• Title/Summary/Keyword: monotone method

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Efficient Algorithms for Approximating the Centroids of Monotone Directions in a Polyhedron

  • Ha, Jong-Sung;Yoo, Kwan-Hee
    • International Journal of Contents
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    • v.12 no.2
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    • pp.42-48
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    • 2016
  • We present efficient algorithms for computing centroid directions for each of the three types of monotonicity in a polyhedron: strong, weak, and directional monotonicity, which can be used for optimizing directions in many 3D manufacturing processes. Strongly- and directionally-monotone directions are the poles of great circles separating a set of spherical polygons on the unit sphere, the centroids of which are shown to be obtained by applying the previous result for determining the maximum intersection of the set of their dual spherical polygons. Especially in this paper, we focus on developing an efficient method for approximating the weakly-monotone centroid, which is the pole of one of the great circles intersecting a set of spherical polygons on the unit sphere. The original problem is approximately reduced into computing the intersection of great bands for avoiding complicated computational complexity of non-convex objects on the unit sphere, which can be realized with practical linear-time operations.

ON A QUADRATICALLY CONVERGENT ITERATIVE METHOD USING DIVIDED DIFFERENCES OF ORDER ONE

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.14 no.3
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    • pp.203-221
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    • 2007
  • We introduce a new two-point iterative method to approximate solutions of nonlinear operator equations. The method uses only divided differences of order one, and two previous iterates. However in contrast to the Secant method which is of order 1.618..., our method is of order two. A local and a semilocal convergence analysis is provided based on the majorizing principle. Finally the monotone convergence of the method is explored on partially ordered topological spaces. Numerical examples are also provided where our results compare favorably to earlier ones [1], [4], [5], [19].

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AN ITERATIVE METHOD FOR EQUILIBRIUM PROBLEMS, VARIATIONAL INEQUALITY PROBLEMS AND FIXED POINT PROBLEMS

  • Shang, Meijuan;Su, Yongfu
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.161-173
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    • 2009
  • In this paper, we introduce an iterative scheme for finding a common element of the set of fixed points of a nonexpansive mapping, the set of solutions of the variational inequality for an inverse-strongly monotone mapping and the set of solutions of an equilibrium problem in a Hilbert space. We show that the iterative sequence converges strongly to a common element of the three sets. The results of this paper extend and improve the corresponding results announced by many others.

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SOLUTIONS OF SYSTEMS OF VARIATIONAL INEQUALITIES ON FIXED POINTS OF NONEXPANSIVE MAPPINGS

  • Piri, Hossein
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.3
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    • pp.621-640
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    • 2014
  • In this paper, we introduce a new approximating method for finding the common element of the set of fixed points of nonexpansive mappings and the set of solution of system variational inequalities for finite family of inverse strongly monotone mappings and strictly pseudo-contractive of Browder-Petryshyn type mappings. We show that the sequence converges strongly to a common element the above two sets under some parameter controling conditions. Our results improve and extend the results announced by many others.

STRONG CONVERGENCE OF AN EXTENDED EXTRAGRADIENT METHOD FOR EQUILIBRIUM PROBLEMS AND FIXED POINT PROBLEMS

  • Kim, Jong-Kyu;Anh, Pham Ngoc;Nam, Young-Man
    • Journal of the Korean Mathematical Society
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    • v.49 no.1
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    • pp.187-200
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    • 2012
  • In this paper, we introduced a new extended extragradient iteration algorithm for finding a common element of the set of fixed points of a nonexpansive mapping and the set of solutions of equilibrium problems for a monotone and Lipschitz-type continuous mapping. And we show that the iterative sequences generated by this algorithm converge strongly to the common element in a real Hilbert space.

AN ITERATIVE METHOD FOR SOLVING EQUILIBRIUM PROBLEM FIXED POINT PROBLEM AND GENERALIZED VARIATIONAL INEQUALITIES PROBLEM

  • Zhang, Lijuan;Li, Juchun
    • East Asian mathematical journal
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    • v.27 no.5
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    • pp.527-538
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    • 2011
  • In this paper, we introduce a new iterative scheme for finding a common element of the set of an equilibrium problem, the set of fixed points of nonexpansive mapping and the set of solutions of the generalized variational inequality for ${\alpha}$-inverse strongly g-monotone mapping in a Hilbert space. Under suitable conditions, strong convergence theorems for approximating a common element of the above three sets are obtained.

EXISTENCE AND UNIQUENESS RESULTS FOR SYSTEM OF FRACTIONAL DIFFERENTIAL EQUATIONS WITH INITIAL TIME DIFFERENCE

  • Nanware, J.A.;Dawkar, B.D.;Panchal, M.S.
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.5
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    • pp.1035-1044
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    • 2021
  • Existence and uniqueness results for solutions of system of Riemann-Liouville (R-L) fractional differential equations with initial time difference are obtained. Monotone technique is developed to obtain existence and uniqueness of solutions of system of R-L fractional differential equations with initial time difference.

THE ITERATION METHOD OF SOLVING A TYPE OF THREE-POINT BOUNDARY VALUE PROBLEM

  • Liu, Xiping;Jia, Mei
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.475-487
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    • 2009
  • This paper studies the iteration method of solving a type of second-order three-point boundary value problem with non-linear term f, which depends on the first order derivative. By using the upper and lower method, we obtain the sufficient conditions of the existence and uniqueness of solutions. Furthermore, the monotone iterative sequences generated by the method contribute to the minimum solution and the maximum solution. And the error estimate formula is also given under the condition of unique solution. We apply the solving process to a special boundary value problem, and the result is interesting.

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ON THE PROXIMAL POINT METHOD FOR AN INFINITE FAMILY OF EQUILIBRIUM PROBLEMS IN BANACH SPACES

  • Khatibzadeh, Hadi;Mohebbi, Vahid
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.3
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    • pp.757-777
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    • 2019
  • In this paper, we study the convergence analysis of the sequences generated by the proximal point method for an infinite family of pseudo-monotone equilibrium problems in Banach spaces. We first prove the weak convergence of the generated sequence to a common solution of the infinite family of equilibrium problems with summable errors. Then, we show the strong convergence of the generated sequence to a common equilibrium point by some various additional assumptions. We also consider two variants for which we establish the strong convergence without any additional assumption. For both of them, each iteration consists of a proximal step followed by a computationally inexpensive step which ensures the strong convergence of the generated sequence. Also, for this two variants we are able to characterize the strong limit of the sequence: for the first variant it is the solution lying closest to an arbitrarily selected point, and for the second one it is the solution of the problem which lies closest to the initial iterate. Finally, we give a concrete example where the main results can be applied.

Automatic Prostate Segmentation from Ultrasound Images using Morphological Features (형태학적 특징을 이용한 초음파 영상에서의 자동 전립선 분할)

  • Kim, Kwang Baek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.6
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    • pp.865-871
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    • 2022
  • In this paper, we propose a method of extracting prostate region using morphological characteristics of ultra-sonic image of prostate. In the first step of the proposed method, the edge area of the prostate image is extracted. The histogram of ultra-sonic image is used to extract base objects to detect the upper edge of prostate region by altering the contrast of the image, then, the lower edges of the extracted base objects are connected by using monotone cubic spline interpolation to extract the upper edge. Step 2, Otsu's binarization is applied to the region under the extracted upper edge of the prostate ultra-sonic image to extract the lower edge of prostate. In the last step, the upper and the lower edges are connected to extract prostate region and by comparing the extracted region of prostate with the one measured manually, the result showed that the morphological characteristics of prostate in ultrasonic image can be utilized to extract the prostate region.