• Title/Summary/Keyword: Bayesian Algorithm

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An integrated Bayesian network framework for reconstructing representative genetic regulatory networks.

  • Lee, Phil-Hyoun;Lee, Do-Heon;Lee, Kwang-Hyung
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2003.10a
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    • pp.164-169
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    • 2003
  • In this paper, we propose the integrated Bayesian network framework to reconstruct genetic regulatory networks from genome expression data. The proposed model overcomes the dimensionality problem of multivariate analysis by building coherent sub-networks from confined gene clusters and combining these networks via intermediary points. Gene Shaving algorithm is used to cluster genes that share a common function or co-regulation. Retrieved clusters incorporate prior biological knowledge such as Gene Ontology, pathway, and protein protein interaction information for extracting other related genes. With these extended gene list, system builds genetic sub-networks using Bayesian network with MDL score and Sparse Candidate algorithm. Identifying functional modules of genes is done by not only microarray data itself but also well-proved biological knowledge. This integrated approach can improve there liability of a network in that false relations due to the lack of data can be reduced. Another advantage is the decreased computational complexity by constrained gene sets. To evaluate the proposed system, S. Cerevisiae cell cycle data [1] is applied. The result analysis presents new hypotheses about novel genetic interactions as well as typical relationships known by previous researches [2].

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Clinical Pharmacokinetics of Gentamicin in Appendicitis Patients (충수돌기염 환자에서 겐타마이신의 임상약물동태)

  • Cho Jun-Shik;Jung HaeGwang;Burm Jin Pil;Lee JinHwan;Kim SungHwan
    • Korean Journal of Clinical Pharmacy
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    • v.5 no.2
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    • pp.1-12
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    • 1995
  • The purpose of this investigation was to determine pharmacokinetic parameters of gentamicin using linear least square regression(LLSR) and Bayesian analysis in Korean normal volunteers and appendicitis patients. Nonparametric expected maximum(NPEM) algorithm for population pharmacokinetic parameters was used. Gentamicin was administered every 8 hours for 3 days by infusion over 30 minutes. The volume of distribution(V) and elimination rate constant(K) of gentamicin were $0.215\pm0.0562,\;0.226\pm0.0325L/kg\;and\;0.339\pm0.0443,\;0.357\pm0.0243hr^{-1}$ for normal volunteers and appendicitis patients using LLSR analysis. Population pharmacokinetic parameters, VS and KS were $0.228\pm0.0614L/kg\;and\;0.00356\pm0.00041(hr{\cdot}mL/min/1.73m^2)^{-1}$ for appendicitis patients using NPEM algorithm. The V and K were $0.232\pm0.0568L/kg\;and\;0.337\pm0.0385hr^{-1}$ for appendicitis patients using Bayesian analysis. There were no differences in gentamicin pharmacokinetics between LLSR and Bayesian analysis.

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Region Growing Based Variable Window Size Decision Algorithm for Image Denoising (영상 잡음 제거를 위한 영역 확장 기반 가변 윈도우 크기 결정 알고리즘)

  • 엄일규;김유신
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.111-116
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    • 2004
  • It is essential to know the information about the prior model for wavelet coefficients, the probability distribution of noise, and the variance of wavelet coefficients for noise reduction using Bayesian estimation in wavelet domain. In general denoising methods, the signal variance is estimated from the proper prior model for wavelet coefficients. In this paper, we propose a variable window size decision algorithm to estimate signal variance according to image region. Simulation results shows the proposed method have better PSNRs than those of the state of art denoising methods.

Real-Time Motion Estimation Algorithm for Mobile Surveillance Robot (모바일 감시 로봇을 위한 실시간 움직임 추정 알고리즘)

  • Han, Cheol-Hoon;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.311-316
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    • 2009
  • This paper presents the motion estimation algorithm on real-time for mobile surveillance robot using particle filter. the particle filter that based on the monte carlo's sampling method, use bayesian conditional probability model which having prior distribution probability and posterior distribution probability. However, the initial probability density was set to define randomly in the most of particle filter. In this paper, we find first the initial probability density using Sum of Absolute Difference(SAD). and we applied it in the partical filter. In result, more robust real-time estimation and tracking system on the randomly moving object was realized in the mobile surveillance robot environments.

