• 제목/요약/키워드: Iterative algorithm

검색결과 1,400건 처리시간 0.022초

STRONG CONVERGENCE OF STRICT PSEUDO-CONTRACTIONS IN Q-UNIFORMLY SMOOTH BANACH SPACES

  • Pei, Yonggang;Liu, Fujun;Gao, Qinghui
    • Journal of applied mathematics & informatics
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    • 제33권1_2호
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    • pp.13-31
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    • 2015
  • In this paper, we introduce a general iterative algorithm for finding a common element of the common fixed point set of an infinite family of ${\lambda}_i$-strict pseudo-contractions and the solution set of a general system of variational inclusions for two inverse strongly accretive operators in q-uniformly smooth Banach spaces. Then, we analyze the strong convergence of the iterative sequence generated by the proposed iterative algorithm under mild conditions.

ON GENERALIZED NONLINEAR QUASI-VARIATIONAL-LIKE INCLUSIONS DEALING WITH (h,η)-PROXIMAL MAPPING

  • Liu, Zeqing;Chen, Zhengsheng;Shim, Soo-Hak;Kang, Shin-Min
    • 대한수학회지
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    • 제45권5호
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    • pp.1323-1339
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    • 2008
  • In this paper, a new class of $(h,{\eta})$-proximal for proper functionals in Hilbert spaces is introduced. The existence and Lip-schitz continuity of the $(h,{\eta})$-proximal mappings for proper functionals are proved. A class of generalized nonlinear quasi-variational-like inclusions in Hilbert spaces is introduced. A perturbed three-step iterative algorithm with errors for the generalized nonlinear quasi-variational-like inclusion is suggested. The existence and uniqueness theorems of solution for the generalized nonlinear quasi-variational-like inclusion are established. The convergence and stability results of iterative sequence generated by the perturbed three-step iterative algorithm with errors are discussed.

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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GRAPH CONVERGENCE AND GENERALIZED CAYLEY OPERATOR WITH AN APPLICATION TO A SYSTEM OF CAYLEY INCLUSIONS IN SEMI-INNER PRODUCT SPACES

  • Mudasir A. Malik;Mohd Iqbal Bhat;Ho Geun Hyun
    • Nonlinear Functional Analysis and Applications
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    • 제28권1호
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    • pp.265-286
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    • 2023
  • In this paper, we introduce and study a generalized Cayley operator associated to H(·, ·)-monotone operator in semi-inner product spaces. Using the notion of graph convergence, we give the equivalence result between graph convergence and convergence of generalized Cayley operator for the H(·, ·)-monotone operator without using the convergence of the associated resolvent operator. To support our claim, we construct a numerical example. As an application, we consider a system of generalized Cayley inclusions involving H(·, ·)-monotone operators and give the existence and uniqueness of the solution for this system. Finally, we propose a perturbed iterative algorithm for finding the approximate solution and discuss the convergence of iterative sequences generated by the perturbed iterative algorithm.

개선된 이진 확장 GCD 알고리듬 기반 GF(2163)상에서 Iterative 나눗셈기 설계 (Design of Iterative Divider in GF(2163) Based on Improved Binary Extended GCD Algorithm)

  • 강민섭;전병찬
    • 정보처리학회논문지C
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    • 제17C권2호
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    • pp.145-152
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    • 2010
  • 본 논문에서는 표준기저(standard basis) 표기법을 이용하여 GF($2^{163}$) 상에서개선된 나눗셈 알고리듬을 제안하고, 제안한 알고리듬을 기반으로 한 반복 하드웨어 구조(iterative hardware structure)를 갖는 고속 나눗셈기를 설계한다. 제안한알고리듬은 이진 확장 GCD 알고리듬을 기본으로 하고 있으며, 모듈러감소 (modular reduction)를 위한 모든 산술연산은 기존의 방법과 달리 하나의 while루프 내에서 수행된다. 제안된 알고리듬을 기본으로 하여 설계된 나눗셈기는 모듈러 연산을 위한 각 모듈이 하나의 클럭에 의해서제어되므로 계산 속도가 매우 빠르다. 여기에서 사용하는 감소 다항식(reduction polynomial)은 SEC2 (Standards for Efficient Cryptography) 에서 권장하는 $f(x)=x^{163}+x^7+x^6+x^3+1$이며, 차수(degree) m은 163을 사용한다. 제안한 알고리듬은 Verilog HDL(Hardware Description Language)을 사용하여 FPGA로 구현되었으며, Xilinx-VirtexII XC2V8000 FPGA 상에서 85MHz로 동작함을 확인하였다. 또한, 구현 결과 및 성능 평가를 통하여 제안한 알고리듬의 종래의 두 알고리듬보다 성능이크게 개선됨을 보인다.

