• Journal of the Chungcheong Mathematical Society
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• v.29 no.1
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• pp.165-170
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• 2016

Souza and Tozatti [7] introduce the notions of prolongations and prolongational limit sets on control systems. In this article, we prove the upper semicontinuity of first positive prolongations and first positive prolongational limit sets on control systems.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.2
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• pp.229-253
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• 2016

As a generalization of (i, j)-weakly m-continuous functions [43], we introduce the notion of weakly M(i, j)-continuous functions and obtain many characterizations and some properties of the functions. We show that the function is a unified form of some functions between m-spaces and certain kinds of weakly continuous functions in bitopological spaces.

• Communications of the Korean Mathematical Society
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• v.18 no.1
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• pp.59-63
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• 2003

Let A be a $C^*$-algebra and $K_{A}$ its Pedersen's ideal. A is called a PCS-algebra if the multiplier $\Gamma(K_{A})\;of\;K_{A}$ is the multiplier M(A) of A. J. Mack [5]characterized PCS-algebras by weak compactness on the spectrum of A. We give a new simple proof of this Mack's result using the concept of semicontinuity and N. C. Phillips' description of $\Gamma(K_{A})$.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.200-205
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• 2003

In this paper, we generally introduce some of the terminology of Yalvac [10] and Azad [4] in intuitionistic fuzzy topological spaces. In addition to the fundamental concepts of intuitionistic fuzzy sets, we emphasize the usefulness of the concepts of intuitionistic fuzzy points intuitionistic fuzzy elementhood. Mainly, this paper is devoted to the study of intuitionistic fuzzy topological spaces with specific attention to the weaker forms of fuzzy continuity.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.98-101
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• 2000

The aim of this paper is to study and find characterizations of fuzzy quasi-semicontinuous and fuzzy quasi-semiopen mappings between fuzzy bitopological spaces. The notion of fuzzy quasi-semiopen sets is used to define fuzzy quasi-semicontinuous and fuzzy quasi-semiopen mappings. Finally, fuzzy quasi-semiconnectedness is introduced and studied to some extent.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.2
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• pp.111-115
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• 2008

By generalizing the definition of fuzzy weakly semicontinuous mappings by B. S. Zhong, we introduce the concept of fuzzy weakly r-semicontinuous mappings in fuzzy topology of Chattopadhyay. Then the concept introduced by B. S. Zhong becomes a special case of our definition. Also, we show that fuzzy weakly r-semicontinuity and fuzzy weakly r-continuity are independent notions.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.149-152
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• 2006

By generalizing the definition of B. S. Zhong, we introduce the concept of fuzzy weakly ${\gamma}-semicontinuous$ maps in fuzzy topology of Chattopadhyay. Then the concept introduced by B. S. Zhong become special case of our definition. Also, we show that fuzzy weakly ${\gamma}-semicontinuity$ and fuzzy weakly ${\gamma}-continuity$ are independent notions.

• Nonlinear Functional Analysis and Applications
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• v.27 no.1
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• pp.83-97
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• 2022

In this paper, we introduce and study generalized mixed operator quasi-equilibrium problems(GMQOEP) in Hausdorff topological vector spaces and prove the existence results for the solution of (GMQOEP) in compact and noncompact settings by employing 1-person game theorems. Moreover, using coercive condition, hemicontinuity of the functions and KKM theorem, we prove new results on the existence of solution for the particular case of (GMQOEP), that is, generalized mixed operator equilibrium problem (GMOEP).

• Journal of the Korean Mathematical Society
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• v.40 no.3
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• pp.487-501
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• 2003

The paper is devoted to the description of changes of the structure of the holomorphic automorphism group of a bounded domain in \mathbb{C}^n under small perturbation of this domain in the Hausdorff metric. We consider a number of examples when an arbitrary small perturbation can lead to a domain with a larger group, present theorems concerning upper semicontinuity property of some invariants of automorphism groups. We also prove that the dimension of an abelian subgroup of the automorphism group of a bounded domain in \mathbb{C}^n does not exceed n.