• Title/Summary/Keyword: Bayesian model

Search Result 1,312, Processing Time 0.031 seconds

PERFORMANCE EVALUATION OF INFORMATION CRITERIA FOR THE NAIVE-BAYES MODEL IN THE CASE OF LATENT CLASS ANALYSIS: A MONTE CARLO STUDY

  • Dias, Jose G.
    • Journal of the Korean Statistical Society
    • /
    • v.36 no.3
    • /
    • pp.435-445
    • /
    • 2007
  • This paper addresses for the first time the use of complete data information criteria in unsupervised learning of the Naive-Bayes model. A Monte Carlo study sets a large experimental design to assess these criteria, unusual in the Bayesian network literature. The simulation results show that complete data information criteria underperforms the Bayesian information criterion (BIC) for these Bayesian networks.

A BAYESIAN APPROACH TO THE IMPERFECT INSPECTION MODEL

  • Park, Choon-Il
    • Journal of applied mathematics & informatics
    • /
    • v.6 no.2
    • /
    • pp.589-598
    • /
    • 1999
  • Classification errors are included in sampling -with -re-placement model where items are sampled from a Bernoulli process. Bayesian imperfect inspection model is considered. In addition con-jugate prior and predctive densities for imperfect inspection model are obtained.

Economic Design of Bayesian Acceptance Sampling Plans for Dependent Production Process (종속 생산공정에 대한 Bayesian 샘플링 검사방식의 경제적 설계)

  • Shin, Wan Seon;Kim, Dae Joong
    • Journal of Korean Society for Quality Management
    • /
    • v.22 no.1
    • /
    • pp.96-112
    • /
    • 1994
  • This article studies the design of Bayesian single attribute acceptance sampling plans under dependent production processes. An economic model is constructed by extending the mathematical model developed for non-Bayesian cases for Bayesian cases. The mathematical structure of the model is analyzed and it is used to prove that optimization of the model can be achieved by applying the solution method developed for non-Bayesian models directly. The effect of dependence patterns and the types of prior distributions on the design of sampling plans is also investigated through a computational study.

  • PDF

Software Quality Classification using Bayesian Classifier (베이지안 분류기를 이용한 소프트웨어 품질 분류)

  • Hong, Euy-Seok
    • Journal of Information Technology Services
    • /
    • v.11 no.1
    • /
    • pp.211-221
    • /
    • 2012
  • Many metric-based classification models have been proposed to predict fault-proneness of software module. This paper presents two prediction models using Bayesian classifier which is one of the most popular modern classification algorithms. Bayesian model based on Bayesian probability theory can be a promising technique for software quality prediction. This is due to the ability to represent uncertainty using probabilities and the ability to partly incorporate expert's knowledge into training data. The two models, Na$\ddot{i}$veBayes(NB) and Bayesian Belief Network(BBN), are constructed and dimensionality reduction of training data and test data are performed before model evaluation. Prediction accuracy of the model is evaluated using two prediction error measures, Type I error and Type II error, and compared with well-known prediction models, backpropagation neural network model and support vector machine model. The results show that the prediction performance of BBN model is slightly better than that of NB. For the data set with ambiguity, although the BBN model's prediction accuracy is not as good as the compared models, it achieves better performance than the compared models for the data set without ambiguity.

Uncertainty Analysis of Parameters of Spatial Statistical Model Using Bayesian Method for Estimating Spatial Distribution of Probability Rainfall (확률강우량의 공간분포추정에 있어서 Bayesian 기법을 이용한 공간통계모델의 매개변수 불확실성 해석)

  • Seo, Young-Min;Park, Ki-Bum;Kim, Sung-Won
    • Journal of Environmental Science International
    • /
    • v.20 no.12
    • /
    • pp.1541-1551
    • /
    • 2011
  • This study applied the Bayesian method for the quantification of the parameter uncertainty of spatial linear mixed model in the estimation of the spatial distribution of probability rainfall. In the application of Bayesian method, the prior sensitivity analysis was implemented by using the priors normally selected in the existing studies which applied the Bayesian method for the puppose of assessing the influence which the selection of the priors of model parameters had on posteriors. As a result, the posteriors of parameters were differently estimated which priors were selected, and then in the case of the prior combination, F-S-E, the sizes of uncertainty intervals were minimum and the modes, means and medians of the posteriors were similar to the estimates using the existing classical methods. From the comparitive analysis between Bayesian and plug-in spatial predictions, we could find that the uncertainty of plug-in prediction could be slightly underestimated than that of Bayesian prediction.

