• 물과 미래
• /
• 제17권3호
• /
• pp.211-219
• /
• 1984

A 4-level baroclinic numerical model is designed by using the vorticity equation and Omega equation. Block-Cyclic-Reduction method is applied to the solution of the Helmholtz defferential equation, which is proved to be better than the Relaxation method from the composite viewpoint of accuracy, stability and economy. It was investigated whether the model explains the physical process influenced by voricity and temperature advection. It was also examined if the model atmosphere describes the general circulation. This examination is similar to Phillips(1956). The result of this numerical experiment shows that the model explains qualitatively the Quasi-Geostrophic theory for the development of Baroclinic wave, as throughly described in Holton(1972).

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제24권3호
• /
• pp.147-153
• /
• 2017

In this paper, we propose a numerical method to solve fuzzy differential equations. Numerical experiments show that when the step size is small, the new method has significantly good approximate solutions of fuzzy differential equation. Graphical representation of fuzzy solutions in three-dimension is also provided as a reference of visual convergence of the solution sequence.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 1997년도 정기학술강연회 발표논문 초록집 Annual Meeting of Korean Society of Coastal and Ocean Engineers
• /
• pp.110-115
• /
• 1997

Recently, since one of the most important societal problems facing us today is the growing incidence of the contamination of coastal sea from variety of sources, several distinct numerical improvements have been made and applying the transport models to flow-dominated transport area. Application of Eulerian numerical models to the solution of sharp-front problems often results in oscillations, phase errors, peak depression, and/or numerical dispersion, unless very fine temporal and spatial steps are adopted. (omitted)

• Journal of applied mathematics & informatics
• /
• 제9권2호
• /
• pp.667-677
• /
• 2002

In this paper we obtain the matrix Tau Method representation of a general boundary value problem for Fredholm and Volterra integro-differential equations of order $\nu$. Some theoretical results are given that simplify the application of the Tau Method. The application of the Tau Method to the numerical solution of such problems is shown. Numerical results and details of the algorithm confirm the high accuracy and user-friendly structure of this numerical approach.

• 대한수학회지
• /
• 제33권2호
• /
• pp.235-247
• /
• 1996

Many numerical computations in science and engineering can only be solved approximately since the available infomation is partial. For instance, for problems defined ona space of functions, information about f is typically provided by few function values, $N(f) = [f(x_1), f(x_2), \ldots, f(x_n)]$. Knwing N(f), the solution is approximated by a numerical method. The error between the true and the approximate solutions can be reduced by acquiring more information. However, this increases the cost. Hence there is a trade-off between the error and the cost.

• Journal of applied mathematics & informatics
• /
• 제5권2호
• /
• pp.293-300
• /
• 1998

The numerical method is used to solve the Fredholm integral equation of the second kind with weak singular kernels using the Toeplitz matrices. The solution has a computing time requir-ment of O(N2) where 2N+1 is the number of discretization points used. Also the error estimate is computed. Some numerical Exam-ples are computed using the Mathcad package.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2001년도 봄 학술발표회 논문집
• /
• pp.147-152
• /
• 2001

This study investigated one-dimensional vertical infiltration to an unsaturated residual soil by numerical solutions, FDM. In order to estimate the parameters needed for numerical analysis, tire soil-water characteristic curve(SWCC) of Shinnae-dong soil, one of the most typical residual soils in Korea, were experimentally obtained. Then, the statistical analysis for obtaining the SWCC was performed. The numerical solution to the linearized governing equation for unsaturated groundwater flow provides the infiltration characteristics for the unsaturated residual soil represented by transient pressure profiles and water contents profiles.

• Journal of applied mathematics & informatics
• /
• 제16권1_2호
• /
• pp.383-405
• /
• 2004

We study the incomprssible Navier Stokes equations for the flow inside contraction geometry. The governing equations are expressed in the vorticity-stream function formulations. A rectangular computational domain is arised by elliptic grid generation technique. The numerical solution is based on a technique of automatic numerical generation of acurvilinear coordinate system by transforming the governing equation into computational plane. The transformed equations are approximated using central differences and solved simultaneously by successive over relaxation iteration. The time dependent of the vorticity equation solved by using explicit marching procedure. We will apply the technique on several irregular-shapes.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1997년도 추계 학술대회논문집
• /
• pp.10-15
• /
• 1997

Unsteady natural convection of an enclosed fluid has been one of the fundamental thermo-fluid problems, of which dynamic relevance is found in many engineering applications. Together with the inherent coupling between the boundary layers and the interior core, and strong interaction between flow and temperature fields, the unsteadiness poses serious hurdles for analytical and experimental approaches. With the recent development of computers and solution algorithms, computational fluid dynamics has become the prevailing tool to tackle the underlying problems. In this presentation, a few examples of numerical studies are introduced. The usefulness and potential of numerical simulations in investigating unsteady natural convection are elaborated.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제27권1호
• /
• pp.35-42
• /
• 2020

In this paper, numerical algorithms for solving a fuzzy system of linear equations with crisp coefficients are presented. We illustrate the efficiency and accuracy of the proposed methods by solving some numerical examples. We also provide a graphical representation of the fuzzy solutions in three-dimension as a visual reference of the solution of the fuzzy system.