Modal control algorithm on optimal control of intelligent structure shape

  • Yao, Guo Feng;Chen, Su Huan;Wang, Wei
    • Structural Engineering and Mechanics
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    • 제15권4호
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    • pp.451-462
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    • 2003
  • In this paper, a new block iterative algorithm is presented by using the special feature of the continuous Riccati equation in the optimal shape control. Because the real-time control require that the CPU time should be as short as possible, an appropriate modal control algorithm is sought. The computing cost is less than the one of the all state feedback control. A numerical example is given to illustrate the algorithm.

Sparse-View CT Image Recovery Using Two-Step Iterative Shrinkage-Thresholding Algorithm

  • Chae, Byung Gyu;Lee, Sooyeul
    • ETRI Journal
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    • 제37권6호
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    • pp.1251-1258
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    • 2015
  • We investigate an image recovery method for sparse-view computed tomography (CT) using an iterative shrinkage algorithm based on a second-order approach. The two-step iterative shrinkage-thresholding (TwIST) algorithm including a total variation regularization technique is elucidated to be more robust than other first-order methods; it enables a perfect restoration of an original image even if given only a few projection views of a parallel-beam geometry. We find that the incoherency of a projection system matrix in CT geometry sufficiently satisfies the exact reconstruction principle even when the matrix itself has a large condition number. Image reconstruction from fan-beam CT can be well carried out, but the retrieval performance is very low when compared to a parallel-beam geometry. This is considered to be due to the matrix complexity of the projection geometry. We also evaluate the image retrieval performance of the TwIST algorithm -sing measured projection data.

Large strain analysis of two-dimensional frames by the normal flow algorithm

  • Tabatabaei, R.;Saffari, H.
    • Structural Engineering and Mechanics
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    • 제36권5호
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    • pp.529-544
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    • 2010
  • Nonlinear equations of structures are generally solved numerically by the iterative solution of linear equations. However, this iterative procedure diverges when the tangent stiffness is ill-conditioned which occurs near limit points. In other words, a major challenge with simple iterative methods is failure caused by a singular or near singular Jacobian matrix. In this paper, using the Newton-Raphson algorithm based on Davidenko's equations, the iterations can traverse the limit point without difficulty. It is argued that the propose algorithm may be both more computationally efficient and more robust compared to the other algorithm when tracing path through severe nonlinearities such as those associated with structural collapse. Two frames are analyzed using the proposed algorithm and the results are compared with the previous methods. The ability of the proposed method, particularly for tracing the limit points, is demonstrated by those numerical examples.

STRONG CONVERGENCE OF GENERAL ITERATIVE ALGORITHMS FOR NONEXPANSIVE MAPPINGS IN BANACH SPACES

  • Jung, Jong Soo
    • 대한수학회지
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    • 제54권3호
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    • pp.1031-1047
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    • 2017
  • In this paper, we introduce two general iterative algorithms (one implicit algorithm and other explicit algorithm) for nonexpansive mappings in a reflexive Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm. Strong convergence theorems for the sequences generated by the proposed algorithms are established.

EXTRA-GRADIENT METHODS FOR QUASI-NONEXPANSIVE OPERATORS

  • JEONG, JAE UG
    • Journal of applied mathematics & informatics
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    • 제34권5_6호
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    • pp.467-478
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    • 2016
  • In this paper, we propose an Ishikawa-type extra-gradient iterative algorithm for finding a solution of split feasibility, fixed point problems and equilibrium problems of quasi-nonexpansive mappings. It is proven that under suitable conditions, the sequences generated by the proposed iterative algorithms converge weakly to a solution of the split feasibility, fixed point problems and equilibrium problems. An example is given to illustrate the main result of this paper.