• Title/Summary/Keyword: weakly continuous

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STRONG CONVERGENCE OF COMPOSITE ITERATIVE METHODS FOR NONEXPANSIVE MAPPINGS

  • Jung, Jong-Soo
    • Journal of the Korean Mathematical Society
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    • v.46 no.6
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    • pp.1151-1164
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    • 2009
  • Let E be a reflexive Banach space with a weakly sequentially continuous duality mapping, C be a nonempty closed convex subset of E, f : C $\rightarrow$C a contractive mapping (or a weakly contractive mapping), and T : C $\rightarrow$ C a nonexpansive mapping with the fixed point set F(T) ${\neq}{\emptyset}$. Let {$x_n$} be generated by a new composite iterative scheme: $y_n={\lambda}_nf(x_n)+(1-{\lambda}_n)Tx_n$, $x_{n+1}=(1-{\beta}_n)y_n+{\beta}_nTy_n$, ($n{\geq}0$). It is proved that {$x_n$} converges strongly to a point in F(T), which is a solution of certain variational inequality provided the sequence {$\lambda_n$} $\subset$ (0, 1) satisfies $lim_{n{\rightarrow}{\infty}}{\lambda}_n$ = 0 and $\sum_{n=0}^{\infty}{\lambda}_n={\infty}$, {$\beta_n$} $\subset$ [0, a) for some 0 < a < 1 and the sequence {$x_n$} is asymptotically regular.

FAINTLY ${\gamma}$-CONTINUOUS FUNCTIONS

  • Min, Won-Keun
    • The Pure and Applied Mathematics
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    • v.17 no.2
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    • pp.145-150
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    • 2010
  • In this paper, we introduce the concepts of faintly ${\gamma}$-continuity and extremely ${\gamma}$-closed graph. And we study characterizations of such functions and relationships between faintly ${\gamma}$-continuity and extremely ${\gamma}$-closed graph.

Interval-Valued Fuzzy Almost α-Continuous Mappings (Interval-Valued Fuzzy Almost α-연속 함수의 연구)

  • Min, Won-Keun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.4
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    • pp.525-529
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    • 2011
  • We introduce the concept of IVF almost ${\alpha}$-continuity and investigate characterizations for such mappings on the interval-valued fuzzy topological spaces. We study the relationships between IVF almost ${\alpha}$-continuous mappings and another types of IVF continuous mappings.

On Fuzzy Almost r-minimal Continuous Functions between Fuzzy Minimal Spaces and Fuzzy Topological Spaces

  • Min, Won-Keun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.11 no.1
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    • pp.44-48
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    • 2011
  • The purpose of this paper is to introduce and investigate the concept of fuzzy almost r-minimal continuous function between fuzzy minimal spaces and fuzzy topological spaces. Particularly, we investigate characterizations for the fuzzy almost r-minimal continuity by using generalized fuzzy r-open sets.

AVERAGES AND COMPACT, ABSOLUTELY SUMMING AND NUCLEAR OPERATORS ON C (Ω)

  • Popa, Dumitru
    • Journal of the Korean Mathematical Society
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    • v.47 no.5
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    • pp.899-924
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    • 2010
  • In the paper we introduce averages of each type and use these averages to construct examples of weakly compact operators on the space C ($\Omega$) for which the necessary and sufficient conditions that they be compact, absolutely summing or nuclear are distinct. A great number of concrete examples, in various situations, are given.

ON SPACES IN WHICH COMPACT-LIKE SETS ARE CLOSED, AND RELATED SPACES

  • Hong, Woo-Chorl
    • Communications of the Korean Mathematical Society
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    • v.22 no.2
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    • pp.297-303
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    • 2007
  • In this paper, we study on C-closed spaces, SC-closed spaces and related spaces. We show that a sequentially compact SC-closed space is sequential and as corollaries obtain that a sequentially compact space with unique sequential limits is sequential if and only if it is C-closed [7, 1.19 Proposition] and every sequentially compact SC-closed space is C-closed. We also show that a countably compact WAP and C-closed space is sequential and obtain that a countably compact (or compact or sequentially compact) WAP-space with unique sequential limits is sequential if and only if it is C-closed as a corollary. Finally we prove that a weakly discretely generated AP-space is C-closed. We then obtain that every countably compact (or compact or sequentially compact) weakly discretely generated AP-space is $Fr\acute{e}chet$-Urysohn with unique sequential limits, for weakly discretely generated AP-spaces, unique sequential limits ${\equiv}KC{\equiv}C-closed{\equiv}SC-closed$, and every continuous surjective function from a countably compact (or compact or sequentially compact) space onto a weakly discretely generated AP-space is closed as corollaries.