• Computational Structural Engineering
• /
• v.7 no.1
• /
• pp.15-24
• /
• 1994

전산구조해석분야의 기술이 오늘날과 같이 발전하기 전에는 고층건물의 해석을 위하여 여러가지의 근사해석법이 개발되었고 또 사용되었다. 그러나 최근에는 누구나 우수한 성능의 전산기를 사용할 수가 있는 여건이 갖추어지고 있으며 사용할 수 있는 구조해석용 소프트웨어도 여러가지가 있다. 따라서 앞으로는 근사해석법에 대한 관심이 급격히 줄어들 것이며 대부분의 구조기술자는 전산소프트웨어에 의존하게 될 것이다.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.31 no.6
• /
• pp.331-337
• /
• 2018

This paper presents dynamic algorithm of the MLS(moving least squares) difference method using first order differential Approximation. The governing equations are only discretized by the first order MLS derivative approximation. The system equation consists of an assembly of the approximate function, so the shape of system equation is similar to FEM(finite element method). The CDM(central difference method) is used for time integration of dynamic equilibrium equation. The natural frequency analyses of the MLS difference method and FEM are performed, and two analysis results are compared. Also, the accuracy of the proposed numerical method is verified by displaying the dynamic analysis results together with the results by the existing second order differential approximation. In the process of assembling the first order MLS derivative approximation, the oscillation error was suppressed and the stress distribution was interpreted as relatively uniform.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.3
• /
• pp.1021-1029
• /
• 1991

본 연구에서는 2차원 정사각형 밀폐공간내에서 흡수 및 방사하는 회기체에 대 한 자연대류-복사 열전달을 P-1 및 P-3 근사법을 이용하고 수치해석을 통하여 유동 및 열전달 특성을 연구하였고 Plank 수, 광학두께 및 벽방사율의 영향을 조사하였다. 또한 P-3 근사해와 비교함으로써 P-1 근사해의 적용범위를 고찰하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.179-182
• /
• 2010

본 연구에서는 MLS 차분법을 이용하여 동역학 문제를 해석하기 위한 explicit 동적해석 알고리즘을 제시한다. 격자망이 없는 장점을 부각시키기 위해 이동최소제곱법에 근거한 Taylor 전개로부터 미분근사를 얻고 차분식을 구성했다. 지배 미분방정식의 시간항을 CDM(Central difference Method) 차분하여 빠른 속도로 동적해석을 수행하였다. 수치결과를 통해 본 연구에서 제시한 알고리즘의 정확성과 안정성을 확인할 수 있었다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1991.07a
• /
• pp.18-24
• /
• 1991

항내 정온도 해석은 일반적으로 유한차분법, 유한요소법 및 경계적분 방정식법 등의 엄밀해법과 근사 경계적분법, 고산의 방법 및 파향선법 등의 근사해법으로 구분된다. 엄밀해법은 지배방정식을 이산화 이외의 근사를 사용하지 않고 푸는 수치계산 방법으로 임의형상에의 적용성과 엄밀성이 뛰어나나 대상으로 하는 파의 파장이 짧고 항의 규모가 큰 경우에는 계산용량이 증대되여 실용적이지 못하다.(중략)

• The Journal of Engineering Geology
• /
• v.11 no.2
• /
• pp.153-161
• /
• 2001

The quantitative evaluation of the stereo graphic projection, the limit equilibrium analysis, the finite difference analysis, the distinct element methocI is a analytical evaluation using many variables. Through the reliability analysis by the point estimation technique, uncertainty of other variables that have an effect on the stability of the rock slo~ was considered. The organized evaluation method of the approximate reasoning concept and using a fuzzy language was developed to confer and analysis the failure factors in planning and constructing the rock slope. Considering the result of the an- alysis, it was demonstrated that stability of entire sections can be evaluated through reliability analysis of point estimation technique. The results of stability evaluation by Fuzzy Approximate Reasoning is generally identical with the results of other existirw; analyses. As mentioned above, general and organized evaluation of special qualities of rock slope is possible using RMR Classification, Stereo Graphic Projection, Limit Equilibriwn Analysis, Finite Difference Analysis, Distinct Element Method, Point Estimation Technique, and Fuzzy Approximate Reasoning.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.9
• /
• pp.1056-1064
• /
• 2010

This paper presents the approximate analysis method for the symmetric transmission line crossing the aperture in an backplane. The method of moments is used to determine the aperture impedance for the construction of the equivalent transmission line that the aperture impedance apply to the transmission line as the shunt impedance. As the results, the insertion loss increases at the specific frequency range for the impedance matching. In the case of the mismatching, we are confirmed to the insertion gain at the specific frequency. Also the horizontal length of the aperture affects to the transmission line better than vertical length. The measurement of the insertion loss is performed to verify the theoretical analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.77-79
• /
• 2012

The paper deals with the approximate analysis of printed antenna like superconductor antenna. Analysis of antenna with polarization current in dielectric layer using Moment method. This approximation is very useful for printed antenna on dielectric plane with low dielectric constant. In this paper, we compared numerical results of this method with measurement results.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.3
• /
• pp.373-383
• /
• 2006

In a steel structural system, noncomposite form deck one-way slab is the plate element supported by four-edged steel beams with unequaled stiffness. However, design criterion has analyzed the one-way slab as the continuous beam. Because the end beams that support the one-way slab have elastic supports t hat cause different deflections according to the support conditions and locations, the bending moments corresponding to the support ic support effect is not considered in the design criterion. Accordingly, to conduct a reasonable estimation of approximate moment coefficients considering the unequaled elastic support conditions, this study analyzes and estimates various models with varia bles for the ratios of live load to dead load and pattern arangements of live loads and span lengths. The analytical methods considering the finite three-dimensional plate element, the two-dimensional elastic support and the infinite stifnes suport are performed.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1996.10a
• /
• pp.8-13
• /
• 1996

균질 매질내에 형성되는 근거리 음장의 해석에는 종래 회절 이론에서의 Rayleigh 적분식에 근거한 Lommel 근사식이 주로 이용되어져 왔다. 그러나, 불균질한 매질에서는 그 방법의 적용이 어렵고, 유한요소법등 새로운 방법이 적용되어야 한다. 본 연구에서는 불균질 매질에서의 음장을 해석하는 한 방법으로 Angular Spectrum법을 제안하고, 경계를 가상한 등수온의 물에 대하여 Lommel 근사식에 의해 직접 산출한 음장과 Angular Spectrum법을 적용하여 산출한 음장을 서로 비교함으로써 그 유효성을 검토하였다.