Statistical Method for Implementing the Experimenter Effect in the Analysis of Gene Expression Data

  • Kim, In-Young;Rha, Sun-Young;Kim, Byung-Soo
    • Communications for Statistical Applications and Methods
    • /
    • v.13 no.3
    • /
    • pp.701-718
    • /
    • 2006
  • In cancer microarray experiments, the experimenter or patient which is nested in each experimenter often shows quite heterogeneous error variability, which should be estimated for identifying a source of variation. Our study describes a Bayesian method which utilizes clinical information for identifying a set of DE genes for the class of subtypes as well as assesses and examines the experimenter effect and patient effect which is nested in each experimenter as a source of variation. We propose a Bayesian multilevel mixed effect model based on analysis of covariance (ANACOVA). The Bayesian multilevel mixed effect model is a combination of the multilevel mixed effect model and the Bayesian hierarchical model, which provides a flexible way of defining a suitable correlation structure among genes.

Saliency Detection based on Global Color Distribution and Active Contour Analysis

  • Hu, Zhengping;Zhang, Zhenbin;Sun, Zhe;Zhao, Shuhuan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.12
    • /
    • pp.5507-5528
    • /
    • 2016
  • In computer vision, salient object is important to extract the useful information of foreground. With active contour analysis acting as the core in this paper, we propose a bottom-up saliency detection algorithm combining with the Bayesian model and the global color distribution. Under the supports of active contour model, a more accurate foreground can be obtained as a foundation for the Bayesian model and the global color distribution. Furthermore, we establish a contour-based selection mechanism to optimize the global-color distribution, which is an effective revising approach for the Bayesian model as well. To obtain an excellent object contour, we firstly intensify the object region in the source gray-scale image by a seed-based method. The final saliency map can be detected after weighting the color distribution to the Bayesian saliency map, after both of the two components are available. The contribution of this paper is that, comparing the Harris-based convex hull algorithm, the active contour can extract a more accurate and non-convex foreground. Moreover, the global color distribution can solve the saliency-scattered drawback of Bayesian model, by the mutual complementation. According to the detected results, the final saliency maps generated with considering the global color distribution and active contour are much-improved.

A hierarchical Bayesian model for spatial scaling method: Application to streamflow in the Great Lakes basin

  • Ahn, Kuk-Hyun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2018.05a
    • /
    • pp.176-176
    • /
    • 2018
  • This study presents a regional, probabilistic framework for estimating streamflow via spatial scaling in the Great Lakes basin, which is the largest lake system in the world. The framework follows a two-fold strategy including (1) a quadratic-programming based optimization model a priori to explore the model structure, and (2) a time-varying hierarchical Bayesian model based on insights found in the optimization model. The proposed model is developed to explore three innovations in hierarchical modeling for reconstructing historical streamflow at ungaged sites: (1) information of physical characteristics is utilized in spatial scaling, (2) a time-varying approach is introduced based on climate information, and (3) heteroscedasticity in residual errors is considered to improve streamflow predictive distributions. The proposed model is developed and calibrated in a hierarchical Bayesian framework to pool regional information across sites and enhance regionalization skill. The model is validated in a cross-validation framework along with four simpler nested formulations and the optimization model to confirm specific hypotheses embedded in the full model structure. The nested models assume a similar hierarchical Bayesian structure to our proposed model with their own set of simplifications and omissions. Results suggest that each of three innovations improve historical out-of-sample streamflow reconstructions although these improvements vary corrsponding to each innovation. Finally, we conclude with a discussion of possible model improvements considered by additional model structure and covariates.

  • PDF

On loss functions for model selection in wavelet based Bayesian method

  • Park, Chun-Gun
    • Journal of the Korean Data and Information Science Society
    • /
    • v.20 no.6
    • /
    • pp.1191-1197
    • /
    • 2009
  • Most Bayesian approaches to model selection of wavelet analysis have drawbacks that computational cost is expensive to obtain accuracy for the fitted unknown function. To overcome the drawback, this article introduces loss functions which are criteria for level dependent threshold selection in wavelet based Bayesian methods with arbitrary size and regular design points. We demonstrate the utility of these criteria by four test functions and real data.

  • 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