and a region with the most edge information is found and set as the enlarged display region. [0080] Also in operation S 301 , when a face of a person is included in an input image, the face region may be set as the enlarged display region. Here, color information of the input image can be extracted and the face can be detected by comparing the color information with a face tone of a general person, and it can be determined whether the face of a person is included in the input image. [0081] According to another embodiment of the present invention, in the method of setting the enlarged display region of S 301 , a focus zone for adjusting a focus when automatically focusing, which is used in a conventional method of controlling a digital photographing apparatus, may be set as an enlarged display region. [0082] FIG. 10 is a view illustrating the setting of the enlarged display region (S 301 ) in the displaying of the enlarged input image described in FIG. 8 . In the present embodiment, the whole input image is displayed on the image displaying unit, and the user may select how far a region to be enlarged and displayed is from the center of the input image. For example, a region corresponding to, for example, 1/9, 1/16, and 1/25 region from the center of the input image may be selected as an enlarged display region. [0083] In operation S 303 , the enlarged display region set in operation S 301 is divided into at least two display images. A number of display frames that are to be formed is calculated from the third pixel number of the enlarged display region and the second pixel number of the image displaying unit, and the enlarged display region is divided into equal number of display images and display frames. Here, the number of display frames can be calculated by dividing the third pixel number by the second pixel number and rounding the result into an integer. The result can be rounded to the nearest whole number, rounded up or rounded down. [0084] Also, the method 200 of controlling the digital photographing may further include setting a displaying ratio of a pixel number of an input image that is to be displayed on the image displaying unit and a pixel number of a display image that is displayed on the image displaying unit (S 302 ). Here, the displaying ratio may be a ratio of a pixel number of an input image that is to be displayed on the image displaying unit and a pixel number of a display image that is displayed on the image displaying unit in which 1:1 displaying ratio is preferable. [0085] Operation S 302 is further included in case the user desires to check a further enlarged image simultaneously, and thus the user may select to perform operation S 302 . For example, the display ratio may be 1:1, 2:1, 3:1, . . . , n:1, or set by the user. [0086] FIG. 11 is a view illustrating the dividing of the enlarged display region into display images in the displaying of the enlarged input image described in FIG. 8 . In this case, when further including operation S 302 , the number of the display frames is calculated by dividing the third pixel number by the second pixel number, multiplying the result by a display ratio n, and then rounding the result into an integer in operation S 303 . [0087] Here, it may be difficult to reproduce the set enlarged display region in the selected display ratio in a single operation. For example, when 2/5 of an input image is selected to be displayed after being enlarged in a 1:1 ratio, when the size of the input image is 1,000,000 pixels and the size of an LCD is 100,000 pixels, 2/5 of the 1,000,000 pixels, that is, 400,000 pixels, is divided into four display frames, each having 100,000 pixels, and the four display frames are reproduced. [0088] The display images are displayed on the image displaying unit in operations S 304 , S 305 , and S 306 . In operation S 304 , a method of displaying the display images is determined, in operation S 305 , the display images are displayed in an automatic slide show, and in operation S 306 , the display images are manually displayed. [0089] In operation S 304 , whether to display the display images in the automatic slide show or manually display the display images is determined from a default setting. When photographing using the digital photographing apparatus and checking the photographed image, a user may select whether to use a function in which an enlarged display region is automatically enlarged according to a photographing condition. [0090] In operation S 305 , the display images are sequentially displayed on the image displaying unit when the automatic slide show is selected in operation S 304 . [0091] The configuration of enlargement reproduction, the enlarged display region, the enlargement ratio, the method of displaying, etc. is set by a user with a menu. If the enlarged display function is to be performed on the enlarged display region of a photographed image, the image is photographed as described in FIG. 8 , immediately an entire image is briefly shown, and the enlarged display region is enlarged and displayed according to the settings. Here, the enlarged display function performed on the enlarged display region is selected when a photographing condition is in a manual focus control mode, when a near subject is being photographed, when photographing using a telephoto zoom, when over 1/30 second of exposure is needed, etc. [0092] In operation S 305 , it is preferable that a display image at the center of the enlarged display region is displayed on the image displaying unit, and the display images in the clockwise direction are sequentially displayed on the image displaying unit in the enlarged display region. In FIG. 9 , which schematically illustrates the displaying of the enlarged image (S 203 ) described in FIG. 8 , an entire input image is divided into regions using vertical and horizontal lines as shown, and regions labeled 1 through 9 sequentially are set as the enlarged display region. [0093] In each of operations S 305 and S 306 , region 1 is first enlarged and displayed on the entire image displaying unit. In operation S 305 , display images of region 1 through 9 are sequentially displayed on the entire image displaying unit, which is in the clockwise direction from the center of the image displaying unit. [0094] FIGS. 12A through 12D are views illustrating the displaying of the respective divided display images in FIG. 11 in the automatic slide show. The region of the entire input image that is divided by dotted lines forming a quadrangle at the center thereof according to a setting is set as the enlarged display region. Then, the enlarged display region is divided into regions by horizontal and vertical lines. [0095] The display images shown in FIGS. 12A through 12D are sequentially displayed on the entire image displaying unit in operation S 305 . In this case, the display images are sequentially displayed in the counterclockwise direction. Also, when displaying the display images on the image displaying unit using the automatic slide show, the slide show may stop if an interruption occurs in the middle of the slide show. [0096] In operation S 306 , when manually displaying the display images according to the determination result in operation S 304 , one of the divided display images is displayed on the image displaying unit, and each of the display images selected by external input is displayed. When manually displaying the display images according to the external input, a region selected by the user may be displayed and not the images in display frame units which are formed in operation S 303 . [0097] That is, when manual display is selected, a center frame is reproduced and an image may be displayed in a pre-set pitch units, and not frame units, by moving the enlarged display region little by little to a desired direction using user operating keys. [0098] As illustrated in FIGS. 9 and 12A through 12 D, when enlarging a portion of the input image and displaying the display images on the image displaying unit in operations S 305 and S 306 , the entire input image can be reduced and displayed on a portion of the image displaying unit on which the display images are displayed. The reduced entire input image can be surrounded by, for example, a quadrangular line so that it is distinguishable from the display image. The reduced entire input image is displayed to indicate which part of the entire input image the display image is taken from and displayed on the image displaying unit. [0099] In addition, the method 200 of controlling the digital photographing apparatus can be adopted in a digital photographing apparatus according to an embodiment the present invention. [0100] As described above, in a method of controlling a digital photographing apparatus according to the present invention, a portion of a photographed image is enlarged and displayed on an image display device in consideration of a difference in a resolution of an image sensor and a resolution of the image displaying device. Thus, a user may check the quality of the photographed image and may conveniently determined whether the photographed image has the quality the user desires. In addition, the user may easily determine, for example, the clarity of the photographed image or whether the photographed image is well focused. [0101] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

A method of controlling a digital photographing apparatus to enlarge and reproduce an image is provided. The method includes determining whether an instruction is given in an image reproduction mode, dividing the input image into a predetermined number of blocks when it is determined that the instruction is given, enlarging the small image corresponding to a specific block from among the predetermined number of blocks, and displaying the enlarged small image on an entire screen.

BACKGROUND OF THE INVENTION This invention relates to the pneumatic conveyance of materials and, in particular, to improved apparatus for introducing fluent bulk materials into a pneumatic conveying line. In the pneumatic conveyance of various bulk materials it is well known to provide a hopper or similar collecting arrangement which supplies the bulk material to a feed tube. The feed tube in turn is provided with a suitable means, such as a feed auger, which advances the bulk material along the feeding tube and into some form of chamber through which a current of air is passed by way of air inlet and air outlet lines connected to that chamber. The bulk material which is deposited within the chamber is intended to be fluidized by the air current and carried by the air current through the air line outlet and along the outlet conveying line to a storage site, such as a silo. In order to prevent air blow-back through the feed tube and alongside the auger, the outlet end of the feed tube is provided with a gate or other suitable one way valve arrangement which is intended to close when the flow of bulk material into the chamber slows down or stops thereby to prevent air blow-back through the feed tube and feed hopper. If blow-back occurs, the bulk material being handled may be sprayed around thus creating a potential hazard and, at least, a substantial cleanup problem. The prior art has provided various devices of the nature indicated above as exemplified generally by the following U.S. Pat. Nos.: ______________________________________ 560,381 - Wainwright et al May 19, 18963,106,428 - Lenhart Oct. 8, 19633,460,869 - Herr Aug. 12, 19693,588,180 - Herr June 28, 1971______________________________________ One notable problem with all or virtually all of the prior art devices is that they were prone to a build-up of the material on or adjacent to the movable gate. After a period of time the gate would not close properly thus creating a substantial blow-back problem. Many of the prior art units were also prone to plugging thus requiring substantial down-time to partially dismantle the device and to remove the plugged up material. Part of the problem with many of the prior art designs is that the internal configuration in the region of the gate is such that inadequate fluidization of many materials does not take place thus resulting in the build-up of deposits which eventually render the apparatus inoperative. In addition, no means were provided whereby the operator could observe the action occurring in the vicinity of the gate and take appropriate remedial action before plugging or blow-back occurred. Another problem inherent in many or all of the prior art devices is that they are not sufficiently versatile. Most of them were designed for either only one or a very small number of very similar products. If an attempt is made to use them with products having substantially different characteristics, problems resulting from gate deposit build-up, plugging, and blow-back back soon arise. Another problem inherent in most, if not all, of the prior art devices of the type under consideration is that they are only intended to be used in one fixed location. This necessitates the use of highly specialized and relatively expensive equipment for transporting dry bulk materials. In the past these dry bulk materials have been transported by pneumatic trailers and a relatively small number of specially designed rail cars. In the case of the so-called pneumatic trailers (which are intended for highway use), the entire vessel or container is pressurized during the unloading operation and this necessitates an extremely expensive structure. This, in turn, tends to increase shipping costs. Because of the specialized nature of the container, the pneumatic trailer is generally only usable one way thus meaning that the return trip is made with no load. This again keeps shipping costs high. Various fluent bulk materials, such as cement, lime, sand, salt and various dry chemicals, are commonly carried in this fashion. SUMMARY OF THE INVENTION It is a general objective of the present invention to alleviate or overcome the various difficulties noted above and to provide apparatus for successfully introducing a wide variety of fluent bulk materials into a pneumatic conveying line and which is substantially free from the plugging and blow-back problems inherent in the prior art devices. A further objective is to provide apparatus of the type under consideration wherein the operator can readily observe the action occurring in the vicinity of the gate and take remedial action so as to increase or decrease the rate of flow of the bulk material thereby to provide optimum performance. A further objective of the invention is to provide apparatus of the type under consideration which is readily portable from one job site to another and which is of a relatively low-profile configuration so that it can be slipped under a conventional hopper bottom trailer so as to receive the bulk material from it thus enabling use of the much less expensive hopper bottom trailers, which trailers can carry a load both ways, thus substantially reducing overall shipping costs. A further object of the invention is to provide apparatus of the type under consideration which is capable of successfully handling a very wide variety of fluent bulk materials, all the way from very light and relatively easily handled materials such as flour right through to the more difficult materials such as cement, lime, salt and the like. Accordingly, the present invention in one aspect relates to apparatus for introducing fluent bulk materials into a pneumatic conveying line, comprising: (a) a fluidizing chamber having an air line inlet and an air line outlet for connection to incoming and outgoing air lines respectively; (b) a feed tube connected to the fluidizing chamber, and having an outlet end disposed within said chamber; (c) an assembly for effecting movement of the bulk material through said feed tube from a source of supply into the interior of the fluidizing chamber so that the material may, during use, be fluidized by an air flow passing through the fluidizing chamber from said air line inlet to and through said air line outlet and carried therewith out through the air line outlet; (d) a gate located at said outlet end of said feed tube within the fluidizing chamber and exposed, in use, to the air flow passing from the air line inlet to and through the air line outlet and responsive to opposing forces exerted, thereon by the bulk material moving through the feed tube and the pressure of the air within the fluidizing chamber for permitting flow of said bulk material into said fluidizing chamber through the feed tube and at the same time preventing blow back of air from the fluidizing chamber through said feed tube. In accordance with an aspect of the invention, the air line inlet and the air line outlet noted above are located in substantial alignment with one another along a first axis. The feed tube defines a further axis which is laterally arranged relative to the first axis and is displaced from it in such a way that, during use, bulk material exiting the outlet end of the feed tube falls downwardly under the influence of gravity and passes into and is fluidized by the air flow passing through the fluidizing chamber along the first axis from the air line inlet to the air line outlet. Preferably and in accordance with another aspect of the invention, the gate is hinged adjacent its upper edge for movement from a closed position in close contacting relation to the outlet end of the feed tube to and through a range of partially open positions. During use, the bulk material applies a force to one face of the gate while the pressure of the air applies a force to the opposing face of the gate. In a preferred form of the invention, the fluidizing chamber includes a gate chamber and an air duct section. The air duct section typically includes a tubular section having the air line inlet and the air line outlet disposed at opposing ends thereof. The gate chamber is secured to the air duct section and has its lower end portion opening into and freely communicating with the interior of the duct section. As a result of this construction, the bulk materials falling downwardly by gravity from the outlet end of the feed tube pass into a central region of maximum air flow velocity within the air duct section to effect substantially complete fluidization of the bulk material. Still further according to a feature of the invention, the above-noted gate is disposed in the fluidizing chamber such that, during use, a substantial lower portion Of the gate is disposed within the region of maximum air flow velocity so that the resulting air currents tend to keep the gate clear of deposits which might otherwise tend to prevent full closure of the gate. In a preferred form of the invention, the above-noted assembly for effecting movement of the bulk material through the feed tube includes a variable speed drive and suitable means to control this drive. The control means preferably includes start, stop and reverse valve means for controlling the movement of material through the feed tube. This facilitates safe operation and allows the safe removal of certain foreign materials that may from time to time become lodged in the feed tube. The fluidizing chamber is typically provided with a viewing port above the gate so that the operator can control the rate of movement of material through the feed tube by way of a speed control valve in accordance with conditions as observed within the fluidizing chamber. All of this permits remedial action to be taken before a plugging situation occurs. As a further desirable feature of the invention, a low profile inlet hopper is connected to an inlet end of the feed tube. This low profile hopper allows the apparatus to be located below and to receive bulk material from the outlet of a hopper bottom trailer or the like. Inlet flow control means are typically provided in the hopper to control the rate of flow of bulk material into the feed tube and the device for effecting movement of the bulk material through the feed tube. The device for effecting such movement is typically a feed screw, otherwise known as a feed auger. The above-noted means (e.g. the feed auger) for effecting movement of the bulk material through the feed tube is located in a lower portion of the hopper. The inlet flow control means is typically disposed just above the previously noted means (e.g. feed auger) and may take the form of an inverted V-shaped baffle having suitable means thereon such as adjustable plates arranged to allow the rate of flow of material from the hopper toward and into the feed tube to be varied as desired. Further features, objects and advantages of the present invention will become apparent to those skilled in the art after reading the following description of a preferred embodiment of the invention taken in conjunction with the appended drawings. BRIEF DESCRIPTION OF THE VIEWS OF DRAWINGS FIG. 1 is a perspective view of an apparatus for introducing fluent bulk materials into a pneumatic conveying line; FIG. 2 is a side elevation view of the apparatus, certain portions of the same being out away so as to show the internal feed auger; FIG. 3 is a top plan view of the apparatus, a portion of the feed tube being cut away to show the feed auger and the flow control assembly for the hopper having been removed so as to also show the feed auger; FIG. 4 is a top plan view of the hopper with the flow control assembly in place above the feed auger; FIG. 5 is a partial section view through the fluidizing chamber showing the outlet end of the feed tube as well as open and closed positions of the gate within the fluidizing chamber; FIG. 6 is an end elevation view of the apparatus, a wall of the fluidizing chamber having been cut away so as to show the internal configuration including the outline configuration of the gate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings there is shown a preferred form of the apparatus for introducing the fluent bulk materials into the pneumatic conveying line, such apparatus being generally designated by reference numeral 10. The apparatus includes a low-profile hopper 12 which is mounted adjacent one end of an elongated feed tube 14. Feed tube 14 is connected to and enters into a fluidizing chamber 16. The fluidizing chamber 16 is provided with a flow of pressurized air from a suitable blower, preferably a positive displacement lobe blower (not shown), by way of an inlet air line 18 (shown in dotted lines), and the suspended or fluidized bulk material-air mixture leaves via air outlet line 20 (also shown in dotted lines) and is transported thereby to a suitable storage means such as a silo (not shown). The above-noted infeed hopper 12 is provided with four shallowly sloping walls 22, the lower edges of which are secured, as by welding, to the wall of the feed tube 14. The overall height of the apparatus is preferably kept to about 12 inches so that the hopper end of the apparatus may be slid beneath a hopper bottom trailer and the hopper 12 positioned below an outlet port. In order to control the flow of bulk material from the interior of hopper 12 into a feed auger 24 which extends within the feed tube 14, there is provided an inverted V-shaped baffle 26 which extends between and is welded to the opposing end walls 22 of the hopper. This baffle 26 is provided with an opposed pair of adjustment plates 28 which may each be slid upwardly or downwardly in the direction of arrows A thereby to increase or decrease the size of the gap existing between the lower edge of the respective adjustment plate and the adjacent hopper wall 22. These adjustment plates are secured to baffle 26 via a multiplicity of bolts 30 which extend through suitable slots in the adjustment plates 28 thereby to allow the plates 28 to be firmly secured in the desired adjusted positions. The above-noted feed auger 24 is of a conventional design and extends from one end to the other of the feed tube 14. In order to drive the feed auger 24 in rotation, there is provided, at the hopper end of the feed tube 14, a hydraulic drive motor 32 of any suitable commercially available variety, this hydraulic motor 32 being secured to the end of the feed tube via a mounting bracket 34. The outlet drive shaft of the hydraulic motor is connected to the shaft of the feed auger 24 by way of a suitable flex coupling 36. A short skid 38 is also affixed to the hopper end of the feed tube 14 and extends below the hydraulic motor 32 both to protect the hydraulic motor and to allow the apparatus to be slid into position beneath a hopper bottom trailer or the like. With reference to FIG. 3, the hydraulic motor 32 is controlled by way of a control valve module 39 mounted by a suitable bracket to the fluidizing chamber 16. By means of this control valve 39, (which is of any suitable commercially available variety), the operator can start, stop and reverse the motor. To increase or decrease the rate of rotation of the hydraulic motor a flow control valve 41 is provided. These valves together enable the operator to exert a close degree of control on the rate at which the feed auger 24 conveys bulk material toward the fluidizing chamber 16 and enables the operator to take remedial action when appropriate. As noted previously, the fluidizing chamber is provided with air line inlet 40 and air line outlet 42 which are connected to respective inlet and outlet air lines 18 and 20. The incoming and outgoing air lines are each provided with a semi-smooth bore thereby to reduce air friction and the air line inlet and outlet also are each preferably provided with couplers enabling quick connections to be made to the incoming and outgoing air lines. One suitable type of coupler is known as the "Cam-Lock" coupler which provides for quick attachment and detachment while at the same time providing a smooth internal bore so as to reduce air friction losses as well as providing a tight air seal at the point of connection. With particular reference to FIGS. 5 and 6, it will be seen that the fluidizing chamber 16 comprises a gate chamber 50 attached to and located above an air duct section 52. The air duct section comprises a tubular section having the above-noted air line inlet 40 and the air line outlet 42 disposed at opposing ends of same. The box-like gate chamber 50 is secured, as by welding, to the air duct section 52 and has its lower and portion opening into and freely communicating with the interior of the air duct section 52 as clearly illustrated in FIGS. 5 and 6. It was previously noted that the feed tube 14 has its outlet end disposed within the fluidizing chamber 16. As shown in FIGS. 5 and 6, a gate 54 is located at the outlet end of the feed tube 14 within the fluidizing chamber 16 and is exposed, in use, to the airflow which passes through the fluidizing chamber from the air line inlet 40 to and through the air line outlet 42. This gate 54 is responsive to the opposing forces exerted thereon by the bulk material which is being forced through the feed tube 14 by the feed auger 24, and by the pressurized air within the fluidizing chamber. In operation this gate 54 acts to permit the flow of bulk material into the fluidizing chamber 16 while at the same time interacting with the bulk materials to prevent blow-back of pressurized air from the fluidizing chamber through the feed tube 14 and outwardly of the inlet hopper 12. In operation, the bulk material is compressed somewhat as the feed auger pushes the material against the inside surface of the gate thus forming a "plug" of moving material that interacts with the surrounding structures to prevent blow-back. It will be seen with particular reference to FIGS. 5 and 6 that the air line inlet and the air line outlet 40, 42 are located in substantial alignment with one another along a first axis which extends lengthwise and is centered with the air duct section 52 of the fluidizing chamber. The feed tube 14 defines a further axis (which axis extends lengthwise of the feed tube and is centered with the rotation axis of the feed auger 24), such further axis being transversely arranged relative to the first axis noted above. The further axis defined by feed tube 14 is also displaced upwardly from the first axis in such a way that, during use, the bulk material exiting from the outlet end of the feed tube 14 falls downwardly under the influence of gravity and hence passes into and is fluidized by the air flow passing through the fluidizing chamber 16 along the first axis from the air line inlet 40 to the air line outlet 42. The above-noted gate 54 comprises a flat plate of sufficient size as to butt up firmly against the inner end of the feed tube 14 when gate 54 is in its closed position. The gate is hinged adjacent its upper edge by way of hinge 56 fixed to the outlet end of the feed tube 14. Gate 54 can thus pivot from a closed position in close contacting relation to the outlet end of the feed tube 14 to and through a range of partially open positions. One such partially open position is illustrated in dashed lines in FIG. 5. During use, as noted previously, the incoming bulk material applies a force to one face of the gate 54 while the pressure of the air within the fluidizing chamber 16 applies a force to the opposing face of the gate. By virtue of the structure as described above and illustrated in the drawings especially the relationship between the feed tube outlet and the air duct section of the fluidizing chamber, the bulk materials entering fluidizing chamber 16 fall downwardly by gravity from the outlet end of the feed tube 14 and almost immediately pass into a central region of maximum air flow velocity within the above-described air duct section 52 thus effecting substantially complete fluidization of the bulk material. The bulk material has almost no chance of lodging against and building up on any fixed surface from whence it could create gate closure or plugging problems. In this connection the small downwardly extending baffle portions 57 (see FIG. 6) located in flanking relation to the gate 54 are of assistance in establishing air current patterns which enhance the fluidization process. It will also be noted that the abovedescribed gate 54 is disposed in the fluidizing chamber 16 in a manner such that, during use Of the apparatus, a substantial lower portion of the gate (approximately one-quarter to one-third of it) is disposed within the region of maximum air flow velocity so that the resulting air currents tend to keep the gate surfaces clear of deposits which might otherwise tend to prevent full closure of the gate. The upper or top face of the gate chamber 50 is provided with a viewing port 58, this viewing port typically including a sheet of "Plexiglass" material thus enabling the operator to observe conditions existing within the fluidizing chamber 16, particularly conditions in the immediate region of the gate 54. By manipulating the closely adjacent hydraulic flow control valve 41, the operator can control the rotation of the feed auger 24 in accordance with conditions as observed within the fluidizing chamber 16. This permits remedial action to be taken before a plugging condition actually occurs. For the further guidance of those skilled in this art the following detailed example is set forth, it being realized that the invention is not to be limited to the details given but that reasonable modifications may be made by those skilled in this art. EXAMPLE With reference again to FIG. 5 some details for a typical embodiment are given below: ______________________________________DIMENSIONS:A diameter of air duct section 6.0 ins.B distance between LC of feed 5.3 ins. tube and LC of air duct sectionC total height of fluidizing chamber 13.4 ins.D total height of a gate 9.3 ins.E diameter of feed tube 8.0 ins.AIR LINE:semi-smooth bore 6 in. inside dia.air line length (incoming & outgoing) 50 ft. approx."Cam-Lock" couplers-quick detach-tight seal smooth boreBLOWER:Positive displacementlobe-type (make "Vana"; model RSBS) 1100 cfm @ 6 p.s.i. output (this example)MATERIAL:saltRATE OF CONVEYANCE:rate of flow = 1 ton/minute approx.______________________________________ It will be realized by those skilled in this art in light of the foregoing description that the apparatus described herein is extremely versatile and capable of being utilized in an extremely wide variety of situations. The apparatus is extremely simple and, being portable, can be readily carried from one job site to another in a relatively small vehicle, which vehicle also carries the other related ancillary equipment such as the inlet and outlet air lines, the lobe blower, and the hydraulic pump supply lines and hydraulic reservoir and so on. It should also be realized that several of the devices as described may be used, each receiving bulk material from a different source to enable the blending of several fluent bulk materials to provide a specific blend, the several devices being linked together by a common conveying line and sharing a common blower. Numerous advantages will be readily apparent to those skilled in the art. Preferred embodiments of the invention have been described by way of example. Those skilled in this art will realize that numerous modifications and modifications may be made while remaining within the scope of the invention. Accordingly, the invention is not to be limited to the embodiments described. For definitions of the invention reference is to be had to the appended claims.

A portable pneumatic conveyor for various bulk materials includes a hopper which supplies the bulk material to a feed tube. The feed tube is provided with a feed auger which advances the bulk material along the feed tube and into a chamber through which a current of air is passed by way of air inlet and air outlet lines connected to that chamber. The bulk material which is deposited within the chamber is fluidized by the air current and carried by the air current through the air line outlet and along the outlet conveying line to a storage site, such as a silo. In order to prevent air blow-back through the feed tube and alongside the auger, the outlet end of the feed tube is provided with a gate which is intended to at least partly close when the flow of bulk material into the chamber slows down or stops.

FIELD OF THE INVENTION The present invention relates to a media gateway control (megaco) protocol management method using a network adaptor, and more particularly, to a megaco protocol management method for independently managing the megaco protocols according to changes of low level network protocols by implementing the megaco package in the network adaptor and a computer readable recording medium for executing the same method. DESCRIPTION OF THE PRIOR ART A Voice over Internet Protocol (VoIP) is an application technology of the Internet for transferring voice data that is compressed and packetized by end-to-end channel setting base upon Internet Protocol (IP) address. A gateway is necessary so as to provide VoIP through the Internet and terminates Public Switched Telephone Network (PSTN). The gateway is an apparatus for interconnecting signals and media between two networks. The VoIP is connected to a Signaling Gateway (SG) by a media gateway controller for controlling a call process. The media gateway controller controls the media gateway by translating a call number, allocates available Internet Protocol (IP) address by controlling the media gateway and interconnects voice traffics of each terminal by managing compression methods to generate end-to-end IP packet. By separating the media gateway and the signal gateway, independence of an applied protocol is guaranteed, protocol is scalable and service can be easily changed although a new service is added. A gateway is functionally divided into a signal gateway, a media gateway and a media gateway controller. The media gateway transforms data that are used in circuit switching network into data that are used in packet switching network. The media gateway includes a Residential Gateway (RGW), an Access Gateway (AGW) and a Trunk Gateway (TGW). A media gateway control (megaco) protocol is used for communication between the media gateway and the media gateway controller in VoIP service. The megaco protocol defines a communication method between the media gateway and the media gateway controller and is a protocol in master-slave format that the media gateway controller sends instructions for connecting and managing media gateways. Traffic processing of the media gateway is similar to that of node in typical switch. Also, a megaco protocol engine supports communication between the media gateway and the media gateway controller by using the megaco protocol. The megaco protocol engine is interconnected to many low level network protocols, e.g., a Transmission Control Protocol (TCP), a User Datagram Protocol (UDP), Stream Control Transmission Protocol (SCTP), an Asynchronous Transfer Mode (ATM) and Time Division Multiplexer (TDM). New version of the protocol has been developed day by day. As a result, the number of the protocols for being considered by the megaco protocol engine in order to be matched is incredibly increased. Therefore, a source of the megaco protocol engine must be revised whenever the megaco protocol engine is installed according to changes of network protocols or protocol versions. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a megaco protocol management method for independently managing the megaco protocols according to changes of low level network protocols by implementing the megaco package in the network adaptor and a computer readable recording medium for executing the same method. In accordance with an aspect of the present invention, there is provided a method for managing media gateway control (megaco) protocols by using a network adaptor, including steps of: a) requesting an installation of a megaco protocol package of low level network protocols to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table in case that the megaco protocol does not exist in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package in case that the megaco protocol exists in the network protocol table; and e) installing the megaco protocol packages and the specific megaco protocols and managing the megaco protocols. In accordance with another aspect of the present invention, there is provided a computer readable recording medium including a microprocessor in communication systems using a megaco protocol, including the instructions of: a) requesting an installation of a megaco protocol package of low level network protocols to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table in case that the megaco protocol does not exist in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package in case that the megaco protocol exists in the network protocol table; and e) installing the megaco protocol packages and the specific megaco protocols and managing the megaco protocols. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which: FIG. 1 is an exemplary block diagram showing a Voice over Internet Protocol (VoIP) service system in accordance with the present invention; FIG. 2 is an exemplary block diagram illustrating a media gateway in accordance with the present invention; FIG. 3 is an exemplary block diagram depicting a media gateway control (megaco) protocol engine in accordance with the present invention; FIG. 4 shows a network protocol table and a megaco package list in accordance with an embodiment of the present invention; FIG. 5 is a flowchart for explaining management procedures of the megaco protocol by using a network adaptor in accordance with the embodiment of the present invention; and FIG. 6 is a flowchart for explaining procedures for adding a new protocol in the network protocol table by using a network adaptor in accordance with the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exemplary block diagram showing a Voice over Internet Protocol (VoIP) service system in accordance with the present invention. A media gateway control (megaco) protocol is the protocol used in the Internet. It is distinguished from a protocol used in a Public Switched Telephone Network (PSTN). A call processing unit and a media processing unit were built on one device for the PSTN and the mobile network. However, the call processing unit and the media processing unit are separately implemented as an independent device for the Internet network by standardization of the megaco protocol. Such a separation of call processing unit and media processing unit makes it possible to expand media transfer device for expanding the network. Referring to FIG. 1 , the terminals include an Internet outgoing terminal 21 , a wireless terminal 20 connected to an access point 19 over the air, a terminal 16 connected to a Residential Gateway (RGW) 6 , a terminal 17 connected to an Access Gate (AGW) 7 and a terminal 18 connected to a Private Branch Exchange (PBX) 8 . The terminal connected to the Internet requests an Internet voice telephone service. The request is transferred to a call server 1 through a media gateway controller 2 . Internet telephone call is connected to the PSTN 10 or the mobile network 11 through a Signal Gateway (SG), a Signaling Transfer Point (STP) and a Service Control Point (SCP). Once the Internet telephone call is connected, the Media Gateway Controller (MGC) 2 controls a Trunk Gateway (TGW) 9 by using the megaco protocol to deliver the call to the terminal of the PSTN or the mobile network through a switch 12 , a Mobile Switching Center (MSC) 13 or a Packet Data Serving Node (PDSN) 14 . FIG. 2 is an exemplary block diagram illustrating a media gateway in accordance with the present invention. Referring to FIG. 2 , a media gateway 9 includes a call processing unit 201 for processing calls from a transmitting channel and a receiving channel, a protocol processing unit 202 for processing protocols, e.g., a megaco protocol, a system controller 206 for controlling a media gateway system, a codec 203 for transforming an analog voice signal to a digital voice signal, a trans-codec for transforming a different format of codec to an adequate format of codec, a dynamic media controller 205 for allocating and controlling voice codec data in Real-time Transport Protocol (RTP) payload and a hardware platform for providing a hardware for operating the media gateway 9 . A media gateway control protocol engine is included in a protocol processing unit 202 of media gateway. The media gateways 6 , 7 and 9 communicate with a media gateway controller 2 by using a media gateway control (megaco) protocol. FIG. 3 is an exemplary block diagram showing a megaco protocol engine in accordance with the present invention. Referring to FIG. 3 , a megaco protocol engine 300 includes a connection management unit 303 for managing a connection between a transmitter and a receiver, an instruction processing unit 304 for processing instructions, a package processing unit 305 for processing a megaco protocol package, a transaction management unit 306 for managing a transaction for call processing, a encoder/decoder for encoding and decoding the megaco protocol, a network adaptor 308 for interconnecting network protocols, an administration interface 302 for providing an interface in order to manage the megaco protocol, an Operating System (OS) 309 and a system adaptor 301 for connecting a Digital Signal Processor (DSP) 310 . Particularly, the network adaptor 308 interconnects various low level network protocols including a Transmission Control Protocol (TCP), a User Datagram Protocol (UDP), Stream Control Transmission Protocol (SCTP), an Asynchronous Transfer Mode (ATM) and Time Division Multiplexer (TDM). FIG. 4 shows a network protocol table and a megaco package list in accordance with an embodiment of the present invention. The network adaptor 308 needs a network protocol table 410 and a megaco package list 420 to install the megaco protocol package to the low level network protocols. The protocol information table (Network_Protocol_table) 410 is used for managing the megaco protocol according to characteristics of low level network protocol such as TCP, UDP or SCTP. Referring to FIG. 4 , the network protocol table 410 includes protocol identification (ID) 411 , protocol version information 412 , company information 413 and specific package ID 414 . The protocol ID 411 is an identification defined for discriminating a target network protocol to be interconnected by the megaco protocol engine. Examples of the protocol IDs are defined as 0001 for UDP, 0002 for TCP, 0003 for SCTP, 0004 for RTP, 0005 for ATM and 0006 for TDM in a preferred embodiment of this present invention. Protocol version information 412 represents a version of the protocol defined by the protocol ID 411 . Examples of the protocol version information 412 are defined as 01 for version 1 , 02 for version 2 and 03 for version 3 in a preferred embodiment of this present invention. Company information 413 is used for requesting specific megaco protocol in case that protocol standard is not defined or a protocol is developed regardless with the protocol standard. Examples of the company information 413 are defined as 0001 for company 1 , 0002 for company 2 , 0003 for company 3 and 0004 for company 4 in a preferred embodiment of this present invention. The specific package ID 414 is an identification of a megaco protocol package in a megaco package list 420 . The specific package ID 414 corresponds to package identification (ID) 421 of the megaco package list 420 . That is, the specific package ID 414 is used as an identification of the megaco protocol package that is installed in the megaco package list 420 . Regardless of adding or updating of a new low level network protocol, the megaco protocol package is independently installed in the megaco protocol engine by using the network protocol table 410 that has the protocol ID 411 , the protocol version information 412 and the company information 413 . The megaco package list 420 includes package ID 421 , package version information 422 , property information 423 , event information 424 , signal parameter 425 , statistic information 426 and specific protocol ID 427 for defining other characteristics of megaco protocol package. The package ID 421 is an identification of the megaco protocol package. The package version information 422 defines changes of the property information 423 , the event information 424 , the signal parameter 425 , the statistic information 426 and the special protocol ID 427 . The property information 423 defines data type. Examples of the property information 423 are string, UTF-8 string, integer, 4 byte signed integer, double, 4 byte signed integer, character, enumeration, sub-list and Boolean. The event information 424 is used for the media gateway controller 2 . The signal parameter 425 is an identification of information between the media gateway controller 2 and the media gateway. The statistic information 426 represents a unit, e.g., a second or a packet. The specific protocol ID 427 is an identification of a specific protocol. Management procedures of the megaco protocol in accordance with the present invention are explained by using the network protocol table and the megaco package list. FIG. 5 is a flowchart showing management procedures of the megaco protocol by using a network adaptor in accordance with the embodiment of the present invention. At step 501 , the media gateway 9 receives a list of requests for installing package from the media gateway controller 2 and requests an installation of the megaco protocol package to the network adaptor 308 . At step 502 , the network adaptor 308 receives the request for installing the megaco protocol package and searches a protocol of the list in the network protocol table 410 that has fields of the protocol ID 411 , the protocol version information 412 and the company information 413 . At step 503 , it is determined whether the protocol exists in the network protocol table 410 . If the protocol does not exist in the network protocol table 410 at step 503 , at step 504 , a new protocol is added in the network protocol table 410 and the management procedure is finished. If the protocol exists in the network protocol table 410 at step 503 , at step 505 , the specific package ID 414 is extracted from the network protocol table 410 and the network adaptor 308 searches the megaco protocol package in the megaco protocol package list 420 by using the specific package ID 414 . At step 506 , it is determined whether the searched megaco protocol package is the specific megaco protocol package by using the specific protocol ID 427 of the megaco protocol package list 420 . If the searched megaco protocol package is not the specific megaco protocol package at step 506 , the process proceeds to step 508 . If the searched megaco protocol package is the specific megaco protocol package at step 506 , at step 507 , the specific megaco protocol package is connected. At step 508 , it is determined whether every protocol of the list is processed completely. If every protocol in the list is not processed yet, a procedure continues to step 502 . At step 509 , megaco protocol packages and specific megaco protocol packages are installed. FIG. 6 is a flowchart showing procedures for adding a new protocol in the network protocol table by using a network adaptor in accordance with the embodiment of the present invention. At step 601 , a request for adding a new protocol in the network protocol table 410 is received. At step 602 , it is determined whether the new protocol exists in the network protocol table 410 . If the new protocol exists in the network protocol table 410 , the process is finished. If the new protocol does not exist in the network protocol table 410 , at step 603 , fields of the protocol ID 411 , the protocol version information 412 and the company information 413 is stored in the network protocol table 410 . At step 604 , it is determined whether the new protocol needs a new megaco protocol package. If the protocol does not need a new megaco protocol package, at step 605 , the specific package ID is stored in the existing field of the specific package ID 414 . If the protocol needs a new megaco protocol package, at step 606 , a new megaco protocol package is generated, a new package ID 421 of the new megaco protocol package is allowed and the new package ID 421 is stored. At step 607 , the new megaco protocol package is added in the megaco package list 420 and each field of the megaco package list 420 is stored. At step 608 , the new package ID 421 is stored in the new specific package ID 414 of the network protocol table 410 . As mentioned above, although the number of network protocols and protocol versions has been increased, the megaco protocol can be operated by independently managing the megaco protocol according to changes of lower layer network protocol by implementing the megaco package in the network adaptor without revising the source of the megaco protocol engine. The method of the present invention can be implemented as a program and stored in a computer readable medium, e.g., a CD-ROM, a RAM, a ROM, a Floppy Disk, a Hard Disk, and an Optical magnetic Disk. While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

The present invention manages media gateway control (megaco) protocols according to changes of lower layer network protocol by implementing the megaco package in the network adaptor. A method for managing the megaco protocols by using a network adaptor includes steps of: a) requesting an installation of a megaco protocol package to a network adaptor; b) determining whether the megaco protocol exists in a network protocol table; c) adding a new protocol in the network protocol table; d) searching a specific megaco protocol package in the megaco protocol package list by using the specific package ID and connecting the specific megaco protocol package; and e) installing the megaco protocol packages and the specific megaco protocols, and managing the megaco protocols.

BACKGROUND [0001] 1. Technical Field [0002] The present disclosure relates to illumination, particularly to an illumination device with decreased thickness, and more particularly to a low-profiled LED (light emitting diode) ceiling lamp. [0003] 2. Description of Related Art [0004] A traditional lamp generally includes a housing and a plurality of light sources mounting on the housing. A lamp cover is fastened to one side of the housing to cover the light sources, and a lamp seat is fastened to the other side of the housing to receive electronic elements therein for providing power for the light sources. In the lamp described above, the lamp seat positioned at one side of the housing will occupy a certain space thereto make the lamp have a relatively large thickness. When such a thick lamp is used as a ceiling lamp for a room with a relatively small height, a feeling of constriction will be exerted to a person in the room. Moreover, such a lamp is high power consuming. [0005] What is needed, therefore, is an illumination device which can overcome the limitations described. BRIEF DESCRIPTION OF THE DRAWINGS [0006] Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. [0007] FIG. 1 is an isometric view of an illumination device according to one embodiment of the present disclosure. [0008] FIG. 2 is an inverted view of FIG. 1 . [0009] FIG. 3 is an exploded view of the illumination device of FIG. 1 . [0010] FIG. 4 is an inverted view of FIG. 3 . DETAILED DESCRIPTION [0011] Referring to FIGS. 1-2 , an illumination device 100 according to an embodiment of present disclosure includes a housing 20 and a lamp seat 10 fastened to one side of the housing 20 . The illumination device 100 is particularly used as a low-profiled ceiling lamp with a light source consisting of light emitting diodes. [0012] Referring also to FIGS. 3-4 , the lamp seat 10 includes an upper cover 12 and a lower cover 14 interconnected together. Electronic elements 16 are received between the upper cover 12 and the lower cover 14 . [0013] The upper cover 12 has a substantially trilobate shape, and includes an upper plate 122 and three lateral plates 124 extending downwardly from the upper plate 122 . A central portion of the upper plate 122 protrudes out away from the housing 20 . Three lateral sides of the upper plate 122 are curved towards the central portion. In this embodiment, the three lateral plates 124 one-to-one correspondingly extend down from the three lateral sides of the upper plate 122 . The lateral plates 124 are also curved towards the central portion of the upper plate 122 . The upper plate 122 and the lateral plates 124 cooperatively form a receiving chamber 126 therebetween. Each corner of the upper plate 122 has a first buckle 128 . The first buckle 128 extends downwardly from the upper plate 122 towards the housing 20 . One end of the first buckle 128 is bent inwardly to form a hook to connect with the lower cover 14 . Each lateral plate 124 has two snaps 129 extending horizontally and inwardly from an inner side thereof. The snaps 129 are configured to further strengthen the connection between the upper cover 12 and the lower cover 14 . [0014] The lower cover 14 has a similar configuration with the upper cover 12 . The lower cover 14 includes a bottom plate 142 and an annular sidewall 144 on a central portion of the bottom plate 142 . The sidewall 144 extends vertically from the bottom plate 142 to the upper cover 12 . The central portion of the bottom plate 142 surrounded by the sidewall 144 protrudes outwardly away from the upper cover 12 and forms a protrusion 146 opposite to the sidewall 144 . The protrusion 146 and the sidewall 144 cooperatively define a space 18 for receiving the electronic elements 16 therein. Each corner of the bottom plate 142 has a second buckle 148 . The second buckle 148 extends from the lower cover 14 towards the upper cover 12 . One end of the second buckle 148 is bent to form a hook to clasp with the first buckle 148 . Each corner of the bottom plate 142 defines two holes 141 therein. Screws or rivets (not labeled) are used to extend through the housing 20 and secure in the holes 141 to fix the lamp seat 10 and the housing 20 together. The holes 141 can be blind holes or through holes. [0015] The bottom plate 142 has a plurality of third buckles 149 one-to-one corresponding to the snaps 129 of the upper cover 12 . The third buckles 149 extend from the bottom plate 142 to the upper cover 12 . One end of each third buckle 149 is bent to form a hook to clasp with a corresponding one of the snaps 129 of the upper cover 12 . Therefore, the connection between the upper cover 12 and the lower cover 14 is strengthened. [0016] In assembly, the first buckles 128 of the upper cover 12 and the second buckles 148 of the lower cover 14 are clasped together. The receiving chamber 126 of the upper cover 12 and the space 18 inside the side wall 144 cooperatively receive the electronic elements 16 therein. In other words, one part of the electronic elements 16 is received in the space 18 , and the other part of the electronic elements 16 is received in the receiving chamber 126 of the upper cover 12 . Besides the trilobate shape, the lamp seat 10 can also substantially be a rectangle shape or a pentagonal shape. [0017] The housing 20 is annular, and defines a hole 21 through a center thereof. Alternatively, the housing 20 can be other configurations with the hole 21 defined therein, and the hole 21 is not limited in the center of the housing 20 . The lamp seat 10 is fastened to one side of the housing 20 . The protrusion 146 is inserted into the hole 21 , therefore, a thickness of the illumination device 100 can be decreased. Thus, the illumination device 100 has a low profile which is suitable to be a ceiling lamp for a room with a low height. In this embodiment, the housing 20 includes a base 22 and a cover 24 . The hole 21 is defined through both the base 22 and the cover 24 . [0018] The base 22 is an annular plate. A plurality of light sources i.e. light emitting diodes 222 are arranged on a bottom surface of the base 22 . The light emitting diodes 222 are arranged in two circles with different radius. In addition, the base 22 further defines a plurality of through holes 221 corresponding to the holes 141 of the bottom plate 142 . [0019] The cover 24 is located on the bottom surface of the base 22 with the light emitting diodes 222 facing toward the cover 24 . The cover 24 is made of transparent or translucency material. In addition, an inner surface of the cover 24 can be formed with microstructures to obtain a uniform light output for the illumination device 100 . The cover 24 includes an annular body 242 , and an outer flange 244 and an inner flange 246 extending from an outer edge and an inner edge of the body 242 , respectively. Three protruding platforms 248 extend upwardly from the body 242 , and are located between the inner flange 246 and the outer flange 244 . Each of the protruding platforms 248 defines two through holes 241 therein, corresponding to the two adjacent holes 141 at a same corner of the bottom plate 142 , for connecting the cover 24 , the base 22 and the lamp seat 10 together. When the cover 24 and the base 22 are assembled together, the inner flange 246 abuts against a bottom of the seat 22 . In this embodiment, the inner edge 244 and the outer edge 246 each define a plurality of recesses (not labeled) therein to facilitate airflow flowing through the cover 24 thereby to obtain a better heat dissipation of the light emitting diodes 222 . [0020] During assembly of the illumination device 100 , the electronic elements 16 are arranged in the space 18 inside the annular sidewall 144 of the lower cover 14 . The upper cover 12 is connected with the lower cover 14 with the receiving chamber 126 aligned and communicating with the space 18 , thereby to secure the electronic elements 16 between the upper cover 12 and the lower cover 14 . In this embodiment, the upper cover 12 and the lower cover 14 are connected together by the first buckles 128 clasping with the second buckles 148 . The cover 24 is attached to the bottom surface of the base 22 which have the light emitting diodes 222 mounted thereon. Rivets or screws are brought to extend through the through holes 241 , 221 and secure in the holes 141 to fix the cover 24 and the base 22 to the lamp seat 10 . [0021] In the present illumination device 100 , the protrusion 146 of the bottom plate 142 is configured to define a space 18 to receive the electronic elements 16 therein, and the protrusion 146 is inserted into the hole 21 of housing 20 . Therefore, the thickness of the illumination device 100 can be effectively decreased. Moreover, the use of LEDs 222 as the light source can effectively lower the consumed power while have the same brightness. [0022] It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

An illumination device includes a housing defining a hole therethrogh; a plurality of light sources each is a light emitting diode is disposed in the housing; a lamp seat is securely positioned at one side of the housing. The lamp seat comprises a protrusion configured to receive electronic elements therein. The protrusion of the lamp seat is inserted into the hole of the housing.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60/505,051, filed Sep. 22, 2003, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to apparatus and methods for conducting electrophoretic separation concurrently in a plurality of gels. More specifically, the present invention relates to apparatus and methods for performing multiple concurrent electrophoresis experiments with increased reproducibility among the gels through incorporation in the apparatus of improved passive thermal management features and improved electric field geometries. BACKGROUND OF THE INVENTION [0003] Gel electrophoresis is a common procedure for the separation of biological molecules, such as DNA, RNA, and proteins. In gel electrophoresis, the molecules are separated into bands according to the rate at which an imposed electric field causes them to migrate through a filtering gel. [0004] The basic apparatus used in this technique consists of a gel enclosed in a glass tube or sandwiched as a slab between glass or plastic plates. The gel has an open molecular network structure, defining pores which are saturated with an electrically conductive buffered solution of salt. These pores through the gel are large enough to admit passage of the migrating molecules. [0005] The gel is placed in contact with buffer solutions that make electrical contact between the gel and the cathode and anode of an electrical power supply. A sample containing the macromolecules and a tracking dye is placed on top of the gel. An electric potential is applied to the gel causing the sample macromolecules and tracking dye to migrate toward the bottom of the gel. The locations of the bands of separated macromolecules then are determined. By comparing the distance moved by particular bands in comparison to the tracking dye and macromolecules of known mobility, the mobility of sample macromolecules can be determined. Once the mobility of the sample macromolecules is determined, the size of the macromolecule can be calculated. [0006] As electrophoresis is used with increasing frequency in basic research, quality control, and in forensic and clinical diagnoses, it is increasingly important to be able to replicate all experimental conditions in multiple locations and labs. [0007] Among these experimental conditions, temperature is extremely important. [0008] The application of an electrical field to a gel results in the generation of heat. In general, higher temperatures increase the molecular kinetics, which results in faster migration of macromolecules through the separating gel. Further, a temperature increase affects the electrical conductivity of an electrolyte solution and may cause dissociation. [0009] Without temperature control or uniform electric field geometry, gels often exhibit uneven temperatures across the width of the gel resulting in “smile” or “frown” distortions. Smile distortions occur when bands migrate faster on the sides than in the middle of the gel; frown distortions occur when bands migrate faster in the middle than on the sides. [0010] Often, even a small temperature differential between the front and rear plates of the gel, if not mitigated, can cause the resulting bands to slant front to back, depending on the thickness of the gel and the heat transfer properties of the cassette plates. This challenge is particularly acute in test runs where the molecular migration rates exhibit overly temperature sensitive characteristics, as in DNA sequencing. For such runs, even a slight temperature differential, e.g. of 0.1° C., can cause the slanted bands to appear overlapping. [0011] Additionally, overheating of the gel (e.g., greater than 70° C.) can result in deleterious effects such as breakdown of the gel matrix resulting in poor resolution and band shape, alteration of the macromolecules including denaturation, alkylation or oxidation, and/or damage to the electrophoresis apparatus itself. [0012] In DNA sequencing, electrophoresis is conducted at high voltage (1200-3000 volts, 55 watts) to maintain a gel temperature of 45°-50° C. for maximum resolution of the denatured DNA strands. The temperature is controlled by the amount of power applied to the gel. Gels that run too cool (e.g., <40° C.) will have bands that are blurred, perhaps due to incomplete denaturation. Gels that run too warm (e.g., >60° C.) will lose resolution, perhaps due to the breakdown of the polyacrylamide. [0013] Precise temperature control is particularly critical in Single Stranded Conformational polymorphism (SSCP) analysis of DNA, where bands are extremely close together. The relative temperature differential between the front and the back surfaces of the gel therefore can have a critical effect on the resolution of the DNA bands. [0014] Various means have been used to attempt to control the temperature of the gel during electrophoresis. These include applying active or passive heat sinks to one side of the gel, regulating power to the gel, employing an enclosed heat exchanger internal to one of the buffer chambers, immersing the gels in a buffer-filled tank containing a heater/circulator, circulating the buffer through tubing immersed in an ice water bath, circulating the buffer through an external metal heat exchanger, and use of piezo thermo-electric heater/cooler controls. [0015] These means are limited in their ability to provide a compact apparatus for maintaining consistent and uniform thermal control across the area encompassing the front and back of the electrophoresis gels. The heat sinks exchange heat on only one side of the gel; the regulation of power to the gels cannot control regional hot spots and obviously limits the application of high wattage to the gels; the internal heat exchanger again exchanges heat on only one side of the gel and does not actively circulate buffer, resulting in vertical thermal gradients within the buffer chamber; immersing the gels in a heater tank is cumbersome, in that it requires a large volume of buffer and cannot cool the gels; and circulating the buffer through tubing immersed in an ice water bath is also cumbersome, and makes difficult fine control of temperature. [0016] Circulating the buffer through an external metal heat exchanger provides the most satisfactory temperature control. However, with the current electrophoresis systems, two pumps and heat exchangers would be required to assure uniformity of temperature and separation of the buffer fluids between the cathode and anode chambers. Further, with current electrophoresis systems, circulation of buffer within the chambers and across the gels is random and undirected, which may result in vertical and horizontal thermal gradients. [0017] Moreover, for electrophoretic separation, the first and second buffer solutions must be isolated from one another. To provide isolation, prior art electrophoresis systems use various methods, among which is use of a buffer core to which the gel cassettes are secured during electrophoresis. Previously known electrophoresis systems using a buffer core commonly use a buffer core subassembly containing clamps or latches that secure the gel cassettes to the buffer core. Once the cassettes are secured, the buffer core subassembly must then be loaded in the container prior to electrophoretic separation. For example, in prior art systems that use a clamping mechanism, a user generally must first construct a clamping subassembly that is then loaded into the container prior to performing electrophoresis. It would be desirable to provide a clamping device that is easier to use and does not require additional or moving parts. For example, there would be no need to configure, assemble, or adjust a clamp or other adjustable part. [0018] Various prior art patents have proposed apparatus and methods for simultaneously running multiple gels, but many potential problems exist, including ineffective temperature control on both sides of the gel cassettes, ineffective or inconvenient clamping of gel cassettes, and inability to apply a uniform electrical field to all of the gels. [0019] For example, U.S. Pat. No. 6,451,193 to Fernwood et al. (Fernwood) describes a single cell configured to receive multiple slab gels for conducting simultaneous electrophoresis experiments. The multitude of slab gels are supported vertically and parallel to one another while immersed in a buffer solution. A voltage is applied to all gels simultaneously while temperature control is achieved by circulating the buffer solution upward through the cell and cooling the circulating buffer solution with a tube heat exchanger positioned on the floor of the cell. [0020] There are several drawbacks associated with the electrophoresis system described in Fernwood, and in particular, the relative complexity of the buffer circulation and cooling mechanisms that are employed. For example, with respect to the cooling mechanism, circulation is effected by a coolant pump and chilling of the coolant prior to its return to the tank requires an external chilling or refrigeration unit. With respect to the buffer circulation mechanism, an external pump and an external circulation line are required. All of these external components make the device more cumbersome, and proper circulation of the buffer and coolant depend on proper and consistent operation of several external components. [0021] Another drawback associated with the device described in Fernwood is that the coolant is only circulated in tubing at the bottom of the tank, which may result in inconsistent cooling of a vertically upright gel cassette. Moreover, the coolant traverses the floor of the tank four times before further chilling of the coolant occurs. Therefore, coolant properties may vary at different locations that the coolant traverses the floor of the tank. [0022] In view of these drawbacks of previously known systems, it would be desirable to provide apparatus and methods for conducting multiple electrophoresis experiments that employ a passive cooling mechanism to avoid the need for complex, ineffective or cumbersome active cooling mechanisms. [0023] It also would be desirable to provide apparatus and methods for conducting multiple electrophoresis experiments that uses a simple clamping mechanism, without moving parts, to secure the gel cassettes in place and provide an effective seal between anode and cathode buffer solutions. [0024] It further would be desirable to provide apparatus and methods for conducting multiple electrophoresis experiments that employ one lower buffer chamber that is common to all gel cassettes in the container. [0025] It still further would be desirable to provide apparatus and methods for conducting multiple electrophoresis experiments that consistently control the temperature of the electrophoresis gels, regardless of the number of gels being run at any given time, particularly while maintaining a uniform electric field across the width of the gel SUMMARY OF THE INVENTION [0026] In view of the foregoing, the present invention provides an apparatus and methods for conducting multiple electrophoresis experiments that consistently control the temperature of the electrophoresis gels, regardless of the number of gels being run at any given time. This temperature control is achieved for electrophoretic separation concurrently in a plurality of gels, by using passive thermal management to avoid the need for complex, ineffective or cumbersome active cooling mechanisms. [0027] Furthermore, the apparatus and methods for conducting electrophoretic separation of the present invention provide homogeneous electric fields across the width of a gel. The temperature and electric field control of the present invention results in dye fronts that are within 10 mm from each other, within 5 mm from each other, or within 25%, 15%, 10%, or 5% of the length of a run. [0028] In yet another embodiment, the present invention provides an apparatus and methods for conducting electrophoretic separation concurrently in a plurality of gels using a simple clamping mechanism, without moving parts, to secure the gel cassettes in place and provide an effective seal between anode and cathode buffer solutions. [0029] In yet another embodiment, provided herein is an apparatus and methods for conducting multiple electrophoresis experiments that employ one lower buffer chamber that is common to all gel cassettes in the container. [0030] Accordingly, provided herein in a first embodiment, is an apparatus or a system for removably positioning one or more gel cassettes for electrophoresis, each gel cassette having a first face, a second face, and a gel disposed therebetween. The apparatus comprises a fluid-retaining container and means for apportioning the interior of the container into a plurality of volumes upon the positioning of one or more gel cassettes within the container. Each of the volumes is proportionate to the number of positioned cassette faces with which it is in fluid contact. Accordingly, the upper buffer volumes within buffer cores of the container are within 75% of each other, and lower buffer volumes per gel are within 75% of each other when the chamber has different numbers of gels, for example from 3 to 50 gels. [0031] In one series of embodiments, the apportioning means include means that are integral to the container and at least one means that is removably engageable within the container. [0032] In some embodiments, the apparatus further comprises means for concurrently establishing an electric field within the gel of each positioned cassette, wherein the field is substantially uniform among all of the positioned gels and substantially homogeneous across the width of each gel. Substantially uniform means that the field is within 10% among all positioned gels. In certain of these embodiments, the field establishing means include means integral to the container and at least one means removably engageable within the container. The combination of field uniformity and temperature regulation of apparatuses and methods of the present invention results in dye fronts that are within 15 mm from each other, within 10 mm from each other, within 5 mm from each other, or a traveled distance difference that is no more than 25%, 15%, 10%, 5%, 4%, 3%, or 2% of the length of a run at the end of an electrophoretic separation run. Therefore, for a 10% distance difference for a 65 mm gel length electrophoretic run, the dye fronts between different gels in the container at the end of the run are within 7 mm of each other. [0033] In certain embodiments, each of the apportioning means and the field-establishing means includes both means that are integral to the container and means that are removably engageable therein. In particularly useful embodiments, each one of the removably engageable field establishing means is integrated into one of the at least one removably engageable apportioning means to form a buffer core body. [0034] Typically, the apparatus is configured so that the plurality of apportioned volumes includes at least one first volume and a single second volume; the positioned cassettes render each of the at least one first volumes fluidly noncommunicating with the single second volume. In embodiments that include at least one buffer core, each of the at least one first volumes is internal to a buffer core. [0035] In various embodiments, the integral apportioning means include, for each buffer core potentially engageable within the container, a set of opposing first and second bulkheads. [0036] The opposing bulkheads of each set are typically configured to provide an inward pressure upon gel cassettes assembled to the buffer core body engaged therebetween. [0037] For example, in certain embodiments the bulkheads of each opposing set each comprises at least one upper protrusion, the protrusions configured to apply an inward pressure upon gel cassettes assembled to the buffer core engaged therebetween. In some embodiments, the bulkheads of each opposing set each further comprises at least one lower protrusion, the lower protrusions configured to apply an inward pressure upon gel cassettes assembled to the buffer core engaged therebetween. [0038] In embodiments particularly useful in establishing a uniform field across each of the gels within positioned cassettes, at least one of the opposing bulkheads of each set includes a plurality of lower wedge-shaped protrusions, the plurality of wedge-shaped protrusions collectively making discontinuous contact to the cassette assembled to the buffer core engaged therebetween. [0039] In typical embodiments, each of the bulkheads includes an aperture disposed through the bulkhead between its upper and lower protrusions. [0040] In some embodiments, the thickness of each of the end walls of the container is greater than that of each of the side walls of the container. [0041] In another aspect, the invention provides a container having a removable lid and a plurality of communicating chambers. Each of the plurality of chambers is configured to receive and engage a buffer core assembly. Each buffer core assembly preferably comprises a buffer core body and first and second cassettes securely coupled to front and back sides of the buffer core body. A space between the buffer core body and the first and second cassettes forms an upper buffer chamber, which is configured to receive a first buffer. [0042] Each chamber in the container preferably is formed using first and second opposing bulkheads. The first and second bulkheads each have a laterally protruding upper region, recessed central region, and an aperture disposed through the recessed central region. Further, at least one wedge-shaped member is disposed beneath the aperture in the first bulkhead, and at least one wedge-shaped member is disposed beneath the aperture in the second bulkhead. [0043] In application, each buffer core assembly is configured to be inserted between the first and second bulkheads of a desired chamber. As the buffer core assembly is inserted, the first and second gel cassettes contact the wedge-shaped members of the first and second bulkheads, respectively. This causes the first and second cassettes to be pressed inward towards the buffer core body. The pressure applied by the wedge-shaped members, along with the pressure applied by the laterally protruding upper regions of the bulkheads, provides an effective seal for the upper buffer chamber. Advantageously, since the wedge-shaped members are an integral component of the container, no moving clamping mechanisms are required to secure the gel cassettes in place and provide an effective seal between anode and cathode buffers. [0044] In accordance with one aspect of the present invention, a common lower buffer chamber is formed when a plurality of buffer core assemblies are placed in adjacent chambers of the container. Specifically, the common lower buffer chamber is formed as a space between a second cassette of a first buffer core assembly and a first cassette of a second buffer core assembly, a second cassette of a second buffer assembly and a first cassette of a third buffer assembly, and so forth. Therefore, when a second buffer is poured into the common lower buffer chamber, the second buffer may be placed in fluid communication with each of the gel cassettes, regardless of the number of cassettes employed. [0045] In a preferred method, each buffer core assembly to be used is inserted into a respective chamber of the container, then secured using the clamping force applied by the wedge-shaped members of the bulkheads, as described above. A predetermined volume of a first buffer then is poured into each upper buffer chamber, one at a time. In a next step, a corresponding predetermined volume of a second buffer is poured into the common lower buffer chamber at one location, then flows through various open spaces in the container to contact the outer surfaces of the gel cassettes in the container. In effect, the inner surfaces of each gel cassette are in contact with the first buffer in the upper buffer chamber, while the outer surfaces are in contact with the second buffer filling in the common lower buffer chamber. [0046] In a next step, the removable lid is placed on top of the container. The removable lid is coupled to first and second cables, which are adapted to be coupled to a power supply or charging means. The removable lid also is electrically coupled to negative and positive wires that are in electrical contact with each of the first and second buffers, respectively. [0047] When an electrical potential is applied across each of the negative and positive wires, an electric field on each of the gels in the container is developed. The electrical fields in the gels effect molecular separation of the electrophoresis samples in the gels The electrical fields in the gels effect molecular separation of the electrophoresis samples in the gels since the gels act as the only conductive path between the buffer solutions which are charged at opposite polarities. [0048] In accordance with one aspect of the present invention, passive thermal management techniques are used to control the temperatures of the gels in the cassettes. The passive thermal management techniques rely on the heat sinking capabilities of the first and second buffers to maintain a relatively equal temperature on the outer and inner plates of the cassette. According to passive thermal management provided herein, the temperature between upper buffers in separate buffer cores within a container at the end of an electrophoretic separation is within 25, 20, 15, 10, 5, 4, 3, 2, or 1° C. Furthermore, the temperature difference between an upper buffer and a lower buffer is within 25, 20, 15, 10, 5, 4, 3, 2, or 1° C. at the end of an electrophoretic separation performed using the apparatus or methods. Furthermore, according to passive thermal management provided herein, the temperature between gels at the end of an electrophoretic separation is within 25, 20, 15, 10, 5, 4, 3, 2, or 1° C. In certain illustrative examples, the temperature between upper buffer cores, between upper and lower buffers, and between gels is within 10° C. at the end of an electrophoretic separation. [0049] The heat sink principles that are used in conjunction with the present invention take into account several variables, including the specific heat of the buffers, the mass of the buffers added, the change in temperature, the current and voltage applied to the gels, and other variables. By knowing the voltage and current applied, knowing the time duration required to complete separation, knowing the specific heat of the buffer, and by calculating the mass of buffer to be added, the temperature increase of the gels can be kept below a predetermined threshold (for example, 60° C.). Furthermore, the apparatus and methods of the present invention ensure that the same temperature is maintained on the outer and inner surfaces of each gel cassette to avoid slanting of the migrating bands in a sample. The present invention also ensures that each gel in the apparatus is exposed to the same thermal environment as each of the other gels. [0050] If desired, a dam system may be used in conjunction with the apparatus of the present invention to run fewer than the maximum number of gels that the container can run. The dam interrupts flow to certain areas of the common lower buffer chamber, based on its placement in the container. For example, if the container has the capacity to run six gels simultaneously, but a user only wishes to run two gels, the dam is positioned such that flow in the lower buffer chamber is interrupted to the other four regions of the container. [0051] The dam system, which preferably is adapted to be coupled to the buffer core assembly in lieu of one of the cassettes, is configured to displace half the volume of an upper buffer chamber. Therefore, when an odd number of gels are being run, only one-half of buffer is poured into the upper buffer chamber, relative to when two cassettes are used in a buffer core assembly. Accordingly, a proportional amount of buffer is used, regardless of whether an even or odd number of gels are being run, thereby ensuring that the temperatures on the outer and inner surfaces of the cassettes will remain the same during electrophoresis. BRIEF DESCRIPTION OF THE DRAWINGS [0052] Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments, in which: [0053] FIGS. 1A-1B are, respectively, an exploded view of apparatus of the present invention and a sectional view of the container of FIG. 1A taken along longitudinal axis A-A; [0054] FIGS. 2A-2C are, respectively, perspective views of a buffer core assembly of the present invention with no cassettes, the buffer core assembly with one gel cassette coupled thereto, and the buffer core assembly with two gel cassettes coupled thereto; [0055] FIGS. 3A-3B are, respectively, front and side views of the buffer core assembly of FIGS. 2A-2C with no cassettes shown; [0056] FIG. 4A-4B are, respectively, a front view of a gel cassette and a cross sectional view of the gel cassette taken along line B-B of FIG. 4A ; [0057] FIGS. 5A-5B are, respectively, a perspective view of the apparatus of FIG. 1A in an assembled state and a sectional view of the apparatus in the assembled state, as taken along longitudinal axis A-A of FIG. 1A ; FIG. 5B illustrates for exemplary purposes the use of six gel cassettes without a dam; [0058] FIG. 6 is an exploded view showing a removable lid that may be used in conjunction with apparatus of the present invention; [0059] FIG. 7 is a perspective view showing the removable lid of FIG. 6 in an assembled state; [0060] FIGS. 8A-8B are, respectively, front and rear perspective views of a dam that may be used in conjunction with apparatus of the present invention; [0061] FIG. 9 is a perspective view depicting the dam of FIGS. 8A-8B coupled to a buffer core assembly; and [0062] FIGS. 10A-10C are sectional views illustrating the dam of FIGS. 8-9 being used to block flow to various regions of the container of the present invention. DETAILED DESCRIPTION [0063] Referring now to FIGS. 1A-1B , apparatus and methods for performing multiple electrophoresis experiments in accordance with the present invention are described. [0064] As shown in FIG. 1A , electrophoresis system 10 comprises container 20 having plurality of communicating chambers 30 a - 30 c , and further comprises plurality of buffer core assemblies 60 a - 60 c that correspond to respective chambers 30 a - 30 c . Although three chambers and three buffer core assemblies are illustratively depicted herein, greater or fewer chambers and buffer core assemblies may be employed, as will be apparent to one skilled in the art from the following detailed description. [0065] Container 20 preferably comprises first and second side walls 21 and 22 , closed bottom 23 , and first and second end walls 24 and 26 , as shown in FIG. 1A . Container 20 is open at the top for receiving buffer core assemblies 60 a - 60 c . Each buffer core assembly 60 a - 60 c preferably comprises buffer core body 61 and a pair of gel cassettes 80 a and 80 b , as will be described in greater detail hereinbelow with respect to FIGS. 2A-2C . [0066] Container 20 further comprises negative bus bar 44 and positive bus bar 45 . Negative and positive bus bars 44 and 45 preferably are disposed atop first and second side walls 21 and 22 , respectively, as shown in FIG. 1A . One or more screws 41 , or other means for attaching the bus bars, may be inserted into corresponding holes 42 to secure the bus bars to the side walls. [0067] Negative bus bar 44 is electrically coupled to pole conductor 48 , and further coupled to plurality of sockets 46 a - 46 c , which correspond to chambers 30 a - 30 c of container 20 . Positive bus bar 45 is electrically coupled to pole conductor 49 , and further coupled to plurality of sockets 47 a - 47 c , which correspond to chambers 30 a - 30 c , respectively, as depicted in FIG. 1A . [0068] In a particularly useful embodiment of the present invention, black and red polarity tabs 37 and 38 are affixed to container 20 on opposing lateral sides of the container, as depicted in FIG. 1A , to visually facilitate proper electrical attachments of buffer core assemblies 60 and lid 50 (see FIG. 6 ). As can be seen in FIG. 1A , each buffer core assembly 60 a - 60 c preferably comprises corresponding polarity tabs 37 and 38 to visually facilitate proper insertion of the buffer core assemblies into container 20 . [0069] Referring now to FIG. 1B , a sectional view of container 20 of FIG. 1A is illustrated to describe various internal features of electrophoresis system 10 . [0070] Container 20 has a plurality of chambers 30 a - 30 c , which are adapted to receive buffer core assemblies 60 a - 60 c , respectively. In a preferred embodiment, each chamber 30 is formed by first and second opposing bulkheads 110 a and 110 b . Each bulkhead 110 preferably comprises a laterally protruding (i.e., protruding along the X axis, see FIG. 1A ) upper region 112 and a recessed central region 111 having an aperture 113 disposed therethrough, as depicted in FIG. 1B . [0071] Each bulkhead 110 further preferably comprises at least one wedge-shaped member 115 disposed beneath apertures 113 . The wedge-shaped member preferably is manufactured using a suitable substantially noncompliant compound, such as plastic. [0072] First and second bulkheads 110 a and 110 b have substantially identical configurations, with the main exception that laterally protruding upper region 112 a of first bulkhead 110 a is situated slightly higher with respect to the side walls of container 20 than laterally protruding upper region 112 b of second bulkhead 110 b . The slight height differential facilitates insertion of buffer core assemblies 60 a - 60 c , because the buffer assemblies may be initially inserted at a slight vertical angle. The slight vertical angle allows the buffer core assemblies to slide into their respective chambers with little or no frictional interference, until each buffer core assembly contacts the wedge-shaped members at the bottom of the chamber. When each buffer core assembly contacts the wedge-shaped members, the wedge-shaped members force a vertical positioning of the buffer core assembly, as described in greater detail hereinbelow with respect to FIGS. 5A-5B , due to the clamping action between the two opposing lower wedges 115 and also between the two opposing upper protrusions 112 . [0073] Referring now to FIGS. 2-4 , preferred features of buffer core assembly 60 and gel cassettes 80 are described in greater detail. Each buffer core assembly 60 preferably comprises buffer core body 61 and a pair of gel cassettes 80 a and 80 b , as shown in FIG. 2C . [0074] Buffer core body 61 comprises upraised side walls 62 and 63 , and lower base 64 disposed between the side walls, as shown in FIG. 2A . Buffer core body 61 further comprises handle 68 and horizontal beam 67 disposed between upraised side walls 62 and 63 . First and second male conductors 102 and 103 are securely coupled to outer regions 68 a and 68 b of handle 68 , respectively, as shown in FIG. 3A . [0075] First male conductor 102 is coupled to wire 104 . A portion of wire 104 runs in groove 75 , which is formed in a lateral surface of side wall 62 , as shown in FIG. 3B . Wire 104 continues to run underneath buffer core body 61 via base channel 76 . Wire 104 preferably spans a substantial portion of base channel 76 , and is coupled to lower base 64 using a loop attachment to the underside of lower base 64 . In this manner, wire 104 may be exposed to a buffer that is disposed on the exterior of side wall 62 and underneath buffer core body 61 , as will be described in detail hereinbelow. [0076] Second male conductor 103 is coupled to wire 105 . Wire 105 runs through first aperture 69 a of horizontal beam 67 , and continues to extend through second aperture 69 b at the other end of beam 67 , as depicted in FIG. 3A . Wire 105 is coupled to horizontal beam 67 of buffer core body 61 , preferably using a loop attachment. [0077] Buffer core assembly 60 further comprises first and second recesses 73 a and 73 b , which are disposed in side walls 62 and 63 , respectively. Recesses 73 a and 73 b are disposed on front side 71 of buffer core body 61 , as shown in FIGS. 2A and 3A , and also are disposed in side walls 62 and 63 on back side 72 of buffer core body 61 . [0078] In application, first gel cassette 80 a is placed in the recesses that are disposed on back side 72 of buffer core body 61 , as depicted in FIG. 2B . Second gel cassette 80 b then is placed in recesses 73 a and 73 b on front side 71 of buffer core body 61 , as depicted in FIG. 2C . Each gel cassette rests upon base supports 79 , which are provided on front and back sides 71 and 72 of buffer core body 61 . [0079] Upper buffer chamber 130 is formed between first gel cassette 80 a , second gel cassette 80 b , and side walls 62 and 63 of buffer core body 61 , as depicted in FIG. 2C . Upper buffer chamber 130 is configured to receive a first buffer, such that the first buffer is placed into submerged contact with wire 105 to provide a charged buffer, as described in greater detail hereinbelow. [0080] Referring back to FIG. 2A , front and back sides 71 and 72 of buffer core body 61 preferably are provided with U-shaped grooves 77 , which are configured for fitting and holding one or more resilient strips 78 as a fluidic seal between gel cassettes 80 b and 80 a , respectively, and buffer core body 61 . The seal provided by resilient strips 78 ensures electrical and fluidic isolation of the first buffer disposed in upper chamber 130 with a second buffer that is disposed in a lower chamber, as described in detail hereinbelow. [0081] Referring now to FIGS. 4A-4B , features of gel cassettes 80 are described in greater detail. Each gel cassette 80 a and 80 b is substantially identical, and has an outer surface 81 a and an inner surface 81 b . It includes a pair of plates that are of thin wall construction. The plates are commonly referred to as the divider or divider plate 82 and retainer or retainer plate 84 . Retainer plate 84 is slightly shorter in height than the divider plate 82 . [0082] Divider 82 is affixed to peripheral ridge 86 along the lateral sides and the bottom periphery of retainer 84 to define an internal gel compartment 88 for holding an electrophoresis gel 90 . As shown in FIG. 4B , gel compartment 88 has a top or comb opening 92 at the top portion of the cassette for receiving a sample to be electrophoretically separated. [0083] Located along the lower portion of divider plate 82 and traversing the width of cassette 80 is a slot or opening 96 that opens gel compartment 88 to the exterior of cassette 80 and hence allows a direct electrical coupling with the charged buffer solution. [0084] Gel cassettes suitable for the present invention are known in the art. In a typical gel cassette, the gel is pre-filled within the internal gel compartment for ease of handling. Top opening 92 is closed with a comb (not shown), and slot 96 is masked closed with a removable tape (not shown). An example of the gel cassettes that are suitable for this application are the 12% Tris-glycine gels sold by INVITROGEN CORPORATION of Carlsbad, Calif., under catalog No. EC6005. Gel cassettes of similar types also are commercially available from other firms. [0085] Prior to use of cassette 80 , the comb (not shown) and the tape (not shown) disposed over top opening 92 and slot 96 , respectively, are removed. The sample to be analyzed is introduced into gel compartment 88 through comb opening 92 by an appropriate means, such as a pipette. The cassettes with their retainer plates 84 proximal to buffer core body 61 are held to rest within side recesses 73 and base supports 79 , as described hereinabove with respect to FIGS. 2A-2C . One or more buffer core assemblies 60 then are slidably inserted into a desired chamber 30 , i.e., one of chambers 30 a - 30 c , as depicted in FIG. 1A . [0086] Referring now to FIGS. 5A-5B , plurality of buffer core assemblies 60 a - 60 c are shown securely disposed in container 20 of FIGS. 1A-1B . During insertion of buffer core assemblies 60 a - 60 c into chambers 30 a - 30 c , laterally protruding upper regions 112 a and 112 b of opposing bulkheads 110 a and 110 b , respectively, apply an inward pressure against first and second cassettes 80 a and 80 b of each buffer core assembly. In effect, laterally protruding upper regions 112 a and 112 b serve to guide the buffer core assemblies into their respective chambers. [0087] As each buffer core assembly further is inserted into its respective chamber 30 , each gel cassette 80 is urged in an inward direction, i.e., towards buffer core body 61 , by a force applied by wedge-shaped members 115 , as shown in FIG. 5B . At this time, each gel cassette 80 is pressed firmly against resilient strips 78 (see FIGS. 2A-2C ). In particular, first cassette 80 a is pressed firmly against strips 78 by forces applied by wedge-shaped members 115 and laterally protruding upper region 112 a , while second cassette 80 is pressed firmly against strips 78 by forces applied by wedge-shaped members 115 and laterally protruding upper region 112 b. [0088] The forces applied by wedge-shaped members 115 against gel cassettes 80 a and 80 b ensure fluidic and electrical isolation between a second buffer present in common lower buffer chamber 140 and a first buffer present in each of the individual upper buffer chambers 130 a - 130 c . Fluidic and electrical isolation of first and second buffers reduces the risk of electrical grounding of the power supply or other sensitive instruments used in connection with the electrophoresis. [0089] At about the same time that each buffer core assembly is securely wedged into its chamber, male conductors 102 of buffer core assemblies 60 a - 60 c engage respective sockets 47 a - 47 c (see FIG. 1A ) of positive bus bar 45 . Similarly, male conductors 103 of buffer core assemblies 60 a - 60 c engage respective sockets 46 a - 46 c of negative bus bar 44 . [0090] It should be noted that both male conductors 102 and 103 are disposed on front portion 119 of buffer core body 61 , as depicted in FIG. 5A . This allows male conductors 102 to align with sockets 47 a - 47 c , and male conductors 103 to align with sockets 46 a - 46 c , but not vice versa. Therefore, each buffer core assembly 60 a - 60 c cannot be wedged into chambers 30 a - 30 c unless buffer core assemblies 60 a - 60 c are properly oriented, thereby ensuring proper electrical connections. As noted above, black and red polarity tabs 37 and 38 may be positioned on container 20 and buffer core assemblies 60 a - 60 c , as depicted, to further facilitate proper alignment of the buffer core assemblies by appropriate visual cues. [0091] Referring to FIG. 5B , when a plurality of buffer core assemblies 60 are securely placed in container 20 , a common lower buffer chamber 140 is formed. Specifically, common lower buffer chamber 140 is formed between second cassette 80 b of first buffer core assembly 60 a and first cassette 80 a of second buffer core assembly 60 b , as depicted in FIG. 5B . Common lower buffer chamber 140 also is formed between second cassette 80 b of second buffer core assembly 60 b and first cassette 80 a of third buffer core assembly 60 c . Further, common lower buffer chamber 140 is formed between first cassette 80 a of buffer core assembly 60 a and end wall 26 , and between outer cassette 80 b of buffer core assembly 60 c and end wall 24 , as depicted in FIG. 5B . [0092] In accordance with one aspect of the present invention, lower buffer chamber 140 allows a second buffer (not shown) to be placed in contact with each buffer core assembly 60 a - 60 c . When the second buffer is poured into any region of lower buffer chamber 140 , the second buffer will be distributed in a substantially equal fashion to the other regions of lower buffer chamber 140 . Specifically, the second buffer will flow through apertures 113 in bulkheads 110 a and 110 b (see FIG. 1B ), between wedge-shaped members 115 via channels 116 (see also FIG. 1B ), underneath lower buffer core base 64 via channel 74 (see FIG. 3A ), and around buffer core side walls 62 and 63 via side channels 66 (see FIG. 3A ). It should be noted that side walls 62 and 63 of buffer core body 61 preferably comprise spacers 65 a and 65 b , as shown in FIG. 3A , that are configured to contact a side wall of container 20 . Therefore, when buffer core assembly 60 is disposed in chamber 30 , channel 66 is formed between the side walls of the buffer core body and the side walls of the container to permit flow of the second buffer therebetween. [0093] Referring still to FIGS. 5A-5B , in application buffer core assemblies 60 a - 60 c are first secured within container 20 in the manner as described above. A predetermined volume of a first buffer (not shown) is then typically dispensed separately into each upper buffer chamber 130 a - 130 c above the comb openings 92 of the cassettes to establish fluid contact with gel 90 in the gel compartments. [0094] A corresponding, predetermined volume of a second buffer (not shown) then is introduced into lower buffer chamber 140 of container 20 . Pouring the predetermined volume of the second buffer into any region of lower buffer chamber 140 will cause the second buffer to be distributed substantially equally throughout chamber 140 . It should be noted that, in alternative embodiments, the second buffer may be added before the first buffer is added. [0095] Container 20 is configured such that the volumes between assemblies 60 a and 60 b , and between 60 b and 60 c are approximately twice as great as the volumes between cassette 80 a of assembly 60 a and end wall 26 , and between cassette 80 b of assembly 60 c and end wall 24 . Therefore, when the second buffer poured into lower buffer chamber 140 settles to a height h, approximately twice as much second buffer will settle between the adjacent buffer core assemblies as will settle between assembly 60 a and end wall 26 , and assembly 60 c and end wall 24 . [0096] For example, if 600 mL of the second buffer is poured into lower buffer chamber 140 , then after the buffer settles in container 20 , approximately 100 mL of the second buffer will settle between first cassette 80 a of assembly 60 a and end wall 26 , approximately 200 mL of the second buffer will settle between assemblies 60 a and 60 b , approximately 200 mL will settle between assemblies 60 b and 60 c , and approximately 100 mL will settle between second cassette 80 b of assembly 60 c and end wall 24 . Therefore, each outer surface of each cassette 80 will have approximately 100 mL of second buffer devoted as a heat sink disposed adjacent the outer surface. [0097] In a preferred embodiment of this aspect of the present invention, components of container 20 are dimensioned so that equal volumes of second and first buffers are devoted as heat sinks for the outer and inner surfaces 81 a and 81 b of each gel cassette 80 a . Therefore, as an example, if 600 mL of second buffer is poured into common lower buffer chamber 140 , as described above, then 200 mL of first buffer should be poured into each upper buffer chamber 60 a - 60 c . Since there are six gel cassettes in container 20 , and two cassettes per upper buffer chamber, then the inner surfaces of each of the six cassettes will have approximately 100 mL of first buffer devoted as a heat sink to the inner surfaces of the cassettes. [0098] As will be described in greater detail hereinbelow, the actual volumes of first and second buffers may be selected to ensure adequate heat sinking during electrophoresis to keep the temperature of gel 90 below a predetermined threshold. [0099] Referring now to FIG. 6 , removable lid 50 is positioned above the top portion of container 20 such that female electric plugs 56 and 58 are aligned with pole conductors 48 and 49 , respectively. As the lid is lowered onto container 20 , the female plugs are coupled with the pole conductors, thereby securing the lid to seat upon the top portion of container 20 . [0100] Asymmetric mating of removable lid 50 with container 20 preferably is employed to ensure a proper electrical connection. Specifically, in one embodiment, lid 50 will only fit onto container 20 when slot 53 can fit over short tab 25 , and slot 54 can fit over long tab 27 , as illustrated in FIG. 7 . Thus, as lid 50 is lowered, female electric plug 56 must be aligned with pole conductor 48 , and female electric plug 58 with pole conductor 49 , but not vice versa, to ensure proper electrical connections. In a preferred embodiment of the present invention, lid 50 is transparent to facilitate viewing and evaluation of the gels as they are being run, as described hereinbelow. [0101] After lid 50 is seated, conductor cables 57 and 59 are coupled to a power supply system or charging means for delivering an appropriate electrical potential to the electrophoresis system. In one embodiment of the present invention, cable 57 is coupled to the power supply to deliver a negative potential, and cable 59 to deliver a positive potential. In practice, the polarity of the electrical potential can be reversibly applied to the buffers, as a matter of choice. [0102] As a negative electrical potential is applied across pole conductor 48 , the electrical charge also is applied across each wire 105 (see FIG. 3A ), since each wire 105 is coupled to a male conductor 103 , and each male conductor 103 is electrically coupled to a socket 46 a - 46 c of negative bus bar 44 . Similarly, a positive electrical potential applied across pole conductor 49 also is applied across each wire 104 (see FIG. 3B ), since each wire 104 is coupled to a male conductor 102 , and each male conductor 102 is electrically coupled to a socket 47 a - 47 c of positive bus bar 45 . [0103] This in turn imposes an electrical potential difference between the first buffer, which is in contact with wire 105 , and the second buffer, which is in contact with wire 104 . Accordingly, the first buffer is negatively charged, while the second buffer is positively charged. [0104] As discussed hereinabove, gel 90 of cassettes 80 a and 80 b is in contact with the first buffers (in upper buffer chambers 130 a - 130 c ), and gel 90 is also in contact with the second buffer in common lower buffer chamber 140 . Therefore, the electrically charged buffers will result in an electrical field in gel 90 between top opening 92 and slot 96 to effect molecular separation of analytes in the sample. [0105] For optimally reproducible results among gels run concurrently, the electric field provided to each gel should be substantially identical; and for optimal separation within a gel, the electric field should be homogeneous across the gel (i.e., in the direction perpendicular to the direction of analyte migration). [0106] The apparatus of the present invention provides advantages with respect to both of these parameters in part by the design of container 20 , and in part by the placement of wires 105 , which span the length of the underside of buffer core body 61 (in direction y; as described hereinabove). [0107] In particular embodiments of container 20 , at least one of opposing bulkheads 112 a and 112 b of each set includes a plurality of lower wedge-shaped protrusions 115 , rather than a single wedge-shaped protrusion 115 that extends across the width of bulkhead 112 . The plurality of wedge-shaped protrusions 115 collectively make discontinuous contact with the cassette assembled to the buffer core engaged between the bulkheads, creating channels 116 (see FIG. 1B ). Channels 116 facilitate the reconvergence of the electric field at the level of cassette slot 96 , facilitating homogeneity across the gel. [0108] By spanning the underside of buffer core body 61 , wires 105 provide a uniform electric field across the gel cassettes in direction y. Moreover, wires 105 are situated within container 20 such that they provide a substantially uniform electric field to all gel cassettes. [0109] As mentioned hereinabove, heat is generated during electrophoretic molecular separation within gel 90 , thus creating uneven temperature gradients on the surfaces of the gel, as well as across its thickness. Such problem is effectively mitigated by controlling the surface temperature of the gel cassettes. [0110] Unlike previously-known apparatus and methods that actively circulate a coolant to control temperature, the present invention employs passive thermal management techniques to effect temperature control of the surface temperatures of gel cassettes 80 . In particular, the dimensions of the apparatus are configured to permit first and second buffers to serve as heat sinks during electrophoresis, when the first and second buffers are disposed in upper buffer chambers 130 a - 130 c and common lower buffer chamber 140 , respectively. This temperature control is achieved for electrophoretic separation concurrently in a plurality of gels, by using passive thermal management to avoid the need for complex, ineffective or cumbersome active cooling mechanisms. According to passive thermal management provided herein, the temperature between upper buffers in separate buffer cores within a container at the end of an electrophoretic separation is within 25, 20, 15, 10, 5, 4, 3, 2, or 1° C. Furthermore, the temperature difference between an upper buffer and a lower buffer is within 25, 20, 15, 10, 5, 4, 3, 2, or 1° C. at the end of an electrophoretic separation performed using the apparatus or methods provided herein. Since this is typically the maximum temperature difference, the difference during an electrophoresis run is not as great. In one illustrative example, the temperature difference between an upper buffer and a lower buffer, and the temperature between upper buffers of separate buffer cores in the same container, is within 10° C. at the end of an electrophoretic separation performed using the apparatus or methods provided herein. The temperature of the lower buffer can be measured between buffer cores, but in certain illustrative aspects is measured in front of, or in back of, the buffer cores. The front and back lower buffer regions are expected to have a greater temperature differential with the upper buffer than the lower buffer between buffer cores. [0111] The heat sink principles that are used to select dimensions of the apparatus of the present invention rely primarily on the heat transfer principle that the amount of heat added (“Q”) is equal to the product of specific heat of a substance (“c”), the mass of the substance(“m”) and the change in temperature (“ΔT”, or “T final −T initial ”) [0112] With respect to the present invention, the amount of heat added Q to the gels can be approximated by determining the product of the current (“i”) and voltage (“V”) that are applied. Therefore, since current i and voltage V are known quantities, the approximate amount of heat added Q to each of the gels can be determined. [0113] The approximate amount of heat added Q then is set equal to the product of specific heat of the buffer c, mass of the buffer m, and change in temperature ΔT (T final −T initial ). Since the specific heat of the buffer c is known, and the change in temperature is ascertainable (i.e., the initial temperature is known, and the final temperature is selected by the user), then the mass of the buffer to be added can be calculated. [0114] Therefore, a user can determine how much first and second buffer should be added to keep the temperature increase of gels 90 below a predetermined threshold (i.e., T final , such as 60° C.). Accordingly, in an other embodiment of the present invention, a method is provided for determining a volume of buffer to add to a cathode buffer reservoir or upper buffer reservoir, and the volume of buffer to add to an anode buffer reservoir, or lower buffer reservoir. The method includes selecting a target final temperature for a buffer and identifying an initial temperature for the buffer, and calculating a volume of buffer to add using a change in temperature between the target final temperature and the initial temperature and a specific heat of the buffer. [0115] In application, it is desirable to maintain approximately the same temperature on outer and inner surfaces 81 a and 81 b of cassettes 80 (+/−25, 20, 15, 10, or 5° C. during a run to avoid slanting of the migrating bands in a sample. In a preferred embodiment of the present invention, the specific heat of the first and second buffers are within 25%, 20%, 15%, 10%, 5%, substantially identical, or identical. Therefore, to maintain approximately the same temperature on both sides of the cassette, the volume of first buffer devoted as a heat sink to each inner surface 81 b is 50% to 150%, 75% to 125%, 85% to 115%, or 90% to 110% of the volume of second buffer devoted as a heat sink to each outer surface 81 a. [0116] Also, since heat is transferred to the effective heat sinks through faces of the cassettes, the inner and outer faces of the cassettes preferably are equal in area. Therefore, the heat flux out of one face is equal to the heat flux out of the other face, so long as the heat sink temperatures are equal. [0117] In a preferred embodiment of the present invention, end walls 24 and 26 of container 20 each comprise thickness t 1 , as depicted in FIG. 5B , which is greater than a structural thickness required to support the lid and contain the lower buffer in lower buffer chamber 140 . The enhanced thickness t 1 of end walls 24 and 26 serves to insulate the lower buffer in lower buffer chamber 140 from convective or radiant heat loss due to lower temperatures present outside of the container. [0118] In particular, enhanced thickness t 1 of end walls 24 and 26 serves to insulate the lower buffer present between end wall 26 and first cassette 80 a of buffer core assembly 60 a , and between end wall 24 and second cassette 80 b of buffer core assembly 60 c ; these end volumes of buffer have greater exposure to a wall of container 20 than do volumes defined further internal to container 20 . By appropriately increasing the thickness of the end walls, increasing their insulating capacity, the temperature of the lower buffer present in the vicinity of end walls 24 and 26 is within 25° C. to the temperature of the lower buffer present in interior regions of container 20 , thereby facilitating consistent runs for all gels in the container. [0119] Similarly, side walls 21 and 22 of container 20 may have a chosen thickness designed to reduce radiant or convective heat loss through the side walls. However, if desired, side walls 21 and 22 may have a reduced thickness that allows for some heat loss through the side walls. In such cases, the heat loss may be accounted for in thermal calculations to ensure that a desired buffer temperature is achieved. Because side walls 21 and 22 are common to all chambers (or apportioned volumes), the lower buffer present in lower buffer chamber 140 will still have a temperature throughout all regions of container 20 that is within 35° C., 25° C., 15° C., 10° C., or 5° C., thereby facilitating relatively consistent electrophoretic conditions regardless of the number of gels being run. [0120] As described hereinabove, container 20 is configured such that the volumes between assemblies 60 a and 60 b , and 60 b and 60 c are approximately twice as great as the volumes between cassette 80 a of assembly 60 a and end wall 26 , and cassette 80 b of assembly 60 c and end wall 24 . Therefore, when the second buffer poured into lower buffer chamber 140 settles to a height h, approximately twice as much second buffer volume will settle between the adjacent buffer core assemblies as will settle between assembly 60 a and end wall 26 , and assembly 60 c and end wall 24 . In the example described hereinabove, if 600 mL of the second buffer is poured into lower buffer chamber 140 , then after the buffer settles in container 20 , approximately 100 mL of the second buffer will settle between first cassette 80 a of assembly 60 a and end wall 26 , approximately 200 mL of the second buffer will settle between assemblies 60 a and 60 b , approximately 200 mL will settle between assemblies 60 b and 60 c , and approximately 100 mL will settle between second cassette 80 b of assembly 60 c and end wall 24 . Therefore, each outer surface 81 a of each cassette 80 will have approximately 100 mL of second buffer devoted as a heat sink disposed adjacent the outer surface. [0121] Since the apparatus of the present invention is configured to simultaneously run any number of gels, temperature control is scalable to the number of gels being run. Advantageously, by placing a dam into the system to seal off the unused regions, as described hereinbelow with respect to FIGS. 8-10 , a proportional volume of the second buffer can always be poured into lower buffer chamber 140 , regardless of the number of gels being run, to maintain a proper heat sink on the outer surface of each cassette being run. By “proportional volume” or “proportionate volume,” is meant that a volume of buffer is added to a buffer chamber such that the volume per gel is maintained within 75% of each other. In other words, if 100 milliliters of a lower buffer is used when two gels are included within an apparatus disclosed herein, then no less than 75 milliliters per gel of lower buffer would be used when three or more gels are present within the apparatus. In another aspect, a volume of buffer is added to a buffer chamber such that the volume per gel is maintained within 80%, 85%, 90%, 95%, or 99% of each other. In certain illustrative examples, when 6 gels are present within the apparatus, 640-700 milliliters of lower buffer is used, when 5 gels are present within the apparatus 550-610 milliliters of lower buffer are used, when 4 gels are present within the apparatus 480-520 milliliters of buffer are used, when 5 gels are present within the apparatus 340-380 milliliters of buffer are used. In another illustrative embodiment, between 75 and 150 milliliters of lower buffer are used per gel in the apparatus, between 100 and 135 milliliters, between 110 and 130 milliliters per gel, or in certain illustrative embodiments, between 112 and 125 milliliters per gel. In the illustrative examples discussed above, when 2 gels are present within a buffer core of the apparatus, between 225 and 275, for example 250 mLs of upper buffer are used. When 1 gel is present within a buffer core of the apparatus, between 150 and 180 mLs, for example 165 mLs, of upper buffer are used. [0122] In one example, if only two gels are being run, as described in FIG. 10B hereinbelow, then 225 mL of second buffer can be poured into lower buffer chamber 140 . If three gels are being run, then 360 mL of second buffer can be poured into lower buffer chamber 140 . Since the dam described hereinbelow prevents the flow of second buffer into the unused regions of the container, the level of the buffer will still rise to a level that is close to, or exactly at ‘h’. Therefore, the outer surface of each cassette will always have approximately 125 mL +/−25% of second buffer devoted as a heat sink, regardless of the number of gels being run. [0123] Referring now to FIGS. 8-10 , a dam system that may be used in conjunction with electrophoresis system 10 of FIGS. 1-7 is described. The dam system is used to control the volume of buffer used as a heat sink for the upper buffer chamber and lower buffer chamber. For example, when a dam is used between 30% and 80%, 40% and 75%, 40% and 70%, 50% and 70%, or 60% and 70% of the volume of the first buffer are poured into the upper buffer chamber in the presence versus absence of the dam. Container 20 can run a maximum number of gels 90 simultaneously. In the embodiments described hereinabove, container 20 is depicted as having the capability of running a maximum of six gels simultaneously, although it will be apparent to one skilled in the art that the maximum capacity may be greater or fewer than six gels. When a user wishes to run fewer gels than the maximum capacity, flow to other regions of the container must be interrupted to ensure that the proper volume of second buffer in lower buffer chamber 140 is devoted as a heat sink to each of the gel cassettes that are actually being used. [0124] Referring now to FIGS. 8A-8B , dam 200 , which may be employed to interrupt flow to unused regions of container 20 , preferably comprises central section 202 , protruding front section 204 , and rear section 206 . Dam 200 is configured to engage buffer core body 61 such that outer portion 203 of central section 202 is positioned in recesses 73 a and 73 b (see FIG. 3A ) of buffer core body 61 . Outer portion 203 is positioned against resilient strips 78 of FIG. 2A in a manner similar to the positioning of gel cassettes 80 a and 80 b , as described hereinabove. When outer portion 203 is positioned in recesses 73 a and 73 b , and rests upon base support 79 , protruding front section 204 extends approximately halfway into upper buffer chamber 230 of buffer core assembly 160 , as depicted in FIGS. 10A-10C hereinbelow. Therefore, upper buffer chamber 230 of buffer core assembly 160 has only half the volume as upper buffer chamber 130 of buffer core assembly 60 , which employs two cassettes. [0125] At this time, rear section 206 of dam 200 faces away from upper buffer chamber 230 . Rear section 206 preferably has a U-shaped slot 210 configured to receive and hold resilient strip 211 , as shown in FIG. 9 . As will be described in further detail hereinbelow, resilient strip 211 is configured to engage bulkhead 110 b such that flow to aperture 113 of the bulkhead is inhibited. [0126] Red and black polarity tabs 37 and 38 may be disposed on opposing lateral sides of dam 200 to facilitate coupling of dam 200 to buffer core body 61 in a proper orientation, as depicted in FIG. 9 . [0127] Referring now to FIGS. 10A-10C , illustrative uses of dam 200 in container 20 are described. In FIG. 10A , an arrangement is described whereby a user can run only one gel in container 20 . Buffer core assembly 160 has first gel cassette 80 a coupled to front side 71 of buffer core body 61 , and dam 200 coupled to back side 72 of buffer core body 61 . Buffer core assembly 160 is inserted into chamber 30 a of container 20 as described hereinabove. Specifically, buffer core assembly 160 is inserted between laterally protruding regions 112 a and 112 b of bulkheads 110 a and 110 b , respectively, and then urged downward. Wedge-shaped members 115 then urge cassette 80 a and dam 200 in an inward direction against resilient strips 78 , thereby securing buffer core assembly 160 within chamber 30 a of container 20 . [0128] In FIG. 10A , since only one gel is being run, dam 200 is employed to block flow to the rest of container 20 . In accordance with one aspect of the present invention, U-shaped strip 211 of dam 200 helps ensure that the second buffer in lower buffer chamber 140 does not flow into chambers 30 b and 30 c , which would compromise the heat sinking ability of the second buffer when only one gel is run. [0129] In a next step, a first buffer (not shown) then is poured into upper buffer chamber 230 a , and a second buffer (not shown) is poured into lower buffer chamber 140 . Since only one gel is being run in buffer core assembly 160 , only one-half of the volume of the first buffer is required in upper buffer chamber 230 a , relative to using two gel cassettes in the buffer core assembly. This is because front section 204 of dam 200 protrudes halfway into upper buffer chamber 230 a , as shown in FIB. 10 A. [0130] For example, when 100 mL of first buffer is poured into upper buffer chamber 230 a , 100 mL of second buffer is poured into lower buffer chamber 140 between the outer surface of cassette 80 a and end wall 26 . Therefore, 100 mL of first and second buffers are devoted as heat sinks for the inner and outer surfaces of cassette 80 a . Accordingly, the temperature on outer and inner surfaces 81 a and 81 b of cassette 80 a will be within 25° C., 15° C., 10° C., or 5° C. during electrophoresis. [0131] Protruding front section 204 of dam 200 preferably is configured to reduce radiant or convective heat loss through the dam. For example, a sufficient thickness associated with protruding front section 204 may be selected to reduce heat loss through the dam. This approach is similar to the that described hereinabove for reducing heat loss through end walls 24 and 26 of container 20 . Like the end walls, heat loss through dam 200 may be reduced by varying the thickness of section 204 to facilitate consistent temperature properties during electrophoresis runs, regardless of the number of gels being run. [0132] Referring now to FIG. 10B , an arrangement is described whereby a user can run only two gels in container 20 simultaneously. Buffer core assembly 60 c having first and second gel cassettes 80 a and 80 b is inserted into and secured within chamber 30 c of container 20 as described hereinabove. Then, buffer core assembly 160 having dam 200 is inserted into chamber 30 b , as shown in FIG. 10B . [0133] In the arrangement of FIG. 10B , U-shaped strip 211 of dam 200 is configured to block flow through aperture 113 of second bulkhead lob of chamber 30 b . Therefore, U-shaped strip 211 helps ensure that the second buffer in lower buffer chamber 140 does not flow into chambers 30 a and 30 b. [0134] A first buffer (not shown) is poured into upper buffer chamber 130 c , and a proportional amount of a second buffer (not shown) is poured into lower buffer chamber 140 . For example, when 200 mL of first buffer is poured into upper buffer chamber 130 c , and 200 mL of second buffer is poured into lower buffer chamber 140 , then 100 mL of first buffer is devoted as a heat sink for each of the inner surfaces of cassettes 80 a and 80 b , and 100 mL of second buffer is devoted as a heat sink for each of the outer surfaces of cassettes 80 a and 80 b . Accordingly, the temperature on the outer and inner surfaces 81 a and 81 b of cassette 80 a will be approximately the same, assuming the specific heat of the buffers are substantially identical. [0135] Referring now to FIG. 10C ., an arrangement is described whereby a user can run only three gels in container 20 simultaneously. Buffer core assembly 60 a having first and second gel cassettes 80 a and 80 b is inserted into and secured within chamber 30 a of container 20 , as described hereinabove. Then, buffer core assembly 160 having first cassette 80 a and dam 200 is inserted into chamber 30 b , as shown in FIG. 10C . [0136] In the arrangement shown in FIG. 10C , U-shaped strip 211 of dam 200 is configured to block flow through aperture 113 of second bulkhead 110 b of chamber 30 b . Therefore, U-shaped strip 211 helps ensure that the second buffer in lower buffer chamber 140 does not flow into chamber 30 c. [0137] A first buffer (not shown) is poured into upper buffer chamber 130 a . Then, one-half of the first buffer volume poured into chamber 130 a is poured into chamber 230 b . A proportional amount of a second buffer (not shown) then is poured into one of the regions of lower buffer chamber 140 shown in FIG. 10C . For example, when 200 mL of first buffer is poured into upper buffer chamber 130 a , then 100 mL of first buffer is poured into upper buffer chamber 230 b , and 300 mL of second buffer is poured into common lower buffer chamber 140 . In effect, both outer and inner surfaces 81 a and 81 b of the three cassettes being run will have 100 mL of second and first buffer, respectively, devoted as a heat sink to the outer and inner cassette surfaces. Accordingly, the temperature on the outer and inner surfaces 81 a and 81 b of each cassette will be the same, assuming the specific heat of the buffers are substantially identical. [0138] As will be apparent to one skilled in the art, four or five gels also may be run simultaneously by further varying the location of dam 200 within container 20 and varying the number of cassettes employed. Moreover, it will be apparent to one skilled in the art that greater than six gels may be run simultaneously by providing additional chambers 30 . Advantageously, dam 200 can block flow to regions of container 20 so that any number of gels can be run simultaneously. The user simply needs to adjust the volume of first and second buffers in a proportional manner, as illustratively described hereinabove, to maintain proper thermal management in the system. [0139] All patents and publications cited in this specification are herein incorporated by reference as if each had specifically and individually been incorporated by reference herein. Although the foregoing invention has been described in some detail by way of illustration and example, it will be readily apparent to those of ordinary skill in the art, in light of the teachings herein, that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims, which, along with their full range of equivalents, alone define the scope of invention.

Apparatus and methods for conducting electrophoretic separation concurrently in a plurality of gels with improved reproducibility among the gels.

INCORPORATION BY REFERENCE [0001] This application claims priority based on a Japanese patent application, No. 2011-218854 filed on Oct. 3, 2011, the entire contents of which are incorporated herein by reference. BACKGROUND [0002] The disclosed subject relates to an access control method for controlling the permission of information display, an information display device using the method, and an information display system. [0003] Information confidentiality must be maintained when we carry a mobile terminal with confidential information, such as customer information, stored therein. Maintaining confidentiality is to establish the state in which only those authorized to access information are allowed to access the information. This means that, if the mobile terminal is stolen, some means is required to prevent a third party from browsing the confidential information. One of the methods for preventing a third party from browsing confidential information is to authenticate a person who accesses the information for browsing. [0004] One of the authentication methods is to authenticate a person using a pre-defined character string information (password, access code, etc.,). An example of such a method is disclosed in U.S. Pat. No. 7,401,229. According to the method, an encrypted access code is stored in a transportable and nonvolatile memory. When a user actually carries the nonvolatile memory to plug it into a computer remotely accessing, remote access is established between the computer to be remotely accessed and the computer remotely accessing. [0005] Another authentication method is a method that uses position information for authentication. An example is disclosed in paragraph 0007 in JP-A-2011-118635. According to this method, security is provided using position information (e.g., a place fixed for meeting or a place fixed for arrangement), directly related to a person, as a key (authentication condition). SUMMARY [0006] The method disclosed in U.S. Pat. No. 7,401,229, in which an encrypted access code stored in a nonvolatile memory is used for authentication, requires that an external device, a nonvolatile memory in this case, be coupled. The problem with this method is that the coupling of an external device to a mobile terminal leads to an increase in the cost and that the need to couple an external device each time the user browses customer information is cumbersome. [0007] The problem with the authentication method using position information, such as the one disclosed in JP-A-2011-118635, is that the method depends largely on the validity of position information but the position information is easily forged. For example, when the position information (latitude, longitude) is identified using a radio wave from a satellite positioning system such as GPS, the position information may be forged by transmitting a forged radio wave. Another forging method is to replace the software, which calculates position information based on a received radio wave, with counterfeit software, resulting in a situation that the user unknowingly uses forged position information. [0008] In view of the foregoing, there is a need for a secure, easy-to-use authentication method. [0009] For use on an information display device, such as a mobile terminal, that accesses (for example, browses) confidential information (for example, customer information) during movement, this specification discloses an access control method for controlling access permission based on the movement route of the terminal position, an information display device that uses the method, and an information display system. [0010] The disclosed access control method, information display device that uses the method, and information display system are characterized as follows. An encryption key is generated on a management terminal based on a planned route, and information is encrypted using the encryption key. When the user accesses the information via the information display device, a decryption key is generated based on the actual movement route (actual route) that is regularly acquired, and the encrypted information is decrypted using the decryption key. That is, the encrypted information can be decrypted if the planned route and the actual route match. [0011] For example, one specific mode that is disclosed is [0012] an access control method for accessing information at a place, to which a user will move, using a portable information display device, the access control method comprising the steps of: [0013] identifying identifiers of planned waypoints during a move to a destination and an identifier of the destination, the destination being a place where the information will be accessed; [0014] creating a planned route of the information display device, the planned route represented as a sequence of the identifiers of the planned waypoints and the identifier of the destination; [0015] generating an encryption key based on the created planned route; [0016] encrypting the information, which will be accessed, using the generated encryption key; [0017] repeatedly acquiring position information on the information display device during the move; [0018] identifying identifiers of waypoints and an identifier of a current position based on the acquired position information; [0019] identifying an actual route of the information display device, the actual route represented by a sequence of the identifiers of the waypoints and the identifier of the destination; [0020] generating a decryption key based on the identified actual route; and [0021] decrypting the encrypted information using the generated decryption key and, if the decryption is successful, permitting the information display device to access the information. [0022] In another preferable mode that is disclosed, a partial-area-based actual route is used as the actual route. [0023] In still another preferable mode that is disclosed, an actual route using a partial area, corresponding to one or more of a origin, a destination, and intersections on the route from the origin to the destination, is used. [0024] In still another preferable mode that is disclosed, a road-link-based actual route is used as the actual route. [0025] In still another preferable mode that is disclosed, a partial route that loops is deleted from the actual route for correcting the actual route and, after that, the decryption key is generated. [0026] The disclosure allows the user to take out information while maintaining information confidentiality. [0027] These and other benefits are described throughout the present specification. A further understanding of the nature and advantages of the invention may be realized by reference to the remaining portions of the specification and the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0028] FIG. 1 is a diagram showing an example of the system configuration in this embodiment. [0029] FIG. 2 is a diagram showing an example of the hardware configuration in this embodiment. [0030] FIG. 3 is a diagram showing an example of the table configuration of a route information management unit in this embodiment. [0031] FIG. 4 is a diagram showing an example of the table configuration of a customer information management unit in this embodiment. [0032] FIG. 5 is a diagram showing an example of the table configuration of a position information history management unit in this embodiment. [0033] FIG. 6 is a diagram showing an example of the table configuration of a partial area information management unit in this embodiment. [0034] FIG. 7 is a diagram showing an example of the table configuration of a warning information management unit in this embodiment. [0035] FIG. 8 is a flowchart showing an example of the take-out information creation processing in this embodiment. [0036] FIG. 9 is a flowchart showing an example of the customer information encryption processing in this embodiment. [0037] FIG. 10 is a flowchart showing an example of the information display processing in this embodiment. [0038] FIG. 11 is a flowchart showing an example of the update processing for customer information display permission in this embodiment. [0039] FIG. 12 is a diagram showing an example of the image of a planned route in this embodiment. [0040] FIG. 13 is a diagram showing an example of the image of the notification screen that notifies the customer information display permission in this embodiment. [0041] FIG. 14 is a diagram showing an example of the image of a warning notification in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS [0042] An embodiment of the present invention will be described in detail with reference to the drawings. In the description of the embodiment below, customer information is used as an example of confidential information and browsing is assumed as an example of access. [0043] FIG. 1 is a diagram showing the configuration of a system in this embodiment. This system includes a management terminal 101 and an information display device 110 . The management terminal 101 and the information display device 110 are coupled over a network 130 for transmitting and receiving information. The network 130 may be a wired link or a radio link. [0044] The management terminal 101 includes the following functional units: route creation unit 102 , route information (inf) management (mng) unit 103 , partial area information creation unit 104 , take-out information creation unit 105 , encryption unit 106 , customer information management unit 107 , and warning information creation unit 108 . These processing units and the processing described below are implemented by executing the programs on the CPU included in the management terminal 101 . [0045] The route creation unit 102 creates a planned route, along which to travel, based on the interaction processing with the user, and records the created planned route in the route information management unit 103 . In this case, multiple routes from the origin to the destination may be registered. For example, when two routes from the origin to the destination are registered, the customer information may be browsed via any one of the routes. [0046] The route information management unit 103 stores not only a route, along which to travel, that is created by the route creation unit 102 but also a route with a past date. For the information on a past route, the route information management unit 103 collects the movement result from a position information history management unit 111 in the information display device 110 and, if the user traveled along a route different from the planned route, updates the information in the route information management unit 103 with the movement result. [0047] The partial area information creation unit 104 creates partial area information based on a route registered in the route information management unit 103 , and the take-out information creation unit 105 creates a planned route using the registered route and the partial area information. The encryption unit 106 encrypts the customer information using an encryption key created based on the planned route, and the warning information creation unit 108 creates warning information based on the planned route. If multiple routes are registered for the same origin and the destination, a planned route is created for each route. If multiple planned routes are created, the encryption unit 106 encrypts the customer information using different encryption keys, once for each planned route. [0048] The information display device 110 includes the following functional units: position information history management unit 111 , map information management unit 112 , position information management unit 113 , sensor information acquisition unit 114 , information access control unit 115 , decryption unit 116 , encrypted information management unit 117 , movement monitoring unit 118 , partial area information management unit 119 , and warning information management unit 120 . These processing units and the processing described below are implemented by executing the programs on the CPU included in the information display device 110 . [0049] The position information management unit 113 regularly acquires the sensor information from a position information sensor 125 , an acceleration sensor 126 , and a gyro sensor 127 via the sensor information acquisition unit 114 , wherein the position sensor 125 receives a radio wave from a satellite positioning system, such as GPS, for identifying the position. The position information management unit 113 identifies the current position on the map using the map information, managed by the map information management unit 112 , and the acquired sensor information and then registers the current position in the position information history management unit 111 . The position information history management unit 111 stores not only today's position information history but also past position information including yesterday's information. The upper limit of data that can be stored is pre-defined and, when the amount of the position information history reaches a predetermined amount, the position information history management unit 111 deletes the information beginning with the oldest information. The upper limit may be fixed or variable. The upper limit may be set using an absolute value (for example, 100 MB), a relative value for the capacity of the storage device (for example, 30%), or an absolute value for the remaining amount of the storage device (for example, history may be stored until the remaining amount becomes 500 MB). [0050] The movement monitoring unit 118 regularly acquires the current position from the position information management unit 113 and, as the current position moves, determines if the user moves to a different partial area or if a warning is required for the user. The information access control unit 115 manages the movement history as an actual route, and the decryption unit 116 decrypts the customer information based on the actual route. [0051] The user creates a route using the management terminal 101 in the office. Next, the user downloads the partial area information created based on the created route, encrypted customer information, and warning information into the information display device 110 via the network 130 . The downloaded partial area information is saved in the partial area information management unit 119 , the encrypted customer information is saved in the encrypted information management unit 117 , and the warning information is saved in the warning information management unit 120 . After downloading the information, the user rides in a car with the information display device 110 , sets it in the car, and starts traveling. [0052] FIG. 2 is a diagram showing the hardware configuration of the information display device 110 . The information display device 110 includes a CPU (processor) 201 , a RAM 202 , a ROM 203 , an external storage device 204 , a sensor interface 205 , and a device interface 206 . The external storage device 204 may be an HDD (hard disk drive), an SSD (flash memory drive), or an optical disc (DVD) device. The sensor interface 205 is coupled to the position sensor 125 , acceleration sensor 126 , and gyro sensor 127 . The device interface 206 is coupled to a display 128 and a speaker 129 . [0053] The programs of the position information management unit 113 , sensor information acquisition unit 114 , information access control unit 115 , decryption unit 116 , and movement monitoring unit 118 and the data of the position information history management unit 111 , map information management unit 112 , encrypted information management unit 117 , partial area information management unit 119 , and warning information management unit 120 , which are shown in FIG. 1 , are stored in the external storage device 204 . When the information display device 110 is powered on, these programs and data are loaded from the external storage device 204 into the RAM 202 and the programs are executed. In this case, the loader program, which loads the programs and data into the RAM 202 , is stored in the ROM 203 . [0054] FIG. 3 is a diagram showing the table configuration of the route information management unit 103 in the management terminal 101 . This table, provided for managing the routes the user visits, is composed of the following columns: user ID 301 , date 302 , order 303 , origin 304 , destination 305 , and road link 306 . The user ID 301 is information for identifying a user. The date 302 represents the date on which the user will move or moved along the route, indicating that the user moves from the place specified by the origin 304 to the place specified by the destination 305 on the date specified by the date 302 . The road link 306 indicates the route from the origin 304 to the destination 305 using a road link sequence. For example, the road link 306 indicates that the user moves from P 1 to P 2 via the road link L 11 →L 12 →L 13 → . . . . In this table, two types of routes are saved: planned route and actual route. The planned route is a route the user will visit in future, and the actual route is a route the user already visited. The date 302 of the planned route is a future data, and the date 302 of the actual route is a past date. [0055] FIG. 4 is a diagram showing the table configuration of the customer information management unit 107 in the management terminal 101 . This table, provided for managing customer information, is composed of the following columns: destination 401 and customer information file 402 . The destination 401 corresponds to the destination 305 in FIG. 3 . The customer information file 402 represents the location of the customer information file corresponding to the destination 401 . For example, the customer information to be browsed at the destination P 2 is stored in the file “C:/data/info1.data”. [0056] FIG. 5 is a diagram showing the table configuration of the position information history management unit 111 in the information display device 110 . This table is composed of the following columns: date/time 501 , coordinate 502 , road link 503 , and destination arrival flag 504 . The coordinate 502 , which indicates the information that identifies a position, may be the latitude/longitude or the relative coordinates with a particular point as the origin. The road link 503 indicates the ID of the road link along which the user travels at that time. For example, the first entry indicates that the user is traveling along the road link “L 11 ” at 14:26:30 on 2011 Jul. 18 and that the coordinates at that time are “X 1 ,Y 1 ”. The destination arrival flag 504 indicates whether or not the user has arrived at a destination at the time indicated by the date/time 501 . For example, the example in the figure indicates that the user has already arrived at the destination at 14:26:30 on 2011 Jul. 18. It is determined that the user has arrived at the destination and therefore the destination arrival flag is set to “1” either when the user presses the “arrival” button displayed on the display 128 or when the customer information is decrypted successfully and the user browses the content of the customer information. [0057] FIG. 6 is a diagram showing the table configuration of the partial area information management unit 119 in the information display device 110 . This table is composed of the following columns: partial area ID 601 and partial area 602 . The partial area 602 is information for identifying a partial area of an area divided into a grid. The partial area 602 , which is represented by a rectangular area, is specified by the two vertices. For example, “M 1 ” is the partial area ID of a rectangular area whose vertices on the diagonal line are “X 1 ,Y 1 ” and “X 2 ,Y 2 ”. [0058] FIG. 7 is a diagram showing the table configuration of the warning information management unit 120 in the information display device 110 . This table, provided for managing information for notifying a warning to the user, is composed of the following columns: before-movement partial area ID 701 and after-movement partial area ID 702 . An entry in this table indicates a warning that is issued when the user moves from the before-movement partial area ID 701 to the after-movement partial area ID 702 . For example, a warning is issued when the user's position moves from “M 1 ” to “M 2 ”. The before-movement partial area ID 701 and the after-movement partial area ID 702 correspond to the partial area ID 601 in FIG. 6 , and the partial area 602 is defined in FIG. 6 . [0059] FIG. 8 is a flowchart showing the take-out information creation processing performed by the take-out information creation unit 105 in the management terminal 101 . The user specifies the “user ID” and the “target date/time” to create the take-out information. [0060] In step 801 , the take-out information creation unit 105 first searches the route information management unit 103 for route information using the specified user ID and the date/time as the key. The take-out information creation unit 105 searches for multiple pieces of route information, for example, the route from the origin P 1 to the destination P 2 , the route from the origin P 2 to the destination P 3 , and so on. If the route creation unit 102 has registered multiple routes from a origin to a destination, the take-out information creation unit 105 searches for multiple routes from the same origin to the same destination. For example, multiple routes from the origin P 1 to the destination P 2 are searched for. Next, the take-out information creation unit 105 acquires a list of destinations from the multiple acquired routes and determines the partial area size so that the destinations are included in different partial areas, one in each partial area. Note that a partial area is a rectangular area created by dividing an area into a grid. First, a partial area that is used as the base partial area is defined in advance. The take-out information creation unit 105 performs calculation to find a partial area to which each destination belongs and, if two or more destinations belong to the same partial area, divides the partial area into four (into two in vertical direction and into two in horizontal direction) to narrow the range of one partial area. The take-out information creation unit 105 repeatedly divides the partial areas until no multiple destinations belong to the same partial area. The size of the base partial area may be set in advance arbitrarily; instead of this, the primary geographic division (about 80 km squares), secondary geographic division (about 10 km squares), or tertiary geographic division (about 1 km squares), which is defined by Japanese Industrial Standards, may also be used. [0061] Next, to identify the destination of the processing target, the take-out information creation unit 105 selects one route from the multiple routes searched for in step 801 (step 802 ) and acquires the road link 306 of the selected path. Based on the acquired road link 306 and the partial area information calculated in step 801 , the take-out information creation unit 105 identifies a planned route from the origin to the destination (step 803 ). [0062] Note that the planned route may be a partial-area-based planned route, a road-link-based planned route, or a destination-based planned route. The partial-area-based planned route is determined as follows. When the road link sequence of the route is L 1 →L 2 →L 3 →L 4 and when the partial area corresponding to the road link L 1 is M 1 , the partial area corresponding to the road link L 2 is M 2 , the partial area corresponding to the road link L 3 is M 2 , and the partial area corresponding to the road link L 4 is M 3 , then the partial-area-based planned route is M 1 →M 2 →M 3 . [0063] For the road-link-based planned route, the road link 306 acquired in step 801 is used directly as the planned route based on a road link. The destination-based planned route is determined as follows. When there is a route via which the user visits the destinations in the order P 1 →P 2 →P 3 and when the partial area corresponding to P 1 is M 1 , the partial area corresponding to P 2 is M 2 , and the partial area corresponding to P 3 is M 3 , then the destination-based planned route is M 1 →M 2 →M 3 . Note that the visiting route P 1 →P 2 →P 3 is registered in the route information management unit 103 as two routes, P 1 →P 2 and P 2 →P 3 . Although, for a destination-based planned route, an array of the partial areas corresponding to the coordinates of the destination is used using the destination as the base point, an array of partial areas corresponding to the destination and the intersections may also be used using not only the destination but also the intersections on the way as the base point. [0064] As the intersections that is used, all left-turn and right-turn intersections may be selected, a part of left-turn and right-turn intersections may be selected randomly, or predetermined particular intersections may be selected. A partial-area-based planned route, a road-link-based planned route, and a destination-based planned route will be described more in detail also in FIG. 12 using an illustration example. [0065] A planned route, from which a loop portion is deleted, is created. Because whether a loop portion is a correct route or a return route after a mistake cannot be determined, the loop portion is excluded from the target of the planned route. For example, for a planned route in which the user moves partial areas “M 1 →M 2 →M 3 →M 2 →M 4 ”, the planned route is changed to “M 1 →M 2 →M 4 ” by deleting the loop portion “M 2 →M 3 →M 2 ”. Doing so produces two planned routes; one is the original planned route from which the loop portion is not deleted and the other is the planned route from which the loop portion is deleted. The planned route from which the loop portion is not deleted is used for the generation of warning information (step 805 ), and the planned route from which the loop portion is deleted is used for customer information encryption (step 804 ). [0066] Next, the take-out information creation unit 105 encrypts the customer information, which will be browsed at the destination, based on the planned route which was acquired in step 803 and from which the loop portion is delete (step 804 ). The take-out information creation unit 105 identifies the customer information to be encrypted by searching the customer information management unit 107 using the destination, identified in step 802 as the key. The detail of the customer information encryption processing will be described later with reference to FIG. 9 . [0067] For stronger encryption, it is required that the size of the planned route, specified as the input, be equal to or longer than a predetermined size and that the size be pre-defined in advance according to the security requirement. That is, the predetermined number or more partial areas or road links must be specified as the planned route. If the number of partial areas or the number of links of the identified planned route from the origin to the destination is insufficient, one or more preceding planned routes are used to extend the route. If multiple routes are registered when using preceding planned routes, which route to use is determined according to the priority that is set at registration time. [0068] For example, consider the example in which the customer information on P 3 is encrypted. In this example, assume that the planned route P 1 →P 2 from which the loop portion is deleted is “M 1 →M 2 →M 3 ”, that the planned route P 2 →P 3 from which the loop portion is deleted is “M 3 →M 4 →M 5 ”, and that the number of partial areas required for encryption is “4”. In this case, because there are only three partial areas in the planned route “M 3 →M 4 →M 5 ” for P 2 →P 3 , the planned route for P 2 is consolidated to create the planned route “M 1 →M 2 →M 3 →M 4 →M 5 ”. After that, the four partial areas closest to the destination are selected to create the planned route “M 2 →M 3 →M 4 →M 5 ”. [0069] As described above, the information amount of a single planned route, if insufficient, is increased by using a past planned route to extend the planned route. A past planned route of different date may also be used. For example, if the information on the planned route P 1 →P 2 on 2011 Jul. 21 is insufficient and if there is no preceding route before P 1 on 2011 Jul. 22, the planned route is extended to a past planned route and the planned route P 10 →P 1 on preceding date 2011 Jul. 21 is used. [0070] Next, the take-out information creation unit 105 generates warning information based on the planned route which is acquired in step 803 and from which a loop portion is not deleted (step 805 ). The warning information is generated to alert the user to the condition in which the user has departed from the route. The generated warning information is downloaded to the information display device 110 to give a warning to the user when the user has departed from the predetermined route. A warning is issued when the user moves out of the planned route which is acquired in step 803 and from which a loop portion is not deleted. [0071] For a partial-area-based planned route, a warning is issued if a partial area array is acquired in step 803 as the planned route from which a loop portion is not deleted and if a transition occurs to a partial area not defined in this partial area array. For example, if the partial area array is M 1 →M 2 and the partial areas surrounding M 1 (up and down, left and right) are {M 2 , M 3 , M 4 , M 5 }, warning information is generated if a transition other than the transition M 1 →M 2 occurs (that is, transitions M 1 →M 3 , M 1 →M 4 , and M 1 →M 5 ). In the warning information, a before-transition partial area is a partial area on the planned route and an after-transition partial area is a partial area out of the planned route. For a road-link-based planned route, a warning is issued if a road link sequence is acquired in step 803 as the planned route and if a transition occurs between road links not defined in this road link sequence. [0072] For example, if the road link sequence is L 1 →L 2 and if the end point of L 1 is an intersection and a transition to {L 2 , L 3 , L 4 } may occur, warning information is generated if a transition other than the transition L 1 →L 2 occurs (that is, transitions L 1 →L 3 and L 1 →L 4 ). In the warning information, a before-transition road link is a road link on the planned route and an after-transition road link is a road link out of the planned route. For a destination-based planned route, the route to the designation may be determined arbitrarily and therefore no warning information is generated. [0073] If the encryption of customer information on multiple destinations, searched for in step 801 , is completed (Yes in step 806 ), the processing is terminated. If there is customer information not yet encrypted (No in step 806 ), control is passed back to step 802 . [0074] FIG. 9 is a detailed flowchart showing the customer information encryption processing (step 804 in FIG. 8 ) performed by the take-out information creation unit 105 . First, in step 901 , the take-out information creation unit 105 generates a random number used for encryption key generation. For the encryption, the common key encryption algorithm is used in which the same key is used for the encryption key and the decryption key. Therefore, the random number generation method is used that generates the same random number for decryption key generation. [0075] Although a fixed value may be used as the initial value for random number generation, using the same initial value leads to the generation of a fixed random number, meaning that the initial value should be varied for stronger security. To vary the initial value, a specific rule may be used or the initial value may be generated based on the movement date. [0076] Next, the take-out information creation unit 105 generates an encryption key using the planned route, which is acquired in step 803 in FIG. 8 and from which a loop portion is deleted, and the random number generated in step 901 (step 902 ). A known generation algorithm is used for generating the encryption key. [0077] As an example of encryption key generation, the following describes a simple example in which bit shifting is used. The character string “M 1 M 2 M 3 M 4 ”, which is the concatenation of the character strings of partial area IDs, is generated from the partial-area-based planned route (M 1 →M 2 →M 3 →M 4 ). The character string “M 1 M 2 M 3 M 4 ” is converted to a binary number and the bits are shifted to the left by the number of the random number generated in step 901 . If the value of the binary number generated by converting the character string “M 1 M 2 M 3 M 4 ” is “11001010” and the random number is 2, the value is shifted to the left by two bits and the encryption key “00101011” is generated as the encryption key. A method other than the bit-shift method may also be used for encryption key generation. [0078] Next, the take-out information creation unit 105 encrypts the customer information, which will be browsed at the destination M 4 , using the encryption key generated in step 902 , (step 903 ). A known encryption method, such as the XOR encryption, may be used for the encryption. As an example, the following shows a specific example in which the XOR encryption is used. When the value generated by converting the customer information to a binary number is “1010111001010001” and the encryption key generated in step 902 is “00101011”, the two values are XORed. The result of the XOR operation between the high-order 8 bits of the customer information and the encryption key is “10000101”, and the result of the XOR operation between the low-order 8 bits of the customer information and the encryption key is “01111010”. As a result, the encrypted customer information is “1000010101111010”. [0079] FIG. 10 is a flowchart showing the information display processing performed by the information display device 110 . First, the information access control unit 115 acquires the history of the position information from the position information history management unit 111 via the position information management unit 113 (step 1001 ). Step 1001 is triggered when the user presses the button, when the pre-set time is reached, or when the information display device 110 is powered on. [0080] Next, the information access control unit 115 initializes the actual route based on the position information history acquired in step 1001 (step 1002 ). First, the information access control unit 115 calculates the road link sequences on a time-series basis from the position information history acquired in step 1001 . Next, the information access control unit 115 acquires the partial area information from the partial area information management unit 119 via the movement monitoring unit 118 . After that, the information access control unit 115 calculates the partial-area-based actual route from the calculated road link sequence and the partial area information and initializes the calculated actual route. When the road-link-based actual route is used, the information access control unit 115 uses the road link sequence, acquired from the position information history, for the initialization. When the destination-based actual route is used, the information access control unit 115 acquires the data, whose destination arrival flag 504 is “1”, from the position information history management unit 111 as the position information history. Next, from the acquired position information history and the partial area information, the information access control unit 115 calculates the partial area array, corresponding to the destination, as the actual route. [0081] The information access control unit 115 regularly executes steps 1003 to 1010 at intervals of a predetermined time. First, the information access control unit 115 transmits a current position acquisition request to the position information management unit 113 . The position information management unit 113 acquires the sensor information from the position sensor 125 , acceleration sensor 126 , and gyro sensor 127 periodically (for example, every second) via the sensor information acquisition unit 114 . The information access control unit 115 identifies the current position on the map based on the acquired sensor information and the map information managed by the map information management unit 112 . [0082] A known method may be used to identify the current position on the map (called mapping). The position information management unit 113 saves the identified position information and the road links in the position information history management unit 111 . The position information management unit 113 returns the identified current position and the road links in response to the request from the information access control unit 115 . [0083] In step 1004 , the information access control unit 115 transmits an inquiry to the movement monitoring unit 118 to identify the partial area corresponding to the current position of the information display device 110 . When road links are used as the actual route, no processing is performed in step 1004 because the road link is already identified in step 1003 . [0084] In step 1005 , the information access control unit 115 determines if the identified partial area/road link is changed. The movement monitoring unit 118 , which memorizes the previous partial area/road link, compares the previous partial area/road link with the partial area/road link identified from the current position to determine if the partial area/road link is changed. If the partial area/road link is changed (Yes in step 1005 ), control is passed to step 1006 . If the partial area/road link is not changed (No in step 1005 ), control is passed to step 1010 . [0085] If the movement monitoring unit 118 determines that the information display device 110 has moved and the partial area, to which the information display device 110 belongs, is changed, the information access control unit 115 updates the actual route (step 1006 ). For example, if the actual route is “M 1 →M 2 →M 3 ” and the partial area is changed from M 3 to M 4 , the information access control unit 115 updates the actual route to “M 1 →M 2 →M 3 →M 4 ”. Next, the information access control unit 115 updates the customer information display permission (step 1007 ), makes the browsable customer information non-browsable, or makes non-browsable customer information browsable. The update processing of customer information display permission will be described later in detail with reference to FIG. 11 . [0086] Next, if it is determined in step 1005 that the partial area is changed, the information access control unit 115 checks if a warning to the user is necessary (step 1008 ). The movement monitoring unit 118 searches the warning information management unit 120 using the IDs, associated with the partial area change (before-movement partial area ID and the after-movement partial area ID) as the key. If the corresponding record is searched for, the warning is necessary; conversely, if the corresponding record is not searched for, the warning is not necessary. For example, if the partial area is changed from M 1 to M 2 in step 1005 , the movement monitoring unit 118 searches for a record whose before-movement partial area ID 701 is M 1 and the after-movement partial area ID 702 is M 2 . If the warning is necessary, the movement monitoring unit 118 transmits a warning notification request to the information access control unit 115 . [0087] In step 1009 , a route departure warning is notified to the user. If it is determined in step 1008 that the warning is necessary, the information access control unit 115 displays the warning screen on the display 128 and outputs the warning sound or warning voice message from the speaker 129 . The warning may be issued only once, may be continued for a predetermined time, or may be continuously issued until the user returns to the original route. [0088] The warning screen and the warning sound/warning voice message may be notified synchronously, the screen and the sound may be notified for different lengths of time, the screen and the sound may be notified at different times, or one of them may be notified. When the user has mistakenly departed from the route, the warning notifies the user that the user has departed from the route to allow him or her to return to the original route. [0089] The number of warning notifications is stored and, if the number of warning notifications exceeds the predetermined upper limit, all the encrypted customer information is deleted. Doing so protects the customer information even if a third party acquires the information display device 110 fraudulently and moves along the routes on a trial and error basis. [0090] In step 1010 , the information access control unit 115 determines if the processing is to be terminated. If the processing is not yet terminated (No in step 1010 ), control is passed back to step 1003 . The determination to terminate the processing may be triggered when the user presses the button or when the information display device 110 is powered off. [0091] FIG. 11 is a detailed flowchart showing the update processing for customer information display permission (step 1007 in FIG. 10 ) performed by the information access control unit 115 . First, the decryption unit 116 generates a random number, which is used for generating the decryption key, in response to a request from the information access control unit 115 (step 1101 ). The initial value of the random number is the same as the initial value used in step 901 in FIG. 9 . [0092] Next, the decryption unit 116 acquires the actual route, which is used as the input information for decryption key generation, from the information access control unit 115 and deletes a loop portion from the actual route (step 1102 ). Assume that the originally-scheduled planned route is “M 1 →M 2 →M 3 ” but that the user mistakenly departed from the route and the actual route becomes “M 1 →M 2 →M 4 →M 2 →M 3 ”. When the user mistakenly takes a wrong route and then returns to the original route, a part of the actual route becomes a loop. In the example given above, the part “M 2 →M 4 →M 2 ” is a loop. This loop portion, which is not an originally-scheduled planned route, is deleted, and the “M 1 →M 2 →M 4 →M 2 →M 3 ” is corrected to “M 1 →M 2 →M 3 ”. [0093] Because all the actual routes, including those of yesterday and days before, can be acquired in step 1102 , the actual route long enough for decryption key generation is selected from the acquired actual route. For example, when the actual route acquired in step 1102 is “M 1 →M 2 →M 3 →M 4 →M 5 →M 6 →M 7 ” and the length of the actual route required for decryption key generation is 3, the three “M 5 →M 6 →M 7 ” closest to the current position are selected for decryption key generation. [0094] The decryption key is generated using the actual route selected as described above and the random number generated in step 1101 (step 1103 ). The initial value, the random number generation method, and the decryption key generation algorithm, which are used for generating the decryption key, are the same as the initial value (or the generation method), the random number generation method, and the key generation algorithm used for encryption key generation in step 902 in FIG. 9 . [0095] In step 1104 , the customer information is decrypted using the decryption key generated in step 1103 . Because it is not determined to which destination the user is traveling, the decryption processing is performed for all the encrypted customer information managed by the encrypted information management unit 117 . In decrypting the customer information, the algorithm corresponding to the encryption algorithm is used. [0096] In step 1105 , the customer information access permission (display permission in this case) is updated based on whether or not the customer information is decrypted successfully, and the result is notified to the user. The method for notifying the result to the user will be described in detail later with reference to FIG. 13 . [0097] One method for determining if the decryption was successfully done is that the character string, such as “OK”, is written in a predetermined position of the customer information and, after the decryption, a check is made if the character string “OK” can be read from the decrypted information to see if the decryption was successful. Another method is that, instead of directly writing the character string in the customer information, a confirmation file in which only “OK” is written is prepared and the confirmation file is decrypted in the same way as the customer information. The confirmation file is decrypted, and a check is made if the character string “OK” is can be read to see if the decryption was successful. [0098] In this case, a confirmation file is required for each piece of customer information. For example, if there are two pieces of customer information named “info1.data” and “info2.data”, the confirmation files “info1.ok” and “info2.ok” corresponding to the customer information are created. “info1.data” and “info1.ok” are encrypted using encryption key 1 , and “info2.data” and “info2.ok” are encrypted using encryption key 2 . [0099] In step 1106 , the information access control unit 115 determines if decryption is performed for all customer information managed by the encrypted information management unit 117 . If decryption is performed for all customer information (Yes in step 1106 ), the processing is terminated. If there is customer information for which decryption is not yet performed (No in step 1106 ), control is passed back to step 1104 . [0100] FIG. 12 is a diagram showing the image of a planned route. The route from the origin to the destination, written in bold, indicates the route along which the user will travel. The solid line indicates a road, and the dotted line indicates the boundary of a partial area in the grid-like area. In the example in the figure, the area is divided into 36 partial areas arranged vertically and horizontally. The top-left partial area is called “A 1 ”, while the bottom-right partial area is called “F 6 ”. L 1 to L 6 indicate the road link IDs each corresponding to a road link from one intersection to the next. [0101] The route, along which the user will travel, is represented by the partial-area-based planned route as “C 5 →C 4 →D 4 →D 3 →D 2 →E 2 ”. The route is represented by the road-link-based planned route as “L 9 →L 8 →L 6 ”. The route is represented by the destination-based planned route as “C 5 →E 2 ”. [0102] FIG. 13 is a diagram showing the image of the notification screen that notifies the customer information display permission. The route, along which the user will travel, is the route from the origin P 3 to the destination P 4 as in FIG. 12 . The figure shows an example in which a partial-area-based planned route is used for determination. [0103] A screen 1301 shows the screen when the user enters the partial area “E 2 ” corresponding to the destination P 4 . The screen displays the destination as well as the customer information file icons corresponding to the destination. The user can press a customer information file icon to browse the content of the customer information. This example shows that the user can browse the content by pressing a solid-line customer information file icon (active state) but cannot browse the content even if the user presses a dotted-line file icon (inactive state). [0104] Whether or not the user can browse the content may be indicated not only by using the solid line (active) and dotted line (inactive) but also by changing the colors of icons or the sizes of icons. When the partial area of the current position changes from D 2 to E 2 , the customer information files corresponding to P 4 , which have been non-browsable, become browsable. The customer information files corresponding to the destinations other than P 4 become non-browsable. [0105] A screen 1302 shows the screen when the user leaves the origin P 3 and the partial area of the current position changes from C 5 to C 4 . The screen shows that the customer information, which has been browsable at P 3 , becomes non-browsable. There are several methods for notifying the user that the customer information becomes non-browsable: the x symbol is displayed on the customer information file to explicitly notify the user about the state, the customer information file is put in the inactive state (state in which the customer information file cannot be browsed even when the icon is pressed) so that the user cannot browse the customer information, the warning sound is output, the screen is erased, or the screen is flashed. [0106] FIG. 14 is a diagram showing the image of a warning notification that is issued when the user departs from the route. The figure shows an example in which the route, along which the user will travel, is the route from the origin P 3 to the destination P 4 as in FIG. 12 and a partial-area-based planned route is used for determination. This example describes a case in which the user mistakenly turned right at the intersection in the partial area D 4 . Because the user originally intended to travel along the planned route “C 5 →C 4 →D 4 →D 3 →D 2 →E 2 ”, the warning screen or the warning sound/warning voice message is used to notify the user that the user took a wrong route and mistakenly turned right when the partial area changed from D 4 to E 4 . [0107] The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereto without departing from the spirit and scope of the invention(s) as set forth in the claims.

When a user carries a mobile terminal with confidential information, such as customer information, stored therein, it is required to maintain information confidentiality and to prevent an unauthorized third party from accessing the confidential information even if the mobile terminal is stolen. According to the disclosed access control method, an encryption key is generated based on a planned route and the information is encrypted. When the user accesses the information, a decryption key is generated based on the actual movement route that is regularly acquired. The encrypted information can be decrypted if the planned route and the movement route match.

CROSS-REFERENCE TO RELATED APPLICATION [0001] Priority is claimed from U.S. provisional application No. 60/198,177, filed Apr. 19, 2000. BACKGROUND OF THE INVENTION [0002] The invention generally relates to a mobile wireless communication system. In particular the invention relates to a satellite-based mobile wireless communication system having a relational database and to a method and apparatus for maintaining the database current in the face of interruptions in communication. [0003] Freight carrying operations, and in particular, trucking operations in today's environment are growing increasingly expensive to use and thus are forcing on the trucking companies increasingly efficient methods of operation. Some trucking companies are now using global positioning systems attached to their trucks including transponders or antennas, which will enable the trucking companyies to determine the location of the trucks. [0004] Other companies have attempted to automate at least part of the paper handling associated with the trucking company, for instance. It is known that company's such as United Parcel Service have large easel-type computer systems for entry of signatures thereon and verification that products have been received. In addition, trucking and freight forwarding companies often rely on the use of bar codes to track shipments through client server networks in order to determine the location of goods and services. [0005] Oftentimes, however, even with these added features, it is difficult to handle the flow of information efficiently for shipping operations. For instance, it may turn out that a truck driver is to pick up twelve pallets of a particular freight shipment from a company. A driver arrives at the company and is told that he is only to pick up ten pallets. He makes a separate notation because the freight bill should not be changed indicating that he has received less than the full load, and that hand written notation must later be reconciled through a number of steps between the trucking company, or shipper and the company whose product is being shipped. This is time consuming and wasteful. [0006] Another problem that trucking companies are currently faced with is the recruiting of drivers when there is a high competition for drivers. It is often almost impossible to recruit drivers reliably as by the time employment application form is filled out, and transmitted through the trucking company's internal business systems, the driver may have been hired by a competing company. [0007] In addition, while some wireless communication systems have been provided to trucks, the communications are geographically spotty and in some cases also run at relatively low data rates limiting the amount of data that can be sent to the truck or received from the truck and the flexibility of the system. In addition, the system often requires that a driver may have to physically plug a link into a wall socket or the like to obtain access to a telephone system or network which would necessitate stopping the truck, parking the truck for a certain limited period of time in order to transfer the data. [0008] Thus, what is needed is a wide area coverage system with rapid information updating and convenient linking to a truck driver so that the information may be transmitted as near as possible as real time fashion from the driver to the trucking company and from the trucking company back to the driver. SUMMARY OF THE INVENTION [0009] A method and apparatus embodying the present invention comprised of a hub server for storing trucking and shipping information such as electronic freight bills, driver employment forms, and the like in electronic format. The hub server stores the information in relational database that is updated periodically via communications through a satellite ground station. The satellite ground station communicates with an earth satellite which communicates with multiple ground stations at various locations connected to truck stop servers which function as proxy servers. Each of the truck stop servers has associated with it a spread spectrum communication system which can communicate via spread spectrum through wireless modems connected to personal digital assistance or laptop computers being used by truck drivers. In addition, the hub server may be connected to customer servers and to third party servers to exchange information regarding shipments with them. [0010] The system embodying the present invention includes system level applications including the ability to detect network access, a PDA-based web browser and an e-mail client which may communicate over the system assets. Routines also execute processes,. for instance, sending and receiving e-mail, executing database modifications and queries, executing queued applications and the like. This provides a drive-by feature which will enable truck drivers and others to communicate with the network without the necessity of stopping at a wireless local area network location. In addition, the system includes a web browser which is compatible with standard personal digital assistants and standard TCP/IP HTTP/HTML browsers. The browser is capable of caching web pages for offline viewing and allows real-time access to online forms. The browser supports cookies and and SSL technologies by using a proxy server that resides on a node server. [0011] A PDA-compatible e-mail client also functions on the network. Specific features of the client will include the ability to download email from truck stop server mail servers allowing POP/SMTP access. The ability to link to address books and an option to download email headers only for compact display. In addition, leave message-on-server activities are supported. [0012] More specifically, trucking companies can send pay settlements and pay stubs to drivers over the network in order to provide timely detailed descriptions of the drivers pay. This will reduce operating costs through the elimination of long distance calls to trucking company payroll departments. The system may be integrated with trucking company application servers, typically IBM AS-400 computers in order to automatically generate formatted email pay settlements. [0013] An authorized fuel network application enables trucking companies to inform drivers in real time over the network of fuel network changes including changes in fuel pricing. Drivers are able to receive directions over the network to fuel stops as well as listing of amenities thereat. This enables trucking companies to save significant amounts of money by utilizing appropriate fuel stops with low prices and receiving the most current and lowest pricing available. The fuel network application is managed and updated through-a web browser interface as necessary by trucking company fuel managers. [0014] Truck maintenance tracking is also available. Maintenance information is entered and transmitted wirelessly to a fleet maintenance department of the trucking company over the network for recording. The driver or company receives notification through a PDA or through a hub server of upcoming scheduled maintenance. The database has regularly performed maintenance and time or mileage intervals available. The database may be customized by individual trucking companies to enter their own maintenance schedules. [0015] Local condition reporting may be performed over email. A driver uses his PDA to send email to a maintenance facility warning that there is a problem that needs attention. This enables a maintenance bay to be reserved before the driver arrives at the facility, thereby saving time. [0016] Part of the database information to be made available from the hub server will be indications of freight which is to be hauled. The users have the ability to enter specific search criteria including starting location, destination, trailer type, availability, time and date. Once entered, the search criteria are compared to third party load databases through the hub returning matching loads, as indicated through the PDA. The driver may then have discretion selecting a load. [0017] Electronic freight bills will be prepared by the system and will enable drivers to electronically exchange freight bills with the trucking company, shippers and consignees. Electronic freight bills complete a logistic chain by providing both in-transent visibility and data integrity throughout a shipping cycle.. [0018] Electronic employment applications are also handled by the network and may be completed by driver applicants on hand-held computers such as PDA's or laptops. The application is in a wizard format and captures the applicant's signature. Once complete, the recruit's application and signature are sent electronically over the network to the trucking company's recruiting office for rapid processing. Individual trucking companies may customize at least a portion of the employment application and input the recipient's email address, track sender information, and integrate it into existing services. [0019] Electronic driver logs are handled by the system, wherein drivers through their PDA's will enter time and activity, including driving, sleeper berth, off duty or on duty, not driving. The software will verify that all hours are legal. After entry of the information in the PDA or laptop, a graphic similar to paper logs will be displayed on the PDA or laptop computer. The log book entry will then be delivered electronically to the trucking company over the network for recording in the trucking company databases. The log entries will include the date, including month, day and year, the vehicle number, driver I.D., the miles driven that day, the name of the carrier or carriers, the main office address, the home terminal address, name of co-driver, if any. Including, in addition, the hourly entries will have descriptions associated with them including city, state, shipping yard activity, loading, unloading, fueling and the like. [0020] In order to carry out all of the above tasks, a database replication system is provided by the apparatus and method embodying the instant invention. For scheduling large bursts of data so that when satellite connections are created an efficient use of network resources can be obtained. Between the bursts of data, all data remains available at all access points on the network. Race conditions are eliminated by conflict resolution logic built into the server and client side applications. [0021] A central controlling server or hub functions as a master synchronizing system for all external access points or truck stop stations (TSS). If a change occurs in the database located in the hub, the change is broadcast to all the TSS. If a change occurs in the database located on one of the truck stop servers, then that change is sent back to the hub and then broadcast to all of the stations. All broadcasts are sequenced in a manner similar to that done for transmission control protocol packets for error correction so that the broadcast provides a reliable transport method for all systems. A satellite network compatible with television signals allows six megabit per second bursts to all stations on the hub. TSS stations communicate back to the hub using a 6K per second data rate. The data moving from a TSS back to the hub is relatively small compared to the outbound data from the hub. By design the network only allows forty connections to be created from TSS stations to the hub. This has the benefit that it will guarantee that the hub will not be overrun by communication requests from the TSS station. [0022] The satellite communication is run over a Cislunar Networks system using compression technology that allows data to be efficiently transmitted at low cost. Each of the wireless local area network (WLAN) sites is comprised of a proxy server or TSS and wireless access points. The server enables local storage and rapid access to very large amounts of data. This combination of truck stop server and wireless access points enables information to be accessible by network subscribers from within their vehicles, local restaurants, and the like without being required to send and receive information over land lying communications. The wireless LAN network implements IEEE 802.11 b wireless technology using spread spectrum technology. [0023] This communicates wirelessly to PDAs which, in the present embodiment, are Palm-OS units or devices which are compatible therewith. In the alternative, a Symbol 1740 wireless Palm OS computer may be used. In order to provide security the software performs 128 bit encryption on data being transferred between servers. Encryption is based on 64 wired equivalence privacy standards and uses a 40 bit secret key plus 24 bit initialization vectors. [0024] It is an aspect of the present invention to provide a complete end-to-end wireless communication system for use in the trucking industry to allow truck drivers to quickly and effortlessly communicate trucking related information as well as personal information via email and web browser with a hub server which may be connected to a variety of trucking company servers and third party servers. [0025] It is another aspect of the present invention to provide communication which is wireless and need not be linked to ground-based systems. [0026] It is a still further aspect of the present invention to provide a wireless trucking information communication system which provides rapid and accurately real-time data updating over satellite communications. [0027] Other aspects of the invention will become obvious to one of ordinary skill in the art upon a perusal of the following specification and claims in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0028] [0028]FIG. 1 is a block of an apparatus embodying the present invention; [0029] [0029]FIG. 2 is a block diagram showing the relationship between the hub server and a customer network and the internet; [0030] [0030]FIG. 3 is a block diagram of a link between a hub server and a satellite system to a truck stop server and network connections to wireless access points; [0031] [0031]FIG. 4 is a block diagram of the connection from a satellite receiver to truck stop servers and personal digital assistants and laptops; [0032] [0032]FIG. 5 is a block diagram of the contents of a synchronization packet; [0033] [0033]FIG. 6 is a flow chart showing details of information provided for electronic driver load indications; [0034] [0034]FIGS. 7A and 7B are a table of the types of descriptions of equipment which is stored in the database and handled by the PDAs; [0035] [0035]FIG. 8 is a flow chart of the manner in which an electronic log is kept; [0036] [0036]FIG. 9 is a flow chart of the handling of an electronic flat belt; [0037] [0037]FIG. 10 is a flow chart showing steps of incoming data management for a hub; [0038] [0038]FIG. 11 is a flow chart showing steps of outgoing data management for a hub; [0039] [0039]FIG. 12 is a flow chart showing steps of incoming data management for a truck stop server; [0040] [0040]FIG. 13 is a flow chart showing steps of outgoing data management for a truck stop server; [0041] [0041]FIG. 14 A and 14 B are renderings of screens for the preparation of electronic freight bills; and [0042] [0042]FIG. 15 is a rendering of the driver application screens presented on a personal digital assistant or laptop computer for transfer of data via truck stop server to a hub. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0043] Referring now to the drawings, and especially to FIG. 1, an apparatus that is generally referred to by reference numeral 10 and embodying the present invention is shown therein. The central hub server 12 which includes a web server having a data synchronization system, a database and an interface 13 is connected to a satellite teleport 14 which is able to communicate with an earth satellite 16 with a type which carries television transmissions. In this case it is a GE 4 satellite. The satellite also sends signals to a satellite teleport 18 which is a ground-based station connected over a link to a local node server or proxy server or truck stop server (TSS) 20 which also includes system synchronization process software as well as a TSS database. Multiple TSSs are connected to the system at various truck stops. The proxy server can communicate a portion of its database information to a wireless access point which is a spread spectrum transceiver system communicating using IEEE802.11 b protocols with a hand held computer 24 which may comprise a palmal S device, a Windows CE device, etc. including a wireless modem therein which is compatible with 802.11. In addition, information from the hub server may be shared with a company network 26 which may communicate via the Internet 28 to company customers through an Internet service provider 30 which is coupled to a customer network 32 . The customer network 32 includes customer data 34 which may be related to trucking company data, advertising data, etc. The customer network has connected to it a customer gateway server and storage for intermediate data for manipulation in other instances. [0044] Referring now to FIG. 9 an incoming data management flow for the hub is shown therein, including a step 100 , which the hub incoming data manager receives updates over the satellite network from a truck stop server. In a step 102 the data is placed in an incoming cubed table. In a step 104 the hub cube manager monitors the queue for arriving updates and checks for sequential updates in a step 106 . In a step 108 the system checks for sequenced group updates in order to ensure the groups contain the correct number of entries which are expected. In a step 110 , the updates are applied to the database assuming that the sequence group updates and the sequential updates were in order. In a step 112 , the update entries are placed in a hub outgoing queue. In the event that the sequential update check is not passed in step 106 , a request is made in a step 114 directly to the TSS for missing data. The hub is-then contacted but responds with no data in a step 116 and generates an administrative message in a step 118 . In a step 120 the missing record or group is ignored and the process continues. In the event that the sequence group update check of step 108 fails, the request is made to the TSS for the missing data, which is similar to the step 114 in a step 122 . The TSS responds with the missing records in a step 124 , and transfers control back to the step 110 . [0045] For outgoing data management, as may best be seen in FIG. 11, in a step 130 , the hub outgoing data manager monitors an outgoing queue. In the step 132 , a log is checked for the last broadcast sequence number. In step 134 , a broadcast sequential update and group entries to all TSS systems via packet broadcast across the satellite network takes place and then in a step 136 , the update entry is moved to a revolving history table. In addition, in the step 138 , the hub listens for direct incoming requests for missing update entries and receives requests from the TSS from the missing entries in a step 140 . A lookup update occurs in a step 142 history table if the entry is not found and no response is sent to the TSS in the step 144 , if the entry is found, a request is sent back to the TSS in a step 146 . [0046] The truck stop server incoming data management is handled, as may best be seen in FIG. 12, in a step 150 , an incoming data manager receives updates from the hub server in a step 152 , the data is placed in an incoming queue table. In a step 154 , the TSS queue manager monitors the queue for arriving updates in a step 156 , sequential updates are checked. If the sequential updates check fails, control is transferred to a step 158 causing a request to be made directly to the hub for the missing data. In a step 160 , the hub is successfully contacted but responds with no data and generates an administrative message in step 162 , causing the missing record or group to be ignored in a step 164 , and control to be transferred back to step 154 . In a step 166 , a check is made for sequence group updates in order to ensure that the groups are complete and contain the correct number of entries. In the event that the check fails, control is transferred to a step 168 which requests data from the hub, and the hub responds in a step 170 , with the missing records transferring control to a step 172 , wherein entry is checked to see if the origin TSS I.D. is the current TSS. The updates are applied to the database in a step 174 , and entries are removed from queue and store in a revolving history table which is not allowed to be older than thirty days in a step 176 . [0047] The TSS outgoing data management is handled as may best be seen in FIG. 13, wherein a step 180 the TSS outgoing data manager monitors an outgoing queue. In a step 182 , the log is checked for the last update entry sequence number. In a step 184 , the outgoing queue is checked for grouped entries. In a step 186 , a sequential update and grouped entries are sent to the hub system by a transmission control protocol across the satellite portion of the apparatus 10 . In a step 188 , the update entry is moved to revolving history table. In addition, the TSS listens for direct incoming requests for hub, for missing update entries in a step 190 . If a request is received in a step 192 , a step 194 is executed causing a lookup update entry in the history table. If the entry is found in a step 196 , the information is sent back to the hub, if the entry is not found, a no response is sent to the hub in a step 198 . [0048] Of the types of information which are sent, the information is packaged as may best be seen in FIG. 6, where the synchronization packet detail is shown with the synchronization packet 200 comprising an SQL payload size field 202 , a packet type field 204 , a sequence number 206 , a group sequence number 208 , an origin TSS identifier 210 , a time stamp 212 , a database name 214 , a database user identification 216 , a database password 218 , and finally the SQL statement itself 220 . Thus, it may be appreciated that both group and sequence information as well as time stamping, database naming and database user information and password is transmitted in the synchronization packets. The synchronization packets may be used to send electronic load information as shown in FIG. 6, wherein a step 250 , an authentication is done, a match is checked for in a step 252 , and a load type is selected in a step 254 . Connection may be made to the driver in a step 256 allowing equipment to be selected from a listing in a step 258 , the origin city is inserted in step 160 , the origin state in a step 262 , the distance radius in a step 264 , the destination city in a step 266 . In addition, the destination state is inserted in a step 268 as well as the radius in a step 270 , and the results are compiled in a step 272 . In addition, links can be made to a fleet in a step 280 , or to a fleet intranet in a step 282 to forward the information, as well as the information being sent over the internet in a step 286 to available websites in a step 288 . Equipment type may also be identified as set forth in the tables in FIGS. 7 A and FIG. 7B identifying containers, types of decks, bulk shipping, types of flatbeds, whether hazardous material handling equipment is needed, refrigerated equipment, tankers, vans, or specialized vans. [0049] Furthermore, an electronic log book function is provided as set forth in FIG. 8, at a log start time at a step 300 , the status, city, states, and notes may be entered in a step 302 for transmission. A test is made for a status change in a step 304 , a test is also made for last status off in a step 306 and whether last status is sleeper berth in a step 308 . In addition, a test is made to determine whether the last status indicates driving in a step 310 , if it is then a step 312 a test is made to determine whether the number of driving hours since 8 hours rest exceeds ten hours. If it is, a warning is issued in a step 314 . If it is not, is the driving hours plus the on hours, since eight hours rest greater than sixteen as tested for in a step 316 , if it is a greater-than fifteen hour warning is issued in a step 318 . Control is then transferred to a step 320 , where a determination is made as to whether a seventy hour warning needs to be issued, and if so a seventy hour warning is issued in a step 322 . Control is then transferred back to a test step 324 to test for sleeper berth and to an end of the day log in a step 326 which may loop back to log start times, back in 300 . [0050] As may best be seen in FIG. 9, the carrier database 400 allows data to be automatically extracted and entered by a gateway end server 402 or allows a fleet manager to enter data via website 404 . In step 406 , data populates the hub database and is then replicated to all of the truck stop stations via the network. In a step 408 , the driver information is synchronized over the wireless local area networks and data is downloaded to the end devices such as the PDAs or the laptop computers. A test is made in the step 410 to determine if the shipper information is complete, if not, control is transferred to a step 412 prompting completion of the driver shipper information. A test is made in a step 414 to determine if the consignee information is complete, if it is not, the driver or shipper completes the information in a step 416 . If it is, control is transferred to a stop offs check 418 to determine whether that information has been entered, if it has, the driver and shipper is prompted to complete it in a step 420 and a ship operation signal is given in a step 422 . [0051] A driver consignee review may be made in a step 424 . OSD information is checked for in a step 426 and if it is not present, the information is entered in a step 428 . The consignee can sign off in a step 430 after which the stop officer identified in a step 432 , and the data is stored until the driver enters the wireless local area network in a step 434 where it can be downloaded. [0052] Among the data which can be sent, it may best be seen in FIG. 14A are electronic freight bills which include the originators name, address, city, phone number and directions, as well as consignee information including the destination name, address, city, telephone number, zip code and directions to the consignee. Carrier information may be provided, such as the trucking company, the tractor number, the trailer number, as well as a bill of lading menu to indicate whether signatures are required, identify the load number. The bill of lading will also identify the quantity, the description of the material and the weight. [0053] In addition, information can be sent over the network related to a driver application, employment application form is shown in FIG. 15, which may be completed over a PDA. As shown, the PDA includes personal information, safety record, current employer, screens drivers license information prompts, types of training prompts and employment detail, even asking for specific information such as histories of accidents, citations received, driving under the influence offenses and license suspensions and revocations. Finally, the PDA provides a place for the applicant signature to be inserted and digitized and forwarded to the hub. [0054] While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

An apparatus and method have a hub server for storing a relational database of information relating to trucking operations. The hub server is connected via a satellite link to an earth satellite which is connected through downlinks and uplinks to localize truck stop servers (TSS). The TSS in turn communicate via spread spectrum radio frequency signals with hand-held computers, such as personal digital assistants. The PDAs are used by truck drivers to send and receive e-mails and other information such as electronic freight bills, fuel information, route information and the like from the trucking company and to transmit information to the trucking company. In addition, a trucking company server may be accessed through the Internet by customer servers or third party servers to identify aspects of the trucking shipment.

FIELD OF THE INVENTION The present invention relates to a computer-implemented method and apparatus for automatically labeling maps or graph layouts in accordance with predefined label criteria. BACKGROUND OF THE INVENTION Maps include geographic drawings showing countries, cities, rivers, bodies of water, mountains, and other features of interest. Labeling cartographic features is a fundamental part of map-making. Placing each label optimally with respect to its corresponding feature invariably produces labels overlapping each other or too close to each other. As this results in confusion and unacceptable maps, methods to reposition labels or not draw them at all must be used to create a map that conveys as much information as possible. Tagging graphical objects with text labels is a fundamental task in the design of many types of informational graphics. This problem is seen in its most essential form in cartography, but it also arises frequently in the production of other informational graphics such as scatter plots. The quality of a labeling is determined essentially by the degree to which labels obscure other labels or features of the underlying graphic. The goal is to choose positions for the labels that do not give rise to label overlaps and that minimize obscuration of features. Construction of a good labeling is thus a combinatorial optimization problem, which has been shown to be NP-hard (Marks and Shieber, 1991). As a hypothetical baseline algorithm, randomly choosing positions for each label generates a poor labeling, both aesthetically, and as quantified using a metric that counts the number of conflicted labels, i.e., those that obscure point features or other labels. In addition to geographical and technical maps, there are many labeling applications relating to graph layouts and drawings. These applications include, but are not limited to, areas such as database design (e.g. entity relationship diagrams), software engineering including CASE, software debugging, complex web pages, CAD drafting, complex electrical diagrams, and telecommunications and communications networking. In fact, the labeling of the graphical features of any drawing is generally necessary because it conveys information essential to understanding the drawing. For complex and information rich drawings, computer aided labeling is increasingly employed. As used in the present specification, the term “map” is used to include both geographical and technical maps as well as graph layouts and drawings. The term “label” is used to refer to text or other indicia to be placed on a map. A system and method for labeling objects on maps while avoiding collisions with other labels has been sought after. Some apparently powerful algorithms for automatic label placement on maps use heuristics that capture considerable cartographic expertise but are hampered by provably inefficient methods of search and optimization. This patent discloses a system and method for label placement that achieves the twin goals of practical efficiency and high labeling quality by employing cartographic heuristics. SUMMARY OF THE INVENTION The present invention provides a computer-implemented system and method of automatically labeling a map in accordance with predefined label location, placement, and priority criteria. Here, each label is represented as a convex polygon with any orientation on the map. Labels have various parameters associated with them such as location, size, shape, number and location of vertices, target feature, priority, movement constraints, and clearance. After finding the best position of a label for every feature without regard to other labels or features, higher priority label positions are compared to lower priority label positions two at a time. If the labels interfere, the lower priority label is moved within its movement constraint. Several candidate locations for the lower priority label position are found by moving it the shortest distance to avoid the higher priority label position. A new location is acceptable if the location does not collide with a label of higher priority. It can collide with a label of lower priority. If no candidate positions are acceptable, the label is not moved. This process continues until all labels are inspected, after which a deviation from the desired result function is calculated. This function is zero if the label interference for all labels is zero and greater than zero otherwise. The whole process is repeated until the evaluation function equals zero or the change in the evaluation function is less than a given percent (e.g., two percent) for a small number (e.g., four) of iterations or if it oscillates for a number (e.g., six) of iterations or if the number of iterations is greater than a set number (e.g., twenty). If any interference remains, then interfering labels with lower priorities are not drawn. The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a computer hardware architecture compatible with the present system and method. FIG. 2 is a schematic diagram showing an exemplary computer program product. FIG. 3 is a flow chart showing the overall logic of the present system and method. FIGS. 4 a , 4 b , and 4 c is a flow chart showing the initialization of the anti-collision system and method. FIG. 5 is a flow chart of the sorting labels by priority. FIG. 6 is a flow chart showing the initialization of halting criteria variables. FIGS. 7 a and 7 b is a flow chart showing the test of whether each label has been tested. FIG. 8 is a flow chart showing the overlap test FIGS. 9 a , 9 b , and 9 c is a flow chart showing the movement procedure. FIG. 10 is a flow chart showing the initiation of collision scores and priority ranges. FIG. 11 is a flow chart showing the calculation of the evaluation function. FIG. 12 is a flow chart showing the halt routine. FIG. 13 is a flow chart showing the routine to adjust label properties. FIG. 14 is a flow chart showing the return to caller. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring initially to FIG. 1 , a system is shown which includes a digital processing apparatus. This system is a general-purpose computer 1000 . The computer may include a graphics display, print hardware, and print software, or may be as simple as a generic personal computer. The example computer in FIG. 1 includes central processor 1010 , system memory 1015 , disk storage 1020 (e.g., hard drive, floppy drive, CD-ROM drive, or DVD drive), controller 1005 , network adapter 1050 , video adapter 1030 , and monitor 1055 . Data input may be through one or more of the following agencies: keyboard 1035 , pointing device 1040 , disk storage 1020 , local area network 1060 , point to point communications 1065 , and wide area network 1070 (e.g., internet). One or more features of the computer as shown may be omitted while still permitting the practice of the invention. For example, printer 1045 is not necessary for maps intended to be displayed only on monitor 1055 . Likewise, network adapter 1050 , local area network 1060 , point to point communications 1065 , and wide area network 1070 are not necessary when the primary method of data input is via removable disk storage. The flow charts herein illustrate the structure of the logic of the present invention as embodied in computer program software. Those skilled in the art will appreciate that the flow charts illustrate the structures of logic elements, such as computer program code elements or electronic logic circuits, that function according to this invention. Manifestly, the invention is practiced in its essential embodiment by a machine component that renders the logic elements in a form that instructs a digital processing apparatus (that is, a computer) to perform a sequence of function steps corresponding to those shown. FIG. 2 shows a computer program product which includes a disk 1080 having a computer usable medium 1085 thereon for storing program modules a, b, c, and d. While 4 modules are shown in FIG. 2 , it is to be understood that the number of modules into which the program is divided is arbitrary and may be in any particular embodiment a different number. Modules a, b, c, d may be a computer program that is executed by processor 1010 within the computer 1000 as a series of computer-executable instructions. In addition to the above-mentioned disk storage 1020 , these instructions may reside, for example in RAM or ROM of the computer 1000 or the instructions may be stored on a DASD array, magnetic tape, electronic read-only memory, or other appropriate data storage device. In an illustrative embodiment of the invention, the computer-executable instructions may be lines of compiled C++ code. FIG. 3 is an overview and summary of the label anti-collision procedure for maps. The caller of the procedure performs the first stage, routine 5 , and the second stage, routine 8 . Routine 5 involves locating each label on a map in the optimal position with respect to its target feature without regard to other labels or features. Routine 8 assigns properties to the map and the labels. To begin, the user must specify how to initially place labels on a map. That is, commencing at routine 5 , it is assumed that the user will assign positions that give the best label location with respect to its associated feature. For this procedure to work, the user places the labels in the best spots according to their criteria regardless of other labels and map features. For example, in the initial positions, labels may overlap each other and/or extend over the map boundary. Labels are assumed to be convex polygons while the map boundary is assumed to be a rectangle. Next, at routine 8 , the user must assign properties to the map and the labels. Map properties include its height and width. A label's properties include the associated map feature(s), initial location, size, shape, angular orientation, priority, movement constraints, and clearance. In addition, each label has an associated property that indicates the fraction of the label area that can extend outside the map boundary before it is not drawn. The procedure takes all of these properties into account to move labels to acceptable positions or to not draw the label. The following discussion concerns only those geometric objects in the plane of the map, of which the labels are a part. All labels are restricted to convex planar polygons in this plane. A planar polygon is convex if it contains all the line segments connecting any pair of its points. If two convex planar polygons overlap, this means that: 1) at least one vertex of one polygon is inside the other polygon, or 2) at least one edge of one polygon crosses or touches (i.e., intersects) an edge of the other polygon. To begin the anti-collision procedure, three initialization steps occur. First, labels lying partially inside the map boundary must either be moved completely inside the portrait or be excluded from being compared to other labels and excluded from being drawn. Each label has movement types and constraints that determine whether or not the label qualifies for movement completely onto the map. These movement types and constraints are explained below. Labels qualifying for movement to the inside of the map are moved regardless of the collision status with any other label. Second, the labels must be ordered in a list with respect to priority from highest priority to lowest priority. In general, many labels will have the same priority. Within any group of labels with the same priority, any particular label is randomly placed within that block. Third and last, variables that monitor the state of the procedure must be initialized. The purpose of routine 10 is to move labels within the map boundary. If too much of a label is outside the boundary, it will not be included in the map. Each label is tested to determine what fraction of its area is within the map boundary. At routine 20 , labels are sorted in order of descending priority. Halting criteria parameters are initialized at routine 30 . Every combination of two labels is tested for overlap in routine 40 . When comparing labels to determine if they overlap, it is important to choose the order of comparison properly to avoid excessive calculation and moving labels more times than necessary. The highest priority labels should be tested for overlap before labels of lower priority. The overlap test at routine 45 has three parts. First, it must be determined if any vertex of a first label is inside the second label. Second, it must be determined if any vertex of a second label is inside the first label. Third, it must determine if any edge of the first label intersects any edge of the second label. If at any point either label is determined to overlap the other label, then any remaining parts are bypassed. Labels are moved about the map at routine 50 to clear existing label collisions. After it is determined that two labels overlap, the routine finds several new locations for the lower priority of the two labels that eradicate the existing overlap. These locations are ranked by how far the label must be moved, shortest to longest. Then if appropriate, the lower priority is moved to a new location, and its location parameters are adjusted. The evaluation function, routine 60 , quantifies the extent of label collisions. Routines 40 , 45 , 50 , and 60 iterate until halt routine criteria 70 are satisfied. Labels may move several times before the iterations stop. After the iterations stop, all labels are examined for any overlap and label properties are adjusted at routine 80 . Finally, control is returned at routine 90 to the user to draw or view the map. FIGS. 4 a , 4 b , and 4 c display the logic of routine 10 in detail. The purpose of routine 10 is to make sure all of a label is within the map boundary. If too much of a label is outside the boundary, it will not be included in the map. Each label is tested to determine what fraction of its area is within the map boundary. A particular label is divided into a grid; 32 by 32 cells is a typical division that works well in practice. If the centroid of a cell is within the map boundary, the entire cell contributes to the fraction of the label within the boundary. The areas of each cell within the map are added to together. If this sum of cell areas, divided by the total label area, is greater than a predetermined value, then the label is moved entirely onto the map according to the movement procedure and the movement constraints described below. The only change to the procedure is that there is no test for overlap with other labels. The qualifying labels are moved onto the map at this time and tested later. Step 100 obtains a list of labels from data storage. Each label is tested for whether the entire label is inside the map boundary. First, step 108 initializes flags that will be used in routine 10 . Step 112 tests whether vertices of each label are outside the map boundary. If the vertices of a label are all inside the map boundary, then the next label is tested. If any vertices of a label are outside the map boundary, then, at step 116 , a circumscribing rectangle is placed around the label. Then the circumscribing rectangle is divided into a plurality of cells at step 120 . For example, the rectangle may be divided into 64 cells by 64 cells forming a total of 4096 cells. Each cell is tested, step 124 . The test includes finding the center point of each cell to find the number of cells inside the label, step 128 . Then, at step 132 , the center point of each cell used to find the number of cells both inside the label and inside the map. The fraction of the label inside the map boundary is determined at step 136 . The high and the low values of the x and y coordinates for the vertices of the label are found in step 140 . Then the label is tested, step 144 , to determine if the fraction of the label inside the map boundary is high enough to qualify for attempted movement inside the map. There is one of two possible ways the label might move depending on its movement constraints, which is determined in step 148 . One movement, in both the x-axis and y-axis direction, is performed in steps 152 , 156 , 160 , 164 , and 168 . The other movement, restricted to a vector, is performed in steps 172 , 176 , 180 , 184 , and 188 . If the label is partially or totally outside the map, and cannot be properly moved within the map, which is checked in step 192 , then a parameter for that label is set in step 196 . Once all labels have been tested, step 104 exits routine 10 and proceeds to routine 20 . Referring to FIG. 5 , labels are sorted by priority at step 200 from the highest priority label to the lowest priority label and placed into a data structure map. Step 210 exits routine 20 and proceeds to routine 30 , an initialization of halting criteria variables. In FIG. 6 , step 300 initializes halting criteria variables. Step 310 exits routine 30 and proceeds to routine 40 , a test of every combination of two labels for overlap. Another expression for halting criteria variables is collision scores and priority ranges, as shown in FIG. 10 , step 590 . The above-described logic is further shown in the following pseudo-code with comments: PULL IN THE LABELS FROM THE EDGES OF THE MAP ROUTINE //Pseudo-code for the Initialization of the Anti-collision Procedure for Maps //List of pseudo-code variables previous_collision_score - the collision score from the previous iteration previous_previous_collision_score - the collision score from two iterations ago iteration_count - number of times the anti-collision procedure has looped slow_change_count - number of iterations of continuous slow change of collision score oscillation_count - number of iterations of continuous oscillation of collision score priority_of_most_important_label - numerical priority value of the most important label priority_range - the difference between the priority of the least and the most important labels. This number is non-negative. frac_inside - fraction of label inside the map boundaries map_x_size - the number of x units in the map - map boundary is a rectangle map_y_size - the number of y units in the map - map boundary is a rectangle (xMove2D, yMove2D) - the label movement if the label qualifies for movement completely inside the map boundary and the label parameters specify 2D type movement (xMoveVec[], yMoveVec[]) - an array of label movements if the label qualifies for movement completely inside the map boundary and the label parameters specify vector type movement (xc, yc) - center point of a cell formed from a grid within the circumscribing rectangle around the label (x_IP, y_IP) - a point satisfying various conditions used to properly move a label completely inside the map boundary LABEL_TOO_MUCH_OUTSIDE_PORTRAIT - indicates if the procedure has determined that the label has much area outside the map boundary or can not be properly moved to a new position completely inside the map boundary. This is a flag of every label set by the procedure. LABEL_OUTSIDE_PORTRAIT - Not used. This is a flag of every label set by the procedure. LABEL_MOVED_INTO_PORTRAIT - indicates if the procedure has moved a label that was originally partially outside the map boundary to a new position completely inside the map boundary. This is a flag of every label set by the procedure. LABEL_MIN_FRACTION_INSIDE - minimum fraction of the label that must be inside the map boundary to attempt relocation completely inside the map boundary. This is a parameter of every label set by caller. LABEL_NEW_LOCATION - A vector (x, y) which is added to all vertices of a label if the procedure moves the label. This vector has an initial value of (0, 0) . This is a parameter of every label determined by the procedure. // pseudo-code also has: // a list of possible label movement candidates to pull the label inside the map boundary // a data structure map of labels and their properties sorted by priority from the most // important label to the least important label ------------------------------------------------------------ // THIS IS THE START OF ROUTINE 10 // The labels are not in any particular order at this point. // They are only in the order in which they are received from the caller. for i = first unordered label to last unordered label  set label i flag LABEL_OUTSIDE_PORTRAIT = FALSE  set label i flag  LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = FALSE  set label i flag LABEL_MOVED_INTO_PORTRAIT = FALSE  set label i parameter LABEL_NEW_LOCATION = (0, 0)  // Determine if the label is inside or outside the map boundary.  // If all vertices are inside, then the entire label is inside.  // Here, a vertex on the map boundary is inside the boundary.  label_inside_map = TRUE  for j = first vertex of label i to last vertex of label i   if ( vertex j outside map boundary ) {    label_inside_map = FALSE   }  next j  if ( label_inside_map = FALSE ) {  // Below, find the approximate fraction of the label inside the map boundary.  // The circumscribing rectangle has edges parallel to the map edges.  // Note that both the rectangle and the label are convex polygons.  Put a circumscribing rectangle around label i  Divide the circumscribing rectangle into 64 units by 64 units forming 4096 cells  in_label = 0  in_label_and_map = 0  for k = first cell to last cell   Find center point of cell k called (xc, yc)   // Here, a point on a label edge or map boundary is inside the label or map.   // Use the “point inside convex polygon” procedure described in the   // labels overlap section.   if( (xc, yc) inside label ) {    in_label ≡ in_label + 1    if( (xc, yc) inside map boundary ) {     in_label_and_map = in_label_and_map + 1    }   }  next k  frac_inside = ( in_label_and_map )/( in_label )  // Move the label inside the map boundary if enough of the label is inside.  // Some of the vertices below may be the same vertex.  (x_low, yL) = coordinates of vertex with lowest x coordinate  (x_high, yH) = coordinates of vertex with highest x coordinate  (xL, y_low) = coordinates of vertex with lowest y coordinate  (xH, y_high) = coordinates of vertex with highest y coordinate  // find the new location for the label  if ( frac_inside > LABEL_MIN_FRACTION_INSIDE  parameter of label i ) {   if ( 2D type movement for label i ) {    (xMove2D, yMove2D) = (0, 0)    // If both conditions are true, the label will not fit into the map.    if ( x_low < 0 ) {     xMove2D = 0 − x_low    }    else if ( x_high > map_x_size − 1 ) {     xMove2D = map_x_size − 1 − x_high    }    // If both conditions are true, the label will not fit into the map.    if ( y_low < 0 ) {     yMove2D = 0 − y_low    }    else if ( y_high > map_y_size − 1 ) {     yMove2D = map_y_size − 1 − y_high    }    // Determine if the label is still within its movement parameters.    // This means has the label moved too far from its original position.    // The original location parameter is never changed. It does not change    // because it is always used for comparison to the new position.    if ( (xMove2D, yMove2D) within label i 2D    type movement parameters ) {    // Determine if the label is still inside the map boundary after movement.    // This is really a test to see if the label is too big to fit in the map.    // Here, a vertex on the map boundary is not outside the map.    // This test works because both label and map are convex polygons.    for j = first vertex of label i to last vertex of label i     label_moved_outside_map = FALSE     if ( ( vertex j + (xMove2D, yMove2D) ) of label i is outside map boundary ) {       label_moved_outside_map = TRUE     }    next j    if ( label_moved_outside_map = FALSE ) {     set label i flag LABEL_MOVED_INTO_PORTRAIT = TRUE     set label i parameter     LABEL_NEW_LOCATION = (xMove2D, yMove2D)    }   }  }  else { // vector type movement   count = 0   // If both conditions are true, the label will not fit into the map.   if ( x_low < 0 ) {    find a point (x_IP, y_IP) which meets the following requirements     contained by a line parallel to the vector type movement     contained by a the line x = 0     contained by a line also containing (x_low, yL)    if ( (x_IP, y_IP) exists ) {     xMoveVec[count] = x_IP − x_low     yMoveVec[count] = y_IP − yL     place in list of possible label movement candidates     count = count + 1    }   }   else if ( x_high > map_x_size − 1 ) {    find a point (x_IP, y_IP) which meets the following requirements     contained by a line parallel to the vector type movement     contained by a the line x = map_x_size − 1     contained by a line also containing (x_high, yH)    if ( (x_IP, y_IP) exists ) {     xMoveVec[count] = x_IP − x_high     yMoveVec[count] = y_IP − yH     place in list of possible label movement candidates     count = count + 1    }   }  // If both conditions are true, the label will not fit into the map.   if ( y_low < 0 ) {    find a point (x_IP, y_IP) which meets the following requirements     contained by a line parallel to the vector type movement     contained by a the line y = 0     contained by a line also containing (xL, y_low)    if ( (x_IP, y_IP) exists ) {     xMoveVec[count] = x_IP − xL     yMoveVec[count] = y_IP − y_low     place in list of possible label movement candidates     count = count + 1    }   }   else if ( y_high > map_y_size − 1 ) {    find a point (x_IP, y_IP) which meets the following requirements     contained by a line parallel to the vector type movement     contained by a the line y = map_y_size − 1     contained by a line also containing (xH, y_high)    if ( (x_IP, y_IP) exists ) {     xMoveVec[count] = x_IP − xH     yMoveVec[count] = y_IP − y_high     place in list of possible label movement candidates     count = count + 1    }   }   // Can have zero, one, or two possible label movement candidates   for k = 0 to (count − 1)   // Determine if the label is still within its movement parameters.   // This means has the label moved too far from its original position.   // The original location parameter is never changed. It does not change   // because it is always used for comparison to the new position.   move_distance = magnitude of (xMoveVec[k], yMoveVec[k])   if ( move_distance within label i vector type movement parameters ) {   // Determine if the label is still inside the map boundary after movement.   // This is really a test to see if the label is too big to fit in the map.   // Here, a vertex on the map boundary is not outside the map.   // This test works because both label and map are convex polygons.   for j = first vertex of label i to last vertex of label i       label_moved_outside_map = FALSE       if(( vertex j + (xMoveVec[k], yMoveVec[k])) of label i is outside map boundary) {        label_moved_outside_map = TRUE       }      next j      if ( label_moved_outside_map = FALSE ) {       set label i flag       LABEL_MOVED_INTO_PORTRAIT = TRUE       set label i parameter       LABEL_NEW_LOCATION = (xMoveVec[k], yMoveVec[k])       break out of loop // go past next k      }      }     next k    } // end of vector type movement   }   if ( label i flag LABEL_MOVED_INTO_PORTRAIT = FALSE ) {    set label i flag    LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE   }  } // end if label_inside_map = FALSE next i // THIS IS THE START OF ROUTINE 20 // Sort the labels by priority. // The labels with the highest priorities have the lowest numbers. // Priorities may be negative numbers. // Labels may have the same priority. // After this loop, assume all labels are ordered properly. Sort labels by priority from the most important label to the least important label  and place into a data structure map // THIS IS THE START OF ROUTINE 30 // Initialize halting criteria variables priority_range = priority_of_least_important_label − priority_of_most_important_label // initialize these two variables to large numbers previous_collision_score = Very Large Number previous_previous_collision_score = Very Large Number iteration_count = 0 slow_change_count = 0 oscillation_count = 0 There is a process for comparing labels for overlap that is used several times in this invention. A list of labels has been previously sorted in order of priority, routine 20 , where the highest priority label is first on the list. The order of labels with the same priority is interchangeable with among themselves. Starting with the highest priority label, it is compared against every label below it on the list from the second label to the last label in order of priority. Next, starting with the second highest priority label, it is compared against every label below it on the list from the third label to the last label in order of priority. Continuing the process, label n is chosen and compared to every label below it on the list from label n+1 to the last label in order of priority, until the process is exhausted. In this manner, every unique pair of labels is compared in order of priority. This process for the purposes of this application is termed cycling through label pairs. Referring to FIGS. 7 a and 7 b , labels are compared to determine if they overlap (routine 40 ). The number of labels and the maximum numerical difference between the highest and lowest priority labels is determined in step 400 . All labels are grouped according to priority in steps 403 , 406 , 409 , and 412 . It is important to choose the order of comparison properly to avoid excessive calculation and moving labels more times than necessary. Steps 415 , 421 , 424 , 427 , 430 , 436 , and 442 perform cycling through label pairs. If either member of a unique pair obtained by each iteration of the cycling will not be drawn on the map for any reason, steps 433 and 439 continue to the next pair of labels avoiding unnecessary testing with the label that will not be used. Step 445 , which corresponds to routine 45 , tests for overlap between the members of the pair. Step 448 , which corresponds to routine 50 , performs the movement procedure on one of the labels if they overlap. Step 418 exits routine 40 and proceeds to routine 60 , an evaluation function procedure. The above-described logic is further shown in the following pseudo-code with comments: Order of Comparison for the Label Overlap Test Routine // The n labels have already been sorted in priority order, // from the most important, label 0, consecutively, // to the least important, label (n − 1). LABEL_TOO_MUCH_OUTSIDE_PORTRAIT - indicates if the procedure has determined that the label has much area outside the map boundary or can not be properly moved to a new position completely inside the map boundary. This is a flag of every label set by the procedure. LABEL_OUTSIDE_PORTRAIT - Not used. This is a flag of every label set by the procedure. LABEL_MOVED_INTO_PORTRAIT - indicates if the procedure has moved a label that was originally partially outside the map boundary to a new position completely inside the map boundary. This is a flag of every label set by the procedure. last_Label_Index = number_of_labels − 1; // zero based // Zero based. // The highest priority is zero and the lowest priority is a number greater than zero. // Note that there may be priorities which have no labels. last_Pri = lowest priority − highest priority; // which equal the lowest priority // Below, if there are no labels with priority p, // first_Pri[p] = −1 and last_Pri[p] = −1 // first_label[p] = first label index with priority p // last_label[p] = last label index with priority p for p = 0 to last_Pri; // highest priority to lowest priority  if labels with priority p exist   first_label[p] = most important label with priority p;   last_label[p] = least important label with priority p;  else   first_label[p] = −1;   last_label[p] = −1; next p; for i_pri = 0 to last_Pri; // highest priority to lowest priority  if first_label[i_pri] = −1, continue to next i_pri;  for j_pri = i_pri to last_Pri; // highest priority to lowest priority   if first_label[j_pri] = −1, continue to next j_pri;   for i_idx = first_label[i_pri] to last_label[i_pri];   if i_idx flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR       LABEL_OUTSIDE_PORTRAIT = TRUE, continue to next i_idx    for j_idx = first_label[j_pri] to last_label[j_pri];     // Do not compare a label to itself or     // compare labels which have been previously compared,     // for this particular iteration of the entire algorithm.     if i_idx <= j_idx, continue to next j_idx;     if j_idx flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR       LABEL_OUTSIDE_PORTRAIT = TRUE, continue to next j_idx     if label i_idx overlaps label j_idx,      then perform the label movement procedure on label j_idx;    next j_idx;   next i_idx;  next j_pri; next i_pri; All labels are restricted to convex planar polygons in the plane of the map. A planar polygon is convex if it contains all the line segments connecting any pair of its points. If two convex planar polygons overlap, this means that: 1) at least one vertex of one polygon is inside the other polygon, or 2) at least one edge of one polygon intersects an edge of the other polygon. Routine 45 , shown in FIG. 8 , is a label overlap test procedure. The overlap test has three parts. First, it determines if any vertex of the first polygon is inside the second polygon, step 462 . Second, it determines if any vertex of the second polygon is inside the first polygon, step 466 . Third, it determines if any edge of the first polygon intersects any edge of the second polygon, step 470 . Once any vertex is found to be inside the other polygon, there is no need to test remaining vertices and edges. Once any edge is found to intersect any edge of the other polygon, there is no need to test remaining edges and vertices. Prior to the overlap test, routine 45 begins by receiving two labels from caller in step 450 . In step 454 , the maximum and minimum x and y values for each label are determined. These x and y values form circumscribing rectangles, whose edges are parallel to the map's x axis and y axis, for each label. In step 458 , the circumscribing rectangles for each label are compared. If these circumscribing rectangles do not overlap, then routine 45 returns “no overlap” to the caller in step 478 . FIG. 8 shows the test for whether a vertex of a polygon is inside another polygon. Consider the standard right-handed two-dimensional Cartesian coordinate system with the positive y direction up and the positive x direction to the right. A first polygon's edges are chosen such that the perimeter is traversed in the counterclockwise (CCW) direction (the perimeter may be traversed in a clockwise direction so long as it is done consistently). At step 462 , if any vertex of a second polygon is to the left of all edges of the first polygon, then that vertex is inside the first polygon. Likewise, at step 466 , if any vertex of the first polygon is to the left of all edges of the second polygon then that vertex is inside the second polygon. If any vertex of a polygon is inside another polygon, then the polygons overlap. This is the test for a point being inside a convex planar polygon. Lines containing the edges that make up a polygon may be written, ( y−Y 1)( X 2− X 1)−( x−X 1)( Y 2− Y 1)=0 where (x,y) is any point on the line, and (X1,Y1) and (X2,Y2) are the endpoints of an edge of the polygon under test. Points lying on the polygon edges satisfy the line equations, while points not on the polygon edges do not satisfy those equations. If (x, y) is any point in the plane, the equation for a line containing an edge is: ( y−Y 1)( X 2− X 1)−( x−X 1)( Y 2− Y 1)= K where K is a real number constant. Then, for all points to the left of any edge, K>0, and for all points to the right of any edge, K<0. Note that point 2 in the above equation is at the head of the vector representing the edge and point 1 is at the tail of the vector representing edge. This is true because, for all edges pointing to the right, (X2−X1)>0. For any point above the line containing the edge, (x_above, y_above), there exists a point, (x,y), on the line, such that: x_above=x and y_above>y Therefore: ( y - Y1 ) ⁢ ( X2 - X1 ) - ( x - X1 ) ⁢ ( Y2 - Y1 ) = ( y - Y1 ) ⁢ ( X2 - X1 ) - ( x - X1 ) ⁢ ( Y2 - Y1 ) ( y_above - Y1 ) ⁢ ( X2 - X1 ) - ( x - X1 ) ⁢ ( Y2 - Y1 ) > ( y - Y1 ) ⁢ ( X2 - X1 ) - ( x - X1 ) ⁢ ( Y2 - Y1 ) ( y_above - Y1 ) ⁢ ( X2 - X1 ) - ( x_above - X1 ) ⁢ ( Y2 - Y1 ) > ( y - Y1 ) ⁢ ( X2 - X1 ) - ( x - X1 ) ⁢ ( Y2 - Y1 ) A point that is above a line pointing to the right is a point that lies to the left of the line. Similar arguments show that any point on the left of lines pointing up, pointing down, or pointing left yields a positive value with substituted into the line equation. Step 470 tests whether the edges of one polygon intersect another polygon. Consider the equations of the lines that contain the edges of the first polygon and the equations of the lines that contain the edges of the second polygon. Determine the intersection point for every two-line combination, where one line is a line that contains an edge of the first polygon and the other line is a line that contains an edge of the second polygon. If the intersection point lies on or between the endpoints of the polygon edges, then the edge of one polygon intersects the edge of the other polygon and the polygons overlap. In cases where the lines are parallel, and not coincident, no intersection point exists for that pair of lines. If the lines are coincident, then the edges may or may not touch, but if the edges touch then the polygons overlap. If the three above overlap tests, at step 462 , step 466 , step 470 , find an overlap between the two labels, then routine 45 returns “labels overlap” to the caller in step 482 , step 486 , and step 490 , respectively. If after performed the three tests, there is no overlap between the two labels, then routine 45 returns “no overlap” to the caller in step 474 . The above-described logic is further shown in the following pseudo-code with comments: Pseudo-code for the Overlap Test of Convex Planar Polygons List of pseudo-code variables  (x_2_i, y_2_i) - vertex i of polygon 2  (X1_j, Y1_j) - vertex 1 of edge j of polygon 1  (X2_j, Y2_j) - vertex 2 of edge j of polygon 1  (x_IP, y_IP) - intersection point of lines containing edges x_max_i - max x of edge i y_min_j - min y on edge j find max x, max y, min x, min y on polygon 1 - each will be on a vertex find max x, max y, min x, min y on polygon 2 - each will be on a vertex // if any expression is true, the polygons do not overlap, so return false if (min x of polygon 1 >= max x of polygon 2) RETURN NO_OVERLAP if (min x of polygon 2 >= max x of polygon 1) RETURN NO_OVERLAP if (min y of polygon 1 >= max y of polygon 2) RETURN NO_OVERLAP if (min y of polygon 2 >= max y of polygon 1) RETURN NO_OVERLAP // if any vertex of polygon 2 is inside polygon 1, the result is greater than zero. // proceed around polygon 1 in the CCW direction for each vertex of polygon 2 for i = first vertex of polygon 2 to last vertex of polygon 2  inside = TRUE  for j = first edge of polygon 1 to last edge of polygon 1 in CCW direction   if((y_2_i − Y1_j) (X2_j − X1_j) − (x_2_i − X1_j) (Y2_j − Y1_j) <= 0) inside = FALSE  next j  if (inside = TRUE), RETURN OVERLAP next i Repeat the above, except test polygon 1 vertices with polygon 2 edges Return OVERLAP if appropriate // perform the edge intersection test for i = first edge of polygon 1 to last edge of polygon 1  of the two endpoints of edge i, get x_max_i, y_max_i,  x_min_i, y_min_i  for j = first edge of polygon 2 to last edge of polygon 2   of the two endpoints of edge j, get x_max_j, y_max_j, x_min_j, y_min_j   solve for intersection point, (x_IP, y_IP), of lines containing edge i and edge j   if intersection point exists    // An intersection at an endpoint is an overlap.    // These tests also take care vertical and horizontal edges.    if (x_IP <= x_max_i and x_IP >= x_min_i) and     (y_IP <= y_max_i and y_IP >= y_min _i) and     (x_IP <= x_max_j and x_IP >= x_min_j) and     (y_IP <= y_max_j and y_IP >= y_min_j),     RETURN OVERLAP  next j next i RETURN NO_OVERLAP Labels must be moved about the map to clear existing label collisions. After it is determined that two labels overlap, routine 50 ( FIGS. 9 a , 9 b , and 9 c ) finds several new locations for the lower priority of the two labels that eradicate the existing overlap. The higher priority label is a first label while a lower priority label is a second label. These locations are ranked by how far the second label must be moved, shortest to longest. The actual location finally selected must meet the following criteria: 1) the second label moves a shorter distance than other qualifying locations; 2) the second label movement does not result in overlap with another label (or labels) of equal or higher priority than the first label; 3) the second label movement does not exceed the maximum movement parameters for that particular label; and 4) no part of the second label is moved outside the map boundary. If no candidate locations meet these criteria, the second label is not moved. During the process of fixing existing collisions, other collisions may be created. New collisions are only allowed if it reduces collisions among labels with priorities equal to or higher than the first label. As the procedure iterates, new collisions are handled like the original collisions. The procedure will minimize collisions. Each label may be moved in one of two ways. A caller selects the type of movement of a label to the exclusion of the other type of movement. First, a label may move in any direction on the map, up to a maximum distance from the original location. This is referred to as 2D type movement. Second, a label may move parallel to a vector up to a maximum distance from the original location in the positive vector direction or the negative vector direction. This is referred to as vector type movement that may be used for linear features such as highways and rivers. Both the vector and the maximum distances are in the label's parameter list. Labels on a map may consist of any mixture of 2D movement and vector movement types. However, higher priority labels must be examined before lower priority labels regardless of movement type. Prior to the attempted label movement, routine 50 begins by receiving two labels from caller in step 500 . Routine 50 cycles through the edges of first label in step 503 and cycles through the vertices of second label in step 509 . A counter is set in step 506 . The first label's edges are traversed in a CCW direction. Remembering that these operations take place on a two dimensional map, step 512 tests whether each vertex of the second label is left of a line containing an edge of the first label when the first label is traversed in a CCW direction. A vertex of the second label is said to be on a label side of the line containing the edge of the first label if the vertex of the second label and area of the first label are on the same side of the line containing the edge of the first label. Note that these labels are restricted to convex polygons so all of one label will be on one side of the line containing the label's edge and no part of the label will be on the other side of the line. Likewise, a vertex of a second convex polygon is said to be on a convex polygon side of a line containing an edge of a first convex polygon if the vertex of the second convex polygon and area of the first convex polygon are on the same side of the line containing the edge of the first convex polygon. If step 515 specifies a 2D type movement, then step 518 finds an intersection of two lines. A first line is the line that contains one edge of the first label. A second line is perpendicular the first line and contains the vertex. If, instead, step 515 specifies a vector type movement, then step 521 finds an intersection of a line containing an edge and a line parallel to the vector type movement also containing the vertex. If in either the 2D type movement case or the vector type movement case, an intersection exists, step 524 , and the vertex is on the label side as defined above, step 527 calculates a first vector from the vertex to the intersection. If the first vector is too small, step 530 , then the routine 50 calculates, in steps 533 , 536 , and 539 , a second vector with desirable properties listed in steps 536 and 539 . In the case that the first vector is too small, the first vector is replaced by the second vector. Whichever vector remains, it is hereafter referred to as the vector. Step 542 tests whether the vector is within movement bounds from the original label location. If at step 545 , it is within bounds, the vector is placed on an end of a list of qualified vectors and a length of the vector is placed on an end of a length list. Once all vertices of the second label are tested, if there any qualified vectors (step 548 ), then, at step 551 : 1) Find the maximum length in the length list and a corresponding qualified vector from the vector list; 2) Insert the length and the qualified vector into a data structure map that is sorted by distance; and 3) Empty the length list and vector list. After all the edges of the first label are checked, at step 554 the steps starting at step 512 are repeated using the edges of the second label and the vertices of the first label. For any qualifying vectors, a negative of the vector is taken and that vector and its length are inserted into the data structure map. Next, tests are performed to determine if proposed locations for the second label are acceptable. At step 560 , starting with a shortest vector in the data structure map, the second label is moved in both a direction and a length of the shortest vector to obtain a new location for the second label. Then, at step 563 , a test is performed to determine if part of the new location for the second label is outside the map boundary. If, the new location for the second label places part of the second label outside the map boundary, repeat steps 557 , 560 , and 563 , using a next vector from the data structure map. Step 566 retrieves labels with priorities greater than or equal to the first label. In step 569 , if any retrieved label is the first label or the second label, then retrieve the next label in step 566 . At step 572 , the overlap test is performed on the current candidate location for the second label against labels that fail tests at step 563 and step 569 . If there is an overlap, steps 557 through 572 are repeated. Otherwise, the second label is moved to the candidate location in step 575 . After a new location is found for the second label among the proposed locations, or after all proposed locations are determined to be unacceptable, then data structure map is cleared in step 578 , and a next pair of labels is supplied in step 581 . The above-described logic is further shown in the following pseudo-code with comments: Movement Procedure of Convex Planar Polygons // List of pseudo-code variables  (x_2_j, y_2_j) - vertex j of polygon 2  (X1_i, Y1_i) - vertex 1 of edge i of polygon 1  (X2_i, Y2_i) - vertex 2 of edge i of polygon 1  (x_IP, y_IP) - intersection point of lines containing edge and vertex  (X,Y) - vector from vertex to edge pseudo-code also has:  a list of distances  a list of vectors  a data structure map of distances and vectors sorted by distance, short to long // Polygon 1 is the more important polygon and polygon 2 will move if possible // Here, the vertices in a polygon are on the left side of the edge // of the other polygon when traversing it in the CCW direction, // but the vertices are not necessarily inside the other polygon. // That is why all possibilities are caught in the algorithm below - // even where no vertex from either polygon is inside the other. // Do not have to check specifically for the above case. // If a vertex of polygon 2 is on left side a polygon 1 edge, the result is greater than zero. // proceed around polygon 1 in the CCW direction for each vertex of polygon 2 // Note the the vertex in question does not have to be inside polygon 1 for i = first edge of polygon 1 to last edge of polygon 1 in CCW direction  count_of_possible_vertices = 0  for j = first vertex of polygon 2 to last vertex of polygon 2   if((y_2_j − Y1_i)(X2_i − X1_i) − (x_2_j − X1_i)   (Y2_i − Y1_i) > 0)    if (2D type movement for polygon 2)    // a solution will always exist for this case    solve for intersection point, (x_IP, y_IP), of a line containing edge i    and a line perpendicular to edge i containing (x_2_j, y_2_j)   if (vector type movement for polygon 2)   // a solution might not exist for this case   solve for intersection point, (x_IP, y_IP), of a line containing edge i   and a line parallel to the vector type movement containing (x_2_j, y_2_j)   if ( solution exits for (x_IP, y_IP) )    // get vector from vertex to intersection point    (X,Y) = (x_IP − x_2_j, y_IP − y_2_j)    if ( (X,Y) length minute )     if ( 2D type movement for polygon 2 )      find a point (X,Y) which meets the following requirements       on right side of edge i (CCW)       contained by a line perpendicular to edge i       contained by a line also containing (x_IP, y_IP)       a minute distance from (x_IP, y_IP)     else // vector type movement for polygon 2      find a point (X,Y) which meets the following requirements       on right side of edge i (CCW)       contained by a line parallel to the vector type movement       contained by a line also containing (x_IP, y_IP)       a minute distance from (x_IP, y_IP)    // because polygon may move several times, keep the original location of the label    if ( movement of (X,Y) leaves polygon with movement limit )    // Make vector just a bit larger that the distance to the edge    // so when polygon 2 is moved, it moves just outside the polygon 1    length_of_XY = length of (X, Y) * (1.0 + 1.0e−09)    X = X * (1.0 + 10e−09)    Y = Y * (1.0 + 10e−09)    append length_of_XY to end of distance list    append (X,Y) to end of vector list    count_of_possible_vertices = count_of_possible_vertices + 1  next j  if (count_of_possible_vertices > 0)   find the maximum distance in the distance list   get the corresponding vector to this distance from the vector list   insert the distance and the vector into the data structure map sorted by distance,   from the shortest distance to the longest distance   empty distance list and vector list next i Repeat the above, except use polygon 1 vertices and with polygon 2 edges The vector for possible movement, (X,Y), is reversed Insert the results into the same distance/vector data structure map // the outer loop is just going thought the sorted data structure map for i = first location candidate to last location candidate  get new location for polygon by adding vector (X,Y) to each vertex  if ( any part of label outside map boundary ) next i  for j = first label to last label whose priority >= polygon 1   if ( polygon 1 is label j or polygon 2 is label j) next j   if ( polygon 2 in location candidate i overlaps label j ) next i   update polygon 2 location in its parameter list   break out of both for loops  next j next i clear the data structure map get the next pair of labels to be tested for overlap The Evaluation Function, the Halting Criteria; and the Adjustment of Label Properties It is probable that the process of label movement will iterate indefinitely, therefore halting criteria are needed. An evaluation function provides input to a halting procedure to stop the process at an acceptable point. The calculation of the evaluation function is represented by FIG. 11 . All labels that overlap are known at this point. The procedure used to reduce label collisions is an iterative process. A collision score is a variable that measures the severity of collisions of labels in the map. It is initialized to zero in step 600 . Step 605 performs cycling through label pairs. In step 610 , each label of the current pair of labels is tested to see if it has too much of its area is outside the map or if it is completely outside the map. This avoids unnecessary calculation for labels that will not be used. The overlap test (routine 45 ) is performed in step 615 . If no overlap occurs between the two labels being tested, then another unique pair of labels is fetched in step 605 . If overlap occurs, then the collision score is added to the previous collision score in step 620 . The final value of the collision score is attained after all the unique label pairs have been tested. In this anti-collision procedure for maps, the evaluation function at step 620 is: Collision  Score = ∑ ij ⁢ ( ( label ⁢ ⁢ i ⁢ ⁢ adjusted ⁢ ⁢ priority ) 2 + ( label ⁢ ⁢ j ⁢ ⁢ adjusted ⁢ ⁢ priority ) 2 ) where the score is the summation over every pair of overlapping labels. The result of this function is defined as zero if no collisions remain and greater than zero if any collisions remain. The function penalizes disproportionately for collisions involving high priority labels. For instance, a collision involving a high priority label and a low priority label gets a higher score (worse) than a collision involving two medium priority labels. Routine 70 as shown in FIG. 12 evaluates halting criteria to determine if the labels are in optimal locations. The iterative process must halt at some point. A slow change halting criteria is evaluated in step 700 . If the slow change per iteration in the collision score occurs, the slow change count is incremented by one in step 705 . If the slow change per iteration does not occur, the slow change variable is reset to zero in step 710 . A short-term oscillation halting criteria is evaluated in step 715 . If the short-term oscillation in the collision score occurs, the short-term oscillation count is incremented by one in step 720 . If the short-term oscillation does not occur, the short-term oscillation count is reset to zero in step 725 . The previous values of the collision score are stored in step 730 . Step 730 also increments the iteration count by one. Here, an iteration is one cycle of the anti-collision algorithm that includes routines 40 , 45 , 50 , and 60 . Example rules tested at step 735 to halt the procedure follow: 1) the evaluation function is below a minimum value; 2) the number of iterations is greater than a maximum value; 3) the evaluation function changes less than a minimum percentage of the previous iteration for more than a set number of iterations; and 4) the evaluation function oscillates for more than a set number of consecutive iterations. If none of these conditions are meet, the anti-collision algorithm is repeated in step 740 , noting that labels may move several times before the iterations stop. A label's new position is stored in its parameter list at the time a label is moved. The original position is always available in the label's parameter list. Routine 80 , as shown in FIG. 13 , adjusts label properties. At this point, labels will not be moved because the halting criteria have been satisfied. However, some labels may still overlap. Routine 80 begins in step 800 by setting the DRAW flag to TRUE for every label. Step 805 cycles through all unique pairs of labels. In step 810 , each label of the current pair of labels is tested to see if it has too much of its area is outside the map or if it is completely outside the map. This avoids unnecessary calculation for labels that are not used. Labels that have some or all of their area outside the map have their DRAW flag set to FALSE in step 815 . The overlap test (routine 45 ) is performed in step 820 on those label pairs for which neither have any area outside the map. If no overlap occurs between the two labels being tested, then another unique pair of labels is fetched in step 805 . If overlap occurs, then the MUST DRAW flags for both labels are examined in steps 825 , 830 , and 835 . Depending on the result of this examination, the DRAW flag for one of the current labels is set to FALSE in step 840 and step 845 . These flags are in the label's parameter list. The MUST DRAW flag is set by the caller. If the DRAW flag is true, this procedure will draw the label. If the DRAW is false, this procedure will not draw the label. For any pair of overlapping labels, the following somewhat arbitrary rules determine the final state of a label's DRAW flag: 1) If one label has MUST DRAW=TRUE, that label sets DRAW=TRUE, and the second label sets DRAW=FALSE. 2) If both labels have MUST DRAW=TRUE, the label higher on the list of label priority sets DRAW=TRUE, and the other label sets DRAW=FALSE. Note that this will hold for labels of equal priority. 3) If neither label has MUST DRAW=TRUE, the label higher on the list of label priority sets DRAW=TRUE, and the other label sets DRAW=FALSE. Note that this will hold for labels of equal priority. The label priority list and the overlap test are described in preceding sections of the description of the entire anti-collision procedure. After label properties are adjusted, control is returned to the caller, in step 900 of FIG. 14 . The above-described logic is further shown in the following pseudo-code with comments. List of pseudo-code variables collision_score - the sum of the evaluation function after each iteration previous_collision_score - the collision score from the previous iteration previous_previous_collision_score - the collision score from two iterations ago iteration_count - number of times the anti-collision procedure has looped slow_change_count - number of iterations of continuous slow change of collision score oscillation_count - number of iterations of continuous oscillation of collision score priority_of_most_important_label - numerical priority value of the most important label priority_range - the difference between the priority of the least and the most important labels. This number is non-negative. adjusted_priority_1 - the label 1 priority modified to make it work in the evaluation function // Evaluation Function ----------------------------------------------- collision_score = 0 // these loops go thought label priority list for i = first label to last label  if( label i flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR   label i flag LABEL_OUTSIDE_PORTRAIT = TRUE ) next i  for j = label i+1 to last label   if( label j flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR    label j flag LABEL_OUTSIDE_PORTRAIT = TRUE ) next j   if( label i and label j overlap )   {  // Adjust the label priorities to make the evaluation function work properly.  // Note that the highest priority labels are assigned the lowest numbers and  // priorities may be positive or negative.  adjusted_priority_1 = 1 + priority_range −       ( label_1_priority − priority_of_most_important_label )  adjusted_priority_2 = 1 + priority_range −       ( label_2_priority − priority_of_most_important_label )  collision_score = collision_score +       (adjusted_priority_1) * (adjusted_priority_1) +       (adjusted_priority_2) * (adjusted_priority_2)  }  next j next i // Halting Algorithm --------------------------------------- // is there slow change ? if(collision_score <= previous_collision_score AND  collision_score > 0.98*previous_collision_score) {  slow_change_count = slow_change_count + 1 } else {  slow_change_count = 0 } // is there oscillation ? if( (collision_score > previous_collision_score AND  previous_collision_score < previous_previous_collision_score ) OR  (collision_score < previous_collision_score AND  previous_collision_score > previous_previous_collision_score ) ) {  oscillation_count = oscillation_count + 1 } else {  oscillation_count = 0 } iteration_count = iteration_count + 1 previous_previous_collision_score = previous_collision_score previous_collision_score = collision_score if(collision_score = 0) goto ADJUST_LABEL_PARAMETERS if(iteration_count > 20) goto ADJUST_LABEL_PARAMETERS if(slow_change_count > 4) goto ADJUST_LABEL_PARAMETERS if(oscillation_count > 6) goto ADJUST_LABEL_PARAMETERS goto Start of Next Iteration ADJUST_LABEL_PARAMETERS: //------------------------------------------- // set label flag DRAW = TRUE for all labels for i = first label to last label  label_i_DRAW = TRUE  next i // these loops go thought label priority list and set the draw flag for i = first label to last label  if( label i flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR   label i flag LABEL_OUTSIDE_PORTRAIT = TRUE )  {   label_i_DRAW = FALSE   next i  }  for j = label i+1 to last label   if( label j flag LABEL_TOO_MUCH_OUTSIDE_PORTRAIT = TRUE OR     label j flag LABEL_OUTSIDE_PORTRAIT = TRUE )   {    label_j_DRAW = FALSE    next j   }   if( label i and label j overlap )   {    if ( label_i_MUST_DRAW = TRUE AND label_j_MUST_DRAW = TRUE )    {     label_j_DRAW = FALSE    }    else if ( label_i_MUST_DRAW = TRUE )    {     label_j_DRAW = FALSE    }    else if ( label_j_MUST_DRAW = TRUE )    {     label_i_DRAW = FALSE    }    else    {     label_j_DRAW = FALSE    }   }   next j next i return to caller While the particular SYSTEM AND METHOD FOR LABELING MAPS as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular means “at least one”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims.

A system and method for label placement is disclosed that achieves the twin goals of practical efficiency and high labeling quality by employing cartographic heuristics. A caller defines map and label properties. Then labels are pulled within a map boundary. Labels are next ordered by priority in descending importance. The order of testing labels is determined. Attempts are made to move overlapping labels. This is an iterative process; therefore there must be criteria that halt the procedure. Upon reaching an acceptable solution, the label properties are adjusted to reflect the new label placements.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to digital watches and in particular to a method for manufacturing and assembling a low-cost electronic watch and the resulting structure. 2. Prior Art One of the problems in the volume manufacture of electronic watches is to obtain as low a manufacturing cost as possible commensurate with quality and aesthetic standards. Various structures and methods have been proposed to do this. For example, in co-pending patent application Ser. No. 788,866 filed Apr. 19, 1977 entitled "LOW COST WATCH CASE", on an invention of Schneider and Wickwar, assigned to the assignee of this application, an integral watch case and band is disclosed which comprises one way of achieving this goal. A switch means is provided as an integral part of the case sidewall for selectively actuating certain functions in the watch. SUMMARY OF THE INVENTION This invention provides another structure for achieving a low-cost electronic watch (either digital or analog) while at the same time meeting the high standards of quality and aesthetic appearance demanded by the consumer. According to this invention, a three-part watch case means comprises a top means containing lens means formed in the center portion thereof and first lock means formed in the peripheral portions thereof; flexible band means containing a centered region with a center hole therein of a size sufficient to allow the insertion and passage of a watch module and battery, and containing in the periphery of said centered region selected holes in alignment with said first lock means in said top portion, and optionally containing as an integral part thereof at least one portion of the periphery of said centered region adapted to function as a push pin, and bottom means containing a recessed portion for receipt of a watch module and battery and containing in the outer periphery second lock means adapted to mate with the first lock means in the top means through the holes in said band means, wherein said structure in combination comprises a watch case means with band means adapted both to function as a gasket between said top means and said bottom means and as the band holding said watch case means on the arm of the user. The structure of this invention is particularly adapted for use as the case of a digital watch but can also be adapted for use with a conventional watch movement if desired. As a feature of this invention, the flexible band means functions both as a water resistant gasket and the watch band. In addition, the band means can contain a push pin formed integrally from a portion of the band material directly adjacent a switch formed in the watch module. A watch module particularly suited for use with the watch case of this invention with the integral push pin is described in co-pending patent application Ser. No. 711,016 filed Aug. 9, 1976 on an invention of Duff et al entitled: "STRUCTURE AND METHOD OF MAKING A LOW COST SHOCK RESISTANT WATCH", and assigned to Fairchild Camera and Instrument Corporation, the assignee of this application. As disclosed in that application, the use of a module function switch of the type there described makes possible the use of electrically nonconductive material for the push button activating the function switch in the module. This commensurately reduces the cost of the material in the button and the cost of fabricating and assembling the button into the finished watch. DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view of one possible watch assembled in accordance with the method of this invention to yield the structure of this invention; FIG. 2 shows a cross-sectional exploded view of the structure of FIG. 1; and FIG. 3 shows a perspective exploded view of the structure shown in FIG. 1. DETAILED DESCRIPTION FIG. 1 shows a typical watch 10 possessing the structure of this invention and constructed in accordance with the method of this invention. Watch 10 comprises a top means or bezel 20 of any desired aesthetic appearance in which is inserted a lens 30. When used with a digital watch, typical lens 30 comprises a clear transparent portion 30a through which the digits in the watch module can be read and an opaque portion 30b formed either by joining a metal plate to the back surface of the transparent lens or by silk screening the desired pattern onto the back surface of the lens. Of course any other appropriate method of forming the desired pattern on the lens can be used as desired. When used with an analog watch, lens 30 is usually clear. As a feature of this invention, band 40 is formed as an integral part of the watch case. Peripheral portions 40b and 40c of the center region of the band (the "center region" of the band comprises that portion of the band directly beneath bezel 20) are formed such that their exterior shapes have the same outer dimensions as the directly adjacent outer portions of the bezel 20. The interior of the center region of the band directly beneath at least part of the lens portion of bezel 20 has an opening formed therein sufficient to allow watch module 60 (of any standard construction but particularly of a construction such as disclosed in above-mentioned co-pending application Ser. No. 711,016) to pass through said opening so as to be properly located within the case. Bottom means 70 (also called the "back"), is of a unique construction particularly adapted for use with the structure of this invention. Case back 70 is formed with a recess 70a in the center portion thereof for receipt of battery 80 and watch module 60. Recess 70a could also receive a conventional watch movement. Peripheral portion 70b has formed on the top surface thereof pin 71-1 through 71-N where "N" is an integer representing the number of pins formed on the periphery of the back 70. In one embodiment, four pins are sufficient and N equals four. Any other desired number of pins can, of course, be used. Pins 71-n (where "n" is any integer between 1 and N) are formed integrally with 70. Typically back 70 is formed by injection molding using a moldable metal such as zamic. Any other metal (such as powdered metal) capable of being injection molded and suitable for use as a watch cause can, of course, be used. Similarly, a plastic material capable of being molded can also be used in place of the metal parts of the case. The pins or lugs 71-n protruding from the pheripery of the back are formed with a taper such that when a lug 71-n is inserted into a corresponding hole formed in the periphery of bezel 20, the lug locks firmly in this hole preventing bezel 20 from being removed from back 70 except by use of a special tool. While pins 71 are shown formed as part of back 70 these pins could alternatively be formed as part of bezel 20 and holes 21-n could be formed as part of back 70 instead of in bezel 20, as shown. Band 40 has holes 44-1 through 44-N (corresponding to the lugs 71-1 through 71-N) formed in the portions of the band directly above back 70 and beneath bezel 20. During the assembly of the structure (as shown in exploded view in FIG. 3), holes 44-n are located in alignment with lugs 71-n. Lugs 71-n are then inserted into corresponding holes 21-n formed in the adjacent surface of bezel 20. FIG. 2 shows in cross-section the exploded view of the components shown assembled in FIG. 1 and in perspective exploded view in FIG. 3. As shown in FIG. 2, lugs 71-n insert directly into openings 21-n formed in the bottom surface of bezel 20. Lugs 71-n have a taper such that these lugs lock in holes 21-n. A particular feature of this invention is that the center region (including peripheral regions 40b and 40c) of the band 40 located between back 70 and bezel 20 functions not only as a water resistant gasket but, if desired, as least one portion of this center region can also function as a push pin. This portion (shown in FIG. 3), comprises a protuberance 40a extending beyond the side of bezel 20 and back 70 together with indentations 41a and 41b formed from the interior opening 42 into the side 40c of the band material. These indentations give to that portion of material 43 between the indentations 41a and 41b an improved flexibility for lateral movement. In addition the interior point of material 43 extends into the opening 42 beyond the normal perimeter of this opening to make touch contact with the switch 63 on the side of module 60. Slight pressure on the protuberance 40a by the user is sufficient to laterally move point 43 inward (i.e. toward the module 60) a small distance (such as one one hundredth of an inch) to activate the switch 63 on the side of module 60. Of importance, any flexible plastic or other material can be used for watch band 40. Band 40 (other that that portion which comprises part of the case) is a standard watch band containing openings 41a, 41b and 41c (more openings if desired) which mate with the tongue 42b of buckle 42a. Sleeve 43 then receives the portion of tongue 44 which extends beyond buckle 42a. That portion of band 40 between bezel 20 and bottom 70 also serves as a gasket, making the case of this invention water resistant. The watch module 60 can be either a LED and LCD display or any other kind of display appropriate for use with digital or electronic watches. The lens can be either glass or plastic of any desired color. An electronic module with which this particular case structure is best used is a module having a switch of the type disclosed in application Ser. No. 711,016 wherein the case does not have to serve as an integral part of the electrical circuit connected to the switch. An alternate improvement of this invention eliminates the gasket between bezel 20 and back 70, with the back 70 on the bezel 20 on both containing protrusions suitable for the attachment of a conventional watch band.

A watch case and band in combination comprising a back portion containing on the outer periphery thereof first locking means; a center portion comprising a portion of the band containing therein an opening sufficient in size to allow a watch module to pass therethrough and having in the outer periphery of the band around said opening a plurality of smaller openings in alignment with said first locking means; and a top portion having in the outer periphery thereof second locking means located so as to mate with said first locking means locking through said plurality of smaller openings in said band.

BACKGROUND OF THE INVENTION 1. Technical Field The present invention relates to methods and apparatus for data storage and retrieval particularly, but not essentially, in conjunction with optical disc storage devices. 2. Related Art Recent years have seen a great expansion in the complexity of consumer electronics equipment with several different proprietary and technical standards governing interconnectivity and data storage. In connection with the latter feature, the domestic user has had to put up with using different mechanical and functional configurations of storage device for different types of equipment, such as a VHS cassette for video recording, an audio compact cassette for audio recordings from Hi-Fi equipment, and floppy discs for data storage on personal computers. With the advent of recordable optical discs conforming to unified standards as far as data layout, bit rates etc. are concerned, such discs may (if configured to the particular recording system) replace many of the disparate options, and hence the possibility of a single unified standard, both in terms of physical configuration and data management, may be contemplated for all types of domestic audio/video/data-processing systems. Whilst each specific application will have its own particular requirements, the physical record carriers to be used (whether optical discs or some other device) should increasingly be capable of use with more than just a single system or medium. It is therefore an object of the present invention to provide a scheme for data storage on a medium readable by devices of different functionalities, with not only effective partitioning of files between applications, but also inherent inter-connectivity such as to permit, at least in a limited fashion, handling of files from one application by apparatus effecting a different application. SUMMARY OF THE INVENTION In accordance with the present invention there is provided a storage device containing a memory space to be accessed by a first read/write apparatus, the memory space being partitioned into an array of fragments, at least some of which are read/write accessible by the first apparatus, and containing a contents table for the fragments stored at a predetermined location within the memory space, said table being updateable by said first apparatus; characterised in that at least some fragments are read/write accessible by a second apparatus, to the exclusion of the first apparatus, and the contents table is arranged to indicate for each fragment whether it carries data from the first or the second apparatus or whether it is free and available for use by either. By holding indication in the contents table of the using device/apparatus for each fragment, two file systems may peacefully co-exist in a single storage device, such that unused storage space from one application is not wasted, but instead may be made available to another device which, though physically compatible with the storage device, functions in a different manner to that device initially utilising the storage. The storage device may be in the form of an optical disc, and data written to fragments (which fragments are suitably of a common size) by the first apparatus may comprise digitised audio and/or video material with the contents table entries in respect of those fragments comprising playlists for the material. The above-mentioned second apparatus may be a data processing apparatus (such as a personal computer) for which the contents table may comprise a logical volume descriptor for those fragments available to the second apparatus. In use, one of the above-mentioned first and second apparatuses is suitably assigned precedence such that it may overwrite fragments in the storage device already used by the other. The contents table may include identifiers for fragments used by the first apparatus in a format supported by the second apparatus, whereby the second apparatus is enabled to identify fragment usage of the first apparatus. The present invention also provides a method for formatting memory space in a storage medium to be accessed by a first read/write apparatus comprising the steps of: partitioning the medium into an array of fragments at least some of which are read/write accessible by the first apparatus; and generating a contents table for the fragments and storing the same at a predetermined location within the memory space, said table being updateable by said first apparatus; characterised in that at least some fragments are read/write accessible by a second apparatus, to the exclusion of the first apparatus, and the contents table is arranged to indicate for each fragment whether it carries data from the first or the second apparatus or whether it is free and available for use by either. Further in accordance with the present invention there is provided a data processing apparatus operable to implement the foregoing method, said apparatus comprising means arranged to receive and format the memory space in said storage medium to be subsequently accessed by said data processing apparatus, the formatting means being configured to partition the medium into an array of fragments at least some of which are read/write accessible by the first apparatus, and to generate a contents table for the fragments, store the same at a predetermined location within the memory space, and periodically update the same; characterised in that the apparatus is further arranged to assign at least some of the fragments as read/write accessible by a second apparatus, and to place in the contents table an indication for each fragment whether it carries data from the data processing apparatus or the second apparatus or whether it is free and available for use by either. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments will now be described by way of example only, and with reference to the accompanying drawings in which: FIG. 1 symbolically represents the application of a record carrier embodying the present invention to different types of AV and data processing apparatus; FIG. 2 illustrates differing control layers as applicable when the record carrier of FIG. 1 is accessed by different configurations of reading apparatus; and FIG. 3 illustrates variation in the file management and availability in the stored data on the record carrier of FIG. 1 depending on the functionality of the reading device. DETAILED DESCRIPTION OF THE INVENTION As mentioned above, there is approaching convergence in terms of data storage media for different domestic applications. FIG. 1 illustrates schematically the scenario of a user who wishes to use a single record carrier device (in this and the subsequent description a writable and optically-read disc) 10 . As shown, the user may have available to them different systems including a personal computer (PC) 12 , video disc recorder 14 (coupled with television 16 and digital broadcast set-top box or satellite decoder 18 ), and Hi-Fi system 20 (including a record/playback component 22 for digital audio). In order that the user does not have to use separately formatted (although physically matching) discs for each type of apparatus, a common format has often been sought. Due to the differing requirements of each use, commonality is still a problem: what is sought here is compatibility, such that a user may use a single record carrier 10 in more than one application, for example to record a film from the television, as well as data files from the PC, with each application respecting (i.e. not overwriting or corrupting) the information stored by a different device. In the following, a file system for a recordable optical video disc is described, which disc is compatible with both consumer electronics (CE) devices and personal computers (PC) The requirements for such a disc system may be summarised as follows: 1. Support for AV (or real-time) files, which are visible to the user as play lists, including support for multiple logical streams which can reference the same AV data, and trick play. 2. Support for (PC) data files. 3. Compatibility with multiple platforms. In providing the video disc compatible with both CE and PC applications, certain attributes and functionalities are of specific value to systems biased toward use in one host system in preference to the other. For a CE-biased arrangement, the first disc fragment would be used for the file system data, with other fragments used for AV data. Rather than an arbitrary disc layout (as for PC file systems) a fixed part of the disc would hold a skeleton standard file to reference the data part of the disc. Disc updates would be kept as simple as possible, playlists would be supported, and non-AV data may be supported. For the PC-biased solution, compatibility results from using a predetermined or standardised file format, one example of which is the Universal Disk Format (UDF). UDF is a specification developed by the Optical Storage Technology Association for use in optical storage devices: the specification derives from International standard ISO 13346. In the following example, compliance with UDF is assumed, although it will be recognised that the present invention is not restricted to, nor constrained by, conformance with this standard. Using UDF data structures and using a logical linear address space enables PC files to be read and written on any PC supporting UDF. A special directory structure would be defined for the consumer video disc with support for play lists and other special AV data and fast access to real-time files. Fragments would be aligned on boundaries to avoid fragmentation, file system data structures would be cached to avoid extra disc accesses during real-time operation, and means would be provided for recovery of unwritten caches in case of disaster. Each of the two ‘biased’ solutions above has particular benefits for its intended target but these detract from the general interchangeability we seek. When a video disc is put in a PC it is possible to obtain some free space to implement a UDF logical volume for PC data use. This space is marked unusable for the video disc application. For this, two interfaces are provided to the block device: one via calls to a video disc API, which is available on the CE device as well as on the PC, and another via an UDF logical volume, whose contents can only be accessed if a full-fledged UDF file system implementation is present, as schematically illustrated in FIG. 2 . The video disc application, running on the PC or the CE device, would have a view on the data of the disc, as shown by the right-hand half of FIG. 3 . If, for some reason, there is not enough space on the disc, a user may decide to delete fragments that contain data not related to the video disc application. If the user wants to be selective about what to delete, a UDF implementation needs to be present on the device. The PC using its UDF entrance to the data will have the view shown by the left-hand side of FIG. 3, whilst a device supporting both the video disc API and UDF has the possibility to access both types of data (FIG. 3 as a whole). For full compatibility, the stored AV files are preferably readable and writeable on a PC: by implementing simple editing facilities on a CE device and leaving advanced editing to the PC, this may be implemented via the video disc. With AV and PC data files residing on the same disc, there are two possibilities for manipulating (PC) data files on the CE device, the first of which is the all-or-nothing approach, i.e., it should be possible for a user to delete all non-AV files to make room for a recording. The second possibility introduces selectivity where it is possible for a user to delete specific (PC) data files. Considering what happens if a user puts a virgin disc in a CE device and, later on, decides to use it in a PC as well, as well as the other way round; namely the user puts a virgin disc in a PC and subsequently decides to use it in a CE device. In the former case, there are two options: either a first area (‘fragment O’) is deliberately ignored by the CE device to subsequently allow the PC to simply add the UDF file system, or repartition of the disc is implemented and a UDF part is created on it. In the latter case, either it is necessary for the CE device to offer reformatting of the disc to the user, or the PC is enabled to repartition the disc and create a VDR file system on the PC, in other words the PC makes the disc suitable for CE applications. In terms of complexity, there is a trade-off between complexity of the solutions and required compatibility as discussed above. A full-fledged UDF implementation plus a video disc API on top is more complex than implementing a video disc API on a block device, but a consideration of possible objections to UDF shows that, on balance, its selection is generally justified. From reading the present disclosure, other variations will be apparent to persons skilled in the art. Such variations may involve other features which are already known in the methods and apparatuses for data management and storage and component parts thereof and which may be used instead of or in addition to features already described herein. Although claims have been formulated in this application to particular combination of features, it should be understood that the scope of the disclosure of the present application also includes any novel feature or any novel combination of features disclosed herein either implicitly or explicitlyor any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention. The applicants hereby give notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or any further application derived therefrom.

A file management system is provided which enables the peaceful coexistence of two or more file systems from different applications ( 12,16 ) on the same medium ( 10 ). Available free space can be assigned to each of the file systems. Static partitioning of the medium in fixed sized parts is not necessary, as partition sizes can be dynamically changed.

BACKGROUND OF THE INVENTION The invention relates to a materials carrier in the manner of a support for rods and the like that is self-supporting between its long ends. The long ends are embodied by identical vertical closure walls aligned with one another in the longitudinal direction of the materials carrier; horizontally extending holders protrude from the outside of the closure walls, so that the materials carrier can be set down on spaced horizontal shelf-support arms fastened to vertical posts, and so that the materials can be picked up and transported by a shelf service apparatus. Materials carriers of this type are used for instance in the subject of U.S. Pat. No. 4,778,325, which relates to a storage system for rod-shaped material held in self-supporting carriers for rods and the like, with stacking frames disposed transversely to the direction of the storeroom and aligned with one another in the direction of the storeroom; the stacking frames in the manner of shelf systems are provided with adjacent rows of spaced support arms disposed one above the other, extending in the direction of the storeroom and secured to vertical supports, for the carriers. The storage system also has further shelves, embodied on support arms extending in the direction of the storeroom; rod-like material rests directly on these support arms. This storage apparatus is manipulated by a shelf service apparatus, described in detail in the aforementioned U.S. patent, by means of which both the rod-holding supports and the rod-like material resting loosely in the shelves can be moved to a destination and then either returned to storage, or stored at a new location provided for it. With a view to transporting of the rod-holding supports, the shelf service apparatus has a crane bridge that is movable in and extends crosswise to the storeroom direction and has raisable and lowerable load beams on both ends of the crane outside the shelf systems. Support means, extending crosswise to the storeroom direction and pointing with their free ends toward the stacking frames, are adjustable in the storeroom direction so as to be brought into load-bearing engagement, on both sides of the shelf system gangway, which thus forms the middle position, with the inside of the rod-holding supports, by means of holders protruding from the face ends of the support means. However, for the rod-holding supports, the storeroom apparatus described above enables storage only of one type of material, in relatively large quantities of each material, so that if a great variety of material is to be kept on hand, the storage apparatus occupies considerable space and is suitable only for situations in which large quantities of material are needed. Considering not only this problem, but also the shelves in which the material loosely rests, the vertical spacing between shelves disposed one above the other must inevitably be set for the maximum cross section of material to be stored, so that with material of smaller cross section, the shelves can accordingly not be filled full, so that some of the potential storeroom capacity is wasted. Moreover, with storage systems of the type in question a certain amount of reserve capacity is typically provided for, even though some other location in the factory or the like may suffer a lack of storage capacity for products, such as metal sheets, small iron goods or the like, that are not rod-shaped. OBJECT AND SUMMARY OF THE INVENTION It is therefore an object of the invention to disclose a possibility for increasing the utilization of capacity in a storage apparatus of the above type, both in terms of various cross sections of rod-shaped material to be stored and in terms of the exploitation of reserve space for storing other products that are not in the form of rod-shaped material. With a materials carrier of the above generic type as the point of departure, this object is attained in accordance with the invention in that the closure walls are self-supportingly connected to one another solely by a hollow-profiled girder having parallel vertical walls, and that this girder has carrier elements, oriented toward the space between the closure walls, for detachably fastening supports for the material. By these provisions, a component in the manner of a carrier for rods and the like is created, such that the shelf service apparatus can place the carrier inside the storage system and move it, for instance to a materials retrieval and storage station, in the same manner as a rod-holding carrier of the known type. On the other hand, the materials carrier of the invention makes it possible to attach supports for materials of various kinds to the materials carrier in a detachable and hence adjustable and interchangeable manner, so that with the aid of the materials carrier of the invention, not only small quantities of rod-shaped material, but other materials of various types can be stored. To this end, it may be provided that the closure walls are connected to one another on one of their vertical sides by the girder. In that case, one side of the girder is oriented toward the space between the closure walls, and there has the elements for detachably fastening repositores for the material. In another case, it may be provided that the closure walls are connected to one another in the vicinity of their middle between their vertical sides by the ends of the girder, which is provided on both sides with the elements for detachably fastening supports for the material. It thus, also, becomes possible, for supports that are shorter in the direction of the space between the closure walls, to provide these supports on both sides of the vertical walls of the girder; this simultaneously makes it possible to dispose smaller quantities of material of the same type in the same position on both sides of the vertical wall, so that the shelf service apparatus can approach the carrier from both sides and thus handle the material from both sides. To embody the materials carrier, it is practical for the girder to be embodied as a hollow-profiled metal girder. In this way, the materials carrier can be assembled conventionally and hence easily from conventional basic materials in the form of sheet metal, for instance by welding, so that from the standpoint of its particular form as well, the materials carrier of the invention can be provided in quite various forms; the sole condition to be met is that there be space for accommodating it within the dimensions of the storage sites for the known rod-holding carriers. As for the elements for detachably fastening the material supports, they may be embodied by at least two rows of openings disposed one above the other, with the openings of at least one row, preferably a lower row, having a cross section that tapers toward the bottom. This makes it possible to suspend the material supports from the holes or to fasten them to the vertical wall with screws; in the case of the openings with a cross section that tapers toward the bottom, it is also possible to insert the material supports into the vertical wall in the manner of a bayonet mount, with the aid of bolts having heads. In a further feature of the concept of the invention, it may also be provided that a web closing off the girder at the top is formed on the side of the girder oriented toward the space between the closure walls; it is likewise practical to provide this web with a row of openings. This makes it possible for suitably embodied material supports to be suspended from the top of the web by hooks provided on them; in that case, a further fastening to the girder may also be provided lower down, with the aid of screws. Especially for the primary application, that is, storing rod-like material, it may be provided that the supports on the girder are vertically fastenable posts having support arms extending substantially horizontally into the space between the closure walls. Such supports may each have one or more support arms disposed one above the other, depending on the cross section of the rod-like material to be stored, so that even for storing small quantities of material of different cross sections, still every storage site intended for each rod-holding carrier can be fully utilized. This even makes it possible to provide materials carriers that in the vertical direction span more than one storage site for rod-holding carriers, so that even materials of larger dimensions, such as metal sheets or the like, can be kept on hand. The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary end view of the shelf systems of a storage apparatus; FIG. 2 is a side view of a shelf system for carriers for holding rods or the like, in the system of FIG. 1; FIG. 3 is a perspective view of the materials carrier according to the invention illustrating a bolt insertion opening in a greater detail; FIG. 4 is a partial detailed plan view of the materials carrier of FIG. 3; FIG. 5 is a sectional view taken along the line V--V of FIG. 3 further illustrating an arm support with spaced support arms attached thereto; FIG. 6 is a partial cross-sectional view illustrating the support arms of FIG. 5 connected to the girder of FIG. 1; and FIGS. 7-11 are simplified illustrations of various kinds of supports for the material. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an upper portion of a materials storeroom having stacking frames 1, 2, which have vertical posts 3, 4 at each end with support arms 5, 6. Stacking frames or shelf systems are typically disposed in alignment beside one another in arbitrary numbers in the direction of the plane of the drawing in FIG. 1, which corresponds to the direction of the storeroom; they extend vertically to the plane of the drawing in FIG. 1 and so crosswise to the storeroom direction as shown in FIG. 2; their length downward is arbitrary, to suit the space available in a given situation. Via arms 5 engaging the ends of the shelf systems 1, these shelf systems carry self-supporting carriers, in other words carriers that need no further support between their ends, for holding rods and similar material. To this end, the carriers 7, which are also shown in FIG. 2, have U-shaped holders 8 on their face ends with which they are pushed onto the support arms 5. This is shown here by only one example and is equally applicable to other types of carriers for rod-like material. Opposite the carriers, rods 9 of any material are laid onto the shelves formed by the support arms 6; a plurality of support arms 6 in line with one another or spaced variously apart from one another are provided for each shelf or a shelf system or stacking frame, so that different lengths of material 9 can be carried, as for instance happens when leftover pieces are returned to storage after machining. A pair of rails 10 extending in the direction of the storeroom is carried by the top of the shelf systems 1, 2; a shelf service apparatus generally identified at 11 and described in detail in U.S. Pat. No. 4,778,325 runs on these rails 10. Only the shelf service apparatus support means 31a that are visible in FIG. 2 will be mentioned here; with their aid, the carrier 7 can be lifted from the support arms 5 and transported along the adjoining shelf system gangway 12 (FIG. 1) to some desired location. As can be seen from FIGS. 1 and 2, the carrier 7 of FIG. 1 has a certain size and shape in terms of height and width, determined by the size of the shelves embodied by the support arms 5. In accordance with this size and shape of the carriers 7, a certain quantity of rod-like material can be stored with these carriers. Even if only small quantities of some types of rods are needed, then for the sake of automated handling in the materials storeroom, a separate carrier must be used, which accordingly is not filled very full at all, so that the remaining space in it is necessarily wasted. Similar problems arise for the shelves embodied by the support arms 6, on which the rod-like material 9 rests loosely. In this case, although as FIG. 1 shows, when the materials storeroom is set up a certain amount of attention must be devoted to storing various cross sections of material, nevertheless once these provisions have been made they cannot be changed, and they also are restricted to only a few sizes of shelf, so that as a result, once again only some of the space on each shelf is actually usable. To overcome these problems, the invention provides the materials carrier, the principle of which is illustrated by FIG. 3. This materials carrier has vertical end closure walls 13, 14 at each end that are in alignment with one another and also has holders 15, 16, protruding horizontally outward from the closure wall; in the present instance the holders are joined to make the U-shaped profile 8 described in conjunction with FIGS. 1 and 2. The closure walls 13, 14 are self-supportingly connected to one another, on one of their vertical sides, by a girder 17 having vertical walls 40 and 41; the embodiment of this girder and the disposition of the remaining space leaves room available that would otherwise be occupied by the full cross section of the rod-holding carrier 7 of FIGS. 1 and 2. On the vertical wall 40 facing the space between the closure walls 13, 14, the girder 17 has rows of openings 18, with the aid of which support arms are secured for supporting material, which will be described hereinafter, can be fastened detachably to the vertical wall 17. The girder 17 is positioned within the stacking frame such that the holders 15 and 16 are supported by the support arms 5 on the vertical posts 3, 4. With the holders 15 and 16 supported by the support arms 5 the vertical walls 40 and 41 will be in a vertical position so that the posts 21 with support arms 22 can be secured to the girder 17. Each end of the girder 17 will be supported by vertical posts 3 or 4. As can be seen, the materials carrier of FIG. 3 may be inserted instead of one of the rod-holding carriers 7 into a corresponding shelf; in terms of the view of FIG. 1, one of the vertical walls of the girder 17 is positioned immediately adjacent to the shelf posts 3. FIG. 4 is a fragmentary top view of the materials carrier of FIG. 3, with a support 19 fastened to it; the support will be described in detail hereinafter. FIG. 5 is a sectional view of the materials carrier of FIG. 3, taken along the line V--V of FIG. 3. As this sectional view shows, the girder 17 is embodied as a hollow-profiled girder, which may be made from sheet metal, for instance by welding. The cross section is embodied such that on the side facing the space between the closure walls 13, 14, the vertical wall has a web 20 or an end that extends above an upper wall closure 39 that closes the girder off at the top; as FIG. 3 shows, this web 20 may also be provided with openings 18 to which supports may be attached. The vertical wall including the web 20 may be made as one continuous wall such that the upper end extends beyond the upper wall of the girder. FIGS. 5 and 6 also show that the supports 19 comprises a post 21, which can be fastened vertically on a vertical wall of girder 17; from this post 21, at least one support arm 22, on which material 23 can be received, protrudes horizontally into the space between the closure walls 13, 14 and parallel thereto. The fastening of the post 21 to the vertical wall of girder 17 is effected via the flanged strips 24, 25 and by screws 26, 27 passing through the openings 18 of the web 20. Bolts 28 are also secured in captive fashion farther down in the flanged strips 24 and 25; the bolts are inserted into openings 29 and locked in place there with their terminal heads 30; to this end, the openings 29 have an upper cross section that narrows from the upper circular portion to a narrow downward extending opening which has a size of the diameter of the bolt so that the bolt head will lock behind the narrow opening when moved toward the bottom of the narrow opening, so that the bolts 28 can be hooked into them in the manner of a bayonet mount. In this way, the post 21 can easily be mounted on the vertical wall of girder 17 with the aid of the bolt 28 first, and then finally fastened there with the aid of the screws 26 and 27. As many posts 21 and support arms 22 as desired may be secured along the rail 17 to accommodate short or long rods, etc. FIGS. 7-9 show how the supports, described in detail in conjunction with FIGS. 4-6, for material can be variously equipped with one or more support arms 22 or 31 or 32, disposed one above the other, depending on the diameter and length of the rod-like material 23 or 24 or 25 that is to be stored. This makes it clear that identical as well as reusable material carriers of the kind shown in FIG. 3 can be used for various applications, with optimal utilization of storeroom space, by using materials supports that are structurally simple and can therefore be manufactured inexpensively for an intended application. FIG. 10 shows that with the aid of the materials carrier of the invention, materials other than rod-like materials can be stored as well. In the example shown, sheet-metal carriers 33, 34 are suspended from a vertical wall 40 of girder 17, or otherwise (not shown) secured to it, for instance with screws; storage cases 35, 36 intended for storing small iron parts, for example, can then be mounted on the carriers. FIG. 11, finally, shows one example of a support 37, fastened to a vertical wall of girder 17. The height of these supports spans a plurality of shelves, so that by using these supports 37, even correspondingly large-sized parts, such as metal sheets 38 shown, can be kept on hand. The shelves that are spanned are represented as girders, shown in dashed lines, in the manner of the girders 17, although it will be appreciated that such vertical walls will not be present at those particular spanned positions. The above description of the subject of the invention made in conjunction with FIGS. 3-11 relates solely to a girder 17 having parallel vertical walls that is secured at its ends on one of the vertical sides of the closure walls 13, 14. As already emphasized in the background section, the girder 17 may also be disposed in the vicinity of the middle between the vertical sides of the closure walls 13, 14, and in that case may be provided with suitable elements on its vertical wall 41 for detachably securing material holders. Especially for a materials carrier that has been taken out of the shelf, this makes it possible for the shelf service apparatus or other equipment to handle the material held in it from both sides of the carrier. The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.

A self supporting carrier for rods, flat sheets, etc., comprising spaced end holders which are held in paralellism by a girder formed as a hollow with vertical aides. The ends of the girder are secured to a vertical wall of the end holders which are U-shaped with one horizontal side used to support the carrier on horizontal supports in a storage area. At least one vertical wall of the girder is provided with equaly spaced rows of apertures by which material supports are secured to the at least one vertical wall of the girder to extend outwardly therefrom between the end holders. One of the rows of apertures may be slotted vertically such as a bayonet type holder.

[0001] This application claims the benefit of provisional application Ser. No. 60/562,488 filed on Apr. 15, 2004, which is hereby incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to dew resistant coatings and articles having the dew resistant coating adhered thereto. The dew resistant coatings are useful on articles or surfaces used in outdoor applications and are particularly useful on retroreflective articles. BACKGROUND OF THE INVENTION [0003] There exists a need for imparting dew resistance to transparent substrates such as windshields, lenses, goggles, and windows, and reflective substrates such as mirrors and retroreflective traffic signs. While retroreflective traffic signs currently provide optimum levels of headlight reflectivity to motorists, accumulation of dewdrops on the surface of the retroreflective sign can result in potentially catastrophic “blackouts” in which the signs are ineffective in providing vital information to motorists. This problem has been described by John A. Wagner in the Florida Sate Department of Transportation Report “HPR Research Study M29-82”, October 1989. In certain parts of the world, the climate is such that moisture from the atmosphere readily condenses onto surfaces when the temperature of the surface drops below the dew point, the temperature at which the air is fully saturated with water vapor and below which precipitation of water in the form of “dew” occurs. When formed on the surface of mirrors and retroreflective surfaces, these dewdrops scatter the incident light, resulting in the loss of reflectivity or “blackouts”. [0004] One method of preventing condensation and the formation of dewdrops is to heat the surface of the substrate to a temperature above the dew point. U.S. Pat. No. 5,087,508 describes the use of phase change materials in a thermal reservoir located behind the outer layer of a display sign. The phase change material undergoes at least one phase change, e.g., from liquid to solid state or from one crystalline state to another, between about −20° C. and about 40° C. During periods of falling ambient temperature, the thermal reservoir will yield heat, thereby warming the outer layer of the display sign. European Patent Application 155,572 describes a device for preventing the formation of dew and frost on retroreflective road sign carriers in which a thermal radiator is arranged above and in front of the road sign. Neither of these devices provides a complete solution to the problems associated with the formation of dew. The device of U.S. Pat. No. 5,087,508 requires “recharging” of the phase change material at higher temperatures, while the device of EP 155,572 simply minimizes dew formation by minimizing radiative cooling of sign surfaces to the night sky. [0005] Surfactants have been used to obtain anti-fog properties on the surface of polymer films. The surfactants used are generally small molecules or oligomeric in nature, and present in relatively low concentrations. Examples of surfactants used for anti-fog applications in food packaging and greenhouse products include those described in U.S. Pat. Nos. 4,136,072; 4,609,688; 5,451,460; 5,766,772; 5,846,650; and 6,296,694 and EP 1,110,993. In general, the surfactant coatings are susceptible to water washing due to the low concentrations of surface active molecules. In addition, many of the anti-fog films are not dew resistant and exhibit only a modest decrease in surface water contact angles. [0006] Polymeric forms of hydrophilic surface agents have been disclosed as being useful for anti-fog films. U.S. Pat. No. 5,877,254 describes an anti-fog and scratch resistant polyurethane composition that include an isocyanate prepolymer, a hydrophilic polyol and an isocyanate-reactive surfactant. U.S. Pat. No. 4,080,476 describes an anti-fog coating for optical substrates wherein the coating comprises a polymerized monomer of, for example, 2-acrylamido-2-methyl propane sulfonic acid. International Publication WO 99/07789 describes the use of siloxane derivatives of polyetheralcohols as an anti-fog additive to a polyolefin prior to formation of a polyolefin film. Many of the prior art coatings do not provide a consistent long-lasting anti-fog coating. Rather, the anti-fog properties of these coatings fail after repeated washings with water. SUMMARY OF THE INVENTION [0007] A dew-resistant coating having particular utility for retroreflective articles is described. The dew-resistant coating is obtainable from a film-forming inorganic or inorganic/organic hybrid composition comprising silica wherein the silica particles comprise elongate particles having an aspect ratio of greater than 1. In one embodiment, the aspect ratio is greater than 2. [0008] In one embodiment the invention is directed to a dew-resistant coating comprising at least about 75% by weight of elongate silica particles having a width of about 9 to about 15 nanometers and a length of about 40 to about 300 nanometers. The coating may optionally include an organic binder. [0009] The dew resistant coatings of the present invention are useful for applications that include, but are not limited to, retroreflective and graphic signage, automotive interior glass, transportation industry paint, i.e., aviation, train and automobile paint, boat and ship bottoms, lubricous pipe coatings, freezer windows, clear plastic packaging, chromatography support, medical equipment surface treatment, bathroom mirrors, shower enclosures, and eyeglasses. [0010] One embodiment of the invention is directed to a retroreflective article comprising a substrate and a coating provided on at least a portion of a surface of the substrate that is exposed to moist air, the coated portion being retroreflective and the coating comprising elongate silica particles having an aspect ratio of greater than 1. Retroreflective articles to which the coating of the present invention may be applied include raised pavement markers having one or more retroreflective elements on the surface, traffic signs, license plates or self-adhesive stickers bearing visually observable information. In one embodiment, the coating on at least a portion of the retroreflective article comprises at least 75% by weight of elongate silica. [0011] Another embodiment of the invention is directed to a method of imparting dew-resistance to a retroreflective article, the method comprising: providing a retroreflective article having a surface; preparing a coating composition comprising elongate silica particles having a width of about 9 to about 15 nanometers and a length of about 40 to about 300 nanometers; applying the coating composition to at least a portion of the surface of the retroreflective article; and heating the coating composition to form a dew-resistant coating. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a schematic diagram of an apparatus used to measure dew resistance of an article having the dew resistant coating of the invention coated thereon. [0013] FIG. 2 is a gel permeation chromatography trace of various hydrolyzate oligomers of 3-glycidoxy propyltrimethoxy silane useful in the present invention. DETAILED DESCRIPTION OF THE INVENTION [0014] The dew-resistant coating of the present invention comprises elongate silica fine particles. The elongate silica particles are coated or grafted onto the surface of the substrate. The substrate is generally glass or a polymeric film. The dew-resistant coating can be transparent. When the substrate to which the dew-resistant coating is applied is a retroreflective film, a transparent dew-resistant coating is required. [0015] The silica useful in the present invention comprises elongate particle silica having an aspect ratio that is greater than 1.0. In one embodiment, the aspect ratio is greater than 2.0. As used herein, the term “aspect ratio” means the ratio of the length of the particle to the width. In one embodiment, the silica particles have an average width (diameter) of about 9 to about 15 nanometers and an average length of about 40 to about 300 nanometers. The elongate silica particles may be dispersed in an alcohol or in water. Commercially available elongate silica includes those available from Nissan Chemical Industries under the trade designations SNOWTEX UP and SNOWTEX OUP. The silica may also comprise string-of-pearls silica particles, which are chain silica particles available from Nisson Chemical under the trade designation SNOWTEX-PS. The solvent in which the particles are dispersed may be water, methanol, ethanol, isopropropanol, etc. [0016] In one embodiment, the coating composition comprises at least 75% by weight fine elongate silica particles. In other embodiments, the coating composition comprises at least 80%, or at least 90%, or at least 95% by weight fine elongate silica particles. In one embodiment, the coating composition comprises fine elongate silica particles and fine spherical particles having an average diameter of less than about 50 nanometers. The spherical particles may be provided in a colloidal dispersion of silica in a solvent that is compatible with the solvent of the elongate silica particles. For example, the spherical silica particles used may comprise Snowtex IPA-ST-MA from Nissan Chemical Industries, which is a silica sol of spherical silica particle having an average particle diameter of about 17-23 nanometers dispersed in isopropyl alcohol. A useful ratio of elongate silica particles to spherical silica particles is in the range of about 100:0 (i.e. 100% elongate silica) to about 70:30. In one embodiment, the ratio of elongate silica particles to spherical particles is in the range of about 100:0 to about 90:10. [0017] In one embodiment of the present invention, the coating composition comprises fine elongate silica particles and an organic binder. The organic binder may be present in an amount of about 0 by weight to about 10% by weight based on the total solids of the coating composition. In one embodiment, the organic binder may be present in an amount of about 4% to about 8%, or about 15% to about 25% by weight. The organic binder may comprise hydrolysis products and partial condensates of one or more silane compounds. Useful silane compounds include, but are not limited to epoxy-functional silanes. Examples of such epoxy-functional silanes are glycidoxy methyltrimethoxysilane, 3-glycidoxypropyltrihydroxysilane, 3-glycidoxypropyl-dimethylhydroxysilane, 3-glycidoxypropyltrimeth-oxysilane, 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl-dimethoxymethylsilane, 3-glycidoxypropyldimethylmethoxysilane, 3-glycidoxypropyltributoxysilane, 1,3-bis(glycidoxypropyl) tetramethyldisiloxane, 1,3-bis(glycidoxypropyl)tetramethoxydisiloxane, 1,3-bis(glycidoxypropyl)-1,3-dimethyl-1,3-dimethoxydisiloxane, 2,3-epoxypropyl-trimethoxysilane, 3,4-epoxybutyltrimethoxysilane, 6,7-epoxyheptyl-trimethoxysilane, 9,10-epoxydecyltrimethoxysilane, 1,3-bis(2,3-epoxypropyl) tetramethoxydisiloxane, 1,3-bis(6,7-epoxyheptyl)tetramethoxydisiloxane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like. [0018] Other useful silanes include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxy silane, octyltrimethoxysilane, decyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexylmethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, dimethyldimethoxysilane, 2-(3-cyclohexenyl)ethyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 2-chloroethyltrimethoxysilane, phenethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 3-isocyanopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 4-(2-aminoethylaminomethyl)phenethyltrimethoxysilane, chloromethyltriethoxysilane, 2-chloroethyltriethoxysilane, 3-chloropropyltriethoxysilane, phenyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, cyclohexyl-triethoxysilane, cyclohexylmethyltriethoxysilane, 3-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, [2-(3-cyclohexenyl)ethyltriethoxysilane, 3-cyanopropyltriethoxysilane, 3-methacrylamidopropyltriethoxysilane, 3-methoxypropyltrimethoxysilane, 3-ethoxypropyltrimethoxysilane, 3-propoxypropyltrimethoxysilane, 3-methoxyethyltrimethoxysilane, 3-ethoxyethyltrimethoxysilane, 3 propoxyethyltrimethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]heptamethyl trisiloxane, [methoxy(polyethyleneoxy)propyl]trimethoxysilane, [methoxy(polyethylene-oxy)ethyl]trimethoxysilane, [methoxy(polyethyleneoxy) propyl]triethoxysilane, [methoxy(polyethyleneoxy)ethyl]triethoxysilane, and the like. [0019] The organic binder may comprise a polymer that is hydrophilic. [0020] The dew resistant coating of the present invention may comprise a monolayer or a multilayer coating. In one embodiment, a tie layer is applied to the substrate to improve the adhesion of the outer silica containing coating. [0021] In one embodiment, the dew resistant coating comprises a first layer comprising fine spherical particles and an organic binder and a second, outer layer, comprising fine elongate silica. In another embodiment, the dew resistant coating comprises a first layer comprising fine elongate silica and an organic binder and a second, outer layer comprising a photocatalytic layer. [0022] The photocatalytic layer generally comprises TiO 2 particles. Photocatalytic compositions are disclosed in U.S. Pat. Nos. 6,228,480 and 6,407,033 to Nippon Soda Company, the disclosures of which are incorporated by reference herein. The second photocatalytic layer affords additional self-cleaning properties along with increased hydrophilicity upon UV irradiation. [0023] In one embodiment, photocatalytic nanoparticles are incorporated into a dew resistant coating composition that is applied to the substrate in a monolayer. The coating composition may comprise metal oxide particles in addition to the fine elongate silica particles. Such metal oxide particle may be used to obtain a desired refractive index or to obtain desired photoactivity. The elongate silica particles may be used in combination with other metals or metal oxides such as titania, zirconia, tin oxide, antimony oxide, iron oxide, lead oxide, needle TiO 2 , bayerite (Al(OH) 3 ) and/or bismuth oxide to incorporate other adjunct properties including color, conductivity (thermal and/or electrical), abrasion resistance, etc. [0024] In one embodiment, the coating composition comprises elongate silica particles, an organic binder and at least one surfactant. Useful surfactants include alkoxy siloxane-based surfactants, ethoxylated fatty alcohols such as lauryl alcohol, myristyl alcohol, palmityl alcohol and stearyl alcohol; polyethylene oxides; block copolymers of propylene oxide and ethylene oxide; alkyl polyethoxy ethanols; polyethylene lauryl ether; polyethylene stearate; ethoxylated nonylphenol; sorbitan ester of fatty acid; polyethylene sorbitan monostearate; polyglycerol esters of fatty acids such as lauryl acid, palmetic acid, stearic acid, oleic acid, linoleic acid and linolenic acid; polyoxyethylene distearate; polyoxyethylene sorbitan tristearate; ethylene glycol monostearate; sodium lauryl ether sulfate; ethoxylated amine; ethoxylated acetylenic alcohol; sodium sulfosuccinate; sodium dodecyl benzene sulfonate; fluorosurfactants; acetylenics and combinations of two or more thereof. The surfactant may be present in an amount of 0 to 10% by weight of the coating composition. [0025] When an organic binder is used, the coating composition may be cured via free radical, thermal, infrared, electron beam or ultraviolet radiation polymerization. For UV curable compositions, useful photoinitiators include sulfonium or iodonium salts such as SARCAT CD1010, SARCAT CD1011 and SARCAT CD1012 (available from Sartomer) and CYRACURE UVI 6974 available from Dow Chemical, IRGACURE 651, 184 and 1700 and DAROCURE 1173, available from CIBA-GEIGY; as well as GENOCURE LBP available from Rahn; and ESACURE KIP150 available from Sartomer; [4-[(2-hydroxytetradecyl)oxy]-phenyl]phenyliodonium hexafluoroantimonate, benzophenone, benzyldimethyl ketal, isopropyl-thioxanthone, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl) phosphineoxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl(2,4,6-trimethybenzoyl) phosphine oxides, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-(dimethyl-amino)-1-4-(4-morpholinyl)phenyl-1-butanone, alpha,alpha-dimethoxy-alpha-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-4-(methylthio) phenyl-2-(4-morpholinyl)-1-propanone, 2-hydroxy-1-4-(hydroxyethoxy)phenyl-2-methyl-1-propanone. Photosensitizers may be used in combination with the photoinitiator. Examples of photosensitizers include phthalimide derivatives, isopropylthioxanthone and carbazole compounds. [0026] The coating composition of the present invention can be applied to substrates by conventional methods, including flow coating, spray coating, curtain coating, dip coating, spin coating, roll coating, etc. to form a continuous surface film or as a pattern, as desired. In one embodiment, the coat weight of the applied coating is about 1 gsm or less. [0027] Any substrate compatible with the coating composition can be coated with the dew resistant coating. For example, plastic materials, wood, paper, metal, glass, ceramic, mineral based materials, leather and textiles may be coated with the dew resistant coating. Plastic substrates to which the dew resistant coating of the present invention may be applied include acrylic polymers, poly(ethyleneterephthalate), polycarbonates, polyamides, polyimides, copolymers of acrylonitrile-styrene, styrene-acrylonitrile-butadiene copolymers, polyvinyl chloride, butyrates, polyethylene and the like. Transparent polymeric and glass materials coated with these compositions are useful as flat or curved enclosures, such as windows, liquid crystal display screens, skylights and windshields, especially for transportation equipment. [0028] The dew resistant coating composition is particularly useful when applied to retroreflective sheeting. The transparent dew resistant coating enables the underling retroreflective sheeting to maintain its retroreflectivity and decreases or eliminates the likelihood of a “blackout” condition in moist environments. This may be achieved by using a dew resistant coated glass or a transparent plastic film that is adhered as an overlaminate to a retroreflective sign. Alternatively, this may be directly incorporated onto the top surface of a retroreflective article. Retroreflective substrates include raised pavement markers having one or more retroreflective elements on the surface, traffic signs, license plates or self-adhesive stickers bearing visually observable information. [0029] In one embodiment, the dew resistant coating is applied to at least a portion of the surface of a retroreflective sheet. The surface of the retroreflective sheet may comprise an acrylate polymer. In one embodiment, the surface of the retroreflective sheet to which the dew resistant coating is applied comprises a butyl acrylate/methylmethacrylate copolymer. [0030] In one embodiment, a removable protective layer is applied over the dew resistant coating to prevent damage to the dew resistant coating during storage, transport and application to the underlying substrate. The removable protective layer may comprise a polymeric film. In one embodiment, the protective layer comprises a water soluble or water miscible polymeric coating. Examples of such polymers include polyethylene oxide, polyvinyl alcohol, polyacrylic acid, alkyl metal silicate, polyvinyl pyrrolidone, (poly)hydroxyethyl methacrylate, and combinations thereof. TESTING METHODS [0000] Coat Thickness [0031] The coat thickness for film samples coated onto plastic substrates are determined via the cross-section method wherein a 2 micrometer thick slice is cut in the traverse direction through the dew-resistant coating and the film support using a microtome (RMC Rotary Microtome MT 990) equipped with a diamond knife (Delaware Diamond Knife). The microtome is set to operate at −10° C. and a cutting speed of about 10 mm/sec. An Olympus BX 60 optical microscope is used to observe the cross-section and to measure the coat thickness in micrometers via a digital camera (resolution 800×600) and the software package Image Pro-Plus at total magnification of 1000×. A second method used to determine coat weight is X-ray florescence spectrometry, which measures silicon for a silica-based coating, aluminum for an alumina-based coating, etc. A bench-top Oxford Lab-X 3000 XRF analyzer (Oxford Instruments) is used to measure dry coat weight of silica based coatings. Coated samples are die-cut into 3.5 cm diameter disks to measure the quantity of silicon present. [0000] Contact Angle: [0032] The contact angle between the surface of the coated substrate and a droplet of water is an indicator of the hydrophilicity of the coating. The lower the contact angle, the better the hydrophilic properties of the coating. The hydrophilicity of the film surface is measured using an FTA 200 dynamic contact angle goniometer available from First Ten Angstroms Corp. equipped with a Pelco video camera (PCHM 575-4). Contact angle measurements are taken using a 4 microliter water droplet in ambient air humidity at time intervals of 1 second, 5 seconds, and 10 seconds. [0000] Water Wash Resistance [0033] Coated samples are put in a bottle containing water and placed on a mechanical roller (available from Norton Chemical Process Products Division, Akron, Ohio) for 12 hours. Samples are then removed, re-washed under running water, dried and tested appropriately for anti-fog, dew resistance and/or contact angle (hydrophilicity). [0000] Anti-Fog: [0034] The anti-fog property of the coatings is screened by blowing a breath of air onto the surface of the test sample to determine if any haze develops. The sample may also be evaluated by putting the test surface face down, 1 inch away from the top of a boiling beaker of water. If no haze or dew is observed after 30 seconds, the sample is rated to have anti-fog properties. [0000] Dew Resistance: [0035] An outdoor dew resistance testing apparatus schematically represented in FIG. 1 is used to measure dew resistance outdoors. The dew-resistant coated retroreflective samples are laminated onto a metallic traffic sign. Dew is generated naturally by heat loss to the atmosphere provided by satisfactory meteorological conditions. The digital camera (IQEye3 camera server) is accompanied by an axial illumination system (12V white LED array) and a Rotronic 3 meteorological terminal that is linked to the camera server via a local serial bus. The outdoor dew tester transmits, at specified time intervals, images and meteorological data including dew point, relative humidity and air temperature to a data server via TCP communication protocol and the Internet. Reflectivity data for the dew resistant coated retroreflective samples is integrated from the bitmap histograms and compared to a sample of the uncoated retroreflective sample and plotted versus time. Each reflectivity data set includes measured meteorological parameters such as air temperature, air relative humidity and dew point. [0000] Percent Blackout [0036] For a given dew event, the percent blackout of a dew resistant coated sign is calculated as the number of hours the sign loses its reflective properties (loses more than 50% of its original reflectivity) divided by the number of hours the control (uncoated sign) loses its reflective properties, multiplied by 100. The apparatus used to measure the reflective properties of the sign is described above with reference to Outdoor Dew Resistance testing. [0000] Xenon Weathering: [0037] Xenon weathering testing is carried out with an Atlas Ci5000 Xenon Arc Weather-Ometer (Atlas Electric Devices Company, Chicago, Ill.) according to ASTM G155-1 with two light cycle segments. For both light cycles, irradiance is the same: 0.35 watts/M 2 at 340 nm, with black panel temperature set at 63° C., chamber temperature at 40° C., and relative humidity at 50%. The first light cycle is 102 minutes, with no water spray and the second light cycle is 18 minutes with water spray on the sample surface. [0000] QUV Weathering: [0038] A QUV Accelerated Weathering Tester (Q-Panel Lab Products, Cleveland, Ohio) is used to carry out the testing according to ASTM G-154 procedures. A UVA-340 lamp with typical irradiance of 0.77 watts/m 2 or a UVB-313 lamp with typical irradiance of 0.63 watts/m 2 is applied in the test. The UVA-340 lamp has similar spectral power distribution as sunlight. The typical cycles include an 8 hour UV light cycle at 60° C. black panel temperature and a 4 hour condensation cycle at 50° C. black panel temperature. [0000] Retroreflectivity: [0039] A hand-held RetroSign retroreflectometer type 4500 (Danish Electronics, Light & Acoustics of Denmark) is used to measure retroreflectivity according to ASTM D4956-01 Standard Specification for Retroreflective Sheeting for Traffic Control. The retroreflectometer measures with a fixed entrance angle at −4 and observation angle of 0.2°. [0000] Mandrel Test: [0040] The Mandrel test accelerates cracking of the coating, which contributes to increased haze, and therefore, decreases retroreflectivity. Retroreflective sheeting samples with adhesive backing are cut in 2 cm (cross direction)×4 cm (machine direction) strips and applied to a glass rod having a 1 inch diameter. Hand applied pressure is used to wrap the sample around the rod. Tape may be used to further secure the sample strip ends to the glass rod. The rod is then placed in an apparatus for temperature cycling and examined under optical microscope for extent of cracking. A scale of 1 to 5 is used to rate the extent of cracking observed after thermal cycling. The temperature cycling is as follows: Initial Values of Each Step Graded Target Time Step Tempera- Humidi- Tempera- Humidi- Setting No. ture (° C.) ty (%) ture (° C.) ty (%) (hours) 1 Room Room 20 20 1 2 20 20 2 3 20 20 60 20 1 4 60 20 2 5 60 20 60 80 1 6 60 80 2 7 60 80 −10 0 1 8 −10 0 2 [0041] In order to further illustrate the present invention, the following examples are given. However, it is to be understood that the examples are for illustrative purposes only and are not to be construed as limiting the scope of the present invention. EXAMPLES Examples 1-14 [0042] A solution of colloidal elongate silica in isopropyl alcohol (Snowtex IPA-ST-UP from Nissan Chemical Industries, 15% by wt. SiO 2 in isopropanol) is coated onto retroreflective sheeting (Avery Dennison T-7500 Prismatic Grade Reflective Sheeting) or a polyethylene terephthalate (PET) substrate at various coat weights (wet) and at various percent solids of the elongate silica is isopropyl alcohol. The solution is coated using a Sheen automatic coater with drawbars of 1 and 0.5 gauges. The coated substrates are placed in an air convection oven and heated at 75° C. for 15 minutes. Table 1 below shows the measured contact angle and retroreflectivity of the coated substrates. [0043] Also presented in Table 1 is Comparative Example 14 in which elongate silica in MEK solvent is used to coat a retroreflective sheet. The resulting coating has a high contact angle. While not wishing to be bound by theory, it is believed that the high contact angle is the result of the hydrophobization treatment of the silica particles surface carried out to enhance the solution stability of the MEK solvent suspension. TABLE 1 Initial Contact Reflec- % Coat Angle tivity Exam- Sol- Sub- Thickness (5 (cd/lux/ ple Silica ids strate (wet) mil sec.) m 2 ) 1 IPA-ST-UP 15 T7500 1 10.4 1234 2 IPA-ST-UP 10 T7500 1 8.1 1280 3 IPA-ST-UP 5 T7500 1 10.4 1229 4 IPA-ST-UP 1 T7500 1 30.5 1277 5 IPA-ST-UP 0.1 T7500 1 51.2 1172 6 IPA-ST-UP 15 PET 1 10.4 — 7 IPA-ST-UP 15 PET 0.5 7.7 — 8 IPA-ST-UP 10 PET 1 4.4 — 9 IPA-ST-UP 10 PET 0.5 4.7 — 10 IPA-ST-UP 5 PET 1 10.4 — 11 IPA-ST-UP 5 PET 0.5 5.4 — 12 IPA-ST-UP 1 PET 1 11.0 — 13 IPA-ST-UP 1 PET 0.5 21.1 — Comp. MEK-ST-UP 15 T7500 1.0 39.8 N/A 14 Example 15-18 [0044] Colloidal elongate silica particles in isopropyl alcohol (Snowtex IPA-ST-UP) is mixed with spherical silica particles in isopropyl alcohol (Snowtex IPA-ST-MS) in the weight ratios shown in Table 2. The Snowtex IPA-ST-MS silica sol contains 30% by weight silica having an average particle width of 17-23 nanometers. The coatings are prepared substantially in accordance with the procedure of Ex. 1-14 above. The contact angle (10 sec) measured for each of the coated films is presented in Table 2 below. TABLE 2 Ratio of elongate/spherical Coat Weight Contact Angle Example (wt. % solids) (g/m 2 ) 10 sec (deg.) 15 90/10 3.1 4.9 16 100/0  2.3 9.0 17 70/30 3.5 11 18 50/50 3.9 16 [0045] The results indicate that a minor amount of spherical silica added to the elongate particle silica improves the contact angle of the resulting coating. For comparative purposes, a coating of 100% spherical silica (Snowtex IPA-ST-MS) is prepared and coated onto a retroreflective sheet. However, the coating does not adhere to the retroreflective sheet so that the contact angle cannot be measured. Example 19 [0046] A hydrolyzate oligomer of 3-glycidoxypropyl trimethoxysilane (GPTMS) is prepared by mixing 5 g of GPTMS with 1.14 g of aqueous HCL (0.12M), sirring the solution for 1 hour, 24 hours and 1 week to give hydrolysis and condensation product of GPTMS. The coating composition is prepared by mixing the hydrolyzed GPTMS (0.66 g) with 5 g IPA-ST-UP and 2.09 g of a solution of 3,6-dioxa-1,8-octanedithiol (DOT) in isopropyl alcohol. The coating composition is coated onto a retroreflective sheet (T-7500 from Avery Dennison) using a 0.5 mil gauge draw bar and an automatic coater. The coated film is dried at room temperature, and then cured in a convection oven at 75° C. for 1 hour. Table 3 below shows the contact angle and retroreflectivity of the coated substrates with and without Xenon Weathering (383 hours). [0047] FIG. 2 is a gel permeation chromatography trace that plots intensity as a function of elution time. The numbers noted on the plots reflect the molecular weight at the particular elution time. The intensity indicates the concentration and the time indicates the molecular weight. FIG. 2 illustrates the degree of hydrolysis of the GPTMS at 1 hour, 24 hours and 1 week. TABLE 3 Time for Xenon Avg. Retro- Water Contact Angle Hydrolysis Hours reflectivity 0 sec 5 sec 10 sec 1 hour 0 1329 28 26 25 383 1043 12 7 6 24 hours 0 1371 25 24 22 383 1216 9 6 5 1 week 0 1362 23 21 20 383 838 11 8 6 Examples 20-31 [0048] In Example 20, a hydrolyzate oligomer of 3-glycidoxypropyl trimethoxysilane (GPTMS) is prepared by mixing 5 g of GPTMS with 1.14 g of aqueous HCL (0.12M), stirring the solution for 1 hour to give hydrolysis and condensation product of GPTMS. The coating composition is prepared by mixing the hydrolyzed GPTMS (0.75 g) with 5 g IPA-ST-UP and 0.49 g of a 10% by weight solution of Tinuvin 1130 in isopropyl alcohol. Before coating the retroreflective sheet, 2.09 g of a solution of 3,6-dioxa-1,8-octanedithiol (DOT) in isopropyl alcohol is added drop-wise to the composition mixture. The mixture is stirred and degassed. The coating composition is coated onto a retroreflective sheet (T-7500 from Avery Dennison) using a 0.5 mil gauge draw bar and an automatic coater. The coated film is dried at room temperature, and then cured in a convection oven at 75° C. for 1 hour. [0049] Examples 21-31 are prepared substantially in accordance with the procedure of Example 20, with the exception that the weight ratio of hydrolyzed GPTMS is varied as is the presence of UV absorber. Additionally, spherical silica is used in place of the elongate silica in Examples 26 to 31. Table 4 below shows the contact angle and retroreflectivity in the cross direction and in the machine direction of the coated substrates after Xenon Weathering (935 hours). TABLE 4 UV Reflectivity % SiO 2 :Binder Absorber Contact Angle (cd/lux/m 2 ) Example Silica Solids (w/w solids) (3% solids) (degree/5 sec) (CD/MD) 20 IPA-ST-UP 15 1:1 yes — — 21 IPA-ST-UP 15 3:1 yes 10  832/728 22 IPA-ST-UP 15 9:1 yes 7.9  1238/1047 23 IPA-ST-UP 15 1:1 no 15.5  1368/1112 24 IPA-ST-UP 15 3:1 no 9.7 1218/989 25 IPA-ST-MS 15 9:1 no 8.5 1168/917 26 IPA-ST-MS 15 1:1 yes 17  1500/1237 27 IPA-ST-MS 15 3:1 yes 12 1343/960 28 IPA-ST-MS 15 9:1 yes 6.4 1300/986 29 IPA-ST-MS 15 1:1 no 16.6 1042/927 30 IPA-ST-MS 15 3:1 no 9.2  1362/1167 31 IPA-ST-MS 15 9:1 no 9.1  1521/1216 Examples 32-37 [0050] Examples 32-37 are prepared substantially in accordance with the procedure of Example 20, with the exception that the weight ratio of hydrolyzed GPTMS is varied as is the presence of UV absorber. Examples 36 and 37 use elongate silica in MEK in place of the elongate silica in isopropyl alcohol. Table 5 below shows the contact angle and retroreflectivity of the coated substrates. Examples 38-39 [0051] For Example 38, a hydroxyethyl methacrylate (HEMA)/methyl methacrylate (MMA) copolymer solution is prepared by degassing, followed by heating at 60° C. for 24 hours a mixture of 2.3 g HEMA, 17.70 g MMA (10 mol MMA to 1 mol HEMA) and 0.05 g Vazo 64 in 80.0 g dry MEK. The coating composition is prepared by mixing 2.00 g of the polymer solution and 0.018 g aluminum acetylacetonate (AAA, 3% by weight with respect to solids) and 2.0 g Snowtex MEK-ST-UP. The coating composition is coated on retroreflective sheeting (Avery Dennison T-7500) using a 0.5 mil gauge draw bar and an automatic coater. The coated film is dried at room temperature and then cured in a convection oven at 75° C. for 1 hour. [0052] Example 39 is prepared substantially in accordance with the procedure of Example 38, with the exception that weight ratio of silica to organic binder is varied. [0053] Table 5 below shows the contact angle and retroreflection of the resulting coated substrates. Also shown is the contact angle and retroreflection of the coated substrates of Examples 21-35 after they have been subjected to corona treatment. TABLE 5 Contact Angle Reflectivity UV (degree/5 sec) (cd/lux/m 2 ) % SiO 2 :Binder Absorber Contact Angle Reflectivity with corona with corona Example Silica Solids (w/w) (3% solids) (degree/5 sec) (cd/lux/m 2 ) treatment treatment 32 IPA-ST-UP 10 1:1 yes 14.7 1285/1296 13.9 1260/1247 33 IPA-ST-UP 10 3:1 yes 27.7 1276/1319 9.1 1211/1293 34 IPA-ST-UP 10 9:1 yes 18.8 1397/1364 6.9 1255/1293 35 IPA-ST-UP 10 1:0 yes 14.9 1314/1364 6.2 1273/1307 36 MEK-ST-UP 15 1:1 no 56.6 1129/1227 — — 37 MEK-ST-UP 15 9:1 no 65.9 1122/1200 — — 38 MEK-ST-UP 15 1:1 no 62.7 1194/1090 — — 39 MEK-ST-UP 15 9:1 no 25.4 1168/1124 — — Examples 40-43a [0054] Examples 4043a are directed to dual layer dew resistant coatings. Specifically, a first primer layer is formed on the retroreflective sheet, followed by a second top layer formed over the primer layer. [0055] Preparation of Primer A: [0056] Primer A is prepared by mixing together in a 1:1 ratio by weight 3-glycidoxypropyl trimethoxysilane (GPTMS) and Snowtex IPA-ST-MS spherical particles. [0057] Preparation of Primer B: [0058] Primer B is prepared by mixing together in a 4:1 ratio by weight a methyl methacrylate/methoxypropyltrimethoxysilane copolymer (7.65:1 MMA:MOPTS) with hydrolyzed tetraethoxysilane. [0059] Preparation of Primer C: [0060] Primer C is prepared by mixing together in a 1:1 ratio by weight 3-glycidoxypropyl trimethoxysilane (GPTMS) and Snowtex IPA-ST-UP elongate particles. [0061] Top Layer I: [0062] The composition of Top Layer I is Snowtex IPA-ST-UP elongate particles. [0063] Top Layer II: [0064] The composition of Top Layer II is a photocatalyst solution of TiO 2 with a solids content of 9.4% (Bistrator NRC-300C from Nippon Soda Co., Ltd.). Example 40 Control [0065] Top Layer I is coated onto a retroreflective sheet (Avery T-7500) at a coat thickness of 1 mil (wet) and heated in a convection oven at 70° C. for 30 minutes. The contact angle and retroreflectivity of the coated sheet is shown below in Table 6 below. Example 41 [0066] Primer A is coated onto a retroreflective sheet (Avery T-7500) at a coat thickness of 1 mil (wet) and heated in a convention oven at 55° C. for 15 minutes. Top Layer I is then applied over Primer Layer A at a coat thickness of 1 mil (wet) and heated for at 70° C. for 1 hour. The contact angle and retroreflectivity of the coated sheet is shown below in Table 6 below. Example 42 [0067] Primer B is coated onto a retroreflective sheet (Avery T-7500) at a coat thickness of 1 mil (wet) and heated in a convention oven at 70° C. for 1 hour. Top Layer I is then applied over Primer Layer B at a coat thickness of 1 mil (wet) and heated for at 70° C. for 1 hour. The contact angle and retroreflectivity of the coated sheet is shown below in Table 6 below. Example 43 [0068] Primer C is coated onto a retroreflective sheet (Avery T-7500) at a coat thickness of 1 mil (wet) and heated in a convention oven at 55° C. for 15 minutes. Top Layer II is then applied over Primer Layer C at a coat thickness of 1 mil (wet) and heated for at 70° C. for 1 hour. The contact angle and retroreflectivity of the coated sheet is shown below in Table 6 below. Example 43a [0069] Example 43a is substantially the same as Example 43, with the exception that prior to measuring the contact angle and retroreflectivity, the coated substrate is placed in a Xenon Weatherometer overnight for UV activation of the Top Layer II. Subsequent to UV activation of the photocatalytic layer, the contact angle of the coated substrate decreases relative to that Example 43, the un-activated coated substrate. TABLE 6 Exam- Pri- Top Contact Angle degree (std. dev.) Retro- ple mer Layer 0 sec 5 sec 10 sec reflectivity 40 — I 6.5 (0.6) 5.1 (0.5) 4.1 (0.2) 1347 41 A I 21.5 (1.6) 19.2 (3.1) 18.3 (1.0) 1309 42 B I 12.1 (0.2) 5.2 (0.2) 4.0 (0.3) 1288 43 C II 46.4 (4.3) 45.5 (2.4) 45.4 (2.3) 1069 43a C II 5.6 (0.6) 4.5 (0.8) 3.3 (0.5) 1248 Examples 44-49 [0070] A coating of 100% elongate silica (Snowtex IPA-ST-UP) is applied to retroreflective sheeting at various coat weights. The coated sheeting is subjected to the Mandrel Test described above. Table 7 shows the results of the testing. TABLE 7 Example Coat Weight (gsm) Mandrel Rating* 44 0.57 0 45 0.81 1 46 1.12 3 47 1.13 2 48 1.27 3 49 2.85 5 *A rating of 0 indicates no cracks, 1 indicates some tiny cracks, 2 indicates thin and light cracks, 3 indicates moderate cracks, 4 indicates dense and thin cracks, 5 indicates dense and thick cracks. Example 50 [0071] A hydrolyzate oligomer of 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane (CHTMS) is prepared by mixing 3 gms of CHTMS with 3.67 gms of isopropanol and 0.66 gms of aqueous HCl (0.12M), stirring the solution for 1 hour to obtain the hydrolysis and condensation product of CHTMS. The coating composition is prepared by mixing the hydrolyzed CHTMS (0.24 gms) with 6 gms of elongate silica particles in isopropyl alcohol (Snowtex IPA-ST-UP) and 0.03 gms [4-[(2-hydroxytetradecyl)oxy]-phenyl]phenyliodonium hexafluoroantimonate (a cationic UV initiator). The total solids content is decreased to a final 10% by weight by the addition of 3.76 gms of coating solvent isopropanol. [0072] The coating composition is coated onto a retroreflective sheet (T-7500 from Avery Dennison Corporation) using a 0.5 mil gauge draw bar and an automatic coater. The coated film is dried at 70° C. for 2 minutes, and then UV cured using a Fusion UV System with an H-bulb at 35 fpm for 1 pass. The film is then corona treated prior to testing. Examples 51-54 [0073] Dew resistant coatings are prepared substantially in accordance with the procedure of Example 50, with the exception that the amount of hydrolyzed CHTMS used is varied as shown in Table 8. The weight percent CHTMS shown is based on the total solids of the coating composition. The refractive index, obtained by the ellipsometry method for the coatings and the retroreflectivity of retroreflective sheets coated with the dew-resistant coatings as compared to the uncoated retroreflective sheets (two samples of each coating) are shown in Table 8. The retroreflectivity was measured in the machine direction (MD) and the cross direction (CD) for each sample. TABLE 8 % wt. Refractive Uncoated After Coating Example CHTPMS Index MD CD MD CD 50 20 1.29 1177 1152 1218 1210 1137 1153 1208 1216 51 5 1.35 1120 1115 1244 1255 1101 1140 1199 1237 52 7 1.38 1054 1119 1302 1299 1103 1121 1232 1257 53 50 1.49 1134 1159 1207 1254 1139 1156 1299 1285 54 10 — — — Example 55 [0074] A dew resistant coating is prepare substantially in accordance with the procedure of Example 50, with the exception that the hydrolysis and condensation reactions of CHTMS are carried out by reacting the monomer CHTMS in an aqueous solution of elongate silica particles followed by vacuum distillation to remove the water and subsequent dilution with isopropanol. Example 56 [0075] A hydrolyzate oligomer of 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane (CHTMS) is prepared by mixing 3 gms of CHTMS with 3.67 gms of isopropanol and 0.66 gms of aqueous HCl (0.12M), stirring the solution for 1 hour to obtain the hydrolysis and condensation product of CHTMS. The coating composition is prepared by mixing the hydrolyzed CHTMS (0.24 gms) with 6 gms of elongate silica particles in isopropyl alcohol (Snowtex IPA-ST-UP) and 0.03 gms 3,6-dioxa-1,8-octanedithiol (DOT). The total solids content is decreased to a final 10% by weight by the addition of 3.76 gms of coating solvent isopropanol. The coating composition is coated onto a retroreflective sheet (T-7500 from Avery Dennison Corporation) using a 0.5 mil gauge draw bar and an automatic coater. The coated film is dried at 70° C. for 2 minutes, and then cured in a convection oven at 75° C. for 1 hour. [0076] Table 9 below shows the percent blackout for examples of the dew resistant coating that were coated onto retroreflective sheeting (Avery Dennison T-7500). TABLE 9 Percent Blackout Days Uncoated Example 1 Example 51 Example 52 0 100% 40% 86% 86% 4 100% 67% — — 6 100% 38% — — 13 100% 45% — — 22 100% 50% — — 25 100% — 46% 54% 27 100% — 33% 33% 29 100% — 52% 52% 34 100% —  9%  9% 36 100% — 15% 15% 48 100% 31% — — 50 100% 27% — — 52 100% 67% — — 57 100% 25% — — 59 100% 27% — — [0077] The dew resistant coatings of Examples 1, 50, 52 and 54 were evaluated for durability. Specifically, the retroreflectivity and contact angle for these coatings on a retroreflective sheet (T-7500 from Avery Dennison Corporation) prior to exposure and after 4502 hours of Xenon weathering are Shown in Table 10 below. TABLE 10 Retroreflectivity Contact Angle Before 4502 hrs Before 4502 hrs Example exposure Xe exposure Xe 1 1310 1237 4.7 6.0 50 1010 1124 2.8 8.8 52 1192 1119 3.5 11.6 54 1112 1160 4.5 10.1 [0078] The durability of dew resistant coatings of Examples 50 and 51 were evaluated on various retroreflective substrates as shown in Table 11 below. Specifically, the contact angle was measured for samples coated on Retroreflective sheeting (T-7500 from Avery Dennison Corporation) before and After 2120 hours of Xenon weathering. TABLE 11 Contact Angle Contact Angle Before Exposure After 2120 hours Example Substrate [deg. (std. dev.)] [deg. (std. dev.)] 50 white 25.3 (1.7) 7.2 (1.0) 50 blue 26.7 (1.2) 7.7 (2.0) 50 green 26.4 (0.5) 5.9 (1.0) 51 white 25.0 (0.8) 9.5 (3.0) 51 blue 25.7 (0.9) 10.7 (1.0) 51 green 25.8 (0.2) 11.9 (1.0) [0079] Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. In particular regard to the various functions performed by the above described elements (components, assemblies, compositions, etc.), the terms used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

The present invention relates to dew resistant coatings and articles having the dew resistant coating adhered thereto. The dew resistant coatings comprise elongate silica particles. These coating are useful on articles or surfaces used in outdoor applications and articles and surfaces used in moist indoor environments.

FIELD OF THE INVENTION The present invention generally relates to a dynamic balancing machine, and, more particularly, to an automatic digital dynamic balancing machine wherein the amount and angular location of unbalance in a rotating part is calculated off line and the part is stopped with the unbalance in a predetermined position without using a reference marking on the rotating part. BACKGROUND OF THE INVENTION In the dynamic balancing of a rotating part such as an electric motor armature, the part is mounted on its axis between bearings, rotated, and the unbalance is sensed by vibration or force sensors at the bearing locations. Several methods and devices have been developed to indicate the location of the unbalance on a rotated part. Two early types of machines widely used in industry use stroboscopic and photocell techniques to locate the unbalance. These both had the disadvantage of requiring physical markings on the part being rotated. These machines also required visual estimates of the unbalance location and were therefore subject to operator error. The most advanced machine of this type is disclosed in U.S. Pat. No. 4,419,894 to Matumoto, wherein an unmarked workpiece is rotated, the unbalance measured and located, and the workpiece stopped with the unbalance position in a predetermined orientation for subsequent marking and material mass addition or removal. This machine utilizes vibration sensors to generate an analog unbalance signal which is sinusoidal. An unbalance phase pulse is then electronically generated once per cycle at the positive going zerocrossing of the unbalance signal. The workpiece is driven by a stepper motor. Each drive pulse supplied to the stepper motor causes the workpiece to rotate an unknown but fixed angle. A counter, preset with a number representing an integral number of stepper motor drive pulses, is counted back upon each stepper motor drive pulse, starting with the receipt of an unbalance phase pulse and the rotated workpiece is stopped when the counter reaches zero. It is a real time system in that pulses coming from the unbalance sensor are used to initiate the countdown. There are several limitations and drawbacks associated with this type of machine. First, considerable time is required to initially set up the machine to maximize plane separation, select optimum counter settings, and set acceleration and deceleration rates to minimize belt slippage. These adjustments must be made for each different workpiece type measured. Settings are determined by trial and error methods which are awkward and time consuming. Second, the Matumoto method does not verify the accuracy of the determination of the rotational speed and therefore introduces error due to inherent drive belt slippage between the stepper motor drive and the driven part. Third, minor differences in armature diameters may introduce errors in unbalance positioning because the Matumoto machine does not measure and utilize the actual rotational frequency of the workpiece. Finally, because the Matumoto method involves time consuming setup steps and inherent errors for each workpiece, it entails significant restrictions in efficiency for production line processing. SUMMARY OF THE INVENTION The present invention provides an automatic balancing machine and method that overcomes the above identified drawbacks and disadvantages. It is an object of this invention to provide a dynamic balancing machine and a digital method for automatically determining the amount and angular location of unbalance in a rotating part and stopping the part with the unbalance accurately positioned in a predetermined orientation for marking and correction. It is a further object of this invention to provide an automatic balancing method wherein the angular velocity of the rotating part is accurately measured and a correction made to the assumed angular velocity to accurately calculate the time to decelerate and position the unbalance in a predetermined orientation. It is a further object of this invention to provide an automatic digital balancing machine that digitally calculates the unbalance phase angle off line by use of a microprocessor and displays the unbalance of each correction plane visually using conventional video technology. Accordingly the present invention provides a machine and method for automatically determining the location and amount of unbalance of a rotated part accurately and efficiently. The invention involves a unique combination of steps to determine the unbalance location and magnitude. The method comprises the following operative steps: (a) rotating a part to be balanced between two axially opposed bearings; (b) generating an electrical signal proportional to the rotary unbalanced at one of the bearings; (c) calculating the actual angular velocity from the unbalanced signal and a predetermined assumed angular velocity; (d) calculating the time at which to begin the acceleration of the part at a predetermined deceleration rate in order to stop the part with the unbalanced location in a predetermined position; and (e) decelerating the part at the predetermined rate at the proper time. An illustrative and specific embodiment of the method invention comprises the following steps: (a) rotating the part between stationary bearings, (b) generating an analog electrical unbalance signal proportional to the forces generated by the rotating part at the bearing locations, (c) generating time interval signals synchronous with the rotation, (d) converting the analog unbalance signal to a digital signal, (e) measuring and storing a first digital signal sample during a first set of predetermined repetitive time intervals, (f) measuring and storing a second digital sample during a second like set of time intervals contiguous with the first, (g) calculating the average demodulated phase angles for the first and second sets of samples according to the following equations: ##EQU1## where A x and A y are the demodulated coordinate components of the average unbalance signal from a set of samples "A" N=number of discrete sample elements per revolution M=number of revolutions per sample set S=sample element of the electrical unbalance signal sample (h) calculating the actual angular velocity R according to the following equation: ##EQU2## where M=the number of revolutions between the center of a first sample set to the center of a second sample set at the assumed angular velocity B=the unbalance angle of the second sample set in radians A=the unbalance angle of the first sample set in radians T=the total length of time between the center of the first sample set to the center of the second sample set (i) calculating the number of time intervals corresponding to the unbalance phase angle at the actual angular velocity, (j) calculating the deceleration time period required to bring the part to rest in a predetermined integral number of revolutions, (k) establishing an initial reference point in time corresponding to some point during the measuring intervals, (l) triggering the deceleration of the rotating part when the elapsed time intervals from the initial reference point equals the sum of the calculated time intervals corresponding to the unbalance phase angle plus a predetermined calculation time interval from the initial point. The preferred embodiment of balancing machine includes a frame, axially opposed bearing for rotatably supporting the part to be balanced, at least one force detector for detecting the forces normal to the axis of part rotation, circuit for producing an electrical unbalance signal, clock for generating an indication of repetitive time intervals, sampling device for measuring sets of discrete sequential sample elements, memory for storing the sample sets, device connected to the drive motor for controlling the drive motor synchronous with the sampling device, a microprocessor device for calculating the demodulated average unbalance components of each of two contiguous sample sets, calculating the difference value between the two sets of average unbalance, calculating the actual angular velocity from the difference value, controlling the deceleration of the drive motor at a constant rate unit the part is stationary, and calculating the time to decelerate the part and stop the part with the unbalance in a predetermined position. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a two plane hard bearing balancer; FIG. 2 is a sectional view of the balancer illustrating the different drive belt arrangements between the stepper motor and the driven part; FIG. 3 is a graph of angular velocity versus time for a rotating workpiece illustrating the major events during a measuring cycle; FIG. 4 is a block diagram of a two plane hard bearing balancer utilizing an encoder to generate timing intervals; and FIG. 5 is a partial front view of the two plane hard bearing balancer shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and more particularly to FIG. 1 there is shown an elementary block diagram of the automatic digital balancing machine and microprocessor components. The workpiece part 180 to be balanced is mounted between hard bearings 190 and 200. A DC stepper motor 160 is connected to the part via belt 170. There are several belt orientations that may be used. Referring now to FIG. 2, there is shown three alternate belt arrangements. The DC stepper motor sheave 330 is connected around idler pulleys 340 and 350 in two orientations of the driven part 180. The belt 170 routed underneath part 180 and over idler pulleys 340 and 350 is a preferred arrangement for small, light parts where production run speed is more important than minimizing signal noise. Belt 171 routed over part 180 and idlers 340 and 350 is an alternate but not preferred arrangement. The belt 172 routed between the stepper motor and the part directly is used where minimizing noise is critical. FIG. 3 illustrates curve 1 of a typical measurement sequence. Curve 1 shows an increasing part angular velocity until full operating speed is reached at which time the speed becomes and remains constant until deceleration begins. During region 80 the part is accelerated at a constant value from rest at point 10 to the operating speed at point 20. At point 20 the acceleration becomes zero and the part rotates at a constant angular velocity during regions 90, 100, 110, and 120. At point 60 deceleration begins at a constant rate in region 130 until the part is stopped at point 70. Acceleration and deceleration in regions 80 and 130 need not be the same rates. The critical rate is in region 130 where deceleration must be slow enough that no slippage occurs between the drive stepper motor, the part, and the drive belt due to inertial forces and must occur in an integral number of revolutions. A first sample set begins at point 20 and is completed at point 30 which is also the beginning of the second sample set. The second sample set ends at point 40. Each sample set 90 and 100 optimally correspond to 16 revolutions of 32 samples per revolution for a total of 512 samples in each set of data. Points 140 and 150 represent the center of the first and second sampling intervals respectively. Returning now to FIG. 1, the DC stepper motor 160 and bearings 190 and 200 are rigidly mounted to the machine frame 5. Piezoelectric transducers 202 and 203 are utilized to generate electrical signals proportional to the forces applied to them. When the part 180 is rotated, these forces are normal to the axis of rotation and represent the unbalance present in the rotating part. The signal generated by piezoelectric transducers 202 and 203 also contain unwanted signals. The unwanted signals at or above the sampling rate are eliminated by antialiasing filters 210 and 220. These unbalance signals (U L , U R ) are then sent to multiplexer 230 where a choice of either S L or S R is made for further processing. Plane separation is required because the signal from the transducer 202 will have part of its magnitude due to the influence of the forces at transducer 203 and vice versa. During calibration the vector constants (K 1 , K 2 , K 3 , K 4 ) are determined in the following set of equations: U.sub.L =K.sub.1 * S.sub.L +K.sub.2 * S.sub.R U.sub.R =K.sub.3 * S.sub.L +K.sub.4 * S.sub.R where S L is the separate left channel signal, S R is the separate right channel signal, U L is the composite left channel signal, and U R is the composite right channel signal. By utilizing known unbalance masses, positions, and the frequency of rotation, constants K 1 , K 2 , K 3 , and K 4 can be determined and entered into random access memory 300 automatically by the microprocessor 270. Microprocessor 270 is then enabled to perform the required plane separation. Referring now to FIG. 5, which is a partial frontview of the rated part mounting configuration, the following physical parameters are required to be input and stored in the microprocessor 270 RAM 300 via keyboard 370 (FIG. 1) prior to measuring or calibration of any rotated part: (a) Left plane 531 location 530, measured from the bearing 190 along the rotational axis; (b) Left correction radius 560, measured from the rotational axis radially to the surface of the part at the location of the left plane 531; (c) Right plane 532 location 540, measured from the bearing 190 along the rotational axis; and (d) Right correction radius 570, measured from the rotational axis radially to the surface of the part in the location of the right plane 532. Note that FIG. 5 illustrates the length 550 of rotating part 180 from bearing 190 to bearing 200. Referring back to FIG. 1, in order to determine the constants K 1 , K 2 , K 3 , and K 4 for a class of rotated parts, a three spin calibration procedure is followed to generate three sets of known unbalance signals which the microprocessor 270 then uses to mathematically determine the constant values. This procedure requires the use of a photoreflector sensor 310 and a reflective target 320 (see FIG. 1) temporarily affixed to a rotating part 180 which is an example of the desired type of rotating parts. Referring back to FIG. 5, the reflective target is shown behind the rotated part 180. In FIG. 5 is also shown a calibration weight 510 placed at the left plane 531. This is the position of the weight during the first calibration spin. The part is then stopped and the calibration weight moved to the right plane 532 (shown in phantom at 520) for the second spin. The third spin is done with the calibration weight removed. Prior to the first spin, however, the following information must be input to the microprocessor 270 via the keyboard 370: (a) Calibration weight; (b) Radius 560 at left plane 531 measured from the rotational axis to the surface of the rotated part 180; (c) Angle between target 320 and left calibration weight location 510; (d) Radius 570 at right plane 532 measured from the rotational axis to the surface of the rotated part 180; (e) Angle between target 320 and right calibration weight location 520; and (f) Photo pickup (310) angle measured from the back of the base unit (5) counterclockwise when viewed from the right side. The three spins provide known values of unbalance from which the microprocessor circuitry determines the values of K 1 , K 2 , K 3 , and K 4 used to correct the actual unbalance signals at the chosen left and right unbalance planes, U L and U R respectively to give the true unbalance signals S L and S R . Referring again to FIG. 1, during a spin of the part 180, corrected signals S R or S L enter the sample hold circuit 240 from the multiplexer 230. The microprocessor 270 also feeds timing pulses to the sample hold circuit to establish the sample increments. Once the rotating part 180 reaches operating speed the two set sampling begins. Each sample element for each sample increment is then converted to a digital equivalent signal by the analog/digital converter 250. Each digital signal element is then stored by the microprocessor in random access memory 300 to await further processing. Each sample set of 512 elements is stored in random access memory 300 in 512 separate locations corresponding to the signal's time interval. The central processing unit 280 marks the time corresponding to an arbitrary point such as the last sample increment in the sample time sequence as an initial point. The clock 305, through the central processing unit 280, also provides the timing pulses to the DC stepper motor such that the position of the DC stepper 160 motor relative to the initial point is currently known by the central processing unit 280. When two contiguous sets of samples S A and S B have been stored by the microprocessor 270, the phase angle relative to the arbitrary reference can be determined. The central processing unit 270 accesses read only memory 290 wherein a 512 element table of sine and cosine functions are stored. These tables are then employed with the stored sample data to calculate the average demodulated components of the phase angle with respect to a predetermined desired position. The sine and cosine table values are employed with the stored sample elements by microprocessor 270 to generate the demodulated phase angle coordinates A x and A y per the following equations: ##EQU3## where M=number of revolutions per sample set N=number of sample elements per revolution S=signal at time increment iM+j The sine and cosine tables are then employed by microprocessor 270 to the second set of samples to determine the demodulated phase angle coordinates B x and B y per the same equations. A correction is then made for any error in the assumed speed of the rotated part. The assumed speed is manually entered via keyboard 370 prior to balancing and is based on the arrangement and relative diameters of the drive pulley 330, the rotated part diameter and the stepper motor rate. In the embodiment of FIG. 1, microprocessor 270 provides pulses to a stepper motor 160 at a rate which is controlled by clock 305. This stepper rate is set synchronous with the sample hold circuit 240, which is also set by microprocessor 270. Should there be an difference between the calculated average phase angles of sample sets A and B, this indicates that the actual speed is not synchronous with the assumed speed. Microprocessor 270 makes correction by calculating the actual angular velocity R according to the following equation: ##EQU4## where M=the number of revolutions between the center of a first sample set to the center of a second sample set at the assumed angular velocity B=the unbalance angle of the second sample set in radians A=the unbalance angle of the first sample set in radians T=the total length of time between the center of the first sample set to the center of the second sample set Referring now to FIG. 3, points 140 and 150 correspond to the midpoints of sample period 90 corresponding to sample A and sample period 100 corresponding to sample B, respectively. Because the sample periods 90 and 100 are the same length, the time increment between points 140 and 150 is this same length. Therefore the equation above yields the corrected or actual rotational velocity. The inverse of this equation provides the number of time increments per revolution of the part. Period 110 shown between points 40 and 50 is an arbitrary assumed time period to compensate for the off line computational time required by microprocessor 270 to calculate actual frequencies and is on the order of 500 milliseconds. One skilled in the art would appreciate that this time must be set with reference to the speed of operation of microprocessor 270. The period 120 between points 50 and 60 represents the time required to position the rotating part with the unbalance located at the desired final position such that at point 60 the unbalance location will be a predetermined integral number of revolutions from the stop position and the deceleration may begin. Deceleration is preprogrammed into the microprocessor 270 as a constant rate. Microprocessor 270 is programmed to generate pulses for driving stepper motor 160 for deceleration in accordance with this constant deceleration rate. Calculation of the time to point 60 is performed by calculating the total amount of time between the initial point and the point 60. The initial point may be any point in the measuring cycle at to or after point 20. Typically point 40 is used. Therefore the time to reach point 60 may be calculated by adding the predetermined delay period 110 to the calculated phase angle 120. When the elapsed time equals the calculated time to point 60 the deceleration ramp is begun. Microprocessor 270 is further connected to display 360. In conjunction with the calculation of the place of imbalance and controlling the deceleration of stepper motor 160 to stop the unbalance at the predetermined position, microprocessor 260 also generates signals for display via display 360. As is conventional in such microprocessor control systems, display 360 is employed to display user prompts for initial set up, as for example requesting entry of the desired speed of rotation of the rotating part, information on the status of dynamic balancing operation and so forth. In addition microprocessor 270 computes the magnitude of the unbalance in the rotating part. Display 360 is employed to display this quantity together with the calculated actual rotational speed and the location of the imbalance after completion of the dynamic balancing operation. Display 360 could be formed of light emitting diodes, a liquid crystal display, however the preferred embodiment is a video display monitor formed with a cathode ray tube. In the embodiment illustrated in FIG. 1, the stepper motor rate was controlled in relation to an independently set sampling rate. FIG. 4 illustrates an alternative embodiment. Microprocessor 270 controls the speed of operation of stepper motor 160 by generation of pulses with the appropriate timing. This timing of pulses takes place in relation to the signals from clock 305. A shaft encoder 400 is coupled to the rotating part by belt 410. Rotation of the rotating part causes belt 410 to rotate shaft encoder 400. Shaft encoder 400 in turn generated a signal which indicates the rotary position of shaft encoder 400. Microprocessor 270 employs this signal from shaft encoder 400 to generate the sampling rate signal for sample hold circuit 240. The sample rate is thus asynchronous with the stepper motor rate. In other regards, the apparatus illustrated in FIG. 4 operates in the same manner as previously described.

The balancing machine of the present invention automatically determines the position of unbalance in a rotating part and stops the rotating part with the unbalance position in a predetermined location. Sensors on the bearings holding the rotating part generate signals proportional to the instantaneous unbalance. These signals are filtered and digitized at a sampling rate synchronous with the motor driving the rotation. Two contiguous sets of samples, each set spanning several revolutions of the part, are stored. The X and Y components of the unbalance signal are calculated for each sample set and the actual rotation rate of the part is calculated from the assumed rate and any difference in the phase angle of the unbalance location between the first and second sample sets. These calculations are performed during a calculation interval of predetermined length which follows the sampling. Once this calculation interval has passed and the unbalance location has rotated to the predetermined location a predetermined deceleration of the rotating part is begun. The motor is controlled to decelerate at a predetermined rate.

BACKGROUND OF THE INVENTION The present invention relates to a door and, more particularly, to a door for a motor vehicle including an outer skin and an inner skin. Conventional car doors generally include an outer skin made of metal which simultaneously provides a supportive and stabilizing function, with the outer skin being provided with rigidifying or reinforcing means in an interior of the door. The inner skin, which can be made of a synthetic resin, forms merely a paneling mounted to the outer skin but contributing little if anything to the ruggedness or sturdiness of the door. Thus, a disadvantage of the conventional motor vehicle door resides in the fact that the doors are not only heavy in weight but also relatively expensive to manufacture. Synthetic-resin doors have also been proposed; however, these proposed synthetic-resin doors are unable to meet the desired functional requirements for a vehicle door and also unable to meet the legal requirements. Moreover, the further disadvantages in the proposed synthetic-resin doors resides in the fact that the doors do not have dimensional stability, they shrink, and do not satisfy the demands posed by large-scale series manufacturing. The aim underlying the present invention essentially resides in providing a vehicle door of the aforementioned type which, in spite of a very low weight, is dimensionally stable and can be manufactured in a simple and economical manner. In accordance with advantageous features of the present invention, a motor vehicle door is provided wherein an outer skin and an inner skin of the door are fashioned of synthetic resin shells, with the inner skin being formed as an integral component of a door body including a supportive skeleton of rod-shaped bars. By virtue of the features of the present invention, the inner skin of the vehicle door represents the supportive member rather than, as with conventional doors, the outer skin, and the supportive skeleton is integrated into the inner skin. The supportive skeleton includes rigid and dimensionally stable struts coated by, for example, molding, with the synthetic resin of the inner skin and the outer skin, shaped as separately produced shells, being attached to the inner skin. The outer skin has no supportive function so that, in the case of damage to the outer skin, the structure of the door will not be adversely affected. The surfaces of the inner and outer skins are elastic so that they regain their original shape if subjected to an impact or shock that is not excessive. Since the vehicle door of the present invention consists almost exclusively of a synthetic resin, the door offers, in addition to the advantage of a low weight, a positive feature in as much as the door is not subject to change by rust or corrosion. Moreover, the struts of the supportive skeleton, which can be fashioned of metal, are entirely embedded in the material of the inner skin and surrounded by this material so that they are also effectively protected against adverse environmental influences. In accordance with the present invention, hinge members are mounted at one end of the supportive skeleton, and a lock is arranged at the opposite end. With this arrangement or construction, the ridged and dimensionally stable supportive skeleton takes care of retaining the correct spacial correlation between the lock and the hinge members thereby insuring that, in the case of dimensional changes taking place at the synthetic resin parts, the door will always close in the correct manner, and the function of the lock is not impaired by any such dimensional changes. Preferably, in accordance with the present invention, the outer skin terminates at the lower boundary line of a window, and the supportive skeleton, integral with the inner skin, is fashioned so that it extends completely around the window. The supportive skeleton constitutes not only the supportive and stabilizing part of the vehicle door, but also simultaneously a frame imbedded in the inner skin, insuring the door retains its shape. The outer skin is not attached directly to the supportive skeleton, but rather to the parts of the inner skin surrounding the supportive skeleton and, consequently, it is unnecessary to attach synthetic resin to metal which would require special mounting elements such as, for example, screws, clips, fasteners or the like, and it is possible to, for example, glue the outer skin to the inner skin. In accordance with still further features of the present invention, the skeleton includes at least one essentially horizontally extending strut means extending over an entire length of the door, and the inner skin, above and/or below the strut, recedes to form an arm rest, a door pouch, or the like, or respectively, is provided with openings for enabling a formation of mounting boards. In this manner, it is possible to optimally utilize the inner space of the door and to greatly reduce idle volume or wasted space. Moreover, the interior of the motor vehicle is enlarged or increased to a considerable extent based on the external dimensions of the vehicle. Advantageously, mounting faces for engaging the outer skin are provided at beads of the inner skin surrounding the struts of the supportive skeleton, whereby the outer skin forming a protective shell, can be joined in a simple manner with the inner skin and, consequently, with the supportive skeleton. In order to seal a door gap, the inner skin and/or the outer skin maybe provided with sealing lips integrally molded along a circumference of the vehicle door, and, consequently, it is unnecessary to provide separate sealing lips of foreign materials since the sealing action is performed or accomplished by the material of the inner skin fashioned to be correspondingly thin at the sealing lips. The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken into connection with the accompanying drawings which show, for the purposes of illustration only, several embodiments in accordance with the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exterior side view of a vehicle door constructed in accordance with the present invention; FIG. 2 is a schematic interior view of the vehicle door of FIG. 1; FIG. 3 is an end view taken in a direction of the arrow III in FIG. 2; FIG. 4 is an end view taken in a direction of the arrow IV in FIG. 2; FIG. 5 is a cross-sectional view taken along a line V--V in FIG. 2; FIG. 6 is a cross-sectional view taken along a line VI--VI in FIG. 2; FIG. 7 is an enlarged view of a detail designated VII in FIG. 6; FIG. 8 is a cross-sectional view taken along a line VIII--VIII of FIG. 2; FIG. 9 is a cross-sectional view taken along a line IX--IX in FIG. 2; FIG. 10 is a cross-sectional view taken along a line X--X in FIG. 2; FIG. 11 is a schematic view of a supportive skeleton of a vehicle door constructed in accordance with the present invention; FIG. 12 is an end view of the supportive skeleton taken in a direction of an arrow XII in FIG. 11; FIG. 13 is an end view of the supportive skeleton taken in a direction of an arrow XIII in FIG. 11; FIG. 14 is a cross-sectional view taken along a line XIV--XIV in FIG. 11, with an additional illustration of an outer skin; FIG. 15 is a cross-sectional view taken along a line XV--XV of FIG. 11, with an additional illustration of the outer skin; FIG. 16 is a side view of the outer skin for a vehicle door constructed in accordance with the present invention; and FIG. 17 is a profile view of the outer skin of FIG. 16. DETAILED DESCRIPTION Referring now to the drawings wherein like reference numerals are used throughout the various views to designate like parts and, more particularly, to FIG. 1, according to this figure, a vehicle door adapted to be mounted on a passenger motor vehicle, includes a supportive door body generally designated by the reference numeral 10 to which an outer skin generally designated by the reference numeral 12 is attached beneath a window opening generally designated by the reference numeral 11. Struts or frame members 13 define the window opening 11 toward the top and laterally are parts of the door body 10. The window opening 11 includes a window pane 14 fixably connected to the door body 10 and occupying or covering a largest part of the window opening 11, and a movable window part or pane 15 adapted to be selectively raised and lowered from and into an interior of the vehicle door in order to open at least a portion of the window opening. A forward corner of the fixed window pane 14, which converges pointedly, includes a mounting plate 16 to which a rear view mirror can be attached, with the mounting plate 16 being firmly joined to the door body 10. A door handle 17 and keyhole 18 of a lock are conventionally mounted at the outer skin 12, which is fashioned as a projecting shell. The outer skin 12 terminates approximately at a bottom edge of the window 14 and includes, in a lower zone or area thereof, a longitudinally extending impact protection molding 19 in the form of a hollow bead. As shown in FIGS. 16 and 17, the outer skin 12 is fashioned as a separately manufactured shell produced from a synthetic resin and subsequently fastened to the door body 10. As shown most clearly in FIG. 2, the door body 10 includes a supporting skeleton 20 which, as shown in FIG. 11, is fashioned of a plurality of rigid struts formed preferably of, for example, metal, with a cross-section of the rigid struts being, for example, tubular. The supportive skeleton 20 includes a closed frame 21, a contour of which corresponds to that of the vehicle door. In the closed frame 21, below the opening 11 for the window, a longitudinal strut 22 extends which runs along an entire length of the closed frame 21, and the ends of which are connected to vertical struts of the closed frame 21. Two additional longitudinal struts 23, 24, extend essentially or substantially horizontally in a region or area between the longitudinal strut 22 and the lower frame strut 25. Each of the longitudinal struts 23, 24, extends from one hinge member 26 or 27 at one end of the closed frame 21 to the lock 28 at the other end of the closed frame 21. The longitudinal struts 23, 24, are connected with each other by transverse struts 29, 30, 31, in order to form within the closed frame 21 a rigid carrier extending from the hinge members 26, 27, to the lock 28. The hinge members 26, 27, are attached to two parallel vertical struts 32, 33, constituting the forward end of the closed frame 21. The strut 32 is located in the major plane of the frame 21, whereas the strut 33 is oriented away therefrom towards the interior of the vehicle. The hinge members 26, 27, each of which exhibits a forwardly projecting hinge arm 34 (FIG. 14) are attached to the struts 32, 33. A mounting bridge 35 extends in the center between the hinge members 26, 27, between the struts 32, 33, with the mounting bridge 35 having a passage opening for a holding tongue 36 projecting into the interior of the vehicle door and defining the open position of the door. Moreover, a bearing 38 is provided for the pivoting window 15 and mounting means 39 for a window operating device or crank mechanism (not shown) are attached to the closed frame 21. The supportive skeleton 20, with the exception of the mounting plate 16, hinge members 26, 27 and lock 28, is entirely coated by molding by the synthetic resin of the inner skin 40 and embedded in the synthetic resin. As shown most clearly in FIGS. 5-10, all of the struts of the supportive skeleton 20 are entirely encompassed by the synthetic resin of inner skin 40. The inner skin 40 furthermore is fashioned as a shell 41 extending essentially over the entire area beneath a bottom edge of the window 14 (FIG. 2). A supporting trough or depression 42 for insertion or accommodation of the elbow rest is integrally molded within the shell 41, and, in a lower zone or area of the door body 10, a storage trough or depression 43 (FIGS. 2, 6) is molded in place. The troughs or depressions 42, 43, arranged above and below the beam formed by the longitudinal struts 23, 24, project from an interior of the vehicle toward the outside, that is, the troughs or depressions 42, 43, bulge or protrude in the direction toward the outer skin 12 and are in overlapping relationship, as seen from a top view, with the longitudinal struts 23, 24. A lateral cheek 44 is disposed in front of the storage trough 43 (FIG. 6), with the lateral cheek 44 projecting into the interior of the vehicle and defining the storage pouch formed in the storage trough 43. Furthermore, mounting bores or apertures 46 (FIG. 2) are provided in the inner skin 40. An operating mechanism 47 for the door lock 28, attached to the supportive skeleton 20, is arranged behind one of the mounting bores or apertures 46, with a linkage 48 extending from the operating mechanism 47 through the interior of the vehicle door 10 to the door lock 28. The inner skin 40 is partially covered with a door paneling 49 (FIG. 10) covering the mounting bores or apertures 46. The attachment of the outer skin 12 to the inner skin 40 is most clearly shown in FIGS. 6, 7. The struts of the supportive skeleton 20 include hollow profile members surrounded by beads 50 of the inner skin 40, and the beads 50 include an outwardly oriented contact face 51 which is brought into flat engagement with the outer skin 12. A shallow indentation for accommodating an adhesive media is provided in each contact face 51. On both sides of the contact face 51, the outer skin 12 is provided with webs 52 serving for positioning the outer skin 12 with respect to the inner skin 40 and for preventing an escape of the adhesive media. As shown in FIG. 6, a sealing strip 54 is attached to a stepping sill 53 of the vehicle, with the sealing strip 54 being contacted by a step shoulder generally designated by the reference numeral 45 of the inner skin 40 when the vehicle door 10 is closed. Similar sealing strips 54 are provided at the remaining edges of the frame of the door 10. The outer skin 21 and/or the inner skin 40 additionally include integrally molded or separately attached sealing lips 55 which contact a boundary of a door opening of the vehicle side. As shown in FIG. 5, the movable or pivoting window part 15 is movable or pivotable about a bearing 38 and is adapted to be lowered through a window gap 56 into an interior of the vehicle door 10. For the sake of clarity, the conventional operating mechanism for moving the movable window part 15 which, for example, may be a mechanical construction or a cerval operated mechanism, are not illustrated in detail for the sake of clarity. The window gap 56 is defined on both sides of the pivotable window part 15 by sealing strips 57, 58, with the sealing strip 57 being mounted to a top edge of the outer skin 12, whereas, the opposite sealing strip 58 is attached to the head 50 of the longitudinal strut 22. FIG. 10 provides an illustrated example of an attachment of the fixed pane 14, a lower edge of which, is secured by an adhesive media such as, for example, glue, to an outside of the upper end of the outer skin 12. The upper end of the upper skin 12, is, in turn, glued the mounting face 51 of the bead 50 of the longitudinal strut 22. On a rearward vertical strut 21, the fixed window pane 14, is, as shown in FIG. 9, additionally secured by, for example, an adhesive such as glue to a mounting face 51 with the interposition of a gasket or the like. As can readily be appreciated, the outer skin need not be necessarily be glued or cemented to the inner skin 40 but rather may be attached by faster means such as, for example, screws, clips, spot welding, or the like. While I have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is succeptable to numerous changes and modifications, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such modifications as are encompassed by the scope of the appended claims.

A motor vehicle door including a supportive and dimensionally stable skeleton which, together with an inner shell, constitutes a one-piece door body, to which an outer shell is attached as a separate element. The inner shell and the outer shell are fashioned from a synthetic resin and the supportive skeleton connects hinge members with the door lock of the door. The inner skin is provided with at least one of troughs or depressions and mounting bores or apertures.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a sense amplifier of a memory device, and more particularly, to a method and circuit for automatically controlling an operation of a sense amplifier in correspondence with variations of operating voltage and frequency of a memory device. 2. Description of the Related Art FIG. 1 is a diagram illustrating a read and write operations in a general memory device. As shown in FIG. 1 , during a write operation, data applied through an input/output data pad is transferred to a bitline sense amplifier through a data input buffer and a data input register. While, during a read operation, cell data amplified by the bitline sense amplifier is transferred to the input/output data pad through a data sense amplifier, a pipe register, and a data output buffer. In FIG. 1 , signal Yi is a pulse signal to connect the bitline sense amplifier with the data sense amplifier so as to control an operation of a data bus. While the signal Yi controlling the data bus is being enabled, the write data is transferred to the bitline sense amplifier from a write driver and the read data is transferred to the data sense amplifier from the bitline sense amplifier. It is advantageous to make a pulse width of the signal Yi wider in transferring valid data in an active operation mode (the read or write operation). It is also efficient to improve the performance of tDPL (a time from when a CAS pulse signal is generated internally by a write command to when a precharge pulse signal is generated internally by a precharge command) because the time parameter tDPL contributes to making restoring facilities of data better. Therefore, it is usual to establish the pulse width of the signal Yi as wider as possible within the permissible range and to use it with shrinking down in accordance with operational conditions. In reference, as an operating frequency of a memory device increases (i.e., a clock cycle period is shorter), a permissible pulse width of the signal Yi becomes narrower. Meanwhile, as the signal Yi is made from responding to a read/write strobe pulse signal rdwtatbzp 13 output from a read/write strobe pulse generator, hereinafter will be explained about the read/write strobe pulse generator. FIG. 2A illustrates an example of a conventional read/write strobe pulse generator and FIG. 2B is a waveform diagram of signals used in the circuit shown in FIG. 2A . In FIG. 2A , signals extyp 8 and icasp 6 are signals to make a data transmission line short or open, so as to read data to a peripheral circuit from a cell array of the memory device or to write data in the cell array of the memory device from a peripheral circuit. For information, it's named a core section for the range including a memory cell and a bitline sense amplifier and the rest a peripheral circuit. In detail, the signal extyp 8 is a pulse signal that is generated in sync with a clock signal when a read or write command (burst command) is applied to the memory device. And, the signal icasp 6 is a signal to be used in operating the memory device by generating a self-burst operation command that is established with a burst length set by an MRS (mode register set) mode from a clock time later by one clock cycle period than a clock time when a read or write command is applied from the external. The signal rdwtstbzp 13 is a signal to be active for the burst length set by the MRS mode, being activated in sync with the signals of the burst operation command (external=exryp 8 & internal=icasp 61 ). In other words, the signal rdwtstbzp 13 is to be used to inform an activation time of the input/output sense amplifier in amplifying and transferring data, which is to be sent to a peripheral circuit from a core circuit region, to the data output buffer, resetting the data transmission line of the peripheral circuit after completing the data amplification and transmission by the sense amplifier. A signal pwrup is a signal to set an initial data value, retaining low level after falling down to low level from high level. Signal term_z is a signal used in a test mode being held on low level during a normal operation. A signal tm_clkpulsez is used in a test mode. Such signals will be described in detail in conjunction with embodiments of the present invention hereinafter. A circuit operation of FIG. 2A is illustrated, as follows, with reference to the waveform diagram of FIG. 2B . As illustrated in FIG. 2B , when the read/write command is applied to the memory device in sync with the clock signal clock, the pulse signal extyp 8 is generated. If the pulse signal extyp 8 is enabled, a plurality of pulse signals icasp 6 is generated in sync with the next clocks in sequence. As shown in FIG. 2B , the read/write strobe pulse signal rdwtstbzp 13 is generated in sync with rising edges of the pulse signals extyp 8 and icasp 6 . Here, in the conventional circuit shown in FIG. 2A , it can be seen that the pulse width of the read/write strobe pulse signal rdwtstbzp 13 generated from a pulse width adjusting circuit 200 is fixed nevertheless of the operating frequency of the memory device. Here, a delay time from a node A from a node D is determined by a delay circuit 20 . As the delay time of the delay circuit 20 in the pulse width adjusting circuit 200 is fixed, the pulse width of the signal outputted from the pulse width adjusting circuit 200 is always constant without regarding to the operating frequency of the memory device. But, it needs to adjust a pulse width of the read/write strobe pulse signal rdwtstbzp 13 when an operating frequency of the memory device varies. In a conventional art, while the delay time of the delay circuit 20 is variable by modifying a metal option during a FIB process when an operating frequency of the memory device varies, it needs much costs and times. In addition, with the conventional art, there is no way to correct a variation of the pulse width of the read/write strobe pulse signal rdwtstbzp 13 when an operation voltage of the memory device varies. SUMMARY OF THE INVENTION Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a method of automatically controlling a pulse width of a signal output from a pulse width adjusting circuit in accordance with variation of an operating frequency of a memory device. Another object of the present invention is to provide a method of controlling a pulse width of a read/write strobe pulse signal rdwtstbzp 13 in correspondence with variation of an external clock signal. In order to achieve the above object, according to one aspect of the present invention, there is provided a read/write strobe pulse generator generally usable even when an operating frequency of a memory device varies. According to another aspect of the present invention, there is also provided a method of delaying a signal outputted from a read/write strobe pulse generator by applying an external address signal and controlling a width of the read/write pulse. According to still another aspect of the present invention, what's provided is a method of controlling a pulse width of a read/write strobe pulse signal rdwtstbzp 13 in accordance with variation of an operation voltage of a memory device. By the features of the present invention, an embodiment of the present invention is a circuit for controlling an enabling period of an internal control signal in accordance with variation of an operating frequency in a memory device, which comprises a pulse width adjusting circuit for changing a pulse width of an input signal in accordance with the operating frequency; a signal transmission circuit for buffing a signal outputted from the pulse width adjusting circuit; and an output circuit for outputting a first signal to control an operation of a data bus of the memory device in response to a signal output from the signal transmission circuit. In this embodiment, the pulse width adjusting circuit comprises a first delay circuit and a NAND gate, in which the NAND gate receives the input signal and an output signal of the first delay circuit, and the first delay circuit receives the input signal and a clock signal of the memory device and adjusts a delay time in accordance with a frequency of the clock signal until the input signal is applied to an input terminal of the NAND gate. In this embodiment, as a cycle period of the clock signal is shorter, a pulse width of the first signal is narrower. Another embodiment of the present invention is a method for controlling an enabling period of an internal control signal in accordance with variation of an operating frequency in a memory device, which comprises the steps of: (a) receiving an input signal; (b) delaying the input signal for a predetermined time; (c) operating the input signal and a signal delayed from the input signal in a NAND logic; and (d) outputting a result of operating the NAND logic. In this embodiment, it further comprises the step of: (b-1) determining the predetermined time of the step (b) in accordance with a frequency of a clock signal of the memory device. In this embodiment, as the frequency of the clock signal increases, a pulse width of a signal outputted from the step (d) is narrower. In this embodiment, it further comprises the step of (b-2) more reducing a pulse width of a signal outputted from the step (d) by using an address signal of the memory device. BRIEF DESCRIPTION OF THE DRAWINGS The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which: FIG. 1 is a diagram illustrating a read and write operation in a general memory device; FIG. 2A illustrates an example of a conventional read/write strobe pulse generator; FIG. 2B is a waveform diagram of signals used in the circuit shown in FIG. 2A ; FIG. 3 illustrates an exemplary embodiment of a read/write strobe pulse generator in accordance with the present invention; FIGS. 4 through 10 illustrate embodiments of a delay circuit 30 in a pulse width adjusting circuit 300 shown in FIG. 3 ; FIG. 11 is an operational timing diagram of the conventional circuit shown in FIG. 2A ; FIG. 12 is a waveform diagram illustrating a pulse width variation of the read/write strobe pulse signal rdwtstbzp 13 output from the conventional circuit of FIG. 2A when an operation voltage vdd of a memory device varies; FIG. 13 is a waveform diagram of signals used in the circuit of the present invention, specifically an exemplary waveform diagram of signals used in the circuit of FIG. 5 ; FIG. 14 is a diagram illustrating a procedure of changing logical levels of flag signals Flag 1 and Flag 2 in accordance with a frequency of a clock signal clk_in; FIG. 15 is a diagram illustrating a waveform of an output signal rdwtstbzp 13 when paths C 1 and C 2 shown in FIG. 10 are used therein; and FIG. 16 is a waveform diagram illustrating a variation of the output signal rdwtstbzp 13 in accordance with a variation of the operation voltage. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. FIG. 3 illustrates an exemplary embodiment of a read/write strobe pulse generator in accordance with the present invention. The circuit of FIG. 3 is different from the circuit of FIG. 2A in that a delay circuit 30 in a pulse width adjusting circuit 300 is controlled by a clock signal clk_in and address signals add_ 0 and add_ 1 . The circuit of FIG. 3 is comprised of an input signal receiver 310 , a pulse width adjusting circuit 300 , a signal transmission circuit 320 , a test mode circuit 330 , and an output circuit 340 . The input signal receiver 310 includes inverters INV 30 and INV 31 , and a NAND gate NAND 30 . An input signal extyp 8 is applied to the inverter INV 30 and an input signal icasp 6 is applied to the inverter INV 31 . Output signals of the inverters INV 30 and INV 31 are applied to the NAND gate NAND 30 . The pulse width adjusting circuit 300 includes the delay circuit 30 and the NAND gate NAND 31 . The delay circuit 30 receives an output signal of the NAND gate NAND 30 , a test mode signal tmz_l, the clock signal clk_in, and the address signals add_ 0 and add_ 1 . The NAND gate NAND 31 receives the output signal of the NAND gate NAND 30 and an output signal of the delay circuit 30 . An output signal of the pulse width adjusting circuit 300 is an output signal of the NAND gate NAND 31 . A delay time from a node A to a node D is determined by the delay circuit 30 . The delay time by the delay circuit 30 is adjustable by means of a frequency of the clock signal clk_in and the address signals add_ 0 and add_ 1 . In reference, the test mode signal tmz_l is a control signal to determine whether or not a current operation is a test mode, retaining low level during the test mode while retaining high level during a normal operation mode. The add_ 0 and add_ 1 are external address signals to be used in the test operation mode. Functions of the signals will be explained relative to the detail circuit hereinafter. The signal transmission circuit 320 includes inverters INV 32 , INV 33 , and INV 34 that, receive and buff the signal outputted from the pulse width adjusting circuit 300 . The test mode circuit 330 includes transistors P 31 , P 32 , and N 31 and a latch circuit 301 . As illustrated in FIG. 3 , the PMOS transistor P 31 and the NMOS transistor N 31 are connected between a power source voltage and a ground in series. The PMOS transistor P 32 is connected between the power source voltage and a node NODE 31 . The latch 301 temporarily stores a signal of the node NODE 31 . Here, termz is a signal used in the test mode and the signal pwrup is that as stated in FIG. 2A . The output circuit 340 includes a NAND gate 302 and inverters INV 35 and INV 36 . The NAND gate 302 receives an output signal of the inverter INV 34 , the signal termz, and an output signal of the latch circuit 301 . The signal termz functions to inhibit the read/write strobe pulse signal rdwtstbzp 13 . An output signal of the NAND gate 302 is applied to the inverters INV 35 and INV 36 serially connected from each other. An output signal of the inverter INV 36 as an output signal of the output circuit 340 becomes the read/write strobe pulse signal rdwtstbzp 13 . In a normal operation, the input signals extyp 8 and icasp 6 are generated into the read/write strobe pulse signal rdwtstbzp 13 after a predetermined time. During this, it is possible for the pulse width adjusting circuit 300 to control a pulse width of the read/write strobe pulse signal rdwtstbzp 13 by modifying a pulse width of the input signals extyp 8 and icasp 6 with using the clock signal clk_in that varies dependent on variation of an operating frequency. FIGS. 4 through 10 illustrate embodiments of the delay circuit 30 in the pulse width adjusting circuit 300 shown in FIG. 3 . As described later, the clock signal clk_in is applied to the delay circuit 30 so as to detect an operating frequency of the memory device. And, at the beginning of the test mode, the test mode signal tmz_l of low level is applied thereto. Also, at the beginning of the test mode, the address signals add_ 0 and add_ 1 are applied to further tune a delay time. In reference, the node A and D shown in FIG. 3 correspond to those node A and D shown in FIG. 4 . Hereinafter, it will be described in more detail about the circuits shown in FIGS. 4 through 10 . FIG. 4 is a block diagram illustrating an internal structure of the delay circuit shown in FIG. 3 in detail. As illustrated in FIG. 4 , the delay circuit 30 in FIG. 3 is comprised of delay units 401 , 402 , and 403 , a frequency detector 404 , a voltage detector 405 , a test mode address signal receiver 406 , and a reference voltage generator 407 . Exemplary circuits of the frequency detector 404 , the voltage detector 405 , and the test mode address signal receiver 406 are shown in FIGS. 4 , 5 , and 6 , respectively. In FIG. 4 , the frequency detector 404 receives the clock signal clk_in and then outputs operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z which control a delay path of the delay unit 401 . Logical levels of the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z vary in accordance with a frequency of the clock signal clk_in. The delay path from the node A to the node D is alterable in accordance with a frequency of the clock signal clk_in. The reference voltage generator 407 is enabled by the power-up signal pwrup, outputting a plurality of reference voltages vref_ 0 and vref_ 1 . The reference voltage generator 407 is a circuit capable of outputting stable reference voltages without affecting from an operation voltage, which is constructed with circuit structures well known by those skilled in this art. The voltage detector 405 detects a variation of the operation voltage vdd by comparing the operation voltage vdd to the reference voltages vref_ 0 and vref_ 1 . The voltage detector 405 outputs a plurality of voltage selection signals vsel_ 0 z , vsel_ 1 z , and vsel_ 2 z to control the delay path of the delay unit 402 . Thus, delay times of delay paths C 1 are determined by logical level of the voltage selection signals vsel_ 0 z , vsel_ 1 z , and vsel_ 2 z. In accordance with a logical level of the test mode signal tmz_ 1 , a signal of the node C 1 can be transferred to the node D directly or through the delay unit 403 . When the test mode signal tmz_ 1 is high level, the signal of the node C 1 is transferred directly to the node D. The test mode address signal receiver 406 receives an address signal and outputs a plurality of selection signals sel_ 0 z , sel_ 1 z , sel_ 2 z , and sel_ 3 z . Responding to the selection signals sel_ 0 z , sel_ 1 z , sel_ 2 z , and sel_ 3 z , a delay time of the delay unit 403 is adjusted. As aforementioned, the delay unit 403 is used as a delay path in the test mode, which means that it is possible to conduct an additional delay tuning operation by using the address signal when the test mode signal tmz_ 1 is being low level. Exemplary features of the components shown in FIG. 4 are illustrated in FIGS. 5 through 10 . FIG. 5 illustrates, as an example of the frequency detector 404 shown in FIG. 4 , a circuit for outputting the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z that determine a range of the operating frequency of the memory device in response to the clock signal clk_in. In FIG. 5 , after detecting an operating frequency of the memory device by generating a plurality of internal signals dlic 4 _ref, dlic 4 , dlic 4 d 1 , dlic 4 d 2 , cmp, flag_ 1 , and flag_ 2 in response to the clock signal clk_in, the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z are finally outputted therefrom to be determined the range of the operating frequency of the memory device. As illustrated in FIG. 5 , the clock signal clk_in is applied to a frequency divider 500 . The divider 500 outputs the frequency dividing signal dlic 4 _ref having a period longer than that of the clock signal clk_in. As shown in the waveform diagram of FIG. 13 , a cycle period of the frequency dividing signal dlic 4 _ref is four times of that of the clock signal clk_in. At this case, a low level term of the frequency dividing signal dlic 4 _ref is identical to the cycle period tCLK of the clock signal clk_in. However, the cycle period of the frequency dividing signal dlic 4 _ref may be alterable by those skilled in this art. The frequency dividing signal dlic 4 _ref is outputted with phase inversion after being delayed by a buffer circuit 501 composed of odd-numbered inverters. The phase-inversed frequency dividing signal is denoted as dlic 4 . Waveforms of those signals dlic 4 _ref and dlic 4 are shown in FIG. 13 . In FIG. 5 , the frequency dividing signal dlic 4 _ref and the phase-inversed frequency dividing signal dlic 4 are applied to a NAND gate NAND 51 . An output signal from the NAND gate NAND 51 is applied to a delay unit 506 and a NOR gate NOR 51 . The NOR gate NOR 51 receives the output signal of the NAND gate NAND 51 and an output signal of the delay unit 506 , and outputs the pulse signal cmp. The output signal cmp of the NOR gate NOR 51 is illustrated in FIG. 13 . The phase-inversed frequency dividing signal dlic 4 is applied to delay units delay_A and delay_B. Here, there is a difference between delay times of the delay units delay_A and delay_B. Output signals of the delay units delay_A and delay_B are represented to as dlic 4 d 1 and dlic 4 d 2 , respectively. The output signal dlic 4 d 1 of the delay unit delay_A and the frequency dividing signal dlic 4 _ref are applied to a flipflop circuit 502 . The flipflop circuit 502 is constructed of two NAND gates input/output terminals of which are cross-coupled each other. Output signals from two output terminals of the flipflop circuit 502 are e and f, respectively. The output signal dlic 4 d 2 of the delay unit delay_B and the frequency dividing signal dlic 4 _ref are applied to a flipflop circuit 503 . The flipflop circuit 503 is constructed of two NAND gates input/output terminals of which are cross-coupled each other. Output signals from two output terminals of the flipflop circuit 503 are g and h, respectively. A NAND gate NAND 52 receives the output signal cmp of the NOR gate NOR 51 and the output signal e of the flip-flop circuit 502 . A NAND gate NAND 53 receives the output signal cmp of the NOR gate NOR 51 and the output signal if of the flipflop circuit 502 . A NAND gate NAND 54 receives the output signal cmp and the output signal g of the flip-flop circuit 503 . A NAND gate NAND 55 receives the output signal cmp of the NOR gate NOR 51 and the output signal h of the flipflop circuit 503 . Output signals of the NAND gates NAND 52 and NAND 53 are applied to the flipflop circuit 504 . The flipflop circuit 504 is constructed of two NAND gates input/output terminals of which are cross-coupled each other. An output signal of the flipflop circuit 504 is represented to as a flag signal flag_ 1 . Output signals of the NAND gates NAND 54 and NAND 55 are applied to the flipflop circuit 505 . The flipflop circuit 505 is constructed of two NAND gates input/output terminals of which are cross-coupled each other. An output signal of the flipflop circuit 505 is represented to as a flag signal flag_ 2 . In reference, when a delay time by delay unit 508 is longer than that by delay unit 507 (i.e., delay_A<delay_B), logical levels of the flag signals are as follows. If tCLK<delay_A, the flag signals flag_ 1 and flag_ 2 are all low levels. Here, tCLK is a cycle period of the clock signal clk_in. If delay_A<tCLK<delay_B, the flag signal flag_ 1 is high level while the flag signal flag_ 2 is low level. If tCLK>delay_B, the flag signal flag_ 1 and flag_ 2 are all high levels. In FIG. 5 , the flag signals flag_ 1 and flag_ 2 are applied each to inverters INV 51 and INV 52 . Output signals of the inverters INV 51 and INV 52 are applied to NAND gate NAND 56 . The NAND gate NAND 56 outputs the operating frequency detection signal dec_ 0 z. Next, the flag signal flag_ 2 is applied to an inverter INV 53 . An output signal of the inverter INV 53 and the flag signal flag_ 1 are applied to a NAND gate NAND 57 . The NAND gate NAND 57 outputs the operating frequency detection signal dec_ 1 z. Finally, the flag signals flag_ 1 and flag_ 2 are applied to a NAND gate NAND 58 . The NAND gate NAND 58 outputs the operating frequency detection signal dec_ 1 z. FIG. 6 is a circuit for outputting voltage selection signals vsel_ 2 z , vsel_ 1 z , and vsel_ 0 z so as to control a delay time of an input signal in accordance with variation of an operation voltage. The voltage selection signals generated in FIG. 6 are used for selecting a delay path of a circuit shown in FIG. 9 . FIG. 6 illustrates two differential amplifying comparators. As shown in FIG. 6 , there are a differential amplifying comparator for comparing the operation voltage vdd to the reference voltage vref_ 0 and another differential amplifying comparator for comparing the operation voltage vdd to the reference voltage vref_ 1 . The reference voltage vref_ 0 is lower than the reference voltage vref_ 1 (vref_ 0 <vref_ 1 ). As noticed from FIG. 6 , if vdd<vref_ 0 , output signals DET_ 0 and DET_ 1 of the differential amplifying comparator are all high levels. If vref_ 0 <vdd<vref_ 1 , the output signal DET_ 0 is high level while the output signal DET_ 1 is low level. If vdd>vref_ 1 , the output signals DET_ 0 and DET_ 1 of the differential amplifying comparator are all low levels. The output signal DET_ 0 of the differential amplifying comparator is applied to an inverter INV 61 and an output signal of the inverter INV 61 is DET_ 0 b . The output signal DET_ 1 of the differential amplifying comparator is applied to an inverter INV 62 and an output signal of the inverter INV 62 is DET_ 1 b. In FIG. 6 , NAND gate NAND 61 receives the signals DET_ 0 b and DET_ 1 b and an output signal of the NAND gate NAND 61 is the voltage selection signal vsel_ 2 z. A NAND gate NAND 62 receives the signals DET_ 0 b and DET_ 1 b and an output signal of the NAND gate NAND 62 is the voltage selection signal vsel_ 1 z. A NAND gate NAND 63 receives the signals DET_ 0 and DET_ 1 and an output signal of the NAND gate NAND 63 is the voltage selection signal vsel_ 0 z. As can be seen by FIG. 6 , the circuits of FIG. 6 are provided to detect a fluctuation of the operation voltage vdd relative to the reference voltages vref_ 0 and vref_ 1 . FIG. 7 illustrates circuit elements for generating the selection signals sel_ 3 z , sel_ 2 z , sel_ 1 z , and sel_ 0 z to designate delay paths in response to the address signals add_ 0 and add_ 1 . As illustrated in FIG. 7 , an inverter INV 71 receiving the address signal add_ 0 outputs a phase-inversed address signal add_ 0 b . An inverter INV 72 receiving the address signal add_ 1 outputs phase-inversed address signal add_ 1 b . Next, the delay path selection signals sel_ 3 z , sel_ 2 z , sel_ 1 z , and sel_ 0 z are generated resulting from logical combinations with the address signals. That is, the NAND gate NAND 71 receives the address signals add_ 0 b and add_ 1 b and then outputs the selection signal sel_ 3 z . The NAND gate NAND 72 receives the address signals add_ 0 b and add_ 1 and then outputs the selection signal sel_ 2 z . The NAND gate NAND 73 receives the address signals add_ 0 and add_ 1 b and then outputs the selection signal sel_ 1 z . The NAND gate NAND 74 receives the address signals add_ 0 and add_ 1 and then outputs the selection signal sel_ 0 z. FIG. 8 , as an exemplary feature of the delay circuit 30 , shows an example of a circuit for selecting a delay path of an input signal with using the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z that are generated in FIG. 5 . The circuit of FIG. 8 comprises a plurality of delay units 801 , 802 , 803 , and 804 , and switching units 811 , 812 , 814 , 815 , and 816 which are controlled by the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z . Each of modulation circuits 817 and 818 is composed of a NAND gate and an inverter which are connected in series. Input terminals of the modulation circuits 817 and 818 receive a signal of the node A. In FIG. 8 , the whole delay time is taken from the node A to the node D. Here, the nodes A and D of FIG. 8 are the same with the nodes A and D of FIG. 3 . A signal input through the node A of FIG. 8 is an output signal from the input signal receiver 310 of FIG. 3 , which is the signal extyp 8 or icasp 6 . In FIG. 8 , the operating frequency detection signals dec_ 1 z and dec_ 2 z control turn-on/off operations of the switching units 811 and 814 . The operating frequency detection signal dec_ 0 z controls a turn-on/off operation of the switching unit 812 . The operating frequency detection signal dec_ 2 z controls a turn-on/off operation of the switching unit 815 . The test mode signal tmz_ 1 controls a turn-on/off operation of the switching unit 816 . In operation, when a NAND gate NAND 81 receiving the operating frequency detection signals dec_ 1 z and dec- 2 z outputs a high-level output signal, the switching units 811 and 814 are turned on. Thus, the input signal received through the node A passes by way of the delay unit 801 , the modulation circuit 817 , the delay unit 802 , the modulation circuit 818 , and the switching unit 814 , in sequence. Here, the switching unit 815 is controlled by the operating frequency detection signal dec_ 2 z . Therefore, while a signal passing through the switching unit 814 is transferred to the node B through the delay unit 804 when the operating frequency detection signal dec_ 2 z is low level, it is transferred directly to the node C when the operating frequency detection signal dec_ 2 z is high level. In operation, when the switching unit 812 is turned on in response to the operating frequency detection signal dec_ 0 z , the input signal received through the node A passes by way of the delay unit 801 , the modulation circuit 817 , and the switching unit 812 , in sequence. Here, the switching unit 815 is controlled by the operating frequency detection signal dec_ 2 z . While a signal passing through the switching unit 812 is transferred to the node B through the delay unit 804 when the operating frequency detection signal dec_ 2 z is low level, it is transferred directly to the node B when the operating frequency detection signal dec_ 2 z is high level. Next, a signal on the node B is transferred to the node C 1 through the switching unit 816 . A signal at the node C 1 may be transferred to the node D through the switching unit 816 directly or transferred to the node D through the delay path of C 1 -C 2 -D. Hereinafter, it will be described in detail about the alternative delaying operations. Referring to FIG. 8 , the switching unit 816 is turned on/off by the test mode signal tmz_ 1 . In a test mode, the test mode signal tmz_ 1 retains low level. In a normal operation mode, the test mode signal retains high level. In the normal operation mode, a signal on the node C 1 is forwarded to a delay path of C 1 -D. In other words, the signal on the node C 1 is transferred to the node D by way of the switching unit 816 , an inverter INV 81 , and a NAND gate NAND 83 . Here, the NAND gate NAND 83 receives signals output from the inverter INV 81 and the node A. In the test mode, the signal on the node C 1 is transferred to the node C 2 through the circuit shown in FIG. 10 . The signal transferred to the node C 2 is transferred to the node D by way of the switching unit 816 , the inverter INV 81 , and the NAND gate NAND 83 . FIG. 9 illustrates a circuit disposed on a delay path of B-C 1 . The delay path circuit of FIG. 9 is selected by the voltage selection signals vsel_ 2 z , vsel_ 1 z , and vsel_ 0 z which are generated in FIG. 6 . As illustrated, the circuit of FIG. 9 is comprised of delay units 901 , 902 , and 903 , switching units 911 , 912 , 913 , and 914 , and NAND gates NAND 91 and NAND 92 . The NAND gates NAND 91 and NAND 92 receive the voltage selection signals vsel_ 1 z and vsel_ 0 z . The switching unit 911 is turned on/off by an output signal of the NAND gate NAND 91 . The switching unit 913 is turned on/off by an output signal of the NAND gate NAND 92 . The switching unit 912 is turned on/off by the voltage selection signal vsel_ 2 z . The switching unit 914 is turned on/off by the voltage selection signal vsel_ 0 z. In operation, if the switching units 911 and 913 are turned on, a signal on the node B passes through the delay unit 901 , the switching unit 911 , the delay unit 911 , and the switching unit 913 , in sequence. A delay path of the signal passing through the switching unit 913 is alterable in accordance with the voltage selection signal vsel_ 0 z . That is, when the voltage selection signal vsel_ 0 z is high level, the signal passing through the switching unit 913 is transferred to the node C 1 by way of the switching unit 914 . Otherwise, when the voltage selection signal vsel_ 0 z is low level, the signal passing through the switching unit 913 is transferred to the node C 1 by way of the delay unit 903 and the switching unit 914 . In operation, if the switching unit 912 is turned on, a signal on the node B passes through the delay unit 901 and the switching unit 912 . A delay path of the signal passing through the switching unit 912 is alterable in accordance with the voltage selection signal vsel_ 0 z . That is, when the voltage selection signal vsel_ 0 z is high level, the signal passing through the switching unit 912 is transferred to the node C 1 by way of the switching unit 914 . Otherwise, when the voltage selection signal vsel_ 0 z is low level, the signal passing through the switching unit 912 is transferred to the node C 1 by way of the delay unit 903 and the switching unit 914 . FIG. 10 , as an exemplary feature of a circuit interposed between the nodes C 1 and C 2 , illustrates a circuit for controlling a delay rate with using address signals in a test mode (when tmz_ 1 of FIG. 8 is low level). The circuit of FIG. 10 is comprised of delay units 1000 , 1001 , 1002 , 1003 , and 1004 , switching units 1011 , 1012 , 1013 , 1014 , and 1015 which are controlled by the selection signals sel_ 3 z , sel_ 2 z , sel_ 1 z , and sel_ 0 z , and conversion circuits 1017 and 1018 . Each of the conversion circuits 1017 and 1018 is a NAND gate and an inverter which are connected in series. A signal of the node C 1 is inputted through input terminals of the conversion circuits 1017 and 1018 . In FIG. 10 , the whole delay time is taken from the node C 1 to the node C 2 . Here, the nodes C 1 and C 2 are identical to the nodes C 1 and C 2 shown in FIG. 8 . And, a signal of the node C 1 is inputted through an input terminal of NAND gate NAND 103 . As stated above in connection with FIG. 7 , the selection signals sel_ 3 z , sel_ 2 z , sel_ 1 z , and sel_ 0 z , which control turn-on/off operations of the switching units, are made from logical combinations with address signals. As can be seen from FIGS. 7 and 10 , when the address signals add_ 0 and add_ 1 are all low levels, the selection signal sel_ 3 z is enabled in low level. When the address signals add_ 0 and add_ 1 are respectively low and high levels, the selection signal sel_ 2 z is enabled in low level. When the address signals add_ 0 and add_ 1 are respectively high and low levels, the selection signal sel_ 1 z is enabled in low level. When the address signals add_ 0 and add_ 1 are all high levels, the selection signal sel_ 0 z is enabled in low level. In FIG. 10 , NAND gates NAND 101 and NAND 102 receive the selection signals sel_ 2 z and sel_ 3 z . The switching unit 1011 is turned on/off by an output signal of the NAND gate NAND 101 . The switching unit 1014 is turned on/off by an output signal of the NAND gate NAND 102 . The switching unit 1012 is turned on/off by the selection signal sel_ 1 z . The switching unit 1013 is turned on/off by the selection signal sel_ 0 z . The switching unit 1015 is turned on/off by the selection signal sel_ 3 z. In operation, when the selection signals sel_ 2 z and sel_ 3 z are all low levels, an output signal of the NAND gate NAND 101 receiving the selection signals sel_ 2 z and sel_ 3 z is high level. Thus, the switching units 1011 and 1014 are turned on. As a result, a signal receiver through the node C 1 passes through the delay units 1000 and 1001 , the conversion circuit 1017 , the delay unit 1001 , the switching unit 1011 , the delay unit 1001 , the conversion circuit 1018 , and the switching unit 1014 , in sequence. Here, if the selection signal sel_ 3 z is low level, the signal passing through the switching unit 1014 is transferred to the node C 2 by way of the NAND gate NAND 103 and inverter INV 101 after passing through the delay unit 1004 and the switching unit 1015 . Otherwise, if the selection signal sel_ 3 z is high level, the signal passing through the switching unit 1014 is transferred to the node C 2 by way of the switching unit 1015 , the NAND gate NAND 103 , and inverter INV 101 . Therefore, when the selection signals sel_ 2 z and sel_ 3 z are all low levels, the signal passing through the switching unit 1014 is transferred to the node C 2 by way of the NAND gate NAND 103 and the inverter INV 101 after passing through the delay unit 1004 . In operation, when the selection signal sel_ 1 z is low level, the switching unit 1012 is turned on. Thus, a signal input through the node C 1 passes through the delay units 1000 and 1001 , the conversion circuit 1017 , the delay unit 1002 , and the switching unit 1012 , in sequence. If the selection signal sel_ 3 z is low level, the signal passing through the switching unit 1012 is transferred to the node C 2 by way of the NAND gate NAND 103 and the inverter INV 101 after passing through the delay unit 1004 and the switching unit 1015 . Otherwise, if the selection signal sel_ 3 z is high level, the signal passing through the switching unit 1012 is transferred to the node C 2 by way of the switching unit 1015 , the NAND gate NAND 103 , and the inverter INV 101 . In operation, when the selection signal sel_ 0 z is low level, the switching unit 1013 is turned on. Thus, a signal input through the node C 1 passes through the delay unit 1000 and the switching unit 1013 , in sequence. If the selection signal sel_ 3 z is low level, the signal passing through the switching unit 1013 is transferred to the node C 2 by way of the NAND gate NAND 103 and inverter INV 101 after passing through the delay unit 1004 and the switching unit 1015 . Otherwise, if the selection signal sel_ 3 z is high level, the signal passing through the switching unit 1013 is transferred to the node C 2 by way of the switching unit 1015 , the NAND gate NAND 103 , and inverter INV 101 . As illustrated in FIG. 10 , in the test mode, it is possible to adjust a delay time taken from the node C 1 to the node C 2 by using the selection signals generated from logical combinations with the external address signals add_ 0 and add_ 1 . For example, when the test mode signal tmz_ 1 is high level, the delay path between the nodes C 1 and C 2 is inhibited. But, if the test mode signal tmz_ 1 is low level, the delay path between the nodes C 1 and C 2 is open and adjustable by means of the selection signals. FIG. 11 is an operational timing diagram of the conventional circuit shown in FIG. 2A . As can be seen from FIG. 11 , the conventional circuit is just capable of adjusting only a pulse width of the output signal rdwtstbzp 13 in accordance with a logical level of a signal tmz_clkpulsez. FIG. 12 is a waveform diagram illustrating a pulse width variation of the read/write strobe pulse signal rdwtstbzp 13 output from the conventional circuit of FIG. 2A when an operation voltage vdd of a memory device varies. As illustrated in FIG. 12 , the conventional circuit has a problem that a pulse width of the read/write strobe pulse signal rdwtstbzp 13 decreases when the operation voltage rises. FIG. 13 is a waveform diagram of signals used in the circuit of the present invention, specifically an exemplary waveform diagram of signals used in the circuit of FIG. 5 . FIG. 13 illustrates waveforms of the clock signal clk_in, the frequency dividing signal dlic 4 _ref, the phase-inversed frequency dividing signal dlic 4 , the delay signals dlic 4 d 1 and dlic 4 d 2 , the pulse signal amp, the flag signals flag_ 1 and flag_ 2 , and the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z. In FIG. 13 , the cycle period of the frequency dividing signal dlic 4 _ref is four times of tCLK. And, the low level term of the frequency dividing signal dlic 4 _ref is identical to that of tCLK. The phase-inversed frequency dividing signal dlic 4 is opposite to the frequency dividing signal dlic 4 _ref in phase and generated with a predetermined delay time. The phase-inversed frequency signal dlic 4 is outputted as the delay signal dlic 4 d 1 after passing through the delay unit having the delay time of delay_A. The phase-inversed frequency dividing signal dlic 4 is also outputted as the delay signal dlic 4 d 2 after passing through the delay unit having the delay time delay_B. At this case, the phase-inversed frequency dividing signal dlic 4 and the delay signals dlic 4 d 1 and dlic 4 d 2 have high level terms as same as that of tCLK. In FIG. 13 , it is established of delay_A<delay_B. Hereinafter, it will be described in detail about the signal waveform diagram of FIG. 8 with reference to the circuit of FIG. 4 . In the condition of that the frequency dividing signal dlic 4 -ref, the delay signal dlic 4 d 1 and the pulse signal cmp are all high levels, initial values of the nodes e, f, g, and h in FIG. 4 are all high levels. In this condition, if the delay signal dlic 4 d 1 changes to high level earlier than the frequency dividing signal dlic 4 _ref, the node e transits to low level. Next, when the pulse signal cmp transits to high level, the node h transits to low level. Thus, the flag signal flag_ 1 becomes high level. On the other hand, if the frequency dividing signal dlic 4 _ref changes to high level earlier than the delay signal dlic 4 d 1 , the node f transits to low level. Next, when the pulse signal cmp transits to high level, the node g transits to low level. Thus, the flag signal flag_ 1 becomes low level. As described above, it is important in FIG. 5 that it determines a logical level of the flag signal flag_ 1 in accordance with which one of the two signals dlic 4 _ref and dlic 4 d 1 to be compared transits to high level earlier before the pulse signal cmp goes to high level. A procedure of generating the flag signal flag_ 2 is substantially identical to that of the flag signal flag_ 1 , so will be omitted about it. On the other side, the delay rates represented by delay_A and delay_B are provided to detect a frequency range of the clock signal clk_in. For instance, in FIG. 13 , the fact that a rising edge of the delay signal dlic 4 d 1 is earlier than that of the frequency dividing signal dlic 4 _ref means that the delay rate of delay_A is smaller than the cycle period of the clock signal clk_in. As such, the fact that a rising edge of the delay signal dlic 4 d 2 is later than that of the frequency dividing signal dlic 4 _ref means that the delay rate of delay_B is larger than the cycle period of the clock signal clk_in. Therefore, such cases form the relation of delay_A<tCK<delay_B. FIG. 13 illustrates waveform features satisfying the conditional relation. FIG. 14 is a diagram illustrating a procedure of changing logical levels of the flag signals flag_ 1 and flag_ 2 in accordance with a frequency of the clock signal clk_in. For sections A, B, and C of FIG. 14 , it can be seen of delay_A<delay_B. When tCK<delay_A as like the section A of FIG. 14 , the flag signals flag_ 1 and flag_ 2 are all low levels. When delay_A<tCK<delay_B as like the section B of FIG. 14 , the flag signal flag_ 1 is high level while flag_ 2 is low level. When tCK>delay_B as like the section C of FIG. 14 , the flag signals flag_ 1 and flag_ 2 are all high levels. As such, it can be understood that the flag signals include the information for the operating frequency of the memory device. With those flag signals, logical levels of the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z are determined to select the delay path in the circuit shown in FIG. 8 . FIG. 15 is a diagram illustrating a waveform of the output signal rdwtstbzp 13 when paths C 1 and C 2 shown in FIG. 10 are used therein. As aforementioned, the circuit of FIG. 10 is to be used in the test mode that begins in response to the test mode signal tmz_ 1 shown in FIG. 8 . In other words, the delay time is further adjustable by applying the address signals during the test mode. The selection signals sel_ 3 z , sel_ 2 z , sel_ 1 z , and sel_ 0 z are generated from logical combinations with the address signals as aforementioned with reference to FIG. 7 . Section A of FIG. 15 illustrates waveforms of the input signal extyp 8 and the output signal rdwtstbzp 13 when the operating frequency detection signals dec_ 2 z and dec_ 1 z are all high levels while the operating frequency detection signal dec_ 0 z is low level. Section B of FIG. 15 illustrates waveforms of the input signal extyp 8 and the output signal rdwtstbzp 13 when the operating frequency detection signals dec_ 0 z and dec_ 2 z are all high levels while the operating frequency detection signal dec_ 1 z is low level. Section C of FIG. 15 illustrates waveforms of the input signal extyp 8 and the output signal rdwtstbzp 13 when the operating frequency detection signals dec_ 0 z and dec_ 1 z are all high levels while the operating frequency detection signal dec_ 2 z is low level. As can be seen from the sections A, B, and C in FIG. 15 , a pulse width of the output signal rdwtstbzp 13 is variable in accordance with logical levels of the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z which contain the information for the operating frequency of the memory device. Further, the pulse width of the output signal rdwtstbzp 13 is also variable in accordance with logical levels of the selection signals sel_ 0 z , sel_ 1 z , sel_ 2 z , and sel_ 3 z when the logical levels of the operating frequency detection signals dec_ 0 z , dec_ 1 z , and dec_ 2 z are equal from each other (e.g, in the section A). FIG. 16 is a waveform diagram illustrating a variation of the output signal rdwtstbzp 13 in accordance with a variation of the operation voltage. As illustrated in FIG. 16 , it can be seen that the pulse width of the output signal rdwtstbzp 13 is variable in accordance with logical levels of the voltage selection signals vsel_ 2 z , vsel_ 1 z , and vsel_ 0 z . In the conventional circuit as shown in FIG. 12 , a pulse width of the output signal rdwtstbzp 13 decreases along an increase of the operation voltage vdd. However, the present invention is configured, as shown in FIG. 16 , with that the pulse width of the output signal rdwtstbzp 13 does not decrease even along an increase of the operation voltage vdd. Such a result of simulation, as illustrated in FIG. 16 , is just provided for notifying an improvement by the present invention over the conventional art. It is also possible to enable the pulse width of the output signal rdwtstbzp 13 to be stable by properly selecting the delay path by means of the voltage selection signals even when the operation voltage varies. As apparent from the above description, the present invention provides a method and circuit for controlling a pulse width of the read/write strobe pulse signal rdwtstbzp 13 to control an operation of an Yi pulse signal by detecting an operating frequency of the memory device. By utilizing the method and circuit according to the present invention, the pulse width of the read/write strobe pulse signal rdwtstbzp 13 is optimally adjusted to control an enabling period of the Yi pulse signal. With the method and circuit of the present invention, as it is possible to automatically adjust a pulse width of the Yi signal, there is no need of an FIB process for tuning delay times whenever an operating frequency varies. Therefore, it downs costs and times relative to the conventional case. Moreover, the present invention offers a reliable operation by reducing a pulse width variation of the read/write strobe pulse signal when an operation voltage varies. In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Provided is a circuit for controlling a data bus connecting a bitline sense amplifier to a data sense amplifier in accordance with a variation of an operating frequency of a memory device, being comprised of a pulse width adjusting circuit for varying a pulse width of an input signal in accordance with the operating frequency of the memory device after receiving the input signal, a signal transmission circuit for buffing a signal outputted from the pulse width adjusting circuit, and an output circuit for outputting a first signal to control the data bus in response to a signal outputted from the signal transmission circuit.

