bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Images and Community Images of the Elementary School Principal
Authors: Foskett John M. , Wolcott Harry F.
Published: March 2007

The following reported research scrutinizes the role of the elemen tary principal in an unusual way. Based on responses to a role norm inventory the authors analyze the difference between the perceptions various groups have of the role of the elementary principal. The data also include the perceptions of the principals as to the views of each of the other groups. In addition to summarizing the basic findings the authors discuss some of the possible implications of the data. This article is a revision of a paper presented at the annual meeting of the NEA Department of the Elementary School Principals, March 22, 1966, Portland, Oregon.
Social Symptoms in the Community
Authors: Hannay D.R.
Published: March 2007

The prevalence of social symptoms amongst a sample of adults, registered at a health centre, is described from home interviews. The frequency of social symptoms was correlated with a number of personal and environmental variables, and multivariate analysis used to indicate the relative importance of factors which might be causal.
Behavioural Symptoms in the Community
Authors: Hannay D.R.
Published: March 2007

The prevalence of behavioural symptoms amongst a sample of 380 children of 15 years and under, is described. 24% of children had behavioural symptoms, as defined by the subjective responses of parents to a structured questionnaire at home interviews. The frequency of behavioural symptoms was correlated with a number of personal and environmental variables, of which long stays in hospital, not being looked after by a parent, and a high neuroticism score for the parent or responsible adult, were the main predictors for the presence of behavioural symptoms in children.
Extended Foams
Authors: Einhorn I.N.
Published: March 2007

The commercial development and growth rate of rigid urethane foams has not met the forecasts presented by the chemical industry. Difficulty in meeting building code require ments and specifications established by regu latoiy groups coupled with relatively poor comparative economics of applied insulation has retarded the growth and acceptance of many foam products. A review of extended foams systems based on the incorporation of low cost commodity chemicals into foam sys tems will be presented. These modified sys tems, while significantly lower in cost, have gained only limited acceptance due to the loss of dimensional stability, lower heat dis tortion properties, and increased permeability.
Some Application Developments of Rigid Plastic Foams in Japan
Authors: Nagai Satoshi
Published: March 2007

Rigid plastic foams in Japan date from the early 1950's. Polystyrene and rigid ure thane foams are the most promising mate rials, their principal applications being in sulation of cold storage space, buildings and ships.

The following insulation applications in Japan are described and illustrated (in most cases the insulating material was extruded foamed polystyrene board): fish storage houses, controlled-temperature rooms on ships, "sake" breweries, "miso" plants, pipe coverings (urethane foam), acrylonitrile ab sorption towers and ammonia tanks, apart ment houses, cooling tower grids and bath tubs. Additional applications pictured in clude "tatami" and "fusuma," protective packaging and polystyrene paper (from sheet or film).
The Production Chemist and Flexible Urethane Foam Technology
Authors: Walmsley G.D.
Published: March 2007

The production chemist contributes to ure thane foam technology through development of control tests plant and formulation changes. Urethane foams are made by three types of machines but common principles appear to ap ply. Dissolved air is essential to foam forma tion, and cell size is regulated by "cavitation" (extraction of dissolved gases). Greater cavi tation gives faster nucleation and finer cells. Cavitation, controlled by outlet orifice diame ter in the high pressure/low shear mixing head and by rotor speed in the low pressure/ high shear head, does not occur in the low pressure/intermediate shear head so air must be added.

Additional factors influencing cell size are the presence of fluorocarbons or finely di vided solids. Constant surfactant concentra tion is important for foam stability.
Some Effects of Molecular Structure on the Production of Flexible Urethane Foams
Authors: Lowe A.J. , Chandley E.F. , Leigh H.W. , Molinario L.
Published: March 2007

Modifications to the chemical nature of polyols, catalysts, and surfactants which give easier foaming conditions are presented.

Two new series of activated polyols are described. Their surface-active properties, efficiency as co-solvents for urethane inter mediates, and gelation rates are discussed and means of separating the control of these phenomena outlined. Results are given on the use of a number of new catalyst and surfac tant systems, some of which have shown out standing promise, particularly in the areas where catalyst balance has previously been difficult. Formulations and physical properties of the foams produced are presented and discussed.
Portable Helix Mixer for Urethane Foam
Authors: Knox R.E.
Published: March 2007

