• 제목/요약/키워드: credible interval

검색결과 27건 처리시간 0.028초

Bayesian Model Selection in the Unbalanced Random Effect Model

  • Kim, Dal-Ho;Kang, Sang-Gil;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제15권4호
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    • pp.743-752
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    • 2004
  • In this paper, we develop the Bayesian model selection procedure using the reference prior for comparing two nested model such as the independent and intraclass models using the distance or divergence between the two as the basis of comparison. A suitable criterion for this is the power divergence measure as introduced by Cressie and Read(1984). Such a measure includes the Kullback -Liebler divergence measures and the Hellinger divergence measure as special cases. For this problem, the power divergence measure turns out to be a function solely of $\rho$, the intraclass correlation coefficient. Also, this function is convex, and the minimum is attained at $\rho=0$. We use reference prior for $\rho$. Due to the duality between hypothesis tests and set estimation, the hypothesis testing problem can also be solved by solving a corresponding set estimation problem. The present paper develops Bayesian method based on the Kullback-Liebler and Hellinger divergence measures, rejecting $H_0:\rho=0$ when the specified divergence measure exceeds some number d. This number d is so chosen that the resulting credible interval for the divergence measure has specified coverage probability $1-{\alpha}$. The length of such an interval is compared with the equal two-tailed credible interval and the HPD credible interval for $\rho$ with the same coverage probability which can also be inverted into acceptance regions of $H_0:\rho=0$. Example is considered where the HPD interval based on the one-at- a-time reference prior turns out to be the shortest credible interval having the same coverage probability.

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Estimation of the exponentiated half-logistic distribution based on multiply Type-I hybrid censoring

  • Jeon, Young Eun;Kang, Suk-Bok
    • Communications for Statistical Applications and Methods
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    • 제27권1호
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    • pp.47-64
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    • 2020
  • In this paper, we derive some estimators of the scale parameter of the exponentiated half-logistic distribution based on the multiply Type-I hybrid censoring scheme. We assume that the shape parameter λ is known. We obtain the maximum likelihood estimator of the scale parameter σ. The scale parameter is estimated by approximating the given likelihood function using two different Taylor series expansions since the likelihood equation is not explicitly solved. We also obtain Bayes estimators using prior distribution. To obtain the Bayes estimators, we use the squared error loss function and general entropy loss function (shape parameter q = -0.5, 1.0). We also derive interval estimation such as the asymptotic confidence interval, the credible interval, and the highest posterior density interval. Finally, we compare the proposed estimators in the sense of the mean squared error through Monte Carlo simulation. The average length of 95% intervals and the corresponding coverage probability are also obtained.

신뢰구간상에서 EVMS 성과지수모델의 검정에 관한 연구 (A Study for Verification of the Performance Index Model of EVMS in Credible Interval)

  • 강병욱;이영대;박혁;천용현
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2002년도 학술대회지
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    • pp.478-481
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    • 2002
  • 현재 국내 건설프로젝트에 EVMS가 도입되어 비용과 공정을 효과적으로 통합하여 관리하고 있으나 EVMS는 선진 외국의 건설환경에 적합한 방법으로서 이 EVMS를 국내에 적용하는 데에는 다소 어려운 점이 발견되고 있다. 본 논문에서는 EVMS에서 최종공사비(EAC)를 예측하는데 사용되고 있는 지수중의 하나인 합성지수(CI)의 가중치 n, m에 대한 통계적 분석을 통하여 신뢰구간상에 나타나는 합성지수(CI)를 검정하여 최종공사비(EAC)를 예측하는데 효과적으로 사용하고자 한다.

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Development of Matching Priors for P(X < Y) in Exprnential dlstributions

  • Lee, Gunhee
    • Journal of the Korean Statistical Society
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    • 제27권4호
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    • pp.421-433
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    • 1998
  • In this paper, matching priors for P(X < Y) are investigated when both distributions are exponential distributions. Two recent approaches for finding noninformative priors are introduced. The first one is the verger and Bernardo's forward and backward reference priors that maximizes the expected Kullback-Liebler Divergence between posterior and prior density. The second one is the matching prior identified by matching the one sided posterior credible interval with the frequentist's desired confidence level. The general forms of the second- order matching prior are presented so that the one sided posterior credible intervals agree with the frequentist's desired confidence levels up to O(n$^{-1}$ ). The frequentist coverage probabilities of confidence sets based on several noninformative priors are compared for small sample sizes via the Monte-Carlo simulation.

