• Title/Summary/Keyword: Fixed Point Iteration

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Digital signal change through artificial intelligence machine learning method comparison and learning (인공지능 기계학습 방법 비교와 학습을 통한 디지털 신호변화)

  • Yi, Dokkyun;Park, Jieun
    • Journal of Digital Convergence
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    • v.17 no.10
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    • pp.251-258
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    • 2019
  • In the future, various products are created in various fields using artificial intelligence. In this age, it is a very important problem to know the operation principle of artificial intelligence learning method and to use it correctly. This paper introduces artificial intelligence learning methods that have been known so far. Learning of artificial intelligence is based on the fixed point iteration method of mathematics. The GD(Gradient Descent) method, which adjusts the convergence speed based on the fixed point iteration method, the Momentum method to summate the amount of gradient, and finally, the Adam method that mixed these methods. This paper describes the advantages and disadvantages of each method. In particularly, the Adam method having adaptivity controls learning ability of machine learning. And we analyze how these methods affect digital signals. The changes in the learning process of digital signals are the basis of accurate application and accurate judgment in the future work and research using artificial intelligence.

Convergence of approximate sequences for compositions of nonexpansive mappings in banach spaces

  • Jung, Jong-Soo;Kim, Tae-Hwa
    • Bulletin of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.93-102
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    • 1997
  • Let C be a nonempty closed convex subset of a Banach space E and let $T_1, \cdots, T_N$ be nonexpansive mappings from C into itself (recall that a mapping $T : C \longrightarrow C$ is nonexpansive if $\left\$\mid$ Tx - Ty \right\$\mid$ \leq \left\$\mid$ x - y \right\$\mid$$ for all $x, y \in C$). We consider the fixed point problem for nonexpansive mappings : find a common fixed point, i.e., find a point in $\cap_{i=1}^N Fix(T_i)$, where $Fix(T_i) := {x \in C : x = T_i x}$ denotes the set of fixed points of $T_i$.

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ON ASYMPTOTICALLY DEMICONTRACTIVE MAPPINGS IN ARBITRARY BANACH SPACES

  • Rafiq, Arif;Lee, Byung Soo
    • East Asian mathematical journal
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    • v.28 no.5
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    • pp.569-578
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    • 2012
  • In this paper, the necessary and sufficient conditions for the strong convergence of a modified Mann iteration process to a fixed point of an asymptotically demicontractive mapping in real Banach spaces are considered. Presented results improve and extend the results of Igbokwe [3], Liu [4], Moore and Nnoli [6] and Osilike [7].

STRONG CONVERGENCE OF A METHOD FOR VARIATIONAL INEQUALITY PROBLEMS AND FIXED POINT PROBLEMS OF A NONEXPANSIVE SEMIGROUP IN HILBERT SPACES

  • Buong, Nguyen
    • Journal of applied mathematics & informatics
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    • v.29 no.1_2
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    • pp.61-74
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    • 2011
  • In this paper, we introduce a new iteration method based on the hybrid method in mathematical programming and the descent-like method for finding a common element of the solution set for a variational inequality and the set of common fixed points of a nonexpansive semigroup in Hilbert spaces. We obtain a strong convergence for the sequence generated by our method in Hilbert spaces. The result in this paper modifies and improves some well-known results in the literature for a more general problem.

IMPROVED GENERALIZED M-ITERATION FOR QUASI-NONEXPANSIVE MULTIVALUED MAPPINGS WITH APPLICATION IN REAL HILBERT SPACES

  • Akutsah, Francis;Narain, Ojen Kumar;Kim, Jong Kyu
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.1
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    • pp.59-82
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    • 2022
  • In this paper, we present a modified (improved) generalized M-iteration with the inertial technique for three quasi-nonexpansive multivalued mappings in a real Hilbert space. In addition, we obtain a weak convergence result under suitable conditions and the strong convergence result is achieved using the hybrid projection method with our modified generalized M-iteration. Finally, we apply our convergence results to certain optimization problem, and present some numerical experiments to show the efficiency and applicability of the proposed method in comparison with other improved iterative methods (modified SP-iterative scheme) in the literature. The results obtained in this paper extend, generalize and improve several results in this direction.

LOCAL CONVERGENCE OF FUNCTIONAL ITERATIONS FOR SOLVING A QUADRATIC MATRIX EQUATION

  • Kim, Hyun-Min;Kim, Young-Jin;Seo, Jong-Hyeon
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.1
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    • pp.199-214
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    • 2017
  • We consider fixed-point iterations constructed by simple transforming from a quadratic matrix equation to equivalent fixed-point equations and assume that the iterations are well-defined at some solutions. In that case, we suggest real valued functions. These functions provide radii at the solution, which guarantee the local convergence and the uniqueness of the solutions. Moreover, these radii obtained by simple calculations of some constants. We get the constants by arbitrary matrix norm for coefficient matrices and solution. In numerical experiments, the examples show that the functions give suitable boundaries which guarantee the local convergence and the uniqueness of the solutions for the given equations.

APPROXIMATION METHODS FOR FINITE FAMILY OF NONSPREADING MAPPINGS AND NONEXPANSIVE MAPPINGS IN HILERT SPACESE

  • Kang, Jinlong;Su, Yongfu
    • Journal of applied mathematics & informatics
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    • v.28 no.1_2
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    • pp.87-98
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    • 2010
  • The purpose of this paper is to prove a weak convergence theorem for a common fixed points of finite family of nonspreading mappings and nonexpansive mappings in Hilbert spaces. The results presented in this paper extend and improve the results of Mondafi [A. Moudafi, Krasnoselski-Mann iteration for hierarchical fixed-point problems, Inverse Problems 23 (2007) 1635-1640], and Iemoto and Takahashi [So Iemoto, W.Takahashi, Approximating common fixed points of nonexpansive mappings and nonspreading mappings in a Hilbert space, Nonlinear Analysis (2009), doi:10.1016/j.na.2009.03.064].

A REMARK ON CONVERGENCE THEORY FOR ITERATIVE PROCESSES OF PROINOV CONTRACTION

  • Bisht, Ravindra K.
    • Communications of the Korean Mathematical Society
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    • v.34 no.4
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    • pp.1157-1162
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    • 2019
  • In this paper, we extend the study of general convergence theorems for the Picard iteration of Proinov contraction from the class of continuous mappings to the class of discontinuous mappings. As a by product we provide a new affirmative answer to the open problem posed in [20].

STRONG CONVERGENCE OF A MODIFIED ISHIKAWA ITERATIVE ALGORITHM FOR LIPSCHITZ PSEUDOCONTRACTIVE MAPPINGS

  • Osilike, M.O.;Isiogugu, F.O.;Attah, F.U.
    • Journal of applied mathematics & informatics
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    • v.31 no.3_4
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    • pp.565-575
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    • 2013
  • Let H be a real Hilbert space and let T : H ${\rightarrow}$ H be a Lipschitz pseudocontractive mapping. We introduce a modified Ishikawa iterative algorithm and prove that if $F(T)=\{x{\in}H:Tx=x\}{\neq}{\emptyset}$, then our proposed iterative algorithm converges strongly to a fixed point of T. No compactness assumption is imposed on T and no further requirement is imposed on F(T).