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Ioannis K. Argyros - One of the best experts on this subject based on the ideXlab platform.

  • A New Semi-local Convergence Analysis of the Secant Method
    International Journal of Applied and Computational Mathematics, 2017
    Co-Authors: Ioannis K. Argyros, Ekaterina Nathanson
    Abstract:

    We provide a new semi-local convergence analysis for the Secant Method in a Banach space setting. Argyros and other authors have analyzed the Method using a Lipschitz condition and a simple center Lipschitz condition. However, the Secant Method has two starting vectors \(u_0\), \(u_{-1}\), and it makes sense to analyze it using a mixed center-Lipschitz condition based on both vectors. The direct analysis of the majorizing sequence employed in this paper can be used to obtain weaker convergence conditions than those used in earlier studies. A numerical example is given to further justify the theoretical results.

  • new improved convergence analysis for the Secant Method
    Mathematics and Computers in Simulation, 2016
    Co-Authors: Alberto A Magrenan, Ioannis K. Argyros
    Abstract:

    We present a new convergence analysis, for the Secant Method in order to approximate a locally unique solution of a nonlinear equation in a Banach space. Our idea uses Lipschitz and center–Lipschitz instead of just Lipschitz conditions in the convergence analysis. The new convergence analysis leads to more precise error bounds and to a better information on the location of the solution than the corresponding ones in earlier studies. Numerical examples validating the theoretical results are also provided in this study.

  • expanding the applicability of the Secant Method under weaker conditions
    Applied Mathematics and Computation, 2015
    Co-Authors: Ioannis K. Argyros, Alberto A Magrenan
    Abstract:

    Abstract We present a new semilocal convergence analysis for Secant Method in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. Our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Under the same computational cost on the parameters involved our convergence criteria are weaker and the error bounds more precise than in earlier studies such as (Amat and Busquier, 2003; Amat et al., in press; Argyros and Hilout, 2012; Argyros et al., 2014; Argyros and Magrenan, 2014, 2015; Dennis, 1971; Ezquerro et al., 2000; Ortega and Rheinboldt, 1970; Potra and Ptak, 1984; Schmidt, 1978). Numerical examples are also presented to illustrate the theoretical results obtained in this study.

  • new semilocal and local convergence analysis for the Secant Method
    Applied Mathematics and Computation, 2015
    Co-Authors: Alberto A Magrenan, Ioannis K. Argyros
    Abstract:

    We present a new convergence analysis, for the Secant Method in order to approximate a locally unique solution of a nonlinear equation in a Banach space. Our idea uses Lipschitz and center-Lipschitz instead of just Lipschitz conditions in the convergence analysis. The new convergence analysis leads to more precise error bounds and to a better information on the location of the solution than the corresponding ones in earlier studies such as 2,6,9,11,14,15,17,20,22-26]. Numerical examples validating the theoretical results are also provided in this study.

  • expanding the applicability of Secant Method with applications
    Bulletin of The Korean Mathematical Society, 2015
    Co-Authors: Alberto A Magrenan, Ioannis K. Argyros
    Abstract:

    Abstract. We present new sufficient convergence criteria for the con-vergence of the Secant-Method to a locally unique solution of a nonlinearequation in a Banach space. Our idea uses Lipschitz and center–Lipschitzinstead of just Lipschitz conditions in the convergence analysis. The newconvergence criteria can always be weaker than the corresponding onesin earlier studies. Numerical examples are also provided in this study tosolve equations in cases not possible before. 1. IntroductionIn this study we are concerned with the problem of approximating a locallyunique solution x ⋆ of equation(1.1) F(x) = 0,where F is a Fr´echet–differentiable operator defined on a convex subset D of aBanach space X with values in a Banach space Y.A vast number of problems from applied science including engineering canbe solved by means of finding the solutions equations in a form like (1.1) us-ing mathematical modelling [7,11,16,19]. For example, dynamic systems aremathematically modeled by difference or differential equations, and their so-lutions usually represent the states of the systems. Except in special cases,the solutions of these equations cannot be found in closed form. This is themain reason why the most commonly used solution Methods are iterative. It-eration Methods are also applied for solving optimization problems. In suchcases, the iteration sequences converge to an optimal solution of the problemat hand. Since all of these Methods have the same recursive structure, they canbe introduced and discussed in a general framework. The convergence analy-sis of iterative Methods is usually divided into two categories: semilocal andlocal convergence analysis. In the semilocal convergence analysis one derivesconvergence criteria from the information around an initial point whereas in

Qingbiao Wu - One of the best experts on this subject based on the ideXlab platform.

M J Rubio - One of the best experts on this subject based on the ideXlab platform.

  • improving the applicability of the Secant Method to solve nonlinear systems of equations
    Applied Mathematics and Computation, 2014
    Co-Authors: Sergio Amat, M A Hernandezveron, M J Rubio
    Abstract:

    A modification of the Secant Method for the approximation of nonlinear system of equations is considered to improve the applicability of the Secant Method. This modification changes the resolution of a linear system in each step, necessary to apply the Secant Method, for several matrix multiplications. In this way, the numerical stability of the Secant Method can be improved. In addition, in this paper, we prove that the modification considered keeps two important properties of the Secant Method, such as: does not use derivatives in its algorithm and has R-order of convergence at least 1 + 5 / 2 .

  • semilocal convergence of the Secant Method under mild convergence conditions of differentiability
    Computers & Mathematics With Applications, 2002
    Co-Authors: M A Hernandez, M J Rubio
    Abstract:

    Abstract In this work, we obtain a semilocal convergence result for the Secant Method in Banach spaces under mild convergence conditions. We consider a condition for divided differences which generalizes those usual ones, i.e., Lipschitz continuous and Holder continuous conditions. Also, we obtain a result for uniqueness of solutions.