A urethane foam mixer newly developed by Du Pont is light and compact, has no moving parts, yet blends urethane foam feed streams thoroughly as the mixture flows through a spiral chamber. The "helix" mixer has been used to process rigid and flexible urethane foams by both conventional and froth meth ods. It is easily adapted to existing foam me tering systems for factory or field application. It produces foams with cell structure and physical properties equivalent to those ob tained with heavy duty, agitator-type mixers. The helix mixer has been adapted and used for the trigger controlled on-off dis charge of mixed foam materials. The varia bles which affect helix mixer output and mix ing efficiency have been investigated, which will permit mixer scale up to outputs of sev eral hundred pounds per minute.
Thermal Decomposition of Rigid Urethane Foams
Authors: Backus J.K. , Darr W.C. , Gemeinhardt P.G. , Saunders J.H.
Published: March 2007

Investigation of the thermal degradation of rigid urethane foams by means of TGA, DTA, infrared, and other techniques indicated that rigid foams prepared from a polyoxypropyl ene ether and a polymeric diphenylmethane type polyisocyanate began to decompose at ap proximately 210°C. Loss of weight occurred in two stages of approximately 50% each, oc curring at approximately 250-350°C and 400- 600°C. A similar pattern of decomposition was found for urethane foams based on a chlorinated polyester and the same polyiso cyanate. Addition of a reactive organophos phorous flame retardant to the polyoxypropyl ene ether foam lowered the temperature of initial decomposition to 150-170°C. The weight fraction of char formed at tempera tures above 400°C was increased, however.
The European Market for Urethanes
Authors: Bizalion M.
Published: March 2007

A brief review is presented of factors in the European rigid and flexible urethane foam market. Some differences in requirements and potential in various countries are discussed.
Some Effects Of Gas Transfer On Rigid Foam Performance
Authors: Harding R.H.
Published: March 2007

Foam properties subject to the action of transfer phenomena include thermal conduc tivity (variable gas-phase composition) and dimensional stability (variable total gas pres sure). The commercial importance of such qualities suggests that a detailed analysis of basic mechanisms should contribute to a more rapid advance of rigid foam application tech nologies.

Simultaneous consideration of transfer rate theory and material balances produced a model which characterizes the partial pres sures of gases contained within unicellular foams. A supplemental method for systemati cally evaluating resultant unsteady-state nu merical matrices was also developed. A few selected effects of polymers, blowing agents, specimen thickness and surface condition, specimen age, and environmental factors were then discussed and related generally to boards cut from air-filled ( polystyrene) and fluorocarbon-blown ( urethane) foams.
One-Shot Semi-Rigid Foam System- Process and Properties
Authors: Huester P.K. , Huntington D.P.
Published: March 2007

The word "one-shot" in flexible urethane foam technology was the harbinger of lower cost products with reproducible properties. The development of L-520 organosilicone stabilizers along with tin catalysts made one- shot flexible foam a reality. The basic prin ciples learned in flexible foam have been ex tended to a one-shot semi-rigid foam system described in this article. In particular, a sys tem. to provide stabilization during the foam rise and cell opening at the end of the rise was required. To the usual benefits of a one- shot system we added versatility in formu lating. Foam properties are controlled by a proper choice of polyols, water and the tin and amine catalysts. This control and versa tility is necessary to meet the property de mands of free-blown and molded foam prod ucts. This new system was developed on the bench and proven on production machines.
Some Effects of Crosslinking Upon the Foaming Behavior of Heat Plastified Polystyrene
Authors: Rubens L.C.
Published: March 2007

Crosslinking of polystyrene containing blowing agents has a large effect upon foam ing behavior at elevated temperatures. The foam volume and resistance to thermal col lapse are both greatly increased by lightly crosslinking the polymer. If the crosslink density is too high, however, expansion is re stricted and foam stability decreases. The foaming behavior of a series of styrene-di vinyl benzene copolymers impregnated with carbon dioxide has been studied in detail at temperatures from 100 to 200°C. An at tempt has been made to correlate the in ternal pressures at maximum expansion with the theoretical elastic retractive forces of the copol ymer networks. A mechanism for ther mocollapse of polystyrene foams is proposed.
Prisonization or Resocialization?
Authors: Thomas Charles W.
Published: March 2007

This report focuses on data obtained from 276 adult male felons who were inmates in a maximum-security penitentiary in 1971. The general intent of the larger study of which this essay is a part was to test the viability of two available explanations of the impact of confinement. One of these models, often referred to as the "deprivation model," provides a restrictive perspective by virtue of its unusually heavy emphasis on intra-institutional processes and influences. A more recent approach, the "importa tion model," accepts the importance of such intra-institutional variables, but also points to the importance of variables that originate outside the context of the prison and, in many cases, cannot be directly manipulated by correctional officials. The specific variables reported in this pa per include measures of social class of origin, social class of attainment, preprison involvement in criminality, extent of contact with the larger society during confinement, and the inmates' perceptions of their post-prison life-chances. These independent variables were correlated with a measure of prisonization. The findings provide evidence in sup port of the more inclusive conceptualization provided by the im portation model. The obvious implication is that overemphasis on intra-institutional factors will only prove to be misleading.
Computing Mean Cost Ratings (MCR)
Authors: Inciardi James A. , Babst Dean V. , Koval Mary
Published: March 2007

