• 제목/요약/키워드: nonexpansive mappings

검색결과 182건 처리시간 0.02초

STRONG CONVERGENCE OF AN IMPLICIT ITERATION PROCESS FOR A FINITE FAMILY OF STRONG SUCCESSIVELY $\Phi$-PSEUDOCONTRACTIVE MAPS

  • Chen, Rudong;Miao, Qian
    • East Asian mathematical journal
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    • 제24권1호
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    • pp.105-110
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    • 2008
  • The aim of this paper is to prove convergence of implicit iteration process to a common fixed point for a finite family of strong successive $\Phi$-pseudocontractive mappings. The results presented in this paper extend and improve the corresponding results of S. S. Chang [On the convergence of implicit iteration process with error for a finite family of asymptotically nonexpansive mappings, J. Math. Anal. Appl. 313(2006), 273-283], M. O. Osilike[Implicit iteration process for common fixed points of a finite finite family of strictly pseudocontractive maps, Appl. Math. Comput. 189(2) (2007), 1058-1065].

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On the Semi-threading of Knot Diagrams with Minimal Overpasses

  • Chung, Jae-Wook;Jeong, Seul-Gi;Kim, Dong-Seok
    • Kyungpook Mathematical Journal
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    • 제51권2호
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    • pp.205-215
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    • 2011
  • Given a knot diagram D, we construct a semi-threading circle of it which can be an axis of D as a closed braid depending on knot diagrams. In particular, we consider semi-threading circles of minimal diagrams of a knot with respect to overpasses which give us some information related to the braid index. By this notion, we try to give another proof of the fact that, for every nontrivial knot K, the braid index b(K) of K is not less than the minimum number l(K) of overpasses of diagrams. Also, they are the same for a torus knot.

HYBRID INERTIAL CONTRACTION PROJECTION METHODS EXTENDED TO VARIATIONAL INEQUALITY PROBLEMS

  • Truong, N.D.;Kim, J.K.;Anh, T.H.H.
    • Nonlinear Functional Analysis and Applications
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    • 제27권1호
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    • pp.203-221
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    • 2022
  • In this paper, we introduce new hybrid inertial contraction projection algorithms for solving variational inequality problems over the intersection of the fixed point sets of demicontractive mappings in a real Hilbert space. The proposed algorithms are based on the hybrid steepest-descent method for variational inequality problems and the inertial techniques for finding fixed points of nonexpansive mappings. Strong convergence of the iterative algorithms is proved. Several fundamental experiments are provided to illustrate computational efficiency of the given algorithm and comparison with other known algorithms

COMMON FIXED POINT AND INVARIANT APPROXIMATION RESULTS

  • Abbas, Mujahid;Kim, Jong-Kyu
    • 대한수학회보
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    • 제44권3호
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    • pp.537-545
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    • 2007
  • Necessary conditions for the existence of common fixed points for noncommuting mappings satisfying generalized contractive conditions in the setup of certain metrizable topological vector spaces are obtained. As applications, related results on best approximation are derived. Our results extend, generalize and unify various known results in the literature.

STRONG CONVERGENCE OF AN ITERATIVE ALGORITHM FOR SYSTEMS OF VARIATIONAL INEQUALITIES AND FIXED POINT PROBLEMS IN q-UNIFORMLY SMOOTH BANACH SPACES

  • Jeong, Jae Ug
    • Korean Journal of Mathematics
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    • 제20권2호
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    • pp.225-237
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    • 2012
  • In this paper, we introduce a new iterative scheme to investigate the problem of nding a common element of nonexpansive mappings and the set of solutions of generalized variational inequalities for a $k$-strict pseudo-contraction by relaxed extra-gradient methods. Strong convergence theorems are established in $q$-uniformly smooth Banach spaces.

