• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2003년도 추계학술대회
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• pp.49-56
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• 2003

When X and Y have independent normal distributions, we develop a Bayesian testing procedure for the equality of two coefficients of variation. Under the reference prior of the coefficient of variation, we propose a Bayesian test procedure for the equality of two coefficients of variation using fractional Bayes factor. A real data example is provided.

• Journal of the Korean Data and Information Science Society
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• 제14권4호
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• pp.1023-1030
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• 2003

When X and Y have independent normal distributions, we develop a Bayesian testing procedure for the equality of two coefficients of variation. Under the reference prior of the coefficient of variation, we propose a Bayesian test procedure for the equality of two coefficients of variation using fractional Bayes factor. A real data example is provided.

• Journal of the Korean Statistical Society
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• 제32권2호
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• pp.93-101
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• 2003

This paper deals with testing the equality of the coefficients of variation in two inverse Gaussian populations. The likelihood ratio, Lagrange-multiplier and Wald tests are presented. Monte-Carlo simulations are performed to compare the powers of these tests. In a simulation study, the likelihood ratio test appears to be consistently more powerful than the Lagrange-multiplier and Wald tests when sample size is small. The powers of all the tests tend to be similar when sample size increases.

• 제어로봇시스템학회논문지
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• 제14권3호
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• pp.295-300
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• 2008

In this paper, a new looper controller is proposed to minimize the tension variation of a strip in the hot strip finishing mill. The proposed control technology is based on a receding horizon control (RHC) to satisfy the constraints on the control input/state variables. The finite terminal weighting matrix is used instead of the terminal equality constraint. The closed loop stability of the RHC for the looper system is analyzed to guarantee the monotonicity of the optimal cost. Furthermore, the RHC is combined with a 4SID(Subspace-based State Space System Identification) model identifier to improve the robustness for the parameter variation and the disturbance of an actuator. As a result, it is shown through a computer simulation that the proposed control scheme satisfies the given constraints on the control inputs and states: roll speed, looper current, unit tension, and looper angle. The control scheme also diminishes the tension variation for the parameter variation and the disturbance as well.

• 대한교통학회지
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• 제20권4호
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• pp.135-150
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• 2002

기 제안된 수리적 동적통행배정모형은 전체 시뮬레이션 기간동안 시간종속적 교통수요와 교통망의 교통상황이 이미 안정되어 있고 장래에도 예측가능 하다는 가정을 전제로 개발되었다. 이러한 가정은 실제 시시각각으로 변화하는 교통수요와 교통상황의 예측 불가능함 고려할 때 비현실적이라고 할 수 있다. 한편, Rolling Horizon Implementation(RHI)은 기종점간의 수요행렬(trip matrix)과 교통상황(traffic condition)이 단기간의 예측시간동안 현재의 예측정보를 기반으로 신뢰성 있게 모니터링 될 수 있고, 그 시점에서 보다 미래로 연장된 시간으로는 불확실성(uncertainty)의 증가를 고려한다는 가정을 전제로 제안되었다. 따라서, RHI개념과 부합되는 수리적 동적통행배정모형은 시뮬레이션 출발시점에 수요와 교통상황에 대한 확정적 정보가 이미 획득되어 있고, 그 기간이후의 정보에 대해서는 시간이 흐름에 따른 정보의 유용성을 근거로 각 운전자 그룹이 인지 (Perceived)하는 가로망의 통행비용(travel cost)을 최소화되도록 차량을 배정하는 것으로, 실시간적으로 인지된 교통수요와 교통망에 대한 정보를 통행배정초기에 입력변수로 사용하여 실시간 교통정보모형으로서 운영가능 하다는 장점을 제공한다. 본 연구는 수리적 동적통행배정모형이 RHI개념과 부합되어 교통상황과 수요변화를 실시간적으로 반영하여 운영되도록 모형의 기능을 확장하는 데 있다. 이를 위해, 다계층 이용자(multiple user classes) 동적통행배정모형을 변동등식(variational equality)이론에 근거한 모형식을 기반으로, 실시간 통행배정에서 발생하는 종점에 도착하지 못한 차량(unfinished trips)과 이들의 재배정(rerouting strategy) 문제를 인식하고, 이 차량들을 링크상의 교통량 전파조건(flow propagation constraint)을 토대로 다음 통행배정 시간대의 실시간 수요로서 반영할 수 있는 방안을 제시한다.