The Mean Cost Rating (MCR) measures the differentiation ability of those variables or groups of variables used in construct ing parole prediction or base expectancy tables. The literature of the past two decades suggests that it represents perhaps the most satisfactoiy statistical index of predictive selectivity. Its use has been limited, however, by its complex method of computa tion. The MCR is explained and a simplified procedure for com puting it is offered. In addition, the MCR is compared with Chi square, the J-value, and the Index of Predictive Selectivity, which have also been used to determine the selective ability of factors in the construction of prediction tables.
Birth Order as a Variable of Probation Performance
Authors: Mullin James B.
Published: March 2007

Research studies have indicated that first-born (including only children) and later-born individuals present different personality and behavior characteristics. First-borns tend to be more depend ent, seeking out others when under stress, while later-born indi viduals appear to be more independent and attempt to resolve conflict through their own means.

An application of this theory to the broad field of correction and specifically to probation has been largely overlooked. Proba tion, in its simplest terms, involves the guidance of an individual who has encountered conflict with the law and who has been placed by the court under the supervision of another person. Applying birth order theory to this process, we would expect that first-born and later-born probationers would exhibit differ ential responses to this treatment.

This paper sought to determine whether this result would be realized by studying 246 cases in eight county probation depart ments in New York State in which probation was terminated either by discharge or by violation. The study reports a signifi cant difference, finding that first-borns demonstrated a higher tendency to complete their probation, while later-borns were overrepresented among those who violated their probation.
Intelligence and Affect Awareness in Classifying Delinquents
Authors: Zaidel Susan F.
Published: March 2007

The study examined certain aspects of the validity of the Inter personal Maturity Level Classification, which has been used in treating delinquents in the California Youth Authority. Specifi cally, the roles of intelligence and affect awareness in the classifi cation system were studied. Groups of institutionalized deliquent girls at different levels of "interpersonal maturity" were compared on several measures of intelligencre and degree of awareness of feelings in others. The results indicated that intelligence, verbal fluency, and race were the most important components of Inter personal Maturity Level considered. Higher levels of maturity were also accompanied by greater attention to affect cues and better judgment of nonverbal expressions of affect. The findings concerning affect awareness, while consistent with the theory behind the classification system, point to differential salience of affect as the key variable underlying differences in awareness of feelings in others. The data on intelligence point to the need for further research to clarify the actual components of the Inter personal Maturity Level Classification.
Absconding from Approved Schools as Learned Behavior
Authors: Green J.R. , Martin D.N.
Published: March 2007

The frequency distribution of absconding from approved schools is not a chance distribution. However, it has not proved possible to identify absconders on the basis of their personal char acteristics. This paper investigates whether the greater liability of some boys to abscond could reflect learning. As anticipated, the frequency distribution of abscondings appeared to be a nega tive binomial distribution. However, a learning model is not the only kind which could lead to this distribution and we report methods for determining the process which produced it in this case. Contrary to expectation, there was evidence of unequal initial absconding tendency for our subjects, but no evidence of learning. The statistical methodology may have important appli cations in criminology.
Evaluation Studies on Group Treatment of Juvenile and Adult Offenders in Correctional Institutions
Authors: Slaikeu Karl A.
Published: March 2007

This paper reviews twenty-three studies (based on a literature search covering 1945-70) evaluating group treatment of juvenile and adult offenders in correctional institutions. The studies are discussed critically under such headings as definition of treat ment, goals and theoretical presuppositions, and experimental design. The major conclusion drawn from the review is that, although the evaluation studies report a variety of positive re sults, still, as a whole the investigations fall short of meeting the criteria of scientific research, especially regarding replication; this makes it im possible to conclude that group treatment in correc tional institutions is an effective rehabilitation mode. Several issues deserving the attention of researchers are suggested, one of which is the question of the compatibility of institutional and post-institutional adjustment as criteria of success in group treat ment.
Racial Identity, Length of Incarceration, and Parole Decision Making
Authors: Elion Victor H. , Megargee Edwin I.
Published: March 2007

Previous research has disclosed significant differences in the severity of sentences imposed on black and white offenders. This study investigated racial differences in black-white sentence patterns at the final stage of the criminal justice process, focusing on the actual amount of time served and the frequen cy of parole in a sample of 958 youthful offenders from a cohort of 1,345 consecutive admissions to a federal correctional institution.

