bluuebunny/crossref_metadata_2025 huggingface dataset:
Exercise in preventing falls and fall related injuries in older people: a review of randomised controlled trials
Authors: Gardner Melinda M , Robertson M Clare , Campbell A John
Published: July 2002

Objective—To assess the effectiveness of exercise programmes in preventing falls (and/or lowering the risk of falls and fall related injuries) in older people.

Design—A review of controlled clinical trials designed with the aim of lowering the risk of falling and/or fall injuries through an exercise only intervention or an intervention that included an exercise component

Main outcome measures—Falls, fall related injuries, time between falls, costs, cost effectiveness.

Subjects—A total of 4933 men and women aged 60 years and older.

Results—Eleven trials meeting the criteria for inclusion were reviewed. Eight of these trials had separate exercise interventions, and three used interventions with an exercise programme component. Five trials showed a significant reduction in the rate of falls or the risk of falling in the intervention group.

Conclusions—Exercise is effective in lowering falls risk in selected groups and should form part of falls prevention programmes. Lowering fall related injuries will reduce health care costs but there is little available information on the costs associated with programme replication or the cost effectiveness of exercise programmes aimed at preventing falls in older people.
Effect of body position on measurements of diffusion capacity after exercise
Authors: Stewart Ian B , Potts Jim E , McKenzie Don C , Coutts Ken D
Published: July 2002

Background—Pulmonary diffusing capacity for carbon monoxide (Dlco), alveolar capillary membrane diffusing capacity (Dm), and pulmonary capillary blood volume (Vc) are all significantly reduced after exercise.

Objective—To investigate whether measurement position affects this impaired gas transfer.

Methods—Before and one, two, and four hours after incremental cycle ergometer exercise to fatigue, single breath Dlco, Dm, and Vc measurements were obtained in 10 healthy men in a randomly assigned supine and upright seated position.

Results—After exercise, Dlco, Dm, and Vc were significantly depressed compared with baseline in both positions. The supine position produced significantly higher values over time for Dlco (5.22 (0.13)v4.66 (0.15) ml/min/mm Hg/l, p = 0.022) and Dm (6.78 (0.19)v6.03 (0.19) ml/min/mm Hg/l, p = 0.016), but there was no significant position effect for Vc. There was a similar pattern of change over time for Dlco, Dm, and Vc in the two positions.

Conclusions—The change in Dlco after exercise appears to be primarily due to a decrease in Vc. Although the mechanism for the reduction in Vc cannot be determined from these data, passive relocation of blood to the periphery as the result of gravity can be discounted, suggesting that active vasoconstriction of the pulmonary vasculature and/or peripheral vasodilatation is occurring after exercise.
Interferon γ inhibits growth of human pancreatic carcinoma cells via caspase-1 dependent induction of apoptosis
Authors: Detjen K M , Farwig K , Welzel M , Wiedenmann B , Rosewicz S
Published: July 2002

BACKGROUND AND AIMS

The poor prognosis of pancreatic cancer is partly due to resistance to a broad spectrum of apoptotic stimuli. To identify intact proapoptotic pathways of potential clinical relevance, we characterised the effects of interferon γ (IFN-γ) on growth and survival in human pancreatic cancer cells.

METHODS

IFN-γ receptor expression and signal transduction were examined by reverse transcriptase-polymerase chain reaction (RT-PCR), immunoprecipitation, western blot analysis, and transactivation assays. Effects on cell growth and survival were evaluated in terms of cell numbers, colony formation, cell cycle analysis, DNA fragmentation, and poly(ADP ribose) polymerase (PARP) cleavage.

RESULTS

All four pancreatic cancer cell lines examined expressed functional IFN-γ receptors and downstream effectors, including the putative tumour suppressor interferon regulatory factor 1 (IRF-1). IFN-γ treatment profoundly inhibited anchorage dependent and independent growth of pancreatic cancer cells. Cell cycle analyses revealed subdiploid cells suggesting apoptosis, which was confirmed by demonstration of DNA fragmentation and PARP cleavage. Time and dose dependency of apoptosis induction and growth inhibition correlated closely, identifying apoptosis as the main, if not exclusive, mechanism responsible for growth inhibition. Apoptosis was preceded by upregulation of procaspase-1 and accompanied by proteolytic activation. Furthermore, the caspase inhibitor z-vad-fmk completely prevented IFN-γ mediated apoptosis.

CONCLUSIONS

These results identify an intact proapoptotic pathway in pancreatic cancer cells and suggest that IRF-1 and/or procaspase-1 may represent potential therapeutic targets to be further explored.
Audiometric notch as a sign of noise induced hearing loss
Authors: McBride D I , Williams S
Published: July 2002

OBJECTIVES

To investigate the relation between different types of exposure to noise and a classic sign of noise induced hearing loss (NIHL), the audiometric notch.

METHODS

The study sample had exposure to both continuous and impulse noise and was drawn from a population of electrical transmission workers. Audiograms, taken as part of a hearing conservation programme, were read by three clinicians experienced in the assessment of NIHL. Working independently and using their clinical judgment, they were asked to identify localised increases in the threshold of hearing (audiometric notches) which they would attribute to noise, had a suitable history of exposure been elicited. Prevalent cases of NIHL were identified by the presence of a notch in either ear. Risk factors for NIHL were assessed by a questionnaire which sought information about exposure to air blast circuit breaker noise; firearms; explosions, and continuous noise. The odds of exposure to these factors in those with and without hearing loss were calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.

