• Journal of the Korean Data and Information Science Society
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• 제21권3호
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• pp.569-574
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• 2010

We consider two components system which have Freund's bivariate exponential model. In this case, Bayesian multiple comparisons procedure for failure rates is sug-gested in K Freund's bivariate exponential populations. Here we assume that the com-ponents enter the study at random over time and the analysis is carried out at some prespeci ed time. We derive fractional Bayes factor for all comparisons under non- informative priors for the parameters and calculate the posterior probabilities for all hypotheses. And we select a hypotheses which has the highest posterior probability as best model. Finally, we give a numerical examples to illustrate our procedure.

• 응용통계연구
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• 제21권4호
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• pp.659-664
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• 2008

Missing continuous covariates are pervasive in the use of generalized linear models for medical data. Multiple imputation is the most common and easy-to-do method of dealing with missing covariate data. However, there are always serious warnings in using this method. There should be concern to make imputed values more proper. In this paper, proper imputation from posterior predictive distribution is developed for implementing with arbitrary priors. We use empirical distribution of the posterior for approximating the posterior predictive distribution, to sample from it. This method is preferable in comparison with a presented imputation method of us which uses a full model to impute missing values using available software. The proposed methods are implemented on glucocorticoid data.

• 응용통계연구
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• 제27권6호
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• pp.909-922
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• 2014

부등제한 조건 (>,<,=)과 관련된 베이지안 추론에서 다음의 세 가지 주제에 대하여 기존의 연구와 최근의 연구동향 그리고 추후 연구주제에 대하여 살펴보았다 : ⅰ) 모수에 대한 여러 부등제한 조건들의 비교, ⅱ) 모수에 부등제한 조건을 부여하는 것이 타당하다고 할 때 모수의 동등성에 관한 동시 다중 검정, ⅲ) 순서적 범주형 변수에 대한 분할표에서 스코어 모수에 순서적 부등제한 조건을 가정 할 때 스코어 모수의 동등성에 대한 다중 검정.

• 한국환경보건학회지
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• 제38권6호
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• pp.550-560
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• 2012

Objectives: QSAR methodology was applied to explain two different sets of acceptable daily intake (ADI) data of 74 pesticides proposed by both the USEPA and WHO in terms of setting guidelines for food and drinking water. Methods: A subset of calculated descriptors was selected from Dragon$^{(R)}$ software. QSARs were then developed utilizing a statistical technique, genetic algorithm-multiple linear regression (GA-MLR). The differences in each specific model in the prediction of the ADI of the pesticides were discussed. Results: The stepwise multiple linear regression analysis resulted in a statistically significant QSAR model with five descriptors. Resultant QSAR models were robust, showing good utility across multiple classes of pesticide compounds. The applicability domain was also defined. The proposed models were robust and satisfactory. Conclusions: The QSAR model could be a feasible and effective tool for predicting ADI and for the comparison of logADIEPA to logADIWHO. The statistical results agree with the fact that USEPA focuses on more subtle endpoints than does WHO.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1238-1243
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• 2002

In this study, the validity of the acoustic impedance model and the estimation model by electro-acoustic analogy suggested by Maa for predicting the absorptive performance of multiple layer perforated plate systems is investigated. From the comparison between the experiment and calculation for the absorption performance of double layer perforated plate system, the calculated results of using Rao and Munjal's impedance model and transfer matrix method are closer to the experimental values than those of using Maa's impedance model and electro-acoustic analogy. Therefore, in order to apply the acoustic impedance model and the estimation model by electro-acoustic analogy suggested by Maa to the multiple layer perforated plate systems, it is necessary that the suggested acoustic impedance and estimation models should be re-examined.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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• pp.71-80
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• 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.

• 천문학회보
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• 제41권1호
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• pp.49.3-50
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• 2016

Two major radiative transfer (RT) techniques have been developted to model late-type galaxies: approximate RT and Monte Carlo (MC) RT. In the approximate RT, first proposed by Kylafis & Bahcall, only two terms of unscattered (direct) and single-scattered intensities are computed and higher-order multiple scattering components are approximated, saving computing time and cost compared to MC RT. However, the approximate RT can yield errors in regions where multiple scattering effect is significant. In order to examine how significant the errors of the approximate RT are, we compare results of the approximate RT with those of SKIRT, a state-of-the-art MC RT code, which is basically free from the approximation errors by fully incorporating all the multiple scattered intensities. In this study, we present quantitative errors in the approximate RT for late type galaxy models with various optical depths and inclination angles. We report that the approximate RT is not reliable if the central face-on optical depth is intermediate or high (${\tau}_V$ > 3).

• 산업경영시스템학회지
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• 제36권3호
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• pp.17-24
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• 2013

Release planning in a software product line (SPL) is to select and assign the features of the multiple software products in the SPL in sequence of releases along a specified planning horizon satisfying the numerous constraints regarding technical precedence, conflicting priorities for features, and available resources. A greedy genetic algorithm is designed to solve the problems of release planning in SPL which is formulated as a precedence-constrained multiple 0-1 knapsack problem. To be guaranteed to obtain feasible solutions after the crossover and mutation operation, a greedy-like heuristic is developed as a repair operator and reflected into the genetic algorithm. The performance of the proposed solution methodology in this research is tested using a fractional factorial experimental design as well as compared with the performance of a genetic algorithm developed for the software release planning. The comparison shows that the solution approach proposed in this research yields better result than the genetic algorithm.

• 한국위성정보통신학회논문지
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• 제9권2호
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• pp.114-118
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• 2014

본 논문에서는 내 부호의 복호화 방식에 따른 쇄상부호 시스템의 성능 변화를 분석한다. 내 부호의 복화화 방식으로는 오류 검출 방식과 오류 검출 및 정정 방식의 두 가지를 고려한다. 주파수 도약 대역확산 다중접속 통신시스템에 쇄상부호가 적용되었을 때 두 복호화 방식에 따른 성능을 비교하는데, 외 부호의 블록 길이가 유한한 경우와 무한한 경우에 그 성능을 분석하고 비교한다. 분석된 결과를 바탕으로 무한의 블록 길이의 경우에는 두 방식의 성능이 다중 접속자 수에 따라서 trade-off가 있음을 알 수 있고, 유한한 블록 길이의 경우에는 오류 검출 및 정정 방식의 성능이 더 우수함을 관찰하였다.

• Communications for Statistical Applications and Methods
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• 제3권2호
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• pp.53-67
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• 1996

Numerous classical as well as robust methods have been proposed in the literature for the detection of multiple outlier in multivariate data. The effectiveness and power of each of these methods have not been thoroughly investigated. In this paper we first reduce the vast number of outlier detection methods to a small number of viable ones. This reduction is based on previous work of other researches and on some theoretical arguments. Then we design and implement a Monte Carlo experiment for comparing these methods. The main goal of our study is to determine which methods are most powerful in the detection of multiple outlier and in dealing with the masking and swamping problems. The results of the Monte Carlo study indicate that two of the methods seem to hace better performances than the others for the detection of multiple outlier in multivariate data.