• Title/Summary/Keyword: ${\kappa}$-spaces

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STRONG VERSIONS OF κ-FRÉCHET AND κ-NET SPACES

  • CHO, MYUNG HYUN;KIM, JUNHUI;MOON, MI AE
    • Honam Mathematical Journal
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    • v.37 no.4
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    • pp.549-557
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    • 2015
  • We introduce strongly ${\kappa}$-$Fr{\acute{e}}chet$ and strongly ${\kappa}$-sequential spaces which are stronger than ${\kappa}$-$Fr{\acute{e}}chet$ and ${\kappa}$-net spaces respectively. For convenience, we use the terminology "${\kappa}$-sequential" instead of "${\kappa}$-net space", introduced by R.E. Hodel in [5]. And we study some properties and topological operations on such spaces. We also define strictly ${\kappa}$-$Fr{\acute{e}}chet$ and strictly ${\kappa}$-sequential spaces which are more stronger than strongly ${\kappa}$-$Fr{\acute{e}}chet$ and strongly ${\kappa}$-sequential spaces respectively.

SATURATED STRUCTURES FROM PROBABILITY THEORY

  • Song, Shichang
    • Journal of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.315-329
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    • 2016
  • In the setting of continuous logic, we study atomless probability spaces and atomless random variable structures. We characterize ${\kappa}$-saturated atomless probability spaces and ${\kappa}$-saturated atomless random variable structures for every infinite cardinal ${\kappa}$. Moreover, ${\kappa}$-saturated and strongly ${\kappa}$-homogeneous atomless probability spaces and ${\kappa}$-saturated and strongly ${\kappa}$-homogeneous atomless random variable structures are characterized for every infinite cardinal ${\kappa}$. For atomless probability spaces, we prove that ${\aleph}_1$-saturation is equivalent to Hoover-Keisler saturation. For atomless random variable structures whose underlying probability spaces are Hoover-Keisler saturated, we prove several equivalent conditions.

A STUDY ON κ-AP, κ-WAP SPACES AND THEIR RELATED SPACES

  • Cho, Myung Hyun;Kim, Junhui
    • Honam Mathematical Journal
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    • v.39 no.4
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    • pp.655-663
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    • 2017
  • In this paper we define $AP_c$ and $AP_{cc}$ spaces which are stronger than the property of approximation by points(AP). We investigate operations on their subspaces and study function theorems on $AP_c$ and $AP_{cc}$ spaces. Using those results, we prove that every continuous image of a countably compact Hausdorff space with AP is AP. Finally, we prove a theorem that every compact ${\kappa}$-WAP space is ${\kappa}$-pseudoradial, and prove a theorem that the product of a compact ${\kappa}$-radial space and a compact ${\kappa}$-WAP space is a ${\kappa}$-WAP space.

A STRONG UNIFORM BOUNDEDNESS RESULT ON κ-SPACES

  • Cho, Min-Hyung
    • Korean Journal of Mathematics
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    • v.4 no.1
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    • pp.1-5
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    • 1996
  • A strong Banach-Mackey property is established for ${\kappa}$-spaces including all complete and some non-complete metric linear spaces and some non-metrizable locally convex spaces. As applications of this result, a strong uniform boundedness result and a new Banach-Steinhaus type theorem are obtained.

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PRODUCT SPACE AND QUOTIENT SPACE IN K0-PROXIMITY SPACES

  • Han, Song Ho
    • Korean Journal of Mathematics
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    • v.10 no.1
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    • pp.59-66
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    • 2002
  • We introduce the ${\kappa}_0$-proximity space as a generalization of the Efremovic-proximity space. We define a product ${\kappa}_0$-proximity and the quotient ${\kappa}_0$-proxmity and show some properties of ${\kappa}_0$-proximity space.

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CONVERGENCE THEOREMS FOR GENERALIZED EQUILIBRIUM PROBLEMS AND ASYMPTOTICALLY κ-STRICT PSEUDO-CONTRACTIONS IN HILBERT SPACES

  • Liu, Ying
    • East Asian mathematical journal
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    • v.29 no.3
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    • pp.303-314
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    • 2013
  • In this paper, we introduce an iterative scheme for finding a common element of the set of solutions of a generalized equilibrium problem and the set of common fixed points of a finite family of asymptotically ${\kappa}$-strict pseudo-contractions in Hilbert spaces. Weak and strong convergence theorems are established for the iterative scheme.

SOME PROPERTIES AROUND 1½ STARCOMPACT SPACES

  • CHO, MYUNG HYUN;PARK, WON WOO
    • Honam Mathematical Journal
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    • v.24 no.1
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    • pp.131-142
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    • 2002
  • A $1{\frac{1}{2}}$-starcompact space has one of the most curious properties among the spaces of starcompactness. It is not too far away from countably compact spaces and may be considered as the first candidate for extending theorems about countably compact spaces. Unfortunately, $1{\frac{1}{2}}$-starcompactness is not so easy to be recognized as 2-starcompactness which will follow from countable pracompactness. We investigate some properties around $1{\frac{1}{2}}$-starcompact spaces.

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