• Title/Summary/Keyword: relaxation iterative method

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ON THE CONVERGENCE OF PARALLEL GAOR METHOD FOR BLOCK DIAGONALLY DOMINANT MATRICES

  • Liu, Qingbing
    • Journal of applied mathematics & informatics
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    • v.27 no.5_6
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    • pp.1319-1330
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    • 2009
  • In [2] A.Hadjidimos proposed the generalized accelerated over-relaxation (GAOR) methods which generalize the basic iterative method for the solution of linear systems. In this paper we consider the convergence of the two parallel accelerated generalized AOR iterative methods and obtain some convergence theorems for the case when the coefficient matrix A is a block diagonally dominant matrix or a generalized block diagonally dominant matrix.

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Relaxational stereo matching using adaptive support between disparities (변이간의 적응적 후원을 이용한 이완 스테레오 정합)

  • 도경훈;김용숙;하영호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.3
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    • pp.69-78
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    • 1996
  • This paper presetns an iterative relaxation method for stereo matching using matching probability and compatibility coefficients between disparities. Stereo matching can be considered as the labeling problem of assigning unique matches to feature points of image an relaxation labelin gis an iterative procedure which reduces local ambiguities and achieves global consistency. the relation between disparities is determined from highly reliable matches in initial matching and quantitatively expressed in temrs of compatibility coefficient. The matching results of neighbor pixels support center pixel through compatibility coefficients and update its matching probability. The proposed adaptive method reduces the degradtons on the discontinuities of disparity areas and obtains fast convergence.

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Efficient Iterative Physical Optics(IPO) Algorithms for Calculation of RCS (RCS 계산을 위한 효율적인 IPO 계산 방법)

  • Lee, Hyunsoo;Jung, Ki-Hwan;Chae, Dae-Young;Koh, Il-Suek
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.5
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    • pp.601-606
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    • 2014
  • The IPO(Iterative Physical Optics) method repeatedly applies the well-known PO(Physical Optics) approximation to calculate the scattered field by a large object. Thus, the IPO method can consider the multiple scattering in the object, which is ignored for the PO approximation. This kind of iteration can improve the final accuracy of the induced current on the scatterer, which can result in the enhancement of the accuracy of the RCS(Radar Cross Section) of the scatterer. Since the IPO method can not exactly but approximately solve the required integral equation, however, the convergence of the IPO solution can not be guaranteed. Hence, we apply the famous techniques used in the inversion of a matrix to the IPO method, which include Jacobi, Gauss-Seidel, SOR(Successive Over Relaxation) and Richardson methods. The proposed IPO methods can efficiently calculate the RCS of a large scatterer, and are numerically verified.

INERTIAL PROXIMAL AND CONTRACTION METHODS FOR SOLVING MONOTONE VARIATIONAL INCLUSION AND FIXED POINT PROBLEMS

  • Jacob Ashiwere Abuchu;Godwin Chidi Ugwunnadi;Ojen Kumar Narain
    • Nonlinear Functional Analysis and Applications
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    • v.28 no.1
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    • pp.175-203
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    • 2023
  • In this paper, we study an iterative algorithm that is based on inertial proximal and contraction methods embellished with relaxation technique, for finding common solution of monotone variational inclusion, and fixed point problems of pseudocontractive mapping in real Hilbert spaces. We establish a strong convergence result of the proposed iterative method based on prediction stepsize conditions, and under some standard assumptions on the algorithm parameters. Finally, some special cases of general problem are given as applications. Our results improve and generalized some well-known and related results in literature.

A study on the column subtraction method applied to ship scheduling problem

  • Hwang, Hee-Su;Lee, Hee-Yong;Kim, Si-Hwa
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.401-405
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    • 2004
  • Column subtraction, originally proposed by Harche and Thompson(]994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation. This paper aims at applying the column subtraction method to solve SSP which can not be solved by LP relaxation. For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch-and-bound algorithm by LINDO.

