• 제목/요약/키워드: Newton-type methods

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ON THE RADIUS OF CONVERGENCE OF SOME NEWTON-TYPE METHODS IN BANACH SPACES

  • Argyros, Ioannis K.;Hilout, Said
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제18권3호
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    • pp.219-230
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    • 2011
  • We determine the radius of convergence for some Newton{type methods (NTM) for approximating a locally unique solution of an equation in a Banach space setting. A comparison is given between the radii of (NTM) and Newton's method (NM). Numerical examples further validating the theoretical results are also provided in this study.

APPROXIMATING SOLUTIONS OF EQUATIONS BY COMBINING NEWTON-LIKE METHODS

  • Argyros, Ioannis K.
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제15권1호
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    • pp.35-45
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    • 2008
  • In cases sufficient conditions for the semilocal convergence of Newtonlike methods are violated, we start with a modified Newton-like method (whose weaker convergence conditions hold) until we stop at a certain finite step. Then using as a starting guess the point found above we show convergence of the Newtonlike method to a locally unique solution of a nonlinear operator equation in a Banach space setting. A numerical example is also provided.

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A KANTOROVICH-TYPE CONVERGENCE ANALYSIS FOR THE QUASI-GAUSS-NEWTON METHOD

  • Kim, S.
    • 대한수학회지
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    • 제33권4호
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    • pp.865-878
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    • 1996
  • We consider numerical methods for finding a solution to a nonlinear system of algebraic equations $$ (1) f(x) = 0, $$ where the function $f : R^n \to R^n$ is ain $x \in R^n$. In [10], a quasi-Gauss-Newton method is proposed and shown the computational efficiency over SQRT algorithm by numerical experiments. The convergence rate of the method has not been proved theoretically. In this paper, we show theoretically that the iterate $x_k$ obtained from the quasi-Gauss-Newton method for the problem (1) actually converges to a root by Kantorovich-type convergence analysis. We also show the rate of convergence of the method is superlinear.

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THE EFFECT OF ROUNDING ERRORS ON NEWTON METHODS

  • Argyros, Ioannis K.
    • Journal of applied mathematics & informatics
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    • 제7권3호
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    • pp.765-772
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    • 2000
  • In this study we are concerned with the problem of approximating a solution of a nonlinear equation in Banach space using Newton-like methods. Due to rounding errors the sequence of iterates generated on a computer differs from the sequence produced in theory. Using Lipschitz-type hypotheses on the second Frechet-derivative instead of the first one, we provide sufficient convergence conditions for the inexact Newton-like method that is actually generated on the computer. Moreover, we show that the ratio of convergence improves under our conditions. Furthermore, we provide a wider choice of initial guesses than before. Finally, a numerical example is provided to show that our results compare favorably with earlier ones.

ON THE CONVERGENCE OF INEXACT TWO-STEP NEWTON-TYPE METHODS USING RECURRENT FUNCTIONS

  • Argyros, Ioannis K.;Hilou, Said
    • East Asian mathematical journal
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    • 제27권3호
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    • pp.319-337
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    • 2011
  • We approximate a locally unique solution of a nonlinear equation in a Banach space setting using an inexact two-step Newton-type method. It turn out that under our new idea of recurrent functions, our semilocal analysis provides tighter error bounds than before, and in many interesting cases, weaker sufficient convergence conditions. Applications including the solution of nonlinear Chandrasekhar-type integral equations appearing in radiative transfer and two point boundary value problems are also provided in this study.

GENERALIZED CONDITIONS FOR THE CONVERGENCE OF INEXACT NEWTON-LIKE METHODS ON BANACH SPACES WITH A CONVERGENCE STRUCTURE AND APPLICATIONS

  • Argyros, Ioannis-K.
    • Journal of applied mathematics & informatics
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    • 제5권2호
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    • pp.433-448
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    • 1998
  • In this study we use inexact Newton-like methods to find solutions of nonlinear operator equations on Banach spaces with a convergence structure. Our technique involves the introduction of a generalized norm as an operator from a linear space into a par-tially ordered Banach space. In this way the metric properties of the examined problem can be analyzed more precisely. Moreover this approach allows us to derive from the same theorem on the one hand semi-local results of kantorovich-type and on the other hand 2global results based on monotonicity considerations. By imposing very general Lipschitz-like conditions on the operators involved on the other hand by choosing our operators appropriately we can find sharper error bounds on the distances involved than before. Furthermore we show that special cases of our results reduce to the corresponding ones already in the literature. Finally our results are used to solve integral equations that cannot be solved with existing methods.

