bluuebunny/crossref_metadata_2025 huggingface dataset:
Local road traffic activity and the prevalence, severity, and persistence of wheeze in school children: combined cross sectional and longitudinal study
Authors: Venn Andrea , Lewis Sarah , Cooper Marie , Hubbard Richard , Hill Ian , Boddy Rachel , Bell Margaret , Britton John
Published: July 2002

OBJECTIVES

To investigate the relation between local road traffic activity and the occurrence, severity, and persistence of wheeze in children.

METHODS

Data on wheeze and asthma were collected in a cross sectional questionnaire survey of 22 968 primary school children (age 4–11) and 27 826 secondary school children (age 11–16) in the Nottingham area. Direct measures of road traffic flow were made in the locality of each school and combined with Local Authority traffic data for major roads to estimate local traffic activity in vehicle metres/day/km2. Assessment of the effects of potential confounders was performed in nested case-control groups of 6576 primary and 5936 secondary children. Data on frequency of wheeze were collected for the cases to study disease severity. Longitudinal data on a historical cohort of 883 children who reported wheeze when aged 4–11 in 1988 were used to study the persistence of wheeze into adolescence.

RESULTS

Unadjusted prevalence of wheeze in the past year within schools varied widely but was not associated with traffic activity in the school locality (weighted regression coefficient β=−0.01, p=0.93 for primary schools, β=−0.18, p=0.26 for secondary schools). The risk of wheeze in individual primary school children was not associated with traffic activity analysed as a continuous variable, although there was some suggestion of a weak, non-linear plateau effect. Similar effects were found for diagnosed asthma and recent cough. There was no evidence of any relation between traffic activity and risk of wheeze in secondary school children. There were positive but non-significant dose related effects of traffic activity on wheeze severity in primary and secondary children and on persistence of wheeze in the longitudinal cohort.

CONCLUSIONS

Traffic activity in the school locality is not a major determinant of wheeze in children.
Mortality among women and men relative to unemployment, part time work, overtime work, and extra work: a study based on data from the Swedish twin registry
Authors: Nylén L , Voss M , Floderus B
Published: July 2002

OBJECTIVE

To examine mortality before 70 years of age among women and men relative to unemployment, part time work, overtime work, and extra work. Age, marital status, children, smoking and alcohol habits, use of sleeping pills and tranquilisers, stress, shift work, personality factors, and long lasting or serious illness were taken into account as potential confounding factors.

METHODS

The study group comprised a subcohort of the Swedish twin registry, people born in 1926–58. Data were based on a postal questionnaire of 1973 and on information from the Swedish Causes of Death Registry. All subjects reporting a main occupation were selected, 9500 women and 11 132 men, and mortality from all causes during 1973–96 was analysed. The subjects were treated as a sample from the general population regardless of the twinning.

RESULTS

Unemployment in 1973 among both women and men showed an association with increased mortality. The adjusted relative risk (RR) (95% confidence interval (95% CI)) was 1.98 (1.16 to 3.38), for women and 1.43 (0.91 to 2.25) for men. For the first 5 years of follow up, a threefold increase in risk was found for men (RR (95% CI) 3.29 (1.33 to 8.17)). The RR declined by time, but remained increased throughout the 24 year study period. In women overtime work of more than 5 hours a week was followed by an increased mortality rate (RR (95% CI) 1.92 (1.13 to 3.25)). A protective effect of moderate overtime work of a maximum 5 hours a week was shown for men (RR (95% CI) 0.58 (0.43 to 0.80)), whereas an increased mortality was indicated for part time work (RR (95% CI) 1.58 (0.91 to 2.77)) and extra work (work outside employment) of more than 5 hours a week (RR (95% CI) 1.29 (0.99 to 1.69)).

CONCLUSION

Unemployment and some time aspects of work were associated with subsequent mortality, even when controlling for social, behavioural, work, and health related factors. The idea that losing a job may have less importance for women than for men is not supported by this study.
Occupational injuries in Italy: risk factors and long term trend (1951–98)
Authors: Fabiano B , Currò F , Pastorino R
Published: July 2002

OBJECTIVES

Trends in the rates of total injuries and fatal accidents in the different sectors of Italian industries were explored during the period 1951–98. Causes and dynamics of injury were also studied for setting priorities for improving safety standards.

METHODS

Data on occupational injuries from the National Organisation for Labour Injury Insurance were combined with data from the State Statistics Institute to highlight the interaction between the injury frequency index trend and the production cycle—that is, the evolution of industrial production throughout the years. Multiple regression with log transformed rates was adopted to model the trends of occupational fatalities for each industrial group.

RESULTS

The ratios between the linked indices of injury frequency and industrial production showed a good correlation over the whole period. A general decline in injuries was found across all sectors, with values ranging from 79.86% in the energy group to 23.32% in the textile group. In analysing fatalities, the trend seemed to be more clearly decreasing than the trend of total injuries, including temporary and permanent disabilities; the fatalities showed an exponential decrease according to multiple regression, with an annual decline equal to 4.42%.