CROSS-REFERENCE TO RELATED APPLICATION(S) [0001] This application claims priority to European Patent Application 13178834.1 which was filed Jul. 31, 2013 and is incorporated herein by reference in its entirety. TECHNICAL FIELD [0002] The present disclosure pertains to the field of orthopaedic surgery and relates in particular to the application of an external fixator to a long bone by means of unicortical pins. [0003] The disclosure also relates to an anchoring group comprising the aforementioned pin-locking device articulated to a locking clamp of an external fixator bar, as well as to an external fixator comprising said anchoring group. BACKGROUND [0004] External fixators are widely used for the treatment of bone fractures or for joining together two or more bone fragments. Known fixators comprise bone screws which are inserted in the bones and use external devices such as fixation clamps, fixation bars, rings, etc., that allow the creation of a rigid structure able to hold together the bone fragments in the desired position until completely healed. [0005] These external fixators have the advantage of ensuring strength and stability owing, among other things, to the use of bone screws which penetrate into the bones at a sufficient depth; in particular, these screws pass through the bone cortex in two points so as to provide a flexurally resistant fastening. [0006] However, the use of bi-cortical screws may be excessively invasive for patients in critical conditions, who for example have multiple fractures along with, in some case, extensive wounds and/or contusions. In particular the time devoted to checking the tip which emerges from the second cortex may be critical. [0007] Also, with particular reference to the reduction of fractures in long bones, the aforementioned bi-cortical screws pass through the medullary cavity, which makes it impossible to simultaneously insert a medullary nail, which is particularly suitable for the treatment of certain types of trauma. [0008] Moreover, the surgical implant of a definitive fixator of the aforementioned type requires time and suitable facilities and is not always compatible with the unforeseen circumstances where rapid intervention is required; for example, it is relatively difficult to perform the implant of such an external fixator in the context of a field hospital or in any case under environmental conditions where sterility is not guaranteed and where the fracture must be treated as a matter of emergency. [0009] In order to meet these specific needs, external fixators of a provisional nature have been developed that, in addition to having a structure which is generally slimmer and lighter, use unicortical screws or unicortical pins for the attachment to the bone, i.e. that have been designed to be screwed in superficially so that they are attached to a single bone cortex only. [0010] The unicortical pin undoubtedly represents a less invasive fixation system than conventional bone screws; moreover, owing to its limited penetration, the pin does not reach the medullary cavity of the bone, thus avoiding the risk of unwanted infections. [0011] On the other hand, however, owing to its limited stability—due mainly to the fact that it passes through one cortex only, which means that flexural strength is limited—this type of screw is not widely used in external fixation applications. [0012] It would instead be desirable to be able to use an external fixator, which has the advantages of stability and strength typical of provisional fixation systems, and to combine it with the advantages of ease of application, lightness and limited invasiveness that are instead typical of systems that use unicortical pins. [0013] The technical problem forming the basis of the present disclosure is therefore to devise a locking device for unicortical pins to be associated with external fixators, which is able to create a structure sufficiently rigid for it to withstand the external loads acting on it, so as to allow the formation of external fixators that are extremely flexible, but that at the same time have that degree of structural rigidity that typically distinguishes external fixation systems. [0014] The device should have an optimum performance, under traction and compression, of the tip in the cortex of the bone and should eliminate, as far as possible, the flexural stresses acting on the shank of the single screw. SUMMARY OF THE DISCLOSURE [0015] In some embodiments of the present disclosure, the aforementioned technical problem may be solved by using a locking device for unicortical pins. [0016] In some embodiments of the present disclosure, application of an external fixator to a patient's long bone by means of the unicortical pins is provided for. [0017] The application method described above may make it possible to create fixation systems with exceptional stability, despite its use of unicortical pins only. [0018] Further features and advantages will become clearer from the detailed description provided below of some preferred, but not exclusive, embodiments of the present disclosure, with reference to the attached figures provided by way of non-limiting example. BRIEF DESCRIPTION OF THE DRAWINGS [0019] FIGS. 1-4 show different perspective views of an external fixator associated with the long bone of a patient using the method according to the present disclosure, where the locking devices of the distal and proximal anchoring groups are mounted in different configurations; [0020] FIG. 5 shows a front view of an anchoring group associated with the bone of a patient; [0021] FIG. 6 shows a perspective view of the anchoring group of FIG. 5 ; [0022] FIG. 7 and FIG. 8 show two perspective views of an anchoring group, in which mounting of the locking devices in two different configurations is shown; [0023] FIG. 9 shows a perspective view of a connecting body of the anchoring group; [0024] FIG. 10 shows a front view of the connecting body of FIG. 9 ; [0025] FIG. 11 shows a further perspective view of the connecting body of FIG. 9 ; [0026] FIG. 12 shows a perspective view of the locking clamp of the anchoring group; [0027] FIG. 13 shows a perspective view of the main body of a locking device; [0028] FIG. 14 shows another perspective view of the main body of FIG. 13 ; [0029] FIG. 15 shows a perspective view of the pressing body of the locking device; [0030] FIG. 16 shows a perspective view of the locking means of the locking device; [0031] FIG. 17 shows a perspective view of a deformable sphere forming part of the locking means shown in FIG. 16 ; [0032] FIG. 18 shows a perspective view of a bar/pin clamp which can be associated with the connection bar of the external fixator. DETAILED DESCRIPTION [0033] With reference to the attached figures, and in particular to FIGS. 1-4 , the reference number 1 denotes overall an external fixator applied according to the method of the present disclosure, to a long bone of a patient using only unicortical pins or screws 100 . [0034] The external fixator may comprise in particular a bar 2 , known per se, which may be fixed to the bone by means of two anchoring groups 20 which may be respectively arranged in a distal position and proximal position. [0035] Each of the anchoring groups 20 may comprise two locking devices 10 , each of which may be designed to be locked into position by two unicortical pins 100 which may be implanted into the bone of a patient. The two locking devices 10 may extend laterally, in the manner of wings, from a central connecting body 11 of the anchoring group which may also support a locking clamp 3 designed to grip the bar of the external fixator 1 . [0036] In some embodiments, the locking devices 10 may be made as modular elements which may be mounted separately on the connecting body 11 ; nevertheless, alternative embodiments may be possible in which the entire anchoring group 20 may be formed as one piece, while retaining the particularly advantageous form and functional characteristics described below. [0037] The single locking device 10 may have a substantially L-shaped main body. More specifically, the single locking device 10 may have a pin-locking arm 101 and a connection base 102 which may together form an elbow. An angle α between the direction of extension of the arm x and the direction of extension of the base y, shown in FIG. 13 , is preferably an angle that is substantially greater than a right angle, namely between 120° and 150°. It may be noted that the pin-locking arm 101 and the connection base 102 may extend along a same plane of orientation P 1 of the locking device 10 . [0038] The pin-locking arm 101 may have at its two opposite ends two seats 101 a , 101 b which may be designed to lock a corresponding number of unicortical pins 100 . This locking action may be performed by the locking means 103 described below. [0039] The locking means 103 may comprise, in particular, two deformable spheres 103 a , 103 b , one of which is shown separately in FIG. 17 , which may be provided with a diametral insertion channel 1031 that defines the actual seat 101 a , 101 b for the unicortical pins 100 . The deformable spheres may have a plurality of incisions that may cross the sphere in a planar manner passing through the insertion channel 1031 ; the incisions may lead alternately into one or the other of two opposite openings of the insertion channel 1031 . Because of the incisions, the sphere may become deformed when it is compressed along the axis of the insertion channel. Thus, the insertion channel 1031 may be constricted locally, by which the unicortical pin 100 housed therein may be locked. [0040] The aforementioned deformable spheres 103 may be housed between an elongated impression 101 c , formed along the upper surface of the pin-locking arm 101 , and a pressure plate 103 a shaped to counter the opposite impression 101 c . In particular, both the pressure plate 103 c and the impression 101 c may have smooth through-holes 1011 at their ends; the two deformable spheres 103 may be locked between two smooth through-holes 1011 situated opposite each other. The insertion channel 1031 of the spheres 103 may be accessible via the smooth through-holes 1011 so as to allow the introduction of the unicortical pin 100 . [0041] A pressure plate 103 c may be connected to the impression via tightening means 103 d which may take the form of a screw. The shank of the screw may be inserted into a central through-hole 1010 a of the pressure plate and then into an opposite central hole 1010 b formed in the bottom of the impression 101 c , on the outside of which it may engage with a nut. Resilient setting means 103 e may also be arranged between the pressure plate 103 c and the impression 101 c , which may be formed in particular by two helical springs that are compressed between the two elements and may be retained inside oppositely arranged depressions 1012 of the impression 101 c and the pressure plate 103 c. [0042] The springs, which may be arranged in intermediate positions between the deformable spheres 103 and the screw, may oppose the tightening action of the latter. Such arrangement may allow the deformable spheres 103 to be deformed and the unicortical pins 100 to be locked inside them. [0043] It should be noted that when the compression plate is not clamped, the deformable spheres 103 may be rotatable inside their seat, such that the surgeon may modify as required the orientation of the inserted unicortical pins 100 . Tightening the head of the screw 103 d eliminates this degree of rotational freedom. [0044] The deformable spheres 103 may have, in one of the openings of the insertion channel 1031 , a raised cylindrical edge 1032 which, once inserted inside the smooth through-hole 1011 , may limit the rotational movement of the element, while may allow access to the insertion channel 1031 . [0045] In some embodiments, the deformable spheres 103 may allow the direction of the unicortical pins 100 to be varied with respect to the axis perpendicular to the plane of orientation P 1 by about 20°. [0046] The connection base 102 has at its free end a fastening point 102 a suitable for connection to the connecting body 11 . [0047] Moreover, the connecting body 11 may have, on both sides, two alternative fastening seats 110 a , 110 b for the connection of the fastening point 102 a. [0048] The fastening point 102 of the locking device 10 may present an enlarged portion through which a fastening hole 102 c may passes and, on the opposite side of the enlarged portion, a projecting tenon 102 b ; on the other hand, the fastening seats 110 a , 110 b may present a depression or mortise 110 c shaped to match the tenon 102 b , and a fastening hole 110 d formed in the bottom of the mortise 110 c. [0049] When the tenon 102 b is correctly inserted into the mortise 110 c of one of the fastening seats 110 a , 110 b , the two fastening holes 102 c , 110 d may be aligned so that a threaded connection element 104 that fixes the locking device 10 to the connecting body 11 may pass through them. [0050] The connecting body 11 may have a structure that is substantially symmetrical with respect to its median plane M. Said connecting body 11 may have a cusp portion 111 at the front with opposite inclined surfaces that are symmetrical with respect to said median plane M, and at the rear a hinge portion 112 , which will be described below. [0051] Both the inclined surfaces of the cusp portion 111 have a top section with an inclination greater than the horizontal and a bottom section with a smaller inclination. The first fastening seat 110 a may be formed on the first section and the second fastening seat 110 b may be formed on the second section. Thus, depending on whether the locking device 10 may be connected to the first fastening seat 110 a or to the second fastening seat 110 b , two different inclinations of the plane of orientation P 1 with respect to the median-plane M may be obtained. Consequently, also the inclination of the preferential plane of orientation P 2 of the unicortical pins 100 may be modified, i.e. the plane on which the pins lie, with due allowance for any adjustments performed by means of the deformable spheres 103 a , 103 b. [0052] The inclination imparted to the fastening seats 110 a , 110 b in the present disclsoure may be such that, by associating both locking devices 10 with the respective first seat 110 a , an angle between the two planes of orientation P 1 may be created that is smaller than a right angle; on the other hand, by associating the locking devices 10 with the second seat 110 b , an angle between the two planes of orientation P 1 may be obtained that is greater than a right angle. The first configuration may be particularly suitable for small-size bones (e.g., tibial mounting), while the second configuration may be suitable for large-size limbs (e.g., femoral mounting). [0053] The hinge portion 112 of the connecting body 11 may allow for articulation, around an axis of rotation r 1 perpendicular to the median plane M, of a locking clamp 3 . [0054] The hinge portion 112 may define in particular a cylindrical seat 1120 intended to define interiorly an articulation hinge 33 of the locking clamp 3 . A threaded element, with a shank which defines the pin 33 a of the hinge 33 and a head which acts as a cover for the cylindrical seat 1120 , is in fact screwed laterally into the cylindrical seat 1120 . A shank 30 of the locking clamp 3 , which may comprise an eyelet end 30 a , which may embrace the aforementioned pin 33 a , may also be inserted, via an upper groove 1121 , inside the cylindrical seat 1120 . [0055] Outside of the cylindrical seat, the shank 30 may pass through, in succession, an intermediate element 34 , slidably movable along an outer cylindrical surface of the hinge portion 112 , and two jaws 32 designed to grip in a known manner the bar 2 of the external fixator. A splined coupling IM may be formed between the bottom jaw 32 and the intermediate element 34 that ensures restriction of rotation when the two parts are clamped against each other. The free end of the shank 30 may be threaded and a lock nut 31 may be screwed onto it. [0056] When the abovementioned group is not clamped, adjustments both around the axis of rotation r 1 of the hinge and around the axis r 2 of the shank 30 may be possible. Tightening the lock nut 31 may cause the entire group to be pressed together and performs the triple function of locking the bar 2 between the jaws of the clamp 3 and blocking the two abovementioned rotational axes. In particular, the axis of rotation r 1 may be blocked by the friction between the intermediate element 34 and the outer cylindrical surface of the hinge portion 112 , and the axis of rotation r 2 may be blocked by the locking action of the splined coupling IM. [0057] Having described individually the single elements which make up the anchoring groups 20 of the external fixator 1 , description is now provided below for the different possibilities of assembling them in order to obtain different configurations of the said fixator. [0058] First of all, the locking devices 10 may be constructed in two configurations which may be a mirror image of each other, namely a configuration oriented to the right of the connection base 102 and a configuration oriented to the left of the connection base 102 . [0059] The external fixator 1 , which by nature is modular, may comprise both right-hand and left-hand locking devices 10 which may be used alternatively by the surgeon in the field depending on the actual operating requirements. [0060] Thus, depending on the locking devices chosen, each anchoring group 20 may be mounted in three different configurations: a U configuration, in which the two locking devices 10 may both be oriented in the same direction, away from the locking clamp 3 of the anchoring group 20 ; an M configuration, in which the two locking devices 10 may both be oriented in the direction of the locking clamp 3 of the anchoring group 20 ; and an S configuration, in which the locking devices 10 are oriented in opposite directions. [0061] With reference to the enclosed figures: FIG. 1 shows an external fixator 1 in which both anchoring groups 20 have a U configuration; in FIG. 2 both anchoring groups 20 have an S configuration; in FIGS. 3 and 4 the proximal mounting group 20 has a U configuration and the distal group has an M configuration, i.e. in a position where the pin-locking arms 101 point in a distal direction and proximal direction, respectively. [0062] The various configurations described above may be used alternatively by the surgeon, depending on the specific operating requirements and the morphology of the fractured bone. In particular, with the S configuration two unicortical pins 100 may be arranged in the vicinity of the fracture site, thereby increasing stability. It is a known fact that the relative spacing of the screws may improve the stability of an external fixator 1 . [0063] In the case where additional stability is required, further unicortical pins 100 may be added, being directly fixed to the bar 2 by means of one or more bar/pin clamps 4 of the type known in the art. [0064] In some embodiments, methods for applying an external fixator 1 are provided. Methods may comprise the following steps: [0000] preparing the first anchoring group 20 , for example the distal anchoring group of the type described above, where necessary mounting it in the configuration most suitable for the intervention according to the modes described above; inserting unicortical pins 100 in at least three of the seats 101 a , 101 b (but preferably all four of them) of the two pin-locking devices 101 of the anchoring group 20 ; fixing the unicortical pins 100 to the long bone of the patient, rotating them by means of a special instrument, using the seats 101 a , 101 b as boring guides; locking said unicortical pins 100 inside the seats 101 a , 101 b using the special locking means 103 described above. [0065] It should be noted that before fixing the unicortical pins 100 to the bone, they may be oriented by rotating the deformable sphere 103 a , 103 b in which they are inserted and then locking them in position by tightening the aforementioned locking means 103 . [0066] It should in particular be noted that the unicortical pins may have a self-tapping tip so that it may be sufficient to rotate them, associating their head with a drilling device in order to create the fixation hole in the patient's bone, whereby said hole may only penetrate the first cortex. [0067] The steps described above may then be repeated in order to fix a second anchoring group 20 , for example the proximal anchoring group; following which, by performing the adjustments along the axes r 1 and r 2 of the locking clamps 3 of the two anchoring groups 20 , they are aligned and connected to the bar 2 . [0068] As previously mentioned, in order to improve the stability of the external fixator, further unicortical pins 100 , preferably two in number, may be used, associating them directly to the bar 2 by means of bar/pin clamps 4 . [0069] It should be noted that, during mounting of the anchoring groups, owing to the L-shaped form of the locking device 10 , X-ray access to the bone site concerned in the intervention is never obstructed by the structure of the anchoring groups, so that the various parts which make up the group need not necessarily be made of radiotransparent material. [0070] It should also be noted that the non-invasive form of the anchoring group 20 , in particular in its U configuration with the opening directed towards the bone end, may allow for easy access of an instrument for reaming the long bone of the patient and subsequently inserting an intramedullary nail, even when the anchoring group is positioned at the point where the nail end is inserted. [0071] One of ordinary skill in the art, in order to satisfy specific requirements which may arise, may make numerous modifications and variations to the devices described above, all of which are however contained within the scope of protection of the disclosure, as defined by the following claims.

The present disclosure relates to an anchoring group for an external fixator, that comprises a connecting body designed to be coupled to a bar of an external fixator. A locking device is connected to the connecting body at a fastening point thereof and comprises a pin locking arm provided with two seats suitable for locking a corresponding number of uni-cortical pins. A connection base is intended to be coupled to a connecting body of the anchoring group. An additional member, also associated with the connecting body, comprises at least one auxiliary seat, not aligned with the seats of the locking device, for locking an additional uni-cortical pin. In an additional embodiment, the connection base of the locking device extends in an angled relationship with respect to the pin locking arm and away from both the seats. The connection base has a point for fastening to the connecting body which is not aligned with said seats.

BACKGROUND OF THE INVENTION Open reel type magnetic tape drive, such as used in computers and data processing equipment, are usually installed in a generally upright position, the reels and the head assembly being exposed for access. The tape supply reel is normally secured on one driven hub and the tape is threaded through the head assembly and attached to the take-up reel. Since the reels and head assembly are exposed, their design is usually made attractive in appearance by means of trim, covers and other cosmetic features, which add to the cost of the apparatus. In many installations the mechanism is protected by doors, which are often transparent, leaving the mechanism exposed and thus subject to esthetic treatment. The upright tape drive units require a considerable amount of space and limit the packaging arrangement in many instances. It would be advantageous to have a tape drive unit which would fit into a minimum of space, be easy to load and unload and be concealed in use so as not to require cosmetic trim. SUMMARY OF THE INVENTION The tape drive unit described herein is constructed horizontally to fit into a drawer, or other low profile enclosure. The only access is through a front slot, in which the edge portions of a supply hub and a take-up reel, which grips the tape by vacuum until the first turn or two are wound up. When the starting sequence is initiated, the take-up reel is swung to the rear of the unit on an arm, which action pulls the tape across a guide and head array, so eliminating the need for threading the tape. At the same time the supply hub is retracted and the supply reel is secured on the hub by cam actuated clamps. The supply hub and take-up reel have individual drive motors, but the arm movement and the supply hub retraction are accomplished by a single actuating motor. All of the actuating mechanism is fully enclosed, but is readily accessible for servicing by opening the drawer. The primary object of this invention, therefore, is to provide a new and improved magnetic tape drive unit. Another object of this invention is to provide a tape drive unit which is installed horizontally in a drawer and is loaded and unloaded through a front slot. Another object of this invention is to provide a tape drive unit which is concealed in use and requires a minimum of access for operation. A further object of this invention is to provide a tape drive unit which is adaptable to standard tape reels, read/write means and control operations. Other objects and advantages will be apparent in the following detailed description, taken in conjunction with the accompanying drawings, in which; FIG. 1 is a pictorial view of a typical desk with the tape drive unit installed in a drawer. FIG. 2 is a front elevation view of the tape drive unit. FIG. 3 is a top plan view of the front portion of the tape drive unit, showing the manual tape loading operation. FIG. 4 is an enlarged sectional view taken along line 4--4 of FIG. 2. FIG. 5 is a sectional view taken along line 5--5 of FIG. 4. FIG. 6 is an enlarged front elevation view of the drive unit with the front cover removed. FIG. 7 is an enlarged sectional view taken along line 7--7 of FIG. 4. FIG. 8 is a sectional view taken along line 8--8 of FIG. 7. FIG. 9 is a sectional view taken along line 9--9 of FIG. 6. FIG. 10 is a view taken along line 10--10 of FIG. 9. FIG. 11 is a sectional view taken along line 11--11 of FIG. 9. FIG. 12 is an enlarged sectional view taken along line 12--12 of FIG. 4. FIG. 13 is a top plane view of the structure of FIG. 12, with portions cut away. FIG. 14 is a sectional view taken along line 14--14 of FIG. 12. FIGS. 15-18 illustrate diagramatically the loading and unloading sequence of the mechanism. DESCRIPTION OF THE PREFERRED EMBODIMENT The tape drive unit 10 is contained in a housing 12 constructed as a drawer, which can be installed in a desk 14 with any conventional arrangement of slides or guides, not shown. The housing has a front panel 16 in which the usual controls 18 are mounted, the upper portion of the front panel having a horizontal access slot 20 through which the tape is loaded and unloaded. Since the front panel is the only portion of the unit normally visible, it alone may be made attractive in appearance as desired. The drawer need not be opened except for servicing the mechanism when needed. The specific structure of the housing is not critical, but in the arrangement illustrated all of the mechanism is mounted on a rigid base plate 22, secured in the housing just below the level of slot 20. Housing 12 may have a removable top cover 24 for access to the reels and head assembly, which are on top of base plate 22, all of the actuating mechanism being below the base plate clear of the tape path. In the front right hand portion of base plate 22 is a rearwardly extending opening 26, along the sides of which are rails 28 fixed below the base plate. A mounting plate 30 is slidably mounted between rails 28 to move from front to rear. Suitable bearings could be used between rails 28 and plate 30 to reduce friction. Secured below mounting plate 30 is a motor 32 having an upwardly extending drive shaft 34, on which is a supply hub 36. The supply hub 36 has a raised central boss 38 to fit the opening 40 of a tape supply reel 42 and supports the reel parallel to and above the base plate 22. To the rear of opening 26 is a post 44 projecting below base plate 22 and pivotally mounted on the post is an arm 46. On the outer end of arm 46 is a take-up motor 48 coupled by a belt drive 50 to a take-up reel 52, which is rotatable on a support shaft 54 mounted in a bracket 56 on the arm. Take-up reel 52 projects above base plate 22 through an arcuate slot 58 having its center of radius at post 44. Slot 58 extends from near the front to the rear portion of the base plate. In the forward position of arm 46, the take-up reel 52 is at the front of the unit alongside supply hub 36 and accessible through slot 20. In the rear position of arm 46, the take-up reel 52 is positioned above a raised circular platform 60 on the rear portion of the base plate, as indicated in broken line in FIG. 4. The arm 46 is operated by an actuating motor 62 mounted under base plate 22 adjacent post 44, the actuating motor having a drive shaft 64 carrying a crank 66. A link 68 couples the crank 66 to a lug 70 on arm 46. As illustrated in FIG. 9, rotation of shaft 64 pulls arm 46 from the forward, full line position to the rear, broken line position. The actuating motor 62, shown in FIGS. 4 and 11, is omitted from FIG. 9 for clarity. The supply hub 36 is retracted or pulled rearwardly as arm 46 moves to the rear position and is moved forward when the arm swings forward. This is accomplished by a tie bar 72 pivotally connected between a lug 74 on arm 46 and a lug 76 on the rear edge of mounting plate 30. The two positions of this linkage are also indicated in FIG. 9. Mounted on top of base plate 22 along the inner edge of slot 58 is a tape utilization head assembly 78, over which the tape passes. The head assembly comprises, from the front, a tachometer 80, which is coupled to a suitable readout to show the amount of tape advanced, a guide roller 82, an optical sensor 84 to detect end of tape markings, a read/write head 86 and a guide roller 88. As described later, the tape 89 is stretched across the head assembly 78 when the arm 46 swings to the rear. To maintain tension in the tape, a tension roller 90 is brought into engagement with the tape after it is extended over the head assembly. Since the tension roller must be clear of the tape path during loading and unloading it is retracted and extended by linkage coupled to arm 46. As illustrated in FIGS. 7 and 8, the tension roller 90 is rotatably mounted on a post 92 at the end of a support arm 94, which is pivoted on a horizontal pin 96 in a bracket 98. The bracket 98 is rotatable on a post 100 projecting vertically downward from base plate 22, so that the bracket and support arm can swing horizontally and the support arm can pivot vertically in the bracket. A lifting spring 102 between bracket 98 and the support arm 94 biases the support arm upwardly. The tension roller 90 and its supporting post 92 project above base plate 22 through an arcuate slot 104, centered on post 100 and can move from a forward retracted position indicated in full line in FIG. 4, to a rearward tension position indicated in broken line. The tension roller is retracted below the tape path in the forward position by a roller cam 106 mounted on base plate 22 to engage and depress support arm 94, as in FIG. 7. Since the tension roller must not be raised until after the tape has passed and must be retracted before the tape is unloaded, a lost motion linkage is used to couple the tension roller to arm 46. A generally triangular link plate 108 is pivotally mounted on post 100 below bracket 98 and has upwardly projecting fingers 110 and 112 at opposite corners. The fingers are spaced apart to allow the link plate to have a limited range of rotation between engagements of the fingers with opposite sides of bracket 98. A connecting rod 114 connects the link plate 108 to arm 46. In the forward position of arm 46, finger 110 holds the bracket 98 in place with support arm 94 depressed under roller cam 106, as in the full line position in FIGS. 7 and 8. When arm 46 swings rearwardly, connecting rod 114 pulls link plate 108 back, but there is no movement of bracket 98. When the arm 46 has travelled far enough to extend the tape beyond the start of the head assembly, finger 112 engages bracket rearwardly, as in the broken line position. Support arm 94 rides off roller cam 106 and spring 102 lifts the support arm and tension roller 90 up into the tape path. Continued motion of arm 46 pulls the tension roller into engagement with the tape 89 and pulls an offset loop 116 into the tape, as in FIG. 4. A torsion spring 118 installed between link plate 108 and bracket 98 provides the tensioning force. Forward movement of arm 46 will, of course, reverse the action by swinging link plate 108 until finger 110 engages bracket 98 and retracts the tension roller. To simplify tape loading the take-up reel 52 is provided with vacuum retaining means to hold the end of the tape in place during the first few turns. As illustrated in FIGS. 4 and 5, the take-up reel 52 has an open top 120 and peripheral perforations 122. A small blower 124, mounted at the side of the take-up reel, is coupled by a hood 126 to the open top 120 to draw air in through perforations 122, as indicated by the arrows in FIG. 5. Hood 126 is supported with minimum clearance above the take-up reel to allow the reel to move out from under the hood. The supply hub 36 incorporates mechanism for automatically clamping the supply reel 42 in place when loaded, so that a positive drive is established for controlling and subsequently rewinding the tape. As illustrated in FIGS. 12 and 13, supply hub 36 is rotatable on the drive shaft 34 and is held in place by a thrust bearing 128 on the upper end of the drive shaft. Below supply hub 36 is a circular cam plate 130 keyed to rotate with drive shaft 34, and on the upper surface of the cam plate are three circumferential ramp cams 132, each having a lower platform 134 and an upper platform 136. The supply hub 36 has three equally spaced radial slots 138 and in each slot is mounted a clamp finger 140. The clamp finger is a generally L-shaped element with one end pivoted on a hinge pin 142 at the outer end of the slot 138, to swing upwardly and radially outwardly and project above boss 38. The other end of the clamp finger 140 has a friction pad 144 to engage and grip the inside wall of the central opening 40 in the supply reel, as in the broken line position in FIG. 12. At the apex of the clamp finger 140 is a roller ball 146 which rolls on one of the ramp cams 132. Each clamp finger 140 is biased downwardly by a spring 148 to keep the roller balls in contact with their respective ramp cams and to keep the clamp fingers normally retracted. In the retracted position the roller balls rest on the lower platforms 134 of the ramp cams. When cam plate 130 rotates relative to the supply hub 36, in the appropriate direction, the roller balls 146 will ride up the ramp cams 132 and raise the clamp fingers 140 to the reel clamping position. Thrust bearing 128 resists the upward load on the supply hub caused by the ramp cam action. When the relative rotation is reversed the clamp fingers will be retracted. Fixed beneath the periphery of supply hub 36 is a bracket 150 carrying a bellcrank 152 which is pivotal on a vertical hinge pin 154. Below the bellcrank and also pivotal on hinge pin 154 is a latch arm 156 having an outwardly projecting latch pin 158. Latch arm 156 is biased outwardly by a spring 160, so that the latch pin 158 projects beyond the edge of the supply hub. Outward movement of both the bellcrank 152 and the latch arm 156 is limited by a stop pin 162 on the supply hub. Latch arm 156 has a coupling pin 164 which projects upwardly through an oversize hole 166 in the bellcrank 152, to couple the two elements together. Fixed on the outer edge of cam plate 130 is an upwardly projecting latch bracket 168, having a socket 170 to receive latch pin 158 and an inclined ramp face 172 to lead the pin into the socket. Bellcrank 152 has an outwardly extending stop arm 174 for engagement with a fixed stop 176 on the side of opening 26. OPERATION In the initial loading position the supply hub 36 and take-up reel 52 are in the forward position, the clamp fingers 140 are retracted and the blower 124 is operating. The blower can, if desired, be running at all times, since the air can be used to cool the interior of the machine. As shown in FIG. 3, a supply reel 42 is inserted into slot 20 and placed over the boss 38 of the supply hub. The free end of tape 89 is pulled out and placed against take-up reel 52, where it will be held by the vacuum. The machine is then started by the appropriate one of controls 18 to carry out the loading operations. The electrical circuitry for operating the machine is not shown since it involves only simple switching and suitable circuits are well known. The unit can also be controlled through a computer terminal 178, or the like, as indicated in FIG. 1. Take-up motor 48 is actuated to wind the tape 89 around take-up reel 52, sufficiently to obtain a driving grip. Motor 32 is also started and carries out the sequence of actions illustrated in FIGS. 15-18. Cam plate 130 is rotated in a clockwise direction and carries supply hub 36 with it, by the frictional coupling of the roller balls 146 on the cam plate. After almost one complete revolution, stop arm 174 strikes the rear of 176 and halts the rotation of supply hub 36. The engagement of the stops also turns bellcrank 152 and extends latch pin 158 outwardly, as in FIG. 16. Cam plate 130 is continuing to turn and latch bracket 168 moves around to engage latch pin 158. The oversize hole 166 allows the latch arm 156 to move back against spring 160, so that the latch pin 158 can ride over ramp face 172 and drop into socket 170, latching the cam plate and supply hub together. Since the stop arm 174 is against stop 176, rotation is impeded. At this point any suitable sensing means can be used, either a position detector at the latch mechanism or a load or resistance detector on motor 32, to initiate the next step. The actuating motor 62 is now started to swing arm 46 to the rear and also pull back the mounting plate 30, which moves the supply hub assembly back away from stop 176, as in FIG. 17, so that rotation can continue. The tape 89 is extended around the head assembly 78, tension roller 90 is raised to engage the tape and the take-up reel 52 stops in the rearmost or operating position, completing the loading operation. The machine is now operable as a conventional tape deck with the appropriate controls. Platform 60 prevents the tape from sagging when wound on the take-up reel 52, but in normal use the tape will be wound tightly enough to stay in flat alignment on the reel. In the unloading sequence the tape is rewound on the supply reel 42, then actuating motor 62 is operated to swing arm 46 forward and to move the supply hub 36 forward on mounting plate 30. Motor 32 is operated to rotate the cam plate 130 counter-clockwise, as in FIG. 18, until stop arm 174 strikes the front of stop 176. This stops rotation of the supply hub 36, so that continued rotation of the cam plate allows the roller balls 146 to ride down the ramp cams 132 and retract the clamp fingers 140. Supply reel 42 can now be removed from the boss 38 and the mechanism is left in the initial loading position for subsequent use. The tape drive unit is thus operable without opening the drawer and with access only through the front slot 20. In operation, the tape and the mechanism are completely enclosed and protected. The actuating mechanism is simple and easy to service and is in a compact configuration which can be installed in a minimum of space.

A magnetic tape drive unit constructed in a horizontal configuration to fit in a drawer or similar low profile installation, the tape being loaded and unloaded through a front slot without the need for access to the mechanism. A supply reel is inserted in the slot and placed on a supply hub, the free end of the tape being applied to a take-up reel which has a vacuum action to retain the tape. The take-up reel is mounted on an arm which swings back in the enclosure and pulls the tape over a guide and head array, the supply reel being simultaneously retracted so that the tape and reels are fully enclosed. After rewinding, the arm swings back and the supply hub is extended to the slot for removal of the tape.

BACKGROUND OF THE INVENTION [0001] Prior art chess sets have had various problems. Among others, chess pieces can easily be lost; the large bulky game board can be difficult to store; and also difficult to transport. Other prior art chess sets have attempted to solve this problem by making smaller, portable game boards and game pieces. However, these sets have had their own problems. It can be difficult to keep playing pieces on the board and once a piece is off the board, it is difficult to store the piece and avoid loss. BRIEF DESCRIPTION OF THE DRAWINGS [0002] FIG. 1 is a perspective view of the partially closed chess set of the subject invention; [0003] FIG. 2 is a perspective view of the board with game pieces placed on hinged shelves; [0004] FIG. 3 is a perspective view of the board at the commencement of the game; [0005] FIG. 4 is a perspective view of the board during game play; [0006] FIG. 5 is a side view of the chess set with one shelf partially open; [0007] FIG. 6 is a schematic view of one embodiment comprising a slanted shelf configuration; [0008] FIG. 7 is a perspective view of the subject invention utilizing a particular shelf configuration with feet; and [0009] FIG. 8 is schematic view of the hinge mechanism for folding the shelves from storage position to play position and vice versa. SUMMARY OF THE INVENTION [0010] In consequence of the background discussed above, and other factors that are known in the field, applicants recognized a need for an improved chess set that would allow players to easily play and maintain their chess board and pieces. Thus, the present invention relates to an improved chess set. More specifically the invention relates to a chess set in which the two halves of the playing board can be folded together to form an interior storage area. Hinged shelves are positioned at the periphery of the chess board. The shelves can swing out and reside on the sides (and/or ends) of the chess board when the board is set for play. When the game is stored, the shelves will swing in so that they can be stored in the interior of the chess board. [0011] In one embodiment, the shelves contain metal that attracts magnets located within the chess pieces. In another aspect of the invention the shelves contain magnets and the pieces have a magnet attracting metal. The board and pieces can be made from wood, metal, plastic, or any other suitable material. There can be a variety of configurations for the shelves and a variable number of shelves. DETAILED DESCRIPTION [0012] Turning now to the drawings and particularly to FIG. 1 , wherein like numerals indicate like parts, there is shown a perspective view of the chess set 100 of the subject invention. The board can be folded in two to form an interior space out of the hollow region. Furthermore, the shelves can be designed so that they fold under the board and the chess pieces on the shelves can be stored in the interior space. Hinge mechanism 102 holds the two sides of the set together and allows for rotation from a closed position to an open position and vice versa. When closed, the chess set provides protection and storage for a plurality of game pieces 108 . Front shelves 112 and side shelves 110 can be rotated on a hinge to move from the closed position shown to a position appropriate for play. The top side of the board 106 (not shown) is the actual game play board. The board, shelves, and game pieces may be constructed of any number of materials including wood, metal, or plastic. Additionally, it is not necessary for all pieces to be constructed of the same material. [0013] Turning to FIG. 2 , the chess set 200 of the subject invention is shown fully open with shelves in the open position. Game pieces 202 rest on the shelves that have been turned on hinges from their closed position, shown in FIG. 1 , to this open position. The shelves may be configured to sit below the level of the playing board or level with the playing board. Game surface 208 contains either a single large magnet or metal element, or a plurality of magnet or metal elements to correspond to either magnet or metal elements in each of the game pieces 202 . If the game board is metal then the game pieces will contain magnet elements. If the game board comprises one or more magnets on its surface then the game pieces will comprise metal elements to allow them to be removably adhered to the board during play. These magnets can be hidden inside the body of the game piece or the board. This connection prevents loss of game pieces and difficulty in playing if game pieces were to shift. Any type of connection mechanism would be useful. Other examples include velcro, buttons, or a host of other male/female type releasable connections. Front shelves 206 and side shelves 204 hold any of the game pieces; although the illustration shows a particular placement of game pieces, any configuration would be possible. The game board, when unfolded, meets at point 210 . There may be some mechanical attachment such as a magnet to hold the two pieces in place. [0014] An alternative magnetized embodiment comprises a board that is magnetized to some degree and attracts a metal element in the game piece. At the center of each square on the game board, there is a hidden magnetized element that is greater in mass than the magnet covering the spaces between the centers of the squares. This feature causes the game pieces to “snap” into position and adds greater security. This may also be accomplished by creating a metal board of a given thickness and having a metal “plug” of a greater thickness under the center of each square. A magnet element in the game pieces will “snap” into position above these metal “plugs.” [0015] FIG. 3 shows a perspective view of the chess set 300 of the subject invention. Side shelves 302 and front shelves 306 have been emptied and the game pieces are on the board in their appropriate places for the start of the game. Connection elements 304 may be a magnet to correspond to metal in the game pieces or metal to correspond to a magnet in the game pieces. The game pieces or shelves may also be constructed entirely of the magnetic or metal material. This connection does not have to be magnetic, alternatively, it may be any removable mechanical connection such as velcro, snap buttons, or a releasable male/female connector. [0016] FIG. 4 is a perspective view of the chess set 400 of the subject invention during game play. As can be seen, the captured pieces can be replaced on side shelves 402 and front shelves 406 during play to allow all players to easily see which pieces are no longer in play. Mechanical connection mechanisms 404 , as described above, may be corresponding metal/magnet pairs, snap buttons, or any other releasable connection. [0017] Turning to FIG. 5 , a side view of the chess set 500 of the subject invention is shown. The front edge of 506 is facing with front shelf 504 turned into place for play. Side shelf 502 is partially rotated between the closed position and the open position. Note that when open or closed, the shelves may be mechanically connected to the board by magnets, snaps, or other connection to hold them in place during play or storage. In this embodiment the shelves' closed position comprises swings down and under the chess board so that pieces can be stored under the board facing horizontally and thus protected from damage by dropping or contact with hard objects. [0018] FIG. 6 shows a cutaway view of an alternative embodiment using a slanted shelf. Shelf 604 is rotated along hinge axis 602 between a closed and open position. [0019] FIG. 7 shows an alternative embodiment of the chess set 700 . This set is constructed entirely of metal and the game pieces would have magnet elements to cause them to adhere to the shelves and game playing surface. The board opens at point 702 using a hinge mechanism. Shelves 704 close to allow game pieces to be stored horizontally inside the chess set and open to allow for game play. This embodiment shows only two front shelves but there may be two front and two side shelves as shown above. The shelves each have optional feet 706 that cause the shelves to remain open when the open chess set is placed on a flat surface. [0020] FIG. 8 shows a side schematic view of the chess set illustrating the movement of a shelf from a closed position, through its rotation, to the open position with a game piece connected. The shelf rotates along hinge axis 802 . This hinge can be any appropriate hinge configuration that allows for free rotation. The game piece is magnetically attached in this embodiment at point 806 . Foot 808 operates as described above to hold the shelf stable when the board is placed on a flat surface. [0021] The preceding description has been presented only to illustrate and describe the invention and some examples of its implementation. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible and would be envisioned by one of ordinary skill in the art in light of the above description and drawings. [0022] The various aspects were chosen and described in order to best explain principles of the invention and its practical applications. The preceding description is intended to enable others skilled in the art to best utilize the invention in various embodiments and aspects and with various modifications as are suited to the particular use contemplated.

Chess set comprising a housing that closes and creates a space to store game pieces. Shelves are rotatably attached to the side of the board to move from a close position inside the housing to an open position adjacent to the playing board. Game pieces are adhered to the shelves and to the board via a mechanical connection that is releasable such as a magnet, button, adhesive, or other suitable mechanism.

RELATED APPLICATION INFORMATION [0001] The present application claims priority under 35 U.S.C. section 119(e) to provisional application Ser. No. 60/931,220 filed May 22, 2007, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention is related to radio frequency (RF) on frequency repeaters (OFR) which are used for re-transmission of RF signals from and to Base Stations (BTS) and User Equipment (UE). More particularly, the present invention is related to radio frequency repeaters used in wireless communication applications such as cellular based networks where signals must be retransmitted in order to enhance quality of service within such network. [0004] 2. Description of the Prior Art and Related Background Information [0005] Most conventional on frequency repeaters are used in modern telecommunication systems in order to provide enhancement in coverage within a cellular network. In such networks, to preserve signal coverage in areas obstructed by terrain or man made obstructions, repeaters are used to re-transmit signals to and from BTS. Hence, the repeater operation and its performance provide for extended signal coverage not otherwise possible. [0006] Even from the early days of Amplitude Modulation (AM) and later Frequency Modulation (FM) repeaters used in VHF business bands and in more recent cellular telephony, the repeaters have been mostly used in conjunction with Base Stations to achieve the extend coverage of BTS over obstructions such as hilly terrain and the like. On frequency repeaters are designed to solve coverage problems due to weak signals in outdoor and in some instances in indoor locations using balanced amplification of uplink and downlink signals. [0007] In an on frequency repeater the repeater does not utilize frequency translation. In other words reception frequency and the transmission frequency, for example in downlink direction, are the same, while similarly, reception frequency and the transmission frequency for uplink direction are the same. For example, a repeater operating in UMTS band would receive downlink signals from the BTS in 2110 to 2170 frequency range, amplify them and retransmit toward UE, for example a mobile telephone. Similarly, in the uplink direction the repeater operating in UMTS band would receive uplink signals from UE in 1920 to 1980 MHz band, amplify them, and retransmit toward BTS. Conventionally the antenna in communication with the BTS is referred to as a donor antenna and the antenna used to re-transmit signals to UE's is referred to as a service antenna. [0008] Since the repeater receives and transmits on the same frequency there is always a possibility that the repeater may oscillate due to a self induced radio signal feedback from transmitting to receiving antenna. Due to the bi-directional nature of an on frequency repeater the radio signal feedback may occur in either the downlink or uplink direction. Various methods have been proposed to attenuate the radio signal feedback and to sufficiently reduce the received portion of the transmission radio wave of repeater. Some of these methods utilize directional antennas, while other methods propose utilization of a plurality of antennas to reduce such feedback path. [0009] One of the primary commissioning issues with on frequency repeaters is to provide sufficient radio frequency attenuation between the two repeaters' antennas so as to prevent a self induced radio signal feedback. Commissioning of the repeater requires careful placement and orientation of antenna's and ability to detect and mitigate feedback oscillation. Additionally, operation of an on frequency repeater in a wireless network must be oscillation free while being capable of detecting feedback oscillation, whilst operating with any combination of wireless signal formats such as but not limited to TDMA, GSM, CDMA, WCDMA and others as well being oscillation free when no signals are present at either antenna. [0010] Full time feedback oscillation detection is mandated due to changing operating circumstances, for example, the growth of trees in the vicinity of the wireless repeater may cause the multi path reflection and scattering of radio waves to vary significantly, therefore changing coupling between donor and service antennas of the repeater and cause it to oscillate. When the repeater oscillates, the output signal of the wireless repeater is conventionally hard limited to a predetermined output power level by an Automatic Gain Circuit (AGC) circuit. [0011] An Automatic Gain Circuit (AGC) circuit is primarily used to limit output signal power of the repeater to predetermined power level. Since it is possible for UE, such as a mobile telephone, to be in near proximity of a repeater, the uplink communication radio wave signals may be of a sufficient level to cause distortion and thus cause harmful interference to adjacent services. Under these operational conditions, the repeater's output signal in the uplink path may increase, but due to action of the AGC will be kept at a safe, predetermined maximum output level. AGC is used to limit the output signal of the uplink, and coincidently downlink path, to a predetermined maximum output level. [0012] The on frequency repeater (OFR) must be equipped with an AGC circuit capable of distinguishing between its feedback oscillation and input signals transmitted by numerous UE's. Many conventional AGC circuits utilize low pass filtered output control voltage which is directly proportionate to the detected signal envelope, whereas when the repeater oscillates the input signal levels increase rapidly until operational limits are reached. Conventional AGC circuits are only marginally able or insufficient to resolve the onset of oscillation and thus additional means must be employed to determine oscillatory condition. [0013] Previous attempts to detect oscillatory condition in on frequency repeater focused primarily on received signal envelope detection and post filtering. This approach has severe limitations as it relies on inherent nature of received signal envelope. In one such example, as described in U.S. Pat. No. 5,815,795, an AGC system is equipped with oscillation detecting circuit comprising a band pass filter (BPF) in addition to an envelope detector and a low pass filter. Due to the burst nature of TDMA telephony signals each frame in TDMA system is divided into a plurality of time slots allocated to mobile stations (UE's). The duration of the TDMA frame is 20 ms and the center frequency of the band pass filter is set to 50 Hz. Output of this band pass filter is applied to alternating current level detector which is used to establish presence of TDMA signal. If the repeater self oscillates, a BPF filter will block all signals since the oscillatory condition envelope is constant. [0014] Accordingly, an improved method for detecting oscillation in an on frequency repeater is needed. SUMMARY OF THE INVENTION [0015] The present invention provides a system and method of automatically detecting if an on frequency wireless repeater is oscillating. Accordingly, the present invention also provides an improved on frequency repeater. [0016] In a first aspect the present invention provides an on frequency repeater for a wireless network, comprising a first antenna that is directed toward a first selected location in the wireless network to receive RF signals from the first selected location, an amplification chain coupled to the received signal and amplifying the level of the received signal to generate an amplified RF signal, and a second antenna spaced apart from the first antenna and receiving and transmitting the amplified RF signal to a second location in the wireless network. The repeater further comprises a feedback oscillation detection circuit coupled to the amplification chain in a gain control loop including a gain adjustment circuit and a gain control circuit, the feedback oscillation detection circuit detecting a saw tooth waveform in the gain control loop to detect onset of feedback oscillation between the first and second antennas. [0017] In a preferred embodiment of the on frequency repeater the gain control loop further comprises a signal level detector coupled to the amplification chain. The signal level detector preferably comprises an envelope detector. The gain control loop preferably also further comprises an RC filter circuit coupled to the output of the signal level detector. The amplification chain preferably includes an intermediate frequency amplification stage and an RF power amplifier and the signal level detector may be coupled to the output of the intermediate frequency amplification stage. Alternatively, the signal level detector may be coupled to the output of the RF power amplifier. The first antenna may be a donor antenna that is directed toward a selected base station and the second antenna a service antenna that is directed toward a selected user coverage area. The on frequency repeater may further comprise an uplink path between the second antenna and the first antenna, the uplink path comprising a second amplification chain receiving and amplifying RF signals from the second antenna and providing them to the first antenna for transmission to the first location. The gain adjustment circuit may comprise a voltage variable attenuator. The feedback oscillation detection circuit may issue a feedback oscillation warning signal upon detecting the saw tooth waveform indicating onset of feedback oscillation. The feedback oscillation detection circuit may also reduce a gain setting of the amplification chain upon detecting the saw tooth waveform indicating onset of feedback oscillation. [0018] In another aspect the present invention provides an on frequency repeater for a wireless network, comprising a first antenna that is directed toward a first selected location in the wireless network to receive RF signals from the first selected location, an amplification chain coupled to the received signal and amplifying the level of the received signal to generate an amplified RF signal, a nonlinear gain expander circuit coupled in the signal path of the amplification chain, and a second antenna spaced apart from the first antenna and receiving and transmitting the amplified RF signal to a second location in the wireless network. The repeater further comprises a feedback oscillation detection circuit coupled to the amplification chain in a gain control loop including a gain adjustment circuit and a gain control circuit, wherein the feedback oscillation detection circuit is coupled to control the gain expander circuit to selectively provide a nonlinear gain response, the feedback oscillation detection circuit detecting a saw tooth waveform in the gain control loop to detect onset of feedback oscillation between the first and second antennas during operation of the gain expander circuit. [0019] In a preferred embodiment of the on frequency repeater the feedback oscillation detection circuit controls operation of the gain expander circuit to provide the nonlinear gain expansion when the repeater is not in user service. The feedback oscillation detection circuit preferably controls operation of the gain expander circuit to provide the nonlinear gain expansion periodically for oscillation monitoring. [0020] In another aspect the present invention provides a method for detecting feedback oscillation in a repeater having first and second antennas and one or more amplification paths. The method comprises detecting a signal level in the amplification path, controlling the gain of the amplification path in response to the detected signal level with a gain control signal, and detecting a periodic nonlinear pattern in the gain control signal corresponding to onset of feedback oscillation between the antennas. [0021] In a preferred embodiment of the method for detecting feedback oscillation in a repeater the periodic nonlinear pattern in the gain control signal comprises a saw tooth pattern. Detecting a signal level in the amplification path preferably comprises detecting a signal envelope. The method for detecting feedback oscillation in a repeater may further comprise filtering the detected signal envelope. The method may further comprise selectively providing an additional nonlinear gain to the amplification path and the detecting of a periodic nonlinear pattern in the gain control signal is performed while providing the additional nonlinear gain. The additional nonlinear gain to the amplification path is provided when the repeater is not in user service. [0022] Further features and advantages of the present invention will be appreciated from the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0023] FIG. 1A is a schematic representation of a Cellular Network with an on frequency repeater. [0024] FIG. 1B is a top level schematic of a band select on frequency repeater. [0025] FIG. 2 is a schematic drawing of an uplink path of the on frequency repeater with AGC in accordance with a first (and second) embodiment of the invention. [0026] FIG. 3A is a simplified system stability schematic drawing. [0027] FIG. 3B is a system stability schematic drawing identifying control elements of the on frequency repeater with AGC in accordance with one embodiment of the invention. [0028] FIG. 3C is a system stability schematic drawing identifying control elements of the on frequency repeater with AGC in accordance with a second embodiment of the invention. [0029] FIG. 4 is a graphical representation of the dynamic gain response of the on frequency repeater illustrating AGC behavior in accordance with the first or second embodiment of the invention. [0030] FIG. 5 is a system stability schematic drawing identifying control elements of the on frequency repeater with AGC in accordance with a third embodiment of the invention. [0031] FIG. 6 is a graphical representation of the dynamic gain response of the on frequency repeater illustrating AGC behavior in accordance with the third embodiment of the invention. [0032] FIG. 7 is a graphical representation of the AGC control voltage while the repeater is marginally stable (onset of oscillation is imminent). DETAILED DESCRIPTION OF THE INVENTION [0033] Reference will be made to the accompanying drawings, which assist in illustrating the various pertinent features of the present invention. The present invention will now be described primarily in solving feedback stability detection and mitigation while operable with plurality of signals, it should be expressly understood that the present invention may be applicable in other applications where feedback determination in variable signal level environment is required or desired. In this regard, the following description of on frequency repeater (OFR) that solves radio signal feedback between donor and service antennas is presented for purposes of illustration and description. [0034] The present invention provides an improved On Frequency Repeater (OFR). In a preferred embodiment of the present invention, an on frequency repeater (OFR) is provided for a cellular network system having a plurality of BTS and UE's. The OFR includes a donor antenna that is directed toward a selected base station to receive and transmit RF signals to and from such base station. The OFR includes a first amplification chain receptive to the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal in the downlink direction. The repeater further includes a service antenna located at some distance from the donor antenna. The service antenna is driven by downlink amplified signals, and the service antenna positioned to transmit RF signals within a local area providing communication means to UE's located wherein. The aforementioned description provides a brief description for an OFR operating in the downlink direction between the base station and the subscriber units near the repeater. Similarly, the service antenna provides an uplink coverage area proximate to such repeater. Signals received by the service antenna are applied to a second amplification chain receptive to the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal in the uplink direction. Amplified uplink signals are coupled to the donor antenna. [0035] The RF signals received by the donor antenna and the RF signals transmitted by the service antenna may be at substantially the same frequency in the downlink direction. The RF signals received by the service antenna and the RF signals transmitted by the donor antenna may be at substantially the same frequency in the uplink direction. The amplifier includes AGC and RF circuitry therein to substantially prevent feedback oscillation. The circuitry may advantageously prevent occurrence of feedback oscillation by continuously testing for same. The AGC circuitry may reduce amplifier gain if conditions favoring onset of oscillation exist. [0036] The basic circuit schematic of a preferred embodiment of the OFR of the present invention is shown in FIG. 2 , and is described below. First, however, the basic operational characteristics of a repeater employed in cellular network will be described in relation to FIG. 1A and FIG. 1B . [0037] A repeater system 10 implemented in an illustrative cellular network 1 is shown in FIG. 1A . As can be seen, the repeater system 10 is located on the side of a hill, preferably on the side of the hill facing away from BTS 2 antennas. BTS 2 provides wireless communication services to UE's 5 in the adjacent area. OFR 10 is in communication with BTS 2 and thus extends effective coverage of such BTS 2 to provide service coverage to UE's 6 in extended coverage area 4 . Due to terrain features extended coverage area 4 is blocked from direct coverage by BTS 2 . Both near 3 and extended 4 coverage areas may have one or more UE's 5 & 6 (cellular or other wireless telephones). [0038] The wireless telephone system 1 may include a plurality of base stations (BTS) 2 located in operational vicinity to the OFR 10 . As is well known, each of these additional base stations 2 (not shown) may operate on different transmit and receive frequencies and may utilize CDMA, TDMA, or GSM technologies. The present invention is capable of concurrent operation with the above mentioned systems, accordingly the embodiments described herein all may refer to any one transmission format as well as in combination. [0039] OFR 10 is typically positioned in the area where direct signals from primary BTS 2 are attenuated by local terrain. Generally, donor 26 antenna is a directional antenna advantageously mounted and oriented toward BTS 2 . Any suitable directional antenna, for example Yagi, can be used to establish OFR 10 to BTS 2 radio link. Donor 26 antenna is coupled to respective connection 22 -A port ( FIG. 1B ) of the OFR with a suitable radio guide 24 means, for example coaxial cable. Service area 12 antenna is coupled to respective connection 16 -A port of the OFR 10 . Service area 12 antenna is coupled with a suitable radio guide means 14 to provide broad coverage to UE's 6 in extended 4 coverage area. [0040] With reference to FIG. 1B basic features of the OFR will now be described. OFR 10 comprises two independent amplification chains 18 & 20 . First amplification chain 18 is used to amplify signals in downlink direction, wherein RF signals are received from BTS 2 transmitter to be retransmitted to UE 6 . Similarly, second amplification chain 20 is used to amplify signals in the uplink direction, wherein RF signals are received from UE's 6 and retransmitted toward BTS 2 . Frequency selective duplexers 16 & 22 provide frequency separation between various signal paths so that the same antennas 26 & 12 can be used concurrently for OFR 10 to BTS 2 and OFR 10 to UE's 6 communication paths. [0041] With reference to FIGS. 1B and 2 detailed features of a preferred implementation of the OFR will now be described. In FIG. 2 details for uplink amplification 20 chain are described, whereas downlink amplification 18 chain has been omitted for clarity. The two amplification 18 & 20 chains in practice tend to be very similar and may share similar operational parameters. Alternatively, asymmetric amplification chains may be operatively similar. Suitable implementation details will be appreciated by those skilled in the art from the description of uplink amplification chain 20 . [0042] Uplink signals from UE's 6 are received by service antenna 12 and coupled to antenna port 16 -A of first diplexer 16 . Diplexer can be thought as a dual port band pass filter having one common port. Downlink signals transit with minimum attenuation from port 16 -A toward port 16 -U, while being effectively attenuated from reaching downlink port 16 -D. Output signals from uplink 16 -U port are directed toward input port of the Low Noise Amplifier 101 (LNA). Output of the LNA 101 is coupled to a first RF band-pass filter 103 which provides additional uplink signal filtering and image signal rejection. Output of the first RF band-pass filter 103 is coupled to a second amplifier 105 before being applied to the RF port of down mixer 107 . [0043] Mixers are well known devices and are used for signal frequency conversion. A mixer converts RF power from one frequency into power at another frequency to make signal processing, such as amplification and or filtering easier. Each amplification chain 18 & 20 uses down 107 and up 125 mixers to perform RF to Intermediate Frequency (IF) and IF to RF conversion, respectively. Each amplification chain employs a Local Oscillator (LO) synthesizer 123 to provide Center Frequency selection for the OFR operational band. A detailed description for a channel and band selective repeaters can be found in U.S. Pat. Nos. 5,809,398 and 5,987,304, respectively, which are assigned to current assignee and incorporated herein by reference. [0044] The IF output port of the down 107 mixer is coupled to IF pass band filter 109 . The IF processing strip will now be described. The IF pass band filter 109 provides suitable out of band attenuation so as to select only a narrow selection of frequencies that may contain desired signals for re-transmission toward BTS 2 . Continuing on, the filtered IF passband signal at the output port of the IF bandpass filter 109 is coupled to AGC controlled amplitude means 113 . AGC controlled amplitude controlled means 113 can be implemented with a suitable circuit known in the art such as a voltage variable attenuator suitably adapted to operate at IF frequency band. [0045] Additional IF gain stages 115 and 117 are used to increase amplitude level of the filtered IF passband to suitable levels before being coupled to IF port of the up-conversion mixer 125 . LO signal input to up-conversion mixer 125 is supplied by the LO synthesizer 123 . Since the identical LO frequency is used as in down conversion mixer 107 , no RF frequency shift is incurred. [0046] RF output port of the upconversion mixer 125 is coupled to a second RF bandpass filter 129 . Second RF bandpass filter 129 is used to filter out and essentially attenuate LO and unwanted side band signal resultant from up conversion mixer 125 operation. Output port of the band pass filter 129 is coupled to PA 131 section of the amplification 20 chain. Suitably amplified RF signals are coupled to uplink port of the second diplexer 22 before being applied to donor antenna 26 via suitable radio signal guide means 24 . [0047] Signal level detection 119 can be implemented with a suitable envelope detector, such as RF Detector/Controller AD8314 manufactured by Analog Devices Inc, Norwood, Mass. 02062-9106. This device provides is a complete subsystem for the measurement and control of RF signals in the frequency range of 100 MHz to 2.7 GHz, with a typical dynamic range of 45 dB. However, numerous envelope detector alternatives are readily available. In first preferred embodiment signal detector 119 has its input coupled 127 at the output IF stage 117 with a suitable coupler 121 . IF strip signal level detection can be readily implemented wherein gain variation of subsequent stages is acceptably small or controlled by other means. Conversely, if gain variation of PA stages 131 is unacceptably high signal detector 119 may be coupled 127 to the output of PA with a suitably constructed signal coupler 133 as indicated by the dashed line. Detected signal envelope from detector 119 is coupled to AGC control and feedback oscillation determination module 111 . [0048] Output of the signal level detector 119 is coupled to AGC Control Module 111 for AGC level setting and self feedback oscillation determination. AGC Control Module 111 accepts control signals from Master Control Unit (MCU), not shown as well as reports self feedback oscillation presence when detected. AGC Control Module 111 may include a circuit or circuits used for determining presence of a saw tooth signal detected by RMS detector 119 for determining onset of self feedback oscillation (as shown in FIG. 7 and as discussed below). The saw tooth wave form detection function can be implemented with either analog or preferably with a digital signal processor (DSP). By utilizing DSP hardware and Fourier transforms and other signal processing techniques additional flexibility not afforded by analog circuits is readily attained. [0049] Feedback oscillation in amplification chain 20 can be analyzed using a simplified arrangement illustrated in FIG. 3A . As is well known in the art oscillatory condition occurs when there is sufficient positive gain balance in the feedback oscillator loop. All feedback oscillators require some means which provide gain 36 combined with a feedback 28 arrangement that further send some of the system's output back to be re-amplified after a suitable time delay. For an on frequency repeater, gain is provided by many amplification stages, while signal delay is provided by the numerous filters used in amplification chain 20 construction. [0050] As shown in FIG. 3A , amplification chain and related components are simplified to unitary amplifier 36 element which has a voltage gain A(s) whose output is coupled to input with a feedback path 28 . Feedback path 28 returns a part, FB(s), of the output voltage to the amplifier's 36 input. Henceforth, consider that both amplifier 36 and feedback 28 path have complex amplitude and phase signal response and thus any signal analysis must take complex frequency response of the two into account. [0051] For basic oscillatory OFR analysis FIG. 3A is used, wherein amplifier 36 and feedback path 28 form a positive feedback (closed) loop. Onset of oscillation commences from initial input signal fluctuation: [0000] V in ( t )= V 0 −j2πft [0052] And consequently amplifier 36 will produce the following signal output at the amplifier's 36 output terminal: [0000] V out ( t )= A ( f ) V 0 −j2πft [0053] A portion of the output V out signal is feedback to amplifier input terminal: [0000] V′ in ( t )= A ( f ) FB ( f ) V 0 −j2πft [0054] The new V in ′(t) will be again amplified and feedback back to the input terminal of the amplifier. After n trips around the loop the amplitude value of the feedback signal will be: [0000] | V|=|A ( f ) FB ( f )| n |V 0 | [0055] If the value |A(f)FB(f)|<1 then oscillation will eventually dampen out, however if |A(f)FB(f)|≧1 oscillation will grow in amplitude with every single path through of the feedback loop provided ∠A(f)+∠FB(f)=2 πn where n=1,2,3, . . . Marginal instability or at least constant amplitude oscillation will occur when: |A(f)FB(f)|=1. [0056] Feedback oscillation can be viewed as a summation of previous signal pass through being stacked to the end of the prior signal perturbation with the same sinusoidal phase. Oscillations, for |A(f)FB(f)|≧1, may start with application of initial energy perturbation at the input of the amplifier. [0057] As discussed hereinabove, basic oscillation analysis of FIG. 3A can be further expended to the OFR's specific circuit implementation. With reference to FIGS. 3B and 3C selected OFR circuit elements are combined into functional sub-modules to facilitate oscillation analysis. In order to simplify oscillation analysis several elements of FIG. 2 are combined into equivalent functional modules. In reference to FIG. 3B circuit module S 1 ( 30 ) combines service antenna 12 , service antenna feed line 14 , first duplexer 16 , LNA 101 , Bandpass filter 103 , and second amplifier 105 . Similarly circuit module S 2 ( 32 ) provides equivalent amplitude and phase behavior for the following circuit elements: upconversion mixer 125 , second bandpass filter 129 , PA module 131 , coupler 133 , second duplexer 22 , donor antenna feed line 25 and donor antenna 26 . Similarly, In FIG. 3C circuit module S 3 ( 34 ) provides equivalent amplitude and phase behavior for the following circuit elements: second duplexer 22 , donor antenna feed line 25 and donor antenna 26 . [0058] It is highly desirable for the OFR to provide oscillation free operation and consequently it is equally paramount for repeater control circuits to determine operational conditions favoring or leading toward the onset of feedback path oscillation. OFR implementations have utilized band pass RF amplifiers with Automatic Gain Control system (AGC) that allows for a constant output power, Pout (over input power (Pin), temperature range, etc) operation, together with feedback coupled donor and service antennas as a part of a positive RF feedback 28 path. Under nominal operational conditions when feedback closed loop gain balance is less than <1 feedback 28 loop path may create linear amplitude distortions in the output amplified signal passband. Linear amplitude distortions can be readily observed at the output spectrum of the OFR and appear as gain ripple of the frequency response or as output noise floor ripple. [0059] Through experimental measurements it has been determined that periodicity between these ripples depends on a total group delay in closed RF loop including signal propagation time in the feedback 28 between service 12 and donor 14 antennas. Ripple peak maximums correspond to |A(f)FB(f)|→1 approaching unity, i.e. onset of positive feedback 28 ; meanwhile minimum peak values correspond to negative feedback. Based on spectral measurement performed on OFR it has been estimated that 3 dB (peak to peak) amplitude ripples indicate that feedback 28 loop gain is −15 dB (15 dB margin) less than repeaters' gain in the forward direction. From practical consideration placement of service 12 and donor 24 antenna's typically yields better than 15 dB feedback margin provided that installation site allows for sufficient antenna separation. Under less than adequate installation situation, active stability monitoring is required. [0060] Active stability monitoring is achieved through AGC voltage monitoring. With Reference to FIG. 3B AGC circuit monitoring has been implemented which detects the onset of feedback oscillation. AGC circuit provides gain control over various input signal levels. AGC response time is primarily determined by response time of RMS detector 119 and combination of Rf 135 and Cf 137 . AGC control loop comprises the following circuit elements: AGC control 111 , AGC variable element 113 , First IF Gain stage 115 , Second IF Gain stage 117 , directional coupler 121 , RMS detector 119 , video filter R f 135 & C f 137 . To simplify overall analysis pertaining to AGC circuit behavior noncontributory circuit elements are replaced with equivalent circuit elements. Equivalent circuit elements S 1 30 and S 2 32 are used to combine circuitry outside of AGC control loop. It is assumed (for sake of analysis) that circuit elements S 1 30 and S 2 32 do not contribute significantly to gain variation or their overall parametric changes are insignificant against AGC circuit actions. [0061] Donor 26 to service 14 antenna feedback coupling is substituted by equivalent “FP” 28 block. Assign total Gain of the two amplifier stages 115 and 117 to a transfer function G PA (P OUT ) which is dependent on the output power level. The AGC circuit control element transfer function is G AGC (V C ) and the amount of signal feedback between donor 26 to service 14 antenna as function of distance is G FB (Dist). As it was noted before, oscillation condition appears when total gain in the closed loop is equal to or more than 1 and is shown in eq 1. [0000] G AGC  ( V C ) * G PA  ( P OUT ) * G FB  ( Dist ) ≥ 1 ,  or   G AGC  ( V C ) * G PA  ( P OUT ) ≥ 1 G FB  ( Dist ) ( 1 ) [0062] Isolation as a function of distance function Iso(Dist) can now be written: [0000] or Gain( V C , P OUT )≧Iso(Dist)   (2) [0063] where: [0000] Gain  ( V C , P OUT ) = G AGC  ( V C ) * G PA  ( P OUT ) - total   gain , Iso  ( Dist ) = 1 G FB  ( Dist ) - isolation   between   antennas . [0064] Isolation Function Iso(Dist) vs. Gain(V C , P OUT ) are presented in FIG. 4 ( 400 ). Two different operating scenarios will now be described with reference to FIG. 4 and FIG. 7 . [0065] Under first operating conditions 402 donor 26 and service 14 antennas are separated by a Dist 1 such that feedback coupling Iso(d 1 ) provides for oscillation free operation. Under such conditions total gain Gain(V C , P OUT ) even when set at maximum value is much smaller than Isolation Function Iso(Dist). It should be noted that Isolation Function Iso(Dist) is dependent on other variables other then separation distance, such as antenna directivity, surrounding object reflectivity, multipath propagation and others. These contributory environmental variables tend to be secondary in nature, but nevertheless their contributions should be carefully considered by those skilled in the art during OFR installation planning and implementation. [0066] Under second operating conditions ( 404 & 406 ) donor 26 and service 14 antennas are separated by a distance d 2 . Distance d 2 antenna separation is a critical separation distance that results in feedback coupling Iso(d 2 ) function to provide for onset of feedback oscillation. With such antenna separation distance d 2 OFR amplification chain 36 will experience onset of feedback oscillation described in detail by the following operational sequence. [0067] To simplify operational sequence analysis, it is assumed that the OFR has no input signals present at the service antenna. Under such conditions the AGC control circuit 111 would command AGC control element 113 , which can be a voltage variable attenuator, to a minimum allowable attenuation setting so as to provide a maximum gain 404 for the OFR. Corresponding control signal Vc value for a maximum gain setting is Vc 1 . Through extensive experimentation it was determined that self oscillation onset will commence at very low output power level P( 1 ) which corresponds to feedback input signal M 1 . Typically, M 1 signal is a combination of spurious and noise signals which contribute to the oscillation onset. [0068] Once the oscillation feedback starts the output power levels increases rapidly from very low power until output stage saturation. Curve 404 shows power increase from P( 1 ) to P( 2 ). Oscillation rapid signal growth is detected by AGC detector 119 , but its output is low pass filtered through Rf 135 and Cf 137 . Hence, the AGC 111 control module is slow to respond to such rapid output power increase. Oscillatory signal increase (oscillatory power vs. time) takes place rapidly and is governed by the RF bandwidth of the amplification chain 36 . [0069] Timing measurements indicate P( 1 ) to P( 2 ) transitory rate (time=0 to t 1 ) on the order of 100 nSec whilst AGC circuit time constants are typically much slower. The output power of the amplification chain 36 quickly approaches saturation power levels at which time the overall Gain(V C , P OUT ) begins to decrease (P( 2 ) to P(sat)). [0070] Once the output power of the amplification chain 36 reaches saturated power level it will remain at saturated power level unless output devices fail or AGC limits output power. Once AGC overcomes its response time constant the Gain(V C , P OUT ) will be reduced. With reduction of Gain output power will be first reduced from P(sat) to P( 3 ) due to reduction in gain as controlled by AGC. From P( 3 ) the output power will further be reduced due to AGC control voltage vc 2 and slow time constant which effectively reduces output power level along second 406 curve. Once output power is below P( 3 ) oscillation will rapidly subside as AGC have reduced available gain below oscillation feedback threshold. Oscillation will cease and output power level will drop below P( 1 ) on the second gain curve. [0071] Since there is no longer any measurable output power level (just thermal noise) the AGC will slowly increase available gain until there is enough gain for feedback oscillation to re-start again. Hence, the process is repeatable as long as feedback margin FB is below stability margin. The above mentioned system transitions can be readily monitored and recognized by monitoring AGC control voltages shown in FIG. 7 . The saw tooth waveform has a characteristic period (T) and shape making its detection straightforward. For example, as noted above this saw tooth waveform detection may be implemented by a DSP in AGC control module 111 . When oscillation is detected AGC control module 111 sends an OSC Monitor signal to the MCU which may provide an oscillation warning signal to the operator. Also AGC control module 111 may reset the AGC control voltage to a lower level to eliminate oscillation or reduce an amplification setting of an amplifier stage in the amplification chain. [0072] The saw-toothed AGC oscillation is highly dependent on having gain expansion in the amplification chain. Gain expansion is equivalent to having a non-linear response and is highly undesirable in repeaters operating with multiple simultaneous signals as it may result in higher intermodulation products. One way to avoid introduction of higher intermodulation product levels is to employ linear amplifiers that provide linear phase and amplitude response over dynamic range and introduce gain expanding 139 circuit on as needed basis. In FIG. 5 a gain expanding “rabbit circuit” 139 is used to alter dynamic gain response on as needed basis. Gain expanding 139 circuit (or rabbit) is enabled to alter dynamic gain response on as needed basis via control line 141 . Such dynamic gain expanding circuit can be implemented using either a variable gain amplifier (VGA) or with a fast switching bi-state attenuator. The aforementioned devices and circuits topologies are commercially available and can be implemented by a skilled artisan. The control line 141 provides a suitable control signal to provide the desired nonlinear gain expansion under the control of the AGC control module 111 . This may be provided by a suitably programmed DSP. For example oscillation detection can be periodically scheduled to run or it can be enabled under certain operating conditions. [0073] The above AGC detection method can not be readily adapted to repeaters equipped with linear amplifiers. In wireless telephony linear amplifiers are used to provide linear operation so as to not introduce IMD's when amplifying multiple received carrier signals and different signal modulation schemes, such as WCDMA. Coincidently, a linear amplifier will exhibit a flat amplitude (AM-AM) and phase (AM-PM) dynamic response. An amplifier operating in Class A bias will have such response and therefore no oscillation transitory can be readily identified. [0074] Hereinabove described oscillation detection method can be readily used in narrow passband, channelized repeaters where only one carrier signal is amplified, for example GSM. In such GSM repeaters Class AB biased amplifiers can be readily used. Class AB biased amplifier may provide adequate IMD levels while providing desired AM-AM dynamic amplitude behavior. For multi carrier amplification and/or broad band repeaters a linear operation must be maintained and conventionally designed class AB biased amplifiers may not offer sufficient linearity for a majority of applications. [0075] The AGC oscillation detection method can be adapted to a repeater without degrading linear operation. With reference to FIG. 5 and FIG. 6 oscillation feedback detection will now be described. In FIG. 5 a feedback oscillation 28 path provides signal passage—similar to the earlier description. To reduce non-essential circuit clutter circuit module S 1 ( 30 ) combines service 12 antenna, service antenna feed line 14 , first duplexer 16 , LNA 101 , Bandpass filter 103 , and second amplifier 105 and down conversion 107 mixer. Similarly, circuit module S 3 ( 34 ) provides equivalent amplitude and phase behavior for the following circuit elements: second duplexer 22 , donor antenna feed line 25 and donor antenna 26 . [0076] As described herein a feedback path FP ( 28 ) provides positive feedback path between donor 26 and service 12 antennas. The feedback signal is passed through S 3 ( 34 ) equivalent circuit module and coupled to AGC 113 . Output of AGC 113 is coupled through IF gain amplification stages ( 115 & 117 ) before being coupled to up-mixer 125 . Output of the up-conversion mixer 125 is band pass filtered 129 to remove LO carrier and unwanted sideband before being coupled to a controlled rabbit circuit 139 . Output of the rabbit circuit is coupled to power amplification stage 131 (PA). Output of PA 131 stage is sampled with a directional 133 coupler. Coupler 133 output through port is coupled to equivalent circuit module S 3 34 which provides a source signal to feedback 28 path. [0077] Coupler 133 coupled port is coupled to an envelope signal detector 119 with its output low pass filtered through R f 135 and C f 137 . Low pass filtered envelope signal is coupled to AGC control circuit 111 . AGC control circuit 111 receives MCU control commands under which control, among other things, whether controlled rabbit circuit 139 is enabled or alternatively disabled. An MCU feedback voltage is provided, which is used to establish presence of the FP oscillation. Primarily AGC control circuit 111 controls AGC 113 to provide desired gain control for repeater amplification chain. [0078] Controlled rabbit circuit 139 , when enabled, provides a gain expansion region 606 between output power level Pd( 1 ) and P( 2 ) along Gain vs. Ouput Power level along curve 604 . When rabbit circuit 139 is disabled Gain vs. Output power level is slightly increased and returned to a linear condition as indicated by curve 604 -a (dashed line). Typically the repeater is operated with rabbit circuit 139 disabled. Rabbit circuit 139 is typically enabled under selective operational conditions such installation procedure, during prolonged AGC operation or when excessive signal levels have been detected. [0079] Since rabbit circuit 139 introduces non-linear amplitude response its enablement should be limited to periods when uplink path of OFR is not actively re-transmitting user traffic. Numerous detection schemes can be employed for detecting UE traffic presence (or absence) and can be readily adapted by those skilled in the art. [0080] The above description is not intended to limit the invention to the form disclosed herein. Accordingly, variants and modifications consistent with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain modes known for practicing the invention disclosed herewith and to enable others skilled in the art to utilize the invention in equivalent, or alternative embodiments and with various modifications considered necessary by the particular application(s) or use(s) of the present invention.

An on frequency repeater for wireless networks with feedback oscillation detection is disclosed. The on frequency repeater includes an automatic gain control loop which samples amplified signal envelope. The automatic gain control loop is monitored and a characteristic saw tooth pattern in the gain control loop indicating feedback oscillation is detected. A nonlinear gain expander circuit may be periodically activated to allow feedback oscillation detection in repeater applications employing linearized amplifiers.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an accumulator or receiver dryer and a method of making the same, for use in an automobile air conditioning system. More particularly, the present invention relates to packaging replaceable desiccant in an accumulator or receiver dryer. 2. Description of the Prior Art In air conditioning systems, and particularly those for automotive applications, the accumulator is typically located at the outlet end of the evaporator. Its purpose is to filter out any particulates in the refrigerant fluid and remove any moisture present in the refrigerant vapor. A desiccant material is placed within the accumulator housing specifically for the purpose of removing the unwanted moisture from the refrigerant vapor. During assembly of the accumulator, it is important to avoid saturating the desiccant material. Handling the desiccant material during the assembly process introduces the potential for saturation from exposure to humidity of air in the assembly area. Therefore, handling should be kept to a minimum. A fully sealed unitary housing is a desirable feature of an accumulator. A one-piece construction without joints that may leak is an objective of accumulator assemblies. The simplicity of a unitary housing is also an important feature, which reduces costs and improves reliability. Such a unitary housing can be accomplished by spin welding closed the accumulator housing as taught by U.S. Pat. No. 4,675,971 to Masserang. In known accumulator assemblies and methods of making same, the desiccant material is added to the housing prior to welding and leak testing the accumulator assembly. This known method introduces the risk of saturating the desiccant, and results in a high scrap rate and material cost for damage the desiccant bag incurs during brazing and testing operations. In addition, with known devices and methods of making these devices, field repair and rework are not practical. Repairs consist of removing the defective device and replacing the entire accumulator or receiver unit. There are accumulators for air-conditioning systems which sealingly connect a separate desiccant container in the bottom of the accumulator housing prior to permanently assembling the accumulator. The desiccant remains serviceable through the bottom of the housing. This system is disclosed in U.S. Pat. Nos. 4,276,756 and 4,291,548 to Livesay. The Livesay references disclose an access opening in the bottom of the housing that opens into the interior of a desiccant container. A separate, empty desiccant container is placed inside the accumulator housing. A U-shaped tube is placed inside the housing. The empty desiccant container is received in the bight portion of the U-shaped tube. The desiccant container has an open lower end that communicates with the opening in the bottom of the housing. An annular seal attachment sealingly attaches the lower end of the desiccant container through the open lower end thereof. A detachable closure cooperates with the closure fitting to close the access opening in the housing. The desiccant container is filled after the housing has been permanently assembled by inverting the container and gravity feeding desiccant material. U.S. Pat. No. 4,291,548 discloses a desiccant container that is a foldable bag that can be inserted through the opening in the bottom of the housing. U.S. Pat. No. 4,838,040 to Freeman discloses a receiver dryer in which the housing has a readily openable lid held in place by quick disconnect clamps. The lid can be removed to allow a desiccant canister to be inserted inside the housing. To ensure adequate sealing, the housing has an annular O-ring. The separate lid has an overhang that seals against the O-ring of the housing. Additionally, the lid has an internally depending sleeve segment that is provided with another O-ring. The two O-rings are necessary to completely seal the housing against leakage. The lid is secured in place by a quick disconnect clamping band. Accumulators must maintain high standards during testing. Therefore, a one-piece or unitary design is desired for the housing. The number of access openings and weld joints should be kept to a minimum for the housing to withstand the demanding impact, leak and burst test requirements. A drawback associated with prior art arrangements that provide access to the desiccant material is the need for a separate access opening. Additional openings disrupt the integrity of the accumulator or receiver dryer housing. Any opening in the housing introduces the potential for leaks, so a minimum number of openings is desirable. A leak proof housing can be manufactured by spin welding a unitary housing into a closed configuration. Therefore, the number of components and attachments inside the accumulator housing should be kept to a minimum to reduce the risk of components breaking loose during the spin weld process. The accumulator disclosed in Livesay and the receiver dryer disclosed in Freeman require several additional components to accomplish accessibility to the desiccant material making spin welding impractical. In addition, if the devices disclosed by Livesay or Freeman cannot be closed by spin welding without defeating their innovative design feature of a separate opening to provide access to the desiccant. In Livesay, not only is an additional opening required, but a separate desiccant container to hold the desiccant material is necessary. A sealing attachment between the container and the housing is necessary to maintain the desiccant container's position within the housing, and a closure member is necessary to prevent desiccant material from escaping the container. The receiver dryer disclosed by Freeman also requires significant additional structure. A separate lid, two O-rings, a clamping band and a separate desiccant container are all necessary additional components for access to the desiccant material. Additionally, the sealing attachment between the desiccant container and the casing disclosed by Freeman must be extremely reliable to avoid desiccant material from escaping the desiccant container and contaminating the interior of the casing. The location of the desiccant within the housing is an important aspect of an accumulator design. Ideally, the desiccant is located near the top of the housing. Locating the desiccant near the top of the housing ensures all vapor components of the refrigerant pass through the desiccant thereby improving the accumulator's performance. In operation, the liquid refrigerant settles in the bottom of the accumulator housing. Positioning the desiccant in the bottom of the housing introduces the risk of saturating the desiccant material. In addition, all of the vapor inside the accumulator housing is not forced through the desiccant. The vapor that remains near the top of the housing never reaches the desiccant material and may contain unwanted moisture as a result. The Livesay references disclose locating the desiccant in the bottom of the housing, which is not desirable for optimum accumulator performance. What is needed is an accumulator housing that can be accessed for inserting or removing desiccant material, having a minimum of components and without separate access openings that compromise the integrity of the housing. SUMMARY OF THE INVENTION The present invention embodies a housing that can be brazed and leak tested before the desiccant is added, eliminating the risk of damaging desiccant bags during assembly. A loose desiccant material is added directly to the housing of the present invention through an existing inlet opening in the top of the accumulator housing. The loose desiccant material can be added after the accumulator is completely assembled and tested. The potential for damage to the desiccant and the desiccant container are completely eliminated. The integrity of the housing is not compromised as no additional openings in the housing are required to access the desiccant material. The desiccant material is ideally located in the top portion of the housing. The present invention employs a screen permanently mounted inside the pressure vessel that supports the loose desiccant material. Another screen, removably attached to the inlet opening, provides access to the loose desiccant material housed within the pressure vessel. A method of making the present invention allows the accumulator assembly to be leak tested before the desiccant is added. This reduces scrap and allows repair of accumulator assemblies. The method includes spin welding closed a cylindrical tube; attaching an inlet tube to the closed end of the cylindrical tube; assembling an outlet tube, baffle member, and baffle screen; inserting the outlet tube assembly inside the cylindrical tube; attaching the outlet tube to the closed end of the cylindrical tube; spin closing the remaining open end of the cylindrical tube; adding loose desiccant through the inlet tube; and inserting a removable screen to the inlet opening. In one embodiment, the baffle screen is made of a thermoplastic material. The baffle screen is thermally bonded to the vessel's housing by centrifugal force and heat generated during the spin welding process. The removable inlet screen facilitates field repair and rework of the accumulator assembly. It is not necessary to replace the entire accumulator assembly merely because the desiccant material needs to be replaced. The inlet screen can be removed, the accumulator can be emptied of old desiccant material, new material can be added through the inlet opening, and the screen replaced. It is an object of the present invention to add loose desiccant material to the housing after assembly, brazing, and leak testing of the housing. It is another object of the present invention to provide access to the desiccant material without jeopardizing the integrity of the housing. It is yet another object of the present invention to provide access to the desiccant material without removing the housing from the overall air-conditioning system, enabling field repair. It is a further object of the present invention to position the desiccant material in the top of the housing to ensure adequate drying of refrigerant vapor. These objects, features, and advantages of the present invention will become readily apparent from the following detailed description of the preferred embodiment when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view shown in partial cross section of a prior art accumulator; FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1; FIG. 3 is a side view shown in partial cross section of an accumulator of the present invention; and FIG. 4 is a cross-sectional view taken along line IV--IV of FIG. 3 showing the detail of the baffle screen and inlet screen of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is a schematic of a generally conventional vehicular air-conditioning accumulator 100. The structure of the prior art accumulator 100 includes a cylindrical tubular housing 110 that is closed at both ends. Typically, the housing 110 is closed by a spin welding process being conventional in the art as taught, for example, by U.S. Pat. No. 4,675,971 to Masserang, or mig welding a center joint as known by one skilled in the art. The prior art accumulator 100 includes an inlet opening 120 and an outlet opening 140 in the top of the accumulator housing 110 providing access to the interior of the housing 110. An inlet tube 130 is brazed or welded to the inlet opening 120 of the accumulator housing 110. An outlet tube 150 is included which receives additional structure efore it is permanently affixed to the outlet opening 140 of the accumulator housing 110. Typically, the outlet tube 150 has a U-shaped configuration. A bight portion 155 of the outlet tube 150 is located in the lower region of the accumulator housing 110. A first leg 151 of the outlet tube 150 supports a baffle 160, or deflector plate, which is permanently fixed to the outlet tube 150 by brazing or welding. A second leg 152 of the outlet tube 150 is shorter than its first leg 151, and its end located underneath the baffle 160. The outlet tube assembly is welded or brazed to the accumulator housing 110 at the outlet opening 140 in the top of the accumulator housing 110. A desiccant bag 170, or other container holding a desiccant material 180, is attached to the outlet tube 150 prior to the outlet tube 150 being permanently attached to the top of the accumulator housing 110. Usually the desiccant bag 170 is supported in the bight portion 155 of the outlet tube 150. The baffle 160 is permanently affixed to the interior walls of the accumulator housing 110. Usually, this is done by tack welding the baffle 160 to the interior of the housing 110 at several locations around the perimeter of the baffle 160, or by an interference fit between tabs 161 on the outer periphery of the baffle 160 and the interior walls of the accumulator housing 110. It is critical for proper operation of the accumulator that the desiccant bag 170 or container is not damaged while permanently attaching the baffle 160 to the housing 110, yet it is a common occurrence which cannot be detected until after the impact and burst tests are completed. If a damaged desiccant bag is discovered, the entire accumulator 100 is scrapped, which is costly. The outlet tube 150 is permanently attached to the accumulator housing 110. Typically it is brazed or welded. The brazing process used to attach the baffle 160 and outlet tube 150 introduces significant risks to the desiccant material 180. The desiccant 180 can be damaged by the heat generated by the welding or brazing process. The remaining open end of the accumulator 100 is closed. After the accumulator 100 is fully assembled, the unit is tested. Any failures at this stage usually result in irreparable damage to the desiccant bag 170 and the entire unit 100 must be scrapped because there is no way to access the interior of the accumulator housing 110. Repair and rework are not options using this method of manufacture. The structure of prior art accumulators 100 is not consistent with accessing the desiccant material 180 without destroying the integrity of the accumulator housing 110. FIG. 3 is an accumulator 200 of the present invention that is similar to prior art accumulators except for the elimination of a separate desiccant bag 170 or container and the relocation of the desiccant material within the accumulator. Like components of the prior art accumulator of FIGS. 1 and 2 are labeled with the same reference numerals increased to 200. The present invention allows a method of manufacture that eliminates the need for a separate desiccant bag 170, thereby eliminating the risk of damage thereto and costly scrap of to the complete accumulator assembly. Additionally, the accumulator 200 of the present invention allows access to the desiccant material 280 without affecting the integrity of the accumulator housing 210. The majority of components of the accumulator 200 of the present invention are the same as those of prior art accumulators 100. The housing 210 is spun weld closed as in prior art accumulators 100. The inlet tube 230 configuration is the same as prior art accumulators 100. The shape and positioning of the outlet tube 250 is also the same as prior art accumulators. The baffle 260 shape and position of the baffle 260 are also the same as in prior art accumulators 100. The accumulator 200 of the present invention is modified from prior art accumulators 100 by including a screen 290 positioned between the periphery of the baffle 260 and the interior wall of the housing 210. While the shape, position and attachment of the baffle 260 to the outlet tube 250 is the same as prior art accumulators, the present invention includes the baffle screen 290 that surrounds the periphery of the baffle or deflector plate 260. The baffle screen 290 effectively separates the interior of the housing 210 into an upper chamber 211 and a lower chamber 212. The baffle screen 290 supports loose desiccant material, and therefore must have pores 292 which are small enough to prevent any desiccant material 280 from escaping into the lower chamber 212 of the housing 210. The pores 292 are large enough so as not to interfere with the flow of refrigerant fluid into the lower chamber 212 of the housing 210. The baffle screen 290 can be attached to the outer periphery of the baffle 260 by any means sufficient to permanently affix the baffle screen 290 to the baffle 260. Some of the methods will be discussed in detail below. It is imperative that loose desiccant material 280 not escape into the lower chamber 212 of the housing 210. The baffle screen 290 must be attached to the inner wall of the housing 210. The same method used to attach the baffle screen 290 to the baffle 260 could be employed to attach the baffle screen 2902 to the interior wall of the housing 210. The periphery of the baffle screen 290 must be completely sealed against the interior wall of the housing 210, as it is sealed to the periphery of the baffle 260, to prevent any loose desiccant material 280 from escaping. In one embodiment of the present invention, the baffle screen 290 is initially temporarily fastened to the interior of the housing 210 by an interference fit, or tack welding. The baffle screen 290 is permanently bonded to the interior of the housing by heat generated during the welding process used to close the housing 210. The baffle screen 290 can be made of a thermoplastic or a material containing sintered thermoplastic pellets. Under centrifugal force and heat generated during the welding process, the thermoplastic material of the baffle screen 290 bonds to the interior of the housing 210. The baffle screen 290 and baffle 260 combination divide the interior of the housing 210 into the upper and lower chambers 211 and 212. The baffle screen 290 effectively supports the loose desiccant material 280 and prevents it from escaping into the lower chamber 212 of the housing 210. The baffle screen 290 neither prohibits nor interferes with the flow of refrigerant from the upper chamber 211 into the lower chamber 212 of the housing 210. The inlet tube 230 is permanently affixed to the inlet opening 220 in the top of the accumulator housing 210 just as in prior art accumulators 100. However, the present invention includes an inlet screen 221 that covers the inner diameter of the inlet opening 220. The purpose of the inlet screen 221 is the same as that of the baffle screen 290 surrounding the baffle 260. The inlet screen 221 does not prohibit free flow of refrigerant, yet the loose desiccant material 280 is prevented from escaping the interior of the accumulator housing. The inlet screen 221 covering the inner diameter of the inlet opening 220 need not be permanently affixed, and it is in fact desirable to maintain the removability of this screen 221 by mounting the inlet screen 221 against a shoulder on the inlet tube or in any convenient manner providing the inlet screen 221 is removable after installing same in the inlet tube 230. The inlet screen 221 can be removed for emptying and refilling the upper chamber 211 of the housing, facilitating field repair and rework. Finally, as mentioned above, loose desiccant material 280 is located in the upper chamber 212 of the accumulator housing 210. The loose desiccant material 280 is prevented from entering the lower chamber 212 of the accumulator housing 210 by the baffle 260 and the baffle screen 290. Likewise, the inlet screen 221 prevents the loose desiccant material 280 from escaping through the inlet opening 220. The accumulator 200 of the present invention includes introducing loose desiccant material 280 through the inlet opening 220 of the accumulator 200. Once the desiccant material 280 is added, the inlet screen 221 is placed over the inner diameter of the inlet opening 220. One advantage of the present invention is readily apparent. The desiccant material 280 need not be added to the assembly until after the accumulator 200 is completely assembled and pressure and leak tested. This eliminates unnecessary handling of the desiccant material 280, and eliminates potential harm to the desiccant material 280 during the assembly and testing process. Additionally, the entire accumulator assembly 200, minus the desiccant material 280, can be leak, impulse and proof tested, repaired, reworked, and retested before any desiccant material 280 is added. The ability to repair and rework units saves scrapping a fully assembled unit lowering manufacturing costs. Another advantage is that the desiccant material 280 can be accessed in the field. It is now possible to perform field repairs and maintenance procedures that were not possible before. It is no longer necessary to replace accumulators 200 that could not be repaired simply because of inaccessibility to the desiccant material 280. The following steps are included in the method of making an accumulator 200 of the present invention; closing one end of the housing, such as by welding as taught in U.S. Pat. No. 4,675,971, or another welding process known by one of ordinary skill in the art; drilling inlet and outlet openings in the closed end of the housing to the same size as the outer diameter of the inlet and outlet tubes; inserting the inlet tube into the inlet opening and brazing the tube to the top end wall of the housing; axially inserting the baffle over a leg of the outlet tube and fastening the baffle thereto; temporarily fastening the baffle screen around the outer periphery of the baffle by a mechanical fastener; inserting the outlet tube, baffle, and baffle screen through the open end of the accumulator housing; brazing the outlet tube to the housing; fastening, by brazing or otherwise, the baffle to the interior wall of the housing; temporarily fastening the baffle screen to the interior wall of the housing by means of mechanical fasteners; closing the remaining open end of the accumulator housing, by spin welding to generate enough heat to thermally and centrifugally bond the baffle screen to both the baffle and the interior wall of the housing; introducing loose desiccant material through the inlet tube into the upper chamber of the outlet housing; and removably fastening an inlet screen within the inner diameter of the inlet tube over the inlet opening of the accumulator housing. While the preferred embodiment of the present invention is to thermally bond the baffle screen to the interior of the housing, any alternative method of attachment may also be employed to obtain the same results, such as welding or adhesive bonding. Although a particular embodiment of the present invention has been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present invention is not to be limited to just the embodiments disclosed. For example, the baffle screen could be adhesively bonded to the baffle and interior wall of the accumulator housing and the remaining end of the housing closed by means other than spin welding. Another example involves relying on the permanent bond between the interior wall of the housing, the baffle screen and the baffle to maintain the baffle's position within the accumulator housing and eliminating the step of fastening the baffle to the outlet tube. Numerous rearrangements, modifications and substitutions are possible, without departing from the scope of the claims hereafter.

A pressure vessel housing that can be brazed and leak tested before adding desiccant material, eliminating the risk of damaging desiccant bags during assembly. The desiccant is added to the housing of the pressure vessel through an existing inlet opening in the top of the accumulator housing, thereby eliminating the potential for damage to the desiccant and the desiccant container while maintaining the integrity of the housing because no additional openings in the housing are required to access the desiccant material. A screen permanently mounted inside the pressure vessel supports the loose desiccant material and another screen removably attached to the inlet opening provides access to the loose desiccant material housed within the pressure vessel. A method of making the pressure vessel allows the accumulator assembly to be leak tested before the desiccant is added, reducing scrap and allowing repair of accumulator assemblies.

RELATED APPLICATION DATA The present application is related to commonly-assigned U.S. Pat. No. 7,876,516, entitled REWRITE-EFFICIENT ECC/INTERLEAVING FOR MULTI-TRACK RECORDING ON MAGNETIC TAPE, and commonly-assigned and co-pending U.S. application Ser. No. 12/351,756, entitled REWRITING CODEWORD OBJECTS TO MAGNETIC DATA TAPE UPON DETECTION OF AN ERROR, both filed on the same date as the present application, and both of which are hereby incorporated herein by reference in their entireties. TECHNICAL FIELD The present invention relates generally to formatting data to be recorded onto magnetic tape and, in particular, to an adjustable ECC format and interleaving process to accommodate tape drives having a multiple of eight transducers/sensors per head to read and write from/to a multiple of eight number of tracks simultaneously. BACKGROUND ART The Linear Tape Open (LTO) formats Generations 3 and 4 use error-correcting codes (ECC), which are based on a 2-dimensional product code. The C1-code is arranged along the rows of the 2-dimensional array. It is an even/odd interleaved Reed-Solomon (RS) code of length 240 giving rise to a row of length 480. The C2-code is arranged along the columns of the array. It is a RS-code of length 64 and dimension 54. The codewords are 2-dimensional arrays of size 64×480 and they are called subdata sets in the LTO standard. It is anticipated that future generation of drives will write on more than 16 tracks simultaneously. However, all current generations of LTO formats (Gen-1 to Gen-4) are based on the above C2 coding scheme which, together with its associated interleaving, cannot accommodate future tape-drive systems that will support heads with 16, 24, 32 or 48 (or other multiple of eight) transducers/sensors per head to read/write 16, 24, 32 or 48 (or other multiple of eight) concurrent tracks, respectively. SUMMARY OF THE INVENTION The present invention provides higher-rate and longer C2 codes, which do not degrade error rate performance. The code rate associated with these C2 codes is greater than the LTO-3/4 C2 code rate 54/64 and the codeword length is greater than the LTO-3/4 C2 codeword length 64. In particular, the present invention provides a C2 code with rate K 2 /N 2 =84/96 and codeword length N 2 =96 and a corresponding encoder. More specifically, the present invention provides methods, apparatus and computer program product for writing data to multi-track tape. In one embodiment, a method comprises receiving a stream of user data symbols, the stream comprising a data set and segmenting the data set into a plurality S of unencoded subdata sets, each subdata set comprising an array having K2 rows and K1 columns. For each unencoded subdata set, N1−K1 C1-parity bytes are generated for each row of a subdata set which are appended to the end of the row to form an encoded C1 codeword having a length N1. Similarly, for each unencoded subdata set, N2−K2 C2-parity bytes are generated for each column of the subdata set which are appended to the end of the column to form an encoded C2 codeword having a length N2, whereby an encoded subdata set is generated having N2 C1 codewords. From the S encoded data subsets, a plurality (S×N2)/2 codeword objects (COs) are formed, each comprising a first header, a first C1 codeword, a second header and a second C1 codeword. Each CO is mapped onto a logical data track according to information within the headers of the CO and modulation encoded into synchronized COs that contain various sync patterns in addition to modulation encoded COs. T synchronized COs are then written simultaneously to the tape, where T equals the number of concurrent active tracks on the tape. In another embodiment, a data storage tape device comprises a host interface through which a stream of user data symbols comprising a data set is received and a segmenting module operable to segment the data set into a plurality S of unencoded subdata sets, each subdata set comprising an array having K2 rows and K1 columns. A C1 encoder is operable to generate N1−K1 C1 parity bytes for each row of a subdata set and append the C1 parity bytes to the end of the row to form an encoded C1 codeword having a length N1 and a C2 encoder is operable to generate N2−K2 C2 parity bytes for each column of the subdata set and append the C2 parity bytes to the end of the column to form an encoded C2 codeword having a length N2, whereby an encoded subdata set is generated having N2 C1 codewords. A codeword object formatter is operable to form a plurality (S×N2)/2 codeword objects (COs) from the S encoded data subsets, each CO comprising a first header, a first C1 codeword, a second header and a second C1 codeword. A codeword object interleaver is operable to map each CO onto a logical data track according to information within the headers of the CO. A modulation encoder is operable to encode the COs into synchronized COs that contain various sync patterns in addition to modulation encoded COs. A write channel, including a write head, is operable to write T synchronized COs simultaneously to the tape, where T equals the number of concurrent active tracks on the tape. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a magnetic tape drive with which the present invention may be implemented; FIG. 2 is a schematic representation of an encoded data set, including interleaved C1 and C2 ECC; FIG. 3 is a block diagram of components of the present invention used to form data sets from a stream of user data symbols; FIGS. 4A and 4B are schematic representations of unencoded and encoded subdata sets, respectively; FIG. 5 illustrates a codeword object (CO) of the present invention; FIG. 6 is a logic diagram of a C2-encoder of the present invention for a [96, 84, 13]-RS code; FIG. 7 illustrates an alternative CO of the present invention; FIG. 8 illustrates an example of a distribution of subdata sets along 24 tracks of recording media in accordance with the present invention; FIG. 9 illustrates a synchronized CO of the present invention; and FIG. 10 illustrates an alternative synchronized CO of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Some of the functional units described in this specification have been labeled as modules in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. A module of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs and across several memory devices. Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, hardware modules, hardware circuits, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. FIG. 1 is a high level block diagram of a data tape drive 100 in which the present invention may be incorporated. Data to be recorded is transmitted from a host (not shown) to the drive 100 through a host interface 102 . The data undergoes a first encoding in a C1 encoder 104 and passed to a DRAM buffer controller 106 . The C1-encoded data undergoes a second encoding in a C2 encoder 108 and is stored in a DRAM buffer 110 . The data is subsequently stored in an SRAM buffer 112 and formatted in a formatter 114 . Formatted data is sent to a write channel and then to a write head 118 which records the data onto the tape 120 . When the data is read back from the tape 120 , a read head 122 detects the data and passes it to a read channel. The data is then processed in a de-formatter 126 and COs are verified in a verifier 128 . The data is then decoded and, ultimately, sent to the requesting host. The Linear Tape Open (LTO) format is based on the concept of data sets (the smallest unit written to tape) and subdata sets. A data set contains two types of data: user data and administrative information about the data set, the latter being in a Data Set Information Table (DSIT). All data is protected by an error correction code (ECC) to minimize data loss due to errors or defects. A data set comprises a number of subdata sets, each containing data arranged in rows. A subdata set row may contain user data or contain the DSIT. As illustrated in FIG. 2 , each row consists of two interleaved byte sequences. A first level ECC (C1 ECC) is computed separately for the even bytes and for the odd bytes for each row. The resulting C1 ECC even and odd parity bytes are appended to the corresponding row, also in an interleaved fashion. The ECC protected row is the Codeword Pair (CWP). The even bytes form the even C1 Codeword while the odd bytes form the odd C1 Codeword. A second level ECC (C2 ECC) is computed for each column and the resulting C2 ECC parity bytes are appended to the corresponding columns. The ECC protected column is a C2 Codeword. The subdata set, when so protected by C1 and C2 ECC, is the smallest ECC-protected unit written to tape. Each subdata set is independent with respect to ECC; that is, errors in a subdata set affect only that subdata set. The power of any ECC algorithm depends upon the number of parity bytes and is stated in terms of its correction capability. For a given number of N1−K1 C1-parity bytes computed for a C1 codeword, up to floor((N1−K1)/4) errors may be corrected in each of the two interleaves of that codeword, where floor(x) denotes the integer part of the real number x. And, for a given number of N2−K2 C2-parity bytes computed for a C2 codeword, up to floor((N2−K2)/2) errors or N2−K2 erasures may be corrected in that C2 Codeword. It will be appreciated that multiple errors in the same subdata set can overwhelm the ability of the C1 or the C2 correction power to the extent that an error occurs when the data is read. Errors may be caused by very small events such as small particles or small media defects. Errors may also be caused by larger events such as scratches, tracking errors or mechanical causes. To mitigate the possibility that a single large error will affect multiple Codewords in a single subdata set, some methods of writing place Codewords from each subdata set as far apart as possible along and across the tape surface. A single error would therefore have to affect multiple Codewords from the same subdata set before the ECC correction capability is overwhelmed. Spatial separation of Codewords from the same subdata set reduces the risk and is accomplished in the following manner for a multi-track recording format. For each track of a set of tracks being recorded simultaneously, a Codeword Quad (CQ) is formed by combining a Codeword Pair from one subdata set with a Codeword Pair from a different subdata set. The resulting CQ is written on one of the multiple recorded tracks. In like manner, CQs are formed for all remaining tracks by combining Codeword Pairs, all Codeword Pairs being from differing subdata sets. The group of CQs written simultaneously is called a CQ Set. As illustrated in the block diagram of FIG. 3 , data sets of a specified fixed size are formed by segmentation of a stream of user data symbols in a data set segmentation module 302 . The data set is further partitioned into S unencoded subdata sets. The subdata set structure is matched to an ECC module 304 , which is based on a C1/C2 product code. The unencoded subdata sets comprise 2-dimensional arrays of bytes of size K 2 ×K 1 , where K 1 and K 2 are the dimensions of the C1 and C2 code, respectively ( FIG. 4A ). A C1-encoder 306 operates on rows and adds parity bytes in each row. A C2-encoder 308 operates on the C1-encoded columns and appends parity in each column. The resulting C1/C2-encoded subdata set is an N 2 ×N 1 array of bytes, where N 1 and N 2 are the lengths of the C1 and C2 code, respectively ( FIG. 4B ). It will be appreciated that, although in FIG. 3 and in FIG. 4 the C1 encoding is shown as being performed first followed by the C2 encoding, the resulting encoded subdata sets are the same regardless of whether C1 encoding is performed first followed by C2 encoding or whether C2 encoding is performed first followed by C1 encoding. In LTO-3/4, S=64 subdata sets (or codewords) form a data set (DS), the C1 code has length N 1 =480 and the C2 code has length N 2 =64. The C1-codewords within a DS are fully determined by the subdata set (SDS) number (in the range from 0 to S−1) and by the row number within the subdata set (codeword array). In LTO-3/4, this assignment is called codeword pair designation. It is determined by the following expression: C 1-codeword_number=SDS_number+64×row_number, where SDS_number=0, 1, 2, . . . , S−1 and row_number=0, 1, . . . , 63. For LTO-3/4, the C1-codeword_number index takes values from 0 to 4095. A structure 500 as shown in FIG. 5 is a Codeword Object (CO) structure and reflects the organization of the basic unit that includes C1-codewords and associated headers. From the ECC module 304 , a CO formatter 310 forms COs consisting of two 10-byte headers 502 , 504 and of two C1-codewords 506 , 508 out of the S×N 2 =4096 C1-codewords per DS. Thus, there are S×N 2 /2=2048 COs, which are numbered from 0 to 2047. The CO structure 500 with index CO_number contains the two C1-codewords with indices C1-codeword_number that are related as follows. The indices C1-codeword_number_ 0 and C1-codeword_number_ 1 of the first and second C1-codewords, respectively, are given by C 1-codeword_number — 0=2×CO_number C 1-codeword_number — 1=2×CO_number+1. According to a first embodiment of the present invention, the C2-code generated by the C2 encoder 308 is a Reed-Solomon (RS) code of length N 2 =96 over the Galois field GF(256). The Galois field GF(2 8 ) is defined by the primitive polynomial P(z)=z 8 +z 4 +z 3 +z 2 +1 and the primitive element in GF(2 8 )=GF(2)[z]/(z 8 +z 4 +z 3 +z 2 +1) is: α=(0 0 0 0 0 0 1 0)= z (modulo z 8 +z 4 +z 3 +z 2 +1). Note that α 255 =1. The generator polynomials for the C2-codes are chosen to have as few different coefficients as possible, which helps reduce the complexity of encoders and decoders. In particular, the generator polynomial for the [N 2 =96, K 2 =84, d min =13] RS-code is given by: G ⁡ ( x ) = ⁢ ∏ i = 1 , ⁢ … ⁢ , 6 ⁢ ⁢ ( x + α 128 - i ) ⁢ ( x + α 127 + i ) = ⁢ ∏ i = 1 , ⁢ … ⁢ , 6 ⁢ ⁢ ( x 2 + ( α 128 - i + α 127 - i ) ⁢ x + 1 ) = ⁢ x 12 + α 224 ⁢ x 11 + α 32 ⁢ x 10 + α 209 ⁢ x 9 + α 99 ⁢ x 8 + α 32 ⁢ x 7 + ⁢ α 80 ⁢ x 6 + α 32 ⁢ x 5 + α 99 ⁢ x 4 + α 209 ⁢ x 3 + α 32 ⁢ x 2 + α 224 ⁢ x + 1. The encoding by the C2 encoder 308 is performed by a linear feedback shift register (LFSR) 600 as shown in FIG. 6 . In the example illustrated, the LFSR 600 includes 12 registers R 0 to R 11 ( 602 A- 602 L) and 11 multipliers 604 A- 604 K whose feedback coefficients α c are given by the generator polynomial of the [96,84,13]-RS code. The initial state of the LFSR 600 is the all-zero state. The N 2 −K 2 =12 parity bytes of an RS codeword are obtained by clocking all the systematic K 2 =84 data bytes through the LFSR, multiplying them in the respective multipliers 604 A- 604 L, adding 606 A- 606 K the results to the respective register outputs and reading out registers R 0 to R 11 ( 602 A- 602 L). In an actual implementation, the number of multipliers may be reduced by “reusing” multipliers whose coefficients are duplicated. For example, although illustrated as separate multipliers, multipliers 604 A and 604 K, having the common coefficient α 224 , may be implemented as a single multiplier, multipliers 604 B, 604 E, 604 G and 604 J, having the common coefficient α 32 , may be implemented as a single multiplier, etc. Thus, the LFSR 600 may be more efficiently implemented with five multipliers instead of 11. Moreover, the number n of registers, the number n of adders and the number n−1 of multipliers may be greater than or less than the numbers illustrated in FIG. 6 to accommodate different codes. Additional generator polynomials may also be defined. A generator polynomial for a [128,112,17] code is given by: G ⁡ ( x ) = ⁢ ∏ i = 1 , ⁢ … ⁢ , 8 ⁢ ⁢ ( x + α 128 - i ) ⁢ ( x + α 127 + i ) = ⁢ x 16 + α 240 ⁢ x 15 + α 892 ⁢ x 14 + α 212 ⁢ x 13 + α 79 ⁢ x 12 + α 192 ⁢ x 11 + ⁢ α 116 ⁢ x 10 + α 151 ⁢ x 9 + α 198 ⁢ x 8 + α 151 ⁢ x 7 + α 116 ⁢ x 6 + α 192 ⁢ x 5 + ⁢ α 79 ⁢ x 4 + α 212 ⁢ x 3 + α 89 ⁢ x 2 + α 240 ⁢ x + 1. And, a generator polynomial for a [192,168,25] RS code is given by: G ⁡ ( x ) = ⁢ ∏ i = 1 , ⁢ … ⁢ , 12 ⁢ ⁢ ( x + α 128 - i ) ⁢ ( x + α 127 + i ) = ⁢ x 24 + α 90 ⁢ x 23 + α 98 ⁢ x 22 + α 228 ⁢ x 21 + α 2 ⁢ x 20 + α 26 ⁢ x 19 + ⁢ α 48 ⁢ x 18 + α 43 ⁢ x 17 + α 34 ⁢ x 16 + α 183 ⁢ x 15 + α 65 ⁢ x 14 + α 170 ⁢ x 13 + ⁢ α 24 ⁢ x 12 + α 170 ⁢ x 11 + α 65 ⁢ x 10 + α 183 ⁢ x 9 + α 34 ⁢ x 8 + α 43 ⁢ x 7 + ⁢ α 48 ⁢ x 6 + α 26 ⁢ x 5 ++ ⁢ α 65 ⁢ x 10 + α 2 ⁢ x 4 + α 228 ⁢ x 3 + α 98 ⁢ x 2 + ⁢ α 90 ⁢ x + 1. It is assumed that the C1-codewords are pre-defined and, thus, their length N 1 is given. That is, the C1-code may be a 2-way interleaved RS-code of length 480 as in LTO-4, as illustrated in FIG. 5 , or may be a 4-way interleaved RS-code of length 960 , as illustrated in FIG. 7 . The format of the present invention includes subdata sets, which are arrays of dimension N 2 ×N 1 , where N 2 =96, and a predetermined number S of subdata sets forms a data set. The codeword number is determined by the expression: C 1-codeword_number=SDS_number+S×row_number, where SDS_number=0, 1, 2 , . . . , S -1 and row_number=0, 1 , . . . , N 2 −1. The CO structures are mapped onto the logical tracks (16 for LTO-3/4) according to the information in the header, viz., C1-codeword_number index. This mapping will be referred to as CO-interleaving and is performed in a CO interleaver 312 ( FIG. 3 ). In LTO-4, the CO structures is referred to as a codeword quad because it consists of four RS codewords. In this case, there are S=64 subdata sets per DS. An alternative CO structure is shown in FIG. 7 , where one C1-codeword consists of a 4-way interleaved RS-code. This CO structure is referred to as a codeword octet. In this case, the DS is partitioned into S=32 subdata sets. Again, each CO consists of two 10-byte headers and two C1-codewords out of the S×N 2 C1-codewords per DS and, thus, there are S×N 2 /2 COs, which are numbered in consecutive order starting from 0. The CO structure with index CO_number contains the two C1-codewords with indices C1-codeword_number that are related as follows. The indices C1-codeword_number_ 0 and C1-codeword_number_ 1 of the first and second C1-codewords, respectively, are given by: C 1-codeword_number — 0=2×CO_number C 1-codeword_number — 1=2×CO_number+1. Therefore, two C1-codewords in an CO are taken from two SDSs with consecutive SDS_number indices. The COs are written simultaneously onto the tape in batches of T COs, where T is the number of concurrent active tracks. The CO-interleaver 312 assigns a logical track number t in the range 0, 1, . . . , T−1 to each CO of the DS. Thus, the S×N 2 /2 COs of a DS are grouped into batches of T COs based on their consecutive CO_number indices and then these batches are written onto the T active tracks. Thereby, one CO of each batch is written onto one of the T tracks in a one-to-one fashion, which is determined by the CO-interleaver 312 . More specifically, the CO-interleaver 312 maps a CO structure with index n=CO_number to logical track number t based on the formula: t≡ 5 floor(2 n/S )+ n (mod T )  [Expression 1] where floor(x) denotes the integer part of the real number x and (mod T) denotes the modulo operation with modulus T in which the remainder is in the range 0, 1, . . . , T−1. For N 2 =96, one can accommodate T=16, 24, 32, 48 or 96 parallel tracks. In FIG. 8 , the result of the CO-interleaving is illustrated for a DS with S=96 SDSs by showing the data set layout of two pairs of SDSs along T=24 tracks. The 96 dots correspond to the 96 COs of the SDSs with SDS_number 0 and 1 ; the 96 crosses correspond to the 96 COs of the SDSs with SDS_number 2 and 3 . It can be seen that the 96 C1-codewords within a SDS are uniformly distributed along and across the T=24 tracks. The approach described in the embodiment described above is general and may be applied also to C2-codes of length N 2 =128 and N 2 =192. In both cases, the CO-interleaving Expression 1 is valid. For N 2 =128, one can accommodate T=16, 32, 64 or 128 parallel tracks and, for N 2 =192, there can be T=16, 24, 32, 48, 64, 96, or 192 tracks. When designing a C2-code of the present invention, a determination would first be made of the number of possible parallel tracks T 1 , T 2 , . . . , T m to which COs are to be written. N 2 may then be calculated as the least common multiple of numbers T 1 , T 2 , . . . , T m . For example, if it is desired to accommodate T=16, 24, 32, 48 or 96 parallel tracks, the least common multiplier is N 2 =96. Similarly, if it is desired to accommodate T=16, 32, 64 or 128 parallel tracks, the least common multiplier is N 2 =128. And, if it is desired to accommodate T=T=16, 24, 32, 48, 64, 96, or 192 parallel tracks, the least common multiplier is N 2 =192. It will be appreciated that the foregoing are provided as examples and that the present invention is not limited to any particular value of N 2 or to any particular number T of parallel tracks to which the COs are to be written. After CO-interleaving and before writing them onto tape, the COs are modulation encoded and transformed into synchronized codeword object (SCO) structures by inserting VFO, forward, resync and reverse sync fields. FIGS. 9 and 10 illustrate alternative COs. In LTO-4, the headers and codeword pairs are passed through a rate-16/17 RLL encoder resulting in RLL-encoded bit-sequences of length 85 and 4080 , respectively. More generally, the CO structures can be modulation encoded using an RLL-encoder of rate R H for the header portion and an RLL-encoder of rate R for the C1-codewords ( FIG. 9 ). For the alternative CO structure of FIG. 7 , the resulting SCO-structure is illustrated in FIG. 10 , where the VFO, forward sync, re-sync and reverse sync fields have some suitable lengths L VFO , L FS , L RS , and L FS , respectively. The proposed interleaving scheme is designed to provide robustness against dead tracks and have an increased robustness against stripe errors (that is, errors across all tracks). The robustness of an ECC/CO-interleaving scheme against stripe errors depends on three factors: (i) the parameters [N 2 , K 2 , d min ] of the C2-code, (ii) the interleaving depth given by the number S of subdata sets (SDS) within each Data Set (DS), and (iii) the number T of parallel channels (tracks). In case of a stripe error, the decoder operates as follows. The C1-decoder detects that certain rows in a number of subdata sets are uncorrectable and provides erasure-flags of these rows to the C2-decoder. The C2-decoder performs erasure-decoding and can correct up to N 2 −K 2 −M erasures per subdata set while keeping a margin of M bytes to avoid miscorrections. If a stripe error along tape extends over no more than (S/2)×(N 2 −K 2 −M)/T SCOs, then there are no more than (S/2)×(N 2 −K 2 −M) COs which are affected by errors and these erroneous COs are evenly distributed by the inverse CO-interleaving map over the S/2 pairs of subdata sets of an affected DS. Thus, each subdata set will contain at most N 2 −K 2 −M erased rows, which can be corrected and, therefore, the maximum stripe error length (MSEL) in terms of SCO units is given by: MSEL= S ×( N 2 −K 2 −M )/(2 T ). The absolute length of the MSEL along the tape in [mm] depends on the length of the SCO in [mm]. The maximum number of dead tracks (MNDT) that can be tolerated in the absence of channel errors can be derived in a similar manner. Specifically, the formula: MNDT=floor(( N 2 −K 2 )/( N 2 /T )) may be used to compute the maximum number of dead tracks. Based on the synchronized codeword quad (SCQ), which is the SCO structure of LTO-4, TABLE 1 shows specific configurations of C2-code designs and properties with regard to maximum stripe error length and dead track support. In TABLE 1, an erasure-correction margin of M=2 was assumed. It should be emphasized that the CO-interleaving Expression 1 applies in all these cases. All C2-codes with N 2 >64 have 3.7% improved format efficiency (FE) when compared to the C2-code in LTO-4 (see first row in TABLE 1). All of these long C2-codes have improved error rate performance that translates into a gain in linear density. The linear density gains in TABLE 1 were obtained from measurements in the lab using a semi-analytic approach. TABLE 1 Specific C2-Code Configurations for Codeword Quad-Based SCO-Structures Relative FE Lin. density MSEL N 2 K 2 Tracks T S DS size in % gain in % in SCQs Dead tracks 64 54 16 64 1X 0 0 16 2 128 112 16 32 1X 3.7 6.5 14 2 128 112 16 64 2X 3.7 6.5 28 2 128 112 32 64 2X 3.7 6.5 14 4 128 112 32 128 4X 3.7 6.5 28 4 96 84 16 64   1.5X 3.7 4.0 20 2 96 84 24 96   2.25X 3.7 4.0 20 3 96 84 32 128 3X 3.7 4.0 20 4 192 168 16 32   1.5X 3.7 8.5 22 2 192 168 24 48   2.25X 3.7 8.5 22 3 192 168 32 64 3X 3.7 8.5 22 4 In TABLES 2 and 3, the results are summarized for the two described embodiments for T=16 parallel tracks and SCO-structures, which are based on codeword quads and octets, respectively. The length of a codeword octet in [mm] is roughly twice as long as that of a codeword quad. Thus, for the ECC-1 scheme, the maximum stripe error length of 20 SCQs is comparable to 10 SCOs in TABLES 2 and 3, respectively. TABLE 2 Proposed C2-Code Configurations for Codeword Quad-Based SCO-Structures and T = 16 Tracks Lin. Relative FE density MSEL Dead Code N 2 K 2 S DS size in % gain in % in SCQs tracks LTO-4 64 54 64 1X   0 0 16 2 ECC-1 96 84 64 1.5X 3.7 4.0 20 2 ECC-2 192 168 32 1.5X 3.7 8.5 22 2 TABLE 3 Proposed C2-Code Configurations for Codeword Octet-Based SCO-Structures and T = 16 Tracks. Lin. Relative FE density MSEL Dead Code N 2 K 2 S DS size in % gain in % in SCOs tracks ECC-1 96 84 32 1.5X 3.7 4.0 10 2 ECC-2 192 168 32 3X   3.7 8.5 22 2 It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable storage media include recordable-type media such as a floppy disk, a hard disk drive, a RAM, and CD-ROMs. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. Moreover, although described above with respect to methods and systems, the need in the art may also be met with a computer program product containing instructions for writing data to a multi-track data tape medium or a method for deploying computing infrastructure comprising integrating computer readable code into a computing system for writing data to a multi-track data tape medium.

Conventional C2 coding and interleaving for multi-track data tape in LTO-3/4 do not support recording data onto a number of concurrent tracks which is not a power of two. Higher-rate longer C2 codes, which do not degrade error rate performance, are provided. An adjustable format and interleaving scheme accommodates future tape drives in which the number of concurrent tracks is not necessarily a power of two. A data set is segmented into a plurality of unencoded subdata sets and parity bytes are generated for each row and column. The parameters of the C2 code include N 2 as the least common multiple of the number of possible tracks to which codeword objects are to be written. COs are formed from N 2 C1 codewords, mapped onto a logical data track according to information within headers of the CO and modulation encoded into synchronized COs which are written to the tape.

TECHNICAL FIELD [0001] This disclosure is generally directed to field devices in a plant. More specifically, this disclosure is directed to an apparatus and method to detect smart device configuration changes against a reference in process control systems. BACKGROUND [0002] Industrial control systems (ICS) can adhere to safety guidelines set by the International Electrotechnical Commission (IEC). An IEC Final Draft International Standard (FDIS) 61511-1 guidelines have set that smart device configurations should not be changed post commissioning. IEC 61511 categorizes smart instruments as type B devices and fixed program language (FPL) devices. If an accident occurs and these guidelines are not followed, it will be difficult to justify why a company did not comply with the guidelines. Periodically, a report is generated for safety audit purposes to show that the smart device configuration have not changed since commissioning. Customers are concerned that any change in smart device configuration could severely impact their process (continuous/batch). Producing a report for a single smart device could take around an hour. Factories can have more many smart devices, ultimately consuming more manual effort and increasing costs. Customers might miss producing the periodic reports because of many manual dependencies. A maintenance engineer must be well trained to generate the reports, as it involves selecting a right reference and ignoring non-configuration parameters. As the method is human dependent, there can be human errors. SUMMARY [0003] This disclosure provides an apparatus and method to detect smart device configuration changes against a reference in process control systems. [0004] In a first example, a method is provided for managing a master gold record in an industrial automation system. The method includes receiving a master golden record for a device of a plurality of devices in the industrial automation system. The master golden record includes one or more parameter values for the device for a mode of the industrial automation system. The method also includes identifying an active mode for the industrial automation system. The method also includes responsive to a triggering of a comparison, comparing current parameter values of the device with the one or more parameter values of the master golden record for the active mode. The method also includes generating a report comprising differences between the one or more parameters values of the master golden record and the current parameter values of the device. [0005] In a second example, an apparatus includes a memory configured to store a master golden record. The apparatus also includes a processing device coupled to the memory. The processing device is configured to receive the master golden record for a device of a plurality of devices in a industrial automation system. The master golden record includes one or more parameter values for the device for a mode of the industrial automation system. The processing device is also configured to identify an active mode for the industrial automation system. The processing device is also configured to responsive to a triggering of a comparison, compare current parameter values of the device with the one or more parameter values of the master golden record for the active mode. The processing device is also configured to generate a report comprising differences between the one or more parameters values of the master golden record and the current parameter values of the device. [0006] In a third example, a non-transitory computer readable medium includes a computer program. The computer program comprises computer readable program code for receiving a master golden record for a device of a plurality of devices in a industrial automation system. The master golden record includes one or more parameter values for the device for a mode of the industrial automation system. The computer readable program code is also for identifying an active mode for the industrial automation system. The computer readable program code is also for responsive to a triggering of a comparison, comparing current parameter values of the device with the one or more parameter values of the master golden record for the active mode. The computer readable program code is also for generating a report comprising differences between the one or more parameters values of the master golden record and the current parameter values of the device. BRIEF DESCRIPTION OF THE DRAWINGS [0007] For a more complete understanding of this disclosure and its features, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: [0008] FIG. 1 illustrates an example industrial process control and automation system and related details according to this disclosure; [0009] FIG. 2 illustrates an example device for managing recordation of changes in a smart device according to this disclosure; [0010] FIG. 3 illustrates an example block diagram of a configuration management system according to this disclosure; and [0011] FIG. 4 illustrates an example master golden record management process according to this disclosure. DETAILED DESCRIPTION [0012] FIGS. 1 through 4 , discussed below, and the various examples used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitable manner and in any type of suitably arranged device or system. [0013] FIG. 1 illustrates an example industrial process control and automation system 100 and related details according to this disclosure. As shown in FIG. 1 , the system 100 includes various components that facilitate production or processing of at least one product or other material. For instance, the system 100 is used here to facilitate control over components in one or multiple plants 101 a - 101 n . Each plant 101 a - 101 n represents one or more processing facilities (or one or more portions thereof), such as one or more manufacturing facilities for producing at least one product or other material. In general, each plant 101 a - 101 n may implement one or more processes and can individually or collectively be referred to as a process system. A process system generally represents any system or portion thereof configured to process one or more products or other materials in some manner. [0014] In FIG. 1 , the system 100 is implemented using the Purdue model of process control. In the Purdue model, “Level 0” may include one or more sensors 102 a and one or more actuators 102 b . The sensors 102 a and actuators 102 b represent components in a process system that may perform any of a wide variety of functions. For example, the sensors 102 a could measure a wide variety of characteristics in the process system, such as temperature, pressure, or flow rate. Also, the actuators 102 b could alter a wide variety of characteristics in the process system. The sensors 102 a and actuators 102 b could represent any other or additional components in any suitable process system. Each of the sensors 102 a includes any suitable structure for measuring one or more characteristics in a process system. Each of the actuators 102 b includes any suitable structure for operating on or affecting one or more conditions in a process system. [0015] At least one network 104 is coupled to the sensors 102 a and actuators 102 b . The network 104 facilitates interaction with the sensors 102 a and actuators 102 b . For example, the network 104 could transport measurement data from the sensors 102 a and provide control signals to the actuators 102 b . The network 104 could represent any suitable network or combination of networks. As particular examples, the network 104 could represent an Ethernet network, an electrical signal network (such as a HART or FOUNDATION FIELDBUS network), a pneumatic control signal network, or any other or additional type(s) of network(s). [0016] In the Purdue model, “Level 1” may include one or more controllers 106 , which are coupled to the network 104 . Among other things, each controller 106 may use the measurements from one or more sensors 102 a to control the operation of one or more actuators 102 b . For example, a controller 106 could receive measurement data from one or more sensors 102 a and use the measurement data to generate control signals for one or more actuators 102 b . Each controller 106 includes any suitable structure for interacting with one or more sensors 102 a and controlling one or more actuators 102 b . Each controller 106 could, for example, represent a multivariable controller, such as a Robust Multivariable Predictive Control Technology (RMPCT) controller, or other type of controller implementing model predictive control (MPC) or other advanced predictive control (APC). As a particular example, each controller 106 could represent a computing device running a real-time operating system. [0017] In one or more example embodiments of this disclosure, sensors 102 a and actuators 102 b can be smart devices. These smart devices can include different parameter values 160 . Parameter values 160 can be settings and configurations of a smart device to perform specific functions in an active mode of the system 100 . For example, Lower Range Value (LRV) and Upper Range Value (URV) can be configuration parameters while Primary value (PV) can be a non-configuration parameter. Each smart device can have different values for different modes. The different modes can be set based on product, version of the product being manufactured, or a service being executed. [0018] Two networks 108 are coupled to the controllers 106 . The networks 108 facilitate interaction with the controllers 106 , such as by transporting data to and from the controllers 106 . The networks 108 could represent any suitable networks or combination of networks. As particular examples, the networks 108 could represent a pair of Ethernet networks or a redundant pair of Ethernet networks, such as a FAULT TOLERANT ETHERNET (FTE) network from HONEYWELL INTERNATIONAL INC. [0019] At least one switch/firewall 110 couples the networks 108 to two networks 112 . The switch/firewall 110 may transport traffic from one network to another. The switch/firewall 110 may also block traffic on one network from reaching another network. The switch/firewall 110 includes any suitable structure for providing communication between networks, such as a HONEYWELL CONTROL FIREWALL (CF9) device. The networks 112 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network. [0020] In the Purdue model, “Level 2” may include one or more machine-level controllers 114 coupled to the networks 112 . The machine-level controllers 114 perform various functions to support the operation and control of the controllers 106 , sensors 102 a , and actuators 102 b , which could be associated with a particular piece of industrial equipment (such as a boiler or other machine). For example, the machine-level controllers 114 could log information collected or generated by the controllers 106 , such as measurement data from the sensors 102 a or control signals for the actuators 102 b . The machine-level controllers 114 could also execute applications that control the operation of the controllers 106 , thereby controlling the operation of the actuators 102 b . In addition, the machine-level controllers 114 could provide secure access to the controllers 106 . Each of the machine-level controllers 114 includes any suitable structure for providing access to, control of, or operations related to a machine or other individual piece of equipment. Each of the machine-level controllers 114 could, for example, represent a server computing device running a MICROSOFT WINDOWS operating system. Although not shown, different machine-level controllers 114 could be used to control different pieces of equipment in a process system (where each piece of equipment is associated with one or more controllers 106 , sensors 102 a , and actuators 102 b ). [0021] One or more operator stations 116 are coupled to the networks 112 . The operator stations 116 represent computing or communication devices providing user access to the machine-level controllers 114 , which could then provide user access to the controllers 106 (and possibly the sensors 102 a and actuators 102 b ). As particular examples, the operator stations 116 could allow users to review the operational history of the sensors 102 a and actuators 102 b using information collected by the controllers 106 and/or the machine-level controllers 114 . The operator stations 116 could also allow the users to adjust the operation of the sensors 102 a , actuators 102 b , controllers 106 , or machine-level controllers 114 . In addition, the operator stations 116 could receive and display warnings, alerts, or other messages or displays generated by the controllers 106 or the machine-level controllers 114 . Each of the operator stations 116 includes any suitable structure for supporting user access and control of one or more components in the system 100 . Each of the operator stations 116 could, for example, represent a computing device running a MICROSOFT WINDOWS operating system. [0022] At least one router/firewall 118 couples the networks 112 to two networks 120 . The router/firewall 118 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The networks 120 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network. [0023] In the Purdue model, “Level 3” may include one or more unit-level controllers 122 coupled to the networks 120 . Each unit-level controller 122 is typically associated with a unit in a process system, which represents a collection of different machines operating together to implement at least part of a process. The unit-level controllers 122 perform various functions to support the operation and control of components in the lower levels. For example, the unit-level controllers 122 could log information collected or generated by the components in the lower levels, execute applications that control the components in the lower levels, and provide secure access to the components in the lower levels. Each of the unit-level controllers 122 includes any suitable structure for providing access to, control of, or operations related to one or more machines or other pieces of equipment in a process unit. Each of the unit-level controllers 122 could, for example, represent a server computing device running a MICROSOFT WINDOWS operating system. Although not shown, different unit-level controllers 122 could be used to control different units in a process system (where each unit is associated with one or more machine-level controllers 114 , controllers 106 , sensors 102 a , and actuators 102 b ). [0024] Access to the unit-level controllers 122 may be provided by one or more operator stations 124 . Each of the operator stations 124 includes any suitable structure for supporting user access and control of one or more components in the system 100 . Each of the operator stations 124 could, for example, represent a computing device running a MICROSOFT WINDOWS operating system. [0025] At least one router/firewall 126 couples the networks 120 to two networks 128 . The router/firewall 126 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The networks 128 could represent any suitable networks, such as a pair of Ethernet networks or an FTE network. [0026] In the Purdue model, “Level 4” may include one or more plant-level controllers 130 coupled to the networks 128 . Each plant-level controller 130 is typically associated with one of the plants 101 a - 101 n , which may include one or more process units that implement the same, similar, or different processes. The plant-level controllers 130 perform various functions to support the operation and control of components in the lower levels. As particular examples, the plant-level controller 130 could execute one or more manufacturing execution system (IVIES) applications, scheduling applications, or other or additional plant or process control applications. Each of the plant-level controllers 130 includes any suitable structure for providing access to, control of, or operations related to one or more process units in a process plant. Each of the plant-level controllers 130 could, for example, represent a server computing device running a MICROSOFT WINDOWS operating system. [0027] Access to the plant-level controllers 130 may be provided by one or more operator stations 132 . Each of the operator stations 132 includes any suitable structure for supporting user access and control of one or more components in the system 100 . Each of the operator stations 132 could, for example, represent a computing device running a MICROSOFT WINDOWS operating system. [0028] At least one router/firewall 134 couples the networks 128 to one or more networks 136 . The router/firewall 134 includes any suitable structure for providing communication between networks, such as a secure router or combination router/firewall. The network 136 could represent any suitable network, such as an enterprise-wide Ethernet or other network or all or a portion of a larger network (such as the Internet). [0029] In the Purdue model, “Level 5” may include one or more enterprise-level controllers 138 coupled to the network 136 . Each enterprise-level controller 138 is typically able to perform planning operations for multiple plants 101 a - 101 n and to control various aspects of the plants 101 a - 101 n . The enterprise-level controllers 138 can also perform various functions to support the operation and control of components in the plants 101 a - 101 n . As particular examples, the enterprise-level controller 138 could execute one or more order processing applications, enterprise resource planning (ERP) applications, advanced planning and scheduling (APS) applications, or any other or additional enterprise control applications. Each of the enterprise-level controllers 138 includes any suitable structure for providing access to, control of, or operations related to the control of one or more plants. Each of the enterprise-level controllers 138 could, for example, represent a server computing device running a MICROSOFT WINDOWS operating system. In this document, the term “enterprise” refers to an organization having one or more plants or other processing facilities to be managed. Note that if a single plant 101 a is to be managed, the functionality of the enterprise-level controller 138 could be incorporated into the plant-level controller 130 . [0030] Access to the enterprise-level controllers 138 may be provided by one or more operator stations 140 . Each of the operator stations 140 includes any suitable structure for supporting user access and control of one or more components in the system 100 . Each of the operator stations 140 could, for example, represent a computing device running a MICROSOFT WINDOWS operating system. [0031] Various levels of the Purdue model can include other components, such as one or more databases. The database(s) associated with each level could store any suitable information associated with that level or one or more other levels of the system 100 . For example, a historian 141 can be coupled to the network 136 . The historian 141 could represent a component that stores various information about the system 100 . The historian 141 could, for instance, store information used during production scheduling and optimization. The historian 141 represents any suitable structure for storing and facilitating retrieval of information. Although shown as a single centralized component coupled to the network 136 , the historian 141 could be located elsewhere in the system 100 , or multiple historians could be distributed in different locations in the system 100 . [0032] In particular embodiments, the various controllers and operator stations in FIG. 1 may represent computing devices. For example, each of the controllers could include one or more processing devices 142 and one or more memories 144 for storing instructions and data used, generated, or collected by the processing device(s) 142 . Each of the controllers could also include at least one network interface 146 , such as one or more Ethernet interfaces or wireless transceivers. Also, each of the operator stations could include one or more processing devices 148 and one or more memories 150 for storing instructions and data used, generated, or collected by the processing device(s) 148 . Each of the operator stations could also include at least one network interface 152 , such as one or more Ethernet interfaces or wireless transceivers. [0033] Although FIG. 1 illustrates one example of an industrial process control and automation system 100 , various changes may be made to FIG. 1 . For example, a control and automation system could include any number of sensors, actuators, controllers, operator stations, networks, servers, communication devices, and other components. In addition, the makeup and arrangement of the system 100 in FIG. 1 is for illustration only. Components could be added, omitted, combined, further subdivided, or placed in any other suitable configuration according to particular needs. Further, particular functions have been described as being performed by particular components of the system 100 . This is for illustration only. In general, control and automation systems are highly configurable and can be configured in any suitable manner according to particular needs. In addition, FIG. 1 illustrates an example environment in which information related to an industrial process control and automation system can be transmitted to a remote server. This functionality can be used in any other suitable system. [0034] FIG. 2 illustrates an example device 200 for managing recordation of changes in a smart device according to this disclosure. The device 200 could represent, for example, the field device 102 , enterprise controller 138 , operator station 140 , or a local or remote server in the system 100 of FIG. 1 . However, the device 200 could be used in any other suitable system. [0035] As shown in FIG. 2 , the device 200 includes a bus system 202 , which supports communication between at least one processing device 204 , at least one storage device 206 , at least one communications unit 208 , and at least one input/output (I/O) unit 210 . The processing device 204 executes instructions that may be loaded into a memory 212 . The processing device 204 may include any suitable number(s) and type(s) of processors or other devices in any suitable arrangement. Example types of processing devices 204 include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, and discrete circuitry. [0036] The memory 212 and a persistent storage 214 are examples of storage devices 206 , which represent any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, and/or other suitable information on a temporary or permanent basis). The memory 212 may represent a random access memory or any other suitable volatile or non-volatile storage device(s). The persistent storage 214 may contain one or more components or devices supporting longer-term storage of data, such as a ready only memory, hard drive, Flash memory, or optical disc. [0037] The communications unit 208 supports communications with other systems or devices. For example, the communications unit 208 could include a network interface that facilitates communications over at least one Ethernet, HART, FOUNDATION FIELDBUS, cellular, Wi-Fi, universal asynchronous receiver/transmitter (UART), serial peripheral interface (SPI) or other network. The communications unit 208 could also include a wireless transceiver facilitating communications over at least one wireless network. The communications unit 208 may support communications through any suitable physical or wireless communication link(s). The communications unit 208 may support communications through multiple different interfaces, or may be representative of multiple communication units with the ability to communication through multiple interfaces. [0038] The I/O unit 210 allows for input and output of data. For example, the I/O unit 210 may provide a connection for user input through a keyboard, mouse, keypad, touchscreen, or other suitable input device. The I/O unit 210 may also send output to a display, printer, or other suitable output device. [0039] The device 200 could execute instructions used to perform any of the functions associated with the components of FIG. 1 . For example, the device 200 could execute instructions that retrieve and upload information to and from a transmitter or field device. The device 200 could also store user databases. [0040] Although FIG. 2 illustrates one example of a device 200 , various changes may be made to FIG. 2 . For example, components could be added, omitted, combined, further subdivided, or placed in any other suitable configuration according to particular needs. Also, computing devices can come in a wide variety of configurations, and FIG. 2 does not limit this disclosure to any particular configuration of computing device. [0041] One or more embodiments of this disclosure recognize and take into account that currently an operator chooses an appropriate master golden record (MGR) based on a current plant mode for a smart device. The operator can compare a current online configuration of the smart device with the above selected MGR either manually or by using any compare configuration tools if any provided by existing asset management systems. The operator is able to use personal best knowledge or consult an appropriate guide to determine if any configuration has changed, generate a report manually, and archive the report. The operator may repeat the process for all other smart devices for which reporting is required. Generating a report for a single smart device can take significant amount of time. For a plant where the number of smart devices can be thousands, the approximate manual effort for generating reports for all smart devices would consume many more thousands of man-hours. [0042] One or more embodiments of this disclosure provides an industrial automation system and an automated procedure to periodically compare the current online configuration parameter values of one or more smart devices with its respective MGR in the current running plant modes. The solution does so in defined schedule, notifies the status of execution to the user and generates report. Report will be archived for future retrieval. The solutions also audit trails all the user actions for future audits. [0043] FIG. 3 illustrates an example block diagram of a configuration management system 300 according to this disclosure. For ease of explanation, the system 300 is described as being supported by the industrial process control and automation system 100 of FIG. 1 . However, the system 300 could be supported by any other suitable system. The system 300 can be implemented in a device, such as device 200 as shown in FIG. 2 . [0044] In FIG. 3 , system 300 includes master golden record (MGR) manager 302 , schedule manager 304 , mode manager 306 , configuration comparer 308 , report archiver 310 , report generator 312 , audit trail 314 , configuration database 316 , and communication sub-system 318 . The system 300 can communicate with different smart devices, such as components on FIG. 1 , through the communication sub-system 318 . One or more of the components 302 - 318 used herein can be implemented as part of processing circuitry, instructions on a non-transitory computer readable medium, as a processor, and the like. [0045] In one or more embodiments herein, a smart device can be a field device used in a process control system supporting protocols such as HART, Wireless HART, Foundation Fieldbus, Modbus, IEC 61850, EthernetIP, ISA100, Profibus DP, PA, Profinet, etc. In different embodiments of this disclosure, the smart devices can represent, or be represented by, any of the components 102 - 134 as shown in FIG. 1 . As discussed herein, one or more of the embodiments of this disclosure can be used in any electrical monitoring and control system as well as any process control system. Additionally, the embodiments herein can be in non-safety as well as safety devices. [0046] In an embodiment of this disclosure, the MGR manager 302 is configured to allow a user 301 to create, retrieve, update, and delete the MGR for one or more smart devices. The MGR can be the project engineering configuration parameter with values of any smart device for a given mode. Other terms used for MGR are reference record, golden record, or golden reference record etc. Any history or offline record can be marked as a MGR. the user 301 may define multiple groups of devices that can be verified against a golden record. For batch comparisons, a specific group of devices can be selected each time. In different embodiments, a golden record can be created from a live device. [0047] In different embodiments, a golden record can be a single, well-defined version of all the data entities in an organizational ecosystem. In this context, a golden record is sometimes called the “single version of the truth,” where “truth” is understood to mean the reference to which data users can turn when they want to ensure that they have the correct version of a piece of information. The golden record encompasses all the data in every system of record (SOR) within a particular organization. A SOR is an information storage and retrieval system (ISRS) that serves as the authoritative source for a particular data element in an industrial automation system containing multiple sources of the same element. To ensure data integrity, a single SOR must always exist for each and every data element. [0048] In one or more embodiments herein, a history record is the snapshot of the parameter values of any smart device taken at a given point of interest. The history record can be the same as taking a backup of the parameter values from an online smart device. For example, the backup can be a snapshot taken after commissioning of the smart device, after factory acceptance test, and the like. Other terms used for history record are device snapshot, and the like. The user can optionally select all configuration parameters or few. In another embodiment, the user or system can mark an existing history record as the MGR. In yet another embodiment, the user or system can mark an existing offline record as the MGR. In one or more embodiments herein, an offline record can be the configuration parameters stored in configuration database 316 that is prepopulated either manually or from a connected smart device. The MGR manager 302 can provide an option to the user to view, update, and delete any MGR. The MGR manager 302 can also map any MGR to a mode. [0049] In one or more embodiments of this disclosure, the MGR is set at a time of commissioning. In different embodiments of this disclosure, the MGR can be set after commissioning. In some example embodiments, after setting, the MGR can be modified, such as by use of a proper management of change procedure. [0050] The schedule manager 304 is configured to provide an option to the user 301 to schedule a one time or periodic (daily, weekly, monthly, etc.) configuration comparison mechanism for one or more smart devices. The schedule manager 304 can also allow the user 301 to retrieve, update and delete schedules 305 . [0051] The MGR can be compared to the live online configuration parameter values of any smart device by executing the comparison now, or by scheduling the comparison. For executing now, the schedule manager 304 provides an option to the user to compare online configuration parameter values of a smart device with a MGR. For scheduling, the schedule manager 304 provides an option to create either a one time or recurring schedule for automatic/semiautomatic comparison of online configuration parameter values of a smart device with the MGR. [0052] For an automatic schedule, the schedule manager 304 compares online configuration parameter values of a smart device with the MGR automatically without any user input and archiving the report. For a semiautomatic schedule, the schedule manager 304 compares an online configuration parameter values of a smart device with a MGR post user confirmation via any detectable means such as user interface prompting the user for confirmation or via voice confirmation or via any electronically detectable means like by sending authorization via SMS to a pre defined number, by sending authorization via email to a pre defined E-Mail ID, or the like. [0053] In one or more embodiments, the schedule manager 304 can provide an option to the user to view, update, and delete any schedule. The schedule manager 304 can also provide the user with an option for configuring a reminder for any schedule. The schedule manager 304 can also provide an option to the user for cancelling the occurrence of a schedule or to “snooze” the occurrence to some future time. [0054] The mode manager 306 is configured to provide an option to set the current active modes 307 of the plant. Active mode 307 can be a current mode being used in the plant for an industrial process control and automation system. The mode manager 306 can synchronize the current active modes from the existing distributed control system (DCS), supervisory control and data acquisition (SCADA) system, or programming logic controller (PLC) system automatically or by providing explicit means to update the systems. The mode manager 306 can also allow the 301 to create, retrieve, update and delete modes. In one or more embodiments herein, a mode refers to different production modes of the plant. Difference production modes can be applied to continuous or batch plants, where a startup or high production mode might require different instrumentation settings. Different instrumentation settings can be used in a batch plant where on a particular production line multiple products can be produced. Depending on the product being produced, different product properties may cause different instrument settings to be used. [0055] In different embodiments, multiple golden records can be provided for each device depending on the operational mode of the plant. This type of system can be useful for batch plants or semi-continuous plants that are frequently reconfigured. For example, if there is a soup production line, each device could have one golden record for each device when producing “chicken soup” and another golden record when producing “vegetable soup.” The golden records can be swapped when switching production line items. [0056] In one or more embodiments, the mode manager 306 provides the user with an option to create, retrieve, update and delete modes. The mode manager 306 can sync the modes from DCS, SCADA, or PLC systems automatically or user triggered. The mode manager 306 can set one or more active modes, i.e. the current operating modes of the plant. Setting the modes can involve syncing active modes from DCS, SCADA, or PLC systems. [0057] The MGR manager 302 , schedule manager 304 , and mode manager 306 can all be accessed by the user 301 to modify an MGR, schedule a comparison 309 , or modify a mode of the plant. All of the actions performed with these managers 302 , 304 , 306 can be recorded by an audit trail subsystem 314 . [0058] The configuration comparer 308 is configured to compare the current smart device configuration with a given MGR. The schedule manager 304 can initiate the configuration comparer 308 to begin a comparison 309 . The comparison 309 can provide an identification of added, deleted, or changed parameters or configurations of the smart device. To perform the comparison 309 , the configuration comparer 308 is configured to access the different smart devices through the communication sub-system 318 and compare the current configurations to the MGRs accessed from the configuration database 316 . [0059] In one or more embodiments, the configuration comparer 308 can compare the current smart device configuration parameter values with that of a mapped MGR in the current active mode. The configuration comparer 308 can also identify configuration parameters and comparing only those parameter values while ignoring all other non-configuration parameters. For example, Lower Range Value (LRV) and Upper Range Value (URV) can be configuration parameters while Primary value (PV) can be a non-configuration parameter. The configuration comparer 308 can notify the user about the progress and status of the current execution. The configuration comparer 308 can also allow the user to cancel the current execution. In different embodiments, the configuration comparer 308 can compare the configuration parameter values for multiple smart devices with their respective MGR either sequentially or in parallel. The configuration comparer 308 can be triggered either manually, automatically by the scheduler, or upon authorization from user. [0060] The report generator 312 is configured to generate reports 313 citing differences as reported by the configuration comparer 308 . The reports can be presented in different formats. The report can include or exclude different parameters of the smart devices. For example, in one report, all parameters can be included. In other reports, a subset of parameters can be included. The report generator 312 can retrieve the comparison result from execution and prepare a report in the user or system-configured format. The report generator 312 can report the following data (but not limited to): a summary of the overall execution such as how many smart device comparison have failed or passed; a number of smart devices for which a comparison couldn't be performed, the devices are cancelled, or the devices encountered some issues during execution; and the exact configuration parameters that have changed from their respective MGR values. The report generator 312 can provide an option to the user to view, delete any report. The report generator 312 can also provide an option to print or export to file system in any human readable format such as (but not limited to) PDF, HTML, CSV, DOC, XLS, XPS and the like. [0061] The report archiver 310 is configured to archive the report generated by the report generator 312 and provides means for future retrieval. The report archiver 310 can be a database, either local or remote. [0062] The audit trail subsystem 314 is configured to log all user actions with appropriate user, action, and timestamp details. The audit trail subsystem 314 also provides a mechanism to view, modify, and delete these audit trails. The audit trail subsystem 314 audits all user actions such as creating, updating, and deleting of MGRs, modes, or schedules. The audit trail subsystem 314 retrieves audit trail details as required, exports audit trail records to a human readable format, and logs user info, actions performed, time stamp, and any comments. The audit trail subsystem 314 can also provide an option to the user to print audit trail records. [0063] The configuration database 316 can be a database containing the MGRs 317 for each smart device per specific mode. Each of the MGRs can include one or more parameters or values for the one or more parameters for different smart devices. In one or more embodiments herein, a database is a repository for storing and retrieving the required data. The configuration database 316 could be a file system based repository, an RDBMS, a cloud based repository, or the like. Each MGR 317 includes different parameter values 319 for the smart devices. The parameter values can be the settings and configurations for the smart device for each mode of the system. [0064] The communication subsystem 318 is configured to provide communication with the smart devices. [0065] One or more embodiments provides for golden record management by the MGR manager 302 . Golden record management involves a creation of a history record from live online smart device configuration parameters (i.e., the parameters of the devices currently in use) and saving those parameters as the MGR. The MGR alternatively can also be created from offline dataset of the smart device. [0066] FIG. 4 illustrates an example master golden record management process 400 according to this disclosure. The golden record management process 400 provides for scheduling of a comparison of a MGR with device parameters. Process 400 can be executed within system 300 of FIG. 3 and/or by device 200 of FIG. 2 . [0067] At operation 405 , a processor receives a user selection of a MGR for each smart device. In different embodiments, the selection can be a batch selection for multiple smart devices. In various embodiments of this disclosure, operation 405 is only performed one time. The same MGR will then be used by the comparer every time a schedule elapses. In further embodiments, the MGR can be chosen on different occasions. [0068] At operation 410 , a processor can receive a user setting of a current active mode of a plant. The mode can be based on a product, or a version of a production under production. [0069] At operation 415 , a processor receives a new schedule from a user that is created for one or more smart devices. The schedule can set when the comparison is performed. At operation 420 , the processor can control a scheduler manager to run a schedule based on the defined schedule. [0070] At operation 425 , the processor can control a scheduler manager to trigger a configuration parameter comparison when the scheduled time elapses. While the schedule is running, different scheduled times may elapse and trigger different comparisons. At operation 430 , the processor can compare current online configuration parameter values with a MGR and generate any differences of parameters. The current configuration parameter values can be current parameter settings and configurations being used during current production. [0071] At operation 435 , the processor can configure a comparer triggers report with differences to use when generating a report. At this operation, the report to be generated can be configured with which differences are to be reported. At operation 440 , the processor controls a report generator to generate reports according to the pre-configured format and also trigger a report archiver. [0072] At operation 445 , the processor controls a report archiver to archive the report for future retrieval. At operation 450 , the processor determines if all of the smart devices are done. In an embodiment, the processor determines if all smart devices that are scheduled have been compared to the MGRs. If all of the smart devices are not done, the processor moves to operation 430 with another smart device. If all of the smart devices are done, then the processor, at operation 455 , controls the scheduler manager to wait for the next schedule. [0073] At operation 460 , the processor determines if there is a next schedule available. If no other schedules are available at that time, then the processor controls the scheduling manager to wait for the next schedule at operation 455 . If there is a next schedule available, then the process moves to operation 430 for the device triggered by the schedule. [0074] As discussed herein, one or more steps can be performed by a processor or different components controlled by the processor. However, the processor can directly perform the steps performed by components controlled by the processor. [0075] Although FIG. 4 illustrates one example of a process 400 scheduling of a comparison of a MGR with device parameters in an industrial process control and automation system, various changes may be made to FIG. 4 . For example, while FIG. 4 shows a series of steps, various steps could overlap, occur in parallel, occur in a different order, or occur any number of times. In addition, the process 400 could include any number of events, event information retrievals, and notifications. [0076] In some embodiments, various functions described above are implemented or supported by a computer program that is formed from computer readable program code and that is embodied in a computer readable medium. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device. [0077] It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer code (including source code, object code, or executable code). The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. [0078] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.

A method is provided for comparing a master gold record with a live device in an industrial automation system. The method includes receiving a master golden record for a device of a plurality of devices in the industrial automation system. The master golden record includes one or more parameter values for the device for a mode of the industrial automation system. The method also includes identifying an active mode for the industrial automation system. The method also includes responsive to a triggering of a comparison, comparing current parameter values of the device with the one or more parameter values of the master golden record for the active mode. The method also includes generating a report comprising differences between the one or more parameters values of the master golden record and the current parameter values of the device.

FIELD OF THE INVENTION [0001] The present invention relates to a process for manufacturing a gas sensor including a detecting element having an electrode of a precious metal formed on the surface of a solid electrolyte. BACKGROUND OF THE INVENTION [0002] In the conventional art, there has been developed an oxygen sensor, which is provided with a detecting element having a detecting electrode and a reference electrode of platinum acting as an oxidation promoting catalyst formed on the outer wall and inner wall of a solid electrolyte (as will be called the “substrate”) of a cylindrical shape having one end closed, so that it may detect an oxygen concentration on the principle of an oxygen concentration cell. This oxygen sensor is attached to the internal combustion engine of an automobile or the like so that it may be used for grasping the combustion state (or the A/F ratio) of the internal combustion engine. [0003] Here, the detecting electrode of the detecting element in that oxygen sensor is formed through a nucleus depositing step of depositing the nuclei of platinum on the surface of the substrate and an electroless plating step of growing the deposited nuclei by an electrolessly plating method or an electrically plating method (as referred to JP-B-62-56978 (the term “JP-B” as used herein means an “examined Japanese patent publication”), for example). [0004] First of all, at the nucleus depositing step (corresponding to the active point forming electrolessly plating step in JP-B-62-56978), the nuclei of platinum are deposited on the outer wall of the substrate by dipping the substrate in a container containing an aqueous solution of platinic ammine and by adding to this aqueous solution a reducer of sodium boron hydride (SBH) having a high reducing power. At this nucleus depositing step, however, at the time of dipping the substrate in the aqueous solution of platinic ammine, the portion of the outer wall of the substrate other than the desired one is coated with masking rubber so that the nuclei may not be deposited on the undesired portion. [0005] At the end of the nucleus depositing step, moreover, the substrate is taken out from the container, and the masking rubber is removed. The substrate is rinsed to clear the outer wall of the substrate of the platinic ammine and the sodium boron hydride, and the process transfers to the nucleus growing step. [0006] At the nucleus growing step (corresponding to the thin film electrolessly plating step and the thick film electric plating step in JP-B-62-56978 (pp. 3 to 4, FIG. 2)), like the nucleus depositing step, the substrate is dipped in the container containing the aqueous solution of platinic ammine, and a reducer of hydrazine having a weaker reducing power is added to that aqueous solution so that the nuclei deposited on the outer wall of the substrate may be gently grown to form the detecting electrode on the outer wall of the substrate. Here, at the nucleus growing step, the substrate is dipped in the plating liquid without being coated with the masking rubber. SUMMARY OF THE INVENTION [0007] Here, the oxygen sensor manufactured by the aforementioned manufacturing process has a problem that the detecting electrode of the detecting element fails to act sufficiently as the oxidation promoting catalyst thereby to cause a loss in the responding performances. [0008] In the aforementioned detecting electrode, more specifically, the crystals of platinum after the nucleus growing step become coarse due to the large size of the nuclei deposited at the nucleus depositing step. Therefore, the number of intergranules of the platinum crystals is so small that the surface area (i.e., the surface area to act as the oxidation promotion catalyst) to contact with the exhaust gas is accordingly reduced. [0009] As a result, it takes a long time for the oxygen existing in the vicinity of the detecting electrode to combine with the unburned contents (e.g., hydrocarbons or carbon monoxide) in the exhaust gas thereby to equilibrate the exhaust gas. Therefore, a delay occurs in the responsibility. [0010] In the aforementioned manufacturing process, moreover, the sizes of the nuclei to be deposited become heterogeneous. Therefore, the thickness of the detecting electrode does not become uniform to cause a problem that the durable performances of the oxygen sensor are lost. In other words, the thinner portion of the detecting electrode sublimates earlier than the thicker portion. [0011] In the aforementioned manufacturing process, moreover, the plating liquid flows in from the clearance, if formed between the masking rubber and the outer wall of the substrate, so that the nuclei are deposited on the portion other than the desired one. Therefore, a problem is that cares have to be troublesomely taken on the mounting of the masking rubber. [0012] In order to solve the above-specified problems, therefore, the invention has an object to provide a process for manufacturing a gas sensor, which is excellent in responding performances and durable performances and which can form an electrode easily. [0013] In order to achieve the above-specified object, according to the invention, a process for manufacturing a gas sensor including a detecting element having an electrode of a precious metal formed on the surface of a solid electrolyte, comprising: a first step of applying the nuclei of a precious metal having a catalyzing action on a gas to be measured; and a second step of growing said nuclei, wherein said first step uses a physical vapor deposition (PVD) method. [0014] According to this gas sensor manufacturing process, the nuclei having the size of an atomic or molecular level can be applied to the surface of the solid electrolyte so that the crystals of the precious metal making the electrode can be made minute after the second step. In the gas sensor manufactured according to the invention, more specifically, the electrode of the detecting element has a number of intergranules of the crystals of the precious metal so that it has an accordingly larger surface area (i.e., a surface area to act as a catalyst) of the electrode to contact with the gas to be measured. In other words, the catalyzing action of the electrode can be improved by the invention thereby to provide a gas sensor having more excellent responding performances than those of the prior art. [0015] According to the invention, moreover, the sizes of the nuclei are individually homogenized so that the electrode to be formed can have a uniform thickness. Therefore, it is possible to provide a gas sensor, which is more excellent durable performances than those of the prior art. [0016] According to the invention, moreover, when the precious metal is to be deposited on the surface of the solid electrolyte, the evaporation of the precious metal can be prevented merely by arranging at least one of shielding plate and a shielding cover at a portion other than that to form an electrode. Therefore, the gas sensor can be troublelessly manufactured. By arranging at least one of the shielding plate and the shielding cover, moreover, an electrode of a desired shape can be easily formed on the surface of the solid electrolyte. [0017] Here, the physical deposition method is preferably exemplified by the sputtering method. In this case, even if the precious metal has a high melting point, the nuclei of the precious metal having a catalyzing action can be easily deposited on the surface of the solid electrolyte. [0018] Moreover, the sputtering is preferably done under a pressure of 5 to 10 Pa. This range may be defined because the residual gas to be ionized may fail to exist sufficiently for a pressure lower than 5 Pa whereas the glow discharge may not be done for a pressure higher than 10 Pa. But, the pressure range is variable due to a condition of a deposition apparatus, and therefore, the range is not essential for the invention. [0019] And, the second step is preferably exemplified by the electrolessly plating method. [0020] By using the electrolessly plating method, more specifically, the precious metal can be homogeneously deposited on the surface of the solid electrolyte. If the electroless plating is done by using the reducer having such a reducing power that the precious metal is not deposited on the portion other than that, to which the nuclei are applied, the nuclei can be homogeneously grown without depositing the precious metal at the portion other than that having the nuclei applied thereto. In other words, it is possible to form an electrode of a uniform thickness on the surface of the solid electrolyte. [0021] Here, the plating liquid of the process of the prior art can be used if it satisfies the condition that the precious metal is not deposited on the portion other that, to which the nuclei are applied. In other words, it is possible to use such an aqueous solution of complex salt of platinum and a reducer as satisfy the above-specified condition. If an aqueous solution of platonic (IV) ammine or an aqueous solution of platinous (II) ammine is used as said aqueous solution of complex salt of platinum, and wherein hydrazine is used as said reducer, more specifically, the deposition rate can be optimized to satisfy the condition that the precious metal is not deposited on the portion other than that, to which the nuclei are applied. [0022] If the plating is done by leaving the substrate, to which the nuclei of the precious metal were applied, to stand while being rocked in an electrolessly plating liquid, moreover, it is more effective to form the electrode having the uniform thickness. BRIEF DESCRIPTION OF THE DRAWINGS [0023] [0023]FIG. 1 is a sectional view showing the entire construction of an oxygen sensor 1 of a first embodiment; [0024] [0024]FIG. 2 is a lefthand side elevation of a detecting element 2 in FIG. 1; [0025] [0025]FIG. 3 is a righthand side elevation of a detecting element 2 in FIG. 1; [0026] [0026]FIG. 4 is a conceptional diagram schematically showing a nucleus applying step in the manufacture of the detecting element 2 ; [0027] [0027]FIG. 5 is a top plan view showing the exterior of a detecting element 70 to be used in an oxygen sensor of a second embodiment; [0028] [0028]FIG. 6 is a top plan view of the detecting element 70 on the back side of FIG. 5; [0029] [0029]FIG. 7 is a waveform diagram of the output of an oxygen sensor 1 , as recorded just after an electric power was supplied to the heater of the oxygen sensor of Example 1; [0030] [0030]FIG. 8 is a waveform diagram of the output of an oxygen sensor 1 , as recorded just after an electric power was supplied to the heater of the oxygen sensor of Example 2; [0031] [0031]FIG. 9 is a waveform diagram of the output of an oxygen sensor 1 , as recorded just after an electric power was supplied to the heater of the oxygen sensor of Comparison 1 ; [0032] [0032]FIG. 10 is a waveform diagram of the output of the oxygen sensor of Example 1 against the change in an A/F ratio control signal; [0033] [0033]FIG. 11 is a waveform diagram of the output of the oxygen sensor of Example 2 against the change in an A/F ratio control signal; [0034] [0034]FIG. 12 is a waveform diagram of the output of the oxygen sensor of Comparison 1 against the change in an A/F ratio control signal; [0035] [0035]FIG. 13 is a schematic diagram showing a modification of the nucleus applying step in Embodiments 1 and 2; and [0036] [0036]FIG. 14 is a schematic diagram showing a modification of the nucleus applying step in Embodiments 1 and 2. DETAILED DESCRIPTION OF THE INVENTION [0037] Embodiments of the invention will be described in the following with reference to the accompanying drawings. First Embodiment [0038] First of all, FIG. 1 is a sectional diagram showing the entire construction of an oxygen sensor, which is manufactured by applying the invention thereto. [0039] As shown in FIG. 1, an oxygen sensor 1 is constructed to include: a detecting element 2 made of a cylindrical substrate 20 composed mainly of zirconia and having one end closed; a rod-shaped ceramic heater (as will be shortly called the “heater”) 3 arranged in the detecting element 2 ; a casing for housing those detecting element 2 and heater 3 ; and a cylindrical protector 5 mounted on the lower end portion of the casing 4 for covering such a bottom portion (i.e., the closed one end) of the detecting element 2 as is protruded from the lower end portion of the casing 4 . [0040] Here, the casing 4 is constructed to include: a main fixture 40 for fixing the detecting element 2 in the casing 4 with annular ceramic holders 6 and 7 and ceramic powder 8 housed therein, and for fixing the oxygen sensor 1 on the exhaust pipe or the like of an internal combustion engine; and a cylindrical outer tube 41 extending upward of the main fixture 40 for introducing the atmosphere downward into the detecting element 2 . [0041] On the inner wall and outer wall of the upper end portion of the detecting element 2 , respectively, there are mounted terminal fixtures 50 and 51 for extracting an electromotive force from the detecting element 2 . With these terminal fixtures 50 and 51 , respectively, through lead wires 52 and 53 , there are connected connecting terminals 54 and 55 , which are protruded from the upper end portions of the outer tube 41 . With the upper end portion of the heater 3 , moreover, there is connected a connecting terminal 31 , which is protruded from the upper end portion of the outer tube 41 . Here, the heater 3 is fixed by the terminal fixture 51 in the detecting element 2 and is brought, by the leftward pushing force from the terminal fixture 51 , into contact with the inner circumference wall of the portion extending from the axially central portion to the bottom portion of the detecting element 2 . [0042] On the upper end portion of the outer tube 41 , moreover, there is caulked a cylindrical protecting outer tube 46 . This outer tube 46 is provided with: signal wires 42 and 43 for extracting the electromotive force generated by the detecting element 2 ; power lines (although not shown) for supplying the electric force to the heater 3 ; female terminals 44 and 45 for connecting the signal wires 42 and 43 and the connecting terminals 54 and 55 ; and female terminals (although not shown) for connecting the power lines and the connecting terminal 31 . The electromotive force of the detecting element 2 is extracted to the outside, and the electric power is supplied from the outside to the heater 3 . [0043] Here, FIG. 2 is a lefthand side elevation of the detecting element 2 in FIG. 1, and FIG. 3 is a righthand side elevation of a detecting element 2 in FIG. 1. [0044] As shown in FIGS. 2 and 3, the detecting element 2 is formed by covering the outer wall of such a portion L 1 with a detecting electrode 26 of platinum while making one round of the outer circumference of the substrate 20 , as extends from the leading end of the bottom portion and to the vicinity of the axially central portion of the substrate 20 . Here, this detecting electrode 26 is coated on its surface with powder of spinel (MgAl 2 O 4 ) (although not shown), thereby to protect the detecting electrode 26 against the heat of the exhaust gas. [0045] On the outer wall in the vicinity of the upper end portion of the substrate 20 , moreover, there is formed a band-shaped terminal connecting portion 28 , which makes one round of the outer circumference of the substrate 20 , thereby to connect the terminal fixture 50 . [0046] Between the detecting electrode 26 and the terminal connecting portion 28 , on the other hand, there is formed along the axial direction of the substrate 20 one long lead portion 27 , which has a sufficiently narrower width W 1 than that of the detecting electrode 26 and through which the detecting electrode 26 and the terminal connecting portion 28 are electrically connected. [0047] All over the inner wall of the substrate 20 , there is formed a reference electrode (although not shown), which is made of platinum like that of the detecting electrode 26 . [0048] A process for manufacturing the detecting element 2 will be described in detail in the following. [0049] At first, the substrate 20 is prepared by pressing a solid electrolyte composed mainly of zirconia into a cylindrical shape having one end closed, and then by sintering the cylindrical shape by exposing it to the atmosphere of 1,500° C. for 2 hours. At the sintering time, a platinum paste is printed in advance on the portions to form the lead portion 27 and the terminal connecting portion 28 , and these lead portion 27 and terminal connecting portion 28 are formed at the time of sintering the solid electrolyte. [0050] Next, the detecting electrode 26 is formed on the prepared substrate 20 . [0051] In order to form the detecting electrode 26 , a nucleus applying step of depositing the nucleus of platinum on the outer wall of the portion L 1 of the substrate 20 is performed by using Ion Coater of IB-3 manufactured by Eikoh Kabushiki Gaisha. Here, the Ion Coater is an apparatus for ionizing the residual gas (or air) by making a glow discharge in a low vacuum region (at 5 to 10 Pa) and for sputtering the atoms or molecules composing a target (i.e., platinum foil) by causing the ions of the residual gas to collide against the target. [0052] Here, FIG. 4 is a conceptional diagram schematically showing the nucleus applying step. [0053] At the nucleus applying step, as shown in FIG. 4, a support rod 81 is inserted at first into the substrate 20 to support the substrate 20 in parallel with the plane of a positive electrode 82 in an ion coater 80 . Subsequently, a shielding plate 85 is so arranged between the substrate 20 and a platinum foil (i.e., target) 84 disposed on a negative electrode 83 of the ion coater 80 as to cover only that portion (i.e., the portion above the portion L 1 in FIGS. 2 and 3) in the substrate 20 , on which the detecting electrode 26 is not formed. [0054] After the pressure of the residual gas in the ion coater 80 was set at about 8 Pa, a voltage is so applied for 5 minutes between the positive electrode 82 and the negative electrode 83 of the ion coater 80 as to make a current value of about 6 mA, so that ions 86 of the residual gas may collide against the platinum foil 84 to deposit nuclei 87 of the platinum atoms, as hit from the platinum foil 84 , on the substrate 20 . In order to deposit the platinum nuclei on the whole portion L 1 of the substrate 20 , however, the substrate 20 is turned for each deposition by 120 degrees on the support rod 81 , and this turn is repeated totally three times. [0055] When the nucleus applying step is thus ended, the manufacturing process transfers to a nucleus growing step of growing the nuclei, as deposited on the substrate 20 , by an electrolessly plating method. [0056] At this nucleus growing step, the substrate 20 is heated at first while being dipped in an aqueous solution of complex salt of platinum. Next, an aqueous solution of hydrazine (in concentration: 85 wt. %) is added to the aqueous solution of complex salt of platinum dipping the substrate 20 is added, and the substrate 20 is left to stand in the electrolessly plating liquid for 2 hours while being rocked, so that the platinum nuclei deposited on the substrate 20 may grow to form the detecting electrode 26 on the outer wall of the substrate 20 . Here, the concentration of the aqueous solution of complex salt of platinum is so adjusted that the thickness of the electrolessly plated platinum may have a thickness of 1.2 μm. [0057] In order to stabilize the detecting electrode 26 , moreover, a heat treatment is done at 1,200° C. for 1 hour, and spinel powder is applied by a plasma spray coating method to the surface of the detecting electrode 26 thereby to form a protective layer (although not shown). [0058] Subsequently, the reference electrode is formed on the substrate 20 . [0059] In order to form the reference electrode, the substrate 20 is left to stand while hydrofluoric acid (in concentration: 5 wt. %)being injected into the substrate 20 . And, the substrate 20 is rinsed by spraying water thereinto, and is then dried. [0060] Next, an aqueous solution of chloroplatinic acid (a platinum concentration: 0.5 g/m 3 ) is injected into the substrate 20 and is heated. After this, the chloroplatinic acid is discharged to form the coating film of an aqueous solution of chloroplatinic acid on the inner wall of the substrate 20 . Subsequently, an aqueous solution of hydrazine (in a concentration: 5 wt. %) is injected into the substrate 20 , and is heated to 75° C. and left to stand for 30 minutes thereby to deposit the nuclei of platinum on the inner wall of the substrate 20 . [0061] When the deposition of the nuclei is ended, the aqueous solution of chloroplatinic acid is discharged. An electrolessly plating liquid, which has been prepared by mixing an aqueous solution of complex salt of platinum (a platinum concentration: 15 g/m 3 ) and an aqueous solution of hydrazine (in a concentration: 85 wt. %), is injected into the substrate 20 , and is heated and left to stand so that the nuclei grow to form the reference electrode. [0062] And, the substrate 20 having the reference electrode formed therein is rinsed by spraying water into its inside, and is put into a driver so that it is sufficiently dried. [0063] Finally, the substrate 20 is aged in a combustion gas to activate the electrode so that the detecting element 2 is obtained. [0064] In the oxygen sensor 1 having the detecting element 2 thus manufactured, the sputtering method is used at the nucleus applying step when the detecting electrode 26 of the detecting element 2 is formed, so that the detecting electrode 26 formed after the nucleus growing step has a number of intergranules of crystals of platinum. In other words, the surface area (i.e., the surface area to act as a catalyst) of the detecting electrode 26 to contact with oxygen is larger than that of the prior art so that the catalyzing action of the detecting electrode 26 becomes higher than that of the prior art. Therefore, the oxygen sensor 1 can exhibit more excellent responding performances than that of the prior art. [0065] By the manufacturing process thus far described, moreover, the sizes of the nuclei are individually homogenized so that the detecting electrode 26 has a uniform thickness. Therefore, the oxygen sensor 1 exhibits a more excellent durability than that of the prior art. [0066] When the nuclei of platinum are to be deposited on the substrate of the detecting element 2 , moreover, the platinum nuclei can be prevented merely by arranging the shielding plate from being deposited on the substrate other than the portion L 1 , on which the detecting electrode 26 is to be formed. It is, therefore, possible to manufacture the oxygen sensor 1 without any trouble. [0067] In short, according to the manufacturing process of the invention, it is possible to manufacture the gas sensor, which is more excellent in the responding performances and the durable performances than the prior and which can form the electrode easily. [0068] According to the manufacturing process of this embodiment, moreover, the electrolessly plating method is used at the nucleus growing step when the detecting electrode 26 is formed. Therefore, the detecting electrode 26 can be formed more quickly than that, in which the nuclei are grown by continuing the sputtering from the nucleus applying step. Second Embodiment [0069] Here will be described a second embodiment. [0070] In the oxygen sensor of this embodiment, the detecting element 2 of the oxygen sensor 1 of the first embodiment is replaced by a detecting element 70 , as shown in FIGS. 5 and 6. [0071] Therefore, the following description is directed exclusively to the detecting element 70 . Here, FIG. 5 is a top plan view showing the exterior of the detecting element 70 , and FIG. 6 is a top plan view of the detecting element 70 on the back side of FIG. 5. [0072] Like the detecting element 2 , the detecting element 70 is constructed to include the substrate 20 , as shown in FIGS. 5 and 6. On the outer wall of the portion L 1 of the substrate 20 , moreover, there is formed such a long-size detecting electrode 71 upward of the substrate 20 from the upper portion at a distance L 2 from the bottom portion of the substrate 20 , as has a width W 3 smaller than the diameter at the portion L 1 of the substrate 20 and a length L 3 (L 3 <L 1 ). However, the outer wall of the portion L 1 of the substrate 20 is so coated with powder of spinel (although not shown) as to cover the detecting electrode 71 . [0073] In the detecting element 70 , as in the detecting element 2 , there is formed on the outer wall near the upper end portion of the substrate 20 a band-shaped terminal connecting portion 73 , which makes one round of the outer circumference of the substrate 20 thereby to connect the terminal fixture 50 . [0074] Between the detecting electrode 71 and the terminal connecting portion 73 , moreover, there is formed along the axial direction of the substrate 20 one long-size lead portion 72 , which has a width W 2 narrower than the detecting electrode 71 so that the detecting electrode 71 and the terminal connecting portion 73 are electrically connected therethrough. [0075] Here, the reference electrode (although not shown) of the detecting element 70 is formed, as in the detecting element 2 , all over the inner wall of the substrate 20 . [0076] The detecting element 70 thus constructed is so mounted in the oxygen sensor as to bring the heater 3 into contact with the inner circumference wall, as opposed to the detecting electrode 71 , of the substrate 20 . [0077] In order to manufacture the detecting element 70 , there may be a process similar to that for manufacturing the detecting element 2 . At the time of forming the detecting electrode 71 , however, there is arranged between the substrate 20 and the platinum foil disposed on the negative electrode of the ion coater a shielding plate, which has an area for covering the substrate 20 as a whole and which has such a through hole at a portion to form the detecting element 71 as has a planar shape congruent with the detecting electrode 71 . Unlike the first electrode, moreover, the sputtering is done for 5 minutes while leaving the substrate 20 to stand on the support rod. [0078] The oxygen sensor of this embodiment having the detecting element 70 thus constructed can attain effects like those of the oxygen sensor 1 of the first embodiment. In the detecting element 70 , moreover, the detecting electrode 71 is formed exclusively at the portion, in which the solid electrolyte is the most active and with which the heater contacts, of the detecting element 70 . Therefore, the oxygen sensor of this embodiment exhibits better responding performances than those of the oxygen sensor 1 of the first embodiment. EXAMPLES [0079] Here, we have performed experiments so as to demonstrate the effects of the oxygen sensors of the first and second embodiments thus far described. In these demonstration experiments: the responding performances and the performances of durability against the heat were compared by causing the oxygen sensor 1 having the detecting element 2 to belong to Example 1 , the oxygen sensor having the detecting element 70 to Example 2 , and the oxygen sensor having the detecting element (although not shown) of the prior art to Example 1. [0080] Here, the detecting element of the prior art is manufactured by using the process of the prior art but is set to have the shapes and sizes of the substrate and electrode absolutely like those of the detecting element 2 . [0081] In these demonstration experiments, the portion L 1 of the detecting elements 2 and 70 from the axial center to the bottom portion has a length set at 22.0 mm, and the lower portion and the upper portion of L 1 have diameters φ1 and φ2 set at 5.0 mm and 6.0 mm, respectively. Moreover, the lead portions 27 and 72 of the detecting elements 2 and 70 have their widths W 1 and W 2 set to 1.5 mm and have their thickness set to 10 μm. [0082] Moreover, the distance L 2 from the bottom portion of the detecting element 70 to the detecting electrode 71 is set at 2.0 mm, and the detecting electrode 71 has its length L 3 set at 20.0 mm. [0083] In both the detecting elements, on the other hand, the detecting electrodes have a thickness set to 1.2 μm, and the spinel coated on the portion L 1 has a thickness set at 200 μm. [0084] Here will be described the process of the prior art for manufacturing the detecting element. This manufacturing process of the prior art is absolutely similar to those of the first and second embodiments, excepting the nucleus applying step of forming the detecting electrode. [0085] In order to apply the nuclei to the detecting electrode, masking rubber is so mounted at first on the substrate as to cover the substrate excepting the portion to form the detecting electrode. Then, the substrate having the masking rubber mounted thereon is dipped in an aqueous solution of complex salt of platinum (a platinum concentration: 15 g/m 3 ). Subsequently, the aqueous solution of platinum complex salt dipping the substrate is heated to 60° C., and an aqueous solution of sodium borate is added. Moreover, the substrate is left to stand in this mixture liquid while being rocked, to deposit the nuclei of platinum on the outer wall of the substrate. [0086] After this nucleus deposition, moreover, the detecting element of the prior art is obtained through the nucleus growing step like that of the detecting elements 2 and 70 of the first and second embodiments. [0087] The results of our demonstration experiments are presented in FIG. 7 to FIG. 12. [0088] First of all, FIG. 7 to FIG. 9 are waveform diagrams of those outputs of the individual oxygen sensors, which were recorded when the aforementioned three oxygen sensors were sequentially mounted on the common internal combustion engine and when the A/F ratio of the internal combustion engine was alternately switched from lean to rich and from rich to lean for a period of 2 Hz. Here: FIG. 7 is the output waveform diagram of the oxygen sensor of Example 1; FIG. 8 is the output waveform diagram of the oxygen sensor of Example 2; and FIG. 9 is the output waveform diagram of the oxygen sensor of Comparison 1. [0089] Here in FIG. 7 to FIG. 9, reference letter T 1 designates the time period till the output of the oxygen sensor, as recorded just after the electric power was supplied to the heater of the oxygen sensor, acquires an amplitude to exceed a threshold value (e.g., 450 mV) at the boundary between the rich and the lean. And, reference letter T 2 designates the time period till the output of the oxygen sensor exceeds the threshold value at first just after the electric power was supplied to the heater of the oxygen sensor, reaches again the threshold value in accordance with the change in the A/F ratio of the internal combustion engine, and reaches a predetermined value (e.g., 550 mV) set higher than the threshold value. Here, the letter T 1 indicates the time period till the detecting element of the oxygen sensor is activated, and the letter T 2 indicates the time period till a stable output is obtained from the detecting element. [0090] In the oxygen sensors of Examples 1 and 2 according to the invention, as presented in FIG. 7 and FIG. 8, the time period T 1 had values of 7.6 seconds and 7.2 seconds, respectively, and the time period T 2 had values of 8.5 seconds and 8.0 seconds, respectively. In the oxygen sensor of Comparison 1, as presented in FIG. 9, on the contrary, the time periods T 1 and T 2 had values of 8.3 seconds and 9.2 seconds, respectively. [0091] From these results, it can be confirmed that the oxygen sensors of Examples 1 and 2 can be activated for shorter time periods to generate stable outputs quickly than the oxygen sensor of Comparison 1 manufactured by the process of the prior art. [0092] Next, FIG. 10 to FIG. 12 are waveform diagrams, which are recorded of the outputs of the aforementioned individual oxygen sensors against the change in the A/F ratio control signal for controlling the A/F ratio of the internal combustion engine. Here: FIG. 10 is the waveform diagram of the oxygen sensor 1 of Example 1; FIG. 11 is the waveform diagram of the oxygen sensor 1 of Example 2; and FIG. 12 is the waveform diagram of the oxygen sensor 1 of Comparison 1. [0093] Here in FIG. 10 to FIG. 12, reference letters TLS designate a time period till the outputs of the individual oxygen sensors exceed a threshold value after the A/F ratio control signal was switched from the lean to the rich, and reference letters TRS designate a time period till the outputs of the individual oxygen sensors fall below the threshold value after the A/F ratio control signal was switched from the rich to the lean. [0094] In the oxygen sensors of Examples 1 and 2, as presented in FIG. 10 and FIG. 11, the time period TLS had values of 0.323 seconds and 0.319 seconds, respectively, and the time period TRS had values of 0.307 seconds and 0.305 seconds, respectively. In the oxygen sensor of Comparison 1, as presented in FIG. 12, on the contrary, the time periods TLS had a value of 0.343 seconds, and the time period TRS had a value 0.324 seconds. [0095] From these results, it can be confirmed that the oxygen sensors of Examples 1 and 2 have quicker responses to the fluctuation in the oxygen concentration in the exhaust gas than the oxygen sensor of Comparison 1. [0096] From these results, it has been verified that the oxygen sensors of Examples 1 and 2 can exhibit satisfactory responding performances. [0097] Here, the aforementioned individual oxygen sensors were exposed for 2,000 hours to the exhaust gas at 1,000° C., and the changes in the outputs of the individual oxygen sensors were confirmed against the change in the A/F ratio control signal for controlling the A/F ratio of the internal combustion engine. [0098] As a result, the oxygen sensor of Comparison 1 was broken at the detecting electrode so that it did not generate no output. On the contrary, the responding time periods (TRS+TLS) of the oxygen sensors of Examples 1 and 2 were 0.661 seconds and 0.650 seconds, respectively. [0099] From these results, it has been verified that both the oxygen sensors of Examples 1 and 2 are neither broken in the detecting electrodes nor seriously changed in the responding performances even if they are exposed for a long time to the atmosphere at a high temperature, so that they have high durable performances against the heat. [0100] At the time of manufacturing the detecting elements individually, as used in the comparison experiments, the Inventors have measured the sizes of platinum crystals constructing the detecting electrodes. As a result, the platinum crystals constructing the detecting electrode had a size of about 0.2 to 0.3 μm. However, the detecting electrode 26 of the detecting electrode 2 and the detecting electrode 71 of the detecting element 70 had such fine platinum crystals as could not be found, even if observed by setting the magnitude of a scanning type electronic microscope (SEM) at 20,000 times. [0101] In short, according to the manufacturing process of the invention, the platinum crystals constructing the detecting electrode can be made fine. Therefore, the intergranules of the platinum crystals in the detecting electrode become so numerous that the surface area of the detecting electrode to contact with the exhaust gas can be made larger than that of the prior art. [0102] Although the invention has been described hereinbefore in connection the embodiments, it should not be limited thereto in the least but can naturally take a variety of modes so far as it belongs to the present invention. [0103] In the foregoing embodiments, for example, the invention has been applied to the manufacture of the oxygen sensor but may also be applied to the manufacture of another mode such as a nitrogen oxide (NO x ) sensor. [0104] In the foregoing embodiments, moreover, platinum was used to form the detecting electrodes or the reference electrodes but may also be replaced by rhodium, palladium, silver or gold. [0105] Moreover, the foregoing embodiments have used the DC glow discharge sputtering method at the nucleus applying step but may also use another sputtering method such as a magnetron sputtering method or an ion beam sputtering method, or a deposition method such as a vacuum evaporation method, a molecular beam deposition method, an ion plating method or an ion beam deposition method. [0106] In the foregoing embodiments, moreover, at the nucleus applying step for forming the detecting electrode 26 of the detecting element 2 , the substrate 20 is turned for every predetermined time periods. However, the nuclei of platinum may also be deposited by turning the substrate 20 at all times or by methods, as shown in FIG. 13 and FIG. 14. [0107] In the method shown in FIG. 13, more specifically, the nuclei of platinum are deposited by inserting the portion L 1 of the substrate 20 into a shielding plate 90 having a hole for inserting the portion L 1 of the substrate 20 thereinto and by fixing the substrate 20 in the ion coater 80 with its bottom portion being directed toward the negative electrode 83 . According to this method, the platinum nuclei can be deposited all over the portion L 1 of the substrate 20 without turning the substrate 20 . If the bottom portion of the substrate 20 is coated with a shielding cover 91 made of rubber or the like, as shown in FIG. 14, the platinum nuclei can be deposited exclusively on the outer wall of the portion L 1 of the substrate 20 excepting the bottom portion. [0108] This application is based on Japanese Patent application JP 2002-322627, filed Nov. 6, 2002, the entire content of which is hereby incorporated by reference, the same as if set forth at length.

A process for manufacturing a gas sensor including a detecting element having an electrode containing a precious metal formed on a surface of a solid electrolyte, comprising: a first step of applying a nuclei of a precious metal having a catalyzing action on a gas to be measured; and a second step of growing the nuclei, wherein the first step uses a physical vapor deposition method.

This is a Continuation of U.S. application Ser. No. 08/361,191, filed Apr. 18, 1995, now abandoned, which is a Divisional of Ser. No. 08/013,801 filed Feb. 2, 1993, now U.S. Pat. No. 5,420,019. BACKGROUND OF THE INVENTION The present invention provides novel bactericidal/permeability-increasing protein products and stable pharmaceutical compositions containing the same. Lipopolysaccharide (LPS), is a major component of the outer membrane of gram-negative bacteria and consists of serotype-specific O-side-chain polysaccharides linked to a conserved region of core oligosaccharide and lipid A. Raetz, Ann. Rev. Biochem., 59:129-170 (1990). LPS is an important mediator in the pathogenesis of gram-negative septic shock, one of the major causes of death in intensive-care units in the United States. Morrison, et al., Ann. Rev. Med. 38:417-432 (1987). LPS-binding proteins have been identified in various mammalian tissues. Morrison, Microb. Pathol., 7:389-398 (1989); Roeder, et al., Infect., Immun., 57:1054-1058 (1989). Among the most extensively studied of the LPS-binding proteins is bactericidal/permeability-increasing protein (BPI), a basic protein found in the azurophilic granules of polymorphonuclear leukocytes. Human BPI protein has been isolated from polymorphonuclear neutrophils by acid extraction combined with either ion exchange chromatography Elsbach, J. Biol. Chem., 254:11000 (1979)! or E. coli affinity chromatography Weiss, et al., Blood, 69:652 (1987)! and has potent bactericidal activity against a broad spectrum of gram-negative bacteria. While the BPI protein is cytotoxic against many gram-negative bacteria, it has no reported cytotoxic activity toward gram-positive bacteria, fungi, or mammalian cells. The amino acid sequence of the entire human BPI protein, as well as the DNA encoding the protein, have been elucidated in FIG. 1 of Gray, et al., J. Biol. Chem., 264:9505 (1989), incorporated herein by reference (SEQ ID NOs: 1 and 2). The Gray et al. publication discloses the isolation of human BPI-encoding cDNA from a cDNA library derived from DMSO-induced cells of the human promyelocytic leukemia HL-60 cell line (ATTC CCL 240). Multiple PCR amplifications of DNA from a freshly prepared cDNA library derived from such DMSO-induced HL-60 cells have revealed the existence of human BPI-encoding cDNAs wherein the codon specifying valine at amino acid position 151 is either GTC (as set out in SEQ ID No: 1) or GTG. Moreover, cDNA species employing GTG to specify valine at position 151 have also been found to specify either lysine (AAG) for the position 185 amino acid (as in SEQ ID Nos: 1 and 2) or a glutamic acid residue (GAG) at that position. A proteolytic fragment corresponding to the N-terminal portion of human BPI holoprotein possesses the antibacterial efficacy of the naturally-derived 55 kDa human BPI holoprotein. In contrast to the N-terminal portion, the C-terminal region of the isolated human BPI protein displays only slightly detectable anti-bacterial activity. Ooi, et al., J. Exp. Med., 174:649 (1991). A BPI N-terminal fragment, comprising approximately the first 199 amino acids of the human BPI holoprotein, has been produced by recombinant means as a 23 kD protein. Gazzano-Santoro et al., Infect. Immun. 60:4754-4761 (1992). The projected clinical use of BPI products for treatment of gram-negative sepsis in humans has prompted significant efforts to produce large quantities of recombinant BPI (rBPI) products suitable for incorporation into stable, homogeneous pharmaceutical preparations. For example, co-owned, co-pending U.S. patent application Ser. No. 07/885,501 by Grinna discloses novel methods for the purification of recombinant BPI products expressed in and secreted from genetically transformed mammalian host cells in culture. Efficacy of the purification processes is therein demonstrated in the context of products of transformed CHO cells which express DNA encoding the 31 amino acid "leader" sequence of human BPI and the initial 199 amino terminal residues of the mature protein (i.e. corresponding to the amino acids -31 through 199 of SEQ ID NO: 2). Co-owned, co-pending U.S. patent application Ser. No. 07/885,911 by Theofan, et al. is directed to novel, recombinant-produced BPI protein analog products resulting from the expression of DNA encoding the BPI leader sequence and either 191 or 199 amino terminal residues of human BPI fused to DNA encoding a constant region of an immunoglobulin heavy chain. Efforts to produce pharmaceutical grade BPI products for treatment of gram negative sepsis in humans have not yielded uniformly satisfactory results. A principal reason for this is the nature of the amino acid sequence of human BPI and the nature of the recombinant host cell environment in which the products are produced. As one example, biologically-active rBPI products comprising the initial 199 residues of BPI rBPI(1-199)! produced as secretory products of transfected CHO host cells may be purified in good yields. However, the isolated BPI products initially include dimeric forms of BPI as well as cysteine adduct species. Moreover, BPI products may be unstable upon storage at physiological temperature and pH, resulting in the formation of additional dimeric and adduct species. Such dimeric and adduct species, while retaining biological activity, are not preferred for incorporation into pharmaceutical preparations projected for human use. Dimer formation and the formation of cysteine adducts are the probable result of the fact that BPI includes three cysteine amino acid residues, all of which are positioned within the biologically active amino terminal region of BPI, i.e., at positions 132, 135 and 175. Formation of a single disulfide bond between two of the three cysteines allows for dimer formation or formation of cysteine adducts with the remaining free cysteine in the host cell cytoplasm and/or the cell culture supernatant. Even monomeric rBPI products display varying degrees of microheterogeneity in terms of the number of carboxy terminal residues present in such products. For example, it is difficult to detect full-length expression product in a medium containing host cells transformed or transfected with DNA encoding rBPI(1-199). Instead, the expression products obtained from such cells represent an heterogeneous array of carboxy-terminal truncated species of the rBPI N-terminal fragment. In fact, the expected full-length product (1-199) is often not detected as being among the rBPI species present in that heterogeneous array. Heterogeneity of the carboxy terminal amino acid sequence of rBPI(1-199) products appears to result from activity of carboxypeptidases in host cell cytoplasm and/or culture supernatant. An additional problem encountered in the preparation of pharmaceutical-grade BPI products is the formation of macroscopic particles which decrease the homogeneity of the product, as well as decreasing its activity. A preferred pharmaceutical composition containing rBPI products according to the invention comprises the combination of a poloxamer (polyoxypropylene-polyoxyethylene block copolymer) surfactant and a polysorbate (polyoxyethylene sorbitan fatty acid ester) surfactant. Such combinations are taught in a co-owned, co-pending, concurrently-filed U.S. Patent Application, to have synergistic effects in stabilizing pharmaceutically-active polypeptides against particle formation. Most preferred is a composition in which the rBPI product is present in a concentration of 1 mg/ml in citrate buffered saline (0.02M citrate, 0.15M NaCl, pH 5.0) comprising 0.1% by weight of poloxamer 188 (Pluronic F-68, BASF Wyandotte, Parsippany, N.J.) and 0.002% by weight of polysorbate 80 (Tween 80, ICI Americas Inc., Wilmington, Del.). There continues to be a need in the art for improved rBPI products suitable for incorporation into stable homogeneous pharmaceutical preparations. Such products would ideally be obtainable in large yield from transformed host cells, would retain the bactericidal and LPS-binding biological activities of BPI, and would be limited in their capacity to form dimeric species and cysteine adducts, and would be characterized by limited variation in carboxy termini. SUMMARY OF THE INVENTION The present invention provides novel, biologically-active, recombinant-produced BPI ("rBPI") protein and protein fragment products which are characterized by a resistance to dimerization and cysteine adduct formation, making such products highly suitable for pharmaceutical use. Also provided are rBPI products characterized by decreased molecular heterogeneity at the carboxy terminus. Novel DNA sequences encoding rBPI products and analog products, plasmid vectors containing the DNA, host cells stably transformed or transfected with the plasmids, recombinant preparative methods, stable pharmaceutical compositions and treatment methods are also provided by the invention. According to one aspect of the present invention, rBPI protein analogs are provided which comprise a BPI N-terminal fragment wherein a cysteine at amino acid position 132 or 135 is replaced by another amino acid, preferably a non-polar amino acid such as serine or alanine. In a preferred embodiment of the invention, the cysteine residue at position 132 of a polypeptide comprising the first 199 N-terminal residues of BPI is replaced by an alanine residue in a recombinant product designated "rBPI(1-199)ala 132 ". Also in a preferred embodiment of the invention, the cysteine at position 135 of a BPI fragment comprising the first 199 N-terminal BPI residues is replaced by a serine, resulting in a recombinant product designated "rBPI(1-199)ser 135 ". Highly preferred is a recombinant product designated "rBPI(1-193)ala 132 " which is characterized by decreased heterogeneity in terms of the identity of its carboxy terminal residue. Also in a preferred embodiment of the invention, a polypeptide is taught which comprises the first 193 amino-terminal residues of BPI and which has a stop codon immediately following the codon for leucine at position 193. According to another aspect of the invention, DNA sequences are provided which encode the above-described rBPI protein and protein fragment products, including analog products. Such DNA sequences may also encode the 31-residue BPI leader sequence and the BPI polyadenylation signal. Also provided are autonomously-replicating DNA plasmid vectors which include DNA encoding the above-mentioned products and analogs as well as host cells which are stably transformed or transfected with that DNA in a manner sufficient to allow their expression. Transformed or transfected host cells according to the invention are of manifest utility in methods for the large-scale production of rBPI protein products of the invention. The invention also contemplates rBPI protein analog products in the form of fusion proteins comprising, at the amino terminal, rBPI protein analog products of the invention and, at the carboxy terminal, a constant region of an immunoglobulin heavy chain or an allelic variant thereof. Natural sequence BPI/immunoglobulin fusion proteins are taught in the co-pending, co-owned U.S. patent application Ser. No. 07/885,911 by Theofan, et al., the disclosures of which are incorporated herein by reference. The invention further contemplates methods for producing the aforementioned fusion proteins. Also within the scope of the present invention are DNA sequences encoding biologically-active rBPI protein fragment products having from about 176 to about 198 of the N-terminal amino acids of BPI. These DNAs allow for production of BPI products in eukaryotic host cells, such as CHO cells, wherein the products display less heterogeneity in terms of the carboxy terminal residues present. Presently preferred are DNAs encoding 193 N-terminal residues of BPI (e.g., DNAs encoding the thirty-one amino acid leader sequence of BPI, the initial 193 N-terminal amino acids, and one or more stop codons). Most preferred are such DNAs which additionally encode proteins wherein the cysteine at either position 132 or 135 is replaced (e.g, rBPI(1-193)ala 132 ). Finally, the present invention also provides stable, homogeneous pharmaceutical compositions comprising the rBPI protein products of the invention in pharmaceutically acceptable diluents, adjuvants, and carriers. Such pharmaceutical compositions are resistant to the formation of rBPI product particles. Such compositions are useful in the treatment of gram-negative bacterial infection and the sequelae thereof, including endotoxin-related shock and one or more conditions associated therewith, such as disseminated intravascular coagulation, anemia, thrombocytopenia, leukopenia, adult respiratory distress syndrome, renal failure, hypotension, fever, and metabolic acidosis. Numerous additional aspects and advantages of the invention will become apparent to those skilled in the art upon considering the following detailed description of the invention which describes presently preferred embodiments thereof. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 represents results of SDS-PAGE analysis of rBPI(1-199) products. FIGS. 2a and 2B represents results of SDS-PAGE analysis of rBPI(1-193) and rBPI(1-199)ala 132 products. FIG. 3 depicts results of cation exchange HPLC analysis of rBPI(1-199) products. FIG. 4 shows results of cation exchange HPLC analysis of rBPI(1-199)ala 132 products. FIG. 5 represents results of reverse phase HPLC run on rBPI(1-199) products. FIG. 6 represents results of reverse phase HPLC run on rBPI(1-199)ala 132 products. FIG. 7 presents results of turbidity studies on pharmaceutical compositions containing rBPI products with and without poloxamer/polysorbate surfactant ingredients at pH 7.0 and 57° C. DETAILED DESCRIPTION The following detailed description relates to the manufacture and properties of various rBPI product preparations which comprise an amino acid substitution at a cysteine residue and/or highly uniform carboxy termini. More specifically, Example 1 relates to an exemplary means by which base substitutions are introduced in the nucleotide sequence encoding an exemplary N-terminal fragment of the BPI protein and to the incorporation of such mutated sequences into plasmid vectors. Example 2 addresses the incorporation of vectors of Example 1 into appropriate host cells and further describes the expression of recombinant BPI protein polypeptide products of the invention. Example 3 relates to construction of BPI protein encoding cysteine replacement analog products of the invention and the use thereof in in vitro transcription/translation procedures. Example 4 relates to properties of rBPI product polypeptides of the invention. EXAMPLE 1 Construction Of Vectors Containing BPI Cysteine Replacement Analogs A. Construction Of Plasmids pING4519 And pING4520 The expression vector, pING4503, was used as a source of DNA encoding a recombinant expression product designated rBPI(1-199), i.e., encoding a polypeptide having the 31-residue signal sequence and the first 199 amino acids of the N-terminus of the mature human BPI, as set out in SEQ ID NOs: 1 and 2 except that valine at position 151 is specified by GTG rather than GTC and residue 185 is glutamic acid (specified by GAG) rather than lysine (specified by AAG). Plasmid pING4503 has been described in co-pending, co-owned U.S. patent application Ser. No. 07/885,911 by Theofan, et al. which is incorporated herein by reference with respect to the background of the invention. Briefly, the construction of pING4503 is based on plasmid pING2237N which contains the mouse immunoglobulin heavy chain enhancer element, the LTR enhancer-promoter element from Abelson murine leukemia virus (A-MuLv) DNA, the SV40 19S/16S splice junction at the 5' end of the gene to be expressed, and the human genomic gamma-1 polyadenylation site at the 3' end of the gene to be expressed. Plasmid pING2237N also has a mouse dihydrofolate reductase (DHFR) selectable marker. The DNA encoding rBPI(1-199), including 30 bp of the natural 5' untranslated region and bases encoding the 31 amino acid signal sequence, as well as 199 N-terminal amino acids of BPI, is inserted between unique SalI and SstII restriction sites in pING4503. Two vectors, pING4519 and pING4520, were constructed based on pING4503 for expression of rBPI(1-199) cysteine replacement analogs in which one of the three naturally-occurring cysteine residues of BPI was replaced with another amino acid. A PvuII site (CAGCTG) which occurs only once in the DNA encoding rBPI(1-199), and which is located between cysteine 132 and cysteine 135, was utilized in these constructions. Because several additional PvuII sites exist in pING4503, it was first necessary to isolate the SalI-SstII fragment which contained the insert encoding rBPI(1-199) from pING4503 by digesting with SalI and SstII. The purified SalI-SstII rBPI(1-199) insert was then digested with PvuII, resulting in an approximately 529 bp SalI-PvuII fragment and an approximately 209 bp PvuII-SstII fragment, each of which was purified separately. Plasmid pING4519 is identical to pING4503 except that pING4519 contains a DNA insert encoding an rBPI(1-199) in which a codon for alanine is substituted for the codon specifying the native cysteine at position 132. As noted above, the recombinant product resulting from host cell expression and secretory processing of such an insert is referred to as "rBPI(1-199)ala 132 ". In order to generate pING4519, BPI DNA sequences were PCR amplified from pING4503 using the primers BPI-6: AAGCTTGTCGACCAGGCCTTGAGGT (SEQ ID NO: 3), which incorporated a SalI restriction site at the 5' end of the 30 bp BPI untranslated region, and BPI-14: CTGGAGGCGGTGATGGTG (SEQ ID NO: 4), which incorporated one half of the PvuII site and the base substitutions necessary to code for alanine at position 132. PCR amplification was accomplished using the GeneAmp PCR kit (Perkin Elmer Cetus, Norwalk, Conn.) according to the manufacturer's instructions. The resulting PCR fragment was digested with SalI, resulting in an approximately 529 bp SalI-blunt fragment which was then used in a three-piece ligation, together with the approximately 209 bp PvuII-SstII fragment described above and the large fragment resulting from SalI and SstII digestion of pING4503, to generate pING4519. Plasmid pING4520 is identical to pING4519 with the exception that pING4520 contains a DNA insert encoding an rBPI(1-199) analog in which a serine codon is substituted for the codon specifying the native cysteine at position 135. As noted above, the recombinant product resulting from host cell expression of such an insert is designated "rBPI(1-199) ser 135 ". In order to generate pING4520, BPI DNA sequences were PCR amplified from pING4513, a plasmid essentially similar to pING4503 except that the selection marker is gpt instead of DHFR and the cDNA insert encodes the signal sequence and full-length BPI (456 residues) instead of only the rBPI(1-199) portion. Amplification by PCR was accomplished using primer BPI-15: CTCCAGCAGCCACATCAAC (SEQ ID NO: 5), wherein the 5' end incorporates one half of a mutated PvuII site (wherein "CTG" is changed to "CTC") and the base substitutions necessary to code for serine at position 135; and primer BPI-7: GAACTTGGTTGTCAGTCG (SEQ ID NO: 6), representing rBPI-encoding sequences located downstream of the region encoding BPI residue 199. This PCR fragment was digested with BstBI, which cuts downstream of the cysteine 135 mutagenesis site, and the resulting approximately 100 bp blunt-BstBI fragment was gel purified. A three piece ligation was then performed with the 529 bp SalI-PvuII BPI restriction fragment described above, the 100 bp blunt-BstBI fragment, and a large fragment resulting from BstBI-SalI digestion of pING4503, to generate pING4520. B. Construction Of Plasmid pING4530 Another vector, pING4530, was constructed which contained the alanine-for-cysteine replacement as in pING4519, but which contained the gpt selectable marker (allowing for mycophenolic acid resistance) instead of the DHFR marker carried over from pING4503 to pING4519. To construct pING4530, a 1629 bp SalI-DraIII restriction fragment was isolated from pING4519. This fragment included all of the rBPI(1-199)ala 132 coding region as well as an additional approximately 895 bp vector sequence at the 3' end of the coding region. This fragment was ligated to the large (approximately 7230 bp) DraIII-SalI vector fragment isolated from pING4513 to generate pING4530. C. Construction Of Plasmid pING4533 Plasmid pING4533 was constructed for expression of rBPI(1-199)ala 132 , wherein the codon specifying the fifth amino acid of the BPI signal sequence, methionine (ATG), at position -27 was placed in the context of the consensus Kozak translation initiation sequence GCCACCRCCATGG (SEQ ID NO: 7) Kozak, Nucl. Acid. Res., 15:8125 (1987)!, and in which the DNA sequence encoding the first 4 amino acids of the BPI signal was removed. This was accomplished by PCR amplification of BPI sequences from a plasmid containing the full length human BPI cDNA in pGEM-7zf(+)! using the PCR primer BPI-23: ACTGTCGACGCCACCATGGCCAGGGGC (SEQ ID NO: 8), incorporating a SalI restriction site and the nucleotides GCCACC in front of the ATG (methionine) at position -27 of the BPI signal, and the primer BPI-2: CCGCGGCTCGAGCTATATTTTGGTCAT (SEQ ID NO: 9), corresponding to the 3' end of the rBPI(1-199) coding sequence. The approximately 700 bp PCR amplified DNA was digested with SalI and EcoRI and the resulting 270 bp fragment, including approximately the first one-third of the BPI(1-199) coding sequence, was purified. This SalI-EcoRI fragment was ligated to 2 other fragments: (1) a 420 bp EcoRI-SstII fragment from pING4519, encoding the remainder of BPI(1-199) wherein alanine replaces cysteine at position 132; and (2) an approximately 8000 bp SstII-SalI vector fragment from pING4502 (a vector essentially similar to pING4503 except that it does not include the 30 bp 5' untranslated sequence and has a gpt marker rather than DHFR), to generate pING4533 which contains a gpt marker. D. Construction Of Plasmids pING4221, pING4222, And pING4223 Vectors similar to pING4533 were constructed having an insert which contained the optimized Kozak translation initiation site corresponding to methionyl residue -27 of the signal sequence, and an alanine-for-cysteine replacement at position 132. However, the BPI fragment coding sequence terminated at residue 193 in these constructions. As noted above, the recombinant product resulting from host cell expression of this DNA is referred to as "rBPI(1-193)ala 132 ". Vectors containing these inserts were made by first digesting pING4533 with SalI, which cuts at the 5' end of the BPI DNA insert, and AlwNI, which leaves a three bp 3'-overhang at residue 192. The resulting approximately 700 bp fragment was then purified. This fragment was re-ligated into the large fragment resulting from pING4533 digestion with SstII-SalI, along with two annealed complementary oligonucleotides, BPI-30: CTGTAGCTCGAGCCGC (SEQ ID NO: 10) and BPI-31: GGCTCGAGCTACAGAGT (SEQ ID NO: 11). This replaced the region between the AlwNI and SstII sites with the codon for residue 193 (leucine), a stop codon, and an XhoI restriction site 5' to the SstII site and resulted in regeneration of both the AlwNI and the SstII sites and placement of the stop codon, TAG, immediately after the codon (CTG) for amino acid 193 (leucine). The resultant plasmid was designated pING4223 and had the gpt marker. Similar constructions were made exactly as described for pING4223 except that different SstII-SalI vector fragments were used to generate vectors with different selection markers. For example, pING4221 is identical to pING4223 except that it contains the his marker (conferring resistance to histidinol) instead of gpt and pING4222 is identical to pING4223 except that it contains the DHFR marker instead of gpt. E. Construction Of Plasmids pING4537, pING4143, pING4146, pING4150, And pING4154 A series of vectors was constructed which contained an insert encoding rBPI(1-193)ala 132 , the optimized Kozak translation initiation site, and different selection markers essentially identical to those described with respect to pING4221, pING4222 and pING4223 except that the human genomic gamma-1 heavy chain polyadenylation and transcription termination region at the 3' end of the SstII site was replaced with a human light chain polyadenylation sequence followed by mouse light chain (kappa) genomic transcription termination sequences. In collateral gene expression studies, the light chain polyadenylation signal and transcription termination region appeared to be responsible for 2.5-5 fold increases in BPI expression levels in Sp2/0 and CHO-K1 cells. The aforementioned vectors were constructed by first constructing pING4537, a vector similar to pING4533 which contains the rBPI(1-199)ala 132 insert. However, pING4537 includes the human light chain polyadenylation sequences instead of the human heavy chain sequence. The mouse kappa 3' sequences were obtained from pING3170, an expression vector which encodes a human light chain cDNA and includes a mouse genomic light chain 3' transcription termination sequence. This was accomplished by digesting with SstI, which cuts 35 bp upstream of the mouse light chain stop codon, treating with T4 DNA polymerase to make the end blunt, then cutting with BamHI, and purifying an approximately 1350 bp fragment which includes the mouse kappa 3' sequences. The resulting fragment consists of approximately 250 bp of the 3' portion of the human light chain constant region cDNA and the polyadenylation signal followed by a BamHI linker as described in the construct called Δ8 in Lui et al., J. Immunol. 139: 3521, (1987). The remainder of the approximately 1350 bp fragment consists of a BglII-BamHI mouse kappa 3' genomic fragment fragment "D" of Xu et al., J. Biol. Chem. 261:3838, (1986)! which supplies transcription termination sequences. This fragment was used in a 3-piece ligation with two fragments from pING4533: a 3044 bp fragment which includes all of BPI insert and part of vector obtained by digestion with SstII, T4 polymerase treatment, and NotI digestion (which includes all of BPI insert and part of vector), and an approximately 4574 bp BamHI-NotI fragment. The resulting vector, pING4537, is identical to pING4533 with the exception of the above-noted differences in the genomic 3' untranslated region. Additional vectors containing the kappa 3' untranslated sequences were constructed using pING4537 as the source of the kappa 3' fragment. The kappa 3' untranslated sequences were isolated by digestion of pING4537 with XhoI (a unique site which occurs immediately after the BPI stop codon) and BamHI. The resulting approximately 1360 bp XhoI-BamHI fragment was used in a series of 3-piece ligations to generate the following four vectors, all of which have inserts encoding rBPI(1-193)ala 132 and which have the optimized Kozak translation initiation site at residue -27 of the signal: (1) pING4143 (gpt marker), obtained by ligating a pING4223 4574 bp BamHI-NotI fragment (gpt marker), a pING4223 NotI-XhoI BPI insert-containing fragment of approximately 3019 bp, and the pING4537 XhoI-BamHI fragment; (2) pING4146 (DHFR marker), obtained by ligating a pING4222 approximately 4159 bp BamHI-NotI fragment (DHFR marker), a pING4223 NotI-XhoI BPI insert-containing fragment of approximately 3019 bp, and the pING4537 XhoI-BamHI fragment; (3) pING4150 (his marker), obtained by ligating a pING4221 his-containing approximately 4772 bp BamHI-NotI fragment, a pING4222 NotI-XhoI BPI insert-containing fragment, and the pING4537 XhoI-BamHI fragment; and (4) pING4154 (neo marker), obtained by ligating a pING3174 neo-containing approximately 4042 bp BamHI-BsaI fragment, a pING4221 BsaI-XhoI BPI insert-containing fragment of approximately 3883 bp and the pING4537 XhoI-BamHI fragment. Plasmid pING3174 contains an insert encoding antibody heavy chain DNA and has a neo marker. The neo gene and its flanking sequences were obtained from the pSv2 neo plasmid reported by Southern et al., J. Mol. Appl. Genet., 1:327 (1982). F. Construction Of Plasmids pING4144 And pING4151 Two plasmids were constructed, pING4144 and pING4151, which were identical to pING4143 and pING4150, respectively, except that expression of rBPI coding sequences was under control of the human cytomegalovirus (hCMV) immediate early enhancer/promoter instead of the Abelson murine leukemia virus (A-MuLv) LTR promoter. Therefore, both pING4144 and pING4151 contained the mutation of the cysteine at position 132 to alanine, the optimized Kozak translation initiation sequence, and the human light chain poly-A/mouse kappa genomic transcription termination region. The region between nucleotides 879 and 1708 of the original vectors (pING4143 and pING4150) was replaced with a region of the hCMV enhancer/promoter corresponding to nucleotides -598 through +174 as shown in FIG. 3 of Boshart et al., Cell 41:521 (1985), incorporated herein by reference. To introduce the hCMV promoter region into BPI expression vectors, plasmid pING4538 was first constructed by replacing the approximately 1117 bp EcoRI-SalI/A-MuLv promoter-containing fragment of pING4222 with an approximately 1054 bp EcoRI-SalI/hCMV promoter-containing fragment from plasmid pING2250 which contains the hCMV promoter driving expression of an antibody light chain insert. To construct pING4144, three fragments were ligated together: (1) the approximately 2955 bp rBPI(1-193)-containing NotI-XhoI fragment from pING4538; (2) the approximately 1360 bp XhoI-BamHI fragment from pING4537; and (3) the approximately 4770 bp BamHI-NotI fragment containing the his gene from pING4221. G. Construction Of Plasmids pING4145, pING4148 And pING4152 Plasmids pING4145, pING4148 and pING4152 were constructed and were identical to pING4143, pING4146, and pING4150, respectively, except that they contained the wild-type (natural sequence) cysteine at position 132 instead of an alanine substitution. Thus, all three contained the rBPI(1-193) insert, the optimized Kozak translation initiation sequence and the human light chain Poly A/mouse kappa genomic transcription termination region. These three plasmids were constructed as follows. To construct pING4145, three fragments were ligated together: (1) the approximately 3000 bp NotI-XhoI BPI(1-193) containing fragment from pING4140 (pING4140 is identical to pING4221 except that it contains the wild-type cysteine at Position 132); (2) the approximately 1360 bp XhoI-BamHI fragment from pING4537; and (3) the approximately 4570 bp BamHI-NotI fragment containing the gpt gene from pING4223. To construct pING4148, three fragments were ligated together: (1) the NotI-XhoI fragment from pING4140; (2) the XhoI-BamHI fragment from pING4537; and (3) the approximately 4150 bp BamHI-NotI fragment containing the DHFR gene from pING4222. To construct pING4152, three fragments were ligated together: (1) the approximately 3000 bp NotI-XhoI fragment from pING4142 (pING4142 is identical to pING4223 except that it contains the wild-type cysteine at 132); (2) the XhoI-BamHI fragment from pING4537; and (3) the approximately 4770 bp BamHI-NotI fragment containing the his gene from pING4221. Table 1, below, summarizes the content of the plasmids whose preparation is described in Sections A through G above. TABLE I__________________________________________________________________________PlasmidBPI Product Signal Seq. Marker 3' Terminal Promoter__________________________________________________________________________pING4519(1-199)Ala.sup.132 31AA DHFR* Human Genomic A-MuLv HC Gamma-1 Poly-ApING4520(1-199)Ser.sup.135 31AA DHFR* Human Genomic A-MuLv HC Gamma-1 Poly-ApING4530(1-199)Ala.sup.132 31AA gpt Human Genomic A-MuLv HC Gamma-1 Poly-ApING4533(1-199)Ala.sup.132 Kozak initiation gpt Human Genomic A-MuLv Seq; 27AA signal HC Gamma-1 Poly-ApING4223(1-193)Ala.sup.132 Kozak initiation gpt Human Genomic A-MuLv Seq; 27AA signal HC Gamma-1 Poly-ApING4221(1-193)Ala.sup.132 Kozak initiation his Human Genomic A-MuLv Seq; 27AA signal HC Gamma-1 Poly-ApING4222(1-193)Ala.sup.132 Kozak initiation DHFR Human Genomic A-MuLv Seq; 27AA signal HC Gamma-1 Poly-ApING4537(1-199)Ala.sup.132 Kozak initiation gpt Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4143(1-193)Ala.sup.132 Kozak initiation gpt Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4146(1-193)Ala.sup.132 Kozak initiation DHFR Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4150(1-193)Ala.sup.132 Kozak initiation his Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4144(1-193)Ala.sup.132 Kozak initiation gpt Human Kappa hCMV Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4145(1-193) Kozak initiation gpt Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4148(1-193) Kozak initiation DHFR Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4152(1-193) Kozak initiation his Human Kappa A-MuLv Seq; 27AA Signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4151(1-193)ala.sup.132 Kozak initiation his Human Kappa hCMV Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription TerminationpING4154(1-193)ala.sup.132 Kozak initiation neo Human Kappa A-MuLv Seq; 27AA signal Poly-A/Mouse Kappa Genomic Transcription Termination__________________________________________________________________________ *An altered DHFR gene as described in copending, coowned U.S. patent application, Ser. No. 07/885,911, incorporated herein by reference. EXAMPLE 2 Transfection Of Cells For Expression Of The rBPI Cysteine Replacement Analogs Mammalian cells are preferred hosts for production of rBPI protein analogs according to the invention because such cells allow for proper secretion, folding, and post-translational modification of expressed proteins. Presently preferred mammalian host cells for production of analogs of the invention include cells of fibroblast and lymphoid origin, such as: CHO-K1 cells (ATCC CCL61); CHO-DG44 cells, a dihydrofolate reductase deficient DHFR - ! mutant of CHO Toronto obtained from Dr. Lawrence Chasin, Columbia University; CHO-DXB-11, a DHFR - mutant of CHO-K1 obtained from Dr. Lawrence Chasin; Vero cells (ATCC CRL81); Baby Hamster Kidney (BHK) cells (ATCC CCL10); Sp2/O-Ag14 hybridoma cells (ATCC CRL1581); and NSO myeloma (ECACC No. 85110503). Transfection of mammalian cells may be accomplished by a variety of methods. A common approach involves calcium phosphate precipitation of expression vector DNA which is subsequently taken up by host cells. Another common approach, electroporation, causes cells to take up DNA through membrane pores created by the generation of a strong electric field (Sambrook et al., Molecular Cloning, A Laboratory Manual, Cold Spring Laboratory Harbor Press, 16.30-16.31 (1989)!. Selection for transfected cells is facilitated by incorporation in the expression vector of a gene whose product allows the transfected cells to survive and grow under selective conditions. A number of such genes have been identified. These include, among others: (1) neo, a prokaryotic gene which encodes resistance to the aminoglycoside antibiotic G418; (2) E. coli guanine phoshporibosyl transferase (gpt), which encodes resistance to mycophenolic acid (MPA) in the presence of xanthine, Mulligan et al., Proc. Nat. Acad. Sci. USA, 78:2072-2076 (1981)!; (3) dihydrofolate reductase (DHFR), which allows for growth of DHFR cells in the absence of nucleosides and gene amplification in the presence of increasing concentration of methotrexate; (4) the hisD gene of Salmonella typhimurium which allows growth in the presence of histidinol Hartman et al., Proc. Nat. Acad. Sci. USA, 85:8047-8051, (1988)!; (5) the trpB gene of E. coli Hartman et al., Proc. Nat. Acad. Sci. USA, 85:8047-8051, (1988)!, which allows growth in the presence of indole (without tryptophan); and (6) the glutamine synthetase gene, which allows growth in media lacking glutamine. The availability of these selective markers, either alone or in various combinations, provides flexibility in the generation of mammalian cell lines which express recombinant products at high levels. A. Transfection of CHO-K1 Cells with pING4533 Plasmid pING4533 contains gene sequences encoding rBPI(1-199)ala 132 fused to the A-MuLv promoter, the optimized Kozak translation initiation sequence, the human gamma-1 heavy chain 3' untranslated region, and the gpt marker for selection of MPA-resistant cells. The CHO-K1 cell line is maintained in Ham's F12 medium plus 10% fetal bovine serum (FBS) supplemented with glutamine/penicillin/streptomycin (Irvine Scientific, Irvine, Calif.). The cells were transfected by electroporation with 40 μg of pING4533 DNA which was first digested with NotI, extracted with phenol-chloroform and ethanol precipitated. Following electroporation, the cells were allowed to recover for 24 hours in non-selective Ham's F12 medium. The cells were then trypsinized, resuspended at a concentration of 5×10 4 cells/ml in Ham's F12 medium supplemented with MPA (25 μg/ml) and xanthine (250 μg/ml) and then plated at 10 4 cells/well in 96-well plates. Untransfected CHO-K1 cells are unable to grow in this medium due to the inhibition of pyrimidine synthesis by MPA. At 2 weeks, colonies consisting of transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of BPI-reactive protein by anti-BPI ELISA using rBPI(1-199) as a standard. In this assay, Immulon-II 96-well plates (Dynatech, Chantilly, Va.) were pre-coated with affinity purified rabbit anti-rBPI(1-199) antiserum. Supernatant samples were added and detection was carried out using affinity purified, biotinylated rabbit anti-rBPI(1-199) antiserum and peroxidase-labeled avidin. Approximately 800 colonies were screened in this manner. Thirty-one colonies having the highest production were transferred to 24-well plates for productivity assessment. Cells were grown to confluence in a 24-well plate in Ham's F12 medium supplemented with 10% FBS. Once the cells reached confluence, the Ham's F12 medium was removed and 1 ml of HB-CHO serum free medium (Irvine Scientific) plus 40 μl of sterile S-sepharose beads (Pharmacia, Piscataway, N.J.) was added as in co-owned, co-pending U.S. patent application, Ser. No.07/885,501 by Grinna. The cells were then incubated for 7 days after which the S-sepharose beads were removed and washed with 0.1M NaCl in 10 mM Tris buffer (pH7.5). The product was eluted from the beads by addition of 1.0M NaCl in Tris buffer and quantitated by ELISA as described above. The top-producing transformant, designated A153, secreted approximately 3 μg/ml in this assay and was adapted to growth in Excell 301 serum-free medium (JRH Scientific, Lenexa, Kans.). The adapted cells were grown in 1.5 L fermenters in Excell 301 medium in the presence of S-sepharose beads. Productivity was assessed at 120-140 hours by C4 HPLC analysis of product eluted from S-sepharose beads (50 ml aliquots). The productivity was 15-25 μg/L at these stages of the fermentation. B. Transfection Of CHO-DG44 Cells With pING4222 Plasmid pING4222 contains DNA encoding the rBPI(1-193)ala 132 analog fused to the A-MuLv promoter, optimized Kozak initiation sequence, human gamma-1 heavy chain 3' untranslated region, and the mouse DHFR gene for selection of transfected cells in a nucleoside-free medium. The cell line, CHO DG44, was maintained in Ham's F12 medium plus 10% FBS with glutamine/penicillin/streptomycin. The cells were transfected with linearized pING4222 DNA (40 μg digested with PvuI, phenol-chloroform extracted, ethanol precipitated) using the calcium phosphate method of Wigler, et al. Cell, 11:223 (1977). Following calcium phosphate treatment, the cells were plated in 96-well plates at approximately 10 4 cells/well and transfectants were obtained by growth in selective medium consisting of αMEM medium lacking nucleosides (Irvine Scientific) and supplemented with dialyzed FBS (100 ml serum dialyzed vs 4 L cold 0.15M NaCl using 6000-8000 MW cutoff, 16 hours, 4° C). Untransfected CHO-DG44 cells are unable to grow in this medium due to the DHFR mutation and the lack of nucleosides in the medium supplemented with dialyzed serum. At 2 weeks, each well contained approximately 2-3 colonies. The supernatants from wells of a 96-well plate were analyzed for the presence of rBPI(1-193) ala 132 by ELISA as in Section A. Twenty-four highest-producing clones were expanded into 24-well plates in selective αMEM medium supplemented with 0.05 μM methotrexate to induce gene amplification of the rBPI analog-encoding DNA. On observation of growth, cells were transferred to a new 24-well plate and productivity was assessed from S-sepharose eluates as described in section A for the pING4533/CHO-K1 transfectants. The five highest-producing clones were combined and subcloned by limiting dilution in 96-well plates. The supernatant wells containing single colonies were assayed for levels of rBPI(1-193)ala 132 by ELISA. Twenty highest-producing subclones were next expanded into 24-well plates and subjected to further amplification in the presence of 0.4 μM methotrexate and the levels of product expression for the amplified cells was determined by ELISA. The top producers, Clones 4, 75, and 80, secreted 25-37 μg/ml at 7 days in a 24- well plate containing S-sepharose. C. Transfection Of Sp2/O Cells With pING4223 And pING4221 A strategy adopted in an attempt to achieve optimal expression of desired rBPI products involved transfection of cells having a first expression plasmid with a first marker, screening for the highest producers, and then transfecting the same cells with a second expression plasmid having a different marker. This strategy is described below using Sp2/O cells. Plasmid pING4223 contains DNA encoding rBPI(1-193)ala 132 BPI fused to the A-MuLv promoter, optimized Kozak translation initiation sequence, human gamma-1 heavy chain 3' untranslated sequences, and the gpt marker for selection of MPA-resistant cells. The Sp2/O cell line was maintained in DMEM medium supplemented with 10% FBS with glutamine/penicillin/streptomycin. The Sp2/0 cells were transfected by electroporation with 40 μg of pING4223 DNA which had been digested with NotI, extracted with phenol-chloroform and ethanol precipitated. Following electroporation, the cells were allowed to recover for 48 hours in non-selective DMEM medium. The cells were then centrifuged and resuspended at a concentration of 5×10 4 cells/ml in DMEM medium supplemented with MPA (6 μg/ml) and xanthine (250 μg/ml) and plated at 10 4 cells/well in 96-well plates. Untransfected Sp2/O cells are unable to grow in this medium due to the inhibition of pyrimidine synthesis by the MPA. At 1.5-2 weeks, colonies consisting of transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of product-reactive protein by ELISA. The highest producers were transferred to a 24-well plate and productivity was assessed in extinct 24-well cultures for cells grown in the presence and absence of 10 -7 M dexamethasone, which causes an increase in expression by the A-MuLv promoter as a result of interactions with the glucocorticoid receptor. The best producer, Clone 2X3, secreted approximately 3 μg/ml and 7 μg/ml in the absence and presence of dexamethasone, respectively. Clone 2X3 was next transfected by electroporation with pING4221, which contains the his gene for selection of transfectants. Following recovery for 48 hours in DMEM plus 10% FBS medium, the cells were plated in 96-well plates at approximately 10 4 cells/well in DMEM/FBS supplemented with 6 μg/ml MPA, 250 μg/ml xanthine and 8 mM histidinol. Untransfected cells were unable to grow in the presence of the histidinol and MPA. At 1.5-2 weeks, transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of rBPI-reactive protein by ELISA. The highest producers were transferred to a 24-well plate. Productivity was assessed as extinct 24-well cultures for cells grown in the presence and absence of 10 7 M dexamethasone. The best producer, Clone 2X3-130, secreted approximately 15 μg/ml and 30 μg/ml in the absence and presence of dexamethasone, respectively. This isolate was next subcloned by limiting dilution in 96-well plates. Wells containing single colonies were screened by ELISA and the best producers were expanded and retested in 24 well cultures in the presence and absence of 10 -7 M dexamethasone. The highest producing subclone, No. 25, secreted approximately 16 μg/ml and 33 μg/ml in the absence and presence of dexamethasone, respectively. D. Transfection Of Sp2/0 Cells With pING4143 And pING4150 Plasmid pING4143 contains DNA encoding rBPI(1-193)ala 132 fused to the A-MuLv promoter, optimized Kozak translation initiation sequence, and mouse kappa light chain 3' untranslated sequences along with the gpt gene for selection of MPA-resistant cells. The Sp2/0 cells were transfected by electroporation with 40 μg of pING4143 DNA that was first digested with NotI, phenol-chloroform extracted, and ethanol precipitated. Following electroporation, the cells were allowed to recover for 48 hours in non-selective DMEM medium. The cells were then centrifuged and resuspended at a concentration of 5×10 4 cells/ml in DMEM medium supplemented with MPA (6 μg/ml) and xanthine (250 μg/ml) and plated at approximately 10 4 cells/well in 96-well plates. At approximately 2 weeks, colonies consisting of transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of BPI-reactive protein by ELISA. The highest producers were transferred to a 24-well plate. Productivity was assessed as extinct 24-well cultures for cells grown in the presence and absence of 10 -7 M dexamethasone. The best producer, Clone 134, secreted approximately 12 μg/ml and approximately 28 μg/ml in the absence and presence of dexamethasone, respectively. Clone 134 was transfected by electroporation with the vector, pING4150, which contains DNA encoding rBPI(1-193)ala 132 fused to the A-MuLv promoter and mouse light chain 3' untranslated region with the his gene for selection of transfectants. Prior to electroporation, the vector was first digested, and phenol-chloroform-extracted and ethanol precipitated. Following recovery for 48 hours in DMEM plus 10% FBS medium, the cells were plated in 96-well plates at approximately 10 4 cells/well in DMEM/FBS supplemented with 6 μg/ml MPA plus 250 μg/ml xanthine and 8 mM histidinol. Untransfected cells are unable to grow in the presence of MPA and histidinol. At approximately 2 weeks, colonies consisting of transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of BPI-reactive protein by ELISA. The highest producers were transferred to a 24-well plate. Productivity was assessed as extinct 24 well cultures for cells grown in the presence and absence of 10 -7 M dexamethasone. The highest producer, Clone 134-11, was re-designated C1770. Clone C1770 secreted 36 μg/ml without dexamethasone and greater than 42 μg/ml in the presence of dexamethasone. This clone (c1770) was deposited with the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852 as Accession No. HB 11247. E. Transfection Of CHO-K1 Cells With pING4143 The CHO-K1 cell line was transfected with pING4143 DNA in the manner described in Section A for transfection of CHO-K1 cells with pING4533. At approximately 2 weeks, supernatants from approximately 800 wells containing single colonies were analyzed for the presence of BPI-reactive protein by ELISA. The top producers were transferred to 24-well plates. The top producers, secreting approximately 9-13 μg/ml, may next be adapted to serum-free medium in preparation for growth in fermenters. These may also be re-transfected with a vector, such as pING4150 or pING4154 with his or neo as selective markers, respectively, to provide a cell line which produces even higher levels of rBPI product. F. Transfection Of CHO-K1 Cells With pING4144 Plasmid pING4144 is similar to pING4143 except that it contains the human cytomegalovirus (hCMV) promoter instead of the A-MuLv promoter. The CHO-K1 cell line was transfected with pING4144 DNA in the manner described above in Section A. At approximately 2 weeks, supernatants from approximately 200 wells containing single colonies were analyzed for the presence of BPI-reactive protein by ELISA. The top producers were transferred to 24-well plates and rBPI expression determined in 24-well plates containing sodium butyrate. The top producer (clone 174) secreted approximately 3-5 μg/ml without butyrate and approximately 15-18 μg/ml in the presence of 5 mM butyrate in this assay. This clone, re-designated clone C1771, was deposited with the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852 as ATCC accession No. CRL 11246. Top producers may next be adapted to serum-free medium in preparation for growth in fermenters. These may also be re-transfected with a vector, such as pING4151 or pING4155, containing the rBPI gene under control of the hCMV promoter, but with his or neo as selective markers, respectively, to provide a cell line which produces even higher levels of BPI. G. Transfection Of NSO Cells With pING4143 NS0 cells were transfected with pING4143 DNA by electroporation. At approximately 3 weeks, colonies consisting of transfected cells were observed in the 96-well plates. Supernatants from wells containing single colonies were analyzed for the presence of BPI-reactive protein by ELISA. The highest producers were transferred to a 24-well plate. Productivity was assessed as extinct 24-well cultures. The highest producers secreted a 15-16 μg/ml. The highest producers may be retransfected with a vector, such as pING4150, as described above to yield even higher producers. H. Transfection Of NS0 Cells With pING4232 NS0 cells were transfected by electroporation with pING4132, which contains DNA encoding rBPI(1-193)ala 132 fused to the optimal Kozak translation initiation sequence cloned into the vector pEE13 Bebbington, et al. Biotechnology, 10:169-175 (1992)!. Vector pEE13 contains the glutamine synthetase gene for selection of transfectants which are able to grow in medium lacking glutamine. At approximately three weeks, colonies consisting of transfected cells were observed in 96-well plates. Supernatants from wells containing single colonies were analyzed by ELISA. The highest producers were transferred to a 24-well plate. Productivity was assessed as extinct 24-well cultures. The highest producers, secreting 7-15 μg in extinct 24 well-cultures, may next be subjected to amplification in the presence of various concentrations of methionine sulfoximine. I. Transfection Of Sp2/0 Cells with pING4145 Plasmid pING4145 contains DNA encoding rBPI(1-193)ala 132 fused to the A-MuLv promoter, optimized Kozak translation initiation sequence, mouse kappa light chain 3' untranslated sequences, and a gpt gene for selection of MPA-resistant cells. The Sp2/0 cells were transfected by electroporation with 40 μg of pING4145 DNA that was first digested with NotI, phenol-chloroform extracted, and ethanol precipitated. Following electroporation, the cells were allowed to recover for 48 hours in non-selective DMEM medium, centrifuged, and resuspended at a concentration of 5×10 4 cells/ml in DMEM medium supplemented with MPA (6 μg/ml) and xanthine (250 μg/ml). The cells may then be plated at approximately 10 4 cells/well in 96-well plates. At approximately 2 weeks, colonies consisting of transfected cells are observed in the 96-well plates. Supernatants from wells containing single colonies may then be analyzed for the presence of BPI-reactive protein by ELISA. The highest producers are transferred to a 24-well plate and productivity is assessed as extinct 24-well cultures for cells grown in the presence and absence of 10 -7 M dexamethasone. In order to maximize the expression of BPI, the highest producing Sp2/0 transfectant may be transfected by electroporation with a vector which contains gene sequences encoding rBPI(1-193)ala 132 fused to the A-MuLv promoter and mouse light chain 3' untranslated region with the his gene for selection of transfectants. J. Transfection Of CHO-K1 Cells with pING4145 The CHO-K1 cell line was transfected with pING4145 DNA in the manner described above in Section A. At approximately 2 weeks, supernatants from approximately 500-800 wells containing single colonies may be analyzed for the presence of BPI-reactive protein by ELISA. The top producers are transferred to 24-well plates and BPI expression determined in 24-well plates containing S-sepharose. The top producers are next adapted to serum-free medium in preparation for growth in fermenters. These may also be re-transfected with a vector containing a different selective marker to provide a cell line which produces even higher levels of rBPI product. K. Expression of rBPI Products from Insect Cells Another eukaryotic system in which rBPI products may be expressed is insect cells which have been infected with a recombinant baculovirus containing DNA encoding an rBPI product. Systems for generating recombinant virus and for achieving expression of recombinant products therefrom are commercially available (Invitrogen, San Diego, Calif.). DNA encoding rBPI(1-199), including the 31 amino acid signal sequence, was cloned into an Nhel site in a pBlueBac transfer vector (Invitrogen). Sf9 insect cells (BRL; ATCC CRL 1711) were co-transfected with this vector and with wild type AcMNPV (Autographa californica multiple nuclear polyhidrosis virus, Invitrogen). Recombinant viral plaques were then identified, purified, and used to generate high-titer recombinant viral stocks as described in protocols available from BRL. The recombinant-produced baculovirus was used to infect further Sf9 cells. To do this, 8 separate 60 mm dishes of Sf9 cells were infected with the baculovirus. Each of the 8 dishes was sampled at different times during the day by collecting medium from a dish of infected cells. Upon collection, the medium was centrifuged at 1000 rpm for 10 minutes and the supernatant was stored at 4° C. Cells were then rinsed once with 4 ml PBS and lysed with 100 μl/dish NP40 lysis buffer (1% NP40, 150 mM NaCl, 50 mM Tris-HCl, pH 8.0) by incubating on ice for 30 minutes. Cells were then collected into an Eppendorf tube with a cell scraper. Cell lysates were then spun in a microfuge for 2 minutes. The lysate supernatant was transferred to a new tube and stored at -20° C. Media samples from each daily time point were analyzed for BPI content by ELISA and lysates were analyzed by Western using an anti-BPI antibody. No rBPI product was detectable in the media by ELISA on days 1-4 post-infection. However, on days 5-6 post-infection, a peak of 200-500 ng/ml rBPI product was detected in media samples. Western analysis of the lysates showed a BPI-reactive band of approximately 23 Kd at day 2 post-infection. That band showed increasing intensity through day 6. Table II, below, summarizes the transfections detailed in Sections A-J above. TABLE II______________________________________Host Cell Transfected With______________________________________CHO-DG44 pING4222CHO-K1 pING4533, pING4143, pING4144, pING4145NSO pING4143, pING4232SP2/O pING4223 followed by pING4221, pING4143 followed by pING4150, pING4145______________________________________ EXAMPLE 3 Construction Of Plasmids For in vitro Transcription And Translation Of rBPI (1-199)ala 132 And rBPI (1-199)Ser 135 In vitro transcription/translation studies were conducted using plasmid pIC127 as a source of DNA encoding rBPI (1-199). Construction of pIC127 was carried out as follows. DNA encoding rBPI (1-199), including the 31-amino acid signal sequence, was PCR amplified from a plasmid containing full-length cDNA encoding BPI in pGEM-72f(+). The amplification was done such that a SalI site was incorporated at the 5' end and XhoI and SstII sites were incorporated at the 3' end of the rBPI-encoding sequence by using the primers BPI-3: GTCGACGCATGCGAGAGAACATGGC (SEQ ID NO: 12) and BPI-2: CCGCGGCTCGAGCTATATTTTGGTCAT (SEQ ID NO: 9). The resulting PCR amplified fragment was blunt-end cloned into the Smal site of the multiple cloning region of plasmid pT7T3 18u (Pharmacia LKB Technology, Piscataway N.J.) in order to generate pIC102. The pIC102 insert encoding rBPI (1-199) and the 31-amino acid signal were then excised by digestion of the plasmid with BamHI and Asp718I. A BamHI site flanks the SalI site in pIC102 and an Asp718I site flanks the SstII site in pIC102. The ends of the excised fragment were made blunt with T4 DNA polymerase and the blunt fragment was then cloned into plasmid pGEM1 (ProMega, Madison, Wis.) which had first been digested with PstI and EcoRI and blunted with T4 DNA polymerase. The resulting construction was designated pIC124 and has the rBPI (1-199)-encoding insert oriented such that it 5' end is adjacent to the Sp6 promoter in pGEM1. The 31-amino acid signal sequence in the pIC124 insert was then excised by removing the region between two HincII sites in pIC124 to create pIC127. The excised region was replaced with a linker which restored the initiation codon (ATG) and the sequence encoding the first amino acid of BPI. Two fragments were isolated from pIC14 digestion with HincII and SstII: (1) the HincII-SstII fragment containing the rBPI (1-199) coding region excluding the codon for the first amino acid; and (2) the SstII-HincII fragment comprising the remainder of the plasmid. The first codon in the BPI coding sequence and a codon for methionine in front of the BPI sequence were inserted through use of linker formed from two complementary annealed oligonucleotides, BPI-28: GACGCCACCATGGTC (SEQ ID NO: 13) and BPI-29: GACCATGGTGGCGTC (SEQ ID NO: 14). Those two oligonucleotides were ligated together with the HincII-SstII and SstII-HincII fragments from plC124 to form plC127. Two plasmids, pML101 and pML102, were constructed using pIC127 for in vitro transcription/translation of rBPI(1-199)ala 132 and rBPI(1-199)ser 135 . To do this, pIC127 was digested with SstII and EcoRI and the large SstII-EcoRI fragment was purified. To construct pmL101, which contains an rBPI(1-199)ala 132 insert, the EcoRI-SstII fragment from pING4519 was ligated to the SstII-EcoRI fragment from PIC127. To construct pML102, which contains the rBPI (1-199) Ser 135 insert, the EcoRI-sstII fragment from pING4520 was ligated to the sstII-EcoRI fragment from pIC127. rBPI(1-199), rBPI(1-199)ser 135 , and BPI(1-199)ala 132 were expressed in vitro from plasmids pIC127, pML101, and pML102 using the TNT SP6 coupled Reticulocyte Lysate System from ProMega (Madison, Wis.). That system allows in vitro coupled transcription and translation of cloned genes using a eukaryotic translation system. Each coupled transcription/translation was carried out using the manufacturer's protocols with 2 μg of plasmid DNA in a total volume of 25 μl, including 35 S-methionine to generate labeled protein. The labeled protein products were added in 5 μl aliquots to a 20 μl urea sample buffer and heated at 95° C. for 3 minutes. Aliquots (10 μl) of each sample were run on a 15% SDS-Polyacrylamide gel either with or without DTT (50 mM). After fixing and drying the gel, the labeled protein bands were visualized by autoradiography. Results of the autoradiography demonstrate that cDNA encoding rBPI(1-199), rBPI(1-199)ala 132 , and rBPI(1-199)cys135 expressed protein products of the expected size of approximately 23 Kd for a BPI N-terminal fragment. Moreover, all three expression products, rBPI(1-199), rBPI(1-199)ala 132 , and rBPI(1-199)cys 135 , were capable of generating higher molecular weight species of the size expected for BPI(1-199) dimers, as well as larger species, all of which disappeared upon reduction with DTT. It is thought that the expression of dimeric species in the rBPI(1-199)cys 135 and rBPI(1-199)ala 132 products may be the result of using a cell-free in vitro transcription/translation system. Such a system does not allow proper post-translational processing, folding, etc. which would normally occur in cellular translation. Thus, it may be that proper disulfide linkages do not always form in the in vitro system, leading to formation of dimer in some cases. Labeled proteins generated in the above-described in vitro expression system were next tested for LPS binding activity. Wells of microtiter plates were coated with LPS from Salmonella Minnesota R7 (Rd mutant) (5 mg/ml in methanol stock culture) in 0.1M Na 2 CO 3 /20 mM EDTA (ethylenediamine tetraacetic acid) at pH 9.4 (a total of 2 μg LPS in a 50 μl well). Following overnight incubation at 4° C., the wells were rinsed with water and dried at 37° C. The wells were then blocked with 215 μl Dulbecco's-PBS/0.1% BSA for 3 hours at 37° C. The blocking solution was then discarded and the wells were washed with PBS/0.2% Tween-20. The rBPI samples were then added (2 μl of the translation reactant) to a 50 μl total volume in PBS/0.2% Tween. Following overnight incubation at 4° C., the wells were washed 3 times with PBS/0.2% Tween and the amount of labeled protein remaining in each well was determined by liquid scintillation counting. The results demonstrated that approximately equivalent LPS binding took place for all three BPI species referred to above. rBPI(1-199) displayed binding of 48,690 cpm; rBPI(1-199)ala 132 displayed binding of 59,911 cpm: and rBPI(1-199)cys 135 displayed binding of 52,537 cpm. each of the aforementioned values represents the average of triplicate determinations. The average binding of the control (no DNA) was 5,395 cpm. EXAMPLE 4 Product Characterization A. Physical Characterization Characterization of rBPI products was accomplished using reverse phase (C4) HPLC, cation exchange (MA7C) HPLC, SDS-PAGE, and electrospray ionization mass spectrometry (ESI-MS). The rBPI products to be characterized were purified from roller bottles or from a 10 Liter fermenter harvest by either a single-step purification procedure or by a multi-step procedure. The single-step procedure was essentially that disclosed in co-pending, co-owned U.S. patent application Ser. No. 07/885,501 by Grinna, incorporated herein by reference, with the addition of a second wash step. In brief, S-sepharose beads were added to a growth medium containing rBPI products. The S-sepharose was then removed from the medium and washed with 20 mM sodium acetate and 100 mM sodium chloride at pH4.0. A second wash was performed with 20 mM sodium acetate and 700 mM sodium chloride at pH4.0. The purified rBPI products were eluted with 20 mM sodium acetate and 1000 mM sodium chloride at pH4.0. The multi-step purification procedure involved the purification of pooled batches of rBPI products which had first been purified separately as described above. After purification of each of twenty individual rBPI product batches by the single-step method, the batches were pooled and repurified by first diluting the salt concentration of the pooled batches to 200 mM. The pooled sample was then loaded onto an S-sepharose column and was washed at pH4.0 with 20 mM sodium acetate, and 200 mM sodium chloride followed by 700 mM sodium chloride. The rBPI products were eluted using 20 mM sodium acetate and 1000 mM sodium chloride at pH4.0. The purified rBPI products were then analyzed to determine their physical characteristics. 1. SDS-PAGE Analysis of rBPI Products SDS-PAGE analysis of rBPI products was carried out using 14% polyacrylamide gels and a tris-glycine buffer system under reducing and non-reducing conditions. Protein bands were stained with either Coomassie Blue or silver stain for visualization. As shown in FIG. 1, non-reduced rBPI(1-199) appeared as a major band at approximately 23 kD and a minor band at approximately 40 kD. The major band was identified as rBPI(1-199) by comparison with simultaneously-run standards and the minor band was identified as a dimeric form of rBPI(1-199) by immunostaining. Upon addition of a 1/20 volume of 0.4M dithiothreitol (DDT) to a separate sample of rBPI(1-199), SDS-PAGE revealed a single, well-defined band corresponding to the 23 kD monomeric species of rBPI(1-199) identified under non-reducing conditions as described above. SDS-PAGE analysis of the rBPI(1-199)ala 132 product revealed a single band which migrated with the single 23 kD rBPI(1-199) band under reducing conditions. Under non-reduced conditions, rBPI(1-199)ala 132 migrated with the faster-migrating of the two closely-spaced bands seen for rBPI(1-199) (corresponding to the 23 kD band). These results, shown in FIGS. 2A and 2B, indicate that rBPI(1-199)ala 132 exists in essentially monomeric form after purification. Thus, rBPI products in which a cysteine residue is replaced by alanine display significant resistance to dimer formation. 2. Cation Exchange HPLC Analysis of rBPI Products Cation exchange HPLC using an MA7C column was also employed to measure the dimer content of rBPI products. A Bio-Rad MA7C cartridge (4.6×30 mm, Bio-Rad Catalog No. 125-00556) equilibrated with 40%c buffer B (20 mM MES, 1M NaCl, pH 5.5) at 1.0 ml/min was used. The rBPI(1-199) product was analyzed by diluting a 1 ml sample to 100 μg/ml and 200 μl of the diluted sample was injected onto the column. The rBPI was eluted with a gradient of 40% to 100% buffer B over 6 minutes. Buffer A comprised 20 mM MES at pH5.5. Absorbance was monitored at 229 nm. Analysis of rBPI(1-199) revealed two peaks. A first peak eluted with a retention time of approximately 3 minutes as shown in FIG. 3. A second, smaller peak eluted at approximately 6 minutes. The first peak, shown in FIG. 3, represents rBPI(1-199) monomer and the second peak in FIG. 3 represents rBPI(1-199) dimer as determined by comparisons with the retention times of purified monomer and dimer standards. The second (dimer) peak did not appear when samples were reduced with DTT prior to being injected on the column. Identical procedures were used to determine the elution pattern of rBPI(1-199)ala 132 . As shown in FIG. 4, rBPI(1-199)ala 132 elutes as a single peak with a retention time corresponding to that observed for the rBPI(1-199) monomer peak. There was no evidence of dimer in the rBPI(1-199)ala 132 sample. 3. Reverse Phase (C4) HPLC and Electrospray-ionization Mass Spectrometry Analysis of rBPI Products Microheterogeneity of rBPI products was revealed by reverse phase HPLC and electrospray-ionization mass spectrometry (ESI-MS). For the HPLC analysis, a Brownlee BU-300 C4 column was equilibrated with 37% Mobile Phase B (80% acetonitrile/0.065% TFA) at a flow rate of 0.5 ml/min. Samples (1 ml each) of rBPI(1-199) were diluted to 100 μg/ml and 50 μl of the sample was injected. The column was washed with 37% Mobile Phase B for 2.5 minutes and then eluted using a gradient from 37% to 50% Mobile Phase B over 20 minutes. Mobile Phase A was 5% acetonitrile/0.1% TFA and absorbance was monitored at 220 nm. The results of reverse phase HPLC analysis of rBPI(1-199) products are shown in FIG. 5. rBPI(1-199) products elute as a second (major) peak with a partially-resolved first (minor) peak on the leading edge of the second peak. Upon reduction with DTT only one peak, corresponding to the second peak elutes from the column. Identical procedures were used to analyze rBPI(1-199)ala 132 products. As shown in FIG. 6, rBPI(1-199)ala 132 eluted as a single peak corresponding to the second (major) peak referred to above. The eluates corresponding to the first and second HPLC peaks described above from three separate batches of rBPI(1-199) were isolated and analyzed to determine their content by ESI-MS. Analysis of the eluate which produced the second (major) peak from the rBPI(1-199) run revealed a slightly lower mass than would be expected for a 199-amino acid protein. These data indicate that the most abundant mass found in the second peak eluate corresponded to a 1-193 rBPI protein fragment. However, other species, ranging in size from 1-198 to 1-194, are also present. Analysis of the eluate producing the single peak obtained from HPLC on rBPI(1-199)ala 132 revealed results similar to those obtained from the eluate which produced the second (major) peak above. These results are consistent with peptide mapping data which reveal truncated carboxy termini in rBPI(1-199) products. When the same analysis was performed on rBPI(1-193) products, significantly reduced C-terminal heterogeneity was observed. The ESI-MS data obtained from rBPI(1-193) products revealed that approximately 85% of the protein contains either the first 191, 193, or 193 (+ an N-terminal alanine) amino acids of the BPI N-terminal. The results are shown in Table III. TABLE III______________________________________Electrospray-Ionization Mass Spectrometry Resultsfor rBPI(1-193) and rBPI(1-199) HPLC Monomer PeaksExpected Approximate Predicted Amino ApproximaterBPI Product Molecular Mass Acid Residues Relative Intensity*______________________________________rBPI(1-199) 21407 1-193 50.9% 21606 1-195 28.9% 21505 1-194 20.1% 21738 1-196 <10% 21846 1-197 <10% 21966 1-198 <10%rBPI(1-193) 21408 1-193 36.2% 21193 1-191 34.1% 21293 1-192 <10% 21477 1-193 + N- 14.5% terminal alanine 20924 1-189 15.2%______________________________________ *Only species detected as being present in amounts greater than 10% were quantitated. These species were then normalized to 100%. These data demonstrates that, while the rBPI(1-199)-encoding DNA produced no full-length (i.e. amino acids 1-199 of the BPI N-terminal) protein, the rBPI (1-193)-encoding DNA produced significant amounts of the rBPI(1-193) protein. Based upon these or other data, it appears that significant reductions in heterogeneity and significant increases in production of the intended protein (i.e. that for which the DNA insert codes may be obtained), while maintaining optimal bactericidal and LPS-binding activity, by using truncated forms of the rBPI-encoding DNA. It is expected that truncation of the DNA to be expressed will produce significant reductions in heterogeneity of the expression product to the extent that the DNA to be expressed is not truncated beyond the cysteine at amino acid residue 175. Expression products of truncated forms of DNA encoding rBPI proteins which have in the range of the first 176 amino acids of the BPI N-terminal to the First 193 amino acids of the BPI N-terminal are also expected to retain full bactericidal and LPS-binding activity. The ESI-MS data also revealed the presence of microheterogeneity at the amino terminal of rBPI products. Forms of the rBPI product having an alanine residue at the amino terminus were found and confirmed by sequencing of tryptic peptides. As shown in FIG. 5, the ESI-MS study of the eluate which produced the first (minor) reverse phase HPLC peak revealed proteins having a mass distribution similar to those which formed the second (major) peak except that each mass value was higher by approximately 119-120 Daltons. These data suggest that the eluate producing the First (minor) HPLC peak described above contains a disulfide-linked cysteine adduct, as this would account for the uniform shift of the mass values. To test the hypothesis that the first (minor) reverse phase HPLC peak produced by rBPI(1-199) represents cysteine adducts, rBPI(1-199) was exposed to ElIman's reagent (dithionitrobenzenoic acid, DTNB) which binds to free sulfhydryl groups in roughly molar equivalents. Such treatment demonstrated that there is less than one mole of free sulfhydryl per mole of rBPI(1-199). Given the presence of three cysteine residues in BPI (at positions 132, 135 and 175), these results support the notion that there is either an intramolecular disulfide link in the rBPI products or that two of the sulfhydryl groups are sterically unavailable. rBPI(1-199)ala 132 showed no reactivity with Ellman's reagent. 4. Storage Stability of rBPI(1-199) Products Samples of rBPI(1-199) (1 mg/ml) in a buffer comprising 20 mM sodium citrate, 0.15M Sodium Chloride buffer, 0.1% poloxamer, and 0.002% polysorbate 80 at pH5.0 were analyzed to determine their storage stability over an 8-week period at the recommended storage temperature of 2°-8° C. and at higher temperatures of 22° C. and 37° C. The results for storage at 2°-8° C. presented in Table IV, show an increase in the presence of dimer (from 1% to 4%), but no significant increase in cysteine adduct or particle formation in the sample. TABLE IV__________________________________________________________________________Storage Appearance/ % Unknown % Dimer Protein % Cysteine LAL Inhibition Particles/mL Particles/mLTime Color pH Impurities by HPLC mg/mL Adduct IC.sup.50, nG/mL ≧10 μm ≧25__________________________________________________________________________ μminitial clear/colorless 5.1 ND 1.0 1.04 12 10 230 54 weeks clear/colorless 5.0 ND 3.2 1.02 11 11 113 28 weeks clear/colorless 5.0 ND 4.4 1.02 14 9 125 5__________________________________________________________________________ However, storage at the increased temperatures of 22° C. and 37° C. show that the presence of dimer and particles in the sample increased dramatically and the amount of cysteine adduct increased moderately. These results are shown in Table V. Additionally, when rBPI(1-193)ala 132 is stored at 22° C. to 37° C., no dimer was detected after storage for two weeks. Under similar conditions, rBPI(1-199) displays significant increases. TABLE V__________________________________________________________________________ Storage % Unknown % Dimer Protein % Cysteine LAL Inhibition Particles/mL Particles/mLTemperature Time Appearance/Color pH Impurities by HPLC mg/mL Adduct IC.sup.50, nG/mL ≧10 ≧25__________________________________________________________________________ μm initial clear/colorless 5.1 ND 1.0 1.04 12 10 230 522 C. 4 weeks clear/colorless 5.0 ND 4.5 1.02 12 10 100 4 8 weeks clear/colorless 5.0 ND 6.8 1.02 14 6 126 337° C. 4 weeks a few particles 5.0 ND 7.9 0.96 16 12 1,709 20 8 weeks numerous particles 5.0 ND 13.1 0.88 18 7 20,287 611__________________________________________________________________________ 5. Turbidity of rBPI Product Pharmaceutical Compositions Experiments were done to determine the turbidity of various rBPI-containing pharmaceutical compositions. In this context, turbidity refers to the tendency of pharmaceutical compositions to engage in unfolding (i.e. loss of tertiary protein structure) and/or particle formation (interactions between individual proteins to form large (>10 μm) particles). The pharmaceutical compositions tested contained either rBPI(1-199), rBPI(1-199)ala 132 , or rBPI(1-193)ala 132 in either a citrate buffer (20 mM sodium citrate/150 mM sodium chloride. pH 5.0) or a citrate buffer containing 0.1% poloxamer 188 (a poloxamer surfactant comprised of polyoxypropylene-polyoxyethylene block copolymer) and 0.002% polysorbate 80 (a polysorbate surfactant comprising polyoxyethylene sorbitan fatty acid ester). As mentioned above, use of a combination poloxamer/polysorbate surfactant system stabilizes pharmaceutical compositions as taught in co-owned, incorporated herein by reference. Samples were analyzed to determine their resistance to turbidity over time at increasing temperature and at either pH 7.0 or pH 5.0. Prior to analysis, all samples were diluted to a concentration of 0.1 mg/ml in either 50 mM potassium phosphate or 20 mM citrate buffer at pH 7.0. Turbidity measurements were obtained by placing samples in quartz cuvettes for use in a Shimadzu UV-160 UV-Vis spectrophotometer (Shimadzu, Pleasanton, Calif.) equipped with a temperature-controlled cuvette holder attached to a recirculating water bath. Upon equilibrating the cuvette holder at the desired temperature (57° C., 65° C. or 85° C., see below), absorbance at 280 nm was measured to confirm that samples had been diluted to the proper concentration. Following this, the absorbance of samples at 350 nm was measured every 2 minutes for 1 hour to determine the change in absorbance over time. Results are presented in FIG. 7; wherein "formulated" refers to the rBPI product in citrate buffer containing the poloxamer/polysorbate combination referred to above, and "unformulated" refers to rBPI compounds in citrate buffer alone. A lower rate of change in turbidity (i.e., a lower rate of increase in absorbance over time) indicates increased stability against unfolding and the formation of particles. As shown in FIG. 7, the addition of the aforementioned combination of surfactants resulted in increased stability (resistance to particle formation and unfolding) of all compositions tested. Moreover, the rBPI(1-199)ala 132 and rBPI(1-193)ala 132 exhibited greatly improved resistance to unfolding and particle formation relative to wild-type compositions--regardless of whether the surfactant combination was present. Similar results were obtained at pH 5.0 and 65° C. at pH 5.0 and 75° C. and at 85° C., respectively. Overall, compositions with the surfactant combination and/or the cysteine deletion showed greatly increased stability over time and through increases in temperature as compared to compositions with no surfactant and/or having the wild type BPI(1-199) N-terminal construction. B. In Vitro Activity Characterizations In Vitro activity of rBPI(1-199)ala 132 products was determined by binding of the products to LPS, by the LAL inhibition assay, and by the bactericidal potency of the products. 1. Binding Of rBPI(1-199)ala 132 To LPS Samples (20 μg to 60 μg each) of E. coli (Strain 0111-B4) or S. minnesota (Rd mutant) lipopolysaccharide (Sigma Chemical. St. Louis. Mo.) were used to determine the ability rBPI(1-199)ala 132 products to bind LPS. The LPS samples were size fractionated by SDS-PAGE and silver stained for visualization or electrotransferred to a nitrocellulose membrane (BA25, Schleicher and Schuell, Keene, N. Mex.) with appropriate pre-stain standards. The LPS blots were processed by soaking the membrane in 50 mM Tris, 0.2M NaCl (TBS), and 30 mg/ml bovine serum albumin (BSA) at pH 7.4 for 30 minutes at 37° C. Membranes were then incubated in a solution containing 2-4 μg of purified or partially purified rBPI(1-199)ala 132 or a control protein (either rBPI(1-199) or rBPI holoprotein) for 12-18 hours at 21° C. to 42° C. After incubation, the membranes were then washed with TBS-BSA. The solution was changed at least three times over a 30 minute period. The washed membranes were then incubated for 3 hours in a 1:1000 dilution of rabbit anti-rBPI(1-199) in TBS containing 1 mg/ml BSA. Membranes were next washed at least three times and were developed using the Chemiluminescent Detection System (Tropix Systems, Bedford, Mass.) according to the manufacturers instructions, using 5×PBS and 0.25% gelatin (Bio-Rad) in place of I-block. The results demonstrate that rBPI(1-199)ala 132 binds to LPS fixed to nitrocellulose as well or better than rBPI(1-199). 2. E. coli Growth Inhibition Assay The E. coli broth growth inhibition assay was conducted to determine the bactericidal potency of rBPI products by treating E. coli with rBPI(1-199) or rBPI(1-199)ala 132 analogs and monitoring the inhibition of broth growth as a measure of bactericidal activity. A "rough" strain of E. coli with short-chain LPS, designated J5 (a rough UDP-4-epimerase-less mutant of E. coli strain 0111:B4), was used in the assay. Cells were grown in a triethanolamine-buffered mineral salts medium (Simon, et al. Proc. Nat. Acad Sci, 51:877 (1964)) which rendered E. coli especially sensitive to BPI. The cells were washed and resuspended in 0.9% NaCl to a density of about 5×10 8 cells/ml. Approximately 5×10 6 to 1×10 7 E. coli cells were incubated for 30-60 minutes with either rBPI(1-199) or with rBPI(1-199)ala 132 analogs at a concentration of 5 μg/ml with a buffered solution (10% Hanks Balanced Salts, 40 mM Tris-Hcl, pH 7.5. 0.1% casamino acids) in a volume of 200-400 ml. In addition, the assay was run separately with either rBPI(1-199) or rBPI(1-199)ala 132 analog and 100 mM MgCl 2 . Following incubation, the cells were diluted with 10 volumes of nutrient broth supplemented with 0.9%c Nacl. Broth growth was then monitored for several hours. The results demonstrate that rBPI(1-199)ala 132 analogs possess bactericidal activity as potent or more potent than rBPI(1-199). The bactericidal activity of both rBPI(1-199)ala 132 analogs and that of rBPI(1-199) were reduced, as expected, by MgCl 2 . 3. LAL Inhibition Assay The LAL inhibition assay was used to determine the ability of rBPI(1-193)ala 132 to bind LPS. An LAL inhibition assay is described in Gazzano-Santoro, Infect. Immun., 60:4754-4761 (1992). Results of the LAL assay demonstrate that rBPI(1-193)ala 132 has an IC-50 value of 10, which is equal to that for rBPI(1-199). These data indicate that the analog competes as well as the wild-type rBPI product for binding to LPS. C. Efficacy Of rBPI(1-199)ala 132 In An Animal Model Of Lethal Endotoxemia An animal model of endotoxemia was used to evaluate the comparative effectiveness of rBPI(1-199)ala 132 and rBPI(1-199) against endotoxic shock. Male ICR mice received intravenous injections of 800 μg/kg actinomycin-D and either 0.5 μg/kg or 1.0 μg/kg of an endotoxin (E. coli, Strain 0111:B4). Immediately following the injection of endotoxin, the mice received an intravenous injection (0.5 mg/kg or 5.0 mg/kg) of either rBPI(1-199) or rBPI(1-199)ala 132 . Buffered vehicle was used as a control. Deaths were then recorded over a 7-day period. The results are presented below in Table VI. TABLE VI______________________________________ BPI Dose # Dead/Total % Mortality______________________________________Buffer only 0 14/15 93rBPI.sub.23 0.5 mg/kg 7/15 47 5.0 mg/kg 8/15 53rBPI.sub.23 -cys 0.5 mg/kg 14/15 93 5.0 mg/kg 8/16 50______________________________________ As seen in Table VI, both rBPI(1-199)ala 132 and rBPI(1-199) provided significant protection against the lethal effects of the endotoxin. Although the present invention has been presented in terms of its preferred embodiments, the skilled artisan realizes that numerous modifications and substitutions are within the scope of the present teaching. For example, substitution of the cysteine at position 132 or 135 of the BPI N-terminal fragment with non-polar amino acids other than alanine or serine is contemplated by the invention. Thus, the scope of the appended claims and any future amendments thereto. __________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 14(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 1813 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(ix) FEATURE:(A) NAME/KEY: CDS(B) LOCATION: 31..1491(ix) FEATURE:(A) NAME/KEY: mat.sub.-- .sub.-- eptide(B) LOCATION: 124..1491(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:CAGGCCTTGAGGTTTTGGCAGCTCTGGAGGATGAGAGAGAACATGGCCAGGGGC54MetArgGluAsnMetAlaArgGly31-30-25CCTTGCAACGCGCCGAGATGGGTGTCCCTGATGGTGCTCGTCGCCATA102ProCysAsnAlaProArgTrpValSerLeuMetValLeuValAlaIle20-15- 10GGCACCGCCGTGACAGCGGCCGTCAACCCTGGCGTCGTGGTCAGGATC150GlyThrAlaValThrAlaAlaValAsnProGlyValValValArgIle515TCCCAGAAGGGCCTGGACTACGCCAGCCAGCAGGGGACGGCCGCTCTG198SerGlnLysGlyLeuAspTyrAlaSerGlnGlnGlyThrAlaAlaLeu10152025CAGAAGGAGCTGAAGAGGATCAAGATTCCTGACTACTCAGACAGCTTT246GlnLysGluLeuLysArgIleLysIleProAspTyrSerAspSerPhe303540AAGATCAAGCATCTTGGGAAGGGGCATTATAGCTTCTACAGCATGGAC294LysIleLysHisLeuGlyLysGlyHisTyrSerPheTyrSerMetAsp455055ATCCGTGAATTCCAGCTTCCCAGTTCCCAGATAAGCATGGTGCCCAAT342IleArgGluPheGlnLeuProSerSerGlnIleSerMetValProAsn606570GTGGGCCTTAAGTTCTCCATCAGCAACGCCAATATCAAGATCAGCGGG390ValGlyLeuLysPheSerIleSerAsnAlaAsnIleLysIleSerGly758085AAATGGAAGGCACAAAAGAGATTCTTAAAAATGAGCGGCAATTTTGAC438LysTrpLysAlaGlnLysArgPheLeuLysMetSerGlyAsnPheAsp9095100105CTGAGCATAGAAGGCATGTCCATTTCGGCTGATCTGAAGCTGGGCAGT486LeuSerIleGluGlyMetSerIleSerAlaAspLeuLysLeuGlySer110115120AACCCCACGTCAGGCAAGCCCACCATCACCTGCTCCAGCTGCAGCAGC534AsnProThrSerGlyLysProThrIleThrCysSerSerCysSerSer125130135CACATCAACAGTGTCCACGTGCACATCTCAAAGAGCAAAGTCGGGTGG582HisIleAsnSerValHisValHisIleSerLysSerLysValGlyTrp140145150CTGATCCAACTCTTCCACAAAAAAATTGAGTCTGCGCTTCGAAACAAG630LeuIleGlnLeuPheHisLysLysIleGluSerAlaLeuArgAsnLys155160165ATGAACAGCCAGGTCTGCGAGAAAGTGACCAATTCTGTATCCTCCAAG678MetAsnSerGlnValCysGluLysValThrAsnSerValSerSerLys170175180185CTGCAACCTTATTTCCAGACTCTGCCAGTAATGACCAAAATAGATTCT726LeuGlnProTyrPheGlnThrLeuProValMetThrLysIleAspSer190195200GTGGCTGGAATCAACTATGGTCTGGTGGCACCTCCAGCAACCACGGCT774ValAlaGlyIleAsnTyrGlyLeuValAlaProProAlaThrThrAla205210215GAGACCCTGGATGTACAGATGAAGGGGGAGTTTTACAGTGAGAACCAC822GluThrLeuAspValGlnMetLysGlyGluPheTyrSerGluAsnHis220225230CACAATCCACCTCCCTTTGCTCCACCAGTGATGGAGTTTCCCGCTGCC870HisAsnProProProPheAlaProProValMetGluPheProAlaAla235240245CATGACCGCATGGTATACCTGGGCCTCTCAGACTACTTCTTCAACACA918HisAspArgMetValTyrLeuGlyLeuSerAspTyrPhePheAsnThr250255260265GCCGGGCTTGTATACCAAGAGGCTGGGGTCTTGAAGATGACCCTTAGA966AlaGlyLeuValTyrGlnGluAlaGlyValLeuLysMetThrLeuArg270275280GATGACATGATTCCAAAGGAGTCCAAATTTCGACTGACAACCAAGTTC1014AspAspMetIleProLysGluSerLysPheArgLeuThrThrLysPhe285290295TTTGGAACCTTCCTACCTGAGGTGGCCAAGAAGTTTCCCAACATGAAG1062PheGlyThrPheLeuProGluValAlaLysLysPheProAsnMetLys300305310ATACAGATCCATGTCTCAGCCTCCACCCCGCCACACCTGTCTGTGCAG1110IleGlnIleHisValSerAlaSerThrProProHisLeuSerValGln315320325CCCACCGGCCTTACCTTCTACCCTGCCGTGGATGTCCAGGCCTTTGCC1158ProThrGlyLeuThrPheTyrProAlaValAspValGlnAlaPheAla330335340345GTCCTCCCCAACTCCTCCCTGGCTTCCCTCTTCCTGATTGGCATGCAC1206ValLeuProAsnSerSerLeuAlaSerLeuPheLeuIleGlyMetHis350355360ACAACTGGTTCCATGGAGGTCAGCGCCGAGTCCAACAGGCTTGTTGGA1254ThrThrGlySerMetGluValSerAlaGluSerAsnArgLeuValGly365370375GAGCTCAAGCTGGATAGGCTGCTCCTGGAACTGAAGCACTCAAATATT1302GluLeuLysLeuAspArgLeuLeuLeuGluLeuLysHisSerAsnIle380385390GGCCCCTTCCCGGTTGAATTGCTGCAGGATATCATGAACTACATTGTA1350GlyProPheProValGluLeuLeuGlnAspIleMetAsnTyrIleVal395400405CCCATTCTTGTGCTGCCCAGGGTTAACGAGAAACTACAGAAAGGCTTC1398ProIleLeuValLeuProArgValAsnGluLysLeuGlnLysGlyPhe410415420425CCTCTCCCGACGCCGGCCAGAGTCCAGCTCTACAACGTAGTGCTTCAG1446ProLeuProThrProAlaArgValGlnLeuTyrAsnValValLeuGln430435440CCTCACCAGAACTTCCTGCTGTTCGGTGCAGACGTTGTCTATAAA1491ProHisGlnAsnPheLeuLeuPheGlyAlaAspValValTyrLys445450455TGAAGGCACCAGGGGTGCCGGGGGCTGTCAGCCGCACCTGTTCCTGATGGGCTGTGGGGC1551ACCGGCTGCCTTTCCCCAGGGAATCCTCTCCAGATCTTAACCAAGAGCCCCTTGCAAACT1611TCTTCGACTCAGATTCAGAAATGATCTAAACACGAGGAAACATTATTCATTGGAAAAGTG1671CATGGTGTGTATTTTAGGGATTATGAGCTTCTTTCAAGGGCTAAGGCTGCAGAGATATTT1731CCTCCAGGAATCGTGTTTCAATTGTAACCAAGAAATTTCCATTTGTGCTTCATGAAAAAA1791AACTTCTGGTTTTTTTCATGTG1813(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 487 amino acids(B) TYPE: amino acid(D) TOPOLOGY: linear(ii) MOLECULE TYPE: protein(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:MetArgGluAsnMetAlaArgGlyProCysAsnAlaProArgTrpVal31-30-25-20SerLeuMetValLeuValAlaIleGlyThrAlaValThrAlaAlaVal15-10-51AsnProGlyValValValArgIleSerGlnLysGlyLeuAspTyrAla51015SerGlnGlnGlyThrAlaAlaLeuGlnLysGluLeuLysArgIleLys202530IleProAspTyrSerAspSerPheLysIleLysHisLeuGlyLysGly354045HisTyrSerPheTyrSerMetAspIleArgGluPheGlnLeuProSer50556065SerGlnIleSerMetValProAsnValGlyLeuLysPheSerIleSer707580AsnAlaAsnIleLysIleSerGlyLysTrpLysAlaGlnLysArgPhe859095LeuLysMetSerGlyAsnPheAspLeuSerIleGluGlyMetSerIle100105110SerAlaAspLeuLysLeuGlySerAsnProThrSerGlyLysProThr115120125IleThrCysSerSerCysSerSerHisIleAsnSerValHisValHis130135140145IleSerLysSerLysValGlyTrpLeuIleGlnLeuPheHisLysLys150155160IleGluSerAlaLeuArgAsnLysMetAsnSerGlnValCysGluLys165170175ValThrAsnSerValSerSerLysLeuGlnProTyrPheGlnThrLeu180185190ProValMetThrLysIleAspSerValAlaGlyIleAsnTyrGlyLeu195200205ValAlaProProAlaThrThrAlaGluThrLeuAspValGlnMetLys210215220225GlyGluPheTyrSerGluAsnHisHisAsnProProProPheAlaPro230235240ProValMetGluPheProAlaAlaHisAspArgMetValTyrLeuGly245250255LeuSerAspTyrPhePheAsnThrAlaGlyLeuValTyrGlnGluAla260265270GlyValLeuLysMetThrLeuArgAspAspMetIleProLysGluSer275280285LysPheArgLeuThrThrLysPhePheGlyThrPheLeuProGluVal290295300305AlaLysLysPheProAsnMetLysIleGlnIleHisValSerAlaSer310315320ThrProProHisLeuSerValGlnProThrGlyLeuThrPheTyrPro325330335AlaValAspValGlnAlaPheAlaValLeuProAsnSerSerLeuAla340345350SerLeuPheLeuIleGlyMetHisThrThrGlySerMetGluValSer355360365AlaGluSerAsnArgLeuValGlyGluLeuLysLeuAspArgLeuLeu370375380385LeuGluLeuLysHisSerAsnIleGlyProPheProValGluLeuLeu390395400GlnAspIleMetAsnTyrIleValProIleLeuValLeuProArgVal405410415AsnGluLysLeuGlnLysGlyPheProLeuProThrProAlaArgVal420425430GlnLeuTyrAsnValValLeuGlnProHisGlnAsnPheLeuLeuPhe435440445GlyAlaAspValValTyrLys450455(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 25 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:AAGCTTGTCGACCAGGCCTTGAGGT25(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:CTGGAGGCGGTGATGGTG18(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 19 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:CTCCAGCAGCCACATCAAC19(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 18 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:GAACTTGGTTGTCAGTCG18(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 13 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:GCCACCRCCATGG13(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 27 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:ACTGTCGACGCCACCATGGCCAGGGGC27(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 27 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:CCGCGGCTCGAGCTATATTTTGGTCAT27(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 16 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:CTGTAGCTCGAGCCGC16(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:GGCTCGAGCTACAGAGT17(2) INFORMATION FOR SEQ ID NO:12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 25 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:GTCGACGCATGCGAGAGAACATGGC25(2) INFORMATION FOR SEQ ID NO:13:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:GACGCCACCATGGTC15(2) INFORMATION FOR SEQ ID NO:14:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA(xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:GACCATGGTGGCGTC15__________________________________________________________________________

Disclosed are novel bactericidal/permeability-increasing (BPI) protein products wherein cysteine residue number 132 or 135 is replaced by another amino acid residue, preferably an alanine or serine residue and/or wherein the leucine residue at position 193 is the carboxy terminal residue. Also disclosed are DNA sequences encoding methods for the production of the same in appropriate host cells, and stable homogeneous pharmaceutical compositions containing the analogs suitable for use treatment of gram negative bacterial infection and its sequelae.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation in part of U.S. patent application Ser. No. 09/504,133, filed Feb. 15, 2000. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vessel for measuring, storing, dispensing and recording the consumption of liquid and more particularly the inclusion of tactile buttons in the side wall of a water storage vessel for indicating a tally of the initial and repeated filling of water in the vessel. 2. Description of Related Art Next to air, water is the element most necessary for human survival. In the past, it had been widely accepted and usually recommended for an adult individual to consume eight cups (64 oz) of water per day. However, this one size fits all standard is rapidly being replaced with a common sense approach to daily water intake. A suggested formula for a daily water intake after evaluating of users physical condition is ½ ounce per pound of body weight when an individual is inactive and ⅔ ounce per pound when an individual is engages in athletic activity. It has been suggested that before exercise an amount of water be ingested. The water intake should be at regular intervals throughout waking hours. A need therefore exists for a device to enable an individual to tally the consumption of water in measurable amounts throughout a given period, e.g., 24 hr. period. It is an object of the present invention to provide a vessel enabling storing the measurement of liquids along with a resettable indicator to tally the number of refills of the vessel and therefore consumption of liquid over a designated period. SUMMARY OF THE INVENTION According to the present invention there is provided a device for use in dispensing, measuring and recording consumption of a liquid, the device comprising in combination of a vessel having a boundary wall enclosing a volume for storing a liquid, the boundary wall terminates to form an aperture to supply and discharge liquid to the vessel, and a plurality of tactile buttons supported by the vessel and having bidirectional positions to indicate a tally of repeated filling of liquid in the vessel. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS These features and advantages as well as others will be more fully understood when the following description is read in light of the accompanied drawings of which: FIG. 1 is a perspective of elevation of one embodiment of the device according to the present invention; FIG. 2 is a sectional view taken along lines II—II of FIG. 1; FIGS. 3 and 4 are enlarged fragmentary views of a tactile button used to tally repeated fillings of liquid in the device; FIG. 4A is an enlarged sectional view of the side wall construction of a tactile button shown in FIGS. 3 and 4; FIGS. 4B, 4 C and 4 D are sectional views similar to FIG. 4 A and illustrating three additional embodiments of a tactile button shown in FIGS. 3 and 4; FIG. 5 is a plan view of the tactile button shown in FIG. 4; FIG. 6 is a view similar to FIG. 1 illustrating a second embodiment of the present invention; FIG. 7 is a top plan view of the embodiment as shown in FIG. 6; FIG. 8 is a sectional view similar to FIG. 4 A and illustrating an enlarged fragmentary view of a tactile button used to tally repeated fillings of liquid in the device according to a still further embodiment of the present invention; and FIG. 9 is a sectional view similar to FIG. 4 A and illustrating an enlarged fragmentary view of a tactile button used to tally repeated fillings of liquid in the device according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION In the embodiment of the invention shown in FIGS. 1-5, the device for measuring, storing, dispensing and recording consumption of a liquid takes the form of an elongated vessel 100 having undulated vertically, annular side wall 102 integral with a bottom wall 104 . The side wall at the end opposite the bottom wall has an annular opening surrounded by thread bars for releasably receiving sports cap 106 . As is well known, the sports cap includes a dispenser nozzle 108 that can be raised from a lower position to allow a discharge of liquid typically water from a vessel. The sports cap is removed from a threaded or snap-on connection to allow refilling of the vessel. Each time the vessel is appropriately refilled, one of a plurality of tactile buttons 110 is actuated to tally the refilling of the vessel. The buttons are distributed about an annular track spaced above graduated markings 112 used to indicate the quantity of liquid in the vessel according to the liquid level height. The annular side wall of the vessel is preferably made of plastic and of a sufficient thickness to allow the formation of a plurality of spaced apart tactile buttons having the form of protruding domes or hemispheres 122 each of which are formed by concentric opposite groove crease line(s) 120 . As shown in FIGS. 1, 3 , 4 and 5 , each dome is hemispherical but can take the form of a rectangle, square or other jutted configurations. By this construction, the domes are tactility in an actuated depressed position lying inward from the annular outer surface of the side wall and in a reset, restart position protruding outwardly from the annular surface of the side wall. As shown in FIG. 4A, there is a concentric convolution of a wall portion 124 B joined by web sections 124 C to a central dome 124 A. Wall portion 124 B is joined by web section 124 C to wall 102 . Web sections 124 C form circular grooves functioning as crease lines. More than one wall portion 124 B may be provided and have different arcuate lengths but can comprise the same arcuate length if desired without departing from the spirit of the present invention. The embodiment of a tactile button shown in FIG. 4B includes opposing external and internal circular grooves 125 A and 125 B, respectively, having the same and maximum diameter in the construction of the tactile button. External circular grooves 125 C, 125 D, 125 F and 125 G have diameters that are smaller than the diameters of internal circular grooves 125 H, 125 I, 125 J and 125 K, respectively. The wall material between the internal and external grooves undergo repeated compression and tension in the operation of the tactile buttons. The offset relation between 125 C- 125 G with respect to the respective grooves 125 H- 125 K imparts a resilient biasing force to central dome section 126 to stabilize the section in both of the actuated and un-actuated, restart positions. The embodiment of a tactile button shown in FIG. 4C is the same as shown and described in regard to FIG. 4 B and includes: external and internal circular grooves 125 A and 125 B, respectively; external circular grooves 125 C, 125 D, 125 F and 125 G; and the same offset relation between 125 C- 125 G with respect to the respective grooves 125 H- 125 K. Unlike the other embodiments of the present invention, the embodiment of FIG. 4C provides a planar central wall section 126 A which receives a resilient biasing force to stabilize the planar central wall section 126 A in both of the actuated and un-actuated, restart positions. The embodiment of a tactile button shown in FIG. 4D includes concentrically arranged circular beads 127 A- 127 H interconnected by relatively thin circular wall sections 128 . By this construction and relationship of parts forming the button there is imparted the desired resiliency and stability to a central dome section 129 in both of the actuated and un-actuated, restart positions. In each embodiment of FIG. 4A, 4 B, 4 D and 7 , the dome wall section 124 A, 126 , 129 and 146 may take the form of a planar wall section without departing from the spirit of the present invention. FIGS. 6 and 7 illustrate a second embodiment of the present invention a cylindrical vessel 130 closed by a bottom wall 132 and having a fill opening surrounded by thread bars for receiving a screw cap or snap-on cap 134 providing with a dispensing straw 136 normally closed by a closure cap 138 . The screw or snap-on cap is made of plastic and provided with a plurality of tactile buttons 110 A actuated to tally initial filling and refilling of the vessel. The buttons are distributed about an annular track on a planar end wall 135 of the screw or snap-on cap 134 . Spaced vertically along the cylindrical side wall of the vessel are graduated markings 142 used to indicate the quantity of liquid in the vessel according to the liquid level height. The planar end wall 135 is made with a sufficient thickness of plastic material to allow the formation of concentric opposite grove crease lines 144 encircling each protruding dome 146 . By this construction, the domes are tactility in an actuated depressed position lying inward from the planar end wall 135 of the screw or snap-on cap and in a reset, restart position protruding outwardly from the planar end wall 135 of the screw or snap-on cap. In the use of the present invention, an example is given for a non-active person having a body weight of 224 pounds. A water intake is calculated to be 112 ounces per day at a rate of ½ ounce per pound of body weight. The suggested total number of intake ounces 112 is then divided by the number of waking hours per day at 16 for a total number of recommended intake ounces at 7 per hour. The user fills the bottle to the 7-ounce graduation on the bottle and then within the first hour consumes the water content in the bottle. This event triggers the actuation of one tactile button. The user then refills the bottle to 7 ounces and then within the second hour consumes the water content in the bottle. This event triggers the actuation of another tactile button. At the end of the day, sixteen tactile buttons are in an actuated state. This invention removes all the guess work and easily enables the user to tally daily water consumption accurately. FIG. 8 illustrates a configuration of a tactile button 180 having a characteristic of construction that distinguishes from the construction of tactile buttons described and shown hereinbefore by the provision of smooth outer and inner face surface sections 182 and 184 extending along the transition from the vessel wall 186 of the container to the protruding section 188 of the button. Internal and external circular grooves and all crease lines have been completely eliminated in the embodiment of FIG. 8 . The outer surface section 182 combined with protruding section 188 establish the hemispherical configuration for dome 190 . While the button 180 is shown in FIG. 8 with a hemispherical configuration, the button may take the form of a rectangle, square or other jutted configurations each, however, notably void of a crease line at the junction with wall 186 . The contour of the side wall instead of annular as shown in FIG. 2 can include annular wall sections of diverse radii or annular wall sections interleaved with planar wall sections of various portions. FIG. 9 illustrates a configuration of a tactile button 195 embodying a construction characterized by internally rounded sections 196 joining vessel wall 197 with the internal face surface 198 of hemispherical button 199 . The external surface configuration between vessel wall 197 and the hemispherical button 199 is notably characterized by a demarcation line 200 where the junction between the external surface of vessel 197 abruptly changes by an angular relation that is not rounded in the area of the transition. While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.

A vessel is constructed dispensing and displaying a measured quantity of water by a graduated scale along the side wall of the vessel. The consumption of each measured quantity of water is tallied by actuation of one of a plurality of tactile buttons. In one embodiment, the buttons are distributed about a side wall of the vessel and in a second embodiment, the buttons are distributed about an end wall in a cap attached to the vessel.

BACKGROUND OF THE INVENTION The present invention relates to optical barcode readers and includes an optical signal processing detector that results in a cleaner, more linear electrical signal at the photodiode level. Barcode reading systems, as known in the art, employ a finely focused light beam scanned across a coded label located in the field of view of a photodetector. The label represents information encoded as a series of bars of various widths formed on a contrasting background. The difference in reflectance of the bars versus the spaces produces a modulated optical signal. The optical signal is converted to an electrical signal by a photodetector. This electrical signal is further processed and digitized before decoding. As barcode scanner technology has advanced, the quality of label necessary for accurate reading has decreased. This is highly advantageous in that labels can now be printed by conventional printing methods directly on packaging. Alternatively, computer printed labels can be employed to further automation. Regardless of the system design, all barcode reading systems must address several common, inherent problems: A major concern lies in the nature of the light reflected from barcode labels. Most of the light returned to the detector is diffuse, due to the optically rough surface of the label. It is the difference in this diffuse light to which the detector is sensitized. When labels are printed on smooth, shiny surfaces or are oriented in a particular way, mirror-like reflections can be returned to the detector. These intense specular reflections can overpower the diffuse light signal and introduce a major source of error. A second problem is ambient light. Strong interior lighting or bright sunlight can also overpower the detector and further decrease the signal to noise ratio. A further design consideration is the ideal that the detector receive the same intensity of diffuse light from all points along the scan width. This is a difficult objective to achieve because considerably more light is returned from the central area of the scan than from the periphery. Shotnoise is an additional consideration. Technically, shotnoise is characterized by fluctuations in the current leaving the photodiode. Shotnoise increases with increased photodiode area. Furthermore, when the received light signal is less concentrated over a large photodiode area the signal to noise ratio also decreases. In order to realize the benefits of inexpensive labels and to compensate for these adverse optical signal conditions, barcode reader designers have evolve increasingly expensive and complicated electronic signal conditioning techniques. This invention shows that these shortcomings can be addressed more economically by optical means, resulting in a more accurate electrical signal at the outset. Some of the problems discussed above have been addressed, to a limited extent, in the prior art. U.S. Pat. No. 2,018,963, Land, disclosed the use of a polarization technique to attenuate specular reflections. The method involves polarizing the light source normal to the plane of incidence and viewing the image with an analyzer crossed with the polarizer. U.S. Pat. Nos. 3,812,374, Tuhro, 3,801,182, Jones, and 3,502,888, Stites, employ this technique in various forms. All are based on the fact that specular reflections maintain the same polarization as the incident beam whereas the diffuse light is randomly polarized and will not be absorbed by an analyzer crossed with the incident polarizer. The present invention forgoes the need for an initial polarizer because the diode laser output is inherently polarized. U.S. Pat. No. 3,746,868, Plockl, disclosed the use of narrow-pass wavelength filters as a means to improve the signal to noise ratio in an optical reader by filtering out light of a different wavelength than the optical reader light source, e.g. ambient light. This effective, inexpensive technique is further improved in the present invention. In light of these considerations, it is an object of the present invention to provide an optical barcode reader operable in a wide range of ambient light conditions. It is a second object of the invention to provide an optical barcode reader desensitized to specular reflections. It is a further object of the invention to provide an optical detector assembly for a barcode scanner that gathers a uniform intensity of diffuse light throughout the scan angle. It is an additional object of the invention to provide an optical detector assembly for a barcode reader that minimizes shotnoise produced by the photodiodes. It is yet another object of the invention to provide an effective optical solution to the inherent adverse optical signal conditions encountered by barcode readers, thereby eliminating the need for expensive and complicated electronic signal conditioning techniques. Other objects and advantages of this invention will become apparent when the following detailed description is taken in conjunction with the drawings and appended claims. SUMMARY OF THE INVENTION The present invention achieves these objectives by providing a systematic treatment of the returned light signal that results in a photodiode electrical current of high signal to noise ratio and consistent amplitude over the scan width. This optical signal conditioning takes the form of an improved detector assembly utilizing several cooperating optical elements. The invention employs an optically transparent lens of high index of refraction that is generally prismatic and more specifically, as shown in the drawings, is of pyramidal frusta-like shape to conduct light reflected from the label to a pair of conventional photodiodes. This lens, which can be economically formed of cast plastic, condenses the signal in area. This allows the photodiode area to be minimized. As indicated previously, shotnoise is a function of total photodiode area, so shotnoise will thereby be decreased. The invention also optically improves the signal by other means such as a cross-polarization system to remove specular reflections and bandpass filters to remove the ambient light reflected. In addition, the filters and the input side of the lens are angled to the sides of the label, rather than the center, to ensure that light is received over the entire scan width. To compensate for the increased light intensity received from the center of the label, a strip of opaque material is used to prevent light from entering the center of the lens. These simple, yet significant cooperating elements compose a photodetector that is cost effective to produce and alleviates the need for expensive electrical signal conditioning components. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial side view of the system of directing light to an encoded label and of the optical detector system for processing the reflected light received. FIG. 2 is a pictorial view from below FIG. 1 of the same system for directing light to an encoded label with a more detailed view of the optical detector system. FIG. 3 is an exploded detail view of the detector assembly shown from below the optical detector system as in FIG. 2. FIG. 4 is a front view of the input side of the lens used in the optical detector system. FIG. 5 is a bottom view from below of the lens used in the optical detector system. FIG. 6 is a side view of the lens used in the optical detector system. FIG. 7 is an isometric view of the lens shown in FIGS. 4, 5, and 6. DETAILED DESCRIPTION FIG. 1 shows light being deflected by scanning mirror 4, rotated by motor 5, through laser window 23 of barcode reader housing 31 to encoded label 6. The light is then reflected through polarizer 22 to optical detector 1. FIG. 2 shows light from laser 2 being deflected by scanning mirror 4 on to encoded label 6. Laser 2 produces a monochromatic light beam that is either inherently polarized as in FIG. 2 or polarized by a polarizing element added anywhere between laser 2 and label 6. Scanning mirror 4 is multifaceted and is rotated so that the light beam scans the entire width of the label. Light reflected from label 6 passes through lens 8 where it is condensed in area and thus, concentrated when it leaves the output side of lens 8 to be detected by a photodetector means, which preferably is a dual photodiode system 20. Referring now to FIG. 3, before the reflected light reaches lens 8, it passes through plane polarizer 22 that is a window of reader housing 31. Polarizer 22 is oriented orthogonal to the light directed to label 6 to filter out specular reflections, which are of the same polarity as the light directed to the label. This allows the detector to receive a predominantly diffuse light signal from the white background between the black bars of label 6. Specular reflections from the black bars ar attenuated by the cross (orthogonal) polarization so as not to overpower the diffuse light read from the white spaces between bars. Most of this diffuse signal next passes through bandpass filters 14 and 16 that absorb wavelengths outside a narrow band centered around the laser wavelength, thereby eliminating reflected ambient light. Filters 14 and 16 are angled towards the left and right side of the label 6 respectively to allow them to receive light from the entire scan width. The filters used in the preferred embodiment each have an angle rating of approximately 20 to 25 degrees for a total of 40 to 50 degrees. The scan angle is approximately 60 to 70 degrees. Thus, the filter angle needs to be approximately 10 to 15 degrees for a total of 20 to 30 degrees. The total of the filter angle rating plus the filter angle equal the scan angle. The filter angle should be altered accordingly if the angle rating or the scan angle is altered. In addition, the filters are spaced apart with the space being covered by a strip of opaque material 18. This opaque material 18 further attenuates the signal reflected from the central region of the label 6 ensuring that a more uniform intensity of light is gathered across the scan width. This filter angle/opaque material scheme counters the undesirable characteristic that more light is returned from the center of the scan than from the ends due to the inverse square law and the geometry of the scan. The light passing through the filters is received by the light input side of lens 8. Lens 8 can be formed of any optically transparent material, including plastics such as TYRIL SAN copolymer produced by Dow Chemical U.S.A. This allows the barcode reader to be made for a fraction of the cost of the expensive electrical signal conditioning components as employed in the prior art. FIGS. 4-6 give a more detailed representation of the shape of the lens used in the preferred embodiment. FIG. 4 shows that the width of the input side, represented by line AD, is larger than the width of the output side. The preferred range of narrowing, defined by angle EDF is from 15 to 25 degrees. FIG. 5 is a right side view showing the equally important narrowing of the length of the input side(the dimension going into the page in FIG. 2) to the length of the output side. The preferred range of narrowing in this dimension, defined by angle HDF is from 15 to 25 degrees. This diminishment of cross sectional area is what allows lens 8 to concentrate the signal leaving its output side. FIGS. 4 and 5 also show rectangular protuberance 26, which is used to attach lens 8 to lens subhousing 28. Protuberance 26 also serves as a spacer separating recessed input side planes (or faces) 10 and 12 that receive filters 14 and 16 affixed between the lens subhousing 28 and lens planes 10 and 12 respectively. Protuberance 26 is, formed with pin holes 24, which receive lens mounting pins 19 (ref. FIG. 3) projecting from lens subhousing 28 for locating and holding lens 8 in place. The lens mounting pins 19 and adjacent area of the subhousing 28 also serve as opaque material 18 which blocks reflected light from entering the central area of the lens 8 as described above. This concentrated light signal passes to the photodetection means, preferably a pair of photodiodes 20, mounted on detector wall 21, such as provided by a printed circuit board. Photodiodes 20 transform the light signal into an electrical signal. The pair of photodiodes 20 are connected in parallel to produce an electrical signal representative o the entire light signal received. As indicated above, the signal concentration performed by the lens 8 allows the size of the photodiodes to be minimized, thereby reducing shotnoise. Conventional circuitry (not shown), mounted on base 3 and detector wall 21, processes, digitizes, and decodes the electrical signal without resorting to any special circuitry that would be needed had the novel optical processing described above not been employed. Preferably, the input side of lens 8 consists of planes 10 and 12 angled as discussed above for seating the filters 14 and 16 so that the plane angle is approximately 10 to 15 degrees. Filters 14 and 16 ma be directly affixed to planes 10 and 12 respectively to ensure that the plane angle equals the filter angle. These planes are angled for the same reason that the filters were angled: to ensure that as much light as possible is received from the outboard ends of the label 6. While only particular embodiments have been disclosed herein, it will be readily apparent to persons skilled in the art that numerous changes and modifications can be made thereto including the use of equivalent means and devices without departing from the spirit of the invention.

A bar code reader having a scanned light and a stationary photodetector is disclosed. The photo detector uses a lens having a pyramidal frusta-like body to concentrate light. The input side has a pair of oppositely angles side planes facing opposite extremities of a scanned label. The faces can be used to mount filters to reject ambient light, and a polarizer can be used to reject specular reflection from the scanning laser.

BACKGROUND OF THE INVENTION The present invention relates to a carburetor for IC engines. More specifically, the invention relates to a carburetor comprising an intake duct opening at one end into the atmosphere and connected at the other end with an intake pipe of a manifold of an IC engine. A throttle valve is located in the intake duct so as to essentially completely shut off same in an idling position, and an idling duct bypasses the throttle valve. The idling duct is formed to supply combustion air for the formation of a desired.fuel-air mixture, the fuel being caused to flow by vacuum of the combustion air at a fuel outlet from a fuel duct. The idling duct is formed with a bore constriction upstream from the outlet orifice of the idling duct in the intake duct for the production of a supersonic flow. The invention also relates to an idling insert for such a carburetor which has a housing with a housing body for supporting a connector for fuel and a connector for combustion air. The insert comprises an inner fuel tube connected flow-wise with the fuel connector and an external jet tube connected flow-wise with the connector for combustion air. The jet tube extends, concentrically around the fuel tube with the formation of a support section for support in the carburetor housing, in a direction away from the housing body. A carburetor of this type has been proposed in German Patent Specification No. 2,452,342. In this known carburetor, an idling duct was located within the material of the carburetor housing and primary air was supplied to the fuel in a vertically placed fuel duct through a branch duct arranged at an acute angle for the formation of an emulsion. At the lower end of the fuel duct the emulsion first passed into a plenum for transfer holes, which opened into the intake duct at the position at which the edge of the throttle valve made contact in its closed position. At the side of the plenum opposite the inlet, the fuel duct ran into a further plenum of the idling system, from which the fuel passed through a throttle duct, able to be set by means of a set screw and a projection on the throttle to change its cross section, to a mixing chamber for the addition and mixing of combustion air. On the side of the mixing chamber opposite to the throttle hole the fuel-air mixture passes into a small tube extending under the throttle valve a long distance into the intake duct and on its side adjacent to the mixing chamber it has a stepped choke structure which defines a bore constriction for producing a sonic velocity in the flow in the idling duct. The combustion air is supplied to the mixing chamber from an intake port in the wall of the intake duct over the throttle valve via a choke, which is responsible for the degree of vacuum requisite for causing flow of the fuel from the fuel duct. The degree of vacuum produced in this way in the mixing chamber is considerable, since it has to cause the flow of the fuel out of the adjacent choke port at a velocity which, even initially, was relatively high, and such fuel has to be supplied on the other side of the mixing chamber to the narrow inlet of the choke structure without the mixing chamber being fouled by carbonizing condensate on its wall faces. This has to be achieved despite considerable pressure losses in the plenum chamber for the transfer holes and in the plenum chamber for the idling system with the throttle projection. Consequently, it is necessary for the degree of vacuum of the combustion air in the mixing chamber to be quite high. On the other hand, however, the pressure in the mixing chamber always has to be just twice the pressure in the induction duct if a sonic velocity in the bore constriction is desired. Therefore, if one assumes a pressure in the mixing chamber of 0.75 bar, at which the flow of the emulsion caused is just adequate, the necessary pressure in the intake duct will be only approximately 0.4 bar at the most in order to attain a sonic velocity at the constriction with the ensuing relatively fine atomization desired. Although it may be possible under ideal conditions to construct this carburetor to attain this result during idling, this can be done only under the proviso that the degree of closing of the throttle valve is high and is not impaired by inaccuracies of manufacture or other factors, and under the further proviso that the rated idling speed of the engine is in fact attained; the idling speed may fall to a marked extent on switching on accessories requiring power such as an air conditioning system, a servosystem acting against an abutment or similar equipment and when this occurs the ideal conditions would no longer be fulfilled. A particular reason for such ideal conditions not being complied with is that, when changing over to a partial load phase of operation, the throttle valve is opened only a fraction so that the vacuum in the induction duct falls to some extent and the critical pressure ratio requisite for attaining sonic flow is no longer able to be reached. The necessary consequence of this is that, even in the lower partial load range, desired fine atomization is no longer possible and, even during idling pure and simple, the set condition may very easily be lost so that even the automatic switching on of the air conditioning system may cause the engine to stop. However, in addition, even under ideal conditions which are not able to be permanently adhered to in practice at any rate for any length of time, there is only an incomplete amount of carburetion (in the sense of reducing the fuel droplet diameter down to an almost molecular order of size), because the combustion air exists at a low pressure and moves with a low velocity, and is combined in the mixing chamber with the emulsion (which also enters the mixing chamber as well with a relatively low velocity), such that, at the point of mixing, there will be no substantial effect to decrease the droplet diameter. Accordingly, the fuel-air mixture passes with a relatively large droplet diameter into the flow which is intended to be sonic, and it is only later that a reduction in the droplet diameter by the action of pressure waves is possible. Even if sonic flow is attained in the bore constriction, there will only be a limited degree of subsequent breaking down of the droplets in the mixture and if the sonic flow velocity is not reached, there will be a more or less complete absence of such breaking down of the droplet size. From the original papers of German Pat. No. 2053991 issued to present inventor, it is also known to have an idling system using the transission between subsonic and supersonic flow to produce a vacuum for stimulating flow of fuel and air, and for intimate mixing and distribution thereof. SUMMARY OF THE INVENTION According to the teachings of the present invention, it is desirable to devise a carburetor of the type initially specified herein whose idling system assures stable running of the engine both during idling and also under partial load conditions and furthermore assures optimum preparation of the mixture and a homogeneous supply thereof to all cylinders. In order to achieve this goal, at least the end of a fuel duct is in the form of a tubular nozzle placed in a concentric supply duct for the combustion air and the opening of the nozzle is placed at the bore constriction. Owing to the tubular nozzle form and the concentric arrangement of the fuel duct end in a combustion air feed duct, there is a concentric flow of combustion air around the fuel duct in the same direction as the fuel in this duct and also around the outlet orifice of such duct. This combustion air simultaneously serves for cooling the fuel and for avoiding the formation of vapor bubbles in the fuel which would make it non-homogeneous. Owing to the fact that the orifice of the tubular nozzle is arranged at the constriction in the combustion air duct the fuel is introduced into the combustion air flowing with a sonic velocity and is so broken down into superfine droplets, even during the process of mixing; furthermore pressure surges downstream from the point of admission and mixing lead to a further intensification of the mixing effect and of the homogenization of the mixture, as well as to a further reduction in the size of any large droplets still lingering on in the mixture. The overall effect is therefore that there is a more or less full and true physical gasification of the fuel in the mixture so that it is present therein with an almost molecular state of division. The sonic velocity is produced at the constriction of the cross section with a high degree of certainty, more especially in the partial load range of operation as well, since, for attaining the critical pressure ratio, the entire pressure differential between more or less ambient pressure and the pressure in the intake duct is available, and, even in the case of a pressure increase in the intake duct to over 0.5 bar, it is still possible to ensure sonic velocity at the constriction in cross section. Even on a possible change over from a laval flow to a venturi one, under certain conditions of operation there will still be a very fine atomization and homogeneous mixing effect since only the sonic pressure surges will disappear, while the addition and mixing will still take place in such a way as to profit from the maximum velocity differential possible in this case. Since, even with a high degree of vacuum in the intake duct at the bore constriction there will only be a sonic velocity (and not the supersonic velocity occurring only after flow through the bore constriction), there will be a very stable and constant mode of operation, for all pressure ratios above the critical ratio, with respect to the pumping of the fuel from the fuel duct with an automatically constant metering effect. On slowing down the engine, and when there is an extremely high vacuum downstream from the shut throttle valve (irrespective of the possibility of sudden turning off of the fuel supply), the amount of fuel will thus not be proportionately greater, this possibility being equally excluded even if the engine does not idle at a constant speed. Conversely, this stable manner of operation will also be adhered to in the partial load range providing that the pressure ratio does not go below the critical value owing to a pressure increase in the intake duct. In the case of any likely drop to a value below the critical pressure ratio and a change over to venturi flow, that is to say, for example on acceleration in the upper partial load range, there will admittedly be a change in the conditions of atomization, but all the same atomization will be optimum; and in this connection under such operating conditions no particular importance will be attached to a particularly homongeneous preparation of the mixture in the idling system. Owing to the homongeneous and finely divided preparation of the mixture there is a correspondingly complete combustion process with a reduced emission of contaminants. Accordingly maximum engine power for a given fuel supply rate will be achieved with a minimized output of contaminants into the air. European Patent No. 0 036 524 proposes a carburetion system for producing a sonic velocity in the narrowest cross section of a laval nozzle so as to ensure constant induction conditions in different load ranges under such carburetion conditions. The intention was, however, certainly to produce an air-rich emulsion upstream from the laval nozzle so that the emulsion would be aspirated as such without any addition of combustion air through the laval nozzle. If the sonic velocity is not attained this would then lead to a transfer of the fuel from the outlet orifice and to a corresponding formation of condensate. In the event of the sonic velicity being reached, there would be no remixing of the combustion air moving at sonic velocity with the emulsion introduced into such flow and a substantially worse preparation of the mixture would be probable than in the case of the carburetion system disclosed in the German Patent Specification No. 2,452,342 which is taken as a starting point for the carburetor disclosed herein. In accordance with a preferred feature of the carburetor of the present invention means, such as ports, are provided for the introduction of primary air (for example upstream from the point of introduction of the fuel) into the fuel for emulsion formation. As a result, the carburetion system of the present invention entails a larger mass flow rate through the tubular nozzle, for conveying a given amount of fuel, than is the case when only fuel is caused to flow therethrough. In this case, it is possible to avoid having superfine nozzle orifices, which are difficult to manufacture, and at the same time the danger of fouling the tubular nozzle is minimized. When, in accordance with a further feature of the carburetion system of the present invention, the fuel duct is in the form of a fuel tube placed bodily in the combustion air flow, there is not only a corresponding intensification of cooling by the surrounding air flow but furthermore the possibility of drawing in the primary air through at least one circumferential port in the wall of the duct for forming the emulsion. The arrangement and form of the ports may then be fully in accord with the desired primary air rate and distribution. The primary air supplied to the fuel also serves to cause further cooling of the fuel from the inside. The intensive cooling so ensured not only minimizes the danger of vapor bubble formation but at the same time increases the thermal efficiency. Since emulsion is not formed upstream of the fuel tube (which so serves as a mixing tube) it is more effectively possible to avoid separation of the air and fuel as components of the mixture than would be the case if the primary air were to be introduced at a point far upstream from the supply of the fuel or of the emulsion into the combustion air. In keeping with a further feature of the carburetor of the present invention, there is a terminal bore constriction (more especially to a bore cross sectional area between 0.03 and 0.3 sq mm or preferably to about 0.12 sq mm) in the fuel duct for the emulsion with a relatively small, but not extremely small, size. As a result, in view of the present strong vacuum, there will be an effective control of the desired metering of the fuel without any excess thereof. Since no throttling of the supply of fuel is aimed at upstream from the fuel duct (such throttling would otherwise cause unnecessary losses in the flow), it may be, in order to draw in a defined and desired amount of primary air, an advantage in addition to suitably dimensioning the ports in the wall of the duct to have a pre-choke upstream from such ports in order to ensure a suitable degree of vacuum in the fuel duct. This pre-choke may be in the form of a constriction of the fuel duct to a reduced bore area (more specifically to an area of 0.03 sq mm to 0.3 sq mm and preferably 0.12 sq mm) in tune with the desired pressure and flow conditions sought. As a rule, the optimum cross sectional area will be the same as that of the constriction in the tubular nozzle, it having however to be taken into account that in the assumed preferred case the nozzle is for emulsion while the pre-choke constriction is for fuel alone. The port or ports in the fuel tube are intended, under the pressure conditions which become established, to meter in a certain amount of air to mix with the fuel and form the emulsion, and may then preferably have a total cross section of between 0.1 sq mm and 1.0 sq mm or, more especially, approximately 0.45 sq mm. In place of a single large port it is more expedient to have a plurality of small ports, which are more readily produced with the desired cross sectional area as part of the process of manufacture, and which prevent any unintentional discharge of fuel under transient conditions, more especially if they are on the top side of the fuel tube. The preferred dimensions of the separate bore constrictions of 0.03 sq mm to 0.3 sq mm (preferably 0.12 sq mm) for the tubular nozzle, of 4 sq mm to 40 sq mm (preferably approximately 16 sq mm) for the supply duct for combustion air, of 0.03 sq mm to 0.3 sq mm (preferably approximately 0.12 sq mm) for the pre-choke and of between 0.1 sq mm and 1.0 sq mm (preferably approximately 0.45 sq mm) for the port for the entry of primary air, result in optimum running conditions for a 2.8 liter engine. For engines with other cubic capacities the optimum values within the ranges set forth above will be larger or smaller, although the relationship between the dimensions will be substantially the same. Despite the absence of air ports in the fuel line in view of the introduction of primary air only at the outlet end of the idling duct, in order to safely prevent the drawing in of fuel from the float chamber during pauses in operation, it is possible to have a valve for shutting off the fuel line (more specifically at a point upstream from the fuel tube) automatically. If this valve is placed as close as possible to the outlet of the idling duct, this will also serve to minimize the amount of fuel which necessarily drips out of the fuel duct when there is a pause in operation. In keeping with a further feature of the carburetor of the present invention, it is expedient to have the air duct and/or the fuel duct of the idling duct in the form of tubes standing free of the carburetor housing. Apart from the reduction in design and manufacturing costs being less than for carburetors having the ducts within the carburetor housing, this means that with regard to the air duct, there will be a respective freedom with regard to the design of the upstream connection of the air line which does not have to be directly connected with the air filter, but may also be in the form of a branch from the cylinder head air vent duct so that even at a point upstream from the air filter it is possible for the oil mist in the filter to be drawn off, possibly with the addition of air from the air filter which is drawn through the section, leading to the air filter, of the cylinder head venting duct. With regards to the fuel duct, the design in the form of a duct standing out from the side of the carburetor housing gives the special advantage of cooling the hot fuel drawn in from the float housing. This is more especially of value in countering hot start problems. In order to prevent an excessive amount of heat being transferred from the hot wall of the carburetor to the downstream end of the fuel line, something that would be prone to cause irregular operation owing to the formation of bubbles of vapor in the fuel line, the latter duct may end in a connector supported in a connecting part of material with a low thermal conductivity, more especially plastic. This avoids the direct transfer of heat from the hot metal parts. As part of a further feature of the carburetor of the present invention, the fuel line is arranged to terminate in the connector with its axis placed transversely in relation to the axis of the fuel duct, this making it possible to save space here as is usually desired. In accordance with still a further feature of the carburetor of the present invention, the arrangement serves to form an annular trap chamber for any small vapor bubbles tending to move back out of the fuel pipe and likely to coalesce as large vapor bubbles causing irregular running if they are allowed to get into the fuel line. The connector extends downwards through the trap chamber to form its inner wall face. The inlet port of the fuel duct is placed to the side above the level of the outlet orifice of the connector. Any small vapor bubbles tending to move out of the fuel tube are thus caught in the trap chamber and stopped from transferring into the lower outlet orifice of the connector of the fuel line so that there is no interruption in the continuous supply of the fuel therethrough. The vapor bubbles whose size are in any case limited to the volume of the trap chamber, may be drawn again into the fuel duct during the course of further flow of the fuel and may emerge with the fuel or the emulsion thereof without causing any irregularity, from the fuel duct into the combustion air flow. In accordance with an even further feature of the carburetor of the present invention, the arrangement is such that the cross section of the flow of fuel from the flow chamber to the inlet port of the fuel tube, that is to say the cross section of the fuel line, of the connector thereof, of its outlet orifice, of the trap chamber and of the point of transfer from the outlet orifice to the trap chamber, is at least approximately constant. This results in an even flow velocity and an insensitivity with respect to transients such as vibrations, different slopes on traveling up and down hill, the formation of dead zones and the like. For not only simplifying production, but more especially to make possible fitting to existing systems, it is possible for the outlet part, having the fuel duct of the idling duct, to be in the form of a separate housing, which has a nozzle tube (forming the combustion air duct) adapted to be fitted to extend through the wall of the carburetor housing and/or of the intake duct, respectively, as for example at a position adjacent to a base plate of the carburetor. Adaptation to suit the respective operating conditions may be made possible by providing adjustable means for securing the precise position of the port of the fuel duct in relation to the cross section bore constriction in the combustion air duct so that, if required, fine adjustment may be undertaken on any IC engine without, normally, any later adjustment being needed. In order to ensure a particularly low loss inlet flow and efficient acceleration into the supersonic range before detachment and flow transition take place, the bore constriction in the combustion air duct may be in the form of a converging-diverging laval nozzle. As a further feature of the carburetor of the present invention, the axis of the outlet part of the idling duct may be at an angle of 0° to 30° and more especially at an angle of at least about 10° to the center axis of the intake duct. Furthermore, the axis of the outlet part of the idling duct may be at an angle (as seen in a horizontal plane) of 15° to 40° and more especially of about 20°. to a line drawn radially from the center axis of the intake duct, such angle being measured at the point of intersection of the axis of the outlet part of the said idling duct with the prolongation of the outer face of the intake duct. With such slopes of the axis of the outlet part of the idling duct in a downward and in a lateral direction towards a more tangential flow it is possible to minimize the vacuum at the outlet orifice of the idling duct and to optimize the mixing effect, more particularly in the partial load range. The introduction of the mixture from the idling system, with a high velocity but with a limited mass flow rate therefore, has the tendency to keep the mixture flowing in a helical flow path running downwards in the intake duct or pipe, respectively, this favoring a progressively complete mixing with the mixture flowing past the throttle valve with minimum flow losses. While the downward slope more especially makes a contribution to minimizing the flow losses and, in the partial load range, to increasing the local vacuum at the outlet orifice of the idling duct the inclination to the side is more especially helpful with regard to improving the mixing effect; since at this point in time the fuel is already in a practically "carbureted" or gasified form, there is little risk of centrifugal separation of fuel droplets and the formation of condensate, more especially since the flow at the same time enters the substantially widened intake tube owing to the downward motion. In accordance with still another feature of the carburetor of the present invention, a housing is provided having a housing body for supporting a connector for fuel and a connector for combustion air as well as an inner fuel tube connected with the fuel connector for flow therebetween, and an outer nozzle tube connected with the combustion air connector for flow therebetween, the nozzle tube extending away from the housing body concentrically around the fuel tube to form a support portion for the support of the carburetor housing. This feature of the carburetor of the present invention constitutes an idling insert fitting which is a separate and compact part produced separately from the carburetor so that it may be sold for modification of a pre-existing carburetor. This possibility of production and distribution of such separate components has a special degree of importance as part of the present invention, since it makes possible the use of the teachings of the invention independently from mass produced articles coming from automobile and carburetor manufacturers so that the invention may be put into practice at the option of the consumer or car owner and he or she may make his own contribution to economizing in the use of energy and protecting the environment. Furthere details, features and beneficial effects of the carburetor of the present invention will be apparent from the following description of one working embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic and simplified generally vertical sectional view of a carburetor constructed according to the teachings of the present invention. FIG. 2 is an enlarged longitudinal section through the outlet part of the idling duct of the carburetor shown in FIG. 1. FIG. 3 is a top plan view, partially in section, of the outlet part of the idling duct shown in FIG. 2 viewing same from above. DESCRIPTION OF THE PREFERRED EMBODIMENT A carburetor is shown in FIG. 1 with an air filter 1, a carburetor housing 2 and an intake duct 3 passing through the housing 2 for the aspiration of outside air through the air filter 1. The carburetor housing 2 includes a base plate 4 for connection with an intake pipe 5 of an intake manifold 6, which supplies the cylinders of an IC engine in a conventional manner with fuel-air mixture and on which the base plate 4 is mounted using a conventional gasket 7. A butterfly throttle valve 8 is located in the intake duct 3 so as to practically fully close the intake duct 3 in the idling setting. The carburetor shown is in the form of a governor carburetor and has an intake duct 9 of a second stage, whose throttle valve 10 starts to open when there is a substantial increase in the engine speed. In a conventional manner, the carburetor housing 2 is produced as a casting and in addition to the base plate 4 has two superposed housing parts 11 and 12, the section in FIG. 1 being such as to run along the axes of the intake ducts 3 and 9 in the base plate 4, while on the other hand adjacent to the housing parts 11 and 12 it runs through a plane in front of it extending through a float chamber 14. Under the control of a float 13, fuel moves into the float chamber 14, whence the fuel is abstracted via a fuel line 15 in the form of a stiff or flexible pipe 15 standing free from the side of the carburetor housing 2. Oil mist, as produced in the crank case and the entire engine block, is supplied through a cylinder head vent line 16 to the air filter 1. In the illustrated embodiment, the cylinder head vent line 16 does not run directly to the air filter 1 but into an air line 17 connected with the air filter 1. The fuel line 16 and the air line 17 form parts of an idling duct structure generally identified with reference numeral 18, with which the fuel and the air may be supplied to an idling system opening into the intake duct 3 downstream from the throttle valve 8. The other features of the carburetor, as for example an accelerating pump, may be of a conventional design and are therefore not in need of explanation here. It does, however, remain to be stressed that the throttle valve 8 of the carburetor of the present invention has to stand in a setting in which it practically completely shuts off the intake duct 3 of a first stage so that essentially no air flow is possible past the edge of or through the throttle valve 8 and there are no ducts, or at any rate no open ducts, which would lead to leakage of air. At the edges of the throttle valve 8 in its idling setting it is posssible to have conventional transfer ports 19, if there is no other transfer system, for the supply of mixture in the transitional stage of operation between idling and partial load. The outlet part 20 of the idling duct structure 18 is shown in more detail in FIGS. 2 and 3. As shown in these Figures, the fuel line 15 comes to an end in a connector 21 and the air line 17 ends in a connector 22, the connectors 21 and 22 being supported in a housing 23, which essentially consists of a jet nozzle tube 24 for the formation of a supply duct 25 for the combustion air around a fuel tube 26, which forms a fuel duct 27. Furthermore, adjoining a supporting portion 28, formed essentially by the nozzle tube 24 to fit into the carburetor wall 2, the housing 23 comprises a rear housing body 29 adjacent to the connectors 21 and 22 with end faces 30 next to the supporting portion 28 and a connection part 31 of material with a low thermal conductivity as for example plastic in the instant case, whereas all other parts are made of metal. At its front end, the fuel tube 26 has a tubular nozzle 32 with a bore constriction 33 having a cross section of, for instance, 0.12 sq mm, the same also forming a port 34 for the emergence of fuel or emulsion, as the case may be. In its rear top part the fuel tube 26 has round, axially spaced, ports 35 which, in the present example, are two in number and have a diameter of 0.5 mm and 0.6 mm, respectively, that is to say with a sum cross section of approximately 0.45 sq mm. Such ports make possible flow of the air from the flow around the fuel tube 26 into the fuel duct 27 so that a fuel emulsion is formed therein. A pre-choke 36 is located upstream from the ports 35 and in the present example it is in the form of bore constriction 37 with a cross sectional area of 0.12 sq mm. The fuel duct 27 opens, by way of an inlet port 38, into a trap chamber 39 through which the connector 21 of the fuel line 15 extends and which is machined in the connection part 31 of plastic. An outlet port 40 of the connector 21 is in this case lower than the lower edge of the inlet port 38 of the fuel duct 27 and therefore also at a lower level than the trap chamber 39 so that on the supply of fuel from the outlet port 40 of the connector 20 via the trap chamber 39 into the inlet port 38 of the fuel duct 27 there is a sort of inverted syphoning effect. The tubular nozzle 32 with the bore constriction 33 of the fuel tube 26 is placed in a constriction 41 upstream from an outlet port identified by reference numeral 42, of the idling duct structure 18 into the intake duct 3. The constriction 41 is in this respect in the form of a sort of convergent-divergent laval nozzle so that if a critical pressure differential or ratio between the planes A and B is exceeded in the constriction 41, there will be a flow with a sonic velocity and in the following somewhat diverging part of the nozzle tube 24 there will be a supersonic velocity, until detachment and flow transition occur. In the case of a supercritical pressure differential this will be, at the latest, in the plane B, that is to say in the plane of the outlet port 42. In the present example, the bore constriction 41 has an area of cross section of approximately 16 sq mm, this being believed to be the size for optimum operation of a 2.8 liter engine. The fuel tube 26 and the nozzle tube 24 are placed concentrically about an axis 43 that intersects the axis 44 (which is perpendicular to it) of the connector 21 of the fuel line 15. Furthermore the axis 45 of the connector 22 of the air line 17 is perpendicular to the axis 43 but does not have to intersect with it. As shown in FIG. 3, the connection part 31 together with the fuel tube 26 is swivel mounted in the housing body 29, with corresponding turning of the connector 21 being provided for since the connector 21 runs in a slot 46 in the housing body 29. The axis 47 of the slot 46 is not perpendicular but is at an angle to the axis 43 so that the swivel movement of the connection part 31 and of the fuel tube 26 with a rocking of the connector 21 also leads to an axial motion of the fuel tube 26. This makes possible accurate adjustment of the position of the port 34 of the tubular nozzle 32 in relation to the constriction 41 in accordance with specific requirements. In the present case, the length of the slot 46 is intended to allow a twist of the connection part 31 of 30° and is set at an angle of 13° obliquely in relation to the axis 43 so that the amount of adjustment is of the order of 1 mm. For assembly in the position shown in FIG. 1, it is possible for the entire nozzle tube 24 to be inserted into a suitable hole in the carburetor housing 2 until it abuts the front end faces 30 of the housing body 29. As already indicated, in connection with the description of FIG. 1, the axis 43 may be inclined at an angle to the horizontal, the angle having a possible range of approximately 0° to 30° and in the present case it may have a value of 10° owing to design limitations occasioned by the overall height of the base plate 4. In a manner which is similar, but which is not illustrated, the axis 43 does not have to intersect with the center axis of the intake duct 3 and it is possible for there to be an oblique setting of the axis 43 clear of the radial setting such that the emergency of the flow from the outlet port 42 is more tangentially directed into the interior of the intake tube 3. Such an angle to the radial direction may be between 15° and 40° and, in the present case, may be taken to be 20° as measured at the point of interference, generally identified by reference numeral 48 in FIG. 1, of the axis 43 with the extension of the outer face of the intake duct 3. During idling the throttle valve 8 is closed so that the vacuum produced in the intake duct 3 downstream from the throttle valve 8, owing to the intake strokes of the pistons, acts in full on the outlet port 42 and through the latter in the idling duct structure 18. The result is that air is firstly drawn in through the air duct 17 and the oil mist present in the cylinder head vent line 16 will be entrained as well, such mist being supplemented by air from the air filter 1. This air current will only undergo a small drop in pressure so that the pressure in the plane A will be more or less atmospheric and at the intake duct 3 adjacent to the outlet port 42 there will be, for example, a pressure of only 0.4 bar. This means that the critical pressure ration between the planes A and B has been substantially exceeded so that a sonic flow will establish itself in the plane of the constriction 41 and will be followed by a supersonic flow. Owing to the marked pressure drop in the inlet part of the bore constriction 41 and the change over from static pressure into dynamic pressure of the air flow, there will be a correspondingly intense suction effect on the fuel thereat through the port 34 of the tubular nozzle 32 and fuel therefore will be supplied through the constriction 33 to the air flow at a metered rate. At the same time, however, primary air will be drawn from the air flow around the connector 22 through the ports 35 at a point upstream from the tubular nozzle 32 and introduced into the fuel tube 26 where it will form a fuel air emulsion with the fuel in the fuel tube. Thus, at the port 34, the fuel in the form of such an emulsion will pass into the combustion air flowing in the supply duct 25, such entry being at a position at which there is an extremely large velocity differential owing to the sonic velocity of the combustion air. As a result, the fuel, emerging with a very much lower velocity, will be broken down into very small droplets and atomized so that downstream from the constriction 41 there will be a fuel-air mixture with the desired lambda value having a very homogeneous distribution, at least at the outlet port 42. At the latest, at the outlet port 42 there will then be a further disintergrating effect on any large droplets still present owing to the pressure surge when there is a flow transition to an ultrasonic value. In the manner indicated in FIG. 1, a flow emerges downwards and sideways from the outlet port 42 and passes into the intake tube 3. It flows turbulently through the tube 3 and fills it very rapidly and homogeneously with finely divided fuel in particles with a more or less molecular order of size. This condition remains unchanged as long as the critical or supercritical pressure differential is maintained between the planes A and B, in which respect even a highly supercritical pressure differential or ratio hardly causes any change in the atomization state at the constriction 41, since the velocity is always supersonic at this position. In the event of the pressure differential being subcritical under full load or in transient conditions, as for instance during acceleration, the part of the nozzle tube 24 between the planes A and B will function as a venturi tube, in which respect, however, the supply of the fuel will be at the point of maximum velocity differential between the combustion air flow and the fuel so that, in these conditions as well, optimum atomization still takes place, although it is of only slight importance under such load conditions. It is, however, important that in steady state conditions, a critical pressure ratio exist far into the partial load range so that the ideling mixture will be supplied under constant, stable conditions. Furthermore, the oil mist from the cylinder head vent duct 16 is supplied to such idling mixture in the way indicated directly, or via the air filter 1, so that the mist is dealt with in a manner conducive to economy in energy and to protection of the environment. Since the fuel is supplied via the fuel line 15 without any notable pressure losses, it may be expedient to step up the degree of vacuum in the fuel duct 27 at the port 35 in order to guarantee the requisite input of primary air. This is made possible by the pre-choke 36, the cross sectional area of the constriction 37 thereof being adapted, on the one hand, to the desired pressure drop and, on the other hand, to the overall pressure drop as far as the port 34, in order to attain a desired exit velocity for the emulsion. Typically, the size of the area of the constriction 37 will be, dependent on the engine cubic capacity, between 0.03 sq mm and 0.3 sq mm. In view of the selected cross section size of 0.12 sq mm of the constriction 33 through which the emulsion flows, in the present example, a cross section size of 0.12 sq mm can be selected for the constriction 37 having fuel alone flowing through it. In the case of the selected summated cross section of the ports 35 of approximately 0.45 sq mm there will be an optimum formation and propulsion of the emulsion through the tubular nozzle 23 under the action of the combustion air, which always flows through the constriction 41 with a sonic velocity. A size of the cross section at the constriction 41 of approximately 16 sq mm then leads to a supply of combustion air to the flowing fuel at such level as to ensure a properly ignitable mixture and at such a rate that, in the case of a 2.8 liter engine the idling speed, will be 600 to 700 rp. The choking constrictions 33 and 37 are not able to prevent fuel syphoning from the float chamber 14 of its own accord if the engine stops, since access of air into the fuel line 15 is not possible upstream from the connector 21. For this reason the fuel line 15 is provided with a valve 49 which automatically shuts off the fuel line 15 below a head, for instance, of 4 cm of gasoline in the line. Therefore, at the most, only dribbling of fuel downstream from the valve 49 will be possible. The volume of such fuel may be minimized and, owing to the complete shutting off at the level of the valve 39, it will only be able to flow (if at all) slowly; it is in this way that the amount of fuel leaking, in the case of the illustrated form of the carburetor of the present invention, may be limited to the content of the fuel tube 26 downstream from the ports 35. The connection part 31 made of material with a low thermal conductivity prevents any substantial transfer of heat between the hot peripheral wall of the housing body 29 and the connector 21 and also the fuel tube 26, it being significant in this respect that the connector 21 is fitted in the slot 46 with some lateral play. This means that the cooling of the fuel tube 25 by the surrounding combustion air flow in the supply duct 26, and also by the primary air drawn in through the ports 35, still will be effective, even in the rear part of the fuel tube 26, so that the same will be relatively cool even at the inlet port 38. Transfer of any vapor bubbles, nevertheless formed in the fuel tube 26, into the fuel line 15 is prevented by the trap chamber 39, since vapor bubbles tending to move back towards the fuel line 15 will be retained at the uper wall of the trap chamber 39 until they are moved (perhaps after increasing somewhat in size and bulging to a greater extent down into the fuel space) back into the fuel tube 26 and leave it together with the fuel or the emulsion (as the case may be) via the port 34, something that does not give rise to any irregularities in operation. Owing to the fact that the cross section area of the fuel line 15, of the connector 21, of the annular trap chamber 39 and of the transition between the outlet port 40 and the trap chamber 39 have been designed to be generally equal in size, there will be a regular flow of the fuel between the float chamber 14 and the inlet port 38 of the fuel tube 26 and such flow will be unlikely to be disturbed, and more especially in the case of a relatively high flow velocity through a small cross section, will make a substantial contribution to avoiding the formation of vapor bubbles, even under very unfavorable conditions. The working example of the carburetor of the present invention described above leads to the advantages described initially herein; a more significant point, in this respect, is that the relatively high pressure at the plane A makes it possible for the critical pressure ratio to be maintained far into the partial load range so that consequently more regular operation of the idling system may be ensured. Since, furthermore, in the partial load range as well, a corresponding flow is maintained through the idling system, and such flow may certain constitute a substantial part of the fuel-air mixture made available for the cylinders, the optimum operation, at any rate, of this part leads to a significant increase in mileage and a drop in contaminant emission in the partial load ranges as well. For achieving a maximum vacuum in the idling setting the throttle valve 8 can be fully closed in this position--with the possible exception of small gaps caused by manufacturing tolerances. This position of the throttle valve 8 in the idling setting does also form the basis for the indicated metering of the ducts of the idling system. However, a certain problem might arise if the transfer port 19 which is usually provided as concentrical elongated slot is also shut off completely in this position by the edge of the throttle valve 8 from the vacuum below the throttle valve 8, since then, with the transition to the partial load range, there may occur a nonsteady phase with a fuel supply reduced as against the desired value because of said load, i.e., an "acceleration gap", since the flow of the transfer port 19 proceeding from the previous zero-flow starts with delay. For avoiding such nonsteady states of operation it can also be provided that the edge of the throttle valve 8 comprises a small gap with a maximum diameter of e.g. 0.2 to 0.3 mm to the wall of the intake duct 3 in the idling setting, i.e. that the throttle valve 8 does not completely shut off the flow in the intake duct 3 but only throttles it. In such a case there is, also in the idling setting, a certain basic flow of fuel and/or emulsion from the transfer port 19 and a corresponding air supply from the intake duct 3. With an appropriate compensation of said additional fuel and air supply by a respectively reduced fuel and air supply from the idling duct means 18 there are the same operating conditions as with the above embodiment. The carburetor of the present invention has a number of advantages, some of which have been described above, and others of which are inherent in the invention. Also modificaitions can be made to the carburetor of the present invention without departing from the teachings of the present invention. Accordingly the scope of the present invention is only to be limited as necessitated by the accompanying claims.