RESULTS

Of the 648 questionnaires sent out 357 were returned, a response rate of 55%. Of these, at least two out of the three assessors identified 175 (49%) people with a notch at any audiometric frequency. There was no association between these cases and the NIHL risk factors identified by the questionnaire, but a further frequency specific analysis showed a small proportion of people (15 (4%)) with notches at 4 kHz who had the expected associations with exposure to noise and a significant OR for firearms of 4.25 (95% CI 1.28 to 14.1). The much larger proportion of people with 6 kHz notches (110 (31%)) did not show these associations.

CONCLUSIONS

To diagnose NIHL it is important to elicit a detailed and accurate history of exposure to noise: although the notch at 4 kHz is a well established clinical sign and may be valuable in confirming the diagnosis, the 6 kHz notch is variable and of limited importance.
Serum hepatic biochemical activity in two populations of workers exposed to styrene
Authors: Brodkin C A , Moon J-D , Camp J , Echeverria D , Redlich C A , Willson R A , Checkoway H
Published: July 2002

OBJECTIVE

To determine whether hepatic biochemical changes, as measured by routinely available tests indicative of hepatocellular necrosis, cholestasis, or altered hepatic clearance of bilirubin, occur in association with low to moderate exposure to styrene commonly experienced in industrial production.

METHODS

Two independent cross sectional studies were performed comparing serum hepatic transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), cholestatic enzymes (alkaline phosphatase (AP) and γ glutamyl transpeptidase (GGT)), and bilirubin in (a) 47 workers of fibreglass reinforced plastics who were exposed to styrene and (b) 21 boat and tank fabricators, with separate referent groups of unexposed workers. Exposure to styrene was assessed in air by dosimetry, and in venous blood by headspace analysis. Hepatic biochemical variables were assessed across strata of exposure to styrene defined as 25 ppm in air, or 0.275 mg/l in blood, adjusting for age, sex, body mass index, and ethanol consumption.

RESULTS

A consistent and significant linear trend for increasing direct bilirubin and direct/total bilirubin ratio was found in association with increasing exposure to styrene, by both air and blood monitoring, in both studies. Mean direct bilirubin concentrations increased from 0.05–0.08 mg% in referents to 0.12–0.19 in workers exposed above 25 ppm, with a significant exposure-response trend (p<0.005). Significantly increased direct/total bilirubin ratios, ranging from 0.22 to 0.35 were associated with exposure to styrene (p<0.001), indicating diminished hepatic clearance of conjugated bilirubin. Also, a significant linear association between the hepatic transaminases ALT and AST and exposure to styrene was found in pooled regression analyses, with an increase in AP of about 10 IU/ml in workers exposed above 25 ppm air or 0.275 mg/l blood styrene in pooled analyses from both studies.

CONCLUSIONS

The consistent finding of increased direct bilirubin and AP concentrations in these two independent studies provides evidence for diminished hepatic clearance of conjugated bilirubin with associated cholestasis in workers exposed to styrene. The finding of a significant linear association between hepatic transaminase concentrations and exposure to styrene in pooled analyses is consistent with mild hepatic injury and associated metabolic dysfunction.
Decreased white blood cell counts in semiconductor manufacturing workers in Taiwan
Authors: Luo J-C J , Hsieh L L , Chang M J W , Hsu K-H
Published: July 2002

Objectives: To assess the systematic health effects on the liver, kidney, and haematological function tests of workers in semiconductors in Taiwan.

Methods: 926 workers of a semiconductor plant in Taiwan in July 1995 were investigated. Complete blood tests including liver, kidney, and haematological functions were available from 227 workers.

Results: There was a significantly lower mean (SD) white blood cell (WBC) count in male workers of photolithography (5870 (1190)/mm3, p=0.003) and implantation (6190 (1150)/mm3, p=0.018) than that of male control workers (7350 (1660)/mm3). There was a significantly higher prevalence of leukopenia in male photolithography workers (6 of 20; 30%) than in male control workers (1 of 18; 5.6%), the crude odds ratio (OR) was 7.3 (95% confidence interval (95% CI) 1 to 55.6), and the multivariate adjusted OR was 8.1 (95% CI 0.83 to 78.3). The tests for serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), γ glutamyl transferase (RGT), and creatinine were not significant among male workers. Female workers in photolithography had abnormal SGPT and RGT of borderline significance, the multivariate adjusted ORs were 9.6 (95% CI 0.86 to 107) and 6.35 (95% CI 0.53 to 75.8), respectively.