CONCLUSIONS

The overall probability of industrial fatal accidents in Italy tended to decrease exponentially by year. The most effective actions in preventing injuries were directed towards fatal accidents. By analysing the rates of fatal accident in the different sectors, appropriate targets and priorities for increased strategies to prevent injuries can be suggested. The analysis of the dynamics and the material causes of injuries showed that still more consideration should be given to human and organisational factors.
Asbestos fibreyears and lung cancer: a two phase case–control study with expert exposure assessment
Authors: Pohlabeln H , Wild P , Schill W , Ahrens W , Jahn I , Bolm-Audorff U , Jöckel K-H
Published: July 2002

Aims:To assess the cumulative effect of asbestos on lung cancer risk where the exposure is assessed by an expert rating.

Methods:1678 male cases and controls were enrolled in a population based matched case–control study, focused on occupational risk factors, carried out in West Germany. The exposure to asbestos was computed as lifelong working hours. For a validation subsample of 164 matched pairs from this study the intensity of asbestos exposure was further assessed by a panel of experts in order to obtain an estimate of the cumulative exposure on a time by intensity scale (fibreyears). The information on duration of asbestos exposure in the original study was combined with the fibreyears following the two phase case control study paradigm.

Results:The number of exposed subjects in the validation subsample was 75 cases and 71 controls. The percentage of subjects with a cumulative exposure ≤1, 1 to ≤10, and >10 fibreyears was 16%, 15%, and 15% for the cases and 18%, 16%, and 9% respectively for the controls. The smoking adjusted odds ratios for the fibreyears based on an unconditional logistic regression were 0.81, 1.02, and 1.60 respectively with increasing exposure categories (not significant). The coefficient (beta) for a log transformed trend was 1.156. Applying the two phase paradigm, these odds ratios became 0.86, 1.33, and 1.94; the latter reached significance and the beta coefficient was 1.178.

Conclusions:The two phase paradigm allowed us to obtain a more precise estimate of the effect of asbestos on lung cancer. Results are consistent with a doubling of the lung cancer risk with 25 fibreyears asbestos exposure.
Hepatocellular carcinoma
Authors: Badvie Sara
Published: July 2002

Primary hepatocellular carcinoma is one of the 10 most common tumours, and the most common primary liver malignancy, in the world. In the majority of cases, it occurs against a background of hepatitis B or C viral infection and/or liver cirrhosis, and is associated with a dismal prognosis of a few months. Current treatments in routine clinical practice are surgical resection and liver transplantation, but these therapies are applicable to only a small proportion of patients and prolongation of survival is restricted. Other treatment options include intra-arterial chemotherapy, transcatheter arterial chemoembolisation, percutaneous ethanol injection, cryotherapy, thermotherapy, proton therapy, or a wide range of their possible combinations. The current lack of definitive data, however, limits the use of these therapies. Another option is gene therapy, which although in its infancy at the present time, may have a significant role to play in the future management of hepatocellular carcinoma.
Addison's disease in type 1 diabetes presenting with recurrent hypoglycaemia
Authors: McAulay Vincent , Frier Brian M
Published: July 2002

Primary adrenal insufficiency (Addison's disease) often develops insidiously. Although a rare disorder, it is more common in type 1 diabetes mellitus. A 19 year old male with type 1 diabetes and autoimmune hypothyroidism experienced recurrent severe hypoglycaemia over several months, despite a reduction in insulin dose, culminating in an adrenal crisis. Recurrent severe hypoglycaemia resolved after identification and treatment of the adrenocortical insufficiency. In type 1 diabetes, undiagnosed Addison's disease can influence glycaemic control and induce severe hypoglycaemia.
Will an orange a day keep the doctor away?
Authors: Richardson T I L , Ball L , Rosenfeld T
Published: July 2002

An 80 year old man, who relied on a home based meals-on-wheels service was admitted to hospital with non-specific symptoms, but had clinical and biochemical evidence of scurvy. Subsequently, all new admissions (n=37) to the department over a three week period were assessed for evidence of undernutrition. It was found that 73% had hypovitaminosis C, with 30% having concentrations suggestive of scurvy. There were no significant associations between level of vitamin C and type of accommodation, food provision, or age. The commonest symptom associated with vitamin C deficiency was anorexia, but overall, there was a paucity of clinical signs associated with vitamin C deficiency. The possible associations of vitamin C deficiency in the elderly are discussed.
Thaw effects on cold-hardiness parameters in yellow birch
Authors: Zhu X B , Cox R M , Bourque C -PA , Arp P A
Published: July 2002

One-year-old, cold-hardened, container-grown yellow birch (Betula alleghaniensis Britt.) seedlings were exposed to cold treatments after being pretreated with a simulated winter thaw. Freezing injury to roots and shoots was assessed by relative electrolyte leakage and triphenyltetrazolium chloride reduction. Growth characteristics were also determined after 60 days under greenhouse conditions. Relative electrolyte leakage and triphenyltetrazolium chloride reduction measurements showed that roots became increasingly damaged with decreasing cold-treatment temperatures. However, plants pretreated with thaws showed significantly lower stem increment, shoot length, and leaf area in response to the cold temperatures than did the unthawed plants. Variation in these growth parameters was also significantly correlated with both root and shoot freezing injury parameters. Cold hardiness under different thaw pretreatments was assessed using the highest freezing temperature that caused significant injury, referred to as the critical temperature. For seedlings without the thaw pretreatment, shoot and root critical temperatures were estimated as 52.5 and 23.8°C, respectively. Following 12 days of thaw, these temperatures increased to 24.08°C for shoots and 13°C for roots. Twelve days of thaw, or growing degree-day (>4°C) accumulations greater than 66 during a thaw, could sufficiently deharden roots and shoots such that they would be susceptible to freezing damage at ambient temperatures commonly encountered in the Canadian Maritimes. We also observed that root pressure declined significantly with increasing root freezing injury. Sufficient root pressure is required for springtime refilling of xylem embolisms caused by winter cavitation of the vessels in this species. Weak root pressure caused by freezing injury would represent a risk of shoot dieback and tree decline due to the remaining embolisms reducing water flow to the developing foliage. The rapid reduction of shoot cold hardiness may also indicate the threat of late-spring frosts to this species. These induced changes are especially important under climate change scenarios that suggest increases in winter temperatures and changes in seasonality in eastern Canada.Key words: climate change, cold hardiness, electrolyte leakage, growth, root pressure, TTC reduction.
Effects of burial by sand and inundation by fresh- and seawater on seed germination of five tropical beach species
Authors: Martínez M L , Vázquez G , White D A , Thivet G , Brengues M
Published: July 2002