No racial differences were found in the actual amount of time served, but a significantly higher percentage of whites than blacks were granted parole. Blacks who were granted parole served a smaller portion of their sentences than did whites who were granted parole, but nonparoled blacks served a greater portion than did nonparoled whites. Discriminant function analysis did not show race to be significantly associated with decision to grant parole; instead, the primary factor was the entry sentence, with offenders sentenced to relatively short terms (less than eighteen months) being paroled less fre quently than those with longer terms. Since blacks were more likely to have the shorter sentences, the racial difference in percentage granted parole was partly attributable to the severity of the sentence imposed originally.

Examination of thirteen offender variables reflecting personal and social history, legal factors, and institutional adjustment measures revealed signifi cant differences between paroled and nonparoled inmates but not between racial groups. Further discriminant analysis of factors associated with parole within black and white subsamples indicated that, of the thirteen variables examined, entry sentence, violence of offense, and adult maladjustment and deviance were significantly associated with likelihood of parole for both racial groups. Institutional adjustment also appeared to play an important role in decisions regarding blacks, while variables relating to personal and social ad justment before incarceration seemed to be more important among whites.

It is speculated that the observable overrepresentation of blacks in penal and other correctional institutions is attributable to decisions made earlier in the criminal justice process, rather than to biased parole-granting procedures, at least in this federal institution. Further research on possible interaction of social deficits and criminal justice decision making instead of race and sen tence severity is suggested.
The Postrelease Trauma Thesis
Authors: Minor W.William
Published: March 2007

The postrelease trauma thesis is that during the time immediately following release from prison the offender faces particular stress, which often cul minates in renewed criminal activity. Although this thesis enjoys almost uni versal acceptance by criminologists, it can be questioned on several grounds. First, from an importation perspective, entry into or exit from the prison community may not represent a major break in the felon's life; his role may be seen as remaining continuous before, during, and after imprisonment. Sec ond, the failure to reduce recidivism through programs designed to ease the transition from prison to community suggests that they may, by nature, be superfluous. Third, the most common way of reporting parole violation data overstates the risk during the early parole period relative to later periods. Finally, the social organization of parole work makes apprehension of vio lators more likely during early months than it is later on, regardless of the parolee's behavior.

These issues suggest the need to exercise caution in the interpretation of parole statistics. More generally, they suggest that the postrelease trauma thesis itself should not be accepted without extensive and rigorous empirical examination.
Sociodrama and Teacher Education
Authors: Jacobs Arthur J.
Published: March 2007

The accompanying article applies to teacher education some of the findings of Lewin and others in the group-develop ment field. Mr. Jacobs, staff member of the Michigan State College Department of Effective Living, recommends the use of role-playing in the development of abilities especially important to the teacher.
Summary of an Investigation of College-Teacher Supply and Demand
Authors: Mosier Earl E.
Published: March 2007

This article presents an abstract of the findings of the first nationwide study of college-teacher supply and demand in the United States. Mr. Mosier, Assistant State Superintendent of Public Instruction in Michigan, directed the study, which was jointly sponsored by the North Central Association of Colleges and Secondary Schools and the National Commission on Teacher Education and Professional Stand ards. It was a companion study to the 1950 National Teacher Supply and De mand Study directed by Ray C. Maul, now in its fourth year. Copies of the complete report of the Mosier study may be secured by writing the National Commission on Teacher Education and Professional Stand ards, 1201 Sixteenth Street, Northwest, Washington 6, D. C.
A Proposed Program for the Preparation of Men Physical-Education Teachers in Wisconsin1
Authors: Beck Eugene E.
Published: March 2007

The hiatus between preparation and practice has long been recognized as a major weakness running throughout teacher education. In this article Mr. Beck documents the gap between professional education and actual teaching in the field of physical education. The data and rec ommendations are abstracted from the author's dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physical Education at The Ohio State University, 1949.
The Concept of Competence: Its Use Edmund C. Short and Misuse in Education
Authors: Short Edmond c.
Published: March 2007

Few terms have been as misused and as overused as has "competence." The language of educators is filled with refer ences to the need to enhance teacher competence or to assure teacher compe tency. Short attempts to clarify the meaning of the term by describing four common conceptions of competence. The first conception refers to specific behaviors or performances and, accord ing to the author, should be limited to precise and measurable things. The sec ond conception relates to command of knowledge and skills and like the first conception has a relatively narrow focus. Conception three should be used in con nection with value issues such as identi fying the degree of sufficiency of compe tence. The fourth conception, and the preferred one, argues Short, entails defining competence holisticly.
Consortium for the Improvement of THEME Teacher Evaluation Homer Coker
Authors: Coker Homer
Published: March 2007