Conclusions: This study suggests that leukopenia is a potential health effect in male fabrication workers of the semiconductor industry. The tasks of the process, maintenance, and equipment engineers which consisted mostly of men put them at risk for intermittent short term peak exposure to glycol ethers, ionising radiation, arsenic, or other toxins. The findings of this medical surveillance are significant; however, a further investigation of the aetiological factors and the subsequent health effects is necessary.
Pericardial tamponade caused by Pasteurella multocida infection after a cat bite
Authors: Al-Allaf A K , Harvey T C , Cunnington A R
Published: July 2002

An unusual case of meningitis and pericardial tamponade caused by Pasteurella multocida after a cat bite is reported. The patient was successfully treated by antibiotics and pericardiocentesis and made an uneventful recovery from a life threatening condition. This case illustrates the potential dangers that can arise from a seemingly trivial and commonplace injury.
Smoking cessation activities by general practitioners and practice nurses
Authors: McEwen Andy , West Robert
Published: July 2002

OBJECTIVES

To assess general practitioners' and practice nurses' self reported behaviour, attitudes, and knowledge in relation to smoking cessation.

DESIGN AND SETTING

Two postal surveys of random national samples of 303 GPs (survey 1) and 459 practice nurses (survey 2) covering England and Wales; effective response rates were 75% and 96%, respectively.

RESULTS

Survey 1 found that 96% of GPs accepted that intervening against smoking was part of their role and almost all (99%) said that they recorded smoking status when patients registered; 57% reported that they routinely updated their records on smoking status, 50% said they advised smokers to stop during most or all consultations, and 76% said they advised smokers to cut down if they cannot stop. A large majority (83%) said they either recommended or prescribed nicotine replacement therapy (NRT). Although most GPs (86%) thought that NRTs were effective, only a minority thought they were worth the cost (47%) or should be on National Health Service (NHS) prescription (32%). There was little evidence that previous training in smoking cessation was associated with more activity, more positive attitudes, or greater knowledge. Survey 2 found that almost all practice nurses (99%) agreed that intervening against smoking was part of their role and 95% said they advised patients to stop at least occasionally; 71% said they advised smokers to stop at most or all consultations. A majority (74%) said that they recommended NRT to their patients. As with the GPs most practice nurses thought that nicotine replacement was effective (79%), but fewer (42%) thought the cost was justified, and only about half (53%) thought it should be available on NHS prescription. Nurses who said they had been trained in smoking cessation engaged in more activity relating to smoking cessation, had more positive attitudes, and were more knowledgeable.

CONCLUSION

GPs and practice nurses accepted that intervening with smoking was an important part of their role and a large majority reported that they intervened at least with some smokers. This represents a promising baseline from which to proceed in terms of implementation of the new smoking cessation guidelines, but it is hoped that improvements can be made in terms of the frequency of updating records and intervening, and acceptance of the cost-effectiveness of NRT as a life preserving intervention.
S1 satellite DNA as a taxonomic marker in brown frogs: molecular evidence that Rana graeca graeca and Rana graeca italica are different species
Authors: Picariello Orfeo , Feliciello Isidoro , Bellinello Renato , Chinali Gianni
Published: July 2002

The brown frog Rana graeca was believed to be present in two areas, the Balkan Peninsula and the Italian Apennines. We have characterised the S1 satellite DNA family from Rana graeca graeca and compared it with that of Rana graeca italica. On Southern blots, the patterns of S1 satellite DNA bands are very different between Italian and Greek specimens, but homogeneous among various populations of the same taxon. The satellite DNA from the Greek taxon contains two repetitive units (S1a (494 bp) and S1b (363 bp)) that could be sequenced after amplification from genomic DNA to directly yield their consensus sequences in each genome. These consensus sequences were very similar among the Greek populations, but differed either in sequence (in S1a) or in both size and sequence (in S1b) from the corresponding repeats of the Italian taxon. A mechanism of concerted evolution is likely responsible for the high homogeneity of S1a and S1b repeat sequences within each genome and species. The genomic content of S1 satellite DNA was lower in the Greek than in the Italian populations (0.5 vs. 1.9%) and fluorescence in situ hybridization (FISH) analysis showed the S1 satellite on only 4 chromosome pairs in the Greek taxon and on all 13 chromosome pairs in the Italian taxon. The completely different structure and genomic organization of the S1 satellite DNA indicate that the Greek and Italian taxa are distinct species: R. graeca and R. italica.Key words: satellite DNA, DNA sequence, Southern blot, FISH, Rana.
Analysis of strong and weak ground motions recorded at two sites during Loma Prieta earthquake by wavelet transform
Authors: Rezai Mahmoud , Ventura Carlos E
Published: July 2002

This paper explores the applicability of wavelet transform for the analysis of strong and weak ground motions recorded on rock at Yerba Buena Island and on dredged sandfill at nearby Treasure Island about 2 km away during the 1989 Loma Prieta earthquake in California. An interpretation of the results from this analysis is presented and discussed. The major important feature of this data set is that liquefaction occurred at the Treasure Island site during the strong shaking. The Daubechies 20-coefficient wavelet transform is utilized in this study. Results of the application of the wavelet transform can be summarized as follows: most of the energy of the earthquake at the Treasure Island site is in the frequency range of 0.581.77 Hz and arrives in the time interval between 11 and 15 s. For the Yerba Buena Island site, most of the energy lies within the frequency range of 1.153.53 Hz and arrives between 8 and 13 s. The analysis indicates that there are some large peaks at the highest resolution in the wavelet transforms at the Treasure Island site, which can be attributed to a progressive change in the stiffness characteristics of the soil.Key words: wavelet transform, Fourier transform, frequency content, wavelet scale, site response.
ENTROPY OF BOGOLIUBOV AUTOMORPHISMS OF CAR AND CCR ALGEBRAS WITH RESPECT TO QUASI-FREE STATES
Authors: NESHVEYEV S. V.
Published: July 2002

