Showing papers on "Reliability (statistics) published in 1989"
TL;DR: Comparison studies are needed of the validity, reliability, and responsiveness of generic and disease-specific measures in the same population and in minority and age-specific groups.
Abstract: Application of generic and specific measures of health status and quality of life to different diseases, conditions, states, and populations is increasing. Four strategies for using these measures are separate generic and specific measures, modified generic measures, disease-specific supplements, and batteries. The preferred strategy depends on project aims, methodological concerns, and practical constraints. Generic measures are necessary to compare outcomes across different populations and interventions, particularly for cost-effectiveness studies. Disease-specific measures assess the special states and concerns of diagnostic groups. Specific measures may be more sensitive for the detection and quantification of small changes that are important to clinicians or patients. Comparison studies are needed of the validity, reliability, and responsiveness of generic and disease-specific measures in the same population and in minority and age-specific groups.
1,735 citations
TL;DR: In contrast, little attention has been given to the quality of nominal sca... as mentioned in this paper, while most research related to the reliability and validity of marketing measures has focused on multi-item quantitative scales.
Abstract: Most research related to the reliability and validity of marketing measures has focused on multi-item quantitative scales. In contrast, little attention has been given to the quality of nominal sca...
1,415 citations
TL;DR: The IEEE Reliability Test System (RTS) has proved to be extremely valuable in highlighting and comparing the capabilities (or incapabilities) of programs used in reliability studies, the differences in the perception of various power utilities and the Differences in the solution techniques.
Abstract: The IEEE Subcommittee on the Application of Probability Methods (APM) published the IEEE Reliability Test System (RTS) [1] in 1979. This system provides a consistent and generally acceptable set of data that can be used both in generation capacity and in composite system reliability evaluation [2,3]. The test system provides a basis for the comparison of results obtained by different people using different methods. Prior to its publication, there was no general agreement on either the system or the data that should be used to demonstrate or test various techniques developed to conduct reliability studies. Development of reliability assessment techniques and programs are very dependent on the intent behind the development as the experience of one power utility with their system may be quite different from that of another utility. The development and the utilization of a reliability program are, therefore, greatly influenced by the experience of a utlity and the intent of the system manager, planner and designer conducting the reliability studies. The IEEE-RTS has proved to be extremely valuable in highlighting and comparing the capabilities (or incapabilities) of programs used in reliability studies, the differences in the perception of various power utilities and the differences in the solution techniques. The IEEE-RTS contains a reasonably large power network which can be difficult to use for initial studies in an educational environment.
727 citations
Journal Article•
TL;DR: This paper reviews initial and more recently published studies assessing the psychometric properties of the PBI, and which suggest satisfactory reliability and validity.
Abstract: The Parental Bonding Instrument (PBI) was designed as a refined self-report measure of fundamental parental dimensions of care and protection. The utility of such a self-report measure is dependent on demonstration of robust psychometric characteristics, particularly the extent to which the PBI provides valid ratings of actual and not merely perceived characteristics. This paper reviews initial and more recently published studies assessing the psychometric properties of the PBI, and which suggest satisfactory reliability and validity.
405 citations
TL;DR: In this article, the authors show that the discovery of the role of intentions depends on the statistical power of test procedures, the reliability of measures of intentions, and the nature of the processes intervening between intentions and behavior.
380 citations
344 citations
TL;DR: This book discusses the development of Reliability Standards and Specifications, as well as techniques of Estimating Reliability at Design Stage, and the role of management in Reliability.
Abstract: Introduction, Definitions, and Relationships. The Role of Management in Reliability. Managing Reliability as a Process. Economics of Reliability. Design for Reliability. Failure Modes and Effects (FMEA) and Fault-Tree Analysis (FTA) (Success-Tree Analysis--STA). Reliability Specification and Goal Setting. Concurrent Engineering. Human-Centered Design. Reliability Information Collection and Analysis. Designing Experiments to Measure and Improve Reliability. Accelerated Testing. Failure Analysis System--Root Cause and Corrective Action. Physics of Failure. Maintainability and Reliability. Component Reliability. Thermal Management and Reliability of Electronics. Mechanical Stress and Analysis. Mechanical Reliability. Design for Mechanical Reliability. System Reliability. Software Reliability and the Development Process. Supplier Reliability and Quality Assurance. Techniques of Estimating Reliability at Design Stage. Mathematical and Statistical Methods and Models in Reliability and Life Studies. Life Distributions and Concepts. Graphical Analyses of Reliability Data. Appendices: A: Tables and Charts. B: Charts. C: Reliability Standards and Specifications.