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Bayesian analysis of an exponentiated half-logistic distribution under progressively type-II censoring

  • Kang, Suk Bok;Seo, Jung In;Kim, Yongku
    • Journal of the Korean Data and Information Science Society
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    • 제24권6호
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    • pp.1455-1464
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    • 2013
  • This paper develops maximum likelihood estimators (MLEs) of unknown parameters in an exponentiated half-logistic distribution based on a progressively type-II censored sample. We obtain approximate confidence intervals for the MLEs by using asymptotic variance and covariance matrices. Using importance sampling, we obtain Bayes estimators and corresponding credible intervals with the highest posterior density and Bayes predictive intervals for unknown parameters based on progressively type-II censored data from an exponentiated half logistic distribution. For illustration purposes, we examine the validity of the proposed estimation method by using real and simulated data.

Bayesian Analysis for Burr-Type X Strength-Stress Model

  • Kang, Sang-Gil;Ko, Jeong-Hwan;Lee, Woo-Dong
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 1999년도 춘계학술대회 발표논문집
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    • pp.191-197
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    • 1999
  • In this paper, we develop noninformative priors that are used for estimating the reliability of stress-strength system under the Burr-type X distribution. A class of priors is found by matching the coverage probabilities of one-sided Bayesian credible interval with the corresponding frequentist coverage probabilities. It turns out that the reference prior is a first order matching prior. The propriety of posterior under matching prior is provided. The frequentist coverage probabilities are given for small samples.

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On Estimating Burr Type XII Parameter Based on General Type II Progressive Censoring

  • Kim Chan-Soo
    • Communications for Statistical Applications and Methods
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    • 제13권1호
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    • pp.89-99
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    • 2006
  • This article deals with the problem of estimating parameters of Burr Type XII distribution, on the basis of a general progressive Type II censored sample using Bayesian viewpoints. The maximum likelihood estimator does not admit closed form but explicit sharp lower and upper bounds are provided. Assuming squared error loss and linex loss functions, Bayes estimators of the parameter k, the reliability function, and the failure rate function are obtained in closed form. Finally, a simulation study is also included.

Multinomial Group Testing with Small-Sized Pools and Application to California HIV Data: Bayesian and Bootstrap Approaches

  • 김종민;허태영;안형진
    • 한국조사연구학회:학술대회논문집
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    • 한국조사연구학회 2006년도 춘계학술대회 발표논문집
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    • pp.131-159
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    • 2006
  • This paper consider multinomial group testing which is concerned with classification each of N given units into one of k disjoint categories. In this paper, we propose exact Bayesian, approximate Bayesian, bootstrap methods for estimating individual category proportions using the multinomial group testing model proposed by Bar-Lev et al (2005). By the comparison of Mcan Squre Error (MSE), it is shown that the exact Bayesian method has a bettor efficiency and consistency than maximum likelihood method. We suggest an approximate Bayesian approach using Markov Chain Monte Carlo (MCMC) for posterior computation. We derive exact credible intervals based on the exact Bayesian estimators and present confidence intervals using the bootstrap and MCMC. These intervals arc shown to often have better coverage properties and similar mean lengths to maximum likelihood method already available. Furthermore the proposed models are illustrated using data from a HIV blooding test study throughout California, 2000.

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Noninformative Priors for Stress-Strength System in the Burr-Type X Model

  • Kim, Dal-Ho;Kang, Sang-Gil;Cho, Jang-Sik
    • Journal of the Korean Statistical Society
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    • 제29권1호
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    • pp.17-27
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    • 2000
  • In this paper, we develop noninformative priors that are used for estimating the reliability of stress-strength system under the Burr-type X model. A class of priors is found by matching the coverage probabilities of one-sided Bayesian credible interval with the corresponding frequentist coverage probabilities. It turns out that the reference prior as well as the Jeffreys prior are the second order matching prior. The propriety of posterior under the noninformative priors is proved. The frequentist coverage probabilities are investigated for samll samples via simulation study.

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Noninformative Priors in Freund's Bivariate Exponential Distribution : Symmetry Case

  • 조장식;백승욱;김희재
    • Journal of the Korean Data and Information Science Society
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    • 제13권2호
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    • pp.235-242
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    • 2002
  • In this paper, we develop noninformative priors that are used for estimating the ratio of failure rates under Freund's bivariate exponential distribution. A class of priors is found by matching the coverage probabilities of one-sided Baysian credible interval with the corresponding frequentist coverage probabilities. Also the propriety of posterior under the noninformative priors is proved and the frequentist coverage probabilities are investigated for small samples via simulation study.

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