We compute the dynamical entropy of Bogoliubov automorphisms of CAR and CCR algebras with respect to arbitrary gauge-invariant quasi-free states. This completes the research started by Størmer and Voiculescu, and continued in works of Narnhofer–Thirring and Park–Shin.
APPLICATIONS OF EXACT RENORMALIZATION GROUP TECHNIQUES TO THE NON-PERTURBATIVE STUDY OF SUPERSYMMETRIC GAUGE FIELD THEORY
Authors: ARNONE S. , CHIANTESE S. , YOSHIDA K.
Published: July 2002

Exact Renormalization Group techniques are applied to supersymmetric models in order to get some insights into the low energy effective actions of such theories. Starting from the ultra-violet finite mass deformed N=4 supersymmetric Yang Mills theory, one varies the regularising mass and compensates for it by introducing an effective Wilsonian action. (Polchinski's) renormalization group equation is modified in an essential way by the presence of rescaling (a.k.a. Konishi) anomaly, which is responsible for the beta-function. When supersymmetry is broken up to N=1 the form of effective actions in terms of massless fields is quite reasonable, while in the case of the N=2 model we appear to have problems related to instantons.
EFFECT OF PRESSURE ON INTERLAYER COUPLING AND SUPERCONDUCTING TRANSITION TEMPERATURE OF Bi-2201 AND Bi-2212
Authors: YURGENS AUGUST , WINKLER DAG , CLAESON TORD , MURAYAMA TAKASHI , ANDO YOICHI
Published: July 2002

We used the hydrostatic pressure P<1 GPa as a tool to change the c-axis interlayer coupling of Bi 2 Sr 1.5 La 0.5 CuO 6+δ (Bi-2201) and Bi 2 Sr 2 CaCu 2 O 8+δ (Bi-2212) single crystals. The c-axis critical current, as a measure of the interlayer coupling, drastically increases with pressure (up to 270% GPa -1). The superconducting critical temperature, on the contrary, only slightly increases with a rate of ≈ 2 - 6% GPa -1, This implies that the CuO-interlayer coupling has little effect on Tc in Bi-2201.
IR SPECTRAL INVESTIGATION OF THE xCuO(100 - x)[2B2O3 · As2O3] GLASS SYSTEM
Authors: ARDELEAN I. , CICEO-LUCACEL RALUCA
Published: July 2002

The infrared (FT–IR) absorption spectra for the glasses of the x CuO (100 - x)[ 2B 2 O 3 · As 2 O 3] system with 0 ≤ x ≤ 30 mol% CuO were measured in the wave number region 500–4000 cm -1 at room temperature following the KBr pellet techniques. The aim was to obtain information about the influence of CuO on the local order of the 2B 2 O 3 · As 2 O 3 glass matrix. The interpretation of the obtained vibrational spectra revealed the presence of BO 3, BO 4 units, boroxol rings and the monoclinic form of vitreous As 2 O 3 in the structure of investigated glasses.
TEACHING IMAGE COMPUTATION: FROM COMPUTER GRAPHICS TO COMPUTER VISION
Authors: DRAPER BRUCE A. , BEVERIDGE J. ROSS
Published: July 2002

This paper describes a course in image computation that is designed to follow and build up an established course in computer graphics. The course is centered on images: how they are generated, manipulated, matched and symbolically described. It builds on the student's knowledge of coordinate systems and the perspective projection pipeline. It covers image generation techniques not covered by the computer graphics course, most notably ray tracing. It introduces students to basic image processing concepts such as Fourier analysis and then to basic computer vision topics such as principal components analysis, edge detection and symbolic feature matching. The goal is to prepare students for advanced work in either computer vision or computer graphics.
CONTROL AND SYNCHRONIZATION OF SPACE EXTENDED DYNAMICAL SYSTEMS
Authors: BRAGARD J. , BOCCALETTI S. , ARECCHI F. T.
Published: July 2002

We discuss the issues of controlling and synchronizing continuous space extended systems in the case of two bidirectionally coupled fields, each one obeying one-dimensional CGL. When the two equations are identical, control and synchronization are achieved by means of a finite number of local tiny perturbations, selected by an adaptive technique. We address the problem of the minimum number of local perturbations needed to realize control and synchronization. When the two equations are nonidentical, we show how to induce the appearance of different kinds of synchronized states, depending on the difference in the uncoupled dynamical regimes of the considered fields. Finally, we discuss the role of space-time defects in mediating the process leading to perfect synchronization between the two systems.
APPEARANCE AND DISAPPEARANCE OF A DOVETAIL STRUCTURE IN THE PARAMETER PLANE OF AN n-DIMENSIONAL MAP
Authors: CARCASSÈS J. P. , KAWAKAMI H.
Published: July 2002

A dovetail structure is made up of two cusp points located on a same fold bifurcation curve in a parameter plane of a discrete dynamical system defined by a differentiable map. When a third parameter varies, an existing dovetail structure may disappear by the merging of the two cusp points, or a dovetail structure may appear by the creation of two cusp points on a locally smooth fold bifurcation curve. This paper presents a method permitting to determine the value of the third parameter at which a dovetail structure may appear or disappear in n-dimensional systems. The exposed method is based on the definition of a new singular point, called E-point, belonging to a fold bifurcation curve.
MASTER STABILITY FUNCTIONS FOR SYNCHRONIZED COUPLED SYSTEMS
Authors: PECORA LOUIS M. , CARROLL THOMAS L.
Published: July 2002