• 의정연구
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• 제24권1호
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• pp.241-276
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• 2018

본 논문은 제4~6회 시 도의회의원 선거의 표의 등가성을 새로운 지수를 활용하여 측정한다. 본 연구에서 표의 등가성 측정을 위해 사용되는 코사인제곱지수는 계산의 편리성과 더불어 광역시 도 단위로 선거구획정이 이루어지는 시 도의회의원 선거에서 지역 내 인구동등성 정도를 파악하는 데 그 유용성이 크다. 경험적 분석 결과, 제4회 시 도의회의원 선거는 인구수 규모와 상관없이 자치구 시 군마다 일률적으로 2인의 의원을 선출함에 따라 선거구간 인구편차가 지나치게 커지면서 지역 내 인구동등성 정도가 낮게 나타났다. 이후 2007년 헌법재판소의 결정으로 2010년 제5회 시 도의회의원 선거부터는 인구편차 기준이 4:1로 강화됨에 따라 표의 등가성이 대폭 증가함을 알 수 있었다. 그러나 한편으로는 여러 선거에 걸쳐 농촌지역 선거구의 인구수 불균형문제, 도농 간의 과소 과다대표 문제가 지속되고 있음도 동시에 확인할 수 있었다. 이 연구는 지방의회 선거의 선거구획정이 인구대표성 같은 물리적 비교를 바탕으로 하는 획일적인 방식을 지양하고 다양한 기준과 지역의 동질적 가치를 반영하는 방향으로 이루어져야 한다는 점을 강조하며, 이에 대한 시론적 방안을 제시한다.

• 대한치과보철학회지
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• 제42권4호
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• pp.443-457
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• 2004

Purpose: The purpose of this study was to analyze and estimate whether each company may produce the color of artificial teeth as it stands, in the standard of vita classical shade guide using ShadeScan$^{TM}$ System. Material and methods: we chose the products of 6 companies -EFUCERA, IVOCLAR, ENDURA, TRUBYTE, DURADENT, and DURACROSS- estimated the shade value of each fixed point(cervical, body, and incisal area) of artificial tooth, and verified the equality among the samples from the same company. Results: First, the variation appeared significant at cervical and incisal area. It means that there were significant differences between cervical and incisal area although the most similar artificial teeth to the patients’natural teeth were provided. Second, the results in the body area showed that the variation between artificial and natural teeth was finite(p<0.05) in that area. Conclusion: it shows that the reproduction of colors of artificial teeth might be successful regarding the body is the most important part for a determination of the color of artificial teeth. However, more complements are necessary for the better reproduction of the color of artificial teeth between cervical and incisal area.

• 보건행정학회지
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• 제30권1호
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• pp.100-111
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• 2020

Background: Few studies have examined the performance of the public long-term care insurance (LTCI) from the perspective of geographic equity. This study investigated regional variations and associated factors in the supply and utilization of nursing home care within and also between Japan and Korea. Methods: A comparative dataset was developed by extracting data from 2013-2015 LTCI statistics yearbooks and Organization for Economic Cooperation and Development regional statistics, as well as other comparable data in Japan and Korea. The unit of analysis was the prefecture in Japan and the province in Korea. We computed variation indices and conducted regression analyses for regional variations within each country and decomposition analyses to examine the variations between the countries. Results: The overall regional supply and use of nursing home care were higher in Japan, but the regional variations in Korea were larger than in Japan. In both countries, the nursing home supply was negatively associated with the proportion of older people with independent living. Nursing home use was also negatively associated with the supply of hospital beds and home care agencies in Korea; the relationship was the opposite in Japan, however. The country-based differences were more likely to be explained by differences in the distributions of the variables included in the analytical model than country-specific characteristics. Conclusion: Regional-level nursing home supply and use were unequal in both countries, and the contributing factors were not the same. Policy efforts are needed to advance regional equality in long-term care (LTC) and collaboration between health and LTC institutions for frail older people, especially in Korea.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.263-268
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• 2008

In a residential complex case, the efficiency of land use are maximized, but a variation of external condition such as load in-equality, the increase in wind velocity and solar radiation by a height causes increasing energy in a building. Besides, because of increasing window size for a lighting and a view, it comes heating load in winter and cooling load in summer. A choice of cooling-system is important for this reason. Recently an internal high-rise residential complex installs an air-cooling system and operates individual heating. However, this study applies water-cooling used one public cooling-tower instead of an air-cooling system, also with an efficiency test of an air and a water-cooling system, consider an internal applicability.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.182-189
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• 1996

The focus of this study is on the problem of the design of structure of undetermined topology. This problem has been regarded as being the most challenging of structural optimization problems, because of the difficulty of allowing topology to change. Conventional approaches break down when element sizes approach to zero, due to stiffness matrix singularity. In this study, a novel nonlinear Programming formulation of the topology Problem is developed and examined. Its main feature is the ability to account for topology variation through zero element sizes. Stiffness matrix singularity is avoided by embedding the equilibrium equations as equality constraints in the optimization problem. Although the formulation is general, two dimensional plane elasticity examples are presented. The design problem is to find minimum weight of a plane structure of fixed geometry but variable topology, subject to constraints on stress and displacement. Variables are thicknesses of finite elements, and are permitted to assume zero sizes. The examples demonstrate that the formulation is effective for finding at least a locally minimal weight.