254 citations
Book•
01 Jan 1989
TL;DR: In this article, the authors present a utility perspective on industrial power generation economics, including load forecasting, capacity resource planning, and power system reliability analysis, as well as economic and regulatory analysis.
Abstract: The Utility Perspective. Introduction to Utility Financial Accounting. Time Value of Money. Economic Evaluation. Financial and Regulatory Analysis. Industrial Power Generation Economics. Electricity Load--Demand Forecasting. Load Forecasting II. Power Plant Reliability Characteristics. Generation System Reliability. Generation System Reliability II. Production Simulation. Production Simulation II. Generation Planning. Capacity Resource Planning. Bulk Power Transmission Planning. Power System Stability. Preparing for the Next Century. Index.
217 citations
TL;DR: In this paper, the parametric sensitivity of the most likely failure point is studied and a formula is derived for the derivative of the unit normal vector to the failure surface in this point.
Abstract: New insight into parametric sensitivity in first-order reliability theory is given by studying the parametric sensitivity of the most likely failure point. A formula is derived for the derivative of the unit normal vector to the failure surface in this point. The derivative of the first-order reliability index is also a result of the analysis, and a geometrical interpretation of this result is given. The derivatives find applications, e.g., within structural systems reliability and sensitivity analysis.
187 citations
TL;DR: In this article, a new reliability index based on the concepts from Bayesian statistical decision theory is introduced, which provides a rational basis for the assessment of structural safety and for development of reliability-based codes under arbitrary states of knowledge.
Abstract: In assessing structural safety, the state of knowledge is imperfect when uncertainties arise from estimation error or model imperfection. The nature of these uncertainties is fundamentally different from those arising from inherent variabilities. A reliability index under such conditions is a point estimator of safety. Motivated by needs in structural code development, a set of fundamental requirements on the point-estimator reliability index are formulated. Existing definitions of the reliability index are examined in this light and are found to be deficient in satisfying one or more of the requirements. Based on the concepts from Bayesian statistical decision theory, a new reliability index is introduced which satisfies all the stipulated requirements. The index recognizes the fundamental difference between the sources of uncertainty and provides a rational basis for the assessment of structural safety and for development of reliability-based codes under arbitrary states of knowledge. Methods are also developed for quantifying the uncertainty in the measure of safety arising from the imperfect state of knowledge. Existing reliability methods can be used to compute the probability distribution or variance of the safety measure. A simple example illustrates the main concepts of the paper.
173 citations
TL;DR: In this paper, the results obtained from two surveys dealing with US and Canadian utility activities are discussed, focusing on service continuity data collection and utilization, and service continuity statistics are summarized for those Canadian utilities that participate in the Canadian Electrical Association annual service continuity reports.
Abstract: Distribution system reliability assessment is discussed. The assessment consists of measuring past performance and predicting future performance. The results obtained from two surveys dealing with US and Canadian utility activities are discussed, focusing on service continuity data collection and utilization. Service continuity statistics are summarized for those Canadian utilities that participate in the Canadian Electrical Association annual service continuity reports. >
Journal Article•
TL;DR: It is shown that the objective function of a least squares type nonlinear parameter estimation problem can be any non- negative real function, and therefore this class of problems corre- sponds to global optimization.
Abstract: In this paper we first show that the objective function of a least squares type nonlinear parameter estimation problem can be any non- negative real function, and therefore this class of problems corre- sponds to global optimization. Two non-derivative implementations of a global optimization method are presented; with nine standard test functions applied to measure their efficiency. A new nonlinear test problem is then presented for testing the reliability of global op- timization algorithms. This test function has a countable infinity of local minima and only one global minimizer. The region of attraction of the global minimum is of zero measure. The results of efficiency and reliability tests are given.
TL;DR: In this article, a procedure adapted from Churchill's (1979) paradigm for developing better measures of marketing constructs, that may be useful in constructing manipulations of advertising (message) involvement, is discussed.
