• 대한수학회지
• /
• 제52권3호
• /
• pp.489-501
• /
• 2015

We study the structure of right duo ring property when it is restricted within the group of units, and introduce the concept of right unit-duo. This newly introduced property is first observed to be not left-right symmetric, and we examine several conditions to ensure the symmetry. Right unit-duo rings are next proved to be Abelian, by help of which the class of noncommutative right unit-duo rings of minimal order is completely determined up to isomorphism. We also investigate some properties of right unit-duo rings which are concerned with annihilating conditions.

• 응용통계연구
• /
• 제24권1호
• /
• pp.137-143
• /
• 2011

The classification of subjects with unknown distribution in a small sample size often involves order-restricted constraints in multivariate parameter setups. Those problems make the optimality of a conventional likelihood ratio based statistical inferences not feasible. Fortunately, Roy (1953) introduced union-intersection principle(UIP) which provides an alternative avenue. Multivariate linear rank statistics along with that principle, yield a considerably appropriate robust testing procedure. Furthermore, conditionally distribution-free test based upon exact permutation theory is used to generate p-values, even in a small sample. Applications of this method are illustrated in a real microarray data example (Lobenhofer et al., 2002).

• Journal of the Korean Data and Information Science Society
• /
• 제12권1호
• /
• pp.19-25
• /
• 2001

Random effects models which describe the dependence via random effects in various correlated data have recently received considerable attention in the biomedical literature. They include mixed linear models (MLMs), generatized linear mixed models (GLMMS) and hierarchical generalized linear models (HGLMs). For the inference Lee and Nelder (2000) proposed the first-and second-order REML (restricted maximum likelihood) methods based on hierarchical-likelihood of tee and Welder (1996). In this paper, for Poisson-gamma HGLMs the new methods are theoretically compared with marginal likelihood methods and both methods are illustrated by two practical examples.

• Journal of applied mathematics & informatics
• /
• 제13권1_2호
• /
• pp.457-470
• /
• 2003

The comparison of two or more Lorenz curves of Pareto distributions of first kind under arbitrary order restriction is studied. The problem is turned out to be a statistical inference problem concerning scale parameters under order restriction. We assume that the location parameters of Palate distributions are completely unknown. In this paper the maximum likelihood estimation and likelihood ratio tests for and against order restriction are proposed.

• Journal of the Korean Statistical Society
• /
• 제25권4호
• /
• pp.489-497
• /
• 1996

Lower bounds for the full level probabilities are derived under order restrictions in weights. Discussions are made on typical isotonic cones such as linear order, simple tree order, and unimodal order cones. We also discuss applications of these results for constructing conditional likelihood ratio tests for ordered hypotheses in a contingency table. A real data set on torus mandibularis will be analyzed for illustrating the testing procedure.

• Journal of Nutrition and Health
• /
• 제2권1호
• /
• pp.35-46
• /
• 1969

임신 전(前) Restricted diet을 먹은 것과 Unrestricted diet을 먹은 group간에 2세의 체중증가에 미치는 영향에는 차이가 없었으며 임신 전(前) 체중변화에 있어서 Restricted diet에 숫컷이 더 예민하였다. 암컷에서는 Recovery diet을 주는 기간에는 Unrestricted group을 거의 쫓아 갔으나 숫컷에서는 그차이가 심하였다. 새끼들의 체중에 있어서 임신동안의 초기와 후기의 식이제한 group은 관계없이 임신전(全)기간 식이제한 group과 Unrestricted group간에 체중의 차이를 나타내었다. 어미의 Nitrogen 배설량에서 보면 섭취량에 대한 배설량의 백분율은 사료섭취량의 증감(增減)에 관계없이 일정하며 배설량은 사료섭취량이 많으면 많이 나가고 적으면 그것에 비례해서 적게 배설되었다. 새끼의 Nitrogen 배설량은 8 group사이에 큰 차이를 보여주지 않고 있다. Birth weight는 임신전(前) Restricted diet이나 Unrestricted diet 영향을 받지 않았으며 임신동안의 Unrestricted group의 새끼가 임신동안 전(全)기간 식이제한을 하였거나 부분적으로 식이제한을 한 group의 새끼보다 Birth weight가 컸다. litter size는 사료섭취량에 영향을 받지 않았다.

