• 한국BIM학회 논문집
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• 제7권2호
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• pp.1-7
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• 2017

Urban planning involves many different disciplines. In order for the related stakeholders to have better understanding and acceptable outcomes, planners are required to present a methodology that would properly reflect people's interest. In order to justify the demand and distribute people's interest, planners actively utilized the suitability analysis. Accordingly, a suitability analysis to find the optimal route for high-speed rail was performed in this paper. With ArcGIS and geographic data sets, simple map algebra could be used. The final product of this research was a map indicating the suitable routes for high-speed rail using the shortest path analysis.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1697-1704
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• 2001

A finite element model for polarization switching in electro-mechanically coupled materials is proposed and applied to predict the switching behavior of a two-dimensional ferroelectric ceramic. A complicated micro-structure existing in the material is modeled as il continuum body and a simple 3 node triangle finite element with nodal displacement and voltage degrees of freedom is used for a finite element analysis. The elements use nonlinear constitutive equations, switching criterion and kinetic relation, fur representation of material response at strong electric and stress fields. The polarization state of the material is represented by internal variables in each element, which are updated at each simulation step based on the proposed constitutive equations. The model reproduces strain and electric displacement hysteresis loops observed in the material.

• 한국기계가공학회지
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• 제15권6호
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• pp.136-141
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• 2016

The purpose of this study is to examine the basic design of a submerged cryogenic pump, which is a two stage impeller pump. We limited this study to the impeller design of the submerged pump. We calculated its velocity triangle based on the impeller blade configuration and, in order to check its natural frequency, we carried out a modal test using a finite element method (FEM) analysis. Basically, modal test results had quite similar to FEM analysis.

• 대한기계학회논문집A
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• 제24권10호
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• pp.2469-2476
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• 2000

The meshing of the domain has long been the major bottleneck in performing the finite element analysis. Research efforts which are so-called meshfree methods have recently been directed towards eliminating or at least easing the requirement for meshing of the domain. In this paper, a new meshfree method for solving nonlinear boundary value problem, based on the bubble packing technique and Delaunay triangle is proposed. The method can be efficiently implemented to the problems with singularity by using formly distributed nodes.

• International Journal of CAD/CAM
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• 제3권1_2호
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• pp.111-117
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• 2003

The paper presents an efficient algorithm based on ROAM for visualization of large scale terrain models in real-time. The quality and smoothness of the terrain data visualization within a 3D interactive environment is preserved, while the complexity of the algorithm is kept on a reasonable level. The main contribution of the paper is an introduction of a number of efficient techniques such as implicit coordinates method within the patch array representing ROAM and the viewpoint dependent triangle rendering method for dynamic level of detail (LOD) updates. In addition, the paper presents experimental comparison of a variety of culling techniques, including a newly introduced method: relational position culling. These techniques are incorporated in the visualization software, which allows to achieve more realistic terrain representation and the real-time level of detail reduction.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.270-272
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• 2006

In this paper, we discuss optimal design of Fuzzy Polynomial Neural Networks by means of Genetic Algorithms(GAs) using symbolic coding for non-linear data. One of the major subject of genetic algorithms is representation of chromosomes. The proposed model optimized by the means genetic algorithms which used symbolic code to represent chromosomes. The proposed gFPNN used a triangle and a Gaussian-like membership function in premise part of rules and design the consequent structure by constant and regression polynomial (linear, quadratic and modified quadratic) function between input and output variables. The performance of the proposed model is quantified through experimentation that exploits standard data already used in fuzzy modeling. These results reveal superiority of the proposed networks over the existing fuzzy and neural models.

• Journal of applied mathematics & informatics
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• 제32권3_4호
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• pp.343-357
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• 2014

In many non-life insurance applications past data are given in a form known as the run-off triangle. Smoothing such data using parametric crisp regression models has long served as the basis of estimating future claim amounts and the reserves set aside to protect the insurer from future losses. In this article a fuzzy counterpart of the Hoerl curve, a well-known claim reserving regression model, is proposed to analyze the past claim data and to determine the reserves. The fuzzy Hoerl curve is more flexible and general than the one considered in the previous fuzzy literature in that it includes a categorical variable with multiple explanatory variables, which requires the development of the fuzzy analysis of covariance, or fuzzy ANCOVA. Using an actual insurance run-off claim data we show that the suggested fuzzy Hoerl curve based on the fuzzy ANCOVA gives reasonable claim reserves without stringent assumptions needed for the traditional regression approach in claim reserving.

• 한국생산제조학회지
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• 제8권6호
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• pp.35-42
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• 1999

This paper concentrates on the position control of a pneumatic cylinder under parameter variation. A closed-loop control is proposed to design the different controllers(P, PI, PID, PD controller) in order to choose the best con-troller based on the fast and accurate control of the system. It is shown that the control algorithm, is robust and effective in attaining the fast and accurate position control of system under time-dependent parameter variation. Experimental results showed that PD controller law is effective to obtain the fast response and to increase that sta-blity of the system The method is a useful control algorithm which always automatically adjusts the position con-trol in accordance with the error using carrier wave of triangle type regardless of changes on the operating condi-tion and physical differences between components.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1881-1890
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• 2006

In this paper, a Petrov-Galerkin natural element method (PG-NEM) based upon the natural neighbor concept is presented for the free vibration and dynamic response analyses of two-dimensional linear elastic structures. A problem domain is discretized with a finite number of nodes and the trial basis functions are defined with the help of the Voronoi diagram. Meanwhile, the test basis functions are supported by Delaunay triangles for the accurate and easy numerical integration with the conventional Gauss quadrature rule. The numerical accuracy and stability of the proposed method are verified through illustrative numerical tests.

• 대한수학교육학회지:학교수학
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• 제13권1호
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• pp.19-36
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• 2011

본 연구는 중학교 학생들에게 닮은 삼각형의 대응변 사이에 성립하는 비례적 성질에 기초하여 함수를 작도할 수 있는 기회를 제공함으로써 대수적 함수와 그것의 기하학적 성질에 관한 학생들의 직관을 촉진시키기 위한 것이다. 또한, 학생들이 선택한 작도 방법에 관한 정당화의 과정을 강조함으로써 연역적 추론능력을 향상시키고자 하였다. 이 예비 연구의 결과로서 학생들이 함수를 작도하는 과정에서 나타나는 사고 과정의 특징과 교사의 역할에 관해 기술하였다.