• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.378-383
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• 1995

Kandil[5] introduced and studied the notion of fuzzy bitopological spaces as a natural generalization of fuzzy topological In [10], Sampath Kumar introduced and studied the concepts of ( i, j)-fuzzy semiopen sets, fuzzy pairwise semicontinuous mappings in the fuzzy bitopological spaces. Also, he defined the concepts of ( i, j)-fuzzy -open sets, ( i, j)-fuzzy preopen sets, fuzzy pairwise -continuous mappings and fuzzy pairwise precontinuous mappings in the fuzzy bitopological spaces and studied some of their basic properties. In this paper, we generalize the concepts of fuzzy -open sets, fuzzy -continous mappings ？ 새 Mashhour, Ghanim and Fata Alla[6] into fuzzy bitopological spaces, We first define the concepts of ( i, j)-fuzzy -open sets and then consider the generalizations of fuzzy pairwise -continuous mappings is obtained Besides many basic results, results related to products and graph of mapping are obtained in the fuzzy bitopological spaces.

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.145-154
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• 2019

The notion of hypercyclicity was localized by J-sets and in this paper, we will investigate for an equivalent condition through the use of open sets. Also, we will give a J-class criterion, that gives conditions under which an operator belongs to the J-class of operators.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.2
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• pp.119-123
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• 2010

We introduce and investigate the concepts of ($T_i,T_j$)-fuzzy $\beta$-(r, s)-open sets, ($T_i,T_j$)-fuzzy $\beta$-(r, s)-closed sets and fuzzy pairwise $\beta$-(r, s)-continuous mappings in smooth bitopological spaces.

• Bulletin of the Korean Mathematical Society
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• v.39 no.4
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• pp.653-663
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• 2002

We introduce and investigate the concepts of ($(T_i,T_j)$-fuzzy $\alpha-(r.s)$-semiopen $\alpha-(r.s)$-semiclosed) sets and fuzzy pairwise $\alpha-(r.s)$-semicontinuous mappings in smooth bitopological spaces.

• Journal of the Korean Mathematical Society
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• v.58 no.3
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• pp.741-760
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• 2021

In this paper, we exhibit the equivalence between different notions of unique range sets, namely, unique range sets, weighted unique range sets and weak-weighted unique range sets under certain conditions. Also, we present some uniqueness theorems which show how two meromorphic functions are uniquely determined by their two finite shared sets. Moreover, in the last section, we make some observations that help us to construct other new classes of unique range sets.

• Bulletin of the Korean Mathematical Society
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• v.53 no.4
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• pp.971-983
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• 2016

A partially ordered set P is ideal-homogeneous provided that for any ideals I and J, if $$I{\sim_=}_{\sigma}J$$, then there exists an automorphism ${\sigma}^*$ such that ${\sigma}^*{\mid}_I={\sigma}$. Behrendt [1] characterizes the ideal-homogeneous partially ordered sets of height 1. In this paper, we characterize the ideal-homogeneous partially ordered sets of height 2 and nd some families of ideal-homogeneous partially ordered sets.

• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.31-38
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• 1997

We figure out geometric properties of the Julia set $J_{\alpha}$ of cubic complex polynomial $C_{\alpha}(z)=z^3 + {\alpha}z(\alpha \epsilon \mathbb{C})$ and the smallest ellipse which surrounds $J_{\alpha}$.

• Language and Information
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• v.5 no.2
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• pp.1-8
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• 2001

Natural language string sets are known to require a grammar with a generative capacity slightly beyond that of Context Free Grammars. Proofs regarding complexity of natural language have involved particular properties of languages like English, Swiss German and Bambara. While it is not very difficult to prove that Korean is more complex than the simplest of the many infinite sets, no proof has been given of this in the literature. I identify two types of center embedding in Korean and use them in proving that Korean is not a regular set, i.e. that no FSA's can recognize its string set. The regular language i salam i (i salam ul$)^j$ michi (key ha)^k$ essta is intersected with Korean, to give {i salam i (i salam ul$)^j$ michi (key ha$)^k$ essta i $$\mid$$ j, k $\geq$ 0 and j $\leq$ k}. This latter language is proved to be nonregular. As the class of regular sets is closed under intersection, Korean cannot be regular.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.231-236
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• 1999

Accurate ocean surface fluxes with high resolution are critical for understanding a mechanism of global climate. However, it is difficult to derive those fluxes by using ocean observation data because the number of ocean observation data is extremely small and the distribution is inhomogeneous. On the other hand. satellite data are characterized by the high density, the high resolution and the homogeneity. Therefore, it can be considered that we obtain accurate ocean surface by using satellite data. Recently we constructed ocean surface data sets mainly using satellite data. The data set is named by Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO). Here, we introduce J-OFURO. The data set includes shortwave radiation, longwave radiation, latent heat flux, sensible heat flux, and momentum flux etc. Moreover, sea surface dynamic topography data are included in the data set. Radiation data sets covers western Pacific and eastern Indian Ocean because we use a Japanese geostationally satellite (GMS) to estimate radiation fluxes. On the other hand, turbulent heat fluxes are globally estimated. The constructed data sets are used and shows the effectiveness for many scientific studies.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.899-908
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• 2017

We call a sequence $(T_n)_n$ of bounded operators on a Banach space X, BSC-Sequence if it is a Cauchy sequence in the strong operator topology and is uniformly bounded below. We determine conditions under which such sequences has a fixed point.