A carburetor with an idling system is designed so that the full pressure differential or gradient available between approximately ambient pressure and the vacuum in the intake tube is employed for producing a critical pressure ratio of a supersonic flow in a laval nozzle. To make this possible, a fuel air emulsion formed with primary air is introduced from a mixing duct via a constricted orifice of a tubular nozzle at a bore constriction, at which there is always a sonic velocity when there is a critical and supercritical pressure ratio, into the secondary air flow where it is superfinely atomized in the secondary air flow, with a maximum velocity differential, aided by subsequent pressure surges. At least at a point far into the partial load range of operation, the idling system produces a homogeneous mixture which is homogeneously distributed in the intake tube with a practically molecular state of division so that it is even supplied to all cylinders of the engine and completely combusted with a minimum production of contaminants.

STATEMENT OF RELATED APPLICATION This application claims the benefit of priority to U.S. Provisional Patent Application No. 60/277,026, filed Mar. 19, 2001, entitled “SYMMETRIC LINE CODING”. BACKGROUND OF THE INVENTION High bandwidth optical communications systems typically use continuous wave (“CW”) lasers, passing through an intensity modulator, to encode and transmit data. The light emitted by the laser has a very narrow frequency spread, characteristic of a coherent light source. The modulator is driven by high bandwidth electrical signals. These signals spread the frequency spectrum of the light to roughly twice the bandwidth of the modulating electrical signals. However, generating these high bandwidth electrical signals is expensive using conventional arrangements, and the resulting spread of the optical spectrum limits the spacing of separate frequency channels in a wavelength division multiplexed system. SUMMARY OF THE INVENTION The aforementioned problems are addressed by an arrangement for symmetric line coding in accordance with the invention. A method an apparatus for symmetric line coding is provided where a binary input signal d is received; a value for each of a pair of binary bits p and q are dynamically defined in response to the input stream; and a pair of output bitstreams v 1 and v 2 are dynamically generated in accordance with the following: if d=1, then v 1 =p and v 2 =p, and if d=0, then v 1 =(1−q) and v 2 =q. In illustrative embodiments of the invention, the generation may be performed by symmetric-line coding machines, including: a bitstream symmetric line coding machine, a regular bitstream symmetric line coding machine, a complementary regular bitstream symmetric line coding machine, a binary complementary regular symmetric line coding machine, a bitstream parallel symmetric line coding machine, a regular bitstream parallel symmetric line coding machine, a complementary regular bitstream parallel symmetric line coding machine, and a binary complementary regular parallel symmetric line coding machine. In other illustrative embodiments, the inventive arrangment is couple to a modulator, for example a Mach-Zender modulator. Advantageously, the arrangement of the present invention reduces the bandwidth requirements of the electrical signals, so that these signals are more easily produced, and further reduces the spread of the optical spectrum, so that channels may be spaced more closely. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 depicts a simplified block diagram of an illustrative embodiment of a Binary Complementary Regular Bitstream symmetric line coding machine in accordance with the invention; FIG. 2 depicts simplified block diagrams of driver circuits that are operationally coupled with modulators in accordance with the invention; FIG. 3 depicts an illustrative block diagram of an 8 bit-parallel bus symmetric line coding machine in accordance with the invention. DETAILED DESCRIPTION Most systems use a signaling format known as On-Off Keying (“OOK”). In OOK, the light from a laser is modulated such that a low amplitude signal represents one logical state (a “0” state, for instance), while a high amplitude signal represents another logical state (a “1” state). These two logical states, representing the data bit values 0 and 1, are propagated along the transmission line repetitively once each clock period (sampling instant), T. Equipment at the receiving terminal detects the intensity of the light signal, reconstructs the clock, samples the light intensity at each clock interval, and decides whether a 0 or 1 data bit was transmitted. The electric field of the light modulated onto the optical fiber may be described according to its radio-frequency (“RF”) electric field envelope and the underlying optical carrier field. The envelope contains the RF field amplitude, together with the complex phase of the field. An OOK signal has an envelope that takes on values of 0 or 1 at each sampling instant. More complex line codes take on other values at each sampling instant. For instance, phase shift keying takes on values in the set {−1, +1}, while Alternate Mark Inversion (“AMI”) takes on values in {−1,0, +1}. The envelope may be represented as a data symbol multiplied into a unit modulation pulse. In this way, a Non-Return-to-Zero (“NRZ”) OOK signal may be represented as a full duty cycle modulation pulse, multiplied by a data amplitude in the set {0,1}. This may be expressed as the convolution of the unit modulation pulse with a train of impulses, each carrying a weight given by the data amplitude. The power spectrum of the light on the transmission fiber is determined from the RF envelope. When the envelope is represented as the convolution of modulation pulse and data amplitude impulse train, the power spectrum is simply the product of the Fourier transform of the modulation pulse and that of the impulse train. The transform of the impulse train is expressed in terms of its autocorrelation. For this reason, correlations in the data amplitudes introduce structure into the transmission power spectrum. It is control of these correlations, and the associated shaping of the power spectrum, that is the goal of line coding. The optical power spectrum of the transmission may be calculated from the autocorrelation of the line code. The electric field envelope, E(t), is made up of unit modulation pulses, emitted at each clock period, T, weighted by the output symbols, b k . This may be written as a convolution of an impulse train, weighted by the output amplitudes, with the unit modulation pulse, E ( t )=Σ b k ·p ( t−kT )=Σ b k ·δ( t−kT ) p ( t ). The power spectral density is the product of the line code spectral density and that of the unit modulation pulse, S (ω)= S L (ω)·| P (ω)| 2 . The line code power spectral density is, explicitly, S L ⁡ ( ω ) = 1 T ⁢ ∑ n = - ∞ ∞ ⁢ R n ⁢ e i ⁢   ⁢ n ⁢   ⁢ ω ⁢   ⁢ T 0 , for ⁢   ⁢ R n = 〈 b k ⁢ b k + n * 〉 , ( 1 ) where the autocorrelation coefficient, R n , is calculated over the statistical expectation of output symbol products. The unit modulation pulse spectral density is P ⁢ ( ω ) = ∫ - ∞ ∞ ⁢ p ⁢ ( t ) ⁢ e - i ⁢   ⁢ ω ⁢   ⁢ t . The line code power spectral density, S L (ω), provides a means to control the spectrum of the transmission by controlling the correlations between output symbols. These relations demonstrate that spectral shaping may be effected without changing the modulation pulse itself. The intellectual property contained in this document will comprise invention of spectral shaping line codes, and their implementations, to control the spectrum of transmission of optical signals, and the mitigation of impairments suffered in propagating through optical fiber. The line code power spectral density may be computed for OOK, S OOK ⁡ ( ω ) = 1 4 ⁢ T + 2 ⁢   ⁢ π 4 ⁢ T 2 ⁢ ∑ n = - ∞ ∞ ⁢ δ ⁡ ( ω - 2 ⁢ π ⁢   ⁢ n T ) , ( 2 ) where the first term on the right hand side represents a flat frequency-independent spectrum, and the second term, narrow peaks at multiples of the clock frequency. The flat spectrum uses requires bandwidth out to very high frequencies, causing channels to be broadly spaced. The narrow spectral peaks, which result from the phase coherence of the light source, are problematic due to nonlinear propagation effects in optical fibers. Both of these issues are addressed by line coding. The power spectral density for the ASI line code is S ASI ⁡ ( ω ) = 1 4 ⁢ T ⁢ ( 1 + cos ⁢   ⁢ ω ⁢   ⁢ T ) = 1 2 ⁢   ⁢ T ⁢ cos 2 ⁢ ω ⁢   ⁢ T 2 , ( 3 ) from which it is evident that the spectrum has been shaped to have a null at the Nyquist frequency, ω Nyquist =π/T. This narrows the spectral bandwidth, and allows closer channel spacing. It also reduces the impact of dispersive propagation impairments. Each bit of the output symbol may be mapped onto the contacts of a Mach-Zehnder (“MZ”) modulator. The MZ modulator divides the incoming light into two waveguides, applies a variable and independent phase shift, φ 1 and φ 2 , to each, and recombines them at the output The effect is to generate an optical field at the output with electric field envelope proportional to E ˜[ exp( iπ·φ 1 )+exp( iπ·φ 2 )]/2. The phase shifts may be configured such that, for two input bits, v 1 and v 2 , the phase shits satisfy φ 1 =(v 1 +v 2 )/2 and φ 2 =−(v 1 +v 2 )/2, so that E ∼ cos ⁡ ( π · v 1 + v 2 2 ) , so that the sum of the two input bits determines the output state. When (v 1 , v 2 )=(0,0),then E˜1; when (v 1 , v 2 )=(0,1) or (v 1 , v 2 )=(1,0) then E˜0; and when (v 1 , v 2 )=(1,1), then E˜−1. Alternatively, the phase shifts may be configured such that φ 1 =(v 1 −v 2 )/2 and φ 2 =−(v 1 −v 2 )/2, and the difference of the output bits determine the modulator output. Other alternatives include complementing either or both of the output bits, v 1 and v 2 . The ability to drive a modulator with the sum or difference of two output bits enables the following beneficial aspect: transitions in the output of the modulator may be effected by transitions of either of the two inputs, independently. This provides a means to reduce the frequency with which the two binary inputs make transitions. This translates directly into reduced requirements for the electronic and optical components. In order to take advantage of this opportunity, some method of signal processing is required to produce the correct signals, v 1 and V 2 , to be used to drive the modulator contacts. This method is line coding, a broad category of which will be described by symmetric line coding machines. The symmetric line coding machine of the present invention may be described in the following way. The unique input symbols form a set, {d 1 , . . . , d n }. For each input symbol, there is associated a pair of output symbols, forming a set, {{P 1 ,Q 1 }, . . . , {P n ,Q n }}. Each time the machine receives an input symbol, d k , it produces an output symbol from the appropriate set, {P k ,Q k }. The symbols P k and Q k may, or may not, be unique. For at least one k, P k and Q k must differ. For each k, the first time that input d k is received, output P k is produced. Subsequently, for each k, whenever input d k is received, either P k or Q k is output, according to the following rule. Upon receiving input d k , determine the most recent prior occurrence of the same input d k , and which output symbol, from the set {P k ,Q k }, was produced for that input. If the number of intervening input symbols, between the current input d k and the most recent prior occurrence of d k , is an odd number, then produce whichever output symbol, from the set {P k ,Q k }, was not emitted in the most recent prior instance of input d k . Otherwise, produce the same output symbol, from the set {P k ,Q k }, that was emitted in the most recent prior instance of input d k . An example of such a machine follows. Let the input symbol set be {d 1 , d 2 , d 3 }, and the output set be {{P 1 ,Q 1 }, {P 2 ,Q 2 }, {P 3 ,Q 3 }}. Suppose the input symbol sequence is d 1 d 2 d 3 d 1 d 3 d 3 . Then the output sequence would be P 1 P 2 P 3 P 1 Q 3 Q 3 . The first output is P 1 , since it is the first instance of input d 1 . The second output is P 2 , since it is the first instance of input d 2 . The third output is P 3 , since it is the first instance of input d 3 . The fourth input is d 1 , so count the number of input symbols between this instance of d 1 and the most recent prior instance of d 1 , at which time output P 1 was produced. There are two such inputs, d 3 and d 2 , so the same output symbol, P 1 , is produced as was produced most recently when input d 1 was received. The fifth input is d 3 , for which there is one other symbol, d 1 , intervening between this input and the most recent prior input of d 3 , for which the output symbol was P 3 . One is an odd number, so the output symbol is not P 3 , but instead is Q 3 . The sixth input is d 3 , corresponding to output symbol Q 3 . The immediately prior input was d 3 , also, so there are zero other symbols intervening. Zero is not an odd number, so the output symbol is the same as for that input, Q 3 . Several specific symmetric line coding machine machines are now described. The Bitstream symmetric line coding machines is a symmetric line coding machines in which each input symbol, d k , is a sequence of binary digits (bits). Likewise, each output is a sequence of bits. The Regular Bitstream symmetric line coding machine is a symmetric line coding machine in which each input symbol, d k , is a sequence of n bits, and each output symbol is a unique sequence of n+1 bits. The Complementary Regular Bitstream symmetric line coding machine is a symmetric line coding machine in which each input symbol, d k , is a sequence of n bits, each output symbol is a unique sequence of n+1 bits, and for each input symbols, d k , the two corresponding output symbols, P k and Q k , are bitwise complements of each other. The Binary Complementary Regular Bitstream symmetric line coding machine is a Complementary Regular Bitstream symmetric line coding machine with n=1. An illustrative embodiment of the Binary Complementary Regular Bitstream symmetric line coding machine is depicted in FIG. 1 . The binary input, d, is processed to produce binary output pairs, (v 1 ,v 2 ). The symmetric line coding modulator, in accordance with the invention, is the application of each of the output bits of a Binary Complementary Regular Bitstream symmetric line coding machine to the two contacts of a MZ modulator, as depicted in FIG. 2 . The two output bits are amplified by drive amplifiers, and the resulting signal applied to the contacts of the modulator. The power spectrum of the electrical signal applied to each contact of the modulator is described by Eq (3). For the symmetric line coding machines Modulator, the electric field envelope of the optical transmission is described by the ASI line code. The optical spectrum is also described by Eq. (3), so that a null is driven into the power spectrum of the transmitted light. This significantly lowers the high frequency content of the transmission, producing narrower channels, and allowing channels to be more closely spaced. Parallel symmetric line coding machines are now described. It may be desirable to have the input symbols presented to the symmetric line coding machine on a set of N parallel input lines, and the symmetric line coding machine output applied onto a set of M parallel output lines. At the input, a rule is established for identifying the sequence order of the inputs on each of the parallel input lines; at the output, a rule is established for identifying the sequence order of the outputs on each of the parallel output lines. Given these two rules, the contents of the input lines are processed to produce the contents of the output lines according to the operation of a symmetric line coding machine. Several specific parallel-symmetric line coding machine are now described. The Bitstream parallel-symmetric line coding machine is a parallel-symmetric line coding machine in which each input symbol, d k , is a sequence of binary digits (bits). Likewise, each output is a sequence of bits. The Regular Bitstream parallel-symmetric line coding machine is a parallel-symmetric line coding machine in which each input symbol, d k , is a sequence of n bits, and each output symbol is a unique sequence of n+1 bits. The Complementary Regular Bitstream parallel-symmetric line coding machine is a parallel-symmetric line coding machine in which each input symbol, d k , is a sequence of n bits, each output symbol is a unique sequence of n+1 bits, and for each input symbols, d k , the two corresponding output symbols, P k and Q k , are bitwise complements of each other. The Binary Complementary Regular Bitstream parallel-symmetric line coding machine is a Complementary Regular Bitstream parallel-symmetric line coding machine with n=1. An illustrative embodiment of Binary Complementary Regular Bitstream parallel-symmetric line coding machine is now described. An embodiment of a parallel symmetric line coding machine, shown in FIG. 3 , teaches how to construct logic for an 8-bit parallel bus. The inputs, labeled d 0 through d 7 , are processed to produce the outputs, labeled v 1 0 through v 1 7 and v 2 0 through v 2 7 . The output symbol pairs are (v 1 ,v 2 ). The ordering is first d 0 , next d 1 , . . . , finally (d 7 , and likewise on the output. Other embodiments of the invention may be implemented in accordance with the claims that follow.

A method an apparatus for symmetric line coding is provided where a binary input signal d is received; a value for each of a pair of binary bits p and q are dynamically defined in response to the input stream; and a pair of output bitstreams v 1 and v 2 are dynamically generated in accordance with the following: if d=1, then v 1 =p and v 2 =p, and if d=0, then v 1 =(1−q) and v 2 =q. In illustrative embodiments of the invention, the generation may be performed by symmetric-line coding machines, including: a bitstream symmetric line coding machine, a regular bitstream symmetric line coding machine, a complementary regular bitstream symmetric line coding machine, a binary complementary regular symmetric line coding machine, a bitstream parallel symmetric line coding machine, a regular bitstream parallel symmetric line coding machine, a complementary regular bitstream parallel symmetric line coding machine, and a binary complementary regular parallel symmetric line coding machine.

BACKGROUND OF THE INVENTION [0001] The invention relates to a method for monitoring the synchronism of transmitters in a common wave network. [0002] Transmission technology of terrestrial radio and television is based on a network of regionally distributed transmitters which transmit synchronously at the same transmitter frequencies (common wave network). The technology of common wave networks could only be achieved with the introduction of digital transmission methods in which, according to the transmission standard, protective intervals (guard intervals) are provided which make it possible to have a specific tolerance range for different transit times of the transmission signals from the individual transmitters because of different distances. Modern digital multicarrier methods (e.g. OFDM=orthogonal frequency division multiplexing) of digital radio (DAB=digital audio broadcasting) and of digital terrestrial television (DVB-T=digital video broadcasting terrestrial) are therefore based nowadays on common wave networks. [0003] A functioning common wave network requires that each receiver of the common wave network receives an adequate signal level of the transmission signal at any arbitrary location within the transmission range of the common wave network and that the transmission signals received from the individual transmitters are synchronous within a specific tolerance range (protective or guard interval with DVB-T). [0004] Because of the most varied of interferences—e.g. too little transmission power of a transmitter, defective synchronisation of a transmitter to the common wave network, different weather conditions in the transmission region of the common wave network etc.—the requirements of synchronism and adequate signal level can be unfulfilled for an interference-free reception in the common wave network. In addition, interfering signals from interfering transmitters and echo signals intruding into the common wave network can be superimposed upon the useful signals as a result of reflection of useful signals on obstacles. Constant monitoring with respect to synchronism and signal level of the received useful signal and also with respect to freedom from interfering signals in the entire transmission range must therefore be implemented. When infringement of these obligatory network requirements occurs, the interfering source—e.g. transmitter, supply route, obstacle—must be identified and a correct and functioning network operation must be produced again by corresponding remedial measures. [0005] A method is presented in DE 196 42 633 A1 in which a transit time difference measurement between the receiving signals of two transmitters of the common wave network is implemented in order to determine the exact receiver location in a common wave network. Since the receiving signal includes not only the useful signal but also can contain echo signals, the latter must be identified and screened out. For unequivocal identification and screening out of occurring echo signals, the transmission characteristic of the transmission channels of both transmitters is determined by measurement of the channel impulse response. [0006] In DE 199 37 457 A1, building on this method of transit time difference measurement, by determining the channel impulse response of the transmission channels of two transmitters of a common wave network, a method is described for monitoring transmitters in a common wave network. In order to determine the synchronism of the transmitters of a common wave network, the transit time differences respectively of two transmitters are hereby measured by a radio receiver and compared with a reference transit time difference of the same two transmitters. In the case of too great a deviation of the transit time differences which represents a lack of synchronism of the two tested transmitters, the transmitters subject to interference are informed by the radio receiver via a central office with respect to renewed synchronism. [0007] The disadvantage of this method is the merely paired comparison of the transit times of two transmitters with respect to the synchronism of two transmitters relative to each other. The synchronism of a plurality of transmitters, in particular a transmitter group which is connected to the central office via a common supply route cannot be determined in this way. Reliable and unequivocal error source identification with respect to error sources which have an effect on only one single transmitter (e.g. phase detuning of a single transmitter) and error sources which have an effect on a transmitter group (e.g. transmission errors in the supply route to the transmitter group) cannot be achieved with this method. [0008] Because of the merely paired comparison of the transit time differences of two receiving signals, the method has the further disadvantage that only relative asynchronism between two transmitters to be surveyed can be identified, whereas the absolute asynchronism of the respective transmitters relative to a reference transmitter and hence to the entire common wave network is not possible. If the transmitters to be surveyed have for example equal asynchronism relative to the reference transmitter, then they are synchronous relative to each other and are therefore by this method judged falsely as synchronous relative to the common wave network. [0009] In the case of merely paired comparison of the transit time differences of the received useful signals of two transmitters, only one time-determining variable is used respectively for one transmitter—the receiving time of the received useful signal measured by the receiver. Taking into account a plurality of time-determining variables—for example the receiving times measured by the receiver of the echo signals associated with one transmitter—is not effected so that no additional information with respect to a more unequivocal and exact determination of the causal error source is possible in this way—e.g. time delay of the receiving signal due to a bad weather situation in a specific transmission area of the common wave network. SUMMARY OF THE INVENTION [0010] A need therefore exists to develop a method for monitoring the synchronism of transmitters in a common wave network such that, on the one hand, unequivocal monitoring of the absolute synchronism of all the transmitters integrated in one common wave network is possible and, on the other hand, conclusions can be drawn from the measurement of an occurring asynchronism as unequivocally and easily as possible with respect to the error source or at least to the type of error source of the occurring asynchronism. [0011] In contrast to the merely paired comparison of the synchronism of two transmitters, the reference impulse response of the strongest transmitter to the pilot impulse response is defined according to the invention on the basis of a reference measurement and all the remaining reference impulse responses of the remaining transmitters with respect to their synchronism relative to the common wave network are applied to the pilot impulse response within the framework of a transit time measurement. In this way, it is possible within the framework of a further measurement of all impulse responses associated with the individual transmitters—summation impulse response—to determine the number of asynchronous transmitters by comparison with all corresponding reference impulse responses—reference summation impulse response—and, dependent thereon, to determine the synchronism error class of the occurring synchronism error. The determination of the synchronism error class represents an important step with respect to identification of the synchronism error source or of the synchronism error type. [0012] If only a temporal deviation between a measured impulse response and the associated reference impulse response occurs and hence asynchronism of only one transmitter relative to the common wave network, then in the case of a synchronism error of this type of the first synchronism error class, the error source in the respective transmitter can be located quite specifically. [0013] In contrast, if time deviations occur between measured impulse response and associated reference impulse response in the case of a plurality of but not all remaining n−1 transmitters of the common wave network, then in the case of synchronism errors of this type of the second synchronism error class, synchronism error sources which relate to a transmitter group can be traced more specifically (e.g. transmission errors in a supply route to one transmitter group, bad weather area in a specific transmitter area etc.) [0014] A time deviation between all n−1 remaining measured impulse responses and the associated reference impulse responses leads to a synchronism error of the third synchronism error class. In the case of synchronism errors of this type, possibly solely the strongest transmitter of the common wave network associated with the pilot impulse response can be detuned also with respect to level and also phase. This specific case can be determined via a correlation analysis between reference summation impulse response and summation impulse response. [0015] In addition to monitoring the synchronism, the method can also be used to monitor the correct signal level of the individual transmitters of the common wave network. In the case of a deviation of the signal level of the measured impulse response relative to the reference impulse response, the transmitter power of the respective transmitter must be correspondingly adapted. [0016] The individual reference impulse responses of the reference summation impulse response preferably have error tolerance ranges respectively in the dimension of time and of the signal level which classify a synchronous transmitter with adapted signal level if its measured impulse response is in this error tolerance range. [0017] Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF THE DRAWINGS [0018] An embodiment of the invention is represented in the drawing and described subsequently in more detail. There are shown: [0019] FIG. 1 an overview representation of a common wave network; [0020] FIG. 2 a graphic representation of the reference summation impulse response with error tolerance ranges; [0021] FIG. 3 a graphic representation of the error tolerance ranges of the reference impulse responses, the measured impulse responses and interference impulses; [0022] FIG. 4 a tabulated representation of the error tolerance ranges of the reference impulse responses, the measured impulse responses and interference impulses; [0023] FIG. 5 a graphic representation of the effect of time windows of the Fourier transformation on identification of impulses; [0024] FIG. 6 a a graphic representation of intersymbol interferences in the case of a lack of synchronism of transmitters and [0025] FIG. 6B a graphic representation of the summation impulse response after a synchronisation process. DESCRIPTION OF THE PREFERRED EMBODIMENT [0026] The method according to the invention for monitoring the synchronism of transmitters in a common wave network is described subsequently in an embodiment with reference to FIG. 1 to 6 B. [0027] According to FIG. 1 , a common wave network 1 comprises for example the transmitters 2 , 3 , 4 , 5 , 6 and 7 , which are distributed in the transmitter region and a central office 8 . In this exemplary common wave network 1 , the transmitters 2 , 3 and 4 are combined into a first transmitter group 9 and the transmitters 5 , 6 and 7 into a second transmitter group 10 . The first transmitter group 9 is connected to the central office 8 via a first common supply route 11 , whilst the second transmitter group 10 is connected likewise to the central office 8 via the second common supply route 12 . The coupling of the transmitters 2 , 3 and 4 to the first supply route 11 is effected via a first distribution device 13 , whilst the coupling of the transmitters 5 , 6 and 7 to the second supply route 12 is effected via a second distribution device 14 . The central office 8 couples in a coupling device 15 into the first supply route 11 and into the second supply route 12 . A receiving device 16 is used to measure and monitor the common wave network 1 . The receiving device 16 can be used in a stationary or portable manner, a reference impulse measurement of the individual transmitters requiring to be implemented for each new location with respect to level and phase in the case of a portable receiving device. The transmitters 2 , 3 , 4 , 5 , 6 and 7 and also the central office 8 and receiving device 16 are fitted respectively with a receiving antenna 17 and a transmitting antenna 18 . In the represented example, the feedback from the receiving device 16 at the central office 8 is effected by wireless. If this feedback is effected via a line, the transmitting antenna 18 can be dispensed with there. [0028] The receiving device 16 serves on the one hand to identify areas in the transmission range of the common wave network 1 which have either absolutely no reception or only too weak reception for example because of obstacles 19 in the transmission channel between transmitter and receiver. Echoes due to reflections of the transmission signal on large-area bodies 20 (e.g. mountains) can also be detected with a receiving device 16 of this type. In the case of interference of this type, remedial measures can for example be repositioning or adjustment of the transmitting power of individual transmitters. [0029] In addition to these tasks of monitoring the signal level of the transmission signal and the generation of echo signals, the receiving device 16 also implements measurement and monitoring of the synchronism of the transmitters 2 , 3 , 4 , 5 , 6 and 7 which are integrated in the common wave network 1 . [0030] According to the method according to the invention, the receiving device 16 is positioned at selected positions within the transmission range of the common wave network 1 . For each of these positions, the impulse response for the corresponding transmission channel from the transmitter to the receiving device 16 is determined for each transmitter 2 , 3 , 4 , 5 , 6 and 7 of the common wave network 1 by the receiving device 16 . This can be effected for example by means of pilot carriers (scattered pilot) in the case of a DVB-T signal, as is known fundamentally from DE 100 05 287 A1. The first measurement of the impulse response serves as reference measurement for subsequent measurements. The impulse response determined in the first measurement represents therefore a reference impulse response. The reference impulse responses of all transmission channels associated with the transmitters 2 , 3 , 4 , 5 , 6 and 7 are represented as reference summation impulse response 30 in the form of an echo pattern according to FIG. 2 in time-dependent graphics 64 of a graphics system 55 which is integrated in the receiving device 16 or in a device connected to the receiving device 16 - for example a personal computer connected via internet to the receiving device 16 . [0031] The reference impulse response 20 of the strongest transmitter—for example transmitter 4 —is defined as pilot impulse 29 in order to determine the relative temporal displacement of the remaining reference impulse responses 21 (transmitter 2 ), 22 (transmitter 7 ), 23 and 24 (transmitter 3 ), 25 (transmitter 6 ), 26 , 27 and 28 (transmitter 5 ) at any reference point, the pilot impulse. As reference point for the remaining reference impulse responses 21 , 22 , 23 , 24 , 25 , 26 , 27 and 28 , the pilot impulse 29 is set at the origin of the coordinate system 53 of the graphics 64 , comprising the abscissa 31 and the ordinate 32 . The abscissa 31 forms the receiving time of the reference impulse response in the dimension of microseconds or in the distance dimension of kilometres or miles corresponding thereto. The ordinate 32 represents the signal level of the reference impulse response relative to the signal level of the pilot impulse 29 in the dimension of decibels. [0032] Because of the temporal referencing of the remaining reference impulse responses 21 , 22 , 23 , 24 , 25 , 26 , 27 and 28 to the pilot impulse 29 , pre-echoes are produced which represent reference impulse responses which are received by the receiving device 16 temporally before the pilot impulse 29 (reference impulse responses 21 and 22 ). Analogously, post-echoes are produced which are received as reference impulse responses by the receiving device 16 temporally after the pilot impulse 29 (reference impulse responses 23 , 24 , 25 , 26 , 27 and 28 ). [0033] Since the reference summation impulse response 30 for subsequent measurements of impulse responses by the receiving device 16 serve as reference echo pattern and subsequent measurements of the impulse responses, also in the case of exact synchronism of the participating transmitters 2 , 3 , 4 , 5 , 6 and 7 , are associated with a specific deviation between the reference impulse responses and the measured impulse responses, introduction of a specific error tolerance range 31 , 32 , 33 , 34 , 35 , 36 , 37 and 38 about the respective ideal value pair, reference receiving time and reference signal level of the respective reference impulse response 21 , 22 , 23 , 24 , 25 , 26 , 27 and 28 , is recommended. Hence an individual error tolerance range 31 , 32 , 33 , 34 , 35 , 36 , 37 and 38 is defined by the operator of the receiving device 16 for each reference impulse response 21 , 22 , 23 , 24 , 25 , 26 , 27 and 28 , said error tolerance range preferably comprising an error tolerance band 39 in the time dimension and an error tolerance band 40 in the signal level dimension. However an error tolerance band 39 in the time dimension can suffice. [0034] In a measurement subsequent to the reference measurement, in turn the impulse responses 41 , 42 , 43 , 44 , 45 , 46 , 47 and 48 of the transmitters 2 , 3 , 4 , 5 , 6 , 7 and 8 of the common wave network 1 are received by the receiving device 16 and mapped as summation impulse response 52 in the coordinate system 53 of new time-dependent graphics 65 of the graphics system 55 in such a manner that the measured impulse response 53 of the strongest transmitter 4 comes to lie precisely at the origin of the coordinate system 53 of the new graphics 65 . [0035] In addition to the measured impulse responses 41 , 42 , 43 , 44 , 45 , 46 , 47 and 48 of the transmitters 2 , 3 , 4 , 5 , 6 , 7 and 8 of the common wave network 1 , also interfering impulses 49 , 50 and 51 are also measured by the receiving device 16 , said interfering impulses being generated for example by transmitters 55 , 56 and 57 from neighbouring cells and intruding in the transmission range of the common wave network 1 . These are likewise mapped in the coordinate system 53 of the new graphics 65 of the graphics system 55 corresponding to their receiving time and their signal level. Since the error tolerance ranges 31 , 32 , 33 , 34 , 35 , 36 , 37 and 38 of the reference impulse responses 21 , 22 , 23 , 24 , 25 , 26 , 27 and 28 of the reference measurement are likewise mapped according to FIG. 3 in the coordinate system 53 of the new graphics 65 of the graphics system 55 , the operator of the receiving device 16 can identify the impulse responses which lie outwith the defined error tolerance range of the corresponding reference impulse responses relatively easily. [0036] In the exemplary measurement which is illustrated in FIG. 3 , a no longer tolerable time displacement between reference impulse response and measured impulse response occurs in the impulse response 45 , from which a conclusion can be drawn with respect to the synchronism error between the strongest transmitter 4 and the transmitter 6 . [0037] In addition, in the exemplary measurement illustrated in FIG. 3 , it is evident that the signal level of the measured impulse response 46 appears outwith the tolerable error tolerance range 36 , in particular below the error tolerance band 40 in the signal level dimension of the error tolerance range 36 . The signal level of the impulse response 46 which is too low relative to the signal level of the associated reference impulse response 26 can for example be attributed to too low a transmission power of the transmitter 5 or too great attenuation of the transmission signal from the transmitter 5 to the receiving device 16 because of for example a bad weather period in the transmission channel from the transmitter 5 to the receiving device 16 . [0038] In addition to the graphic representation of the summation impulse response 30 in graphics 65 of the graphics system 55 , also a representation of all received impulse responses 41 , 42 , 43 , 44 , 45 , 46 , 47 and 48 and of all interfering impulses 49 , 50 and 51 is possible in a Table 56 according to FIG. 4 , said table being produced and constantly updated by a processing system 87 in the receiving device 16 . Table 56 contains the following columns: Column 57 with the title of the transmitter of the received impulse, Column 58 with the type of received impulse (useful signal, echo signal, interfering signal), Column 59 with the measured receiving time of the received impulse, Column 60 with the error tolerance limits, defined by the operator, of the receiving time of the received impulse, Column 61 with the measured signal level of the received impulse in relation to the signal level of the pilot impulse, Column 62 with the error tolerance limits defined by the operator of the signal level of the received impulse and Column 63 with a statement relating to the coincidence between measured impulse and error tolerance range of the corresponding reference impulse. [0046] In Table 56 in FIG. 4 , the corresponding values of the exemplary measurement are plotted in the graphic representation of FIG. 3 . [0047] Those impulse responses respectively which do not fall temporally into the error tolerance ranges of the corresponding reference impulse responses are identified for each measuring process by the processing unit 57 of the receiving device 16 . [0048] If only one single impulse response of the measurement is detected outside the respective error tolerance range, then there is a high probability that the corresponding transmitter is not synchronised with the common wave network 1 . A synchronism error of this type concerns an error of the first synchronism error class. Accordingly, if a deviation relative to the respective error tolerance range is established by the processing unit 57 only in the case of a measured impulse response, then this synchronism error is assigned to the first synchronism error class and a corresponding first alarm A 1 is set off. [0049] If in the case of a common wave network with n transmitters the n−1 impulse responses measured in addition to the pilot impulse response are monitored with respect to their coincidence with the corresponding error tolerance ranges by the processing unit 57 and if in the case of at least two and simultaneously less than n−1 of these impulse responses a lack of coincidence is produced, then there is a synchronism error of the second synchronism error class. This is established by the processing unit 57 and a corresponding second alarm A 2 is set off. A synchronism error of the second synchronism error class can concern an error in a transmitter group, for example the first transmitter group 9 or the second transmitter group 10 of FIG. 1 . By means of the transmitter identification of the measured impulse responses of the summation impulse response 52 , a synchronism error of this type of one transmitter group can be identified. [0050] If in the case of a common wave network with n transmitters all n−1 impulse responses do not fall into the corresponding error tolerance ranges, then the transmitters of all n−1 impulse responses can be synchronous with each other, whilst the strongest transmitter of the common wave network, the impulse response of which serves as pilot impulse response of the common wave network, transmits asynchronously relative to the common wave network. This special case is identified by a correlation analysis between the measured n−1 impulse responses and the corresponding n−1 reference impulse responses. If the result thereby is a correlation between the measured n−1 impulse responses and the corresponding n−1 reference impulse responses, then this special case of a synchronism error is present which leads to classification in the third synchronism error class and to triggering of a third alarm A 3 by the processing unit 57 . [0051] The alarms A 1 to A 3 are supplied together with the corresponding measured echo patterns according to FIG. 3 by the receiving device 16 to the central office 8 in order to implement there corresponding evaluations and analyses for concrete error location and, building thereon, to implement corresponding remedial measures to synchronise all the transmitters 2 , 3 , 4 , 5 , 6 and 7 of the common wave network 1 in the range of the transmitter 2 , 3 , 4 , 5 , 6 and 7 , of the supply routes 11 and 12 etc. [0052] Determination of the summation impulse response 65 is effected in general by an inverse Fourier transformation from the transmission function of the transmission channel which is produced by the sum of the signals of all the transmitters 2 , 3 , 4 , 5 , 6 and 7 participating in the common wave network 1 . The incentive for the transmission channels to determine the summation impulse response 65 is effected by so-called pilot carriers (scattered pilots) which, on average for example with DVB-T in each third carrier, are disposed in a transmission frame of the OFDM-modulated transmission signal and are modulated individually by a 2-PSK-modulation—in contrast to the QAM-modulated useful data carriers. The summation impulse response 65 has a periodic temporal course since the frequency spectrum of the summation impulse response 65 is present periodically scanned only at the pilot carriers in the frequency range. Since pilot carriers occur only in each third carrier, the carrier spacing between the pilot carriers is higher by the factor 3 than the carrier spacing Δf T between each individual carrier. Consequently, the permissible time range of the summation impulse response ΔT Imp relative to the useful interval ΔT Nutz of an OFDM-modulated transmission signal is smaller by a factor 3 (Δt Imp =Δt Nutz /3=1/(3*Δf T )). The permissible time range of the summation impulse response Δt Imp can, in the case of alternative methods for determining the summation impulse response 65 , adopt other values (when determining the summation impulse response 65 by means of inverse Fourier transformation from the FIR and IIR filter coefficient of an equaliser integrated in the receiving device 16 , the permissible time range Δt Imp is produced from the filter length of the FIR and IIR filters). In order to avoid intersymbol interferences due to transit time differences, a protective interval Δt G is defined which emerges from the useful interval Δt Nutz according to FIG. 5 and in which no evaluation of the superimposition signal is effected by the receiving devices 16 . [0053] The time window ΔFFT of the discrete Fourier transformation for determining the discrete summation impulse response 65 corresponds to the duration of the useful interval Δt Nutz of an OFDM-modulated transmission signal. Because of varying positioning of the time window ΔFFT of the discrete Fourier transformation within the total symbol length Δt S of an OFDM-modulated transmission signal (Δt S =Δt G +Δt Nutz ), the result can be different relative positions between the permissible time range of the summation impulse response Δt Imp and the protective interval Δt G . [0054] In the extreme case I (ΔFFT=ΔFFT 1 ), the time window ΔFFT covers the beginning of the entire symbol length Δt S , whilst the protective interval Δt G covers the end of the entire symbol length Δt S . In this case, pre-echoes, in FIG. 5 for example the impulse response 66 , do not lead to intersymbol interferences since the impulse response 66 was detected as a pre-echo and is situated in the protective interval Δt G . If as a result impulse responses which represent pre-echoes with respect to the strongest power impulse response (at 0 dB, 0 μs) are expected in the summation impulse response 65 , then the positioning of the time window ΔFFT is chosen as in the extreme case I. [0055] In the normal case (case II: ΔFFT=ΔFFT II ), the time window ΔFFT covers the end of the symbol length Δt S , whilst the protective interval Δt G covers the beginning of the symbol length Δt S . Post-echoes, in FIG. 5 for example the impulse response 67 , do not lead to intersymbol interferences since the impulse response 67 is situated in the protective interval Δt S . If consequently impulse responses which represent post-echoes with respect to the strongest power impulse response (0 dB, 0 μs) are expected in the summation impulse response 65 , then the positioning of the time window ΔFFT is chosen as in case II. [0056] If consequently with a set error tolerance range in the pre-echo range, for example error tolerance ranges 31 and 32 in FIG. 3 , a corresponding impulse response, for example impulse response 41 and 42 in FIG. 3 , is not registered by the receiving devices 16 because either the corresponding signal level is too weak or not present at all, then as a result of the method according to the invention for monitoring the synchronism of transmitters in a common wave network, in addition to the error tolerance ranges 31 or 32 corresponding error tolerance ranges are set at points in time which are displaced temporally forwards exactly by the period length of the summation impulse response 65 (=Δt Imp ) relative to the pre-echo points in time and function in the permissible time range of the summation impulse response Δt Imp as error tolerance ranges. In this way, the echoes, which come to lie in the permissible time range of the summation impulse response Δt Imp when choosing the time window ΔFFT corresponding to the extreme position ΔFFT II , said echoes corresponding to the pre-echoes lying outwith the permissible time range Δt Imp of the summation impulse response 65 because of the periodicity of the summation impulse response 65 , can be identified reliably and unequivocally by the receiving device 16 . [0057] If a constructed common wave network 1 has not yet been balanced, the result can be error interpretations of the temporal position of the impulse response 69 lying outside the permissible time range Δt Imp because of the periodicity of the summation impulse response 65 . An impulse response 69 lying outside the permissible time range is repeated in the permissible time range Δt Imp as impulse response 69 ′ or 69 ″ because of the periodicity of the summation impulse response. Since these repeated impulse responses 69 ′ and 69 ″ lie within the intersymbol interference-free time range Δt G , the delay of this impulse response is interpreted erroneously as insignificant although the original impulse response 69 leads to an intersymbol interference. [0058] This undesired intersymbol interference can be eliminated or detected by temporal displacement of the transmission signal of the transmitter which leads to the impulse response 69 . The temporal displacement is chosen thereby so large that the impulse response falls into the time range of the protective interval Δt G . The delay of the transmission signal into the range outside the permissible time range Δt Imp of the summation impulse response 65 effects, as represented in FIG. 6B , a reduction in the signal level of the impulse response 69 ″ folded in the permissible time range Δt Imp in the measurement of the impulse response. If a time displacement of the impulse response 69 by two periods occurs, then the signal level of the impulse response 69 ′″ which is displaced temporally into the permissible time range Δt Imp of the summation impulse response 65 is reduced in addition. [0059] A false interpretation of the temporal delay of an impulse response can be detected also by the modulation error rate MER (modulation error rate=20 * log (average amount of the symbol amplitude/average amount of the error amplitude)). If the delay of an impulse response lies within the protective interval Δt G , this can be compensated for by the channel estimation and the modulation error rate has a high value corresponding to the other signal quality. If however the delay of the impulse response lies outside the protective interval, the modulation error rate deteriorates. [0060] The invention is not restricted to the illustrated embodiment. It is suitable not only for OFDM-modulated multicarrier methods, such as DAB and DVB-T but also for single carrier methods, e.g. for VSB (Vestigial Side Band) methods of the ATSC standard which is used in North America for digital television broadcasting. In addition, all the above-described features can be combined with each other in any manner. [0061] While the present invention has been described in connection with a number of embodiments and implementations, the present invention is not so limited but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims.

A method for monitoring the time synchronization of a total of n transmitters in a common wave network is described in which a reference total pulse response is compared with a measured total pulse response belonging to the transmission channels of the n transmitters of the common wave network. A reference pulse response is fixed in the reference total pulse response in relation to the pilot pulse response, on the basis of which the remaining reference pulse responses are references to classify synchronization errors in the common wave network in various synchronization error categories.

FIELD OF THE INVENTION [0001] The invention relates to a graphene tape. In particular, it relates to the manufacture, the application and possible uses of such a graphene tape. BACKGROUND OF THE INVENTION [0002] Researchers are demonstrating that 2D, 1D and 0D materials (known as nanomaterials) can be attractive for device applications since they may improve the characteristics and/or confer novel characteristics to such devices. They confer properties that may make them attractive both for the improvement of current applications and the development of novel applications. However, methods for the mass production of these materials are yet to be properly developed, particularly when it comes to deviation from the traditional transfer and fabrication process. [0003] Since the synthesis of these materials is normally not optimal or compatible with the device substrate, they will have to be transferred from their growth surface and deposited on the surface. These processes will rely on the use of sacrificial layers that are initially deposited on the nanomaterials and are later removed once the transfer process is completed. Typically, polymers such as poly(methyl methacrylate) (PMMA) or polydimethylsiloxane (PDMS) have been used since they are commonly used in micro and nanofabrication processing. The use of these sacrificial layers during the transfer processes will normally result in the degradation of the nanomaterials in the form of (chemical) contamination and/or mechanical damage. Also, after the transfer, this poor quality graphene is further processed in order to pattern graphene layouts, to define electrical contacts and/or to prevent it from additional chemical and/or chemical degradation. SUMMARY OF THE INVENTION [0004] In a first aspect of the present invention, there is provided a graphene tape suitable for applying on a target surface, the tape comprising: (a) a support layer; and (b) a first nanocomposite layer, the nanocomposite layer comprising a thin film layer and a graphene layer, wherein the thin film layer is disposed between the support layer and the graphene layer. [0005] Preferably, the thin film layer is a non-sacrificial thin film layer. More preferably, the thin film layer is adapted to provide a functionality to the graphene layer. [0006] Preferably, the thin film layer is a polymer. More preferably, the thin film layer is any one selected from the group comprising: polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF) and its copolymers (e.g. polyvinylidene fluoride-co-trifluoroethylene (P(VDF-TrFE)), poly(3-hexylthiophene) (P3HT) and polylactide (PLA). [0007] Preferably, the graphene layer is a matrix of graphene embedded in a thin film. [0008] Preferably, the graphene tape further comprising a second nanocomposite layer disposed on the support layer on a surface opposite the first nanocomposite layer. [0009] Preferably, the nanocomposite layer comprising a plurality of alternating thin film layers and graphene layers. [0010] Preferably, the graphene tape further comprising an adhesive layer disposed between the support layer and the nanocomposite layer, wherein the thin film layer is disposed between the adhesive layer and the graphene layer. [0011] Preferably, the graphene tape further comprising a first protector layer disposed on the support layer on a surface opposite the nanocomposite layer. In addition, the graphene tape may further comprise a second protector layer disposed on the nanocomposite layer on a surface opposite the support layer. [0012] Preferably, the graphene layer is patterned. By “patterned”, it is meant to also include any modification and/or functionalization. The graphene layer may be functionalised according to the description of graphene. The thin film layer may also be modified but this could be considered part of the thin film deposition process which will be described in detail later. [0013] Preferably, the target surface is any one selected from the group comprising: silicon wafers, glass, quartz, mica, polyethylene terephthalate (PET), polyimide foils and paper, and any other surface that has been prepared on such substrates. [0014] In a second aspect of the present invention, there is provided a method of forming a graphene tape, the method comprising: (a) providing a substrate; (b) forming a graphene layer on the substrate; (c) depositing a thin film layer on the graphene layer; (d) applying a supporting layer on the thin film layer; (e) removing the substrate [0015] Preferably, the method further comprising the step of applying a protector layer in place of the substrate. [0016] Preferably, the thin film layer is a non-sacrificial thin film layer. [0017] Preferably, the thin film layer is adapted to provide a functionality to the graphene layer. [0018] Preferably, the method further comprising cleaning the graphene layer prior to depositing a thin film layer on the graphene layer. [0019] Preferably, the step of depositing the thin film layer on the graphene layer is any one selected from the group comprising: bar-coating, spin coating, spray coating, polymer evaporation, Langmuir-Blodgett deposition, dip coating, doctor blade, slot-die coating, film lamination and direct deposition from melt. [0020] Preferably, the step of applying the supporting layer on the thin film layer is by any one from selected group comprising: electrostatic transfer and processes involving applying pressure such as, rolling, laminating, hot-pressing or autoclave processing. [0021] Preferably, the step of removing the substrate is any one selected from the group comprising: chemical removal, electrostatic transfer and chemical delamination. [0022] Preferably, the steps (b) and (c) are repeated after step (e) to obtain multiple layers of thin films and graphene layers. [0023] Preferably, the method further comprising patterning the graphene and thin film layers. [0024] Preferably, the thin film layer is a polymer and is any one selected from the group comprising: polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF) and its copolymers (e.g. polyvinylidene fluoride-co-trifluoroethylene (P(VDF-TrFE)), poly(3-hexylthiophene) (P3HT) and polylactide (PLA). [0025] Preferably, the substrate is a metal substrate. More preferably, the metal substrate is copper. [0026] Preferably, the protector layer is a self-release layer. [0027] In another aspect of the present invention, there is provided a product comprising a graphene tape according to the first aspect of the invention. In a further aspect of the present invention, there is also provided a method of forming a product comprising applying the graphene tape according to the first aspect of the invention onto a surface of the product. [0028] This disclosure relates to the development of a graphene tape, in order to apply such material to any given target surface. This tape can solve existing issues that make it difficult for the large area application of graphene in different configurations. Applications of the graphene tape range from the application of a single layer of graphene or the application of semi- of fully operative graphene devices (in the case where the graphene layer has been pre-patterned during the fabrication of the graphene tape) onto a given surface for the fabrication of graphene containing electronic-like devices, to other lower end applications intended to quickly form electrical and thermal connections between two or more surfaces. [0029] The graphene tapes can be used for the large-area application of graphene on a surface. [0030] The tape is compatible with the application of graphene to substrates such as silicon wafers, glass, quartz, mica, polyethylene terephthalate (PET) or polyimide foils and paper, any other surface that has been prepared on such substrates or any other flat surface. The graphene tape may be used in applications such as the large scale fabrication of graphene devices, device encapsulation, composite materials applications based on graphene multi-stacks or for the transparent electrical and/or thermal interconnection of two surfaces. The tape may also be used in any other application where the properties of graphene and the non-sacrificial thin film layer are of interest for the experts in the field. [0031] The graphene tapes can boost mass production of products and applications based on graphene and/or other nanomaterials, and boost device fabrication strategies based on tape application methods versus the traditional layer-by-layer ones. [0032] Due to its exceptional mechanical, electronic, chemical, optical or thermal properties, among others, graphene has been coming under increasing interest for a wide range of applications, including electronic devices and energy storage applications. However, its industrial scale availability is generally as a powder, which form often does not lend itself to many applications. Graphene has been added to polymeric binders and other materials to form composites that be used for many applications, but the presence of the other components in the composites can adversely affect the electrical, chemical, or other desired properties of the material. It would thus be desirable to obtain a free-standing, mechanically stable graphene material containing little to no binder or other additives. [0033] Advantageously, a preferred embodiment of this invention does not refer to blends but to continuous, residue and defect free graphene films that result from its transfer together with a non-sacrificial thin film layer that, in addition to help to the transfer yield, the non-sacrificial thin film layer also adds value to the characteristics of the graphene film. The non-sacrificial thin film will mechanically and chemically protect the graphene layer while the fabrication and application of the tape. More importantly, it is to add functionality to the nanocomposite when stacked with the graphene. Because of this added functionality, the non-sacrificial thin film is not to be removed once the nanocomposite is applied, it is non-sacrificial, and, therefore, it will not cause mechanical damage and/or contaminate the graphene layer as when a sacrificial layer is used to transfer graphene. Hence, advantageously, the graphene material of the present invention is free of defects or residues. BRIEF DESCRIPTION OF THE FIGURES [0034] In order that the present invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative examples only preferred embodiments of the present invention, the description being with reference to the accompanying illustrative figures. [0035] In the Figures: [0036] FIG. 1 is a schematic diagram showing the graphene tape according to an embodiment of the present invention; [0037] FIGS. 2( a ) and ( b ) are schematic diagrams showing the graphene tape according to another embodiment of the present invention; [0038] FIGS. 3( a ) to ( e ) are schematic diagrams showing various structure configurations of the graphene/nanomaterial film according to an embodiment of the present invention; [0039] FIGS. 4( a ) to ( d ) are schematic diagrams showing patterning of the graphene/nanomaterial film according to an embodiment of the present invention; [0040] FIGS. 5( a ) to ( d ) are flow charts showing the fabrication of the graphene tape according to an embodiment of the present invention; [0041] FIG. 6 is an optical picture of a graphene tape according to an embodiment of the present invention; [0042] FIGS. 7( a ) and ( b ) are optical pictures of the nanocomposite film on (a) rigid and (b) flexible substrates after fabrication and application of the graphene tape according to two different embodiments of the current invention; and [0043] FIGS. 8( a ) and ( b ) are respectively, an optical picture of a graphene layer after application of a graphene tape according to one of the embodiments of the present invention and the statistical analysis on the continuity of the graphene layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0044] Structure of the Tape [0045] FIG. 1 shows a basic structure of the graphene tape according to any embodiment of the present invention. [0046] In its basic form, there is provided a graphene tape ( 10 ) having a support layer ( 11 ) and a nanocomposite layer ( 15 ) formed on the support layer ( 11 ). The nanocomposite layer ( 15 ) itself includes a thin film layer ( 6 ) and a graphene layer ( 8 ). From FIG. 1 , it can be seen that the thin film layer ( 6 ) is disposed between the support layer ( 11 ) and the graphene layer ( 8 ), i.e. it separates the support layer ( 11 ) and the graphene layer ( 8 ). The support layer ( 11 ) may be any support foil that provides the necessary mechanical support for the nanocomposite layer ( 15 ). [0047] Hereon and unless otherwise stated, the terms surface or device surface will both refer to the target surface the graphene tape is to be applied to. [0048] The present invention relates to the use of a graphene layer in the manufacture of a graphene tape. The graphene layer may be continuous, transparent and/or one atom thick. By “graphene layer”, it is meant a layer containing graphene. Graphene is a 2D sp2-hybridized carbon sheet with one-atom thickness that absorbs 2.3% of the in the optical spectrum. Because of its unique structure and special properties, graphene has attracted increasing attention in recent years. Its high theoretical surface area (2630 m 2 g −1 ), chemically stability and high electrical conductivity make it an attractive material for applications in nanoelectronics, optoelectronics, energy-storage systems and chemical sensors. [0049] Further, the term “graphene” includes any graphitic carbon material such as, but not limited to, single layer graphene and multilayer graphene (up to 100 layers) single-wall and multi-walled carbon nanotubes and their composites, including any modifications and/or functionalisations. Hereon and unless otherwise stated, graphene will also apply to any other 2D-like nanomaterial in any of their structures or arrangements, such as molybdenum disulphide or black phosphorus. [0050] By “thin film layer”, it is meant to include any structural material that may support the graphene layer and add functionality to the graphene. Examples of functionality include doping the graphene, protecting the graphene and providing biodegradable characteristics to the graphene. [0051] Further, in a preferred embodiment, the thin film layer ( 6 ) is non-sacrificial. As such, any reference made to the thin film layer of the present invention includes a reference to a non-sacrificial thin film layer. The non-sacrificial thin film layer results in an improved or added functionality of the graphene tape. By “non-sacrificial”, it is meant that the thin film is not a layer that is only to be deposited to assist in the fabrication and application of the graphene layer and is later to be removed, but that it is to remain together with the graphene layer after application of the tape, to a target surface. Partial post-patterning of the thin film, different from removal, may be required for post-patterning of a graphene device. As such, the nanocomposite layer ( 15 ) includes both a graphene layer ( 8 ) and a non-sacrificial thin film layer ( 6 ). The nanocomposite layer ( 15 ) may comprise graphene or functionalised or modified graphene attached to the non-sacrificial thin film layer. In an embodiment of the present invention, the non-sacrificial thin film layer may be a polymer. By “polymer”, it is meant to refer to any large molecule or macromolecule structure that is made up of many repeated subunits. Alternatively, the polymer layer may not be a polymer but any non-sacrificial thin film material that will give mechanical stability to the nanocomposite layer and that could result in providing attractive properties to the graphene layer. Examples of possible non-sacrificial thin films, but not limited to this list, are polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF) and its copolymers; poly(3-hexylthiophene) (P3HT) or polylactide (PLA). [0052] By “support layer”, it is meant the base film that supports or carries the nanocomposite film ( 15 ). The support layer ( 11 ) can be composed of materials such as, but no limited to, polyester, polyimide, vinyl, Polyethylene terephthalate (PET) or Teflon. [0053] The support layer ( 11 ) may have a protector layer ( 14 ) on its other exposed surface—the surface opposite to the nanocomposite layer ( 15 ). Likewise, the nanocomposite layer may also have a protector layer ( 13 ) on its other exposed surface—the surface opposite the support layer ( 11 ). In an embodiment of the invention, an adhesive layer ( 12 ) disposed between the support layer ( 11 ) and the nanocomposite layer ( 15 )—the polymer layer ( 6 ) is disposed between the adhesive layer ( 12 ) and the graphene layer ( 8 ). [0054] FIG. 1 is the most generic structure of the tape. It refers to a graphene tape having one graphene layer, for example a single layer graphene (SLG). In another embodiment of the invention, the graphene tape may comprise a multi-stacked nanocomposite layer ( 15 ). The nanocomposite layer ( 15 ) may have a plurality of non-sacrificial thin film layers ( 6 ), which are also known as polymer layers, and graphene layers ( 8 ). Within the nanocomposite layer ( 15 ), there could also be just one non-sacrificial thin film layer ( 6 ) and a plurality of graphene layers ( 8 ) stacked together. The only requirement is that there must be at least one non-sacrificial thin film layer ( 6 ) for separating the support layer ( 11 ) from the graphene layer ( 8 ). These will be described in detail below. [0055] FIG. 2( a ) shows a further example of the generic structure of a graphene tape having a graphene layer on one side of the tape. As in the graphene tape ( 10 ) shown in FIG. 1 , the graphene tape shown in FIG. 2( a ) is necessarily formed of a support foil ( 11 ) and a nanocomposite layer ( 15 ) which is made up of the non-sacrificial thin film layer and the graphene layer. The tape may include an adhesive layer ( 12 ) between the support foil and the nanocomposite layer ( 15 ). The tape may also include a self-release protector ( 13 ) to protect the nanocomposite layer ( 15 ) from degradation before the tape is applied to the target substrate. The tape could also include a self-release protector ( 14 ) to protect the support foil ( 11 ) during the fabrication of the tape and its application' to the target substrate. The support foil ( 11 ), the adhesive ( 12 ) and protection layer ( 14 ) may also collectively be referred to as the support layer. [0056] An example of the generic structure of a double-sided graphene tape is shown in FIG. 2( b ) . This tape includes a support layer/foil ( 11 ) and two nanocomposite layers ( 15 ). As can be seen in FIG. 2( b ) , the nanocomposite layers ( 15 ) are formed on opposite sides of the support layer ( 11 ). The tape may also be formed of the adhesive layers ( 12 ) and the protective self-release layers ( 13 ). [0057] The exact materials to form the support ( 11 , 12 , 14 ) and the nanocomposite layer ( 15 ) are to be chosen to match the requirements of the application the tape targets. For example, if the support is to delaminate from the nanocomposite layer ( 15 ) once the tape has been applied, these materials are to be chosen accordingly. For example, if the polymer ( 6 ) forming the nanocomposite layer ( 15 ) is to be an active layer of the final device, it will be chosen so that it will enhance and/or complement the characteristics of the graphene in the device application. [0058] Structure of the Nanocomposite Layer [0059] In every graphene tape configuration, the graphene layer ( 8 ) will always be separated from the support layer ( 11 ) by the non-sacrificial thin film layer ( 6 ). [0060] The most basic structure of the nanocomposite layer ( 15 ) is composed of a graphene layer ( 22 ) and a non-sacrificial thin film layer ( 21 ) as shown in FIG. 3( a ) . The nanocomposite layer ( 15 ) may also be fabricated to match other structures such as those shown in FIGS. 3( b ) to ( e ) . The following describes these various embodiments of the present invention. [0061] FIG. 3( b ) shows a nanocomposite layer ( 15 ) that may be composed of a non-sacrificial thin film layer ( 21 ), graphene layer ( 22 ) and non-sacrificial thin film layer ( 23 ) multi-stack. [0062] FIG. 3( c ) shows a nanocomposite layer ( 15 ) that is composed of multi-stack of non-sacrificial thin film layer ( 21 )/graphene layer ( 22 ) and a further non-sacrificial thin film layer ( 23 )/graphene layer ( 24 ). [0063] FIG. 3( d ) shows a nanocomposite layer ( 15 ) that is composed of a non-sacrificial thin film layer ( 21 ), and a stack of more than one graphene layers ( 25 , 26 ) in a multi-stack structure. [0064] In a further embodiment of the invention, which will be described in detail below, the graphene layer may be a matrix of graphene embedded in a non-sacrificial thin film layer, for example a polymer. The graphene/polymer matrix ( 8 ) is separated from the support layer ( 11 ) by the non-sacrificial thin film polymer layer ( 6 ). This is shown in FIG. 3( e ) . FIG. 3( e ) shows the most general nanocomposite layer ( 15 ) structure where the graphene layers ( 8 , 29 ) are embedded in a non-sacrificial thin film layer matrix ( 28 ), the only requirement being that the interaction with the support layer ( 11 ) is with an only non-sacrificial thin film layer ( 6 , 27 ). [0065] The key benefits of the graphene tape is related to the graphene in combination with the non-sacrificial thin film layer ( 6 ) (( 21 ) in the case of FIG. 3( a ) ) in between the support layer ( 11 ) and the graphene layer ( 8 ) (( 22 ) in the case of FIG. 3( a ) ). [0066] The structure of the nanocomposite layer ( 15 ) can be modified by prepatterning or etching of the nanocomposite layer prior to the layer stacking, and/or by deposition of motifs at any of the graphene layer or non-sacrificial thin film layer interfaces as shown in the schematics in FIG. 4 or any of their combinations. For example, these patterning can enable alignment of the nanocomposite layer with any level that had been previously patterned or that is to be patterned afterwards. Thus, the tape enables the direct printing of a graphene device component, even the print of full operative graphene devices. [0067] FIG. 4( a ) shows the patterning ( 31 ) of the graphene layer ( 22 ). FIG. 4( b ) shows patterning ( 31 ) of the non-sacrificial thin film layer ( 21 ). FIG. 4( c ) shows material deposition ( 32 ) on the external interface of the graphene layer ( 22 ). FIG. 4( d ) shows material deposition ( 32 ) at the graphene layer-non-sacrificial thin film layer interface ( 21 / 22 ). [0068] Fabrication of the Graphene Tape [0069] FIG. 5( a ) shows a possible cycle diagram for the fabrication of a graphene tape ( 10 ) according to an embodiment of the present invention to fabricate a graphene tape ( 10 ) having a nanocomposite layer ( 15 ) as shown in FIG. 2( a ) . FIG. 5( a ) results in a graphene tape ( 10 ) having the basic structure layer, in sequence: a support layer ( 11 ), a non-sacrificial thin film (polymer) layer ( 21 ), a graphene layer ( 22 ), and a protector layer ( 14 ). [0070] Optimal starting material is the substrate ( 42 ) where graphene has been grown or deposited on at least one of the surfaces. In an embodiment of the present invention, the substrate ( 42 ) may be a metal. More particularly, the substrate ( 42 ) may be copper. Other metal substrates such as nickel or platinum or any other substrate know by the people skilled in the art for the preparation of a graphene layer would also be compatible with the fabrication of the tape. The growing or formation of the graphene layer ( 22 ) on the metallic substrate ( 42 ) may be carried out by any technique known to the skilled person such as but, not limited to, thermal, rapid thermal or plasma chemical vapour deposition (CVD). In the case of thermal CVD and as an example on the preparation of the graphene layer of the present invention, a mixture of a hydrocarbon, such as methane or acetylene, and hydrogen can be used as the carbon source to grow one layer of graphene on a copper substrate at about 1000° C. The growth of the graphene may be achieved over any suitable size, for example lengths in the tens of centimetre range and beyond. If copper substrate was a copper foil, the area of the graphene would be limited to the surface of the foil. Alternatively, if the copper was a thin film that had been predeposited on a substrate such as a silicon-silicon oxide wafer, the area or the graphene will be limited to the area of the wafer covered with by copper. The graphene surface can be predefined by processes such as, but not limited to, defining a mask to the growth of graphene or by selectively removing the metal surface from the wafer prior to graphene growth, for a patterned growth of the graphene layer. Alternatively, the graphene may be patterned while on the substrate before depositing the thin film layer by processes such as but not limited to laser writing, oxygen or argon plasma etching or ozone etching. Alternatively, the graphene layer may be formed on the substrate after applying the graphene from a previous substrate by a methodology such as the methods described in the embodiments of this invention or by any other means known by the experts in the field. Graphene size will only be limited by the maximum allowed sample size at the graphene growth/deposition system. Alternative to the length of the graphene tape, graphene stacking strategies may be adopted to assure continuity of the graphene tape. [0071] Since the non-sacrificial thin film layer is to be deposited just after the formation of the graphene layer, there will not be any contamination. In some embodiments, cleaning steps are involved and these steps could include, but would not be limited to, solvent cleaning, plasma treatment and thermal annealing. [0072] The non-sacrificial thin film layer (polymer) ( 21 ) is then deposited or coated on top of the graphene layer ( 22 ) that is to form the tape. Techniques such as bar-coating or any other process resulting in the deposition of a thin polymer layer on a surface such as, but not limited to, spin coating, spray coating, polymer evaporation, Langmuir-Blodgett deposition, dip coating; doctor blade, slot-die coating, film lamination or direct deposition from melt, may be used to complete this step. Typically, the thickness of the non-sacrificial thin film layer ranges from 0.1 nanometers to 5 micrometers. Further post-processing of the non-sacrificial thin film layer such as, but not limited to, annealing for solvent evaporation, or to promote crystallization of the non-sacrificial thin film or other processes for the functionalization/modification of the non-sacrificial thin film such as, but not limited to, applying an electric field to align the dipoles in the case of a ferroelectric thin film, or to change the contact angle of the surface of the thin film layer may be considered to be part of the deposition of the non-sacrificial thin film on the graphene layer. [0073] Next is the application of the support layer ( 11 ) on top on the metallic substrate ( 42 ), graphene layer ( 22 ) and non-sacrificial thin film layer ( 21 ) stack by processes such as but not limited to electrostatic transfer and/or processes involving applying pressure such as, rolling, laminating, hot-pressing or autoclave processing. [0074] Delamination of the graphene tape from the substrate ( 42 ), for example, if copper was the substrate this step could be completed by processes such as, but not limited to, chemical etching in solutions of, for example, ammonium persulfate of iron chloride, by electrochemical delamination in solutions of, for example, ammonium persulfate or sodium chloride or by electrostatic transfer. [0075] The graphene layer could be released from other substrates too, for example SiO 2 . [0076] Finally, application of the protective self-release layer ( 14 ) and assembly of the graphene tape into a roll or into any other form of packaging in accordance with the final application of the tape is carried out. [0077] FIG. 5( b ) is a possible cycle diagram for the case where the nanocomposite layer is to be that shown in FIG. 3( b ) , a non-sacrificial thin film layer ( 21 )/graphene layer ( 22 )/non-sacrificial thin film layer ( 23 ) multi-stack film. In this case, after the tape is delaminated, a new non-sacrificial thin film layer ( 23 ) is deposited on the graphene layer ( 22 ). FIG. 5( b ) results in a graphene tape ( 10 ) having the basic structure layer, in sequence: a support layer ( 11 ), a non-sacrificial thin film layer ( 21 ), a graphene layer ( 22 ), a non-sacrificial thin film layer ( 23 ) and a protector layer ( 14 ). [0078] FIG. 5( c ) is a possible cycle diagram for the case where the nanocomposite layer is to be that shown in FIG. 3( c ) , a non-sacrificial thin film layer ( 21 ) and a graphene layer ( 22 ) multi-stack. In this case, after the tape is delaminated from the metal substrate (step (iv) in the previous description chart), the tape is applied again onto the metal substrate/graphene layer/non-sacrificial thin film layer stack after step (ii). This is to be repeated as many times as needed until the required multi-stacking is achieved. FIG. 5( c ) results in a graphene tape ( 10 ) having the basic structure layer, in sequence: a support layer ( 11 ), a non-sacrificial thin film layer ( 21 ), a graphene layer ( 22 ), a non-sacrificial thin film layer ( 23 ), a graphene layer ( 24 ) and a protector layer ( 14 ). [0079] FIG. 5( d ) is a possible cycle diagram for the case where the nanocomposite layer is to be that shown in FIG. 3( d ) —the non-sacrificial thin film layer ( 21 ) and a graphene layer multi-stack ( 25 , 26 ) nanocomposite layer. In this case, after the tape is delaminated (step (iv) in the previous description chart), the tape is applied again onto the starting material (i). This is to be repeated as many times as needed until the required multi-stacking is achieved. FIG. 5( d ) results in a graphene tape ( 10 ) having the basic structure layer, in sequence: a support layer ( 11 ), a non-sacrificial thin film layer ( 21 ), a graphene layer ( 25 ), a graphene layer ( 26 ) and a protector layer ( 14 ). In the present case, there are two stacks of graphene layers in the nanocomposite layer. [0080] The fabrication scheme of nanocomposite layer based on the structure in FIG. 3( e ) is similar to those in FIG. 5 . In this case, however, other processes will be applied for the fabrication of the non-sacrificial thin film and graphene composites and their multi-stacks. The graphene/polymer matrix may be prepared by any technique that is known to the skilled person. [0081] In the cases where the nanocomposite layer ( 15 ) is to be patterned as shown in FIG. 4 , processes such as, but not limited to contact printing or plasma etching, and screen printing, inkjet printing or spray coating could be used to etch and deposit motifs on the graphene layer interfaces, respectively. [0082] The above process schemes are just an example of the possible graphene tape production schemes. Any other methods known to the skilled person may be used, for example as an alternative combination of the above processes and structures, starting graphenes, non-sacrificial thin film layers deposition methodologies, support foils and adhesive application, and/or tape assembly strategies. [0083] The graphene tape technology can be applied to the production of tapes for the application of any nanomaterial film and for the application of any of their multi-stack based on their combinations. In addition, the polymer layer needs not be a polymer. Any non-sacrificial thin film material that will give mechanical stability to the nanomaterials and/or that could result in enhanced characteristics for a given application when multi-stacked with them, will also be of interest. FIG. 6 shows an optical picture of a one layer graphene tape that had been fabricated and then patterned according to an embodiment of the present invention described above. [0084] The growth of the graphene may be achieved over any suitable sample size, for example lengths in the tens of centimetre range and beyond. Graphene size will only be limited by the maximum allowed sample size at the graphene growth/deposition system. Alternative to the length of the graphene tape, graphene stacking strategies may be adopted to assure continuity. The fabrication of the tape as described in the embodiments of this invention is ideal for in-line production of the tapes. [0085] The graphene layer may be grown on the metallic substrate as described above. As an alternative, the graphene layer be grown separately and then formed on the support layer. The following provides an example of growing the graphene layer. [0086] Application of the Tape to a Target Surface [0087] The application of the graphene tape to a target substrate surface ( 30 ) will normally be based on the application of pressure and/or heat. The application may be seen in step (vi) in FIGS. 5( a ) to (d). Other application strategies such as, but not limited to, electrostatic transfer could also be implemented. Prior to the application of the tape the target surface may need to be cleaned to minimize the contaminants and hence, to promote a good binding. Pressure will aim at achieving a good binding of the nanocomposite layer to the destination surface. Heat will also aim at achieving a good binding between the nanocomposite layer and the substrate, but also, it could be the mechanism to delaminate the support from the nanocomposite layer ( 15 ). No residues from the support are to be left on the nanocomposite layer after delamination. The present invention may use any thermal release adhesive tape to achieve application. [0088] Depending on the target application the tape could be applied by, but not limited to, finger pressure, with a roll, with an office laminator, by heating at a certain temperature or by industrial methods such as, roll-to-roll or hot-press at temperatures between 50° C. and 150° C. [0089] The graphene tape of the present invention may be applied to surfaces with roughness in the micrometer range and to surfaces where features had been pre-patterned. The present graphene tape has been shown to result in a good transfer to substrates that are considered by a skilled person to be rough, such as PET foils and paper. FIGS. 7( a ) and ( b ) shows examples of nanocomposites after the application of graphene tapes onto a silicon-silicon oxide wafer (as shown in FIG. 7( a ) ) and a PET foil (as shown in FIG. 7( b ) ) according to the embodiments of the present invention. In (a) the graphene layer had been prepatterned by selectively removing part of the graphene layer and by defining metallic motifs at the graphene layer/non-sacrificial thin film layer interface according to the embodiments of the present invention. The device in (b) is an example of a non-sacrificial thin film layer and a graphene multi-layer stack that had been pre-patterned to define motifs on each of the graphene layers that were used for their alignment according to various embodiments of the present invention. [0090] Post-Application Usage [0091] Once the graphene has been applied to the surface, there may be post-application modification processes applied to either the non-sacrificial thin film polymer layer or to the graphene layer. These may include but are not limited to electrical polarization or annealing. Such processes may assist in improving properties of the deposited nanocomposite layer such as the electrical, mechanical or optical properties. For example, if the graphene layer is a single graphene layer and the non-sacrificial thin film layer is P(VDF-TrFE)), the dipoles forming the P(VDF-TrFE) film could be aligned by applying an electric field across the P(VDF-TrFE) film and this alignment could result in doping on the graphene layer that may improve the conducting characteristics of the nanocomposite layer. [0092] Once the tape has been applied and any post-application are completed, the applied nanocomposite layer will be fully functional. If the applied material is to be part of a device, it could be that extra fabrication steps such as but not limited to patterning the nanocomposite or defining electrical contacts will be needed to complete the device fabrication. [0093] Conclusion [0094] The graphene tape of the present invention overcomes the existing issues for the application of graphene to a target surface, that is, the residues and the mechanical damage occurring from the use of sacrificial transfer layers. The tape enables the application of individual single layer graphene (SLG), graphene multi-stacks and graphene-polymer heterostructures. The graphene being applied may be continuous, (for example, the graphene coverage will be equal or above 90% of the surface) and residue free at the interfaces (residues on the graphene from the tape will cover less than 10% of the graphene surface). As an example of the tape application, FIG. 8 is (a) an optical image of a graphene layer resulting from the application of a graphene tape according to the embodiments of the invention and (b) is the statistical evaluation of the continuity of such film. [0095] There are no defects introduced to the graphene (graphene can be applied with a 90% yield in coverage with respect to the graphene coverage on the initial graphene substrate the tape is made of) because i non-sacrificial thin film layer that is different from the tape support mechanically protects the graphene during the fabrication of the tape and during its application to the target surface. Resulting from the low level of defects, inline fabrication yield of devices based on the tape will be maximized. [0096] In the tape configuration as shown in FIG. 3( d ) and in the embodiments in FIG. 5( d ) where only one graphene layer ( 26 ) is applied onto the target surface ( 30 ), the graphene layer ( 26 ) will not come into contact with any non-sacrificial thin film polymer layer before it is applied to the substrate surface (except for any areas where the interlayer graphene ( 25 ) may not cover the non-sacrificial thin film ( 21 )). Thus, the interfaces of the applied graphene will be free of residues (except for those areas resulting from the contact with the non-sacrificial thin film layer ( 21 ) through defect on the top graphene layer ( 25 )). This transfer/application results in a contamination-free transfer of the bottom graphene layer ( 26 ). [0097] In the tape configuration where a non-sacrificial thin film layer and graphene layer multi-stack is to be applied onto the surface (as can be seen in the graphene tape configurations shown in FIGS. 3( a ) to ( c ) ), there will not be residues from the transfer thin film layer at the graphene interface (below 5% coverage of polymer residues over the full graphene surface) because the polymer forming the tape will become an active layer of the device and, thus, it will not be a residue and will not need to be removed. The non-sacrificial thin film layer forming the tape may be selected such that it will contribute to the properties and characteristics of the nanocomposite film (for example electrical and mechanical properties). For example, if P(VDF-TrFE)) is used, it can act as the dielectric layer in transistor or memory like applications, or as the graphene doping material in graphene based electrode applications. [0098] The fabrication of the graphene tape is compatible with a roll-to-roll production process and non-expensive materials are only needed for its manufacture. Therefore, the graphene tape is compatible with large scale production. [0099] The graphene tape enables the large area, position controlled and residue free application of graphene to a flat target surface. This means that the tape is compatible with layer-by-layer fabrication methods and can be applied to any flat surface. Since the tape application is not solution-based, the interface between the graphene and the surface can be controlled so that it is residue free. Also, since the graphene will not become in contact with any material during the fabrication but with the non-sacrificial thin film layer, that is not to be removed and is to contribute to the functionality of the graphene nanocomposite, and with the materials used in the fabrication of the tape as described above, the interfaces of the graphene will be free from residues from polymers or other materials that are used as the transfer layer in other state of the art graphene transfer processes. [0100] The tape also enables the large area, position controlled and residue free application of complex graphene-non-sacrificial thin film and graphene-graphene heterostructures, stacks or ply laminates with clean interfaces to a flat surface. This tape enables the mass production of graphene heterostructures and novel composite materials. Since the composition of the layers to form the nanocomposite layer can be selected, these composites can be tuned to show unique properties for a determined application. Since the non-sacrificial thin film layer is to be directly deposited on graphene (and not a result of any prior processing as may be carried out by existing fabrication processes), this interface will be free of residues and protected from contamination and mechanical damage. Again, the tape is compatible with layer-by-layer fabrication methods and can be applied to any flat surface. Since the tape application is not solution based, the interface between the graphene and the surface can be controlled so that it is residue free. The interfaces having no residues, the interaction between the graphene layer and the non-sacrificial thin film layer is optimal. [0101] The graphene tape also enables the direct printing of functional graphene based component or even full graphene based devices on a given surface. As such, the device area will only depend on tape fabrication. The patterning of the tape enables level alignment in layer by layer fabrication of device—etching of the non-sacrificial thin film polymer layer and graphene enables graphene patterning. Further, material deposition enables the patterning of structures such as contacts. As example, single layer graphene could be coated with a thin layer of P(VDF-TrFE) and then patterned to form touch sensors, and these touch-sensors could be later printed on the glass covers or the LCD screens of touch-screen like applications. [0102] The graphene tape also enables the application of an electrically and thermally conductive, transparent coating over any surface, or between any contacts. Graphene being transparent and electrically and thermally conductive results in the graphene tape being a transparent, current and heat conductor. Surfaces may be flexible or rigid, and the deposited graphene film will bend accordingly. [0103] In addition to the above, the main difference of the graphene tape, and what confers its advantage over other methods, is that the non-sacrificial thin film polymer layer in between the support/adhesive layers ( 11 , 12 ) is the key to the application of the tape. The non-sacrificial thin film polymer layer does not only work as a transfer layer for mechanical stability of the graphene. It is because of the non-sacrificial thin film polymer layer that the tape can result in the application of a residue free graphene or in residue free graphene/polymer interfaces. Resulting from this, the interaction of the graphene and the polymer is improved with respect to the case where a sacrificial layer is used in the application of graphene. [0104] This results in the interfaces on the graphene or multi-stacks are residue free, thus the interfaces are better quality than after previous methods, thus, device operation is to be improved when using the graphene tape. [0105] Also, there is no need for extra processing steps to remove any non-sacrificial thin film polymer layer or any adhesive residues. As a result, the application of the graphene or multi-stack becomes simpler and cheaper since less material and residues are to be used and to be generated during the application process. [0106] The tape can boost the coating of surfaces with SGL, SGL multi-stacks and other 2D, 1D and 0D nanomaterials. The graphene tape could be used in, but would not be limited to, quite a number of applications. [0107] For example, it may be used in electronics. The tape is fully compatible with roll-to-roll processing, thus it is compatible with the processing of flexible and also wafer based electronics. Since its easy application, it could have high impact at both a research and an applications level. In another example, the applied graphene may be used for the fabrication of graphene based integrated circuits. The graphene tape may be used in the application of non-sacrificial thin film layer/graphene stacks, for example, a P(VDF-TrFE)/graphene stack could be used for the fabrication of low sheet resistance electrodes for touch screen applications (i.e ITO replacement). The graphene tape simplifies the processing steps and results in more continuous graphene layers (less mechanically defective) and less contaminated (less residues) that improves the device fabrication yield and the device characteristics. For example, in the case of thin film conductors, the graphene tape in the case of a P(VDF-TrFE) non-sacrificial thin film layer would result in improved conductivity with respect to its counterpart processed with a sacrifitial layer and later coated with P(VDF-TrFE). [0108] Patterned graphene tapes may be used for the direct printing of graphene based device components or full devices. For example, a graphene pattern could be applied to form electrical interconnects or a heat dissipation element component. For example, a single layer graphene may be coated with a thin layer of P(VDF-TrFE) and then patterned to form touch sensors, and these touch-sensors may be later printed on the glass covers or the LCD screens of touch-screen like applications. [0109] The mechanical stability of the graphene resulting from its combination with the non-sacrificial thin film enables the application of a single layer of graphene or multi-stacks of single layer graphene to non-conventional substrates, such as paper. Thus, the fabrication of graphene devices based on SGL or their multi-stack on paper. [0110] The graphene tape of the present invention may be used in making composite devices. [0111] The graphene multi-stacks may be used for the fabrication of membrane-like devices, for example, for the fabrication of micro- or nanomechanical actuators. The non-sacrificial thin film layer gives mechanical stability to the graphene. Graphene would become mechanically damaged if a sacrificial layer would be used. [0112] The graphene multi-stacks can also be used to fabricate of composites with improved mechanical properties. For example, graphene stacks could substitute glass and/or carbon fibers and improve the mechanical properties of such structures. [0113] The multi-stacks could also be used for distributing electricity or for heat conduction and/or dissipation. As such, it can be used as a conductive wire or for a uniform spreading of heat in cooking applications. Moving further, the graphene tape may also be used for making or repairing electrical contacts either at a small scale i.e. on integrated chips, a medium scale i.e. for household repair jobs or for large scale i.e. heat exchanger and boiler coatings for enhanced thermal efficiency. [0114] The graphene tape may also be used for encapsulation because graphene is hydrophobic, it blocks water, it is highly electrically and thermally conductive and because it is transparent in visible wavelengths (one layer of graphene only absorbs 2.3%) and even higher transparency for doped graphene in the infrared. It could also be used for electromagnetic shielding. For example, the graphene tape could be used to encapsulate paper documents or paper money with a continuous SLG graphene. This encapsulation would prevent the paper documents from being changed and it would minimize the degradation of the paper since it would prevent from moisture, water and any other contaminants. Since the graphene tape is compatible with the pre-patterning of nanostructures, additional marks and/or shields could also be added to the tape to improve the security of the encapsulation. Following the embodiments of the invention graphene tape can be used to encapsulate other nanomaterials and/or to produce tapes of other nanomaterials, as previously defined, with an encapsulation, for example black phosphorus, to prevent them from degradation when being exposed to oxygen or water environments. [0115] Whilst there has been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.

The invention relates to a graphene tape. In particular, it relates to the manufacture, the application and possible uses of such a graphene tape. A graphene tape comprising (a) a support layer; and (b) a first nano-composite layer, the nanocomposite layer comprising a thin film layer and a graphene layer, wherein the thin film layer is disposed between the support layer and the graphene layer. A method of manufacture comprising (a) providing a substrate; (b) forming a graphene layer on the substrate; (c) depositing a thin film layer on the graphene layer; (d) applying a supporting layer on the thin film layer; (e) removing the substrate; and (f) applying a protective layer in place of the substrate.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/647,586, filed May 16, 2012, entitled METHOD FOR SYNTHESIZING SELF-ASSEMBLING NANOPARTICLES, incorporated herein by reference. FIELD [0002] Embodiments disclosed herein relate to a method for synthesizing self-assembling nanoparticles with defined plasmon resonances. More particularly, certain embodiments disclosed herein relate to an improved method for synthesizing self-assembling gold/gold sulfide nanoparticles by dialyzing samples during the self-assembly process. BACKGROUND [0003] U.S. application Ser. Nos. 12/807,792 and 12/807,793 (the “'792 and '793 applications”), incorporated herein by reference in their entireties, disclose gold/gold sulfide (“GGS”) nanoparticles within a chitosan matrix, and methods for synthesizing and using the same. These references disclose forming GGS nanoparticles by self-assembly of a sulfide source, such as sodium thiosulfate, and a gold source, such as cholorauric acid. GGS nanoparticles have absorbance peaks in the near infra-red (“NIR”) region, which are tunable by varying the self-assembly conditions. During self-assembly of GGS nanoparticles, gold colloid is simultaneously formed as a byproduct. In the '792 and '793 applications, gold colloid particles were removed using one, or more commonly three, rounds of centrifugation. SUMMARY [0004] Embodiments disclosed herein relate to a method for synthesizing self-assembling nanoparticles. More particularly, certain embodiments disclosed herein relate to an improved method for synthesizing self-assembling GGS nanoparticles by dialyzing samples during the self-assembly process. In some embodiments, the method for synthesizing GGS nanoparticles disclosed herein provides a higher ratio of GGS nanoparticles to gold colloid as compared to the method cited in the '792 and '793 applications. [0005] In some embodiments, the present invention pertains to a method for making hybrid nanoparticles, including combining a gold source and a sulfide source in a first chamber, the first chamber being separated from a second chamber by a semipermeable membrane, wherein the gold source and sulfide source self-assemble into hybrid nanoparticles. In further embodiments, the hybrid nanoparticles comprise gold and gold sulfide. [0006] In further embodiments, the gold source is a gold salt, such as, for example, chloroauric acid, sodium tetrachloroaureate(III) dehydrate, or a mixture thereof. In certain embodiments, the sulfide source is a sulfide salt, such as, for example, sodium thiosulfate, sodium sulfide, or a mixture thereof. [0007] In certain embodiments, the combining occurs at room temperature. In some embodiments, the nanoparticles have an absorbance peak between 700 nm and 1100 nm. [0008] In further embodiments, the nanoparticles have a tunable absorbance peak. In some embodiments, the method includes tuning the absorbance peak by adjusting the ratio of gold source and sulfide source. In further embodiments, the semipermeable membrane has a molecular weight cut off (“MWCO”) and the method includes tuning the absorbance peak by selecting the MWCO of the semipermeable membrane. In certain embodiments, the MWCO is between about 2 KDa and about 20 KDa, between about 2 KDa and about 12 KDa, or about 12 KDa. In some embodiments, the semipermeable membrane has a surface area, the gold source and sulfide source have a combined volume, and the method includes tuning the absorbance peak by adjusting a ratio of the surface area to the combined volume. In certain embodiments, the ratio of the surface area to the combined volume is between about 220 mm 2 /mL and about 470 mm 2 /mL. In further embodiments, the gold source and sulfide source in the first chamber are dialyzed against a dialysate in the second chamber for a period of time, and further comprising tuning the absorbance peak by adjusting the period of time. In certain embodiments, the method includes tuning the absorbance peak by adjusting the temperature. [0009] In some embodiments, the nanoparticles have a quality ratio greater than 1.8, greater than 2.0, or greater than 2.3, without centrifugation of the nanoparticles. [0010] In some embodiments, the present invention pertains to a method for making a hybrid nanoparticle including adding a first chemical species to a first chamber, and adding a second chemical species to a second chamber, the first chamber being separated from a second chamber by a semipermeable membrane having a MWCO, wherein the first chemical species and second chemical species self-assemble into hybrid nanoparticles. In further embodiments, the first chemical species is a gold source and the second chemical species is a sulfide source. [0011] In some embodiments, the present invention pertains to a method for self-assembly of hybrid nanoparticles including separating a first chamber from a second chamber using a semipermeable membrane, adding a gold source and a sulfide source to the first chamber, and adding water to the second chamber, whereby production of GGS nanoparticles is greater in the first chamber than in the second chamber, and production of gold colloid is greater in the second chamber than in the first chamber. [0012] This summary is provided to introduce a selection of the concepts that are described in further detail in the detailed description and drawings contained herein. This summary is not intended to identify any primary or essential features of the claimed subject matter. Each embodiment described herein is not intended to address every object described herein, and each embodiment does not necessarily include each feature described. Other forms, embodiments, objects, advantages, benefits, features, and aspects of the present invention will become apparent to one of skill in the art from the detailed description and drawings contained herein. BRIEF DESCRIPTION OF THE DRAWINGS [0013] A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings, wherein: [0014] FIG. 1 is a TEM image of a sample including GGS nanoparticles and gold colloid; [0015] FIG. 2 is a TEM image of a sample including GGS nanoparticles; [0016] FIG. 3 is a spectral scan of samples from Example 1; [0017] FIG. 4 is a spectral scan of samples from Example 2; [0018] FIGS. 5A-5B are spectral scans of samples from Example 3; [0019] FIG. 6 is a spectral scan of samples from Example 4; [0020] FIG. 7 is a spectral scan of samples from Example 5; [0021] FIGS. 8A-8C are spectral scans of samples from Example 6; [0022] FIG. 9 is a spectral scan of samples from Example 7; [0023] FIG. 10 is a spectral scan of samples from Example 8; [0024] FIGS. 11A-11B are spectral scans of samples from Example 9; [0025] FIG. 12 is a spectral scan of samples from Example 10; and [0026] FIGS. 13A-B are a spectral scans of samples from Example 11. FIG. 13C is a chart showing the relationship between peak wavelength and initial ratio (defined in Example 11 below). FIG. 13D is a chart showing the relationship between quality ratio and initial ratio. [0027] FIG. 14 is a spectral scan of samples from Example 12. [0028] FIG. 15 is a graph comparing NIR peak wavelengths at different temperatures for samples from Example 13 at different SA/Vol. ratios. [0029] FIG. 16 is a spectral scan of samples from Example 14. [0030] FIG. 17 is a graph comparing NIR peak wavelengths at different temperatures for samples from Example 15 at different SA/Vol. ratios. [0031] FIG. 18 is a spectral scan of samples from Example 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0032] For purposes of promoting an understanding of the principles of the invention, reference will now be made to one or more selected embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates. One embodiment of the invention is shown in great detail, although it will be apparent to those skilled in the relevant art that some features or some combinations of features may not be shown for the sake of clarity. [0033] GGS nanoparticles are preferably created by the self-assembly of a sulfide source and a gold source. In some embodiments, the sulfide source is a sulfide salt. In certain embodiments, the sulfide source is sodium thiosulfate (Na 2 S 2 O 3 ), sodium sulfide (Na 2 S), or other suitable sulfur-containing chemical or mixture of chemicals. In some embodiments, the gold source is a gold salt. In some embodiments, the gold source is chloroauric acid (HAuCl 4 ), sodium tetrachloroaurate(III) dehydrate (NaAuCl 4 ), or other suitable gold-containing chemical or mixture of chemicals. The absorbance peak of GGS nanoparticles can be controlled by (1) adjusting the ratio of sodium thiolsulfate and chloroauric acid solutions used to create the GGS nanoparticles, (2) adjusting the concentration of sodium thiolsulfate and chloroauric acid, (3) adjusting the temperature, (4) adjusting the physical state of the gold and sulfide solutions through (a) agitation, (b), premixing the solutions prior to dialysis, or (c) a combination of (a) and (b), (5) adjusting the molecular weight cut off of the semipermeable membrane used in dialysis or as a reaction vessel, (6) adjusting the dialysate used for the dialysis reaction, and (7) adjusting the ratio of surface area of the semipermeable membrane to the volume of the combined gold and sulfide sources within the membrane. Using manufacturing methods disclosed herein, stable GGS nanoparticles may be produced with absorbance peaks between about 700 nm and about 1100 nm. In certain embodiments, where the GGS nanoparticles are intended to be excited by a laser, the nanoparticles are selectively manufactured to have an absorbance peak substantially identical to the wavelength of the laser to maximize energy absorption. [0034] Referring now to FIG. 1 , gold colloid is a byproduct of GGS nanoparticle self-assembly. Gold colloid has an absorbance peak at 530+/−20 nm. FIG. 1 shows a sample of GGS nanoparticles with contaminating gold colloid produced by the single step assembly method disclosed in the '792 and '793 applications, prior to any separation steps. In the methods disclosed in the '792 and '793 applications, GGS nanoparticles are separated from gold colloid by centrifugation. An example separation process is centrifugation at 1000 g for 20 minutes. Additional centrifugation steps may be used to increase purity. While effective in separating gold colloid from GGS nanoparticles, centrifugation decreases the GGS nanoparticle yield. [0035] Referring now to FIG. 2 , a sample of GGS nanoparticles produced by the disclosed method is shown. Substantially no gold colloid is visible in the image. As shown, GGS nanoparticles are formed in a several shapes, including rods, generally triangular plates, and generally spherical bodies. The term “GGS nanoparticles” is not shape specific and includes particles of particular shapes and mixtures of shapes. The shape of individual GGS nanoparticles within a sample affects the overall absorbance spectrum of the sample. Rod-shaped particles, when oriented on end, provide an absorbance peak at about 530 nm. Therefore, even when substantially all gold colloid is removed from a sample, a measure of absorbance at about 530 nm may still be present. Analysis has shown that the disclosed method produces a nanoparticle shape distribution of 78%±3% spherical, 20%±3% generally triangular plates, and 2%±1% other shapes, including rods. [0036] In some embodiments, a sample contains a gold source and a sulfide source which self-assemble into GGS nanoparticles and gold colloid. The sample is placed in a semipermeable membrane configured to exclude based on size, sometimes referred to as a dialysis membrane, and dialyzed against deionized (“DI”) water or other dialysate during the self-assembly process. In certain embodiments, the gold source and sulfide source are blended in a bag-shaped dialysis membrane. In other embodiments, the gold source and sulfide source are blended together for a specific length of time then transferred into a bag-shaped dialysis membrane which serves as a reaction vessel. In certain embodiments, the gold source and sulfide source are blended in a first chamber, the first chamber being separate from a second chamber by a dialysis membrane. In certain embodiments, the second chamber may be a re-circulating or purged flow water bath. In certain embodiments, the first chamber may be a flow-through dialysis cell. In some embodiments, the gold source and sulfide source are dialyzed against water. In further embodiments, the gold source is dialyzed against the sulfide source. In some embodiments, the sulfide source is dialyzed against the gold source. In certain embodiments, the gold source and sulfide source are combined and dialyzed against a dialysate, such as, for example, water, a salt solution, a glycerol solution, or sodium citrate. In one embodiment, the salt solution is a sodium chloride solution. [0037] As shown in the examples below, variation in the dialysis time, the molecular weight cut off (“MWCO”) of the dialysis membrane, and the ratio of gold source to sulfide source modifies the quality ratio of the resulting product and the wavelength of the absorbance peak. Without being bound by theory, it is hypothesized that dialysis performed during the self-assembly process forces ion-exchange across the membrane, providing a change in reaction kinetics. This hypothesized change in kinetics results in a shift in the equilibrium of the self-assembly reaction which favors GGS nanoparticle production within the dialysis membrane and gold colloid production outside the membrane. [0038] A “quality ratio” is the ratio of the absorbance of synthesized particles in the near infrared (“NIR”) region (700 nm to 1100 nm, for the purposes of this calculation), which corresponds to absorbance characteristics of GGS nanoparticles, relative to absorbance at 530+/−20 nm, which corresponds to the absorbance characteristics of gold colloid. Early GGS synthesis methods provided quality ratios in the range of 0.4-0.8 prior to any separation steps, such as centrifugation. The one-step synthesis method disclosed in the '792 and '793 applications provided quality ratios in the range of 0.7-1.0, then about 1.7-2.0 after centrifugation. The method disclosed herein has provided quality ratios above 1.8, above 2.0, and above 2.3, without centrifugation, indicating a significantly higher yield of GGS nanoparticles. [0039] The examples herein disclose the use of semipermeable membranes to improve the yield of self-assembled GGS nanoparticles. However, semipermeable membranes may be used to improve the yield of other self-assembling nanoparticles as well. In further embodiments, a first chemical species and a second chemical species are blended in a first chamber, the first chamber being separated from a second chamber by a dialysis membrane, wherein the first chemical species and the second chemical species self-assemble into a nanoparticle. In certain embodiments, the first chemical species is a gold source and the second chemical species is a sulfide source. [0040] In some embodiments, the first chamber is a dialysis membrane shaped to form a bag and the second chamber is a liquid-filled beaker, vial, vat, tank, bucket, or other container in which the first chamber is placed. In other embodiments, the first and second chambers are subsections of a larger chamber, the subsections being separated by a semipermeable membrane. In other embodiments, a first chemical species may be dialyzed against the second chemical species to form self-assembling nanoparticles. In these embodiments, a first chemical species is added into a first chamber and a second chemical species is added into a second chamber, the first chamber and second chamber being separated by a semipermeable membrane. [0041] The following examples are provided to illustrate certain specific features of working embodiments and general protocols. The scope of the present invention is not limited to those features exemplified by the following examples. Spectral scans disclosed in the examples were obtained using a UV/Vis spectrophotometer (Carey 50 Varian), and all disclosed wavelengths are in nanometer units. Nanometer-scale images were obtained using a tunneling electron microscope (“TEM”) (200 kV FEI Tecnai F20). EXAMPLE 1 [0042] Fill a 1 L beaker with 800 mL of DI water and include a stir bar. Add a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in a 3500 Molecular Weight Cut Off (“MWCO”) dialysis membrane and insert in the beaker for 1 hour (sample 1). In this example, the interior of the dialysis membrane serves as the first chamber and the beaker serves as the second chamber. For a non-dialysis control sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 2). Fill a second 1 L beaker with 3 mM Na 2 S 2 O 3 . Add 25 mL of 2 mM HAuCl 4 in a 3500 MWCO dialysis membrane to the second beaker and let it react for 1 hour (sample 3). [0043] Spectral scans of the samples are shown in FIG. 3 . Sample 1 has a peak at attributable to gold colloid and a strong, distinct peak in the NIR range attributable to GGS nanoparticles. Sample 2 has a peak attributable to gold colloid and strong absorbance NIR range and extending into longer wavelengths. Sample 3 has a peak absorbance at about 530 nm and no peak in the 700-900 nm range, indicating the formation only of gold colloid. EXAMPLE 2 [0044] Fill a 1 L beaker with 800 mL of DI water and include a stir bar. Add a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane to the beaker for 1 hour (sample 1). For a non-dialysis sample (sample 2), 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour. Separately, fill two 1 L beakers with 3 mM Na 2 S 2 O 3 . To each beaker, add 25 mL of 2 mM HAuCl 4 in a 3500 MWCO dialysis membrane and let them react for 2.5 and 5 hours, respectively (samples 3 and 4). [0045] Spectral scans of the samples are shown in FIG. 4 . As shown, samples 3 and 4 have negligible GGS nanoparticle formation. EXAMPLE 3 [0046] Fill four 1 L beakers with 800 mL of DI water and stir bar. Place a mixture of 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane into two beakers for 1 and 2 hours, respectively (samples 2 and 3 of FIG. 5A ). Place a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane into two beakers for 1 and 2 hours (samples 2 and 3 of FIG. 5B ). For a non-dialysis sample (sample 1 of FIGS. 5A and 5B ), 11 mL of 2 mM HAuCl 4 and 2 or 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hr. [0047] Spectral scans of the samples are shown in FIGS. 5A and 5B . As shown, the sample of 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 dialyzed in a 3500 MWCO dialysis membrane produces the largest peak shift in the NIR range. EXAMPLE 4 [0048] Fill two 1 L beakers with 800 mL of DI water and stir bar. Maintain a water temperature of about 100° C. Add a mixture of 11 mL of 2 mM HAuCl 4 and 3 of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane for a 5 minute soak (sample 1). Add a mixture of 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane for a 15 minute soak (sample 2). [0049] As shown in FIG. 6 , neither sample produced a peak in the NIR range. EXAMPLE 5 [0050] Fill an 8 L bucket with DI water and stir bar. In a 1-step method, a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane is added for 1 hour (sample 2). Next for a 2-step method, 4 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are reacted for 30 seconds in a 50 mL tube, then added into a 3500 MWCO dialysis membrane with an additional 7 mL of 2 mM HAuCl 4 to react for an hour (sample 3). For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 1). [0051] Spectral scans of the samples are shown in FIG. 7 . As shown, the two step method of mixing the gold source and sulfide source shortly before insertion into the dialysis membrane resulted in a higher quality ratio, but a lower peak shift, than the one step method disclosed in the '792 and '793 applications. EXAMPLE 6 [0052] Fill an 8 L bucket with DI water and stir bar. Combine samples of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in 3.5 KDa and 12 KDa MWCO dialysis membranes, and allow each to react for an hour (samples 2 and 3 of FIG. 8A ). For a 2-step method, react samples of 4 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 for 30 seconds, then add 7 mL of 2 mM HAuCl 4 and place in 3.5 and 12 KDa MWCO dialysis membranes to allow further reaction for an hour (samples 2 and 3 of FIG. 8B ). For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 1 of FIGS. 8A , 8 B and 8 C). Additionally, the following controls were also synthesized: 2-step, react samples of 4 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 for 30 seconds, then add 7 mL of 2 mM HAuCl 4 and allow to react for 1 hour (sample 2 of FIG. 8C ); 1-step dialysis as above using a 12 KDa MWCO dialysis membrane (sample 3 of FIG. 8C ); and 2-step dialysis as above using a 12 KDa MWCO dialysis membrane (sample 4 of FIG. 8C ). [0053] Spectral scans of the samples are shown in FIGS. 8A-8C . In both the 1-step process and 2-step process, dialysis provides a greatly increased quality ratio as compared to the non-dialysis sample, as shown by the relatively small gold colloid peaks. For the 1-step process, FIG. 8A shows that using the 3.5 KDa MWCO dialysis membrane results in a greater peak shift and a higher quality ratio than the 12 KDa MWCO dialysis membrane. In contrast, FIG. 8B shows that using a 3500 MWCO dialysis membrane results in the NIR absorbance peak shifting to a higher wavelength than the non-dialysis sample for the 2-step process. FIG. 8C shows that the two step process, used without dialysis, does not produce a significant fraction of NIR GGS nanoparticles. EXAMPLE 7 [0054] Fill two 1 L beakers with 800 mL of DI water and stir bar. Maintain a water temperature of 65° C. in one of the beakers, while the other is left at room temperature (RT). Add a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in a 3500 MWCO dialysis membrane to the RT beaker (sample 2) and the 65° C. beaker (sample 3), each for 1 hour. For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 1). [0055] Spectral scans of the samples are shown in FIG. 9 . As shown, the yield of GGS nanoparticles, as evidenced by the NIR peak, was significantly greater at RT than at the elevated temperature. EXAMPLE 8 [0056] Fill an 8 L bucket with DI water and stir bar. Add a mixture of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in 2 KDa and 3 KDa MWCO dialysis membranes for 1 hour (samples 2 and 3). For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 1). [0057] Spectral scans of the samples are shown in FIG. 10 . As shown, use of the 3.5 KDa MWCO dialysis membrane provides a significantly larger NIR peak shifts than the 2 KDa MWCO membrane. The following Table 1 is a summary of the absorbance peaks and quality ratios for each sample. [0000] TABLE 1 Summary of Sample Properties in Example 8 Samples NIR Absorbance Peak (nm) Quality Ratio Sample 1/No dialysis 928 1.473 Sample 2/2 KDa MWCO 881 1.378 Sample 3/3.5 MWCO 765 1.513 EXAMPLE 9 [0058] Fill an 8 L bucket with DI water and stir bar. Add mixtures of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in three separate 3.5 KDa MWCO dialysis membranes for 1, 2, and 4 hour, respectively (samples 2, 3, and 4 of FIG. 11A ). Fill a separate 8 L bucket with DI water and stir bar. Add mixtures of 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 in three separate 2 KDa MWCO dialysis membranes for 1, 2, and 4 hours, respectively (samples 2, 3, and 4 of FIG. 11B ). For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 3 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour (sample 1 of FIGS. 11A and 11B ). Spectral scans of the samples are shown in FIGS. 11A and 11B . [0059] The following Table 2 is a summary of the absorbance peaks, extinction coefficients, and quality ratios of each sample. For the non-dialyzed “No Dia” control samples, the column “Dialysis Time” simply indicates the delay between mixing the gold and sulfide sources and acquiring the spectral data. [0000] TABLE 2 Summary of Sample Properties in Example 9 Dialysis NIR Colloid NIR Time Absorbance Extinction Extinction Quality Samples (hours) Peak (nm) Coeff. Coeff. Ratio No Dia 1 959 0.766 1.179 1.539 (sample 1, FIGS. 11A and 11B)   2K Dia 1 899 0.605 0.821 1.357 (sample 2, FIG. 11B)   2K Dia 2 926 0.632 0.895 1.416 (sample 3, FIG. 11B)   2K Dia 4 930 0.616 0.889 1.444 (sample 4, FIG. 11B) 3.5K Dia 1 816 0.599 0.916 1.527 (sample 2, FIG. 11A) 3.5K Dia 2 815 0.622 1.007 1.620 (sample 3, FIG. 11A) 3.5K Dia 4 819 0.615 0.967 1.573 (sample 4, FIG. 11A) EXAMPLE 10 [0060] Fill an 8 L bucket with DI water and stir bar. Add mixtures of 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 in three separate 3.5 KDa MWCO dialysis membranes for 1, 2, and 4 hour, respectively. Also, add mixtures of 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 in three separate 2 KDa MWCO dialysis membranes for 1, 2, and 4 hours. For a non-dialysis sample, 11 mL of 2 mM HAuCl 4 and 2 mL of 3 mM Na 2 S 2 O 3 are mixed in a 50 mL tube and reacted for 1 hour. [0061] Spectral scans of the samples are shown in FIG. 12 . As shown, dialysis using 3.5 KDa MWCO dialysis membranes produced significant peak shifts. Dialysis using 2 KDa MWCO dialysis membranes did not result in distinct peaks in the NIR range. EXAMPLE 11 [0062] Fill an 8 L bucket with DI water and stir bar. Add mixtures of 11 mL of 2 mM HAuCl 4 and 2.5, 3, 3.5, 4, 4.5, or 5 mL of 3 mM Na 2 S 2 O 3 in 50 mL tubes, or 2 KDa or 3.5 KDa MWCO dialysis membranes for 1 hour. The following Table 3 is a summary of the samples, their initial ratios, NIR peaks, and quality ratios. An “Initial ratio” is the ratio of the volume of gold source to the volume of sulfide source in a given sample, the concentrations of the gold source and sulfide source remaining constant between compared samples. For example, 11 mL of 2 mM HAuCl 4 and 2.5 mL of 3 mM Na 2 S 2 O 3 provides an initial ratio of 11/2.5=4.40. Non-dialyzed samples are identified herein as “RT” or room temperature, although all samples were maintained at room temperature throughout the experiment. [0000] TABLE 3 Summary of Sample Properties in Example 11 Sample NIR Dialysis (vol. gold source + Absorbance Quality Method vol. sulfide source) Initial Ratio Peak (nm) Ratio RT 11 + 2.5 4.40 none N/A RT 11 + 3 3.67 995 1.675 RT 11 + 3.5 3.14 901 1.398 RT 11 + 4 2.75 852 1.126 RT 11 + 4.5 2.44 807 0.895 RT 11 + 5 2.20 779 0.730   2 KDa 11 + 2.5 4.40 931 1.588   2 KDa 11 + 3 3.67 928 1.421   2 KDa 11 + 3.5 3.14 950 1.436   2 KDa 11 + 4 2.75 848 1.209   2 KDa 11 + 4.5 2.44 771 0.783   2 KDa 11 + 5 2.20 771 0.787 3.5 KDa 11 + 2.5 4.40 789 1.804 3.5 KDa 11 + 3 3.67 816 1.731 3.5 KDa 11 + 3.5 3.14 820 1.621 3.5 KDa 11 + 4 2.75 834 1.352 3.5 KDa 11 + 4.5 2.44 789 1.038 3.5 KDa 11 + 5 2.20 747 0.787 [0063] Spectral scans of selected samples from Table 3 are shown in FIGS. 13A and 13B . More specifically, FIG. 13A includes spectral scans of samples dialyzed in 2 KDa MWCO dialysis membranes and FIG. 13B includes spectral scans of samples dialyzed in 3.5 KDa MWCO dialysis membranes. FIG. 13C depicts the correlation between NIR peak wavelength and initial ratio. FIG. 13D depicts the correlation between quality ratio and initial ratio. Note that in several places in FIGS. 13C and 13D , a diamond symbol identifying a non-dialyzed sample is not visible as it is covered by a square symbol identifying a sample dialyzed in a 2 KDa MWCO dialysis membrane. FIG. 13C indicates that decreasing initial ratios generally correlate with NIR absorbance peaks at lower wavelengths. As shown in FIG. 13D , increasing initial ratios generally correlate with increasing quality ratios. EXAMPLE 12 [0064] For this experiment, molar concentration of reagents and temperature was kept constant while surface area to volume ratio of 12 KDa MWCO dialysis tubing (flat width 43 mm) was adjusted. Varying lengths of dialysis tubing were used to show the effect of surface area of the semipermeable membrane to volume of nanoparticle solution. For example, a dialysis tubing of length 100 mm and width 43 mm has a surface area (for both sides of the tubing) of 8600 mm 2 which, when divided by a solution volume of 40 mL, provides a SA/Vol. ratio of 215 mm 2 /ml. 32.6 mL of 2 mM HAuCl 4 was poured into the dialysis tube with one end clipped. 7.4 mL of 3 mM Na 2 S 2 O 3 was then added in via pipette to the solution, providing a combined solution volume of 40 mL. All air was removed from the dialysis tubing and the open end of the tubing was clipped. The membrane was then placed inside an oven set at 100° C. To increase the membrane surface-to-air interaction, the dialysis membranes were placed on top of plastic pipette tip holders. A sample was recorded every 5 minutes to determine the when the reaction equilibrium point is reached. Table 1 below shows the nIR peak position. [0000] TABLE 4 Effect of membrane surface area to sample volume on NIR peak Dialysis Tubing Length (mm) 100 130 175 220 SA/Vol. (mm 2 /mL) 215 280 377 473 Time (min) Wavelength (nm) 5 1080 1089 946 843 10 985 873 753 743 15 929 797 756 733 20 831 803 752 730 25 832 787 751 728 [0065] The reaction reached equilibrium after 20 minutes for the 100 mm tubing, 15 minutes for the 130 mm tubing, 10 minutes for the 175 mm tubing, and 10 minutes for the 220 mm tubing. FIG. 14 depicts spectral scans of the nanoparticle solutions at different SA/Vol. ratios, with each depicted sample being the equilibrium sample listed above. As indicated, modification of the SA/Vol. ratio affects the NIR peak of the self-assembling nanoparticles and affects the reaction time to reach equilibrium. For the purposes of this experiment, a reaction is considered to have reached equilibrium when the absorbance peak shifts no more than 5 nm in a 15 minute period. EXAMPLE 13 [0066] For this experiment, molar concentration of reagents was kept constant while surface area to volume ratio, MWCO of the dialysis tubing, and temperature were adjusted. Varying lengths of dialysis tubing were used to show the effect of modifying the SA/Vol. ratio, as described in Example 12. 32.6 mL of 2 mM HAuCl 4 was poured into the dialysis tube with one end clipped. 7.4 mL of 3 mM Na 2 S 2 O 3 was then added in via pipette to the solution. All air was removed from the dialysis tubing and the open end of the tubing was clipped. The membrane was then placed inside an oven set at various temperatures: 100° C., 50° C., and 25° C. To increase the membrane surface-to-air interaction, the dialysis membranes were placed on top of plastic pipette tip holders. A sample was recorded every 10 minutes to determine the when the reaction equilibrium point is reached. Three trials were performed for each set of conditions including the 12 KDa MWCO dialysis tubing while two trials were performed for each set of conditions including the 10 KDa MWCO dialysis tubing. FIG. 15 is a graph plotting the NIR peak detected at different temperatures as the MWCO of the dialysis tubing and the SA/Vol. ratio varies. As shown, dialysis in the 12 KDa MWCO dialysis tubing result in GGS nanoparticle with a lower NIR peak wavelength at a given temperature and SA/Vol. ratio than does dialysis in the 10 KDa MWCO dialysis tubing. Also, higher temperatures result in lower NIR peak wavelengths at given MWCO and SA/Vol. values. EXAMPLE 14 [0067] For this experiment, molar concentration of reagents was kept constant while surface area to volume ratio, MWCO of the dialysis tubing, and temperature were adjusted. Two lengths of dialysis tubing were used to show the effect of modifying the SA/Vol. ratio, as described in Example 12. 32.6 mL of 2 mM HAuCl 4 was poured into the 12 KDA MWCO dialysis tube with one end clipped. 7.4 mL of 3 mM Na 2 S 2 O 3 was then added in via pipette to the solution. All air was removed from the dialysis tubing and the open end of the tubing was clipped. The membrane was then placed inside a 2 L beaker filled with DI water with a stir bar on a low setting. Two different water temperatures were used to show the effect of temperature on the reaction: 50 and 25° C. A sample was recorded every 10 minutes to determine the when the reaction equilibrium point is reached. Three trials were performed for each set of conditions. [0068] FIG. 16 depicts spectral scans of the nanoparticle solutions at different SA/Vol. ratios and temperatures, with each depicted sample being taken from the time point after reaction equilibrium was reached. As shown in the air-exposed samples in Example 13, the samples dialyzed against water in this example also provided lower NIR peak wavelengths when exposed to higher temperatures. Higher SA/Vol. ratios resulted in lower NIR peak wavelengths at a given temperature. EXAMPLE 15 [0069] For this experiment, molar concentration of reagents was kept constant while surface area to volume ratio, MWCO of the dialysis tubing, and temperature were adjusted. Three lengths of dialysis tubing, 100 mm, 150 mm, and 200 mm, were used to show the effect of modifying the SA/Vol. ratio, as described in Example 12. 32.6 mL of 2 mM HAuCl 4 was poured into the 12 KDA MWCO dialysis tube with one end clipped. 7.4 mL of 3 mM Na 2 S 2 O 3 was then added in via pipette to the solution. All air was removed from the dialysis tubing and the open end of the tubing was clipped. The membrane was then placed inside a 2 L beaker filled with DI water with a stir bar on a low setting. Two different water temperatures were used to show the effect of temperature on the reaction: 50° C., 37° C., and 25° C. A sample was recorded every 10 minutes to determine the when the reaction equilibrium point is reached. Three trials were performed for each set of conditions. [0070] FIG. 17 depicts spectral scans of the nanoparticle solutions at different SA/Vol. ratios and temperatures, with each depicted sample being taken from the time point after reaction equilibrium was reached. As shown in the air-exposed samples in Example 13 and the water-exposed samples in Example 14, the samples in this example also provided lower NIR peak wavelengths when exposed to higher temperatures. At a given temperature, nanoparticles produced from dialysis with SA/Vol. ratios of 340 mm 2 /mL and 470 mm 2 /mL resulted in had lower NIR peak wavelengths than nanoparticles produced from dialysis with a SA/Vol. ratio of 220 mm 2 /mL. EXAMPLE 16 [0071] This experiment was designed to compare synthesis of GGS nanoparticles using different dialysis membranes against synthesis without dialysis. Fill four 8 L buckets with 7.5-8 L of DI water and place a stir bar inside each. Next, prepare and add 4 mixtures of 11 mL 2 mM HAuCl 4 (added to the dialysis bag first) and 2.5 mL 3 mM Na 2 S 2 O 3 (added to the dialysis bag second) to 2 KDa MWCO, 3.5 KDa MWCO, 6-8 KDa MWCO, and 12 KDa MWCO bag-shaped dialysis membranes separately, and let the samples dialyze for one hour. Then, for a non-dialysis sample, 11 mL 2 mM HAuCl 4 and 2.5 mL 3 mM Na 2 S 2 O 3 is mixed in a 50 mL tube and reacted for one hour. Spectral scans are obtained for each sample after an hour of self-assembly synthesis at room temperature using a UV/Vis spectrophotometer (Carey 50 Varian). The spectral scans are shown in FIG. 17 , and the detected NIR wavelength peaks and calculated quality ratios are listed in Table 4 below. [0000] TABLE 4 Effect of dialysis membrane MWCO on NIR peak NIR Wavelength Peak Sample (nm) Quality Ratio No Dialysis 1098 2.58   2 KDa MWCO 858 1.35 3.5 KDa MWCO 748 1.54 6-8 KDa MWCO 744 1.57  12 KDa MWCO 799 1.65 [0072] As shown in FIG. 17 , dialysis using the 12 KDa MWCO dialysis membrane provided the highest quality ratio for samples with NIR peaks in the preferred 700-900 nm range. This was an unexpected result, as the relatively larger pores in the 12 KDa membrane would be less effective at preventing HAuCl 4 , Na 2 S 2 O 3 , and resulting nanoparticles from escaping the interior of the bag-shaped membrane as compared to membranes with smaller pores. EXAMPLE 17 [0073] This experiment was designed to compare the yield of synthesis of GGS nanoparticles using a dialysis membrane against non-dialysis synthesis including separation by centrifugation. For the dialysis sample, HAuCl 4 and Na 2 S 2 O 3 was added to a 12 KDa MWCO bag-shaped dialysis membrane, and allowed to dialyze for one hour. Then, for a non-dialysis sample, equal amounts of HAuCl 4 and Na 2 S 2 O 3 is mixed in a tube and reacted for one hour. As made, the dialysis method produced a 55 mL nanoparticle solution with an OD of 7.5. The non-dialysis method produced a 55 mL nanoparticle solution with an OD of 2.5. After three rounds of centrifugation, the non-dialysis solution was concentrated to a 0.34 mL solution at an OD of 117. The final quality ratios of the methods were generally equal (2.36 dialysis/2.38 non-dialysis), but the yield from the dialysis method was approximately 10 fold higher (412.5 dialysis/39.8 non-dialysis). [0074] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications can be made by those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention.

Embodiments disclosed herein relate to a method for synthesizing self-assembling nanoparticles with defined plasmon resonances. More particularly, certain embodiments disclosed herein relate to an improved method for synthesizing self-assembling gold/gold sulfide nanoparticles by dialyzing samples during the self-assembly process.

BACKGROUND OF THE INVENTION [0001] I. Field of the Invention [0002] This invention relates generally to equipment for compacting waste material, and more particularly to the design of a trash compactor for use in fast food restaurants and other food vending establishments where the patron is expected to deposit his/her waste paper products in a trash receptacle upon leaving the establishment. [0003] II. Discussion of the Prior Art [0004] Many fast food restaurants and cafeterias typically provide a refuse or waste container near the exit doors of the establishment and at other convenient locations so that at the conclusion of a meal, the patron's tray containing napkins, paper cups, food wrappers, placemats, etc. can be dumped into the waste receptacle by the patron rather than by restaurant staff. However, it is up to the restaurant staff to periodically empty these trash receptacles, bag the waste materials in polyethylene bags and then deposit the bagged waste in a dumpster for pick-up by a refuse removal service. [0005] Because the waste material is merely allowed to fall by gravity in the conventional waste receptacles currently used, it is not particularly dense and frequent emptying of the waste receptacles by staff personnel is required to prevent overflow and attendant lack of patron compliance. The need to frequently empty the refuse receptacles can be a significant cost item for a restaurant operation. Moreover, since refuse haulers generally charge by volume and not by weight, bagged, loosely-compacted refuse takes up an inordinate amount of space in a dumpster and also adds to the cost of refuse disposal. [0006] A need, therefore, exists for a refuse compactor capable of compressing fast food restaurant trash so that less frequent emptying is required and a greater mass of waste material can be contained in a smaller volume. The present invention provides a unique solution to this problem. SUMMARY OF THE INVENTION [0007] In accordance with the present invention, there is provided a refuse compactor especially designed for use in a restaurant facility that comprises a frame having a horizontal, rectangular base and a pair of upwardly extending structural members affixed to the base along opposed side edges thereof. Extending across the structural members at the top thereof is a horizontal cross member. Further supported by the frame is a compaction plate assembly that includes a one-piece platen pivotally affixed to a support member for rotation about a horizontal axis, a hydraulic ram that is operatively disposed between the horizontal cross member of the frame and the support member for driving the compaction plate in a vertical direction toward and away from the base and a pair of guide rods for maintaining alignment of the assembly during its operational stroke. Biasing springs are disposed between the support member and the platen for urging the platen from a first position that is inclined to the vertical to a second horizontal position during a downward movement of the compaction plate assembly when the hydraulic ram is actuated. On a return stroke of the compaction plate assembly, the platen is returned to its inclined position. [0008] The refuse compactor has decorative sidewalls mounted in surrounding relation to the frame and includes a door at a front thereof which can be opened to withdraw a wheeled cart containing compacted trash. Formed through the door is a refuse receiving opening and mounted relative to the opening is a hinge panel that is pivotable about a horizontal axis for selectively blocking the refuse-receiving opening. In that the compaction plate is inclined to the vertical when its raised disposition, it does not interfere with the opening of the hinged panel by a patron wishing to deposit refuse into the compactor. Means are provided for automatically swinging the hinged panel to its open position upon detection of the approach of a patron toward the compactor. DESCRIPTION OF THE DRAWINGS [0009] The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts. [0010] FIG. 1 is an isometric view of the trash compactor comprising a preferred embodiment of the present invention; [0011] FIG. 2 is an isometric view from the front and right side of the trash compactor of FIG. 1 , but with the decorative outer skins removed to show the internal construction; [0012] FIG. 3 is an isometric view like that of FIG. 2 , but taken from the rear and right side; [0013] FIG. 4 is an isometric view of the frame structure for the embodiment of FIG. 1 ; [0014] FIG. 5 is an exploded view of the preferred embodiment of FIG. 1 ; [0015] FIG. 6 is a perspective view of the compactor plate assembly used in the embodiment of FIG. 1 ; [0016] FIG. 7 is a detailed view of the door motion arm that is attached to the waste entry door; [0017] FIG. 8 is an alternative embodiment of a compaction plate drive assembly; and [0018] FIG. 9 is a partial view of the compaction assembly of FIG. 8 showing the drive mechanism. DESCRIPTION OF THE PREFERRED EMBODIMENT [0019] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the device and associated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof and words of similar import. [0020] Shown in FIG. 1 is an isometric view of a trash compactor specifically designed for use in fast food restaurants. It is indicated generally by number 10 . In this figure, decorative plastic skins 11 form an enclosure having a pair of sidewalls joined to one another by a rear wall that are in place on the machine. A door 13 forms a front of the enclosure. It has an opening 15 through which restaurant waste or the like can be deposited, the waste is adapted to fall into a polyethylene refuse bag (not shown) used to line the box 156 of a removable cart assembly 17 when the door 13 is closed and locked. A removable plastic top panel 19 is attached that has upwardly projecting ribs adjacent the side and rear perimeters of the top panel. The space between these ribs provides a convenient place for serving trays to be stacked once the waste has been deposited into the cart 17 through the opening 15 . [0021] During use, the door 13 will be closed and locked. The door is only open to remove the cart 17 once it is filled with compacted waste material. A motor-operated hinged panel 23 normally blocks the opening 15 , but swings to an open position when a proximity sensor detects the approach of a patron. an audio message is also played. The manner in which this is accomplished will be explained in considerably more detail as the description of the preferred embodiment continues. [0022] Referring then to FIG. 2 , there is shown a front isometric view of a waste compactor constructed in accordance with the present invention, it is indicated generally by numeral 10 and, for clarity, the outer skins 11 are removed to better illustrate the machine's internal parts. The framework for the compactor includes a flat, generally rectangular steel base 12 that is mounted on four caster wheels, as at 14 , to facilitate moving and positioning of the compactor. Welded to the upper surface 16 of the base 12 midway along its opposed sides are upwardly extending structural members here shown as vertically oriented steel channels 18 and 20 . These heavy gauge steel channels are further supported by triangular steel gussets 22 that are welded both to the top surface 16 of the base 12 and to the respective vertical channels 18 and 20 . Extending between the upper ends of the vertical channels 18 and 20 is a horizontal cross member, here shown as a steel top channel 24 that is also welded in place. [0023] As can be seen in FIG. 3 , there is welded to the rear edges of the vertical channels 18 and 20 proximate the upper end thereof a steel tray on which is supported an electronic control board assembly 28 . Electrical power is delivered to the compactor 10 by way of a power cord 30 that is adapted to plug into a connector 32 on the rear of the tray 26 . [0024] Disposed below the tray 26 and also welded to the vertical channels 18 and 20 is a support plate 34 on which is mounted an electric motor 36 that is coupled in driving relation to a hydraulic pump 38 . [0025] Referring to the isometric view of the frame assembly shown in FIG. 4 , also welded to the vertical channels 18 and 20 at a location proximate the upper ends thereof is a steel tray 40 . It has a vertical rear wall 42 affixed to front edge surfaces of the channels 18 and 20 and a vertical front wall 44 . The rear and front walls are connected by a horizontal, forwardly projecting floor plate 46 . To add additional rigidity to the steel tray 40 , a steel plate 48 located approximately midway across the width dimension of the steel tray 40 is welded to the rear plate 42 , the front plate 44 and the floor plate 46 . [0026] Welded to the rear plate 42 and to the channel 20 at its upper end is a steel arm 50 that passes through a notch 52 formed in the front wall 44 . Secured to the arm 50 is a door hinge pin 54 , as shown in FIG. 2 . A further door hinge pin 56 is affixed to the front edge of the base 12 by a forwardly projecting ear 58 . The hinge pins 54 and 56 are vertically aligned with one another, allowing the door 13 to be suspended thereon. The door 13 as well as the skins 11 are preferably fabricated from fiberglass. [0027] The frame structure shown in FIG. 4 also includes a triangular bracket 60 that is welded to the vertical channel 18 and projects forwardly to support a box-like housing 62 in which a door lock assembly is to be contained. [0028] Referring momentarily to the exploded view of FIG. 5 , there is indicated generally by numeral 64 a compaction plate assembly. It includes a cast aluminum plate or platen 66 that is pivotally mounted to a steel channel support member 68 . The pivot connection includes a pair of compactor plate bearings 70 , disposed midway along the side edges of the compaction plate 66 , through which a cylindrical pin 72 extends to allow rotation of the platen 66 about a horizontal axis. A pair of strong, helical springs 74 are mounted on the pivot pin 72 . They are operatively disposed between the channel support member 68 and the compaction plate 66 so as to apply a biasing force thereto tending to rotate the compaction plate 66 so that it becomes parallel to the top surface of the channel support member 68 , i.e., horizontal, during a compaction stroke, all as will be further described. [0029] With continued reference to the compaction plate assembly 64 of FIG. 5 , affixed to the top surface of the channel support member 68 is a hydraulic ram 76 . It is centrally disposed between a pair of guide rods 78 and 80 . Guide sleeves, as at 82 , fit into openings formed through the support tray 34 from which the compaction plate assembly 64 is suspended and serve as bearings for the guide rods 78 and 80 . The ram attaches to the top channel 24 and is vertically oriented such that when pressurized by hydraulic fluid from the pump 38 causes the compaction plate to execute a compaction stroke whereby trash deposited in the cart 17 is crushed and compressed. [0030] To avoid having trash deposited on the top surface of the compaction plate 66 , it is imperative that the compaction plate be inclined as shown in FIGS. 2 and 3 as waste is being deposited through the door opening 15 . However, in order to effect compaction, the plate must assume a horizontal disposition during its downward compaction stroke and return to its inclined disposition at the end of the compaction stroke. To achieve this result, there is provided a relatively large diameter roller 84 that is suspended from a tube 86 of rectangular cross section that is welded to the undersurface of the support plate 34 . The roller 84 is journaled for rotation in a U-shaped bracket 88 having a rectangular tube 90 welded to it. The rectangular tube 90 is dimensioned to telescopingly fit within the tubular bracket 86 and held in place by setscrews whereby the degree of extension can be adjusted. [0031] Also attached to the top surface of the compaction plate is a compactor plate pin assembly 92 . It is used to releasably lock the platen in a horizontal position during the downward stroke of the platform. As shown in the detailed view of FIG. 6 , the compactor plate pin assembly comprises a rectangular block-like housing 94 having laterally extending flanges 96 and 98 with bolt apertures 100 extending through it to permit attachment to the compaction plate. The block 94 includes a bore 102 formed longitudinally therethrough and into which is fitted a locking pin 104 that is provided with a gear rack on an undersurface thereof (not shown). Cooperating with the gear rack on the locking pin 104 is a pinion (not shown) that rotates with an L-shaped lever 106 that is journaled in the housing 94 . Rotation of the lever therefore causes reciprocal movement of the pin 104 in the bore 102 . The lever 106 is positioned relative to the roller 84 so that as the compaction plate descends from the disposition shown in FIGS. 2 and 3 , the pin 104 will be made to project out through the bore 102 at the inner edge of the block 94 to overlay the top surface of the channel 68 , thereby locking the compaction plate 66 in its horizontal disposition during the downward movement of the compaction plate assembly, assuring that any objects that may be in the trash being compacted cannot tilt the compaction plate away from its desired horizontal disposition. [0032] Upon the return stroke, as the compaction plate assembly again rises, a point is reached where the roller 84 again engages the L-shaped lever 106 to thereby move the locking pin 104 to the right when viewed in FIG. 6 whereby the engagement of its far end with the upper surface of the channel 68 no longer pertains. Thus, the continued engagement between the roller 84 and the compaction plate 66 can return the compaction plate to its tilted disposition shown in FIG. 2 against the force of the springs 74 . [0033] Returning again to the exploded view of FIG. 5 , the hinge panel 23 comprising the waste entry door 23 is pivotally mounted to a pair of door hinge arms 108 and 110 which fasten by screws to the floor plate 46 ( FIG. 4 ) of the steel tray 40 . Fastened to the inside surface of the hinge panel 23 is a door motion arm 112 that has an arcuate cam profile 114 formed therein along its length dimension. Also mounted on the floor plate 46 of the tray 40 is a door actuating motor 116 which is coupled through a gear box 118 to one end of an arm 120 supporting a cam follower roller 122 on the free end thereof. The arm 120 is joined to an output shaft of the gear box 118 , as is a further cam (not shown). This further cam cooperates with Microswitches® 124 and 126 which are connected in circuit with the motor 116 to cause the arm 120 to be rotated 180° upon each actuation of the motor. [0034] The roller 122 is positioned to cooperate with the arcuate surface 114 on the arm 112 so as the arm moves through 180°, the waste entry door swings open to the position shown in FIGS. 2 and 3 , allowing waste to be dumped into the cart 17 . Because the platform of the compaction plate assembly is inclined, it does not interfere with the opening of the hinged panel waste entry door 23 . [0035] The actuation of the motor 116 is controlled by a commercially available motion sensor 128 that mounts to a bracket 130 on an upper rear surface of the main entry door 13 . Thus, when the door 13 is closed and locked, as a patron approaches the waste compactor 10 , the motion is detected and a signal is sent to the motor 116 to initiate a 180° swing of arm 120 to first open the waste entry door 23 . As the patron moves away after depositing refuse into the compactor, the action is again sensed and the motor 116 is triggered to rotate the arm an additional 180°, allowing the waste entry door 23 to reclose. To prevent the door 23 from bouncing upon closure thereof, a permanent magnet 129 is mounted on the tray 46 ( FIG. 4 ) that attracts a ferrous metal disk 131 that is suspended by a threaded rod from an appendage on the arm 112 as shown in FIG. 7 . [0036] A programmable logic array comprising the electronic circuit 28 is configured to initiate a compaction cycle after a predetermined number of openings of the waste entry door 23 . For example, and without limitation, the electronic circuit may be programmed such that 10 patrons approaching and depositing refuse into the cart 17 will initiate a compaction cycle whereby that refuse is compressed into a cube defined by the side walls of the cart 17 . [0037] To prevent the waste entry door 23 from opening during the compaction cycle, which might expose a patron to injury, an interlock is provided to block the waste entry door 23 from opening during a compaction cycle. Specifically, a solenoid 132 is mounted on a rear surface of the rear end plate 42 of the steel tray 40 with the solenoid plunger 134 extending through a hole drilled in that plate. When the solenoid is energized, the plunger 134 extends in a forward direction to overlay and interfere with a stop bracket 136 that is affixed to swing arm 112 to which the waste entry door 23 attaches. The pin on the solenoid thus blocks the waste entry door 23 from being swung open so long as the solenoid 132 is energized. At the completion of the compaction stroke and return of the compaction plate to its elevated and tilted disposition, the solenoid is deenergized, retracting the pin 134 , thus allowing swinging movement of the waste entry door under control of the motor assembly 116 . [0038] The door lock for securing the door 13 preferably comprises a socket head bolt 138 that is designed to pass through a sleeve 140 that is mounted in the door 13 . The bolt 138 is sufficiently long to project through the thickness dimension of the door 13 and into a threaded block 142 designed to fit within the triangular bracket 60 . The block 142 is urged forward within the confines of the box-like housing 62 by a helical spring 144 . Using an Allen wrench, the bolt 138 may be rotated to draw the door 13 against the vertical edge 146 of the inner wall 148 disposed in the frame and preventing the door 13 from being opened by persons not having an appropriate Allen wrench. [0039] To prevent actuation of the compaction plate assembly if the door 13 is open, a magnetic proximity switch of a well-known type has its switch contact member 148 fastened to the front wall 44 of the steel tray 40 at a position where it will be actuated when a magnet 150 that is affixed to the inside surface of the main door panel 13 is brought into close proximity to it. Thus, only when the door is closed will the switch contacts of the magnetic switch 148 be closed to permit the motor 36 driving the hydraulic pump to run. [0040] The cart 17 includes a base tray 152 mounted on wheels 154 and supported on the base tray is a separable trash-receiving chamber 156 . The chamber 156 has four mutually perpendicular sidewalls, an open top and an open bottom. For convenience, a polyethylene bag may be inserted into the chamber 156 for ultimately containing the trash once impacted. A pull handle 158 is pivotally attached to the base 152 to facilitate removing a filled and compacted mass of waste material through the open door 13 and to a temporary storage site. Once at the storage site, the tube-defining chamber 156 can be lifted free of the tray 152 , leaving a compacted trash-filled bag for ultimate disposal by a trash hauling company. [0041] It has also been found desirable to mount an audible speaker 160 to the front wall 44 of the steel tray 40 where the speaker is coupled by wires to a voice chip integrated circuit on the electronics panel 28 . As in many telephone answering machines, these voice chips may be used to store several short audio messages that are played each time a patron causes the waste entry door 23 to swing open as a marketing tool. The messages may thank the patron for visiting the restaurant or for dumping his/her trash, etc. [0042] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself. For example, satisfactory performance has been achieved when the hydraulic ram 76 has been eliminated, along with its associated hydraulic pump and associated hydraulic lines, and replaced with a mechanical drive. As shown in FIG. 8 the cylindrical guide rods 78 and 80 seen in FIG. 6 have been replaced by elongated bars 162 and 164 and the rectangular bars have a gear rack 166 formed longitudinally there along. An electric motor 168 ( FIG. 9 ) is affixed to the support tray 34 and its output shaft is coupled through a gearbox 170 to an output shaft 172 on which pinion gears 174 and 176 are keyed. Upon command from the devices' programmable logical ray to initiate a compaction stroke, the motor 168 is energized, thereby driving the pinion gears 174 and 176 on the rack surfaces 166 of the guide rods 162 and 164 to cause the compaction plate to descend and later ascend. The compaction plate assembly of FIGS. 8 and 9 is otherwise identical to that of FIG. 6 whereby the locking of the compaction plate in a horizontal disposition and a subsequent release thereof to allow it to assume and inclined disposition is the same as has already been explained.

A refuse compactor especially designed for use in fast-food restaurant environments includes a hydraulic pump driven by an electric motor for actuating a hydraulic ram to compress restaurant waste materials. The compactor includes a unique compaction plate assembly that maintains the platen inclined at a predetermined angle to the vertical when the platen is elevated and which forces the platen to a horizontal disposition during a downward compaction stroke. A motor operated closure member selectively blocks and unblocks a refuse-receiving opening formed in a front door of the compactor unit and with a motion detector controlling the opening and closing of the refuse entry door panel.

FIELD OF THE INVENTION This invention relates to the field of data transmission, and in particular to such a system for recombining at a receiver plural slow data rate odd and even data signals derived from an input signal, into an output signal at the input signal data rate, without regard to the sense of the odd and even data signals applied to the receiver. BACKGROUND TO THE INVENTION In digital communications systems, the physical and electrical characteristics of the transmission facility normally limits the maximum rate at which data can be transmitted, the maximum transmission distance, the noise susceptibility and the emissions that cause radio frequency interference (RFI). To overcome this limitation, common practice is to reduce the data symbol rate (the baud rate), to a lower frequency by generating codes with multiple levels, multiple phases, or both. This multilevel, multiphase coding can be very expensive to design and manufacture and can consume a great deal of power, particularly at high speeds. This can prevent its use in cost sensitive applications, such as in computer local area networks. An alternative technique that reduces the cost and power consumption is to use multiple pairs of wires to reduce the data rate on each pair, thus allowing for an increase in transmission distance for the same performance, and a reduction in RFI. In many installations, users have extra pairs of wires installed, and are willing to use them to reduce the cost of the communications equipment. Recent proposals for 100 megabit Ethernet networks include using multiple wiring pairs to reduce the bit rate on each pair, to allow transmissions over common in-office twisted pair wiring without violating the U.S. Federal Communication Commission's RFI emissions guidelines and to provide reliable data transport. Such systems are restricted to particular data protocols specifically designed to accommodate the data rate, and thus cannot carry any or all data streams which use any protocol. SUMMARY OF THE INVENTION The present invention provides for distribution of signals over plural (such as two) pairs of wires, but can transparently carry conventional data transmission protocols, instead of being restricted to a special protocol to accommodate the data rate. Any transmission protocol which uses regularly repeating adjacent multi-bit framing patterns can be used. One example of such a protocol is the SONET (Synchronous Optical Network) protocol. By using existing communications protocols, hardware costs are minimized, no software is required, and complete data transparency is assured. An embodiment of the present invention also allows the installer to connect either of the wiring pairs to either input of the receiver, without regard to which pair is connected to which input. Pair select circuitry automatically determines which of the data streams contains the even and which the odd framing bits, and places them in correct order in the resulting output signal from the receiver. This simplifies the wiring installation by making the proper connections of the wiring pairs to the equipment less important, and it simplifies the design of the transmitter, which can arbitrarily choose even and odd assignment without knowledge of frame boundaries. In accordance with an embodiment of the invention, a transmission system is comprised of apparatus for receiving an input data stream with repeating, adjacent multi-bit framing patterns and a synchronous clock at a first data rate and a first clock rate, apparatus for dividing the input data stream into a pair of data streams and clock streams each at half the bit rate of the input data stream and input clock rate, each of the pair of data streams being comprised of even or odd bits from the input data stream and a half-rate clock signal, apparatus for carrying the pairs of data and clock streams on separate transmission facilities, a receiver for receiving the pairs of data and clock streams via undifferentiated inputs, apparatus in the receiver for automatically determining the odd and even nature of the bit data streams and apparatus for interleaving the odd and even bit streams in proper order and with timing relative to the framing patterns to provide an output signal at the same data rate as the input data stream. In accordance with another embodiment, for use in a transmission system in which an input data stream is transmitted in plural data streams each at a fraction of the input data stream rate and plural clock stream pairs each at said fraction of the input data clock rate, a receiver is comprised of apparatus for receiving the plural data streams, apparatus for determining frame timing differences between frame signals contained in each of the received plural data streams, apparatus for varying the timing of one received data stream relative to another, whereby their relative timing is adjusted, apparatus for combining the timing adjusted plural data streams into an output data stream having similar data stream rate as the input data stream, apparatus for recovering a clock from one of the plural data streams, and for generating an output clock signal therefrom at the input data clock rate, and apparatus for aligning the output data stream with the output clock signal, whereby an output data stream and an output clock signal are provided having similar data rates as the input data stream and clock rates. In accordance with another embodiment of the invention, for use in a transmission system in which an input data stream is transmitted in a pair of data streams each at a fraction of the input data stream rate and a pair of clock stream pairs each at said fraction of the input data clock rate, a receiver is comprised of apparatus for receiving the pair of data streams, apparatus for determining frame timing differences between frame signals contained in each of the received pair of data streams, apparatus for varying the timing of one received data stream relative to another, whereby their relative timing is adjusted, apparatus for detecting which of a stream of data frames contains odd framing patterns and which of a stream of data patterns contains even framing patterns, apparatus for reversing the even or odd sense of the framing patterns in the event the skew of the framing patterns relative to the data of one data stream is greater than a predetermined number of bits, apparatus for varying the timing of one data stream relative to the other with odd and even frames of data in correct order as determined by the odd and even frame detecting and sense reversing means, and apparatus for combining the timing adjusted plural data streams into an output data stream having similar data stream rate as the input data stream, whereby an output data stream having a similar data sequence as the input data stream is provided. BRIEF INTRODUCTION TO THE DRAWINGS A better understanding of the invention will be obtained by reading the description of the invention below, with reference to the following drawings, in which: FIG. 1 is a block diagram of a system in which the invention may be implemented, FIG. 2 is a logic diagram of a framer transmitter used in the system of FIG. 1, and FIGS. 3A and 3B, placed together, is a logic diagram of a preferred form of pair division multiplex receiver and near end framer receiver, DETAILED DESCRIPTION OF THE INVENTION A transmission in which the invention may be implemented is illustrated in FIG. 1. An input digital data bit stream is received by a pair division multiplex transmitter 1, the data bit stream contains repeating, adjacent multi-bit framing patterns and a synchronous clock. Transmitter 1 splits the input data and clock stream into two data and clock stream pairs, each operating at on-half the bit rate of the input data bit stream, and applies them via paths 3 to a line interface transmitter 5. It is unimportant which stream contains the even bits, and which contains the odd bits, since in accordance with this invention, a downstream receiver automatically detects the correct relationship thereof. The line interface transmitter performs line encoding, pulse shaping and buffering, and applies the two data streams for transmission over a wiring facility 7. The wiring facility can be two pair of twisted wires, as is often found in offices or homes. The two data streams travel down the twisted wire facility, and are received by line interface receivers 9. which recover and decode the data signals and derive the data clock signals. The resulting data and clock signal streams are applied to a pair division multiplex receiver 11, where the data and clock signals are recombined into a single output data and a single output clock stream. The recombined data and clock stream from receiver 11 are applied to a near end framer receiver 13 which contains circuitry which determines proper frame alignment on the recombined stream. The near end framer receiver indicates its framing state with an out-of-frame (OOF) indication signal, which is passed to the pair division multiplex receiver to control its operation. When the OOF signal is at high logic level, the pair division multiplex receiver actively searches for proper framing alignment, even/odd pair selection, and deskews the two input data streams. When OOF is at low logic level, the pair division multiplex receiver is held in a fixed state. From the standpoint of the signals from the input data to the output data streams, the system is completely transparent to the digital data stream. Turning to FIG. 2, a logic diagram of a framer transmitter 1 as may by used in the system of FIG. 1 is illustrated. The input transmit clock signal TXCLK is divided by two by a flip flop 15, the true and complement output phases being applied to the set inputs S of multiplexer-flip flop pairs 16, 17 and 18, 19, and providing two half rate clock signals CLKA and CLKB. The input data signal is applied to the data inputs B of the multiplexers 16, 18. The output signals of the flip flops 17 and 19 are applied to the respective data inputs D of flip flops 20 and 21, in which they are retimed by the half-rate CLKA and CLKB signals. The result is a pair of digital data and clock streams, SDOUTA and CLKA, and SDOUTB and CLKB. One output stream is comprised of all of the even bits derived from the TXDAT input signal and the other output stream is comprised of all of the odd bits derived from the TXDAT input signal. It is not important which stream is even or odd, since the receiver circuit makes the correct determination. The above described design, using multiplexers and flip-flops followed by retiming with the half-rate clocks minimizes the skew between the data and clock pairs SDOUTA/CLKA and SDOUTB/CLKB. Minimization of skew is important to provide the maximum timing margins for the line interface unit transmitters. Turning now to FIGS. 3A and 3B, which are placed together side by side with FIG. 3A to the left of FIG. 3B, the pair division multiplex and near end framer receivers are shown in detailed logic form. The receivers take the even and odd data streams which contain even and odd framing bits, and determine the frame alignment of each stream. Even though at the transmitter these two streams have a fixed timing relationship, there is no guarantee of this when the streams reach the receiver. This difference is due to differences in the electrical length of the two wiring pairs with respect to each other. This can occur due to variations in manufacturing of the wiring cable, details of cable installation, or due to using pairs from non-related cables. The two data stream signals are decoded in line interface unit receivers 9 (FIG. 1), wherein the two clock signals are also recovered. The two data streams, referred to herein as the A stream and the B stream, share a common clock frequency, but the two recovered clock signals CLKA and CLKB will be only arbitrarily aligned in phase. For this reason, a preferably 4 bit data alignment FIFO 22 is used to realign the B stream data to the CLKA clock signal. The B stream data is received from a line interface unit receiver and is applied to the D input of FIFO 22, the CLKB clock signal being applied to its write clock input C. The A stream clock signal CLKA is applied to the read clock input C. The four bit FIFO has a two clock cycle delay. Logic within the FIFO ensures that the FIFO is normally centered for a two cycle delay. In order to match the resulting B data stream delay, the A stream is also delayed by two clock cycles, by applying the A stream data SDINA to the D input of flip flop 24, which has its Q output connected to the D input of flip flop 26. Both flip flops 24 and 26 are clocked by the CKLA A stream clock signal. The delay compensation is inserted in order to allow the circuit to adjust equally for both positive and negative skews between the A and B data streams. The two streams of input data have thus been aligned to the CLKA clock signal, a common timing base which will be used to operate most of the receiver circuitry, and the delay inserted in the B data stream has been compensated, in data alignment and delay compensator circuit 28. A stream data output from the flip flop 26 is applied to the input of a shift register 30. The length of the shift register should depend on two factors; (a) the length of the framing pattern to be detected (eight bits, in the present example), and (b) the maximum expected skew between the two data streams. In this example, the skew can be eight bits. At the SONET STS-1 standard rate of 51 Mbit/s, this eight bits represent about 157 nanoseconds. If the maximum cable length is 100 meters, and signals travel at a speed of about 1.5×10 8 meters per second in the cable (one half the speed of light), this means that the maximum cable length variation can be about 23.5 meters, or about ±12%. At the SONET STS-3 standard rate of 155 Mbit/s, this cable length variation would be reduced to about ±4%. A 24 bit shift register can be used to allow ±12% at 155 Mbits/s. For SONET protocols, the total number of framing bits used for STS-3 is 48 bits, the number for STS-1 is 16 bits. The increase in shift register length that is necessary to decode these framing bits is also the required increase to allow for a constant percentage skew accommodation. For SONET STS-3, however, it is not necessary to decode all 48 framing bits (24 in each framing pattern detector), since the same frame detect logic used for STS-1 will operate properly for STS-3 as well. Using the extra framing bits, however, will reduce the time to find frame alignment. The A bit stream framing pattern detector 32 logic decodes both the odd and even framing bits for each pair. The resulting signals, shown as AEVEN and AODD in FIG. 3A, are decoded to the hexadecimal `D6` and `E0` for the SONET STS-1 and STS-3 respectively. It is important that both odd and even pattern detections are performed for each pair of signals, so that pair select circuitry can automatically determine which one of the A or B data streams contains the even framing bits, and which one contains the odd framing bits. This simplifies wiring installation costs by making the proper connections of the wiring pairs to the equipment (between the transmitter and receivers) less important, and it simplifies the design of the transmitter, which can arbitrarily choose even and odd assignment without knowledge of frame boundaries. A B data stream shift register 34, having equal length as the A data stream shift register 30, receives the B data stream data signal from the output of FIFO 22, and a B data stream framing pattern detector 36 logic decodes both the odd and even framing bits for each pair of signals of the B data stream. The resulting signals are shown as BEVEN and BODD, and as for the A data stream, are decoded to `D6` and `E0` respectively for the SONET STS-1 and STS-3 examples. The outputs of shift register 30 are applied to a 1-of-eight multiplexer 38. This multiplexer provides for programming of input to output delay of the A data bit stream. The multiplexer 38 should be the same length as the maximum skew length in bits, which will usually be the same length as the A and B bit stream shift registers 30 and 34. The delay is set by the inputs to S1, S2 and S3. The output signal from multiplexer 38 is shown as ADLY, and constitutes the delayed A data stream, and can change in a range from one to eight bit periods. Since the B data stream BDLY from shift register 34 has been delayed by four bit periods in FIFO 22, the adjustment capability on the ADLY signal allows for a relative adjustment range of -3 to +4 bit periods of delay of the ADLY signal with respect to the BDLY signal, thus removing skew between the A and B data streams. An offset counter 40 and associated circuitry in skew calculator 42 calculate and store the value of the relative time skew between the A and B data streams. Offset counter 40 calculates the skew between the A and B data streams. Whenever external logic determines that the data stream is out of frame alignment, it applies a logic high level on the OOF lead. The AEVEN and AODD signals are applied to respective inputs of a multiplexer 44, the output of which is applied to one input of NAND gate 46. The OOF signal is applied to the other input of NAND gate 46. If the OOF lead is at high logic level, the output of the NAND gate 46 is the CRSTB signal Similarly, the BEVEN and BODD signals are applied to multiplexer 48 (to the opposite corresponding inputs as the AEVEN and AODD inputs to multiplexer 44). The output of multiplexer 48 is applied to one input of NAND gate 50, the other input receiving the OOF signal, the output of gate 50 being the CLATCHB signal. It should be noted that an MPX SET signal is applied to the S inputs of both multiplexers 44 and 48, which, when high, causes reversal of the phases of the A and B data streams output from the multiplexers. When the logic high level is on the OOF lead, due to the data stream being out of frame alignment, either an even or odd framing pattern detected by the A data stream frame pattern detector 32, as determined by the multiplexer 44, causes the CRSTB signal to pulse low for one clock cycle. Offset counter 40 is cleared, and begins counting. A register 50 receives a count output from offset counter 40, and stores it. The Q0, Q1 and Q2 outputs of register 50 are applied to respective inputs of EXCLUSIVE OR gates 52, which have their outputs connected to corresponding inputs of NOR gate 63. The other inputs of EXCLUSIVE OR gates 52 are connected to corresponding outputs of counter 40. The outputs of counter 40 which are connected to inputs of EXCLUSIVE OR gates 52 are connected to offset latch 52. The outputs of offset latch 52 are the delay set signal, applied to the delay set control inputs S1, S2 and S3 of multiplexer 38. During normal operation, the B data stream frame pattern detector 36 indicates either an odd or even framing pulse pattern within eight clock cycles of the CRSTB pulse, and will drive the CLATCHB signal low for one clock cycle. When the CLATCHB pulses low the value from the offset counter 40 is compared with the previous value stored in register 50, which has received its value via its D0, D1 and D2 inputs from the Q0, Q1 and Q2 outputs of counter 40. If the two values are the same, indicated by the output of gate 63 going high, the OFF -- LATCHB signal pulses low and the offset counter 40 value is stored in offset latch 52. If the two values are not the same, the value stored in offset latch 52 is not changed. In either case, the current offset counter 40 value is stored in the register 50 for future use. By ensuring that two identical framing patterns occur in succession, the circuit is made immune to false framing patterns causing changes in the delay adjust selector. This is of importance for reliable operation and fast frame alignment. Pair select (A or B odd and even data stream) circuitry 53 is comprised of EXCLUSIVE OR gate 54 having its output connected to the D3 input of register 50 and one input connected to the Q3 output of register 50. Its other input is connected to the output of AND gate 56, which has its inputs connected to the Q0, Q1 and Q2 outputs of pair select counter 58. Each of those outputs and output Q3 are connected to corresponding inputs D0, D1, D2 and D3. The Q3 output of counter 40 is connected to one input of NOR gate 60, which has its output connected to the SR data input of counter 58. The Q3 output of counter 40 is also connected to the input of inverter 62, the output of which is connected to the LD input of counter 40. The output of inverter 62 is also connected to the other input of NOR gate 60. The above-described pair select circuitry, with part of register 50, automatically determines which of the A or B data streams contains the even and odd framing patterns. The circuitry operates with the assumption that if even and odd framing pattern detection sequences do not occur within eight clock cycles of each other, the selection of even/odd polarity may need to be reversed. To prevent erroneous assumptions about the even/odd polarity, several successive violations of the sequence must be detected before the state reversal occurs. When the CLATCHB pulse does not occur within the allowed-for time (e.g. eight clock cycles) after the CRSTB pulse occurs, the offset counter 40 saturates at its maximum value, (which in the present example is the value of eight, but depends on the maximum skew adjustment range). When the CRSTB signal occurs, the pair select control counter 58 increments by one. After several successive sequences (seven in this example) with the offset counter 40 saturating, the pair select control decoder (AND gate 56) outputs a high level logic signal, causing the PAIR -- SEL signal (applied to the control input of multiplexers 44 and 48) to change state on the next CLATCHB pulse. If a correct CRSTB-CLATCHB sequence occurs within the eight clock cycles allowed, the pair select control counter 58 will be cleared, forcing the count sequence to start over. Therefore if there are eight successive CLATCHB pulses that do not occur within eight clock cycles after a CRSTB pulse, it is assumed that the sense of the even/odd pairs is reversed. The PAIR-SEL signal reverses state, causing the multiplexers 44 and 48 to invert the phases of the odd and even bitstreams, and the circuit again searches for correct framing pattern alignment. This operation assumes that if A and B bit stream framing pulses are occurring, but that they are not within the skew time budget, then the odd and even transmission wiring pairs must be reversed. The pair select control circuitry 53 then reverses the even/odd sense in multiplexers 44 and 48, and tries again to align with the even/odd pattern detect logic pulses reversed. The circuitry will continue to reverse the even/odd sense and attempt to find a frame until a valid pattern is detected, as indicated by the OOF signal being driven to low logic level by the aforenoted external logic. The above circuit provides an unique, simple and low cost circuit that facilitates the connection of twisted pair wiring. The installer does not have to be concerned about "odd" or "even" pairs connected at the input to the receivers, and the transmitter does not need to be synchronized to frame boundaries. The lowers the installation and support cost of systems that use the present invention. As noted above, the pair select multiplexers 44 and 48 reverse the sense of the A and B data streams from even to odd and vice versa. However, instead of placing them as shown, they could instead have been connected in series with the data lines connected to the inputs of the channel shift registers 30 and 34, to switch the serial input data and clock lines between the A and B data streams. However, when connected as shown in the figure, the number of logic elements in the high speed clock lines is minimized. The delayed A and B channel data streams ADLY and BDLY are applied to respective inputs to multiplexer 64, the CLKA clock signal being applied to its S (control) input. As a result the ADLY and BDLY data streams are interleaved at double the clock rate of the ADLY and BDLY signals. The output of multiplexer 64 is applied to the D input of flip flop 66. Clock doubler 68 receives the CLKA clock signal and doubles its rate, applying the resulting double rate clock signal to the clock C input to flip flop 66. This retimes the combined data stream. The result is an output data stream DOUT and a clock stream CKOUT which is identical to the input data stream and input clock stream at the input to transmitter 1. An external framer device referred to earlier (not shown) analyzes the DOUT data stream, and determines if the combined data stream is correctly aligned by attempting to find a normal correct framing sequence and then verifying that this sequence repeats at the expected rate. If it does, it drives the OOF signal to low logic level, which freezes the operation of the delay synchronization circuit by locking gates 46 and 50. If the external framer device should fall out of frame for any reason, then the OOF signal is driven high, and the circuitry described above will begin realignment. It is intended that the invention is not restricted to the two conductor A and B single bit lines, but that the transmitter should multiplex plural (such as eight) bit wide bit streams to two bit streams, transmit them to the receiver, and at the receiver demultiplex from two to the plural (such as eight) bit wide streams. The transmission rates described are representative for the example given, but other transmission rates can be used, with longer channel shift registers and longer channel frame pattern detectors. Other transmission protocols than the example ones given herein, with adjacent time framing patterns can be used, such as European E-3 or European E-4 formats. The framing detect patterns can be register programmable. Further, multiple stages of the present invention can be cascaded, in order to allow the use of more pairs of wiring than the two described herein. A person understanding this invention may now conceive of alternative structures and embodiments or variations of the above. All of those which fall within the scope of the claims appended hereto are considered to be part of the present invention.

For use in a transmission system in which an input data stream is transmitted in plural data streams each at a fraction of the input data stream rate and plural clock stream pairs each at the fraction of the input data clock rate, a receiver, comprised of apparatus for receiving the plural data streams, apparatus for determining frame timing differences between frame signals contained in each of the received plural data streams, apparatus for varying the timing of one received data stream relates to another, whereby their relative timing is adjusted, apparatus for combining the timing adjusted plural data streams into an output data stream having a similar data stream rate as the input data stream, apparatus for recovering a clock from one of the plural data streams, and for generating an output clock signal therefrom at the input data clock rate, and apparatus for aligning the output data stream with the output clock signal, whereby an output data stream and an output clock signal are provided having similar data rates as the input data stream and clock rates.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a pneumatic tire. The present invention specifically relates to a pneumatic tire capable of suppressing stone trapping. 2. Description of the Related Art Stones are sometimes trapped within grooves that are formed on the tread area of pneumatic tires of vehicles. When the stones are trapped within the grooves, so-called “stone drilling” may occur. The stone drilling is a phenomenon that stones penetrate the bottoms of the grooves due to rolling of the pneumatic tire to cause damage to the tread area. To take care of this issue, some of the conventional pneumatic tires have protrusions in the grooves to minimize stone trapping in the grooves. Due to the provision of the protrusions, even if stones enter the grooves, the stones are ejected to the outside of the grooves by the elastic force of the protrusion. When manufacturing pneumatic tires having protrusions in the grooves, however, the protrusions become obstacle to flow of rubber for forming the tread area inward in the tire radial direction of the protrusion. This may increase the pressure of the rubber located inward of the protrusion in the tire radial direction, and associated with this, a breaker ply located inward of the protrusion in the tire radial direction can get deformed into a wavy shape. If the breaker ply is deformed in this manner, abnormal wear may occur to the pneumatic tire due to the deformation in the breaker ply when a vehicle to which the pneumatic tires are fit travels. Some of the conventional pneumatic tires have a configuration that makes it possible to suppress the deformation of the breaker ply when the protrusions are provided in the grooves. For example, in Japanese Patent Application Laid-Open No. S61-291203, a plurality of protrusions are provided in grooves that extend in a zigzag shape in the tire circumferential direction, and connection members for connecting the protrusions to the sidewalls of the grooves are provided in locations where the adjacent protrusions in the tire circumferential direction are provided alternately in the tire width direction. In such a structure, the rubber located inward of the protrusion in the tire radial direction can escape in the direction of a land during manufacture of the pneumatic tire. It is, therefore, possible to prevent the pressure of the rubber located inward thereof in the tire radial direction from becoming too high. Consequently, it is possible to suppress the deformation of the breaker ply located inward of the protrusion in the tire radial direction and to reduce the abnormal wear. The protrusion provided in the groove ejects the stone entering the groove to the outside of the groove by the elastic force of the protrusion, and prevents the stone trapped within the groove from reaching the breaker ply by the volume of the protrusion. Therefore, the protrusion needs to have a predetermined height and a predetermined volume to fulfill these functions. Greater effect of suppressing stone trapping can be obtained if the height is larger or if the volume is larger. However, if the protrusion is too large, then the rubber does not satisfactorily flow into a mold for forming the protrusion, and it is difficult to discharge the air present between the mold and the rubber during manufacture of the pneumatic tire. As a result, the pneumatic tire is manufactured without obtaining a targeted shape of the protrusion, which causes failure in manufacture, i.e., occurrence of “bare” (depressed area). SUMMARY OF THE INVENTION It is an object of the present invention to at least partially solve the problems in the conventional technology. According to an aspect of the present invention, a pneumatic tire having a tread area, the tread area being divided into a plurality of lands by virtue of a plurality of grooves, includes a plurality of protrusions on a bottom of each of the grooves, a height of the protrusion from the bottom of the groove in a profile of the protrusion in a circumference direction of the pneumatic tire being variable, the protrusion including at least one peak portion that protrudes away from a center of the pneumatic tire; and a connection member between the protrusion and an adjacent one of the lands, the connection member having a first end toward the land and a second end toward the peak portion, a height of the first end from the bottom of the groove being larger than that of the second end. The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a tread area of a pneumatic tire according to an embodiment of the present invention; FIG. 2 is a detailed diagram of the portion A of FIG. 1 ; FIG. 3 is a cross-section taken along the line B-B of FIG. 2 ; FIG. 4 is a cross-section taken along the line C-C of FIG. 3 ; FIG. 5 is a perspective view of a protrusion and a connection member; FIG. 6 is a cross-section of the pneumatic tire for explaining a state in which a stone is trapped within a groove of the pneumatic tire; FIG. 7 is a cross-section of the pneumatic tire for explaining how the stone shown in FIG. 6 moves; FIG. 8 is a schematic of a mold and a tread rubber for explaining a state before the tread area is subjected to vulcanization molding; FIG. 9 is a schematic of the mold and the tread rubber for explaining the state in which the tread area is being subjected to the vulcanization molding; FIG. 10 is a schematic of the mold and the tread rubber for explaining the state in which the tread area is being subjected to the vulcanization molding and which is subsequent to the state shown in FIG. 9 ; FIG. 11 is a detailed cross-section of a pneumatic tire according to another embodiment of the present invention; and FIG. 12 is a cross-section taken along the line D-D of FIG. 11 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings. It is to be noted that the present invention is not limited by the embodiments. Constituent elements explained in the following embodiments include those easily replaceable therewith by persons skilled in the art, or those substantially equivalent thereto. Types of pneumatic tires include a block type tread, a ribbed tread, and a ribbed-lug tread. In the following embodiments, the pneumatic tire having the block type tread will be explained as an example of the pneumatic tire. In the embodiments, a tire width direction means a direction parallel to a rotating axis of the pneumatic tire, an inward in the tire width direction means a direction toward an equatorial plane in the tire width direction, and an outward in the tire width direction means a direction opposite to the direction toward the equatorial plane in the tire width direction. Moreover, a tire radial direction means a direction orthogonal to the rotating axis, and a tire circumferential direction indicates a direction of the tire rotating around the rotating axis. FIG. 1 is a schematic of a tread area 10 of a pneumatic tire 1 according to an embodiment of the present invention. The tread area 10 , which is made of an elastic rubber material, is formed on an outermost side in the tire radial direction. A surface of the tread area 10 , namely, a portion of the pneumatic tire 1 contacting a surface of the road when a vehicle (not shown) on the pneumatic tires 1 runs, is formed as a tread surface 11 . A plurality of grooves 20 including those formed in predetermined directions is formed in the tread area 10 . The grooves 20 include a plurality of longitudinal grooves 21 formed in the tire circumferential direction and a plurality of lateral grooves 22 formed in the tire width direction. The tread area 10 is divided by the longitudinal grooves 21 and the lateral grooves 22 into a plurality of blocks 15 , which blocks are to serve as lands. Protrusions 30 are arranged at intervals in the grooves 20 for both the longitudinal grooves 21 and the lateral grooves 22 , respectively. The longitudinal groove 21 and the lateral groove 22 are not necessarily formed accurately in the tire circumferential direction or the tire width direction. It suffices that each longitudinal groove 21 is formed substantially in the tire circumferential direction. Namely, the longitudinal groove 21 can be formed aslant with respect to the tire width direction, formed to be curved, or formed into a zigzag shape. It suffices that each lateral groove 22 is formed substantially in the tire width direction. Namely, the lateral groove 22 can be formed aslant with respect to the tire circumferential direction, formed to be curved, or formed into a zigzag shape. FIG. 2 is a detailed diagram of the portion A of FIG. 1 . FIG. 3 is a cross section taken along the line B-B of FIG. 2 . FIG. 4 is a cross section taken along the line C-C of FIG. 3 . FIG. 5 is a perspective view of the protrusion 30 and a connection member 40 . The protrusion 30 made of the same rubber material as that of the tread area 10 is formed apart from the blocks 15 or from groove walls 23 of the grooves 20 . The protrusion 30 is formed to protrude outward in the tire radial direction from a groove bottom 24 of the groove 20 . The protrusion 30 is also formed so that its height is smaller than that of the block 15 , namely, smaller than a distance from the groove bottom 24 to the tread surface 11 . The height of the protrusion 30 thus formed, from the groove bottom 24 , is changed. In other words, the protrusion 30 includes a convex portion 31 and a slope 35 . The convex portion 31 protrudes outward in the tire radial direction. The slope 35 is formed such that its height from the groove bottom 24 is getting smaller as it is farther from the convex portion 31 . The convex portion 31 has a top 32 that is the highest from the groove bottom 24 and parallel to the groove bottom 24 . The slope 35 is provided on each side of the convex portion 31 in the direction in which the groove 20 is formed. The convex portion 31 and the slopes 35 of the protrusion 30 are respectively formed to be generally rectangle when the protrusion 30 is viewed in the depth direction of the groove 20 . The connection member 40 is formed between the protrusion 30 thus shaped and the block 15 . The connection member 40 is connected to both the convex portion 31 of the protrusion 30 and the block 15 . A connection end of the connection member 40 , which end is connected to the convex portion 31 is a convex-side end 41 , and a connection end of the connection member 40 , which end is connected to the block 15 is a block-side end 42 or a land-side end. The convex-side end 41 is connected to a block 15 -side surface of the convex portion 31 , and the block-side end 42 is connected to a protrusion 30 -side surface of the block 15 or to a portion of the groove wall 23 opposing the convex portion 31 . The block-side end 42 is formed so that its height from the groove bottom 24 is larger than that of the convex portion 31 from the groove bottom 24 . More specifically, an outward surface 43 of the connection member 40 , which surface is located outward in the tire radial direction, is inclined with respect to the groove bottom 24 . The outward surface 43 is inclined in the direction in which it is farther from the groove bottom 24 as it directs from the convex-side end 41 toward the block-side end 42 . Alternatively, the outward surface 43 is inclined to be gradually located outward in the tire radial direction. In other words, the connection member 40 is formed so that its height from the groove bottom 24 is getting larger from the convex-side end 41 toward the block-side end 42 . Therefore, the relation between the convex portion 31 and the connection member 40 is represented by h 2 >h 1 , where h 1 is the height of the convex portion 31 from the groove bottom 24 and h 2 is the height of the connection member 40 from the groove bottom 24 . Namely, the height of any part of the connection member 40 from the groove bottom 24 is always larger than that of the convex portion 31 from the groove bottom 24 . An inclination angle θ of the outward surface 43 with respect to the groove bottom 24 , i.e. an inclination angle θ with respect to the groove bottom 24 from the convex-side connection end 41 over the block-side end 42 is preferably in a range from 3 degrees to 45 degrees. Furthermore, a width of the connection member 40 in the direction in which the groove 20 is formed is preferably almost the same as that of the convex portion 31 in the same direction or as that of the top 32 in the same direction. Moreover, the connection member 40 is preferably formed to satisfy the relation represented by 0.05h 1 ≦W≦1.0h 1 , where h 1 is the height of the convex portion 31 from the groove bottom 24 and W is the width of the connection member 40 in the direction in which the groove 20 is formed. FIG. 6 is a cross-section of the pneumatic tire 1 for explaining a state in which a stone 50 is trapped within the groove. FIG. 7 is cross-section of the pneumatic tire for explaining how the stone 50 shown in FIG. 6 moves. When the vehicle with the pneumatic tires 1 runs, the pneumatic tire 1 rotates while a lower part of the tread surface 11 is in contact with the road surface (not shown). At this time, the stone 50 is often present on the road surface. If the groove 20 passes through the road surface on which the stone 50 is present, the stone 50 often enters the groove 20 and is trapped within the groove 20 . If the stone 50 is trapped within the groove 20 , then the stone 50 contacts with the road surface through rotation of the pneumatic tire 1 , and is forced inward in the tire radial direction. The stone 50 forced inward in the tire radial direction contacts with the groove bottom 24 or the protrusions 30 . When the vehicle is running, the pneumatic tire 1 rotates even in this state. Therefore, the stone 50 that is pushed out of the groove 20 due to its size which is greater than the depth of the groove 20 , that is, the stone 50 protruding from the tread surface 11 outward in the tire radial direction contacts with the road surface when the stone 50 is present on the road surface side by rotation of the pneumatic tire 1 . At this time, frictional force acts between the stone 50 in contact with the road surface and the road surface. Furthermore, because of the rotation of the pneumatic tire 1 , a force for moving the stone 50 in the opposite direction to the rotation direction of the pneumatic tire 1 in the groove 20 in the direction in which the groove 20 is formed acts on the stone 50 . The protrusions 30 are provided at intervals in the groove 20 , and each of the protrusions 30 includes the slopes 35 . Each of the slopes 35 is formed so that its height from the groove bottom 24 is getting smaller as it is farther from the convex portion 31 . In other words, the slope 35 is formed so that its height from the groove bottom 24 is getting larger from a location apart from the convex portion 31 toward the convex portion 31 . The protrusion 30 is made of the same rubber material as that of the tread area 10 is formed. Therefore, the protrusion 30 has an elastic force. Because of the elastic force of the protrusion 30 , if the stone 50 is to touch the protrusion 30 , the stone 50 is affected by the force that moves the stone 50 from the state in which it is trapped within the groove 20 . When the pneumatic tire 1 rotates, the force for moving the stone 50 in the direction opposite to the rotation direction also acts on the stone 50 trapped within the groove 20 . The stone 50 , therefore, moves in the direction in which the groove 20 is formed. If the stone 50 touches the slope 35 of the protrusion 30 , the stone 50 moves along the slope 35 . Furthermore, if the moving direction of the stone 50 along the slope 35 is a moving direction from a position apart from the convex portion 31 toward the convex portion 31 , the stone 50 moves toward the top 32 of the convex portion 31 along the slope 35 . The moving direction of the stone 50 along the slope 35 is often a moving direction from a position near the convex portion 31 toward a position apart from the convex portion 31 . In the latter case, similarly to the former case, the stone 50 further moves to touch the slope 35 of the adjacent protrusion 30 because a plurality of protrusions 30 are formed at intervals in the groove 20 . The stone 50 thereby moves toward the top 32 of the convex portion 31 when moving along the slope 35 . In either case, the stone 50 moving in the groove 20 moves in the direction in which the groove 20 is formed, and also moves outward in the tire radial direction. When the stone 50 reaches the position of the top 32 , a large part of the stone 50 is exposed from the groove 20 and a part thereof trapped within the groove 20 decreases. As a result, the stone 50 is ejected to the outside of the groove 20 . Consequently, penetration of the stone 50 into the tread area 10 such as the groove bottom 24 can be suppressed. That is, the occurrence of stone drilling can be minimized. The movement of the stone 50 trapped within the groove 20 in the direction in which the groove 20 is formed according to the rotation of the pneumatic tire 1 occurs mainly when the stone 50 is trapped within the longitudinal groove 21 . However, if the lateral groove 22 is formed aslant or if the vehicle with the pneumatic tire 1 is in the cornering mode, i.e., taking a turn at a corner of the road, the stone 50 trapped within the lateral groove 22 sometimes moves in the direction in which the lateral groove 22 is formed due to the rotation of the pneumatic tire 1 . Therefore, whether the groove 20 trapping the stone 50 is the longitudinal groove 21 or the lateral groove 22 , the stone 50 moves in the direction in which the groove 20 is formed, and the protrusion 30 causes the stone 50 to move outward in the tire radial direction and to be ejected to the outside of the groove 20 . Consequently, penetration of the stone 50 into the tread area 10 such as the groove bottom 24 can be suppressed, and the occurrence of stone drilling can be minimized. FIG. 8 is a schematic of a mold 60 and a tread rubber 70 for explaining a state before the tread area 10 is subjected to vulcanization molding. Part of manufacturing processes for the pneumatic tire 1 is explained below. If the tread area 10 is to be molded during manufacture of the pneumatic tire 1 , the mold 60 is used for vulcanizing the tread area 10 . The mold 60 is formed into such a shape that convex and concave portions of the tread surface 11 are reversed. More specifically, the mold 60 includes a block-part mold 61 and a groove-part mold 62 . The block-part mold 61 is of the concavely shape, which is reverse to the shape of the block 15 formed on the tread surface 11 . The groove-part mold 62 is of the convex shape, which is reverse to the shape of the groove, 20 formed in the tread area 10 . The groove-part mold 62 includes a protrusion-part mold 63 and a connection-member-part mold 64 which are of the concave shapes, which are reverse to the protrusion 30 and the connection member 40 formed convexly in the groove 20 , respectively. The connection-member-part mold 64 is located between the protrusion-part mold 63 and the block-part mold 61 and connected to both the protrusion-part mold 63 and the block-part mold 61 . This is similar to the connection member 40 of the pneumatic tire 1 which is connected to both the protrusion 30 and the block 15 . A vent hole 65 is formed in the block-part mold 61 to communicate the block-part mold 61 with the outside of the mold 60 . When the pneumatic tire 1 is to be vulcanized using the mold 60 thus formed, the mold 60 is situated in the outward of the tread rubber 70 in the tire radial direction. The tread rubber 70 is rubber that corresponds to the tread area 10 , and that is part of a green tire which is the pneumatic tire 1 before the vulcanization molding. At this time, the mold 60 is directed so that the block-part mold 61 , the groove-part mold 62 , the protrusion-part mold 63 , and the connection-member-part mold 64 oppose the tread rubber 70 . FIG. 9 is a schematic of the mold 60 and the tread rubber 70 for explaining the state in which the tread area 10 is being subjected to the vulcanization molding. When the pneumatic tire 1 is to be vulcanized, pressure is applied to the green tire from the inward to the outward in the tire radial direction. As a result, the tread rubber 70 contacts with the mold 60 . The pressure is further applied to the green tire outward in the tire radial direction. The tread rubber 70 is thereby deformed to fit the shape of the mold 60 of the part opposing the tread rubber 70 . In other words, the tread rubber 70 located in the block-part mold 61 flows into the concave block-part mold 61 . Likewise, the tread rubber 70 flows into the concave protrusion-part mold 63 and the concave connection-member-part mold 64 . Conversely, the tread rubber 70 contacts with the convex groove-part mold 62 in the early stage of the vulcanization molding. In this manner, the tread rubber 70 is pressurized against the mold 60 from the inward to the outward in the tire radial direction during the vulcanization molding. However, because the tread rubber 70 contacts with the mold 60 from its part located inward of the mold 60 in the tire radial direction, the air present between the mold 60 and the tread rubber 70 flows from the inward to the outward in the tire radial direction. For example, the tread rubber 70 flows into the protrusion-part mold 63 from the inward to the outward in the tire radial direction. The air in the protrusion-part mold 63 flows to the outward in the tire radial direction. Furthermore, the convex portion 31 is formed on the protrusion 3 and is a portion of the protrusion 30 , which portion protrudes outward in the tire radial direction. The air flowing in the tire radial direction during the vulcanization molding, therefore, flows to a portion of the protrusion-part mold 63 where the convex portion 31 is molded. The connection-member-part mold 64 is connected to the protrusion-part mold 63 . The connection-member-part mold 64 is formed outward in the tire radial direction relative to the protrusion-part mold 63 , and connected to both the protrusion-part mold 63 and the block-part mold 61 . This is similar to the connection member 40 formed so that its height from the groove bottom 24 is larger than that of the convex portion 31 . Therefore, the tread rubber 70 flows into the protrusion-part mold 63 . The air in the protrusion-part mold 63 flowing outward in the tire radial direction thereby flows in the direction of the block-part mold 61 through the connection-member-part mold 64 . More specifically, the connection member 40 is formed so that its height from the groove bottom 24 is getting larger from the convex-side end 41 toward the block-side end 42 . The connection-member-part mold 64 is, therefore, formed to correspond to the connection member 40 . Namely, the connection-member-part mold 64 is formed to gradually extend outward of the protrusion-part mold 63 in the tire radial direction from the protrusion-part mold 63 to the block-part mold 61 . Therefore, the air flowing between the protrusion-part mold 63 mold 64 and the tread rubber 70 easily flows from the position corresponding to the convex-side end 41 toward the position corresponding to the block-side end 42 . The air can thereby flow more surely from the direction of the protrusion-part mold 63 to the direction of the block-part mold 61 . The air in the block-part mold 61 flows outward in the tire radial direction by the flow of the tread rubber 70 into the block-part mold 61 . Because the vent hole 65 is provided in the block-part mold 61 , the air in the block-part mold 61 flowing outward in the tire radial direction flows into the vent hole 65 , and is discharged from the vent hole 65 to the outside of the mold 60 . With this discharge, the air in the protrusion-part mold 63 flowing in the direction of the block-part mold 61 through the connection-member-part mold 64 is also discharged to the outside of the mold 60 through the vent hole 65 . FIG. 10 is a schematic of the mold 60 and the tread rubber 70 for explaining the state in which the tread area 10 is being subjected to the vulcanization molding and which is subsequent to the state shown in FIG. 9 . The tread rubber 70 is pressed outward in the tire radial direction during the vulcanization molding of the pneumatic tire 1 as shown in FIG. 9 . The air in the protrusion-part mold 63 thereby flows in the direction of the block-part mold 61 through the connection-member-part mold 64 , while the tread rubber 70 contacts with the mold 60 from its inward part in the tire radial direction. Therefore, during the vulcanization molding of the pneumatic tire 1 , the tread rubber 70 in the protrusion-part mold 63 contacts with the mold 60 more early than the tread rubber 70 in the connection-member-part mold 64 . Consequently, almost all of the air present between the protrusion-part mold 63 of the mold 60 and the tread rubber 70 flows in the direction of the block-part mold 61 through the connection-member-part mold 64 . Therefore, when the tread rubber 70 located in the protrusion-part mold 63 contacts with the protrusion-part mold 63 while the tread rubber 70 is continuously pressed, no air is left between the protrusion-part mold 63 and the tread rubber 70 . In addition, almost all the tread rubber 70 located in and opposing the protrusion-part mold 63 directly contacts with the protrusion-part mold 63 . The tread rubber 70 located in the connection-member-part mold 64 contacts with the connection-member-part mold 64 after almost all the tread rubber 70 located in and opposing the protrusion-part mold 63 contacts with the protrusion-part mold 63 . At this time, almost all the air between the connection-member-part mold 64 and the tread rubber 70 flows in the direction of the block-part mold 61 because the connection-member-part mold 64 is connected to the block-part mold 61 . Therefore, when the tread rubber 70 in the connection-member-part mold 64 contacts with the connection-member-part mold 64 , no air is left between the connection-member-part mold 64 and the tread rubber 70 . In addition, almost all the tread rubber 70 located in and opposing the connection-member-part mold 64 directly contacts with the connection-member-part mold 64 . Because the vent hole 65 is formed in the block-part mold 61 , the air present between the block-part mold 61 and the tread rubber 70 is discharged to the outside of the mold 60 through the vent hole 65 . By continuously pressing the tread rubber 70 , therefore, the air present between the block-part mold 61 and the tread rubber 70 is discharged to the outside of the mold 60 . Accordingly, when the tread rubber 70 in the block-part mold 61 contacts the block-part mold 61 , no air is left between the block-part mold 61 and the tread rubber 70 and almost all the tread rubber 70 located in and opposing the block-part mold 61 directly contacts with the block-part mold 61 . In this manner, the pneumatic tire 1 includes the protrusion 30 provided in each of the grooves 20 of the tread area 10 and formed so that its height from the groove bottom 24 is changed. The convex portion 31 of the protrusion 30 and the block 15 are connected to each other by the connection member 40 . The connection member 40 is formed so that its height from the groove bottom 24 in the block-side end 42 is larger than that in the convex-side end 41 . During manufacture of the pneumatic tire 1 , the mold 60 for molding the tread area 10 is disposed outward of the tread rubber 70 in the tire radial direction, and the pressure is applied to the tread rubber 70 from inward to outward of the tread rubber 70 in the tire radial direction, thereby vulcanization-molding the tread area 10 . During the vulcanization molding, the air present between the tread rubber 70 and the mold 60 flows into the portion located further outward in the tire radial direction. Accordingly, the air present between the tread rubber 70 and the protrusion-part mold 63 flows into the portion of the protrusion-part mold 63 , which portion corresponds to the convex portion 31 of the protrusion 30 . Furthermore, the height of the connection member 40 from the groove bottom 24 is larger than that of the convex portion 31 . Therefore, the air present between the tread rubber 70 and the mold 60 flows from the protrusion-part mold 63 for molding the convex portion 31 to the connection-member-part mold 64 . Moreover, because of the connection of the connection-member-part mold 64 to the block-part mold 61 , the air between the connection-member-part mold 64 and the tread rubber 70 flows from the connection-member-part mold 64 to the block-part mold 61 . Furthermore, the vent hole 65 is formed in the block-part mold 61 . With these features, during the vulcanization molding, the air between the protrusion-part mold 63 and the tread rubber 70 moves in the direction of the block-part mold 61 through the connection-member-part mold 64 , and is discharged from the vent hole 65 to the outside of the mold 60 . Therefore, the tread rubber 70 easily flows into the protrusion-part mold 63 . Consequently, even if the height of the protrusion 30 is made larger or the volume thereof is increased to ensure the capability of preventing the stone 50 from being trapped within the groove 20 when the stone 50 enters the groove 20 , that is, to ensure anti-stone-trapping capability, the tread rubber 70 can more reliably flow into the mold 60 for forming the protrusion 30 during manufacture of the pneumatic tire 1 . Therefore, it is possible to reduce failure in manufacture or so-called “occurrence of bare”, and to more surly obtain the targeted shape of the protrusion 30 . Consequently, the occurrence of bare can be reduced while the anti-stone-trapping capability is ensured. The height of the connection member 40 from the groove bottom 24 becomes gradually larger from the convex-side end 41 toward the block-side end 42 . Therefore, when the pneumatic tire 1 is manufactured, the air between the protrusion-part mold 63 of the mold 60 and the tread rubber 70 and flowing from the protrusion-part mold 63 to the block-part mold 61 through the connection-member-part mold 64 more easily flows in the direction of the portion corresponding to the block-side end 42 which is the portion located outward in the tire radial direction. With this feature, the tread rubber 70 can more reliably flow into the protrusion-part mold 63 , which makes it possible to more surely obtain the targeted shape of the protrusion 30 . Consequently, the occurrence of bare can be more reliably reduced. When the connection member 40 is formed so that its inclination angle θ with respect to the groove bottom 24 from the convex-side end 41 over the block-side end 42 is in the range from 3 degrees to 45 degrees, the occurrence of bare can be reduced while the anti-stone-trapping capability is more reliably ensured. More specifically, the inclination angle θ with respect to the groove bottom 24 from the convex-side end 41 over the block-side end 42 is set to 3 degrees or more, and it is thereby possible to prevent a difference in the tire radial direction between the convex portion 31 and the block-side end 42 from becoming too small. Therefore, because the block-part mold 61 side of the connection-member-part mold 64 is formed more surely outward in the tire radial direction than the protrusion-part mold 63 side thereof, the air flowing from between the protrusion-part mold 63 of the mold 60 and the tread rubber 70 to the direction of the block-part mold 61 through the connection-member-part mold 64 can more reliably flow in this direction during the vulcanization molding. With this feature, the tread rubber 70 can more surely flow into the protrusion-part mold 63 , thus more reliably obtaining the targeted shape of the protrusion 30 . The inclination angle θ with respect to the groove bottom 24 from the convex-side end 41 over the block-side end 42 is set to 45 degrees or less. It is thereby possible to prevent the rigidity of the connection member 40 from becoming too high, and associated with this, the rigidity of the protrusion 30 connected to the connection member 40 can be prevented from being too high. With this feature, the protrusion 30 is formed to be elastic, and this allows the ejection action on the stone 50 by the elastic force of the protrusion 30 to be ensured, and the anti-stone-trapping capability can thereby be ensured. Therefore, by forming the connection member 40 so that its inclination angle θ with respect to the groove bottom 24 is in the range from 3 degrees to 45 degrees, the targeted shape of the protrusion 30 can be more surely obtained, and the stone 50 , which has entered the groove 20 , can be more reliably ejected. Consequently, the occurrence of bare can be reduced while the anti-stone-trapping capability is more surely ensured. When the connection member 40 is formed so that the relation between the height h 1 of the convex portion 31 and the width W of the connection member 40 is in the range of 0.05h 1 ≦W≦1.0h 1 , the occurrence of bare can be reduced while the anti-stone-trapping capability is more reliably ensured. More specifically, by setting the width W of the connection member 40 to be 0.05 times or more of the height h 1 of the convex portion 31 , the width of the connection member 40 can be increased to a predetermined width or more, and associated with this, the width of the connection-member-part mold 64 can be made to a predetermined width or more. This allows the air to easily flow between the connection-member-part mold 64 and the tread rubber 70 during the vulcanization molding. The air can, therefore, easily flow from the protrusion-part mold 63 to the block-part mold 61 during the vulcanization molding, and hence, the tread rubber 70 can easily flow into the protrusion-part mold 63 . It is thereby possible to more surely obtain the targeted shape of the protrusion 30 . By setting the width W of the connection member 40 to be 1.0 time or less of the height h 1 of the convex portion 31 , the rigidity of the connection member 40 can be prevented from becoming too high, and associated with this, the rigidity of the protrusion 30 connected with the connection member 40 can be prevented from becoming too high. By so setting, the protrusion 30 can be formed to be elastic, and hence, the ejection action on the stone 50 by the elastic force of the protrusion 30 can be ensured, and the anti-stone-trapping capability can thereby be ensured. Therefore, by forming the connection member 40 so that the relation between the height h 1 of the convex portion 31 and the width W of the connection member 40 is in the range of 0.05h 1 ≦W≦1.0h 1 , the targeted shape of the protrusion 30 can surely be obtained, and the stone 50 , which has entered the groove 20 , can thereby be more reliably ejected therefrom. Consequently, the occurrence of bare can be reduced while the anti-stone-trapping capability is more surely ensured. FIG. 11 is a detailed cross-section of a pneumatic tire according to another embodiment of the present invention. FIG. 12 is a cross-section taken along the line D-D of FIG. 11 . In the preceding embodiment, one convex portion 31 is formed in one protrusion 30 , but a plurality of convex portions 31 can be formed in one protrusion 30 . For example, as shown in FIG. 11 and FIG. 12 , in the protrusion 30 , concavity and convexity may be repeated in the tire radial direction and a plurality of convex portions 31 which are convex outward in the tire radial direction are obtained. In this case, a plurality of connection members 40 may be formed so as to connect a plurality of the convex portions 31 to blocks 15 , respectively. The convex portions 31 are formed on the protrusion 30 , which allows improvement of the anti-stone-trapping capability. In addition, by connecting the connection members 40 to the convex portions 31 , the targeted shape can be more surely obtained even if the convex portions 31 are formed in the protrusion 30 . Consequently, the occurrence of bare can be reduced while the anti-stone-trapping capability is more reliably ensured. Although only one connection member 40 is connected to one convex portion 31 , a plurality of connection members 40 can be connected to one convex portion 31 . For example, the connection member 40 is provided from one convex portion 31 toward both of opposite groove walls 23 , and the connection members 40 can be connected to the respective groove walls 23 , i.e. the respective blocks 15 . In other words, the two blocks 15 , which include the opposite groove walls 23 , and the convex portion 31 of the protrusion 30 , which is located between these blocks 15 , can be connected to each other by the two connection members 40 . With this structure, when the vulcanization molding is carried out, the air in the protrusion-part mold 63 is allowed to flow in the directions of two block-part molds 61 through two connection-member-part molds 64 . Therefore, the tread rubber 70 can more surely flow into the protrusion-part mold 63 . Consequently, the occurrence of bare can be more reliably reduced. Although the height of the connection member 40 is getting larger from the convex-side end 41 toward the block-side end 42 , the height of the connection member 40 from the groove bottom 24 can be changed step by step. Even if the height of the connection member 40 does not gradually change, the air between the protrusion-part mold 63 of the mold 60 and the tread rubber 70 can flow from the connection member 40 to the block-part mold 61 if the height of the connection member 40 from the groove bottom 24 is larger than that of the convex portion 31 from the groove bottom 24 . This allows the tread rubber 70 to more surely flow into the protrusion-part mold 63 . Consequently, the occurrence of bare can be more surely reduced. Even if the height of the connection member 40 is not gradually changed, the connection member 40 is preferably formed so that its inclination angle θ with respect to the groove bottom 24 from the convex-side end 41 over the block-side end 42 is in the range from 3 degrees to 45 degrees. More specifically, even if the height of the connection member 40 is not gradually changed, the connection member 40 is preferably formed so that its inclination angle θ with respect to the groove bottom 24 is in the range from 3 degrees to 45 degrees, the inclination angle being from a portion of the convex-side end 41 located in its outside end in the tire radial direction to a portion of the block-side end 42 located in its outside end in the tire radial direction. By forming the connection member 40 so that the relation between the convex-side end 41 and the block-side end 42 falls within the range, the occurrence of bare can be reduced while the anti-stone-trapping capability is more reliably ensured. The width of the connection member 40 in the direction in which the groove 20 is formed is almost equivalent to the width of the convex portion 31 of the protrusion 30 in the same direction as above. However, the width of the connection member 40 can be set different from the width of the convex portion 31 . Widths of the connection member 40 and the convex portion 31 can be either equal to or different from each other. If both of them are connected to each other, the air can flow from the protrusion-part mold 63 of the mold 60 to the connection-member-part mold 64 during the vulcanization molding. In addition, the tread rubber 70 can more reliably flow into the protrusion-part mold 63 . Consequently, the occurrence of bare can be more surely reduced. As one example of the pneumatic tire 1 , the pneumatic tire 1 including the block type tread has been explained above. However, the pneumatic tire 1 to which the present invention is applied can be the pneumatic tire 1 including any one of the ribbed tread, the ribbed-lug tread, and the like other than the block type tread. Even if the pneumatic tire 1 is other than the pneumatic tire 1 including the block type tread, it suffices that the connection member 40 is formed such that its height from the groove bottom 24 is larger than the height of the convex portion 31 of the protrusion 30 from the groove bottom 24 . In addition, it suffices to form such a connection member 40 in the groove 20 , in which it is connected to both the convex portion 31 and the land, similarly to the pneumatic tire 1 including the block type tread. In this manner, if the pneumatic tire 1 is the one that the protrusion 30 and the connection member 40 made in the above manner can be formed in the groove 20 , a desired pattern can be used for the pattern shape of the tread. Even if the pneumatic tire 1 has any pattern shape, the occurrence of bare can be reduced while the anti-stone-trapping capability is ensured by forming the protrusion 30 and the connection member 40 in the groove 20 in the above manner. Performance evaluation tests conducted on the conventional pneumatic tire and the pneumatic tire 1 according to the embodiments of the present invention are explained below. The performance evaluation test was conducted on two items, i.e., anti-bare capability and the anti-stone-trapping capability. The performance evaluation test was conducted using the pneumatic tire 1 of 11R22.5 size. Each test item was evaluated as follows. The anti-bare capability was evaluated by vulcanization-molding 20 pieces of pneumatic tires 1 and by determining how many pieces out of the 20 pneumatic tires 1 bare occurred to. It is assumed that if bare occurred to fewer pneumatic tires 1 , then the pneumatic tires 1 are determined more excellent in the anti-bare capability. It is also assumed that if bare occurred to two pieces or less out of the 20 pieces of the pneumatic tires 1 , then the pneumatic tires 1 are determined effective in the anti-bare capability. The anti-stone-trapping capability was evaluated by attaching each of the pneumatic tires 1 to be tested assembled with a rim to a vehicle, performing a test run of the vehicle on a fixed course, and determining how many stones were trapped within the grooves 20 after the test run. The number of stones were evaluated using an index in which the number of stones in comparative example 1 explained later was set to 100. It is assumed that a higher index indicates more excellence in the anti-stone-trapping capability. It is also assumed that the anti-stone-trapping capability is ensured if the index is up to 95. The pneumatic tires 1 to be tested include those according to seven examples (hereinafter, “examples 1 to 7”) of the present invention, and those according to two comparative examples (hereinafter, “comparative examples 1 and 2”). These pneumatic tires 1 were tested in the above method. Each of the pneumatic tires 1 according to the examples 1 to 7 and the comparative examples 1 and 2 includes zigzag-shaped longitudinal grooves 21 . In addition, a plurality of protrusions 30 are formed in each longitudinal groove 21 . Each of the protrusion 30 has a height from the groove bottom 24 of four millimeters, a width in the groove width direction of 2.5 millimeters, and a length in the direction, in which the longitudinal groove 21 is formed, of 40 millimeters. Among the pneumatic tires 1 including the protrusions 30 thus formed and to be tested, the pneumatic tire 1 according to the comparative example 1 includes no connection member 40 . The pneumatic tire 1 according to comparative example 2 includes the connection member 40 . However, the relation between the height h 1 of the convex portion 31 from the groove bottom 24 and the height h 2 of the connection member 40 from the groove bottom 24 is h 2 =h 1 . The inclination angle of the outward surface 43 of the connection member 40 with respect to the groove bottom 24 is zero degree. In addition, the ratio (W/h 1 ) of the width W of the connection member 40 to the height h 1 of the convex portion 31 is 0.15. On the other hand, according to the examples 1 to 7, the relation between the height h 1 of the convex portion 31 from the groove bottom 24 and the height h 2 of the connection member 40 from the groove bottom 24 is h 2 >h 1 . Furthermore, in the example 1, the inclination angle of the outward surface 43 of the connection member 40 with respect to the groove bottom 24 is two degrees, and the ratio (W/h 1 ) of the width W of the connection member 40 to the height h 1 of the convex portion 31 is 0.5. Likewise, in the example 2, the inclination angle is four degrees and the ratio (W/h 1 ) is 0.5. In the example 3, the inclination angle is four degrees and the ratio (W/h 1 ) is 0.05. In the example 4, the inclination angle is 15 degrees and the ratio (W/h 1 ) is 0.5. In the invention 5 , the inclination angle is 40 degrees and the ratio (W/h 1 ) is 0.5. In the example 6, the inclination angle is 50 degrees and the ratio (W/h 1 ) is 0.2. In the example 7, the inclination angle is 4 degrees and the ratio (W/h 1 ) is 1.0. The evaluation tests were conducted on the pneumatic tires 1 according to the comparative example 1 and the comparative example 2 and according to the examples 1 to 7 using the method. Test results are shown in Table 1 to Table 2. Table 1 depicts the results of the evaluation tests conducted on the pneumatic tires 1 according to the comparative example 1 and the comparative example 2 and the pneumatic tires 1 according to the examples 1 to 3. Table 2 depicts the results of the evaluation tests conducted on the pneumatic tires 1 according to the examples 4 to 7. TABLE 1 Com- Com- parative parative Example 1 Example 2 Example 1 Example 2 Example 3 Connection Not h2 = h1 h2 > h1 h2 > h1 h2 > h1 Member provided Inclination — 0 2 4 4 angle (°) Width of — 0.15 0.5 0.5 0.05 Connection Member (W/h1) Number of 18 9 2 0 1 occurrences of bare (/20 pieces) Anti-stone- 100 100 100 100 100 trapping capability TABLE 2 Example 4 Example 5 Example 6 Example 7 Connection Member h2 > h1 h2 > h1 h2 > h1 h2 > h1 Inclination angle (°) 15 40 50 4 Width of 0.5 0.5 0.2 1.0 Connection Member (W/h1) Number of 0 0 0 0 occurrences of bare (/20 pieces) Anti-stone-trapping 100 100 97 96 capability As clear from the test results shown in Tables 1 and 2, if the connection member 40 is not formed, the air between the tread rubber 70 and the protrusion-part mold 63 in the mold 60 could not be easily discharged during the vulcanization molding, and the tread rubber 70 does not easily flow into the protrusion-part mold 63 . Due to this, bare easily occurs (see comparative example 1). If the connection member 40 is formed but the height h 2 of the connection member 40 from the groove bottom 24 is equal to the height h 1 of the convex portion 31 of the protrusion 30 , the air between the tread rubber 70 and the protrusion-part mold 63 in the mold 60 does not easily flow in the direction of the connection-member-part mold 64 during the vulcanization molding of the pneumatic tire 1 . Easiness of flow of the tread rubber 70 into the protrusion-part mold 63 is not, therefore, much improved. As a result, it is difficult to reduce the occurrence of bare (see comparative example 2). On the other hand, according to the examples 1 to 7, the connection member 40 is formed so that the relation between the height h 2 of the connection member 40 from the groove bottom 24 and the height h 1 of the convex portion 31 of the protrusion 30 is h 2 >h 1 . The connection member 40 is connected to the protrusion 30 . Therefore, the air between the tread rubber 70 and the protrusion-part mold 63 in the mold 60 can easily flow in the direction of the connection-member-part mold 64 during the vulcanization molding of the pneumatic tire 1 . Easiness of flow of the tread rubber 70 into the protrusion-part mold 63 can be thereby improved, thus allowing reduction in the occurrence of bare. Because of the reduction in the occurrence of bare, the targeted shape of the protrusion 30 can be obtained. It is, therefore, possible to ensure the anti-stone-trapping capability by providing the protrusions 30 in the groove 20 . According to one aspect of the present invention, the occurrence of bare can be reduced while ensuring the anti-stone-trapping capability. Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.

A pneumatic tire includes a plurality of protrusions on a bottom of each of the grooves. The height of the protrusion is variable in a profile of the protrusion in a circumference direction of the pneumatic. The protrusion has at least one peak portion that protrudes away from a center of the pneumatic tire. The pneumatic tire further includes a connection member between the protrusion and an adjacent one of the lands, the connection member having a first end toward the land and a second end toward the peak portion, a height of the first end from the bottom of the groove being larger than that of the second end.

FIELD OF THE INVENTION The present invention relates generally to apparatus for the recovery of silver as a free metal from depleted photographic processing liquids and the like. BACKGROUND OF THE INVENTION As is well known, silver is a basic component of many photographic processing liquids. In the development of most photographic films, papers and the like, the concentration of silver is automatically maintained within a predetermined range by specialized equipment. Excess silver-bearing liquid is discharged by such equipment into waste holding tanks for later disposal. Most sewage treatment agencies regard silver suspended in photographic fixers and other liquids as a hazardous material. Thus, silver-bearing liquids must be treated to remove substantially all of their silver before the liquid may be deposited into conventional sewage conduits. The concentration of silver permitted to remain in the disposed liquid varies from locality to locality, but generally must fall below 5 parts per million. Many agencies, however, require a lower concentration of silver in a liquid destined for sewer disposal. Systems of varied design have been proposed for the recovery of silver from photographic processing liquids and the like. In each of these systems, the silver-bearing liquid is fed through one or more silver recovery cartridges filled with a reaction medium such as a mass of iron wool, iron wire screen or iron particles. Under standard conditions, the silver ions in the liquid undergo exchange reactions with the ferrous ions of the reaction medium. The silver is, thus, precipitated from the liquid in the form of a thin coating upon the steel wool and a dense sludge that accumulates at the bottom of the silver recovery cartridge. A principal disadvantage of the silver recovery systems currently available is that the waste holding tank is often remotely positioned from its associated silver recovery cartridge(s). The relatively long hoses utilized to connect the elements together, then, must be carefully handled to avoid their kinking or severing which may result in uncontained spills of silver-bearing liquid. The remote positioning of the holding tank from the silver recovery cartridge(s) also requires excessive floor space and presents obvious difficulties when movement of the system is required. A need, therefore, exists for a compact silver recovery system that may be readily transported and is capable of safely containing spills that may occur due to operator carelessness, etc. SUMMARY OF THE INVENTION In light of the deficiencies presented by the prior art silver recovery systems, it is a principal object of the present invention to provide a system for recovering silver from such diverse liquids as the wash waters and fixers employed in the development of photographic films, papers and the like that is lightweight and compact in size for enhanced mobility in confined work environments. It is another object of the invention to provide a silver recovery system having means for containing silver-bearing liquid in the event that such is inadvertently spilled during system use. It is an additional object of the invention to provide a silver recovery system wherein a positive hydrostatic head is maintained between a pair of silver recovery cartridges of the ion exchange type to prevent liquid flow blockages from forming in the cartridges themselves and their connecting liquid transfer conduit. It is an object of the invention to provide improved elements and arrangements thereof in a silver recovery system for the purposes described which is relatively inexpensive, dependable and fully effective in accomplishing its intended purposes. Briefly, the silver recovery system in accordance with this invention achieves the desired objects by featuring a holding tank for receiving silver-bearing liquid having a removable cover. The cover includes a pair of vertically offset platform portions, each for receiving one of a pair of serially-connected silver recovery cartridges. Each cartridge contains a source of ions, above silver in electromotive force series, for reacting with silver-bearing liquid so that silver is recovered therein. A pump is secured to the cover for delivering silver-bearing liquid from the holding tank to each of the cartridges in succession. Should silver-bearing liquid be inadvertently spilled, the cover further includes a containment wall around its periphery for confining the spill. As a back-up measure, an overflow tank is positioned beneath the holding tank for receiving any silver-bearing liquid that may flow over the containment wall. The foregoing and other objects, features and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be more readily described with reference to the accompanying drawings, in which: FIG. 1 is a perspective view of a silver recovery system in accordance with the present invention, exploded to show details thereof. FIG. 2 is a transverse cross-sectional view of the silver recovery system. FIG. 3 is an electric circuit diagram for the silver recovery system. FIG. 3A is an electric circuit diagram illustrating a switch for actuating an auxiliary alarm which may be employed in conjunction with the silver recovery system. Similar reference characters denote corresponding features consistently throughout the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a silver recovery system in accordance with the present invention is shown generally at 10. As shown, the system 10 preferably includes an open-topped holding tank 12 having a split-level cover 14 adapted to carry a pair of silver recovery cartridges 16 and 18. Positioned directly between the cartridges 16 and 18 is a control unit 20 principally for delivering silver-bearing liquid contained in the holding tank 12 to the cartridges 16 and 18 in a regulated fashion. For ready transport over the ground surface, the holding tank 12 is positioned within a reinforced overflow tank 22 having casters 24 extending from the bottom thereof. In the preferred embodiment of the invention, the holding tank 12 is provided with a box-like form being substantially rectangular in both horizontal and vertical cross section. The holding tank 12 thus includes a planar bottom wall 26 having four generally planar side walls 28 extending upwardly therefrom so as to define an open container having a capacity of approximately 12 gallons. For added strength, projecting outwardly from the side walls 28, about the open top of the holding tank 12, is a peripheral flange 30 having an inverted L-shape. The holding tank 12 is formed of any material suitable for indefinitely containing a silver-bearing liquid of the type derived from photographic processes. In this regard, the holding tank 12 is preferably integrally molded of a thermoplastic composition such as polypropylene. It should, of course, be understood that the holding tank 12 may be fabricated of any other corrosion resistant material of suitable strength and durability. The open top of the holding tank 12 is selectively closed by positioning the split-level cover 14 upon the peripheral flange 30. As shown, the cover 14 preferably includes a downwardly-projecting peripheral rim 32 adapted to closely engage the peripheral flange 30 of the holding tank 12 so as to prevent the relative lateral movement thereof. To selectively lock the cover 14 upon the holding tank 12, the peripheral rim 32 is provided with a plurality of inwardly-projecting fingers 34 positioned to frictionally engage the free end of the peripheral flange 30. As the cover 14, like the holding tank 12, is preferably integrally molded from a corrosion resistant and somewhat resilient material like polypropylene, the rim 32 may be slightly deformed to disengage the fingers 34 from the flange 30 so as to permit the cover 14 to be removed from the holding tank 12 when desired. The cover 14 preferably includes: a base portion 36, an elevated platform portion 38 disposed above the base portion 36, and a recessed platform portion 40 disposed below the base portion 36. As shown, each of the platform portions 38 and 40 is circular in outline and is adapted to closely receive one of the silver recovery cartridges 16 and 18 therein. The elevated platform portion 38 is provided with a raised, circumferential ring 42 about its upper surface adapted to abut the sides of silver recovery cartridge 16 so as to prevent the lateral movement thereof during transport of the system 10. The side walls 44 of the recessed platform portion 40 serve as a similar abutment surface for the silver recovery cartridge 18. For drainage of small volumes of silver-bearing liquid inadvertently spilled from the silver recovery cartridges 16 and 18 during their replacement, testing, etc., a relatively small drainage hole 46 is provided in each of the platform portions 38 and 40. With direct access to the open top of the holding tank 12 provided by each drainage hole 46, spilled silver-bearing liquid is free to flow under the influence of gravity directly into the holding tank 12 where it is collected and stored for later processing. To contain relatively large amounts of silver-bearing liquid inadvertently spilled upon the cover 14, the periphery of the base portion 36 is upwardly formed so as to provide a low containment wall 48. Silver-bearing liquid collected upon the base portion 36 within the confines of the containment wall 48 may be drained into the holding tank 12 through one of a pair of relatively large openings 50 and 52 in opposing corners of the base portion 36. During normal use, however, the openings 50 and 52, having threads about their respective peripheries, are closed by suitably threaded plugs 54 and 56. In the event that spilled silver-bearing liquid runs over the containment wall 48 of the cover 14, the overflow tank 22 is preferably positioned to catch the excess before it can pass in an uncontrolled manner onto the floor or other supporting surface for the system 10 where cleanup may be difficult. As shown, then, the preferred overflow tank 22 has a box-like shape adapted to partially receive the holding tank 12 within its open top. Because the preferred overflow tank 22 is relatively larger than the holding tank 12, approximately 2 gallons of overflowed silver-bearing liquid may be captured therein during an overflow situation. Of course, the storage capacity of the overflow tank 22 is merely exemplary as the volume of both the overflow tank 22 and the holding tank 12 may be varied as desired to suit the needs of a particular user. Like the holding tank 12, the overflow tank 22 includes a bottom wall 58 having four side walls 60 extending upwardly therefrom. As shown, the bottom wall 58 and side walls 60 are dimensioned so as to form an opening in the top of the overflow tank 22 having of a size somewhat larger than that of the cover 14. Thus, overflowing silver-bearing liquid may pour directly from the cover 14 into the overflow tank 22. Although any suitable material may be employed, the preferred overflow tank 22 is molded from polypropylene. For increased rigidity, however, the bottom and side walls 58 and 60 are provided with a plurality of integral recesses or grooves 62 extending across their respective surfaces. Caster mounting recesses 64 are provided in the bottom wall 58 alone for receiving the mounting platforms 66 of the casters 24 with a snap-type fit. The base portion 36 of the cover 14 serves as a mounting surface and support for the control unit 20. As shown, the control unit 20 is provided with a two-piece housing 68 adapted for positioning between the elevated platform portion 38 and recessed platform portion 40 of the cover 14. The preferred housing 68 includes a base plate 70 for positioning directly upon the cover 14 and a lid 72 secured to the base plate 70 by threaded fasteners 74. The preferred lid 72 is provided with opposed front and back walls 76 and 78 integrally connected together by top wall 80 as well as side walls 82 having a concave shape so as to accommodate the silver recovery cartridges 16 and 18 with a minimal distance separating the silver recovery cartridges from one another. For lateral stability of the housing 68, the bottom of the lid 72 is preferably provided with a peripheral flange 84 extending horizontally therefrom. As shown, at opposite ends of each of the concave side walls 82, the flange 84 widens somewhat to provide a fastening surface 86 through which a threaded fastener 88 may be easily passed to secure the control unit 20 to the cover 14. The portion of the flange 84 extending from the front wall 76, on the other hand, has been adapted for positioning within a cooperating slot or notch 90 (see FIG. 2) molded into the containment wall 48 to further secure the control unit 20 to the cover 14. Mounted upon the base plate 70 is a positive displacement, bellows-type metering pump 92 driven by an electric motor 94. A metering pump suitable for use in the instant invention is model no. 16200-011 made by Gorman-Rupp Industries of Bellville, Ohio. Such a pump is capable of variably delivering from 7.5 to 75 cubic centimeters of silver-bearing liquid per minute to the silver recovery cartridges 16 and 18. Of course, pumps of the type described also have the advantage that their rate of liquid discharge can be selectively adjusted between the pump limits, thus permitting the residence time of the silver-bearing liquid in the cartridges 16 and 18 to be optimized. A series of tubular conduits place the silver recovery cartridges 16 and 18 in fluid communication with the typically spent silver-bearing liquid contained in the holding tank 12 through the metering pump 92. In this regard, a suction conduit 96 connects the inlet side of the metering pump 92 with the holding tank 12. A discharge conduit 98, on the other hand, connects the outlet side of the metering pump 92 with the inlet conduit 100 for the silver recovery cartridge 16. A transfer conduit 102 serially connects the silver recovery cartridges 16 and 18 together by joining the outlet of silver recovery cartridge 16 and the inlet of silver recovery cartridge 18. A disposal conduit 104, connected to the outlet of silver recovery cartridge 18, permits the discharge of the processed silver-bearing liquid into a sewer drain or storage vessel (not shown). Particulate matter suspended in the silver-bearing liquid can damage the metering pump 92. For this reason, a filter screen 106 of suitable mesh is secured to the free end of the suction conduit 96 suspended near the bottom of the holding tank 12. In the event, however, that precipitated silver sludge or other matter accumulates upstream of the metering pump 92 to the point where liquid flow through the system is blocked, a pressure relief valve 108 is in fluid communication with the discharge conduit 98. Thus, if the pressure in the discharge conduit 98 reaches a predetermined level, the relief valve 108 opens and diverts silver-bearing liquid into an associated relief conduit 110 which opens into the holding tank 12. Each of the silver recovery cartridges 16 and 18 is of conventional construction and preferably contains a reaction medium such as a mass of iron wool, iron wire screen or iron particles for precipitating silver from the liquid being processed. When filled with silver bearing liquid, the silver recovery cartridges 16 and 18, which may have an individual capacity of several gallons, become relatively heavy. The physical handling of the silver recovery cartridges 16 and 18 is minimized, however, by the provision of casters 24 to bottom wall 58 of the overflow tank 22 which bears the load of the silver recovery cartridges. A first float-actuated switch 112 regulates the operation of the metering pump 92. As shown, the switch 112 is suspended by a conduit 114 from the cover 14 into the holding tank 12. The conduit 114 houses the electrical leads 116 from the switch 112 isolating such from the silver-bearing liquid in the holding tank thereby preventing the electrical leads from posing a shock hazard. As shown schematically in FIG. 3, the float-actuated switch 112 is connected in electrical series with the metering pump 92 and fuse 118 to a conventional plug 119 adapted for connection to an AC power source. When the liquid in the holding tank 12 rises to a predetermined level so as to close the float-actuated switch 112, the motor 94 is activated to deliver liquid from the holding tank 12 by means of pump 92 into and through the serially connected silver recovery cartridges 16 and 18 at a controlled rate. Subsequently, the motor 94 and metering pump 92 are de-energized when the level of the liquid in the holding tank 12 has been lowered to its original position. Of course, by activating the metering pump 92 only when the silver bearing liquid in the holding tank 12 has reached a predetermined level and, then, not deactivating the pump until a lower level has been reached, a minimum volume of liquid will be pumped through the silver recovery cartridges 16 and 18 each time the metering pump 92 is activated. This volume may be so chosen that in each operating cycle of the metering pump 92, a sufficient volume of liquid is pumped through the silver recovery cartridges 16 and 18 to prevent flow-restricting gels or precipitates from accumulating in any of the tubular conduits 96, 98, 100, 102 and 104. A total-elapsed-time timer 120 is electrically connected in parallel with the metering pump 92 and provides a visual reference to the operator of how long the metering pump 92 has been actuated in each operating cycle of the timer. Since the useful life of the reaction medium in the silver recovery cartridges 16 and 18 has been found to remain relatively constant from cycle to cycle, the time indicated by timer 120 suggests when the silver recovery cartridges 16 and 18 have reached the end of their useful lives. With this data readily available, the operator may replace the silver recovery cartridges 16 and 18 without guesswork. Of course, it is important that the silver recovery cartridges 16 and 18 be replaced before the reaction medium therein is completely consumed by ion exchange reactions so as to prevent the inadvertent discharge of unprocessed silver-bearing liquid into the sewer drain. An auxiliary overflow alarm (not shown) may be employed to alert an operator that the holding tank 12 has been filled with an excessive amount of silver-bearing liquid due to a malfunction, conduit blockage, etc. Although not part of the invention, it is contemplated that the overflow alarm would include, in electrical series, an independent power source, such as a battery, and a buzzer, bell or flashing light. Through suitable electrical leads, the overflow alarm would be operatively connected through a conventional electrical jack 124 on the front wall 76 of lid 72. The jack 124 is, in turn, operatively connected to a second float-actuated switch 122 suspended from the cover 14 of the holding tank 12 to sound whenever the level of liquid in the holding tank reaches the level of float-actuated switch 122 positioned at a height somewhat above that of the first float-actuated switch 112. Preferably, the alarm will remain energized until the level of the liquid in the holding tank 12 drops below the level of the second float-actuated switch 122. Should an operator be unable to attend to the system 10 in the event of an overflow, means are provided for conveying the excess silver bearing liquid to a remote storage tank without the danger of an uncontrollable spill. Thus, with reference back to FIG. 1, an overflow fitting may be seen to be secured to the base portion 36 of the cover 14. As shown, the fitting 124 comprises a conventional threaded ell to which may be secured an appropriate conduit to a location where excess liquid can be safely disposed of or held for later processing. For operation of the system 10, the plug 119 is connected to a suitable power source and master switch 126 on the front wall 76 of lid 72 is manually closed. Assuming that an adequate volume of silver bearing liquid is present in holding tank 12, switch 112 will be closed thus energizing the motor 94 and its associated pump 92. By means of pump 92 silver bearing liquid is delivered to the silver recovery cartridges 16 and 18 at a predetermined rate. Being first in the processing series, silver recovery cartridge 16 removes essentially all of the silver from the silver-bearing liquid. If, however, the reaction medium in silver recovery cartridge 16 was exhausted resulting in the discharge of unprocessed silver bearing liquid into transfer conduit 102, silver recovery cartridge 18, acting as a system back-up, would remove it from the liquid prior to discharge into disposal conduit 104. Nevertheless, by monitoring the elapsed processing time with the timer 120, inadvertent discharge of unprocessed silver-bearing liquid from cartridge 16 can be avoided. Virtually total recovery of the silver is automatically attained through proper operation of the system 10. Post processing levels of silver in the treated liquid below 0.5 parts per million are typically reached. Such silver concentrations are low enough to comply with the most stringent pollution control regulations known. While the invention has been described with a high degree of particularity, it will be appreciated by those skilled in the art that numerous modifications and substitutions may be made thereto. For example, the float-actuated switches for controlling the operation of the pump motor 94 described hereinabove have a number of well known equivalents. Thus, the silver-bearing liquid may be employed as an electrical conductor to bridge a pair of electrical contacts such as graphite rods suspended a fixed distance beneath the cover to close the motor power circuit. Therefore, it is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.

A system for recovering silver as a free metal from silver-bearing liquid. The silver recovery system includes a holding tank for receiving silver bearing liquid having an opening in its top and a removable cover for closing the opening. A pair of silver recovery cartridges are carried by the cover and are connected together for serial flow. Each silver recovery cartridge contains a source of ions above silver in electromotive force series for reacting with silver-bearing liquid so that silver is recovered therein. A pump is secured to the cover for delivering silver-bearing liquid from the holding tank to the silver recovery cartridges.

CROSS REFERENCE TO RELATED APPLICATION This is a continuation of application Ser. No. 08/413,949, filed on Mar. 30, 1995, now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 08/197,845 filed Feb. 17, 1994, now U.S. Pat. No. 5,404,062. FIELD OF THE INVENTION The present invention relates to levitation devices and methods and more particularly to the levitation or suspension of a permanent magnet in a magnetic field produced by another magnet (either permanent or electromagnetic) using no mechanical restraints or supports. BACKGROUND OF THE INVENTION Magnets, both permanent magnets and electromagnets, find a wide variety of uses, both practical and as entertainment devices. The poles of magnets have been named the north pole and the south pole, the north pole being the one that points northward in the Earth's magnetic field, i.e., the magnetic north-seeking pole. It is, of course, well known that like poles, i.e., two north poles, repel one another and unlike poles, i.e., a north pole and a south pole, attract one another. This phenomenon has been used to levitate one magnet above another and offers the possibility of substantially reduced friction. Magnetic levitation of trains, for example, is one practical application of the phenomenon. However, in such a levitation application, highly sophisticated control devices are required for controlling the magnetic fields of electromagnets to overcome the inherent instabilities of the repulsion forces of two like magnetic poles. In a simple levitation system wherein one pole of a first permanent magnet is attempted to be suspended above a like pole of a second permanent magnet, the inherent instability of such a system results in the flipping over of the first magnet so that the unlike poles attract and are brought together into a stable configuration. A number of simple levitation systems have been devised which employ specially configured permanent magnet arrangements intended to minimize the instability associated with magnetic levitation. In U.S. Pat. No. 2,323,837 to Neal, for example, there is disclosed a magnetic system having a base magnet comprising a circular disk in which a first plurality of cylindrical magnets is disposed in a circular array about the axis of the circular disk. An upper magnet member comprises a spherical segment in which a second plurality of cylindrical magnets is disposed in a circular array of smaller diameter than the diameter of the circular array of the base magnet. The first plurality of magnets is disposed with like (north) poles and longitudinal axes directed vertically upwardly or inclined slightly toward the axis of the circular disk. The second plurality of magnets is disposed with like (north) poles and longitudinal axes directed vertically downwardly or inclined at the same inclination as the first plurality of magnets. This arrangement of the base magnet is said to produce an inverted magnetic field cone which embraces the smaller diameter magnet field of like polarity of the upper magnet and thereby is said to stabilize the levitation system. U.S. Pat. No. 4,382,245 to Harrigan discloses another simple magnetic levitation system which utilizes a dish-shaped lower magnet to magnetically support or levitate a magnetic top spinning coaxially above the lower magnet. The dish-shaped or concave surface of the lower magnet is said to produce radially inwardly directed lines of magnetization which, together with the gyroscopic effect of rotation of the magnetic top, provide stabilization ,of the levitation system. The Harrigan patent discloses another embodiment in which stabilization is said to be provided by a combination of the concave lower magnet surface and a pendulum effect resulting from a non-magnetic mass supported below the lower magnet on an arm extending from the upper magnet through a central bore in the lower magnet. Other embodiments are disclosed in which the lower field is not provided by a dish-shaped magnet but is provided by a plurality of cylindrical magnets arranged similarly to the arrangement of the aforementioned Neal patent. SUMMARY OF THE INVENTION The present invention is directed to a magnetic levitation device and method that accomplishes stable, unrestrained levitation of one magnet above another magnet by utilizing a previously unrecognized characteristic of the magnetic field above a magnetized surface and by incorporation of a rotational motion of the levitated magnet. Although the magnetic levitation device of the present invention may have other applications not specifically described herein, it is intended to provide an educational or amusement device that may be readily manufactured at low cost and operated simply, reliably and reproducibly with minimal instruction. In our prior copending application U.S. patent application Ser. No. 08/197,845 filed Feb. 17, 1994, now U.S. Pat. No. 5,404,062, the complete disclosure of which is incorporated herein by reference, we disclosed a magnetic levitation device and method. The levitation device comprises a uniformly magnetized flat or substantially planar magnetic base above which is caused to levitate a spinning magnetic top made of a flat ring magnet, a nonmagnetic spindle and one or more nonmagnetic weights for adjusting the mass and therefore the height of levitation of the spinning magnetic top. For a substantially uniformly magnetized base or shell it was explained in our prior application that the outer periphery of the base or shell affects the stability of a levitation system incorporating the shell. In particular, a shell having a polygonal shaped periphery has a region a few centimeters above the surface of the shell and along the diagonals thereof where the magnetic field gradients are such as to provide both lifting and centering forces on a magnetic dipole (the spinning top) in that region. It was observed that non-polygonal peripheral shapes, such as circular and elliptical shapes, of a uniformly magnetized shell did not appear to provide the aforementioned region where both lifting and centering forces exist. As was explained in our aforementioned prior application, now U.S. Pat. No. 5,404,062, the height at which the dipole magnet levitates can be increased by weakening the magnetic field at the geometric center of a polygonal (square) shell or base magnet. Such weakening can be accomplished by cutting a hole in the center of the shell magnet or by mounting a magnetic disk of opposite polarity over the geometric center of the base magnet. It has now been found according to the present invention, that the outer periphery of the shell or base magnet need not be polygonal in shape if the magnetic field of the base magnet is made non-uniform by partial demagnetization in a central region of the base magnet. In other words, the outer periphery of the flat base magnet can be any shape, e.g., circular, elliptical, polygonal, if the magnetic field of the base magnet is partially demagnetized or weakened to some extent at or near a central region of the base magnet, preferably at or near the geometric center of the base magnet. The magnetic field may be weakened by cutting a central hole in the base magnet or by mounting a smaller magnet such as a disk magnet of opposite polarity in a central region of the base magnet. It is preferred, however, to weaken the magnetic field of the base magnet by applying a strong magnet field of opposite polarity, e.g., with an electromagnet or permanent magnet, to a central region of the base magnet to permanently weaken or partially demagnetize a portion of the central region. In addition to making possible the use of a base magnet having virtually any peripheral shape, the present invention also causes the levitated spinning dipole (top) to float or levitate at a greater height than for a uniformly magnetized base. Furthermore, it has been found that the top is more easily spun when the magnetic field of the base is weakened. A further feature of the method of the invention is the use of controlled partial demagnetization or weakening of the magnetic field in the central region of the base magnet to “calibrate” the levitation device by making the spinning top more stable. This feature, together with the adjustment of the weight of the spinning top, can be used to achieve an easily spun top which levitates in a relatively stable position for several minutes. Still another feature of the invention is the use of small wedges or shims to adjust the position of the magnetic field of the base magnet with respect to the local vertical. This position adjustment helps to stabilize the levitation of the spinning magnet above the base magnet. With the foregoing and other advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims and to the several views illustrated in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-4 are a perspective views of one embodiment of the improved magnetic levitation device of the invention showing the method of operating the device of the invention; and FIG. 5 is a perspective view of the base magnet shown in FIGS. 1-4 illustrating the weakened magnetic field in the central region thereof. DETAILED DESCRIPTION OF THE INVENTION A first embodiment of the invention is shown in FIG. 1. A first or base ceramic magnet 10 having a circular periphery of about 10 cm in diameter and a thickness of about 0.7 cm is disposed horizontally on a level surface T. Magnet 10 is magnetized normal to its large surface area with (for description purposes) its north (+) pole oriented upwardly. As described hereinafter, a central region of the magnet 10 has been demagnetized to an extent sufficient to weaken the magnetic field in that region. A non-magnetic lifter plate 12 , such as a transparent plastic sheet, rests on the base magnet 10 with an edge or handle 11 extending beyond the base magnet 10 . On the lifter plate 12 a top 13 is held by the hand H of a user for operation in the manner described hereinafter. Top 13 comprises a second magnet, such as a ceramic ring magnet 14 , with (for description purposes) its north (+) pole oriented downwardly toward the like north pole of the first or base magnet 10 . A spindle 18 , preferably made of a non-magnetic material, is fitted tightly into the central hole or ring magnet 14 for manually imparting spin to the ring magnet 14 . One or more non-magnetic washers 16 are placed over the spindle 18 and fits snugly on the spindle 18 in the manner shown in FIG. 1 . Washers 16 are used for weight adjustment of the magnetic top 13 as described in more detail hereinafter. Top 13 is held against the lifter plate 12 above the geometric center G of base magnet 10 and is spun, either by hand or by any appropriate mechanism, such as a cord. Referring now to FIG. 2 which shows top 13 spinning clockwise, the user grips handle 11 and raises lifter plate 12 vertically upwardly in the direction of arrow 20 . The user lifts the plate 12 slowly by hand until the spinning top 13 approaches the height of maximum negative gradient of the vertical component of the magnetic field. Now referring to FIG. 3, the top 13 has passed through the height of maximum negative gradient generally represented by dimension h 1 , which causes it to lift or levitate upwardly in the direction of arrow 22 off the surface of lifter plate 12 to a new height h 2 . As shown in FIG. 4, the lifter plate 12 may (but need not) be removed, e.g., in the direction shown by arrow 24 . The spinning top 13 will remain levitating or floating above the geometric center G of base magnet 10 as shown in FIG. 4 until the rotation rate of the top 13 drops below that which will maintain the system stable. If the top 13 does not lift off the lifter plate 12 as shown in FIG. 3, it is too heavy and one or more washers 16 should be removed before the procedure is repeated. If the top 13 suddenly jumps off the lifter plate 12 , becomes unstable and falls, the top is too light and one or more washers 16 (FIG. 1) should be added to the spindle 18 before the procedure is repeated. When the top is correctly weighted, it will rise gently off the lifter plate 12 as the peak negative gradient is approached and levitate. In actual operation, the top 13 will levitate or float for several minutes during which time it precesses, nutates gently up-and-down and from side-to-side until it slows and falls onto the base magnet. Also shown in FIG. 4 are a pair of wedge-shaped shims 17 , 19 which are used to adjust the position of the plane of the upper surface 21 of the base magnet 10 . It is desirable that the surface T be substantially level so that the upper planar surface 21 of the base magnet 10 is also level, at least initially. It has been found, however, that even if the base magnet 10 is perfectly level, the spinning top 13 may quickly drift in one direction from its levitating position shown in FIG. 4 and fall. Should that occur, one of the shims 17 , 19 is placed under the edge of the base magnet 10 along the direction the spinning top drifted so as to slightly raise the base magnet 10 at that point. The top 13 is again spun and levitated as shown in FIGS. 1-4 and if the top 13 still drifts in the same or a different direction, the shims 17 , 19 are used to again slightly raise the edge of the base magnet along the direction of drift. By appropriate adjustment and positioning of the shims 17 , 19 the spinning top can be made to levitate nearly directly above the geometric center G of the base magnet 10 for several minutes. Referring now to FIG. 5, the base magnet 10 is shown with a central region R (shown in dashed lines) in which the magnetic field has been weakened in one of three ways. First, the weakened magnetic field in region R may be achieved by cutting a hole 26 in the geometric center G of the base magnet 10 . Secondly, a magnetic disk 28 of opposite polarity, i.e., with its south (−) pole oriented upwardly over the geometric center G of the base magnet 10 , may be mounted to region R by adhesive bonding or by any other suitable fixing means. Thirdly, a magnet, such as an electromagnet or permanent magnet (not shown), with a strong magnetic field may be positioned at region R and energized so that the magnetic field of the electromagnet or permanent magnet opposes that of base magnet 10 and effects a permanent partial demagnetization or weakening of the magnetic field in region R of magnet 10 . It should be understood that while the region R is depicted in FIG. 5 as a circular region in the center of base magnet 10 , the partial demagnetization is not necessarily centered in the base magnet and does not necessarily create a reduced field of circular shape. This latter method is a preferred method since it involves no structural changes to the base magnet and is easily adjusted since the entire base magnet can be remagnetized over its entire surface and demagnetized in region R again and again. It is also possible to use this latter technique for adjusting or calibrating the magnetic field of the base magnet to achieve more stable levitation of the spinning top. Because of the inherent instability of opposed polarity magnetic systems, it is advantageous to adjust or calibrate the levitation device of the present invention to improve the ease of use of the device. While it is desirable that the use of the levitation device of the invention requires a certain degree of skill to achieve levitation, if the user becomes frustrated by an inability to operate the device, the marketability and success of the device can be adversely affected. It has been found that by appropriate application of a demagnetized field in the central region of the base magnet, i.e., position of application and strength of the demagnetized field, both the height and stability of levitation can be increased. Because of the many variables involved, e.g., relative field strength of the magnets, mass of the spinning magnet, local magnetic fields, uniformity of magnetization, etc., calibration by partial demagnetization cannot be precisely controlled and calibration procedures are to some extent based on operator experience and empirical information. Although certain presently preferred embodiments of the invention have been described herein, it will be apparent to those skilled in the art to which the invention pertains that variations and modifications of the described embodiment may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention be limited only to the extent required by the appended claims and the applicable rules of law.

An improved magnetic levitation device has a first base magnet with a partially demagnetized central region over which a second dipole magnet is spun or rotated so as to levitate above the first magnet. The levitation device may be calibrated for stability and height of levitation of the second magnet by selected demagnetization of portions of the first magnet.

BACKGROUND OF THE INVENTION [0001] The present invention relates to an arrangement of car walls for an elevator car. [0002] Elevator cars, particularly in passenger elevators, have several essentially vertical car walls which, arranged adjacent to each other, bound the internal space. Since, during building construction, the elevator hoistway is sometimes first completed to such an extent that the complete elevator car in its entirety can no longer be inserted into the elevator hoistway, the elevator car must be subsequently assembled from individual components inside the hoistway. For this purpose, the individual car walls should be easy to assemble with each other, as far as possible from the inside. For maintenance, for the replacement of damaged car walls, or for the replacement of the entire elevator car, such as in the case of a modernization, the individual car walls should also be easy to disassemble again. [0003] For this purpose, U.S. Pat. Nos. 5,842,545 and 6,082,501 respectively propose car walls of metal sheeting in which on a vertical end-face of a car wall a hook-shaped flange that is angled toward the inside engages with a hook-shaped flange that is angled toward the outside on an abutting end-face of an adjacent car wall. The outwardly angled flange projects beyond the outside of the car wall and disadvantageously enlarges the total external dimension the elevator car. Furthermore, the projecting flanges are susceptible to the effects of forces from outside that can damage the flange connection and thereby either loosen the connection of the car walls or, conversely, cause the flanges to be bent together in such manner that they can no longer be released. [0004] U.S. Pat. No. 4,357,993 and DE 24 53 196 A1 show as alternative an elevator car in which flanges that project from a first car wall beyond its end-face engage from above in vertical recesses in the adjacent car wall or in recesses in flanges that project from the adjacent car wall beyond its end-face. Here, too, flanges project disadvantageously that enlarge the overall dimension of the elevator car and are susceptible to damage. [0005] U.S. Pat. No. 3,632,146 discloses an elevator car with a car wall arrangement, having a first car wall on whose outside a first flange is arranged that projects beyond a first end-face of the car wall and is angled by 270° from the outside. Arranged on the outside of an adjacent car wall is a second flange that projects parallel to the outside beyond the second car wall and engages vertically from below in a recess of the first flange. In this arrangement, too, both flanges project beyond the outside of the car walls in such manner that they disadvantageously enlarge the external dimension of the elevator car and are susceptible to damage from outside. SUMMARY OF THE INVENTION [0006] The task of the present invention is therefore to create a car-wall arrangement for an elevator car that in the installed state enlarges the external size of the elevator car only slightly or not at all. [0007] This purpose is fulfilled by a car-wall for an elevator car according to the invention that comprises a first car wall, on whose outside that faces away from the inside of the car is arranged at least one first joining element with a first flange that projects beyond a first end-face of the first car wall and is angled from the outside at a joining angle that is greater than 180° and less than 360°. This flange thus contains an interior angle greater than 0° and less than 180° to the vertical plane of the first car wall and is angled toward the inside of the car. In the case of a right-angled elevator car, the joining angle according to the invention is, for example, essentially 270°, which corresponds to an interior angle of 90° to the vertical plane. For example, in the case of a hexagonal or octagonal elevator car, the joining angle according to the invention is correspondingly approximately 240° or 225° respectively, etc. The total number of car floor plans that are possible is unlimited, the joining angle according to the invention always corresponds to the angle between the outside of the first car wall and an adjacent second car wall. [0008] An arrangement of car walls for an elevator car according to the invention also comprises a second car wall, on whose outside that faces away from the inside of the car is arranged at least one second joining element with a second flange that projects beyond a second end-face of the second car wall and is turned away from the outside of the second car wall by the same joining angle. [0009] Consequently, in the installed state, the first flange lies against the outside of the second car wall and the second flange, which can be arranged correspondingly lower, lies against the outside of the first car wall. Thus, in a car wall arrangement according to the invention, the flange projects only a little or not at all beyond the outsides, and thus the external dimensions of the elevator car are essentially determined by the outsides themselves. Also, the flanges that rest against the outsides are well protected against mechanical damage. [0010] The car wall arrangement of the present invention can be easily installed from inside: After the second car wall has been erected in its vertical position, the first car wall with its first end-face is placed against the second end-face of the second wall and then turned about its vertical edge, whereby the first flange and the second flange embrace the outside of the respective other car wall and thereby hold the two car walls against each other by positive engagement. In the opposite sequence, the walls can also be uninstalled. Self-evidently, also in the opposite sequence, the first car wall can be erected in its vertical position and the second car wall then placed against it. [0011] Against the free end-face of the first and/or second car wall a further car wall can be fastened in the same way, so that the entire walling of the elevator car can be easily installed and uninstalled from within. [0012] In a preferred embodiment of the present invention, the first joining element in the form of a corner section embraces the first flange and a third flange that is bent around the joining section and fastened to the first flange and fastened on the outside of the first car wall in such manner that in the installed state its lower end-face touches the upper end-face of the second flange of the second joining element. The third flange can be joined to the outside releasably, for example by means of screws or pluggable connectors, or non-releasably, for example by means of adhesive bonding or welding. In particular, the outside and the third flange can also be executed integrally, for example as a molding. [0013] The upper end-face of the second flange, that in the installed state rests against the outside of the first car wall, touching the lower end-face of the third flange that is fastened to this outside, and the car walls being fastened by positive engagement in the horizontal direction by the first and second flange, that in each case mutually embrace the respective other outside, cause additionally a positively engaged fixing in vertical direction through the third flange that rests from above on the second flange and thereby prevents a movement of the second car wall in upward direction or a movement of the first car wall in downward direction. [0014] In an advantageous further development of the present invention described above, the lower end-face of the third flange and the upper end-face of the second flange slope relative to the horizontal. With this embodiment, during installation the first car wall is placed with its end-face slightly higher than the second car wall, turned about its end-face until the first and second flange rest against the respective outside, and then the first car wall lowered in downward direction. When this is done, the sloping end-faces of the second flange and third flange slide over each other and position the first car wall at the desired horizontal distance from the second car wall. [0015] In the installed position, the embracing first flange prevents a horizontal movement of the first car wall away from the second car wall, and the touching end-faces of the second and third flange prevent a horizontal movement of the first car wall toward the second car wall. This is because these end-faces would then slide on each other and force the first car wall vertically upward. However, firstly, such an offset acts against the own weight of the first car wall. Secondly, the car roof and car floor can be advantageously, for example by means of tie rods, tensioned against each other in vertical direction and embrace the car wall arrangement between them so that especially the car roof also prevents a vertical offset of the first car wall and thereby, because of the sloping end-faces, also a horizontal movement relative to the second car wall. It is therefore preferable for the second flange to taper toward its vertical end-face that is distant from the second car wall, i.e. the slope runs downward in the direction of the first car wall. [0016] In a further preferred embodiment of the present invention, that can also possess the characteristics of the embodiments described above, the second joining element in the form of a corner section embraces the second and a fourth flange, that is joined to the second flange and fastened onto the outside of the second car wall, in such manner that in the installed state its upper end-face touches the lower end-face of the first flange of the first joining element. Like the third flange, the fourth flange can be joined to the outside releasably, for example by means of screws or plug connectors, or non-releasably, for example by means of adhesive bonding or welding. In particular, the outside and the fourth flange can be also be executed integrally, for example as a molding. [0017] This embodiment brings the same advantages as the preferred embodiment that is described above. Through the upper end-face of the first flange, that in the installed state rests against the outside of the second car wall, touching the upper end-face of the fourth flange that is fastened to this outside, and the car walls being fastened by positive engagement in the horizontal direction by the first and second flange, results additionally also a positively engaged fixing in vertical direction through the first flange that rests from above on the fourth flange and thereby prevents a movement of the second car wall in upward direction or a movement of the first car wall in downward direction. [0018] In an advantageous further development of the preferred embodiment of the present invention described above, the lower end-face of the first flange and the upper end-face of the fourth flange slope relative to the horizontal. With this embodiment, as with the further development described above, whose characteristics can be realized in addition, during installation the first car wall is placed with its end-face slightly higher than the second car wall, turned about its end-face until the first and second flange rest against the respective outside, and then the first car wall lowered in downward direction. When this is done, the sloping end-faces of the first and fourth flange slide over each other and position the first car wall at the desired horizontal distance from the second car wall and fix the former relative to the latter. For this purpose, it is therefore preferable for the first flange to taper toward its vertical end-face that is distant from the first car wall, i.e. the slope runs upward in the direction of the second car wall. [0019] If the two advantageous embodiments that are described above are combined, it is possible in a preferred embodiment of the present invention for the lower end-face of the first and third flange to slope in the same direction and in particular to have the same angle relative to the horizontal. By this means, the guidance during lowering is lengthened, and on account of the greater supporting surface, the two car walls are fixed more reliably in their position relative to each other. Conversely, the lower end-faces of the first and third flanges can also slope in opposite directions, in particular having the same size of joining angle relative to the horizontal. It is preferable for the first and third flanges to form at their point of joining a recess that is downwardly open, into which a complementary point engages, which is formed at the joining point between the second and fourth flange. Conversely, a point that is formed by the first flange and third flange can engage in a corresponding recess between the second flange and third flange. In the case of an opposite slope, the resulting point advantageously fixes the two car walls in the two horizontal directions, i.e. the two car walls can neither be pushed toward each other nor away from each other horizontally, since on account of their own weight and if applicable also that of the car roof resting on them from above, they act counter to the sloping end-faces sliding over each other. Alternatively, only the edge-faces of the first and fourth flanges, or only of the second and third flanges, can be sloping, the others being essentially horizontal. [0020] In a preferred embodiment of the present invention, in the installed state the first flange engages in a recess on the outside of the second car wall and/or the second flange engages in a recess on the outside of the first car wall. By this means, the overall external dimension can be further reduced and the flange even better protected against damage. [0021] In an advantageous embodiment, in the installed state the second end-face of the second car wall rests against the third flange, or the first end-face of the first car wall rests against the fourth flange, in such manner that a horizontal movement of the one car wall beyond the outside of the other is prevented. In the same way, the third and fourth flanges respectively can have spacers that rest against the second and third end-faces respectively, and secure the latter against a horizontal movement against this flange. [0022] In a preferred embodiment of the present invention, in the installed state a gap for ventilation of the elevator car remains between the first and the second end-faces. This can be secured by, for example, horizontal fixing by means of sloping upper or lower end-faces and/or resting of an end-face of a car wall against the flange of the other car wall or against corresponding spacers as described above. [0023] If the first and/or second car wall are advantageously formed as plates of sandwich construction with greater wall thickness instead of the metal sheeting usual until now, which particularly improves the thermal and acoustic insulation, provided that the car walls are not joined to each other vertically from above but by turning about a vertical axis, a certain amount of gap inevitably remains. Since when this turning takes place, in which the vertical edges of the first end-face and second end-face respectively that face away from each other and slide on the inside of the second flange and first flange respectively, the two vertical edges of the end-faces that face each other must be able to pass the respective other car wall without penetration. Therefore, the greater the wall thicknesses of the first car wall and second car wall, i.e. the further apart the vertical edges of the end-faces that face toward each other and away from each other, the greater in installed state is the remaining gap that is needed to fasten the two car walls to each other by turning horizontally. In the same manner there can be only one gap between an end-face of the one car wall and the inside of the other car wall, while the end-face of the other car wall rests flush against the flange of the one car wall. In the same way, between the two end-faces and the insides of the car-walls that face each other, gaps can also remain that can then be embodied smaller than one single gap. [0024] In particular, with a preferred car-wall arrangement as described above, whose first and second car wall are embodied as plate elements with a particular wall thickness, for example in sandwich construction, and on installation by horizontal turning of the two car walls toward each other, a gap remains between at least one end-face of the one car wall and the inside of the other car wall, the embodiment that was explained above of the mutually touching upper and lower end-faces of the first and fourth, or third and second flange as sloping end-faces is advantageous. This is because, as described above, the two car walls can also be fixed relative to each other in their horizontal degrees of freedom so that the play that is caused by the gap that is necessary for installation is reduced or preferably largely eliminated. On account of the sloping end-faces of the first flange and fourth flange and/or of the second flange and third flange that touch each other, that car wall between whose end-face and the inside of the other car wall a gap remains cannot move in the direction of the gap. [0025] In a preferred embodiment of the present invention, the first flange has on its lower end-face that faces the fourth flange a corresponding recess in which in the installed state a corresponding projection on the end-face of the fourth flange engages. In the same way, the projection can be embodied on the first flange and the recess on the fourth flange. Additionally or alternatively, the second flange has on its upper end-face that faces toward the third flange a recess in which in the installed state a corresponding projection on the end-face of the third flange engages. Here too, in the same way, the projection can be embodied on the second flange and the recess on the third flange. By this means, horizontal pulling apart of the car walls is effectively prevented. [0026] It is preferable for the first and second car walls to have several, and preferably different, joining elements according to the invention. [0027] Further purposes, characteristics, and advantages of the present invention follow from the claims and exemplary embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0028] Shown are in [0029] FIG. 1 in diagrammatic three-dimensional view with the car roof omitted, an elevator car with a car-wall arrangement according to a first embodiment; [0030] FIG. 2 a partial horizontal cross section of the car wall arrangement along the line II-II in FIG. 1 ; [0031] FIG. 3 a partial cross section corresponding to FIG. 2 along the line III-III in FIG. 1 ; [0032] FIGS. 4a, 4b diagrammatically, the installation of a car wall arrangement according to the invention; [0033] FIG. 5 a partial cross-section according to FIG. 2 of a second embodiment of the present invention; [0034] FIG. 6 a partial cross-section according to FIG. 2 of a third embodiment of the present invention; and in [0035] FIG. 7 a three-dimensional view corresponding to FIG. 1 of an elevator car with a car wall arrangement according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0036] FIG. 1 shows diagrammatically in three-dimensional view an elevator car with a car-wall arrangement according to the invention from which for clarity the car roof has been removed. The car wall arrangement comprises in particular a first car wall 10 in the form of a left side wall and a second car wall 20 in the form of a rear wall. However, this arrangement is arbitrary—in particular, as shown in FIG. 1 , a car wall arrangement as shown in FIG. 1 can also comprise a right side wall and a left or right front wall, each of these walls being able to form a first or second car wall. In a further not shown embodiment with non-rectangular (for example hexagonal) car floor plan, it is also possible, for example, for two adjacently located side walls to form a first and second car wall. [0037] Fastened by means of screws to the first car wall 10 is a first joining element 12 in the form of a corner section. This corner section, that can be made, for example, of metal, in particular of steel or aluminum, comprises a third flange 15 that is screwed onto the outside 11 of the first car wall 10 . In a further embodiment that is not shown, this flange can also be embodied integrally with the outside, for example welded to the latter. The joining element further comprises a first flange 13 which, relative to the outside 11 , or third flange respectively, is angled at a joining angle α of 270° to the car interior. [0038] In the installed state shown in FIG. 1 , this first flange 13 embraces the outside 21 of the second car wall 20 and rests against it. Fastened in similar manner onto the second car wall 20 by means of screws is a second joining element 22 in the form of a corner section that can also be made, for example, of metal, particularly steel, and that contains a fourth flange 25 that is screwed onto the outside 21 of the second car wall 20 . Alternatively, in a further not shown embodiment, this flange can also be embodied integrally with the outside, for example welded to the latter. The second joining element further contains a second flange 23 which, relative to the outside 21 or fourth flange respectively, is angled at the same joining angle α of 270° to the car interior and in the installed state embraces the outside of the first car wall 10 and rests against it. [0039] In the direction from the third to the first flange, the lower end-faces of the first and third flanges 13 , 15 slope upwards and have the same angle relative to the horizontal. In the direction from the fourth to the second flange, the upper end-faces of the second and fourth flanges 23 , 25 slope downward and have the same angle relative to the horizontal so that in the installed state the upper and lower end-faces respectively of the four flanges 13 , 15 , 23 , and 25 touch over a large area. [0040] For installation, the second car wall 20 is first joined to the structure of the elevator car by being, for example, lowered from above into a surrounding groove in the car floor that is not shown. Alternatively or additionally, the second car wall can also be screwed to the elevator floor or its frame by means of, for example, a corner section. Subsequently, the first car wall 10 with its first end-face 14 beyond which the first flange 13 projects, is laid linearly flush against the second end-face 24 of the second car wall, the first car wall 10 being upwardly offset in vertical direction relative to its final position. Subsequently, as indicated by an arrow in FIG. 4 a , the first car wall is turned about its first end-face 14 , upon which the vertical edges of the end-faces that face away from each other slide on the inside of the first and second flanges respectively until the first flange 13 rests against the outside 21 of the second car wall 20 . At the same time, the vertical edges of the end-faces that face each other move past each other without penetrating the other car wall. Depending on the wall thickness of the car walls, in finally turned position a certain amount of gap remains between the two car walls (see FIGS. 2, 3 ). Following this, as indicated by an arrow in FIG. 4 b , the first car wall is lowered vertically down relative to the second car wall into the final installation position, in which the lower end-faces of the first and third and the upper end-faces of the second and fourth flanges touch over a large area. The end-faces sliding over each other thereby automatically move the flange of the first car wall in horizontal direction into its end position relative to the second car wall. In the vertical end position, the first car wall also engages in the surrounding groove in the car floor. [0041] In this installed position, the first car wall is fixed in the horizontal degrees of freedom on the second car wall by the two joining elements 12 , 22 : movement of the first car wall 10 in its plane vertically away from the second car wall (in FIG. 2 to the left) is counteracted by the first flange 13 that embraces with positive engagement the outside 21 of the second car wall 20 . Horizontal movement in the opposite direction acts against the third flange 15 . In the case of a corresponding movement, the latter would slide upward over the sloping end-face of the second flange—however, such a movement is counteracted by the own weight of the first car wall as well as the car roof that is finally fastened on to it. This (not shown) car roof can, for example, be tensioned by means of tie rods to the car floor and fix the car walls in vertical direction. A horizontal movement of the first car wall 10 perpendicular to the directions explained above, thus in the plane of the second car wall 20 (upward/downward respectively in FIG. 2 ) is counteracted in similar manner by the second flange 23 and the third flange 15 respectively, the third flange 15 resting via the first flange 13 on the fourth flange 25 . [0042] The first car wall can thus be rapidly fastened onto the second car wall without additional tools and from the inside. Further car walls can also be installed in similar manner, as indicated in FIG. 1 . In reverse sequence, the car walls can also be easily dismantled. [0043] As FIG. 2 shows, in the embodiment that is shown here, in the installed state a gap remains between the first end-face 14 of the first car wall 10 and the inside of the second car wall 20 , that is needed for coupling the first car wall 10 to the second car wall 20 on account of the effect of the wall thickness, as can be seen from FIG. 4 a . Advantageously, the gap serves to ventilate the car. During installation, the first end-face 14 can also be laid against the inside of the second car wall 20 . During the subsequent lowering, the lower end-faces of the first and third flanges 13 , 15 slide over the upper end-faces of the second and fourth flanges 23 , 25 and, on account of the complementary slope, inevitably guide the first car wall into the desired horizontal position, i.e. maintain a gap between the first car wall and the second car wall. [0044] As shown in FIGS. 2, 3 , in the installed state, the second end-face 24 of the second car wall 20 rests flush against the third flange 15 . In a second embodiment according to FIG. 5 , a gap can also remain between the first end-face 14 and the inside of the second car wall 20 as well as between the second end-face 24 and the inside of the first car wall 10 through the end-faces of the flanges being correspondingly formed. In this case, each of the two gaps can be smaller than the single gap according to FIG. 2 , with installation being possible nevertheless, i.e. the two vertical edges of the end-faces that face each other move past each other without penetration, when the edges that face away from each other slide on the inside of the flange (see FIG. 4 a ). [0045] In a further embodiment that is not shown, the outsides 11 and/or 22 of the first and/or second car wall 10 , 20 respectively have recesses in which in the installed state the first and/or second flange(s) engage(s). The recesses can be made correspondingly bigger, so as to allow during installation the swiveling-in and lowering movement described above. In such an embodiment, the joining elements are even better protected against damage from outside and do not cause any increase at all in the external dimensions of the elevator car. [0046] FIG. 6 shows a cross section corresponding to FIG. 2 of a third embodiment, in which the size of the joining angle α is not 270° but only 240°. This allows, for example, a hexagonal car floor plan to be created. Depending on the car floor plan, other joining angles are also possible that result from the end position of the car walls relative to each other. [0047] FIG. 7 shows a fourth embodiment of the present invention in which the lower end-faces of the first and third flanges 13 , 15 slope oppositely as do also the upper end faces of the second and fourth flanges 23 , 25 . In the installed state, when being lowered the first car wall 10 centers relative to the second car wall 20 and fixes both walls in all horizontal degrees of freedom. [0048] In the same way, the lower end-face of the first flange 13 and the complementary upper end-face of the fourth flange 25 and/or the lower end-face of the third flange 15 and the complementary upper end-face of the second flange 23 do not slope but run essentially horizontally as indicated/outlined in the joining elements of the first car wall 10 to the front wall and of the second car wall 20 to the right side wall in FIGS. 1 and 7 . [0049] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited but by the specific disclosure herein, but only by the appended claims.

A car wall arrangement for an elevator car having a first car wall, on whose outside is arranged at least one first joining element with a first flange that projects beyond a first end-face of the first car wall and is angled from the outside by a joining angle that is greater than 180° and less than 360°. A second car wall is provided on whose outside is arranged at least a second joining element with a second flange that projects beyond a second end-face of the second car wall. The second flange is turned away from the outside of the second car wall by the same joining angle α so that in the installed state the first flange rests against the outside of the second car wall and the second flange against the outside of the first car wall.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application Ser. No. 12/970,393, filed Dec. 16, 2010, which claims benefit of the filing date of U.S. Provisional Patent Application No. 61/287,793, filed Dec. 18, 2009, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The field of this invention pertains to a bone cement for bone filler applications and in the preparation of such cement. More specifically, the invention relates a post irradiation shelf-stable dual paste direct injectable bone cement precursor systems suitable for implanting within the human body and methods of making same. BACKGROUND OF THE INVENTION [0003] Calcium phosphate based cements (CaPC) have been used as bone substitutes and bone grafts for nearly twenty years. In the 1980s, the research was focused on developing a formulation that was biocompatible for the intended use of clinical applications. These CaPC formulations have historically been provided in the form of a powder and liquid system, which upon mixing becomes a paste and goes through a partial dissolution that initiates a precipitation reaction resulting in the setting of the cement. Often such cements are based on an acid-base reaction to form a salt which usually takes the form of the calcium phosphate phase identified as hydroxyapatite or brushite. [0004] Most of the presently available calcium phosphate precursor cement formulations are still a powder/liquid system wherein the powder and the liquid components are separately packaged and only to be combined prior to use at time of surgery. The mixing is accomplished by either (a) manual mixing, or (b) use of a mechanical based mixing system provided in a commercial product. However, both approaches have some shortcomings. The manual system is sometimes perceived to be time consuming, and user dependent/sensitive. The custom designed mechanical systems aim to provide a more satisfactory user experience by providing consistency and reproducibility for the end user, but are still considered to be cumbersome, difficult to use and cost ineffective. [0005] Accordingly, there have been studies reported with the aim to develop premixed, self-hardening, cement pastes. For example, U.S. Pat. No. 6,793,725 describes a self-hardening calcium phosphate based bone cement paste that is mixed with liquid glycerol, hydroxypropyl methylcellulose and sodium phosphate. This premixed paste formulation allegedly remains stable over a period of time and hardens only when delivered to a desired site in a human body. This premixed paste formulation, however, does not exhibit a good washout resistance when it is applied to an open wet field in a human body, and is therefore limited in utility. [0006] U.S. Patent Publication No. 2006/0263443 also discloses a premixed self-hardening calcium phosphate based bone cement paste containing a gelling agent, such as hydroxymethyl cellulose, carboxymethyl cellulose, chitosan, collagen, gum, gelatin and alginate, to enhance paste cohesiveness and washout resistance. This type of cement, allegedly possesses excellent physical properties, but it is also limited in utility since cement hardening in the interior of the cement mass is slow under some clinical bone grafting conditions, for instance, wherein the amount of water available from the tissue is limited, or wherein the interior of the cement is more than several millimeters away from the nearest graft-tissue interface. [0007] U.S. Patent Publication No. 2007/0092580 teaches a self-setting dual phase cement precursor system composed of a first and second discrete containers, at least one of which is aqueous. The cement formed by combining these two phases, however, do not have a long-term shelf life, as the phases in each of these two pastes packaged in separate containers tend to destabilize/separate during storage. This is especially true after the dual paste system is sterilized using gamma radiation. Therefore, this formulation also is limited in utility. [0008] The present invention aims at responding to the currently unanswered user need for providing a premixed dual paste injectable bone cement precursor system that is shelf stable even after it is sterilized using gamma radiation for in vivo usage, and that rapidly sets as a biocompatible bone cement possessing excellent physical properties when combined. SUMMARY OF THE INVENTION [0009] In one aspect of the invention, the invention relates to a rapid setting bone cement precursor system that is presented in the form of two shelf-stable pastes that are held in separate containers during product transport and storage. When the product is used during surgery, these pastes inject to a site of application through a specially designed static mixing device by the action of applied injection force. When the two pastes are mixed, they start to react to each other while injecting out. The reaction is continued at the site of application in the body environment, wherein the mixture of pastes converts into a bone cement in a specified time. The resulting cement is highly biocompatible, osteoconductive, injectable and bioresorbable that is useful in connection with bone repair procedures, for example, in the craniomaxillofacial, trauma and orthopedic areas. [0010] In another aspect of the invention, the at least two pastes containing bone cement precursors are shelf stable even after terminal sterilization, e.g. using gamma irradiation, for in vivo use. [0011] In yet another aspect of the invention, the invention provides a post irradiation shelf-stable product with greater than 3 month, preferably 6 month, and most preferably greater than 1 year of shelf life. [0012] It is also an aspect of the invention to provide a stable and injectable bone cement precursor system comprising an acidic aqueous paste and an alkaline non-aqueous paste. The pastes themselves are not cements, but they may be combined to form a biocompatible bone cement that is useful in connection with bone repair procedure. [0013] In a preferred embodiment, the acidic aqueous paste and the alkaline non-aqueous paste are designed to withstand terminal sterilization, such as gamma radiation, and still meet the long-term shelf life stability and injectability when kept separate, and reactivity to each other when mixed to set and form hydroxyapatite-based bone cement in a specified time. The resulting bone cement has superior biocompatibility and mechanical properties exhibiting excellent wet field wash out resistant properties. [0014] Terminal sterilization, such as gamma irradiation, and pH have dramatic effect on the structural stability of polymer additives which may be used in these two pastes as they are either degraded into low molecular weight species or cross linked into polymeric gels which alters the viscosity. Accordingly, in order to provide a post irradiation shelf-stable bone cement precursor system, the polymer additives in accordance with an aspect of the present invention must be able to survive the terminal sterilization and extreme pH conditions. [0015] Applicants have found that post irradiation stability is achieved by using synthetic polymers rather than natural cellulose based polymers as paste stabilizing agents in the acidic aqueous paste. Without wishing to be tied to a theory, it is believed that the cellulose polymers are susceptible to degrade into low molecular weight species in acidic aqueous medium during terminal sterilization, thereby affecting the viscosity of the paste during storage. The preferred polymer based stabilizing agent for the acidic aqueous paste is polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG). [0016] With respect to the alkaline non-aqueous paste, Applicants have found that the use of either the natural when preferentially used in combination of antioxidants or synthetic polymers does not affect the alkaline non-aqueous paste's long term storage stability even after it is exposed to the terminal sterilization process, such as gamma irradiation. The preferred paste stabilizing agent for the alkaline non-aqueous paste is polyethylene glycol (PEG), cellulose-based polymer, such as hydroxyethylcellulose (HEC) when preferentially using an antioxidant such as thioglycerol. [0017] According to an aspect of the invention, the acidic aqueous paste composition comprises at least one acidic calcium phosphate mineral, at least one synthetic polymer based paste stabilizing agent, a pH buffering agent and a humectant. [0018] The at least one acidic calcium phosphate mineral is preferably monocalcium phosphate monohydrate (MCPM), monocalcium phosphate anhydrous (MCPA), dicalcium phosphate dehydrate (DCPD), and dicalcium phosphate anhydrous (DCPA). [0019] The at least one synthetic polymer-based paste stabilizing agent is, preferably, polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG). [0020] The pH buffering agent is, preferably, citric acid, tartaric acid and malic acid and their salts, including trisodium citrate and disodium tartarate. The most preferred pH buffering agent is citric acid. [0021] The humectant is, preferably, glycerol and propylene glycol. [0022] In a preferred embodiment, the acidic paste composition comprises monocalcium phosphate monohydrate (MCPM) and dicalcium phosphate anhydrous (DCPA), citric acid, water, glycerol, PVP and PEG. [0023] According to an aspect of the invention, the alkaline non-aqueous paste comprises at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant and a solvent. [0024] The at least one basic calcium phosphate mineral is, preferably, β-tricalcium phosphate, α-tricalcium phosphate, tetracalcium phosphate, oxyapatite, hydroxyapatite or calcium-deficient hydroxyapatite. The most preferred at least one basic calcium phosphate mineral is tetracalcium phosphate (TTCP). [0025] The at least one stabilizing agent used in the alkaline non-aqueous pastes, is preferably either natural with or without an antioxidant or synthetic polymer based. Without wishing to be bound to a theory, it is believed that in a water-free paste system, both the natural and synthetic polymers survive; therefore, providing paste stability during terminal sterilization and storage. The preferred at least one stabilizing agent is polyethylene glycol (PEG), cellulose-based polymer, such as hydroxyethylcellulose (HEC) and the preferred at least one antioxidant for use with the cellulose based polymer is thioglycerol. [0026] The surfactant is, preferably, glycerol monostearate, lecithin, phospholipids, glycerol distearate, polyethylene glycol distearate, block polymers of PEG-PPG-PEG or PPG-PEG-PPG, Tween, Span, any polysorbate fatty acid ester or sorbitol esters. The most preferred surfactant is polysorbate 80 (Tween 80). [0027] The solvent is, preferably, one or more of the following; glycerol, thioglycerol, ethanol, propanol, and propylene glycol. The most preferred solvents glycerin and propylene glycol. [0028] In a preferred embodiment, the alkaline non-aqueous paste comprises tetracalcium phosphate, polyethylene glycol, polysorbate 80, and propylene glycol. [0029] In accordance with another aspect of the invention, the alkaline non-aqueous paste comprises a bimodal mean particle size distribution of at least one basic calcium phosphate mineral in order to maximize the paste stability and cement reactivity. More preferably, the alkaline non-aqueous paste with a bimodal mean particle size distribution of TTCP was demonstrated to produce a bone cement that is superior than when a single mode mean particle size distribution of TTCP in the alkaline non-aqueous paste, when mixed with the acidic aqueous paste. [0030] One aspect of the present invention is a calcium phosphate composition produced by mixing the acidic aqueous paste and the alkaline non-aqueous paste of the present invention. In an embodiment, the calcium phosphate cement is rapid setting. In another embodiment, the calcium phosphate cement is injectable. In yet another embodiment, the calcium phosphate cement is rapid setting and injectable. [0031] One aspect of the present invention is to ease the mixing and application of a CaPC in surgery. The approach taken here has been to completely eliminate the need for the three separate steps whereby the user must (i) mix the powder and liquid components to form a cement paste, (ii) transfer the cement paste into a delivery syringe and (iii) inject the cement paste into a bone cavity. Instead, the intention of this invention is to simplify by combining these three separate steps into one whereby the user is provided with a system that eliminates the need for transfer of the cement paste into a syringe system and concurrently and homogeneously mixes the components during the injection step. [0032] Yet another aspect of the present invention is to a method of making a post irradiation shelf-stable dual paste direct injectable bone cement precursor compositions comprising mixing at least one synthetic polymer based paste stabilizing agent, a pH buffering agent, and water; adding at least one acidic calcium phosphate mineral to the mixture of the at least one synthetic polymer based paste stabilizing agent, the pH buffering agent and water to form an acidic aqueous paste; and mixing at least one paste stabilizing agent, a surfactant, and a solvent; adding at least one basic calcium phosphate mineral to the mixture of the at least one paste stabilizing agent, the surfactant, and the solvent to produce an alkaline non-aqueous paste. [0033] In accordance with the invention, the method may further comprise a step of storing the acidic aqueous paste in a container; storing the alkaline non-aqueous paste in another container; and providing a device which would inject the pastes concurrently from the separate containers to a static mixing device so that said a blended paste of said acidic aqueous paste and said alkaline non-aqueous paste can inject to a site of application by the action of applied injection force. [0034] One aspect of the invention is to provide a kit comprising a dual paste injectable cement precursor system comprising two holding chambers, wherein the first holding chamber comprises an acidic aqueous paste and the second holding chamber comprises an alkaline non-aqueous paste, and a mixing device where the acidic aqueous paste and the alkaline non-aqueous paste are mixed and injected to a site of application by the action of applied injection force. [0035] Another aspect of the invention is to provide a device for a dual paste injectable bone cement precursor system comprising: a syringe body and a static mixing tip, wherein the syringe body comprises a first holding chamber containing an acidic aqueous paste comprising at least one acidic calcium phosphate mineral, at least one synthetic polymer-based paste stabilizing agent, a pH buffering agent and a humectant, and a second holding chamber containing an alkaline non-aqueous paste comprising at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant and a solvent, and the static mixing tip comprises a structure which allows the two pastes to be blended and to be applied to a desired site. In one embodiment, a device is a dual barrel syringe system having a static mixer wherein the acidic aqueous paste of the present invention and the alkaline non-aqueous paste of the present invention are stored in a one to one ratio in each barrel, and be mixed in the static mixer to be blended and initiate setting and be applied to a desired site. In another embodiment, the device and/or the dual barrel syringe system maintains a seal to reduce moisture and air leaks to ensure shelf life protection. BRIEF DESCRIPTION OF THE DRAWINGS [0036] FIG. 1 is a graphical overview of the dispersion analysis results of the acidic aqueous pastes and alkaline non-aqueous pastes of the present invention. [0037] FIG. 2 is a graphical overview of the analysis results of wet field tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. [0038] FIG. 3 is a graphical overview of the analysis results of injectability tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0039] Throughout the entire specification, including the claims, the word “comprise” and variations of the word, such as “comprising” and “comprises,” as well as “have,” having,” “includes,” “include,” and “including,” and variations thereof, means that the named steps, elements or materials to which it refers are essential, but other steps, elements, or materials may be added and still form a construct with the scope of the claim or disclosure. When recited in describing the invention and in a claim, it means that the invention and what is claimed is considered to what follows and potentially more. These terms, particularly when applied to claims, are inclusive or open-ended and do not exclude additional, unrecited elements or methods steps. [0040] The term “cement” herein is used interchangeably with cement formulation, cement composition and bone cement. [0041] The term “between” as used in connection with a range includes the endpoints unless the context suggests otherwise. [0042] The term “long term shelf-life” or “shelf-stable” herein means that the cement precursors(s), such as calcium phosphate mineral(s), and other powder materials in a paste will not separate out from the liquid when exposed to real time and accelerated aging conditions and will set when mixed with the corresponding acidic aqueous/alkaline non-aqueous paste to form a bone cement after the dual paste system has been stored in a sealed container for a predetermined period of time, for at least 1.5 months, preferably 3 months, and more preferably for at least 6 months and most preferably more than 1 year according to the accelerated aging test described in details below. [0043] The term “alkaline non-aqueous paste” as used in accordance with the present invention herein means that this paste includes a non-aqueous solvent such as glycerol or propylene glycol and a basic calcium phosphate mineral, and that the paste is able to be miscible with the acidic aqueous paste. It is contemplated that in an alkaline non-aqueous paste, there may be trace amounts of moisture present, such as moisture that is unavoidably present notwithstanding reasonably prudent steps to exclude such moisture. The alkaline non-aqueous paste itself is not a cement, in that the paste itself does not set to form a hard material in ordinary use. Rather, when the alkaline non-aqueous is combined with the acid aqueous paste, a cement is formed thereby. [0044] The term “acidic aqueous paste” as used in accordance with the present invention herein means that this paste includes water and an acidic calcium phosphate mineral, and that the paste is able to be miscible with the alkaline non-aqueous paste. The acidic aqueous paste itself is not a cement, in that the paste itself does not set to form a hard material in ordinary use. Rather, when the acidic aqueous paste is combined with the alkaline non-aqueous paste, a cement is formed thereby. [0045] The term “injectable” as used in accordance with the present invention herein means that the acidic aqueous paste which is held in one container, and the alkaline non-aqueous paste which is held in a separate container may be delivered to the site of application through a cannula, a needle, a catheter, a syringe or a specially designed static mixing device by the action of an applied injection force. This injection force is tested at an ambient temperature of between 18° C. to 22° C. as set out in Examples 1, 2 and 3 below, and does not exceed 225 N, and more preferably 150 N to allow ease of injectability for the end user. [0046] The term “rapid setting” as used in accordance with the present invention herein means that when the acidic aqueous paste and the alkaline non-aqueous paste are mixed and delivered to a defect site, the mixture forms a cement in about 10 minutes or less, preferably in about 9 minutes or less, most preferably in about 8 minutes or less when the defect temperature is about 32° C. [0047] The term “set” as used in accordance with the present invention herein means that the penetration force measured according to the wet field penetration resistance test described in details below is preferably greater than 10 MPa, more preferably greater than 20 MPa and most preferably greater than 24 MPa. [0048] The term “biocompatible” when used in conjunction with a cement contemplates a cement that is not rejected by soft tissue or hard tissue when used in vivo in the intended application. Kit [0049] Preferably, the system is provided in the form of a kit, the kit including the dual paste injectable cement precursor system comprising an acidic aqueous paste and an alkaline non-aqueous paste in separate moisture impermeable holding chambers (e.g. glass, cyclic olefin copolymer plastic, etc) throughout the products shelf life and an appropriate mixing device. The mixing device may be conventional, or may otherwise be a device suitable for use in conjunction with the cement precursor systems taught in the art. [0050] Preferably, a device having a syringe body with a static mixing tip, the mixing tip comprising an auger-like structure that allows the two pastes to be blended rapidly and subsequently to be applied to the desired area is used in accordance with the invention. The syringe body may include a region that serves as the container for separate pastes, by providing separate holding chambers for the acidic aqueous paste and the alkaline non-aqueous paste. [0051] Any suitable container may be used in conjunction with the invention, and thus, for instance, the container may be any appropriate box, or bag, or package. Cement Precursors in the Pastes [0052] The cement precursors may be any material suitable for use in forming a biocompatible cement. Numerous cement chemistries may be used in conjunction with the invention. In a preferred embodiment, a calcium phosphate cement is employed. In one embodiment, a calcium phosphates cement may be formed by combining at least one calcium phosphate material in at least one of the two precursor pastes. In another embodiment, a calcium phosphate cement, for example, hydroxyapatite, is formed by combining at least two dissimilar calcium phosphate materials present respectively in the two precursor pastes. [0053] The pastes need not include only a single calcium phosphate material, and thus, for instance, the pastes each may include multiple calcium phosphate materials, and some of the third calcium phosphate material may be present initially in either or both of the pastes. [0054] Generally, it is preferred that the Ca/P ratio ranges from 0.5 to 2.0 in each paste. In some embodiments, particularly when it is desired to form hydroxyapatite, one of the pastes includes a calcium phosphate in which the Ca/P ratio is less than 5/3, and the other includes a calcium phosphate compound in which the Ca/P ratio is greater than 5/3. The Ca/P ratio in hydroxyapatite is 5/3, and it is believed that providing calcium and phosphate in both greater and lesser amounts will drive formation of hydroxyapatite. It is not necessary to employ two such pastes, especially if a setting accelerator is used. In some embodiments, the Ca/P ratio in one of the pastes is equal to 5/3. In the formation of hydroxyapatite with the heretofore described calcium phosphate cements, the formation of hydroxyapatite can proceed slowly if the cement is initially formed at a pH above about 8, and if the selection of precursors for such a cement would provide a pH of 8 or above, use of a setting accelerator is preferred. In some embodiments, one may choose the overall Ca/P in order to cause formation of a different calcium phosphate in the resulting cement, such as DCPA or DCPD. [0055] Furthermore, the particle size of the at least one calcium phosphate can be adjusted to modify the rate of the rapid dissolution of calcium phosphate minerals during cement mixing and injection, as the particle size has effects on the chemistry of the setting reactions by controlling the pH and consequently, the setting reaction rate and strength. [0056] The particle size of the calcium phosphate minerals (as well as any other powder components added to each paste) was measured using Beckman Coulter's LS 13320 Series particle size analyzer. It is noted that the particle size values mentioned herein refer to Volume Mean Diameter values. [0057] A sample for analysis was prepared by adding a small amount of powder in a carrier medium. When the powder material is calcium phosphate, ethanol was used. The slurry was mixed aggressively for a short period of time prior to the analysis of the sample. [0058] Volume distributions of mean diameter values were then obtained. Upon measurement completion, the cell was emptied and cleaned and refilled with the slurry of the powder in a carrier medium and repeated several times. Calcium Phosphate Minerals [0059] That at least one source of calcium phosphate useful in accordance with the present invention generally includes numerous calcium phosphate minerals already known in the art, such as those taught by Brown and Chow in U.S. Reissue Pat. 33,161 and 33,221, Chow and Takagi in U.S. Pat. Nos. 5,522,893, 5,542,973, 5,545,294, 5,525,148, 5,695,729 and 6,325,992 and by Constantz in U.S. Pat. Nos. 4,880,610 and 5,047,031, teachings of which are incorporated herein by reference. [0060] Any suitable calcium compound may be used in conjunction with this embodiment of the invention. In preferred embodiments, the calcium compound is a calcium phosphate having a Ca/P ratio ranging from about 0.5-2.0. Alternatively, or in addition thereto, the calcium compound may be a suitable calcium salt, or any suitable calcium compound that is sparing soluble in acid. [0061] Exemplary calcium compounds suitable for use in conjunction with the invention include tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), monocalcium phosphate anhydrous (MCPA), monocalcium phosphate monohydrate (MCPM), alpha-tricalcium phosphate (alpha-TCP), beta tricalcium phosphate (beta-TCP), hydroxyapatite (HA), amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), calcium deficient hydroxyapatite (CDH), carbonate-containing hydroxyapatite (CHA), fluoride-containing hydroxyapatite (FHA), calcium lactate, calcium sulfate, calcium gluconate, calcium lactate gluconate, calcium glycerophosphate, calcium silicate, calcium hydroxide, and other biocompatible calcium compounds with a solubility of at least about 2 wt. % in the acid environment. Generally, calcium compounds that are biocompatible and that form a suitable cement may be used. The selection of a particular calcium compound may be based on numerous factors, including for instance the reactivity of the compound with the selected acid, and also the overall acid and base contents of the cement, and the desired end cement products Acidic Aqueous Paste [0062] In a preferred embodiment, the acidic aqueous paste composition comprises at least one acidic calcium phosphate mineral, at least one synthetic polymer based paste stabilizing agent, a pH buffering agent, a humectant, and water. Acidic Calcium Phosphate Mineral [0063] The acidic calcium phosphate mineral is preferably monocalcium phosphate monohydrate (MCPM), monocalcium phosphate anhydrous (MCPA), dicalcium phosphate dehydrate (DCPD), and dicalcium phosphate anhydrous (DCPA). [0064] In a preferred embodiment, the mean particle size of the at least one acidic calcium phosphate mineral is between about 0.4 μm to about 200 μm, preferably about 0.7 μm to about 150 μm, and most preferably about 1 μm to about 90 μm. [0065] In a more preferred embodiment wherein the acidic aqueous paste contains MCPM and DCPA, the mean particle size of MCPM is between about 0.4 μm to about 200 μm, preferably about 10 μm to about 150 μm, and most preferably about 30 μm to about 90 μm; the mean particle size of the DCPA is between about 0.4 μm to about 200 μm, preferably about 0.7 μm to about 50 μm, and most preferably about 1 μm to about 20 μm. [0066] With respect to an amount of the acidic calcium phosphate mineral present in the acidic aqueous paste, it may be present in an amount of between about 1% w/w and about 80% w/w, and preferably about 5% w/w and about 65% w/w based on the total weight of the acidic aqueous paste. [0067] In a preferred embodiment wherein the acidic aqueous paste contains MCPM and DCPA, MCPM may be present in an amount of between about 1% w/w and about 40% w/w, more preferably between about 5% w/w and about 20% w/w based on the total weight of the acidic aqueous paste; and DCPA may be present in an amount of between about 20% w/w and about 80% w/w, more preferably between about 40% w/w and about 65% w/w based on the total weight of the acidic aqueous paste. Synthetic Polymer Based Paste Stabilizing Agent for the Acidic Aqueous Paste [0068] The synthetic paste stabilizing agent in accordance with the present invention can be any material useful for stabilizing the acidic aqueous paste to prevent or retard an unwanted alteration of the physical state, such as separation of the powder components from the liquid components even after the paste is exposed to gamma radiation for terminal sterilization. [0069] Applicants have found that post irradiation stability of the acidic aqueous paste is achieved by using synthetic polymer based paste stabilizing agent rather than natural cellulose based polymer. Without wishing to be tied to a theory, it is believed that the natural cellulose polymers are susceptible to degrade into low molecular weight species in acidic aqueous medium during terminal sterilization, thereby affecting the viscosity of the paste during storage. [0070] The synthetic polymer based paste stabilizing agent in accordance with the present invention allows the acidic aqueous paste to stay storage stable for a long term, even after it is exposed to gamma radiation for sterilization. [0071] Examples of a paste stabilizing agent which can be used in the acidic aqueous paste, without limitation, are PVP and PEG. [0072] Although PVP is quite often cross linked in a basic medium during terminal sterilization, in an acidic medium, it is believed that the rate of cross linking is slow, especially in the presence of calcium salts as the pyrrolidone ring is primarily engaged with calcium salts through ionic interactions. Accordingly, the pyrrolidone ring is protected from not being opened and cross-linked. Although an acidic aqueous paste comprising a higher amount of PVP provides greater stability, this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when PVP is used as a synthetic polymer based paste stabilizing agent for the acidic aqueous paste, it must be present in an optimal level. [0073] The mean molecular weight (Mw) of the PVP in the acidic aqueous paste is between about 1,000 Mw to about 1,000,000 Mw, preferably between about 10,000 Mw to about 100,000 Mw, more preferably about 20,000 to about 80,000 Mw, even more preferably about between 40,000 Mw to about 70,000 Mw, but most preferably between 50,000 Mw to about 60,000. [0074] With respect to the amount of the PVP in the acidic aqueous paste, the PVP may be present in an amount of between about 0% w/w and about 40% w/w, more preferably between about 0.05% w/w and about 20% w/w, but most preferably between 1% w/w to 10% w/w based on the total weight of the paste. [0075] It is also believed that PEG bonds with hydrogen molecule in the acidic aqueous paste, thereby slowing down the mobility of water molecules in the system to produce stability. The molecular weight of the PEG chain is important as rigidity of the chain itself plays important role in stability. Although an acidic aqueous paste comprising a higher amount of PEG provides greater stability; this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when PEG is used as a synthetic polymer based paste stabilizing agent for the acidic aqueous paste, it must be present in an optimal level. [0076] The mean molecular weight (Mw) of the PEG in the acidic aqueous paste is between about 1,000 Mw to about 60,000 Mw, preferably between about 5,000 Mw to about 40,000 Mw, more preferably between about 10,000 Mw to about 40,000 Mw, but most preferably between 15,000 Mw to about 25,000 Mw. [0077] With respect to the amount of the PEG in the acidic aqueous paste, the PEG may be present in an amount of between about 0% w/w and about 40% w/w, more preferably between about 0.05% w/w and about 20% w/w, but most preferably between 1% w/w to 10% w/w based on the total weight of the paste. pH Buffering Agent [0078] In the acidic aqueous paste, a pH buffering agent is added to the paste in order to provide lower pH as well as to form ionic interaction with at least one acidic calcium minerals to provide paste stability. Without wishing to be bound to a theory, it is also believed that the pH buffering agent in accordance with the present invention can act as a setting accelerating agent, influencing the setting reaction once the acidic aqueous paste and the alkaline non-aqueous paste systems are combined. [0079] Examples of a pH buffering agent which can be used in the present invention, without limitation, are citric acid, phosphoric acid, tartaric acid and malic acid and their salts, including trisodium citrate, sodium phosphate monobasic and disodium tartarate. The preferred pH buffering agent is citric acid. The citric acid can come in several forms, which are anhydrous, monohydrate, or dihydrate. The preferred form of citric acid is the monohydrate form. [0080] The pH buffering agent is present in an amount of between about 1% w/w to about 10% w/w, or more preferably, in an amount of between about 5% w/w to about 8% w/w. Humectant [0081] The humectant in accordance with the present invention can be any material to help the water molecules within the acidic aqueous paste intact through formation of hydrogen bonds, thus enhancing the paste stability and injectability of the paste. Although an acidic aqueous paste comprising a higher amount of humectant provides greater injectability, this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when a humectant is used in the acidic aqueous paste, it must be present in an optimal level. [0082] Examples of a humectant which can be used in the present invention, without limitation, are glycerol, propylene glycol, glycol triacetate, sorbitol, lactic acid, and urea. The most preferred humectant is glycerol. [0083] With respect to the amount of the humectant, it may be present in the acidic aqueous paste in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the acidic aqueous paste. Water [0084] The amount of water present in the acidic aqueous paste may be between about 10 w/w % and about 30 w/w %, more preferably between about 15 w/w % and about 25 w/w %, based on the total weight of the aqueous paste. Alkaline Non-Aqueous Paste [0085] In a preferred embodiment, the alkaline non-aqueous paste composition comprises at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant, and solvent. Basic Calcium Phosphate Mineral [0086] The basic calcium phosphate mineral is, preferably, β-tricalcium phosphate, α-tricalcium phosphate, tetracalcium phosphate, oxyapatite, hydroxyapatite or calcium-deficient hydroxyapatite. The most preferred at least one basic calcium phosphate mineral is tetracalcium phosphate (TTCP). [0087] In another preferred embodiment, the mean particle size of at least one basic calcium phosphate mineral is between about 0.4 μm to about 200 μm, preferably between 2 μm to about 90 μm, and more preferably 30 μm to about 70 μm, and most preferably 45 μm to about 55 μm. [0088] In another embodiment wherein the alkaline non-aqueous paste contains bimodal distribution of TTCP, the mean particle size of the first set of TTCP is preferably between 2 μm to about 60 μm, more preferably between 10 μm to 30 μm, and the mean particle size of the second set of TTCP is between 10 μm to 90 μm, more preferably between 25 μm to 60 μm. [0089] With respect to an amount of the basic calcium phosphate mineral present in the alkaline non-aqueous paste, it may be present in an amount of between about 1% w/w and about 90% w/w, and preferably about 10% w/w and about 80% w/w based on the total weight of the alkaline non-aqueous paste. [0090] In the most preferred embodiment wherein the alkaline non-aqueous paste contains TTCP, the TTCP may be present in an amount of between about 40% w/w and about 90% w/w, more preferably between about 60% w/w and about 80% w/w based on the total weight of the alkaline non-aqueous paste. Paste Stabilizing Agent for the Alkaline Non-Aqueous Paste [0091] The paste stabilizing agent in accordance with the present invention can be any material useful for stabilizing the alkaline non-aqueous paste to prevent or retard an unwanted alteration of the physical state, such as separation of the powder components from the liquid components even after the paste is exposed to gamma radiation for terminal sterilization. [0092] With respect to the alkaline non-aqueous paste, Applicants have surprisingly found that the use of either the natural or synthetic polymers does not affect the non-aqueous paste's long term storage stability even after it is exposed to the terminal sterilization process, such as gamma irradiation. [0093] Without wishing to be bound by a theory, it is believed that when a paste stabilizing agent, such as PEG and/or cellulose polymers are dissolved in non-aqueous solvents such as glycerol or propylene glycol, a complex hydrogen bond network is formed in which the TTCP particles are suspended, thereby making the paste storage stable for a long term. [0094] Examples of a paste stabilizing agent which can be used in the alkaline non-aqueous paste, without limitation, synthetic polymer such as PEG or a natural cellulose-based polymer, such as hydroxyethylcellulose (HEC), ethylcellulose, methylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose. The most preferred paste stabilizing agent for the alkaline non-aqueous paste is PEG and HEC when preferentially using an antioxidant such as thioglycerol. [0095] The mean molecular weight (Mw) of the PEG in the alkaline non-aqueous paste is between about 1,000 Mw to about 60,000 Mw, preferably between about 5,000 Mw to about 40,000 Mw, more preferably between about 10,000 Mw to about 40,000 Mw, but most preferably between 15,000 Mw to about 25,000 Mw. [0096] With respect to the amount of the PEG in the alkaline non-aqueous paste, the PEG may be present in an amount of between about 0% w/w and about 20% w/w, more preferably between about 0.5% w/w and about 10% w/w, but most preferably between 1% w/w to 5% w/w based on the total weight of the paste. [0097] The mean molecular weight (Mw) of the HEC in the alkaline non-aqueous paste is between about 90,000 Mw to about 1,500,000 Mw, preferably between about 1,000,000 Mw to about 1,400,000 Mw. [0098] With respect to the amount of the HEC present in the alkaline non-aqueous paste, the HEC may be present in an amount of between about 0% w/w and about 5% w/w, more preferably between about 0% w/w and about 1% w/w, but most preferably 0% w/w to 0.5% w/w based on the total weight of the paste. Surfactant [0099] The surfactant in accordance with the present invention can be any material useful for preventing coagulation of colloidal particles by helping particles suspend in liquid and to reduce the surface tension of the basic calcium phosphate mineral in the alkaline non-aqueous paste. [0100] The surfactant of the present invention may be supplied in only the one of the at least two pastes, or in some or all of the at least two pastes. However, in a preferred embodiment where there are two pastes in a system containing acidic aqueous paste and alkaline non-aqueous paste, the surfactant is in the alkaline non-aqueous paste only. [0101] Examples of a surfactant which can be used in the present invention, without limitation, are glycerol monostearate, lecithin, phospholipids, glycerol distearate, polyethylene glycol distearate, block polymers of PEG-PPG-PEG or PPG-PEG-PPG, Tween, Span, any polysorbate fatty acid ester or polysorbate monooleate (from oleic acid) or sorbitol esters. The most preferred surfactant is polysorbate 80. [0102] With respect to the amount of the surfactant, it may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the total formulation when at least two pastes are combined. [0103] In a preferred embodiment of the present invention, the surfactant may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the acidic aqueous paste containing MCPM and DCPA; and the reaction retarding agent may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the alkaline non-aqueous paste containing TTCP. Solvent in Alkaline Non-Aqueous Paste [0104] The solvent for the alkaline non-aqueous paste can be any suitable non-aqueous liquid at room temperature, which excludes water. Examples of the solvent for the alkaline non-aqueous paste in accordance with the present invention, without limitation, are glycerol, ethanol, propanol, and propylene glycol. The preferred solvent is glycerin and propylene glycol due to their biocompatibility and complete miscibility with water. [0105] The non-aqueous liquid solvent in the alkaline non-aqueous paste may be present in an amount of between about 10 w/w % and about 40 w/w %, more preferably between about 20 w/w % and about 30 w/w %, and most preferably between about 22 w/w % and about 28 w/w %, based on the total weight of the alkaline non-aqueous paste. Additive(s) [0106] Various additives may be included in the inventive cements, slurries and pastes to adjust their properties and the properties of the hydroxyapatite products made from them. For example, proteins, osteoinductive and/or osteoconductive materials, X-ray opacifying agents, medicaments, supporting or strengthening filler materials, crystal growth adjusters, viscosity modifiers, pore forming agents, and other additives and a mixture thereof may be incorporated without departing from the scope of this invention. [0107] The nature of the compounds and functional materials present in the cements is not limited to the heretofore described ingredients, but to the contrary any other suitable osteoconductive, bioactive, bioinert, or other functional materials may be used in conjunction with the invention. When used, these optional ingredients may be present in any amounts suitable for their intended purposes. For instance, particularly in the case of the calcium phosphate cements, one or both cement precursor phases may include a setting accelerator, such as phosphoric acid, hydrochloric acid, sulfuric acid, oxalic acid, and salts thereof, and sodium phosphate, potassium phosphate, and sodium fluoride. In some embodiments, some of the calcium phosphate materials themselves may promote setting; for instance, MCPM and certain nano-sized calcium phosphate materials may promote setting of the cement. Any other suitable setting accelerator may be used in conjunction with the present invention. Setting accelerators are described in more detail in Chow et al., U.S. Patent Application Publication No. 2005/0074415, published Apr. 7, 2005. [0108] In some embodiments, one of the cement precursors includes an osteoinductive protein, by which is contemplated any protein that is useful in assisting in or inducing bone formation. Osteoinductive proteins are deemed particularly suitable for use in conjunction with the carboxyl/calcium cement systems because, at least for many known osteoinductive proteins, such proteins may denature at an alkaline pH. [0109] Another optional ingredient is a filler, such as a radiopaque filler. The radio opaque filler may, for instance, be a suitable bismuth, barium, or iodide compound, such as barium sulfate or bismuth hydroxide. Other suitable fillers include bioglass, silica based, alumina based, biphasic calcium phosphate, calcium silicate, calcium sulfate, granular calcium phosphate ceramics, and the like. [0110] A medicament, such as zinc, magnesium, strontium, boron, copper, silica or any other suitable medicament may be included in one or both of the phases of the cement precursors. [0111] Either or both of the phases may include a material that is intended to affect the viscosity, cohesiveness, or injectability of the phases. Any suitable biocompatible ingredient. [0112] In some embodiments, a macropore forming material may be used. As disclosed, for instance, in prior U.S. Pat. Nos. 7,018,460 and 6,955,716, a macropore forming material, such as mannitol, is useful in forming a macropores, or pores having a size greater than 150 microns. Such pores are sometimes deemed desirable and that they create a structure that may be useful in promoting growth of soft tissue in or near the region of these cements. [0113] Also as described in U.S. Pat. Nos. 7,018,460 and 6,955,716, in some embodiments, one or more strength-enhancing components, such as fibers, meshes, or the like, may be used. Such components may be resorbable or non-resorbable. EXAMPLES [0114] Several formulations in accordance with the present invention were made as illustrated below in Examples 1, 2 and 3. A table of abbreviations used in Examples 1, 2 and 3 is provided below. [0000] Abbreviations PEG = Polyethylene Glycol MCPM = Monocalcium Phosphate Monohydrate DCPA = Dicalcium phosphate Anhydrous TTCP = Tetracalcium Phosphate CAM = Citric Acid Monohydrate SPM = Sodium Phosphate Monobasic Span 80 = Sorbitan Monooleate Tween 80 = Polysorbate 80 HEC = Hydroxyethylcellulose TSCD = Trisodium Citrate Dihydrate Example 1 [0115] [0000] Mean Particle Size Paste % (μm)/Mean Molecular Type Material w/w Weight (Mw) Acidic MCPM 11.60 40-60 μm Aqueous DCPA 58.04 1-12 μm Paste Water (WFI) 18.59 Citric Acid Monohydrate 7.45 PEG 1.21 20k Mw Glycerol 1.33 PVP 1.78 58k Mw TOTAL 100.00 Alkaline TTCP 57.63 10-30 μm Non- TTCP 14.12 30-80 μm aqueous Propylene Glycol 24.86 Paste Tween 80 1.13 PEG 2.26 20k Mw TOTAL 100.00 Example 2 Examples of Various Acidic Aqueous Pastes [0116] [0000] Formulation Paste Mean Particle size Family Weights (μm)/Mean Molecular Reference Material (grams) weight (Mw) A MCPM 10.28 40-60 μm DCPA 51.42 1-12 μm Water 17.38 TSCD 0.95 150-220 μm CAM 6.96 Glycerol 0.36 PEG 0.93 20K Mw B MCPM 10.00 40-60 μm DCPA 50.00 1-12 μm Glycerol 0.36 SPM 0.5 Water 15.02 CAM 6.01 PEG 1.43 20k Mw PVP 3.47 58k Mw C MCPM 10.00 40-60 μm DCPA 50.00 1-12 μm Glycerol 1.2 SPM 25.0 Water 16.01 CAM 6.41 PEG 1.66 20k Mw PVP 2.25 58k Mw D MCPM 10.0 40-60 μm DCPA 50.0 1-12 μm Water 19.45 CAM 7.87 HEC 0.28 1.3 × 10{circumflex over ( )}6 Mw E MCPM 11.60 40-60 μm DCPA 58.04 1-12 μm Water (WFI) 18.59 CAM 7.45 PEG 1.21 20k Mw Glycerol 1.33 PVP 1.78 58k Mw F MCPM 10.0 40-60 μm DCPA HS II 54.98 1-12 μm SPM 0.5 Water 40.0 CAM 14 G MCPM 10.0 40-60 μm DCPA HS II 50.0 1-12 μm Phosphoric Acid 0.5 85% Water 100.0 CAM 40.04 PVP C30 14.0 Example 3 Examples of Various Alkaline Non-Aqueous Pastes [0117] [0000] Formulation Paste Mean Particle size/ Family Weights Mean Molecular Reference Material (grams) weight (Mw) A1 TTCP 48.0 10-30 μm TTCP 12.0 30-80 μm Propylene Glycol 20.93 Span 80 0.92 PEG 1.84 20k Mw B1 TTCP 48.0 10-30 μm TTCP 12.0 30-80 μm Propylene Glycol 20.93 Tween 80 0.92 PEG 1.84 20k Mw C1 TTCP 60.0 10-30 μm Propylene Glycol 22.67 HEC 0.33 1.3 × 10{circumflex over ( )}6 Mw D1 TTCP 57.63 10-30 μm TTCP 14.12 30-80 μm Propylene Glycol 24.86 Tween 80 1.13 PEG 2.26 20k Mw E1 TTCP 48.0 10-30 μm TTCP 12.0 30-80 μm Glycerol 9.0 PEG 10.0 20k Mw Triacetin 90.0 [0118] The dual pastes containing precursor for bone cement of the present invention were subjected to an array of qualification tests to verify that they meet the performance requirements. The dual pastes system of the present invention was analyzed for long term stability. [0119] Long term stability may be measured by any technique or using any criteria deemed appropriate. In accordance with one such technique, a sample of the material or materials constituting the paste is first gamma irradiated and put in a accelerated aging chamber which is heated to a temperature of 40° C. at a relative humidity of 75%, and held at this temperature for a set period of time. The acidic aqueous paste and the alkaline non-aqueous paste then are mixed to form a cement, and the setting time of the cement is evaluated as compared with the original setting time of a similar cement made without thermal treatment of either of the pastes. If the setting time of the cement made with the thermally treated phase is approximately equal to the setting time of the similar cement, the paste may be deemed suitably stable for use in conjunction with the present invention. The invention is not limited to cement precursor systems that meet this criterion; rather, the foregoing is provided to illustrate one of but many possible methods for evaluating stability. [0120] In the present case, the pastes illustrated in Examples 1, 2 and 3 were first sterilized using gamma radiation and put in an accelerated aging test chamber. Subsequently, the acidic aqueous paste and the alkaline non-aqueous paste were mixed to form a bone cement and the resulting bone cement was tested for (1) aging stability, (2) wet field penetration resistance, (3) compression strength and (4) injectability, which are described in more details below. Gamma Irradiation [0121] Irradiation dose ranging between 25-35 kGy was used to sterilize the pastes of Examples 1, 2 and 3 following the protocol of ISO 11137-2, disclosure of which is incorporated by reference herein. The irradiation dose mentioned above is merely a preferred range, and that the irradiation dose should not be limited to the range mentioned above, but should be selected such that it is sufficient to sterilize while the adverse effects such as degradation, loss of stability, loss of efficacy of the pastes, etc. are minimal. [0122] After the exposure to gamma irradiation for sterilization, the pastes were tested both pre-aged and post-aged after being put in the accelerated aging test conditions for a predetermined period of time as explained below. Aging Test [0123] The aqueous and alkaline non-aqueous pastes as described in Examples 1, 2 and 3 above were analyzed for long-term stability. [0124] The various pastes were packaged in an air and moisture impermeable double barreled syringe system and were placed in a climatic oven set at an ambient temperature of 21° C. and aged for a set period of time. [0125] After the exposure in the aging test conditions for a predetermined period of time, the pastes were analyzed to assess the dual pastes' stability and cement performance. A successful outcome in terms of paste stability was considered achieved when the aged paste test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicated no detectable degradation of the paste system over time under the test conditions used. The results are presented in Table A below. Dispersion Analysis; LUMiSizer Testing [0126] The cements were produced as described in Examples 1, 2 and 3, were exposed to gamma radiation for sterilization and were tested for stability via dispersion analysis by use of LUMiSizer analysis. Approximately 0.5 ml of the paste to be tested was filled into a clean LUMiSizer vial to the predefined line on the vial. The vial was then sealed with the supplied screw cap lid and this sealed vial was then placed into the LUMiSizer and secured. The dispersion analysis test can now be performed and run to completion. The output from this test method displays the dispersion of the paste system in relation to time over a specific gravity applied onto the paste via centrifugal force. This dispersion data can be used to indirectly correlate the stability of the paste system and used for comparative purposes between various paste systems. A successful outcome in terms of paste stability was considered to be achieved when the aged paste dispersion test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicated no detectable degradation of the paste system over time under the test conditions used. FIG. 1 is an overview to dispersion analysis results generated for various formulations that were tested at various time points (0, 1, 3, 7, 14, 15, 21 and/or 28 days respectively). Wet Field Penetration Resistance Test [0127] The cements produced as described in Examples 1, 2 and 3, which were exposed to gamma radiation for sterilization and the accelerated aging conditions, were tested for wet field penetration resistance. The test consists of applying a load applicator through the cement at specific time points. The load applicator was made up of a small cylindrical stainless steel needle with 1/16″ in diameter. Immediately after initial mixing of the acidic aqueous paste and alkaline non-aqueous paste, the cement composition was deposited into a long groove (¼″ wide×¼″ deep) of a block heated at 32° C. One minute after the initial mixing, the cement was subjected to a constant flow of saturated phosphate solution using a Watson Marlow 323 peristaltic pump set at 20 rpm. The solution was kept constant at 32° C. Ten minutes after the initial mixing, the load applicator was made to penetrate the cement for 1.27 mm and the result force was recorded. Table A below shows the results of the penetration resistance tests using the bone cements produced according to Examples 1, 2 and 3. FIG. 2 is a graphical overview of the analysis results of wet field tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. This wet field penetration resistance test result can be considered having a successful outcome in terms of demonstrating paste stability as can be seen from this figure that the aged paste penetration test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero with no statistically significant difference shown (p>0.05). Such a result indicates no detectable degradation of the paste system over time under the test conditions used. [0000] TABLE A Test Method Formulations Wet Inject- Compression @ Acidic Alkaline Non- Field ability 4 hr post Aqueous Aqueous (MPa) (N) mixing (MPa) D PRE-AGED C1 PRE-AGED 28.1 25.0 7.2 D Aged C1 Aged 39.0 50.0 7.08 A PRE-AGED C1 PRE-AGED 31.74 86.5 6.03 A Aged C1 Aged 28.65 77.7 6.65 B PRE-AGED C1 PRE-AGED 24.85 99.0 4.0 B Aged C1 Aged 22.78 111.0 4.03 C PRE-AGED A1 PRE-AGED 27.12 60.5 5.54 C Aged A1 Aged 19.43 65.5 5.51 C PRE-AGED B1 PRE-AGED 23.59 66.9 5.74 C Aged B1 Aged 17.01 65.9 5.79 E PRE-AGED D1 PRE-AGED 25.36 88.72 E Aged D1 Aged 23.85 82.03 Injectability Test [0128] The cements produced as described in Examples 1, 2 and 3, which were exposed to gamma radiation for sterilization and the accelerated aging conditions, were also tested for injectability. A dual barrel syringe containing the combination of paste systems as described in Table above are placed in a test rig in a Tinius Olsen Tensometer electro-mechanical testing machine. The start of the test is T=0. Once the plunger reaches the set preload (5N), it displaces at a rate of 25 mm/min until the required extension is reached (15 mm). Once the 20 seconds wait has elapsed, the test resumes until a total displacement of 30 mm is reached unless a maximum load of 300N is reached first. This ‘stop-start’ function is required to provide the user with a flexibility in usage of the dual paste system with an injectability window. [0129] For this test, maximum initial injectability force shall not exceed 225N, more preferably 150N for both the initial injectability as well as re-starting after stopping injection for 20 sec. The results are recorded in the Table A above. FIG. 3 is a graphical overview of the analysis results of wet injectability tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. This test result can be considered having a successful outcome in terms of demonstrating paste stability as can be seen from this figure that the aged paste injectability test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicates no detectable degradation of the paste system over time under the test conditions used. The injection force to enable the evaluation of ease of injectability can be obtained from ANSI/AAMI HE75:2009 (p. 367, FIG. 22.13) whereby 95% of males and 50% of females can squeeze up to 107N over a grip span range from 4.5 cm to 11 cm. Compression Test [0130] The cements produced as described in Examples 1, 2 and 3 were also tested for compressive strength. A set amount of the dual paste system (as listed in Table A) is injected into a cylindrical mould to form a set cement shape of diameter 6 mm and 12 mm length. The mould is then placed in Phosphate Buffered Saline (PBS) solution and the cement is allowed to set in this mould. Remove the set cement at a 4 hrs time point after incubation in PBS. [0131] Measure the diameter and length of each specimen before separately placing each sample to be tested on the Tinius Olsen Tensometer electro-mechanical testing machine, ensuring that the load rate is set at 1 mm/min. Record the maximum load at which the cylindrical sample fails under compressive loading. The results are recorded in the Table A above.

The present invention relates to a bone cement precursor system that is presented in the form of two shelf-stable pastes which have been terminally sterilized and are held in separate containers during product transport and storage. When the product is used during surgery, these pastes inject to a site of application through a static mixing device by the action of applied injection force. When the two pastes are mixed, they start to react to each other while injecting out. The resulting composition is highly biocompatible, osteoconductive, injectable, rapid setting and bioresorbable, and is useful in connection with bone repair procedures, for example, in the craniomaxillofacial, trauma and orthopedic areas.

ORIGIN OF THE INVENTION The United States Government has rights in this invention pursuant to Contract No. DE-AC04-76DP00789 between the United States Department of Energy and AT&T Technologies, Inc. BACKGROUND OF THE INVENTION This invention relates generally to apparatus for pumping liquid metal and more particularly to an electric pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. Pumps for liquid metals are generally known and include not only electromagnetic and mechanical pumps, but also pumps of the type whereby the metal is electrolyzed through a liquid electrolyte barrier. While electromagnetic pumps include simplicity, the lack of moving parts, and a moderate pressure and temperature capability, mechanical pumps normally have a relatively high pressure capability and high efficiency. However, neither of these types of pumps is capable of both high pressure and high temperature operation. The electromagnetic pump is limited to moderate pressures by the practical magnitudes of electrical current and magnetic-field strength. It is further limited in temperature by the materials used to produce the magnetic field. The magnetic circuit also imposes severe weight penalties. Typical examples of electromagnetic pumps include those shown and described in: U.S. Pat. No. 3,885,890, "Electromagnetic Pumps", Davidson, and U.S. Pat. No. 4,765,948, "Coolant Circulation System For A Liquid Metal Nuclear Reactor", DeLuca et al. Mechanical pumps driven by electric motors are also subject to temperature limits and weight penalties imposed by the motor. Where liquid metals are electrolyzed through a liquid electrolyte barrier, pumping pressure is limited to the small hydrostatic pressure that naturally occurs across the electrolyte. Examples of the liquid electrolyte type pump include U.S. Pat. No. 3,591,312, Liquid Mercury Flow Control and "Measuring System", Eckhardt and U.S. Pat. No. 3,600,104, "Method And Apparatus For Controlled Pumping Of Liquid Mercury", King. SUMMARY It is an object of the present invention, therefore, to provide an improved liquid metal electric pump. It is another object of the invention to provide a liquid metal electric pump which is capable of both high pressure and high temperature operation. It is still another object of the invention to provide a liquid metal electric pump which is simple in construction and having no moving mechanical parts. It is yet another object of the invention to provide a liquid metal pump which requires no magnetic field and can be fabricated entirely of high temperature materials. Briefly, the foregoing and other objects are achieved by a liquid metal electric pump particularly adapted for high temperature, high pressure applications comprised of a pump body having a liquid inlet port and a liquid outlet port and a non-porous solid electrolyte membrane of a predetermined type for the liquid metal being pumped with the membrane being located in said pump body and separating the inlet and outlet ports. Upon the application of a DC voltage across the non-porous solid electrolyte membrane, ions are formed and enter the membrane at the electrically positive surface of the membrane where they pass therethrough and are neutralized on the opposite or negative surface thereof. This causes a pumping action of the liquid metal to be provided without any moving parts. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated into and form a part of the specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are provided only for the purpose of illustrating a preferred embodiment of the invention and are not to be construed as limiting the invention. FIG. 1 is a schematic illustration of a basic embodiment of the invention; FIG. 2 is a central transverse cross section of a relatively flat compact embodiment of the invention incorporating a flat electrolyte membrane; and FIG. 3 is a central transverse cross section of an embodiment of the invention having a domed electrolyte membrane. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein like reference numerals refer to like parts throughout, attention is first directed to FIG. 1 where reference numeral 10 denotes a pump body or housing having a liquid metal inlet port 12 and a liquid outlet port 14. The configuration shown in FIG. 1 is a basic representation of the inventive concept where there is located a solid non-porous electrolyte membrane 16 voltage across pump body 10 to separate the inlet port side 20 from the outlet port side 22 of the pump body. Liquid metal 18 is pumped from the inlet port side 20 to the outlet port side 22 when an electric voltage is applied across the electrolyte membrane 16. As shown, a source of variable DC voltage 24 is coupled across the membrane 16 such that the positive polarity terminal is connected to the inlet port side 20, while the negative polarity terminal is connected to the outlet port side 22. It is significant to note that the principal element in the liquid metal pump shown in FIG. 1 is the solid electrolyte membrane 16 which is non-porous and selected to be specific to the liquid metal that is to be pumped that is, it is of a predetermined type dependent upon the type of liquid metal being pumped. For example, where liquid sodium comprises the liquid metal 18, the membrane 16 is comprised of sodium beta'' alumina. This particular material is an excellent sodium-ion conductor while being a very good electric insulator. Accordingly, when an electrical voltage from the source 24 shown in FIG. 1 is applied across the thickness of the membrane 16, sodium-ions will form and pass through the membrane from the electrically positive surface 26, where they exit from the opposite electrically negative surface 28 and are neutralized. Since the membrane 16 is not porous, the movement of ions therethrough occurs as the result of along specific crystal planes as opposed to movement through a porous membrane such as taught by U.S. Pat. No. 3,923,426 where the flow is viscous. When there is no differential pressure across the membrane 16, the applied voltage thereacross will be substantially equal to the product of the sodium-ion current and the ionic resistance of the membrane. When a differential pressure occurs across the membrane, however, an additional applied voltage from the source 24 will be necessary to maintain the original ion flow. This additional voltage can be approximated by the product of the molar specific volume of the liquid metal at the operating temperature of the pump and the pressure differential across the membrane. The magnitude of the specific volume is such that generally very large pressures can be sustained with relatively small applied voltages. For example, at 880° C., a 9-atmosphere static pressure differential requires the application of only 0.26 millivolts. For many liquid metals, particularly sodium and potassium, solid electrolyte ceramics are currently known that can survive extremely high temperatures and are thus suitable for use. With respect to mercury, a ceramic solid electrolyte is also contemplated. The solid electrolyte membrane 16 can be sealed to the pump housing or body using refractory metal foil transition sections and active metal brazing techniques as will be disclosed with respect to the embodiments of FIGS. 2 and 3. Referring now to FIG. 2, shown thereat is a relatively flat compact embodiment wherein the pump housing, identified by reference numeral 10' is generally of a circular cylindrical configuration and includes symmetrical upper and lower half-body members 30 and 32 comprised of metal and mutually facing projecting side rim portions 34 and 36 between which is located a generally annular separator 38 comprised of electric insulating material. Located between the body members 30 and 32, in line with the insulator member 38, is a non-porous solid electrolyte membrane identified by reference numeral 16' which is in the shape of a flat plate or disk. The membrane 16' is supported by a support grid 40 which is attached to a metallic backing member 42. The purpose of the support grid 40 and the backing member 42 is to limit pump pressure induced tensile stresses in the electrolyte membrane 16'. Further as shown in FIG. 2, the opposite faces 26 and 28 of the electrolyte membrane 16' are mechanically connected to the opposing metal halves 30 and 32 by means of a pair of flexible metal seals 44 and 46, which extend around the rim of the housing portions 34 and 36 to seal off the inner cavity portions 48 and 50 of the pump body 10' which connect to a tubular inlet port 12' and a tubular outlet port 14', respectively, located along the central circular axis 52. A pair of electrical terminals 54 and 56 are additionally shown connected to the metal pump body members 30 and 32 so that a DC supply voltage, not shown, can be coupled thereacross, to provide a pumping action from the inlet port 12' to the outlet port 14' when face 26 of the membrane is of a positive polarity and the face 28 is of a negative polarity. In many instances, in the embodiments of FIGS. 1 and 2, natural means, such as orientation and gravity, can be used to provide the required liquid metal, which acts as the electrical contact, to the solid electrolyte membrane 16'. Otherwise, porous electrodes and wicking structures can be used on one or both sides of the membrane for these purposes. Referring now to FIG. 3, shown thereat is an embodiment of the invention ,which uses a rigid, non-porous solid electrolyte membrane 16'' in the shape of a hemispherical dome which is located between upper and lower metallic pump body members 60 and 62. The body members 60 and 62 are generally cylindrical in configuration and have respective inlet and outlet ports 12' and 14' aligned along the central circular axis 52 in the same manner as the embodiment shown in FIG. 2. The upper body member 60, however, is relatively larger in size than the lower body member 62 to accommodate the domed structure of the electrolyte membrane 16'' so that its convex surface 64 faces the upper cavity portion 66 while the conical surface 68 faces the lower cavity portion 70 which also includes a portion of the cavity formed by an upwardly projecting rim segment 72 of the lower pump body member 62. The upper body member 60 additionally includes an inwardly projecting rim portion 74 which results in two mutually opposing flat surfaces 76 and 78 being formed for contacting an annular insulator member 79. The semi-circular dome shaped membrane 16'' is mounted between the two body members 60 and 62 via a pair of resilient metallic seal elements 80 and 82 which are bonded to the portions 72 and 74 of the lower and upper members 62 and 60, in the same fashion as shown in FIG. 2 and which operate to provide a seal between the upper and lower cavities 66 and 70. DC voltage across surfaces 64 and 68 is provided by voltage terminals 54 and 56 which are connected to the pump body members 60 and 62. Electrical connection from the pump body members 60 and 62 to the surfaces 64 and 68 is accomplished by the liquid metal being pumped. In both embodiments shown in FIGS. 2 and 3, the operation is the same as that described with respect to FIG. 1 in that application of a DC voltage across the respective non-porous solid electrolyte membranes 16' and 16'' causes ions to be formed on the inlet side surface, which is of a positive polarity, and these ions pass through the respective membranes 16' and 16 '' where they are neutralized on the opposing negative surface, causing a pumping action of the liquid metal to be provided from the inlet port 12' to the outlet port 14'. When desirable, the domed membrane structure shown in FIG. 3 can be elongated in the form of a cylindrical tube which would then require the upper and lower body members 60 and 62 to be likewise elongated to accommodate the configuration of the membrane 16''. As shown, the embodiment in FIG. 3 includes a high pressure zone which is on the convex side of the electrolyte membrane 16'' in cavity 66, as opposed to the cavity 70 so that the electrolyte would be in a compressible stress state. The pump housings 10' and 10'' shown in FIGS. 2 and 3 can be fabricated from a wide variety of high temperature liquid-metal resistant alloys. The same may be said for the membrane support grid and backing elements 40 and 42 shown in the flat plate embodiment of FIG. 2. Because magnetic materials and/or electrical motors or windings are not required, the operating temperature of a device in accordance with the subject invention is limited only by the construction materials utilized. Accordingly, the invention has many diverse uses including commercial, military and space applications where a simple, light, durable, high-temperature and high pressure liquid metal pump is required. Having thus shown and described what are the presently preferred embodiments of the subject invention, it should be noted that the same has been made by way of illustration. Accordingly, it is intended that the appended claims cover all alterations, modifications, and changes coming within the spirit and scope of the invention.

An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other.

FIELD OF THE INVENTION [0001] The present invention relates to a mobile delivery platform for flowable explosive. BACKGROUND OF THE INVENTION [0002] Flowable explosive, such as emulsion explosive, is conventionally delivered in surface and underground applications using gravity tanks. Gravity tanks have a high centre of gravity and are not easily transportable. They also require a top access structure for cleaning and maintenance of the inside walls to prevent crystallization of the emulsion explosive. The top access structure limits tank capacity and is a fall hazard for workers. [0003] A need therefore exists for a mobile, self-cleaning delivery platform for flowable explosive. SUMMARY OF THE INVENTION [0004] According to the present invention, there is provided apparatus for storing and dispensing flowable explosive, the apparatus including an explosive pump for pumping flowable explosive into an explosive tank having a fluid pressure-actuated piston movable therein for expelling flowable explosive out of the explosive tank through a delivery hose fitted with an injector through which one or more additives from one or more additive tanks can be pumped by an additive pump. [0005] The explosive tank and the piston therein can be cylindrical with a common horizontal longitudinal axis. [0006] The piston can have one or more circumferential seals for cleaningly wiping the inner surface of the explosive tank. [0007] The piston can be a concave piston that is radially expandable to sealingly engage the inner surface of the explosive tank. [0008] The explosive tank can have a detector therein for detecting displacement of the piston and/or monitoring quantities of flowable explosive in the explosive tank. [0009] The one or more additives can be lubricant stored in a lubricant tank, and explosive additive stored in an explosive additive tank. [0010] The delivery hose can be wound on a hose reel. [0011] The tanks, pumps, and hose reel can be arranged on a transportable platform. [0012] The flowable explosive can be selected from emulsion explosive, gel explosive, slurry explosive, blended explosive, and doped explosive. [0013] The present invention also provides a method of delivering flowable explosive using the above apparatus. BRIEF DESCRIPTION OF THE DRAWINGS [0014] The invention will be further described by way of example only with reference to the accompanying drawings, in which: [0015] FIG. 1 is a schematic diagram of fluid circuit of an embodiment of a mobile delivery platform for flowable explosive of the invention; and [0016] FIG. 2 are side, plan and end view of the mobile delivery platform. DETAILED DESCRIPTION [0017] Referring to the FIG. 1 , an embodiment of a mobile delivery platform 26 for flowable explosive generally includes an explosive tank 1 , an explosive pump 10 , an additive pump 14 , an explosive additive tank 15 , a lubricant tank 16 , and a delivery hose 23 wound on a hose reel 22 . Referring to FIG. 2 , these components are arranged together on a transportable platform 24 , for example, a multimodal transport platform with International Standards Organization (ISO) standardised multimodal attachments or fittings. [0018] The explosive tank 1 is cylindrical and is made, for example, of a corrosion resistant or a suitable pressure vessel material. The explosive tank 1 has a capacity, for example, of 3 tonne. A cylindrical piston 6 is axially movable inside the explosive tank 1 . The explosive tank 1 and piston 6 have a common longitudinal axis horizontal to the transportable platform 24 . The piston 6 is a concave piston that is radially expandable when pressurised to sealingly engage the inner surface of the explosive tank 6 . Two circumferential seals 7 are provided on the piston 6 . The piston seals 7 cleaningly wipe the inner surface of the explosive tank 1 during axial movement therein of the piston 6 . Together, the piston 6 and the piston seals 7 provide a “self-cleaning” action that prevents build-up of flowable explosive on the inner surface of the explosive tank 1 . Other equivalent “self-cleaning” piston and seal arrangements may also be used. The piston 6 is made of, for example, corrosion resistant material. The piston seals 7 and the delivery hose 23 are made of, for example, rubber. Together, the piston 6 and piston seals 7 sealingly divide the explosive tank 1 into opposed pressure and explosive ends. [0019] The pressure end of the explosive tank 1 is provided with an inlet manifold 5 , a pressure relief valve 2 , and a piston displacement sensor 4 . The pressure inlet manifold 5 includes a pressure regulator and a pressure gauge. The piston displacement sensor 4 is, for example, a laser detector. [0020] The explosive end of the explosive tank 1 is provided with a pressure relief valve 3 and a selector valve 8 to control flow of flowable explosive to and from an inlet/outlet port in the explosive tank 1 . The flowable explosive is, for example, emulsion explosive, gel explosive, slurry explosive, blended explosive, doped explosive, etc. The flowable explosive has a viscosity of between around 20,000 and 90,000 centipoise (cP), for example, 40,000 cP. [0021] Flowable explosive is drawn from an external supply (not shown) via selector valves 9 , 18 by the explosive pump 10 and pumped via selector valves 11 , 8 into the explosive end of the explosive tank 1 . This displaces the piston 6 backwardly toward the pressure end of the explosive tank 1 . The backward displacement of the piston 6 is monitored by the piston displacement sensor 4 . The pressure relief valve 2 acts as a bleed valve to maintain backpressure against the piston 6 so that it is positively retained next to flowable explosive pumped into the explosive tank 1 . A flow meter 12 is connected to the explosive pump 10 to indicate the flow rate of flowable explosive pumped into the explosive tank 1 . The explosive pump 10 is, for example, a high pressure diaphragm pump. [0022] Flowable explosive is discharged from the explosive tank 1 via the selector valves 8 , 11 to the delivery hose 23 by applying fluid pressure to the piston 6 via the pressure inlet manifold 5 . The fluid pressure is, for example, air pressure from a source of compressed air, for example, a truck compressed air system. The air pressure displaces the piston 6 forwardly toward the explosive end of the explosive tank 1 . The forward displacement of the piston 6 is monitored by the piston displacement sensor 4 . The discharge pressure of flowable explosive is indicated by a pressure meter 13 . The delivery hose 23 is unwound from the hose reel 22 and positioned to deliver the flowable explosive from the explosive tank 1 to a surface or underground delivery site, for example, a blast hole. The delivery rate of the flowable explosive is, for example, up to around 1100 litres per minute. The flowable explosive is substantially fully discharged from the explosive tank 1 by the piston 6 as the “self-cleaning” action of the piston 6 and the piston seals 7 leaves less than around 0.05% by weight of the initial load of flowable explosive remaining in front of the piston 6 . [0023] The pressure required to discharge flowable explosive is selectively reduced by injecting flowable lubricant stored in the lubricant tank 16 into the delivery hose 23 . The lubricant is, for example, water, oil, polymeric lubricant, etc. The flowable lubricant is pumped from the lubricant tank 16 via selector valve 17 by the additive pump 14 to an injector 19 fitted to the delivery hose 23 . The pressure and flow rate of lubricant injected into the delivery hose 23 are respectively indicated by a flow meter 20 and a pressure meter 21 . The additive pump 14 is, for example, a piston pump. The lubricant tank 16 is filled with flowable lubricant via a filler or from an external source (not shown) via the selector valves 9 , 18 . Lubricant, such as water, is selectively pumped by the additive pump 14 from the lubricant tank 16 through the explosive pump 10 for cleaning the explosive pump 10 , injector 19 and delivery hose 23 after flowable explosive has been discharged from the explosive tank 1 . A check valve between the lubricant tank 16 and the selector valve 18 prevents backup of water into the lubricant tank 16 during cleaning. [0024] Explosive additive stored in the explosive additive tank 15 is selectively injectable into the delivery hose 23 by the additive pump 14 via the selector valve 17 . The explosive additive is, for example, gassing solution. The explosive additive tank 15 is filled with explosive additive via a filler. The flow and pressure meters 20 , 21 measure the flow and pressure of explosive additive injected into the delivery hose 23 . [0025] Referring to FIG. 2 , a control panel 25 is provided at one end of the platform 24 for the flow and pressure meters 12 , 13 , 20 , 21 , a display of the piston displacement sensor 4 , and controls for the explosive pump 10 and the additive pump 14 . The selector valves can be solenoid valves having controls provided in the control panel 25 . [0026] The mobile delivery platform 26 can form part of a mobile manufacturing unit (MMU), an underground delivery system, or a plant storage unit. [0027] It will be appreciated that embodiments of the invention advantageously provide a mobile, self-cleaning delivery platform for flowable explosive. [0028] The embodiments have been described by way of example only and modifications are possible within the scope of the claims which follow.

Apparatus for storing and dispensing flowable explosive, the apparatus including an explosive pump for pumping flowable explosive into an explosive tank having a fluid pressure-actuated piston movable therein for expelling flowable explosive out of the explosive tank through a delivery hose fitted with an injector through which one or more additives from one or more additive tanks can be pumped by an additive pump.

CROSS REFERENCE TO RELATED APPLICATION This application is continuation of U.S. application Ser. No. 14/470,481, filed Aug. 27, 2014, which application was published on Jan. 15, 2015, as U.S. Publication No. US20150014358, which application claims priority to application Ser. No. 13/169,339, filed Jun. 27, 2011, which application was granted on Sep. 30, 2014, as U.S. Pat. No. 8,844,768, which applications are incorporated herein by reference in their entireties. BACKGROUND Dispensers for bulk containers of liquid dairy products are well known. Such dispensers are comprised of a refrigerated cabinet in which one or more bulk containers of dairy products are kept cold. The bulk dairy product containers typically have a flexible dispensing tube at the bottom of the container through which product is dispensed using a pinch valve. Another type of prior art dairy product dispenser uses refillable containers which also have a dispensing tube at the bottom of the container through which dairy product is controllably dispensed using a pinch valve. Prior art refillable containers have top-located openings proportional to their widths. Many dispensers are designed to be used with two or more refillable containers. Some such dispensers are designed to be used with two or more refillable containers that hold different volumes of liquid. A problem with prior art refillable containers that contain different volumes of liquid is that the openings in the tops of the refillable containers are proportional to the width of the container. When a small-volume container needs to be refilled, the liquid must be poured through an opening that is usually much smaller than the opening in large-volume containers. Refilling small-volume containers is thus more difficult than refilling large-volume containers. FIG. 1 is a perspective view of a liquid dispenser; FIG. 2 is a front elevation view of the liquid dispenser; FIG. 3A is a perspective view of the liquid dispenser showing the containers with openings; FIG. 3B is a front elevation view of the liquid dispenser; FIG. 4 is a perspective view of the center container; FIG. 5 is a cross section of the center tank taken through section line 5 - 5 ; FIG. 6 is a cross section showing an alternative embodiment of the center tank taken through section line 5 - 5 ; FIG. 7 is a perspective view of the right side container; FIG. 8 is a cross section view of the right side container taken through section line 8 - 8 ; FIG. 9 is a perspective view of the left side container; and FIG. 10 is a cross section view of the left side container taken through section line 10 - 10 . DETAILED DESCRIPTION FIG. 1 is a perspective view of a liquid dispenser 100 . The dispenser 100 is comprised of a refrigerated cabinet having a front door 104 , a top access panel 106 and a refrigerated interior compartment 108 having a width 110 to accommodate three separate liquid containers 112 , 114 and 116 . FIG. 2 is a front elevation view of the liquid dispenser 100 . A first container 112 is positioned to the left side of a center container 114 . A right side container 116 is positioned to the right side of the center container 114 . The left side container 112 has a width 202 ; the center container 114 has a larger width 204 . The right side container 116 has a width identified by reference numeral 206 . The combined widths 202 , 204 and 206 fit within the width 110 of the refrigerated compartment 108 . Each of the containers 112 , 114 and 116 has a dispensing tube 208 that extends downwardly from the container through a pinch bar of a pinch valve 210 . One example of a pinch bar and pinch valve is disclosed in the applicants co-pending patent application Ser. No. 12/885,641, filed Sep. 20, 2010, issued Feb. 19, 2013 as U.S. Pat. No. 8,376,310 and entitled Pinch Valve. The content of said application is incorporated in its entirety herein by reference. Another example of a pinch bar and pinch valve is co-pending patent application Ser. No. 13/169,305, filed Jun. 27, 2011, issued Sep. 30, 2014 as U.S. Pat. No. 8,844,768 and is entitled Liquid Dispenser Pinch Valve. The content of said application is also incorporated in its entirety herein by reference. FIG. 3A is a perspective view of the liquid dispenser 100 showing the left container 112 , the center container 114 , and the right container 116 with openings 302 , 304 and 306 in the top of the containers. Each opening 302 , 304 and 306 is provided with a corresponding cover 308 , 310 and 312 . FIG. 3B is a front elevation view of the liquid dispenser 100 also showing the containers 112 , 114 , and 116 along with the dispensing tubes 208 . The covers 308 , 310 , and 312 are open to reveal openings 302 , 304 , and 306 . FIG. 4 is a perspective view of the center container 114 . The center container 114 is one of three containers sized, shaped and arranged to fit within the width 110 of the refrigerated interior compartment 108 of the dispenser 100 . The center or middle container 114 can be seen in FIG. 4 as having a shape substantially the same as a rectangular parallelepiped or cuboid. A parallelepiped is a six-faced polyhedron all of the faces of which are parallelograms and lying in pairs of parallel planes. The center container 114 has a bottom wall or surface 400 , a back side or wall 402 , a front side or face 404 , a right side 406 , an opposing left side 407 , and a top 408 . A small cylinder 410 can be seen projecting downwardly from the bottom 400 . The cylinder 410 is a drain for the container 114 . Liquid stored in the container 114 flows through the cylinder 410 into a dispensing tube 208 into which the cylinder 410 is inserted. The cylinder 410 , which is preferably formed of the same material as the container 114 , is protected from breakage by two legs 430 that extend downwardly from the bottom 400 of the container 114 . Except for the top 408 , the container 114 is molded. The corners 412 are thus rounded imbuing the side walls 402 , 404 , 406 and 407 with an uninterrupted connection or union between them. The rounded corners 412 and the side walls 402 , 404 , 406 and 407 can thus be considered as a continuous side wall or as four separate side walls separated by the rounded corners 412 . The top 408 has incorporated within it the aforementioned opening 304 and a cover 310 . The cover 310 is hinged 416 to the top 408 by winch the cover 310 can be rotated around the hinge 416 between an opened and closed position. The opening 304 has a width 420 and a length or depth 418 . The product of the depth 418 and the width 420 is substantially equal to the open area through which a liquid can be poured into the container 114 to refill it. As used herein, the term, “substantially equal” means that in one embodiment, a cover for one opening will fit the other openings with a fit or seal, the tightness of which is substantially the same between them, regardless of the container volumes. In another embodiment, “substantially equal” means that the areas of the openings in the different containers vary by less than about ten percent (10%) regardless of the container volumes. Stated another way, one opening in one container is not more than ten percent larger or smaller than another opening in another container. In another embodiment, “substantially equal” means that the areas of the openings vary by less than about twenty percent (20%) regardless of the container volumes. One opening in one container is not more than twenty percent larger or smaller than another opening in another container. In yet another embodiment, the openings are “substantially equal” if the areas of the openings vary by less than about thirty percent (30%) regardless of the container volumes. The container 114 has a width 422 defined herein as the separation distance between the right side 406 and the left side 407 . In the embodiment shown, the right side 406 and the left side 407 are both substantially vertical and parallel to each other almost completely from the bottom 400 to the top 408 . The width is identified in FIG. 4 by reference numeral 422 . It can be seen that the width 420 of the opening 304 is less than the width 422 of the container itself 114 . The reduced width 420 of the opening 304 is due in part to an arcuate, by which is meant, curved like a bow, or an otherwise curving transition section 414 A and 414 B on the right side 406 and the left side 407 . The transition sections or transition portions reduce the width of the container 114 from its nominal width identified by reference numeral 422 to the width 420 of the opening 304 . The transition sections 414 A and 414 B of the middle container 114 thus reduce the width dimension 422 of the container at or near the top of the container 114 because the transition sections or portions are complementary to each other. The transition sections 414 A and 414 B are considered herein to be complementary because they are shaped to be mirror images of each other. By way of example, the right side transition section 414 A has a curvature that transitions or moves the right side wall 406 inwardly or toward the left side wall 407 . The left side transition portion 414 B has a curvature that moves or transitions the left side of the tank 407 inwardly or toward the right side 406 . The right side transition section 414 A and the left side transition section 414 B move the respective sides an equal distance inwardly. The transition sections are thus considered to be complements of each other. FIG. 5 is a cross section of the center tank 114 taken through section lines 5 - 5 . The transition sections 414 A and 414 B have inwardly curving sections 502 relatively straight intermediate sections 503 and outwardly curving sections 504 . The transition sections 414 A and 414 B thus have a cross-sectional shaped serpentine in nature or boustrophedonic. FIG. 6 is another cross-sectional view of the middle container 114 taken through section lines 5 - 5 , but showing an alternate embodiment of the transition sections 414 A and 414 B. In FIG. 6 , the transition sections are depicted as substantially straight lines inclined at angles 81 and 82 relative to horizontal. The relatively straight transition portions 414 A and 414 B are thus considered to be angular in shape, the term “angular” meaning forming an angle. FIG. 7 is a perspective view of the right-side container 116 . The container 116 has bottom 700 , a rear side or face 702 , a front side or face 704 , a right side 706 , a left side 707 and lop 708 . The cylinder 710 is a drain for the right side container 116 . As with the center container 114 , liquid stored in the right-side container 116 flows through the cylinder 710 into a dispensing tube 208 into which the cylinder 710 is inserted. The cylinder 710 , which is preferably formed of the same material as the container 116 , is protected from breakage by two legs 730 that extend downwardly from the bottom 700 of the container 116 . The container 116 has width measured just above the bottom 700 that is identified by reference numeral 722 . A width at the top 708 is identified by reference numeral 720 . As shown in the figure, the top width 720 is significantly greater than the bottom width 722 . The increased width at the top 720 over the bottom 722 is due to a transition portion identified by 714 . The transition portion 714 of the right side tank 116 increases the width of the container to be substantially equal to the width 420 at the top 408 of the middle container 114 . FIG. 8 is cross-sectional view of the right side container 116 taken through section lines 8 - 8 . The transition portion 714 has an outwardly curving section 802 connected to a substantially straight intermediate section 803 , which is followed by or connected to an inwardly curving section 804 . The transition section 714 for the right hand side container 116 can thus also be characterized as serpentine or boustrophedonic. Referring again to FIG. 7 , it can be seen that the opening 306 and the top 708 also has an area determined by the product of the depth 718 by the width 720 . As shown in FIG. 1 , FIG. 2 , and FIG. 3A , the area of the openings in both the center and right-hand side containers 114 and 116 , respectively, are the same which is due to the fact that the transition areas for the middle container 114 squeeze or reduce the width of that container while the transition section 714 of the right-hand container 116 enlarges or increases the width 722 of the right-hand container 116 . It can also be seen that the depth 726 of the right-hand container 116 is substantially equal to the depth 426 of the center container 114 . The top portions of both containers are thus substantially equal in as much as the width of the top 408 of the center container 114 is substantially equal to the width 720 of the top 708 of the right-hand container 116 . FIG. 9 is a perspective view of the left-side container 112 . The container 112 has a bottom 900 , a rear side or face 902 , a front side or face 904 , a right side 906 , a left side 907 and top 908 . The container 112 has width measured just above the bottom 900 that is identified by reference numeral 922 . A width at the top 908 is identified by reference numeral 920 . As shown in the figure, the top width 920 is greater than the bottom width 922 . This is a similar situation as occurs with the right side container. The increased width of the left side container at the top 920 over the bottom 922 is due to a transition portion identified by 914 . The transition portion 914 of the left side tank 112 increases the width of the container to be substantially equal to the width 420 at the top 408 of the middle container 114 . FIG. 10 is cross-sectional view of the left side container 112 taken through section lines 10 - 10 . The cylinder 910 is a drain for the right side container 112 . As with the center container 114 and the right-side container 116 , liquid stored in the left-side container 112 flows through the cylinder 910 into a dispensing tube 208 into which the cylinder 910 is inserted. The cylinder 910 , which is preferably formed of the same material as the container 112 , is protected from breakage by two legs 930 that extend downwardly from the bottom 900 of the container 112 . The transition portion 914 has an outwardly curving section 1002 connected to a substantially straight intermediate section 1003 , which is followed by or connected to an inwardly curving section 1004 . The transition section 914 for the left hand side container 112 can thus also be characterized as serpentine or boustrophedonic. Referring again to FIG. 9 , it can be seen that the opening 306 and the top 908 also has an area determined by the product of the depth 918 by the width 920 . As shown in FIG. 1 , FIG. 2 , and FIG. 3A , the area of the openings in both the center and left-hand side containers 114 and 112 , respectively, are the same which is due to the fact that the transition areas for the middle container 114 squeeze or reduce the width of that container while the transition section 914 of the left-hand container 112 enlarges or increases the width 922 of the left-hand container 112 . Again, this situation is similar concerning the right-side container. It can also be seen that the depth 926 of the left-hand container 112 is substantially equal to the depth 426 of the center container 114 . The top portions of both containers are thus substantially equal in as much as the width of the top 408 of the center container 114 is substantially equal to the width 920 of the top 908 of the left-hand container 112 . The left side container 112 is a mirror image of the right-side container 116 . Stated another way, the left-side container 112 has a width 202 near its bottom that is increased or enlarged by a transition section 212 that is a mirror image of the transition section 214 for the right-side container 116 . The left-side container 112 can thus be considered a third container. It has a top portion with a width substantially equal to the top portion width of the first container 116 . Similarly the left-side container 112 has a bottom having a width substantially equal to the bottom of the right-side container 116 . The left side container 112 has opposing side walls and front and back walls all four of which are attached to the bottom and which extend upwardly to the top. All three containers 112 , 114 and 116 have input inlets or ports described above and identified by reference numeral 302 , 304 , and 306 the shape and areas of which are substantially identical. As best seen in FIG. 3A , those inlet ports are inclined at an angle relative to horizontal to facilitate refilling, the containers. In a preferred embodiment, the inlet ports 302 , 304 and 306 are inclined at the same angle. However, alternate embodiments include inclining those inlet ports at different angles relative to each other. Configuring, the tanks and input ports 302 , 304 and 306 to have the shape as shown is contrary to common sense and non-obvious for at least two reasons. First, molding or assembling the tanks to have transition sections adds cost. Second, as can be seen in FIGS. 8 and 8 , when the containers 112 , 114 and 116 are removed from the compartment 108 , the left-side container 112 and the right-side container 116 are made somewhat unstable by their enlarged openings. The enlarged input ports 302 and 306 for the left-hand container 112 and the righthand container 116 extend sideways outside or beyond the foot prints 700 and 900 of the bottom of the containers. If the left-hand container 112 or the right-hand container 116 is refilled outside the compartment 108 , pouring a liquid into one of the input ports 302 and 306 can create a downward force on transition sections 714 and 914 that creates a torque around the corresponding inside edges 709 and 909 of the bottoms of the containers, which will tend to tip the containers over thus rendering them somewhat difficult to use. When the containers are inside the compartment 108 however, they are held together as an assembly, which prevents either one of them from tipping over during refilling. Those of ordinary skill in the art will recognize that the transition sections 414 A and 414 B on the middle container 114 opened downwardly, which is to say the portions of the transition sections closest to the top 408 are closer to each other than the portions of the transition sections that are attached to or connected to the side walls 406 and 407 . The transition section 714 for the right-side container 116 and the mirror image transition section 914 for the left-side container 112 open upwardly, which is to say the top section of the right-side tank 708 is wider than the bottom section. In addition, the top section of the left-side tank 908 is also wider than the bottom section. Those of ordinary skill in the art will also recognize from FIG. 1 , FIG. 2 , FIG. 3A , and FIG. 3B that the transition section 714 and its adjacent transition section 414 A are complements of each other. The transition section 714 on the right-side container 116 transitions the left-side side wall 707 outwardly, whereas the right-hand transition section 414 A of the middle container 114 transitions the side wall 406 inwardly. Similarly, the transition section 914 on the left-side container 112 transitions the right-side wall, outwardly, whereas the left-hand transition section 414 B of the middle container 114 transitions the side wall 407 inwardly. In one embodiment, the covers 308 , 310 and 312 are pivotally attached to the top covers. However, in an alternate embodiment the covers 308 , 310 and 312 can be pivotally attached to the side walls of the containers. The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the appurtenant claims.