COMMON FIXED POINT AND INVARIANT APPROXIMATION IN MENGER CONVEX METRIC SPACES

  • Hussain, Nawab;Abbas, Mujahid;Kim, Jong-Kyu
    • 대한수학회보
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    • 제45권4호
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    • pp.671-680
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    • 2008
  • Necessary conditions for the existence of common fixed points for noncommuting mappings satisfying generalized contractive conditions in a Menger convex metric space are obtained. As an application, related results on best approximation are derived. Our results generalize various well known results.

APPROXIMATING COMMON FIXED POINTS OF NONEXPANSIVE MAPPINGS IN BANACH SPACES

  • Kim, Tae-Hwa
    • Journal of applied mathematics & informatics
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    • 제5권3호
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    • pp.859-866
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    • 1998
  • In this paper we shall prove weak(or strong) convergence of the iterates ${\chi_n} \;and \;{y_n}$ defined by $\chi-{n+1}= \alpha_nTy_n+(1-\alpha_n)S\chi_n , y_n=\beta_nT\chi_n+(1-\beta_n)\chi_n$ for all n$\geq$1, where $\alpha_n$ and $\beta_n$ satisfy 0$\leq\alpha_n,\beta_n\leq$b<1.

Fixed Point Theorems for Multivalued Mappings in Banach Spaces

  • Bae, Jong Sook;Park, Myoung Sook
    • 충청수학회지
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    • 제3권1호
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    • pp.103-110
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    • 1990
  • Let K be a nonempty weakly compact convex subset of a Banach space X and T : K ${\rightarrow}$ C(X) a nonexpansive mapping satisfying $P_T(x){\cap}clI_K(x){\neq}{\emptyset}$. We first show that if I - T is semiconvex type then T has a fixed point. Also we obtain the same result without the condition that I - T is semiconvex type in a Banach space satisfying Opial's condition. Lastly we extend the result of [5] to the case, that T is an 1-set contraction mapping.

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PROJECTION METHODS FOR RELAXED COCOERCIVE VARIATION INEQUALITIES IN HILBERT SPACES

  • Su, Yongfu;Zhang, Hong
    • Journal of applied mathematics & informatics
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    • 제27권1_2호
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    • pp.431-440
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    • 2009
  • In this paper, we introduce and consider a new system of relaxed cocoercive variational inequalities involving three different operators and the concept of projective nonexpansive mapping. Base on the projection technique, we suggest two kinds of new iterative methods for the approximate solvability of this system. The results presented in this paper extend and improve the main results of [S.S. Chang, H.W.J. Lee, C.K. Chan, Generalized system for relaxed co coercive variational inequalities in Hilbert spaces, Appl. Math. Lett. 20 (2007) 329-334] and [Z. Huang, M. Aslam Noor, An explicit projection method for a system of nonlinear variational inequalities with different ($\gamma,r$)-cocoercive mappings, Appl. Math. Comput. (2007), doi:10.1016/j.amc.2007.01.032].

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CONVERGENCE OF APPROXIMATING PATHS TO SOLUTIONS OF VARIATIONAL INEQUALITIES INVOLVING NON-LIPSCHITZIAN MAPPINGS

  • Jung, Jong-Soo;Sahu, Daya Ram
    • 대한수학회지
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    • 제45권2호
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    • pp.377-392
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    • 2008
  • Let X be a real reflexive Banach space with a uniformly $G\hat{a}teaux$ differentiable norm, C a nonempty closed convex subset of X, T : C $\rightarrow$ X a continuous pseudocontractive mapping, and A : C $\rightarrow$ C a continuous strongly pseudocontractive mapping. We show the existence of a path ${x_t}$ satisfying $x_t=tAx_t+(1- t)Tx_t$, t $\in$ (0,1) and prove that ${x_t}$ converges strongly to a fixed point of T, which solves the variational inequality involving the mapping A. As an application, we give strong convergence of the path ${x_t}$ defined by $x_t=tAx_t+(1-t)(2I-T)x_t$ to a fixed point of firmly pseudocontractive mapping T.