• 제목/요약/키워드: fixed-point iteration

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이방성 재료의 소성변형 해석을 위한 고정점 축차 (Fixed-point Iteration for the Plastic Deformation Analysis of Anisotropic Materials)

  • 양승용;김정한
    • 한국분말재료학회지
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    • 제30권1호
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    • pp.29-34
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    • 2023
  • A fixed-point iteration is proposed to integrate the stress and state variables in the incremental analysis of plastic deformation. The Conventional Newton-Raphson method requires a second-order derivative of the yield function to generate a complicated code, and the convergence cannot be guaranteed beforehand. The proposed fixed-point iteration does not require a second-order derivative of the yield function, and convergence is ensured for a given strain increment. The fixed-point iteration is easier to implement, and the computational time is shortened compared with the Newton-Raphson method. The plane-stress condition is considered for the biaxial loading conditions to confirm the convergence of the fixed-point iteration. 3-dimensional tensile specimen is considered to compare the computational times in the ABAQUS/explicit finite element analysis.

REPULSIVE FIXED-POINTS OF THE LAGUERRE-LIKE ITERATION FUNCTIONS

  • Ham, YoonMee;Lee, Sang-Gu
    • Korean Journal of Mathematics
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    • 제16권1호
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    • pp.51-55
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    • 2008
  • Let f be an analytic function with a simple zero in the reals or the complex numbers. An extraneous fixed-point of an iteration function is a fixed-point different from a zero of f. We prove that all extraneous fixed-points of Laguerre-like iteration functions and general Laguerre-like functions are repulsive.

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COMMON FIXED POINT THEOREMS FOR MANN TYPE ITERATIONS

  • Sharma, Sushil;Deshpande, Bhavana
    • East Asian mathematical journal
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    • 제17권1호
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    • pp.19-32
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    • 2001
  • In this paper, we give some common fixed point theorems for five and six mappings satisfying the Mann-type iteration in Banach spaces. We improve some results of Gornicki and Rhoades, Khan and Imdad, Cho, Fisher and Kang, Cirick and many others.

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APPLICATIONS OF FIXED POINT THEORY IN HILBERT SPACES

  • Kiran Dewangan
    • Korean Journal of Mathematics
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    • 제32권1호
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    • pp.59-72
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    • 2024
  • In the presented paper, the first section contains strong convergence and demiclosedness property of a sequence generated by Karakaya et al. iteration scheme in a Hilbert space for quasi-nonexpansive mappings and also the comparison between the iteration scheme given by Karakaya et al. with well-known iteration schemes for the convergence rate. The second section contains some applications of the fixed point theory in solution of different mathematical problems.

Stabilization effect of fission source in coupled Monte Carlo simulations

  • Olsen, Borge;Dufek, Jan
    • Nuclear Engineering and Technology
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    • 제49권5호
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    • pp.1095-1099
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    • 2017
  • A fission source can act as a stabilization element in coupled Monte Carlo simulations. We have observed this while studying numerical instabilities in nonlinear steady-state simulations performed by a Monte Carlo criticality solver that is coupled to a xenon feedback solver via fixed-point iteration. While fixed-point iteration is known to be numerically unstable for some problems, resulting in large spatial oscillations of the neutron flux distribution, we show that it is possible to stabilize it by reducing the number of Monte Carlo criticality cycles simulated within each iteration step. While global convergence is ensured, development of any possible numerical instability is prevented by not allowing the fission source to converge fully within a single iteration step, which is achieved by setting a small number of criticality cycles per iteration step. Moreover, under these conditions, the fission source may converge even faster than in criticality calculations with no feedback, as we demonstrate in our numerical test simulations.

STRONG CONVERGENCE THEOREM OF FIXED POINT FOR RELATIVELY ASYMPTOTICALLY NONEXPANSIVE MAPPINGS

  • Qin, Xiaolong;Kang, Shin Min;Cho, Sun Young
    • 충청수학회지
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    • 제21권3호
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    • pp.327-337
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    • 2008
  • In this paper, we prove strong convergence theorems of Halpern iteration for relatively asymptotically nonexpansive mappings in the framework of Banach spaces. Our results extend and improve the recent ones announced by [C. Martinez-Yanes, H. K. Xu, Strong convergence of the CQ method for fixed point iteration processes, Nonlinear Anal. 64 (2006), 2400-2411], [X. Qin, Y. Su, Strong convergence theorem for relatively nonexpansive mappings in a Banach space, Nonlinear Anal. 67 (2007), 1958-1965] and many others.

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Mann-Iteration process for the fixed point of strictly pseudocontractive mapping in some banach spaces

  • Park, Jong-An
    • 대한수학회지
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    • 제31권3호
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    • pp.333-337
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    • 1994
  • Many authors[3][4][5] constructed and examined some processes for the fixed point of strictly pseudocontractive mapping in various Banach spaces. In fact the fixed point of strictly pseudocontractive mapping is the zero of strongly accretive operators. So the same processes are used for the both circumstances. Reich[3] proved that Mann-iteration precess can be applied to approximate the zero of strongly accretive operator in uniformly smooth Banach spaces. In the above paper he asked whether the fact can be extended to other Banach spaces the duals of which are not necessarily uniformly convex. Recently Schu[4] proved it for uniformly continuous strictly pseudocontractive mappings in smooth Banach spaces. In this paper we proved that Mann-iteration process can be applied to approximate the fixed point of strictly pseudocontractive mapping in certain Banach spaces.

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AN EFFICIENT THIRD ORDER MANN-LIKE FIXED POINT SCHEME

  • Pravin, Singh;Virath, Singh;Shivani, Singh
    • Nonlinear Functional Analysis and Applications
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    • 제27권4호
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    • pp.785-795
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    • 2022
  • In this paper, we introduce a Mann-like three step iteration method and show that it can be used to approximate the fixed point of a weak contraction mapping. Furthermore, we prove that this scheme is equivalent to the Mann iterative scheme. A comparison is made with the other third order iterative methods. Results are presented in a table to support our conclusion.

확장된 고정점이론을 이용한 비선형시스템의 근을 구하는 방법 (A New Method of Finding Real Roots of Nonlinear System Using Extended Fixed Point Iterations)

  • 김성수;김지수
    • 전기학회논문지
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    • 제67권2호
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    • pp.277-284
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    • 2018
  • In this paper, a new numerical method of finding the roots of a nonlinear system is proposed, which extends the conventional fixed point iterative method by relaxing the constraints on it. The proposed method determines the real valued roots and expands the convergence region by relaxing the constraints on the conventional fixed point iterative method, which transforms the diverging root searching iterations into the converging iterations by employing the metric induced by the geometrical characteristics of a polynomial. A metric is set to measure the distance between a point of a real-valued function and its corresponding image point of its inverse function. The proposed scheme provides the convenience in finding not only the real roots of polynomials but also the roots of the nonlinear systems in the various application areas of science and engineering.

CONVERGENCE OF A NEW MULTISTEP ITERATION IN CONVEX CONE METRIC SPACES

  • Gunduz, Birol
    • 대한수학회논문집
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    • 제32권1호
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    • pp.39-46
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    • 2017
  • In this paper, we propose a new multistep iteration for a finite family of asymptotically quasi-nonexpansive mappings in convex cone metric spaces. Then we show that our iteration converges to a common fixed point of this class of mappings under suitable conditions. Our result generalizes the corresponding result of Lee [5] from the closed convex subset of a convex cone metric space to whole space.