• Korean Journal of Mathematics
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• v.13 no.1
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• pp.83-90
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• 2005

A.H.Hamel proved the Ekeland's principle in a locally convex Hausdorff topological vector spaces by constructing the norm and applying the Ekeland's principle in Banach spaces. In this paper we show that the Ekeland's principle in a locally convex Hausdorff topological vector spaces can be proved directly by applying the famous general principle of H.Br$\acute{e}$zis and F.E.Browder.

• Nonlinear Functional Analysis and Applications
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• v.24 no.1
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• pp.61-71
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• 2019

In this paper, we consider the generalized equilibrium problems with operator solutions and derive some existence results for generalized operator equilibrium problems in Hausdorff topological vector spaces by employing KKM theorem. The results presented of this paper generalize and unify the corresponding results of the several authors.

• The Pure and Applied Mathematics
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• v.10 no.4
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• pp.225-232
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• 2003

In this paper, we consider the existence of the solutions to the generalized vector variational-type inequalities for set-valued mappings on Hausdorff topological vector spaces using Fan's geometrical lemma.

• Bulletin of the Korean Mathematical Society
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• v.52 no.6
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• pp.1777-1795
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• 2015

In this paper, we establish sufficient conditions for the solution set of parametric generalized vector mixed quasivariational inequality problem to have the semicontinuities such as the inner-openness, lower semicontinuity and Hausdorff lower semicontinuity. Moreover, a key assumption is introduced by virtue of a parametric gap function by using a nonlinear scalarization function. Then, by using the key assumption, we establish condition ($H_h$(${\gamma}_0$, ${\lambda}_0$, ${\mu}_0$)) is a sufficient and necessary condition for the Hausdorff lower semicontinuity, continuity and Hausdorff continuity of the solution set for this problem in Hausdorff topological vector spaces with the objective space being infinite dimensional. The results presented in this paper are different and extend from some main results in the literature.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.2
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• pp.163-169
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• 2011

Recently, Kazmi and Khan [7] introduced a kind of equilibrium problem called generalized system (GS) with a single-valued bi-operator F. In this note, we aim at an extension of (GS) due to Kazmi and Khan [7] into a multi-valued circumstance. We consider a fairly general problem called the multi-valued quasi-generalized system (in short, MQGS). Based on the existence of 1-person game by Ding, Kim and Tan [5], we give a generalization of (GS) in the name of (MQGS) within the framework of Hausdorff topological vector spaces. As an application, we derive an existence result of the generalized vector quasi-variational inequality problem. This result leads to a multi-valued vector quasi-variational inequality extension of the strong vector variational inequality (SVVI) due to Fang and Huang [6] in a general Hausdorff topological vector space.

• Communications of the Korean Mathematical Society
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• v.32 no.4
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• pp.933-957
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• 2017

In this paper, we prove some existence results of solutions for a new class of generalized bi-quasi-variational-like inequalities (GBQVLI) for (${\eta}-h$)-quasi-pseudo-monotone type I and strongly (${\eta}-h$)-quasi-pseudo-monotone type I operators defined on non-compact sets in locally convex Hausdorff topological vector spaces. To obtain our results on GBQVLI for (${\eta}-h$)-quasi-pseudo-monotone type I and strongly (${\eta}-h$)-quasi-pseudo-monotone type I operators, we use Chowdhury and Tan's generalized version of Ky Fan's minimax inequality as the main tool.

• Nonlinear Functional Analysis and Applications
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• v.29 no.3
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• pp.825-839
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• 2024

A new type of more general form of variational inequalities for quasi-pseudo-monotone type III and strong quasi-pseudo-monotone type III operators has been obtained on compact domains in locally convex Hausdorff topological vector spaces. These more general forms of variational inequalities for the above types of operators used the more general form of minimax inequality by Chowdhury and Tan in [3] as the main tool to derive them. Our new results established in this paper should have potential applications in nonlinear analysis and related applications, e.g., see Aubin [1], Yuan [11] and references wherein.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.2
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• pp.133-137
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• 2000

In this paper we introduce vector variational-type inequalities for fuzzy mappings on Hausdorff topological vector spaces and obtain an existence theorem of solutions to the inequalities.

• Nonlinear Functional Analysis and Applications
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• v.23 no.4
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• pp.779-795
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• 2018

In this paper, we establish the sufficient conditions for the existence of solutions for multi-valued equilibrium problems.

• Journal of the Korean Mathematical Society
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• v.35 no.4
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• pp.803-829
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• 1998

We give general fixed point theorems for compact multimaps in the "better" admissible class $B^{K}$ defined on admissible convex subsets (in the sense of Klee) of a topological vector space not necessarily locally convex. Those theorems are used to obtain results for $\Phi$-condensing maps. Our new theorems subsume more than seventy known or possible particular forms, and generalize them in terms of the involving spaces and the multimaps as well. Further topics closely related to our new theorems are discussed and some related problems are given in the last section.n.