• Kyungpook Mathematical Journal
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• 제21권2호
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• pp.163-165
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• 1981

• Kyungpook Mathematical Journal
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• 제20권2호
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• pp.141-143
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• 1980

• 대한수학회논문집
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• 제32권2호
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• pp.457-466
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• 2017

We study the existence and uniqueness of S-asymptotically ${\omega}-periodic$ mild solutions for some partial functional integrodifferential equations with infinite delay and nonlocal conditions.

• 산업경영시스템학회지
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• 제17권32호
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• pp.221-226
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• 1994

Almost preventive maintenance policies assumed that the system after pm has failure rate as before pm with probability p and as good as new with probability 1-p. This paper considers the s-expected cost of the model with imperfect periodic preventive maintenance that increasing minimal repair costs at failure and obtains the optimum periodic preventive maintenance time. Numerical example are shown in which the failure time of the system has gamma distribution.

• Journal of the Korean Statistical Society
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• 제3권1호
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• pp.13-16
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• 1974

In my former paper [3] I defined an almost periodicity of weakly sationary random processes (a.p.w.s.p.) and presented some basic results of it. In this paper I shall present some notes on the Fourier series of an a.p.w.s.p., resulting from [3]. All the conditions at the introduction of [3] are assumed to hold without repreating them here. The essential facts are as follows : The weakly stationary process $X(t,\omega), t\in(-\infty,\infty), \omega\in\Omega$, defined on a probability space $(\Omega,a,P)$, has a spectral representation $$X(t,\omega)=\int_{-\infty}^{infty}{e^{it\lambda\xi}(d\lambda,\omega)},$$ where $\xi(\lambda)$ is a random measure. Then, the continuous covariance $\rho(\mu) = E(X(t+u) X(t))$ has the form $$\rho(u)=\int_{-\infty}^{infty}{e^{iu\lambda}F(d\lambda)},$$ $E$\mid$\xi(\lambda+0)-\xi(\lambda-0)$\mid$^2 = F(\lambda+0) - F(\lambda-0) \lambda\in(-\infty,\infty)$, assumimg that $\rho(u)$ is a uniformly almost periodic function.

• 충청수학회지
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• 제24권4호
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• pp.863-868
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• 2011

The purpose of this paper is to study the orbit behaviours near almost periodic points. We introduce notions of uniformly recurrent and u-recurrent points and investigate some relationships between these properties.

• 대한수학회논문집
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• 제5권2호
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• pp.27-29
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• 1990

• 대한수학회보
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• 제21권2호
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• pp.138-138
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• 1984

• Korean Journal of Mathematics
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• 제30권3호
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• pp.491-502
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• 2022

In this paper we investigate some sufficient conditions to guarantee the existence and uniqueness of Stepanov-like weighted pseudo almost periodic solutions of cellular neural networks on Clifford algebra for non-automomous cellular neural networks with multi-proportional delays. Our analysis is based on the differential inequality techniques and the Banach contraction mapping principle.

• 대한수학회지
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• 제46권5호
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• pp.1071-1085
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• 2009

This paper considers the problem of existence and exponential stability of almost periodic solution for shunting inhibitory cellular neural networks with distributed delays and large impulses. Based on the contraction principle and Gronwall-Bellman's inequality, some sufficient conditions are obtained. The results of this paper are new and they complement previously known results.