Plants growing on the beach are exposed to substrate mobility, freshwater inundation, and immersion in seawater, which greatly affect germination and species spatial distribution. In greenhouse experiments, we tested whether the most abundant species on the beach at La Mancha (on the Gulf of Mexico) were tolerant to burial and flooding. We buried seeds of Canavalia maritima, Ipomoea pes-caprae, Chamaecrista chamaecristoides, Palafoxia lindenii, and Ambrosia artemisiifolia at different depths. We used fresh- and seawater flooding with two frequencies: permanent and intermittent. The hard-coated seeds of Canavalia, Ipomoea, and Chamaecrista were left scarified and not scarified to test if dormancy was broken by the flooding regimes. Germination decreased as burial depth increased. We calculated a tolerance index for the burial responses, which indicated that Chamaecrista was the most tolerant species, followed by Canavalia and Palafoxia. Flooding inhibited germination, but more so permanent seawater flooding; it was especially lethal for species closest to the ocean such as Canavalia and Ipomoea. After transfer to freshwater, seeds of Chamaecrista, Palafoxia, and Ambrosia germinated. There was no evidence that hard-coat dormancy was broken by flooding. Tolerance to burial seems to be related to the spatial distribution of species but not to germination responses to flooding.Key words: germination, sand burial, freshwater, seawater, flooding, Gulf of Mexico.
Effectiveness of dry ponds for stormwater total suspended solids removal
Authors: Shammaa Y , Zhu D Z , Gyürék L L , Labatiuk C W
Published: July 2002

This paper reviews the factors and criteria for the design of new and the retrofitting of existing dry detention ponds to enhance removal of total suspended solids (TSS) from stormwater. Detention time is discussed as the most important factor affecting TSS removal. Two-stage facilities and multi-level outlet design are important means of enhancing TSS removal in dry ponds. Two dry ponds within the city of Edmonton were selected to evaluate their TSS removal. The level of expected TSS removal is low owing to the relatively short detention times for both ponds. Methods for retrofitting the dry ponds to enhance TSS removal are discussed.Key words: dry pond, stormwater, TSS removal, detention time, retrofitting.
The syntheses and NMR studies of hexadeca- and octaneopentoxyphthalocyanines
Authors: Bhardwaj Namrta , Andraos John , Leznoff Clifford C
Published: July 2002

The syntheses of 3,6-dineopentoxyphthalonitrile and 3,4,5,6-tetraneopentoxyphthalonitrile are described. Condensation of these phthalonitriles with nickel chloride in N,N-dimethylaminoethanol yielded 1,4,8,11,15,18,22,25-octaneopentoxyphthalocyaninato nickel(II) (3) and 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecaneopentoxyphthalocyaninato nickel(II) (7). The 1H NMR spectra of these phthalocyanines and the related 2,3,9,10,16,17,23,24-octaneopentoxyphthalocyaninato nickel(II) (8) at temperatures from 205 to 330 K in toluene-d8 exhibited various degrees of restriction of rotation of the neopentoxy groups. Compound 7 exhibited a single atropisomer at 235 K.Key words: neopentoxy substituted phthalocyanines, variable temperature NMR, restricted rotation.
A new and independently evolved case of xylophagy and the presence of intestinal flagellates in the cockroachParasphaeria boleiriana(Dictyoptera, Blaberidae, Zetoborinae) from the remnants of the Brazilian Atlantic forest
Authors: Pellens R , Grandcolas P , Silva-Neto I Domingos da
Published: July 2002

Parasphaeria boleiriana is a new example of a xylophagous and subsocial cockroach with intestinal flagellates, which was observed in remnants of the Brazilian semideciduous Atlantic forest. Parasphaeria boleiriana formed galleries by burrowing into the rotten trunks of softwood trees in the forest understory. Females stayed in chambers in the wood with their neonate nymphs for 12.4 ± 6.2 days (mean ± SD), but trophallaxis was not yet observed. According to multiseasonal sampling, nymphal development took longer than 1 year, but adults appeared to be short-lived. Nymphs did not disperse within the trunk during their development but remained relatively aggregated. Parasphaeria boleiriana fed on wood, and their digestive tract harboured five species of flagellates belonging to the order Trichomonadida. All these characteristics contrast with those of other known wood-feeding cockroaches, especially the low adult longevity and short period of brood care, associated with a high prevalence of intestinal flagellates.
AN EFFICIENT ALGORITHM FOR CONSTRUCTING MINIMAL COVER AUTOMATA FOR FINITE LANGUAGES
Authors: CAMPEANU CEZAR , PAUN ANDREI , YU SHENG
Published: July 2002