Abstract: Given the influential role involvement plays in advertising processing, it is important that researchers planning to manipulate the construct take great care in developing their manipulations and manipulation checks. This study discusses a procedure, adapted from Churchill's (1979) paradigm for developing better measures of marketing constructs, that may be useful in constructing manipulations of advertising (message) involvement. A manipulation and accompanying manipulation checks are offered as examples of instructions/items satisfactorily meeting reliability and validity requirements. The study draws attention to the importance of developing valid manipulations of involvement when conducting advertising research.
20 Sep 1989
TL;DR: Definitions of software reliability are presented, and an overview of reliability is given, and the system-software-availability relationship is explored.
Abstract: Definitions of software reliability are presented, and an overview of reliability is given. The system-software-availability relationship is also explored. >
01 Mar 1989
TL;DR: In this article, the authors describe the reliability modeling techniques that are in extensive applications during recent years in evaluating the reliability of the systems, and describe how these techniques are used in planning, design and operation.
Abstract: Quantitative reliability techniques are being increasingly used in system planning, design and operation. These methods call for the development of a suitable model. The fundamental parameters in building the model are the individual units/components and their failure and /or repair statistics. With complex unit configurations the system model complexity increases considerably, and hence high speed digital computers are inevitably used to solve them.
This paper describes the reliability modeling techniques that are in extensive applications during recent years in evaluating the reliability of the systems.
TL;DR: Questions of measurement validity need continuing attention and more attention should be paid to validating uses of utility assessments: Can utility assessments distinguish prospectively, among patients who subsequently experience the same health outcome, those for whom it is associated with a high or low level of well-being?
Abstract: Each of the elements of a utility assessment strategy—defining and describing health states of interest, identifying subjects, choosing a scaling task, aggregating across subjects, determining reliability and validity—is controversial. The controversy is in part explained by the interdisciplinary na
TL;DR: In this paper, the authors deal with reliability and fault-tolerant properties of networks, in particular those concerning diameter vulnerability, and study in details reliability properties of some families of networks in particular de Bruijn and Kautz networks.
Abstract: This paper deals with reliability and fault-tolerant properties of networks. We first survey general reliability properties of networks, in particular those concerning diameter vulnerability. Then we study in details reliability properties of some families of networks in particular de Bruijn and Kautz networks and their generalizations which appear as very good fault-tolerant networks.
TL;DR: This paper studies the problem of interactive searching in a set of numbers using comparison queries, under the assumption that each answer can be erroneous with a constant probability p and that a given reliability 0 2/3, O(logn) algorithms are given in each version of search.
TL;DR: Several quantitative tests and measures used to evaluate range of motion, edema, muscle performance, sensation, dexterity, and physical capacity are reviewed, demonstrating the continued need for support for the validity and reliability of hand-assessment instrumentation.
Abstract: Evaluation of hand function is a qualitative and quantitative process. This article provides a review of several quantitative tests and measures used to evaluate range of motion, edema, muscle performance, sensation, dexterity, and physical capacity. The validity and reliability of these instruments are emphasized. Some of the hand assessments reviewed are in the early developmental phase with further refinements yet to come. This article demonstrates the continued need to provide support for the validity and reliability of hand-assessment instrumentation. Regardless of the statistical support provided, however, the authors believe that hand therapy will remain an art as well as a science.
IBM1
TL;DR: The results show that exponential-type soft- ware reliability growth models that deal with error- counting data could be used even if the perfect debugging assumption were not held, in which case the interpretation of the model parameters should be changed.
Abstract: This paper discusses the improvement of conventional software reliability growth models by elimination of the unreasonable assumption that errors or faults in a program can be perfectly removed when they are detected. The results show that exponential-type soft- ware reliability growth models that deal with error- counting data could be used even if the perfect debugging assumption were not held, in which case the interpretation of the model parameters should be changed. An analysis of real project data is presented.
01 Jan 1989
Book•
31 Aug 1989
TL;DR: This book contains 38 papers presented at the seventh Working Conference on 'Reliability and Optimization of Structural Systems' held at Boulder, Colorado, USA, on April 2-4, 1996.
Abstract: Reliability and Optimization of Structural Systems 1st ... This book contains 38 papers presented at the seventh Working Conference on 'Reliability and Optimization of Structural Systems' held at Boulder, Colorado, USA, on April 2-4, 1996. The Working Conference was organized by the IFIP (International Federation for Information Processing) Working Group 7.5 of Technical Committee 7 and was the seventh in a series of similar conferences.
