• Title/Summary/Keyword: Exponential family

Search Result 69, Processing Time 0.03 seconds

Estimation of Pr(X>Y) in the case of Exponential X and Normal Y

  • Kim, Jae-Joo;Kim, Hwan-Joong
    • Journal of Korean Society for Quality Management
    • /
    • v.15 no.2
    • /
    • pp.27-37
    • /
    • 1987
  • In life testing problem, many authors obtained the minimum variance unbiased estimator of $P_r$[X>Y] for the exponential family generally and conceptually. In this paper, we study the maximum likelihood estimator and minimum variance unbiased estimator of $P_r$[X>Y] in exponential X and normal Y.

  • PDF

Multiple Comparisons for a Bivariate Exponential Populations Based On Dirichlet Process Priors

  • Cho, Jang-Sik
    • Journal of the Korean Data and Information Science Society
    • /
    • v.18 no.2
    • /
    • pp.553-560
    • /
    • 2007
  • In this paper, we consider two components system which lifetimes have Freund's bivariate exponential model with equal failure rates. We propose Bayesian multiple comparisons procedure for the failure rates of I Freund's bivariate exponential populations based on Dirichlet process priors(DPP). The family of DPP is applied in the form of baseline prior and likelihood combination to provide the comparisons. Computation of the posterior probabilities of all possible hypotheses are carried out through Markov Chain Monte Carlo(MCMC) method, namely, Gibbs sampling, due to the intractability of analytic evaluation. The whole process of multiple comparisons problem for the failure rates of bivariate exponential populations is illustrated through a numerical example.

  • PDF

Molecular Cloning and Characterization of DNA Repair Related Gene in Yeast

  • Kang, Seon-Ah;Park, In-Soon
    • Journal of Life Science
    • /
    • v.10 no.1
    • /
    • pp.40-44
    • /
    • 2000
  • The SNF2/SW ATPase/helicase family comprises proteins form a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Here, we reported the characterization of h게2+gene which was iolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of PCR product showed striking evolutionary conservation among the SNF2 family of proteins. Two transcripts of 6.7 and 3.4 Lb were detected by Northern blot analysis. furthermore, the intensities of these two bands were increased by ultraviolet(UV) irradiation. These results indicate that the hrp2+ is a novel member of the SNF2 family of proteins and is one of the UV-inducible genes in S. pombe. To determine the level of transcripts of hrp2+ gene during cellular growth, Northern blot analysis were performed. This result indicates that the level of hrp2+transcript reached its maximum before cells entered the exponential growth phase. This suggests that hrp2+ gene is experssed mainly at the early stage of cell growth.

Nonparametric Bayesian Multiple Comparisons for Dependence Parameter in Bivariate Exponential Populations

  • Cho, Jang-Sik;Ali, M. Masoom;Begum, Munni
    • 한국데이터정보과학회:학술대회논문집
    • /
    • 2006.11a
    • /
    • pp.71-80
    • /
    • 2006
  • A nonparametric Bayesian multiple comparisons problem (MCP) for dependence parameters in I bivariate exponential populations is studied here. A simple method for pairwise comparisons of these parameters is also suggested. Here we extend the methodology studied by Gopalan and Berry (1998) using Dirichlet process priors. The family of Dirichlet process priors is applied in the form of baseline prior and likelihood combination to provide the comparisons. Computation of the posterior probabilities of all possible hypotheses are carried out through Markov Chain Monte Carlo method, namely, Gibbs sampling, due to the intractability of analytic evaluation. The whole process of MCP for the dependent parameters of bivariate exponential populations is illustrated through a numerical example.

  • PDF

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

  • Yoon, Byoung-Chang;Kim, Jea-Joo
    • Journal of the Korean Statistical Society
    • /
    • v.10
    • /
    • pp.128-139
    • /
    • 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.