The concept of cover automata for finite languages was formally introduced in [3]. Cover automata have been studied as an efficient representation of finite languages. In [3], an algorithm was given to transform a DFA that accepts a finite language to a minimal deterministic finite cover automaton (DFCA) with the time complexity O(n4), where n is the number of states of the given DFA. In this paper, we review the basic concept of cover automata and describe a new efficient transformation algorithm with the time complexity O(n2), which is a significant improvement from the previous algorithm.
THE LACE EXPANSION FOR SELF-AVOIDING WALK IN FIVE OR MORE DIMENSIONS
Authors: HARA TAKASHI , SLADE GORDON
Published: July 2002

This paper is a continuation of the companion paper [14], in which it was proved that the standard model of self-avoiding walk in five or more dimensions has the same critical behaviour as the simple random walk, assuming convergence of the lace expansion. In this paper we prove the convergence of the lace expansion, an upper and lower infrared bound, and a number of other estimates that were used in the companion paper. The proof requires a good upper bound on the critical point (or equivalently a lower bound on the connective constant). In an appendix, new upper bounds on the critical point in dimensions higher than two are obtained, using elementary methods which are independent of the lace expansion. The proof of convergence of the lace expansion is computer assisted. Numerical aspects of the proof, including methods for the numerical evaluation of simple random walk quantities such as the two-point function (or lattice Green function), are treated in an appendix.
DISCRETE SPECTRUM ASYMPTOTICS FOR THE SCHRÖDINGER OPERATOR WITH A SINGULAR POTENTIAL AND A MAGNETIC FIELD
Authors: SOBOLEV A.V.
Published: July 2002

Object of the study is the operator H=H0(h, µ)+V in L (Rd), d≥2, where H0(h, μ) is the Schrödinger operator with a magnetic field of intensity μ≥0 and the Planck constant h∈(0, h0]. The electric (real-valued) potential V=V(x) is assumed to be asymptotically homogeneous of order −β, β≥0 as x→0. One obtains asymptotic formulae with remainder estimates as h→0, μh≤C for the trace Ms=tr{ɸgs(H)} where [Formula: see text], s∈[0, 1]. Due to the condition μh≤C the leading term of Ms does not depend on μ. It depends on the relation between the parameters d, s and β. There are five regions, in which either leading terms or remainder estimates have different form. In one of these regions Ms admits a two-term asymptotics. In this case, for an asymptotically Coulomb potential the second term coincides with the well-known Scott correction term.
T*-PRODUCT AND FALSE NONCONSERVATION OF ANGULAR MOMENTUM IN THE PION DECAY
Authors: NAKANISHI NOBORU
Published: July 2002

In the framework of the intermediate vector boson theory, developed in the early 1960s, T*-product induces false nonconservation of angular momentum in the π→μ+ν decay. It points out that if correctly formulated, the pion cannot decay and clarifies how this problem can be resolved in the electroweak theory. In this consideration, some unexpected facts are found.
COMPLEXIFIED PSUSY AND SSUSY INTERPRETATIONS OF SOME PT-SYMMETRIC HAMILTONIANS POSSESSING TWO SERIES OF REAL ENERGY EIGENVALUES
Authors: BAGCHI B. , MALLIK S. , QUESNE C.
Published: July 2002

We analyze a set of three PT-symmetric complex potentials, namely harmonic oscillator, generalized Pöschl–Teller and Scarf II, all of which reveal a double series of energy levels along with the corresponding superpotential. Inspired by the fact that two superpotentials reside naturally in order-two parasupersymmetry (PSUSY) and second-derivative supersymmetry (SSUSY) schemes, we complexify their frameworks to successfully account for the three potentials.
A UNION OF THE REAL-SPACE AND RECIPROCAL-SPACE VIEW OF THE GaAs(001) SURFACE
Authors: LaBELLA V. P. , DING Z. , BULLOCK D. W. , EMERY C. , THIBADO P. M.
Published: July 2002

A union of the real-space and reciprocal space view of the GaAs(001) surface is presented. An optical transmission temperature measurement system allowed fast and accurate temperature determinations of the GaAs(001) substrate. The atomic features of the Ga A s (001)-(2×4) reconstructed surface are resolved with scanning tunneling microscopy and first principles density functional theory. In addition, the 2D lattice-gas Ising model within the grand canonical ensemble can be applied to this surface to understand the thermodynamics. An algorithm for using electron diffraction on the GaAs(001) surface to determine the substrate temperature and tune the nanoscale surface roughness is presented.
HARD MAGNETIC PROPERTIES OF MULTILAYERED SmCo/Co PERMANENT MAGNETS
Authors: ANDREESCU R. , O'SHEA M. J.
Published: July 2002

We have prepared (Sm-Co)/Co multilayers with two different Co thicknes to study the hard magnetic properties (coercivity Hci and energy product BHmax ) of nanostructured SmCo magnets consisting of hard SmCo and softer higher moment Co phases. Samples are annealed at a temperature in the range 450 – 700°C, for 20 minutes in vacuum (standard anneal) or rapidly annealed for 30 seconds under flowing nitrogen (rapid anneal) to form the hard Sm-Co phase. We find that samples subjected to a standard anneal at 500°C or a rapid anneal at 650°C show the largest energy products in these thin films, about 21 MG.Oe. This is closely related to the fact that the high field magnetization is highest for these anneal temperatures and decreases at higher anneal temperatures.
EFFECT OF UNDERLAYERS ON THE STRESS OF CU FILMS PREPARED USING IONIZED METAL PLASMA
Authors: LI C. Y. , ZHANG D. H. , WU J. J. , QI D. X. , QIAN Y. , LI W. H. , FOO P. D.
Published: July 2002

