• Title/Summary/Keyword: Method of simulated

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Optimization of Satellite Structures by Simulated Annealing (시뮬레이티드 어닐링에 의한 인공위성 구조체 최적화)

  • Im Jongbin;Ji Sang-Hyun;Park Jungsun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.2 s.233
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    • pp.262-269
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    • 2005
  • Optimization of a satellite structure under severe space launching environments is performed considering various design constraints. Simulate annealing, one of combinatorial optimization techniques, is used to optimize the satellite. The optimization results by the simulated annealing are compared to those by the method of modified feasible direction and genetic algorithm. Ten bar truss structure is optimized for feasibility study of the simulated annealing. Finally, the satellite structure is optimized by the simulated annealing algorithm under space environment. Weights of the satellite upper platform and propulsion module are minimized with consideration of several static and dynamic constraints. MSC/NASTRAN is used to find the static and dynamic responses. Simulated annealing has been programmed and integrated with the finite element analysis program for optimization. It is shown that the simulated annealing algorithm can be extended to the optimization of space structures.

Inversion of Geophysical Data via Simulated Annealing (아닐링법에 의한 지구물리자료의 역산)

  • Kim, Hee Joon
    • Economic and Environmental Geology
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    • v.28 no.3
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    • pp.305-309
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    • 1995
  • There is a deep and useful connection between thermodynamics (the behavior of systems with many degrees of freedom in thermal equilibrium at a finite temperature) and combinational or continuous optimization (finding the minimum of a given multiparameter function). At the heart of the method of simulated annealing is an analogy with the way that liquids freeze and crystallize, or metals cool and anneal. This paper provides a detailed description of simulated annealing. Although computationaly intensive, when it is carefully implemented, simulated annealing is found to give superior results to more traditional methods of nonlinear optimization.

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Optimization Using Gnetic Algorithms and Simulated Annealing (유전자 기법과 시뮬레이티드 어닐링을 이용한 최적화)

  • Park, Jung-Sun;Ryu, Mi-Ran
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.939-944
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    • 2001
  • Genetic algorithm is modelled on natural evolution and simulated annealing is based on the simulation of thermal annealing. Both genetic algorithm and simulated annealing are stochastic method. So they can find global optimum values. For compare efficiency of SA and GA's, some function value was maximized. In the result, that was a little better than GA's.

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A Study on Simulated Annealing Algorithm in Flowshop Scheduling (Flowshop 일정계획을 위한 Simulated Annealing 알고리듬 이용)

  • 우훈식;임동순;김철한
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.45
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    • pp.25-32
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    • 1998
  • A modified simulated annealing algorithm is proposed and applied to the permutation flowshop scheduling with the makespan objective. Based on the job deletion and insertion method, a newly defined Max-min perturbation scheme is proposed to obtain a better candidate solution in the simulated annealing process. The simulation experiments are conducted to evaluate the effectiveness of the proposed algorithm against the existing heuristics and results are reported.

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Proposal of a Simulated Test Method for the Evaluation of Deformation and Failure Characteristics of Pipe Elbows under Cyclic Loads (반복하중 하의 엘보우 변형 및 손상 특성 평가를 위한 모사시험 방법 제안)

  • Kim, Jin Weon;Lee, Dae Young;Park, Heung Bae
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.1
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    • pp.1-10
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    • 2020
  • This study proposed a simulated test method using ring specimen to evaluate the deformation and failure characteristics of pipe elbows under a large amplitude cyclic load. The validity of the test method was demonstrated by finite element (FE) analysis of pipe elbow and ring specimen under cyclic loads. The results showed that the proposed test method adequately simulates the distribution of circumferential strain at crown of pipe elbows where cracks occur under cyclic loads and presents the cyclic hardening behavior of pipe elbows. The parametric FE analysis showed that consistent simulated test results could be obtained when the test section of the ring specimen is longer than 1/2 of the inner diameter of the ring specimen and the radius of the inner loading jig is less than 1/4 of the inner diameter of the specimen.