• 한국산학기술학회논문지
• /
• 제14권4호
• /
• pp.1896-1902
• /
• 2013

무기체계에 상용부품을 적용하는 개념인 COTS (Commercial-Off-The-Shelf)는 국방기술이 민수기술을 선도하던 시기에 크게 호응을 얻지 못했다. 그러나 IT기술의 급속한 성장과 민수산업의 빠른 확장은 짧은 시간에 저가의 대량생산 체계를 갖추게 되었고, 비용과 일정의 장점이 부각되면서 민수분야에 생산되는 부품들이 무기체계에 적용되었다. 민수기술이 국방 무기체계에 사용되기 위해서는 전투 환경의 극한 제약사항에서 성능을 보장할 수 있어야 한다. 일반적으로 상용부품은 설계 및 생산에 대한 요구조건이 군용과 비교하여 다르기 때문에 근본적인 한계가 있다. 따라서, 상용부품이 무기체계에 사용되기 위해서는 시스템공학적 접근을 통한 확인이 요구된다. 본 연구에서는 무기체계에 COTS를 적용하기 위한 방안으로 해양 무기체계 특성에 적합한 프로세스와 제약사항 분석방안을 제시하였다. 해양 무기체계의 제약사항을 일반 환경 및 특수 환경 제약사항으로 구분하고 세부적인 프로세스를 제시하였으며, 시장에서 이러한 제약사항에 적합한 제품을 선택할 때 유용한 도구를 제시하였다. 마지막으로 COTS의 해양 무기체계 적용을 위한 사례연구로 전투함 전기시스템의 COTS 적용 및 제약사항 분석 결과를 확인하였다.

• Structural Engineering and Mechanics
• /
• 제67권5호
• /
• pp.465-479
• /
• 2018

In a previous study, design charts where proposed to help the torsional design of axially restricted reinforced concrete (RC) beams with squared cross section. In this article, new design charts are proposed to cover RC beams with rectangular cross section. The influence of the height to width ratio of the cross section on the behavior of RC beams under torsion is firstly shown by using theoretical and experimental results. Next, the effective torsional strength of a reference RC beam is computed for several values and combinations of the study variables, namely: height to width ratio of the cross section, concrete compressive strength, torsional reinforcement ratio and level of the axial restraint. To compute the torsional strength, the modified Variable Angle Truss Model for axially restricted RC beams is used. Then, an extensive parametric analysis based on multivariable and nonlinear correlation analysis is performed to obtain nonlinear regression equations which allow to build the new design charts. These charts allow to correct the torsional strength in order to consider the favourable influence of the compressive axial stress that arises from the axial restraint.

• 대한산업공학회지
• /
• 제30권2호
• /
• pp.107-119
• /
• 2004

A study on the following parallel machine problem is addressed in this research. An order is completed only when a given number of processes (cycle) are repeated. Anew cycle is possible only upon the completion of the previous cycle. Orders are classified into job group according to product feature. For a machine to switch to a different job group from the currently processing one a major setup is required while a minor setup time is inserted in between two jobs of the same job group. The objective of the study is to find a schedule that minimizes total weighted tardiness. An initial solution is obtained by the RATCS(Restricted Apparent Tardiness Cost with Setup) rule, and a Tabu search is applied to improve the solution. Numerical examples are also presented.

• Communications for Statistical Applications and Methods
• /
• 제4권1호
• /
• pp.185-191
• /
• 1997

Bayesian estimation of multinomial and Poisson parameters under starshped restriction is considered. Most Bayesian estimations in order restricted statistical inference require the high-dimensional integration which is very difficult to evaluate. Monte Carlo integration and Gibbs sampling are among alternative methods. The Bayesian estimation considered in this paper requires only evaluation of incomplete beta functions which are extensively tabulated.