• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.213-218
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• 1998

In this paper, we define and study another various generalizations of fuzzy continuous functions by using the concept of regular generalized fuzzy closed sets, A comparative study regarding the mutual interrelations among these functions along with those functions obtained in [3] is made. Finally, we have introduced and studied the notions of rgf-extremally disconnectedness and rgf-compactness

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.129-130
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• 2008

In this paper, we introduce the concept of generalized fuzzy (r,s)-closed sets on intuitionistic fuzzy topological spaces in ${\v{S}ostak's$ sense. Using this concept, we introduce the notions of generalized fuzzy (r,s)-continuous mappings, and then we investigate some of their properties.

• Kyungpook Mathematical Journal
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• v.45 no.1
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• pp.13-19
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• 2005

In this paper we introduce the notions of g-regularity and g-normality in fuzzy topological spaces. We obtain some characterizations and several preservation theorems of such spaces.

• Kyungpook Mathematical Journal
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• v.45 no.4
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• pp.539-547
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• 2005

The class of b-open sets in the sense of $Andrijevi{\acute{c}}$ ([3]), was discussed by El-Atik ([9]) under the name of ${\gamma}-open$ sets. This class is closed under arbitrary union. The aim of this paper is to use ${\Lambda}-sets$ and ${\vee}-sets$ due to Maki ([15]) some topologies are constructed with the concept of b-open sets. $b-{\Lambda}-sets,\;b-{\vee}-sets$ are the basic concepts introduced and investigated. Moreover, several types of near continuous function based on $b-{\Lambda}-sets,\;b-{\vee}-sets$ are constructed and studied.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.369-373
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• 1995

We introduce the concepts of generalized closed fuzzy set(breifly g-closed fuzzy set) and generalized fuzzy continuity (briefly g-fuzzy continuity), and investigate their some properties. When A is a fuzzy set in a fuzzy topological space, we denote the closure of A, the interior of A and the complement of A as CA(a) and CA, respectively

• Kyungpook Mathematical Journal
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• v.20 no.2
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• pp.169-175
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• 1980

• Kyungpook Mathematical Journal
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• v.33 no.2
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• pp.211-219
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• 1993

• Communications of the Korean Mathematical Society
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• v.25 no.3
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• pp.457-475
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• 2010

In this paper, we have use a fuzzy bitopological space (X, $\tau_1$, $\tau_2$) to create a family $\tau_{ij}^s$ which is a supra fuzzy topology on X. Also, we introduce and study the concepts of r-($\tau_i$, $\tau_j$)-generalized fuzzy regular closed, r-($\tau_i$, $\tau_j$)-generalized fuzzy strongly semi-closed and r-($\tau_i$, $\tau_j$)-generalized fuzzy regular strongly semi-closed sets in fuzzy bitopological space in the sense of $\check{S}$ostak. Also, these classes of fuzzy subsets are applied for constructing several type of fuzzy closed mapping and some type of fuzzy separation axioms called fuzzy binormal, fuzzy mildly binormal and fuzzy almost pairwise normal.

• Communications of the Korean Mathematical Society
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• v.18 no.2
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• pp.325-340
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• 2003

We introduce a fuzzy g-closure operator induced by a fuzzy topological space in view of the definition of Sostak [13]. We show that it is a fuzzy closure operator. Furthermore, it induces a fuzzy topology which is finer than a given fuzzy topology. We investigate some properties of fuzzy g-closure operators.

• The Pure and Applied Mathematics
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• v.25 no.1
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• pp.49-57
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• 2018

We have introduced two new notions of convexity and closedness in functional analysis. Let X be a real normed space, then $C({\subseteq}X)$ is functionally convex (briefly, F-convex), if $T(C){\subseteq}{\mathbb{R}}$ is convex for all bounded linear transformations $T{\in}B$(X, R); and $K({\subseteq}X)$ is functionally closed (briefly, F-closed), if $T(K){\subseteq}{\mathbb{R}}$ is closed for all bounded linear transformations $T{\in}B$(X, R). By using these new notions, the Alaoglu-Bourbaki-Eberlein-${\check{S}}muljan$ theorem has been generalized. Moreover, we show that X is reflexive if and only if the closed unit ball of X is F-closed. James showed that for every closed convex subset C of a Banach space X, C is weakly compact if and only if every $f{\in}X^{\ast}$ attains its supremum over C at some point of C. Now, we show that if A is an F-convex subset of a Banach space X, then A is bounded and F-closed if and only if every element of $X^{\ast}$ attains its supremum over A at some point of A.