• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.383-395
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• 2010

In the present paper, we construct the traveling wave solutions involving parameters of nonlinear evolution equations in the mathematical physics via the (3+1)- dimensional potential- YTSF equation, the (3+1)- dimensional generalized shallow water equation, the (3+1)- dimensional Kadomtsev- Petviashvili equation, the (3+1)- dimensional modified KdV-Zakharov- Kuznetsev equation and the (3+1)- dimensional Jimbo-Miwa equation by using a simple method which is called the ($\frac{G'}{G}$)- expansion method, where $G\;=\;G(\xi)$ satisfies a second order linear ordinary differential equation. When the parameters are taken special values, the solitary waves are derived from the travelling waves. The travelling wave solutions are expressed by hyperbolic, trigonometric and rational functions.

• 한국콘텐츠학회논문지
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• 제9권1호
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• pp.304-311
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• 2009

본 연구에서는 시간의 경과에 기반을 둔 누적감가상각비율함수를 이용한 새로운 감가상각방법을 제안한다. 제안된 방법은 임의의 시점에서의 누적감가상각금액을 계산해내는 방법으로, 현재 사용되고 있는 방법들이 가지고 있는 문제점들을 해결할 수 있을 뿐만 아니라, 시간의 경과에 따라 매 회기의 감각상액이 일정하거나, 점차 감소하거나, 점차 증가하는 모든 경우를 체계적으로 계산해낼 수 있다. 이 방법을 사용하면 각 자산의 특성에 맞는 다양한 감각상각형태를 합리적으로 선택하여 사용할 수 있고, 기중에 자산을 취득하거나 처분하는 경우에도 체계적이고 일관성 있게 감가상각비를 상계할 수 있게 된다.

• Structural Engineering and Mechanics
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• 제30권1호
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• pp.119-129
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• 2008

A small strain and elastoplastic formulation of Polygonal Element Method (PEM) is developed for efficient analysis of elastoplastic solids. In this work, the polygonal elements are constructed based on traditional triangular finite meshes. The construction method of polygonal mesh can directly utilize the sophisticated triangularization algorithm and reduce the difficulty in generating polygonal elements. The Wachspress rational finite element basis function is used to construct the approximations of polygonal elements. The incremental variational form and a von Mises type model are used for non-linear elastoplastic analysis. Several small strain elastoplastic numerical examples are presented to verify the advantages and the accuracy of the numerical formulation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.475-479
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• 2010

For a rational evaluation of the spatial distribution of consolidation settlement, it is necessary to adopt probabilistic method. In this study, mean and standard deviation of consolidation settlement of whole analysis region are evaluated by using the spatial distribution of consolidation layer which is estimated from kriging and statistics of soil properties. Using these results and probabilistic method, the area need to be raised the ground level for balancing the final design ground level are determined.

• 호남수학학술지
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• 제33권2호
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• pp.247-259
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• 2011

In this paper, the $(\frac{G'}{G})$-expansion method is used to construct new exact travelling wave solutions of some nonlinear evolution equations. The travelling wave solutions in general form are expressed by the hyperbolic functions, the trigonometric functions and the rational functions, as a result many previously known solitary waves are recovered as special cases. The $(\frac{G'}{G})$-expansion method is direct, concise, and effective, and can be applied to man other nonlinear evolution equations arising in mathematical physics.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.733-740
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• 2006

Inverted V (or chevron) braced steel frames have been seen as being highly prone to soft story response once the compression brace buckles under earthquake loading. To salvage chevron braced frames. the concept of the zipper column was proposed many years ago such that the zipper column can redistribute the inelastic demand over the height of the building. However. rational design method for the zipper column has not been established yet. In this paper, a new dynamic design method for the zipper column was proposed by combining the refined physical braced model and modal pushover analysis. Inelastic dynamic analysis conducted on 6 story building model showed that the proposed method was more superior to the existing static design method and was very effective in improving seismic performance of chevron braced steel frames.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.363-370
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• 2001

A computationally efficient algorithm to analyze a group pile behavior is proposed by consideration of both soil-pile and pile-cap interactions. Using toad transfer method the nonlinear characteristics of the soil-pile interaction for a single pile is modeled by piecewise linear soil springs (p-y, t-z, and q-z curves). Beam-column method, one of the most practical approaches, is used for numerical modeling of the soil-pile system. In addition to the group effect resulting from the soil-pile-soil interaction, for a more realistic analysis it is essential to consider the effect of pile-cap interaction including geometric configuration of the piles in a group and conectivity conditions between piles and the cap. This paper mainly focuses on the pile-cap interaction and the development of a rational numerical procedure of its incorporation with the beam-column method.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1626-1633
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• 2006

In the present paper, in the context of the meshless interpolation of a moving least squares (MLS) type, a novel method which uses primary and secondary nodes in the domain and on the global boundary is introduced, in order to improve the accuracy of solution. The secondary nodes can be placed at any location where one needs to obtain a better resolution. The support domains for the shape functions in the MLS approximation are defined from the primary nodes, and the secondary nodes use the same support domains. The shape functions based on the MLS approximation, in an integration domain, have a single type of a rational function, which reduces the difficulty of numerical integration to evaluate the weak form. The present method is very useful in an adaptive calculation, because the secondary nodes can be easily added and moved without an additional mesh. Several numerical examples are presented to illustrate the effectiveness of the present method.

• KIEE International Transactions on Power Engineering
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• 제5A권2호
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• pp.177-185
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• 2005

This paper proposes an expert system that can enhance the accuracy of real-time bus reconfiguration strategy by adopting the local minimum tree search method and that can minimize the spreading effect of the fault by considering the operating condition when a main transformer fault occurs in an automated substation. The local minimum tree search method is used to expand the best-first search method. This method has the advantage that it can improve the solution performance within the limits of the real-time condition. The inference strategy proposed expert system consists of two stages. The first stage determines the switching candidate set by searching possible switching candidates starting from the main transformer or busbar related to the event. The second stage determines the rational real-time bus reconfiguration strategy based on heuristic rules from the obtained switching candidate set. Also, this paper proposes generalized distribution substation modeling using graph theory, and a substation database based on the study results is designed.

• 한국해양공학회지
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• 제14권1호
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• pp.95-101
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• 2000

In general, free form design depends on B-spline which is used for the generating hull lines in most of shipyards. But, nowadays, the NURBS method is applied to free form modeling method, which is able to more flexible transformation than B-Spline, and then became industrial standard in the various field. Therefore, this method has been considerably applied in new application fields which are required free form modelling. In this paper, the program called 2DSURF with 5 modules and developed for the generation of hull lines is described. It is examined whether the program can be applied to body lines, sheer lines, and half breadth lines.