• Title/Summary/Keyword: monte carlo method

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A Novel Simulation Architecture of Configurational-Bias Gibbs Ensemble Monte Carlo for the Conformation of Polyelectrolytes Partitioned in Confined Spaces

  • Chun, Myung-Suk
    • Macromolecular Research
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    • v.11 no.5
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    • pp.393-397
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    • 2003
  • By applying a configurational-bias Gibbs ensemble Monte Carlo algorithm, priority simulation results regarding the conformation of non-dilute polyelectrolytes in solvents are obtained. Solutions of freely-jointed chains are considered, and a new method termed strandwise configurational-bias sampling is developed so as to effectively overcome a difficulty on the transfer of polymer chains. The structure factors of polyelectrolytes in the bulk as well as in the confined space are estimated with variations of the polymer charge density.

Evaluation of Target Failure Level on Sliding Mode of Vertical Breakwaters using Safety Factors (안전율을 이용한 직립 방파제의 활동에 대한 목표파괴수준 산정)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.2
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    • pp.112-119
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    • 2010
  • A Monte-Carlo simulation method is proposed which can evaluate the target failure/safety levels on any failure modes of harbor structures as a function of central safety factor. Unlike the calibration method based on the average safety level of conventional design criteria, the target failure/safety level can be directly evaluated by only using central safety factors of the harbor structures which have been designed by safety factor method during the past several decade years. Several mathematical relationships are represented to straightforwardly connect the conventional safety factor design method with reliability-based design method. Even though limited data have been used in applying Monte-Carlo simulation method to sliding failure mode of the vertical breakwaters, it is found that target reliability indices evaluated by the suggested method in this paper is satisfactorily agreement with new criteria of reliability index of Japan.

Collision Risk Assessment for Pedestrians' Safety Using Neural Network (신경 회로망을 이용한 보행자와의 충돌 위험 판단 방법)

  • Kim, Beom-Seong;Park, Seong-Keun;Choi, Bae-Hoon;Kim, Eun-Tai;Lee, Hee-Jin;Kang, Hyung-Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.1
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    • pp.6-11
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    • 2011
  • This paper proposes a new collision risk assessment system for pedestrians's safety. Monte Carlo Simulation (MCS) method is a one of the most popular method that rely on repeated random sampling to compute their result, and this method is also proper to get the results when it is unfeasible or impossible to compute an exact result. Nevertheless its advantages, it spends much time to calculate the result of some situation, we apply not only MCS but also Neural Networks in this problem. By Monte carlo method, we make some sample data for input of neural networks and by using this data, neural networks can be trained for computing collision probability of whole area where can be measured by sensors. By using this trained networks, we can estimate the collision probability at each positions and velocities with high speed and low error rate. Computer simulations will be shown the validity of our proposed method.

Investigation of the existing thermal noise theories for field-effect transistors using the monte-carlo method and the generalized ramo-shockley theorem (Monte-carlo 방법과 일반화된 ramo-shockley 정리를 통한 FET 열잡음 이론의 검증)

  • 모경구;민홍식;박영준
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.10
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    • pp.107-114
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    • 1996
  • Monte carlo method is especially a useful method for the analysis of thermal noise of semiconductor devices since the time dependence of microscopic details is simulated directly. Recently, a mthod for the calculation of the instantaneous currents of 2-dimensional devices, which is numerically more accurate than the conventional method, has been proposed using the generalized ramo-shockley theorem. Using this mehtod we investage the validity of the existing thermal noise theories of field-effect transistors. First, the 1-dimensional analysis of thermal noise theories of field-effect transistors. First, the 1-dimensional analysis of thermal noise theories of field-effect transistors. First, the 1-dimensional analysis of thermal noise using ramo-shockley theorem is shown to be applicable to 2 dimensional devices if the frequency of interest is low enough. The correlation between electrons in different regions of th echannel is shown not to be negligible. And we also obtian the spatial map of the noise in the channel region. By doing so, we show that the steady state nyquist theorem is the correct theory rather than the theory by van der ziel et.al.

