• 제목/요약/키워드: Iteration Method

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비선형 해석에 의한 원형박판의 안정성 연구 (A Study on the Stability of Circular Thin Plates by Nonlinear Analysis)

  • 김치경
    • 대한안전경영과학회지
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    • 제13권2호
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    • pp.97-102
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    • 2011
  • 본 연구에서는 원형 박판 구조물의 안정성에 대하여 해석 하였다. 임계하중은 하중을 점차적으로 증가하여 구조물이 파괴가 발생하여 안정성을 상실 하는 상태에서 가장 작은 하중을 의미한다. 판구조의 안정성을 임계하중의 크기로 기초를 두고 해석 하였다. 원형 박판구조의 차분해석은 일반 판구조와 같으므로 최근에 많은 연구의 대상이 되어왔다. 차분법은 복잡한 구조물에서도 물론, 다양한 경계조건을 포함하는 문제에 이르기까지 효과적인 수치방법이다. 본 연구에서는 기본 박판구조의 지배방정식을 유도하고 차분화 하여 직접적으로 접근하였다. 원 둘레 의 지점이 힌지 받침으로, 등분포 하중을 받고 있는 박판을 기하학적 비선형 해석으로 수행하여 원형 박판의 처짐 및 응력을 해석 하였다.

Methods to improve Log-MAP Decoding in Frequency Selective Fading Channels

  • Kim, Jeong-Su
    • 한국컴퓨터정보학회논문지
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    • 제21권9호
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    • pp.51-55
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    • 2016
  • High-capacity, high quality services should be guaranteed in mobile communication environment. Excellent channel coding and compensation techniques are required so as to improve data reliability on fading channels. In this paper, we propose a method using double pilots, estimates and compensates for the fading of information symbols. The proposed method using Log-MAP Turbo decoder through the iterative decoder, improves BER performance under the environment of the frequency selective fading channel. Compared to the existing methods, the suggested methods show functional improvement of approximately 3dB in case that the number of iteration decoding is 5 and BER is $10^{-4}$.

비선형 이론을 이용한 케이블 네트의 형태안정 (A shape finding of cable net by nonlinear theory)

  • 황보석;서삼열;권택진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1990년도 봄 학술발표회 논문집
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    • pp.59-64
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    • 1990
  • The cable structures undergo large deformation because of its highly flexibility. Therefore, we must take account of its geometric nonlinearity before analysis and find the equiribrated shape of cable structures. To solve these problems, a numerical procedures included nonlinear near theory which is applicable to general cable net, flexible transmission lines and suspended cable roofs, are presented in this paper. Now, this procedures are devided two parts : the one is to obtain the equibrated shape and stress of the cable structures applied uniform load by flexibility iteration method, the other is to analysis the equibrated structures subjected to nodal external forces by nonlinear finite element mothed. Its accuracy and efficiency are found to be comparable to some of other method and, in some aspect, it is mere applicable to cable structures.

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상호작용식 다목적 선형계획과정에서의 수렴 통제 방법 (A convergence Control Method in the Interactive Multiple Objective Linear Programming(MOLP) Procedure)

  • Park, Young Woong
    • 산업경영시스템학회지
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    • 제20권43호
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    • pp.299-319
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    • 1997
  • Since a convergence strategy in interactive procedure is the origin of a lot of the restrictions and inconvenience of many methods, a new flexible convergence strategy is necessary for developing that is applicable for interactive MOLP as well as interactive multiple objective integer programming(MOIP). A method for computing the volume of the interval defined subsets of weighting vector space is developed using Sobol's LP$_{i}$, Generator. Since the interactive procedure requires a number of iterations, with a fixed number of solutions presented per iteration, a convergence strategy is needed to control the rate at which the interactive procedure converges to a final solution. Thus, in this paper, a new convergency strategy is developed.

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A Robust and Computationally Efficient Optimal Design Algorithm of Electromagnetic Devices Using Adaptive Response Surface Method

  • Zhang, Yanli;Yoon, Hee-Sung;Shin, Pan-Seok;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • 제3권2호
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    • pp.207-212
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    • 2008
  • This paper presents a robust and computationally efficient optimal design algorithm for electromagnetic devices by combining an adaptive response surface approximation of the objective function and($1+{\lambda}$) evolution strategy. In the adaptive response surface approximation, the design space is successively reduced with the iteration, and Pareto-optimal sampling points are generated by using Latin hypercube design with the Max Distance and Min Distance criteria. The proposed algorithm is applied to an analytic example and TEAM problem 22, and its robustness and computational efficiency are investigated.

