염봉진 교수

Optimal accelerated degradation test (ADT) plans are developed assuming that the constant-stress loading method is employed and the degradation characteristic follows a Wiener process. Unlike the previous works on planning ADTs based on stochastic process models, this article determines the test stress levels and the proportion of test units allocated to each stress level such that the asymptotic variance of the maximum-likelihood estimator of the qth quantile of the lifetime distribution at the

Abstract This paper contains a bibliography of approximately 530 journal papers and books on process capability indices for the period 2000–2009. The related literature is classified into four major categories, namely, books, review/overview papers, theory‐ and method‐related papers, and special applications. Theory‐ and method‐related papers are further classified into univariate and multivariate cases, and special applications include acceptance sampling plans, supplier selection, and toleranc

Statistically optimal and compromise step-stress accelerated degradation test (ADT) plans are developed under the assumption that the degradation characteristic follows a Wiener process. Compromise plans are provided for the case where the experimenter wants to check the validity of the assumed stress-parameter relationship. Two and three step-stress levels are respectively considered in the statistically optimal and compromise ADT plans. For both types of plans, step-stress level(s) and stress

For the case where the lifetime at a stress level has a Weibull distribution, statistically optimal and practical accelerated life test plans are developed under the assumptions of intermittent inspection and Type-I censoring. For a statistically optimal plan the low stress level, the proportion of test units allocated, and the inspection times are determined such that the asymptotic variance of the maximum-likelihood estimator of a certain quantile at the use condition is minimized. Although th

For the exponentially distributed lifetimes, optimal accelerated life test plans are determined under the assumptions of periodic inspection and Type I censoring. Computational results indicate that for the range of parameter values considered the asymptotic variance of the estimated mean or pth quantile at the use stress is not sensitive to the number of inspections at overstress levels. Senstivity analyses are also conducted to see how senstive the asymptotic variance of the estimated mean is

Type-I censored reliability acceptance sampling plans (RASPs) are developed for the Weibull lifetime distribution with unknown shape and scale parameters such that the producer and consumer risks are satisfied. It is assumed that the life test is conducted at an accelerated condition for which the acceleration factor (AF) is known, and each item is continuously monitored for failure. Sensitivity analyses are also conducted to assess the effect of the uncertainty in the assumed AF on the actual p

Abstract This paper presents a procedure for developing life-test sampling plans for exponential distributions based upon accelerated life testing(ALT). Type II censoring is assumed at each overstress level. The derived test statistic is shown to be a quotient of two independent random variables, each of which is a rational power of a Chi-square random variable. The distribution of the test statistic is characterized by the H-function, which can be numerically evaluated to obtain desired samplin

Abstract The Taguchi idea of parameter design has received considerable attention from statisticians and engineers. However, it is only recently that some of the underlying principles of his ideas have been clarified and other alternative procedures have been proposed. This paper reviews the currently available procedures for parameter design in terms of minimizing expected loss. Advantages and disadvantages of each procedure are discussed for the three types of performance characteristics, and

Abstract This is the author's second bibliography on process capability indices (PCIs) and contains approximately 1080 journal papers and books for the period 2010–2021. The related literature is classified into six major categories, namely, books, review/overview papers, theory‐ and method‐related papers, special applications, software packages, and papers omitted in the author's previous bibliography. Theory‐ and method‐related papers are further classified into univariate, multivariate, and f