• Title/Summary/Keyword: Bayes Factor

Search Result 154, Processing Time 0.021 seconds

Hypotheses Testing for the Shape Parameter of the Weibull Lifetime Data

  • Kang, Sang-Gil;Kim, Dal-Ho;Cho, Jang-Sik
    • Journal of Korean Society for Quality Management
    • /
    • v.27 no.4
    • /
    • pp.153-166
    • /
    • 1999
  • In this paper, we address the Bayesian hypotheses testing for the shape parameter of weibull model. In Bayesian testing problem, conventional Bayes factors can not typically accommodate the use of noninformative priors which are improper and are defined only up to arbitrary constants. To overcome such problem, we use the recently proposed hypotheses testing criterion called the intrinsic Bayes factor. We derive the arithmetic and median intrinsic Bayes factors and use these results to analyze real data sets.

  • PDF

A Bayesian Test Criterion for the Behrens-Firsher Problem

  • Kim, Hea-Jung
    • Communications for Statistical Applications and Methods
    • /
    • v.6 no.1
    • /
    • pp.193-205
    • /
    • 1999
  • An approximate Bayes criterion for Behrens-Fisher problem (testing equality of means of two normal populations with unequal variances) is proposed and examined. Development of the criterion involves derivation of approximate Bayes factor using the imaginary training sample approachintroduced by Spiegelhalter and Smith (1982). The proposed criterion is designed to develop a Bayesian test criterion having a closed form, so that it provides an alternative test to those based upon asymptotic sampling theory (such as Welch's t test). For the suggested Bayes criterion, numerical study gives comparisons with a couple of asymptotic classical test criteria.

  • PDF

Bayes Factors for Independence and Symmetry in Freund's Bivariate Exponetial Model with Censored Data

  • Jang Sik;Dal Ho;Sang Gil
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.1
    • /
    • pp.151-164
    • /
    • 2000
  • In this paper we consider the Bayesian hypothese testing for independence and symmetry in Freund's bivariate exponential model with censored data In Bayesian testing problem we use the noninformative priors for parameters which are improper and are defined only up to arbitrary constants. And we use the recently proposed hypotheses testing criterion called the intrinsic Bayes factor. Also we derive the arithmetic and median intrinsic Bayes factors and use these results of analyze some data sets.

  • PDF

A Bayes Criterion for Selecting Variables in MDA (MDA에서 판별변수 선택을 위한 베이즈 기준)

  • 김혜중;유희경
    • The Korean Journal of Applied Statistics
    • /
    • v.11 no.2
    • /
    • pp.435-449
    • /
    • 1998
  • In this article we have introduced a Bayes criterion for the variable selection in multiple discriminant analysis (MDA). The criterion is a default Bayes factor for the comparision of homo/heteroscadasticity of the multivariate normal means. The default Bayes factor is obtained from a development of the imaginary training sample method introduced by Spiegelhalter and Smith (1982). Based an the criterion, we also provided a test for additional discrimination in MDA. The advantage of the criterion is that it is not only applicable for the optimal subset selection method but for the stepwise method. More over, the criterion can be reduced to that for two-group discriminant analysis. Thus the criterion can be regarded as an unified alternative to variable selection criteria suggested by various sampling theory approaches. To illustrate the performance of the criterion, a numerical study has bean done via Monte Carlo experiment.

  • PDF

Bayesian Test for Equality of Coefficients of Variation in the Normal Distributions

  • Lee, Hee-Choon;Kang, Sang-Gil;Kim, Dal-Ho
    • 한국데이터정보과학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.49-56
    • /
    • 2003
  • When X and Y have independent normal distributions, we develop a Bayesian testing procedure for the equality of two coefficients of variation. Under the reference prior of the coefficient of variation, we propose a Bayesian test procedure for the equality of two coefficients of variation using fractional Bayes factor. A real data example is provided.

  • PDF

Bayesian Multiple Comparisons for the Ratio of the Failure Rates in Two Components System

  • Cho, Jang-Sik;Cho, Kil-Ho
    • Journal of the Korean Data and Information Science Society
    • /
    • v.17 no.2
    • /
    • pp.647-655
    • /
    • 2006
  • In this paper, we consider multiple comparisons for the ratio of the failure rates in two components system that the lifetimes of the components have independent exponential distributions. Also we suggest Bayesian multiple comparisons procedure based on fractional Bayes factor when noninformative priors are applied for the parameters. Finally, we give numerical examples to illustrate our procedure.

  • PDF

Bayesian Testing for Independence in Bivariate Exponential Model

  • Cho, Jang-Sik
    • Journal of the Korean Data and Information Science Society
    • /
    • v.17 no.2
    • /
    • pp.521-527
    • /
    • 2006
  • In this paper, we consider the Bayesian hypotheses testing for independence in bivariate exponential model. In Bayesian testing problem, we use the noninformative priors for parameters which are improper and are defined only up to arbitrary constants. And we use the recently proposed hypotheses testing criterion called the fractional Bayes factor. Also we give some numerical results to illustrate our results.

  • PDF

Bayesian Testing for the Equality of Two Inverse Gaussian Populations with the Fractional Bayes Factor

  • Ko, Jeong-Hwan
    • Journal of the Korean Data and Information Science Society
    • /
    • v.16 no.3
    • /
    • pp.539-547
    • /
    • 2005
  • We propose the Bayesian testing for the equality of two independent Inverse Gaussian population means using the fractional Bayesian factors suggested by O' Hagan(1995). As prior distribution for the parameters, we assumed the noninformative priors. In order to investigate the usefulness of the proposed Bayesian testing procedures, the behaviors of the proposed results are examined via real data analysis.

  • PDF

로그정규모집단에서의 베이지안 모형선택

  • 이우동
    • Proceedings of the Korea Society for Industrial Systems Conference
    • /
    • 1998.10a
    • /
    • pp.807-813
    • /
    • 1998
  • 이 논문에서는 로그정규분포에 대한 베이지안 모형선택방법을 제안한다. 일반적으로 , 모수에 대한 사전정보가 비정보적(noninformative)인 경우, 베이즈 요인(Bayes factor)은 결정할 수 없는 상수를 포함하는 것이 일반적이다. 이 경우, 베이즈 요인을 계산하기 위해 최근 활발히 연구중인 고유 베이즈 요인(Intrinsic Bayes factor)방법을 이용한다. 실제의 자료를 통해 로그정규분포의 적합도 검정에 대한 부분적 베이즈 요인을 계산한다.

메타분석에서 그룹화 임의효과 모형의 베이지안 해석

  • 정윤식;정호진
    • The Korean Journal of Applied Statistics
    • /
    • v.13 no.1
    • /
    • pp.81-96
    • /
    • 2000
  • 본 논문은 의학분야에서 주로 사용되는 메타분석 중 그룹화 임의효과 모형(grouped random effects model)을 프라빗 연결함수(probit link function)를 이용하여 베이즈적 관점에서 연구하였다. 이때 프라빗 함수를 강요하기 위해 잠재변수를 정의하였고, 사전 분포를 달리한 세가지 모형을 고려하였다. 주어진 세가지 모형들에게서 적합한 모형 선택을 위하여 베이즈 인자(Bayes factor, BF)와 유사베이즈 인자(pseudo-Bayes factor, PsBF)를 이용하였다. 깁스샘플러와 메트로폴리스 알고리즘을 이용하여 베이지안 계산상의 어려움을 해결하였다. 예로써, 새로운 간질약에 대한 효과를 조사하기 위하여 앞에서 제시된 방법으로 해석하였다.

  • PDF