• 제목/요약/키워드: iterative method

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IEEE 802.11n 기반 MIMO-IC의 간섭정렬 성능평가 (Evaluation of Interference Alignment for MIMO-IC based on IEEE 802.11n)

  • 배인산;윤희석;김재명
    • 한국위성정보통신학회논문지
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    • 제8권4호
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    • pp.47-52
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    • 2013
  • 본 논문에서는, 기존에 연구되었던 간섭정렬 기법들은 주로 레일레이 채널 환경에서 분석이 이뤄졌다. 간섭정렬 기법은 크게 Iterative-method와 Linear-method로 구분되어 지며, Iterative-method는 반복이라는 제약이 있지만 채널정보가 적게 드는 장점이 있다. Linear-method은 광역 채널 정보(global channel info)가 필요하지만 반복에서 자유로우며 비교적 성능이 우수하다. 이 논문에서는 기존의 간섭정렬 기법들을 실외 환경의 레일리에 패이딩 채널과 실내 환경인 IEEE 802.11n 채널에 적용함으로써 성능을 비교하고자 한다.

Rural Postman Problem 해법을 위한 Iterative Local Search 알고리즘 (An Iterative Local Search Algorithm for Rural Postman Problems)

  • 강명주
    • 한국컴퓨터정보학회논문지
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    • 제7권1호
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    • pp.48-53
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    • 2002
  • 본 논문에서는 Rural Postman Problem(RPP) 해법을 위한 Iterative Local Search(ILS) 알고리즘을 제안한다. ILS 알고리즘은 초기해를 여러 번 생성하여 탐색 시작점을 달리하는 방법으로, 초기해의 설정 방법에 따라 알고리즘의 성능이 크게 좌우되는 Local Search(LS) 알고리즘의 단점을 보완할 수 있다. 본 논문에서는 LS 알고리즘과 ILS 알고리즘을 18개의 RPP 문제에 적용하고 그 성능을 분석한다. 실험 결과에서는 ILS 알고리즘이 각각 다른 탐색 시작점에서 해 공간을 탐색함으로서 LS에 비해 좋은 해를 찾을 수 있음을 알 수 있었다.

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Aggregation multigrid method for schur complement system in FE analysis of continuum elements

  • Ko, Jin-Hwan;Lee, Byung Chai
    • Structural Engineering and Mechanics
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    • 제30권4호
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    • pp.467-480
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    • 2008
  • An aggregation multigrid method (AMM) is a leading iterative solver in solid mechanics. Recently, AMM is applied for solving Schur Complement system in the FE analysis of shell structures. In this work, an extended application of AMM for solving Schur Complement system in the FE analysis of continuum elements is presented. Further, the performance of the proposed AMM in multiple load cases, which is a challenging problem for an iterative solver, is studied. The proposed method is developed by combining the substructuring and the multigrid methods. The substructuring method avoids factorizing the full-size matrix of an original system and the multigrid method gives near-optimal convergence. This method is demonstrated for the FE analysis of several elastostatic problems. The numerical results show better performance by the proposed method as compared to the preconditioned conjugate gradient method. The smaller computational cost for the iterative procedure of the proposed method gives a good alternative to a direct solver in large systems with multiple load cases.

ITERATIVE APPROXIMATION TO M-ACCRETIVE OPERATOR EQUATIONS IN BANACH SPACES

  • Park, Jong An;Park, Yang Seob
    • Korean Journal of Mathematics
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    • 제4권2호
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    • pp.83-88
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    • 1996
  • In 1994 Z.Liang constructed an iterative method for the solution of nonlinear equations involving m-accretive operators in uniformly smooth Banach spaces. In this paper we apply the slight variants of Liang's iterative methods and generalize the results of Z.Liang. Moreover our proof is more simple than Liang's proof.

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Finite element analysis of vehicle-bridge interaction by an iterative method

  • Jo, Ji-Seong;Jung, Hyung-Jo;Kim, Hongjin
    • Structural Engineering and Mechanics
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    • 제30권2호
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    • pp.165-176
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    • 2008
  • In this paper, a new iterative method for solving vehicle-bridge interaction problems is proposed. Iterative methods have advantages over the non-iterative methods in that it is not necessary to update the system matrix for a given wheel location, and the method can be applied for a new type of car or bridge with few or no modifications. In the proposed method, the necessity of system matrices update is eliminated using the equivalent interaction force acting on the bridge, which is obtained iteratively. Ballast stiffness is included in the interaction forces and the geometric compatibility at the contact points are used as convergence criteria. The bridge is considered as an elastic Bernoulli-Euler beam with surface irregularity and ballast stiffness. The moving vehicle is modeled as a multi-axle mass-spring-damper system having many degrees of freedom depending on the number of axles. The pitching effect, which is the interaction effect between the rear and front wheels when a vehicle begins to enter or leave the bridge, is also considered in the formulation including extended ground boundaries having surface irregularity and ballast stiffness. The applicability of the proposed method is illustrated in the numerical studies.

Evaluation of Non-iterative Shimming Using 2-D Field Map Compared with Simplex Shimming

  • Park, Min-Seok;Kim, Si-Seung;Park, Dae-Jun;Chung, Sung-Taek
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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    • pp.152-152
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    • 2001
  • Purpose: The most common instrumental approach to automatic shimming has been based on iterativ. optimization routine(e.g., simplex) to adjust shim settings to maximize the envelope of the FID. Disadvantage of iterative method, however, is very long to compute shim values. Thi paper supposes a non-iterative method that uses 2-D field map to adjust shim settin rapidly.

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반복적인 알고리즘 방법에 의한 효과적인 양평균 검출 및 영상분할에 응용 (An Effective Detection of Bimean and its Application into Image Segmentation by an Interative Algorithm Method)

  • 허필우
    • 연구논문집
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    • 통권25호
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    • pp.147-154
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    • 1995
  • In this paper, we discussed the convergence and the properties of an iterative algorithm method in order to improve a bimean clustering algorithm. This algorithm that we have discussed choose automatically an optimum threshold as a result of an iterative process, successive iterations providing increasingly cleaner extractions of the object region, The iterative approach of a proposed algorithm is seen to select an appropriate threshold for the low contrast images.

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FUZZY SLIDING MODE ITERATIVE LEARNING CONTROL Of A MANIPULATOR

  • Park, Jae-Sam
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -3
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    • pp.1483-1486
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    • 2002
  • In this paper, a new scheme of iterative loaming control of a robot manipulator is presented. The proposed method uses a fuzzy sliding mode controller(FSMC), which is designed based on the similarity between the fuzzy logic control(FLC) and the sliding mode control(SMC), for the feedback. With this, the proposed method makes possible fDr fast iteration and has advantages that no linear approximation is used for the derivation of the learning law or in the stability proof Full proof of the convergence of the fuzzy sliding base learning scheme Is given.

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