• The Pure and Applied Mathematics
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• v.20 no.3
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• pp.223-232
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• 2013

Alexseev's formula generalizes the variation of constants formula and permits the study of a nonlinear perturbation of a system with certain stability properties. In recent years M. Pinto introduced the notion of $h$-stability. S.K. Choi et al. investigated $h$-stability for the nonlinear differential systems using the notion of $t_{\infty}$-similarity. Applying these two notions, we study bounds for solutions of the perturbed differential systems.

• The Pure and Applied Mathematics
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• v.18 no.4
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• pp.329-336
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• 2011

Some new Lyapunov-type inequalities for a class of nonlinear differential systems, which are natural refinements and generalizations of the well-known Lyapunov inequality for linear second order differential equations, are given. The results of this paper cover some previous results on this topic.

• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.461-470
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• 2019

In this note, we consider the growth of solutions to second order and higher order linear complex differential equations on annuli instead of the complex plane. We establish several theorems that are analogues of the results in the complex plane.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.4
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• pp.355-368
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• 2021

In this paper, we investigate necessary and sufficient conditions for the approximate controllability for semilinear stochastic functional differential equations with delays in Hilbert spaces without the strict range condition on the controller even though the equations contain unbounded principal operators, delay terms and local Lipschitz continuity of the nonlinear term.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.4
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• pp.393-402
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• 2006

We investigate relations between multiplicity of solutions and source terms in a elliptic equation. We have a concerne with a sharp result for multiplicity of a nonlinear Laplacian differential equation.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.2
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• pp.335-345
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• 2014

In this paper, we investigate bounds for solutions of nonlinear perturbed functional differential systems.

• East Asian mathematical journal
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• v.34 no.5
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• pp.651-660
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• 2018

This paper concerned the existence of positive solutions to the second order differential systems with strongly coupled integral boundary value conditions. By using Krasnoselskii fixed point theorem, we prove the existence of positive solutions according to the parameters under the proper nonlinear growth conditions.

• The Pure and Applied Mathematics
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• v.22 no.2
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• pp.145-158
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• 2015

In this paper, we investigate h-stability and boundedness for solutions of the functional perturbed differential systems using the notion of t_∞-similarity.

• Journal of applied mathematics & informatics
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• v.32 no.5_6
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• pp.697-705
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• 2014

In this paper, we investigate bounds for solutions of the nonlinear functional differential systems.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.1
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• pp.191-196
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• 2013

In this paper we derive some identities on Eulerian polynomials of higher order from non-linear ordinary differential equations. We show that the generating functions of Eulerian polynomials are solutions of our non-linear ordinary differential equations.