We investigated the effect of barrier metals, Ta, TaN and multi-stacked Ta/TaN , on the stress of the late deposited Cu film using ionised-metal plasma (IMP) technique. It was found that the stress of the IMP Cu film is sensitive to the strain or lattice mismatch of the barrier layer underneath. The nitrogen composition incorporated into Ta barrier layer causes tensile strain in the barrier and also the stress in the late deposited Cu film. The Cu film deposited on a multi-stacked Ta/TaN barrier showed the smallest stress due to relaxation of strain in the multi-layer barrier. In addition, the stress was also found sensitive to the annealing temperature. The abrupt change in the stress at high annealing temperatures coincides well with the formation of Cu 3 Si compound.
CARBON NANOCOMPOSITE THIN FILMS PREPARED BY FILTERED CATHODIC VACUUM ARC TECHNIQUE
Authors: TAY B. K. , CHENG Y. H. , LAU S. P. , SHI X.
Published: July 2002

Nanocomposite amorphous carbon (a-C:Me) films including a-C:Ni , a-C:Co , a-C:Ti , a-C:W , a-C:Fe , a-C:Al , and a-C:Si films were deposited using metal-carbon composite target by filtered cathodic vacuum arc (FCVA) technique. Atomic force microscopy (AFM), Raman, and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology and structure of the films. Nanoindenter and surface profilometer were used to determine the hardness, Young's modulus, and internal stress. Contact angle and field emission experiments were used to study the surface energy and field emission properties of the films respectively. The influence of the type of elements and its composition in the target on the structural, mechanical, surface energy, and field emission properties were studied. The incorporation of elements into the films results in the decrease of sp 3 C fraction, internal stress in the deposited films, but the hardness and Young's modulus remains at high level. The effect of non-carbide forming elements in the films on the mechanical properties is more pronounced than that of carbide forming elements. The surface energy of the films increases with incorporating Ni atoms, but decreases after incorporating Fe and Al atoms into the films. After heat treatment, the incorporation of metal into ta-C films can greatly improve the field emission performance.
FINITE DENSITY ALGORITHM IN LATTICE QCD—A CANONICAL ENSEMBLE APPROACH
Authors: LIU KEH-FEI
Published: July 2002

I will review the finite density algorithm for lattice QCD based on finite chemical potential and summarize the associated difficulties. I will propose a canonical ensemble approach which projects out the finite baryon number sector from the fermion determinant. For this algorithm to work, it requires an efficient method for calculating the fermion determinant and a Monte Carlo algorithm which accommodates unbiased estimate of the probability. I shall report on the progress made along this direction with the Padé–Z2 estimator of the determinant and its implementation in the newly developed Noisy Monte Carlo algorithm.
INTERGRANULAR PROPERTIES OF (Y1-x-yZrxCay)Ba2Cu3O7-δ COMPOUNDS
Authors: DEAC I. GR. , BURZO E. , POP A. V. , POP V. , TETEAN R. , KOVACS D. , BORODI G.
Published: July 2002

The intergranular properties of ( Y 1-x-y Zr x Ca y) Ba 2 Cu 3 O 7-δ ceramics were studies by using temperature-dependent ac susceptibility measurements at zero dc magnetic field. The intergranular critical current density was determined from ac susceptibility data by varying the field amplitude H ac . From the imaginary part of the complex susceptibility, χ″(T), we have determined the temperature dependence of the critical current density by using the Bean's model. The ac field dependencies of the intergrain χ″-peak temperatures T p are linear and agree with Müller critical state model. The results were analyzed in terms of superconductor-insulator-superconductor (SIS)-and superconductor-normal-superconductor (SNS)-type models for granular superconductors.
INTERFEROMETRIC MEASUREMENTES OF PHOTOTHERMAL DEFLECTION
Authors: CORONA-ORGANICHE E. , LOPEZ-CRUZ E.
Published: July 2002

The photothermal technique has been applied for the thermal diffusivity measurements. These measurements based on interferometric photothermal deflection effect were made on ZnxCd1-x Te (x = 5%, 10% and 20%). A simple one-dimensional model is presented to obtain the thermal diffusivity for semiconductor materials in the case of a thermally thick sample that is optically opaque.
EXPERIMENTAL AND QUANTITATIVE MODELING STUDIES OF TURING PATTERN FORMATION UNDER STOCHASTIC SPATIAL FLUCTUATIONS
Authors: SANZ-ANCHELERGUES ADOLFO , MUÑUZURI ALBERTO P.
Published: July 2002

We present recent observations of Turing patterns subjected to spatially-correlated noise. Different types of dichotomous spatial noise are discussed in relation with the parameters that characterize it. We show numerical simulations and phase diagrams with the effect produced by all the parameters of the noise.
OPTIMAL CONTROL OF HARVESTING IN A PARABOLIC SYSTEM MODELING TWO SUBPOPULATIONS
Authors: LENHART SUZANNE M. , MONTERO J. A.
Published: July 2002