We show that many coupled oscillator array configurations considered in the literature can be put into a simple form so that determining the stability of the synchronous state can be done by a master stability function which solves, once and for all, the problem of synchronous stability for many couplings of that oscillator.
COMPUTATION IN WORD-HYPERBOLIC GROUPS
Authors: EPSTEIN DAVID B. A. , HOLT DEREK F.
Published: July 2002

We describe two practical algorithms for computing with word-hyperbolic groups, both of which we have implemented. The first is a method for estimating the maximum width, if it exists, of geodesic bigons in the Cayley graph of a finitely presented group G. Our procedure will terminate if and only this maximum width exists, and it has been proved by Papasoglu that this is the case if and only if G is word-hyperbolic. So the algorithm amounts to a method of verifying the property of word-hyperbolicity of G. The aim of the second algorithm is to compute the thinness constant for geodesic triangles in the Cayley graph of G. This seems to be a much more difficult problem, but our implementation does succeed with straightforward examples. Both algorithms involve substantial computations with finite state automata.
BRANS–DICKE THEORY IN BIANCHI III MODEL AND INFLATIONARY SCENARIO
Authors: CHAKRABORTY NARAYAN CHANDRA , CHAKRABORTY SUBENOY
Published: July 2002

Brans–Dicke theory with perfect fluid model has been considered in Bianchi III space–time and exact analytical solutions are presented with barotropic equation of state. These solutions have been analyzed and some of them have shown the properties of inflationary scenario.
HAMILTONIAN ANALYSIS OF POINCARÉ GAUGE THEORY: HIGHER SPIN MODES
Authors: YO HWEI-JANG , NESTER JAMES M.
Published: July 2002

We examine several higher spin modes of the Poincaré gauge theory (PGT) of gravity using the Hamiltonian analysis. The appearance of certain undesirable effects due to nonlinear constraints in the Hamiltonian analysis are used as a test. We find that the phenomena of field activation and constraint bifurcation both exist in the pure spin 1 and the pure spin 2 modes. The coupled spin-0- and spin-2- modes also fail our test due to the appearance of constraint bifurcation. The "promising" case in the linearized theory of the PGT given by Kuhfuss and Nitsch1 likewise does not pass. From this analysis of these specific PGT modes we conclude that an examination of such nonlinear constraint effects shows great promise as a strong test for this and other alternate theories of gravity.
VISCOUS COSMOLOGICAL MODELS IN (1 + 1) DIMENSIONS
Authors: PAUL B. C. , MUKHERJEE S. , BEESHAM A.
Published: July 2002

Cosmological solutions in (1 + 1) dimensions in the theory of gravity given by Mann have been obtained in the presence of dissipative phenomena. We have studied both the truncated Israel–Stewart theory and the full causal theory in these lower dimensions. In the full causal theory, we discuss two cases, one with the temperature obeying a power law behavior and the other without this assumption. Some of the solutions found in the truncated Israel–Stewart theory and in the full causal theory are comparable to those obtained by Chimento and Cossarini in (1 + 1) dimensions in Eckart theory.
HYPERSURFACE DYNAMICS IN GENERAL RELATIVITY
Authors: MAIA M. D.
Published: July 2002

Coordinate gauge independent deformations are used as the basis of a dynamical theory of hypersurfaces in general relativity. York's relation as derived from those deformations, is taken together with the integrability conditions of the hypersurface as primary conditions to determine Hamilton's equations.
COLOR SUPERCONDUCTIVITY AT FINITE DENSITY AND TEMPERATURE WITH FLAVOR ASYMMETRY
Authors: KIRIYAMA O. , YASUI S. , TOKI H.
Published: July 2002

Color superconductivity of QCD at finite density, temperature and flavor asymmetry is studied within an approximation where the interaction is modeled upon four-fermion interactions. We calculate the thermodynamic potential in the so-called NJL-type model and study the phase structure at finite density, temperature and flavor asymmetry. We find that a mixed phase appears at sufficiently large flavor asymmetry and low temperature. A tricritical point in the T–μB–μI plane is also found.
A MODEL FOR PROGRAM ERROR PREDICTION BASED ON TESTING CHARACTERISTICS AND ITS EVALUATION
Authors: ESAKI KAZUHIRO , TAKAHASHI MUNEO
Published: July 2002

There are two types of models for predicting software reliability at the end of testing. One is the software reliability growth model (dynamic model) based on a given set of time series data. The other is the software complexity model (static model) based on the development environmental factors which have an influence on the software reliability. As the dynamic model depends on the time factor and the test method used, its prediction accuracy does not necessarily correspond to the data of practical projects. On the other hand, the static model needs the many significant parameters to accurately predict the software reliability. However, it is very difficult to select the main factors that determine the significant parameters out of a great number of factors which affect software reliability. In order to resolve these problems, this paper proposes a model to predict the number of embedded errors in a program at the end of testing phase. This model is based on the testing characteristics such as error detection rate and test case density. The result of an experiment shows that the proposed model is more reliable than the conventional models.
A HISTORICAL PERSPECTIVE ON RESEARCH IN PROBABILISTIC CONCEPTS OF AGING
Authors: BARLOW RICHARD E.
Published: July 2002