Coker describes the conceptual frame work of and purposes for two organiza tional structures: The Consortium for the Improvement of Teacher Evaluation and The Research and Development Center for Teacher Evaluation. Both organiza tions are focused on improving the quali ty and quantity of research conducted on assessing teacher behaviors in the class room that impact on student academic growth. The author outlines three major thrusts for research to be undertaken by the Consortium, and he describes how the expertise of the Research and Devel opment Center will support Consortium activities.
Colleague Training and Peer Review THEME
Authors: Copeland Willis D. , Jamgochian Richard
Published: March 2007

The isolation of teachers is a well- documented phenomenon. The authors argue that an approach to counter this isolation is training teachers in colleagiali ty during the teacher preparation pro gram. Such training requires a program that accommodates and encourages dialogue among prospective teachers. The benefits of colleagial observation and interaction are described by Cope land and Jamgochian, and one example of how teacher educators are striving to foster colleagial relationships among students is presented.
An Empirical Analysis of the Power Robert F. Schuck of Set Induction and Systematic Questioning as Instructional Strategies
Authors: Schick Robert F.
Published: March 2007

For the past decade, teacher educators have addressed them selves to the problems inherent in the definition of desired teaching skills and in the design and implementation of teacher edu cation curricula that would facilitate the acquisition of teaching skills. This investigation addresses the comparative impact of two teaching skills upon student achievement and retention. The power of set induction and systematic questioning as instruc tional tools are reconfirmed by the researcher. Professional educators seeking to build an empirically based curriculum now have additional data that support the inclusion of these skills in preparation programs.
States of Consciousness: A New POTPOURRI Intellectual Direction, a New Teacher Education Direction Thomas B. Roberts
Authors: Roberts Thomas B.
Published: March 2007

Researchers in diverse fields are con structing a new intellectual direction and a new image of human nature. This article sketches some of the resulting implications for teacher education, especially the acceptance of "conscious ness" as a legitimate topic of scholarly and scientific inquiry. New principles of learning based on the research on states of consciousness offer opportunities for teacher educators to restructure curricu lum, to modify content, and to revise instructional methods.
British Imports of Manufactured Goods
Authors: Ray G. F.
Published: March 2007

Imports of manufactured goods, both of finished manufactures and of textiles, have been rising rapidly in Britain—over 50 per cent in the last five years ; they are now much bigger, in relation to national output, than they were before the war.
Some Practical Aspects of Human Capital Investment: Training Standards in Five Occupations in Britain and Germany
Authors: Prais S.J. , Wagner Karin
Published: March 2007

Government policy to increase substantially the amount of vocational training and education available to school-leavers in this country raises the issue of how much and what kind of training is provided elsewhere. This article describes the training given in Britain and Germany in five of the more popular occupations: mechanical fitter, electrician, construction worker, office worker and retailing. Comparisons are made of the scope of the syllabus, and the standard reached at final tests. One of the important differences is the greater emphasis on practical (in contrast to theoretical or written) tests in all these occupations in Germany, which are carried out under examination conditions. It also appears that a greater proportion have reached basic and tested standards in mathematics at school; this provides a firmer basis for subsequent vocational instruction. The gap between the two countries in training standards and numbers of trainees is particularly marked for the two occupations catering mainly for female entrants-office workers and retailing. Shortcomings in Britain's industrial performance have often centred as much on delivery delays and poor ‘progress chasing’—which require responsible and competent office personnel—as on technical faults. These comparisons indicate the scope for very substantial advances in both the quantity and the quality of training in this country.
The Diffusion of Mature Technologies
Authors: Ray George F.
Published: March 2007

The National Institute studied the diffusion of new technologies more than ten years ago: our first report on this subject was published in 1969 followed by a major book. The purpose of the earlier studies was to analyse the introduction and diffusion of major postwar process innovations in several industrial countries, the factors which facilitate or hinder the adoption of the then new techniques, the pattern of diffusion and the influences to which it is subject. The analysis was based on the situation at the end of the 1960s. Since then the processes, which were then relatively new, have matured. In 1982 we started a new project in order to assess and analyse their diffusion in a later phase.
Public Sector Borrowing and the Public Sector Balance Sheet
Authors: Britton Andrew
Published: March 2007

In his Budget Statement this year the Chancellor restated his medium-term financial strategy (MTFS) and in particular his objectives for the public sector borrowing requirement (PSBR). He said, ‘Since its inception in 1980 the MTFS has indicated a steadily declining path for the PSBR expressed as a percentage of GDP. We have now reached what I judge to be its appropriate destination: a PSBR of 1 per cent of GDP. My aim will be to keep it there over the years ahead. This note considers the implications of that scale of borrowing for the balance sheet position of the public sector. We are able to do this with more confidence thanks to recent publication by the CSO of new figures for the balance sheet positions of all sectors of the economy up to the end of 1985. Prior to that publication, the latest figures available for the overall balance sheet position of the public sector had referred to 1975. The new data modify the picture of recent trends, without changing their character fundamentally.
Qualified Manpower in Engineering
Authors: Prals S.J.
Published: March 2007

