• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.883-889
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• 2013

The distribution of a response usually depends on the distribution of a variable. When the distribution of a variable has two different modes, the response also follows a distribution with two different modes. In most reliability analysis methods, the number of modes is irrelevant, but not the type of distribution. However, in actual problems, because information is often provided with two or more modes, it is important to estimate the distributions with two or more modes. Recently, some reliability analysis methods have been suggested for bimodal distributions. In this paper, we review some methods such as the Akaike information criterion (AIC) and maximum entropy principle (MEP) and compare them with the Monte Carlo simulation (MCS) using mathematical examples with two different modes.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.4
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• pp.335-345
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• 2008

In this study, we suggest a stochastic finite element scheme for the probabilistic analysis of the composite laminated plates, which have been applied to variety of mechanical structures due to their high strength to weight ratios. The applied concept in the formulation is the weighted integral method, which has been shown to give the most accurate results among others. We take into account the elastic modulus and in-plane shear modulus as random. For individual random parameters, independent stochastic field functions are assumed, and the effect of these random parameters on the response are estimated based on the exponentially varying auto- and cross-correlation functions. Based on example analyses, we suggest that composite plates show a less coefficient of variation than plates of isotropic and orthotropic materials. For the validation of the proposed scheme, Monte Carlo analysis is also performed, and the results are compared with each other.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.535-536
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• 2006

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.37-44
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• 1999

This paper report the implementation results of Monte Carlo numerical calculation for ion distributions in plasma dry etching chamber and of the surface evolution simulator using cell removal method for topographical evolution of the surface exposed to etching ion. The energy and angular distributions of ion across the plasma sheath were calculated by MC(Monte Carlo) algorithm. High performance MPP(Massively Parallel Processing) algorithm developed in this paper enables efficient parallel and distributed simulation with an efficiency of more than 95% and speedup of 16 with 16 processors. Parallelization of surface evolution simulator based on cell removal method reduces simulation time dramatically to 15 minutes and increases capability of simulation required enormous memory size of 600Mb.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.359-367
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• 1997

소프트웨어 개발 수명주기 동안의 소프트웨어 테스팅 단계에서 Jelinski와 Moranda의 소프트웨어 고장 데이트 해석 모형이, 병행처리 소프트웨어 환경에서 나타날 수 있는 여러 개의 소프트웨어 오류가 각 테스팅 스테이지에서 다중적으로 발생하여 하나의 소 프트웨어 고장의 원인이 되는 소프트웨어 테스팅 환경에서는 적절하지 않기 때문에, 다중 소프트웨어 오류가 하나의 고장을 유발하는 테스팅 데이터 해석을 위한 베이지안 소프트웨 어 신뢰도 성장 모형을 제안하면서 몇 가지 소프트웨어 신뢰성 측도들에 관해서 비정도 사 전정보를 고려한 베이즈 추정량을 구한다. 그리고 제안된 베이지안 소프트웨어 신뢰도 측도 들의 베이즈 추정량의 성능 평가를 위해서 몬테카를로 시뮬레이션을 수행하고 MSE와 Bias 의 관점에서 성능을 비교한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.187-197
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• 1994

오늘날 소비자의 요구가 다양해지면서 여러 개의 복잡한 부품들로 이루어진 제품이 많아지게 되었다. 각각의 부품들의 공차가 제대로 결정되지 못함으로 해서 완성된 조립품의 품질이 예상외로 나빠지는 경우가 종종있다. 본 연구는 각각의 부품들의 치수 공차와 생산 공정에서 생길 수 있는 오차들을 모두 포함시켜서 완성된 조립품의 품질을 예상할 수 있는 정확한 공차 해석 방법에 대해서 연구한다. 그 방법으로 몬테카를로 시뮬레이션 방법을 소개하고 그것에 대해서 연구한다. 본 연구를 통해서 완성된 조립품의 품질 및 성능을 저하시키는 요인을 효율적으로 결정할 수 있게 된다.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.4
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• pp.387-394
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• 2015

We analyze heat generation as well as temperature distribution induced by accelerated electron impact on a target in a closed x-ray tube. For the sake of accuracy, we use Monte carlo analysis. This method gives accurate energy deposit in a medium with additional information such as secondary and backscattered electron as well as their paths. A Tungsten coated layer is divided by small rectangular cell which accumulate energy loss of primary electron beam. The cells and their accumulated energy datum are used for the input of finite element analysis. The Maximum temperature rising and temperature distribution were analyzed by transient heat analysis. Some temperature parameters such as target size and coating thickness were varied to investigate temperature sensitivity. Temperatures were compared each other to find primary variable that affect temperature rising on the x-ray target. The results will be helpful in development highresolution x-ray tube and related industries.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.7
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• pp.657-664
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• 2011

This study proposes an inverse method for estimating the boundary temperature in a gas-filled, onedimensional parallel domain enclosed by parallel plates. The distance between the plates is considered submicron to one mm. In the current method, it is assumed that the conditions of both heat flux and temperature are simultaneously applicable to one boundary, while no conditions are applicable to the other boundary The temperature on one of the boundaries should be inversely determined from the known temperature and heat flux on the other boundary. This study proposes a procedure for estimating the unknown boundary temperature through Monte Carlo simulation. Both the forward and inverse problems employ the Monte Carlo approach. The forward (direct) problem is solved by using the direct simulation Monte Carlo while the inverse solution is obtained by the simulated annealing.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.199-206
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• 2014

In this paper, a scheme to evaluate the response variability for functionally graded material (FGM) beam with varying sectional area is presented. The randomness is assumed to appear in a spatial domain along the beam axis in the elastic modulus. The functionally graded material categorized as composite materials, however without the drawbacks of delamination and occurrence of cracks due to abrupt change in material properties between layers in the conventional composite materials. The functionally graded material is produced by the gradual solidification through thickness direction, which endows continuous variation of material properties, which makes this material performs in a smooth way. However, due to difficulties in tailoring the gradients, to have uncertainty in material properties is unavoidable. The elastic modulus at the center section is assumed to be random in the spatial domain along the beam axis. Introducing random variables, defined in terms of stochastic integration, the first and second moments of responses are evaluated. The proposed scheme is verified by using the Monte Carlo simulation based on the random samples generated employing the spectral representation scheme. The response variability as a function of correlation distance, the effects of material and geometrical parameters on the response variability are investigated in detail. The efficiency of the proposed scheme is also addressed by comparing the analysis time of the proposed scheme and MCS.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.477-488
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• 2000

A distance measure between two Latin-hypercube designs is defined and its expected value is computed. It was computed by using mathematical statistics, numerical analysis (multidimensional numerical integration), Monte-carlo method, and the theory of asymptotic normal distribution. For the comparison of two Latin-hypercube designs with same structure but different randomness, the difference of expected values of response function and information mass of experimental designs are considered. These methods may be useful in comparison between two general experimental designs.