• 한국전자파학회논문지
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• 제16권5호
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• pp.447-454
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• 2005

Debye 매질에 대한 $(FD)^2TD$ 해석에 있어 JEC(JE Convolution) 기법은 기존의 기법들보다 적은 분산 오차를 가지지만 긴 계산 시간과 추가의 메모리를 필요로 하는 단점을 지닌다. 따라서 본 논문에서는 컨볼루션의 이산적분 구간을 변경해 줌으로써 유도되는 수정된 JEC 기법을 제안하였고 그 결과 기존의 RC(Recursive Convolution)나 JEC 기법보다 적은 분산 오차를 보이는 것을 확인할 수 있었다 또한 수정된 JEC 기법 이 기존 기법들 중 가장 간단한 RC 기법과 같은 계산 복잡도와 메모리량을 요구하면서도 그보다 적은 분산 오차를 보인다는 것을 확인하였다.

• Kyungpook Mathematical Journal
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• 제48권3호
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• pp.379-385
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• 2008

Making use of a linear operator, we introduce certain subclass of meromorphically univalent functions in the punctured unit disk and study its properties including some inclusion results, coefficient and distortion problems. Our result generalize many results known in the literature.

• Kyungpook Mathematical Journal
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• 제47권3호
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• pp.393-401
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• 2007

In the present paper we introduce the subclass $S^{\lambda}_{a,c}(p,A,B)$ of analytic functions and then we investigate some interesting properties of functions belonging to this subclass. Our results generalize many results known in the literature and especially generalize some of the results obtained by Ling and Liu [5].

• Kyungpook Mathematical Journal
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• 제28권2호
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• pp.119-122
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• 1988

In recent years, several authors have dealt with the fraction derivative [1], in special functions [2], convolution integral equation [5], differintegral equation [4], the derivative of H-function [6], and some other applications. The present paper considers the fraction derivatve in the form of differential eqiation.

• Korean Journal of Mathematics
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• 제24권3호
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• pp.545-565
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• 2016

In this paper, we present some general results on the pointwise convergence of the non-convolution type nonlinear singular integral operators in the following form: $$T_{\lambda}(f;x)={\large\int_{\Omega}}K_{\lambda}(t,x,f(t))dt,\;x{\in}{\Psi},\;{\lambda}{\in}{\Lambda}$$, where ${\Psi}$ = and ${\Omega}$ = stand for arbitrary closed, semi-closed or open bounded intervals in ${\mathbb{R}}$ or these set notations denote $\mathbb{R}$, and ${\Lambda}$ is a set of non-negative numbers, to the function $f{\in}L_{p,{\omega}}({\Omega})$, where $L_{p,{\omega}}({\Omega})$ denotes the space of all measurable functions f for which $\|{\frac{f}{\omega}}\|^p$ (1 ${\leq}$ p < ${\infty}$) is integrable on ${\Omega}$, and ${\omega}:{\mathbb{R}}{\rightarrow}\mathbb{R}^+$ is a weight function satisfying some conditions.

• 대한수학회지
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• 제50권5호
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• pp.1105-1127
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• 2013

Let C[0, $t$] denote the function space of real-valued continuous paths on [0, $t$]. Define $X_n\;:\;C[0,t]{\rightarrow}\mathbb{R}^{n+1}$ and $X_{n+1}\;:\;C[0,t]{\rightarrow}\mathbb{R}^{n+2}$ by $X_n(x)=(x(t_0),x(t_1),{\ldots},x(t_n))$ and $X_{n+1}(x)=(x(t_0),x(t_1),{\ldots},x(t_n),x(t_{n+1}))$, respectively, where $0=t_0 <; t_1 <{\ldots} < t_n < t_{n+1}=t$. In the present paper, using simple formulas for the conditional expectations with the conditioning functions $X_n$ and $X_{n+1}$, we evaluate the $L_p(1{\leq}p{\leq}{\infty})$-analytic conditional Fourier-Feynman transforms and the conditional convolution products of the functions, which have the form $fr((v_1,x),{\ldots},(v_r,x)){\int}_{L_2}_{[0,t]}\exp\{i(v,x)\}d{\sigma}(v)$ for $x{\in}C[0,t]$, where $\{v_1,{\ldots},v_r\}$ is an orthonormal subset of $L_2[0,t]$, $f_r{\in}L_p(\mathbb{R}^r)$, and ${\sigma}$ is the complex Borel measure of bounded variation on $L_2[0,t]$. We then investigate the inverse conditional Fourier-Feynman transforms of the function and prove that the analytic conditional Fourier-Feynman transforms of the conditional convolution products for the functions can be expressed by the products of the analytic conditional Fourier-Feynman transform of each function.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1579-1588
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• 2003

In this paper, the finite element equations for the transient linear viscoelastic stress analysis are presented in time domain, whose variational formulation is derived by using the Galerkin's method based on the equations of motion in time integral. Since the inertia terms are not included in the variational formulation, the time integration schemes such as the Newmark's method widely used in the classical dynamic analysis based on the equations of motion in time differential are not required in the development of that formulation, resulting in a computationally simple and stable numerical algorithm. The viscoelastic material is assumed to behave as a standard linear solid in shear and an elastic solid in dilatation. To show the validity of the presented method, two numerical examples are solved nuder plane strain and plane stress conditions and good results are obtained.

• 소음진동
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• 제9권4호
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• pp.778-784
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• 1999

A method for obtaining the motion of an impact system whose primary and secondary system are composed of lumped masses, springs and dampers, and all the contacts are made through spring and damping elements is presented. The frequency response functions derived from the equations of motion and the impulse response functions obtained from the inverse Fourier transform of the derived frequency response functions are used for the calculation of the system responses. The procedure developed for the calculation of displacements and force time-histories was based on the convolution integrals of impulse response functions and forces applied to the systems. Time histories of displacements and contact forces are obtained for the case where a random excitation is applied to a point in the system. Impact statistics such as contact forces and the time between impacts calculated from those time histories is presented.

• 한국해안해양공학회지
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• 제5권4호
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• pp.288-295
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• 1993

해저 변동에 의해 일정 수심 위를 진행하는 삼차원 파낭의 시간에 따른 변화에 대한 식을 제시하였다. 서(1993)의 해를 기초로 하여 유도된 해석해가 해저변위 함수의 convolution 적분형태로 표시된다. 세개의 상이한 해저변위 함수에 대한 해석해는 해면의 초기조건을 만족함을 보였고 유도한 해를 수치적분하여 파낭 분산효과에 의한 파고 감소에 대한 일반적인 특성을 도시하고 분석하였다.

• 대한전자공학회논문지
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• 제26권5호
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• pp.18-22
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• 1989

무한히 긴 도체 스트립 위에 TE파가 입사될때, 스트립에 유기되는 전류 분포를 계산한다. 스트립의 경계조건식을 공간 영역의 함수로 표시하면 convolution 적분을 포함하는 복잡한 식으로 나타난다. 그러나 그들의 주파수 영역으로 변환하면 전류밀도 함수와 Green함수의 곱으로 간단히 표시된다. 전류분포의 계산 결과는 본 연구에서 제시한 반복 끝내기 조건을 만족할 때 가장 좋은 결과를 보이고 있다.