A liquid dispenser has containers, sized, shaped and arranged to enclose different volumes but each of the containers has a top with a refill opening that is substantially the same as the top and openings of the other containers. The containers are provided with curving transition sections that taper the sides of the container to increase or decrease the width of the container to provide a smaller or large top sizes as needed.

BACKGROUND OF THE INVENTION Growth hormone, which is secreted from the pituitary, stimulates growth of all tissues of the body that are capable of growing. In addition, growth hormone is known to have the following basic effects on the metabolic processes of the body: (1) Increased rate of protein synthesis in all cells of the body; (2) Decreased rate of carbohydrate utilization in cells of the body; (3) Increased mobilization of free fatty acids and use of fatty acids for energy. A deficiency in growth hormone secretion can result in various medical disorders, such as dwarfism. Various ways are known to release growth hormone. For example, chemicals such as arginine, L-3,4-dihydroxyphenylalanine (L-DOPA), glucagon, vasopressin, and insulin induced hypoglycemia, as well as activities such as sleep and exercise, indirectly cause growth hormone to be released from the pituitary by acting in some fashion on the hypothalamus perhaps either to decrease somatostatin secretion or to increase the secretion of the known secretagogue growth hormone releasing factor (GRF) or an unknown endogenous growth hormone-releasing hormone or all of these. In cases where increased levels of growth hormone were desired, the problem was generally solved by providing exogenous growth hormone or by administering GRF or a peptidal compound which stimulated growth hormone production and/or release. In either case the peptidyl nature of the compound necessitated that it be administered by injection. Initially the source of growth hormone was the extraction of the pituitary glands of cadavers. This resulted in a very expensive product and carded with it the risk that a disease associated with the source of the pituitary gland could be transmitted to the recipient of the growth hormone. Recombinant growth hormone has become available which, while no longer carrying any risk of disease transmission, is still a very expensive product which must be given by injection or by a nasal spray. Other compounds have been developed which stimulate the release of endogenous growth hormone such as analogous peptidyl compounds related to GRF or the peptides of U.S. Pat. No. 4,411,890. These peptides, while considerably smaller than growth hormones are still susceptible to various proteases. As with most peptides, their potential for oral bioavailability is low. Non peptidal growth hormone secretagogues with a benzolactam structure are disclosed in e.g., U.S. Pat. Nos. 5,206,235, 5,283,241, 5,284,841, 5,310,737 and 5,317,017. Other growth hormone secretagogues are disclosed in PCT Patent Publications WO 94/13696 and WO 94/19367. The instant compounds are low molecular weight peptide analogs for promoting the release of growth hormone which have good stability in a variety of physiological environments and which may be administered parenterally, nasally or by the oral route. SUMMARY OF THE INVENTION The instant invention is directed to certain 3-substituted piperidine compounds which have the ability to stimulate the release of natural or endogenous growth hormone. The compounds thus have the ability to be used to treat conditions which require the stimulation of growth hormone production or secretion such as in humans with a deficiency of natural growth hormone or in animals used for food or wool production where the stimulation of growth hormone will result in a larger, more productive animal. Thus, it is an object of the instant invention to describe the 3-substituted piperidine compounds. It is a further object of this invention to describe procedures for the preparation of such compounds. A still further object is to describe the use of such compounds to increase the secretion of growth hormone in humans and animals. A still further object of this invention is to describe compositions containing the 3-substituted pipeddine compounds for the use of treating humans and animals so as to increase the level of growth hormone secretions. Further objects will become apparent from a reading of the following description. DESCRIPTION OF THE INVENTION The novel 3-substituted piperidines of the instant invention are described by structural Formula I: ##STR2## wherein: R 1 is selected from the group consisting of: C 1 -C 10 alkyl, aryl, aryl(C 1 -C 6 alkyl), (C 3 -C 7 cycloalkyl)(C 1 -C 6 alkyl)-, (C 1 -C 5 alkyl)-K-(C 1 -C 5 alkyl)-, aryl(C 0 -C 5 alkyl)-K-(C 1 -C 5 alkyl)-, and (C 3 -C 7 cycloalkyl)(C 0 -C 5 alkyl)-K-(C 1 -C 5 alkyl)-, where K is --O--, --S(O) m --, --N(R 2 )C(O)--, --C(O)N(R 2 )--, --OC(O)--, --C(O)O--, --CR 2 ═CR 2 --, or --C.tbd.C--, where aryl is selected from: phenyl, naphthyl, indolyl, azaindole, pyridyl, benzothienyl, benzofuranyl, thiazolyl, and benzimidazolyl, and R 2 and alkyl may be further substituted by 1 to 9 halogen, S(O) m R 2a , 1 to 3 of OR 2a or C(O)OR 2a , and aryl may be further substituted by 1 to 3 of C 1 -C 6 alkyl, 1 to 3 of halogen, 1 to 2 of --OR 2 , methylenedioxy, --S(O) m R 2 , 1 to 2 of --CF 3 , --OCF 3 , nitro, --N(R 2 )C(O)(R 2 ), --C(O)OR 2 , --C(O)N(R 2 )(R 2 ), --1H-tetrazol-5-yl, --SO 2 N(R 2 )(R 2 ), --N(R 2 )SO 2 phenyl, or --N(R 2 )SO 2 R 2 ; R 1a is selected from hydrogen and C 1 -C 6 alkyl; R 2 is selected from: hydrogen, C 1 ∝C 6 alkyl, and C 3 -C 7 cycloalkyl, and where two C 1 -C 6 alkyl groups are present on one atom, they may be optionally joined to form a C 3 -C 8 cyclic ring, optionally including oxygen, sulfur or NR 3a , where R 3a is hydrogen, or C 1 -C 6 alkyl, optionally substituted by hydroxyl; R 2a is selected from hydrogen and C 1 -C 6 alkyl; R 4 and R 5 are independently hydrogen, C 1 -C 6 alkyl, or substituted C 1 -C 6 alkyl where the substituents are selected from: 1 to 5 halo, 1 to 3 hydroxy, 1 to 3 C 1 -C 10 alkanoyloxy, 1 to 3 C 1 -C 6 alkoxy, phenyl, phenyloxy, 2-furyl, C 1 -C 6 alkoxycarbonyl, S(O) m (C 1 -C 6 alkyl), or R 4 and R 5 may be taken together to form --(CH 2 ) d --L a (CH 2 ) e -- where L a is --C(R 2 ) 2 --, --O--, --S(O) m -- or --N(R 2 )--, d and e are independently 1 to 3 and R 2 is as defined above; X is selected from the group consisting of: --(CH 2 ) q N(R 8 )C(O)R 2 , --(CH 2 ) q N(R 8 )C(O)R 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 2 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 2 )SO 2 R 9 , --(CH 2 ) q N(R 8 )SO 2 R 8 , --(CH 2 ) q N(R 8 )SO 2 R 2 , --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 2 ), --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 2 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 8 ), --(CH 2 ) q SO 2 N(R 2 )(R 2 ), --(CH 2 ) q SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 2 )(R 8 ), and --(CH 2 ) q R 10 , where the R 2 and (CH 2 ) q groups may be optionally substituted by 1 to 2 C 1 -C 4 alkyl, hydroxyl, C 1 -C 4 lower alkoxy, carboxyl, CONH 2 , S(O) m CH 3 , carboxylate C 1 -C 4 alkyl esters, or 1H-tetrazol-5-yl; Y is selected from the group consisting of: hydrogen, C 1 -C 10 alkyl, --(CH 2 ) t aryl, --(CH 2 ) q (C 3 -C 7 cycloalkyl), --(CH 2 ) q --K--(C 1 -C 6 alkyl), --(CH 2 ) q --K--(CH 2 ) t aryl, --(CH 2 ) q --K--(CH 2 ) t (C 3 -C 7 cycloalkyl containing O--, --NR 2 --, or --S--), and --(CH 2 ) q --K--(CH 2 ) t (C 3 -C 7 cycloalkyl), where K is as defined above, and where the alkyl, R 2 , (CH 2 ) q and (CH 2 ) t groups may be optionally substituted by C 1 -C 4 alkyl, hydroxyl, C 1 -C 4 lower alkoxy, carboxyl, --CONH 2 or carboxylate C 1 -C 4 alkyl esters, and where aryl is phenyl, naphthyl, pyridyl, 1-H-tetrazol-5-yl, thiazolyl, imidazolyl, indolyl, pyrimidinyl, thiadiazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiopheneyl, quinolinyl, pyrazinyl, or isothiazolyl which is optionally substituted by 1 to 3 halogen, 1 to 3 --OR 2 , --C(O)OR 2 , --C(O)N(R 2 )(R 2 ), nitro, cyano, benzyl, 1 to 3 C 1 -C 4 alkyl, --S(O) m R 2 , or 1H-tetrazol-5-yl; A is: ##STR3## where x and y are independently 0, 1, 2 or 3; Z is --N(R 6a )-- or --O--, where R 6a is hydrogen or C 1 -C 6 alkyl; R 7 and R 7a are independently hydrogen, C 1 -C 6 alkyl, trifluoromethyl, phenyl, or substituted C 1 -C 6 alkyl where the substituents are imidazolyl, naphthyl, phenyl, indolyl, p-hydroxyphenyl, --OR 2 , --S(O) m R 2 , --C(O)OR 2 , C 3 -C 7 cycloalkyl, --N(R 2 )(R 2 ), --C(O)N(R 2 )(R 2 ), or R 7 and R 7a may independently be joined to one or both of R 4 and R 5 groups to form an alkylene bridge between the terminal nitrogen and the alkyl portion of the R 7 or R 7a groups, wherein the bridge contains 1 to 5 carbons atoms, or R 7 and R 7a can be joined to one another to form C 3 -C 7 cycloalkyl; R 8 is --(CH 2 ) p aryl, where aryl is selected from: phenyl, naphthyl, pyridyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, thienyl, pyrazinyl, pyrimidinyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, indolyl, quinolinyl, and isoquinolinyl, and where the aryl is optionally substituted with 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 9 is selected from the group consisting of: isoxazolyl, thiazolyl, isothiazolyl, thienyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, indolyl, quinolinyl, and isoquinolinyl, which are optionally substituted by 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 10 is selected from the group consisting of: 1,2,4-oxadiazolyl, pyrazinyl, triazolyl, and phthalimidoyl, which are optionally substituted with --R 2 , --OR 2 or --N(R 2 )(R 2 ); m is 0, 1, or 2; p is 0, 1, 2, or 3; q is 0, 1, 2, 3, or 4; t is 0, 1, 2, or 3; and pharmaceutically acceptable salts and individual diastereomers thereof. In the above structural formula and throughout the instant specification, the following terms have the indicated meanings: The alkyl groups specified above are intended to include those alkyl groups of the designated length in either a straight or branched configuration and if two carbon atoms or more they may include a double or a triple bond. Exemplary of such alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tertiary butyl, pentyl, isopentyl, hexyl, isohexyl, allyl, propargyl, and the like. The alkoxy groups specified above are intended to include those alkoxy groups of the designated length in either a straight or branched configuration and if two or more carbon atoms in length, they may include a double or a triple bond. Exemplary of such alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentoxy, isopentoxy, hexoxy, isohexoxy allyloxy, propargyloxy, and the like. The term "halogen" is intended to include the halogen atom fluorine, chlorine, bromine and iodine. The term "aryl" within the present invention, unless otherwise specified, is intended to include aromatic rings, such as carbocyclic and heterocyclic aromatic rings selected the group consisting of: phenyl, naphthyl, pyridyl, 1-H-tetrazol-5-yl, thiazolyl, imidazolyl, indolyl, pyrimidinyl, thiadiazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiopheneyl, quinolinyl, pyrrazinyl, or isothiazolyl, which may be optionally substituted by 1 to 3 of C 1 -C 6 alkyl, 1 to 3 of halogen, 1 to 2 of --OR 2 , methylenedioxy, --S(O) m R 2 , 1 to 2 of --CF 3 , --OCF 3 , nitro, --N(R 2 )C(O)(R 2 ), --C(O)OR 2 , --C(O)N(R 2 )(R 2 ), --1H-tetrazol-5-yl, --SO 2 N(R 2 )(R 2 ), --N(R 2 )SO 2 phenyl, or --N(R 2 )SO 2 R 2 , wherein R 2 is as defined herein. Certain of the above defined terms may occur more than once in the above formula and upon such occurrence each term shall be defined independently of the other. Preferred compounds of the instant invention include those of Formula Ia: ##STR4## wherein: R 1 is selected from the group consisting of: C 1 -C 10 alkyl, aryl (C 1 -C 4 alkyl)-, C 3 -C 6 cycloalkyl (C 1 -C 4 alkyl)-, (C 1 -C 4 alkyl)-K-(C 1 -C 2 alkyl)-, aryl (C 0 -C 2 alkyl)-K-(C 1 -C 2 alkyl)-, and (C 3 -C 7 cycloalkyl)(C 0 -C 2 alkyl)-K-(C 1 -C 2 alkyl)-, where K is --O--, --S(O) m --, --OC(O)--, or --C(O)O--, and the alkyl groups may be further substituted by 1 to 7 halogen, --S(O) m R 2 , 1 to 3 --OR 2 or --C(O)OR 2 , and aryl is phenyl, naphthyl, indolyl, pyridyl, benzimidazolyl, azaindolyl, benzothienyl or benzofuranyl which may be further substituted by 1-2 C 1 -C 4 alkyl, 1 to 2 halogen, 1 to 2 --OR 2 , --S(O) m R 2 , or --C(O)OR 2 ; R 2 is hydrogen, C 1 -C 6 alkyl, or C 3 -C 7 cycloalkyl, and where two C 1 -C 6 alkyl groups are present on one atom they may be optionally joined to form a C 4 -C 7 cyclic ring optionally including oxygen, sulfur or NR 3a ; R 4 and R 5 are independently hydrogen, C 1 -C 6 alkyl, or substituted C 1 -C 6 alkyl where the substituents are 1 to 5 halo, 1 to 3 hydroxyl, --S(O) m (C 1 -C 6 alkyl) or phenyl; X is selected from the group consisting of: --(CH 2 ) q N(R 8 )C(O)R 2 , --(CH 2 ) q N(R 8 )C(O)R 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 2 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 2 )SO 2 R 9 , --(CH 2 ) q N(R 8 )SO 2 R 8 , --(CH 2 ) q N(R 8 )SO 2 R 2 , --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 2 ), --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 2 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 8 ), --(CH 2 ) q SO 2 N(R 2 )(R 2 ), --CH 2 ) q SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 2 )(R 8 ), and --(CH 2 ) q R 10 , where the R 2 , and (CH 2 ) q groups are optionally substituted by 1 to 2 C 1 -C 4 alkyl, hydroxyl, C 1 -C 4 lower alkoxy, carboxyl, CONH 2 , S(O) m CH 3 , carboxylate C 1 -C 4 alkyl esters, or 1H-tetrazol-5-yl; Y is selected from the group consisting of: hydrogen, C 1 -C 8 alkyl, (CH 2 ) t aryl, --(CH 2 ) q (C 5 -C 6 cycloalkyl), --(CH 2 ) q --K--(C 1 -C 6 alkyl), --(CH 2 ) q --K--(CH 2 ) t aryl, --(CH 2 ) q --(CH 2 ) t (C 3 -C 7 cycloalkyl containing --O--, --NR 2 --, or --S--), and --(CH 2 ) q --K--(CH 2 ) t (C 5 -C 6 cycloalkyl), where K is --O-- or --S(O) m -- and where the alkyl groups are optionally substituted by hydroxyl, carboxyl, CONH 2 , carboxylate C 1 -C 4 alkyl esters or 1H-tetrazole-5-yl and aryl is phenyl, naphthyl, pyridyl, 1-H-tetrazolyl, thiazolyl, imidazolyl, indolyl, pyrimidinyl, thiadiazolyl, pyrazolyl, oxazolyl, isoxazolyl, or thiopheneyl which is optionally substituted by 1 to 3 halogen, 1 to 3 --OR 2 , --C(O)OR 2 , --C(O)N(R 2 )(R 2 ), cyano, 1 to 2 C 1 -C 4 alkyl, benzyl, --S(O) m R 2 , or 1H-tetrazol-5-yl-; A is: ##STR5## where x and y are independently 0, 1 or 2; Z is --NR 6a -- or --O--, where R 6a is hydrogen or C 1 -C 3 alkyl; R 7 and R 7a are independently hydrogen C 1 -C 6 alkyl, trifluoromethyl, phenyl, substituted C 1 -C 6 alkyl where the substituents are imidazolyl, naphthyl, phenyl, indolyl, p-hydroxyphenyl, OR 2 , S(O) m R 2 , C(O)OR 2 , C 5 -C 7 cycloalkyl, --N(R 2 )(R 2 ), --C(O)N(R 2 )(R 2 ); or R 7 and R 7a can independently be joined to one of R 4 or R 5 to form alkylene bridges between the terminal nitrogen and the alkyl portion of R 7 or R 7a groups to form 5 or 6 membered rings; or R 7 and R 7a can be joined to one another to form a C 3 cycloalkyl; R 8 is --(CH 2 ) p aryl, where aryl is selected from: phenyl, naphthyl, pyridyl, thiazolyl, isothiazolyl, oxaxolyl, isoxazolyl, thienyl, pyrazinyl, pyrimidinyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, indolyl, quinolinyl, and isoquinolinyl, and where aryl may be substituted by 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 9 is selected from the group consisting of: isoxazolyl, thiazolyl, isothiazolyl, thienyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, indolyl, quinolinyl, and isoquinolinyl, which may be substituted by 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 10 is selected from the group consisting of: 1,2,4-oxadiazolyl, pyrazinyl, triazolyl, and phthalimidoyl, which are optionally substituted with --R 2 , --OR 2 or --N(R 2 )(R 2 ); m is 0, 1 or 2; p is 0, 1 or 2; q is 0, 1 or 2; t is 0, 1 or 2; and pharmaceutically acceptable salts and individual diastereomers thereof. More preferred compounds of the instant invention include those of Formula Ib: ##STR6## wherein: R 1 is selected from the group consisting of: C 1 -C 10 alkyl, aryl (C 1 -C 3 alkyl)-, (C 3 -C 7 cycloalkyl)(C 1 -C 3 alkyl)-, and aryl (C 0 -C 1 alkyl)-K-(C 1 -C 2 alkyl)-, where K is O or S(O) m and the aryl is phenyl, pyridyl, naphthyl, indolyl, azaindolyl, benzothienyl, or benzimidazolyl which is optionally substituted by 1-2 C 1 -C 4 alkyl, 1 to 2 halogen, 1 to 2 --OR 2 , --S(O) m R 2 , or C(O)OR 2 ; R 2 is hydrogen, C 1 -C 6 alkyl, or C 3 -C 7 cycloalkyl, and where two C 1 -C 6 alkyl groups are present on one atom they may be optionally joined to form a C 5 -C 7 cyclic ring optionally including oxygen, sulfur or NR 3a ; R 4 and R 5 are independently hydrogen, C 1 -C 4 alkyl, or substituted C 1 -C 3 alkyl where the substituents may be 1 to 2 hydroxyl; X is selected from the group consisting of: --(CH 2 ) q N(R 8 )C(O)R 2 , --(CH 2 ) q N(R 8 )C(O)R 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 2 )SO 2 R 9 , --(CH 2 ) q N(R 8 )SO 2 R 8 , (CH 2 ) q N(R 8 )SO 2 R 2 , --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 2 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 8 ), --(CH 2 ) q SO 2 N(R 2 )(R 2 ), --(CH 2 ) q SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 2 )(R 8 ), and --(CH 2 ) q R 10 , where the R 2 , and (CH 2 ) q groups may be optionally substituted by 1 to 2 C 1 14 C 4 alkyl, hydroxyl, C 1 -C 4 lower alkoxy, carboxyl, --CONH 2 , --S(O) m CH 3 , carboxylate C 1 -C 4 alkyl esters, or 1H-tetrazol-5-yl; Y is selected from the group consisting of: hydrogen, C 1 -C 8 alkyl, (CH 2 ) t aryl, --(CH 2 ) q C 5 -C 7 cycloalkyl, --(CH 2 ) q --K--(C 1 -C 6 alkyl), --(CH 2 ) q --K--(CH 2 ) t aryl, and --(CH 2 ) q --(CH 2 ) t (C 5 -C 6 cycloalkyl), where K is S(O) m and where the alkyl groups may be optionally substituted by hydroxyl, carboxyl, CONH 2 , carboxylate C 1 -C 4 alkyl esters or 1H-tetrazole-5-yl and aryl is phenyl, naphthyl, indolyl, pyridyl, thiazolyl, thiopheneyl, pyrazolyl, oxazolyl, isoxazolyl or imidazolyl which may be optionally substituted by 1 to 2 halogen, 1 to 2 --OR 2 , 1 to 2 --N(R 2 )(R 2 ), --CO(OR 2 ), 1 to 2 C 1 -C 4 alkyl, --S(O) m R 2 , or 1H-tetrazol-5-yl; A is: ##STR7## where x and y are independantly 0 or 1; Z is --N(R 6a )-- or --O--, where R 6a is hydrogen or C 1 -C 3 alkyl; R 7 and R 7a are independently hydrogen, C 1 -C 6 alkyl, phenyl, substituted C 1 -C 6 alkyl wherein the substitutent is imidazolyl, naphthyl, phenyl, indolyl, p-hydroxyphenyl, --OR 2 , --S(O) m R 2 , or R 7 and R 7a can independently be joined to one of R 4 or R 5 to form alkylene bridges between the terminal nitrogen and the alkyl portions of R 7 or R 7a groups to form 5 or 6 membered rings; or R 7 or R 7a can be joined to one another to form a C 3 -C 6 cycloalkyl; R 8 is --(CH 2 ) p aryl, where aryl is selected from: phenyl, naphthyl, pyridyl, thiazolyl, isothiazolyl, oxaxolyl, isoxazolyl, thienyl, pyrazinyl, pyrimidinyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, indolyl, quinolinyl, and isoquinolinyl, and where aryl may be substituted by 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 9 is selected from the group consisting of: isoxazolyl, thiazolyl, isothiazolyl, indolyl, thienyl, benzothienyl, benzofuranyl, benzimidazolyl, imidazolyl, quinolinyl, and isoquinolinyl, which may be substituted by 1 to 2 of halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 , or --C(O)N(R 2 )(R 2 ); R 10 is selected form the group consisting of: 1,2,4-oxadiazolyl, pyrazinyl, and triazolyl which may be substituted by --R 2 , --OR 2 , or --N(R 2 )(R 2 ); m is 0, 1, or 2; p is 0,1, or 2 q is 0, 1,or 2; t is 0, 1, or 2; and pharmaceutically acceptable salts and individual diastereomers thereof. Still more preferred compounds of the instant invention include those of Formula Ic: ##STR8## wherein: R 1 is selected from the group consisting of: ##STR9## or their regioisomers where not specified; R 2 is hydrogen, C 1 -C 6 alkyl, or C 3 -C 7 cycloalkyl and where two C 1 -C 6 alkyl groups are present on one atom they may be optionally joined to form a C 5 -C 7 cyclic ring optionally including oxygen, sulfur or NR 3a ; R 4 and R 5 are independently selected from the group consisting of: ##STR10## X is selected from the group consisting of: --(CH 2 ) q N(R 8 )C(O)R 2 , --(CH 2 ) q N(R 8 )C(O)R 8 , --(CH 2 ) q N(R 8 )C(O)OR 2 , --(CH 2 ) q N(R 2 )C(O)OR 8 , --(CH 2 ) q N(R 8 )C(O)OR 8 , --(CH 2 ) q N(R 2 )SO 2 R 9 , --(CH 2 ) q N (R 8 )SO 2 R 8 , --(CH 2 ) q N(R 8 )SO 2 R 2 , --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 2 ), --(CH 2 ) q N(R 2 )SO 2 N(R 2 )(R 8 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 2 ), --(CH 2 ) q N(R 8 )C(O)N(R 2 )(R 8 ), and --(CH 2 ) q N(R 2 )(R 8 ); Y is selected from the group consisting of: hydrogen, ##STR11## or their regioisomers whereof where not specified; A is: ##STR12## where x and y are independently 0 or 1; Z is --(NR 6a )-- or --O--, where R 6a is hydrogen or C 1 -C 6 alkyl; R 7 and R 7a are independently C 1 -C 6 alkyl and substituted C 1 -C 6 alkyl wherein the substituent is phenyl, naphthyl or indolyl or R 7 and R 7a can independently be joined to one of the R 4 or R 5 to form alkylene bridges between the terminal nitrogen and the alkyl portions of R 7 or R 7a to form 5 or 6 membered rings; R 8 is (CH 2 ) p aryl where aryl is selected from: phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, thiazolyl, indolyl, quinolinyl and isoquinolinyl and where the aryl may be substituted by 1 to 2 halogen, --R 2 , --OR 2 , N(R 2 )(R 2 ), --C(O)OR 2 or --C(O)N(R 2 )(R 2 ); R 9 is selected from the group consisting of: isoxazolyl, thiazolyl, indolyl, quinolinyl and isoquinolinyl, which may be substituted by 1 to 2 halogen, --R 2 , --OR 2 , --N(R 2 )(R 2 ), --C(O)OR 2 or --C(O)N(R 2 )(R 2 ); R 10 is 1,2,4-oxadiazolyl which may be substituted by --R 2 , --OR 2 , or --N(R 2 )(R 2 ); m is 0, 1 or 2; p is 0 or 1; q is 0 or 1; t is 0 or 1; and pharmaceutically acceptable salts and individual diasteromers thereof. The most preferred compounds of the instant invention include those of Formula Id: ##STR13## wherein: R 1 is selected from the group consisting of: ##STR14## X is selected from the group consisting of: ##STR15## Y is selected from the group consisting of: hydrogen, ##STR16## R 11 is selected from the group consisting of: ##STR17## and pharmaceutically acceptable salts and individual diasteromers thereof. Throughout the instant application, the following abbreviations are used with the following meanings: ______________________________________Bu butylBn benzylBOC, Boc t-butyloxycarbonylBOP Benzotriazol-1-yloxy tris/dimethylamino)- phosphonium hexafluorophosphatecalc. calculatedCBZ, Cbz BenzyloxycarbonylDCC DicyclohexylcarbodiimideDMF N,N-dimethylformamideDMAP 4-DimethylaminopyridineEDC 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide hydrochlorideEI-MS Electron ion-mass spectroscopyEt ethyleq. equivalent(s)FAB-MS Fast atom bombardment-mass spectroscopyHOBT, HOBt HydroxybenztriazoleHPLC High pressure liquid chromatographyKHMDS Potassium bis(trimethylsilyl)amideLAH Lithium aluminum hydrideLHMDS Lithium bis(trimethylsilyl)amideMe methylMF Molecular formulaMHz MegahertzMPLC Medium pressure liquid chromatographyNMM N-MethylmorpholineNMR Nuclear Magnetic ResonancePh phenylPr propylprep. preparedTFA Trifluoroacetic acidTHF TetrahydrofuranTLC Thin layer chromatographyTMS Tetramethylsilane______________________________________ The compounds of the instant invention all have at least two asymmetric centers when both X and Y are groups other than hydrogen and are different from each other. Additional asymmetric centers may be present depending upon the nature of the various substituents on the molecule. Each such asymmetric center will independently produce two optical isomers and it is intended that all of the possible optical isomers and diastereomers in mixture and as pure or partially purified compounds are included within the ambit of this invention. In the case of the asymmetric carbon atom represented by an asterisk in Formula I, it has been found that compounds are more active as growth hormone secretagogues and, therefore preferred, in which the nitrogen substituent is above and the hydrogen atom is below the plane of the structure as represented in Formula II. An equivalent representation places R 1 and the N-substitutent in the plane of the structure with the C═O group above. This configuration corresponds to that present in a D-amino acid. In most cases, this is also designated an R-configuration, although this will vary according to the value of R 1 used in making R- or S- stereochemical assignments. In the case of the asymmetric center which bears the X and Y groups, in most cases, both R- and S- configurations are consistent with useful levels of growth hormone secretagogue activity. In addition configurations of many of the most preferred compounds of this invention are indicated. When the carbon atom in Formula I bearing an asterisk is of a defined and usually a D- configuration, two diastereomers result according to the absolute configuration at the carbon atom bearing the X and Y groups. These diastereomers are arbitrarily referred to as diastereomer 1 (d 1 ) and diastereomer 2 (d 2 ) in this invention and, if desired, their independent syntheses or chromatographic separations may be achieved as described herein. Their absolute stereochemistry may be determined by the x-ray crystallography of crystalline products or crystalline intermediates which are derivatized, if necessary, with a reagent containing an asymmetric center of known absolute configuration. ##STR18## The instant compounds are generally isolated in the form of their pharmaceutically acceptable acid addition salts, such as the salts derived from using inorganic and organic acids. Examples of such acids are hydrochloric, nitric, sulfuric, phosphoric, formic, acetic, trifiuoroacetic, propionic, maleic, succinic, malonic, methane sulfonic and the like. In addition, certain compounds containing an acidic function such as a carboxy can be isolated in the form of their inorganic salt in which the counterion can be selected from sodium, potassium, lithium, calcium, magnesium and the like, as well as from organic bases. The preparation of compounds of Formula I of the present invention may be carried out in sequential or convergent synthetic routes. Syntheses detailing the preparation of the compounds of Formula I in a sequential manner are presented in the following reaction schemes. The phrase "standard peptide coupling reaction conditions" is used repeatedly here, and it means coupling a carboxylic acid with an amine using an acid activating agent such as EDC, DCC, and BOP in a inert solvent such as dichloromethane in the presence of a catalyst such as HOBT. The uses of protective groups for amine and carboxylic acid to facilitate the desired reaction and minimize undesired reactions are well documented. Conditions required to remove protecting groups which may be present and can be found in Greene, T, and Wuts, P. G. M., Protective Groups in Organic Synthesis, John Wiley & Sons, Inc., New York, N.Y. 1991. CBZ and BOG were used extensively in the synthesis, and their removal conditions are known to those skilled in the art. For example, removal of CBZ groups can be achieved by a number of methods known in the art; for example, catalytic hydrogenation with hydrogen in the presence of a nobel metal or its oxide such as palladium on activated carbon in a protic solvent such as ethanol. In cases where catalytic hydrogenation is contraindicated by the presence of other potentially reactive functionality, removal of CBZ groups can also be achieved by treatment with a solution of hydrogen bromide in acetic acid, or by treatment with a mixture of TFA and dimethylsulfide. Removal of BOC protecting groups is carried out in a solvent such as methylene chloride or methanol or ethyl acetate, with a strong acid, such as trifluoroacetic acid or hydrochloric acid or hydrogen chloride gas. The protected amino acid derivatives 1 are, in many cases, commercially available, where the protecting group L is, for example, BOC or CBZ groups. Other protected amino acid derivatives 1 can be prepared by literature methods (Williams, R. M. Synthesis of Optically Active α-Amino Acids, Pergamon Press: Oxford, 1989). Many of the piperidines, pyrrolidines, and hexahydro-1H-azepines of Formula 2 are either commercially available or known in the literature and others can be prepared following literature methods described for analogous compounds. Some of these methods are illustrated in the subsequent schemes. The skills required in carrying out the reaction and purification of the resulting reaction products are known to those in the art. Purification procedures includes crystallization, normal phase or reverse phase chromatography. ##STR19## Intermediates of Formula 3 may be synthesized as described in Scheme 1. Coupling of amine of Formula 2, whose preparations are described later if they are not commercially available, to protected amino acids of Formula 1, wherein L is a suitable protecting group, is conveniently carried out under standard peptide coupling conditions. ##STR20## Conversion of 3 to intermediate 4 can be carried out as illustrated in Scheme 2 by removal of the protecting group L (CBZ, BOC, etc.) ##STR21## Intermediates of Formula 5, wherein A is --(CH 2 ) x -- C(R 7 )(R 7a )--(CH 2 ) y -- may be coupled to intermediates of Formula 4 to afford compounds of Formula I under standard peptide coupling reaction conditions. The amino acids 5, as amino acid 1, are either commercially available or can be synthesized by routine methods. Also if R 4 or R 5 is a hydrogen then the protected amino acids 6 are employed in the coupling reaction, wherein L is a protecting group as defined above. The removal of L in 7 to afford I, where R 4 ═H, can be carried out as noted above. ##STR22## Compounds of Formula I wherein R 4 and/or R 5 is a hydrogen may be further elaborated to new Compounds I (with side chains R 4 ═R 2 or CH 2 --CH(OH)--CH 2 X, wherein X═H or OH) which are substituted on the amino group as depicted in Scheme 4. Reductive alkylation of I with an aldehyde is carried out under conditions known in the art; for example, by catalytic hydrogenation with hydrogen in the presence of platinum, palladium, or nickel catalysts or with chemical reducing agents such as sodium cyanoborohydride in a protic solvent such as methanol or ethanol in the present of catalytic amount of acid. Alternatively, a similar transformation can be accomplished via an epoxide opening reaction. ##STR23## Compounds of Formula I, wherein A is Z--(CH 2 ) x -- C(R 7 )(R 7a )--(CH 2 ) y and Z is N--R 6a or O may be prepared as shown in Scheme 5 by reacting 4 with reagents 8, wherein X is a good leaving group such as Cl, Br, I, or imidazole. Alternatively, 4 may be reacted with an isocyanate of Formula 9 in an inert solvent such as 1,2-dichloroethane to provide compounds of Formula I where Z is NH. ##STR24## The compounds of general Formula I of the present invention may also be prepared in a convergent manner as described in reaction Schemes 6, 7 and 8. The carboxylic acid protected amino acid derivatives 10 are, in many cases, commercially available where M═methyl, ethyl, or benzyl esters. Other ester protected amino acids can be prepared by classical methods familiar to those skilled in the art. Some of these methods include the reaction of the amino acid with an alcohol in the presence of an acid such as hydrochloric acid or p-toluenesulfonic acid and azeotropic removal of water. Other reactions includes the reaction of a protected amino acid with a diazoalkane, or with an alcohol and an acid activating agent such as EDC, DCC in the presence of a catalyst such as DMAP and removal of the protecting group L. Intermediates of Formula 11 or 11a, may be prepared as shown in Scheme 6 by coupling of amino acid ester 10 to amino acids of Formula 5 or 6. When a urea or carbamate linkage is present in 11 or 11a, it can be introduced as illustrated in Scheme 5. ##STR25## Conversion of the ester 11 or 11a to intermediate acids 12 or 12a may be achieved by a number of methods known in the art as described in Scheme 7; for example, methyl and ethyl esters can be hydrolyzed with lithium hydroxide in a protic solvent like aqueous methanol. In addition, removal of benzyl group can be accomplished by a number of reductive methods including hydrogenation in the presence of palladium catalyst in a protic solvent such as methanol. An allyl ester can be cleaved with tetrakis-triphenylphosphine palladium catalyst in the presence of 2-ethylhexanoic acid in a variety of solvents including ethyl acetate and dichloromethane (see J. Org. Chem., 42, 587 (1982)). ##STR26## Acid 12 or 12a may then be elaborated to I or to I bearing protecting group L (Compound I) as described in Scheme 8. Coupling of piperidines of Formula 2 to acids of Formula 12 or 12a, is conveniently carried out under the standard peptide coupling reaction conditions. Transformation of 7 to I is achieved by removal of the protecting group L. When R 4 and/or R 5 is H, substituted alkyl groups may be optionally added to the nitrogen atom as described in Scheme 4. ##STR27## 3-Monosubstituted piperidines of formula 13 can be prepared by the reduction of pyridine derivatives or their salts by hydrogenation in a suitable organic solvent such as water, acetic acid, alcohol, e.g. ethanol, or their mixture, in the presence of a noble metal catalyst such as platinum or an oxide thereof on a support such as activated carbon, and conveniently at room temperature and atmospheric pressure or under elevated temperature and pressure. 3-Monosubstituted piperidines can also be prepared by modification of the X or Y moiety of the existing 3-monosubstituted piperidines. ##STR28## Illustrated in Scheme 10 is a general way to prepare disubstituted piperidines. Compounds of Formula 13 wherein X is an electron withdrawing group such as --CN, --CO 2 R 2 , where R 2 is alkyl, aryl, and (C 1 -C 4 alkyl)aryl are known compounds or may be prepared by methods analogous to those used for the preparation of such known compounds. The secondary amine of compounds of Formula 13 may be first protected by a protecting group L such as BOC and CBZ using the conventional techniques. Introduction of the Y substitution can be achieved by first reacting compounds of Formula 14 with a strong base such as lithium bis(trimethylsilyl)amide, lithium diisopropylamide following by addition of alkylating or acylating reagents such as alkyl halides, aryl alkyl halides, acyl halides, and haloformates in a inert solvent such as THF at temperatures from -100° C. to room temperature. Thio derivatives where the sulfur is attached directly to an alkyl or an aryl group can be prepared similarly by reacting with a disulfide. The halides used in these reactions are either commercially available or known compounds in the literature or may be prepared by methods analogous to those used for the preparation of known compounds. The protecting group L in compounds of formula 15 may be removed with conventional chemistry to give compounds of Formula 2. ##STR29## Alternative ways of preparing compounds of Formula 2 include construction of the ring itself (Jacoby, R. L. et al, J. Med. Chem., 17, 453-455, (1974)). Alkylation of the cyanoacetates of general formula 16, which are commercially available or may be prepared from literature procedures, with alkyl dihalides such as 1-bromo-2-chloroethane or 1-bromo-3-chloropropane yields the chloride 17. Reduction of the nitriles 17 by borane or by hydrogenation using Raney Ni as a catalyst gives the corresponding primary amines, which upon refluxing in ethanol give compounds of Formula 2a. ##STR30## Alternatively, the cyanoacetates of general formula 16 may be alkylated with an ethoxycarbonylalkyl bromide or reacted with ethyl acrylate to give compounds of Formula 18. Reduction of the nitriles 18 by borane or by hydrogenation using Raney Ni as a catalyst gives the corresponding primary amines, which upon refluxing in ethanol gives lactam 19. Reduction of the lactam 19 by borane gives compounds of Formula 2a. ##STR31## Alternatively, a malonate of general formula 20 may be alkylated with cyanoalkyl bromide or can be reacted with acrylonitrile to form compounds of formula 21. Reduction of the nitriles 21 by borane or by hydrogenation using Raney Ni as a catalyst gives the corresponding primary amines, which upon refluxing in ethanol gives lactam 22. Reduction of the lactam 22 by borane gives compounds of formula 2a. ##STR32## The X, Y functionalities in compounds of general structure may be further elaborated to groups not accessible by direct alkylation. For example in Compound 15 when X═CO 2 Et the ester (provided that this is the only ester group in the molecule) can be saponified to the carboxylic acid, which can be further derivatized to amides or other esters. The carboxylic acid can be converted into its next higher homologue, or to a derivative of the homologous acid, such as amide or ester by an Arndt-Eistert reaction. Alternatively, the ester can be directly homologated by the protocol using ynolate anions described by C. J. Kowalski and R. E. Reddy in J. Org. Chem., 57, 7194-7208 (1992). The resulting acid and/or ester may be converted to the next higher homologue, and so on and so forth. The protecting group L may be removed through conventional chemistry. ##STR33## The ester in 15a may be reduced to an alcohol 18 in a suitable solvent such as THF or ether with a reducing agent such as DIBAL-H and conveniently carried out at temperatures from -100° C. to 0° C. The alcohol may be convened to Compound 19 in a suitable solvent such as dichloromethane using the corresponding isocyanate or with a reagent such as T-C(O)N(R 2 )(R 8 ) where T is leaving group like p-nitrophenol. The hydroxy group in 18 may also be convened to a good leaving group such as mesylate and displaced by a nucleophile such as cyanide or an azide. Reduction of the azide in compounds of Formula 20 to an amine 21 can be achieved by hydrogenation in the presence of a noble metal such as palladium or its oxide or Raney nickel in a protic solvent such as ethanol. The nitrile can be reduced to afford the homologous amine. The amine of Formula 21 may be further elaborated to amides, ureas sulfonamides as defined by X through conventional chemistry. The protecting group L may be removed through conventional chemistry. ##STR34## In cases where oxygen is directly attached to the ring, a convenient method involves the addition reaction by an activated form of an alkyl, aryl, alkylaryl group, such as lithium reagent, Grignard reagents, and the like with a ketone of general formula 28, which is commercially available. Further derivatization of the resulting hydroxy group by reaction with isocyanates or with T-C(O)N(R 8 )(R 2 ) where T is leaving group like p-nitrophenol or N-hydroxysuccinimide and the like gives compounds as defined by Y or X through conventional chemistry. Removal of the benzyl protective group may be carried out under the usual conditions to give compounds of general formula 2b. Shown in Scheme 16 is a general example of acylations. ##STR35## In cases where a nitrogen-substituted group is directly attached to the ring, a convenient method is to use the Curtius rearrangement on the acid 23 to afford the isocyanate 31. Addition of amines or alcohols give ureas or carbamates respectively which can be deprotected to remove L to give special cases of compounds of formula 2. Conversion of the isocyanate to amine by hydrolysis gives compound 32. Further derivatization of the resulting amine group by acylation, sulfonylation, alkylation, and the like to give compounds as defined by Y or X can be done through conventional chemistry. Removal of the protective group L may be carried out under the usual conditions to give compounds of general formula 2c. Shown in Scheme 17 is a general example of acylations. ##STR36## Compounds of formula 34 may also be prepared from N-protected 3-piperidones by reductive alkylation of an amine using reducing agents such as sodium cyanoborohydride optimally in the presence of a means of promoting Schiff base formation such as with molecular sieves. Furthermore, the N-protected 3-piperidone can be reduced to the alcohol as illustrated in Scheme 18, acylated with a good leaving group like mesylate which in turn is displaced by R 8 NH 2 to afford compound 34. ##STR37## Intermediates of formula 36 may be prepared from mesylate 33 by displacing this group with a sulfide or with potassium thioacetate followed by oxidation to the sulfonyl chloride using Cl 2 . Displacement of the chloride with HN(R 2 )(R 8 ) affords the corresponding sulfonamide 36. If R 2 is hydrogen the sulfonamide may be further alkylated with a strong base such as NaH in DMF followed by an equivalent of an alkyl or arylalkyl halide. Alternatively, the compound 33 may be reacted with sodium sulfite to afford a sulfonic acid that can be reacted with oxalyl chloride or thionyl chloride to give compound 35 which is converted to 36 as outlined in Scheme 19. ##STR38## The introduction of hererocycles in the piperidine 3-position from cyano, iminoether, ester, amide and hydroxyamidine substituents in that position is done by methods known in the art. As illustrated in Scheme 20 a 3-amino-1,2,4-oxadiazol-5-yl is synthesized by reacting an ester with hydroxyguanidine in a protic solvent such as ethanol int he presence of sodium ethoxide at reflux. 5-Alkyl-1,2,4-oxadiazol-5-yls are prepared by acylating a protected piperidine 3-hydroxyamidine with an acid chloride in a solvent like pyridine at elevated temperatures. Compounds of the general formula 2 prepared in this manner are racemic when X and Y are not identical. Resolution of the two enatiomers can be conveniently achieved by classical crystallization methods by using a chiral acid such as L- or D-tartaric acid, (+) or (-)-10-camphorsulfonic acid in a suitable solvent such as acetone, water, alcohol, ether, acetate or their mixture. Alternatively, the racemic amine can be reacted with a chiral auxiliary such as (R) or (S)--O--acetylmandelic acid followed by chromatographic separation of the two diastereomers, and removal of the chiral auxiliary by hydrolysis. Alternatively asymmetric alkylation can also be utilized for the synthesis of optically active intermediate by introducing a removable chiral auxiliary in X or in place of L with subsequent chromatographic separation of diastereomers. In cases where a sulfide is present in the molecule, it may be oxidized to a sulfoxide or to a sulfone with oxidizing agents such as sodium periodate, m-chloroperbenzoic acid or Oxone® in an solvent such as dichloromethane, alcohol or water or their mixtures. The compounds of the present invention may also be prepared from a variety of substituted natural and unnatural amino acids of formulas 46. The preparation of many of these acids is described in U.S. Pat. No. 5,206,237. The preparation of these intermediates in racemic form is accomplished by classical methods familiar to those skilled in the art (Williams, R. M. "Synthesis of Optically Active α-Amino Acids" Pergamon Press: Oxford, 1989; Vol. 7). Several methods exist to resolve (DL)- ##STR39## amino acids. One of the common methods is to resolve amino or carboxyl protected intermediates by crystallization of salts derived from optically active acids or amines. Alternatively, the amino group of carboxyl protected intermediates may be coupled to optically active acids by using chemistry described earlier. Separation of the individual diastereomers either by chromatographic techniques or by crystallization followed by hydrolysis of the chiral amide furnishes resolved amino acids. Similarly, amino protected intermediates may be converted to a mixture of chiral diastereomeric esters and amides. Separation of the mixture using methods described above and hydrolysis of the individual diastereomers provides (D) and (L) amino acids. Finally, an enzymatic method to resolve N-acetyl derivatives of (DL)-amino acids has been reported by Whitesides and coworkers in J. Am. Chem. Soc. 1989, 111, 6354-6364. When it is desirable to synthesize these intermediates in optically pure form, established methods include: (1) asymmetric electrophilic amination of chiral enolates (J. Am. Chem. Soc. 1986, 108, 6394-6395, 6395-6397, and 6397-6399), (2) asymmetric nucleophilic amination of optically active carbonyl derivatives, (J. Am. Chem. Soc. 1992, 114, 1906; Tetrahedron Lett. 1987, 28, 32), (3) diastereoselective alkylation of chiral glycine enolate synthons (J. Am. Chem. Soc. 1991, 113, 9276; J. Org. Chem. 1989, 54, 3916), (4) diastereoselective nucleophilic addition to a chiral electrophilic glycinate synthon (J. Am. Chem. Soc. 1986, 108, 1103), (5) asymmetric hydrogenation of prochiral dehydroamino acid derivatives ("Asymmetric Synthesis, Chiral Catalysis; Morrison, J. D., Ed; Academic Press: Orlando, F.L., 1985; Vol 5), and (6) enzymatic syntheses (Angew. Chem. Int. Ed. Engl. 1978, 17, 176). ##STR40## For example, alkylation of the enolate of diphenyloxazinone 38a (J. Am. Chem. Soc. 1991, 113, 9276) with cinnamyl bromide in the presence of sodium bis(trimethylsilyl)amide proceeds smoothly to afford which is converted into the desired (D)-2-amino-5-phenylpentanoic acid 40 by removing the N-t-butyloxycarbonyl group with trifluoroacetic acid and hydrogenation over a PdCl 2 catalyst (Scheme 21). ##STR41## Intermediates of formula 42 which are O-benzyl-(D)-serine derivatives 42 are conveniently prepared from suitably substituted benzyl halides and N-protected-(D)-serine 41. The protecting group L is conveniently a BOC or a CBZ group. Benzylation of 41 can be achieved by a number of methods well known in the literature including deprotonation with two equivalents of sodium hydride in an inert solvent such as DMF followed by treatment with one equivalent of a variety of benzyl halides (Synthesis 1989, 36) as shown in Scheme 22. The O-alkyl-(D)-serine derivatives may also be prepared using an alkylation protocol. Other methods that could be utilized to prepare (D)-serine derivatives of formula 42 include the acid catalyzed benzylation of carboxyl protected intermediates derived from 41 with reagents of formula Ar--CH 2 OC(═NH)CCl 3 (O. Yonemitsu et al., Chem. Pharm. Bull. 1988, 36, 4244). Alternatively, alkylation of the chiral gylcine enolates (J. Am. Chem. Soc. 1991, 113, 9276; J. Org. Chem. 1989, 54, 3916) with ArCH 2 OCH 2 X where X is a leaving group affords 43. In addition D,L-O-aryl(alkyl)serines may be prepared and resolved by methods described above. It is noted that in some cases the order of carrying out the foregoing reaction schemes may be varied to facilitate the reaction or to avoid unwanted reaction products. The utility of the compounds of the present invention as growth hormone secretagogues may be demonstrated by methodology known in the art, such as an assay described by Smith, et al., Science, 260, 1640-1643 (1993) (see text of FIG. 2 therein). In particular, the intrinsic growth horomone secretagogue activities of the compounds of the present invention may be demonstrated in this assay. The compounds of the following examples have activity in the aforementioned assay in the range of 0.1 nm to 5 μm. The growth hormone releasing compounds of Formula I are useful in vitro as unique tools for understanding how growth hormone secretion is regulated at the pituitary level. This includes use in the evaluation of many factors thought or known to influence growth hormone secretion such as age, sex, nutritional factors, glucose, amino acids, fatty acids, as well as fasting and non-fasting states. In addition, the compounds of this invention can be used in the evaluation of how other hormones modify growth hormone releasing activity. For example, it has already been established that somatostatin inhibits growth hormone release and that the growth hormone releasing factor (GRF) stimulates its release. Other hormones that are important and in need of study as to their effect on growth hormone release include the gonadal hormones, e.g., testosterone, estradiol, and progesterone; the adrenal hormones, e.g., cortisol and other corticoids, epinephrine and norepinephrine; the pancreatic and gastrointestinal hormones, e.g., insulin, glucagon, gastrin, secretin; the vasoactive peptides, e.g., bombesin, the neurokinins; and the thyroid hormones, e.g., thyroxine and triiodothyronine. The compounds of Formula I can also be employed to investigate the possible negative or positive feedback effects of some of the pituitary hormones, e.g., growth hormone and endorphin peptides, on the pituitary to modify growth hormone release. Of particular scientific importance is the use of these compounds to elucidate the subcellular mechanisms mediating the release of growth hormone. The compounds of Formula I can be administered to animals, including man, to release growth hormone in vivo. For example, the compounds can be administered to commercially important animals such as swine, cattle, sheep and the like to accelerate and increase their rate and extent of growth, to improve feed efficiency and to increase milk production in such animals. In addition, these compounds can be administered to humans in vivo as a diagnostic tool to directly determine whether the pituitary is capable of releasing growth hormone. For example, the compounds of Formula I can be administered in vivo to children. Serum samples taken before and after such administration can be assayed for growth hormone. Comparison of the amounts of growth hormone in each of these samples would be a means for directly determining the ability of the patient's pituitary to release growth hormone. Accordingly, the present invention includes within its scope pharmaceutical compositions comprising, as an active ingredient, at least one of the compounds of Formula I in association with a pharmaceutical carrier or diluent. Optionally, the active ingredient of the pharmaceutical compositions can comprise an anabolic agent in addition to at least one of the compounds of Formula I or another composition which exhibits a different activity, e.g., an antibiotic growth permittant or an agent to treat osteoporosis or in combination with a corticosteroid to minimize the catabolic side effects or with other pharmaceutically active materials wherein the combination enhances efficacy and minimizes side effects. Growth promoting and anabolic agents include, but are not limited to, TRH, diethylstilbesterol, estrogens, β-agonists, theophylline, anabolic steroids, enkephalins, E series prostaglandins, retinoic acid, compounds disclosed in U.S. Pat. No. 3,239,345, e.g., zeranol, and compounds disclosed in U.S. Pat. No. 4,036,979, e.g., sulbenox. or peptides disclosed in U.S. Pat. No. 4,411,890. A still further use of the growth hormone secretagogues of this invention is in combination with other growth hormone secretagogues such as the growth hormone releasing peptides GHRP-6, GHRP-1 as described in U.S. Pat. Nos. 4,411,890 and publications WO 89/07110, WO 89/07111 and B-HT920 as well as hexarelin and GHRP-2 as described in WO 93/04081 or growth hormone releasing hormone (GHRH, also designated GRF) and its analogs or growth hormone and its analogs or somatomedins including IGF-1 and IGF-2 or α-adrenergic agonists such as clonidine or serotonin 5HTID agonists such as sumitriptan or agents which inhibit somatostatin or its release such as physostigmine and pyridostigmine. For example, a compound of the present invention may be used in combination with IGF-1 for the treatment or prevention of obesity. In addition, a compound of this invention may be employed in conjunction with retinoic acid to improve the condition of musculature and skin that results from intrinsic aging. As is well known to those skilled in the art, the known and potential uses of growth hormone are varied and multitudinous. Thus, the administration of the compounds of this invention for purposes of stimulating the release of endogenous growth hormone can have the same effects or uses as growth hormone itself. These varied uses may be summarized as follows: treating growth hormone deficient adults; prevention of catabolic side effects of glucocorticoids; treatment of osteoporosis; stimulation of the immune system, acceleration of wound healing; accelerating bone fracture repair; treatment of growth retardation; treating acute or chronic renal failure or insufficiency; treatment of physiological short stature, including growth hormone deficient children; treating short stature associated with chronic illness; treating obesity and growth retardation associated with obesity; treating growth retardation associated with Prader-Willi syndrome and Turner's syndrome; accelerating the recovery and reducing hospitalization of burn patients or following major surgery such as gastrointestinal surgery; treatment of intrauterine growth retardation, and skeletal dysplasia, treatment of peripheral neuropathies; replacement of growth hormone in stressed patients; treatment of osteochondrody-splasias, Noonans syndrome, schizophrenia, depression, Alzheimer's disease, delayed wound healing, and psychosocial deprivation; treatment of pulmonary dysfunction and ventilator dependency; attenuation of protein catabolic response after a major operation; treating malabsorption syndromes; reducing cachexia and protein loss due to chronic illness such as cancer or AIDS; accelerating weight gain and protein accretion in patients on TPN (total parenteral nutrition); treatment of hyperinsulinemia including nesidioblastosis; adjuvant treatment for ovulation induction and to prevent and treat gastric and duodenal ulcers; stimulation of thymic development and preventtion of the age-related decline of thymic function; adjunctive therapy for patients on chronic hemodialysis; treatment of immunosuppressed patients and to enhance antibody response following vaccination; increasing the total lymphocyte count of a human, in particular, increasing the T 4 /T 8 -cell ratio in a human with a depressed T 4 /T 8 -cell ratio resulting, for example, from infection, such as bacterial or viral infection, especially infection with the human immunodeficiency virus; treatment of syndromes manifested by non-restorative sleep and musculoskeletal pain, including fibromyalgia syndrome or chronic fatigue syndrome; improvement in muscle strength, mobility, maintenance of skin thickness, metabolic homeostasis, renal hemeostasis in the frail elderly; stimulation of osteoblasts, bone remodelling, and cartilage growth; stimulation of the immune system in companion animals and treatment of disorders of aging in companion animals; growth promotant in livestock; and stimulation of wool growth in sheep. Further, the instant compounds are useful for increasing feed efficiency, promoting growth, increasing milk production and improving the carcass quality of livestock. Likewise, the instant compounds are useful in a method of treatment of diseases or conditions which are benefited by the anabolic effects of enhanced growth hormone levels that comprises the administration of an instant compound. In particular, the instant compounds are useful in the prevention or treatment of a condition selected from the group consisting of: osteoporosis; catabolic illness; immune deficiency, including that in individuals with a depressed T 4 /T 8 cell ratio; hip fracture; musculoskeletal impairment in the elderly; growth hormone deficiency in adults or in children; obesity; cachexia and protein loss due to chronic illness such as AIDS or cancer; and treating patients recovering from major surgery, wounds or bums, in a patient in need thereof. In addition, the instant compounds may be useful in the treatment of illnesses induced or facilitated by corticotropin releasing factor or stress- and anxiety-related disorders, including stress-induced depression and headache, abdominal bowel syndrome, immune suppression, HIV infections, Alzheimer's disease, gastrointestinal disease, anorexia nervosa, hemorrhagic stress, drug and alcohol withdrawal symptoms, drug addiction, and fertility problems. It will be known to those skilled in the art that there are numerous compounds now being used in an effort to treat the diseases or therapeutic indications enumerated above. Combinations of these therapeutic agents some of which have also been mentioned above with the growth hormone secretagogues of this invention will bring additional, complementary, and often synergistic properties to enhance the growth promotant, anabolic and desirable properties of these various therapeutic agents. In these combinations, the therapeutic agents and the growth hormone secretagogues of this invention may be independently present in dose ranges from one one-hundredth to one times the dose levels which are effective when these compounds and secretagogues are used singly. Combined therapy to inhibit bone resorption, prevent osteoporosis and enhance the healing of bone fractures can be illustrated by combinations of bisphosphonates and the growth hormone secretagogues of this invention. The use of bisphosphonates for these utilities has been reviewed, for example, by Hamdy, N.A.T., "Role of Bisphosphonates in Metabolic Bone Diseases" Trends in Endocrinol. Metab., 4, 19-25 (1993). Bisphosphonates with these utilities include alendronate, tiludronate, dimethyl-APD, risedronate, etidronate, YM-175, clodronate, pamidronate, and B M-210995. According to their potency, oral daily dosage levels of the bisphosphonate of between 0.1 mg and 5 g and daily dosage levels of the growth hormone secretagogues of this invention of between 0.01 mg/kg to 20 mg/kg of body weight are administered to patients to obtain effective treatment of osteoporosis. In the case of alendronate daily oral dosage levels of 0.1 mg to 50 mg are combined for effective osteoporosis therapy with 0.01 mg/kg to 20 mg/kg of the growth hormone secretagogues of this invention. Osteoporosis and other bone disorders may also be treated with compounds of this invention in combination with calcitonin, estrogens, raloxifene and calcium supplements such as calcium citrate. Anabolic effects especially in the treatment of geriatric male patients are obtained with compounds of this invention in combination with anabolic steroids such as oxymetholone, methyltesterone, fluoxymesterone and stanozolol. The compounds of this invention can be administered by oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous or subcutaneous injection, or implant), nasal, vaginal, rectal, sublingual, or topical routes of administration and can be formulated in dosage forms appropriate for each route of administration. Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert pharmaceutically acceptable carrier such as sucrose, lactose, or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings. Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, the elixirs containing inert diluents commonly used in the art, such as water. Besides such inert diluents, compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavoring, and perfuming agents. Preparations according to this invention for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and com oil, gelatin, and injectable organic esters such as ethyl oleate. Such dosage forms may also contain adjuvants such as preserving, wetting, emulsifying, and dispersing agents. They may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. They can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use. Compositions for rectal or vaginal administration are preferably suppositories which may contain, in addition to the active substance, excipients such as cocoa butter or a suppository wax. Compositions for nasal or sublingual administration are also prepared with standard excipients well known in the art. The dosage of active ingredient in the compositions of this invention may be varied; however, it is necessary that the amount of the active ingredient be such that a suitable dosage form is obtained. The selected dosage depends upon the desired therapeutic effect, on the route of administration, and on the duration of the treatment. Generally, dosage levels of between 0.000 g to 10 mg/kg. of body weight daily are administered to patients and animals, e.g., mammals, to obtain effective release of growth hormone. The following examples are provided for the purpose of further illustration only and are not intended to be limitations on the disclosed invention. ##STR42## Step A: ##STR43## To a solution of the commercially available N-t-BOC-D-tryptophan (25.0 g, 82.2 mmol), benzyl alcohol (10.2 mL, 98.6 mmol), and DMAP (100 mg) in dichloromethane (200 mL) at 0° C., was added EDC (17.4 g, 90.4 mmol) in several portions over a one hour period. The reaction mixture was stirred at room temperature for six hours and was poured into water (200 mL), and the organic layer was separated. The organic solution was washed with a mixture of brine and 3N hydrochloric acid, dried over anhydrous magnesium sulfate, filtered and concentrated to give a thick oil, which solidified upon standing. To a solution of this oil in 30 mL of dichloromethane was added 20 mL of TFA and stirred for 1h. The reaction mixture was concentrated, neutralized carefully with saturated aqueous sodium bicarbonate solution, and extracted with dichloromethane (2×100 mL). The combined organic solution was washed with brine (100 mL), passed through a short column of silica gel eluting with 5-10% methanol in dichloromethane to give 23.2 g of the amine as an oil after evaporation. Step B: ##STR44## To a solution of the above product, HOBT (10.6 g, 78.8 mmol) and N-BOC-α-methyl alanine (19 g, 94.5 mmol) in 200 mL of dichloromethane, was added EDC (19.5 g, 0.102 mol) in several portions at 0° C. After 5 minutes, the clear reaction mixture became milky. After stirring at room temperature overnight, the reaction mixture was poured into 200 mL of water and the organic layer was separated. The organic solution was washed with brine, and with a brine and saturated sodium bicarbonate solution, dried over anhydrous magnesium sulfate, filtered and concentrated to give a thick oil, which was purified by flash chromatography eluting with 10-40% ethyl acetate in hexane to give the desired material (28.7 g). 1 H NMR (CDCl 3 , 200 MHz) δ8.48 (br.s, 1H), 7.54 (br.d, 1H), 7.38-7.23 (m, 3H), 7.19 (br.d, 2H), 7.15-7.00 (m, 1H), 6.90 (d, 1H), 6.86 (d, 1H), 5.06 (br.s, 2H), 4.95 (ddd, 1H), 3.30 (2dd, 2H), 1.40 (s, 15H) Step C: ##STR45## A solution of the material from Step B (28.7 g) in 200 mL of ethanol was stirred at RT under a H 2 balloon for 20 minutes in the presence of 10% palladium on carbon (2 g). The catalyst was filtered off through a pad of celite and washed with ethyl acetate. The filtrate was concentrated to give the acid as a slightly pink foam (23.3 g). 1 H NMR (CD 3 OD, 400 MHz) δ7.56 (d, J=8 Hz, 1H), 7.31 (dd, J=1,8 Hz, 1H), 7.09 (s, 1H), 7.07 (dt, J=1,7 Hz, 1H), 6.98 (dt, J=1,7 Hz, 1H), 4.69 (t, J=6 Hz, 1H), 3.34-3.23 (m, 2H), 1.35 (s, 3H), 1.34 (s, 9H) 1.29 (s, 3H). FAB-MS calc. for C 20 H 27 N 3 O 5 : 389; Found 390 (M+H), 290 (M+H-100 (BOG)) ##STR46## Following the procedures for the preparation of Intermediate using N-t-Boc-O-Benzyl-D-serine in the place of N-t-BOC-D-tryptophan gave Intermediate 2. FAB-MS calc. for C 19 H 28 N 2 O 6 : 380; Found 381 (M+H), 325 (M+H-56 (t-Bu)), 281 (M+H-100 (BOC)). ##STR47## Step A: (DL)-N-Acetyl-2-amino-5-phenylpentanoic acid To a solution of sodium (2.3 g, 0.1 mol) in ethanol (60 mL) under nitrogen at room temperature, was added diethyl acetamidomalonate. The mixture was stirred at room temperature for one hour, and then 1-bromo-3-phenylpropane was added dropwisely. After the addition, the mixture was stirred at room temperature for two hours, then refluxed overnight. It was cooled to room temperature and partitioned between water and ethyl acetate. The organic layer was washed with sodium bicarbonate in water, dried over MgSO4 and evaporated to give an intermediate (32.5 g, 97%). 1 H NMR (CDCl 3 , 400 MHz) 7.26-7.10 (m, 5H); 6.75 (br. s, 1H); 4.19 (q, J=7 Hz, 4H); 2.58 (t, J=7.9 Hz, 2H); 2.39-2.35 (m, 2H); 2.00 (s, 3H); 1.43-1.39 (m, 2H); 1.20 (t, J=7 Hz, 6H). The product above was suspended in 190 mL of 2.5N NaOH in water and refluxed for two hours. The mixture was cooled to 0° C., and it was carefully neutralized with 6N HCl to pH2. The precipitate was collected using a glass sinter funnel and washed with a small amount of cold water and air dried. The solid was then suspended in 300 mL of water and refluxed for four hours. The solution was cooled and acidified to pH1 and the solid was collected by filtration (15.3 g, 67%). 1 H NMR (CD3OD, 400 MHz) 7.26-7.12 (m, 5H); 4.90-4.37 (m, 1H); 2.65-2.60 (m, 2H); 1.97 (s, 3H); 1.87-1.82 (m, 1H); 1.73-1.65 (m, 3H). Step B: (D)-N-Acetyl-2-amino-5-phenylpentanoic acid The racemic intermediate from the previous step (10 g, 42.5 mmol) and CoCl3-6H 2 O were dissolved in 21 ml of 2N KOH and 200 mL of water at 40° C., and the pH of the solution was adjusted to 8 by the addition of the several drops of 2N KOH. Then acylase I (Aspergillus sp, 0.5 μ/rag, from Sigma; 0.9 g) was added with vigorous stirring. The reaction mixture was stirred for one day at 40° C. and the pH was kept at 8 by the addition of a few drops of KOH. The solid which formed was filtered off. The tiltrate was acidified by 3N HCl to pH2, and was extracted with ethyl acetate (200 mL×4). The organic extracts were combined and evaporated to give a white solid (4.64 g, 46%) 1 H NMR (CD3OD, 400 MHz) 7.26-7.12 (m, 5H); 4.90-4.37 (m, 1H); 2.65-2.60 (m, 2H); 1.97 (s, 3H); 1.87-1.82 (m, 1H); 1.73-1.65 (m, 3H). Step C: (D)-N-t-Boc-2-amino-5-phenylpentanoic acid The intermediate from step B (4.2 g, 17.8 mmol) was suspended in 2N HCl (100 mL) and refluxed for two hours. The reaction mixture was evaporated in vacuo to remove water and hydrochloric acid to yield a white solid. To a solution of this solid in 50 mL of water, was added 3N NaOH until the pH 11, then di-t-butyl dicarbonate (4.66 g, 21.4 mmol) was added with vigorous stirring. After four hours, the reaction mixture was acidified to pH2 with 3N HCl and it was extracted with ethyl acetate (100 mL×3 ). The organic extracts were combined and evaporated to give a white solid (6.56 g, crude) which was used without purification. 1 H NMR (CD3OD, 400 MHz) 7.26-7.12 (m, 5H); 4.11-4.08 (m, 1H); 2.65-2.60 (m, 2H); 1.83-1.62 (m, 4H); 1.43 (s, 9H). Step D: ##STR48## Following the procedures for the preparation of Intermediate 1 using (D)-N-t-Boc-2-amino-5-phenylpentanoic acid in the place of N-t-BOC-D-tryptophan gave Intermediate 3. 1 H NMR (CDCl 3 , 400 MHz) 7.24-7.20 (m, 2H), 7.15-7.04 (m, 3H), 4.60-4.55 (m, 1H), 2.62-2.55 (m, 2H), 2.00-1.86 (m, 1H), 1.78-1.60 (m, 3H), 1.50 (s, 6H), 1.30 (s, 9H). EXAMPLE 1 N'-Benzyl-N'-phenylsulfonyl-3-amino-piperidine hydrochloride Step A: N-(tert-Butoxycarbonyl)-3-piperidinol To a solution of 3-piperidinol (2.51 g; 18.2 mmol) in 10% Na 2 CO 3 (66 ml) and dioxane (27 ml), cooled to 0° C., is added di-tert -butyl dicarbonate (3.57 g; 17.1 mmol) portionwise. After the addition, the reaction mixture was stirred for an additional two hours at room temperature. The aqueous phase was extracted with EtOAc (5×100 ml). The combined organic extracts were then washed with 10% aqueous citric acid, water, saturated aqueous NaCl, dried (MgSO 4 ), filtered, and evaporated. The compound was dried in vacuo to afford 2.93 g of the title compound which was used in the next step without further purification. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.03-1.53 (m, 11H), 1.54-1.79 (m, 1H), 1.80-1.95 (m, 1H), 2.53-3.09 (m, 2H), 3.4-3.53 (m, 1H), 3.55-3.72 (m, 1H), 3.73-3.90 (dd, 1H). Step B: N:(tert-Butoxycarbonyl)piperidin-3-one To a cooled (-65° C.) solution of DMSO (1.42 ml; 20 mmol) in CH 2 Cl 2 (30 ml) was added oxalyl chloride (0.87 ml; 10 mmol). The resulting suspension was stirred for an additional 15 minutes at -65° C., whereupon the product of Step A (2.17 g; 10 mmol) dissolved in 5 ml of CH 2 Cl 2 was added portionwise and the reaction was stirred for an additional 15 minutes at that temperature. Triethylamine (5.56 ml; 40 mmol) was then added dropwise, and the solution was allowed to warm to room temperature, whereupon the reaction was stirred for an additional 1.5 hours. The reaction was quenched with H 2 O and extracted several times with EtOAc. The combined organic phase was washed with 10% aqueous citric acid, H 2 O, saturated aqueous NaCl, dried (MgSO 4 ), filtered and evaporated. The residue was purified on a silica gel flash chromatography column eluted with 25% EtOAc-hexanes. The fractions containing pure material were combined and concentrated in vacuo to afford 1.87 g of the title compound as a yellow oil. 1 H-NMR (400 MHz, CD 3 OD, ppm): δ1.38-1.48 (s, 9H), 1.52-1.72 (m, 1H), 1.90-2.00 (p, 1H), 2.40-2.50 (t, 1H), 2.95-3.15 (m, 1H), 3.45-3.80 (m, 3H), 3.90-4.00 (s, 1H). Step C. N-(tert-Butoxycarbonyl)-N-benzyl-3-aminopiperidine To a solution of the title compound in Step B (500 mg; 2.5 mmol) in MeOH (7 ml) consisting of HOAc (425 μl), benzylamine (273 μl; 2.5 mmol), and 4 A° powdered sieves, was added NaCNBH 3 (319 mg; 5.0 mmol) at room temperature. The reaction was stirred at room temperature for two hours, whereupon it was quenched with H 2 O and extracted with EtOAc (2×200 ml). The combined organic extracts were washed with 1N aqueous NaOH, H 2 O, saturated aqueous NaCl, dried (MgSO 4 ), filtered and evaporated. The residue was purified by silica gel radial chromatography eluted with CH 2 Cl 2 followed by CH 2 Cl 2 -MeOH (20:1). The fractions containing pure material were combined and concentrated in vacuo to afford 601 mg of the title compound as a yellow oil. The material was used as is in the next step. Step D: N-(tert-Butoxycarbonyl)-N-benzyl-N'-phenylsulfonyl-3-aminopiperidine To a solution of the title compound in Step C (601 mg; 2.07 mmol) in CH 2 Cl 2 (2 ml) and N-methylmorpholine (227 μl; 2.07 mmol), cooled to 0° C., was added phenylsulphonylchloride (396 μl; 3.1 mmol), and the reaction was allowed to stir at room temperature for three hours. The reaction was quenched with H 2 O and extracted with EtOAc. The organic phase was washed with H 2 O, saturated aqueous NaCl, dried (MgSO 4 ), filtered and evaporated. The residue was purified by silica gel radial chromatography eluted with CH 2 Cl 2 . The fractions containing pure material were combined and concentrated in vacuo to afford 468 mg of the title compound as a white foam. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.20-1.40 (s, 9H), 1.45-1.65 (m, 4H), 2.20-2.60 (m, 2H), 3.45-3.70 (bs, 1H), 3.75-3.93 (dd, 2H), 4.25-4.45 (d, 1H), 4.50-4.4.65 (d, 1H), 7.10-7.43 (m, 5H), 7.45-7.70(m, 3H), 7.75-7.90 (dd, 2H). CI-MS m/e=431 (M+1). Step E: N'-benzyl-N'-phenylsulfonyl-3-amino-piperidine hydrochloride A solution of the title compound in Step D (264 mg; 0.613 mmol) in cold saturated solution of HCl in THF (2 ml) was stirred at room temperarure for one hour. The solvent was removed in vacuo and the residue was triturated with EtOAc, filtered under N 2 , washed with EtOAc, ether, and let dry under vacuo and N 2 . The solid was dried in vacuo overnight to yield 206 mg of the title compound as a white solid. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.40-1.95 (m, 4H), 2.46-2.75 (t, 2H), 2.94-3.20 (m, 2H), 3.82-4.10 (m, 1H), 4.18-4.44 (d, 1H), 4.49-4.74 (d, 1H), 7.05-7.45 (m, 5H), 7.50-7.75 (m, 3H), 7.80-8.00 (dd, 2H). CI-MS m/e=331 (M+1). EXAMPLE 2 N-Phenyl-N'-phenylsulfonyl-3-amino-piperidine hydrochloride Step A: N-(tert-Butoxycarbonyl)-N-phenyl-3-aminopiperidine The titled compound was prepared from the product obtained in Step B of Example 1, using a procedure similar to that described in Step C of Example 1 replacing benzylamine with aniline as the amine source. Purification yields 522 mg (60%) of the title compound as a yellow solid, which was used as is in the next step. Step B: N-(tert-Butoxycarbonyl)-N-phenyl-N'-phenylsulfonyl-3-aminopiperidine The titled product was prepared from the product obtained in Step A using the procedure in Step D of Example 1 to yield 530 mg (67%) of the titled compound as a white solid. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.03-1.32 (m, 1H), 1.35-1.55 (s, 9H), 1.55-1.70 (m, 2H), 2.15-2.60 (m, 2H), 3.70-3.94 (d, 1H), 3.97-4.16 (m, 1H), 4.17-4.30 (d, 1H), 6.85-7.03 (dd, 2H), 7.20-7.43 (m, 3H), 7.45-7.80 (m, 5H). CI-MS m/e=418 (M+1). Step C: N-phenyl-N'-phenylsulfonyl-3-aminopiperidine hydrochloride The titled product was prepared from the product obtained in Step B using the procedure described in Step E of Example 1 to yield 403 mg of the titled compound as a white solid. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.15-1.40 (m, 1H), 1.70-2.05 (m, 3H), 2.55-2.65 (dd, 1H), 2.66-2.80 (t, 1H), 3.15-3.25 (dd, 1H), 3.45-3.60 (dd, 1H), 4.40-4.60 (m, 1H), 6.92-7.11 (dd, 2H), 7.18-7.45 (m, 3H), 7.47-7.80 (m, 5H). CI-MS m/e=318 (M+1). EXAMPLE 3 ##STR49## The following general synthesis was applied for the preparation of all compounds listed in Table I below: Step A: A solution of the Intermediate 1 (or 3) (0.268 mmol) in CH 2 Cl 2 (1 ml) was cooled to 0° C., to which was added the titled compound from Step E of Example 1 (or Step C of Example 2) (0.314 mmol). To the solution was then added HOBT (0.392 mmol), followed by NMM (0.527 mmol), and EDC (0.344 mmol). The reaction was stirred for one hour at room temperature, and then partitioned between H 2 O and EtOAc. The organic phase was washed with saturated aqueous NaHCO 3 , H 2 O, 10% aqueous citric acid, H 2 O, saturated aqueous NaCl, dried (MgSO 4 ), filtered and evaporated. The residue was purified by silica gel radial chromatography eluted with 50% EtOAc-hexanes. The fractions containing pure compound were combined and concentrated in vacuo to afford the desired product as either a mixture of diastereoismers (1+2), or individual isomers (1 or 2). Step B: HCl(g) was bubbled into a solution of the product from Step A (0.108 mmol) in EtOAc (2 ml), and the reaction was stirrred at room temperature for one hour. The solvent was removed in vacuo, and the residue was triturated with ether, filtered under N 2 , and dried in vacuo to yield the desired product as a white solid. TABLE I______________________________________ CI-MS Log PIsomer R.sup.a R.sup.b (M + 1) (min) Cpd #______________________________________Recemic 3-Indolyl --CH.sub.2 Ph 602 3.6 3aIsomer 1 3-Indolyl Ph 588 3.2 3bIsomer 2 3-Indolyl Ph 588 3.0 3cIsomer 1 Ph(CH.sub.2).sub.3 -- --CH.sub.2 Ph 591 4.4 3dIsomer 2 Ph(CH.sub.2).sub.3 -- --CH.sub.2 Ph 591 4.4 3eRecemic Ph(CH.sub.2).sub.3 -- Ph 577 4.2 3fIsomer 2 Ph(CH.sub.2).sub.3 -- Ph 577 4.0 3g______________________________________ TABLE II______________________________________Cpd # .sup.1 H-NMR δ (400 MHz, CD.sub.3 OD, ppm)______________________________________3a -0.433-(-)0.151(m, 0.22H), 0.795-1.84(m, 11H), 1.89- 2.08(m, 1.2H), 2.09-2.25(m, 0.37H), 2.35-2.57(m, 0.33H), 2.67-2.89(m, 0.26H), 2.94-3.26(m, 2.4H), 3.46-3.78(m, 1.45H), 3.79-3.95(m, 0.39H), 4.00-4.38(m, 2.57H), 4.44- 4.62(m, 0.53H), 4.64-4.83(m, 0.41H), 4.94-5.17(m, 1.3H), 6.75-8.07(m, 15H).3b 0.78-0.98(m, 0.4H), 1.02-1.26(m, 1.3H), 1.30-1.76(m, 8.8H), 1.77-2.01(m, 2.0H), 2.06-2.29(m, 0.45H), 2.76-2.99 (m, 0.41H), 3.00-3.25(m, 1.9H), 3.34-3.81(m, 1.8H)3.97- 4.15(m, 0.7H), 4.19-4.34(m, 0.5H), 4.37-4.51(m, 0.4H), 4.53-4.51(m, 0.6H), 4.98-5.29(m, 1.1H), 6.76-7.91(m, 15H).3c -0.229-0.093(m, 0.11H), 0.854-1.13(m, 1.25H), 1.16-1.95 (m, 10.9H), 1.98-2.19(m, 0.25H), 2.34-2.52(m, 0.19H), 2.98-3.27(m, 2.7H), 3.49-3.69(m, 0.51H), 4.11-4.36(m, 1.47H), 4.53-4.70(m, 0.2H), 4.92-5.19(m, 1.24H), 6.24-6.49 (m, 1.3H), 6.77-6.98(m, 1.9H), 7.00-7.49(m, 6.49H), 7.51- 7.98(m, 5.29H).3d 0.736-1.06(m, 0.15H), 1.11-2.02(m, 16.3H), 2.09-2.41(m, 1.1H), 2.46-2.84(m, 3.62), 2.86-3.03(m, 2.1H), 3.05-3.27 (1.1H), 3.38-3.56(m, 0.49H), 3.60-3.80(m, 1.3H), 3.85-4.07 (m, 0.7H), 4.08-4.19(m, 0.3H), 4.22-4.49(m, 2.1H), 4.50- 4.86(m, 1.6H), 6.98-7.50(m, 9.9H), 7.51-7.72(m, 2.9H), 7.74-8.03(m, 2.22H).3e 0.864-1.07(m, 0.3H), 1.09-2.00(m, 16H), 2.13-2.38(m, 0.9H), 2.46-2.88(m, 3.6H), 3.04-3.26(m, 0.5H), 3.43-3.78 (m, 1.3H), 3.87-4.07(m, 0.8H), 4.09-4.19(m, 0.3H), 4.21- 4.50(m, 2.2H), 4.52-4.78(m, 1.9H), 7.03-7.50(m, 9.9H), 7.51-7.56(m, 3.1H), 7.78-7.93(m, 1.1H), 7.95-8.12(m, 0.9H).3f 1.02-1.49(m, 2H), 1.52-2.13(m, 14H), 2.16-2.43(m, 1H), 2.48-2.93(m, 3.3H), 2.96-3.13(m, 0.3H), 3.15-3.25(m, 0.2H), 3.43-3.83(m, 0.8H), 3.90-4.74(m, 3H), 4.74-4.84(m, 0.5H), 4.92-5.01(m, 0.4H), 6.87-8.04(m, 15H).3g 0.991-2.06(m, 16.7H), 2.14-2.38(m, 0.8H), 2.49-2.95(m, 2.5H), 3.47-3.72(m, 0.55H), 3.89-4.21(m, 1H), 4.23-4.46(m, 1.2H), 4.48-4.58(m, 0.2H), 4.59-4.70(0.37H), 4.72-4.82(m, 0.5H), 6.86-8.04(15H).______________________________________ EXAMPLE 4 ##STR50## Step A: Racemic N-(tert-Butoxycarbonyl)-3-(N'-[carbobenzoxy])piperidine To a solution of racemic N-Boc nipecotic acid (230 mg; 1 mmol) in toluene (12 ml) under nitrogen was added diphenylphosphoryl azide (DPPA) (259 μl; 1.2 mmol) and triethylamine (TEA) (170 μl; 1.22 mmol). The reaction was refluxed under nitrogen for one hour. The solvent was removed in vacuo, CH 2 Cl 2 (20 ml) and THF (20 ml) were added to the residue, followed by benzyl alcohol (115 μl; 1.5 mmol) and DMAP (122 mg; 1 mmol). The solution was refluxed overnight, and then concentrated in vacuo to yield a residue which was partitioned between H 2 O and EtOAc. The aqueous phase was extracted once more EtOAc, and the combined organic extracts was washed with 10% aqueous NaHCO 3 , H 2 O, 10% aqueous citric acid, H 2 O, saturated aqueous NaCl, dried (MgSO 4 ), filtered and evaporated. The crude oil was purified by silica gel radial chromatography eluted with EtOAc-hexanes (25:75) to yield 150 mg of the titled compound. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.3-1.5 (s, 11H), 1.61-2.15 (m, 3H), 2.19-2.58 (m, 2H), 2.67-2.87 (m, 1H), 2.91-3.11 (m, 1H), 3.31-3.60 (m, 1H), 5.17 (s, 2H), 7.00-7.60 (m, 5H). Step B: Racemic 3-(N-Carbobenzoxy)piperidine hydrochloride The titled compound was prepared from the product obtained in Step A using a procedure similar to that of Step E in Example 1. Purification yields 115 mg of the titled compound as a white solid. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.09-2.72 (m, 3H), 1.76-1.99 (m, 1H), 2.18-2.59 (m, 2H), 2.67-2.87 (m, 1H), 2.91-3.11 (m, 1H), 3.31-3.60 (m, 1H), 4.89-5.17 (s, 2H), 7.00-7.60 (m, 5H). CI-MS m/e: 235 (M+1). Step C: ##STR51## The product of Step B was coupled with Intermediate 1 as decribed in Step A of Example 3 to provide the desired compound (a mixture of diastereoisomer) as a white solid. 1 H-NMR (400 MHz, CD 3 OD, ppm): δ0.736-0.991 (m, 4H), 1.04-1.89 (m, 24H), 2.21-2.42 (m, 0.7H), 2.50-2.80 (m, 1.4H), 2.84-3.25 (m, 3.7H), 3.30-3.78 (m, 3H), 3.96-4.22 (m, 0.7H), 4.95-5.33 (m, 3.7H), 6.84-7.73 (m, 10H). ESI-MS m/e: 606 (M+1). Step D: The compound (50 mg) obtained in Step C was dissolved in dry ethylacetate (1ml) saturated with HCl(g) at room temperature. The mixture was stirred at that temperature for 1 h. The product was precepitated from the reaction with dry ether and filtered. The title compound was obtained as a hydrochloride salt (white solid). Yield 35 mg. 1 H-NMR (400 MHz, CD 3 OD, ppm): δ0.74-0.96 (m, 4H), 1.0-1.89 (m, 15H), 2.21-2.42 (m, 0.7H), 2.50-2.80 (m, 1.4H), 2.84-3.25 (m, 3.7H), 3.30-3.78 (m, 3H), 3.96-4.22 (m, 0.7H), 4.95-5.33 (m, 3.7H), 6.84-7.73 (m, 10H). ESI-MS m/e: 506 (M+1). EXAMPLE 5 ##STR52## Step A: N-(tert-Butoxycarbonyl)-(R)-nipecotic acid. To solution of racemic N-Boc-nipecotic acid (15 g) in ethylacetate (500 ml) was slowly added (S)-α-methyl benzylamine (12. 25 ml) at room temperature, and stirring continued at that temperature for 1 h. The precepitate formed was filtered, washed with ethylacetate (30 ml) and dried (10 g), and then crystallized from ethylacetate containing 10% methanol. The crystallized material was filtered, washed with ethyl acetate and dried. Yield: 7.6 g; mp: 176°-178° C. The ethyl acetate suspension of the salt was treated with aqueous 10% citric acid. The organic phase was then washed with water, dried (MgSO 4 ) and concentrated in vacuo to provide the pure R-acid as a white solid (5.1 mg). mp: 168°-169° C.; [α] D =+48.3° (c=1, MeOH). Step B: 3-(R)-(N-Carbobenzoxyl)piperidine hydrochloride The titled compound was prepared from the product (230 mg) obtained in Step A using a procedure similar to that described in Steps A and B of Example 4. Purification yields 115 mg of the titled compound as a white solid. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ1.09-2.72 (m, 3H), 1.76-1.99 (m, 1H), 2.18-2.59 (m, 2H), 2.67-2.87 (m, 1H), 2.91-3.11 (m, 1H), 3.31-3.60 (m, 1H), 4.89-5.17 (s, 2H), 7.00-7.60 (m, 5H). CI-MS m/e:235 (M+1). Step C: ##STR53## The above compound was prepared from the product of Step B using the procedure described in Step C of Example 4. 1 H-NMR (400 MHz, CD 3 OD, ppm): δ0.736-0.991 (m, 0.4H), 1.04-1.89 (m, 24H), 2.21-2.42 (m, 0.7H), 2.50-2.80 (m, 1.4H), 2.84-3.25 (m, 3.7H), 3.30-3.78 (m, 3H), 3.96-4.22 (m, 0.7H), 4.95-5.33 (m, 3.7H), 6.84-7.73 (m, 10H). ESI-MS m/e: 606 (M+1). Step D: ##STR54## To a solution of the titled compounds in Step C (320 mg; 0.531 mmol) in MeOH (10 ml) and CHCl 3 (200 μl), was added Pd/C (46 mg), and the mixture was stirred in an atmosphere of H 2 for two days. The mixture was then filtered through a pad of celite, and the filtrate was concentrated in vacuo to yield 260 mg of the titled compound. 1 H-NMR (300 MHz, CD 3 OD, ppm): δ0.053-0.404 (m, 0.15H), 1.02-1.81 (m, 20H), 1.85-2.07 (m, 0.4H), 2.11-2.46 (m, 1H), 2.74-3.21 (m, 4H), 3.78-4.11 (m, 0.7H), 4.21-4.43 (m, 0.2H), 4.92-5.20 (m, 1H), 6.81-7.96 (m, 5H). Step E: ##STR55## The product from Step D was reacted with appropriate sulfonyl chlorides, using the conditions described in Step D of Example 1, to provide the desired protected sulfonamides. The compounds were purified by silica-gel radial chromatography using EtOAc-hexanes (66:33) to yield the title compounds as a white solid. Step F:. ##STR56## The compounds prepared in Step E were deprotected with HCl/EtOAc, as described in Step B of Example 2, to provide titled compounds (Tables III and IV). The corresponding S-isomers (described in Tables III & IV) were made similarly starting with N-(tert-butoxycarbonyl)-(S)-nipecotic acid. N-(tert-butoxycarbonyl)-(S)-nipecotic acid was prepared from racemic N-BOC-neipecotic acid using (R)-α-methylbenzyl amine as the resolving agent as described in Step A. mp. 170°-171° C.; [α] D =-48.6° (c=1, MeOH). TABLE III______________________________________Isomer Cpd # R.sup.c CI-MS (M.sup.+) Mol. formula______________________________________R 5a Ph 512 C.sub.26 H.sub.33 N.sub.5 SO.sub.4S 5b Ph 512 C.sub.26 H.sub.33 N.sub.5 SO.sub.4R 5c quinol-8-yl 563 C.sub.29 H.sub.34 N.sub.6 SO.sub.4S 5d quinol-8-yl 563 C.sub.29 H.sub.34 N.sub.6 SO.sub.4______________________________________ TABLE IV______________________________________Cpd # .sup.1 H-NMRδ (400 MHz, CD.sub.3 OD, ppm)______________________________________5a 0.834-1.92(m, 11H), 2.14-2.51(m, 1H), 2.69-3.25(m, 5H), 3.46-3.70(m, 0.7H), 4.00-4.44(m, 0.7H), 4.69-4.84(m, 0.7H), 4.99-5.25(m, 0.6H), 6.82-8.03(m, 10H), 8.09- 8.47(0.3H).5b -0.102-0.147(m, 0.12H), 0.806-1.90(m, 10H), 2.07-2.35(m, 0.9H), 2.38-2.64(m, 0.8H), 2.67-2.91(m, 0.5H), 2.98-3.25 (m, 2.5H), 3.58-3.84(m, 0.46H), 4.01-4.32(m, 0.85H), 4.99- 5.26(m, 0.77H), 6.85-8.03(m, 10H), 8.08-8.37(m, 0.3H).5c 0.785-1.83(m, 13H), 2.39-2.68(m, 0.9H), 2.78-3.27(m, 4.5H), 3.88-4.12(m, 0.6H), 4.99-5.22(m, 0.5H), 6.69-7.56 (m, 5H), 7.66-8.11(m, 2H), 8.18-8.67(m, 2H), 8.70-8.87 (m, 0.5H), 8.89-9.12(m, 0.9H), 9.16-9.39(m, 0.4H).5d -0.10-0.305(m, 0.1H), 0.803-1.798(m, 11H), 2.37-3.25(m, 4.2H), 3.37-4.00(m, 1.3H), 4.97-5.19(m, 0.6H), 6.69-7.61 (m, 5H), 7.68-8.11(m, 2H), 8.16-8.77(m, 2.3H), 8.79-9.05 (0.9H), 9.07-9.36(m, 0.9H).______________________________________ ##STR57## To a solution of 20 mg of Intermediate 1, 0.020 mL of N-methylmorpholine, 20 mg of EDC and 20 mg of HOBT in 2 mL of CH 2 Cl 2 was added 11 mg of 3-(5-ethyl-1,2,4-oxadiazolyl)piperidine hydrochloride and stirred for a day at room temperature (the piperidine hydrochloride was prepared in 3 steps from N-t-BOC protected 3-cyanopiperidine by a) addition of hydroxylamine to the nitrile in refluxing methanol, b) acylation of the amino-oxime with propionylchloride in pyridine, and c) deprotection of the N-t-BOC protecting group with HCl (gas) in ethyl acetate). The reaction mixture was poured into 5 mL of CH 2 Cl 2 and washed with (2×3 mL) of 0.50N HCl solution, 3 mL of 1N aqueous sodium hydroxide solution, dried over anhydrous magnesium sulfate, filtered and concentrated to give a thick oil. Flash chromatography of this material (10 g silica gel; hexane:acetone (5:1) as the eluent) gave 13.6 mg of the coupled product as a diastereomeric mixture. This material was deprotected by treating an EtOAc solution with dry HCl (gas) for 5 min. Ether was added and the precipitate was collected under nitrogen and dried. The title compound was a white to off-white solid. FAB-MS m/e: 453.59 (M+1). EXAMPLE 7 ##STR58## Step A: ##STR59## The title compound was prepared by the methodology of Example 2, Step A. Step B: ##STR60## To a solution of the amine from Step A (300 mg; 1.1 mmol) in CH 2 Cl 2 (5.0 mL) was added triethylamine (1.5 mL; 10.8 mmol), DMAP (catalytic) and acetic anhydride (0.5 mL; 5.4 mmol). The mixture was refluxed until complete by TLC analysis whereupon the reaction was diluted with ethyl acetate, washed with 2N HCl, saturated potassium carbonate, water, brine, dried (K 2 CO 3 ) and concentrated. Radial chromatography (2 mm plate; 4;1 hexanes:ethyl acetate) of the residue gave the compounds of Table V. The sulfonamides of Table V (7B-6 to 9) were prepared essentially in the manner described in Example 1, Step D using known sulfonyl chlorides. TABLE V______________________________________Example # R.sup.d Mass Spectral Data______________________________________7B-1 hydrogen --7B-2 ##STR61## 218.2 (MH.sup.+ CO.sub.2 -t-Bu)7B-3 ##STR62## 247.2 (MH.sup.+ CO.sub.2 -t-Bu)7B-4 ##STR63## 287.3 (MH.sup.+ CO.sub.2 -t-Bu)7B-5 ##STR64## 281.2 (MH.sup.+ CO.sub.2 -t-Bu)7B-6 SO.sub.2 CH.sub.3 255 (MH.sup.+ CO.sub.2 -t-Bu)7B-7 SO.sub.2 Ph --7B-8 SO.sub.2 CH(CH.sub.3).sub.2 283 (MH.sup.+ CO.sub.2 -t-Bu)7B-9 SO.sub.2 -t-Bu 297 (MH.sup.+ CO.sub.2 -t-Bu)7B-10 C(O)NH.sub.2 (ND)7B-11 C(O)NHCH.sub.3 (ND)7B-12 C(O)NHCH(CH.sub.3).sub.2 (ND)7B-13 C(O)NHPh (ND)______________________________________ Step C: ##STR65## The appropriate N-BOC derivatives were deprotected in the general manner described herein with trifluoroacetic acid in dichloromethane at 0° C. to give the amine salts of Table VI. TABLE VI______________________________________Example # R.sup.d Mass Spectral Data______________________________________7C-1 hydrogen --7C-2 ##STR66## 219.2 (MH.sup.+)7C-3 ##STR67## 246.33 (MH.sup.+)7C-4 ##STR68## 287.3 (MH.sup.+)7C-5 ##STR69## 281.2 (MH.sup.+)7C-6 SO.sub.2 CH.sub.3 255 (MH.sup.+)7C-7 SO.sub.2 Ph --7C-8 SO.sub.2 CH(CH.sub.3).sub.2 283 (MH.sup.+)7C-9 SO.sub.2 -t-Bu 297 (MH.sup.+)7C-10 C(O)NH.sub.2 (ND)7C-11 C(O)NHCH.sub.3 (ND)7C-12 C(O)NHCH(CH.sub.3).sub.2 (ND)7C-13 C(O)NHPh (ND)______________________________________ ##STR70## To a solution of the appropriate amine salt (1 equivalent) from Step C in dichloromethane was added N-methyl morpholine (1 equivalent) and the mixture was stirred 10 minutes. To this mixture was added d-TRP-BocAIB (1 equivalent), HOBT (1 equivalent) and EDCI (2 equivalents). The reaction was stirred until complete by TLC analysis whereupon the reaction was worked up in the general manner described herein and the chromatographed in the general manner described herein to give the compounds of Table VII. TABLE VII______________________________________Example # R.sup.d Mass Spectral Data______________________________________7D-1 hydrogen 548.3 (MH.sup.+)7D-2 ##STR71## 514.7 (MH.sup.+ O-t-Bu)7D-3 ##STR72## 544.3 (MH.sup.+ O-t-Bu)7D-4 ##STR73## 584.4 (MH.sup.+ O-t-Bu)7D-5 ##STR74## 578.3 (MH.sup.+ O-t-Bu)7D-6 SO.sub.2 CH.sub.3 526 (MH.sup.+ CO.sub.2 -t-Bu)7D-7 SO.sub.2 Ph --7D-8 SO.sub.2 CH(CH.sub.3).sub.2 554 (MH.sup.+ CO.sub.2 -t-Bu)7D-9 SO.sub.2 -t-Bu 568 (MH.sup.+ CO.sub.2 -t-Bu)7D-10 C(O)NH.sub.2 (ND)7D-11 C(O)NHCH.sub.3 (ND)7D-12 C(O)NHCH(CH.sub.3).sub.2 (ND)7D-13 C(O)NHPh (ND)______________________________________ Step E: ##STR75## The appropriate N-BOC derivatives from Step D were deprotected in the general manner described herein with trifluoroacetic acid in dichloromethane at 0° C. to give the amine salts of Table VIII. TABLE VIII______________________________________Example # R.sup.d Mass Spectral Data______________________________________7E-1 hydrogen 448.3 (MH.sup.+)7E-2 ##STR76## --7E-3 ##STR77## 518.2 (MH.sup.+)7E-4 ##STR78## 558.3 (MH.sup.+)7E-5 ##STR79## 552.3 (MH.sup.+)7E-6 SO.sub.2 CH.sub.3 526 (MH.sup.+)7E-7 SO.sub.2 Ph --7E-8 SO.sub.2 CH(CH.sub.3).sub.2 554 (MH.sup.+)7E-9 SO.sub.2 -t-Bu 568 (MH.sup.+)7E-10 C(O)NH.sub.2 (ND)7E-11 C(O)NHCH.sub.3 (ND)7E-12 C(O)NHCH(CH.sub.3).sub.2 (ND)7E-13 C(O)NHPh (ND)______________________________________ While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols may be made without departing from the spirit and scope of the invention. For example, effective dosages other than the particular dosages as set forth herein above may be applicable as a consequence of variations in the responsiveness of the mammal being treated for any of the indications with the compounds of the invention indicated above. Likewise, the specific pharmacological responses observed may vary according to and depending upon the particular active compounds selected or whether there are present pharmaceutical carriers, as well as the type of formulation and mode of administration employed, and such expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.

The present invention is directed to certain novel compounds identified as 3-substituted piperidines of the general structural formula: ##STR1## wherein R 1 , R 1a , R 2a , R 4 , R 5 , A, X, and Y are as defined herein. These compounds promote the release of growth hormone in humans and animals. This property can be utilized to promote the growth of food animals to render the production of edible meat products more efficient, and in humans, to treat physiological or medical conditions characterized by a deficiency in growth hormone secretion, such as short stature in growth hormone deficient children, and to treat medical conditions which are improved by the anabolic effects of growth hormone. Growth hormone releasing compositions containing these compounds as the active ingredient thereof are also disclosed.

BACKGROUND OF THE INVENTION 1. Field of the Invention This is a continuation of co-pending application Ser. No. 447,581, U.S. Pat. No. 4,828,912, filed on Dec. 13, 1982, which is a continuation-in-part of Ser. No. 392,781, now abandoned, filed June 30, 1982, which is a continuation-in-part of Ser. No. 264,688, filed July 20, 1981, now abandoned. This invention relates to a class of virucidal compositions highly efficacious against common respiratory viruses such as rhinoviruses, parainfluenza viruses, and adenoviruses and the methods and products utilizing such compositions. In particular, the invention relates to a novel type of virucidal composition which can be applied to a variety of substrates or carriers such as cellulosic webs, nonwoven structures, and textile-based materials. In addition, the class of virucidal compositions comprising this invention may also be incorporated into nasal sprays, facial creams, hand lotions, lipsticks, and similar cosmetic preparations. The compositions may also be used as ingredients in kitchen and bathroom cleansers, furniture and floor polishes, and similar household preparations. Virologists knowledgeable in the field of respiratory viruses generally agree that rhinoviruses, influenza viruses, and adenoviruses are among the most important group of pathogenic agents which cause respiratory illnesses. Rhinoviruses, in particular, are thought to be the principle causative agent of what is generally known as "the common cold". Rhinovirus, which cause cold symptoms, belongs to the picornavirus family. This family lacks an outer envelope, and therefore, is characterized as "naked viruses". Although more than 100 different antigenic types of rhinoviruses are known, they share certain centrally important attributes. For instance, all are endowed with ether-resistant capsids, all are acid labile, and all contain single-stranded RNA (ca. 2.6×10 6 daltons). All are difficult to inactivate by common germicides such as quaternary ammonium compounds. Adenoviruses include more than thirty antigenic types. When they invade the respiratory tract, they cause inflammation of the tissues leading to symptoms of pharyngitis, bronchitis, etc. While most adenovirus infections occur in childhood, infections of adults are far from uncommon. Like rhinoviruses, adenoviruses lack an envelope, (i.e. naked) but the adeno-nucleus, in contrast to the rhino-nucleus, contains a double-stranded DNA, and are not characterized as acid labile. Adenoviruses are unusually resistant to inactivation. Parainfluenza viruses, which belong to the paramyxovirus family, play an important role in the occurrence of lower respiratory diseases in children and upper respiratory diseases in adults. The parainfluenza viruses are RNA-containing viruses endowed with an ether-sensitive, lipoprotein envelope surrounding the nucleocapsid. These viruses are resistant to inactivation by carboxylic acids in low concentrations. Recent work by Dick and others [Dick, E. C. and Chesney, P. J., "Textbook of Pediatric Diseases", Feigin, R. D. and Cherry, J. D. ed., Vol. II, p. 1167 (1981) W. B. Saunders Pub. Co., Phila., PA] has thrown considerable light on the mode of transmission of respiratory diseases caused by rhinoviruses. Although the exact mode of transmission of respiratory diseases is not fully understood, field studies by the above investigators have provided persuasive evidence that effective transmission of diseases such as common cold usually requires close association or contact--direct or indirect--between the infected subject and the potential victim. (Indirect contact may be looked upon as contact occurring via an intervening surface, e.g., table top, door knob, etc.) Thus, it may be possible to interrupt the chain of infection and reduce its potential to spread, if the viruses can be rendered ineffective as they emerge from an infected person's nose or mouth by immediate exposure to a virucidal agent. Moreover, after emergence, viruses which may ensconce themselves on the infected person's face or hands may also be "killed" if a suitable virucidal agent is quickly brought into contact with the appropriate anatomical surface, i.e., face, hands, etc. A facial tissue, containing a fast-acting, efficacious virucidal composition would offer a simple means of accomplishing the tasks mentioned above. A long-felt need has existed for a safe and inexpensive virucidal agent effective against common respiratory viruses. Simple household germicides are not effective against rhino- and adenoviruses. 2. Description of the Prior Art U.S. Pat. No. 4,045,364 to Richter discloses a disposable paper impregnated with an iodophor (i.e. iodine and a carrier) having germicidal properties and useful as a pre-wash in a surgical scrub routine. The patentee discloses that the stability of the iodophor is enhanced at a lower pH and that small quantities of weak organic acids such as citric acid or acetic acid can be added to achieve pH control. U.S. Pat. No. 3,881,210 to Drach et al describes a pre-moistened wiper for sanitary purposes which can include a bactericide. U.S. Pat. No. 3,654,165 to Bryant et al discloses a cleaner/sanitizer for wiping purposes including iodine providing bactericidal action. U.S. Pat. No. 3,567,118 to Shepherd et al discloses a fibrous material for cleaning purposes having a coating of a hydrophilic acrylate or methacrylate containing, inter alia, a bactericide. While the prior art has disclosed that iodine compositions and products have a wide-spectrum virucidal effect, there has yet to be developed commercially an inexpensive product that successfully interrupts the spread of viruses such as rhinovirus or influenza virus. Problems with iodine result, for example, from its toxicity, and the fact that it is an irritant for animal tissue. The action of iodine is non-selective as between bacterial and mammalian protein, and its uncontrolled use upon the skin may cause severe irritation. Further, its activity may be diminished or neutralized by the action of biological fluids such as blood serum. Efforts to modify iodine to avoid these difficulties have not been completely successful. References exist in the literature on the bactericidal action of acids such as citric, [e.g., Reid, James D., "The Disinfectant Action of Certain Organic Acids", American Journal of Hygiene, 16, 540-556 (1932)]. However, virucidal action is fundamentally different from bactericidal action in that viruses and bacteria represent different microorganisms with different characteristics. For instance, viruses do not replicate outside host cells whereas bacteria do. Quaternary ammonium compounds such as benzalkonium chloride are often effective against bacteria but not against viruses such as the various rhinoviruses. Although it is known that rhinoviruses are labile to aqueous solutions of acids under low-pH conditions [e.g. Davis, B. D. et al; "Microbiology" p. 1303. Harper E. Row (Publishers) New York, 1973 and Rueckert, R.R., "Picornaviral Architecture" Comparative Virology--Academic Press, New York (1971), pp. 194-306], known references do not mention the utilization of this concept in epidemiological contexts such as interruption of the chain of infection caused by rhinoviruses. To the best of our present knowledge the only systematic study of the virucidal action of organic acids (citric, malic, etc.) which exists in the generally available literature, was carried out by Poli, Biondi, Uberti, Ponti, Balsari, and Cantoni [Poli, G. et al: "Virucidal Activity of Organic Acids" Food Chem. (England) 4(4)251-8 (1979)]. These workers found that citric, malic, pyruvic and succinic acids, among others, were effective against herpesvirus, orthomyxovirus and rhabdovirus (Rabies virus). Their experiments were carried out at room temperature with aqueous solutions of pure acids. No substrate or carrier was used. The three viruses chosen for study by these workers were all "enveloped" viruses, resembling, in that regard, parainfluenza 3. Poli et al also observed that these acids were not effective against adenovirus which, it will be recalled, is a "naked" virus. Based on this, they concluded that these acids were effective against "enveloped" viruses but not against "naked" viruses. It is known to those skilled in the art that adenoviruses are resistant to acids. Archiv fur Libensmittelhygiene 29, 81-120 (1978) reports a strain of adenoviruses to be susceptible to certain disinfectant surface active agents in aqueous solution. There is no suggestion, however, of combining such disinfectant surface active agents with an organic acid or with a substrate or carrier. SUMMARY The present invention provides a virucidal composition, the method of use and the product therefor which are highly effective over a broad spectrum of viruses and yet can be produced and used with safety. We have discovered that when at least one or more genus of a respiratory virus is contacted with an effective amount of a virucidal composition comprising a carboxylic acid having the formula R--COOH and explained hereinbelow in greater detail, the virus is substantially inactivated thereby interrupting and preventing the spread of the virus. These acids, which may be used in combination with a surfactant as discussed below, inactivate certain respiratory viruses, enveloped (e.g. parainfluenza) and naked (e.g. rhinovirus and adenovirus). A suitable carrier or substrate, such as facial tissue or a nonwoven web, incorporating such compositions is particularly useful in preventing the spread of virus. In general, these compositions and products can be handled without difficulty and are not believed to have any harmful effects when used in accordance with the invention. The compositions have little or no deleterious effects on color, odor, strength, or other important properties of the substrate or carrier. The products, for example, may be used as a dry wipe or maintained moist and used as a wet wipe. DESCRIPTION OF THE PREFERRED EMBODIMENTS While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. The present invention results from the unexpected discovery that certain acids such as citric, malic, succinic, and benzoic, used in suitable concentrations, as further described herein, are highly efficacious against rhinoviruses 16, 1A, and 86. When used in the presence of a surfactant such as sodium dodecyl sulfate (SDS), these acids were found to be effective also against parainfluenza 3 and adenovirus 5. In general, the water soluble carboxylic acids useful in accordance with the invention have the following structure: R--COOH Wherein R may be represented by: lower alkyl; substituted lower alkyl; hydroxy lower alkyl (e.g. HOCH 2 --); carboxy lower alkyl (e.g HOOC--CH 2 --CH 2 --); carboxy, hydroxy lower alkyl (e.g., HOOCCH 2 CHOH--); carboxy, halo lower alkyl (e.g. HOOCCH 2 CHBr--); carboxy, dihydroxy lower alkyl, (e.g. HOOC--CHOH--CHOH--); dicarboxy, hydroxy lower alkyl ##STR1## lower alkenyl, carboxy lower alkenyl (e.g. HOOCCH═CH--), dicarboxy lower alkenyl ##STR2## phenyl (e.g. C 6 H 5 --); substituted phenyl (e.g. hydroxy phenyl HO--C 6 H 4 --). Other acid examples include hydroxy lower alkyl, e.g. lactic; carboxy, hydroxy lower alkyl, e.g. 2-methyl malic; carboxy, halo lower alkyl, e.g. 2-chloro-3-methyl succinic; carboxy, dihydroxy lower alkyl, e.g. 2-methyl tartaric, dicarboxy, hydroxy lower alkyl, e.g. 2-methyl citric acid, and carboxy lower alkenyl, e.g. fumaric. The above definitions are used in an illustrative but not a limiting sense. The term "lower" as used herein refers to an acid where "R" contains one to six carbon atoms. The term "substituted" indicates that one or more hydrogen atoms are substituted by halogen atoms (F, Cl, Br, I) hydroxyl groups, amino groups, thiol groups, nitro groups, cyano groups, etc. The surfactant may be nonionic (e.g., the polyoxyethylenated alkylphenols such as TRITON X-100®, manufactured by Rohm and Haas; the polyoxyethylenated sorbitol esters such as TWEEN 40®, manufactured by ICI United States, Inc.), cationic (e.g. cetylpyridinium chloride (C 5 H 5 N + (CH 2 ) 15 CH 3 Cl - ), methylbenzethonium chloride (Me.sub.3 CCH.sub.2 C(Me).sub.2 C.sub.6 H.sub.3 (Me)-OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 .sup.+ N (Me).sub.2 CH.sub.2 C.sub.6 H.sub.5 Cl.sup.- or anionic (e.g., sodium dodecyl sulfate, (CH 3 (CH 2 ) 10 --CH 2 OSO 3 --Na), the 1,4-bis (2-ethylhexyl) ester, sodium salt of sulfosuccinic acid, as manufactured by American Cyanamid Company under the tradename of AEROSOL OT. The preferred anionic surfactants may be represented by the structures: 1. (ROSO.sub.3).sub.x M.sup.+ or (RSO.sub.3).sub.x M.sup.+ wherein, M + is a mono, di or trivalent metal cation or an ammonium or substituted ammonium ion; x is an integer; and R is an alkyl group. ##STR3## wherein, M + and x are defined as above and R 1 and R 2 may be the same or different and may be represented by straight or branched chain aliphatic groups. The above anionic surfactants are presented in an illustrative rather than a limiting sense. Surfactants, in general, are not virucidal with respect to naked viruses such as rhinovirus. Although the invention is not limited to the use of a cellulosic web (such as facial tissue, bathroom tissue, hand towels for washroom and other uses and the like) as the substrate or carrier for the virucidal agents, a facial tissue impregnated with these novel virucidal agents sufficiently illustrates the underlying principle and represents a simple and useful embodiment of the invention. For this reason, the experiments described in the paragraphs which follow were carried out using facial tissues as the substrate. Examples of suitable nonwoven substrates are wet wipe materials such as wet-creped hand towels and spunbonded and meltblown polymeric webs commonly used in production of disposable hospital items such as surgical drapes, gowns, bedsheets, pillowcases, and the like. Other examples of nonwovens include composites of natural and/or synthetic fibers, formed by turbulent admixing, in nonwoven form. Textile materials of all types, including laminates of different materials, may be used as suitable substrates. For example, hygienic face masks used by persons suffering from respiratory illnesses provide an excellent means for utilizing the present invention. Other essentially inert carriers i.e., those which are essentially non-toxic and non-irritating to human or animal tissue under the conditions of normal use, will be apparent to those skilled in the art for applications such as lotions, sprays, creams, polishes and the like. In general terms, the experimental procedure for preparing the samples in the examples below was simple and straightforward. Three-ply KLEENEX® facial tissues (11 inches×12 inches; basis weight: ca. 26 lb/2880 ft. 2 for all three plies combined) were impregnated with aqueous solutions of citric, malic, succinic, and benzoic acids by simple dipping. The acids were used either singly or as homogeneous mixtures. Usually the impregnating solution also contained a small percentage of a surfactant such as Aerosol--OT-- [sodium salt of 1,4-bis(2- ethylhexyl) ester of sulfosuccinic acid, manufactured by American Cyanamid], or sodium dodecyl sulfate. In certain instances, a small amount of glycerol was also used to enhance tissue softness. The saturated tissues were pressed between rolls to squeeze out excess saturant and ensure uniformity of saturation. The tissues were weighed, dried, and the degree of saturation (i.e. percent saturant pick-up) was computed. The tissues were then ready for the testing of virucidal efficacy. The procedure adopted for testing virucidal efficacy is in accord with standard virological assay techniques (TCID 50 ) with simple variations necessitated by the presence of the cellulosic substrate. A description of the procedure follows: VIRUCIDAL ASSAY PROCEDURE I. Materials A. Solutions ______________________________________1. Neutralizing Solution6.4 ml 2M Na.sub.2 HPO.sub.41.2 ml 1.0 M Citric Acid92.4 ml 1X Medium 199 (nutrient medium for tissue culture)McIlvaine Salt Solution (HMSS)2.0 ml 1.0 Citric Acid Diluted to 2 liters18.0 ml 2.0 M Sterile Na.sub.2 HPO.sub.4 with Hanks' BalancedThe pH of this Solution is 7.0 Salt Solution.3. Hanks' Balanced Salt Solution g/liter in double-distilled waterNaCl 8.0KCl 0.4MgSO.sub.4.7H.sub.2 O 0.2CaCl.sub.2 (anhydrous) 0.14Na.sub.2 HPO.sub.4.2H.sub.2 O 0.06KH.sub.2 PO.sub.4 (anhydrous) 0.06Glucose 1.0Phenol red 0.005NaHCO.sub.3 0.35______________________________________ Note: The above solutions are not virucidal. B. Viruses and Tissue Culture Cell Lines 1. Rhinovirus type 16, type 1A and type 86: Rhinovirus types 16, 1A, and 86 (RV 16, 1A and 86 respectively) are grown in Ohio State HeLa (O-HeLa) tissue culture cells and stored at -60° F. until they are used. The virucidal testing involving the rhinoviruses is done using O-HeLa tissue culture test tubes incubated on a roller drum apparatus at 33° C. 2. Parainfluenza type 3: Parainfluenza type 3 (Para 3) grown in rhesus monkey kidney tissue culture cells and stored at -60° F. until it is used. The virucidal testing involving Para 3 virus is done using O-HeLa tissue culture test tubes incubated in a stationary position at 33° C. 3. Adenovirus type 5: Adenovirus type 5 (Adeno 5) is grown in HEp-2 tissue culture cells and stored at 60° F. until it is used. The virucidal testing involving adeno 5 virus is done using Human Epitheleal Carcinoma--2 (HEp-2) tissue culture test tubes incubated in a stationary position at 37° C. II. Methods A. Virucidal Testing A 1:1 (volume:volume) mixture of virus and saliva is prepared. A one-square inch sample is cut out of treated Kimberly-Clark KLEENEX® tissue and placed in a plastic Petri dish. (A treated tissue is tissue impregnated with the virucidal agent under investigation.) The virus - saliva mixture (0.1 ml) is pipetted directly onto the sample and allowed to react for one minute. Note this is a two-fold virus dilution. After the reaction time of one minute, 5 ml of neutralizing solution is pipetted onto the sample in the Petri plate and agitated for 3 seconds. This is now a 100-fold virus dilution. The neutralizing solution - virus - saliva mixture is then pipetted out of the Petri plate and added to a tube containing 5 ml of Hanks' - McIlvaine Salt Solution. The sample is added to the same tube by tipping the plate and using the tip of a pipette to push it into the tube. The tube containing the 10 ml of solutions and the sample is vortexed for 30 seconds. This tube contains a 10 -2 .3 or 1:200 dilution of virus. Ten-fold serial dilutions (fresh pipette for each dilution) are made from the 10 -2 .3 dilution by taking 0.3 ml of the previous dilution and adding it to 2.7 ml of Hanks' - McIlvaine Salt Solution. 0.1 ml is inoculated into each tissue culture test tube. Generally two tubes are inoculated per dilution. For each experiment two sets of controls are used. The first may be termed "the virus control" as it is designed to check the infectivity of the virus suspension itself without saliva or the tissue substrate. The virus suspension is diluted serially 10-fold in HMSS. 0.1 ml of specific dilutions are inoculated per tissue culture cell test tube. The information obtained from this control gives the number of infectious virus units that are contained in the virus solution that has been stored at -60° F. and insures that the aliquot of virus solution used in the experiment has not lost infectivity during the freezing, storage, or thawing processes. The second control, "the tissue control", consists of performing the virucidal testing experiment using one square inch of an untreated KLEENEX® tissue. The information obtained from this control gives the number of infectious virus units that can be recovered from an untreated one inch square wipe following the virucidal testing procedure. The inoculated tissue culture tubes are examined for seven days for evidence of viral infection. The endpoint of a virucidal test for a given wipe is that dilution of virus which infects actually or is calculated to infect only one of the two inoculated tubes. This number is defined as tissue culture infective dose, or TCID 50 . The results of the virucidal activity of a given wipe are usually given as the "log difference" between the common log of the TCID 50 result of the treated sample subtracted from the common log of the TCID 50 of the untreated sample. The virucidal efficacy of a sample may be derived from the "log difference" in the following manner: E1 ? ##STR4## Where: X=the initial concentration of the virus (infectious units/0.1 ml) of untreated sample used as control. Y=the final concentration of the virus (infectious units/0.1 ml) of the treated sample. The following examples explain the computation procedure. (In the experiments, the final virus concentration was always less than or equal to 10 2 .3 infectious units/0.1 ml.) For the majority of the results, the final virus concentration was less than 10 2 .3. With an initial virus concentration of 10 6 .3, this would signify a log difference greater than 4 and a "kill" of greater than 99.99%). ______________________________________1. Initial Concentration: X = 10.sup.6.3Final Concentration: Y = 10.sup.2.3Log Difference = (log 10.sup.6.3 - log 10.sup.2.3) = 4 ##STR5##2. Initial Concentration: X = 10.sup.4.8Final Concentration: Y = 10.sup.2.3Log Difference = 2.5 ##STR6##______________________________________ The procedure outlined above is in conformity with standard microbiological assay techniques. It yields reliable and reproducible results within the limits of variability associated with biological experiments. RESULTS The results are shown in Tables I, II, and III. The data in Table I show that simple organic carboxylic acids such as citric, malic, tartaric, succinic and substituted derivatives thereof (e.g. 2-bromo- succinic), and benzoic acid and its substituted derivatives (salicylic acid), used in a facial tissue in suitable concentrations, are highly virucidal against rhinovirus 16 and parainfluenza 3. Furthermore, the data in Table I show that, when used in conjunction with a surfactant such as Aerosol OT or sodium dodecyl sulfate, the concentrations of the acids in the facial tissue may be lowered without sacrificing virucidal efficacy. Table II lists the results of experiments with acid mixtures chosen from the group citric, benzoic, succinic, and malic. The data show that the facial tissues treated with the acid mixtures are virucidal against rhinovirus 16 and parainfluenza 3. The data on Table II show that the facial tissue impregnated with a mixed acid system such as citric and malic and an appropriate surfactant such as SDS, is efficacious against rhinovirus 16, 1A and 86 and adenovirus 5. As these examples demonstrate, in accordance with the present invention, simple organic acids such as citric/malic/succinic, when used in conjunction with a suitable surface-active agent such as SDS, are highly virucidal against common respiratory viruses of which rhinovirus 16, 1A and 86, parainfluenza 3, and adenovirus 5 are typical examples. In addition, products using facial tissues as the means of deployment of the virucidal compositions mentioned are highly effective. The significance of the invention resides in the fact that it provides the basis for interrupting the chain of infection caused by respiratory viruses. As viruses do not replicate outside the host cell, the degree of inactivation demonstrated in the experiments offers a simple and practical means of reducing the virus concentration in the vicinity of a person infected with a respiratory virus. This, in turn, significantly reduces the potential of the infection to spread. TABLE I__________________________________________________________________________VIRUCIDAL EFFICACY OF SINGLE ACIDS AGAINST RHINOVIRUS 16 ANDPARAINFLUENZA 3 VIRUS (EXPOSURE TIME OF ONE MINUTE) Virucidal EfficacyExample No. Virucidal Composition.sup.a Surfactant.sup.a Rhinovirus 16 Parainfluenza 3__________________________________________________________________________1 Citric Acid (23.2%) None >99.99% >99.7%2 Citric Acid (18.7%) None >99.99%3 Citric Acid (9.7%) AOT.sup.b (1%), SDS.sup.c (1%) 99.99%4 Citric Acid (9.4%) SDS (1%) >99.99% >99.99%5 Succinic Acid (20%) None >99.99%6 Succinic Acid (9.1%) SDS (2%) >99.99% >99.99%7 2-Bromosuccinic Acid (10.4%) SDS (1%) >99.99%8 Malic Acid (9.4%) AOT (0.5%) 99.99% >99.99%9 Tartaric Acid (15%) None >99.99%10 Benzoic Acid (30%) None >99.99%11 Salicyclic Acid (18%) None >99.99%12 Salicyclic Acid (9%) None >99.99%__________________________________________________________________________ .sup.a The figures in parentheses represent percent chemical used based o the weight of the facial tissue. .sup.b AEROSOL, OT ®, the sodium salt of the 1,4bis (2ethylhexyl) ester of sulfosuccinic acid. .sup.c Sodium dodecyl sulfate. TABLE II__________________________________________________________________________VIRUCIDAL EFFICACY OF MIXED ACIDS AGAINST RHINOVIRUS 16 ANDPARAINFLUENZA 3 VIRUS (EXPOSURE TIME OF ONE MINUTE): Virucidal Composition* Citric Benzoic Malic Succinic Virucidal EfficacyExample No. Acid Acid Acid Acid Surfactant.sup.a Rhinovirus 16 Parainfluenza 3__________________________________________________________________________13 10.7 0.2 -- -- AOT.sup.b (1) >99.99 >99.9714 10.3 0.2 -- -- AOT (1) >99.99 >99.9715 10.1 0.2 -- -- AOT (1) >99.99 >99.9716 7.1 0.2 -- -- AOT (1) >99.99 >99.9917 8.8 0.2 -- -- AOT (1) >99.99 >99.9918 10.3 -- -- 5.2 AOT (1) >99.99 >99.9719 10.0 -- -- 5.0 AOT (1) >99.99 >99.9720 10.0 -- -- 5.0 AOT (1) >99.99 >99.9721 10.4 -- 5.2 -- AOT (1) >99.99 >99.9922 10.5 -- 5.3 -- AOT (1) >99.99 >99.9723 10.3 -- 5.2 -- AOT (1) >99.99 >99.9724 10.2 -- 5.1 -- AOT (1) >99.99 >99.9725 11.1 -- 5.6 -- AOT (0.5) >99.99 >99.726 10.6 -- 5.3 -- AOT (1) >99.99 >99.727 11.1 -- 5.6 -- AOT (0.5) >99.99 >99.728 10.6 -- 5.3 -- AOT (1) >99.99 >99.7029 4.8 -- 4.8 -- AOT (1) >99.99 >99.9930 13.8 -- -- 5.0 TX 100.sup.c (2) >99.99 >99.9931 5.7 -- 5.7 -- SDS.sup.d (2) >99.97 >99.9032 -- 0.2 9.7 -- SDS (2) 99.97 >99.90__________________________________________________________________________ .sup.a The figures in paraentheses represent percent chemical used based on weight of the facial tissue. .sup.b AEROSOL OT ®- .sup.c TRITON X100 ®- .sup.d Sodium dodecyl sulfate .sup.* The figures represent percent chemical used based on the weight of the facial tissue. TABLE III__________________________________________________________________________VIRUCIDAL EFFICACY OF MIXED ACIDS AND SDS AGAINST RHINOVIRUS 16,RHINOVIRUS 1A, RHINOVIRUS 06 AND ADENOVIRUS 5 (EXPOSURE TIME OF ONEMINUTE) Virucidal Composition.sup.a Citric Malic Surfactant Virucidal EfficacyExample No. Acid Acid SDS.sup.b Rhinovirus 16 Rhinovirus 1A Rhinovirus 06 Adenovirus 5__________________________________________________________________________33 10.0 5.5 2.2 >99.99 -- -- 99.9034 11.2 5.7 2.3 >99.99 -- -- 99.9035 11.4 5.8 2.3 >99.99 -- -- 99.7036 10.8 5.5 2.2 >99.99 -- -- 99.9937 11.2 5.7 2.3 >99.99 -- -- 99.9938 10.0 5.0 2.0 >99.99 >99.9 >99.9 99.90__________________________________________________________________________ .sup.a The figures represent percent chemical used based on the weight of the facial tissue. .sup.b Sodium dodecyl sulfate. In order to more specifically illustrate the improved effects obtained in accordance with the invention, additional examples were carried out varying the concentration of selected acid compositions and measuring virucidal activity at one and five minutes. These results are summarized in Table IV. In general, the acid compositions within the scope of the invention are virucidally effective to a high degree e.g., in the case of rhinoviruses or parainfluenza viruses, they produce a log drop of 2 or greater inactivation in one minute or less. For adenoviruses the time will be five minutes or less. In general, the degree of inactivation is greater after five minutes than after one minute as would be expected. Certain minor inconsistencies appear in the reported results due to the margin of error and the nature of the test procedure. It will be recognized by those skilled in this art that effectiveness is also influenced by the amount of the composition available for contact with the virus which, in turn, depends on the nature of the carrier. For example, as shown in Table IV, below, a relatively thick carrier with large voids such as wool may be ineffective unless treated with large amounts of the composition. On the other hand, a lightweight, relatively closed structure such as tissue or nonwoven material will require less of the composition. Based on the tests described, however, the effectiveness of a given combination of composition and carrier may be determined. For example, as shown in Table IV, citric acid is effective at concentrations tested from 5% to 10% add-on. The procedure used is described below. For these examples TCID 50 results were obtained using WI-38 cells of low passage from Flow Laboratories, Inc. which were initially passed at least once to insure growth potential. The bottles were then split 1:2 and seeded in 96-well cluster tissue culture plates with a flat bottom growth area of 0.32 cm 2 obtained from M A Bioproducts. The cells were incubated at 37° C. in 5% CO 2 and, after 24 hours, were usually 80 to 90% sheeted and normal in appearance before use in the assay. The medium (2% MM) used for both dilutions and maintenance of the cells was MEM Eagles with Earles BSS (with glutamine, gentamicin sulfate and 2% fetal calf serum added). Rhinovirus 1A was obtained from the National Institute of Allergy and Infectious Diseases, Bethesda, Md. A vial was grown in WI-38 cells and harvested after showing 4 + cytopathogenic effect (CPE) at 2 days post inoculation. The virus was harvested, aliquoted, and frozen at -70 ° C. and later titered in WI-38 cells in 96-well cluster plates. For the assay, the medium was removed from the plates by placing sterile gauze between the plate and the cover and turning the plate over. All six wells used received 0.1 ml of 2% MM. To the wells which were to be used as cell controls, another 0.1 ml of 2% MM was added. To the cells which were to receive the compounds, 0.1 ml of the appropriate dilution of material was added to each of six wells. The stock virus was mixed 1:1 with 2% MM for the initial dilution. One hundred microml. of this virus dilution were then added to a treated disc in a Petri dish. The virus was applied evenly over a tissue disc using a microliter syringe. The virus was allowed to remain on the disc for 1 minute or 5 minutes, then 5 ml of 2% MM was added to the disc in the Petri dish and the disc was slightly agitated. The disc and the solution were removed and placed in a sterile tube and agitated by vortexing for 30 seconds, representing the first dilution. Three ten-fold dilutions were made from the original tube and 0.1 ml of all four dilutions were added to the mono-layered WI-38 cells. Six wells were used for each dilution. Untreated controls were tested at 1 and 5 minutes, with and without virus and a virus titration was also run with each assay. The plates were reincubated at 37° C. in 5% CO 2 for the duration of the test. Acids such as sulfamic and phosphoric were also found to be virucidal. However, these acids have been found to degrade carriers such as tissue. TABLE IV__________________________________________________________________________ Concen- Surfactant One Minute Five Minutes Virucidal Efficacy tration SDS-1% TCID.sub.50 (Log.sub.10) ≈ Log Log.sub.10 (TCID.sub.50) ≈ Log Drop (% Kill)ExampleAcid % Add-On Add-On Treated Tissue vs. Control Treated Tissue vs. Control One Five__________________________________________________________________________ Min.39 Glycolic 12 -- <2.0 >3.25 <2 >2.75 >99.94 >99.8240 " 9 -- <2.0 >3.25 <2 >2.75 >99.94 >99.8241 " 2.4 -- <2.0 >3.25 <2 >2.75 >99.94 >99.8242 Salicylic 7.2 -- <2.0 >2.33 <2 >2.75 >99.5 >99.843 " 5.4 -- <2.0 >2.33 <2 >2.75 >99.5 >99.844 " 3.6 -- ≧5.17 0 4.67 0.5 0 6845 " 1.4 -- ≧5.25 0 ≧5.4 0 0 046 Succinic 9.2 -- <2.0 >3.25 <2 >2.75 >99.94 >99.8247 " 6.9 -- <2.0 >3.25 <2 >2.75 >99.94 >99.8248 " 4.6 -- <2.0 >3.0 <2 >3.17 >99.9 >99.9349 " 1.8 -- 3.9 0.8 3.9 0.4 84 6050 Malic 10.5 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.8251 " 7.9 -- NA NA <2.0 >2.75 NA >99.8252 " 5.2 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.8253 " 2.1 -- 2.38 2.87 <2.0 >2.75 99.9 >99.8254 2-Bromo-Succinic 2.0 -- 3.33 1.92 <2.0 >2.75 98.8 >99.855 " 10.2 2.0 2.5 2.5 2.5 2.67 99.7 99.856 Tartaric 11.7 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.8257 " 8.8 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.8258 " 5.9 -- <2.0 > 3.25 <2.0 >2.75 >99.94 >99.8259 " 2.3 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.82__________________________________________________________________________ Concen- One Minute Five Minutes Virucidal EfficacyEx- tration Surfactant (% Inactivation ofam- % SDS-% TCID.sub.50 (Log.sub.10) ≈ Log Log.sub.10 (TCID.sub.50) ≈ Log Drop Rhinovirus 1Aple Acid Add-On Add-On Treated Tissue vs. Control Treated Tissue vs. Control One Five__________________________________________________________________________ Min.60 Maleic 6.8 -- <2.0 >3.25 a a >99.94 a61 " 4.5 -- <2.0 >3.25 ≦2.0 ≧2.75 >99.94 ≧99.862 " 1.8 -- 2.25 ≧3.00 <2.0 >2.75 >99.9 >99.863 Acontic 9.0 -- <2.0 >3.25 <2.0 >2.40 >99.94 >99.664 " 6.8 -- ≦2.0 ≧3.25 <2.0 >2.75 ≧99.94 >99.865 " 1.8 -- 3.40 1.85 3.50 1.25 98.6 9466 Citric 10.0 -- <2.0 >3.25 <2.0 >2.75 >99.94 >99.8 (2)67 " 7.5 -- ≦2.0 >3.25 <2.0 >2.40 ≧99.94 >99.668 " 5.0 -- ≦2.0 ≧3.25 ≦2.0 >2.75 ≧99.94 >99.8 (2)69 " 2.0 -- 3.75 1.0 <2.0 >2.4 90 >99.670 Phosphoric 5.0 -- <2.0 >3.0 <2.0 >3.17 >99.9 >99.9371 " 3.8 -- ≦2.0 ≧3.0 <2.0 >3.17 ≧99.9 >99.9372 " 2.5 -- ≦2.0 ≧3.0 <2.0 >3.17 ≧99.9 >99.9373 " 1.0 -- 4.25 0.75 4.40 0.77 82 >8374 Citric/Malic 10.0/5.0 -- <2.0 >1.75 <3.0 >1.40 >98.2 >9675 " " -- <2.0 >3.0 <2.0 >3.17 >99.9 >99.9376 Wool substrate 0.6 mg/in.sup.2 4.6 0.4 NA NA 60.0 NA nw = 174.4 mg/sq. in)77 Meltblown 0.6 mg/in.sup.2 a a <3.0 1.6 NA >97.5 Polypropylene facemask BW = 52.5 mg/in.sup.2__________________________________________________________________________ NOTE: a in some cases particularly with addition of surfacant, cytopathic effects prevented useful data from being obtained. Such effects are described in Lennette, et al, Diagnostic Procedures for Viral, Rickettsial, and Chlamydial Infections, 1979, 5th Ed., p. 67. TABLE V__________________________________________________________________________ Virucidal Activity Surfactant (% Inactivation of Rhinovirus 16)ExampleAcid μMole/in.sup.2 Acid Add-On % Add-On % 1 Min. 5 Min.__________________________________________________________________________78 Sulfamic 15.6 5 -- 99 >99.99779 " 46.8 15 -- 99.997 >99.99780 " 15.6 5 -- 99 9981 " 15.6 5 SDS 2% 99 >99.99__________________________________________________________________________ Because some of the acids are soluble in water, they can be applied to many substrates from an aqueous solution with great ease either by dipping, coating, or other conventional means such as spraying or gravure printing. The composition is applied to the substrate in an amount sufficient to provide virucidal activity as defined herein. It is understood that reference to a soluble acid means that the acid is sufficiently soluble so that it will produce a virucidal affect. As will be seen from the examples above, solubilities may range from high solubility (e.g. glycolic acid used in Examples 39-41) to low solubility (e.g. salicylic acid used in Examples 11, 12, and 42-45). While the lower effective limit for the acids has not been precisely determined, in general, for a substance such as facial tissue having a basis weight in the range of 23 to 31 lbs./2880 ft. 2 (3 ply), there should be a pick-up of at least about 2 percent and preferably about 5 percent of acids such as citric on a dry basis. Other substrates such as nonwovens may be utilized as well. When mixtures of acids are employed, they may be in any proportion, but preferably the mixtures contain at least about 0.2 to 10% of each acid based on the weight of the substrate after drying. When surfactants are included, they are preferably selected from the group of anionic surfactants and included in the amount of about 0.05 to 5% based on the weight of the substrate after drying. In the application of the virucidally active organic acids defined herein in other substrates or carriers such as lotions, mouthwash, creams, sprays, polishes and the like, the preferred members being substantially non-toxic or non-irritating upon contact with human or animal tissue, the virucidally effective amount may be determined readily upon application of the procedures set for herein. For example, a log drop of 2 or more would mean that 99 percent or more of the host viruses are inactivated upon contact with the acid compositions described and claimed herein. Thus, it is apparent that there has been provided, in accordance with the invention, a virucidal product which, under conditions of normal use fully satisfies the objectives and advantages as set forth in the previous paragraphs. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and broad scope of the appended claims.

Highly effective and useful method, composition and product for annihilating harmful respiratory viruses and inhibiting the spread of diseases, including the common cold. The product includes one or more carboxylic acids such as citric, malic, succinic, benzoic and the like in an effective amount and may also include a surfactant. Embodiments include impregnated or coated substrates such as facial tissue, nonwoven materials, and the like. In one application, treated tissue, when substituted for ordinary facial tissue and used in wiping the nasal area of a person suffering from a virus-borne infection is effective in annihilating the virus on contact with the treated tissue. This, in turn, prevents the spread of the virus-related illness.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a §371 national stage entry of International Application No. PCT/EP2014/002519 filed Sep. 17, 2014, which claims priority to Italian Application No. MI2013A001532 filed Sep. 17, 2013, both of which are hereby incorporated by reference in their entireties. FIELD OF THE INVENTION The present invention is in the field of the compositions for topical use, i.e., products having a localized action, useful for the treatment of painful disorders of neurological and/or muscular origin, such as rheumatic pain, lumbago, stiff neck, trauma and bruises, and further in the field of the devices suitable to the administration thereof, particularly, medicated plasters. STATE OF THE ART The painful disorders of neurological or muscular origin are widespread. They may have a chronic (e.g., rheumatic pain), or acute (e.g., following trauma or bruises) origin. They are more or less intense disorders, generally difficult to be treated, notably in the most acute phases. The treatment of these disorders is typically based on systemically-administered anti-inflammatory drugs, or, where applicable, locally at the affected area. All these treatments often involve the use of significant doses of anti-inflammatory drugs, which may have undesired side-effects, especially in the case of a massive, prolonged use; an ongoing effort is thus present to reduce or even eliminate the recourse to such agents. The above-mentioned disorders can also be treated by a local cold application, e.g., by water, ice, or through substances generating a cold sensation, such as, for example, menthol, menthane and derivatives, etc.; the thus obtained cooling reduces the painful stimulus, or at least the perception thereof. Alternatively, also the development of a warm sensation may lead to a benefit, promoting a relaxing and decontraction of the affected muscle areas. Different devices applicable to a patient's body to generate cold or warm sensations are known. For example, packs are known, containing liquids having a high thermal capacity, which may be preventively heated or cooled, then applied onto the part of the body in need of the treatment, so as to generate the respective temperature effects. The state of the art EP 988852 shows cooling compositions based on a component selected from menthol, isopulegol, 3-methoxypropane-1,2 diol, p-menthan-3,8 diol, mixed with vanillyl butyl ether; the second component is known to cause a warm sensation; however the compositions described therein are intended only for cooling, while the heating effect is not obtained, or only occasionally in a random, non-significant statistically manner. The publication WO-A2-2010045415 describes a topical NSAID composition, in which the addition of sensate agents such as vanillyl butyl ether improves the rate of absorption of the NSAID; the document further describes the pain relief activity for the overall NSAID composition; no specific activity on pain relief is disclosed for the sensate agents themselves; no studies are present on the timing of possible warming/cooling effects. Since the warm/cold effects are clearly mutually opposite, there are difficulties in reconciling in a single device the generation of cold and heat. Moreover, even for devices capable to generate both sensations, it remains difficult to control their development in modes and times useful for an efficient treatment of painful disorders. Moreover, it remains a challenge to develop remedies topically effective on painful conditions, which avoid or strongly reduce the use of conventional anti-inflammatory agents. SUMMARY A new composition for topical application is described, characterized in that it includes, in a hydrogel base, vanillyl butyl ether and menthol. These two components, when dispersed in the hydrogel phase, at particular mutual and absolute weight ratios, allow an ordered development of cold and warm sensations, thus obtaining effects particularly useful to the treatment of painful disorders of neurological and/or muscular origin. The composition, once applied onto the skin, generates an immediate cold sensation, followed, in an ordered and statistically reproducible manner, by a warm sensation. The initial cooling effect inhibits the acute painful symptom, involving a well-being for the patient; subsequently, after the painful stimulus has been reduced/inhibited, the composition develops a pleasant warm sensation and promotes relaxation and decontraction of the affected part. Furthermore, the composition has moisturizing and soothing effects that synergize with the above-mentioned ordered cold/warm sensations, thus concurring to a curative effect, i.e. not simply symptomatic, of rheumatic and muscular pain, trauma and bruises. The composition, compatible with any administration form, is preferably and advantageously formulated as a plaster. DETAILED DESCRIPTION OF THE INVENTION The term “hydrogel” as used herein means a gelified phase obtained by hydration of one or more neutral or ionic homopolymers or copolymers, typically comprising hydrophilic groups (for example, hydroxy groups), having a structure of a tridimensional network, generally obtained by crosslinking reactions. Any dermocompatible, synthetic or natural hydrogel may be used as a base to disperse menthol and vanillyl butyl ether of the present invention. Among the synthetic hydrogels, mention may be made, for example, of hydrogels of: polyacrylates, such as polymers of hydroxyethyl methacrylate (HEMA), hydroxyethoxyethyl methacrylate (HEEMA), hydroxydiethoxyethyl methacryate (HDEEMA), methoxyethyl methacrylate (MEMA), methoxyethoxyethyl methacrylate (MEEMA), methoxydiethoxyetil methacrylate (MDEEMA) or sodium poliacrylate; polyethylene glycol and derivatives thereof, for example, polyethylene glycol acrylate, polyethylene glycol diacrylate, polyethylene glycol methacrylate, polyethylene glycol dimethacrylate; polyvinyl alcohol; polyvinylpyrrolidone, cross-linked or non-cross-linked; polyimide; polyacrylamide; polyurethane; cellulose gel or derivatives thereof, for example, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, carboxymethyl cellulose (Carmellose Sodium), etc. Among the natural hydrogels, hydrogels may be used, for example, of: hyaluronic acid, chitosan, gelatin, agar, collagen, dextran, etc. Preferred hydrogels are those based on gelatin, polyvinyl pyrrolidone, sodium polyacrylate, and carboxymethyl cellulose. The dry phase of the hydrogel, i.e., the sum of all the gelling agents used, excluding water, is present in a weight ratio comprised between 35:1 and 2:1, with respect to the sum of vanillyl butyl ether and menthol (thermal-active ingredients). The hydration rate in the mixture (weight percentage of water with respect to the total composition) of the present compositions is generally comprised between 20% and 55%, preferably between 25% and 50%, more preferably about 40%. Typically in the invention, the cooling agent menthol is present is a higher amount, compared to warming agent vanillyl butyl ether. In particular, vanillyl butyl ether and menthol are present in a relative weight ratio comprised between 1:2 and 1:25, preferably between 1:3 and 1:15. In the final hydrated composition, vanillyl butyl ether is preferably present in a weight percentage comprised between 0.01 and 1%, menthol is preferably present in a weight percentage comprised between 0.1 and 10%. Menthol and vanillyl butyl ether are used for their respective cooling and heating properties, per se known. However, the development times of the two opposite sensations plays a key role for the usefulness of the compositions for a therapeutic purpose, allowing these two components to perform an efficient curative treatment of painful disorders of neurological/muscular orgin. In particular, it has been found that these two components, when homogeneously dispersed in certain ratios within a hydrogel phase according to the invention, obtain an ordered and reproducible development of cold and warm sensations: particularly, a first immediate cold sensation is obtained which reduces/inhibits the painful, neurologic or muscular symptom in the application zone; subsequently, about 20-30 minutes after application, a warm sensation with relaxing effect ensues; the warm sensation is perceived herein in a particularly pleasant manner, since it develops when the painful symptom has already been reduced/inhibited, by virtue of the first cooling step. Typically, in the present compositions, the pain reduction/inhibition effect continues for some time also after the cold sensation has ceased, thus obtaining a wider pain reduction/inhibition time window within which the warm sensation can best carry out its relaxing effects. Without wishing to be bound by theory, it is believed that the present hydrogel base, performing a parallel tissue moisturizing action, increases the intensity/ efficiency of the cooling step, thus increasing the inhibition of the painful stimulus; the increased cooling effect avoids the development of a possible premature warm sensation, which would be less useful, being perceived still during the acute pain phase. The composition may further include the active agent Wintergreen Oil: this is an aromatic essential oil, rich in methyl salicylate, extracted from the berries of plants of the species Gaultheria . This ingredient was found by the Applicant as a highly-performing soothing and flavouring component, particularly in combination with the present hydrogel. When present, the Wintergreen oil is preferably used in a ratio comprised between 5:1 and 1:5, with respect to the sum of menthol and vanillyl butyl ether. Thanks to their enhanced therapeutic efficacy, the said menthol, vanillyl butyl ether and—when present—Wintergreen oil, are the “main” active agents of the composition, where “main” means that the composition does not include of further active principles topically active on painful disorders of neurological/muscular orgin; in particular the compostion does not contain further anti-inflammatory agents; alternatively, said further active principles may be present, although in a minoritary proportion with respect to the sum of menthol, vanillyl butyl ether and—when present—Wintergreen oil, in particular in a weight ratio lower than 1:8, or lower than 1:10; the present invention is in fact based on the key therapeutic role of the active ingredients mentioned above, which renders unnecessary the presence of additional therapeutic agents. The present composition may further comprise non-active ingredients (excipients), selected as a function of the desired application form. Among them, mention can be made of humectants, e.g., polyalcohols, such as sorbitol or mannitol, or glycols; surfactants, e.g., polysorbates; preservatives, e.g., parabens; chelating agents such as, e.g., EDTA; pH adjusters, e.g., tartaric acid; mineral fillers, e.g., kaolin; pigments, e.g., titanium dioxide; cross-linkers e.g., aluminum glycinate or the like, etc. Compositions, devised in particular but not exclusively for the implementation of medicated plasters, comprise, by weight: warm/cold component (mixture of vanillyl butyl ether+menthol, in the above indicated mutual ratios): 0.10-10% Wintergreen oil: 0-10% gelling agents (excluding water): 2-23% various excipients 30-60% water: 20-55% More preferred compositions for the use indicated above comprise, by weight: warm/cold component (mixture of vanillyl butyl ether+menthol, in the above indicated mutual ratios): 0.20-5% Wintergreen oil: 0-5% gelling agents (excluding water): 2-16% various excipients 30-60% water: 20-55% Even more preferred compositions include by weight, in addition to conventional excipients: vanillyl butyl ether: 0.01-1% menthol: 0.1-5% Wintergreen oil: 0.1%-5% gelling agents (excluding water): 2-16% water: 20-55%. Further preferred compositions include by weight, in addition to conventional excipients: vanillyl butyl ether: 0.04-0.8% menthol: 0.2-4% Wintergreen oil: 0.1-5% gelling agents (excluding water): 2-16% water: 20-55% Further compositions are illustrated in the experimental examples below. The present compositions are suitable for the topical administration to patients affected by painful disorders of nervous or muscular origin, at the affected area. The cold/warm effect, as well as the moisturizing and pain-soothing effects, are perceived on the surface of the treated skin, and they can provide a benefit to the muscular masses. Several administration modes are contemplated, comprising the application in the form of a spreadable gel, or by suitable depot systems, e.g., a medicated plaster. The medicated plaster, preferred embodiment according to the invention, has the advantage of a simple, rapid, permanent in situ, precisely pre-dosed application mode, without dispersion of the product onto skin areas adjacent to those involved by the treatment; the hydrated gel also acts as a mild adhesive: it allows the adhesion of the plaster to the skin for the time necessary to develop the cold/warm effects, and, subsequently, the gentle and pain-free release of the plaster; it is thus possible to avoid additional adhesives, glues, and solvents often used for medicated plasters, which may irritate the skin, require an excessive stretching of the skin upon their removal, and/or leave residues onto the skin that are difficult to remove. The present invention has the further advantage of making available a remedy for treating painful conditions of neurologic or muscular origin which substantially avoids the use of conventional anti-inflammatory agents like e.g. NSAID, most of which are known for their long-term toxicity. The invention is now described in non-limiting way by the following examples. EXAMPLE 1 A composition for medicated plaster produced in accordance with the invention was made as follows: STARTING COMPONENT MATERIALS PERCENTAGE VBE 0.5% Menthol 2.0% Wintergreen oil 2.0% ( Gaultheria oil) Gelatin 3.0% Povidone 1.0% Sorbitol 24.5% Kaolin 2.5% Propylene glycol 4.0% Carmellose Sodium 2.2% (CMC) Aluminum Glycinate 0.1% 1,3 Butylene glycol 8.0% Sodium polyacrylate 2.2% Purified water 48.0% Total 100.0% The composition of example 1 was applied on a suitable support (non-woven fabric) and coated with a protective polypropylene liner. The product was then applied onto the back of 6 volunteers who were asked to record, at regular intervals within a time period of 4 hours, the cold, neutral or warm sensations perceived on the treated skin area. The different sensations were classifiable on the following scale (F2)-(F1)-(0)-(C1)-(C2), where 0 represents the neutrality of the effect, F1/C1 a moderate cold/warm effect, respectively, and F2/C2 an intense cold/warm effect, respectively. The results are illustrated in table 1: TABLE 1 Time (min)/ Volunteers/ 0 5 10 20 30 60 120 180 240 S-1 0 F1 F2 F1 C1 C2 C2 C1 C1 S-2 F2 F2 F1 0 C1 C2 C2 C1 C1 S-3 F1 F1 0 C1 C2 C1 C1 C1 0 S-4 F2 F1 F1 F1 F1 C1 C2 C1 C1 S-5 0 F2 F2 F1 F1 C2 C2 C1 C1 S-6 F2 F2 F2 F1 C1 C2 C2 C1 C1 The results illustrated in table 1 show, although within the usual variability intrinsic to this kind of test, a consistent cold perception in the first step after applying the plaster, followed by a consistent warm perception in the second part of the observation period. EXAMPLE 2 A composition for a medicated plaster produced in accordance with the invention was made as follows: STARTING COMPONENT MATERIALS PERCENTAGE VBE 0.06%  Menthol 0.4% Wintergreen oil 2.0% ( Gaultheria oil) Gelatin 3.0% Povidone 1.0% Sorbitol 25.5%  Kaolin 1.5% Propylene glycol 4.0% Carmellose Sodium 1.0% (CMC) Aluminum Glycinate 0.02%  1,3 Butylene glycol 7.0% Sodium polyacrylate 10.0%  Purified water 44.52%  Total 100.0%  The composition of example 2 was applied on a suitable support (non-woven fabric) and coated with a protective polypropylene liner. The product was then applied onto the back of 6 volunteers who were asked to record, at regular intervals during a period of 4 hours, the cold, neutral or warm sensations perceived on the treated skin area. The different sensations were classifiable on the following scale (F2)-(F1)-(0)-(C1)-(C2), where 0 represents the neutrality of effect, F1/C1 a moderate cold/warm effect, respectively, and F2/C2 an intense cold/warm effect, respectively. The results are illustrated in table 2: TABLE 2 Time (min.)/ Volunteers 0 5 10 20 30 60 120 180 240 S-1 F1 F1 F2 C1 C2 C2 C1 C1 0 S-2 F2 F2 F1 0 C1 C2 C1 C1 C1 S-3 F1 F1 0 C1 C2 C1 C1 C1 C1 S-4 F2 F1 0 C1 C2 C2 C1 0 0 S-5 0 F2 F1 C2 C1 C2 C1 C1 C1 S-6 F1 F2 F1 C1 C2 C1 C1 C1 0 The results illustrated in table 2 confirm, although within the usual variability intrinsic to this kind of test, a consistent cold perception in the first step after applying the plaster, followed by a consistent warm perception in the second part of the observation period.

A composition for topical application characterized in that it includes, in a hydrogel base, vanillyl butyl ether and menthol. The composition described herein produces an ordered development of cold and warm sensations, obtaining effects that are particularly useful in the treatment of painful disorders of neurological and/or muscular origin. The composition has further moisturizing and soothing effects that concur to an effect that is also curative, i.e., not simply symptomatic, of rheumatic and muscular pain, trauma and bruises. The composition is compatible with each administration form, being preferably and advantageously formulated as a plaster.

FIELD OF THE INVENTION [0001] The present invention relates broadly to a method of cancelling crosstalk between a primary and a secondary signals contained in a frequency division multiplexed (FDM) signal, to a receiver system for a FDM signal, and to a FDM transmission link system. BACKGROUND OF THE INVENTION [0002] Cancellation of crosstalk interference between two sub-carrier FDM signals transmitted together is important in a variety of communication systems, including but not limited to fibre-optic optical communication systems, free-space optical communications systems, and non-optical communications systems such as free-space radio frequency, coaxial-cable and twisted-pair communication systems. [0003] In such systems, different motivations exist for utilising FDM signals. For example, a lower rate embedded operations channel (EOC) or optical supervisory channel (OSC) may be multiplexed with a higher rate client data stream in a single or multi-wavelength (wavelength division multiplexed, WDM) optical fibre communications system. Another example is sub-carrier FDM multiplexing of a low capacity client data stream with a high capacity data stream, such as multiplexing of legacy E1/T1 data streams with new broadband OC-n or GbE data streams in an optical communications system. [0004] In at least preferred embodiments, the present invention seeks to provide a new method of cancelling crosstalk interference between two sub-carrier FDM signals transmitted together in a communications system. SUMMARY OF THE INVENTION [0005] In accordance with a first aspect of the present invention there is provided a method of cancelling crosstalk between a primary and a secondary signals contained in a FDM signal, wherein the primary signal comprises a binary encoded signal and the secondary signal has a lower signal amplitude than the primary signal, the method comprising the steps of (a) applying 2R and/or 3R regeneration to a primary signal recovery portion of the FDM signal for obtaining an estimate of the primary signal, and (b) utilising at least a portion of the estimated primary signal to substantially remove a primary signal contribution in a secondary signal recovery portion of the FDM signal for recovering the secondary signal. [0006] In one embodiment, step (b) comprises modifying a power level of the portion of the estimated primary signal such that maximum cancellation occurs. [0007] Preferably, the secondary signal has a lower bandwidth than the first signal, and step (b) comprises bandpass filtering the secondary signal recovery portion of the FDM signal, applying substantially the same bandpass filtering to the portion of the estimated primary signal and utilising the filtered estimated primary signal portion to remove a primary signal contribution in the filtered secondary signal recovery portion of the FDM signal for recovering the secondary signal. [0008] In one embodiment, the secondary signal has a lower bandwidth than the primary signal and the method comprises the step of multiplexing the primary and secondary signals to create the FDM signal, wherein the secondary signal is multiplexed with a center frequency f C , and the method further comprises shifting f C to a higher value to reduce jitter induced by the secondary signal in the primary signal to meet a desired performance criterion. [0009] In one embodiment, the secondary signal has a ν % modulation index and the primary signal has a 100-ν % modulation index in the FDM signal, and the method further comprises utilising different values for ν for primary signals of different bit rates, wherein values higher than a lower limit value ν min for a required bandwidth of the secondary signal and a required maximum bit rate of the primary signals are used for primary signals having a bit rate lower than the maximum bit rate. The lower limit value ν min may be determined based on thermal noise only. The lower limit value may further be determined based on reduction in power levels along a transmission path of the FDM signal to the recovery point. [0010] In accordance with a second aspect of the present invention there is provided a receiver system for a FDM signal containing a primary and a secondary signals, wherein the primary signal comprises a binary encoded signal and the secondary signal has a lower signal amplitude than the primary signal, the system comprising a regeneration unit for, in use, applying 2R and/or 3R regeneration to a primary signal recovery portion of the FDM signal for obtaining an estimate of the primary signal, and a crosstalk cancellation unit arranged, in use, to utilise at least a portion of the estimated primary signal to substantially remove a primary signal contribution in a secondary signal recovery portion of the multiplexed signal for recovering the secondary signal. [0011] In one embodiment, the system further comprises an amplifier unit arranged, in use, to modify a power level of the portion of the estimated primary signal such that maximum cancellation occurs. [0012] Preferably, the secondary signal has a lower bandwidth than the first signal, and the crosstalk cancellation unit comprises a first bandpass filter structure for filtering the secondary signal recovery portion of the multiplexed signal, and a second bandpass filter structure having substantially the same filter response as the first bandpass filter structure for filtering the portion of the estimated primary signal, and is arranged such that, in use, the filtered estimated primary signal portion is utilised to remove a primary signal contribution in the filtered secondary signal recovery portion of the multiplexed signal for recovering the secondary signal. [0013] In accordance with a third aspect of the present invention, there is provided a FDM transmission link system comprising a transmitter system for a FDM signal containing a primary and a secondary signals, wherein the primary signal comprises a binary encoded signal and the secondary signal has a lower signal amplitude than the primary signal and the secondary signal has a ν % modulation index and the secondary signal has a 100-ν % modulation index in the FDM signal, and a receiver system comprising a regeneration unit for, in use, applying 2R and/or 3R regeneration to a primary signal recovery portion of the FDM signal to obtain an estimate of the primary signal and a crosstalk cancellation unit arranged, in use, to utilise at least a portion of the estimated primary signal to substantially remove a primary signal contribution in a secondary signal recovery portion of the multiplexed signal for recovering the secondary signal, and wherein the transmitter system is arranged, in use, to apply different values of ν for primary signals of different bit rates, wherein values higher than a lower limit value ν min for a required bandwidth of the secondary signal and a required maximum bit rate of the primary signals are used for primary signals having a bit rate lower than the maximum bit rate. [0014] In one embodiment, the receiver system further comprises an amplifier unit arranged, in use, to modify a power level of the portion of the estimated primary signal such that maximum cancellation occurs. [0015] Preferably, the secondary signal has a lower bandwidth than the first signal, and the crosstalk cancellation unit comprises a first bandpass filter structure for filtering the secondary signal recovery portion of the multiplexed signal, and a second bandpass filter structure having substantially the same filter response as the first bandpass filter structure for filtering the portion of the estimated primary signal, and is arranged such that, in use, the filtered estimated primary signal portion is utilised to remove a primary signal contribution in the filtered secondary signal recovery portion of the multiplexed signal for recovering the secondary signal. [0016] The lower limit value ν min may be determined based on thermal noise. The lower limit value ν min may further be determined based on reduction in power levels along a transmission path of the FDM signal to the recovery point. [0017] In one embodiment, the secondary signal has a lower bandwidth than the primary signal and the transmitter system is arranged, in use, to multiplex the primary and secondary signals to create the FDM signal, wherein the secondary signal is multiplexed with a center frequency f C , and the transmitter system is further arranged, in use, to shift f C to a higher value to reduce jitter induced by the secondary signal in the primary signal to meet a desired performance criterion. BRIEF DESCRIPTION OF THE DRAWINGS [0018] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. [0019] [0019]FIG. 1 is a schematic drawing illustrating a point-point transmission link in an optical fibre transmission network. [0020] [0020]FIG. 2 shows relative spectral power densities in an EOC+client data signal on a WDM channel of the transmission link of FIG. 1. [0021] [0021]FIG. 3 is a schematic diagram illustrating a crosstalk cancellation circuit embodying the present invention. [0022] [0022]FIG. 4 is a schematic diagram illustrating another crosstalk cancellation circuit embodying the present invention. [0023] [0023]FIG. 5 is a schematic diagram illustrating another crosstalk cancellation circuit embodying the present invention. [0024] [0024]FIG. 6 shows the relative spectral power density of an EOC signal+different client data signals for multiplexing onto one WDM channel (at any one time) embodying the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS [0025] [0025]FIG. 1 illustrates a point-point uni-directional transmission link in an optical fibre transmission network. Another of these uni-directional links transmitting EOC and High Speed Data in the opposite direction would normally be added to form a bi-directional point-point link. Multiple such bi-directional links may be concatenated (daisy chained) to form a regenerative (3R—Reamplify, Reshape, Retime) bus, ring or mesh network. Alternatively, the transmission link can be bi-directional on a single fibre connection, with different wavelength channels transmitting in opposite directions along the transmission link. [0026] [0026]FIG. 1 illustrates an example of a multi-wavelength WDM uni-directional transmission link. Only one of the wavelengths (eg, λ 1 ) is used to multiplex the EOC symbol stream with a High Speed (Client) Data symbol stream (numeral 12 ). The other WDM channels e.g. 14 , 16 can carry data in any format, protocol or rate. Since they are optically (WDM) multiplexed, they do not interfere by any significant amount with the two data streams sent on the EOC/Data Channel 12 . [0027] For the EOC/Data channel 12 , the Client Data stream is binary coded using a suitable coding format so that it can be transmitted through an AC-coupled network. Suitable line codes have the characteristics that: there are equal numbers of 1-symbols and 0-symbols in the data stream when averaged over a sufficiently long sequence of bits; and there is a sufficient density of transitions between different symbols (1& 0 in this case) so that a Clock/Data Recovery (CDR) device can recover the clock and the binary Data stream can be (3R) regenerated by the receiver unit 18 such that the required Bit Error Rate (BER) for the link is achieved. The binary coding process may be implemented by external client equipment (not shown) or via tributary interface cards (not shown) at the ingress to the optical fibre transmission network. [0028] [0028]FIG. 1 shows the EOC symbols being multiplexed with the Client Data at the transmitter 20 . The multiplexing method involves a process of linear addition (numeral 22 ) of laser drive currents proportionally attributed to each signal. The total laser drive current has lower and upper limits set respectively by its threshold current and its maximum recommended current or power. As a result of these limits, it is evident that the presence of the EOC signal (with ν % laser current modulation index) effectively reduces the maximum current and associated transmit optical power attributable to the Client Data signal (to a value 100-ν %). This has the effect of reducing the optical link margin for each signal (compared to the case where each signal would have 100% modulation index) and thus reduces the maximum transmission distance for each signal. [0029] [0029]FIG. 1 also shows a means of demultiplexing the EOC and High Speed Data signals from the EOC/Data channel 12 . This comprises a single (linear) optical receiver 24 and an electrical tap (or splitter) 26 to direct the signals to two separate noise filters and signal detectors 18 , 28 . [0030] If a passive electrical tap 26 is used which splits the signal power between EOC and Data detectors 28 , 18 , there will be some reduction in each of the signal levels presented to each detector, which will generally reduce the sensitivity of the each detector by η % in the case of the Client Data channel and 100-η % in the case of the EOC channel (where η % is the passive electrical tap ratio for the EOC detector 28 ). [0031] Other passive and active electrical tap arrangements are possible which forward the combined EOC/Data signal to both detectors 18 , 28 without any significant reduction in signal level or Signal to Noise Ratio (SNR) presented to each detector 18 , 28 . [0032] The two filters and detectors 18 , 28 are optimized for each of the EOC and Client Data signals separately. Since the EOC bandwidth is generally much less than the Client Data bandwidth, the EOC noise filter bandwidth can be commensurately smaller than the Client Data noise filter bandwidth. Additionally, the filter response (amplitude-phase-frequency characteristic) will be optimized for the signal coding/modulation format. [0033] For binary-coded signals such as the Client Data signal (and optionally, the EOC signal), a raised-cosine filter response is often used to minimize inter-symbol interference between symbols in the same data stream. Such a filter is generally set to have a bandwidth equal to 0.7 to 0.8 of the maximum Client Data rate to be transmitted at any time on that wavelength channel 12 . [0034] For a WDM system that is capable of transmitting at any time, any one of a range of protocols and rates, then generally, the Client Data receiver filter bandwidth and response will be optimized for the worst-case protocol and rate. In many WDM applications, this would be the SONET/SDH 2.488 Gbit/s rate for example. [0035] It is feasible to program the Client Data receiver filter bandwidth and response to be optimal for each protocol transmitted. This in theory would extend the maximum transmission distance for lower-rate protocols. However, for WDM networks, this often provides little benefit if one of the other WDM channels is carrying a SONET/SDH 2.488 Gbit/s stream which will limit the maximum transmission distance—irrespective of the filter-optimisation for any one or more of the other channels. [0036] As shown in FIG. 1 the Client Data signal is further processed (detected) in the filter and detector 18 to reduce the effects of highly variable signal attenuation, random (thermal) noise, systematic (pattern-dependent) noise and crosstalk (due to the EOC signal for example). This processing includes a binary detector (2R regenerator) (not shown) which regenerates the symbol shape (rise/fall time and binary signal levels) and a Clock /Data Recovery (CDR) device (3R regenerator) (not shown) which recovers the clock associated with the Client Data protocol and uses this to retime the Client Data and reduce jitter (symbol pulse width distortion). The purpose of this processing is to produce a 3R-regenerated Client Data stream at numeral 30 , which meets the BER specification. [0037] As shown in FIG. 1, the EOC filter and detector 28 will also be optimized to meet the BER requirements of the EOC channel. The detection process will differ in that the modulation format may be different (eg, FSK, PSK or QAM modulated rather than binary encoded), the symbol rate will be significantly less and the level of crosstalk from the Client Data for example may be greater. The latter will depend on the Client Data protocol and rate. An example is a 51.84 Mbit/s SONET OC1 Client Data protocol 202 b, which as shown in FIG. 2, adds significant crosstalk (overlap region 212 b ) to a 1 Mbit/s EOC channel 200 due to significant low frequency spectral content in the OC1 stream. This low frequency content results from long strings (eg, up to 72) of Consecutive Identical Digits (CID))—a consequence of the use of a simple scrambler (as per the SONET specification) to encode the binary data stream. [0038] [0038]FIG. 2 also highlights the difference in crosstalk that can occur between the two signals. Comparing relative power levels in the crosstalk (overlap) region 212 , the SNR due to EOC crosstalk onto the OC1 Client Data signal is shown to be significantly greater than the SNR due to OC1 crosstalk onto the EOC channel. These crosstalk ratios can be adjusted by changing the modulation index (ν) at the transmitter 20 (FIG. 1). The value of ν used in FIG. 2 was 20%. Note that changing the electrical or optical tap-ratio (η) at the receiver does not affect the crosstalk. It can however, affect the receiver sensitivity and associated maximum transmission distance due to signal level, thermal noise, bandwidth and BER tradeoffs. [0039] It is evident from the above description that it is desirable to avoid, cancel or eliminate the crosstalk between the client data and the EOC data signals for satisfactory recovery of each of those signals from the multiplexed channel signal. Most signal correlation techniques aim to extract a known signal from unknown noise. To this end, elaborate and/or low throughput encoding techniques are used. A preferred embodiment of the present invention instead applies a noise cancellation technique to remove from a EOC signal the residual Client Data noise that is within the EOC passband. [0040] The following process summarises this cancellation technique in a preferred embodiment: [0041] (a) Apply 2R and/or 3R correlation techniques with low modulation index to recover the binary coded Client Data signal with minimum error; [0042] (b) Pass the relatively “clean” Client Data signal through a filter having the same bandwidth and response as the EOC path through which the EOC+Client Data signal passes; [0043] (c) Adjust the level of the filtered Client Data signal so that when subtracted from the EOC+Client Data signal (having passed the EOC path), maximum cancellation of the Client Data signal contribution occurs. This adjustment process may simply involve a knowledge of the optical signal level at the 1R receiver input and a knowledge of the gain/losses along the EOC+Client Data path (taking the EOC receiver AGC characteristic into account if necessary). [0044] (d) Recover the EOC signal (with Client Data substantially cancelled) using an appropriate EOC signal detector (correlator). [0045] (e) Disable the cancellation path if Loss of Client Data Signal is detected. [0046] [0046]FIG. 3 shows a crosstalk cancellation circuit 1 10 embodying the present invention. In the circuit 110 , an optical tap element 112 is utilised to “split” an incoming FDM client data+EOC signal (numeral 114 ) into a first portion directed towards a client data recovery segment 116 of the circuit 110 and a second portion directed towards an EOC recovery segment 118 of the circuit 110 . [0047] Within the client data recovery segment 116 , an optical receiver unit 120 it is utilised for 1R regeneration, followed by (AC coupled) a binary detector unit 122 for 2R regeneration. This in turn is followed (AC coupled) by a clock/data retiming (CDR) unit 124 for 3R regeneration for ultimate recovery of the (regenerated) client data signal V S3 . [0048] In the EOC recovery segment 118 , an optical receiver unit 126 is utilised for 1R regeneration, followed by an additional bandpass filter PBF 3 . [0049] As illustrated in the inlets (a),(b),(c) in FIG. 3, the 2R regenerated Client Data signal V S2 is a close estimate of the original Client Data signal with minimum residual thermal and EOC crosstalk noise. Furthermore, for lower bit rate protocols (such as OC3) which cause the greatest crosstalk onto the EOC channel, the thermal and EOC induced jitter on the Client Data signal V S2 is fortuitously smaller. Hence the 2R regenerated lower bit-rate Client Data protocols will be “cleaner” (less noisy) and will be more effective in cancelling the Client Data noise on the EOC signal. [0050] Signal V S2 is fed into a cancellation path 128 shown in FIG. 3, in which Bandpass Filter BPF 4 is designed to have the same filter response as the concatenated filters BPF 2 and BPF 3 through which the EOC+filtered Client Data signals pass in the segment 118 . The cancellation path 118 also includes an adjustable level control unit 130 with absolute gain/attenuation factor K (K≧0). The value “K” is adjusted by control input (Cntrl-1) based on either the EOC or Client Data 1R optical receiver input signal amplitude (A 0 ). The filtered cancellation signal V S6 is inverted (indicated by Gain=−K) so that when added to the EOC+filtered Client Data signal V S5 at adder unit 132 , the net result will be: V S7 =EOC+ε where ε is a small cancellation error. [0051] Sources of cancellation error ε include: [0052] (1) Filtered Client Data signal shape mismatch—due to variations in filter response; [0053] (2) Residual jitter on the filtered Client data signal; [0054] (3) Filtered Client Data signal amplitude mismatch—due to variations in receiver signal level measurement, gain/attenuation stage (−K) and gain/loss variations in the EOC receiver path; [0055] (4) Delay mismatch between the Client Data receiver+regeneration+cancellation paths and the EOC receiver path for the filtered Client Data signals. [0056] Cancellation errors (1) and (3) can be compensated for using tighter component specifications and production techniques. To a large extent, the same applies to 4) for the 2R regeneration options in the example embodiment of FIG. 1. In these cases, the Client Data path delay (t pd ) due to the 2R Binary Detector is relatively small (≈100 ps) for a broadband (eg, OC-48) capable system. The delays introduced by narrowband filters BPF 2 , BPF 3 , BPF 4 , BPF 5 & BPF 6 in FIG. 3 will dominate over the broadband Binary Detector delay. [0057] Cancellation error (2) (residual jitter) will be negligible for high enough SNR and low EOC modulation index v and/or for low bit-rate protocols such as STM1/OC3. For the case of the higher bit-rate protocols, such as STM16/OC48, the modulation index can be reduced which will compensate to a limited extent for the increased relative jitter due to the shorter bit-period. As shown in FIG. 6, the Client Data crosstalk onto the EOC signal at the OC48 rate is found to be about {fraction (1/16)} th of the crosstalk at the OC3 rate. Consequently, a slightly increased cancellation error (2) due to jitter at the higher bit rates is less significant. [0058] [0058]FIG. 4 shows an alternative crosstalk cancellation circuit 210 embodying the present invention. In that embodiment, an electrical tap 212 is utilised to “split” an incoming FDM multiplexed client data+EOC signal in the electrical domain at the output of an optical receiver unit 226 , utilised for 1R regeneration of the incoming optical FDM signal at numeral 214 . [0059] As illustrated in the inlets (a), (b), (c) in FIG. 4, the 2R regenerated client signal V S2 is a close estimate of the original client data signal with minimal residual thermal and EOC crosstalk noise. Signal V S2 is fed into a cancellation path 228 shown in FIG. 4, in which bandpass filter BPF 6 is designed to have the same filter response as the bandpass filter BPF 5 in the EOC recovery segment 218 . [0060] The cancellation path 228 also includes an adjustable level unit 230 with absolute gain/attenuation factor K (K≧0). The value “K” is adjusted by control input 232 based on the EOC plus client data 1 R optical receiver input amplitude (A 0 ). The filter cancellation signal V S6 is inverted (indicated by −K) so that when added to the EOC+filtered client data signal V S5 at add unit 234 the net result will be: V S7 =EOC+ε, where ε is a small cancellation error. [0061] [0061]FIG. 5 shows another circuit 300 embodying the present invention for further reducing cancellation error (2) above—especially at the higher Client Data bit rates—by using the 3R regenerated signal V S3 as the source of Client Data in the cancellation path 328 . This figure is generic to both optical and electrical tap options (compare FIGS. 3 and 4). A disadvantage of using the 3R regenerated Client Data signal for the cancellation method is the bit-rate dependent delay introduced by the CDR unit 302 . A delay compensation unit 304 is used as shown in FIG. 5 to address that disadvantage. The delay “D” must be programmable to equal typically half a bit-period. Furthermore, any mismatch in the compensation delay “D” will increase the cancellation error (4) above. Again, BPF Y and bandpass filter BPF X have substantially the same filter response. [0062] As shown in FIGS. 3 and 4, there is a Control Input “Cntrl-2” to the 2R regenerator. In the case of FIG. 5, Cntrl-3 may be used instead. These Control Inputs are used to force the Client Data signal V S2 /V S3 and the filtered Client Data signal V S6 to zero when Loss of Client Data Signal is detected, so that the cancellation process is effectively disabled as per Process step (e) of the cancellation technique embodying the present invention outlined above. [0063] A person skilled in the art will appreciate that there are several other means of disabling the cancellation process, such as applying a disable control line to the gain/attenuation stage in the cancellation path so that K=0 when disabled. [0064] There are several means of detecting Loss of Client Data Signal (eg, insufficient power in the Client Data passband measured with a filter that excludes the EOC passband; Loss of CDR Lock, Client Data BER Performance Monitoring, etc). [0065] Process step (e) is preferable to prevent the EOC signal from cancelling itself out in cases where the Client Data signal disappears for some reason (eg, not yet provisioned for that wavelength or has failed at the source). It is important that the EOC channel continue to operate during either the presence or absence of a Client Data signal on the EOC/Data channel. [0066] Thermal noise analysis has shown that an EOC modulation index ν as low as 1% is possible for a 1 Mbit/s binary encoded EOC signal in a broadband OC48 system. [0067] Using a Client Data crosstalk cancellation method embodying the present invention, it is now feasible to design a Subcarrier FDM multiplexed EOC+Client Data transmission system for which the laser current modulation index ν (and receiver tap ratio η if applicable) are optimized in terms of the thermal noise performance of the system. It is no longer necessary to increase the modulation index ν to reach a compromise between EOC crosstalk onto Client Data and Client Data Crosstalk onto EOC. [0068] Subject to the practical limitations of cancellation error compensation (refer (1) to (4) above, it is now possible to design an EOC/Data channel with a very low modulation index (as low as 1% for the examples given here). [0069] Additionally, when used in conjunction with the Client Data encoding methods described in U.S. patent application Ser. No. 10/145590 entitled “Jitter control in optical network”, filed on May 13, 2002 assigned to the assignee of the present application, and U.S. patent application Ser. No. 10/160987 entitled “Optical network management”, filed on May 31, 2002, and assigned to the assignee of the present application, the present invention can cause a shift downward of the threshold level that determines when a Client Data signal should be encoded or not. Alternatively, for the same threshold level, the present invention can permit higher data throughputs for the EOC channel (>1 Mbit/s for example). [0070] It is noted that, the modulation/coding format of the EOC channel has not been limited in any way (although binary coded examples have been used). The present invention does not restrict the EOC modulation or coding format, symbol rate or sub-carrier frequency passband in which the EOC channel resides. [0071] One of the performance improvement benefits which can be provided is reduced EOC induced pulse-width jitter in the Client Data at high bit rates. This is achieved where the modulation index ν can be reduced to a very small value. The extent to which the modulation index ν can be reduced will depend on the practical limits to the cancellation error compensation (for cancellation errors (1) to (4) above). [0072] The higher EOC induced pulse-width jitter for the STM16/OC48 protocol and bit-rate results from the EOC frequency passband falling within the section of the CDR loop filter jitter transfer function where there is either no jitter attenuation, or worse—there is jitter gain. [0073] The present invention now offers the opportunity to shift the center-frequency of the EOC passband to a higher frequency where any resultant jitter will certainly be attenuated by the CDR (ie, above 2 MHz in the STM16/OC48 case). [0074] [0074]FIG. 6 shows how the EOC passband 201 can be shifted to a higher center frequency ƒ C with no increase in crosstalk from the Client Data (e.g. 202 , 204 , 206 , 208 or 210 ) onto the EOC. Note that FIG. 6 does not show the reduced modulation index ν that is now possible. With reduced modulation index v and crosstalk cancellation, it will be possible to further reduce the pulse-width jitter of the Client Data signal. [0075] Another advantage of this ability to frequency shift the EOC signal spectrum is that for the electrical tap option (compare e.g. FIG. 3), the Client Data optical receiver filter BPF 1 no longer needs to extend down to very low frequencies. The lowest frequency that it will need to pass will be determined by the lowest bit-rate protocol with the longest string of Consecutive Identical Digits (CID). It will not be determined by the lowest frequencies that the EOC channel needs to pass. [0076] The present invention can provide the following example optimization and improvement methods and the following example procedure for managing them: [0077] i) For the required EOC channel bandwidth and the required maximum Client Data bit rate, determine the smallest value of EOC modulation index ν min that is possible based on a thermal noise analysis alone (ie, no crosstalk). [0078] ii) Apply the Client Data crosstalk cancellation method with a value of ν that is as small as possible (but no smaller than ν min ) within the practical limits of the cancellation errors attributable to imperfect filter designs, imperfect amplitude matching, imperfect delay matching and imperfect jitter removal. [0079] iii) Within the bounds set by i), ii) above, apply a variable EOC modulation index ν, which provides maximum performance for the Client Data bit rate being transmitted. For example, depending on the receiver design, slightly higher values of ν can be used for the lower Client Data bit rates, when these bit rates have slightly better receiver sensitivity. [0080] iv) If the total input power to the receiver is to be split such that the signals sent to the EOC and Client Data receivers/filters/detectors are reduced in level (eg, due to a optical tap with tap ratio η), then this signal level reduction must be taken into account when determining the EOC modulation index ν. [0081] If the above methods result in acceptable performance for the EOC and Client Data channels, then nothing more needs to be done. [0082] v) If the performance is not acceptable and there is excessive EOC-induced pulse-width jitter, then frequency-shift the EOC band to a higher center frequency ƒ C to reduce the EOC-induced jitter on the Client Data signal. [0083] vi) If the performance is still not acceptable, then identify a threshold below which the Client Data signals must be encoded to reduce the crosstalk with the EOC channel. [0084] There is nothing about the present invention that restricts the lower-bandwidth “secondary” channel to be used for EOC applications only. The secondary channel can transport data in any format for any low-capacity (narrowband) application. In fact, the present invention permits greater bandwidth to be allocated to the secondary channel than is normally the case, since the secondary channel modulation index v can be made very small (so as not to interfere with the primary broadband data channel) and yet still achieve reasonable performance in the presence of broadband data. [0085] Given this, other applications of the present invention include, but are not limited to: [0086] 1) Low incremental-cost multiplexing of legacy narrowband services (such as 2.048 Mbit/s E1 or 1.544 Mbit/s T1) and new broadband services (such as OC1-OC48, Gigabit Ethernet and Fibre Channel) onto the same wavelength channel (in a single wavelength optical fibre link or network) or on multiple channels (in a WDM optical fibre link or network). The new broadband services are transported through one or more broadband channels (one per wavelength) each of which supports multiple client protocols and bit rates. [0087] 2) As for 1), but for other optical transmission media other than fibre-optic. Free-space optical communications is an example. [0088] 3) As for 1), but for other transmission media, other than optical, such as microwave radio, coaxial cable and twisted-pair. In these applications, simply equate wavelength channel to frequency channel. [0089] The present invention can enable more degrees of freedom in terms of optimizing the performance of a two-channel sub-carrier FDM system. [0090] The present invention can avoid/reduce, crosstalk tradeoffs from primary to secondary and secondary to primary signals which constrain the modulation index and/or require the use of a lower throughput secondary channel and/or require the use of power-consuming encoding of the primary signal for protocols and bit-rates below some threshold. [0091] The present invention has wide application. Whilst it was designed to solve an EOC/Data crosstalk problem, it can also be applied to many other narrowband/broadband signal multiplexing applications and transmission media, such as E1/T1 with OC-n, Gigabit Ethernet and Fibre Channel for example. [0092] For example, it could be used to upgrade existing narrowband Digital Loop Carrier (DLC) networks which multiplex narrowband (POTS) telephony channels into E1/T1 streams with additional capacity to support new broadband services such as multiple ADSL channels multiplexed into a single ATM/OC-n stream (per wavelength or frequency carrier) or multiple VDSL channels multiplexed into a single Gigabit Ethernet stream (per wavelength or frequency carrier). [0093] It will be appreciated by the person skilled in the art that numerous modifications and/or variations may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive. [0094] In the claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication the word “comprising” is used in the sense of “including”, i.e. the features specified may be associated with further features in various embodiments of the invention.

A method of cancelling crosstalk between a primary and a secondary signals contained in a FDM signal, wherein the primary signal comprises a binary encoded signal and the secondary signal has a lower signal amplitude than the primary signal, the method comprising the steps of (a) applying 2R and/or 3R regeneration to a primary signal recovery portion of the FDM signal for obtaining an estimate of the primary signal, and (b) utilising at least a portion of the estimated primary signal to substantially remove a primary signal contribution in a secondary signal recovery portion of the FDM signal for recovering the secondary signal.

[0001] This application is entitled to the benefit of Provisional Patent Application Serial No. 60/240,495 filed Oct. 13, 2000. BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] The present invention relates generally to digital image processing systems. More particularly the invention describes techniques that greatly improve the performance of rendering image data. More particularly, techniques are described that take advantage of resolution-independent characteristics, even for operations that are traditionally not considered to be resolution-independent. More specifically, certain techniques are applied to simulate resolution-independent behavior (called pseudo-resolution-independent) when an image operation is applied at any resolution. [0004] These techniques can greatly improve the performance of rendering systems in computer applications, such as those executing on personal computers, digital imaging consumer appliance devices, and when viewing and manipulating photos over a network environment (in the form of client-side or the server-side executable code on either a physically wired or wireless medium). [0005] Most image operations fall into two categories: those that generate the same result, regardless of the resolution of the image (i.e. resolution-independent) and those that generate significantly different visible results for different resolutions of image data (i.e. resolution-dependent). Rotation, for example, is invariant across all resolutions and is resolution-independent However, a special effects image processing operation such as a Fresco paint effect varies widely across different resolutions and is resolution-dependent. [0006] If only resolution-independent operations are supported, a significant performance improvement is achieved since rendering can be performed on the lower-resolution image data that is needed for on-screen viewing of the output. Because, in general, the resolution of the display is usually much less than that of most other output devices, such as a high-resolution printer. [0007] If all, or at least the majority, of the resolution-dependent image operations behave in such a way that they simulate resolution-independent behavior, most of the benefits of resolution-independence are still realized. While it may not be possible to support a continuous range of resolutions in a resolution-independent manner, certain assumptions and constraints are made that allows resolution-independence to be approximated, thus creating a new class of pseudo-resolution-independent image operations. In the preferred embodiment, all operations are either resolution-independent or pseudo-resolution-independent. [0008] One of the objects of this invention is the ability to efficiently process image data at lower-resolutions, but then also be able to obtain consistent results across all resolutions. This is particularly important when viewing and processing images in on-screen display devices, since in general these devices are much lower resolution than the resolution of the image data. Moreover, this invention provides this efficiency without sacrificing consistent results across all resolution, something most applications today cannot correctly support. [0009] Another object of the invention is to be able to process and transmit must less image data than would otherwise be necessary, which is essential in a network-connected environment. If the client must download image data, where it is processed locally (on the client), it is of much benefit to only require that a small amount of data be downloaded. Today, the original resolution image must be transferred to the local client so that the image operations can achieve consistent results even though a small screen resolution view (less than the original resolution image) is needed. Even when the operations are performed on the server, the ability to perform the image operations at the screen resolution of the image data significantly reduces the processing and memory requirements of the server, thus permitting many more transactions to be performed in the same amount of time. [0010] An equally important benefit is that these techniques allow digital imaging operations to be performed on low-cost consumer electronics imaging devices that have low-processing power and little memory. Up until now, this has been difficult to achieve due to the system constraints. [0011] 2. Description of Relevant Art [0012] Traditional image processing applications, such as Adobe Photoshop™, assume that the best way to get consistent results for all image processing operations is to perform the operations at the original image resolution, regardless of the targeted output device's resolution (whether it is higher or lower than the original image resolution). This guarantees consistent results, regardless if the image is viewed on a low-resolution video display or a high-resolution printer. Traditional image processing applications usually support one of two approaches listed below: [0013] The first approach, shown in FIG. 1 a , accumulates the sequence of image operations that are applied and re-renders each operation when an updated output image is requested from the output device. This involves the complete reprocessing of all image operations at the image's original resolution. This can be a very slow process since each operation is reapplied at the original image resolution. This gives the user the flexibility to have unlimited undo capabilities since each operation is stored in a list of operations. [0014] Referring now to FIG. 1 a , process 100 is a flowchart that details the processing of a digital image using a traditional image-editing model. Process 100 begins at 102 when a particular digital image is opened by the application at the resolution of the image. There is no resampling/rescaling that occurs. At 104 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, control is pass to 108 . Otherwise, at 106 the image operation is performed on the original image resolution data, then control is passed back to 104 , where it is determined if there are additional image operations to be processed. It should be noted, in this model successive image operation are applied on top of (or accumulated on) the previous image operations that have been applied to the image. [0015] At 108 , the desired output resolution is determined. At 110 , if the original image resolution does not match the desired output resolution, then at 112 the image is copied into a temporary buffer and is resized to match the desired output resolution and then control is passed to 114 . Otherwise, control is passed directly to 114 where the image is sent to the output device. When the output device selected is a display, the output resolution may vary depending if the image is enlarged or reduced (zoomed in/out) on the display. However, the key observation is that the image operations are generally applied to the original image resolution data, and after all operations are applied, the image is resized to match the resolution of the output device. [0016] The second approach, shown in FIG. 1 b , performs each operation on the image data at the original image resolution, but in an intermediate working or cached buffer. This working buffer contains the entire image at the original image resolution. As each new operation is applied, it is performed directly on the working buffer. When a desired output resolution image is to be generated, the working buffer is resampled to match the desired output resolution. Clearly, the benefit is that each operation is normally applied once in the working buffer and does not need to be reprocessed when a new output resolution is requested. The disadvantage with this approach is that while unlimited undo/redo operations are possible, it is more difficult to support such a feature since the entire list of image operations are not normally re-rendered when an updated output image is requested. [0017] Referring now to FIG. 1 b , a process 150 is a flowchart that details the processing of a digital image using this model. The process 150 begins at 152 when a particular digital image is opened by the application. At 154 , the digital image is copied into the working buffer, at the same resolution as the original. At 156 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, control is pass to 160 . Otherwise, at 158 the image operation is performed on the working buffer (with the accumulated operations), then control is passed back to 156 , where it is determined if there are additional image operations to be processed. [0018] At 160 , the desired output resolution is determined. At 162 , if the resolution of the working buffer (which is the resolution of the original image) does not match the desired output resolution, then at 164 the working image is copied into a temporary buffer and is resized to match the desired output resolution. In either case, at 166 the resized image from the temporary buffer is displayed on the output device. The process then waits at 168 until either a request to re-render the image or a user request for a new image operation is applied. At 170 , it is determined if the program should terminate, if so the appropriate steps are taken and the process stops. Otherwise, control is pass back to 156 to process the request. In this way, the entire list of image operations need not be reapplied to the working image buffer. [0019] The approach taken by Adobe Photoshop™ is a combination of the two approaches. In this case, an intermediate working buffer (s) is used, but is considered a cache that can be flushed if the user performs an undo operation. The working buffer can be discarded and be regenerated based on the updated list of image operations. Alternatively, the working buffer can be reverted to a previous cached copy of the working buffer. Taken to an extreme, all intermediate operations can be cached, simulating the effect of infinite undo/redo operations. This is at the expense of using a significant amount of memory and/or disk space [0020] While each of these approaches has the benefit of providing consistent results across all resolutions, it is generally slower since the image processing operation(s) must be performed on all the pixels at the original image resolution. Although using intermediate working buffer caches minimizes the need to reprocess all image operations each time a new render resolution is requested, the image operation(s) must still be performed on the original resolution the first time. Even on the fastest processors today, this can still be a time consuming operation. It should be noted that variants of this model are possible when certain common resolution-independent operations are performed, such as rotate or color adjustment filters. In these situations, it is common to resize/resample the working buffer to a much lower resolution, such as the screen resolution, where a preview of the operation can be shown. Using this technique, real-time manipulation is feasible for the limited set of resolution-independent operations. Once the user is satisfied with the results, the operation is then applied to the original resolution working image buffer. [0021] While this does mitigate some of the disadvantages described above, only a small subset of image operations conform to this resolution-independent behavior or can support the desired real-time manipulation functionality. [0022] More recently, new technology is available that allows efficient image rendering when all image operations are performed in a resolution-independent manner. An imaging application that supports FlashPix™ technology, developed by a consortium of companies comprising of the Digital Imaging Group (DIG), can display and manipulate on-screen images at a lower-resolution in a consistent manner, but retains the ability to process higher-resolution image data. [0023] FlashPix™ technology defines a limited set of image operations including: rotation, translation, cropping, color twist, blur/sharpen adjustment, and brightness/contrast adjustment. Each of these operations is defined such that they can be performed at specific “powers of two” resolutions as defined by the FlashPix™ standard, but provides consistent results across all these resolutions. [0024] Referring now to FIG. 2, process 200 is a flowchart that details the processing of a digital image using the FlashPix™ imaging model. The process 200 begins at 202 when a particular digital image is opened by the application. At 204 , the desired output resolution is determined. At 205 , it is determined if the output resolution and the original image resolution are the same. If they are not, at 206 , the image is resized to match the resolution of the output device. In either case, at 208 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, control is pass to 212 . Otherwise, at 210 the image operation is performed on the image data resized in step 206 . Control is then passed back to 208 , where it is determined if there is additional image operations to be performed. [0025] At 212 , the processed image is sent to the output display device. Since at 204 the output resolution was already determined and all processing was performed on the targeted output resolution, no additional resampling of the image is needed. It should be noted, a similar working buffer cache could also be employed in the FlashPix™ rendering model, as described in section 2.1 above. [0026] The FlashPix™ imaging model provides the benefit of quick and efficient processing of the image operations when performed on lower-resolution image data. This provides for real-time manipulation and rendering on a low-resolution output display device. While this is clearly beneficial, only a small set of resolution-independent operations are actually supported. More particularly, it would be impossible to support any operation that is resolution-dependent, or even pseudo-resolution-independent since the architecture does not permit for such provisions as described in this paper. It is also noted that FlashPix™ only supports specific “powers of two” resolutions, and not a continuous range of resolutions as provided by this invention. [0027] A completely opposite and simplistic approach is also used in which the resolution requirements of the image operations are ignored and each operation is processed at some fixed resolution. This resolution usually does not match the original image resolution, nor does it provide for consistent behavior if the operations were applied at different resolutions. For the cases when the image operations are resolution-independent, as for those supported by Flashpix™, this model works and provides consistent results. However, for those cases where the image operations are not resolution-independent, more inconsistent results are seen. The degree of inconsistency is a function of the specific image operation. [0028] For example, when applying a resolution-dependent blur operation, such as a low-pass 5×5 kernel, the amount of blur becomes less pronounced as the resolution (and image size) increases. This may not be too objectionable since in both cases, the image appears with some degree of blurriness. However, for a “ripple” effect, in which a simulation of a ripple of a stone dropping into a lake is rendered onto an image, the actual number of concentric ripples and appearance varies depending on the resolution and the exact characteristics of the algorithm (see sample output for the ripple operation in section 5.2 and 5.3). [0029] Referring now to FIG. 3, process 300 is a flowchart that details the processing of a digital image using this approach. The process 300 begins at 302 when a particular digital image is opened by the application. At 304 , the desired output resolution is determined. At 305 , it is determined if the output resolution and the original image resolution are the same. If they are not, at 306 , the image is resized to match the resolution of the output device. In either case, at 308 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, control is pass to 312 . Otherwise, at 310 the image operation is performed on the image data resized in step 306 . This occurs even though the image operation may require the original image resolution data; therefore, proper results might not be obtained. Control is then passed back to 308 , where it is determined if additional image operations are to be performed. [0030] At 312 , the processed image is sent to the output display device. Since at 304 the output resolution was already determined and all processing was performed on the targeted output resolution, no additional resampling of the image is needed. It should be noted, a similar working buffer cache could also be employed in this rendering model, as described in section 2.1. [0031] It is common for this type of approach to be taken on Web sites that support image processing operations, but where the primary output target is a low-resolution output display device. In general, after the image operation is applied to the image (at low-resolution), the results are commonly e-mailed to a recipient. The recipient then views the low-resolution result (already rasterized) on their low-resolution output display device. [0032] For cases when the operation is reapplied to the original resolution image data for printing, such as through an on-line print fulfillment service, the situation is even more problematic. The user may preview the output via a low-resolution rendered image on-screen. In this case, the output viewed on the display may not match the final printed output that is ordered. [0033] Even if 80% of the time this discrepancy is not detected, for those that do notice the difference, they may request a refund of a printed output. This situation is very costly and is clearly not an acceptable solution. This invention creates a more desirable result since consistency is achieved across all resolutions for all operations, thus improving customer satisfaction. [0034] More importantly, a photo service that takes the “ignore it” approach will most likely limit the supported image operations to minimize this problem. What is desired is the ability to offer a larger range of image operations, assuming these image operations are either resolution-independent or are structured that they can take advantage of resolution independent characteristics (i.e. pseudo-resolution-independent). SUMMARY OF THE INVENTION [0035] In summary, the present invention consists of a method for applying normally resolution-dependent image effects in such a manner that the effects have substantially the same appearance regardless of the final resolution of the image. This allows the effects to be applied to any image resolution with the confidence that regardless of the later resolution rendered, the resulting effect will have the same appearance as it had when it was applied to the original resolution. By determining which particular effect parameters are resolution dependent and then modifying those parameters with the modification values being predicated on the final image resolution being rendered, it is possible to convert resolution-dependent parameters into substantially resolution-independent parameters. BRIEF DESCRIPTION OF THE DRAWINGS [0036] The invention, together with further advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which: [0037] [0037]FIGS. 1 a and 1 b show a flowchart that details two traditional methods of image processing. [0038] [0038]FIG. 2 shows how FlashPix™ processes a digital image. [0039] [0039]FIG. 3 shows how a digital image may be processed at a fixed resolution. [0040] [0040]FIG. 4 and 4 a are flowcharts that show how the present invention renders a resolution dependent image. [0041] [0041]FIG. 5 shows the details for selecting the best resolution for a series of image operations that are to be processed. [0042] [0042]FIG. 6 shows an implementation for handling the “DoAnalyze” phase of the present invention. [0043] [0043]FIG. 7 shows the process for selecting the best resolution for the image to be processed based on the original resolution and the current output resolution. [0044] [0044]FIG. 8 shows a digital image at different resolutions. [0045] [0045]FIG. 9 shows a filter used to make the ripple effect applied to one resolution suitable for any resolution. [0046] [0046]FIG. 10 shows the result of not applying a compensating filter action to the ripple effect. [0047] [0047]FIG. 11 shows a filter used to render the tiles image effectively resolution independent. [0048] [0048]FIG. 12 shows the tiles at different resolutions without the compensating filter action. [0049] [0049]FIG. 13 shows a Fresco effect using a compensating resolution filter. [0050] [0050]FIG. 14 shows the same Fresco effect without the compensating filter action. [0051] [0051]FIG. 15 shows a side-by-side comparison of using a compensating filter action and not using the filter action on a chalk/charcoal image effect. DETAILED DESCRIPTION OF THE EMBODIMENTS [0052] The present invention was originally targeted for deployment on image processing servers, as part of an ASP (Application Service Provider) model that are deployed on systems handling between hundreds to thousands of simultaneous operations at one time. What is desired is a solution that is scalable across many computers. More importantly, it provides consistent results across all image resolutions regardless of the size of the image rendered, but with a decrease in rendering time as the output resolution decreases. [0053] It should be noted that image data could range from between low-resolution (such as 320×240) images up through several mega-pixels images (such as 3000×3000 pixels). Significant performance improvements are realized if a model is developed that permits rendering of these huge images, but performed on low-resolution image data (such as 320×240). This provides not only quick display of images, but also reduces the amount of image data that must be transferred between data storage servers (where image data resides), image processing servers (where the image processing code renders the operations) and the client systems (where the output may be viewed). [0054] This provides several benefits. First, the amount of processing power for each operation is significantly reduced since only a small amount of image data is actually processed. More importantly, in a network environment, only the low-resolution image data must be transmitted between server(s) and the remote client computer. This is particularly important when executing in a low-bandwidth (i.e. 56 Kb modem) environment. [0055] Another benefit realized by this invention is that when processing either resolution-independent or pseudo-resolution-independent image operations, the original image resolution does not have to be accessed, nor must it even be available. In some situations, the original image resolution is not available and may only be available when required for generation of high-resolution printed output. In this case, most of the processing must occur at a lower-resolution, either on the server computer on the client/host computer. This invention provides a solution that results in consistent output even though the original image resolution may not be available. Without this, it would not be possible to guarantee consistent behavior except for resolution-independent image operations. [0056] The processing of lower-resolutions images result in the need of less processing power and lower memory requirements, both of which are critical when developing low-cost consumer electronics digital image devices, including an information appliance, a digital camera, a digital camcorder, a digital television, a digital photo scanner, photo-enabled set-top box, a photo enabled game machine, a photo enabled internet device, cell phone, cable set-top box, WebTV™ or any other computing device that can view images. [0057] Image operations that fall into the Resolution-independent category involve those that yield consistent results across all resolutions. For example, for image A, an imaging operation is applied to an image at a particular resolution and then the image is resized to a smaller resolution. For image B, the image is first resized to the smaller resolution and then the image operation is applied. If image A and image B are sufficiently visually close, taking into account the errors introduced during the resampling/resize operation, the operation is considered resolution-independent. Put another way, when the user views image A and image B side by side, they should visually appear the same. [0058] Some of the following operations that fall into this category including rotation, cropping, translation, color adjustment, color twist, brightness/contrast adjustment (not based on an image's histogram), blur and sharpen operations (as defined by the FlashPix™ imaging model), Duotones (convert the image into a two tone color image), grayscale/black&white, negative, solarize, posterize (reduction in the number of colors), and bi-level/threshold. This is by no means a comprehensive list, but is illustrative of the type of operations that are considered resolution-independent. It should be noted, the FlashPix™ imaging model only supports a small subset of these operations. [0059] There are several classes of pseudo-resolution-independent image processing operations. As additional resolution-dependent image operations are investigated to determine how they can simulate resolution-independent behavior, new classes of pseudo-resolution-independent operations will be created. [0060] Histogram Based Image Operations [0061] This class of image operations modifies a given pixel value based a transform function from the histogram of the image. For example, an auto-enhancement function may look at the histogram and cut off 5% from each end of the histogram and redistribute the histogram across the entire range. [0062] Since the histogram of the original resolution image is close to the histogram of a lower-resolution image this could possibly be considered resolution independent. However while this is generally correct, the assumption breaks down as the resolution becomes very small (such as a 192×192 thumbnail). Therefore, what is desired is an approach that provides true resolution-independence, but without requiring processing of original resolution pixel data each time the image is rendered. [0063] This invention solves this problem by performing the image operation in multiple phases. The Analyze phase is first performed on the image data. This phase processes all the pixel data, ideally at the original image resolution, so that a histogram can be computed. During this phase, the pixels are not modified. Once the histogram is collected, appropriate image operation parameters can be ascertained, such as how the histogram should be redistributed. During the second phase, the Filter phase, the image data is actually modified. The benefit of this approach is that the parameters are resolution-independent and thus, the Filter phase can actually be performed at any resolution, lower or higher than that of the original resolution of the image data. [0064] By performing an Analyze phase on the original image data's resolution and storing those results for future renderings, the Filter phase can be performed at any resolution. This technique simulates resolution-independent behavior across all resolutions. [0065] General Analyze Phase/Filter Phase Utilization [0066] The class of image operations described above is a subset of this category. While the Analyze/Filter phase model is described above in terms of usage for histogram filter operations, it can be used in a more general manner. For example, red-eye reduction and adjust artificial lighting are two image operations that are normally considered resolution-dependent, but can simulate resolution-independence by allowing an Analyze phase to initially be performed at the original image resolution. [0067] The Red-eye reduction filter operation is separable into two pieces: (a) detection of the red-eye and (b) removal/cleanup of the affected area. In order to accurately detect the red-eye in the first place, it is desirable to perform the detection at the original image resolution. Otherwise, a subsampled image may sufficiently blur the area of the eye so that it cannot be accurately detected. Further, if processing occurred on a very low-resolution image, such as a 320×240 screen nail image, it most likely would not be possible to even visually see the red-eye. [0068] Once the detection is performed at the original image resolution, the coordinate and radius of the red-eye is preserved in resolution-independent coordinates. With both the coordinate and radius, it is then possible to remove/cleanup the red-eye at any resolution. If cleanup were applied at a very low-resolution, such as a 320×240 screen nail, the cleanup region would be small. On the other hand, if performed on a very higher-resolution image, the cleanup region would be larger, centered about the coordinate of the red-eye. [0069] The artificial lighting adjustment filter is also an operation that requires this two-phased approach. The first pass is performed to determine how much of a particular light (such as yellow for incandescent lighting) exists in a photo. If more than a certain percentage (i.e. 25% of the photo) contains the particular color range, the image is corrected. Since the determination is based on this fixed percentage, the exact amount may vary slightly depending on the resolution. For example, if exactly 25% of the image contains yellow at the original image resolution. When the image is downsampled, the percentage calculated will usually be slightly below or above 25%. [0070] For consistency across all resolutions, the detection of the color is performed at the original image resolution and stored during the Analyze phase. When rendering occurs, the Filter phase is performed at any resolution, but based on the data collected from the original image resolution data during the Analyze phase. By performing an Analyze phase on the original image data's resolution and storing those results for future renderings, the Filter phase can be performed at any resolution. This technique simulates resolution-independent behavior across all resolutions. [0071] Modification of Internal Parameters [0072] The third class of pseudo-resolution-independent image operations modify internal parameter values, usually based on some constant value or range of values that becomes a function of the resolution of the image. [0073] For example, the ripple filter simulates the effect of dropping a pebble into the pond rendered onto a photo. Most algorithms perform this by simulating a mathematical wave function across the image. In general though, this is dependent upon the size of the image. Therefore, a different number of ripples are seen on different resolutions of the same image. [0074] An alternative approach is having the mathematical wave function that takes as a parameter the resolution of the image such that different resolutions will look similar. (i.e. have the same number of ripples) This is sometimes possible by scaling a parameter, based on the resolution, either linearly or by determining some logarithmic or geometric function to perform the scale. [0075] Multiple Discrete Resolutions [0076] The fourth class of pseudo-resolution-independent image operations selects different discrete internal parameter values for different resolutions. For these image operations, it is generally not possible to define a mathematical function for each internal parameter. [0077] It is possible to simulate resolution-independent behavior by choosing discrete parameter settings for images at different resolutions, so that it is approximated across all resolutions. First, the maximum side of an image is determined. Next, the maximum side is compared to each of the available resolutions. The one that most closely matches is chosen. [0078] Paint Effects are a set of image operations that simulate various artistic effects, such as Chalk/Charcoal or Fresco art effect. For these operations, supported sizes might include: 128, 256, 512, 1024, 2048, and 4086. For images less than 128, the settings associated with 128 are used. There is nothing special about how these numbers are selected. Another image operation may choose to support the following sizes: 200,400,800,1600, and 3200. For any given image operation, a specific set of fixed resolutions is supported. [0079] When an image is rendered that does not have an exact match to the supported size, two approaches are currently used. The most common approach is to choose the parameter settings closest to size of the image being rendered. This approach provides consistent results across all resolutions for many image operations in this class. [0080] An alternative approach is to resize the image to match the correct intermediate size supported by the image operation. In some situations, this results in more consistent rendering across different resolutions, assuming the exact supported resolution of the image operation does not match the desired output resolution. After the operation is applied, the image may need to be resized back to the desired output resolution. If some or all of the image operations support the same size, this may be the more desirable approach since only one resample of the image is needed. Unfortunately, this does produce the negative effect introduced by the additional resampling operation. [0081] Resolution-Dependent Operations [0082] Image operations that fall into this category are by definition not resolution-independent. More importantly, these operations cannot approximate resolution-independence as described in the pseudo-resolution-independent section above. [0083] The goal is to minimize the number of resolution-dependent image operations that are supported, or alternatively not support any resolution-dependent operation. In the past this was not viable since it would result in an application supporting very few imaging operations. By being able to simulate resolution-independence (i.e. psuedo-resolution-independence) at continuous or discrete sets of resolutions, it is now feasible for an application to simply not support resolution-dependent operations as a viable option. [0084] Rendering Implementation Details [0085] In the best mode the rendering pipeline takes into account the characteristics of each of the above image operations, in order to determine how to render each of the image operations in the most efficient manner. These characteristics determine if the image operation is resolution independent, pseudo-resolution-independent, or neither (i.e. resolution-dependent). Further, the relationship between various image operations must be defined since each operation may interact with the others. For example, the application of a Chalk/Charcoal paint effect followed by a rotate result in a different outcome compared to if the rotation were applied prior to the application of the paint effect. [0086] If all operations are resolution-independent, the rendering pipeline is very similar to what is defined by the FlashPix™ image model. In this case, the relationship between the various image operations must still be specified, but all operations can occur on the same resolution. More importantly, all can be performed on low-resolution image data thus requiring less processing power and memory. [0087] Where the benefit of this invention becomes more apparent is when one or more of the image processing operations includes a pseudo-resolution-independent image operation. In this case, rendering may be required at some predetermined resolution, close to the desired output resolution, but does not require the image data at the original resolution to be accessed or rendered. [0088] Base Pipeline Implementation for this Invention [0089] Now referring to FIG. 4, a flowchart is shown detailing the process for rendering the image as defined by this invention. The process 400 begins at 402 when a particular digital image is opened by the application. At 404 , the resolution of the digital image is determined and recorded in originalImageResolution. At 406 , the resolution of the output device is determined and the variable finalOutputResolution is set to this value. [0090] At 408 , it is determined, via process 500 , what the initial working resolution should be and currentOutputResolution is set to this value. At 410 , the image is copied to an appropriate buffer and is resized to match the resolution specified in 408 and control is passed to 412 . [0091] At 412 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, control is pass to 450 . Otherwise, at 414 it is determined if the image operation is a resolution-independent operation. If it is not a resolution-independent operation, control is passed to 420 (FIG. 4 a ). Otherwise, control is passed to 416 where the image operation is performed at the currentOutputResolution. Control is then passed back to 412 . [0092] At 420 (FIG. 4 a ), it is determined if the operation is pseudo-resolution-independent If it is, control is passed to 422 . Otherwise, control is passed to 440 since it is a resolution-dependent operation. At 440 , the bestResolutionForImageOperation is set to originalImageResolution, since it is a resolution-dependent operation. Control is then passed to 442 [0093] At 422 , it is a pseudo-resolution-independent operation. There it is determined if a DoAnalyze phase is required. If it is required, then at 424 the DoAnalyze phase is handled, via process 600 after which control is passed to 426 . If no DoAnalyze phase is required, control is passed directly to 426 where it is determined, via process 700 , what the closest supported resolution for this pseudo-resolution-independent image operation is and sets bestResolutionForImageOperation to this value. Control is then passed to 442 . [0094] At 442 , if the bestResolutionForImageOperation matches currentOutputResolution, control is then returned to 416 (FIG. 4) where the image operation is performed on the image. If the resolutions do not match, control is passed to 444 where the image is resized to match the bestResolutionForImageOperation. At 446 , the currentOutputResolution is set to the bestResolutionForImageOperation. Control is then returned to 416 (FIG. 4) where the image operation is performed on the image. [0095] At 450 (FIG. 4), all image operations have been performed and the values currentOutputResolution and finalOutputResolution are compared. If these are equal, control is passed to 454 where the processed image is sent to the output display device. Otherwise, control is passed to 452 where the image is resized/resampled to match the finalOutputResolution. Control is then passed to 454 where the processed image is sent to the output display device. [0096] It is clear from the flowchart that if all image operations are resolution-independent, and can be performed at any resolution, then all operations are performed at the finalOutputResolution. However, when an image operation is resolution-dependent, it must be performed at the original resolution of the image (originalImageResolution). After all image operations have been performed, the image must then be rescaled/resampled back the finalOutputResolution before it is passed to the output device. [0097] In general, when processing the pseudo-resolution-independent operations, either no resampling is required (bestResolutionForImageOperation and finalOutputResolution are the same), or a resolution much closer to the finalOutputResolution is used compared with requiring the originalImageResolution if it were a resolution-dependent operation. [0098] Determination of the initial working resolution (Process 500 /FIG. 5) Several different heuristics are applied to determine the ideal resolution for a given image operation (bestResolutionForImageOperation). This value is dependent upon the image operation in question so a general approach is listed below. [0099] A general rule is that it is best not to alter the currentOutputResolution if possible. This preserves image fidelity. Ideally, bestResolutionForImageOperation is the same at the finalOutputResolution such that resampling/rescaling as performed in step 452 of FIG. 4 is not needed. However, this sometimes is not possible. [0100] The next approach is to find a resolution that is consistent and works across all image operations. In this way, at most two resample operations need to be performed: a resample from the originalImageResolution to the targetResolution (for this case, it is the same for all operations) and a final resample to the finalOutputResolution required by the output device. If all image operations can work at the same resolution, no additional resampling is needed. Process 500 and 700 take these rules and approaches into account during its computation. [0101] It is a design goal of the pseudo-resolution-independent image operations to support resolution-independence for a specific discrete set of resolutions provided the continuous range model is not feasible. In the preferred embodiment, this discrete set is the same for all psuedo-resolution-independent operations. In this way, it reduces the amount of resampling required. Even if this is not possible, the pseudo-resolution-independent image operations are still preferred over resolution-dependent operations since rendering usually does not need to occur at the originalImageResolution [0102] Now referring to FIG. 5, process 500 is shown that details the process of selecting the single best resolution for the series of image operations that are to be processed, based on originalImageResolution and the finalOutputResolution. Technically, this process is optional. One implementation of process 500 would be to simply return finalOutputResolution as “single best resolution”. This is valid since process 700 results in the resize of the image to meet the needs of the specific image operation(s). [0103] However, it is advantageous to limit the amount of resampling that occurs, since it results in image degradation. A more desirable approach is to opportunistically find the single best image size for all image operations that are being performed. This may not always be possible, but in the preferred embodiment an attempt is made to find the best initial resolution. [0104] The process 500 begins at 502 where targetResolution is set to the smaller of originalImageResolution and finalOutputResolution. The assumption is that when performing operations at less than the originalImageResolution, it is ok to perform the operations at the finalOutputResolution. This is because the operations are assumed to be resolution-independent or pseudo-resolution independent and result in consistent output, even though it is processed at finalOutputResolution, opposed to the originalImageResolution. However, if the operation is performed at greater than the originalImageResolution, it is acceptable to perform it on the originalImageResolution. This is a performance/memory tradeoff since it is assumed that for this case, performing the operations at the originalImageResolution and then resampling the image to match the finalOutputResolution is acceptable. For some systems and operations this may not be desirable and in those embodiments, the targetResolution is set to finalOutputResolution at 502 (see section 4.1 on High Resolution Processing). [0105] At 504 , a determination is made if any image editing operations should be performed. If no image operations are to be performed, then control is passed to 550 . Otherwise, at 506 it is determined if all image editing operations are of type resolution-independent. If true, then control is pass to 550 . Otherwise, control is passed to 510 . [0106] At 510 , it is determined if all image operations are of type pseudo-resolution-independent or resolution-independent. If false, control is passed to 530 . Otherwise, at 512 , it is determined if all operations support the targetResolution. If true, control is pass to 550 . Otherwise, control is passed to 516 . [0107] At 516 , it is determined if all the pseudo-resolution-independent image operations support some “common resolution” closest to the targetResolution. By examining each operation, it is determined if one resolution, which is closest to the targetResolution, is supported. If this is true, then control is pass to 518 where the targetResolution is set to this “common resolution” and control is passed to 550 . Otherwise, control is passed to 530 . [0108] At 530 , either no common resolution has been determined or the operation is resolution-dependent. Therefore, the targetResolution is set to originalImageResolution so processing can be performed on the original image resolution, thus guaranteeing consistent results across all resolutions. Control is then passed to 550 . [0109] In the preferred embodiment, step 530 does not occur since some common targetResolution, close to the finalOutputResolution, is always determined for all supported imaging operations in the PictureIQ imaging system. If this were not the case, the pseudo-resolution-independent operation would be treated the same as resolution-dependent operations. In the future, additional work will be done, such as reordering of operations so that those operations that are resolution-independent or are pseudo-resolution-independent and with a resolution close to the finalOutputResolution will be performed first. [0110] At 550 , the targetResolution is returned to the caller. [0111] Handle DoAnalyze Phase (Process 600 /FIG. 6) [0112] Now referring to FIG. 6, a flowchart is shown detailing the process for handling the DoAnalyze phase as defined by this invention. The process 600 begins at 602 where it is determined if results from a previous DoAnalyze phase exists and are still valid. If this is true, control is passed to 650 . Otherwise, at 604 , it is determined if the DoAnalyze can be performed at the currentOutputResolution. If this is true, at 606 the DoAnalyze is performed at the currentOutputResolution and control is passed to 650 . If this is not the case, the DoAnalyze must be performed at the originalImageResolution at 608 . [0113] At 608 , it is determined if it is sufficient to resize the accumulated results at the currentOutputResolution to the originalImageResolution, or if all image operations must be reapplied to the original image at the originalImageResolution. If reprocessing of all operations at the originalImageResolution is required, control is passed to 620 . Otherwise, at 610 the working image is copied into a separate buffer. At 612 , the working image is resized to the originalImageResolution. Control is then passed to 606 , where the DoAnalyze is performed. [0114] At 620 , the original image at the originalImageResolution is retrieved. At 622 , it is determined, based on the current image operation needing the DoAnalyze data, which operations in the sequence up to this operation are to be applied at the original resolution. This may vary depending on the operation. After the original resolution image has been processed, control is then passed to 606 , where the DoAnalyze is performed. [0115] At 650 , the DoAnalyze phase is complete and all internal variables are persisted/saved. Control is then returned to the caller. [0116] Determine closest supported resolution (Process 700 /FIG. 7) Now referring to FIG. 7, process 700 is shown detailing the process of selecting the best resolution (bestResolutionForImageOperation) for a given image operations that is being processed, based on originalImageResolution and the currentOutputResolution. Process 700 starts at 702 where the closest supported resolution for the current image operation compared to the currentOutputResolution is determined and bestResolutionForImageOperation is set to this value. [0117] Unable to find a consistent resolution for all operations. In the preferred embodiment, it is always possible to find a close resolution, generally much smaller than the originalImageResolution that is supported by all pseudo-resolution-dependent operations. By definition, all PictureIQ image operations fall into this category. [0118] In some embodiments, this might not be possible. When this occurs, the originalImageResolution can be used. However, it is generally not desirable to resample the image each time an operation is applied since this results in image degradation. [0119] In another embodiment, if there are two or three common required resolutions needed for all image operations, it may be desirable to support each, with the overhead of additional resample operations to scale between the various operations as needed. This is an application specific tradeoff that must be made based on the ability to re-order the operations. [0120] Handling of Resolution-Dependent Image Operations [0121] While it is true that the maximum benefit of this invention is realized when the image operations utilized are either resolution-independent or pseudo-resolution-independent, other benefits are still possible. For example, it may be possible to re-order the image operations such that the resolution-dependent operations can be performed later (or ideally last) in the sequence of all image operations that are to be performed. [0122] By doing this, many of the image operations that are either resolution-independent or pseudo-resolution-independent can be performed at a lower resolution, ideally at or close to the finalOutputResolution. After those operations have been performed quickly at the finalOutputResolution, the image must be resampled to the originalImageResolution for processing of the resolution-dependent operations. Finally, the image must then be resampled back to the finalOutputResolution. It is application dependent if the potential quality loss or the extra time/resources needed for the resample operations incurred is worth the tradeoff. [0123] While the most significant benefit of this invention is the ability to perform an image operation on much lower resolution image data, other benefits are realized when processing higher resolution image data compared to the original. [0124] Generally, most applications apply the image operations at the original image resolution and resize the image accordingly, smaller or larger, to match the output device. When outputting to a high-resolution print device, the resolution of the printer is generally much higher than that of the original image resolution. In this case, the original image with all the operations applied is resized/resampled to a larger resolution to match the printer. [0125] The drawback with this approach is that resampling to a larger resolution introduces other artifacts, including pixelation (blockiness) and other aliasing effects. This is because higher resolution image data must be “created” since it does not already exist. To circumvent this problem, high frequencies of the image (where pixelation is most prevalent) is slightly blurred to lessen the effects of the aliasing. [0126] If an image processing operation is performed that attenuates the edges (such as a sharpen operation or accented edges), the resample operation may have the effect of either introducing blockiness or a degree of blurring. Each of these is not desirable. [0127] An alternative approach, made possible by this invention, is to first resample the image to match the resolution of the output device, without apply any image operations. Next the various resolution-independent or pseudo-resolution-independent operations are performed at the high-resolution (presumable higher than the original image resolution). This is not possible for any operation that is resolution-dependent since it would result in inconsistent results. [0128] In general, care must be taken if this approach is used. This increases the processing time, and memory requirements, of each image processing operation since they are performed on very high-resolution image data. Further, if any operations are resolution-dependent, they must be performed at the original image resolution [0129] The more likely scenario is to use a hybrid approach that results in processing some of image operations at the original image resolution including all resolution-dependent operations. Then the image is resampled and the subset of resolution-independent or pseudo-resolution-independent operations that exhibit undesirable artifacts as a result of the resample/resize operation is performed at the higher resolution. This assumes that some operations can be reordered. [0130] This invention has been designed to provide consistent results across all resolution. As stated earlier, for image A, an imaging operation is applied to an image at a particular resolution and then the image is resized to a smaller resolution. For image B. the image is first resized to the smaller resolution and then the image operation is applied. If image A and image B are sufficiently close, taking into account the errors introduced during the resampling/resize operation, the operation is considered resolution-independent. Put another way, when the user views image A and image B side by side, they should visually appear the same. [0131] While in theory, if this assumption holds, the affects of resolution-independence are achieved. For some limited set of resolution-independent or pseudo-resolution-independent operations, this may not be entirely correct. Certain artistic effects exhibit this characteristic. When the effect is applied to the original resolution image, it is visible. However, when the original resolution image, with the effect already applied, is resampled to a screen nail or thumbnail, it becomes less visible or not visible at all. [0132] From an image-processing standpoint, the effect of resampling the image down to a smaller resolution reduces the effects of the image processing operation. For example, if a sharpen operation is applied at the original resolution and then the result is resampled to a smaller resolution, the amount of sharpen appears less at lower resolutions. This is because the resample operation tends to blur sharp edges and reduces the effect of the sharpen operation. [0133] This section presents output that shows the results from using resolution-independent techniques when performing the same operation on several different resolutions, both from resolution-dependent and pseudo-resolufion-independent operations. FIG. 8 shows the original image at different resolutions. [0134] Each section shows four resolutions: 100×67, 200×134, 400×286, and 800×536. The operations are applied at each resolution. Note, the 800×536 image has the operation applied at that resolution and is subsequently resampled down to fit into this document. This allows for direct comparison between the 800×536 and 400×286 resolution. In theory, a pure resolution-independent operation should yield identical results when output is compared side-by-side at the same view size. [0135] [0135]FIGS. 9 and 10 show the output for the ripple filter for a pseudo-resolution-independent version and a resolution-dependent version of the same filter. Notice how the appearance of the ripple effect changes with the resolution in figures shown for the resolution-dependent output. This is an example of a filter in which internal parameters to the algorithm are modified based on the resolution. [0136] [0136]FIGS. 11 and 12 show the output for the mosaic tiles filter for both versions. Notice how the number of tiles changes based on the resolution in the figures shown for the resolution-dependent output. This is an example in which the internal parameters to the algorithm are modified based on the resolution. [0137] [0137]FIGS. 13 and 14 show the output for the Fresco paint effect. Notice the significant difference between the various resolutions for the resolution-dependent output. This is an example in which a discrete set of resolutions is supported. To the keen eye, some differences may be seen between different resolutions of the figures shown for the resolution-independent output, but still very similar. Clearly, this is much better than the resolution-dependent output. [0138] It is important to note, if an application using today's technology (without this invention) wants to achieve the same results across all resolutions, the processing must be performed at the original image resolution. For the Fresco effect, the original image at 1600×1072 takes 11 seconds to complete processing on that resolution running on a 750 MHz Intel Pentium III, in comparison to less than 1 second for the same rendering of a 400×286 or smaller image using pseudo-resolution-independent techniques. [0139] [0139]FIG. 15 shows side-by-side results from the output for the Chalk/Charcoal paint effect using pseudo-resolution-independent and resolution-independent techniques. This is an example in which a discrete set of resolutions is supported. For comparisons, it is sometimes helpful to view the same sized output side-by-side since these techniques try to approximate the same results across all resolutions. The best way for the comparison, at the pixel level, is to view each image at the same size, regardless of resolution. [0140] The comparison shows how the different resolutions compare when viewed at the same size. In this case, the 200×134 is viewed at 100%, but the 400×268 is viewed at 50% and the 800×536 is viewed at 25%. When viewed this way, a more accurate determination can be made about how close the resolutions compare side-by-side. [0141] For Chalk/Charcoal, more differences are visible between resolutions using the pseudo-resolution-independent technique. The primary reason for this is due to the fact that when working at lower-resolutions, a certain amount of data is already lost and must be approximated. The same situation exists for a high-resolution photo that is resampled down to a screen nail (320×240) and then enlarged (zoomed in) for comparison with the original. Clearly, there is data loss similar to what is shown in the figures in section 5.8. This should be expected. It is just that certain image operations can perform better at lower-resolutions and are able to “better create” this resolution. [0142] While the present invention has been described as being used with a digital image system (video or still), it should be appreciated that the present invention may generally be implemented on any suitable digital image system. This includes a PC-based imaging application, Web sharing applications that permit sharing, distribution, or viewing of image data between a central server and a client, as well as direct enduser peer-to-peer connected systems. [0143] It can be included as part of an embedded information appliance or digital image device and can work equally well in both a wired network environment as well as a wireless environment. [0144] This disclosure of a system and method to render image data to simulate pseudo-resolution-independent behavior according to the preferred embodiments of the present invention is merely exemplary in nature and is no way intended to limit the invention or its application or uses. Further, in the above description, numerous specific details for implementation are set forth to provide a more thorough understanding of the present invention disclosure. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, characteristics and functions of the well known processes have not been described so as not to obscure the present invention.

A method to improve the performance of rendering image data ( 402 ) by converting what would normally be considered resolution-dependent image behavior into behavior that is substantially resolution-independent. This allows significant performance improvement since the rendering ( 454 ) can be performed on the lower-resolution image data used, for example, for on-screen viewing and when the image effect is applied to a higher resolution rendering, the effect, as viewed, is substantially the same as the effect viewed at a lower resolution. This conversion of normally resolution-dependent behaviors into pseudo-resolution-independent behaviors also allows the image effects to be applied to be carried out on a lower resolution image with confidence that when the image is rendered at a higher resolution that the image effects applied will substantially have the same appearance that the effect had at the lower resolution.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a method and apparatus for extruding unvulcanized rubber, in which an unvulcanized rubber member comprised of at least two kinds of unvulcanized rubbers is extruded. [0003] 2. Description of the Related Art [0004] In an automobile pneumatic tire, there are some cases in which a rubber chafer comprised of hard rubber may be provided at the outer side of a tire bead portion so as to increase rigidity of the bead portion. [0005] An upper end of the rubber chafer is connected to a side-wall rubber layer which forms a side wall of the tire. [0006] However, there are cases in which, because the bead portion is repeatedly subjected to bending deformation when the vehicle is running, the rubber chafer and the side-wall rubber layer are separated from each other. [0007] In order to solve the aforementioned problem, it has been considered that an area in which the rubber chafer and the side-wall rubber layer are connected can be increased, and a pneumatic tire having a cross sectional configuration as shown in FIG. 7 has been proposed. [0008] In the pneumatic tire having the cross sectional configuration shown in FIG. 7 , an inner portion 106 A provided at a radial-direction inner side of a side-wall rubber layer 106 which forms a side wall 104 , and an outer portion 106 B provided at an outer side of the side-wall rubber layer 106 are formed so as to cover inner and outer surfaces, in an axial direction of the tire, of a rubber chafer 102 tapered in an upward direction, and an area in which the side-wall rubber layer 106 and the rubber chafer 102 are connected is increased so as to strengthen the junction between the side-wall rubber layer 106 and the rubber chafer 102 . [0009] In order to manufacture such a pneumatic tire, in a process for producing a green tire, a rubber extruded member 108 in which the unvulcanized side-wall rubber layer 106 and the unvulcanized rubber chafer 102 having the cross sectional configuration as shown in FIG. 8 are integrated with each other is produced. Thereafter, a rubber sheet 110 comprised of unvulcanized rubber of the same kind as the side-wall rubber layer 106 is adhered so as to cover a region of the rubber extruded member 108 in the vicinity of the end of the rubber chafer 102 . [0010] The rubber extruded member 108 with the rubber sheet 110 adhered thereto is applied to an outer surface of a carcass of a tire case in a production process. Thus, the pneumatic tire is manufactured. [0011] However, there conventionally existed a problem that equipment for adhering the rubber sheet 110 or a process for adhering the sheet may be required, and equipment investment and stock handling of the rubber sheet 10 may also increase. [0012] Further, because the thick rubber sheet 110 is adhered to the rubber extruded member 108 , a stepped portion 112 is formed on the surface of the rubber extruded member 108 , as shown in FIG. 8 . For this reason, air in the stepped portion 112 may cause bare. Moreover, losses due to spoiled products caused by incorrect setting may also increase. SUMMARY OF THE INVENTION [0013] An object of the present invention is to provide a method and apparatus for extruding unvulcanized rubber, in which equipment investment for tires is held down, the number of manufacturing steps is not increased, and an unvulcanized rubber extruded member from which a high quality tire is produced can be formed by extrusion. [0014] A first aspect of the present invention is an apparatus for extruding unvulcanized rubber which comprises a first extruder main body for extruding a first unvulcanized rubber, a second extruder main body for extruding a second unvulcanized rubber, an extrusion head which connects a leading end of the first extruder main body and the second extruder main body, and a passage-forming die for guiding, at a leading end of the extrusion head, the first unvulcanized rubber and the second unvulcanized rubber toward a die plate having an opening, wherein an extruded rubber member is formed by extrusion, the extruded rubber member having a cross sectional configuration in which, when seen from a cross section perpendicular to a direction in which the extruded rubber member is extruded, a portion of the second unvulcanized rubber intrudes into the first unvulcanized rubber and a portion of the first unvulcanized rubber is disposed at both sides of the intruded second unvulcanized rubber in a direction intersecting a direction in which the second unvulcanized rubber intrudes, the apparatus comprising: a first passage through which the first unvulcanized rubber passes; a second passage provided adjacent to or connected to the first passage and making the second unvulcanized rubber to pass therethrough; and a flow dividing mechanism provided at one of a portion at which the first passage and the second passage are disposed adjacently and a portion at which these passages are connected, and separating a portion of the first unvulcanized rubber passing through the first passage to allow the first unvulcanized rubber to be disposed at both sides of the intruded second unvulcanized rubber in a direction intersecting a direction in which the second unvulcanized rubber intrudes. [0015] In the apparatus for extruding unvulcanized rubber, the first unvulcanized rubber and the second unvulcanized rubber are each delivered to the passage-forming die by using the first extruder main body and the second extruder main body, respectively. [0016] The first unvulcanized rubber passes through the first passage formed in the passage-forming die and the second unvulcanized rubber passes through the second passage formed in the passage-forming die. [0017] The flow dividing mechanism provided between the first passage and the second passage divides a portion of the flowing first unvulcanized rubber passed through the first passage so that the first unvulcanized rubber is disposed in the extruded rubber member at both sides of the intruded second unvulcanized rubber in a direction intersecting a direction in which the second unvulcanized rubber intrudes. [0018] As a result, the extruded rubber member is readily obtained by one extrusion process, and the member has a cross sectional configuration in which, when seen in a cross section perpendicular to a direction in which the extruded rubber member is extruded, at a boundary portion between the first unvulcanized rubber and the second unvulcanized rubber, a portion of the second unvulcanized rubber intrudes into the first unvulcanized rubber, and a portion of the first unvulcanized rubber is disposed at both sides of the intruded second unvulcanized rubber in a direction intersecting a direction in which the second unvulcanized rubber intrudes. [0019] In the apparatus for extruding unvulcanized rubber of the present invention, preferably, the flow dividing mechanism includes a first weir disposed at an upstream side of the die plate and apart from the die plate, and protruding from the second passage side toward the first passage in a direction perpendicular to a direction in which the unvulcanized rubbers pass. [0020] In the aforementioned apparatus for extruding unvulcanized rubber, the weir formed so as to protrude from the second passage toward the first passage in a direction perpendicular to a direction in which unvulcanized rubber passes is provided at the upstream side of the die plate and apart from the die plate. For this reason, the direction in which a portion of the first unvulcanized rubber passes through the first passage can be changed so that the portion of the first unvulcanized rubber rides over a protruding end of the weir, and the direction in which the other portion of the first unvulcanized rubber flows can be changed so that the other portion of the first unvulcanized rubber flows laterally around the weir in a direction perpendicular to a direction in which the weir protrudes. [0021] As a result, the portion of the first unvulcanized rubber is disposed at one side of the intruded second unvulcanized rubber in the direction in which the second unvulcanized rubber intrudes, and the other portion of the first unvulcanized rubber is disposed at another side of the intruded second unvulcanized rubber. [0022] A second aspect of the present invention is a method for extruding unvulcanized rubber, in which an extruded rubber member is formed by extrusion by an extruding apparatus, the extruded rubber member having a cross sectional configuration in which a portion of the second unvulcanized rubber intrudes into the first unvulcanized rubber and a portion of the first unvulcanized rubber is disposed at both sides of the intruded second unvulcanized rubber in a direction intersecting a direction in which the second unvulcanized rubber intrudes, the method comprising the steps of: dividing a portion of the flowing first unvulcanized rubber into two flows at an upstream side of a die plate including an opening in the extruding apparatus; allowing a portion of the second unvulcanized rubber to intrude in between the two flows into which the portion of the first unvulcanized rubber is divided; and extruding, from the opening of the die plate, an extruded rubber member in which the first unvulcanized rubber and the second unvulcanized rubber are integrated with each other. [0023] In the method for extruding unvulcanized rubber, a portion of the flowing first unvulcanized rubber is divided into two parts at the upstream side of the die plate having the opening for the extruding apparatus, and a portion of the second unvulcanized rubber is caused to intrude in between the two divided flows of the first unvulcanized rubber. Thereafter, the first unvulcanized rubber and the second unvulcanized rubber are integrated with each other and an extruded rubber member having the first and second unvulcanized rubbers integrated is extruded from the opening of the die plate. [0024] In the aforementioned method for extruding unvulcanized rubber of the present invention, preferably, the extruding apparatus includes a flow dividing mechanism including a first weir which is provided at the upstream side of the die plate and apart from the die plate and which protrudes in a direction perpendicular to a direction in which the first unvulcanized rubber passes, the first unvulcanized rubber and the second unvulcanized rubber are caused to intersect with each other by allowing the second unvulcanized rubber to pass over the first weir. [0025] Further, preferably, the flow dividing mechanism includes a second weir extending from the first weir to the die plate, and the position of one of leading ends of two divided flows of the first unvulcanized rubber disposed at both sides of the second unvulcanized rubber is changed by the position of the second weir. [0026] Moreover, the aforementioned method, preferably, further comprises a step of: causing a portion of a third unvulcanized rubber to intrude into the first unvulcanized rubber, and an extruded rubber member having a region in which the first unvulcanized rubber and the third unvulcanized rubber are integrated with each other is extruded from the opening of the die plate. BRIEF DESCRIPTION OF THE DRAWINGS [0027] FIG. 1A is a back view of a passage-forming die as seen from a side of extruders. [0028] FIG. 1B is a cross sectional view taken along the line 1 (B)- 1 (B) of the passage-forming die shown in FIG. 1A . [0029] FIG. 2 is a side view which schematically shows structure of an unvulcanized rubber extruding apparatus. [0030] FIG. 3 is a cross sectional view of an unvulcanized rubber member formed by extrusion by the unvulcanized rubber extruding apparatus. [0031] FIG. 4 is a longitudinal cross sectional view of an extrusion head. [0032] FIG. 5 is a perspective view showing a portion of the passage-forming die. [0033] FIG. 6A is a cross sectional view taken along the line 6 (A)- 6 (A) of the passage-forming die shown in FIG. 1A . [0034] FIG. 6B is a cross sectional view taken along the line 6 (B)- 6 (B) of the passage-forming die shown in FIG. 1A . [0035] FIG. 6C is a cross sectional view taken along the line 6 (C)- 6 (C) of the passage-forming die shown in FIG. 1A . [0036] FIG. 7 is a cross sectional view showing a bead portion of a conventional pneumatic tire. [0037] FIG. 8 is a cross sectional view of a conventional unvulcanized rubber member. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0038] An embodiment of an unvulcanized rubber extruding apparatus of the present invention will be described hereinafter with reference to FIGS. 1 to 6 . [0039] As shown in FIG. 2 , the unvulcanized rubber extruding apparatus 10 has three extruder main bodies 12 , 14 and 16 , and an extrusion head 18 to which ends of the extruder main bodies 12 , 14 and 16 are connected. [0040] The extruder main bodies 12 , 14 and 16 each include a hopper (not shown) for supplying unvulcanized rubber, and three kinds of unvulcanized rubbers A, B and C having different compositions are continuously supplied from the hoppers to the extruder main bodies 12 , 14 and 16 , respectively. The supplied unvulcanized rubbers A, B and C are each kneaded by screws (not shown) driven to rotate within the extruder main bodies 12 , 14 or 16 . As a result, the unvulcanized rubbers A, B and C are caused to flow toward the extrusion head 18 while exhibiting enhanced fluidity due to a self-exothermic property and increased plasticity. [0041] The extruder main bodies 12 , 14 and 16 each have the same structure as in a conventional system. [0042] Next, an unvulcanized rubber member 19 formed by extrusion with the unvulcanized rubber extruding apparatus 10 will be described with reference to FIG. 3 . [0043] As shown in the cross sectional view of FIG. 3 , an unvulcanized rubber member 19 is comprised of the three kinds of unvulcanized rubber, that is, the unvulcanized rubber A for forming a rubber chafer, the unvulcanized rubber B for forming a side-wall rubber layer, and the unvulcanized rubber C for a cushion rubber layer to be disposed at an inner side of a tread at a position near a tire shoulder. The unvulcanized rubber member 19 is formed by extrusion so as to become wide in a horizontal direction, that is, in the direction indicated by arrows L and R. [0044] In the unvulcanized rubber member 19 , a substantially V-shaped groove portion Ba is provided at an end of the unvulcanized rubber B (the side-wall rubber layer) in the direction indicated by arrow L. At the end of the unvulcanized rubber B, a lower portion of the groove portion Ba is formed as an inner portion Ba 1 along an inner surface of a carcass of a product tire, and an upper portion of the groove portion Ba is formed as an outer portion Ba 2 along an outer wall surface of the tire. [0045] The inner portion Ba 1 and the outer portion Ba 2 are each formed so as to be tapered with the thickness thereof being gradually decreased toward the end in the direction indicated by arrow L. [0046] The unvulcanized rubber A (rubber chafer) extends in the widthwise direction in the same manner as the unvulcanized rubber B (side-wall rubber layer), that is, in the direction indicated by arrows L and R, and is formed in a tapered manner so that the thickness thereof gradually decreases from a thick central portion to both ends in the widthwise direction. [0047] The end of the unvulcanized rubber A (rubber chafer) at the side of the unvulcanized rubber B (side-wall rubber layer) is covered such that the upper surface thereof is in contact with the outer portion Ba 2 and the lower surface thereof is in contact with the inner portion Ba 1 . [0048] The other end of the unvulcanized rubber B (side-wall rubber layer) in the direction indicated by arrow R is formed in a tapered manner so that the thickness thereof gradually decreases toward the end. [0049] The unvulcanized rubber C (cushion rubber layer) is disposed at the end of the unvulcanized rubber B (side-wall rubber layer) in the direction indicated by arrow R. The unvulcanized rubber C may not necessarily be required, depending on the type of tire. [0050] The unvulcanized rubber C (cushion rubber layer) is formed in a tapered manner so that the thickness thereof gradually decreases from the central portion to the both ends thereof in the widthwise direction. A portion of the unvulcanized rubber C in the direction indicated by arrow L is covered by the other end of the unvulcanized rubber B (side-wall rubber layer) from an upper side. [0051] Next, the unvulcanized rubber extruding apparatus 10 will be described in detail. [0052] As shown in FIG. 4 , the extrusion head 18 includes an extrusion die plate (hereinafter referred to as “die plate”) 20 positioned at a front side in a direction in which the unvulcanized rubbers A, B and C are extruded, and also includes passages 22 a , 22 b and 22 c for the unvulcanized rubbers A, B and C, which are directed toward the die plate 20 from extrusion orifices of the extruder main bodies 12 , 14 and 16 . Further, the extrusion head 18 detachably accommodates an unvulcanized rubber member-forming device 24 for forming the unvulcanized rubber member 19 , in which the unvulcanized rubbers A, B and C each have a predetermined cross sectional configuration, at a position between ends of the passages 22 a , 22 b and 22 c and the front side of the die plate 20 . [0053] The unvulcanized rubber member 19 is extruded from the die plate 20 in the direction indicated by arrow F in FIG. 4 . [0054] The unvulcanized rubber member-forming device 24 has a back die 26 which serves to form a bottom portion of an outer contour of the die plate 20 to make a pair together with the die plate 20 , a die holder 28 for holding and fixing the die plate 20 to the extrusion head 18 , and a back die holder 30 for holding and fixing the back die 26 to the extrusion head 18 . [0055] In the unvulcanized rubber member-forming device 24 , a passage-forming die 32 is provided between the ends of the passages 22 a , 22 b and 22 c of the extrusion head 18 and the die plate 20 . [0056] As shown in FIGS. 1A, 1B , 5 , 6 A, 6 B and 6 C, the passage-forming die 32 includes, at a central portion thereof, a passage 34 b through which the unvulcanized rubber B flows, and also includes a passage 34 a through which the unvulcanized rubber A flows, at a side in the direction indicated by arrow L, and a passage 34 c through which the unvulcanized rubber C flows, at a side in the direction indicated by arrow R. [0057] The passage 34 a and the passage 34 b are connected to each other. [0058] The passage 34 a has a stepped portion 36 at a side in the direction indicated by arrow U. [0059] A first weir 38 , which serves as a flow dividing mechanism, is provided at an end of the stepped portion 36 in the direction indicated by arrow D (that is, a portion at which the passage 34 a and the passage 34 b are connected) so as to protrude toward the passage 34 b in the direction indicated by arrow D. [0060] As shown in FIG. 1A , the dimension of the first weir 38 protruding toward the passage 34 b is gradually made shorter from a substantially intermediate portion thereof in the direction indicated by arrow L. [0061] An end 38 a of the first weir 38 in the direction indicated by arrow D is disposed at a substantially intermediate position with respect to an opening portion 40 formed by the die plate 20 in a direction corresponding to thickness of the rubber extruded member. As shown in FIG. 6B , the end 38 a of the first weir 38 extends to a position near an intermediate portion of the cross section of the passage 34 b in a vertical direction of the die (that is, in the directions indicated by arrows U and D). [0062] A partition wall 42 is integrally formed with the end of the first weir 38 in the direction indicated by arrow R so as to protrude toward the passage 34 b. [0063] The partition wall 42 is formed upright from the first weir 38 so as to reach the extrusion head 18 (in the direction indicated by arrow B). [0064] A second weir 44 is provided between the first weir 38 and the die plate 20 so as to protrude toward the passage 34 b from a side surface 36 b of the stepped portion 36 located at a side in the direction indicated by arrow F. [0065] The end of the second weir 44 reaches the opening portion of the die plate 20 . [0066] The passage 22 a of the extrusion head 18 is opened at a position which faces the stepped portion 36 , and the passage 22 b is opened at a central portion of the passage 34 b in the widthwise direction. [0067] Further, an opening of the passage 34 c at the side of the die plate 20 is located in the vicinity of an end of the passage 22 b at the side in the direction indicated by arrow R. [0068] Next, the operation of the unvulcanized rubber extruding apparatus 10 will be described. [0069] First, the unvulcanized rubbers A, B and C are delivered by the extruder main bodies 12 , 14 and 16 , respectively, toward the extrusion head 18 . The unvulcanized rubber A is fed into the passage 34 a via the passage 22 a , the unvulcanized rubber B is fed into the passage 34 b via the passage 22 b , and the unvulcanized rubber C is fed into the passage 34 c via the passage 22 c. [0070] In the passage-forming die 32 , the unvulcanized rubber A flows toward the die plate 20 as indicated by arrows a 1 and a 2 , the unvulcanized rubber B flows toward the die plate 20 as indicated by arrows b 1 , b 2 , b 3 and b 4 , and the unvulcanized rubber C flows toward the die plate 20 as indicated by arrows c 1 and c 2 . [0071] As a result, the unvulcanized rubber A is pushed out from the die plate 20 at the side in the direction indicated by arrow L, and the vulcanized rubber C is pushed out from the die plate 20 at the side in the direction indicated by arrow R. The unvulcanized rubber B is pushed out from the central portion of the die plate 20 . [0072] Specifically, the flow of unvulcanized rubber A is partially changed by the first weir 38 in the direction indicated by arrow D so as to ride across the first weir 38 as shown by the arrow a 2 , and thereafter, the unvulcanized rubber A flows toward the die plate 20 in the direction indicated by arrow F. [0073] Further, as shown in FIGS. 1A and 1B , at the die plate 20 side of the first weir 38 (in the direction indicated by arrow F), a portion of the unvulcanized rubber B flows in the direction indicated by arrow L as indicated by arrow b 2 at the side of the direction indicated by arrow U (at the side of the stepped portion 36 ) in which the unvulcanized rubber A flows as indicated by arrow a 2 . Moreover, at the side of the direction indicated by arrow D (at the side of the end 38 a ) in which the unvulcanized rubber A flows as indicated by arrow a 2 , a portion of the unvulcanized rubber B flows toward the die plate 20 in the direction of arrow F in such a manner as indicated by arrow b 1 . [0074] In other words, as shown by the cross sectional view of FIG. 3 , in the unvulcanized rubber member 19 formed by extrusion, the flow of the unvulcanized rubber B indicated by arrow b 2 forms the outer portion Ba 2 , and the flow of the unvulcanized rubber B indicated by arrow b 1 forms the inner portion Ba 1 . [0075] The end of the outer portion Ba 2 of the unvulcanized rubber B can be changed by the position of the second weir 44 which changes the direction in which the unvulcanized rubber B flows as indicated by arrow b 2 (in the directions indicated by arrows L and R). [0076] Further, the border line between the unvulcanized rubber A and the unvulcanized rubber B in the unvulcanized rubber member 19 can also be changed by extrusion pressure of each unvulcanized rubber. [0077] Thus, the use of the unvulcanized rubber extruding apparatus 10 of the present embodiment allows formation of the unvulcanized rubber member 19 shown in the cross section of FIG. 3 in one process. Further, unlike conventional, the unvulcanized rubber member 19 does not have a stepped portion formed by sticking a rubber sheet onto the surface thereof. Therefore, there is no possibility of bare occurring. [0078] As described above, the method and apparatus for extruding unvulcanized rubber according to the present invention has an excellent effect in that the number of processes for manufacturing tires is not increased and an unvulcanized rubber member from which a high quality tire can be obtained can be effectively produced.

A method and apparatus for extruding unvulcanized rubber in a tire production process, in which an unvulcanized rubber extruded member can be formed by extrusion. An extruded rubber member having a cross section in which a portion of a second unvulcanized rubber intrudes between portions of a first unvulcanized rubber is formed by extrusion. The apparatus includes a first passage for the first unvulcanized rubber, a second passage for the second unvulcanized rubber, and a flow dividing mechanism where the first and second passages are adjacent or connected, which separates a portion of the first unvulcanized rubber passing through the first passage such that the first unvulcanized rubber is disposed at both sides of the intruded second unvulcanized rubber. In the method, the first unvulcanized rubber is divided into two flows, and a portion of the second unvulcanized rubber is caused to intrude therebetween.

CONSTRUCTION TOY KIT This is a continuation of application Ser. No. 08/268,537, filed Jul. 6, 1994, now abandoned. This is also related to the following applications all filed on Jul. 6, 1994: Ser. No. 08/267.925, now U.S. Pat. No. 5,454,746 (identified by docket no. 8074-003); Ser. No. 29/025,820 (identified by docket no. 8074-005) now U.S. Pat. No. D380786; Ser. No. 29/025,818 (identified by docket no. 8074-011) now abandoned; Ser. No. 29/025,817 (identified by docket no. 8074-012) now U.S. Pat. No. D386545; TECHNICAL FIELD The present invention relates to a construction toy kit having a plurality of construction elements adapted for constructing various types of structures. BACKGROUND Construction toys for constructing various types of structures generally are packaged in a kit form. A construction toy kit can have a variety of structural components, fasteners, and accessories. Toy construction elements are typically made of a relatively elongated rigid flat plates of various lengths and/or sizes. For instance, metal ERECTOR construction sets made by MECCANO, Inc. and construction sets disclosed in U.S. Pat. Nos. 1,860,627 issued to Sherman; 1,779,826 to Potter and 810,148 to Hornby use flat metal construction plates of various shapes and/or sizes. The plates are assembled or connected together using bolts and nuts or bolt-less types of fastening means. U.S. Pat. No. 1,860,627 also features a circular radiating rib or tooth-like embossment positioned around fastening holes. U.S. Pat. No. 1,724,470 issued to Gilbert further discloses elongated plate like construction elements having perforations and mounting slots. Construction elements can also be made of other materials as wood, plastic materials or the like to reduce the weight and cost. ERECTOR Junior SET construction kits made by MECCANO, Inc, U.S. Pat. Nos. 3,355,837 issued to Pederson and 2,577,702 to Swart disclose such toy construction elements which can be made of plastic materials. Construction kits can even have elaborate mechanical mechanisms incorporating electrical motors and gears for driving, as disclosed for example in Metal ERECTOR construction sets made by MECCANO, Inc. and U.S. Pat. No. 1,164,686 issued to Gilbert. Hand tools such as a screwdriver and a wrench are generally used to tighten or loosen fasteners such as screws, bolts, nuts, etc, which can be used with the construction toy kits described above. A screwdriver typically has a shank extending from a handle, with the end of the shank having a driver member integrally formed therewith or connected thereto. The driver member is shaped to engage a fastener and impart a rotational force thereto. For example, U.S. Pat. No. Des. 341,172 issued to Olsen shows a toy tool having a triangular shaped driver member formed on the end of a shank. U.S. Pat. Des. No. 265,544 issued to Nelson shows a screwdriver having a female figurine shaped handle. U.S. Pat. Nos. 3,173,462 issued to Koeppel and 4,551,110 issued to Selvage et al disclose a typical hand operated screwdriver having a driver member consisting of a flat blade integrally formed on the end of the shank. Hand tools can be included in the toy construction kit. However, they are merely used to tighten or loosen fasteners used with a toy construction kit. They generally serve no other purpose other than during assembly and disassembly of the construction elements. It would be advantageous for the toy kit to include a construction element that can serve as a hand tool. Many different types of containers have been devised for storing or displaying toys or components of a toy construction kit, as disclosed for example in U.S. Pat. Nos. 5,250,000 issued to Boutin et al; 5,172,806 to Mickelberg; 5,035,324 to Bertrand; 5,007,636 to Pagani; 4,872,410 to Lilly; 1,804,927 to Gilbert. These containers are generally formed of a box-like or cylindrical configuration and sized to hold components therein. However, in order to retain all components in the container, the size must be made sufficiently large. Thus, it would be desirable to reduce the overall size of the container while still retaining all component parts therein. SUMMARY OF THE INVENTION The present invention is drawn to a toy construction kit comprising a plurality of construction elements and fasteners for connecting the elements and constructing various forms of toy structures. The construction elements comprise a pair of substantially parallel opposed surfaces and with at least two lateral sides. Each element has at least two spaced mounting holes of a predetermined diameter with an elongated slot formed between adjacent mounting holes. The elongated slot is substantially parallel to an imaginary line extending through centers of the two adjacent mounting holes or parallel to one of the lateral sides thereof. The slots are preferably all of the same size, the width thereof being substantially smaller than the diameter of the mounting hole and the length thereof being about the same or slightly larger than the diameter of the mounting hole. An embossment is formed concentrically around each mounting hole on each of the opposed surfaces. The embossment is a circular raised boss having a textured sandpaper like or roughened surface texture. The elements comprise at least one elongated straight flat strip. Each elongated flat strip preferably has same thickness and width, with a pair of parallel longitudinal sides and rounded ends. It is also preferable to include straight flat strips of various lengths in the kit. Each of the flat strips has a pair of opposed parallel surfaces through which a plurality of equally spaced mounting holes are formed. The embossment is formed concentrically around each mounting hole on both surfaces thereof. The fasteners are adapted to fit in the holes in the construction elements and hold the construction elements together. The slot is also provided between each of the adjacent mounting holes. The elements may further include angled flat strips of various shapes such as A-shape, L-shape, T-shape and C-shape, utilizing the above-described mounting hole, embossment and slot features of the flat straight strip. Specifically, the flat angled strip is formed by a pair of elongated leg strips integrally joined at right angles, with one mounting hole formed at each junction or vertex of the leg strips to form the L-shaped and T-shaped angled flat strips. Each of the leg strips is substantially similar to the flat elongated strip. A third leg strip joined at right angles to a free end of one of the two leg strips can also be included to form an angled bracket having the C-shape. Similarly, many leg strips can be joined to the free ends of the legs strips to form various other configurations. The elements further include plates of various geometric configurations such a triangle and a square. Similar to the straight flat strip element, each of the plates has a pair of opposed parallel surfaces and at least three sides. The plate also utilizes the above-described mounting hole, embossment and slot features of the flat straight and angled strips. Each of the slots extends parallel to one of the sides of the triangle or square. Specifically, the triangular plate would have at least three mounting holes, one formed at each of the three vertexes. The triangular plate has at least three elongated slots, each formed between two adjacent mounting holes. The mounting holes extend parallel to one of the three sides. Each of the slots is parallel to one of the three sides. Preferably, the triangular plate forms an equilateral triangle. The square plate preferably has at least four mounting holes, one formed at each of the four vertexes. The square plate has at least four elongates slots, each formed between two adjacent mounting holes. Moreover, the square plate preferably has a mounting hole formed at its center, but without any embossment formed therearound. Similarly, the plate can form a polygon of any other shape utilizing the mounting holes, slots, embossments described above. The construction elements according to the present invention can further include a plurality of angled strip brackets having an L-shape or C-shape utilizing the above-described mounting hole and embossment features of the flat straight strip. However, it is preferable to include embossments just on the outer side of the angled strips of these brackets. Each inner side is preferably provided with a nut recess so sized to hold a fastener such as a nut in a predetermined position to prevent the nut from rotating when tightening or loosening a bolt or screw that mates with the nut. Specifically, the angular bracket comprises a pair of legs joined at right angles to form an L-shape. The bracket has an outer side and an inner side substantially parallel to the outer side. At least one mounting hole is formed through each leg with an embossment formed concentric around each mounting hole on the outer side. The recess is formed on the inner side of each leg, which extends from a free end thereof toward the junction of the legs. The angular bracket can further include three angled legs, with a pair thereof joined to the ends of a third leg at right angles to form a U-shape. Again, at least one mounting hole is formed through each of the pair of legs and at least two mounting holes formed through the third leg. The embossment is formed concentric around each of the mounting holes on the outer side. A recess is formed on the inner side of each of the pair of legs, each recess extending from a free end thereof toward the junction of the third leg. The recess formed on the inner side of the third leg is rectangular sized to seat at least two fasteners. Alternatively, a plurality of square recess can be formed on the legs, each for seating one fastener. The third leg can also have a flange extending perpendicular to the pair of legs. The flange also has at least two spaced mounting holes with the embossment formed concentric around each mounting hole on the outer side. The construction elements according to the present invention can further include hollow blocks of various configuration, formed by walls connected at an angle with at least one open side. Certain of the walls are provided with mounting holes, embossments on the outer side thereof and recesses on the inner side thereof as described above with respect to the angled strip brackets. Furthermore, the blocks can have additional features such as raised mounting and aligning areas which are generally concentric with the mounting holes to permit stacking of the blocks. Specifically, the block can have at least four walls with an opening to access the inner side thereof. At least three of the side walls each have at least one mounting hole with the embossment formed concentrically therearound on the outer side. A circular recess having a larger diameter than the mounting hole, but smaller diameter than the embossment is formed on the outer side of each mounting hole. Each mounting hole is provided with the recess on the inner side for seating a fastener. More specifically, the block can form a cube having four side walls, a top wall, and an open bottom, each of the four side walls and the top wall having a mounting hole with the embossment and the circular recess on the outer side, and the recess for seating a fastener on the inner side. The construction elements can further include a rectangular block which in essence is two or three of the cubic blocks joined side-by-side with a pair of common opposed side walls, with each of the pair of opposed side walls and the top wall having at least two mounting holes. The construction elements can further include a rectangular block having each of its four side walls with two mounting holes and its top wall with at least four mounting holes. Preferably, the top wall has another mounting hole formed at its center. The construction elements can further include a sloped block having four side walls, a top wall, and an open bottom, with only the three of the four side walls and the top wall each having at least two mounting holes. The side wall without the mounting hole is preferably sloped. The construction elements can further include a curved block having four side walls and an open bottom, with one of the side walls being curved. The other three side walls each have at least three mounting holes. The construction elements can further include a cab block having two opposed side walls joined by a bottom wall, a back wall and a front curved wall, with the front wall extending upwardly only partially, leaving a substantially open front wall. Each of the side, back, bottom walls has at least two mounting holes. The cab block can additionally include a pivotally and removably connected windshield to cover the substantially open front wall. A circular collar extends upwardly from the center of the bottom wall thereof, which is dimensioned to seat or receive other elements. The construction elements according to the present invention can further include accessories such as an axle rod having a plurality of evenly spaced curved notches formed along its axial or longitudinal direction. Specifically, the axle rod has at least one longitudinal channel extending the entire length thereof. A row of notches are formed within each channel. Preferably, a pair of diametrically opposed channels extend the entire length of the axle rod, with the row of notches formed within each channel. The axle rod is substantially circular so to permit the a rotatable connection with a wheel, pulley, or crank. A locking clip having at least one tab is used to maintain any attached wheel and/or pulley from axially moving. Specifically, the notches have peaks and valleys cooperating with the tab to frictionally interlock the locking clip at a desired position relative to the axle rod. Similarly, the crank has a substantially elongated body, a handle rotatably connected thereto and an opening in the body dimensioned to permit the axle rod to be inserted thereinto. The crank has at least one tab that cooperates with the notches formed on the axle rod to interlock the crank to the axle rod. The channel and the tab prevent relative rotational movement between the axle rod and the locking clip, as well as the crank. Preferably, each of the locking clip and the crank has a pair of opposed tabs for engaging with the axle rod with preferred pair of channels. Specifically, each of the tabs extends substantially radially into the central opening formed through the locking clip and the crank opening, the tabs cooperating with the peaks and valleys to lock them relative to the axle rod. The construction elements can further include a connection pin which snaps into the mounting hole formed in the block to connect the blocks to each other. The connection pin comprises a substantially elongated tube, with a portion of the tube having an outer diameter substantially same as that of the mounting hole formed in the block. A central circular flange is formed concentrically with the tube and centrally of the portion. A ridge having a larger diameter than the mounting hole formed in the block is formed adjacent the central flange on either side thereof. There is a spacing between the flange each of the ridges which is about the thickness of the wall of the block at the area of the circular recess to permit the connection pin to snap fit into the mounting hole. A pair of diametrically opposed slots extend along the longitudinal or axial direction of the tube. Each of the slots extends from its free end toward the opposite end, the length thereof being greater than about three-quarter of the total length of the tube, with one slot extending from one end toward the other end and the other slot extending from the other end toward the one end. The diameter of the circular flange is substantially equal to or slightly less than the circular recess formed concentrically around the mounting hole. The thickness of the flange is greater than but no greater than twice the depth of the circular recess to permit the flange to be seated flush in the circular recess. The construction elements can further include a base platform on which the construction elements can be attached to. Specifically, the base platform has a plurality of holes with recessed upper areas sized and shaped to receive fastening nuts. More specifically, the platform has a plurality of rows of uniformly spaced upper recesses each having a concentric mounting hole dimensioned for accepting a fastener. In between adjacent rows of the upper recesses, the platform has a row of uniformly spaced mounting holes each dimensioned also for accepting the fastener. Four legs preferably extend downwardly from the underside of the platform. Another feature of according to the present invention is that the base platform can also be used lock a container which stores the elements. In particular, the container according to the present invention for storing the construction elements has a main body shaped in the form of a box with an open top, four side walls and a bottom. The open top is provided with a pivotable closure which may be maintained in a closed position using the base platform. The closure includes means for receiving the base platform, while the base platform includes means for engaging the closure to retain the container in a closed position. The base platform receiving means comprises four holes while the base plate engaging means comprises the four legs extending from the base platform. More specifically, the closure comprises a pair of flap members pivotally connected to the main body and pivotable between an open position in which the flap members are pivoted away from each other and a closed position in which the flap members are pivoted toward each other. Each of the flap members define a generally flat supporting upper surface with two leg holes and a pair of opposed side extensions extending downwardly from the opposite ends of the upper surface. The opposed side extensions of each of the flap members are pivotally connected to the same opposite side walls of the main body. When the flap members are in the closed position the upper surfaces of the two flap members are generally co-planar. The leg holes formed in the flap members are aligned with the legs when they are closed to permit the legs to pass therethrough and permit the base platform to engage the upper surfaces of the flap members. The base platform accordingly interlocks the flap members and the container in a closed position. Preferably, a handle is provided for the container. The handle may be slideably and pivotally attached to the opposite side walls of the main body of the container. The base platform is preferably provided with a longitudinal recess for receiving the handle. A construction kit according to the present invention can further include a hand held toy tool which can serve a secondary toy function. The tool according to the present invention comprises a longitudinal shank connected to a handle. The shank is substantially circular and has a dimension smaller than the diameter of the mounting hole of the elements to permit the shank to pass therethrough. A driver member is formed on the free end of the shank. The tool further has a cap adapted to completely cover the shank and the driver member and engage the handle. When the cap is engaged with the handle, they form a human-like figure which can be used as a part of a construction toy. Specifically, the handle is shaped as a lower half of a human figure, i.e., the leg portion, whereas the cap is shaped as an upper half of a human figure, including a head portion. The cap and the handle together complete a human-like figure. The cap comprises a longitudinal chamber dimensioned to permit the shank to pass therethrough. The head portion of the cap is hollow and is provided with a shank engaging portion dimensioned to frictionally engage the shank such that the cap is maintained in position relative to the handle portion when engaged. The handle is provided with an alignment projection that cooperates with a hole formed on the cap to correctly align the lower body (handle) with the upper body (cap). According to the toy tool of the present invention, the driver member preferably has a triangular shaped cross-section for driving a fastener with a triangular recess. The tool can have a removably connectable extension driver member. The extension driver member mates with the driver member and is provided with a substantially identical driver member and/or other types of driver members for a quick interchageability. Advantageously, the cap has a circular recess formed at its lower end which is so dimensioned to frictionally fit over the fastener such that it can be lockingly attached to the structure formed by the kit. The fastener according to the present invention preferably comprises a square nut and a bolt comprising a threaded shank and an enlarged circular head. The mounting hole is dimensioned to receive the threaded shank. The circular recess formed at the cap is dimensioned to frictionally seat the head of the bolt. Moreover, the circular collar formed on the cab block has a diameter substantially identical to the diameter of the bolt head such that the cap also frictionally seats on the cab block circular collar. Each of the recesses formed on the brackets and the blocks is dimensioned to seat the nut and maintain it in a predetermined substantially fixed position. That is, the recess prevents the nut from rotating during tightening and loosening of the bolt. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present invention will become much more apparent from the following description, appended claims, and accompanying drawings where: FIG. 1 is a perspective view of a container for storing the components of a toy kit according to the present invention, showing a pair of flap members in their closed position with a base platform disposed thereon. FIG. 2 is a perspective view of the container of FIG. 1 showing the flap members in a partial open position with the base platform removed. FIG. 3 is a perspective view of the container of FIG. 1 shown with the flap members in the closed position, the handle pivoted to the side and the base platform aligned with the flap members for insertion. FIG. 4 is a perspective view of a screwdriver according to the present invention, with the cap and handle engaged to form a human-like figure, and a separate extension. FIG. 5 is a perspective view similar to FIG. 4, with the cap removed to show the shank and the driver member. FIG. 6 is a perspective view similar to FIG. 5, with the extension attached to the driver member. FIG. 7 is a front sectional view of FIG. 4, showing the cap engaged with the handle and the shank thereof. FIG. 8 is a perspective view of a straight flat strip according to the present invention. FIG. 9 is a perspective view of an flat L-shaped strip according to the present invention. FIG. 10 is a perspective view of a flat T-shaped strip according to the present invention. FIG. 11 is a perspective view of a flat A-shaped strip according to the present invention. FIG. 12 is a perspective view of a flat C-shaped strip according to the present invention. FIG. 13 is a perspective view of a triangular plate of according to the present invention. FIG. 14 is a perspective view of a square plate according to the present invention. FIGS. 15A and 15B are perspective views of an angled bracket according to the present invention. FIG. 16A is a perspective view of a double angled bracket according to the present invention. FIG. 16B is a bottom view of FIG. 16A. FIG. 17A is a perspective view of a flanged double angled bracket according to the present invention. FIG. 17B is a bottom view of FIG. 17A. FIGS. 18A and 18B are perspective views of a cubical block according to the present invention. FIG. 18C is a top elevational view of FIG. 18B. FIGS. 19A and 19B are perspective views of a double cubical block according to the present invention. FIG. 19C is a top elevational view of FIG. 19B. FIGS. 20A and 20B are perspective views of a rectangular block according to the present invention. FIG. 20C is a top elevational view of FIG. 20B. FIGS. 21A and 21B are perspective views of an angled block according to the present invention. FIG. 21C is a top elevational view of FIG. 21B. FIGS. 22A and 22B are perspective views of a curved block according to the present invention. FIG. 22C is a top elevational view of FIG. 22B. FIG. 23A is a perspective view of a curved cabin block according to the present invention with a windshield in a partially opened position. FIG. 23B is a side view of FIG. 23A with the windshield in a partially opened position. FIGS. 23C and 23D are perspective views of the curved cabin block with the windshield detached. FIG. 24A is a fastener comprising a bolt and a nut according to the present invention. FIG. 24B is a variation of the bolt shown in FIG. 24A. FIG. 25A is a perspective view of an axle rod according to the present invention. FIG. 25B is a top elevational view of FIG. 25A. FIG. 25C is a partial cross-sectional view taken along line 25C--25C of FIG. 25B. FIGS. 26A and 26B are perspective views of a wheel according to the present invention. FIGS. 27A and 27B are perspective views of a tire according to the present invention. FIG. 28 is a perspective view of a pulley according to the present invention. FIG. 29 is a perspective view of a spacer according to the present invention. FIG. 30 is a perspective view of a washer according to the present invention. FIG. 31A is a perspective view of a locking clip according to the present invention. FIG. 31B is a cross-sectional view taken along line 31B--31B of FIG. 31A. FIG. 32A is a perspective view of a crank according to the present invention; FIG. 32B is a cross-sectional view taken along line 32B--32B of FIG. 32A with the handle thereof detached. FIG. 32C is a perspective view of the handle of FIG. 32A. FIG. 33A is a perspective view of a locking pin connector according to the present invention. FIG. 33B is a bottom elevational view of FIG. 33A, the top elevational view thereof being identical but mirror image of the bottom view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Although reference herein is made to directions such as front, rear, top, bottom, side, they are made merely with respect to the drawings illustrated in the Figs. Such reference is simply for the sake of convenience of description and is not intended to limit the present invention in structure or operation in any way, manner or form. FIGS. 1-3 show the container 1 according to the present invention for storing the construction kit. The container has a main body 2 preferably in the form of either a square or rectangular box having a bottom, four side walls and an open top. The container includes a closure 3, a separate planar base platform 4 and a handle 5. For purposes of the following description, left/right side walls of the main body 2 have been referred to as side walls 7, and front/rear side walls as side walls 6. The closure comprises a pair of flap members 3 pivotally connected to the side walls 7 of the main body 2 and pivotable between an open position in which the flap members are pivoted away from each other and a closed position as shown in FIGS. 1 and 3 in which the flap members are pivoted toward each other. FIG. 2 shows the flap members in a partially open position. In the complete open position, the flap members are preferably pivoted away from each other to completely expose the open top for easy access to the opening. As better shown in FIGS. 2 and 3, the two flap members are mirror images of each other. Each of the flap members is defined by a generally flat recessed planar upper surface 34 with at least one hole 35, two holes being preferred as shown in FIGS. 2 and 3, and a pair of opposed side extensions 33 extending preferably substantially perpendicularly from the opposite ends of the upper surface 34. Each of the opposed side extensions is preferably substantially planar and preferably has a right-triangular pattern. A reinforcement 38 in the form of a strip, preferably of a plastic material, is formed on each of the hypotenuse sides thereof. Each of the lower vertex of the side 33 is pivotally connected to one of the opposite side walls 7 of the box, preferably using a plastic bolt 8 and a nut (see FIGS. 24A and 24B). When the flap members are in the closed position the upper surfaces of the two flap members are generally co-planar as shown in FIG. 3. The outer periphery 36 of each of the upper surfaces 34 is preferably provided with a pair of opposed recesses 37 at the ends thereof to receive the handle 5. The depth of the recesses are such that the handle sits substantially flush with the outer periphery 36 of the upper surface 34 when the handle is retracted downward. As shown in FIG. 3, each of the free edge of the recessed upper surface 34 is provided with a cut-out, with both cut-outs forming an elongated oval shape for permitting insertion of fingers or an implement for lifting the flap members open. The base platform 4 comprises a planar base plate 41 corresponding to the shape and size of the recessed upper surfaces 34 when they are co-planar, preferably either square or rectangular, corresponding to the box configuration. The base plate is provided with at least two legs 42 extending perpendicularly therefrom, the total number of the legs being less than or equal to the openings formed in the upper surfaces 34. The holes formed in the planar surfaces are aligned with the legs to permit the legs to pass therethrough and permit the platform 4 to sit flush on the upper surfaces of the flap members. The holes may be sized to be slightly larger than the legs so that the legs easily pass therethrough. Alternatively, the legs can be provided with an end portion which snap-locks the legs into the holes. Further, the legs can be sized to frictionally engage the inner diameters of the holes to secure the platform. If desired, the legs may be configured with a first portion that has a smaller diameter than the hole and a second portion which progressively frictionally engages the hole to secure the legs therein. Of course, when used, not all legs and holes need to have these locking features, as only one is sufficient. Advantageously, the platform 4 interlocks with the flap members to securely retain them in a closed position. As shown, the platform 4 preferably has four legs 42, corresponding to four holes formed on the upper surfaces 34 of the flap members. The platform 4 is a component of the construction kit itself and includes a plurality of recessed areas 46 with mounting holes sized and shaped to receive fastening nuts. More specifically, the platform has a plurality of rows of uniformly spaced upper recesses 46 each having a concentric mounting hole 47 dimensioned for accepting a fastening bolt. In between the adjacent rows of the upper recesses, the platform includes a row of uniformly spaced mounting holes 48 having a same dimension as the mounting hole 47 also for accepting the fastening bolt. The base plate preferably includes a central longitudinal recess 43, shown in FIG. 2, for receiving the handle 5 when the container 1 is in the closed position and the handle retracted down, as shown in FIG. 1. Moreover, the base plate preferably further includes a pair of opposed cut-outs 44 formed at the opposite sides and underneath thereof, parallel to the handle 5 to permit insertion of fingers or an implement to facilitate removal of the platform 4 from the flap members 3. Preferably, the handle 5 is slideably and pivotally attached to the opposite side walls 7 of the box container. The longitudinal recess 43 receives the handle when it is retracted down. The handle also serves to maintain the platform in place. The handle is preferably U-shaped with a flat intermediate portion 51 and a pair of vertical segments 52 extending from opposite ends thereof. The vertical segments 52 of the handle are slideably and pivotally disposed on the vertical slots 9 formed at the opposite side walls 7 of the box. Although not shown, each of the vertical segments are provided with a pin or like that extends through the slot. The handle can be raised up and pressed down in the direction of a double arrow A as shown in FIG. 2 and pivotable as well in the direction of a double arrow B as shown in FIG. 3 to facilitate insertion and removal of the platform and to provide easy access to the inside of the container. Although the closure and platform are preferably engaged using the legs and holes as described above, it will be apparent to one of ordinary skill in the art that many other means can be used to achieve this engagement. For example, the platform receiving means of the closure and the closure engaging means of the platform can be formed of any components that can be connected or attached. For example, one could be of the hook material of a hook and loop fastener (i.e., VELCRO), while the other can be made of the loop material. One could instead be the protruding portion of a snap connector, while the other is the recess portion of the connector. More elaborate interlocking members can be used, if desired. The main purpose of these means is to removably secure the platform to the closure. The main body or box, the flap members, and handle can be made of any suitable material, such as a cardboard, plastics, and metal. However, it is preferable to form the flap members, the handle and the platform of a plastic material for durability. FIG. 4 shows a perspective view of a human-like figure shaped toy tool 10 according to the present invention, with a separate driver extension 80. The tool 10 comprises a handle 70 that is shaped as a lower half a human figure, i.e., the leg portion, and a cap 60 that is shaped as an upper half of a human figure, including a head. The handle 70 together with the cap 60 completes a human-like figure. FIG. 5 is shown with the cap 60 detached from the handle 70 to show the handle in its entirety. Specifically, a longitudinal shank 90 extends from an end 72 of the handle. The end 72 is preferably substantially flat. The shank 90 is fixedly connected to the handle or integrally formed therewith so that there is no relative rotative movement between the shank and the handle. The diameter of the shank is substantially same as that of an axle rod 340 so that it can pass through a mounting hole 104 formed on the construction elements. A driver member 92 extends substantially collinearly with the longitudinal axis of the shank. The driver member preferably is integrally formed with the shank and has a triangular cross-section for engaging a complementary triangular shaped recess formed in the fastener. However, the driver member could have any other geometric configuration, such as a hexagon (allen wrench), star (torx wrench) or square, either as a relief or recess configuration, or as a conventional phillips or flat head configuration. Moreover, different types of driver member configurations can be readily attached to the driver member 92 in the form of a driver extension. Specifically, although one extension 80 is shown with a same triangular geometric configuration driver member 82 as the driver member 92, the driver member 82 can be of any other geometric configuration mentioned above. Accordingly, different types of driver members can be readily provided as desired by merely changing the extension. The other end of the extension 80 has a recess 84 complementary to the geometric shape of the driver member 92, i.e., a triangular recess for the triangular driver member 92. FIG. 6 shows the extension 80 inserted over the driver member 92. The extension also permits the tool to reach into deeper or recessed areas by increasing the overall working length of the shank. As more clearly shown in FIG. 7, the cap 60 comprises has a head shaped member 62 connected to a body 61. The head shaped member 62 is preferably rotatably connected to the upper end of the body. As shown in FIGS. 6 and 7, the lower end 64 of the body is substantially flat so that it can stand upright on a flat surface and is provided with a circular recess 68. The lower end or foot 78 of the handle is also preferably formed flat so that the tool 10 can stand upright on a flat surface. The flat end 72 of the handle engages with the flat end 64 of the body 61 as shown in FIG. 7. The flat end 72 of the handle is provided with an alignment projection 74 for engaging a complementary alignment hole 66 formed on the flat end of the body 61. The projection 74 helps to align the lower body 70 with the upper body 60 to complete the human-like figure. The projection 74 also prevents the cap 60 from rotating relative to the handle 70. The flat end 72 of the handle is preferably provided with a collar 76 of a predetermined diameter corresponding to the circular recess 68 formed in the flat end of the body 61. The collar 76 engages the recess 68 when the cap 60 is pulled over the shank to permit a frictional engagement. Also, the collar 76 cooperates with the alignment projection 74 and the alignment hole 66 to maintain a proper human-like configuration when the cap is engaged with the handle as shown in FIGS. 1 and 4. As shown in FIG. 7, the head shaped member 22 is preferably hollow to permit insertion of a portion of the shank 90 which is preferably substantially cylindrical and the entire driver member 92. The head shaped member has an integral cylindrical neck portion 65 that extends into an opening formed in the upper end of the body. The neck portion is frictionally engaged to the body to permit rotation of the head member relative to the body. The neck portion is provided with a one-way snap fit tapered circular ridge 67 that has a larger diameter than the opening occupied by the neck portion. The tapering shape of the ridge permits insertion into the body, but is made difficult for removal in the opposite direction. Specifically, the cylindrical neck portion is provided with at least a pair of diametrically opposed vertical slots (not shown) to permit the diameter of the neck portion to decrease when pushed into the opening formed in the upper end of the body, but returned to its normal dimension once the neck portion is placed into the opening. The ridge, however, permits removal of the head shaped member from the body when pulled with enough force. The inner diameter of the neck portion is preferably dimensioned to frictionally engage the shank so that it can maintain the cap in its place relative to the handle. The toy tool according to the present invention has a separate utility other than as a tool. Specifically, with the cap in its place relative to the handle, the human-like figure can be used as a part of a construction kit. In particular, in a toy construction kit, either just the cap or the entire human-like configured tool can be placed as a driver of a car, a pilot of a plane or an engineer of a train, etc. Particularly, the recess 68 is dimensioned such that it frictionally fits over the circular bolt head 312 (FIGS. 24A and 24B). More particularly, the bolt head protrudes from the surface of the component being connected therewith. The cap 60 may then be placed over the bolt head. The frictional engagement therewith maintains the cap relative to the bolt head. Moreover, the foot 78 or the recess 68 of the cap can be used to stably interfit or connect with a complementary fittings formed on the components of the construction kit as described below with respect to the cabinet block 250 shown in FIGS. 23A, 23B, 23C, 23D. The entire hand tool can be made of any suitable plastic, wood or metal. However, it is preferable to form the hand tool from plastic materials such as ABS, nylon, etc. The construction elements of the construction kit according to the present invention further comprises a plurality of flat straight strips 100 of various lengths; various angled strips of L-shape 110, T-shape 120, A-shape 130, and C-shape 140; plates 150 and 160 of various shapes such as triangular and square as shown in FIGS. 8-14. With respect to the construction elements 100, 110, 120, 130, 140, 150 and 160, their opposed top and bottom sides 102, 112, 122, 132, 142, 152 and 162 are substantially flat, parallel and identical. These elements all have a same thickness. All of these elements also have at least two spaced mounting holes 104 of same diameter and spacing. Each mounting hole is dimensioned to accept the bolt 310. A pair of circular embossments or raised bosses 106 are formed concentrically around each mounting hole 104, one on each side 102 thereof. The embossments are slightly raised from the flat surfaces of the top and bottom sides 102. In particular, each of the embossments are raised about 0.1 mm thick and have a roughened surface texture, akin to that of a sandpaper, to enhance friction. However, the embossments can be made thicker as desired and with different textures or roughness. The bosses can also be made of different shapes, such as a rectangle and can be formed through any conventional plastic molding process. Each of these elements further comprise at least one elongated slot 108 arranged between the two adjacent mounting holes 104. Moreover, each of the angled corners 109, 119, 129, 139, 149, 159 and 169 joined at right angles is preferably contoured smooth or beveled to remove any sharp edge. FIG. 8 shows a straight flat strip 100 having a pair of flat opposed parallel sides 102 having a uniform width and thickness. The flat strip 100 has at least two spaced mounting holes 104 and embossments 106 discussed above arranged along the longitudinal direction thereof. Any number of mounting holes can be can be provided, thus providing strips 100 of different lengths. FIG. 9 shows a flat L-shaped or corner strip 110 according to the present invention. The flat L-shaped strip 110 has a pair of opposed parallel flat surfaces 112 on which the embossments 106 are formed. The strip 110 has a pair of legs 114, 116 joined at right angles to form an L-shape. At least three mounting holes 104 are formed as shown in FIG. 9, with one mounting hole formed at the vertex of the legs. Each of the two legs is similar to the elongated flat strip 100. FIG. 10 shows a flat T-shaped strip 120 according to the present invention. The flat T-shaped strip 120 has a pair of opposed parallel flat surfaces 122 on which the embossments 106 are formed. The strip 120 has a pair of legs 124, 126 joined at right angles to form a T-shape. At least four mounting holes 104 are formed, with one mounting hole formed at the vertex of the legs. Each of the two legs is similar to the elongated flat strip 100. With respect to the elements of FIGS. 8-10, any number greater than equal to the minimum number of mounting holes suggested above can be provided to form different length strips 100 as shown by the phantom lines. Similarly, each leg of the angled strips 110 and 120 can be provided with any number of mounting holes to form various lengths as shown by the phantom lines. However, the spacing between two adjacent mounting holes is uniform throughout or multiples thereof. Furthermore, each of the ends of the strips 100, 110, 120 is preferably rounded as shown by the solid lines. FIGS. 11 and 12 show flat angled brackets 130 and 140 of various configuration according to the present invention. The flat bracket 130 has a pair of opposed parallel surfaces 132 on which the embossments 106 are formed, and a pair of identical legs 134 joined at right angles similar to the L-shaped bracket shown in FIG. 9. A relatively thin reinforcement 138 spans across the legs to form an A-shaped bracket 130. Each of the two legs is similar to the elongated flat strip 100, with the same spacing between two adjacent mounting holes 104. At least five mounting holes are formed in the flat bracket 130. The flat bracket 140 shown in FIG. 12 has a pair of opposed parallel surfaces 142 on which the embossments 106 are formed and three legs 144 and 146. A pair of identical legs 144 are each joined at right angles to the ends of the leg 146 in a same plane, forming a C-shape or U-shape. Each of the three legs is similar to the elongated flat strip 100, with the same spacing between two adjacent mounting holes 104. At least six mounting holes are formed in the flat bracket 140, with one mounting hole formed at each vertex of the legs. FIGS. 13 and 14 show plates 150 and 160 of various geometric configuration according to the present invention. The plate 150 has a pair of flat opposed parallel surfaces 152 on which the embossments 106 are formed. The plate 150 forms an isosceles triangle with three identical corners 151 and three mounting holes, one mounting hole 104 being arranged at each of the corners. Each of elongated slots 108 is formed parallel to one of the sides thereof. Again, the spacing between two adjacent mounting holes is identical to that of the flat strip 100. The plate 160 has a pair of flat opposed parallel surfaces 162 on which the embossments 106 are formed. The plate 160 forms a square with four identical corners 151 and four mounting holes, one mounting hole 104 being arranged at each of the corners. Each of elongated slots 108 is formed parallel to one of the sides thereof. In addition, another mounting hole 104 is formed centrally of the plate 160, but formed without any embossment 106. Again, the spacing between two adjacent mounting holes with the embossments is identical to that of the flat strip 100. FIGS. 15A, 15B, 16A, 16B, 17A and 17B show angular brackets of various configuration according to the present invention. Each of the angular brackets 170, 180 and 190 has substantially flat outer sides 171, 181, 191 and inner sides 172, 182, 192 substantially parallel to the outer sides thereof. These elements all have a same thickness which is same as that of the straight strip 100. All of these elements also have the same mounting holes 104 and embossments 106 described above with respect to the flat members. However, the embossments 106 are only formed on the outer sides thereof. The spacing between two adjacent mounting holes in the same plane having the embossments 106 is same as that of the straight strip 100. Again, each of the angled corners 179, 189 199 joined at right angles is preferably contoured smooth or beveled to remove any sharp edge. FIGS. 15A and 15B show an angular bracket 170 having a pair of legs 174 and 176 in two different perpendicular planes, joined at right angles to each other to form an L-shape. Each of the legs has at least one mounting hole 104. Each of the inner sides 172 has a longitudinal nut recess 177 extending from a free end thereof into adjacent the junction between the legs, the recess extending past the mounting hole 104. The width of the recess is dimensioned hold the nut 320 at a fixed angular position and concentric with the mounting hole 104. The opposite wall surfaces 177a and 177b formed by the recess prevent the nut 320 (FIGS. 24A and 24B) from rotating when tightening and loosening the bolt 310 that mates with the nut. Although each of the legs is shown with a single mounting hole 104, different number of mounting holes can be provided, thus varying the length thereof. FIGS. 16A and 16B show a doubled angled bracket 180 having a pair of identical legs 184 each joined to the ends of a third leg 186 to form a U-shape or C-shape. Each of the legs 184 is joined at right angles to an end of the leg 186 in a perpendicular plane. Each of the legs has at least one mounting hole 104. Each of the pair of legs 184 has a longitudinal nut recess 187a formed on the inner side thereof, which extends from a free end thereof to adjacent the junction of the legs, the recess extending past the mounting hole 104 formed nearest the junction of the legs. Again, the width of the recess is dimensioned to hold the nut 320 at a fixed angular position and concentric the mounting hole 104. The opposite wall surfaces formed by the recess prevent the nut 320 from rotating when tightening and loosening a bolt 310 that mates with the nut. The leg 186 also has a rectangular nut recess 187b dimensioned to hold the nut at a fixed angular position for each of the three mounting holes formed therein. Alternatively, two square recesses for the outer two holes could be formed similar to the recesses 218 formed on the block 210. The bracket 180 is provided with at least five mounting holes 104. The leg 186 is provided with a central mounting hole 104, but without an embossment on the outer side thereof, as shown in FIG. 16B. Again, the legs 184 can have different lengths as desired as shown by the phantom lines. The flanged double angled bracket 190 shown in FIGS. 17A and 17B are substantially similar to the double angled bracket 180. The bracket 190 has a pair of identical legs 194 joined to the ends of a third leg 196. Each of the legs has a recess 197a, 197b similar to that of the recess 187a, 187b. However, the bracket 190 is provided with a flange 198 extending from the leg 196 in the same plane. Moreover, each of the pair of identical legs 194 has two mounting holes 104, although it can also have just one mounting hole. The flange additionally has three mounting holes with a pair of embossments 106 formed on the two outer holes on the outer side thereof. FIGS. 18A, 18B, 18C, 19A, 19B, 19C, 20A, 20B, 20C show cubical blocks 200, 210, 220 of various configuration. Each of the side walls 202, 212, 214, 222 and top walls 203, 213, 223 has at least one mounting hole 104 of the same size as that of the strip 100. A raised boss or embossment 206 substantially similar to the embossment 106 is concentrically formed around each mounting hole 104 on the outer side 201, 211, 221. The outer diameter and the thickness of the embossment 206 is same as that of the embossment 106. A circular recess 204 larger than the diameter of the mounting hole 104, but smaller than the diameter of the embossment 206 is formed concentrically with the mounting hole 104. Preferably, the diameter of the recess 204 is about one-half the diameter of the embossment 206. The block 200 comprises four identical side walls 202, a top wall 203 and an open bottom. As shown in FIG. 18C, each outer side 201 has a substantially planar raised surface. Each of the inner sides 205 is provided with a nut recess 207 that is substantially similar to the nut recess 177 formed on the angled bracket 170. The inner side of the top wall 203 is provided with a substantially square recess 208 so sized and shaped to receive the square nut 320. Each of the recesses 207, 208 seats the nut and prevents it from being rotated when tightening or loosening the mating bolt. The cubical block 210 shown in FIGS. 19A and 19B in essence is two blocks 200 joined side-by-side with common side walls. The block 210 comprises a pair of identical opposed side walls 212 and another pair of identical opposed side wall 214 each of which is identical to the side wall 202 of the block 200, a top wall 213 and an open bottom. Each outer side 211 of the side walls 212 and the top wall has a pair of substantially planar raised surfaces through which a pair of mounting holes 104 are formed. Each outer side 211 of the walls 214 has a substantially planar raised surface through which one mounting hole 104 is formed. Each of the inner sides 215 of the side walls 214 is provided with a nut recess 217 in association with the mounting hole 104, substantially similar to the nut recess 207 formed on the block 200. Each of the inner sides 215 of the side walls 212 is also provided with a pair of nut recesses 217. The inner side of the top wall 213 is provided with a pair of spaced square recesses 218, each being identical to the recess 208. Alternatively, the inner side of the top wall could be provided with a single rectangular recess similar to recess 187b formed on the angled bracket 180. The spacing between two adjacent mounting holes 104 on the same side wall is identical to the spacing between two adjacent mounting holes 104 of the strip 100. In addition, similar to the block 210, a block (not shown) having three or any other number of blocks 200 joined together with common opposed side walls can be provided as desired. The block 220 comprises four identical side walls 222 which is similar to the side wall 212 of the block 210, a top wall 223 and an open bottom. Each outer side 221 has a substantially planar raised surface as better shown in FIG. 20A. The outer side 221 of the top wall has a five substantially planar raised surfaces through which five mounting holes 104 are formed. The raised surfaces are joined together to form an X-shaped raised surface. The inner side of the top wall 223 is provided with five square nut recesses 228 as better shown in FIG. 20C, each being identical to the recess 208. The spacing between two adjacent mounting holes 104 parallel to the side walls is identical to the spacing between two adjacent mounting holes 104 of the strip 100. FIG. 20B also includes inner sides 225, which are similar to inner sides 215, each provided with a nut recess 227, similar to nut recess 217. FIGS. 21A, 21B, 21C, 22A, 22B, 22C, 23A, 23B, 23C, 23D show angled and curved blocks 230, 240, 250 according to the present invention. Similar to the blocks 200, 210, 220, the blocks 230, 240, 250 have walls with mounting holes 104 of the same size as that of the strip 100. A raised boss or embossment 206 and a circular recess 204 identical to that of the blocks 200, 210, 220 are concentrically formed around each mounting hole 104 on the outer side 231, 241. Moreover, nut recesses 237, 247, 257 and square nut recesses 238, 258 similar to the recesses 207 and 208 are formed on the inner sides thereof. Specifically, the angled block 230 comprises a pair of mirror image side walls 232, a side wall 234, an angled side wall 235, a top wall 233 and an open bottom. Each outer side 221 of the walls 232 has three mounting holes 104, two of which are vertically aligned and two of which are horizontally aligned. The spacing between the horizontally and vertically aligned pairs of mounting holes is same as the spacing between two adjacent mounting holes 104 of the strip 100. The outer side of the top wall has four planar raised surfaces through which four mounting holes 104 are formed therewithin. The outer side of the side wall 234 has two planar raised surfaces through which four mounting holes 104 are formed, two on each thereof. Each of the side walls 232 has one sloped edge 232a on which the side wall 235 is formed. As shown in FIGS. 21B and 21C, each of the inner side of the side walls 232, 234 is provided with two vertical nut recesses 237 similar to the nut recess 207 except that the length of the recesses 237 accommodates at least two nuts. In addition, each of the side walls 232 has another recess 237a. The inner side of the top wall 233 has four square nut recesses 238, each identical to the recess 208. The spacing between two adjacent mounting holes 104 parallel to the side walls is identical to the spacing between two adjacent mounting holes 104 of the strip 100. The curved block 240 comprises a pair of mirror imaged side walls 242, a third side wall 244, a curved top/side wall 243 and an open bottom. Each of the side walls 232 has three mounting holes 104 spaced and arranged identically to the three mounting holes 104 formed on the side walls 232 of the angled block 230. The side wall 244 is substantially identically to the side wall 234 of the angled block, except that the side wall 244 has two additional vertically spaced mounting holes 104 formed through another planar raised surface. Each of the side walls 242 has one curved edge 242a on which the top/side wall 243 is formed. As shown in FIGS. 22B and 22C, each of the inner side of the side walls 242, 244 is provided with two vertical nut recesses 247 similar to the nut recess 237. Specifically, inner side of the side wall 244 has three recesses 247 each for accommodating two nuts. The inner side of the each side wall 242 has one recess 247 for accommodating two nuts and one recess 247a for accommodating one nut. The spacing between two adjacent mounting holes 104 parallel to the side walls is identical to the spacing between two adjacent mounting holes 104 of the strip 100. FIGS. 23A and 23B show a curved cabin block 250 with a windshield 300 connected in a partially opened position according to the present invention. FIGS. 23C and 23D show the curved cabin block 250 with the windshield removed. The cabin block 250 comprises a pair of opposed mirror image side walls 252, a rear wall 254, a curved front wall portion 253, a bottom wall 255 and an open top/side. Each of the side walls 252 has three mounting holes 104 spaced and arranged identical to the three mounting holes 104 formed on the side walls 232 of the blocks 230 and 240. The rear wall 254 has two horizontally spaced mounting holes 104, which is substantially identically to the side wall 222 of the block 200 except that there is no raised planar surfaces other than the embossments formed around each mounting hole 104. The bottom wall 255 is provided with four mounting holes 104 similar to the top wall 233 of the block 230, but without the raised planar surfaces. Each of the side walls 252 has one curved edge 242a on which the side wall 253 is formed. As shown in FIGS. 23A and 23C, each of the inner side of the side walls 252, 254 is provided with two vertical nut recesses 257, 257a. Specifically, the inner side of the side wall 254 has two recesses 257 each for accommodating one nut. The inner side of each side wall 252 has one recess 257 for accommodating one nut and one recess 257a for accommodating two nuts. The inner side of the bottom wall 255 has four square nut recesses 258 identical to the recesses 238 of the block 230. The spacing between two adjacent mounting holes 104 parallel to the side walls is identical to the spacing between two adjacent mounting holes 104 of the strip 100. An upwardly extending cylindrical collar 276 is formed centrally of the bottom wall. The collar 276 cooperates with the recess 68 formed on the body 61 of the hand tool 10. Similar to the collar 76 formed on the handle 70, the collar 276 is so dimensioned to frictionally engage the recess 68 such that the cap can be attached to the bottom wall of the cabin block 250. Each upper side corner of the side walls 252 has a slot 260 to permit a rotatable connection with the windshield. The slot 260 preferably has a smaller opening at its entrance and enlarges toward its end to permit a snap fit of the windshield. The windshield is provided with a pair of outwardly and laterally extending pins 302 which engage the slots 260, and a handle 304 to permit fingers to grab and lift the windshield. The curvature of the windshield is substantially identical to the curvature of the curved free ends of the side walls 252 such that the windshield can fully close even with the cap 60 connected to the cabin block. Moreover, the edges 261 and 262 formed on the inner side of the walls 252 act as limit stops to prevent the windshield from closing too far inwardly. That is, the edges 261 and 262 align the windshield such that it is substantially flush with the curved free edges of the walls 252 when the windshield is fully closed. FIGS. 33A and 33B show a locking pin connector 400 which snap fits in the mounting holes 104 formed concentric with the circular recess 204 in the blocks 200, 210, 220, 230, 240, 250 to connect them together. Specifically, the connector 400 comprises an elongated hollow tube of a uniform inside diameter and varying outer diameters. The cylinder has a pair of diametrically opposed slots 402 extending along its wall in the axial or longitudinal direction thereof. Each of the slots extends from its free end toward the opposite end, the length thereof being greater than about three-quarter of the total length of the cylinder, one slot extending from one end toward the other end and the other slot extending from the other end toward the one end. The first cylinder portion 401 have a dimension smaller than the diameter of the mounting hole 104. Each end has a circular ridge 404 of a greater dimension than the cylinder portion 401, but still smaller than the diameter of the mounting hole 104. The second cylinder portion 405 has a dimension substantially equal to or slightly less than the diameter of the mounting hole 104 to permit a relative rotatable connection therewith. A central circular flange 408 is disposed between the cylinder portion 405. The outer diameter of the flange 408 is substantially equal to or slightly less than the circular recess 204. The thickness of the flange 408 is substantially is greater than but no more than the twice the depth of the recess 204 such that the flange is completely between two recesses 204 when the blocks are connected therewith. Between each of the cylinder portions 401 and the flange 408, a second circular ridge 406 having a slightly larger diameter than the mounting hole 104 is formed. The pin connector snap fits into the mounting hole 104 provided with a circular recess 204, the ridge 406 providing a locking mechanism. The length of each of the portions 405 in the axial direction thereof or the spacing between the flange 408 and each of the ridges 406 is about the thickness of the wall of the block at the area of the circular recess to permit the connection pin to snap fit into the mounting hole. The slots enable the ridge 406 to squeeze through the mounting hole 104 when the pin connector is pushed with a sufficient force, and returns to its normal dimension once the ridge passes therethrough. Each pin connector enables any two blocks to be connected together. Specifically, a pin connector is first connected to one of the two blocks from one end and then another block to be connected is connected through the other end of the pin connector. To disconnect the blocks, the blocks are pulled apart and then the connector is pulled out from the block in which the connector remains attached to. FIGS. 24A and 24B show fasteners 8 and 8' according to the present invention. The fasteners 8 and 8' each comprise a threaded bolt 310 and a square nut 320. The bolt preferably has an Acme screw threading to permit faster nut travel with each turn of the bolt. The bolt 8 has a completely threaded shank whereas the bolt 8' has a partially threaded shank. The non-threaded portion 311 can be used as bearing surface in which parts can be rotatably mounted. Each of the bolts 8, 8' further has a head 312 preferably with a triangular recess 314 which is complementary to the driver members 42 and 52. The head 312 shown in FIG. 24B has a plurality of axially extending grooves 313 which provide a textured gripping surface to enhance friction. Specifically, the bolt can be turned also by grabbing the textured surface of the head. The bolt 310 shown in FIG. 24A also preferably has such textured gripping surface formed on the perimeter of the head 312. The diameter of the head 312 is such that it cooperates with the recess 68 formed in the cap 60 to frictionally engage therewith. The diameter of the nut is about the width or slightly smaller than the width of the recesses 177, 187, 207, 208, 217, 218, 227, 228, 237, 238, 247, 257, 258, the width thereof being uniform. The nut 320 is substantially square with rounded corners which fit within the recesses. The bolt and the nut are preferably formed of conventional plastic material such as polypropylene, ABS or nylon. However, it is preferable to form them with polypropylene, more preferably with 5% fiber glass for strength. FIGS. 25A, 25B and 25C show an axle rod 330 according to the present invention. The axle rod is substantially circular with a pair of opposed mirror image longitudinal channels 331 formed therein. A pair of opposed mirror image rows of evenly spaced curved notches 332 are formed in the channel along the longitudinal or axial direction thereof. The axle rod is substantially circular to permit a rotatable connection with any of the above described elements having a mounting hole 104, wheel 500, pulley 520, spacer 530, and washer 540 shown in FIGS. 26A and 26B, 28, 29 and 30. The axle rod cooperates with a locking clip 340 shown in FIGS. 31A and 31B. The locking clip has a cylindrical or circular configuration with a central opening configured to the cross sectional geometric configuration of the axle rod. The central opening permits the locking clip to move longitudinally of the axle rod but does not permit relative rotational movement therewith. Specifically, it has a mechanical locking mechanism comprising a pair of opposed mirror image tabs 342 formed on the central opening. The tabs occupy the space formed in the channels to thereby prevent a rotational movement about the axle rod. Each tab has a rounded apex 343 forming the narrowest spacing therebetween. The tabs are resiliently hinged so that they can flex in the radial direction. The tabs cooperate with the notches 332 to provide a positive lock along any of the notches to maintain any attached wheel and/or pulley from axially moving. Specifically, the peaks and valleys of the notches cooperate with the apexes of the tabs to frictionally interlock the locking clip at a desired position relative to the axle rod. When the clip is at a locking position, the apexes rest adjacent the valleys or the notches. To move the locking clip longitudinally, some force is necessary to cause the tabs to expand radially. This is achieved by pulling or pushing the clip along the axial direction of the axle rod. When a sufficient force is applied, the curved notches acts as a cam against the curved apexes to radially move the resiliently hinged tabs over the peaks and down to the next valley. Continuous push or pull causes the clip to successively move relative to the axle rod in the axial direction. Moreover, the outer perimeter of the locking clip has a groove 344 for engaging a belt or the like. The locking clip has another function as a driving pulley. The outer perimeter thereof can also have teeth or like to positively rotate a belt with cooperating teeth or the like. FIGS. 32A and 32B show a crank 370 comprising an elongated body 371 having a locking mechanism 380 substantially similar to the locking mechanism of the locking clip formed at one end of the body. Specifically, the locking mechanism 380 has a pair of mirror image opposed tabs 382 that cooperate with the notches 332 formed on the axle rod 330 to interlock the crank. Similar to the tabs 342 of the locking clip, the tabs 382 occupy the channels 331 to prevent relative rotational movement between the axle rod and the crank. Each tab 382 has a rounded apex 383 forming the narrowest spacing therebetween. The tabs are resiliently hinged so that they can flex in the radial direction. The tabs cooperate with the notches 332 to provide a positive lock described above with respect to the locking clip. The crank has a handle 390 that snap fits into the hole 372 formed at the other end of the crank. As better shown in FIG. 32C, the handle has a bearing portion 391 having a diameter slightly less than or substantially the same diameter as the hole 372. A pair of diametrically opposed slots 392 are formed on the bearing portion to enable it to be squeezed during insertion through the hole 372. The bearing portion is provided with a chamfered circular ridge 394 and a limit stop ridge 396. Each of the ridges has a diameter larger than the hole 372. The slots permit the diameter of the ridge to be squeezed during insertion into the body, but returned to its normal dimension once the ridge passes through the hole. The slots, however, permit removal of the handle from the body when pulled with enough force. FIGS. 26A and 26B show a wheel 500 according to the present invention which can be used in conjunction with the axle rod 330, the locking clip 340, the spacer 530, etc. The wheel comprises a cylindrical outer side 502 which is slightly conical and a central opening 508 having a diameter equal to that of the mounting hole 104. The outer side 502 tapers slightly outwardly from the outer face side toward the inner face side of the wheel as shown in the FIGS. 26A. FIG. 26A shows the outer sidewall 504 which extends from the perimeter end of the outer side 502. FIGS. 26B shows the inner face 503 of the wheel which has no side wall extending from the edge of the outer side 502. FIGS. 27A and 27B show a tire 510 according to the present invention. The tire is formed of a resilient material such as plastics and rubber having an inner diameter about the diameter of the outer surface 502 at the junction with the outer face 501. In other words, the inner diameter of the tire has a size of the smallest outer diameter of the wheel. This enables the tire to be stretched over the wheel and frictional held with substantially no relative rotational movement therebetween. FIG. 27A shows the outer sidewall 514 of the tire which extends from the tread portion 512. The sidewall 514 extends toward the center thereof to cover the sidewall 504 of the wheel. FIG. 27B shows the inner sidewall 516 extending from the tread portion. The sidewall 516 extends toward its center to cover the edge 505 of the inner side of the wheel. According to the present invention, different tires can be fitted over the wheel. The tires can be substituted for tires having different treads. FIG. 28 shows a pulley 520 having an groove 522 formed at its outer perimeter similar to the groove 344 formed at the locking clip 340. The pulley has at least a central hole 524 of the same diameter as the mounting hole 104. The pulley can be used in conjunction with the bolt 310 or the axle rod 340 for a rotatable support. Preferably, the pulley has four additional holes 524 of the same diameter as the mounting hole 104. These additional holes can be used to connect additional elements such as another pulley. FIG. 29 shows a spacer 530 having a central hole 534 of the same diameter as the mounting hole 104. The spacer can be used in conjunction with the bolt 310 or the axle rod 340 to provide a spacing between a wheel and the locking clip for instance. FIG. 30 shows a washer 540 having a central hole 544 of the same diameter as the mounting hole 104. The washer can be used either as a smaller spacer or with the bolt to provide a spacing between the element and the bolt head. The washer is preferably made of soft elastic material such as rubber and plastics. It will be understood by one skill in the art from the present disclosure that a number of construction and fastener elements can be combined to form the kit. Also, depending upon the number of same and different components of the kit, structures of infinite variety can be constructed such as air planes, automobiles, boats and ships, cranes, helicopters, trucks etc. In this regard, the following MECCANO ERECTOR instructional booklets published by MECCANO are available from MECCANO, S. A., 363 Avenue de Saint Exupery, 62100 Calais, FRANCE : Junior Model, Junior Model 1310, Junior Model 1315, Junior Model 1320, Junior Model 1350, Junior Model 1355, Junior Model 1530 and Junior Model 1540. These instructional booklets provide some of the structures that can be created using the construction kit according to the present invention. Also, different kits can be combined to achieve larger or more complex structures. Moreover, it would be understood that the kit according to the present can include other accessories for the construction elements that are specifically not specifically shown such as hooks, belts, other tools such as pliers and wrench. It would also be apparent to one skilled in the art that the above disclosed construction elements can be molded from any suitable durable material such as plastics, particularly ABS, polypropylene, nylon, etc. The foregoing description is only illustrative of the principle of the present invention. It is to be recognized and understood that the invention is not to be limited to the exact configuration as illustrated and described herein. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention accordingly is to be limited to as set forth in the appended claims.

A construction toy kit comprises a plurality of construction elements and fasteners adapted for forming structures of various forms. The construction elements comprise straight flat strip, angled flat strips of various configurations, plates of various configurations, angled brackets of various configurations, blocks of various forms, and other accessories such as axle rods of various lengths, wheels, pulleys, locking clips, pin connectors, fasteners, spacers, washers, etc. Each of the construction elements has at least two holes of a same diameter, each hole having an associated concentric embossment formed therearound. The kit also includes a hand toy tool for tightening and loosening fasteners, which could also be used an accessory of the construction element. The kit further includes a container for holding the components thereof.

BACKGROUND OF THE INVENTION [0001] The present invention relates to an elevator consisting of an elevator cage movable in an elevator shaft, and a counterweight. The elevator cage and the counterweight are connected by means of a support and drive means guided over deflecting rollers. A drive drives the elevator cage and the counterweight. [0002] An elevator installation is known from European reference EP 01811132.8, in which an elevator cage and a counterweight are movable in an elevator shaft along guide rails. The elevator cage and the counterweight are connected by means of a belt, wherein a 2:1 belt guide with underlooping of the elevator cage is provided. The belt ends are each arranged at an upper end of a guide rail. The belt is guided by way of two deflecting rollers arranged underneath the elevator cage and supports the elevator cage, by way of a drive roller of a drive arranged at the upper end of a guide rail and by way of a deflecting roller supports the counterweight. The guide rails supporting the elevator cage, the counterweight and the drive introduce the vertical forces into the shaft pit. [0003] A disadvantage of the known equipment resides in the fact that the deflecting rollers arranged outside the elevator cage or the counterweight oblige a larger shaft height, a larger shaft width and a deeper shaft pit. SUMMARY OF THE INVENTION [0004] Accordingly, it is an object of the present invention to provide an elevator installation that avoids the disadvantages of the known equipment and is constructed to be smaller. [0005] Pursuant to this object, and others which will become apparent hereafter, one aspect of the present invention resides in an elevator having an elevator shaft, an elevator cage movable in the elevator shaft, and having a floor and a roof, and a counterweight. A support and drive means is arranged to connect the elevator cage with the counterweight. Deflecting rollers are integrated in either the floor or the roof of the elevator cage between two plates. A support and drive means is guided over the deflecting rollers and is driven by a drive so as to drive the cage and the counterweight. [0006] In another embodiment of the invention, the deflecting rollers are integrated in the floor and the support and drive means is guided in a channel in the floor. [0007] In still another embodiment of the invention, the deflecting rollers are integrated in the roof and the support and drive means is guided in a channel in the roof. [0008] In still a further embodiment of the invention, elements are provided for supporting the deflecting rollers. The support elements are connected with either the cage floor or the cage roof. The floor or roof to which the elements are connected is of a sandwich construction. [0009] In another embodiment of the invention, additional deflecting rollers are integrated into the counterweight. The counterweight has a cut out for receiving the additional deflecting rollers. [0010] The counterweight is provided with an offset in a further embodiment of the invention, which off set is configured so that the counterweight can move past the drive. [0011] The advantages achieved by the invention are essentially to be seen in that the elevator cage as well as the counterweight can be constructed to be more compact. By integration of the deflecting rollers in the elevator cage or in the counterweight, the shaft height, shaft width and pit depth can be dimensioned to be smaller. The cogged belt employed as support and drive means allows small bending radii and thus small diameters for the deflecting rollers and the drive wheels. Moreover, the cogged belt is disposed in mechanically positive connection with the drive wheels of the mechanical linear drive and with the deflecting rollers provided with a brake. A mechanically positive connection of the drive and support means with the drive wheels or with the brake rollers enables a lightweight mode of construction of the elevator cage. In particular, the cage floor or the cage roof with the integrated deflecting rollers can be realized by a stiff sandwich mode of construction capable of bearing loads. By comparison with a conventional cage floor with deflecting rollers (bottom blocks) arranged underneath, the cage floor of the present invention is constructed to be very small in height, which has a direct effect on the shaft pit depth. The height gained by the cage floor can be saved in the shaft pit depth. Moreover, the belt can be guided near the cage wall, which in turn has a favorable effect on shaft width. By comparison with a conventional cage roof with deflecting rollers (top blocks) arranged at the top the cage roof of the present invention can be constructed to be very small in height, which has a direct effect on the shaft head height. The height gained by the cage roof can be saved in the shaft head height. [0012] For a more complete understanding of the elevator of the present invention, reference is made to the following detailed description and accompanying drawings in which the presently preferred embodiments of the invention are illustrated by way of example. That the invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it is expressly understood that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention. Throughout the following description and drawings, identical reference numbers refer to the same component throughout the several views. BRIEF DESCRIPTION OF THE DRAWINGS [0013] [0013]FIG. 1 shows an elevator with deflecting rollers integrated in the floor of the elevator cage; [0014] [0014]FIG. 1 a shows a cage floor without a centrally arranged profile roller; [0015] [0015]FIGS. 2, 3 and 4 show different arrangements of the deflecting rollers in the cage floor; [0016] [0016]FIGS. 5 and 6 show a deflecting roller arranged at the guide center of the elevator cage; [0017] [0017]FIGS. 7 and 8 show a deflecting roller arranged outside the guide center of the elevator cage; [0018] [0018]FIGS. 9 and 10 show a counterweight with integrated deflecting rollers; and [0019] [0019]FIG. 11 shows an elevator with deflecting rollers integrated in the roof of the elevator cage. DETAILED DESCRIPTION OF THE INVENTION [0020] An elevator, which consists of an elevator cage 3 movable in an elevator shaft 2 and a counterweight 4 and which is denoted by 1 , is illustrated in FIG. 1. The elevator cage 3 is guided by means of a first guide rail 5 and by means of a second guide rail 6 . The counterweight 4 is guided by means of a third guide rail 7 and by means of a fourth guide rail, which is not illustrated. The guide rails are supported in a shaft pit 8 , wherein the vertical forces are conducted into the shaft pit 8 . The guide rails 5 , 6 and 7 are connected with the shaft wall by brackets, which are not illustrated. Buffers 9 , on which buffer plates 10 of the elevator cage 3 or the counterweight 4 can be placed, are arranged in the shaft pit 8 . [0021] A belt 11 , for example a cogged belt, with a 2:1 belt guidance is provided as support and drive means. When a mechanical linear drive 12 , which is arranged at the second guide rail 6 , for example in the shaft head 2 . 1 , advances the belt 11 by means of a drive wheel 13 through one unit, the elevator cage 3 or the counterweight 4 moves through a half unit. One end of the belt 11 is arranged at a first cable fixing point 14 and the second end of the belt 11 is arranged at a second cable fixing point 15 . The belt 11 is guided over a first deflecting roller 16 , over a profiled roller 17 , over a second deflecting roller 18 , over a third deflecting roller 19 , over the drive wheel 13 and over a fourth deflecting roller 20 . The first deflecting roller 16 , the second deflecting roller 18 and the profiled roller 17 are integrated in the floor 21 of the elevator cage 3 , wherein the belt runs in a floor channel 21 . 1 . As in the embodiment of FIG. 1 a , the profiled roller 17 can be omitted. The profiled roller 17 has a toothing corresponding with the toothing of the belt 11 . The first deflecting roller 16 and the second deflecting roller 18 guide the belt 11 on the untoothed side by means of flanges arranged at the end faces of the rollers. The third deflecting roller 19 arranged at the second guide rail 6 is disposed by its toothing in engagement with the toothed side of the belt 11 and comprises a brake for normal operation. The drive wheel 13 is disposed by its toothing in engagement with the toothed side of the belt 11 . Diverting rollers 22 of the linear drive 12 increase the angle of looping of the belt 11 at the drive wheel 13 . The motor or motors for the drive wheel 13 is or are not illustrated. The fourth deflecting roller 20 is arranged in the counterweight and is comparable in construction with the first deflecting roller 16 or with the second deflecting roller 18 . [0022] [0022]FIG. 2, FIG. 3 and FIG. 4 show different arrangements of the deflecting rollers 16 , 18 in the cage floor 21 in the region of the guide center 23 of the elevator cage 3 . FIG. 2 shows the deflecting rollers 16 , 18 , which are arranged behind the guide rails 5 , 6 , with a first roller R 1 and a second roller R 2 , wherein each roller is provided with a belt 11 . The rollers R 1 , R 2 are independent of one another and are free-running. The belts 11 run behind the guide shoe. Details with respect to these variants are illustrated in FIG. 5 and FIG. 6. [0023] [0023]FIG. 3 shows rollers R 1 , R 2 disposed outside the guide rails 5 , 6 . The belts 11 run behind the guide shoe. The roller spacing determines the belt spacing and thus the spacing of the drive wheels 13 and the length of the mechanical linear drive 12 . [0024] [0024]FIG. 4 shows doubly executed deflecting rollers 16 , 18 , which are comparable in construction with FIG. 2, with rollers R 1 , R 2 disposed outside the guide rails 5 , 6 . This arrangement for four belts 11 is provided for larger support forces. [0025] [0025]FIG. 5 and FIG. 6 show the detail A of FIG. 1 a with a first deflecting roller 16 arranged at the guide center 23 of the elevator cage 3 . FIGS. 5 and 6 are also applicable in the same sense for the second deflecting roller 18 . The section of the cage floor 21 is taken through the guide center 23 . The cage floor 21 constructed in sandwich mode of construction consists of a roof plate 24 and of a floor plate 25 , between which a foam filling 26 is arranged, wherein the floor channel 21 . 1 for the belt 11 is cut out. The roof plate 24 supports a floor covering 27 and, in the edge regions, a base profile member 28 on which wall elements 29 can be placed. In the corners of the cage floor 21 the base profile 28 is connected by means of rods, which are not illustrated, with the cage roof, which is not illustrated. The rollers R 1 , R 2 are arranged to be free running on an axle 30 , wherein the axle 30 is mounted in a base 31 . The base 31 is connected with the floor plate 25 and the roof plate 24 , and consists of a support element 31 . 1 , an insulating element 31 . 2 and a top element 31 . 3 . A safety brake device 3 . 1 , which stops the elevator cage 3 in the case of emergency, is arranged underneath the deflecting roller 16 . As shown in FIG. 6, the deflecting roller 16 is arranged below a bracket supporting a guide shoe 32 , wherein there is still place for the belts 11 between the bracket 33 and the rollers R 1 , R 2 . [0026] [0026]FIG. 7 and FIG. 8 show the detail A of FIG. 1 a with first deflecting rollers 16 , which are arranged outside the guide center 23 of the elevator cage 3 , according to FIG. 4. FIGS. 7 and 8 are applicable in the same sense for the second deflecting rollers 18 . The construction and arrangement in the cage floor 21 of the deflecting roller 16 is comparable with the embodiments according to FIGS. 5 and 6. [0027] [0027]FIG. 9 and FIG. 10 show a counterweight 4 with integrated deflecting rollers 20 . In the upper region the counterweight 4 has an offset 4 . 1 , wherein the offset 4 . 1 is so dimensioned that the counterweight 4 can move past the mechanical linear drive 12 . Moreover, a cut-out 4 . 2 , in which the deflecting rollers 20 are integrated, is arranged at the counterweight 4 . With the offset 4 . 1 in the counterweight 4 and the deflecting rollers 20 integrated in the cut-out 4 . 2 the shaft height or the shaft head height can be fully utilized. [0028] [0028]FIG. 11 shows an elevator with deflecting rollers 16 , 18 integrated in the roof 40 of the elevator cage 3 . The mechanical linear drive 12 and the counterweight 4 are constructed according to FIGS. 9 and 10. The roof 40 of the elevator cage 3 has a roof channel 40 . 1 in which the belt 11 , which serves as support and drive means, is guided. The arrangement of the deflecting rollers 16 , 18 is in the same sense as FIGS. 1 a to 8 . [0029] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

An elevator having deflecting rollers integrated in the cage floor or in the counterweight. The support and drive element is guided in the cage floor through a floor channel. By comparison with a conventional cage floor with deflecting rollers (bottom blocks) arranged underneath the cage floor, the cage floor is constructed to be very small in height overall, which has a direct effect on the shaft pit depth. The height gained by the cage floor can be saved in the shaft pit depth.

FIELD OF THE INVENTION [0001] The invention relates generally to a thermal inkjet printer; and more generally, to an optimum initial operating temperature for a thermal inkjet printer. BACKGROUND OF THE INVENTION [0002] In designing a thermal inkjet printer, it is important to provide as economically and simply as possible a relatively high output quality at a relatively high speed. The output quality and relative speed of a thermal inkjet printer are often times a function of the startup operating temperature of the printhead, especially after a period of non-use. [0003] For example, conventional thermal inkjet printers contain multiple inkjet nozzles. Associated with each nozzle is a heating resistor and a drive transistor. The nozzle includes a nozzle chamber within which the heating resistor is located. To fire ink from the nozzle chamber, the drive transistor outputs a firing pulse to the heating resistor. The firing pulse is a current pulse of a magnitude sufficient enough to heat up the resistor and thus the ink to an ejection temperature. The ink then ejects from the chamber toward a print media sheet. To determine when any given nozzle is to fire, a controller circuit is used. [0004] Typically, existing printers use a single print head operating temperature throughout the duration of printing a document. If this temperature is set too high, then a variety of longer term reliability issues can occur such as ink plugs in the nozzles, material degradation in the print head, or ejection of overly concentrated colorant from evaporation of the ink vehicle thought the nozzles. If this temperature is set too low, then there can be significant initial short term reliability issues with getting the print head to reliably fire when first called upon to do so. What is needed is high initial ejection reliability of high initial operating temperatures combined with the improved long term reliability afforded by lower operating temperatures for the duration of an image. [0005] In certain printers, to maximize reliable ink drop ejections, the ink is pre-heated. However, to pre-heat the ink when the printer is not is use would result in a waste of energy and ink as the ink will thicken or be reduced through evaporation. Furthermore, because of ink evaporation, pre-heating the ink during a long period of non-use may damage the printhead. For all these obvious reasons, therefore, the resistors are not pre-heated if the printer is not in use. [0006] It is well known in the industry that one of the problems associated with thermal inkjet printers concerns the amount of ink ejected or deposited from the printhead during the formation of each ink drop. The quantity of deposited ink, commonly referred to as the “drop-volume” of the printhead, is dependent on the temperature of the printhead. If the printhead is cool, it will deposit less ink in each droplet. Missing, weak or low drop-volume results in poor quality images that appear faint or washed out. Consequently, when a printer has gone through a period of non-use or the printhead is cool, a certain amount of firing time is required to allow the printhead to reach its optimum drop-volume. This is usually accomplished by having the nozzles spit or eject low drop-volume ink droplets into a spittoon. Obviously, this scheme fosters ink wastage and a longer printing time. [0007] Therefore, what is needed is a method to facilitate a thermal inkjet printer to reach its optimum drop-volume from a period of non-use as quickly as possible while minimizing ink wastage. SUMMARY OF THE INVENTION [0008] To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present invention is embodied in a printing system for improving the edge sharpness, color uniformity, banding and faint or washed out appearance of ink drops produced by an inkjet printer. [0009] The need in the art is addressed by the present invention. The present invention provides a thermal inkjet printer with the requisite technology to increase or reduce its operating temperature. The printer uses a sensor to detect the operating temperature of its printhead. If the temperature of the printhead is below the printhead's default or normal operating temperature when the printer is going to start to print an image or document, the operating temperature of the printhead is set at a temperature higher than its default or normal temperature. [0010] This is to ensure that the drop-volume of the printer stays at an optimum level when the printer is starting to print the image or document after a period of non-use. Shortly after the printer has started the printing task, the operating temperature of the printhead is reduced to its default normal operating temperature. The higher temperature depends on the probability of successful ejection of the nth drop. Satisfactory image quality depends on all drops to have the proper volume, velocity and directionality. [0011] The present invention as well as a more complete understanding thereof will be made apparent from a study of the following detailed description of the invention in connection with the accompanying drawings and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The present invention can be further understood by reference to the following description and attached drawings that illustrate the preferred embodiment. Other features and advantages will be apparent from the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. [0013] [0013]FIG. 1 depicts a block diagram of an inkjet printer connected to a workstation. [0014] [0014]FIG. 2 illustrates particular aspects of the printer and the workstation. [0015] [0015]FIG. 3 is a perspective view of the inkjet printer. [0016] [0016]FIG. 4 depicts a thermal inkjet printhead and a printhead controller. [0017] [0017]FIG. 5 illustrates one of a plurality of nozzles used in the present invention. [0018] [0018]FIG. 6 is a schematic diagram of a nozzle circuitry associated of the present invention. [0019] [0019]FIG. 7 is a schematic diagram of the power control circuit 648 . [0020] [0020]FIG. 8 illustrates a chart of temperature versus time of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0021] In the following description of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration a specific example in which the invention may be practiced. Other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. [0022] I. General Overview [0023] The present invention ensures reliable ejection of an optimum ink drop-volume as quickly as possible after a period of printer non-use. This is done by momentarily setting the temperature of the printhead at a temperature much higher than its standard operating temperature. After a certain period of time, the operating temperature of the printhead is reduced to its default or normal or standard operating temperature. In the present invention, the default or normal operating temperature of the printhead is 55 degrees Celsius and the higher temperature is 75 degrees Celsius. [0024] II. Detailed Operation of the Invention [0025] With reference now to the figures, FIG. 1 depicts a block diagram of an inkjet printer 110 connected to a workstation 120 . This invention may also be implemented in other types of printers, such as bubble jet printers. Further, although the invention is described in the context of printers, it may also be used in conjunction with other image reproduction systems such as copiers, scanners and the like. [0026] As is well known in the field, the workstation 120 has at least one processor 210 to process data, including printing data. The workstation 120 also has a system memory 220 (e.g., RAM) that holds data that is to be immediately used by the processor 210 and a storage system 230 (e.g., ROM, hard disk, floppy disk, CD-ROM etc.) to store application programs. One such application program is a printer driver that is used to control the printer 110 . [0027] The printer 110 itself has a processor 250 , a volatile memory 260 (e.g., RAM) and a non-volatile memory 270 (e.g., ROM, flash etc.). The processor 250 is used to control all moving mechanical parts of the printers as well as to heat up and to fire the nozzles. Just as in the case of the workstation 120 , the volatile memory 260 is used to hold data for the immediate use of the processor 250 . The non-volatile memory 270 is used to store, among other programs, the present invention. [0028] However, before delving into the present invention, a brief description of an inkjet printer is needed. FIG. 3 is a perspective view of the inkjet printer 110 . The printer 110 has an input tray 310 containing sheets of print medium which pass through a printing zone and along a print medium advance direction 320 , past an exit 330 into an output tray 340 . Electronics control 350 for commanding the processor 250 to perform various functions are included. [0029] A movable carriage 360 holds print cartridges 22 , 24 , 26 and 28 which respectively hold yellow (Y), magenta (M), cyan (C) and black (B) inks and dispense these inks upon command from the processor 250 . The back of the carriage 360 has multiple bushings (not shown) which ride along a slide rod 370 , enabling bidirectional movement of the carriage along the rod 370 . [0030] The carriage 360 thus moves along a carriage scanning direction 2 , above a sheet of print medium upon which an image is being formed by print cartridges 22 - 28 . The position of the carriage 360 , as it traverses the print medium back and forth, is determined by an encoder strip 380 . This very accurate positioning device enables selective firing of the various ink nozzles on each print cartridge at the appropriate times during each carriage scan to form the image. [0031] With each scan or swath pass of the carriage 360 , the print medium is advanced incrementally in the direction 320 along the print medium axis. These incremental advances allow for an image or document to be printed on a media sheet. [0032] [0032]FIG. 4 depicts a thermal inkjet printhead 410 and a printhead controller 411 . The printhead 410 includes a plurality of nozzles 412 and is part of an inkjet pen (not shown) used for printing ink onto a media sheet. Note that although two columns of nozzles, many more can be used and would be well within the scope of the present invention. Along with the nozzles, a temperature sensor 428 is shown. The temperature sensor is used to measure the temperature of the printhead 410 . The printhead controller 411 is connected to printhead 410 and monitors the temperature sensor 428 . [0033] [0033]FIG. 5 illustrates one of a plurality of nozzles used in the present invention. As shown in FIG. 5, each nozzle includes a nozzle chamber 516 for holding ink 511 and a heating resistor 518 . In operation, the heating resistor 518 receives a firing pulse from drive transistor 520 causing the heating resistor 518 to heat up the ink 511 in the chamber 516 to ejection temperature in order to eject the ink through orifice 524 . For each nozzle, there is a corresponding nozzle chamber 516 , heating resistor 518 , drive transistor 520 and heating transistor 526 . Although two transistors are used (one to preheat and one to drive resistor 518 ), the use of one transistor is perfectly within the scope of the present invention. In that case, the one transistor can fire less pulse current to pre-heat resistor 518 and more pulse current to drive resistor 518 . [0034] [0034]FIG. 6 is a schematic diagram of the nozzle circuitry associated with a given nozzle 412 . The heating resistor 518 is coupled to a nozzle voltage source 640 at one contact point and to the drains of the drive transistor 520 and warming transistor 526 at another contact point. The drive transistor 520 is formed by one or more power field effect transistor (FET) devices 642 . In the embodiment illustrated six FETs 642 a - 642 f formed the drive transistor 520 . The warming transistor 526 is formed by a smaller FET device 644 . [0035] The drains of the FET devices 642 and 644 are coupled in common to the heating resistor 518 via an interconnect 643 . The sources of the devices 642 and 644 are coupled in common to ground 646 . The gates M 1 -M 6 of the FET devices 642 a - 642 f are coupled to a power control circuit 648 which receives the firing control signal 532 . The gate M 7 of the warming transistor device 644 is coupled to the printhead controller 411 for receiving the warming control signal 530 . [0036] [0036]FIG. 7 is a schematic diagram of the power control circuit 648 . The power control circuit 648 is formed by a set of current booster circuits. A firing control signal is received from the printhead controller 411 . The signal is boosted to generate a signal 750 input to the gates M 1 -M 6 of the drive transistor devices 642 . In the illustrated embodiment, the power control circuit includes eight FET devices 752 - 766 and an inverter 768 . [0037] The firing control signal 532 is active when a logic low is received at the power control circuit 648 . The logic low is inverted at inverter 768 resulting in a logic high signal 750 output from the power control circuit 648 into the gates M 1 -M 6 of the drive transistor devices 642 . Referring again to FIG. 6, the gates M 1 -M 6 allow current flow through the devices 642 . Specifically, current flows from the nozzle voltage source 640 through the heating resistor 518 into the drains 72 a - 74 f to ground 46 . When an inactive signal (e.g., a logic high) is received at power control circuit 648 , signal 750 is a logic low. Thus, the junction from drain to source at drive transistor devices 642 a - 642 f is closed. [0038] When an active signal level is received at the warming transistor device 644 , gate M 7 enables current flow through the device 644 . Specifically, current floes from the nozzle voltage source 640 through the heating resistor 518 into the drain 82 and out through the source 84 of the warming transistor 644 to ground 646 . When an inactive signal level is received at the gate M 7 of the warming transistor device 644 , the junction from drain 82 to source 84 is closed. [0039] The warming control signal 530 and the firing control signal 532 are separate signals having separate signal paths. To generate a warming pulse, the firing control signal 532 is inactive and the warming control signal is active. Thus, a small current flows from the nozzle voltage source 640 through the heating resistor 518 into the drain 82 and out the source 84 of the warming transistor 644 to ground 646 . The current flowing through the heating resistor 518 is based upon the size of the transistor device 644 . Such current is insufficient to cause the nozzle 412 to fire. Warming transistor device 644 is used as a switching device turning the current flow through the device 644 on or off. The current magnitude for a warming pulse may be between 2.0 and 3.5 mA; and the nozzle voltage around 21 volts. [0040] To generate a firing pulse, the warming control signal 530 is inactive and the firing control signal is active. Thus, current flows from the nozzle voltage source 640 through the heating resistor 518 into the drains 72 a - 72 f and out of the source 74 a - 74 f to ground 646 . The current flowing through the heating resistor 518 is based upon the number and size of the transistor devices 642 a - 642 f . Such current is enough to cause a nozzle 412 to fire. The current magnitude for a firing pulse may be around 300 mA and the nozzle voltage source around 21 volts. [0041] Obviously, other voltage and current levels may be used in alternative embodiments. Furthermore, to fire a nozzle 412 both a firing signal 532 and a warming signal 530 may be active so that current flows from the nozzle voltage source 640 through the heating resistor 518 and through all the devices 642 and device 644 to ground 646 . [0042] When both the firing control signal 532 and the warming control signal 530 are inactive, current does not flow through the devices 642 and 644 . Consequently, current does not flow through the heating resistor 518 . [0043] Returning back to FIG. 4 and FIG. 5, when a given nozzle 412 is to be fired, the controller 411 sends a firing control signal 532 to drive transistor 520 for such nozzle 412 . Further, as the controller 411 monitors temperature sensor 428 , if it detects that the temperature of the printhead falls below a threshold temperature, the controller 411 generates a warming control signal 530 for one or more nozzles 412 to bring the printhead temperature back to the operating temperature. In the present invention, the printhead operating temperature is around 55 degrees Celsius. [0044] When the printer is not in use, the printhead temperature will fall below the operating temperature of 55 degrees Celsius. It will continue to fall until it reaches ambient temperature, which often is room temperature (around 25 degrees Celsius). When a printhead starts at that temperature, it often requires a certain number of spits before optimum drop-volume can be reliably achieved. In an experiment, it was shown that if the printhead temperature is brought to the 55 degrees Celsius operating temperature from a period of non-use, at least 10 spits (this number depends on the printer) were needed before the optimum drop-volume was achieved. It was also shown that if the printhead temperature is brought to 75 degrees Celsius, zero spits was needed to obtain the optimum drop-volume. Thus, 75 degrees Celsius seems to be an ideal start-up temperature for the printhead. [0045] However, having the printhead operate continually at that high of a temperature can foster reliability issues such as material incompatibility. Furthermore, the higher temperature may foster faster water evaporation (in the case of a water based ink) through the nozzles which ultimately may cause ink plugs. Thus, after the initial start-up temperature of 75 degrees Celsius, the temperature of the printhead should be reduced to the optimum 55 degrees Celsius operating temperature. In that experiment it was shown that if the temperature of the printhead was reduced to 55 degrees Celsius after 5 to 500 ink droplets (this number depends on the inkjet printer), no problems with reliability issues or ink plugs ensued. [0046] In the present invention, therefore, the printhead controller 411 of FIG. 4 is designed to bring the initial temperature of the printhead 414 momentarily to 75 degrees Celsius and then to reduce the printhead operating temperature to 55 degrees Celsius. The 75 degrees Celsius temperature allows for a more efficient ink ejection (i.e., grams of ink per uJ of energy). This efficient ink ejection eliminates ink plugs and chamber bubbles. Consequently, the time for nozzle recovery is significantly reduced. [0047] [0047]FIG. 8 illustrates a chart of temperature versus time of the present invention. Dashed line 810 is the control temperature line and solid line 820 is the actual printhead temperature line. Note that the control time for the higher temperature can vary anywhere from 10 msec to 1 sec. In this figure, the higher temperature is set at 75 degrees Celsius and the default or normal operating procedure is set at 55 degrees Celsius, but both temperatures can vary. This variation may be dependent upon a particular printer. [0048] IV. Conclusion [0049] The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Therefore, the foregoing description should not be taken as limiting the scope of the invention defined by the appended claims. [0050] The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. As an example, the above-described inventions can be used in conjunction with inkjet printers that are not of the thermal type, as well as inkjet printers that are of the thermal type. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.

A thermal inkjet printer is provided. The printer has a sensor that detects the operating temperature of its printhead. If the temperature of the printhead is below the printhead's normal operating temperature when the printer is going to start to print an image or document, the operating temperature of the printhead is set at a temperature higher than its normal temperature. This is to ensure that the drop-volume of the printer stays at an optimum level when the printer is beginning to start to print the image or document after a period of non-use. Shortly after the printer has started the printing task, the operating temperature of the printhead is reduced to its normal operating temperature.

RELATED APPLICATIONS The present application is a national stage entry according to 35 U.S.C. §371 of PCT application No.: PCT/EP2008/050504 filed on Jan. 17, 2008. TECHNICAL FIELD Various embodiments relate to a method and a device for detecting a statistical characteristic of a lighting device. BACKGROUND Various embodiments relate in general to detecting statistical characteristics of a lighting device. These are to be understood, for example, as operating hours or switching-on processes of the lighting device. The reason for this measure resides in the fact that, for example, the light yield of LEDs depends strongly on ageing. By way of example, it is then possible to change the driving of the LEDs as a counter measure, depending on the detected operating hours. As regards defective returns, the number of operating hours or the number of switching-on processes is an important criterion in determining the cause of failure. In critical fields of application of lighting devices, for example OP luminaires, traffic lights, street lamps, maintenance intervals can be complied with after detection of the operating hours or the switching-on operations, it being possible thereby for failures of the lighting device that are fraught with consequences to be virtually completely prevented. Different storage devices, for example flash memories, E2Proms, hard disks, etc are used in the prior art to detect such statistical characteristics. In this case, flash memories constitute the most advantageous variant, but are associated with the disadvantage that they cannot be written to as frequently as the other storage media. It is typically possible to write to flash memories up to approximately 50 000 times. E2Proms, which are, however, substantially more expensive than flash memories, offer the advantage that they permit up to 500 000 write cycles. On the one hand, as storage media hard disks require to be brought up to speed in order to carry out a write operation, something which is associated with time and energy requirement, and on the other hand are themselves expensive in small quantities. The shorter the time unit that is to be detected is selected, for example hours or seconds, the more frequently the write cycles need to be carried out, and the more stringent the requirements placed on the selected storage medium. Moreover, there is also the problem that, as regards switching off the lighting device, the internal supply must be maintained for a sufficiently long time such that the characteristic can be secured. This is associated with the further disadvantage that large and therefore expensive buffer capacitors must be made available for supplying the components essential to the storage operation. SUMMARY Various embodiments provide a method and a device for detecting a statistical characteristic of a lighting device that enables the use of cost effective media, for example the use of flash memories. Various embodiments are based on the finding that the required accuracy for such statistical characteristics of lighting devices is usually not particularly high. In general, a value of a few percent is perfectly sufficient. Consequently, it is possible not to carry out each write cycle, but to store only every tenth, hundredth or even thousandth cycle. Various embodiments are further based on the finding that this can be achieved without also counting when a random variable is used in order to determine whether a write cycle is or is not carried out this time. It is therefore possible to reduce the number of write cycles, the result at the end merely be scaled by a specific factor. This strategy furthermore enables the write cycles to be carried out even during the operation of the lighting device such that it is not dependent on any buffering of the voltage supply for the elements acting during the write operation. Whereas the prior art provides a plurality of writable cells in a storage device such that, a transition is made from one cell to the next in order to prevent a failure after a prescribable number of write cycles, it is possible in the case of the present invention for the memories to be of small design, or to detect further reaching operating data, for example cycle type, temperature integral, etc. A particular advantage of the present invention resides in the fact that despite a low number of write cycles it enables the detection even at very short operating times, for example 1 s or 10 s. In the case of the inventive method the first step is to generate a random number within a prescribable value range, this being followed by a comparison of the random number with a comparison number. If this comparison yields a match, the count of a storage device is increased by one step width. The comparison number is preferably a prescribable number from the value range from which the random number is generated. Moreover, it is preferably provided, if the comparison step yields no match, to terminate the method without increasing the count of the storage device by one step width. In the abovementioned preferred embodiments, the characteristic is preferably correlated with the switching-on processes of the lighting device, said steps being run through each time the lighting device is switched on. In the case of another category of preferred embodiments, the comparison number can be correlated with the count of a time measuring device that is started when the lighting device is switched on. Here, the method in accordance with patent claim 1 preferably further includes the following steps: if the comparison step yields no match, the comparison step, in the case of which, after all, the comparison number changes continuously on the basis of the time detected by the time measuring device, is repeated until a match is achieved, the count of the storage device then being increased by one step width. If, however, the lighting device is switched off before a match is attained, the method is terminated. It is particularly preferred in this case when, after the count of the storage device has been increased by one step width and the lighting device has not yet been switched off, a pause is made until the count of the time measuring device has reached the value that corresponds to the maximum value of the prescribable value range in the step of the generation of a random number, and subsequently the method continues with this generation step. The count of the storage device is preferably continued each time after the lighting device is switched off so that the statistical characteristic of the lighting device can be detected over many switching-off operations. The step width by which the count of the storage device is increased is preferably 1. An inventive device for detecting the statistical characteristic of a lighting device includes a device for generating a random number within a prescribable value range; a comparison device for comparing the random number with a comparison number; and a storage device that is coupled to the comparison device in such a way that if the comparison of the random number with the comparison number yields a match, the count of the storage device is increased by one step width. The preferred embodiments, and their advantages, presented in conjunction with the inventive method are valid correspondingly, to the extent they can be applied, to the inventive device. In this case, corresponding devices are provided for each of the steps of the preferred embodiments of the inventive method. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which: FIG. 1 is a schematic flowchart for a first exemplary embodiment of an inventive method; FIG. 2 is a schematic illustration of a flowchart for a second exemplary embodiment of an inventive method; FIG. 3 shows a detail in the time domain for the exemplary embodiment of FIG. 2 ; FIG. 4 shows the result of a computer simulation for the exemplary embodiment of FIG. 2 ; and FIG. 5 is a schematic of an exemplary embodiment of an inventive device. DETAILED DESCRIPTION The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. FIG. 1 is a schematic flowchart for a first exemplary embodiment of an inventive method. The latter relates, by way of example, to the case when the aim is to detect the number of switching-on operations of a lighting device as characteristic. It begins in step 100 with switching on the lighting device. In step 120 , a random number between 0 and a prescribable maximum value of a value range, here 255 (corresponding to 2 8 -1), is generated. If the comparison of the random number generated in step 120 with an arbitrary comparison number from the same value range yields a match, the value of a memory location of a storage device is increased by 1 in step 160 . Subsequently, the method is terminated in step 180 independently of when the lighting device is switched off. If the comparison in step 140 yields no match, the method is likewise terminated in step 180 without increasing the value of the memory location. FIG. 2 is a schematic illustration of a flowchart for a second exemplary embodiment of an inventive method. This exemplary embodiment serves for detecting the operating time of a lighting device and serves, in particular, for implementing an operating seconds counter. It begins when the lighting device is switched on in step 200 . In step 220 , a random number is generated in a range between 0 and, presently, 65535 (corresponding to 2 16 -1). The maximum value of the value range can be fixed arbitrarily, but it determines the actual number of the write cycles executed. The larger this maximum number is selected, the smaller becomes the number of the write cycles actually carried out, as explained in yet more detail below. A seconds counter of a time measuring device is started in step 240 . During the comparison carried out in step 260 , the random number is compared with the current value of the seconds counter until a match is yielded. If this is the case, the value in a memory location of a storage device is increased by 1 in step 280 . Subsequently, a pause is made in step 300 until the seconds counter has reached the maximum value of the prescribed value range, presently 65535. A return is then made to step 220 , steps 220 to 300 being repeated until the lighting device is switched off. After the lighting device has been switched off, the method is started from the beginning, in particular independently of how far has already been counted in step 300 . This entails that when the method is run through for the first time it is already terminated before a “yes” in step 260 , or before the value “65536” is reached in step 300 . FIG. 3 shows the time profile of the method in accordance with the exemplary embodiment of FIG. 2 . Blocks of a length of in each case 65535 s are juxtaposed here. A random number is entered schematically in each block Bi. Switching-off instants t off1 are entered consecutively, in addition. In the block B 1 , the switching-off instant t off1 lies after the instant prescribed by the random number, and so the count rises to 1 in the memory location. In the block B 2 , the switching-off instant t off2 likewise lies, as does the switching-off instant t off3 in the block B 3 , after the instant that is respectively prescribed by the random number generated in the respective step 220 . This leads in each case to a further increase in the count. In the block B 4 , the lighting device is not switched off at all, but in fact the switching-off instant t off4 already lies in the block B 5 . This leads to the increase in the count to the value 4 at the instant that is fixed by the random number generated for the block B 4 . In the block B 5 , the instant that is determined by the random number lies after the switching-off instant t off4 , and so the count is not increased. In the block B 6 , the switching-off instant t off5 lies before the instant determined by the random number, and so the count continues to remain unchanged. FIG. 4 shows a schematic of the count of the storage device for an assumed operating time of 50 000 hours, a typical service life of an electronic ballast, for example of a lighting device, the 50 000 hours being composed of different switched-on durations of constant length. These different constant switched-on durations are given in FIG. 4 by the entries marked by squares. Switched-on durations of 20 s up to days are assumed in the illustration of FIG. 4 . For reasons of simplicity in programming the simulation, the constant switched-on durations were respectively assumed. In accordance with the illustration of FIG. 3 , the count is then increased by 1 if the random number generated in step 220 has already been reached, that is to say approximately every 65535 on average. Thus, assuming the switching-on time is constant at 10 s, the entire operating period is 65535 s. The probability of increasing the count in the storage device by 1 is therefore 10: 65535=1: 6553. In other words, every 6553 blocks a hit is attained during comparison and leads to an increase in the count. If the switched-on duration of 10 s is now multiplied by the number 6553, this results in the correct number of operating seconds of 65530 s. As shown in the example of FIG. 4 , this therefore results in 2746.62 blocks from 50 000 hours at 3600 s each divided by the period of 65535 s of a block. As is to be gathered from FIG. 4 , between 2650 and 2810 write cycles are carried out, depending on the switched-on duration selected. Given an operating seconds counter known from the prior art, which carries out a write operation every operating second, 180×10 6 write cycles would have to be carried out. In the case of the inventive method, by contrast, the operating seconds counter manages with a 1/65536 th of the write cycles. Nevertheless switched-on durations of a few seconds are also detected at the same time. The chart of FIG. 4 shows that the operating seconds are exactly correctly reproduced by up to approximately 3% by the inventive method. FIG. 5 shows a schematic of the design of an inventive device. The latter has an input with a first input connection E 1 and a second input connection E 2 , to which connections a system voltage U N is applied. It includes an electronic ballast 10 to whose output an illumination means 12 is coupled. An inventive device 14 is coupled between the input connections E 1 , E 2 and the electronic ballast 10 . This device has a device 16 for generating a random number within a prescribable value range. It further includes a comparison device 18 , coupled to the generation for comparing the random number with a prescribable comparison number. A storage device 20 is coupled to the comparison device 18 , specifically in such a way that the count of the storage device 20 is increased by a step width if the comparison of the random number with the comparison number yields a match. As is evident to the person skilled in the art, the inventive device can also be provided at another site than illustrated in FIG. 5 . Thus, by way of example it can, in particular, be accommodated in the electronic ballast 10 . Furthermore, an inventive device can be designed to detect a plurality of statistical characteristics of a lighting device, that is to say, by way of example, the number of the switching-on operations and the operating period, it being possible for these variables to be detected for different elements of the lighting device. In the case of the exemplary embodiment of FIG. 5 , it is therefore possible to detect the statistical characteristics separately for the electronic ballast 10 and the illumination means 12 which, after all, can be different after replacement of one of the two in the case of a defect or maintenance. While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

A method for detecting a statistical characteristic of a lighting device is provided. The method may include a) generate a random number within a prescribable value range; b) compare the random number with a comparison number; c) c1) if the comparison of step b) yields a match: increase the count of a storage device by one step width.

RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured, used and licensed by or for the U.S. Government for Governmental purposes without payment to us of any royalty thereon. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is in the field of MILES compatible inert training devices. These devices do not contain any explosives. 2. Background Art This invention is used in systems that train soldiers for combat. The system that this invention is used in conjunction with is called the "Multiple Integrated Laser Engagement System" or (MILES). The means of interaction of the present invention with the MILES system is described in the patent application of Campagnuolo and Gerber, Ser. No. 07/691,603, now U.S Pat. No. 5,199,874. The present existing MILES system contains a feature which is intended to sense the removal and replacement of batteries used to power the MILES equipment carried by the soldier. Circuitry in the MILES harness senses an acoustic signal generated by the MILES compatible Claymore training device (MCCTD) causing an alarm in the MILES system to activate indicating that a hit has taken place. This invention was developed to satisfy a need for an inert safe training device that could be used to train soldiers in the use of the actual Claymore mine. The Claymore mine is a directional mine that propels lethal pellets a distance of about 50 meters within an angle of about 60 degrees. The mine is detonated by an M57 Electrical firing device which is a hand held electrical pulse generator. When a handle on the M57 hand held generator is depressed, an electrical pulse is generated which fires a blasting cap connected into the mine through a 33 meter electrical cable. The presently existing Claymore mine training devices utilize a blasting cap in combination with an inert main charge. A need exists for a non-explosive training device that the present invention fullfills. The MILES compatible Claymore training device (MCCTD) which is the subject of this invention functions with the MILES system by flashing a light or lights when activated and radiating a directional acoustic signal which is received by the MILES system worn by the soldier. Accordingly, it is an object of this invention to provide an inert, safe, non-explosive, and reusable MILES compatible Claymore training device (MCCTD) which is compatible with the MILES system worn by soldiers during training exercises. It is another object of this invention to provide a (MCCTD) that radiates a directional acoustical signal. It is another object of this invention to provide a (MCCTD) that functions with the M57 type electrical pulse generator. It is another object of this invention to provide a (MCCTD) that cooperates with the MILES system by producing an acoustical signal that activates the MILES alarm within the directional radiation pattern of the MCCTD. SUMMARY This invention is a reusable, inert, non-explosive, MILES compatible CLAYMORE training device (MCCTD) which radiates a directional acoustic signal and flashes light upon activation. The directional radiation pattern is the same as the directional projectile pattern that the actual Claymore mine radiates upon detonation. The MCCTD is used instead of the actual CLAYMORE mine in training situations. BRIEF DESCRIPTION OF THE DRAWING A better understanding of the invention will be obtained when the following detailed description of the invention is considered in connection with the accompanying drawing(s) in which: FIG. 1 shows a sketch of the MILES compatible training device and the M57 pulse generator. FIG. 2 shows the mechanical configuration of the MILES compatible training device. FIG. 3 is an electrical schematic of the MILES compatible CLAYMORE training device (MCCTD). FIG. 4 shows a more detailed schematic of the MCCTD timer. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIGS.1 and 2 it can be seen that a stepped exponential horn 10 is at the center of the front face 11 of the MCCTD or training device 9. The exponential horn 10 is designed to have a radiation cone of about 60 degrees, the same as the 60 degree angle of lethality of the actual Claymore mine. A buzzer 20 is mounted behind the exponential horn 10. The MCCTD utilizes a housing 21 constructed almost exactly like the actual Claymore mine. The housing 21 has a flashlight light or lights 40 attached to said housing 21. Included are scissor type folding support legs 12 and a slit aiming device 13 used to aim and position the MCCTD 9. FIG. 1 also shows the M57 handheld pulse firing generator 100, the firing cable 71, and the firing plug 70 which are used to activate the MCCTD 9. FIG. 2 shows a mechanical block diagram configuration of the MCCTD 9. The components consisting of the buzzer 20, the electrical firing circuit 30, the SCR switch 60, and the battery 50 are positioned within the housing 21 in accordance with good engineering practice. A firing plug receptacle 72 is mounted on the housing 21 to receive the firing plug 70, which are a standard phone type plug and receptacle combination available to those practicing in this art. FIGS. 3 and 4 are electrical schematics of the MCCTD 9. FIG. 4 shows the schematic of a MC 1455G semiconductor timer chip which can be utilized in the MCCTD 9. The operation of the electrical components is standard to one working in this art. FIG.1 shows a stepped exponential horn 10 used to amplify and radiate the acoustic wave generated by the buzzer 20. The buzzer 20 is mounted behind the horn 10 and on the electrical firing circuit 30. The electrical circuit 30 is powered by a battery 50 which is activated by the M57 pulse generator 100 through a silicon controlled rectifier 60. The output of the electrical circuit 30 triggers the flashlight or flashlights 40. The flashbulbs or bulb 40 can be ordinary flashbulbs or more sophisticated multiple flashbulbs of the xenon, halogen, or other type common in the art, which would require standard engineering modifications in the electrical circuitry. Sources of light other than flashbulbs can be used and can be located inside of the housing 21 as shown in FIG. 1 which housing 21 can be made of a transparent or semi-transparent material. The buzzer 20 is activated at the same time that the flashbulbs or light 40 is activated, and stays on for about 3 seconds. This is sufficient time for the acoustic wave propagated through the directional horn 10 to be detected by a MILES system as described in the application of Campagnuolo and Gerber (Ser. No. 07/691,603). The cable 71 from the M57 pulse generator 100 is inserted into the receptacle 72 of the MCCTD 9 thereby connecting terminals A to A', B to B, and B' to B'. This arms the MCCTD 9. When the handle of the M57 pulse generator 100 is depressed, an electrical pulse is generated and applied to the gate of SCR 60 thereby turning 60 on. This action furnishes a current path from the battery 50 to the flashbulb or bulbs 40, causing 40 to fire. At the same time, power is applied to a 15 volt regulator, LM 340 51, and to timer MC1455G 52, causing buzzer 20 to turn on for about 3 seconds. The on-off buzzer signal which has a frequency of about 3.8 KHZ, is detected by a microphone in the MILES harness (worn by a soldier) thereby signalling that a "HIT" has taken place. This is described fully in the patent application cited above. Having described this invention, it should be apparent to one skilled in the art that the particular elements of this invention may be changed, without departing from its inventive concept. This invention should not be restricted to its disclosed embodiment but rather should be viewed by the intent and scope of the following claims.

A training device substantially identical in size and shape to the Claymore antipersonnel mine that cooperates with the existing MILES (Multiple Integrated Laser Engagement Set) system. The training device includes a directional acoustic signal that approximates the effectiveness range of the actual Claymore mine.

FIELD OF THE INVENTION [0001] The present invention relates to rotatable media data storage devices, as for example magnetic or optical hard disk drive technology, and servo technology for hard disk drives. BACKGROUND OF THE INVENTION [0002] Computer systems are fundamentally comprised of subsystems for storing and retrieving data, manipulating data, and displaying results. Nearly all computer systems today use optical, magnetic or magneto-optical storage media to store and retrieve the bulk of a computer system's data. Successive generations of ever more powerful microprocessors, and increasingly complex software applications that take advantage of these microprocessors, have driven the storage capacity needs of systems higher and have simultaneously driven read and write performance demands higher. Magnetic storage remains one of the few viable technologies for economically storing large amounts of data with acceptable read and write performance. [0003] There are basic components common to nearly all hard disk drives. A hard disk drive typically contains one or more disks clamped to a rotating spindle, heads for reading and writing information to the surfaces of each disk, and an actuator assembly utilizing linear or rotary motion for positioning the head for retrieving information or writing information to a location on the disk. A rotary actuator is a complex assembly that couples the head to a pivot point that allows the head to sweep across the surface of the rotating disk. [0004] The head moves across the surface of the disk writing or reading data to or from concentric tracks on the disk surface. Successive generations of hard disk drives, particularly in laptops and other mobile devices, have scaled to smaller form-factors while simultaneously achieving increases in storage capacity in part by increasing the density of tracks stored on each disk. As track density increases, greater precision is required for movements of the heads. Greater precision in head movements requires improved performance in rotary actuator motion. Improvements in the mechanics of hard disk drives, and in the writing of servo patterns on the disks, have greatly reduced the amount of rotary actuator motion necessary to maintain acceptable track mis-registration (TMR), and seek from head to head on a given cylinder of the hard disk drive. The reduced rotary actuator motion that results from those improvements, however, can negatively impact the low frequency response of the rotary actuator. BRIEF DESCRIPTION OF THE FIGURES [0005] Further details of embodiments of the present invention are explained with the help of the attached drawings in which: [0006] [0006]FIG. 1 is an exploded view of a typical hard disk drive for applying a method in accidence with one embodiment of the present invention. [0007] [0007]FIG. 2 is a partial detailed view of a disk from the hard disk drive shown in FIG. 1. [0008] [0008]FIG. 3A illustrates the movement of a rotary actuator from the hard disk drive shown in FIG. 1 following a track with a servo pattern written using a media writer, a self-servo written servo pattern, and a servo pattern written using a method in accordance with one embodiment of the present invention. [0009] [0009]FIG. 3B illustrates the relative displacement of the rotary actuator illustrated in FIG. 3A through one revolution of the disk. [0010] [0010]FIG. 4 illustrates an example of gain-frequency response curves for different displacements of a rotary actuator. DETAILED DESCRIPTION [0011] [0011]FIG. 1 is an exploded view of a hard disk drive 100 for applying a method in accordance with one embodiment of the present invention. The hard disk drive 100 has a housing 102 which is formed by a housing base 104 and a housing cover 106 . A disk 120 is attached to the hub of a spindle 122 , with the spindle 122 mounted to the housing base 104 . The disk 120 can be made of a light aluminum alloy, ceramic/glass or other suitable substrate, with magnetizable material deposited on one or both sides of the disk. The magnetic layer has tiny domains of magnetization for storing data transferred through heads 146 . The invention described herein is equally applicable to technologies using other media, as for example, optical media. Further, the invention described herein is equally applicable to devices having any number of disks attached to the hub of the spindle. The disks 120 are connected to the rotating spindle 122 (for example by clamping), spaced apart to allow a head 146 to access the surfaces of each disk 120 , and rotated in unison at a constant set rate typically ranging from 3,600 to 15,000 RPM (speeds of 4,200 and 5,400 RPM are common in hard disk drives designed for mobile devices such as laptops). [0012] An actuator 130 is pivotally mounted to the housing base 104 by a bearing 132 and sweeps an arc (shown partially in FIG. 3A) between an inner diameter of the disk and an outer diameter of the disk. Attached to the housing 104 are upper and lower magnet return plates 110 and at least one magnet that together form the stationary portion of a voice coil motor assembly 112 . The voice coil 134 is mounted to the actuator 130 and positioned in the air gap of the voice coil motor 112 , which applies a force to the actuator 130 to provide the pivoting motion about the bearing 132 . The voice coil motor 112 allows for precise positioning of the head 146 along the radius of the disk 120 . The voice coil motor 112 is coupled with a servo system (not shown) that acts as a guidance system, using positioning data read by the head 146 from the disk 120 to determine the position of the head 146 over a track on the disk 120 . Each side of a disk 120 can have an associated head 146 , and the heads 146 are collectively coupled to the actuator 130 such that the heads 146 pivot in unison. The invention described herein is equally applicable to devices wherein the individual heads separately move some small distance relative to the actuator. This technology is referred to as dual-state actuation (DSA). [0013] One type of servo system is a sectored, or embedded, servo system in which tracks on all disk surfaces contain small segments of servo data often referred to as servo wedges or servo sectors. Each track can contain an equal number of servo wedges, spaced relatively evenly around the circumference of the track. Hard disk drive designs have been proposed having different numbers of servo wedges on different tracks, and such hard disk drive designs could also benefit from the invention contained herein. FIG. 2 shows a magnified portion of the disk 120 . The servo patterns 268 contained in servo fields 262 are read by the head 146 as it passes over each sector 260 and a position error signal (PES) is generated to correct off-track deviations. One track following scheme records track following signals in bursts 268 arranged in four columns to allow for a quadrature PES. FIG. 2 shows an arrangement wherein the density of servo bursts is greater than the density of tracks by a factor of 1.5. In other embodiments, the ratio of densities can be greater or less than shown in FIG. 2; for example the density of servo bursts can be the same as the density of tracks. [0014] In the scheme shown in FIG. 2, the centerlines of tracks are alternately defined by boundaries between bursts from columns A and B and boundaries between bursts from columns C and D. If the head 146 remains centered over a track centerline 266 , a PES of zero is calculated and no change in position is required. As the path of the head 146 deviates from the track centerline 266 , a difference in the relative amplitudes of successive burst signals 268 is detected by a controller (not shown), a PES is calculated, and an appropriate actuation current is applied to the voice coil motor 112 , which repositions the head 146 . The scheme described above is only one of many possible schemes. Drives using most (if not all) possible PES schemes could benefit from the invention contained herein. [0015] Servo patterns can be written to the disks prior to assembly of the hard disk drive using a media writer. Stacks of disks are loaded onto the media writer and servo patterns are carefully written onto the surface of each disk, a time consuming and costly process. The invention disclosed herein is equally applicable to other methods of writing servo patterns; for example, in some embodiments, the servo patterns can be printed. The media writer attempts to write servo patterns that follow perfect, concentric circles. A phenomenon called “repeatable runout” (or “eccentricity”) occurs if the axis of rotation of the disk is shifted from the center of the concentric tracks. The shifting of the center of the tracks from the axis of rotation of the disk comes about largely because the clearance between the disk and a hub of the media writer and between the disk and the hub of the spindle biases the disk along one edge of each hub. A bias resulting from the clearance between the disk and the hubs can result in eccentricities of one mil or more for each disk. For disks having a track density of 100,000 tracks per inch (TPI), this eccentricity can translate to over one hundred tracks. The eccentricity is compounded for multiple disks, most severely when the disks are biased along opposite edges as connected with the spindle. [0016] As a result of the shift between the axis of rotation and the center of the tracks, the track followed by the head is displaced laterally in a sinusoidal fashion relative to the head as the disk rotates. This sinusoidal displacement is referred to as repeatable runout, or eccentricity. FIGS. 3A and B illustrate different paths that the head 146 traces as it follows the servo pattern of a track. A servo pattern 380 written by the media writer is shown following a perfectly circular track with a center offset from the center of the spindle. The offset is exaggerated to show relative scale, and as described above can typically be one mil or more for each disk. FIG. 3B plots the total displacement of the head 146 over the course of a single revolution of the disk 120 . The actuator 130 must continuously pivot about the bearing 132 so that the head 146 sweeps an arc 352 that traces the servo pattern 380 and keeps the head 146 over the center of the track. Runout compensation schemes for following eccentric tracks are well known in the art. For example, one such scheme is described in U.S. Pat. No. 5,404,253 to Painter, entitled: “Estimator-based Runout Compensation in a Disk Drive.” [0017] A disk having two surfaces for storing data will have a head associated with each surface. Similarly, additional disks will have additional heads associated with each surface of each disk. As the hard disk drive writes or reads data, the controller switches between heads to access different surfaces. The heads may not be perfectly aligned, and each head may be offset across the surface of the disk relative to every other head. This offset likely differs from the offset of the heads in the media writer. As the head follows a track along the surface of the disk, every other head connected with the actuator is generally positioned over a different track on the respective disk surface. The offset between the heads can degrade performance of the hard disk drive as lag is introduced during head switches. [0018] One method known in the art for eliminating the effects of offset between the heads is the method of self-servo writing using a media-written disk. A master servo pattern is written on a single surface of a single disk with a media writer for use as a reference for self-writing servo patterns to all surfaces (including, possibly, the reference surface). The hard disk drive is assembled with the media-written disk alone or with the media-written disk and blank disks. The hard disk drive then self-writes servo patterns onto the storage surfaces based on the master servo pattern. As it does so, the hard disk drive can use electronics to counteract eccentricity of the master servo pattern introduced by the shift in track center, described above, before carrying out the step of self-writing the servo patterns. The master servo pattern on the reference surface is eventually over-written by user data. Other methods for writing master servo patterns, including printed-media self-servo writing and propagation self-servo writing can suffer from the effects of offset between the heads. The invention described herein is equally applicable to methods using disks having master servo patterns written other than by a media-writer. [0019] Ideally, self-servo writing produces perfectly circular, concentric tracks with each head positioned over the same track on the head's respective surface. As can be seen in FIGS. 3A and B, a perfectly circular track 382 exhibits zero eccentricity, and therefore zero displacement of the head. But achieving zero (or nearly zero) actuator motion while following a track can degrade performance of an actuator positioning controller due to frictional effects in the bearing. The problem is more pronounced in smaller hard disk drives where smaller bearings exhibit less rotational inertia. Actuator positioning controllers are generally designed assuming that the motion dynamics of the actuator are linear or nearly linear; however, the frictional effects in the bearing limit low-frequency gain. The nonlinear behavior of bearings is further described in an article entitled “Disk Drive Pivot Nonlinearity Modeling Part I: Frequency Domain” by D. Abramovitch, F. Wang, and G. Franklin, In the Proceedings of the 1994 American Controls Conference in Baltimore, Md., (June 1994), incorporated herein by reference. [0020] Hard disk drives used in laptops and other mobile devices must tolerate shock and vibration, major contributors to low-frequency disturbances; however, non-linear gain response can interfere with the ability of the actuator positioning controller to reject low-frequency disturbances. An article entitled “Use of Dither in Digital Servo Control for DASD” by R. J. Daede, J. E. Mason, and H. H. Ottesen, IBM Technical Disclosure Bulletin , (October 1990), also incorporated herein by reference, describes overcoming frictional effects in the bearing by continuously moving the actuator. The article proposes providing a dithering signal at an integer multiple of the servo sample rate. As the head dithers, it is effectively (and intentionally) off-track between servo samples. [0021] A method in accordance with the present invention can be used to introduce an optimal track eccentricity such that frictional effects can be overcome while the head is kept on-track between servo samples by a run-out compensation scheme. In one embodiment the method comprises the steps of writing a master servo pattern on one surface of a disk to be inserted into the hard disk drive shown in FIG. 1, assembling the hard disk drive, reading the master servo pattern from the surface of the disk, determining the optimal track eccentricity, and writing a servo pattern similar to the master servo pattern onto each surface except that the servo pattern follows the optimal track eccentricity. The master servo pattern can then be erased or over-written by user data. [0022] The optimal track eccentricity is an eccentricity that incorporates the minimum amount of movement of the head while following the track such that the motion dynamics of the actuator are linear or approximately linear, wherein an approximately linear region of a mechanical transfer function is a region within a few decibels of a 1 s 2 [0023] response curve. The optimal track eccentricity may incorporate once-around runout, that is, the movement of the head may vary sinusoidal with the same frequency as the period of rotation (thus the head completes one period of motion per revolution), or the optimal track eccentricity may incorporate some integer multiple of the period of rotation. The eccentricity must be an integer multiple of the period of rotation for the tracks to be continuous (i.e., not to have a large discontinuity where an end of a track meets a beginning of the track). FIGS. 3A and B illustrate an optimal track eccentricity incorporating twice-around runout 384 . The head 146 completes two periods of motion for every revolution of the disk. For a disk rotating at 5400 RPM, the head oscillates at a frequency of 180 Hz. [0024] The amplitude of the oscillation of the head, and thus the sinusoidal movement of the optimal track eccentricity, can depend on characteristics of the actuator. For example, for smaller form factor hard disk drives utilizing smaller actuators having less rotational inertia, more angular rotation may be desired. It is possible that such increased angular rotation can be accomplished with the same or less radial displacement of the head because of the reduced length of the arm. The minimum amplitude can be calibrated for each drive by taking open-loop gain measurements for different amplitudes of motion and choosing an amplitude sufficient to produce a relatively linear dynamic response at low frequencies. FIG. 4 is a hypothetical example of the gain of an actuator following different amplitudes of motion at different frequencies of oscillation. As the amplitude of oscillation increases and more motion is incorporated, the curve shifts such that the gain is higher at lower frequencies. For example, an amplitude of oscillation equivalent to twenty track widths may produce response curve 492 , while an amplitude of oscillation equivalent to four track widths may produce response curve 494 , and an amplitude of oscillation equivalent to one track width may produce response curve 496 . The more motion incorporated into the actuator, the higher the gain at lower frequencies. By incorporating twice-around, as shown in FIGS. 3A and B, the required amplitude may be reduced. [0025] In an alternative embodiment, a range of response curves as shown in FIG. 4 may be produced for a given hard disk drive form factor, and an amplitude of motion maybe chosen that is not the minimum motion required for linear behavior for each individual drive, but some motion that produces linear behavior for a statistical percentage of drives produced incorporating variations in manufacturing tolerances. In such an embodiment, the optimal track eccentricity is the eccentricity that predictably produces the desired results. [0026] As shown in FIGS. 3A and B, the optimal track eccentricity will likely incorporate less movement of the actuator than the eccentricity in the master servo pattern introduced by the clearance of the disk and the hubs. The power dissipated in the voice coil motor for an actuator following a master servo pattern with a once-around on the order of 2 mils can be as much as 0.2 Watts. Incorporating less movement of the actuator can significantly reduce the power dissipated in the voice coil motor, improving battery lifetime in mobile devices. [0027] Further, self-writing servo patterns on additional surfaces allows heads over different surfaces to be positioned over the same tracks, thereby eliminating delays when switching between heads. A hard disk drive utilizing methods in accordance with this invention will likely have improved performance over a hard disk drive having disks with servo patterns written by a media writer. Still further, the cost and time required to write servo patterns in the media writer is reduced by minimizing the surfaces written by the media writer. [0028] The methods described above are equally applicable to other data storage devices using moving actuators for positioning reading or writing devices; for example, a laser positioned over an optical medium, or an atomic probe positioned over a polysilicon substrate. The methods are not intended to be limited to hard disk drives technology, but are meant to be applied to any technology potentially impacted by frictional effects in actuator movement. [0029] The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to one of ordinary skill in the relevant arts. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalence.

Methods in accordance with the present invention can be applied to reduce frictional effects in a bearing of a rotary actuator on the motion dynamics of the rotary actuator. In one such method a disk having a first magnetic servo pattern on a surface written, for example, by a media writer, is rotated at a first frequency. The first magnetic servo pattern is read using a head. A second magnetic servo pattern based on the first magnetic servo pattern can be written to the surface by the head such that the second magnetic servo pattern is defined by the oscillation of the head at a second frequency. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

[0001] This invention claims the benefit of U.S. Provisional Application No. 60/274,612 filed Mar. 12, 2001. FIELD OF THE INVENTION [0002] This invention relates to communications systems and more particularly to the network management of communications systems involving switched optical networks. BACKGROUND [0003] In a switched optical network, typically, two neighboring nodes are physically connected by a bundle of optical fibers. At each node, each optical fiber within the bundle is identified as a port and assigned a unique port number. When two nodes are interconnected by optical fibers, it is necessary to make sure that the ports in one node are mapped to the ports in the other node as required. There is a possibility that some optical fibers are incorrectly connected to the wrong ports. It is also possible that there are some connection failures or faults. Accordingly there is a need for a system to automatically discover fiber connections in a switched optical network. Also, the discovery mechanism can, preferably, provide a diagnostic function. SUMMARY OF THE INVENTION [0004] The present invention provides an apparatus and method for automatically discovering port mapping. It can also be used as a diagnostic method to find faulty connections and channels. In the following description it is assumed that each node has a switch that can connect any ingress port to any egress port in the node. The system employs a handshaking protocol comprising a series of discovery and acknowledgement messages. Additionally, once the ports have established connectively, performance testing can determine the quality of the connection. [0005] According to a broad aspect of the invention there is provided a handshaking protocol to automatically discover fiber connections in a switched optical network and to provide diagnostics for fault connections on two neighboring optical nodes. BRIEF DESCRIPTION OF THE DRAWINGS [0006] The invention will now be described in greater detail with reference to the attached drawings wherein: [0007] [0007]FIG. 1 is a diagram of two optical nodes connected by a bundle of optical fibers; [0008] [0008]FIG. 2 illustrates a handshaking sequence; [0009] [0009]FIG. 3 is a flow diagram of the algorithm implemented on the receiving node; [0010] [0010]FIG. 4 is a flow diagram of the algorithm implemented on the sending node; [0011] [0011]FIG. 5 illustrates the message format for connect, reply and confirmation; [0012] [0012]FIG. 6 is a diagram of two optical nodes connected with a bundle of optical fibers using a Bit Error Rate Test Set (BERTS) to determine quality of the connection; and [0013] [0013]FIG. 7 is a diagram of two optical nodes driven by a specific Synchronous Optical Network (SONET) payload to determine the quality of the connection. DETAILED DESCRIPTION OF THE INVENTION [0014] In a switched optical network as contemplated by the present invention, two neighboring nodes are physically connected by a bundle of optical fibers. At each node, individual fibers are identified as a port and are assigned a port number. It is, of course, desirable to make sure that each port in one node is mapped to a connected port in the other node. [0015] [0015]FIG. 1 shows the basic concept of two nodes α and β connected by a bundle of fibers. Each node has several ingress ports and several egress ports, numbered 1 , 2 , 3 , 4 , A, B, C and D in FIG. 1. In this exemplary embodiment two ingress ports and two egress ports are shown for each node. It is. to be understood that in a practical implementation there will be many of each type of nodes. It is possible that an ingress port is paired with an egress port, and the two ports are assigned to the same port number. However the invention is independent in relation to the numbering scheme as long as the scheme can uniquely identify each port. [0016] Each egress port is physically connected to an ingress port of its neighboring node by an optical fiber. In the following discussion these ports are known as a Connection Port Pair (CPP). The discovery function, according to the invention, is to find the CPP pair for each port in a node. In the invention, port-mapping discovery is performed by exchanging Connection Discovery Messages (CDM) between the two CPP ports. [0017] In a Wavelength Division Multiplex (WDM) system, there may be multiple wavelengths transported through a single fiber. However, to discover the mapping for each CPP, only one wavelength is needed for exchanging CDMs. A default wavelength is defined and agreed upon by all nodes for exchanging the CDMs. Normally the longest wavelength is chosen and is called a CDM channel. [0018] The connection discovery process is triggered by an operator. The operator may initiate the discovery process for all the fiber ports, or only some specified ports inside the node. Once the process starts, the node begins to send the CDMs to all or some of its specified egress port using the CDM channels. Additionally, each node has a receiver that is connected to each of its specified ingress ports to wait for a CDM on the CDM channels. A rotation or scanning mechanism to scan all specified ingress and egress ports is described later. [0019] The CDM format includes the node name and the sending port number. Once a node receives a CDM, it embeds its node name, receiving port and reply or send port numbers, together with the originator's sending port number into the reply CDM and sends back the reply message. When this reply message reaches the original sender, the original sender knows which pair of the fibers is connected to it. It then sends back the reply CDM through its original sending port. This reply CDM embeds additional receiving port number information. When the other node receives this CDM, it knows which pair of the fibers is connecting to it as well. It then sends back a reply CDM to the sender to let the sender know that it knows the connections. The original sender replies to this CDM to let the original receiver know that it also knows the connections. The receiver then sends back a reply CDM to finish the handshaking procedure. [0020] The detailed handshaking algorithm and the message format will now be described. [0021] 1. The Handshaking Protocol [0022] Each node sends and receives the CDMs by connecting the spare monitoring channels to its egress or ingress ports via its switching fabric. The sending unit sends out the CDMs to each of its specified egress port and the receiver unit monitors the reply CDMs on each of its specified ingress ports. As an example, the handshaking algorithm for the system in FIG. 1 may work as following: [0023] 1) Sender α: sends out α 1000 through port 1 , which means the message comes from node α port 1 searching for its connected port. [0024] 2) Receiver β: receives α 1000 on port A. It knows that its port A is connected to port 1 of the node α. [0025] 3) Sender β: sends out βC 0 A 1 through port C. [0026] 4) Receive α: receives βC 0 A 1 from port 3 . Node α then knows that its port 1 is connected to port A of the node β and its port 3 is connected to port C of the node β. [0027] 5) Sender α: sends α 1 A 3 C through port 1 to node β. [0028] 6) Receiver β:receives α 1 A 3 C from port A. Node β then knows that its port A is connected to port 1 of the node α and its port C is connected to port 3 of the node α. It also knows that the node α already knows these connections. [0029] 7) Sender β: sends out βC 3 A 1 through port C to node α. [0030] 8) Receiver α: receives βC 3 A 1 from port 3 . Node α then knows that node β knows the connection as well. [0031] 9) Sender α: sends α 1 A 3 C through port 1 to node β for confirmation. [0032] A) Receiver β: receives α 1 A 3 C from port A. Receiver β knows that node a is requiring confirmation. [0033] B) Sender β: sends out βC 3 A 1 through port C to node α for confirmation and updates node β's connection mapping table. [0034] C) Receiver α: receives βC 3 A 1 from port 3 , and updates node α's connection mapping table. [0035] To avoid missing CDMs, the sender at each node preferably scans each of its specified egress port at a relatively fast speed. On the other hand, the receiver at each node should scan each of its specified ingress port at a slower speed. At least the receiver should stay monitoring one ingress port until the sender has finished scanning all of its egress ports. [0036] Once a receiver receives a CDM, the node should stop scanning the egress port to send CDMs. It should focus on replying to the CDM. On the other hand, once a sender receives a reply CDM, it should stop scanning and focus on dealing with this reply CDM until a connection is confirmed or timed out. [0037] If in step 6 ) above the receiver β cannot obtain the acknowledgement CDM from node α, it knows that the reply channel has something wrong. Node β should choose another egress port to send out an error message to node α. It should also raise an alarm showing this egress port error. [0038] If in step 4 ) the receiver a cannot receive a reply CDM after a certain amount of time, it should raise an alarm showing the connection error. [0039] [0039]FIG. 2 shows the handshaking algorithm. The algorithm can be summarized using the flowcharts shown in FIGS. 3 and 4. Both the sending and receiving algorithms may run on the two neighboring nodes. Once a node is receiving a CDM, it will focus on the receiving algorithm and its peer node should focus on the sending algorithm. The node administrators/ operators may also initiate one node to run the sending algorithm and the other one to run the receiving algorithm. [0040] Once connectivity has been established, performance testing can be initiated to determine the quality of the connection. FIG. 6 shows a Bit Error Rate Test Set (BERTS) 61 , either internal or external, connected to Node β 63 . The test pattern is routed through the node to an output port, in this case “D”. The test pattern travels down the fiber 64 to the port on Node α 65 , in this case “4”. Node α 65 loops the signal back to one of its output ports, in this case “1”, across the optical fiber 66 to Node β 63 , in this case, port “A”. The test pattern is routed through Node β back to the BERTS 61 . The BERTS can determine the error rate of the looped back signal and indicate to the user if there is a problem with one of the components (Transmitter, Fiber, Receiver) the connection path. [0041] Alternately a specific Synchronous Optical Network (SONET) payload can be used to determine the quality of the connection. FIG. 7 shows an all 1 's Line Alarm Indication Signal (AIS) 71 being multiplexed 73 with the SONET overhead and Line Bit Interleaved Parity 8 (BIP-8) 72 . The resulting data pattern is scrambled in a 2 7 -1 scrambler 74 . The scrambled data can optionally have Forward Error Correction (FEC) added through a 1:2 Demultiplexer (Demux) 75 , 1:2 Multiplexer (Mux) 78 and a FEC Encoder 76 . Errors can be injected 77 into the FEC. The SONET Synchronous Transport Signal 48 (STS-48) is connected to Node β 79 . The test pattern is routed through the node to an output port, in this case “D”. The test pattern travels down the fiber 712 to the port on Node α 711 , in this case “4”. Node α 711 loops the signal back to one of its output ports, in this case “1”, across the optical fiber 710 to Node β 79 , in this case, port “A”. The test pattern is routed through Node β 79 . Optionally, FEC coding can be decoded and FEC errors detected through a 1:2 Demultiplexer (Demux) 713 , 1:2 Multiplexer (Mux) 715 and a FEC Decoder 714 . The SONET frame is then Frame and Byte Aligned 716 and the Bit Error Rate (BER) detected through errors in the Line BIP-8 717 . This can determine the error rate of the looped back signal and indicate to the user if there is a problem with one of the components (Transmitter, Fiber, Receiver) the connection path. Line BIP-8 is a standard method of error detection in a SONET network. [0042] [0042] 2 . Connect Discovery Message (CDM) format [0043] [0043]FIG. 5 shows the message format for the connect requirement, reply and confirmation. The definition of each field is described as following: [0044] [0044] 1 . Synchronization header. [0045] [0045] 2 . Message type (e.g. discovery, reply, acknowledgement, confirmation, testing, error). [0046] [0046] 3 . Node name which is sending this message. [0047] [0047] 4 . Egress port number which is sending this message. [0048] [0048] 5 . Ingress port number who should receive this message. 0 means do not know. [0049] [0049] 6 . Ingress port number on the sending node which should receive the reply message. 0 means do not know. [0050] [0050] 7 . Egress port number which should send back reply message. 0 means do not know. [0051] [0051] 8 . Error checking field. [0052] The following possible variation is contemplated by the invention: [0053] The relationship of the two connected optical nodes may be varied such that the two nodes may run the same algorithm or one node may act as the master and the other node as slave. [0054] A particular advantage of the invention is that it provides automatic discovery and diagnostics, and that it automatically provides performance testing between the two nodes. [0055] While particular embodiments of the invention have been described and illustrated it will be apparent to one skilled in the art that numerous changes can be made without departing from the basic concept. It is to be understood that such changes will fall within the full scope of the invention as defined by the appended claims.

The invention proposes an apparatus and method to automatically discover port mapping between neighboring optical nodes in a switched optical network. It can also be used as a diagnostic method to find faulty connections and channels. It is assumed that each node has a switch that can connect any ingress port to any egress port in the node.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to the art of sporting balls thrown or rolled by hand and more particularly to bowling balls. 2. Description of the Related Art Many games and sports popularly enjoyed by enthusiasts require the use of a hand-held ball which is rolled or thrown. Among these games, one of the more popular is that of bowling. In bowling, one rolls a round ball toward a number of pins, with the object being to knock down as many pins as possible. The player knocking down the most pins obtains the highest score and thereby wins the bowling game. The bowling ball which is in popular use in this country must meet rigid standards promulgated by the American Bowling Congress. Among these standards is the requirement that the weight of the bowling ball must not exceed sixteen pounds and must not differ more than one ounce from side to side, and must not differ more than three ounces top to bottom. Further, the outside diameter of the bowling ball must be between 8.550 and 8.59 inches. The bowling ball is commonly drilled to provide a grip for the bowler. Conventional grips include the two hole and three hole grip. A two hole grip accommodates the thumb and middle finger of the bowler while a three hole grip accommodates the thumb, ring finger, and middle finger of the bowler. In a three hole grip, the holes for the ring finger and middle finger may be drilled to a shallow depth (i.e., to the first knuckle) to provide a fingertip grip or more deeply (i.e., to the second knuckle) to provide a conventional grip. Alternately, grips for which the fingers are inserted to intermediate positions between the first and second knuckle are referred to as semi-fingertip grips. The drilling of holes in the ball necessarily removes material from the ball. This creates an unbalanced condition in what would otherwise be a homogeneous bowling ball of constant weight density throughout. Various methods and apparatuses have been proposed in the prior art to compensate for the weight removed by drilling finger and thumb holes. The majority of prior designs endeavored to statically balance the bowling ball by compensating for the weight removed by the finger and thumb holes. In at least one patent, namely U.S. Pat. No. 4,320,899 to Salvino which is incorporated herein by reference, weight blocks are positioned in the bowling ball to dynamically balance the bowling ball. A bowling ball that is dynamically unbalanced will wobble as it rolls down the bowling lane. Such a dynamically unbalanced bowling ball will make it more difficult for the bowler to control, and therefore more difficult for him to consistently obtain high scores. Another impediment to consistent high scoring is the deflection of the bowling ball's path after it impacts the first bowling pin. In the case of an accurately thrown bowling ball, the bowling ball will impact the pocket (i.e., the number 1 and number 3 Pins for a right-handed bowler and number 1 and number 2 for a left-handed bowler) and begin crashing into secondary and tertiary rows of pins. It is advantageous for the bowling ball to deflect as little as possible from these primary and secondary impacts so that the ball will continue to follow its intended arc. It is a general object of this invention to provide a bowling ball which includes weight on the spin axis of the bowling ball having certain properties and positions relative to the spin axis so that the stability of the ball as it spins down the lane, as well as the arc of the ball's trajectory, are improved to provide consistently high scores for the skilled bowler. SUMMARY OF THE INVENTION In accordance with the present invention, a new and improved bowling ball is provided which features weighting means on the spin axis of the bowling ball. More particularly, in accordance with the invention, a bowling ball has a center and when spinning has a ball track plane and a spin axis. The spin axis is a line perpendicular to the ball track plane. The bowling ball comprises a core, a cover surrounding the core and having an outer surface, and weighting means for increasing the weight density of the bowling ball along the spin axis. In accordance with another aspect of the invention, the core is of substantially equal weight density throughout. According to another aspect of the invention, the cover is of substantially equal weight density throughout. According to another aspect of the invention, the weighting means is a weight block placed within the core on the spin axis. According to another aspect of the invention, the weighting means is a weight placement within the core on the spin axis. According to another aspect of the invention, the weighting means is a rod whose centerline is coincident with the spin axis, the rod having a homogeneous weight density distribution so that one-half of the rod weighs substantially the same as the other half of the rod. Accordingly to another aspect of the invention, the weighting means for increasing the weight density of the bowling ball along the spin axis reduces the bowling ball's movement of inertia about the spin axis. According to a still further aspect of the invention, the bowling ball features biasing means for biasing the weight density of the ball along the spin axis. The biasing means is located on the spin axis. According to another aspect of the invention, the biasing means is a weight block placed within the core between the center of the bowling ball and the cover. According to another aspect of the invention, a second weight block is located on the spin axis on the opposite side of the center than the first weight block. According to another aspect of the invention, the biasing means is a rod whose centerline is coincident with the spin axis and which has a heterogeneous weight density distribution so that one half of the rod weighs more than the other half of the rod. According to another aspect of the invention, the biasing means is operatively adapted for increasing the precession of the bowling ball. According to a still further aspect of the invention, the bowling ball features a pair of weight blocks disposed within the bowling ball inwardly of the outer surface of the cover. One of the weight blocks is positioned to be intersected by at least one finger hole when drilled into the bowling ball. The other of the weight blocks is positioned to be intersected by a thumb hole when drilled into the bowling ball. The size and location of the weight blocks is such that there is no concentrated residual weight provided by the weight blocks after drilling. Further, the weight density of the core, the weight density of the cover, and the shape and weight density of the weight blocks are such that after drilling, all axes of the bowling ball may be a spin axis in which the bowling ball's moments of inertia about axes aligned with the spin axis are approximately equal and the products of inertia for all axes perpendicular to the spin axis are small, thereby producing a stable trajectory for the bowling ball as it slides and rolls down the bowling lane. One advantage of the present invention is the provision of weighting means on the spin axis which tends to lower the bowling ball's moment of inertia about the spin axis. This results in a more stable trajectory and a lessening of dynamic imbalance during the spinning phase of the ball's trajectory down the bowling lane. Another advantage of the present invention that is due to the lower moment of inertia about the bowling ball's spin axis is increased precession. Because the bowling ball's moment of inertia about the spin axis is lower, due to the concentration of weight along the spin axis, the physical phenomenon of precession is more operative. The precession causes the radius of the curvature of the bowling ball's arc to be smaller, causing the ball to "hook" more and to hit the pocket with more advantageous results. Another advantage of the invention is the provision of a biasing means whereby the trajectory and curvature of the ball's arc may be modified by intentionally creating a state of imbalance along the spin axis. By placing the heavier side of the spin axis on the positive side of the bowling ball, the curvature of the arc for a right-handed bowler is smaller, causing the ball to hook more and hit the pocket with more advantageous results. Another advantage of the present invention is the provision of weight blocks to compensate for the weight removed by the drilling of the thumb and finger holes. The provision of these weight blocks restores the ball to a dynamically balanced condition as described in U.S. Pat. No. 4,320,899 to Salvino. Still another advantage of the invention is the provision of a weight block design which enables the bowling ball of this invention to be drilled for either a right-handed or left-handed bowler. Still another benefits and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: FIG. 1 is a schematic plan view of a bowling ball with a ball track; FIG. 2 is a schematic, perspective, partially cross-sectional view of a bowling ball and weight blocks according to the present invention; FIG. 3 is a schematic plan view of weight blocks according to the present invention; FIG. 4 is a schematic view of a weight block according to the present invention; FIG. 5 is a schematic, perspective, partially cross-sectional view of a bowling ball according to the present invention which features weight blocks on the spin axis; FIG. 6 is a schematic, perspective, partially cross-sectional view of a bowling ball according to the present invention which features weight blocks on the spin axis as well as weight blocks to compensate for the finger holes and thumb holes; FIG. 7 is a schematic, perspective, view of the forces and moments which act on the bowling ball as it rolls and slides down the lane; FIG. 8 is a schematic plan view of the forces and moments which act on the bowling ball as it rolls and slides down the lane; FIG. 9 is a schematic side view of the forces and moments which act on the bowling ball as it rolls and slides down the lane; FIG. 10 is a schematic, perspective, partially cross-sectional view of a bowling ball according to the present invention which features a rod on the spin axis; FIG. 11 is a schematic, perspective view of a bowling ball according to another embodiment of the invention; FIG. 12 is a schematic, perspective view of a bowling ball according to another embodiment of the invention; FIG. 13 is a schematic, perspective view of a bowling ball according to another embodiment of the invention; FIG. 14 is a schematic, perspective view of a bowling ball according to another embodiment of the invention; and, FIG. 15 is a schematic, perspective view of a bowling ball according to another embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, FIG. 1 shows a typical bowling ball B which features three drilled holes. A midplane MP of the bowling ball passes through the center of a thumb hole 10 and bisects a line segment between the center of a middle finger hole 12 and a ring finger hole 14. For a right-handed bowler, the area on the right half of the midplane is called the positive side of the ball while the area on the left side of the midplane is called the negative side of the ball. In the case where a consistent bowler uses the same bowling ball for a length of time, a distinguishing wear pattern called a ball track 20 will begin to appear. Because the ball is spinning as it leaves the bowler's hand, and because lanes are generally oiled, the ball tends to slide along the lane for a length of time before friction between the ball and the lane causes the ball to begin rolling down the lane. The sliding of the ball relative to the lane causes the wear marks known as the ball track 20. The width of the ball track can vary due to factors such as the consistency of the bowler and the dynamic stability of the bowling ball. For discussion purposes, the ball track can be considered as being in a plane which is centered in the middle of the ball track. Perpendicular to the plane containing the ball track 20 is a line called the spin axis SA. When the ball is spinning and sliding down the lane, it revolves around the spin axis SA. Analysis of the ball track 20 reveals certain facts to the experienced bowler. Bowlers generally use one of four primary delivery styles, each of which has a distinctive ball track. In a "full roller" delivery, the ball track 20 is located on the "great circle" of the bowling ball. The great circle is a term referring to a circle on the surface of the bowling ball which is of maximum diameter. Another variety of the full roller is known as a "full roller outside fingers and thumb". In this case, the ball track 20 is located not on a great circle, but on the largest circle possible which falls outside the finger and thumb holes. The third primary delivery style is a "3/4 roller". In this case, the ball track 20 has a smaller diameter of than that of the full roller or the full roller outside fingers and thumb. The final delivery style is the "spinner". In a spinner delivery, the ball track 20 is of relatively small diameter. In each of the four delivery styles, the spin axis SA is perpendicular to the plane containing the ball track 20. The dynamic stability of a bowling ball B can be inferred by the width of the ball track 20. In a bowling ball which is dynamically stable, the ball track 20 tends to be relatively narrow. However, in a bowling ball that is dynamically unstable, the ball track 20 tends to be flared. The dynamics of the ball's motion as it travels down the lane is described in FIGS. 7-9. When the ball B is delivered from the bowler's hand, the ball is spinning about the spin axis SA, and sliding down the lane 50. The ball is not yet rolling. At some point down the lane 50, the ball's motion begins to change from spinning and sliding to rolling. For purposes of this discussion, this part of the ball's motion will be called "transition". During transition the bowling ball is both spinning and rolling. During this time, the bowling ball is revolving about two axes simultaneously. Whenever a body rotates about two axes, motion about a third axis results. This motion about the third axis is called "precession". With continuing reference to FIGS. 7-9, the bowling ball's motion may be conveniently described with resort to three axes. The first axis, denoted SA, is the spin axis of the bowling ball. The second axis, denoted R, passes through the center of the bowling ball and is parallel to the lane surface. This is the axis about which the bowling ball revolves as it rolls. The third axis, denoted V, is a vertical axis passing through the center of the bowling ball which is perpendicular to the rolling axis R. During transition, the bowling ball B is spinning and sliding on the lane surface. The direction of the spin for a right-hand bowler is illustrated by use of arrows S 1 and S 2 . It should be understood that the directions of S 1 and S 2 are parallel to the plane of the ball track 20. During transition, the bowling ball is also beginning to roll down the lane. The rolling revolves a revolution of the bowling ball about its rolling axis R. This motion is illustrated by way of arrows R 1 and R 2 . As discussed above, because the bowling ball is rotating about two axes simultaneously, namely SA and R, it will also rotate about a third axis due to precession. Precession acts on the ball in the direction of arrow P 1 and causes the trajectory of the bowling ball to be more curved. This smaller radius of curvature enables the ball to "hook" into the pocket, resulting in greater pin fall and higher scores. With reference to FIG. 2, there is disclosed a bowling ball according to the present invention with a pair of weight blocks 22, 24. The bowling ball comprises a core 26 surrounded by a cover 28. The core is preferably made of a material with a homogeneous weight density; in other words, portions of the core having equivalent volumes also have equivalent weights. In the preferred embodiment, the core is made of polyester. The cover 28 is approximately 1/4 inch thick and is also made of a material having a homogeneous weight density. In the preferred embodiment, the cover is made of polyester. With reference to FIGS. 11 and 12, alternate embodiments of the invention can feature smaller diameter cores 26 with correspondingly thicker covers 28. The weight blocks 22, 24 are located within an outer surface 32 of the cover 28. In the preferred embodiment, the weight blocks 22, 24 are located near the inside surface 34 of the cover 28 and the core 26. In the preferred embodiment, the weight blocks are curved, as shown in FIG. 4, so that the weight blocks will fit against an inside surface 34 of the cover 28. In the preferred embodiment, the weight blocks are positioned as shown in FIG. 3 so that they are symmetrical about a line 3--3 passing between the two blocks. Line 3--3 is parallel to the major axis of each of the weight blocks. By making the blocks symmetrical, the bowling ball B can have a weight bias from side to side and still be drilled for either a right-handed or left-handed bowler. For example, FIG. 3 shows weight block 22 drilled for the middle finger hole 12 and the ring finger hole 14. Correspondingly, the weight block 24 is drilled for the thumb hole 10. Assuming this relationship is for a right-handed bowler, the same bowling ball could be drilled for use by a left-handed bowler by drilling finger holes 12, 14 in block 24 and thumb hole 10 in block 22. The advantages of a biased weighted bowling ball from left to right will be discussed later in the specification. The advantages inherent in the use of weight blocks 22, 24 are detailed in U.S. Pat. No. 4,320,899 which is incorporated here by reference. For purposes of this discussion, it is important to know that weight blocks 22, 24 improve the dynamic stability of the bowling ball, in that the products of inertia about axes perpendicular to the spin axis become vanishingly small. With reference to FIG. 5, a bowling ball B is shown which features weight blocks 40, 42 on the spin axis SA. Alternate embodiments (not shown) of the weight blocks include one weight block positioned between the center of the bowling ball and the outer surface of the cover 28, a plurality of weight blocks evenly distributed on either side of the center of the ball, and a plurality of weight blocks intentionally biased toward one side of the center of the ball. With reference to FIG. 6, the weight blocks 40,42 on the spin axis SA are combined with weight blocks 22, 24 in the preferred embodiment. With reference to FIG. 10, in another embodiment, a rod 46 is located in the interior of the ball so that the centerline of the rod 46 is coincident with the spin axis SA. The rod 46 may either be homogeneous, having an equal weight density along the length of the rod 46, or heterogeneous, having a different weight density on one side of the center of the ball B than the rod 46 has on the other side of the center. With reference to FIG. 11, one embodiment feature a smaller core 26, a correspondingly thicker cover 28, a rod 46 along the spin axis 5A, and a weight block 64 which occupies the top portion of the core 26. In another embodiment shown in FIG. 12, the weight block 64 is above the core 26 and located near the top of the cover 28. With reference to FIGS. 13-15, alternate embodiments of the invention feature bias weights 60, 62, 64. These bias weight generally extend from one side of the ball's geometric center to the outer surface 32 of the cover 28. The bias weights 60,62, 64 may take the form of spherical weight 60, a rectangular column 62, or spokes 64 emanating from the spin axis 5A. In the preferred embodiment, one weight block 40, 42 is located on each side of the center of the ball. One of the weight blocks weighs one ounce more than the other weight block. This weight differential is the maximum weight differential allowed by the American Bowling Congress. It is the preferred embodiment because of the precession it puts into the arc of the ball's path. The invention has been described with reference to a preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

A bowling ball comprises a core, a cover surrounding the core, and a weighting rod for increasing the weight density of the bowling ball along the spin axis, thereby reducing the bowling balls moment of inertia about the spin axis. To modify the trajectory of the ball's hook, or arc, on the bowling alley lane, the rod's weight may be offset so that one side of the bowling ball is heavier than the other side. The biased nature of the weight causes the bowling ball to develop precession, and improve the hooking nature of the trajectory.

RELATED APPLICATIONS [0001] This application is a continuation application of U.S. application Ser. No. 09/910,422, filed Jul. 20, 2001, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 60/220,018, filed Jul. 21, 2000, the disclosures of which are hereby incorporated by reference in their entireties herein. [0002] A co-pending and co-owned patent application with application Ser. No. 09/910,477, filed on Jul. 20, 2001, commonly owned and filed on the same day as the present application, is hereby incorporated herein in its entirety by reference thereto. BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention generally relates to electronics. In particular, the present invention relates to communications systems. [0005] 2. Description of the Related Art [0006] The rapid commoditization of the cellular, personal communication service (PCS) and wireless industries has resulted in the emergence of new digital radio standards, which support the emergence of high user bandwidth requirements. For example, third generation (3G) digital wide-band code division multiple access (W-CDMA) and Enhanced Data GSM (Group System for Mobile Communications) Environment (EDGE) air interface standards exploit signal processing techniques that can generate radio and baseband waveforms with a relatively high peak power to average power ratio. [0007] The signals amplified by a wireless base station include multiple signals, which are combined to a multi-bearer waveform. The number of voice and data connections represented within the multi-bearer waveform can vary randomly and vary over time. Occasionally, the information sources that are combined to form the multi-bearer waveform can co-align and generate a relatively large instantaneous signal peak or crest. In one example, the relatively large instantaneous signal peak is about 10 times higher in power than a nominal or average output level. [0008] In practice, the alignment that generates a relatively large instantaneous signal peak occurs with a relatively low probability. Despite the relatively low probability, however, the dynamic range of the entire signal processing chain of a base station should be sufficient to handle the large instantaneous signal peak in order to transmit the signal without error. [0009] One conventional approach is to design the base station to accommodate the relatively rare, but large, signal peak. As a result, the base station is significantly overdesigned, which results in a significant increase to the cost of the base station. In particular, the cost and the size of the radio frequency (RF) amplifier of the base station are deleteriously affected. For example, such an approach disadvantageously lowers the efficiency of the RF amplifier, as a higher powered RF amplifier will waste significantly larger amounts of power for biases and the like. Further, the extra power dissipation is correspondingly dissipated with larger and more costly heat management techniques. [0010] In addition, the relatively large dynamic range imposed upon the base station by the relatively large signal peak typically requires that the upconversion circuitry, the digital to analog converters, the digital signal processing circuits, and the like also accommodate the relatively large dynamic range. [0011] In another conventional approach, the signal waveform is hard limited to reduce the dynamic range of the relatively rare signal peaks. This allows a relatively lower power RF transmitter to be used to transmit the signal, which allows the RF transmitter to operate with relatively larger efficiency. However, conventional hard limiting techniques are impractical because hard limiting generates distortion energy, which causes interference in adjacent channels. SUMMARY OF THE INVENTION [0012] Embodiments of the present invention include apparatus and methods that overcome the disadvantages of the prior art by manipulating a multibearer waveform, which can include single carrier or multiple carrier waveforms that reduce the peak to average ratio of the multibearer waveform. Advantageously, embodiments of the present invention allow radio frequency (RF) base stations to be more efficient, compact, and lower in cost than conventional base stations. [0013] Embodiments of the invention permit significant reduction to the cost to provision digital and analog signal processing chains in communication systems. Embodiments of the invention may be applied to a variety of communications systems including both wire and wireless communications systems such as cellular, personal communications service (PCS), local multipoint distribution systems (LMDS), and satellite systems. [0014] One embodiment of the invention includes a predictive weight generator that reduces an amount of waveshaping processing applied to a plurality of input symbol streams by a waveshaping circuit. The predictive weight generator includes pulse-shaping filter emulation circuits that receive the plurality of input symbol streams. A pulse-shaping filter emulation circuit can be constructed from a pulse-shaping circuit. The predictive weight generator further includes mixers coupled to the pulse-shaping filter emulation circuits and coupled to digital numerically controlled oscillators that upconvert actual outputs of actual pulse-shaping filters for the input symbol streams. The outputs of the mixers are summed by a summing circuit to simulate a composite signal and to thereby predict an amplitude of an actual composite signal. A comparator compares the predicted amplitude to a threshold level and provides weight value modifications to the waveshaping circuit in response to the comparison in real time. [0015] One embodiment of the invention includes a post-conditioning circuit that generates a de-cresting pulse that can decrease an amplitude of a signal peak of a composite multicarrier signal in real time. The composite multicarrier signal includes a plurality of input symbol streams that are pulse-shaped and frequency upconverted to a plurality of upconverted streams. The post-conditioning circuit includes a comparator, a weight generator, an impulse generator, a multiplier circuit, and a bandpass filter. [0016] The comparator compares the composite multicarrier signal to a predetermined threshold such that the comparator activates an output when the composite multicarrier signal exceeds the predetermined threshold. The weight generator receives the plurality of upconverted streams and phase information from a plurality of oscillators as inputs. The weight generator also receives carrier waveforms for the plurality of upconverted streams so that the weight generator can determine an upconverted stream's contribution to the composite multicarrier signal's signal peak. The weight generator calculates a weight value for the upconverted stream approximately proportionately to the upconverted stream's contribution to the composite multicarrier signal's signal peak. [0017] The impulse generator provides an impulse as an output in response to the output of the comparator. The impulse generator also controls a duration of the generated impulse in response to the output of the comparator. The multiplier circuit multiplies the weight value from the weight generator with the impulse from the impulse generator to generate a scaled impulse. The bandpass filter filters the scaled impulse to a frequency band that corresponds to the upconverted stream's allocated frequency band to generate the de-cresting pulse. [0018] In one embodiment, multiple pulses are injected to de-crest the composite multicarrier signal. The multiple pulses can advantageously prevent the injection of signal energy to unutilized adjacent channel allocations. [0019] One embodiment of the invention includes a pulse-shaping circuit that reduces a probability of an alignment in amplitude and phase of similar symbols in a plurality of input symbol streams. The plurality of input symbol streams are eventually upconverted and combined to a composite data stream and include at least a first input symbol stream and a second input symbol stream. Advantageously, a reduction in the probability of the alignment reduces a probability of a large signal crest in the composite data stream. [0020] The pulse-shaping circuit includes a plurality of pulse-shaping filters, which pulse-shape the plurality of input symbol streams to a corresponding plurality of baseband streams. The pulse shaping circuit further includes a plurality of multipliers, which upconvert the plurality of baseband streams to a plurality of upconverted streams, and a summing circuit that combines the upconverted streams to the composite signal. The pulse shaping circuit also includes a delay circuit in at least a first data path. The first data path is a path from an input symbol stream to the composite data stream. The delay circuit delays data in the first data path by a fraction of a symbol period relative to data in a second data path to stagger symbols in the symbol streams. [0021] One embodiment of the invention includes a composite waveform de-cresting circuit that digitally generates at least one de-cresting phase shift in real time that allows a composite multicarrier signal to be generated with a decrease in an amplitude of a signal peak. Advantageously, the circuit decreases the amplitude of the signal peak of the composite multicarrier signal without altering an amplitude of the plurality of input symbol streams. The circuit includes a computation circuit, a comparator, at least one impulse generator, and at least one phase shifter. [0022] The computation circuit receives the plurality of upconverted streams and a phase information from a plurality of oscillators that provide carrier waveforms for the plurality of upconverted streams. The computation circuit predicts a level in the composite multicarrier signal. The comparator compares the predicted level of the composite multicarrier signal from the computation circuit to a predetermined threshold and the comparator activates an output when the composite multicarrier signal exceeds the predetermined threshold. [0023] The weight generator receives the plurality of upconverted streams and a phase information from the plurality of oscillators that provide carrier waveforms for the plurality of upconverted streams. The weight generator calculates a weight value for an upconverted stream in the plurality of upconverted streams, where the weight value is approximately proportional to the upconverted stream's contribution to the predicted level of the composite multicarrier signal's signal peak. [0024] The impulse generator provides an impulse as an output in response to the output of the comparator. The impulse generator also controls a duration of the generated impulse in response to the output of the comparator. The multiplier circuit multiplies the weight value from the weight generator with the impulse from the impulse generator to generate a scaled impulse. The bandpass filter that filters the scaled impulse to a frequency band that corresponds to the upconverted stream's allocated frequency band to generate a de-cresting phase-shift control signal. The phase shifter modulates a relative phase of the upconverted stream in response to the de-cresting phase-shift control signal. BRIEF DESCRIPTION OF THE DRAWINGS [0025] These and other features of the invention will now be described with reference to the drawings summarized below. These drawings and the associated description are provided to illustrate preferred embodiments of the invention and are not intended to limit the scope of the invention. [0026] FIG. 1 illustrates a waveshaping circuit according to one embodiment of the present invention. [0027] FIG. 2 illustrates a complementary cumulative distribution function (CCDF) curve for an intrinsic W-CDMA multicarrier signal. [0028] FIG. 3 illustrates a multi-carrier waveshaping circuit according to one embodiment of the present invention. [0029] FIG. 4 illustrates a waveshaping circuit according to an embodiment of the present invention that adaptively modifies the waveshaping processing to fit predetermined criteria. [0030] FIG. 5 illustrates a preconditioning circuit according to an embodiment of the present invention. [0031] FIGS. 6 A-E illustrate an example of the operation of the preconditioning circuit shown in FIG. 5 . [0032] FIG. 7 graphically represents limiting with a relatively soft signal level threshold and limiting with a relatively hard signal level threshold. [0033] FIG. 8 illustrates another preconditioning circuit according to an embodiment of the present invention. [0034] FIG. 9 illustrates a waveshaping circuit according to an embodiment of the present invention. [0035] FIG. 10 consists of FIGS. 10A and 10B and illustrates a multicarrier de-cresting circuit according to an embodiment of the present invention. [0036] FIGS. 11 A-E illustrate an example of the operation of the multicarrier de-cresting circuit shown in FIG. 10 . [0037] FIGS. 12 A-C are power spectral density (PSD) plots of de-cresting with a single Gaussian pulse. [0038] FIGS. 13 A-E illustrate de-cresting with multiple Gaussian pulses. [0039] FIGS. 14A and 14B illustrate the results of a complementary frequency domain analysis of a multicarrier de-cresting circuit. [0040] FIG. 15 illustrates one embodiment of a de-cresting pulse generation circuit. [0041] FIG. 16 illustrates a pulse-shaping filter according to an embodiment of the present invention. [0042] FIG. 17 consists of FIGS. 17A and 17B illustrates a phase-modulating waveshaping circuit according to an embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0043] Although this invention will be described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art, including embodiments which do not provide all of the benefits and features set forth herein, are also within the scope of this invention. Accordingly, the scope of the present invention is defined only by reference to the appended claims. [0044] FIG. 1 illustrates a waveshaping circuit 100 according to one embodiment of the present invention. A waveshaping circuit can be adapted to shape either single data streams or multiple input streams with multiple baseband signals. The waveshaping circuit 100 shown in FIG. 1 is adapted to shape a single input data stream to a single shaped output data stream. Other embodiments that are adapted to shape and to combine multiple input signals to a shaped output data stream are described later in connection with FIGS. 3, 4 , 9 , 10 , 15 , 16 , and 17 . [0045] An input symbol stream 102 is applied as an input to the waveshaping circuit 100 . The input symbol stream 102 can include data for cellular telephone communications, data communications, and the like. The waveshaping circuit 100 generates an output sample stream 104 as an output. Advantageously, the output of the waveshaping circuit 100 has a lower dynamic range than the input symbol stream 102 . The lower dynamic range of the output sample stream 104 allows a base station to process and to amplify the output sample stream 104 with lower power and lower dynamic range components. [0046] The waveshaping circuit 100 includes a preconditioning stage 106 , a pulse-shaping and frequency translating circuit 108 , and a post-conditioning circuit 110 . The waveshaping circuit 100 can replace an upconversion circuit or portions of the waveshaping circuit 100 can be used to supplement existing upconversion circuits. [0047] The preconditioning stage 106 includes a preconditioning circuit 112 . In alternate embodiments, where multiple input baseband signals are shaped and combined, the preconditioning stage 106 can include multiple preconditioning circuits. The preconditioning circuit 112 applies nonlinear processing to the input symbol stream 102 on a symbol by symbol basis. In one embodiment, the preconditioning circuit 112 applies a soft nonlinear compression function, which severely compresses relatively extensive signal peaks and compresses relatively modest signal peaks into a predefined signal range. The output of the preconditioning circuit 112 is provided as an input to the pulse-shaping and frequency translating circuit 108 . At this point in the data flow, bandwidth expansion is not a concern since the output of the preconditioning circuit 112 exhibits a white spectral characteristic. Further details of the preconditioning circuit 112 are described later in connection with FIGS. 5, 6 , 7 , and 8 . [0048] The illustrated pulse-shaping and frequency translating circuit 108 includes a pulse-shaping filter 114 , a digital numerically controlled oscillator (NCO) 116 , and a mixer 118 . The pulse-shaping filter 114 maps the source bits of the output of the preconditioning circuit 112 to a baseband pulse. The output of the pulse-shaping filter 114 and an output of the digital NCO 116 are applied as inputs to the mixer 118 . In one embodiment of the waveshaping circuit 100 , the pulse-shaping and frequency translating circuit 108 is implemented with conventional components. [0049] In a conventional base station without waveshaping, a sequence of input modulation symbols is streamed into a pulse-shaping filter and to a frequency upconversion circuit. The modulation symbols usually exhibit a white frequency spectral density and it is not until the symbol rate is stepped up to the higher sample stream rate by the pulse-shaping filter that the new modulation sample stream is band-limited by the actions of the filter. The baseband sample stream output of the pulse-shaping filter can be shifted to a new digital carrier frequency by multiplication with the output of the digital NCO. The input symbol stream 102 often is a composite of many symbol streams drawn from a number of active voice and data users. Consequently, on occasion, these symbol streams linearly (vectorially) add up to a relatively large signal peak when relatively many users simultaneously transmit a similar or identical modulation symbol. [0050] The mere preconditioning of the input symbol stream 102 by the preconditioning circuit 112 does not adequately reduce peaks in the output of the mixer 118 due to Gibbs-type phenomena in the pulse-shaping filter 114 . The Gibbs-type phenomena re-introduces signal peaks to the signal stream as a natural consequence of filtering. [0051] In order to compensate for the signal peaks from the pulse-shaping filter 114 , the waveshaping circuit 100 includes the post-conditioning circuit 110 . The post-conditioning circuit 110 includes a pulse generator 120 and a summing circuit 122 . The pulse generator 120 detects signal peaks and introduces via the summing circuit 122 a band-limited Gaussian pulse that destructively interferes with peaks in the output of the mixer 118 to reduce the peaks in the output sample stream 104 . Although the destructive interference can temporarily undermine the waveform integrity of the output sample stream 104 , the post-conditioning circuit 110 advantageously limits the upper peak values of the output sample stream 104 to a relatively precise dynamic range. [0052] This transitory degradation in the integrity of the output sample stream 104 is tolerable, particularly in CDMA systems, because the introduced error energy is not de-spread in the signal recovery processing undertaken by the receiver. In one embodiment, the pulse generator 120 generates a Gaussian pulse or a family of Gaussian pulses to destructively interfere with the signal peaks in the output of the mixer 118 . Advantageously, the error energy of a Gaussian pulse or family of Gaussian pulses is equally spread among W-CDMA spreading codes. In addition to their spectral characteristic, Gaussian pulses can be generated relatively easily and with relatively low latency. In other embodiments, the pulse generator 120 uses other types of band-limited pulse shapes such as Blackman pulses, Hamming pulses, Square Root Raised Cosine (SRRC) pulses, Raised Cosine (RC) pulses, Sinc pulses and the like to destructively interfere with and reduce the signal peaks. Further details of the post-conditioning circuit 110 are described later in connection with FIGS. 10 to 17 . [0053] FIG. 2 illustrates a complementary cumulative distribution function (CCDF) curve for an intrinsic W-CDMA multicarrier signal. The W-CDMA multicarrier signal is a multi-bearer waveform that includes a time variant random number of data and voice connections which, on relatively rare occasions, can co-align and generate a relatively large instantaneous signal peak. Although the relatively high amplitude signal peaks are relatively rare, the probability of the occurrence of the relatively high amplitude signal peaks is non-zero and should be accommodated by RF transmitters, base stations, and the like. [0054] A horizontal axis 202 indicates output power relative to an average or mean power at 0 decibels (dB). A vertical axis 204 indicates the inverse probability (1−P) of the CCDF curve. The curves in FIG. 2 illustrate an example of the effects of peak power reduction by the destructive interference of a waveshaping circuit according to an embodiment of the present invention. [0055] A first curve 206 corresponds to a typical, i.e., without waveshaping processing, CCDF curve with 10 dB of input back-off (ibo) for an intrinsic W-CDMA multicarrier signal. The first curve 206 illustrates that without waveshaping processing, signal levels that exceed 5 dB above the average signal level occur with a non-zero probability. Although the probability of such signal peaks is relatively low, the entire transmitter, which includes digital processors, analog upconverters, and power amplifiers, should accommodate such signal peaks. [0056] A second curve 208 illustrates an example of the effects of waveshaping processing according to an embodiment of the present invention. The second curve 208 corresponds to a CCDF curve, where output signal peaks have been reduced through destructive interference by a waveshaping circuit to limit the signal peaks to a selected threshold. In the second curve 208 , the selected threshold is about 5 dB above the mean power. The selected threshold can be varied to correspond to a broad range of values. In one embodiment, the selected threshold is fixed in a waveform shaping circuit. In another embodiment, a waveform shaping circuit monitors the incoming data sequences and adaptively adjusts the circuit's behavior to match with predetermined criteria. The reduction in signal peaks provided by embodiments of the present invention advantageously allows signals to be transmitted with more efficiency and with lower power and lower cost RF amplifiers. [0057] FIG. 3 illustrates a multi-carrier waveshaping circuit 300 according to one embodiment of the present invention, where the multi-carrier waveshaping circuit 300 is adapted to reduce relatively high amplitude signal peaks in a multi-carrier W-CDMA application. It will be understood by one of ordinary skill in the art that the number of carriers can vary over a broad range. The illustrated multi-carrier waveshaping circuit 300 of FIG. 3 is shown with 3 carriers. [0058] The multi-carrier waveshaping circuit 300 receives a first input symbol stream 302 , a second input symbol stream 304 and a third input symbol stream 306 as inputs. The multi-carrier waveshaping circuit 300 generates an output sample stream 308 by pulse-shaping, upconverting, combining, and waveshaping the input symbol streams. [0059] The multi-carrier waveshaping circuit 300 includes a first preconditioning circuit 310 , a second preconditioning circuit 312 , a third preconditioning circuit 314 , a first pulse-shaping filter 316 , a second pulse-shaping filter 318 , a third pulse-shaping filter 320 , a first mixer 322 , a second mixer 324 , a third mixer 326 , a first digital numerically controlled oscillator (NCO) 328 , a second digital NCO 330 , a third digital NCO 332 , a post-conditioning pulse generator 348 , a first summing circuit 350 , a delay circuit 352 , and a second summing circuit 354 . [0060] The first preconditioning circuit 310 , the second preconditioning circuit 312 , and the third preconditioning circuit 314 receive as inputs and process the first input symbol stream 302 , the second input symbol stream 304 and the third input symbol stream 306 , respectively, such that the peak to average ratio of each independent baseband input channel stream of modulation symbols is constrained within an initial level. One embodiment of a preconditioning circuit according to the present invention is described in greater detail later in connection with FIGS. 5 and 8 . [0061] The outputs of the first preconditioning circuit 310 , the second preconditioning circuit 312 , and the third preconditioning circuit 314 , are applied as inputs to the first pulse-shaping filter 316 , the second pulse-shaping filter 318 , and the third pulse-shaping filter 320 , respectively, which map the inputs to baseband symbol streams. [0062] The baseband symbol streams are applied as inputs to the first mixer 322 , the second mixer 324 , and the third mixer 326 . The first mixer 322 , the second mixer 324 , and the third mixer 326 mix the symbol streams with a first output 340 , a second output 342 , and a third output 344 of the first digital NCO 328 , the second digital NCO 330 , and the third digital NCO 332 , respectively, to upconvert and to produce multiple streams of modulated channels. An output 334 of the first mixer 322 , an output 336 of the second mixer 324 , and an output 338 of the third mixer 326 are combined to a composite signal by the first summing circuit 350 . In addition, the outputs 334 , 336 , 338 constructively interfere and destructively interfere with each other when combined. The constructive interference and the destructive interference can occur even where the signals that are combined are individually pre-compensated to limit high-amplitude signal peaks. As a result, the composite signal exhibits an even greater dynamic range with a significantly greater peak to average power ratio than a single modulated channel. [0063] Embodiments of the present invention advantageously compensate for the relatively high-amplitude signal peaks in composite signals caused by constructive interference. In addition, embodiments of the present invention compensate for the relatively high-amplitude signal peaks with relatively little, if any, injection of signal energy to adjacent channel allocations. One embodiment that further advantageously detects destructive interference to at least partially disable the pre-compensation and the post-compensation applied to the input signals and to the composite signal is described later in connection with FIG. 9 . [0064] The post-conditioning pulse generator 348 compensates for the relatively high-amplitude signal peaks in the composite signal by generating multiple Gaussian pulses, which are selected to destructively interfere with relatively high-amplitude signal peaks in the composite signal. The post-conditioning pulse generator 348 receives as inputs the outputs 334 , 336 , 338 and analyzes the phase, frequency and amplitude of each respective channel carrier stream. This information permits the Gaussian pulse generator control to independently weigh a family of Gaussian pulses and to generate individual Gaussian pulses for each channel carrier stream, where each pulse is centered at the respective carrier frequency with a phase and amplitude selected to proportionally cancel the particular channel's contribution to the instantaneous composite signal's peak. The approach of utilizing multiple pulses is advantageous because signal energy is not injected into non-utilized adjacent channel allocations. Injection of signal energy to non-utilized adjacent channel allocations can undesirably interfere with other transmitters and systems. Further details of the post-conditioning pulse generator 348 are described later in connection with FIGS. 10-17 . [0065] The family of Gaussian pulses generated by the post-conditioning pulse generator 348 is applied as an input to the second summing circuit 354 . The second summing circuit 354 sums the family of Gaussian pulses with an output of the delay circuit 352 . The delay circuit 352 delays the composite signal from the first summing circuit 350 to align the composite signal with the Gaussian pulses generated by the post-conditioning pulse generator 348 . In one embodiment, the delay circuit 352 delays the composite signal by the latency time associated with the post-conditioning pulse generator 348 minus the latency time associated with the first summing circuit 350 . The delay circuit 352 can be implemented with cascaded flip-flops, delay lines, and the like. The second summing circuit 354 generates the output sample stream 308 as an output. [0066] Waveshaping according to one embodiment of the present invention includes three processes: input preconditioning, pulse-shaping, and post-conditioning de-cresting. Although each process can be configured to operate independently within a waveshaping circuit, the operating parameters for each process are preferably selected to complement each other so that the waveshaping circuit as a whole functions optimally. In one embodiment, the operating parameters are selected a priori and remain static. In another embodiment, a global de-cresting control selects operating parameters adaptively and can adjust the operating parameters dynamically. [0067] FIG. 4 illustrates a waveshaping circuit 400 according to an embodiment of the present invention that adaptively modifies the waveshaping processing to fit predetermined criteria. It will be understood by one of ordinary skill in the art that the number of individual input symbol streams processed by the waveshaping circuit 400 can vary over a broad range. The waveshaping circuit 400 shown in FIG. 4 is configured to process three such input symbol streams, which are a first input symbol stream 402 , a second input symbol stream 404 , and a third input symbol stream 406 . As an output, the waveshaping circuit 400 generates an output sample stream 408 . [0068] The output sample stream 408 is advantageously monitored by a de-cresting control 416 , which calculates and provides updates for the waveshaping circuit 400 to allow the waveshaping circuit to adapt the waveshaping processing to the input symbol stream. The de-cresting control 416 also monitors the first input symbol stream 402 , the second input symbol stream 404 , and the third input symbol stream 406 . In addition, the de-cresting control 416 receives a reference information 418 . [0069] In response to the monitored input symbol streams 402 , 404 , 406 , the monitored output sample stream 408 , and the reference information 418 , the de-cresting control 416 generates and provides parameter updates to the first preconditioning circuit 410 , to the second preconditioning circuit 412 , to the third preconditioning circuit 414 , and to the post-conditioning pulse generator 428 . The parameter updates can include updates to coefficients used in digital filters, such as a finite impulse response (FIR) filter. [0070] The first preconditioning circuit 410 , the second preconditioning circuit 412 , the third preconditioning circuit 414 , and the post-conditioning pulse generator 428 shown in FIG. 4 are similar to the first preconditioning circuit 310 , the second preconditioning circuit 312 , the third preconditioning circuit 314 , and the post-conditioning pulse generator 348 described earlier in connection with FIG. 3 . Further details of a preconditioning circuit are described later in connection with FIGS. 5, 7 , and 8 . [0071] In one embodiment, the reference information 418 controls an amount of dynamic range compression by the waveshaping circuit 400 . The reference information 418 can also be used to control a relative “hardness” or relative “softness” of limiting as described later in connection with FIG. 7 . The de-cresting control 416 permits the overall performance of the waveshaping circuit 400 to be monitored and permits adjustments to be made to the parameters of individual, multiple or all of the sub-components of the waveshaping circuit 400 . For example, the de-cresting control 416 can be used to adapt the processing of a waveshaping circuit to RF transmitters with a broad range of output power. [0072] The de-cresting control 416 does not have to provide parameter updates in real time. In one embodiment, the de-cresting control 416 is implemented by firmware in a general purpose DSP or by a general-purpose microprocessor or microcontroller. In one embodiment, the general purpose DSP or the general purpose microprocessor resides in an external circuit and interfaces to the first preconditioning circuit 410 , to the second preconditioning circuit 412 , to the third preconditioning circuit 414 , and to the post-conditioning pulse generator 428 . In another embodiment, the de-cresting control 416 , together with other components of the waveshaping circuit 400 , is implemented with an application specific integrated circuit (ASIC) or with a field programmable gate array (FPGA). [0073] FIG. 5 illustrates a preconditioning circuit 500 according to an embodiment of the present invention. The preconditioning circuit 500 exploits the white spectral properties of an input symbol stream 502 . The input symbol stream 502 includes a sequence of modulation symbol impulses or rectangular pulses and occupies a relatively wide frequency spectrum prior to pulse shaping by a pulse-shaping circuit. The subsequent pulse-shaping circuit filters a modified symbol stream 504 and provides the overall spectral shaping to apply the specified bandwidth constraints. [0074] One embodiment of the preconditioning circuit 500 advantageously exploits the pulse shaping by the pulse-shaping circuit to modify the overall signal characteristics of the input symbol stream 502 by application of both linear and non-linear signal processing techniques. The spectral expansion induced by non-linear signal processing is later removed by the pulse-shaping circuit. In one embodiment, a subsequent post-conditioning circuit, such as a post-conditioning pulse generator, is not permitted to process in a manner that would expand the spectrum occupied by the processed signal. One embodiment of the post-conditioning circuit accordingly processes the applied signal with linear signal processing. However, exceptions are conceivable. [0075] One embodiment of the preconditioning circuit 500 uses a pseudo random sequence of pulses that is weighted to destructively interfere with selected pulses of the input symbol stream 502 and to select an amount of destructive interference. [0076] With reference to FIG. 5 , the illustrated preconditioning circuit 500 includes a comparator 506 , a first delay circuit 508 , a weight generator 512 , a pseudo random sequence generator 514 , a second delay circuit 516 , a multiplier 518 , and a summing circuit 520 . Further operational details of the preconditioning circuit 500 are also described later in connection with FIGS. 6 A-E. [0077] The input symbol stream 502 is applied as an input to the comparator 506 and to the first delay circuit 508 . The comparator 506 detects the level of the instantaneous magnitude of the input symbol stream 502 and compares the level to a reference level information 510 to determine whether to apply signal preconditioning to the input symbol stream. The reference level information 510 can be used to indicate a threshold or a limit to the magnitude and/or phase of a signal peak. In one embodiment, the reference level information 510 is statically predetermined a priori and hard coded into the preconditioning circuit 500 . In another embodiment, the reference level information 510 is adaptively provided by the de-cresting control, which can be an internal function or circuit of the waveshaping circuit or provided by a function or circuit external to the waveshaping circuit. When the comparison indicates that signal preconditioning is to be applied, the comparator 506 applies a correction vector as an input to the weight generator 512 . [0078] The weight generator 512 receives the correction vector from the comparator 506 and a pseudo random sequence from the pseudo random sequence generator 514 . In response to the correction vector and the pseudo random sequence, the weight generator 512 computes a weight factor, which is applied as an input to the multiplier 518 . The weight factor, when applied to the pseudo random sequence, generates the appropriate correction vector that is linearly added to a delayed version of the input symbol stream 502 to destructively interfere with relatively high-amplitude signal peaks in the input symbol stream 502 . In one embodiment, the weight factor is a scalar quantity that depends on a complex value of the input symbol stream 502 and a complex value of the pseudo random sequence. [0079] The second delay circuit 516 delays the pseudo random sequence from the pseudo random sequence generator 514 to align the pseudo random sequence with the weight factor from the weight generator. The weight factor and the delayed pseudo random sequence are multiplied together by the multiplier 518 to generate the correction impulses. [0080] The input symbol stream 502 is delayed by the first delay circuit 508 . The first delay circuit 508 is configured to delay the input symbol stream 502 such that the input symbol stream 502 aligns with the correction impulses. In one embodiment, the first delay circuit 508 delays the input symbol stream 502 by an amount of time approximately equal to the latency of the comparator 506 , the weight generator 512 , and the multiplier 518 . The delays provide the preconditioning circuit 500 with time to determine whether a modifying impulse or pulse is to be introduced into the data flow in order to reduce a relatively high signal peak or crest in the data sequence and to determine an amount of a reduction in the magnitude and/or phase of the crest. [0081] The delayed input symbol stream from the first delay circuit 508 is linearly summed by the summing circuit 520 with the correction impulses from the multiplier 518 . The linear superposition of the summing circuit 520 generates the modified symbol stream 504 as an output. The relatively high signal peaks in the input symbol stream 502 are reduced in the modified symbol stream 504 by destructive interference of the input symbol stream 502 with the correction impulses. [0082] Advantageously, the illustrated preconditioning circuit 500 can produce both phase variations and amplitude variations in the input symbol stream 502 to de-crest the input symbol stream 502 . The ability to provide a phase variation finds particular utility in multi-carrier applications, as will be described in connection with FIGS. 3, 4 , 9 , and 10 . [0083] FIGS. 6 A-E illustrate an example of the operation of the preconditioning circuit 500 illustrated in FIG. 5 . For clarity, the example shown in FIGS. 6 A-E is drawn with the input symbol stream 502 and the pseudo random sequence represented as scalar quantities. It will be understood by one of ordinary skill in the art that both the input symbol stream 502 and the pseudo random sequence are generally complex quantities with both magnitude and phase. Also for clarity, the example shown in FIGS. 6 A-E does not show the delay in the first delay circuit 508 and in the second delay circuit 516 . [0084] In FIGS. 6 A-E, a plurality of horizontal axes 602 , 604 , 606 , 608 , 610 indicate time. FIG. 6A illustrates an example of the input symbol stream 502 , which is applied as an input to the preconditioning circuit 500 . Dashed lines 612 , 614 indicate a predetermined threshold level. For example, the predetermined threshold level can correspond to a peak output power level of an associated RF transmitter. In the example, four events 616 , 618 , 620 , 622 exceed the predetermined threshold level. [0085] FIG. 6B illustrates a time aligned pseudo random sequence of constant amplitude signal pulses from the pseudo random sequence generator 514 . FIG. 6C illustrates a sequence of weight factors that are calculated by the weight generator 512 . The weight factors are applied to the pseudo random sequence to generate the correction impulses. FIG. 6D illustrates a sequence of the correction impulses for the preconditioning circuit 500 . [0086] FIG. 6E illustrates the modified symbol stream 504 . The modified symbol stream 504 is the time-aligned linear superposition of the input symbol stream 502 with the correction impulses. The correction impulses destructively interfere with the four events 616 , 618 , 620 , 622 shown in FIG. 6A so that an output level of the modified symbol stream 504 shown in FIG. 6E remains at or below the predetermined threshold level as shown by the dashed lines 612 , 614 . In one embodiment, the preconditioning circuit 500 applies correction impulses to the input symbol stream 502 such that the modified symbol stream 504 does not transgress beyond a selected signal level threshold. [0087] FIG. 7 graphically represents limiting with a relatively soft signal level threshold and limiting with a relatively hard signal level threshold. A horizontal axis 702 indicates an input level. A vertical axis 704 indicates an output level. [0088] A first trace 706 corresponds to limiting with a relatively hard signal level threshold. In practice, the use of a single hard signal level threshold is not appropriate because the resulting complementary cumulative distribution function (CCDF) of the signal, as described earlier in connection with FIG. 2 , will not exhibit a smooth transition but rather an abrupt or rapid “cliff.” Such an approach often results in an unacceptably high error rate in the downstream receiver. [0089] The preconditioning circuits according to the present invention advantageously overcome the disadvantages of relatively hard signal level thresholding by employing a nonlinear weighting function that provides a varying amount of correction depending upon the magnitude of the input data stream. A second trace 708 , a third trace 710 , and a fourth trace 712 represent exemplary transfer functions associated with a relatively soft signal-leveling threshold. [0090] This approach of soft weighting eliminates the rapid onset of a “cliff” in the CCDF and replaces the abrupt cliff with a relatively soft region in which the probability of a signal level exceeding a predetermined signal level is significantly less than that exhibited by the intrinsic input symbol stream. At relatively high signal levels, the non-linear weighting function approaches a hard threshold, and a delay “cliff” in the signal's CCDF occurs. The soft weighting approach does, however, provide a significant decrease in the level of error energy observed by the downstream receivers. [0091] The preconditioning circuit 500 operates by deliberately manipulating the amplitude and phase probability density function of the input signal waveform so that the peak to average of the input signal's impulse stream is significantly lower than the original input waveform. In practice, any function or non-linear equation that exhibits behavior which incurs desirable changes in the weight calculation can be employed by the preconditioning circuit 500 . In one embodiment, the non-linear weighting function is expressed by Equation 1. In addition, the deliberate insertion of Amplitude Modulation (AM), Phase Modulation (PM), or both can require an alternative function. [0092] Equation 1 defines a family of soft preconditioning weighting functions. Equation 1 includes parameters α and β, which correspond to the degree of non-linearity invoked. V m ⁡ ( t ) =  V m ⁡ ( t )  ( 1 + (  V m ⁡ ( t )  β ) α ) 1 / α ⁢ ⅇ j ⁡ ( arg ⁡ ( V m ⁡ ( t ) ) ) Eq .   ⁢ 1 [0093] As α increases, the gain of the function increases, which permits an overall level of preconditioning to be defined. Manipulation of β permits the rate at which a hard clipping level is set. [0094] FIG. 8 illustrates another preconditioning circuit 800 according to an embodiment of the present invention. The illustrated preconditioning circuit 800 uses multipliers and coefficients to calculate a Taylor series expansion of the non-linear weighting function shown in Equation 1. [0095] The approximation of the non-linear weighting function by the Taylor series expansion includes at least three engineering compromises: delay latency, power consumption, and precision of the Taylor series approximation. The delay latency of the preconditioning circuit 800 increases as a function of the order of the Taylor series expansion, i.e., increases with the number of multiplier stages. The power consumption of the preconditioning circuit 800 increases as the number of multipliers is increased. The weighting function is less closely approximated by the Taylor series expansion, where fewer terms of the Taylor series expansion are computed. [0096] The Taylor series approximation approach uses relatively extensive delay balancing between each of the signal processing paths to ensure that the calculated preconditioning function, represented in FIG. 8 as “p,” applies to the appropriate input samples. The illustrated preconditioning circuit 800 computes the Taylor series expansion to the fourth order. It will be understood by one of ordinary skill in the art that the preconditioning circuit 800 can be implemented in software as well as in hardware. [0097] The illustrated preconditioning circuit 800 includes a magnitude computation circuit 802 , a first delay circuit 804 , a first multiplier 806 , a second multiplier 808 , a third multiplier 810 , a second delay circuit 812 , a third delay circuit 814 , a fourth delay circuit 816 , a fifth delay circuit 818 , a sixth delay circuit 820 , a coefficient bank 822 , a fourth multiplier 824 , a fifth multiplier 826 , a sixth multiplier 828 , a seventh multiplier 830 , a summing circuit 832 , an eighth multiplier 834 , and a ninth multiplier 836 . [0098] Generally, the input symbol stream is complex, with both an in-phase component and a quadrature-phase component. The in-phase component of the input symbol stream, I input , is applied as an input to the magnitude computation circuit 802 and to the first delay circuit 804 . The quadrature phase component of the input symbol stream, Q input , is applied as an input to the magnitude computation circuit 802 and to the first delay circuit 804 . The magnitude computation circuit 802 computes the magnitude of the input symbol stream. In one embodiment, the computed magnitude corresponds approximately to a sum of squares. [0099] An output of the magnitude computation circuit 802 , termed “magnitude,” is applied as an input to the first multiplier 806 , the second delay circuit 812 , and the fourth delay circuit 816 . The first multiplier 806 multiplies the magnitude by itself to produce a square of the magnitude as an output. The output of the first multiplier 806 is applied as an input to the second multiplier 808 and to the fifth delay circuit 818 . [0100] The second multiplier 808 receives and multiplies the output of the first multiplier 806 and an output of the second delay circuit 812 . The second delay circuit 812 delays the magnitude or the output of the magnitude computation circuit 802 by a latency associated with the first multiplier 806 . The second multiplier 808 multiplies the squared magnitude from the first multiplier 806 with the first delayed magnitude from the second delay circuit 812 to generate a cubed magnitude. [0101] The cubed magnitude output of the second multiplier is applied as an input to the third multiplier 810 and to the sixth delay circuit 820 . The first delayed magnitude output of the second delay circuit 812 is applied as an input to the third delay circuit 814 , which generates a second delayed magnitude. The second delayed magnitude from the third delay circuit 814 and the cubed magnitude from the second multiplier 808 are provided as inputs to the third multiplier 810 . The third multiplier 810 generates an output, which corresponds to the magnitude raised to the fourth power. [0102] The output of the third multiplier 810 is provided as an input to the seventh multiplier 830 . The output of the third multiplier 810 is delayed from the magnitude output of the magnitude computation circuit 802 by the sum of the latency time of the first multiplier 806 , the latency time of the second multiplier 808 , and latency time of the third multiplier 810 . The sixth delay circuit 820 , the fifth delay circuit 818 , and the fourth delay circuit 816 delay samples such that Taylor series expansion terms combined by the summing circuit 832 correspond to the same sample. [0103] The sixth delay circuit 820 delays the magnitude cubed output of the second multiplier 808 by the latency time of the third multiplier 810 to time align the magnitude cubed output with the magnitude to the fourth power of the third multiplier 810 . [0104] The fifth delay circuit 818 delays the magnitude squared output of the first multiplier 806 by the sum of the latency time of the second multiplier 808 and the latency time of the third multiplier 810 . The fifth delay circuit 818 time aligns the magnitude squared output of the first multiplier 806 with the magnitude to the fourth power output of the third multiplier 810 . [0105] The fourth delay circuit 816 delays the magnitude output of the magnitude computation circuit 802 approximately by the sum of the latency time of the first multiplier 806 , the latency time of the second multiplier 808 , and the latency time of the third multiplier 810 . It will be understood by one of ordinary skill in the art that the fourth delay circuit 816 , the fifth delay circuit 818 , and the sixth delay circuit 820 can be placed in the signal path either before or after the fourth multiplier 824 , the fifth multiplier 826 , and the sixth multiplier 828 , respectively. [0106] The fourth multiplier 824 , the fifth multiplier 826 , the sixth multiplier 828 , and the seventh multiplier 830 compute the individual terms of the Taylor series expansion. The coefficient bank 822 stores the coefficients of the Taylor series expansion. The coefficients are applied as inputs to the fourth multiplier 824 , to the fifth multiplier 826 , to the sixth multiplier 828 , and to the seventh multiplier 830 . The outputs of the fourth delay circuit 816 , the fifth delay circuit 818 , the sixth delay circuit 820 and the third multiplier 810 are also applied as inputs to the fourth multiplier 824 , the fifth multiplier 826 , the sixth multiplier 828 , and the seventh multiplier 830 , respectively. In one embodiment, the latency times of the fourth multiplier 824 , the fifth multiplier 826 , the sixth multiplier 828 , and the seventh multiplier 830 are approximately equal. [0107] The outputs of the fourth multiplier 824 , the fifth multiplier 826 , the sixth multiplier 828 , and the seventh multiplier 830 are provided as inputs to the summing circuit 832 to compute the Taylor series expansion of the preconditioning function. The output of the summing circuit 832 is provided as an input to the eighth multiplier 834 and to the ninth multiplier 836 . The outputs of the first delay circuit 804 are also provided as inputs to the eighth multiplier 834 and to the ninth multiplier 836 . [0108] The first delay circuit 804 delays the in-phase component of the input symbol stream and the quadrature-phase component of the input symbol stream to time align the in-phase component and the quadrature-phase component with the corresponding preconditioning function as provided by computation of the Taylor series expansion. In one embodiment, the delay of the first delay circuit 804 is approximately the sum of the latency time of the magnitude computation circuit 802 , the latency time of the first multiplier 806 , the latency time of the second multiplier 808 , the latency time of the third multiplier 810 , the latency time of the seventh multiplier 830 , and the latency time of the summing circuit 832 . [0109] The preconditioning circuit 800 illustrated in FIG. 8 can be implemented in hardware or by software. For example, where the data rate is relatively low, the preconditioning circuit 800 can be implemented by software running on a general-purpose digital signal processor (DSP) or a microprocessor. In a relatively wideband application, the preconditioning circuit 800 can be fabricated in dedicated hardware with, for example, a field programmable gate array (FPGA) or with an application specific integrated circuit (ASIC). [0110] FIG. 9 illustrates another waveshaping circuit 900 according to one embodiment of the present invention. The waveshaping circuit 900 receives multiple input symbol streams and advantageously detects when the multiple input symbol streams fortuitously destructively interfere with each other such that an amount of preconditioning applied to the individual input symbol streams can be decreased or eliminated. [0111] In the multi-carrier waveshaping circuit 300 and the waveshaping circuit 400 described earlier in connection with FIGS. 3 and 4 , respectively, an individual preconditioning circuit independently applies preconditioning to limit a relatively high signal peak in its respective input symbol stream. However, where multiple input symbol streams are eventually combined, such as by the first summing circuit 350 described in connection with FIGS. 3 and 4 , the multiple input symbol streams may on occasion destructively interfere with each other. On these occasions, the preconditioning applied to relatively high signal peaks in the input symbol streams can be decreased or eliminated, thereby reducing or eliminating the associated injection of error energy that otherwise would have been injected into the composite multicarrier waveform stream by the preconditioning circuits and the post-conditioning circuit. [0112] For illustrative purposes, the waveshaping circuit 900 shown in FIG. 9 processes three input symbol streams. However, it will be understood by one of ordinary skill in the art that the number of input symbol streams processed by embodiments of the present invention is arbitrary. A broad range of input symbol streams can be processed by embodiments of the present invention. [0113] The illustrated waveshaping circuit 900 includes the first pulse-shaping filter 316 , the second pulse-shaping filter 318 , the third pulse-shaping filter 320 , the first mixer 322 , the second mixer 324 , the third mixer 326 , the first digital NCO 328 , the second digital NCO 330 , the third digital NCO 332 , and the first summing circuit 350 described earlier in connection with FIG. 3 . The waveshaping circuit 900 further includes a first preconditioning circuit 910 , a second preconditioning circuit 912 , a third preconditioning circuit 914 , a crest predictive weight generator 916 , a post-conditioning pulse generator 928 , a second summing circuit 930 , and a delay circuit 932 . [0114] A first input symbol stream 902 , a second input symbol stream 904 , and a third input symbol stream 906 are applied as inputs to the first preconditioning circuit 910 , the second preconditioning circuit 912 , the third preconditioning circuit 914 , respectively, and to the crest predictive weight generator 916 . The first preconditioning circuit 910 , the second preconditioning circuit 912 , the third preconditioning circuit 914 , respectively, and to the crest predictive weight generator 916 can be similar to the preconditioning circuits described in connection with FIGS. 5 and 8 . [0115] A digital NCO phase information 934 , a second digital NCO phase information 936 , and a third digital phase information 938 from the first digital NCO 328 , the second digital NCO 330 , and the third digital NCO 332 , respectively, are applied as inputs to the crest predictive weight generator 916 . The phase information allows the crest predictive weight generator 916 to determine how the input symbol streams will combine. The crest predictive weight generator 916 can use pulse-shaping filters to predict how the input symbol streams will combine. In one embodiment, the length, the latency, or both the latency and the length of the pulse-shaping filters of the crest predictive weight generator 916 is less than the length, the latency, or both the latency and the length of the pulse-shaping filters 316 , 318 , 320 . [0116] The crest predictive weight generator 916 examines the multiple information symbol streams and the corresponding phases of the digital numerical controlled oscillators to determine or to predict whether a relatively high-level signal crest will subsequently occur in the combined signal. When the crest predictive weight generator 916 predicts that a relatively high-amplitude signal crest will occur in the combined signal, the crest predictive weight generator 916 provides weight values to the pre-conditioning circuits that allow the preconditioning circuits to individually process their respective input symbol streams to reduce the relatively high amplitude signal peaks. When the crest predictive weight generator 916 predicts that destructive interference between the symbol streams themselves will reduce or will eliminate the relatively high-level signal crest, the crest predictive weight generator 916 provides weight values to the preconditioning circuits that reduce or disable the preconditioning applied by the preconditioning circuits. [0117] The crest predictive weight generator 916 can optionally provide an advanced crest occurrence information 940 to the post-conditioning pulse generator 928 . The advanced crest occurrence information 940 can advantageously be used to reduce computation latency in the waveshaping circuit 900 by allowing the post-conditioning pulse generator 928 to initiate early production of band-limited pulses, such as Gaussian pulses, which are applied to destructively interfere with a composite signal output of the delay circuit 932 . In other aspects, one embodiment of the post-conditioning pulse generator 928 is similar to the post-conditioning pulse generator 348 described earlier in connection with FIG. 3 . [0118] One embodiment of the crest predictive weight generator 916 provides the weight value as a binary value with a first state and a second state. For example, in the first state, the crest predictive weight generator 916 allows waveshaping, and in the second state, the crest predictive weight generator 916 disables waveshaping. The crest predictive weight generator 916 provides the weight value or values to the preconditioning circuits and the crest occurrence information to the post-conditioning circuit in real time and not in non-real time. By contrast, the de-cresting control 416 described in connection with FIG. 4 can provide parameter updates to preconditioning and to post-conditioning circuits in either real time or in non-real time. In one embodiment, a waveshaping circuit includes both the crest predictive weight generator 916 and the de-cresting control 416 . [0119] The advanced crest occurrence information 940 allows the crest predictive weight generator 916 to notify the post-conditioning pulse generator 928 of when the input symbol streams at least partially destructively interfere when combined. This allows the post-conditioning pulse generator to correspondingly decrease the magnitude of the band-limited pulse or to eliminate the band-limited pulse that would otherwise be applied by the post-conditioning pulse generator 928 to the composite signal to reduce relatively high-amplitude signal peaks. [0120] In one embodiment, the first preconditioning circuit 910 , the second preconditioning circuit 912 , and the third preconditioning circuit 914 are adapted to receive weight values 920 , 922 , 924 from the crest predictive weight generator 916 and are also adapted to modify the preconditioning according to the received weight values. In one embodiment, the weight values 920 , 922 , 924 are the same for each preconditioning circuit and can be provided on a single signal line. In another embodiment, the weight values 920 , 922 , 924 are individually tailored for each preconditioning circuit. [0121] The preconditioning circuit 500 described in connection with FIG. 5 can be modified to be used for the first preconditioning circuit 910 , the second preconditioning circuit 912 , or the third preconditioning circuit 914 by allowing the applied weight value provided by the crest predictive weight generator 916 to vary the weight applied by the weight generator 512 . In another embodiment, the weight value from the crest predictive weight generator 916 disables the summation of the input symbol stream 502 with the correction impulse by, for example, partially disabling the summing circuit 520 , disabling the multiplier 518 , or by otherwise effectively zeroing the correction impulse. [0122] The preconditioning circuit 800 described in connection with FIG. 8 can also be modified to be used for the first preconditioning circuit 910 , the second preconditioning circuit 912 , and the third preconditioning circuit 914 . For example, when the amount of preconditioning is decreased, the weight values applied to the preconditioning circuit 800 can be used to select alternative coefficients in the coefficient bank 822 . The weight values can also be used to decrease a magnitude of the applied preconditioning by, for example, attenuating the output of the summing circuit 832 . Where the preconditioning is disabled, the weight value can be used to disable a portion of the preconditioning circuit 800 , such as the summing circuit 832 or the eighth multiplier 834 and the ninth multiplier 836 , to disable the preconditioning. [0123] The waveshaping circuit 900 can further include an additional delay circuit to compensate for computational latency in the crest predictive weight generator 916 . In one embodiment, the first preconditioning circuit 910 , the second preconditioning circuit 912 , and the third preconditioning circuit 914 include the additional delay circuit. [0124] In addition to detecting when the input symbol streams destructively interfere with each other so that an amount of waveshaping can be reduced or eliminated, one embodiment of the crest predictive weight generator 916 advantageously detects when a relatively short transitory sequence of impulses or pulses from the information source sequentially exhibits similar amplitude and phase levels and would otherwise give rise to a relatively large crest. [0125] Pulse-shaping filters, such as the first pulse-shaping filter 316 , the second pulse-shaping filter 318 , and the third pulse-shaping filter 320 , limit the spectral occupancy of impulse and pulse information-bearing data streams in communication systems. A deleterious characteristic of these filters is that the peak to average of the pulse or impulse stream is invariably expanded during the pulse-shaping process, often by in excess of 3 dB. These newly introduced signal crests are generally attributed to Gibbs filter ringing effects. Ordinarily, relatively large crests occur when a relatively short transitory sequences of impulses or pulses from the information sources sequentially exhibit similar amplitude and phase levels. These scenarios may be advantageously predicted by the crest predictive weight generator 916 . [0126] Upon detection of the relatively short transitory sequence of impulses or pulses that sequentially exhibit similar amplitude and phase levels, the crest predictive weight generator 916 selects compensation with a sequence of corrective vectors rather than compensation with a single corrective vector. This distributes the introduction of error energy over a short sequence of modulation symbols rather than to a single symbol. In systems that do not exploit code division multiple access (CDMA), such as Enhanced Data GSM Environment (EDGE), the distribution of the error energy is desirable because it mitigates against the impact of error energy upon the downstream receiver's detector error rate. [0127] FIG. 10 illustrates further details of a multicarrier de-cresting circuit 1000 according to an embodiment of the present invention. The illustrated multicarrier de-cresting circuit 1000 does not include pre-conditioning of the input symbol streams. [0128] The multicarrier de-cresting circuit 1000 shown in FIG. 10 includes a multiple channel circuit 1002 , a de-cresting pulse generation circuit 1004 , and a de-cresting combiner 1006 . The multiple channel circuit 1002 pulse-shapes, upconverts, and combines multiple input symbol streams. In one embodiment of the multicarrier de-cresting circuit 1000 , the multiple channel circuit 1002 corresponds to a conventional circuit. Another embodiment of the multicarrier de-cresting circuit 1000 uses a multiple channel circuit described in greater detail later in connection with FIG. 16 . [0129] The de-cresting pulse generation circuit 1004 generates carrier waveforms and generates post-compensation band-limited de-cresting pulses. A pulse generator control 1008 receives and inspects a composite multicarrier signal M c (t) 1010 , individual subcarrier signals (or baseband equivalents), and digital NCO waveforms. This permits the pulse generator control 1008 to determine the requirement for, the total number of, the duration, the frequency, the amplitude and the phase of band-limited pulses that are to be injected into the transmission data stream to reduce or to eliminate relatively high amplitude peaks in the composite multicarrier signal 1010 . In one embodiment, the band-limited pulses are Gaussian pulses that are provided by a bank of generalized Gaussian pulse generators that accept commands from the pulse generator control 1008 to generate a pulse of a specific duration, phase, amplitude and center frequency. Further details of the de-cresting pulse generation circuit 1004 are described later in connection with FIG. 15 . Further details of the pulse generator control 1008 are described later in connection with FIGS. 13 A-E. [0130] The de-cresting combiner 1006 combines the upconverted input symbol streams with the post-compensation band-limited de-cresting pulses to remove the relatively high-level signal crests from the combined input symbol streams. The de-cresting combiner 1006 includes a time delay circuit 1012 . The time delay circuit 1012 delays the composite multicarrier signal 1010 to a time-delayed composite multicarrier signal 1016 . The delay of the time delay circuit 1012 is matched to the corresponding delay in the de-cresting pulse generation circuit 1004 so that a desired amount of destructive interference can be reliably induced. An output of the time delay circuit 1012 is provided as an input to a multi-input summing junction 1014 , which provides a de-crested composite multicarrier signal 1018 as the linear sum of the composite multicarrier signal 1010 , as delayed by the time delay circuit 1012 , and a collection of band-limited pulses. It will be understood by one of ordinary skill in the art that the band-limited pulses can be individually applied to the multi-input summing junction 1014 or the band-limited pulses can be combined to a composite pulse stream and then applied to the multi-input summing junction 1014 . [0131] In one embodiment, the band-limited pulses are Gaussian pulses. The collection of Gaussian pulses can include zero, one, or multiple pulses depending on the instantaneous magnitude of the composite multicarrier signal 1010 . [0132] FIGS. 11 A-E illustrate an example of the operation of the multicarrier de-cresting circuit 1000 shown in FIG. 10 . With reference to FIGS. 11 A-E, horizontal axes 1102 , 1104 , 1106 , 1108 , 1110 indicate time. As shown in FIGS. 11 A-E, time increases to the right. FIG. 11A includes a first waveform 1112 , which corresponds to an illustrative portion of the composite multicarrier signal 1010 . The first waveform 1112 further includes a waveform crest 1114 , which corresponds to a relatively high-amplitude signal crest in the composite multicarrier signal 1010 . Although the average power level of the composite multicarrier, signal 1010 can be relatively low, the waveform crest 1114 illustrates that the information sources, which contribute to the input symbol streams, can occasionally align and generate a relatively high-amplitude signal peak. For example, a signal peak that is about 10 dB above the average power level can occur with a probability of 10 −4 . In another example, 14 dB signal peaks can occur with a probability of 10 −6 . [0133] FIG. 11B illustrates a second waveform 1116 with a pulse 1118 . The pulse 1118 of the second waveform 1116 corresponds to a band-limited pulse, such as a Gaussian pulse, which is generated by the de-cresting pulse generation circuit 1004 to destructively interfere with the relatively high-amplitude signal crest in the composite multicarrier signal 1010 as illustrated by the waveform crest 1114 . [0134] FIG. 11C illustrates a third waveform 1120 , which corresponds to the time-delayed composite multicarrier signal 1016 . The time delay circuit 1012 delays the composite multicarrier signal 1010 to the time-delayed composite multicarrier signal 1016 to compensate for the computational latency of the de-cresting pulse generation circuit 1004 . This alignment is shown in FIGS. 11B and 11C by the alignment of the delayed signal crest 1122 with the pulse 1118 . [0135] The band-limited pulse destructively interferes with the relatively high signal peak in the time-delayed composite multicarrier signal 1016 . FIG. 11D illustrates a fourth waveform 1124 , which corresponds to the output of the multi-input summing junction 1014 . The fourth waveform 1124 is thus the linear superposition of the second waveform 1116 and the third waveform 1120 . In the fourth waveform 1124 , a compensated portion 1126 is substantially devoid of the waveform crest 1114 by the destructive interference induced by the band-limited pulse. FIG. 11E superimposes the second waveform 1116 , the third waveform 1120 , and the fourth waveform 1124 . [0136] FIGS. 12 A-C illustrate a complementary frequency domain analysis of the multicarrier de-cresting circuit that uses only a single Gaussian pulse to de-crest a composite waveform. FIG. 12A illustrates an example of a basic power spectral density plot (PSD) of a composite single carrier signal 1202 and a PSD plot of a single Gaussian pulse 1204 . FIG. 12A also illustrates a resulting output signal power spectral density 1206 when the composite single carrier signal 1202 and the single Gaussian pulse 1204 are linearly combined. In one embodiment, the multicarrier de-cresting circuit 1000 expands the PSD only when the Gaussian pulse's characteristics expand the signal energy beyond the basic frequency allocation. Thus, the bandwidth expansion of the combined signal is readily controlled by controlling the characteristics of the de-cresting pulse generation circuit 1004 configured to generate a single Gaussian pulse. [0137] FIG. 12B also illustrates the applicability of a generating a single Gaussian pulse to reduce a magnitude of a signal crest in a multicarrier application. A trace 1208 corresponds to a basic PSD plot corresponding to a multicarrier signal crest. A trace 1210 corresponds to a PSD plot of the single Gaussian pulse. A trace 1212 illustrates a composite PSD of the combination of the multicarrier signal crest with the single Gaussian pulse. [0138] FIG. 12C illustrates a disadvantage of generating a single Gaussian pulse to reduce the magnitude of a signal crest in a multicarrier signal. In the example shown in FIG. 12C , one of the channel streams is dropped either temporarily or permanently from the composite multicarrier signal 1010 . A trace 1214 corresponds to a basic PSD of the multicarrier signal crest with a channel stream dropped. A trace 1216 corresponds to a PSD plot of the single Gaussian pulse. A trace 1218 illustrates a composite PSD of the combination of the single Gaussian pulse and the multicarrier signal crest with the channel stream dropped. As shown in FIG. 12C , energy from the Gaussian pulse increases the residual energy level within the unoccupied channel allocation. The increase in residual energy in the unoccupied channel is relatively undesirable in a commercial application. [0139] Embodiments of the invention, such as the multicarrier de-cresting circuit 1000 described in connection with FIG. 10 , advantageously overcome the undesirable polluting of unoccupied channel allocations by injecting multiple band-limited pulses from multiple pulse generators. In one embodiment, the multiple band-limited pulses are Gaussian pulses. The generation of multiple band-limited pulses allows the pulse generator control to determine the PSD content in each of the allocated channels and advantageously insert Gaussian pulse energy only into occupied channels to counteract the signal peak. This advantageously prevents the injection of Gaussian pulse energy to unoccupied channel allocation. [0140] Further, one embodiment of the pulse generator control 1008 is provided with the individual amplitude levels for each baseband channel's contribution to the overall composite signal's peak, so that the pulse generator control 1008 can weigh the amplitude of each Gaussian pulse according to the contribution to the peak in the composite multicarrier signal 1010 . [0141] FIGS. 13 A-E illustrate the operation of the pulse generator control 1008 described in connection with FIG. 10 . The pulse generator control 1008 advantageously provides multiple band-limited pulses, such as Gaussian pulses, that destructively interfere with the signal crests in the composite multicarrier signal 1010 . With reference to FIGS. 13 A-E, horizontal axes 1302 , 1304 , 1306 , 1308 , 1310 indicate time. As shown in FIGS. 13 A-E, time increases to the right. [0142] FIG. 13A includes a first waveform 1312 , which corresponds to a portion of the composite multicarrier signal 1010 . The first waveform 1312 further includes a waveform crest 1314 , which corresponds to a relatively high-amplitude signal crest in the composite multicarrier signal 1010 . The first waveform 1312 and the waveform crest 1314 are similar to the first waveform 1112 and the waveform crest 1114 described in connection with FIG. 11A . [0143] FIG. 13B illustrates a second waveform 1316 that includes cancellation pulses 1318 , 1320 that are generated from a family of band-limited pulses 1322 , 1324 , 1326 , 1328 , 1330 , such as Gaussian pulses. In contrast to a single destructive pulse, such as the pulse 1118 described earlier in connection with FIG. 11B , the cancellation pulses 1318 , 1320 in the second waveform 1316 include multiple cancellation pulses. The pulses in the family of band-limited pulses 1322 , 1324 , 1326 , 1328 , 1330 are selected to be centered at the corresponding active channel frequencies. The cancellation pulses 1318 , 1320 of the second waveform 1316 are generated by the de-cresting pulse generation circuit 1004 to destructively interfere with the relatively high-amplitude signal crest in the composite multicarrier signal 1010 as illustrated by the waveform crest 1314 . [0144] FIG. 13C illustrates a third waveform 1332 , which corresponds to the time-delayed composite multicarrier signal 1016 . The time delay circuit 1012 delays the composite multicarrier signal 1010 to the time-delayed composite multicarrier signal 1016 to compensate for the computational latency of the de-cresting pulse generation circuit 1004 . This alignment is shown in FIGS. 13B and 13C by the alignment of a delayed signal crest 1334 with the cancellation pulses 1318 , 1320 . [0145] The cancellation pulses 1318 , 1320 destructively interfere with the relatively high signal peak in the time-delayed composite multicarrier signal 1016 . FIG. 13D illustrates a fourth waveform 1336 , which corresponds to the output of the multi-input summing junction 1014 . The fourth waveform 1336 is thus the linear superposition of the second waveform 1316 and the third waveform 1332 . In the fourth waveform 1336 , a compensated portion 1338 is substantially devoid of the waveform crest 1314 by the destructive interference induced by the band-limited pulse. FIG. 13E superimposes the second waveform 1316 , the third waveform 1332 , and the fourth waveform 1336 . [0146] FIGS. 14A and 14B illustrate the results of a complementary frequency domain analysis of the multicarrier de-cresting circuit 1000 . With reference to FIG. 14A , a trace 1402 is a basic PSD plot of the composite multicarrier signal 1010 , which is provided as an input to the de-cresting pulse generation circuit 1004 . A trace 1404 is a PSD plot of the multiple Gaussian pulses, which are the outputs of the de-cresting pulse generation circuit 1004 . A trace 1406 is a PSD plot of the de-crested composite multicarrier signal 1018 of the multi-input summing junction 1014 , which combines the time-delayed composite multicarrier signal 1016 with the multiple Gaussian pulses. The trace 1406 illustrates that the PSD bandwidth expansion of the de-crested composite multicarrier signal 1018 can be relatively readily controlled by managing the PSD of the corresponding multiple Gaussian pulses from the de-cresting pulse generation circuit 1004 . [0147] With reference to FIG. 14B , a trace 1408 is a PSD plot of the composite multicarrier signal 1010 , where the composite multicarrier signal 1010 includes a non-utilized channel allocation. Advantageously, embodiments of the invention can inject multiple Gaussian pulses to destructively interfere with signal peaks at the utilized channel allocations, thereby preventing the expansion or pollution of the frequency spectrum. A trace 1410 is a PSD plot of multiple Gaussian pulses, which correspond to output of the de-cresting pulse generation circuit 1004 . In one embodiment, each of the multiple Gaussian pulses generated by the de-cresting pulse generator is substantially band-limited to its corresponding channel. A trace 1412 is a PSD plot of the de-crested composite multicarrier signal 1018 of the multi-input summing junction 1014 , which combines the time-delayed composite multicarrier signal 1016 with the multiple Gaussian pulses. In contrast to the injection of a single Gaussian pulse de-crest the composite multicarrier signal 1010 , which is illustrated in FIG. 12C , the injection of multiple Gaussian pulses corresponding only to allocated channels is advantageously relatively free from spectral pollution. [0148] FIG. 15 illustrates one embodiment of the de-cresting pulse generation circuit 1004 . The de-cresting pulse generation circuit 1004 advantageously provides multiple band-limited pulses to de-crest the composite multicarrier signal 1010 with relatively little pollution of the frequency spectrum. [0149] The illustrated de-cresting pulse generation circuit 1004 includes the pulse generator control 1008 and a pulse generator 1502 . The pulse generator control 1008 shown in FIG. 15 further includes a comparator 1504 , a weight generator 1506 , and an impulse generator 1508 . [0150] The composite multicarrier signal 1010 is provided as an input to the comparator 1504 . In addition, the comparator 1504 receives channel inputs from the pulse shaping filters and phase information from digital NCO sources. This information enables the comparator 1504 to determine whether to apply single or multiple cancellation pulses to de-crest the composite multicarrier signal 1010 or the time-delayed composite multicarrier signal 1016 . In one embodiment, the comparator 1504 compares these signals to reference information of the intrinsic waveform. The reference information can include the average, the peak, and other pertinent signal statistics to determine whether to apply cancellation pulses to de-crest the composite multicarrier signal 1010 . [0151] When the comparator 1504 has determined that a cancellation pulse or a group of cancellation pulses will be applied, the comparator 1504 calculates a duration for a cancellation pulse and instructs the impulse generator 1508 to provide a sequence of impulses to the pulse generator 1502 . [0152] The weight generator 1506 provides weight values to the pulse generator 1502 . The weight values are used by the pulse generator 1502 to vary an amount of a band-limited de-cresting pulse injected into a channel according to the weight value corresponding to the channel. [0153] In one embodiment, the weight generator 1506 calculates a relative magnitude and phase for each channel's contribution to the crest in the composite multicarrier signal 1010 and provides weight values to the pulse generator 1502 so that each channel suffers an approximately equal degradation in signal quality. The weight values generated by the weight generator 1506 can advantageously be set at a zero weight for inactive channels and a relatively high weight for relatively high-power channels. The weight values can correspond to positive values, to negative values, to zero, and to complex values. This allows the error vector magnitude (EVM) to be approximately equal for all active channels, while simultaneously eliminating or reducing signal crests. [0154] In another embodiment, a single active channel is randomly selected for introduction of a stronger correction pulse. This lowers aggregate error rates, but increases the severity of the errors. [0155] The pulse generator 1502 includes a group of multipliers 1510 , a group of filters 1512 , and a summing circuit 1514 . It will be understood by one of ordinary skill in the art that the waveshaping circuits and sub-circuits disclosed herein can be configured to process an arbitrary or “N” number of channels. In addition, although the pulse generator 1502 can include processing capability for several channels, it will be understood by one of ordinary skill in the art that some applications will not utilize all of the processing capability. [0156] The group of multipliers 1510 in the illustrated pulse generator 1502 can include “N” multipliers. A first multiplier 1516 multiplies the impulses from the pulse generator 1502 with the weight value from the weight generator 1506 that corresponds to a first channel. A second multiplier 1518 similarly multiplies the impulses from the pulse generator 1502 with the weight value from the weight generator 1506 that corresponds to a second channel. [0157] The group of filters 1512 in the illustrated pulse generator 1502 can include “N” passband filters. A first passband filter 1520 generates band-limited pulses in response to receiving impulses from the first multiplier 1516 . The band-limited pulses from the first passband filter 1520 are centered at approximately the first channel's frequency band or allocation. In one embodiment, the first passband filter 1520 is a Gaussian passband finite impulse response (FIR) filter. [0158] A second passband filter 1522 similarly generates band-limited pulses in response to receiving impulses from the second multiplier 1518 . The band-limited pulses from the second passband filter 1522 are centered at approximately the second channel's frequency band or allocation. In one embodiment, the second passband filter 1522 is a Gaussian passband FIR filter. Preferably, all passband filters in the group of filters 1512 are FIR filters so that the outputs of the passband filters are phase aligned. [0159] The summing circuit 1514 combines the outputs of the first passband filter 1520 , the second passband filter 1522 , and other passband filters, as applicable, in the group of filters 1512 . The output of the summing circuit 1514 is a composite stream of Gaussian pulses, which is then applied to the multi-input summing junction 1014 to reduce or to eliminate relatively high amplitude signal crests. In another embodiment, the individual outputs of the passband filters in the group of filters 1512 are applied directly the multi-input summing junction 1014 . [0160] FIG. 16 illustrates a multiple channel circuit 1600 according to an embodiment of the present invention. The multiple channel circuit 1600 advantageously reduces the likelihood of the occurrences of signal crests in composite waveforms, and can be used to decrease a frequency of application of waveshaping. It will be understood by one of ordinary skill in the art that the number of channels pulse shaped and combined by the multiple channel circuit 1600 can be arbitrarily large. [0161] The multiple channel circuit 1600 includes fractional delays, which stagger the input symbol streams relative to each other by fractions of a symbol period. In one embodiment, the delay offset from one symbol stream to another is determined by allocating the symbol period over the number of active symbol streams. For example, where “x” corresponds to a symbol period and there are four input symbol streams, a first symbol stream can have 0 delay, a second input symbol stream can have 0.25x delay, a third input symbol stream can have 0.50x delay, and a fourth input symbol stream can have 0.75x delay. [0162] The illustrated embodiment of the multiple channel circuit 1600 implements the fractional delay to the data streams before the pulse shaping filters. In one example, “N,” or the number of active symbol streams, corresponds to 4. In the multiple channel circuit 1600 , a first input symbol stream 1602 is applied as an input directly to a first pulse-shaping filter 1604 without fractional delay. In another embodiment, the data stream associated with the first input symbol stream 1602 includes a fractional delay. [0163] A second input symbol stream 1606 is provided as an input to a first fractional delay circuit 1608 , which delays the second input symbol stream 1606 relative to the first input symbol stream 1602 by a first fraction of a symbol period, such as 0.25 of the symbol period. A third input symbol stream 1612 is provided as an input to a second fractional delay circuit 1614 , which delays the third input symbol stream 1612 relative to the first input symbol stream 1602 by a second fraction of the symbol period, such as 0.50 of the symbol period. A fourth input symbol stream 1618 is applied to a third fractional delay circuit 1620 , which delays the fourth input symbol stream 1618 by a third fraction of a symbol period, such as 0.75 of the symbol period. [0164] The staggered symbol streams are mixed by their respective mixer circuits 1624 , 1626 , 1628 , 1630 and combined by a summing circuit 1632 . The staggering of the symbol streams reduces the probability of occurrence of signal crests in the resulting composite waveform 1634 because the staggering displaces each channel's individual signal crest from another channel's signal crest as a function of time. This decreases the probability of a mutual alignment in amplitude and phase in the composite waveform 1634 . [0165] However, it will be understood by one of ordinary skill in the art that the fractional delay can be applied elsewhere, such as embedded directly within a pulse-shaping filter, applied post pulse-shaping, and the like. In one embodiment, the amount of the fractional delay for each symbol stream is fixed in hardware. In another embodiment, the fractional delays can be selected or programmed by, for example, firmware. [0166] Some systems that are susceptible to relatively high-amplitude signal peaks or crests are incompatible with techniques that modify the amplitude of the underlying signals to reduce or to eliminate the relatively high-amplitude signal peaks in a composite multicarrier signal. One example of such a system is an EDGE system, where introduction of amplitude modulating pulses such as band-limited Gaussian pulses is undesirable and may not be permissible. [0167] FIG. 17 illustrates a phase-modulating waveshaping circuit 1700 according to an embodiment of the present invention. Advantageously, the phase-modulating waveshaping circuit 1700 reduces or eliminates relatively high-amplitude signal crests in composite multi-carrier signals without modulation of the amplitude of the underlying signals. Rather than sum a composite multicarrier signal with band-limited pulses to de-crest the composite multicarrier signal as described in connection with FIG. 10 , the phase-modulating waveshaping circuit 1700 modulates the phases of the input symbol streams to reduce or to eliminate relatively high signal crests in the resulting composite multicarrier signal. It will be understood by one of ordinary skill in the art that the phase-modulating waveshaping circuit 1700 can be configured to process an arbitrary or “N” number of channels. [0168] The phase-modulating waveshaping circuit 1700 includes a multiple channel circuit 1702 , a de-cresting combiner 1704 , digital NCOs 1706 , and a pulse phase modulation circuit 1708 . The multiple channel circuit 1702 receives the input symbol streams, pulse shapes and upconverts the input symbol streams. The pulse shaped and upconverted input streams are provided as inputs to the de-cresting combiner 1704 and to a pulse phase modulator control 1710 of the pulse phase modulation circuit 1708 . [0169] One embodiment of the pulse phase modulation circuit 1708 is substantially the same as the de-cresting pulse generation circuit 1004 described in connection with FIGS. 10 and 15 . However, rather than summing the composite multicarrier signal with the generated band-limited pulses, the band-limited pulses are used to phase modulate the upconverted symbol streams. As such, the pulse phase modulator control 1710 corresponds to the pulse generator control 1008 . The pulse phase modulator control 1710 predicts whether the current modulation streams and digital NCO phase combinations will constructively interfere with each other and result in a composite waveform crest. Where a crest is predicted, the Gaussian pulse phase modulators are engaged to relatively slowly modulate the individual channel phases to prevent or to reduce a signal crest in the composite waveform. [0170] A Gaussian pulse phase modulator, such as a first Gaussian pulse phase modulator 1712 corresponds to a Gaussian pulse generator, such as a first Gaussian pulse generator 1020 . Again, the corresponding Gaussian pulses gp 1 (t), gp 2 (t), and so forth, generated by the Gaussian pulse phase modulators of the pulse phase modulation circuit 1708 are band-limited to their corresponding input symbol stream's allocated channel. [0171] The de-cresting combiner 1704 includes multiple delay circuits 1714 , 1716 , 1718 , 1720 , which align the upconverted symbol streams from the multiple channel circuit 1702 with the Gaussian pulses from the pulse phase modulation circuit 1708 . The de-cresting combiner 1704 further includes phase modulators 1722 , 1724 , 1726 , 1728 , which phase modulate their respective upconverted input symbol streams in accordance with the respective Gaussian pulse from the pulse phase modulation circuit 1708 . A summing circuit 1730 combines the outputs of the phase modulators 1722 , 1724 , 1726 , 1728 and provides a de-crested composite multicarrier signal 1732 as an output. [0172] The skilled practitioner will recognize that care should be taken to ensure that the rate of change of phase due to this correction process does not exceed the capability of the downstream receivers to track effective channel phase variations. [0173] One embodiment of the present invention further uses a pulse generator control or a pulse phase modulator control that is already used to de-crest or to waveshape composite signals to continually monitor and to report the amplitude and phase information of each individual baseband channel. This information can be readily utilized to extract the average and peak power levels of individual channels. In addition, the presence of active or dormant channels can be readily ascertained. This information is extremely useful for external subsystems in a range of communications applications. [0174] In one embodiment, a waveshaping circuit includes a communications port, such as a serial communications port or a parallel communications port that enables this information to be transmitted to external devices. In another embodiment, the collected information is stored in a memory structure, which is accessed by multiple external devices requiring such information. The information can be ported to an amplifier linearization chip such as the PM7800 PALADIN product from PMCS. [0175] One embodiment of the waveshaping circuit is implemented in dedicated hardware such as a field programmable gate array (FPGA) or dedicated silicon in an application specific integrated circuit (ASIC). In a relatively low data rate application, a general purpose digital signal processor (DSP), such as a TMS320C60 from Texas Instruments Incorporated or a SHARC processor from Analog Devices, Inc., performs the waveshaping signal processing. [0176] A conventional microprocessor/microcontroller or general purpose DSP can interface to a waveshaping circuit to adaptively control the waveshaping process. For example, a de-cresting control can operate in non-real time, and a general purpose DSP or microprocessor such as a TMS320C54/TMS320C60/TMS320C40/ARM 7 or Motorola 68000 device can be used for control. Preferably, the DSP or microprocessor includes non-volatile ROM for both program storage and factory installed default parameters. Both ROM and Flash ROM are relatively well suited for this purpose. As with most DSP or microprocessor designs, a proportional amount of RAM is used for general-purpose program execution. In one embodiment, a relatively low speed portion of the waveshaping circuit implemented with a DSP or a microprocessor core and a relatively high speed portion of the waveshaping circuit implemented in an ASIC or an FPGA is integrated onto a single ASIC chip with an appropriate amount of RAM and ROM. Examples of licensable cores include the ARM7 from Advanced RISC Machines, Ltd., the Teak from DSP Group Inc., the Oak from DSP Group Inc., and the ARC from ARC Cores. [0177] Various embodiments of the present invention have been described above. Although this invention has been described with reference to these specific embodiments, the descriptions are intended to be illustrative of the invention and are not intended to be limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined in the appended claims.

The present invention is related to methods and apparatus that can advantageously reduce a peak to average signal level exhibited by single or by multicarrier multibearer waveforms. Embodiments of the invention further advantageously can manipulate the statistics of the waveform without expanding the spectral bandwidth of the allocated channels. Embodiments of the invention can be applied to either multiple carrier or single carrier systems to constrain an output signal within predetermined peak to average bounds. Advantageously, the techniques can be used to enhance the utilization of existing multicarrier RF transmitters, including those found in third generation cellular base stations. However, the peak to average power level managing techniques disclosed herein can apply to any band-limited communication system and any type of modulation. The techniques can apply to multiple signals and can apply to a wide variety of modulation schemes or combinations thereof.

FIELD OF THE INVENTION [0001] The present invention provides modified microorganisms for raising host immune responses as well as vaccines and vaccine compositions comprising the same. In particular, the invention provides a modified Streptococcus , which may form the basis of an improved vaccine for treating and/or preventing diseases. BACKGROUND OF THE INVENTION [0002] Several species of the genus Streptococcus are the causative agents of a number of diseases in humans and animals. In humans, the most frequently-encountered pathogenic species is S. pneumoniae (the pneumococcus), which causes sinusitis and otitis media, but also life-threatening conditions including pneumonia, sepsis, osteomyelitis, endocarditis, septic arthritis and meningitis among others. Second most frequently encountered in humans is the Group A Streptococcus (GAS), S. pyogenes , which is responsible for pharyngitis, glomerulonephritis, acute rheumatic fever, scarlet fever and on occasion, necrotising fasciitis. Other species, such as S. mutans , may constitute part of the normal human microflora, yet may pose a disease risk under the right conditions. [0003] Animal diseases caused by streptococci are no-less significant than those in humans. For example, S. suis causes respiratory disease, joint infections, skin conditions and meningitis in pigs. Furthermore, this organism is zoonotic, and may be acquired occupationally, resulting in meningitis, endocarditis and/or septicaemia. Another significant animal pathogen is S. equi , which causes strangles in horses. In the dairy industry, one of the major causes of mastitis in lactating cattle is S. uberis , while S. dysgalactiae subsp. dysgalactiae also contributes to the incidence of this disease. Likewise, S. agalactiae is also recognised as a cause of mastitis, but is also responsible for causing a range of other diseases in a diverse number of species including fish, aquatic mammals and humans. [0004] While vaccines against some of the major Streptococci pathogens exist, many are unreliable, inducing weak, short-lived and/or ineffective immune responses. As such, there is a requirement for new vaccines against streptococci which induce immunity in human and animal hosts. SUMMARY OF THE INVENTION [0005] The present invention is based on the finding that microorganisms can be modified so as to express certain factors important in generating or raising host immune responses. In particular, the invention provides modified microorganisms which, when subjected to conditions which would be expected to suppress or reduce the expression, function and/or activity of certain factors, exhibit increased (often significantly increased) expression, function and/or activity of those factors. In one embodiment, the factors may be virulence factors. [0006] The modified microorganisms provided by this invention may find application as agents for generating or raising immune responses and as vaccines or vaccine compositions to protect against a variety of diseases and/or conditions and/or to prevent or reduce host colonisation/infection by one or more pathogens. [0007] In a first aspect, the present invention provides a modified microorganism capable of expressing at least one factor under conditions in which a wild-type (or unmodified) strain of the same microorganism, exhibits inhibited expression of the at least one factor. [0008] It should be understood that while this invention may be described as “comprising” one or more features, the term “comprising” encompasses aspects and embodiments which “consist essentially of” or “consist of” the noted feature(s). [0009] As such, the invention may provided a modified bacterium capable of expressing at least one factor under conditions in which a wild-type (or un-modified) strain of the same bacterium, exhibits inhibited expression of the at least one factor. [0010] The modified bacterium may be a modified Streptococcus species wherein, under environmental conditions suppressing or inhibiting the expression of a factor or factors in a wild-type or un-modified form of the same Streptococcus species, the modified Streptococcus species express the factor or factors. It should be understood that references to “ Streptococcus species” encompass not only the specific species, S. suis and S. equi , but other species such as, for example, S. pyrogenes, S. epidermidis, S. pneumoniae, S. gordonii and/or S. mutans. [0011] The modified Streptococcus species may be a modified Streptococcus suis or a modified Streptococcus equi wherein, under environmental conditions suppressing or inhibiting the expression of a factor or factors in a wild-type or un-modified S. suis or S. equi , the modified S. suis and S. equi express the factor or factors. [0012] The term “factors” should be understood as encompassing proteinaceous compounds (for example proteins, peptides, amino acids and/or glycoproteins as well as small organic compounds, lipids, nucleic acids and/or carbohydrates produced by microorganisms. Many of these factors are expressed internally—i.e. within the cytoplasm of the microorganism; such factors may be classed as “internal” or “cytoplasmic”. The term “factors” may also encompass microbial factors which are secreted from the cell and/or targeted to the microbial cell wall as membrane-bound or transmembrane factors. The term “factors” may further comprise antigenic or immunogenic compounds which elicit or generate host immune responses. Such factors may include those collectively known as “virulence determinants/factors” and/or “pathogenicity factors”. One of skill will appreciate that microbial factors which are also virulence determinants/factors and/or pathogenicity factors, may comprise, for example, those which facilitate microbial attachment to host surfaces or cells and/or host cell invasion as well as those involved in toxin production and/or the toxins themselves. In view of the above, the term “factors” as used herein may comprise microbial cell wall, membrane and/or transmembrane structures such as proteins or compounds which mediate or facilitate host adherence or colonisation, pili and/or secreted enzymes, compounds and/or toxins. The term “factors” may further comprise compounds involved in metal ion acquisition. [0013] One of skill will appreciate that in wild-type microorganisms, for example wild-type bacteria including Streptococcus species (such as, for example, S. suis and/or S. equi ), the expression, function and/or activity of one or more factor(s) may be directly or indirectly regulated by one or more exogenous and/or endogenous elements. [0014] An endogenous element may directly or indirectly regulate the activity, expression and/or function of a microbial factor. An “endogenous” regulatory element may be a microbial element which regulates the function, expression and/or activity of one or more microbial factors. In contrast, an “exogenous” regulatory element may comprise an element which is not produced by, or is not a product of, a microorganism, but which directly or indirectly regulates the expression, function and/or activity of a factor expressed by that microorganism. [0015] One of skill will appreciate that in some cases, exogenous and/or endogenous regulatory elements of the type described herein, act as global regulatory elements. Global regulatory elements may regulate and/or control the expression, function and/or activity of a plurality of microbial factors. [0016] The exogenous regulatory element may comprise an environmental element. One of skill will appreciate that an environmental regulatory element may comprise a particular nutrient, compound, vitamin, metabolite, mineral, ion, electrolyte and/or salt. Additionally, or alternatively an environmental regulatory element may take the form of a physical condition such as, for example, a particular temperature, gas ratio, osmolairty and/or pH. [0017] One of skill will readily understand that the presence and/or absence of one or more (exogenous) environmental regulatory elements may directly modulate the expression, function and/or activity of one or more microbial factor(s). In other cases, the presence and/or absence of one or more environmental regulatory element(s) may modulate the expression, function and/or activity of one or more endogenous microbial regulatory element(s) (for example an endogenous (microbial) global regulatory element) which in turn effects the expression, function and/or activity of one or more microbial factor(s). [0018] Modified microorganisms provided by this invention may lack one or more endogenous regulatory/control elements. In one embodiment, the modified microorganisms may lack one or more environmentally-sensitive or responsive regulatory/control elements. As a consequence of these modifications, the modified microorganisms described herein are characterised by the expression/function and/or activity of one or more factors in environments (or under conditions) which would normally (i.e. in a wild-type or unmodified strain) suppress or inhibit the expression, function and/or activity of said factors. [0019] The factors expressed by the modified microorganisms described herein may comprise factors, the expression, function and/or activity of which is normally associated with, controlled/regulated by, dependent on and/or sensitive to, the presence and/or absence of metal ions such as, for example iron (Fe 2+ ) and/or manganese (Mn 2+ ). [0020] Advantageously, and where the invention relates to, for example, modified Streptococcus , such factors may comprise one or more Streptococcus antigens/immunogens (virulence factors) said antigens and/or immunogenes being capable of generating, raising and/or eliciting a host immune response. [0021] Accordingly, the invention may relate to a modified species of the Streptococcus genus, expressing at least 1 factor under conditions comprising manganese and/or iron concentrations which inhibit the expression of said factor in wild-type or unmodified strains of the same organism. [0022] The modified microorganisms provided by this invention may comprise one or more genetic modification(s) which directly and/or indirectly affect the expression, activity and/or function of one or more microbial regulatory elements (including global regulatory elements). A genetic modification which affects the expression, function and/or activity of a microbial regulatory element, may comprise one or more mutations in the sequence of a gene encoding said regulatory element. In contrast, a genetic modification which indirectly affects the expression, function and/or activity of a microbial regulatory element, may comprise one or more mutations in the sequence of a gene or genes which encode other elements or factors which themselves affect the activity, function and/or expression of the regulatory element. [0023] A genetic modification may comprise one or more alterations in a nucleic acid sequence. For example, a nucleic acid sequence may be modified by the addition, deletion, inversion and/or substitution of one or more nucleotides of a sequence. One of skill will appreciate that a genetic modification may effect the expression, function and/or activity of the nucleic acid sequence harbouring the modification and/or the expression, function and/or activity of the protein or peptide encoded thereby. [0024] Advantageously, modified microorganisms provided by this invention comprise genetic lesions resulting in the (“in-frame”) deletion of nucleic acid sequences. Furthermore, the modified microorganisms of this invention may lack exogenous nucleic acid—for example nucleic acids derived from vectors (for example plasmids and the like). As such, when compared to isogenic, wild-type parent strains, a modified microorganism (for example a modified Streptococcus ) of this invention may be identical except for the mutation or deletion of sequences encoding one or more regulatory elements. [0025] In Corynebacterium diphtheriae , a number of virulence factors (including diphtheria toxin (encoded by the tox gene)) are regulated by the metal ion-activated global regulatory element, DtxR (product of the dtxR gene). Other bacterial species including, for example other Corynebacterium and Streptococcus species, comprise global regulators which are structurally and/or functionally homologous (and/or (substantially) identical) to the dtxR/DtxR gene/protein of C. diphtheriae. [0026] Without wishing to be bound by theory, the inventors have discovered that microorganisms (for example species belonging to the Streptococcus genus) exhibiting modified expression, function and/or activity of a gene and/or protein homologous to the dtxR gene and/or DtxR protein of Corynebacterium diphtheriae , represent exemplary vaccine candidates. [0027] In view of the above, this invention may provide modified microorganisms capable of expressing at least one factor under conditions in which a wild-type (or un-modified) strain of the same microorganism, exhibits inhibited expression of the at least one factor, wherein the modified microorganism lacks (i) a functional dtxR homologue, (ii) a gene functionally equivalent to dtxR and/or (iii) a gene or protein which is “dtxR like”. For convenience, options (i), (ii) and (iii) above will, hereinafter, be collectively referred to as “dtxR homologues”. It should be understood that dtxR homologues encompassed by this invention (including genes/proteins which are dtxR-like) may exhibit variable (perhaps low) sequence homology/identity with the dtxR gene/protein of Corynebacterium diphtheriae but a high degree of functional homology/identity with dtxR—in other words, the dtxR homologues described herein are metalo-regulators which, through binding metal ions, exert an effect on gene expression. [0028] It should be understood any gene and/or protein being described as “functionally homologous” to the dtxR and/or DtxR gene/protein of C. diphtheriae , is a gene and/or protein which exhibits metalo-regulator activity characteristic of, or similar to the metalo-regulator activity of the dtxR/DtxR gene/protein of C. diphtheriae. [0029] The sequence encoding the C. diphtheriae dtxR gene is provided as SEQ ID No:1, below. [0000] SEQ ID NO: 1 1 atgaaagatt tggtcgatac cacagaaatg tatctgcgga ccatctacga gctggaagaa 61 gagggagtaa ctccccttcg cgcacgcatc gccgaacgcc tcgatcagtc aggccctaca 121 gtcagccaaa cagttgcccg catggaacgt gacgggctcg ttgtagttgc gtctgaccgt 181 agtcttcaaa tgacgcccac tgggcgcgct ttagccaccg ccgtaatgcg taaacatcgc 241 ctcgcagagc gcctccttac agacattatt ggcttagata tccacaaggt gcacgatgaa 301 gcatgccgct gggagcacgt catgagcgac gaagtagagc ggcggcttgt tgatgtcctc 361 gaggacgtca cccgctcccc ctttggcaac ccaatcccag gtctcgatga acttggcgtc 421 tccataaaaa agaaggaagg accgggcaaa cgtgccgtgg atgtagcccg tgccaccccc 481 agagacgtaa agattgttca aatcaacgag atattgcaag tagattctga ccagtttcag 541 gctctgatcg acgcaggcat tagaattgga acgaccgtca cgctcagcga tgtagacggt 601 cgcgtgatta ttacgcacgg tgaaaaaaca gtagaactta tcgacgacct agctcacgca 661 gtacgaatcg aagaaatcta a [0030] An exemplary DtxR protein sequence has been deposited as accession No: YP — 005162868. A sequence of the dtxR protein is given as SEQ ID NO: 2 below: [0000] SEQ ID NO: 2 1 mkdlvdttem ylrtiyelee egvtplrari aerleqsgpt vsqtvarmer dglvvvasdr 61 slqmtptgrt latavmrkhr laerlltdii gldinkvhde acrwehvmsd everrlvkvl 121 kdvsrspfgn pipgldelgv gnsdaaapgt rvidaatsmp rkvrivqine ifqvetdqft 181 qlldadirvg seveivdrdg hitlshngkd vellddlaht irieel [0031] Homologous and/or identical dtxR and/or DtxR genes/proteins may encompass those encoded by nucleic acid and/or amino acid sequences which exhibit at least about 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% homology or identity with SEQ ID NOS: 1 or 2 above or fragments thereof. [0032] The degree of (or percentage) “homology” between two or more (amino acid or nucleic acid) sequences may be determined by aligning the sequences and determining the number of aligned residues which are identical and adding this to the number of residues which are not identical but which differ by redundant nucleotide substitutions—the redundant nucleotide substitution having no effect upon the amino acid encoded by a particular codon, or conservative amino acid substitutions. The combined total is then divided by the total number of residues compared and the resulting figure is multiplied by 100—this yields the percentage homology between aligned sequences. [0033] A degree of (or percentage) “identity” between two or more (amino acid or nucleic acid) sequences may also be determined by aligning the sequences and ascertaining the number of exact residue matches between the aligned sequences and dividing this number by the number of total residues compared—multiplying the resultant figure by 100 would yield the percentage identity between the sequences. [0034] This invention provides a modified microorganism, wherein the modified microorganism comprises a modified dtxR/DtxR homologue. The invention may also provide modified microorganisms of the Streptococcus genus, wherein the modified microorganism of the Streptococcus genus comprises a modified dtxR/DtxR homologue. In these embodiments, the modified dtxR/DtxR homologue may exhibit a degree of homology/identity (as defined above) to the sequences disclosed as SEQ ID NOS: 1 and 2 herein. [0035] Insofar as this specification relates to modified Streptococci, examples of dtxR/DtxR homologues to be exploited (i.e. modified) for production of a modified microorganism of this invention, may include those listed in Table 1 below. [0000] TABLE 1 dtxR homologues in Streptococcus species Metal Organism Regulator ion binding Ref/Accession S. suis ScaR (aka SloR) Mn 2+ Jakubovics et al 2000 S. equi TroR S. pyrogenes MtsR Mn 2+ Jakubovics et al 2000 S. epidermidis SirR Mn 2+ CAA67572 S. pneumoniae PsaR Jakubovics et al 2000 S. gordonii ScaR AAF25184 S. mutans SloR Jakubovics et al 2000 [0036] A modified S. suis of this invention may take the form of a scaR deficient (scaR − ) strain, genetically modified to lack a functional scaR gene or product (i.e. a functional “ScaR” protein). A modified S. suis according to this embodiment of the invention may express factors (for example virulence factors) normally under the control of ScaR in a manner which is independent of the expression, function and/or activity of ScaR. [0037] The sequence of the S. suis scaR gene (a dtxR homologue) is given below as SEQ ID No.: 3. [0000] SEQ ID NO: 3:  S. suis  scaR atgacaccaaacaaagaagattacctaaaatgtatttatgaactgggtca attagaccaaaaaattaccaataaactcatcgcagagaagatggccttct ccgcaccagccgtttccgaaatgctcaaaaaaatggtagccgaagagctc atttctaaggatgccaaggcaggttatctcctcagtcaaactgcccttga aatggtagccagcctctatcgcaaacaccgcttgattgaggtattcttag ttgagcaacttggctactctccagaagaagtacatgaagaggctgagatt ttagaacacaccgtttcagatcactttatcaatcgcctagacctgctact ggaacagcctcaaacttgtcctcacgggggaagcattcctcaagcaggac aaccgctcatcgaacgctaccagacacggctgtcacagctaactgagaca gggaactaccagcttgtccgtatccatgacttctatcaactccttcagta cttggaacaacatgaattagctgtcggtgatttactaaccgtcacagcct tcgaccagtttgcccagaccatcaccatccagtacaaggacaaagagctc gccgtcccaacagccatcgctcaacaattattcatcgaaaaaagcaatcg cccagcctaa The sequence of the S. suis ScaR protein is given below as SEQ ID No.: 4. [0000] SEQ ID NO: 4:  S. suis  ScaR MTPNKEDYLKCIYELGQLDQKITNKLIAEKMAFSAPAVSEMLKKMVAEEL ISKDAKAGYLLSQTALEMVASLYRKHRLIEVFLVEQLGYSPEEVHEEAEI LEHTVSDHFINRLDLLLEQPQTCPHGGSIPQAGQPLIERYQTRLSQLTET GNYQLVRIHDFYQLLQYLEQHELAVGDLLTVTAFDQFAQTITIQYKDKEL AVPTAIAQQLFIEKSNRPA [0038] The function and/or activity of the scaR protein is sensitive and/or response to environmental manganese concentrations. Without wishing to be bound by theory, manganese present in the environment, combines and forms complexes with ScaR; in S. suis , this results in a conformational change which allows ScaR to bind specific sequences within, or associated with, the promoter regions of target genes—for example, genes encoding ScaR-regulated microbial ( S. suis ) factors. As a result of the binding between ScaR/manganese complexes and sequences (for example scaR-specific nucleic acid motifs in the vicinity of promoted sequences) associated with ScaR regulated genes (encoding S. suis factors as described herein), transcription of these genes is modulated, in some cases inhibited, suppressed or prevented. While the production of internal and/or external microbial factors may be limited in manganese-rich environments, the growth of S. suis is strong and vigorous. [0039] In contrast, in environments where manganese is unavailable or where manganese concentrations are low, ScaR does not (or cannot) complex with manganese and remains in a confirmation that is unable to bind some target sequences. As such, in the absence of manganese, ScaR-regulated promoters are not impeded from initiating transcription. However, while microorganisms such as S. suis may be able to express certain internal and/or external factors (for example virulence determinants) in environments where metal ion (in particular manganese) availability is low, microbial growth may be poor. [0040] The inventors have discovered that S. suis ScaR-deficient strains, such as those described herein, are able to express certain factors independently of environmental manganese levels and are thus able to be cultured in manganese rich environments so as to markedly improve growth. In this way, standard laboratory culture conditions/media may be used to produce much higher amounts/concentrations of virulence factors than would otherwise be possible through culture of wild-type S. suis (i.e. scaR + strains) under equivalent conditions. [0041] In view of the above, the present invention provides modified S. suis which, under standard laboratory conditions is capable of expressing factors normally only expressed during an infection (i.e. in vivo). It should be understood that the term “standard laboratory conditions” may include environmental conditions comprising manganese and/or containing concentrations of manganese, sufficient to form ScaR/manganese complexes and inhibit or prevent expression of the factors described herein. [0042] Furthermore, modified S. suis as described herein, can be grown in the presence of manganese while still retaining the ability to express a number of virulence factors normally under the control of the scaR protein. This is important as the presence of manganese promotes strong growth of the modified S. suis provided by this invention. Furthermore, one of skill will appreciate that a modified S. suis strain which can be grown under conditions which promote strong/vigorous growth, may be particularly well suited to vaccine production where large amounts of microbial material are required to produce sufficient quantities of vaccine. [0043] Thus, an embodiment of this invention produces a S. suis scaR-deficient strain, wherein the strain expresses factors normally under the control of the ScaR protein, under conditions which comprise manganese concentrations sufficient to inhibit the expression of said factors in wild-type (or un-modified strains). [0044] It should be understood that this invention may extend to any Streptococcus species within the Streptococcus genus. For example, where the invention relates to S. equi , the modified microorganism may be a strain lacking a functional troR/TroR gene/protein or a troR/TroR-deficient strain. The invention may also provide a S. pyogenes lacking (functional) or deficient in, mtsR/MtsR; S. epidermidis lacking (functional) or deficient in, sirR/SirR; S. pneumoniae lacking (functional) or deficient in, psaR/PsaR; S. gordonii lacking (functional) or deficient in scaR/ScaR; and/or S. mutans lacking (functional) or deficient in, s/OR/SloR [0045] One of skill will appreciate that the modified (Streptococcus) microorganisms provided by this invention, may find application as strains from which vaccines may be produced. [0046] The modified microorganism is not a modified Corynebacterium . In a further embodiment, the microorganism is not a modified C. pseudotuberculosis. [0047] Accordingly, a second aspect of this invention provides a modified microorganism of the invention for use in raising an immune response in an animal. Moreover, the modified microorganisms described herein may be used to create vaccines for use in treating/preventing and/or controlling disease. [0048] The invention may further provide vaccines for use in treating, preventing and/or controlling diseases caused and/or contributed to by Streptococcus species. In one embodiment, the invention provides a Streptococcus suis scaR/ScaR-deficient strain for use in raising an immune response in an animal and/or for use as a vaccine. It should be understood that any Streptococcus deficient in a dtxR-like gene/protein (for example an S. equi troR-deficient strain) may be used in treating, preventing and/or controlling diseases caused and/or contributed to by Streptococcus species. [0049] It should be understood that the term “animal” may encompass mammalian animals including, for example, humans, equine, or ruminant (for example bovine, ovine and caprine) species, avian species and/or fish. [0050] Where the vaccine provided by this invention is based on modified organisms of the Streptococcus genus (for example a modified S. suis or S. equi ), the vaccine may find application in the treatment, prevention and/or control of diseases and/or conditions caused or contributed to by one or more Streptococci, including, for example meningitis, septicaemia, respiratory disease and/or strangles. [0051] One of skill will appreciate that the modified microorganism, for example a modified Streptococcus , provided by this invention, may be used as a whole-cell killed vaccine. In this embodiment, the vaccine may be prepared as a bacterin vaccine, comprising a suspension of killed modified microorganisms. In other embodiments, the vaccines may comprise portions and/or fragments of the modified Streptococcus , the portions or fragments being generated by fragmentation/fractionation procedures/protocols such as, for example, sonication, freeze-thaw, osmotic lysis and/or processes which isolate sub-cellular fractions or factors secreted by the modified microorganisms into the extracellular milieu. [0052] One of skill will appreciate that the general strategy of preparing a (bacterin) vaccine using a microorganism modified so as increase the expression of virulence factors when cultured (for example, under standard laboratory conditions (in the case of S. suis , such conditions comprising quantities of manganese sufficient to enhance or encourage growth), is somewhat at odds with routine protocols which aim to down regulate or attenuate microbial virulence factors before a microorganism is provided as a live attenuated (not killed) vaccine. [0053] A further aspect of the invention provides a method of making any of the vaccines described herein, said method comprising the step of culturing a modified microorganism provided by this invention and preparing a vaccine composition therefrom. Vaccine compositions according to this invention and/or prepared by methods described herein, may otherwise be known as “immunogenic compositions”—such compositions being capable of eliciting host immune responses. [0054] A method of making a modified S. suis for use in treating, preventing and/or controlling specific diseases (such as those described herein) may comprise culturing the scaR/ScaR-deficient S. suis strain described herein, under conditions which comprise manganese or manganese concentrations which would otherwise inhibit wild-type ScaR activity or function, and preparing a vaccine composition therefrom. Other streptococcal species may comprise metalo-regulatory factors which are “sensitive” to other types of metal ion—for example iron. In such cases, methods for making vaccines comprising modified forms of these species may exploit iron concentrations which would otherwise alter wild-type activity and/or function of the metallo-regulatory protein such that expression of target genes (for example genes encoding virulence factors) is modified/altered (for example inhibited or reduced). [0055] Vaccine compositions of this invention may comprise killed forms of any of the modified microorganisms described herein and/or fragments and/or portions derived from modified microorganisms of this invention. The vaccines of this invention may be formulated together, or in combination with one or more adjuvant(s), microbial components (for example one or more bacterium or a component thereof), viral components, parasitic components, pharmaceutically acceptable carrier(s), excipient(s) and/or diluent(s). [0056] Vaccines may be formulated and/or prepared for parenteral, mucosal, oral and/or transdermal administration. Vaccines and/or immunogenic compositions for parenetral administration may be administered interdermally, intraperitoneally, subcutaneously, intravenously or intramuscularly. [0057] The inventors have determined that the vaccines provided by this invention, particularly vaccines comprising the modified Streptococcus organisms described above, have a number of advantages over existing vaccines. In particular, vaccines comprising the modified Streptococcus strains of this invention, exhibit superior efficacy, as the enhanced expression of virulence factors improves immune reactions within the animal or human host and need to improve protective immunity. [0058] Moreover, production of the vaccine is simple and requires established, defined and well understood (i.e. standard) culture conditions. Additionally, by avoiding the need to alter the culture conditions (relative to culture of, for example, a wild-type strain), vaccine production is safe, simple and rapid. Moreover, since the vaccine strain is used in a killed, whole-cell form, this further simplifies the production procedure and results in a safe vaccine which can readily be combined with other killed, whole-cell type vaccines, vaccines derived from portions and/or fragments of other microorganisms (for example toxoid vaccines) as well as other forms of medicament. [0059] One of skill will appreciate that animal vaccines are subject to withdrawal periods—i.e. the period of time an animal (or products from an animal such as milk) cannot enter the human food chain following vaccination. The withdrawal period can hinder normal farming practises and result in lost production. It is not expected that a withdrawal period will be required with bacterin (comprising a suspension of killed wild-type or modified microorganisms) type vaccine. [0060] Following vaccination with a whole-cell killed microorganism-derived vaccine, it is often difficult to distinguish vaccinated and infected subjects. This is particularly true where both the vaccine and wild-type strains of a particular microorganism produce antigens which may be used to detect the microorganism or diagnose an infection therewith. [0061] As such, the modified microorganisms provided by this invention may be further adapted to permit detection in a sample. For example, the modified microorganisms may comprise a detectable marker which may be exploited in a diagnostic procedure to detect or confirm the presence of a modified microorganism of this invention. One of skill will appreciate that the presence of a detectable marker in a modified microorganism of this invention would permit the identification of hosts (human or animal) which have been vaccinated with any of the modified microorganisms described herein. [0062] The modified microorganisms of this invention may be supplemented with one or more detectable factors. In one embodiment, the detectable factor may comprise a gene and/or protein encoding a detectable factor, wherein the gene and/or protein has been introduced to a modified microorganism described herein. Genes and/or proteins of this type may be referred to as “marker genes and/or proteins”. [0063] By way of example, a marker gene and/or protein may be introduced or delivered to a microorganism by way of a vector (for example an expression vector) such as, for example, a viral vector or a plasmid. The introduction and/or delivery of vectors to the modified microorganisms of this invention may be achieved using standard laboratory cloning procedures including those detailed in Molecular Cloning : A laboratory Manual; Sambrook and Green, Cold Spring Harbor Laboratory Press. [0064] One of skill will appreciate that modified microorganisms further modified to include some form of detectable marker may be identified and/or detected in samples by virtue of the detectable marker. In other words, a positive identification of the detectable marker in a sample may confirm the presence of a modified microorganism of this invention. [0065] The detectable marker may comprise a gene and/or protein which has been modified or deleted from the genome of the modified microorganism—the gene and/or protein encoding a detectable factor. One of skill will appreciate that just as the presence of a particular marker from a sample may serve to verify the presence of a modified microorganism of this invention, the absence of a particular marker from a sample, or the presence of a modified form of a particular marker from a sample, may also serve as a means to diagnose the presence of a modified microorganism of this invention. [0066] Modified microorganisms of this invention may be further modified so as to not comprise, produce or express at least one detectable factor. In some embodiments, the detectable factor may form the basis of a standard diagnostic test. [0067] The detectable factor may comprise or be an immunogenic protein. Advantageously, the detectable factor is one which forms the basis of a diagnostic test. [0068] The invention provides a modified microorganism according to this invention, which modified microorganism comprises a further modification which renders it unable to express at least one other detectable factor. [0069] One of skill will appreciate that provided the at least one other detectable factor is a factor which can be detected by some means—for example by immunological assays (for example ELISA) or molecular detection assays (for example PCR-based assays), it is possible to use the presence or absence of such a factor from samples provided or obtained from subjects to be tested, as a means of determining whether or not that subject is infected with a wild-type form of the modified microorganism (which would be expected to express the detectable factor), or has been vaccinated with the modified strain (which would have been modified to exhibit inhibited (or ablated) expression of the detectable factor). Being able to make such a distinction is important as it prevents vaccinates being mis-diagnosed as infected subjects. [0070] The diagnostic factor may be a factor used to detect instances of infection and/or disease, caused and/or contributed to by wild-type strains of the modified microorganisms. Advantageously the diagnostic factor is an antigenic and/or immunogenic factor, and in some embodiments, the diagnostic factor may be a secreted factor. [0071] The modified microorganisms provided by this invention may further comprise one or more detectable marker or reporter elements. The presence of such elements may further serve to distinguish vaccine strains from wild-type strains. Markers and/or reporter elements which are useful in this invention may include, for example, optically-detectable markers such as fluorescent proteins and the like. [0072] One of skill will appreciate that while this invention relates to modified forms of Streptococci microorganisms, the teachings may be applied to other species (including species from other genera). For example, the term “modified microorganisms as used herein) may encompass modified Mycobacteria , for example modified M. tuberculosis , wherein the modified M. tuberculosis comprises a modified ideR gene and/or IdeR protein—the ideR gene and/or IdeR protein being a dtxR/DtxR homologue. DETAILED DESCRIPTION [0073] The present invention will now be described in detail with reference to the following Figures which show: [0074] FIG. 1 . PCR verification of a Streptococcus suis ΔscaR mutant. Panel A: PCR using primers flanking the deleted portion of scaR allowed amplification of an expected full-sized gene fragment (1,066 bp) from the wild-type parent strain and a shorter fragment (654 bp) from the ΔscaR mutant strain, confirming the deletion was correct and of the expected size. Lanes are annotated as shown. Panel B: PCR using primers specific for an internal portion of scaR allowed amplification of the expected sized fragment (561 bp) from the wild-type parent strain and confirmed the absence of the equivalent sequence in the ΔscaR mutant strain. Lanes are annotated as shown. Panel C: PCR analysis of the pG + host9-encoded erythromycin resistance gene (˜800 bp) confirmed the absence of plasmid sequences from the ΔscaR mutant strain. Lanes are annotated as shown. [0075] FIG. 2 . Western blot analysis of secreted proteins in a wild-type Streptococcus suis and isogenic ΔscaR deletion mutant. Strains were cultured in either THB or CDM before culture supernatants were TCA precipitated, separated by SDS-PAGE and then transferred onto Hybond ECL nitrocellulose membranes (Amersham Biosciences). Primary antibody (polyclonal IgG antibodies derived from convalescent pig serum following S. suis infection) was diluted 1:500 and rabbit anti-porcine IgG HRP conjugated secondary antibody (Sigma-Aldrich) was diluted 1:10,000. Immunodominant proteins were detected by ECL (Amersham-Biosciences) and images were captured using ImageQuant LAS4000 (GE Healthcare). [0076] FIG. 3 : Shows the mean rectal temperature data over the study period. The control animals were injected with sterile phosphate buffered saline at Day 0 and 28, and the vaccinated group were injected with an adjuvanted bacterin vaccine derived from a scaR mutant of S. suis at the same times. All animals were challenged with a wild type S. suis strain on Day 42. [0077] FIG. 4 . PCR analysis of the Streptococcus equi ΔtroR mutant strain. [0078] Panel A: PCR with the primers ΔtroR_ext_fwd and ΔtroR_ext_rev, which flanked the deleted portion of troR, allowed amplification of an expected full-sized gene fragment (519 bp) from the wild-type parent strain (WT) and a shorter fragment (220 bp) from the ΔtroR mutant strain (ΔtroR), confirming that the mutation was correct and of the expected size. The recombinant plasmid pGh9-ΔtroR (Control) was included as a positive control. Panel B: PCR with the primers ΔtroR_int_fwd+ΔtroR_int_rev, specific for an internal portion of troR, allowed amplification of the expected sized fragment (253 bp) from the wild-type parent strain and confirmed the absence of the equivalent sequence in the mutant strain (ΔtroR). The recombinant plasmid pGh9-ΔtroR (Control) was included as a negative control. Panel C: PCR with the primers pGh9_erm_fwd+pGh9_erm_rev, specific for the pG + host 9-encoded erythromycin resistance gene (erm; ca. 0.8 kb) confirmed the absence of this gene, and hence plasmid sequences from the mutant strain (ΔtroR). The recombinant plasmid pGh9-ΔtroR (Control) was included as a positive control. [0079] FIG. 5 . Western blot analysis of secreted proteins in a wild-type Streptococcus equi and isogenic troR deletion mutant (ΔtroR). Strains were cultured in VPB before culture supernatants were precipitated, separated by SDS-PAGE and then transferred onto Hybond ECL nitrocellulose membranes (Amersham Biosciences). Primary antibody (polyclonal IgG antibodies derived from convalescent horse serum following S. equi infection) was diluted 1:500 and rabbit anti-horse IgG HRP conjugated secondary antibody (Sigma-Aldrich) was diluted 1:10,000. Immune-reactive proteins were detected by ECL (Amersham-Biosciences) and images were captured using an ImageQuant LAS4000 (GE Healthcare). Example 1 Material, Methods and Results General Molecular Biological Techniques and Targeted Allele-Replacement Mutagenesis [0080] Routine molecular biological manipulations were conducted as described (Sambrook et al., 1989). Transformation of E. coli and Streptococcus suis with plasmid DNA was conducted using standard procedures (Fontaine et al., 2004; Sambrook et al., 1989). Oligonucleotide primers used for PCR are described in Table 2. [0000] Construction of a scaR (dtxR-Like Transcriptional Regulator) Mutant in Streptococcus suis [0081] A defined scaR mutant was constructed in Streptococcus suis type strain 9682 (DSMZ). In brief, 5′ (DNA fragment A comprising 559 bp of upstream flanking sequence up to and including the translational ATG start codon of scaR) and 3′ (DNA fragment B comprising 506 bp of downstream flanking sequence encompassing the translational TAA stop codon of scaR and subsequent downstream sequence) chromosomal regions flanking the scaR gene were amplified by PCR with Phusion polymersase (Fiinzyme) in accordance with the manufacturer's guidelines using the primers detailed in Table 2. A 12 bp complementary nucleotide overlap sequence was engineered into the internal reverse primer of fragment A (Table 2) and internal forward primer of fragment B (Table 2) to increase the specificity and efficiency of the final spliced PCR reaction. The resultant amplicons (fragments A+B) were then used as a DNA template in a third cross-over PCR reaction, and the resulting DNA fragment (Fragment C) was cloned into the temperature-sensitive allele-replacement plasmid, pG + host 9, by virtue of primer-encoded EcoRI restriction endonuclease recognition sites. The resulting construct was designated pGh9-ΔscaR. The wild-type Streptococcus suis strain was subsequently transformed with pGh9-ΔscaR and allele replacement was conducted in an equivalent manner to that described (Fontaine et al., 2003). Following the two-step mutagenesis procedure, bacteria were plated onto solid media and potential scaR mutants were screened and verified by PCR using the primers detailed in Table 2. As expected, these primers resulted in the amplification of a ca. 1006 bp fragment from the wild-type strain; however, the equivalent PCR product for the ΔscaR strain was ca. 654 bp shorter, confirming deletion of the chromosomal scaR gene ( FIG. 1 , panel A). Further verification using internal scaR primers confirmed that the scaR gene was absent in the mutant strain ( FIG. 1 , panel B). An additional verification PCR to test for the presence of the plasmid derived erythromycin resistance gene confirmed there was no plasmid present in the scaR deletion mutant ( FIG. 1 , panel C). Finally, the region spanning the deleted scaR gene was PCR amplified and confirmed by sequencing (data not shown). [0000] TABLE 2 PCR mutagenesis and verification primers Primer purpose* Sequence (5′-3′) † Reference Amplification of scaR flanking regions scaR upstream flank F GG GAATTC GCTACAGCTACAGCTGACTTG This study scaR upstream flank R CGCTCAGCTTGTTTACATGAGAACTCGCTTT C scaR downstream flank F GAAAGCGAGTTCTCATGTAAACAAGCTGAGC This study scaR downstream flank R G GG GAATTC GACGAATGACGGATACTATC Screening and verification of scaR mutagenesis construct and deletion mutant pGh + 9 MCS screen F CCAGTGAGCGCGCGTAATACG This study pGh + 9 MCS screen F GGTATACTACTGACAGCTTCC scaR external screen F CACAGCCACTCTTGGC This study scaR external screen R GTCTTGCAGCCTTTAACC scaR internal screen F GAACTGGGTCAATTAGACC This study scaR internal screen R GAGCTCTTTGTCCTTGTAC pGh9 +  erm screen F TGGAAATAAGACTTAGAAGC This study pGh9 +  erm screen R CGACTCATAGAATTATTTCC *Forward primers are denoted F and reverse primers are denoted R † Underlined sequences denote EcoRI restriction sites Immunological Detection of S suis Secreted Proteins Using Porcine Convalescent Anti- S. suis Antibodies [0082] In order to determine whether the abrogation of production of ScaR in the Streptococcus suis ΔscaR mutant affected the production, in vitro, of proteins normally produced in vivo during infection, a Western blot was performed using serum from a piglet challenged with Streptococcus suis . Both the scaRScaR mutant and wild-type parent strains were cultured in Todd-Hewitt Broth+1% (w/v) yeast extract (THB) or in a chemically-defined medium (CDM; Walker et al., 2011). Once mid-logarithmic growth-phase was reached, culture volumes were adjusted by measurement of absorbance at 600 nm, so that equivalent cell numbers were recovered for wild-type and mutant strains. Subsequently, cells were harvested by centrifugation and supernatant proteins were retained for further analysis. A known quantity of bovine serum albumin (BSA) was added in equivalent amounts to wild-type and mutant culture supernatants, which were then TCA-precipitated and dissolved in 1.5 M Tris-HCl (pH 7.5); the BSA subsequently served as an internal control to confirm equivalent recovery of proteins from wild-type and mutant supernatants following TCA precipitation. Equivalent volumes of wild-type and mutant-derived supernatant proteins were separated by electrophoresis through a 12% SDS-polyacrylamide gel and visualised by staining with Coomassie; equivalent amounts of BSA were observed between samples, however, several differences were observed between the secreted protein profiles of both strains (data not shown). These differences were further investigated by Western blot using polyclonal IgG antibodies derived from convalescent pig serum following S. suis infection. Results confirmed that the expression of numerous proteins was greater in the ΔscaR mutant as compared to the wild-type parent strain ( FIG. 2 ), and equivalent results were observed for both THB and CDM-cultured bacteria. It was therefore concluded that the abrogation of production of the DtxR-like protein, ScaR, in Streptococcus suis resulted in the de-repression of some genes which are normally repressed during culture in artificial laboratory media. Example 2 9.1 Summary of Study Design [0083] A total of eighteen piglets of 4 weeks of age were sourced from a high health status farm and housed as two groups of nine. At approximately 4 weeks of age, a blood sample was collected from each animal then one group was administered phosphate buffered saline and the other administered a formalin killed suspension of the scaR-deficient S. suis strain adjuvanted with aluminum hydroxide by intramuscular injection. These procedures were repeated four weeks later on Day 28. On Day 42, two weeks post-booster vaccination, a blood sample was collected from each animal then they were administered 5 ml of 1% acetic acid by intranasal delivery followed 1 hour later by a 5 ml volume of the challenge material by intranasal delivery at a concentration of 2×10 8 cfu/ml. A clinical observation was carried out on the animals prior to challenge then as a minimum twice daily, for seven days. On Day 49 (or earlier if animals were euthanased early on welfare grounds) the animals were euthanased and a blood sample was collected. At necropsy samples of the brain and tonsils were removed for bacteriological assessment to determine whether the challenge isolate was present. A summary of the study design can be seen in Table 3. [0000] TABLE 3 Summary of Treatment Groups Dosage/ Regime Challenge Concentration End of Group No. Treatment Route (Days) (Day 42) Volume (cfu/ml) Study 1 9 Phosphate 1 ml/IM 0 + 28 Streptococcus 5 ml 1.55 × 10 8 Day 49 buffered suis , saline Serotype 2 2 9 Vaccine 1 ml/IM 0 + 28 Streptococcus 5 ml 1.55 × 10 8 Day 49 suis , Serotype 2 IM = Intramuscular Test Material [0000] Name: Streptococcus vaccine* Dose Regime: 1 ml on two occasions (Day 0 and 28), 4 weeks apart *A defined scaR mutant constructed using Streptococcus suis type strain 9682 that has been formalin killed and adjuvanted with alhydrogel Control [0000] Name: Sterile Phosphate Buffered Saline (PBS) Dose Regime: 1 ml on two occasions (Day 0 and 28), 4 weeks apart Challenge Material [0000] Name: Streptococcus suis , Serotype 2 Method of Administration: Intra-nasal Anticipated Titre: 2×10 8 colony forming units (cfu) total in 5 ml Dose Regime: 5 ml on single occasion (Day 42) Test Material Administration [0092] On Day 0, the animals from Group 1 were administered 1 ml of the control material by intramuscular injection to the right neck. All animals from Group 2 were administered 1 ml of the vaccine by intramuscular injection to the right neck. On Day 28, the animals from Group 1 were administered 1 ml of the control material by intramuscular injection to the left neck. All animals from Group 2 were administered 1 ml of the vaccine by intramuscular injection to the left neck. A new needle and syringe was used for each animal. Challenge Preparation [0093] On Day 41, a microbank seed stock cryovial containing the challenge isolate was removed from −70° C. storage and placed in a pre-chilled (−70° C.±10° C.) cryoblock which was transported directly to a Microbiological Class 2 hood. Two beads were removed from the vial and streaked onto separate 5% Sheep Blood agar plates. The plates were incubated overnight for 23 hours at 37° C. Following incubation, plates were examined and confirmed as having growth consistent with that expected for the isolate. Colonies were removed from each plate and added to 4×3 ml of pre-warmed vegetable peptone broth (VPB) in bijou bottles to a turbidity of 1.5 McFarland turbidity units (McF) (density measured using a Densitometer, BioMerieux). Each 3 ml volume was added to 97 ml of pre-warmed VPB. The cultures were incubated for four hours at 37° C. on an orbital shaker set at 150 rpm. After incubation the turbidity of each culture was recorded (target was between 2.5 and 3.5 McF). 80 ml of one culture broth was removed and added to 120 ml of VPB to produce challenge material with a concentration of approximately 2×10 8 cfu/ml (1×10 9 cfu total in 5 ml). The challenge material was stored chilled prior to use (+2 to +8° C.). A sample of the pre and post challenge material (pooled challenge broth pre and post challenge) was used for the measurement of bacterial concentration. Clinical Observations [0094] On Day 42, clinical observations were conducted prior to challenge then as a minimum twice daily from Day 43 until the end of the study. Additional observations were conducted as necessitated by the condition of the animals. Clinical observations consisted of assessments of demeanour, behavioural/central nervous system changes and rectal temperature (° C.) according to a scoring system (see Table 4). Additional comments relating to behavioural or neurological issues were recorded as comments. [0000] TABLE 4 Clinical Observations Score Parameter 0 1 2 3 Rectal Temp 38.0° C.-39.5° C. >39.5° C.-40.0° C. >40.0° C.-40.9° C. ≧41.0° C. or <38° C. Demeanour Normal Mild Moderate Severe Depression Depression Depression Description Normal A bit dull but Unwilling but Unable to rise Demeanour active and able to rise, mobile staying apart from others Behavioural/CNS Normal Minor Changes Moderate Severe Changes Changes Description Normal Lameness, Unsteady when Paralysis, Demeanour tremors walking, involuntary uncoordinated, muscle walking on front movement knees [0095] Pigs which were recumbent/moribund and/or showing signs of severe distress were euthanased immediately on humane grounds by intravenous/intraperitoneal administration of a lethal dose of Pentobarbitone Sodium BP, using a suitably sized sterile syringe and sterile needle. Necropsy [0096] On Day 49 (or as required following early euthanasia on welfare grounds), animals were euthanased by lethal injection. A gross pathological examination of each carcass was conducted. Samples were collected as detailed below (see “Tissue samples”. Tissue Samples [0097] At necropsy, tissue and brain samples were removed from each animal. Two samples were removed for each tissue type. One was placed in a container along with 10% formal saline for histopathological analysis, the second was placed in a sterile container for bacteriological assessment. All samples were removed using sterile forceps and scalpels to reduce risk of contamination between animals. The samples for bacteriological assessment were transported to the laboratory where they were processed on the day of collection as detailed below. The samples in formol saline were stored at ambient temperature prior to examination as detailed below under “Histological analysis”. [0000] S. suis Culture from Tissue Samples [0098] Each tissue sample was weighed, placed in a separate stomacher bag together with 9.0 ml of peptone water to provide a nominal dilution of 10 −1 and homogenised for 30 seconds in a Seward “Stomacher 80” set at high speed. The homogenate was poured into a sterile Universal Bottle labeled the 10 −1 dilution. A 20 μl aliquot of homogenate was diluted in 180 μl of peptone water in a sterile U-well micro titration plate to give a 10 −2 dilution. This dilution process was repeated until the homogenate was diluted to 10 −7 . Duplicate 10 μl aliquots of each homogenate dilution from 10 −1 to 10 −7 were placed on the surface of a well dried 5% sheep blood agar plate. After samples are dry the plates were incubated overnight (20 to 24 hours) at 37° C. (±2° C.). Plates were inspected for typical colonies of S. suis . If present, colonies were counted. Histopathological Analysis [0099] A total of ten sets of tissues (three from early deaths, four from controls and three from vaccinates were processed and examined following standard procedures [0000] TABLE 5 Summary of study schedule Table 5: Study Schedule Study Day Procedure Day 0 (Pre-Treatment) Arrival, Blood Sample. Vet inspection Day 0 Administration of Vaccine/Saline Day 28 Blood Sample, Administration of Vaccine/Saline Day 42 Blood Sample, Clinical Observations, Pre- Challenge Primer (Acetic acid) Day 42 (+1 hour) Challenge Day 42 - 49 Clinical Observations Day 49 Necropsy Results Rectal Temperature Data: [0100] The rectal temperature data is summarised in FIG. 3 . There is a considerable difference between the mean rectal temperatures when the results for the controls and vaccinates are compared. During the period between Day 44 pm and Day 46 pm the difference between the groups is around 1° C. This period (between 2 and 4 days post challenge) is the peak period for infection and this is shown by the differences between the groups. A total of 27 individual observations of rectal temperatures in excess of 39.5° C. were recorded for the control animals compared to none for the vaccinates. On Day 46 am all of the control animals had temperatures in excess of 39.5° C. Behaviour and Demeanour: [0101] Only three animals (all from the control group) were recorded to have abnormal behaviour and demeanour during the study and all three animals were subsequently euthanased on welfare grounds. No vaccinate animals were observed to have any abnormal signs at any point during the monitoring period. On Day 45 (pm) Animal no. 0252 was observed to have tremors, was unsteady on its feet and appeared to be having fits, combined with a temperature of 39.7° C. On Day 46 at the morning clinicals, Animal no. 0254 was observed to be showing early signs of the disease with some lameness and minor tremors as well as a slightly depressed demeanour and a temperature of 40.4° C. Approximately 4 hours later, the animal had a temperature of 40.8° C., as well as a hunched appearance, tremors, unsteadiness and some seizures. The animal was euthanased on welfare grounds. On Day 47, Animal no. 0251 was observed to have a temperature of 40.4° C., was unable to rise, was fitting and was euthanased on welfare grounds. Mortality: [0102] The mortality rate in the vaccinate group was 0% (0 out of 9) compared to 33.3% (3 out of 9) in the control group. Summary of Clinical Scoring: [0103] No observations of any clinical symptoms were recorded at any stage in the vaccinate group. Only three of the control animals developed clinical symptoms following challenge, all of which were euthanased on welfare grounds. The remaining six animals in the control group all had rectal temperatures in excess of 39.5° C. on at least one occasion post challenge, suggesting that the bacteria was active within the animals, perhaps indicating a sub clinical infection, however none of these animals went on to develop clinical disease within the experimental timeframe. Bacteriology [0104] A summary of the bacterial findings is shown in Table 6. [0000] TABLE 6 Bacterial recovery from tissue samples Brain Sample Tonsil Sample Animal No. Group No. (cfu/ml) (cfu/ml) 0251 1 1.29 × 10 4 4.48 × 10 6 0252 1 1.67 × 10 6 2.92 × 10 6 0254 1 1.02 × 10 4 1.52 × 10 7 0256 1 0 2.29 × 10 5 0253 1 1.06 × 10 3 0 [0105] Streptococcus suis was recovered from both of the tissue samples collected from the three control animals that were euthanased prior to Day 49. A further 2 animals from the control group were also observed to have bacteria present in one tissue. The challenge bacteria could not be confirmed as present in any of the samples from the vaccinate group. The tonsil samples for the majority of the animals were heavily contaminated with other bacteria to relatively high levels and it is therefore not possible to confirm whether any of the challenge bacteria was present at lower levels. The brain samples were however clean with few if any, other bacteria present and these samples at least can be confirmed as S. suis free. [0106] It is apparent from the data that in order for a full clinical disease to occur, sufficient numbers of S. suis must be present in the brain. Histopathology [0107] A total of 10 sets of samples (brain and tonsil samples from each animal) were examined. These samples consisted of 3 animals from the vaccinated group and 7 animals from the control group (three animals which were euthanased early and four animals which were euthanased at the end of the study, but had shown no signs of clinical disease other than a transient rectal temperature increase). The results of the examination are provided in Appendix 4a and 4b and are summarised below. The three animals from the control group that were euthanased on welfare grounds prior to the end of the study were all observed to have severe active sub acute or chronic active generalised meningitis with extension into the brain along with severe chronic active necro-superative tonsillitis. These signs are consistent with infection with Streptococcus suis . Of the remaining four control animals, two were observed to have a single small focus of lymphocytes present in the brain although this was not considered to be significant, the other two along with the three vaccinate animals had no significant lesions present in the brain. The tonsil samples for these seven animals (four controls and three vaccinates) were all active with large secondary follicles and tonsilar crypts containing necrotic material, macrophages and polymorphonuclear neutrophils with colonies of small bacterial cocci. In all cases however there was no evidence of infection in the brain and the tonsilar lesions were considered to be normal for conventionally raised pigs. Discussion [0108] The objective of the study was to determine whether the Streptococcus vaccine was efficacious in the control of an artificial Streptococcus suis challenge in pigs of approximately 10 weeks of age. The results of the study provide indications that the vaccine has efficacy in the prevention of the disease. No animals from the vaccinated group were observed to show any signs of clinical or sub-clinical disease during the study and all rectal temperatures stayed below 39.5° C. (considered to be the cut off for normality in pigs of this age) and no bacteria could be recovered from the tissue samples collected at post mortem. In comparison all of the control animals were recorded to have increased rectal temperatures during the study (indicative of infections or sub-clinical disease) on at least one occasion and three of them developed an acute clinical Streptococcus suis infection and were subsequently euthanased. The mortality in the control group was 33.3% and while this is not as high as had been anticipated (potentially due to animals of this age being better able to fight off the infection than younger animals), the results are still comprehensive. [0109] The results show that the vaccine offered some protection against the challenge. Example 3— Streptococcus equi Materials & Methods Molecular Biological Techniques. [0110] Routine molecular biological manipulations were conducted as described (Sambrook et al., 1989). Transformation of Escherichia coli and Streptococcus equi with plasmid DNA was conducted using standard procedures (Sambrook et al., 1989; Fontaine et al., 2004). Oligonucleotide primers used for PCR are described in Table 7. [0000] TABLE 7 PCR mutagenesis and verification primers Primer name Description/purpose Sequence (5′-3′) † Amplification of troR flanking regions 5′-ΔtroR_fwd Amplification of 5′- CG GAATTC CTTTCACCTTCTAGGTAAATCACATCAATACC 5′-ΔtroR_rev troR and upstream GCACCCTGCGGTCTTATCCTTTACAATCCAGCCTTGTGC flanking sequence 3′-ΔtroR_fwd Amplification of 3′- GATAAGACCGCAGGGTGCATGATCACTTTGAGCTTATCC 3′-ΔtroR_rev troR and downstream CG GAATTC GTGATGTTGTTGTTGCTGATCGCTTGGTGTATC flanking sequence Screening and verification of troR mutagenesis construct and deletion mutant ΔtroR_ext_fwd Amplification of troR GCAGAGAGAATGAAGGTTTCTGCAC ΔtroR_ext_rev fragment for mutant CAATTCCTTATCTGCATAAGTGATGG screening. Primers anneal within region ΔtroR_int_fwd Amplification of CTATTATCTAACAGAGCAAGGGCAG ΔtroR_int_rev internal troR fragment TGTTTTGTTGATTTCGATTAGTGG for mutant screening pGh9_erm_fwd Amplification of TGGAAATAAGACTTAGAAGC pGh9_erm_rev pG + host 9 erm gene CGACTCATAGAATTATTTCC † Underlined sequences denote EcoRI restriction sites ‡ Multiple Cloning Site (MCS) Construction of a troR Mutant of Streptococcus equi. [0111] A defined troR mutant (a partial, 358 bp, in-frame deletion of the troR gene, designated ΔtroR) was constructed in Streptococcus equi subspecies equi strain 4047 (obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures). Briefly, two DNA fragments were amplified from the S. equi chromosome by PCR using the primers 5′-ΔtroR_fwd+5′-ΔtroR_rev (Fragment A) and 3′-ΔtroR_fwd+3′-ΔtroR_rev (Fragment B); Fragment A comprised 708 bp of S. equi troR upstream flanking sequence, including the first 139 nucleotides of troR, while Fragment B comprised 680 bp of troR downstream flanking sequence, including the last 182 bp of troR (nucleotide positions 467-648 bp). An 18 bp complementary nucleotide overlap sequence was engineered into 5′-ΔtroR_rev and 3′-ΔtroR_fwd to increase the specificity and efficiency of a subsequent spliced PCR reaction. The resulting amplicons (Fragments A+B) were then used as DNA template in a third PCR using primers 5′-ΔtroR_fw+3′-ΔtroR_rev, and the resulting DNA fragment (Fragment C) was cloned into the temperature-sensitive allele-replacement plasmid, pG + host 9, by virtue of primer-encoded EcoRI restriction endonuclease recognition sites, to create the recombinant plasmid pGh9-ΔtroR. The wild-type Streptococcus equi strain 4047 was transformed with pGh9-ΔtroR and allele-replacement mutagenesis was conducted as described previously (Fontaine et al., 2003). Following the mutagenesis procedure, bacteria were plated onto solid growth media and potential troR mutants were screened by PCR to identify the desired mutant. PCR with the primers ΔtroR_ext_fwd+ΔtroR_ext_rev, which flank troR, were used to confirm the presence of a deletion within the S. equi troR gene, as was evidenced by the amplification of a ca. 0.5 kb fragment from the wild-type strain and a ca. 0.2 kb fragment from the mutant strain ( FIG. 4 , Panel A). In addition, PCR with the primers ΔtroR_int_fwd+ΔtroR_int_rev, which amplify a ca. 0.25 kb region of troR which is absent within the deletion derivative, confirmed the absence of this region in the mutant strain ( FIG. 4 , Panel B). Finally, PCR using the primers pGh9_erm_fwd+pGh9_erm_rev, which amplify a portion of the erythromycin resistance determinant (erm) of pG + host 9, failed to detect this sequence confirming that the plasmid had been lost from the chromosome ( FIG. 4 , Panel C). The region spanning the deleted troR gene was then amplified by PCR and sequenced to confirm that the mutation was as expected (data not shown). [0000] Immunological Detection of S. equi Secreted Proteins by Convalescent Serum from a Horse with Strangles. [0112] In order to determine whether the abrogation of production of TroR in the Streptococcus equi ΔtroR mutant affected the production, in vitro, of proteins normally produced in vivo during infection, a Western blot was performed using serum from a horse that had recovered from strangles infection. Both the troR mutant and wild-type parent strain were cultured in TSE compliant Veggitone Vegetable Peptone Broth (VPB). Once mid-logarithmic growth-phase was reached, culture volumes were adjusted by measurement of absorbance at 600 nm, so that equivalent cell numbers were recovered for wild-type and mutant strains. [0113] Subsequently, cells were harvested by centrifugation and supernatant proteins were retained for further analysis. A known quantity of bovine serum albumin (BSA) was added in equivalent amounts to wild-type and mutant culture supernatants, which were then TCA-precipitated and dissolved in 1.5 M Tris-HCl (pH 7.5); the BSA subsequently served as an internal control to confirm equivalent recovery of proteins from wild-type and mutant supernatants following TCA precipitation. Equivalent volumes of wild-type and mutant-derived supernatant proteins were separated by electrophoresis through a 12% SDS-polyacrylamide gel and visualised by staining with Coomassie Brilliant Blue stain; equivalent amounts of BSA were observed between samples; however, several differences were observed between the secreted protein profiles of both strains (data not shown). These differences were further investigated by Western blot using polyclonal IgG antibodies derived from convalescent equine serum following natural S. equi infection. Results confirmed that the expression of some proteins was greater in the ΔtroR mutant as compared to the wild-type parent strain ( FIG. 5 ) implying de-repression of target genes as a result of the genetic disruption of troR. REFERENCES [0000] Fontaine, M C., Lee J J and Kehoe M (2003). Combined contributions of streptolysin O and streptolysin S to virulence of serotype M5 Streptococcus pyogenes strain Manfredo. Infect Immun 71(7): 3857-3865. Fontaine M C, Perez-Casal J, Willson P J (2004). Investigation of a novel DNase of Streptococcus suis serotype 2 . Infect Immun 72(2):774-81. Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989) Molecular Cloning : A laboratory manual, 2nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., pp 1.63-1.70. Walker C A, Donachie W, Smith D G, Fontaine M C. (2011). Targeted allele replacement mutagenesis of Corynebacterium pseudotuberculosis. Appl Environ Microbiol 77(10): 3532-3535. Sambrook, J. and Russell, D. W. 2001. Molecular cloning: a laboratory manual, 3rd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. Fontaine, M. C., Perez-Casal, J. and Willson, P. J. 2004. Investigation of a novel DNase of Streptococcus suis serotype 2 . Infect Immun 72(2):774-81.

The present invention is based on the finding that microorganisms can be modified so as to express certain factors important in generating or raising host immune responses. In particular, the invention provides modified microorganisms which, when subjected to conditions which would be expected to suppress or reduce the expression, function and/or activity of certain factors, exhibit increased (often significantly increased) expression, function and/or activity of those factors. The invention provides a modified microorganism capable of expressing at least one factor under conditions in which a wild-type (or unmodified) strain of the same microorganism, exhibits inhibited expression of the at least one factor.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of Korean Patent Application No. 2002-71965, filed Nov. 19, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a spindle motor for a hard disc drive, and particularly, to a spindle motor for a hard disc drive having an oil outflow prevention apparatus preventing outflow of oil from a fluid dynamic bearing used in the spindle motor. [0004] 2. Description of the Related Art [0005] In general, a spindle motor, used in a hard disc drive, having a large capacity and a high rotational speed, utilizes a fluid dynamic bearing having less driving friction than a ball bearing for reducing noise and non-repeatable run-out (NRRO) in the hard disc drive. The fluid dynamic bearing forms an oil film between a rotating member and a fixed member, and is able to support the rotating member with pressure generated during rotation. Accordingly, the rotating member and the fixed member can be kept from direct contact, and frictional resistances can be reduced. In order to effectively generate a required pressure to form the oil film, a groove, used in generating dynamic pressure, is formed, e.g., in a spiral pattern, on the rotating member and at least one side of the fixed member. [0006] Accordingly, a radial bearing having a groove used in generating dynamic pressure is formed on a circumferential surface so that oil in bearing clearances, with respect to a sleeve, can support a load in the radial direction of the shaft with the dynamic pressure generated by the groove. Further, a thrust bearing, having grooves used in generating dynamic pressure, is formed on upper and lower surfaces of a thrust plate so that oil in bearing clearances, with respect to a shaft and a sleeve, can support a load in the axial direction of the shaft. The dynamic pressure generated by the grooves facilitates stable operations. [0007] [0007]FIG. 1 is a side, cross-sectional view of a conventional spindle motor having a radial bearing, as well as a thrust bearing, to support loads in the radial and axial directions of a shaft thereof. [0008] Referring to FIG. 1, bearing clearances are provided between a shaft 150 and a sleeve 130 of a spindle motor 100 . Grooves 131 , used in generating dynamic pressure, are formed at upper and lower sections of the inner circumferential surface of the sleeve 130 . [0009] A base 110 is positioned at a lower section of the shaft 150 , and a thrust plate 151 and a thrust flange 153 are mounted on the base 110 . Although not shown in FIG. 1, grooves (not shown) used in generating dynamic pressure between the thrust plate 151 , the thrust flange 153 , and the sleeve 130 are also provided. [0010] The bearing clearances are provided to form a path between the sleeve 130 , the outer circumferential surface of the shaft 150 , the thrust plate 151 , and the thrust flange 153 . [0011] An oil inlet 160 is provided at one side of the sleeve 130 through the outer circumferential surface to the inner circumferential surface thereof. The oil inlet 160 is also provided at the base 110 adjacent to the side of the flange 153 . Oil, provided through the oil inlet 160 , is filled into the bearing clearances to support the shaft 150 , with the pressure generated by the grooves, when the shaft 150 is rotated. [0012] In the conventional hard disc drive spindle motor, having a structure as described above, as the shaft is rotated, the oil is subject to heat generated by friction. As temperature increases, due to frictional heat generated in the bearing clearances, the air bubbles in the oil, provided into the bearing clearances, are thermally expanded. Consequently, a problem occurs in that non-repeatable run-out (NRRO) critical to driving characteristics, driving resistances, and consumption power increases. Therefore, a separate vent is formed, or the oil inlet as shown in FIG. 1, is used to eliminate the air bubbles from the bearing clearances. [0013] [0013]FIG. 2 shows a state in which the oil flows out from the conventional spindle motor shown in FIG. 1. Referring to FIG. 2, as the air bubbles flow out through the oil inlet 160 , the oil also flows out from the bearing clearances. The oil, that has flowed out, contaminates the inside of the spindle motor. Further, as the oil has flowed out, a deficiency of oil in the bearing clearances occurs. Accordingly, abrasion of frictional members is accelerated and their life cycles are reduced, or in a severe case, the spindle motor cannot be driven. [0014] In addition, fine metal particles, produced during the assembly of the frictional members, can be mixed with the oil in the bearing clearances. The metal particles can cause damage to the frictional surface of the shaft, or obstruct the driving of the motor as they flow out with the oil. SUMMARY OF THE INVENTION [0015] The present invention provides a spindle motor for a hard disc drive including an oil outflow prevention apparatus preventing an outflow of oil, but allowing an outflow of air bubbles, from bearing clearances, when a shaft is rotated. [0016] A hard disc drive, spindle motor, according to an aspect of the present invention includes a base, a thrust plate mounted on the base forming bearing clearances with respect to a shaft, and supporting the shaft in the thrust direction, a sleeve accommodating the shaft forming bearing clearances between the inner circumferential surface of the sleeve and the outer circumferential surface of the shaft, and supporting the shaft in the radial direction when the shaft is rotated. The motor also includes a starter core mounted at the outer side of the sleeve, and a hub to which the shaft is fixed, having an assembly of a yoke and a magnet provided at a position corresponding the starter core to produce electromagnetic forces through interactions with the starter core. An oil inlet is at one side of the sleeve through the outer circumferential surface to the inner circumferential surface of the sleeve, and through which oil is provided into the bearing clearances. An oil outflow prevention apparatus is mounted at an inner side of the oil inlet preventing the oil from flowing out through the oil inlet, but allowing outflow of air bubbles, generated due to gasification of the oil, while the shaft is rotated. [0017] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0018] These and/or other aspects and advantages of the invention will become apparent, and more readily appreciated, from the following description of the embodiments taken in conjunction with the accompanying drawings in which: [0019] [0019]FIG. 1 is a side cross-sectional view of a conventional hard disc drive spindle motor; [0020] [0020]FIG. 2 shows a state in which oil has flowed out from the conventional spindle motor shown in FIG. 1; [0021] [0021]FIG. 3 is a side, cross-sectional view of a hard disc drive, spindle motor having an oil outflow prevention apparatus according to an aspect of the present invention; [0022] [0022]FIG. 4 is an exploded perspective view of an oil outflow prevention apparatus according to an aspect of the present invention; [0023] [0023]FIG. 5 is a cross-sectional view of the oil outflow prevention apparatus taken along line V-V′ in FIG. 4; and [0024] [0024]FIG. 6 is an exploded perspective view of an oil outflow prevention apparatus according to another preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0025] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. [0026] Referring to FIG. 3, a hard disc drive, spindle motor 200 , according to an aspect of the present invention, includes a base 210 , a hub 270 , and a shaft 250 . The shaft 250 is rigidly fixed to the hub 270 , and rotated in accordance with the rotation of the hub 270 . A thrust plate 251 is mounted on the base 210 , and a thrust flange 253 is mounted on the thrust plate 251 . The thrust flange 253 is rigidly fixed into the lower side of the shaft 250 . [0027] A sleeve 230 is mounted above the thrust plate 251 and the thrust flange 253 , and the shaft 250 is inserted into, and can be rotated in, the inner circumferential section of the sleeve 230 . Bearing clearances are provided at the sections where the sleeve 230 , the shaft 250 , the thrust plate 251 , and the thrust flange 253 contact each other. [0028] Although not shown in FIG. 3, grooves are provided for generating dynamic pressure, e.g., in a spiral pattern, at a surface where the thrust plate 251 and the thrust flange 253 contact each other, and at a surface where the thrust flange 253 and the sleeve 230 contact each other. The grooves generate dynamic pressure, while the shaft is rotated, so that oil fills into the bearing clearances to support the shaft 250 in the axial direction. [0029] Grooves 231 are also provided, for generating a dynamic pressure, at the upper and the lower sides of the inner circumferential section of the sleeve 230 . While the shaft 250 is rotated, the grooves 231 generate dynamic pressure so that oil fills into the bearing clearances to support the shaft 250 in the radial direction. [0030] The thrust plate 251 , the thrust flange 253 and the sleeve 230 , and the shaft 250 and the sleeve 230 , form fluid dynamic bearings, and the grooves 231 generate dynamic pressure when the shaft 250 is rotated so that oil fills into the bearing clearances to support the shaft 250 in the radial direction. [0031] A starter core 211 is mounted on the base 210 , and at the outer side of the sleeve 230 , and an assembly of a yoke 271 and a magnet 272 is provided at a position corresponding to the starter core 211 to produce electromagnetic forces through interaction with the starter core 211 . [0032] The starter core 211 and the assembly of the yoke 271 and the magnet 272 interact with each other, and produce electromagnetic forces. As the electromagnetic forces rotate the hub 270 , the shaft 250 , fixed to the hub 270 , is also rotated. [0033] An oil inlet 260 is at one side of the sleeve 230 through the outer circumferential surface to the inner circumferential surface of the sleeve 230 . Another oil inlet 260 is also provided at the other side of the sleeve 230 facing the side surface of the thrust flange 253 . Therefore, the bearing clearances are able to be filled with oil, provided from outside, through the oil inlets 260 . [0034] An oil outflow prevention apparatus 290 is installed in the oil inlets 260 . Referring to FIGS. 4 and 5, the oil outflow prevention apparatus 290 includes a locking member 291 , a filtering member 294 , and a fixing member 297 . [0035] The locking member 291 has a cylindrical shape, and a circular opening 293 is formed at the center of the locking member 291 . A flange 293 a is provided between the outer circumference of the opening 293 and the outer circumference of the locking member 291 . A plurality of locking holes 292 are located in the flange 293 a at predetermined intervals along the circumferential direction thereof. The locking holes 292 are cone-shaped, having tapers in the direction where the filtering member 294 and the fixing member 297 are engageable. [0036] The filtering member 294 has a cylindrical shape, and a circular opening 296 is at the center of the filtering member 294 . A flange 296 a is provided between the outer circumference of the opening 296 and the outer circumference of the filtering member 294 . A plurality of perforations 295 are located in the flange 296 a at predetermined intervals along the circumferential direction thereof. According to an aspect of the invention, a membrane is mounted at the opening 296 . The membrane passes air bubbles, but not oil. Therefore, during the rotation of the shaft 250 , the outflow of the oil, filled in the bearings of the spindle motor, through the membrane can be prevented, while the air bubbles can flow out through the membrane. [0037] The fixing member 297 has a cylindrical shape, and a circular opening 299 at the center of the fixing member 297 . A flange 299 a is provided between the outer circumference of the opening 299 and the outer circumference of the fixing member 297 . A plurality of protrusions 298 are located on the flange 299 a at predetermined intervals along the circumferential direction thereof. The protrusions 298 are cone-shaped having tapers, and insertable into the locking holes 292 . [0038] When the locking member 291 , the filtering member 294 , and the fixing member 297 are assembled, the protrusions 298 are inserted into the locking holes 292 through the perforations 295 . The oil outflow prevention apparatus 290 assembly as described above is engageable with a projected hooking member 261 formed at the inner side of the oil inlet 260 . While a pair of hooking members 261 , symmetrically formed and placed are shown in FIG. 4, a varied number of hooking members 261 can be formed along the inner circumferential direction. [0039] Referring to FIG. 6, an oil outflow prevention apparatus according to an aspect of the present invention is shown including a membrane 391 , attached at the entrance of the oil inlet 260 using adhesives. For attaching the membrane 391 at the entrance of the oil inlet 260 , adhesives can be applied either to the edge of the membrane 391 or to the border of the entrance, or a double-sided adhesive tape can be used. [0040] It is noted that the oil can be provided, through the oil inlet 260 into the bearing clearances, by making the bearing clearances vacuous with a predetermined device, or tool, and using a pressure difference. Thereafter, the oil outflow prevention apparatus 290 is installed in the oil inlet 260 to prevent outflow of the oil, through the oil inlet 260 , when the shaft 250 is rotated. [0041] As described above, in a hard disc drive, spindle motor according to an aspect of the present invention, the membrane installed in the entrance of the oil inlet can prevent outflow of oil from bearing clearances while allowing the outflow of air bubbles generated when a shaft is rotated, and therefore, the contamination of the spindle motor due to an outflow of oil can be effectively prevented. [0042] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

A spindle motor for a hard disc drive. The spindle motor includes an oil outflow prevention part mounted at an inner side of an oil inlet, preventing oil from flowing out through the oil inlet, but allowing an outflow of air bubbles that are generated due to gasification of the oil. Accordingly, the contamination of the spindle motor due to oil that has flowed out is decreased.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser shock processing operation, and, more particularly, to a method and apparatus for accurately and automatically tracking the position of a workpiece, such as an integrally bladed rotor, by dynamically adjusting the position of the workpiece in order to compensate for the presence of distortion or manufacturing variations. 2. Description of the Related Art Laser shock processing, or laser shock peening, or laser peening, as it is also referred to, is a process for producing a region of deep compressive residual stresses imparted by laser pulses directed onto the surface area of a workpiece. Laser shock processing is an effective method of increasing fatigue resistance in metals by treating fatigue critical regions. For a more thorough background in the prior history of laser shock processing, a reference can be made to U.S. Pat. Nos. 5,131,957 and 5,741,559, such patents are explicitly hereby incorporated by reference. Laser shock processing, as understood in the art and used herein, means utilizing a laser beam from a laser beam source to produce a strong localized compressive force on a portion of a workpiece by producing an explosive force by instantaneous ablation or vaporization of a painted, coated, or un-coated surface. Laser peening has been utilized to create a compressively stressed layer in the subsurface of a workpiece, thereby considerably increasing the resistance of the workpiece to fatigue failure. Laser shock processing typically utilizes two overlays: a transparent overlay (usually water) and an opaque overlay, typically an oil-based, acrylic-based, or water-based paint or tape. Laser shock processing can also utilize only a transparent overlay or bare surface. During processing, a laser beam is directed to pass through the transparent overlay and is absorbed by the opaque overlay or bare surface, causing vaporization of a portion of the opaque overlay or bare surface, which results in rapid plasma formation and the generation of a high amplitude shock wave. The shock wave cold works the surface of the workpiece and creates compressive residual stresses, which provide an increase in fatigue properties of the part. A workpiece may be processed by producing a matrix of overlapping spots that cover the fatigue-critical zone of the part. Laser shock processing is being used for many applications within gas turbine engines, such as leading and trailing edges of fan and compressor airfoils. These laser peening applications, as well as others, are in need of improved positioning techniques to reduce setup time and improve the quality and consistency of the processed part. The quality of laser peening depends, in part, upon the accurate and repeatable positioning of the laser beam on the part. Current laser-beam-positioning methods for laser peening parts are accomplished by moving the workpiece to a definite, hard-coded position in space and then firing the laser. The index of this point in space for purposes of identifying the target area can be any convenient feature of the workpiece or part manipulator (reference point), e.g. a corner of the platform of an airfoil, not the coordinates of the point where the laser hits the part, i.e., target area. Consequently, as the reference point of the part (or subsequent similar parts) is moved to the same location, small deformations, distortion, and variations within dimensional tolerances in each individual part (specifically, at or near the target area) will change the exact point where the laser hits the part. When laser peening thin sections, such gas turbine engine blades, it is usually desirable to use two-sided processing methods and maintain the symmetry of the shockwaves in order to most efficiently and effectively laser peen the part. Typically, matching the shockwaves generated on opposite sides of a thin section is accomplished by maintaining a substantially identical laser spot size and shape on opposite sides of the part for each laser pulse within the spot pattern being processed. If the angles at which the laser beams are presented to the part are maintained as congruent, and the reference point for the part (which can be many inches away from the target area where processing is to occur) is held as constant, small deformations due to previous processing or dissimilarities between parts can cause the laser to hit the part in an asymmetric manner causing improper processing. Because of the compressive residual stresses imparted by laser peening, small distortions in the part can occur, especially in thin airfoils. Under circumstances where a first series of laser-peened spots causes a slight deformation in the part, the application of a second series of spots over substantially the same target area may result in the beams no longer being disposed substantially opposite one another, depending upon the amount of distortion and the angle on incidence of the laser beams. If the part-positioning program is hard-coded, the operator may never be aware that subsequent series of laser-peened spots were misaligned. These types of in-process misalignment problems can lead to significant variation in the quality and performance of the laser-peened parts, without the operator even realizing the source of the variability. SUMMARY OF THE INVENTION According to the present invention there is provided a method for processing a workpiece whereby the laser peening system (or associated hardware or software) automatically detects, and then automatically compensates for, deviations from the ideal positioning of a part. If all parts were identical, the part manipulator could be preprogrammed for the ideal part and each part would then be processed identically, using the same program. However, deviations from the ideal part occur. By way of background, such deviations or departures from an ideal construction may stem from normal manufacturing tolerances, tolerance or repeatability problems associated with the part fixture that holds the part in the manipulator, distortions caused by earlier laser peening steps on the part, or any other effect that would cause the part to not be positioned in an ideal or pre-determined location relative the laser beam. Dissimilarities can exist between the workpiece being processed and the template or test workpiece that was used to derive the part processing program. Due to a lack of exact reproducibility in the manufacturing process, the same manufacturing operation can produce a series of workpieces of the same type that have dimensional variations relative to the ideal workpiece, yet still be within manufacturing tolerances. The problem that arises relates to the fact that the part program for controlling the positional movements of the workpieces during laser shock processing is based upon the ideal part construction or a test part that was used during programming; accordingly, any dimensional or structural deviations can result in the laser beam impinging upon the production workpiece in a manner or place different from that contemplated in regard to the ideal workpiece. Another issue that adversely affects the reliability and repeatability of laser peening arises from the fixturing of the part within the part manipulator. Slight misalignments that may occur during mounting of the part, which may be caused by normal tolerance problems or human errors, can lead to significant misalignment of the laser beam on the part. Still another issue that adversely affects the reliability and repeatability of laser peening relates to distortion effects that can arise during laser peening because of the compressive residual stresses imparted by the process. Consequently, it is possible that the alignment for subsequent laser peening sequences on a part may be adversely affected by preceding laser-peening sequences. Even if the distortion of the part remains within manufacturing tolerances, the subsequent laser-peening sequences may be ineffectual or even deleterious, if processing continues after a misalignment has occurred. In view of the foregoing, there is proposed herein a method and apparatus that overcome the disadvantages found in conventional laser shock processing operations. The processing method of the present invention involves providing a conventional part program that defines a sequence of fixed processing positions, i.e. a preprogrammed spot pattern. At the outset of the processing operation, the workpiece is moved to an initial or first processing position in the part program sequence. Measurements are taken to collect and otherwise acquire workpiece data that defines a spatial parameter characterizing a current target area of the workpiece. In one form, the spatial parameter represents the distance between the current target area and a reference point such as the base which supports the workpiece. Alternatively, the spatial parameter can define a target area profile which provides a geometric representation of the current workpiece target area. In all cases, the spatial parameter facilitates a comparison between the actual position of the current target area and the ideal position of the same target area as determined in connection with the ideal workpiece construction upon which the part program is based. The collected workpiece data is processed and otherwise analyzed to evaluate the spatial parameter in relation to predetermined criteria. For example, when the spatial parameter represents a distance measurement, the spatial parameter is compared to a reference distance value that was obtained in connection with the ideal workpiece. Based upon this comparison, a difference value can be obtained which represents the variation of the production workpiece measurement from the ideal workpiece measurement. The position of the workpiece is then adjusted in accordance with the evaluation results to enable reliable, repeatable, and reproducible laser shock processing of the workpiece at the current target area. After the laser shock processing operation is performed on the workpiece at the current target area, the workpiece is moved to the next sequential target area of the processing positions and the aforecited processing method is repeated until the part program is completed. The workpiece is typically laser peened by processing a matrix of overlapping or non overlapping laser beam spots that cover a critical zone of interest. Additionally, the same or adjacent areas may be repeatedly processed by cyclically directing the laser pulse to the desired target area. Various parameters may be controlled by the production manager to tailor the laser shock processing operation. For example, among the operational parameters that the designer can select and adjust include (but are not limited to) the location of the incident beam spot, the number of spots at each location, spacing between spots, distance of spots from or to certain workpiece features (e.g., leading and trailing edge of integrally bladed rotor), angle of incidence of the laser beam, and the laser beam metrics (energy, pulse risetime, pulse width, spot shape, etc.). Additional descriptions may be found in U.S. Pat. Nos. 5,741,559 and 5,911,890, both assigned to the same assignee as the present application and incorporated herein by reference thereto. One significant advantage of laser shock processing is its ability to increase the fatigue properties of the part by selectively imparting compressive residual stresses within certain critical areas where incipient weaknesses or cracks typically appear. The technique has been applied with favorable success to the processing of the pressure and suction sides of leading and trailing edges of fan and compressor airfoils and blades in gas turbine engines. As used herein, a workpiece refers to any solid body or other suitable material composition that is capable of being treated by laser shock processing. The workpiece may represent a constituent piece forming part of an in-production assembly, a final production article, or any other desired part. Accordingly, the laser shock processing treatment may be applied at any stage of production, i.e., pre- or post-manufacturing or any intervening time. Preferably, in certain industrial applications, the present invention finds significant use in processing the airfoils of an integrally bladed rotor, most notably in the region proximate the leading and trailing edges where flaws and cyclical fatigue failures pose serious problems affecting the performance and durability of the engine. As used herein, a part program conventionally refers to the sequence of positions where the workpiece is located during each interval or stage of laser shock processing. Typically, the workpiece (or its assembly) is loaded into a part manipulator or other such machine of conventional construction having a control apparatus implemented by a microprocessor. This computing device is preprogrammed with the part program, which contains a predetermined set of instructions representing the various locations where the workpiece is to be positioned and the timing and sequence in which such movements are to take place. The movement of the workpiece is coordinated and otherwise synchronized with the operation of the laser apparatus using a suitable timing and control apparatus or other suitable system management facility. The part program is typically accompanied by or includes a laser operation program that serves to link or otherwise associate the various workpiece processing positions with corresponding laser shock peening activity characterized by parameters including, but not limited to, pulse number and intensity, angle of incidence, laser-beam spot size, laser-beam spot shape, pulse duration, pulse reforming or reshaping, and pulse modulation. As used herein, optimal processing refers generally to any form of laser shock processing that produces a desired outcome or result. This result, for example, may be measured or determined by whether the processed article and/or the spot pattern exhibits, meets, or otherwise satisfies predetermined criteria formulated by the designer. A general aim of such optimization involves the development of shock-induced compressive residual stresses without introducing any distortion into the workpiece. Alternately, this optimization may be considered to involve the elimination or substantial reduction in the possibility of non-uniformly working the material stemming from a non-uniform application of energy to the workpiece. This non-uniformity may be characterized in a number of ways, for example, asymmetrical shock-induced stress regions, mismatched or unbalanced shock wave activity, misalignment of laser beam spots impacting opposing sides of a workpiece, and misshaped/mismatched laser beam spots incident on opposite sides of the workpiece. In a preferred form, the optimal processing is characterized by the application of a first laser beam spot to one side of the workpiece and the application of a second laser beam spot to another side of the workpiece, wherein (i) the energy density of the first laser beam spot is substantially equal to the energy density of the second laser beam spot, (ii) the respective sizes and shapes (i.e., areas) of the first laser beam spot and second laser beam spot are substantially equal to one another, and (iii) the respective impact areas represented by the first laser beam spot and second laser beam spot are disposed substantially opposite one another. The same conditions apply when a pattern of spots is desired. Attaining these conditions results in optimal laser shock processing of the workpiece. However, in view of the fact that the specific selection of laser peening parameters (e.g., spacing between spots, angle of incidence, distance of spots to certain edges) is made in relation to an ideal workpiece that may vary in its construction (i.e., dimensions and geometrical features) from the actual workpiece (namely at the current target area of interest), the ability of the laser shock processing treatment to maintain substantially constant energy densities at opposing sides of the workpiece is compromised due to the potential dissimilarities between the actual and ideal workpieces. Additionally, any fixturing misalignments and part distortion introduced during laser shock processing will also contribute to the difficulty in maintaining proper energy density levels. Accordingly, even though the workpiece may be moved during processing to precisely track the sequence of positions defined by the part program, the spatial relationship between the intended target areas and the laser beam path is being adversely modified due to the presence of distortions, surface geometry irregularities, and other dissimilarities and variations between the actual and ideal workpieces. As will be discussed herein, the present invention enables the detection of such dissimilarities and distortions in the actual workpiece and provides a position control mechanism that repositions the workpiece such that the current target area is maneuvered into an adjusted position that substantially matches the ideal target area position, thereby reestablishing the original spatial relationship between the laser beam and target area upon which the original part program was developed. As used herein, a spatial parameter refers to any characteristic of the workpiece that is suitable for, or capable of, measuring or otherwise determining any variations between the position, geometry, or other spatial feature of any selected area of the workpiece (e.g., intended laser peening target area) and a reference position, geometry, or other spatial feature, such as the relevant characteristics which pertain to an ideal workpiece. The spatial parameter must be such as to afford the possibility of enabling the workpiece to be repositioned such that the target area can be accordingly displaced into an adjusted position substantially matching the ideal position defined by the reference data. For example, the spatial parameter for the actual workpiece can be the measured distance between a feature of the actual workpiece and expected position of the same feature of the actual workpiece, i.e. where the part would be positioned if it were an ideal workpiece. More directly stated, a measurement is made that represents the spatial orientation of the part and the spatial parameter associated with the measured spatial orientation of the actual workpiece is compared to where the actual workpiece is supposed to be. Where the workpiece is “supposed to be” can be determined by empirical measurement of a representative workpiece, but, preferably, is determined through the design of the target area locations on the ideal part. Because the coordinates of the target areas are fixed for a part prior to laser peening and the path of the laser beam is fixed in space, all that is needed is to know where the actual part is positioned with respect to the coordinates of the target areas. The invention, in one form thereof, is directed to a method of processing a workpiece. According to the method, a workpiece is positioned at a current processing position. Position data is generated that defines at least one spatial parameter that characterizes a positional arrangement of a current target area of the workpiece, wherein the current target area is associated with the current processing position. The position data is processed to evaluate the spatial parameter in relation to predetermined criteria. The position of the workpiece is adjusted in accordance with the evaluation results. Laser shock processing is then performed on the workpiece at the current target area following the position adjustment step. In a preferred form, the steps of the workpiece processing method are repeated for each respective position of a predetermined sequence of positions, such as those of a fixed part program. The spatial parameter, according to one form thereof, defines a target distance measurement representing the distance between the current target area of the workpiece and a reference point. This target distance measurement is then compared to a predetermined distance value, with the comparison result being used to adjust the position of the workpiece. Similarly, one or more spatial parameters could define the measured position and orientation of a feature of the workpiece, representing the changes in the position and orientation (distances and angles) between the current location and orientation of the feature and the reference values for the feature. The position and orientation measurements are then compared to predetermined position and orientation values, with the comparison result being used to adjust the position of the workpiece. The workpiece preferably corresponds to an integrally bladed rotor or other gas turbine engine component. More specifically, the current target area of the workpiece preferably includes at least one of a leading edge section and a trailing edge section of an airfoil in the integrally bladed rotor. The data processing step, according to one form thereof, further includes evaluating the spatial parameter to calculate a possible shift in the position of the workpiece from the current processing position which would be sufficient to enable optimal laser shock processing of the workpiece at the current target area. This optimal laser shock processing, according to a preferred form thereof for two-sided processing, involves applying a first energy signal having an energy density to a first impact area of the workpiece and applying a second energy signal having an energy density substantially equal to the energy density of the first energy signal to a second impact area of the workpiece, wherein the first impact area and the second impact area are substantially equal and are disposed substantially opposite to one another. The invention, in another form thereof, is directed to a method of processing a workpiece. According to the method, a part program is provided which defines a plurality of sequential processing positions. The workpiece is positioned at a current one of the sequential processing positions. Position data is provided that defines at least one spatial parameter which characterizes a positional arrangement of a current target area of the workpiece, wherein the current target area is respectively associated with the current processing position. The position data is processed to evaluate the spatial parameter in relation to predetermined criteria. The position of the workpiece is adjusted in accordance with the evaluation results. The workpiece is laser shock processed at the current target area following the position adjustment step. The workpiece is then positioned at a next current one of the sequential processing positions, and the foregoing steps are repeated until the part program is finished. The invention, in another form thereof, is directed to a method of processing a workpiece. According to the method, the workpiece is positioned at a current processing position, wherein the current processing position is associated with a current target area of the workpiece, and the current target area of the workpiece has a target position value associated therewith that represents the position thereof. A difference measurement is generated which indicates the variation of the position of the current target area of the workpiece from a reference target position, using the target position value. The position of the workpiece is adjusted in accordance with the difference measurement so as to enable the position of the current target area, following positional adjustment of the workpiece, to substantially match the reference target position. Laser shock processing of the workpiece is performed at the current target area following the position adjustment step. The invention, in another form thereof, is directed to a method of processing a workpiece. According to the method, a workpiece is positioned at a current processing position. Position data is provided that defines at least one spatial parameter which characterizes a positional arrangement of a current target area of the workpiece, wherein the current target area is associated with the current processing position. The position data is processed to generate position adjustment data based thereon which represents a possible displacement of the workpiece from the current processing position to another position where optimal laser shock processing of the current target area can occur. The position of the workpiece is adjusted in accordance with the generated position adjustment data. The workpiece is then laser shock processed at the current target area following the position adjustment step. The invention, in yet another form thereof, is directed to a method of processing a workpiece. According to the method, the workpiece is positioned at a current processing position. Position data is generated that defines at least one spatial parameter which characterizes a positional arrangement of a current target area of the workpiece, wherein the current target area is associated with the current processing position. The generated position data is compared to predetermined reference data. The position of the workpiece is then adjusted in accordance with the comparison results. Laser shock processing of the workpiece is performed at the current target area following the position adjustment step. The invention, in yet another form thereof, is directed to a method of processing a workpiece. The workpiece is positioned at a current processing position, wherein the current processing position is associated with a current target area of the workpiece. A determination is made of a position adjustment for the workpiece from the current processing position to an adjusted processing position which would be effective in arranging the workpiece so as to enable the current target area of the workpiece to undergo laser shock processing satisfying predetermined criteria. The position of the workpiece is then adjusted in accordance with the position adjustment determination. The workpiece is laser shock processed at the current target area following the position adjustment step. One advantage of the present invention is that the laser shock processing treatment is not subject to the limitations that attend the hard-coded positioning of conventional part programs since dynamic feedback enables the current target area to be dynamically repositioned for optimal processing. Another advantage of the present invention is that the workpiece can be continuously evaluated on a shot-to-shot basis to ensure that each laser firing repetition produces optimal processing of the workpiece or otherwise satisfies a selected performance criteria. A further advantage of the present invention is that the laser shock processing treatment is made more efficient by ensuring that the laser hits the intended target area. A further advantage of the present invention is that the otherwise deleterious effects of distortion and deformation are ameliorated by dynamically repositioning the workpiece in response to the detection of such distortive features, thereby serving to compensate for the presence of the distortion. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a schematic view of a representative workpiece illustrating in exaggerated form a type of distortion for which the method of the present invention provides compensation; FIG. 2 is a flow chart of the method of the present invention; FIG. 3 is a schematic view of an airfoil illustrating properly aligned laser beams on the edge of the airfoil whereby the laser beams impact the airfoil at oblique angles; and FIG. 4 is the airfoil of FIG. 4 illustrating the severe misalignment of the laser beams that can occur with only a small shift in the positioning of the airfoil. Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings and particularly to FIG. 1, there is shown a representative workpiece 10 illustrating in exaggerated view a type of distortion provided in the form of recess 12 for which the present invention provides compensation, as discussed in further detail below. The effect of such distortion is evident in conjunction with illustrative laser beams 14 and 16 that are directed at respective opposing sides 18 and 20 of workpiece 10 to perform a conventional laser shock processing operation. In the absence of any distortion and the accompanying formation of recess 12 , upper laser beam 14 would strike the surface of upper side 18 and form thereon incident spot 22 as shown in relation to the phantom extension 24 of side 18 over recess 12 . At the opposing side of workpiece 10 , the lower laser beam 16 would strike the surface of lower side 20 and form thereon incident spot 26 . As shown, this type of laser shock processing is desirable since the laser beam incident spots 22 and 26 are disposed substantially opposite to one another and have substantially equal areas, enabling the resulting compressive residual stresses induced by each incident spot to be substantially matched. However, once the distortion is introduced in the form of recess 12 , the respective incident spots become misaligned, thereby leading to a mismatch in the compressive residual stress regions. As shown, laser beam 14 will form an incident spot 28 on the lower surface 30 of recess 12 at upper side 18 that is misaligned with the laser beam spot 26 formed at lower side 20 . This misalignment produces an unbalanced and asymmetrical set of compressive residual stress regions that can lead to further distortion in workpiece 10 . Reference is now made to the flowchart illustrated in FIG. 2 for a discussion of the present invention. As conventionally understood, a part program is developed that includes a sequence of fixed, preprogrammed processing positions that represent the series of locations that the workpiece will occupy during each stage of the laser shock processing operation. For this purpose, there is conventionally provided a part manipulator capable of executing the part program and receiving additional positioning instructions. As conventionally understood, the parameters for the laser shock processing operation are tailored to a corresponding workpiece geometry (“ideal workpiece”). Accordingly, the part program is developed based upon the same workpiece geometry. At the outset, the workpiece under production (“actual workpiece”) is loaded into the part handling system and then positioned to the initial ideal processing point as indicated by the part program ( 50 ). Position data is then collected which facilitates determining a measure of the variation in position of the current target area of the actual workpiece from a corresponding target area in the ideal workpiece ( 52 ). For example, referring to FIG. 1, a first distance measurement 42 measures the distance between a reference point 40 and side 18 within the intended target area in relation to an ideal workpiece, i.e., a part having no distortion. This first distance measurement 42 is typically provided as predetermined information or processing criteria and not a real measurement. A second distance measurement 44 measures the distance between reference point 40 and side 18 within the intended target area in relation to the actual workpiece, i.e., the part under production exhibiting the recess-type distortion 12 . The variation between first and second distance measurements 42 and 44 is illustratively represented by positional variance measurement 46 . Reference is now made to FIG. 3, which illustrates the proper alignment of two laser beams on the edge of an airfoil 10 . Laser beams 14 , 16 are incident on opposite sides 18 , 20 of the airfoil 10 . In this example the laser beams are illustrated to impact the surfaces 18 , 20 of the airfoil 10 at oblique angles. Oblique angles may be required because of interference with other features of the workpiece, e.g. adjacent airfoils of an integrally bladed rotor. Reference is now made to FIG. 4, which illustrates a misalignment of two laser beams on the edge of an airfoil 10 in the upward direction 34 . Laser beams 14 , 16 are incident on opposite sides 18 , 20 of the airfoil 10 , but are now misaligned and will not produce optimum laser shock processing effects. In this example, a small positioning error of a fraction of a millimeter, in the upward direction 34 can cause a very significant misalignment of laser beams 14 , 16 on airfoil 10 . The manner of acquiring the position data on the current target area of the actual workpiece can be accomplished with any number of mechanisms known to those skilled in the art. For example, ranging systems may be used that include video imaging apparatus, laser positioning equipment, and/or mechanical gages. Additionally, the reference point 40 used in providing the various target distance measurements may be any suitable point such as a specific location on: the workpiece, the base which supports the workpiece, the part manipulator, the distance measurement device, or the laser apparatus. The collected position data is then processed in order to perform an evaluation in view of predetermined criteria ( 54 ). For example, the first distance measurement 42 is compared to the second distance measurement 44 to arrive at a difference value represented by variance measurement 46 . This variance measurement 46 represents the degree of compensation needed in the spatial arrangement of the actual workpiece in order to enable optimal laser shock processing to be achieved. In particular, this measure of compensation effectively represents the manner and degree to which the actual workpiece needs to be repositioned in order for the current target area to occupy a position commensurate with the ideal position, thereby aligning the target area with its counterpart in the ideal workpiece. Referring to FIG. 1, proper repositioning of the workpiece according to the present invention would enable the laser beam 14 to impact workpiece 10 in the desired location, namely, at illustrative beam spot area 32 disposed substantially opposite beam spot 26 and having substantially the same sizes. In one embodiment, a triangulation method is used to determine the adjusted position of the workpiece. Using this method, several points in space are fixed and others are determined using geometric analysis. For example, the position of the base and measuring device are known, while the distance between the measuring device and actual workpiece is determined using triangulation analysis. It should be apparent, however, that any type of measurement system may be used. The position of the actual workpiece is then adjusted in response to and in accordance with the variance measurement 46 ( 56 ). In particular, the variance measurement 46 is translated into a suitable command that instructs the part manipulator to move the workpiece from its current hard-coded position (defined by the part program) to the adjusted part processing position. At this juncture, the current target area in the as-adjusted workpiece is now ready for optimal laser shock processing. The laser shock processing operation is then carried out in relation to the current target area following repositioning of the workpiece ( 58 ). After the laser shock processing is finished, the workpiece is then moved to its next sequential hard-coded position as indicated by the part program ( 60 ). The method indicated by steps 52 - 60 is repeated for each one of the hard-coded part processing positions until the part program is finished ( 62 ). It should be clear that in less critical applications it may not be necessary to make adjustments between each processing step. For example, some parts may require that a single location (spot) be processed with more than one laser shot. In this case, the part may be positioned and adjusted only once, even though more than one laser peening step is required. As described herein, a methodology has been proposed that permits dynamic feedback in part processing to enable the part to be repositioned for optimum processing. This could be done either on a shot-to-shot basis or as a pre-processing step between processing layers. At a basic level, this method would allow processing of parts to continue without time-consuming reprogramming of part programs between processing layers or individual shots. The predetermined part program is itself not modified; rather, adjustments are made (if necessary) after the workpiece has been moved to its hard-coded processing position. Extrapolation of the method would allow for a generic processing criteria to be used as an input processing parameter to guide the evaluation effort in selecting the desired positional arrangement of the target area, thereby allowing the processing system to dynamically develop the part-processing program. The invention finds particular use in an airfoil (blade) of an integrally bladed rotor (IBR) for a gas turbine engine. Because the blade cannot be laser peened off of the rotor, the entire rotor must be positioned into the peening cell and the laser beams aligned onto each individual airfoil. Because the airfoils are positioned close together, the laser beams must typically impinge the airfoil at an oblique angle. The invention can be used to actively track the edge of an airfoil during laser peening, whether it is during the initial processing sequence or later sequences. The invention may incorporate an operation-specific, pre-processing step that follows the step of moving the workpiece to its hard-coded processing position but precedes the step of repositioning the workpiece in accordance with the target area measurement data. In particular, parameters such as spacing between spots, distance to certain airfoil edges, and angle of incidence may be entered into the part positioning system to move the workpiece using these parameters. It should be noted that more than one reference point could be used for a workpiece. For example, it may be desirable to laser peen a row of spots at a certain distance from a feature of the workpiece. As a specific example, a row of spots may be applied at a fixed distance from the edge of a gas turbine engine blade and the reference point may be the edge of the blade. The reference point would then be different for each spot location along the blade. Note that in this specific example the part program may now be substantially the same for different types of blades, allowing the operator to provide a more generic part program (a row of spots) and a distance from the edge of the blade to process a wide variety of blades. As discussed herein, the adjustment data is collected at the point where the laser is to hit the part, namely, the current target area. Various methods may be used to determine the amount of deviation, departure, or variation from the ideal workpiece position. This information is then used to reposition the actual workpiece so that the laser hits the part in the desired location. While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

A method of producing a workpiece involves positioning the workpiece at a current processing position indicated by a hard-coded part program and then collecting position data which defines the positional arrangement of a current target area of the workpiece. The collected position data is processed by comparing it to reference position information that represents the positional arrangement of the same target area in an ideal workpiece employed in the development of the part program. The position of the workpiece (and hence the target area) is adjusted in accordance with the comparison results. A laser shock processing operation is performed on the workpiece at the current target area following the position adjustment step.

FIELD OF THE INVENTION [0001] The present invention relates to a step unit, which includes a step member adjacent to a vehicle sliding door. BACKGROUND OF THE INVENTION [0002] Conventionally, a step unit is provided on a vehicle main body to be adjacent to a vehicle sliding door thereof. For example, referring to Non-Patent Document 1, a step unit includes a step member (step) and a rail plate member. A lower rail extending in the opening-closing direction of a vehicle sliding door is provided on the lower surface of the step member. The lower rail supports rollers coupled to the sliding door, so that the rollers and the sliding door are guided along the lower rail. Such a step unit has a cutout portion formed in a part of the lower rail. With the rail plate member (sliding door lower rail plate) removed, the cutout portion allows rollers to be supported by the lower rail or to be removed from the lower rail. PRIOR ART DOCUMENT Non-Patent Document Non-Patent Document 1 [0003] Repair Manual for TOYOTA ALPHARD VELLFIRE, volume F, May 2008 (DH-282 through DH-285, DH-246, DH-247 and other pages) SUMMARY OF THE INVENTION [0004] In the above described step unit, the step member and the fastening piece formed by bending the rail plate member each have a fastening hole, and the step member and the rail plate member are assembled together by a bolt passed through the fastening holes. However, to arrange these members of the step unit such that the fastening holes match each other, the rail plate member needs to be held underneath the step member in by touch. This complicates the assembling process. [0005] Further, in the above described step unit, the rail plate member receives a great load from the rollers, and the lower rail has a low rigidity because of its discontinuous structure on the ends of the cutout portion. The rail plate therefore has a complicated shape. That is, a typical rail plate member is formed by welding two metal sheets together, such that one of the sheets protrudes to be flush with the inner surface of the lower rail. A typical rail plate member also has a structure for reinforcing the ends of the cutout portion of the lower rail. The rail plate member has such a complicated structure. [0006] Accordingly, it is an objective of the present invention to provide a step unit that facilitates the assembly and simplifies the shape of a rail plate member. [0007] To achieve the foregoing objective and in accordance with one aspect of the present invention, a step unit including a step member and rail plate is provided. The step member is provided on a vehicle main body to be adjacent to a vehicle sliding door. The step member has, on a lower surface thereof, a pair of lower rails extending in an opening-closing direction of the sliding door. The rail plate member is arranged at a cutout portion, which is formed in a part of one of the lower rails. The rail plate member makes the lower rail continuous in the opening-closing direction. Rollers are coupled to the sliding door and arranged between the pair of lower rails. The rollers, together with the sliding door, are guided by the lower rails in the opening-closing direction. The step member is molded of a plastic material and has an insertion slit and a support extension, the insertion slit extending through the step member in the vertical direction at a position that corresponds to the cutout portion. The support extension extends from an end of the cutout portion of the lower rail to support the rail plate member against load applied to the rail plate member by the rollers. The rail plate member is assembled to the step member by being inserted through the insertion slit from above the step member. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a perspective view from above illustrating a step unit according to one embodiment of the present invention; [0009] FIG. 2 is a perspective view from below illustrating the step unit shown in FIG. 1 ; [0010] FIG. 3 is a partial plan view illustrating the step unit shown in FIG. 1 ; [0011] FIG. 4A is a cross-sectional view taken along line 4 A- 4 A of FIG. 3 ; [0012] FIG. 4B is a cross-sectional view taken along line 4 B- 4 B of FIG. 3 ; [0013] FIG. 5 is an exploded perspective view illustrating the pulley and the structure for supporting the pulley shown in FIG. 2 ; [0014] FIG. 6 is a partial bottom view illustrating the pulley and the structure for supporting the pulley shown in FIG. 2 ; [0015] FIG. 7 is an explanatory exploded perspective view from below illustrating the support extensions and the rail plate member in the step unit shown in FIG. 1 ; [0016] FIG. 8 is a partial bottom view showing the step unit shown in FIG. 1 ; and [0017] FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 8 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0018] One embodiment of the present invention will now be described with reference to FIGS. 1 to 9 . [0019] A vehicle has a step unit 1 shown in FIG. 1 , which is located adjacent to a vehicle sliding door (not shown). [0020] As shown in FIG. 1 , the step unit 1 of the present embodiment is formed mainly by a drive device (motor unit) 2 for opening and closing the sliding door and a substantially plate-like step member (step) 3 . The step unit 1 is fixed to the main body (not shown) of the vehicle. The entire upper surface of the step unit 1 is covered with an unillustrated thin scuff plate (decorative member). The upper surface of the drive device 2 (the lower surface of the thin plate-like scuff plate) is covered with an unillustrated rigid plate (cover). [0021] The step member 3 is formed by molding a plastic material. The step member 3 is located in the passenger compartment at a position adjacent to the sliding door in the closed state, and includes a flat plate portion 4 , on which an occupant places a foot when getting in or out of the vehicle, and an accommodation portion 5 . The accommodation portion 5 is formed continuous to the flat plate portion 4 and is located on a side of the flat plate portion 4 in the opening direction of the sliding door, or rearward of the flat plate portion 4 . A part of the drive device 2 is fixed and accommodated in the accommodation portion 5 . [0022] Specifically, when the step unit 1 is installed in the vehicle, a bottom 5 a of the accommodation portion 5 is located at a lower position than an upper surface 4 a of the flat plate portion 4 as shown in FIGS. 3 , 4 A and 4 B. The height (depth) of the bottom 5 a of the accommodation portion 5 is determined based on the shape of the drive device 2 . That is, as shown in FIGS. 1 and 3 , the drive device 2 of the present embodiment includes a motor 2 a, which is a drive source, an output portion 2 b, which is attached to the motor 2 a and has a gear and an electromagnetic clutch, a control circuit portion 2 c , which is installed in the output portion 2 b. As shown in FIGS. 4A and 4B , the accommodation portion 5 includes a motor accommodating section 5 b, an output portion accommodating section 5 c, and a circuit accommodating section 5 d, which correspond to the motor 2 a, the output portion 2 b, and the control circuit portion 2 c, respectively. The drive device 2 is fixed by screws such that it partly contacts the bottom 5 a of the accommodation portion 5 . That is, a part of the drive device 2 is located lower than the upper surface 4 a of the flat plate portion 4 . More specifically, one third or more of the entire thickness of the drive device 2 in the vertical direction is located below the upper surface 4 a of the flat plate portion 4 . In the example shown in FIG. 4B , substantially half the entire thickness is located below the upper surface 4 a. Also, a peripheral wall 6 is molded integrally with the step member 3 to encompass (almost the entire circumference of) the accommodation portion 5 as shown in FIGS. 1 , 3 , and 4 . The peripheral wall 6 extends to a position above the upper surface 4 a of the flat plate portion 4 . [0023] As shown in FIG. 2 , pulleys 11 , 12 are located on the lower surface of the step member 3 . A loop belt 13 is rotationally supported by the pulleys 11 , 12 and substantially extends in the opening-closing direction of the sliding door. The drive device 2 is configured to cause the belt 13 to rotate. That is, as shown in FIG. 4A , an output shaft 2 d of the output portion 2 b of the drive device 2 extends through a through hole 5 e formed in the bottom 5 a of the accommodation portion 5 and protrudes from the lower surface of the step member 3 . The output shaft 2 d transmits power that is output by the drive device 2 to the belt 13 via a power transmitting portion 14 (see FIG. 2 ), which is provided on the lower surface of the step member 3 , thereby rotating the belt 13 . In the present embodiment, the opening-closing direction of the sliding door substantially corresponds to the front-rear direction of the vehicle. The position of the belt 13 is regulated by the pulleys 11 , 12 , which are located at ends of the step member 3 in the vehicle front-rear direction, and a regulation portion 15 , which is located between the pulleys 11 and 12 and extends from the lower surface of the step member 3 . The regulation portion 15 is molded integrally with the lower surface of the step member 3 . [0024] A pair of non-annular shaft support portions 16 , which serve as a shaft support portion, are molded integrally with the step member 3 . The pulley 11 , which is located at the front end of the step member 3 , is supported by the non-annular shaft support portions 16 as shown in FIGS. 5 and 6 . The non-annular shaft support portions 16 are formed to engage with and rotationally support the pulley 11 . Specifically, the non-annular shaft support portions 16 are separated in the vertical direction, and each have an opening 16 a, which opens in a direction opposite to the direction of the force that is perpendicular to the axis and applied to the pulley 11 by the belt 13 in a taut state (in other words, the openings 16 a open substantially in the forward direction of the vehicle). A shaft 11 a of the pulley 11 is inserted in the non-annular shaft support portions 16 via the openings 16 a. Accordingly, the pulley 11 is fitted to and rotationally supported by the non-annular shaft support portions 16 . The width of the openings 16 a is slightly smaller than the diameter of the shaft 11 a of the pulley 11 . Therefore, the pulley 11 , which is fitted in the non-annular shaft support portions 16 , is supported by the non-annular shaft support portions 16 , so as not to fall off from the openings 16 a unless it receives a force of a certain magnitude. The pulley 12 , which is located at the rear end of the step member 3 , is rotationally supported by the cover of the power transmitting portion 14 as shown in FIG. 2 . [0025] A pair of lower rails 21 , 22 is molded integrally with the lower surface of the step member 3 as shown in FIG. 2 . The lower rails 21 , 22 extend in the opening-closing direction of the vehicle sliding door (substantially, the front-rear direction of the vehicle). In the present embodiment, the lower rails 21 , 22 are curved inward toward the center of the passenger compartment at a front portion. The lower rails 21 , 22 are connected to each other at both ends in the longitudinal direction. As shown in FIGS. 7 and 8 , a cutout portion 21 a is formed in one of the lower rails, that is, in a part of the lower rail 21 . A rail plate member 31 is arranged at the cutout portion 21 a to make the lower rail 21 continuous in the opening-closing direction of the sliding door (substantially, in the front-rear direction of the vehicle). Rollers 32 (see FIG. 8 ) are supported to roll between the lower rails 21 , 22 (including the rail plate member 31 ). The rollers 32 are coupled to the sliding door, for example, via brackets (not shown). Thus, the rollers 32 and the sliding door are guided in the opening-closing direction by the lower rails 21 , 22 . The rollers 32 are coupled to the belt 13 via brackets (not shown), so that, as the belt 13 rotates, the rollers 32 are moved in the opening-closing direction (while being guided by the lower rails 21 , 22 ). [0026] Specifically, as shown in FIGS. 7 to 9 , the step member 3 has an insertion slit 23 extending through the step member 3 in the vertical direction at a position that corresponds to the cutout portion 21 a. Also, the step member 3 has a pair of support extensions 21 b. The support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 to support the rail plate member 31 against the load applied to the rail plate member 31 by the rollers 32 (see FIG. 8 ). As shown in FIG. 8 , the pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 , and toward the outside with respect to the vehicle width direction), and extend toward each other without being connected to each other (so that there is a space therebetween). Also, the support extensions 21 b are thicker than the lower rail 21 in the direction in which the load is applied (the up-side direction as viewed in FIG. 8 ). [0027] The rail plate member 31 is installed by being inserted through the insertion slit 23 from above the step member 3 as shown in FIG. 7 . The rail plate member 31 is formed by processing a metal plate. As shown in FIGS. 1 and 7 , the rail plate member 31 has an angled portion 31 a at the upper edge (the upper edge in a state after being installed). The angled portion 31 a extends in a direction perpendicular to the vertical direction, or into the passenger compartment with respect to the vehicle width direction in the present embodiment. The rail plate member 31 is assembled with the step member 3 by being inserted into the insertion slit 23 such that the lower side of the angled portion 31 a contacts the upper surface of the step member 3 . The rail plate member 31 is fixed to the step member 3 through press-fitting as shown in FIG. 9 . Specifically, the rail plate member 31 has a pair of press-fit portions 31 b on both sides. The press-fit portions 31 b slightly protrude sideways and are spaced from each other in the vertical direction to be pressed against the ends of the cutout portion 21 a of the lower rail 21 . When the rail plate member 31 is inserted through the insertion slit 23 from above the step member 3 , the press-fit portions 31 b are pressed against the ends of the cutout portion 21 a of the lower rail 21 . At this time, the sides of the cutout portion 21 a may be slightly shaven or elastically deformed by the press-fit portions 31 b. [0028] In the above described configuration, the rail plate member 31 can be removed to insert rollers 32 into the space between the lower rails 21 , 22 through the cutout portion 21 a or remove the rollers 32 from the space between the lower rails 21 , 22 . When the drive device 2 is operated, the belt 13 is rotated. Accordingly, the rollers 32 are moved while being guided by the lower rails 21 , 22 , and the sliding door is operated to open or close. The output shaft 2 d of the drive device 2 or the housing of the drive device 2 has an seal ring, which is not shown, so that water is completely or almost completely prevented from entering the interior of the drive device 2 or the bottom 5 a of the accommodation portion 5 through the through hole 5 e formed in the bottom 5 a of the accommodation portion 5 . [0029] The present embodiment has the following advantages. [0030] (1) The step member 3 has an insertion slit 23 extending through the step member 3 in the vertical direction at a position that corresponds to the cutout portion 21 a, which is formed in a part of the lower rail 21 . The rail plate member 31 is installed by being inserted through the insertion slit 23 from above the step member 3 . This configuration facilitates the assembly process. Also, the step member 3 has a pair of support extensions 21 b, which extends from the ends of the cutout portion 21 a of the lower rail 21 to support the rail plate member 31 against the load applied to the rail plate member 31 by the rollers 32 . Accordingly, the rail plate member 31 is prevented from being deformed by the load applied by the rollers 32 . Further, since the support extensions 21 b extend from the ends of the cutout portion 21 a , the rigidity of the ends of the cutout portion 21 a is increased. This eliminates the need for providing, the rail plate member 31 with a structure for reinforcing the ends of the cutout portion 21 a. Therefore, the shape of the rail plate member 31 can be simplified as in the present embodiment, in which the rail plate member 31 is formed by a single plate (metal plate), for example. Further, if a part of a rail plate member is caused to protrude such that it is flush with the inner surface of a lower rail (the surface that contacts rollers) as in the conventional art, the corners of that part will be rounded. Accordingly, steps are likely to be formed between the ends of the cutout portion of the lower rail and the rail plate member. In the present embodiment, the rail plate member 31 does not need to be molded to protrude. Therefore, it is easy to prevent such steps from being formed. This contributes to smooth movement of the rollers 32 and the sliding door. Further, unlike conventional step members that are formed through sheet-metal processing, the step member 3 is formed through molding a plastic material. This allows the step member 3 to have wide variety of shapes. Accordingly, for example, the support extensions 21 b can be easily molded integrally with the step member 3 . [0031] (2) Since the rail plate member 31 is fixed to the step member 3 through press-fitting, fasteners such as bolts and rivets are not necessary. The number of components of the step unit is thus reduced. [0032] (3) Since the rail plate member 31 is press fitted in the insertion slit 23 to be pressed against the ends of the cutout portion 21 a of the lower rail 21 , steps between the ends of the cutout portion 21 a and the rail plate member 31 are further reduced. Therefore, it is possible to directly suppress chattering of the rail plate member 31 in the opening-closing direction of the sliding door, that is, the direction of movement of the rollers 32 . [0033] (4) The angled portion 31 a, which extends in a direction perpendicular to the vertical direction, is provided at the upper end of the rail plate member 31 . The angled portion 31 a reliably prevents the rail plate member 31 from fall off (the insertion slit 23 of) the step member 3 . Also, with the rail plate member 31 assembled with the step member 3 , the rail plate member 31 can be easily detached from the step member 3 by pushing the lower surface of the angled portion 31 a upward, for example, with a jig. [0034] (5) The pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 ) and, extend toward each other. In this case, when arranging the rollers 32 in the space between the lower rails 21 , 22 through the cutout portion 21 a, the support extensions 21 b do not hamper the operation. In addition, since both ends of the rail plate member 31 are supported by the support extensions 21 b, the rigidity of the rail plate member 31 against load applied by the roller 32 is improved compared to a case in which only one end of the rail plate member 31 is supported. Also, the rigidity of the ends of the cutout portion 21 a is increased. In the above described configuration, the rail plate member 31 can be easily pushed upward manually or with a jig by utilizing the space between the support extensions 21 b. The rail plate member 31 thus can be easily removed. [0035] (6) Since the support extensions 21 b are thicker than the lower rail 21 in the direction in which the load is applied (the up-down direction as viewed in FIG. 8 ), the rail plate member 31 can be firmly supported, while achieving the advantage of the item (5). [0036] The above described embodiment may be modified as follows. [0037] In the above described embodiment, the rail plate member 31 is fixed to the step member 3 through press-fitting. However, the rail plate member 31 may be fixed through other configuration. For example, the rail plate member 31 may be fixed to the step member 3 by using fasteners such as bolts or rivets. In this case, for example, the rail plate member 31 may be fixed by the angled portion 31 a and a fastener that is passed through the step member 3 . To prevent the fastener from interfering with the rollers 32 , the angled portion 31 a is preferably fixed such that it extends in a direction away from the pair of lower rails 21 , 22 (toward the outside of the passenger compartment with respect to the vehicle width direction). In the above described embodiment, the rail plate member 31 is press fitted to be pressed against the ends of the cutout portion 21 a of the lower rail 21 . However, the rail plate member 31 may be press fitted to be pressed in the vehicle width direction (up-down direction as viewed in FIG. 8 ). [0038] In the above described embodiment, the angled portion 31 a, which extends in a direction perpendicular to the vertical direction, is provided at the upper end of the rail plate member 31 . However, the present invention is not limited to this, and a rail plate member that does not have the angled portion 31 a may be used. In such a case, for example, the support extensions 21 b of the step member 3 may have a bottom for preventing the rail plate member from falling off (preferably through integral molding). [0039] In the above illustrated embodiment, the pair of support extensions 21 b extend from the ends of the cutout portion 21 a of the lower rail 21 in the direction in which load is applied (upward as viewed in FIG. 8 ), and extend toward each other. However, a support extension 21 b may be formed only at one of the ends of the cutout portion 21 a. [0040] In the above described embodiment, the rail plate member 31 is formed by processing a metal plate. However, the rail plate member 31 may be formed, for example, through molding plastic. [0041] In the above described embodiment, the step unit 1 includes the drive device (motor unit) 2 for opening and closing a vehicle sliding door. However, the step unit 1 does not necessarily include the drive device 2 . That is, a step member that does not include the accommodation portion 5 may be used. In this case, the pulleys 11 , 12 , the belt 13 and the power transmitting portion 14 are not necessary. DESCRIPTION OF THE REFERENCE NUMERALS [0042] 3 . . . Step Member, 21 , 22 . . . Lower Rails, 21 a . . . Cutout Portion, 21 b . . . Support Extensions, 23 . . . Insertion Slit, 31 . . . Rail Plate Member, 31 a . . . Angled Portion, 32 . . . Rollers.

A step unit includes: a step member which is provided with a pair of lower rails extending in an opening and closing direction of a slide door of the vehicle; and a rail plate member which is provided to a cutout formed in a part of either of the lower rails and which continuously connects the lower rails in the opening and closing direction. The step member is molded using a resin material and is provided with an insertion hole which vertically penetrates through the step member at a position corresponding to the cutout; and a support extension section which is extended from a side end of the cutout of the lower rail. The rail plate member is mounted to the step member by being inserted so as to penetrate through the insertion hole from above the step member.

TECHNICAL FIELD [0001] The present invention relates to a heat ray absorbing lamp cover that exhibits excellent transparency and antifogging property to a light source that causes less temperature rise of the cover due to the lamp irradiation, such as an LED light source and a semiconductor laser. BACKGROUND ART [0002] A methacrylic resin known as a thermoplastic resin is used as a raw material for vehicle members, such as a tail lamp cover and a meter panel, etc. because the methacrylic resin exhibits excellent transparency and weather resistance. An aromatic polycarbonate resin is also used as a raw material for vehicle members, such as a head lamp cover, etc. because the aromatic polycarbonate resin is a thermoplastic resin that exhibits excellent transparency, heat resistance and impact resistance. It is known that such tail lamp covers and head lamp covers are covered with an antifogging coat film on a lamp chamber side of a lens so that the inside of the lamp is not fogged (see Patent Literature 1). PRIOR ART LITERATURE Patent Literature [0003] Patent Literature 1: JP 2003-7105 A SUMMARY OF INVENTION Technical Problem [0004] If the antifogging performance can be imparted to a tail lamp cover and a head lamp cover themselves without requiring the lamp covers covered with the antifogging coat, a manufacturing process of the lamp cover can be simplified, and the lamp can also be manufactured at lower cost. For this purpose, a lamp cover without an antifogging coat is desired. In recent years, LED lamps and semiconductor lasers are being used in place of conventional halogen lamps as a light source of the lamp. For example, in an LED lamp, temperature rise of a lamp cover caused by the irradiation of the lamp is suppressed. As a result, dew condensation is likely to occur inside the lamp cover. Therefore, temperature rise of the lamp cover by sunlight (heat ray) is required in order to increase the temperature of the lamp cover using an LED light source, and thus a lamp cover capable of absorbing a heat ray is required. [0005] An object of the present invention is to provide a heat ray absorbing lamp cover that exhibits excellent transparency and antifogging property to a light source that causes less temperature rise of a cover due to lamp irradiation, such as an LED light source and a semiconductor laser. Solution to Problem [0006] The present inventors have studied earnestly to solve the above problem. As a result, the present inventors have found that the above-mentioned object can be achieved by means described below, and finally accomplished the present invention. [0007] That is, the present invention includes the following preferred aspects. [0008] [1] A heat ray absorbing lamp cover having an average visible light transmittance of 75% or more, an average near-infrared light transmittance of 75% or less, and a haze of 3.0% or less. [0009] [2] The heat ray absorbing lamp cover according to above [1], wherein the heat ray absorbing lamp cover is formed of a resin composition comprising an inorganic infrared-ray shielding material in a ratio of 1 to 5000 ppm by mass to 100 parts by mass of a thermoplastic resin. [0010] [3] The heat ray absorbing lamp cover according to above [2], wherein the thermoplastic resin is an acrylic resin and/or an aromatic polycarbonate resin. [0011] [4] The heat ray absorbing lamp cover according to above [2] or [3], wherein the inorganic infrared-ray shielding material is a composite tungsten oxide fine particle represented by a general formula: [0000] M x W y O z [0012] where M represents at least one element selected from the group consisting of H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi and I, [0013] x, y and z are numbers satisfying the following formulas: [0000] 0.01≦x≦1 [0000] 0.001 ≦x/y≦ 1 and [0000] 2.2 ≦z/y≦ 3.0. [0014] [5] The heat ray absorbing lamp cover according to above [4], wherein the composite tungsten oxide fine particle has an average particle diameter of 1 nm to 800 nm. [0015] [6] The heat ray absorbing lamp cover according to above [4] or [5], wherein the M represents at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr and Ba. [0016] [7] The heat ray absorbing lamp cover according to any one of above [4] to [6], wherein the composite tungsten oxide particle is covered with a dispersant. Advantageous Effects of Invention [0017] According to the heat ray absorbing lamp cover of the present invention, it is possible to obtain an effect of exhibiting excellent transparency and antifogging property to a light source that causes less temperature rise of a cover due to lamp irradiation, such as an LED light source and a semiconductor laser. BRIEF DESCRIPTION OF DRAWINGS [0018] FIG. 1 illustrates a method for determining an antifogging property by use of a contact type thermometer in the present specification. DESCRIPTION OF EMBODIMENTS [0019] In an embodiment of the present invention, a heat ray absorbing lamp cover has an average visible light transmittance of 75% or more, an average near-infrared light transmittance of 75% or less, and a haze of 3.0% or less. In the embodiment of the present invention, the heat ray absorbing lamp cover can be formed of a resin composition comprising a thermoplastic resin and an inorganic infrared-ray shielding material. [0020] (Thermoplastic Resin) [0021] The thermoplastic resin as a base material of a thermoplastic resin composition constituting the heat ray absorbing lamp cover according to the present invention is not particularly limited as far as it is a transparent thermoplastic resin having higher light transmittance in the visible light region, and includes, for example, a thermoplastic resin having a haze of 30% or less according to JIS K 7105 and a visible light transmittance of 50% or more according to JIS R 3106 when the thermoplastic resin is formed into a plate-like molded body having a thickness of 2 mm. Specifically, it is selected from thermoplastic resins exemplified by acrylic resins (resins obtained from a monomer component comprising an acrylic acid monomer and/or a methacrylic acid monomer, which can also be expressed as (meth)acrylic resins), aromatic polycarbonate resins, polyether imide resins, polyester resins and the like, polystyrene resins, polyether sulfone resins, fluorine-based resins and polyolefin resins, depending on desired characteristics, and may be a single resin or a mixture of two or more resins. Among them, acrylic resins, especially methacrylic resins are preferable from a viewpoint of transparency and weather resistance. Aromatic polycarbonate resins are preferable from a viewpoint of heat resistance and impact resistance. [0022] (Methacrylic Resin) [0023] The methacrylic resin which can be used as the thermoplastic resin in the present invention is preferably obtained by polymerizing a monomer component comprising methyl methacrylate and acrylic acid ester. A mass ratio of methyl methacrylate, acrylic acid ester and the like can be appropriately selected. The mass ratio is preferably a mass ratio where methyl methacrylate accounts for 85 to 100 parts by mass and a monomer comprising mainly acrylic acid ester accounts for 0 to 15 parts by mass, and more preferably a mass ratio where methyl methacrylate accounts for 90 to 100 parts by mass and a monomer comprising mainly acrylic acid ester accounts for 0 to 10 parts by mass. The heat resistance of the methacrylic resin can be improved by adjusting the amounts of the monomer such as acrylic acid ester to within the above-mentioned range. [0024] Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, and 2-ethylhexyl acrylate. Among them, methyl acrylate and ethyl acrylate are preferable. Only a single acrylic acid ester may be used, or two or more acrylic acid esters may be used. [0025] The method for polymerizing the monomer component is not particularly limited, and for example, a known polymerization method such as suspension polymerization, solution polymerization and mass polymerization can be employed. Among them, mass polymerization is preferable. Any of a batch-wise polymerization and a continuous polymerization can be employed as the mass polymerization. For example, a polymer can be obtained with high productivity by a method of retaining the monomer component, a polymerization initiator and the like in a reaction vessel for a predetermined time while continuously supplying the monomer component, the polymerization initiator and the like into the reaction vessel, and continuously drawing obtained partial polymer. [0026] The polymerization initiator used when polymerizing the monomer component is not particularly limited, and a known radical polymerization initiator, for example, azo compounds such as azobisisobutyronitrile; and peroxides such as 1,1-di(t-butylperoxy)cyclohexane can be used. Only a single polymerization initiator may be used, or two or more polymerization initiators may be used. [0027] When the monomer component is polymerized, a chain transfer agent can be used, if necessary. The chain transfer agent is not particularly limited, and preferable examples thereof include mercaptans such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan and 2-ethylhexyl thioglycolate. Only a single chain transfer agent may be used, or two or more chain transfer agents may be used. [0028] The molecular weight distribution index represented by (weight average molecular weight)/(number average molecular weight) of the methacrylic resin used in the present invention is not particularly limited, and preferably 1.8 to 6.0. In particular, it is difficult to obtain a methacrylic resin having a molecular weight distribution index of 2.2 or more by common radical polymerization. Thus, a known polymerization method such as a method using a plurality of radical polymerization initiators, a method using a plurality of chain transfer agents, a method of combining multiple stages of polymerization processes, etc. is preferably used. [0029] The methacrylic resin having a molecular weight distribution index of 2.2 or more as described above may also be prepared by mixing two or more methacrylic resins having different weight average molecular weights. The method of mixing is not particularly limited, and a melt-kneading method, a solvent kneading method, a dry blending method, etc. is used. From a viewpoint of productivity, the melt-kneading method and the dry blending method are preferably used. A common mixer, kneading machine or the like can be used as an apparatus used for mixing. Specific examples thereof include a single screw kneading extruder, a twin screw kneading extruder, a ribbon blender, a Henschel mixer, a Banbury mixer, and a drum tumbler. [0030] The metacrylic resin used in the present invention may contain various additives such as, for example, an antioxidant, a stabilizer, an ultraviolet absorber, a lubricant, a processing aid, an antistatic agent, a coloring agent, an impact-resistant aid, a foaming agent, a filler and a matting agent, if necessary. [0031] (Aromatic Polycarbonate Resin) [0032] Examples of the aromatic polycarbonate resin which can be used as the thermoplastic resin in the present invention include, for example, a resin obtained by reacting a dihydric phenol and a carbonylation agent by an interfacial polycondensation method, a melt transesterification method, or the like; a resin obtained by polymerizing a carbonate prepolymer by a solid-phase transesterification method or the like; and a resin obtained by polymerizing a cyclic carbonate compound by a ring-opening polymerization method. [0033] Examples of the dihydric phenol include hydroquinone, resorcinol, 4,4′-dihydroxydiphenyl, bis(4-hydroxyphenyl)methane, bis{(4-hydroxy-3,5-dimethyl)phenyl}methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A), 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, 2,2-bis{(4-hydroxy-3,5-dimethyl)phenyl}propane, 2,2-bis{(4-hydroxy-3,5-dibromo)phenyl}propane, 2,2-bis{(3-isopropyl-4-hydroxy)phenyl}propane, 2,2-bis{(4-hydroxy-3-phenyl)phenyl}propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)-3,3-dimethylbutane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 2,2-bis(4-hydroxyphenyl)pentane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)-4-isopropylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis{(4-hydroxy-3-methyl)phenyl}fluorene, α,α′-bis(4-hydroxyphenyl)-o-diisopropylbenzene, α,α′-bis(4-hydroxyphenyl)-m-diisopropylbenzene, α,α′-bis(4-hydroxyphenyl)-p-diisopropylbenzene, 1,3-bis(4-hydroxyphenyl)-5,7-dimethyladamantane, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenylsulfoxide, 4,4′-dihydroxydiphenylsulfide, 4,4′-dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenyl ether, and 4,4′-dihydroxydiphenyl ester. These may be used singly or in combination. [0034] Among these dihydric phenols, bisphenol A, 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)-3-methylbutane, 2,2-bis(4-hydroxyphenyl)-3,3-dimethylbutane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and α,α′-bis(4-hydroxyphenyl)-m-diisopropylbenzene are preferable. In particular, it is preferable to use bisphenol A alone or use bisphenel A in combination with at least one selected from a group consisting of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 2,2-bis{(4-hydroxy-3-methyl)phenyl}propane and α,α′-bis(4-hydroxyphenyl)-m-diisopropylbenzene. [0035] Examples of the carbonylation agent include carbonyl halides (such as phosgene), carbonate esters (such as diphenyl carbonate), and haloformates (such as dihaloformate as dihydric phenol). These may be used alone or in combination. [0036] The aromatic polycarbonate resin may contain an additive such as a release agent, an ultraviolet absorber, a dye, a pigment, a polymerization inhibitor, an antioxidant, a flame retardant, and a reinforcing material as far as the additive does not impair the effect of the present invention. [0037] (Inorganic Infrared-Ray Shielding Material) [0038] The heat ray absorbing lamp cover according to the present invention is preferably formed of a resin composition containing the inorganic infrared-ray shielding material in a ratio of 1 to 5000 ppm by mass to 100 parts by mass of the thermoplastic resin from a viewpoint of an infrared-ray shielding performance and a haze. [0039] An inorganic particle (including a composite tungsten oxide fine particle described later) contained in the inorganic infrared-ray shielding material used in the present invention usually has an average particle diameter of 1 nm to 800 nm, preferably 1 nm to 500 nm, more preferably 1 nm to 300 nm, and furthermore preferably 1 nm to 100 nm. When the average particle diameter is 1 nm or more, an aggregation effect can be suppressed so that dispersion failure can be effectively prevented. When the average particle diameter is 500 nm or less, increasing in haze of a transparent resin molded article can be prevented effectively. In the present invention, the average particle diameter of the inorganic particle means a dispersion particle diameter thereof when the inorganic particle is dispersed. The average particle diameter (dispersion particle diameter) of the inorganic particle can be determined using a variety of commercially available particle size analyzers. For example, it can be determined by use of ESL-800 manufactured by Otsuka Electronics Co., Ltd. which employs a dynamic light scattering method as a principle. Examples of the inorganic infrared-ray shielding material include a tungsten-based inorganic infrared-ray shielding material, a lanthanum-based inorganic infrared-ray shielding material, a tin-based inorganic infrared-ray shielding material, and an antimony-based infrared-ray shielding agent. Among them, the tungsten-based inorganic infrared-ray shielding material is preferable from a viewpoint of infrared-ray shielding performance and haze. Among them, a composite tungsten oxide fine particle is particularly preferable. [0040] (Composite Tungsten Oxide Fine Particle) [0041] The composite tungsten oxide fine particle used in the present invention is preferably a composite tungsten oxide fine particle represented by a general formula: [0000] M x W y O z [0042] where M represents at least one element selected from the group consisting of H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi and I, [0043] x, y and z are numbers satisfying the following formulas: [0000] 0.01≦x≦1 [0000] 0.001≦ x/y≦ 1 and [0000] 2.2≦ z/y≦ 3.0. [0000] Among them, M is preferably at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr and Ba, and most preferably K, Rb or Cs. The range of x is preferably 0.01≦x≦0.5 and more preferably 0.2≦x≦0.4. Furthermore, the ranges of x/y and z/y are preferably 0.01≦x/y≦0.5 and 2.7≦z/y≦3.0, respectively, and more preferably 0.2≦x/y≦0.4 and 2.8≦z/y≦3.0, respectively. [0044] The composite tungsten oxide fine particle can be obtained by subjecting a tungsten compound as a starting raw material to a heat treatment in an inert gas atmosphere or a reducing gas atmosphere. The composite tungsten oxide fine particle obtained through the heat treatment has a sufficient near-infrared-ray shielding power and preferable characteristics as the infrared-ray shielding fine particle. [0045] The starting raw material of the composite tungsten oxide fine particle represented by a general formula M x W y O z is a tungsten compound containing an element M in the form of a simple substance element or a compound. Specifically, it is preferably one or more selected from the group consisting of a tungsten trioxide powder; a tungsten dioxide powder; a tungsten oxide hydrate; a tungsten hexachloride powder; an ammonium tungstate powder; a tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride into an alcohol and then drying it; a tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride into an alcohol, then adding water to form precipitation and drying it; a tungsten compound powder obtained by drying an ammonium tungstate aqueous solution; and metal tungsten powder which contains the element M in the form of a simple substance element or a compound. It is furthermore preferable to use an ammonium tungstate aqueous solution and a tungsten hexachloride solution in light of the fact that each element can easily be mixed uniformly when the starting raw material is a solution. The above-mentioned composite tungsten oxide fine particle can be obtained by use of these raw materials by subjecting them to the heat treatment in an inert gas atmosphere or a reducing gas atmosphere. [0046] In order to produce a tungsten compound as the starting raw material in which individual components are uniformly mixed at a molecular level, it is preferable to mix the individual raw materials in the form of solution, and the tungsten compound containing the element M is preferably capable of being dissolved into a solvent such as water and an organic solvent. Examples of such compounds include, but are not limited to, tungstate, chloride, nitrate, sulfate, oxalate, oxide, carbonate, and hydroxide which contain the element M, and any compound is preferable as long as it can be in the form of a solution. [0047] The above-described raw material for producing the composite tungsten oxide fine particle will be described again in detail below. [0048] As the raw material for obtaining the composite tungsten oxide fine particle represented by the general formula M x W y O z , it is possible to use a powder obtained by mixing a powder of one or more selected from the group consisting of a tungsten trioxide powder, a tungsten dioxide powder, a tungsten oxide hydrate, a tungsten hexachloride powder, an ammonium tungstate powder, a tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride into an alcohol and then drying it or a tungsten oxide hydrate powder obtained by dissolving tungsten hexachloride into an alcohol, then adding water to form precipitation and drying it, a tungsten compound powder obtained by drying an ammonium tungstate aqueous solution and a metal tungsten powder with a powder of the simple substance or compound containing the element M. [0049] Furthermore, when the tungsten compound as the starting raw material for obtaining the composite tungsten oxide fine particle is a solution or a dispersed liquid, each element can easily be mixed uniformly. [0050] From the above-described point of view, the starting raw material of the fine particle of the composite tungsten oxide is furthermore preferably a powder obtained by mixing an alcohol solution of tungsten hexachloride or an ammonium tungstate aqueous solution, with a solution of the compound containing the element M, and then drying them. [0051] Similarly, the starting raw material of the fine particle of the composite tungsten oxide is also preferably a powder obtained by mixing a dispersed liquid obtained by dissolving tungsten hexachloride into an alcohol, then adding water to form a precipitation, with a powder of the simple substance or the compound containing the element M or a solution of the compound containing the element M, and then drying them. [0052] Examples of the compound containing the element M include but are not limited to, tungstate, chloride, nitrate, sulfate, oxalate, oxide, carbonate, and hydroxide of the element M, and any compound is available as long as it can be in the form of a solution. Furthermore, in particular, when the composite tungsten oxide fine particles are industrially produced, a production method using tungsten oxide hydrate powder or tungsten trioxide and carbonate or hydroxide of the element M is preferably employed because the method does not generate a harmful gas or the like in a stage of the heat treatment, etc. [0053] A heat treatment condition of the composite tungsten oxide fine particle in the inert atmosphere is preferably 650° C. or higher. The starting raw material subjected to the heat treatment at 650° C. or higher has a sufficient near-infrared-ray shielding power, and improves efficiency as the infrared-ray shielding fine particle. An inert gas such as Ar and N 2 are preferably used as the inert gas. As a heat treatment condition in the reducing atmosphere, it is preferable to firstly subject the starting raw material to the heat treatment at a temperature of from 100° C. to 850° C. in a reducing gas atmosphere, followed by the heat treatment at a temperature of from 650° C. to 1200° C. in an inert gas atmosphere. The reducing gas in this case is not particularly limited; however, H 2 is preferable. When H 2 is used as the reducing gas, the composition of the reducing atmosphere contains H 2 in a volume ratio of preferably 0.1% or more, and more preferably 2% or more. When the reducing atmosphere contains H 2 in a volume ratio of 0.1% or more, reduction can efficiently proceed. [0054] The surface of the infrared-ray shielding material fine particle obtained by the above-mentioned process is preferably covered with an oxide containing one or more metals selected from the group consisting of Si, Ti, Zr and Al from a viewpoint of improving weather resistance. The covering method is not particularly limited, and the surface of the infrared-ray shielding material fine particle can be covered by adding an alkoxide of the above-mentioned metal into a solution in which the infrared-ray shielding material fine particle is dispersed. [0055] The composite tungsten oxide fine particle is preferably covered with a dispersant. Examples of the dispersant include polymethyl methacrylate, polycarbonate, polysulfone, polyacrylonitrile, polyarylate, polyethylene, polyvinyl chloride, polyvinylidene chloride, fluorine resin, polyvinyl butyral, polyvinyl alcohol, polystyrene, silicone-based resin, and derivatives thereof. Effects of improving dispersibility upon added to the resin and preventing deterioration of the mechanical properties are obtained by the composite tungsten oxide fine particle covered with these dispersants. Examples of the method of covering with the dispersant include a method of dissolving and agitating the composite tungsten oxide fine particle and the dispersant in a solvent such as toluene to prepare a dispersed liquid, and then removing the solvent by a treatment such as vacuum drying to cover the composite tungsten oxide fine particle. [0056] Examples of the method of adding the inorganic infrared-ray shielding material to the thermoplastic resin, especially acrylic resin include a method of directly adding the composite tungsten oxide fine particle or the covered composite tungsten oxide fine particle; and a method of adding it after preliminarily diluted with 1 to 100 times the amount of the thermoplastic resin, especially acrylic resin. [0057] The inorganic infrared-ray shielding material is preferably compounded in the thermoplastic resin used in the present invention for the purpose of imparting heat ray absorbability. The inorganic infrared-ray shielding material used in the present invention is preferably a composite oxide composed of a tungsten oxide component and a cesium tungsten oxide. A preferred upper limit of the ratio of the inorganic infrared-ray shielding material to 100 parts by mass of the resin component is 5000 ppm by mass or less, preferably 3000 ppm by mass or less, and more preferably 2000 ppm by mass or less from a viewpoint of transparency and fine dispersibility. A preferred lower limit of the ratio is 10 ppm by mass or more, preferably 100 ppm by mass or more, and more preferably 20 ppm by mass or more from a viewpoint of heat ray absorbability. [0058] The heat ray absorbing lamp cover according to the present invention has an average visible light transmittance of preferably 75% or more, and more preferably 80% or more. The average visible light transmittance is usually determined as a transmittance in a wavelength region of 380 to 780 nm in a state of a molded body having a thickness of 2 mm. The heat ray absorbing lamp cover according to the present invention has an average near-infrared light transmittance of preferably 75% or less, and more preferably 70% or less. The average near-infrared light transmittance is usually determined as a transmittance in a wavelength region of 800 nm to 2000 nm. The heat ray absorbing lamp cover according to the present invention preferably has excellent transparency and a haze of 3.0% or less. The haze is usually determined for a molded body having a thickness of 2 mm. [0059] The inorganic infrared-ray shielding material reduces the light transmittance in the wavelength region of 800 to 2000 nm. Such shielding ability can also affect higher wavelength region in a visible-range band of less than 800 nm. As a result, the lamp cover looks bluish. In order to suppress this phenomenon, it is effective to adjust color by adding a small amount of a dye to the extent that the average transmittance in the visible-range band of 380 to 780 nm can be maintained at 75% or more. For example, an almost colorless lamp cover can be obtained by adding a red, orange or yellow dye in an amount such that the average light transmittance in the range of 380 to 780 nm is decreased by 1%. [0060] Examples of a red-based dye include color index numbers S.R.143, D.R.191, S.R.146, S.R.145, S.R.150, S.R.149, S.R.135, S.R.179, S.R.151, S.R.52, and S.R.195. Examples of an orange-based dye include a color index number S.O.60. Examples of a yellow-based dye include color index numbers S.G.5, S.Y.16, S.Y.157, S.Y.33, and D.Y.54. [0061] Although the type of the dye is not particularly limited, a dye which does not impair transparency, heat resistance and light resistance of the heat ray absorbing lamp cover is preferable. The added amount of the dye is preferably in a range of 0.1 to 10 parts by mass to 100 parts by mass of the composite infrared-ray shielding material fine particle. The added amount is preferably 10 parts by mass or less because the transmittance is not substantially reduced. The added amount is preferably 0.1 parts by mass or more because it can prevent the color tone from being bluish. [0062] The heat ray absorbing lamp cover according to the present invention is usually obtained by injection molding. For details, the lamp cover according to the present invention can be obtained by use of the above-described thermoplastic resin or thermoplastic resin composition as a molding material and by filling (injecting) it into a mold in a molten state, then cooling the mold, and releasing the molded body from the mold. Specifically, for example, the lamp cover according to the present invention can be prepared by supplying the above-described methacrylic resin composition from a hopper, moving a screw backward while rotating the screw, metering the resin composition in a cylinder, melting the resin composition, filling the molten resin composition into the mold while applying pressure, holding the pressure for a certain time until the mold is sufficiently cooled, and then opening the mold to take out the molded body. Various conditions for preparing the lamp cover according to the present invention (for example, a melting temperature of the molding material, a temperature of the mold upon injecting the molding material into the mold, and a pressure upon holding the pressure after filling the resin composition in the mold) may be set appropriately and are not particularly limited. [0063] Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited thereby. Measurements of various physical properties of obtained resin composition and evaluations thereof were carried out by the following methods. EXAMPLES Example 1 [0064] An inorganic infrared-ray shielding material [“YMDS-874” manufactured by Sumitomo Metal Mining Co., Ltd. (an infrared-ray shielding agent consisting of about 23% by mass of Cs 0.33 WO 3 (average particle diameter: 5 nm) and an organic dispersed resin)] was mixed into a methacrylic resin (“Sumipex MH” manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic resin in a ratio of 1300 ppm by mass (about 300 ppm by mass of Cs 0.33 WO 3 fine particles) (ratio to 100 parts by mass of the thermoplastic resin, the same shall apply hereinafter). Then, the thermoplastic resin was melt-kneaded by use of a single screw extruder (screw diameter: 40 mm) so that the resin temperature might be 250° C., and extruded into a strand, cooled with water and cut with a strand cutter to obtain pellets. Then, a 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of a heat compression molding machine at a molding temperature of 210° C. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 2 [0065] A flat plate was prepared in the same manner as Example 1 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 650 ppm by mass (about 150 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 3 [0066] A flat plate was prepared in the same manner as Example 1 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 330 ppm by mass (about 75 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 4 [0067] A flat plate was prepared in the same manner as Example 1 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 160 ppm by mass (about 37 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Comparative Example 1 [0068] The methacrylic resin (“Sumipex MH” manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic resin was melted and kneaded by use of the single screw extruder (screw diameter: 40 mm) so that the resin temperature might be 250° C., and extruded into a strand, cooled with water and cut with the strand cutter to obtain pellets. Then, a 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of the heat compression molding machine at a molding temperature of 210° C. Example 5 [0069] The inorganic infrared-ray shielding material [“YMDS-874” manufactured by Sumitomo Metal Mining Co., Ltd. (the infrared-ray shielding agent consisting of about 23% by mass of Cs 0.33 WO 3 (average particle diameter: 5 nm) and the organic dispersed resin)] was mixed into an aromatic polycarbonate resin (“Calibre 301-40” manufactured by Sumika Styron Polycarbonate Limited) as the thermoplastic resin in a ratio of 1300 ppm by mass (about 300 ppm by mass of Cs 0.33 WO 3 fine particles) (ratio to 100 parts by mass of the thermoplastic resin, the same shall apply hereinafter). Then, the thermoplastic resin was melted and kneaded by use of a single screw extruder (screw diameter: 20 mm) so that the resin temperature might be 240° C., and extruded into a strand, cooled with water and cut with the strand cutter to obtain pellets. Then, a 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of the heat compression molding machine at a molding temperature of 220° C. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 6 [0070] A flat plate was prepared in the same manner as Example 5 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 650 ppm by mass (about 150 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 7 [0071] A flat plate was prepared in the same manner as Example 5 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 260 ppm by mass (about 60 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 8 [0072] A flat plate was prepared in the same manner as Example 5 except that the inorganic infrared-ray shielding material “YMDS-874” was mixed in a ratio of 130 ppm by mass (about 30 ppm by mass of Cs 0.33 WO 3 fine particles). The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Comparative Example 2 [0073] The aromatic polycarbonate resin (“Calibre 301-40” manufactured by Sumika Styron Polycarbonate Limited) as the thermoplastic resin was melted and kneaded by use of the single screw extruder (screw diameter: 20 mm) so that the resin temperature might be 240° C., and extruded into a strand, cooled with water and cut with the strand cutter to obtain pellets. Then, 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of the heat compression molding machine at a molding temperature of 220° C. Example 9 [0074] An inorganic infrared-ray shielding material [“KHDS-06” manufactured by Sumitomo Metal Mining Co., Ltd. (an infrared-ray shielding agent consisting of about 22% of LaB 6 and an organic dispersed resin)] and an inorganic infrared-ray shielding material [“FMDS-874” manufactured by Sumitomo Metal Mining Co., Ltd. (an infrared-ray shielding agent consisting of about 25% of ATO (antimony-doped tin oxide) and an organic dispersed resin)] were mixed into the methacrylic resin (“Sumipex MH” manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic resin in ratios of 23.5 ppm by mass (about 5.1 ppm by mass of LaB 6 fine particles) and 766 ppm by mass (about 190 ppm by mass of ATO fine particles), respectively (ratios to 100 parts by mass of the thermoplastic resin, the same shall apply hereinafter). Then, the thermoplastic resin was melt-kneaded by use of the single screw extruder (screw diameter: 40 mm) so that the resin temperature might be 250° C., and extruded into a strand, cooled with water and cut with the strand cutter to obtain pellets. Then, a 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of the heat compression molding machine at a molding temperature of 210° C. The inorganic particles (LaB 6 fine particles and ATO fine particles) in the plate had a dispersion particle diameter (average dispersion particle diameter of two kinds of the inorganic particles) of 60 nm. Example 10 [0075] A flat plate was prepared in the same manner as Example 9 except that the inorganic infrared-ray shielding materials “KHDS-06” and “FMDS-874” were mixed in ratios of 15.7 ppm by mass (about 3.4 ppm by mass of LaB 6 fine particles) and 516 ppm by mass (about 128 ppm by mass of ATO fine particles), respectively. The inorganic particles (two kinds of the inorganic particles, LaB 6 fine particles and ATO fine particles) in the plate had a dispersion particle diameter (average dispersion particle diameter of two kinds of the inorganic particles) of 60 nm. Example 11 [0076] The inorganic infrared-ray shielding material [“YMDS-874” manufactured by Sumitomo Metal Mining Co., Ltd. (the infrared-ray shielding agent consisting of about 23% by mass of Cs 0.33 WO 3 (average particle diameter: 5 nm) and the organic dispersed resin)] and a red dye [“Sumiplast Red H3G” manufactured by Sumika Chemtex Company, Limited (color index number: S.R.135)] were mixed into the methacrylic resin (“Sumipex MH” manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic resin in ratios of 1300 ppm by mass (about 300 ppm by mass of Cs 0.33 WO 3 fine particles) and 4.4 ppm by mass (ratios to 100 parts by mass of the thermoplastic resin, the same shall apply hereinafter). Then, the thermoplastic resin was melt-kneaded by use of the single screw extruder (screw diameter: 40 mm) so that the resin temperature might be 250° C., and extruded into a strand, cooled with water and cut with the strand cutter to obtain pellets. Then, a 100 mm square flat plate having a thickness of 2 mm was prepared from the pellets by use of the heat compression molding machine at a molding temperature of 210° C. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 12 [0077] A flat plate was prepared in the same manner as Example 11 except that the red dye [“Sumiplast Red H3G” manufactured by Sumika Chemtex Company, Limited (color index number: S.R.135)] was mixed in a ratio of 3.3 ppm by mass. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 13 [0078] A flat plate was prepared in the same manner as Example 11 except that the inorganic infrared-ray shielding material “YMDS-874” and the red dye [“Sumiplast Red H3G” manufactured by Sumika Chemtex Company, Limited (color index number: S.R.135)] were mixed in ratios of 1090 ppm by mass (about 250 ppm by mass of Cs 0.33 WO 3 fine particles) and 3.5 ppm by mass, respectively. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. Example 14 [0079] A flat plate was prepared in the same manner as Example 11 except that the inorganic infrared-ray shielding material “YMDS-874” and the red dye [“Sumiplast Red H3G” manufactured by Sumika Chemtex Company, Limited (color index number: S.R.135)] were mixed in ratios of 870 ppm by mass (about 200 ppm by mass of Cs 0.33 WO 3 fine particles) and 2.9 ppm by mass, respectively. The inorganic particles (composite tungsten oxide fine particles) in the plate had a dispersion particle diameter of 70 nm. [0080] <Average Visible Light Transmittance and Average Near-Infrared Light Transmittance> [0081] The light transmittance of the prepared flat plates at an optical path length of 2 mm was measured by use of a plastic characteristics measurement system (U-4000 type spectrophotometer) manufactured by Hitachi, Ltd. in a wavelength range of 300 nm to 2000 nm at every 5 nm. An average value of the obtained transmittance in a range of 380 nm to 780 nm was defined as “average visible light transmittance.” An average value of the transmittance in a range of 800 nm to 2000 nm was defined as “average near-infrared light transmittance.” An average value of the transmittance in a range of 400 nm to 480 nm was defined as “average blue light transmittance.” “Degree of blueness” was calculated as [“average blue light transmittance”−“average visible light transmittance”]. Higher value of the degree of blueness means stronger blueness. The results are shown in Tables 1 to 4. [0082] <Haze> [0083] The haze of the flat plates with the thickness of 2 mm prepared as described above was determined according to JIS-K7136 by use of HR-100 manufactured by Murakami Color Research Laboratory. [0084] <Evaluation of Antifogging Property> [0085] A 100 mm square flat plate with a thickness of 2 mm was prepared by use of the heat compression molding machine at a molding temperature of 210° C. The flat plate (test piece having a thickness t=2 mm) was placed at a distance of 5 cm from a 40 W incandescent light bulb lamp as depicted in FIG. 1 , and the temperature of the flat plate after irradiation for 1 hour was measured with the lamp remaining in a lighted state by use of a contact type thermometer. It can be said that the higher the surface temperature of the plate after irradiation is, the better the antifogging property is. [0000] TABLE 1 Example Example Example Example Comparative 1 2 3 4 Example 1 Average visible light 81 87 89 90 91 transmittance (%) Average near-infrared light 33 57 63 69 78 transmittance (%) Average blue light 83 88 90 91 91 transmittance (%) Degree of blueness (%) 2 1 1 1 0 Haze (%) 2.0 2.1 1.5 1.4 1.1 Thermoplastic resin 100 100 100 100 100 [SUMIPEX ®MH] (part by mass) Inorganic infrared-ray 1300 650 330 160 0 shielding material [YMDS-874] (ppm by mass) Amount of Cs 0.33 WO 3 300 150 75 37 0 fine particle (ppm by mass) Average particle diameter 70 70 70 70 — of composite tungsten oxide fine particle (nm) Evaluation Surface temperature 23 23 23 23 23 of before irradiation antifogging (° C.) property Surface temperature 61 59 56 53 51 after irradiation for 1 h (° C.) [0000] TABLE 2 Example Example Example Example Comparative 5 6 7 8 Example 2 Average visible light 73 80 87 89 90 transmittance (%) Average near-infrared light 18 35 66 73 81 transmittance (%) Average blue light 78 83 88 89 89 transmittance (%) Degree of blueness (%) 5 3 1 0 −1 Haze (%) 4.0 4.4 3.2 3.5 3.4 Thermoplastic resin 100 100 100 100 100 [Calibre 301-40] (part by mass) Inorganic infrared-ray 1300 650 260 130 0 shielding material [YMDS-874] (ppm by mass) Amount of Cs 0.33 WO 3 300 150 60 30 0 fine particle (ppm by mass) Average particle diameter 70 70 70 70 — of composite tungsten oxide fine particle (nm) Evaluation Surface temperature 25 25 26 25 25 of before irradiation antifogging (° C.) property Surface temperature 63 57 53 52 50 after irradiation for 1 h (° C.) [0000] TABLE 3 Example Example Comparative 9 10 Example 1 Average visible light 85 87 91 transmittance (%) Average near-infrared light 60 66 78 transmittance (%) Average blue light 84 86 91 transmittance (%) Degree of blueness (%) −1 −1 0 Haze (%) 2.4 2.1 1.1 Thermoplastic resin 100 100 100 [SUMIPEX ®MH] (part by mass) Inorganic infrared-ray 23.5 15.7 — shielding material [KHDS-06] (ppm by mass) Amount of LaB 6 fine particle 5.1 3.4 — (ppm by mass) Inorganic infrared-ray 766 516 — shielding material [FMDS-874] (ppm by mass) Amount of ATO fine particle 190 128 — (ppm by mass) Average particle diameter 60 60 — of inorganic particle (nm) Evaluation Surface temperature 23 23 23 of before irradiation antifogging (° C.) property Surface temperature 56 53 51 after irradiation for 1 h (° C.) [0000] TABLE 4 Example Example Example Example Comparative 11 12 13 14 Example 1 Average visible light 82 81 84 85 91 transmittance (%) Average near-infrared light 37 35 44 50 78 transmittance (%) Average blue light 81 81 83 84 91 transmittance (%) Degree of blueness (%) −1 0 −1 −1 0 Haze (%) 2.4 3.1 2.8 2.6 1.1 Thermoplastic resin 100 100 100 100 100 [SUMIPEX ® MH] (part by mass) Inorganic infrared-ray 1300 1300 1090 870 0 shielding material [YMDS-874] (ppm by mass) Amount of Cs 0.33 WO 3 300 300 250 200 0 fine particle (ppm by mass) Red dye 4.4 3.3 3.5 2.9 0 [Sumiplast ®Red H3G] (ppm by mass) Average particle diameter 70 70 70 70 — of composite tungsten oxide fine particle (nm) Evaluation Surface temperature 23 23 23 23 23 of before irradiation antifogging (° C ) property Surface temperature 60 61 57 56 51 after irradiation for 1 h (° C.) INDUSTRIAL APPLICABILITY [0086] The heat ray absorbing lamp cover according to the present invention can be used as a cover for covering any light source. In particular, it can be suitably used as a cover for a light source causing less temperature rise of the cover due to lamp irradiation. [0087] The present application claims priority to Japanese Patent Application No. 2014-263267 filed on Dec. 25, 2014. The contents of that application are incorporated herein by the reference thereto in their entirety.

There is provided a heat ray absorbing lamp cover that exhibits excellent transparency and antifogging property to light sources that causes less temperature rise of a cover due to lamp irradiation, such as an LED light source and a semiconductor laser. The heat ray absorbing lamp cover has an average visible light transmittance of 75% or more, an average near-infrared light transmittance of 75% or less, and a haze of 3.0% or less.

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of provisional application No. 60/310,581, filed Aug. 7, 2001, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION This invention pertains generally to the field of processing of digital images and particularly to color calibration in digital images. BACKGROUND OF THE INVENTION Digital image data containing color information is produced by various imaging systems, including video cameras, digital still cameras, document scanners and so forth. Calibration of the color data obtained from the imaging system may be required to ensure that the image that is displayed on a display device or printed in hard copy conforms to what would be seen when a human observer views the original object. Such calibration is particularly important for high quality digital camera images. Color calibrated digital cameras allow the professional photographer to be assured that his or her images are calibrated from the time of taking the picture to the final press run. Commercial programs currently exist for color calibration of computer monitors and hardcopy output devices, but there are limited choices for calibrating digital cameras for arbitrary imaging. As will be shown below, the red, green, and blue (RGB) values a digital camera outputs are a function of the surface reflectance of the object, the spectral response of the camera, and the illumination incident on the object being imaged. Ignoring the impact of differing illuminants has been shown to increase error in the calibration. See M. Corbalan, et al., “Color Measurement in Standard Cielab Coordinates Using a 3CCD Camera: Correction for the Influence of the Light Source,” Optical Engineering, Vol. 39, No. 6, 2000, p. 1470-1476; W. W. Brown, et al., “Colorimetry Using a Standard Digital Camera,” Proc. MMS CC&D, 2001. There are a number of ways to account for the spectrum of illumination with which images were taken . If the equipment and time are available, the illumination can be measured directly, which is the most satisfactory method, although the equipment required to measure the illuminant typically costs over $20,000. If measured values of the illuminant are not available, an illuminant can be assumed and the calibration can be performed in the same fashion as if the illuminant were measured. However, the assumed illuminant commonly will not accurately correspond to the actual illuminant, leading to incorrect colors in the final output image. The following provides a brief introduction to color science and the measurement of color to facilitate an understanding of the invention. The standard methods and formulae laid out by the Commission Internationale de I'Eclairage (CIE) will be followed and used herein. The amounts of red, green, and blue needed to form a particular color are referred to as the tristimulus values, X, Y, and Z. The tristimulus values X, Y, and Z of an object are calculated as follows: X=KƒS (λ) R (λ) x 10 (λ) dλ Y=KƒS (λ) R (λ) y 10 (λ) dλ   (1) Z=KƒS (λ) R (λ) z 10 (λ) dλ where S(λ) is the relative spectral power density (SPD) of the illuminant and R(λ) is the reflectance of the surface. The color matching functions corresponding to the 1964 CIE 10° standard observer, x 10 , y 10 , and z 10 are shown graphically in FIG. 1 . A two-dimensional map is obtained by normalizing the magnitudes of the tristimulus values using a ratio of the X, Y, and Z values and the sum of the three values; these ratios are called the chromaticity values, x, y, and z, and are given by: x=X /( X+Y+Z ) y=Y /( X+Y+Z )  (2) z=Z /( X+Y+Z ) The chromaticity chart corresponding to the CIE 1964 10° standard observer is shown in FIG. 2 . The data for both the matching functions and the chromaticity coordinates are from Wyszecki and Stiles, Color Science Concepts and Methods: Quantitative Data and Formulae (book), John Wiley & Sons, New York, 2d Ed., 1982. K is chosen to force the Y value of a white reference object to have a value of 100: Y white =KƒS (λ) R white (λ) y 10 (λ) dλ= 100  (3) where R white (λ) is the reflectance of a standard white object, which would be unity for all λ. Solving Eq. (3) for K and substituting R white (λ)=1, K is found as: K= 100 /ƒS (λ) y 10 (λ) dλ   (4) In practical application, only discrete values of the functions can be measured, so the integrals are approximated by summations and the resulting equations are: X=KΣR (λ) S (λ) x (λ)Δλ Y=KΣR (λ) S (λ) y (λ)Δλ  (5) Z=KΣR (λ) S (λ) z (λ)Δλ where K= 100 /ΣS (λ) y (λ)Δλ  (6) Once K is calculated, the X and Z values of the white point X n , and Z n , can be calculated with the following equations: X n =KΣS (λ) x (λ)Δλ Z n =KΣS (λ) z (λ)Δλ  (7) To quantify color differences between standards and measured values, and to develop a standard cost function, a transformation needs to be made from XYZ coordinate space, as shown in Eq. (2), to a device independent color space. Using the CIE 1976 color space denoted by L*, a*, and b*, these transformations are: L * = 116 ⁢ Y Y n 3 - 16 , Y Y n > 0.008856 a * = 500 ⁡ [ X X n 3 - Y Y n 3 ] , X X n > 0.008856 b * = 200 ⁡ [ Y Y n 3 - Z Z n 3 ] , Z Z n > 0.008856 ( 8 ) To quantify color differences the CIE 1976 color difference equation, denoted by ΔE* ab , may be utilized as follows: Δ E* ab =[(Δ L *) 2 +(Δ a *) 2 +(Δ b * ) 2 ] ½   (9) where ΔL* is the difference in L* values between the standard and measured values, and Δa* and Δb* are similarly differences between standard and measured values. For purposes of calibrating a digital camera such as a CCD (charge coupled device) camera, three linear signals, R camera , G camera , and B camera , can be obtained from the illuminant and the reflectance of the object. See, D. Sheffer, “Measurement and Processing of Signatures in the Visible Range Using a Calibrated Video Camera and the Camdet Software Package,” Proc. SPIE, Vol. 3062, 1997, pp. 243-253. These signals are given by: R camera =K r ƒS (λ) R (λ) r (λ) dλ, G camera =K g ƒS (λ) R (λ) g (λ) dλ,   (10) B camera =K b ƒS (λ) R (λ) b (λ) dλ, where r(λ), g(λ), and b(λ) are the spectral response curves of the sensor in the camera and K r , K g , and K b are the gains set by the white balance process. The white balance process adjusts the K values until the output signals from the CCD, R* camera , G* camera , and B* camera , are equal when imaging a white reference object. The camera output signals are nonlinear and can be represented as: R* camera =( R camera ) γr +β r , G* camera =( G camera ) γg +β g ,  (11) B* camera =( B camera ) γb +β b , where γr, γg, and γb are the gamma correction factors. Since both XYZ and R camera , G camera , and B camera are linear transformations of S(λ), we can write the following matrix equation: ( X / X n Y / Y n Z / Z n ) = T ⁡ ( R camera G camera B camera ) ( 12 ) where T is a transformation matrix. With measured values of R camera , G camera , and B camera and the corresponding XYZ coordinates for standard colors, determining T is simply a matter of finding the optimal solution to Eq. (12). The only obstacle left to overcome is that the camera's output signals R* camera , G* camera , and B* camera and the outputs defined in Eq. (10) are nonlinear functions of one another, implying we need a transformation between the two sets of outputs prior to finding the transformation matrix T given in Eq. (12). A relationship similar to Eq. (11) can be written for R* camera , for example, in terms of ρ r , the apparent average reflectance of the red portion of the spectrum for an arbitrary color standard. The equation is given by: R* camera =(α r ρ r ) γr +β r .  (13) The parameters in Eq. (13), α r and γ r , can be determined by measuring R* camera for a given ρ r for a number of standards and then fitting Eq. 13 to the results. The response the camera would have if it were linear is: R camera =α r ρ r .  (14) After the parameters are found we can solve Eq. (11) for R camera given an arbitrary R* camera . The fitting process is carried out in a similar manner for G camera and B camera for the green and blue channels. Once the values of R camera , G camera and B camera have been determined for the standard colors, we need to find the transformation matrix T given by Eq. (12). To find an optimal value of T we need a cost function. Recall that for every standard panel we have the L*a*b* coordinate, and from the trial values of X/X n , Y/Y n , and Z/Z n calculated using Eq. (12) we can find corresponding trial values L*a*b* from Eq. (9). With the trial values of the coordinates and the known L*a*b* values for each of the standard colors we use Eq. (9) to determine the error, ΔE* ab , for each panel and the cost function, C, then is given by: C = ∑ i = 1 N ⁢ Δ ⁢ ⁢ E abi * , ( 15 ) where N is the total number of standard colors used. In cases where the spectral responses of the camera are significantly different from the color-matching functions, the transformation can be expanded to include square and covariance terms of the RGB channels. The expanded transformation is: ( X / X n Y / Y n Z / Z n ) = T full ⁡ ( R camera G camera B camera R camera 2 G camera 2 B camera 2 R camera ⁢ G camera R camera ⁢ G camera G camera ⁢ B camera ) ( 16 ) The transformation matrix, T full , is now a 3×9 matrix. It is apparent from the foregoing discussion that it is necessary to estimate or measure the illuminant incident on the color standards to accurately calibrate a digital camera. The need to measure the illuminant comes from the fact that in Eq. (6), without an estimated illuminant, S(λ), there are three times the number of spectral points in the illuminant unknowns and only three equations for each known color standard. With fewer equations than unknowns, the system is underdetermined. However, as noted above, measuring the illuminant, such as with a separate ambient illuminant sensor, raises the complexity and expense of obtaining calibrated images and is often cost prohibitive. SUMMARY OF THE INVENTION The present invention features a method and apparatus for accurately estimating the spectral power density of an unknown illuminant, which can lead directly to precise calibration of color digital imagery. The method and apparatus for estimating the spectral power density of an unknown illuminant according to the invention includes an imaging system, such as a digital camera, which takes an image of a plurality of known color standards illuminated by an unknown illuminant. The color information contained in the resulting image is used to estimate the spectral power density of the unknown illuminant. The method and apparatus according to the invention provides an accurate estimate of the spectral power density of an unknown illuminant at a substantially lower cost than methods found in the prior art, which use an expensive spectroradiometer to directly measure the spectral power density of the unknown illuminant. Further objects, features, and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 are graphs of color matching functions for 10° standard observer (CIE 1964). FIG. 2 is a graph showing the CIE 1964 10° standard observer chromaticity chart. FIG. 3 is a graph illustrating D 65 illuminant measured and calculated values. FIG. 4 is a flow chart illustrating operations of the computer software for carrying out the optimization method in accordance with the invention. FIG. 5 are graphs showing both the D 50 and D 65 illuminant spectra for comparison purposes. FIG. 6 is a graph showing D 65 illuminant tabulated and estimated values. FIG. 7 is a flow chart illustrating the method for calculation of the illuminant spectrum in accordance with the invention. FIG. 8 is a block diagram for an apparatus in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION A linear model of an illuminant may be formed of fixed basis functions and weighting coefficients to be determined. Specifically, an arbitrary illuminant L(λ) can be approximated by: L ⁡ ( λ ) = ∑ i = 1 n ⁢ α i ⁢ l i ⁡ ( λ ) , ( 17 ) where α i are the coefficients and I i (λ) are the basis functions. A reduction in dimensionality of the illuminant occurs if the number of basis functions, n, required to approximate the illuminant is less than the number of data points in the original illuminant SPD. Slater and Healy, J. Opt. Soc. of America A, Vol. 15, No. 11, 1998, pp. 2913-2920, found that a basis set of seven vectors would estimate outdoor illumination under a wide variety of conditions with a high degree of accuracy. The seven basis functions adequate for estimating visible outdoor illuminants are given in Table 1. Using these basis functions with n=7 in Eq. (17), significantly reduces the dimensionality of the illuminant. The coefficients are not difficult to estimate in matrix form. Eq. (17) can be written as: L (λ)= lα,   (18) with l being a matrix with columns that are equal to the basis functions and α is a vector whose elements are the coefficients to be determined. The solution that minimizes the sum-squared error is: α=( l T l ) −1 l T L.   (19) Table 2 shows the seven coefficients for several standard CIE illuminants (D 65 , D 50 , m, m 2 , m 3 , m 4 ). The coefficients were calculated using Eq. (19). FIG. 3 shows the spectrum of the D 65 illuminant as given in Wyszecki and Stiles, Color Science Concepts and Methods, Quantitative Data and Formulae , John Wiley & Sons, New York, 2d ed., 1992, along with values of the illuminant calculated using the seven basis functions of Table 1. TABLE 1 Basis Functions for General Outdoor Illumination λ(μM) I 1 (λ) I 2 (λ) I 3 (λ) I 4 (λ) I 5 (λ) I 6 (λ) I 7 (λ) 0.3300 0.0532 0.0052 0.0016 −0.1830 0.0430 −0.1055 −0.5521 0.3400 0.0937 −0.8586 −0.1109 0.0257 0.0015 0.0148 0.0390 0.3500 0.0891 −0.4957 0.1223 −0.0290 −0.0026 −0.0259 −0.0674 0.3600 0.0866 −0.0236 0.9816 0.0435 0.0013 0.0079 0.0208 0.3700 0.0831 0.0080 0.0203 −0.2123 −0.0179 −0.1339 −0.3438 0.3800 0.0813 0.0086 −0.0005 −0.1986 −0.0272 −0.1213 −0.2579 0.3900 0.0840 0.0091 −0.0012 −0.1889 −0.0352 −0.1118 −0.1827 0.4000 0.1134 0.0126 −0.0024 −0.2330 −0.0538 −0.1331 −0.1473 0.4100 0.1315 0.0148 −0.0036 −0.2470 −0.0649 −0.1361 −0.0833 0.4200 0.1425 0.0163 −0.0048 −0.2415 −0.0697 −0.1269 −0.0068 0.4300 0.1388 0.0161 −0.0056 −0.2112 −0.0642 −0.1045 0.0562 0.4400 0.1539 0.0182 −0.0071 −0.2067 −0.0638 −0.0934 0.1190 0.4500 0.1819 0.0218 −0.0095 −0.2144 −0.0641 −0.0857 0.1861 0.4600 0.1853 0.0224 −0.0106 −0.1892 −0.0512 −0.0606 0.2178 0.4700 0.1864 0.0229 −0.0117 −0.1612 −0.0346 −0.0352 0.2339 0.4800 0.1884 0.0233 −0.0127 −0.1367 −0.0165 −0.0039 0.2311 0.4900 0.1855 0.0232 −0.0133 −0.1081 0.0042 0.0230 0.2140 0.5000 0.1864 0.0235 −0.0141 −0.0858 0.0254 0.0584 0.1831 0.5100 0.1882 0.0239 −0.0150 −0.0644 0.0480 0.0928 0.1437 0.5200 0.1769 0.0227 −0.0147 −0.0392 0.0679 0.1172 0.0901 0.5300 0.1877 0.0242 −0.0161 −0.0246 0.0954 0.1712 0.0282 0.5400 0.1893 0.0245 −0.0168 −0.0055 0.1208 0.2062 −0.0339 0.5500 0.1884 0.0245 −0.0173 0.0123 0.1427 0.2304 −0.0887 0.5600 0.1860 0.0243 −0.0175 0.0257 0.1400 0.2291 −0.1013 0.5700 0.1821 0.0240 −0.0177 0.0461 −0.0362 0.2755 −0.1421 0.5800 0.1858 0.0246 −0.0185 0.0610 0.0191 0.2260 −0.1311 0.5900 0.1663 0.0224 −0.0177 0.0928 −0.3606 0.3014 −0.1338 0.6000 0.1762 0.0237 −0.0188 0.0967 −0.1353 0.2176 −0.1193 0.6100 0.1898 0.0255 −0.0203 0.1037 0.2057 0.0724 −0.0702 0.6200 0.1908 0.0259 −0.0212 0.1281 0.2201 0.0013 −0.0459 0.6300 0.1842 0.0253 −0.0213 0.1505 0.0640 −0.0058 −0.0547 0.6400 0.1870 0.0259 −0.0224 0.1760 0.0768 −0.0936 −0.0631 0.6500 0.1675 0.0235 −0.0213 0.2000 −0.2801 −0.0493 −0.0503 0.6600 0.1772 0.0249 −0.0227 0.2125 0.0099 −0.1980 −0.0389 0.6700 0.1932 0.0272 −0.0250 0.2342 0.3032 −0.3494 −0.0107 0.6800 0.1880 0.0267 −0.0249 0.2463 0.2726 −0.3813 0.0056 0.6900 0.1494 0.0216 −0.0208 0.2332 −0.2863 −0.1531 0.1226 0.7000 0.1487 0.0217 −0.0215 0.2639 −0.5648 −0.2076 −0.0590 Each choice of the weighting coefficients (α 1 , α 2 , α 3 , . . . , α 7 ) will yield a unique illuminant for which the camera can be calibrated from Eq. (15). Each choice of illuminant will result in a different minimum value of the cost function given by Eq. (15). The illuminant that yields the smallest minimum cost functions is the best estimate of the illuminant incident on the color chart. Once the illuminant is estimated, the calibration process can proceed as detailed above. TABLE 2 Coefficients for Standard Illuminants Illum. α 1 α 2 α 3 α 4 α 5 α 6 α 7 D 50 −2.63 × 10 4 1.81 × 10 5 −8.90 × 10 4 −4.11 × 10 3 −1.18 × 10 2 1.52 × 10 2 −2.65 × 10 1 D 65 −3.44 × 10 4 2.56 × 10 5 −7.33 × 10 4 −5.43 × 10 3 −1.90 × 10 2 7.16 × 10 1 −6.67 × 10 1 m 1 −2.38 × 10 4 2.12 × 10 5 −1.73 × 10 4 −2.51 × 10 3 −1.23 × 10 2 1.30 × 10 2 −1.88 × 10 2 m 2 −1.56 × 10 4 1.08 × 10 5 −7.47 × 10 4 −2.90 × 10 3 −8.32 × 10 1 1.67 × 10 2 −1.10 × 10 2 m 3 −1.08 × 10 4 4.51 × 10 4 −1.11 × 10 5 −3.06 × 10 3 −5.68 × 10 1 1.54 × 10 2 −9.86 × 10 1 m 4 −4.86 × 10 3 −9.19 × 10 3    −1.23 × 10 5 −2.59 × 10 3 −3.23 × 10 1 1.02 × 10 2 −1.19 × 10 2 The process for estimating the illuminant is an optimization inside of an optimization. The inner optimization determines a cost for a given illuminant, as discussed above, implying for every choice of coefficients, (α 1 , α 2 , . . . , α 7 ), there will be a cost, C, given by: C = ∑ i = 1 N ⁢ Δ ⁢ ⁢ E ab * , ( 20 ) where N is the number of standards used. For every value of the illuminant we have a different value of C. The first optimization finds the optimal transformation matrix, T full , as shown in Eq. (16). The outer optimization adjusts the coefficients defining the estimated illuminant until a minimum in the total cost is achieved. The computational intensity of this process is largely due to the fact that T full has 27 unknown values and the outer optimization has to optimize the 7 coefficients that define the illuminant. FIG. 4 shows a flow chart of the optimization process. Both optimization routines may utilize use code adapted from Numerical Recipe's AMOEBA routine, which uses a downhill Simplex method. See, W. H. Press, et al., Numerical Recipes, 1996. The Simplex method, although slow, is robust for the problem at hand. Although the Simplex method is used in a preferred embodiment according to the invention, other search methods to obtain an optimal solution could be used, including but not limited to Simpson's, Powell, Levenberg-Marquardt, Davidon, or Newton-like methods. With reference to the flow chart of FIG. 7 , the determination of the illuminant spectrum may be summarized as follows: 1. Using N color standards find the raw RGB value for each standard (block 50 ). 2. Assume initial illuminant spectrum (block 51 ). 3. Calculate initial tristimulus value for the standards based on assumed illuminant (block 52 ) 4. Find the optimal solution matrix T in the color Lab space given the illuminant (block 53 ), where T full ⁡ [ R G B R 2 G 2 B 2 RG RB GB ] = [ X / X n Y / Y n Z / Z n ] 5. Derive a new estimate of the illuminant L(λ) using optimization techniques such as Simplex methods (block 54 ). 6. Use the new illuminant to calculate tristimulus values (block 55 ) and repeat step 4 (at block 53 ). 7. Find the illuminant spectrum which minimizes the Lab cost function (block 54 ) and save that spectrum for use in calibration of the image as discussed above. This process may be iterated until the cumulative error in Lab coordinates is less than a selected value. FIG. 8 shows a preferred embodiment of an apparatus according to the invention for estimating the spectral power density of an unknown illuminant. The apparatus includes a camera, shown generally at 10 . In a preferred embodiment, the camera may be one of any number of digital cameras which are widely available, such as the Nikon D1 or Kodak DCS-420 digital cameras. The camera may also be a film camera of the type which is well known in the art. The apparatus further includes a plurality of color standards, shown generally at 30 . The plurality of color standards may be a commercially available chart of color standards, such as the Macbeth ColorChecker product available from GretagMacbeth 617 Little Britain Road New Windsor, N.Y. 12553-6148. Alternatively, the color standards may be specially made to emphasize particular regions of the color spectrum if greater accuracy in those specific regions of the color spectrum is necessary or desirable. As shown in FIG. 8 , the plurality of color standards 30 is illuminated with an illuminant 36 of unknown spectral power density. The illumination may come from a natural source of illumination, such as the sun 35 , or the illumination may come from a source of artificial light. The apparatus includes a digital computer, shown generally at 20 . The digital computer can be one of any number of commercially available digital computers, of the types which are well known in the art and widely available, such as the IBM ThinkPad laptop computer model X20. Although the embodiment shown in FIG. 8 contemplates the use of a separate standalone digital computer in an apparatus according to the invention, the digital computer could be built in to the digital camera 10 . The apparatus includes an image transfer means for transferring image information, indicated generally at 15 , between the camera 10 and the digital computer 20 . If the camera 10 is a digital camera, the image information, such as color output signal or tristimulus values, may be transferred via a cable (such as a Universal Serial Bus cable), via some form of optical or magnetic media (such as a compact disk, flash memory card, or floppy disk), or via a wireless method (such as infrared or radio frequency). If the camera is a film camera, the means for transferring image information might be a photographic print or negative of the image coupled with a scanner device which can digitally scan the photographic print or negative to produce digital image information which can be transferred into the digital computer 20 . The camera 10 of FIG. 8 is operated to take an image of the plurality of color standards 30 illuminated with an illuminant 36 having an unknown illuminant spectrum, and the image information is transferred via the image transfer means 15 to the digital computer 20 . The digital computer is programmed to receive the image information, and to process the image information to estimate the power spectral density of the unknown illuminant spectrum, consistent with the preceding discussion. The following example discusses simulations that illustrate the calibration method of the invention for arbitrary illuminants. First we will discuss simulating the data, then the optimization techniques used to estimate the illuminant. The choice of illuminant for the simulation example was restricted to standard CIE daylight values. After reading in an illuminant, the color coordinates for the color chart used for the simulation can be determined following Eq. (6). The reflectance curves for the MacBeth color checker were used for the simulation, and the color matching functions were those shown in FIG. 1 . Many digital cameras 10 have a gamma correction applied to the RGB values which we denote as R′, G′, and B′. This gamma correction must be removed to obtain the raw RGB response of that camera . Other digital cameras 10 , such as the Nikon D1, have a raw format in which the gamma correction is not applied to the pixel values, and for these digital cameras there is no need to remove a gamma correction. To estimate the camera response (RGB) for a given set of color coordinates we calculate the pseudo inverse of T full given in Eq. (16), where T full has been determined from measured data. It is understood that the transformation matrix for a given camera is not constant, but will vary given the conditions under which the photo was taken. To make a realistic simulation, we also added noise to the RGB values, corresponding to measurement noise of the camera. Once again, zero-mean random Gaussian noise vector is added to each of the RGB values, with the standard deviation given by σ cam =R/SNR cam ,  (21) with similar equations used for the blue and green channels. After generating simulated data, the simulation estimates the illuminant incident on the color standards. The calibration process for the camera is then undertaken with the illuminant estimated, values of L*, a*, and b* are found based on the estimated illuminant, and these values are then compared with the values calculated using the original simulated illuminant. The purpose of the simulation is to demonstrate the ability of the calibration method of the invention to achieve sound results for illuminants that are close to standard daylight. In addition, adding noise to the RGB values shows how camera noise affects the overall accuracy of the results. FIG. 6 shows tabulated values of the CIE standard illuminant D 65 along with the estimated illuminant obtained from the optimization methods discussed above. The starting values for the coefficients, α 1 's, were the coefficients for the D 50 illuminant. The spectrum of D 50 is distinctly different from that of D 65 , and yet the estimation technique of the invention is found to be quite robust in terms of the starting values of the coefficients. FIG. 5 shows both the CIE standard illuminants D 50 and D 65 , and illustrates that the spectral nature of these illuminants is distinct. As can be seen in FIG. 6 , the estimated illuminant is not as accurate as one could obtain by measuring, but yields detailed spectral information based only on the measured RGB values and the reflectance curves of the color standards. Estimating the illuminant by this method is only a computational burden that can be done after the imaging session. Table 3 shows the results of a limited number of simulations to help examine the statistical soundness of the calibration method. The results detail which illuminant was used to generate the color standards, the SNR (signal-to-noise ratio) level for the camera's RGB values, the average of the color difference between the best fit and the generated standards, and the standard deviation for the color difference results. The starting values of the coefficients in the case of illuminant D 65 were the coefficients for D 50 , and for illuminant D 50 so the starting point was D 65 . As a rule of thumb, perceptible color difference can be discerned by the observer when ΔE* ab is greater than 3; perusal of the data will show that not only is the average difference less than the perceptibility limit but it is also more than 15 standard deviations away from the limit. TABLE 3 Results of Color Difference Estimates Camera Num. of Std. Dev. Illuminant SNR Num. of Runs Colors Ave. ΔE* ab ΔE* ab D 65 50 50 24 .248 .174 D 65 100 50 24 .252 .194 D 50 50 50 24 .229 .188 D 50 100 50 24 .243 .191 It is possible to estimate the illuminant in a manner similar to that discussed above but by finding the illuminant directly instead of fitting for the coefficients in the linear expansion. The number of parameters to fit in the optimization process for the illuminant jumps from seven linear coefficients to the total number of points in the desired illuminant. The number of data points in the illuminant will be the same as the number of color standards. For example, using the MacBeth Colorchecker, which has 24 colors, there are 24 data points in the estimated illuminant. The spectral resolution obtained by using the MacBeth Colorchecker would equal (700 nm−380 nm)/23, which is approximately 14 nm. Tabulated values for one of the CIE standard daylight illuminants, such as D 65 , may be used as the initial values for the optimization process. To increase the resolution in the estimated illuminant, a larger number of color standards could be used. In addition to the MacBeth Colorchecker, any other appropriate color standard may be utilized. It is understood that the invention is not confined to the embodiments set forth herein as illustrative, but embraces all such forms thereof as come within the scope of the following claims.

An apparatus and method for estimating the power spectral density of an unknown illuminant that does not require direct spectral measurements. The apparatus and method allows calibration of color images taken with commercially available digital cameras in arbitrary illumination. Besides an imaging system, a digital computer, a means for transferring image information from the imaging system to the digital computer, and software to carry out the method, the only additional equipment a photographer needs is a set of color standards.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2008 018 015.7, filed Apr. 9, 2008; the prior application is herewith incorporated by reference in its entirety. BACKGROUND OF THE INVENTION Field of the Invention [0002] The invention relates to a method of detecting a pressure loss of a tire in a vehicle equipped with a tire pressure monitoring system. The invention further relates to a tire pressure monitoring system, a vehicle, and a computer product program. [0003] The field of the present invention is systems for monitoring or determining tire-specific parameters. Such systems are generally referred to as tire information systems, tire monitoring systems or tire pressure monitoring systems. [0004] As vehicle safety and reliability are central factors in automotive engineering, for safety reasons alone the tire pressure of motor vehicles has to be regularly checked. As this is often neglected, modern motor vehicles increasingly have tire pressure monitoring systems, which are intended to automatically measure the tire pressure and provide early detection of a critical deviation of the measured tire pressure from a tire pressure setpoint value. [0005] A tire pressure monitoring system typically contains at least one electronic wheel device per wheel, which is disposed for example in the region of the wheel rim and contains a sensor for acquiring tire-specific parameters of the respective wheel and sending out information derived from this measured value of the parameters. The electronic wheel device is equipped with a sending aerial, by which the acquired information may be sent to a vehicle-side receiving device. On the vehicle side the tire pressure monitoring system contains at least one receiving device, by which the radio signals emitted from the electronic wheel device are picked up and routed to a central processing unit of the vehicle for further evaluation. [0006] A special functionality of a tire pressure monitoring system relates to so-called parked monitoring. With parked monitoring, the electronic wheel devices are activated also in the parked state and in this case determine tire-specific parameters, such as for example the tire pressure. During the parked state these collected tire-specific parameters are sent to the central control and evaluation device, where they are evaluated. The particular advantage of this parked monitoring functionality is that, when the vehicle is next started up, the actual tire-specific parameters are immediately available. [0007] In a tire pressure monitoring system without this parked monitoring functionality the requisite tire-specific parameters are determined only after start-up of the vehicle and are therefore available to the driver only at the start or shortly after the start of a fresh journey. While for most passenger vehicles this delay in the availability of the tire-specific parameters is substantially tolerable, it poses a problem particularly for commercial vehicles, such as heavy goods vehicles (HGV) of a haulage company. Often such HGVs are loaded before the start of a fresh journey. The wheels of the vehicle are accordingly subjected to extreme stress. As a result of this stress it may happen that for example the tire pressure of one or more wheels falls below a minimum threshold value, thereby making it necessary to change this wheel in order to guarantee that the vehicle is in proper working order. As this could not be detected before the start of the journey, the cargo would either have to be unloaded from the HGV or its trailer in order to change the defective tire or tires or the cargo would have to be reloaded onto a different HGV. Both measures entail a loss of time and with it a temporary vehicle failure that particularly in the case of heavy goods vehicles, which should have as little time laid-up as possible, is especially serious. [0008] For these reasons, it is particularly advantageous above all especially for such commercial vehicles if they have the previously described parked functionality for the tire pressure monitoring system. [0009] Generally known tire pressure monitoring systems with such a parked monitoring functionality are, on the one hand, permanently activated in the parked state and hence even in the parked state determine the appropriate tire-specific parameters and send corresponding signals to the vehicle-side evaluation device. Because during parked monitoring these functional units are permanently activated, this method is relatively energy-intensive and, as the vehicle and the electronic wheel devices are supplied with energy only from local energy sources, use of this method over a prolonged period is impossible or possible only to a qualified extent. [0010] In another, generally known method the electronic tire device determines the tire pressure continuously, for example at preset intervals. The electronic tire device sends information about the tire pressure to the vehicle-side evaluation device only if the tire pressure falls below a defined threshold. This occurs also in the parked state. The advantage of this solution is that the information about the tire pressure is available immediately after a fresh start-up of the vehicle. With this method, however, the local energy supply of the electronic tire device is in particular very quickly exhausted. What is more, this method does not take account of the laden state and hence of the stress acting upon the vehicle wheel that is to be monitored. With this method, moreover, it is impossible to detect from the electronic tire device whether the signal it has sent has also actually been received at the vehicle side. SUMMARY OF THE INVENTION [0011] It is accordingly an object of the invention to provide a method of detecting a pressure loss of a tire, a tire pressure monitoring system, a vehicle, and a computer product program that overcomes the above-mentioned disadvantages of the prior art methods and devices of this general type, which detects the tire pressure of a vehicle situated in the parked state in an energy-optimized manner. [0012] There is accordingly provided a method of detecting a pressure loss of a tire in a vehicle equipped with a tire pressure monitoring system. The method includes the following steps carried out in the parked state of the vehicle: deactivate the tire pressure monitoring system, which contains at least one electronic wheel device disposed in a vehicle wheel, activate the tire pressure monitoring system after a first defined period of time or upon a vehicle-side request, determine tire-related information of the vehicle wheels associated with the electronic wheel devices by use of the respective electronic wheel device and generate status signals containing the tire-related information, communicate the status signals to an evaluation device, return to the first method step at the latest after a second period of time. [0013] A tire pressure monitoring system for or in a vehicle, contains at least one electronic wheel device, which is disposed in a vehicle wheel of the vehicle having a parked monitoring device, which is configured to implement a method according to the invention in the parked state of the vehicle. [0014] A vehicle, in particular a tractor and/or the trailer of a lorry, which has a plurality of vehicle wheels each containing a wheel rim and a tire fitted thereon and which is equipped with the tire pressure monitoring system according to the invention. [0015] In addition, a computer program product, which defines an algorithm that contains the method according to the invention, is provided. [0016] The present invention presupposes that the tire pressure monitoring system of a vehicle is equipped with a so-called parked monitoring functionality, whereby the central control and evaluation device of the vehicle may be activated at least intermittently also in the parked state of the vehicle. In the parked monitoring mode the control and evaluation device of the vehicle has a reduced functionality, which is however at least capable of “waking up” the electronic wheel devices associated therewith by a corresponding signal so that these electronic wheel devices in the parked state may determine tire-specific parameters and send them back to the control and evaluation device. This has the particular advantage that even before the start of a fresh journey and hence still in the parked state the actual tire information and in particular the actual tire pressure of the various wheels of the vehicle may be displayed for a vehicle driver. [0017] This is particularly advantageous for vehicles, for which it is important to be informed about a possible defect in a vehicle wheel and in particular about a pressure loss in a vehicle wheel before the start of a journey. This applies above all, but not exclusively, to commercial vehicles such as HGVs and tractor-trailers. In this way possible defects of the vehicle wheel, such as for example too low a tire pressure, may be detected and eliminated before, for example, such a vehicle is loaded for the next journey. As a result, extended periods laid-up because of a final loading and/or reloading of the cargo of the commercial vehicle are reduced to a minimum. [0018] The underlying idea of the present invention is that during a parked state of a vehicle first to deactivate the parked monitoring. The parked monitoring is however activated regularly after a defined period of time in order to be able to determine the appropriate tire-related information. The tire-related information is then sent in the form of a status signal to a vehicle-side receiving device in order to enable vehicle-side evaluation of this information. Subsequently or at least after a further defined period of time the parked monitoring mode is deactivated again. [0019] The first and the second defined period of time are so dimensioned that on the one hand the requisite tire-related information may be obtained, sent out in the form of a status signal and also received at the vehicle side. On the other hand, the energy resources both of the energy source of the electronic wheel device and of the vehicle are to be conserved as much as possible. For this reason, the first defined period of time is typically selected relatively long compared to the second defined period of time, i.e. in the range of several hours to one or a few days, while the second defined period of time is in comparison shorter, typically in the region of one hour or less. [0020] The particular advantage of the present invention is that in the parked state of the vehicle the parked monitoring mode does not remain continuously switched on. Rather, the parked monitoring mode is activated regularly, i.e. at regular intervals in each case for a relatively short duration in order then to be able to determine the appropriate tire-related information and send it to a vehicle-side evaluation device. Subsequently or after a defined time the parked monitoring mode is then deactivated again and also remains deactivated for a comparatively longer period of time. Because the parked monitoring mode is activated only for a short time and then deactivated for a longer time, the energy requirement for supplying the parked monitoring function of the tire pressure monitoring system is reduced to a minimum. Equally, however, it is thereby ensured that this tire-specific information and in particular the tire pressure is made available to the driver of the vehicle before the start of a fresh journey so that, particularly in the event of a fault, he may initiate the appropriate countermeasures before setting out on a journey. [0021] In a typical refinement, the second period of time is markedly shorter than the first period of time. Markedly shorter, in this connection, means that the second period of time is shorter for example at least by the factor 10 and in particular by the factor 25 than the first period of time. For example, the first period of time is at least 6 hours and in particular at least 12 hours. Preferably, the first period of time is at most 24 hours. The second period of time is for example at most 90 minutes and in particular at most 30 minutes. The second period of time depends for example upon the intervals, at which the electronic wheel device sends. [0022] The electronic wheel device in the parked state is preferably always activated and is therefore configured to pick up tire-specific information also in the parked state and send it out in the form of status signals. Alternatively, the wheel electronic device may be “woken up” by the vehicle-side control device. The generated status signals are sent from the electronic wheel device in the parked state at intervals, i.e. in each case after a third defined period of time. This third defined period of time is preferably at least shorter than the second defined period of time. In this way it may be ensured that within the second period of time, during which at the vehicle side the tire pressure monitoring system is activated, a status signal is sent also at least once from the respective electronic wheel device to the vehicle-side receiving device. In case the electronic wheel device sends out the appropriate status signals in a time interval of for example 30 minutes (i.e. third period of time), the second period of time would therefore have to be at least 30 minutes. [0023] In a particularly preferred refinement, the second period of time is lengthened if from at least one electronic wheel device no status signal was able to be received at the vehicle side. In particular, the second period of time is lengthened in such a way that from the various electronic wheel devices a total of two or more status signals may then be sent out within the second period of time. If however after a correspondingly lengthened period of time it is still not possible to receive a status signal from the electronic wheel device or devices at the vehicle side, then the tire monitoring system is deactivated again, even though a status signal has not been received from all of the electronic wheel devices. In this case, it is assumed for example that even with a further lengthened period of time not all of these electronic wheel devices are possibly able to send a status signal to the vehicle-side receiving device because they are situated for example in a send and/or receive dead spot. It may be assumed for example that, if an electronic wheel device sends out 2 to 4 status signals but these cannot be received at the vehicle side, then such a state of a send and/or receive dead spot exists. This is to be taken into account in the case of lengthening of the second period of time, i.e. in this case the second period of time should be at least two to four times the third period of time. This prevents excessive demands being placed on the energy source of the tire pressure monitoring system. [0024] In a particularly preferred refinement, the tire pressure monitoring system is immediately deactivated as soon as all of the electronic wheel devices have sent their status signals and these status signals have also been received by a vehicle-side receiving device. In this situation the tire pressure monitoring system need not continue to maintain the parked monitoring mode as the objective thereof, namely the sending and receiving of the status signals, has in this case already been prematurely achieved. This is likewise an energy-saving functionality. In addition, it may also be provided that the premature deactivation occurs only after the status signals received at the vehicle side have also been acknowledged and optionally already evaluated at the vehicle side. [0025] In a likewise preferred refinement, the method is terminated after a predetermined number of returns in accordance with the method step (e), provided that the parked state is not interrupted during this time, i.e. in this case the parked monitoring mode remains deactivated during the parked state also after the first period of time. This is likewise an energy-saving functionality as it may for example be assumed that after the predetermined number of returns and hence after the predetermined number of activated parked monitoring modes there is a specific probability that the tire-related information will no longer vary further. A further monitoring of this tire-related information is therefore also obsolete. [0026] In a particularly preferred refinement, an electronic wheel device, which in the method step (c) was unable to determine appropriate tire-related information and/or for which in the method step (d) it was not possible to send the status signals to the evaluation device, remains deactivated after a renewed activation in a subsequent method step (b). This procedure occurs in particular after a return in the method step (e) and after a fresh activation of the tire pressure monitoring system. Here, it is assumed that the electronic wheel device that remains deactivated is either situated in a send and/or receive dead spot or is at any rate defective. In these situations a fresh attempt to determine tire-related information with this electronic wheel device would very probably lead to the same negative results, i.e. the result here would once more be that there was no tire-related information to determine and/or appropriate status signals to be received at the vehicle side. [0027] In a likewise preferred refinement, the status signal is sent from the electronic wheel device to a vehicle-side receiving device, wherein the status signal is sent via a telematic device provided in the vehicle to a vehicle-external evaluation device. Additionally or alternatively, the status signal may be sent to the central control and evaluation device inside the vehicle in order to display the tire-related information directly to the driver. What is more, the company, to whose fleet the vehicle belongs, may therefore initiate countermeasures early, particularly given tire-related information that indicates for example a defect or fault in the vehicle wheel. These countermeasures may for example provide for a change of the inferior tire or, in the case of too low a tire pressure, for a re-inflation of this tire in order to minimize the risk of a flat or burst tire and the cost-intensive interruption of the journey that this would entail. [0028] In a typical refinement, the electronic wheel devices in the parked state are first deactivated and are not activated until a wake-up signal is sent from the vehicle side. This prevents the electronic wheel devices in the parked state from continuously sending signals, which places excessive demands on the vehicle side owing to the deactivated tire pressure monitoring system and hence the receiving device thereof. [0029] In a likewise preferred refinement, immediately after termination of the parked state a determination of the tire-related information is carried out afresh even in electronic wheel devices, which during the parked state were not able to determine tire-related information and/or from which the status signals generated by the electronic wheel device were not able to be received on the vehicle side. This tire-related information may then, i.e. after termination of the parked state, be sent in the form of corresponding status signals to the vehicle-side receiving device and evaluation device. Thus, for the sake of completeness, even electronic wheel devices that could not be monitored during the parked state for example because of a send and/or receive dead spot may send their status signals. [0030] In a particularly preferred refinement, the status signal contains information about the tire pressure. In particular, the vehicle-side evaluation device outputs an error signal if the determined tire pressure falls below a defined pressure threshold. This error signal is available to the vehicle driver and/or a control centre of the fleet, to which the vehicle belongs, even before the start of a fresh journey. In a particularly preferred refinement, this defined threshold is adjustable, for example in dependence upon the loaded state of the vehicle. In this way, it is possible to take account of the loaded state of the vehicle and the stress acting upon a respective tire in the unladen and laden state. [0031] In a particularly preferred refinement, the first defined period of time is shortened and/or the second defined period of time is increased if in the course of evaluation it emerges that the tire-related information contains an error or at least a deviation of the respective tire-related information from a defined standard range. In this way too, a faulty deviation may be counteracted early. [0032] In a particularly preferred refinement, the electronic wheel device contains a sensor for determining the tire-related information. Such tire-specific information is for example the tire temperature, the tire pressure, the rotational speed of a tire, the tread thickness etc. In particular the electronic wheel device contains a pressure sensor, which also in the parked state is configured to determine the tire pressure of the wheel associated with this electronic wheel device. [0033] In a preferred development, the monitoring device contains a telematic device, by which the status signals may be sent as radio signals to a vehicle-external evaluation device. The telematic device may be for example a component part of the navigation system and/or of a radio telephone in the motor vehicle. These devices are naturally in communicative connection with base stations and in this way may be connected by a simple function extension also to a vehicle-external control centre, for example within a haulage company. [0034] It is likewise preferred if the parked monitoring device contains an electronic-wheel-side memory device, in which the status signals and/or the wheel-specific information may be stored at least for the duration of the parked state. Preferably, the memory device and/or a vehicle-side evaluation device is reset to its initial state after termination of the parked state and before a fresh parked state. [0035] In a particularly preferred refinement, the parked monitoring device contains a time generator, which defines the first and/or the second defined period of time. This time generator may for example take the form of a clocked counter. [0036] The refinements and developments of the invention described in detail above may—unless otherwise stated—be combined freely with one another. [0037] Other features which are considered as characteristic for the invention are set forth in the appended claims. [0038] Although the invention is illustrated and described herein as embodied in a method of detecting a pressure loss of a tire, a tire pressure monitoring system, a vehicle, and a computer product program, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. [0039] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING [0040] FIG. 1 is a schematic plan view of a vehicle for the purpose of explaining an embodiment of a tire pressure monitoring system according to the invention; [0041] FIG. 2 is a block diagram of an exemplary layout of an electronic wheel device of a tire pressure monitoring system according to the invention; [0042] FIG. 3 is a sequence diagram for explaining a first embodiment of the method according to the invention; and [0043] FIG. 4 is a sequence diagram for the purpose of explaining a second embodiment of the method according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0044] In the figures of the drawing, unless otherwise indicated, identical and functionally identical elements, features and signals are provided with the same reference characters. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown an extremely simplified schematic representation of a vehicle for the purpose of explaining an embodiment of a tire pressure monitoring system according to the invention. In FIG. 1 reference character 10 denotes a vehicle, for example a heavy goods vehicle (HGV). The vehicle 10 here has merely by way of example six wheels 11 . The vehicle 10 further has a tire pressure monitoring system according to the invention, which contains wheel-side electronic wheel devices 13 , vehicle-side receiving devices, a bus 17 , and a control unit 18 . One electronic wheel device 13 is associated with each individual wheel 11 . The electronic wheel device 13 is disposed in a manner known per se in the region of the valve or the rim of the respective wheel 11 . [0045] FIG. 2 shows in a block diagram a schematic layout of an electronic wheel device 13 . The electronic wheel device 13 in the case of the present embodiment contains a pressure sensor 21 , a processing device 22 connected to the pressure sensor 21 , an internal memory 24 , and a transmitter 23 connected to the processing device 22 . These elements 21 - 24 are supplied with electrical energy in each case from a local energy supply 25 , for example an accumulator or a battery. The wheel sensor 21 is configured to determine tire-specific parameters, such as for example the tire pressure. The processing device 22 of the electronic wheel device 13 carries out a pre-evaluation of the information obtained by the wheel sensor 21 . The wheel-specific information determined by the electronic wheel device 13 is modulated and/or encoded in a transmission signal X, which here is referred to also as status signal X and is sent via a wireless communication link to the vehicle 10 . For this purpose, each electronic wheel device 13 contains a sending aerial 20 as a component part of the transmitter 23 . [0046] For receiving the sent transmission signals X the tire pressure monitoring system contains at the vehicle side at least one and in the present case two receiving devices 15 , each of which contains a receiving aerial 16 . The receiving device 15 is supplied in a manner not represented here with electrical energy from an energy source 12 of the HGV 10 , for example the vehicle battery, and contains in each case a receiving aerial 16 and a receiving stage 26 . [0047] The tire pressure monitoring system further contains at the vehicle side a microprocessor 19 as an example of a central control and evaluation device 19 . The microprocessor 19 and optionally also the receiving stage with the receiving aerial 16 are component parts of the control unit 18 for the tire pressure monitoring. The control unit 18 , the receiving devices 15 and the electronic wheel devices 13 are provided for the purpose of measuring the respective tire pressures in the various wheels 11 , evaluating the measured tire pressures and visually or audibly informing a person driving the HGV, who is not represented in detail, if one of the tires for example has too low a tire pressure. [0048] The tire pressure monitoring system further contains a bus 17 , for example a single- or two-wire CAN bus (CAN=controller area network) or a LIN bus (LIN=local interconnect network), to which the receiving devices 15 and the control unit 18 are connected by respective connection lines. [0049] The tire pressure monitoring system according to the invention further has a parked monitoring device. The functionality of the parked monitoring device is implemented i.e. in the electronic wheel devices 13 and the central control and evaluation device 19 . The electronic wheel device 13 here is merely by way of example configured in such a way that it is or may be activated also in a parked mode of the vehicle 10 . In this parked mode the central control and evaluation device 19 of the vehicle 10 may be in a so-called parked monitoring mode, in which it is activated for the purpose of parked monitoring at least intermittently and in particular at regular intervals. [0050] The HGV further contains a telematic device 29 , which is connected for example to the control unit 18 and via which the picked-up status signals X may be sent also to a vehicle-external central evaluation device (not represented in FIG. 1 ). The vehicle-external central evaluation device may be for example a central computer of a company, to whose fleet the lorry belongs. [0051] There now follows a detailed description of this mode of operation of the parked monitoring device according to the invention with reference to the sequence diagram in FIG. 3 . [0052] It is assumed that at the start of the method according to the invention the vehicle is in a parked mode V 1 . [0053] In the parked mode, the tire pressure monitoring system is first deactivated in the method step V 2 , i.e. initially the electronic wheel devices 13 do not send any status signals X to the vehicle-side evaluation device 19 . [0054] This deactivated state of the tire pressure monitoring system is maintained for the first defined period of time Δt 1 (step V 3 ). This defined period of time Δt 1 is preferably adjustable and, depending on the application, user requirement, existing energy resources etc., is in the region of a few hours to a few days. A typical value of the first period of time Δt 1 is: Δt 1 =6 h-24 h. [0055] After the first defined period of time Δt 1 , at least the parked monitoring functionality of the tire pressure monitoring system is activated (step V 4 ). In the activated state measurement signals relating to tire-specific parameters, for example the tire pressure, are picked up by the electronic wheel device 13 (step V 41 ). From these measurement signals the electronic wheel device 13 generates a status signal X (step V 42 ) that contains information about the measured tire-specific parameter or parameters. The status signal X is sent out in the next sub-step V 43 and is picked up in the sub-step V 44 by a vehicle-side receiving device 15 specifically provided for this purpose. After corresponding routing of this status signal X to the evaluation device 19 , the status signal is then evaluated in the sub-step V 45 . [0056] In the step V 5 the information thus evaluated is displayed for example for the vehicle driver. This may occur preferably even before the start of a fresh journey, i.e. while still in the parked state, or alternatively upon or shortly after the start of a fresh journey. It would additionally or alternatively be possible to display the tire-specific information obtained in the step V 4 via a telematic device to a vehicle-external user. [0057] The parked monitoring mode remains activated for a second defined period of time Δt 2 (step V 6 ). The second period of time Δt 2 corresponds at least to the time, during which an electronic wheel device 13 is typically intermittently activated, i.e. picks up measurement signals and sends out status signals X derived therefrom. [0058] After the second defined period of time Δt 2 the method returns (step V 7 ). As a result, the tire pressure monitoring system and in particular its parked monitoring functionality are deactivated again in the step V 2 . This return after the second defined period of time Δt 2 (steps V 6 , V 7 ) occurs even if in the step V 4 status signals X have not been generated by all of the electronic wheel devices 13 and/or been received by the vehicle-side receiving device. [0059] In an extension it may also be provided that the method returns already some time before achieving the second defined period of time Δt 2 (step V 7 ), if for example at the vehicle side corresponding status signals X have been received from all of the electronic wheel devices 13 of the tire pressure monitoring system. In this situation, there is therefore no longer any need to continue to maintain the parked monitoring mode. This is therefore an energy-saving extended function. [0060] FIG. 4 shows a method according to the invention that is extended compared to the first embodiment in FIG. 3 . [0061] In contrast to the embodiment in FIG. 3 , in FIG. 4 after the second defined period of time Δt 2 in step V 6 it is checked whether at the vehicle side status signals X have been received from all of the electronic wheel devices 13 . If status signals X have been received from all of the electronic wheel devices 13 , then the method returns as in FIG. 3 (step V 7 ). If, on the other hand, in the step V 8 it is identified that at the vehicle side there are not status signals X from all of the electronic wheel devices 13 , then the method returns in the step V 9 to the method step V 4 . As a result, for a further second period of time Δt 2 an attempt is made to obtain status signals X from the respective electronic wheel devices 13 . This may be effected at all of the electronic wheel devices 13 , regardless of whether status signals have already been obtained from these, or alternatively only at the electronic wheel devices 13 , from which status signals have still not been obtained. [0062] This return in the step V 9 may be effected until corresponding status signals have been obtained from all of the electronic wheel devices 13 . If an electronic wheel device 13 is defective or is situated in a send and/or receive dead spot, it may from time to time be impossible to receive corresponding status signals X from this electronic wheel device 13 at the vehicle side. In order therefore not to place excessive demands on the limited energy resources 12 , 25 of the electronic wheel device 13 and the vehicle 10 , according to the invention it is provided that after a defined number of returns V 9 , which are counted in the step V 10 , this method and therefore the attempt to obtain corresponding status signals X from all of the electronic wheel devices 13 is aborted. The method then returns in the step V 7 , so that the tire pressure monitoring system and/or the parked monitoring mode may then be deactivated again. [0063] It may additionally also be provided that after a defined number of returns V 7 , which are counted in the step V 11 , the method according to the invention, i.e. the activating and deactivating of the parked monitoring mode at regular intervals, is aborted. In this case, in the method step V 12 the tire pressure monitoring system and hence also its parked monitoring functionality is permanently deactivated, wherein in this case the deactivated state is maintained until the parked state is terminated. [0064] For determining the various periods of time Δt 1 -Δt 3 and intervals the vehicle-side tire pressure monitoring system comprises a time generator 27 . [0065] The invention is suitable for any vehicles, such as for example buses, tractor-trailers, HGV trailers, passenger cars and the like. [0066] The previously described tire monitoring systems further refer to concrete devices in a vehicle.