고속 WALSH 변환에 의한 분포정수계의 최적제어 (Optimal Control of Distributed Parameter Systems Via Fast WALSH Transform)

  • 김태훈;김진태;이승;안두수
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권10호
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    • pp.464-472
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    • 2001
  • This study uses distributed parameter systems as the spatial discretization technique, modelling in lumped parameter systems, and applies fast WALSH transform and the Picard's iteration method to high order partial differential equations and matrix partial differential equations. This thesis presents a new algorithm which usefully exercises the optimal control in the distributed parameter systems. In exercising optimal control of distributed parameter systems, excellent consequences are found without using the existing decentralized control or hierarchical control method. This study will help apply to linear time-varying systems and non-linear systems. Further research on algorithm will be required to solve the problems of convergence in case of numerous applicable intervals.

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역추적 방식의 시스토릭 어레이 구조를 가진 연판정 비터비 복호기의 설계 (VLSI Design of Soft Decision Viterbi Decoder Using Systolic Array Architecture)

  • 김기보;김종태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 G
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    • pp.3199-3201
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    • 1999
  • Convolutional coding with Viterbi decoding is known as a powerful method for forward error correction among many kinds of channel coding methods. This paper presents a soft decision Viterbi decoder which has systolic array trace-back architecture[1]. Soft decision is known as more effective method than hard decision and most of digital communication systems use soft decision. The advantage of using a systolic array decoder is that the trace-back operation can be accomplished continuously in an array of registers in a pipe-line fashion, instead of waiting for the entire trace-back procedure to be completed at each iteration. Therefore it may be suitable for faster communication system. We described operations of each module of the decoder and showed results of the logic synthesis and functional simulation.

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점성-비점성 유동 반복계산 방법을 이용한 2차원 자동차모형의 공력 특성 예측 (Predicting aerodynamic characteristics of two-dimensional automobile shapes in ground proximity using an iterative viscous-potential flow technique)

  • 최도형;최철진
    • 오토저널
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    • 제8권1호
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    • pp.52-61
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    • 1986
  • An iterative viscous-potential flow procedure has been developed and used to predict aerodynamic characteristics of automobiles in ground proximity. The method is capable of predicting the effects of separated flows. The viscous-potential flow iteration procedure provides the connection between potential flow, boundary layer and wake modules. The separated wake is modeled in the potential flow analysis by thin sheets across which exists a jump in velocity potential. The ground effect is properly accounted for by placing a body image in the potential flow calculation. The agreement between theory and experiment is good and, thus, demonstrates that the method can be used in the preliminary design stage.

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분포정수회로 해석 방법을 이용한 지중선로 고장점 추정 알고리즘 (A Novel Algorithm of Underground Cable Fault Location based on the analysis of Distributed Parameter Circuit)

  • 이덕수;양하;최면송
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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    • pp.24-27
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    • 2004
  • This paper proposes a new algorithm of underground cable fault location based on the analysis of distributed parameter circuit. The proposed method firstly makes voltage and current equations for each of cores and sheathes respectively, and then establishes an equation of the fault distance according to the analysis of the fault conditions. Finally the solution of this equation is calculated by Newton-Raphson iteration method. The effectiveness of this proposed algorithm has been proven through PSCAD/EMTDC simulations.

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고속 월쉬 변환을 이용한 분포정수계의 해석에 관한 연구 (A Study on Analysis of Distributed Parameter Systems via Fast Walsh Transform)

  • 김태훈;김진태;채영무;이해기;김종부;안두수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2084-2086
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    • 2001
  • This study uses distributed parameter systems as the spatial discretization technique, modelling in lumped parameter systems, and applies orthogonal transform and the Picard's iteration method to high order partial differential equations and matrix partial differential equations. In exercising optimal control of distributed parameter systems, excellent consequences are found without using the existing decentralized control or hierarchical control method.

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