• Journal of the Chungcheong Mathematical Society
• /
• v.23 no.4
• /
• pp.691-698
• /
• 2010

In this paper, we first introduce a new model of strategic Nash game with insatiability, and next give two social equilibrium existence theorems for general strategic games which are comparable with the previous results due to Arrow and Debreu, Debreu, and Chang in several aspects.

• Korean Journal of Mathematics
• /
• v.3 no.1
• /
• pp.11-16
• /
• 1995

• Honam Mathematical Journal
• /
• v.12 no.1
• /
• pp.49-60
• /
• 1990

• Journal of applied mathematics & informatics
• /
• v.36 no.5_6
• /
• pp.491-504
• /
• 2018

In this article, we consider a fourth order nonlinear difference system. By making use of the critical point theory, we obtain some new existence theorems of at least one periodic solution with minimal period. Our main approach used in this article is the variational technique and the Saddle Point Theorem.

• Bulletin of the Korean Mathematical Society
• /
• v.38 no.1
• /
• pp.71-79
• /
• 2001

The purpose of this paper is to prove new equilibrium existence theorems of social systems with coordination under general conditions on the preference correspondence in locally convex spaces, and we also give an example which the previous existence results on SSC do not work but our theorem can be applied.

• Kyungpook Mathematical Journal
• /
• v.56 no.2
• /
• pp.419-430
• /
• 2016

In this paper, we investigate the existence and uniqueness of positive solutions for three-point boundary value problem of nonlinear fractional q-difference equation. Some existence and uniqueness results are obtained by applying some standard fixed point theorems. As applications, two examples are presented to illustrate the main results.

• Communications of the Korean Mathematical Society
• /
• v.21 no.2
• /
• pp.273-285
• /
• 2006

In this paper, we shall give an affirmative answer to the question raised by Kim and Tan [1] dealing with generalized vector quasi-variational inequalities which generalize many existence results on (VVI) and (GVQVI) in the literature. Using the maximal element theorem, we derive two theorems on the existence of weak solutions of (GVQVI), one theorem on the existence of strong solution of (GVQVI), and one theorem on strong solution in the 1-dimensional case.

• Kyungpook Mathematical Journal
• /
• v.61 no.1
• /
• pp.139-153
• /
• 2021

In this paper, we study the existence of positive solutions for a class of conformable fractional differential equations with integral boundary conditions. By using the properties of Green's function with the fixed point theorem in a cone, we prove the existence of a positive solution. We also provide some examples to illustrate our results.

• Nonlinear Functional Analysis and Applications
• /
• v.26 no.5
• /
• pp.1011-1020
• /
• 2021

In this paper, first order nonlinear Liouville-Caputo fractional differential equations is studied. The existence and uniqueness of a solution are investigated by using Krasnoselskii and Banach fixed point theorems and the method of lower and upper solutions. Finally, an example is given to illustrate our results.

• Bulletin of the Korean Mathematical Society
• /
• v.34 no.2
• /
• pp.273-285
• /
• 1997

The aim of this paper is to present theorems on the exitence of zeros for mappings defined on convex subsets of topological vector spaces with values in a vector space. In addition to natural assumptions of continuity, convexity, and compactness, the mappings are subject to some geometric conditions. In the first theorem, the mapping satisfies a "Darboux-type" property expressed in terms of an auxiliary numerical function. Typically, this functions is, in this case, related to an order structure on the target space. We derive an existence theorem for "obtuse" quasiconvex mappings with values in an ordered vector space. In the second theorem, we prove the existence of a "common zero" for an arbitrary (not necessarily countable) family of mappings satisfying a general "inwardness" condition againg expressed in terms of numerical functions (these numerical functions could be duality pairings (more generally, bilinear forms)). Our inwardness condition encompasses classical inwardness conditions of Leray-Schauder, Altman, or Bergman-Halpern types.