• Title/Summary/Keyword: iterative method

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

  • Bae, Insan;Yun, Heesuk;Kim, Jaemoung
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.47-52
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    • 2013
  • In this paper, The existing interference alignment algorithms were analyzed in Rayleigh fading channel environment. The interference alignment techniques are divided to two parts. First thing is Iterative-method, another is Linear-method. Iterative method needs local channel info, but it has the constraint of iteration. On the other hand Linear-method must have global channel info, but has free of iteration and better performance. This paper evaluates the performance of interference alignment algorithms in Rayleigh fading channel of outdoor environment and WLAN channel based on IEEE 802.11n of indoor environment.

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

  • 강명주
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.1
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    • pp.48-53
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    • 2002
  • This paper Proposes an iterative Local Search (ILS) algorithm for Rural Postman Problems (RPPs). LS searches neighbors from an initial solution in solution space and obtains a nearoptimal solution which can be a local-minima. As an extension of LS, the ILS algorithm is a method that uses various initial solutions for LS. Hence. ILS can overcome the defect of LS. This paper proposes LS and ILS methods for 18 RPPs and analyzes the results of LS and ILS. In the simulation results, the ILS method obtained the better results than the LS method.

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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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    • v.30 no.4
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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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    • v.4 no.2
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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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    • v.30 no.2
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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
    • Proceedings of the KSMRM Conference
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    • 2001.11a
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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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An Effective Detection of Bimean and its Application into Image Segmentation by an Interative Algorithm Method (반복적인 알고리즘 방법에 의한 효과적인 양평균 검출 및 영상분할에 응용)

  • Heo, Pil-U
    • 연구논문집
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    • s.25
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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
    • Proceedings of the IEEK Conference
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    • 2002.07c
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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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