This article examines the numbers of skilled persons in engineering and allied occupations who qualify each year throughout the skill range—from an engineering doctorate to craftsmen and technicians—and compares Britain with other advanced industrial countries. The main quantitative difference between Britain and other countries lies in the numbers qualifying at the level of qualified craftsman; attention is also drawn to an important qualitative difference in practical content and length of university-degree courses in engineering.
Corporate debt
Authors: Young Garry
Published: March 2007

A topic of some current interest to forecasters and policymakers is the extent to which the high levels of corporate indebtedness observed throughout the late-1980s contributed to the recession and whether the still substantial debts of the corporate sector are likely to make the recovery from recession slower than normal. The purpose of this note is to present and provide an interpretation of the evidence bearing on this issue.
Training Fluency: An Essential Factor in Language Acquisition and Use
Authors: Davies Norman F.
Published: March 2007

In language education, three primary aspects of communi cation should be taken into account: accuracy, appropriateness and fluency. The first, long the traditional goal of teaching, has in recent years been weakened by interlanguage theory and the view that a knowledge of usage alone is insufficient. An over emphasis on Monitor-use (Krashen's terminology) may also adversely affect acquisition, lead to slow pacing and an im poverishment of language samples presented in the classroom.

Appropriateness has in recent years been seen as a major factor in achieving communicative competence, now widely accepted (though not always well-defined) as the major goal of language teaching and learning. The rules of use are undoubtedly a suitable field for study but have perhaps been overemphasized by some proponents; they often differ little between related cultures.

To learn language, however, one must use it, and fluency training is the essential but partly neglected third factor in the learning situation. Fluency is essential in the receptive skills, which should be given early priority and trained by constant exposure to and processing of a wide variety of preferably authentic materials. It is desirable in the productive skills, and requires the frequent use of genuine and stimulating communica tive exercises in the classroom, which not only increase fluency but are a major vehicle of language acquisition. Examples are given of methods of training fluency, in the classroom and in the learning laboratory.
Beginning to Learn Foreign Vocabulary: A Review of the Research
Authors: Nation I.S.P.
Published: March 2007

The article is an attempt to provide a comprehensive review of the experimental findings on foreign vocabulary learning. Almost all the research has been carried out on learning word pairs made up of a foreign word paired with its mother- tongue translation. The first section of the review compares direct and indirect vocabulary learning. The second section reviews the evidence on how much vocabulary can be learned in a given time, how many repetitions are required for learning to occur, and why some words are more difficult to learn than others. The section on technique compares the effectiveness of a variety of techniques for receptive and productive vocabulary learning. The article concludes with advice on interpreting ex periments on vocabulary learning.
What We Do and Don't Know about Chinese Learners of English: A Critical Review of Selected Research
Authors: Wong Sau-ling Cynthia
Published: March 2007

This paper is a critical review of selected research on the learning of English by Chinese speakers, in particular, on the difficulties they experience and the variables determining the success of their under taking. Areas of consensus and dispute among researchers, as well as suggestions for needed research, will be pointed out. Emphasis is on analyzing approaches and noting trends. The premise of the paper is that, to whatever extent (as justified by empirical evidence) Chinese speakers may be said to share a common language and culture, such a survey would be helpful to the formulation of lines of inquiry and the development of learner-language-specific methods and materials. Studies of social/affective factors in English acquisition (which are locale-specific) will not be discussed. Topics covered include phono logy, morphology and syntax (and beyond), the typological transfer hypothesis, analysis of written discourse, analysis of spoken discourse and sociocultural competence, and reading.
Learner Involvement and Comprehensible Input1
Authors: Tsui Amy B M
Published: March 2007

Studies on comprehensible input have largely focused on how input is made comprehensible to the non-native speaker (NNS) or the learner by examining native speaker (NS) speech or teacher talk in the classroom. Devices employed to modify the input and interaction have been identified. The quantity of modification devices used has been taken as an indicator of the amount of negotiation work that has gone on and the quantity of comprehensible input. Relatively lit tle has been done on the part played by learners to ensure that the in put that they obtain is comprehensible (see however Gaies 1983; Scarcella & Higa 1981; Varonis & Gass 1985). This paper points out that it is only when the modification devices involve learner parti cipation that they can serve as indicators of the amount of compre hensible input provided and the amount of negotiation of meaning that has taken place. The discussion is illustrated by data from two reading comprehension lessons in secondary schools in Hong Kong.
Simulation of digital control systems on an analog computer with digital logic
Authors: Clemence C.R.
Published: March 2007