In this note, the early research in reliability is reviewed. The focus is on the theoretical development of aging and reliability bounds. Some conceptual issues with the interpretation of subjective reliability are also discussed.
TRIANGULAR MATRIX REPRESENTATIONS OF SEMIPRIMARY RINGS
Authors: BIRKENMEIER GARY F. , KIM JIN YONG , PARK JAE KEOL
Published: July 2002

In this paper we characterize internally a TSA ring (i.e. a generalized triangular matrix ring with simple Artinian rings on the diagonal) in terms of its prime ideals. Also we show that the class of semiprimary quasi-Baer rings is a proper subclass of the class of TSA rings. Moreover, we generalize results of Harada, Small, and Teply on semiprimary rings. Finally we prove that under certain cardinality conditions a semiprimary quasi-Baer ring becomes semisimple Artinian.
The weighted region problem
Authors: Mitchell Joseph S. B. , Papadimitriou Christos H.
Published: July 2002

The problem of determining shortest paths through a weighted planar polygonal subdivision with
n
vertices is considered. Distances are measured according to a weighted Euclidean metric: The length of a path is defined to be the weighted sum of (Euclidean) lengths of the subpaths within each region. An algorithm that constructs a (restricted) “shortest path map” with respect to a given source point is presented. The output is a partitioning of each edge of the subdivion into intervals of ε-optimality, allowing an ε-optimal path to be traced from the source to any query point along any edge. The algorithm runs in worst-case time
O
(
ES
) and requires
O
(
E
) space, where
E
is the number of “events” in our algorithm and
S
is the time it takes to run a numerical search procedure. In the worst case,
E
is bounded above by
O
(
n
4
) (and we give an Ω(
n
4
) lower bound), but it is likeky that
E
will be much smaller in practice. We also show that
S
is bounded by
O
(
n
4
L
), where
L
is the precision of the problem instance (including the number of bits in the user-specified tolerance ε). Again, the value of
S
should be smaller in practice. The algorithm applies the “continuous Dijkstra” paradigm and exploits the fact that shortest paths obey Snell's Law of Refraction at region boundaries, a local optimaly property of shortest paths that is well known from the analogous optics model. The algorithm generalizes to the multi-source case to compute Voronoi diagrams.
Modularity of cycles and paths in graphs
Authors: Arkin E. M. , Papadimitriou C. H. , Yannakakis M.
Published: July 2002

Certain problems related to the length of cycles and paths modulo a given integer are studied. Linear-time algorithms are presented that determine whether all cycles in an undirected graph are of length
P
mod
Q
and whether all paths between two specified nodes are of length
P
mod
Q
, for fixed integers
P
.
Q
. These results are compared to those for directed graphs.
A flexible thinning algorithm allowing parallel, sequential, and distributed application
Authors: Olszewski Jan
Published: July 2002

A parallel thinning algorithm for digital patterns is presented. This algorithm can also be used for sequential thinning without the simulation of parallel computation. The mathematical background of the algorithm bases on the notion of the Euler characteristic. The proposed algorithm is simple and particularly faster than other parallel algorithms.
A unifying framework for distributed simulation
Authors: Bagrodia R. , Chandy K. M. , Liao Wen Toh
Published: July 2002

A theory of distributed simulation applicable to both discrete-event and continuous simulation is presented. It derives many existing simulation algorithms from the theory and describes an implementation of a new algorithm derived from the theory. A high-level discrete-event simulation language has been implemented, using the new algorithm, on parallel computers; performance results of the implementation are also presented.
Algorithm 710: FORTRAN subroutines for computing the eigenvalues and eigenvectors of a general matrix by reduction to general tridiagonal form
Authors: Dongarra J. J. , Geist G. A. , Romine C. H.
Published: July 2002

This paper describes programs to reduce a nonsymmetric matrix to tridiagonal form, to compute the eigenvalues of the tridiagonal matrix, to improve the accuracy of an eigenvalue, and to compute the corresponding eigenvector. The intended purpose of the software is to find a few eigenpairs of a dense nonsymmetric matrix faster and more accurately than previous methods. The performance and accuracy of the new routines are compared to two EISPACK paths: RG and HQR-INVIT. The results show that the new routines are more accurate and also faster if less than 20 percent of the eigenpairs are needed.
The envoy framework
Authors: Palaniappan Murugappan , Yankelovich Nicole , Fitzmaurice George , Loomis Anne , Haan Bernard , Coombs James , Meyrowitz Norman
Published: July 2002

The Envoy Framework addresses a need for computer-based assistants or agents that operate in conjunction with users' existing applications, helping them perform tedious, repetitive, or time-consuming tasks more easily and efficiently. Envoys carry out missions for users by invoking envoy-aware applications called operatives and inform users of mission results via envoy-aware applications called informers. The distributed, open architecture developed for Envoys is derived from an analysis of the best characteristics of existing agent systems. This architecture has been designed as a model for how agent technology can be seamlessly integrated into the electronic desktop. It defines a set of application programmer's interfaces so that developers may convert their software to envoy-aware applications. A subset of the architecture described in this paper has been implemented in an Envoy Framework prototype.
A quadratic-tensor model algorithm for nonlinear least-squares problems with linear constraints
Authors: Hanson R. J. , Krogh Fred T.
Published: July 2002

