• Journal of the Chungcheong Mathematical Society
• /
• v.29 no.1
• /
• pp.83-93
• /
• 2016

In this paper, we introduce a generalized quadratic functional equation with several variables and then investigate its generalized Hyers-Ulam stability in normed spaces.

• Bulletin of the Korean Mathematical Society
• /
• v.42 no.2
• /
• pp.257-267
• /
• 2005

The aim of this paper is to give three equilibrium existence theorems for generalized games with lower semi continuous constraint and preference multimaps by using Michael's continuous selection theorem.

• East Asian mathematical journal
• /
• v.32 no.5
• /
• pp.621-633
• /
• 2016

We establish the existence of positive solutions to nonlocal boundary value problems with integral boundary condition and non-negative real boundary parameter by mainly using the Schauder-Fixed point theorem.

• Journal of the Korean Mathematical Society
• /
• v.42 no.4
• /
• pp.749-759
• /
• 2005

We apply a cone theoretic fixed point theorem and obtain conditions for the existence of positive periodic solutions of the system of functional differential equations $$x'(t)\;=\;A(t)x(t)+{\lambda}f(t,\;x(t-\tau(t))$$.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.4 no.2
• /
• pp.67-75
• /
• 2000

Sufficient conditions for boundary controllability of time varying delay integrodifferential systems in Banach spaces are established. The results are obtained by using the strongly continuous semigroup theory and the Banach contraction principle.

• Kyungpook Mathematical Journal
• /
• v.47 no.4
• /
• pp.569-578
• /
• 2007

Sufficient conditions for the existence of at least one solution of boundary value problems for higher order nonlinear difference equations are established. We allow $f$ to be at most linear, superlinear or sublinear in obtained results.

• Journal of the Chungcheong Mathematical Society
• /
• v.33 no.2
• /
• pp.205-217
• /
• 2020

We will introduce a new type of quartic functional equation and then investigate the stability for a quartic functional equation in a convex modular space.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.5 no.2
• /
• pp.149-156
• /
• 2001

Sufficient conditions for boundary controllability of semilinear systems in Banach spaces are established. The results are obtained by using the analytic semigroup theory and the Banach contraction principle. An example is provided to illustrate the theory.

• Journal of the Korean Mathematical Society
• /
• v.35 no.1
• /
• pp.85-114
• /
• 1998

We prove the existence of solutions of the Reimann problem for a system of conservation laws of mixed type using the method of vanishing viscosity term.

• The Pure and Applied Mathematics
• /
• v.28 no.1
• /
• pp.15-26
• /
• 2021

The purpose of this paper is to introduce a new type of a cubic functional equation and then investigate its stability problems in a convex modular space with a generalized ∆a-condition.