• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.525-537
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• 2005

We introduce the notions of regular preopen sets and $p^{\ast}-closed$ spaces and investigate some of these properties. Also we give a characterization of p-closed spaces.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.4
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• pp.569-573
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• 2010

We introduce the concept of fuzzy r-minimal preopen set on a fuzzy minimal space. We also introduce the concept of fuzzy r-M precontinuous mapping which is a generalization of fuzzy r-M continuous mapping, and investigate characterization of fuzzy r-M precontinuity.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.725-736
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• 2009

We define a (${\tau}_i$, ${\tau}_j$)-fuzzy strongly preopen set on a fuzzy bitopological space and characterize a fuzzy pairwise strong precontinuous mapping and a fuzzy pairwise strong preopen mapping(a fuzzy pairwise strong preclosed mapping) on a fuzzy bitopological space.

• Honam Mathematical Journal
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• v.32 no.2
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• pp.307-331
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• 2010

The notion of intuitionistic fuzzy semi-pre interior (semi-pre closure) is introduced, and several related properties are investigated. Characterizations of an intuitionistic fuzzy regular open set, an intuitionistic fuzzy semi-open set and an intuitionistic fuzzy ${\gamma}$-open set are provided. A method to make an intuitionistic fuzzy regular open set (resp. intuitionistic fuzzy regular closed set) is established. A relation between an intuitionistic fuzzy ${\gamma}$-open set and an intuitionistic fuzzy semi-preopen set is considered. A condition for an intuitionistic fuzzy set to be an intuitionistic fuzzy ${\gamma}$-open set is discussed.

• East Asian mathematical journal
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• v.22 no.2
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• pp.131-149
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• 2006

In this paper we introduce the concept of $\gamma$-preopen sets in a topological space together with its corresponding $\gamma$-preclosure and $\gamma$-preinterior operators and a new class of topology $\tau_{{\gamma}p}$ which is generated by the class of $\gamma$-preopen sets. Also we introduce $\gamma$-pre $T_i$ spaces(i=0, $\frac{1}{2}$, 1, 2) and study some of its properties and we proved that if $\gamma$ is a regular operation, then$(X,\;{\tau}_{{\gamma}p})$ is a $\gamma$-pre $T\frac{1}{2}$ space. Finally we introduce $(\gamma,\;\beta)$-precontinuous mappings and study some of its properties.

• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.467-474
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• 2005

Using the notion of intuitionistic fuzzy sets, the concept of intuitionis tic fuzzy semi-preopen sets and intuitionistic fuzzy semi-pre-continuous mappings are introduced. The relation between an intuitionistic fuzzy precontinuous ma pping and an intuitionistic semi-precontinuous mapping is given. Characterizations of intuitionistic fuzzy semi-preopen sets and intuitionist ic fuzzy semi-precontinuous mappings are given.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.179-182
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• 2007

In this paper, we introduce the concepts of fuzzy (r, s)-semi-preopen sets and fuzzy (r, s)-semi-precontinuous maps on intuitionistic fuzzy topological spaces in Sostak's sense. The relations among fuzzy (r, s)-semicontinuous, fuzzy (r, s)-precontinuous, and fuzzy (r, s)-semi-precontinuous maps are discussed. The concepts of fuzzy (r, s)-semi-preinterior, fuzzy (r, s)-semi-preclosure, fuzzy (r, s)-semi-preneighborhood, and fuzzy (r, s)-quasi-semi-preneighborhood are given. Using these concepts, the characterization for the fuzzy (r, s)-semi-precontinuous map is obtained. Also, we introduce the notions of fuzzy (r, s)-semi-preopen and fuzzy (r, s)-semi-preclosed maps on intuitionistic fuzzy topological spaces in Sostak's sense, and then we investigate some of their characteristic properties.

• Honam Mathematical Journal
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• v.28 no.2
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• pp.241-259
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• 2006

Using the concept of interval-valued fuzzy (IVF) sets, the notions of IVF semiopen (semiclosed) sets, IVF preopen (preclosed) sets and IVF $\alpha$-open ($\alpha$-closed) sets are introduced, and interrelations are investigated. Also, the concepts of IVF open mappings, IVF preopen mappings, IVF semiopen mappings and IVF $\alpha$-open mappings are introduced, and interrelations are discussed.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.550-556
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• 2007

In this paper, we introduce the concepts of fuzzy (r, s)-semi-preopen sets and fuzzy (r, s)-semi-precontinuous mappings on intuitionistic fuzzy topological spaces in ${\check{S}}ostak's$ sense. The relations among fuzzy (r, s)-semicontinuous, fuzzy (r, s)-precontinuous, and fuzzy (r, s)-semi-precontinuous mappings we discussed. The concepts of fuzzy (r, s)-semi-preinterior, fuzzy (r, s)-semi-preclosure, fuzzy (r, s)-semi-preneighborhood, and fuzzy (r, s)-quasi-semi-preneighborhood are given. Using these concepts, the characterization for the fuzzy (r, s)-semi-precontinuous mapping is obtained. Also, we introduce the notions of fuzzy (r, s)-semi-preopen and fuzzy (r, s)-semi-preclosed mappings on intuitionistic fuzzy topological spaces in ${\check{S}}ostak's$ sense, and then we investigate some of their characteristic properties.

• Honam Mathematical Journal
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• v.29 no.2
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• pp.223-244
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• 2007

We introduce the notions of interval-valued fuzzy semipreopen sets (mappings), interval-valued fuzzy semi-pre interior and interval-valued fuzzy semi-pre-continuous mappings by using the notion of interval-valued fuzzy sets. We also investigate related properties and characterize interval-valued fuzzy semi-preopen sets (mappings) and interval-valued fuzzy semi-precontinuous mappings.