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A study on the column subtraction method applied to ship scheduling problem

  • Hwang, Hee-Su;Lee, Hee-Yong;Kim, Si-Hwa
    • Journal of Navigation and Port Research
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    • v.28 no.2
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    • pp.129-133
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    • 2004
  • Column subtraction, originally proposed by Harche and Thompson(1994), is an exact method for solving large set covering, packing and partitioning problems. Since the constraint set of ship scheduling problem(SSP) have a special structure, most instances of SSP can be solved by LP relaxation This paper aim, at applying the column subtraction method to solve SSP which am not be solved by LP relaxation For remained instances of unsolvable ones, we subtract columns from the finale simplex table to get another integer solution in an iterative manner. Computational results having up to 10,000 0-1 variables show better performance of the column subtraction method solving the remained instances of SSP than complex branch and-bound algorithm by LINDO.

Partitioned analysis of nonlinear soil-structure interaction using iterative coupling

  • Jahromi, H. Zolghadr;Izzuddin, B.A.;Zdravkovic, L.
    • Interaction and multiscale mechanics
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    • v.1 no.1
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    • pp.33-51
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    • 2008
  • This paper investigates the modelling of coupled soil-structure interaction problems by domain decomposition techniques. It is assumed that the soil-structure system is physically partitioned into soil and structure subdomains, which are independently modelled. Coupling of the separately modelled partitioned subdomains is undertaken with various algorithms based on the sequential iterative Dirichlet-Neumann sub-structuring method, which ensures compatibility and equilibrium at the interface boundaries of the subdomains. A number of mathematical and computational characteristics of the coupling algorithms, including the convergence conditions and choice of algorithmic parameters leading to enhanced convergence of the iterative method, are discussed. Based on the presented coupling algorithms a simulation environment, utilizing discipline-oriented solvers for nonlinear structural and geotechnical analysis, is developed which is used here to demonstrate the performance characteristics and benefits of various algorithms. Finally, the developed tool is used in a case study involving nonlinear soil-structure interaction analysis between a plane frame and soil subjected to ground excavation. This study highlights the relative performance of the various considered coupling algorithms in modelling real soil-structure interaction problems, in which nonlinearity arises in both the structure and the soil, and leads to important conclusions regarding their adequacy for such problems as well as the prospects for further enhancements.

Fuzzy Reasoning on Computational Fluid Dynamics - Feasibility of Fuzzy Control for Iterative Method - (CFD에로의 Fuzzy 추론 응용에 관한 연구 - 반복계산을 위한 퍼지제어의 유효성 -)

  • Lee, Y.W.;Jeong, Y.O.;Park, W.C.;Lee, D.H.;Bae, D.S.
    • Journal of Power System Engineering
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    • v.2 no.3
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    • pp.21-26
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    • 1998
  • Numerical simulations for various fluid flows require enormous computing time during iterations. In order to solve this problem, several techniques have been proposed. A SOR method is one of the effective methods for solving elliptic equations. However, it is very difficult to find the optimum relaxation factor, the value of this factor for practical problems used to be estimated on the basis of expertise. In this paper, the implication of the relaxation factor are translated into fuzzy control rules on the basis of the expertise of numerical analysers, and fuzzy controller incorporated into a numerical algorithm. From two cases of study, Poisson equation and cavity flow problem, we confirmed the possibility of computational acceleration with fuzzy logic and qualitative reasoning in numerical simulations. Numerical experiments with the fuzzy controller resulted in generating a good performance.

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Motion Estimation Using Feature Matching and Strongly Coupled Recurrent Module Fusion (특징정합과 순환적 모듈융합에 의한 움직임 추정)

  • 심동규;박래홍
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.12
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    • pp.59-71
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    • 1994
  • This paper proposes a motion estimation method in video sequences based on the feature based matching and anistropic propagation. It measures translation and rotation parameters using a relaxation scheme at feature points and object orinted anistropic propagation in continuous and discontinuous regions. Also an iterative improvement motion extimation based on the strongly coupled module fusion and adaptive smoothing is proposed. Computer simulation results show the effectiveness of the proposed algorithm.

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THE BINOMIAL METHOD FOR A MATRIX SQUARE ROOT

  • Kim, Yeon-Ji;Seo, Jong-Hyeon;Kim, Hyun-Min
    • East Asian mathematical journal
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    • v.29 no.5
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    • pp.511-519
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    • 2013
  • There are various methods for evaluating a matrix square root, which is a solvent of the quadratic matrix equation $X^2-A=0$. We consider new iterative methods for solving matrix square roots of M-matrices. Particulary we show that the relaxed binomial iteration is more efficient than Newton-Schulz iteration in some cases. And we construct a formula to find relaxation coefficients through statistical experiments.