Identification of the Jiles-Atherton Model Parameters Using Simulated Annealing Method

  • Bai, Baodong;Wang, Jiayin
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.18-22
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    • 2012
  • This paper presents a method and the experimental measurement system for the determination of Jiles-Atherton model parameters of the 30ZH120 electrical steel sheet. The paper utilizes Epstein Square devices to proceed with the experiment and measurement on a group of hysteresis loops of some certain transformers which use the 30ZH120 electrical steel sheet under two different lap ways. The approach relies on the simulated annealing optimization method in order to minimize the error between the measured and modeled hysteresis curves and yield the best five Jiles-Atherton model parameters. A convenient program, based on the Simulink platform, that can identify the J-A model parameters automatically from the experimental saturated hysteresis loop which is used to model the nonlinear characteristics of the electrical steel sheet, is developed. Research shows that the simulated annealing optimization method gets satisfactory results.

Preliminary strong ground motion simulation at seismic stations within nuclear power plant sites in South Korea by a scenario earthquake on the causative fault of 2016 Gyeongju earthquake

  • Choi, Hoseon
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2529-2539
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    • 2022
  • Stochastic and an empirical Green's function (EGF) methods are preliminarily applied to simulate strong ground motions (SGMs) at seismic stations within nuclear power plant (NPP) sites in South Korea by an assumed large earthquake with MW6.5 (scenario earthquake) on the causative fault of the 2016 Gyeongju earthquake with MW5.5 (mainshock). In the stochastic method, a ratio of spectral amplitudes of observed and simulated waveforms for the mainshock is assumed to be an adjustment factor. In the EGF method, SGMs by the mainshock are simulated assuming SGMs by the 2016 Gyeongju earthquake with MW5.0 (foreshock) as the EGF. To simulate SGMs by the scenario earthquake, a ratio of fault length to width is assumed to be 2:1 in the stochastic method, and SGMs by the mainshock are assumed to be EGF in the EGF method. The results are similar based on a bias of the simulated response spectra by the two methods, and the simulated response spectra by the two methods exceeded commonly standard design response spectra anchored at 0.3 g of NPP sites slightly at a frequency band above 4 Hz, but considerable attention to interpretation is required since it is an indirect comparison.

Synthesis of binary phase computer generated hologram by usngin an efficient simulated annealing algorithm (효율적인 Simulated Annealing 알고리듬을 이용한 이진 위상 컴퓨터형성 홀로그램의 합성)

  • 김철수;김동호;김정우;배장근;이재곤;김수중
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.2
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    • pp.111-119
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    • 1995
  • In this paper, we propose an efficient SA(simulated annealing) algorithm for the synthesis of binary phase computer generated hologram. SA algorithm is a method to find the optimal solution through iterative technique. It is important that selecting cost function and parameters within this algorithm. The aplications of converentional SA algorithm to synthesize parameters within this algorithm. The applications of conventional SA algorithm to synthesize binary hologram have many problems because of inappropriate paramters and cost function. So, we propose a new cost function and a calculation technique of proper parameters required to achieve the optimal solution. Computer simulation results show that the proposed method is better than conventional method in terms of diffraction efficiency and reconstruction error. Also, we show the reconstructed images by the proposed method through optical esperiment.

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A Study on Determination of Starting Temperature for the Method of Simulated Annealing (Simulated Annealing법의 적용시 Starting Temperature 결정에 관한 연구)

  • Lee, Young-Jin;Lee, Kwon-Soon
    • Proceedings of the KIEE Conference
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    • 1992.07a
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    • pp.288-289
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    • 1992
  • The method of simulated annealing is a technique that has recently attracted significant attention as suitable for optimization problem of very large scale. If the temperature is too high, then some of the structure created by the heuristic will be destroyed and unnecessary extra work will be done. If it is too low then solution is lost, similar to the case of a quenching cooling schedule in the Simulated Annealing (SA) phase. Therefore, a crucial issue in this study is the determination of the starting temperature and cooling schedule for SA phase.

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Numerical Simulationof Plaster Casting with Pressurized Vibration (진동을 부가한 저압의 석고주조 공정 해석)

  • Kim, Gi-Don;Yang, Dong-Yeol;Jeong, Jun-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.9
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    • pp.101-109
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    • 2001
  • The simulated die casting process in which the traditional plaster casting process is combined with rapid prototyping technology is being used to produce Al, Mg and Zn die casting prototypes. Because of lower mechanical properties induced by the large grain structure and incomplete filling, conventional plaster casting is not suitable for the simulated die casting process. A plaster casting process with pressurized vibration was developed for the simulated die casting process[5]. In this paper, numerical simulation for the filling stage of the process has been performed to show the effect of the pressurized vibration for complete filling. Treatment of boundary condition based on the finite element method has been proposed for imparted pressurized vibration in the plaster casting process.

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