A method for detecting a pressure loss of a tire in a vehicle equipped with a tire pressure monitoring system. The method includes the following steps carried out in the parked state of the vehicle: deactivate the tire pressure monitoring system, which contains at least one electronic wheel device disposed in a vehicle wheel, activate the tire pressure monitoring system after a first defined period of time or upon a vehicle-side request, determine tire-related information of the vehicle wheels associated with the electronic wheel devices by the respective electronic wheel device and generate status signals containing the tire-related information, communicate the status signals to an evaluation device, return to the first method step at the latest after a second period of time.

FIELD OF THE INVENTION [0001] The present invention consists of a process allowing the growth of yeasts and bacteria strains on a substrate in a bioreactor, thus resulting in the production of a valuable biomass rich in protein for animal and/or human consumption. This process intends to fix an environmental problem. BACKGROUND OF THE INVENTION [0002] Many by-products are a nuisance to the dairy industry, limiting its growth because of environmental problems that these by-products cause, especially those related to getting rid of the whey and/or other by-products, such as the permeate resulting from the extraction of whey proteins. Volumes of these by-products are important, because the manufacture of one kilogram of cheese generates about nine kilograms of whey which contains about 50 g/L of lactose and less than 10 g/L of soluble serous protein. Manufacturing of a ton of cheese generates as much pollution as city with a population of 5000. Wastewater treatment plants do not accept whey and dairy by-products in municipal sewers as they deregulate the microbial flora and induce bulking. It is also forbidden to bury this waste because of its organic charge. [0003] Dairy industries can treat the whey by extracting lactose but letting the mother liquors or by obtaining dehydrated whey protein concentrate. However, these methods do not get rid of the mother liquors which are salted, or permeate rich in lactose. Serous protein extraction is costly, and there is a lack of interest by the market towards lactose products. Membrane processes weakly reduce the lactose problem because they remove only the serous proteins and leave intact the lactose which is the essential constituent of whey. Another solution is to spread the whey over a field but large surfaces are required and it is limited by the Sodium Absorption Ratio (SAR). [0004] It has been estimated that 90% of the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in whey comes from lactose. Whey COD is estimated to range from 35,000 to 71,000 ppm, while whey BOD ranges from 16,000 to 33,000 ppm, depending on the specific cheese-making process. [0005] Sugars are the main pollutants of these by-products (in whey, lactose represents 75% of the weight of dry ingredients) and are therefore targets for biological processes. [0006] Fermentation by lactose-positive Crabtree-negative yeast or bacteria has been proposed as an efficient approach to reduce the COD and BOD of whey by reducing the sugar content and, to a lesser extent, the protein content. [0007] Fermentations are usually performed with a single strain in fed-batch under optimal conditions of pH, temperature, agitation and dissolved oxygen, under high production controls to insure purity of the strain. For each new batch, the seeding must be done with a new fresh inoculum. However, monoculture, with either yeast or bacteria, has its disadvantages. Each strain is often able to metabolize only one specific substrate. Furthermore, monocultures are more subject to contamination. They therefore need drastic cleanness conditions of operations, rendering the process weak and unstable. [0008] A process in the treatment of industry effluents is described in U.S. Pat. No. 5,811,289A (Lewandowski et al.). The process was tested on an industrial scale over several years. This patent discloses the treatment of effluents containing different sources of sugar with a very large variety of strains in order to get rid of these effluents in an environmentally safe way. However, the process is not intended to start from whey. Furthermore, it may be difficult to obtain approval of governmental regulatory authorities for a product associated with several different strains. [0009] There is still a need to get rid of substrates with a high COD and/or BOD in a safe way for the environment and to obtain edible compositions for human or animal consumption. SUMMARY OF THE INVENTION [0010] The invention provides a process for producing a biomass for animal and/or human consumption from a substrate comprising simple sugars, the process comprising the steps of: a) providing a combination of yeast and bacterial strains b) mixing the substrate with the strains to obtain a mixture and c) allowing fermentation of the mixture between about 20 and 50° C. to obtain the biomass. [0014] The invention provides a process as described therein, wherein the substrate is selected from the group comprising dairy products, dairy by-products, pea residues, beet residues and sugar cane residues. [0015] The invention provides a process as described therein, wherein the strains are [0000] a Kluyveromyces marxianus yeast strain deposited at the International Depositary Authority of Canada (IDAC) under the accession number 150709-01; a Saccharomyces unisporus yeast strain deposited at the IDAC under the accession number 150709-02; and a Lactobacillus fermentum bacterial strain deposited at the IDAC under the accession number 150709-03. [0016] The invention provides a combination of yeasts and bacteria comprising: A Kluyveromyces marxianus yeast strain; A Saccharomyces unisporus yeast strain; and A Lactobacillus fermentum bacterial strain. [0020] The invention provides a combination of yeasts and bacteria, wherein the strains are a Kluyveromyces marxianus yeast strain deposited at the International Depositary Authority of Canada (IDAC) under the accession number 150709-01; a Saccharomyces unisporus yeast strain deposited at the IDAC under the accession number 150709-02; and a Lactobacillus fermentum bacterial strain deposited at the IDAC under the accession number 150709-03. [0024] The invention provides a use of a combination of yeasts and bacteria comprising: A Kluyveromyces marxianus yeast strain; A Saccharomyces unisporus yeast strain; and A Lactobacillus fermentum bacterial strain for preparing a biomass edible for humans or animals, by fermentation of a substrate. [0029] The invention provides a biomass obtained by the process of the invention. DETAILED DESCRIPTION OF THE FIGURES [0030] FIG. 1 is a flow sheet diagram of a process, in accordance with a first embodiment of the present invention. Dotted lines represent facultative steps. [0031] FIG. 2 is a flow sheet diagram of a process, in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0032] The present invention is a process for the treatment of a substrate containing simple sugars using a co-culture of yeasts and bacteria working in symbiosis for getting rid of these sugars thus reducing the organic charge of the substrate, while obtaining an edible biomass rich in protein for animal or human consumption. [0033] This process allows a strong reduction of the organic charge of the substrate through a biological way: yeast and/or bacterial strains metabolize the components of the substrate and produce a biomass. [0034] Strains. [0035] Strains have been selected for their value in food consumption (production of single cell-protein, prebiotic and/or probiotic effect, Crabtree-negative, high growth yields), their ability to grow in harmony and their ability to metabolize the substrate. This consortium of strains grows on a substrate containing a source of fermentable sugar under specific and astringent conditions. [0036] In one embodiment, these strains contain at least one strain metabolizing the sugar present in the substrate and a second strain using the metabolites or sugar hydrolysed by the first strain. [0037] Strains described in U.S. Pat. No. 5,811,289A (Lewandowski et al.) were isolated. Amongst a large variety of strains, two strains were selected and identified, and a third one added. [0038] In one embodiment of the invention, three different strains are included: two yeasts and one bacterial strain. In one embodiment, the genus of these strains is Kluyveromyces sp., Saccharomyces sp. and Lactobacillus sp. In one embodiment, these strains are Kluyveromyces marxianus, Saccharomyces unisporus and Lactobacillus fermentum . These strains are adapted to fermentation conditions and are able to grow in symbiosis. In one embodiment, in order to reach the best conditions for the process of the present invention, no other strain is added. [0000] Kluyveromyces marxianus [0039] Kluyveromyces marxianus is a species in the genus Kluyveromyces. K. marxianus is used commercially to produce the protease, invertase and lactase enzymes. It is widely used in the food industry, especially in dairy products and bread making. It is a member of the normal human microflora. It grows at 30-45° C. and is able to assimilate lactate. [0040] Yeasts of the Kluyveromyces genus are widely known for their use in industrial scale biomass production and lactose fermentation. K. marxianus has been cited for its ability to efficiently ferment lactose in whey. In conjunction with lactose hydrolysis, a yeast biomass is produced that is a potential source of Single-cell protein (SCP). Kluyveromyces marxianus is reported to have a crude protein content of approximately 50%. [0041] Several studies have also looked at the possibility of using partially purified β-galactosidase (lactase) to reduce the lactose content of whey. Obviously, this approach does not result in biomass production. Kluyveromyces marxianus produces intermediate metabolites that reduce yeast biomass yields. [0000] Saccharomyces unisporus [0042] Saccharomyces unisporus is a yeast which vigorously ferments only some monosaccharides, one of which is galactose. It gives rise to slower and less clean alcoholic fermentation than Saccharomyces cerevisiae , since it produces larger quantities of minor compounds such as glycerol, succinic acid and acetic acid. Saccharomyces unisporus is a low alcohol producer, it cannot bring the grape must fermentation to an end, in fact it halts at a level of 7 vol % in ethanol. [0043] Saccharomyces unisporus is different from Saccharomyces cerevisiae , the baker's yeast representative of the genus. Sacharomyces unisporus forms asci that generally contain a single spore. [0044] Saccharomyces unisporus is found in many foods, including fermented fruit juices and, especially, dairy products. Saccharomyces unisporus is the principal alcoholic fermentation microorganism of traditional koumiss. However, it is an undesirable species in fermented vegetables because it is a non-pathogenic spoilage yeast. [0045] Saccharomyces unisporus has been isolated from fermented milk (kefir, Villi), whey, and cheeses like Armada, Salers cheeses and goat cheeses. Saccharomyces unisporus is present in all these products, but usually at a lower concentration than other yeast species that ferment lactose such as Kluyveromyces spp. [0000] Lactobacillus fermentum [0046] Lactobacillus fermentum is a Gram-positive species of bacterium in the genus Lactobacillus. [0047] Lactobacillus fermentum is an obligatory heterofermentative bacterium that produces CO 2 from glucose and pentoses. The optimum growth temperature of L. fermentum is between 30 and 40° C. Lactobacillus fermentum is phylogenetically a close relative of Lactobacillus reuteri , a food-borne probiotic bacterium. It can be isolated from numerous habitats, including human, chicken, or quail intestines, the mouth, human or rat feces, human breast milk, goats' milk, fermented beets, cheeses, cereal dough, manure, and silage. Many strains of this species are considered probiotics. Several strains have been assayed in clinical trial studies in humans and chickens. Some are commercialized for human intestinal or urogenital applications (e.g., Lactobacillus fermentum RC-14, Chr. Hansen A/S). [0048] These three microbial strains are known to grow at 37° C., at pH7 in either aerobic or anaerobic conditions. All three strains are capable of growing in the Mann Rogosa Sharpe Agar (MRSA) medium. All yeast strains are capable of growing in Tryptic soy agar (TSA) and Potato dextrose agar (PDA) medium. Lactobacillus fermentum is also able to grow on TSA and PDA media, but its growth rate is slower and it forms micro colonies. [0049] In one embodiment, these strains are commercial strains and/or obtained from dairy industries. In one embodiment, the commercial strains are chosen from the following Table 1: [0000] Strains International collection Kluyveromyces ATCC 10022 marxianus ATCC 28244 ATCC 8554 CBS 6556 CBS 7894 CCT 4294 FII 510700 IMB3 NCYC 111 NRS 5790 PTCC 5193 ZIM 1867 Saccharomyces ATCC 48553 unisporus ATCC 48555 ATCC 58440 BR 174 BR 180 Lactobacillus ATCC 8289 fermentum ATCC 9338 ATCC 11739 ATCC 11740 ATCC 11976 ATCC 14931 ATCC 14932 ATCC 23271 ATCC 23272 ATCC 53609 CRL 722 CRL 251 IFO 3956 [0050] In another embodiment, the invention further relates to the following strains: A Kluyveromyces marxianus yeast strain deposited at the International Depositary Authority of Canada (IDAC) under the accession number 150709-01; A Saccharomyces unisporus yeast strain deposited at the IDAC under the accession number 150709-02; and A Lactobacillus fermentum bacterial strain deposited at the IDAC under the accession number 150709-03. [0054] These strains are resistant to important thermal variations and/or pH variations. [0055] Substrates. [0056] The substrate comes from an edible source for animal or human. The substrate contains fermentable sugars. The substrate has a chemical oxygen demand (COD) ranging from 35,000 to 71,000 ppm and/or a biochemical oxygen demand (BOD) ranging from 16,000 to 33,000 ppm. The substrate includes dairy products and/or dairy by-products such as fresh cheese whey, dehydrated whey, whey permeate, deproteinized whey, mother liquors and the like, delactosed permeate (DLP). Mother liquor is a generic term intended to cover the liquid left after extraction of a soluble substance by crystallisation, obtained through evaporation of the substrate. Despite its name, DLP still contains a lot of lactose. [0057] Whey or milk plasma is the liquid remaining after milk has been curdled (or coagulated) and strained, when milk casein proteins have been precipitated either with rennet (leading to sweet whey, and large grain of curd and then to hard cheese like Cheddar or Swiss) or with acid (leading to acid whey, also called Sour whey, and small grains of curd, and then to acid types of cheese such as cottage cheese). 20% of non-casein proteins (mainly lactoglobulins) are not precipitated through this process, they are soluble and called serous proteins. 80% of these non-casein proteins will precipitate at higher temperatures, within a specific pH range and constitute Ricotta cheese. The 20% of remaining proteins are thermostable. [0058] Permeate is the term used to describe the milk-sugar (lactose) and minerals part of whole milk. Permeate is produced by passing whey through a fine sieve to separate milk sugars and minerals from milk protein and fat at room temperature. Proteins are therefore not denatured as opposed to the Ricotta process. [0059] Mother liquor is the liquid left after crystallisation of sugars contained in the permeate, which has been concentrated through evaporation. The mother liquor has a COD ranging from about 200, 000 to 300 000 ppm and a BOD ranging from about 90,000 to 140,000 ppm. In one embodiment the mother liquor has a COD of about 260,000 and a BOD of about 12,000 ppm. [0060] These substrates contain simple sugars such as hexoses (C-6 sugars), pentoses (C-5 sugars), osides or polyoses, holosides, diholosides (lactose, saccharose, maltose, melibiose) or triholoside (raffinose) which are metabolized by the process while other substances such as proteins and lipids remain almost intact. When they are precipitated or solids, these substances gather together with solids generated by the process to be separated with them at a later stage. The result is an edible biomass for animals and/or human. [0061] The following Table 2 lists the sugars and other compounds assimilated and/or fermented by the strains of the invention. [0000] TABLE 2 K. marxianus S. unisporus L. fermentum Glucose + + + Galactose + + + Lactose + − + Saccharose + − + Raffinose + − + Inuline + − − Maltose − − + Melibiose − − + Ethanol + − − Lactic acid + − − Succinic acid + − − Glycerol + − − Sorbitol + − − Mannitol + − − Ribose + − − Arabinose + − − [0062] In one embodiment, whey is used as the substrate as it is edible. In one embodiment, the substrate is used within 24 hours of its production in order to keep the lactose available. 24 hours after its production, lactic fermentation may arise, inducing a pH reduction, leading to sour whey. Sour whey containing lactic acid is still assimilated by Kluyveromyces marxianus. [0063] Whey is kept at the temperature it was produced in the dairy, i.e. between 30 and 55° C. [0064] In another embodiment, other substrates, such as pea residues, beet residues or sugar cane residues, found in processing plants or candy factories, containing at least one fermentable sugar are used. [0065] Pasteurization. [0066] Upon its delivery, the substrate may be treated to avoid the development of the original flora in the bioreactor. Pasteurization can either be conducted by applying heat or chemical treatment. The heat treatment is applied between about 72 to 75° C. during about 15 to 60 seconds. In one embodiment, the heat treatment is applied at about 72° C., during about 15-25 seconds. With the chemical treatment, from about 50 to 3000 ppm, or in a further embodiment from about 500 to about 800 ppm, of hydrogen peroxide is added to the raw material for a retention time of about 2 to 3 hours. H 2 O 2 is added in excess to reach pasteurization, the residual hydrogen peroxide will have no effects on the bioreactor flora due to the presence of the catalase enzyme, and water and O 2 will appear rapidly. [0067] Serous Protein Precipitation. [0068] A higher thermal treatment may be applied (from about 80° C. to about 95° C., in a further embodiment from 90° C. to 95° C., during about 30 seconds to 30 minutes, in a further embodiment during 3 to 5 minutes, or even during 30 seconds to 1 minute, or at about 80° C. for about 5 to 10 minutes), after or instead of pasteurization, to promote recovering of serous proteins by precipitation. For this specific operation, the pH is adjusted to its isoelectric point, between about 3.5 and about 6.5, depending on the time and the temperature of the reaction. In one embodiment, the pH is adjusted between about 3.5 and 5.9. The precipitated proteins are then withdrawn by centrifugation or transferred in the bioreactor thus providing a higher protein level in the final product. Other methods may also be used for the withdrawal of serous protein such as ultrafiltration or nanofiltration. [0069] Dilution. [0070] Substrate is diluted, either with city water or addition of clarified water coming from the centrifuge to reduce the COD to between 28 g/L and 50 g/L and the BOD to between 13 et 23 g/L, allowing a better assimilation of the sugar by microorganisms. In one embodiment, dilution occurs after pasteurization and cooling. In another embodiment, dilution occurs after pasteurization but before cooling. [0071] Fermentation. [0072] Substrate, either pasteurized or unpasteurized, is then treated to reach optimal pH and temperature conditions for the process, including nitrogen based nutrients' addition, such as ammoniac salts, urea or others. Incoming substrate may have a pH ranging from between about 3.3 and 7, but pH will be set between about 1.8 and 5.0 for batch fermentation or between about 1.8 and 4 for continuous fermentation. The strains of the invention are able to sustain important pH variations. Such pH variations may be decided in order to prevent and/or fix a contamination problem, and then the pH is readjusted to its usual value. [0073] The fermentation process of the invention works either in batch mode, fed batch mode or continuous mode. In one embodiment, the fermentation starts with a batch before being in continuous mode. [0074] In batch mode, a fresh culture is used every time the process is started. The bioreactor is filled with the prepared substrate to be fermented. The temperature and pH for microbial fermentation is properly adjusted, and other components are added. Fermentation proceeds, and after the proper time the contents of the bioreactor, are taken out for solid recovery. The bioreactor is cleaned and the process is repeated. [0075] In fed batch mode, the substrate is added gradually to the bioreactor. This fermentation process is used for preserving flora in exponential growth phase. The fermented substrate is not withdrawn until the end of the fermentation. The bioreactor is cleaned and the process is repeated. [0076] In the continuous mode, a volume of substrate is added continuously at various rates to the existing culture in the bioreactor, although feeding can be stopped once most of the fermentable sugar is consumed, while withdrawal of the fermented substrate is performed continuously also. In some cases, it can be kept unfed, under certain circumstances, even though no sugar remains. This state is called dormancy. This mode of operation is useful when there is disruption in raw substrate feeding, to accommodate personnel shifts, management or for other reasons. The dormancy state can be applied in the process, at the fermentation step. To promote dormancy conditions in the bioreactor, temperature is adapted to ensure that the quality of the strains is maintained, while preventing growth of pathogens, aeration is turned off, thus no oxygen is available while pH is either maintained at its usual level for short period of dormancy (a few hours) or reduced for longer period of dormancy (a few days), and agitation is reduced. The temperature is also adjusted depending on the length of the dormancy period. In one embodiment, the temperature is reduced from about 40° C. to about 20° C. (room temperature). In another embodiment, the temperature is reduced to about 4° C. for a longer period of dormancy, up to a year. [0077] Addition of the substrate is performed either from the top or the bottom of the bioreactor. In one embodiment, injection of substrate is done from the top of the bioreactor. Sugar in the substrate is gradually consumed before the liquid, which is the culture itself, and is also called the liquor, is withdrawn at the bottom of the reactor and is then either recirculated in the bioreactor or directed towards a separation system. In one embodiment, the liquor is recirculated by a pump through the recirculation loop of the bioreactor. [0078] The bioreactor is prepared to receive an initial quantity of media including raw material, dilution liquid, microorganisms and ingredients. The operation and control instruments allow for following the initial fermentation's evolution and to set the parameters and conditions adjusted allowing for growth, the parameters and conditions being: pH, dissolved oxygen, temperature, input of nutrients and biocatalyst. When the growth is optimized, the bioreactor is fully loaded. After the adaptation and cell growth stage, supply and recirculation can be activated. Fermentation takes place at a pH between 1.8 and 5.0. Maintaining this low pH limits the intrusion of other strains including any type of pathogens because this condition of operation creates bactericide and/or bacteriostatic conditions. [0079] Fermentation mode is mostly microaerophile but also anaerobic. These two modes are possible because the aeration ramp is placed slightly above the tank's bottom and circulation of the liquor in the bioreactor is performed from the bottom through the top via the recirculation loop of the bioreactor. The generated air bubbles run to the surface, leaving the space below the ramp unfed with oxygen allowing growth of anaerobic species. The ventilation allows yeasts to produce more biomass. Furthermore, no alcohol was produced, due to the use of the Crabtree-negative strain Kluyveromyces marxianus. [0080] The average age of the flora is between about 4 and about 50 hours. In one embodiment, the age of the flora is between 12 and 15 hours. The age of the flora has an impact on the productivity of the biomass and the depuration yield (or the COD reduction). With a younger age, a better biomass production is obtained. With an older age, a better depuration yield (or the COD removal yield) is obtained. [0081] The strains' growth produces an exothermal reaction, producing from about 2000 to about 2300 KWh of calorific energy per ton of sugar, which is able to raise the culture temperature up to about 50° C. but fermentation conditions are generally maintained between about 20 and 50° C., in one embodiment between about 30 and 40° C., or in a further embodiment between about 35 and 40° C., by a cooling system, for optimal growth. The cooling system can be installed either directly within the bioreactor, for example, with serpentines, or externally, with a liquid/liquid heat exchanger. The calorific energy may be used to heat fluids in the plant. [0082] The invention also provides a system composed of means to control the conditions of the process, including a pH probe, a pH meter, pumps for injecting acid or base for regulating the pH, an oxygen probe, an oxygen meter, a temperature meter, a thermal system, a biocatalyst including a nitrogen dosage and an injection system. [0083] Feeding of the bioreactor is managed in accordance with different parameters that control the flow rate input function of the bioreactor. A system of air diffusers placed from the bottom of the tank feeds the liquor with fine bubbles. This aeration system induces oxygenated (over the ramp) and anoxic (under the ramp) zone at a time in the bioreactor. The volume of injected air is kept at a level that maintains the level of oxygen almost to about 0 mg/L, but less than about 3.0 mg/L. Nitrogen based nutrients, a biocatalyst and an antifoaming agent are used in appropriate amounts to support the reaction. [0084] The invention provides aeration means such as a blower powering the air diffusers, including an oxygen source, and a pipe for air to go out and a cyclone for aerating said liquor. It also includes first programming means, controlling said first varying means and including liquor dissolved oxygen detecting and measuring means coupled to said first programming means; an acid metering pump, connected to said bioreactor vessel; means for maintaining the dissolved oxygen content in the culture at a rate at a desired level, (in one embodiment, between about 0 to about 2 mg/L); second programming means, controlling said pump to vary acid injection into said vessel, to maintain pH at a settled point wherein the pH range is maintained between 1.8 and 5.0; a recirculation loop means to induce a movement to the liquor in the bioreactor, therefore it is not necessary to have stirring means such as helix. [0085] Foam formation is a drawback in any bioreactor. The foam may be dispersed either with a foam breaker or a recognized chemical antifoam solution, such as canola oil or milk cream. In one embodiment, the foam is dispersed with the cleaning balls, acting as a foam breaker, providing a jet of liquid. This jet of liquid works well when the foam is mild or not abundant, but it is only partially effective in reducing thick foam or when foam is produced at higher rates. [0086] It is possible, to a certain extent, to customize the composition profile of the final product by adding a biocatalyst into the raw material. Basically, the biocatalyst consists of a predetermined mixture of elements such as minerals, vitamins and others. If the concentration of one of the constituents of the biocatalyst is increased, this component is then more assimilated by the cell, which maintains it as a stored product. In other words, the flora involved in the process takes the mineral element added in sufficient amount and converts it into organic form. For instance, it is possible to produce cells with a higher lysine content or enriched metals such as selenium, chromium or other elements of interest. [0087] Solid/liquid Separation: [0088] Once fermented, the liquor coming out from the bioreactor is separated from its solid phase by an appropriate system. Separation is performed by centrifugation, membranes processes or by any other means of solid-liquid phase separation. [0089] Centrifuged biomass is partly or totally directed in a production tank. In the former case, the other partly centrifuged biomass is brought back toward the bioreactor in order to maintain the concentration of active flora at the level that provides for the complete transformation of sugars. [0090] Thus, the separated biomass composed of cells from flora may contain original precipitated serous protein retained from centrifugation as well as the metabolites resulting from the biological flora reactions, including enzymes adsorbed by the biomass. [0091] The biomass can be accumulated after the separation operation and maintained in a vessel under dormancy mode at room temperature, between pH 1.8 and 5.0, with agitation for many days (or at 20° C. for many weeks or at 4° C. for many months) until ready for further transformation. [0092] The clarified water is either sent to the sewer in an environmentally safe way, as the organic workload is lowered from 80 to 97%, or recirculated in the bioreactor with the aim of diluting the raw material. [0093] A facultative membrane filtration unit is installed and operated at this step. The system will reduce the COD of the clarified water coming out of the centrifuge and will recover all the material the centrifuge was unable to retain. The equipment could be composed of a membrane filtration unit, such as reverse osmosis or nanofiltration. [0094] Biomass Pasteurization: [0095] According to the desired product purpose, the biomass is processed thermally to inactivate the cells, through pasteurization for instance, if so required by regulatory authorities. Pasteurization can be conducted by applying heat treatment of 75° C., 60 seconds holding time. The equipment could be composed of a scraped surface heat exchanger. This type of exchanger is mandatory for pasteurization of thick liquids and sludges. [0096] Alternatively, the biomass is maintained in its liquid or freeze-dried unpasteurized state to preserve the probiotic strain character. [0097] Biomass Drying: [0098] At the end of this process, biomass is either retained in the form of press cake or a liquid and then packed, or concentrated by evaporation and dried by atomization or other means to obtain a paste, powder, flakes or granules. [0099] The invention provides fermented whey, spray dried. In one embodiment, it contains less about 2% of lactose or less. In another embodiment, it contains about 1% of lactose or less. In one embodiment, this product has a moisture level of about 7%. In one embodiment, this product further contains serous proteins. In one embodiment, the product is free of Salmonella, Pseudomonas, Staphylococcus, E. coli , coliforms, Aspergillus flavus, Fusarium and/or spore forming bacteria. [0100] Cleaning in Place (CIP): [0101] The equipment is cleaned and sanitized on a regular basis either manually or using the Cleaning in Place system (CIP), depending on the circumstances. Approved cleaning solutions are alternatively applied between rinsing cycles depending upon the contact time and at defined intervals in order to maintain sanitary conditions of the surfaces. The parameters of use are indicated in the cleaning instructions. In another embodiment, the cleaning of the bioreactor vessel occurs every 3 months. In yet another embodiment, the cleaning occurs every 6 months. [0102] Application. [0103] The process of the invention leads to the production of yeasts and bacteria, which by biosynthesis generate a wide range of products including proteins, oligosaccharides, vitamins and antioxidants, and fermentation metabolites with specific nutritional properties. Such product is a source of nourishment for humans and/or animals, such as livestock or pets, including juvenile animals (piglets, calves, calves of milk, lambs, fish etc.), that require a selective diet. [0104] It may also be used, among others, as a food ingredient, as an alternative for protein substitution at a lower cost, as a flavour enhancer aimed to increase food performance, as a nutritive product with high levels of organic micronutrients, as a lacto-replacer for milk calves or other animals or as a prebiotic for its oligosaccharides content. [0105] Different conditions of operation will lead to the obtaining of liquor with different reduced organic charges and of a biomass with different increased organic charges. Example 1 [0106] As shown in FIG. 1 , substrate is received in piping ( 1 ) where acids and bases ( 2 ) are added, when necessary, to adjust the pH to the appropriate value before being eventually admitted to a pasteurization system ( 3 ). [0107] Optionally, temperature substrate is further raised to ensure the precipitation of serous proteins. This step is achieved with equipment that allows for reaching of required time and temperature conditions ( 4 ). Temperature substrate is cooled with a cooling system ( 3 b ). [0108] To reduce the organic load, a dilution may be performed by injecting in ( 5 b ) city water ( 5 a ) or adding clarified water ( 12 c ) coming out ( 20 ) from the separation system ( 19 ). [0109] Substrate is admitted in through the top of the bioreactor vessel ( 6 ) that contains the fermenting liquor. [0110] The bioreactor is aerated by a system of air diffusers ( 7 ) powered by a blower ( 8 ), including an oxymeter. [0111] An area of anoxia ( 9 ) is located under the air diffuser ( 7 ). [0112] Air coming out of the bioreactor from piping ( 10 ), loaded with aerosols and foam, is admitted in the cyclone ( 11 ) which ensures the rejection of the condensates of aerosols either to the sewer ( 12 a ) or back to bioreactor ( 6 ), (through the piping ( 1 ) for instance) and expels aerosol-free air outside ( 13 ). In one embodiment, the foam first passes through a foam breaker ( 10 a ) [0113] The pH is regulated in the bioreactor by a system composed of a probe, a pump, a pH meter, and an acid ( 14 ). [0114] Nutrients, nitrogen and biocatalyst are injected into the bioreactor via the storage and injection system ( 15 ). [0115] The temperature of the bioreactor is regulated by a cooling system ( 17 ). [0116] The liquor of the bioreactor is recirculated through a recirculation loop ( 16 ) which prevents sedimentation of the liquor in the bottom of the bioreactor when there is a formation of a dead zone under the air dispensers. [0117] The liquor of the bioreactor is led by piping ( 18 ) connected to the recirculation loop to the system for solids separation ( 19 ). [0118] Clarified water ( 20 ) is redirected to the bioreactor ( 12 c ) or sewer ( 12 b ). [0119] A portion of the centrifuged biomass is recycled by piping ( 21 ) into the bioreactor. This line is used, if necessary, to seed the bioreactor in a continuous manner. [0120] Concentrated biomass is introduced in the production tank ( 22 ). [0121] Depending on the desired product, biomass can be pasteurized by a thermal treatment system ( 23 ). [0122] Biomass may be routed to a drying unit ( 24 ) by piping or packed under its liquid state or pressed to form a cake. [0123] The installation is fitted with a standard system of cleaning in place, not shown on the drawing. Example 2 [0124] A bioreactor containing conditioned (i.e. slightly diluted and added with urea and biocatalyst) and skimmed whey is seeded by using the three strains described in the present invention, Kluyveromyces marxianus, Saccharomyces unisporus and Lactobacillus fermentum , at pH 3.5 and to ambient temperature at 20° C. The aeration to which it is subjected causes an increase in the turbidity because of the growth of flora, while the temperature rises. Once the lactose is depleted, the bioreactor is fed with whey continuously. The heat generated by biological reactions is removed by a heat exchanger and a cooling system maintains the temperature between 35° C. [0125] The liquor coming out of the bioreactor is directed towards a centrifuge, which sends the biomass partly in a production tank while another part is recycled in the bioreactor in order to maintain a proper mass load. Clarified water is sent to the sewer. The system is stable and may, thus, remain for a long period without drift. Clarified water does not contain any more lactose, but does contain the major part of serous proteins, which are soluble and, whose flora does take only low molecular weight portion (peptides fraction), remain. Example 3 [0126] Another embodiment of the process of the invention is shown with example 3 and FIG. 2 . The following is a flowchart explanation of the plant operation on a 24 h-7 days/week schedule of the process including the cleaning-in-place system. A. Raw Whey Permeate Input [0000] Flow rate: 300 m 3 /day Temperature: 20° C. to 35° C. pH: 3.4 to 6.5 COD: 60-70 g/l B. Whey Permeate Buffer Tank [0000] 1 whey permeate buffer tank pH adjustment with caustic or acid solutions C. Pasteurization [0000] 2 HTST (Hot Temperature Short Time) pasteurizers in parallel operating at the same time or can be used alternately to allow cleaning and production Pasteurization at 72 to 75° C. with a 15 to 60 seconds holding time D. Pasteurized Whey Permeate Buffer Tank [0000] 2 pasteurized whey permeate buffer tanks Can be used alternately to allow cleaning and production at the same time They must be linked to a heat exchanger to regulate the temperature of whey permeate prior to being pumped in the bioreactors E. Whey Permeate Dilution [0000] Dilution may be performed by the injection of city water (E′) or the addition of clarified water (E″) coming from the centrifuges The aim is to reduce the COD to 30,000 ppm and to allow an optimal biomass production F. Bioreactors [0000] 3 aerobic/anaerobic bioreactors Bioreactor temperature must be controlled with a water tower evaporator (30-37° C.) Heat recovery from bioreactors is possible with heat exchangers Integrated air injection system should be installed G. Liquid Output from Bioreactors Constituents other than whey permeate are added in the bioreactors during the process, principally city water and clarified water Suspended solids: 13 to 18 g/l pH: 4 to 5 H. Centrifugation [0000] 3 centrifuges operating in parallel Cleaning of one centrifuge can be done while the other two assume production duties, ensuring continuous production and cleaning schedule I. Centrifuges Biomass Output [0000] Biomass flow rate: 40 m 3 /day Solids content: 15% (w/w) J. Biomass Buffer Tank [0000] 2 biomass buffer tanks Can be used alternately to allow cleaning and production at the same time pH of the biomass is monitored and maintained at a value where the fermentation is stopped and where the contamination is limited Continuous stirring is required to avoid the solids settling K. Biomass Pasteurization [0000] 2 scraped surface pasteurizers in parallel operating at the same time or alternately to allow cleaning and production Pasteurization at 72 to 75° C. with a 15 to 60 seconds holding time Scraped surface heat exchangers are mandatory for pasteurization of thick liquids and sludge L. Pasteurized Biomass Buffer Tank [0000] 1 pasteurized biomass buffer tank Continuous stirring is required to avoid solids settling Allow continuous feeding of the plate evaporator M. Plate Evaporator [0000] Biomass flow rate input: 40 m 3 /day (15% total solids) Biomass flow rate output: 24 m 3 /day (25% total solids) N. Concentrated Biomass Buffer Tank [0000] 1 concentrated biomass buffer tank Continuous stirring is required to prevent the solids from settling Allow continuous feeding of the spray dryer O. Spray Drying [0000] Input flow rate: 24 m 3 /day Air inlet temperature: 235° C. Air outlet temperature: 95° C. Product yield: 6 000 kg/day Moisture of product: 4% to 6% (w/w) 4˜6% Moisture content Proteins content: 35 to 40% P. Packaging [0000] Manual packaging line 500 kg bulk bags Q. Clarified Water [0000] Supernatant inputted from the centrifuges Suspended solids: 500 mg/l COD: 12 to 18 g/l R. Membrane Filtration Unit [0000] Clarified water (R′) is sent to the municipal sewer Retentate (R″) is sent to the biomass buffer tank (J) S. Cleaning in Place System Example 4 [0180] Another embodiment of the process of the invention is shown with example 4 and FIG. 2 . The following is a flowchart explanation of the plant operation on a 24 h-7 days/week schedule of the process including the cleaning-in-place system. A. Raw Whey Permeate Input [0000] Flow rate: 300 m 3 /day Temperature: 20° C. to 35° C. pH: 3.4 to 6.5 COD: 60-70 g/l B. Whey Permeate Buffer Tank [0000] 1 whey permeate buffer tank pH adjustment with caustic or acid solutions C. Pasteurization [0000] 2 HTST (Hot Temperature Short Time) pasteurizers in parallel operating at the same time or can be used alternately to allow cleaning and production Pasteurization at 72 to 75° C. with a 15 to 60 seconds holding time D. Pasteurized Whey Permeate Buffer Tank [0000] 2 pasteurized whey permeate buffer tanks Can be used alternately to allow cleaning and production at the same time They must be linked to a heat exchanger to regulate the temperature of whey permeate prior to being pumped in the bioreactors E. Whey Permeate Dilution [0000] Dilution may be performed by injection of city water (E′) or addition of clarified water (E″) coming from the centrifuges The aim is to reduce the COD to 50,000 ppm and to allow a more complete assimilation of the sugar F. Bioreactors [0000] 3 aerobic/anaerobic bioreactors Bioreactor temperature must be controlled with a water tower evaporator (35-42° C.) Heat recovery from bioreactors is possible with heat exchangers Integrated air injection system should be installed G. Liquid Output from Bioreactors Constituents other than whey permeate are added in the bioreactors during the process, principally city water and clarified water from centrifuge Suspended solids: 18 to 23 g/l pH: 3 to 4 H. Centrifugation [0000] 3 centrifuges operating in parallel Cleaning of one centrifuge can be done while the other two assume production duties, ensuring continuous production and cleaning schedule I. Centrifuges Biomass Output [0000] Biomass flow rate: 20 m 3 /day Solids content: 15% (w/w) J Biomass Buffer Tank [0000] 2 biomass buffer tanks Can be used alternately to allow cleaning and production at the same time pH of the biomass is monitored and maintained at a value where the fermentation is stopped and where the contamination is limited Continuous stirring is required to avoid solids settling K Biomass Pasteurization [0000] 2 scraped surface pasteurizers in parallel operating at the same time or alternately to allow cleaning and production Pasteurization at 72 to 75° C. with a 15 to 60 seconds holding time Scraped surface heat exchangers are mandatory for pasteurization of thick liquids and sludge L Pasteurized Biomass Buffer Tank [0000] 1 pasteurized biomass buffer tank Continuous stirring is required to avoid solids settling Allow continuous feeding of the plate evaporator M Plate Evaporator [0000] Biomass flow rate input: 20 m 3 /day (15% total solids) Biomass flow rate output: 12 m 3 /day (25% total solids) N Concentrated Biomass Buffer Tank [0000] 1 concentrated biomass buffer tank Continuous stirring is required to prevent the solids from settling Allow continuous feeding of the spray dryer O Spray Drying [0000] Input flow rate: 12 m 3 /day Air inlet temperature: 235° C. Air outlet temperature: 95° C. Product yield: 3 000 kg/day Moisture of product: 4% to 6% (w/w) 4˜6% Moisture content Proteins content: 40 to 45% P Packaging [0000] Manual packaging line 500 kg bulk bags Q Clarified Water [0000] Supernatant coming from the centrifuges Suspended solids: 500 mg/l COD: 6 to 12 g/l R Membrane Filtration Unit [0000] Clarified water (R′) is sent to the municipal sewer Retentate (R″) is sent to the biomass buffer tank (J) S Cleaning in Place System Example 5 [0234] Whey obtained from a cheddar plant and having a chemical oxygen demand of 71,000 mg/l is received in a continuous mode after dilution down to 28,000 mg/l with city water at a fluid input of 2.5 m3/hr in the bioreactor where there is maintained a constant volume of 30 m3 of liquor. This liquor has been previously seeded with Kluyveromyces marxianus (IDAC 150709-01), Saccharomyces marxianus (IDAC 150709-02), and Lactobacillus fermentum (IDAC 150709-03), at an initial concentration of each strain of 50%/30%/20%, respectively. This ratio will evolve to 60%/20%/10% in the bioreactor. [0235] The recirculated biomass rate is about 40%. At equilibrium, the concentration of suspended matter in the liquor is about 15 g/l and the dryness of the centrifuged biomass is about 15% in w/w. [0236] The average age of the flora is between about 2 and about 50 hours. In one embodiment, the age of the flora is about 12 hours. The gross productivity is about 10 g of biomass, dry basis, per m 3 of whey added in the bioreactor. [0237] The reduction yield of the chemical oxygen demand is about 78%. Example 6 [0238] Whey obtained from a Swiss cheese plant and having a chemical oxygen demand of 58,000 mg/l is received in a continuous mode after dilution down to 50,000 mg/l with city water at a fluid input of 2 m3/hr in the bioreactor where there is maintained a constant volume of 25 m3 of liquor. This liquor has been previously seeded with Kluyveromyces marxianus (IDAC 150709-01), Saccharomyces marxianus (IDAC 150709-02) and Lactobacillus fermentum (IDAC 150709-03), at an initial concentration of each strain of 48%/51.9%/0.1%, respectively. This ratio will evolve to 70%/29.9%/0.1% in the bioreactor. [0239] The recirculated biomass rate is about 25%. At equilibrium, the concentration of suspended matter in the liquor is about 20 g/l and the dryness of the centrifuged biomass is about 18% in w/w. [0240] The average age of the flora is between about 2 and about 50 hours. In one embodiment, the average age of the flora is about 16 hours. The gross productivity is about 9 g of biomass, dry basis, per m3 of whey added in the bioreactor. [0241] The reduction yield of the chemical oxygen demand is about 86%. Example 7 [0242] The process of the invention has been used with pea residues as the substrate. A reduction of 70% of the COD has been observed. This reduction is less than the one observed with whey as this substrate contains less sugar.

The present invention is directed to processes, combinations, uses and biomass comprising a combination of yeasts and bacterial strains, for the production of consumable biomass from substrates comprising a simple sugar. More particularly, the claimed subject matter includes the use of Lactobacillus fermentum, Kluyveromyces marxianus and Saccharomyces unisporus . The process intends to fix an environmental problem.

FIELD OF THE INVENTION [0001] The field of the invention relates to highly pure fexofenadine and a process for preparing highly pure fexofenadine of structural Formula I. The invention also relates to pharmaceutical compositions that include the highly pure fexofenadine and use of said compositions for treating a patient for allergic reactions. BACKGROUND OF THE INVENTION [0002] Chemically, fexofenadine is 4[1-hydroxy-4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]butyl]-α,α-dimethylbenzene acetic acid, of structural Formula I, and is known from U.S. Pat. No. 4,254,129. It is one of the most widely used antihistamines for the treatment of allergic rhinitis, asthma and other allergic disorders. [0003] In general, the synthetic approach reported in the literature for the preparation of fexofenadine involves the reduction of the ketone group of a carboxylate derivative, 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-α,α-dimethylbenzene acetate of structural Formula II, to get the corresponding hydroxyl derivative of structural Formula III, followed by hydrolysis with a base, for example alkali metal hydroxides to get a carboxylic acid derivative, fexofenadine. [0004] There are significant drawbacks to this approach as the reduction of the ketone group to the corresponding hydroxyl derivative of structural Formula III results in the formation of many impurities, of which the following impurities are difficult to remove: [0005] a. 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-α,α-dimethylbenzeneacetic acid, the impurity referred to as keto analog of fexofenadine, of structural Formula IV, and [0006] b. Meta-isomer of fexofenadine of Formula V. [0007] These impurities are further carried into the fexofenadine. [0008] The prior art approach is not suitable from commercial point of view because the desired para-isomer of fexofenadine is not obtained in high purity and requires purification by tedious and cumbersome purification processes. The generation of significant quantity of unwanted meta-isomer and lower yields makes the process uneconomical. [0009] The inventors have observed that during the reduction of methyl 4-[4-[4-(hydroxybiphenyl methyl)-1-piperidinyl]-1-oxobutyl]-α,α-dimethylphenyl acetate of structural Formula II, the product precipitates out as soon as about 80-90% conversion is achieved. Once the product is precipitated, it does not allow the reaction to go to completion and the unreacted starting material leads to the formation of impurities in the final product. To achieve a high efficiency of the reaction for industrial synthesis of fexofenadine, it is necessary to minimize the formation of the impurities and improve the yields. [0010] Thus, the present invention provides a process for the preparation of highly pure fexofenadine which does not require any further purification. SUMMARY OF THE INVENTION [0011] In one general aspect there is provided a highly pure fexofenadine or a salt thereof. [0012] In another general aspect there is provided substantially pure fexofenadine or a salt thereof having its keto analog less than 0.05%. [0013] In another general aspect there is provided highly pure fexofenadine or a salt thereof having its keto analog and meta-isomer, each less than 0.05%. [0014] In another general aspect there is provided a pharmaceutical composition that includes a therapeutically effective amount of highly pure fexofenadine or a salt thereof having its keto analog and meta-isomer, each less than 0.05%; and one or more pharmaceutically acceptable carriers, excipients or diluents. [0015] In another general aspect there is provided a process for the preparation of substantially pure fexofenadine or a salt thereof. The process includes reducing methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-α,α-dimethyl phenyl acetate of structural Formula II, with a reducing agent to produce a reduced product methyl 4-[4-[4-(hydroxybiphenyhnethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethyl phenyl acetate of structural Formula III; hydrolyzing the reduced product of structural Formula III in the presence of a base and a reducing agent; and isolating the substantially pure fexofenadine or a salt thereof. [0016] In general, fexofenadine prepared by any of the methods known in the literature may be purified to get substantially pure or highly pure fexofenadine or a salt thereof using the process of the present invention. [0017] In another general aspect there is provided a process for the preparation of substantially pure fexofenadine or a salt thereof. The process includes treating fexofenadine containing corresponding keto analog as an impurity with a base; adding reducing agent; and isolating the substantially pure fexofenadine having keto analog less than 0.05%. [0018] In another general aspect there is provided a process for the preparation of highly pure fexofenadine or a salt thereof The process includes treating fexofenadine containing corresponding meta-isomer as an impurity with a base; adding acid; and isolating the highly pure fexofenadine having keto analog and meta-isomer, each less than 0.05%. [0019] The process may include drying of the product obtained. [0020] The base may include one or more of alkali metal hydroxide, amide, alkoxide, alkali metal, or mixtures thereof. In particular, the base is alkali metal hydroxide. The alkali metal hydroxide may be lithium hydroxide, sodium hydroxide, or potassium hydroxide. In particular, the hydroxide is sodium hydroxide. [0021] The reducing agent may be sodium borohydride, potassium borohydride, tetralkyl ammonium borohydride, or zinc borohydride. In particular, the reducing agent is sodium borohydride. [0022] The details of one or more embodiments of the inventions are set forth in the description below. Other features, objects and advantages of the inventions will be apparent from the description and claims. DETAILED DESCRIPTION OF THE INVENTION [0023] The inventors have developed an efficient process for the preparation of substantially pure fexofenadine or a salt thereof, by reducing methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-l-oxobutyl]-α,α-dimethyl phenyl acetate of structural Formula II, with a reducing agent to produce a reduced product methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethyl phenyl acetate of structural Formula III; hydrolyzing the reduced product of structural Formula III in the presence of a base and a reducing agent; and isolating the substantially pure fexofenadine or a salt thereof. [0024] In general, the methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-α, α-dimethyl phenyl acetate may be treated with a reducing agent in the presence of a solvent, and the reducing agent may be added in small lots. [0025] The reducing agent includes any reducing agent which is capable of carrying out the reduction of the keto group, including, for example, sodium borohydride, potassium borohydride, tetralkyl ammonium borohydride, or zinc borohydride. In particular, the reducing agent is sodium borohydride. [0026] In general, after the reduction is complete, the reaction mass is acidified and the product is filtered. The reaction mass may be acidified with any acid, including, for example, acetic acid. [0027] In general, a solution of a base may be prepared by dissolving in water and treating the reduced product methyl 4[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α, α-dimethyl phenyl acetate with said solution. Alternatively, such a solution may be prepared in any solvent in which the base is soluble, including, for example, lower alkanols. [0028] The lower alkanol may include one or more of primary, secondary and tertiary alcohol having from one to six carbon atoms. The lower alkanol may include one or more of methanol, ethanol, denatured spirit, n-propanol, isopropanol, isobutanol, n-butanol and t-butanol. In particular, the lower alkanol may include methanol and ethanol. Mixtures of all of these solvents are also contemplated. [0029] The base includes alkali metal hydroxides, amides, alkoxides and alkali metals. The alkali metal hydroxides include any hydroxide, including, for example, lithium hydroxide, sodium hydroxide, and potassium hydroxide. [0030] The product may be isolated from the solution by a technique which includes, for example, filtration, filtration under vacuum, decantation, and centrifugation. [0031] The product may be further or additionally dried to achieve the desired moisture values. For example, the product may be further or additionally dried in a tray drier, dried under vacuum and/or in a Fluid Bed Drier. [0032] The inventors have also developed a process for the preparation of substantially pure fexofenadine or a salt thereof, by treating the fexofenadine containing corresponding keto analog as an impurity, with a base; adding reducing agent; and isolating the substantially pure fexofenadine or a salt thereof having keto analog less than 0.05% as determined by Reverse Phase—HPLC. [0033] The inventors have also developed a process for the preparation of highly pure fexofenadine or a salt thereof, by treating fexofenadine containing corresponding meta-isomer as an impurity, with a base; adding acid; and isolating the highly pure fexofenadine or a salt thereof having keto analog and meta-isomer, each less than 0.05% as determined by Reverse Phase—HPLC. [0034] The highly pure fexofenadine or a salt thereof thus obtained contains less than 0.1% of total impurities as determined by Reverse Phase—HPLC. [0035] Methods known in the art may be used with the process of this invention to enhance any aspect of this invention. The slurry containing the product may be cooled prior to isolation to obtain better yields of the fexofenadine and the product may be washed with a suitable solvent. [0036] The present invention is further illustrated by the following examples which are provided merely to be exemplary of the inventions and is not intended to limit the scope of the invention. Certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention. EXAMPLE 1 [0000] Preparation of Substantially pure fexofenadine Step A: Preparation of Methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α, α-dimethyl phenyl acetate [0037] Methyl 4-[4-[4(hydroxydiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-2,2-dimethylphenylacetate (20 g) was added to methanol (60 ml), at 25-35° C. followed by the addition of solid sodium borohydride (0.81 g) in small portions. The reaction mixture was further stirred at 25-35° C. for 2-3 hours and monitored by HPLC. The reaction was quenched with acetic acid and cooled to 0-5° C. The solid was filtered and washed with cold methanol, dried to get methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α, α-dimethyl phenyl acetate (18-18.5 g). Step B: Preparation of Substantially Pure fexofenadine [0038] Methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethylphenyl acetate (200 g) obtained in Step A was added to a mixture of ethanol (95%, 600 ml) and sodium hydroxide (23.2 g), and heated to reflux for about 3-4 hours. The reaction mixture was cooled to 50° C. and a solution of sodium borohydride (0.8 g) and sodium hydroxide (0.8 g) in water (10 ml) was added. The reaction mixture was again heated to reflux for about 1 hour and cooled to 8-10° C.; the product was filtered and washed with water and ethanol (95%). The material was dried to give 162 g of substantially pure product having keto analog less than 0.05%. EXAMPLE 2 [0000] Preparation of Highly Pure fexofenadine Step A: Preparation of Methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α, α-dimethyl phenyl acetate [0039] Methyl 4[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-2,2-dimethylphenylacetate (20 g) was added to methanol (60 ml), at 25-35° C. followed by the addition of solid sodium borohydride (0.81 g) in small portions. The reaction mixture was further stirred at 25-35° C. for 2-3 hours and monitored by HPLC. The reaction was quenched with acetic acid and cooled to 0-5° C. The solid was filtered and washed with cold methanol, dried to get methyl 4-[4-[4-(hydroxybiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α, α-dimethyl phenyl acetate (18-18.5 g). Step B: Preparation of Highly Pure fexofenadine [0040] Methyl 4-[4-[4-(hydroxybiphenyhnethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethylphenyl acetate (200 g) obtained in Step A was added to a mixture of ethanol (95%, 600 ml) and sodium hydroxide (23.2 g), and heated to reflux for about 3-4 hours. [0041] The reaction mixture was cooled to 50° C. and a solution of sodium borohydride (0.8 g) and sodium hydroxide (0.8 g) in water (10 ml) was added. The reaction mixture was again heated to reflux for about 1 hour and cooled to 8-10° C.; the product was filtered and washed with water and ethanol (95%). [0042] The wet product was suspended in ethanol (95%, 800 ml) and dissolved by adding a solution of sodium hydroxide (12.9 g) in water (12.9 ml). The solution was heated to 50° C. and the pH was adjusted to 6.7- 6.8 by adding 1:1 dilute hydrochloric acid. The product was isolated by cooling and filtration. The product was further dried to yield highly pure fexofenadine having keto analog and meta-isomer, each less than 0.05%. [0043] While several particular forms of the inventions have been described, it will be apparent that various modifications and combinations of the inventions detailed in the text can be made without departing from the spirit and scope of the inventions. Further, it is contemplated that any single feature or any combination of optional features of the inventive variations described herein may be specifically excluded from the claimed inventions and be so described as a negative limitation. Accordingly, it is not intended that the inventions be limited, except as by the appended claims.

The invention relates to highly pure fexofenadine and a process for preparing highly pure fexofenadine. The invention also relates to pharmaceutical compositions that include the highly pure fexofenadine and use of said compositions for treating a patient for allergic reactions.

FIELD OF THE INVENTION [0001] This invention relates to dry, leathery or semi-dry, paste-like cherry products. This application is a continuation in part of my provisional application Ser. No. 60/409,122 filed Sep. 9, 2002. BACKGROUND OF THE INVENTION [0002] Dried cherry products constitute a nutritious food item that combines an excellent fruit taste with low cholesterol content. This is particularly true with tart cherries, which lend themselves more readily to forming a dried product. In order to stabilize the product against becoming moldy sugar is added to the cherries. The problem with such cherry products is loss of flavor and/or firmness if sufficient sugar is added to stabilize the product for an adequate shelf life. It would therefore be desirable to have a product that provides a maximum of cherry flavor and yet is sufficiently stable so that it can be marketed. The present invention provides such a product. BRIEF DESCRIPTION OF THE INVENTION [0003] The present invention is based on the discovery that a maximum of cherry flavor can be retained in a dry (leather) or semi-dry (paste) cherry product by a process comprising (a) comminuting pitted cherries at about 20 to 27° F. by cutting to a particle size of about 20-80 microns, (b) separating about 40 to 70% by weight of the juice from the comminuted cherries by centrifugation (c) adding to the resulting product concentrated cherry juice having a Brix value of at least 50, but preferably 65 or higher in sufficient quantity to reconstitute from 65 to 75% of the sugar content of the original cherries and (d) drying the resulting product at temperatures not exceeding 160° F. to a desired moisture level to form a semi-dry or dry product. [0004] By cutting the cherries in the frozen condition rather than grinding them it is believed that more of the original cell structure can be retained which is believed in part to be the reason that the products of the present invention have a much stronger flavor than dry cherry products currently on the market. In addition to the cutting increased flavor and shelf life are obtained by using a cherry concentrate instead of regular. Also as a result of using the procedures of the present invention much if not most of the ingredients in cherries giving them their nutraceutical value are retained. The final heating step when carried out at temperatures below 160° F. apparently in addition to reducing the water content also destroys enzymes which adversely affect the taste of the product and thus allows the product to be more flavorful. The products of the present invention find utility as food products by themselves or in combination with other food products DETAILED DESCRIPTION OF THE INVENTION [0005] The cherries from which the dry product (leather) or semi-dry product (paste) is made should be cleaned, ripe cherries having a Brix value of at least 12. Although only Montmorency cherries have been extensively studied from a standpoint of flavor retention and shelf stability and hence are preferably used in the present invention, the process of the present invention can be equally employed with other cherry varieties. It is important to pit the cherries in such a manner as to minimize pit breakage because crushed pits are believed to release benzaldehyde, which adds an undesirable taste to the concentrate and causes problems when using a microprocessor in the further handling of the cherries. [0006] The pitted cherries should be frozen (without added sugar) and stored for at least 30 days but preferably for at least 60 days before the juice is separated from the solid. Storage of the frozen cherries improves the content of the flavor components in the final product. After the stored cherries have been thawed to a semi-frozen state generally in the range of 20 to 27° F., they are comminuted into particles of 20-80 microns using commercially available cutting machines such as a “Urschel Commitrol” microprocessor and the resulting juice is then separated at such temperatures from the comminuted mixture by such methods as centrifuging or gravity separation. In the alternative it is also possible to comminute the fresh, pitted cherries and then freeze such for storage before juice separation. [0007] The separation is conducted until about 40 to 70% of juice has been removed from the thawed, cut product to form a soft moist cherry solid. This solid is then recombined with concentrated cherry juice having a Brix value of at least 50 and preferably 65 or higher. Such concentrates can be obtained by the methods described in my co-pending application Ser. No. 10/638,890 filed Aug. 18, 2003. Concentrates having the required Brix value are also commercially available. After the concentrate has been evenly distributed in the separated solid cherry particulate through mixing it is then dried to lower the moisture content by heating at temperatures not exceeding 160° F. The heating step is necessary to deactivate enzymes contain in cherries that destroy the flavor of cherries when in contact with air. In the event a paste is the desired product the moisture content is reduced until about 45% of the original weight of the extracted mixture remains. In the event a leathery product is the desired product, the moisture is even further reduced until only about 23% of the weight of the extracted mixture is retained. [0008] Although the products of the present invention are a nutritious food product all by themselves, they find greater utility in combination with other ingredients. Thus the products can be used in cookies, in cheese, added to dry cereals and used in sauces, dressings and dips. EXAMPLE 1 [0009] 40 pounds of depitted Montmorency cherries having a Brix value of 15 were cut in a “Urschel Commitrol” microprocessor with the head having 40 blades at a temperature of about 24° F. The resulting product was bagged, frozen and stored for 60 days at freezer temperature. The frozen product was then placed on a strainer and allowed to partially thaw at room temperature. The juice was collected until about 30% of the original frozen product was retained on the strainer. The resulting wet solid, about twelve pounds, was then mixed with 3.5 pounds of concentrated cherry juice having a Brix value of 68. After mixing, the product was placed in pans in an oven at about 260° F. although the temperature at the surface of the mixed product was maintained at temperatures below 160° F. by removing the product from the oven and stirring the product. The heating step was continued until the product weighed about 7 pounds and had the consistency of a heavy paste. The product was sweet with a strong cherry flavor. [0010] A similar mixture of wet cherry solid mixed with cherry concentrate was placed into shallow pans to a depth about 0.75″ and dried at temperatures between about 110 and 140° F. When the surface appeared to be dry the product was removed from the pan and placed on a screen. The drying was continued until the weight of the mixture was reduced to about 23% of the original weight. The resulting product was a solid but chewable food product that had a sweet cherry flavor. EXAMPLE 2 [0011] 200 g of frozen depitted Montmorency cherries were cut in a Urschel Commitrol microprocessor at temperatures of about 24° F. The resulting product was then placed at a temperature of about 20° F. in the basket of a small commercially available centrifuge and extracted at about 1000 rpm until about 120 g of the original weight remained in the basket. This product was mixed with 28 g of cherry juice concentrate having a Brix of 68. The mixture was then heated at 140 to 160° F. until the remaining product weighed about 40 g. A semi-solid cherry paste was obtained that had a strong cherry flavor.

This invention relates to a semidry or dry cherry product that retains the flavor and nutraceutical ingredients of the original cherries and also has extended shelf life.

If an Application Data Sheet (ADS) has been filed on the filing date of this application, it is incorporated by reference herein. Any applications claimed on the ADS for priority under 35 U.S.C. §§119, 120, 121, or 365(c), and any and all parent, grandparent, great-grandparent, etc. applications of such applications, are also incorporated by reference, including any priority claims made in those applications and any material incorporated by reference, to the extent such subject matter is not inconsistent herewith. 1. CROSS-REFERENCE TO RELATED APPLICATIONS The present application is related to and/or claims the benefit of the earliest available effective filing date(s) from the following listed application(s) (the “Priority Applications”), if any, listed below (e.g., claims earliest available priority dates for other than provisional patent applications or claims benefits under 35 USC §119(e) for provisional patent applications, for any and all parent, grandparent, great-grandparent, etc. applications of the Priority Application(s)). In addition, the present application is related to the “Related Applications,” if any, listed below. 2. PRIORITY APPLICATIONS None 3. RELATED APPLICATIONS U.S. patent application Ser. No. 13/862,211, entitled SYSTEMS, METHODS, AND APPARATUSES RELATED TO THE USE OF GAS CLATHRATES, naming Roderick A. Hyde and Lowell L. Wood, Jr. as inventors, filed 12 Apr. 2013, is related to the present application. The United States Patent Office (USPTO) has published a notice to the effect that the USPTO's computer programs require that patent applicants reference both a serial number and indicate whether an application is a continuation, continuation-in-part, or divisional of a parent application. Stephen G. Kunin, Benefit of Prior-Filed Application, USPTO Official Gazette Mar. 18, 2003. The USPTO further has provided forms for the Application Data Sheet which allow automatic loading of bibliographic data but which require identification of each application as a continuation, continuation-in-part, or divisional of a parent application. The present Applicant Entity (hereinafter “Applicant”) has provided above a specific reference to the application(s) from which priority is being claimed as recited by statute. Applicant understands that the statute is unambiguous in its specific reference language and does not require either a serial number or any characterization, such as “continuation” or “continuation-in-part,” for claiming priority to U.S. patent applications. Notwithstanding the foregoing, Applicant understands that the USPTO's computer programs have certain data entry requirements, and hence Applicant has provided designation(s) of a relationship between the present application and its parent application(s) as set forth above and in any ADS filed in this application, but expressly points out that such designation(s) are not to be construed in any way as any type of commentary and/or admission as to whether or not the present application contains any new matter in addition to the matter of its parent application(s). If the listings of applications provided above are inconsistent with the listings provided via an ADS, it is the intent of the Applicant to claim priority to each application that appears in the Priority Applications section of the ADS and to each application that appears in the Priority Applications section of this application. All subject matter of the Priority Applications and the Related Applications and of any and all parent, grandparent, great-grandparent, etc. applications of the Priority Applications and the Related Applications, including any priority claims, is incorporated herein by reference to the extent such subject matter is not inconsistent herewith. TECHNICAL FIELD This disclosure relates generally to the use of gas clathrates. More particularly, this disclosure relates to systems, methods, and apparatuses related to the use of gas clathrates as a fuel source for automobiles. SUMMARY This disclosure provides methods of providing gaseous fuel to a prime mover of a vehicle. The methods comprise providing a vehicle fuel storage system comprising a first vessel configured to receive, store, and discharge gas clathrates. The methods further comprise providing a separation system comprising a second vessel operably connected to the vehicle fuel storage system. The separation system is configured to dissociate the gas clathrates into at least one gas and a host material. The methods further comprise discharging the gas clathrates from the first vessel to the second vessel and dissociating at least a portion of the gas clathrates into the at least one gas and the host material. The methods may further comprise delivering the at least one gas to the prime mover. This disclosure also provides vehicle fuel systems configured to utilize gas clathrates. The vehicle fuel systems comprise a vehicle fuel storage system and a separation system. The vehicle fuel storage system comprises a first vessel configured to receive, store, and discharge gas clathrates. The separation system comprises a second vessel operably connected to the vehicle fuel storage system. The separation system is configured to dissociate the gas clathrates into at least one gas and a host material. This disclosure also provides vehicles comprising one of the above vehicle fuel systems and a prime mover configured to utilize dissociated gas to generate power. The prime mover may comprise an internal combustion engine, an external combustion engine, or a fuel cell. This disclosure also provides methods of powering a vehicle. The methods comprise providing a vehicle fuel storage system comprising a first vessel configured to receive, store, and discharge gas clathrates. The methods further comprise discharging a portion of the gas clathrates from the first vessel and then generating heat from combusting the discharged gas clathrates. The methods further comprise converting the generated heat into mechanical work and utilizing the mechanical work to power the drive train of a vehicle. The combustion may be conducted in an engine configured to convert the generated heat from combustion into the mechanical work. This disclosure also provides engines configured to directly utilize gas clathrates as a fuel source. This disclosure also provides vehicles comprising such engines. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of a vehicle fuel system configured to utilize gas clathrates. FIG. 2 illustrates the embodiment of FIG. 1 with additional optional components and systems. FIG. 3 illustrates an embodiment of a vehicle configured to utilize gas clathrates as fuel source. FIG. 4 illustrates an embodiment of an engine configured to directly utilize gas clathrates as a fuel source. FIG. 5 illustrates another embodiment of an engine configured to directly utilize gas clathrates as a fuel source. FIG. 6 illustrates another embodiment of an engine configured to directly utilize gas clathrates as a fuel source. FIG. 7 illustrates another embodiment of an engine configured to directly utilize gas clathrates as a fuel source. FIG. 8 illustrates another embodiment of an engine configured to directly utilize gas clathrates as a fuel source. DETAILED DESCRIPTION Natural gas is a cleaner-burning fuel compared to traditional fossil fuels. However, natural gas at ambient temperatures and atmospheric pressure is a low-volume gas. For an automobile to store a sufficient amount of natural gas for operation comparable to that of a gasoline or diesel engine, it has been necessary to increase the density of the natural gas. One approach has been to liquify the natural gas by cooling the natural gas to about −162 degrees Centrigrade. At that temperature, natural gas is a liquid at essentially ambient pressure. Storage of liquid natural gas (“LNG”) requires the use of special cryogenic equipment. Another approach has been to compress the natural gas to a pressure of about 200 to 248 bars. At that pressure and ambient temperature, natural gas occupies about 1/100th the volume of natural gas at general ambient temperatures and pressures. Storage of compressed natural gas (“CNG”) requires the use of high-pressure storage vessels. Gas clathrates are chemical substances in which certain gas molecules are trapped in a cage or crystal lattice formed by certain host materials. In many cases, the gas molecules stabilize the crystal lattice or cage, such that the crystal lattice or cage may maintain its structure at much higher temperature and lower pressure than would be possible without the presence of the gas molecules. Methane clathrates, for example, exist in nature, among other places, under sediments on the ocean floors. Gas clathrates may be able to store gases, such as methane, at volumes comparable to CNG, but at much lower pressures and at much higher temperatures than LNG. Combustion of gas clathrates refers to dissociation of gas(es) from the clathrate host material and then combustion of the gas(es). During the process of combustion of the gas(es) the host material may also be vaporized. This vaporization does not constitute combustion. However, in some embodiments, the host material may include elements that may be combustible under certain conditions. Dissociation of gas(es) from the clathrate host material includes any process for separating the gas(es) from the clathrate host material. This includes diffusion of the gas(es) away from the solid clathrate host material and/or melting of the clathrate host material to release the gas(es). The phrases “operably connected to,” “connected to,” and “coupled to” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Likewise, “fluidically connected to” refers to any form of fluidic interaction between two or more entities. Two entities may interact with each other even though they are not in direct contact with each other. For example, two entities may interact with each other through an intermediate entity. The term “substantially” is used herein to mean almost and including 100%, including at least about 80%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, and at least about 99%. This disclosure provides methods of providing gaseous fuel to a prime mover of a vehicle. The methods comprise providing a vehicle fuel storage system comprising a first vessel configured to receive, store, and discharge gas clathrates. The methods further comprise providing a separation system comprising a second vessel operably connected to the vehicle fuel storage system. The separation system is configured to dissociate the gas clathrates into at least one gas and a host material. The methods further comprise discharging the gas clathrates from the first vessel to the second vessel and dissociating at least a portion of the gas clathrates into the at least one gas and the host material. The methods may further comprise delivering the at least one gas to the prime mover. The prime mover may be an internal combustion engine, an external combustion engine, or a fuel cell. The first vessel may be configured to discharge the gas clathrates as a slurry to the second vessel. The gas clathrates may comprise natural gas clathrates, methane clathrates, ethane clathrates, propane clathrates, and hydrogen clathrates. Accordingly, the at least one gas may comprise natural gas, methane, ethane, propane, or hydrogen. The host material may comprise water. The host material may further comprise clathrate stabilizers. Examples of clathrate stabilizer include, but are not limited to carboxylic acids and/or carboxylate containing compounds, such as lactic acid, acetic acid, the lactate ion, or the acetate ion; sodium hydroxide and/or a sodium ion; calcium hydroxide and/or a calcium ion; tetrahydrofuran; a surfactant, such as an anionic surfactant, such as alkyl sulfates or alkyl aryl sulfonates; an aphron; water soluble salts; clay; oxide particles, such as magnesium oxide particles, organic compounds, such as phenyl, phenol, alkoxyphenyl, or imidazole containing compounds. This disclosure also provides vehicle fuel systems configured to utilize gas clathrates. FIG. 1 illustrates a vehicle fuel system 100 comprising a vehicle fuel storage system 10 and a separation system 20 . The vehicle fuel storage system 10 comprises a first vessel 11 configured to receive, store, and discharge gas clathrates. The separation system 20 comprises a second vessel 21 operably connected to the vehicle fuel storage system 10 . The separation system 20 is configured to dissociate the gas clathrates into at least one gas and a host material. First vessel 11 may be configured to maintain gas clathrates as a slurry during storage or as a solid during storage. The solid gas clathrates may be one cohesive solid or may be solid pellets and/or chunks. First vessel 11 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 25 degrees Centrigrade. First vessel 11 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 20 degrees Centrigrade. First vessel 11 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 15 degrees Centrigrade. First vessel 11 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 10 degrees Centrigrade, including from about 4 degrees Centigrade to about 10 degrees Centigrade. First vessel 11 may be configured to be integrally secured to the frame of a vehicle. First vessel 11 may be configured to be directly or indirectly detachably secured to the frame of a vehicle, such as via a mechanical and/or magnetic device. First vessel 11 may be configured to be detachably connected to the fuel supply lines that feed the prime mover of a vehicle. Second vessel 21 may be configured to operate at ambient temperature and/or at any temperature that is higher than the operating temperature of the first vessel 11 . Alternatively, second vessel 21 may be configured to operate at a temperature that is about the same as an operating temperature of the first vessel, but at a lower pressure than that of first vessel 11 . For example, second vessel 21 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 25 degrees Centrigrade. Second vessel 21 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 20 degrees Centrigrade. Second vessel 21 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 15 degrees Centrigrade. Second vessel 21 may be configured to maintain an internal temperature of about 0 degrees Centigrade to about 10 degrees Centrigrade, including from about 4 degrees Centigrade to about 10 degrees Centigrade. First vessel 11 and second vessel 21 may each further comprise insulation. The insulation may comprise at least one material configured to and compatible with maintaining desired temperatures within each vessel. Examples of such materials include, but are not limited to, calcium silicate, cellular glass, elastomeric foam, fiberglass, polyisocyanurate, polystyrene, and polyurethane. The insulation may comprise at least one vacuum layer and/or multi-layer insulation. The insulation may releasably surround at least a portion of an outer surface of the first vessel 11 and/or the insulation may be attached to at least a portion of a surface of the first vessel 11 , including an outer and/or inner surface. The insulation may be attached to at least a portion of a surface of the second vessel 21 , including an outer and/or inner surface. First vessel 11 and second vessel 21 may each be comprised of structural materials configured to and compatible with maintaining desired temperatures and pressures within each respective vessel. The structural material may comprise aluminum, brass, copper, ferretic steel, carbon steel, stainless steel, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), vinylidene polyfluoride (PVDF), polyamide (PA), polypropylene (PP), nitrile rubber (NBR), chloroprene (CR), chlorofluorocarbons (FKM), and/or composite materials, including composite materials comprising carbon fibers, glass fibers, and/or aramid fibers. First vessel 11 may be designed to maintain an internal pressure of about 1 bar to about 30 bar. First vessel 11 may be designed to maintain an internal pressure of about 10 bar to about 30 bar. First vessel 11 may be designed to maintain an internal pressure of about 10 bar to about 15 bar. First vessel 11 may be designed to maintain an internal pressure of about 15 bar to about 27 bar. First vessel 11 may be designed to maintain an internal pressure of about 20 bar to about 27 bar. First vessel 11 may be designed to leak or vent before burst. First vessel 11 may be configured to receive gas clathrates as a solid and/or as a slurry. Alternatively, first vessel 11 may be configured to receive at least one gas and the host material and form the gas clathrates within the first vessel 11 . Separation system 20 may be configured to maintain a lower pressure in the second vessel 21 than the pressure maintained in the first vessel 11 . Additionally or alternatively, separation system 20 may be configured to maintain a pressure in the second vessel 21 sufficient to dissociate at least some of the gas clathrates into at least one gas and host material, but still maintain a pressure greater than the pressure required for delivering the at least one gas as fuel to a prime mover utilizing the vehicle fuel system 100 . Separation system 20 may be configured to maintain an internal pressure in the second vessel of about ambient pressure to about 30 bar. Separation system 20 may be configured to maintain an internal pressure in the second vessel of about 5 bar to about 20 bar. Separation system 20 may be configured to maintain an internal pressure in the second vessel of about 10 bar to about 15 bar. Separation system 20 may be configured to maintain an internal pressure in the second vessel of about ambient pressure to about 10 bar. Separation system 20 may be configured to maintain an internal pressure in the second vessel of about ambient pressure. Second vessel 21 may be designed to leak or vent before burst. FIG. 2 illustrates optional additional components and systems of vehicle fuel system 100 . Vehicle fuel storage system 10 may further comprise a first refrigeration system 12 in communication with first vessel 11 . First refrigeration system 12 may be configured to maintain an internal temperature of the first vessel 11 within a desired set range. First refrigeration system 12 may releasably surround at least a portion of the outer surface of the first vessel 11 . Alternatively, the first refrigeration system 12 may be attached to at least a portion of a surface of the first vessel 11 , including an outer and/or an inner surface. First refrigeration system 12 may comprise a heat pipe. First refrigeration system 12 may comprise a vapor compression system. The vapor compression system may utilize a chlorofluorocarbon, a chlorofluoroolefin, a hydrochlorofluorocarbon, a hydrochloro-fluoroolefin, a hydrofluoroolefin, a hydrochloroolefin, a hydroolefin, a hydrocarbon, a perfluoroolefin, a perfluorocarbon, a perchloroolefin, a perchlorocarbon, and/or a halon. First refrigeration system 12 may comprise a vapor absorption system. The vapor absorption system may utilize water, ammonia, and/or lithium bromide. First refrigeration system 12 may comprise a gas cycle refrigeration system, such as one that utilizes air. First refrigeration system 12 may comprise a stirling cycle refrigeration system. The stirling cycle refrigeration system may utilize helium. The stirling cycle refrigeration system may comprise a free piston stirling cooler. First refrigeration system 12 may comprise a thermoelectric refrigeration system. Vehicle fuel storage system 10 may further comprise a first pressurizing device 13 operably connected to the first vessel 11 and configured to maintain pressure within the first vessel 11 . First pressurizing device 13 may comprise a moveable press integrated with the first vessel 11 , wherein the moveable press is configured to maintain pressure within the first vessel 11 . Examples of a moveable press include, but are not limited to, a hydraulic press. First pressurizing device 13 may comprise a compressor. Examples of a compressor include, but are not limited to, a centrifugal compressor, a mixed-flow compressor, an axial-flow compressor, a reciprocating compressor, a rotary screw compressor, a rotary vane compressor, a scroll compressor, and a diaphragm compressor. Vehicle fuel storage system 10 may further comprise a first pressure monitoring device 14 operably connected to the first vessel 11 and configured to monitor the internal pressure of the first vessel 11 . First pressure monitoring device 14 may comprises a piezoresistive strain gauge, a capacitive sensor, an electromagnetic sensor, a piezoelectric sensor, an optical sensor, a potentiometric sensor, a thermal conductivity sensor, and/or an ionization sensor. Vehicle fuel storage system 10 may further comprise a first heating system 15 configured and located to impart heat energy to the first vessel 11 . First heating system 15 may be configured to transfer heat energy from the coolant used to cool the prime mover of the vehicle. Likewise, first heating system 15 may be configured to transfer heat energy from heat generated by the prime mover of the vehicle in any fashion, such as from an exhaust stream generated by the prime mover of the vehicle. Alternatively or in addition thereto, first heating system 15 may utilize solar energy, ambient temperatures, electric resistance heating elements and/or dielectric heating to impart heat energy to the first vessel 11 . First heating system 15 may be located external to the first vessel 11 . First heating system 15 may be located internally within the first vessel 11 . First heating system 15 may be integrated into a portion of a surface of the first vessel 11 , including external or internal surfaces. First heating system 15 may be attached to at least a portion of a surface of the first vessel 11 , such as the outer surface. Vehicle fuel storage system 10 may further comprise a first temperature monitoring system 16 configured to monitor the internal temperature of the first vessel 11 . First temperature monitoring system 16 may comprise a thermostat, a thermistor, a thermocouple, and/or a resistive temperature detector. Vehicle fuel storage system 10 may further comprise a first pressure relief device 17 operably connected to the first vessel 11 and configured to reduce pressure within the first vessel 11 . Examples of a first pressure relief device 17 include, but are not limited to, a pressure relief valve and a rupture disc. Vehicle fuel storage system 10 may further comprise a first emergency cooling system 18 configured to rapidly cool the first vessel 11 . Vehicle fuel storage system 10 may further comprise a cooling control system configured to receive inputs from first pressure monitoring device 14 and/or first temperature monitoring system 16 . The cooling control system may be configured to control first pressurizing device 13 and/or first heating system 15 , such that it regulates at least one of pressure and temperature in order to maintain the gas clathrates within first vessel 11 in a clathrate stability range. Separation system 20 may further comprise a second refrigeration system 22 in communication with second vessel 21 . Second refrigeration system 22 may be configured to maintain an internal temperature of the second vessel 21 within a desired set range. Second refrigeration system 22 may be attached to at least a portion of a surface of the second vessel 21 , including an outer and/or an inner surface. Second refrigeration system 22 may comprise a vapor compression system. The vapor compression system may utilize a chlorofluorocarbon, a chlorofluoroolefin, a hydrochlorofluorocarbon, a hydrochloro-fluoroolefin, a hydrofluoroolefin, a hydrochloroolefin, a hydroolefin, a hydrocarbon, a perfluoroolefin, a perfluorocarbon, a perchloroolefin, a perchlorocarbon, and/or a halon. Second refrigeration system 22 may comprise a vapor absorption system. The vapor absorption system may utilize water, ammonia, and/or lithium bromide. Second refrigeration system 22 may comprise a gas cycle refrigeration system, such as one that utilizes air. Second refrigeration system 22 may comprise a stirling cycle refrigeration system. The stirling cycle refrigeration system may utilize helium. The stirling cycle refrigeration system may comprise a free piston stirling cooler. Second refrigeration system 22 may comprise a thermoelectric refrigeration system. Separation system 20 may further comprise second pressurizing device 23 operably connected to the second vessel 21 and configured to maintain pressure within the second vessel 21 . Second pressurizing device 23 may comprise a moveable press integrated with the second vessel 21 , wherein the moveable press is configured to maintain pressure within the second vessel 21 . Examples of a moveable press include, but are not limited to, a hydraulic press. Second pressurizing device 23 may comprise a compressor. Examples of a compressor include, but are not limited to, a centrifugal compressor, a mixed-flow compressor, an axial-flow compressor, a reciprocating compressor, a rotary screw compressor, a rotary vane compressor, a scroll compressor, and a diaphragm compressor. Separation system 20 may further comprise a second pressure monitoring device 24 operably connected to the second vessel 21 and configured to monitor the internal pressure of the second vessel 21 . Second pressure monitoring device 24 may comprises a piezoresistive strain gauge, a capacitive sensor, an electromagnetic sensor, a piezoelectric sensor, an optical sensor, a potentiometric sensor, a thermal conductivity sensor, and/or an ionization sensor. Separation system 20 may further comprise a second heating system 25 configured and located to impart heat energy to the second vessel 21 . Second heating system 25 may be configured to transfer heat energy from the coolant used to cool the prime mover of the vehicle. Likewise, second heating system 25 may be configured to transfer heat energy from heat generated by the prime mover of the vehicle in any fashion, such as from an exhaust stream generated by the prime mover of the vehicle. Alternatively or in addition thereto, second heating system 25 may utilize solar energy, ambient temperatures, electric resistance heating elements and/or dielectric heating to impart heat energy to the second vessel 21 . Second heating system 25 may be located external to the second vessel 21 . Second heating system 25 may be located internally within the second vessel 21 . Second heating system 25 may be integrated into a portion of a surface of the second vessel 21 , including external or internal surfaces. Second heating system 25 may be attached to at least a portion of a surface of the second vessel 21 , such as the outer surface. Separation system 20 may further comprise a heat pipe, either as part of second refrigeration system 22 and/or second heating system 25 or separate therefrom. The heat pipe may be configured and located to control the temperature of the second vessel 21 . Separation system 20 may further comprise a second temperature monitoring system 26 configured to monitor the internal temperature of the second vessel 21 . Second temperature monitoring system 26 may comprise a thermostat, a thermistor, a thermocouple, and/or a resistive temperature detector. Separation system 20 may further comprise a second pressure relief device 27 operably connected to the second vessel 21 and configured to reduce pressure within the second vessel 21 . Examples of a second pressure relief device 27 include, but are not limited to, a pressure relief valve and a rupture disc. Separation system 20 may further comprise a second emergency cooling system 28 configured to rapidly cool the second vessel 21 . Separation system 20 may further comprise a pressure reducing valve operably connected to the first vessel 11 and the second vessel 21 , wherein the pressure reducing valve is configured to reduce the pressure of gas clathrates discharged from the first vessel 11 to the desired pressure of the second vessel 21 . Separation system 20 may be configured to receive a continuous supply of gas clathrates while a vehicle utilizing vehicle fuel system 100 is operating. Alternatively, separation system 20 may be configured to periodically receive a batch of gas clathrates while a vehicle utilizing vehicle fuel system 100 is operating. Furthermore, separation system 20 may be configured to receive a variable supply of gas clathrates based on fuel requirements of the prime mover of the vehicle utilizing the vehicle fuel system 100 . Separation system 20 may be configured to control the rate of dissociation of the gas clathrates based on fuel requirements of the prime mover of the vehicle utilizing the vehicle fuel system 100 , such as by regulating at least one of the temperature and the pressure of the gas clathrates within the second vessel 21 . Second vessel 21 may comprises a chamber configured to dissociate the gas clathrates into at least one gas and host material. Alternatively or in addition thereto, second vessel 21 may comprises a conduit configured to continuously dissociate the gas clathrates into at least one gas and host material. Second vessel 21 may comprise a host material outlet configured for removing the host material from the second vessel 21 . The host material outlet may be configured to periodically or continuously drain the host material from the second vessel 21 and remove the host material from the vehicle fuel system 100 . The host material outlet may be configured to release the host material to an environment outside of a vehicle utilizing vehicle fuel system 100 . Vehicle fuel system 100 may further comprise a first transport device 39 operably connected to the vehicle fuel storage system 10 and operably connected to the separation system 20 . The first transport device 39 may be configured to transfer gas clathrates from the vehicle fuel storage system 10 to the separation system 20 . First transport device 39 may be configured to transport the gas clathrates as a slurry and/or as a solid, such as solid chunks or pellets. First transport device 39 may be at least partially located internally within the first vessel 11 . Likewise, the first transport device 39 may be at least partially external to the first vessel 11 . Accordingly, first transport device 39 may be at least partially integrated into a portion of a surface, including an internal or external surface, of the first vessel 11 . Additionally, the first transport device 39 may be at least partially integrated into a portion of a surface, including an internal or external surface, of the second vessel 21 . Likewise, first transport device 39 may be at least partially internal and/or external to the second vessel 21 . First transport device 39 may be configured for moving solid gas clathrate. First transport device 39 may be configured for moving gas clathrate slurry. First transport device 39 may be configured to be hydraulically, mechanically, and/or electrically actuated. First transport device 39 may comprise an auger, a grinder, an extruder, and/or a first pump. When first transport device 39 comprises a first pump, the inlet of the first pump may be operably connected to the vehicle fuel storage system 10 and an outlet of the first pump may be operably connected to the separation system 20 . Examples of the first pump include, but are not limited to, a positive displacement pump, a lobe pump, an external gear pump, an internal gear pump, a peristaltic pump, a screw pump, a progressive cavity pump, a flexible impeller pump, a rotary vane pump, and a centrifugal pump. The first pump may be any pump compatible with pumping a gas clathrate slurry. First transport device 39 may comprise a gravity feed device for use in embodiments where a portion of the first vessel 11 is higher than a portion of the second vessel 21 . The gravity feed device may comprise a port, a tube, a pipe, a channel, a valve, a check valve, or similar feed conduits. First transport device 39 may comprise a conduit (such as a port a tube, a pipe, a valve, a check valve, or a channel) in embodiments where the pressure in first vessel 11 is higher than the pressure in second vessel 21 . First transport device 39 may comprise a moveable surface. The moveable surface may comprise a conveyor belt configured to receive a coating of the gas clathrates from the vehicle fuel storage system 10 and configured to at least partially discharge at least one gas within the second vessel 21 . For example, the moveable surface may comprise a rotating drum configured to receive a coating of the gas clathrates within first vessel 11 and at least partially discharge at least one gas within the second vessel 11 . In another example, the moveable surface may comprise a string configured with beads of gas clathrates that may be conveyed from the first vessel 11 to the second vessel 21 . In another example, the moveable surface may comprise a rotating disk configured to receive a coating of the gas clathrates within first vessel 11 and at least partially discharge at least one gas within the second vessel 11 . Vehicle fuel system 100 may further comprise a recycle system 40 configured to return host material from separation system 20 to vehicle fuel storage system 10 . Accordingly, vehicle fuel storage system 10 may be configured to utilize at least a portion of the returned host material to fluidize the gas clathrates stored in the first vessel 11 . The recycle system 40 may comprises a third vessel 41 configured to store host material removed from second vessel 21 . The recycle system 40 may further comprise a second transport device 49 configured to transport host material from the second vessel 21 to the third vessel 41 . Alternatively, second transport device 49 may be configured to transport host material from the second vessel 21 directly to the first vessel 11 . Second transport device 49 may be configured to transport the host material as a slurry or as a liquid. The second transport device 49 may be located internally within the second vessel 21 , may be integrated into a portion of a surface, including an internal or external surface, of the second vessel 21 , or may be external to the second vessel 21 . Second transport device 49 may be configured to be hydraulically, mechanically, and/or electrically actuated. Second transport device 49 may comprise a gravity feed device for use in embodiments where a portion of the second vessel 21 is higher than a portion of the first vessel 11 . The gravity feed device may comprise a port, a pipe, a channel, a valve, a check valve, or similar feed conduits. The second transport device 49 may comprise an auger, grinder, and/or second pump. When second transport device 49 comprises a second pump, the inlet of the second pump may be operably connected to the separation system 20 and an outlet of the second pump may be operably connected to vehicle fuel storage system 10 . Examples of the second pump include, but are not limited to, a positive displacement pump, a lobe pump, an external gear pump, an internal gear pump, a peristaltic pump, a screw pump, a progressive cavity pump, a flexible impeller pump, a rotary vane pump, and a centrifugal pump. The second pump may be any pump compatible with pumping liquid or slurry host material. Alternatively or in addition to recycle system 40 , second vessel 21 may be configured to temporarily store at least a portion of dissociated host material. The vehicle fuel system 100 may further comprise delivery system 50 configured to deliver gas dissociated from gas clathrates within first vessel 11 and second vessel 21 to the prime mover of a vehicle utilizing vehicle fuel system 100 . Delivery system 50 may comprise a gas storage vessel 51 configured to store dissociated gas removed from the second vessel 21 . Second vessel 21 may comprise a gas outlet configured for removing dissociated at least one gas from the second vessel 21 . The gas storage vessel 51 may be operably connected to the gas outlet of second vessel 21 and operably connected to the prime mover. Delivery system 50 may further comprise a metering system 52 configured to control introduction of stored gas to the prime mover. Metering system 52 may comprise a control valve operably connected to the gas storage vessel 51 and to the prime mover. The control valve may be configured to control release of stored gas from the gas storage vessel 51 . Metering system 52 may further comprise a gas flow meter configured to measure the flow rate of the stored gas released from the gas storage vessel 51 . Delivery system 50 may comprise a third transport device 59 configured to transport gas from the separation system to the prime mover of a vehicle. The third transport device may be configured to control the transport of the gas based on the fuel requirements of the prime mover. The third transport device 59 may comprise a compressor. Examples of a compressor include, but are not limited to, a centrifugal compressor, a mixed-flow compressor, an axial-flow compressor, a reciprocating compressor, a rotary screw compressor, a rotary vane compressor, a scroll compressor, and a diaphragm compressor. Third transport device 59 may increase the temperature of the gas transported thereby, such as when the gas is compressed. Accordingly, delivery system 50 may further comprise a cooling device 53 configured to reduce the temperature of dissociated at least one gas prior to introduction of the gas into the prime mover. Cooling device 53 may comprise a heat exchanger configured to be cooled by ambient air, such as a heat exchanger comprising cooling fins. Cooling device 53 may comprise a heat exchanger configured to be cooled by a coolant also used to cool the prime mover. Cooling device 53 may comprise a heat exchanger configured to impart heat to the second vessel 21 to cool the heat exchanger. In such embodiments, cooling device 53 may be at least partially integrated into a surface, including an internal or external surface, of the second vessel 21 . Cooling device 53 may comprise a heat exchanger configured to be cooled by dissociated host material. Cooling device 53 may comprise a heat exchanger configured to be cooled by gas clathrates either stored by first vessel 11 or being transported by first transport device 39 . For example, the heat exchanger may be at least partially integrated with the first transport device 39 . Cooling device 53 may comprise a refrigerated coil configured to cool the dissociated at least one gas. Dissociated gas may comprise more water vapor than can be tolerated by the prime mover of a vehicle utilizing vehicle fuel system 100 . Therefore, delivery system 50 may further comprise a moisture-removal system 54 configured to remove water from dissociated gas. Moisture-removal system 54 may comprise a dehumidifier, a dryer, and/or a molecular sieve column. Moisture-removal system 54 may be integrated internally within the second vessel 21 or may be located external to the second vessel 21 . Moisture-removal system 54 may be integrated into a portion of a surface, including an internal or external surface, of the second vessel 21 . Gas storage vessel 51 , metering system 52 , cooling device 53 , moisture-removal system 54 , and third transport device 59 of delivery system 50 may be combined in any order. Additionally, any or all of the components of delivery system 50 may not be present. In some embodiments, a portion of the gas clathrates stored in first vessel 11 will dissociate within first vessel 11 . Additionally, gas may be stored in first vessel 11 that never associated into clathrates with host material. In such embodiments, the first vessel 11 comprises a gas outlet configured and located for removing gas from the first vessel 11 . The gas outlet of the first vessel 11 may be operably connected to gas storage vessel 51 . Alternatively, the gas outlet of the first vessel 11 may be operably connected to the second vessel 21 and any gas present in first vessel 11 conveyed to second vessel 21 . In some embodiments, the first vessel 11 may be configured to be readily and easily removed from a vehicle and configured to be readily and easily reattached to a vehicle. In such embodiments, second vessel 21 may not be present, but instead the functionality of separation system 20 may be integrated with vehicle fuel storage system 10 , such that the gas clathrates are dissociated within first vessel 11 . In some embodiments, the first vessel 11 may be configured to facilitate gas clathrate formation by agitating the gas and host material. First vessel 11 may be configured to agitate the gas and host material at a first temperature and a first pressure compatible with forming the gas clathrates. First vessel 11 may comprise a mixing element located within the first vessel 11 that is configured to agitate the gas and host material. First vessel 11 may further be configured to agitate formed gas clathrates at a second temperature and a second pressure compatible with dissociating the gas clathrates back into the gas and host material for delivery to the prime mover of a vehicle. In such embodiments, second vessel 21 may not be present, but instead the functionality of separation system 20 may be integrated with vehicle fuel storage system 10 . This disclosure also provides a vehicle comprising the vehicle fuel system 100 and a prime mover configured to utilize dissociated gas to generate power. The prime mover may comprise an internal combustion engine, an external combustion engine, or a fuel cell. In some embodiments, the exhaust stream of the prime mover is condensed to transfer heat energy to the second vessel 21 . This disclosure also provides a method of powering a vehicle, where the method comprises providing a vehicle fuel storage system comprising a first vessel configured to receive, store, and discharge gas clathrates. The method further comprises discharging a portion of the gas clathrates from the first vessel and then generating heat from combusting the discharged gas clathrates. The method further comprises converting the generated heat into mechanical work and utilizing the mechanical work to power the drive train of a vehicle. The combustion may be conducted in an engine configured to convert the generated heat from combustion into the mechanical work. This disclosure also provides a vehicle comprising an engine configured to directly utilize gas clathrates as a fuel source. FIG. 3 illustrates a vehicle 200 comprising a vehicle fuel storage system 110 comprising a first vessel 111 configured to receive, store, and discharge gas clathrates. Vehicle 200 further comprises an engine 160 configured to directly utilize gas clathrates as a fuel source. Engine 160 may be configured to receive gas clathrates as a solid, such as in chunks, pellets, flakes, and/or pulverized particles, and/or as a slurry. Engine 160 may comprise an internal or external combustion engine. Engine 160 may be configured to recover energy due to recondensation of vaporized clathrate host material. The energy may be recovered within an exhaust system of engine 160 or within a cylinder of engine 160 . Engine 160 may be configured to supply at least a portion of the thermal energy recovered from the engine 160 to the first vessel 111 . Engine 160 may comprise a two-stroke engine. Engine 160 may comprise a four-stroke engine. For example, the four-stroke engine may comprise pistons configured for reciprocation or may comprises a pistonless rotary engine. The four-stroke engine may comprise an injector configured to spray liquified gas clathrates into a combustion chamber of the four-stroke engine. The gas clathrates may be liquified either before introduction to the injector or may be liquified within the injector. Engine 160 may also comprise a six-stroke engine. Engine 160 may also comprise any of the engines discussed below regarding FIGS. 4-8 . FIG. 4 illustrates an engine 300 configured to directly utilize gas clathrates as a fuel source. Engine 300 is a two-stroke engine. Engine 300 comprises an intake port 310 configured to receive gas clathrates. Engine 300 further comprises a crankcase 320 in fluidic communication with the intake port 310 . Crankcase 320 is operably sized and configured to receive the gas clathrates in sequence with rotation of a crankshaft 325 rotatably engaged within the crankcase 320 . Crankcase 320 is configured to dissociate the gas clathrates into at least one gas and host material within crankcase 320 . Engine 300 further comprises a combustion chamber 330 in fluidic communication with the crankcase 320 and configured to combust the at least one gas dissociated within crankcase 320 . Engine 300 further comprises a piston 340 slidably engaged within the combustion chamber 330 and operably connected to the crankshaft 325 . Engine 300 further comprises an exhaust port 350 operably connected to the combustion chamber 330 and configured to remove combustion products from the combustion chamber 330 in sequence with movement of the piston 340 . Crankcase 320 may be further configured to at least partially vaporize the host material, such that the vaporized host material is transported with the dissociated gas into the combustion chamber 330 . Combustion chamber 33 and/or the exhaust port 350 may be configured to remove vaporized host material from the combustion chamber 330 , including any host material that may have recondensed within combustion chamber 330 . Engine 300 may be configured to transfer at least a portion of heat energy from the exhaust stream of the engine 300 to the crankcase 320 . For example, engine 300 may comprise a heat exchanger operably connected with the exhaust port 350 and operably connected with at least a portion of a surface, such as an external surface, of the crankcase 320 . The heat exchanger may be configured to transfer at least a portion of the heat energy from the exhaust stream to the surface of the crankcase 320 . The intake port 310 may also be configured to receive an oxygen supply in addition to receiving gas clathrates. The oxygen supply may comprise air and/or pure oxygen. Alternatively, or in addition thereto, engine 300 may further comprise a second intake port configured to receive the oxygen supply, but not the gas clathrates. The second intake port may be configured for fluidic communication with the crankcase 320 . Engine 300 may further comprise an oil reservoir and oil pump located external to the crankcase 320 and configured to provide lubricating oil to moving parts within the crankcase 320 and the combustion chamber 330 . Engine 300 may be configured to combust the lubricating oil. Any variation of a two-stroke engine that is known in the art and is compatible with direct utilization of gas clathrates as fuel may be used. For example, intake port 310 may be configured and located for piston control of engine 300 . In another example, engine 300 may further comprise a reed inlet valve configured for fluidic communication with the intake port 310 . For example, engine 300 may comprise a bourke engine. In other examples, engine 300 may be configured for cross-flow scavenging, loop scavenging, or uni-flow scavenging. Engine 300 may further comprise an exhaust port timing valve in fluidic communication with the exhaust port 350 . Engine 300 may further comprise a valve in fluidic communication with the exhaust port 350 , where the valve is configured to alter the volume of combustion products removed via the exhaust port 350 . The combustion chamber 330 may comprise a cylinder configured for operable connection with the piston 330 , wherein the piston 330 is located within the cylinder. Engine 300 may be configured to transfer at least a portion of the heat energy from the cylinder to the crankcase 320 . FIG. 5 illustrates an engine 400 configured to directly utilize gas clathrates as a fuel source. Engine 400 is an alpha configuration stirling engine. Engine 400 comprises a hot cylinder 410 and a first piston 420 slidably engaged within the hot cylinder 410 . Engine 400 further comprises a flywheel 430 operably connected to the first piston 420 . Engine 400 further comprises a cool cylinder 440 and a second piston 450 slidably engaged within the cool cylinder 440 . The second piston 450 is operably connected to the flywheel 430 . Engine 400 further comprises a regenerator 460 configured to fluidically connect a working fluid within the hot cylinder 410 and the cool cylinder 440 and configured to transfer heat to and from the working fluid as the fluids is shuttled back and forth between hot cylinder 410 and cool cylinder 440 . Engine 400 further comprises a combustion chamber 470 configured to combust the gas clathrates and supply heat to the hot cylinder 410 . Combustion chamber 470 may be operably connected to a vehicle fuel storage system, such as vehicle fuel storage system 110 of FIG. 3 . Any variation of an alpha configuration stirling engine that is known in the art and is compatible with direct utilization of gas clathrates as fuel may be used. For example, cool cylinder 440 may be configured with cooling fins designed to radiate heat away from the cool cylinder 440 and/or cool cylinder 440 may be configured for liquid cooling. In another example, at least a portion of the hot cylinder 410 may be located within the combustion chamber 470 . In yet another example, engine 400 may be configured to utilize heat energy from the exhaust stream from the combustion chamber 470 to heat at least a portion of the hot cylinder 410 . Likewise, any working fluid known in the art for a stirling engine may be used, such as, by way on non-limiting example, air, hydrogen, helium, and/or nitrogen. Engine 400 may be configured to further utilize heat energy from the exhaust stream from the combustion chamber 470 to impart heat to the gas clathrate storage vessel, such as the first vessel 111 of FIG. 3 . Combustion chamber 470 may be configured to substantially vaporize any host material dissociated from the gas clathrates. Combustion chamber 470 , or some other components of engine 400 , may be configured to substantially recondense any vaporized host material dissociated from the gas clathrates. Combustion chamber 470 may be configured to melt, but not vaporize, at least a portion of the host material. Combustion chamber 470 may be configured to utilize pulverized gas clathrate solids blown into the combustion chamber 470 . Combustion chamber 470 may be configured to utilize solid gas clathrate chunks, pellets, and/or flakes. Combustion chamber 470 may be configured to utilize gas clathrates as a slurry. Combustion chamber 470 may comprises a grate configured to hold the gas clathrates during combustion of dissociated gas. The grate may be configured to allow liquid host material to drip through the grate. The liquid host material may collect below the grate. The grate may be configured to be stationary. Alternatively, the grate may be configured to rotate at least partially within the combustion chamber 470 . Combustion chamber 470 may be operably connected to a stoker configured to feed gas clathrate solids onto at least a portion of the grate. Combustion chamber 470 may comprise an outlet configured to remove collected host material from the combustion chamber 470 . Engine 400 may further comprise a drain system fluidically connected to the outlet. The drain system may be configured to release the collected host material to the environment. Alternatively, the drain system may be fluidically connected to a host material storage tank configured to store the collected host material. Engine 400 may further comprise a cooling system fluidically connected to the outlet and configured to use the collected host material to cool the cool cylinder 440 . Engine 400 may further comprise an oxygen supply device operably connected to the combustion chamber 470 and configured to supply oxygen to the combustion chamber 470 . The oxygen supply device may be configured to supply air to the combustion chamber 470 , such as by blowing atmospheric air into the combustion chamber 470 . Alternatively or in addition thereto, the oxygen supply device may comprise an oxygen tank and may be configured to provide pressurized oxygen to the combustion chamber 470 . FIG. 6 illustrates an engine 500 configured to directly utilize gas clathrates as a fuel source. Engine 500 is a beta configuration stirling engine. Engine 500 comprises a cylinder 505 comprising a hot end 510 configured to transfer heat during operation to a working fluid within the cylinder 505 and comprising a cool end 540 configured to remove heat from the working fluid. Engine 500 further comprises a displacer piston 520 slidably engaged within the cylinder 505 and configured to move the working fluid back and forth between the hot end 510 and the cold end 540 during operation. The displacer piston 520 is operably connected to a flywheel 530 . Engine 500 further comprises a working piston 550 slidably engaged within the cylinder 505 and operably connected to the flywheel 530 . Engine 500 further comprises a combustion chamber 570 configured to combust the gas clathrates and supply heat to the hot end 510 . Combustion chamber 570 may be operably connected to a vehicle fuel storage system, such as vehicle fuel storage system 110 of FIG. 3 . Any variation of a beta configuration stirling engine that is known in the art and is compatible with direct utilization of gas clathrates as fuel may be used. For example, engine 500 may comprise a regenerator fluidically connected to the hot end 510 and to the cool end 540 of the cylinder 505 . The regenerator may be configured to transfer heat to and from the working fluid within the cylinder 505 . In another example, cool end 540 may be configured with cooling fins designed to radiate heat away from the cool end 540 and/or cool cylinder 540 may be configured for liquid cooling. In another example, at least a portion of the hot end 510 may be located within the combustion chamber 570 . In yet another example, engine 500 may be configured to utilize heat energy from the exhaust stream from the combustion chamber 570 to heat at least a portion of the hot end 510 . Likewise, any working fluid known in the art for a stirling engine may be used, such as, by way on non-limiting example, air, hydrogen, helium, and/or nitrogen. Engine 500 may be configured to further utilize heat energy from the exhaust stream from the combustion chamber 570 to impart heat to the gas clathrate storage vessel, such as the first vessel 111 of FIG. 3 . Combustion chamber 570 may be configured to substantially vaporize any host material dissociated from the gas clathrates. Combustion chamber 570 , or some other components of engine 500 , may be configured to substantially recondense any vaporized host material dissociated from the gas clathrates. Combustion chamber 570 may be configured to melt, but not vaporize, at least a portion of the host material. Combustion chamber 570 may be configured to utilize pulverized gas clathrate solids blown into the combustion chamber 570 . Combustion chamber 570 may be configured to utilize solid gas clathrate chunks, pellets, and/or flakes. Combustion chamber 570 may be configured to utilize gas clathrates as a slurry. Combustion chamber 570 may comprises a grate configured to hold the gas clathrates during combustion of dissociated gas. The grate may be configured to allow liquid host material to drip through the grate. The liquid host material may collect below the grate. The grate may be configured to be stationary. Alternatively, the grate may be configured to rotate at least partially within the combustion chamber 570 . Combustion chamber 570 may be operably connected to a stoker configured to feed gas clathrate solids onto at least a portion of the grate. Combustion chamber 570 may comprise an outlet configured to remove collected host material from the combustion chamber 570 . Engine 500 may further comprise a drain system fluidically connected to the outlet. The drain system may be configured to release the collected host material to the environment. Alternatively, the drain system may be fluidically connected to a host material storage tank configured to store the collected host material. Engine 500 may further comprise a cooling system fluidically connected to the outlet and configured to use the collected host material to cool the cool end 540 . Engine 500 may further comprise an oxygen supply device operably connected to the combustion chamber 570 and configured to supply oxygen to the combustion chamber 570 . The oxygen supply device may be configured to supply air to the combustion chamber 570 , such as by blowing atmospheric air into the combustion chamber 570 . Alternatively or in addition thereto, the oxygen supply device may comprise an oxygen tank and may be configured to provide pressurized oxygen to the combustion chamber 570 . FIG. 7 illustrates an engine 600 configured to directly utilize gas clathrates as a fuel source. Engine 600 is a gamma configuration stirling engine. Engine 600 comprises a hot cylinder 610 and a displacer piston 620 slidably engaged within the hot cylinder 610 . The displacer piston is operably connected to a flywheel 630 . Engine 600 further comprises a cool cylinder 640 and a second piston 650 slidably engaged within the cool cylinder 640 . The second piston is operably connected to the flywheel 630 . Engine 600 further comprises a combustion chamber 670 configured to combust the gas clathrates and supply heat to the hot cylinder 610 . Combustion chamber 670 may be operably connected to a vehicle fuel storage system, such as vehicle fuel storage system 110 of FIG. 3 . Any variation of a gamma configuration stirling engine that is known in the art and is compatible with direct utilization of gas clathrates as fuel may be used. For example, engine 600 may comprise a regenerator fluidically connected to the hot cylinder 610 and to the cool cylinder 640 . The regenerator may be configured to transfer heat to and from the working fluid within hot cylinder 610 and cool cylinder 640 . In another example, cool cylinder 640 may be configured with cooling fins designed to radiate heat away from the cool cylinder 640 and/or cool cylinder 640 may be configured for liquid cooling. In another example, at least a portion of the hot cylinder 610 may be located within the combustion chamber 670 . In yet another example, engine 600 may be configured to utilize heat energy from the exhaust stream from the combustion chamber 670 to heat at least a portion of the hot cylinder 610 . Likewise, any working fluid known in the art for a stirling engine may be used, such as, by way on non-limiting example, air, hydrogen, helium, and/or nitrogen. Engine 600 may be configured to further utilize heat energy from the exhaust stream from the combustion chamber 670 to impart heat to the gas clathrate storage vessel, such as the first vessel 111 of FIG. 3 . Combustion chamber 670 may be configured to substantially vaporize any host material dissociated from the gas clathrates. Combustion chamber 670 , or some other components of engine 600 , may be configured to substantially recondense any vaporized host material dissociated from the gas clathrates. Combustion chamber 670 may be configured to melt, but not vaporize, at least a portion of the host material. Combustion chamber 670 may be configured to utilize pulverized gas clathrate solids blown into the combustion chamber 670 . Combustion chamber 670 may be configured to utilize solid gas clathrate chunks, pellets, and/or flakes. Combustion chamber 670 may be configured to utilize gas clathrates as a slurry. Combustion chamber 670 may comprises a grate configured to hold the gas clathrates during combustion of dissociated gas. The grate may be configured to allow liquid host material to drip through the grate. The liquid host material may collect below the grate. The grate may be configured to be stationary. Alternatively, the grate may be configured to rotate at least partially within the combustion chamber 670 . Combustion chamber 670 may be operably connected to a stoker configured to feed gas clathrate solids onto at least a portion of the grate. Combustion chamber 670 may comprise an outlet configured to remove collected host material from the combustion chamber 670 . Engine 600 may further comprise a drain system fluidically connected to the outlet. The drain system may be configured to release the collected host material to the environment. Alternatively, the drain system may be fluidically connected to a host material storage tank configured to store the collected host material. Engine 600 may further comprise a cooling system fluidically connected to the outlet and configured to use the collected host material to cool the cool cylinder 640 . Engine 600 may further comprise an oxygen supply device operably connected to the combustion chamber 670 and configured to supply oxygen to the combustion chamber 670 . The oxygen supply device may be configured to supply air to the combustion chamber 670 , such as by blowing atmospheric air into the combustion chamber 670 . Alternatively or in addition thereto, the oxygen supply device may comprise an oxygen tank and may be configured to provide pressurized oxygen to the combustion chamber 670 . FIG. 8 illustrates an engine 700 configured to directly utilize gas clathrates as a fuel source. Engine 700 is a double-acting configuration stirling engine coupled to a swash plate to generate rotary motion. Engine 700 comprises, in the illustrated embodiment, four cylinders 705 a , 705 b , 705 c , and 705 d . Each of the cylinders comprises a hot end 710 a , 710 b , 710 c , and 710 d , respectively, configured to transfer heat during operation to a working fluid within each of cylinder. Each of the cylinders comprises a cool end 740 a , 740 b , 740 c (not shown), and 740 d , respectively, configured to remove heat from the working fluid. Engine 700 further comprises multiple conduits 780 a , 780 b , 780 c (not shown), and 780 d , respectively. Each conduit fluidically connects one hot end of a cylinder with one cool end of a different cylinder. For example, conduit 780 a connects hot end 710 a with cool end 740 c (not shown). Conduit 780 b connects hot end 710 b with cool end 740 a . Conduit 780 c connects hot end 710 c with cool end 740 d . Conduit 780 d connects hot end 710 d with cool end 740 b . In this way, the working fluid within each cylinder is in fluidic communication with the working fluid within each of the other cylinders. Conduit 780 a includes a regenerator (not shown). Conduit 780 b includes a regenerator 760 b . Conduit 780 c includes a regenerator (not shown). Conduit 780 d includes a regenerator 760 d . Each of the regenerators is configured to transfer heat to and from the working fluid as it shuttles within the respective conduit. Engine 700 further comprises multiple pistons. Each of cylinders 705 a , 705 b , 705 c , and 705 d house a piston 720 a , 720 b , 720 c (not shown), and 720 d , respectively, slidably engaged within each cylinder. Each of pistons 720 a , 720 b , 720 c , and 720 d is operably connected to a single swash plate 790 . Reciprocating motion of pistons 720 a , 720 b , 720 c , and 720 d translates into rotary motion of the swash plate 790 . Swash plate 790 is operably connected to rotatable shaft 795 . Rotatable shaft 795 may in turn be connected to drive components of a vehicle, such as vehicle 200 of FIG. 3 . Engine 700 further comprises a combustion chamber 770 configured to combust the gas clathrates and supply heat to each of the hot ends 710 a , 710 b , 710 c , and 710 d. Combustion chamber 770 may be operably connected to a vehicle fuel storage system, such as vehicle fuel storage system 110 of FIG. 3 . Any variation of a double-acting stirling engine that is known in the art and is compatible with direct utilization of gas clathrates as fuel may be used. For example, engine 700 may comprise more or less cylinders. In another example, each of cool ends 740 a , 740 b , 740 c , and 740 d may be configured with cooling fins designed to radiate heat away from itself and/or may be configured for liquid cooling. In another example, at least a portion of each of the hot ends 710 a , 710 b , 710 c , and 710 d may be located within the combustion chamber 770 . In yet another example, engine 700 may be configured to utilize heat energy from the exhaust stream from the combustion chamber 770 to heat at least a portion of each of the hot ends 710 a , 710 b , 710 c , and 710 d . Likewise, any working fluid known in the art for a stirling engine may be used, such as, by way on non-limiting example, air, hydrogen, helium, and/or nitrogen. Engine 700 may be configured to further utilize heat energy from the exhaust stream from the combustion chamber 770 to impart heat to the gas clathrate storage vessel, such as the first vessel 111 of FIG. 3 . Combustion chamber 770 may be configured to substantially vaporize any host material dissociated from the gas clathrates. Combustion chamber 770 , or some other components of engine 700 , may be configured to substantially recondense any vaporized host material dissociated from the gas clathrates. Combustion chamber 770 may be configured to melt, but not vaporize, at least a portion of the host material. Combustion chamber 770 may be configured to utilize pulverized gas clathrate solids blown into the combustion chamber 770 . Combustion chamber 770 may be configured to utilize solid gas clathrate chunks, pellets, and/or flakes. Combustion chamber 770 may be configured to utilize gas clathrates as a slurry. Combustion chamber 770 may comprises a grate configured to hold the gas clathrates during combustion of dissociated gas. The grate may be configured to allow liquid host material to drip through the grate. The liquid host material may collect below the grate. The grate may be configured to be stationary. Alternatively, the grate may be configured to rotate at least partially within the combustion chamber 770 . Combustion chamber 770 may be operably connected to a stoker configured to feed gas clathrate solids onto at least a portion of the grate. Combustion chamber 770 may comprise an outlet configured to remove collected host material from the combustion chamber 770 . Engine 700 may further comprise a drain system fluidically connected to the outlet. The drain system may be configured to release the collected host material to the environment. Alternatively, the drain system may be fluidically connected to a host material storage tank configured to store the collected host material. Engine 700 may further comprise a cooling system fluidically connected to the outlet and configured to use the collected host material to cool each of the cool ends 740 a , 740 b , 740 c , and 740 d. Engine 700 may further comprise an oxygen supply device operably connected to the combustion chamber 770 and configured to supply oxygen to the combustion chamber 770 . The oxygen supply device may be configured to supply air to the combustion chamber 770 , such as by blowing atmospheric air into the combustion chamber 770 . Alternatively or in addition thereto, the oxygen supply device may comprise an oxygen tank and may be configured to provide pressurized oxygen to the combustion chamber 770 . Returning to FIG. 3 , engine 160 may also comprise a steam engine. The steam engine may comprise a boiler operably connected to a combustion chamber. The combustion chamber may be operably connected to the vehicle fuel storage system 110 . The combustion chamber may be configured to combust the gas clathrates and also configured to supply heat to the boiler. The boiler may comprise any boiler compatible with automotive use. For example, the boiler may comprise a fire-tube boiler, a water-tube boiler, or a fluidized bed combustion boiler. At least a portion of the boiler may be located within the combustion chamber. The steam engine may be configured to further utilize heat energy from the exhaust stream from the combustion chamber to impart heat to the first vessel 111 . The combustion chamber may be configured to substantially vaporize any host material dissociated from the gas clathrates. The combustion chamber, or some other components of the steam engine, may be configured to substantially recondense any vaporized host material dissociated from the gas clathrates. The combustion chamber may be configured to melt, but not vaporize, at least a portion of the host material. The combustion chamber may be configured to utilize pulverized gas clathrate solids blown into the combustion chamber. The combustion chamber may be configured to utilize solid gas clathrate chunks, pellets, and/or flakes. The combustion chamber may be configured to utilize gas clathrates as a slurry. The combustion chamber may comprise a grate configured to hold the gas clathrates during combustion of dissociated gas. The grate may be configured to allow liquid host material to drip through the grate. The liquid host material may collect below the grate. The grate may be configured to be stationary. Alternatively, the grate may be configured to rotate at least partially within the combustion chamber. The combustion chamber may be operably connected to a stoker configured to feed gas clathrate solids onto at least a portion of the grate. The combustion chamber may comprise an outlet configured to remove collected host material from the combustion chamber. The steam engine may further comprise a drain system fluidically connected to the outlet. The drain system may be configured to release the collected host material to the environment. Alternatively, the drain system may be fluidically connected to a host material storage tank configured to store the collected host material. The steam engine may further comprise an oxygen supply device operably connected to the combustion chamber and configured to supply oxygen to the combustion chamber. The oxygen supply device may be configured to supply air to the combustion chamber, such as by blowing atmospheric air into the combustion chamber. Alternatively or in addition thereto, the oxygen supply device may comprise an oxygen tank and may be configured to provide pressurized oxygen to the combustion chamber. Turning now to vehicle fuel storage system 110 , vehicle fuel storage system 110 may comprise analogous components and systems to that of vehicle fuel storage system 10 . It should be understood that any disclosure regarding either system may be applicable to the other. It should be understood that any disclosure regarding first vessel 11 may also apply equally to the first vessel 111 and vice versa. First vessel 111 may be configured to maintain a first temperature and a first pressure during storage of the gas clathrates. The first temperature and the first pressure may be compatible with maintaining stability of the gas clathrates, such as those temperatures and pressure discussed above regarding first vessel 11 . The first vessel 111 may also be configured to maintain the first temperature and the first pressure during discharge of the gas clathrates from the first vessel. Vehicle fuel storage system 110 may be configured to discharge the gas clathrates as a solid from the first vessel 111 . The vehicle fuel storage system 110 may be configured to discharge from the first vessel 111 the gas clathrates as a slurry of solid gas clathrate particles within a carrier fluid. The carrier fluid may comprise melted host material. Vehicle 200 may further comprise a filtration device to at least partially prevent introduction of the carrier fluid into the engine 160 . The filtration device may be configured to return at least a portion of the carrier fluid to the first vessel 111 . The vehicle fuel storage system 110 may comprise a metering system configured to control introduction of the gas clathrates to the engine 160 . The metering system may be configured as necessary to handle the gas clathrates as either a solid or a slurry. The metering system may comprise a flow meter configured to measure the flow rate of the gas clathrates discharged from the first vessel 111 . The metering system may also comprise a hopper configured to control the feed rate of the slurry to the engine 160 . The vehicle 200 may further comprise a first transport device operably connected to the vehicle fuel storage system 110 and operably connected to the metering system. The first transport device may be configured to transfer the gas clathrates from the vehicle fuel storage system 110 to the metering system. It should be understood that this first transport device is analogous to the first transport device 39 of vehicle fuel system 100 . Any disclosure regarding the first transport device 39 and its interactions with the first vessel 11 and the second vessel 21 are applicable to this first transport device and its interactions with first vessel 111 and the metering system. Vehicle 200 may also be configured such that a portion of the gas clathrates are dissociated into gas and host material and the gas delivered to engine 160 . Thus, engine 160 may be configured to utilize both dissociated gas and gas clathrates as a fuel source. In some embodiments, vehicle 200 further comprises a separation system comprising a second vessel operably connected to the vehicle fuel storage system 110 . This separation system may be configured to dissociate the gas clathrates into at least one gas and a host material. The separation system may be operably connected to a delivery system configured to deliver dissociated gas to engine 160 . It should be understood that the separation system and delivery system are analogous to the separation system 20 and delivery system 50 of vehicle fuel system 100 . Any disclosure regarding separation system 20 and delivery system 50 and their interactions with each other, vehicle fuel storage system 10 , and with a prime mover are applicable to this separation system, delivery system, and their interactions with each other and with vehicle fuel storage system 110 and engine 160 . In such embodiments, the separation system may be configured to deliver dissociated gas to engine 160 and the vehicle fuel storage system 110 configured to deliver solid or slurry gas clathrates to engine 160 . Alternatively, vehicle fuel storage system 110 may not deliver any of the gas clathrates to engine 160 and instead the separation system may also deliver solid or slurry gas clathrates to engine 160 . For example, the separation system may comprise a second vessel that comprises a first outlet configured to discharge the dissociated at least one gas and a second outlet configured to discharge the solid or slurry gas clathrate. It should be understood that dissociated gas may also be present in the discharge from such a second outlet. In addition to a separation system or as an alternative thereto, vehicle fuel storage system 110 may be configured to dissociate a portion of the gas clathrates into gas and host material. In such embodiments, vehicle fuel storage system 110 would be configured to both discharge dissociated gas and also gas clathrates as either a solid or slurry. For example, first vessel 111 may be configured to vary the temperature and the pressure of the first vessel 111 to a second temperature and a second pressure during discharge of the gas clathrates such that a portion of the gas clathrates are dissociated into at least one gas and a host material. For example, the second temperature may be about ambient temperature and/or at any temperature that is higher than the operating temperature for storage of the gas clathrates. Alternatively, the second temperature that is about the same as the operating temperature for storage of the gas clathrates, but the second pressure may be a lower pressure than that used for storage. The second temperature and second pressure may be such as those disclosed above regarding second vessel 21 . In such embodiments, vehicle fuel storage system 110 may be configured to deliver to the engine 160 the dissociated gas either separately from the discharged gas clathrates or may deliver the dissociated gas with the discharged gas clathrates. Additionally, dissociated gas may be discharged at the same time or at a different time as the solid or slurry gas clathrates are discharged. Similar to first vessel 11 , first vessel 111 may comprise a gas outlet configured to discharge the dissociated at least one gas and a second outlet configured to discharge the solid or slurry gas clathrate. It should be understood that dissociated gas may also be present in the discharge from such a second outlet. Dissociated host material may serve as a carrier fluid for facilitating discharge of the solid gas clathrates as a slurry. Additionally or alternatively, vehicle fuel storage system 110 may comprise a drain configured to remove at least a portion of dissociated host material from first vessel 110 . In embodiments where dissociated gas is delivered to the engine 160 in addition to discharged gas clathrates, vehicle 200 may also comprise a delivery system configured to deliver gas dissociated from gas clathrates within first vessel 111 and/or the second vessel of a separation system to the engine 160 . It should be understood that the delivery system may be analogous to the delivery system 50 of vehicle fuel system 100 and may be operably connected to vehicle fuel storage system 110 and/or the second vessel of a separation system. Any disclosure regarding delivery system 50 and its interactions with separation system 20 are applicable to this delivery system and its interactions with vehicle fuel storage system 110 and/or the separation system. The delivery system may be configured to introduce the discharged at least one gas into the engine 160 at substantially the same time as the discharged gas clathrates are introduced to the engine 160 . The delivery system may be configured to alternately introduce the discharged at least one gas and the discharged gas clathrates into the engine 160 . In embodiments where dissociated gas is delivered to the engine 160 in addition to discharged gas clathrates, the engine 160 may comprises a first combustion chamber configured to receive and combust dissociated at least one gas. The engine 160 may further comprise a second combustion chamber configured to receive and combust discharged gas clathrate. The first combustion chamber may be thermally coupled to the second combustion chamber, whereby heat generated in the first combustion chamber is used to heat the second combustion chamber. Alternatively, the first combustion chamber may be thermally isolated from the second combustion chamber. In such embodiments, the engine 160 may comprise an internal combustion engine or an external combustion engine. Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having ordinary skill in the art, with the aid of the present disclosure, that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. The scope of the invention is therefore defined by the following claims.

This disclosure relates generally to the use of gas clathrates. More particularly, this disclosure relates to systems, methods, and apparatuses related to the use of gas clathrates as a fuel source for automobiles. The gas clathrates may first be dissociated into at least one gas and the at least one gas delivered to the prime mover of a vehicle or the gas clathrates may be directly utilized by the prime mover as a fuel source.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the U.S. National Stage of International Application PCT/US2009/062537, filed Oct. 29, 2009, which claims benefit of U.S. Application No. 61/109,367, filed Oct. 29, 2008, each of which is hereby incorporated by reference. The invention relates to detecting coagulation and coagulation-related activities such as, for example, agglutination and fibrinolysis of samples (e.g., human blood samples). More particularly, the invention relates to methods and apparatus for obtaining a coagulation time of a sample (e.g., plasma, blood concentrate, citrated blood) using NMR-based detectors. BACKGROUND OF THE INVENTION Hemostasis, the physiological process of preventing excess blood loss by arresting flow via the formation of a hemostatic plug while maintaining blood in a fluid state within intact blood vessels, is maintained by tightly regulated interactions of the blood vessel wall, blood platelets, and blood plasma proteins. Under normal conditions there is a delicate balance between the individual components of the hemostatic system. Any disturbances in this balance, called the hemostatic potential, can result in either uncontrolled bleeding or formation of unwanted blood clots (thrombosis). Clinical assessment of clotting function has long been recognized to be important in management of surgical patients. Preoperatively, assessment of clotting function of a patient's blood is utilized as a predictor of risk of patient bleeding, allowing advanced preparation of blood components. Perioperative monitoring of clotting function of a patient's blood is also important because coagulopathies can be induced by hemodilution of procoagulants, fibrinogen and platelets, as a result of consumption of coagulation factors during surgical procedures, or cardiac procedures (e.g., cardiopulmonary bypass). Post-operative assessment of clotting function can also be crucial to a patient's successful recovery. Coagulation is defined as transformation of a liquid or solution into a soft, semi-solid or solid mass. Blood naturally coagulates or clots to form a barrier when trauma or pathologic conditions cause vessel damage. There are two well-recognized coagulation pathways: the Contact Activation or thromboplastin-controlled pathway (formerly known as the extrinsic pathway) and the Tissue Factor or prothrombin/fibrinogen-controlled coagulation pathway (formerly known as the intrinsic pathway). Both the Contact Activation and Tissue Factor pathways result in the production of thrombin, a proteolytic enzyme which catalyzes the conversion of fibrinogen to fibrin. Blood coagulation or clotting assays are principally used for screening or diagnosis and/or monitoring the hemostatic or coagulation status of a subject (e.g., a patient). There are many types of coagulation assays, including prothrombin time (PT), partial thromboplastin time (PTT) or activated partial thromboplastin time (APTT), fibrinogen assay, thrombin clotting time (TCT, TAT, or TT), activated clotting time (ACT). PT monitors the Contact Activation pathway of coagulation, and is useful for monitoring, e.g., antithrombotic therapy, for example, warfarin therapy. PTT or APTT detects factor changes in the Tissue Factor coagulation cascade (e.g., factors VIII, IX, XI, XII, other enzymes and factors), and is used primarily to monitor heparin therapy. Similarly, ACT evaluates the Tissue Factor pathways of coagulation and is useful for monitoring e.g., anticoagulation therapy, e.g., heparin therapy in situations where an APTT test cannot be performed, such as, for example if a patient was administered a high dose of heparin. TCT is not sensitive to deficiencies in either pathway, and measures a common pathway at the level of prothrombin to test for fibrinogen polymerization. The fibrinogen assay by the Clauss method (clotting method) utilizes activating levels of thrombin to initiate coagulation of a sample, and resulting coagulation time correlates with levels of fibrinogen in the sample. The majority of coagulation assays for clinical assessment of patients are performed using the PT test. The PT test measures the activation of the Contact Activation coagulation pathway by addition of tissue thromboplastin. PT tests can be used for a number of different applications, including, for example, monitoring patients undergoing antithrombotic therapy (e.g., anticoagulant therapy) and assessing the status of a various clotting disorders including, e.g., acquired platelet function defect, congenital platelet function defects, congenital protein C or S deficiency, deep intracerebral hemorrhage, DIC (Disseminated intravascular coagulation), factor II deficiency, factor V deficiency, factor VII deficiency, factor X deficiency, hemolytic-uremic syndrome (HUS), hemophilia A, hemophilia B, hemorrhagic stroke, hepatic encephalopathy, hepatorenal syndrome;,hypertensive intracerebral hemorrhage, idiopathic thrombocytopenic purpura (ITP), intracerebral hemorrhage, lobar intracerebral hemorrhage, placenta abruption, transient ischemic attack (TIA), and Wilson's disease. Traditionally, coagulation parameters are determined by “wet chemistry” testing, wherein an aliquot of blood sample is mixed with one or more liquid coagulation reagents and the point of time at which the blood clots is detected. Results are indicated either directly (in seconds) or in the form of derived quantities such as ratio to a respective normal value (in percent). With respect to PT, common derived results for clotting indication include % Quick and the WHO standard, INR (International Normalized Ratio) values. A number of various apparatuses and methods exist for measuring coagulation time of blood samples. Coagulation detection methods include detecting an increase in viscosity (viscosity detection method), detecting turbidity (turbidity detection method), and combined viscosity/turbidity detection methods. Other methods of coagulation detection employ multi-layered porous membranes impregnated with one or more coagulation reagents. Impregnated coagulation reagent(s) initiate coagulation of a sample (e.g., a predetermined blood volume), producing a detectable signal and the assays sometimes require predetermined blood volumes. Still other methods employ detection of oscillation of magnetic particles suspended in a reagent in a changing electric field, wherein oscillations change as a blood sample clots. Still other methods simply measure a change in light absorbance through a sample before and after a clotting reaction. Most current methods have limitations which make them unsuitable or inconvenient for point of care testing or home use. Some require special blood sample preparation and handling or sophisticated equipment, making them suitable only for central laboratory facilities having qualified staff Others, though possible for home use, are not cost effective for commercialization, or encounter implementation challenges (e.g., methods that require filtration of a sample through porous membranes pose wetting and uniform reagent impregnation difficulties). Furthermore, besides cost and challenge of operation, a number of methods do not measure coagulation directly; and most tests do not measure coagulation without the use of an additive. Indirect measurement has been known to pose problems of accuracy in many samples. Other methods, while appearing to function well, can be limited to a narrow range of blood types, therapeutic windows, restricted by a long list of interfering factors or require large volumes of blood. Thus, current blood coagulation tests are generally complex and the bulk of them are performed in a centralized clinical laboratory, at a clinic, or at a physician's office. Required visits to a clinic or a doctor's office on a regular basis to monitor anticoagulation therapy can be both inconvenient and expensive for a patient. Thus, there is a need for easy-to-use, compact, and portable instruments to facilitate use at “point of care” (POC) locations, within a surgical suite, or for a patient to monitor blood coagulation status at home. SUMMARY OF THE INVENTION The present invention provides non-optical methods for monitoring and measuring coagulation (e.g., blood coagulation, plasma coagulation) using nuclear magnetic resonance parameters detectable by relaxometer readings. Provided methods allow for accuracy and precision at point of care (POC) settings or at home settings, which are currently available only through central laboratory facilities. Provided methods can be used optionally without a need for additives beyond a coagulation reagent for initiating the coagulation process to be measured; can measure coagulation directly without sample interference due to non-invasive detection; allows fast determination of coagulation state changes, thereby providing real time monitoring of samples; are not limited to blood type, therapeutic window or other interfering factors; are not limited to clear samples required for optical assessment; require only small amounts of coagulating sample; and can provide highly time-resolved coagulation curves that allow for profiling of coagulation abnormalities. The present invention further provides test carriers for containing samples used in methods provided herein. One embodiment of the present invention is a method for measuring a coagulation time. The method comprises providing a test carrier containing a sample within a detection volume of a NMR detector and measuring a change in a NMR parameter over time to determine the coagulation time, wherein the measured change in NMR parameter over time provides a measurement of coagulation time A further embodiment of the present invention is a method for determining the coagulation state and/or coagulation time of a sample using a nuclear magnetic resonance (NMR) device. The method includes the following steps: a) providing a test carrier containing the sample within a detection volume of an NMR detector of the NMR device; b) performing NMR measurements on the sample to determine at least two values of an NMR parameter of the sample over time, the NMR parameter being responsive to coagulation in the sample; and c) assessing the values determined in step b) to obtain the coagulation state and/or coagulation time of the sample. A further embodiment of the present invention is a method for determining the extent of coagulation of a blood sample obtained from a subject. The method includes the following steps: a) measuring an NMR parameter of the blood sample, wherein the NMR parameter is responsive to the extent of coagulation; b) comparing the measured value of the NMR parameter obtained in step a) with a known value for the NMR parameter wherein the known value has been correlated with the extent of coagulation in blood; c) assessing the extent of coagulation from the comparison made in step b). A further embodiment of the present invention is a method for determining the coagulation time of a blood sample obtained from a test subject. The method includes the following steps: a) measuring an NMR parameter of the blood sample, wherein the NMR parameter is responsive to the extent of coagulation; b) comparing the measured value of the NMR parameter at a given time obtained in step a) with a standard coagulation-time-curve that provides a standard curve of change of the NMR parameter over time due to coagulating blood; and c) determining the coagulation time from the comparison in step b). A further embodiment of the present invention is a method for monitoring coagulation of a blood sample from a test subject. The method includes measuring a plurality of values of an NMR parameter of the blood sample over time, wherein the NMR parameter is responsive to the coagulation state of the blood sample. A further embodiment of the present invention is a method for diagnosing an abnormal clotting event in a blood sample of a test subject. The method includes a) providing at least one test carrier, each test carrier containing a blood sample from the test subject, and being within a detection volume of an NMR detector; b) obtaining test data of an NMR parameter over time, the NMR parameter being responsive to coagulation in the blood sample of each test carrier; and c) comparing one or more characteristics of the test data obtained in step (b) with those of a standard coagulation-time-curve of the NMR parameter responsive to normal coagulation to thereby diagnose an abnormal clotting event in the subject. A further embodiment of the present invention is a test carrier. In some embodiments a test carrier comprises a carrier and one or more coagulation reagents that induce or support coagulation in a sample. In other embodiments a test carrier comprises a carrier and one or more coagulation reagents that activate coagulation. In certain embodiments a test carrier includes a carrier in which one or more interior surfaces have been etched. In certain embodiments, a test carrier includes a carrier suitable for NMR measurements and one or more coagulation reagents that induce or support coagulation in a sample. The foregoing will be apparent from the following more particular description of example embodiments with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following detailed description, references are made to illustrative embodiments of methods and apparatus for carrying out the invention. It is understood that other embodiments can be utilized without departing from the scope of the invention. Preferred methods and apparatus are described for performing blood coagulation tests of the type described herein. Throughout the description, where methods are described as having, including, or comprising steps, it is contemplated that, additionally, there are methods and systems of the present invention that consist essentially of or consist of, the recited processing steps. It should be understood that the order of steps or order for performing certain actions is immaterial so long as the invention remains operable. Moreover, two or more steps or actions may be conducted simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts illustrative elements of an NMR detector and test carrier utilizing underlying principles of the present invention for measurement of coagulation time. FIG. 2 depicts a graphical result demonstrating reduction in T 2 relaxation time during coagulation induced by addition of calcium chloride to a mixture of plasma and an APTT reagent, CEPHALINEX®. FIG. 3 depicts a graphical result providing normal and abnormal aPTT plasma clotting/coagulation obtained by measuring changes of T 2 relaxation time over time using time-resolved relaxation time acquisition methodology. FIG. 4 depicts a graphical result providing normal and abnormal PT plasma clotting/coagulation obtained by measuring changes of T 2 relaxation time over time using time-resolved relaxation time acquisition methodology. FIG. 5 depicts a graphical result providing two discrete abnormal plasma clotting/coagulation curves, relative to normal plasma clotting/coagulation, obtained by measuring changes of T 2 relaxation time over time using time-resolved relaxation time acquisition methodology. FIG. 6 depicts a graphical result providing a correlation between a coagulation measurement method of the present invention and a commercial bench-top coagulation instrument from Diagnostica Stago (Parsippany, N.J.), called the Start-4. Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPPT) were measured with both methods. FIGS. 7 a and 7 b depict schematic graphical representations of two different magnetic resonance pulse sequences for measuring T 2 : ( 7 a ) A spin echo sequence consists of two radiofrequency (RF) pulses: a 90°, x phase, and a 180°, y phase, separated by a delay τ. The echo signal appears at time 2τ. T 2 is measured by obtaining the echo signal from successive cycles using incremental values of τ. The recycle delay, d 1 , is typically 1-3 sec. ( 7 b ) A CPMG sequence allows for much faster T 2 measurements because multiple echos are acquired in rapid succession by a series of 180°, y phase RF pulses and signal acquisitions. T 2 measurements acquired with a CPMG sequence avoid diffusion artifacts because of the short time over which the measurement occurs. DETAILED DESCRIPTION OF THE INVENTION In a broad aspect, the present invention provides methods for detecting a change in a sample (e.g., a blood sample) coagulation state, for example, monitoring blood clotting (hereinafter also “coagulation”) using time-resolved relaxation time acquisition methodology. Provided methods for measuring coagulation time of a sample (e.g., a blood sample) are simple to practice, rapid, and reliable. As used herein, a “subject” encompasses mammals and non-mammals. Examples of mammals include, but are not limited to, any member of the mammalian class, including humans, non-human primates such as chimpanzees, and other apes and monkey species; farm animals such as cattle, horses, sheep, goats, swine; domestic animals such as rabbits, dogs, and cats; laboratory animals including rodents, such as rats, mice and guinea pigs; etc. Examples of non-mammals include, but are not limited to, birds, fish, etc. In some embodiments a subject includes a clinical patient. As used herein, a sample can be a biologic sample, for example, a blood sample (e.g., whole blood, plasma, blood concentrate, citrated blood) from a subject, or a liquid containing compounds (e.g., monomers) that can coagulate, for example, upon providing conditions suitable for coagulation. A blood sample can be obtained from a subject (e.g., a patient) by traditional means such as venipuncture or a finger prick. A sample can be applied, for example via sample application port, onto a test carrier. In one aspect of the invention, a sample of blood obtained from a subject can be used without additional manipulation in the methods and apparatus of the invention. In some embodiments a whole blood sample is used in conjunction with provided methods. Alternatively, a blood sample obtained from a subject can be treated to remove, either completely or partially, red blood cells. In some embodiments blood cells are removed by any of known methods, such as, for example, centrifugation, reacting sample with a red blood cell agglutinant, or by employing a red blood cell filter. In some embodiments plasma is used in conjunction with provided methods. In some embodiments sample blood or plasma can be optionally diluted prior to coagulation. A diluent can simply be an aqueous solution or it can be a non-aqueous solution, and optionally can include various additives, such as, for example, salts, proteins, sugars, saccharides, metal ions, such as calcium, magnesium, lanthanides, and the like. Certain formulations of a diluent can include gelatin-containing composition and/or emulsion. In some embodiments, a diluent is a saline solution. In some embodiments, a diluent is a buffer solution, e.g., citrate buffer A sample may be maintained at a temperature of about 20° C. to about 40° C. In some embodiments a sample is maintained at about room temperature, about 22° C., about 25° C., about 30° C., about 35° C., about 37° C. or about 40° C. In certain embodiments, a blood sample is maintained at about body temperature, or about 37° C. Regardless of a preferred selected temperature, a sample is preferably maintained at about constant temperature throughout the process of obtaining measurement of NMR readings. A coagulation time can be one or more of the blood coagulation times, including prothrombin time (PT), partial thromboplastin time (PTT), activated partial thromboplastin time (APTT), fibrinogen assay, thrombin clotting time (TCT), fibrinogen assay, and activated clotting time (ACT). In certain embodiments a sample may be heparinized and/or mixed with one or more reagents. In some embodiments a reagent may include, for example, an anti-coagulant. In other embodiments, a reagent may include, for example, a coagulant, a coagulation agent (e.g., calcium (e.g., calcium chloride)), kaolin, celite, ellagic acid, glass particles, thrombin, thromboplastin, PT reagent, PTT or APTT reagent, ACT reagent, TCT reagent, fibrinogen reagent), or a heparin neutralizing or deactivating agent (e.g., heparinase, protamine). As used herein, “coagulation reagent” refers to a reagent that induces and/or supports (e.g., accelerates) coagulation when mixed with the sample, for example, a blood sample, under conditions suitable for the reagent to induce or support coagulation in the sample. These conditions are known in the art. Coagulation reagents include but are not limited to a prothrombin time (PT) reagent, a partial thromboplastin time (PTT)/activated partial thromboplastin time (APTT) reagent, thrombin clotting time (TCT) reagent, fibrinogen reagent, an activated clotting time (ACT) reagent, calcium (e.g., calcium chloride)), kaolin, celite, ellagic acid, glass particles, thrombin, thromboplastin; wherein specific agents comprising reagents for each test(s) are well known and have been described in the art, and are available through commercially available sources. For example, a PT reagent can include any of STA® Neoplastine CL, STA® Neoplastine CL Plus (Diagnostica Stago, Parsippany, N.J., USA); Thromborel S, Innovin, Thromboplastin CL, Thromboplastin C Plus (Dade Behring, Liederbach, GERMANY); Plastinex (BioData Corporation, Horsham, Pa., USA); Diaplastin (Diamed AG, SWITZERLAND); Thromboplastin, Thromboplastin M1 (Helena Laboratories, Beaufort, Tex., USA); PT-Fibrinogen, PT-Fibrinogen HS, PT-Fibrinogen HS+, PT-Fibrinogen Recombinant, Brain Thromboplastin, RecombiPlasTin (Instrumentation Laboratory, Bedford, Mass., USA); Simplastin, Simplastin Excel, Simplastin Excel S, Simplastin L, MDA Simplastin L, Simplastin HTF, MDA Simplastin HTF (bioMerieux, St. Laurent, Quebec, CANADA); Thromboplastin-D with Calcium, Thromboplastin-DL with Calcium, Thromboplastin-DS, Thromboplastin Liquid (Pacific Hemostasis, Huntersville, N.C., USA); Thromboplastin with Calcium, Thromboplastin HS with Calcium, Thromboplastin M with Calcium, Thromboplastin XS with Calcium, ThromboMAX HS with calcium, ThromboMAX with calcium (Sigma Diagnostics, St. Louis, Mo., USA). An APTT/PTT reagent can include for example any of: Automated APTT Reagent, SILIMAT, Platelin®L, Platelin®LS, and MDA Platelin®L (bioMerieux, St. Laurent, Quebec, CANADA); Actin®, Actin®FS, Actin®FSL, and Pathromtin®SL (Dade Behring, Liederbach, GERMANY); APTT-SP, APTT-C, SynthASil, SynthAFax, and ThromboslL (Instrumentation Laboratory, Bedford, Mass., USA); SPECTRA™ (Analytical Control Systems, Inc., Fishers, Ind., USA); Thrombosil, Activated Thrombofax (Ortho, Raritan, N.J., USA); CK-PREST, STA® PTT Automate (Diagnostica Stago, Parsippany, N.J., USA); Cephalinex® (BioData Corporation, Horsham, Pa., USA); APTT Reagent (Diamed AG, SWITZERLAND); APTT Reagent, APTT-FS, APTT-FSL, ALEXIN, ALEXIN HS, and ALEXIN LS (Sigma Diagnostics, St. Louis, Mo., USA). A fibrinogen reagent can include, for example, Fibri-Prest, STA®-Fibrinogen 5 (Diagnostica Stago, Parsippany, N.J., USA); Multifibren U, Fibrinogen Determination (Dade Behring Thrombin) (Dade Behring, Liederbach, GERMANY); Fibrinogen Assay (BioData Corporation, Horsham, Pa., USA); Fibrinogen Assay (Helena Laboratories, Beaufort, Tex., USA); QFA (bovine thrombin), Fibrinogen C, PT-Fibrinogen, PT-Fibrinogen HS, PT-Fibrinogen HS+, PT-Fibrinogen Recombinant, RecombiPlasTin. RecombiPlasTin4.5 (Instrumentation Laboratory, Bedford, Mass., USA); Fibriquik, Fibriquik (MDA Fibrinogen I-delta), Fibriquik (MDA Fibrinogen II-seconds) (bioMerieux, St. Laurent, Quebec, CANADA); Thromboscreen (Pacific Hemostasis, Huntersville, N.C., USA); Accuclot Fibrinogen (Sigma Diagnostics, St. Louis, Mo., USA). A TCT reagent can include, for example, any commercial or produced source of animal thrombin, e.g., STA®-Thrombin, Thrombin 10, (Diagnostica Stago, Parsippany, N.J., USA); Human alpha-Thrombin (Sigma Diagnostics, St. Louis, Mo., USA); MDA® Thromboquik, (bioMerieux, St. Laurent, Quebec, CANADA); BC-Thrombin reagent (Dade Behring, Liederbach, GERMANY). An ACT reagent can include, for example, any commercial or produced source of silica based coagulation activator compound, (e.g., kaolin, celite, ellagic acid, glass particles). Further, combinations of coagulation reagents can be used as reagents to induce and/or support coagulation. As used herein, “carrier” is understood to mean any localizer of a liquid sample, for example, a well, an indentation, a support, a channel, a reservoir, a sunken volume, a compartment, a recessed area, an enclosure with or without an opening, a tube, or a trough. The term “test carrier” means a carrier into which a sample is deposited for analysis. A test carrier can be placed within the detection volume of an NMR detection coil, for example a relaxometer (i.e., Bruker Minispec) or a customized miniature relaxometer. A sample can be placed in the test carrier either before or after the test carrier is placed within the detection volume of a NMR detection coil. In certain embodiments, coagulation test time based on the measurement of viscosity of the sample using NMR relaxivity measurements can be ascertained under temperature control. It has been found that an effective T 2 relaxation rate (i.e. 1/T 2 ) can be related to a coagulation state of a sample, and coagulation time can be determined by monitoring one or more parameters relating to a series of T 2 relaxation rate measurements over time (herein referred to as a coagulation-time-curve). Typically, in determining a coagulation time, a tailored radiofrequency (RF) pulse sequence is applied to a test carrier containing a sample; and RF echo signals are monitored and analyzed to determine one or more NMR parameters (e.g., T 2 ). For example, an effective T 2 relaxation rate as measured by a custom CPMG (Carr-Purcell-Meiboom-Gill) pulse sequence can be used to measure a temporal change in coagulation state. While true T 2 measurements with methods such as spin echos (see, e.g., FIG. 7 a ) can be obtained, such measurements do not typically yield the same sensitivity to coagulation state as methods provided herein, and thus are not useful in the current application. For example, to obtain a useful relaxation parameter for measuring a coagulation time with adequate temporal resolution (e.g. sampling rate), CPMG sequence parameters are adjusted such that obtained relaxation curves are sampled to obtain optimal coagulation response measurements, as described in further detail herein. Suitable CPMG sequences for measuring effective T 2 of a sample can be characterized by the following sequence of steps: 1) waiting (i.e., not applying a radiofrequency pulse to a sample) at least for a time period given by a recycle delay (e.g., the time between initiation of a relaxation measurement and a first radiofrequency pulse, time between the end of prior sequence measurement to allow for the system to return to equilibrium (e,g., about 0.5 to about 5 seconds); 2) applying a 90° radiofrequency pulse to the sample, 3) waiting for a time period given by, for example, one-half the inter-echo delay, 4) applying a 180° radiofrequency pulse to the sample, 5) waiting for a time period given by the inter-echo delay, and optionally, repeating steps 4) and 5) one or more times. See, e.g., FIG. 7 b . In certain embodiments a relaxation measurement optionally coincides with one or more of completion of a previous pulse sequence measurement, insertion of a sample into the magnet, etc. In particular embodiments initiation of a relaxation measurement coincides with completion of a previous relaxation measurement pulse sequence. Following application of each 180° radiofrequency pulse, a sample responds with an echo that can be acquired to determine T 2 by methods known in the art. See, e.g., Can, H. Y., and Purcell, E. M., “Effects of Diffusion on Free Procession in Nuclear Magnetic Resonance Experiments,” Phy. Rev. 904, No. 3:630 (1954); Meiboom, S.; and Gill, D., “Modified Spin-Echo Method for Measuring Nuclear Relaxation Times,” Rev. Sci. Inst. 29 (1958), which are hereby incorporated by reference; and, described, e.g., U.S. Pat. Nos. 6,690,166, 5,023,551. With increasing repetitions of steps 4) and 5), echos become weaker, leading to a practical limit of how many echos can be recorded with a single CPMG sequence using a given device and given measurement conditions/settings. In certain embodiments all echos within the practical limit of detectable echos are recorded. In other embodiments less than all echos within the practical limit of detectable echos in a single CPMG sequence are recorded. For example, spectrometer recording hardware may constrain the total number of echos that can be recorded. In this case, for example, a subset of detectable echos are recorded, (e.g., acquiring one of every four echos (e.g., herein referred to as a CPMG sequence characterized by a dummy echo value of three)). In some embodiments more than one CPMG sequence is employed, e.g., more than one measurement of T 2 is performed per sample. When more than one measurement of T 2 is performed per sample, each of the CPMG sequence(s) are separated in time by a recycle delay. In the case of blood coagulation that is expected to be characterized by blood coagulation times on the order of several minutes and/or if low time resolution of the blood coagulation curve is required, parameters characterizing a custom CPMG sequence can be determined using methods known in the art, because the time between T 2 value measurements is large compared to the signal decay time used to determine T 2 . Typically, blood coagulation times are short and/or higher time resolution is preferred. For example, for T 2 values of larger than 1.5 seconds and T 1 values larger than 1.5 seconds, upon first approximation, a dwell time (that is, acquisition time plus recycle delay) of about 5 seconds would appear to be needed to measure true sequential T 2 values. Accordingly, for very short blood coagulation times, for example, of about ˜10 seconds, one would expect to only be able to obtain one, or at most two of measurements of true T 2 prior to coagulation. Generally, it is desired to measure the time course of coagulation with as high as possible time resolution. Higher time resolution typically means higher accuracy of parameters characterizing coagulation, for example, coagulation times and better comparison between coagulation curves, for example, comparison of a patient's blood/plasma coagulation curve with a standard curve for normal blood/plasma coagulation (see, e.g., Example 3). It has now been found that the parameters of a CPMG sequence can be optimized to allow determination of “effective” T 2 values (note, the term “T 2 ” as used herein, if not specifically denoted as “effective” refers to both “true” and “effective” T 2 ) that yield high sensitivity to reflect changes in coagulation state while providing adequate temporal resolution, or dwell time (e.g. the time between T 2 measurements must be short enough to provide a kinetic trace throughout the coagulation process). This optimization allows for sensitive measurements over the time course of the coagulation process, thus generating a series of T 2 measurements, which provide a metric by which coagulation time is determined. The measured T 2 value is actually an effective T 2 because the T 2 value is influenced by the optimization of the CPMG sequence, that is, the “true” T 2 requires acquisitions times that are not amenable to a short dwell times; therefore effective T 2 measurements are required. To optimize CPMG sequence measurements, parameters are changed to: 1) maximize the change in T 2 measurements over the coagulation process (maximize overall delta T 2 ); 2) minimize noise levels of measurements taken (e.g., particularly at the upper and lower T 2 measurement extremes); and to increase the number of T 2 measurements taken over time in order to provide adequate sample measurements over the time course of coagulation so as to generate a useful coagulation wave form. Using the principles described herein in conjunction with knowledge in the art, one skilled in the art could modify parameters described herein in various combinations to achieve the results taught in the present methods. In addition or alternatively, with the provided description, one skilled in the art may modify parameters that may vary slightly from the provided ranges, and/or in conjunction with other prarameters in a CPMG sequence, or other sequential relaxation signal measurements, to similarly optimize relaxation measurement sequence(s) to obtain coagulation measurements as provided herein. In some embodiments, a recycle delay is between 0.1 seconds and 100 seconds. In particular embodiments, a recycle delay is between 0.5 seconds and 1 second. In certain embodiments, a recycle delay is about 1 second. In some embodiments, an inter-echo delay is between 0.01 milliseconds and 10 milliseconds. In particular embodiments, an inter-echo delay is between 0.2 milliseconds and 2 milliseconds. In certain embodiments, an inter-echo delay is about 0.5 milliseconds. In some embodiments, the number of acquired echos is between 1 and 10,000. In particular embodiments, the number of acquired echos is between 500 and 2,000. In certain embodiments, the number of acquired echos is between 1500 and 2000. In some embodiments, the number of dummy echos is between 0 and 50. In particular embodiments, the number of dummy echos is between 0 and 10. In certain embodiments, the number of dummy echos is between 0 and 3. Acquisition time is known in the art, and, in particular with regard to CPMG pulse sequence measurements, is the interecho delay time times the number of acquired echoes, times the sum of one plus the number of dummy echoes in a sequence: at=[ied*ae*(1+de)]. In some embodiments, an acquisition time is between 0.01 milliseconds and 5,100 seconds. In particular embodiments, an acquisition time is between 0.1 and 44 seconds. In certain embodiments, an acquisition time is between about 0.5 and about 8 seconds. In particular embodiments, an acquisition time is about 3.5 seconds or about 4.5 seconds. Dwell time is known in the art, and, in particular with regard to CPMG pulse sequence measurements, is the length of a recycle delay plus the length of acquisition time of a sequence: dt=[rd+at]. In some embodiments, a dwell time is between 0.1 seconds and about 5,200 seconds. In particular embodiments, a dwell time is between 0.6 and 45 seconds. In certain embodiments, a dwell time is between about 1 second and about 6 seconds. In particular embodiments a dwell time is about 4.5 or about 5.5 seconds. In some embodiments a dwell time is sufficient to allow for taking at least two T 2 values while sample is coagulating and before the sample is coagulated. In some embodiments a dwell time is sufficient to allow for taking at least five T 2 values while a sample is coagulating and before the sample is coagulated. In certain embodiments a dwell time is sufficient to allow for taking at least ten T 2 values while a sample is coagulating and before the sample is coagulated. In an embodiment of the present invention, a recycle delay is between 0.1 and 100 seconds, the number of acquired echos is between 1 and 10,000, the number of dummy echos is between 0 and 50, an inter-echo delay is between 0.01 and 10 milliseconds, and the number of T 2 measurements (i.e., number of sequential CPMG sequences) is between 2 and 10,000, leading to acquisition times between 0.00001 seconds and 5,100 seconds and dwell times between 0.1 second and 5,200 seconds. In a further embodiment of the present invention, a recycle delay is between 0.5 and 1 seconds, the number of acquired echos is between 500 and 2,000, the number of dummy echos is between 0 and 10, an inter-echo delay is between 0.2 and 2 milliseconds, and the number of T 2 measurements (i.e., number of sequential CPMG sequences) is between 100 and 500, leading to acquisition times between 0.1 and 44 seconds and dwell times between 0.6 and 45 seconds. In a preferred embodiment of the present invention, a recycle delay is between about 0.8 and about 1 second, the number of acquired echos is between about 1650 and about 1850, the number of dummy echos is between 0 and 5, and an inter-echo delay is between about 0.3 and about 0.7 ms leading to acquisition times between about 0.5 and about 7.8 seconds and dwell times between about 1.3 and about 8.8 seconds. In a further preferred embodiment of the present invention, a recycle delay is about 1 second, the number of acquired echos is about 1,750, the number of dummy echos is about 3, and an inter-echo delay is about 0.5 milliseconds, leading to an acquisition time of about 3.5 seconds and a dwell time of about 4.5 seconds. Determination of coagulation times using methods of the present invention is based on the measurement of a nuclear magnetic parameter, typically T 2 , over time. In some embodiments, one measurement of T 2 of a coagulating sample at a time before the sample is substantially fully coagulated can be sufficient to determine the extent of coagulation and/or a coagulation time. For example, if a T 2 value has been determined for a normally coagulating sample, the T 2 value and corresponding time can be matched (e.g., by visual inspection, computationally, etc.) to a pre-determined standard coagulation-time-curve for the type of coagulating sample. If a standard coagulation-time-curve has been correlated with the extent of coagulation for the type of coagulating sample (i.e., the extent of coagulation for given T 2 values at given times on the standard coagulation-time-curve has been determined), a single T 2 measurement can provide the extent of coagulation. Further, comparison of a T 2 value and corresponding time with a standard coagulation-time-curve can allow determination of a sample coagulation time or determination of an estimate of the sample coagulation time. For example, if a measured T 2 value at a given time point matches a T 2 value of the standard curve for the given time point, the sample coagulation time could be associated with the standard coagulation-time-curve. In some embodiments, a plurality of T 2 values over time are determined using methods of the present invention to assess coagulation, for example, to determine coagulation state (i.e., not coagulated or coagulated), the extent of coagulation (e.g., percentage coagulation), and/or a coagulation time (e.g., prothrombin time (PT), partial thromboplastin time (PTT), activated partial thromboplastin time (APTT), thrombin clotting time (TCT), fibrinogen assay clotting time, activated clotting time (ACT)). Typically, for determination of a coagulation time of a plasma or whole blood sample, the start time for coagulation is the timepoint when coagulation is initiated in the sample, for example, by mixing a coagulation activating reagent (e.g., calcium) with a sample. A plurality of T 2 values are measured before the sample is substantially fully coagulated, and, typically, further one or more T 2 values are determined for the substantially fully coagulated sample. A resulting coagulation time curve provided by the measured T 2 values over time allows for a determination of the coagulation time. As can be seen for normal and abnormal plasma coagulation curves in FIGS. 2 to 6 , coagulation typically leads to a decline of the measured T 2 values from a top plateau to a bottom plateau. See Exemplification and FIGS. 2 to 6 . A coagulation time can be determined based on a measured coagulation time curve alone, by comparison with a standard coagulation-time-curve, and/or by normalizing with a pre-determined calibration factor. For example, based on an obtained coagulation time curve alone, coagulation time can be determined as the time from coagulation initiation, for example, using a coagulation reagent, to the time point that the bottom plateau is reached. A preferred way of determining a coagulation time from measured T 2 values is to average, independently, T 2 values of a top plateau to obtain a top plateau value T 2,t and T 2 values of a bottom plateau to obtain a bottom plateau value T 2,b , and determine the time for which T 2 is at the value T 2,b +(T 2,t −T 2,b )/2 on the coagulation time curve, and normalizin obtained time with a pre-determined calibration factor. This determination also provides a midpoint value between the initial (top plateau) T 2 and the final (bottom plateau) T 2 on a T 2 plasma coagulation curve. See, e.g., FIGS. 2 to 6 . In some embodiments a difference between a first average T 2 value (e.g., of a top plateau) and a second average T 2 value (e.g., of a bottom plateau) is substantially larger than the average standard error of a T 2 measurement using a CPMG sequence. In some embodiments a difference between a first average T 2 value (e.g., of a top plateau) and a second average T 2 value (e.g., of a bottom plateau) is at least 3% of the first T 2 value. In some embodiments a difference between a first average T 2 value (e.g., of a top plateau) and a second average T 2 value (e.g., of a bottom plateau) is at least 5% of the first T 2 value. In certain embodiments a difference between a first average T 2 value (e.g., of a top plateau) and a second average T 2 value (e.g., of a bottom plateau) is at least 10% of the first T 2 value. In particular embodiments a difference between a first average T 2 value (e.g., of a top plateau) and a second average T 2 value (e.g., of a bottom plateau) is at least 13% of the first T 2 value. A calibration factor can be determined by determining the time as described above for one or more samples and determining for the same samples a coagulation time using a commercially available method for determining coagulation (e.g., the start®4 method using the Diagnostica Stago device), and determining the factor by which the times determined using the methods of the present invention have to be multiplied with to obtain the coagulation times determined by the commercially available method. In this case, a data point given by the T 2 value and the corresponding time of T 2 measurement is matched a standard coagulation-time-curve is required to which the determined T 2 value can be compared. As used herein, a “standard coagulation-time-curve” refers to data correlating values of an NMR parameter responsive to coagulation of a sample (e.g., a blood sample, a plasma sample, a fraction of blood in a sample) of one or more subjects, or values mathematically derived from values obtained over time. Data can be, but is not limited to be, in the form of a curve. Graphical presentation of obtained data in terms of a scatter or line plot/graph, for example, with an NMR parameter on the ordinate and time on the abscissa can provide an easy way to compare measured values of an NMR parameter with a corresponding standard coagulation-time-curve. Further, a sample used in determination of a “standard coagulation-time-curve” is taken from one or more subjects that exhibit normal coagulation processes and timing of coagulation processes. The one or more subjects from which samples are used for generation of a standard coagulation time curve can differ but don't have to differ from a test subject for which coagulation is or will be assessed using methods of the present invention. For example, a standard coagulation time curve may be generated using samples obtained from normal healthy patients, and a sample that will be measured and compared to the generated standard coagulation time curve is obtained from a patient requiring assessment of anticoagulant therapy. The sample from the patient is not part of the pool of samples used to generate the standard coagulation time curve. In another example, a standard coagulation-time-curve may be generated using sample(s) of blood of a test subject (e.g., a patient) prior to a procedure or therapy (e.g., a surgery that requires post-surgical administration of an anticoagulant). Coagulation of blood of the patient may be assessed from samples obtained from the patient while the patient is receiving anticoagulant using methods of the present invention and comparing obtained results to a subject's standard coagulation-time-curve determined prior to surgery. In some embodiments one or more standard coagulation time curves are prepared independently in advance and provided as a standard control curve for individual testing of samples for any one or more coagulation times (e.g., prothrombin time (PT), partial thromboplastin time (PTT), activated partial thromboplastin time (APTT), thrombin clotting time (TCT), fibrinogen assa clotting time, activated clotting time (ACT)). In certain embodiments one or more standard coagulation time curves are prepared and provided as part of instructions and reference materials as part of a coagulation test kit. In some embodiments, one or more standard coagulation curves are prepared in advance (e.g., immediately prior to) or in conjunction with (e.g., in parallel) an individual sample preparation and testing. In certain embodiments one or more standard coagulation curves are prepared initially upon first use of a lot of provided reagents, wherein the prepared standard coagulation curve(s) are used for comparison to one or more test sample coagulation curves, and continually used for each of those test samples which utilize the same lot of reagents for sample coagulation tests. A coagulation time can be determined by monitoring elapsed time corresponding to one or more parameters of a coagulation-time-curve including a predetermined magnitude change in the coagulation-time-curve, a percent change from baseline of the magnitude of the coagulation-time-curve, the first derivative of the coagulation-time-curve, the second derivative of the coagulation time curve, higher derivatives of the coagulation-time-curve, to an inflection point, to a steady-state value, and combinations thereof. Parameters can be monitored as a magnitude of elapsed time or as a function of time to enable a calculation or derivation of a characteristic value or characteristic kinetic rate (i.e. half-life of the signal, etc.). If desired, a characteristic value or rate can be compared to a standard or control relating to one or more parameters of a coagulation state of a sample, either simultaneously or sequentially. A standard can take many specific forms, but may be generically described as a data set relating the characteristic value or rate to a coagulation time determined by a standard coagulation instrument (e.g. calibration curve). In some embodiments of the invention, a sample can be mixed with a coagulation reagent before being placed in the test carrier or can interact with a reagent coated on the surfaces of the test carrier. Additionally or alternatively, a sample may be mixed with a coagulation reagent disposed in the test carrier, either before or after a sample is placed in the test carrier. For example, surfaces of a test carrier may be coated with the coagulation reagent or a discrete element that is coated with or includes a coagulation reagent is disposed in the test carrier prior to, at the same time as, or after addition of a sample. Moreover, a test carrier walls can be surface-etched to increase surface area and to enhance surface roughness that can cause fibrin to develop in a sample (e.g., a blood sample (e.g., whole blood, plasma, etc.). Surface roughness may activate or facilitate coagulation of a sample, either in place of or in addition to a coagulation reagent. A test carrier can be a fabrication of any natural, synthetic, porous, non-porous, non-metallic, magnetic susceptibility matched, hydrophobic or hydrophilic material (e.g., plastic (i.e. Delrin or Teflon), glass, Mylar). Furthermore, a test carrier may be of any geometric shape capable of isolating, or accommodating, or absorbing, or containing a volume of solution including capillaries, tubes, hollow channels, conduits, microfluidics, porous membranes, and encapsulations. For example, the carrier may be a glass capillary or tube used for NMR relaxation measurements. A test carrier may accommodate volume samples in the range of 1 picoliter to 1 milliliter, preferably microliters, more preferably 1 to 500 microliters, most preferably 10 to 300 microliters. The present invention also provides methods for monitoring (for example, in real-time) coagulation of a blood sample of a test subject that makes use of measurements of an NMR parameter over time. Comparing obtained values for a monitored NMR parameter with a standard coagulation-time-curve provides information regarding abnormal coagulation events. Monitoring blood coagulation over time provides a clotting profile of a sample and provides information concerning discrete normal or abnormal events that may accompany the coagulation, clotting or lytic process (e.g., clot formation, clot retraction, or clot lysis), as well as providing insight into the overall event. The present invention is useful in distinguishing between platelet-rich and platelet-poor plasma depending on the clotting profile of a sample. The present invention also provides methods for diagnosing an abnormal clotting event in a test subject. At least one test carrier is provided, wherein each test carrier contains a sample (e.g., a blood sample) from a test subject and is placed within a detection volume of a NMR detector. Test data of a NMR parameter responsive to coagulation in the sample of each test carrier is obtained over time, for example, by measuring values of the NMR parameter over time. One or more characteristics of the test data are compared with those of a standard coagulation-time-curve in the NMR parameter responsive to normal coagulation to identify and thereby diagnose an abnormal clotting event in the subject (see, for example, FIG. 3 and FIG. 4 ). Any suitable characteristic associated with the test data can be compared. Examples include overall change of the NMR parameter over time, rate of the NMR parameter change over time, clotting time determined from the NMR parameter change, and fluctuation of the NMR parameter change in the sample prior to coagulation. Preferably, the test data of the NMR parameter are obtained by monitoring values of the NMR parameter over time to provide a coagulation (clotting) profile of the sample. In one specific embodiment of methods of the invention, a plurality of samples (e.g., blood samples) from a test subject are collected at discrete times. In one example, a first test carrier and a second test carrier contain a first sample and a second sample from the same test subject, but collected at discrete times. Difference(s) between the first and second samples in coagulation can be obtained by comparing characteristic(s) of the obtained test NMR data (e.g., clotting profile) between the first and second samples. With such comparison, for example, one can determine if any change is present from (e.g., a first abnormal clotting event diagnosed from a first blood sample over the time period between the first and second blood collection). In another specific embodiment, a first and a second sample are collected from different test subjects. In this example, difference(s) between the first and second samples in coagulation (e.g., clotting profile) can provide information to distinguish between discrete abnormal clotting events relative to the standard coagulation-time-curve (see, for example, FIG. 5 ). The present methods are also useful for providing information concerning discrete events that may accompany the coagulation, clotting or lytic process (e.g., clot formation, clot retraction, or clot lysis), as well as providing insight into the overall event. Provided methods can be useful in distinguishing between platelet-rich and platelet-poor plasma depending on the clotting profile of the sample. The methods can also provide information useful to physicians developing a treatment plan for patients during and following surgery including cardiopulmonary bypass surgery to avoid or mitigate pre-operative, perioperative, and/or post-operative bleeding. A brief summary of the technical elements relating to the principles of the present invention is provided herein. The underlying principle of the present invention for coagulation state measurement and its use in determining coagulation time is based on the assumption of single-exponential decay functions obtained from NMR radiofrequency (RF) echo signals. According to this model for coagulation state determination, an effective T 2 relaxivity change over time is related to a sample coagulation state and inversely proportional to temperature. Provided methods allow measurement of the kinetics of coagulation by monitoring changes in relaxation times. For example, in certain embodiments, measurements (e.g., 10-20 measurements) can be made after mixing a sample and a reagent to initiate coagulation, before coagulation is complete, and coagulation times can be determined from the resulting kinetic curves. In FIG. 1 , an NMR system is depicted to illustrate the principle on which the invention is explained on the basis of several embodiments. The depiction is not intended to limit the invention to a particular embodiment, but serves for the purpose of explaining the illustrative elements of devices utilizing the underlying principles for the measurement of one or more NMR parameter(s) to provide a sample coagulation time. FIG. 1 is a schematic diagram 100 of an NMR system for detection of an echo response of a sample 103 to an RF excitation, thereby determining the coagulation state of the sample and a corresponding coagulation time. In a specific embodiment, a sample 103 within test carrier 104 is placed within the sensitive region of an RF coil 105 of device 100 . Device 100 comprises bias magnets 101 that generate a bias magnetic field B 0 102 through a sample 103 . An RF excitation pulse at the Larmor frequency is applied to a sample using RF coil 105 and RF oscillator 106 . The RF excitation and subsequent series of 180 degree pulses induces what is known in the art as a CPMG echo train. Amplitude of these echos decays as a function of time, which is known as a T 2 relaxation curve. The coil 105 can be configured to act synchronously as an RF antenna to detect the echo signal. RF signal obtained from a coil 105 is amplified by amplifier 107 and processed to determine a change in the relaxation curve in response to the excitation applied to the sample 103 . The detected and processed signal is preferably the T 2 relaxation time. A series of T 2 relaxation times is monitored over a period of time from an initial set of values to a steady set of values. A corresponding coagulation time of the sample can be calculated using a standard data set or a calibration curve for comparison with the series of monitored T 2 relaxation times. In alternative embodiments, various configurations of carrier 104 may be used for coagulation time testing. Other configurations of the bias magnetic field B 0 102 can be applied to sample 103 including, unilateral magnetic fields, low powered magnetic fields, and the earth's magnetic field. In one embodiment, an RF coil 105 is wrapped around the sample carrier 104 . In alternative embodiments, RF coil 105 can be a planar RF coil or other shape and form of RF coil can be used with sample carrier 104 . In certain embodiments, alternative and/or additional reagents can be added to a sample carrier 104 prior or introduced simultaneously with a sample 103 into carrier 104 . Gradient coils 109 can be used to apply discrete, intermittent, or continuous magnetic gradient forces on sample 103 , coagulation reagent 108 , and optional additional and/or alternative regents. For example, T 2 relaxivity measurements of a sample can be taken independent of coagulation measurements described herein to assess viscosity of a sample using magnetic particles. See, e.g., WO2009/026164, the disclosure of which is incorporated herein by reference. Additionally or alternatively, T 2 relaxation rates may be analyzed to ascertain the mechanical integrity of clot formation within a sample over a period of time particularly to identify coagulopathic characteristics of a blood sample. In some embodiments, a coagulation time test is conducted on one or more samples that are “incubated” in a test carrier 104 (e.g., incubating in a test chamber) by maintaining samples at a preferred temperature (e.g., body temperature) for a defined incubation time period. For example, in certain embodiments it may be necessary to incubate sample (e.g., citrated whole blood, plasma, or quality control sample(s)) prior to running measurements (e.g., for ACT test(s)). Blood sample(s) drawn from a patient and immediately placed within the test carrier 104 before the sample has cooled may not need an incubation period and may only need to be maintained at 37° C. Thus, a heating element (e.g., a heat block (not shown)) can be incorporated within device 100 in relation to a carrier 104 . Preferably a heating element (e.g., a heat block) is continuously powered when device 100 is powered in order to maintain a constant temperature (e.g., body temperature, 37° C.) to a test carrier 104 inserted into the RF coil 105 . In certain embodiments, a suitable reagent 108 may be selected to react with a sample (e.g., a blood sample) to facilitate sample coagulation (e.g., for performance of a particular test on a blood sample for determining sample coagulation times, e.g., one of PT, aPTT, TT, and ACT). In some embodiments a suitable reagent 108 may be added to a sample carrier 104 prior or introduced simultaneously with sample 103 into carrier 104 . In some embodiments a coagulation reagent 108 can be included in a sample carrier 104 prior wherein when an added sample 103 is place in carrier 104 , sample reacts with the reagent 108 . In particular embodiments coagulation reagent(s) may be selected from coagulants or activating agents including calcium, kaolin, celite, ellagic acid, glass particles, thrombin, thromboplastin or other coagulation agents described herein and known in the art. In some embodiments, coagulation reagents are selected from one or more coagulating agents selected from a prothrombin time (PT) reagent, a partial thromboplastin time (PTT)/activated partial thromboplastin time (APTT) reagent, thrombin clotting time (TCT) reagent, fibrinogen reagent, an activated clotting time (ACT) reagent, calcium (e.g., calcium chloride)), kaolin, celite, ellagic acid, glass particles, thrombin, and/or thromboplastin. In other embodiments, test carrier 104 may also contain or optionally accommodate additional reagent(s). In some embodiments to counteract any anticoagulant(s) present in a blood sample. For example, during interventional procedures, heparin may be administered to a subject to mitigate coagulation induced by a procedure, in which case neutralizing or deactivating agent(s) (e.g., heparinase, protamine) in test carrier 104 could counteract heparin and return the blood sample to a baseline condition. For example, one test carrier 104 could contain protamine, and another test carrier 104 could be devoid of protamine to perform comparative coagulation time tests. EXAMPLE 1 Coagulation Time Measurement in Plasma Using T 2 Relaxation A Bruker Minispec mQseries (The Woodlands, Tex.) was adapted with pulse sequences for T 2 monitoring in real time. Several effective T 2 measurements made within 30 to 40 seconds and transverse relaxation times of plasma samples were measured every 5 seconds. Coagulation of a sample was induced by addition of calcium chloride to a mixture of reconstituted plasma (CITREX® I lyophilized plasma preparation, BIODATA Corporation, Horsham, PAS) and an aPTT reagent (CEPHALINEX® activated partial thromboplastin time reagent BIODATA Corporation, Horsham, Pa., USA). T 2 measurements were made kinetically on a Bruker MQ minispec using preloaded minispec software with the following CPMG settings: 1. Tau=0.25 2. Number of Points=1000 3. Dummy Echos: 3 4. Recycle Delay: 1 5. 0 dB pulse at 37° C. 6. Receiver gain: 75 7. 1 scan Coagulation time was estimated by curve analysis completed by midpoint determination between the T 2 intial and T 2 final. See FIG. 2 . During coagulation, the relaxation time of the plasma sample decreased steadily until the sample was fully coagulated. See FIG. 2 . The overall change in T 2 observed was about 300 ms. Coagulation time was determined to be about 35 s based on the curve in FIG. 2 . EXAMPLE 2 Coagulation Measurements Using Pooled Normal and Single Donor Abnormal Samples via T 2 Relaxation Real patient plasmas were purchased through George King Bio-Medical and used within 2 hours following thawing. Both normal and abnormal samples were run in duplicate to provide experimental error (averages are shown). Duplicate sampling resulted in a more precise coagulation time compared to the reference (start-4) data. (Note: standard deviation of samples controlled two factors: effective T 2 values, coagulation time). Measurement of changes in T 2 relaxation time over time were taken. Measurements were made kinetically on a Bruker MQ minispec using preloaded minispec software with the following CPMG settings: 1. Tau=0.25 2. Number of Points=1750 3. Dummy Echos: 3 4. Recycle Delay: 1 5. 18 dB pulse at 37° C. 6. Receiver gain: 75 7. 1 scan Curve analysis was completed to generate coagulation times by midpoint determination between the T 2 intial and T 2 final. 2A. For aPTT coagulation measurements 100 μL of patient plasma and 100 μL of aPTT clotting reagent PTT-A (Diagnostica Stago, Parsippany, N.J.) were pre-warmed to 37° C. in a 5 mm NMR tube. 100 μL of calcium chloride pre-warmed to 37° C. was added to the plasma and clotting reagent activating coagulation. See, FIG. 3 and FIG. 5 . The overall change in T 2 observed was about 250 ms for the normal sample, and about 250 ms for the abnormal sample. Coagulation time was determined to be about 50 sec for the normal sample, and about 140 sec for the abnormal sample based on the curve in FIG. 3 . In FIG. 5 , overall change in T 2 observed was about 205 ms for the normal sample, 300 ms for abnormal sample 1, and about 95 ms for abnormal sample 2. Coagulation time was determined to be about 70 sec for the normal sample, and about 100 sec for the abnormal sample and about 90 sec for abnormal sample 2 based on the curve in FIG. 5 . 2B. For PT coagulation measurements 100 μL of patient plasma and 200 μL of Neoplastine CI Plus (Diagnostica Stago, Parsippany, N.J.) pre-warmed to 37° C. were mixed activating coagulation. See FIG. 4 . The overall change in T 2 observed was about 150 ms for the normal sample, and about 160 ms for the abnormal sample. Coagulation time was determined to be about 19 sec for the normal sample, and about 67 sec for the abnormal sample based on the curve in FIG. 4 . EXAMPLE 3 Correlation Between Coagulation Method Results Obtained Using a Method of the Present Invention and Results Obtained with a Commercial Bench-top Coagulation Instrument For aPTT measurements, 100 μL of patient plasma and 100 μL of PTT-A (Diagnostica Stago) were pre-warmed to 37° C. in a 5 mm NMR tube. 100 μL of calcium chloride pre-warmed to 37° C. was added to the plasma and clotting reagent activating coagulation. For PT measurements 100 μL of patient plasma and 200 μL of Neoplastine CI Plus (Stago Diagnostica, Parsippany, N.J.) pre-warmed to 37° C. were mixed activating coagulation. Measurements were made kinetically on a Bruker M Q minispec using preloaded minispec software with CPMG parameters described in Example 2. Curve analysis to generate coagulation times was completed by midpoint determination between the T 2 intial and T 2 final. Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPPT) of plasma samples were measured using a Bruker Minispec mQseries and a commercial bench-top coagulation instrument from Diagnostica Stago (Parsippany, N.J.), called the Start®4. FIG. 6 shows a correlation plot representing a graphical comparison of these two methods. As is known in the art, a subtraction factor was applied to time measured by T2 Biosystems to provide a correlation with the Diagnostica Stago Start®4. This subtraction factor was determined by subtracting a fixed value which resulted in all normal coagulation values derived with the NMR instrument to be in a clinically normal range. The correlation data points are very close to the plot diagonal, indicating excellent correlation of the results obtained using two very different approaches for measuring coagulation times. While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

The invention relates to detecting coagulation and coagulation-related activities including agglutination and fibrinolysis of samples. More particularly the invention relates to methods and apparatus for monitoring coagulation and/or obtaining a coagulation time of a sample using NMR-based detectors.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 09/838,678, filed Apr. 19, 2001 (now U.S. Pat. No. 7,210,025), which claims priority from the provisional application designated Ser. No. 60/198,300, filed Apr. 19, 2000 and entitled “Automatic and Transparent Hardware Conversion of Traditional Control Flow to Predicates”. These applications are hereby incorporated by reference. GOVERNMENT LICENSE This invention was made with government support under Grant Nos. MIP-9708183, EIA-9729839, and DUE-9751215, awarded by the National Science Foundation. The government has certain rights in this invention. TECHNICAL FIELD The invention relates to the field of computing devices, and in particular to a computing device that includes automatic and transparent hardware conversion of traditional control flow predicates. BACKGROUND OF THE INVENTION Computer programs typically use traditional control flow constructs to determine when and if instructions in the program are executed. Such constructs include “if-then-else” statements and various looping statements such as: “while (condition is true){ . . . }”, “for(i initialized to 1; while i<10; increment i every loop iteration){ . . . }” and “do i=1 to 10 . . . enddo”. The majority of such control statements are realized with machine-level instructions called branches, and most of these are conditional branches. Branches are used as follows. Most computers employ a model of computation using a pointer to the code of the program it is executing. The pointer is provided by a program counter (PC) that contains the address of the machine instruction the computer is currently executing. Every time an instruction is executed, the default action is to increment the program counter to point to the next instruction to be executed. Most useful programs employ branches to conditionally modify the contents of the program counter to point to other places in a program, not just the next instruction. Therefore, a conditional branch has the semantics: if (condition is true) then load the program counter with a (specified) value. A well-known alternative to conditional branches is the use of predicates. A predicate is typically a one-bit variable having the values true or false; it is usually set by a comparison instruction. In this model every instruction has a predicate as an additional input. The semantics is that the instruction is only effectively executed (i.e., its output state changed) if the predicate is true. An example of equivalent classic control flow and modern predication is as follows. Classic code: Predicated code: 1. if (a = = b) { 1. Prod = (a = = b); //Prod set to true if a equals b. 2. z = x + y; 2. IF (Pred) THEN z = x + y; //Operations performed only 3. w = a + b; } 3. IF (Pred) THEN w = a + b; // if Pred true. 4. // later instructions: 4. // later instructions: NOT dependent // all dependent on 1. on 1. In traditional computers, all instructions following a branch are dependent on the branch and must wait for the branch to execute before executing themselves. This has been demonstrated to be a significant barrier in realizing much parallelism within a program, thus keeping performance gains low. However, with predication, only the instructions having the equivalent predicate as an input are dependent on the branch-remnant (the comparison operation). In the example and, in general, this means the instructions after the predicated instructions are now independent of the branch-remnant and may be executed in parallel with instructions before the branch-remnant, improving performance. Current approaches to using predication use visible and explicit predicates. The predicates are controlled by the computer user and they use storage explicitly present in the computer's instruction set architecture (similar to regular data registers or main memory). They are explicit since there is at least a single 1-bit predicate hardware register associated with each instruction. The most extreme example of this is the IA-64 (Intel Architecture-64 bits) architecture. The first realization of this architecture is the Itanium (formerly Merced) processor, due to be on the market in the year 2000. Itanium has 64 visible-explicit predicate registers. See for example the document by the Intel Corporation, entitled “IA-64 Application Developer's Architecture Guide ”. Santa Clara, Calif.: Intel Corporation, May 1999. Order Number: 24188-001, via www.intel.com. The predicates cannot be effectively used when the processor executes traditional IA-32 (x86) machine code. Therefore, billions of dollars of existing software cannot take advantage of Itanium without modification. Other types of microprocessors have similar constraints to x86 processors. That is, predicates are not currently in their instruction set, so they cannot take advantage of predication techniques. It is possible to predicate just a subset of the instructions of a processor, but then the benefits of predication are much less. Full predication is preferred. In prior work we devised a method for realizing an equivalent to full predication called minimal control dependencies. (MCD). See for example, the papers by: (i) A. K. Uht, “Hardware Extraction of Low-Level Concurrency from Sequential Instruction Streams”, PhD thesis, Carnegie-Mellon University, December 1985, available from University Microfilms International, Ann Arbor, Mich., U.S.A; (ii) A. K. Uht, “An Efficient Hardware Algorithm to Extract Concurrency From General-Purpose Code,” in Proceedings of the Nineteenth Annual Hawaii International Conference on System Sciences , University of Hawaii, in cooperation with the ACM and the IEEE Computer Society, January 1986; and (iii) A. K. Uht, “A Theory of Reduced and Minimal Procedural Dependencies,” IEEE Transactions on Computers , vol. 40, pp. 681-692, June 1991. Each of these papers is incorporated herein by reference. MCD produced substantial performance gains, especially when coupled with another performance-enhancing technique of ours called disjoint eager execution, disclosed in the paper by A. K. Uht and V. Sindagi, entitled “Disjoint Eager Execution: An Optimal Form of Speculative Execution,” in Proceedings of the 28 th International Symposium on Microarchitecture ( MICRO -28), pp. 313-325, IEEE and ACM, November/December 1995. This paper is also incorporated herein by reference. MCD can be considered to have hidden and implicit predicates, in that the predicates are not visible to the user, nor are they explicitly present in the processor. However, MCD has disadvantages when compared to predication such as a high hardware cost (e.g., more logic gates and storage) with relatively complex hardware. In particular, j-by-j diagonal bit matrices are required, where j is the number of instructions in the instruction window (those instructions currently under consideration for execution by the processor). In a high-ILP machine, j might be 256 or more, leading to a cumbersome 32,000 or more bit diagonal matrix. Further, all of the bits need to be accessed and operated on at the same time, leading to a very complex and potentially slow hardware layout. Lastly, setting the contents of the matrix when instructions are loaded into the processor is also costly and potentially slow. Therefore, there is a need for an automatic and transparent hardware conversion of traditional control flow predicates. SUMMARY OF THE INVENTION Briefly, according to an aspect of the present invention, a computing device that provides hardware conversion of flow control predicates associated with program instructions executable within said computing device, detects the beginning and the end of a branch domain of said program instructions, and realizes the beginning and the end of said branch domain at execution time, for selectively enabling and disabling instructions within said branch domain. These and other objects, features and advantages of the present invention will become apparent in light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial illustration of various branch arrangements; FIG. 2 is a block diagram illustration of predicate-assignment hardware; FIG. 3 illustrates a hidden-explicit predication example for disjoint branches; FIG. 4 illustrates a hidden-explicit predication example for nested branches; FIG. 5 illustrates a hidden-explicit predication example for overlapped branches; and FIG. 6 illustrates a hidden-explicit predication example for mixed branches. DETAILED DESCRIPTION OF THE INVENTION Hidden-explicit predicates are realized by the invention; the predicates are not visible to the user and thus may be implemented in any processor architecture, and the predicates occupy explicit hardware register bits in the processor, reducing cost and complexity. There are two parts to the invention: the predicate-assignment part, taking place when instructions are loaded into the processor, and the predicate-use part, taking place at instruction execution time. Nomenclature: A branch's domain includes the instructions occurring between the branch and the branch's target. Thus, the branch controls the execution of the instructions within its domain. If the branch's condition evaluates true the branch is taken, and the instructions in its domain are not executed. If the branch's condition evaluates false, the branch is not taken and the instructions in the branch's domain are allowed to execute. Multiple branch domains can be arranged in a number of different ways, each of which are combinations of the three basic arrangements: disjoint, nested and overlapped, as shown in FIG. 1 . For full predication all possible combinations of these arrangements must be handled correctly. The invention does this. Key Ideas The predicate-assignment hardware detects the beginnings and ends of branch domains. The predicate-use hardware employs this information to realize the beginnings and ends of domains at execution time, performing the appropriate enabling and disabling of instructions in domains. In general, as each new domain is encountered during code execution, a new condition is placed on the execution of the code within the new domain. If the branch condition of the domain's branch is bc i , and the predicate of the code before the branch is p r then the effective predicate p e of the new code in the new branch's domain is computed as: p e = bc i ·p r When a domain is exited (upon reaching the corresponding branch's target instruction) the effect of the corresponding branch must be nullified, in other words bc i should have no effect on the execution of the following code. This is achieved by effectively OR-ing the opposite value of the branch condition with the current predicate; in other words, the following is effectively computed for the code after the branch domain: p e2 =p e +( bc i ·p r )=( bc i ·p r )+( bc i ·p r )= p r This logic is realized by the combined operation of the predicate-assignment and predicate-use hardware. Predicate-Assignment Hardware and Operation The predicate-assignment hardware assigns predicate and canceling predicate addresses to instructions as they are loaded into the processor's load buffer and before the buffer contents are sent to the instruction window for execution. The assignment is performed by detecting domain entries (branches) and exits (targets). The basic hardware structure is a branch tracking stack or buffer as shown in FIG. 2 . FIG. 2 is a block diagram illustration of predicate-assignment hardware, that includes a stack that is associatively addressed by the current value of the ilptr (instruction lead pointer). The predicate address of the branch corresponding to a target address match with the ilptr is output from the hardware and used to augment the state of the instruction being loaded. The p r register holds the address of the current region's predicate. p r may point to the predicate from either a branch or a branch target. In the context of the present invention, the term “stack” is used in its generic sense; it is contemplated that any kind of temporary storage may be used. Each entry (row) in the stack corresponds to one branch. Typically, but not necessarily, a branch is on the stack only while the instruction load pointer ilptr value is within the branch's domain. The following fields compose each entry: 1. address of predicate corresponding to the branch p b ; 2. address of canceling predicate corresponding to the branch cp b ; in practice this may be derived from the branch's predicate address, so no explicit entry would be needed for canceling predicate addresses; 3. target address of the branch ta b ; and 4. valid bit flag v b ; true while the target of the corresponding branch has not yet been reached; the stack entry may be reclaimed and reused when the valid bit is false. A branch is placed on the stack when it is encountered by the ilptr and is removed when its target is reached. In the case of overlapped branches, the target for a branch may be reached before a prior branch's target has been reached. In this case the overlapped branch has its valid bit flag v bit cleared, and is removed from the stack when convenient. The comparators look for a match between the instruction load pointer ilptr and the target addresses. If there is a match, it indicates that the instruction just loaded is the target of the matching branch (multiple matches will be considered later). The current canceling predicate address cp T is set equal to the canceling predicate address of the matching branch. The current canceling predicate address cp T is entered into the canceling predicate address field of the instruction being loaded. Out-of-Bounds Branches: Branches with targets inside the window have been considered. It is also possible that a branch in the window may jump to a point not yet encountered by the predicate-assignment hardware. Therefore, the hardware illustrated in FIG. 2 is augmented with additional circuitry to handle these out-of-bounds branches. The new circuitry includes primarily another set of comparators for performing associative lookups on field “p”. The technique is as follows. A candidate branch for execution supplies its predicate address to the tracking buffer circuitry. The address is used as a key to perform a lookup on the “p” field. If a branch's domain is wholly contained in the window, then the branch will not have a valid entry in the buffer. Therefore, if the candidate branch does obtain a valid match, it is an out-of-bounds branch. The branch's target address is then read from the corresponding TA tracking buffer entry. The latter reduces storage costs, as target addresses need not be stored in the window, and also simplifies operation because target addresses do not need to be read from the window. Predicate-Use Hardware and Operation The Predicate-Use (PredU) hardware augments the state and operations of instructions held in the processor's instruction window. None of the Predicate-Use hardware is visible to the user (i.e., it does not appear in the processor's instruction set architecture) and thus may be applied to any type of processor. The overall effect of the Predicate Use hardware is to chain predicate sources and sinks so as to both enforce the functionality of the system and to keep the hardware cost low. The alternative to chaining the predicates is to have many predicate inputs for each instruction, which would be costly in terms of additional instruction state and therefore also more complex in operation. The Predicate Use hardware and operations differ depending on whether the instruction is a branch or an assignment statement. Both cases are now considered. Branch PredU Hardware and Operations: The output predicates are evaluated or re-evaluated whenever the input predicate or branch condition becomes available or changes value, resp. Input: p r —predicate of region, same as input predicate p in . Outputs: branch predicate: p out = bc ·p r branch canceling predicate: cp out =bc·p r bc is the Branch Condition of this branch, and has the values true (1) and false (0). It is set as the result of some comparison test operation such as: A<B. The comparison may be performed either as part of the branch's execution or as part of a prior instruction, depending on the processor architecture. Execution Enabling Predicate: The branch executes whenever its inputs are available or change value. Therefore, all branches in the instruction window may execute in parallel and out-of-order. Assignment Statement PredU Hardware and Operation: Assignment statements also have predicate inputs and outputs. These are used both for predicate-chaining and predicate-canceling. Recall that predicate-canceling occurs when a branch domain is exited. Inputs: p r —predicate of region; same as input predicate p in ; and cp T —canceling predicate of targeting branch, if any; same as cp in . Output: p out =p r +cp T =p in +cp in p out is computed independently of the rest of the assignment statement's execution and computations. Execution or Assignment Enabling Predicate: p 1 —same as output: p 1 =p in +cp in The assignment instruction may modify its traditional sinks when p 1 is true. Such sinks are the results of the regular operations of the assignment statement, e.g., if the instruction is: A=B+C then A is a traditional sink and is written if the instruction's predicate evaluates true. Case: Multiply-Targeted Instructions There is a not-so-special case that can often arise in code and that we have not yet addressed. This is the case when an instruction is the target of more than one branch. In this scenario the hardware as described so far will not work, as it is only suitable for an instruction being the target of no more than one branch. There are two solutions that can be employed to handle the multiple-target case. The first is to provide multiple canceling predicate fields for each instruction. This will cost more, but may be suitable for a small number of canceling predicates. However, we must handle the case when an instruction is the target of many branches (this is possible in many machines, although perhaps not likely). A second solution is to insert a dummy No-Op instruction into the window after the current instruction if the instruction runs out of canceling predicate fields. The No-Op's canceling predicates can then be used in addition to the original instruction's. Since any number of No-Ops can be inserted, any number of branches targeting the same instruction can be handled. Of course, a price is paid for a “wasted” slot in the instruction window for each No-Op instruction added. A suitable number of canceling predicate fields for one instruction may be empirically determined. It is likely that both solutions will be used in a typical processor. Case: Branch is a Target of Another Branch It is also possible, if not likely, that code will contain a branch that is the target of another branch. This scenario is readily handled by employing all of the predicate and canceling predicate logic in the branch, such that it appears as BOTH a branch and an assignment statement. The canceling predicate output of such an instruction is the same as that of an un-targeted version of the branch. The predicate output combines the functions of the branch predicate and the assignment statement predicate, with the branch portion using the assignment portion as its region predicate input: p out = bc ·( p r +cp T )= bs ·( p in +cp in ) This works because the assignment portion effectively (logically) takes place before the branch. EXAMPLES We now present four examples to illustrate the operation of the hidden-explicit predicate system. The examples cover the following cases: 1. two disjoint branches, FIG. 3 (also covers the cases of straight-line code and a single branch); 2. two nested branches, FIG. 4 . 3. two overlapped branches, FIG. 5 . 4. three branches with a combination of nesting and overlapping, FIG. 6 . All of the examples have the same format. In the code column: “I” instructions are assignment statements, and “B” instructions are branches. The branch domains are shown with arrowed lines. Each example can be followed by first going down the predicate-assignment table entries, in order, as the instructions would be loaded. Using the tracking stack, this results in the predicate addresses shown in the p in and cp in columns being generated and entered into the corresponding instruction's fields in the instruction window. Next, the predicate-use table entries may be examined to see how the predicates are evaluated at run-time, how their values are chained and how branch domains are effectively exited. For an example of the latter, refer to FIG. 3 and look at the p 1 entry for the assignment instruction at address 400 . Although it has predicate inputs, their values cancel each other out, p 1 is effectively “1” and thus the instruction is always enabled for execution, as far as branches are concerned. This is correct, since it is outside the domains of all of the branches in the code example. Although the present invention has been shown and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the form and detail thereof, may be made therein, without departing from the spirit and scope of the invention.

A computing device that provides hardware conversion of flow control predicates associated with program instructions executable within the computing device, detects the beginning and the end of a branch domain of the program instructions, and realizes the beginning and the end of the branch domain at execution time, for selectively enabling and disabling instructions within said branch domain.

TECHNICAL FIELD [0001] The present invention pertains to devices for cutting and crimping cables, and more particularly to devices which can make straight cuts and proper crimps at a work site. BACKGROUND [0002] In many situations where cables, also known as “wire ropes”, are used, the cables must be cut at a work site, and two or more sections of cable must be crimped together. Crimping is generally accomplished by inserting the ends of two or more cables into a deformable cylindrical housing known as a “sleeve”. The sleeve is then crimped by crushing the sleeve tightly against the cables contained therein. A large amount of force is required both to cut the cables and to crimp the sleeve around two or more cable sections to join them together. [0003] There exist prior art devices that can be used to both cut cables and crimp two or more sections of cable together. For example, U.S. Pat. No. 4,558,584 discloses a combination cable crimper and cutter with a pair of crimping jaws that are urged together by a piston. A cutter is mounted on one of the crimping jaws opposite a cutter anvil on the side of the frame. [0004] One problem with such prior art devices is that in both cutting and crimping operations, particularly in applications such as logging where the cables are wrapped around an irregularly shaped bundle of logs, the cables must be cut or crimped at a point where they are flush against a surface. As one skilled in the art will appreciate, a device similar to that disclosed in U.S. Pat. No. 4,558,584 that has the cutter on the side is not well suited for cutting cables that are flush against a surface. [0005] Another problem with prior art cutting and crimping devices is that it can be difficult to keep the device properly oriented with respect to the cable during cutting and crimping. In order to achieve a straight cut the cutting blades of a cutter must be placed, by the user, in the correct position relative to the cable. Likewise, in order to achieve a proper crimp the crimping portions of a crimper must be placed, by the user, in the correct position relative to the sleeve and cables therein. [0006] There exists a need for cutting and crimping devices which are well suited for cutting cables that are flush against a surface, and which facilitate proper orientation with respect to the cable during cutting and crimping. SUMMARY OF INVENTION [0007] The invention provides a cutting and crimping device comprising a frame with a front end and a back end, the frame comprising a protrusion on the front end, the protrusion having a first crimping portion and a first cutting portion on opposed sides thereof, a cutting arm with a front end and a back end, the cutting arm pivotally coupled to the frame on one side thereof, the cutting arm comprising a second cutting portion on its front end, a crimping arm with a front end and a back end, the crimping arm pivotally coupled to the frame on an opposite side thereof, the crimping arm comprising a second crimping portion on its front end, and, an actuator coupled to the back ends of the cutting and crimping arms, the actuator operable to move the cutting and crimping device between an open position wherein the front ends of the arms are separated from the protrusion by a maximum distance, and a closed position wherein the front ends of the cutting and crimping arms are separated from the protrusion by a lesser distance. [0008] The actuator may comprise a push rod having a front end and a back end, and a block, with the block attached to the front end of the push rod. The actuator may be coupled to the back end of the cutting arm by a cutting arm link, with a back end of the cutting arm link being pivotally attached to the block, and a front end of the cutting arm link being pivotally attached to the back end of the cutting arm. The actuator may be coupled to the back end of the crimping arm by a crimping arm link, with a back end of the crimping arm link being pivotally attached to the block, and a front end of the crimping arm link being pivotally attached to the back end of the crimping arm. The cutting arm link may be longer than the crimping arm link. [0009] The second cutting portion may comprise a reversible cutting blade. The protrusion may comprise a recess sized slightly larger than the first cutting portion, and the first cutting portion comprises a cutting edge opposite a rounded edge, with the rounded edge positioned in the recess. [0010] The first and second crimping portions may comprise rounded notches. [0011] The cutting and crimping device may further comprise a drive means connected to the back end of the push rod, the drive means operable to urge the push rod forward. [0012] The cutting and crimping device may further comprise a handlebar attached to the frame. [0013] The cutting and crimping device may further comprise a grip attached to the frame. The grip may comprise a control button operable to control the drive means. [0014] The actuator may further comprise a plate attached to the back end of the push rod, and may even further comprise a spring between the plate and the frame, the spring biasing the cutting and crimping device to the open position. BRIEF DESCRIPTION OF DRAWINGS [0015] [0015]FIG. 1 shows a longitudinal sectional view of a cutting and crimping device according to a preferred embodiment of the invention, in an open position. [0016] [0016]FIG. 2 shows the cutting and crimping device of FIG. 1 in a closed position. [0017] [0017]FIG. 3 shows a perspective view of the cutting and crimping device of FIG. 1 coupled to a drive means. [0018] [0018]FIG. 4 shows a side elevation view of the frame of the cutting and crimping device of FIG. 1 with a grip attached thereto. DESCRIPTION [0019] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense. [0020] [0020]FIG. 1 shows a cutting and crimping device 10 according to a preferred embodiment of the invention. Cutting and crimping device 10 comprises frame 12 with front end 14 and back end 16 . Frame 12 is tapered towards front end 14 , and defines window 13 near front end 14 , in order to reduce the overall weight of cutting and crimping device 10 . Frame 12 further defines square windows 15 near back end 16 . Square windows 15 not only serve to reduce the overall weight of cutting and crimping device 10 , but also facilitate maintenance and servicing of cutting and crimping device 10 , as described below. Frame 12 may further comprise threaded holes 66 on flat portion 68 , as described below with reference to FIG. 4. [0021] Frame 12 comprises protrusion 20 at front end 14 . Protrusion 20 comprises cutting portion 22 on one side thereof, and crimping portion 24 on an opposite side thereof. An actuator 30 is operably connected to back end 16 . [0022] Throughout the description “forward” means the direction from actuator 30 is connected, towards protrusion 20 . The “cutting side” means the side of cutting and crimping device 10 on which cutting portion 22 of protrusion 20 is located, and the “crimping side” means the side of cutting and crimping device 10 on which crimping portion 24 of protrusion 20 is located. [0023] Cutting arm 40 is pivotally attached to frame 12 on the cutting side at a position between front end 14 and back end 16 by pivot bolt 17 . The precise position at which cutting arm 40 is attached to frame 12 will depend on the expected primary use of cutting and crimping device 10 . The larger the diameter of a typical cable which cutting and crimping device 10 will be expected to be used to cut, the farther back the position at which cutting arm 40 is attached to frame 12 should be. [0024] Cutting arm 40 comprises cutting portion 42 on front end 44 thereof. Cutting recess 26 is defined between cutting portion 42 on front end 44 of cutting arm 40 and cutting portion 22 on protrusion 20 . Cutting arm 40 may optionally comprise lubrication channel 45 for lubricating its pivotal coupling with frame 12 . Back end 46 of cutting arm 40 is coupled to be driven by actuator 30 , as described below. [0025] Cutting portions 22 and 42 preferably comprise cutting blades 23 and 43 , respectively. Cutting blade 23 preferably comprises cutting edge 21 and rounded edge 25 . Cutting blade 23 is secured to protrusion 20 by pin 27 , and is located within recess 29 . Recess 29 is sized larger than cutting blade 23 to provide room for cutting blade 23 to pivot slightly about pin 27 , which allows for improved cutting of cables, as described below. Cutting blade 43 is attached to front end 44 of cutting arm 40 by pin 47 . Cutting blade 43 is preferably reversible so that when one cutting edge is worn out the user can flip cutting blade 43 over and use a fresh cutting edge. [0026] Crimping arm 50 is pivotally attached to frame 12 on the crimping side at a position between front end 14 and back end 16 by pivot bolt 19 . The precise position at which crimping arm 50 is attached to frame 12 will depend on the expected primary use of cutting and crimping device 10 . The larger the diameter of a typical sleeve which cutting and crimping device 10 will be used to crimp, the farther back the position where crimping arm 50 is attached to frame 12 should be. Crimping arm 50 comprises crimping portion 52 on front end 54 thereof. Crimping recess 28 is defined between crimping portion 52 on front end 54 of crimping arm 50 and crimping portion 24 on protrusion 20 . Crimping arm 50 may optionally comprise lubrication channel 55 for lubricating its pivotal coupling with frame 12 . Back end 56 of crimping arm 50 is coupled to be driven by actuator 30 , as described below. [0027] Crimping portions 24 and 52 preferably comprise rounded notches. Preferably the notches have a curvature which is similar to the curvature of a sleeve of the size expected to be crimped. [0028] In the embodiment shown in FIG. 1, actuator 30 comprises push rod 32 with block 34 attached to the front thereof. Frame 12 defines aperture 18 in the back thereof, through which push rod 32 is slidably inserted. Aperture 18 is not large enough to allow block 34 to pass therethrough, so that push rod 32 and block 34 are retained within frame 12 . Frame 12 has stop bolt 36 through a central portion thereof. Stop bolt 36 is located directly in front of aperture 18 , so that when push rod 32 is pushed forward, block 34 will abut stop bolt 36 . The range of motion of actuator 30 is thereby constrained between a rearward or “open” position (FIG. 1) wherein block 34 abuts the back of frame 12 adjacent aperture 18 , and a forward or “closed” position (FIG. 2) wherein block 34 abuts stop bolt 36 . In the FIG. 1 embodiment, actuator 30 further comprises plate 38 attached to the back of push rod 32 . Spring 39 is positioned between frame 12 and plate 38 to bias cutting and crimping device 10 towards the open position. [0029] Cutting arm 40 is coupled to actuator 30 by cutting arm link 48 . One end of cutting arm link 48 is pivotally attached to the cutting side of block 34 by first cutting link pin 47 , and the other end of cutting arm link 48 is pivotally attached to the back end 46 of cutting arm 40 by second cutting link pin 49 . Likewise, crimping arm 50 is coupled to actuator 30 by crimping arm link 58 . One end of crimping arm link 58 is pivotally attached to the crimping side of block 34 by first crimping link pin 57 , and the other end of crimping arm link 58 is pivotally attached to the back end 56 of crimping arm 50 by second crimping link pin 59 . In the preferred embodiment shown in FIGS. 1 and 2, cutting arm link 48 is longer than crimping arm link 58 , in order to allow crimping recess 28 to be directly in front of push rod 32 . Crimping recess 28 is preferably in line with push rod 32 to provide added force and stability while crimping, as crimping generally requires more force than cutting. [0030] Preferably, both cutting arm 40 and crimping arm 50 may be removed or replaced without fully dismantling cutting and crimping device 10 . To remove cutting arm 40 , a user removes pivot bolt 17 which extends through frame 12 . Second cutting link pin 49 may be removed by positioning cutting arm link 48 appropriately with respect to square window 15 on the cutting side of cutting and crimping device. To remove crimping arm 50 , a user removes pivot bolt 19 which extends through frame 12 . Second crimping link pin 59 may be removed by positioning crimping arm link 58 appropriately with respect to square window 15 on the crimping side of cutting and crimping device. [0031] In operation, cutting and crimping device 10 begins in an open position, as shown in FIG. 1. In the open position, actuator 30 is in its rearward position, with block 34 abutting the back of frame 12 adjacent aperture 18 . In the open position, back ends 46 and 56 of cutting arm 40 and crimping arm 50 are held, by cutting arm link 48 and crimping arm link 58 , respectively, at a position wherein their separation from stop bolt 36 is at a minimum. Accordingly, in the open position, the separation between cutting portion 42 on front end 44 of cutting arm 40 and cutting portion 22 on protrusion 20 , and the separation between crimping portion 52 on front end 54 of crimping arm 50 and crimping portion 24 on protrusion 20 are at a maximum. [0032] When cutting and crimping device 10 is in the open position, cutting recess 26 may be positioned to cut a cable by placing cutting portion 22 of protrusion 20 against the cable, or crimping recess 28 may be positioned to crimp a sleeve containing two or more sections of cable by placing crimping portion 24 of protrusion 20 against the sleeve, or both. Once the cable or sleeve or both are in place, cutting and crimping device 10 may be moved toward a closed position as shown in FIG. 2 by urging push rod 32 forward with a suitable drive means 60 (see FIG. 3). [0033] If a cable is positioned in cutting recess 26 as cutting and crimping device 10 moves toward the closed position shown in FIG. 2, cutting blades 23 and 43 will cut the cable. Cutting blade 23 has room to pivot slightly in recess 29 , as described above, so that cutting blades 23 and 43 may be parallel at the end of the cutting stroke. This reduces unraveling of the cut ends of the cable, which can make it difficult for the ends to be fit into a sleeve. Preferably, once the cutting stroke is complete and cutting and crimping device 10 is in the closed position, cutting blades 23 and 43 will be separated by a distance of less then 1 mm, and more preferably by a distance of approximately 0.2 mm. [0034] As one skilled in the art will appreciate, since cutting portion 22 and crimping portion 24 on protrusion 20 remain stationary as push rod 32 is urged forward, there is less potential for user error than in prior art cutting and crimping devices where there are two moving parts which must be aligned with the cables. Stationary protrusion 20 makes it possible for a user to simply rest the appropriate portion (cutting or crimping) of protrusion 20 against the cable or cables to be cut or crimped, and activate the drive means. There is no need to balance the device so that the cable or cables are separated from each of two moving parts by an equal distance. This makes it easier for a user to achieve even crimping, wherein a single sleeve is crimped at a number of evenly spaced locations, which results in a stronger joining of the sections of cables within the sleeve. [0035] [0035]FIG. 3 shows cutting and crimping device 10 with drive means 60 coupled to the back thereof. Handlebar 62 may be attached to cutting and crimping device 10 to facilitate operation of cutting and crimping device 10 by a user. Drive means 60 may comprise a hydraulic cylinder, a pneumatic cylinder coupled to an air compressor, or any other apparatus capable of urging push rod 32 forward with sufficient force. [0036] [0036]FIG. 4 shows frame 12 of cutting and crimping device 10 with grip 64 attached to flat portion 68 , and drive means 60 coupled to back end 16 . Frame 12 comprises threaded holes 66 in flat portion 68 to facilitate attachment of grip 64 to frame 12 by screws 69 or the like. Preferably, there are four threaded holes 66 on each side of frame 12 , so that grip 64 may be attached to either side of frame 12 . Grip 64 may comprise control button 70 which is connected by control wire 72 to control the operation of drive means 60 . [0037] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

A cutting and crimping device comprising a frame with a front end and a back end, the frame comprising a protrusion on the front end, the protrusion having a first crimping portion and a first cutting portion on opposed sides thereof, a cutting arm with a front end and a back end, the cutting arm pivotally coupled to the frame on one side thereof, the cutting arm comprising a second cutting portion on its front end, a crimping arm with a front end and a back end, the crimping arm pivotally coupled to the frame on an opposite side thereof, the crimping arm comprising a second crimping portion on its front end, an actuator coupled to the back ends of the cutting and crimping arms, the actuator operable to move the cutting and crimping device between an open position wherein the front ends of the arms are separated from the protrusion by a maximum distance, and a closed position wherein the front ends of the cutting and crimping arms are separated from the protrusion by a lesser distance.

CROSS REFERENCE OF RELATED APPLICATION This is a U.S. National Stage under 35 U.S.C 371 of the International Application PCT/CN2013/000686, filed Jun. 8, 2013, which claims priority under 35 U.S.C. 119(a-d) to CN 201310048476.8, filed Feb. 7, 2013. BACKGROUND OF THE PRESENT INVENTION 1. Field of Invention The present invention relates to a compound, and more particularly to a hydroxysafflor yellow A sodium compound, and a preparation method as well as medicinal application thereof. The present invention also relates to a field of natural pharmaceutical chemistry. 2. Description of Related Arts Chinese medicine safflower is dried flower of Carthamus tinctouius L., which is a common Chinese medicine for activating blood and dissipating blood stasis, and is applicable for treating blood circulation disorders such as coronary heart disease and angina pectoris. Hydroxysafflor yellow A is a compound with a mono-chalcone glycoside structure, and is a water-soluble portion of the safflower with the most effective pharmacological effect, which can inhibit platelet aggregation and release induced by platelet activating factors, and competitively inhibit combination of the platelet activating factor and the platelet receptor. Therefore, the hydroxysafflor yellow A is an effective ingredient of the safflor yellow for activating blood and dissipating blood stasis. According to research results, the hydroxysafflor yellow A has many pharmacological effects on cardiovascular such as anticoagulant, promoting fibrinolysis, anti-thrombosis, and improving microcirculation. The conventional technologies have disclosed the hydroxysafflor yellow A, a various of extraction, separation and purification methods thereof, and hydroxysafflor yellow A injection (comprising freeze-dried powder injection). However, a purity and stability of the conventional hydroxysafflor yellow A products are not sufficient. Judging from the purity of the conventional safflor yellow, the impurity content is basically above 10%. Furthermore, structure and property of the impurity are indefinite, and quality is not completely controllable. And impurity spectrums of the safflor yellow extracted from the safflower are not consistent. Chinese patent application CN102675379A disclosed a method for extracting refined hydroxysafflor yellow A from safflower, and particularly disclosed five steps: extracting from safflower; purifying by alkalescent ion-exchange resin; purifying by macroporous resin with medium chemical polarity; purifying by nonpolar macroporous resin; and freeze-drying; wherein a content of the hydroxysafflor yellow A is above 80%, a turnover rate is above 20%. Chinese patent applications CN101195647A, CN101215307A and CN1475272A disclosed a method for extracting refined hydroxysafflor yellow A from safflower, wherein a content of the hydroxysafflor yellow A is above 90%. However, because stability of the hydroxysafflor yellow A is not sufficient, the purity thereof will decrease after long-time storage, and the medicinal effect is decreased, which leads to medication safety problem of the hydroxysafflor yellow A. Medicinal research mainly focuses on medicine safety, effectiveness, stability and controllability, none of the four aspects can be omitted. Because the safflor yellow injection produced and clinically utilized is pharmacodynamically tested and clinically evaluated, safety and effectiveness of the hydroxysafflor yellow A compound has been proven. However, due to the extraction process of hydroxysafflor yellow A and compound stability, the impurity content is basically above 10% according to the purity of the raw material of the hydroxysafflor yellow A which is commercially available. Furthermore, structure and property of the impurity are indefinite, and quality is not completely controllable. And impurity spectrums of the safflor yellow extracted from the safflower are not consistent. Therefore, stability and purity of the effective ingredients of the conventional hydroxysafflor yellow A medicine, especially injection, are still the main restrict or influence of safety and improvement of quality controllability. SUMMARY OF THE PRESENT INVENTION For overcoming disadvantages of conventional technologies, a compound of hydroxysafflor yellow A is provided according to the present invention. More particularly, a compound of hydroxysafflor yellow A sodium is provided, wherein safflower is utilized as a raw material, the compound is obtained by sufficient processes such as extraction, separation and purification. According to research results, the hydroxysafflor yellow A sodium is safer, more effective, more stable and more controllable than the hydroxysafflor yellow A as a monomer compound, which is applicable for treating blood circulation disorders such as coronary heart disease and angina pectoris. Accordingly, in order to accomplish the above object, the present invention provides a hydroxysafflor yellow A sodium, as shown in a formula (I). A molecular formula thereof is: C 27 H 31 O 16 Na. Another object of the present invention is to provide a method for preparing hydroxysafflor yellow A sodium as shown in the formula (I), comprising a step of preparing the hydroxysafflor yellow A sodium as shown in the formula (I) with hydroxysafflor yellow A as shown in a formula (II). Preferably, the hydroxysafflor yellow A sodium as shown in the formula (I) is prepared with the hydroxysafflor yellow A as shown in the formula (II) by a method comprising a step of: preparing the hydroxysafflor yellow A sodium as shown in the formula (I) with the hydroxysafflor yellow A as shown in the formula (II) by sodion-exchange resin column, or by reaction with a sodium salt; wherein the sodium salt is selected from the group consisting of sodium hydroxide, sodium carbonate and sodium bicarbonate. Preferably, the sodion-exchange resin is 001*7 sodion-exchange resin or macroporous HB-8 sodion-exchange resin. The above two kinds of resin products are commercially available, e.g., which are able to be purchased from Shanghai Huazhen Sci. & Tech. Co., Ltd. According to a preferred embodiment, safflower is utilized as a raw material, the hydroxysafflor yellow A sodium as shown in the formula (I) is obtained after extraction, sodium salt transformation, separation and purification, wherein the method particularly comprises steps of: a) extracting: extracting the safflower with water; b) transforming to sodium salt: passing extract obtained in the step a) through a sodion-exchange resin column, transforming safflor yellow to the hydroxysafflor yellow A sodium as shown in the formula (I); c) separating: separating eluant obtained in the step b), which comprises the hydroxysafflor yellow A sodium as shown in the formula (I), by a macroporous adsorbent resin column, obtaining a crude product of the hydroxysafflor yellow A sodium as shown in the formula (I); and d) purifying: separating the crude product obtained in the step c) of the hydroxysafflor yellow A sodium as shown in the formula (I) by dextran gel column chromatography, then filtering with an ultrafiltration membrane, obtaining a refined product of the hydroxysafflor yellow A sodium as shown in the formula (I). Preferably, in the step a), the safflower is extracted 2˜3 times with the water at 50˜100° C., wherein a weight of the water is 10˜30 times of a weight of the safflower. The safflower is extracted for 0.5˜24 h each time, then the extract is collected and cooled. Preferably, in the step b), the extract obtained in the step a) passes through the sodion-exchange resin column, wherein the sodion-exchange resin is 001*7 sodion-exchange resin or macroporous HB-8 sodion-exchange resin; then the eluant comprising the hydroxysafflor yellow A sodium as shown in the formula (I) is collected; Preferably, in the step c), the eluant obtained in the step b), which comprises the hydroxysafflor yellow A sodium as shown in the formula (I), is separated by a macroporous adsorbent resin HZ801 column, and water is utilized as an eluting agent, the eluant is collected for obtaining the crude product of the hydroxysafflor yellow A sodium as shown in the formula (I). Preferably, in the step d), the crude product obtained in the step c) of the hydroxysafflor yellow A sodium as shown in the formula (I) is separated by Sephadex LH-20 dextran gel column chromatography, and pure water is utilized as an eluting agent. The eluant comprising the hydroxysafflor yellow A sodium as shown in the formula (I) is collected and processed with vacuum concentration for obtaining concentrate thereof, then the concentrate is ultrafiltered by an ultrafiltration membrane with molecular weight cut-off of 8000˜10000 daltons for obtaining ultrafiltrate, the refined product of the hydroxysafflor yellow A sodium as shown in the formula (I) is obtained after freeze-drying. According to another embodiment, safflower is utilized as a raw material, the hydroxysafflor yellow A sodium is obtained after extraction, separation, purification, acidization and sodium salt transformation, wherein the method particularly comprises steps of: a) extracting: extracting the safflower with water for obtaining extract thereof; b) separating: separating the eluant of the safflower obtained in the step a) by a macroporous adsorbent resin column, obtaining a crude product of the safflor yellow; c) purifying: separating the crude product of the safflor yellow obtained in the step b) by dextran gel column chromatography, then filtering with an ultrafiltration membrane, freeze-drying for obtaining a refined product of the safflor yellow; d) acidizing: adding water to the refined product of the safflor yellow, adding acid (preferably hydrochloric acid) for adjusting a pH value to 1.5˜2.5, collecting pale yellow solid separated out for obtaining hydroxysafflor yellow A as shown in the formula (II); and e) transforming to sodium salt: adding water to the hydroxysafflor yellow A obtained in the step d), which is shown in the formula (II), and adjusting the pH value to 6 with 0.1 mol/L˜10 mol/L sodium hydroxide, sodium carbonate or sodium bicarbonate (preferably sodium hydroxide), transforming the hydroxysafflor yellow A as shown in the formula (II) to the hydroxysafflor yellow A sodium as shown in the formula (I), filtering with an ultrafiltration membrane, and freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium as shown in the formula (I). Preferably, the macroporous adsorbent resin column is HSZ801 macroporous adsorbent resin. Preferably, the dextran gel column chromatography comprises Sephadex LH-20 dextran gel column chromatography for separating, and pure water as an eluting agent; an ultrafiltration membrane with molecular weight cut-off of 8000˜10000 daltons for ultrafiltering. The water extract of the safflower mainly comprises the safflor yellow. The present invention surprisingly found that when the water extract of the safflower passes through the sodion-exchange resin column (such as the 001*7 sodion-exchange resin and macroporous HB-8 sodion-exchange resin), all the safflor yellow in the water extract of the safflower will be transformed to the compound of the hydroxysafflor yellow A sodium as shown in the formula (I). According to speculation of the inventor, during the separation processed by the sodion-exchange resin, free anionic of the hydroxysafflor yellow A as shown in the formula (II) of the safflor yellow is combined with sodion exchanged out, and forms the hydroxysafflor yellow A sodium as shown in the formula (I). The speculation is experimentally verificated as follows. A sample comprising the hydroxysafflor yellow A sodium as shown in the formula (I) is separated with the 001*7 sodion-exchange resin according to the method in the preferred embodiment 1 of the present invention, and eluant is collected, wherein a testing result shows that the hydroxysafflor yellow A sodium as shown in the formula (I) exists. Similarly, the present invention also found that, the hydroxysafflor yellow A can be prepared by: acidizing the refined product of the safflor yellow, then reacting with sodium salt such as sodium hydroxide, sodium carbonate and sodium bicarbonate. With the above method, the compound of the hydroxysafflor yellow A sodium as shown in the formula (I) is also able to be prepared with a high yield and a high purity. Another object of the present invention is to provide a pharmaceutic preparation, comprising hydroxysafflor yellow A sodium as shown in the formula (I) as an active ingredient and a pharmaceutically acceptable carrier; preferably, the pharmaceutic preparation is a freeze-dried injection; the freeze-dried injection is prepared by dissolving the hydroxysafflor yellow A sodium as shown in the formula (I), or a refined product of the hydroxysafflor yellow A sodium as shown in the formula (I) prepared by the above methods, in injection water, then packing in bottles after filtered by a 0.22 μm macroporous filtering membrane or an ultrafiltration membrane with molecular weight cut-off of 8000˜10000 daltons, and freeze-drying for obtaining the freeze-dried injection of the hydroxysafflor yellow A sodium as shown in the formula (I). A content of the hydroxysafflor yellow A sodium is 50˜200 mg per unit dosage. For example, the hydroxysafflor yellow A sodium is able to be prepared as: a) a freeze-dried injection of the hydroxysafflor yellow A sodium for injection use, and a content of the hydroxysafflor yellow A sodium is 50˜200 mg per bottle; b) a sodium chloride injection of the hydroxysafflor yellow A sodium, and a content of the hydroxysafflor yellow A sodium is 50˜200 mg per 100 ml sodium chloride; and c) a glucose injection of the hydroxysafflor yellow A sodium, and a content of the hydroxysafflor yellow A sodium is 50˜200 mg per 100 ml glucose injection. According to another preferred embodiment of the present invention, hydroxysafflor yellow A sodium as shown in the formula (I) and a freeze-dried injection thereof are provided, which are prepared by extracting the safflower, transforming by sodion-exchange resin, separating by macroporous resin, separating by dextran gel chromatography and ultrafiltering, wherein the preparation method particularly comprises steps of: a) utilizing the safflower as a raw material, adding water with a temperature of 50˜100° C. for extraction, wherein the safflower is extracted 2˜3 times and 0.5˜24 h each time, a weight of the water is 10˜30 times of a weight of the safflower; filtering out dregs after extraction, cooling to 5˜30° C., and waiting for 2˜24 h; b) passing the extract through the sodion-exchange resin, wherein a flow rate is 1˜30 ml/min; then discharging the extract from a column with water, wherein a volume of the water equals to a volume of the column; c) separating by macroporous adsorbent resin: separating the safflower extract obtained in the step b) by a macroporous adsorbent resin HZ801 column, wherein a ratio of an internal diameter and a height thereof is 1:8˜15; utilizing pure water as an eluting agent, wherein an eluting speed is 10˜30 ml/min; collecting eluant thereof, processing with vacuum concentration for obtaining a crude concentrate of the hydroxysafflor yellow A sodium; d) separating with the dextran gel chromatography: separating the crude concentrate of the hydroxysafflor yellow A sodium obtained in the step c) by Sephadex LH-20 dextran gel chromatography after filtration or centrifugation, wherein a ratio of a diameter and a height of a chromatography column is 1:5˜20; utilizing the pure water as the eluting agent, wherein the eluting speed is 1˜10 ml/min; collecting eluant of the hydroxysafflor yellow A sodium, processing with vacuum concentration for obtaining concentrate thereof; e) ultrafiltering: ultrafiltering the concentration obtained in the step d) by an ultrafiltration membrane with molecular weight cut-off of 8000˜10000 daltons after filtration or centrifugation, and obtaining ultrafiltrate; f) freeze-drying: freeze-drying the ultrafiltrate obtained in the step e) for obtaining the hydroxysafflor yellow A sodium; and g) dissolving the refined product of the hydroxysafflor yellow A sodium obtained in the step f) in injection water, then packing in bottles after filtered by a 0.22 μm macroporous filtering membrane or the ultrafiltration membrane with the molecular weight cut-off of 8000˜10000 daltons, and freeze-drying for obtaining the freeze-dried injection of the hydroxysafflor yellow A sodium; wherein the sodion-exchange resin is 001*7 sodion-exchange resin or macroporous HB-8 sodion-exchange resin; the macroporous resin separation utilizes macroporous adsorbent resin HZ801; the dextran gel column chromatography separation utilizes dextran gel column chromatography LH-20; the ultrafiltration utilizes the ultrafiltration membrane with the molecular weight cut-off of 8000˜10000 daltons. The present invention also provides application of the hydroxysafflor yellow A sodium, as shown in the formula (I), in medicine preparation, wherein the medicine has an effect of preventing platelet aggregation induced by PAF or ADP, so as to prevent and treat a disease caused by myocardial ischemia, cerebral ischemia or thrombosis. A clinical dosage thereof is 50˜200 mg per day. According to the present invention, the safflower is utilized as the raw material. The monomer pharmaceutical compound, the hydroxysafflor yellow A sodium as shown in the formula (I), is obtained by sufficient processes, and a purity thereof is surely above 98.5%. According to the present invention, the hydroxysafflor yellow A sodium is more stable and more conducive to safety and controllability of the medicine. Therefore, the hydroxysafflor yellow A sodium is a monomer compound, which is safer, more effective, more stable and more controllable than the hydroxysafflor yellow A, for treating blood circulation disorders such as coronary heart disease and angina pectoris. Pharmacodynamics Experiment 1: Object: observing effects of preventing acute myocardial infarction provided by the hydroxysafflor yellow A sodium and safflor yellow injection (50 mg/bottle) which is intravenously injected on dogs. Medicine Tested: safflor yellow injection (50 mg/bottle); purchased from: Zhejiang Yongning Pharma Co., Ltd; content: 42.5 mg the hydroxysafflor yellow A per 50 mg/bottle; and freeze-dried powder of the hydroxysafflor yellow A sodium (prepared in the preferred embodiment 1). Animal: 18 healthy mongrels, half male and half female, randomly divided into three groups. Group Quantity Dosage Injection method Saline 6 1 ml/kg Intravenous injection Safflor yellow 6 10 mg/kg Intravenous injection injection Hydroxysafflor 6 10 mg/kg Intravenous injection yellow A sodium The above medicines were all intravenously injected, which was in accordance with a clinical application method (intravenous injection), wherein the intravenous injection was provided once. Experiment Method Intravenously anaesthetizing the animal with 3% pentobarbital sodium after weighing, wherein a dosage was 30 mg/kg; processing with trachea cannula, then connecting to an anesthesia ventilator and processing with thoracotomy for mechanical ventilation, wherein a respiratory frequency was 16˜18 times/min, a ratio of inspiratory and expiratory volume was 1:2, tidal volume was 350˜550 ml, and ventilation indexes were adjusted according to results of blood gas analysis; subcutaneously inserting needle electrodes into four limbs and chest, monitoring standard limb leads and V1, V3 and V5 electrocardiograms; processing with thoracotomy along a third intercostals space of left sternal border, and cutting off a fourth rib for fully exposing a heart; cutting open pericardium and processing with pericardium hammock; intravenously injecting lidocaine with a dosage of 2 mg/kg for preventing arrhythmia; separating a left anterior descending initial portion of coronary artery, providing a first loose knot and a second loose knot by twining two sections of No. 1 silk at an anterior descending artery, inserting a steel wire with a diameter of 1 mm into the first loose knot, ligating the first knot, wherein the steel wire was ligated with the coronary artery, then drawing out the steel wire; ingating the senond knot after 30 minutes (intravenously injecting the medicine to be tested at the same time); observing changes of the electrocardiograph 5 min, 10 min, 30 min, 1 h, 2 h, 3 h and 4 h after ligating the second knot; taking the heart out after 4 h and weighting the whole heart, pressing 10 ml 10% carbon ink along openings of left and right coronary arteries at aortic root for displaying non-ischemic myocardium (dyed black) and ischemic myocardium (not dyed black), cutting the ischemic myocardium for weighting; then cutting the ischemic myocardium into 0.5˜1 cm thick myocardium sheets and washing with the saline, dyeing in 0.025% nitro blue tetrazolium (NBT) at 37° C.; shaking the NBT during dyeing for fully contacting with the myocardium; washing unnecessary NBT right after 30 min; wherein infarcted myocardium was not dyed, non-infarcted myocardium was dyed black, cutting off the dyed part and weighing the non-dyed part. Observation Index Main observation indexes after injection are ST segment elevation of precordial electrocardiograph, myocardial infarction range, etc., which are as follows. a) ST segment elevation: ΔST, wherein the ST before ligation is a 0 point; observation time is 5 min, 10 min, 30 min, 1 h, 2 h, 3 h and 4 h after injection. b) myocardial infarction degree the weight of ischemic myocardium (g): a weight of blood-supplying myocardium of the ligated coronary artery; the weight of infarcted myocardium (g): a weight of non-dyed myocardium; myocardial infarction rate (%): (the weight of ischemic myocardium/the weight of infarcted myocardium)*100%. Comparison A negative comparison group with the saline was provided, wherein a dosage was 1 mg/kg. Analysis Experimental results are shown in a form of X±S, and were processed with unpaired t-test statistics, wherein P<0.05 represents significant statistical difference. Experimental Results a) influence of the medicine on the ST segment elevation of the anesthetized dog after death caused by myocardial infarction. Compared to the saline group, the ST segment elevation caused by anesthetized dog, which was processed with thoracotomy and ligated at the coronary artery, was significantly decreased by the safflor yellow injection and hydroxysafflor yellow A sodium 5 min-4 h after injection. The results are shown in Table 1. TABLE 1 influence on ST segment elevation of anesthetized dog processed with thoracotomy after death caused by myocardial infarction Medicine n 5 min 15 min 30 min 1 h 2 h 3 h 4 h Saline 6 1.39 ± 1.55 ± 1.49 ± 1.55 ± 1.47 ± 1.32 ± 1.28 ± 0.22 0.41 0.32 0.41 0.41 0.23 0.22 Safflor yellow 6 0.87 ± 1.02 ± 0.88 ± 0.79 ± 0.87 ± 0.76 ± 0.79 ± 0.43 0.46* 0.42* 0.42** 0.30* 0.42* 0.34* Hydroxysafflor 6 0.84 ± 0.81 ± 0.78 ± 0.72 ± 0.61 ± 0.48 ± 0.33 ± yellow A sodium 0.34* 0.29* 0.56* 0.36* 0.51* 0.40* 0.42** b) the safflor yellow injection and the hydroxysafflor yellow A sodium were both able to significantly decrease the myocardial infarction range of the anesthetized dog processed with thoracotomy which was dead because of acute myocardial infarction, wherein a performance of the hydroxysafflor yellow A sodium was the best. The results are shown in Table 2. TABLE 2 influence on acute myocardial infarction range of dog Weight of Dangerous Infarcted Infarction Medicine n myocardium (g) area (g) area (g) rate % Saline 9   72 ± 18.1 12.0 ± 1.9 5.2 ± 1.6 42.5 ± 10.5  Safflor yellow 6 80.3 ± 11.3  17.5 ± 3.8** 4.1 ± 1.8 25.3 ± 12.3** Hydroxysafflor 6 73.2 ± 9.5  13.1 ± 3.8  2.2 ± 0.3** 18.1 ± 5.8*** yellow A sodium wherein *p<0.05, **p<0.01, ***p<0.001 vs the saline group. Conclusion Compared to the safflor yellow infection, the hydroxysafflor yellow A sodium had a better effect on preventing myocardial ischemic necrosis. Pharmacodynamics Experiment 2: Effects of hydroxysafflor yellow A sodium on presenting platelet aggregation and Acute cerebral ischemia. Medicine Tested: freeze-dried powder of the hydroxysafflor yellow A sodium (prepared in the preferred embodiment 1). Experiment Content a) selectivity of heart and cerebral vessels isolated from the dog: fixing a cerebral basilar artery and a coronary artery ring of a Beagle dog on an isolated vascular measurement device, adjusting tension sensor and adding lemon phenylephrine to a liquid bath cup for maintaining proper vessel tension, then adding the hydroxysafflor yellow A sodium injection to the liquid bath cup once every 5 min with a dosage of 10 mg/ml until a vascular ring showed very weak response or no response (generally, the medicine was feed 4˜5 times); calculating a vascular systolic or diastolic change value; wherein experimental results indicate that a relaxation effect of the hydroxysafflor yellow A sodium injection on a cardiac vascular ring was 30.9%, while a relaxation effect on a cerebral vascular ring was 72.8%; which means that the hydroxysafflor yellow A sodium injection has sufficient selectivity and relaxation function on the cerebral vascular. b) influence on acute cerebral ischemia: utilizing SD rats, providing a cerebral ischemia model by middle cerebral artery occlusion (MCAO) suture method after intravenous injection with hydroxysafflor yellow A sodium; judging neurological behavior after feeding for 24 h, then cutting a head and taking a brain out, putting into a mould and cutting into 7 pieces, dyeing with TTC in such a manner that survival cerebral tissues were dyed red, and necrotic cerebral tissues were not dyed; calculating a ratio of the necrotic cerebral tissue and a cerebral hemisphere by a graphic analysis software; wherein results indicated that a cerebral infarction area of a solvent control group was 38%, and a cerebral infarction area of a nimodipine positive control group was 15.4%; cerebral infarction areas of hydroxysafflor yellow A sodium injection low, medium and high dosage groups were respectively 38%, 27.2% and 21.5%; compared to the solvent control group, medium and high dosage groups had significant effects on reducing cerebral tissue necrosis caused by the acute cerebral ischemia. c) influence on cerebral vascular permeability of the rats: intravenously injecting the rat once a day for 7 consecutive days, anesthetizing the rat after the last injection, intravenously injecting Evans blue with a dosage of 50 mg/kg, ligating bilateral common carotid arteries after 5 minutes, cutting a head after 3 hours and taking a brain out, immersing in a formamide solution after weighing, putting in an incubator with a temperature of 45° C. for 72 h, in such a manner that the Evans blue in the cerebral vessel was leached to the formamide solution, detecting an amount of the Evans blue in the formamide solution by a spectrophotometer, wherein the amount indicated a level of the cerebral vascular permeability; wherein experimental results showed that the hydroxysafflor yellow A sodium injection medium and high dosage groups had significant effects on reducing the Evans blue leached from the cerebral vascular, which means the medicine has a sufficient effect on reducing the vascular permeability. d) influence on cerebral blood flow: utilizing Beagle dogs as experimental animals, anesthetizing with pentobarbital sodium before isolating an external jugular vein, an internal jugular vein and a vertebral artery, ligating the external jugular vein, placing a flow sensors in the internal jugular vein and the vertebral artery, adding the blood flows recorded by the two sensors together and multiplying by 2 for representing blood supply of a whole brain, taking the brain out after the experiment for weighing and calculating the blood flow per 100 g cerebral tissue; wherein experimental results showed that the hydroxysafflor yellow A sodium injection has an effect of increasing the blood flow on the medium and high dosage groups after intravenous injection, but a maintaining time thereof was short (about 15 min); the experiment suggested that intravenous injection should be apply for clinically treating acute cerebral ischemia. e) influence on acute cerebral hypoxia: utilizing Kunming mice and the SD rats for the experiment, putting the animals in a hypoxic environment, recording a survival time, observing whether a tolerance of the acute hypoxia of the animal was increased after feeding the medicine; wherein experimental results showed that for the mice in a sealed container, the survival time of the solvent control group was 32 min and the survival times of the hydroxysafflor yellow injection low, medium and high dosage groups were 37 min, 37 min and 37 min; statistical results indicated a significant difference (P<0.05˜0.01) according to the solvent control group; the rat experiment was provided in an environment with 97% nitrogen and 3% oxygen; time counting started when the animal was put into the container and stoped when the animal was out of breath, an average survival time of the solvent control group was 3 minutes and 43 seconds and a survival time of the positive control group (nimodipine) was 5 minutes and 45 seconds, a difference therebetween was significant; survival times of the hydroxysafflor yellow A sodium injection low, medium and high dosage groups were 3 minutes and 30 seconds, 4 minutes and 35 seconds, and 4 minutes and 12 seconds; and a significant survival time difference existed between the solvent control group and the medium and high dosage groups. f) preventing platelet accumulation: the experiment comprises instrument detection and in vivo detection: 1) the instrument detection method: intravenously injecting hydroxysafflor yellow A sodium in a rabbit once a day for 5 consecutive days, collecting 4 ml heart blood within 2 h after the last injection, centrifuging with a low speed for obtaining a platelet-rich blood serum; centrifuging with a high speed for obtaining a platelet-poor blood serum, utilizing adenosine diphosphate (ADP) and platelet activating factor (PAF) as platelet accumulation derivant, and testing with a platelet aggregation analyzer; wherein the platelet aggregation experiment of hydroxysafflor yellow A sodium injection on preventing the platelet aggregation induced by the ADP and the PAF indicated a sufficient effect on presenting the platelet aggregation, and a positive quantity-effect relationship existed between the three dosage groups; and 2) the in vivo detection method: forming a short circuit between a artery and a vein of the rat with a latex tube, fixing a operation silk in the latex tube; with platelet adhesion, opening the short circuit in such manner that the blood flows cross the artery and the vein through the latex tube for 15 minutes, then taking the silk out for weighing, subtracting a dry weight of the silk for obtaining a weight of the platelet; wherein the experimental results showed that the weight of the platelet adhered of the solvent control group was 14.8±1.57 mg, the weight of the positive control group was 8.62±2.79 mg, and the weights of the hydroxysafflor yellow A sodium low, medium and high dosage groups were 13.8±1.95 mg, 9.87±1.50 mg and 9.02±1.29 mg; a significant difference existed according to the medium, high dosage groups and the solvent control group, which indicated a sufficient effect of the hydroxysafflor yellow A sodium injection on preventing platelet aggregation of the rat. g) influence on blood viscosity: processing a rabbit with intravenous injection once a day for 5 consecutive days, directly detecting heart blood processed with anticoagulant by a blood rheometer 2 hour after the last injection; wherein results showed that, compared to the solvent control group, low-cut, medium-cut and high-cut, which were indexes of the blood viscosity, were decreased with increase of the dosage of the hydroxysafflor yellow A sodium groups; the effect of the high dosage group was better than the positive control nimodipine injection group, which indicated that the hydroxysafflor yellow A sodium injection has a sufficient effect on decreasing blood viscosity. Stability Experiment Object: observing stability of the hydroxysafflor yellow A sodium as shown in the formula (I) and the hydroxysafflor yellow A, and physical and chemical data thereof. Medicine Tested: The hydroxysafflor yellow A prepared according to the Chinese patent CN102675379A, wherein a purity thereof was 89.9%. The hydroxysafflor yellow A sodium (prepared in the preferred embodiment 1) with a purity of 98.6%. Experimental results are shown in Table 3. TABLE 3 experimental result of stability of hydroxysafflor yellow A sodium Acceler- Acceler- Acceler- Acceler- ated for ated for ated for ated for Event 0 month 1 month 2 months 3 months Hydroxy- Total 10.1% 14.9% 20.8% 28.6% safflor impurity yellow A Content 89.8% 84.7% 79.2% 71.2% (counting Hydroxyl A) Hydroxy- Total  1.4%  1.9%  2.4%  3.0% safflor impurity yellow A Content 94.9% 94.4% 94.1% 93.5% sodium (counting Hydroxyl A) The hydroxysafflor yellow A prepared in the preferred embodiment 2 with acidizing, wherein a purity thereof was 99.2%. The hydroxysafflor yellow A sodium (prepared in the preferred embodiment 1) with a purity of 99.2%. Experimental results are shown in Table 4. TABLE 4 experimental result of stability of hydroxysafflor yellow A sodium Acceler- Acceler- Acceler- Acceler- ated for ated for ated for ated for Event 0 month 1 month 2 months 3 months Hydroxy- Total  0.8%  5.9% 10.7% 18.6% safflor impurity yellow A Content 99.1% 94.1% 89.2% 81.3% (counting Hydroxyl A) Hydroxy- Total  0.8%  1.3%  1.9%  2.5% safflor impurity yellow A Content 95.6% 95.1% 94.5% 94.0% sodium (counting Hydroxyl A) The physical and chemical data of the hydroxysafflor yellow A sodium are shown in Table 5. TABLE 5 physical and chemical data of hydroxysafflor yellow A sodium Simple PH Solubility Hydroxysafflor yellow A 1.9 Slightly soluble Hydroxysafflor yellow A sodium 5.8 Easily soluble According to the experimental results, the comparison experiment of the hydroxysafflor yellow A sodium as shown in the formula (I) and the hydroxysafflor yellow A illustrates that the stability of the hydroxysafflor yellow A sodium was better, in such a manner that quality and safety thereof were better. Acidity of the hydroxysafflor yellow A was strong and was out of pH tolerance of human, which will lead to discomfort such as pain. Furthermore, solubility thereof was not sufficient. According to the present invention, the hydroxysafflor yellow A sodium has better tolerance and solubility. A structure of the hydroxysafflor yellow A sodium compound prepared in the preferred embodiment 1 was identified by infrared spectrometry (IR), mass spectrometry (MS), hydrogen nuclear magnetic resonance spectrometry ( 1 H-NMR), carbon nuclear magnetic resonance spectrometry ( 13 C-NMR), COSY spectrometry, DEPT135 spectrometry and HSQC spectrometry, wherein the structure is shown as follows. a) infrared absorption spectrum Instruments: Bruker VECTOR-22 infrared absorption spectrograph; and IR (compressed potassium bromide); wherein main characteristic peaks of the IR spectrum are shown in Table 6. TABLE 6 characteristic peaks of IR spectrum Absorption peak cm −1 Vibration type Group Strength 3361 ν —OH —OH br s 1650 ν C═O —C═O s 1624 ν C═C —C═C— s 1604 1515 ν C═C C 6 H 6 s 1440 δ —CH2 —CH 2 m 1171 1077 1005 ν C—O —C—OH s b) mass spectrum Instrument: LC-MS multistage ion trap mass spectrometry system (LCQ-DECAXP) of America FINNIGAN company. Test condition: ESI The mass spectrum: +c ESI 635.14 (M) + −c ESI 611.25 (M-Na) − c) hydrogen nuclear magnetic resonance spectrum and carbon spectrum Instrument: BRUCKER AVANCE III 500 superconducting NMR spectrometer. Test condition: solution: DMSO, interior label: TMS. The nuclear magnetic resonance 1 H-NMR ( FIG. 1 ), 13 C-NMR ( FIG. 2 ), COSY spectrum ( FIG. 3 ), DEPT135 spectrum ( FIG. 4 ) and HSQC spectrum ( FIG. 5 ) of the hydroxysafflor yellow A sodium as shown in the formula (I) are illustrated by drawings. 1 H-NMR data of the hydroxysafflor yellow A sodium as shown in the formula (I) are as follows. According to chemical shifts δ (ppm), 2.84˜4.14 (14H) belong to a sugar moiety hydrogen G1˜G6 and G′1˜G′6; 4.39˜4.77 (8H) belong to sugar hydroxyl hydrogen; 7.26 (1H) and 7.39 (1H) belong to 8 and 9; 6.75˜7.42 (4H) belong to 11˜15; 18.65 (1H) belongs to 3-OH; 4.70 (1H) belongs to 4-OH; and 9.72 (1H) belongs to 13-OH. 13 C-NMR data of the hydroxysafflor yellow A sodium as shown in the formula (I) are as follows. According to chemical shifts δ (ppm) of the DEPT135, 61.05 (1C) and 61.46 (1C) (secondary carbon) belong to sugar moiety carbon G6 and G′6; 68.60, 69.62, 69.83, 70.86, 73.80, 78.25, 79.15, 80.19, 80.62, and 85.57 (10C) (tertiary carbon) belong to the sugar moiety carbon G1˜G5 and G′1˜G′5; 115.52 (2C) (tertiary carbon) belongs to 12 and 14; 129.26 (2C) (tertiary carbon) belongs to 11 and 15; 123.22 (1C) and 135.63 (1C) (tertiary carbon) belong to 8 and 9; the chemical shift (PPM) 189.37, 105.96, 195.29, 85.24, 182.69 and 99.24 (6C) belong to 1˜6; 179.06 (1C), 127.27 (1C) and 158.34 (1C) respectively belong to 7, 10 and 13. These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a hydrogen spectrum of hydroxysafflor yellow A sodium as shown in the formula (I) according to the present invention. FIG. 2 is a carbon spectrum of the hydroxysafflor yellow A sodium as shown in the formula (I) according to the present invention. FIG. 3 is a COSY spectrum of the hydroxysafflor yellow A sodium as shown in the formula (I) according to the present invention. FIG. 4 is a DEPT135 spectrum of the hydroxysafflor yellow A sodium as shown in the formula (I) according to the present invention. FIG. 5 is an HSQC spectrum of the hydroxysafflor yellow A sodium as shown in the formula (I) according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Preferred Embodiment 1 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding the above centrifugate to balanced 001*7 sodion-exchange resin, wherein a ratio of a diameter and a height of a resin column was 1:10, a volume thereof was 500 ml, a flow rate thereof was 3 ml/min; then discharging extract from the column with water, wherein a volume of the water equals to the volume of the column; collecting liquid flowed out which comprises the hydroxysafflor yellow A sodium, slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of the hydroxysafflor yellow A sodium; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the hydroxysafflor yellow A sodium through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the hydroxysafflor yellow A sodium; processing the collected liquid with vacuum concentration at 60° C. for obtaining a concentrated refined product of the hydroxysafflor yellow A sodium, wherein judging from the safflower, 1 kg the safflower was able to prepare 35˜50 ml concentrate; freeze-drying for obtaining a refined powder of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 98.6%, a yield thereof was 0.45% judging from the safflower. Dissolving the hydroxysafflor yellow A sodium prepared above in injection water, packing in bottles after filtered by a 0.22 μm macroporous filtering membrane, then freeze-drying for obtaining a freeze-dried injection of the hydroxysafflor yellow A sodium. Preferred Embodiment 2 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of safflor yellow; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the safflor yellow through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the safflor yellow; processing the collected liquid with vacuum concentration at 60° C. for obtaining safflor yellow concentrate, wherein judging from the safflower, 1 kg the safflower was able to prepare 35˜50 ml concentrate; freeze-drying for obtaining a powder of the safflor yellow which was pale yellow, wherein a purity thereof was 90%; adding water to the safflor yellow powder before acidizing with HCl, placing at a cool place for 2˜24 h until solid was separated out; filtering the solid before adding water, then adjusting the pH value to 6.0 with 0.1 mol/L˜10 mol/L sodium hydroxide, freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 99.2%, a yield thereof was 0.70% judging from the safflower. According to identification, a structure of the hydroxysafflor yellow A sodium was as shown in the formula (I). Dissolving the refined product of the hydroxysafflor yellow A sodium prepared above in injection water, packing in bottles after filtered by an ultrafiltration membrane with molecular weight cut-off of 8000˜10000 daltons, then freeze-drying for obtaining a freeze-dried injection of the hydroxysafflor yellow A sodium. Preferred Embodiment 3 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding the above centrifugate to balanced 001*7 sodion-exchange resin, wherein a ratio of a diameter and a height of a resin column was 1:10, a volume thereof was 500 ml, a flow rate thereof was 3 ml/min; slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of hydroxysafflor yellow A sodium; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the hydroxysafflor yellow A sodium through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the hydroxysafflor yellow A sodium; processing the collected liquid with vacuum concentration at 60° C. for obtaining a concentrated refined product of the hydroxysafflor yellow A sodium, wherein judging from the safflower, 1 kg the safflower was able to prepare 35˜50 ml concentrate; freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 98.7%, a yield thereof was 0.50% judging from the safflower. According to identification, a structure of the hydroxysafflor yellow A sodium was as shown in the formula (I). Preferred Embodiment 4 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of safflor yellow; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the safflor yellow through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the safflor yellow; processing the collected liquid with vacuum concentration at 60° C. for obtaining safflor yellow concentrate, wherein judging from the safflower, 1 kg the safflower was able to prepare 35˜50 ml concentrate; freeze-drying for obtaining a powder of the safflor yellow which was pale yellow, wherein a purity thereof was 90%; adding water to the safflor yellow powder before acidizing with HCl, placing at a cool place for 2˜24 h until solid was separated out; filtering the solid before adding water, then adjusting the pH value to 6.0 with 0.1 mol/L˜10 mol/L sodium hydroxide, freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 99.1%, a yield thereof was 0.75% judging from the safflower. According to identification, a structure of the hydroxysafflor yellow A sodium was as shown in the formula (I). Preferred Embodiment 5 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of safflor yellow; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the safflor yellow through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the safflor yellow; processing the collected liquid with vacuum concentration at 60° C. for obtaining safflor yellow concentrate, wherein judging from the safflower, 1 kg the safflower was able to prepare 35˜50 ml concentrate; freeze-drying for obtaining a powder of the safflor yellow which was pale yellow, wherein a purity thereof was 90%; adding water to the safflor yellow powder before acidizing with HCl, placing at a cool place for 2˜24 h until solid was separated out; filtering the solid before adding water, then adjusting the pH value to 6.0 with 0.1 mol/L˜10 mol/L sodium hydroxide, freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 99.3%, a yield thereof was 0.69% judging from the safflower. According to identification, a structure of the hydroxysafflor yellow A sodium was as shown in the formula (I). Preferred Embodiment 6 Hydroxysafflor Yellow A Sodium Weighting safflower, adding deionized water, wherein a weight of the deionized water was 12.5 times of a weight of the safflower, extracting at 100° C. for 20˜25 min, then filtering, adding the deionized water into residue and extracting again with the above condition, wherein a weight of the deionized water was 10 times of the weight of the safflower, then filtering; mixing filtrate, cooling to a room temperature, processing with centrifugation by a centrifugal machine, collecting centrifugate for further utilization; slowly adding to a macroporous adsorption resin (HZ801) separation column, wherein a ratio of a diameter and a height thereof was 1:12, a sampling flow rate was 10 ml/min; eluting with the deionized water at the room temperature after sampling, wherein a eluting flow rate was 20 ml/min; processing eluant with vacuum concentration at 60° C. for obtaining a concentrated crude product of safflor yellow; wherein judging from the safflower, 1 kg the safflower was able to prepare 100 ml concentrate; passing the concentrated crude product of the safflor yellow through a dextran gel LH-20 column, wherein a ratio of a diameter and a height thereof was 1:5, a sampling volume was 10% of a volume of a column holder, pure water was utilized as an eluting agent, an eluting flow rate was 5 ml/min; collecting liquid comprising the safflor yellow; adding the collected liquid to balanced strongly acidic H cationic-exchange resin and collecting liquid flowed out; processing the collected liquid with vacuum concentration at 60° C. for obtaining hydroxysafflor yellow A concentrate, placing at a cool place for 2˜24 h until solid was separated out; filtering the solid before adding water, then adjusting the pH value to 6.0 with 0.1 mol/L˜10 mol/L sodium hydroxide, freeze-drying filtrate for obtaining a refined product of the hydroxysafflor yellow A sodium which was pale yellow, wherein a purity thereof was 99.8%, a yield thereof was 0.68% judging from the safflower. According to identification, a structure of the hydroxysafflor yellow A sodium was as shown in the formula (I). One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

A hydroxysafflor yellow A sodium compound as shown in a formula (I) and preparation as well as medicinal application thereof are provided. According to the present invention, the safflower is utilized as a raw material. A monomer pharmaceutical compound, the hydroxysafflor yellow A sodium, is obtained by sufficient processes, and a purity thereof is surely above 98.5%. Therefore, the hydroxysafflor yellow A sodium is a monomer compound, which is safer, more effective, more stable and more controllable than hydroxysafflor yellow A, for treating blood circulation disorders such as platelet aggregation, coronary heart disease, angina pectoris and acute cerebral ischemia. Furthermore, the hydroxysafflor yellow A sodium has sufficient solubility and human tolerance.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority benefit under 35 U.S.C. Section 119(e) to U.S. Provisional Patent Ser. No. 61/334,653 filed on May 15, 2010 the entire disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION The present invention relates generally to methods for geological modeling. More particularly, but not by way of limitation, embodiments of the present invention include methods for downscaling geological property models. BACKGROUND OF THE INVENTION Geological models, such as petroleum reservoir geological models, are often utilized by computer systems for simulation. For example, computer systems may utilize petroleum reservoir geologic models to simulate the flow and location of hydrocarbons within a reservoir. Geological models are typically formed utilizing thousands or millions of geologic cells, with each cell corresponding to a location and a physical geologic or petrophysical property. The number of cells or cell size in a model is generally determined by the computing capabilities of geomodeling packages or flow simulator and the level of heterogeneity geomodelers want to capture. Accurate reservoir performance forecasting requires three-dimensional representation of the geological model. The geological model is commonly built with the use of well and seismic data and stochastic simulation techniques. Simulated rock property values are filled in the three-dimensional cells constructed at a given scale. Cell dimensions are changed according to the needs of flow simulation. The cells can be “upscaled” into larger (“coarser”) cells, “downscaled” into smaller (“finer”) cells or a combination thereof. Conventional downscaling methods typically resample the property values from coarse grids to fine grids, which gives the same property value of all fine-grid cells located in the same coarse grid. Sharp changes can be commonly created across the coarse grid boundaries. For example, when a coarse grid model with four cells is downscaled into a sixteen cell unit, the downscaled model still keeps the same values as the coarse model. The simple conventional approach can certainly maintain the data value consistency between the initial model and the downscaled model; however, the conventional downscaled model falls short in numerous regards, including: inability to capture the fine-scale heterogeneities, inability to preserve the continuity across the coarse grid areas, inability to quantify static property uncertainty and inability to condition to available fine-scale hard data. Kriging with local varying mean (LVM) provides a channel for adding coarse-scale data into the kriging system hence into spatial estimators. This type technique is, for example, described in the following document: Goovaerts, P., 1997 , “Geostatistics for Natural Resources Evaluation ”, Oxford University Press, New York, p. 496. However, the coarse information is used only as an expected value replacing the local simple kriging (SK) stationary mean. Kriging with LVM can not reproduce the local mean, and hence cannot reproduce the coarse data value exactly. The goal of block kriging is to estimate block values through weighted linear combinations of conditioning point data with the weights obtained by solving a block kriging system. Block kriging is similar to an upscaling process, as opposed to the inverse process of downscaling. This technique is, for example, described in the following documents: Journel, A. and Huijbregts, C. J.: 1978, Mining Geostatistics, Academic Press, New York. Isaaks, E. and Srivastava, R.: 1989, An introduction to applied geostatistics, Oxford University Press, New York. A block sequential simulation (bssim) algorithm is currently utilized for integrating coarse-scale block average data of any shape (e.g., remove sensing or seismic travel-time tomographic data) with fine data. This technique is, for example, described in the following documents: Liu, Y., 2007 , “Geostatistical integration of linear coarse - scale data and fine - scale data ”, PHD dissertation, Stanford University, California, p. 211. Liu, Y. and Journel, A. G., 2009 , “A package for geostatistical integration of coarse and fine scale data ”, Computers & Geosciences, 35(3), 527-547. Unfortunately, available computing power and time constraints limit the number of cells that may be practically utilized by geologic models. Thus, bssim is limited to downscaling small models that have less than 1000 coarse grid cells due to its excessive memory costs. Therefore, a need exists for a practical downscaling algorithm for geological modeling to capture the fine-scale heterogeneities, to preserve the continuity across the coarse grid areas, to quantify static property uncertainty, and to condition to available coarse and fine-scale hard data, all while using the least amount of memory. SUMMARY OF THE INVENTION In an embodiment of the present invention, a computer-aided method of downscaling a three-dimensional geological model by generating numerical stochastic fine-scale models conditioning to data of different scales and capturing spatial uncertainties which involves a downscaling algorithm, the method includes: (a) generating a point covariance map, wherein the point covariance map is generated by obtaining point covariance values between a first base point and all points within an expanded area; (b) storing the point covariance map, wherein the point covariance map is stored based on covariance symmetry, wherein about half of the point covariance map is stored; (c) generating a block-to-point covariance map, wherein the block-to-point covariance map is generated by obtaining block-to-point covariance values between a first base block and all points within the expanded area; (d) storing the block-to-point covariance map, wherein the block-to-point covariance map is stored based on covariance symmetry, wherein about half of the block-to-point covariance map is stored; (e) calculating block-to-block covariance values, wherein the block-to-block covariance values are generated by obtaining the block-to-block covariance values between a first base block and a second block, wherein the block-to-block covariance values are obtained from the stored block-to-point covariance map, wherein the block-to-block covariance values are calculated by averaging the block-to-point covariance values covered by a second block; (f) storing the block-to-block covariance values; (g) randomly selecting a first simulation node within the defined simulation area; (h) utilizing the stored point and block-to-point covariance maps to search and retrieve neighboring point covariance values and neighboring block-to-point covariance values around the simulation node; (i) constructing a kriging system, wherein the constructed kriging system is based on the retrieved point and block-to-point covariance values and the calculated block-to-block covariance; (j) solving the kriging system; (k) computing the kriging mean and the kriging variance; (l) defining a sampling interval based on the calculated local kriging mean and variance; (m) simulating a value by randomly drawing a value from the kriging mean and variance defined interval in a global target cumulative distribution; (n) assigning the simulation value to a simulation location; and (o) repeating steps (h) through (n) until all nodes within the defined area have been simulated. In another embodiment of the present invention, a computer-aided method of downscaling a three-dimensional geological model by generating numerical stochastic fine-scale models conditioning to data of different scales and capturing spatial uncertainties which involves a downscaling algorithm, the method includes: (a) generating a point covariance map; (b) storing the point covariance map; (c) generating a block-to-point covariance map; (d) storing the block-to-point covariance map; (e) calculating block-to-block covariance values; (f) storing the block-to-block covariance values; (g) randomly selecting a first simulation node within the defined simulation area; (h) utilizing the stored point and block-to-point covariance maps to search and retrieve neighboring point covariance values and neighboring block-to-point covariance values around the simulation node; (i) constructing a kriging system; (j) solving the kriging system; (k) computing the kriging mean and the kriging variance; (l) defining a sampling interval based on the calculated local kriging mean and variance; (m) simulating a value by randomly drawing a value from the kriging mean and variance defined interval in a global target cumulative distribution; (n) assigning the simulation value to a simulation location; and (o) repeating steps (h) through (n) until all nodes within defined area have been simulated. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: FIG. 1 is a schematic of data in a defined search area and the corresponding kriging system in accordance with an embodiment of the present invention. FIG. 2 is a simulation workflow in accordance with an embodiment of the present invention. FIG. 3 is a point covariance map in accordance with the present invention. FIG. 4 is a block covariance map in accordance with the present invention. FIG. 5 is a block-to-block covariance map in accordance with the present invention. FIG. 6 is a block-to-point covariance map in accordance with the present invention. FIG. 7 is a flow diagram in accordance with the present invention. FIG. 8 is a SAGD geomodel resealing workflow in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not as a limitation of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations that come within the scope of the appended claims and their equivalents. In petroleum and other earth science applications, one often needs to account for a large variety of data with different support volumes carrying information at different scales. The coarse scale data, such as seismic travel time, well-test effective permeability, or streamline data, are henceforth referred to as “block” data. The block data are average values, not necessarily linear, over their respective support volumes. The fine scale data, such as well data or core data, henceforth referred to as “point” data. Mapping or numerical modeling requires incorporation of all relevant information from the data with different scales. The present invention provides a downscale simulation algorithm (henceforth referred to as downsim), which can stochastically rescale the model from coarse scale to fine scale, while honoring the input coarse scale block data and fine scale point data. The block data B(ν) is defined as the spatial linear average of point values P(u) over the coarse scale data location (Journel and Huijbregts, 1978; Liu, 2007): B ⁡ ( v ) = 1  v  ⁢ ∫ v ⁢ P ⁡ ( u ) ⁢ ⅆ u ⁢ ⁢ ( u ∈ v ) ( 1 ) where ν denotes the block location and |ν| denotes the block volume. In the discrete form, assuming equal weights for all fine cells, it can be written as: B j = 1 n j ⁢ ∑ i = 1 n j ⁢ P ⁡ ( u i ) ( 2 ) where n j is the number of fine data grids within the coarse data B j . This equation means that the coarse datum is an arithmetic average of all fine scale data within that coarse scale data grid. The fine scale data can potentially have different weights. If the data are non-linear, they can be transformed into a linear space before this algorithm is applied. In order to integrate data of different scales, both block and point data must be considered simultaneously in the kriging system. Both simple kriging (SK) and ordinary kriging (OK) can be used in this algorithm. For simplicity, the kriging theory is recalled here with simple kriging (SK). The simple kriging (SK) estimator P* OK (u) conditioned to both point and block data is written as: P SK * ⁡ ( u ) - m 0 ⁡ ( u ) = ∑ α = 1 n P ⁡ ( u ) ⁢ λ P a ⁡ ( u ) × ( P ⁡ ( u a ) - m P ⁡ ( u α ) ) + ∑ β = 1 n B ⁡ ( u ) ⁢ λ B β ⁡ ( u ) × ( B ⁡ ( v β ) - m B ⁡ ( v β ) ) ( 3 ) where P(u α ) is the fine scale data within the defined search area, e.g., P 1 and P 2 in FIG. 1 ; λ P α (u) is the corresponding kriging weight of fine scale data; B(u β ) is the coarse scale data within the defined search area, e.g., B 1 and B 2 in FIG. 1 ; λ B β (u) is the corresponding kriging weight of coarse scale data; m 0 (u) is the expected value of random variable P(u); m P (u α ) is the expected value of fine scale data random variable P(u α ); m B (ν β ) is the expected value of coarse scale data random variable B(ν β ); n P (u) is the number of fine scale data within the defined search area; n B (u) is the number of coarse scale data within the defined search area. The simple kriging weights λ α and λ β can be obtained through the kriging system: [ ⁢ C P 1 ⁢ P 1 C P 1 ⁢ P 2 … C P 1 ⁢ P n P C P 1 ⁢ B 1 C P 1 ⁢ B 2 ... C P 1 ⁢ B n B C P 2 ⁢ P 1 C P 2 ⁢ P 2 … C P 2 ⁢ P np C P 2 ⁢ B 1 C P 2 ⁢ B 2 … C P 2 ⁢ B n B ⋮ ⋮ ⋱ ⋮ ⋮ ⋮ ⋱ ⋮ C P np ⁢ P 1 C P np ⁢ P 2 … C P np ⁢ P np C P np ⁢ B 1 C p n p ⁢ B 2 … C P np ⁢ B n B C B 1 ⁢ P 1 C B 1 ⁢ P 2 … C B 1 ⁢ P np C B 1 ⁢ B 1 C B 1 ⁢ B 2 … C B 1 ⁢ B n B C B 2 ⁢ P 1 C B 2 ⁢ P 2 … C B 2 ⁢ P np C B 2 ⁢ B 1 C B 2 ⁢ B 2 … C B 2 ⁢ B n B ⋮ ⋮ ⋱ ⋮ ⋮ ⋮ ⋱ ⋮ C B n B ⁢ P 1 C B n B ⁢ P np … C B n B ⁢ P np C B n B ⁢ B 1 C B n B ⁢ B 2 … C B n B ⁢ B n B ⁢ ] ⁡ [ λ P 1 λ P 2 ⋮ λ P np λ B 1 λ B 2 ⋮ λ B n B ] = [ C P 1 ⁢ P 0 C P 2 ⁢ P 0 ⋮ C P u p ⁢ P 0 C B 1 ⁢ P 0 C B 2 ⁢ P 0 ⋮ C B n B ⁢ P 0 ] ( 4 ) where C P i P j is the covariance between fine scale data P i and P j ; C B i B j is the covariance between coarse scale data B i and B j ; P 0 is the simulation node, e.g., as shown in FIG. 1 . For the case in FIG. 1 , two fine scale data points and two coarse scale data points are found in the given defined search area. The corresponding covariance system is given in FIG. 1 . The simple kriging variance is calculated with: σ SK * ⁡ ( u ) = C ⁡ ( 0 ) - ∑ α = 1 n P ⁡ ( u ) ⁢ λ P α ⁡ ( u ) × C ⁡ ( u α - u ) - ∑ β = 1 n B ⁡ ( u ) ⁢ λ B β ⁡ ( u ) × C ⁡ ( v β - u ) ( 5 ) where P* SK (u) represents the kriging mean and σ* SK (u) represents the variance, must be calculated for each simulation node to evaluate the local conditional probability distribution. Conventionally, covariance values are calculated for a given model as needed. However, to improve the kriging system construction efficiency, all possible covariance values are calculated and stored in the form of covariance maps prior to modeling. The covariance values are then retrieved from the covariance maps as needed. In geostatistical modeling, the way to handle heterogeneity is through a regionalized variable parameterization by the variogram or covariance. Referring to FIG. 3A , a covariance curve with varying spatial separation distance (lag distance) is provided in one direction. The spatial correlation decreases as the lag distance increases. If the covariance curves are plotted in all directions on a two dimensional plane, a covariance map is created similar to that in FIG. 3B . Similarly, a covariance cube can be generated in a three dimensions as shown in FIG. 3D . Referring to FIG. 3C , the covariance map size is about two times larger than the defined study area of interest in the x, y and z direction in order to include all omni-directional covariance values needed in the kriging system. However, the covariance map size can be significantly reduced according to the symmetric property of covariance: Cov( u 0 ,u ( x,y,z ))=Cov( u 0 ,u ( −x,−y,−z ))  (6) where Cov denotes covariance; u 0 denotes the origin of variogram lag distance and u(x, y, z) is the end of the variogram lag. The equation indicates that the covariance map is central symmetric. A covariance map can be fully represented by about half of itself, as shown in FIG. 3C and FIG. 3E . In downsim, only about half of the covariance map is stored. Like other geostatistical algorithms, downsim performs simulation in Cartesian grids instead of real stratigraphical grids. All coarse scale data can be assumed to have the same size and shape in the Cartesian grid system. However, in the present invention the number of block covariance maps can be reduced from the number of coarse grid cells in bssim to one, which significantly alleviates the burden of memory requirement. A flow chart of steps may be utilized by embodiments of the present invention illustrated in FIG. 7 . Some of the blocks of the flow chart may represent a code segment or other portion of the computer program. In some alternative implementations, the functions noted in the various blocks may occur out of the order depicted in FIG. 7 . For example, two blocks shown in succession in FIG. 7 may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order depending upon the functionality involved. In step 100 , covariance maps are generated and stored. Prior to commencing simulation, the point and block-to-point covariance maps, as shown in FIG. 2B , are generated and stored once for all subsequent simulations and realizations. The point covariance map is generated by calculating point covariance values between a first base point and all points within the expanded area. For example, FIG. 3B provides a two-dimensional point covariance map and FIG. 3D provides a three-dimensional covariance map. The block-to-point covariance map is generated by calculating the block-to-point covariance values between a first base block and all points within the expanded area. For example, FIG. 4B provides a first base block 200 within an expanded area 210 . FIG. 4A depicts the block-to-point covariance map within the expanded area 210 . According to covariance symmetric properties, only approximately half of the original point and block-to-point covariance maps are retained in memory. As previously discussed, FIG. 3C is approximately half of the original two-dimensional point covariance map depicted in FIG. 3B . Likewise, FIG. 3E is approximately half of the original three-dimensional point covariance map depicted in FIG. 3C . Furthermore, covariance symmetry provides that only about half of the original block-to-point covariance map is retained in memory, as shown in FIG. 4C , which are the block-to-point covariance values between the first base block 200 of FIG. 4D and all points within the expanded area 210 . The reduced point and block-to-point covariance maps are stored in the downsim algorithm. In step 102 , a simulation node is selected. The simulation is performed on a node by node basis, sequentially following a random path within the simulation area. For example, FIG. 2A depicts a simulation node u with neighboring fine-scaled and coarse-scale data. In step 104 , the previously stored point and block-to-point covariance maps are retrieved and searched. The point and block-to-point covariance maps are searched and the neighboring point and block-to-point covariance values surrounding the simulation node u are searched and retrieved. Given the point and block-to-point covariance maps, the covariance value between the first base block and a second block, referred to as a block-to-block covariance, is obtained by calculating the average point covariance values over the area covered by the second block. FIG. 5 provides four different scenarios in which the location of the blocks affects the calculation approach. FIG. 8A provides the simplest scenario in which the location of the first base block, block # 1 , coincides with the base case in FIG. 4C . In FIG. 5A , the covariance values between block # 1 and the block # 2 is simply the average of the block-to-point covariance values over the location of the second block. In FIG. 5B , the covariance between block # 1 and the block # 2 has an opposite direction than depicted in FIG. 5A . According to the symmetric property of covariance, the covariance values in FIG. 5B are the same as the covariance values in FIG. 5A . Thus, the covariance values are obtained by calculating the average block-to-point covariance values over the area covered by the second block. In FIG. 5C , the location of block # 1 is different from the base case in FIG. 4C . Thus, the two blocks are simultaneously shifted such that block # 1 is moved to the base case block location as shown in FIG. 4C . The shifted blocks and the original blocks have the same block-to-block covariance value. This covariance value is obtained by calculating the average block-to-point covariance values over the area covered by the second block. Finally, in FIG. 5D the two blocks are aligned in a different orientation. The second block falls on the left side of the block-to-point covariance map. Similarly, the block-to-block covariance value is calculated by averaging the block-to-point covariance values within the second block. Once the covariance value of the two blocks is computed, the covariance value is stored and can be directly retrieved for the block pairs with the same spatial configuration in subsequent simulation. All block-to-block covariance values required for stochastic simulation are able to be obtained from the single stored covariance map. As the simulation proceeds, a block-to-block lookup table is constructed, thus avoiding repeated calculations of block covariance with the same lag distances in the subsequent simulation. Similar to the block-to-block covariance calculation, block-to-point covariance values can be retrieved from the stored block covariance map, as shown in FIG. 6 . In many cases both shifting movements and symmetric transformations are needed in order to find the matched block-to-point pair configuration in the stored block-to-point covariance map. Point covariance values can be retrieved from the point covariance map based on symmetric properties. Alternatively, the point covariance values can be calculated at each simulation location using the variogram equations. As opposed to block covariance, both approaches for point covariance are acceptable in terms of CPU efficiency because the real-time point covariance calculation is fast. In step 106 , a kriging system is constructed. Based on the retrieved point and block related covariance values, a local kriging system, as shown in FIG. 2C , is built: [ C PP C _ PB C _ BP C _ BB ] ⁡ [ λ P λ B ] = [ C P 0 ⁢ P C _ P 0 ⁢ B ] ( 7 ) The point covariance value (C PP ) and the block-related covariance values ( C PB , C BP , C BB , C P 0 P , C P 0 B ) can be retrieved or calculated from the prebuilt point and block-to-point covariance maps ( FIG. 2B ) using the covariance search method as described in step 102 . In step 108 , the kriging system is solved to obtain the kriging weights, λ P and λ B . In step 110 , the local mean and variance values are calculated. The local mean and variance values are calculated with the standard kriging estimator and variance calculation equations. Since the simulation is performed in the original space, not in the Gaussian space as in sequential Gaussian simulation, the local distribution does not have to be in a Gaussian form. It can be of any type, including a user-defined histogram. To make the simulated model honor the global target histogram, one draws the simulated values within the target histogram interval defined by the local kriging mean and variance. Such technique is also described, for example, in the following document: Soares, A., 2001 , “Direct sequential simulation and cosimulation ”, Mathematical Geology, p. 33, 911-926. In step 112 , a value is simulated and assigned to the location. A value is drawn from the sampling interval, of step 110 , and assigned to the location u, see FIGS. 2E and 2F . In step 114 , move to the next node. Move to next node following a predefined random path, as shown in FIG. 2G , and repeat the process until all nodes are simulated resulting in a downscaled realization, as shown in FIG. 2H . Finally, the random number is changed and a new-equally probably realization is generated by repeating the above workflow if user wants to build multiple models for uncertainty analysis. In an embodiment, the method can be implemented as a plug-in. In another embodiment, the method can be implemented as a plug-in of a reservoir modeling software platform. In yet another embodiment, the method can be implemented as a plug-in of a reservoir modeling software platform such as Petrel™. In an embodiment, the method can be applied to steam assisted gravity drainage (SAGD) geomodel downscaling. Example Geocellular models typically have grid cell resolution of tens or hundreds feet, and cover large areas. However, SAGD is conducted in relatively small areas and needs much finer grid cell dimensions (several feet) in the direction perpendicular to the horizontal wells to capture the steam chamber development process. Furthermore, it is neither reasonable nor practical to build many isolated small SAGD geomodels ignoring the regional geology and prebuilt coarser-scale geomodels. Downsim enables geomodelers to build fine-scale models for SAGD thermal simulation while maintaining the consistency between the SAGD models and the existing normal geomodels. Referring to the SAGD geomodel resealing workflow in FIG. 11 , both upscaling and downscaling are involved. To save thermal simulation time, the cells are upscaled in the horizontal well direction. And the cells are downscaled in the perpendicular direction. Appropriate upscaling methods can be used for different petrophysical properties. A thermal pilot area of interest (AOI) is then extracted from the resealed grid model. The initial well logs are re-blocked to the new grid, which will be used as hard data for downscaling. Next, downscaling is performed with downsim. The downscaled property incorporates hard data information; has fine-scale variations within coarse grids; and smoothes the coarse grid boundary effects. Large scale features in the coarse model are preserved in the downscaled models, and subcoarse-grid heterogeneities are also modeled. Those fine-scale property variations can have significant impacts on SAGD thermal simulation. For the quality control (QC) purpose, the reproductions of the input coarse porosity data, variogram and histogram, etc., need to be checked before the geomodel is finalized for thermal simulation. This is a fast algorithm because of its novel block covariance map storage and retrieving methods. Many repeated CPU intensive block covariance calculations are saved. This is a memory-efficient algorithm because all the block related covariance values can be computed from one single block-to-point covariance map. In bssim (Liu and Journel 2009), the block-to-point covariance map for each coarse block is stored, in which the memory cost increases dramatically as the number of blocks increases. This algorithm makes the previously CPU and memory prohibitive downscaling process become practical. Methods consistent with the present teachings are especially well-suited for implementation by a computing element. The computer may be part of a computer network that includes one or more clients computers and one or more server computers interconnected via a communications system such as an intranet or the internet. It will be appreciated, however, that the principles of the present invention are useful independently of a particular implementation, and that one or more of the steps described herein may be implemented without the assistance of the computing device or with the assistance of a plurality of computing devices. The present invention can be implemented in hardware, software, firmware, and/or combinations thereof. In a preferred embodiment, however, the invention is implemented with a computer program. The computer program and equipment described herein are merely examples of program and equipment that may be used to implement the present invention and may be replaced with other software and computing devises without departing from the scope of the present teachings. Computer programs consistent with the present teachings can be stored in or on a computer-readable medium residing on or accessible by the computer for instructing the computer to implement methods as described herein. The computer program preferably comprises a plurality of code segments corresponding to executable instructions for implementing logical functions in the computer and other computing devices coupled with the computer. The computer program can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device, and execute the instructions. It will be understood by persons of ordinary skill in the art that the program may comprise a single list of executable instructions or two or more separate lists, and may be stored on a single computer-readable medium or multiple distinct media. In the context of this application, a “computer-readable medium” can be any means that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electro-magnetic, infrared, or semi-conductor system, apparatus, device, or propagation medium. More specific, although not inclusive, examples of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable, programmable, read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc (CD) or a digital video disc (DVD). The computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. The preferred embodiment of the present invention has been disclosed and illustrated. However, the invention is intended to be as broad as defined in the claims below. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described in the present invention. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims below and the description, abstract and drawings not to be used to limit the scope of the invention.

A computer-aided method of downscaling a three-dimensional geological model by generating numerical stochastic fine-scale models conditioning to data of different scales and capturing spatial uncertainties which involves a downscaling algorithm.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to switch mechanisms and, more particularly, to switch mechanisms which incorporate a cam surface shaped to provide a damper so that overtravel of a switch plunger can be prevented when the plunger is suddenly released from a depressed position. 2. Description of the Prior Art Many types of switch mechanisms are well known to those skilled in the art. A particular application of switch mechanisms of this type relate to pushbutton switches that comprise a plunger that is moveable relative to a base along an axis and which causes actuation of switching components when the plunger is depressed. Typically, the plunger is connected to a button that is depressible by a human finger. Some switch mechanisms cause actuation of a switch upon each depression of the button and plunger while other switch applications, referred to as alternate action devices, actuate on one push and release of the button and undo the actuation on a subsequent push and release of the button. Regardless of the specific application of the switch mechanism, most known mechanisms utilize cams and cam followers to control the sequence of operations resulting from depression of the button and plunger. U.S. Pat. No. 4,254,315, which issued to Stevens on Mar. 3, 1981, discloses a pushbutton switch with a safety stop. The switch utilizes a locking mechanism that includes a cam member with a groove of the cam member being engaged by a cam follower. The groove is in the form of a closed loop path and the pushbutton is linked to the locking mechanism so that movement of the pushbutton moves the cam follower relative to the cam member along the groove. The cam follower moves only in an up and down direction in line with the axis of movement of the button and the cam moves in a direction perpendicular to that axis. U.S. Pat. No. 3,523,168, which issued to Holmes on Aug. 4, 1970, describes a pushbutton switch which has a positive plunger safety stop carried in its casing. The switch has a tubular casing that receives a pushbutton at the upper casing end and has a lower switch at the lower casing end. The pushbutton is moveable inward into the upper casing end by an initial pushing inward followed by moving upwardly by a release counterspring action. The switch comprises a plunger guide that can have a plurality of grooves in which teeth of a plunger disc reciprocate vertically so that the plunger can not substantially rotate relative to the plunger guide. The guide has an upper circular edge above the grooves and the guide is enlarged radially outwardly to provide shoulders to hold the upper end and the lower bottom of the plunger guide between a lamp contact block and the bottom of a casing structure. One serious problem that can occur during the operation of a pushbutton switch is the sudden release of the button while it is fully depressed relative to its housing. Since most pushbutton switches utilize one or more compression springs to urge the button and plunger outward relative to the case or housing, a sudden snap-release of the button can result in the rapid movement of the plunger and button away from the base of the switch to result in the button exceeding its normal unactuated position. In some extreme cases, the pushbutton and plunger can actually disconnect from the housing and be projected out of the pushbutton housing. In less extreme, but equally deleterious circumstances, the pushbutton can become separated from the plunger while remaining within the housing. The subsequent actuation of the device will require an initial force to reconnect the pushbutton and plunger followed by another force to actually actuate the device. Another possible result from a sudden snap-release is the movement of the plunger to a position normally assumed only during a relamping procedure as provided for in U.S. Pat. No. 4,254,315 described above and in U.S. patent application Ser. No. 973,132 which was filed by Cummins and Shaw on Nov. 6, 1993 and assigned to the assignee of the present application. The plunger could react to a snap-release by moving to the relamping position and require two sequential forces, separated by a release, to actuate the device. All of these possible results are seriously disadvantageous. In view of the above problem, it would be significantly beneficial if a means were provided to prevent this type of overtravel in response to a snap-release of a button and plunger of a pushbutton switch. SUMMARY OF THE INVENTION The present invention provides a switch mechanism that comprises a means for preventing overtravel of the switch plunger in response to a snap-release when the plunger is depressed to its position most proximate the base of the switch. In a preferred embodiment of the present invention, the switch mechanism comprises a base, a cam follower which is attached to the base and a plunger that is moveable both toward and away from the base along a first axis. A cam is attached to the plunger and disposed in sliding contact with the cam follower. The present invention also provides a means for preventing overtravel of the plunger in a direction away from the base in response to a sudden release of the plunger from an actuated position. In other words, a most preferred embodiment of the present invention comprises a means for preventing the plunger from moving away from the base by an excessive amount in response to the force provided by springs in a direction along the first axis when the button of the switch is snap-released while it is fully depressed and the springs are fully compressed. The preventing means in a preferred embodiment of the present invention comprises a cam surface that is formed in the cam directly below a position where the cam follower is disposed when the plunger is in its most proximate position relative to the base. The cam surface is sloped relative to the first axis by a predetermined angular offset. In a switch made in accordance with the present invention, the switch mechanism further comprises a housing in which the base is disposed. In addition, a button is connected to the plunger and a switching component is disposed proximate the base for actuation by the plunger. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully and clearly understood from a reading of the Description of the Preferred Embodiment in conjunction with the drawing, in which: FIG. 1 shows an exploded view of a pushbutton switch in which the present invention can be employed; FIG. 2 shows a switch known in the prior art; FIG. 3 shows a cam of the switch illustrated in FIG. 2; FIGS. 4A, 4B and 4C show sequential relative positions between a cam and a cam follower in response to the release of a plunger when the plunger is fully depressed relative to a base; FIG. 5 represents a summary illustration showing the positions illustrated in FIGS. 4A, 4B and 4C; and FIGS. 6A and 6B show two perspective views of the cam of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Throughout the Description of the Preferred Embodiment, like components will be identified by like reference numerals. FIG. 1 shows an exploded view of a pushbutton switch that is suitable for use in association with the present invention. In FIG. 1, a base is shown having an opening 16 formed therein. The base 10 is associated with two switching components, 12 and 14. The base 10 is connected to a cam follower 20 that is urged inward toward opening 16 by spring 22. The base 10 and its associated components are disposed within housing 26. With continued reference to FIG. 1, a plunger 32 is provided with an attached extension 34 and is moveable in a direction along first axis 30. In FIG. 1, this movement is in an upward and downward direction relative to base 10. The extension 34 is provided with an opening 40 that is shaped to receive a protrusion 42 of cam 50. The plunger 32 is shaped to receive actuators, 60 and 62, so that the plunger 32 can carry the actuators and move them into contact with the switching components, 12 and 14, when the plunger 32 is moved into its downward position. The cam 50 has a protrusion 54 at its upper portion to limit the rotational movement of cam 50 with respect to the plunger 32. Four lamps, 71, 72, 73 and 74 are shown in FIG. 1 along with a lamp holder 80. A seal 82 is associated with the lamp holder 80 and a suppressor 94 is disposed thereon. Also shown in FIG. 1 are springs, 84 and 86, and light pipes, 96 and 98. Stationary contacts, 90 and 92, are used in association with the lamp holder 80. A button 100 is shown at the top portion of FIG. 1. A travel stop 107 provides a tether that permits the lamp structures above the tether in FIG. 1 to be lifted upward relative to the plunger 32 without complete disconnection therebetween. Compression springs 109 are used to urge the plunger 32 upward and away from base 10. In other words, when the button 100 is pushed downward the springs 19 are compressed and the switching components, 12 and 14 are actuated. When the downward pressure on button 100 is released, springs 109 urge the plunger 32 upward. At the bottom portion of FIG. 1, tubular contacts 150 extend through holes in base 10. Compression springs 160 operate in association with contacts 150, adapter 170 and contacts 180 to maintain electrical contact between the lamps, 71, 72, 73 and 74, and contacts 180. A plate 190 is also provided. Compression springs 160 and springs 109 exert an upward force that pushes plunger 32 away from base 10 to return it to its neutral position when a downward force on button 100 is released. The problems solved by the present invention can be described with respect to FIG. 1. If the button 100 is pushed downward to cause plunger 32 to move against the force of springs 109 and 160 to the fully depressed position of plunger 32, springs 109 and 160 will be at their maximum state of potential energy. If, when the plunger 32 is fully depressed as described above, the button 100 is suddenly snap-released, the full force of springs 109 and 160 could possibly propel the plunger 32 and button 100 in an upward direction along the first axis 30 away from base lo with sufficient speed to cause an overtravel condition to occur. This overtravel condition could result from relative movement between the cam follower 20 and the cam 50 beyond their normal operational positions. This overtravel, if it occurs, would be caused by the full release of the potential energy of springs 109 and 160 and the sudden conversion of that energy to kinetic energy in the plunger 32 and button 100. FIG. 2 shows a simplified illustration of a pushbutton switch that is known to those skilled in the art. The button 200 is connected to a shaft 202 that has a cam follower 204 attached to it. A cam structure 208 is provided with a closed-loop groove 210 in which the cam follower 204 is disposed. In FIG. 2, reference numeral 214 is used to identify an extension of shaft 202. As can be seen, shaft extension 214 is disposed in contact with an actuator arm 216 of a switching component 218. When button 200 is depressed, shaft 202 and 214 move downward under limitations provided by groove 210 on cam follower 204. With continued reference to FIG. 2, it should be understood that cam 208 is limited to move left and right in FIG. 2 along rails or guides within the switch structure. This movement of the cam 208 is more fully described in U.S. Pat. No. 4,254,315 which has been discussed above. FIG. 3 shows the cam 208 of U.S. Pat. No. 4,254,315 that is also shown in FIG. 2. The cam 208 is provided with a groove 210 in which the cam follower 204 is disposed. The sequential positions of the cam follower 204 within groove 210 are illustrated by the numbered circles within the groove. With reference to FIGS. 2 and 3, it can be seen that the cam follower 204 is moveable with the button 200 and not attached to a base of the switch. In addition, the cam 208 is limited in its movement to an axis that is perpendicular to the direction of movement of the button 200 and shaft 202. The cam 208 is not attached to a plunger or to the button 200. FIGS. 4A, 4B and 4C show sequential positions of the cam follower 20 of the present invention relative to the cam 50. FIG. 4A illustrates the position of cam follower 20 relative to cam 50 when the plunger 32 is fully depressed downward toward the base 10 in FIG. 1. Since the cam follower 20 is attached to base 10, and the cam 50 moves downward into opening 16 in coordination with the downward movement of extension 34 of plunger 32, the relative position of the cam follower 20 moves to its uppermost location on cam 50. The position of cam follower 20 in FIG. 4A will be referred to below as position 1. FIG. 4B shows the cam follower 20 at a second position on the cam 50 in response to a release of button 100 and the rise of plunger 32 in response thereto. Since the cam 50 rises in result of the urging by springs 109 and 160 when button 100 is released, the relative position of can follower 20 moves downward relative to the cam 50. This relative downward movement is illustrated by arrow A. If the button 100 is snap-released when the plunger 32 is fully depressed in the direction toward base 10, the stored energy in springs 109 and 160 could possibly be sufficient to propel the plunger 32 and all of its attached components upward away from base 10 with sufficient speed to cause the moving parts to travel past their intended unactuated position away from base 10. However, with reference to FIG. 4B, it can be seen that a cam surface 260 is provided directly below the position of cam follower 20 when the cam 50 and plunger 32 are fully depressed. As a result of the location of surface 260, the upward movement of cam 50 causes cam surface 260 to strike the cam follower 20 and deflect the cam follower 20 toward the left relative to the location of cam 50. As described above, the cam follower 20 is attached to base 10 and its movement is therefore restricted. The cam 50, on the other hand, is moveable along axis 30 in response to movement of the extension 34 of plunger 32. Therefore, in the discussion of the present invention in conjunction with FIGS. 4A, 4B and 4C, it should be remembered that cam follower 20 is the stationary component attached to base 10 and that cam 50 is the moveable component attached to extension 34 of plunger 32. In addition, it should be noted that the relative movement of protrusion 42 within opening 40 permits the cam 50 to move in a direction perpendicular to axis 30 and also permits cam 50 to rotate relative to extension 34 and plunger 32 within the limits provided by protrusion 54. Therefore, when cam follower 20 strikes surface 260, as shown in FIG. 4B, the cam 50 will be cause to move toward the right in FIG. 4B in reaction to this contact. However, the kinetic energy possessed by the plunger 32 and all of the moveable components attached to it will be dissipated and diverted by the sloping surface of cam surface 260. FIG. 4C shows the position of the cam follower 20 after it has been deflected by surface 260 when cam follower 20 was at the position identified by the dashed circle and numeral 2. The position of cam follower 20 in FIG. 4C will be referred to below as position 3. The position of cam follower 20 in FIG. 4C is the rest, or neutral, position from which normal actuation can occur as a result of a subsequent depression of button 100 and plunger 32. In FIGS. 4A, 4B and 4C, a cam surface 270 is also identified toward the bottom portion of cam 50. Although not directly related to the operation of the present invention, the circular depression 270 in cam 54 is intended for use when the plunger 32 and button 100 are pulled upward and away from base 10 by an operator during a relamping procedure by which lamps 71, 72, 73 and 74 are changed. The operation of surface 270 and other cam surfaces. Not discussed above are described in detail in U.S. patent application Ser. No. 973,132 filed by Cummins and Shaw on the same date as the present application and which is assigned to the Assignee of the present application. Although that invention and the present invention share some similarities in shape, the relevant structure of the present invention and the function and objective thereof are distinct from that described in the Cummins and Shaw application. FIG. 5 illustrates cam 50 with the three relevant positions identified thereon. The path taken by cam follower 20 from position 1 to position 2 is identified, as above, by arrow A and the short path taken by cam follower 20 between location 2 and location 3 is identified by arrow B. As described above, the movement of cam follower 20 between location 2 and location 3 is caused by its deflection against cam surface 260. It is this deflection that diverts the force caused by the conversion of potential energy of springs 109 and 160 to the kinetic energy of the plunger 32 and attached moveable components. The deflection of movement by cam surface 260 prevents the kinetic energy from causing the plunger and related components to overtravel its intended unactuated position. FIGS. 6A and 6B illustrate two perspective views of the cam surfaces of cam 50. In FIGS. 6A and 6B, the surface on which the cam follower 20 rests when at position 1 is identified as SA, the surface on which the cam follower rests when at position 2 is identified as SB and the position on which the cam follower 20 rests when in location 3 is identified as SC. These surfaces are not clearly visible in FIG. 6B because of the obstruction by other protruding surfaces of the cam face. When the cam follower moves, along the path identified by arrow A, from surface SA to the deflecting surface 260, it is diverted toward the center portion of cam 50 by the slope of surface 280. Eventually, cam follower 20 strikes surface 260 and is deflected toward surface SC in the direction represented by arrow B. It should be understood that when cam follower 20 strikes surface 260 it is proximate the surface identified as SB in FIG. 6A. In FIGS. 6A and 6B, the protrusion 54 is shown at the top portion of cam 50. Although not directly relevant to the present invention and not shown in FIG. 1, plunger 32 comprises two travel limit stops which are disposed on opposite sides of protrusion 54 when cam 50 is attached to extension 34 of plunger 32. These travel stops operate in association with protrusion 54 to limit the rotation of cam 50 relative to plunger 32. Although the present invention has been described with significant specificity and illustrated in detail to shown one particularly preferred embodiment of the present invention, it should be understood that alternative embodiments are within its scope.

A damper is provided for a switch mechanism to prevent overtravel in response to a snap-release of a plunger when it is fully depressed. If no precautions are taken to prevent this type of overtravel, springs which urge the plunger away from its base can provide sufficient force to propel the plunger away from the base with sufficient speed and force to cause the plunger to travel past its intended unactuated position. The present invention utilizes a sloped cam surface which acts as a damper to divert the direction of travel of a cam follower relative to a cam and thereby dissipate the kinetic energy of the plunger, button and moveable components attached to the plunger.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to an exposure control system for a photographic apparatus and more particularly to an exposure control system having a follow focus capability for a photographic apparatus of the type having means for initiating the energization of a source of artificial light to illuminate a photographic screen. 2. Description of the Prior Art The exposure system of a photographic camera when operated in conjunction with a flash or transient illumination is ordinarily adjusted as a function of the levels of illumination anticipated at the scene being photographed. An evaluation based on the anticipated level of illumination may be made based upon an application of the inverse square law of light energy propagation which may additionally be weighted to anticipate spurious room reflections. under this law, the light energy available from a given source is considered to vary inversely with the square of the distance from that source. Accordingly, to make an appropriate exposure mechanism adjustment for flash photography, source to subject distance is derived and the value of this distance is utilized to compute an appropriate exposure value or illuminational factor. In some camera designs, exposure control adjustment for flash operation is effected automatically by incorporating within the apparatus what is termed as a follow focus system. With a follow focus arrangement, aperture adjustment or flash illumination output control is mechanically coupled with the range finding or focusing system of a camera. In effect, a follow focus control represents a second exposure control system for a camera. As such, its presence necessarily contributes to the size and complexity of the camera. A follow focus control system for an exposure control system is described in a U.S Patent entitled "Focus Responsive Exposure Control System" by V. K. Eloranta and E. K. Shenk, Ser. No. 3,750,543, filed Apr. 19, 1971, and assigned in common herewith. The patent describes a second flash mode control system wherein an electromagnetic device, such as a solenoid, is selectively maneuvered and energized to extend its plunger to arrest position of exposure aperture blades in accordance with focal setting. A complete follow focus system is described in a U.S. Patent entitled "Apparatus and System for Flash Photography" by Lawerence M. Douglas, filed Mar. 15, 1973, Ser. No. 3,832,722 and assigned in common herewith. This system achieves a requisite compactness to meet the overall camera design described in U.S. Pat. No. 3,714,879 and incorporates means for selective use of the follow focus system exclusively during the flash illuminated exposure mode of operation. The above follow focus system additionally provides a trim function to accomodate for slight variations in the sensitometric characteristic of the film as well as to insert a modicum of personal or overriding control over the automated system. The trim control has only one control element for operation in this manner substantially reducing the possibility that a camera operator may become confused or overlook a requirement for providing a trim control for that mode of operation for which he is currently using. It is therefore a primary object of this invention to provide an improved exposure control system with follow focus capability for a photographic apparatus of the type having means for initiating the energization of a source of artificial light to illuminate a photographic scene. It is also an object of this invention to provide an improved exposure control system with follow focus capability for a photographic apparatus wherein a selected aperture may be uniformly trimmed by a predetermined number of F/stops regardless of the actual focus setting of the photographic apparatus. It is a further object of this invention to provide an improved exposure control system with follow focus capability wherein the mechanism may be precisely calibrated despite the cumulative effect attributable to the dimensional variations of the individual components albeit such variations remain within prescribed tolerances. It is an additional object of this invention to provide an improved exposure control system having follow focus capability wherein the geometrical orientations of the mechanical components are determined in a select manner to provide uniform adjustment of the exposure aperture through a trim mechanism irrespective of the actual focus setting. Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the mechanism and system possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure. SUMMARY OF THE INVENTION An exposure control system and mechanism is described for a photographic camera apparatus of the type having means for initiating the energization of a source of artificial light to illuminate a photographic scene. The control system includes means for defining an optical path together with an optical objective adjustable to image the photographic scene at an image plane. There are also included focusing means movable to adjust the optical objective, together with exposure means having at least one element movable along a locus of travel for defining a range of apertures over the optical path in correspondence with the exposure element movement. Interceptor means are provided for selective rotation about a first pivot point in spaced relation with respect to the exposure element locus of travel and including an interceptor edge for arresting movement of the exposure element along the locus of travel to define a select aperture value over the optical path. Link means driveably connect to rotate the interceptor means about the first pivot point in order to position the interceptor edge at locations along the locus of exposure element travel defining the select exposure aperture. Cam means are provided for movement in correspondence with the focusing means movement and driveably contact the link means in order to rotate the interceptor means about the first point of pivot thus locating the interceptor edge at a select position establishing an aperture value corresponding with the level of the artificial illumination anticipated at the photographic scene. The exposure means may additionlly include a walking beam rotatable about a second pivot point and operatively connecting to at least one element for movement in correspondence therewith to define a range of apertures over the optical path. The camera apparatus may additionally be of the type which is operative in an ambient mode responsive to the light level of a scene being photographed and in a flash mode responsive to the level of artificial illumination anticipated at the scene in which case there must also be provided a drive means to selectively actuate the interceptor means to move into the exposure means element locus of travel during the flash mode of operation. One distinguishing feature of the herein described invention relates to the cam means surface which is arranged substantially concentric to the optical path. Another feature of the herein described invention relates to an adjusting means which may be provided to precisely locate the first pivot point about which the interceptor means rotates in order to adjust for the cumulative effect of dimensional variations in the individual components of the exposure control system when mass produced for a commercial camera. BRIEF DESCRIPTION OF THE DRAWINGS The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with other objects and advantages thereof, will be best understood from the following description of the illustrated embodiment or when read in connection with the accompanying drawings or when like members have been employed in the different figures to note the same parts and wherein: FIG. 1 is a perspective view of a photographic camera embodying the exposure control system of this invention; FIG. 2 is a cutaway front view of the exposure control system of FIG. 1; FIG. 3 is a cutaway front view of the exposure control system of FIG. 2; FIG. 4 is a cutaway back view of the exposure control system of FIG. 1; FIG. 5 is a enlarged side view showing a broken away portion of the exposure control system of FIG. 1; FIG. 6 is an enlarged front view showing a broken away portion of the exposure control system of FIG. 1; FIG. 7 is a broken away cross-sectional view taken across the lines 7--7 of FIG. 4; FIG. 8 is a broken away cross-sectional view taken across the lines 8--8 of FIG. 4; and FIG. 9 is a broken away cross-sectional view taken across the lines 9--9 of FIG. 8. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, it can be seen that the exposure control system of this invention is disposed within an exposure housing 10 comprising a baseblock casting 12 selectively machined to support the components of the exposure mechanism. Surrounding the front and top of the casting 12 there may be provided a cover 16 which includes openings through which protrude manually adjustable trim and focus bezels shown at 18 and 20 respectively. Intermediate the baseblock casting 12 and the front cover 16 there is provided a lens housing casting 14, the central portion of which includes a light entering exposure opening 22 which defines the maximum available exposure aperture for the system. an objective or taking lens 24 is provided in overlying relation to the light entering opening 22 wherein the objective lens 24 may comprise a plurality of elements retained in predetermined spaced relation by a cylindrical lens mount assembly 28 which is externally threaded for toothed engagement with the internally threaded focus bezel 20. Bezel 20 is made rotatable with respect to the lens housing casting 14 and front cover 16 to provide translational movement of the elements of lens 24 along a central optical axis 30 of the optical path of the housing 10. As is readily apparent, the center optical axis 30 of the optical path is illustrated as being normal to the plane of the drawings in FIGS. 2-4. The rotation of focus bezel 20 may be carried out by manual rotation to provide displacement of the elements of objective lens 24 for focusing of image carrying rays through the light entering exposure opening 22 to a rearwardly positioned film plane 32 by way of a reflecting mirror 34 when the system is embodied in a suitable film exposure chamber 36. Immediately behind the objective lens 24 and light entering exposure opening 22 there are supported two overlapping shutter blade elements 38 and 40 which will be subsequently described in greater detail herein. Extending from the top of the housing 10 is a shutter release button (not shown), the depression of which causes the commencement of an exposure cycle. A pair of scene light admitting primary apertures 42 and 44 are provided respectively in the blade elements 38 and 40 to collectively define a progressive variation of effective aperture openings in accordance with longitudinal and lateral displacement of one blade element with respect to the other blade element in a manner fully described in a United States Patent Application intitled "Camera with Pivoting Blades" by George D. Whiteside, filed July 2, 1974, and assigned in common herewith. The apertures 42 and 44 are selectively shaped so as to overlap the light entering exposure opening 22 thereby defining a gradually varying effective aperture size as a function of the position of blades 38 and 40. Each of the blades, 38 and 40, may additionally be configured to have corresponding photocell sweep secondary apertures shown respectively at 46 and 48. Secondary apertures 46 and 48 may be configured in correspondence with the shapes of scene light admitting primary apertures 42 and 44. As is readily apparent, the secondary apertures 46 and 48 also move in correspondence with the primary apertures 42 and 44 to define a small secondary effective aperture for admitting the passage of light from the scene being photographed to a light detecting station shown generally at 49. The light detecting station 49 includes a light sensitive circuit having both a photocell and control circuit (not specifically shown) which collectively operate to terminate an exposure interval as a function of the amount of light received through the secondary effective aperture as defined by the overlapping photocell sweep apertures 46 and 48. An exposure control mechanism embodying a light detecting station of the above described type is described in more detail and claimed in a U.S. Patent entitled "Exposure Control System" by V. K. Eloranta, No. 3,641,889. Projecting from the baseblock casting 12 at a location spaced laterally apart from the light entering exposure opening 22 is a pivot pin or stud 50 which pivotally and translatively engages elongate slots 52 and 54 formed in respective shutter blades elements 38 and 40. Pin 50 may be integrally formed with the baseblock casting 12 and blade elements 38 and 40 may be retained in engaging relation with respect to the pin 50 by any suitable means such as peening over the outside end of pin 50. The opposite ends of the blade elements 38 and 40 respectively include extended portions which pivotally connect to a walking beam 56. The walking beam 56 in turn is disposed for rotation about a laterally extending stud 60 which journals a centrally disposed elongated integral shaft 58 extending from the back side of the walking beam 56. The stud 60 protrudes laterally from an integral extension 62 of the baseblock casting 12. A centrally disposed integral pin 64 extends from the opposing forward side of the walking beam 56 and is in turn journalled into rotation by a bushing 66 in the lens housing casting 14. In the preferred mode, the walking beam 56 is pivotally connected at its distal ends to the shutter blade elements 38 and 40 by respective pin members 67 and 68 which extend from the walking beam 56. Pin members 67 and 68 are preferably circular in cross section and extend through respective circular openings 70 and 72 in respective blade elements 38 and 40 so as to slidably engage respective arcuate slots or tracks 74 and 76 which may be integrally formed within the baseblock casting 12. The arcuate tracks 74 and 76 operate to prohibit disengagement of the blade elements 38 and 40 from their respective pin members 67 and 68 during exposure control system operation. A tractive electromagnet device in the form of a solenoid 78 is employed to displace the shutter blades 38 and 40 with respect to each other and the casting 12. The solenoid 78 may be of conventional design carrying an internally disposed cylindrical plunger unit 80 which retracts inwardly into the body of the solenoid upon energization thereof. The solenoid plunger unit 80 is affixed to the walking beam 56 by means of a guideway 82 at the outward end of the plunger 80 which guideway slidably engages a pivot pin 84 extending laterally from an integral radial crank arm portion 86 of the elongated shaft 58. In this manner longitudinal displacement of the plunger unit 80 will operate to rotate the walking beam about the lateral stud 60 and bushing 66 so as to appropriately displace the shutter blade elements 38 and 40. The blade elements 38 and 40 are continuously urged into positions defining the largest effective aperture over the light entry exposure opening 22 by a biasing tension spring 88. The movable end of spring 88 engages a slot 90 in a second integral radial arm portion 92 extending outwardly from the elongated shaft 58 while the stationary end of spring 88 is grounded by connection to a pin 93 extending from the baseblock casting 12. With the spring connection herein described, the exposure control mechanism of this invention is biased into a normally opened orientation and the shutter blade elements 38 and 40 are drawn to their closed position only while solenoid 78 is energized. Consequently, energization of the solenoid 78 prevents the shutter blades 38 and 40 from moving toward their maximum aperture opening under the urging of spring 80. However, as should be readily understood, the exposure control mechanism of this invention would be equally applicable to photographic systems where the blades 38 and 40 are spring biased in a normally closed position. The exposure control system is herein described in relation to a photographic camera of the non-single lens reflex type although the intended scope of the invention is by no means so limited and cameras of the well known reflex type as described in U.S. Pat. No. 3,672,281 entitled "Reflex Camera" by E. H. Land may be equally suitable for embodying the exposure control system of this invention. The following photographic cycle of operation is described in regard to a camera of the non-single lens reflex type wherein the viewfinder 95 does not have a through the lens viewing and focusing capability. The ambient photographic cycle is commenced with the depression of a start button (not shown) whereupon tension spring 88 operates to rotate walking beam 56 in a clockwise direction as viewed from the front of the exposure housing 16 thus moving shutter blade elements 38 and 40 in directions which operate to progressively enlarge the effective aperture over the light entering exposure opening 22. As is readily apparent, rotation of walking beam 56 effects simultaneous translation and rotation of shutter blade elements 38 and 40 about pivot pin 50. Simultaneously photocell sweep secondary apertures 46 and 48 define a corresponding progressively enlarging aperture opening over the photocell. When an appropriate amount of light is received to trigger the light sensitive control circuit, solenoid 78 is again energized to rapidly close blade elements 38 and 40 thereby terminating an exposure interval. The latter energization of solenoid 78 must continue until such a time as a latch 94 is moved into lateral engagement with an integral cam portion 96 of the walking beam 56 in a manner as is more fully described in an application for U.S. Patent, Ser. No. (Our Case No. 5198) by Andrew S. Ivester and David Van Allen, filed concurrently herewith in common assignment. In the preferred mode, the integral cam portion 96 defines an elongated planar cam surface the edge portion of which is shown at 98. With the ambient operation thus described, relative aperture as well as exposure interval are selectively weighted for any given level of scene brightness so as to optimize the selection of exposure interval and aperture. To trim this ambient performance of the exposure system, an optical trim wedge 100 having selectively variable transmissive properties therethrough, may be pivotally manipulated before the photocell. Adjustment of the position of trim wedge 100 is carried out by manually rotating the trim bezel 18 with respect to a trim mounting plate 102 which is fastened to the lens housing casting 14. The optical trim wedge 100 is disposed for rotation with respect to the trim mounting plate 102 by an interconnecting pivot pin 103. The optical wedge 100 additionally includes an arcuate toothed portion 110 which is drivingly engaged by a peripheral toothed portion 108 around the outside edge of the trim bezel 18, such that manual rotation of the trim bezel in turn operates to rotate the trim wedge 100 about pivot pin 103. Accordingly, manipulation of trim bezel 18 will selectively move the optical trim wedge 100 across the photocell to adjust the amount of light permitted to enter the light sensing control circuit through the photocell sweep secondary apertures 46 and 48. The variable light transmissive properties of the optical trim wedge are provided by a plurality of sections 112, each of which exhibits a different light transmissive property therethrough. A so called "follow focus" interceptor is provided for operation in conjunction with the focusing components of the camera during the flash mode of operation. The backward side of the lens mount assembly 28 drivingly connects to a radial face cam 168 in a manner such that the radial face cam moves in correspondence with manual adjustment of the focus bezel 20. As previously discussed, focus bezel 20 is rotatable to provide objective lens focusing and thus the rotational orientation of focusing bezel 20 continuously corresponds with the focus setting of the lens system. The integral cam portion 96 of walking beam 56 moves through a predetermined arcuate locus of travel as shutter blade elements 38 and 40 are driven either under the biasing spring 88 or from the plunger unit 80 of solenoid 78. For follow focus operation, the movement of walking beam 56 along its locus of travel establishing increasingly widening apertures is selectively arrested to establish a predetermined focus responsive apertural value. Motion arrest is provided by way of an interceptor crank assembly 114 which includes interalia, an interceptor pin 134 selectively positionable within the above noted locus of travel so as to contact the cam surface 98 of the integral cam portion 96 to halt the exposure mechanism as it moves under the bias of tension spring 88. Relative positioning of the interceptor crank assembly 114 within the locus of travel of integral cam portion 96 is provided by virtue of a pivotal connection between a crank arm plate 115 and an adjusting bar 118 at pivot point 116. The interceptor pin 134 is operatively associated with the crank arm plate 115 through an interceptor flapper linkage 120 which includes an elongated center portion 122 disposed for rotation relative to the crank arm plate 115 by a pair of integral pins 124 and 126 extending from the opposed ends of the elongated center portion 122. Pins 124 and 126 are respectively disposed for rotation with respect to the crank arm plate 115 by a pair of spaced apart bearing surfaces shown generally at 128 and 130 which extend from the crank arm plate 115. The interceptor flappage linkage 120 additionally includes an integral arm portion 132 extending downwardly from the elongated center portion 122 into fixed connection with the interceptor pin 134. As may be more readily seen by referring to FIG. 5, the interceptor pin 134 includes an arcuate edge surface 136 generated about a center axis coincident with a center axis or rotation pins 124 and 126 thus making the positioning of interceptor pin 134 within the locus of travel of walking beam 56 insensitive to the exact number of degrees thru which the flapper linkage 120 is rotated as will be subsequently described in greater detail. The interceptor flapper linkage 120 also includes an integral arm portion 140 extending upwardly from the elongated center portion 122 into engaging contact at point 146 with an integral arm portion 144 extending downwardly from a longitudinal drive link 148 of an actuating assembly shown generally at 142. The longitudinal drive link 148 is also disposed for rotation relative to the baseblock casting 12 by a pair of spaced apart integral pins 150, 152 extending from the longitudinal drive link in respective journalled relationship with a pair of appropriate bearing surfaces extending from the baseblock 12. The actuating assembly 142 additionally inclludes an integral arm portion 158 extending upwardly from the elongated drive link 148 and defining a tip portion 162 extending into the area of a linear flash array receiving socket 160. The interceptor crank assembly 114 is biased for rotation in a counterclockwise direction about the pivot point 116 by a tension spring 164, the moving end of which connects to an integral hook portion 166 which extends outwardly from the elongated center portion 122 of the interceptor flapper linkage 120. The non-moving end of the tension spring 164 is grounded with respect to the baseblock casting 12. Tension spring 164 also sumultaneously operates to bias flapper linkage 120 to rotate interceptor pin 134 out of the locus of travel of walking beam 56 while at the same time biasing the flapper arm portion 140 into continuous engagement with the actuating assembly 142 so as to maintain the tip portion 162 thereof within the socket 160. The lens mount assembly 28 drivingly connects to a radial face cam 168 defining cam surface 169 concentric with the objective lens 24 optical axis for movement in correspondence with the focus bezel 20. There is additionally included a peripheral flange 171 extending radially outward of the cam surface 169 to provide a light and dust seal. The radial face cam 168 drivingly engages a rigid adder link 172 at an integral cam follower portion 176 thereof intermediate the ends of the adder link 172. One distal end of the adder link 172 pivotally connects to the interceptor crank assembly 114 at a pivot point 174. The opposite end of the adder link 172 defines a cam portion 178 disposed for simultaneous translation and rotation about a driver pin 180 which is operatively connected to the trim bezel 18 for movement in correspondence therewith in the following manner. As is now readily apparent, tension spring 164 also serves to bias crank arm plate 115 for counter-clockwise rotation about pivot point 116 in this manner facilitating continuous engagement between the follower portion 176 of adder link 172 and the cam 168. Manual adjustment of trim bezel 18 operates through the meshed teeth 108, 110 to rotate the optical trim wedge 100 about its point of pivotal connection at 103 to the trim mounting plate 102 simultaneously rotating drive pin 180 which is in fixed connection thereto. Thus manual adjustment of the trim bezel 20 operates to simultaneously vary light transmission to the photocell while at the same time rotating drive pin 180 about the trim wedge pivot point at 103. The cam portion 108 may be maintained in continuous driving engagement with pin 180 through overlying link portions 182 which integrally connect to a second pin 183 extending from the optical trim wedge 100. Actuation of the interceptor flapper linkage 120 during the flash mode of operation is provided as follows. Insertion of a conventional linear flash array unit (not shown) into its associated receiving socket 160 operates to engage the tip portion 162 of the actuating assembly 142 so as to rotate the upwardly extending arm portion 158 thereof about the pivot pins 150, 152 and inwardly from the plane of the drawing as illustrated in FIGS. 2 and 3. Rotation of the upwardly extending arm portion 158 in this manner in turn operates to rotate the downwardly extending arm portion 144 outwardly from the plane of the drawing as shown in FIGS. 2 and 3 so as to engage the upwardly extending arm portion 140 of the interceptor flapper linkage 120. The interceptor flapper linkage 120 is thus rotated about the pivot pins 124, 126 against the bias of tension spring 164 such that the interceptor pin 134 and its associated arm portion 132 rotate inwardly from the plane of the drawing as shown in FIGS. 2 and 3 into the locus of travel of the walking beam 56 and its associated integral cam 96 as best shown in FIG. 5. As previously discussed, since the arcuate edge surface 136 of the interceptor pin 134 is generated about the same center axis about which the flapper linkage rotates, the precise point of walking beam interception is therefore determined irrespective of the exact number of degrees through which the interceptor flapper linkage 120 rotates upon insertion of a linear flash array. As it now apparent, it is not necessary that the tip portion 162 of the actuating assembly 142 be always rotated through a precise number of degrees in order to locate the interceptor pin 134 at a precise point of interception. Thus each linear flash array unit need not be exactly dimensioned in order to precisely locate the interceptor pin. During the flash mode of operation the interceptor crank assembly 114 is actuated in the aforementioned manner to move the interceptor pin 134 into the locus of travel of the walking beam 56 and its associated integral cam 96. Once actuated the interceptor pin 134 is thereafter in position to intercept the cam surface 98 of the walking beam 56 during an exposure interval, which point of interception coincides with a precise aperture value as is determined by the cooperative relation of the aperture blade elements 38 and 40 together with their associated light admitting primary apertures 42 and 44. In this manner the camera may be adjusted in accordance with the levels of artificial illumination anticipated at the scene to be photographed. Thus the mechanical and geometric relationship between the radial face cam 168, trim link 172, interceptor crank assembly 114, and interceptor cam 134 are based upon an application and evaluation of the inverse square law of light energy propagation where the light energy available from a given source is considered to vary inversely with the square of the distance from that source. An analog representation of the light source to subject distance is provided by the radial face cam 168 which moves in correspondence with the focusing bezel 20 to drive the trim link 172 about the drive pin 180 so as to in turn rotate the interceptor crank assembly 114 about the fixed pivot point 116. As is readily apparent, the interceptor pin 134 is also rotated in concert with the interceptor crank assembly 114 so as to vary its location along the walking beam 56 and integral cam 96 locus of travel in accordance with the inverse square law of light energy propagation. In other words, the maximum aperture to which the aperture blade elements 38, 40 may open is directly determined by the focusing system of the camera in conformance with the inverse square law of light energy propagation. In the orientation corresponding to an F/8 stop, interceptor pin 134 is positioned to establish a fully open aperture. Other positions of interceptor pin 134 serving to arrest walking beam cam 98 to establish progressively diminishing apertures up to about F/107 are shown at 134' thus defining positions at which the walking beam cam 96 is intercepted for the diminishing aperture sizes. The locus of travel of interceptor pin 134 as illustrated by the series of circles at 134' describes an arcuate segment of a circle the center of which coincides with the center of rotation of the interceptor crank assembly 114 at pivot point 116. Relative positions of follower portion 176 of link 172 for various adjustments of focus bezel 20 are shown at 176'. These serially disposed positions of integral cam follower 176 follow the same F-number sequance in correspondence with the interceptor pin 134 as well as walking beam cam 96. The radial face cam 168 may also be configured to provide a dwell portion during which a continuous maximum aperture is established. This portion of the focusing range represents subject distances from infinity to the effective output range of the source of artificial illumination being used. As ths effective range is reached, the cam 168 is configured to commence simultaneous translation and rotation of adder link 172 about pivot pin 180 in a manner causing interceptor pin 134 to rotate about its respective pivot point at 116 so as to define progressively increasing numerical values of aperture. The trim bezel 18 may also be manually rotated to provide trim adjustment in the following manner. Manual rotation of the trim bezel 18 is imparted to the optical trim wedge 100 by way of the meshed teeth 108, 110. Rotation of the trim wedge 100, in turn, operates to rotate its associated drive pin 180 about the point of pivotal connection at 103 between the trim wedge 100 and mounting plate 102. The rotation of drive pin 180 in turn operates to rotate the adder link 172 about its follower portion 176 so so to pivot the interceptor crank assembly 114 about its associated point of pivot at 116. In this manner, the interceptor pin 134 may be rotated through its arcuate path in concert with rotation of the trim bezel 18. Accordingly, manual rotation of trim bezel 18 causes the position of interceptor pin 134 to be selectively advanced or retarded in its aperture defining position therewithin and the interceptor assembly 114 can thus be adjusted or trimmed by any select exposure value through a simple manipulation of the trim bezel 18. The trim bezel 18 may be adjusted through either a clockwise or counterclockwise rotation thereof from an intermediate neutral position as shown in FIG. 3. As is readily apparent from FIG. 3, full counterclockwise rotation of the trim wedge 100 operates to permit the adder link 172 to be rotated by the biasing spring 164 in a clockwise direction about the follower portion 176, thus rotating the interceptor crank assembly 114 and its associated interceptor pin 134 in a counterclockwise direction about the pivot point 116 to define a progressively increasing aperture area. Conversely, clockwise rotation of trim wedge 100 about its associated pivot point 103 operates to rotate adder link 172 about its follower portion 176 and against the bias of spring 164 in turn rotating interceptor crank assembly 114 and its associated interceptor pin 134 in a clockwise direction about pivot point 116 to define progressively decreasing aperture areas. As is now readily apparent, an important feature of this adjustment is that a full clockwise or counterclockwise rotation of the trim bezel 18 from its neutral position will always operate to impart a substantially corresponding change in the degrees of rotation of the interceptor pin 134 about the pivot point 116 regardless of the position of focus bezel 20 and its associated radial face cam 168. A predetermined number of degrees rotation of the interceptor pin 134 will in turn correspond to a predetermined number of F/stop changes in the aperture value defined by the scene light admitting primary apertures 42 and 44 regardless of the initial position of the interceptor pin 134. Therefore, the trim adjustment remains substantially uniform regardless of focus and cam 168 adjustment. In other words, rotation of the trim bezel 18 about a preselected number of degrees in either direction from the neutral position will be reflected by a predetermined number of degrees rotation of the interceptor pin 134 about the pivot point 116 thus changing the aperture value by a predetermined number of F/stops regardless of the position of the radial face cam 168 and its associated focus bezel 20. In a preferred mode of operation, it is desirable that a full adjustment of the trim bezel 18 from the neutral position correspond to a one and one half F/stop change in the aperture value. The above described linear correspondence between the trim adjustment and its associated change in aperture value is made possible by the following mechanical and geometric interrelationship of the exposure system components as best seen in FIG. 3. With the radial face cam 168 adjusted to its intermediate position corresponding to an aperture value halfway between the minimum and maximum aperture values and with the trim bezel 18 adjusted to its neutral position, there can be seen a straight line path A in direct intersection with the pivot points 116, 174, 180 and 103 as well as the interceptor pin 134 and the follower portion 176. The location for the interceptor pin 134 corresponding to the minimal apertural value is next determined by tracing the arcuate locus of travel for the interceptor pin 134 as shown by the phantom line B which is thereafter tangentially intersected by a straight line C which also intersects the center axis D of walking beam 56 rotation. At this point of tangential intersection as shown at E, there is determined the location of the interceptor pin 134 corresponding to the minimum aperture F/stop value. The number of degrees of rotation through which the interceptor pin 134 progresses between the position corresponding to the intermediate aperture F/stop value and the position at E corresponding to the minimum aperture F/stop value may thereafter be determined, and a like number of degrees rotation of the interceptor pin 134 in the opposing direction from the intermediate position will determine the position of the interceptor pin corresponding to its maximum aperture F/stop value. The geometrical relationships herein described between the various exposure mechanism components are believed to make possible the substantially uniform relationship whereby the aperture value changes by a predetermined amount in correspondence with a predetermined change in trim adjustment regardless of exposure setting. In order to consistently achieve the aforementioned geometrical relationships in a mass produced commercial camera, the cumulative effect of dimensional variations in the individual components must somehow be negated. For this purpose, there is provided the adjusting bar 118 which may be selectively rotated about a fixed pivot point 184 connecting to the base block casting 12. In this manner, rotation of adjusting bar 118 operates to rotate pivot point 116 about pivot point 184 so as to achieve the aforementioned precise alignment as required for uniform correspondence between the change in aperture value and the change in trim adjustment. The outside end of the adjusting bar 118 may include a detent 188 for selective engagement with a corrugated type scale 186 which defines a plurality of discrete settings with regard to the baseblock casting 12. It will now be appreciated that adjustment of trim bezel 18 and its associated trim wedge 100 also serves to selectively position a plurality of varying light transmissive sections 112 over the light sensing photocell of the light detecting station 49. Therefore as a consequence, any exposure value inserted as a trim from trim bezel 18 is simultaneously transmitted to the interceptor crank assembly 114 as well as into the light detecting station 49. This arrangement is advantageous in systems of the so-called hybrid type as discloded in an application for U.S. Patent entitled "Automatic Exposure Control System" by G. D. Whiteside and B. K. Johnson, filed Aug. 5, 1974 and assigned in common herewith, where follow focus and light detecting means are used in cooperation with each other during the flashmode of operation. Since certain changes may be made in the above described system and apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the description thereof or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

An improved exposure control system featuring a follow-focus mechanism wherein the geometrical relationship of the mechanical components are determined in a select manner to provide uniform adjustment of the exposure aperture through a trim mechanism irrespective of the actual focus setting. The follow focus additionally may be precisely calibrated despite the cumulative effect attributable to the dimensional variations of the individual components albeit such variations remain within prescribed tolerances.

CLAIM OF PRIORITY This application claims priority under 35 USC §119(e)(1) to U.S. Provisional Application Ser. No. 61/907,037, filed on Nov. 21, 2013, the entire contents of which are hereby incorporated by reference. TECHNICAL FIELD The present disclosure relates to software, computer systems, and computer-implemented methods for visualizing data exchanged using the Open Data Protocol (OData). BACKGROUND Open Data Protocol (OData) is a standardized protocol for creating and consuming data application programming interfaces (APIs). OData can be implemented as a protocol that can expose full-featured data APIs using core protocols like Hypertext Transfer Protocol (HTTP) and Representational State Transfer (REST) architecture. OData also implements the Atom Publishing Protocol (AtomPub) for creating and updating resources, e.g., resources available over networks such as the Internet, and JavaScript Object Notation (JSON), a text-based open standard designed for human-readable data interchange. OData can be implemented to expose and access information from a variety of sources, e.g., relational databases, file systems, content management systems, resources provided on websites, and other sources. A response for an OData request can include metadata associated with the data source presented, e.g., an Extensible Markup Language (XML) document. Sometimes, parsing the structure and arrangement of data in the XML document can be difficult. SUMMARY This disclosure describes computer-implemented methods, computer-readable media and computer systems for interacting with data exchanged using OData. In general, one innovative aspect of the subject matter described here can be implemented as a method performed by data processing apparatus. At a client computer system, multiple resources are received. The resources are defined according to a first data structure. The resources are received from a server computer system to a data network in response to an Open Data Protocol (OData) request for the multiple resources. A resource of the multiple resources is associated with a boundary that specifies resource operations performable on the resource. From the multiple resources, the resource associated with the boundary and the resource operations that are performable on the resource are identified. The identified resource is translated from the first data structure to a second data structure different from the first data structure. In the second data structure, the identified resource is editable to perform the resource operations on the identified resource. In a user interface, the identified resource is displayed according to the second data structure. The resource operations that are performable on the identified resource are also displayed. This, and other aspects, can include one or more of the following features. Each of the multiple resources is a network-accessible data object or service identified by a respective identifier. Each of the multiple resources is associated with respective metadata which is received with the multiple resources. The resource operations performable on the resource can include at least one of a create operation, a retrieve operation, and update operation, or delete operation. Displaying the identified resource and the resource operations can include displaying, in the user interface, a table including a crow and multiple columns. The identified resource can be displayed in a first column of the row. The resource operations performable on the resource can be displayed in respective columns of the row. The multiple resources can be associated multiple properties. The multiple properties are filterable by multiple filters. The multiple filters by which the multiple properties are filterable can be identified. The multiple filters can be displayed in the user interface. Input to filter the multiple properties by a specified filter can be received. It can be determined whether the specified filter is included in the multiple filters. The multiple properties can be filtered by the specified filter in response to determining that the specified filter is included in the multiple filters. The boundary can represent mandatory parameters that must be provided when performing the resource operations on the identified resource. The mandatory parameters can be displayed in the user interface. Input to perform resource operations on the identified resource can be received. The input can include a parameter. The resource operations based on the parameter can be performed in response to determining that the parameter included in the input is one of the mandatory parameters that must be provided when performing the resource operations on the identified resource. A notification that the received parameter is not one of the mandatory parameters can be displayed in the user interface in response to determining that the parameter included in the input is not one of the mandatory parameters that must be provided when performing the resource operations on the identified resource. The identified resource can be a first resource. An association defining a relationship between the first resource and a second resource can be identified in response to the OData request for the multiple resources. The relationship can define a referential constraint that relates the first resource to the second resource. The identified relationship can be displayed in the user interface. Receiving the multiple resources defined according to the first data structure can include displaying, in the user interface, multiple services. Each service can be associated with a respective multiple resources. The multiple services can include a specified resource associated with the received multiple resources. A selection of the specified resource can be received in the user interface. Displaying the multiple services in the user interface can include receiving, in the user interface, authentication information that authenticates a request or off the multiple resources and an identifier identifying a computer-readable medium storing the multiple resources. It can be determined that the requester is authorized to access resources stored on the computer-readable medium based on the authentication information. Another innovative aspect of the subject matter described here can be implemented as a computer-readable medium storing instructions executable by data processing apparatus to perform operations described here. A further innovative aspect of the subject matter described here can be implemented as a system that includes data processing apparatus and a computer-readable medium storing instructions executable by the data processing apparatus to perform the operations described here. While generally described as computer-implemented software embodied on tangible media that processes and transforms the respective data, some or all of the aspects may be computer-implemented methods or further included in respective systems or other devices for performing this described functionality. The details of these and other aspects and implementations of the present disclosure are set forth in the accompanying drawings and the description below. Other features and advantages of the disclosure will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an example client-server network exchanging resources by implementing the Open Data Protocol (OData). FIGS. 2A-2N are schematic diagrams of example user interfaces that present resources obtained by implementing OData. FIGS. 3A-3F are flowcharts of an example process for presenting resources obtained by implementing OData. Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION This disclosure relates to interacting with resources exchanged using OData (OData feeds). OData is a standardization protocol implemented to exchange resources over a data network, e.g., the Internet. The data network includes server computer systems that host the resources and client computer systems that can interact with the server computer systems to manipulate or update the resources. An end point on a server computer system is called a service. OData is a HTTP-based protocol designed with a REST architecture. To query the resources using OData, a Uniform Resource Indicator (URI) is formed. The URI includes appropriate headers, e.g., HTTP headers such as GET, PATCH, POST, DELETE, and other headers. The resources are sent from and to the server computer systems in notations such as ATOM or JSON. Because the protocol is HTTP-based, one or more of several programming languages with an HTTP stack can be used to interact with the resources. Many client side libraries, e.g., .NET, iOS, JavaScript, Java, Ruby, Android, and other client side libraries, have been created which parse the ATOM or JSON payloads into objects to simplify interaction with the resources. Similarly, many server side libraries, e.g., .NET, Java, Azure, MySQL, PHP, Files, SQL Server, and other server side libraries, have been created to parse/generate payloads and to provide easy interaction with back ends, e.g., databases, files and other back ends, in which the resources are stored. Because OData is HTTP based, the server and client sides can be implemented using different libraries. For example, the server can expose the resources via OData can be consumed by client side library subject, in some cases, to authentication for data access. As stated above, an end point on a server computer system that hosts resources is called a service. OData feeds can sometimes be received as Atom Service Documents from the root of a service. Such documents include titles and URIs for each of the service's feeds. As such, the service document may not include information about the shape of the entries exposed by the feed or about relationships between feeds. OData feeds often include metadata in a particular data structure, e.g., a .EDMX file which is an XML file that defines a conceptual model. The metadata includes a description of the resources, resource types, properties, relationships exposed by the service, and other description. Client computer systems that implement OData client libraries can leverage the metadata to drive the generation of client-side classes to represent server types and aid programmability. In some instances, the XML file which includes the metadata, when displayed in a user interface, can include too complicated to understand the structure of the resources and to manually bind the resource elements to the user interface. Doing so can involve significant effort on the part of a user of a client computer system (e.g., a developer of a computer software application), be error prone leading, and result in duplication of efforts. This disclosure describes a user interface tool to present and browse OData feeds that can be implemented on a computer system, e.g., a client computer system, as a computer software application. For example, the user interface tool can be implemented as a plug-in to another computer software application executable on the computer system. Presenting the OData feed in a user interface provided by executing the user interface tool can allow a user (e.g., the developer) to visualize the OData feed structure and understand the semantics of the resources included in the OData feed. The user interface tool can be implemented to provide an out-of-box user interface using which a developer can view and modify resources. Using the user interface, the developer can browse into related entity sets (e.g., associations), set filters on properties, and perform other operations. The user interface tool can be implemented to create, update, and analyze the resources that are local to the client computer system. Using the user interface, the developer can also be informed about the availability of the possible list of values for the service properties that can be used while creating or updating the resources through the OData feeds. The user interface tool can decrease the developer's effort to understand the OData structure and its associated entities. In this manner, the user interface tool can be implemented to enhance the developer's user experience and ability to interact with resources presented to the user as OData feeds. FIG. 1 is a schematic diagram showing an example client-server network 100 exchanging resources by implementing OData protocol. The client-server network 100 includes multiple client computer systems on the client side (e.g., a first client computer system 102 a , a second client computer system 102 b , a third client computer system 102 c , and other client computer systems). A client computer system can include a data processing apparatus connected to input devices and output devices. For example, a first processor 104 a of the first client computer system 102 a can be connected to a first input device 108 a and a first output device 106 a . Similarly, a second processor 104 b and a third processor 104 c of the second client computer system 102 b and the third client computer system 102 c , respectively, can be connected to a second input device 108 b and a third input device 108 c , respectively, and a second output device 106 b and a third output device 106 c , respectively. A client computer system can be, e.g., a desktop computer, a laptop computer, a tablet computer, a smart phone, a personal digital assistant (PDA) or other client computer system. Input devices can include a keyboard, a mouse, a stylus, a touchscreen, an audio input, or other input devices. Output devices can include a monitor, a touchscreen, printing systems, audio systems or other output devices. A client computer system can include a computer-readable medium (not shown) that can store computer instructions executable by the data processing apparatus to perform operations. For example, the computer instructions can be implemented by the data processing apparatus as one or more computer software applications such as client-side libraries described above. In some implementations, a developer of a computer software application can interact with OData feeds, i.e., resources exchanged over the network 100 by implementing the OData protocol, by executing one or more client-side libraries on a client computer system. The client-server network 100 includes multiple server computer systems on the server side (e.g., server computer systems 114 a , 114 b , 114 c , 114 d , 114 e , 114 f , and other server computer systems) connected to the client computer systems over one or more networks (e.g., a first network 110 , a second network 112 , or other networks) such as the Internet. Each server computer system can store resources to be exchanged with the client computer systems by implementing the OData protocol. In addition, each server computer system can include a computer-readable medium to store computer instructions executable by data processing apparatus to perform operations. For example, each server computer system can implement one or more server-side libraries such as those discussed above to receive requests for resources from one or more client computer systems and to provide the resources in response to receiving the requests. In some implementations, a user of a client computer system (e.g., the first client computer system 102 a ) can be a developer of a computer software application. Using the first client computer system 102 a , the developer can request resources stored on a server computer system (e.g., the first server computer system 114 a ). Operations implemented by the first client computer system 102 a , the first server computer system 114 a , and the client-server network 100 implementing the OData protocol are described below with reference to FIGS. 2A-2N , which are schematic diagrams of example user interfaces that present resources obtained by implementing OData and 3 A- 3 F, which are flowcharts of an example process 300 for presenting resources obtained by implementing OData. The process 300 can be implemented as a computer software application stored on a computer-readable medium as computer instructions and executable by data processing apparatus included in a client computer system. In some implementations, the first client computer system 102 a can implement the process 300 as an OData application plug-in to another computer software application executing on the first client computer system 102 a . For example, the computer software application executing on the first client computer system 102 a can be an application that a developer can use to design/develop computer software applications. At 302 , input can be received from a developer to execute the OData application. For example, the first client computer system 102 a can display a user interface 202 ( FIG. 2A ) in the first output device 106 a by executing the applications design/development software. The user interface 202 can include a selectable object 204 that can identify the OData application executable by the first client computer system 102 a . Using an input device 108 a , the developer can select the selectable object 204 , which can represent the input to execute the OData application. At 304 , a developer authentication information can be presented to the developer. For example, in response to receiving a selection of the selectable object 204 , the first client computer system 102 a can display user interface 206 ( FIG. 2B ) requesting the developer's authentication information (e.g., log-in, password, or other authentication information). In some implementations, the first client computer system 102 a can additionally request one or more identifiers identifying the server computer system that the developer is attempting to access. The server computer system can include a computer-readable medium storing resources that the developer can use to develop a computer software application. For example, the first client computer system 102 a can display objects into which the developer can input an Internet Protocol (IP) address of the server computer system, a port or other identifier that identifies the server computer system. At 306 , the first client computer system 102 a can receive the developer authentication information and the identifier identifying the server computer system, e.g., that the developer provides through the user interface 206 . The input represents the developer's request to access services stored on the server computer system identified by the identifier. The first client computer system 102 a can identify the server computer system (e.g., the first server computer system 114 a ), and transmit the request for the services to the first server computer system 114 a . The first server computer system 114 a can store multiple services, each being associated with multiple resources. The developer's authentication information can permit the developer to access one or more or all of the services stored on the first server computer system 114 a . The first server computer system 114 a can identify the services that the developer is permitted to access, and transmit identifiers referencing the permissible services to the first client computer system 102 a. At 308 , the services received from the server computer system can be presented. For example, the first client computer system 102 a can receive the identifiers referencing the services transmitted by the first server computer system 114 a , and display the identifiers (e.g., a first identifier 208 a , a second identifier 208 b , a third identifier 208 c , a fourth identifier 208 d , and other identifiers) in the user interface 206 ( FIG. 2C ). At 310 , a selection of a service can be received. For example, the developer can select an identifier referencing a service (e.g., the first identifier 208 a ) in the user interface 206 . The developer can then select a selectable object 210 . At 312 , resources associated with the selected service can be requested. For example, in response to the developer selecting the first identifier 208 a and the selectable object 210 , the first client computer system 102 a can transmit the selected identifier to the first server computer system 114 a . The first server computer system 114 a can receive the selection and identify the associated resources. At 314 , the resources associated with the request are received according to a first data structure. For example, the first client computer system 102 a receives multiple resources that are associated with the selected service. The resources can include, e.g., network-accessible data object identified by a respective identifier (e.g., URI). Each of the multiple resources is also associated with respective metadata which is received by the first client computer system 102 a with the multiple resources. In some implementations, the first data structure in which the multiple resources are received is an XML structure. For example, the resources and the associated metadata and semantics can be received as a .EDMX document. The user interface tool described here can translate the .EDMX document into a second structure that can present the resources and the metadata textual and visual manner that is easier for the developer to view relative to the XML structure. At 316 , resources that are associated with boundaries and resource operations performable on the resources are identified. Each of the multiple resources is also associated with a respective boundary that specifies resource operations performable on the resource. The resource operations can include one or more of a create operation, a retrieve operation, an update operation, or a delete operation. In some implementations, one or more or all of the resources received in response to the request can be associated with respective boundaries that specify respective operations performable on the resource. A boundary defines the capabilities of the resources in the OData feed. For example, a boundary for a resource defines that the resource can be annotated as creatable or updatable (i.e., the resources cannot be created by the developer but can be updated). The respective operations can be associated with the resources as resource metadata or resource semantics (or both) The first client computer system 102 a can decipher the semantics associated with the resources, and render the user interface accordingly thereby allowing the developer know that certain resources exposed through the OData feed can/cannot be created. The first client computer system 102 a can identify the resources associated with the boundaries and the respective resource operations. At 318 , the resources can be translated from the first data structure into the second data structure. In some implementations, the first client computer system 102 a can translate one or more or all of the received resources from the first data structure to the second data structure. In the second data structure, the resources are editable to perform the resource operations specified by the boundaries for the resources. The first client computer system 102 a (e.g., the user interface tool executing on the first client computer system 102 a ) can translate the multiple resources from the XML structure to a tabular structure shown, for example, in FIG. 2D . At 320 , the resources can be displayed according to the second data structure and the resource operations performable on the identified resource. For example, the first client computer system 102 a can display each resource in a table including multiple rows and tables ( FIG. 2D ). Each row in the table can represent a respective resource (e.g., a first resource 216 a , a second resource 216 b , a third resource 216 c , a fourth resource 216 d ). At 340 ( FIG. 3E ), the first client computer system 102 a can display multiple rows and columns. At 342 ( FIG. 3E ), the first client computer system 102 a can display an identifier (e.g., a name or a URI or other identifier) referencing the resource in a first column of a row. At 344 ( FIG. 3E ), the first client computer system 102 a can display operations formable on the resource (e.g., a create operation 214 a , an update operation 214 b , a delete operation 214 c , a query operation 214 d ) in other respective columns in the row. As shown in FIG. 2D , the resource operations performable on the different resources can be different. For example, the resource operations performable on the first resource 216 a can include all of the create operation 214 a , the update operation 214 b , the delete operation 214 c , and the delete operation 214 d . In contrast, the resource operations performable on the second resource 216 b can include only the query operation 214 d . As shown in FIG. 2D , the first client computer system 102 a can display a notification (e.g., a check mark or other notification) in one or more columns in a row to identify, to the developer, the resource operations that are performable on a resource identified in the row. One or more or all of the resources displayed in the user interface 206 can include properties, which the first client computer system 102 a can display in a user interface portion 218 of the user interface 212 . The properties for a resource can include, e.g., one or more of a “Name” (e.g., “Street” 220 a , “GenderCode” 220 b , “FaxSequenceNumber,” “MiddleName,” “RegionCode,” “BirthDate,” “LastName” 220 c , “BuildingID” 220 d ), a “Label” (e.g., a description of “Name”), a “Type” (e.g., a string, a number, a date/time), and additional semantics. The semantics can be leveraged by the developer to render the resources according to the boundaries defined, e.g., by a resource administrator for the resources. In some implementations, the properties with which the resources are associated can be filtered by multiple filters. The first server computer system 114 a can associate multiple filters with the resources. Sometimes, a developer can filter the resources by all of the multiple filters. Sometimes, semantics associated with the resources can specify that the multiple resources can be filtered by less than all of the multiple filters. The first client computer system 102 a can identify the filters by which the resources can be filtered based on the semantics, and display the filters in the user interface portion 224 ( FIG. 2D ). In some implementations, the first client computer system 102 a can display only those properties for filtering which have been appropriately marked as being filterable, e.g., by the service developer. The first client computer system 102 a can display properties associated with the resources, e.g., restrictions on resource operations that can be performed on the resources, in a user interface portion 224 of the user interface portion 223 ( FIG. 2D ). Such properties can be received with the resources, e.g., as metadata or semantics (or both), from the first server computer system 114 a . Semantics information can also include, e.g., value help available for a particular property of a resource. For example, a value help of a country property can be a persisted code, e.g., 2-digit country code). The first client computer system 102 a can identify the properties, translate the information into a format that can be visualized more easily than an XML format, and present the translated information in the user interface portion 224 . For example, the first client computer system 102 a can translate the 2-digit country code into a textual property value, such as the corresponding country name, and display the country name, instead of the country code, in the user interface. Other examples of translating value help numerical values into textual values include translations of GenderCode to male/female, marital code to single/married/divorced, to name a few. In some implementations, such properties can also be annotated through semantic information in the OData feed. The first client computer system 102 a can understand the annotations and inform the developer about the availability of the value help for a property, and, in the auto-generated create/update form, provide visualization to the value help fields. Doing so can allow the developer to understand the available value help and the corresponding structure, e.g., CountryCode/name for country, RegionCode/name for region, and other structures. As shown in FIG. 3B , at 322 , the first client computer system 102 a can display the semantics associated with the resources in the user interface portions 226 , 228 , 230 or combinations of them ( FIG. 2E ). The first client computer system 102 a can identify an association defining a relationship between two resources (e.g., a first resource and a second resource) in response to the OData request for the multiple resources. The relationship can define a referential constraint that relates the first resource to the second resource. The first client computer system 102 a can display the identified relationship in the user interface portions 223 or 226 or both ( FIG. 2F ). For example, as shown in FIG. 3C , at 324 , the first client computer system 102 a can display associations associated with one or more of the resources. At 326 , the first client computer system 102 a can receive input (e.g., a selection in the user interface) to display additional information describing the associations. At 328 , the first client computer system 102 a can display the additional information in the user interface. As shown in FIG. 3D , at 330 , the first client computer system 102 a can receive a request for sample data associated with one or more of the resources. At 332 , the first client computer system 102 a can display the sample data based on restrictions associated with the sample data, e.g., in user interface 232 ( FIG. 2G ). In some implementations, the developer can select one or more of the resources shown in the user interface 232 from the OData feed to understand the data. At 334 , the first client computer system 102 a can receive a filter to be applied to the sample data. For example, the first client computer system 102 a can receive input to filter multiple properties associated with a resource by a specified filter. To do so, the developer can select filters displayed in the user interface portion 238 . As shown in FIG. 2H , from a drop down list, the user can select filters, provide filter parameters (e.g., in the textbox 236 ), and apply the filter, e.g., by selecting the selectable object 240 . At 336 , the first client computer system 102 a can determine that the specified filter can be applied. To do so, for example, the first client computer system 102 a can determine whether the specified filter is included in the multiple filters by which the multiple properties can be filtered. Upon determining that the specified filter is included in the multiple filters, at 338 , the first client computer system 102 a can apply the filter. For example, the first client computer system 102 a can filter the multiple properties by the specified filter. In some implementations, the first client computer system 102 a can display associated entities in the user interface 234 . The developer can select and view one of the entities, e.g., by selecting the selectable object 242 ( FIG. 2H ). In response to the selection of the selectable object 242 , the first client computer system 102 a can display the related entity in user interface 244 ( FIG. 2I ). For example, in the user interface 244 , the first client computer system 102 a can display information such as relationship key, validity, scheme ID, and other information. As described above, the resources are associated with respective boundaries which, among other things, represent mandatory parameters that must be provided when performing the resource operations on the respective resources. As shown in FIG. 3F , at 346 , the first client computer system 102 a can display the mandatory parameters. For example, in the user interface 246 ( FIG. 2J ), the first client computer system 102 a displays multiple parameters (e.g., “Telephone Extension,” “Salutation,” “Fax Country Code,” and other parameters). In the user interface 246 , the first client computer system 102 a displays a notification (e.g., an asterisk, a check mark, or other notification) adjacent to certain parameters (e.g., “Telephone Sequence Number,” “Category,” “Preferred Communication Type,” and other certain parameters) indicating that the notified parameters are mandatory. At 348 , the first client computer system 102 a can receive an input including a parameter. At 350 , the first client computer system 102 a can perform a resource operation in response to determining that the parameter included in the input is one of the mandatory parameters. For example, if the input includes input to update a parameter that cannot be updated, then the first client computer system 102 a may not perform the resource operation and, instead, can display a notification that the developer is not permitted to perform the requested resource operation. In some implementations, as shown in FIG. 2K , the first client computer system 102 a can display, in user interface 248 , possible entry fields based on the association of the resources. For example, if the entry fields contain fixed values that the computer system 102 a can select from then the same can displayed in a value help picker as the possible values for the selected entry fields. This helps the developer in identifying the entry fields with possible value help options. A closer view of the user interface 246 ( FIG. 2L ) reveals different user interface representations for “Gender” 250 , “Fax Sequence Number” 252 , and “Middle Name” 254 . The user interface representation for the entry fields displayed in the computer system 102 a can be based on the entry field's semantics and attributes. For example the entry field for “Middle Name” 252 can be treated as simple editable text field; the entry field for the “Gender” 250 can be editable text field with options provided to the user for selecting the value from the possible value list as a value help picker. This helps the developer in designing a graphical interface on the computer system 102 a based on the attributes of the entry fields. In some implementations, the first client computer system 102 a can be configured to determine that the parameter to be provided is a date, and, in response, to display a calendar user interface 256 ( FIG. 2M ) from which the developer can select the date. The first client computer system 102 a can enter the selected date in an appropriate text box ( FIG. 2N ). In this manner, the user interface tool executed by the first client computer system 102 a can parse the XML document that includes the resources, metadata, semantics, filters, and other properties, that is received from the first server computer system 114 a into a format that is visually and textually easier for a developer to view and interact. In some implementations, the first client computer system 102 a can handle semantic information defined as having “thing” attributes. For example, some of the resources exposed in the OData feed can be mapped as “thing” type, e.g., “Contact” or “Calendar” or “Task” or other “thing” type. The attributes of the contact resources can be described using certain standards, e.g., RFC standards for vCard. The first client computer system 102 a can interpret attributes present in the OData feeds to inform the developer of the presence of these entities in a textual manner. Thus, the user interface tool executed by the first client computer system 102 a can suggest a mapping between semantic information and other items. Similar to the first client computer system 102 a , one or more of the other client computer systems can similarly execute respective user interface tools described above to present OData feeds received from one or more of the other server computer systems. In this manner, multiple client computer systems can, in parallel, interact with OData feeds received from multiple server computer systems through the OData protocol. Implementations of the subject matter and the operations described in this disclosure can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this disclosure and their structural equivalents, or in combinations of one or more of them. Implementations of the subject matter described in this disclosure can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on computer storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively or in addition, the program instructions can be encoded on an artificially-generated propagated signal, for example, a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium, for example, the computer-readable medium, can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially-generated propagated signal. The computer storage medium can also be, or be included in, one or more separate physical and/or non-transitory components or media (for example, multiple CDs, disks, or other storage devices). In some implementations, the operations described in this disclosure can be implemented as a hosted service provided on a server in a cloud computing network. For example, the computer-readable storage media can be logically grouped and accessible within a cloud computing network. Servers within the cloud computing network can include a cloud computing platform for providing cloud-based services. The terms “cloud,” “cloud computing,” and “cloud-based” may be used interchangeably as appropriate without departing from the scope of this disclosure. Cloud-based services can be hosted services that are provided by servers and delivered across a network to a client platform to enhance, supplement, or replace applications executed locally on a client computer. The system can use cloud-based services to quickly receive software upgrades, applications, and other resources that would otherwise require a lengthy period of time before the resources can be delivered to the system. The operations described in this disclosure can be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources. The term “data processing apparatus” encompasses all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations, of the foregoing. The apparatus can include special purpose logic circuitry, for example, an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). The apparatus can also include, in addition to hardware, code that creates an execution environment for the computer program in question, for example, code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them. The apparatus and execution environment can realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures. A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (for example, one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (for example, files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. The processes and logic flows described in this disclosure can be performed by one or more programmable processors executing one or more computer programs to perform actions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, for example, an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, for example, magnetic, magneto-optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, for example, a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (for example, a universal serial bus (USB) flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, for example, EPROM, EEPROM, and flash memory devices; magnetic disks, for example, internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. To provide for interaction with a user, implementations of the subject matter described in this disclosure can be implemented on a computer having a display device, for example, a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user, and a keyboard, a pointing device, for example, a mouse or a trackball, or a microphone and speaker (or combinations of them) by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, for example, visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user; for example, by sending web pages to a web browser on a user's client device in response to requests received from the web browser. Implementations of the subject matter described in this disclosure can be implemented in a computing system that includes a back-end component, for example, as a data server, or that includes a middleware component, for example, an application server, or that includes a front-end component, for example, a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described in this disclosure, or any combination of one or more such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, for example, a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), an inter-network (for example, the Internet), and peer-to-peer networks (for example, ad hoc peer-to-peer networks). The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. In some implementations, a server transmits data (for example, an HTML page) to a client device (for example, for purposes of displaying data to and receiving user input from a user interacting with the client device). Data generated at the client device (for example, a result of the user interaction) can be received from the client device at the server. While this disclosure contains many specific implementation details, these should not be construed as limitations on the scope of any implementations or of what may be claimed, but rather as descriptions of features specific to particular implementations of particular implementations. Certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.