A Bayesian cure rate model with dispersion induced by discrete frailty

  • Cancho, Vicente G.;Zavaleta, Katherine E.C.;Macera, Marcia A.C.;Suzuki, Adriano K.;Louzada, Francisco
    • Communications for Statistical Applications and Methods
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    • v.25 no.5
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    • pp.471-488
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    • 2018
  • In this paper, we propose extending proportional hazards frailty models to allow a discrete distribution for the frailty variable. Having zero frailty can be interpreted as being immune or cured. Thus, we develop a new survival model induced by discrete frailty with zero-inflated power series distribution, which can account for overdispersion. This proposal also allows for a realistic description of non-risk individuals, since individuals cured due to intrinsic factors (immunes) are modeled by a deterministic fraction of zero-risk while those cured due to an intervention are modeled by a random fraction. We put the proposed model in a Bayesian framework and use a Markov chain Monte Carlo algorithm for the computation of posterior distribution. A simulation study is conducted to assess the proposed model and the computation algorithm. We also discuss model selection based on pseudo-Bayes factors as well as developing case influence diagnostics for the joint posterior distribution through ${\psi}-divergence$ measures. The motivating cutaneous melanoma data is analyzed for illustration purposes.

A Signal Subspace Interference Alignment Scheme with Sum Rate Maximization and Altruistic-Egoistic Bayesian Gaming

  • Peng, Shixin;Liu, Yingzhuang;Chen, Hua;Kong, Zhengmin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.6
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    • pp.1926-1945
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    • 2014
  • In this paper, we propose a distributed signal subspace interference alignment algorithm for single beam K-user ($3K{\geq}$) MIMO interference channel based on sum rate maximization and game theory. A framework of game theory is provided to study relationship between interference signal subspace and altruistic-egoistic bayesian game cost function. We demonstrate that the asymptotic interference alignment under proposed scheme can be realized through a numerical algorithm using local channel state information at transmitters and receivers. Simulation results show that the proposed scheme can achieve the total degrees of freedom that is equivalent to the Cadambe-Jafar interference alignment algorithms with perfect channel state information. Furthermore, proposed scheme can effectively minimize leakage interference in desired signal subspace at each receiver and obtain a moderate average sum rate performance compared with several existing interference alignment schemes.

A Bayesian Approach for Accelerated Failure Time Model with Skewed Normal Error

  • Kim, Chansoo
    • Communications for Statistical Applications and Methods
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    • v.10 no.2
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    • pp.268-275
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    • 2003
  • We consider the Bayesian accelerated failure time model. The error distribution is assigned a skewed normal distribution which is including normal distribution. For noninformative priors of regression coefficients, we show the propriety of posterior distribution. A Markov Chain Monte Carlo algorithm(i.e., Gibbs Sampler) is used to obtain a predictive distribution for a future observation and Bayes estimates of regression coefficients.

Semiparametric Bayesian multiple comparisons for Poisson Populations

  • Cho, Jang Sik;Kim, Dal Ho;Kang, Sang Gil
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.427-434
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    • 2001
  • In this paper, we consider the nonparametric Bayesian approach to the multiple comparisons problem for I Poisson populations using Dirichlet process priors. We describe Gibbs sampling algorithm for calculating posterior probabilities for the hypotheses and calculate posterior probabilities for the hypotheses using Markov chain Monte Carlo. Also we provide a numerical example to illustrate the developed numerical technique.

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Inference of Parameters for Superposition with Goel-Okumoto model and Weibull model Using Gibbs Sampler

  • Heecheul Kim
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.169-180
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    • 1999
  • A Markov Chain Monte Carlo method with development of computation is used to be the software system reliability probability model. For Bayesian estimator considering computational problem and theoretical justification we studies relation Markov Chain with Gibbs sampling. Special case of GOS with Superposition for Goel-Okumoto and Weibull models using Gibbs sampling and Metropolis algorithm considered. In this paper discuss Bayesian computation and model selection using posterior predictive likelihood criterion. We consider in this paper data using method by Cox-Lewis. A numerical example with a simulated data set is given.

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Bayesian Parameter :Estimation and Variable Selection in Random Effects Generalised Linear Models for Count Data

  • Oh, Man-Suk;Park, Tae-Sung
    • Journal of the Korean Statistical Society
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    • v.31 no.1
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    • pp.93-107
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    • 2002
  • Random effects generalised linear models are useful for analysing clustered count data in which responses are usually correlated. We propose a Bayesian approach to parameter estimation and variable selection in random effects generalised linear models for count data. A simple Gibbs sampling algorithm for parameter estimation is presented and a simple and efficient variable selection is done by using the Gibbs outputs. An illustrative example is provided.