• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.235-246
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• 2005

We present an interpolating, univariate subdivision scheme which preserves the discrete curvature and tangent direction at each step of subdivision. Since the polygon have a geometric information of some original(in some sense) curve as a discrete curvature, we can expect that the limit curve has the same curvature at each vertex as the control polygon. We estimate the curvature bound of odd vertices and give an error estimate for restoring a curve from sampled vertices on curves.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권4호
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• pp.253-287
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• 2018

This paper studies the global stability of a class of discrete-time pathogen infection models with latently infected cells. The rate of pathogens infect the susceptible cells is taken as bilinear, saturation and general. The continuous-time models are discretized by using nonstandard finite difference scheme. The basic and global properties of the models are established. The global stability analysis of the equilibria is performed using Lyapunov method. The theoretical results are illustrated by numerical simulations.

• Kyungpook Mathematical Journal
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• 제47권4호
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• pp.529-548
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• 2007

The purpose of this article is to find a relation between the finite difference method and the boundary element method, and propose a new approach deriving a discrete approximation formula as like that of the finite difference method for harmonic functions. We develop a discrete approximation formula on a uniform grid based on the boundary integral formulations. We consider three different boundary integral formulations and derive one discrete approximation formula on the uniform grid for the harmonic function. We show that the proposed discrete approximation formula has the same computational molecules with that of the finite difference formula for the Laplace operator ${\nabla}^2$.

• 한국컴퓨터정보학회논문지
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• 제16권2호
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• pp.235-242
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• 2011

정보 통신분야의 발전과 성장, 신기술의 보급으로 인하여 컴퓨터 산업은 빠르게 변화하고 있다. 이런 변화의 초석이 되는 소프트웨어 분야의 중요성은 점차 강조되고 있다. 소프트웨어 분야 연구의 기본 이론인 수학과 통계학의 중요성의 인식도 증대하고 있고, 수학의 분야 중에서도 이산수학에 대한 이해는 상당히 중요해 지고 있다. 컴퓨터 공학의 소프트웨어 분야에서의 기존 지식을 이해하고 미래에 다양한 분야에 응용하여 신기술을 개발하고, 연구를 하기 위한 기본적인 이산수학분야의 이해가 필수적이다. 이산수학에서 배워야 하는 분야와 내용에 대한 표준안도 아직 정립되지 않았고, 관련되는 내용이 방대 하여 교육이 적절치 않게 이루어지고 있다. 본 연구에서는 컴퓨터 소프트웨어 분야의 트랙별 연구에 관련성이 높은 이산수학 분야를 세분 설정하고, 연관성이 많은 부분을 선택 하여, 분야별 특성에 맞는 연구가 보다 효율적으로 이루어지고, 급변하는 관련 분야의 응용에 대처 할 수 있는 수학 교육방법론을 제시 하였다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제2권2호
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• pp.31-40
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• 1998

Spectral analysis by energy method is given for a fully discrete methods for hyperbolic integro-differential equations with a weakly singular kernel. Stability and error estimates in $H^1$-norm are derived.

• 대한수학회지
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• 제36권6호
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• pp.1033-1046
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• 1999

This paper is devoted to the point wise error estimate up to boundary for the standard finite element solution of Poisson equation with Dirichlet boundary condition. Our new approach used the discrete maximum principle for the discrete harmonic solution. once the mesh in our domain satisfies the $\beta$-condition defined by us, the discrete harmonic solution with dirichlet boundary condition has the discrete maximum principle and the pointwise error should be bounded by L-errors newly obtained.

• 충청수학회지
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• 제20권3호
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• pp.321-325
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• 2007

We prove the Medina's results about the existence and uniqueness of solutions of discrete Volterra equations of convolution type in weighted spaces, by using the well-known Contraction Mapping Principle.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권2호
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• pp.127-133
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• 2018

We look at Toeplitz arrays on ${\mathbb{Z}}^d$ and study a characterizing property for pure discrete spectrum in terms of the periodic structures of the Toeplitz arrays.

• Journal of applied mathematics & informatics
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• 제25권1_2호
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• pp.363-374
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• 2007

In this paper, we consider the discrete nonlinear delay model which describe the control of a single population of cells. We establish a sufficient condition for oscillation of all positive solutions about the positive equilibrium point and give a sufficient condition for the global attractivity of the equilibrium point. The oscillation condition guarantees the prevalence of the population about the positive steady sate and the global attractivity condition guarantees the nonexistence of dynamical diseases on the population.

• Journal of applied mathematics & informatics
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• 제4권2호
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• pp.387-396
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• 1997

For given discrete derivative data in a rectangular re-gion we propose a method to generate an approximated surface which fits the given derivative data in the region and extends smoothly to a sufficiently large rectangular region. Such an extension in nec-essary in the generation of the surface in NC(numerical control) ma-chine.