• Communications for Statistical Applications and Methods
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• 제22권6호
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• pp.531-542
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• 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.

• Journal of the Korean Statistical Society
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• 제21권2호
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• pp.93-110
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• 1992

A model selection approach is used to find out whether the mean and the variance of a unique sample are different from the pre-specified values. Normal distribution is selected as an approximating model. Kullback-Leibler discrepancy comes out as a natural measure of discrepancy between the operating model and the approximating model. Several estimates of selection criterion are computed including AIC, TIC, and a coupleof bootstrap estimator of the selection criterion are considered according to the way of resampling. It is shown that a closed form expression is available for the parametric bootstrap estimated cirterion. A Monte Carlo study is provided to give a formal comparison when the operating family itself is normally distributed.

• Journal of the Korean Data and Information Science Society
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• 제21권6호
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• pp.1343-1351
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• 2010

Sample size determination is very important part in clinical trials because it influences the time and the cost of the experimental studies. In this article, we consider the Bayesian methods for sample size determination based on hypothesis testing. Specifically we compare the usual Bayesian method using Bayes factor with the decision theoretic method using Bayesian reference criterion in mean difference problem for the normal case with known variances. We illustrate two procedures numerically as well as graphically.

• 소성∙가공
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• 제7권6호
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• pp.594-602
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• 1998

The design analysis of axisymmetric, multi-stage deep drawing dies was performed using the rigid-viscoplastic finite element formulation. In the formulation the axisymmetric CFS algorithm was employed. Hill's non-quadratic normal anisotropic yield criterion and isotropic hardening rule were considered. For trial initial displacements and tool contact points. the geometric force equilibrium method was adopted. In order to see the validity of the formulation, the multi-stage deep drawing processes of shell-cylinder front part of hydraulic booster were simulated. The simulation showed good agreements with measurments and PAM-STAMP results.

• 응용통계연구
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• 제11권2호
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• pp.435-449
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• 1998

본 연구는 다중판별분석(MDA)에서 필요한 변수선택기준을 베이즈접근법으로 제안하였다. 이 베이즈판별변수 선택기준은 여러 정규모집단분포의 평균벡터에 대한 동질성 검정에 필요한 디폴터형태의 베이즈요인을 객관적 베이즈방법으로 유도하여 설정하였다. 디폴트베이즈요인(default Bayes factor)은 Spiegelhalter와 Smith (1982)가 계발한 가상적트레이닝표본법(imaginary training sample method)을 사용하여서 도출하였다. 또한 제안된 베이즈판별변수선택 기준이 지닌 분포의 성질을 이용하여, 추가 판별변수(또는 변수군)가 MDA에 기여하는 부가적인 판별력에 대한 검정법 및 추가판별변수(또는 변수군)의 선택 기준에 대해서도 논하였다. 본 연구에서 새로이 얻은 변수선택기준은 최적부분집합선택법(optimal subset selection method)뿐 아니라 각 단계적방법(stepwise method)의 변수선택기준으로 사용될 수 있으며, 두 그룹 판별분석에도 사용이 가능하다는 점에서 표본이론에 의해 여러 형태로 개발된 기존의 판별변수 선택 기준들을 하나로 통합시킬 수 있는 기능을 지니고 있다. 모의실험을 실시하여 최적 부분집합선택법과 단계적방법하에서 제안된 판별변수선택 기준이 가진 효용성을 평가하였다.

• 대한기계학회논문집
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• 제16권2호
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• pp.248-258
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• 1992

Three-dimensional rigid-plastic finite element formulation based on the membrane theory was described and a computer program for large deformation analysis was developed. In the formulation, normal and planar anisotropy of sheet material and rotation of the principal axes of anisotropy was taken into consideration. Sheet metal was assumed to be rigid-plastic material obeying Hill's quadratic yield criterion and its associated flow rule. Deep drawing process, as a preliminary test, for normal anisotropic material was analyzed in order to examine the validity of developed finite element program. The results were consistent with the existing finite element solutions or experimental data. The present study was mainly concerned with the influence of planar anisotropy on deformation behaviour. Finite element analysis and experiment were carried out for the whole process of deep drawing of planar anisotropic material. The computational and experimental results on the shape of ear, strain distribution and punch load were in good agreement.

• 한국통신학회논문지
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• 제35권4C호
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• pp.329-336
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• 2010

분산 소스 부호화 시스템은 복호복잡도가 높다는 문제점을 갖는다. 본 논문에서는 신드롬 기반의 분산 소스 부호인 low-density parity check accumulate (LDPCA) 부호의 복호복잡도를 효율적으로 낮추기 위하여 LDPC 부호에 사용되는 각종 정지조건을 LDPCA 복호기에 적용하고 이에 따른 복잡도를 평가하였다. 대표적으로 convergence of mean magnitude (CMM) 정지 조건을 적용하여, 정지 조건을 사용하지 않았을 때보다 압축부호율 손실을 2% 이하로 발생시키며 약 85%의 복호복잡도 감소 효과를 얻을 수 있었다. 더불어 사용되는 부호의 성능을 파악하고 있을 때 초기에 과잉 신드롬을 전송하는 방법과, 채널 정보가 얻기 힘든 경우 기존 정지조건을 부호율 적응적인 LDPCA 부호에 적합하게 수정하는 방법을 제안하였다.

• Structural Engineering and Mechanics
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• 제24권2호
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• pp.137-154
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• 2006

The reliable pushover analysis of RC structures requires a realistic prediction of moment-curvature relations, which can be obtained by utilizing proper constitutive models for the stress-strain relationships of laterally confined concrete members. Theoretical approach of Mander is still a single stress-strain model, which employs a multiaxial failure surface for the determination of the ultimate strength of confined concrete. Alternatively, this paper introduces a simple and practical failure criterion for confined concrete with emphasis on introduction of significant modifications into the two-parameter Drucker-Prager model. The new criterion is only applicable to triaxial compression stress state which is exactly the case in the RC columns. Unlike many existing multi-parameter criteria proposed for the concrete fracture, the model needs only the compressive strength of concrete as an independent parameter and also implies for the influence of the Lode angle on the material strength. Adopting Saenz equation for stress-strain plots, satisfactory agreement between the measured and predicted results for the available experimental test data of confined normal and high strength concrete specimens is obtained. Moreover, it is found that further work involving the confinement pressure is still encouraging since the confinement model of Mander overestimates the ultimate strength of some RC columns.

• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.291-300
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• 2006

In this research, the performance of widely used Bayesian estimators such as Bayes estimator, empirical Bayes estimator, constrained Bayes estimator and constrained empirical Bayes estimator are compared by means of a measurement under balanced loss function for the typical normal-normal situation. The proposed measurement is a weighted sum of the precisions of first and second moments. As a result, one can gets the criterion according to the size of prior variance against the population variance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.435-440
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• 2000

It is shown, in nonlinear two-degree-of freedom system, that the bifurcating modes are created by the stability changes of normal modes. There are four types of stability criterion, each of which gives rise to a distinct functional form of bifurcating modes; the bifurcating mode is born in the form of eigenfunction through which the stability is changed. Then a procedure is formulated to compute the bifurcating mode by the method of harmonic balance. Application of bifurcating mode to forced vibrations is introduced.