• Title/Summary/Keyword: convex space

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ASYMPTOTIC PROPERTIES OF NONEXPANSIVE SEQUENCES IN BANACH SPACES

  • Park, Jong An;Park, Yang Seob
    • Korean Journal of Mathematics
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    • v.8 no.2
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    • pp.121-126
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    • 2000
  • B.Djafari Rouhani and W.A.Kirk [3] proved the following theorem: Let Xbe a reflexive Banach space and $(x_n)_{n{\geq}0}$ be a nonexpansive (resp., firmly nonexpansive )sequence in X. Then the set of weak ${\omega}$-limit points of the sequence $(\frac{x_n}{n})_{n{\geq}1}$(resp., $(x_{n+1}-x_n)_{n{\geq}0$) always lies on a convex subset of a sphere centered at the origin of radius $d={\lim}_{n{\rightarrow}{\infty}}\frac{{\parallel}x_n{\parallel}}{n}$. In this paper we show that the above theorem for nonexpansive(resp., firmly nonexpansive) sequences holds in a general Banach space(resp., a strictly convex dual $X^*$).

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CONVERGENCE OF APPROXIMATING FIXED POINTS FOR NONEXPANSIVE NONSELF-MAPPINGS IN BANACH SPACES

  • Jung, Jong-Soo;Park, Jong-Seo;Park, Eun-Hee
    • Communications of the Korean Mathematical Society
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    • v.12 no.2
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    • pp.275-285
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    • 1997
  • Let E be a uniformly convex Banach space with a uniformly G$\hat{a}teaux differentiable norm, C a nonempty closed convex subset of $E, T : C \to E$ a nonexpansive mapping, and Q a sunny nonexpansive retraction of E onto C. For $u \in C$ and $t \in (0,1)$, let $x_t$ be a unique fixed point of a contraction $R_t : C \to C$, defined by $R_tx = Q(tTx + (1-t)u), x \in C$. It is proved that if ${x_t}$ is bounded, then the strong $lim_{t\to1}x_t$ exists and belongs to the fixed point set of T. Furthermore, the strong convergence of ${x_t}$ in a reflexive and strictly convex Banach space with a uniformly G$\hat{a}$teaux differentiable norm is also given in case that the fixed point set of T is nonempty.

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PETTIS CONDITIONAL EXPECTATION OF CLOSED CONVEX RANDOM SETS IN A BANACH SPACE WITHOUT RNP

  • Akhiat, Fattah;El Harami, Mohamed;Ezzaki, Fatima
    • Journal of the Korean Mathematical Society
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    • v.55 no.4
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    • pp.833-848
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    • 2018
  • In this paper we study the existence of conditional expectation for closed and convex valued Pettis-integrable random sets without assuming the Radon Nikodym property of the Banach space. New version of multivalued dominated convergence theorem of conditional expectation and multivalued $L{\acute{e}}vy^{\prime}s$ martingale convergence theorem for integrable and Pettis integrable random sets are proved.

Efficient algorithm for planning collision free path among polyhedral obstacles

  • Habib, Maki-K.;Asama, Hajime
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.1004-1008
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    • 1990
  • This research focuses on developing a new and computationally efficient algorithm for free space structuring and planning collision free paths for an autonomous mobile robot working in an environment populated with polygonal obstacles. The algorithm constructs the available free space between obstacles in terms of free convex area. A collision free path can be efficiently generated based on a graph constructed using the midpoints of common free links between free convex area as passing points. These points correspond to nodes in a graph and the connection between them within each convex area as arcs in this graph. The complexity of the search for collision free path is greatly reduced by minimizing the size of the graph to be searched concerning the number of nodes and the number of arcs connecting them. The analysis of the proposed algorithm shows its efficiency in terms of computation ability, safety and optimality.

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INCLUSION AND INTERSECTION THEOREMS WITH APPLICATIONS IN EQUILIBRIUM THEORY IN G-CONVEX SPACES

  • Balaj, Mircea;O'Regan, Donal
    • Journal of the Korean Mathematical Society
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    • v.47 no.5
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    • pp.1017-1029
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    • 2010
  • In this paper we obtain a very general theorem of $\rho$-compatibility for three multivalued mappings, one of them from the class $\mathfrak{B}$. More exactly, we show that given a G-convex space Y, two topological spaces X and Z, a (binary) relation $\rho$ on $2^Z$ and three mappings P : X $\multimap$ Z, Q : Y $\multimap$ Z and $T\;{\in}\;\mathfrak{B}$(Y,X) satisfying a set of conditions we can find ($\widetilde{x},\;\widetilde{y}$) ${\in}$ $X\;{\times}\;Y$ such that $\widetilde{x}\;{\in}\;T(\widetilde{y})$ and $P(\widetilde{x}){\rho}\;Q(\widetilde{y})$. Two particular cases of this general result will be then used to establish existence theorems for the solutions of some general equilibrium problems.

Multiple Face Segmentation and Tracking Based on Robust Hausdorff Distance Matching

  • Park, Chang-Woo;Kim, Young-Ouk;Sung, Ha-Gyeong;Park, Mignon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.87-92
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    • 2003
  • This paper describes a system for tracking multiple faces in an input video sequence using facial convex hull based facial segmentation and robust hausdorff distance. The algorithm adapts skin color reference map in YCbCr color space and hair color reference map in RGB color space for classifying face region. Then, we obtain an initial face model with preprocessing and convex hull. For tracking, this algorithm computes displacement of the point set between frames using a robust hausdorff distance and the best possible displacement is selected. Finally, the initial face model is updated using the displacement. We provide an example to illustrate the proposed tracking algorithm, which efficiently tracks rotating and zooming faces as well as existing multiple faces in video sequences obtained from CCD camera.

INVARIANT OPEN SETS UNDER COCOMPACT AFFINE ACTIONS

  • Park, Kyeong-Su
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.1
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    • pp.203-207
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    • 1999
  • In this paper, we find a condition of an open subset of the affine space which admits a cocompact affine action. To do it, the asymptotic flag of an open convex subset is introduced and some applications to affine manifolds are presented.

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A THREE-TERM INERTIAL DERIVATIVE-FREE PROJECTION METHOD FOR CONVEX CONSTRAINED MONOTONE EQUATIONS

  • Noinakorn, Supansa;Ibrahim, Abdukarim Hassan;Abubakar, Auwal Bala;Pakkaranang, Nuttapol
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.4
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    • pp.839-853
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    • 2021
  • Let 𝕽n be an Euclidean space and g : 𝕽n → 𝕽n be a monotone and continuous mapping. Suppose the convex constrained nonlinear monotone equation problem x ∈ 𝕮 s.t g(x) = 0 has a solution. In this paper, we construct an inertial-type algorithm based on the three-term derivative-free projection method (TTMDY) for convex constrained monotone nonlinear equations. Under some standard assumptions, we establish its global convergence to a solution of the convex constrained nonlinear monotone equation. Furthermore, the proposed algorithm converges much faster than the existing non-inertial algorithm (TTMDY) for convex constrained monotone equations.