• 대한방사선기술학회지:방사선기술과학
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• 제25권1호
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• pp.83-88
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• 2002

This work was peformed as a basic research in the application of Monte Carlo methods for planning treatments by electron beams. Depth doses, beam profiles and isodose curves in water phantoms were calculated for monoenergetic electron beams with 6, 9, and 12 MeV. The calculated depth doses and beam profiles are almost consistent with their known values. If allowances are made for distributions in electron beam energies, we are confident that the agreement between our calculations and measured values will significantly improve. In conclusion, our work shows that similar Monte Carlo calculations could be applied for geometries In human body in planning electron beam treatments.

• 한국세라믹학회지
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• 제32권8호
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• pp.957-965
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• 1995

The ionic conductivityof NASICON solid electrolytes was simulated by using Monte Carlo Method (MCM) based on a hopping model as functions of temoperature and composition. Two conduction paths were used : jumping from Na1 to Na2 and jumping from Na1 to Na2 and jumping from Na2 to Na2. Vacancy availability factor, V was affected by composition, temperature and the conduction paths. For β"-Alumina, it was known that the minimum of charge correlation factor, fc appears at the composition, p=0.5, but there was not shown the minimum of fc for NASICON. When the NASICON composition, x, approaches 2.5, the curve of In σT vs. 1/T* was shown Arrhenius behavior and also In (VWfc) was a linear function of 1/T*. The results of simulations on the considered conduction paths didn't agree with the experimental results. Thus it will be necessary to include the another Na sites as mid-Na site on the conduction path to obtain the better results.

• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.847-850
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• 2002

Stochastic process analysis is often based on Monte Carlo simulations. As a more rigorous alternative, a deterministic algorithm based on numerical integration is proposed in this paper. which calculates the probability distributions of dependent random variables using the results of simulation with grid points of independent random variables. For performance evaluation, the proposed algorithm is applied to an example problem which can be analytically solved. and the result is compared with that of Monte Carlo simulation. The proposed algorithm is suitable for general process simulation problems with a few independent random variables, and expected to be applicable to areas such as safety analysis and quality control.

• 한국항공우주학회지
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• 제40권8호
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• pp.670-677
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• 2012

본 논문에서는 Biomorphic C/SiC 복합재료에 대하여 단위구조해석을 수행하였다. 소나무와 뉴송을 탄화하고 실리콘을 함침해 제조한 복합재료의 미세조직을 사각배열과 육각배열로 가정해 단위구조를 정의하고 등가물성치를 계산하였다. 단위구조의 크기가 동일하지 않은 경우도 고려하였고, 또한 공극의 배열에 따른 물성치의 변화를 몬테카를로 시뮬레이션을 통해 조사하였다.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.64-74
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• 2017

본 연구에서는 동역학 격자기반 대정준 Monte Carlo (Kinetic Lattice Grand Canonical Monte Carlo, KLGCMC) 모의실험 방법과 Poisson-Nernst-Planck (PNP) 계산 방법을 이용하여 이온채널의 전하분포, 채널 반지름, 그리고 이온의 농도와 이온의 크기가 이온전류와 이온전도도에 미치는 영향과, 이온 간 상관관계 (correlation)가 이온전류와 이온전도도에 미치는 영향을 조사하였다. 이로부터 이온 간 상호작용에 의해 이온 이동에 제약이 가해지는 이온 간 상관관계 효과는 채널 내 이온 수가 증가할수록 커지는 것을 알 수 있었다. 또한, 평균장 이론에 기반한 PNP 이론은 이온 간 상관관계 효과를 적절하게 기술하지 못하며, 이온 간 상관관계 효과가 중요해지는 이온 채널 관련 결맞음 공명 (coherence resonance) 등 특이 현상을 연구하기 위해서는 이온 간 상관관계를 기술할 수 있는 KLGCMC 모의실험 방법이 필요함을 알 수 있었다.

