• 제목/요약/키워드: Censored Data

검색결과 405건 처리시간 0.028초

Inference Based on Generalized Doubly Type-II Hybrid Censored Sample from a Half Logistic Distribution

  • Lee, Kyeong-Jun;Park, Chan-Keun;Cho, Young-Seuk
    • Communications for Statistical Applications and Methods
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    • 제18권5호
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    • pp.645-655
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    • 2011
  • Chandrasekar et al. (2004) introduced a generalized Type-II hybrid censoring. In this paper, we propose generalized doubly Type-II hybrid censoring. In addition, this paper presents the statistical inference on the scale parameter for the half logistic distribution when samples are generalized doubly Type-II hybrid censoring. The approximate maximum likelihood(AMLE) method is developed to estimate the unknown parameter. The scale parameter is estimated by the AMLE method using two di erent Taylor series expansion types. We compar the AMLEs in the sense of the mean square error(MSE). The simulation procedure is repeated 10,000 times for the sample size n = 20; 30; 40 and various censored samples. The $AMLE_I$ is better than $AMLE_{II}$ in the sense of the MSE.

The skew-t censored regression model: parameter estimation via an EM-type algorithm

  • Lachos, Victor H.;Bazan, Jorge L.;Castro, Luis M.;Park, Jiwon
    • Communications for Statistical Applications and Methods
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    • 제29권3호
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    • pp.333-351
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    • 2022
  • The skew-t distribution is an attractive family of asymmetrical heavy-tailed densities that includes the normal, skew-normal and Student's-t distributions as special cases. In this work, we propose an EM-type algorithm for computing the maximum likelihood estimates for skew-t linear regression models with censored response. In contrast with previous proposals, this algorithm uses analytical expressions at the E-step, as opposed to Monte Carlo simulations. These expressions rely on formulas for the mean and variance of a truncated skew-t distribution, and can be computed using the R library MomTrunc. The standard errors, the prediction of unobserved values of the response and the log-likelihood function are obtained as a by-product. The proposed methodology is illustrated through the analyses of simulated and a real data application on Letter-Name Fluency test in Peruvian students.

Reliability for Series and Parallel Systems in Bivariate Pareto Model : Random Censorship Case

  • Cho, Jang-Sik;Cho, Kil-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제14권3호
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    • pp.461-469
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    • 2003
  • In this paper, we consider the series and parallel system which include two components. We assume that the lifetimes of two components follow the bivariate Pareto model with random censored data. We obtain the estimators and approximated confidence intervals of the reliabilities for series and parallel systems based on maximum likelihood estimator and the relative frequency, respectively. Also we present a numerical example by giving a data set which is generated by computer.

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임의절단 자료에서의 Pr[X>Y]의 비모수적 추정 (Nonparametric Estimation of Pr[X>Y] from Random Censored Data)

  • 정해성;김재주
    • 품질경영학회지
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    • 제23권2호
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    • pp.91-102
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    • 1995
  • For two independent random variables X and Y, the functional R=Pr[X>Y] is of practical importance in reliability. X can be interpreted as the strength of a component subjected to a stress Y, and R is the component's reliability. In this paper nonparametric approach to estimation of R based on censored observations in the strength variables is analyzed and compared by simulations in the moderate sample sizes.

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Estimation for the scale parameter of Weibull Distribution Based on Multiply Censored Samples

  • 한준태;강석복;이화정
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2004년도 춘계학술대회
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    • pp.83-90
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    • 2004
  • We consider the problem of estimating the scale parameter of the Weibull distribution based on multiply Type-II censord samples. We propose some estimators by using the approximate maximum likelihood estimation method. The proposed estimators are compared in the sense of the mean squared error.

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Optimal three step-stress accelerated life tests for Type-I hybrid censored data

  • Moon, Gyoung Ae
    • Journal of the Korean Data and Information Science Society
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    • 제26권1호
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    • pp.271-280
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    • 2015
  • In this paper, the maximum likelihood estimators for parameters are derived under three step-stress accelerated life tests for Type-I hybrid censored data. The exponential distribution and the cumulative exposure model are considered based on the assumption that a log quadratic relationship exits between stress and the mean lifetime ${\theta}$. The test plan to search optimal stress change times minimizing the asymptotic variance of maximum likelihood estimators are presented. A numerical example to illustrate the proposed inferential procedures and some simulation results to investigate the sensitivity of the optimal stress change times by the guessed parameters are given.

Empirical Bayes Interval Estimation by a Sample Reuse Method

  • Cho, Kil-Ho;Choi, Dal-Woo;Chae, Hyeon-Sook
    • Journal of the Korean Data and Information Science Society
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    • 제8권1호
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    • pp.41-48
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    • 1997
  • We construct the empirical Bayes(EB) confidence intervals that attain a specified level of EB coverage for the unknown scale parameter in the Weibull distribution with the known shape parameter under the type II censored data. Our general approach is to use an EB bootstrap samples introduced by Larid and Louis(1987). Also, we compare the coverage probability and the expected interval length for these bootstrap intervals with those of the naive intervals through Monte Carlo simulation.

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Bayesian estimations on the exponentiated half triangle distribution under Type-I hybrid censoring

  • Kim, Yong-Ku;Kang, Suk-Bok;Seo, Jung-In
    • Journal of the Korean Data and Information Science Society
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    • 제22권3호
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    • pp.565-574
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    • 2011
  • The exponenetiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of shape parameter and reliability function in the exponenetiated half triangle distribution based on Type-I hybrid censored data. Here we consider conjugate prior and noninformative prior and obtained corresponding posterior distributions. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.

The Bivariate Kumaraswamy Weibull regression model: a complete classical and Bayesian analysis

  • Fachini-Gomes, Juliana B.;Ortega, Edwin M.M.;Cordeiro, Gauss M.;Suzuki, Adriano K.
    • Communications for Statistical Applications and Methods
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    • 제25권5호
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    • pp.523-544
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    • 2018
  • Bivariate distributions play a fundamental role in survival and reliability studies. We consider a regression model for bivariate survival times under right-censored based on the bivariate Kumaraswamy Weibull (Cordeiro et al., Journal of the Franklin Institute, 347, 1399-1429, 2010) distribution to model the dependence of bivariate survival data. We describe some structural properties of the marginal distributions. The method of maximum likelihood and a Bayesian procedure are adopted to estimate the model parameters. We use diagnostic measures based on the local influence and Bayesian case influence diagnostics to detect influential observations in the new model. We also show that the estimates in the bivariate Kumaraswamy Weibull regression model are robust to deal with the presence of outliers in the data. In addition, we use some measures of goodness-of-fit to evaluate the bivariate Kumaraswamy Weibull regression model. The methodology is illustrated by means of a real lifetime data set for kidney patients.

Independent Testing in Marshall and Olkin's Bivariate Exponential Model Using Fractional Bayes Factor Under Bivariate Type I Censorship

  • Cho, Kil-Ho;Cho, Jang-Sik;Choi, Seung-Bae
    • Journal of the Korean Data and Information Science Society
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    • 제19권4호
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    • pp.1391-1396
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    • 2008
  • In this paper, we consider two components system which the lifetimes have Marshall and Olkin's bivariate exponential model with bivariate type I censored data. We propose a Bayesian independent test procedure for above model using fractional Bayes factor method by O'Hagan based on improper prior distributions. And we compute the fractional Bayes factor and the posterior probabilities for the hypotheses, respectively. Also we select a hypothesis which has the largest posterior probability. Finally a numerical example is given to illustrate our Bayesian testing procedure.

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