• Journal of the Korean Data and Information Science Society
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• v.25 no.2
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• pp.465-472
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• 2014

This article deals with the problem of testing the equality of the scale parameters in the half logistic distributions. We propose Bayesian hypothesis testing procedures for the equality of the scale parameters under the noninformative priors. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be dened up to a multiplicative constant. Thus we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• v.24 no.3
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• pp.643-650
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• 2013

We develop noninformative priors for a ratio of parameters of two Maxwell distributions which is used to check the equality of two Maxwell distributions. Specially, we focus on developing probability matching priors and Je reys' prior for objectiv Bayesian inferences. The probability matching priors, under which the probability of the Bayesian credible interval matches the frequentist probability asymptotically, are developed. The posterior propriety under the developed priors will be shown. Some simulations are performed for identifying the usefulness of proposed priors in objective Bayesian inference.

• Journal of Industrial Technology
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• v.19
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• pp.115-125
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• 1999

Current design and analyzing methods about soil nailing structures, developed on the basis of results obtained from experiments in laboratory or in field and numerical analyses, have applied different interaction mechanisms between the reinforced nails and the surrounding ground, and this different safety factors against failure have been obtained. They might be proper approached if the assumptions about rigidity of nails and ground conditions are met with actual conditions occurred in field. Otherwise, they would result in designing on analyzing in inappropriate ways so that it is needed to evaluate the validity of them. Therefore, overall behavior and failure mechanism about soil nailing system were investigated by performing numerical method. Using a finite element analysis, parametric studies were made to examine the importance of the various parameters and their effects on the soil nailing system. The numerical technique of FEM, implemented with Hyperbolic constitutive model, was also used to analyze the test results.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.232-234
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• 2004

Tilting train has been developed to increase the operational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper developed tilting control simulator to evaluate tilting control performance of TTX(tilting train express) with maximum operation speed 180 km/h.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.231-232
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• 2008

It's essential to evaluate harmonic characteristics of electric train because harmonics have negative effects on a main circuit of electric train, substations and communication system. So, we measured harmonics of electric train during test operating on conservational railroad, In the result, we can know relation between operation mode(acceleration, breaking operation and uniform speed operation) and harmonics.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1545-1546
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• 2015

본 연구에서는 아직은 우리 주변에서 생소하지만 향후 사용 빈도가 높아질 중앙 집진식 청소기의 발생 가능한 화재원인을 연구하여 어떤 조건하에서 발화가능성이 있는지, 발화요인 제거와 화재조사시 과학적으로 명확하게 판단하여 원인불명의 화재가 발생하지 않도록 중앙 집진식 청소기의 화재 감식기법과 예방을 위한 개선방향을 제시하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.7 s.238
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• pp.990-997
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• 2005

The objective of this paper is to present the element connectivity parameterization (ECP) fur three dimensional problems. In the ECP method, a continuum structure is viewed as discretized finite elements connected by zero-length elastic links whose stiffness values control the degree of inter-element connectivity. The ECP method can effectively avoid the formation of the low-density unstable elements. These elements appear when the standard element density method is used for geometrical nonlinear problems. In this paper, this ECP method developed fur two-dimensional problems is expanded to the design of three-dimensional geometrical nonlinear structures. Among others, the automatic procedure converting standard finite element models to the models suitable for the ECP approach is developed and applied for optimization problems defined on general three-dimensional design domains.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.779-785
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• 2009

This paper is concerned with a computational approach for topology optimization of geometrically nonlinear structures following specific load-displacement trajectories. In our previous works, attention was paid to stabilize topology optimization involving large displacement and a method called the element connectivity parameterization was developed. Here, we aimed to extend the element connectivity parameterization method to find an optimal geometrically nonlinear structure yielding a specific load-displacement trajectory. In contrast to designing a stiffest structure, the trajectory design problem requires special consideration in topology optimization formulation and solution procedure. Some numerical problems were considered to test the developed element connectivity parameterization based formulation.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.451-451
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• 2011

홍수피해경감편익 가운데 직접편익 항목은 크게 일반자산피해액, 인적피해액, 공공시설물피해액으로 구분되며, 이 가운데 공공시설물피해액은 현재까지 국내실정을 고려하지 않은 일본수치를 그대로 차용하여 실제 적용시 해당지역의 규모, 특성을 무시한 채 평가되어 왔다. 이러한 공공시설물 홍수피해액은 전체 피해액에서 차지하는 비율이 상대적으로 매우 크고, 해당지역의 개발정도에 따라 피해정도가 상이할 수 있기 때문에, 이에 대한 보다 실증적이고 합리적인 접근이 필요하다. 그리하여 본 연구에서는 국내 실정에 적합하고 지역특성을 실제적으로 고려한 공공시설물피해액을 산정하기 위한 방안을 모색하였다. 이를 위해 본 연구에서 고려하는 공공시설물을 재정의하였고, 피해특성 및 양상에 따라 침수심 예민 공공시설물과 침수심 비예민 공공시설물로 분류하여 각각에 대한 분석절차를 제시하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.109-113
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• 2011

수자원사업은 합리적이고 신뢰성 있는 의사결정이 필요한데 그동안 주로 경제성분석에 의존하여 왔다. 본 연구는 경제성분석위주의 기존 방법을 탈피하여 사업 필요성과 투자 타당성을 다양한 각도로 평가할 수 있는 합리적이고 객관적인 수자원사업 대안선정과 투자우선순위결정 방법을 도출하고자 하였다. 이를 위해, 대안 간에 동일한 기준으로 종합평가점수를 산정하여 우선순위를 결정할 수 있도록 다기준의사결정모형을 개발하였다. 적용결과는 취약성 기준에 큰 영향을 받으며, 정책적 기준, 경제성 기준의 순으로 분석되었다. 이는 전문가 설문에 의한 평가기준별 가중치의 영향으로, 수자원사업은 단순히 경제성 분석만으로 평가를 해서는 안 됨을 의미한다. 본 연구는 대규모의 예산이 투입되는 수자원사업에 대한 효율성과 취약지역에 대한 형평성을 제고하는데 기여할 수 있을 것으로 판단된다.