• Title/Summary/Keyword: exponential estimator

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The Comparative Study of NHPP Software Reliability Model Based on Exponential and Inverse Exponential Distribution (지수 및 역지수 분포를 이용한 NHPP 소프트웨어 무한고장 신뢰도 모형에 관한 비교연구)

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.2
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    • pp.133-140
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    • 2016
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, we were proposed the reliability model with the exponential and inverse exponential distribution, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, were employed. Analysis of failure, using real data set for the sake of proposing the exponential and inverse exponential distribution, was employed. This analysis of failure data compared with the exponential and inverse exponential distribution property. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the inverse exponential distribution model is also efficient in terms of reliability because it (the coefficient of determination is 80% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, the software developers have to consider life distribution by prior knowledge of the software to identify failure modes which can be able to help.

On the Bayesian Sequential Estiamtion Problem in k-Parameter Exponential Family

  • Yoon, Byoung-Chang;Kim, Jea-Joo
    • Journal of the Korean Statistical Society
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    • v.10
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    • pp.128-139
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    • 1981
  • The Bayesian sequential estimation problem for k parameters exponential families is considered using loss related to the Fisher information. Tractable expressions for the Bayes estimator and the posterior expected loss are found, and the myopic or one-step-ahead stopping rule is defined. Sufficient conditions are given for optimality of the myopic procedure, and the myopic procedure is shown to be asymptotically optimal in all cases considered.

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Accelerated Life Testings for System based on a Bivariate Exponential Model

  • Park, Byung-Gu;Yoon, Sang-Chul
    • Communications for Statistical Applications and Methods
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    • v.6 no.2
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    • pp.423-432
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    • 1999
  • Accelerated life testing of product is commonly used to reduced test time and costs. In this papers is considered when the product is a two component system with lifetimes following the bivariate exponential distribution of Sarkar(1987) using inverse power rule model. Also we derived the maximum likelihood estimators of parameters for asymptotic normality. We compare the mean square error of the proposed estimator for the life distribution under use conditions stree through Monte Carlo simulation.

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Exponential Lifetime Estimation with Unequal Interval Censoring (불균등 구간검사를 이용한 지수수명시간의 추정)

  • 이태섭;윤상운
    • Journal of Applied Reliability
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    • v.2 no.2
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    • pp.113-119
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    • 2002
  • The estimation of mean lifetimes in presence of interval censoring with replacement procedure are examined when the distributions of lifetimes are exponential. It is assumed that, due to physical restrictions and/or economic constraints, the number of failures is investigated only at several inspection times during the lifetime test. The maximum likelihood estimator is found in an implicit form. The Cramer-Rao lower bounds of the estimates are found in places of variances and by simulations the properties of the estimates are examined.

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Statistical Inferences for Bivariare Exponential Distribution in Reliability and Life Testing Problems

  • PARK, BYUNG-GU
    • Journal of Korean Society for Quality Management
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    • v.13 no.1
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    • pp.31-40
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    • 1985
  • In this paper, statistical estimation of the parameters of the bivariate exponential distribution are studied. Bayes estimators of the parameters are obtained and compared with the maximum likelihood estimators which are introduced by Freund. We know that the method of moments estimators coincide with the maximum likelihood estimators and Bayes estimators are more efficient than the maximum likelihood estimators in moderate samples. The asymptotic distributions of the maximum likelihood estimators and the estimator of mean time to system failure are obtained.

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Jackknife Estimation in a Truncated Exponential Distribution with an Uniform Outlier

  • Lee, Chang-Soo;Chang, Chu-Seock;Park, Yang-Woo
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.3
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    • pp.1021-1028
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    • 2006
  • We shall propose ML, ordinary jackknife and biased reducing estimators of the parameter in the right truncated exponential distribution with an unidentified uniform outlier when the truncated point is unknown and their biases and MSE's are compared numerically each other in the small sample sizes.

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Estimation of Freund model under censored data

  • Cho, Kil-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.403-409
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    • 2012
  • We consider a life testing experiment in which several two-component shared parallel systems are put on test, and the test is terminated at a predesigned experiment time. In this thesis, the maximum likelihood estimators for parameters of Freund's bivariate exponential distribution under the system level life testing are obtained. Results of comparative studies based on Monte Carlo simulation are presented.

Estimation for the Exponentiated Exponential Distribution Based on Multiply Type-II Censored Samples

  • Kang Suk-Bok;Park Sun-Mi
    • Communications for Statistical Applications and Methods
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    • v.12 no.3
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    • pp.643-652
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    • 2005
  • It has been known that the exponentiated exponential distribution can be used as a possible alternative to the gamma distribution or the Weibull distribution in many situations. But the maximum likelihood method does not admit explicit solutions when the sample is multiply censored. So we derive the approximate maximum likelihood estimators for the location and scale parameters in the exponentiated exponential distribution that are explicit function of order statistics. We also compare the proposed estimators in the sense of the mean squared error for various censored samples.

A Study on ENHPP Software Reliability Growth Model based on Exponentiated Exponential Coverage Function (지수화 지수 커버리지 함수를 고려한 ENHPP 소프트웨어 신뢰성장 모형에 관한 연구)

  • Kim, Hee-Cheul
    • The Journal of Information Technology
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    • v.10 no.2
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    • pp.47-64
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    • 2007
  • Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times, and estimation of the reliability and availability of a software product require quantification of a critical element of the software testing process : test coverage. This model called enhanced non-homogeneous poission process(ENHPP). In this paper, exponential coverage and S-coverage model was reviewed, proposes the exponentiated exponential coverage reliability model, which maked out efficiency substituted for gamma and Weibull model(2 parameter shape illustrated by Gupta and Kundu(2001). In this analysis of software failure data, algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics for the sake of efficient model, was employed.

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Inference of the Exponential Distribution Based on Multiply Type-II Censored Samples

  • Kang, Suk-Bok;Lee, Sang-Ki
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.04a
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    • pp.279-293
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    • 2006
  • In this paper, we derive the approximate maximum likelihood estimators of the scale parameter and location parameter of the exponential distribution based on multiply Type-II censored samples. Then three type tests, including the modified Clamor-von Mises test, the modified Watson test and the modified Kolmogorov-Smirnov test are developed for the exponential distribution based on multiply Type-II censored samples by using the proposed estimators. For each test, Monte Carlo techniques are used to generate critical values. The powers of these tests are investigated under several alternative distributions.

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