A new algorithm is presented for solving nonlinear least-squares and nonlinear equation problems. The algorithm is based on approximating the nonlinear functions using the quadratic-tensor model proposed by Schnabel and Frank. The problem statement may include simple bounds or more general linear constraints on the unknowns. The algorithm uses a trust-region defined by a box containing the current values of the unknowns. The objective function (Euclidean length of the functions) is allowed to increase at intermediate steps. These increases are allowed as long as our predictor indicates that a new set of best values exists in the trust-region. There is logic provided to retreat to the current best values, should that be required. The computations for the model-problem require a constrained nonlinear least-squares solver. This is done using a simpler version of the algorithm. In its present form the algorithm is effective for problems with linear constraints and dense Jacobian matrices. Results on standard test problems are presented in the Appendix. The new algorithm appears to be efficient in terms of function and Jacobian evaluations.
An execution/sleep scheduling policy for serving an additional job in priority queueing systems
Authors: Leung Kin K.
Published: July 2002

In a priority-based computer system, besides the regular jobs, an additional job (refereed to as
job A
) is invoked infrequently but requires a significant amount of CPU time. To avoid CPU hogging, job A receives (up to) a fixed amount of CPU time whenever it is served. When the time expires, job A immediately relinquishes the CPU and puts itself to sleep for a period of time. By doing so, jobs with low priority may be processed in a timely manner. When the sleep time is over, job A is awakened and waits to resume service according to its priority. Then, the whole process is repeated until job A service is completed. In this paper, such an
execution/sleep
(ES) scheduling policy is analyzed for serving job A in a
nonpreemptive priority queuing
system. The Laplace Transforms are derived for: (i) the conditional response time of job A and (ii) the response time for jobs with priorities higher and lower than job A.

This work is motivated by the ES policy in a switching system in which job A is invoked in response to the failure of signaling links. The proposed model is applicable to other real-time computer systems, and the modeling techniques can be applied or generalized to analyzing other scheduling policies in which timers are involved.
Algorithm 714: CELEFUNT: a portable test package for complex elementary functions
Authors: Cody W. J.
Published: July 2002

This paper discusses CELEFUNT, a pakage of Fortran programs for testing complex elementary functions.
Performance analysis of file organizations that use multibucket data leaves with partial expansions
Authors: Matsliach Gabriel
Published: July 2002

We present an exact performance analysis, under random insertions, of file organizations that use multibucket data leaves and perform partial expansions before splitting. We evaluate the expected disk space utilization of the file and show how the expected search and insert costs can be estimated. The analytical results are confirmed by simulations. The analysis can be used to investigate both the dynamic and the asymptotic behaviors.
Algorithm 718: A FORTRAN subroutine to solve the eigenvalue allocation problem for single-input systems
Authors: Miminis George , Reid Michael
Published: July 2002

An efficient implementation of an algorithm for the eigenvalue allocation (pole placement) problem of single-input linear systems using state feedback is given in this paper. The implementation uses the BLAS level-1 [2] subroutines when possible for better performance. A brief description of the algorithm along with some computational details is also given.
On the sojourn time distribution in a finite capacity processor shared queue
Authors: Knessl Charles
Published: July 2002

We consider a processor shared M/M/1 queue that can accommodate at most a finite number
K
of customers. Using singular perturbation techniques, we construct asymptotic approximations to the distribution of a customer's sojourn time. We assume that
K
is large and treat several different cases of the model parameters and also treat different time scales. Extensive numerical comparisons are used to back up our asymptotic formulas.—
Author's Abstract
Semantics of constraint logic programs with optimization
Authors: Marriott Kim , Stuckey Peter J.
Published: July 2002

Many applications of constraint logic programming (CLP) languages require not only testing if a set of constraints is satisfiable, but also finding the optimal solution which satisfies them. Unfortunately, the standard declarative semantics for CLP languages does not consider optimization but only constraint satisfaction. Here we give a model theoretic semantics for optimization, which is a simple extension of the standard semantics, and a corresponding operational semantics, which may be efficiently implemented.
Efficient decomposition methods for the analysis of multi-facility blocking models
Authors: Conway Adrian E. , Pinsky Eugene , Tridandapani Srinivasan
Published: July 2002

Three new decomposition methods are developed for the exact analysis of stochastic multi-facility blocking models of the product-form type. The first is a basic decomposition algorithm that reduces the analysis of blocking probabilities to that of two separate subsystems. The second is a generalized M-subsystem decomposition method. The third is a more elaborate and efficient incremental decomposition technique. All of the algorithms exploit the sparsity of locality that can be found in the demand matrix of a system. By reducing the analysis to that of a set of subsystems, the overall dimensionality of the problem is diminished and the computational requirements are reduced significantly. This enables the efficient computation of blocking probabilities in large systems. Several numerical examples are provided to illustrate the computational savings that can be realized.
DIRECT: a query facility for multiple databases
Authors: Merz Ulla , King Roger
Published: July 2002

The subject of this research project is the architecture and design of a multidatabase query facility. These databases contain structured data, typical for business applications. Problems addressed are: presenting a uniform interface for retrieving data from multiple databases, providing autonomy for the component databases, and defining an architecture for semantic services.