The present disclosure relates to computer-implemented methods and computer systems for providing user-friendly and understandable presentations of Open Data (OData) Protocol resources through an automatic translation and modification process. The present disclosure provides a user interface tool for presenting and browsing OData fees that can provide a visualization of an OData feed structure to users in an otherwise unavailable format. In particular, developers can view and modify resources outside of the underlying format in which such OData feeds are traditionally presented. The user interface tool can provide an out-of-box user interface with which a developer can view and modify resources associated with a feed, browse related entity sets, set filters, and perform other operations. In essence, the user interface tool can decrease user's efforts and difficult in understanding particular OData feeds and the entities associated therewith.

FIELD OF THE INVENTION The invention relates to the field of power conversion and in particular to the field of alternating current power conversion. BACKGROUND OF THE INVENTION It is well known to provide power converters for converting electrical power from one form into a different form that is useable under many specific circumstances for powering electrical load devices. For example, it is known to provide a direct current (DC) power supply that converts alternating current (AC) power into DC power for supplying DC electrical power to mobile devices. Additionally, it is known to provide an AC/DC power conversion device which is adapted to perform the power conversion in accordance with the power sources available in different countries. Another well known type of power conversion is the AC/DC type of conversion that is performed by light dimmers, wherein the peak-to-peak voltage of the output is maintained substantially the same as the peak-to-peak voltage of the input while the power conversion is accomplished by changing the duty cycle of the output. Commercial power in Europe is supplied at 220 VAC with a frequency of 50 Hertz (Hz). In the United States the standard voltage supplied is 120 VAC at 60 Hz. In addition, brownouts may significantly reduce a line voltage below the standard level and, conversely, lighter loads, particularly at night, may cause the line voltage to increase above the standard level. Additionally, corresponding variations in frequency are possible. Accordingly, power converters operating on the standard power suppliers to provide a DC source are typically designed to operate at frequencies between 47 and 65 Hz and with voltages ranging from 85 VAC to 265 VAC. Typically such a DC power supply converts an AC input voltage to a DC output voltage using an electromagnetic interference filter, a power factor correction circuit and a DC to DC converter. The electromagnetic interference filter is used in order to insure compliance with applicable electromagnetic interference standards. The power factor correction circuit converts AC power to a high DC voltage. For example, the high DC voltage can be 400 VDC. The DC to DC converter scales the high DC voltage down to a lower DC voltage as required by the load equipment to be powered by the power supply. U.S. Pat. No. 5,949,671, issued to Lee on Sep. 7, 1999 and entitled “Power Supply With Re-Configurable Outputs For Different Output Voltages and Methods Of Operation Thereof” teaches a type of DC power supply that is well known in the prior art. The DC power supply taught by Lee has a pair of output rectifying circuits that are coupled in alternate configurations to provide dual voltages at an output of the DC power supply. The voltage supply taught by Lee is thus capable of providing different output voltages using a single voltage controller. U.S. Pat. No. 4,626,981, issued to Su on Dec. 2, 1986 teaches a dual voltage converter circuit. The dual voltage converter circuit taught by Su converts an AC input voltage into an AC output voltage having a predetermined amplitude. The output voltage is coupled to a load circuit in order to energize the load circuit. When a relatively low amplitude AC mains supply voltage is applied to the converter the entire AC mains supply voltage is selectively coupled to a degaussing circuit without substantial amplitude change. On the other hand, when a relatively high amplitude AC mains supply voltage is provided a portion of the amplitude of the input AC mains supply voltage having an amplitude that approximates that of a lower AC mains supply voltages is coupled to the degaussing circuit. Su also teaches coupling an AC input voltage to a rectifier arrangement of a voltage converter to develop DC voltages in a pair of capacitors. The rectifier arrangement combines the AC input voltage with the voltages in the first and second capacitors, respectively, to produce an output voltage. The output voltage energizes an AC utilization circuit such as a degaussing circuit. During the positive portion of each cycle of the AC input voltage, the rectifier arrangement couples a positive difference voltage to the degaussing circuit. The positive difference voltage is formed between the positive portion of the AC input voltage and the voltage in the first capacitor to produce a positive level of the degaussing voltage. During the negative portion of each cycle of the AC input voltage, the rectifier couples a negative difference voltage to the degaussing circuit. The negative difference voltage is formed between the negative portion of the AC input voltage and the voltage in the second capacitor to produce a negative level of the degaussing voltage. However, the power converters taught by Lee and Su are suitable only for resistive loads. They are not suitable for powering devices having electronic loads primarily because of voltage spikes and other signal distortions present in the output voltage signals of these converters. For example, a 120 volt rms signal at the output of a converter such as the one taught by Su may have peaks approaching those of a 240 volt signal. Such peaks can destroy electronic circuitry. U.S. Pat. No. 4,314,327, issued to DePuy on Feb. 2, 1982, entitled “Transistor Drive Control For A Multiple Input DC To DC Converter” is an example of another type of prior art electrical energy conversion circuit. The conversion circuit taught by DePuy operates with major and minor variations in the level of applied input DC voltage and reduces the computational losses of its switching transistors that may other occur for the major and minor increases of the input DC voltage. A base drive current circuit in the DuPuy converter includes a full wave rectifier and multiple level current limiting circuit which is interposed between a base drive winding of a saturable transformer and the base electrodes of the transistors of first and second transistor diode combinations. The base drive current circuit adapts the saturation condition of the first and second transistor diode combinations to the level of the applied DC input voltages. This reduces the level of increase of the computational losses of the transistor diode combinations. Kruppa, in U.S. Pat. No. 5,805,439 issued on Sep. 8, 1998, teaches a DC to DC automatic switching circuit. The Kruppa device is a circuit for controlling multiple DC input voltages to produce a predetermined output voltage using a single DC to DC converter. Sensing of the DC input voltages supplied to the Kruppa switching device permits automatic switching in order to route an applied voltage between input terminals and output terminals. Furthermore, this switching permits configuring of a feedback network that selects the output voltage of the DC to DC converter. U.S. Pat. No. 5,654,884, entitled “Multistand AC/DC Converter With Baseline Crossing Detection” issued to Mohan on Aug. 5, 1997 provides circuitry for use in an integrated circuit controlled voltage doubler/bridge circuit. This circuitry is adapted to detect a period during which there is a lack of AC supply voltage following a period of AC input voltage within a predetermined range of values. When this occurs repeated triac firing pulses are provided such that the AC supply is rectified and doubled as soon as the AC supply voltage returns. Thus, it is known in the prior art to provide AC to AC converters which are not suitable for use with electronic devices. It is also known to provide converters which supply DC electrical energy suitable for use with electronic devices from an AC or a DC input. However, none of these devices are capable of providing AC/DC energy conversion suitable for use with electronic devices. It is known to solve these problems using a transformer. However, the use of a transformer increases the size, weight and cost of a power conversion device. SUMMARY OF THE INVENTION A method for performing power conversion in a power converter device provides a converter output AC waveform from a converter input AC waveform, the convertor input waveform having an input power level, an input frequency, an input waveform shape, and an input voltage/current characteristic. The converter input AC waveform is applied to a converter switch having a converter switch frequency and the switch is operated at the converter switch frequency to provide a switched waveform, the switched waveform having a plurality of switched waveform notches with a notch repetition rate substantially equal to the converter switch frequency. A filter performs filtering of the switched waveform to provide the converter output AC waveform having an output power level substantially equal to the input power level, an output frequency substantially equal to the input frequency, an output waveform shape substantially similar to the input wave form shape, and an output voltage/current characteristic substantially different from the input voltage/current characteristic. The output voltage/current characteristic has an output voltage level substantially less than an input voltage level of the input voltage/current characteristic and an output current level substantially higher than an input current level of the input voltage/current characteristic. The converter input AC waveform has a positive half cycle and a negative half cycle and the switched waveform notches are formed during both the positive half cycle and the negative half cycle of the converter input AC waveform. The input waveform shape can be a sine wave and the output waveform shape can be a sine wave. Additionally, the input waveform shape can be a square wave and the output waveform shape can be a square wave. The converter switch frequency is substantially higher than the input frequency and the filtering is performed by a filter having a filter a corner frequency that is at least twice as high as the input frequency. The converter switch frequency is substantially higher than the filter corner frequency. The filter has a frequency spectrum including a snitching component of the converter switch wherein the attenuation of the switching component by the filter is determined in accordance with the relationship: Attenuation in dB=12*log2(F sw 2F in ) and F sw represents the converter switch frequency and 2Fin represents the filter corner frequency. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram representation of the electronic power converter device of the present invention. FIG. 2 is a graphical representation of an input waveform which can be applied to the input of the electronic power converter device of FIG. 1 . FIG. 3 is a graphical representation of the operation of a switching circuit provided within the electronic power converter device of FIG. 1 . FIG. 4 is a graphical representation of an output waveform that can appear at the output of the electronic power converter device of FIG. 1 . FIG. 5 is a schematic representation of the circuitry of the electronic power converter device of FIG. 1 . FIG. 6 is a more detailed schematic representation of the circuitry of the electronic power converter device of FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown electronic power converter 10 of the present invention. During operation of electronic power converter 10 , an input AC waveform is applied to converter input port 12 which is defined by interconnect lines 18 , 22 . An output AC waveform is provided at converter output port 26 of electronic power converter 10 . Converter output port 26 is defined by interconnect lines 20 , 22 . Thus, interconnect line 22 is common to converter input port 12 and converter output port 26 . The signal of common interconnect line 22 is applied to triacs/diodes block 24 . Input interconnect line 18 is also applied to triacs/diodes block 24 . Additionally, input interconnect line 18 is coupled to an output of waveform chopping switch 16 in order to permit power conversion of an input AC waveform applied to converter input port 12 in accordance with the method of the invention. In order to perform conversion of an input AC waveform of converter input port 12 a plurality of triacs and diodes is provided within triacs/diodes block 24 . The triacs and diodes within triacs/diodes block 24 are adapted to switch into an off state under the control of waveform chopping switch 16 and to prevent signals from being applied to converter outport port 26 during portions of both the positive going cycles and the negative going cycles of the input AC waveform. This results in power conversion of an input AC signal while still providing an output signal having substantially the same frequency as the input which is suitable for application to a load device having electronic components therein. Referring now to FIGS. 2, 3 , 4 , there are shown input power waveform 40 , intermediate power waveform 50 , and converted output power waveform 60 , respectively. Each of the power waveforms 40 , 50 , 60 has a positive half cycle 42 and a negative half cycle 44 . The frequency, shape, power and phase of output power waveform 60 substantially follows those of input power waveform 40 , allowing for minor differences. The minor differences can be due to factors such as loss, noise and artifacts that may be introduced by electronic power converter 10 . Input power waveform 40 is applied to converter input port 12 for conversion by electronic power converter 10 of the present invention. Intermediate power waveform 50 is then created within triacs/diodes block 24 of electronic power converter 10 in accordance with waveform chopping switch 16 as part of the power conversion process of the present invention. Converted output power waveform 60 is the output AC waveform of electronic power converter 10 which is provided at converter outport port 26 . In order to convert input power waveform 40 into output power waveform 60 , a plurality of notches is formed in the input power waveform 40 during both the positive half cycles 42 and the negative half cycles 44 by the triacs and diodes of triacs/diodes block 24 . This results in the formation of waveform notches 52 and corresponding waveform peaks 54 shown in intermediate power waveform 50 . The manner in which the waveform notches 52 and waveform peaks 54 are formed by the triacs and diodes within triacs/diodes block 24 under the control of waveform chopping switch 16 as described in more detail below. Waveform chopping switch 16 in the preferred embodiment of the invention is a two pole low pass switch. Using waveform chopping switch 16 the waveform notches 52 are formed when waveform chopping switch 16 is in a first switch position and the waveform peaks 54 are formed when waveform chopping switch 16 is in a second switch position. Operation of waveform chopping switch 16 is controlled by switch control oscillator 14 . Switch control oscillator 14 can be adapted to have a switching frequency substantially higher than the frequency of input power waveform 40 in order to provide a suitable output power waveform 60 . For example, for a 60 Hz input power waveform 40 , the frequency of switch control oscillator 14 can be about 5 Kz. Intermediate power waveform 50 is filtered within electronic power converter 10 in order to provide the output power waveform 60 . While input power waveform 40 is shown as a sine wave, it will be understood that the method of the present invention can be applied to input and output waveforms of any shape. For example, if input power waveform 40 is a square wave, a step function or any other sinusoid, the shape of output power waveform 60 is the same as the shape of input power waveform 40 , i.e. a square wave, a step function or other sinusoid, respectively. Referring now to FIG. 5, there is shown a high level schematic representation of the electronic power converter 10 of the present invention. In the high level schematic representation of electronic power converter 10 , the input interconnect lines 22 , 18 , defining the converter input port 12 , are coupled, respectively to switch terminals 16 a, b of waveform chopping switch 16 . When waveform chopping switch 16 is in a first switch position input interconnect line 18 and switch terminal 16 b are electrically coupled to contact 16 c of waveform chopping switch 16 . In this first position of chopping switch 16 , input power waveform 40 is applied to converter outport port 26 by way of filter inductor 66 which removes the sum and difference products caused by chopping switch 16 in cooperation with output capacitor 68 . The signal at the output of filter inductor 66 is coupled to converter outport port 26 by way of interconnect line 20 . This position of chopping switch 16 corresponds to the waveform peaks 54 of the intermediate power waveform 50 . When waveform chopping switch 16 is in a second position, input interconnect line 22 of converter input port 12 is applied directly to filter inductor 66 . In this manner, the signal applied to output capacitor e by way of filter inductor 66 is substantially the same as the signal applied to the opposite end of output capacitor 68 by way of interconnect line 22 , thereby creating waveform notches 52 in intermediate power waveform 50 . Thus, it will be understood that the series of repeating waveform notches 52 and waveform peaks 54 of intermediate power waveform 50 are provided within electronic power converter 10 of the present invention as waveform chopping switch 16 is repeatedly thrown from one position of the first and second positions to the other. Furthermore, it will be understood that the unused power of the power conversion process of the present invention is reflected back to the power source that provides input power waveform 40 . The output filter formed by filter inductor 66 and output capacitor 68 can have a corner frequency of about 120 Hz depending on the permitted ripple of output power waveform 60 and the switching frequency of switch control oscillator 14 . The output filter of electronic power converter 10 must therefore be effective to remove the oscillator frequency and harmonics from output power waveform 60 . Broadly, one of the purposes of the output filter is to reduce the switching component of the power spectrum of output power waveform 60 to an acceptable level. In order to perform this function, the output filter formed by filter inductor 66 and output capacitor 68 is preferably a two pole lowpass filter with a typical roll off characteristic of approximately −12 dB per octave at frequencies above the filter corner frequency. The relationship of the filter corner frequency of electronic power converter 10 is given by 1/(2*PI*SQRT(LC)) where L is the inductance of filter inductor 66 and C is the capacitance of output capacitor 68 . If the corner frequency of the output filter is chosen to be sufficiently above the input frequency of input power waveform 40 there is negligible power loss in electronic power converter 10 . Such substantially low power loss is necessary to provide substantially the same power for power waveforms 40 , 60 . In order to meet this specification a good approximation of the output corner frequency can be to limit it to a value higher than an octave above the highest harmonic of interest in input power waveform 40 . The relationship of the switching frequency of waveform chopping switch 16 to the frequency of input power waveform 40 should be one in which the switching frequency is sufficiently higher than the frequency of input power waveform 40 so as to provide sufficient attenuation of the switching component in the spectrum by the output filter while not providing substantial attenuation of input power waveform 40 . It the input frequency, F in , is a sinusoid and the corner frequency of the output filter is chosen to be 2F in , the relationship between the switching frequency and the amount of attenuation of switching component in the spectrum of the output signal is as follows: Attenuation in dB=12*log2(F sw /2F in ), where F sw is the switching frequency and 2F in is twice the corner frequency of the output filter. Intermediate power waveform 50 , formed in this manner, appears at the input of waveform chopping switch 16 . Intermediate power waveform 50 appears between chopping switch 16 and filter inductor 66 . Output power waveform 60 appears at the output of filter inductor 66 . It will be understood by those skilled in the art that electronic power converter 10 thus performs the AC/AC power conversion of the present invention independently of any AC/DC conversion and independently of any DC/DC or DC/AC power conversions. Referring now to FIG. 6, there is shown a more detailed schematic representation of power converter device 10 of the present invention, including a more detailed representation of switch control oscillator 14 . Switch control oscillator 14 can be a conventional feedback operational amplifier oscillator circuit 70 . As previously described the oscillation frequency of feedback operational amplifier circuit 70 should be substantially higher than the frequency of input power waveform 40 . The output of operational amplifier oscillator 70 is driven by drive transistors 72 and drive MOSFET 73 prior to being applied to waveform chopping switch 16 in order to permit operational amplifier oscillator circuit 70 to control the switching of chopping switch 16 . It will be understood that chopping switch 16 in the preferred embodiment of the invention may be energized by a DC voltage, although no DC conversion is involved in performing its operations. In this manner input power waveform 40 and the oscillator frequency of oscillator circuit 70 are multiplied by each other. It will be understood by those skilled in the art that chopping switch 16 can be triggered at any phase within the input power waveform 40 since the triggering of chopping switch 16 is not synchronized with any line voltage or any other reference signal. In the preferred embodiment of the invention, the duty cycle of the output signal of oscillator circuit 70 can be approximately fifty percent. However, it will be understood by those skilled in the art that the duty cycle of the output signals of oscillator circuit 70 is determined by the power division factor required between input power waveform 40 and output power waveform 60 . Output terminal 80 a of waveform chopping switch 16 is applied to the gates of two triacs 76 a,b within triacs/diodes block 24 byway of respective diodes 74 a,b . Diodes 74 a,b are coupled to output terminal 80 a of chopping switch 16 with opposite pluralities. Thus, during one-half cycle of input power waveform 40 the gate of triac 76 a is triggered by diode 74 a and during the other half-cycle triac 76 a is in a conducting state. In this manner the input of filter inductor 66 is alternately connected to either input interconnect line 18 or input interconnect line 22 of converter input port 12 to alternately form the waveform notches 52 and the waveform peaks 54 of intermediate power waveform 50 as previously described. The signals of triacs 76 a,b are applied to filter inductor 66 by way of clamping diodes 78 a,b . Clamping diodes 78 a,b provide return current paths for filter inductor 66 when triacs 76 a,b are alternately conducting. Thus, the frequency, the waveform shape and the power of output power waveform 60 are substantially the same as the frequency, the waveform shape, and the power of input power waveform 40 while, simultaneously, the voltage/current characteristics of power waveforms 40 , 60 can differ substantially. The differences in voltage/current characteristics between power waveforms 40 , 60 can be controlled in accordance with the duty cycle of switch control oscillator 14 and, thereby, the duty cycle of waveform notches 52 and waveform peaks 54 within intermediate power waveform 50 . An example of such a power conversion wherein voltage and current are converted but the frequency, waveform shape, and power are not converted can be as follows. The voltage/current characteristics of input power waveform 40 can be, for example, 100 watts input at 100 volts and 1 amp. The 100 watt input power waveform 40 can be converted into an output power waveform 60 of approximately 100 watts at 50 volts and 2 amps. Thus, the conversion performed by electronic power converter 10 is in accordance with Watt's Law, wherein the decrease in voltage level is accompanied by a corresponding proportional increase in the current level. The conversion of power without conversion of frequency, waveform shape or power is similar to the conversion performed by a conventional step down transformer or by an impedance transformation. Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge adopt the same for use under various conditions of service.

A method for performing power conversion provides a converter output AC waveform from a converter input AC waveform, the convertor input waveform having an input power level, an input frequency, an input waveform shape, and an input voltage/current characteristic. The converter input AC waveform is applied to a converter switch with a switch frequency and the switch is operated at the switch frequency to provide a switched waveform having a plurality of switched waveform notches with a notch repetition rate substantially equal to the switch frequency. A filter performs filtering of the switched waveform to provide the converter output AC waveform with an output power level substantially equal to the input power level, an output frequency substantially equal to the input frequency, an output waveform shape substantially similar to the input wave form shape, and an output voltage/current characteristic substantially different from the input voltage/current characteristic.

RELATED APPLICATIONS This application claims priority to U.S. Provisional Application Serial No. 60/318,389 filed Sep. 10, 2001. FIELD OF THE INVENTION The present invention relates to compositions and methods for wrinkle reduction in fabrics, including washable clothes, dry cleanable clothes, linens, bed clothes, draperies, window curtains, shower curtains, table linens, and the like requiring little, if any, pressing, ironing, and/or steaming are disclosed. BACKGROUND OF THE INVENTION Bending and creasing cause wrinkles in textile fabrics by placing an external portion of a yarn filament under tension while the internal portion of the yarn filament is under compression. With cotton fabrics particularly, the hydrogen bonding that occurs between the cellulose molecules contributes to maintaining the wrinkles. The wrinkling of fabric, particularly clothing and household fabrics, is therefore subject to the inherent tensional elastic deformation and recovery properties of the individual fibers that make up the yarn. In order to reduce wrinkles and provide fabric articles with a presentable appearance, the articles must either be pressed or steamed. Both processes involve exposing the articles to heat in order to relax wrinkles. Both processes also require an implement, heat-up time, and manual exposure of the articles to heat. Pressing, ironing, and steaming are labor-intensive tasks that require time to conduct. This labor and time is in addition to any cleaning and/or refreshing steps that must be taken prior to re-wear of articles. Some consumers send articles to costly dry cleaning service providers for cleaning just to avoid the additional step of pressing, ironing, or steaming—even if the consumer is willing and able to clean the articles themselves. Increasingly however, consumers are subjected to more hectic lives and, as a result, demand less labor-intensive and/or more cost efficient fabric care either in the home or from commercial service providers. This demand has increased the pressure on textile technologists to create products that sufficiently reduce wrinkles in fabrics, especially clothing and household fabrics, and to produce a presentable fabric appearance with the convenient application of these products. Accordingly, there is a need for wrinkle control in fabrics, including washable clothes, dry cleanable clothes, linens, bed clothes, draperies, window curtains, shower curtains, table linens, and the like requiring little, if any, pressing, ironing, and/or steaming. A solution would be capable of being used on damp or dry clothing to relax wrinkles and give clothes a ready to wear or ready to use look that is demanded by today's hectic society. SUMMARY OF THE INVENTION The need is met by the present invention wherein compositions and methods for wrinkle reduction in fabrics, including washable clothes, dry cleanable clothes, linens, bed clothes, draperies, window curtains, shower curtains, table linens, and the like requiring little, if any, pressing, ironing, and/or steaming are disclosed. The present invention is suitable for application on damp or dry clothing to relax wrinkles and give clothes a ready to wear or ready to use look that is demanded by today's hectic society. The present invention comprises both compositions and methods for reducing wrinkles in fabrics. In one embodiment, the present invention provides a fabric treatment composition comprising: (a) an effective amount, in one embodiment from about 0.001% to no greater than about 25% by weight of the composition, of a polymer to control wrinkles in fabric articles; (b) a co-solvent; and (c) a carrier. In another embodiment, the present invention provides a method comprising the steps of: (a) applying a fabric treating composition of the present invention; (b) applying a fabric cleaning composition comprising a lipophilic fluid; and (c) removing mechanically at least a portion of the fabric cleaning composition. Accordingly, the present invention provides compositions and methods employing such compositions that reduce and/or control wrinkles in fabric articles. DETAILED DESCRIPTION OF THE INVENTION Definitions The term “fabric article” used herein is intended to mean any article that is customarily cleaned in a conventional laundry process or in a dry cleaning process. As such the term encompasses articles of clothing, linen, drapery, and clothing accessories. The term also encompasses other items made in whole or in part of fabric, such as tote bags, furniture covers, tarpaulins and the like. The term “spraying” and/or “spray” used herein encompasses a means for applying droplets of the cleaning fluid to a fabric article. Typically, the droplets may range in average droplet size tram about 100 μm to about 1000 μm, preferably from about 50 μm to about 1000 μm. As used herein, the term also encompasses “mist” and/or “misting” and “fog” and/or “fogging”, those terms being subclasses of “spray” and/or “spraying” and are on the small side of the average droplet size. The “spray” may be made by any suitable means known to those in the art. Nonlimiting examples include passing the cleaning fluid through nozzles, atomizers, ultrasonic devices and the like. The term “lipophilic fluid” used herein is intended to mean any non-aqueous fluid capable of removing sebum, as described in more detail hereinbelow. The term “textile treatment liquid” used herein is intended to mean any liquid, aqueous or non-aqueous, suitable for cleaning, conditioning or sizing of fabrics. The lipophilic fluid and the textile treatment liquid will be referred to generically as the “cleaning fluid”, although it should be understood that the term encompasses uses other than cleaning, such as conditioning and sizing. Furthermore, optional adjunct ingredients such as surfactants, bleaches, and the like may be added to the “cleaning fluid”. That is, adjuncts may be optionally combined with the lipophilic fluid and/or the textile treatment liquid. These optional adjunct ingredients are described in more detail hereinbelow. The term “cleaning composition” and/or “treating composition” used herein are intended to mean any lipophilic fluid-containing composition that comes into direct contact with fabric articles to be cleaned. It should be understood that the term encompasses uses other than cleaning, such as conditioning and sizing. The phrase “dry weight of a fabric article” as used herein means the weight of a fabric article that has no intentionally added fluid weight. The phrase “absorption capacity of a fabric article” as used herein means the maximum quantity of fluid that can be taken in and retained by a fabric article in its pores and interstices. Absorption capacity of a fabric article is measured in accordance with the following Test Protocol for Measuring Absorption Capacity of a Fabric Article. Test Protocol for Measuring the Absorption Capacity of a Fabric Article Step 1: Rinse and dry a reservoir or other container into which a lipophilic fluid will be added. The reservoir is cleaned to free it from all extraneous matter, particularly soaps, detergents and wetting agents. Step 2: Weigh a “dry” fabric article to be tested to obtain the “dry” fabric article's weight. Step 3: Pour 2 L of a lipophilic fluid at ˜20 C. into the reservoir. Step 4: Place fabric article from Step 2 into the lipophilic fluid-containing reservoir. Step 5: Agitate the fabric article within the reservoir to ensure no air pockets are left inside the fabric article and it is thoroughly wetted with the lipophilic fluid. Step 6: Remove the fabric article from the lipophilic fluid-containing reservoir. Step 7: Unfold the fabric article, if necessary, so that there is no contact between same or opposite fabric article surfaces. Step 8: Let the fabric article from Step 7 drip until the drop frequency does not exceed 1 drop/sec. Step 9: Weigh the “wet” fabric article from Step 8 to obtain the “wet” fabric article's weight. Step 10: Calculate the amount of lipophilic fluid absorbed for the fabric article using the equation below. FA =( W−D )/ D* 100  where: FA=fluid absorbed, % (i.e., the absorption capacity of the fabric article in terms of % by dry weight of the fabric article) W=wet specimen weight, g D=initial specimen weight, g By the term “non-immersive” it is meant that essentially all of the fluid is in intimate contact with the fabric articles. There is, at most, minimal amounts of “free” wash liquor. It is unlike an “immersive” process where the washing fluid is a bath in which the fabric articles are either submerged, as in a conventional vertical axis washing machine, or plunged into, as in a conventional horizontal washing machine. The term “non-immersive” is defined in greater detail according to the following Test Protocol for Non-Immersive Processes. A process in which a fabric article is contacted by a fluid is a non-immersive process when the following Test Protocol is satisfied. Test Protocol for Non-Immersive Processes Step 1: Determine absorption capacity of a fabric specimen using Test Protocol for Measuring Absorption Capacity of a Fabric Article, described above. Step 2: Subject a fabric article to a fluid contacting process such that a quantity of the fluid contacts the fabric article. Step 3: Place a dry fabric specimen from Step 1 in proximity to the fabric article of Step 2 and move/agitate/tumble the fabric article and fabric specimen such that fluid transfer from the fabric article to the fabric specimen takes place (the fabric article and fabric specimen must achieve the same saturation level). Step 4: Weigh the fabric specimen from Step 3. Step 5: Calculate the fluid absorbed by the fabric specimen using the following equation: FA =( W−D )/D*100  where: FA=fluid absorbed, % W=wet specimen weight, g D=initial specimen weight, g Step 6: Compare the fluid absorbed by the fabric specimen with the absorption capacity of the fabric specimen. The process is non-immersive if the fluid absorbed by the fabric specimen is less than about 0.8 of the absorption capacity of the fabric specimen. Vapor Permeability Test Protocol The purpose of this test is to determine the ability of water vapor to transport through fabric. 1. Cut test fabric to 4 inches square. 2. Place the fabric over a small jar filled with water. The fabric should be out-side facing up. Secure the fabric with a band., 3. Record the weight of the jar with fabric and water and band (initial wt.) 4. Allow the jar to stand over-night (˜16 hrs.) at ambient temperatures 5. Repeat this test with no less than 3-replicates for each test condition. 6. Next day, weigh the jars and determine the % weight loss from the initial weight. Even though the present invention is discussed in detail with respect to non-immersive fabric treating processes, immersive fabric treating processes are within the broad scope of the present invention. By the term “immersive” as used herein it is meant that excess, free-standing (i.e., above the absorption capacity of the fabric articles) cleaning composition is in contact with the fabric articles. Pilling and Abrasion Test Method The abrasion test used in this invention is described in ASTM D4966 and in the Nu-Martindale Abrasion and Pilling Tester Operator's Guide as supplied by the Manufacturer Martindale Compositions The present invention relates to lipophilic wrinkle reducing, removing and/or controlling compositions comprising a polymer containing carboxylic acid moieties, that is preferably stable, well-dispersed opaque, translucent, or clear suspensions, dispersions, or solutions with the dispersed or solubilized polymer particulates being very small in particle size, that distribute evenly from dispensers to prevent staining. Specified pH solutions are acceptable if these have the low viscosity that is necessary to provide acceptable dispensing. The present invention also relates to preferred compositions containing, in addition to the essential carboxylic acid containing polymer and carrier, optional, but preferred ingredients, e.g. polyalkylene oxide polysiloxane, fabric care polysaccharides, odor control components, co-solvent, and minors such as perfume and preservative, adjusted to a specified pH to provide both good dispensing properties and improved stability to shear forces (e.g. stirring during processing or shaking that occurs during transit). The present invention further relates to methods of formulating such compositions, as well as fabric wrinkle control methods and articles of manufacture that comprise such fabric wrinkle controlling compositions. The fabric wrinkle control compositions typically comprise: (a) at least an effective amount to control wrinkles in fabric of a polymer preferably selected from the group of polymers comprising carboxylic acid moieties that can be suspended, dispersed or solubilized at a specified pH range to produce a lipophilic solution with a viscosity lower than the viscosity of that polymer composition at a pH above the specified pH range and with the viscosity of the solution preferably below about 20 centipoise (“cP”), more preferably below about 15 cP, even more preferably below about 12 cP, even more preferably below about 10 cP, still more preferably below about 7 cP and most preferably below about 3 cP, with the polymer incorporated at a level that is at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.05%, and still more preferably at least about 0.1% and even more preferably at least about 0.25% and most preferably at least about 0.5% and at a level of no greater than about 25%, more preferably no greater than about 10%, even more preferably no greater than about 7%, and still more preferably no greater than about 5% by weight of the usage composition; mixtures of polymers are also acceptable in the present composition; and (b) at least an effective amount of a co-solvent, preferably water, at a level that is at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.05%, and still more preferably at least about 0.1% and even more preferably at least about 0.25% and most preferably at least about 0.5% and at a level of no greater than about 25%, more preferably no greater than about 10%; and, (c) at least an effective amount of a carrier, preferably lipophilic fluid. The polymer compositions of the present invention can optionally further comprise silicone compounds and/or emulsions especially those compounds that impart lubricity and softness, as well as those that reduce surface tension. Non-limiting examples include silicones modified with alkylene oxide moieties compounds. Mixtures of silicones that provide desired benefits are also acceptable in the present composition. Another option is an effective amount of a supplemental wrinkle control agent selected from the group consisting essentially of (1) adjunct polymer (2) fabric care polysaccharides, (3) lithium salts, (4) fiber fabric lubricants, and (5) mixtures thereof. Other options include an effective amount of a supplemental surface tension control agent, an effective amount to soften fibers and/or polymer of hydrophilic plasticizer wrinkle control agent, an effective amount of odor control agent to absorb or reduce malodor, and/or an effective amount of perfume to provide olfactory effects. Yet another option is an effective amount of solubilized, water-soluble, anti-microbial preservative, preferably from about 0.0001% to about 0.5%, more preferably from about 0.0002% to about 0.2%, most preferably from about 0.0003% to about 0.1%, by weight of the composition. The present compositions are preferably essentially free of materials that would soil or stain fabric under usage conditions, or preferably free of materials at a level that would soil or stain fabrics unacceptably under usage conditions. The present invention also relates to concentrated compositions, including liquid, fluid and solid forms of concentrated compositions that may be diluted to form compositions with the usage concentrations for use under usage conditions. It is preferred that the concentrated compositions be delivered in forms that rapidly and smoothly dissolve or disperse to the usage concentration The present invention also relates to combining the composition with a substrate and/or device capable of containing said composition for release at a desirable time in a fabric treatment process to create an article of manufacture. Such articles of manufacture can facilitate treatment of fabric articles and/or surfaces with said pH adjusted polymer compositions containing wrinkle control agent and other optional ingredients at a level that is effective, yet not discernible when dried on the surfaces of said fabric. The article of manufacture can operate in mechanical devices designed to alter the physical properties of articles and/or surfaces such as, but not limited to, a clothes dryer or mechanical devices designed to spray fabric care compositions on fabrics or clothes. The present invention further relates to fabric wrinkle control methods and articles of manufacture that comprise the present pH adjusted polymer compositions in lipophilic fluid. The present articles of manufacture preferably comprise the present compositions incorporated into a container, preferably a spray dispenser, to facilitate the treatment of fabric surfaces with said polymer compositions comprising polymer and other optional ingredients at a level that is effective, yet is not discernible when dried on the surfaces. The spray dispenser can comprise a manually-activated or non-manually powered spray means and container containing the present compositions. The present invention also relates to concentrated compositions, including liquids, solution, and solids (such as, but not limited to, granules and flakes), wherein the level of wrinkle control agent is typically at least about 1% preferably at least about 5%, more preferably at least about 10%, still more preferably at least about 30% and typically less than about 100%, preferably less than about 99%, more preferably less than about 95%, and even more preferably less than about 90%, by weight of the concentrated composition. The concentrated composition is typically diluted to form usage compositions, with usage concentrations of, e.g., from about 0.025% to about 25%, by weight of the usage composition, of wrinkle control active as given hereinabove. Preferably the concentrated composition dilutes smoothly to appropriate usage levels. Specific levels of other optional ingredients in the concentrated composition can readily be determined from the desired usage composition and the desired degree of concentration. Polymers comprising carboxylic acid moieties are preferred for fabric treatment because these polymers provide the desirable qualities of wrinkle removal, reduction and/or control, smoothness, and body desirable from polymers, but do not tend to attract build up of dingy soil in subsequent treatments (wash cycles) as do some other polymers especially cationic polymers. However, when polymers containing carboxylic acid moieties are neutralized, these tend to build a high level of viscosity in the composition, leading to poor dispensing in the form of a highly concentrated spray that will tend to stain fabrics. Water is inexpensive and effective at breaking hydrogen bonds. Lipophilic fluid and polymers are effective at helping to lubricate fibers, but especially at holding fibers and fabrics in place once the desired smoothness is achieved to retain the smoothness. Polymer compositions disclosed within are typically applied to fabrics by spraying either from a container or within a some type of mechanical chamber (e.g. dryer) for altering the properties of fabrics. Therefore to prevent fabric staining, it is important to have a polymer composition that mists or aerosolizes rather than streaming. The polymer compositions in lipophilic fluid of the present invention typically comprise: (A) an effective amount to control wrinkles in fabric of a polymer preferably selected from the group consisting of polymers comprising carboxylic acid moieties that can be suspended or solubilized in at lower pH to produce a solution with a viscosity lower than the viscosity of that polymer composition when the pH is above the specified pH range and with the viscosity of the solution preferably below about 20 cP, more preferably below about 15 cP, even more preferably below about 12 cP, even more preferably below about 10 cP, still more preferably below about 7 cP and most preferably below about 3 cP with the said polymer incorporated at a level that is at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.05%, and still more preferably at least about 0.1% and even more preferably at least about 0.25% and most preferably at least about 0.5% and at a level of no greater than about 25%, more preferably no greater than about 10%, even more preferably no greater than about 7%, and still more preferably no greater than about 5% by weight of the usage composition; mixtures of polymers are also acceptable in the present composition; and (B) a co-solvent, that is preferably water; and (C) a carrier, that is preferably a lipophilic fluid. The preferred polymer compositions of the present invention can optionally further comprise: (A) optionally, but preferably, silicone compounds and emulsions. Silicone compounds that impart lubricity and softness are highly preferred. Silicones that reduce surface tension are also highly preferred. A preferred class of silicone materials includes silicones modified with alkylene oxide moieties compounds; mixtures of silicones that provide desired benefits are also acceptable in the present composition; (B) optionally, an effective amount of a supplemental wrinkle control agent selected from the group consisting of (1) adjunct polymer free of carboxylic acid moieties (2) polysaccharides, (3) lithium salts, (4) fiber fabric lubricants, and (5) mixtures thereof; (C) optionally, an effective amount of a supplemental surface tension control agent; (D) optionally, an effective amount to soften fibers and/or of hydrophilic plasticizer wrinkle control agent; (E) optionally, but preferably, at least an effective amount to absorb or reduce malodor, of odor control agent; (F) optionally, but preferably, an effective amount to provide olfactory effects of perfume; (G) optionally, an effective amount of solubilized, water-soluble, antimicrobial preservative, preferably from about 0.0001% to about 0.5%, more preferably from about 0.0002% to about 0.2%, most preferably from about 0.0003% to about 0.1%, by weight of the composition; (H) optionally, an effective amount to adjust and control pH of a pH adjustment system; (I) optionally, other ingredients such as adjunct odor-controlling materials, chelating agents, viscosity control agents, additional antistatic agents if more static control is desired, insect and moth repelling agents, colorants; whiteness preservatives; and; (J) mixtures of optional components (A) through (I). The present polymer compositions are preferably essentially free of any material that would soil or stain fabric under usage conditions, or at least do not contain such materials at a level that would soil or stain fabrics unacceptably under usage conditions. The present compositions are preferably applied as small droplets to fabric when used as a wrinkle spray. The following describes the ingredients, including optional ingredients, of the present polymer compositions in further detail. Polymer (A) Carboxylic Acid Moiety-Based Polymers The polymers comprising carboxylic acid moieties can be natural, or synthetic, and hold fibers in place following drying by forming a film, providing adhesive properties, and/or by other mechanisms. The polymer is typically a homopolymer or a copolymer containing unsaturated organic mono-carboxylic and polycarboxylic acid monomers, and salts thereof, and mixtures thereof. The polymer comprising carboxylic acid moieties is incorporated in the present compositions at a level that is at least about 0.001%, preferably at least about 0.01%, and more preferably at least about 0.05%, and still more preferably at least about 0.1% and even more preferably at least about 0.25% and most preferably at least about 0.5% and at a level of no greater than about 25%, more preferably no greater than about 10%, even more preferably no greater than about 7%, and still more preferably no greater than about 5% by weight of the usage composition. Polymers comprising carboxylic acid moieties provide the desired properties of wrinkle removal, reduction, and/or control as well as acting to retain the smooth appearance of fabrics as fibers dry and after fibers dry plus providing body without acting to attract soil as some other polymers tend to do, particularly cationic polymers. Polymers comprising carboxylic acid moieties have been typically formulated at pH's above about 6 in order to generate clear solutions. Clear solutions were believed to be preferred for preventing visible residue on fabrics after use. However, when polymers comprising carboxylic acid moieties are solubilized at relatively high pH's these tend to build an unacceptable level of viscosity of the composition which impairs dispensing of the spray. Polymer compositions with high viscosities tend to dispense as streams, which results in staining of fabric. Surprisingly, it is found that when compositions are at a specified pH, even when these compositions are dispersions of small-size polymer particulates, as opposed to clear solutions containing solubilized polymer, that these compositions tend to dispense as a finer mist—and actually result in less staining than polymer compositions at higher pH's. As the pH of the carboxylic acid polymer compositions rises, the carboxylic acid moieties tend to de-protonate generating negatively charged head groups along the chain. Electrostatic repulsion between ionized head groups causes the polymers to increase their effective size in solution thus resulting in entanglements between polymers, which raise the viscosity. When viscosity rises, dispensing of the product in the form of a spray becomes difficult because the spray tends to stream, thus focusing an unacceptable volume of product on a small area of the fabric. It was surprisingly found that when the viscosity of the carboxylic acid polymer composition is reduced, by reducing the pH, streaming does not occur. Polymers suitable for this composition disperse or dissolve in solution at low pH to generate a composition with small particles having a viscosity preferably below about 20 cP, more preferably below about 15 cP, even more preferably below about 12 cP, even more preferably below about 10 cP, still more preferably below about 7 cP and most preferably below about 3 cP. When preferred optional ingredients, e.g. alkylene oxide polysiloxane copolymer, fabric care polysaccharide, odor control components, solvent, and minor ingredients such as perfume and preservative, are added to the carboxylic acid polymer composition, the product tends to become unstable at pH's outside the specified pH range. Many of the preferred optional ingredients (e.g. alkylene oxide polysiloxane, perfume) tend to be hydrophobic and therefore may complex with the polymer if the polymer is significantly protonated. The lower the pH, the more protonated a carboxylic acid-containing polymer becomes and the less electrostatic charge it has. The polymer also become less water soluble and less able to disperse via electrostatic charge mechanisms. Therefore, when the essential polymer is formulated with optional preferred ingredients, especially hydrophobic ingredients, such as polyalkylene oxide polysiloxanes, it can tend to complex with these ingredients and form a precipitate. It is found that shear forces, such as the stirring that occurs during processing or the shaking that can occur during transport, can lead to precipitation of the formula. It is further found that by maintaining a pH within a specified pH range as the formulation is processed, makes the formulation much more stable to shear forces and also maintains a low enough viscosity to allow for acceptable spray dispensing of the final composition. Therefore, when optional preferred ingredients are added to the polymer composition, it is preferred to maintain the pH throughout process and of the finished product within a specified pH range described herein. Polymers comprising carboxylic acid moieties suitable for the present composition can be natural, or synthetic, and can, as disclosed above, act to hold fibers in place after wrinkles are smoothed out as the fabric dries and after the fabric dries by forming a film, and/or by providing adhesive properties and/or by other mechanisms that act to fix the fibers in place. By “adhesive”, it is meant that when applied as a solution or a dispersion to a fiber surface and dried, the polymer can attach to the surface. The polymer can form a film on the surface, or when residing between two fibers and in contact with the two fibers, it can bond the two fibers together. Other polymers such as starches can form a film and/or bond the fibers together when the treated fabric is pressed by a hot iron. Such a film will have adhesive strength, cohesive breaking strength, and cohesive breaking strain. The synthetic polymers useful in the present invention are comprised of monomers containing carboxylic acid moieties. The polymer can be a homopolymer or a copolymer. The polymer can comprise additional non-carboxylic acid monomers to form copolymers. Copolymers can be either graft or block copolymers. Cross-linked polymers are also acceptable. Some non-limiting examples of carboxylic acid monomers which can be used to form the synthetic polymers of the present invention include: low molecular weight C 1 -C 6 unsaturated organic mono-carboxylic and polycarboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid and its half esters, itaconic acid, and mixtures thereof. Some preferred, but non-limiting monomers include acrylic acid; methacrylic acid; and adipic acid. Salts of carboxylic acids can be useful in generating the synthetic polymers or copolymers as long as the final composition is within a specified pH range and has a viscosity consistent with generating a desirable spray pattern. Additional non-limiting monomers that can be used to generate copolymers comprising carboxylic acid moieties include esters of said acids with C 1 -C 12 alcohols, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 1-methyl-1-butanol, 3-methyl-1-butanol, 1-methyl-1-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, t-butanol, cyclohexanol, 2-ethyl-1-butanol, neodecanol, 3-heptanol, benzyl alcohol, 2-octanol, 6-methyl-t-heptanol, 2-ethyl-1-hexanol, 3,5-dimethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, 1-decanol, 1-dodecanol, and the like, and mixtures thereof. Nonlimiting examples of said esters are methyl acrylate, ethyl acrylate, t-butyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, methoxy ethyl methacrylate, and mixtures thereof; amides and imides of said acids, such as N,N-dimethylacrylamide, N-t-butyl acrylamide, maleimides; low molecular weight unsaturated alcohols such as vinyl alcohol (produced by the hydrolysis of vinyl acetate after polymerization), allyl alcohol; esters of said alcohols with low molecular weight carboxylic acids, such as, vinyl acetate, vinyl propionate; ethers of said alcohols such as methyl vinyl ether; aromatic vinyl such as styrene, alpha-methylstyrene, t-butylstyrene, vinyl toluene, polystyrene macromer, and the like; polar vinyl heterocyclics, such as vinyl pyrrolidone, vinyl caprolactam, vinyl pyridine, vinyl imidazole, and mixtures thereof; other unsaturated amines and amides, such as vinyl amine, diethylene triamine, dimethylaminoethyl methacrylate, ethenyl formamide; vinyl sulfonate; salts of acids and amines listed above; low molecular weight unsaturated hydrocarbons and derivatives such as ethylene, propylene, butadiene, cyclohexadiene, vinyl chloride; vinylidene chloride; and mixtures thereof and alkyl quaternized derivatives thereof, and mixtures thereof. Preferably, said monomers are selected from the group consisting of vinyl alcohol; methyl acrylate; ethyl acrylate; methyl methacrylate; t-butyl acrylate; t-butyl methacrylate; n-butyl acrylate; n-butyl methacrylate; isobutyl methacrylate; 2-ethylhexyl methacrylate; dimethylaminoethyl methacrylate; N,N-dimethyl acrylamide; N,N-dimethyl methacrylamide; N-t-butyl acrylamide; vinylpyrrolidone; vinyl pyridine; diethylenetriamine; salts thereof and alkyl quaternized derivatives thereof, and mixtures thereof. Preferably, said monomers form homopolymers and/or copolymers (i.e., the film-forming and/or adhesive polymer) having a glass transition temperature (Tg) of from about −20° C. to about 150° C., preferably from about −10° C. to about 150° C., more preferably from about 0° C. to about 100° C., most preferably, the adhesive polymer hereof, when dried to form a film will have a Tg of at least about 25° C., so that they are not unduly sticky, or “tacky” to the touch. Preferably said polymer comprising carboxylic acid moieties is soluble and/or dispersible in water and/or alcohol. Said polymer typically has a molecular weight of at least about 500, preferably from about 1,000 to about 2,000,000, more preferably from about 5,000 to about 1,000,000, and even more preferably from about 30,000 to about 300,000 for some polymers. Some non-limiting examples of homopolymers and copolymers which can be used as film-forming and/or adhesive polymers of the present invention are:—adipic acid/dimethylaminohydroxypropyl diethylenetriamine copolymer; ethyl acrylate/methacrylic acid copolymer, adipic acid/epoxypropyl diethylenetriamine copolymer; ethyl acrylate/methyl methacrylate/methacrylic acid/acrylic acid copolymer. Nonlimiting examples of preferred polymers that are commercially available include ethyl acrylate/methacrylic acid copolymer such as Luvifle® Soft and t-butyl acrylate/ethyl acrylate/methacrylic acid copolymer such as Luvimer® 36D from BASF. The present compositions containing polymer comprising carboxylic acid moieties can be formulated such that the pH is within a specified pH range. As such, the present compositions have a pH that is at least about 1, preferably at least about 3, and more preferably at least about 5, and that is less than about 7. The preferred pH ranges are from about 3 to about 7, preferably from about 4 to about 6.5, and more preferably from about 5.0 to about 6.0. When optional preferred ingredients are added to the polymer composition it is preferred that the pH of the carboxylic acid polymer composition be within the specified pH range. The viscosity of the present usage composition is typically below about 20 cP, preferably below about 15 cp, more preferably below about 12 cp, even more preferably below about 10 cp, still more preferably below about 7 cP, and most preferably below about 5 cP. The polymer comprising carboxylic acid moieties is incorporated at a level that is typically at least about 0.001%, preferably at least about 0.01%, more preferably at least about 0.05%, still more preferably at least about 0.25% and most preferably at least about 0.5% and typically lower than about 25%, preferably lower than about 10%, more preferably lower than about 7%, still more preferably lower than about 5%. The level at which the polymer is incorporated is consistent with achieving a low viscosity composition that provides improved dispensing characteristics. It is not intended to exclude the use of higher or lower levels of the polymers, as long as an effective amount is used to provide wrinkle removal, reduction, and/or control, body and the adhesive, film-forming properties or fixative properties necessary to hold fibers in a smooth conformation as drying occurs and after the fabric dries and as long as the composition can be formulated and effectively applied for its intended purpose and the viscosity of the final composition is acceptable. Concentrated compositions can also be used in order to provide a less expensive product. When a concentrated product is used, i.e., the polymer is incorporated at a level that is typically about 1% to about 100%, by weight of the concentrated composition. It is preferable to dilute such a concentrated composition before treating fabric. Preferably, the concentrated composition is diluted with about 50% to about 400,000%, more preferably from about 50% to about 300,000%, and even more preferably from about 50% to about 200,000%, even more preferably from about 50% to about 125,000% by weight of the composition, of water. Liquid concentrates are acceptable, but solid concentrates are preferred. Preferred concentrates will dilute smoothly from the concentrated state to the usage state. (B) Silicone-Base Polymers Another set of highly preferred adhesive and/or film forming polymers that are useful in the composition of the present invention comprise silicone moieties in the polymers. These preferred polymers include graft and block copolymers of silicone with moieties containing hydrophilic and/or hydrophobic monomers described hereinbefore. The silicone-containing copolymers in the spray composition of the present invention provide shape retention, body, and/or good, soft fabric feel. Both silicone-containing graft and block copolymers useful in the present invention as polymers comprising carboxylic acid moieties typically have the following properties: (1) The polymer comprises carboxylic acid moieties; (2) the silicone portion is covalently attached to the non-silicone portion; (3) the molecular weight of the silicone portion is from about 1,000 to about 50,000 and; (4) the non-silicone portion must render the entire copolymer dispersible or soluble in the wrinkle control composition vehicle and permit the copolymer to deposit on/adhere to the treated fabrics. Suitable silicone copolymers include the following: (1) SILICONE GRAFT COPOLYMERS Silicone-containing polymers useful in the present invention are the silicone graft copolymers comprising carboxylic acid moieties as disclosed above. Polymers of this description, along with methods for making them are described in U.S. Pat. No. 5,658,557, Bolich et al., issued Aug. 19, 1997, U.S. Pat. No. 4,693,935, Mazurek, issued Sep. 15, 1987, and U.S. Pat. No. 4,728,571, Clemens et al., issued Mar. 1, 1988. These polymers preferably include copolymers having a vinyl polymeric backbone having grafted onto it monovalent siloxane polymeric moieties, and components consisting of non-silicone hydrophilic and hydrophobic monomers of the type disclosed above including carboxylic acid moieties. The silicone-containing monomers are exemplified by the general formula: X(Y) n Si(R) 3−m Z m wherein X is a polymerizable group, such as a vinyl group, which is part of the backbone of the polymer; Y is a divalent linking group; R is a hydrogen, hydroxyl, lower alkyl (e.g. C 1 -C 4 ), aryl, alkaryl, alkoxy, or alkylamino; Z is a monovalent polymeric siloxane moiety having an average molecular weight of at least about 500, is essentially unreactive under copolymerization conditions, and is pendant from the vinyl polymeric backbone described above; n is 0 or 1; and m is an integer from 1 to 3. The preferred silicone-containing monomer has a weight average molecular weight of from about 1,000 to about 50,000, preferably from about 3,000 to about 40,000, most preferably from about 5,000 to about 20,000. Nonlimiting examples of preferred silicone-containing monomers have the following formulas: In these structures m is an integer from 1 to 3, preferably 1; p is 0 or 1; q is an integer from 2 to 6; n is an integer from 0 to 4, preferably 0 or 1, more preferably 0; 1 is hydrogen, lower alkyl, alkoxy, hydroxyl, aryl, alkylamino, preferably R 1 is alkyl; R″ is alkyl or hydrogen; X is CH(R 3 )══C(R 4 )— R 3 is hydrogen or —COOH, preferably hydrogen; R 4 is hydrogen, methyl or —CH 2 COOH, preferably methyl; Z is R 5 —[Si(R 6 )(R 7 )—O—] r wherein R 5 , R 6 , and R 7 , independently are lower alkyl, alkoxy, alkylamino, hydrogen or hydroxyl, preferably alkyl; and r is an integer of from about 5 to about 700, preferably from about 60 to about 400, more preferably from about 100 to about 300. Most preferably, R 5 , R 6 , and R 7 are methyl, p=0, and q=3. The silicone-containing copolymers preferably have a weight average molecular weight of from about 10,000 to about 1,000,000, preferably from about 30,000 to about 300,000. The preferred polymers comprise a vinyl polymeric backbone, preferably having a Tg or a Tm as defined above of about −20° C. and, grafted to the backbone, a polydimethylsiloxane macromer having a weight average molecular weight of from about 1,000 to about 50,000, preferably from about 5,000 to about 40,000, most preferably from about 7,000 to about 20,000. The polymer is such that when it is formulated into the finished composition, and then dried, the polymer phase separates into a discontinuous phase which includes the polydimethylsiloxane macromer and a continuous phase which includes the backbone. Silicone-containing graft copolymers suitable for the present invention contain hydrophobic monomers, silicone-containing monomers and hydrophilic monomers which comprise unsaturated organic mono- and polycarboxylic acid monomers, such as acrylic acid, methacrylic acid, crotonic acid, maleic acid and its half esters, itaconic acid, and salts thereof, and mixtures thereof. These preferred polymers surprisingly also provide control of certain amine type malodors in fabrics, in addition to providing the fabric wrinkle control benefit. A nonlimiting example of such copolymer is n-butylmethacrylate/acrylic acid/(polydimethylsiloxane macromer, 20,000 approximate molecular weight) copolymer of average molecular weight of about 100,000, and with an approximate monomer weight ratio of about 70/10/20. A highly preferred copolymer is composed of acrylic acid, t-butyl acrylate and silicone-containing monomeric units, preferably with from about 20% to about 90%, preferably from about 30% to about 80%, more preferably from about 50% to about 75% t-butyl acrylate; from about 5% to about 60%, preferably from about 8% to about 45%, more preferably from about 10% to about 30% of acrylic acid; and from about 5% to about 50%, preferably from about 10% to about 40%, more preferably from about 15% to about 30% of polydimethylsiloxane of an average molecular weight of from about 1,000 to about 50,000, preferably from about 5,000 to about 40,000, most preferably from about 7,000 to about 20,000. Nonlimiting examples of acrylic acid/tert-butyl acrylate/polydimethyl siloxane macromer copolymers useful in the present invention, with approximate monomer weight ratio, are: t-butylacrylate/acrylic acid/(polydimethylsiloxane macromer, 10,000 approximate molecular weight) (70/10/20 w/w/w), copolymer of average molecular weight of about 300,000; t-butyl acrylate/acrylic acid/(polydimethylsiloxane macromer, 10,000 approximate molecular weight) (63/20/17), copolymer of average molecular weight of from about 120,000 to about 150,000; and n-butylmethacrylate/acrylic acid/(polydimethylsiloxane macromer—20,000 approximate molecular weight) (70/10/20 w/w/w), copolymer of average molecular weight of about 100,000. A useful and commercially available copolymer of this type is Diahold® ME from Mitsubishi Chemical Corp., which is a t-butyl acrylate/acrylic acid/(polydimethylsiloxane macromer, 12,000 approximate molecular weight) (60/20/20), copolymer of average molecular weight of about 128,000. (2) SILICONE BLOCK COPOLYMERS Also useful herein are silicone block copolymers comprising repeating block units of polysiloxanes, as well as carboxylic acid moieties. The silicone-containing block copolymers useful in the present invention can be described by the formulas A—B, A—B—A, and —(A—B) n — wherein n is an integer of 2 or greater. A—B represents a diblock structure, A—B—A represents a triblock structure, and —(A—B) n — represents a multiblock structure. The block copolymers can comprise mixtures of diblocks, triblocks, and higher multiblock combinations as well as small amounts of homopolymers. The silicone block portion, B, can be represented by the following polymeric structure —(SiR 2 O) m —, wherein each R is independently selected from the group consisting of hydrogen, hydroxyl, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 2 -C 6 alkylamino, styryl, phenyl, C 1 -C 6 alkyl or alkoxy-substituted phenyl, preferably methyl; and m is an integer of about 10 or greater, preferably of about 40 or greater, more preferably of about 60 or greater, and most preferably of about 100 or greater. The non-silicone block, A, comprises carboxylic acid moieties. These polymers can also contain monomers selected from the monomers as described hereinabove in reference to the non-silicone hydrophilic and hydrophobic monomers for the silicone grafted copolymers. The non-silicone block A can contain also comprises amino acids (e.g. including but not limited to cystine as represented by the nonlimiting example Crodasone Cystine® from Croda). When the optional cyclodextrin is present in the composition, the polymer useful in the composition of the present invention should be cyclodextrin-compatible, that is it should not substantially form complexes with cyclodextrin so as to diminish performance of the cyclodextrin and/or the polymer. Complex formation affects both the ability of the cyclodextrin to absorb odors and the ability of the polymer to impart shape retention to fabric. In this case, the monomers having pendant groups that can complex with cyclodextrin are not preferred because they can form complexes with cyclodextrin. Examples of such monomers are acrylic or methacrylic acid esters of C 7 -C 18 alcohols, such as neodecanol, 3-heptanol, benzyl alcohol, 2-octanol, 6-methyl-1-heptanol, 2-ethyl-1-hexanol, 3,5-dimethyl-1-hexanol, 3,5,5-trimethyl-1-hexanol, and 1-decanol; aromatic vinyls, such as styrene; t-butylstyrene; vinyl toluene; and the like. Co-Solvent The preferred co-solvent of the present invention is water. The water which is used can be distilled, deionized, or tap water. Water is the preferred main liquid carrier due to its low cost, availability, safety, and environmental compatibility. Aqueous solutions are preferred for wrinkle control and odor control. Water is very useful for fabric wrinkle removal or reduction. It is believed that water breaks many intrafiber and interfiber hydrogen bonds that keep the fabric in a wrinkle state. It also swells, lubricates and relaxes the fibers to help the wrinkle removal process. Water also serves as the liquid carrier for the cyclodextrins, and facilitates the complexation reaction between the cyclodextrin molecules and any malodorous molecules that are on the fabric when it is treated. The dilute aqueous solution also provides the maximum separation of cyclodextrin molecules on the fabric and thereby maximizes the chance that an odor molecule will interact with a cyclodextrin molecule. It has also been discovered that water has an unexpected odor controlling effect of its own. It has been discovered that the intensity of the odor generated by some polar, low molecular weight organic amines, acids, and mercaptans is reduced when the odor-contaminated fabrics are treated with an aqueous solution. It is believed that water solubilizes and depresses the vapor pressure of these polar, low molecular weight organic molecules, thus reducing their odor intensity. The level of co-solvent in the compositions of the present invention is typically greater than about 0.1%, preferably greater than about 5%, and more preferably greater than about 7%, but no more than 25%, more preferably no more than 15%, and even more preferably no more than 10% by weight of the composition. When a concentrated composition is used, the level of co-solvent is typically equal to or below about 90%, by weight of the composition, preferably equal to or below about 70%, more preferably equal to or below about 50%, even more preferably equal to or below about 30% by weight of the concentrated composition. Carrier The preferred carrier of the present invention is a lipophilic fluid. Lipophilic Fluid The lipophilic fluid herein is one having a liquid phase present under operating conditions of a fabric/leather article treating appliance, in other words, during treatment of a fabric article in accordance with the present invention. In general such a lipophilic fluid can be fully liquid at ambient temperature and pressure, can be an easily melted solid, e.g., one which becomes liquid at temperatures in the range from about 0 deg. C. to about 60 deg. C., or can comprise a mixture of liquid and vapor phases at ambient temperatures and pressures, e.g., at 25 deg C. and 1 atm. pressure. Thus, the lipophilic fluid is not a compressible gas such as carbon dioxide. It is preferred that the lipophilic fluids herein be nonflammable or have relatively high flash points and/or low VOC (volatile organic compound) characteristics, these terms having their conventional meanings as used in the dry cleaning industry, to equal or, preferably, exceed the characteristics of known conventional dry cleaning fluids. Moreover, suitable lipophilic fluids herein are readily flowable and nonviscous. In general, lipophilic fluids herein are required to be fluids capable of at least partially dissolving sebum or body soil as defined in the test hereinafter. Mixtures of lipophilic fluid are also suitable, and provided that the requirements of the Lipophilic Fluid Test, as described below, are met, the lipophilic fluid can include any fraction of dry-cleaning solvents, especially newer types including fluorinated solvents, or perfluorinated amines. Some perfluorinated amines such as perfluorotributylamines while unsuitable for use as lipophilic fluid may be present as one of many possible adjuncts present in the lipophilic fluid-containing composition. Other suitable lipophilic fluids include, but are not limited to, diol solvent systems e.g., higher diols such as C 6 - or C 8 - or higher diols, organosilicone solvents including both cyclic and acyclic types, and the like, and mixtures thereof. A preferred group of nonaqueous lipophilic fluids suitable for incorporation as a major component of the compositions of the present invention include low-volatility nonfluorinated organics, silicones, especially those other than amino functional silicones, and mixtures thereof. Low volatility nonfluorinated organics include for example OLEAN® and other polyol esters, or certain relatively nonvolatile biodegradable mid-chain branched petroleum fractions. Another preferred group of nonaqueous lipophilic fluids suitable for incorporation as a major component of the compositions of the present invention include, but are not limited to, glycol ethers, for example propylene glycol methyl ether, propylene glycol n-propyl ether, propylene glycol t-butyl ether, propylene glycol n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene glycol t-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tripropylene glycol n-propyl ether, tripropylene glycol t-butyl ether, tripropylene glycol n-butyl ether. Suitable silicones for use as a major component, e.g., more than 50%, of the composition include cyclopentasiloxanes, sometimes termed “D5”, and/or linear analogs having approximately similar volatility, optionally complemented by other compatible silicones. Suitable silicones are well known in the literature, see, for example, Kirk Othmer's Encyclopedia of Chemical Technology, and are available from a number of commercial sources, including General Electric, Toshiba Silicone, Bayer, and Dow Corning. Other suitable lipophilic fluids are commercially available from Procter & Gamble or from Dow Chemical and other suppliers. Qualification of Lipophilic Fluid and Lipophilic Fluid Test (LF Test) Any nonaqueous fluid that is both capable of meeting known requirements for a dry-cleaning fluid (e.g, flash point etc.) and is capable of at least partially dissolving sebum, as indicated by the test method described below, is suitable as a lipophilic fluid herein. As a general guideline, perfluorobutylamine (Fluorinert FC-43®) on its own (with or without adjuncts) is a reference material which by definition is unsuitable as a lipophilic fluid for use herein (it is essentially a nonsolvent) while cyclopentasiloxanes have suitable sebum-dissolving properties and dissolves sebum. The following is the method for investigating and qualifying other materials, e.g., other low-viscosity, free-flowing silicones, for use as the lipophilic fluid. The method uses commercially available Crisco® canola oil, oleic acid (95% pure, available from Sigma Aldrich Co.) and squalene (99% pure, available from J. T. Baker) as model soils for sebum. The test materials should be substantially anhydrous and free from any added adjuncts, or other materials during evaluation. Prepare three vials, each vial will contain one type of lipophilic soil. Place 1.0 g of canola oil in the first; in a second vial place 1.0 g of the oleic acid (95%), and in a third and final vial place 1.0 g of the squalene (99.9%). To each vial add 1 g of the fluid to be tested for lipophilicity. Separately mix at room temperature and pressure each vial containing the lipophilic soil and the fluid to be tested for 20 seconds on a standard vortex mixer at maximum setting. Place vials on the bench and allow to settle for 15 minutes at room temperature and pressure. If, upon standing, a clear single phase is formed in any of the vials containing lipophilic soils, then the nonaqueous fluid qualifies as suitable for use as a “lipophilic fluid” in accordance with the present invention. However, if two or more separate layers are formed in all three vials, then the amount of nonaqueous fluid dissolved in the oil phase will need to be further determined before rejecting or accepting the nonaqueous fluid as qualified. In such a case, with a syringe, carefully extract a 200-microliter sample from each layer in each vial. The syringe-extracted layer samples are placed in GC auto sampler vials and subjected to conventional GC analysis after determining the retention time of calibration samples of each of the three models soils and the fluid being tested. If more than 1% of the test fluid by GC, preferably greater, is found to be present in any one of the layers which consists of the oleic acid, canola oil or squalene layer, then the test fluid is also qualified for use as a lipophilic fluid. If needed, the method can be further calibrated using heptacosafluorotributylamine, i.e., Fluorinert FC-43 (fail) and cyclopentasiloxane (pass). A suitable GC is a Hewlett Packard Gas Chromatograph HP5890 Series II equipped with a split/splitless injector and FID. A suitable column used in determining the amount of lipophilic fluid present is a J&W Scientific capillary column DB-1HT, 30 meter, 0.25 mm id, 0.1 um film thickness cat# 1221131. The GC is suitably operated under the following conditions: Carrier Gas: Hydrogen Column Head Pressure: 9 psi Flows: Column Flow @ ˜1.5 ml/min. Split Vent @ ˜250-500 m/min. Septum Purge @ 1 ml/min. Injection: HP 7673 Autosampler, 10 ul syringe, 1 ul injection Injector Temperature: 350° C. Detector Temperature: 380° C. Oven Temperature Program: initial 60° C. hold 1 min. rate 25° C./min. final 380° C. hold 30 min. Preferred lipophilic fluids suitable for use herein can further be qualified for use on the basis of having an excellent garment care profile. Garment care profile testing is well known in the art and involves testing a fluid to be qualified using a wide range of garment or fabric article components, including fabrics, threads and elastics used in seams, etc., and a range of buttons. Preferred lipophilic fluids for use herein have an excellent garment care profile, for example they have a good shrinkage and/or fabric puckering profile and do not appreciably damage plastic buttons. Certain materials which in sebum removal qualify for use as lipophilic fluids, for example ethyl lactate, can be quite objectionable in their tendency to dissolve buttons, and if such a material is to be used in the compositions of the present invention, it will be formulated with water and/or other solvents such that the overall mix is not substantially damaging to buttons. Other lipophilic fluids, D5, for example, meet the garment care requirements quite admirably. Some suitable lipophilic fluids may be found in granted U.S. Pat. Nos. 5,865,852; 5,942,007; 6,042,617; 6,042,618; 6,056,789; 6,059,845; and 6,063,135, which are incorporated herein by reference. Lipophilic fluids can include linear and cyclic polysiloxanes, hydrocarbons and chlorinated hydrocarbons, with the exception of PERC and DF2000 which are explicitly not covered by the lipophilic fluid definition as used herein. More preferred are the linear and cyclic polysiloxanes and hydrocarbons of the glycol ether, acetate ester, lactate ester families. Preferred lipophilic fluids include cyclic siloxanes having a boiling point at 760 mm Hg. of below about 250° C. Specifically preferred cyclic siloxanes for use in this invention are octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. Preferably, the cyclic siloxane comprises decamethylcyclopentasiloxane (D5, pentamer) and is substantially free of octamethylcyclotetrasiloxane (tetramer) and dodecamethylcyclohexasiloxane (hexamer). However, it should be understood that useful cyclic siloxane mixtures might contain, in addition to the preferred cyclic siloxanes, minor amounts of other cyclic siloxanes including octamethylcyclotetrasiloxane and hexamethylcyclotrisiloxane or higher cyclics such as tetradecamethylcycloheptasiloxane. Generally the amount of these other cyclic siloxanes in useful cyclic siloxane mixtures will be less than about 10 percent based on the total weight of the mixture. The industry standard for cyclic siloxane mixtures is that such mixtures comprise less than about 1% by weight of the mixture of octamethylcyclotetrasiloxane. Accordingly, the lipophilic fluid of the present invention preferably comprises more than about 50%, more preferably more than about 75%, even more preferably at least about 90%, most preferably at least about 95% by weight of the lipophilic fluid of decamethylcyclopentasiloxane. Alternatively, the lipophilic fluid may comprise siloxanes which are a mixture of cyclic siloxanes having more than about 50%, preferably more than about 75%, more preferably at least about 90%, most preferably at least about 95% up to about 100% by weight of the mixture of decamethylcyclopentasiloxane and less than about 10%, preferably less than about 5%, more preferably less than about 2%, even more preferably less than about 1%, most preferably less than about 0.5% to about 0% by weight of the mixture of octamethylcyclotetrasiloxane and/or dodecamethylcyclohexasiloxane. The level of lipophilic fluid, when present in the treating compositions according to the present invention, is preferably from about 70% to about 99.99%, more preferably from about 90% to about 99.9%, and even more preferably from about 95% to about 99.8% by weight of the treating composition. The level of lipophilic fluid, when present in the consumable fabric article treating/cleaning compositions according to the present invention, is preferably from about 0.1% to about 90%, more preferably from about 0.5% to about 75%, and even more preferably from about 1% to about 50% by weight of the consumable fabric article treating/cleaning composition. In addition to the above lipophilic solvents, carbon dioxide-philic surfactants can be included in the lipophilic fluid of the present invention. Nonlimiting examples of such carobn dioxide-philic surfactants are described in U.S. Pat. Nos. 5,977,045, 5,683,977, 5,683,473 and 5,676,705. If the lipophilic fluid of the present invention comprises a carbon dioxide-philic surfactant, such surfactant preferably is present at a level of from about 0.001% to about 10% by weight of the lipophilic fluid. Other Solvents and/or Plasticizers Optionally, in addition to lipophilic fluid and co-solvent, the carrier can further comprise solvents and plasticizers that act to aid the natural ability of water to plasticize fibers. Acceptable solvents and plasticizers include compounds having from one to ten carbons. The following non-limiting classes of compounds are suitable: mono-alcohols, diols, polyhydric alcohols, ethers, ketones, esters, organic acids, and alkyl glyceryl ethers, and hydrocarbons. Preferred solvents are soluble in water and/or miscible in the presence of optional surfactant. Some nonlimiting examples include methanol, ethanol, isopropanol, hexanol, 1,2-hexanediol, hexylene glycol, (e.g. 2-methyl-2,4-pentanediol), isopropylene glycol (3-methyl-1,3-butanediol), 1,2-butylene glycol, 2,3-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, isomers of cyclohexanedimethanol, isomers of propanediol, isomers of butanediol, the isomers of trimethylpentanediol, the isomers of ethylmethylpentanediol, alcohol ethoxylates of 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, alcohol ethoxylates of 2,2,4-trimethyl-1,3-pentanediol glycerol, ethylene glycol, diethylene glycol, dipropylene glycol, sorbitol, 3-methyl-3-methoxybutanol, 3-methoxybutanol, 1-ethoxy-2-propanol, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, erythritol, and mixtures of solvents and plasticizers. When optional cyclodextrin is present, the plasticizer should be compatible with it. Mixtures of solvents are also suitable. When solvent is used, it is used typically at a level of at least about 0.5%, preferably at least about 1%, more preferably at least about 2%, even more preferably at least about 3% and still more preferably at least about 4% and typically less than about 30%, preferably less than about 25%, more preferably less than about 20%, even more preferably less than about 15% by weight of the composition. (C) Optional Ingredients In highly preferred compositions, the present low-viscosity polymer composition can also comprise: (1) optional, but highly preferably, silicon, compounds and emulsions, such an Silwet® surfactants; (2) optional supplemental wrinkle control agents selected from, adjunct polymers, fabric care polysaccharides, lithium salts, fiber-fabric lubricants, and mixtures thereof; (3) optional surface tension control agents; (4) optional viscosity control compounds; (5) optional hydrophilic plasticizer (6) optional, but preferable, odor control agent; (7) optional, but preferable, perfume; (8) optional, but preferable, antimicrobial active; (9) optional chelator, e.g., aminoccarboxylate chelator; (10) optional buffer system; (11) optional water-soluble polyionic polymer; (12) optional viscosity control agent; (13) optional antistatic agent; (14) optional insert and moth repellant; (15) optional colorant; (16) optional anti-clogging agent; (17) optional whiteness preservative: and (18) mixtures thereof. The composition of the present invention may also include other optional adjunct ingredients, such an bleaches, emulsifiers, fabric softeners, antibacterial agents, brighteners, dye fixatives, dye abrasion inhibitors, anti-crocking agents, soil release polymers, sunscreen agents, anti-fading agents, water-proofing agents, stain proofing agents, soil repellency agents, and mixtures thereof. Methods The methods of the present invention comprise one or more of the following steps A-E. The steps may occur at any time during the method. Further, each and every step may be independently repeated one or more times. Following the one or more steps A-E, the method may also comprise steps F and/or G. The time to complete the method of the present invention can vary quite widely. For example, the method can take from about 30 seconds to about 30 minutes. More generally, a complete de-wrinkling or fabric treatment operation of fabric articles, from start to end can take from about 5 minutes to about three hours, or even longer. If, for example, a low-energy overnight mode of operation is contemplated or a cleaning operation is to be followed by additional fabric treatment, the method may take several hours. The total processing time will also vary with the precise appliance design. For example, appliance variations having reduced pressure or “vacuum” means can help reduce cycle time. Alternatively, embodiments involving longer times may be less desirable for the consumer but may be imposed by energy-saving requirements varying from country to country. Typical processes include those taking from about 20 minutes to about two hours in total. The balance of process time apart from the various cleaning fluid application stages will typically be dedicated to removal and/or finishing of the fabrics. For example, conventional prespotting, soaking or pretreating may be performed on the fabric articles prior to de-wrinkling them in accordance with the present invention. Further, the method of the present invention may be used for treating an unsorted load of fabric articles without substantial damage or dye-transfer between said articles. By “unsorted fabric articles” it is meant that the fabric articles to be treated comprise two or more articles selected from the group consisting of articles having “dry clean only” care labels. In other words, it is contemplated that the present method be utilized in an apparatus that can clean dry clean only fabrics and fabrics which can be water washed in the same apparatus and at the same time. A. Applying De-Wrinkling Fluid In accordance with the present invention, the de-wrinkling fluid may be applied to the fabric articles by any suitable means known to those skilled in the art. Non-limiting examples of application means include spraying, dipping, brushing on, rubbing on, and the like. A desirable application means comprises spraying. It is desirable that the de-wrinkling fluid is applied such that it uniformly contacts the fabric articles. Such uniformity of de-wrinkling fluid application can be achieved for example by applying a cleaning fluid to fabric articles and then concurrently or subsequently repositioning the fabric articles, such as by tumbling or otherwise moving the fabric articles, to expose non-contacted portions of the fabric articles to the cleaning fluid application or subsequent cleaning fluid application. However, uniformity of distribution is not absolutely necessary, especially for those fabric care agents that can provide their desired benefit to the fabric article without being uniformly distributed on a fabric article. A non-limiting example of such a fabric care agent is a perfume. An effective amount of the de-wrinkling fluid is applied to the fabric articles such that the de-wrinkling fluid provides the desired fabric care benefit to the fabric articles, such as de-wrinkling, conditioning, refreshing, sizing, etc. The application of the de-wrinkling fluid to the fabric articles may be repeated as necessary. Further, the repositioning (i.e., by way of tumbling) of the fabric articles during and/or between applications of the de-wrinkling fluid is desirable. It is acceptable to apply a quantity of de-wrinkling fluid to the fabric articles such that a quantity of lipophilic fluid of from about 20% by dry weight of the fabric articles up to the absorption capacity of the fabric articles is applied to the fabric articles. An important aspect of the present invention is that fabric de-wrinkling or treatment is accomplished with relatively small amounts of de-wrinkling fluid. The amount of de-wrinkling fluid should be just sufficient to completely and uniformly wet the fabric articles. The amount of de-wrinkling fluid needed to uniformly wet fabrics will depend on factors such as the nature of the fibers used in the fabric (whether wool, silk, cotton, polyester, nylon, etc.), the denier of the fiber used in the fabric, the closeness of the weave, etc. For example, the amount of de-wrinkling fluid applied to a fabric article will be at least about 20% by dry weight of the fabric articles, and not more than about 200% by weight of the fabric articles. In many applications an amount of de-wrinkling fluid of from about 75% to about 150% by weight of the fabric articles is preferred, with an amount of about 100% by weight of the fabric articles being particularly preferred. However, it is to be understood that the amount of de-wrinkling fluid applied to a fabric article will vary depending upon the absorption capacity of the fabric articles to be treated. The de-wrinkling fluid comprises from at least about 50% to about 100% by weight of de-wrinkling fluid of a lipophilic fluid and optionally from about 0% to about 50% by weight of de-wrinkling fluid of an adjunct ingredient. The de-wrinkling fluid can comprise one or more liquid phases and can be in the form of an emulsion or micro-emulsion form. The lipophilic fluid and adjunct ingredients will now be explained in more detail. The total amount of de-wrinkling fluid used in one treatment cycle, that is the total amount of de-wrinkling fluid applied to and removed from the fabric articles in the process of the present invention from the time the process is commenced until it is finished is from about 10% to about 1500%, even more preferably from about 10% to about 500%, even more preferably from about 10% to about 250%, even more preferably from about 30% to about 150%, even more preferably from about 80% to about 130%, even more preferably still from about 100% to about 120% by weight of the dry fabric articles. One suitable cleaning fluid composition comprises about 85% to 90% by weight of lipophilic fluid, preferably a silicone, such as cyclopentasiloxane, and from about 15% to about 10% of adjunct ingredients. Since the “absorption capacity” of different fabric articles vary, the amount of de-wrinkling fluid used with the different fabric articles can vary. For example, for fabric articles that have a greater absorption capacity, more de-wrinkling fluid and thus, more lipophilic fluid can be used. Non-limiting examples of absorption capacities of fabric articles are described below: Sample Table for Fabric Absorbency Fabric Type Structure Average absorbency, % Cotton, C61 Mesh 165 Cotton, C77 Knit 330 Cotton, CW19 Towel 480 Polycotton, PC49 Knit 170 Polycotton, BC Corduroy 200 Polyester, PW18 knit 240 Wool, W4 knit 330 Wool, W522 knit 250 Acrylate, ACR8 knit 340 Nylon, N18 knit 210 Nylon, N21 knit 140 Silk knit 190 (Absorbency of fabrics determined using the Test Protocol for Measuring Absorption Capacity of a Fabric Article as described hereinabove.) The amount of lipophilic fluid evenly distributed onto the fabric article(s) will depend on a wide range of factors, such as, type of fluid, its affinity to fabrics, garment construction, wrinkle amount to be removed, etc. For example, typically, fine, thin garments will require lesser amount of de-wrinkling fluid than heavier garments. However, the quantity of lipophilic fluid is such, that there is none or minimal amounts of lipophilic fluid in excess of the absorption capacity of the fabric article(s) being treated, which is typically about 150%, by dry weight of the fabric article(s). Typically, in a domestic situation the amount of lipophilic fluid is based on weight, type of garments, wrinkle amount, and can be controlled by user-selectable interface choosing the most appropriate cycle, much in the same fashion as a consumer would on a conventional washing machine. B. Mechanically Removing Cleaning Fluid In accordance with the present invention, lipophilic fluid present on the fabric articles does not need to be mechanically removed. It is desirable to remove the de-wrinkling fluid by other means to avoid additional mechanical forces that may cause crease formation. Nonlimiting examples of forces that can produce creases include squeezing, pressing, or otherwise flattening the fabric articles. C. Evaporatively Removing Cleaning Fluid The lipophilic fluid present on the fabric articles may be evaporatively removed. The amount of lipophilic fluid evaporatively removed varies depending on the quantity of lipophilic fluid present on the fabric articles, other materials in addition to the lipophilic fluid present on the fabric articles, the type of fabric articles, and the like. Evaporatively removing the lipophilic fluid from the fabric articles is a desirable way to remove a quantity of lipophilic fluid that remains on the fabric articles after the application step. The evaporative removal step can be considered a “drying” step. The purpose of the evaporative removal step is to remove a quantity of lipophilic fluid from the fabric articles such that the fabric articles are “dry to the touch”. Physical conditions and/or chemical agents/conditions may be used to facilitate the evaporative removal of the lipophilic fluid. For example, drying aids (i.e., any chemical agent that evaporates more readily than the lipophilic fluid used in the method that reduce the time for drying of the fabric articles treated in the method of the present invention). Non-limiting examples of such drying aids include alcohols, hydrofluoroethers, esters and mixtures thereof. Additional conditions that can be used to reduce the time for drying of the fabric articles include, but are not limited to, contacting the fabric articles with heated gas and/or circulating gas, and/or repositioning the fabric articles during the evaporative removal step. The heated gas may be air, or may be an inert gas such as nitrogen, depending on the cleaning fluid being evaporatively removed. This step may be carried out at atmospheric pressure or at a reduced pressure. Operating at a reduced pressure permits evaporative removal at a lower temperature. It is desirable to select conditions (gas temperature, pressure, flow rate) such that the evaporative removal step be completed in less than an hour, preferably in less than 45 minutes. Upon the completion of the evaporative removal step the fabric articles will be ready for their intended use. D. Contacting with Impinging Gas In accordance with the present invention, the fabric articles to be treated and/or cleaned may be contacted with an impinging gas at any time during the method of the present invention. It is desirable that an impinging gas contacts the fabric articles at least prior to applying the de-wrinkling fluid. The impinging gas facilitates the removal particulate soils from the fabric articles. Particulate soils can be successfully removed using gas flow. Particulate soils include any soil that is comprised of discrete particles. Nonlimiting examples of such particulate soils include clay, dust, dried mud, sand, cat fur, skin flakes or scales, dander, dandruff, hair from people or pets, grass seeds, pollen, burrs, and/or similar animal, mineral or vegetable matter which is insoluble in water. By utilizing the impinging gas, “demand” on chemicals in the process for removing such particulate soils is reduced. Typically, the impinging gas is flow from a gas source at a rate of from about 10 l/s to about 70 l/s and the gas contacts the fabric articles at a velocity of from about 1 m/s to about 155 m/s. It is desirable to mechanically agitate the fabric articles while the gas impinges on the fabric articles. Further, it is desirable to remove the gas, and particulate soils in the gas from the fabric articles at a rate sufficient to prevent the removed particulate soils from re-depositing upon the fabric articles. In one embodiment of the present invention the gas is selected from the group consisting of air, nitrogen, ozone, oxygen, argon, helium, neon, xenon, and mixtures thereof, more preferably air, nitrogen, ozone, oxygen, argon, helium, and mixtures thereof, even more preferably still air, ozone, nitrogen, and mixtures thereof. In another embodiment of the present invention the gas used in the method can be varied over time. For example air could be used at the start of the process, a mixture of air and ozone used in the middle stages of the process and air or nitrogen could be used at the end. The gas used may be of any suitable temperature or humidity. Heat could be supplied to the gas electrically or by passing the gas over a gas flame, such as, is done in a conventional gas dryer. However, room temperature and humidity gas are preferred. In one embodiment of the present invention two or more gases could be mixed in a mixing chamber before being used in the process. In another aspect of this embodiment of the present invention the gases could be delivered concurrently through different entry points and mix in-situ in the walled vessel. In another aspect of this embodiment of the present invention the gases supplied could exist as mixture and would not require any mixing chamber to achieve the required mixture of gas for the process. In one embodiment of the present invention the gas could be available from storage, such as from pressurized containers. Alternatively, the gas used in the process could be obtained from the location where the process and device occur. For example, a pump, blower, or the like, may be used to supply air from the surrounding atmosphere for the process of the invention. A combination of gas available from storage and from the atmosphere is also envisioned. In another embodiment of the present invention the gas can be obtained from a compressor. The compressor may be any compressor suitable for providing gas or gases, provided that they supply the gas to the apparatus within the required velocity and flow rate ranges. The compressors are linked to the gas inlet(s) by an appropriate fixture, such as a hose, pipe, tap, fixture or combinations thereof, to provide the inlet(s) with the gas or gases within the required velocity and flow rate ranges. Some typical compressors, which are suitable for providing gas or gases, include rotary screw compressors or two-stage electrical compressor. Another suitable type of compressor is the so-called “acoustical compressor”, such as those described in U.S. Pat. Nos. 5,020,977, 5,051,066, 5,167,124, 5,319,938, 5,515,684, 5,231,337, and 5,357,757, all of which are incorporated herein by reference. Typically, an acoustical compressor operates in the following fashion: A gas is drawn into a pulse chamber, such as air from the atmosphere, compressed, and then discharged as a high-pressure gas. The gas is compressed by the compressor sweeping a localized region of electromagnetic, for example microwaves, laser, infrared, radio etc, or ultrasonic energy through the gas in the pulse chamber at the speed of sound. This sweeping of the pulse chamber creates and maintain a high-pressure acoustic pulse in the gas. These acoustical compressors have many advantages over conventional compressors. For example, they have no moving parts besides the valves, operate without oil, and are much smaller than comparable conventional compressors. In one embodiment of the present invention the gas is provided from a gas source at a rate of from about 10 l/s to about 70 l/s, more preferably, about 20 l/s to about 42 l/s, even more preferably about 25 l/s to about 30 l/s. The gas flow rate is measure by a flow meter place in the internal space of the vessel close to where the gas enters the vessel containing the clothes. In one embodiment of the present invention the gas contacts the fabric articles at a velocity of from about 1 m/s to about 155 m/s, more preferably, about 50 m/s to about 105 m/s even more preferably about 75 m/s to about 105 m/s. The gas velocity is measure by a flow meter place in the internal space of the vessel close to where the gas enters the vessel containing the clothes. The velocity at which the gas contacts the fabric articles and the flow rate of the gas are critical parameters. For example insufficient velocity, means that the particulates are not removed from the fabric articles. Too great a velocity and the fabric articles are disrupted such that the fabric articles cannot be agitated and the particulate soils cannot be removed. Similarly, insufficient flow rate of the gas means that any particulate soils removed remain and can be re-deposited on the fabric article after cleaning. E. Applying Finishing Agent-Contacting Composition In accordance with the present invention, a finishing agent-containing composition may be applied to the fabric articles. It is desirable that the application of the finishing agent-containing composition to the fabric articles occurs after the mechanical removal step. Further, it is desirable that the application of the finishing agent-containing composition occurs prior to any evaporative removal step. The purpose of the finishing agent-containing composition is to apply a finishing agent to the fabric articles such that the finishing agent remains on the fabric articles after the method of the present invention. The finishing agent-containing composition may be applied to the fabric articles at any amount. The quantity of finishing agent-containing composition applied to the fabric articles depends upon the type of fabric articles, the purpose of the finishing agent (i.e., sizing, perfuming, softening, deodorizing). Typically, a quantity of the finishing agent-containing composition of from about 0.1% to about 100%, more typically from about 0.5% to about 50%, most typically from about 1% to about 10% by dry weight of the fabric articles is applied to the fabric articles. Depending upon the finishing agent and its purpose, the finishing agent-containing composition may be applied uniformly to the fabric articles. The finishing agent-containing composition typically comprises a finishing agent selected from the group consisting of: fabric softening agents or actives, perfumes, hand-modifying agents, properfumes, fabric softening agents or actives, anti-static agents, sizing agents, optical brighteners, odor control agents, soil release polymers, hand-modifying agents, insect and/or moth repellent agents, antimicrobial agents, odor neutralizing agents and mixtures thereof. The fabric softening agents or actives typically comprise a cationic moiety, more typically a quaternary ammonium salt, preferably selected from the group consisting of: N,N-dimethyl-N,N-di(tallowyloxyethyl) ammonium methylsulfate, N-methyl-N-hydroxyethyl-N,N-di(canoyloxyethyl) ammonium methylsulfate and mixtures thereof. The hand-modifying agents typically comprise a polyethylene polymer. One especially preferred finishing agent-containing composition comprises a mix of DPGDME (DiPropyleneGlycol DiMethylEther) N,N-di(tallowoyl-oxy-ethyl)-N,N-dimethyl ammonium chloride and a perfume. F. Collecting Lipophilic Fluid The lipophilic fluid removed from the fabric articles may be collected by any suitable means known to those in the art. The collected lipophilic fluid may be reused at a later time or may be stored until proper removal of the lipophilic fluid is arranged. G. Reusing Lipophilic Fluid The lipophilic fluid removed from the fabric articles may be reused. It is desirable that any soils present in the lipophilic fluid are removed prior to reapplying the lipophilic fluid to the fabric articles. For the lipophilic fluid to be reused, it is desirable that the lipophilic fluid is processed to remove any soils as well as any water that are present in the lipophilic fluid. Nonlimiting examples of processing steps include filtering the lipophilic fluid, such as through an absorbent material, preferably an absorbent material that releasably captures water from the lipophilic fluid, other separation and/or filtering techniques, such as exposing the lipophilic fluid to an electric field.

Compositions and methods for wrinkle reduction in fabrics, including washable clothes, dry cleanable clothes, linens, bed clothes, draperies, window curtains, shower curtains, table linens, and the like requiring little, if any, pressing, ironing, and/or steaming are disclosed.

BACKGROUND OF THE INVENTION (a) Field of the Invention This invention relates to novel tetrahydrocarbazole derivatives, to a process and to intermediates for preparing the derivatives, to methods for using the derivatives and to compositions and therapeutically acceptable salts of the derivatives. More specifically, the present invention relates to novel 1,2,3,4-tetrahydrocarbazole and 1,2,3,4-tetrahydrocyclopent[b]indole derivatives having a hydroxyalkanamine group. These derivatives are useful as diuretic agents in a mammal at dosages which do not elicit undesirable side effects. The combination of these attributes render the 1-hydroxyalkanamine tetrahydrocarbazole derivatives of this invention therapeutically useful. The 1-hydroxyalkanamine tetrahydrocarbazole derivatives of this invention belong to a special class of diuretic agents which antagonize the renal effects of mineralocorticoids. As a result, these compounds are useful in treating hyperaldosteronism by increasing urine volume and sodium and chloride excretion without affecting potassium excretion. Also, these compounds find utility in the treatment of edema and hypertension. (b) Description of the Prior Art A number of reports dealing with tetrahydrocarbazole derivatives are available. For instance, a number of these derivatives are reported by C. A. Demerson et al., in U.S. Pat. No. 3,843,681, issued Oct. 22, 1974; C. A. Demerson et al., in U.S. Pat. No. 3,880,853, issued Apr. 29, 1975; Dostert et al., U.S. Pat. No. 3,859,304, issued Jan. 7, 1975 and A. A. Asselin et al., U.S. Pat. No. 4,128,560, issued Dec. 5, 1978. The compounds of the present invention are distinguished from the compounds of the above prior art by the nature of the substituents on the tetrahydrocarbazole nucleus and by their pharmacologic properties. More specifically, the novel compounds of this invention are distinguished from the prior art compounds by having a hydroxyalkanamine group. In addition, the novel 1-hydroxyalkanamine tetracarbazole derivatives of this invention possess useful diuretic activity in mammals, a pharmacologic activity not previously reported for tetracarbazole derivatives. Asselin et al., application Ser. No. 904,081, filed May 8, 1978, now Pat. No. 4,179,503, shows 1,3,4,9-tetrahydropyrano[3,4-b]indole and 1,3,4,9-tetrahydrothiopyrano[3,4-b]-indole derivatives having a hydroxyalkanamine and a lower alkyl group at position 1. The compounds of the present invention are distinguished therefrom in having a different ring structure. SUMMARY OF THE INVENTION The compounds of this invention are represented by formula I ##STR1## in which R 1 and R 2 each is hydrogen or lower alkyl; R 3 and R 4 each is hydrogen, lower alkyl, halo, nitro, trifluoromethyl or lower alkoxy; R 5 and R 6 each is hydrogen or lower alkyl or R 5 and R 6 together with the nitrogen atom to which they are attached form a pyrrol-1-yl, piperidin-1-yl or morpholin-4-yl; m is 2 or 3; and n is 1 or 2; or a therapeutically acceptable acid addition salt thereof. A preferred group of compounds of this invention is represented by formula I in which R 1 and R 2 each is hydrogen or lower alkyl; R 3 and R 4 each is hydrogen, lower alkyl or halo; R 5 and R 6 each is hydrogen or lower alkyl; m is 2 or 3; and n is 1 or 2. A more preferred group of compounds of this invention is represented by formula I in which R 1 is hydrogen or lower alkyl; R 2 , R 3 and R 4 are hydrogen; R 5 and R 6 each is hydrogen or lower alkyl; m is 2 or 3; and n is 2. A most preferred group of compounds of this invention is represented by formula I in which R 1 , R 5 and R 6 each is lower alkyl; R 2 , R 3 and R 4 are hydrogen; and m and n are 2. A compound of formula I or a therapeutically acceptable acid addition salt thereof increases the excretion of urine (diuresis) in a mammal, antagonizes renal mineralocorticoids in a mammal, increases the excretion of urine in a mammal without excessive loss of potassium, reverses or prevents secondary aldosteronism and potassium depletion induced in a mammal undergoing diuretic therapy, and is useful for treating hypertension. A pharmaceutical composition is provided by combining a compound of formula I, or a therapeutically acceptable salt thereof, with a pharmaceutically acceptable carrier. In addition, a compound of formula I, or a therapeutically acceptable salt thereof, in combination with a non-mineralocorticoid antagonizing diuretic agent and a pharmaceutically acceptable carrier forms a pharmaceutical composition. The compounds of formula I in which R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , m and n are as defined herein are prepared by a process, which comprises reacting a compound of formula II in which R 1 ,R 2 ,R 3 ,R 4 ,m and n ##STR2## are as defined herein with an amine of formula HNR 5 R 6 in which R 5 and R 6 are as defined herein to obtain the corresponding compound of formula III ##STR3## in which R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 ,m and n are as defined herein, and reducing the compound of formula III with a complex metal hydride. DETAILED DESCRIPTION OF THE INVENTION The term "lower alkyl" as used herein means straight chain alkyl radicals containing from one to six carbon atoms and branched chain alkyl radicals containing from three to four carbon atoms and includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl and the like. The term "lower alkoxy" as used herein means straight chain alkoxy radicals containing from one to six carbon atoms and branched chain alkoxy radicals containing three or four carbon atoms and includes methoxy, ethoxy, isopropoxy, butoxy, hexanoxy and the like. The term "halo" as used herein means halogens and includes fluorine, chlorine, bromine and iodine, unless stated otherwise. The term "complex metal hydride" as used herein means the metal hydrides, including lithium aluminum hydride, lithium aluminum hydride-aluminum chloride, aluminum hydride-aluminum chloride, borane, borane-methyl sulfide, sodium borohydride-aluminum chloride, diisobutylaluminum hydride and the like. The compounds of this invention are capable of forming acid addition salts with therapeutically acceptable acids. The acid addition salts are prepared by reacting the base form of the appropriate compound of formula I with one or more equivalents, preferably with an excess, of the appropriate acid in an organic solvent, for example, diethyl ether or an ethanol-diethyl ether mixture. These salts, when administered to a mammal, possess the same pharmacologic activities as the corresponding bases. For many purposes it is preferable to administer the salts rather than the base compounds. Suitable acids to form these salts include the common mineral acids, e.g. hydrohalic, sulfuric or phosphoric acid, the organic acids, e.g. maleic, citric, or tartaric acid, and acids which are sparingly soluble in body fluids and which impart slow-release properties to their respective salts, e.g. pamoic or tannic acid or carboxymethyl cellulose. The addition salts thus obtained are the functional equivalent of the parent base compound in respect to their therapeutic use. Hence, these addition salts are included within the scope of this invention and are limited only by the requirement that the acids employed in forming the salts be therapeutically acceptable. Also included in this invention are the stereochemical isomers of the compounds of formula I which result from asymmetric centers obtained therein. Such stereochemical isomers are obtained in substantially pure form by classical separation techniques and by sterically controlled synthesis and have arbitrarily been named as isomers A and B, respectively. Individual optical enantiomers, which might be separated by fractional crystallization of the diastereomeric salts thereof, for instance, salts with d- or 1-tartaric acid or D-(+)-α-bromocamphor sulfonic acid, are also included. The compounds of this invention of formula I or a therapeutically acceptable salt thereof are useful diuretic agents in a mammal upon oral or parenteral administration. The compounds of formula I are shown to be effective diuretic agents in mammals by tests conducted in dogs or rats. An example of such a test for diuretic agents in rats is described by J. R. Cummings et al., J. Pharmacol. Exp. Ther., 414, 128 (1960). In this test, the urine of the rats is collected for five hours, during which time food and water are withdrawn. Urine volumes as well as sodium, potassium and chloride ion concentrations are determined. In this test, the compounds of this invention exhibit a dose-response dependency when they are orally administered in dosages ranging from 50 to 300 mg per kilogram of body weight. For example, the following representative compounds of formula I are effective diuretic agents when administered to the rat (the effective oral dose in mg per kilogram of body weight to obtain a three fold increase in urine volume and/or electrolyte concentration is indicated within the parentheses): isomer A of γ-[(dimethylamino)-methyl]-1-methyl-1,2,3,4-tetrahydrocarbazole-1-propanol(100 mg, described in Example 1) and isomer B of γ-[(dimethylamino)methyl]-1-methyl-1,2,3,4 -tetrahydrocarbazole-1-propanol (100 mg, described in Example 1). In addition to the above test for diuretic activity, the compounds of formula I antagonize the renal actions of mineralocorticoids and thus cause an increase in sodium and chloride excretion without affecting potassium excretion. Aldosterone is a naturally occurring mineralocorticoid of the adrenal cortex which promotes the reabsorption of sodium and chloride and the excretion of potassium, hydrogen and ammonium ions in the distal renal tubules. Hyperaldosteronism is found in a number of pathological conditions. Hyperaldosteronism can be corrected by the administration of a diuretic agent which antagonizes the renal action of aldosterone. Antialdosterone activity can be demonstrated in standard test systems. One such test is described by C. M. Kagawa et al., J. Pharm. Exp. Ther., 126, 123 (1959). In this test male albino rats (140-160 g) are kept under laboratory conditions for four days, after which they are bilaterally adrenalectomized under diethyl ether anesthesia. The animals are then maintained for 48 hours on a diet of Purina Rat Chow and 5% (W/V) glucose solution (ad libitum). Prior to the test the animals are starved for eighteen hours, but are allowed access to the 5% (W/V) glucose solution. Each rat then receives a single subcutaneous injection of physiological saline (2.5 ml) followed by a subcutaneous injection of desoxycorticosterone acetate (DOCA, 12.5 mcg per rat). The test compound is administered orally. The rats are placed in metabolism cages and the urine is collected for four hours. Urine volume and urinary sodium, potassium and chloride are measured. In this test the compounds of this invention are effective by showing a dose response dependency in the range of 3 to 100 mg/kg of body weight. More specifically, this test shows that the following representative compounds of formula I are effective diuretic agents by increasing the urine volume and sodium and chloride excretion when administered to the rat (the effective oral dose in mg per kilogram of body weight to obtain a statistically significant increase in urine volume and sodium and chloride concentration is indicated in the parenthesis): isomer A of γ-[(dimethylamino)methyl]-1-methyl-1,2,3,4-tetrahydrocarbazole-1-propanol (6.25 mg, described in Example 1) and isomer B of γ-[(dimethylamino)methyl]-1-methyl-1,2,3,4-tetrahydrocarbazole-1-propanol (50 mg, described in Example 1). Another test for antialdosterone diuretic activity, described by C. M. Kagawa et al., Arch. Pharmacodyn. Ther., 149, 8 (1964) can be conducted in intact female dogs. The dogs are given 0.25 mg of DOCA in 0.25 ml of sesame oil intramuscularly and the test drug orally by capsule two hours before the beginning of infusion. A retention catheter is placed in the bladder for urine collection, and the cephalic vein is cannulated for infusion. Saline, 0.45%, plus dextrose, 5%, is unfused intravenously at a rate of 1 ml/kg/min for 20 minutes, after which the rate is reduced to 0.3 ml/kg/min for the duration of the experiment. Urine is collected at 30 minute intervals, the urine volumes are recorded, and samples are taken. Collections are continued for five 30 minute periods. The urine samples are analyzed and the urinary Na/K ratios are calculated. By using this test, the compounds of formula I can be shown to be effective diuretic agents by increasing urine volume and sodium and chloride excretion when administered to the dog. The compounds of formula I can be administered to a mammal in a combination with a therapeutically effective dose of a diuretic agent, acting by another mechanism. These latter diuretics, non-renal mineralocorticoid antagonizing diuretics, cause loss of water as well as the electrolytes sodium, potassium, etc. Suitable diuretics for this combination, together with their daily dosage, are set out below: ______________________________________ Recommended daily humanDiuretic dosage range (mg/70 Kg)______________________________________hydrochlorothiazide 25-100chlorothiazide 500-1000chlorthalidone 50-200ethacrynic acid 50-200furosemide 40-80quinethazone 50-100bumetanide 1-2______________________________________ The following method illustrates that the combination of the compound of formula I with a diuretic agent can result in a useful reduction of potassium excretion. Male albino Sprague-Dawley rats weighing 180 to 200 g are divided into four groups of seven rats each. At the beginning of the test the bladder of each rat is emptied by gentle suprapubic pressure. The required dose of the compound of formula I and/or diuretic agent is suspended in 2% (W/V) starch solution and administered orally. The control group receives the vehicle only. Each rat receives 5 ml of 0.9% sodium chloride per 100.0 gram of body weight orally. The rats are placed in individual metabolism cages and urine is collected for five hours after which the bladder is again emptied by gentle suprapubic pressure. All urine samples are analyzed for Na, K and Cl content and Na/K ratios are calculated. The combination of a compound of formula I with other diuretic agents is useful for treating certain disease states, for instance, secondary hyperaldosteronism, as a result of pathologic conditions such as ascites due to cirrhosis of the liver. In addition, the use of a compound of formula I, given sequentially or simultaneously, in combination with another diuretic agent can allow the reduction of the usual therapeutic dose of the other diuretic and still cause sufficient sodium excretion without excessive potassium loss. The above described test methods for diuretic activity illustrate that the diuretic effect of the compounds of formula I is primarily due to the antagonism of mineralocorticoids on renal electrolyte excretion and in part results from an additional direct renal tubular effect. From the above test methods, the compounds of formula I exhibit a separation of diuretic and antialdosterone diuretic activities by possessing effective antialdosterone diuretic activity at lower doses than required for effective diuretic activity. Furthermore, the compounds of formula I, when tested as described above, are non-toxic when administered in effective diuretic and antialdosterone diuretic amounts. In addition, since the compounds of formula I are non-steroidal, the compounds of formula I do not exhibit the undesirable side effects of steroidal antagonists of mineralocorticoids. Such common side effects of steroidal antagonists are gynecomastia, impotence and irregular menses. In addition to their use as diuretic agents, the compounds of formula I or a therapeutically acceptable acid addition salt thereof are useful agents for the treatment of hypertension in a mammal. For the treatment of hypertension in a mammal, the compounds of formula I are administered in the same manner as described herein for their use as diuretic agents. When used for the treatment of hypertension, the compound of formula I can be administered alone or administered sequentially or simultaneously in combination with an effective amount of a non-mineralocorticoid antagonizing diuretic agent. Furthermore, a combination of an antihypertensive effective amount of an antihypertensive agent with the compound of formula I, or a therapeutically acceptable acid addition salt thereof; or a combination of an antihypertensive effective amount of an antihypertensive agent with the compound of formula I, or a therapeutically acceptable acid addition salt thereof, and an effective amount of a non-mineralocorticoid antagonizing diuretic agent is useful for the treatment of hypertension in a mammal. Suitable antihypertensive agents for use in this combination can be selected from Rauwolfia and related alkaloids e.g. reserpine, syrosingopine, deserpidine, rescinnamine; guanethidines, e.g. guanethidine, 2-heptamethylineimino-ethylguanidine or related guanidines covered in U.S. Pat. No. 2,928,829 by R. P. Mull, issued Mar. 15, 1960, herein incorporated by reference; veratrum alkaloids, e.g. protoveratrines A and B or germine; hydralazine; diazoxide; minoxidil; nitroprusside, phentolamine; phenoxybenzamine; pargyline; chlorisondamine, hexamethonium, mecamylamine, pentoliniuim; trimethaphan; clonidine; methyldopa; and propranolol. A combination of antihypertensive agents, for example reserpine and hydralazine, can be substituted for a single antihypertensive agent, as described above. Suitable methods of administration, compositions and dosages of the above described antihypertensive agents are described in medical textbooks, for instance, see Charles E. Baker, Jr. "Physician's Desk Reference", Medical Economics Company, Oradell, N.J., 1977. For example, the antihypertensive agent propranolol is administered orally as propranolol hydrochloride (INDERAL, "Inderal" is a trade mark) to humans in the effective dose range of 80 to 640 mg per day. The compounds of formula I, when administered in combination with an antihypertensive agent or an antihypertensive agent plus a non-mineralocorticoid antagonizing diuretic agent for the treatment of hypertension, are used in the same manner as described herein for their use as diuretic agents. When the compounds of formula I of this invention are used as diuretic and/or antialdosterone agents in mammals, e.g. rats and dogs, they are used alone or in combination with pharmacologically acceptable carriers, the proportion of which is determined by the solubility and chemical nature of the compound, chosen route of administration and standard biological practice. For example, they are administered orally in solid form i.e. capsule or tablet. They are also administered orally in the form of suspensions or solutions or be used in the form of a sterile solution containing other solutes, for example, enough saline or glucose to make the solution isotonic. The tablet compositions contain the active ingredient in admixture with non-toxic pharmaceutical excipients known to be suitable in the manufacture of tablets. Suitable pharmaceutical excipients are, for example, starch, milk sugar, certain types of clay and so forth. The tablets can be uncoated or they can be coated by known techniques so as to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. The aqueous suspensions of the compounds of the invention contain the active ingredient in admixture with one or more non-toxic pharmaceutical excipients known to be suitable in the manufacture of aqueous suspensions. Suitable excipients are, for example, methyl-cellulose, sodium alginate, gum acacia, lecithin and so forth. The aqueous suspension can also contain one or more preservatives, one or more colouring agents and/or one or more sweetening agents. Non-aqueous suspensions can be formulated by suspending the active ingredient in a vegetable oil, for example, arachis oil, olive oil, sesame oil, or coconut oil; or in a mineral oil. The suspension can contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. These compositions can also contain a sweetening agent, flavouring agent and antioxidant. The dosage of the compounds of formula I of this invention as diuretic and antialdosterone agents will vary with the form of administration and the particular host as well as the age and condition of the host under treatment. Generally, treatment is initiated with small dosages substantially less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstances is reached. In general, the compounds of this invention are most desirably administered at a concentration level that will generally afford effective results without causing any harmful or deleterious side effects. The effective diuretic and antialdosterone amount of the compounds usually ranges from about 0.5 mg to about 500 mg per kilogram of body weight per day, although as aforementioned variations will occur. However a dosage level that is in the range of from about 2 mg to about 300 mg per kilogram of body weight per day is employed most desirably in order to achieve effective results. PROCESS The process for the preparation of the compounds of formula I is illustrated in reaction scheme 1. ##STR4## With reference to reaction scheme 1, a compound of formula II in which R 1 ,R 2 ,R 3 ,R 4 , m and n are as defined herein is reacted with 20 to 40 molar equivalents of an amine of formula HNR 5 R 6 in which R 5 and R 6 are as defined herein in an inert organic solvent, preferably methanol, tetrahydrofuran or dioxane, at 50° to 80° C. for two to ten days to obtain the corresponding amide of formula III in which R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , m and n are as defined herein. The amide of formula III is reduced with a complex metal hydride to obtain the corresponding compound of formula I in which R 1 ,R 2 ,R 3 ,R 4 ,R 5 ,R 6 , m and n are as defined herein. Examples of suitable complex metal hydrides are lithium aluminum hydride, lithium aluminum hydride-aluminum chloride, aluminum hydride-aluminum chloride, diborane, diisobutylaluminum hydride, borane-methyl sulfide and sodium borohydride-aluminum chloride. Lithium aluminum hydride or diisobutylaluminum hydride is preferred. Preferred inert solvents for use with the complex metal hydrides are the nonhydroxylic solvents, for example, diethyl ether, dioxane, tetrahydrofuran, 1,2-dimethoxyethane and the like. The choice of solvent will depend on solubility of reactants and temperature required for reduction. Usually the reduction is conducted at 0° to 100° C., preferably 30° to 70° C., for one to ten hours. The preferred amount of complex metal hydride is in the range of two to ten molar equivalents. A method of preparing the compounds of formula II is illustrated in reaction scheme 2. ##STR5## As illustrated in reaction scheme 2, an indole derivative of formula IV in which R 2 ,R 3 ,R 4 and n are as defined herein is condensed with about one molar equivalent of a keto-ester of formula V in which R 1 is as defined herein and Alk is lower alkyl in the presence of about one molar equivalent of sodium hydride in tetrahydrofuran at about 40° to 70° C. for 10 to 40 hours to obtain the corresponding compound of formula VI in which R 1 ,R 2 ,R 3 ,R 4 , n and Alk are as defined herein. Decarboxylation of the compound of formula VI with about 1.5 to 2.0 molar equivalents of barium hydroxide in aqueous ethanol at 60° to 90° C. for 10 to 30 hours followed by acidification of the reaction mixture with dilute hydrochloric acid gives the corresponding compound of formula VII in which R 1 ,R 2 ,R 3 ,R 4 and n are as defined herein. In the next step, the anion of the lactone of formula VIII in which m is as defined herein is first prepared by reacting diisopropylamine with about one molar equivalent of butyllithium in anhydrous tetrahydrofuran at about 0° to 5° C. for 10 to 20 minutes and about one molar equivalent of the lactone of formula VIII is added, the resulting solution is stirred at -50° to -78° C. for 10 to 20 minutes to give a solution containing the anion of the lactone of formula VIII. To this solution is added a solution of about one-half molar equivalent of the compound of formula VII in a solvent consisting of hexamethylphosphoric triamide and tetrahydrofuran, and the resulting solution is maintained at about -30° to -50° C. for 30 to 60 minutes to obtain the corresponding compound of formula IX in which R 1 ,R 2 ,R 3 ,R 4 , m and n are as defined herein. Cyclization of the compound of formula IX with 5 to 20 molar equivalents of boron trifluoride etherate at 100° to 130° C. for 30 minutes to two hours gives the corresponding compound of formula II in which R 1 ,R 2 ,R 3 ,R 4 , m and n are as defined herein. The above described series of reactions as illustrated in reaction scheme 2 is especially useful for preparing the compounds of formula II in which R 1 ,R 2 ,R 3 and R 4 are as defined herein, and m and n are 2. Another method of preparing the compounds of formula II is illustrated in reaction scheme 3, wherein a keto-ester of formula X in which R 1 and n are as defined herein and Alk is lower alkyl is reacted with about one molar equivalent of trimethylorthoformate in the presence of a catalytic amount of concentrated sulfuric acid in anhydrous methanol at 60° to 70° C. for two to seven hours to obtain the corresponding compound of formula XI in which R 1 , n and Alk are as defined herein. ##STR6## Alkylation of the compound of formula XI affords the corresponding compound of formula XII in which R 1 , m, n and Alk are as defined herein. This alkylation is readily achieved by the following steps: a solution of diisopropylamine and about one molar equivalent of butyllithium in a mixture of tetrahydrofuran and hexane is stirred at 0° to 5° C. for about 15 minutes and cooled to -50° to -78° C.; about one molar equivalent of the compound of formula XI is added and the resulting mixture is stirred at -50° to -78° C. for 30 minutes to two hours; a solution of about one molar equivalent of 3-bromo-1-propene or 4-bromo-1-butene in a solvent of hexamethylphosphoric triamide is added and the resulting solution is stirred at about -50° to -78° C. for 30 minutes to two hours and at 20° to 30° C. for 20 to 30 hours; and the compound of formula XII is isolated. Hydrolysis of the compound of formula XII with 0.01 to 0.1 molar equivalents of concentrated hydrochloric acid in aqueous methanol at 60° to 70° C. for 30 minutes to two hours gives the corresponding compound of formula XIII in which R 1 , m and Alk are as defined herein. Condensation of the compound of formula XII with a phenyl hydrazine of formula XIV in which R 3 and R 4 are as defined herein according to the conditions of the Fischer indole reaction gives the corresponding indole of formula XV in which R 1 , R 2 , R 3 , R 4 , m, n and Alk are as defined herein. Preferred conditions for this Fischer indole reaction involves: reacting the compound of formula XIII with an equivalent molar amount of the phenyl hydrazine of formula XIV in isobutanol under anhydrous conditions at 100° to 110° C. for 20 to 30 hours; evaporating the latter solution; reacting the residue with aqueous sulfuric acid solution, preferably about ten percent sulfuric acid, at 90° to 110° C. for 10 to 20 minutes; and isolating the indole of formula XV. The indole of formula XV is reacted with about one molar equivalent of osmium tetroxide in a solvent of tetrahydrofuran and pyridine at about -78° C. for about 10 minutes and at about 0° C. for one to three hours to obtain the diol of formula XVI in which R 1 , R 2 , R 3 , R 4 , m, n and Alk are as defined herein. Oxidation of the compound of formula XVI in which R 1 , R 3 , R 4 , m, n and Alk are as defined herein and R 2 is hydrogen with about one molar equivalent of sodium metaperiodate in a solution of aqueous acetone at 50° to 70° C. for 10 to 50 seconds, followed by the addition of a catalytic amount of phosphoric acid, and heating the resulting solution at 50° to 70° C. for 20 to 40 minutes gives the corresponding compound of formula XVII in which R 1 , R 3 , R 4 , m, n and Alk are as defined herein. Reduction of the latter compound with about one molar equivalent of sodium borohydride in ethanol at 20° to 30° C. for 10 to 25 hours gives the corresponding compound of formula II in which R 1 , R 3 , R 4 , m and n are as defined herein and R 2 is hydrogen. Similarily, oxidation of the compound of formula XVI in which R 1 , R 3 , R 4 , m, n and Alk are as defined herein and R 2 is lower alkyl with sodium metaperiodate followed by reduction of the aldehyde, so formed, with sodium borohydride gives the corresponding compound of formula II in which R 1 , R 3 , R 4 , m and n are as defined herein and R 2 is lower alkyl. The above described series of reactions, as illustrated in reaction scheme 3, is especially useful for preparing the compounds of formula II in which R 1 , R 2 , R 3 and R 4 are as defined herein, and m and n are 2. A preferred method of preparing the compounds of formula II in which R 1 , R 2 , R 3 , R 4 and m are as defined herein and n is 1 is illustrated in reaction scheme 4. ##STR7## As illustrated in reaction scheme 4, an ester of formula XVIII in which Alk is lower alkyl is condensed with one to three molar equivalents of a lactone of formula XIX in which m is as defined herein in the presence of two to five molar equivalents of potassium carbonate in acetone to give the corresponding compound of formula XX in which Alk and m are as defined herein. Hydrolysis of the compound of formula XX, preferably with a solution of 10 to 30% sulfuric acid at 80° to 100° C. for 18 to 30 hours, gives the corresponding compound of formula XXI in which R 1 is hydrogen and m is as defined herein. If desired, the latter compound of formula XXI is alkylated with a lower alkyl bromide, chloride or iodide, in the same manner as described above for the alkylation of the compound of formula XI with 3-bromo-1-propene or 4-bromo-1-butene, to give the corresponding compound of formula XXI in which R 1 is lower alkyl and m is as defined herein. The compound of formula XXI in which R 1 and m are as defined herein is condensed with a phenyl hydrazine of formula XIV in which R 3 and R 4 are as defined herein according to the conditions of the Fischer indole reaction, in the same manner as described above, to give the corresponding compound of formula II in which R 1 , R 2 , R 3 , R 4 and m are as defined herein and n is 1. The following examples illustrate further this invention. EXAMPLE 1 γ-[(Dimethylamino)methyl]-1-methyl-1,2,3,4-tetrahydrocarbazole-1-propanol (I: R 1 , R 5 and R 6 =Me, R 2 , R 3 and R 4 =H, and m and n=2) A 50% sodium hydride dispersion in oil (3.71 g, 0.077 mole) was washed with petroleum ether to remove the oil and the hydride was covered with tetrahydrofuran (50 ml) which has been freshly distilled over lithium aluminum hydride. To the stirred suspension was added dropwise, via a septum, ethyl acetoacetate (V: R 1 =Me and Alk=Et; 9.8 ml, 0.077 mole). To this solution was added rapidly 3-(2-bromoethyl)-indole (IV: R 2 , R 3 and R 4 =H and n=2; 15.7 g, 0.070 mole). The resulting mixture was refluxed for 20 hr. After cooling, the reaction mixture was poured into water and the product was extracted with diethyl ether. The extract was washed with water and dried over magnesium sulphate. Evaporation of solvent afforded an oil (15.2 g) which was chromatographed through a column of silica gel (840 g) using 10% acetone in benzene to give 2-acetyl-4-(1H-indol-3-yl)-butanoic acid, ethyl ester (VI: R 1 =Me, R 2 , R 3 and R 4 =H, n=2 and Alk=Et) as an oil: nmr(CDCl 3 )β 1.25 (t, 3H), 2.15 (s, 3H), 2.25 (m, 2H), 2.75 (m, 2H), 3.45 (t, 1H), 4.13 (q, 2H), 7.2 (m, 5H) and 7.95 (s, 1H), and Anal. Calcd for C 16 H 19 NO 3 :C, 70.30% H, 7.01% N, 5.12% and Found: C, 70.00% H, 7.07% N, 4.87%. To a mixture of barium hydroxide octahydrate (3.18 g) in water (48 ml) was added a solution of the latter keto ester (2.32 g, 0.085 moles) in ethanol (12 ml). This mixture was refluxed and stirred for 18 hr. After cooling, the solution was acidified with 6N hydrochloric acid (effervescence) and the product was extracted with methylene chloride. The organic layer was washed with water and dried over magnesium sulphate. Evaporation of solvent afforded an oil (1.66 g) which crystallized on standing. This was chromatographed through a silica gel column (48 g) using 10% acetone in benzene to give 1.22 g of a residue which was crystallized from dichloromethane-hexane to give 3-(4-oxopentyl)-indole: mp 89°-90° C.; nmr(CDCl 3 )β2.05 (s, 3H), 2.4 (m, 6H), 7.1 (m, 4H) and 7.85 (broad, 1H); and Anal. Calcd for C 13 H 15 NO: C, 77.58% H, 7.51% N, 6.96% and Found: C, 77.83% H, 7.47% N, 6.67%. To diisopropylamine (1.68 ml, 0.012 moles) in anhydrous tetrahydrofuran (12 ml, freshly distilled over lithium aluminum hydride) at 4° C. was added dropwise through a septum, a 2.3 M solution of butyllithium in hexane (5.2 ml, 0.012 moles) maintaining the temperature at 4° C. This was stirred at this temperature for 15 min then cooled to -78° C. To this solution was added dropwise a solution of γ-butyrolactone (VIII: m=2; 0.93 ml, 0.012 moles) in dry tetrahydrofuran (12 ml). This was stirred at -78° C. for 20 min and then a solution of 3-(4-oxopentyl)-indole (1.2 g, 0.012 moles) in a mixture of dry tetrahydrofuran (3 ml) and hexamethylphosphoric triamide (2.5 ml) was added. The temperature was raised to -40° C. and maintained at this temperature for 45 min. The cooling bath was removed and water (30 ml) was added to the solution. The reaction mixture was poured into water and the product was extracted with diethyl ether. The extract was washed with water and dried over magnesium sulphate. Evaporation of solvent afforded an oil (1.72 g) which was chromatographed through a silica gel column (40 g) using 35% acetone in benzene to afford an oil (1.44 g) of the diastereoisomeric mixture of dihydro-3-[2-hydroxy-5-(1H-indol-3-yl)-2-pentyl]-2(3H)-furanone: ir(CHCl) 3 ) 3470 and 1750 cm -1 ; and nmr(CDCl 3 ) β 1.17 and 1.25 (singlets, 3H), 2.5-3.0 (m, 3H), 3.9-4.4 (m, 2H), 6.9 (s, 1H), 7.0-7.6 (m, 4H) and 7.92 (broad, 1H). A diastereoisomeric mixture of the latter hydroxy lactone (410 mg, 0.0014 mole) in boron trifluoride etherate (20 ml) was refluxed for 1 hr. After cooling, the reaction mixture was poured into water and the product was extracted with methylene chloride. The organic layer was washed with water and dried over magnesium sulphate. Evaporation of solvent afforded an oil which was chromatographed through a silica gel column (10 g) using 10% acetone in benzene to yield an oil (20.3 mg) of diastereoisomeric mixture of dihydro-3-(1,2,3,4-tetrahydro-1-methylcarbazole)-2(3H)-furanone: nmr(CDCl 3 ) β 1.35 and 1.75 (singlets, 3H), 2.6-3.1 (m, 3H), 3.9-4.5 (m, 2H), 6.9-7.5 (m, 4H) and 9.95 (broad, 1H); and Anal. Calcd for C 17 H 19 NO 2 : C, 75.81% H, 7.11% N, 5.20% and Found: C, 75.72% H, 7.31% N, 4.94%. The isomeric mixture of the latter furanone (6.50 g, 0.024 mole) was dissolved in 250 ml of a solution of 45% dimethylamine, the amine of formula HNR 5 R 6 in which R 5 and R 6 each is methyl, in methanol. The solution was refluxed for 6 days. Evaporation of the solvent afforded an oil (7.40 g) consisting of a mixture of two isomeric amides which was chromatographed through a silica gel column (400 g). Elution with 35% acetone in benzene afforded a residue (3.42 g) which was crystallized from benzene-hexane to give isomer A of 1,2,3,4-tetrahydro-α-(2-hydroxyethyl)-N,N,1-trimethylcarbazole-1-acetamide: mp 168°-169° C.; nmr(CDCl 3 )β 1.3 (s, 3H), 3.1 (s, 3H), 3.25 (s, 3H), 7.15 (m, 4H) and 10.7 (s, 1H); and Anal. Calcd for C 19 H 26 N 2 O 2 : C, 72.57% H, 8.34% N, 8.91% and Found: C, 72.69% H, 8.35% N, 8.65%. Elution of the latter column with 75% acetone in benzene gave a residue (2.4 g) which was crystallized from dichloromethanehexane to obtain isomer B of 1,2,3,4-tetrahydro-α-(2-hydroxyethyl)-N,N,1-trimethylcarbazole-1-acetamide; mp 145°-146° C.; and nmr(CDCl 3 )β1.45 (s, 3H), 2.5 (s, 3H), 2.75 (s, 3H), 7.2 (m, 4H) and 8.05 (s, 1H). A solution of isomer A of the latter acetamide (2.91 g, 0.0092 moles) in dry tetrahydrofuran (30 ml) was added dropwise to a stirred suspension of lithium aluminum hydride (0.873 g, 0.023 moles) in dry tetrahydrofuran (30 ml) cooled to 0° C. The mixture was stirred at reflux for one hour. After cooling in ice-water bath, a water-tetrahydrofuran (1:1) mixture was added dropwise to destroy the excess hydride. The inorganic salts were filtered off, and the filtrate was concentrated and dissolved in chloroform. The chloroform layer was washed twice with water, dried over magnesium sulfate and concentrated to yield a residue (2.49 g) which was crystallized out of chloroform and hexane to give 1.75 g of isomer-A of the title compound: mp 249°-251° C.; nmr(CDCl 3 )β1.2 (s, 3H), 1.93 (s, 6H), 3.2 (m, 2H), 5.8 (broad, 1H), 7.0 (m, 4H) and 10.6 (s, 1H); and Anal. Calcd for C 19 H 28 N 2 O: C, 75.95% H, 9.39% N, 9.33% and Found: C, 75.91% H, 9.39% N, 9.19%. Similarily, by replacing isomer-A with isomer-B of the above acetamide, isomer-B of the title compound is obtained: mp 214°-215° C. (crystallized from dichloromethane-diethyl ether-hexane); nmr(CDCl 3 )β 1.33 (s, 3H), 2.3 (s, 6H), 3.5 (m, 2H), 7.2 (m, 4H) and 8.5 (s, 1H); and Anal. Calcd for C 19 H 28 N 2 O: C, 75.95% H, 9.39% N, 9.33% and Found: C, 75.80% H, 9.56% N, 9.46%. By following the procedure of this example and using the appropriate compounds of formulae IV, V and VIII and amine of formula HNR 5 R 6 , other compounds of formula I are obtained. For example, by using 3-(2-bromoethyl)-4-chloroindole, ethyl acetoacetate γ-butyrolactone and dimethylamine, 5-chloro-γ-[(dimethyl-amino)methyl]-1-methyl-1,2,3,4-tetrahydrocarbazole-1-propanol is obtained. Similarly, by replacing ethyl acetoacetate with an equivalent amount of 3-oxopropanoic acid, ethyl ester or 3-oxopentanoic acid, ethyl ester, the following compounds of formula I are obtained, respectively: γ-[(dimethylamino)-methyl]-1,2,3,4-tetrahydrocarbazole-1-propanol and γ-[(dimethylamino)methyl]-1-ethyl-1,2,3,4-tetrahydrocarbazole-1-propanol. EXAMPLE 2 Alternative Preparation of Dihydro-3-(1,2,3,4-tetrahydro-1-methylcarbazole-2(3H)-furanone (II: R 1 =Me, R 2 , R 3 and R 4 =H, and m and n=2) A solution consisting of 1-methyl-2-oxocyclohexane-1-acetic acid methyl ester (18.4 g, 0.1 mole), trimethylorthoformate (13.1 ml, 0.12 mole) and 15 drops of concentrated sulfuric acid, in anhydrous methanol, was refluxed for 4 hours. After cooling, enough 50% sodium hydroxide was added dropwise to dissipate the dark red color to a light yellow-orange solution. This solution was evaporated and the residue was partitioned between diethyl ether and 5% aqueous sodium bicarbonate. The ethereal layer was washed with brine and dried over magnesium sulfate. Evaporation of the solvent, gave an oil (19.6 g) which was distilled under reduced pressure through a short vigreux column to yield 15.32 g of 2-methoxy-1-methyl-2-cyclohexane-1-acetic acid, methyl ester: ir(film) 1730 and 1650 cm -1 ; and nmr(CDCl 3 ) β 1.2 (s, 3H), 1.3-2.2 (m, 6H), 2.45 (s, 2H), 3.45 (s, 3H), 3.65 (s, 3H) and 4.55 (t, 1H). A solution of diisopropylamine (0.7 ml, 0.005 moles) in anhydrous tetrahydrofuran (10 ml) was cooled to about 4° C. and stirred under nitrogen. A 1.82 M solution of butyllithium in hexane (2.75 ml, 0.005 moles) was added slowly (through a septum) at such rate to maintain the temperature at about 4° C. Stirring was continued for 15 minutes at about 4° C. then the solution was cooled to -78° C. To this was added (through a septum) 2-methoxy-1-methyl-2-cyclohexene-1-acetic acid, methyl ester (1.0 g, 0.005 moles) and stirring was continued for 1 hour at -78° C. A mixture of allylbromide (0.52 ml, 0.0055 moles) and hexamethylphosphoric triamide (0.3 ml) was then added to the solution and stirring was continued at -78° C. for 15 minutes. The solution was warmed to -50° C. and stirring was continued for 0.5 hour at this temperature. Then the solution was slowly allowed to reach room temperature and stirring was continued overnight. Hydrochloric acid 2N (20 ml) was added to the stirred solution which was then poured onto ice water. The product was extracted with diethyl ether, the organic solution was washed with a saturated sodium bicarbonate solution, and dried over magnesium sulfate. Evaporation of the solvent gave 1.19 g of an oil which was chromatographed through a silica gel column (50 g) using 1% acetone in benzene to give an oil (0.50 g) of 2-methoxy-1-methyl-α-(2-propenyl)-2-cyclohexene-1-acetic acid, methyl ester: ir(film) 3050, 1725, 1650 and 1630 cm -1 ; and nmr(CDCl 3 ) δ 1.2 (s, 3H), 1.4-2.4 (m, 9H), 3.4 (s, 3H), 3.55 (s, 3H), 4.55 (t, 1H), 4.95 (m, 2H), and 5.4-5.7 (m, 1H). To the latter enol ether (4.7 g, 0.020 moles) in methanol (90 ml), was added water (13 ml) and concentrated hydrochloric acid (13 drops). This solution was stirred and refluxed for one hour. After cooling the methanol was evaporated to give an oil which was partitioned between diethyl ether and water. The ethereal phase was washed with saturated sodium bicarbonate solution and water, and dried over magnesium sulfate. Evaporation of the solvent gave a crude product (4.12 g) of 1-methyl-α-(2-propenyl)-2-oxocyclohexane-1-acetic acid, methyl ester; ir(film) 1730, 1710 and 1630 cm -1 ; and nmr(CDCl 3 ) δ 1.10 and 1.15 (singlets, 3H), 2.85-3.1 (m, 1H), 3.57 and 3.65 (singlets, 3H), 4.95 (m, 2H) and 5.4-6.0 (m, 1H). A mixture of the latter keto ester (36.0 g, 0.161 mole) and phenylhydrazine (16 ml, 0.161 mole) in isobutanol (600 ml) was refluxed under anhydrous conditions for 24 hours. After cooling, the solvent was evaporated to give an oil to which was added a 10% aqueous sulfuric acid solution (600 ml). The resulting mixture was refluxed for 15 minutes with a vigorous mechanical stirring. The cooled mixture was saturated with sodium chloride and the product was extracted with a diethyl ether:dichloromethane (3:1) mixture. The organic layer was washed with a saturated sodium bicarbonate solution and brine, and dried over magnesium sulfate. Evaporation of the solvent gave an orange oil (39.2 g) which was chromatographed through a silica gel column (1.2 kg), using a benzene:petroleum ether (3:1) mixture, to give an oil (5.81 g). This oil was crystallized from petroleum ether to give 1,2,3,4-tetrahydro-α-(2-propenyl)-1-methylcarbazole-1-acetic acid, methyl ester; mp 115°-116° C.; nmr(CDCl 3 )δ 1.35 (s, 3H), 1.6-2.2 (m, 6H), 2.4-2.9 (m, 3H), 3.80 (s, 3H), 4.95 (m, 2H), 5.4-5.9 (m, 1H), 6.95-7.5 (m, 4H) and 9.6 (broad, 1H); and Anal. Calcd for C 19 H 23 NO 2 : C, 76.74% H, 7.79%, N, 4.76% and Found: C, 76.49% H, 7.86% N, 4.65%. Osmium tetroxide (7.50 g, 0.029 mole) in dry tetrahydrofuran (30 ml) was added to a stirred solution at -78° C. of the latter olefinic ester (7.98 g, 0.027 mole) in dry pyridine (30 ml) and dry tetrahydrofuran (75 ml). Stirring was continued at -78° C. for 10 minutes and at 0° C. for 1.5 hours. The reaction mixture was then stirred with a solution of sodium bisulfite (15.0 g) in water (150 ml) and pyridine (150 ml) for 30 minutes at room temperature. The mixture was poured into water (2000 ml) and the product was extracted with ethyl acetate. The organic phase was washed with 2 N hydrochloric acid, saturated sodium bicarbonate solution and water, and dried over magnesium sulfate. Evaporation of the solvent gave an oil (8.86 g) which was chromatographed through a silica gel column (250 g) using 35% acetone in benzene, to give 1,2,3,4-tetrahydro-α-(2,3-dihydroxypropyl)- 1-methylcarbazole-1-acetic acid, methyl ester (6.98 g): ir(CHCl 3 ) 3560, 3380 and 1712 cm -1 ; and nmr(CDCl 3 ) δ 1.35 (s, 3H), 3.82 (s, 3H), 7.25 (m, 4H) and 9.55 (broad, 1H). A stirred solution of the latter diol (296 mg, 0.0009 mole) in acetone:water (1:1) (5 ml) was heated to 65° C. Then was added in one portion a solution of sodium metaperiodate (192 mg, 0.0009 mole), in water (1.5 ml). After 30 seconds, 1 drop of phosphoric acid was added and heating at 65° C. was continued for 25 min. After cooling, the solution was poured into water and the product was extracted with diethyl ether. The ethereal solution was washed with water and dried over magnesium sulfate. Evaporation of the solvent gave an oil (252 mg) which was chromatographed through a silica gel column (30 g) using 10% acetone in benzene to give 1,2,3,3a,4,5,6-heptahydro-1-hydroxy-3a-methyl-10b-azofluoranthene-3-formic acid, methyl ester (0.155 g): ir(CHCl 3 ) 3550 and 1725 cm -1 ; and nmr(CDCl 3 )δ 1.25 and 1.40 (singlets, 3H), 3.7 (s, 3H), 6.05 (broad, 1H) and 7.0-7.4 (m, 4H). Sodium borohydride (0.876 g, 0.024 mole) was added to a stirred solution of the latter hydroxy ester (6.84 g, 0.023 mole) in ethanol (135 ml). Stirring was continued at room temperature for 17 hours. The solvent was evaporated and the residue was partitioned between diethyl ether and water. The ethereal phase was washed with water and dried over magnesium sulfate. Evaporation of the solvent gave an oil (5.896 g) which was chromatographed through a silica gel column (300 g) using 5% acetone in benzene to give a diastereoisomeric mixture of the title compound (4.097 g), which is identical to that prepared in Example 1. EXAMPLE 3 α-(N,N-Dimethylaminomethyl)-1,2,3,4-tetrahydrocyclopent[b]indole-3-propanol (I: R 1 , R 2 , R 3 and R 4 =H, R 4 and R 5 =Me, m=2 and n=1) α-Bromobutyrolactone (33.0 g, 0.2 mole) was added dropwise to a well stirred suspension of a mixture of ethyl and methyl esters of 2-oxocyclopentanecarboxylate (15.06 g, 0.1 mole) and potassium carbonate (55.2 g, 0.4 mole) in dry acetone (150 ml). The mixture was refluxed for 4.5 hours and became deep purple. The mixture was filtered and the filtrate was evaporated to dryness. The residue was partitioned between water and diethyl ether. The organic phase was washed with brine, dried over magnesium sulfate and concentrated. The residue (28.4 g) was distilled under vacuum to afford a mixture (16.5 g) of the methyl and ethyl esters of 1-(2-oxotetrahydrofuran-3-yl)-2-oxocyclopentanecarboxylic acid: nmr(CDCl 3 )δ1.3 (t, 60% of 3H), 1.6-3.0 (m, 8H), 3.4 (m, 1H), 3.75 (m, 40% of 3H) and 3.9-4.5 (m, 4H). A suspension of the latter mixture (36.1 g, 0.15 mole) in 20% aqueous sulfuric acid (175 ml) was heated with stirring on steam bath overnight. A clear homogeneous solution was obtained. After cooling to room temperature, it was saturated with salt and extracted with ethyl acetate. The oranic extracts were combined and washed with brine, dried over magnesium sulfate, filtered and concentrated in a regular distillation apparatus. The residue was distilled at 125°-7° C. under 0.3 mm Hg using a Vigreux distilling unit to yield 17.1 g of 4,5-dihydro-3-(2-oxocyclopentan-1-yl)-2(3H)-furanone: bp 125°-127° C./0.3 mm Hg; nmr(CDCl 3 )δ1.6-3.3 (m, 10H) and 4.3 (m, 2H); and Anal. Calcd for C 9 H 12 O 3 : C, 64.27% H, 7.19% and Found: C, 63.56% H, 7.22%. A mixture of the latter compound (19.4 g, 0.080 mole) and phenylhydrazine hydrochloride (12.71 g, 0.088 mole) in acetic acid (100 ml) was refluxed for 55 min, cooled and poured slowly over ice-water (500 ml). The cooled solution was basified with sodium carbonate and extracted with chloroform. The organic layer was washed with brine, dried over magnesium sulfate and concentrated to give 25.1 g of brown oil which was chromatographed on silica gel (750 g) with 7.5% acetone-benzene mixture. The initial fractions were collected (4.89 g) and crystallized from benzene-hexane to give dihydro-3-(1,2,3,4-tetrahydrocyclopent[b]indol-3-yl)-2(3H)-furanone: mp 155°-157° C.; nmr(CDCl 3 )δ2.5 (m, 8H), 4.2 (m, 2H), 7.25 (M, 4H) and 9.3 (broad, 1H); and Anal. Calcd for C 15 H 15 NO 2 : C, 74.66% H, 6.27% N, 5.81% and Found: C, 74.77% H, 6.36% N, 6.07%. A suspension of the latter compound (3.2 g, 0.013 mole) in methanol (200 ml) was treated with dimethylamine gas (25 ml) and refluxed with stirring for 72 hr. Methanol was distilled off and the residue was chromatographed on silica gel (140 g) with 10% acetone-benzene. The initial less polar fractions were collected and crystallized from benzene-hexane to give 1.74 g of isomer A of α-(2-hydroxyethyl)-N,N-dimethyl-1,2,3,4-tetrahydrocyclopent[b]indole-3-acetamide; mp 118°-120° C.; nmr(CDCl 3 )δ1.7 (m, 2H), 2.2 (m, 1H), 2.8 (m, 4H), 2.95 (s, 3H), 3.06 (s, 3H), 3.5 (m, 4H), 7.15 (m, 4H) and 9.0 (s, 1H); and Anal. Calcd for C 17 H 22 N 2 O 2 : C, 71.30% H, 7.74% N, 9.78% and Found: C, 71.12% H, 7.74% N, 9.64%. The latter more polar fractions were collected and crystallized from benzene-hexane to give 10.6 g of isomer B of α-(2-hydroxyethyl)-N,N-dimethyl-1,2,3,4-tetrahydrocyclopent[b]indole-acetamide; mp 135°-137° C.; nmr(CDCl 3 )δ2.72 (s, 3H), 2.92 (s, 3H), 7.15 (m, 4H), and 8.3 (s, 1H); and Anal. Found: C, 71.49% H, 7.81% N, 9.69%. A solution of isomer A of α-(2-hydroxyethyl)-N,N-dimethyl-1,2,3,4-tetrahydrocyclopent[b]indole-3-acetamide (1.72 g, 0.0060 mole) in dry tetrahydrofuran (50 ml) was added dropwise to a stirred suspension of lithium aluminium hydride (0.68 g, 0.018 mole) in dry tetrahydrofuran (50 ml) at 0° C. under nitrogen. The suspension was stirred and refluxed for three hrs. It was cooled in an icebath and a mixture of water-tetrahydrofuran (1:4) was added carefully to destroy excess lithium aluminum hydride. The inorganic salts were filtered through a celite pad and the filtrate was diluted with diethyl ether, washed with brine, dried over magnesium sulfate and concentrated to afford an off-white solid (1.53 g). It was recrystallized from dichloromethane-benzene-hexane to give 0.90 g of isomer A of the title compound: mp 152°-153° C.; nmr(CDCl 3 )δ2.2 (s, 6H), 3.7 (m 2H), 7.15 (m, 4H) and 8.4 (s, 1H) and Anal. Calcd for C 17 H 24 N 2 O: C, 74.96% H, 8.83% N, 10.29 % and Found: C, 75.09% H, 9.09% N, 10.39%. The latter reduction was repeated using isomer B of α-(2-hydroxyethyl)-N,N-dimethyl-1,2,3,4-tetrahydrocyclopent[b]indole-3-acetamide to give isomer B of the title compound: mp 168°-169° C.; nmr(CDCl 3 )δ2.22 (s, 6H), 7.2 (m, 4H), 7.25 (s, 1H) and 8.8 (s, 1H); and Anal. Calcd for C 17 H 24 N 2 O: C, 74.96% H, 8.88% N, 10.29% and Found: C, 74.96% H, 9.18% N, 10.01%.

Indole derivatives characterized by having a 1,2,3,4-tetrahydrocarbazole or 1,2,3,4-tetrahydrocyclopent[b]indole nucleus with a hydroxyalkanamine substituent are disclosed. The nucleus is optionally further substituted at various positions. The derivatives are useful diuretic agents, and methods for their preparation and use are also disclosed.

RELATED APPLICATION This application is a continuation of U.S. application Ser. No. 11/158,922, filed Jun. 22, 2005, now abandoned, which is a continuation of and claims priority to International Application No. PCT/US2003/040865, which designated the United States and was filed on Dec. 22, 2003, published in English, which claims the benefit of U.S. Provisional Application No. 60/436,517, filed Dec. 23, 2002. The entire teachings of the above applications are incorporated herein by reference. BACKGROUND OF THE INVENTION Photoacid generation has become valuable in the fields of photoresists and cationic polymerization. Cationic photopolymerization has developed into an excellent alternative to free-radical photopolymerization for applications that can take advantage of the high speed, low temperature, and environmental friendliness of radiation curing technology. In contrast with radiation curing processes initiated by free radicals, cationic photopolymerization processes are not inhibited by oxygen, and by employing monomers and oligomers such as epoxides and oxetanes that undergo rapid cationic ring opening polymerization (CROP), shrinkage resulting from polymerization can be dramatically reduced. Since the onium salt photoacid generators (PAGs) that are commonly used to initiate cationic photopolymerization are typically sensitive only to ultraviolet light when irradiated directly, photosensitizer dyes are used in conjunction with the PAGs to enable photoinitiated acid generation and cationic photopolymerization at longer wavelengths in the near ultraviolet and visible spectral regions. The ability to employ cationic photopolymerization with visible light combined with the attributes of high photosensitivity and low shrinkage in solventless media at ambient temperatures make this technique attractive for applications such as holographic recording. Since this method of recording uses the entire thickness of the medium to store information, the areal data density increases as the medium thickness increases. Increasing the thickness of the media, however, results in an increase in the absorption of the medium, thereby increasing the optical path length of the medium. In the context of a polymerizable medium, lowering the exposure fluence required to initiate sufficient polymerization to reach the entanglement molecular weight and increasing the polymerization kinetics of the medium often requires increasing the concentration of both the photoacid generator and the photosensitizer dye. Increasing the concentration of the photosensitizer dye, however, results in an increase in the absorption of the medium, thereby increasing the optical path length of the medium. The absorbance of the medium can cause undesirable tradeoffs such as non-uniform polymerization throughout the volume of a polymerizable medium, impaired fidelity of holograms recorded in such media and a diminished increase in the dynamic range of a holographic recording medium as a function of increasing the medium's thickness. The transmittance of the light incident upon the medium, T, decreases with increased absorbance of the medium in accordance with the well known Beer-Lambert law expressed as A = log 10 ⁢ ( I o I ) = ɛ ⁢ ⁢ cl ( 1 ) where A is absorbance of the sample medium, and is also referred to as the optical density of the medium, I 0 is the intensity of the incident light in units of quanta per second, I is the intensity of the light transmitted through the sample medium in units of quanta per second, c is the concentration of the absorbing species in units of mol liter −1 , ε is the molar absorptivitiy in units of liters mol −1 cm −1 and is also referred to as the molecular extinction coefficient, and l is the thickness of the medium in units of cm. Consequently, the amount of light incident upon the sample medium that transmits through the medium, known as the transmittance of the medium, is expressed as T = I I o ⁢ ⁢ and ⁢ ⁢ where ⁢ ⁢ A = log 10 ⁢ T . ( 2 ) The decrease in light intensity with depth into the medium from the front surface of the medium leads to non-uniformity of the extent of polymerization that occurs within the medium, so that less polymerization occurs depthwise in the interior of a medium as compared to at or near the front surface that is exposed to the incident light. Under ideal circumstances, the amount of light penetrating into a medium would be capable of initiating an identical number of polymerization events at all depths and thus the extent of polymerization would be uniform throughout the depth of the medium. In reality this cannot occur in a medium that exhibits reasonable sensitized polymerization kinetics and thus the degree of chemical segregation, concomitant with the extent of polymerization, is nonuniform through the depth of the recording medium. The degree of this nonuniformity can be significant if high absorbance is needed to achieve good recording sensitivity or if increases in media thickness are required to establish a roadmap for increased capacity of information stored in a set form factor such as a disk or card. The characteristic level of absorbance of a sensitized medium is crucial in applications such as holographic recording media, where uniformity of the refractive index modulation of each hologram, which develops from chemical segregation that is induced by polymerization reactions, is critical. In particular, angle multiplexing methods of various types are used to record holograms in co-locational or substantially overlapped areas in order to achieve high areal density. Such methods typically result in formation of holograms that exhibit diffraction efficiency less than about 0.05% and which are required to exhibit both good angular selectivity characteristics and good image quality. Typically, a first hologram is recorded and then a second hologram is recorded using a reference beam angle where most desirably the first hologram has a first minimum of intensity (the “null” or minimum of the Bragg selectivity curve). Subsequent holograms recorded in substantially the same storage location are similarly recorded most desirably at the first such minimum of intensity of the hologram that is recorded with the most similar reference beam angle. If the Bragg selectivity curve, however, exhibits increased intensity at the angle of the expected first minimum, and thus a poorly defined first minimum exists which, by way of example, is commonly observed as a shoulder of the main Bragg peak, then the multiplexed holograms must instead be recorded at the second minimum or “null” of the Bragg selectivity curve. The deviation from an ideal sinc 2 Bragg selectivity profile, that in accordance with coupled wave analysis (see Kolgenik, Bell Syst. Tech. J. 48: 2909, (1969)) represents the theoretical dependence of angle versus intensity for the reconstruction of the holograms, is reduced by a factor of four at t the second “null” and thus the overall crosstalk noise is also reduced by factor of four (see Waldman et al., J. Imag. Sci. Tech., Vol 41, No. 5, pp 508-513 (1997)). Multiplexing holograms at angles corresponding to the second such minimum, however, lowers the areal density that can be achieved for a particular thickness of media by a factor of two from what would most desirably be achieved. One solution to this problem of cross talk, and to the broader problem of having non-uniform polymerization throughout the volume of a polymerizable medium, is to reduce the extinction coefficient of a photosensitizer dye. The effects of lowering the extinction coefficient or required concentration of a dye are most apparent when it is desirable to use a thicker polymerizable medium (e.g., to hold more information per unit surface area) or when a hologram must have high fidelity. At concentrations that generate both a useful amount of polymerization and high recording sensitivity, presently available photosensitizer dyes are limited to use in polymerizable media with thicknesses of about 300 micrometers or less. This deficiency necessitates the invention of new sensitizer dyes tailored so as to have lower extinction coefficient at the wavelength of interest, thereby permitting its use in higher concentration while maintaining lower overall absorbance. Sufficient dye is then available such that the maximum state of polymerization is limited only by monomer mobility rather than by the number of dye molecules, and exposure non-uniformity is minimized. Presently available photosensitizer dyes such as rubrene and 5,12-bis(phenylethynyl)naphthacene (BPEN) have extinction coefficients at specific wavelengths of visible light, especially light in the 500-550 nm region (e.g., from commercially-available lasers such as an argon ion laser or frequency-doubled Nd:YAG laser) that result in reduced performance when used in relatively thick holographic recording media having thicknesses greater than about 300 micrometers. It is therefore desirable to develop photosensitizer dyes with reduced extinction coefficients at selected visible wavelengths, especially in the 500-550 nm region, such that the absorbance of a sufficient quantity of sensitizer dye (e.g., to achieve polymerization) will be decreased to permit light penetration into a polymerizable medium and to preserve acceptable uniformity of polymerization within the polymerizable medium. The recording media is made sensitive to actinic radiation of a desired energy level (wavelength) by the incorporation of a sensitizer dye. The normal polymerization procedure is to irradiate the photopolymer with photons which will then begin the polymerization process. The reaction sequence associated with this process is complex. A simplified, but reasonably good model is as follows: the dye is first excited by photons and then the excited dye transfers energy to the initiator to provide an excited initiator or the excited dye reacts with the initiator via a oxidation-reduction process to form an initiative species. In either case the initiative species or excited initiator then combines with a monomer, which begins a chain reaction with additional monomers to result in polymerization. Photosensitizer dyes should also undergo efficient electron transfer reactions and preferably bleach completely at the relevant wavelength when exposed to visible light in the presence of an onium salt (e.g., a wavelength corresponding to a laser). In addition, photosensitizer dyes should have adequate solubility, especially in cationic polymerization media, and should not inhibit cationic processes (e.g., should be sufficiently non-basic). SUMMARY OF THE INVENTION This invention provides a series of novel 5-alkynyl substituted naphthacene dyes. This invention further provides such dyes that are efficient photosensitizers for onium salt photoacid generators (PAGs) when exposed to actinic radiation. Additionally, such dyes further exhibit desirably low extinction coefficients, thus making it possible to employ the dyes of the present invention within thicker layer of recordable media than previously achievable (Example 5). This invention also provides a process for use of these dyes for the uniform polymerization of thick media. Even further, this invention provides a process or method for the utilization of these dyes for the recording of holograms with good recording sensitivity and good image fidelity. Holographic recording media (HRM) comprising inventive dyes of the present invention showed high signal-to-noise ratio for a given number of images (as indicated by high cumulative grating strength) and achieved recording sensitivity better than an HRM of the same thickness comprising a sensitizing dye of prior art (Example 6). The enhanced recording sensitivity exhibited by use of a sensitizer of the present invention is more advantageous as the thickness of the recording media is increased further, as the limitations due to low concentration of the dye become more severe. Furthermore, the photosensitizer dyes of this invention also preferably completely bleach upon exposure to light when used in combination with a photoacid generator. The present invention includes a dye represented by Structural Formula (I): In Structural Formula (I), R 1 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group or —Si(R 5 ) 3 . R 2 , R 3 , and R 4 are each independently —H, a halogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkylethynyl group, a substituted or unsubstituted alkenylethynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or the group —C≡C—Si(R 5 ) 3 . Each R 5 is independently a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group. Rings A and B are independently substituted or unsubstituted, but are preferably unsubstituted. In another embodiment, the present invention is a polymerizable medium, comprising: a) a dye disclosed herein; b) a compound, referred to as a “PAG,” which in combination with said dye produces acid when exposed to actinic radiation; and c) at least one monomer or oligomer which is capable of undergoing cationic polymerization initiated by said acid. One type of polymerizable medium is a holographic recording medium, where the medium comprises: a) a dye (e.g., dyes which can sensitize photoacid generating compounds); b) a compound, referred to as a “PAG,” which in combination with said dye produces acid when exposed to actinic radiation; c) a monomer or oligomer which is capable of undergoing cationic polymerization initiated by said acid; and d) a binder that is capable of supporting cationic polymerization of the monomer or oligomer, where said dye exhibits substantially complete photobleaching. The medium is advantageously greater than 300 μm thick. Another type of polymerizable medium is a holographic recording medium, where the medium comprises: a) a dye disclosed herein; b) a compound, referred to as a “PAG,” which in combination with said dye produces acid when exposed to actinic radiation; c) a monomer or oligomer which is capable of undergoing cationic polymerization initiated by said acid; and d) a binder that is capable of supporting cationic polymerization of the monomer or oligomer. In one aspect, the medium is greater than 300 μm thick. The present invention also includes a method of generating acid, comprising the step of exposing to visible light a composition comprising: a) a dye disclosed herein; and b) a compound, referred to as a photoacid generator (PAG), which in combindation with said dye produces acid when exposed to actinic radiation. In another aspect, the present invention is a method of recording holograms within a holographic recording medium disclosed herein. The method generally comprises the step of passing into the medium a reference beam of coherent actinic radiation and at substantially the same location in the medium simultaneously passing into the medium an object beam of the same coherent actinic radiation, such that the dye disclosed herein in combination with the PAG is capable of producing acid upon exposure to the actinic radiation, thereby forming within the medium an interference pattern and thereby recording a hologram within the medium. Advantages of the present invention include photosensitizer dyes with low extinction coefficients when exposed to visible light. As a consequence, holographic recording media having a thickness greater than about 300 micrometers, and which exhibit good recording sensitivity and good image fidelity, can be prepared with these dyes. These photosensitizer dyes also bleach upon exposure to visible light when in the presence of a photoacid generator. BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a plot of recording sensitivity as a function of cumulative fluence. The result, described in Example 6, compares a holographic recording media (HRM) employing MeOPEN dye of the present invention to an HRM employing a commercially available dye BPEN. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new class of 5-alkynyl substituted naphthacene photosensitizing dyes, which can sensitize onium salt photoacid generators (“PAGs”) when exposed to visible light. Dyes represented by Structural Formula (I) can be substituted with one or more halogen atoms on Rings A and B. Other suitable substituents for Rings A and B include substituted and unsubstituted alkyl groups, alkoxy, trialkylammonium, and diarylamino groups. One preferred dye is represented by Structural Formula (II): R 2 , R 3 and R 5 in Structural Formula (II) are as described above for Structural Formula (I) and R 4 is —H, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. Preferably, the compound represented by Structural Formula (II) is characterized by one or more of the following features: (1) R 4 is a substituted or unsubstituted phenyl group, preferably unsubsituted phenyl, (2) R 2 is —H, (3) R 3 is —H, and (4) each R 5 is an alkyl group, preferably methyl. More preferably, the compound represented by Structural Formula (II) is characterized by Feature (1); Features (1) and (2); Features (1), (2) and (3); or Features (1), (2), (3) and (4). In another preferred embodiment, the photosensitizing dye is represented by Structural Formula (I), where the compound has one or more of the following features: (1) R 1 and R 4 are each a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group, preferably a substituted or unsubstituted aryl group, even more preferably phenyl, (2) R 2 is —H, and (3) R 3 is —H. More preferably, the compound represented by Structural Formula (I) is characterized by Feature (1); Features (1) and (2); or Features (1), (2) and (3). Another preferred dye is represented by Structural Formula (III): R 2 and R 3 in Structural Formula (III) are as described above for Structural Formula (I) and R 1 is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl group. More preferably, the dye represented by Structural Formula (III) is represented by Structural Formula (IV): R 2 and R 3 in Structural Formula (IV) are as described above for Structural (III) and R 10 is —H, a halogen, or an alkyl, alkoxy, trialkylammonium, or a diarylamino group; and y is an integer from 1 to 5. Even more preferably, the dye represented by Structural Formula (IV) is represented by Structural Formula (V): R 2 , R 3 and R 10 in Structural Formula (V) are the same as described above in Structural Formula (IV). The dye represented by Structural Formula (IV) or (V) is preferably characterized by one or more of the following features: (1) R 2 is —H, (2) R 3 is —H, and (3) R 10 is —H, —CH 3 or —OCH 3 . More preferably, the compound represented by Structural Formula (IV) or (V) is characterized by Feature (1); Features (1) and (2); or Features (1), (2) and (3). Photosensitizing dyes of the present invention can be used to sensitize “PAGs” such as iodonium, sulfonium, diazonium or phosphonium salts to produce acid when exposed to actinic radiation. Most commonly, iodonium or sulfonium salts are used. Suitable iodonium salts include (4-octyloxyphenyl)phenyliodonium hexafluoroantimonate, ditolyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium tetrakis(pentafluorophenyl)borate, tolylphenyliodonium tetrakis(pentafluorophenyl)borate, cumyltolyliodonium tetrakis(pentafluorophenyl)borate, di(4-t-butylphenyl)iodonium tris(trifluoromethylsulfonyl)methylate, dicumyliodonium tetrakis(3,5-bistrifluoromethylphenyl)borate, di(4-t-butylphenyl)iodonium tetrakis(3,5-bistrifluoromethylphenyl)borate and cumyltolyliodonium tetrakis(3,5-bistrifluoromethylphenyl)borate. Other suitable sulfonium salts include those disclosed in co-pending U.S. Provisional Patent Application entitled FLUOROARYLSULFONIUM PHOTOACID GENERATORS 60/436,521, filed on Dec. 23, 2002, the teachings of which are incorporated herein by reference. Photosensitizer dyes of the present invention advantageously have extinction coefficients in the visible region, for example, at wavelengths of commercially available solid state lasers such as 532 nm, 528 nm, 523 nm, 488 nm and 460 nm, of less than 16,000 L mol −1 cm −1 , preferably less than 10,000 L mol −1 cm −1 , more preferably less than 6,000 L mol −1 cm −1 , and even more preferably less than 2,000 L mol −1 cm −1 . It is advantageous to increase the thickness of a photopolymerizable holographic recording medium, for example, to increase the amount of information contained per unit area. The medium is advantageously greater than 300 μm thick, greater than 500 μm thick, greater than 1,000 μm thick or greater than 2,000 μm thick. For example, a medium can be greater than 300 μm thick and less than 1000 μm thick, greater than 500 μm thick and less than 1000 μm thick, or greater than 300 μm thick and less than 500 μm thick. Polymerizable recording media with a thickness of less than 300 μm can also be prepared, such as between 100 μm and 300 μm. Monomers suitable for use in polymerizable media include, for examples, those containing epoxide, oxetane, cyclic ether, 1-alkenyl ethers including vinyl ether and 1-propenyl ether, unsaturated hydrocarbon, lactone, cyclic ester, lactam, cyclic carbonate, cyclic acetal, aldehyde, cyclic sulfide, cyclosiloxane, cyclotriphosphazene, or polyol functional groups, and combinations thereof. Epoxides, oxetanes and 1-alkenyl ether functional groups are preferred. A polymerizable medium can contain one or more different polymerizable monomers. Monomers suitable for use in holographic recording media typically undergo acid-initiated cationic polymerization (also referred to as “cationic monomers”), such as epoxides. Siloxanes substituted with one or more epoxide moieties are commonly used in holographic recording media. A preferred type of epoxy group is a cycloalkene oxide group, especially a cyclohexene oxide group. Siloxane monomers can be difunctional, such as those in which two or more epoxide groupings (e.g., cyclohexene oxide groupings) are linked to an Si—O—Si grouping. These monomers have the advantage of being compatible with the preferred siloxane binders. Exemplary difunctional epoxide monomers are those of the formula: RSi(R 1 ) 2 OSi(R 2 ) 2 R  (VI), where each group R is, independently, a monovalent epoxy functional group having 2-10 carbon atoms; each group R 1 is a monovalent substituted or unsubstituted C 1-12 alkyl, C 1-12 cycloalkyl, aralkyl or aryl group; and each group R 2 is, independently, R 1 , or a monovalent substituted or unsubstituted C 1-12 alkyl, C 1-12 cycloalkyl, aralkyl or aryl group. One specific monomer of this type found useful in holographic recording media is that in which each group R is a 2-(3,4-epoxycyclohexyl)ethyl grouping; each grouping R 1 is a methyl group, and each group R 2 is a methyl group, and which is available from Rhodia Silicones, Rock Hill, S.C., under the tradename S 200. The preparation of this specific compound is described in, inter alia, U.S. Pat. Nos. 5,387,698 and 5,442,026. Additional siloxane monomers are described in PCT Publication No. WO 02/19040 and U.S. Publication No. 2002/068223, the teachings of which are incorporated herein by reference. Siloxane monomers that are suitable for use in holographic recording media can also be polyfunctional. A “polyfunctional” monomer is a compound having at least three groups of the specified functionality, in the present case at least three epoxy groups. The terms “polyfunctional” and “multifunctional” are used interchangeably herein. Polyfunctional monomers have the advantage of being compatible with the preferred siloxane binders and providing for rapid structural buildup and high crosslink density. Polyfunctional monomers suitable for use in holographic recording media typically have three or four epoxides (preferably cyclohexene oxide) groupings connected by a linker through a Si—O group, i.e., a “siloxane group”, to a central Si atom. Alternatively, the epoxides are connected by a linker to a central polysiloxane ring. Alternatively, polufunctional monomers suitable for use in holography have a plurality of epoxides as pendant groups on a siloxane polymer, copolymer or oligomer. One example of polyfunctional monomers suitable for use in polymerizable media typically has three or four epoxides (preferably cyclohexene oxide) groupings connected by a linker through a Si—O group, i.e., a “siloxane group”, to a central Si atom. Alternatively, the epoxides are connected by a linker to a central polysiloxane ring. Examples of such polyfunctional monomers are found in U.S. Publication No. 2002/0068223 and PCT Publication WO 02/19040, the contents of which are incorporated herein by reference in their entirety. Specific examples of siloxane monomers of this type include the compounds represented by Structural Formulae (VII)-(XI): Further description of suitable siloxane monomers can be found in U.S. Publication No. 2002/0068223 and PCT Publication WO 02/19040, the teachings of which are incorporated by reference. Optionally, the holographic recording medium additionally comprises a second or third monomer that undergoes cationic polymerization or, alternatively, supports cationic polymerization. Optionally, monomers that support cationic polymerization may be essentially inert to cationic polymerization. In one example, the second monomer is a vinyl ether comprising one or more alkenyl ether groupings or a propenyl ether comprising one or more propenyl ether groupings. In another example, the second monomer is a siloxane comprising two or more or three or more cyclohexene oxide groups, as described above. Advantageously, the second monomer is a siloxane having at least two cyclohexene oxide groups and the third monomer is a siloxane having at least two cyclohexene oxide groups. The use of additional monomers is described in U.S. Ser. No. 08/970,066, filed Nov. 13, 1997, the contents of which are incorporated herein by reference. A binder used in the process and preparation of the present medium should be chosen such that it does not inhibit cationic polymerization of the monomers used (e.g., “supports” cationic polymerization), such that it is miscible with the monomers used, and such that its refractive index is significantly different from that of the polymerized monomer or oligomer (e.g., the refractive index of the binder differs from the refractive index of the polymerized monomer by at least 0.04 and preferably at least 0.09). Binders in this embodiment are not required to increase cohesion in said medium, as is generally the case, and are preferably “diffusible”, but can be substantially or wholly non-diffusible. Diffusable binders can, by way of example, segregate from the polymerizing monomer(s) or oligomer(s) during holographic recording via diffusion-type motion of the binder component. Non diffusible binders can be a monomer(s) or oligomer(s) that is pre-polymerized to form a moderate to high molecular weight polymeric or copolymer structure that supports cationic polymerization and is a substantially non diffusible component relative to the time scale of diffusion processes during holographic recording events. In general, binders can be inert to the polymerization processes described herein or optionally can polymerize (by cationic, free radical or other suitable polymerization) during one or more polymerization events. Preferably, a binder is inert to the polymerization processes defined herein and, even more preferably, is diffusible. Preferred binders for use in holographic recording media are polysiloxanes, due in part to availability of a wide variety of polysiloxanes and the well documented properties of these oligomers and polymers. The physical, optical, and chemical properties of the polysiloxane binder can all be adjusted for optimum performance in the recording medium inclusive of, for example, dynamic range, recording sensitivity, image fidelity, level of light scattering, and data lifetime. The efficiency of holograms produced by the present process in the present medium is markedly dependent upon the particular binder employed. Commonly used binders include poly(methyl phenyl siloxanes) and oligomers thereof, 1,3,5-trimethyl-1,1,3,5,5-pentaphenyltrisiloxane and other pentaphenyltrimethyl siloxanes. Examples are sold by Dow Corning Corporation under the tradename Dow Corning 710 and Dow Corning 705 and have been found to give efficient holograms. Examples of a diffusible binder having a polymerizable moiety can be found in U.S. Pat. No. 5,759,721, the contents of which are incorporated herein by reference. This patent discloses a siloxane polymer having a number of pendant epoxide (cyclohexene oxide) groups. Specifically, the binder was a poly(methylhydrosiloxane) which was hydrosilated with a 90:10 w/w mixture of 2-vinylnaphthalene and 2-vinyl(cyclohex-3-ene oxide). Examples of a substantially non-diffusible, inert binder can be found in U.S. Pat. Nos. 6,103,454 and 6,165,648, the contents of which are incorporated by reference. Additional examples of a substantially non-diffusible, inert binder can be found in Dhar, et al., Optics Letters, Vol. 24, No. 7, p 487-489, 1999 and Hale, et al., Polymer Preprints, 2001, 42 (2), 793, the contents of which are incorporated herein by reference. In such examples, the binder is a solid polymer matrix formed in situ from a matrix precursor by a curing step (curing indicating a step of inducing reaction of the precursor to form the polymeric matrix). It is possible for the precursor to be one or more monomers, one or more oligomers, or a mixture of monomer and oligomer. In addition, it is possible for there to be greater than one type of precursor functional group, either on a single precursor molecule or in a group of precursor molecules. In the present invention, examples of precursors that support cationic polymerization are typically polymerizable by free radical or anionic means and include molecules containing styrene, certain substituted styrenes, vinyl naphthalene, certain substituted vinyl naphthalenes and vinyl ethers, which can optionally be mixed with certain co-monomers. The proportions of PAG, photosensitizing dye, monomer(s) or oligomer(s), and binder in holographic recording media of the present invention may vary rather widely, and the optimum proportions for specific components and methods of use can readily be determined empirically by skilled workers. Guidance in selecting suitable proportions is provided in U.S. Pat. No. 5,759,721, the teachings of which are incorporated herein by reference. The solution of monomers with binder can comprise a wide range of compositional ratios, preferably ranging from about 90 parts binder and 10 parts monomer or oligomer (w/w) to about 10 parts binder and 90 parts monomer or oligomer (w/w). It is preferred that the medium comprise from about 0.167 to about 5 parts by weight of the binder per total weight of the monomers. Typically, the medium comprises between about 0.005% and about 0.5% by weight dye, and between about 1.0% and about 10.0% by weight PAG. Acid generated by the method of the present invention can be used in polymerizing one or more polymerizable monomers, as is described above. Such polymerizable monomers can form protective, decorative and insulating coatings (e.g., for metal, rubber, plastic, molded parts or films, paper, wood, glass cloth, concrete, ceramics), potting compounds, printing inks, sealants, adhesives, molding compounds, wire insulation, textile coatings, laminates, impregnated tapes, varnishes, and antiadhesive coatings. Acid generated by this method can also be used to etch a substrate or to catalyze or initiate a chemical reaction in printed circuit boards or other laser direct imagine processes. A particularly advantageous use of this method is to generate acid uniformly throughout the thickness of the medium in the area of the exposure or illuminated area to maintain optimal physical and optical properties. An aliphatic group is a hydrocarbon group which can be saturated or unsaturated; branched, straight chained or cyclic; and substituted or unsubstituted. Aliphatic groups of the present invention typically have 1 to about 12 carbon atoms. An alkyl group is preferably a straight chained or branched saturated aliphatic group with 1 to about 12 carbon atoms, e.g, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl or octyl, or a saturated cycloaliphatic group with 3 to about 12 carbon atoms. An alkenyl group is preferably a straight chained or branched aliphatic group having one or more double bonds with 2 to about 12 carbon atoms, e.g, ethenyl, 1-propenyl, 1-butenyl, 2-butenyl, 2-methyl-1-propenyl, pentenyl, hexenyl, heptenyl or octenyl, or a cycloaliphatic group having one or more double bonds with 3 to about 12 carbon atoms. An alkynyl group is preferably a straight chained or branched aliphatic group having one or more triple bonds with 2 to about 12 carbon atoms, e.g, ethynyl, 1-propynyl, 1-butynyl, 3-methyl-1-butynyl, 3,3-dimethyl-1-butynyl, pentynyl, hexynyl, heptynyl or octynyl, or a cycloaliphatic group having one or more triple bonds with 3 to about 12 carbon atoms. Suitable aryl groups for the present invention are those which 1) do not react directly with light in the absence of PAG to initiate or induce cationic polymerization; and 2) do not interfere with acid initiated cationic polymerization. Examples include, but are not limited to, carbocyclic groups such as phenyl, naphthyl, biphenyl and phenanthryl. Suitable heteroaryl groups for the present invention are those which 1) do not react directly with light in the absence of PAG to initiate or induce cationic polymerization and 2) do not interfere with acid initiated cationic polymerization. Heteroaryl groups include, but are not limited to, furanyl and fused polycyclic aromatic ring systems in which a carbocyclic aromatic ring or heteroaryl ring is fused to one or more other heteroaryl rings (e.g., benzofuranyl). Suitable substituents on alkyl, alkenyl, alkynyl, aryl, heteroaryl and aliphatic groups are those which 1) do not react directly with light in the absence of PAG to initiate or induce cationic polymerization and 2) do not interfere with acid initiated cationic polymerization. Examples of suitable substituents include, but are not limited to, alkyl, aryl, —OH, halogen (—Br, —Cl, —I and —F), —O(R′), —O—CO—(R′), —COOH, N(Ar′) 2 , —COO(R′), and —S(R′). Each R′ is independently a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aryl group, preferably an alkyl group or an aryl group and each Ar group is a substituted or unsubstituted aryl group preferably a phenyl group. Monosubstituted photosensitizing dyes of the present invention can be prepared by halogenating naphthacene with a suitable agent (e.g., CuBr 2 to brominatenaphthacene at the 5 position). Next, the halogenated naphthacene undergoes a Sonogashira coupling reaction with a substituted acetylene in the presence of suitable catalysts to yield the desired dye (Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron Lett., 1975, 4467). Disubstituted photosensitizing dyes of the present invention can be prepared by a synthetic route comprising two additional steps. For example, naphthacene is halogenated with a suitable agent to produce a 5-halonaphthacene as described above. The 5-halonaphthacene then undergoes a Suzuki coupling reaction with phenylboronic acid in the presence of a suitable catalyst (e.g., dichlorobis(triarylphosphine) palladium(II)) and base to produce 5-phenylnaphthacene (Miyaura, N.; Suzuki, A. Chem. Rev., 1995, 95, 2457). The 5-phenylnaphthacene is again halogenated to give a 5-phenyl-12-halonaphthacene. In the final step, the 5-phenyl-12-halonaphthacene undergoes a Sonogashira coupling reaction with a substituted acetylene to produce the product. EXEMPLIFICATION Example 1 Preparation of A Disubstitued Naphthacene Dye Step 1: 5-Bromonaphthacene This intermediate dye was prepared by modifying the method described in J. Org. Chem., 1970, 35 (5), 1315-18. To an oven-dried 200-ml single-neck round-bottomed flask equipped with a magnetic stirrer and purged with nitrogen were added 1.16 g of naphthacene (Aldrich, 2,3-benzanthracene, C 18 H 12 , 5.1 mmol), followed by 100 ml carbon tetrachloride and 1.6 g copper(II) bromide (Aldrich, CuBr 2 , 7.2 mmol) to form a suspension. A reflux condenser was added to the flask and the mixture was refluxed at 85° C. for 24 hours. After the reaction was cooled to room temperature, the solution was filtered and the solids were rinsed with additional CCl 4 . The solution was concentrated by rotary evaporation to about 50 ml, and passed through a column of neutral alumina (2×12 cm). The solvent was completely evaporated off and the product was dried under vacuum to yield 1.60 g (61%). UV-Vis analysis of the product in THF showed a λ max at 488 nm. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 427 nm, 453 nm and 484 nm. Step 2: 5-Phenylnaphthacene In a 100-ml round-bottomed flask equipped with a magnetic stirrer, were added 1.0 g (3.26 mmol) of 5-bromonaphthacene, 23 mg (0.0326 mmol) of dichlorobis(triphenylphosphine)palladium(II) catalyst and 12 ml of toluene. A solution containing 0.69 g (6.51 mmol) of sodium bicarbonate in 4 ml of water was added to the flask. The mixture was degassed via nitrogen purge for 10 minutes. A solution of 0.417 g (3.42 mmol) of phenylboronic acid in 12 ml of ethanol was then added to the flask, and the reaction mixture was heated to 75° C. and stirred overnight for 15 hours. The resulting reaction mixture contained yellow and white solids that were dissolved by the addition of toluene and water. The mixture was transferred to a 100-ml separatory funnel and the aqueous layer was extracted three times with 15 ml of toluene. After the toluene layer was back-extracted once with distilled water, it was stirred over sodium sulfate for one hour and filtered. Charcoal (2 g) was added to the toluene layer and stirred for a minimum of 2 hours. The charcoal was filtered off and the solvent was removed by rotary evaporation. The product was dried at room temperature under vacuum (product sublimed at higher temperatures). 5-Phenylnaphthacene was obtained in 93% yield (0.92 g) and used without further purification. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 423 nm, 449 nm and 479 nm. Step 3: 5-Bromo-12-phenylnapthacene In a nitrogen flushed 100-ml round-bottomed flask equipped with a magnetic stirrer were added 1 g (3.29 mmol) of 5-phenylnaphthacene and 40 ml of carbon tetrachloride. Copper(II) bromide (2.2 g, 9.86 mmol) was added and the reaction was heated to 75° C. The temperature was maintained at 75° C. for 3-4 hours. Thin layer chromatography (TLC) with hexanes gave two spots with the product having the lower R f . The reaction mixture was filtered and the solvent was removed by rotary evaporation. The crude product was purified by silica gel chromatography with hexanes as the eluent. Pure fractions were combined and the solvent was removed by rotary evaporation. After drying under vacuum, the yield of product was 0.76 grams (60%). The product was used without further purification for the final step. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 435 nm, 462 nm and 493 nm. Step 4: 5-Phenyl-12-(phenylethynyl)naphthacene 5-Bromo-12-phenylnaphthacene (0.600 g, 1.565 mmol), 15 mg of copper(I) iodide (0.0783 mmol), 41 mg of triphenylphosphine (0.157 mmol) and 55 mg of dichlorobis(triphenylphosphine)palladium(II) catalyst (0.0783 mmol) were added to an oven-dried glass pressure tube equipped with a magnetic stirrer. Dry triethylamine (20 ml) was added and the mixture was degassed with nitrogen for 15 minutes. Phenylacetylene (0.176 g, 0.19 ml, 1.72 mmol) was then added by syringe. The tube was sealed and heated in an oil bath to 95° C. while covered with aluminum foil to exclude light (for the duration of the reaction and work up, exposure to light was minimized). The reaction mixture was heated for three hours, and then allowed to cool slowly. The tube contents were dark red with a white precipitate. Upon further cooling, a dark red precipitate formed. TLC analysis with 30% dichlormethane/hexanes showed that all 5-bromo-12-phenylnaphthacene had been consumed. The contents of the reaction tube were transferred to a 250-ml round-bottomed flask, rinsed with dichloromethane, and the solvents were removed by rotary evaporation. The solids were dissolved in 75 ml dichloromethane, and extracted 3 times with 10% aqueous HCl and once with water. Na 2 SO 4 was added to the organic layer and stirred for 30 minutes. The solids were filtered off and the solution transferred to a 250-ml round-bottomed flask. The solvents were removed by rotary evaporation to yield a dark red oil that was dried overnight at room temperature under vacuum. The resulting semi-solid comprised the product (lower R f ) and a reaction by-product, as observed by TLC. This material was purified by silica gel chromatography using 10% dichloromethane/hexanes as eluent. Pure fractions were combined and the solvent was removed by rotary evaporation. After drying under vacuum overnight, the product was obtained as a dark red powder in 65% yield. UV-Vis analysis of the product in THF showed a λ max at 456 nm, 486 nm and 520 nm. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 453 nm, 482 nm and 516 nm. Example 2 Preparation of Additional Disubstituted Naphthacene Dyes Similar dyes were synthesized in exactly the same manner as in Example 1. In step 4, phenylacetylene was substituted with trimethylsilylacetylene (R═(CH 3 ) 3 Si), 1-ethynyl-cyclohexene (R═C 6 H 9 ), or t-butylacetylene (R═C 4 H 9 ). UV-Vis analysis of the product where R is C 6 H 9 using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 451 nm, 481 nm and 515 nm. UV-Vis analysis of the product where R is C 4 H 9 using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 444 nm, 472 nm and 505 nm. Example 3 Synthesis of A Monosubstituted Naphthacene Dye Synthesis of 5-(phenylethynyl)naphthacene 5-Bromonaphthacene (1.00 g, 3.26 mmol, prepared as described in Example 1, Step 1), 31 mg of copper(I) iodide (0.163 mmol), 85 mg of triphenylphosphine (0.33 mmol) and 114 mg of dichlorobis(triphenylphosphine)palladium(II) catalyst (0.163 mmol) were added to an oven-dried glass pressure tube equipped with a magnetic stirrer. Dry triethylamine (20 ml) was added and the mixture was degassed with nitrogen for 15 minutes. Phenylacetylene (0.5 g, 0.46 ml, 4.88 mmol) was then added by syringe. The tube was sealed and heated in an oil bath to 95° C. while covered with aluminum foil to exclude light (for the duration of the reaction and work up, exposure to light was minimized). The reaction mixture was heated for two hours, and then allowed to cool slowly. The tube contents were dark red with a white precipitate. Upon further cooling, a dark red precipitate formed. TLC analysis with 30% dichloromethane/hexanes showed that all 5-bromonaphthacene had been consumed. The contents of the reaction tube were transferred to a 250-ml round-bottomed flask, rinsed with dichloromethane, and the solvents were removed by rotary evaporation. The solids were dissolved in 75 ml dichloromethane and extracted 3 times with 10% aqueous HCl and once with water. Na 2 SO 4 was added to the organic layer and stirred for 30 minutes. The solids were filtered off and the solution was transferred to a 250-ml round-bottomed flask. The solvents were removed by rotary evaporation to yield a dark red oil that was dried overnight at room temperature under vacuum. The resulting semi-solid comprised the product (higher R f ) and a reaction by-product, as seen by TLC. This material was purified by silica gel chromatography using 20% dichloromethane/hexanes as eluent. Pure fractions were combined and the solvent was removed by rotary evaporation. After drying under vacuum overnight, the product was obtained as a dark red powder in 57% yield. UV-Vis analysis of the product at a concentration of 5×10 −5 M in THF showed a λ max at 450 nm, 478 nm and 511 nm. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 446 nm, 474 nm and 507 nm. Example 4 Preparation of Additional Monofunctional Naphthacene Dyes Similar monofunctional dyes were synthesized in exactly the same manner as Example 2 by substituting phenylacetylene with 4-ethynyltoluene (R═CH 3 ) or 1-ethynyl-4-methoxybenzene (R═CH 3 O). UV-Vis analysis of the 4-ethynyltoluene product at a concentration of 5×10 −5 M in THF showed a λ max at 451 nm, 479 nm and 513 nm. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 447 nm, 475 nm and 508 nm. UV-Vis analysis of the 1-ethynyl-4-methoxybenzene product at a concentration of 5×10 −5 M in THF showed a λ max at 451 nm, 480 nm and 515 nm. UV-Vis analysis of the product using HPLC with the product dissolved in 5% dichloromethane/hexanes showed a λ max at 447 nm, 476 nm and 510 nm. Example 5 Spectroscopic Characterization of Photosensitizing Dyes The dyes prepared above were characterized spectroscopically. Commercially available dyes rubrene (2 formulations tested) and BPEN were also characterized for comparison purposes. The λ max for the dyes in THF solvent was determined using a Hewlett-Packard 8452A photodiode array spectrophotometer. The absorption behavior observed in THF closely approximates the absorption behavior achieved in a standard holographic formulation. λ max (nm) Molecular ε 532 nm Dye Structure THF Weight THF HPEN 511.5 328.4 1149 MePEN 513.0 342.4 618 PSiEN 512.0 400.6 1241 MeOPEN 514.5 358.4 1256 PPEN 520.0 404.5 9231 Rubrene 526.0 532.7 11515 BPEN 548.0 428.5 16667 The results shown in the table above thus demonstrate that the dyes of the present invention have λ max values in approximately the same range as the commercially-available rubrene and BPEN, however, the extinction coefficients of the present dyes at 532 nm are substantially lower than that of the commercially-available dyes. Example 6 A 500 μm Layer of Photo-Polymerizable Medium Comprising MeOPEN has Better Recording Sensitivity Compared to a Medium Comprising a Sensitizing Dye of Prior Art A photo-polymerizable medium for holographic recording, comprising a monofunctional naphthacene dye of the present invention for sensitization of Rhodorsil 2074 (Iodoium salt Photo Acid Generator (PAG) with borate anion available from Rhodia Corporation, Inc.) at 532 nm was prepared and compared to a medium comprising BPEN, commercially available from Aldrich Chemical, for sensitizing said PAG in a formulation for a media thickness of 500 microns. A difunctional epoxide monomer compound of Structural Formula (VI) RSi(R 1 ) 2 OSi(R 2 ) 2 R  (VI) where each group R is a 2-(3,4-epoxycyclohexyl)ethyl grouping; each grouping R 1 is a methyl group, and each group R 2 is a methyl group, available from available from Rhodia Corporation, Inc., under the tradename S-200 was added to a diffusable binder 1,3,5-trimethyl-1,1,3,5,5-pentaphenyltrisiloxane commercially available as DowCorning 705 siloxane fluid. Rhodorsil was added to this solution in an amount 6% w/w of the final recording medium and this mixture was stirred at room temperature for 30 minutes to form a uniform solution. To this solution was added a polyfunctional monomer of Structure Formula (VII) and the resulting mixture was stirred for 1 hour to yield a uniform and homogenous solution. To this solution was added either a mono-functional naphthacene dye compound of the structural formula corresponding to MeOPEN in the Table presented for Example (5), in an amount 0.024% w/w of the final recording medium, or BPEN in an amount 0.01% w/w of the final recording medium and the resulting mixtures were stirred overnight at room temperature to yield uniform and homogenous solutions having a compositional ratio of monomer/binder of 71.5:28.5 w/w. The two formulations were coated so as to be sandwiched between two glass slides in a manner that provided for the final thickness of the recording material to be 500 microns. The kinetics and extent of photopolymerization exhibited by the two holographic recording materials were obtained by calorimetric analysis using a Perkin-Elmer DSC-7 Differential Scanning Calorimetry (see Waldman et al., J. Imaging Sci. Technol. 41, (5), pp. 497-514, (1997) ) equipped with a DPS-7 photocalorimetric module and a Crystalaser, Inc. diode pumped solid state (DPSS) frequency doubled Nd:YAG laser, emitting at 532 nm, that was coupled into a multimode fiber having a 200 μm core. In both cases the kinetics of photopolymerization was fast, but for the formulation comprising BPEN the extent of polymermization achieved was lower indicative of being dye limited by comparison to the formulation comprising MeOPEN as the sensitizer. The optical density (OD) was measured with a Perkin-Elmer Lambda9 spectrophotometer for each formulation in a 1 mm path cell. The formulation comprising BPEN, however, had a value for OD that was 25% higher than the value for the formulation comprising MeOPEN. The coatings were subsequently strobe flashed with a Xe strobe lamp to provide for the OD of the coatings to be about the same at the onset of holographic recording. The final OD before holographic recording was 0.11 and 0.10 for the formulations comprising MeOPEN and BPEN, respectively. Co-locational slant fringe plane-wave, transmission holograms were recorded in the conventional manner with a frequency doubled Nd:YAG laser (Coheren Vector) emitting at λ=532 nm using two coherent spatially filtered and collimated laser writing beams directed onto the sample with an interbeam angle of 48.6°. The intensities of the two writing beams were equal at the condition of equal semiangles about the normal, and the total incident intensity for recording was 6.45 mW/cm 2 as measured at the bisecting condition. The sample was mounted onto an optically encoded motorized rotation stage, Model 495 from Newport Corporation, for rotation of φ about the perpendicular to the face of the sample in the interaction plane, and this stage was mounted onto an optically encoded motorized rotation statge, 496B from Newport Corporation, for rotation of θ about the vertical axis denoted as the y-axis. Multiplexed co-locational plane-wave transmission holograms were recorded by combining azimuthal and planar-angle multiplexing (see method of Waldman et al., J. Imaging Sci. Technol. 41, (5), pp. 497-514, (1997) ). Azimuthal multiplexing was carried out via rotations of Δφ about an axis perpendicular to the surface plane of the sample (i.e. z-axis at the condition of equal semiangles for the writing beams) and through the x-y center of the imaged area for a specific value of θ, where θ denotes the rotational position of the sample plane about the y-axis, said axis being perpendicular to the interaction plane. Angle multiplexing was carried out in the standard manner by rotation of Δθ which defines Ω 1 and Ω 2 , the external signal and reference writing beam angles, respectively, and thus the grating angle for the plane-wave holograms. Values of φ were limited to the range of 0°≦φ<180° and Δφ was 1.5°, thus corresponding to 120 co-locational recordings, respectively, for each of the first three grating angle conditions specified by θ having the value of −16°, or −10°, or −4° (counterclockwise rotation) from the bisector condition for the two writing beams. Additionally, a last cycle of 23 holograms was recorded, after a total of 360 were recorded during the first three cycles, by incrementing Δφ by 8° for θ having the value +7.0° (clockwise rotation). The length of the exposure times was controlled via a direct serial computer interface to a Newport mechancial shutter and a schedule was used that ramped exposure times to longer values in monotonic fashion in accordance with the monotonic decline in recording senstivity that is exhibited by the recording material. Reconstruction of the 383 co-locationally multiplexed plane-wave gratings was accomplished by utilization of reading beams that corresponded to the recording beams, but with an incident irradiance, measured at normal incidence to the sample, of 4.0 mW/cm 2 . Diffraction intensity data was obtained for all 383 co-locationally recorded holograms, after completion of the recording of the multiplexed holograms, using two Model 818-SL/CM photodiodes and a Model 2835-C dual channel multi-function optical meter from Newport Corporation. Apertures were placed on the face of the photodiode detectors to ensure that diffraction from only one azimuthal angle condition was detected for each Bragg angle that was interrogated. The read angle was tuned to the optimum Bragg condition (i.e. value for maximum diffraction efficiency) for each θ,φ combination used in the multiplexing sequence by rotation of the media about the y-axis for a given value of φ, and the diffraction efficiency was measured at each Δθ angular increment of 0.005° to 0.01° for each θ,φ combination to obtain accurate Bragg detuning profiles for each multiplexed hologram. The FIGURE shows recording sensitivity in cm/mJ, as determined from the measured values of diffraction efficiency, η i , of each hologram, as a function of cumulative exposure fluence in mJ/cm 2 . Sensitivity in cm/mJ is calculated in the standard manner as (η i 0.5 /I i *t i )/T, where T is thickness of the recording material, t i is the length of the recording time for the ith recording event, and I i is the intensity for the recording event. The recording sensitivity for the holographic recording medium comprising a sensitizer of the present invention (MeOPEN) declined with nonlinear dependence on cumulative recording fluence from a high of about 3.5 to a value of 0.5 cm/mJ after a cumulative exposure fluence of about 100 mJ/cm 2 , whereas for the coating comprising the conventional sensitizer (BPEN) the peak value was only about 1.75 cm/mJ and it declined in nonlinear fashion to a value of about 0.25 cm/mJ at a cumulative exposure fluence of 100 mJ/cm 2 . About 70% of the final cumulative grating strength was attained over the cumulative exposure fluence of 100 mJ/cm 2 for the coating comprising MeOPEN, whereas for the case comprising BPEN only about 50% of the final cumulative grating strength was attained. The enhanced recording sensitivity exhibited by use of a sensitizer of the present invention is more advantageous as the thickness of the recording media is increased further, as the limitations due to low concentration of the dye become more severe. While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

Photosensitizing dyes are often used in conjunction with a photoacid generator in holographic recording media. Conventional photosensitizing dyes typically are limited by having an appreciable absorption of light when used in a sufficient concentration, such that the intensity of light decreases significantly with penetration into a recording medium. The present invention discloses a number of new 5-alkynyl substituted napthacene photosensitizing dyes that have low extinction coefficients coupled with good sensitizing properties, such that the problems associated with the photosensitizing dyes absorbing light are significantly reduced.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to integrated circuits and more particularly to the protection of integrated circuits against so-called “latch-up” phenomena. It applies mainly, but not exclusively, to CMOS-type (Complementary Metal-Oxide Semiconductor) integrated circuit technologies that are particularly sensitive to this phenomenon. 2. Description of the Related Art The latch-up phenomenon manifests itself in an inrush current linked to the triggering of a parasitic thyristor structure inherent in certain integrated circuit technologies, and in particular in the CMOS-type technologies. The MOS transistor-based architectures have parasitic bipolar transistors the gain of which can be very high (50 to 100). Therefore, the parasitic transistors do not disrupt the operation of the circuit, except in certain parasitic thyristor-type configurations (PNPN) in which two parasitic bipolar transistors work in positive feedback, forming a bistable configuration which can be triggered by slight disturbance. Once the feedback is established, the thyristor is in a high conduction state that powers itself even after the disappearance of the disturbance, due to the fact that the thyristor is placed directly in parallel on the power supply. This state can therefore prove destructive for the integrated circuit. Such a parasitic thyristor configuration is shown in FIG. 1 that represents in a cross-section the structure of a CMOS integrated circuit cell, comprising for example a logic gate such as an inverter. The integrated circuit IC cell represented in FIG. 1 , of P-substrate and N-well type, comprises two N- and P-channel MOS transistors, produced in a P−-doped semi-conductive substrate 1 . The P-channel MOS transistor is formed in an N−-doped region 2 of the substrate, referred to as a “well”. The well comprises a drain region 3 , a source region 4 , these regions being P+ doped, and an N+-doped region 5 . The regions 3 , 4 that delimit the channel of the P-channel MOS transistor, are respectively connected to an output 10 of the cell and to the supply terminal Vdd. The region 5 receives the supply voltage Vdd. The N-channel MOS transistor is formed in the substrate 1 by a source region 7 , a drain region 8 , these regions being N+-doped and delimiting the channel of the N-channel MOS transistor, and a P+-doped region 6 connected to the ground. The regions 7 , 8 are respectively connected to the ground terminal and to the output 10 of the cell. Layers 9 , for example in polysilicon, formed above the channels N and P of the two transistors, constitute the gates thereof and are connected to the input 11 of the integrated circuit cell. FIG. 1 also represents, in thinner lines, the position of the parasitic thyristor in relation to the doped regions forming the two transistors MOS. The parasitic thyristor is formed by two bipolar transistors T 1 of pnp-type and T 2 of npn-type, mounted head-to-tail, the collector of one being connected to the base of the other, while the emitters of the two transistors T 1 , T 2 are respectively connected to the supply terminal Vdd and to the ground of the circuit. The emitter-base junction of the transistor T 1 is formed by the association of the P+-doped 4 and N−-doped 2 regions, whereas the collector-base junction of this transistor is formed by the association of the P−-doped substrate 1 and of the N−-doped region 2 . The supply terminal Vdd of the circuit is therefore connected to the emitter of the transistor T 1 , and linked to the base of this transistor through a resistor RN− representing the resistance of the well 2 . The base-emitter junction of the transistor T 2 is formed by the association of the substrate 1 and of the N+-doped region 7 linked to the ground, while the base-collector junction of this transistor is formed by the association of the substrate 1 and of the region 2 . The ground is therefore connected to the base of the transistor T 2 , and linked to the emitter of this transistor through a resistor RP− representing the resistance of the substrate 1 . The parasitic thyristor can be triggered by an overvoltage applied to the power supply of the integrated circuit, a negative voltage or an overvoltage applied to an input and/or output terminal of the integrated circuit, a current injection into an input or output terminal of the integrated circuit, or even by radiations of particles. This triggering produces a strong inrush current between the supply terminals of the integrated circuit, that can cause the destruction of the integrated circuit. The specifications of integrated circuits require a minimum injected current, for example 100 mA at the maximum operating temperature (generally between 70 and 150° C.). The sensitivity of an integrated circuit to the latch-up can be measured by injecting a current into an input or output pin of the integrated circuit, while the latter is powered normally, by detecting an over-consumption of current in the power supply, that can be more or less sudden, and by measuring the intensity of the current injected upon the appearance of the over-consumption. If the over-consumption detected stops at the same time as the current injection, the latch-up is said to be temporary. If, on the contrary, this over-consumption remains even after the current injection has stopped, the latch-up is said to be permanent. A circuit is considered insensitive to latch-up if the latter is only temporary or if a permanent latch-up only appears with an injected current having a high intensity. There are several techniques for reducing the sensitivity of the components to latch-up, i.e., for reducing the performances of the parasitic thyristor and the value of the resistors RN− and RP− of the base of the two parasitic transistors T 1 , T 2 . A first technique involves applying specific routing rules, and particularly adding many N and P bias regions, such as the regions 5 , 6 in FIG. 1 , and increasing the distance between the P- and N-channel MOS transistors. This technique runs counter to the miniaturization of integrated circuits. Another technique involves using epitaxial substrates, so as to reduce the base resistance of one of the two parasitic transistors, i.e., in the example in FIG. 1 , the resistor RP− of the base of the transistor T 2 . This technique involves using more expensive silicon wafers. The base resistance of the transistors T 1 , T 2 can also be reduced using wells made deep in the substrate and highly doped. This technique also contributes to increasing the manufacturing costs, due to the fact that it requires adding or modifying several manufacturing masks of the integrated circuit, and increases the number of manufacturing steps. In addition, the techniques presented above are not always infallible. BRIEF SUMMARY OF THE INVENTION One embodiment of the present invention provides a method for protecting an integrated circuit. The method comprises steps of detecting a latch-up condition, and if a latch-up condition is detected, of modifying a supply voltage parameter of the integrated circuit, to prevent the latch-up from becoming permanently established. According to one embodiment of the present invention, the detection of a latch-up condition comprises a step of detecting a current injection into a connection terminal of the integrated circuit. According to one embodiment of the present invention, the detection of a current injection into a connection terminal of the integrated circuit comprises detecting a positive current injection into the connection terminal. According to one embodiment of the present invention, the detection of a current injection into a connection terminal of the integrated circuit comprises detecting a negative current injection into the connection terminal. According to one embodiment of the present invention, the detection of a current injection into a connection terminal of the integrated circuit comprises detecting a current in a diode formed near the connection terminal. According to one embodiment of the present invention, the detection of a current injection into a connection terminal of the integrated circuit comprises applying a time delay upon the detection of a current injection, and taking the detection of a current injection into account if the current injection is still detected at the end of the time delay. According to one embodiment of the present invention, the detection of a latch-up condition comprises detecting an overvoltage appearing in a power supply connection terminal of the integrated circuit. According to one embodiment of the present invention, the modification of a supply voltage parameter of the integrated circuit comprises cutting off the supply voltage of the integrated circuit while a latch-up condition is present. According to one embodiment of the present invention, the modification of a supply voltage parameter of the integrated circuit comprises stepping down the supply voltage of the integrated circuit while a latch-up condition is present. According to one embodiment of the present invention, the modification of a supply voltage parameter of the integrated circuit comprises supplying the supply voltage of the integrated circuit through a resistor while a latch-up condition is present. One embodiment of the present invention is a device for protecting an integrated circuit. The protection device comprises a latch-up condition detection device for detecting a latch-up condition, and a supply voltage control device for controlling the supply voltage of the integrated circuit, to modify a parameter of the supply voltage of the integrated circuit in order to prevent the latch-up from becoming permanently established. According to one embodiment of the present invention, the latch-up condition detection device comprises a current injection detector circuit for detecting a current injection into a connection terminal of the integrated circuit. According to one embodiment of the present invention, the latch-up condition detection device comprises a negative current injection detector circuit for detecting a negative current injection into a connection terminal of the integrated circuit. According to one embodiment of the present invention, the latch-up condition detection device comprises a positive current injection detector circuit for detecting a positive current injection into a connection terminal of the integrated circuit. According to one embodiment of the present invention, the current injection detector circuit comprises a diode formed near the connection terminal and a measuring circuit for measuring the current passing through the diode. According to one embodiment of the present invention, the latch-up condition detection device comprises, for each connection terminal of the integrated circuit, a detector circuit for detecting a negative current injection into the connection terminal, and/or a detector circuit for detecting a positive current injection into the connection terminal. According to one embodiment of the present invention, the latch-up condition detection device comprises a time delay circuit to take into account a detection of current injection into a connection terminal of the integrated circuit, only if a current injection is still detected at the end of a time delay. According to one embodiment of the present invention, the latch-up condition detection device comprises a detector circuit for detecting an overvoltage appearing in a power supply connection terminal of the integrated circuit. According to one embodiment of the present invention, the supply voltage control device comprises means for cutting off the supply voltage of the integrated circuit while a latch-up condition is present. According to one embodiment of the present invention, the supply voltage control device comprises a voltage step-down transformer for stepping down the supply voltage of the integrated circuit while a latch-up condition is present. According to one embodiment of the present invention, the supply voltage control device comprises a resistor through which the supply voltage is supplied to the integrated circuit while a latch-up condition is present. According to one embodiment of the present invention, the supply voltage control device comprises a voltage regulator that steps down the supply voltage of the integrated circuit to a minimum value while a latch-up condition is present. The present invention also relates to an integrated circuit comprising a protection device as defined above. One embodiment of the present invention is a latch-up condition detection device for detecting a latch-up condition in an integrated circuit. The device comprises a detector circuit for detecting a current injection into a connection terminal of the integrated circuit. According to one embodiment of the present invention, the current injection detector circuit detects a negative current injection. According to one embodiment of the present invention, the current injection detector circuit detects a positive current injection. According to one embodiment of the present invention, the current injection detector circuit comprises a diode formed near the connection terminal and a measuring circuit for measuring the current passing through the diode. According to one embodiment of the present invention, the detection device comprises for each connection terminal of the integrated circuit, a detector circuit for detecting a negative current injection into the connection terminal, and/or a detector circuit for detecting a positive current injection into the connection terminal. According to one embodiment of the present invention, the detection device comprises a time delay circuit to take into account a detection of current injection into a connection terminal of the integrated circuit, only if a current injection is still detected at the end of a time delay. According to one embodiment of the present invention, the detection device comprises a detector circuit for detecting an overvoltage appearing in a power supply connection terminal of the integrated circuit. The present invention also relates to an integrated circuit comprising a detection device as defined above. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS These and other features and advantages of the present invention will be explained in greater detail in the following description of embodiments of the present invention, given in relation with, but not limited to the following figures, in which: FIG. 1 already described represents in a cross-section an integrated circuit in which a latch-up is likely to occur, FIG. 2 represents in block form an integrated circuit equipped with a protection device according to the present invention, FIG. 3 represents in block form a latch-up condition detection device of the protection device according to the present invention, FIG. 4 is a wiring diagram of a detector circuit according to the present invention, for detecting a negative current injection on a connection terminal of the integrated circuit, FIG. 5 is an equivalent wiring diagram of the detector circuit represented in FIG. 4 , FIG. 6 is a simplified partial top view of the integrated circuit equipped with a detection means of the circuit represented in FIG. 4 , FIG. 7 is a wiring diagram of a detector circuit according to the present invention, for detecting a positive current injection on a connection terminal of the integrated circuit, FIG. 8 is an equivalent wiring diagram of the detector circuit represented in FIG. 6 , FIG. 9 is a simplified partial top view of the integrated circuit equipped with a detection means of the circuit represented in FIG. 7 , FIG. 10 is a wiring diagram of a detector circuit according to the present invention, for detecting an overvoltage on a power supply terminal of the integrated circuit, FIG. 11 represents in block form an alternative embodiment of the detection device represented in FIG. 3 , FIG. 12 is a wiring diagram of a time delay circuit of the detection device represented in FIG. 11 , FIGS. 13 to 16 are wiring diagrams of several embodiments of supply voltage control circuits for controlling the supply voltage of the integrated circuit, of the protection device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 2 represents an integrated circuit IC comprising input and/or output connection terminals P 1 , P 2 , . . . , Pn and a power supply connection terminal VDD of the integrated circuit. According to one embodiment of the present invention, the integrated circuit IC comprises a latch-up protection device LUP. The device LUP comprises a device LUDC for detecting latch-up generating conditions and a supply voltage control circuit PMC for controlling the supply voltage Vdd of the integrated circuit. The device LUDC supplies a detection signal LU that is used by the circuit PMC to control the supply voltage Vdd supplied to the other functions of the integrated circuit. FIG. 3 represents a detection device LUDC according to one embodiment of the present invention, supplying the integrated circuit IC with a detection signal LU of at least one latch-up generating condition. The detection device LUDC comprises a positive current injection detector circuit PCID and/or a negative current injection detector circuit NCID, connected to each connection terminal of the set of input and/or output connection terminals P 1 -Pn of the integrated circuit IC, and/or an overvoltage detector circuit OVD connected to the power supply connection terminal VDD of the integrated circuit. The device LUDC comprises NAND gate AG 1 connected to the outputs of the circuits NCID, PCID and OVD. The output of the gate AG 1 supplies the detection signal LU. The detector circuit LUDC is powered by a voltage Vdd 1 coming directly from the power supply connection terminal VDD of the integrated circuit IC. If no latch-up condition is detected, all the signals applied at input of the gate AG 1 are on 1, and therefore the output signal of the device LUDC is on 0. On the contrary, if at least one signal at input of the gate AG 1 is on 0, the signal LU is on 1 indicating that a latch-up condition of the integrated circuit has been detected. FIG. 4 represents a detector circuit for detecting a negative current injection NCID into a connection terminal Pi of an integrated circuit. It is generally possible to inject a current that is negative in relation to the ground through an N+-doped region formed in a P substrate, and connected to the ground, for example the region 7 in the diagram in FIG. 1 . Such a region forms a parasitic diode D 1 reverse-connected between the connection terminal Pi of the integrated circuit and the ground. In addition, the diode D 1 is sometimes added to provide ESD protection (electrostatic discharge) in the event that the terminal Pi forms an input and/or output or a supply terminal of the integrated circuit. In FIG. 4 , the detector circuit NCID comprises a reverse-mounted diode D 2 disposed near the diode D 1 . The anode of the diode D 2 is connected to the ground. The cathode of the diode D 2 is connected to the input of an inverter comprising a P-channel MOS transistor MP 1 and an N-channel MOS transistor MN 1 , and is linked to the power supply source Vdd 1 of the integrated circuit through a resistor R 1 . The input of the inverter is connected to the gates of the transistors MP 1 and MN 1 . The source of the transistor MP 1 receives the supply voltage Vdd 1 . The source of the transistor MN 1 is connected to the ground. The drains of the transistors MP 1 and MN 1 are connected to the input of another inverter I 1 the output of which is the output of the circuit NCID that supplies a detection signal of a negative current injection LU 1 . The circuit NCID in FIG. 4 is equivalent to the circuit represented in FIG. 5 . In the circuit in FIG. 5 , the diodes D 1 and D 2 have been replaced by an NPN-type bipolar transistor T 3 equivalent to the diodes D 1 , D 2 . The emitter of the transistor T 3 is connected to the connection terminal Pi, the base of the transistor T 3 is grounded, and the collector of the transistor T 3 is connected to the resistor R 1 and to the gates of the transistors MP 1 and MN 1 . In other words, the diodes D 1 and D 2 are sufficiently near one another to form the junctions NP and PN of a bipolar transistor. The diode D 2 that is thus added to detect a current injection, forms the collector-base junction of the transistor T 3 , while the diode D 1 forms the emitter-base junction of the transistor T 3 . The intensity of the current Ic circulating in the collector of the transistor T 3 , i.e., in the detection diode D 2 , varies according to the total current injected into the ground of the substrate of the integrated circuit by the connection terminal Pi. The law of variation of the intensity of the current Ic depends on the gain of the transistor T 3 , and in particular on the distance between the collector and the point of injection of the current, and on the shape and the dimensions of the collector. Due to these distance, shape and dimensional characteristics (lateral bipolar transistor with a long base zone), the gain of the transistor T 3 is typically lower than 1. The value of the resistor R 1 is chosen according to the current intensity threshold to be detected. Typically, the value of the resistor R 1 is of a few kilo-Ohms. The transistors MP 1 and MN 1 are preferably designed so that the W/L ratio (channel width-to-length ratio) of the transistor MP 1 is clearly greater than the ratio of the transistor MN 1 . Thus, the inverter made up of the transistors MP 1 and MN 1 switches when its input voltage is lower than or equal to Vdd 1 −Vtp, Vtp being the threshold voltage of the transistor MP 1 . The detection signal LU 1 at output of the circuit NCID, normally on 1, thus goes to 0 if the following relation is confirmed: R 1· Ic≧|Vtp|   (1) i.e., if the current Ic collected by the diode D 2 is greater than or equal to Vtp/R 1 . Without this dimensioning constraint of the transistors MP 1 and MN 1 , the switching threshold of the inverter made up of the transistors MP 1 and MN 1 depends on the voltage Vdd. The notion of proximity of the diodes D 1 and D 2 is shown in FIG. 6 which represents in a top view a portion of the active face of the integrated circuit IC comprising the connection terminal Pi. The connection terminal Pi is produced by metallization 11 forming a contact pad deposited on the active face of the integrated circuit IC, and connected to at least one highly N+-doped region 12 . In FIG. 6 , the contours of the contact pad Pi correspond to a zone of the active face of the integrated circuit not covered by a passivation insulator. The connection zone 13 of the zone 12 doped by the metallization 11 is linked to the latter by a plurality of contacts 15 , particularly so as to enable a high current density. The interface between the doped zone 12 and the P doping substrate, forms the diode D 1 that is connected to the contact pad Pi. The diode D 2 is produced near the diode D 1 by forming an N+-doped region 14 , and by forming contacts 16 so as to be able to connect the diode to the rest of the circuit. The distance between the diodes D 1 and D 2 is determined according to the duration of the current injection to be detected and to the speed of propagation of the loads thus injected into the integrated circuit. FIG. 7 represents a detector circuit PCID for detecting a positive current injection into a connection terminal Pi of the integrated circuit. It is generally possible to inject a current that is positive in relation to the supply voltage Vdd 1 through a P+-doped region formed in an N-well, and connected to the supply voltage source, for example the region 4 in the diagram in FIG. 1 . Such a region forms a parasitic diode D 3 reverse-connected between the connection terminal Pi of the integrated circuit and the power supply source Vdd 1 . In addition, the diode D 3 is also sometimes added to provide ESD protection in the event that the terminal Pi forms an output of the integrated circuit. As in the circuit NCID represented in FIG. 4 , the detector circuit PCID in FIG. 7 comprises a reverse-mounted diode D 4 disposed near the diode D 3 . The anode of the diode D 4 receives the supply voltage Vdd 1 . The cathode of the diode D 4 is connected to the input of an inverter comprising a P-channel MOS transistor MP 2 and an N-channel MOS transistor MN 2 , and linked to the ground through a resistor R 2 . The input of the inverter is connected to the gates of the transistors MP 2 and MN 2 . The source of the transistor MN 2 is connected to the ground. The source of the transistor MP 2 receives the supply voltage Vdd 1 . The drains of the transistors MP 2 and MN 2 supply at output of the circuit PCID a positive current injection detection signal LU 2 . The circuit PCID in FIG. 7 is equivalent to the circuit represented in FIG. 8 . In the circuit in FIG. 8 , the diodes D 3 and D 4 have been replaced by a bipolar transistor T 4 of equivalent PNP type, the emitter of which is connected to the connection terminal Pi, the base of which receives the supply voltage Vdd 1 , and the collector of which is connected to the resistor R 2 and to the gates of the transistors MP 2 and MN 2 . In other words, the diodes D 3 and D 4 are sufficiently near one another to form junctions PN and NP of a bipolar transistor. The diode D 4 that is thus added to detect a current injection, forms the collector-base junction of the transistor T 4 , while the diode D 3 forms the emitter-base junction of the transistor T 4 . The intensity of the current Ic circulating in the collector of the transistor T 4 , i.e., in the detection diode D 4 , varies according to the total current injected into the well of the integrated circuit by the connection terminal Pi. The law of variation of the intensity of the current Ic depends on the distance between the collector and the point of injection of the current, and on the shape and the dimensions of the collector. Due to these distance, shape and dimensional characteristics, the gain of the transistor T 4 is typically lower than 1. The value of the resistor R 2 is chosen according to the current intensity threshold to be detected. Typically, the value of the resistor R 2 is of a few kilo-Ohms. The transistors MP 2 and MN 2 are preferably designed so that the W/L ratio (channel width-to-length ratio) of the transistor MN 2 is clearly greater than the ratio of the transistor MP 2 . Thus, the inverter made up of the transistors MP 2 and MN 2 switches when its input voltage is greater than or equal to Vtn, Vtn being the threshold voltage of the transistor MN 2 . The detection signal LU 2 at output of the circuit PCID, normally on 1, thus goes to 0 if the following relation is confirmed: R 2· Ic≧Vtn   (2) i.e., if the current Ic collected by the diode D 4 is greater than or equal to Vtn/R 2 . Without this dimensioning constraint of the transistors MP 2 and MN 2 , the switching threshold of the inverter made up of the transistors MP 2 and MN 2 depends on the voltage Vdd. The notion of proximity of the diodes D 3 and D 4 is shown in FIG. 9 which represents in a top view a portion of the active face of the integrated circuit IC comprising the connection terminal Pi. The connection terminal Pi is produced by metallization 21 forming a contact pad deposited on the active face of the integrated circuit IC. The metallization 21 is connected to at least one highly P+-doped region 22 formed in an N-doped well 27 . In FIG. 9 , the contours of the contact pad Pi correspond to a zone of the active face of the integrated circuit not covered by a passivation insulator. The connection zone 23 of the zone 22 doped by the metallization 21 is linked to the latter by a plurality of contacts 25 , particularly so as to enable a high current density. The interface between the doped zone 22 and the well 27 forms the diode D 3 that is connected to the contact pad Pi. The diode D 4 is produced near the diode D 3 , by forming a highly P+-doped region 24 in the well 27 , and by producing contacts 26 so as to be able to connect the diode to the rest of the circuit. The distance between the diodes D 3 and D 4 is determined according to the duration of the current injection to be detected and to the speed of propagation of the loads thus injected into the integrated circuit. It shall be noted that it is possible for the contact pads Pi of the integrated circuit IC to be associated only with a positive PCID or negative NCID current injection detector circuit depending on the configuration of the contact pad. In particular, if the contact pad Pi is only connected to an N+-doped region formed in the substrate, the pad Pi is only associated with a circuit NCID. If the contact pad Pi is only connected to a P+-doped region formed in an N-doped well, the pad Pi is only associated with a circuit PCID. Finally, if the contact pad Pi is connected to a P+-doped region formed in the substrate, and to a P+-doped region formed in an N-doped well, the contact pad is associated with both a circuit NCID and a circuit PCID. FIG. 10 represents a detector circuit for detecting overvoltages OVD in a power supply connection terminal VDD of the integrated circuit IC. The circuit OVD comprises several diode-mounted MOS transistors MN 4 (gate connected to the source) arranged in series between the connection terminal VDD and the ground through a resistor R 3 . The drain of the transistor connected to the resistor R 3 is also connected to the input of an inverter comprising a P-channel MOS transistor MP 3 and an N-channel MOS transistor MN 3 . The input of the inverter is connected to the gates of the transistors MP 3 and MN 3 . The source of the transistor MN 3 is connected to the ground. The source of the transistor MP 3 receives the supply voltage Vdd. The drains of the transistors MP 3 and MN 3 supply a detection signal LU 3 at output of the circuit OVD. The transistors MN 4 and the transistor MN 3 determine a threshold voltage Vs above which the inverter made up of the transistors MP 3 and MN 3 switches and supplies a detection signal LU 3 , normally on 1, that changes to 0. The threshold voltage Vs is approximately equal to n+1 times the threshold voltage Vtn of an N-channel MOS transistor, n being the number of transistors MN 4 arranged in series (Vs=(n+1).Vtn). FIG. 11 represents an alternative embodiment of the detection device LUDC according to the present invention. Compared to the device represented in FIG. 3 , the detection device LUDC represented in FIG. 11 comprises, in addition, a time delay circuit TFCT connected to the output of the gate AG 1 , an inverter I 2 connected to the output of the circuit TFCT, and a NAND logic gate AG 2 connected to the output of the inverter I 2 . The output of the gate AG 2 supplies the detection signal LU. In addition, the output of the circuit OVD is connected, not to an input of the gate AG 1 , but to another input of the gate AG 2 . In certain applications, transient current injections can occur and should not be considered to be latch-up conditions. Indeed, some of these conditions such as the injection of current into input and/or output terminals of the integrated circuit do not immediately generate a latch-up, due to the diffusion time of the minority loads transmitted from the diode D 1 (or D 3 ) to the detector circuit, which can be 200 μm from the diode. The circuit TFCT inserted at the output of the gate AG 1 enables these transient conditions not to be detected. In other words, the changes to 0 of the signals LU 1 and LU 2 that have a shorter duration than the time delay of the circuit TFCT are not taken into account to modify the supply voltage Vdd 1 of the integrated circuit. On the other hand, overvoltages in the supply voltage Vdd 1 very rapidly generate a breakdown by local avalanche multiplication effect. That is why the detection signal LU 3 coming from the circuit OVD is immediately taken into account downstream from the circuit TFCT. The duration of the time delay is chosen according to the distance between the connection terminal Pi and the detection diode D 2 , D 4 , to the distance in relation to the connection terminal Pi of the components to be protected of the integrated circuit, and to the speed of propagation of the loads in the substrate or in the well. In other words, the duration of the time delay, and the distance between the detection diode and the connection terminal determine the size of the protected zone of the integrated circuit around the connection terminal Pi. The longer the duration of the time delay is or the further the detection diode is from the connection terminal, the more the injected current propagates in the integrated circuit before a modification is applied to the supply voltage Vdd of the integrated circuit IC. FIG. 12 represents an example of a time delay circuit TFCT. The circuit TFCT comprises a circuit RC, an inverter I 3 connected between an input In of the circuit TFCT and the circuit RC, and a Schmitt trigger connected between the circuit RC and an output Out of the circuit TFCT. The circuit RC comprises a resistor R 4 comprising a first terminal connected to the output of the inverter I 3 , and a capacitor C 1 connected between a second terminal of the resistor R 2 and the ground. The Schmitt trigger comprises two P-channel MOS transistors MP 5 , MP 6 , and two N-channel MOS transistors MN 5 , MN 6 . The gates of the transistors MP 5 , MP 6 , MN 5 , MN 6 are connected to the second terminal of the resistor R 4 and to the capacitor C 1 . The source of the transistor MP 6 receives the supply voltage Vdd 1 . The source of the transistor MN 6 is connected to the ground. The Schmitt trigger also comprises a transistor MP 7 the source of which is connected to the drain of the transistor MP 6 and to the source of the transistor MP 5 , and a transistor MN 7 the source of which is connected to the source of the transistor MN 5 and to the drain of the transistor MN 6 . The drains of the transistors MP 5 and MN 5 are connected to the output Out of the circuit TFCT and to the gates of the transistors MP 7 and MN 7 . The time constant of the circuit TFCT is in the order of R 4 .C 1 , and depends on the hysteresis of the Schmitt trigger. It shall be noted that if the device LUDC detects successively and without discontinuity several temporary injections of current, the device will indicate a latch-up detection, despite the presence of the time delay circuit TFCT. FIG. 13 represents a first embodiment of a control circuit for controlling the supply voltage of the integrated circuit. The circuit PMC 1 represented in FIG. 13 comprises a P-channel MOS transistor MP 8 operating like a switch connected between the connection terminal VDD and the supply voltage input Vdd of the integrated circuit. The transistor MP 8 is controlled by the output signal LU of the detector circuit LUDC. As soon as a latch-up condition is detected (signal LU on 1), the transistor MP 8 cuts off the power supply of the integrated circuit IC. As soon as this condition disappears (signal LU on 0), the transistor MP 8 restores the power supply of the integrated circuit. FIG. 14 represents a second embodiment of a control circuit for controlling the supply voltage of the integrated circuit. Compared to the circuit PMC 1 , the circuit PMC 2 represented in FIG. 14 comprises, in addition, a resistor R 5 connected between the drain and the source of the transistor MP 8 . As soon as a latch-up condition is detected (signal LU on 1), the transistor MP 8 goes off. The supply voltage Vdd is then supplied to the integrated circuit IC through the resistor R 5 . As soon as this condition disappears (signal LU on 0), the transistor MP 8 short-circuits the resistor R 5 and the integrated circuit then directly receives the supply voltage Vdd 1 as supplied to the power supply connection terminal VDD (Vdd=Vdd 1 ). FIG. 15 represents a third embodiment of a control circuit for controlling the supply voltage of the integrated circuit. Compared to the circuit PMC 2 , the circuit PMC 3 represented in FIG. 15 comprises, instead of the resistor R 5 , several diode-mounted N-channel MOS transistors MN 8 arranged in series (three transistors MN 8 in the example in FIG. 15 ). As soon as a latch-up condition is detected (signal LU on 1), the transistor MP 8 goes off. The supply voltage Vdd is then supplied to the integrated circuit IC through the transistors MN 8 that step down the voltage Vdd of the threshold voltage Vtn of an N-channel transistor, multiplied by the number n of transistors MN 8 (Vdd=Vdd 1 −n.Vtn). As soon as this condition disappears (signal LU on 0), the transistor MP 8 short-circuits the transistors MN 8 and the integrated circuit then receives the supply voltage Vdd 1 as supplied to the power supply connection terminal VDD (Vdd=Vdd 1 ). FIG. 16 represents a fourth embodiment of a control circuit for controlling the supply voltage of the integrated circuit. The circuit PMC 4 represented in FIG. 16 comprises a voltage regulator VREG interposed between the connection terminal VDD and the supply voltage input Vdd of the integrated circuit. The regulator VREG is controlled by the detection signal LU. As soon as a latch-up generating condition is detected (signal LU on 1), the voltage regulator VREG is designed to step down the supply voltage Vdd to a minimum value. Certain integrated circuits are equipped with such a voltage regulator. The embodiment in FIG. 16 in fact provides for using the presence of such a voltage regulator to adjust the supply voltage of the integrated circuit to a minimum value when a latch-up condition is detected. It will be understood by those skilled in the art that various alternative embodiments and applications of the present invention are possible. Thus, the present invention is not limited to an integrated circuit comprising both a latch-up condition detection device and a supply voltage control device for controlling the supply voltage of the integrated circuit. Indeed, the integrated circuit may comprise a latch-up condition detection device without any supply voltage control device, and supply the external environment with the detection signal LU that is taken into account by the external power supply of the integrated circuit. Furthermore, the latch-up condition detection function can be produced without detecting any overvoltages on the power supply connection terminal of the integrated circuit, such that providing an overvoltage detector circuit OVD is optional.

Device for protecting an integrated circuit, comprising a device for detecting a latch-up condition, and a supply voltage control device for controlling a supply voltage of the integrated circuit, to modify a parameter of the supply voltage of the integrated circuit in order to prevent the latch-up from becoming permanently established.

BACKGROUND OF INVENTION [0001] Disc drill bits are one type of drill bit used in earth drilling applications, particularly in petroleum or mining operations. In such operations, the cost of drilling is significantly affected by the rate the disc drill bit penetrates the various types of subterranean formations. That rate is referred to as rate of penetration (“ROP”), and is typically measured in feet or inches per hour. As a result, there is a continual effort to optimize the design of disc drill bits to more rapidly drill specific formations and reduce these drilling costs. [0002] Disc drill bits are characterized by having disc-shaped cutter heads rotatably mounted on journals of a bit body. Each disc has an arrangement of cutting elements attached to the outer profile of the disc. Disc drill bits can have three discs, two discs, or even one disc. An example of a three disc drill bit 101 , shown in FIG. 1A , is disclosed in U.S. Pat. No. 5,064,007 issued to Kaalstad (“the '007 Patent”), and. incorporated herein by reference in its entirety. Disc drill bit 101 includes a bit body 103 and three discs 105 rotatably mounted on journals (not shown) of bit body 103 . Discs 105 are positioned to drill a generally circular borehole 151 in the earth formation being penetrated. Inserts 107 are arranged on the outside radius of discs 105 such that inserts 107 are the main elements cutting borehole 151 . Furthermore, disc drill bit 101 includes a threaded pin member 109 to connect with a threaded box member 111 . This connection enables disc drill bit 101 to be threadably attached to a drill string 113 . [0003] In this patent, inserts 107 on discs 105 are conically shaped and used to primarily generate failures by crushing the earth formation to cut out wellbore 151 . During drilling, a force (referred to as weight on bit (“WOB”)) is applied to disc drill bit 101 to push it into the earth formation. The WOB is translated through inserts 107 to generate compressive failures in the earth formation. In addition, as drill string 113 is rotated in one direction, as indicated by arrow 131 , bit body 103 rotates in the same direction 133 as drill string 113 , which causes discs 105 to rotate in an opposite direction 135 . [0004] Referring now to FIG. 1B , another type of disc drill bit, as disclosed in U.S. Pat. No. 5,147,000 also issued to Kaalstad (“the '000 Patent”) incorporated herein by reference in its entirety, is shown. The '000 Patent discloses a similar three disc drill bit to that of the '007 Patent, but instead shows another arrangement of the inserts on the discs of the disc drill bit. In FIG. 1B , inserts 123 are disposed on the face of discs 125 , instead of on the outside radius. The primary function of inserts 123 is to cut out the borehole by generating compressive failures from WOB. After inserts 123 generate the primary compressive failures, they then perform a secondary function of excavating the compressively failed earth. The conical shape and location of inserts 123 on disc drill bit 121 are effective for generating compressive failures, but are inadequate in shape and location to excavate the earth formation also. When used to excavate the earth formation from the compressive failures, inserts 123 wear and delaminate very quickly. [0005] Although disc bits have been used successfully in the prior art, further improvements in the drilling performance may be obtained by improved cutting configurations. SUMMARY OF THE INVENTION [0006] In one aspect, the present invention relates to a drill bit. The drill bit includes a bit body and a journal depending from the bit body. The drill bit further includes a disc rotatably mounted on the journal and PDC cutting elements disposed on the disc. [0007] In another aspect, the present invention relates to a cutting structure to be used with a disc drill bit. The cutting structure includes a shearing portion arranged in a shearing configuration, wherein the shearing portion comprises PDC. The cutting structure further includes a compressive portion arranged in a compressive configuration. The shearing portion and the compressive portion of the cutting structure are formed into a single body. [0008] In another aspect, the present invention relates to a method of designing a drill bit, wherein the drill bit includes a bit body, a journal depending from the bit body, a disc rotatably mounted to the bit body, first radial row of cutting elements, and second radial of row cutting elements. The method includes identifying a relative velocity of the drill bit, and determining a compressive configuration of the first radial row of cutting elements based on the relative velocity. The method further includes determining a shearing configuration of the second radial row cutting elements based on the relative velocity of the drill bit. Then, the first radial row cutting elements are arranged on the disc of the drill bit based on the compressive configuration, and the second radial row cutting elements are arranged on the disc of the drill bit based on the shearing configuration. [0009] Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS [0010] FIG. 1A shows an isometric view of a prior art three disc drill bit. [0011] FIG. 1B shows a bottom view of a prior art three disc drill bit. [0012] FIG. 2A shows an isometric view of a disc drill bit in accordance with an embodiment of the present invention. [0013] FIG. 2B shows an isometric view of the bottom of the disc drill bit of FIG. 2A . [0014] FIG. 3A shows a schematic view of a prior art disc drill bit. [0015] FIG. 3B shows a schematic view of a prior art disc drill bit. [0016] FIG. 4 shows an isometric view of a prior art PDC bit. [0017] FIG. 5 shows a bottom view of a disc drill bit in accordance with an embodiment of the present invention. [0018] FIG. 6 shows a bottom view of the disc drill bit of FIG. 5 . [0019] FIG. 7 shows an isometric view of a cutting structure in accordance with an embodiment of the present invention. [0020] FIG. 8A shows a bottom view of a disc drill bit in accordance with an embodiment of the present invention. [0021] FIG. 8B shows a bottom view of the disc drill bit of FIG. 8A . [0022] FIG. 9A shows an isometric view of a disc drill bit in accordance with an embodiment of the present invention. [0023] FIG. 9B shows an isometric view of the disc drill bit of FIG. 9A . [0024] FIG. 9C shows an isometric view of the disc drill bit of FIGS. 9A and 9B . [0025] FIG. 10A shows an isometric view of a disc drill bit in accordance with an embodiment of the present invention. [0026] FIG. 10B shows an isometric view of the disc drill bit of FIG. 10A . DETAILED DESCRIPTION [0027] As used herein, “compressive configuration” refers to a cutting element that primarily generates failures by crushing the earth formation when drilling. [0028] As used herein, “shearing configuration,” refers to a cutting element that primarily generates failures by shearing the earth formation when drilling. [0029] In one or more embodiments, the present invention relates to a disc drill bit having at least one disc and at least one cutting element disposed on the disc to be oriented in a either a compressive configuration or a shearing configuration. More particularly, the cutting element oriented in either configuration can be made of polycrystalline diamond compact (“PDC”). The compact is a polycrystalline mass of diamonds that are bonded together to form an integral, tough, high-strength mass. An example of a PDC cutter for drilling earth formation is disclosed in U.S. Pat. No. 5,505,273, and is incorporated herein by reference in its entirety. [0030] Referring now to FIG. 2A , a disc drill bit 201 in accordance with an embodiment of the present invention is shown. Disc drill bit 201 includes a bit body 203 having one or more journals (not shown), on which one or more discs 205 are rotatably mounted. Referring now to FIG. 2B , an enlarged view of disc drill bit 201 is shown. Disposed on at least one of discs 205 of disc drill bit 201 are a first radial row 207 of cutting elements and a second radial row 209 of cutting elements. First radial row 207 of cutting elements are located closer to an axis of rotation 202 of disc drill bit 201 than second radial row 209 of cutting elements. Thus, extending radially out from axis of rotation 202 , first radial row 207 of cutting elements come before second radial row 207 of cutting elements. First radial row 207 of cutting elements and second radial row 209 of cutting elements act together to drill a borehole with a radius at which second radial row 209 of cutting elements extend from the axis of rotation of the disc drill bit. First radial row 207 of cutting elements penetrate into the earth formation to form the bottom of the borehole, and second radial row 209 of cutting elements shear away the earth formation to form the full diameter of the borehole. In this particular embodiment, each cutting element of second radial row 209 is configured into a single cutting structure 211 with a corresponding cutting element of first radial row 207 . FIG. 7 shows a similar cutting structure to that of cutting structure 211 . Cutting elements of first radial row 207 are arranged about the outside radius of discs 205 such that cutting elements of first radial row 207 are in a compressive configuration. Also, cutting elements of second radial row 209 are disposed on the face of discs 205 such that cutting elements of second radial row 209 are in a shearing configuration. [0031] In some embodiments, cutting elements of the first radial row are oriented in the compressive configuration may be comprised of tungsten carbide, PDC, or other superhard materials, and may be diamond coated. Cutting elements of the first radial row are designed to compress and penetrate the earth formation, and may be of conical or chisel shape. The second radial row cutting elements have PDC as the cutting faces, which contact the earth formation to cut out the borehole. Also, cutting elements of the second radial row are oriented to shear across the earth formation. [0032] Because the cutting elements of the first radial row on the discs of the disc drill bit are in a compressive configuration, the cutting elements primarily generate failures by crushing the earth formation when drilling. Additionally, because the cutting elements of the first radial row are more suited to compressively load the earth formation, significant shearing of the earth formation by the cutting elements of the first radial row should be avoided. Too much shearing may prematurely wear and delaminate the cutting elements of the first radial row. To arrange the cutting elements of the first radial row in a compressive configuration, the cutting elements should be oriented on the disc drill bit to have little or no relative velocity at the point of contact with respect to borehole. If the cutting elements of the first radial row have no relative velocity with the point of contact of the borehole, the cutting elements will generate compression upon the earth formation with minimal shearing occurring across the borehole. [0033] Referring now to FIG. 8A , a relative velocity 855 of cutting elements of first radial row 207 and the components making up relative velocity 855 with respect to the borehole, is shown. Relative velocity 855 at the point of contact of cutting elements of first radial row 207 is made from two corresponding velocities. The first contributing velocity is bit body velocity 851 , the velocity of the cutting element of first radial row 207 from the rotation of the bit body. Bit body velocity 851 is the product of rotational speed of the bit body, ω bit , and distance of the cutting element of the first radial row from the axis of rotation of the bit body, R bit . The second contributing velocity is disc velocity 853 , the velocity of the cutting element of first radial row 207 from the rotation of the discs. Disc velocity 853 is the product of rotational speed of the of the disc, ω disc , and distance of the cutting element of the first radial row from the axis of rotation of the disc, R disc . Relative velocity 855 , V first radial row , is the sum of bit body velocity 851 and disc velocity 853 , and is shown below: V firstradialrow =(ω bit ×R bit )+(ω disc ×R disc )   [Eq. 1] [0034] When the bit body is in one direction of rotation, the disc is put into an opposite direction of rotation. If such values are inserted into the formula then, either the value ω disc or the value ω bit would be negative. As cutting elements of first radial row 207 on the disc then passes through a contact point 871 with the borehole, the two corresponding velocity components, bit body velocity 851 and disc velocity 853 , can be of equal magnitude and cancel out one another, resulting in a relative velocity of zero for V first radial row . With little or no relative velocity then, the cutting elements of first radial row 207 located at contact point 871 would therefore generate almost entirely compressive loading upon the earth formation with minimal shearing occurring across the borehole. Thus, the cutting elements of the first radial row should be designed to contact and compress the borehole most at contact point 871 . When the cutting elements of the first radial row can no longer maintain little or no relative velocity, they should disengage with the earth formation to minimize shearing action. With the determination of the direction of the relative velocity, the compressive configuration can be optimized to improve the compressive action of the cutting elements of the first radial row. [0035] In contrast to cutting elements of first radial row 207 , cutting elements of second radial row 209 are oriented to use the relative velocity to improve their shearing cutting efficiency. Referring still to FIG. 8A , a relative velocity 855 of cutting elements of second radial row 209 is made up of the same two corresponding velocities, bit body velocity 851 and disc velocity 853 , as discussed above. Because cutting elements of first radial row 207 and cutting elements of second radial row 209 are located closely together, relative velocity 855 of cutting elements of first radial row 207 and cutting elements of second radial row 209 at points 871 and 873 are similar. Cutting efficiency of cutting elements of second radial row 209 improves if the shear cutting action occurs in the direction of relative velocity 855 . Contact point 873 shows relative velocity 855 of cutting elements of second radial row 209 . When cutting elements of second radial row 209 are oriented to shear in the direction of relative velocity 855 , as shown, the shearing cutting efficiency is improved. With the determination of the direction of the relative velocity, the shearing configuration can be optimized to improve the shearing action of the cutting elements of the second radial row. [0036] Referring now to FIG. 8B , another view of the embodiment of the present invention of FIG. 8A is shown. FIG. 8B depicts two zones 891 , 893 of the cutting action from the disc drill bit. Compressive zone 891 is the zone which allows first radial row 207 of cutting elements to most effectively generate compressive failures. Contact point 871 , which minimizes relative velocity of first radial row 207 of cutting elements, is located in the compressive zone 891 . Shearing zone 893 is the zone which allows second radial row 209 of cutting elements to most efficiently generate shearing failures. Contact point 873 , which has a high relative velocity for shearing of second radial row 209 of cutting elements, is located in shearing zone 893 . [0037] In one or more embodiments of the present invention, the discs in the disc drill bit may be positively or negatively offset from the bit body. Referring now to FIGS. 3A & 3B , examples of negative and positive offset in a prior art disc drill bit 301 are shown. Disc drill bit 301 includes a bit body 303 having a journal (not shown), on which a disc 305 is rotatably mounted. Inserts 307 are arranged on the outside radius of disc 305 . Disc drill bit 301 further includes a center axis 311 of rotation of bit body 303 offset from an axis 313 of rotation of disc 305 . Bit body 303 rotates in one direction, as indicated in the figures, causing disc 305 to rotate in an opposite direction when cutting a borehole 331 . Referring specifically to FIG. 3A , axis 313 of rotation of disc 305 is offset laterally backwards in relation to the clockwise rotation of bit body 303 , showing disc drill bit 301 as negatively offset. Referring specifically to FIG. 3B , axis 313 of rotation of disc 305 is offset laterally forwards in relation to the clockwise rotation of bit body 303 , showing disc drill bit 301 as positively offset. [0038] The positive and negative offset of the discs ensures that only an appropriate portion of the PDC cutting elements and inserts are cutting the borehole at any given time. If -the entire surface of the disc was effectively drilling the borehole, the discs and drill would be prone to stalling in rotation. The offset arrangement of the discs assures that only a selected portion of the disc is cutting. Also, offsets force the discs to shear while penetrating the earth formation. The present invention is particularly well adapted to be used with negative offset. [0039] Referring now to FIG. 5 , another disc drill bit 501 in accordance with an embodiment of the present invention is shown. Disc drill bit 501 includes a bit body 503 having one or more journals (not shown), on which one or more discs 505 are rotatably mounted. Disposed on at least one of discs 505 of disc drill bit 501 are first radial row 507 of cutting elements and second radial row 509 of cutting elements. In this embodiment, cutting elements of second radial row 509 are not configured into individual cutting structures with cutting elements of first radial row 507 and are instead maintained as separate bodies. Cutting elements of first radial row 507 are arranged about the outside radius of discs 505 in a compressive configuration. Cutting elements of second radial row 509 are disposed on the face of disc 505 in a shearing configuration. As shown in FIG. 5 , first radial row 507 of cutting elements form a row arranged radially outboard (away from the center of the disc) of the radial position of a row formed by second radial row 509 of cutting elements. [0040] Disc drill bit 501 further includes a webbing 511 disposed on discs 505 . Webbing 511 is arranged on the outside radius of discs 505 and is adjacent to first radial row cutting 507 of cutting elements. Optionally, webbing 511 can be an integral part of discs 505 , as shown in FIG. 5 , wherein webbing 511 is manufactured into discs 505 . However, webbing 511 can also be an overlay that is placed on discs 505 after they have been manufactured. Furthermore, discs 505 could be manufactured, webbing 511 then placed on discs 505 adjacent to first radial row 507 of cutting elements, and webbing 511 then brazed onto discs 505 if necessary. [0041] When drilling earth formations, webbing 511 can provide structural support for first radial row 507 of cutting elements to help prevent overloading. The compressive forces distributed on the cutting elements of first radial row 507 could be translated to webbing 511 for support. The height of webbing 511 can be adjusted such that the depth of cut of the cutting elements of first radial row 507 is limited. Having a low webbing height would allow the cutting elements of first radial row 507 to take a deeper cut when drilling into the earth formation, as compared to the depth of cut a high webbing height would allow. The adjustable webbing height further prevents overloading of the first radial row 509 of cutting elements. [0042] Furthermore, FIG. 5 shows PDC cutting elements 551 located on the bottom of bit body 503 of disc drill bit 501 . Referring now to FIG. 6 , an enlarged view of the arrangement of PDC cutting elements 551 is shown. As discs 505 of disc drill bit 501 cut out a borehole in the earth formation, a bottom uncut portion may form at the bottom of the borehole that is not covered by the cutting surface of discs 505 . Bottom uncut portion 171 is shown in FIG. 1 . As disc drill bit 501 drills into the earth formation, PDC cutting elements 551 may be used to cut out the bottom of the borehole. FIG. 6 also shows a nozzle 553 , which is located on the bottom of bit body 503 . Nozzle 553 provides circulation of drilling fluid under pressure to disc drill bit 501 to flush out drilled earth and cuttings in the borehole and cool the discs during drilling. [0043] Embodiments of the present invention do not have to include the features of the webbing arranged on the discs and the single cutting structure formed from the first and second radial row cutting elements. Embodiments are shown with the webbing alone, and embodiments are shown with the single cutting structure alone. However, other embodiments can be created to incorporate both the webbing and the single cutting structure or exclude both the webbing and the single cutting structure. Those having ordinary skill in the art will appreciate that the present invention is not limited to embodiments which incorporate the webbing and the single cutting structure. [0044] Further, those having ordinary skill in the art will appreciate that the present invention is not limited to embodiments which incorporate only two rows of cutting elements. Other embodiments may be designed which have more than two rows of cutting elements. Referring now to FIG. 9A , another disc drill bit 901 in accordance with an embodiment of the present invention is shown. Disc drill bit 901 includes a bit body 903 having one or more journals (not shown), on which one or more discs 905 are rotatably mounted. Disposed on at least one of discs 905 of disc drill bit 901 are first radial row 907 of cutting elements, second radial row 909 of cutting elements, and third radial row 911 of cutting elements. Cutting elements of first radial row 907 are located closest to the axis of rotation of disc drill bit 901 , followed by the cutting elements of second radial row 909 , and then the cutting elements of third radial row 911 . The cutting elements of first radial row 907 , second radial row 909 , and third radial row 911 act together to drill a borehole with a radius at which the cutting elements of third radial row 911 extend from the axis of rotation of the disc drill bit. Cutting elements of first radial row 907 penetrate into the earth formation to form the bottom of the borehole, the cutting elements of second radial row 909 shear the earth formation to form the sides of the borehole, and the cutting elements of third radial row 911 ream and polish the earth formation to form the full diameter of the borehole. Cutting elements of third radial row 911 enlarge the borehole to a radius at which the third radial row 911 of cutting elements extend from the axis of rotation of disc drill bit 901 . [0045] Referring still to FIG. 9A , first radial row 907 of cutting elements are arranged about the outside radius of discs 905 such that its cutting elements are in a compressive configuration. Second radial row 909 of cutting elements are disposed on the face of discs 905 such that its cutting elements are in a shearing configuration. The third radial row 911 of cutting elements are also disposed on the face of discs 905 of disc drill bit 901 , but second radial row 909 of cutting elements are radially outboard (away from the center of the disc) of the radial position of third radial row 911 of cutting elements. [0046] In some embodiments, the cutting elements of the first radial row are oriented in the compressive configuration and may be comprise tungsten carbide, PDC, or other superhard materials, and may be diamond coated. The cutting elements of the first radial row cutting elements are designed to compress and penetrate the earth formation, and may be of conical or chisel shape. Preferably, the cutting elements of the second radial row have PDC as the cutting faces, which contact the earth formation to cut out the borehole. The cutting elements of the second radial row are oriented to shear across the earth formation. Similarly, the cutting elements of the third radial row have cutting faces which are comprised of PDC. The cutting elements of the third radial row shear across the earth formation to enlarge the borehole to full diameter. [0047] In one or more embodiments of the present invention, to assist in the shearing action, the cutting elements of the second and third radial rows may be oriented with a negative or positive rake angle. Referring now to FIG. 4 , an example of negative rake angle is shown in a prior art PDC cutter 401 . PDC cutter 401 has a PDC cutter disc 403 rearwardly tilted in relation to the earth formation being drilled. A specific angle “A” refers to the negative rake angle the PDC cutter is oriented. Preferably, a rake angle from about 5 to 30 degrees of rake angle orientation is used. Similarly, a positive rake angle would refer to the PDC cutter disc forwardly tilted in relation to the earth formation being drilled. An effective rake angle would prevent delamination of the PDC cutting element. FIGS. 9B and 9C show an embodiment incorporating the use of one rake angle orientation, and FIGS. 10A and 10B show another embodiment incorporating the use of two rake angle orientations. [0048] In FIG. 9B , the cutting elements of second radial row 909 and third radial row 911 are oriented with a positive rake angle to allow the sides of the cutting elements to perform the cutting action. As shown in FIG. 9C , when the cutting elements are moving in the direction 951 , the sides (cylindrical edge) of the cutting elements shear across the borehole to generate failures in the earth formation. Therefore, the sides of the cutting elements are loaded with the predominant cutting forces. The shearing sides of the cutting elements are shown in zones 991 and 993 . [0049] In FIG. 10A , the cutting elements of third radial row 1011 are oriented with a positive rake angle to allow the sides of the cutting elements to perform the shearing cutting action. However, the cutting elements of second radial row 1009 are oriented in a negative rake angle to instead the faces of the cutting elements to perform the shearing cutting action. Thus, with a negative rake angle, the faces of the cutting elements are loaded with the predominant cutting forces. Referring now to FIG. 10B , another view of the embodiment in FIG. 10A is shown. When the cutting elements are moving in the direction 1051 to maximize shearing, the cutting elements in zone 1093 are oriented in a positive rake angle to allow the sides of the cutting elements to shear across the borehole to generate failures in the earth formation, while the cutting elements in zone 1091 are oriented in a negative rake angle to allow the faces of the cutting elements to shear across the borehole. Both rake angle orientations can be used for the cutting elements of embodiments of the present invention. The rake angle orientation may be varied from disc to disc of the disc drill bit, or from radial row to radial row, or even from cutting element to cutting element. The rake angle orientation is not intended to be a limitation of the present invention. [0050] Those having ordinary skill in the art will appreciate that other embodiments of the present invention may be designed with arrangements other than three discs rotatably mounted on the bit body. Other embodiments may be designed to incorporate only two discs, or even one disc. Also, embodiments may be designed to incorporate more than three discs. The number of discs on the disc drill bit is not intended to be a limitation of the present invention. [0051] As seen in roller cone drill bits, two cone drill bits can provide a higher ROP than three cone drill bits for medium to hard earth formation drilling. This concept can also be applied to disc drill bits. Compared with three disc drill bits, two disc drill bits can provide a higher indent force. The “indent force” is the force distributed through each cutting element upon the earth formation. Because two disc drill bits can have a fewer amount of total cutting elements disposed on the discs than three disc drill bits, with the same WOB, two disc drill bits can then provide a higher indent force. With a higher indent force, two disc drill bits can then provide a higher ROP. Two disc drill bits can also allow larger cutting elements to be used on the discs, and provide more flexibility in the placement of the nozzles. Further, the discs on two disc drill bits can be offset a larger distance than the discs of three disc drill bits. In the event a two disc drill bit is designed, an angle from about 165 to 180 degrees is preferred to separate the discs on the disc drill bit. [0052] Additionally, those having ordinary skill in the art that other embodiments of the present invention may be designed which incorporates discs of different sizes to be disposed on the disc drill bit. Embodiments may be designed to incorporate discs to be rotatably mounted to the disc drill bit, in which the discs vary in size or thickness in relation to each other. The size of the discs is not intended to be a limitation of the present invention. [0053] Referring now to FIG. 7 , a cutting structure 701 in accordance with another embodiment of the present invention is shown. Cutting structure 701 includes a compressive portion 705 and a shearing portion 703 formed into a single body. Shearing portion 703 of cutting structure 701 is comprised of PDC. Cutting structure 701 may be placed on a disc of a disc drill bit by being brazed onto the disc, or cutting structure 701 may be integrally formed into the discs when manufactured. Cutting structure 701 is then disposed on the disc such that shearing portion 703 is arranged in a shearing configuration to generate failures by shearing the earth formation when drilling and compressive portion 705 is arranged in a compressive configuration to generate failures by crushing the earth formation when drilling. [0054] In the embodiments shown, compressive portion 705 of cutting structure 701 may be comprised of tungsten carbide, PDC, or other superhard materials, and may be diamond coated. Compressive portion 705 , which may be of a conical or chisel shape, is designed to compress and penetrate the earth formation. Shearing portion 703 of cutting structure 701 has PDC as the cutting face which contacts the earth formation to cut out the borehole. Shearing portion 703 is designed to shear across the earth formation. [0055] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

The invention provides an improved drill bit and a method for designing thereof. The drill bit includes a bit body, a journal depending from the bit body, and a disc rotatably mounted on the journal. The disc of the drill bit has PDC cutting elements disposed on it. Also provided is an improved cutting structure for the discs of the drill bit. The cutting structure includes a portion that is comprised from PDC.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of co-pending provisional application No. 61/056,000 filed May 25, 2008. FIELD OF INVENTION [0002] This invention relates to pattern analysis. This invention relates particularly to methods and devices for detecting and analyzing energy fields emitted by organisms. BACKGROUND [0003] All live organisms emit energy fields, referred to herein as vital fields, which are characterized by the organic processes that produce or modify them. There is a significant amount of skepticism surrounding vital fields because no known scientific instruments can detect them. The inability to detect, measure, and describe the energy in a vital field is a problem that inhibits human understanding of biological interactions with the environment. [0004] A wave in an energy field is considered to comprise four components—electric, magnetic, gravitational and temporal. The electric, magnetic, and gravitational components are orthogonal to each other. In an electromagnetic wave, the gravitational and temporal components have a static value, and the electric and magnetic components vary inversely. In this context, a static temporal component equates to time moving forward at a constant rate. In contrast, a vital wave is theorized to contain static electric and magnetic components and dynamic temporal and gravitational components. Such a wave is essentially a longitudinal or compression wave in the space-time fabric. Because vital waves do not have a dynamic magnetic component, they do not induce a current in a conductor. Most known devices rely on such induction and is therefore unable to reliably detect the presence of vital waves or measure or describe them scientifically. [0005] Kirlian photography, discovered in the early 20th century, can be considered one of the earliest means of analyzing vital fields. Kirlian photography works by driving a photographic plate at high voltage, with a biological specimen resting on the plate. The resulting image left on the film is consistent with the corona discharge pattern of the specimen. Live specimens tend to show a shimmering coronal effect, whereas dead specimens and inanimate objects exhibit a more uniform pattern. The difference is attributed to the live specimen having at least one vital field. It should be noted, however, that Kirlian photography as an indication of vital fields has been met with skepticism, with the results explained away as errors in the experimental process. [0006] Most vital field detection devices to date have been either a variation of Kirlian high-voltage equipment or low voltage electric field sensors. One device, used to detect pathogens in an organism, places the organism in an electrical field and detects an aura signature of pathogens energized by the field. Another device uses a passive detector that characterizes pulses of charge transfer called charge density pulses through conductive plates placed near the palms of the hands. The decay envelope of the detected pulse train may provide information useful for analysis of the body's chakra regions. However, the data is extracted from a pulse train that does not achieve a steady state, and so the data that can be obtained is limited. Further, the data describing the electric component of present waves would not completely describe the temporogravitational wave because its electric component is static. [0007] Some detectors, such as electrocardiographs and electroencephalographs, analyze alternating current waveforms detected by electrodes placed on the skin of the test subject. One known device uses contacts on the palms and fingers to detect the physiological signals of the human body supposedly associated with auras. Other detectors introduce an electric current into the electrodes, such as with a galvanic skin response and others, which measure the organism's interaction with the introduced current through physical contact between the organism and the detector. Still other devices use capacitance to measure the interaction, but must be placed extremely close to the organism to be effective. Contact and capacitance based devices suffer significant problems with artifacts caused by the proximity. [0008] One device capable of detecting the static magnetic component of a wave is the Superconducting Quantum Interference device, or “SQUID.” SQUIDS are highly sensitive, extremely expensive magnetometers. However, SQUIDS only detect the presence of strong waves. A typical vital field generated by an organism has weak vital waves that SQUIDS cannot detect. Further, SQUIDS do not detect the spectral information needed analyze a vital field. [0009] A detection device that is inexpensive, reliable, and capable of detecting vital fields is needed. Therefore, it is an object of the present invention to reliably detect and analyze vital fields. It is a further object that the vital fields be detected with a device that is relatively inexpensive compared to known devices. It is another object of the invention that the device and method of detection reduces unwanted artifacts by not contacting the organism. SUMMARY OF THE INVENTION [0010] The present device is placed in a vital field such that the vital waves in the vital field are conducted into a detector having an avalanche diode and an avalanche initiator. The avalanche diode is preferably an avalanche photodiode (“APD”). The APD is reverse biased and the bias voltage is supplied by a voltage source. The avalanche initiator impacts the avalanche diode with sufficient energy to generate seed electrons for the electron avalanche process. The energy provided by the avalanche initiator to the avalanche diode may be continuous or pulsed. The avalanche initiator is preferably an optical energy source, and most preferably a silicon vertical cavity surface emitting laser (“VCSEL”), but may be a high-electronvolt generator if the avalanche diode is not a photodiode. Preferably, the vital waves are conducted into the active region of the APD through a focusing horn to concentrate the energy. [0011] Control circuitry provides a first control signal at a first sampling frequency to the detector. The first control signal is chosen to undersample the vital waves from the vital field, which have very high frequency. The first control signal modulates the gain of the avalanche diode. The avalanche initiator provides sufficient energy to the avalanche diode to create free electrons that start the avalanche process. During the period of increased gain, the vital waves from the vital field cause a detectable interference with the electric field in the active region of the avalanche diode, producing a first mixed signal including a first beat frequency that is the difference between the frequency of the vital waves and a high harmonic of the first sampling frequency. [0012] The first mixed signal is conducted to signal processing circuitry, which filters the signal and applies Fourier transforms. Extraction of the beat frequency from the first mixed signal indicates that the vital waves are present. Then, the control circuitry is adjusted to produce a second control signal and the detection process repeats, producing a second mixed signal with a second beat frequency. The signal processing circuitry uses the first and second beat frequencies to determine the frequency of the vital waves from the vital field. The results of the signal processing are then displayed on a screen. Both the control circuitry and the signal processing circuitry include components that work to limit noise and other artifacts generated during the detection process. [0013] Through continued use of the device, a reference database is developed to associate vital fields with the organisms, organs, organic material, metaphysical changes, or conditions presumed to generate the vital fields. BRIEF DESCRIPTION OF THE DRAWINGS [0014] FIG. 1 is a schematic diagram of the present device. [0015] FIG. 2 is a circuit diagram of the preferred embodiment of the present device. [0016] FIG. 3 is a circuit diagram of an alternate embodiment of the present device. DETAILED DESCRIPTION OF THE INVENTION [0017] FIG. 1 illustrates the present invention, which is a device 10 for detecting and analyzing vital fields. The device 10 is placed in the path of vital waves 19 that are present in the vital field to be detected. The detection process is initiated through a user interface 14 , such as by pressing a button or a designated part of a touch screen that indicates to control circuitry 11 that the process should begin. The control circuitry 11 then generates, as described in detail below, a first control signal having a first sampling frequency, and sends the first control signal to a detector 12 . The control circuitry 11 may also send the first control signal to signal processing circuitry 13 for use in a frequency converter as described below. [0018] To achieve the desirably high sensitivity of the device 10 , the detector 12 may be substantially enclosed by electromagnetic shielding 15 . The shielding 15 protects the internal components of the detector 12 from unwanted interference by light and other electromagnetic waves. The shielding 15 may be a Faraday cage or other shielding structure. If light-sensitive components are not used, the shielding 15 may be a mesh of conducting material, but preferably the shielding 15 fully encloses the detector's 12 internal components, except that a small opening may be left in the shielding to allow the vital waves 19 to pass into the detector 12 . In the preferred embodiment, this opening is covered by an opaque dielectric material (not shown) that blocks light but allows the vital waves 19 to pass. The dielectric material may be any electrical insulator, including insulating tape such as vinyl, plastic, or polyester tape. Preferably, the dielectric material is black polyester tape. [0019] The internal components of the detector 12 include an avalanche diode 16 and an avalanche initiator 17 that cooperate to control the parameters of an electron avalanche. The electron avalanche amplifies the signal passing through the avalanche diode 16 by a multiplication factor, known as the gain, which is inversely proportional to the difference between the avalanche diode's 16 breakdown voltage and the voltage applied to the avalanche diode 16 . The vital waves 19 entering the device are detectable at a high gain. The device 10 is therefore configured to drive the gain as high as possible. The gain is limited by the intrinsic resistance of the avalanche diode 16 but preferably the peak gain is at least 20,000 and most preferably about 50,000. The avalanche diode 16 may be any avalanche diode that can achieve this gain range and that has device geometry that allows the vital waves 19 to propagate substantially parallel to the electron avalanche, including a standard avalanche diode, a modified Zener diode, or an APD. The diode may use any suitable semiconducting material, including silicon, germanium, and InGaAs, and may be doped to increase the gain range. The diode may alternatively propagate the signal through an air avalanche, but a semiconducting material is preferable because it will have a much lower impedance than air. Preferably, the avalanche diode 16 is a doped silicon APD. The avalanche diode 16 is reverse biased and a constant voltage is applied to the cathode of the avalanche diode 16 to keep the avalanche diode 16 biased in its linear region. Then, the avalanche diode 16 is modulated to its peak gain as described below. [0020] The avalanche initiator 17 emits energy that impacts the semiconducting material of the avalanche diode 16 , causing impact ionization and creating seed electrons for the electron avalanche. The appropriate avalanche initiator 17 will depend on the type of avalanche diode 16 used. In the preferred embodiment, the avalanche initiator 17 is an optoelectronic device with low residual intensity noise and sufficient energy to cause impact ionization in the preferred APD. Suitable devices include lasers such as a VCSEL or fiber laser, and light-emitting diodes such as a resonant cavity light-emitting diode (“RCLED”). The avalanche initiator 17 is most preferably a silicon VCSEL. Alternatively, the electron avalanche may be initiated by voltage alone, such as in a standard avalanche diode, and the avalanche initiator 17 may be a generator functioning as a device electrode and capable of applying enough electronvolts to the avalanche diode 16 to prompt impact ionization. Such an avalanche diode 16 may be doped to allow electron avalanche initiation by voltage alone. [0021] The first control signal is directed to the avalanche diode 16 , where it causes the application of a low voltage to the cathode as described below. This low voltage brings the total voltage at the cathode up to within, preferably, several millivolts of the breakdown voltage of the avalanche diode 16 . The applied voltage significantly raises the operating gain of the avalanche diode 16 as it approaches the breakdown voltage of the avalanche diode 16 . The period of high operating gain is referred to as the high gain period. The low voltage is preferably modulated such that it varies from 0 to between 5 and 10 volts on a sine wave having the first sampling frequency. In the preferred embodiment, the high gain period lasts for between 20 and 50 picoseconds, during which the operating gain is increased from a factor of around 70 to a peak factor of more than 25,000. In the alternate embodiment described below, where a logic level pulse of low voltage is applied to the avalanche diode 16 , the high gain period lasts for as much as 10 nanoseconds, and typically between five and 10 nanoseconds. [0022] In the preferred embodiment, described in detail below and in FIG. 2 , the avalanche initiator 17 constantly emits energy, most of which impacts the avalanche diode 16 . The amount of energy provided to the avalanche diode 16 is adjustable in order to generate approximately a desired number of seed electrons for the electron avalanche. Preferably, a low average number of seed electrons are generated, and most preferably the impact ionization produces an average of five seed electrons during the high-gain period of the avalanche diode 16 . [0023] In an alternate embodiment, described in detail below and in FIG. 3 , the first control signal is synchronized to provide a current pulse to the avalanche initiator 17 during the high-gain period of the avalanche diode 16 . The current pulse causes the avalanche initiator 17 to pulse at the first sampling frequency. Each pulse of the avalanche initiator 17 causes an electron avalanche to propagate through the active region of the avalanche diode 16 . [0024] In either described embodiment, the avalanche propagates so quickly, typically within about 100 picoseconds, that the first sampling frequency is retained in the resulting amplified signal that is emitted from the anode of the avalanche diode 16 . The resulting signal is called the first mixed signal, as described below. [0025] The vital waves 19 pass into the detector 12 and are incident on the avalanche diode 16 . Preferably, a focusing horn 18 is used to concentrate the vital waves 19 into the active region of the avalanche diode 16 where the electron avalanche process takes place. The focusing horn 18 is made of a conductive material, preferably metal, that will reflect the vital waves 19 due to their static electric component. Suitable metals include brass, copper, and aluminum, but most preferably the focusing horn 18 is brass. The focusing horn 18 is soldered to the shielding 15 to prevent light leaks, and the dielectric material is used to cover the end of the focusing horn 18 inside the detector 12 . [0026] An electron avalanche requires the presence of a strong electric field in the active region of the avalanche diode 16 . This field is static, assuming no interference and a constant applied voltage, and it has a known strength that is dependent on the intrinsic breakdown voltage of the avalanche diode 16 used. However, the incident vital waves 19 also have a static electric component, which interferes with the electric field in the active region and may advance or retard the avalanche process. In the case where the vital waves 19 have extremely high frequencies, of at least 30 gigahertz and further into the terahertz range, undersampling may be used to determine the frequency. The signal propagated through the avalanche diode 16 has sufficient harmonic content that heterodyning occurs between the vital waves 19 and a high harmonic of the first sampling frequency. As a result, the first mixed signal, carried out of the avalanche diode 16 by the amplified current, contains a first beat frequency that is the difference between the frequency of the vital waves 19 and a high harmonic of the first sampling frequency. [0027] The first mixed signal is then processed by signal processing circuitry 13 . As described below, the first mixed signal undergoes filtration, optional frequency conversion, and Fourier transformation to extract the desired frequency data. During or after this processing, the control circuitry generates a second control signal having a second sampling frequency and sends it to the detector 12 , resulting in a second mixed signal having a second beat frequency. The second mixed signal is also processed by signal processing circuitry 13 . The second beat frequency is subtracted from the first beat frequency to obtain the beat frequency shift. [0028] The harmonic with which the vital waves 19 were heterodyned is determined by dividing the sampling frequency shift by the beat frequency shift. The harmonic number of the first sampling frequency then allows calculation of the observed frequency imparted by the vital waves 19 . The detection process may be repeated with additional sampling frequencies to reduce uncertainties if multiple vital wave 19 frequencies are present. [0029] The spectral data of the detection process may be formatted and displayed on a screen in the user interface 14 . Further, the spectral data may be compared to records in a reference database to determine if it matches information gathered on known vital fields. In this manner, if it has been determined that certain data previously gathered by the device 10 correlates to, for example, the presence of a blood disease or its precursors, the results of the detection process may be compared to the previously collected data to determine if the scanned person has the same disease or its precursors. Reference databases may be generated for specific plants and animals, and may be used to detect vital fields associated with bodily states and conditions, the presence or absence of diseases, and aspects of other body energies such as chakra or qi. [0030] Referring to FIG. 2 , the preferred embodiment of the device 10 utilizes a silicon APD 21 . These devices are capable of a very high operating gain, which corresponds to desirably high sensitivity in detecting the weak vital waves in a vital field. However, APDs are also susceptible to significant noise due to their sensitivity. Therefore, the preferred embodiment of the present device endeavors to minimize noise in the circuit using components that filter unwanted signals and maintain low impedance on sensitive elements. [0031] When the detection process is initiated, a master clock oscillator 28 supplies the master clock frequency to a signal source 55 , which produces the first control signal at the first sampling frequency. The master clock oscillator 28 is preferably a voltage controlled crystal oscillator, allowing the frequency to be controlled by a digital-to-analog converter 29 . Alternatively, the master clock oscillator 28 may be a frequency synthesizer. The signal source 55 is a frequency synthesizer. The signal source 55 sends the first control signal into the detector 12 . [0032] Within the detector 12 , a pulse buffer 25 provides a low impedance drive for the APD 21 bias modulation. The pulse buffer 25 is a transistor amplifier, either discrete or part of an integrated circuit, and is preferably a GaAs monolithic microwave integrated circuit (“MMIC”). Alternatively, a MMIC using a different semiconducting material, or a CMOS inverter, may be used. A pulse inductor 53 performs impedance matching to maximize power transfer to the APD 21 . The pulse capacitor 22 and high-stop capacitor 23 present low impedance on the cathode of the APD 21 . The pulse capacitor 22 also couples a periodic low voltage onto the APD 21 bias. In a typical embodiment, the low voltage modulates in a sine wave having the first sampling frequency and a maximum amplitude of between five and 10 volts, which will sum with a constant high voltage bias to raise the applied voltage to just below the breakdown voltage of the APD 21 . During this modulation, the avalanche gain will peak at over 25,000 for about 35 picoseconds. The voltage source 35 supplies the high voltage bias to the APD 21 . The voltage level is controlled by an external computer processor. The voltage is adjusted to give a fixed current through the bias resistor 36 . The bias resistor 36 also forms a low pass noise filter with the pulse capacitor 22 . The pulse capacitor 22 coupling, low pass filtration, and low impedance together reduce noise contributed by the APD 21 dark current or light leakage in the vicinity of the APD 21 . Modulation of the APD 21 gain also eliminates any potential problems with sensitivity reduction due to the APD 21 gain-bandwidth product, because ejected electrons are more quickly replenished in the active region during periods of low gain. Noise from the dark current, caused by impurities in the APD 21 , is further reduced by keeping the active region of the APD 21 very small. [0033] The VCSEL 30 has low noise but may be susceptible to temperature or manufacture variation that affects the consistency of emitted light. Therefore, an automatic level control circuit (“ALC”) 51 provides an adjustable current to the VCSEL 30 . The current from the ALC 51 causes the VCSEL 30 to emit a substantially constant amount of light, most of which impacts the APD 21 . Some of the light hits a monitor diode 52 , preferably a PIN diode, that detects the amount of light being emitted and signals the ALC 51 to adjust the current if the amount is outside the range needed to generate the desired average number of seed electrons by impact ionization of the semiconducting material in the APD 21 . In an alternate embodiment using an RCLED as the avalanche initiator 17 , an ALC 51 and monitor diode 52 may not be needed due to the RCLED being much less sensitive to temperature than a VCSEL. [0034] The fewer the number of seed electrons, the higher the possible avalanche gain and hence, the sensitivity. However, with a sufficiently small number of seed electrons, the quantized nature of electron charge introduces quantization noise which limits the sensitivity. Preferably, at least five seed electrons are generated by an optical pulse, and most preferably exactly five. The signal is multiplied exponentially due to the nature of the electron avalanche process, and this effect is magnified by modulating the high-gain period of the APD 21 . Modulation at the first sample frequency creates harmonics that are beyond the harmonic content of the first control signal. [0035] Because the APD 21 is biased in the linear region, the avalanche gain is limited by the intrinsic impedance of the APD 21 , including any parasitic reactance associated with the APD 21 . The APD 21 must see a short circuit at high frequencies, particularly between 2 and 3 gigahertz, to minimize this intrinsic impedance and also to eliminate frequencies that are contributed to the mixed signal by the APD 21 geometry. The short circuit is provided by a short-circuit lowpass filter 33 , which has a cutoff frequency of half the first sampling frequency. The short-circuit lowpass filter 33 therefore suppresses the first sampling frequency, preventing overload of the signal processing circuitry. In the preferred embodiment, the short-circuit lowpass filter 33 is a lumped element filter. The baseband DC amplifier 34 and baseband AC amplifier 54 both present a suitable terminating impedance for the short-circuit lowpass filter 33 and set the baseband noise floor after the APD 21 . The baseband DC amplifier 34 is DC coupled and is used if the first mixed signal has a low enough frequency to be passed through an analog-to-digital converter (“ADC”) 47 . The baseband AC amplifier 54 is AC coupled and filters out the DC portion of the first mixed signal if a frequency conversion is needed. [0036] The first mixed signal, now a baseband signal, may be routed through a frequency converter 50 . This is not a necessary step, but it can provide a more practical realization by allowing a sampling frequency that is much higher than the ADC 47 sampling rate. Because most signals of interest are undersampled, doubling the sampling frequency will produce about a 3 decibel improvement in signal to noise ratio. Within the frequency converter 50 , the first intermediate frequency mixer 40 provides frequency conversion to a first intermediate frequency (“IF”) by mixing the first mixed signal with a signal generated by the first local oscillator 43 . The first local oscillator 43 is preferably a frequency synthesizer that is in phase lock with the master clock oscillator 28 . Preferably, the IF is 916.36 megahertz to allow the use of an inexpensive inline surface acoustic wave (“SAW”) filter for the first IF filter 41 . The first IF filter 41 then provides image rejection in the down-converted signal to improve the performance of a second IF mixer 56 . The second IF mixer 56 converts the first mixed signal to a frequency of 10.7 megahertz to allow the use of a ceramic filter as a second IF filter 57 , which provides high quality noise filtering of the signal. The sampling mixer 42 mixes the IF with a signal from a second local oscillator 44 to convert the first mixed signal down to a suitable range for the ADC 47 sampling rate. The second local oscillator 44 is preferably a frequency divider that takes the master clock signal as an input. The switch 38 is used to bypass the frequency converter 50 . Anti-alias lowpass filter 39 provides anti-aliasing filtering of the baseband first mixed signal when the frequency converter 50 is bypassed. [0037] With a master clock of 44 megahertz, the second local oscillator 44 signal is 11 megahertz, the first sample frequency is 905.66 megahertz, and the baseband first mixed signal ranges from 0 to 452.83 megahertz. These frequencies are chosen to allow the use of low cost ceramic and SAW filters. Additionally, a sampling frequency at or near 1 gigahertz allows the use of smaller Fourier transforms during signal processing. The smaller transforms account for both random variation in detected frequencies and frequency drift in the signal source 55 . The frequency converter 50 loss is corrected by a converter amplifier 45 . Any out of band noise from the converter amplifier 45 is removed by a converter lowpass filter 46 . [0038] The baseband signal is digitized by ADC 47 . A Fourier transform computer 48 computes a large fast Fourier transform (“FFT”) to detect the desired signals, such as the first beat frequency, within the baseband signal. After the detection process is run a second time to acquire a second beat frequency, the computer 48 calculates the input frequency. The FFT results are processed and displayed on the screen 49 . [0039] Referring to FIG. 3 , an alternate embodiment of the device 10 utilizes a silicon APD 21 and a silicon VCSEL 30 . When the detection process is initiated, the master clock oscillator 28 supplies the master clock frequency to a clock frequency divider 27 , which produces the first sampling frequency. The clock frequency divider 27 supplies the first sampling frequency to an asynchronous state machine (“ASM”) 26 that generates a narrow pulse on one edge of the incoming waveform. The ASM 26 is preferably a gate and inverter, generating a first control signal having the first sampling frequency and a pulse length of several nanoseconds. The first control signal is sent into the detector 12 . [0040] Within the detector 12 , the pulse buffer 25 provides a low impedance drive for the APD 21 bias pulsing. A pulse resistor 24 forms a low pass filter with high-stop capacitor 23 to limit the rate of APD 21 bias change. The pulse capacitor 22 and high-stop capacitor 23 present low impedance on the cathode of the APD 21 . The pulse capacitor 22 also couples a periodic low voltage onto the APD 21 bias. In a typical embodiment, the logic level pulse has a maximum voltage of about 2V, which will raise the biased voltage to just below the breakdown voltage of the APD 21 and raise the avalanche gain from 70 to about 20,000 for several nanoseconds. The voltage source 35 supplies the high voltage bias to the APD 21 . The voltage level is controlled by an external computer processor. The voltage is adjusted to give a fixed current through the bias resistor 36 . The bias resistor 36 also forms a low pass noise filter with the pulse capacitor 22 . [0041] The time delay circuit 32 produces a time delay to align an optical pulse with the APD 21 high gain period. The time delay circuit 32 is a logic device or a resistor-capacitor circuit chosen to cause the desired delay while retaining the incoming signal frequency. A pulse generator 31 , preferably a regenerative switch, provides a current pulse to the VCSEL 30 on the rising edge of the first control signal. Alternatively, the pulse generator 31 may be a step recovery diode. The pulse generator 31 produces a pulse that is sufficient to cause the VCSEL 30 to emit a very short pulse of light. The duration of the light pulse is made as short as possible while emitting sufficient energy to generate approximately the preferred number of seed electrons in the APD 21 , as described below. For a VCSEL with 3 gigahertz bandwidth, the pulse is preferably in the range of 50-100 picoseconds. The pulse may be even shorter if a fiber laser is used. [0042] The short circuit of high APD 21 frequencies is provided by short-circuit lowpass filter 33 , which has a cutoff frequency of half the first sampling frequency. In the present embodiment, short-circuit lowpass filter 33 is a lumped element filter. The baseband amplifier 34 presents a suitable terminating impedance for the short-circuit lowpass filter 33 , and sets the baseband noise floor after the APD 21 . [0043] The first mixed signal, now a baseband signal, may be routed through a frequency converter 50 . Within the frequency converter 50 , intermediate frequency mixer 40 provides frequency conversion to the IF by mixing the first mixed signal with a signal generated by the first local oscillator 43 . In the present embodiment, the first local oscillator 43 is a direct digital frequency synthesizer that tunes from 11.0 to 17.8 megahertz. Preferably, the IF is 10.7 megahertz to allow the use of inexpensive ceramic filters for the first IF filter 41 . In the present embodiment, the first IF filter 41 is a ceramic filter that provides high quality noise filtering of the down-converted signal. The sampling mixer 42 mixes the IF with a signal from a second local oscillator 44 to convert the first mixed signal down to a suitable range for the ADC 47 sampling rate. The second local oscillator 44 is preferably a frequency divider that takes the master clock signal as an input. Switches 37 and 38 are used to bypass the frequency converter 50 at low frequencies if desired. Anti-alias lowpass filter 39 provides anti-aliasing filtering of the baseband first mixed signal when the frequency converter 50 is bypassed. [0044] With a master clock of 44 megahertz, the second local oscillator 44 signal is 11 megahertz, the first sample frequency is 14.66 megahertz, and the baseband first mixed signal ranges from 0 to 7.33 megahertz. These frequencies are chosen to allow the use of low cost ceramic filters, and the use of low cost CMOS analog switches for frequency mixing. The frequency converter 50 loss is corrected by a converter amplifier 45 . Any out of band noise from the converter amplifier 45 is removed by a converter lowpass filter 46 . [0045] The baseband signal is digitized by ADC 47 . A Fourier transform computer 48 computes a large fast Fourier transform (“FFT”) to detect the desired signals, such as the first beat frequency, within the baseband signal. After the detection process is run a second time to acquire a second beat frequency, the computer 48 calculates the input frequency. The FFT results are processed and displayed on the screen 49 . [0046] While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

A device and method of detecting and analyzing a vital field places an avalanche diode in the path of vital waves in the vital field. The vital waves interfere with the electron avalanche process in the avalanche diode. Control circuitry and an avalanche initiator cause electron avalanches at a known sampling frequency. The interference from the vital waves produces a beat frequency that is output from the avalanche diode. By adjusting the sampling rate by a known amount, a second beat frequency is produced and the beat frequency shift is used to determine the input frequency of the vital waves. The vital waves are very weak and produce frequencies into the terahertz range, so that the input frequency is undersampled by the device. Further, high sensitivity is required and a circuit design is implemented to maximize sensitivity while minimizing noise and other interference that is common to avalanche diode operation.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is related to U.S. provisional application Serial No. 60/260,412 filed Jan. 9, 2001. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates in general to the field of electronic storage of data and in particular to methods and apparatus for electronically storing agent coupon data associated with airline tickets procured through a travel agent. [0004] 2. Description of the Prior Art [0005] Most, if not all airline ticket service organizations or travel agents provide the service of reserving and issuing airline tickets to travelers. An airline agency known as the Airline Recording Corporation (ARC) requires travel agencies to retain physical copies of “agent coupons” for a minimum of two years from the date of issuance of an airline ticket. In general, an agent coupon contains data associated with an issued airline ticket such as the name and address of the passenger, travel dates, the name of the airline, departure and arrival locations and time, fares charged for the ticket, and other like data. The primary reason for the ARC requirement to have airline ticket agencies retain hard copies of the agent coupons is to have a complete record of the ticket transaction should a dispute arise, for example, regarding a refund, when a ticket exchange is necessary or any other like reason. The agent coupons are not, therefore, generally accessed by the airline ticket agencies on a daily basis but rather only a sporadic or a necessary basis. Still, the ARC requirement inherently necessitates that the airline ticket agencies provide for storage of the hard copies of the coupons. And, in the travel industry, it is common for the agencies to keep the agent coupons for a period of time longer than the required minimum of two years. Such self-imposed requirements mean that the travel agents must provide for long-term storage of the coupons. [0006] Because of the nature of the required and self-imposed storage of the agent coupons in conjunction with the “access as necessary” of the coupons, the physical storage of the coupons pose a number of unique problems. For example, a storage facility or storage space is required. If the storage space is within the offices of the service agency, the agent coupon records not only consume valuable office space that otherwise could be used to generate fees, but the physical presence of the coupons themselves often hinders the office personnel in carrying out their everyday duties. Accordingly, in order to minimize the storage space taken up by the agent coupons, and because of the card-like nature of the coupons, the coupons are usually stored, one behind the other, in boxes that are sized to accommodate the coupons. The boxes themselves are then stacked on top of each other in chronological order with the most recent coupons being located on the upper levels. Then, accordingly, when a particular coupon is to be retrieved, the boxes must be un-stacked to gain access to the box containing the particular coupon. After the coupon is retrieved and processed, the procedure is reversed in order to reorganize the stored coupons. obviously, such a procedure is time consuming, expensive, and inconvenient. [0007] If a separate off-site storage facility is used to store the agent coupons, the rental space will be less costly than office space but then other inconvenient and expensive factors become involved. For example, the retrieval effort is even more time consuming and inconvenient in that office personnel must travel to and from the off-site storage facility. There is still then the problem of having to un-stack the boxes, retrieve the particular coupon, and then re-stack the boxes. It is axiomatic that the larger the travel agency, the more these problems are exacerbated. [0008] What is needed are apparatus and methods that allow for the ease of maintaining the storage of travel agency agent coupons, allow for ease of retrieval, eliminate the need for a separate storage space, provide for secure storage, and are cost effective. The present invention accomplishes these objectives. SUMMARY OF THE INVENTION [0009] The above-stated objects as well as other objects which, although not specifically stated, but are intended to be included within the scope the present invention, are accomplished by the present invention and will become apparent from the hereinafter set forth Detailed Description of the Invention, Drawings, and Claims appended herewith. The present invention accomplishes these objectives by providing methods and apparatus for electronic storage of agent coupons in a most effective manner. [0010] In one embodiment of the present invention, electronic data storage apparatus is electronically connected to an airline ticket reservation arrangement with the latter being located in the office of an airline ticket agency. As an airline ticket is being generated by the reservation system, the agent coupon data is being transmitted simultaneously to the electronic storage apparatus. Alternatively, the coupon data can be transmitted to the electronic storage apparatus in a batch file arrangement. The transmitted data is stored on a known type of storage apparatus such as a hard drive and on a CD ROM disk. The stored data is retrievable from a computer workstation that can access the storage apparatus by a serial connection, a modem connection or an intranet/internet network connection. Once the particular coupon data is accessed, a printer is used to print out the stored data, which includes all of the data normally associated with an agent coupon. The reservation system, the storage apparatus, the retrieval apparatus, and the printer can each be located at the same site, or each can be located at a different site, or each can be located at any combination thereof. Any site can be activated by an intranet network connection or by an internet network connection using an appropriate internet browser. [0011] In accordance with the above, there has been summarized the more important features of the present invention in order that the detailed description of the invention as it appears in the below detailed description of the same, may be better understood. BRIEF DESCRIPTION OF THE DRAWINGS [0012] Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which: [0013] [0013]FIG. 1 is a schematic block flow diagram of one embodiment of the present invention illustrating the apparatus and methods as contemplated by the present invention; [0014] [0014]FIG. 2 is a schematic block flow diagram of the basic apparatus of FIG. 1 as applied to a computer network arrangement. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0015] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functioning details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Additionally, the words and phrases used herein are intended to better enable a person to understand the invention and therefore, such words and phrases are not to be interpreted as limiting the invention. [0016] Reference is now made to the drawings, wherein like the characteristics and features of the present invention shown in the various figures are designated by the same reference numerals. FIG. 1 illustrates one embodiment of the apparatus and method of the present invention. A typical airline ticket reservation system 11 is electronically connected to appropriate electronic data storage apparatus 15 that can but not necessarily comprise a computer having a hard drive and CD-ROM capability. An appropriate software program 14 is loaded into the data storage apparatus 15 that enables the airline ticket reservation system to electronically communicate with the data storage apparatus 15 as more fully explained hereinafter. The reservation system 11 can comprise the electronic apparatus that an agency normally employs to record and generate an airline ticket and the prior art agent coupon. The electronic connection can be a serial connection, a modem connection, or an intranet/internet network connection. Thus, the electronic storage apparatus 15 can be on the site of the reservation system 11 or can be remotely located therefrom. In accordance with the software program 14 , agent coupon data 13 is simultaneously generated along with an airline ticket 12 . The data 13 generated by the reservation system 11 can comprise all of the data entered onto an airline ticket, including but not limited, to the data normally associated with an agent coupon as well as any other data deemed appropriate. The data 13 to be stored can be transmitted for example, in image format, accounting record format, or data file format. The data 13 can be transmitted to the storage apparatus 15 at the time each airline ticket 12 is created. The data and information can be temporarily stored within the reservation system 11 and upon the generation of a plurality of tickets, the temporarily stored data can be transmitted in a batch file format to the storage apparatus 15 . The transmitted data 15 is stored in the storage apparatus 13 under, for example, a file designation that can include the ticket number, the passenger's name, the passenger's record locator or number, and the airline ticket agency's or the travel agent's information. The stored file is then moved to, for example, to a primary directory comprising the Airline Reporting Corporation's number and a sub-directory created by calculating the Sunday following the date of issue of the ticket. Thus, for example, the directory structure can comprise: ARC number (directory)/sales period ending date (directory), ticket number, passenger name, and record locator (image files). [0017] On a continual or on a nightly basis, the data 13 stored in storage apparatus 15 can be transferred to files named, for example, “DATE.tgz”. The “tgz” files can be written to a Random Operating Memory (ROM) compact disk (CD) 16 . It is preferred at this time, to record the sales period ending date and the issue date for which this data belongs, into a reference file for future lookup and or retrieval purposes. The software program 14 incorporated in the storage apparatus 15 continuously checks and verifies the available space on the CD 16 , and when the CD 16 is full, a message is sent advising an operator to change to a new CD 16 . Each CD 16 can have a header file identifier for identification purposes. Alternatively, the data can be simultaneously stored on both a hard disk and a CD 16 . [0018] When a dispute, refund, or exchange occurs, the coupon data 13 stored in the storage apparatus 15 and the CD-ROM disk 16 can be retrieved as follows. The operator activates a retrieval portion of the software program 14 that is loaded into the storage apparatus 15 and inputs information which allows for the retrieval of a particular coupon data, including but not limited to, for example, the agency code number (ARC number), sales period ending date, the ticket number, the record locator and the passenger's name. The storage apparatus 15 searches its hard drive for the file. If the file is not available, because of a system crash or because the file has been purged from the computer, an operator is directed to load the appropriate CD 16 containing the desired data. Upon retrieval of the desired data, a display screen 17 associated with the storage apparatus 15 displays an image consistent with the image of a physical coupon or simply displays the data 13 in any other appropriate format. It is then a simple matter for the operator to command the storage apparatus 15 to print an image of the coupon being retrieved. In this regard, an appropriate printer 18 , is electronically connected to the storage apparatus 15 . The printed image 19 can be on plain paper in the coupon format, or can be printed on actual ARC approved ticket coupon stock, or can be printed in any appropriate data format. [0019] [0019]FIG. 2 illustrates the apparatus and methods of FIG. 1 as applied to a networked retrieval arrangement. In FIG. 2, a central storage computer 21 is used as the storage apparatus. As in the previous embodiment of FIG. 1, the central storage computer 21 is arranged to receive ticket information from a reservation system (CRS) 11 through an electronic data connection. A plurality of computer equipped workstations 22 are network connected to the central storage computer 21 . A central coupon data printer 23 is connected to the central storage computer 21 . One or more additional coupon printers 24 can be connected to the networked stations 22 in an appropriate manner consistent with the physical location and arrangement of the workstations 22 . [0020] The inventive methods include the storage and retrieval of an electronic agent coupon as follows. The reservation system 11 of a travel agent is electronically connected to an appropriate electronic storage and retrieval system 15 that is provided with appropriate software 14 . Upon generating an airline ticket, the reservation system creates a file or document that contains all of the data associated with a prior art agent coupon. For example, such data includes but is not limited to the ticket number, the passenger's name and address, the passenger record number, the flight information, the date of the ticket, and the sales period ending date. The agent coupon data is given an identifier designation that will allow subsequent ease of retrieval. For example, the identifier can comprise the ticket number. The agent coupon data is then stored in a directory under the identifying designation as provided for by the software. The identifier designation can further include the passenger's name, and/or the passenger record number, and/or the sales period ending date, any one or all of which can be used to store the agent coupon data in a primary directory and sub-directories. For example, four separate primary directories can exist corresponding to the above identifiers, with each primary directory having three separate sub-directories comprising the other identifiers, all of which are automatically created by the software. or, a single primary directory can be used that is indexed by the passenger's record number. In this manner, any one or all of the identifiers can be used to subsequently retrieve the coupon data. [0021] In order to retrieve a particular agent coupon's data, the available identifier or identifiers are input to a retrieval screen brought up by an appropriate instruction to the software. The software then searches its data banks or directories and displays the directory or identifies the CD containing the identifier. If more than one identifier is input, the software again brings up the directory or identifies the CD containing the identifiers. An operator can then select the appropriate identifier which then brings up the coupon data from the hard drive of the storage apparatus 13 , or the operator loads the identified CD which then brings up the data. Alternatively, once the identifier or identifiers are input, the software searches the internal or external data banks and directories and directly brings up the coupon data associated with the same. The operator then prints the coupon data onto a paper copy. [0022] The above storage and retrieval apparatus and methods utilize the above described software program, which allows for the coupon information to be stored and retrieved in the manner described. It is to be understood that the indexing and directories, above described, can be varied without departing from the scope of the present invention. [0023] The described invention therefore provides methods, software and apparatus to electronically store agent coupon information and/or data which is generated when an airline ticket is prepared or when a batch data file is received, and then retrieve the coupon data at a later date and print a document which contains all of the coupon data and/or information. In the embodiments, above described, the initiation and activation of the retrieval method can be accomplished on or off the site of the storage apparatus, by for example the use of an internet/intranet connection using an appropriate internet browser and/or Adobe Acrobat Reader. [0024] While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breath and scope of the drawings and description provided herein.

Methods and apparatus provide for the electronic storage and retrieval of airline ticket agency data simultaneously with the generation of one or more airline tickets. The inventive methods and apparatus eliminate the prior art requirement of printing and storing hard copies of agent coupons.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of provisional patent Ser. No. 60/070,003 filed Mar. 19, 2008. [0002] Not applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0003] Not applicable INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC [0004] Not applicable BACKGROUND OF THE INVENTION [0005] 1. Field of Invention [0006] The present invention relates generally to the field of imaging in dense compressive media, and more particularly to a novel system and method of use thereof for imaging in medical soft tissue applications such as dermatology, orthopedics and bone fractures, and breast tumor scanning/detection and diagnosis/characterization. [0007] According to the U.S. National Library of Medicine and the National Institutes of Health, one in eight women will be diagnosed with breast cancer. One in sixteen women will die prematurely due to breast cancer. Breast cancer is more easily treated and often curable if it is discovered early. Breast cancer stages range from 0 to IV. The higher the stage number, the more advanced the cancer. According to the American Cancer Society (ACS), the 5-year survival rates for persons with breast cancer that is appropriately treated are as follows: 100% for Stage 0, 100% for Stage I, 92% for Stage IIA, 81% for Stage IIB, 67% for Stage IIIA, 54% for Stage IIIB, and 20% for Stage IV. Clearly, early detection is the primary factor in the successful treatment of breast cancer. Early breast cancer usually does not cause symptoms, therefore accentuating the importance of early detection devices and methods. [0008] 2. Discussion of Related Art [0009] The usefulness of methods and/or devices to perform breast cancer detection is well recognized. A variety of related art methods and/or devices are directed to the problem. However, each related art method and/or device possesses significant disadvantages. [0010] The principal methods of detecting breast cancer are clinical physical examination, self-examination, and X-ray mammography. Efforts have been made to develop alternative solutions to the problem of breast cancer detection and diagnosis, including magnetic resonance imaging (MRI) and microwave radar imaging. [0011] In a clinical physical examination, a doctor performs a tactile physical examination of the breasts, armpits, and the neck and chest area. The physical examination is intended to discover lumps indicative of cancer. However, the clinical physical examination cannot identify the nature of the lump and lacks the sensitivity or resolution of other methods. [0012] The breast self-examination is essentially the same as the clinical physical examination, but it is performed by the subject outside of the clinical environment. The breast self-examination is similar in benefit and limitation to the clinical physical examination. [0013] X-ray mammography is currently the only FDA-certified early breast cancer screening technology. X-ray mammography, in some cases, can detect breast cancers before they can be detected by a physical examination. One breast at a time is rested on a flat surface that contains an X-ray detection media; typically a film exposure plate or a digital imaging modality such as semiconductor detectors. A device called a compressor is pressed firmly against the breast to flatten the breast tissue. This results in substantial discomfort to the patient. The patient holds her breath as a series of X-ray images are taken from several angles. Deodorant, perfume, powders and jewelry must be removed to prevent blockage of the X-rays. In each examination, the patient is exposed to destructive ionizing radiation, thus incurring a risk of realizing an induced breast tumor. X-ray mammography is considered a health risk for women who are pregnant or breast-feeding, and it is not recommended for women under the age of fifty. Further, X-ray mammography is a poor method for early-stage cancer detection. In a recent study, only 52 percent of high-grade ductal carcinoma in situ (DCIS), the form most likely to develop into invasive cancer, were detected by X-ray mammography. “MRI for Diagnosis of Pure Ductal Carcinoma In Situ: A Prospective Observational Study,” Christiane Kuhl, et. al., The Lancet, vol. 370, issue 9586, 11 Aug. 2007, pages 485-492. [0014] Due to the limitations and disadvantages in these current methods, there exists an on-going search for other effective methodologies. Magnetic resonance imaging (MRI) and microwave radar are two solutions of interest. [0015] Magnetic resonance imaging (MRI) employs powerful magnets and radio waves to generate images inside the body. The magnetic field produced by an MRI is about ten thousand times greater than the Earth's magnetic field. The magnetic field polarizes the magnetic moment of hydrogen atoms in the body. When properly tuned radio waves are then transmitted through the body, they are differentially absorbed depending on the types of tissue encountered. The resulting radio signal can thus often distinguish healthy versus cancerous tissue. MRI represents a substantial improvement over X-ray mammography in terms of early screening, detecting 98 percent of high-grade DCIS compared with 52 percent detection by X-ray mammography, as noted in Kuhl, et al., “MRI for Diagnosis of Pure Ductal Carcinoma In Situ: A Prospective Observational Study,” Christiane Kuhl, et. al., The Lancet, vol. 370, issue 9586, 11 Aug. 2007, pages 485-492. [0016] While MRI offers improved screening accuracy over X-ray mammography and eliminates the risk associated with ionizing radiation, it also has significant disadvantages. Many patients find the MRI procedure uncomfortable. The patient may be required to fast from four to six hours prior to the scan. Then, the patient lies on a narrow table which slides into the middle of the MRI scanner. The MRI machine may induce anxiety in patients with a fear of confined spaces. Further, the MRI machine produces loud percussive and buzzing noises which may be disconcerting to the patient. Finally, because several sets of images are required, each taking from two to fifteen minutes, the patient must be exposed to the MRI environment for an hour or longer. The patient is required to lie motionless for this long period of time because excessive movement can blur MRI images and cause errors. In addition, because the magnet is very strong, certain types of metal can cause significant errors in the images, and the strong magnetic fields created during an MRI can interfere with certain medical implants. Persons with pacemakers or other metallic objects in the body, such as ear implants, brain aneurism clips, artificial heart valves, vascular stents and artificial joints should not be exposed to MRI. Finally, the high cost of procuring and operating an MRI machine, and the lack of technicians skilled in reading breast MRIs present additional disadvantages to its use. [0017] Research has turned to consideration of non-invasive ultrasound methods for screening and diagnosis, utilizing acoustic means for both excitation of the tissues and for measurement and imaging of the excited tissues. A publication by Alizad, et al., discusses one such acoustic method wherein a hydrophone is employed to detect the acoustic waves generated by the motion induced in the tissue. The detected acoustic waves are processed into imaging information. A. Alizad, M. Fatemi, L. E. Wold and J. F. Greenleaf, “Performance of Vibro-Acoustography in Detecting Microcalcifications in Excised Human Breast Tissue: A Study of 74 Tissue Samples,” IEEE Trans. Med. Imaging., vol. 23, pp. 307-312, March 2004. Hynyen, et al., U.S. Pat. No. 6,984,209 discloses another acoustic method which incorporates a pulse-echo ultrasound transceiver to perform the measurement and imaging function. Methods that rely upon acoustic measurement alone are disadvantaged by noise, contrast and speckle limitations, and by the necessity to trade off low-frequency penetration against high-frequency resolution. [0018] Microwave detection methods offer a factor of five improvement in detection sensitivity and diagnostic capacity over ultrasound methods. Microwave transmission is very sensitive to variations in media material permittivity, which may vary by a factor of five, while ultrasound sensitivity to these permittivity variations is less than ten percent. J. E. Joy, E. E. Penhoet and D. B. Petitti, “Saving Women's Lives: Strategies for Improving Breast Cancer Detection and Diagnosis,” Institute of Medicine and National Research Council, ISBN: 0-309-53209-4, 2005. Ultrasound methods rely on the measurement of variations in the mechanical properties of benign tissue and cancerous tumors, which are not large. On the other hand, microwave methods take advantage of the difference in dielectric constants associated with the water content of benign tissue and cancerous tumors, which vary dramatically. Therefore, research is turning to consideration of microwave radar devices and methods for soft tissue imaging. Microwave imaging offers a low-stress, low risk solution; requiring short exposure periods without the dangers or discomforts associated with X-ray mammography or MRI. The scientific principles are defined and experimental demonstration discussed in a publication by Li, et al., “Microwave Imaging via Space-Time Beamforming: Experimental Investigation of Tumor Detection in Multilayer Breast Phantoms,” Xu Li, et al., IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 8, August 2004. Li, et al., experimentally demonstrated the effectiveness of radar imaging principles in breast tumor detection applications employing a two-dimensional scanning methodology to synthesize a two dimensional antenna array. However, imaging methods that rely on microwave alone are disadvantaged by the necessity to trade off low-frequency penetration against high-frequency resolution. [0019] Because of the limitations associated with each individual screening, imaging and diagnosis method, research is considering combining multiple imaging modalities. Rosner, et al., U.S. Patent Application No. 2007/0276240 discloses a system which uses both acoustic and microwave methods for imaging. The ultrasound subsytem transmits ultrasound waves into the target and receives the echo. The microwave subsystem transmits a microwave signal into the target and receives the reflection. The ultrasound and microwave modalities operate independently. This simple integration of two modalities does not take advantage of the physical interaction of the ultrasound and microwave modalities. Therefore, this combined system possesses the disadvantages of each subsystem. It is difficult to concurrently achieve high penetration, high resolution, fast scanning and high contrast using either subsystem alone. BRIEF SUMMARY AND OBJECTS OF THE INVENTION [0020] In view of the foregoing disadvantages inherent in the known devices and methods in the related art, the present invention provides a novel multi-modality system and method for performing screening/detection, imaging and diagnosis/characterization of materials and objects in dense compressive media, particularly but not exclusively in medical soft tissue applications. Specifically, the present invention involves coupling an ultrasound subsystem for stimulating target tissues with a microwave subsystem for measuring the response of the stimulated target tissues. The present invention involves a true hybrid integration of the ultrasound and microwave modalities, taking advantage of the best attributes of each subsystem modality. The superior resolution and focus characteristics of high-frequency ultrasound input waves are employed to excite Doppler displacements of materials in the target breast. At the same time, the superior penetration and high diagnostic contrast capabilities of the microwave modality are employed to perform the diagnosis an imaging function. The present invention enhances early detection and diagnosis capability without the disadvantages of the related art systems and methods. [0021] Low cost is achieved by enabling application of low-cost components, such as compact radio frequency components developed for the wireless communications industry and existing ultrasound application components. [0022] In one embodiment of the present invention, the complexity, cost and time associated with mechanical scanning is avoided by employing an ultrasound transducer array in place of scanning ultrasound transducers. [0023] The present invention enables achievement of a small form factor, relative to MRI and X-ray devices, to reduce cost and enhance flexibility and convenience. [0024] The present invention enables three-dimensional detection and diagnosis imaging. In one alternative embodiment of the present invention, ultrasound and microwave subsystem combinations are implemented in multiple axes. These multi-axis subsystems cooperate to provide superior three-dimensional imaging capability. In yet another embodiment, phased array operation of the ultrasound subsystem allows mapping of two-dimensional planes of varying depths within the target breast. These two-dimensional maps may be integrated to create three-dimensional images. [0025] The present invention minimizes patient discomfort attendant to related art systems and methods. The present invention requires merely soft compression to maintain contact between the target breast and the ultrasound transducer and microwave antenna, eliminating the discomfort associated with X-ray mammography breast compression. In addition, stress associated with ionizing radiation exposure is eliminated. Further, the relatively simple apparatus and short imaging time enabled by the present invention eliminates the discomfort associated with long exposure to the confining and noisy environment of MRI apparatuses. [0026] The present invention eliminates health risks associated with related art systems and methods. The present invention eliminates the risk of short-term or long-term deleterious affects associated with ionizing radiation exposure in X-ray mammography, and the risks associated with exposure to powerful magnetic fields in MRI. [0027] Other advantages of the present invention will become readily apparent to those with skill in the art from the following figures, descriptions and claims. As will be appreciated by those of skill in the art, the present invention may be embodied as an apparatus, systems or methods. It is intended that such other advantages embodied as other apparatus, systems and methods be included within the scope of this invention, and the examples set forth herein shall not be limiting. BRIEF DESCRIPTION OF THE DRAWINGS [0028] The nature of this invention, as well as all its objects and advantages, will become readily apparent and understood upon reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein: [0029] FIG. 1 shows the orientation of the system with respect to the patient and the imaging target breast in one preferred embodiment of the present invention. [0030] FIG. 2 provides a schematic representation of the ultrasound subsystem. [0031] FIG. 3 provides a schematic representation of the microwave imaging subsystem. [0032] FIG. 4 shows the microwave transmission into the target breast, and the resultant display of the reflected microwaves, prior to activation of the ultrasound subsystem. [0033] FIG. 5 shows the ultrasound wave transmission through the subject breast, the resultant displacement of the target tumor, and the display of the reflected microwaves resulting from the ultrasound stimulation of the tumor. [0034] FIG. 6 presents an alternative embodiment of the ultrasound subsystem featuring an ultrasound transducer array. [0035] FIG. 7 presents an alternative embodiment of the ultrasound subsystem featuring a focused ultrasound wave pulse. [0036] FIG. 8 presents an alternative embodiment of the present invention employing paired ultrasound transducers and microwave antennas in multi-axis orientations. [0037] FIG. 9 shows an alternative embodiment of the present invention implementing both the ultrasound transducer and the microwave antenna on the same side of the subject breast. [0038] FIG. 10 presents alternative scanning approaches. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0039] The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Further, while a breast is used in the description of these embodiments, it is to be noted that any turbid medium may be processed with this invention. Thus the present invention shall not be limited to the examples disclosed. The scope of the invention shall be as broad as the claims will allow. [0040] Referring now to the drawings, FIG. 1 shows the orientation of the system with respect to the patient 1 and the imaging target breast 2 in one preferred embodiment of the present invention. An ultrasound subsystem 10 and a microwave imaging subsystem 30 are employed in combination to detect and diagnose tumors in the breast 2 . An ultrasound transducer 22 and a microwave antenna 36 are oriented with respect to the target breast 2 of the patient 1 . In one preferred embodiment, the ultrasound transducer 22 is oriented along the same axis, the Z-axis, as the microwave antenna 36 : the ultrasound transducer 22 aimed in the negative z direction and the microwave antenna 36 aimed in the positive Z direction. A radio frequency transceiver 40 generates and transmits microwave signals to the microwave antenna 36 . The microwave antenna 36 transmits microwaves into the target breast 2 . Reflected microwaves are collected by the microwave antenna 36 and received by the radio frequency transceiver 40 . A computer/signal and data processor 50 containing signal processing circuitry and data processing algorithms processes the output of the radio frequency transceiver 40 and sends the resultant data to the display 60 for access by the technician. The display 60 may be a video screen, a printing device, a photographic device, an oscilloscope, a spectrum analyzer, or any useful medium for communicating system output to the technician. The data may be usefully represented as individual spectra, one-dimensional line scans, two-dimensional cross-sectional constructions, or volume images. A scan controller/actuator 18 working in combination with a mechanical actuator 20 orients the ultrasound transducer 22 to enable scanning of the entire target breast 2 . An ultrasound electronics assembly 12 generates and transmits ultrasound waves to the ultrasound transducer 22 . The ultrasound transducer transmits the ultrasound waves to the target breast 2 to stimulate the tissues therein. [0041] FIG. 2 provides a schematic representation of the ultrasound subsystem 10 . An ultrasound electronics assembly 12 is shown housing a waveform generator 14 and a power amplifier 16 . The waveform generator 14 produces an input ultrasound waveform. The power amplifier 16 conditions the input ultrasound waveform and transmits said ultrasound waveform to the ultrasound transducer 22 . The ultrasound transducer 22 transmits the amplified input ultrasound wave 8 into the target breast 2 . To maximize transmission of the ultrasound wave 8 into the breast, an ultrasound conductive gel may be used at the interface of the ultrasound transducer 22 and the target breast 2 . In a preferred embodiment of the present invention, the ultrasound transducer 22 must be physically relocated to perform a scan of the entire breast 2 . This scanning function is performed by a scan controller/actuator 18 working in combination with a mechanical actuator 20 . [0042] FIG. 3 provides a schematic representation of the microwave imaging subsystem 30 comprising an RF subsystem 32 , a computer/data processor 50 and a display 60 . The RF subsystem 32 comprises an RF antenna 36 , a coupler 34 , and an RF transceiver 40 . The RF transceiver 40 comprises a waveform generator 42 , a power amplifier 44 , an amplifier 46 and a mixer 48 . The waveform generator 42 produces an input waveform. The power amplifier 44 conditions the input waveform and transmits said waveform through the RF coupler 34 to the RF antenna 36 . The RF antenna 36 transmits the microwave 6 into the target breast 2 . To efficiently transmit the microwave 6 to the breast 2 , the RF antenna 36 is in physical contact with the breast 2 . In a preferred embodiment of the present invention, the RF antenna 36 is made from a material that closely matches the dielectric constant of the breast 2 . In an alternative embodiment, a dielectrically loaded antenna, in which the antenna 36 is embedded in a material that matches the dielectric constant of the breast 2 , may be employed to reduce reflections. Due to the wide propagation angle of the microwave 6 in the breast 2 , it is not necessary to move the RF antenna to scan the breast 2 . However, an alternative embodiment of the present invention may employ an RF antenna 36 scanning means, if desired. Microwaves reflected by normal/cancerous tissue boundaries and/or inclusions are collected by the microwave antenna 36 and transmitted through the coupler 34 to an amplifier 46 . Input waveforms from the waveform generator 42 and reflected microwaves from the amplifier 46 are passed through a mixer 48 and conveyed to an analog-digital processor 52 . Data processing algorithms 54 such as demodulation, and lockin detection or fast Fourier transform algorithms operate on the digital data from the analog-digital processor 52 . The resultant frequency and power data is transmitted to a display 60 for viewing by the technician. [0043] FIG. 4 shows the microwave 6 transmission into the target breast 2 , and the resultant display of the reflected microwaves, at time t 0 prior to activation of the ultrasound subsystem 10 . In one preferred embodiment of the present invention, a continuous microwave 6 is employed. It is anticipated that other input waveforms and methods, such as frequency modulation and pulse-delay, may be usefully employed to reduce clutter signals and improve the probability of tumor detection. The microwave 6 is transmitted by the RF antenna 36 into the breast 2 . Prior to activation of the ultrasound subsystem 10 , microwaves will be reflected back to the RF antenna 36 from the internal boundaries of the breast and from inclusions in the breast 2 such as a tumor 4 . The reflected microwaves will be of the same frequency as the transmitted input microwaves 6 . The reflected microwave will appear on the display 60 as a power spike 62 at the frequency of the transmitted wave. No position or shape information of the tumor 4 is detectable prior to activation of the ultrasound subsystem 10 . [0044] FIG. 5 shows the ultrasound wave 8 transmission through the subject breast 2 , the resultant displacement of the target tumor 4 , and the spectral representation of the reflected microwaves 6 resulting from the ultrasound stimulation of the tumor 4 . At time t 0 , no ultrasound waves have been transmitted into the breast 2 . The tumor 4 is at rest at location z 0 . A continuous microwave is transmitted into the breast 2 and reflections from the boundary of the breast 2 and the tumor 4 are displayed as a power spike 62 at the same fundamental frequency as that of the input microwave 6 . At time t 1 , an ultrasound wave 8 is introduced into the breast 2 . In one preferred embodiment of the present invention, the ultrasound transducer 22 lens is designed to create a collimated ultrasound wave 8 which propagates essentially in a column through the breast 2 . The ultrasound wave 8 travels at a significantly lower rate of speed than the microwave 6 . At time t 2 , the ultrasound wave impacts the tumor 4 and displaces said tumor 4 to location z 2 . As the ultrasound wave passes the tumor 4 , the tumor oscillates between location z 2 and z 0 before coming to rest again at essentially the initial location z 0 . As the tumor 4 oscillates between position z 0 and position z 2 , the Doppler effect results in a shift in the frequency of the reflected microwave. These frequency shifts appear on the display 60 as frequency sidebands 64 . Presence of these sidebands indicates the presence of a tumor 4 . The sidebands 64 are short lived, essentially lasting for the duration of the ultrasonic pulse passing through the tumor 4 . [0045] The power of the sidebands is determined through displacement analysis. If a signal is reflected off of a target whose range is changing with time according to r(t)=r 0 +Δr(t), the received signal can be written as: [0000] s ( t )=cos [ω c t+ 2 π−Δr ( t )/λ+φ 0 ] [0046] Where ω c is the carrier frequency and φ 0 is the phase [0047] For a small-amplitude oscillation of a target with a displacement d and a modulation frequency fm, the range is given by: [0000] Δ r ( t )= d sin(ω m t ) [0048] And thus the signal becomes [0000] s ( t )=cos [ω c t+ 2π−( d/ λ)sin(ω m t )+φ 0 ] [0049] For d<<λ, this expression is simply the narrowband FM situation: [0000] f  ( t ) =  cos  [ ω c  t + ( d  /  λ )  sin  ( ω m  t ) ] =  cos  ( ω c  t )  cos  ( ( d  /  λ )  sin  ( ω m  t ) ) - sin  ( ω c  t )  sin  ( ( d  /  λ )  sin  ( ω m  t ) ) =  cos  ( ω c  t ) - ( d  /  2   λ )  [ cos  ( ω c  t - ω m  t ) - cos  ( ω c  t + ω m  t ) ] [0050] Each sideband is smaller than the carrier by: [0000] P sideband =10 log( d 2 /4 λ 2 )=20 log(π f c d/c ) dBc. [0000] Radio frequency sensitivity is determined by the equation: [0000] Sensitivity= NF+KT+ 10 log( BW )+ SNR -10 log(Average) Where [0051] NF: The receiver input referred noise figure (Typically 3-5 dB) [0052] KT: Thermal noise power density (−174 dBm/Hz) [0053] BW: Receiver noise bandwidth in Hz (typically1-2 MHz) [0054] SNR: Required detector SNR in dB (20 dB) [0055] Average: Coherently collected samples over sample time [0056] If sensitivity is not sufficient, and to give system sensitivity a boost, a continuous wave may be employed such that: [0000] Sensitivity= NF+KT+ 10 log( BW )+ SNR -10 log(Average)−10 log(gain) Where [0057] gain: gain achieved due to applying continuous wave [0058] FIG. 6 prevents an alternative embodiment of the ultrasound subsystem 10 featuring an array of ultrasound transducers 22 . Use of an array of transducers 22 is an alternative to scanning with a single ultrasound transducer 22 . In this alternative, the design and operational complexities of a scanning system are traded against the design and operational complexity of a fixed array. A 4×4 array is shown for illustrative purposes. It is obvious and anticipated that arrays of various sizes may be usefully employed. [0059] FIG. 7 presents an alternative embodiment and operation of the ultrasound subsystem 10 . FIG. 7 a shows the ultrasound transducer 22 designed to generate a collimated ultrasound wave 8 . This configuration is used to perform the detection function. Upon detection of a tumor 4 , an ultrasound transducer 22 designed to generate a focused ultrasound wave 9 is located such that the focal point of the ultrasound wave 9 is concentrated on the tumor 4 as shown in FIG. 7 b. This configuration is used to perform the diagnosis function, enabling higher resolution definition of tumor size and shape, and the presence of multiple tumors. [0060] FIG. 8 presents an alternative embodiment of the present invention employing paired ultrasound transducers 22 and microwave antennas 36 in multi-axis orientations. This configuration enhances detection of multiple tumors, particularly in the case where one or more tumors would be in the shadow of another tumor in a single-axis detection configuration. For illustrative purposes, one transducer 22 /antenna 36 pair is shown oriented along the Z-axis working in combination with another transducer 22 /antenna 36 pair oriented along the X-axis. [0061] FIG. 9 shows an alternative embodiment of the multi-modality imaging system implementing both the ultrasound transducer 22 and the microwave antenna 36 on the same side of the subject breast 2 . For illustrative purposes, a single microwave antenna 36 is depicted with an array of ultrasound transducers 22 . An alternative embodiment is to replace the array of ultrasound transducers 22 with a single ultrasound transducer 22 which is actuated to scan the target breast 2 . These alternative configurations enable simplified apparatus design. [0062] FIG. 10 presents alternative scanning approaches. FIG. 10 a illustrates a representative x-y planar scanning scheme wherein the ultrasound transducer 22 is moved sequentially from station to station in the X-Y plane as shown for an exemplary 4×4 scanning matrix. In this scheme, the ultrasound transducer 22 transmits ultrasound waves 8 at each sequential location. FIG. 10 b illustrates an alternative scanning scheme wherein the ultrasound transducer 22 is transmitting continuously as it is moved in circular paths of increasing diameter. In this example, the ultrasound transducer 22 begins operation at point A, is indexed to point B, follows path B, then is indexed to point C and follows path C. Other continuous-scan patterns may be employed, such as moving the ultrasound transducer 22 in a continuously-increasing spiral pattern in the X-Y plane. [0063] Various embodiments of the present invention may be exercised in ways other than those illustrated in the examples shown in the Figures. Such alternative embodiments are within the contemplation of the present invention. The examples are not intended to limit the scope of this invention, which shall be as broad as the claims will allow. [0064] In addition, the present invention may be adapted to a variety of applications in both medical and non-medical fields. The field of medical soft tissue imaging includes orthopedics, dermatology, breast tumor screening/detection, imaging and diagnosis/characterization, and other medical applications. Such alternative applications are within the contemplation of the present invention and the scope of the invention shall be as broad as the claims allow. [0065] The physical implementation of the present invention may be varied without departing from the spirit of the invention. Elements and components may be implemented, added, interchanged, combined and/or packaged in a variety of embodiments. Various changes may be effected in structure, design, choice of components and materials, etcetera without departing from the spirit of the present invention. Such alternative embodiments, elements and implementations are within the contemplation of the present invention and the scope of the invention shall be as broad as the claims allow. [0066] Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by their legal equivalents, and shall be as broad as the claims will allow. [0067] The following references are of utility in understanding the foregoing specification, and are incorporated herein by reference: [0068] Christiane Kuhl, et. al., “MRI for Diagnosis of Pure Ductal Carcinoma In Situ: A Prospective Observational Study,” The Lancet, vol. 370, issue 9586, 11 Aug. 2007, pages 485-492. [0069] Li, Xu, et. al. (2004): “Microwave Imaging via Space-Time Beamforming: Experimental Investigation of Tumor Detection in Multilayer Breast Phantoms,” IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 8, pp 1856-1865. [0070] Nanda, R. (2007): “Breast Cancer,” Medline Plus Medical Encyclopedia, the U.S. National Library of Medicine and the National Institute of Health, <http://www.nlm.nih.gov/medlineplus/ency/article/000913.htm>. [0071] A. Alizad, M. Fatemi, L. E. Wold and J. F. Greenleaf, “Performance of Vibro-Acoustography in Detecting Microcalcifications in Excised Human Breast Tissue: A Study of 74 Tissue Samples,” IEEE Trans. Med. Imaging., vol. 23, pp. 307-312, March 2004. [0072] J. E. Joy, E. E. Penhoet and D. B. Petitti, “Saving Women's Lives: Strategies for Improving Breast Cancer Detection and Diagnosis,” Institute of Medicine and National Research Council, ISBN: 0-309-53209-4, 2005. [0073] C. Maleke, J. Luo and E. E. Konofagou, “2D Simulation of the Harmonic Motion Imaging (HMI) With Experimental Validation,” IEEE Ultrasonics Symposium, pp. 797-800, 2007. [0074] E. E. Konofagou, M. Ottensmeyer, S. L. Dawson and K. Hynynen, “Harmonic Motion Imaging—Applications in the Detection of Stiffer Masses,” IEEE Ultrasonics Symposium, pp. 558-561, 2003. [0075] Reinberg, Steven (Aug. 10, 2007): “MRI Beats Mammograms at Spotting Early Breast Cancer,” HealthDay News <http://www.healthday.com/Article.asp?AID=607199>.

A multi-modality system and method for performing screening/detection, imaging and diagnosis/characterization of materials and objects in dense compressive media, such as in medical soft tissue applications, is disclosed. Medical tissue applications include but are not limited to the detection and diagnosis of breast tumors. Generally, the present invention involves coupling an ultrasound subsystem for exciting target tissues with a microwave subsystem for measuring the response, imaging and diagnosing the target tissues.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Application No. 61/682,565, filed Aug. 13, 2012, the entire disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates generally to the field of mobile devices and, in particular, to displaying unsolicited content on mobile devices, and associated systems and methods. BACKGROUND OF THE INVENTION [0003] Mobile devices capable of wireless data communication, including communication to the Internet, are in widespread use around the world. Such devices include cell phones, smart phones, tablet personal computers (PCs), notebook computers, and personal digital assistants (PDAs). Typically, mobile devices support communication applications such as web browsers and email clients. Because of their growing popularity and geographic reach, mobile devices represent a sought-after medium for unsolicited content providers such as advertisers. However, the design of these mobile devices and of the service delivery systems that support them come with trade-offs in terms of device display size, on-board computing resources, and data transmission bandwidth. [0004] One key to portability of a mobile device is small size. Because of this design limitation, a mobile device typically presents limited screen area, or “real estate,” for the display of a user interface. One approach to conforming to the display requirements for such a device is to reduce the area of displayed objects (e.g., graphical icons, application windows). However, shrinking a display object fails when the user of a mobile device can no longer visually discern information from that object. Furthermore, devices that employ a touch screen (“swiping”) interface rather than a keyboard or other off-screen pointing device must size and organize display objects to support physical manipulation via the display. This interface requirement further limits the practicality of shrinking display objects, putting even more of a premium on available screen real estate. Given the current state of the mobile device design, small screen sizes mean that every display object competes for limited screen real estate with other content. Because cluttering of a user interface on a mobile device can compromise the user experience, unsolicited content such as advertising is not typically of high priority for display. [0005] The small overall size of a mobile device can also drive design decisions to limit the device's on-board computing resources, such as memory capacity, processing speed, and storage space. Consequently, too many applications executing simultaneously and competing for limited computing resources can perceptibly degrade the performance of a mobile device. Also, data transmission bandwidth may be limited by the design of a particular mobile device and/or by the network coverage provided by a wireless carrier (for example, service by a 3G versus 4G data network). Therefore, the user experience with mobile applications that require wireless data transmission can be degraded by network bottlenecks that manifest as slow response times. Both of these performance pressures work against the introduction of processes to deliver unsolicited content to mobile devices. Nonetheless, various approaches to handling delivery of unsolicited content to mobile devices exist in the state of the practice. [0006] U.S. Pat. No. 6,985,933 to Singhal et al discloses use of a wireless device to pre-fetch contents from web sites identified as most likely to be requested by a user of the device in a given environment, thus making the content available for rapid retrieval at the device. Pre-fetching is scheduled during times when data transmission bandwidth to and from the device is not in use in order to speed responsiveness of the device. However, the disclosed solution does not address display of pre-fetched content unless requested by the user of the device. [0007] U.S. Pat. No. 6,363,419 to Martin et al. discloses a system for displaying content on a wireless computing device during periods when processing on the device itself is otherwise idle. Content is displayed via a browser program, and may include advertising from a service provider or from third parties. However, the reference does not disclose display of unsolicited content during periods when the mobile device is experiencing latency in an actively processing (not idle) application. [0008] U.S. Published Patent Application No. 2011/828288 by Kharebov et al. discloses playing an advertisement to a user of the mobile device while the user is waiting for content to download. Advertisement content may be pre-fetched in anticipation of a future delay related to accessing a network resource. However, the Kharebov reference initiates an advertisement process as a new display object that competes for screen real estate with existing objects. [0009] There exists a need to deliver and display unsolicited content on mobile devices within the limits of existing screen real estate, and without compromising the experience of the mobile device user. This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention. SUMMARY OF THE INVENTION [0010] With the foregoing in mind, embodiments of the present invention provide a system and method for using existing mobile device display real estate to display unsolicited content, such as advertisements. To minimize any obtrusion of the user experience, unsolicited content may be pre-loaded for display in temporarily unused portions of a mobile device display during periods of latency in active mobile applications. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIG. 1 is a block diagram illustrating a system for delivery of unsolicited content to a mobile device according to an embodiment of the present invention. [0012] FIG. 2 is a block diagram illustrating a scheduling and display component of a system for delivery of unsolicited content on a mobile device according to an embodiment of the present invention. [0013] FIG. 3 is a flowchart illustrating a method aspect of an embodiment of the present invention for delivery of unsolicited content on a mobile device. [0014] FIG. 4 is a flowchart illustrating a method aspect of an embodiment of the present invention for delivery of unsolicited content on a mobile device. [0015] FIG. 5 is a diagram illustrating a screen shot of a system interface of the system illustrated in FIG. 1 . [0016] FIG. 6 is a flowchart illustrating a method aspect of an embodiment of the present invention for delivery of unsolicited content on a mobile device. [0017] FIGS. 7A , 7 B, 7 C, and 7 D are diagrams illustrating a changing state of a mobile device user interface during display of unsolicited content as implemented by the system illustrated in FIG. 1 . [0018] FIG. 8 is a block diagram illustrating a diagrammatic representation of a machine in the example form of a computer system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0019] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Those of ordinary skill in the art will realize that the following embodiments of the present invention are only illustrative and are not intended to be limiting in any way. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Like numbers refer to like elements throughout. [0020] In this detailed description of the present invention, a person skilled in the art should note that directional terms, such as “above,” “below,” “upper,” “lower,” and other like terms are used for the convenience of the reader in reference to the drawings. Also, a person skilled in the art should notice this description may contain other terminology to convey position, orientation, and direction without departing from the principles of the present invention. [0021] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure. [0022] Example methods and systems for unsolicited content display during latency on mobile devices are described herein below. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of example embodiments. It will be evident, however, to one of ordinary skill in the art that the present invention may be practiced without these specific details and/or with different combinations of the details than are given here. Thus, specific embodiments are given for the purpose of simplified explanation and not limitation. [0023] Referring now to FIGS. 1-8 , a system 100 for displaying unsolicited content during latency on mobile devices 110 according to an embodiment of the present invention is now described in greater detail. Throughout this disclosure, the present invention may be referred to as an unsolicited content display system 100 , a UCD system 100 , a computer program product, a computer program, a product, a system, a tool, and a method. Those skilled in the art will appreciate that this terminology does not affect the scope of the invention as outlined herein. [0024] In the following disclosure, the present invention may be referred to as relating to unsolicited content, adverts, advertisements, marketing campaigns, and ads. Those skilled in the art will appreciate that this terminology is only illustrative and does not affect the scope of the invention. For instance, the present invention may just as easily relate to electronic coupons, political messages, public service announcements, or informational broadcasts. [0025] Referring initially to FIG. 1 , an unsolicited content display (UCD) system 100 according to an embodiment of the present invention is now described in greater detail. The UCD system 100 may include a carrier server 160 that may be adapted to be used in connection with a mobile network 180 to position the carrier server in communication with a mobile device 110 . The mobile device 110 may be a computerized device, such as a cell phone, smart phone, notebook computer, a tablet personal computer (PC), a personal digital assistant (PDA). The carrier server 160 may be in communication with the mobile device 110 so that digital information may be transmitted from the carrier server to the mobile device. [0026] The carrier server 160 and the mobile device 110 may be connected to the mobile network 180 via a server, a network interface device, or any other device capable of making such a connection. Alternatively, or in addition, the mobile device 110 may be configured to be connected with a network 170 , such as the Internet, via a hotspot 112 , for example, that may employ a router connected to a link to a network. For example, and without limitation, the mobile device 110 may be connected to the Internet by a network interface device implemented as a wireless fidelity (WiFi) workstation 112 . The network interface device 112 may be any type of network interface device, including, without limitation, an Ethernet card and a wireless communication device such as an 802.11/WiFi network interface or a Wireless LAN device. The mobile network 180 may be any type of cellular network device, including GSM, GPRS, CDMA, EV-DO, EDGE, 3G, DECT, OFDMA, WIMAX, and LTE communication devices. These and other communication standards permitting connection to a network 170 , such as the Internet, are included within the invention. Moreover, other communication standards connecting the mobile device 110 with an intermediary device that is connected to the Internet, such as USB, FireWire, Thunderbolt, and any other digital communication standard is included within the invention. [0027] The carrier server 160 may include a staging database 168 . The staging database 168 may include digital information in the form of unsolicited content, such as advertisements, pictures, figures, text, videos, audio recordings or any other digital content. A service provider 162 may manage or otherwise manipulate the unsolicited content in the staging database 168 by interacting with the delivery manager 166 via a system interface 164 . Upon recognition by the delivery manager 166 that a mobile device 110 is ready to receive unsolicited content, the delivery manager 166 may transmit unsolicited content included by the staging database 168 to the mobile device 110 via the mobile network 180 or via the network 170 through network interface device 112 . Due to increased costs and data limits associated with transmission over some network connections, for instance, cellular network connections, transmission of unsolicited content may be limited to transmission across non-cellular networks 170 . [0028] In one embodiment of the present invention, unsolicited content may be transmitted from an advertiser host 140 to the carrier server 160 to be staged in the staging database 168 for subsequent delivery to a mobile device 110 . The advertiser host 140 may include an advert manager 142 having an associated advert database 144 that includes unsolicited content, such as advertisements, that is specific to the business entity that controls the advertiser host 140 . From an advertiser workstation 120 , an advertiser 122 may manage or otherwise manipulate the unsolicited content in the advert database 144 by using a system interface 124 to interact with the advert manager 140 through an advert client 128 . For example, and without limitation, a local area network (LAN) 130 may support communication between the advert client 128 and the advert manager 142 . [0029] The advert manager 142 may be configured to be in communication with the carrier server 160 , or with the mobile device 110 , or both. The advert manager 142 may be in communication the mobile device 110 and/or the carrier server 160 across a network 170 via a network interface substantially as described above for the carrier server 160 and the mobile device 110 . Moreover, the advert manager 142 may optionally be configured to function as an intermediate device between the mobile device 110 and the carrier server 160 . In such a case, any request for unsolicited content from the mobile device 110 may be received by the advert manager 142 and re-transmitted to the carrier server 160 . [0030] In another embodiment of the present invention, unsolicited content may be transmitted from a campaign server 150 to the carrier server 160 to be staged in a staging database 168 for subsequent delivery to a mobile device 110 . The campaign server 150 may include a campaign manager 156 having an associated campaign database 158 that includes unsolicited content, such as advertisements, received from an advertising customer and managed by a campaign advisor 152 . For example, and without limitation, an advertiser 122 may use a system interface 124 to access a campaign client 126 on an advertiser workstation 120 to create adverts for inclusion in an advertising campaign. A network 170 , such as the Internet, may support communication between the campaign client 126 and the campaign manager 156 . [0031] The campaign manager 156 may be configured to be in communication with the carrier server 160 , or with the mobile device 110 , or both via a network 170 that may employ a network interface substantially as described above for the carrier server 160 and the mobile device 110 . Moreover, the campaign manager 156 may optionally be configured to function as an intermediate device between the mobile device 110 and the carrier server 160 , wherein any request for unsolicited content from the mobile device 110 may be received by the campaign manager 156 and re-transmitted to the carrier server 160 . [0032] The delivery, scheduling, and display functions of the unsolicited content display (UCD) system 100 will be described individually in greater detail below. Delivery [0033] Referring now to flowchart 300 of FIG. 3 , the operation of the delivery function of the UCD system 100 will be discussed in greater detail. More specifically, the relationship between the carrier server 160 , the mobile device 110 , and the operational steps of unsolicited content delivery will now be discussed. The following illustrative embodiment is included to provide clarity for one operational method that may be included within the scope of the present invention. A person of skill in the art will appreciate additional databases and operations that may be included within the UCD system 100 of the present invention, which are intended to be included herein and without limitation. [0034] From the start, the operation may begin at Block 310 , where an advertiser 122 may choose to create unsolicited content, for example, in the form of an advertisement, designed for display on a mobile device 110 . More specifically, the unsolicited content included in the staging database 168 may be formatted, proportioned, or otherwise configured to be displayed on an electronic visual display of the mobile device 110 that is of a size typically found on a mobile computerized device such as a smart phone, tablet personal computer (PC), personal digital assistant (PDA), or notebook computer. Desirously, the unsolicited content may be created so as to not require re-formatting to conform to the display requirements and limitations of a mobile device 110 . The advertiser 122 may tag the unsolicited content (Block 320 ) with meta-data such as, and without limitation, product type, creation date, originator, digital file size, target market, and vendor identifier. [0035] At Block 330 , the advertiser 122 may choose to populate one or more source databases with newly created unsolicited content. For example, and without limitation, the source databases may include an advert database 144 and/or a campaign database 158 . The unsolicited content may be staged (Block 340 ) for download from the staging database 168 on the carrier server 160 . [0036] Upon the occurrence of a triggering event (Block 350 ), such as a request originating from a mobile device 112 , the delivery manager 166 may deliver unsolicited content (Block 360 ) by transmitting the unsolicited content to the mobile device 110 across an available network 112 , 180 . The unsolicited content delivered to the mobile device 110 may include, for example and without limitation, one or more advertisements. A triggering event may be recognition of readiness of a mobile device 110 to receive unsolicited content, or any action taken by the mobile device 110 , the user of the mobile device 110 , or delivery manager 166 that would indicate the transmission of unsolicited content to the mobile device 110 . For example, and not by limitation, the triggering event may be the client device turning on, web browsing software opening, an application or program opening, a web page being visited, a download initiating, connection to a network 112 , 180 being made, or unsolicited content being removed from a mobile device 110 . When one or more such triggering events occur, the mobile device 110 may accept transmittal of unsolicited content from the staging database 168 through the delivery manager 166 . Alternatively, the triggering event may originate at the client server 160 . For example, and without limitation, the triggering event may be the addition of new unsolicited content to the staging database 168 , removal of unsolicited content from the staging database 168 , or modification of unsolicited content on the staging database 168 . When one of these staging database 168 triggering events occur, the delivery manager 166 may transmit a signal to the mobile device 110 indicating the availability of unsolicited content for delivery to the mobile device 110 . In response, the mobile device 110 may allow transmittal of the unsolicited content (Block 360 ) from the delivery manager 166 . [0037] The delivery manager 166 may gather data (Block 365 ) related to a mobile device 110 to which a delivery (Block 360 ) is accomplished. For example, and without limitation, when a delivery manager 166 detects a triggering event (Block 350 ) such as a request for unsolicited content from a mobile device 110 , the delivery manager 166 may create a user account associated with the mobile device 110 which may comprise information related to the mobile device 110 including, without limitation, device specifications such as electronic visual display dimensions and resolution, processing power, graphical processing power, network connection devices, estimated network connection bandwidth, storage space, memory, and operating system(s) and software installed on the mobile device 110 . The user account may then be stored (Block 365 ) on the staging database 168 , such that each time the mobile device 110 requests unsolicited content, this information may not need to be re-collected by the delivery manager 166 . The data gathered at Block 365 may include further information, including, but not limited to, demographic information related to a user of the mobile device 110 , browsing history of the mobile device, and current and historic geographic location of the mobile device. The delivery manager 166 may periodically check the information and determine whether the information associated with a user account is accurate. If not, the information stored in the user account may be updated. [0038] Continuing with the preceding example, when the delivery manager 166 detects a triggering event (Block 350 ) such as a request for download of unsolicited content from a mobile device 110 for which a user account exists, or after a creation of a user account in response to the request, the delivery manager 166 may select unsolicited content from the staging database 168 based upon the information contained in the request from the mobile device 110 . For example, and without limitation, if the request includes an indication that the mobile device 110 has visited the website associated with a specific vendor, the delivery manager 166 may select content associated with the specific vendor from the staging database 168 and deliver unsolicited content. As another example, if the request includes information indicating the mobile device 110 is currently, or historically has been, in the vicinity of a business location of a specific vendor, the delivery manager 166 may select and deliver unsolicited content associated with the specific vendor. In yet another example, if the request includes information indicating the dimensions and/or resolution of an electronic visual display of the mobile device 110 , the delivery manager 166 may select and deliver unsolicited content that is formatted to be displayed on displays with the same or similar dimensions and/or resolutions as indicated in the request. [0039] At Block 370 , the delivery manager 166 may collect metrics related to unsolicited content delivery activity per Block 360 (or, alternatively, to the absence of delivery activity per Block 355 ). At Block 380 , the delivery manager 166 may analyze metrics collected at Block 370 to ascertain if a campaign to deliver unsolicited content (e.g., an advertising campaign) is complete (Block 380 ). For example, and without limitation, the delivery manager 166 may determine if campaign objectives have been met by comparing actual delivery metrics to the campaign duration, the deliveries count, and/or sales target established during planning of the campaign. A campaign may be declared complete based on success or on failure to achieve campaign objectives. This analysis by the delivery manager 166 may have a human in the loop, for example, a service provider 162 working through a system interface 164 on a carrier server 160 , a campaign advisor 152 using a system interface 154 to work through a campaign manager 156 on a campaign server 150 , and/or an advertiser 122 using a system interface 124 to work through a campaign client 126 on an advertiser workstation 120 . Alternately, and preferably, this analysis may be automated so that certain metrics relating to campaign success are analyzed and compared against data that is collected relating to display of the unsolicited content. These metrics may, for example, be rules, and compliance with the rules may dictate whether or not the campaign has been successful, i.e., whether or not a campaign is complete. [0040] If it is determined at Block 380 that the campaign is not complete, then it may be determined at Block 382 whether or not an update to the campaign is necessary. For example, the delivery manager 166 may be used either to continue an incomplete campaign without changes, or to update unsolicited content in an incomplete campaign. This decision process by the delivery manager 166 may be automated in that the decision on whether or not updated campaign may be made based on various metrics, i.e., rules. In some instances, this decision process by the delivery manager 166 may have a human in the loop, including, for example, a service provider 162 working through a system interface 164 on a carrier server 160 , a campaign advisor 152 using a system interface 154 to work through a campaign manager 156 on a campaign server 150 , and/or an advertiser 122 using a system interface 124 to work through a campaign client 126 on an advertiser workstation 120 . Accordingly, if it is determined at Block 382 that the campaign is to be updated, then updating of the campaign may entail editing of the unsolicited content itself (Block 384 ) and/or editing the meta-data tags describing the unsolicited content (Block 386 ). The appropriate source databases may then be repopulated with the updated campaign content (Block 330 ). If, however, it is determined at Block 382 that no update to the campaign is necessary, then the system may continue to await a triggering event, such as receipt of a download request, at Block 350 . [0041] If it is determined at Block 380 that a campaign is complete, then unsolicited content for a campaign may be purged (Block 390 ) from the staging database 168 by the delivery manager 166 . Alternatively, unsolicited content from a completed campaign may be archived in anticipation of the campaign being renewed at a later time (Block 395 ). If the campaign is renewed, then the process may be started again by recreating the purged ad 310 , retagging the ad with meta-data 320 , populating source databases with the ad 330 , and restaging the ad for delivery 340 . Scheduling [0042] Referring now to flowchart 400 of FIG. 4 , the operation of the scheduling function of the UCD system 100 will be discussed in greater detail. More specifically, the relationship between the carrier server 160 , the mobile device 110 , and the operational steps of scheduling unsolicited content for display will now be discussed. The following illustrative embodiment is included to provide clarity for one operational method that may be included within the scope of the present invention. A person of skill in the art will appreciate additional databases and operations that may be included within the UCD system 100 of the present invention, which are intended to be included herein and without limitation. [0043] Referring now more specifically to FIG. 4 and with reference to the diagram of the mobile device illustrated in FIG. 2 , from the start, the operation may begin at Block 410 , where a queue manager 210 on a mobile device 110 may determine if free space is available in the ad queue 220 to cache unsolicited content. If the ad queue 220 is full, i.e., it is determined at Block 410 that there is no free space in the queue, it may be determined at Block 455 whether or not a mobile user 230 may desire to manually purge information to create space in the queue. If it is determined at Block 455 that the user desires to manually purge information, then the queue is purged at Block 457 and the queue is updated at Block 470 . Thereafter, it is again determined at Block 410 whether or not free space exists in the queue. If it is determined at Block 455 that the user does not desire to engage in a manual purge, then the user may wait for some event (Block 460 ) to cause an update to the queue that clears space (Block 470 ) in the ad queue 230 . For example, and without limitation, the playing of an ad on the mobile device 110 may be an event that causes the ad to be removed at Block 460 from the ad queue 220 , thus freeing up space in the ad queue 230 . In another example, and without limitation, recognition of the passing of an expiration date recorded as meta-data on an advert may be an event that triggers the removal of the expired ad at Block 460 from the ad queue 220 , thus freeing up space in the ad queue 220 . [0044] Detection of free space in the ad queue 220 at Block 410 may cause the application of user-generated ad settings (Block 420 ) to govern the download of external unsolicited content to refill the ad queue 220 . For example, and without limitation, at Block 425 , it may be determined whether or not the mobile user 230 has configured ad settings on the mobile device 110 to stop any adverts from being downloaded. If it is determined at Block 425 that the mobile user has configured the ad settings on the mobile device 110 to stop adverts from being downloaded, the ad queue 220 may be purged of any unsolicited content at Block 427 and may remain empty until such time that the user changes ad settings, i.e., updates the ad settings at Block 429 to once again allow downloads. Thereafter, the ad settings are applied at Block 420 . [0045] If, however, it is determined at Block 425 that user-generated ad settings are configured to allow the download of external unsolicited content to fill available space in the ad queue 220 , a download manager 240 may establish a communications link to access the appropriate ad source database at Block 430 , as dictated by the delivery manager 166 on the carrier server 160 that provides mobile network service to the mobile device 110 . For example, the ad source may be a staging database 168 on the carrier server 160 , a campaign database 158 on a campaign server 150 , and/or an advert database 144 on an advertiser host 140 . Using the established communications link, the download manager 240 may download unsolicited content from an ad source (Block 440 ). [0046] At Block 450 , the ad that was downloaded at Block 440 may be scheduled for display. In other words, unsolicited content downloaded by the download manager 240 to the mobile device 110 may be added to the ad queue 220 in keeping with a retrieval algorithm that may be executed by the queue manager 210 to govern the retrieval of unsolicited content from that ad queue 220 . For example, and without limitation, the retrieval algorithm may implement a first-in-first-out (FIFO) queue that presents unsolicited content for display in the order in which that content was downloaded to the mobile device 110 . Alternatively, and without limitation, the retrieval algorithm may implement a priority queue that presents content based first on satisfaction of priority elements (e.g., play duration fit, related content match, geographic location match, browsing history match) and then as FIFO. A person of skill in the art will appreciate additional retrieval algorithms and operations that may be included within the UCD system 100 of the present invention, which are intended to be included herein and without limitation. [0047] Referring now to FIG. 5 , the exemplary graphical user interface 500 illustrates a model interface for configuring advert settings 510 on a mobile device 110 . The graphical user interface 500 may include a plurality of fields which may allow for interaction by the mobile user 230 . [0048] For example, and presented without limitation, the mobile user 230 may active the Size Limits fields 520 to govern the maximum allowable digital file sizes for unsolicited content that may be downloaded to the mobile device 110 via the download manager 240 . The mobile user 230 may use a system interface 250 to access a settings controller 260 to configure advert settings to set a download threshold for daily maximum total download size 523 , a per ad maximum file size 525 , and/or a maximum percentage of available storage 527 that may be enforced by the download manager 240 . [0049] Continuing from the preceding example, the mobile user 230 may activate the Duration Limits fields 530 to govern the maximum allowable play durations for unsolicited content that may be downloaded to the mobile device 110 via the download manager 240 . The mobile user 230 may use a system interface 250 to access a settings controller 260 to configure advert settings to set a download threshold based on daily maximum total play time 533 , a per ad maximum play time 535 , and/or a maximum percentage of available processing time 537 that may be enforced by the download manager 240 . [0050] Continuing from the preceding example, the mobile user 230 may activate the Content Restrictions 540 and/or Screening fields 550 to govern assessment of unsolicited content for suitability to be downloaded to the mobile device 110 via the download manager 240 . The mobile user 230 may use a system interface 250 to access a settings controller 260 to configure advert settings to set a download filter based on user visit history 545 , explicit user approval 547 , and/or user-defined acceptance criteria 559 that may be enforced by the download manager 240 . Display [0051] Referring now to flowchart 600 of FIG. 6 , the operation of the display function of the UCD system 100 will be discussed in greater detail. More specifically, the relationship between the mobile device 110 and the operational steps of displaying unsolicited content will now be discussed. The following illustrative embodiment is included to provide clarity for one operational method that may be included within the scope of the present invention. A person of skill in the art will appreciate additional databases and operations that may be included within the UCD system 100 of the present invention, which are intended to be included herein and without limitation. [0052] From the start, the operation of displaying unsolicited content on the mobile device 110 may begin by monitoring latency at Block 610 . It is thereafter determined at Block 620 whether or not a display event has occurred. A display event (Block 620 ) may be any event that causes a delay, also called latency, in the operation of an application or program on the mobile device 110 . More specifically, a display event (Block 620 ) may result in whitespace, or at least a portion of the electronic visual display 280 of the mobile device 110 being devoid of information to display, commonly referred to as being blank. Examples of display events (Block 620 ) include, without limitation, the mobile device 110 turning on, opening an application or program such as web browsing software, initiating a web page visit, initiating a download, or any other event that results in a delay pending completion of an operation of the mobile device 110 . [0053] If it is determined at Block 620 that a display event has not occurred, then the system may sleep until a trigger event (Block 670 ) causes a resumption of monitoring activity. If the trigger to resume monitoring occurs at Block 670 , then the latency is again monitored at Block 610 . If it is determined at Block 620 that a display event such as latency detection has occurred, then an ad may be retrieved at Block 630 . This may be achieved by the display manager 270 on the mobile device 110 selecting unsolicited content from the ad queue 220 through the queue manager 210 . Thereafter, the ad may be displayed at Block 640 . [0054] The ad that is displayed at block 640 may be displayed in the resulting whitespace on the electronic visual display 280 . The unsolicited content displayed at Block 640 may comprise, for example and without limitation, one or more advertisements. The duration for which the one or more advertisements may be displayed on the electronic visual display 280 will vary according to the length of the delay caused by the display event. The longer the delay, the greater length of time the one or more advertisements may be displayed. If display of an ad (Block 640 ) completes before the period of delay ends, then control of the utilized space on the electronic visual display 280 is yielded at Block 660 to the application that caused the delay. Alternatively, the period of delay ends before the display of an ad (Block 640 ) completes, then at Block 650 the ad display may be terminated, i.e., the display may be interrupted, and normal operation of the display may be resumed. Specifically, the display may be yielded at Block 660 to allow resumption of display of information that is associated with the operation that caused the display event. [0055] In an alternative embodiment, if the delay detected as a display event (Block 620 ) is greater than a threshold amount of time, for instance, ten seconds, a first advertisement (Block 630 ) may be displayed for the first ten seconds (Block 640 ), a second advertisement (Block 630 ) may be displayed for the second ten seconds (Block 640 ), etc., until the delay associated with the display event terminates at Block 650 . [0056] In an alternative embodiment, at Block 620 the length of a display event delay may be estimably determined. Determination of the length of the delay may depend on the nature of the task to be performed causing the delay as well as the capability of the mobile device 110 to expeditiously perform the task, thereby reducing the resulting delay. Once an estimation of the delay has been made, the display manager 270 on a mobile device 110 may select one or more advertisements (Block 630 ) from the unsolicited content stored on the ad queue 220 that require a delay of at least a certain length of time. For example, and without limitation, advertisements requiring a certain length of time to play may include videos, audio clips, and slideshows. This embodiment may permit the content to be displayed in its entirety (Block 640 ) without delaying the execution of the task (Block 650 ) causing the display event delay. [0057] Referring now to FIGS. 7A , 7 B, 7 C and 7 D, the exemplary graphical user interfaces 700 illustrate, without limitation, potential states of a visual display 280 on a mobile device 110 during a display event delay. More specifically, FIG. 7A shows an example of the current state of practice wherein a browser window 710 may present a wait cursor 720 , such as an hourglass graphical icon, to visually inform a mobile user 230 of a display event delay. [0058] Referring now more specifically to FIG. 7B , for example, and presented without limitation, the UCD system 100 may respond to a display event delay by displaying unsolicited content, such as an advertisement 730 , instead of a wait cursor 720 within a latent browser window 710 . [0059] Referring now more specifically to FIG. 7C , in an alternative embodiment, the UCD system 100 may respond to a display event delay by displaying unsolicited content, such as an advertisement 730 , within a newly activated browser window 740 that may be separate from the latent browser window 710 and may be presented in an otherwise unused area of a visual display 280 . [0060] Referring now more specifically to FIG. 7D , in an alternative embodiment, the UCD system 100 may respond to a display event delay by displaying unsolicited content, such as an advertisement 730 , on a visible area of the screen real estate known as wallpaper 750 rather than within a latent browser window 710 . Computing Device [0061] Embodiments of the present invention are described herein in the context of a system of computers, servers, and software. Those of ordinary skill in the art will realize that the following embodiments of the present invention are only illustrative and are not intended to be limiting in any way. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. [0062] A skilled artisan will note that one or more of the aspects of the present invention may be performed on a computing device, including mobile devices. The skilled artisan will also note that a computing device may be understood to be any device having a processor, memory unit, input, and output. This may include, but is not intended to be limited to, cellular phones, smart phones, tablet personal computers (PCs), laptop computers, desktop computers, personal digital assistants (PDAs), etc. FIG. 8 illustrates a model computing device in the form of a computer 810 , which is capable of performing one or more computer-implemented steps in practicing the method aspects of the present invention. Components of the computer 810 may include, but are not limited to, a processing unit 820 , a system memory 830 , and a system bus 821 that couples various system components including the system memory to the processing unit 820 . The system bus 821 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI). [0063] The computer 810 may also include a cryptographic unit 825 . Briefly, the cryptographic unit 825 has a calculation function that may be used to verify digital signatures, calculate hashes, digitally sign hash values, and encrypt or decrypt data. The cryptographic unit 825 may also have a protected memory for storing keys and other secret data. In other embodiments, the functions of the cryptographic unit may be instantiated in software and run via the operating system. [0064] A computer 810 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by a computer 810 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may include computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, FLASH memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer 810 . Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media. [0065] The system memory 830 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 831 and random access memory (RAM) 832 . A basic input/output system 833 (BIOS), containing the basic routines that help to transfer information between elements within computer 810 , such as during start-up, is typically stored in ROM 831 . RAM 832 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 820 . By way of example, and not limitation, FIG. 8 illustrates an operating system (OS) 834 , application programs 835 , other program modules 836 , and program data 837 . [0066] The computer 810 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 8 illustrates a hard disk drive 841 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 851 that reads from or writes to a removable, nonvolatile magnetic disk 852 , and an optical disk drive 855 that reads from or writes to a removable, nonvolatile optical disk 856 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 841 is typically connected to the system bus 821 through a non-removable memory interface such as interface 840 , and magnetic disk drive 851 and optical disk drive 855 are typically connected to the system bus 821 by a removable memory interface, such as interface 850 . [0067] The drives, and their associated computer storage media discussed above and illustrated in FIG. 8 , provide storage of computer readable instructions, data structures, program modules and other data for the computer 810 . In FIG. 8 , for example, hard disk drive 841 is illustrated as storing an OS 844 , application programs 845 , other program modules 846 , and program data 847 . Note that these components can either be the same as or different from OS 834 , application programs 835 , other program modules 836 , and program data 837 . The OS 844 , application programs 845 , other program modules 846 , and program data 847 are given different numbers here to illustrate that, at a minimum, they may be different copies. A user may enter commands and information into the computer 810 through input devices such as a keyboard 862 and cursor control device 861 , commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 820 through a user input interface 860 that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 891 or other type of display device is also connected to the system bus 821 via an interface, such as a graphics controller 890 . In addition to the monitor, computers may also include other peripheral output devices such as speakers 897 and printer 896 , which may be connected through an output peripheral interface 895 . [0068] The computer 810 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 880 . The remote computer 880 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 810 , although only a memory storage device 881 has been illustrated in FIG. 8 . The logical connections depicted in FIG. 8 include a local area network (LAN) 871 and a wide area network (WAN) 873 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. [0069] When used in a LAN networking environment, the computer 810 is connected to the LAN 871 through a network interface or adapter 870 . When used in a WAN networking environment, the computer 810 typically includes a modem 872 or other means for establishing communications over the WAN 873 , such as the Internet. The modem 872 , which may be internal or external, may be connected to the system bus 821 via the user input interface 860 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 810 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 8 illustrates remote application programs 885 as residing on memory device 881 . [0070] The communications connections 870 and 872 allow the device to communicate with other devices. The communications connections 870 and 872 are an example of communication media. The communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. A “modulated data signal” may be a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Computer readable media may include both storage media and communication media. [0071] In accordance with embodiments of the present invention, the components, process steps, and/or data structures may be implemented using various types of operating systems, computing platforms, computer programs, and/or general purpose machines. In addition, after having the benefit of this disclosure, those of ordinary skill in the art will recognize that devices of a less general purpose nature, such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein. [0072] The computer program, according to an embodiment of the present invention, is a computerized system that requires the performance of one or more steps to be performed on or in association with a computerized device, such as, but not limited to, a server, a computer (i.e., desktop computer, laptop computer, netbook, or any machine having a processor), a dumb terminal that provides an interface with a computer or server, a personal digital assistant, mobile communications device, such as an cell phone, smart phone, or other similar device that provides computer or quasi-computer functionality, a mobile reader, such as an electronic document viewer, which provides reader functionality that may be enabled, through either internal components or connecting to an external computer, server, or global communications network (such as the Internet), to take direction from or engage in processes which are then delivered to the mobile reader. It should be readily apparent to those of skill in the art, after reviewing the materials disclosed herein, that other types of devices, individually or in conjunction with an overarching architecture, associated with an internal or external system, may be utilized to provide the “computerized” environment necessary for the at least one process step to be carried out in a machine/system/digital environment. It should be noted that the method aspects of the present invention are preferably computer-implemented methods and, more particularly, at least one step is preferably carried out using a computerized device. [0073] Some of the illustrative aspects of the present invention may be advantageous in solving the problems herein described and other problems not discussed which are discoverable by a skilled artisan. [0074] While the above description contains much specificity, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presented embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments. While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. [0075] Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed.