An optimal harvesting problem for a parabolic partial differential system modeling two subpopulations of the same species is investigated. The two subpopulations are competing for resources. Under conditions on the smallness of the time interval and certain biological parameters, existence and uniqueness of an optimal control pair are established.
A SIMPLE LINE ELEMENT FOR THE DILATON GRAVITY
Authors: ALVES M.
Published: July 2002

The metric for the two-dimensional dilaton gravity can be writen in an alternative form, similar to the two-dimensional Schwarzschild metric, and allow us the identification of some quantitiies with those equivalent in the Schwarzschild solution. This new form, however, presents a nonphysical singularity at the horizon in the same way that in the realistic four dimensional case. We show a procedure to eliminate this horizon singularity and, as an application, the resulting metric is used to obtain the associated Hawking temperature. We discuss also some differents between this metric and the Schwarzschild one.
METRIC–AFFINE GAUGE THEORY OF GRAVITY II: EXACT SOLUTIONS
Authors: HEHL FRIEDRICH W. , MACIAS ALFREDO
Published: July 2002

In continuing our series on metric–affine gravity (see Gronwald, Int. J. Mod. Phys.D6, 263 (1997) for Part I), we review the exact solutions of this theory.
TOPOLOGICAL STRUCTURE OF SELF-SIMILAR SETS
Authors: LUO JUN , RAO HUI , TAN BO
Published: July 2002

We consider the attractor T of injective contractions f1, …, fm on R2 which satisfy the Open Set Condition. If T is connected, then T's interior T° is either empty or has no holes, and T's boundary ∂T is connected; if further T° is non-empty and connected, then ∂T is a simple closed curve, thus T is homeomorphic to the unit disk {x∈R2: |x|≤1}.
OPTIMUM PROCESS MEAN AND SCREENING LIMITS FOR A PRODUCTION PROCESS WITH THREE-CLASS SCREENING
Authors: LEE M. K. , HONG S. H. , KWON H. M. , KIM S. B.
Published: July 2002

The optimum process mean and screening limits are provided for a production process where the accepted item is sold in one of two alternative markets and the rejected item is reworked. All items are subject to screening where the screening variable may be the major quality characteristic of interest (performance variable) or the surrogate variable, which is highly correlated with the performance variable. Each item is classified into three quality grades A, B, and C: grade A items are sold to primary market, grade B items are sold to secondary market, and grade C items are reworked by the same manufacturing process. Assuming that performance and surrogate variables are jointly normally distributed, two profit models are constructed which include selling price, production, inspection, rework and penalty costs. Methods of finding the optimum process mean and the screening limits are presented and an illustrative example is given.
PHOTOINDUCED PRODUCTS IN A C60 MONOLAYER ON ${\rm Si}(111) (\sqrt{3}\times \sqrt{3})\hbox{-}{\rm Ag}$: AN STM STUDY
Authors: NAKAYAMA T. , ONOE J. , NAKATSUJI K. , NAKAMURA J. , TAKEUCHI K. , AONO M.
Published: July 2002

Irradiation of ultraviolet-visible light onto a C 60 monolayer on [Formula: see text] resulted in a chemical reaction between adjacent C 60 molecules, as confirmed by scanning tunneling microscopy (STM) images. The major photoinduced products were double-bonded (two covalent C–C bonds between molecules) C 60 dimers and linear trimers. We also found single-bonded (single covalent bond between molecules) C 60 dimers and linear trimers, and two-dimensional C 60 oligomers as minor products. Observed atomic geometry of the nonbonding contact between a C 60 dimer (or a trimer) and a neighboring dimer (or a trimer), which are parallel to each other regarding their axes, is different from that reported between C 60 molecules in three-dimensional C 60 crystals, where there is no interaction with a substrate.
ASYMMETRIC INFORMATION IN A FINANCIAL MARKET WITH JUMPS
Authors: GRORUD AXEL
Published: July 2002

This paper uses the enlargement of filtrations to analyze the financial strategy of an insider trader in a discontinuous time market where prices are driven by a Brownian motion and a compound Poisson process. We compare this strategy with that of a non-insider trader. The market is a chosen viable and complete; we can give an explicit expression of the optimal portfolio of the insider trader.

On considère un marché financier dont les prix sont dirigés par un mouvement brownien et un processus de Poisson multivarié. Dans ce cadre le marché peut être complet et viable. Nous étudions la stratégie financière d'un agent qui a une information anticipant l'évolution du marché et nous la comparons un agent qui n'a pas cette information. La complétude du marché permet d'expliciter le portefeuille optimal de l'agent initié. Le grossissement de filtration permet de replacer une équation anticipante dans un cadre adapté.
FINANCIAL SIGNAL PROCESSING: A SELF CALIBRATING MODEL
Authors: ELLIOTT ROBERT J. , HUNTER WILLIAM C. , JAMIESON BARBARA M.
Published: July 2002

Previous work on multifactor term structure models has proposed that the short rate process is a function of some unobserved diffusion process. We consider a model in which the short rate process is a function of a Markov chain which represents the "state of the world". This enables us to obtain explicit expressions for the prices of zero-coupon bonds and other securities. Discretizing our model allows the use of signal processing techniques from Hidden Markov Models. This means we can estimate not only the unobserved Markov chain but also the parameters of the model, so the model is self-calibrating. The estimation procedure is tested on a selection of U.S. Treasury bills and bonds.
A SCATTERING THEORY FOR MARKOV CHAINS
Authors: KÜMMERER B. , MAASSEN H.
Published: July 2002