ON THE SEMILOCAL CONVERGENCE OF A NEWTON-TYPE METHOD OF ORDER THREE

  • Argyros, Ioannis K.;Hilout, Said
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제17권1호
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    • pp.1-27
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    • 2010
  • Wu and Zhao [17] provided a semilocal convergence analysis for a Newton-type method on a Banach space setting following the ideas of Frontini and Sormani [9]-[11]. In this study first: we point out inconsistencies between the hypotheses of Theorem 1 and the two examples given in [17], and then, we provide the proof in affine invariant form for this result. Then, we also establish new convergence results with the following advantages over the ones in [17]: weaker hypotheses, and finer error estimates on the distances involved. A numerical example is also provided to show that our results apply in cases other fail [17].

3D NEWTON 운동과 짐볼 운동이 요부 근력 및 근지구력에 미치는 영향 (The Effect of 3D NEWTON Exercise on Lumbar Strength and Endurance)

  • 서현규;김종우;황병준
    • 대한정형도수물리치료학회지
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    • 제17권2호
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    • pp.33-39
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    • 2011
  • Background: The purpose of this study was to verify the most effective spinal stabilization exercise program by comparing the activities of muscles contributing to spinal stabilization during 2 types of exercises using 3-D NEWTON and a Gym-ball. Methods: We divided sixteen healthy students to two groups in D city were recruited and each subjects performed two type of exercise. Exercise 1 was performed 3-D NEWTON spinal stabilization training during 4 weeks (n=8). Exercise 2 was performed special training program that use a Gym-ball during 4 weeks (n=8). Results: The group of 3-D NEWTON applying lumbar stabilization kinetic program was increased 18.8s after training. Conclusions: It was revealed the statically significant difference between 3-D NEWTON and Gym-ball lumbar stabilization exercise groups. Therefore it has been turned out that 3-D NEWTON and Gym-ball lumbar stabilization exercise has an effect on the abdominis and trunk muscle strengthening and balance.

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CHEYSHEFF-HALLEY-LIKE METHODS IN BANACH SPACES

  • Argyros, Ioannis-K.
    • Journal of applied mathematics & informatics
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    • 제4권1호
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    • pp.83-108
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    • 1997
  • Chebysheff-Halley methods are probably the best known cubically convergent iterative procedures for solving nonlinear equa-tions. These methods however require an evaluation of the second Frechet-derivative at each step which means a number of function eval-uations proportional to the cube of the dimension of the space. To re-duce the computational cost we replace the second Frechet derivative with a fixed bounded bilinear operator. Using the majorant method and Newton-Kantorovich type hypotheses we provide sufficient condi-tions for the convergence of our method to a locally unique solution of a nonlinear equation in Banach space. Our method is shown to be faster than Newton's method under the same computational cost. Finally we apply our results to solve nonlinear integral equations appearing in radiative transfer in connection with the problem of determination of the angular distribution of the radiant-flux emerging from a plane radiation field.

Comparison of Parameter Estimation for Weibull Distribution

  • Wang, Fu-Kwun;J. Bert Keats;B. Y. Leu
    • International Journal of Reliability and Applications
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    • 제4권1호
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    • pp.41-50
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    • 2003
  • This paper represents the first comprehensive comparison of the Newton-Raphson's method and Simple Iterative Procedure (SIP) in the maximum likelihood estimation of the two-parameter Weibull distribution. Computer simulation is employed to compare these two methods for multiply censored, singly censored data (Type I or Type Ⅱ censoring) and complete data. Results indicate the Newton-Raphson's with the Menon's estimated value, as an initial point remains the effective iterative procedure for estimating the parameters.

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