This paper describes a procedure for simulation of digital control systems on an analog computer with digital logic. The digital elements are only those normally provided in the digital panel now available as an optional accessory from most analog computer manufacturers. When used in conjunction with the conventional analog amplifiers and integrators connected as track-hold devices, it is possible to simulate complete systems which include not only the straightforward single-rate system but also those having two or more sampling rates or subsystems, and those having delayed or skip sampling characteristics. The digital logic connections for some simple but typical problems are given and are suggestive of those required for more sophisticated applications.

A couple of oscilloscope photographs are included which show the informative presentation which can be obtained with this simulation technique.
The results of a survey of hybrid computer laboratories
Authors: Wheeler Lawrence A.
Published: March 2007

This paper presents the results of a survey of hybrid computer laboratories in the United States and abroad. The survey included personal visits to 15 hybrid computer laboratories and a mailing of 195 questionnaires. The survey questionnaire was design ed to determine the current status of hybrid computer facility configurations, management policies, and facility utilization levels.
Modular design of multicomputer systems
Authors: Unger Brian W. , Bidulock Don S.
Published: March 2007

Multicomputer systems involve complex hardware and software components with extensive interactions. Furthermore, rapid advances in semiconductor tech nology have resulted in many different ways to im plement a system requirement.

The merits of different hardware implementations are difficult to determine at an early stage of design and will often change subsequently. Thus we need design methods that let us delay implementation deci sions as long as possible. The structure of a sys tem, i.e., the definition of major components and their interaction, is often independent of the physi cal implementation. The design of the structure, however, largely determines important system charac teristics such as performance, modularity, reliabil ity, visibility, and adaptability.

We outline a design method based on guidelines that promote modularity and access graphs that specify interactions between components. This method is then applied to a typical example, the design of a network message processor. The processor handles communications in a network of multiple computers and interactive terminals.
Simulating the Energy Requirements of a Country's Industrial Production
Authors: Mosekilde Erik , Meyer Niels I.
Published: March 2007

The rapidly increasing fuel prices and the associat ed changes in our economic conditions will influence the future needs for energy considerably. Histori cal trends for the growth of energy consumption can no longer be expected to continue, and studying the needs for long-term development of energy requires a model that provides an adequate level of detail and includes both technological and economic factors.

our model of the Danish industrial production sec tors divides the energy consumption into four com ponents : space heating, lighting and ventization, process heat, and production processes. Relation ships are included that estimate the cost of saving energy through such measures as improved building insuzation, waste-heat regeneration, cogeneration of steam and electricity, and reduction of the use of process heat. It is assumed that the industry actually institutes those measures that have a re payment time below an adjustable maximum value.

Our model allows experimentation with various scenarios for both general economic conditions and fuel prices. Although the model does not include a complete thermodynamic description of the flow of energy through the system, it does provide insight into the real potential for energy conservation.
The Simulation Data Language (Sdl™)
Authors: Standridge Charles R.
Published: March 2007

The Simulation Data Language (SDL) is a database management system specifically designed for use in simulation. A typical example for the use of SDL is the evaluation of the operations of a job shop. In this example, SDL helps the analyst organize and use data gathered from the shop itself, analyze results independently of model runs, and compare alternative policies. Current applications of SDL include studies of health-care delivery and availability, scheduling of aircraft maintenance, manufacturing of discrete parts, steel production, large-scale socio- economic systems, and river systems. In these applications, SDL helped analysts produce statistical analyses, summaries, and reports of data independent ly of model runs, use data gathered from the real system in their models, decompose large, complex models into component models, provide data collection, post-run data analysis, and report generation capabilities that are transparent to the ultimate user of a special-purpose simulation language.
The Mathematical Structure of an Aquatic Ecosystem Model
Authors: de Caprariis Pascal P.
Published: March 2007

As ecological models become more complex, the ques tion of whether they are stable becomes more diffi cult to answer. Some ecologists believe that a com plex system is more stable than a simple system because it is less dependent on any single path through it. Mathematicians, on the other hand, have shown that systems of equations are more likely to become unstable as the number of equations increases. Neither tendency may apply to ecological systems that include time-varying components and in which the number of significant interactions does not de pend strongly on the number of components.

