• Korean Journal of Mathematics
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• v.23 no.2
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• pp.269-282
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• 2015

In this paper, we investigate bounds for solutions of perturbed functional differential systems using the notion of $t_{\infty}$-similarity.

• Journal of applied mathematics & informatics
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• v.33 no.5_6
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• pp.687-697
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• 2015

This paper shows that the solutions to the perturbed nonlinear functional differential system

• The Pure and Applied Mathematics
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• v.22 no.2
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• pp.101-112
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• 2015

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 this paper, we investigate bounds for solutions of the functional nonlinear perturbed differential systems using the two notion of h-stability and $t\infty$-similarity.

• Journal of the Korean Mathematical Society
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• v.53 no.5
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• pp.1019-1036
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• 2016

In this paper, we study the existence of solutions and $L^2$-regularity for fractional order retarded neutral functional differential equations in Hilbert spaces. We no longer require the compactness of structural operators to prove the existence of continuous solutions of the non-linear differential system, but instead we investigate the relation between the regularity of solutions of fractional order retarded neutral functional differential systems with unbounded principal operators and that of its corresponding linear system excluded by the nonlinear term. Finally, we give a simple example to which our main result can be applied.

• 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.33 no.3_4
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• pp.447-457
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• 2015

In this paper, we investigate bounds for solutions of the nonlinear perturbed functional differential systems using the notion of t_∞-similarity.

• Journal of the Chungcheong Mathematical Society
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• v.28 no.2
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• pp.217-228
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• 2015

In this paper, we investigate bounds for solutions of the perturbed nonlinear functional differential systems with a $t_{\infty}$-similarity condition using the notion of h-stability.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.3
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• pp.479-487
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• 2014

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

• Journal of the Chungcheong Mathematical Society
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• v.29 no.1
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• pp.1-11
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• 2016

This paper shows that the solutions to nonlinear perturbed functional differential system $$y^{\prime}=f(t,y)+{\int}^t_{t_0}g(s,y(s),Ty(s))ds+h(t,y(t))$$ have the asymptotic property by imposing conditions on the perturbed part ${\int}^t_{t_0}g(s,y(s),Ty(s))ds,h(t,y(t))$ and on the fundamental matrix of the unperturbed system y' = f(t, y).

• Journal of the Chungcheong Mathematical Society
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• v.28 no.4
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• pp.499-511
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• 2015

This paper shows that the solutions to the perturbed dierential system $$y^{\prime}=f(t,y)+{\int}_{t_o}^{t}g(s,y(s))ds+h(t,y(t),Ty(t))$$ have bounded property. To show this property, we impose conditions on the perturbed part ${\int}^{t}_{t_o}g(s,y(s))ds+h(t,y(t),Ty(t))$ and on the fundamental matrix of the unperturbed system y' = f(t, y).