  • the Secant Method for nondifferentiable operators
    Applied Mathematics Letters, 2002
    Co-Authors: M A Hernandez, M J Rubio
    Abstract:

    In this paper, we use the Secant Method to find a solution of a nonlinear operator equation in Banach spaces. A semilocal convergence result is obtained. For that, we consider a condition for divided differences which generalizes the usual ones, i.e., Lipschitz continuous or Holder continuous conditions. Besides, we apply our results to approximate the solution of a nonlinear equation.

  • the Secant Method and divided differences holder continuous
    Applied Mathematics and Computation, 2001
    Co-Authors: M A Hernandez, M J Rubio
    Abstract:

    We apply the Secant Method to solve non-linear operator equations in Banach spaces. A semilocal convergence result is obtained, where the first-order divided difference of the non-linear operator is Holder continuous. For that, we use a technique based on a new system of recurrence relations to obtain domains of existence and uniqueness of the solution and give an explicit expression for the a priori error bounds. Moreover, we apply our results to the numerical solution of a non-linear boundary value problem of second-order.

  • a new type of recurrence relations for the Secant Method
    International Journal of Computer Mathematics, 1999
    Co-Authors: M A Hernandez, M J Rubio
    Abstract:

    We apply the Secant Method to solve nonlinear operator equations in Banach spaces. We establish a Newton-Kantorovich convergence theorem using a new system of recurrence relations and give an explicit expression for the a priori error bounds. Moreover, we apply our results to the numerical resolution of a nonlinear boundary value problem of second order and improve the error bounds obtained by other authors.

Toshiyuki Koyama - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of Stress-Strain Curve of Two-Phase Microstructure on the Basis of the Extended Secant Method
    Materials Science Forum, 2020
    Co-Authors: Toshiyuki Koyama, Hidehiro Onodera
    Abstract:

    The Secant Method proposed by Weng [1] is a practical calculation Method to evaluate the stress-strain curve of the two-phase materials, but the shape of the inclusion phase has been often assumed to be a sphere or an ellipsoid in the calculation. In this study, we modified the Secant Method by utilizing the phase-field micro-elasticity theory [2,3] so as to be able to calculate the SS-curve of the materials consisting arbitrary morphology of microstructure, and applied this Method to the conventional microstructures in steels, i.e., the ferrite-bainite two-phase microstructure.

  • calculation of stress strain curve of the two phase mixture including ellipsoidal inclusion on the basis of the modified Secant Method
    Tetsu To Hagane-journal of The Iron and Steel Institute of Japan, 2011
    Co-Authors: Toshiyuki Koyama
    Abstract:

    The stress–strain curve of the composite material has been calculated on the basis of the Secant Method proposed by Weng. Although the effect of inclusion shape on the stress–strain curve has been evaluated by Zhao and Weng, they have assumed the inclusion phase to be a rigid elastic medium which dose not deform plastically. In this study, we modified their Secant Method so as to be able to calculate the stress–strain curve of the composite material which contains the plastically deformed inclusion phase, and evaluated the effect of the inclusion shape on the deformation behavior of the stress–strain curve. The results obtained are as follows: When both phases are soft, i.e. the matrix and inclusion phases are both deformable, the stress–strain curve is determined only from the volume fraction of the inclusion phase. In the case that the inclusion phase is hard, i.e. the matrix phase is deformable but the inclusion phase is less deformable, the stress–strain curve depends not only on the volume fraction of the inclusion phase but also on the shape of the inclusion phase. The modified Secant Method proposed in this study will be useful for understanding the effect of inclusion shape on the mechanical property of the composite materials, comprehensively.

Said Hilout - One of the best experts on this subject based on the ideXlab platform.

  • Weaker convergence conditions for the Secant Method
    Applications of Mathematics, 2014
    Co-Authors: Ioannis K. Argyros, Said Hilout
    Abstract:

    We use tighter majorizing sequences than in earlier studies to provide a semilocal convergence analysis for the Secant Method. Our sufficient convergence conditions are also weaker. Numerical examples are provided where earlier conditions do not hold but for which the new conditions are satisfied.

  • Semilocal convergence conditions for the Secant Method, using recurrent functions
    2011
    Co-Authors: Ioannis K. Argyros, Said Hilout
    Abstract:

    Using our new concept of recurrent functions, we present new sufficient convergence conditions for the Secant Method to a locally unique solution of a nonlinear equation in a Banach space. We combine Lipschitz and center-Lipschitz conditions on the divided difference operator to obtain the semilocal convergence analysis of the Secant Method. Our error bounds are tighter than earlier ones. Moreover, under our convergence hypotheses, we can expand the applicability of the Secant Method in cases not covered before [8], [9], [12]-[14], [16], [19]-[21]. Application and examples are also provided in this study.

  • extended sufficient semilocal convergence for the Secant Method
    Computers & Mathematics With Applications, 2011
    Co-Authors: Ioannis K. Argyros, Said Hilout
    Abstract:

    We establish new sufficient convergence conditions for the Secant Method to a locally unique solution of a nonlinear equation in a Banach space. Using our new concept of recurrent functions, and combining Lipschitz and center-Lipschitz conditions on the divided difference operator, we obtain a new semilocal convergence analysis of the Secant Method. Moreover, our sufficient convergence conditions expand the applicability of the Secant Method in cases not covered before (Dennis, 1971 [9], Hernandez et al., 2005 [8], Laasonen, 1969 [15], Ortega and Rheinboldt, 1970 [11], Potra, 1982 [5], Potra, 1985 [7], Schmidt, 1978 [18], Yamamoto, 1987 [12], Wolfe, 1978 [19]). Numerical examples are also provided in this study.