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A Procedure for Statistical Thermal Margin Analysis Using Response Surface Method and Monte Carlo Technique (반응 표면 및 Monte Carlo 방법을 이용한 통계적 열여유도 분석 방법)

  • Hyun Koon Kim;Young Whan Lee;Tae Woon Kim;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.18 no.1
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    • pp.38-47
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    • 1986
  • A statistical procedure, which uses response surface method and Monte Carlo simulation technique, is proposed for analyzing the thermal margin of light water reactor core. The statistical thermal margin analysis method performs the best.estimate thermal margin evaluation by the probabilistic treatment of uncertainties of input parameters. This methodology is applied to KNU-1 core thermal margin analysis under the steady state nominal operating condition. Also discussed are the comparisons with conventional deterministic method and Improved Thermal Design Procedure of Westinghouse. It is deduced from this study that the response surface method is useful for performing the statistical thermal margin analysis and that thermal margin improvement is assured through this procedure.

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Estimation of Incoherent Scattered Field by Multiple Scatterers in Random Media

  • Seo, Dong-Wook;Lee, Jae-Ho;Lee, Hyung Soo
    • ETRI Journal
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    • v.38 no.1
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    • pp.141-148
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    • 2016
  • This paper proposes a method to estimate directly the incoherent scattered intensity and radar cross section (RCS) from the effective permittivity of a random media. The proposed method is derived from the original concept of incoherent scattering. The incoherent scattered field is expressed as a simple formula. Therefore, to reduce computation time, the proposed method can estimate the incoherent scattered intensity and RCS of a random media. To verify the potential of the proposed method for the desired applications, we conducted a Monte-Carlo analysis using the method of moments; we characterized the accuracy of the proposed method using the normalized mean square error (NMSE). In addition, several medium parameters, such as the density of scatterers and analysis volume, were studied to understand their effect on the scattering characteristics of a random media. The results of the Monte-Carlo analysis show good agreement with those of the proposed method, and the NMSE values of the proposed method and Monte-Carlo analysis are relatively small at less than 0.05.

Development of a Method for Uncertainty Analysis in the Top Event Unavailability (고장수목 정점사상 이용 불능도의 불확실성 분석용 방법 개발)

  • Sang Hoon Han;Chang Hyun Chung;Kun Joong Yoo
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.97-105
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    • 1984
  • A method and computer code for the uncertainty analysis in the top event unavailability are developed and tested by combining Monte Carlo Method and Moments method with fault tree reduction technique. Using system fault trees and unavailability data selected in WASH-1400, the efficiency of the proposed method is tested and these results are compared with those obtained by Monte Carlo method. It is shown that the results are sufficiently good in accuracy and computation time is considerably reduced compared with those by Monte Carlo method.

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Vibration of Non-linear System under Random Parametric Excitations by Probabilistic Method (불규칙 매개변수 가진을 받는 비선형계의 확률론적 진동평가)

  • Lee, Sin-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.12 s.189
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    • pp.72-79
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    • 2006
  • Vibration of a non-linear system under random parametric excitations was evaluated by probabilistic methods. The non-linear characteristic terms of a system structure were quasi-linearized and excitation terms were remained as they were An analytical method where the square mean of error was minimized was used An alternative method was an energy method where the damping energy and restoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

Quasi-linearization of non-linear systems under random vibration by probablistic method (확률론 방법에 의한 불규칙 진동 비선형 계의 준선형화)

  • Lee, Sin-Young;Cai, G.Q.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.785-790
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    • 2008
  • Vibration of a non-linear system under random parametric excitations was evaluated by probablistic methods. The non-linear characteristic terms of a system were quasi-linearized and excitation terms were remained as they were given. An analytical method where the square mean of error was minimized was ysed. An alternative method was an energy method where the damping energy and rstoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

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On Estimation of HPD Interval for the Generalized Variance Using a Weighted Monte Carlo Method

  • Kim, Hea-Jung
    • Communications for Statistical Applications and Methods
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    • v.9 no.2
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    • pp.305-313
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    • 2002
  • Regarding to inference about a scalar measure of internal scatter of Ρ-variate normal population, this paper considers an interval estimation of the generalized variance, │$\Sigma$│. Due to complicate sampling distribution, fully parametric frequentist approach for the interval estimation is not available and thus Bayesian method is pursued to calculate the highest probability density (HPD) interval for the generalized variance. It is seen that the marginal posterior distribution of the generalized variance is intractable, and hence a weighted Monte Carlo method, a variant of Chen and Shao (1999) method, is developed to calculate the HPD interval of the generalized variance. Necessary theories involved in the method and computation are provided. Finally, a simulation study is given to illustrate and examine the proposed method.