In the operator algebraic formulation of probability theory Markov processes typically appear as perturbations of Bernoulli processes. We develop a scattering theory for this situation. This theory applies to the isomorphism problem between Markov processes and Bernoulli shifts as well as to the description of open quantum systems.
DOMAIN CONTINUITY FOR AN ELLIPTIC OPERATOR OF FOURTH ORDER
Authors: HAYOUNI MOHAMMED , PIERRE MICHEL
Published: July 2002

In this paper, we deal with the continuity with respect to the domain of the solutions of a first boundary value problem of fourth order in dimension 2 and 3. These dimensions are those involved in applications and are critical for this question of continuity. Indeed, continuity holds in dimension 1 thanks to Sobolev embeddings while homogenization may occur in dimensions higher than or equal to 4. Specific phenomena appear in dimensions 2 and 3. Here, we provide a necessary and sufficient condition for continuity with respect to the complementary Hausdorff metric. A main point is that the condition involves only the regularity of the limit domain and not the sequence of approximating domains. We then study various sufficient conditions for continuity in terms of the H2-capacity and we analyze a discontinuous case on an explicit example.
WHY DID THE WORLD TRADE CENTER COLLAPSE? — SIMPLE ANALYSIS
Authors: BAŽANT ZDENĚK P. , ZHOU YONG
Published: July 2002

This paper presents a simplified approximate analysis of the overall collapse of the towers of World Trade Center in New York on September 11, 2001. The analysis shows that if prolonged heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. Despite optimistic simplifying assumptions, the structural resistance is found to be an order of magnitude less than necessary for survival.
STRATEGIC ENVIRONMENTAL ASSESSMENT PERFORMANCE CRITERIA — THE SAME REQUIREMENTS FOR EVERY ASSESSMENT?
Authors: FISCHER THOMAS B.
Published: July 2002

Current interpretations of strategic environmental assessment (SEA) revolve around two main ideas. Firstly, SEA is seen as a concept for improving decision making through the assessment of environmental and potentially other impacts, not following any prescribed form, thus being flexible and leaving ample space for different interpretation. Secondly, a more rational view is taken and SEA is regarded a systematic instrument for improving decision making through assessment of the environmental and potentially other impacts, following a prescribed set of procedural stages and possibly other methodological aspects. Adopting the argument of the latter idea, this paper suggests that SEA performance criteria are not equally valid for every SEA, but differ for three distinct SEA types; policy-SEA, plan-SEA and programme-SEA. In order to provide empirical evidence, 25 assessments for transport and spatial/land use policies, plans and programmes (PPPs) are evaluated, based on the performance criteria introduced by the International Association for Impact Assessment (IAIA) at the Glasgow meeting in 1999 and endorsed in November 2001.
Algorithm 691: Improving QUADPACK automatic integration routines
Authors: Favati Paola , Lotti Grazia , Romani Francesco
Published: July 2002

Two automatic adaptive integrators from QUADPACK (namely, QAG, and QAGS) are modified by substituting the Gauss-Kronrod rules used for local quadrature with recursive monotone stable (RMS) formulas. Extensive numerical tests, both for one-dimensional and two-dimensional integrals, show that the resulting programs are faster, perform less functional evaluations, and are more suitable
Object operations benchmark
Authors: Cattell R. G. G. , Skeen J.
Published: July 2002

Performance is a major issue in the acceptance of object-oriented and relational database systems aimed at engineering applications such as computer-aided software engineering (CASE) and computer-aided design (CAD). Because traditional database systems benchmarks are inapproriate to measure performance for operations on engineering objects, we designed a new benchmark Object Operations version 1 (OO1) to focus on important characteristics of these applications. OO1 is descended from an earlier benchmark for simple database operations and is based on several years experience with that benchmark. In this paper we describe the OO1 benchmark and results we obtained running it on a variety of database systems. We provide a careful specification of the benchmark, show how it can be implemented on database systems, and present evidence that more than an order of magnitude difference in performance can result from a DBMS implementation quite different from current products; minimizing overhead per database call, offloading database server functionality to workstations, taking advantage of large main memories, and using link-based methods.
Creating multisided rational Bézier surfaces using base points
Authors: Warren Joe
Published: July 2002

Rational Be´zier surfaces provide an effective tool for geometric design. One aspect of the theory of rational surfaces that is not well understood is what happens when a rational parameterization takes on the value (0/0, 0/0, 0/0) for some parameter value. Such parameter values are called base points of the parameterization. Base points can be introduced into a rational parameterization in Be´zier form by setting weights of appropriate control points to zero. By judiciously introducing base points, one can create parameterizations of four-, five- and six-sided surface patches using rational Be´zier surfaces defined over triangular domains. Subdivision techniques allow rendering and smooth meshing of such surfaces. Properties of base points also lead to a new understanding of incompatible edge twist methods such as Gregory's patch.
A new inversive congruential pseudorandom number generator with power of two modulus
Authors: Eichenauer-Herrmann Jürgen , Grothe Holger
Published: July 2002