A system and methods are disclosed whereby a mobile device is provided by one or more servers with unsolicited content. The mobile device stores the unsolicited material e.g. an ordered set of advertisements. A latency delay detector detects an imminent delay for the mobile device that then displays unsolicited items during the latency delay. Display is in screen whitespace and/or wallpaper areas, one item at a time in sequence, each for a predetermined period. Displayed items are purged after display and a user elects whether of not to receive unsolicited material.

FIELD OF THE INVENTION The present invention relates to a system and method for determining position of a system based on reflected signals. BACKGROUND OF THE INVENTION Positioning is a common requirement for many applications such as robot control, fire fighting, and entertainment. Many conventional methods for determining the position of an object are based on external reference points such as those described in U.S. Pat. Nos. 6,707,424 and 6,646,596. The reference points may be active, such as a transmitter or receiver, or passive such as a reflector. The position of the device may be calculated by measuring the distance, delay and/or direction from the reference point to the device. Whilst these methods for determining the position of a device may perform well, the requirement of pre-setting the reference points is not generally convenient and may even be impossible in some situations. Many conventional methods use a transmitter/receiver device in conjunction with at least one active/reflective device situated at a pre-determined position as a point of reference. Frequently, a system is provided which is capable of monitoring its own position relative to the active/reflective device, and this system is attached to the object. The best known of such systems is the GPS system, using satellites. U.S. Pat. Nos. 5,977,958 and 6,054,950 describe methods for measuring time-of-arrival with ultrashort RF pulses (UWB) transmitted from a transmitter to an array of receivers. Despite the differences in technical details, both patents require devices at pre-known positions. U.S. Pat. No. 5,977,958 uses four receivers for its 2D scenario and U.S. Pat. No. 6,054,950 needs at least four receivers or beacons for 3D applications (these receivers or beacons are here termed “explicit references”). There are other similar technologies which are based on angles of arrival of received signals instead of their times of arrival. In such technologies, multiple references are needed. Again, the problem with this type of system is the requirement for references at pre-known positions, which increases the number of devices needed and introduces difficulty in setting up the systems in certain situations or surroundings. Furthermore, such systems require direct line of sight (LOS) between the transmitter and receivers, and the performance decreases sharply in the areas where LOS is not available. Self-positioning methods employed in robotics often use a ring of ultrasonic transducers or laser range finders to obtain a measurement of the respective distance from an object to a surrounding environment in each of a number of directions. A sonar/laser range image may be formed from the distances between the detector and nearby objects. This image may be compared to a known floor plan or trained database in order to find the location of the robot. However, the known floor plan information and trained database may not be available in some environments. Another U.S. Pat. No. 6,112,095 proposes a method of location determination in which a transmitter transmits a radio signal and a receiver device uses an array of antennas to receive the signal both directly and along paths which include reflections (multipath signals). Different locations of the transmitter cause the set of reflected paths to differ, so the received signals constitute a signature of the position. The determination of the location of the transmitter is based on a set of pre-calibrated signal covariance matrices corresponding to possible transmitter locations. However, the uniqueness of the signature is, in principle, not guaranteed and sometimes leads to large errors when the multipath features of one location are similar to those of other locations. Furthermore, the teaching in this citation is intended for outdoor application, and a base-station is required for its implementation. A type of self-positioning device for vehicle use is described in U.S. Pat. No. 6,671,622. Another form of positioning system is able to determine its location without the need of external references, by using a north finder, an inertial measuring system, a velocimeter and an odometer. Such systems are very convenient, but the calculated position may not be sufficiently accurate. In view of the foregoing problems with conventional methods and devices, a need exists for an easily applied self-positioning method which does not require the pre-setting of external reference points. SUMMARY OF THE INVENTION In general terms, the present invention proposes a method and system for determining the position of a device by transmitting/receiving reflection signals to/from surrounding objects, and calculating the distances to the objects and the directions of reflections so as to determine the position of the device itself. An advantage of a preferred embodiment is that there is no need to pre-set external references to obtain the position of the device and the method and system is thereby reference-free and self-positioning. Also, there is no need for training the system to enable its operation nor to include a database or floor plan in the system. The signal used for the distance and direction estimations in a preferred embodiment may be, for example, narrow-band radio frequency (RF), ultra-wide band (UWB), ultrasound or infrared signals. A further advantage of one or more embodiments of the invention is that the position information may be calculated in real-time. According to a first aspect of the present invention there is provided a system comprising: a transmitter for transmitting signals in a number of directions within a range of directions; wherein the transmitter comprises a first rotatable antenna; a receiver for receiving echoes of the signals from any direction in the range; wherein the receiver comprises a second rotatable antenna, the first antenna being mechanically couplable to the second antenna; and a processor for processing the received echoes to derive echo data signals indicative of the distance of the system to one or more reflective surfaces and the direction of the one or more reflective surfaces relative to the system; wherein the processor is arranged to determine the position of the system relative to a starting position from the derived echo data signals indicative of the distance of the system to one or more of the one or more reflective surfaces and the direction of the one or more of the one or more reflective surfaces relative to the system. In a preferred embodiment, the first and/or second antennae comprise one or more mechanically rotatable antennae each having an associated beam pattern gain associated with a beam pattern, the system further comprising one or more electrically rotatable antennae, wherein the one or more electrically rotatable antennae are arranged to be rotatable by varying the gain of the beam pattern(s) of the one or more mechanically rotatable antennae. According to a second aspect of the present invention there is provided a method for determining the position of a system comprising transmitting signals in a number of directions within a range of directions using a transmitter comprising a first rotatable antenna; receiving using a receiver echoes of the signals from any direction in the range; wherein the receiver comprises a second rotatable antenna, the first antenna being mechanically couplable to the second antenna; and processing the received echoes to derive echo data signals indicative of the distance of the system to one or more reflective surfaces and the direction of the one or more reflective surfaces relative to the system; wherein the step of processing comprises determining the position of the system relative to a starting position from the derived echo data signals indicative of the distance of the system to one or more of the one or more reflective surfaces and the direction of the one or more of the one or more reflective surfaces relative to the system. In a preferred embodiment, the receiving step comprises receiving signals using one or more mechanically rotatable antennae each having an associated beam pattern gain associated with a beam pattern, the receiving step further comprising receiving signals using one or more electrically rotatable antennae by varying the gain of the beam pattern(s) of the one or more mechanically rotatable antennae. In a further preferred embodiment, the transmitting step comprises transmitting signals from one or more mechanically rotatable antennae each having an associated beam pattern gain associated with a beam pattern, the transmitting step further comprising transmitting signals using one or more electrically rotatable antennae by varying the gain of the beam pattern(s) of the one or more mechanically rotatable antennae. According to the invention, there is also provided an apparatus for determining its own position within a region having a plurality of planar RF-signal reflective boundaries, the apparatus comprising: a directional RF transceiver; an IR sensor; a rotation mechanism for rotating the RF transceiver and IR sensor though a series of angular positions within an angular range; and a processor arranged to receive (i) first data from the RF transceiver indicative of RF signals received by the RF transceiver at each of the angular positions and (ii) second data indicative of the IR radiation received by the IR sensor, and to perform a positioning algorithm using the first data to estimate the position of the apparatus within the region, the processor further being arranged to modify the positioning algorithm in dependence on the second data. The processor may be arranged to identify a warm object and extract distance information from the second data, the distance information being indicative of the distance from the apparatus to the warm object. The modification may include removing from the first data a component due to reflections from a human body at a distance from the system indicated by the distance information. The positioning algorithm may include: (i) for each angular position, determining whether the first data indicates that the RF transceiver received a reflection from a boundary at that angular position, and (ii) for such angular positions, obtaining distance data indicating the distance of the boundary which caused the reflection, and (iii) using the distance data and the corresponding angular position, to estimate the position of the apparatus within the region. Step (i) of the positioning algorithm may include identifying peaks in the reflected signal which are above a first threshold, and the modification includes reducing the first threshold to a modified threshold in respect of angular positions for which the second data suggests that the received RF signals are partially blocked by a human body. The modified threshold may be obtained based on the respective amplitudes of at least one component of the received signal at a plurality of angular positions for which the second data suggests that the received RF signals are partially blocked by a human body. If the first data indicates that, in respect of a given angular position the received RF signals have an amplitude above the first threshold, the positioning algorithm may not be modified in respect of that angular position. The processor may be arranged to modify the first data to increase the amplitudes of RF signals received by the RF transceiver with increasing echo delay. The RF transceiver may comprise an RF transmitter antenna and a separate RF receiver antenna, at least one of the antennas being a directional antenna. Alternatively, the RF transceiver may comprise a single directional antenna which operates by time division as a transmitter antenna and as a receiving antenna. The RF transceiver may be arranged to emit UWB pulses. According to the invention there is also provided a method for determining the position of an apparatus within a region having a plurality of RF-signal reflective boundaries, the apparatus comprising: a directional RF transceiver; an IR sensor; and a rotation mechanism for rotating the RF transceiver and IR sensor though a series of angular positions within an angular range; the method including performing a positioning algorithm performed on first data indicative of RF signals received by the RF transceiver at each of the angular positions, to estimate the position of the apparatus within the region, wherein the positioning algorithm is modified in dependence on second data indicative of the IR radiation received by the IR sensor, and to perform a positioning algorithm. The method may include identifying a warm object and extracting distance information from the second data, the distance information being indicative of the distance from the apparatus to a warm object. The modification may include removing from the first data a component due to reflections from a human body at a distance from the system indicated by the distance information. The positioning algorithm may include: (i) for each angular position, determining whether the first data indicates that the RF transceiver received a reflection from a boundary at that angular position, and (ii) for such angular positions, obtaining distance data indicating the distance of the boundary which caused the reflection, and (iii) using the distance data and the corresponding angular positions, to estimate the position of the apparatus within the region. Step (i) of the positioning algorithm may include identifying peaks in the reflected signal which are above a first threshold, and the modification includes reducing the first threshold to a modified threshold in respect of angular positions for which the second data suggests that the received RF signals are partially blocked by a human body. The modified threshold may be obtained based on the respective amplitudes of at least one component of the received signal at a plurality of angular positions for which the second data suggests that the received RF signals are partially blocked by a human body. If the first data indicates that, in respect of a given angular position the received RF signals have an amplitude above the first threshold, the positioning algorithm may not be modified in respect of that angular position. The method may include modifying the first data to increase the amplitudes of RF signals received by the RF received with increasing echo delay. The RF transceiver may transmit UWB pulses. According to the invention, there is also provided a method of estimation of a direction of arrival of a signal using a directional antenna, the antenna having an axis which can be moved through a range of angles and having a maximum sensitivity to signals received parallel to said axis, the method including the steps of: (a) obtaining, for each of a plurality of angular positions θ k of the axis of the said antenna, a respective signal strength sample value p(θ k ); (b) using the sample values p(θ k ) and/or the value of a gain function of the directional antenna at the corresponding angle θ k to obtain, for each sample value, a respective weight value w k ; (c) obtaining indication values indicative of an estimate of the direction of arrival from a mathematical function including a respective logarithm value of each sample value, each said logarithm value being weighted in the mathematical function by the respective weight value. The weight values w k may be proportional to the respective sample values. The weight value w k for each respective sample value may be equal to the sample value divided by the sum of the sample values. The weight values may be proportional to the gain function B(θ k −θ M ) of the directional antenna at the corresponding angle θ k , where θ M is the angle for which B is maximal. Step (c) may include: (i) calculating the weighted average angle θ _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ θ k and weighted average sample power in dB d ⁢ p _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ dp ⁡ ( θ k ) ; and (ii) obtaining said indication values â, {circumflex over (b)}, ĉ as given by: [ a ^ b ^ c ^ ] = ( A ′ ⁢ ⁢ T ⁢ A ′ ) - 1 ⁢ A ′ ⁢ ⁢ T ⁢ Y ′ where A ′ = [ θ _ 1 ′ ⁢ ⁢ 2 ⁢ θ _ 1 ′ ⁢ ⁢ 1 θ _ 2 ′ ⁢ ⁢ 2 ⁢ θ _ 2 ′ ⁢ ⁢ 1 … θ _ N ′ ⁢ ⁢ 2 ⁢ θ _ N ′ ⁢ ⁢ 1 ] , ⁢ Y ′ = [ d ⁢ p _ 1 ′ d ⁢ p _ 2 ′ … d ⁢ p _ N ′ ] , said estimated direction being given by θ ^ 0 = - b ^ 2 ⁢ a ^ . According to the invention, there is also provided apparatus for estimating the direction of arrival of a signal, the apparatus comprising: a directional antenna, the antenna having an axis having a maximum sensitivity to signals received parallel to said axis; an actuator for moving the antenna through a range of angles; and a processor arranged to receive from the antenna, for each of a plurality of angular positions θ k of the axis of the said antenna, a respective signal strength sample value P(θ k ); said processor being arranged to: (a) use the sample values P(θ k ) and/or the value of a gain function of the directional antenna at the corresponding angle θ k to obtain, for each sample value, a respective weight value w k ; (b) obtain indication values indicative of an estimate of the direction of arrival from a mathematical function including a respective logarithm value of each sample value, each said logarithm value being weighted in the mathematical function by the respective weight value; and (c) obtain said estimate of the direction of arrival from said indication values. The weight values w k may be proportional to the respective sample values. The weight value w k for each respective sample value may be equal to the sample value divided by the sum of the sample values. The weight values may be proportional to the gain function B(θ k −θ M ) of the directional antenna at the corresponding angle θ k , where θ M is the angle for which B is maximal. The processor may be arranged to obtain the indication values by: (i) calculating the weighted average angle θ _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ θ k and weighted average sample power in dB d ⁢ p _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ dp ⁡ ( θ k ) ; and (ii) obtaining said indication values â, {circumflex over (b)}, ĉ as given by: [ a ^ b ^ c ^ ] = ( A ′ ⁢ ⁢ T ⁢ A ′ ) - 1 ⁢ A ′ ⁢ ⁢ T ⁢ Y ′ where A ′ = [ θ _ 1 ′ ⁢ ⁢ 2 ⁢ θ _ 1 ′ ⁢ ⁢ 1 θ _ 2 ′ ⁢ ⁢ 2 ⁢ θ _ 2 ′ ⁢ ⁢ 1 … θ _ N ′ ⁢ ⁢ 2 ⁢ θ _ N ′ ⁢ ⁢ 1 ] , ⁢ Y ′ = [ d ⁢ p _ 1 ′ d ⁢ p _ 2 ′ … d ⁢ p _ N ′ ] , the processor being arranged to obtain said estimated direction of arrival from the formula θ ^ 0 = - b ^ 2 ⁢ a ^ . According to the invention, there is also provided a positioning system including a direction estimation apparatus as described above, and further including a second processor for controlling the direction estimation apparatus to obtain a direction of arrival estimation for each of at least two received signals, and for using said at least two direction of arrival estimations to obtain an estimate of a location of the positioning system. Features described in relation to one aspect of the invention may also be applicable to the other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Preferred features of the invention will now be described, for the sake of illustration only, with reference to the following Figures in which: FIG. 1 a is a schematic diagram showing a directional antenna and its sectors of rotation according to an embodiment of the invention; FIG. 1 b is a graph of the variation of amplitude and direction of the received reflection from a farthest object in a system including the directional antenna of FIG. 1 a; FIGS. 2 a to 2 h show a series of graphs of amplitude against time at various stages of processing of a received signal from system including the directional antenna of FIG. 1 a; FIG. 3 is a graph showing a Gaussian function of amplitude against direction obtained using a non-linear least-square fitting process and corresponding to a series of samples of processed received signals obtained from a system including the directional antenna of FIG. 1 a; FIG. 4 is a block schematic diagram of a positioning device according to an embodiment of the invention; FIG. 5 is a plan view of a working area showing a positioning device according to an embodiment of the invention at its origin and at a new position; FIG. 6 is an enlarged plan view of a part of FIG. 5 showing the positioning device according to an embodiment of the invention at its origin and at a new position; FIG. 7 is an enlarged plan view of a part of FIG. 5 showing the positioning device according to an embodiment of the invention at its origin and at a new position and showing construction lines for calculating the new position from the origin; FIG. 8 is a schematic view of the system of FIG. 7 illustrating the effects of distance and direction errors; FIG. 9 is a plan view of an irregular positioning area for use with an embodiment of the invention. FIG. 10 illustrates schematically the operation of a system which is an embodiment of the present invention; FIG. 11 illustrates how, in the embodiment of FIG. 10 , there is compensation of the amplitude of a received UWB signal in relation to its echo delay time; FIG. 12 illustrates schematically a situation in which, in the embodiment of FIG. 10 , a human body blocks a plurality of angular sectors; FIG. 13 is a flow diagram of the method performed by the embodiment of FIG. 10 ; FIG. 14 is composed of FIG. 14( a ) and FIG. 14( b ) and illustrates the archetypical problem of fitting-based direction estimation, and the relationship between signal magnitude and direction angle for a directional sensor; FIG. 15 illustrates the noise-free signal power (in dB) and the real received power (in dB, signal+noise) versus direction angles; FIGS. 16 to 18 show the simulated MSE versus SNR performance of an estimation approach which is an embodiment of the present invention, as compared with a prior art technique, for different angle ranges and different sample step-sizes; FIG. 19 shows the experimental UWB reflection signals received by a directional antenna in various directions; and FIG. 20 is a schematic representation of an apparatus which is an embodiment of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Embodiment 1 The method for determining a position of an object such as a robot according to a first embodiment of the invention will be described in connection with FIGS. 1 a to 9 and comprises two basic steps. The first step is a distance measurement and direction determination step and is illustrated with reference to FIGS. 1 a to 3 . The second step is a position determination step and is illustrated with reference to FIGS. 5 to 9 . A positioning system for determining the position of an object according to a first embodiment of the invention is illustrated in FIG. 4 . FIG. 1 a shows a positioning system according to a first embodiment which comprises a transmitter (not shown) coupled to a first rotating antenna 2 which is able to rotate a full 360 degrees in a substantially horizontal plane. The transmitter transmits bursts of signals, for example, ultrawide band (UWB) pulses, which are reflected back to a second rotating antenna 3 . The second rotating antenna 3 is mechanically coupled to the first rotating antenna 2 and the output of the second rotating antenna 3 is electrically coupled to a receiver (not shown). The circle of rotation of the antennae 2 , 3 may be considered to be divided into M sectors. In FIG. 1 a , a farthest object 5 is located in sector m. FIG. 1 b shows the amplitude of the signal reflected back from the farthest object 5 which is in sector m and received at the receiver. In use, the antennae 2 , 3 rotate through 360 degrees and in so doing take M samples. Each sample consists of firing a pulse and processing the reflected signals. Thus there are M sampling angles θ 1 to θ M . Thus, at sampling angle θ m , the directional antennae will cover the range covered by sector m. After each pulse is transmitted, the waveform corresponding to the received signal is recorded for an interval sufficient to recover the main reflection from the farthest object in the working area. In the directional antenna system shown in FIG. 1 a , the received signal from a transmitted pulse may be, for example, as shown in FIG. 2 a and, for each sample, the envelope of the received waveform is detected, as shown in FIG. 2 b. The average value of the waveform in each sector is calculated, as shown in FIG. 2 c . The average value of the waveform in sector m is ξ m . A threshold value, “ν” (where 0<ν) is then set, as shown in FIG. 2 c. The signal is then passed to a slicing stage where it is sliced at a level ν+ξ m . Where the signal is below this slicing level, the output of the stage is zero. Where the input signal exceeds the slicing level, the output of the stage is equal to the input signal level. The output of the stage is shown in FIG. 2 d for sector m. The output of the slicing stage is then passed to a pulse width filtering stage in which the sliced signal is pulse width filtered, that is, a time threshold T is set, as shown in FIG. 2 e . If the non-zero signal in the sliced waveform is less that T in width, the output of this stage is zero. However, if the width of the pulse is greater than T, the output of this stage will be equal to the input signal of this stage, as shown in FIG. 2 f for sector m. The resulting waveforms are stored. After the antennae have completed a full revolution, there will M sample waveforms stored, as shown in FIG. 2 g which illustrates the amplitudes of the stored waveforms over time, the time axis in FIG. 2 g corresponding to the time after each pulse is transmitted, rather than real time. The stored waveforms are then filtered in the space domain in a space domain filtering stage. A space domain threshold “s”, where 0<s, is set for the stored waveforms. If at any time point along the time axis, the signal amplitudes in K neighbouring sectors (which are continual locations along the space axis) are larger than zero, and K>s, the output of the space filtering stage at this point in the K sectors will be equal to their input values. Otherwise, their output is set to zero. FIGS. 2 g and 2 h illustrate this for a case where s is equal to 3. The next stage is to determine the distance and direction of each major reflection. As the distances from major objects to the antennae 2 , 3 will vary from one to another, there is one maximum signal in each sector. The point τ along the time axis at which the maximum signal occurs is the time taken from transmission of the pulse until the signal is received back at the receiver, taking the instant of transmission as zero. The distance d from the object to the positioning device is given by d=cτ/2, where c is the speed of light. FIG. 3 shows a graph of a Gaussian function of amplitude against direction obtained using a non-linear least-square fitting process and corresponding to a series of samples of processed received signals obtained from a system including the directional antenna of FIG. 1 a . To determine the direction of the object from which the transmitted signal is being reflected, the reflected signal corresponding to a group of signals in the space-time domain, the sector containing the maximum signal is selected together with its neighbouring sectors which contain a corresponding signal. P neighbouring sectors are taken which occur before the maximum and P sectors are taken which occur after the maximum, where P should be as large as possible, but 2P+1≦K. The central angle of the sector which contains the maximum is denoted as θ m , as shown in FIG. 1 , and the central angles of the samples being considered are denoted by θ m−p to θ m+p . The direction of the object may be determined by determining the Gaussian function which best fits the distribution of the amplitudes of the reflections from the object. The Gaussian function may be determined using a non-linear least square fitting technique. The nonlinear least-square fitting is a well-known technique, which can be checked on the website, for example, http://mathworld.wolfram.com/NonlinearLeastSquaresFitting.html. FIG. 3 shows an example of fitting the Gaussian function to the amplitudes. In another embodiment, to reduce the fitting complexity, a conventional polynomial fitting technique may be used instead of a non-linear least-square fitting technique. The estimated angular direction of the object with respect to the origin of the sectors corresponds to the peak of the Gaussian function and is denoted by the angle Θ k (where k means the kth reflection), as shown in FIG. 3 . Other methods are also possible for determining the direction. FIG. 4 is a block schematic diagram of a positioning device according to a preferred embodiment of the invention. The device comprises a transmitter 20 which generates pulses which are passed to a directional transmitting antenna 22 . The pulses transmitted from the antenna 22 strike an object 24 and are reflected back to a directional receiving antenna 26 . The signals from the directional receiving antenna 26 are passed to a receiver 28 where they are recovered in a signal reform stage 30 . The output of the signal reform stage 30 is passed to an envelope detection stage 32 . The output of the envelope detection stage 32 is connected to the input of an amplitude threshold stage 34 . In the amplitude threshold stage 34 , the average level of the signal in a particular sector is determined and is added to a predetermined threshold level. The combined level is then compared with the incoming signal from the envelope detection stage 32 . The signals exceeding the combined threshold are then passed to a pulse width filtering stage 36 . In the pulse width filtering stage 36 , the pulses from the amplitude threshold stage 34 are compared with a predetermined pulse width T and pulses narrower than T are rejected. The output of the pulse width filtering stage 36 is passed to a space domain filtering stage 38 where the pulses in a given sector are compared with pulses in neighbouring sectors. The output of the space domain filtering stage 38 depending on whether or not the system is in a first state or a second state, passes to a direction and delay estimation stage 40 if in state 1 or to a delay estimation and direction decision stage 42 if in state 2 . States 1 and 2 are explained in more detail below. The outputs of whichever of the direction and delay estimation stage 40 or the delay estimation and direction decision stage 42 is active is passed to a curve fitting stage 44 . The output of the curve fitting stage 44 is passed to a direction estimation stage 46 . In addition, the output of the direction and delay estimation stage 40 or the delay estimation and direction decision stage 42 , is passed to a distance calculation stage 48 . The estimated direction data and the calculated distance data are passed to an arranging stage 50 where the distance and direction data for each object are grouped in sequence. This data is then passed to a positioning algorithm stage 52 in which the position of the device is calculated. When the system is operating in state 1 , for example, when the antenna system is at the origin, the directions and delays of all major reflections detected in one rotation of the antenna system, are estimated and recorded. The estimated direction will be taken from the output of the space domain filtering stage 38 , that is, from reflections currently obtained. If, however, the system is operating in “state 2 ”, that is, the delay is estimated and recorded but the direction is only estimated, the positioning algorithm stage 52 will select a direction from several known directions as the determined direction. These known directions are directions which have already been estimated at the origin. The decision criterion is preferably denotable by, but is not limited to, the expression: direction=arc k min|{circumflex over (Θ)} k −Θ k | where {circumflex over (Θ)} is the direction estimation result at the current location, and Θ k with various values of k denotes the directions which have already been estimated at origin. When the system is operating in state 2 , the major reflections are estimated but only reflections whose direction has not changed from the previous position are used to calculate the new position. If there are no reflections whose state has not changed, then the system operates in state 1 . Occasionally, there are several maximum values in one non-zero range of the space-time domain, which means that there are several objects in different directions around the device having almost the same distance to the device. In this case, there may be several maximum values found. The corresponding direction of each reflection found is estimated using a non-linear least square fitting technique with the same Gaussian function described above. Using the above procedure, the major reflections around the positioning device may be determined, and the distances and directions of the reflecting object from the positioning device may also be determined. From these, the position of the positioning device may be determined. In a preferred embodiment of the system of FIG. 4 , one or more of the envelope detection stage 32 , the amplitude threshold stage 34 , the pulse width filtering stage 36 , the space domain filtering stage 38 , the direction and delay estimation stage 40 , the delay estimation and direction decision stage 42 , the curve fitting stage 44 , the direction estimation stage 46 , distance calculation stage 48 , the arranging stage 50 and the positioning algorithm stage 52 may be implemented by hardware and/or software in a processor. Two methods of determining the position of the positioning device are proposed, according to preferred embodiments of the invention. A first preferred method may be used where the layout of the positioning area is unknown but it is known to be a convex polygon totally enclosing the positioning area, such as a triangle, a rectangle, or a pentagon, for example. A second preferred method may be used where the layout of the positioning area is unknown and it is not a convex polygon. With regard to the first method, initially the positioning device is located in the centre of the positioning area, which may be regarded as the origin, so that each side of the polygon will cause a reflection to the device. The positioning device may be oriented with a compass. Using the procedures outlined above, distance and/or direction estimation values of the reflections may be obtained from all sides of the polygon. These values are stored then in the device. FIG. 5 shows a pentagonal positioning area 60 and a positioning device 62 located therein currently situated in a position defined as the origin 64 . The various distances of the positioning device 62 from the sides of the positioning area 60 are denoted by l 1 , l 2 , l 3 , l 4 and l 5 . An X-Y system of co-ordinates may be defined with its origin [0,0] at a current location and direction, that is the centre of the positioning area, as shown in FIG. 5 . When the positioning device moves to a new location 66 in the positioning area 60 , as shown in FIG. 5 , the directions of the sides of the positioning area from which the reflections are sent and return and the distances l 1 , l 2 , l 3 , l 4 and l 5 .from the sides of the polygonal positioning area to the positioning device are recalculated. The results are then examined to determine which of the reflections from the sides of the polygon have the same directions as found at the origin. The distance and direction information of two of the reflections may be used to calculate the X and Y values of the new location (X′ and Y′). FIG. 6 shows the origin 64 and the new position 66 of the positioning device 62 together with two sides 68 , 70 of the positioning area 60 , the reflections from which are used to calculate the new position 66 of the positioning device. In FIG. 6 , Θ 1 , is the angle between a line passing through the origin and normal to side 68 , and the x-axis; Θ 2 is angle between line passing through the origin and normal to the side 70 and the x-axis; l 1 ′ is the distance from side 68 to the new position 66 , and l 2 ′ is the distance from side 70 to the new position 66 . As the distances and directions for the two reflections from the sides 68 and 70 are known, Θ 1 , Θ 2 , l 1 , l 1 ′, l 2 , l 2 ′ are known. Hence, the change in l 1 may be denoted as Δl 1 =l 1 ′−l 1 . Similarly, the change in l 2 may be denoted as Δl 2 =l 2 ′−l 2 . Two lines line1 and line2 may be defined as follows where line1 is substantially parallel to side 70 and line2 is substantially parallel to side 68 : line1 :Y =tan(Θ 1 −π/2) X−Δl 1 /sin(Θ 1 −π/2)  (1) line2 :Y =tan(Θ 2 +π/2) X+Δl 2 /sin(Θ 2 +π/2)  (2) These two lines intersect at the new location 66 of the positioning device 62 . The position of the new location 66 is the point of intersection of line1 and line2. Thus, X′ and Y′ are solutions to the above two linear equations. FIG. 7 again shows a section of the positioning area 60 including the origin 64 , the new position 66 and the two sides 68 , 70 of the positioning area which are being used to determine the position of the positioning device 62 . In FIG. 7 , the angle α is the angle made by line1 through the new position 66 to the x axis. The angle β is the angle between a line 72 parallel to side 68 passing through the origin 64 . The angle γ is the angle between the line 72 parallel to side 68 passing through the origin 64 and a line 74 joining the origin 64 to the new position 66 . The angle ψ is the angle between line1 and line 72 . The distance between a line normal to line 68 passing through the new position 62 and the intersection of line1 and line 72 is denoted as the distance a; distance b is the distance from the origin 64 to the intersection 76 of line1 and line 72 ; distance c is the distance between the origin 64 and a line normal to side 68 passing through the new position 66 ; and distance d is the distance between the origin 64 and the new position 62 . The angles and distances may be calculated as follows β=Θ 1 −π/2,  (3) α=π/2−Θ 2 ,  (4) ψ=π−β−α=π−(Θ 2 −Θ 1 ).  (5) a=Δl 1 /tan ψ,  (6) b=Δl 2 /cos ψ,  (7) c=b−a=Δl 2 /cos ψ−Δ l 1 /tan ψ,  (8) γ = arc ⁢ ⁢ tan ⁢ Δ ⁢ ⁢ l 1 c , ( 9 ) d =√{square root over (c 2 +Δl 1 2 )}.  (10) and the co-ordinates of the new position 66 may be calculates as follows: X′=d sin(β−γ) and Y′=d cos(β−γ)  (11) The effects of errors in distance and direction on the accuracy of the positioning of the positioning device, are illustrated in FIG. 8 . In FIG. 8 , four positions 78 , 80 , 82 and 84 show the extreme positions (maximum and minimum) corresponding to the maximum errors in distance and direction. The maximum error for distance measurement is denoted by ε 1 and the maximum error for direction estimation is ε 2 . The real angle between the two reflecting sides 68 , 70 is given by π−(Θ 1 −Θ 2 ). The distance from the maximum error location to the real location may be given by: d e =└(ε 1 +√{square root over ( X′ 2 + Y′ 2 )} tan ε 2 )cos ε 2 ┘/sin(π−(Θ 1 −Θ 2 )−2ε 2 )  (12) d e is associated with the distance from the new position to the origin. If it is assumed that the angle between the two reflecting sides 68 , 70 is ≧π/4, it may be possible to detect a number of reflections at one location, and a couple of reflections which satisfy the requirements may be found easily. Numerically, in a preferred embodiment, the radius of the positioning area may be around 3 m, the maximum error for distance measurement may be around 0.1 m, and the direction error may be around π/180. The maximum error should be smaller than d e ⁡ [ ( 0.1 + 3 · tan ⁡ ( π 180 ) ) ⁢ cos ⁡ ( π 180 ) ] / sin ⁡ [ ( π 4 - 2 ⁢ ɛ 2 ) / 2 ] = 0.279 ⁢ m Preferably, the X and Y errors, that is the distances from the true new position 66 to the extreme error positions, 78 , 80 , 82 and 84 are smaller than d e . Other reflections, which satisfy the angle requirement, that is, where the angle between the two reflecting sides 68 and 70 is ≧π/4, may be processed in a similar manner to calculate X′ and Y′ which are the co-ordinates of the new position 66 . The corresponding values of X′ and Y′ may be averaged for all pairs of these reflections. Note that the direction estimation is only performed at the origin (“state 1 ” in FIG. 4 ). When the positioning device moves to a new position, it is only necessary to determine which side the reflection is from (“state 2 ” in FIG. 4 ) as this may assist in avoiding accumulated errors. When the positioning device moves from the origin to a new position, the reflections from some sides may disappear and this may be due either to the beam being blocked or the angle being such that the reflected beam is not returned to the device. However, other reflections received will guarantee the positioning output. Therefore, the system is capable of overcoming the blocking effect in some situations. FIG. 9 illustrates the alternative method of operating the system in which there is no defined polygon around the positioning area to provide regular reflections. In FIG. 9 , the positioning area 86 is shown together with a series of locations 1 to 7 as the positioning device progresses around the area. Location 1 is the origin 64 . In this situation, it is possible that none of the reflections received at some of the locations will have the same direction as one of reflections at the origin 64 . The position must therefore be determined step-by-step, that is, the current position is determined by the position of the last location and the direction and distance differences between this locations and the current location (for example, location 1 and location 7 in FIG. 9 ). For example, if the device 62 moves from location 1 to location 2 to location 3 to location 4 . . . to location 7 in sequence as shown, the first position (location 1 ) will be fixed as the origin. Distance and direction estimations from all surrounding objects will be determined (state 1 ) and the values recorded. The x and y axes are defined at this point. Based on the location of the start point, it is possible to build a 2D-axis (X-Y) system. As the device moves, distance and direction estimations are made periodically. Note that the state in FIG. 4 is always “state 1 ”. It may be assumed that the sampling locations are sufficiently close together so that most of the reflection parameters (directions and distances) do not change suddenly (mutation) as compared with the last result, that is to say there is no mutation. When the device is moved to a new sampling location, it first scans around to obtain information on all the reflections it receives. From this information, it calculates the increases ΔX and ΔY between the new and last location using the reflections which have the same direction as that in last sampling location. For example, if the co-ordinates of the last position are denoted by [X,Y], then the co-ordinates of the new position are [X′,Y′]=[X+ΔX, Y+ΔY]. The remaining reflections, which have different directions from those detected at the last sampling location, are considered as mutations and are not used at this location. The mutations may be caused by irregular objects or blocking by human beings. Information on all reflections received is recorded for possible use at the next location. The above procedure is performed at each location as the device continues to move. Embodiment 2 Referring firstly to FIG. 10 , an apparatus which is an embodiment of the invention is illustrated schematically. The apparatus includes a RF transmitter antenna 213 (which can be a UWB transmitter) for transmitting signals, and an RF receiver antenna 215 for receiving the signals. At least one, and typically both, of the transmitter antenna 213 and receiver antenna 215 , are directional. If both are directional, the transmitter antenna 213 and receiver antenna 215 are both rotated in sync together around a vertical axis 211 , through a 360 angular range. In this case, the antennas 213 , 215 may be mechanically coupled to each other (e.g. formed as a one-piece unit), with their respective axes aligned. If only one is directional, then that one directional antenna is rotated, and the other may be either rotated or not. Optionally, the apparatus includes a direction finding device (e.g. a compass) for calibrating the angular position of the antennas 213 and/or 215 to some absolute direction. In either case, the transmitter antenna 213 and the receiver antenna 215 can thus be considered here as a single directional RF transceiver, having a single direction (within the angular range) of maximum transmission amplitude/reception sensitivity. The term “directional transceiver” is also used in this document to cover a case in which a single directional antenna plays the role of both the antennas 213 , 215 . The angular range is partitioned into M sectors, each centered on a respective angular position. In each of these sectors the apparatus transmits a signal using the transmitter antenna 213 , and receives a reflected signal using the receiver antenna 215 . Typically, the transmitted signal is a single UWB pulse, and this pulse is transmitted in only one direction within the sector. (Alternatively, the pulse may be transmitted multiple times, and the corresponding received signals averaged). The apparatus further includes a directional IR sensor 217 , which is rotated together with the directional antenna(s) 213 , 215 , so that the IR sensor 217 is always parallel to the transmission/reception direction of the directional antenna(s). (Note that, in principle, the IR sensor could be scanned through the angular range slightly in advance of, or slightly behind, the RF transceiver, provided that the difference between the time that the RF transceiver and the IR sensor 217 are directed at a given sector is less than the typical time taken by a human body to move in or out of that sector). The IR sensor 217 can detect a warm object (i.e. a body having a temperature higher its surroundings, e.g. by a certain temperature detection threshold) such as human body, and determinate the distance of the apparatus from the warm object. The apparatus generally further includes a processor (e.g. one or more micro-processing devices) arranged (e.g. programmed) to find the position of the apparatus within an environment, based on the signals received by the antenna 215 and the IR sensor 217 , as described below. Let us assume that, as illustrated in FIG. 10 , the apparatus is within an environment including walls 205 , 207 , 209 . In this case, when the directional antenna(s) are directed successively towards the walls 205 , 207 , the RF signals will be transmitted from the transmitter antenna 213 , reflected from the wall 205 or 207 , and received by the receiver antenna 215 . At these times the IR sensor 217 does not detect the presence of a human body, and the apparatus accordingly performs a positioning algorithm, in the manner illustrated in FIG. 5 . FIG. 11 ( a ) illustrates the amplitude of the signal picked up by the receiver antenna 215 as a function of time when the antennas 213 , 215 are directed at one of the walls 205 or 207 . It has two peaks: a first peak 241 indicating the received direct-path signal from the transmitter to the receiver, and a second later peak 243 indicating the signal reflected from the wall 205 or 207 . Note that there may be other peaks between these two, due to reflections from other objects (not shown in FIG. 10 ) between the apparatus and the wall, but these peaks are neglected. The peak 243 is the peak received with the maximum delay, indicating that it is the furthest object in the environment. Naturally, the peak 243 is lower according to the distance of the apparatus from the wall 205 , 207 . The received signal strength is compensated for this by multiplying it by a compensation factor which depends upon the distance along the time axis. The compensation factor is the inverse of the distance attenuation (assuming that the attenuation constant for UWB signal propagation in the space is known by pre-investigation). The product of the peak 243 and the compensation factor is illustrated as the peak 245 . After compensation, the reflection signal strength of the peak 245 is independent of the distance between the apparatus and the wall 205 or 207 , and related only to the absorption and blocking from the objects. In dealing with sectors where the IR sensor 217 does not detect a human body, the apparatus employs a threshold ξ c (here referred to as the common threshold). Any received signal with a peak amplitude lower than this threshold is neglected. The threshold ξ c can be determined as ξ c =α( A p −A m )+ A m   (13) where A p is the maximum signal amplitude (after strength compensation) in all sectors and during one complete rotation of the antennas, A m is the average signal amplitude in all sectors and all time (after strength compensation), and α is a constant (0≦α≦1). However, referring again to FIG. 10 , when the directional antenna(s) are directed to the sector m (where m is an integer in the range 1 to M) which contains the normal direction to a wall 207 , the IR sensor 217 detects the presence of a human body 221 . The transmitted RF signal 231 intersects with the human body 221 , and only a small proportion of RF signal 231 propagates through the body 221 , and continues as beam 232 . This beam 232 , once reflected from the wall 209 , again encounters the human body 221 , and only a small proportion of the beam passes through the human body 221 , to propagate as the beam 233 towards the receiver 215 . We now turn to the positioning algorithm performed in the case that the IR sensor 217 has detected a warm object in the sector m. Note that it is possible for the IR sensor 217 to detect the presence of a warm object without that object being a human body 221 . To distinguish a human body from that of other warm objects, the received UWB signal is continuously monitored. A human body absorbs most of UWB signal, and also blocks most of the energy of the UWB reflection from the wall 209 . Thus, if there is a human body 221 in this direction, the received UWB reflection signal 233 will be very weak, and typically smaller than the common case threshold. The embodiment assumes that there is a human body 221 blocking reflections in this direction whenever the IR sensor 217 detects a warm object and the amplitude of the reflection is smaller than the common threshold ξ c . Note that the human blocking may affect several neighbouring sectors, namely the IR sensor may detect this human body blocking in several sequential sectors (shown in FIG. 12 as m−2, m−1, m, m+1, m+2). For all sequential blocked sectors the embodiment uses a reduced threshold ξ b , given by: ξ b =α( A pb −A mb )+ A mb   (14) where A pb is the maximum signal amplitude (after strength compensation) in the sequential sectors affected by this human blocking, and A mb is the average signal amplitude in the sequential blocked sectors (after strength compensation). The reduced threshold is not used in all sectors through which the antennas 213 , 215 rotate, because an unnecessarily low threshold will admit much interference into the system and confuse the reflection detection. When the UWB reflection is blocked by a human body, the reflection from the wall can be very weak, and comparable with the tiny reflection from the human body, although the human body gives very little reflection. In this case, the embodiment may perform IR ranging in this direction to test the distance from the human body to the device. Using this additional information, estimated effects of the UWB reflection from the human body can subtracted from the signal received by the antenna 215 , and so be neglected in UWB distance and angle estimations. Note that processing described above (in the case that the embodiment has determined that a human body is present) might generate a false (pseudo) reflection when there is a human body in a direction sector but no object behind the human body to generate reflections. This does not matter because the positioning algorithm used in Ma Yugang, Sun Xiaobing, Jin Xu and Kanzo Okada, “A system & method for determining position based on reflected signals.” Singapore patent application no. 200403720-6 can ignore it. This is because the false reflection will not correspond to any of the reflections from the objects tested when the apparatus was at the origin point, and hence will be ignored. If the UWB reflection signal is strong (larger than the common threshold ξ c ), the embodiment deduces that warm object is not human body. In this case, the reflection process for angle and distance estimations will be carried out in the same way as in the case that no warm object was detected. Note that since the embodiment uses the UWB signals to make a determination about whether a given warm object is a human body or not, it is able to interpret the significance of the reflected IR signals reliably. It would be much harder to handle the blocking issues of IR ranging and positioning without the assistance of another type of signals, such as UWB signals, because an IR signal hardly passes through a human body. The algorithm explained above for modifying the positioning algorithm described in Ma Yugang, Sun Xiaobing, Jin Xu and Kanzo Okada, “A system & method for determining position based on reflected signals.” Singapore patent application no. 200403720-6 is summarized in FIG. 13 . Starting from an initial state 251 , the apparatus first scans the antennas 213 , 215 , 217 around itself, typically with all three being directed in the same direction at any given time (step 252 ). In step 253 the results are compensated using the compensation factor shown in FIG. 11( b ). In each sector, in step 254 it is determined whether the IR sensor has detected a warm object. If not, the common threshold is used to process the received UWB signal for this sector (step 255 ). If so, the process passes to step 256 in which it is determined whether the received UWB signal is weaker than the common threshold. If not (i.e. the warm object is determined not to be a human body), the process again passes to step 255 . It is to be understood that steps 254 to 256 are performed in turn for each of the sectors. In the case that a plurality of sectors were found for which the determination in step 256 was positive, the embodiment in step 257 uses the UWB reflection amplitudes for those sectors to obtain the reduced threshold ξ b from equation (14). If there are two human bodies at different angular positions (each indicated by a series of sectors in which the IR signal indicates a warm body) the embodiment calculates a different reduced threshold ξ b for each of the bodies. In parallel to step 257 , in step 258 the embodiment uses IR ranging to determine the distance to the warm object identified as a human body. In step 259 , the embodiment uses the range to calculate what UWB reflection is expected to be received from a human body at this distance, and removes that estimated signal from the signal actually received by the antenna 215 , to produce a corrected received signal. In step 260 , the apparatus uses the threshold obtained in step 257 , to process the corrected received signal, to obtain an indication of the reflection from the wall in that sector. Thus, in summary, in steps 255 and 260 , the embodiment identifies the component of the signal received by the antenna 215 which is due to the reflection from a fixed object. Step 255 does this in the case of sectors for which there is no warm object (or a warm object which is identified as non-human), while step 260 does this for sectors where the presence of a human body has been detected. Using the data produced in this way for all the M sectors, in step 261 the embodiment estimates the distances to the walls 205 , 207 , 209 , and the angular positions of the walls 205 , 207 , 209 (i.e. the angular position around the apparatus of lines which are normal to those walls). This can be done using the method of Ma Yugang, Kanzo Okada, Sun Xiaobing and Xu Jin, “Weighted Fitting Method for Direction Estimation, and Apparatus employing the Method” Singapore patent application no. 200500140-9. for example. In step 262 , the embodiment uses the result to obtain an estimated position of the apparatus. This can be done using the method of Ma Yugang, Sun Xiaobing, Jin Xu and Kanzo Okada, “A system & method for determining position based on reflected signals.” Singapore patent application no. 200403720-6, for example. In step 263 , the method terminates. The sequence of steps shown in FIG. 13 may be performed periodically, and/or whenever the apparatus is translated and/or rotated. Embodiment 3 A DOA technique which is an embodiment of the invention will now be described. The construction of the embodiment is illustrated in FIG. 14( a )—although as explained below the operation of the signal receiver is different in detail. Once more, the actual signal received, and on which the embodiment operates, is that shown as “Received signal” in FIG. 15 . The signal which would be received in the absence of noise (i.e. the one shown in FIG. 14( b )) is denoted here by f s , and is stained by the additive white Gaussian noise (AWGN) n(θ). Therefore the received signal f r (θ) can be represented as f r (θ)= f s (θ)+ n (θ) Following U.S. Pat. No. 6,201,496, we first change the non-linear function to a polynomial by a logarithmic transform. Any of a number of transforms can be used within the scope of the invention, but for easy understanding we just adopt “dB” in the following explanation. The actual received signal in dB (i.e. the “received signal in FIG. 2 ), dp r , is represented as dp r (θ)=20 log f r (θ)=20 log [ f s (θ)+ n (θ)] On the other hand the signal power dp s in dB (i.e. the “true function” of FIG. 15 ), should be dp s ⁡ ( θ ) = 20 ⁢ ⁢ log ⁢ ⁢ f s ⁡ ( θ ) = 20 ⁢ ⁢ log ⁡ ( 1 2 ⁢ π ⁢ σ ) - ( θ - θ 0 ) 2 σ 2 ⁢ log ⁡ ( e ) = - log ⁡ ( e ) σ 2 ⁢ ( θ 2 - 2 ⁢ ⁢ θ 0 ⁢ θ + θ 0 2 ) + ⁢ 20 ⁢ log ⁡ ( 1 2 ⁢ π ⁢ σ ) = a ⁢ ⁢ θ 2 + b ⁢ ⁢ θ + c where { a = - log ⁡ ( e ) · 10 σ 2 b = + log ⁡ ( e ) · 2 ⁢ θ 0 σ 2 c = - log ⁡ ( e ) σ 2 ⁢ θ 0 2 + 20 ⁢ ⁢ log ⁡ ( 1 2 ⁢ π ⁢ σ )   As can be seen, dp s is an exact second-order polynomial formula (i.e. the “true function” in FIG. 15 is a parabola). However, because of the additive noise, the received samples actually are realised as the “received signal”. We can use second-order polynomial fitting to estimate the unknown parameters: a, b, c. After that the DOA estimation would be a simple function of these parameters. One conventional polynomial fitting algorithm can be stated as, 1) Calculate θ _ i = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ θ k and d ⁢ p _ i = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ dp ⁡ ( θ k ) , where θ k is the direction angle at which the sample k is received (θ L ≦θ k ≦θ R ), dp(θ k ) is the corresponding power in dB of the received signal. 2) The parameter estimation output is [ a ^ b ^ c ^ ] = ( A T ⁢ A ) - 1 ⁢ A T ⁢ Y where A = [ θ _ 1 2 ⁢ θ _ 1 ⁢ 1 θ _ 2 2 ⁢ θ _ 2 ⁢ 1 … θ _ N 2 ⁢ θ _ N ⁢ 1 ] , ⁢ Y = [ d ⁢ p _ 1 d ⁢ p _ 2 … d ⁢ p _ N ] 3). The estimated signal DOA is θ ^ t = - b ^ 2 ⁢ a ^ We can see, in calculating θ i and d p i in the conventional fitting, all signal samples have the same weight, although these samples have different SNR. By contrast, the embodiment operates as follows. To make use of these signal samples more efficiently, the embodiment adopts different weights in terms of SNR. Since the white noise has constant statistical strength in all directions, the weighting in terms of SNR is approximately equal to the weighting in terms of signal strength, which is simpler in practical operations. Accordingly, the embodiment has the following steps: 1) Derive a weight for each signal sample. The weight may be determined as w i =p r (θ i )/[ p r (θ 1 )+ . . . + p r (θ N )], where p r is the received power (before logarithmic transform). 2) Calculate θ _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ θ k and d ⁢ p _ i ′ = 1 i ⁢ ∑ k = 1 i ⁢ ⁢ w k ⁢ dp ⁡ ( θ k ) . 3) Estimate parameters a, b, c from the following equations: [ a ^ b ^ c ^ ] = ( A ′ T ⁢ A ′ ) - 1 ⁢ A ′ T ⁢ Y ′ where A ′ = [ θ _ ′ 1 2 ⁢ θ _ ′ 1 ⁢ 1 θ _ ′ 2 2 ⁢ θ _ ′ 2 ⁢ 1 … θ _ ′ N 2 ⁢ θ _ ′ N ⁢ 1 ] , ⁢ Y ′ = [ d ⁢ p _ ′ 1 d ⁢ p _ ′ 2 … d ⁢ p _ ′ N ] 4). The output direction estimation is θ ^ t = - b ^ 2 ⁢ a ^ To verify the performance of the direction estimation, the second-order polynomial weighed fitting is simulated and experimentally tested. The simulated results are shown in FIGS. 16 to 18 . The experimental signals are shown in FIG. 19 , and the processing results are given in Table1. FIG. 16 shows the mean squared error (MSE) versus SNR of the direction estimation using the embodiment as compared with the prior art fitting method described above. The MSE here is defined as MSE = E ⁡ (  θ ^ 0 - θ 0 360  2 ) ; the direction angle range is [20, 160]; the direction sample step-size is 10 degrees. We can see the embodiment outperforms the prior art method very much in this case. FIG. 17 . shows the MSE performance of the weighted fitting approach in a smaller directional angle range: [50, 130]. The directional sample step-size is still 10 degrees. We can see that the difference between the embodiment and prior art method becomes smaller if the sample directional range is reduced. This is reasonable because the scan sample range concentrates to the central area, the SNR difference would become small. However, the embodiment is still better than the prior art method. FIG. 18 . shows the MSE in the scan direction angular range: [50, 130] in direction sample step-size of 2 degrees. This means the samples are denser in the same range as in FIG. 17 . We can see the fitting performance is improved for both the embodiment and prior art method. However, the factor of improvement for the embodiment is bigger. FIG. 19 shows experimental results using received UWB signal samples reflected from a 1.2 meter distance wall. We repeated the scanning from 10 degrees to 170 degrees 30 times to obtain the standard deviation (STD). Table 1 shows the experiment performance of this embodiment compared with the prior art method. In each column the top entry is the scanning range, the middle column is the STD entry for the prior art, and the lower entry is the STD for the embodiment. The step size in each case is 10 degrees. We can see the embodiment can achieve 1.564 degrees accuracy, while the prior art one only 3.3 degrees accuracy, as indicated by the values marked with an asterisk in Table. 1. TABLE 1 Angle 10~170 20~160 30~150 40~140 50~130 60~120 70~110 range (degrees) STD for 140.450 25.165 29.165 7.4387 3.3236* 5.7918 135.827 prior art method STD for 1.7490 1.5646* 1.5968 1.6908 1.7493 2.1831 20.0531 embodiment In summary, this embodiment improves the direction estimation accuracy, compared to prior art techniques. If such a method is improved within a positioning system which estimates the position of the signal receiver using incoming signals from two (or more) directions, the positioning accuracy will be higher than in a system employing prior art methods. FIG. 20 shows the overall structure of a positioning system which is a possible embodiment of the invention. It includes an antenna 301 , an actuator 302 for moving the antenna, and a signal receiver 303 . The signal receiver 303 includes a first processor 305 for performing a method as described above to obtain successively a DOA for two signals received from different directions (the system may be able to distinguish them based on their different characteristics, such as different frequencies), and a second processor 307 for controlling the actuator 302 (e.g. to scan respective ranges of angles for each of the signals) and the processing unit 305 . The second processor 307 uses the DOAs obtained by the first processing unit 305 to obtain a position estimate by triangulation, according to conventional methods. Of course, in practice the processors 305 and 307 may be simply different software modules operating on a single physical processor. In an important variation, the weight values ω k are chosen as a function of (e.g. proportional to) the gain function of the antenna at the corresponding angle θ k . For example, if the gain is written as B(θ k −θ M ), where θ M is the angle for which B is maximal (i.e. B(0) is the maximal gain), then the weights may be chosen as ω k =B(θ k −θ M ). Steps (1) to (4) of the embodiment described above may be performed with these weight values. In other embodiments the weight values may be formed using both the corresponding value of the gain function and the corresponding sample value, e.g. as the product of the two. In a further variation, the weighted fitting can be used in peak time estimation by fitting in the time domain of sample values measured at respective instants to a pulse shape. This may, for example, allow a determination of the distances to the objects which transmitted the signals. In a further possible variation, the antenna may receive signals from any direction within a three-dimensional space, so that the DOA of a given signal is defined by two angles, not one. The techniques proposed above may be extended straightforwardly to this situation, which may for example be used for position finding within a three-dimensional space. Various modifications to the embodiment of the present invention described above may be made.

A system and method for determining position of, for example, a robot based on reflected signals comprises a transmitter for transmitting signals in a number of directions within a range of directions and a receiver for receiving echoes of the signals from any direction in the range. The transmitter has a first rotatable antenna and the receiver has a second rotatable antenna which is mechanically couplable to the second antenna. The received echoes are processed by a processor to derive echo data signals indicative of the distance of the system to one or more reflective surfaces and the direction of the reflective surface(s) relative to the system. The processor is arranged to determine the position of the system relative to a starting position from the derived echo data signals indicative of the distance of the system to the reflective surface(s) and the direction of the reflective surface(s) relative to the system.

BACKGROUND OF THE INVENTION The present invention is directed toward novel fluorinated flavone acetic acids (FAA) suitable for use as antitumor agents. The fluorinated FAA compounds are more effective than their unfluorinated counterparts. For example B. Derwinko and L-Y. Yang, "The Activity of flavone acetic acid (NSC 347512) on human colon cancer cells in vitro" Invest. New Drugs, 4:289-93 (1986) disclose that FAA (4-oxo-2-phenyl-4H-1-benzopyran-8-acetic acid) had "relatively poor cytotoxic effects and because the therapeutic range of FAA is so narrow, we conclude that this agent will not be a valuable contribution to the antitumor arsenal at least for colon cancer." Meanwhile, the fluorinated FAA of the present invention has shown curative activity in murine pancreatic carcinoma models and against solid tumors. In particular, they have been shown to exhibit activity against human tumor cell lines and an FAA resistant cell line. INFORMATION DISCLOSURE U.S. Pat. Nos. 4,783,533 and 4,602,034 disclose FAA compounds chemically called (4-oxo-4H-(1)-benzopyran-8-yl)alconic acids their salts and derivatives as well as methods for their preparation and use in the control of tumors. European Patent Application 0278176 discloses various flavone acetic acid analogs described as xanthenone-4-acetic acid. The synthesis and antitumor effect of substituted 4-oxo-4H-1-benzopyrans are described in Eur. J. Med. Chem., 20, 5, p. 393-402 (1985) which was authored by the same inventors of 4,783,533 and 4,602,034. FAA compounds, particularly a diethylaminoethyl ester derivative are discussed in Drugs of the Future, Vol. 12, 2, p. 123-25 (1987). An article in Cancer Research, 48, 5878-82 (Oct. 15, 1988) entitled "Phase I and Clinical Pharmacology Study of Intravenous Flavone Acetic Acid" by Weiss, et al. describes the basic antitumor effects of FAA and results when administered to patients. FAA is reported to have murine tumor activity in animals although no objective tumor response was observed in humans tested. The article also reports the toxicity problems associated with FAA such as acute hypotension and generalized fatigue and asthemia. SUMMARY OF THE INVENTION In one aspect the subject invention is a compound according to Formula I wherein R 1 is CHO, CN, CO 2 M, CO 2 R 3 or CONR 3 R 4 where M is hydrogen or a pharmaceutically acceptable salt such as Li, Na, K, Ca or other acceptable counter-ion for carboxylic acids, R 3 and R 4 are independently hydrogen, C 1 -C 12 alkyl or heterosubstituted alkyl, C 3 -C 10 cycloalkyl or heterosubstituted cycloalkyl, C 6 -C 12 aryl, alkylaryl or are joined to form a C 3 -C 10 cycloalkyl or heterosubstituted cycloalkyl; R 2 is hydrogen, fluorine, methyl, CF 3 , phenyl or substituted phenyl. The fluorinated phenyl ring can be fluorinated at any of the C2 to C6 positions and n is 1 to 5, inclusive. Preferably, R 1 is CO 2 M and R 2 is hydrogen. Typical fluorinated phenyl rings can include 3-fluorophenyl, 2,3,4,5-tetrafluorophenyl, pentafluorophenyl, 3,4-difluorophenyl, 2-fluorophenyl, 4-fluorophenyl, 2,6-difluorophenyl, 3,5-difluorophenyl, 3,4,5-trifluorophenyl, 2,3,5,6-tetrafluorophenyl, 2,3-difluorophenyl, 2,3,4-trifluorophenyl, 2,4,6-trifluorophenyl, 2,5-difluorophenyl or 2,4-difluorophenyl. Preferred compounds include 4-oxo-2-(3-fluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(pentafluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(3,4-difluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(4-fluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2,6-difluorophenyl)-4H-1-benzopyran-8-acetic acid, or 4-oxo-2-(3,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(3,4-difluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(pentafluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(3,4,5-trifluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2,3,5,6-tetrafluorophenyl)-4H- 1-benzopyran-8-acetic acid, 4-oxo-2-(2,3-difluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2,3,4-trifluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2,4,6-trifluorophenyl)-4H-1-benzopyran-8-acetic acid, 4-oxo-2-(2,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid or 4-oxo-2-(2,4-difluorophenyl)-4H-1-benzopyran-8-acetic acid. In another aspect the subject invention is directed toward a pharmaceutical composition comprising an effective amount of a compound according to Formula I described above and a pharmaceutically acceptable carrier. In yet another aspect the subject invention is directed toward an antitumor composition comprising an antitumor effective amount of a compound according to Formula I and a pharmaceutically acceptable carrier. Generally, the fluorinated flavone acetic acid compounds have been discovered to have antitumor activity superior to unflourinated flavone acetic acid compounds. In addition, the fluorinated flavone acetic acids appear to have less toxic effects in animals than the unfluorinated flavone acetic acids. DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to fluorinated FAA compounds represented by the structural formula I. Wherein R 1 is CHO, CN, CO 2 M, CO 2 R 3 or CONR 3 R 4 where M is hydrogen or a pharmaceutically acceptable salt such as Li, Na, K, Ca or other acceptable counter-ion for carboxylic acids, R 3 and R 4 are independently hydrogen, C 1 -C 12 alkyl or heterosubstituted alkyl, C 3 -C 10 cycloalkyl or heterosubstituted cycloalkyl, C 6 -C 12 aryl, alkylaryl or where they are joined to form a C 3 -C 10 cycloalkyl or heterosubstituted cycloalkyl (and are attached to the proximate nitrogen). R 2 is hydrogen, fluorine, methyl, CF 3 , phenyl or substituted phenyl. NR 3 R 4 can be morpholino, piperidino, diethylaminoethyl or dimethylaminoethyl. The fluorinated phenyl ring can be fluorinated at any of the C2 to C6 positions and n is 1 to 5 inclusive. Typical fluorinated phenyl ring structures can include 3-fluorophenyl, 2,3,4,5-tetrafluorophenyl, pentafluorophenyl, 3,4-difluorophenyl, 2-fluorophenyl, 4-fluorophenyl, 2,6-difluorophenyl, 3,5-difluorophenyl, 3,4,5-trifluorophenyl, 2,3,5,6-tetrafluorophenyl, 2,3-difluorophenyl, 2,3,4-trifluorophenyl, 2,4,6-trifluorophenyl, 2,5-difluorophenyl or 2,4-difluorophenyl. Examples of "C 1 -C 12 alkyl" are one to twelve carbon atom chains from methyl to dodecyl and isomeric forms thereof. Examples of "C 3 -C 10 cycloalkyl" are three to ten carbon atoms formed in a ring such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. Examples of "aryl" are six to twelve carbon atom rings which can be substituted with one to three hydroxy, C 1 -C 3 alkyl, trifluoromethyl, fluoro, chloro or bromo group such as phenyl, α-naphthyl, β-naphthyl, m-methylphenyl, p-trifluoromethylphenyl and the like. "Alkylaryl" are seven to twenty-four carbon atoms from a C 1 -C 12 alkyl and a C 6 -C 12 aryl as defined. The "heterosubstituted" forms of the alkyl and cycloalkyl groups are when a carbon in the chain or ring structure is replaced by a heteroatom such as nitrogen, oxygen or sulfur, for example, piperidino and morpholino. The heteroatom can then contain further alkyl, aryl or cycloalkyl groups to complete the valence, for example, dimethylaminoethyl or diethylaminoethyl. "Substituted phenyl" is a phenyl ring having a substituent pending therefrom such as fluorine, chlorine or bromine, hydroxy, or a C 1 -C 4 alkyl group. These compounds can be prepared by one or more methods described below as well as in accordance with the synthesis schemes disclosed in U.S. Pat. Nos. 4,783,533 and 4,602,034, herein incorporated by reference, utilizing the appropriate fluorinated phenyl ring as depicted in Formula I. Generally the fluorinated FAA's of the present invention can be prepared as depicted in Schemes 1 or 2, below. In both Schemes 1 and 2, the various steps are well known in the art. That is, in Scheme 1, step 1 involves a Claisen-condensation of the β-ketoesters. Step 2 is a Simonis-type reaction, acid catalyzed β-ketoester condensation, such as with polyphosphoric acid, or phosphoric acid and phosphorous pentoxide. Step 3 is a radical catalyzed benzylic bromination, such as with N-bromosuccinimide in carbon tetrachloride. Step 4 involves the conversion of bromide to nitrile, a displacement using potassium cyanide and potassium iodide. Finally, Step 5 is the hydrolysis of nitrile to acid using, for example, acetic acid, water and sulfuric acid. In Scheme 2, step 1 is a phenol alkylation which can employ allyl bromide and a base such as potassium carbonate or potassium hydroxide. Step 2 is Claisen rearrangement either by heating or by a Lewis acid treatment. Step 3 is an Allan-Robinson type reaction to prepare flavones such as disclosed in P. K. Jain, et al., Synthesis, pp. 221-22 (1982). Step 4 is an oxidation of the allyl group directly to an acid, for example by using RuCl 3 , NaIO 4 or NaIO 4 , KMnO 4 or ozonolysis followed by ozonide oxidation with hydrogen peroxide. Step 5 is the oxidation of the allyl group to an aldehyde. This can be accomplished by ozonolysis or osmium tetroxide/sodium periodate or with RuCl 3 /NaIO 4 . Finally, Step 6 is the oxidation of the aldehyde to an acid such as by sodium chlorite oxidation or silver oxide oxidation. The fluorinated FAA compounds are more effective as antitumor agents than their unfluorinated analogs as is demonstrated by the in vitro and in vivo experiments. The subject compounds can be effectively administered intraperitoneally, orally, subcutaneously or intravenously. A pharmaceutical composition of this invention contains as its active ingredient the fluorinated FAA compound associated or admixed with an acceptable vehicle or pharmaceutical excipient in suitable form for administration. Unit doses may be sugar-coated pills, tablets, capsules, gellules, phials or bottles. The dosage forms contain between 50 and 1000 mg of active ingredient. As an example, the following compositions can be formulated: Coated pill: active ingredient: 100 mg. Excipients:magnesium stearate, lactose, talcum, starch, alginic acid, hydroxypropylcellulose. Bottle: active ingredient: 1000 mg in freeze-dried form desolved in 20 ml of water for administration by injection. The preferred doses are 1 mg/kg to 300 mg/kg by bolus injection and 0.02 mg/kg/min to 60 mg/kg/min by infusion. Of course, the dose will vary depending upon the age, weight, route of administration and physical condition of the recipient. Pharmacological tests have been carried out on several types of tumor cells in a disk diffusion assay see, generally T. H. Corbett, et al., In Vitro and In Vivo Models of Detection of New Antitumor Drugs, L. J. Hanku, T. Konda and B. J. White, ed., Univ of Tokyo Press, pages 5-14 (1986). The fluorinated FAA (4-oxo-2-(3-fluorophenyl)-4H-1-benzopyran-8-acetic acid) of Example 1 was tested against human H125 lung cells and CX-1 colon cells, mouse cell lines C09, P02 and C38, leukemia L1210 cells and FAA resistant cell lines at various doses. The results are shown in the Table 1, below. A larger number indicates a greater zone of inhibition and thus more antitumor effectiveness. TABLE 1__________________________________________________________________________Dose Leukemia Mouse Human FAATest μg/disk L1210 CO9 PO3 C38 H125 CX-1 Resistant__________________________________________________________________________1 2000 460 600 -- -- -- 320 --2 1000 260 -- 280 150 200 0 2403 500 140 -- 220 240 0 -- 2004 FAA 1000 400-520 -- 600-950 -- 0 0 05 FAA500 0-40 -- 240 400 0 0 0__________________________________________________________________________ Table 1 shows the fluorinated FAA compound (Tests 1-3) to have a dose related anti-tumor activity against leukemia L1210 cells and the various mouse and human cell lines. Especially interesting is the activity demonstrated against the normally FAA resistant cell line at the 1000 and 500 μg/disk dosages and, in particular, against human colon cell line CX-1 at 2000 μg/disk and the human lung line H125 at 1000 μg/disk dosages. Also, it is demonstrated that the FAA (4-oxo-2-phenyl-4H-1-benzopyran-8-acetic acid) controls (Tests 4-5) showed no activity against the human cell lines and the FAA resistant cell line. It is also recognized that while the FAA controls show activity against the mouse cell lines they have been known to not show activity against human cell lines as demonstrated here. In a separate experiment the fluorinated FAA compound of Example 1 was tested for cytotoxicity against murine and human tumor cells in the disk diffusion assay. These results are shown in Table 2. Each disk was treated with 1000 μg per disk of the fluorinated FAA compound. TABLE 2__________________________________________________________________________Mouse FAA Resistant HumanTest L1210 Colon 08 Colon 07 Cell Line Colon 116 Colon CX-1 HCT8 Lung H125__________________________________________________________________________1 440 600 600 350 370 370 -- 3702 270-320 600 240 230 320 -- 280 --__________________________________________________________________________ The results in Table 2 indicate that the subject compound of Example 1 had good activity in vitro against three human tumor colon cell lines (116, CX-1 and HCT8) and a human tumor lung line, H125. The fluorinated FAA compound of Example 1 was also tested in vivo in mice. Escalating dosages were administered to mice having colon adenocarcinoma 38. The maximum dosage tolerated per IV injection was between 150 to 220 mg/kg. The first dosage of about 100 mg/kg produced a stupor but subsequent dosages escalated to 150 mg/kg were well tolerated. The fluorinated FAA (tests 1 and 2) was obviously active against Colon 38 as shown in Table 3, below, versus a Control which was tumored mice receiving no drug treatment. TABLE 3__________________________________________________________________________ Dosage Drug Median Tumor Tumor FreeTest # Mice mg/kg Days Injected Deaths mg/on day 31 T/C in % at day 60__________________________________________________________________________1 5 220 3 3 44 3 12 5 150 6, 9, 12, 15 0 448 32 2Control6 0 -- 0 1383 -- 0__________________________________________________________________________ Additionally, BDF 1 mice were treated for early stage pancreatic ductal adenocarcinoma 03. These tests are shown in Tables 4 and 5 below. TABLE 4______________________________________ Dose Total Drug Tumor FreeTest Drug mg/kg/injection Dosage Deaths on Day 26______________________________________1 FAA 235 205 5/5 Toxic2 FAA 162 486 1/5 4/53 FAA 112 336 0/5 1/54 Ex. 1* 155 465 4/6 2/65 Ex. 1* 107 321 0/6 3/66 Ex. 1* 74 222 0/5 0/57 Control 0 0 0/6 0/6______________________________________ *Compound of Example 1, 4oxo-2-(3-fluorophenyl)-4H-1-benzopyran-8- acetic acid. The data in Table 4 indicates that at the lower dosage level of 321 mg/kg the fluorinated FAA was more potent as an antitumor drug than FAA. TABLE 5______________________________________ Dose Total Drug Tumor FreeTest Drug mg/kg/injection Dosage Deaths on Day 26______________________________________1 Ex. 4* 80 on day 3 330 0/5 3/5 100 on day 5 150 on day 72 Ex. 5** 90 on day 3 360 0/5 4/5 110 on day 5 160 on day 7______________________________________ *Compound of Example 4, 4oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8- acetic acid. **Compound of Example 5, 4oxo-2-(4-fluorophenyl)-4H-1-benzopyran-8- acetic acid. Both drugs used in tests 1 and 2 were effective in the treatment of tumors. Interesting was that these drugs did not cause a stupor even at the higher dosage injections. The mice were repeatedly checked up to 3 hours post injection and no stupor was observed. This is in sharp contrast to FAA and even the Example 1 compound which showed modest stupor in mice after higher dose injections of about 180 mg/kg. For example, the fluorinated FAA of Example 1 produced shallow rapid breathing and modest stupor. The dosages were escalated to produce evident toxicity. At about 180 mg/kg one out of five mice tested were killed. The compound showed activity against tumors as three out of five mice were tumor free on the 35th day. The remaining mouse had a very small mass of 32 mg which may not have been viable tumor cells. Meanwhile, in the control group where no treatment was given all six mice exhibited a median tumor of 1852 grams on the 28th day and were not tumor free on the 35th day. EXAMPLE 1 Preparation of 4-oxo-2-(3-fluorophenyl)-4H-1-benzopyran-8-acetic acid. Step 1 A mixture of 60 g of o-cresol and 153 g of ethyl 3-fluorobenzoylacetate was added over 30 minutes to a mechanically stirred solution of 750 g of polyphosphoric acid. The resulting mixture was stirred at 75° C. for 4 hours, then cooled and poured into 8 liters of ice water and subsequently extracted with three four liter portions of ethyl acetate. The solvent in the organic fractions was concentrated in vacuo and the residue chromatographed over 7 kg of silica gel eluting with 20% acetone in hexane to give 23 g of title product which was then recrystallized from ethyl acetate to give 16 g of pure 8-methyl-2-(3-fluorophenyl)-4H-benzopyran-4-one. TLC Rf 0.3 in 10% acetone in hexane; NMR (CDCl 3 ) δ 2.6 (s, 3H), 6.8 (s, 1H), 8.04-8.08 (m, 1H). Steps 2 and 3 A mixture of 14.3 g of 8-methyl-2-(3-fluorophenyl)-4H-benzopyran-4-one, 17.2 g of N-bromosuccinimide and 3.5 g of azobisisobutyronitrile (AIBN) in 700 ml of carbon tetrachloride was refluxed for 6.5 hours, cooled to room temperature and stirred overnight and then diluted with 100 ml of water. The solvents were removed in vacuo and the residue recrystallized from hot ethyl acetate to give 16.5 g of 8-bromomethyl-2-(3-fluorophenyl)-4H-benzopyran-4-one which was used without further purification. A suspension of 11.2 g of the above prepared 8-bromomethyl-2-(3-fluorophenyl)-4H-benzopyran-4-one, 3.2 g of potassium cyanide, 5.7 g of potassium iodide and 1.3 g of aliquot 336 (tricaprylylmethylammonium chloride) in 45 ml of water and 485 ml of toluene was stirred for 25.5 hours at 73° C., cooled, diluted with water and extracted with methylene chloride. The solvents in the organic layer were concentrated in vacuo and the resulting residue chromatographed over silica gel with 3-5% acetone in a 1:1 mixture of methylene chloride and hexane to give 4.6 g of 8-cyanomethyl-2-(3-fluorophenyl)-4H-benzopyran-4-one. IR 1643 cm -1 ; NMR (CDCl 3 ): δ 4.06 (2, 1H), 6.8 (s, 1H), 7.0-7.85 (m, 6H), 8.2 (m, 1H). Step 4 A mixture of 4.6 g of 8-cyanomethyl-2-(3-fluorophenyl)-4H-benzopyran-4-one; 18 ml of glacial acetic acid and 18 ml of sulfuric acid in 418 ml of water was stirred 12 hours at room temperature and diluted with 200 ml of water. The resulting suspension was filtered and the solids washed with water, then dissolved in 170 ml of 5% aqueous sodium bicarbonate, filtered to removed insoluble solids and acidified by addition of 11 ml of concentrated sulfuric acid. The resulting precipitate was filtered and the solids washed with water and dried to give 4.4 g of 4-oxo-2-(3-fluorophenyl)-4H-1-benzopyran-8-acetic acid as a white solid: IR 1645 and 1700 cm -1 ; m.p. 208°-211° C. EXAMPLE 2 Preparation of 4-oxo-2-(3,4-difluorophenyl)-4H-1-benzopyran-8-acetic acid. Step 1 A suspension of 6.2 g of potassium hydroxide, 10 g of 2-hydroxyacetophenone and 17.8 g of allyl bromide in 550 ml of acetone was refluxed for 16 hours, cooled and filtered. The solids were extracted with three 250 ml portions of chloroform and the combined acetone filtrate and chloroform extracts concentrated to give a residue which was then heated at 165° C. for 18 hours, cooled, diluted with 250 ml of hexane and filtered. The resulting filtrate was concentrated in vacuo to give 10.02 g of 3'-allyl-2'-hydroxyacetophenone as a liquid: TLC Rf 0.70 in 3:1 toluene-methyl isobutylketone; C-13 NMR (CDCl 3 ): δ26.72, 33.41, 116.0, 118.44, 119.21, 128.82, 129.34, 136.10, 136.44, 160.40, 204.75; 1 H-NMR (CDCl 3 ): δ2.60 (s, 3H), 3.40 (d, J=6.4 Hz, 2H); 5.05 (d, J=1.4 Hz, 1H), 5.08-5.11 (m, 1H), 5.92-6.06 (m, 1H), 6.82 (t, J=7.6 Hz, 1H), 7.33 (d, J=6.7 Hz, 1H), 7.59 (d, J=6.7 Hz, 1H), 12.62 (s, 1H). Step 2 A mixture of 1.7 g (9.4 mmol) of 3'-allyl-2'-hydroxyacetophenone, 2.0 g (11 mmol) of 3,4-difluorobenzoyl chloride, 1.6 g (4.7 mmol) of tetra-n-butylammonium bisulfate, 60 ml of 10% aqueous potassium hydroxide and 60 ml of benzene was heated at 60° C. for 4 hours, cooled and the phases separated. The organic phase was washed with three 60 ml portions of water, treated with 5.6 g (28 mmol) of p-toluenesulfonic acid monohydrate and an additional 60 ml of benzene and refluxed for 3 hours, using a Dean-Stark trap to remove the water in the reaction. The resulting mixture was washed with 150 ml of 8% aqueous sodium bicarbonate and then with three 60 ml portions of water. The organic phase was then concentrated in vacuo; treated with 25 ml of methanol and cooled to -20° C. After four hours the resulting solid was filtered, washed with three 5 ml portions of methanol and dried to give 1.62 g (56%) of 8-allyl-2-(3,4-difluorophenyl)-4H-benzopyran-4-one as a solid: m.p. 127°-130° C.; TLC Rf 0.48 in 3:1 toluene-methyl isobutyl ketone. Step 3 A mixture of 1.0 g (3.4 mmol) of 8-allyl-2-(3,4-difluorophenyl)-4H-benzopyran-4-one, 3.6 g (17 mmol) of sodium periodate, 7 ml of carbontetrachloride, 7 ml of acetonitrile and 15 ml of water was treated with 0.14 g (0.66 mmol) of rothenium (III) chloride, stirred for 4 hours and then diluted with 50 ml of methylene chloride. The phases were separated and the aqueous phase extracted with three 50 ml portions of methylene chloride. The combined organic phases were concentrated in vacuo, treated with 500 ml of diethyl ether and filtered. The resulting solids were extracted with three 100 ml portions of 8% aqueous sodium bicarbonate solution and the aqueous extract washed with three 100 ml portion of chloroform. The aqueous phase was treated with concentrated hydrochloric acid (to pH 1) and then extracted with three 100 ml portions of chloroform. The final chloroform extract was evaporated in vacuo to give 0.131 g (12%) of 4-oxo-2-(3,4-difluorophenyl)4H-1-benzopyran-8-acetic acid as a solid: m.p. 145°- 147° C.; TLC Rf 0.26 in 64:25:10:1 toluene-methylisobutylketone-methanol-acetic acid. EXAMPLE 3 Preparation of 4-oxo-2-(pentafluorophenyl)-4H-1-benzopyran-8-acetic acid Step 1 A mixture of 19 g (mmol) 3'-allyl-2'-hydroxyacetophenone, 25 g (110 mmol) pentafluorobenzoyl chloride, 36 g (110 mmol) tetra-n-butylammonium bisulfate, 750 ml 10% aqueous KOH, and 750 ml benzene was heated at 80° C. for 6 hours, cooled and the phases separated. The organic phase was concentrated in vacuo and flash chromatographed over 100 g silica gel with success, 2 liter portions of hexane, diethyl ether and CHCl 3 . The diethyl ether eluate was evaporated in vacuo. The residue was dissolved in 250 ml methanol and cooled at -20° C. for 24 hours. The mixture was filtered and yielded 8-allyl-2-(pentafluorophenyl)-4H-benzopyran-4-one as 10.141 g (27%) solid: TLC R f 0.35 in 49:25:25:1 CHCl 3 :toluene:hexane:methanol. Step 2 A mixture of 2.0 g (5.7 mmol) 8-allyl-2-pentafluorophenyl)-4H-benzopyran-4-one, 5.8 g (27 mmol) NaIO 4 , 0.091 g (0.36 mmol) RuCl 3 .-H 2 O, 50 ml CH 3 CN, 50 ml CCl 4 and 100 ml H 2 O was stirred at room temperature. After 5 hours, 300 ml CHCl 3 was added to the mixture and the phases were separated. The aqueous phase was extracted with 500 ml 9:1 CHCl 3 :CH 3 OH and 400 ml H 2 O was added to the aqueous phase. This aqueous phase was extracted with two 500 ml portions 9:1 CHCl 3 :CH 3 OH. The combined organic extracts were concentrated in vacuo to approximately 25 m and added to 1 liter of hexane. The mixture was filtered in vacuo and the filtered solids were redissolved and precipitated in hexane two more times. This yielded 0.259 g (12%) of 4-oxo-2-(pentafluorophenyl)-4H-1-benzopyran-8-acetic acid as a solid: m.p. 156°-160° C.; TLC R f 0.23 in 24:25:10:1 toluene:methylisobutylketone:methanol:acetic acid. EXAMPLE 4 Preparation of 4-oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8-acetic acid Step 1 A mixture of 0.528 g (3 mmol) of 3'-allyl-2'-hydroxyacetophenone, 0.57 g (3.6 mmol) of 2-fluorobenzoyl chloride, 0.509 g (1.5 mmol) of tetra-n-butylammonium bisulfate, 20 ml of 10% aqueous potassium hydroxide and 20 ml of benzene was heated at 80° C. for 3 hours. The layers were separated and the benzene layer washed thoroughly with water (3×20 ml) and the water removed from the benzene layer by azeotropic distillation. The resulting residue was treated with 1.7 g (9 mmol) of p-toluenesulphonic acid and benzene (25 ml) and heated for two hours with azeotropic removal of water. The benzene solution was washed with 8% aqueous sodium bicarbonate (50 ml) and the solvent evaporated in vacuo. The resulting residue was recrystallized from ethyl acetate to give 0.49 g (58%) of 8-allyl-2-(2-fluorophenyl)-4H-benzopyran-4-one as white solid: M.P. 78°-81° C.; TLC R.sub. f 0.40 in 10:1 hexane-ethylacetate. Step 2 A mixture of 1.4 g (5 mmol) of 8-allyl-2-(2-fluorophenyl)-4H-benzopyran-4-one, 4.4 g (20.5 mmol) of sodium periodate, 50 ml of carbon tetrachloride, 50 ml of acetonitrile, and 75 ml of water was treated with 0.025 g (2.2% mol) of ruthenium trichloride hydrate. The entire mixture was stirred vigorously for 2 hours at room temperature and the phases were separated. The upper aqueous phase was extracted with three 50 ml portions of methylene chloride. The combined organic extracts were washed with 30 ml of 10% aqueous sodium bisulfite solution and then extracted with three 50 ml portions of 10% aqueous sodium hydroxide solution. The aqueous phase was treated with concentrated hydrochloride acid (to pH 1) and then extracted with three 100 ml portions of ethyl acetate. The extracts were dried over magnesium sulfate and concentrated in vacuo to give yellow solid which was recrystallized in methanol to give 0.274 g (18%) of 4-oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8-acetic acid as a white solid: M.P. 179°-181° C.; TLC R f 0.29 in 40:40:1 hexane-ethylacetate-acetic acid. EXAMPLE 5 Preparation of 4-oxo-2-(4-fluorophenyl)-4H-1-benzopyran-8-acetic acid Step 1 The same procedure as used in Example 4 was used to prepare this compound. Starting from a 3 mmol scale, 0.375 g (45%) of 8-allyl-2-(4-fluorophenyl)-4H-benzopyran-4-one was obtained as a white solid: M.P. 98°-100° C.; TLC R f 0.38 in 10:1 hexane-ethyl acetate. Step 2 A similar procedure as used in Example 4 was used employing 6 equivalents of sodium periodate and 3.3 mol % of ruthenium trichloride for 1.5 hours at room temperature to give 0.075 g (25%) of 4-oxo-2-(4-fluorophenyl)-4H-1-benzopyran-8-acetic acid as white crystals: M.P. 207°210° C. EXAMPLE 6 Preparation of 4-oxo-2-(2',3',4',5'-tetrafluorophenyl)-4H-1-benzopyran-8-acetic acid. Step 1 A mixture of 25 g (130 mmol) 2,3,4,5-tetrafluorobenzoic acid, 0.5 ml DMF, 200 ml CH 2 Cl 2 and 17 ml (192 mmol) oxalyl chloride was stirred at room temperature for 21 hours. The mixture was filtered and evaporated in vacuo. The concentrate was extracted with 3×300 ml hexane. The extract was filtered via gravity through a coarse pore sintered glass funnel. This filtrate was evaporated in vacuo to yield 22 g (76%) of 2,3,4,5-tetrafluorobenzoylchloride as a colorless liquid. 1 H-NMR(CDCl 3 ) δ281-289 (m, 1H); 13 C-NMR(CDCl 3 ): δ114.882 (d, J=21.7 Hz), 141.300 (d, J=270.0 Hz), 144.763 (d, J=279 Hz), 146.303 (d, J=241 Hz), 147.595 (d, J=279 Hz), 160.593. Step 2 A mixture of 19.3 g (110 mmol) 3'-allyl-2'-hydroxyacetophenoxy 22 g (110 mmol) 2,3,4,5-tetrafluorobenzoyl chloride, 38.4 g (110 mmol) tetra-n-butylammonium bisulfate, 750 ml 10% aqueous KOH and 750 ml benzene was heated at 80° C. for 6 hours, cooled and the phases were separated. The organic phase was concentrated in vacuo and flash chromatographed over 100 g silica gel with successive 2 l portions of hexane and 9:1 CHCl 3 :CH 3 OH. The CHCl 3 :CH 3 OH eluate was concentrated in vacuo, treated with 500 ml hot CH 3 OH and cooled to -20° C. After 24 hours, the resulting solid was filtered, washed with three 25 ml portions of cold methanol and dried to give 5.35 g of 8-allyl-2-(2,3,4,5-tetrafluorophenyl)-4H-benzopyran-4-one as a solid: TLC R f 0.37 in 49:25:25:1 CHCl 3 :toluene:hexane: CH 3 OH; 1 H-NMR (DMSO) δ3.44 (d, J=6.5 Hz, 2H), 5.06 (s, 1H), 5.09-5.10 (m, 1H), 5.92-6.09 (m, 1H), 6.94 (s, 1H), 7.00 (t, J=9.6 Hz, 1H), 7.31 (d, J=7.4 Hz, 1H), 7.55 (d, J=7.8 Hz, 1H), 7.82-7.88 (m, 1H); 13 (-NMR (DMSO) δ35.376, 107.823 (d, J=18.9 Hz), 112.735, 117.685, 120.791, 121.10, 121.686, 129.056, 130.408, 135.025, 138.032, 141.300 (d, J=270 Hz), 144.763 (d, J=279 Hz), 146.303 (d=241 Hz), 147.595 (d, J=279 Hz), 154.957, 164.706, 176.488. Step 3 A mixture of 2.0 g (6.0 mmol) of 8-allyl-2-(2,3,4,5-tetrafluorophenyl)-4H-benzopyran-4-one, 6.4 g (30 mmol) NaIO 4 , 0.100 (0.40 mmol) RuCl 3 .H 2 O, 50 ml CCl 4 , 50 ml CH 3 CH and 100 ml H 2 O was stirred at room temperature. After 5 hours, 300 ml CHCl 3 was added and the phases separated. The aqueous phase was extracted with 500 ml 9:1 CHCl 3 :CH 3 OH. An additional 400 ml H 2 O was added to the aqueous phase which was then extracted with two 500 ml portions of 9:1 CNCl 3 :CH 3 OH. The combined organic extracts were concentrated in vacuo to approximately 25 ml and added to 1 l of hexane. The mixture was filtered in vacuo and the filtered solids were redissolved and precipitated in hexane two more times. This yielded 0.345 g of 4-oxo-2-(2,3,4,5-tetrafluorophenyl-4 H-1-benzopyran-8-acetic acid as a solid: M.P. 154°-159° C. EXAMPLE 7 Preparation of 4-oxo-2-(2,6-difluorophenyl)-1H-1-benzopyran-8-acetic acid Step 1 The same procedure as used in Example 4 was used to give 8-allyl-2-(2,6-difluorophenyl)-4H-benzopyran-4-one as pale yellow crystals in 35% yield: M.P. 84°-86° C.; TLC R f 0.45 in 10:1 hexane-ethyl acetate. Step 2 A similar procedure as used to prepare 4-oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8-acetic acid in Example 4 was used, employing 6 equivalents of sodium periodate and 3.3 mol % of ruthenium trichloride for 1.5 hours at 0° C. to give 4-oxo-2-(2,6-difluorophenyl)-4H-1-benzopyran-8-acetic acid in 35% yield as white crystals: M.P. 178°-180° C.; TLC R f 0.27 in 40:40:1 hexane-ethyl acetate-acetic acid. EXAMPLE 8 Preparation of 4-oxo-2-(3,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid Step 1 The same procedure as used in Example 4 was used to prepare 8-allyl-2-(3,5-difluorophenyl)-4H-1-benzopyran-4-one in 38% yield as white crystals: M.P. 152°-155° C.; TLC R f 0.35 in 10:1 hexane-ethyl acetate. Step 2 A similar procedure as used to prepare 4-oxo-2-(2-fluorophenyl)-4H-1-benzopyran-8-acetic acid in Example 4 was used, employing 5 equivalents of sodium periodate and 3.3 mol % of ruthenium trichloride for 1.5 hours at room temperature to give 4-oxo-2-(3,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid as white crystals in 16% yield: M.P. 221°-223° C.; TLC R f 0.29 in 40:40:1 hexane-ethyl acetate-acetic acid. EXAMPLE 9 Preparation of 4-oxo-2-(2,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid To a 500 ml flask was added 20 g (165.3 mmol) allylbromide, 20 g (147 mmol) 2-hydroxyacetophenone, 10 g (178.6 mmol) potassium hydroxide and 250 ml acetone. The mixture was stirred and refluxed for 6 hours. The resulting suspension was filtered, and the filtered solid was washed with ethyl acetate (3×100 ml). The filtrate was evaporated in vacuum to give 27.8 g of an allyl ether as a yellow oil. The crude allyl ether was directly heated neat at 220° C. (oven temperature) for 72 hours under N 2 . The reaction product was collected as a pale yellow oil after vacuum distillation (b.p. 105°˜115° C. at 1 mm) to give 24.4 g (94%) of 3-allyl-2-hydroxyacetophenone. To a 100 ml flask fitted with a calcium chloride drying tube was added 5.5 g (31.2 mmol) of 3-allyl-2-hydroxyacetophenone, 5 g (28.4 mmol) of 2,5-difluorobenzoyl chloride, 5 ml of Et 3 N and 10 ml of pyridine. The temperature of the reaction mixture rose spontaneously. The stirred reaction mixture was heated at 70° C. for one hour. The mixture was cooled and poured into 200 ml of 5% HCl with stirring and extracted with EtOAc (3×50 ml). The combined organic layers were washed with H 2 O and dried over MgSO 4 , and then concentrated to give 9.5 g of 2,5-difluoro-flavone acetic acid as a yellow crude oil. The crude product was directly used in next step without further purification. To a one liter round-bottom flask containing 200 ml of CH 3 CN, 200 ml of CCl 4 and 300 ml of water was added 9.4 g (28.4 mmol) of crude 2,5-difluoro-flavone acetic acid, 31.1 g (5.12 eq) of NalO 4 and 290 mg (0.044 eq) of RuCl 3 .H 2 O. After stirring vigorously for 2.5 hours at room temperature, the organic layer was separated, and the aqueous layer was extracted with CH 2 Cl 2 (100 ml×3). The combined organic layers were washed with 10% aq Na 2 SO 3 solution (50 ml) and brine, dried over MgSO 4 , and concentrated to give 10.5 g of crude acid product. To a warmed 15 ml pyridine solution of 10.5 g (28.4 mmol) of the crude acid product was added 4.97 g (80%, 2.5 eq) of pulverized KOH. The resulting mixture was heated to 70° C. and stirred for 1 hour during which time much precipitate formed. The mixture was cooled and acidified with 250 ml of 5% aqueous HCl solution. The crude diketone formed was separated as yellow precipitate which was collected on a filter and dried to give 5.2 g (54%) of crude product. To a solution of 5.2 g of the crude diketone in 50 ml of glacial acetic acid was added 2 ml of concentrated H 2 SO 4 with stirring. The resulting mixture was heated to 100° C. for 1 hour and then poured onto 300 g ice with vigorous stirring. The crude final product was collected on a filter, washed with H 2 O (300 ml) and recrystallized in MeOH to give 1.58 g of 4-oxo-2-(2,5-difluorophenyl)-4H-1-benzopyran-8-acetic acid as white crystals with an overall yield of 17% from 2,5-difluorobenzoyl-chloride. M.P. 223°±1° C. ##STR1##

A fluorinated flavone acetic acid suitable for use as an antitumor agent. Pharmaceutical compositions comprising the fluorinated flavone acetic acid and a pharmaceutically acceptable carrier. An antitumor composition comprising an antitumor effective amount of a fluorinated flavone acetic acid in a pharmaceutically acceptable carrier.

[0001] This is a national stage of PCT/DK09/000072 filed on 26 Mar. 2009 and published in English, which has a priority of European Patent Appln. No. 08388012.0 filed 26 Mar. 2008, hereby incorporated by reference. FIELD OF THE INVENTION [0002] The present invention relates to exercise equipment or training devices allowing the user to perform a specific physical activity aimed to improve for example strength, stamina or agility of the user. The training device may be designed to train certain parts of the body or to improve the general fitness of the user. Training devices range from simple lifting weights, exercise balls and the like to more complex treadmills, exercise bikes and the like. BACKGROUND OF THE INVENTION [0003] Individuals recovering from a surgery or injury may speed up their recovery by the use of training devices. Such individuals typically need small and light training devices suitable for use in hospital or home environments. Training devices suitable for physical therapy should preferably be flexible, adjustable and work in a controlled manner to be usable for different patient groups needing different training. Depending on the body part in need of training a different training program may be required. Additionally, some patients are in need of frequent rest periods while others may train for a longer time period. [0004] Most training devices provide a rather monotonous training without any intellectual stimulation and tend to bore the user within a few minutes of activity. Additionally, most exercise systems are quite heavy and therefore cannot be moved over a very far distance and provide very little portability. SUMMARY OF THE INVENTION [0005] It is an object according to the invention to provide a device and a method for indoor physical activity, which gives the user increased intellectual stimulation and thereby motivation during the training exercise. It is a further object of the invention to provide a system, which is both modular and flexible to allow it to be transported and assembled in any location. [0006] The above object together with numerous other objects, advantages and features which will be evident from the below detailed description of the presently preferred embodiments of the invention according to a first aspect of the present invention are according to the teachings of the present invention obtained by a therapeutic training device comprising a shallow housing of a specific shape having a quadratic top surface, a quadratic bottom surface and four thin rectangular side surfaces, the housing comprising: an upwardly open cavity in the top surface, a flexible and transparent cover enclosing the cavity at least partially, the flexible and transparent cover having a size in the range between the size of a human fist and the size of a human foot, and defining a central part, a force sensor placed inside the cavity and communicating with the central part, the force sensor measuring the force applied on the flexible and transparent cover and generating a response signal, a light source placed inside the cavity, the light source being visible through the flexible and transparent cover, a central processor placed inside the housing for activating the light sources in accordance with a specific software and evaluating the response signal from the force sensor in accordance with the specific software, and a plurality of communication means located on the side surfaces controlled by the central processor and communicating with adjacent devices. [0007] A user may interact with the therapeutic training device by applying a hand or a foot onto the flexible and transparent cover and the underlying force sensor. The flexible and transparent cover having a size between a human fist and a human foot should be understood to mean the flexible and transparent cover having a diameter preferably between 5 to 30 cm and most preferably around 15 cm. The flexible and transparent cover may be divided into one flexible but non-transparent part and one transparent but rigid part. The flexible part may preferably be made of a material of sufficient strength and shock resistance to be durable and at the same time the flexible part should be soft not to injure the user. Preferably, a plastic material is used. The light source may be used for giving instructions and information to the user. Alternatively, providing a sound pervious cover, the light source may be substituted with a sound source or a sound source may be used in addition to a light source. [0008] The therapeutical training device is based upon modern artificial intelligence and robotics. It is applicable for different forms of physical activities, for example therapeutic rehabilitation, exercise, physiotherapy, sports, fitness and entertainment. At the same time it gives unique possibilities for documentation of the physical activity for use in for example a therapeutic treatment. It is highly motivating due to immediate feedback and fun, interesting exercises. Several therapeutical training devices may be put together in a therapeutical training system forming an electronic, interactive surface on a floor or wall and each activity or therapeutic treatment may have its own appropriate control program or exercise. The use of the therapeutical training system motivates the user to perform physical activities by providing immediate feedback based upon physical interaction with the system and the user is able to make new physical set-ups within less than a minute. [0009] Processing in electronic devices is traditionally based on central control. This is the case in VCRs, televisions, mobile phones, industrial robots, toy robots, etc. In such cases, the device is controlled by an electronic system with a central control. If just a small part of the central control breaks down, the whole system/device may break down. The invention challenges the traditional central control, and allows processing to be distributed among a number of processing units that can connect together to form a larger, collective system. The individual therapeutical training device includes both processing capabilities and communication capabilities. The therapeutical training system comprising a number of therapeutical training devices allows the user to define the physical shape and the functionality of the therapeutical training system and to interact with the therapeutical training device. [0010] By enumeration of neighbours, the individual therapeutical training device is able to communicate with other specified therapeutical training devices in the system. The detection of neighbours and the overall structure can be done automatically by the system itself at run-time, which facilitates easy modification of the physical form by the user. With neighbour is meant any device adjacent to the side surfaces of the therapeutical training device and communicating with the therapeutical training device. Four neighbours are possible, designated north, south, east and west. [0011] User interaction and capabilities of constructing electronic devices are enhanced by particular processing methods. The invention allows construction of both the physical shape and functionality through the physical construction with no necessary computer skill or need for a personal computer, external programming station, monitor or the like. [0012] Exercises may be run as software on the therapeutical training system. The exercises may adjust themselves to fit any physical configuration constructed by the user. Each exercise may be adjusted to fit particular user groups and levels, such as therapeutic patients, fitness trainees, gamers, etc. [0013] The therapeutical training system may preferably be used for rehabilitation of cardiac patients. For cardiac patients, the exercises on the therapeutical training system may motivate a rise in pulse to appropriate levels. Due to the intellectually stimulating nature of the exercises, the patients find the rehabilitation activity fun and interesting. [0014] Use of the therapeutical training system is not limited to certain patient groups. For instance, exercises that demand the correct movement of the knee and the correct force exerted onto the force sensor will be suitable for knee operated patients. For hip patients the exercises may include walking paths that demand the appropriate weight and force applied on each of the therapeutical training devices, for elderly exercises that stimulate balance training, etc. [0015] Additionally, the therapeutical training system may be used for cognitive rehabilitation. Cognitive tasks may be implemented on the therapeutical training system and feedback (light & sound) may be given to the user based upon the performance of the user on the cognitive tasks. Users may be challenged with different cognitive exercises and the exercises may be easily adjustable to the different capabilities of different users. This may for example be imitation exercise for autistic children. [0016] Further, the therapeutical training system may be used for fitness training and sports training. For example, the therapeutical training system can be set up for precision shooting in football or handball training. Exercises may provide light patterns of different velocity with the purpose of the sport trainee to hit the light and receive feedback (light & sound) from the therapeutical training system when doing so, e.g. to obtain an overall score. Fitness training is often a repetitive and individual activity. The therapeutical training system provides fitness training in the form of fun and challenging exercises that adapt the training level according to the capability of the trainee. [0017] Additionally, the exercises may be of social type by allowing a plurality of users to compete against each other in different exercises on a single therapeutical training system. Hence, the therapeutical training system may be used for individual training by a single user or for simultaneous training by a group of users. Exercises may be designed to allow rehabilitation activities to be performed by a plurality e.g. two, three or four patients at the same time. In this way the rehabilitation exercise may become a competitive exercise between patients. Other user groups such as e.g. fitness trainees, sports trainees, etc. may also use the social type exercises. In activities such as physiotherapy and fitness training the invention provides a unique opportunity for such social activities and challenges for instance in therapeutic rehabilitation practices. With other tools used for such training sessions such social use is often lacking and/or impossible. [0018] Additionally, the therapeutical training system may be used to define musical expressions for music composition and live music performances. For instance, the physical interaction may control different MIDI sequences and thereby, for instance, allow music composers to play music on the therapeutical training system or allow a music concert audience to participate in live music concerts by interacting with the therapeutical training system or allow home users to interact with music albums. [0019] The therapeutical training system may be easily set up on the floor or wall within one minute. The therapeutical training devices may simply attach to each other with magnets or alternatively another attachment mechanism. Preferably, infrared communication means are used to avoid having to connect any wires. The therapeutical training system may register whether it is placed horizontally or vertically, and may by itself make the software exercises behave accordingly. [0020] Additionally, a plurality of therapeutical training systems may be put together in a group and communicate with each other wireless. For instance, an exercise may be running distributed on a group of therapeutical training systems on the floor and a group of therapeutical training systems on the wall, demanding the user to interact physically with both the floor and the wall. A master device or a personal computer may be used for communication between the therapeutical training systems. [0021] The special features of the currently preferred embodiment of the invention include the modularity, the possibility for users to modify the physical shape, the easy setup, the possibility of exclusion of an external host computer, the self-contained energy source, the wireless communication (local and global), and the individual exercises. [0022] Additionally, the therapeutic therapy system may include means of logging response signals from the force sensor on a memory unit and displaying the response signals or a result derived from the response signals on a display unit, monitor, personal computer or by means or light and/or sound signals. The memory unit may preferably be a RAM, hard disk or CD/DVD unit. The memory unit may be communicating with the therapeutic training device and/or the master device. The memory unit may alternatively be a part of the therapeutic training device and/or the master device. [0023] The present invention also relates to a method of performing a physical therapy on a patient or person by providing the therapeutic training system as described above, loading the software comprising an exercise program on the therapeutic training system, the exercise program comprising a series of predefined exercises, wherein each exercise comprises at least the following steps: instructing the patient by activating the light source and/or sound source of a specific therapeutic training device to apply a force onto the central part of the specific therapeutic therapy devices, and logging the response signal of the force sensor of the specific therapeutic training device. [0024] The word patient should in this context be interpreted in its broadest sense and not limit the users to therapeutical users. Thus, the word patient also includes all possible professional and leisure users of the therapeutical training system such as for example sports trainees, gamers and the like. [0025] It is further evident that numerous variations of the exercise program described in the method above may be realized. It follows a comprehensive but not limiting description of alternative methods according to the present invention: [0026] The method of performing a physical therapy as described above, wherein the exercise program comprises a precision game, wherein an object is used for applying a force on the central part of the specific therapeutic therapy device, the object being for example a football, a soccer ball, a basketball, a tennis ball or a handball. [0027] The method of performing a physical therapy as described above, wherein the exercise program comprises a balance game, wherein the therapeutic training system is located in a horizontal position preferably on a floor and the patient is instructed by the light sources and/or sound sources to walk according to a specific path on the therapeutical therapy system and thereby sequentially applies a force onto the central part of a plurality of the therapeutical therapy devices. [0028] The method of performing a physical therapy as described above, wherein the exercise program comprises a musical game, wherein the therapeutic training devices each trigger a different music sequence, allowing e.g. a music composer to compose a concert or interact with a music album by applying a force onto the central part of a plurality of the therapeutical therapy devices. [0029] The method of performing a physical therapy as described above, wherein the exercise program comprises a memory game, wherein the patient must memorize a sequence of light or sound signals and subsequently apply a force onto the central part of a plurality of the therapeutical therapy devices according to the sequence. [0030] The method of performing a physical therapy as described above, wherein the exercise program comprises a dancing game, wherein the therapeutic training system shows a light sequence and plays a music sequence and the patient moves his/her feet to apply a force onto the central part of the therapeutic training device in a sequence according to the light sequence and the music. [0031] The method of performing a physical therapy as described above, wherein the exercise program comprises a color game, wherein each color is representing a specified body part, a therapeutical training device showing a randomly selected color and the patient is applying a force onto the central part of the therapeutic training device using the designated body part. [0032] The method of performing a physical therapy as described above, wherein the exercise program comprises a multiplayer game, wherein a plurality of patients are interacting with one or more therapeutic training systems, thereby the number of therapeutical training devices is at least the same number as the number of patients. BRIEF DESCRIPTION OF THE DRAWINGS [0033] FIG. 1 illustrates a plurality of therapeutical training devices. [0034] FIG. 2 illustrates a single therapeutical training device. [0035] FIG. 3 illustrates an exploded view of a single therapeutical training device. [0036] FIG. 4 a is a 3D view of a front of a single therapeutical training device. [0037] FIG. 4 b is a different 3D view of a front of a single therapeutical training device. [0038] FIG. 4 c is a different 3D view of a front of a single therapeutical training device. [0039] FIG. 4 d is a rear view of a single therapeutical training device. [0040] FIGS. 5 a - 5 d illustrate a transparent view of a single therapeutical training device from different angles. [0041] FIGS. 6 a - 6 j illustrate a flow chart of a printed circuit board of a single therapeutical training device. [0042] FIG. 7 is a layout of a circular printed circuit board. [0043] FIGS. 8 a - 8 d illustrate a flow chart of a PLB add-on chip. [0044] FIG. 9 illustrates a physical layout of a PLB add-on chip. [0045] FIGS. 10 a 1 , 10 a 2 and 10 b are charts of component parts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0046] A detailed description of the figures of a presently preferred embodiment of the invention follows below. [0047] FIG. 1 shows a 2D view of a therapeutical training system ( 10 ) according to the invention. The therapeutical training system ( 10 ) comprises a number of therapeutical training devices ( 12 ) of quadratic shape oriented side-by-side forming a planar and flat structure. Each therapeutical training device ( 12 ) is oriented in a specific orientation juxtaposed to at least one other therapeutical training device ( 12 ) and has a user interface oriented in a certain direction towards the user. The therapeutical training device ( 12 ) further has communicating features for communicating with other therapeutical training devices ( 12 ). The master device ( 12 ′) has all the features and abilities of a therapeutical training device ( 12 ) and additional features, which will be described in detail later. The shown embodiment of the therapy system ( 10 ) includes 12 therapeutical training devices ( 12 ) and one master device ( 12 ′). The number of master devices ( 12 ′) must be one, whereas the number of therapeutical training devices ( 12 ) may vary. [0048] FIG. 2 shows a 3D view of a therapeutical training device ( 12 ) having a shallow and quadratic casing ( 20 ). The casing ( 20 ) is preferably moulded in a plastic material, such as for example polyurethane. The casing ( 20 ) further encompasses a quadratic front surface ( 14 ), a quadratic back surface ( 16 ) opposite the front surface ( 14 ) and four shallow rectangular side surfaces ( 18 ). The top surface ( 14 ) comprises a user interface having a centrally located circular cover ( 26 ) and an outer ring shaped transparent plate ( 24 ) surrounding a circular cover ( 26 ). The transparent plate ( 24 ) is preferably made of a robust plastic material such as Plexiglas and is fixed onto the casing. The circular cover ( 26 ) is preferably made of a robust plastic material and is flexible in its position. With flexible is in this context meant that the circular cover ( 26 ) either may be placed loosely in the transparent plate ( 24 ) permitting the circular cover ( 26 ) to be moved a certain distance into the casing ( 20 ) or the circular cover ( 26 ) being fixated to the casing ( 20 ) but soft and easily stretchable and able to protrude a certain distance into the casing when applying a force onto the circular cover ( 26 ). [0049] FIG. 3 shows a 3D exploded view of a therapeutical training device ( 12 ). The top surface ( 14 ) comprises a centrally located circular cavity ( 30 ). The cavity ( 30 ) comprises a centrally located raised platform ( 28 ) protruding a distance less than the depth of the cavity. Between the raised platform ( 28 ) and the circular cover ( 26 ) a force sensitive resistor (FSR, not shown) is located sensing the force applied from the outside onto the circular cover ( 26 ). The circular cavity ( 30 ) further comprises a circular printed circuit board (PCB, not shown). Each of the four sides ( 18 ) of the therapeutical training device ( 12 ) comprises two permanent magnets ( 32 ) oriented in view of polarity in such a way that attachment to other therapeutical training devices ( 12 ) is permitted. The strength of the permanent magnets ( 32 ) should be chosen to allow simple attachment and detachment by use of hand force, and still provide sufficient strength to hold the therapeutical training devices ( 12 ) fixated and clustered during use as a therapeutical training system ( 10 ). Electro magnets may in an alternative embodiment replace the permanent magnets. Each side ( 18 ) of the therapeutical training device ( 12 ) further comprises a centrally located communication port ( 34 ) forming a tubular channel extending from the outside into the circular cavity ( 30 ) housing the PCB. The communication port ( 34 ) preferably uses IR (infrared) communication means for exchange of information with other therapeutical training devices ( 12 ). One of the sides of the therapeutical training device ( 12 ) further comprises a battery charging port ( 36 ), used for connecting a battery charger to charge the internal batteries (not shown) located on the PCB (not shown). [0050] FIG. 4 a shows a different 3D view of the front surface ( 14 ) of a therapeutical training device ( 12 ). The circular cavity ( 30 ) is provided with four fixation studs ( 38 ) for fixating the PCB (not shown) inside the circular cavity ( 30 ). [0051] FIG. 4 b shows a different 3D view of the front surface ( 14 ) of a therapeutical training device ( 12 ). The circular cavity ( 30 ) is provided with a data communication port ( 42 ) for communicating to an external PC (personal computer). The data communication port ( 42 ) comprises a JTAG programming plug used for attaching a programming cable allowing the PCB to be configured using e.g. an external PC. [0052] FIG. 4 c shows a different 3D view of the front surface ( 14 ) of a therapeutical training device ( 12 ). [0053] FIG. 4 d shows a different 3D view of the back surface ( 16 ) of a therapeutical training device ( 12 ). The back surface ( 16 ) comprises four wall fixation magnets ( 40 ) for use when the therapy system ( 10 ) is used vertically mounted onto e.g. a wall. The back surface ( 16 ) further comprises the outside end of the data communication port ( 42 ) [0054] FIGS. 5 a - 5 d show a 3D transparent view of a therapeutical training device ( 12 ) from a variety of angles. [0055] FIGS. 6 a - 6 j show a flow chart view of a printed circuit board PCB ( 50 ) of a device. In the centre of the PCB ( 50 ) the microprocessor ( 60 ) can be found. The ATmega 1280 microprocessor ( 60 ) is used for controlling all the other components and for running various kind of software such as games. Four IR communication units ( 52 ) communicate to the microprocessor ( 60 ) and further detects if any other device is assembled in any of the four neighbouring positions and if such neighbouring device or devices are present communicating using infrared light to the neighbouring devices. Each IR communication unit ( 52 ) comprise a separate encoder and transceiver. Further connected to the microprocessor are eight LED (light emitting diode) units ( 54 ). The LED unit ( 54 ) each comprise three LED:s of different colors (blue, red and green). The battery unit ( 56 ) holds the three NIMH rechargeable batteries and includes a circuitry for monitoring the charge level of the batteries as well as controlling charging and discharging of the batteries. Low battery level is detected by the battery unit ( 56 ) and indicated to the user by the LED units ( 54 ). The user can recharge the batteries by simply connecting a separate charger unit (not shown) to the battery charging port ( 36 ), which in turn is connected to the battery unit ( 56 ). The time needed to fully charge the discharged batteries is 16-18 hours. For avoid unnecessary battery wear, the PCB ( 50 ) will power down if the therapeutical training device ( 12 ) is left unused for more than 5 minutes or if the therapeutical training device ( 12 ) is removed from the therapy system ( 10 ). The 2D accelerometer ( 58 ) detects horizontal or vertical placement of the device. Additionally, a wireless communication unit ( 62 ) and a force sensitive resistor ( 64 ) are connected to the microprocessor ( 60 ). The FSR preferably has a limiter, thus not reporting very low forces and limiting very high forces. The FSR may be analogue or digital. [0056] FIG. 7 shows a physical layout view of a circular printed circuit board PCB ( 50 ) designed to be fitted in the circular cavity ( 30 ). The four IR communication units ( 52 ) are located close to the edge of the PCB ( 50 ) separated by 90 degrees in such a way that each IR communication unit ( 52 ) match a corresponding communication port ( 34 ) at each side surface ( 16 ) and permit a direct line-of-sight to the communication port and IR communication unit of a connected neighbouring device. The word match should in this context be understood to mean that the IR communication unit ( 52 ) should be positioned in a way to enable IR communication from a specific IR communication unit ( 52 ) through a specific communication port ( 34 ) and further through a communication port ( 34 ) of a neighbouring device to a IR communication unit ( 52 ) of a neighbouring device if such a neighbouring device is available in the present structure of the therapeutical training device ( 10 ). If such a neighbouring device is present between the communicating IR communication units and IR communication can be performed successfully, the software running on the therapeutical training system ( 10 ) will be informed about the position of the neighbouring device. If IR communication cannot be established, the software assumes no neighbouring device in the specific position. Each therapeutical training device ( 12 ) may have up to four neighbouring devices separated by 90 degrees, i.e. a neighbour to the north, south, east and west. The software running on the therapeutical training system will further be updated if any devices are added or removed from the therapeutical training device. In this context device may mean a therapeutical training device ( 12 ) as well as other devices and apparatus compatible with the hardware and software of a therapeutically training device. With IR communication should be understood both sending and receiving of IR data signals. The data signals are preferably digital coded signals, however, analogue communication may be possible as well. The eight LED units ( 54 ) should be positioned to allow light signals from the LED units ( 54 ) to penetrate the transparent plate ( 24 ) and be clearly conceived by a user. For additional clarity and aesthetic appearance the LED units ( 54 ) are preferably distributed to form a circular appearance, i.e. being separated 45 degrees in this case of using eight LED units. The battery unit ( 56 ) includes three battery holders, fitted on top of the PCB ( 50 ) for easy access and designed for AA rechargeable batteries. [0057] FIGS. 8 a - 8 d show a flow chart view of the PCB add-on chip ( 70 ) used in the master device ( 11 ′) only. The PCB add-on chip ( 70 ) comprises a radio communication unit ( 74 ) (XBee) used by the master device to enable wireless communication with other master devices of other therapy systems. Such wireless communication may be utilized for combining two therapeutical training systems into one therapeutical training system without the need of a physical connection. Further use involves running specific software on the master device such as for example comparing results of different patient running the same exercise simultaneously or controlling the therapy system from an external PC. A display unit ( 76 ) for showing text messages and an array of buttons ( 72 ) comprising four buttons are provided on the master device ( 70 ) for direct user interaction. The buttons are used to setup the software. The charge pump ( 78 ) (TPS60130) is used to provide power to the circuitry. [0058] FIG. 9 shows a physical layout view of the PCB add-on chip ( 70 ). The PCB add-on chip ( 70 ) is mounted on the circular printed circuit board PCB ( 50 ). The array of buttons ( 72 ) is located such as to be operated from the outside of the device in a convenient way. The casing ( 20 ) for the master device ( 12 ′) is to be modified in a way to fit the array of buttons ( 72 ) in a convenient and user-friendly way. The buttons are used to interact with the software running on the therapeutical training device. The radio communication unit ( 74 ), the display unit ( 76 ) and the charge pump ( 78 ) are located on the PCB add-on chip ( 70 ) as well. [0059] Upon assembling the therapy system, the hardware will detect the physical structure of the therapeutical training system as described above. The software will use the information of the physical structure in setting up a therapeutical training program and evaluating the result of the patient. Below numerous embodiments of therapeutic exercises or games will be described in detail. [0060] On the presently preferred embodiment of the invention, software can run on the ATmega 1280 microprocessors in the therapeutical training devices. If the game “Chasing Colors” is chosen on the master device, the master device will ask for number of participants (1-6), and thereafter duration of play (0.5, 1, 1.5, 2, 2.5, 5 minutes). The physical structure of the therapeutical training device is checked and then the master device asks for start: when the down button is pressed the game will start. According to the number of players, that number of colors will show up at random therapeutical training devices on the therapeutical training system. For instance, if three players are selected, there will be one therapeutical training device lighting up in red, one therapeutical training device lighting up in blue, and one therapeutical training device lighting up in yellow. When one of the therapeutical training devices which is lightened up in a specific color is pressed, the information will be sent to the master device by IR communication. The master device counts up a variable of that color with one, the color will be turned off on the current therapeutical training device and shown at another randomly selected therapeutical training device. When the selected time has passed (e.g. 1 minute), the master device will check the different color variables and the color that was pressed most times (the winner) will be shown on all therapeutical training devices (i.e. the master device sends information to the therapeutical training devices to show that color). After 10 seconds of showing the winning color, the game will restart. [0061] Hence, in the presently preferred use of this game, the users will select the number of participants and duration of games, and then chase one color each. The user who hits most therapeutical training devices showing his/her color within the selected duration of a game will win the game, indicated by his/her color lighting up on all therapeutical training devices for 10 seconds, before a new game starts again. Users compete at the same time on one therapeutical training system and have to navigate around each other to “catch” the colors. In physiotherapy, sports and fitness training, this activity is used to create a rise in pulse amongst the participants. [0062] For instance, if the therapeutical training system is put as a structure on the floor, the participant will be walking, running or jumping around on the therapeutical training system to hit the ones with their individual color with the feet. Alternatively, some users may choose to crawl on the therapeutical training system and hit the therapeutical training devices with their hands or knees. If the therapeutical training system is put as a structure on a wall, the users will be moving around to hit the therapeutical training devices with their hands. [0063] The system, through the master device, checks the size of the structure using the IR communication units of each therapeutical training device in order not to allow more participants than there are therapeutical training devices available in the structure. The master device is always keeping track of number of therapeutical training devices in the structure (see description above). [0064] The game motivates to perform physical activities because it is fun, challenging and social. Similar games with similar attributes can be made on the therapeutical training system. [0065] In the game “Floor and Wall”, the user builds two therapeutical training systems, each having a master device. The two therapeutical training systems, designated “floor”-structure and “wall”-structure are physically separated (e.g. one structure is on the floor and one structure is on a wall or alternatively they are located in two different rooms or the like. The user selects “Floor” on one master device, number of players and duration of game, in the same way as for the Chasing Colors game described above. On the other master device, the user selects “Wall”. When start is indicated by pushing the down button on the “Floor” master device, the game will start on both “floor”-structure and “wall”-structure. The game is similar to the Chasing Colors game: a specific color appears either on the “floor”-structure or on the “wall”-structure. The two master devices communicate with each other by radio communication (XBee), and thereby the “floor” master device can send colors to randomly chosen therapeutical training devices either the “floor” structure or the “wall” structure. Other games using distributed therapeutical training systems that communicate with radio communication may be implemented. [0066] In the “Simon says” game, the user only has to press start. When the game starts, one therapeutical training device will light up for 3 seconds and then turn off. The user now has to repeat by pressing on that specific therapeutical training device to make it light up. If the user presses the therapeutical training device that lighted up before, then it is correct, and all therapeutical training devices will light up in green for 3 seconds. If the user presses any other therapeutical training device, then all therapeutical training devices will light up in red, and the game will end. In the case of the correct action, the game will now show the first therapeutical training device light up again, turn off, and show a second therapeutical training device light up for 3 seconds before it turns off. The user now has to repeat the sequence on pressing the two therapeutical training devices in the order that was shown by the system. If the order that the user presses is correct, then all devices light up in green, else they light up in red and the game ends. The game continues allowing the user to try to repeat 3 lights, 4 lights, 5 lights, 6 lights, etc. until the user makes an error by pressing a therapeutical training device in the incorrect sequence. Users can compete against themselves on how long sequences they can make, and they can compete against each other on how long sequences they can make. The users can build different physical therapeutical training device structures to run the game on, in order to make the game easier or more difficult. Similar cognitive tasks, memory and imitation games can be made and, for instance, used in cognitive rehabilitation with the aspect of being both cognitive and physical games. [0067] In the “Disco” game, a therapeutical training device lights up in a random color when it is pressed. If no therapeutical training device is pressed for 2 seconds, then all therapeutical training devices will turn off. Hence, the user can move around and continuously press the therapeutical training devices to make them change color (e.g. from red to blue to yellow to magenta to green to purple, etc.). The user may choose to play external music along with playing the game. Similar dancing games can be implemented on the therapeutical training system. [0068] There are also one-player games such as “Stepper”. The user selects the duration of game (0.5, 1, 1.5, 2, 2.5, 5 minutes). In Stepper, the master device will investigate the physical structure built by the user and find the longest rectangle with 2 therapeutical training devices on one side (i.e. 2*2, 2*3, 2*4, 2*5, . . . ). It will indicate by color on the first two that the user should place him/herself with a foot on each of these two. On the two therapeutical training devices furthest away, light will show in colors depending on the speed with which the user steps on the two therapeutical training devices where he/she is positioned. The indicator therapeutical training devices will show up in yellow, green and red in this order based on the speed on the stepping. [0069] In the “Reach” game, the start procedure is similar to the Stepper game. Here the user has to reach out and touch the therapeutical training devices that light up. The therapeutical training devices light up in a color that may indicate that the user should use the left or right leg/arm to reach out and touch that therapeutical training device. The user can also select if the touch to activate the therapeutical training devices should be light, middle or hard (which is measured by the analogue FSR sensor). This may, for instance, allow physiotherapists and fitness trainers to select level for specific users. The “Reach” game can, for instance, be used for balance training. [0070] In the “Ball game”, the user selects the level (1, 2, 3) and the duration of the game (0.5, 1, 1.5, 2, 2.5, 5 minutes). The master device will send information to the therapeutical training devices to have a light signal traverse the therapeutical training devices in different patterns (depending on the chosen level), for instance horizontally. The user now has to hit the therapeutical training devices that light up with a ball (e.g. football or handball) from a distance chosen by the user. If the user hits the light a specific number of times (depending on the level) within the duration of the game, all therapeutical training devices will show up in blinking green, indicating that the user has won the game. A similar game may be used for e.g. racket sports. [0071] Additional features of the preferred embodiment of the invention include a battery management system. When the battery level of a therapeutical training device is low, this will be indicated by the lights of the therapeutical training device rotating in red, while in a master device it will be written in the display. A charger can be attached to the block in the charging plug on the side of the therapeutical training devices, and the batteries will be fully recharged within 16-18 hours. [0072] The therapeutical training system consists of a number of therapeutical training devices as described above. The therapeutical training devices can be put together to form different structures. The magnets on the sides of the therapeutical training devices makes the blocks snap and hold together. When a master device is put together with a cluster of one or more therapeutical training devices, the master block will send IR signals to the first neighbouring therapeutical training device, which will receive this IR signal as a wake-up signal and relay the signal to its own neighbours by IR communication to its North, East, South, West side. Where there is a therapeutical training device on the North, East, South or West, that (those) therapeutical training device(s) will then, at its (their) turn, relay the signal to its (their) own neighbours. And those therapeutical training devices will receive and relay the signal, and so forth. When a therapeutical training device receives a signal, it sends back a receipt, so a sending therapeutical training device can obtain knowledge about its own neighbourhood structure by keeping track of from where it receives receipts. For instance, it will have a neighbour to the North if it receives a receipt from North. The neighbourhood structure of a therapeutical training device is sent back to the device from which it received the signal, and so the different neighbourhood structures can be relayed back to the master device. Based on this information, the master device can simply build a tree structure and a map of the layout of the therapeutical training devices. This map of the physical structure, which has been built by the user, is used by the system for the different software games. The therapeutical training devices will continuously send IR signals to their North, East, South, West neighbours and receive receipts from those positions that are occupied by other blocks. If they receive signals from a position, which was not occupied at the previous time stamp, or if they do not receive signals from a position that was occupied at the previous time stamp, then the system recognizes that the structure has been changed (either by the addition of a block or the removal of a block). If this happens, the master block will re-initiate a count of blocks and their positions in order to build an updated tree structure and map of the physical layout. Hence, the recognition of changes in structure happens immediately at run-time. Therefore, it becomes possible for the user to build different structures with the therapeutical training devices, and possible for the system itself to recognize what structure the user has built. [0073] If the therapeutical training devices are not used for 5 minutes, they will power down. Also, if a therapeutical training device is removed from the structure, it will blink three times and then power down. [0074] With the system's knowledge of the physical structure and the continuous update of possible changes to the structure, the software games can utilize the physical structure to make games automatically become appropriate to the individual structures. The softwares (games) can adjust themselves when the structure is changed. [0075] The buttons on the master device can be used to select games. In the prototype implementation, there are four buttons on the master device: home, left arrow, right arrow, down arrow. A small display on the master device will show text information. Initially, it will tell that the structure is being detected and print the number of therapeutical training devices found in the structure. Then the software will ask the user to select a game. By pressing the left arrow or the right arrow, the user may browse backward or forward in the list of games. The down button can be used to select one of the games. When a game is selected, the software may ask for further details from the user such as number of players, which again is selected by the arrows. Other selections to be made may include game level and duration of play. [0076] When a game has been selected on the master device and possibly other options selected, the master device will send this information through the tree structure to all the therapeutical training devices, and the game will start. [0077] Although the present invention has been described above with reference to specific and presently preferred embodiments of a therapy system and other devices and methods also constituting a part of the invention, it will be evident to a person having ordinary skill in the art that the therapy system including all of the devices and methods may be modified in numerous ways. [0078] For example, it would be evident to a person skilled in the art that the invention may be performed using different energy sources, such as solar power or retrieval of energy from the physical activation of the system. Single use batteries or an external AC or DC source may replace the rechargeable batteries. The devices may be moulded in another plastic material and another transparent material could be used for the transparent ring. A flexible film or foil may be used instead of the circular cover and function as buttons or the buttons may be reinforced. The shape of the device may take other forms than quadratic and still allowing the devices to be assembled to form an overall structure (e.g. like a puzzle), and the surface may comprise grooves and be generally uneven. Additionally, light could be emitted in other patterns than a ring, such as for example a square or circle, or sound effects may replace or accompany the light. The electronic components could be substituted for other, similar components. The PCB may be chosen to have a different form in order to minimize the PCB size. The hardware may be fully or to a large extent be replaced by a personal computer. The communication between the devices may be performed by other means than IR, such as for example by radio or wire. Software features may be controlled differently such as for example by pressing on one or more of the devices or an RFID system with RFID tags may be applied for game selection. Additional software features may be implemented, such as other games. For instance, a Music game may allow the user to control MIDI signals by pressing the different therapeutical training devices and a specific sound device may be used for playing the MIDI signals. Such a sound device may include all the features of the before mentioned therapeutical training devices additionally including a sound PCB and MIDI chip add-on. Alternatively, the sounds may be played on a host computer, with the signal being sent preferably by radio communication from the master device. LIST OF PARTS [0000] 10 Therapy system 12 Therapeutical training device 12 ′ Master device 14 Front surface 16 Back surface 18 Side surface 20 Casing 24 Transparent plate 26 Circular cover 28 Raised platform 30 Circular cavity 32 Magnet 34 Communication port 36 Battery charging port (connector) 38 Fixation stud 40 Wall fixation magnet 42 Data communication port 50 Printed circuit board PCB 52 IR communication unit 54 LED unit 56 Battery unit 58 2D Accelerometer 60 Microprocessor 62 wireless communication unit 64 Force sensitive resistor 70 PCB add-on chip 72 Array of buttons 74 Radio communication unit 76 Display unit 78 Charge pump

A therapeutic training device includes a shallow housing of a specific shape with a quadratic top surface, a quadratic bottom surface and four thin rectangular side surfaces. The housing includes an upwardly open cavity in the top surface and a flexible and transparent cover which encloses the cavity at least partially. The flexible and transparent cover has a size in the range between the size of a human fist and the size of a human foot, and defines a central part. The housing further includes a force sensor placed inside the cavity communicating with the central part. The force sensor measures the force applied on the flexible and transparent cover and generates a response signal. The housing further includes a light source placed inside the cavity, the light source being visible through the flexible and transparent cover, and a central processor placed inside the housing, which activates the light sources in accordance with a specific software and evaluates the response signal from the force sensor in accordance with the specific software. A plurality of communication devices are located on the side surfaces and is controlled by the central processor and communicates with adjacent devices.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation and claims the benefit of U.S. application Ser. No. 12/953,158, which is a continuation and claims the benefit of U.S. application Ser. No. 12/284,790, which is a continuation and claims the benefit of U.S. application Ser. No. 10/941,226, filed on Sep. 14, 2004, now U.S. Pat. No. 7,446,030, issued Nov. 4, 2008, which is a continuation-in-part of U.S. application Ser. No. 10/315,496, filed on Dec. 9, 2002, now U.S. Pat. No. 6,767,145, which is a continuation of U.S. application Ser. No. 09/437,882, filed Nov. 10, 1999, now abandoned, which claims the priority benefit of U.S. Provisional Application No. 60/151,188, filed on Aug. 27, 1999. Each of the above referenced applications is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to the field of current-carrying devices and components. In particular, the invention relates to a current-carrying device including a substrate and a conductive layer. [0004] 2. Description of the Related Art [0005] Current-carrying structures are generally fabricated by subjecting a substrate to a series of manufacturing steps. Examples of such current-carrying structures include printed circuit boards, printed wiring boards, backplanes, and other micro-electronic types of circuitry. The substrate is typically a rigid, insulative material such as epoxy-impregnated glass fiber laminate. A conductive material, such as copper, is patterned to define conductors, including ground and power planes. [0006] Some prior art current-carrying devices are manufactured by layering a conductive material over a substrate. A mask layer is deposited on the conductive layer, exposed, and developed. The resulting pattern exposes select regions where conductive material is to be removed from the substrate. The conductive layer is removed from the select regions by etching. The mask layer is subsequently removed, leaving a patterned layer of the conductive material on the surface of the substrate. In other prior art processes, an electroless process is used to deposit conductive lines and pads on a substrate. A plating solution is applied to enable conductive material to adhere to the substrate on selected portions of the substrate to form patterns of conductive lines and pads. [0007] To maximize available circuitry in a limited footprint, substrate devices sometimes employ multiple substrates, or use both surfaces of one substrate to include componentry and circuitry. The result in either case is that multiple substrate surfaces in one device need to be interconnected to establish electrical communication between components on different substrate surfaces. In some devices, sleeves or vias provided with conductive layering extend through the substrate to connect the multiple surfaces. In multi-substrate devices, such vias extend through at least one substrate to interconnect one surface of that substrate to a surface of another substrate. In this way, an electrical link is established between electrical components and circuitry on two surfaces of the same substrate, or on surfaces of different substrates. [0008] In some processes, via surfaces are plated by first depositing a seed layer of a conductive material followed by an electrolytic process. In other processes, adhesives are used to attach conductive material to via surfaces. In these devices, the bond between the vias and conductive material is mechanical in nature. [0009] Certain materials, referred to below as voltage switchable dielectric materials, have been used in prior art devices to provide over-voltage protection. Because of their electrical resistance properties, these materials are used to dissipate voltage surges from, for example, lightning, static discharge, or power surges. Accordingly, voltage switchable dielectric materials are included in some devices, such as printed circuit boards. In these devices, a voltage switchable dielectric material is inserted between conductive elements and the substrate to provide over-voltage protection. SUMMARY [0010] Various aspects include a method for fabricating a current-carrying formation. The method comprises providing a first voltage switchable dielectric material having a first characteristic voltage, exposing the first voltage switchable dielectric material to a first source of ions associated with a first electrically conductive material, and creating a first voltage difference between the first source and the first voltage switchable dielectric material. The first voltage difference may be greater than the first characteristic voltage. Electrical current is allowed to flow from the first voltage switchable dielectric material, and the first electrically conductive material is deposited on the first voltage switchable dielectric material. [0011] In some cases, the first voltage switchable dielectric material may be exposed to a second source of ions associated with a second electrically conductive material. In such cases, a second voltage difference, greater than the first characteristic voltage, may be created between the first voltage switchable dielectric material and the second source. Electrical current is allowed to flow from the first voltage switchable dielectric material during application of the second voltage difference, and the second electrically conductive material is deposited on the first voltage switchable dielectric material. [0012] In certain aspects, a second voltage switchable dielectric material is provided, which may have a second characteristic voltage. A second voltage difference, greater than the second characteristic voltage, is created between the first source and the second voltage switchable dielectric material. Electrical current is allowed to flow from the second voltage switchable dielectric material, and the first electrically conductive material is deposited on the second voltage switchable dielectric material. [0013] In some aspects, a second voltage difference, greater than the first characteristic voltage, may be created between the first source and the first voltage switchable dielectric material, and the first electrically conductive material may be deposited on the first voltage switchable dielectric material while it is subject to the second voltage difference. [0014] Voltage switchable dielectric materials may be disposed on one or more substrates, and in some cases, a substrate may be flexible. [0015] Some aspects include masking a portion of a voltage switchable dielectric material, such that the masked portion is not exposed to the first source. In some cases, the first electrically conductive material is deposited on an unmasked region of the first voltage switchable dielectric material. [0016] Various aspects include a body comprising a voltage switchable dielectric material and a conductive material deposited on the voltage switchable dielectric material using an electrochemical process. In some cases, the conductive material is deposited using electroplating. [0017] Aspects include a body comprising a first conductor, a second conductor, and a voltage switchable dielectric material separating the first and second conductor. In some cases, the voltage switchable dielectric material includes a current-carrying formation that electrically connects the first and second conductors. Some current-carrying formations include a via. Some current-carrying formations are fabricated using an electrochemical process. [0018] Various aspects include bodies comprising RFID cards, smart cards, printed wiring boards, flex circuits, wafers, and printed circuit boards. BRIEF DESCRIPTION OF FIGURES [0019] FIG. 1 illustrates a single-sided substrate device including a voltage switchable dielectric material, under an embodiment of the invention. [0020] FIG. 2 illustrates electrical resistance characteristics of a voltage switchable dielectric material, under an embodiment of the invention. [0021] FIGS. 3A-3F show a flow process for forming the device of FIG. 1 . [0022] FIG. 3A illustrates a step for forming a substrate of voltage switchable dielectric material. [0023] FIG. 3B illustrates a step of depositing a non-conductive layer on the substrate. [0024] FIG. 3C illustrates a step of patterning a non-conductive layer on the substrate. [0025] FIG. 3D illustrates a step of forming a conductive layer using the pattern of the non-conductive layer. [0026] FIG. 3E illustrates a step of removing the non-conductive layer from the substrate. [0027] FIG. 3F illustrates the step of polishing the conductive layer on the substrate. [0028] FIG. 4 details a process for electroplating current-carrying structures on a substrate formed from voltage switchable dielectric material, under an embodiment of the invention. [0029] FIG. 5 illustrates a dual-sided substrate device formed from voltage switchable dielectric material and including a via interconnecting current-carrying formations on both sides of the substrate, under an embodiment of the invention. [0030] FIG. 6 illustrates a flow process for forming the device of FIG. 5 . [0031] FIG. 7 illustrates a multi-layered substrate device including substrates formed from voltage switchable dielectric material, under an embodiment of the invention. [0032] FIG. 8 illustrates a process for forming the multi-substrate device of FIG. 7 . [0033] FIG. 9 illustrates an exemplary waveform for a pulse plating process according to an embodiment of the invention. [0034] FIG. 10 illustrates an exemplary waveform for a reverse pulse plating process according to an embodiment of the invention. [0035] FIG. 11 illustrates a segment of an interior structure of a connector, the segment having exposed pin receptacles according to an embodiment of the invention. [0036] FIG. 12 shows a perspective view of a portion of the segment of FIG. 11 with a mask disposed thereon, according to an embodiment of the invention. DETAILED DESCRIPTION [0037] Embodiments of the invention use a class of material, referred to herein as voltage switchable dielectric materials, to develop current-carrying elements on a structure or substrate. The electrical resistivity of a voltage switchable dielectric material can be varied between a non-conductive state and a conductive state by an applied voltage. Methods of the invention render the substrate or structure conductive by applying a voltage to the voltage switchable dielectric material, then subjecting the substrate or structure to an electrochemical process. This process causes current-carrying material to be formed on the substrate. The current-carrying materials can be deposited on select regions of the substrate to form a patterned current-carrying layer. The applied voltage is then removed so that the substrate or structure returns to the non-conductive state after the current-carrying layer has been patterned. As will be further described, embodiments of the invention provide significant advantages over previous devices having current-carrying structures. Among other advantages, current-carrying material can be patterned onto the substrate with fewer steps, thus avoiding costly and time-consuming steps such as etching and electroless processes. [0038] Voltage switchable dielectric materials may also be used for dual-sided and multi-substrate devices having two or more substrate surfaces containing electrical components and circuitry. Vias in substrates formed from voltage switchable dielectric materials can interconnect electrical components and circuitry on different substrate surfaces. A via can include any opening of a substrate or device that can be provided with a conductive layer for the purpose of electrically interconnecting two or more substrate surfaces. Vias include voids, openings, channels, slots, and sleeves that can be provided with a conductive layer to interconnect electrical components and circuitry on the different substrate surfaces. Under embodiments of the invention, plating a via can be accomplished during a relatively simple electrochemical process. For example, vias in a voltage switchable dielectric material substrate may be plated using an electrolytic process. The vias can also be formed concurrently during the electrolytic process used to pattern one or more conductive layers on a substrate surface or surfaces of the device. [0039] In an embodiment of the invention, a current-carrying structure is formed from a voltage switchable dielectric material. A current-carrying formation can be formed on a plurality of selected sections of a surface of the substrate. As used herein, “current carrying” refers to an ability to carry current in response to an applied voltage. Examples of current-carrying materials include magnetic and conductive materials. As used herein, “formed” includes causing the current-carrying formation to form through a process in which a current-carrying material is deposited in the presence of a current applied to the substrate. Accordingly, current-carrying material may be electrodeposited onto the surface of the substrate through processes such as electroplating, plasma deposition, vapor deposition, electrostatic processes, or hybrids thereof. Other processes may also be used to form the current-carrying formation in the presence of an electrical current. The current-carrying formation may be incrementally formed so that a thickness of the current-carrying formation is developed by deposition of like material onto selected sections of the substrate. [0040] An electrobonding interface is formed between the current-carrying formation and the substrate. The electrobonding interface comprises an interface layer of electrobonds between the current-carrying formation and the substrate. The electrobonds are bonds formed between molecules of the substrate and molecules of the current-carrying material that are electrodeposited onto the substrate. The electrobonds form in regions of the substrate where additional current-carrying material is deposited to form the current-carrying formation. [0041] As electrobonds form between molecules, electrobonds exclude bonds formed as a result of electroless processes where molecules of the current-carrying material may be mechanically or otherwise added to the surface. Electrobonds exclude bonds formed in processes that include, for example, seeding conductive material onto the substrate using adhesives and other types of mechanical or chemical bonds. Examples of processes where current-carrying material may be electrodeposited to form electrobonds include electroplating, plasma deposition, vapor deposition, electrostatic processes, and hybrids thereof. [0042] A nonconductive layer may be patterned onto the surface of the substrate to define the selected sections of the substrate. The substrate is then subjected to an electrochemical process to incrementally form the current-carrying formation on the selected regions of the substrate. The non-conductive layer may comprise a resist layer that is removed once the current-carrying formation is formed on the select regions of the substrate. The non-conductive layer can also be formed from screened resist patterns, which can either be permanent or removable from the substrate. [0043] A voltage switchable dielectric material is a material that is non-conductive until a voltage is applied that exceeds a characteristic threshold voltage value. Above the characteristic threshold voltage value the material becomes conductive. Therefore, a voltage switchable dielectric material is switchable between a non-conductive state and a conductive state. [0044] An electrochemical process includes a process in which conductive elements are bonded to a voltage switchable dielectric material while the voltage switchable dielectric material is in the conductive state. An example of an electrochemical process is an electrolytic process. In an embodiment, an electrode is immersed in a fluid along with another material. A voltage is applied between the electrode and the other material to cause ions from the electrode to transfer and form on the other material. [0045] In one embodiment, a device includes a single-sided substrate formed from voltage switchable dielectric material. A non-conductive layer is patterned onto the substrate to define regions on the surface of substrate. Preferably, the substrate is subjected to an electrolytic process when the voltage switchable dielectric material is in a conductive state. The electrolytic process causes conductive material to incrementally form on the substrate in the regions defined by the pattern of the non-conductive layer. One advantage of this embodiment is that the current-carrying formation can be fabricated on the structure with a reduced thickness relative to previous substrate devices. Also, the patterned current-carrying formation can be formed without implementing some fabrication steps used with prior art structures, such as, for example, steps of etching, or multiple steps of masking, imaging, and developing resist layers. [0046] In another embodiment of the invention, a dual-sided substrate is formed to include vias to electrically connect components on both sides of the substrate. A patterned current-carrying layer is formed on each side of the substrate. One or more vias extend through the substrate. The substrate can be subjected to one or more electrochemical processes while in the conductive state, causing current-carrying material to be formed on selected sections of the substrate, including on surfaces defining the vias. The selected sections of the substrate can be defined by a non-conductive layer, patterned in a previous step. [0047] Several shortcomings exist in previous processes that plate or otherwise provide conductive layers to surfaces of vias. In previous processes that deposit seed layers on surfaces of vias and then subject those surfaces to an electroplating process, the plating material bonds only to the particles that comprise the seed layer. Seeding conductive particles can be problematic and costly, since it requires additional manufacturing steps. Further, the continuity and dispersion of the particles along surfaces defining the vias is often imperfect. As such, a substantial risk exists that the continuity of the plating is broken at some juncture of a surface of a via. [0048] Other previous processes use adhesives to form mechanical bonds between surfaces, or between particles in the surface of a via and a conductive material. The mechanical bonds are relatively weak in comparison to electrochemical bonds formed on surfaces of the substrate. The mechanical nature of the bonds formed between the surface of the via and the conductive material make devices prone to failure. To compound problems with previous devices, a failed plated via is detrimental to the entire substrate device. [0049] Typically, vias are plated only after the substrate is provided with conductive elements on the substrate's surfaces. Failures in the plated vias may not be noticed or caused until at least some or all of the substrates in the device are assembled together. If plating a via fails, re-plating the via is not feasible in the assembled device. Often, the entire device has to be discarded. Thus, one failed via in a device having several vias and substrates is enough to cause the entire device, including all of the fabricated substrates, to be discarded. [0050] Among other advantages of this embodiment, problematic methods for forming current-carrying formations on surfaces defining vias are avoided. According to prior art methods that require a surface modification to be conductive, additional materials are required to prepare vias to bond with a conductive material because the surfaces of the vias are not otherwise conductive without these materials. Thus, additional materials are not needed in embodiments of the invention because the voltage switchable dielectric material forming the substrate can be made conductive during the electroplating process. As such, bonds formed between surfaces of vias and the current-carrying material are electrical attraction bonds formed during the electrochemical process. The bond, herein referred to as an electrochemical bond, is stronger than bonds formed by seeded particles or adhesives. Moreover, the surfaces of the vias are uniformly surfaces of a voltage switchable dielectric material. Thus, electrical continuity through the vias is ensured. [0051] In another embodiment of the invention, a multi-substrate device includes two or more substrates each formed from a voltage switchable dielectric material. Each substrate can be subjected to an electrochemical process to form a conductive layer. A pattern of each conductive layer is predetermined by patterning a non-conductive layer to define the pattern for the current-carrying formation. One or more vias may be used to electrically connect current-carrying formations on one or more of the substrates. Each via may be formed when the respective substrates are subjected to the electrochemical process. [0052] Among other advantages provided by embodiments of the invention, multi-substrate devices use the conductive state of the voltage switchable dielectric material to plate vias interconnecting the different substrate surfaces. Therefore, current-carrying materials can be formed on vias during an electrolytic processes without having to alter the substrate in regions that define the vias. The resulting current-carrying layers formed in the vias significantly reduce the risk that the vias will fail to establish electrical contact between substrates. In contrast, prior art multi-substrate devices have been plagued by occasionally ineffective vias, which often resulted in the entire multi-substrate device having to be discarded. [0053] Another advantage provided to embodiments of the invention is that inclusion of a substrate formed from a voltage switchable dielectric material also provides voltage regulation protection to the device as a whole. Numerous applications for embodiments of the invention exist. Embodiments of the invention may be employed for use with, for example, substrate devices such as PCBs, surface mount components, pin connectors, smart cards, and magnetically layered materials. A. Single Substrate Devices [0054] FIG. 1 is a cross-sectional view of a device incorporating a voltage switchable dielectric material, under an embodiment of the invention. In this embodiment, the voltage switchable dielectric material is used to form a substrate 10 of the device. The voltage switchable dielectric material is non-conductive but, as previously noted, can be switched to a conductive state by applying a voltage having a magnitude that exceeds a characteristic voltage of the material. Numerous examples of a voltage switchable dielectric material have been developed, including those described below with reference to FIG. 2 . Applications in which current-carrying substrates are used include, for example, printed circuit boards (PCBs), printed wiring boards, semiconductor wafers, flex circuit boards, backplanes, and integrated circuit devices. Specific applications of integrated circuit include devices having computer processors, computer readable memory devices, motherboards, and PCBs. [0055] The voltage switchable dielectric material in the substrate 10 allows for the fabrication of a patterned current-carrying formation 30 . The current-carrying formation 30 is a combination of individual current-carrying elements 35 formed onto the substrate 10 according to a predetermined pattern. The current-carrying formation 30 includes conductive materials. The current-carrying formation 30 is formed from precursors deposited on the substrate 10 during an electrochemical process in which the voltage switchable dielectric material is rendered conductive by an applied voltage (see FIG. 2 ). In an embodiment, the precursors are ions deposited from an electrode into a solution. The substrate 10 is exposed to the solution while the voltage switchable dielectric material is maintained in the conductive state. [0056] The precursors selectively deposit on the substrate 10 according to a predetermined pattern. The predetermined pattern is formed by patterning a non-conductive layer 20 such as a resist layer (see FIGS. 3B-3D ). When the voltage switchable dielectric material is in the conductive state, the precursors deposit only on the exposed regions of the substrate 10 . The voltage switchable dielectric material in the conductive state can form electrochemical bonds with the precursors in the exposed sections of the substrate 10 . In an embodiment, the non-conductive layer 20 ( FIGS. 3B-3D ) is formed from a resist layer deposited over the substrate 10 . The resist layer is then masked and exposed to create the pattern, as is well known. [0057] FIG. 2 illustrates the resistive properties of voltage switchable dielectric materials as a function of applied voltage. The voltage switchable dielectric materials that can be used to form the substrate have a characteristic voltage value (Vc) specific to the type, concentration, and particle spacing of the material's formulation. A voltage (Va) can be applied to the voltage switchable dielectric material to alter the electrical resistance properties of the material. If the magnitude of Va ranges between 0 and Vc, the voltage switchable dielectric material has a high electrical resistance and is therefore non-conductive. If the magnitude of Va exceeds Vc, the voltage switchable dielectric material transforms into a low electrical resistance state in which it is conductive. As shown by FIG. 2 , the electrical resistance of the substrate preferably switches sharply from high to low, so that the transformation between states is immediate. [0058] In an embodiment, Vc ranges between 1 and 100 volts to render the voltage switchable dielectric material conductive. Preferably, Vc is between 5 and 50 volts, using one of the compositions for voltage switchable dielectric material listed below. In an embodiment, a voltage switchable material is formed from a mixture comprising conductive particles, filaments, or a powder dispersed in a layer including a non-conductive binding material and a binding agent. The conductive material may comprise the greatest proportion of the mixture. Other formulations that have the property of being non-conductive until a threshold voltage is applied are also intended to be included as voltage switchable dielectric material under embodiments of this invention. [0059] A specific example of a voltage switchable dielectric material is provided by a material formed from a 35% polymer binder, 0.5% cross linking agent, and 64.5% conductive powder. The polymer binder includes Silastic 35U silicone rubber, the cross-linking agent includes Varox peroxide, and the conductive powder includes nickel with a 10 micron average particle size. Another formulation for a voltage switchable material includes 35% polymer binder, 1.0% cross linking agent, and 64.0% conductive powder where the polymer binder, the cross-linking agent, and the conductive powder are as described above. [0060] Other examples of conductive particles, powders, or filaments for use in a voltage switchable dielectric material can include aluminum, beryllium, iron, silver, platinum, lead, tin, bronze, brass, copper, bismuth, cobalt, magnesium, molybdenum, palladium, tantalum carbide, boron carbide, and other conductive materials known in the art that can be dispersed within a material such as a binding agent. The non-conductive binding material can include organic polymers, ceramics, refractory materials, waxes, oils, and glasses, as well as other materials known in the art that are capable of inter-particle spacing or particle suspension. Examples of voltage switchable dielectric material are provided in references such as U.S. Pat. No. 4,977,357, U.S. Pat. No. 5,068,634, U.S. Pat. No. 5,099,380, U.S. Pat. No. 5,142,263, U.S. Pat. No. 5,189,387, U.S. Pat. No. 5,248,517, U.S. Pat. No. 5,807,509, WO 96/02924, and WO 97/26665, all of which are incorporated by reference herein. The present invention is intended to encompass modifications, derivatives, and changes to any of the references listed above or below. [0061] Another example of a voltage switchable dielectric material is provided in U.S. Pat. No. 3,685,026, incorporated by reference herein, which discloses finely divided conductive particles disposed in a resin material. Yet another example of voltage switchable dielectric material is provided in U.S. Pat. No. 4,726,991, incorporated by reference herein, which discloses a matrix of separate particles of conductive materials and separate particles of a semiconductor material coated with an insulative material. Other references have previously incorporated voltage switchable dielectric materials into existing devices, such as disclosed in U.S. Pat. No. 5,246,388 (connector) and U.S. Pat. No. 4,928,199 (circuit protection device), both of which are incorporated by reference herein. [0062] FIGS. 3A-3F illustrate a flow process for forming a single layer current-carrying structure on a substrate as shown in FIG. 1 , under an embodiment of the invention. The flow process exemplifies a process in which the electrical properties of a voltage switchable dielectric material are used to develop a current-carrying material according to a predetermined pattern. [0063] In FIG. 3A , a substrate 10 is provided that is formed from a voltage switchable dielectric material. The substrate 10 has dimensions, shape, composition and properties as necessary for a particular application. The composition of the voltage switchable dielectric material can be varied so that the substrate is rigid or flexible, as required by the application. In addition, the voltage switchable dielectric material can be shaped for a given application. While some embodiments described herein disclose essentially planar substrates, other embodiments of the invention may employ a voltage switchable dielectric material that is molded or shaped into a non-planar substrate, such as for use with connectors and semiconductor components. [0064] In FIG. 3B , a non-conductive layer 20 is deposited over the substrate 10 . The non-conductive layer 20 can be formed from a photo-imageable material, such as a photoresist layer. Preferably, the non-conductive layer 20 is formed from a dry film resist. FIG. 3C shows that the non-conductive layer 20 is patterned on the substrate 10 . In an embodiment, a mask is applied over the non-conductive layer 20 . The mask is used to expose a pattern of the substrate 10 through a positive photoresist. The pattern of the exposed substrate 10 corresponds to a pattern in which current-carrying elements will subsequently be formed on the substrate 10 . [0065] FIG. 3D shows that the substrate 10 subjected to an electrolytic process while the voltage switchable dielectric material is maintained in a conductive state. The electrolytic process forms a current-carrying formation 30 that includes current-carrying elements 35 . In an embodiment, the electroplating process deposits current-carrying elements 35 on the substrate 10 in gaps 14 in the non-conductive layer 20 created by masking and exposing the photoresist. Additional details of the electrolytic process as employed under an embodiment of the invention are described with FIG. 4 . [0066] In FIG. 3E , the non-conductive layer 20 is removed as necessary from the substrate 10 . In an embodiment in which the non-conductive layer 20 includes photoresist, the photoresist is stripped from the surface of the substrate 10 using a base solution, such as a potassium hydroxide (KOH) solution. Still, other embodiments may employ water to strip the resist layer. In FIG. 3F , the resulting conductive layer 30 patterned onto the substrate 10 is polished. An embodiment employs chemical-mechanical polishing (CMP) means. [0067] FIG. 4 details the development of current-carrying elements on the substrate by use of an electroplating process. In a step 210 , the electroplating process includes forming an electrolytic solution. The composition of the current-carrying elements depends on the composition of an electrode used to form the electrolytic solution. Accordingly, the composition of the electrode is selected according to factors such as cost, electrical resistance, and thermal properties. Depending on the application, for example, the electrode can be gold, silver, copper, tin, or aluminum. The electrode can be immersed in a solution including, for example, sulfate plating, pyrophosphate plating, and carbonate plating. [0068] In a step 220 , a voltage that exceeds the characteristic voltage of the voltage switchable dielectric material is applied to the substrate 10 while the substrate 10 is immersed in the electrolytic solution. The substrate 10 switches to a conductive state, such as is illustrated by FIG. 2 . The applied voltage makes the substrate 10 conductive, causing precursors in the electrolytic solution to bind to the voltage switchable dielectric material. [0069] In a step 230 , ions from the electrolytic solution bond to the substrate 10 in areas of the substrate 10 that are exposed by the non-conductive layer 20 . In an embodiment, ions are precluded from bonding to regions where the photoresist has been exposed and developed. Therefore, the pattern of conductive material formed on the substrate 10 matches the positive mask used to pattern the non-conductive layer 20 . Exposed regions of the substrate 10 attract and bond to the ions, in some embodiments, because the substrate is maintained at a voltage relative to the electrode so that the substrate, the electrode, and the electrolytic solution together comprise an electrolytic cell, as in well known. [0070] Among advantages provided by an embodiment of the invention, current-carrying elements 35 are patterned onto the substrate 10 in a process requiring fewer steps than prior art processes. For example, in an embodiment, current-carrying elements 35 are deposited to form circuitry on the substrate 10 without etching, and therefore also without deposition of a buffer or masking layer for an etching step. In addition, embodiments of the invention allow for the current-carrying elements 35 to be formed directly on the substrate 10 instead of on a seed layer. This allows a vertical thickness of the current-carrying elements 35 to be reduced relative to that in similar devices formed by other processes. B. Devices Having Dual-Sided Substrates [0071] Certain devices include substrates that employ electrical components on two or more sides. The number of current-carrying elements that can be retained on a single substrate increases when two sides are used. As such, dual-sided substrates are often used when a high-density distribution of components are desired. Dual-sided substrates include, for example, PCBs, printed wiring boards, semiconductor wafers, flex circuits, backplanes, and integrated circuit devices. In such devices, vias or sleeves are typically used to interconnect both planar sides of the substrate. The vias or sleeves establish an electrical connection between the current-carrying elements on each planar side of the substrate. [0072] FIG. 5 displays an embodiment in which a device includes a dual-sided substrate 310 having one or more plated vias 350 . The vias 350 extend from a first planar surface 312 of the substrate to a second planar surface 313 of the substrate. The first surface 312 includes a current-carrying formation 330 having a plurality of current-carrying elements 335 . The second surface 313 includes a current-carrying formation 340 having a plurality of current-carrying elements 345 . The current-carrying formations 330 , 340 are fabricated on the respective sides 312 , 313 of the substrate 310 by an electrochemical process. In an embodiment, an electrolytic process is used to form a solution of precursors that are deposited on the respective first or second surface of the substrate when a voltage switchable dielectric material is in a conductive state. The precursors deposit on the substrate 310 according to a pattern of a pre-existing non-conductive layer on the respective first or second surface 312 , 313 . [0073] In an embodiment, a via 350 is formed in the substrate 310 before the substrate is subjected to the electrolytic process. Each side 312 , 313 of the substrate 310 includes a patterned non-conductive layer (not shown). In an embodiment, the patterned non-conductive layers are photoresist layers that are patterned to expose select regions on the first and second side 312 , 313 of the substrate 310 . The via 350 is positioned so that a plated surface of the via 350 subsequently contacts one or more of the current-carrying elements 335 , 345 on the first and second side 312 , 313 . During the electrolytic process, the via 350 is plated while current-carrying formations 330 and 340 are fabricated. In this way the via 350 is provided with a conductive sleeve or side-wall 355 to extend an electrical connection from one of the current-carrying elements 335 on the first surface 312 with one of the current-carrying elements 345 on the second side 313 of the substrate 310 . [0074] FIG. 6 displays a flow process for developing a dual-sided substrate 310 , according to an embodiment of the invention. In a step 410 , the substrate 310 is formed from a voltage switchable dielectric material and provided with dimensions, shape, properties, and characteristics necessary for a desired application. In a step 420 , a non-conductive layer 320 is deposited over the first and second side 312 , 313 of the substrate 310 . In a step 430 , the non-conductive layer 320 is patterned on the first side 312 of the substrate 310 . Preferably, non-conductive material on at least the first side 312 of the substrate 310 is a photo-imageable material, such as a photoresist that is patterned using a positive mask. The positive mask allows select regions of the substrate 310 to be exposed through the non-conductive layer 320 . In a step 440 , the non-conductive layer 320 is patterned on the second side 313 of the substrate 310 . In an embodiment, the non-conductive layer 320 on the second side 313 of the substrate 310 is similarly also a photoresist that is subsequently masked and exposed to form another pattern. The resulting pattern exposes the substrate 310 through the photoresist layer. [0075] In a step 450 , one or more vias 350 are formed through the substrate 310 . On each side 312 , 313 of the substrate 310 , the vias 350 intersect an uncovered portion of the substrate 310 . The vias 350 are defined by side-walls formed through the substrate 310 . In a step 460 , the substrate 310 is subjected to one or more electrolytic processes to plate the first side 312 , second side 313 , and the side-walls of the vias 350 . In an embodiment, in step 460 the substrate 310 is subjected to a single electrolytic process while an external voltage is applied to the voltage switchable dielectric material so that the substrate is in a conductive state. The conductive state of the substrate 310 causes ions in the electrolytic solution to bond to the substrate 310 in uncovered regions on the first and second surfaces 312 , 313 . The electrolytic fluid also moves through the vias 350 so that ions bond to the side-walls of the vias 350 , forming conductive sleeves 355 that extend through the vias 350 . The vias 350 intersect current-carrying elements on the first and second sides 312 , 313 to electrically connect the current-carrying formation 330 on the first side 312 with the current-carrying formation 340 on the second side 313 . [0076] The non-conductive layer 320 is removed as necessary from the substrate in a step 470 . In an embodiment in which the non-conductive layer 320 includes photoresist, the photoresist is stripped from the surface of the substrate 310 using a base solution, such as a KOH solution. In a step 480 , the resulting current-carrying formation 330 and/or 340 is polished. In an embodiment, CMP is employed to polish the current-carrying formation 330 . [0077] Several variations can be made to the embodiment described with reference to FIGS. 5 and 6 . In one variation, a first non-conductive layer can be deposited on the first surface 312 , and a second non-conductive layer can be deposited on the second surface 313 in a separate step. The first and second non-conductive layers can be formed from different materials, and can provide different functions other than enabling patterns to be formed for plating the substrate. For example, the first non-conductive material can be formed from a dry resist, while the second non-conductive material can be formed from a photo-imageable insulative material. While the dry resist is stripped away after a current-carrying layer is formed on the first side 312 , the photo-imageable insulative material is permanent and retained on the second surface 313 . [0078] Additionally, different plating processes can be used to plate the first surface 312 , the second surface 313 , and the surface 355 of the vias 350 . For example, the second surface 313 of the substrate 310 can be plated in a separate step from the first surface 312 to allow the first and second surfaces 312 , 313 to be plated using different electrodes and/or electrolytic solutions. Since embodiments of the invention reduce steps necessary to form current-carrying layers, forming current-carrying layers 330 and 340 on the dual-sided substrate 310 is particularly advantageous. The use of different plating processes facilitates the fabrication of different materials for the current-carrying formations on opposite sides of the substrate 310 . Different types of current-carrying material can be provided as simply as switching the electrolytic baths to include different precursors. [0079] As one example, a first side of a device such as a PCB is intended to be exposed to the environment, but the opposite side requires a high-grade conductor. In this example, a nickel pattern can be plated on the first side of the substrate, and a gold pattern can be plated on the second side of the substrate. This enables the PCB to have a more durable current-carrying material on the exposed side of the PCB. [0080] Any number of vias can be drilled, etched, or otherwise formed into the substrate. Vias can interconnect current-carrying elements, including electrical components or circuitry. Alternatively, a via can be used to ground a current-carrying element on one side of the substrate to a grounding element accessible from a second side of the substrate. [0081] Among advantages included with dual-sided substrates under an embodiment of the invention, precursors from the electrode form an electrochemical bond to the surfaces of the vias 350 . The vias 350 are therefore securely plated, with minimal risks of a discontinuity that would interrupt electrical connection between the two sides of the substrate 310 . C. Devices Having Multi-Layered Substrates [0082] Some devices may include two or more substrates into one device. Stacking substrates enables the device to incorporate a high density of current-carrying elements, such as circuitry and electrical components, within a limited footprint. FIG. 7 illustrates a multi-substrate device 700 . In the embodiment shown, the device 700 includes first, second and third substrates 710 , 810 , 910 . Each substrate 710 - 910 is formed from a voltage switchable dielectric material. As with previous embodiments, the substrates 710 - 910 are non-conductive absent an applied voltage that exceeds the characteristic voltage of the voltage switchable dielectric material. While FIG. 7 illustrates an embodiment of three substrates, other embodiments may include more or fewer substrates. It will be appreciated that substrates may also be aligned in different configurations other than being stacked, such as adjacent or orthanormal to one another. [0083] Each substrate 710 , 810 , 910 is provided with at least one current-carrying formation 730 , 830 , 930 respectively. Each current-carrying formation 730 , 830 , 930 is formed from a plurality of current-carrying elements 735 , 835 , 935 respectively. The current-carrying elements 735 , 835 , 935 are each formed when their respective substrates 710 , 810 , 910 are subjected to an electrochemical process while in a conductive state. Preferably, the substrates 710 , 810 , 910 are mounted on one another after the respective current-carrying layers 735 , 835 , 935 are formed. [0084] The device 700 includes a first plated via 750 to electrically connect current-carrying elements 735 on the first substrate 710 to current-carrying elements 935 on the third substrate 910 . The device 700 also includes a second plated via 850 to electrically connect current-carrying elements 835 on the second substrate 810 with current-carrying elements 935 on the third substrate 910 . In this way, the current-carrying formations 730 , 830 , 930 of the device 700 are electrically interconnected. The arrangement of plated vias 750 , 850 shown in the device 700 is only exemplary, as more or less vias can also be employed. [0085] For example, additional vias can be used to connect one of the current-carrying elements 735 , 835 , 935 to any other of the current-carrying elements on another substrate. Preferably, the first and second plated vias 750 , 850 are formed in the substrates 710 , 810 , 910 before the substrates 710 , 810 , 910 are individually plated. Thus, prior to plating, the plated vias 750 , 850 are formed through the substrates 710 , 810 , 910 in predetermined positions so as to connect the current-carrying elements 735 , 835 , 935 of the different substrates as necessary. For the first plated via 750 , openings are formed in the substrates 710 , 810 , 910 at the predetermined positions before any of the substrates are plated Likewise, for the second plated via 850 , openings are formed in the substrates 810 , 910 at predetermined positions prior to those substrates being plated. The predetermined positions for the first and second plated via 750 and 850 correspond to uncovered regions on surfaces of the respective substrates in which current-carrying material will form. During subsequent electrolytic processes, precursors deposit in these uncovered regions of the substrates, as well as within the openings formed in each substrate to accommodate the vias 750 , 850 . [0086] For simplicity, details of device 700 will be described with reference to the first substrate 710 . The first substrate 710 includes gaps 714 between the current-carrying elements 735 . In an embodiment, gaps 714 are formed by masking a photoresist layer and then removing remaining photoresist after the current-carrying elements 735 are fabricated on the substrate 710 . Similar processes are used to form second and third substrates 810 , 910 . The first substrate 710 is mounted over the current-carrying formation 830 of the second substrate 810 . As with the first substrate 710 , the second substrate 810 is mounted directly over the current-carrying formation 930 of the third substrate 910 . [0087] In a variation to embodiments described above, one or more substrates in the device 700 may be dual-sided. For example, the third substrate 910 may be dual-sided, since the location of the third substrate 910 at the bottom of the device 700 readily enables the third substrate to incorporate a double-sided construction. Therefore, the device 700 may include more current-carrying formations than substrates to maximize the density of componentry and/or minimize the overall footprint of the device. [0088] The composition of the substrates 710 , 810 , 910 , as well as the particular current-carrying material used for each substrate, may vary from substrate to substrate. Thus, for example, the current-carrying formation of the first substrate 710 maybe formed from nickel, while the current-carrying formation 830 of the second substrate 810 is formed from gold. [0089] FIG. 8 illustrates a flow process for developing a device having multi-layered substrates, such as the device 700 , where two or more of the substrates are formed from a voltage switchable dielectric material. The device can be formed from a combination of single and/or double-sided substrates. In an embodiment, the multi-substrate device 700 comprises separately formed substrates having current-carrying formations. With reference to device 700 , in a step 610 , the first substrate 710 is formed from a voltage switchable dielectric material. In a step 620 , a first non-conductive layer is deposited over the first substrate 710 . As with previously described embodiments, the first non-conductive layer can be, for example, a photo-imageable material such as a photoresist layer. In a step 630 , the first non-conductive layer is patterned to form selected regions in which the substrate 710 is exposed. In an embodiment, a photoresist layer is masked and then exposed to form the pattern, so that the substrate is exposed according to the pattern of the positive mask. [0090] In a step 640 , the first via 750 is formed in the substrate 710 . The first via 750 is preferably formed by etching a hole in the substrate 710 . Additional vias can be formed as needed in the substrate 710 . The via 750 is etched in a location on the substrate that is predetermined to be where select current-carrying elements 735 will be located to connect to current-carrying elements of other substrates in the device 700 . In a step 650 , the first substrate 710 is subjected to an electrolytic process. The electrolytic process employs an electrode and a solution according to design requirements for the first substrate 710 . Components of the electrolytic process, including the electrode and the composition of the electrolytic solution, are selected to provide the desired precursors, i.e. materials forming the conductive layer 730 . In a step 660 , the remaining non-conductive layer on the first substrate 710 is removed. The current-carrying elements 735 on the first substrate 710 are then polished in a step 670 , preferably using CMP. [0091] Once the first substrate 710 is formed, additional substrates 810 , 910 can be formed in step 680 to complete the multi-substrate device 700 . Subsequent substrates 810 , 910 are formed using a combination of the steps 610 - 670 . One or more additional vias, such as the second via 850 , may be formed into another substrate as described according to steps 640 and 650 . The device 700 may include additional substrates formed as described in steps 610 - 680 , or as described for double-sided substrates above. [0092] Variations may be made to each of the substrates 710 , 810 as needed. For example, one or more substrates used in the device can have a voltage switchable dielectric material with a different composition. Accordingly, the external voltage applied to each substrate to overcome the characteristic voltage can therefore vary between substrates. Materials used for the non-conductive layers can also be varied from substrate to substrate. Additionally, the non-conductive layers can be patterned with, for example, different masking, imaging, and/or resist development techniques. Further, the materials used to develop current-carrying elements on the surfaces of the substrates can also be varied from substrate to substrate. For instance, the electrodes used to plate each substrate can be altered or changed for the different substrates, depending on the particular design parameters for the substrates. [0093] Under a variation, it can be preferable for the process to include for at least one double-sided substrate, such as at an end of the stack of substrates. The third substrate 910 , for example, can be formed to include current-carrying elements 935 on both planar sides. In this variation, a non-conductive layer is deposited on the first side and the second side of the third substrate 910 . The non-conductive layer on the second side can be made of the same material as the first side, although in some applications the second side of the substrate may require a different type of photo-imageable material or other non-conductive surface. The non-conductive layers on each side of the third substrate 910 are then individually patterned. The third substrate 910 is uncovered on the first and second sides when the respective non-conductive layers are patterned. Exposed regions on each side of the substrate may be plated together or in separate plating steps. [0094] Embodiments, such as shown, above can be used in PCB devices. PCBs have a variety of sizes and applications, such as for example, for use as printed wiring boards, motherboards, and printed circuit cards. In general, a high density of current-carrying elements, such as electrical components, leads, and circuitry, are embedded or otherwise included with PCBs. In multi-substrate devices, the size and function of the PCBs can be varied. A device including a PCB under an embodiment of the invention has a substrate formed from voltage switchable dielectric material. A photoresist such as a dry film resist can be applied over the substrate. An example of a commercially available dry film resist includes Dialon FRA305, manufactured by Mitsubishi Rayon Co. The thickness of the dry film resist deposited on the substrate is sufficient to allow the substrate to become exposed at selected portions corresponding to where the resist was exposed by the mask. [0095] An electroplating process such as described with respect to FIG. 3 is used to plate conductive materials on exposed regions of the substrate. Substrates formed from a voltage switchable dielectric material can be used for various applications. The voltage switchable dielectric material can be formed, shaped, and sized as needed for the various printed circuit board applications. Examples of printed circuit boards include, for example, (i) motherboards for mounting and interconnecting computer components; (ii) printed wiring boards; and (iii) personal computer (PC) cards and similar devices. Still other applications are provided below. D. Alternative Embodiments [0096] The following are some examples of variations to one or more of the embodiments described above. 1. Pulse Plating Process [0097] An embodiment of the invention employs a pulse plating process. In this process, an electrode and a substrate comprising a voltage switchable dielectric material are immersed in an electrolytic solution. A voltage is applied between the electrode and the substrate so that the voltage switchable dielectric material becomes conductive. The applied voltage also causes ions in the electrolytic solution to deposit onto exposed areas of the substrate, thereby plating a current-carrying formation. In the pulse plating process, the voltage is modulated and follows a waveform such as the exemplary waveform 900 shown in FIG. 9 . The waveform 900 resembles a square-wave, but further includes a leading edge spike 910 . The leading edge spike 910 is preferably a very short duration voltage spike sufficient to overcome a trigger voltage, V t , of the voltage switchable dielectric material, where the trigger voltage is a threshold voltage that must be exceeded in order for the voltage switchable dielectric material to enter the conductive state. In some embodiments, the trigger voltage is relatively large, such as between 100 and 400 volts. [0098] Once the trigger voltage has been exceeded and the voltage switchable dielectric material is in the conductive state, the voltage switchable dielectric material will remain in the conductive state for as long as the voltage applied to the voltage switchable dielectric material remains above a lower clamping voltage, V c . In the waveform 900 of FIG. 9 , it will be appreciated that the leading edge spike 910 is followed by a plateau 920 at a voltage above the clamping voltage. The plateau 920 is followed by a relaxation period in which the voltage returns to a baseline 930 , such as 0 volts, then the cycle repeats. 2. Reverse Pulse Plating Process [0099] Another embodiment of the invention employs a reverse pulse plating process. This process is essentially the same as the pulse plating process described above, except that in place of the plateau 920 ( FIG. 9 ) the polarity of the voltage is reversed so that plating occurs at the electrode instead of the substrate. An exemplary waveform 1000 is shown in FIG. 10 in which the positive and negative portions have essentially the same magnitude but opposite polarity. The shape of the negative portion need not match that of the positive portion in either magnitude or duration, and in some embodiments the negative portion of the waveform 1000 does not include a leading edge voltage spike. An advantage to reverse pulse plating is that it produces smoother plating results. When the voltage reverse, those areas on the plating surface where plating occurred most rapidly before the reversal become those areas where dissolution occurs most readily. Accordingly, irregularities in the plating tend to smooth out over time. 3. Depositing and Patterning Non-Conductive Layers [0100] Another embodiment of the invention employs a silk-screening method to develop a patterned non-conductive layer on a substrate comprised of a voltage switchable dielectric material. This embodiment avoids the use of materials such as photoresist to develop the pattern for depositing current-carrying materials on the substrate. In a silk screening process, a robotic dispenser applies a dielectric material to the surface of the substrate according to a preprogrammed pattern. The silkscreen liquid applicant is typically a form of plastic or resin, such as Kapton. In contrast to other embodiments using photoresist materials for the non-conductive layer, silk-screened Kapton, or another plastic or resin, is permanent to the surface of the substrate. As such, silk-screening offers advantages of combining steps for depositing and patterning non-conductive material on the substrate, as well as eliminating steps for removing non-conductive material from the surface of the substrate. 4. Multiple Types of Conductive Materials on a Single Surface [0101] In addition, current-carrying elements may be fabricated onto a surface of a substrate from two or more types of current-carrying materials. The substrate including the voltage switchable dielectric material is adaptable to be plated by several kinds of current-carrying materials. For example, two or more electrolytic processes can be applied to a surface of the substrate to develop different types of current-carrying particles. In one embodiment, a first electrolytic process is employed to deposit a first conductive material in a first pattern formed on the surface of the substrate. Subsequently, a second non-conductive layer is patterned on the substrate including the first conductive material. A second electrolytic process may then be employed to deposit a second conductive material using the second pattern. In this way, a substrate may include multiple types of conductive material. For example, copper can be deposited to form leads on the substrate and another conductive material, such as gold, can be deposited elsewhere on the same surface where superior conduction is necessary. E. Other Applications for Embodiments of the Invention [0102] Embodiments of the invention include various devices comprising a substrate of a voltage switchable dielectric material upon which a current-carrying formation has been deposited. The current-carrying formation can comprise circuits, leads, electrical components, and magnetic material. Exemplary applications for embodiments of the invention are described or listed below. The applications described or listed herein are merely illustrative of the diversity and flexibility of this invention, and should therefore not be construed as an exhaustive list. 1. Pin Connectors [0103] In an embodiment, a pin connector is provided. For example, the voltage switchable dielectric material is used to form an interior structure of a female pin connector. The voltage switchable dielectric material can be used to form contact leads within the interior structure of the female pin connector. The voltage switchable dielectric material may be shaped into the interior structure using, for example, a mold that receives the voltage switchable dielectric material in a liquid form. The resulting interior structure includes a mating surface that opposes the male pin connector when the two connectors are mated. A plurality of pin receptacles are accessible though holes in the mating surface. The holes and pin receptacles correspond to where pins from the male connector will be received. [0104] To provide conductive contact elements within the connector, and as shown in FIG. 11 , the interior structure may be separated into segments 1100 to expose the lengths of the pin receptacles 1110 that extend to the holes in the mating surface 1120 . A non-conductive layer 1200 , shown in FIG. 12 , such as a photoresist layer may be deposited on one of the segments 1100 . The non-conductive layer 1200 may then be patterned so that a bottom surface 1210 of each pin receptacle 1110 is exposed through the non-conductive layer 1200 . One or both segments 1100 of the interior structure may then be subjected to an electrolytic plating process. During the plating process, a voltage is applied to the interior structure so that the voltage switchable dielectric material is conductive. A conductive material is then plated on the bottom surface 1210 of each pin receptacle 1110 in the interior structure. Once the contact leads are formed in the pin receptacles 1110 , the non-conductive layer 1200 can be removed and the segments 1100 rejoined. The interior structure may also be housed within a shell to complete the female pin connector. [0105] Several advantages exist to forming a pin connector under an embodiment of the invention. Plating the interior structure enables a large number of pin receptacles to be included in the interior structure in one plating process. Further, because the lead contacts can be made thinner, pin receptacles can be formed closer together to reduce dimensions of the pin connector. The pin connector can also provide over-voltage protection properties that are inherent to voltage switchable dielectric materials. 2. Surface Mount Packages [0106] Surface mount packages mount electronic components to a surface of a printed circuit board. Surface mount packages house, for example, resistors, capacitors, diodes, transistors, and integrated circuit devices (processors, DRAM etc.). The packages include leads directed internally or outwardly to connect to the electrical component being housed. Specific examples of surface mounted semiconductor packages include small outline packages, quad flat packages, plastic leaded chip carriers, and chip carrier sockets. [0107] Manufacturing surface mount packages involves forming a frame for the leads of the package. The frame is molded using a material such as epoxy resin. Thereafter, leads are electroplated into the molded frame. In an embodiment of the invention, a voltage switchable dielectric material can be used to form the frame. A non-conductive layer is formed on the frame to define the locations of the leads. The non-conductive layer can be formed during the molding process, during a subsequent molding process, or through a masking process using a photo-imageable material such as described above with respect to previous embodiments. A voltage is applied to the frame during the electroplating process to rendering the frame conductive. The leads form on the frame in locations defined by a pattern of the non-conductive layer. [0108] By using a voltage switchable dielectric material, leads can be made thinner or smaller, allowing for a smaller package that occupies a smaller footprint on the PCB. The voltage switchable dielectric material also inherently provides over-voltage protection to protect contents of the package from voltage spikes. 3. Micro-Circuit Board Applications [0109] Embodiments of the invention also provide micro-circuit board applications. For example, smart cards are credit-card size substrate devices having one or more embedded computer chips. A smart card typically includes a mounted micro-memory module and conductors for interconnecting the micro-memory module with other components such as a sensor for detecting smart card readers. Due to the size of the smart card, as well as the size of the components embedded or mounted to the smart card, conductive elements on the substrate of the smart card also have to be very small. [0110] In an embodiment, a voltage switchable dielectric material is used for the substrate of a smart card. An electrolytic plating process such as described above is used to produce a pattern of connectors on the smart card to connect the memory module to other components. A conductive layer comprising the pattern of connectors is plated onto the surface of the substrate through a photoresist mask as described above. By using a voltage switchable dielectric material, the pattern of connectors can be plated onto the substrate without having to etch. This can reduce the thickness of the conductive layer on the substrate. [0111] Another micro-circuit board application includes a circuit board that packages two or more processors together. The circuit board includes leads and circuits that enable high-level communications between the several processors mounted on the board so that the processors act substantially as one processing unit. Additional components such as a memory can also be mounted to the circuit board to communicate with the processors. Fine circuitry and lead patterns are therefore required to preserve processing speed for communications that pass between two or more processors. [0112] As with previous embodiments, such as the embodiments directed to smart cards, the micro-circuit board also includes a substrate formed from a voltage switchable dielectric material. A fine resist layer is patterned onto the substrate to define a pattern for selected regions of conductive material to be subsequently deposited. An electrolytic process is used to plate conductive material in selected regions according to a pattern to interconnect processors subsequently mounted to the circuit board. [0113] Again, one advantage provided by using voltage switchable dielectric materials is that conductive layers can be made with reduced thicknesses. Another advantage is that plating conductive material with fewer fabrication steps reduces manufacturing costs for the micro-circuit board. Still another advantage is that a micro-circuit board can be developed to have conductive elements formed from more than one type of conductive material. This is particularly advantageous for interconnecting processors on one micro-circuit board because material requirements of the conductors may vary for each processor, depending on the quality, function, or position of each processor. For example, processors of the micro-circuit board that are exposed to the environment may require more durable conductive elements, for example made from nickel, to withstand temperature fluctuations and extremes. Whereas a processor for handling more computationally demanding functions, and located away from the environment, can have contacts and leads formed from a material with a higher electrical conductivity such as gold or silver. 4. Magnetic Memory Device [0114] In another application, a substrate is integrated into a memory device that includes a plurality of memory cells. Each memory cell includes a layer of a magnetic material. The orientation of a magnetic field of the layer of the magnetic material stores a data bit. The memory cells are accessed by electrical leads. Voltages applied to the memory cells via the electrical leads are used to set and to read the orientations of magnetic fields. Transistors mounted to, or formed in, the substrate are used to select the memory cells to be set and to be read. [0115] In an embodiment of the invention, the substrate used in the memory device is formed from a voltage switchable dielectric material. A first non-conductive layer is deposited and patterned on the substrate to define regions where the layer of magnetic material is to be fabricated. A first electrolytic process, as described above, is used to plate the layer of magnetic material on the substrate. The electrolytic process, for example, can be used to plate a cobalt-chromium (CoCr) film as the layer of magnetic material. Similarly, a second non-conductive layer may be deposited and masked on the substrate to define regions where the electrical leads are to be located. A second electrolytic process is then used to plate the electrical leads. 5. Stacked Memory Devices [0116] Under still another embodiment, a multi-substrate memory device includes a plurality of substrates each formed from a voltage switchable dielectric material. The substrates are stacked and are electrically interconnected using one or more vias. As shown by FIGS. 5 and 7 , the vias are plated with a current-carrying layer by an electrolytic process. Several advantages are apparent under this embodiment of the invention. The vias can be plated during a fabrication step with one or more of the current-carrying formations formed on the surface of the respective substrates. The plating on the surface of the vias is also less expensive to produce and more reliable than plated vias produced by previous methods, such as by seeding the surfaces of the vias or using adhesives. 6. Flex Circuit Board Devices [0117] Yet another embodiment of the invention provides flex circuit board devices. Flex circuit boards generally include a high density of electrical leads and components. Unfortunately, increasing the density of electrical and conductive elements can diminish the speed and/or capacity of the flex circuit board. Embodiments of the invention provide a flex circuit board that advantageously uses a voltage switchable dielectric material to increase the density of electrical and conductive components on the flex circuit board. [0118] Under an embodiment, a composition of a voltage switchable dielectric material is selected and molded into a flexible and thin circuit board. A resist layer is patterned onto the substrate to define finely spaced regions, as above. A voltage exceeding the characteristic voltage of the particular voltage switchable dielectric material is applied to the voltage switchable dielectric material and a current-carrying formation is plated to form leads and contacts in the finely spaced regions. [0119] By using a voltage switchable dielectric material, current-carrying precursors are deposited directly on the surface of the substrate to form the current-carrying formation. This allows the current-carrying formation to have a reduced thickness in comparison to previous flex circuit board devices. Accordingly, the respective electrical and conductive elements on the surface of the flex circuit board can be thinner and spaced more closely together. An application for a flex circuit board under an embodiment of the invention includes a print head for an ink jet style printer. Thus, the use of a voltage switchable dielectric material enables the flex circuit board to have more finely spaced electrical components and leads resulting in increases printing resolution from the print head. 7. Radio Frequency ID (RFID) Tags [0120] Yet another embodiment of the invention provides RFID tags. In these embodiments the method of the invention can also be used to fabricate antennas and other circuitry on substrates for RFID and wireless chip applications. Additionally, a layer of a voltage switchable dielectric material can be used as an encapsulant. CONCLUSION [0121] In the foregoing specification, the invention is described with reference to specific embodiments thereof, but those skilled in the art will recognize that the invention is not limited thereto. Various features and aspects of the above-described invention may be used individually or jointly. Further, the invention can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive. It will be recognized that the terms “comprising,” “including,” and “having,” as used herein, are specifically intended to be read as open-ended terms of art.

A method includes providing a voltage switchable dielectric material having a characteristic voltage, exposing the voltage switchable dielectric material to a source of ions associated with an electrically conductive material, and creating a voltage difference between the source and the voltage switchable dielectric material that is greater than the characteristic voltage. Electrical current is allowed to flow from the voltage switchable dielectric material, and the electrically conductive material is deposited on the voltage switchable dielectric material. A body comprises a voltage switchable dielectric material and a conductive material deposited on the voltage switchable dielectric material using an electrochemical process. In some cases, the conductive material is deposited using electroplating.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to provisional application 61/223,360, filed Jul. 6, 2009 and that provisional application is incorporated by reference herein. BACKGROUND [0002] This relates generally to wireless networks and, particularly, to wireless networks using WiMAX technology. [0003] In wireless networks, including those compliant with the WiMAX standard, a femtocell may be utilized. Generally, a femtocell is a cell contained within a user's home. The user may use the femtocell to connect a variety of devices using short range wireless technology. Then the femtocell is linked through a broadband access network, such as a cable or DSL network to a server. [0004] Generally, a femtocell may be set up by a user, to some degree, independently of a network operator or service provider. For example, the broadband service provider has no idea that the signals that it is receiving are fed through a femtocell. It simply knows there is a connection for broadband access. BRIEF DESCRIPTION OF THE DRAWINGS [0005] FIG. 1 is an architecture depiction of one embodiment; [0006] FIG. 2 is a sequence chart for one embodiment; and [0007] FIG. 3 is a flow chart for one embodiment. DETAILED DESCRIPTION [0008] A femtocell may be a small wireless cell using a low power, short range connection within a user's home. For example, the connection may be by Bluetooth short range wireless link. The connection links to a gateway which, in turn, couples to a broadband network, such as a cable or digital subscriber link (DSL) network. Within the femtocell, an access point serves as the contact point for all of the stations within the femtocell. These stations, for example, may be a laptop computer, a printer, or a cell phone, to mention some examples. [0009] Referring to FIG. 1 , a wireless network 10 may include a femtocell 16 within a user's home. Various items may communicate within the femtocell, such as a cell phone 84 or a laptop computer 86 , using a short range wireless protocol. The femtocell may also communicate with a home or femto gateway (GW) 42 , adapted to operate with a DSL or cable connection 88 . The femtocell 16 may be part of a macro-cell 20 , including a base station 22 . [0010] The connection 42 connects the femtocell 16 to a mobile network service provider's (NSP's) network 18 . A bootstrap server 50 initializes the femtocell on the operator's network. [0011] The femtocell access point 52 may include a controller 92 coupled to a non-volatile memory 94 . A volatile memory 95 may be a static random access memory (SRAM) in one embodiment. A radio frequency transceiver 96 may provide wireless signals for proximate devices. The memory 94 may be a flash memory in one embodiment. An Ethernet physical layer 98 connects the controller 92 to the femto gateway 42 . [0012] In a software implemented embodiment, the memory 94 may store instructions executed by the controller 92 . However, other storage/controller combinations may also be used. [0013] A femto access service network (ASN) 14 may include a Self Organization Network (SON) server 38 and a security gateway (SeGW) 40 . Location servers 39 on the ASN 14 may be used for global positioning. [0014] The femtocell may be initiated by the user without network involvement. The signals from the femtocell nodes and access point may be fed over the broadband service network without knowledge of the existence of the femtocell by any service provider. Thus, the location of the femtocell in a WiMAX (IEEE Std. 802.16-2004, IEEE Standard for Local and Metropolitan Area Networks, Part 16: Interface for Fixed Broadband Wireless Access Systems, IEEE New York, N.Y. 10016) or WiFi (IEEE Std. 802.11 (1999-07-015) Wireless LAN Medium Access Control (MAC) and Physical Layer Specifications) network is initially unknown. It is desired to locate the femtocell in order to locate the correct security gateway for the femtocell to connect to. [0015] It is also desirable to know the location of the cell to authorize the femtocell in the network before the femtocell can begin its radio frequency transmissions. This is a regulatory requirement in the United States and many other countries. The location of mobile stations attached to the femtocells also needs to be identified in the operator's network 18 . The location of these mobile devices is needed for location based services and emergency calling for users in a femtocell deployment. For example, the user of a cell phone in a femtocell may assume that emergency services are provided. But when the connection is made over the short range wireless connection and through the broadband connection, the emergency services would not be readily accessible. [0016] Thus, to summarize, there are at least two scenarios in which the location of the femtocell or its constituents may be needed. The location of the femtocell is needed to locate the correct security gateway (SeGW) 40 for the femtocell to connect to during the initialization of the femtocell. This information needs to be provided to a bootstrap server 50 that bootstraps the initialization of the femtocell. In addition, the location of the femtocell on the network is needed before the femtocell can begin radio frequency transmissions for regulatory reasons. [0017] For the first scenario, an access point in the femtocell may provides its Internet Protocol address to a bootstrap server 50 . The bootstrap server can then do a rough location calculation based on the Internet Protocol address and provide the address for the security gateway 40 with the Internet Protocol address to which the femtocell can connect. [0018] The access point may provide information to the Self-Organization Network (SON) server 38 , including its public Internet Protocol address. Then the SON server can use the public Internet Protocol (IP) address to contact the backhaul service provider, such as the cable or DSL provider for the civic location information. The civic location is the subscriber's street name or locality. [0019] In addition, it may be possible to get global positioning system (GPS) information if available on the access point and coverage is available. Often global positioning system information does not work indoors and femtocells are often deployed indoors. However, if the global positioning system information is available, the SON server can accurately locate the femtocell to the order of tens of meters. [0020] In addition, a neighbor WiMAX macro-cell and/or femtocell base station may be determined by an access point scanning procedure, such as base station identifier (BSID), received signal strength indicator (RSSI), and the relative delay of two nearby base stations. If the BSID of a neighbor femtocell is provided by the current femtocell, this means that the SON server has authorized the transmission of the neighbor femtocell and, hence, the SON server knows the location of the neighbor femtocell. The SON server can use this as the approximate location of the current femtocell as well. Then the SON server can talk to the WiMAX location server to determine the location of the femtocell when the femtocell provides the neighbor WiMAX macro-cell information, such as BSID, RSSI, and relative delay. [0021] If WiFi/3G/2G information is present on the access point and there is coverage, the WiFi information may provide useful location information, for example, via LOKI, available from Skyhook Wireless, Inc., Boston, Mass. 02210, USA. The SON server needs to talk to the location servers of these other technologies. [0022] If nothing else works, then it may be necessary to manually intervene. This may be triggered by the SON server to the physical operations center. The user may be asked to provide and verify his or her current civic location, such as a zip code, street address, etc. via web interface or phone call. [0023] Thus, referring to FIG. 2 , at 31 , the IP address information, GPS information, WiMAX cell information, or 3G/2G WiFi cell information, as available may be forwarded by an access point to the SON server. Then, at 32 , the SON server can implement a civic location check with the backhaul location server. At 33 , a location check may be implemented based on the WiMAX cell information between the SON server and the WiMAX location server. At 34 , a location check may be based on the 3G/2G/WiFi cell information between the SON server and other technical location servers 39 . [0024] At 35 , a location check is done based on GPS information. At 36 , a check determines if the access point location is available with reasonable accuracy. If not, then the flow proceeds to step 37 . Otherwise, the flow proceeds to step 41 . At step 41 , the SON server authorizes a femtocell for RF transmission based on its location. At 37 , manual intervention is triggered. [0025] Referring to FIG. 3 , the sequence 60 may be implemented in software, hardware, or firmware. In a software embodiment, it may implemented by a computer readable medium storing instructions executed by a controller. The computer readable medium may be any semiconductor, optical, or magnetic storage medium. The instructions to implement the sequence 60 may be stored on one or more of the SON server 38 , the backhaul server 39 , and the location server 39 , in one embodiment. [0026] Initially, information to devine the location of the femtocell is obtained from a femtocell access point, as indicated in block 62 . The information is used to obtain location information from servers for that femtocell, as indicated in block 64 . If this information proves to be successful, as determined in diamond 66 , the security gateway address so obtained is sent to the access point in block 68 . Otherwise, in block 70 , manual intervention is tried. [0027] Since the femtocell is expected to be small or at close range, the simplest approximation for the location of a user in a femtocell is the location of the femtocell itself. Further enhancements can be made based on GPS or WiMAX signal strength measurements as needed. [0028] References throughout this specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation encompassed within the present invention. Thus, appearances of the phrase “one embodiment” or “in an embodiment” are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be instituted in other suitable forms other than the particular embodiment illustrated and all such forms may be encompassed within the claims of the present application. [0029] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

A server may automatically attempt to locate a femtocell. Information may be obtained from the femtocell or neighboring femtocells to determine location. Servers associated with the femtocell may be contacted using that information to determine the femtocells location.

BACKGROUND OF THE INVENTION To increase the power of internal combustion engines, exhaust gas turbochargers are used. Due to the large operating range of internal combustion engines in passenger vehicles, the exhaust gas turbocharger must be regulated in order to achieve a set boost pressure. To this end, in a multistage supercharging system (i.e., one with exhaust gas turbochargers connected in series), the fresh air is compressed first in a low-pressure compressor of a first exhaust gas turbocharger and then in a high-pressure compressor of a second exhaust gas turbocharger. When large volumes of fresh air are present, the choke limit of the high-pressure compressor is exceeded. To keep the high-pressure compressor from functioning as a choke in this case, some of the fresh air can be diverted around the high-pressure compressor through a compressor bypass. When the volume of fresh air is below the choke limit of the high-pressure compressor, the compressor bypass is closed. To keep the pressure build-up in the exhaust gas turbocharger from not lagging when the temperature of the exhaust gas is low and the volume of exhaust gas is very small, as is the case at low rpm, exhaust gas turbochargers of the kind currently used in internal combustion engines have a very low intrinsic mass and therefore respond even at low exhaust flow rates. The power limits of the exhaust gas turbocharger can be broadened for example by regulated two-stage supercharging, as known from Bosch, Kraftfahrttechnisches Taschenbuch [Automotive Handbook ], 23 rd Edition, Vieweg, 1999, pages 445-446. In regulated two-stage supercharging, two exhaust gas turbochargers of different sizes are connected in series. The stream of exhaust gas first flows into an exhaust manifold. From there, the exhaust gas stream is expanded via a high-pressure turbine. When large volumes of exhaust are present, as at high rpm, a portion of the mass flow of the exhaust gas can be diverted around the high-pressure turbine through a bypass. The entire exhaust gas mass flow is then utilized by a low-pressure turbine downstream of the high-pressure turbine. The mass flow of aspirated fresh air is first precompressed by a low-pressure stage and then compressed further in the high-pressure stage. Ideally, the fresh air mass flow is intercooled between the low-pressure stage and the high-pressure stage. At low engine rpm, i.e., low exhaust gas mass flow rates, the bypass circumventing the high-pressure turbine remains completely closed and the entire exhaust gas mass flow is expanded via the high-pressure turbine. This produces a very rapid and high build-up of boost pressure. As the rpm increases, the expansion work is continuously shifted to the low-pressure turbine by virtue of a corresponding increase in the cross section of the bypass. Thus, regulated two-stage supercharging permits infinitely variable adjustment to engine demands on the turbine and compressor side. Due to the decreasing flow of exhaust gas through the high-pressure turbine, the compressor power of the high-pressure compressor also decreases. When large fresh air mass flows are present, the compression is done by the low-pressure compressor alone. Fresh air does flow through the high-pressure compressor, but the pressure before and after the high-pressure compressor is the same. As soon as the choke limit of the high-pressure compressor is exceeded, that is, once the stream of fresh air flowing through the high-pressure compressor exceeds the volume flow that the high-pressure compressor can handle without pressure loss, the high-pressure compressor acts as a choke and the pressure of the fresh air decreases as it flows through the high-pressure compressor. To keep the choke limit from being exceeded, when fresh air mass flow rates are high, a portion of the fresh air is diverted around the high-pressure compressor through a compressor bypass. The compressor bypass contains a valve that closes or opens the bypass. This valve is currently controlled by means of an external control unit. A sequence valve for sequential supercharging using two exhaust gas turbochargers is known from ATZ Automobiltechnische Zeitschrift 88 (1986), page 268. At low rpm, the sequence valve initially causes the fresh air to bypass one of the two compressors. The second compressor is not tied in until higher rotational speeds are reached. For this purpose, the bypass is made to accommodate a displacement body, the upstream and downstream sides of which are both subjected to a pressure force in the closed state. As long as the pressure force on the downstream side is greater than that on the upstream side, the valve is closed. As soon as the pressure on the upstream and downstream sides is equal, the valve opens. Since the entire displacement body is moved each time, a relatively large mass must be moved in order to open and close the bypass. This makes for relatively slow opening of the valve. An internal combustion engine provided with supercharging in a high-pressure turbine and a low-pressure stage that is larger than the high-pressure stage is disclosed in DE A [Published German Patent Application] 195 14 572. To obtain the most lag-free supercharging possible, the high-pressure turbine and the low-pressure turbine are initially connected in series. At about 50 to 60% of the rated rpm, the exhaust gas is diverted completely around the high-pressure turbine through a bypass. This consequently simultaneously shuts off the high-pressure compressor, which is driven by the high-pressure turbine and is connected in series to a low-pressure compressor driven by the low-pressure turbine. In this case, the high-pressure compressor is circumvented via a boost-air line that contains a check valve to prevent boost air from flowing back through the boost-air line while the high-pressure compressor is operating. However, DE A 195 14 572 gives no indication of whether the check valve is self-actuating or is controlled from the outside. Nor does the document disclose the differential pressure at which the check valve closes the boost air line. SUMMARY OF THE INVENTION In a method of effecting multistage supercharging in an internal combustion engine comprising a supercharging system, fresh air is first routed through a low-pressure compressor. At least a portion of the compressed air stream is compressed further in a high-pressure compressor. The rest of the fresh air compressed in the low-pressure compressor is routed around the high-pressure compressor through a compressor bypass. The compressor bypass is opened or closed by a self-actuating valve in dependence on the differential pressure at the high-pressure compressor, the self-actuating valve being adjusted in the compressor bypass in such a way that it opens as soon as the pressure after the high-pressure compressor is lower than the pressure before the high-pressure compressor. All the fresh air is ultimately delivered to the internal combustion engine. The fact that the self-actuating valve does not open until the pressure downstream from the high-pressure compressor is lower than the pressure upstream of the high-pressure compressor ensures that the entire air stream is routed through the high-pressure compressor as long as the latter is helping to compress the air. Only when the high-pressure compressor is no longer contributing to air compression, but on the contrary is actually acting as a choke—which occurs as soon as air is being forced through the compressor without the compressor being driven adequately—is the compressor bypass opened to the boost air. In a preferred embodiment, the self-actuating valve opens when there is a pressure difference of less than 100 mbar. One advantage of the low pressure differential at which the compressor bypass opens is that it prevents kickback or pulsation of the valve body in response to pressure fluctuations. When pressure fluctuations occur, the pressure difference in the high-pressure compressor usually does not fall below 100 mbar, and thus when there are small pressure differences of less than 100 mbar the self-actuating valve remains open even in the presence of pressure fluctuations. A further advantage of the low opening pressure is the ability to utilize both the high-pressure and the low-pressure stages in an optimum manner. This prevents unnecessary pressure losses. The self-actuating valve comprises, for example, a displacement body accommodated in a valve housing. The displacement body is divided into at least two displacement parts, of which a first displacement part, facing the upstream side, closes or opens the compressor bypass. In a further embodiment, the self-actuating valve is a flap valve with a return spring. The advantage of a self-actuating valve for opening or closing the compressor bypass is that there is no need for a valve actuator. It is also unnecessary to implement a valve control function in the control unit. In a preferred embodiment, the fresh air is cooled in a first heat exchanger downstream of the low-pressure compressor. The fresh air is preferably cooled in a second heat exchanger before entering the internal combustion engine. The low-pressure compressor used to compress the fresh air is preferably actuated by a low-pressure turbine and the high-pressure compressor by a high-pressure turbine. In this case, the low-pressure turbine and the high-pressure turbine are preferably driven by the stream of exhaust gas leaving the engine. A portion of the exhaust gas can be diverted around the high-pressure turbine through a high-pressure bypass and the low-pressure turbine through a low-pressure bypass. Valves are preferably disposed in both the high-pressure bypass and the low-pressure bypass in order to adjust the volume of exhaust gas circumventing the high-pressure and low-pressure turbines, respectively. Particularly when the low-pressure compressor and the high-pressure compressor are handling high flow rates of the kind that occur at high rotational speeds, the volume flow in the high-pressure compressor can exceed the delivery limit of the compressor. This causes the high-pressure compressor to act as a choke, and the pressure after the high-pressure compressor to be lower than the pressure before the high-pressure compressor. To keep the volume flow in the high-pressure compressor from becoming greater than the delivery capacity of the high-pressure compressor, a portion of the fresh air can be routed around the high-pressure compressor through the compressor bypass. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a method flow diagram of a two-stage supercharging system; FIG. 2 illustrates an embodiment of a self-actuating valve with a displacement body accommodated therein; and FIG. 3 shows the valve of FIG. 2 with the compressor bypass closed. Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow diagram of a two-stage supercharging system. Fresh air 1 is delivered to a low-pressure compressor 2 . In low-pressure compressor 2 , the air is compressed to a pressure above the ambient pressure. Since the air heats as it is being compressed, in the embodiment shown in FIG. 1 the low-pressure compressor is followed by a first heat exchanger 3 in which the fresh air 1 compressed by low-pressure compressor 2 is cooled. The heat exchanger 3 can also be omitted, however. The fresh air 1 compressed in low-pressure compressor 2 is delivered to a high-pressure compressor 4 . In high-pressure compressor 4 , the air compressed in low-pressure compressor 2 is compressed further. After the fresh air 1 has been compressed in high-pressure compressor 4 , the fresh air 1 is delivered to an internal combustion engine 8 . Internal combustion engine 8 can be operated on either a self-ignition or a spark-ignition principle. The fresh air 1 is preferably cooled in a second heat exchanger 7 before entering the internal combustion engine 8 . To keep the volume flow through high-pressure compressor 4 from becoming greater than the maximum possible delivery capacity, a compressor bypass 5 branches off in front of high-pressure compressor 4 . Compressor bypass 5 is closed by a self-actuating valve 6 . Self-actuating valve 6 is implemented, for example, as a check valve that opens as soon as the pressure downstream from the self-actuating valve in the direction of flow becomes lower than the pressure upstream of the self-actuating valve 6 . This phenomenon occurs when the volume flow in high-pressure compressor 4 is greater than its maximum delivery capacity. In that case, high-pressure compressor 4 acts as a choke. High-pressure compressor 4 is preferably driven via a first shaft 45 by a high-pressure turbine 9 , which is driven by an exhaust gas stream 15 emitted by the internal combustion engine 8 . At low engine speeds, that is, at low mass flows of exhaust gas, high-pressure bypass 10 remains completely closed and the entire mass flow of exhaust gas is expanded via high-pressure turbine 9 . This results in a faster and higher build-up of boost pressure. As the rotational speed of the internal combustion engine 8 increases and the mass flow of exhaust gas therefore also increases, the cross section of high-pressure bypass 10 is continuously enlarged by the opening of a first exhaust gas regulating valve 11 . Enlarging the cross section of high-pressure bypass 10 reduces the portion of the exhaust gas mass flow acting on high-pressure turbine 9 . The power transmitted from high-pressure turbine 9 to high-pressure compressor 4 can be reduced in this way. As the compressor power decreases, fresh air 1 passes through high-pressure compressor 4 without being compressed further. A pressure ratio of Π=1 becomes established, i.e., the pressure upstream of the high-pressure compressor and downstream from the high-pressure compressor is the same. As soon as the fresh air stream delivered to high-pressure compressor 4 is greater than the maximum delivery capacity of high-pressure compressor 4 , high-pressure compressor 4 acts as a choke and the pressure decreases. As soon as the pressure downstream from high-pressure compressor 4 becomes lower than the pressure upstream of high-pressure compressor 4 , self-actuating valve 6 opens compressor bypass 5 . This causes a portion of the fresh air 1 to flow through compressor bypass 5 , and the volume flow through high-pressure compressor 4 adjusts so that the pressure upstream of and downstream from high-pressure compressor 4 is the same. The opening pressure of self-actuating valve 6 is preferably set at a value Δp<100 mbar. This means that the self-actuating valve opens as soon as the pressure downstream from self-actuating valve 6 is lower than the pressure upstream of self-actuating valve 6 by the opening pressure difference. Low-pressure compressor 2 is preferably driven via a second shaft 46 by a low-pressure turbine 12 . The exhaust gas stream can be diverted around low-pressure turbine 12 through a low-pressure bypass 13 that can be opened or closed by a second exhaust gas regulating valve 14 . First exhaust gas regulating valve 11 and second exhaust gas regulating valve 14 are preferably controlled by an external control unit. FIG. 2 depicts an opened self-actuating valve. Self-actuating valve 6 comprises a valve housing 16 with a displacement body 17 accommodated therein. Displacement body 17 is divided into a first displacement part 18 and a second displacement part 19 . First displacement part 18 faces the upstream side, i.e., the side of displacement body 17 first impinged on by the flow of fresh air. The inflow direction is indicated by the arrow marked with reference numeral 20 . Formed between first displacement part 18 and second displacement part 19 is a cavity 21 in which a resilient element 22 is accommodated. Resilient element 22 is preferably a spiral spring implemented as a pressure spring. Resilient element 22 bears with one end against an inner face 23 of first displacement part 18 and with the second end against a shoulder 24 of a bushing 25 that is connected to second displacement part 19 . The flow is incident on first displacement part 18 at an upstream side 26 that is opposite inner face 23 of first displacement part 18 . The air striking this upstream side 26 exerts a pressure force on first displacement part 18 . As long as the pressure force on the upstream side 26 of first displacement part 18 is greater than the biasing force of resilient element 22 exerted on the inner face 23 of first displacement part 18 , compressor bypass 5 is open. As the pressure of the air in compressor bypass 5 decreases, so does the pressure force on the upstream side 26 of first displacement part 18 . As soon as the pressure force on upstream side 26 is lower than the biasing force of resilient element 22 , first displacement part 18 moves against the inflow direction 20 of the air and is placed, with a sealing element 27 , in a closure seat 28 (cf. FIG. 3 ). As the pressure of the air in compressor bypass 5 increases, so does the pressure force on upstream side 26 . As soon as the pressure force on upstream side 26 is greater than the biasing force of resilient element 22 , first displacement part 18 lifts out of its closure seat 28 and opens compressor bypass 5 . The fresh air then flows around displacement body 17 into a throat 29 formed between displacement body 17 and valve housing 16 . Second displacement part 19 is held in valve housing 16 by bridges 30 . Said bridges 30 have, for example, a rectangular, triangular, circular or teardrop-shaped cross section, or any other cross section known to those skilled in the art. In a preferred embodiment, the cross section of the bridges 30 is configured as teardrop-shaped, the fresh air being incident on the semicircular end of the teardrop-shaped bridge 30 . The bridge 30 is thereby configured in a particularly flow-promoting manner in the inflow direction. Fashioned in second displacement part 19 is a bore 31 in which a guide pin 32 is movably received. First displacement part 18 is fixed to guide pin 32 at the end facing upstream side 26 . The connection of guide pin 32 to first displacement part 18 can be made in a force-locking or a form-locking manner. Thus, the connection can be effected, for example, by shrinking, as a press fit, as a screw connection, as a glued joint or as a welded joint. Guide pin 32 is preferably connected to first displacement part 18 by shrinking. The length of guide pin 32 is so calculated that when compressor bypass 5 is closed, a large enough segment of guide pin 32 remains accommodated in bore 31 so that it cannot tilt or drop out of bore 31 . In order for first displacement part 18 to be moved in inflow direction 20 or against inflow direction 20 , bore 31 is preferably oriented parallel to inflow direction 20 . A bushing 33 in which guide pin 32 is guided is preferably accommodated in bore 31 . Bushing 33 is preferably made of a static-friction-reducing material, for example PTFE, to improve the sliding properties of guide pin 32 . In the embodiment shown here, a chuck 34 that projects into cavity 21 is formed on second displacement part 19 . Said chuck 34 prolongs the bore 31 that receives guide pin 32 . The prolonged bore 31 increases the guide length of guide pin 32 in bore 31 , thereby ensuring that guide pin 32 will not tilt in bore 31 . As on second displacement part 19 , a chuck 35 that projects into cavity 21 is also formed on first displacement part 18 . Fashioned in chuck 35 is a bore 36 that receives guide pin 32 . In bore 36 , guide pin 32 is connected to first displacement part 18 in a force-locking or form-locking manner. Bushing 25 embraces chuck 34 on second displacement part 19 . Bushing 25 is preferably fastened force-lockingly to chuck 34 of second displacement part 19 , for example by means of a screw connection. The biasing force of resilient element 22 can be adjusted by means of the position of shoulder 24 , which, for example, can be moved toward or away from first displacement part 18 by a screwing movement of screwed-on bushing 25 . As the distance between shoulder 24 and the inner face 23 of first displacement part 18 decreases, the biasing force in resilient element 22 increases. As the biasing force of resilient element 22 increases, greater force and thus a higher pressure in compressor bypass 5 on the upstream side 26 of first displacement part 18 are needed to open compressor bypass 5 . For installation purposes, valve housing 16 is preferably divided into a first housing part 37 and a second housing part 38 . Valve housing 16 is preferably divided at the position of accommodation of a retaining ring 39 to which the bridges 30 of second displacement part 19 are connected. Retaining ring 39 is received by a groove 40 in valve housing 16 . To permit assembly, one portion of groove 40 is formed in first housing part 37 and the other in second housing part 38 . Fitting the housing parts 37 , 38 together causes the cross section of groove 40 to assume the same shape as the cross section of retaining ring 39 . After the assembly of housing parts 37 , 28 [sic] and second displacement part 19 with retaining ring 39 mounted thereon via bridges 30 , the valve housing 16 is embraced by a band clamp 41 , for example a V-band clamp or any other band clamp known to those skilled in the art. A groove 42 is formed in band clamp 41 and a collar 43 is formed on valve housing 16 . The cross section of collar 43 and the cross section of groove 42 are the same. So that housing parts 37 , 38 can be joined to each other by means of band clamp 42 , the collar 43 is formed half in first housing part 37 and half in second housing part 38 . Thus, fitting the housing parts 37 , 38 together produces collar 43 , whose cross section matches that of groove 43 in band clamp 41 . A durable connection of first housing part 37 to second housing part 38 is achieved by force- or form-locking connection with band clamp 41 . FIG. 3 shows a closed self-actuating valve according to FIG. 2 . As long as the pressure of the fresh air in the compressor bypass 5 is so low that the pressure force acting on upstream side 26 is lower than the biasing force of resilient element 22 , first displacement part 18 is positioned with sealing element 27 in closure seat 28 . As soon as the pressure of the fresh air in compressor bypass 5 is so great that the pressure force on upstream side 26 becomes greater than the biasing force of resilient element 22 , first displacement part 18 lifts out of closure seat 28 and thereby opens compressor bypass 5 . To keep resilient element 22 from bending while being compressed during the movement of first displacement part 18 toward second displacement part 19 , bushing 25 embraces resilient element 22 . An enlarged bearing surface of resilient element 22 on bushing 25 is obtained by the fact that bushing 25 protrudes beyond chuck 34 . Chuck 35 on first displacement part 18 is shaped so that it is received by bushing 25 and embraced by bushing 25 when compressor bypass 5 is open. When chuck 25 [sic] is inserted into bushing 25 , a cushion of air that damps the movement of first displacement part 18 forms inside bushing 25 between chuck 34 on second displacement part 19 and chuck 35 on first displacement part 18 . This prevents first displacement part 18 from striking sharply against second displacement part 19 , and thus any potential rebounding. While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

A method of effecting multi-stage supercharging in internal combustion machines comprising a supercharging system, wherein fresh air is first routed through a low-pressure compressor. At least a portion of the compressed air stream is compressed further in a high-pressure compressor, and the rest of the fresh air compressed in the low-pressure compressor is routed around the high-pressure compressor via a compressor bypass. All the fresh air is ultimately delivered to the internal combustion engine. The compressor bypass is opened or closed by a self-actuating valve in dependence on the differential pressure, the compressor bypass opening as soon as the pressure downstream from the high-pressure compressor is lower than the pressure upstream of the high-pressure compressor.

CROSS REFERENCE The present disclosure claims priority from U.S. Provisional Patent Application Ser. No. 60/447,391, filed on Feb. 14, 2003, which is hereby incorporated by reference. BACKGROUND The present disclosure relates generally to wireless communication networks and, more specifically, to a method and system whereby a wireless mobile device may report the status of a non-emergency-services position-determination (NESPD) capability, wherein the NESPD capability is user-selectable. Location based services (LBSs) are increasingly important across wireless networks. Generally, there are two classes of LBSs: emergency services (ES), and value-added services (VASs). Emergency services may be used, for example, to locate a mobile phone user who places a call for emergency services. VASs may be commercial services such as navigational services, store location services, or locate-me services. Through known location services (LCS) techniques, it is possible for a wireless network and wireless mobile device to provide a location (e.g. latitude and longitude) and location-related information to an LBS provider. In some instances, the wireless mobile device may be configured to disregard LCS requests for all but ES. The wireless mobile device may be configured not to respond to VAS-related requests, or to respond, but without the requested location data, and possibly with a general-purpose reject reason. This may result in the network repeatedly sending LCS requests for VASs to the wireless mobile device since the network and/or VAS provider have no way to know exactly why the wireless mobile device is not responding to a request. The wireless mobile device has no way to unambiguously inform the network that it will only respond with LCS data to ES-related LCS requests. Accordingly, what is needed is system and method of use thereof that addresses the issues discussed above. SUMMARY The present disclosure introduces a computer data signal including a plurality of wireless mobile device native capability data (NCD) and a status indicator of a non-emergency-services position-determination (NESPD) capability. The NESPD capability is user-selectable. The NCD may include one or more of a GPS acquisition capability indicator, a position calculation capability indicator, a wireless mobile device location standard revision number indicator, a wireless mobile device digital mode indicator, and a wireless mobile device pilot phase capability indicator. A wireless communication system is also provided in the present disclosure. In one embodiment, the system includes first and second stations having first and second communication software, respectively. The first communication software may be configured to generate and transmit a capability request. The second communication software may be configured to receive the capability request and to generate and transmit a capability request response that includes a status indicator of a non-emergency-services position-determination (NESPD) capability, wherein the NESPD capability is user-selectable. The present disclosure also introduces a method of communicating between telecommunications network stations. In one embodiment, the method includes generating a capability request at a first station and transmitting the capability request to a second station, which receives the capability request. The capability request may comprise or be contained in a position determination data message (PDDM). A capability request reply, which may also comprise or be contained in a PDDM, is generated in response to the capability request at the second station, wherein the capability request reply includes a status indicator of a non-emergency-services position-determination (NESPD) capability of the second station, the NESPD capability being user-selectable. The capability request reply may also be transmitted before, or without, the capability request. The capability request reply is transmitted to and received at the first station. The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the detailed description that follows. Additional features will be described below that further form the subject of the claims herein. Those skilled in the art should appreciate that they can readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. FIG. 1 illustrates a block diagram of one embodiment of a capability request response according to aspects of the present disclosure. FIG. 2 illustrates a block diagram of one embodiment of a telecommunications network according to aspects of the present disclosure FIG. 3 illustrates a message sequence chart of one embodiment of a method of reporting the status of an emergency services position-determination capability according to aspects of the present disclosure DETAILED DESCRIPTION It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. The present disclosure is related to and hereby incorporates in its entirety, Position Determination Service Standard for Dual Mode Spread Spectrum Systems, Addendum 1, TIA/EIA IS-801-1, Telecommunications Industry Association (March, 2001). As described above, situations exist in which it is necessary or desired to determine the physical location of a wireless mobile device, such as a mobile phone, a wireless-enabled PDA, etc. For example, if a mobile phone user places a call to a police department, it may be necessary for the police department to locate the mobile device user without requiring the user to provide spoken directions. Non-emergency services may also make use of the capability to determine the position of wireless mobile devices. For example, a mobile phone user may wish to wirelessly receive directions to the nearest ATM, movie theater, restaurant, etc., without keying in the user's current location. Thus, a wireless network may be enabled to send requests to a wireless mobile device within the network (or other networks) to provide information detailing the physical location of the mobile device (e.g., latitude/longitude coordinates, etc.). However, a wireless mobile device user may also enable or disable their mobile device from automatically responding to such external requests for location information. For example, a user may disable their wireless device from transmitting location information to all requesters except emergency services providers (e.g., police and fire departments). When a mobile device has been disabled from providing location information to a non-emergency service provider, requests for location information from non-emergency service providers may nevertheless be sent to the mobile device. However, the non-emergency service provider requesting the location information will not receive the requested location information from the mobile device. Of course, the non-emergency service provider may continue to receive other messages from the mobile device not pertaining to the specific location of the mobile device. Thus, the non-emergency service provider may continue to request location information, possibly assuming that previous request for location information were corrupted, blocked, or otherwise errant. The present disclosure, however, provides for informing the non-emergency services provider that non-emergency position-determining capabilities of the mobile device have been disabled. Thus, the non-emergency service providers may cease the repeated requests for location information from the mobile device. Consequently, the non-emergency service providers may be able to limit over-the-air data traffic in cases where a mobile device has position-determining capabilities but the mobile device user has chosen to disable position-determining capabilities for location information requests from non-emergency service providers. Referring to FIG. 1 , illustrated is a block diagram (or bit map) of one embodiment of a capability request response 100 according to aspects of the present disclosure. The response 100 may be a message generated and/or transmitted by a wireless mobile device or other telecommunications network element, possibly in response to a capability request message received from another telecommunications network element, such as one including a position determining entity (PDE). The response 100 may be part of a position determination data message (PDDM), as in IS-801-1. The response 100 may include a plurality of wireless mobile device native capability data (NCD 110 a - e , collectively) and a status indicator 120 of a non-emergency-services position-determination (NESPD) capability. Each of the NCD 110 a - e may have values that are predetermined. The NCD 110 a - e may be set by the OEM, they may be hardware-specific, and/or they may depend upon the network or signal strength where the wireless mobile device is located. The NCD 110 a - e may be stored within a nonvolatile memory of a wireless mobile device. The NCD 110 a - e are not user selectable. The status indicator 120 indicates a user-selectable preference for providing position information for ES but not for VASs. The status indicator 120 may be modified by a user's interaction with the machine-human interface of a wireless mobile device as will be explained below. In the illustrated embodiment, the response 100 includes a wireless mobile device location standard revision indicator (MS_LS_REV) 110 a , a wireless mobile device digital mode indicator (MS_MODE) 110 b , and a wireless mobile device pilot phase capability indicator (PILOT_PH_CAP) 110 c . Other examples of NCD in the illustrated embodiment include a GPS acquisition capability indicator (GPS_ACQ_CAP) 110 d and a position calculation capability indicator (LOC_CALC_CAP) 110 e. The MS_LS_REV 110 a may indicate the wireless mobile device location standard revision being used by the wireless mobile device. For example, IS-801-1 may be used by the wireless mobile device, which may correspond to a value in the MS_LS_REV 110 a of ‘000001’. In such case, the MS_LS_REV 110 a field may be set to ‘00001’ and may not be changeable by a wireless mobile device user. In the illustrated embodiment, the MS_LS_REV 110 a has a length of 6 bits, although other lengths are within the scope of the present disclosure. The MS_MODE 110 b may indicate the digital mode of the wireless mobile device. If, for example, the wireless mobile device operates under the IS-801-1 protocol, this field may have the value of ‘0000’. MS_MODE 110 b is based on the wireless mobile device and is not changeable by the user. In the illustrated embodiment, the MS_MODE 110 b has a length of 4 bits, although other lengths are within the scope of the present disclosure. The PILOT_PH_CAP 110 c may be used to store the pilot phase capability of the wireless mobile device. Specified values for the PILOT_PH_CAP 110 c field may be based upon the capability of the wireless mobile device. For example, in the IS-801-1 standard, the values ‘000000’, ‘000001’, ‘000010’, ‘000011’, and ‘000100’ correspond to full chip measurement capability, half chip measurement capability, quarter chip measurement capability, eighth chip measurement capability, and one sixteenth chip measurement capability, respectively. The remaining possible values of PILOT_PH_CAP 110 c may be reserved for future use. The value taken by PILOT_PH_CAP 110 c may be hardware dependent and hence not selectable or changeable by the wireless mobile device user. In the illustrated embodiment, the PILOT_PH_CAP 110 c has a length of 6 bits, although other lengths are within the scope of the present disclosure. The GPS_ACQ_CAP 110 d may correspond to the Global Positioning System (GPS) acquisition capability of the wireless mobile device. Each bit in the GPS_ACQ_CAP 110 d field may represent one of several GPS acquisition capabilities. For example, if, as in the IS-801-1 standard, the GPS_ACQ_CAP 110 d field has a total of 12 bits, bits 1 - 7 may correspond to GPS acquisition assistance, GPS sensitivity assistance, GPS almanac, GPS ephemeris, GPS navigation message bits, GPS almanac correction, and GPS autonomous acquisition capable, respectively. Bits 8 - 12 may be reserved. The GPS_ACQ_CAP 110 d field may correspond to the hardware capabilities of the wireless mobile device such that they are not user selectable or changeable. In the illustrated embodiment, GPS_ACQ_CAP 110 d has a length of 12 bits, although other lengths are within the scope of the present disclosure. The LOC_CALC_CAP 110 e field may be set to indicate the position calculation capability of a wireless mobile device. Each bit in the LOC_CALC_CAP 110 e field may correspond to one of several position calculation capabilities. For example if, as in IS-801-1, the LOC_CALC_CAP 110 e field has a total of 12 bits, bits 1 and 2 may correspond to a wireless mobile device being location calculation capable using spherical location assistance and Cartesian location assistance, respectively. Bit 3 may correspond to advanced forward link trilateration (AFLT) location calculation capability. Bits 4 - 6 may correspond to location calculation capable using GPS almanac assistance, GPS ephemeris assistance, and GPS almanac correction, respectively. Bit 7 may correspond to the wireless mobile device being autonomous location calculation capable, while bit 8 may indicate hybrid GPS and AFLT location calculation capability. Bits 9 - 11 may be reserved and bit 12 may be used to indicate a pre-programmed location capability. In the illustrated embodiment, the LOC_CALC_CAP 110 e has a length of 12 bits, although other lengths are within the scope of the present disclosure. The EMERGENCY_ONLY status indicator 120 indicates the status of the NESPD capability of the wireless mobile device or other applicable telecommunications network element. The EMERGENCY_ONLY status indicator 120 indicates a user-preference to refrain from providing position information for VASs although capability for providing position information for EMERGENCY services may remain active. The wireless mobile device may support various LCS capabilities, as described above, and may relay such capabilities to another station in the network, such as a BTS or a PDE, by transmitting the NCD 110 a - e . The user may disable the LCS capabilities of the wireless mobile device for all but EMERGENCY SERVICES LBSs. If so, the user may also wish to inform a PDE that the LCS capabilities of the wireless mobile device have been disabled for all but EMERGENCY SERVICES LBSs. The user of the wireless mobile device may do so by setting the EMERGENCY_ONLY 120 status indicator to true. When following the IS-801-1 standard conventions, true corresponds to a value of ‘1’ while false corresponds to a value of ‘0’. In this embodiment, the EMERGENCY_ONLY 120 status indicator comprises a single bit. However, in some embodiments more bits may be used. For example, one or more of the reserved bits 130 could be used for the EMERGENCY_ONLY 120 status indicator. The user may set the EMERGENCY_ONLY 120 indicator to true manually, or it may be automatically set to true by the wireless mobile device when VAS LBSs are disabled. The user may select the value of EMERGENCY_ONLY 120 when the wireless mobile device is in use, when the wireless mobile device is idle, or at startup. A default value may be set by the user, to which the stored EMERGENCY_ONLY 120 bit always resets during power up, or power down. The user may also be able to associate a stored EMERGENCY_ONLY 120 value with a profile for the wireless mobile device. For example, EMERGENCY_ONLY indicator may be set to a particular stored value when the wireless mobile device leaves a certain area, or during certain hours. As another example, the mobile user may wish to allow VAS LBSs only when in a home city and during business hours. Other user defined events corresponding to a change in the value of the stored EMERGENCY_ONLY 120 status indicator are also possible. FIG. 2 illustrates a block diagram of one embodiment of a wireless telecommunications network 200 according to aspects of the present disclosure. The telecommunications network 200 is one environment in which the response 100 shown in FIG. 1 may be employed. The telecommunications network 200 includes a wireless mobile device 210 that may be in communication with a base transceiver station or system (hereafter collectively referred to as “BTS”) 220 . The BTS 220 may be part of a base station (BS), which may comprise other BTSs (not shown) and a base station controller (BSC) 230 . The BTS 220 may be controlled by the BSC 230 , which may in turn be controlled by a mobile switching center (MSC) 240 . The MSC 240 may receive calls from, or route calls to, a public switched telephone network (PSTN) 250 . An emergency services network 260 may interact with the PSTN 250 and also connect to a public safety answering point (PSAP 270 ) and a mobile positioning center (MPC) 275 . The MPC 275 may communicate with MSC 240 , and may operate to locate wireless mobile device 210 through position determining entity (PDE) 280 . VAS provider 285 may also locate wireless mobile device 210 through the MPC 275 and PDE 280 . The wireless mobile device 210 may comprise a cellular telephone, a PDA, a pager, a personal computer with a wireless modem, an onboard vehicle computer, or another device for which location data may be desired. Here, only a single wireless mobile device 210 is shown although there may be many more in the same telecommunications network 200 . The wireless mobile device may be in communication with the BTS 220 . Here again, only a single BTS 220 is shown but the telecommunications network 200 may include many. In another embodiment, the wireless mobile device 210 may be in communication with multiple BTSs and possibly other wireless mobile devices. The wireless mobile device 210 may communicate with the BTS 220 using various wireless protocols. For example, the protocol be may related to, but is not limited to, CDMA, 1xRTT, TDMA, analog (e.g., AMPS), FDMA, GSM, UMTS, Bluetooth, or Wi-Fi. The BTS 220 may be operated or controlled by BSC 230 . The BSC 230 may control multiple BTSs and may control how wireless mobile devices are allocated to the multiple BTSs and how the wireless mobile devices are handed-off between the BTSs. There may be multiple BSCs within the network 200 although only one is shown here. The BSC 230 , and possibly others, may be in communication with the MSC 240 . The MSC 240 may be a single element, or a network of elements, that routes calls and information to and from the BSC 230 , or to other network elements. There may also be multiple MSCs within a network. The MSC 240 may connect the wireless portion of the telecommunications network 200 to the PSTN 250 . The PSTN 250 may be an ordinary public switched telephone network. The PSTN 260 may be connected to an emergency services network 260 , such as that used to report fires or call the police. The emergency services network may connected to or integrated with a Public safety answering point (PSAP) 270 . Emergency calls made by wireless mobile devices may be routed to or received by the PSAP 270 . An operator on the PSAP may be able to obtain location information about the mobile wireless device 210 via the MPC 275 and the PDE 280 . As previously described, a VAS provider 285 may provide LBSs to the wireless mobile device 210 . The VAS provider may also obtain location information from the PDE 280 via the MPC 275 . To illustrate one embodiment of the present disclosure in operation, wireless mobile device 210 may register with the network 200 , or originate a call, and advise the network 200 of its general latent LCS capabilities, possibly in associated IS-2000 signaling messages (IS-2000 referring to TIA/EIA/IS-2000.5.A-1, Upper Layer (Layer 3) Signaling Standard for cdma2000 Spread Spectrum Systems, Addendum 1, November, 2000). If wireless mobile device 210 indicates support for the IS-801-1 protocol, the PDE 280 may establish a session with the wireless mobile device 210 for the exchange of application layer protocols. The protocol messages may be exchanged between the wireless mobile device 210 and the PDE 280 in the form of position data determination messages (PDDMs). It is understood, however, that PDDMs may pass between other network elements such as the MSC 240 and BSC 230 in route between the PDE 280 and wireless mobile device 210 . The PDDMs may each contain one or more request and/or response elements. The PDE 280 may send a PDDM containing an information or capability request element to the wireless mobile device 210 to determine its LCS capabilities. The wireless mobile device 210 may respond with a PDDM containing LCS capability information such as that described with respect to FIG. 1 . In some instances the wireless mobile device 210 may send a PDDM with LCS capability information without first receiving a PDDM with a capability request. To further illustrate, as previously described, the wireless mobile device 210 may have LCS capabilities that are native features of the device indicated by NCD 110 a - e (of FIG. 1 ) in addition to an NESPD indicator 120 . The user of the wireless mobile device 210 may have no current interest in any VAS LBSs. For example, the user may be traveling and have no interest in having the location of the wireless mobile device 210 tracked for the use of local advertisers. The user of the wireless mobile device 210 may set the EMERGENCY_ONLY indicator 120 to true to indicate that the NESPD capabilities of the wireless mobile device have been disabled by the user. This may be accomplished, for example, by selecting a profile (e.g. a traveling profile) on the mobile device 210 , or by setting the EMERGENCY_ONLY 120 indicator to true through a manual interface on the wireless mobile device 210 . There may be a VAS provider 285 that wishes to advertise to all wireless mobile devices within a given radius of a specific advertiser. The PDE 280 may send a PDDM with an LCS request to the wireless mobile device 210 . The request may be passed through the mobile switching center 240 , to the base station controller 230 , to the BTS 220 , and wirelessly to the wireless mobile device 210 . The wireless mobile device 210 may be capable of responding with location data based on its native capabilities. However, the EMERGENCY_ONLY 120 indicator, having been set to true to indicate NESPD capability disablement by the wireless mobile device 210 user, will be sent back through the network, possibly with the NCD 110 a - e , and possibly with an indication that an LCS request other than a capability request has been rejected, to the PDE 280 . The PDE 280 will receive the message containing the EMERGENCY_ONLY 120 indicator with a value of true and may indicate to the VAS provider 285 that the wireless mobile device 210 will not respond with location information unless the LCS request is for an ES. In some cases, without first receiving a PDDM containing a request for LCS data, the wireless mobile device 210 may send a PDDM to the PDE 280 indicating that only ES-related LCS will be provided with location-related data. FIG. 3 illustrates a message sequence chart of one embodiment of a method 300 of reporting the status of a non-emergency-services position-determination (NESPD) capability according to aspects of the present disclosure. A positioning determining entity (PDE) 280 may pass a PDDM comprising a capability request corresponding to a VAS to the wireless mobile device 210 at step 310 . An NESPD capability request or other LCS request may be passed in the same PDDM. The PDDM 310 may be passed through other network elements (not shown), such as an MSC, a BSC, or a BTS, before reaching the wireless mobile device 210 . If the wireless mobile device 210 is configured to respond with LCS data only for ES LBSs, the user may have already set the EMERGENCY_ONLY ( 120 of FIG. 1 ) indicator to true. As described with reference to FIG. 1 , the EMERGENCY_ONLY value may be sent back to the PDE 280 along with NCD 110 a - e ( FIG. 1 ). A PDDM 320 containing the EMERGENCY_ONLY value of ‘1’, and possibly NCD 110 a - e , may be sent to the wireless mobile device. The PDDM 320 may also pass through a other network elements (not shown), such as an MSC, a BSC, or a BTS, before reaching the PDE 280 . Upon receiving the PDDM 320 with EMERGENCY_ONLY set to ‘1’, the PDE 280 has thereby been informed that the wireless mobile device 210 will respond to LCS data requests only for ES LBSs. PDDMs requesting LCS data for non ES LBS providers may then be stopped at step 330 . As described previously, the wireless mobile device 210 may also send the PDDM (reply with EMERGENCY_ONLY=1) 320 without first receiving the PDDM (capability request) 310 from the PDE 280 . Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

A wireless communication system including a station having communication software for: (1) receiving a capability request from each of a plurality of non-emergency-service-providers, and (2) generating and transmitting a capability request response that includes a status indicator of a non-emergency-services position-determination (NESPD) capability of the station, wherein the NESPD capability of the station is user-selectable to enable or disable all NESPD irrespective of which of the plurality of non-emergency-service-providers is associated with the capability request. Additionally, a method of operating an element of a wireless communication network, comprising: (1) exchanging NESPD messages with a mobile station; (2) receiving a status indicator from the mobile station, at least indirectly, the status indicator indicating that the mobile station is configured to refrain from providing position information for non-emergency-services; and (3) preventing a plurality of NESPD messages from being transmitted to the mobile station in response to receiving the status indicator.

RELATED APPLICATIONS The present application claims priority to and is a national phase entry under 35 U.S.C. §371 of co-pending International Application No. PCT/US2010/029002, entitled “Managing Backup Sets Based on User Feedback,” filed Mar. 29, 2010 and designating the United States, the entirety of which is hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates generally to computer-based methods and apparatuses, including computer program products, for managing backup sets based on user feedback. BACKGROUND Computer systems are ubiquitous in today's work and home environments. The data stored on these computer systems, however, is vulnerable to theft, lire, flood, and other natural disasters. A user may only realize that data of interest to the user was not backed up after the data is lost (e.g., due to disk failure). Thus, a need exists for a system that allows users to easily manage data backup. Also, a need exists for a system that analyzes modifications made by users to their backup selections to update backup set selections of other users as well as default backup selections. SUMMARY One approach to managing backup sets based on user feedback is a method. The method includes receiving an update to a backup set from a first client device. The method further includes analyzing the update made to the backup set. The method further includes updating a default backup set stored in a storage device based on the update to the backup set. Another approach to managing backup sets based on user feedback is a method. The method includes modifying a backup set. The method further includes transmitting the modified backup set to a backup set management server. The method further includes receiving, from the backup set management server, a recommended modification to a second backup set, the modification to the second backup set associated with modifications made by one or more users to backup sets associated with the one or more users. The method further includes modifying the second backup set based on the recommended modification received from the server. Another approach to managing backup sets based on user feedback is a system. The system includes a communication module configured to receive one or more modifications to one or more backup sets from one or more users. The system further includes a backup set management module. The backup set management module is configured to analyze the received one or more modifications for the one or more backup sets, and aggregate the received one or more modifications into one or more backup set updates. The system further includes a user preference module. The user preference module is configured to modify a first plurality of backup sets stored in a database based on the one or more backup sets updates. Another approach to managing backup sets based on user feedback is a system. The system includes a client backup set management module. The client backup set management module is configured to modify at least one backup set in a first plurality of backup sets. The system further includes a communication module. The communication module is configured to send the modified first plurality of backup sets to a server, and receive, from the server, one or more modifications to the first plurality of backup sets based on changes made by one or more users to a second plurality of backup sets. The client backup set management module is further configured to modify the first plurality of backup sets based on the modifications received from the server. Another approach to managing backup sets based on user feedback is a system. The system includes a means for receiving an update to a backup set from a first client device. The system further includes a means for analyzing the update made to the backup set. The system further includes a means for updating a default backup set stored in a storage device based on the update to the backup set. Another approach to managing backup sets based on user feedback is a system. The system includes a means for modifying a backup set. The system further includes a means for transmitting the modified backup set to a backup set management server. The system further includes a means for receiving, from the backup set management server, a recommended modification to a second backup set, the modification to the second backup set associated with modifications made by one or more users to backup sets associated with the one or more users. The system further includes a means for modifying the second backup set based on the recommended modification received from the server. Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating the principles of the invention by way of example only. BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments taught herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which: FIG. 1 is a block diagram illustrating an exemplary system, according to one exemplary embodiment; FIG. 2 is a block diagram illustrating an exemplary data center, according to one exemplary embodiment; FIG. 3 is block diagram illustrating an exemplary logical data site, according to one exemplary embodiment; FIG. 4 is a block diagram illustrating an exemplary data center storing user data backup from client devices, according to one exemplary embodiment; FIG. 5 illustrates exemplary user data and user data backup, according to one exemplary embodiment; FIG. 6 is a block diagram illustrating an exemplary logical data site management server, according to one exemplary embodiment; FIG. 7 is a block diagram illustrating an exemplary storage server, according to one exemplary embodiment; FIG. 8 is a block diagram illustrating an exemplary client device, according to one exemplary embodiment; FIG. 9 is a relational diagram illustrating relationship between a user and backup sets; FIG. 10A is a block diagram illustrating an exemplary management server; FIG. 10B is a block diagram illustrating an exemplary client device; FIG. 11 illustrates an exemplary backup policy; FIG. 12 illustrates another exemplary backup policy; FIGS. 13, 14, and 15 illustrate exemplary interfaces displaying backup sets; FIG. 16 illustrates an exemplary interface for creating a new backup set or for updating an existing backup set; FIG. 17 illustrates an exemplary interface for displaying storage usage information; FIG. 18 illustrates a flow chart of the exemplary flow of data between a client device and a management server; FIG. 19 illustrates a flow chart of the exemplary flow of data between a new client device and a management server; and FIG. 20 illustrates a flow chart showing processing of backup sets, according to an exemplary embodiment. It will be recognized that some or all of the figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The figures are provided for the purpose of illustrating one or more embodiments of the invention with the explicit understanding that they will not be used to limit the scope or the meaning of the claims. DETAILED DESCRIPTION Before turning to the figures which illustrate the exemplary embodiments in detail, it should be understood that the disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. FIG. 1 illustrates an exemplary system 100 for backup and restoration of user data (e.g., one or more document files, one or more audio files, etc.) between client devices A 140 a , B 140 b , C 140 c through Z 140 z (e.g., personal computer, server computing system, personal digital assistant, phone, music player, etc.) and data centers A 110 a , B 110 b through Z 110 z (e.g., server systems with a plurality of data storage devices, server systems connected to a plurality of network data storage devices, etc.). The system 100 includes a communication network 130 (e.g., internet protocol (IP) network, a local area network (LAN), internet, etc.) and a backup system management server 120 . Each data center A 110 a , B 110 b through Z 110 z includes a plurality of logical data sites 1 , 2 through 9 , 112 a , 112 b through 112 z , 114 a , 114 b through 114 z , and 116 a , 116 b , through 116 z , respectively. Each client device A 140 a , B 140 b , C 140 c through Z 140 z includes a client backup module 142 a , 142 b , 142 c , through 142 z , respectively. The data centers 110 a - 110 z , the client devices 140 a - 140 z , and/or the backup system management server 120 communicate via the communication network 130 . The backup system management server 120 can manage the backup of user data from the client devices 140 a - 140 z to one or more of the logical data sites at one or more of the data centers 110 a - 110 z . The backup system management server 120 can manage the restoration of user data from one or more of the logical data sites at one or more of the data centers 110 a - 110 z to the client devices 140 a - 140 z . The backup system management server 120 can communicate with the client backup module 142 a - 142 z on each client device 140 a - 140 z to manage the backup and/or restoration of the user data (e.g., pause backup, start backup, select backup set, start restoration, schedule backup, communicate a backup policy, update a backup set, etc.). In some examples, the restoration of the user data is to the originating client device (e.g., the client device from which the user data originated from, the client device connected to the computing device which the user data originated from, etc.). In other examples, the restoration of the user data is to another client device that is not the originating client device (e.g., new user computer, etc.). In other examples, each data center 110 a - 110 z includes a data center management server (not shown) for managing the backup and/or the restoration of the user data. In some examples, each logical site includes a site management server for managing the backup and/or the restoration of the user data. In other examples, the backup system management server 120 manages the backup and/or the restoration of the user data by managing one or more of the data center management servers and/or one or more of the site management servers. Although FIG. 1 illustrates a single communication network 130 , the system can include a plurality of communication networks and/or the plurality of communication networks can be configured in a plurality of ways (e.g., a plurality of interconnected local area networks (LAN), a plurality of interconnected wide area network (WAN), a plurality of interconnected LANs and/or WANs, etc.). Although FIG. 1 illustrates the data centers A 110 a , B 110 b through Z 110 z , the logical data sites 1 , 2 through 9 (e.g. 112 a - 112 z ), and the client device A 140 a , B 140 b , C 140 c through Z 140 z , the system 100 can include any number of data centers, logical data sites, and/or client devices. In some examples, data centers A, 13 , and C include ten logical data sites and data centers D, E, F, and G include twenty logical data sites. In other examples, ten thousand client devices are associated with each logical data site. In this example, data center G is associated with two hundred thousand client devices since data center G includes twenty logical data sites and each logical data site is associated with ten thousand client devices. FIG. 2 illustrates an exemplary data center 210 . The data center 210 includes a data center management server 212 , logical data sites A 214 a , B 214 b through Z 214 z , and a communication network 218 . Each logical data site A 214 a , B 214 b through Z 214 z includes a site management server A 215 a , B 215 b through Z 215 z and one or more storage volumes 216 a , 216 b through 216 z (e.g., logical storage volumes, storage devices, distributed storage devices, etc.). The data center management server 212 and/or the site manager servers 215 a , 215 b through 215 z can manage the plurality of logical data sites 214 a - 214 z. Each logical data site A 214 a , B 214 b through Z 214 z can store and/or retrieve the backup of user data associated with a plurality of users (e.g., subscribers to a backup subscription service, users in a corporate network, etc.). The storage volumes 216 a - 216 z at each logical site 214 a - 214 z can store and/or retrieve the backup of the user data. In some examples, the backup of the user data is stored on a single storage volume (e.g., single storage device, single logical storage volume, redundant array of inexpensive disks (RAID) storage device, etc.). In other examples, the backup of the user data is stored on one or more storage volumes (e.g., distributed backup among a plurality of storage devices, redundant backup among a plurality of logical storage volumes, redundant backup among a plurality of RAID storage devices, etc.). In some examples, the data center management server 212 manages the backup and/or the restoration for the data center 210 and the site manager server manages the storage and/or retrieval at the respective logical data site. Although FIG. 2 illustrates a data center 210 with the logical data sites A 214 a , B 214 b through Z 214 z , the data center 210 can include a single logical data site or any number of logical data sites (e.g., twenty, forty, one hundred, etc.). Although FIG. 2 illustrates the data center management server 212 and/or the site management server, the storage and/or retrieval of the backups of user data can be managed individually by either the data center management server 212 or the site management server at each respective logical site. FIG. 3A illustrates a logical data site 304 . The logical data site 304 includes a site management server 305 and storage server A 310 a , B 314 b through Z 320 z . The storage server A 310 a includes a storage volume A 312 a . The storage server B 314 b includes a storage volume B 1 316 b and a storage volume B 2 318 b . The storage server Z 320 z includes storage volumes Z 1 322 z through Z 3 328 z . Any number of storage volumes can be grouped within a storage server. Each storage volume includes a plurality of user data backup (not shown). The site management server 305 can communicate with the storage servers A 310 a , B 314 b through Z 320 z to backup and/or restore the backup of the user data. Although FIG. 3A illustrates storage servers A 310 a , B 314 b through Z 320 z and storage volumes 312 a , 316 b , 318 b , 322 z through 328 z , the logical data site 304 can include any number of storage servers and/or storage volumes. For example, the logical data site 304 can include four storage servers and each storage server includes forty storage volumes. In some embodiments, the site management server 305 can include a database server and a server managing storage bandwidth resources for the logical data site 304 . In these embodiments, the site management server 305 can control one or more communications servers that act as intermediary between client communication module 805 and the storage servers A 310 a , B 314 b through Z 320 z. FIG. 3B illustrates logical data site 334 . The logical data site 334 includes a site management server 335 and a storage server 320 . The storage server 320 includes storage volumes A 330 a , B 330 b through Z 330 z . Each storage volume A 330 a , B 330 b through Z 330 z includes plurality of user data 1 , 2 through 9 (e.g., the user data is the backup of the user data stored on a client device associated with the user). The site management server 335 can communicate with the storage server 320 and/or the storage volumes A 330 a , B 330 b through Z 330 z to backup and/or restore the backup of the user data. In some examples, the site management server 335 can communicate with the storage volumes to transfer user data between the storage volumes. In some examples, the site management server 335 can communicate with one or more site management servers (not shown) at one or more other logical data sites (not shown to transfer user data between the logical data sites. Although FIG. 3B illustrates storage volumes A 330 a , B 330 b through Z 330 z and user data 1 , 2 through 9 , the logical data site 334 can include any number of storage volumes and/or user data. For example, the logical data site 334 can include twenty storage volumes and each storage volume includes user data associated with one thousand users. FIG. 4 illustrates an exemplary data center 410 for the backup of user data from one or more client devices 440 a , 440 b , and 440 c . The data center 410 includes a logical data site 412 . The logical data site 412 includes a storage volume 414 . The storage volume 434 includes user data backups A 432 a , B 432 b , and C 432 c . The user data backups A 422 a , B 422 b , and C 422 c correspond to user data A 432 a , B 432 b , and C 432 c , respectively. The user data A 432 a , B 432 b , and C 432 c are stored on the client devices, computer A 440 a , personal digital assistant 440 b , and computer B 440 c , respectively. As illustrated in FIG. 4 , the user data A 432 a , B 432 b , and C 432 c stored on the client devices is backed up to the storage volume 414 on the logical data site 412 in the data center 410 . FIG. 5 illustrates exemplary user data 510 and user data backup 520 . The user data 510 includes a plurality of files, image files 511 , document files 512 , video files 513 , sound files 514 , database files 515 , and email files 516 , and/or other information (e.g., registry information, user preference information, etc.) stored on a client device in a file tree structure (e.g., hierarchal database, hierarchal flat file, etc.). The user data backup 520 includes a plurality of files, image files 521 , document files 522 , video files 523 , sound files 524 , database files 525 , and email files 526 , and/or other information that is selected for backup by the user, automatically by the management server (e.g., site management server, data center management server, etc.), and/or based on backup templates and/or backup policies. The technology as described herein can be utilized to backup the user data as the user data backup. Although FIG. 5 illustrates certain types of files (e.g., image files, document files, etc.), the technology as described herein can backup any type of information and/or data stored on the client device and/or a storage device connected to the client device (e.g., external storage device, network connected storage device, etc). FIG. 6 illustrates an exemplary site management server 600 . The site management server 600 includes a communication module 605 , a user authentication module 610 , a backup management module 615 , a user preference module 620 , a backup set management module 625 , an output device 660 , an input device 665 , a processor 670 , and a storage device 675 . The modules and/or devices can be hardware and/or software. The modules and/or devices illustrated in the site management server 600 can, for example, utilize the processor 670 to execute computer executable instructions and/or include a processor to execute computer executable instructions (e.g., an encryption processing unit, a field programmable gate array processing unit, etc.). It should be understood that the site management server 600 can include, for example, other modules, devices, and/or processors known in the art and/or varieties of the illustrated modules, devices, and/or processors. It should be understood that the modules and/or devices illustrated in the site management server 600 can be located within the site management server 600 and/or connected to the site management server 600 (e.g., directly, indirectly, etc.), but outside of the physical components of the management server (e.g., personal computer, mobile device, etc.). The communication module 605 communicates data to/from the site management server 600 . The user authentication module 610 authenticates users to the site management server 600 . The backup management module 615 manages and/or controls backups to/from the site management server 600 . The user preference module 620 manages preferences of users and/or collects information associated with user selections and/or preferences. In some embodiments, the user preference module 620 can modify user's backup sets based on the analysis performed by the backup set management module. In other embodiments, the user preference module 620 can specify backup sets which are disallowed for a given policy. For example, music backup sets can be disallowed during the trial period. The backup set management module 625 analyzes modifications made to backup sets by existing users. In some embodiments, the backup set management module 625 can aggregate backup set modifications made by users. The backup set management module 625 can determine based on this analysis whether to similarly modify default backup sets stored on the management server. A default backup set can include a set of related files aggregated together according to certain pre-determine criteria. The user preference module 620 modifies default backup sets and/or other users backup sets based on the analysis performed by the backup set management module 625 . In one embodiment, the backup set management module 625 can analyze changes made to the backup sets based on rules stored in the storage device 675 . For example, a rule can provide that if a significant number of users (e.g., more than 75%, more than 90% of users associated with a user type, etc.) have added a new file type to their backup sets, the backup set management module 625 can determine that the new file type must be added to the default backup sets stored on the management server. As another example of a rule, if a significant number of users have added a new backup set (e.g., “Architectural Drawings”, “Baby Pictures”, etc.) that is not already one of the default backup sets, the backup set management module 625 can determine that the new backup set is to be added to the list of default backup sets. As an additional example of a rule, if users are changing one of the default backup sets in a similar way, the backup set management module 625 can determine that default backup sets can be modified correspondingly by changing/deleting one of the existing default backup sets or adding a new default backup set. In another embodiment, the backup set management module 625 can determine based on the analysis described above that backup sets of other users need to be updated automatically. In other embodiments, the backup set management module 625 can notify users with recommended modifications to their backup sets (e.g., adding files, updating file information, deleting files, etc.). The output device 660 outputs information and/or data associated with the site management server 600 (e.g., information to a printer (not shown), information to a speaker, etc.). The input device 665 receives information associated with the site management server 600 (e.g., instructions from a user, instructions from a computing device, etc.) from a user (not shown) and/or a computing system (not shown). The input device 665 can include, for example, a keyboard, a scanner, an enrollment device, a scale, etc. The processor 670 executes the operating system and/or any other computer executable instructions for the management server (e.g., executes applications, etc.). The site management server 600 can include random access memory (not shown). The random access memory can temporarily store the operating system, the instructions, and/or any other data associated with the management server. The random access memory can include one or more levels of memory storage (e.g., processor register, storage disk cache, main memory, etc.). The storage device 675 stores the files, user preferences, backup sets, access information, an operating system and/or any other data or program code associated with the site management server 600 . The storage device can include a plurality of storage devices. The storage device 675 can include, for example, long-term storage (e.g., a hard drive, a tape storage device, flash memory, etc.), short-term storage/e.g., a random access memory, a graphics memory, etc.), and/or any other type of computer readable storage. Although FIG. 6 illustrates the exemplary site management server 600 , any of the management servers described herein (e.g., data center management server) can include the components and functionality described with respect to the site management server 600 . FIG. 7 illustrates an exemplary storage server 700 . The storage server 700 includes a data access module 705 , a storage volume management module 710 , a lock management module 715 , a user data backup transfer module 720 , a backend scavenger module 725 , a file check module 730 , an output device 760 , an input device 765 , a processor 770 , and a storage device 775 . The modules and/or devices can be hardware and/or software. The modules and/or devices illustrated in the storage server 700 can, for example, utilize the processor 770 to execute computer executable instructions and/or include a processor to execute computer executable instructions (e.g., an encryption processing unit, a field programmable gate array processing unit, etc.). It should be understood that the storage server 700 can include, for example, other modules, devices, and/or processors known in the art and/or varieties of the illustrated modules, devices, and/or processors. It should be understood that the modules and/or devices illustrated in the storage server 700 can be located within the storage server 700 and/or connected to the storage server 700 (e.g., directly, indirectly, etc.), but outside of the physical components of the management server (e.g., personal computer, mobile device, etc.). The data access module 705 accesses data stored on the storage server 700 . The storage volume management module 710 manages user data storages on a storage volume, a logical data site and/or data center. The lock management module 715 manages locks for locking user data during transfer of user data, maintenance, etc. In some embodiments, the lock management module 715 can manage different types of locks, including a copy lock protecting file copying, an exclusive lock protecting user data from any access to user data, a scavenger lock protecting for read and occasional deletion of expired or corrupt files, a lock protecting user data for reading and writing, a read lock protecting user data for reading, and/or any other type of computer locking mechanism. In some embodiments, the locks can be local to a storage volume, storage server, or logical data site, etc. The user data backup transfer module 720 manages transfer of user data backup between logical data sites and/or data centers. In some embodiments, the user data backup transfer module 720 transfers user data backup from a source logical data site to a destination logical data site which are located in two different data centers. The backend scavenger module 725 deletes files no longer required by the client for backup. In some embodiments, the client device determines when to purge unwanted files, and updates the backup status files accordingly. Using the updated backup status files, the backend scavenger module 725 deletes files from storage volumes. The backend scavenger module 725 purges data for expired computers, deletes obsolete backup files, requests resend of missing files, performs server file integrity checks, aggregates client log files, gathers server file statistics to logs and database, and/or manages free space in the file system (e.g., NTFS, proprietary file system). The file check module 730 deletes invalid files (e.g., expired files, suspended files, etc.). The file check module 730 verifies integrity of server files, gathers computer parameters from database, records activity to logs and database, and/or reads storage volume configurations from database, etc. In some embodiments, the file check module 730 moves invalid files to a predetermined folder on each storage volume, and the backend scavenger module 725 performs the actual deletion of the invalid files. In other embodiments, using a proprietary file system, the file check module 730 marks the invalid files for purging, and the file system internally manages the deletion of files marked for purging. The output device 760 outputs information and/or data associated with the storage server 700 (e.g., information to a printer (not shown), information to a speaker, etc.). The input device 765 receives information associated with the storage server 700 (e.g., instructions from a user, instructions from a computing device, etc.) from a user (not shown) and/or a computing system (not shown). The input device 765 can include, for example, a keyboard, a scanner, an enrollment device, a scale, etc. The processor 770 executes the operating system and/or any other computer executable instructions for the management server (e.g., executes applications, etc.). The storage server 700 can include random access memory (not shown). The random access memory can temporarily store the operating system, the instructions, and/or any other data associated with the management server. The random access memory can include one or more levels of memory storage (e.g., processor register, storage disk cache, main memory, etc.). The storage device 775 stores the files, user preferences, backup sets, access information, an operating system and/or any other data or program code associated with the storage server 700 . The storage device can include a plurality of storage devices. The storage device 775 can include, for example, long-term storage (e.g., a hard drive, a tape storage device, flash memory, etc.), short-term storage (e.g., a random access memory, a graphics memory, etc.), and/or any other type of computer readable storage. Although FIG. 7 illustrates the exemplary storage server 700 , any of the management servers described herein (e.g., site management server) can include the components and functionality described with respect to the storage server 700 . FIG. 8 illustrates an exemplary client device 800 . The client device 800 includes a communication module 805 , a user authentication module 810 , a client backup module 815 , an operating system module 820 , an application module 825 , a client backup set management module 830 , an output device 860 , an input device 865 , a processor 870 , and a storage device 875 . The modules and/or devices can be hardware and/or software. The modules and/or devices illustrated in the client device can, for example, utilize the processor to execute computer executable instructions and/or include a processor to execute computer executable instructions (e.g., an encryption processing unit, afield programmable gate array processing unit, etc.). It should be understood that the client device 800 can include, for example, other modules, devices, and/or processors known in the art and/or varieties of the illustrated modules, devices, and/or processors. It should be understood that the modules and/or devices illustrated in the client device 800 can be located within the client device 800 and/or connected to the client device 800 (e.g., directly, indirectly, etc.), but outside of the physical components of the client device 800 (e.g., personal computer, mobile device, etc.). The communication module 805 communicates data and/or information to/from the client device 800 . The user authentication module 810 authenticates users for the client device 800 and/or the client backup module. The client backup module 815 backs-up, restores and/or identifies user data for backup and restoration. The operating system module 820 operates an operating system on the client device 800 . The application module 825 operates one or more applications on the client device 800 . The client backup set management module 830 manages backup sets stored on the client device. The output device 860 outputs information and/or data associated with the client device 800 (e.g., information to a printer (not shown), information to a speaker, etc.). The input device 865 receives information associated with the client device (e.g., instructions from a user, instructions from a computing device, etc.) from a user (not shown) and/or a computing system (not shown). The input device 865 can include, for example, a keyboard, a scanner, an enrollment device, a scale, etc. The processor 870 executes the operating system and/or any other computer executable instructions for the client device (e.g., executes applications, etc.). The client device 800 can include random access memory (not shown). The random access memory can temporarily store the operating system, the instructions, and/or any other data associated with the client device. The random access memory can include one or more levels of memory storage (e.g., processor register, storage disk cache, main memory, etc.). The storage device 875 stores the files, user preferences, backup sets, access information, an operating system and/or any other data or program code associated with the management server (e.g., site management server, data center management server, etc.). The storage device 875 can include a plurality of storage devices. The storage device 875 can include, for example, long-term storage (e.g., a hard drive, a tape storage device, flash memory, etc.), short-term storage (e.g., a random access memory, a graphics memory, etc.), and/or any other type of computer readable storage. As illustrated in FIG. 9 , each user 905 can be associated with one or more backup policies 910 . For example, a user 905 has multiple client devices and has a separate backup policy for each client device (e.g., home computer backup policy for the user's home computer, personal digital assistant (PDA) backup policy for the user's FDA, mobile device backup policy for the user's mobile device, etc). In other embodiments, users can have multiple backup policies for each client device (e.g., music backup policy and document backup policy for the user's computer, calendar backup policy, contact backup policy, and email backup policy for the user's mobile device, etc.). In some embodiments, each backup policy 910 can include one or more backup sets 915 . A backup set 915 can include a grouping of files according to backup set rules 920 . The backup set rules 920 can include pre-defined criteria (e.g., above a set size, below a set size, etc.) and/or dynamically generated criteria. The pre-defined or dynamically generated criteria can include folder paths (e.g., “C:\users\jdoe\My Movies”), file extensions (e.g., “.mov”), file size specifications (e.g., file size less than 50 MB), file modification date specification (e.g., files modified after Jan. 1, 2009), and/or any other type of pre-defined or dynamically generated parameter. The backup set 915 can be, for example, defined with any combination of these criteria and/or any other information (e.g., other criteria, user inputs, etc.). In some embodiments, one or more folder paths are utilized to define a backup set. The backup policies 910 can be, for example, in binary format, American Standard Code for Information Interchange (ASCII) format, Extensible Markup Language (XML) format, and/or any other format. FIG. 10A illustrates the site management server 1010 storing each user's 1014 , 1024 through 1034 backup policies 1016 , 1026 , through 1036 and backup sets 1018 , 1028 through 1038 . The site management server 1010 can periodically backup the user's backup policies 1016 , 1026 , through 1036 and/or backup sets 1018 , 1028 through 1038 . Each user's backup policies 1016 , 1026 , through 1036 and backup sets 1018 , 1028 through 1038 may also be stored on the user's client devices as illustrated in FIG. 10B . FIG. 10B illustrates an exemplary client device 1070 storing on a storage device 1070 backup policy 1080 and backup sets 1085 . The site management server 1010 can store default or template backup policies 1050 , and default or template backup sets 1055 . In some embodiments, the template backup policies 1050 are managed (e.g., updated, added, deleted, etc.) by the site management server 1010 . The template backup policies 1050 and template backup sets 1055 may be used, for example, for new users or for existing users registering new client devices. In this embodiment, if a new user registers with the backup management system, the new user can be set up to use the template backup policies 1050 and template backup sets 1055 maintained by the site management server 1010 . FIG. 11 illustrates an exemplary backup policy 1115 for user “John Doe”. The backup set policy 1115 includes three exemplary backup sets “Desktop” 1120 , “Movies” 1125 , and “Music” 1130 . These three backup sets may be template backup sets originally created by the site management server 600 . In other embodiments, at least one of the backup sets may have been previously created or modified by the user. The “Desktop” backup set 1120 is defined as including all files in the “C:\users\jdoe\Desktop” folder, except for files in the “old” subfolder. Accordingly, all files in the Desktop folder, except for the files in the “old” subfolder will be backed up by the client backup module. The “Movies” backup set 1125 is defined as including “.mov” and “.wmv” files in the “C:\users\jdoe\My Movies”. Accordingly, for this backup set, all files in the “My Movies” folder with “.mov” and “.wmv” extensions will be backed up by the client backup module. Finally, the third backup set “Music” 1130 includes all “.mva” and “.mp3” files in the “C:\users\jdoe\My Music” folder. For the “Music” backup set 1130 , all files in the “My Music” folder with “.mva” and “.mp3” extensions will be backed up by the client backup module. FIG. 12 illustrates an exemplary backup policy after the user makes modifications to the “Movies” backup set 1125 . In this example, the user adds “.m4v” file format to the “Movies” backup set 1125 . As a result, the updated backup policy 1215 includes a “Movies” backup set 1225 with a “.m4v” file extension included in the list of file extensions. The user may further modify any of the three backup sets 1220 , 1225 , 1230 or create a new backup set. The grouping of files into backup sets can advantageously help users to understand what is and what is not being backed up. Using interfaces as illustrated in the screenshots of FIGS. 12-17 , users can easily tell what files and folders are being backed up. In some embodiments, a user may only realize that a file or folder of interest to the user was not backed up after their computer suffered a disk failure. Accordingly, the user interfaces as illustrated in the screenshots of FIGS. 12-17 advantageously enable the user to proactively correct this issue of files and/or folders not being backed up, thereby increasing the value of the backup system for the user and decreasing the inefficiencies associated with data loss for the user. As discussed herein, the interfaces illustrated in FIGS. 13-18 allow users to view and manage what files and folders are scheduled for backup. FIG. 13 illustrates a screenshot of an interface that allows users to view their backup sets. The interface displays information about backup sets 1310 , such as backup set name 1320 , total number of files 1330 and total size of files 1340 in each backup set. This interface also illustrates which backup sets are selected for backup. The user may use this interface to select and un-select individual backup sets. Additional information about backup sets may be shown to the user including what time each backup set is scheduled for backup, definition criteria for each backup set, etc. In some embodiments, the user can reset all backup set selections to the default backup sets created by the management server. In other embodiments, the default backup sets that do not match any files on the client device may be hidden from the user. In other embodiments, the user can disable any of the backup sets such that files in the disabled backup sets will no longer be backed up. The user's backup sets can consist entirely of default or template backup sets created by the management server. The user can create their own backup sets, modify default or template backup sets, and modify backup sets previously created by the user. In some embodiments, a user clicking on one of the backup sets may show a list of files that are being backed up according to the rules associated with the selected backup set as illustrated in FIG. 14 . For example, the right-side window 1420 in the interface 1400 displays all the files being backed up for the “Word Processing Documents” backup set 1410 . The interface 1400 displays file name 1430 , folder path 1440 , file size 1450 , and file type 1460 of each file included in the “Word Processing Documents” backup set 1410 . Accordingly, users can tell what files are being backed up. If a user notices that certain files or folders are not being backed up, the user may modify an existing backup set to include the files of interest or alternatively create a new backup set and define it such that files or folders of interest will be backed up. Using the interface in FIG. 14 , the user may be able to unselect individual files from being included in a backup set. Unselected individual files may then be viewed in the “Ignore Files/Folders” tab 1470 of the interface 1400 . Users may be able to add the unselected individual files or folders back into the backup set. FIG. 15 illustrates a screenshot of an interface 1500 allowing the user to view a tree 1510 of all folders on a user's client device. To view the tree of all folders 1510 the user clicks on the “File System” tab in the interface 1500 . The interface 1500 displays an indication whether each shown folder is being backed up. In addition, the interface 1500 displays a summary 1530 of quota, total number and total size of files selected for backup. When a user clicks on one of the folders, a list of files contained in the selected folder is shown along with an indication of whether each of those files is being backed up. For example, the user clicking on the “Sample Music” folder 1540 causes the interface to display a list of files 1550 contained in the “Sample Music” folder 1540 . The user may be allowed to select and unselect individual files and folders in this interface such that corresponding backup sets are updated. In some embodiments, when a folder is selected for backup, all of its subfolders and files can be selected for backup. In some embodiments, when a user selects a folder or a file to be backed up that is not included in any of the backup sets of the user, then the selected folder or file may be added to an existing backup set that includes files and folders specifically selected by the user. In other embodiments, a new backup set may be automatically created to include a selected file or folder, and the user can later customize the new backup set. FIG. 16 illustrates a screenshot of an interface 1600 that provides the user with the ability to create new backup sets. The user can create a new backup set by entering a backup set name 1610 , and defining backup set criteria 1660 such as list of folder paths 1620 , list of files extension 1630 , file size specification 1640 , file modification date specification 1650 , etc. The defining backup set criteria 1660 can include excluded folders, excluded files, excluded file types, etc. The defining backup set criteria 1660 can be any combination of the parameters listed above. For example, the user can create a new backup set called “Small Movie Clips” and define it as a set of files of various types, including “.mov” and “.wmv”, where the size of each file must be less than 50 MB. In some embodiments, the interface 1600 enables the user to enter the next backup time as well as how often the new backup set should be backed up. The user can create a new backup set without enabling it for any scheduled backups. In some embodiments, once the user enters the new backup set, the updated list of the user's backup sets is transmitted to the site management server 600 from the client device 800 . In some embodiments, the updated backup sets, including the newly created backup set, is stored on the client device storage 875 . A user can create backup sets that overlap in terms of what files are included in each backup set. The interface 1600 can enable the user to modify an existing backup set. In some embodiments, the user can update any of the defining backup set criteria 1660 . For example, the user can modify the list of file extensions 1630 by adding, removing or updating a file extension. For example, the user can modify the “Small Movie Clips” backup set by adding a new file extension “.m4v” to the list of file extensions 1630 defining this backup set. The user can modify the list of folder paths 1620 by adding, removing or updating one or more folder paths. In addition, the user can modify the size file restriction parameter 1640 and/or the file modification date parameter 1650 . In other embodiments, the interface 1600 can include other criteria defining the backup set not shown in FIG. 16 which the user may be allowed to modify (e.g., backup set description). In other embodiments, the user interface 1600 can include an option to restore the backup sets to defaults. FIG. 17 illustrates an interface 1700 displaying a list of backup sets with color coding blocks (e.g., 1710 , 1720 , 1730 , 1740 ) next to each backup set to inform the user whether selecting a backup set will make the user go over a storage quota limit 1750 . FIG. 17A displays total amount of selected storage 1760 and a percentage bar 1770 indicating percentage of selected storage. As shown, the storage quota 1740 is 10 GB and the total amount of selected storage 1760 is 0 GB. The color coding or other visual symbols may advantageously make it easier for the user to determine whether the quota limit 1750 is close to being reached. As illustrated in FIG. 17 , the color coding technique utilizes boxes next to each backup set, shown in different colors, depending on whether selecting the folder will make the files or folders being backed up as part of the backup set go over the storage quota. In some embodiments, a red box located next to a backup set indicates to the user that backup of this backup set will use up a lot more than 100% of allowed storage quota 1750 . For example, the “Documents” backup set is shown to have a size of 26.5 GB. The “Documents” backup set is marked with a solid red box 1710 next to it, indicating that selecting the “Documents” backup set for backup will put the user well over the allowed storage quota 1750 of 10 GB. In some embodiments, the red box can be partially filled, indicating to the user that the backup for the corresponding backup set would use slightly more than 100% of allowed storage quota 1750 . For example, a “Video” backup set having a size of 10.1 GB has a partially filled red box 1740 next to it indicating that the backup set size is slightly larger than the total allowed storage quota 1750 . In other embodiments, a percentage of a fill of a partially filled box can be proportional to the backup set size. In some embodiments, a backup set that would use 80-100% of the allowed storage quota 1750 can have a yellow box next to it, signifying that the backup set will not put the user over the allowed quota 1750 , but that the user is very close to reaching the quota 1750 . A backup set of a smaller size can have a white or empty box next to it signaling to the user that selecting this folder will not put the user over the quota and there is still space left to further select additional folders or files for backup. For example, the “Finance” folder with a size of 2.5 GB has a box 1720 displayed next it. In some embodiments, the box 1720 can be of white color indicating that the “Finance” backup set uses less than 80% (or any other percentage) of the allowed storage quota 1750 . In other embodiments, other visual indications (e.g., symbols, icon change, etc.) can be used to indicate storage quota usage. The colors of the colored blocks and/or the visual indications may change depending on how much space is left after backup sets are selected, unselected, created, and/or modified. For example, with a 1000 MB quota, a backup set that is 400 MB large would have a white block next to it. However, once the user selects a backup set for backup that is larger than 600 MB, then the white block next to the 400 MB folder can change color (e.g. to red) to signal that the 400 MB backup set can no longer be selected to fit within the allowed storage quota. As illustrated in FIG. 14 , when the user clicks on the backup set “Word Processing Documents”, a list of corresponding files and/or folders is displayed. In some embodiments, the visual indicators such as colored boxed (not shown) can be located next to each file in the right window panel 1420 indicating to the user whether selecting a file will make the user go over a storage quota limit. In FIG. 18 , a flow chart 1800 relating to transfer of data between a client device 1810 and a site management server 1830 is shown, according to an exemplary embodiment. The user authentication module 610 authenticates ( 1812 ) the client device 1810 to the site management server 1830 . In some embodiments, the user's backup policy may be stored on the client device 1810 , in which case the client device 1910 will retrieve the backup policy from its own storage device. In other embodiments, the user's backup policies are stored on the site management server 1830 . In this embodiment, the backup set management module 625 retrieves ( 1832 ) the backup policy for the client device 1810 and sends ( 1914 ) the retrieved backup policy back to the client device 1810 . The user can update their backup sets by creating new backup sets, modifying or deleting ( 1816 ) existing backup sets. In some embodiments, the client backup set management module 830 stores the updated backup sets in the storage device 875 . The client backup set management module 830 transmits ( 1917 ) updated backup sets back to the backup set management module 625 for storage and processing. The backup set management module 625 stores ( 1834 ) the received backup sets in the storage device 675 . FIG. 19 depicts a flow chart 1900 relating to registering a new client device 1910 . When an existing or new user registers the new client device 1910 , the user authentication module 610 authenticates ( 1912 ) and registers ( 1914 ) the new user or new client device 1910 . The backup set management module 625 retrieves ( 1932 ) a set of default backup sets from storage. The set of default backup sets is managed by the backup set management module 625 . As discussed herein, the default backup sets may incorporate aggregated changes made to the backup sets by other users. The backup set management module 625 transmits ( 1916 ) the default backup sets back to the client device 1910 . In some embodiments, the backup set management module 625 transmits a default backup policy to the client device 1910 . The user can modify ( 1918 ) the default backup sets in order to ensure backup of all the files and folders of interest to the user. The client backup set management module 830 manages and stores the updated backup sets on the client device 1910 . The client backup set management module 830 transmits ( 1920 ) the updated backup sets back to the backup set management module 625 and stores the received updated backup sets in the storage device 675 . Based on the changes to the backup sets made by the registered users, the backup set management module 625 can modify the default backup sets and backups sets of other users. FIG. 20 further illustrates a flow chart 2000 relating the site management server 600 analyzing backup sets received from client devices. The backup set management module 625 receives ( 2010 ) updated backup sets from one or more client devices. The backup set management module 625 stores ( 2020 ) received updated backup sets in the storage device 675 or other storage. The backup set management module 625 analyzes ( 2030 ) backup sets associated with one or more client devices. In some embodiments, the backup set management module 625 performs statistical analysis of modifications made by users to their backup sets, and determines whether to modify default or template backup sets based on the results of the analysis. The backup set management module 625 can aggregate modifications that users have made to their backup sets. For example, if a significant number of users (e.g., above a predefined number, above a predefined percentage of users, above a dynamically determined number of users associated with a user type, etc.) add a specific file type to their backup sets, the backup set management module 625 can determine to add this file type to one or more of the default backup sets. This feedback mechanism advantageously enables the backup and restoration process as described herein to learn from the users and distribute the learning to other users for the benefit of all of the users, thereby increasing the efficiency of the backup and restoration process by backing up more files that are important for the users. Based on the analysis performed in step 2030 , the backup set management module 625 updates ( 2040 ) the default backup sets stored on the site management server 600 . In some embodiments, the backup set management module 625 automatically updates ( 2050 ) effected users' backup sets definitions based on other users' backup sets modifications without prompting the effected users. In these embodiments, the backup set management module 625 updates the effected users' backup sets definitions stored on the site management server 600 and transmits modified backup sets to the effected users client devices. For example, the backup set management module 625 determines that the backup sets of the effected users need to be updated with a new file type. The user preference module 620 can modify the users' backup sets based on this determination. In this embodiment, the users may have elected to have automatic updates performed on their backup sets. In some embodiments, if a user has previously made modifications to a backup set which contradict modifications that the management server determined to automatically apply to the user's backup set, then the user may be manually prompted with a dialog indicating that recommended modifications to the user's backup set may be applied by overwriting the user's backup set's definition. In other embodiments, the user's backup set definition may be overwritten without prompting the user. In another embodiment, the backup set management module 625 determines that some critical backup set modifications need to be automatically applied to backup sets of some or all of the users, while for less critical backup sets modifications, the users may be manually prompted. In these embodiments, the users who accept recommended modifications or elect to have their backup sets automatically updated may advantageously benefit from other users' backup set modifications. For instance, some users may be using a new video file format (e.g., “.m4v”) without having their backup sets updated with the new video file format. A large number of other users adding the new video file format to their backup sets may trigger the backup set management module 625 to update default backups sets as well as effected users' backup sets with this new video file format. In some embodiments, the effected users are prompted whether they would like to update their backup sets with the backup sets changes recommended by the management server. Accordingly, each effected user may advantageously benefit from the feedback that the site management server 600 has received from other users about their backup sets. For example, one of the recommended changes may be to add the “.m4v” file format to one or more backup sets. The user may decide to ignore the recommended modifications to the user's backup sets. The user may also elect not to receive any future recommendations to update backup sets based on backup set changes implemented by other users. In other embodiments, the users are only prompted when updates recommended by the backup set management module 625 conflict with users' previous updates to their backup sets. In these embodiments, the users may receive an indication that recommended backup sets updates can only be applied by overwriting their backup sets' definitions. In other embodiments, a user may elect not to allow the site management server 600 analyze changes made by the user to the user's backup sets. In this embodiment, the client device 800 may still transmit to the site management server 600 the modified backup sets for storage and backup, but the site management server 800 will not analyze the changes made by the user. In another embodiment, a user may elect not to receive any recommendations or automatic updates to their backup sets based on changes made by the other users to their backup sets. In other embodiments, the backup set management module 625 analyzes whether users are accepting recommended changes to their backup sets. Based on this analysis, the backup set management module 625 can determine whether to further modify template or default backup sets maintained by the backup set management module 625 . The default backup sets may be used for new users or for existing users registering new client devices. The backup set management module 625 may also revert changes previously made to users' backup sets. The above-described systems and methods can be implemented in digital electronic circuitry, in computer hardware, firmware, and/or software. The implementation can be as a computer program product (i.e., a computer program tangibly embodied in an information carrier). The implementation can, for example, be in a machine-readable storage device, for execution by, or to control the operation of, data processing apparatus. The implementation can, for example, be a programmable processor, a computer, and/or multiple computers. A computer program can be written in any form of programming language, including compiled and/or interpreted languages, and the computer program can be deployed in any form, including as a stand-alone program or as a subroutine, element, and/or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site. Method steps can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Method steps can also be performed by and an apparatus can be implemented as special purpose logic circuitry. The circuitry can, for example, be a FPGA (field programmable gate array) and/or an ASIC (application-specific integrated circuit). Modules, subroutines, and software agents can refer to portions of the computer program, the processor, the special circuitry, software, and/or hardware that implements that functionality. Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor receives instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer can include, can be operatively coupled to receive data from and/or transfer data to one or more mass storage devices for storing data (e.g., magnetic, magneto-optical disks, or optical disks). Data transmission and instructions can also occur over a communications network. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices. The information carriers can, for example, be EPROM, EEPROM, flash memory devices, magnetic disks, internal hard disks, removable disks, magneto-optical disks, CD-ROM, and/or DVD-ROM disks. The processor and the memory can be supplemented by, and/or incorporated in special purpose logic circuitry. To provide for interaction with a user, the above described techniques can be implemented on a computer having a display device. The display device can, for example, be a cathode ray tube (CRT) and/or a liquid crystal display (LCD) monitor. The interaction with a user can, for example, be a display of information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer (e.g., interact with a user interface element). Other kinds of devices can be used to provide for interaction with a user. Other devices can, for example, be feedback provided to the user in any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback). Input from the user can, for example, be received in any form, including acoustic, speech, and/or tactile input. The above described techniques can be implemented in a distributed computing system that includes a back-end component. The back-end component can, for example, be a data server, a middleware component, and/or an application server. The above described techniques can be implemented in a distributing computing system that includes a front-end component. The front-end component can, for example, be a client computer having a graphical user interface, a Web browser through which a user can interact with an example implementation, and/or other graphical user interfaces for a transmitting device. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), the Internet, wired networks, and/or wireless networks. The system can include clients and servers. A client and a server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. Packet-based networks can include, for example, the Internet, a carrier internet protocol (IP) network (e.g., local area network (LAN), wide area network (WAN), campus area network (CAN), metropolitan area network (MAN), home area network (HAN)), a private IP network, an IP private branch exchange (IPBX), a wireless network (e.g., radio access network (RAN), 802.11 network, 802.16 network, general packet radio service (GPRS) network, HiperLAN), and/or other packet-based networks. Circuit-based networks can include, for example, the public switched telephone network (PSTN), a private branch exchange (PBX), a wireless network (e.g., RAN, Bluetooth, code-division multiple access (CDMA) network, time division multiple access (TDMA) network, global system for mobile communications (GSM) network), and/or other circuit-based networks. The client device can include, for example, a computer, a computer with a browser device, a telephone, an IP phone, a mobile device (e.g., cellular phone, personal digital assistant (FDA) device, laptop computer, electronic mail device), and/or other communication devices. The browser device includes, for example, a computer (e.g., desktop computer, laptop computer) with a world wide web browser (e.g., Microsoft® Internet Explorer® available from Microsoft Corporation, Mozilla® Firefox available from Mozilla Corporation). The mobile computing device includes, for example, a personal digital assistant (PDA). Comprise, include, and/or plural forms of each are open ended and include the listed parts and can include additional parts that are not listed. And/or is open ended and includes one or more of the listed parts and combinations of the listed parts. As used in this application, the terms “component,” “module,” “system,” and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, an integrated circuit, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal). Moreover, various functions described herein can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media can be non-transitory in nature and can include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any physical connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc (BD), where disks usually reproduce data magnetically and discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, in the subject description, the word “exemplary” is used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word exemplary is intended to present concepts in a concrete manner. One skilled in the art will realize the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

The management of backup sets based on user feedback techniques include a method, and a system. In some embodiments of these techniques, the method includes receiving an update to a backup set from a first client device. The method further includes analyzing the update made to the backup set. The method further includes updating a default backup set stored in a storage device based on the update to the backup set. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

BACKGROUND [0001] 1. Field of the Invention [0002] The present invention relates to a manufacturing method for an integrated semiconductor structure and to a corresponding semiconductor structure. [0003] 2. Description of the Related Art [0004] Although applicable to arbitrary integrated semiconductor structures, the following invention and the underlying problems will be explained with respect to integrated DRAM memory circuits in silicon technology. In particular, DRAM technology which is scaled down to below 100 nm generation provides big challenges. [0005] Phospho-silicate glass (PSG) is used to getter mobile ions (Li, Na, K) and metal contaminants in semiconductor structures, because these elements which are still present in today's semiconductor structures deteriorate the electrical functions thereof. [0006] FIG. 5 shows a schematic layout for illustrating a known manufacturing method for an integrated semiconductor structure according. [0007] In FIG. 5 reference sign 1 denotes a semiconductor substrate having a (not shown) integrated circuitry, e.g. a DRAM-circuitry, and having a main surface OS with a non-planar topology. In this particular case, a plurality of gate lines G is arranged in parallel on the main surface OS, said gate lines G having a certain distance from each other and leaving spaces therebetween. Up to now a phospho-silicate glass layer PGL was deposited on such a semiconductor structure with non-planar topology as a getter layer and a planarizing layer. [0008] However, as indicated with reference sign L in FIG. 5 , due to the poor gap fill of PSG, in particular in low thermal budget process flows, unwanted voids L are formed in the spaces between the gate lines G. This makes it necessary to look for alternative gap fill materials, such as spin-on dielectrics with exhibit much better gap flow. However, these spin-on dielectrics, e.g. polysilacane based spin-on dielectrica, are usually not phosphorous doped or cannot easily be doped with phosphorous. SUMMARY [0009] According to one aspect of the invention as claimed in claim 1 , a manufacturing method for an integrated semiconductor structure comprises the steps of: providing a semiconductor substrate with a main surface; forming a wiring metal layer above said main surface; forming a doped getter layer on said wiring metal layer; and forming at least one additional wiring metal layer on said doped getter layer. [0010] According to another aspect of the present invention as claimed in claim 23 , an integrated semiconductor structure comprises: a semiconductor substrate with a main surface; wiring metal layer formed above said main surface; a doped getter layer formed on said wiring metal layer; and at least one additional wiring metal layer formed on said doped getter layer. [0011] According to another aspect of the present invention as claimed in claim 39 , a semiconductor memory device comprises: [0012] a semiconductor substrate having a main surface including a plurality of non-planar gate stacks; a planarization layer for planarizing said gate stacks; a wiring metal layer formed in or on said planarization layer; an interlevel insulating layer formed on said wiring metal layer; a doped getter layer formed on said interlevel insulating layer; and at least one additional wiring metal layer formed on said doped getter layer. [0013] One advantage of the proposed implementation is that any underlying layer may be chosen without paying attention to gettering effects thus e.g. avoiding planarizing deficites of gettering material layers. [0014] Preferred embodiments are listed in the respective dependent claims. DESCRIPTION OF THE DRAWINGS [0015] In the Figures: [0016] FIG. 1 a )- d ) show schematic layouts for illustrating a manufacturing method for an integrated semiconductor structure according to a first embodiment of the present invention; [0017] FIG. 2 shows a schematic layout for illustrating a manufacturing method for an integrated semiconductor structure according to a second embodiment of the present invention; [0018] FIG. 3 a )- c ) show schematic layouts for illustrating a manufacturing method for an integrated semiconductor structure according to a third embodiment of the present invention; [0019] FIG. 4 shows a schematic layout for illustrating a manufacturing method for an integrated semiconductor structure according to a fourth embodiment of the present invention; and [0020] FIG. 5 shows a schematic layout for illustrating a known manufacturing method for an integrated semiconductor structure according. [0021] In the Figures, identical reference signs denote equivalent or functionally equivalent components. DETAILED DESCRIPTION [0022] FIG. 1 a )- d ) show schematic layouts for illustrating a manufacturing method for an integrated semiconductor structure according to a first embodiment of the present invention. [0023] In FIG. 1 a ) reference sign 1 denotes a semiconductor substrate having a (not shown) integrated circuitry, e.g. a DRAM-circuitry, and having a main surface OS with a non-planar topology. In this particular case, a plurality of gate lines G is arranged in parallel on the main surface OS, said gate lines G having a certain distance from each other and leaving spaces therebetween. [0024] In this first embodiment, a spin-on glass layer SOL is used as a planarization and gap fill layer which exhibits excellent property regarding gap fill and essentially exhibits no unwanted voids. However, this spin-on glass layer SOL does not contain any getter material such as phosphorous. [0025] On top of the spin-on glass layer SOL, a lowest level wiring metal layer MO is deposited and structured, e.g. a tungsten layer, by masking and etching process steps. [0026] In a next process step which is shown in FIG. 1 b ) an LPCVD-oxide base layer BL is deposited on the lowest level wiring metal layer MO and the exposed parts of the spin-on glass layer SOL. Then, an interlevel insulating layer ILD 0 in form of a low-K dielectric layer is deposited on the LPCVD-oxide base layer BL. The interlevel insulating layer ILD 0 forms a planar surface, and after deposition of layer ILD 0 , a phospho-silicate glass getter layer GL is deposited over the entire structure in a gas-phase doping deposition step. [0027] In a subsequent process step which is shown in FIG. 1 c ) a (not shown) hard mask, e.g. made of carbon, is formed on top of the structure of FIG. 1 b ), said hard mask layer having openings at the position of electrical contacts K to be formed at this process state. Then, using the hard mask, contact holes KH are etched which extend through the getter layer GL and the interlevel insulating layer ILD 0 down to regions of the lowest level wiring metal layer MO to be contacted. Subsequently, tungsten is deposited over the entire structure and polished back to the upper surface of the getter layer GL in order to reach the process state shown in FIG. 1 c ) showing said contacts K in said contact holes KH. [0028] Then, as shown in FIG. 1 d ) a second level wiring metal layer M 1 made of TiN is deposited and structured by known processes. Finally, another interlevel insulating layer ILD 1 is deposited over the second level wiring metal layer M 1 which leads to the process state shown in FIG. 1 d ). [0029] In the semiconductor structure shown in FIG. 1 d ), the phospho-silicate glass getter layer GL is arranged above the lowest level wiring layer M 0 and has no longer any influence regarding the gap fill properties arising in connection with the non-planar topology of the underlying semiconductor structure 1 , G. [0030] Although described here as pure phospho-silicate glass layer, it is of course possible to have a mixed layer such as a boro-phospho-silicate glass layer, typically with a phosphorous content between 0.01%-10% by weight. Even though the mentioned phosphorous content may be advantageous it is only an example and other contents may be possible. [0031] FIG. 2 shows a schematic layout for illustrating a manufacturing method for an integrated semiconductor structure according to a second embodiment of the present invention. [0032] According to the second embodiment shown in FIG. 2 , the process state of which essentially corresponds to the process state shown in FIG. 1 d ), an adhesive layer AL is deposited on the getter layer GL after formation thereof and before formation of the contacts K. This adhesive layer AL is for example an undoped silane-oxinitride (SiON) layer which also acts as a diffusion barrier against unwanted external ions coming from above. This is beneficial, because the getter layer GL shows the tendency to be saturated after having received a certain amount of foreign ions to be gettered. [0033] FIG. 3 a )- c ) show schematic layouts for illustrating a manufacturing method for an integrated semiconductor structure according to a third embodiment of the present invention. [0034] The process state shown in FIG. 3 a ) corresponds to the process state shown in FIG. 1 b ), except for the following differences. [0035] Namely, in this third embodiment, the interlevel insulating layer ILD 0 is a high-density plasma-oxide layer which after deposition shows a non-planar surface. After deposition of this interlevel insulating layer ILD 0 , a getter layer GL′ made of phospho-silicate glass is deposited over the non-planar surface of the interlevel insulating layer ILD 0 and thereafter polished back in chemical-mechanical polishing step, so as to reach the process state shown in FIG. 3 a ). [0036] The contact K formation step shown in FIG. 3 b ) corresponds to the contact K formation step described in connection with FIG. 1 c ). [0037] Also, the second level wiring metal layer M 1 formation step shown in FIG. 3 c ) corresponds to the steps described already with reference to FIG. 1 d ). [0038] FIG. 4 shows a schematic layout for illustrating a manufacturing method for an integrated semiconductor structure according to a fourth embodiment of the present invention. [0039] According to the fourth embodiment, the getter layer GL′ is deposited without any doping on the interlevel insulating layer ILD 0 , e.g. as pure silicate-glass. Thereafter and before formation of the contacts K an ion-implantation step for implanting phosphorous ions into the getter layer GL′ is performed. The parameters of this ion-implantation step are chosen such that a roughening of a surface area of the getter layer GL′ is effected which improves the adhesion to the second level wiring metal layer M 1 and allows omission of the adhesion layer described in connection with the second embodiment shown in FIG. 2 . [0040] However, it is possible as well to additionally add said adhesion layer to the embodiment shown in FIG. 4 which further improves the adhesion of the second level wiring metal layer M 1 and exhibits the aforementioned diffusion barrier function against foreign ions penetrating from above. [0041] Although the present invention has been described with reference to a preferred embodiment, it is not limited thereto, but can be modified in various manners which are obvious for a person skilled in the art. Thus, it is intended that the present invention is only limited by the scope of the claims attached herewith. [0042] Although not shown here, the lowest level metal wiring layer M 0 and corresponding interlevel insulating layer ILD 0 can be formed in damascene-level type, i.e. metal and interlevel dielectric extend to the same upper height. [0043] Such a damascene technique would be performed by forming a insulating layer on said main surface, etching trenches in said insulating layer, depositing said wiring metal layer above said trenched insulating layer, and planarizing said wiring metal layer such that it only remains in said trenches. [0044] Moreover, said metal layers can be any level metal layers. [0045] Moreover, if necessary, the getter layer can be annealed immediately after its formation, especially if the getter layer is implanted with phosphorous ions after its deposition. [0046] Moreover, said interlevel insulating layer ILD 0 could comprise a HDP oxide layer and a TEOS layer deposited thereon. If the underlying structure is non-planar said TEOS layer could be planarized in a planarizing step before the getter layer is deposited thereon.

The present invention provides a manufacturing method for an integrated semiconductor structure comprising the steps of: providing a semiconductor substrate with a main surface; forming a wiring metal layer above said main surface; forming a doped getter layer on said wiring metal layer; and forming at least one additional wiring metal layer on said doped getter layer. The present invention also provides a corresponding integrated semiconductor structure and a semiconductor memory device.

BACKGROUND [0001] One type of web proxy product accelerates clients' access to web content via web caching. In general, these products cache web objects that were returned to clients, and use those cached objects for subsequent client requests, thereby saving the expense of making additional calls to the web server that provides the content. [0002] However, sometimes when a requested object exists in the cache, the object is not valid to be served as a result of it being too old, as indicated by a timestamp. In this manner, users are protected against being served content that is obsolete, as generally determined by the website designer, e.g., a news site may only allow certain content to be considered valid in a cache for a few minutes, whereas a page that is changed weekly may allow its objects to be cached until the next weekly change. [0003] When an object is too old, the web proxy performs a “freshness” check, by sending a special HTTP request to the web server. If the object is still valid, the server returns a new timestamp for the object, otherwise the server returns the entire object that has changed. The process of freshness checking and possible object downloading to update the cache can be time consuming, particularly in high latency situations in which the connection between the web proxy and remote web server is slow. SUMMARY [0004] This Summary is provided to introduce a selection of representative concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used in any way that would limit the scope of the claimed subject matter. [0005] Briefly, various aspects of the subject matter described herein are directed towards a technology by which a web proxy server performs freshness checks on its cached objects, independent of any client requests, whereby the cache contains objects that have a greater likelihood of being fresh when requested by a client. By evaluating data in a web cache data structure to determine whether content in a web cache corresponding to that data is still valid, and sending a freshness check to a web server when the content is not valid, the cache is kept up to date. The scanning may be periodic or on some other triggering event, and all of the cache's corresponding entries may be scanned, or some smaller subset thereof. [0006] In one example implementation, a web proxy server that receives requests from a client for content directed towards a web server includes a freshness check mechanism. The freshness check mechanism evaluates the web proxy server's cached content, and updates the cache with new content (or new freshness data) when invalid content is found in the cache. As a result, the cache, which is used for serving cached content in response to client requests, is updated independent of a pending client request for that content. [0007] Other advantages may become apparent from the following detailed description when taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0008] The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which: [0009] FIG. 1 shows an illustrative example of a network having a web proxy server with proactive freshness checking. [0010] FIG. 2 is a flow diagram representing example steps taken by a web proxy server to check cached objects for freshness. [0011] FIG. 3 shows an illustrative example of a general-purpose network computing environment into which various aspects of the present invention may be incorporated. DETAILED DESCRIPTION [0012] Various aspects of the technology described herein are generally directed towards increasing useful cache hits in a web proxy server by proactively working to keep cached content valid, rather than reactively in response to a client request. This eliminates or dramatically reduces the number of times the web proxy server needs to perform a freshness check on behalf of a waiting client. [0013] In one example implementation, a freshness checking mechanism of the web proxy server operates in the background, actively scanning the objects stored in the cache engine looking for invalid objects. However, rather than performing an active scan of all objects, it is alternatively feasible to have other triggers, and/or to configure a scanner in numerous ways. For example, a data structure that contains information on the cached objects may be sorted into an event list, with an event that triggers a freshness check on only those objects that have timestamps indicating a freshness check is needed. Alternatively, the objects may be sorted into subsets that are scanned at different frequencies depending on their timestamps, e.g., check one subset every minute, check another subset every half-hour, check another subset every day. [0014] Thus, as will be understood, the technology described herein is not limited to any type of configuration, any type of looping model or any type of event driven model. As such, the present invention is not limited to any particular embodiments, aspects, concepts, structures, functionalities or examples described herein. Rather, any of the embodiments, aspects, concepts, structures, functionalities or examples described herein are non-limiting, and the present invention may be used various ways that provide benefits and advantages in computing and accessing network content in general. [0015] Turning to FIG. 1 , there is shown an example network configuration in which clients 102 1 - 102 n issue requests for content to a web server 110 . A web proxy server 120 (e.g., an edge server such as an Internet Security and Acceleration, or ISA Server available from Microsoft Corporation), receives the requests from the clients 102 1 - 102 n . The clients 102 1 - 102 n may have no knowledge of the presence of the web proxy server 120 , that is, the web proxy server is transparent, although it is feasible to have one or more of the clients 102 1 - 102 n make requests to the web proxy server 120 to perform some operation on behalf of the clients 102 1 - 102 n . [0016] When the web proxy server 120 first receives a web request from the client (e.g., 102 1 ), a request/response handler 122 in the web proxy server 120 searches a local cache 124 data structure 124 to see if the requested content is cached and still valid. If so, the content (e.g., a main page or an embedded object described thereon) is returned from the cache 126 . If not, a freshness check is sent to the web server, to either obtain an updated object or a new timestamp that verifies the object is still valid. This aspect is conventional caching for efficiency purposes. [0017] Rather than wait for a client request before determining whether requested content is valid, the web proxy server 120 includes a freshness check mechanism 128 that operates (without waiting for a client request) to update any invalid objects in the cache 126 , either with a new object and associated metadata in the cache data structure 124 , or by updating the data structure 124 with changed metadata, including a timestamp indicating the object is still valid. As a result, (and depending on frequency of checking), most objects in the cache 126 are fresh, and can be served from the cache 126 without the need to perform a freshness check while the user is waiting. [0018] Note that what is considered “invalid” need not be the same as actually invalid. For example, if a scan is performed every five minutes, and an object is going to be invalid before the next scan, that object can be considered invalid for purposes of freshness checking. However, the web server may return the same timestamp, in which event the freshness check request is inefficient, and thus a balance between various factors such as scanning frequency, web request latency, client demands and so forth may help decide on whether to consider an almost invalid object as being invalid with respect to sending a freshness check. [0019] Turning to FIG. 2 , the exemplified freshness check mechanism 128 in the web proxy server 120 scans each of the entries (step 202 ) in the cache data structure 124 looking for invalid entries (step 204 ). Note that there may be several data structures and/or ways of viewing the data within such a data structure (e.g., by ordering, filtering and/or sorting) that can make this scanning action more efficient. For example, ordering the data structure from the soonest to expire (first) and the longest to expire (last) will send freshness checks in an order that may be more efficient. As another example, ordering and grouping the entries by timestamp can allow selection of a range or ranges of invalid or possibly invalid entries, eliminating the need to individually check the timestamps of known valid entries. Further, HTTP pipelining techniques or the like may be used to efficiently check the status of several web objects at the same time. [0020] Once an invalid entry is detected at step 204 , the web proxy initiates a “standard” freshness check at step 206 . If a new object and accompanying metadata is returned (step 208 ), the object is added to the cache at step 210 , and the cache data structure (or possibly multiple data structures) updated at step 214 with the changed metadata. Otherwise metadata alone is returned (step 212 ), whereby the cache data structure is updated at step 214 , including to contain the new timestamp. Note that error conditions are not described herein for purposes of simplicity, however it can be understood that retries may be sent following the “no” branch of step 212 , and objects and/or metadata that are still not found can be removed from the cache. [0021] Further, it should be noted that the proactive freshness check initiated by the freshness check mechanism 128 is not considered a client request with respect to maintaining the information in the cache. More particularly, because of size limitations, cache management systems remove an object based on when the object was last requested, whereby the cache maintains more recently requested objects over those not requested for some time. Thus, an object request initiated from the freshness check mechanism 128 is not considered as being a client request for that object, otherwise the cache management system would be unable to distinguish which objects are to be kept in the cache based on a recently requested priority. [0022] Step 216 represents delaying, such as to periodically repeat the scan rather than continuously scan. Depending on the scanning frequency, the background freshness checking mechanism may dramatically reduce the number of times a cache entry is requested but it is found to be invalid. Note that the scanning frequency need not be periodic, but can be repeated on any appropriate basis, such as based upon how many users are presently sending web requests, how many entries are in the cache, how quickly or slowly web requests are being handled, and/or virtually any other measurable criteria. [0023] Moreover, as described above, all cache entries may be scanned per scanning process, or a scanning process may alternatively only scan a subset of entries. For example, the timestamps may be used to group entries into subsets so that only entries that have a possibility of being invalid during a scan need to be evaluated. Exemplary Operating Environment [0024] FIG. 3 illustrates an example of a suitable computing system environment 300 on which the web proxy server 120 ( FIG. 1 ) or 121 ( FIG. 2 ) may be implemented, for example. The computing system environment 300 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 300 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 300 . [0025] The invention is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the invention include, but are not limited to: personal computers, server computers, hand-held or laptop devices, tablet devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. [0026] The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in local and/or remote computer storage media including memory storage devices. [0027] With reference to FIG. 3 , an exemplary system for implementing various aspects of the invention may include a general purpose computing device in the form of a computer 310 . Components of the computer 310 may include, but are not limited to, a processing unit 320 , a system memory 330 , and a system bus 321 that couples various system components including the system memory to the processing unit 320 . The system bus 321 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus. [0028] The computer 310 typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by the computer 310 and includes both volatile and nonvolatile media, and removable and non-removable media. By way of example, and not limitation, computer-readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by the computer 310 . Communication media typically embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of the any of the above should also be included within the scope of computer-readable media. [0029] The system memory 330 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 331 and random access memory (RAM) 332 . A basic input/output system 333 (BIOS), containing the basic routines that help to transfer information between elements within computer 310 , such as during start-up, is typically stored in ROM 331 . RAM 332 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 320 . By way of example, and not limitation, FIG. 3 illustrates operating system 334 , application programs 335 , other program modules 336 and program data 337 . [0030] The computer 310 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 3 illustrates a hard disk drive 341 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 351 that reads from or writes to a removable, nonvolatile magnetic disk 352 , and an optical disk drive 355 that reads from or writes to a removable, nonvolatile optical disk 356 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 341 is typically connected to the system bus 321 through a non-removable memory interface such as interface 340 , and magnetic disk drive 351 and optical disk drive 355 are typically connected to the system bus 321 by a removable memory interface, such as interface 350 . [0031] The drives and their associated computer storage media, described above and illustrated in FIG. 3 , provide storage of computer-readable instructions, data structures, program modules and other data for the computer 310 . In FIG. 3 , for example, hard disk drive 341 is illustrated as storing operating system 344 , application programs 345 , other program modules 346 and program data 347 . Note that these components can either be the same as or different from operating system 334 , application programs 335 , other program modules 336 , and program data 337 . Operating system 344 , application programs 345 , other program modules 346 , and program data 347 are given different numbers herein to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 310 through input devices such as a tablet, or electronic digitizer, 364 , a microphone 363 , a keyboard 362 and pointing device 361 , commonly referred to as mouse, trackball or touch pad. Other input devices not shown in FIG. 3 may include a joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 320 through a user input interface 360 that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 391 or other type of display device is also connected to the system bus 321 via an interface, such as a video interface 390 . The monitor 391 may also be integrated with a touch-screen panel or the like. Note that the monitor and/or touch screen panel can be physically coupled to a housing in which the computing device 310 is incorporated, such as in a tablet-type personal computer. In addition, computers such as the computing device 310 may also include other peripheral output devices such as speakers 395 and printer 396 , which may be connected through an output peripheral interface 394 or the like. [0032] The computer 310 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 380 . The remote computer 380 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 310 , although only a memory storage device 381 has been illustrated in FIG. 3 . The logical connections depicted in FIG. 3 include one or more local area networks (LAN) 371 and one or more wide area networks (WAN) 373 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. [0033] When used in a LAN networking environment, the computer 310 is connected to the LAN 371 through a network interface or adapter 370 . When used in a WAN networking environment, the computer 310 typically includes a modem 372 or other means for establishing communications over the WAN 373 , such as the Internet. The modem 372 , which may be internal or external, may be connected to the system bus 321 via the user input interface 360 or other appropriate mechanism. A wireless networking component 374 such as comprising an interface and antenna may be coupled through a suitable device such as an access point or peer computer to a WAN or LAN. In a networked environment, program modules depicted relative to the computer 310 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 3 illustrates remote application programs 385 as residing on memory device 381 . It may be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. [0034] An auxiliary subsystem 399 (e.g., for auxiliary display of content) may be connected via the user interface 360 to allow data such as program content, system status and event notifications to be provided to the user, even if the main portions of the computer system are in a low power state. The auxiliary subsystem 399 may be connected to the modem 372 and/or network interface 370 to allow communication between these systems while the main processing unit 320 is in a low power state. CONCLUSION [0035] While the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.

Described is a technology by which a web proxy server evaluates its cached objects, and when an object is invalid, performs a freshness check on that object, independent of any client requests. As a result, the cache contains objects that have a greater likelihood of being fresh when requested by a client. By scanning a web cache data structure to determine whether corresponding cached content is still valid, and sending a freshness check to a web server when the content is not valid, the cache is kept up to date. The scanning may be periodic or based upon some other triggering event, and all of the cache's corresponding entries may be scanned, or some smaller subset of the entries. In one example implementation, a web proxy server that contains the cache includes a freshness check mechanism that scans and keeps the cached objects up to date.

CLAIM OF PRIORITY FROM A COPENDING PROVISIONAL PATENT APPLICATION Priority is herewith claimed under 35 U.S.C. §119(e) from copending Provisional Patent Application Ser. No. 60/025,682, filed Sep. 9, 1996, entitled "Methods and Apparatus for Performing Automatic Mode Selection in a Multimode Terminal", by Marko Kukkohovi. The disclosure of this Provisional Patent Application is incorporated by reference herein in its entirety. FIELD OF THE INVENTION This invention relates generally to radiotelephones and, in particular, to radiotelephones or mobile terminals such as those capable of operation with a cellular network. BACKGROUND OF THE INVENTION A multimode mobile terminal, such as a radiotelephone or personal communicator, is capable of operating in more than one system. By example, and for a dual mode mobile terminal, the modes may be a digital cellular mode (e.g., GSM or DCS1900) and an analog cellular mode (e.g., IS-41 (AMPS)). As can be appreciated, it is important that a multimode mobile terminal be capable of automatically switching between the available operating modes when conditions warrant. Some types of known networks do provide for inter-network roaming (e.g., DAMPS/AMPS). Reference can be had to a publication entitled "Implementation Guide: Non-Public Mode Operation and Selection in IS-136 Compliant Mobile Stations", Version 2.0, TDMA Forum, Mar. 9, 1995. It can thus be appreciated that the capability to switch between networks becomes especially important when the terminal operates with networks that do not support inter-network roaming (e.g., DCS1900 and AMPS). One technique has been proposed in a publication entitled "Inter-Network Roaming Selection", North American Interest Group (NAIG) of the GSM MoU, Jun. 21, 1996 (Ericsson). This publication describes a limited PCS1900/AMPS solution using a systems priority list, wherein a handset moves from the digital network (PCS1900) to the analog network (AMPS). However, this proposal does not provide full, bidirectional mode selection, in that no provision is made to automatically move from the analog network back to the digital network. Also of interest in this area are U.S. Pat. No. 5,504,803, entitled "Method for Automatic Mode Selection for a Dual-Mode Telephone Handset for use in a Cellular Mobile Telephone System and in a Wireless Telephone System", by Yamada et al., and U.S. Pat. No. 4,916,728, entitled "Cellular Telephone Unit with Prioritized Frequency Acquisition", by Blair. OBJECTS OF THE INVENTION It is thus a first object of this invention to provide an improved method for performing automatic mode selection with a multimode user terminal when operating with networks that do not support inter-network roaming. It is a further object of this invention to provide a multimode user terminal that includes at least three master control systems, specifically a primary system controller, a secondary system controller, and a multimode controller, wherein the multimode controller is capable of bidirectionally exchanging control messages and status messages with the primary and secondary system controllers for freely switching the state of the terminal between the primary and secondary systems, wherein the primary and secondary systems do not support inter-network roaming. SUMMARY OF THE INVENTION This invention provides methods to implement an automatic mode selection in a multimode terminal using properties already found in existing networks, the multimode terminal being a device capable of connecting to different networks of different systems of a type that do not support inter-network roaming. If the current network coverage is not adequate to provide reliable communications, e.g., the signal is too weak or missing, the terminal is enabled to access another network in another system without user intervention. The automatic mode selection may be canceled through the user interface of the terminal, and no automatic mode selection is then performed. The networks can be arranged in an ordered or prioritized list that is stored in the terminal. The list can be provided by a specific system operator, or can be provided by the user through the user interface. Since the mode selection is based on the stored priority list, the best possible selectable network is typically always active. The terminal periodically checks or scans for the presence of any networks which are listed earlier in the ordered list than the current network. That is, the terminal automatically scans for the presence of higher priority networks. If such a network is detected, the terminal automatically changes the mode and connects to the preferred and available network. When the method is implemented in a multimode terminal, the terminal can change modes transparently to a user. The selectable modes can be arranged in an ordered list and the terminal then chooses the best mode available based on this list. So when a mode change is needed the networks are checked in the order of the list. From the user's point of view, the terminal is in a preferred mode, if possible, and if not possible, then the mode is selected based on the list arranged by the user or prearranged by the operator. Although described primarily in the context of a dual mode terminal, the teachings of this invention can be readily extended to three mode and higher terminals. BRIEF DESCRIPTION OF THE DRAWINGS The above set forth and other features of the invention are made more apparent in the ensuing Detailed Description of the Invention when read in conjunction with the attached Drawings, wherein: FIG. 1 is a block diagram of a mobile terminal that is constructed and operated in accordance with this invention; FIG. 2 is an elevational view of the mobile terminal shown in FIG. 1, and which further illustrates a cellular communication system to which the mobile terminal is bidirectionally coupled through wireless RF links; FIG. 3 is a logic flow diagram illustrating one embodiment of a method for performing automatic mode selection in a multimode terminal; FIG. 4 illustrates the flow of signalling messages between a dual-mode controller and primary and secondary system controllers for a case where primary service is terminated; and FIG. 5 illustrates in greater detail the flow of signalling messages for executing a primary scan mode when operating in the secondary system. DETAILED DESCRIPTION OF THE INVENTION Reference is made to FIGS. 1 and 2 for illustrating a wireless user terminal or mobile terminal 10, such as but not limited to a cellular radiotelephone or a personal communicator, that is suitable for practicing this invention. The mobile terminal 10 includes an antenna 12 for transmitting signals to and for receiving signals from a first base site or base station 30. The base station 30 is a part of a first cellular network comprising a Base Station/Mobile Switching Center/Internetworking function (BMI 1 ) 32 that includes a mobile switching center (MSC) 34. The MSC 34 provides a connection to landline trunks when the mobile terminal 10 is involved in a call. FIG. 2 also shows a second BMI 2 32', having associated base station(s) 30' and MSC 32'. By example, the BMI 1 32 may be a digital system (e.g., DCS1900 or GSM), and the BMI 2 32' may be an analog system (e.g., IS-41) or another digital system. One of the systems is considered the preferred or primary system (typically the digital system), while the other system is considered the secondary system. The mobile terminal 10 will attempt to use the primary system when possible. This invention provides a mechanism for the mobile terminal 10 to switch between the primary and secondary systems in an automatic and user-transparent manner. It is assumed that the two systems do not support inter-network roaming. The mobile terminal includes a modulator (MOD) 14A, a transmitter 14, a receiver 16, a demodulator (DEMOD) 16A, and a controller 18 that provides signals to and receives signals from the transmitter 14 and receiver 16, respectively. These signals include signalling information in accordance with the air interface standard of the applicable cellular system, and also user speech and/or user generated data. It is understood that the controller 18 also includes the circuitry required for implementing the audio and logic functions of the mobile terminal. By example, the controller 18 may be comprised of a digital signal processor device, a microprocessor device, and various analog to digital converters, digital to analog converters, and other support circuits. The control and signal processing functions of the mobile terminal are allocated between these devices according to their respective capabilities. A user interface includes a conventional earphone or speaker 17, a conventional microphone 19, a display 20, and a user input device, typically a keypad 22, all of which are coupled to the controller 18. The keypad 22 includes the conventional numeric (0-9) and related keys (#,*) 22a, and other keys 22b used for operating the mobile terminal 10. These other keys 22b may include, by example, a SEND key, various menu scrolling and soft keys, and a PWR key. The mobile terminal 10 also includes a battery 26 contained in a battery pack 26A for powering the various circuits that are required to operate the mobile terminal. The mobile terminal 10 also includes various memories, shown collectively as the memory 24, wherein are stored a plurality of constants and variables that are used by the controller 18 during the operation of the mobile terminal. For example, the memory 24 stores the values of various cellular system parameters and the number assignment module (NAM). An operating program for controlling the operation of controller 18 is also stored in the memory 24 (typically in a ROM device). The memory 24 may also store data, including user messages, that is received from the BMI 32 prior to the display of the messages to the user. For the purposes of this invention the memory 24 is assumed to store a system or network ordered priority list (PL) 24A, and may store also a network history list (HL) 24B, as described below. Furthermore, in some embodiments of this invention a portion of the memory may be employed to maintain a real time clock (RTC) 23, such as by incrementing memory locations periodically. Alternatively, a well-known type of RTC device can be included within the terminal 10, which can be read as desired by the controller 18. For the purposes of this invention the transmitter 14, receiver 16, modulator 14A and demodulator 16A may be dual-mode capable, and may operate with the frequencies, modulation types, access types, etc. of the primary and secondary systems. Alternatively, dual mode operation can be achieved by duplicating these components for each system of interest, and by also providing certain components that are capable of operating in both systems. It should be understood that the mobile terminal 10 can be a vehicle mounted or a handheld device. It should further be appreciated that the mobile terminal 10 can be capable of operating with one or more air interface standards, modulation types, and access types. By example, the mobile terminal may be capable of operating with any of a number of other standards such as GSM and IS-95 (CDMA). The teaching of this invention is particularly useful in those types of systems that do not provide inter-network roaming. It should thus be clear that the teaching of this invention is not to be construed to be limited to any one particular type of mobile terminal or air interface standard, and is furthermore not limited only to dual mode operation, as tri-mode and higher terminals can also benefit from the use of this invention. The operating program in the memory 24 includes routines to present messages and message-related functions to the user on the display 20, typically as various menu items. The memory 24 also includes routines for implementing the method described below in relation to FIGS. 3-5. In general, the automatic mode selection operation requires the multimode terminal 10 to be capable of scanning the networks, scanning here meaning scanning of a network while being connected to another network. If the terminal 10 is using its preferred or primary network (the first one in the ordered list 24A), then it stays connected to the primary network until the network is no longer available (connection lost, coverage too weak etc.), and/or until some other criterion is met or other criteria are met, as will be described below. The terminal 10 then begins scanning for the second network (i.e., the secondary network) in the ordered priority list 24A. If the secondary network is found a connection is then made to the secondary network, and the current connection to the highest priority network is disconnected. If the connection to the secondary network fails, or if no secondary network is found, the terminal 10 attempts to locate a third network in the ordered list 24A (if present in the ordered list). This process continues until the end of the list is reached. If no network is available, the terminal 10 enters a power save state for a certain period of time, after which it again begins scanning for networks, starting with the first network (i.e., the primary network) in the ordered list 24A. Assuming now that the terminal 10 makes a successful connection to the secondary network, since this is not the preferred mode of operation, the first network in the ordered list is periodically scanned. If it is found and is available, the current network connection is cancelled (disconnected) and an attempt to connect to the preferred network is made so long as an active call is not in progress. If an active call is in progress, the connection to the other network can be made automatically after the termination of the call. If the secondary network is not found, and a successful connection to a tertiary network is made, the periodic scanning is first performed for the primary network, and if not found then the secondary network is scanned. If the secondary network is not found or is not available, the terminal 10 remains connected to the tertiary network. If the primary network is not found or is not available, but the secondary network is found, a connection to the secondary network is made and the current tertiary network is disconnected. This invention thus pertains to the network selection procedure, which is triggered by (a) a loss of service in the current network or (b) if the scanning of a preferred network produces an output that indicates that the preferred network is available. The network selection criteria can also be based on, by example, the use of cell broadcast messages, wherein the network sends information concerning call rates. In this case the terminal 10 may receive broadcasts from different networks and then selects the lowest cost network that is currently available. In this embodiment the network sends call rates and the time of day when the rates are valid. With the use of a real time clock within the terminal 10, the terminal can automatically switch networks so as to always avail itself of the lowest rates for incoming and/or outgoing calls. Further with regard to cell broadcast messages, a given system operator may have two different networks in a certain area. Because of congestion in one network the system operator may send a message to instruct all or some dual mode terminals in that area to use the less congested network. The operator may include a timer in the message, the timer being used to keep the terminal in the less congested network until the timer elapses. Only at that time does the terminal 10 begin scanning for the other network. In this manner the operator may more evenly distribute the usage of the networks in a given area. The network selection criteria can also be based on, by example, a received signal strength indicator RSSI (or C1 in GSM systems). Normally C1 (RSSI) is used to select a suitable cell within a network. However, it can also be used to select a more suitable network to which the terminal is allowed to connect. This reduces the current consumption in the terminal, since a lower transmitter power would be used (it being assumed that the network having the highest RSSI would require less terminal transmission power). The network selection criteria can also be based on, by example, the above-mentioned real time clock 23. Normally system operators have different call rates at different times of the day. In order to facilitate the use of time information, the user can employ the user interface to program the terminal to change networks at particular times. It is also within the scope of the teaching of this invention to base the network selection criteria on a prediction of when the terminal 10 is about to lose the connection. By example, if it is observed that the RSSI is gradually decreasing over time, and/or that the bit error rate (BER) or word error rate (WER) is gradually increasing, a prediction may be made that the terminal 10 is losing the connection with the current primary network. In the case where RSSI and BER and/or WER are used the criteria can be considered to be related (i.e., signal strength and signal quality). Also in this case the terminal 10 may "prestart" the module for the other secondary network, command the module to perform network scanning (without transmitting), make a proper detach from the primary network, and finally make a new connection to the secondary network. In this case the mode switching can be achieved in a rapid fashion. In other cases the mode switching criteria may be unrelated, such as RSSI and time of day, or BER and network rate structure. Reference is now made to FIG. 3 for illustrating an embodiment of a method of this invention. The terminal 10 enters Block 1.0 at initial power on or from Blocks 2.1, 2.2, 2.3, 2.4, or 3.0, as described below. Block 1.0 is a Search for Primary System or Network Block wherein the terminal 10 scans its receiver 16 in order to locate a transmission from the first network listed in the ordered list 24A. Assuming now that the search for the primary network is successful, that is, that the primary network is located and that the terminal 10 has successfully registered in the primary network for all available services for the terminal's subscription, the terminal enters Block 1.1 "Service in Primary Network". The terminal 10 stays in Block 1.1 until service is lost (or is predicted to be lost) or until, for some reason, the terminal 10 is switched from a full service to a limited service state. A number of other criteria may also be employed, as described previously and as will be described in further detail below. In any event, the terminal 10 places the primary mode module (e.g., the digital TDMA module) into a low power state (see, for example, FIGS. 4 and 5) and enters Block 2.0 (Search For Secondary Network). Before proceeding further with this description, reference is again made to Block 1.0. For the case where the terminal 10 is unable to successfully register in a "full service" mode, the terminal 10 may be registered instead for limited service. For example, GSM defines a limited service mode wherein a terminal can make emergency calls, but cannot otherwise make or receive calls. This condition may be only temporary due to, for example, system loading considerations or component malfunctions. As such, after some period of time in the limited service mode of Block 1.2 the terminal 10 may be granted full service. At this time the terminal 10 enters Block 1.1, and remains there until service is lost, limited service is reinstated, or some other criteria are fulfilled. While in the limited service mode (Block 1.2) the terminal 10 periodically puts the primary mode module into the low power state and enters Block 2.0 to search for a secondary network. That is, operation in the secondary network may be preferred to only limited service in the primary network. Returning again to Block 1.0 if the search for the primary network is unsuccessful, either because the network could not be located or because the terminal could not register for either full service or limited service, the primary mode module is put into a low power state and Block 2.0 is entered to search for the secondary network. It is noted that putting the primary mode module into a low power state ("to sleep") typically entails powering down or off the circuits required to receive and demodulate the digital transmission, while powering up or activating the circuitry required to receive and demodulate the analog (e.g., AMPS) network. In other embodiments this could entail powering down the TDMA-related circuitry while activating CDMA-circuitry, assuming that a TDMA system is the primary system and a CDMA system is the secondary system. Referring now to Block 2.0, and assuming that the terminal 10 has successfully located and registered into the secondary network, the method enters Block 2.1 (Service In Secondary Network). This block differs from the previously described Block 1.1 in that there are at least two ways to exit Block 2.1. A first method is if service is lost in the secondary network, or if the secondary network is placed in the limited service mode. In this case, the secondary mode module is placed in the low power state and control passes back to Block 1.0 to search for the primary network. A second exit results from the expiration of a timer which indicates that it is time to automatically scan for the primary network. A second condition, in addition to the timer expiring, is that the terminal 10 be in an active idle state wherein the terminal 10 is not actively involved in a call. In this case the terminal operation periodically enters Block 2.3 to scan for the primary network. If the primary network is not found control passes back to Block 2.1 to remain in the secondary network. However, if a "promising" primary network is located, the secondary mode module is placed in a low power mode and control returns to Block 1.0. A "promising" primary network, for the purposes of this invention, is a network that is not forbidden for the mobile terminal 10 to access. It should be noted that the terminal is capable of receiving calls from the secondary system while scanning for the primary in Block 2.1. If while scanning for the primary network some activity occurs in the secondary network, such as the receipt of a call, the scanning is terminated and the results ignored. Control then passes back to Block 2.1. In this regard the terminal 10 may generate the history list (HL) 24B that is stored in the memory 24. The history list 24B can be used to indicate those networks that are found to be forbidden or otherwise not accessible by the terminal 10. The history list 24B can thus be used to prevent the unnecessary scanning for and attempted registration into forbidden networks. The history list can be periodically updated and/or erased, as a given network may be only temporarily forbidden to the terminal 10. Returning now to Block 2.0, if the terminal 10 is instead granted limited service in the secondary network, control passes to Block 2.2. The terminal remains in Block 2.2 until granted full service, at which time control passes to Block 2.1, or until a periodic rescanning of the primary network is performed at Block 2.4. If the primary network is not found, control passes back to the limited service mode of Block 2.2. If a promising primary network is found, the secondary network is put to sleep, and control passes back to Block 1.0. The terminal 10 may reside in the limited service secondary network (Block 2.2) if this is the only service available. Returning again to Block 2.0, if the secondary network is not found control passes instead to Block 3.0 where the terminal 10 enters a low power state for some predetermined period of time. In a preferred embodiment of this invention the period of time is variable, such as 5 seconds, 10 seconds, 20 seconds, . . . , 2 minutes, etc. That is, the power save period gradually increases with time (to some maximum value) if neither the primary or secondary networks are found. At the expiration of the power save time period control passes back to Block 1.0 in order to once more search for the primary network. Block 2.0 can be entered from Block 1.2 and also from Block 1.3 (limited primary service and power -- on or time to scan secondary during active idle). At Block 1.3, and if the secondary network is not found, control passes back to Block 1.2 to provide the terminal 10 with at least limited service in the primary network. If a promising secondary network is found in Block 1.3, control passes to Block 2.0. Reference is now made to FIGS. 4 and 5. These figures illustrate the interactions between the three main control systems for a dual mode terminal. A first control system is for the primary system (e.g. a DCS1900 digital system), a second control system is for the secondary system (e.g. an IS-41 analog system), and a third control system is referred to as a dual mode control which mediates and controls the switching between the primary and secondary systems. FIG. 4 shows that when the terminal 10 is connected to the secondary network, it scans the primary network periodically. The connection to the primary network is made when the scanning is successful and the secondary network is not active (call in progress, etc.). It should be noted that, for simplicity, the scenario presented in FIG. 4 does not include messages indicating the systems entering the limited service state. The limited service states and the conditions and actions associated with these states can be found in FIG. 3, as discussed above. FIG. 5 illustrates the case where the secondary system is in service, and the periodic scanning for the primary system. If during the scanning (between and including "Timer Expires" and "primary scan ok/fail") a call is received in the secondary system, not shown in this flow chart, the scanning may be stopped with a scan stop message. The invention has been primarily described in the context of mode switching that occurs upon a loss of signal that results in the existing connection being lost or in danger of being lost. However, it should be realized that one or more other criteria can be used in making the mode switching decision. By example, assume that the terminal 10 is operating in the secondary system (Block 2.1), and the user desires to send or receive a facsimile or to send or receive a short message service (SMS) transmission. In this case the existing secondary network, although possibly having adequate signal strength, can be considered to have a limited functionality. That is, the secondary network does not support the user's current communications needs. In this case, the method exits Block 2.1, as though the service were lost, and reenters Block 1.0 to search for the primary network. In this case, it is further assumed that the primary network does support the user's current communication needs. Other suitable criteria can be based on differences in calling rates between the primary and secondary systems. By example, during a certain time of day it may be less expensive to operate in the secondary network than in the primary network. The terminal 10 is assumed to maintain the real time clock 23 or to otherwise have access to a current time of day (the BMI 32 may periodically broadcast the time of day). In any event, at a predetermined time that is either programmed by the user or received from the network, the terminal 10 can exist Block 1.1 as though the service were lost and enter Block 2.0 to search for the secondary network. The terminal 10 can then reside in Block 2.1 until the expiration of a timer or until the real time clock 23 indicates that the rates have dropped in the primary system. At this time the mobile terminal 10 exits Block 2.1 as though the service were lost and reenters Block 1.0 to reestablish service in the primary network. As such, it should be realized that the transition from primary to secondary and secondary to primary systems can be based on one or more related or unrelated criteria (e.g. signal strength and/or time of day). It should further be realized that it is within the scope of this invention to identify a plurality of primary networks based on functionality. By example, one primary network may be preferred for its long distance calling rates, while another primary network may be preferred for its data transmission capability. As such, Blocks 1.0 and 1.1 can be modified so as to recursively search for a first preferred primary network (for example when the user intends to make a long distance telephone call). If service in the preferred primary network is not available, then Block 1.0 can be reentered so as to search for a second primary network (e.g. one that provides long distance service but at a less-favorable rate, or one that also provides data service but at a lower maximum transmission speed). Although described in the context of preferred embodiments, it should be realized that a number of modifications to these teachings may occur to one skilled in the art. By example, the logic flow diagram of FIG. 3 can be modified to add or delete steps, while still performing the same functions. In a similar manner the message passing interaction depicted in FIGS. 4 and 5 can be modified to add or delete messages. Also, and as was previously mentioned, these embodiments can be modified so as to accommodate tertiary and higher networks in the priority list 23A. It is further within the scope of this invention to provide a capability in the terminal's user interface to indicate to the user that the network reselection has been or is being performed. This feature may be further enabled or disabled by the user, through the use of a suitable programmed menu function. Also, this invention provides a capability to provide a "manual" system handoff procedure. For example, assume that a user is involved in a call in a first network, and it becomes apparent that the connection to the current network will soon be or has been lost. In this case, the terminal 10 may automatically terminate the current call, if not already lost, rescan and locate a second suitable network, and then automatically call the same number (which is assumed to still be stored in the memory 24) and reestablish the call using the second network. Thus, while the invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the scope and spirit of the invention.

A wireless user terminal (10), such as a multimode cellular telephone, includes at least three master control systems, specifically a primary system controller, a secondary system controller, and a multimode controller. The multimode controller is capable of bidirectionally exchanging control messages and status messages with the primary and secondary system controllers for automatically switching the state of the terminal bidirectionally between the primary and secondary systems.