• 한국조명전기설비학회지:조명전기설비
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• 제6권2호
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• pp.37-42
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• 1992

In this paper, illuminance distribution is calculated by the Monte Carlo simulation. In comparison with other methods, it has simpler arithmetic process. Light is assumed to be of particle nature. It has particular direction taken from a random function. Paths of each particle are calculated, and the final absorbing points are found. repeating this process, the statistical illluminance distribution is determined proportional to the number of particles striking each wall. For a better result and graphic output, each wall surface was divided into many small ones.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.887-889
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• 1996

This paper presents Variance Reduction Techniques of the Monte Carlo Simulation considering Non-Exponential Distribution for Power System Reliability Evaluation. Generally, the components consisting of power system are assumed to be exponentially distributed in their state residence time. Sometimes, however, this assumption may cause a lot of errors in the reliability index evaluation. Non-exponential distribution can be approximated by a sum of several Erlangian distributions, whose inverse transform is easily calculated by using composition method. This paper proposes a new approach to deal with the non-exponential distribution and to reduce the simulation time by virtue of Variance Reduction Techniques such as Control Variate and Antithetic Variate.

• 한국조명전기설비학회지:조명전기설비
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• 제6권5호
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• pp.19-26
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• 1992

A computer program to calculate the illumination distributions of a room interior was made. The room has a light source with arbitrary intensity distribution. The program follows the paths of the particles from the light sources, and the illumination distribution is calculated by repeating this following to many particles. Monte Carlo method is applied to the decision of the direction of the particle from light source, and the new direction of the reflected particles. Making simulation program on this basis, illumination distributions were measured for various light sources and wall surfaces tocertify the calculated results. As a results, it is known that the calculated distribution would be correct if the size of the light source is sufficiently smaller than the size of the room.

• 대한화학회지
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• 제60권1호
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• pp.9-15
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• 2016

폭발성능이 높은 HMX와 폭발성능은 떨어지지만 안정성이 높은 LLM-116의 분자복합체인 HMX/LLM-116 공결정(cocrystal)의 폭발 속도, 폭발 압력 그리고 열역학적 안정성에 대하여 이론적으로 연구하였다. 각 분자 구조는 B3LYP/cc-pVTZ 수준까지 최적화 하였으며 가장 약한 방아쇠 결합(trigger bond)과 클러스터에 대한 결합에너지를 계산 하여 열역학적 안정성을 확인하였다. 보다 정확한 에너지를 계산하기 위해 MP2 이론 수준에서 한 점(single point) 에너지를 계산하였으며, monte carlo integration 계산을 통해 밀도를 계산 하였다. 엔탈피는 CBS-Q 이론 수준에서 계산하였으며, 폭발 속도와 폭발 압력은 Kamlet-Jacobs 방정식을 이용하여 계산하였다.

• 한국의학물리학회지:의학물리
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• 제22권3호
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• pp.124-130
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• 2011

본 연구에서는 생물학 연구용 방사선 조사기(Gamma Irradiator, Chiyoda Technol Co., Japan)에서 방출되는 Cs-137 감마선에 대하여 선량자료 구축을 위한 선량평가를 수행하였다. 대상 시료는 직경 3 cm인 구형의 물로 가정하였으며 공기커마로부터 선량계산 체계에 따라 흡수선량을 결정하였다. 측정값의 평가를 위하여 이론적 계산 및 몬테칼로 계산(MCNPX)을 이용하여 상호 비교하였다. 측정한 공기커마는 선원과 200 cm 이내에서 이론적 계산과 3.1% 이내로 일치하였다. 최종 결정된 흡수선량은 몬테칼로 계산과 100 cm와 200 cm에서 각각 1.9% 및 3.7%의 차이를 보였다. 본 결과는 비록 단편적이지만 생물 실험용 자료구축을 위한 기초 결과로서 타당하며 추후 다양한 형태의 시료 조건에 대해서 연구를 진행해야 할 것이다.