Pseudorandom numbers are important ingredients of stochastic simulations. Their quality is fundamental for the strength of the simulation outcome. The inversive congruential method for generating uniform pseudorandom numbers is a particularly attractive alternative to linear congruential generators, which show many undesirable regularities. In the present paper a new inversive congruential generator with power of two modulus is introduced. Periodicity and statistical independence properties of the generated sequences are analyzed. The results show that these inversive congruential generators perform very satisfactorily.
Distance approximations for rasterizing implicit curves
Authors: Taubin Gabriel
Published: July 2002

In this article we present new algorithms for rasterizing implicit curves, i.e., curves represented as level sets of functions of two variables. Considering the pixels as square regions of the plane, a “correct” algorithm should paint those pixels whose centers lie at less than half the desired line width from the curve. A straightforward implementation, scanning the display array evaluating the Euclidean distance from the center of each pixel to the curve, is impractical, and a standard quad-tree-like recursive subdivision scheme is used instead. Then we attack the problem of testing whether or not the Euclidean distance from a point to an implicit curve is less than a given threshold. For the most general case, when the implicit function is only required to have continuous first-order derivatives, we show how to reformulate the test as an unconstrained global root-finding problem in a circular domain. For implicit functions with continuous derivatives up to orderkwe introduce an approximate distance of orderk. The approximate distance of orderkfrom a point to an implicit curve is asymptotically equivalent to the Euclidean distance and provides a sufficient test for a polynomial of degreeknot to have roots inside a circle. This is the main contribution of the article. By replacing the Euclidean distance test with one of these approximate distance tests, we obtain a practical rendering algorithm, proven to be correct for algebraic curves. To speed up the computation we also introduce heuristics, which used in conjunction with low-order approximate distances almost always produce equivalent results. The behavior of the algorithms is analyzed, both near regular and singular points, and several possible extensions and applications are discussed.
Sequential consistency versus linearizability
Authors: Attiya Hagit , Welch Jennifer L.
Published: July 2002

The power of two well-known consistency conditions for shared-memory multiprocessors,sequential consistencyandlinearizability, is compared. The cost measure studied is the worst-case response time in distributed implementations of virtual shared memory supporting one of the two conditions. Three types of shared-memory objects are considered: read/write objects, FIFO queues, and stacks. If clocks are only approximately synchronized (or do not exist), then for all three object types it is shown that linearizability is more expensive than sequential consistency. We show that, for all three data types, the worst-case response time is very sensitive to the assumptions that are made about the timing information available to the system. Under the strong assumption that processes have perfectly synchronized clocks, it is shown that sequential consistency and linearizability are equally costly. We present upper bounds for linearizability and matching lower bounds for sequential consistency. The upper bounds are shown by presenting algorithms that use atomic broadcast in a modular fashion. The lower-bound proofs for the approximate case use the technique of “shifting,” first introduced for studying the clock synchronization problem.
Evaluation of remote backup algorithms for transaction-processing systems
Authors: Polyzois Christos A. , García-Molina Héctor
Published: July 2002

A remote backup is a copy of a primary database maintained at a geographically separate location and is used to increase data availability. Remote backup systems are typically log-based and can be classified into 2-safe and 1-safe, depending on whether transactions commit at both sites simultaneously or first commit at the primary and are later propagated to the backup. We have built an experimental database system on which we evaluated the performance of the epoch and the dependency reconstruction algorithms, two 1-safe algorithms we have developed. We compared the 1-safe with the 2-safe approach under various conditions.
Fringe analysis revisited
Authors: Baeza-Yates Ricardo A.
Published: July 2002

Fringe analysis is a technique used to study the average behavior of search trees. In this paper we survey the main results regarding this technique, and we improve a previous asymptotic theorem. At the same time, we present new developments and applications of the theory that allow improvements in several bounds on the behavior of search trees. Our examples cover binary search trees, AVL-trees, 2–3 trees, and B-trees.
Algorithm 758: VLUGR2
Authors: Blom J. G. , Trompert R. A. , Verwer J. G.
Published: July 2002

This article deals with an adaptive-grid finite-difference solver for time-dependent two-dimensional systems of partial differential equations. It describes the ANSI Fortran 77 code, VLUGR2, autovectorizable on the Cray Y-MP, that is based on this method. The robustness and the efficiency of the solver, both for vector and scalar processors, are illustrated by the application of the code to two example problems arising from a groundwater-flow model.
MIKE: the menu interaction kontrol environment
Authors: Olsen Dan R.
Published: July 2002

A User Interface Management System (UIMS) called MIKE that does not use the syntactic specifications found in most UIMSs is described. Instead, MIKE provides a default syntax that is automatically generated from the definition of the semantic commands that the interaction is to support. The default syntax is refined using an interface editor that allows modification of the presentation of the interface. It is shown how active pictures can be created by adding action expressions to the viewports of MIKE's windowing system. The implications of MIKE's command-based dialogue description are discussed in terms of extensible interfaces, device and dialogue-style independence, and system support functions.
Computing moments of objects enclosed by piecewise polynomial surfaces
Authors: Gonzalez-Ochoa Carlos , McCammon Scott , Peters Jörg
Published: July 2002

Combining a polynomial free-form surface representation with Gauss' divergence theorem allows efficient and exact calculation of the moments of the enclosed objects. For example, for an cubic representation, volume, center of mass, and the inertia tensor can be computed in seconds even for complex objects with serval thousand patches while change due to local modification of the surface geometry can be computed in real-time as feedback for animation or design. Speed and simplicity of the approach allow solving the inverse problem of modeling to match prescribed moments.