DIRECT is a query facility for heterogeneous databases. The databases and their definitions can differ in their data models, names, types, and encoded values. Instead of creating a global schema, descriptions of different databases are allowed to coexist. A multidatabase query language provides a uniform interface for retrieving data from different databases. DIRECT has been exercised with operational databases that are part of an automated business system.
Quorum consensus in nested-transaction systems
Authors: Goldman Kenneth J. , Lynch Nancy
Published: July 2002

Gifford's Quorum Consensus algorithm for data replication is studied in the context of nested transactions and transaction failures (aborts), and a fully developed reconfiguration strategy is presented. A formal description of the algorithm is presented using the Input/Output automaton model for nested-transaction systems due to Lynch and Merritt. In this description, the algorithm itself is described in terms of nested transactions. The formal description is used to construct a complete proof of correctness that uses standard assertional techniques, is based on a natural correctness condition, and takes advantage of modularity that arises from describing the algorithm as nested transactions. The proof is accomplished hierarchically, showing that a fully replicated reconfigurable system “simulates” an intermediate replicated system, and that the intermediate system simulates an unreplicated system. The presentation and proof treat issues of data replication entirely separately from issues of concurrency control and recovery.
Finding a happy medium
Authors: Markus M. L.
Published: July 2002

The sometimes observed negative social effects of electronic communication technology are often attributed to the characteristics of the technology itself. Electronic mail, for instance, filters out personal and social cues and provides new capabilities not found in traditional media, and it has been argued that these factors have consequences such as “flaming” and depersonalization. Alternative theoretical perspectives on the impacts of information technology suggest that our ability to explain these outcomes might be enhanced by attending to users' intentional choices about how to use technology and to unpredictable technology usage patterns that emerge when users interact with the technology and each other. These alternative perspectives are examined in the context of an exploratory case study of a complex organization in which electronic mail was heavily used.

Users were found to select email deliberately when they wished to avoid unwanted social interactions. At the same time, they actively took steps to avoid negative outcomes, such as depersonalization of their relationships with subordinates. However, despite their well-intentioned efforts, some negative social effects did occur that cannot entirely be attributed to the technological characteristics of electronic communication. Instead, they appear to be ironic side effects of users' thoughtful efforts to use email effectively. These results suggest the value of according a prominent role in explanations of technology impacts to users' intended and unintended technology uses. The results also imply that negative social effects from using electronic communication technology may not prove easy to eradicate, despite technological developments such as multimedia integration, and despite efforts to train users in the best email “etiquette.”
Organization of clustered files for consecutive retrieval
Authors: Deogun J S. , Raghavan V V. , Tsou T K.W.
Published: July 2002

This paper studies the problem of storing single-level and multilevel clustered files. Necessary and sufficient conditions for a single-level clustered file to have the consecutive retrieval property (CRP) are developed. A linear time algorithm to test the CRP for a given clustered file and to identify the proper arrangement of objects, if CRP exists, is presented. For the single-level clustered files that do not have CRP, it is shown that the problem of identifying a storage organization with minimum redundancy is NP-complete.

Consequently, an efficient heuristic algorithm to generate a good storage organization for such files is developed. Furthermore, it is shown that, for certain types of multilevel clustered files, there exists a storage organization such that the objects in each cluster, for all clusters in each level of the clustering, appear in consecutive locations.
Algorithm 741: least-squares solution of a linear, bordered, block-diagonal system of equations
Authors: Ray Richard D.
Published: July 2002

A package of Fortran subroutines is presented for the least-squares solution of a system of overdetermined, full-rank, linear equations with single-bordered block-diagonal structure. This structure allows for a natural sequential processing, one block diagonal at a time, so that large systems can be handled even on smaller machines. Orthogonal transformations in the form of Householder reflections are used to factor the system. The routines make heavy use of the Levels 1, 2, and 3 BLAS.
CUTE
Authors: Bongartz I. , Conn A. R. , Gould Nick , Toint Ph. L.
Published: July 2002

The purpose of this article is to discuss the scope and functionality of a versatile environment for testing small- and large-scale nonlinear optimization algorithms. Although many of these facilities were originally produced by the authors in conjunction with the software package LANCELOT, we believe that they will be useful in their own right and should be available to researchers for their development of optimization software. The tools can be obtained by anonymous ftp from a number of sources and may, in many cases, be installed automatically. The scope of a major collection of test problems written in the standard input format (SIF) used by the LANCELOT software package is described. Recognizing that most software was not written with the SIF in mind, we provide tools to assist in building an interface between this input format and other optimization packages. These tools provide a link between the SIF and a number of existing packages, including MINOS and OSL. Additionally, as each problem includes a specific classification that is designed to be useful in identifying particular classes of problems, facilities are provided to build and manage a database of this information. There is a Unix and C shell bias to many of the descriptions in the article, since, for the sake of simplicity, we do not illustrate everything in its fullest generality. We trust that the majority of potential users are sufficiently familiar with Unix that these examples will not lead to undue confusion.