  • PDF

Computation and Smoothing Parameter Selection In Penalized Likelihood Regression

  • Kim Young-Ju
    • Communications for Statistical Applications and Methods
    • /
    • v.12 no.3
    • /
    • pp.743-758
    • /
    • 2005
  • This paper consider penalized likelihood regression with data from exponential family. The fast computation method applied to Gaussian data(Kim and Gu, 2004) is extended to non Gaussian data through asymptotically efficient low dimensional approximations and corresponding algorithm is proposed. Also smoothing parameter selection is explored for various exponential families, which extends the existing cross validation method of Xiang and Wahba evaluated only with Bernoulli data.

CHARACTERIZATIONS OF SOME POLYNOMIAL VARIANCE FUNCTIONS BY d-PSEUDO-ORTHOGONALITY

  • KOKONENDJI CELESTIN C.
    • Journal of applied mathematics & informatics
    • /
    • v.19 no.1_2
    • /
    • pp.427-438
    • /
    • 2005
  • From a notion of d-pseudo-orthogonality for a sequence of poly-nomials ($d\;\in\;{2,3,\cdots}$), this paper introduces three different characterizations of natural exponential families (NEF's) with polynomial variance functions of exact degree 2d-1. These results provide extended versions of the Meixner (1934), Shanbhag (1972, 1979) and Feinsilver (1986) characterization results of quadratic NEF's based on classical orthogonal polynomials. Some news sets of polynomials with (2d-1)-term recurrence relation are then pointed out and we completely illustrate the cases associated to the families of positive stable distributions.

How to Improve Classical Estimators via Linear Bayes Method?

  • Wang, Lichun
    • Communications for Statistical Applications and Methods
    • /
    • v.22 no.6
    • /
    • pp.531-542
    • /
    • 2015
  • In this survey, we use the normal linear model to demonstrate the use of the linear Bayes method. The superiorities of linear Bayes estimator (LBE) over the classical UMVUE and MLE are established in terms of the mean squared error matrix (MSEM) criterion. Compared with the usual Bayes estimator (obtained by the MCMC method) the proposed LBE is simple and easy to use with numerical results presented to illustrate its performance. We also examine the applications of linear Bayes method to some other distributions including two-parameter exponential family, uniform distribution and inverse Gaussian distribution, and finally make some remarks.

Three Stage Estimation for the Mean of a One-Parameter Exponential Family

  • M. AlMahmeed;A. Al-Hessainan;Son, M.S.;H. I. Hamdy
    • Communications for Statistical Applications and Methods
    • /
    • v.5 no.2
    • /
    • pp.539-557
    • /
    • 1998
  • This article is concerned with the problem of estimating the mean of a one-parameter exponential family through sequential sampling in three stages under quadratic error loss. This more general framework differs from those considered by Hall (1981) and others. The differences are : (i) the estimator and the final stage sample size are dependent; and (ii) second order approximation of a continuously differentiable function of the final stage sample size permits evaluation of the asymptotic regret through higher order moments. In particular, the asymptotic regret can be expressed as a function of both the skewness $\rho$ and the kurtosis $\beta$ of the underlying distribution. The conditions on $\rho$ and $\beta$ for which negative regret is expected are discussed. Further results concerning the stopping variable N are also presented. We also supplement our theoretical findings wish simulation results to provide a feel for the triple sampling procedure presented in this study.

  • PDF

Criterion of discrete unimodal mixtures (이산분포 혼합의 단봉성이 성립하기 위한 조건)

  • 최대우
    • The Korean Journal of Applied Statistics
    • /
    • v.8 no.1
    • /
    • pp.159-167
    • /
    • 1995
  • Considering special discrete distribution of exponential family as a sequence with respect to the points of support, the squence is unimodal in some sense. In this paper, we study under what condition the mixture of that discrete distribution with respect to a parameter is unimodal. We derive the maximal interval of the parameter in which each mixture of the discrete distribution such as Binomial and Poisson is always unimodal.

  • PDF