In the case of the aquatic ecosystem model MS. CLEANER, solutions of the governing differential equations are stable even though the model contains up to 40 state variables and simulates many biologi cal, biochemical, microbial, and chemical processes. The stability is the result of feedback in the system and the sparseness of the interaction matrix. A qualitative analysis of the model shows that the functions used to represent predation have signifi cantly different forms at high, low, and intermediate nutrient levels. The different forms of this func tion cause unique, bounded solutions for high and low nutrient conditions and two stable, periodic solutions for intermediate conditions. The predic tion of a unique solution independent of the initial conditions in one case and more than one stable periodic solution in another case agrees with the published results of simulation.
Applying Software Engineering To Protocol Simulation
Authors: Landwehr Carl E.
Published: March 2007

Communications systems have widely varying equipment, traffic distributions, error characteristics, and measures of performance. To accommodate these characteristics, a simulator for the protocols con trolling the transmission and reception of messages must be modular and flexible ; it must also allow for the handling of concurrent processes and the efficient generation of reports and statistics. One way to construct such a simulator is to use techniques derived from software engineering: design prior to coding, design review, modular design based on information hiding, use of abstract types, code review by peers, co-operating sequential processes, and pseudo-code specifications. In the development of a simulator program for several pro tocols, outside design review, the information- hiding principle, the use of abstract types with a language that supports them (SIMULA), and the use of co-operating sequential processes were the most productive methods.
Providing Statistical Confidence in the Evaluation of Alternatives
Authors: Amer Paul D.
Published: March 2007

A simulation study comparing a set of alternatives should include a confidence statement regarding the accuracy of its results. Statistical ranking and selection procedures can provide such confidence statements. Typical goals for these procedures in clude selecting the best alternative, selecting a subset that includes the best, selecting all alter natives that are better than a control (or base case), selecting all alternatives that are better than a control while also excluding all alternatives that fail to meet a minimum standard, and selecting all alternatives that are better than a standard involving two parameters.

The analyst can use tables to determine how many observations are required to achieve a specified level of confidence in the results. Proportions are generally the best statistics to use because they do not assume any underlying distribution for the data and, in some cases, they summarize distributions more effectively than do such other parameters as the mean or median. Examples show how the procedures were applied in an evaluation of remote-access inter active computer services.
Simulating the Economics of Coal Production
Authors: Burzlaff Bernard H. , Lohrenz John , Monash Ellis A.
Published: March 2007

Simple models of discounted cash flow can simulate production for coal mines with three different geometries: (1) uniform horizontal beds,

(2) horizontal beds with optional incremental seams, and (3) uniform dipping seams. The models assume that investors choose a constant rate and duration of production to maximize present worth. Examples show the effects of policy and economic changes on coal production for each model. The results show that changes which increase variable costs reduce the optimum rate and duration of production. Changes which increase fixed costs, however, do not affect the optimum rate of production but do reduce the ultimate recovery of coal.
Assessing Defense Procurement Policies
Authors: blakley Daniel L. , Cohen Kalman J. , Lewin Arie Y. , Morey Richard C.
Published: March 2007

Defense systems are typically over budget and behind schedule, and they often fail to meet performance specifications despite incentive schemes. Our study shows that these schemes are ineffective primarily because they assume (1) that a contractor's sole criterion is maximizing profit on a contract, and (2) that a single decision maker determines criteria that do not change in the course of system development. In fact, defense contractors have many different criteria, and their relative importance often changes with time.

We have developed a dynamic computer simulation model that accounts for all the major motivations of the defense contractor, some of which are unrelated to any particular contract. It considers how the con tractor interacts, at both the corporate and the project-manager levels, with decision makers at the U.S. Department of Defense (DOD).

The model is a relatively new type called a decision process model. A special feature of the model is that the user can modify the corporate-level and project-level goals of the contractor to better meet DOD goals as stated in the contract. The model can help planners assess the impact of alternative DOD incentive schemes and procurement policies on the per formance of defense contractors.

The model is currently in the third stage of valida tion (statistical and sensitivity analysis). It has already yielded a few tentative results, most of which are strongly supported by field interviews with DOD and defense contractor personnel.
Early Desire
Authors: Korn Granino A.
Published: March 2007

EARLY DESIRE is a new, floating-point equation- language simulation system for Digital Equipment (DEC) PDP-11 and LSI-11 minicomputers. It combines

(1) An interpreted job-control language for inter active program entry, editing, file operations, and multi-run experiments

(2) An efficient, very fast compiler for the time- critical dynamic segment equation solution

(3) Precompiled FORTRAN library routines for dif ferent integration-rule overlays.

EARLY DESIRE needs no external compiler or linker. It executes directly on a RUN command at a speed 1.3 to 4 times faster than DEC RT-11 FORTRAN. Future DESIRE systems will run on 32-bit computers and will employ attached array processors as execution processors.