TL;DR: In this article, the reliability of TTI under variable temperature conditions was systematically studied, and three major types of commercial TTI were studied and it was shown that, although some types exhibit a significant history effect, the prediction models can be applied satisfactorily for the variable temperature storage.
Abstract: Application of time temperature indicators (TTI) is based on response information or kinetic models from isothermal testing. The reliability of such models under variable temperature conditions was systematically studied. Nonisothermal experiments of two types were conducted involving prolonged exposures to high temperatures followed by storage at low temperatures to study the “history effect,” and storage at controlled, sinusoidaly varying temperatures. Three major types of commercial TTI were studied. Results showed that, although some types of TTI exhibit a significant “history effect,” the prediction models can be applied satisfactorily for the variable temperature storage.
TL;DR: In this paper, a reliability investigation was initiated for a fleet of diesel operated loadhaul-dump (LHD) machines in a Swedish mine and failure data for one year of LHD machines were analyzed using the recently developed graphical technique of total time on test (TTT) plotting.
TL;DR: The reliabilities of the Procrastination Assessment Scale (PA) and the general PA scale were examined in this paper, with a focus on split-half comparisons (odd vs even items) from two secti...
Abstract: The reliabilities of the Procrastination Assessment Scale—Students and the General Procrastination Scale were examined. Scores (n = 116) on split-half comparisons (odd vs even items) from two secti...
TL;DR: It was found that most of the components of the Halstead-Reitan battery had psychometrically satisfactory relative reliability levels, however, schizophrenics exhibited significantly lower levels of reliability than did the other subgroups.
Abstract: Data are presented concerning the test-retest reliability of the Halstead-Reitan battery and the WAIS in a heterogeneous neuropsychiatric sample of 150 patients. Relative reliability or stability of results was evaluated through use of Pearson r correlation coefficients, while absolute reliability, or sensitivity to change in clinical condition, was evaluated with paired sample t tests. Subgroups of alcoholic/trauma, schizophrenic, and vascular disease patients were extracted from the total sample in order to examine for the possibility of different reliability levels among different clinical groups. It was found that most of the components of the Halstead-Reitan battery had psychometrically satisfactory relative reliability levels. However, schizophrenics exhibited significantly lower levels of reliability than did the other subgroups. Differences in absolute reliability were characterized by a greater incidence of improved performance on second testing in the alcoholic/trauma subgroup than in t...
TL;DR: A recurring dilemma for readers of physical therapy journals is that authors and editors have frequently contributed to publications that have not differentiated clearly between consistency and the ability to differentiate among subjects—both known as reliability.
Abstract: To the Editor: Because reliability is a prerequisite for validity, it is of interest to physical therapists. But what is reliability? Mitchell states, “A reliable instrument is one with small errors of measurement, one that shows stability, consistency, and dependability of scores for individuals on the trait, characteristic or behavior being assessed.”1(p377) This view is concordant wih the opinion offered by Rothstein: “Reliability is basically the consistency of a measurement.”2(p5) There is, however, a second definition of reliability, that offered by classical test theory, that is somewhat different from the statements expressed above. This theory depicts reliability as being a ratio of variances; specifically, it is the variance attributed to differences among subjects divided by the total variance.3
A recurring dilemma for readers of physical therapy journals is that authors and editors have frequently contributed to publications that have not differentiated clearly between consistency and the ability to differentiate among subjects—both known as reliability.…
TL;DR: A general mathematical model for a network design problem with reliability constraints and a revised formulation which seems particularly appropriate for fiber-optics networks is presented, and upper and lower bounding procedures based on continuous relaxations of this modified formulation are described.
Abstract: A general mathematical model for a network design problem with reliability constraints and a revised formulation which seems particularly appropriate for fiber-optics networks is presented. Upper and lower bounding procedures based on continuous relaxations of this modified formulation are described. Preliminary computational results are reported. Limited computational results indicate a good performance of the algorithm, producing a gap between lower and upper bounds that is sufficiently small for a branch-and-bound procedure to be applicable. >
TL;DR: In this paper, an instrument (Benchmarks) has been designed to aid managers in assessing their strengths and weaknesses, which allows for a separate assessment of managerial failures and allows for identifying managerial flaws.