• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.11-14
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• 2012

The category for waterproofing is one of construction process most affected by falling-off in price competitiveness, construction quality, and material performance. Therefore, in order to select of waterproofing construction firms, it is necessary to consider Incorporating both price competitiveness and construction quality. In this article, I would like to analyze 10 Factors for Selecting using fuzzy-AHP model, including the survey of the waterproofing experts. This fuzzy-AHP model can be shown to calculate the fuzzy trigonometrical function to reflect weights for preference of 10 factors for the waterproofing construction firms. It was found from the result that waterproofing construction firms was searched order of priority for select by fuzzy-AHP model.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.122-126
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• 2008

Integrating a 3D solid modeler with a general purpose FEM code, an automatic stress intensity factor analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated and quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. Finally, the complete finite element(FE) model generated, and a stress analysis is performed. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.158-168
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• 1995

연삭숫돌 선택은 공작물제거량, 숫돌의 소모량, 표면정도 및 공작물의 물리적,화학적 특성을 고려하여 설정하는 것을 기본으로 한다. 연삭가공은 구성인자의 상호관계가 복잡하여 이중에서 어느한 요소만을 고려하여 설정하기 어렵고 정량적 기준 또한 정해져있지 않아 현실적으로는 숙련자의 정성적이고 경험적 지식에 따른 주관적 척도에 의존하는 것이 대부분이다. 또한, 연삭숫돌은 작업조건중에서 대량생산을 제외하고는 되도록이면 현장에 구비되어 있는 작업가능한 연삭숫돌 중에서 선택하는 것이 바람직하다. 따라서 본시스템에서는 이와같은 점을 고려하여 최적 연삭숫돌선택을 퍼지이론에 기초한 현장 숙련자의 지식을 활용하므로써 연삭숫돌선택의 효율성을 도모하는 동시에 현장에 연삭숫돌이 구비되지 않은 경우도 고려하여 연삭숫돌설정에 우선순위를 제시하므로써 작업자에 연삭숫돌선택의 유연성을 부여하였다. 또한, 실용성있는 전문가시스템의 구축을 위해 정성적이고 경험적인 지식의 활용을 위한 지식표현으로 설문조사에서 얻은 테이타를 x$^{2}$-분포에 따른 추정신뢰구간을 구해, 이를 토대로한 비대칭 삼각퍼지함수의 결정법을 제시하고, 이를 이용해서 구축한 시스템의 실행결과의 타당성을 비교하고자 한다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.35-44
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• 2009

This paper describes an application of domain decomposition method for parallel finite element analysis which is required to large scale 3D structural analysis. A parallel finite element method system which adopts a domain decomposition method is developed. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay triangulation method is introduced as a basic tool for element generation. Domain decomposition method using automatic mesh generation system holds great benefits for 3D analyses. Aa parallel numerical algorithm for the finite element analyses, domain decomposition method was combined with an iterative solver, i.e. the conjugate gradient(CG) method where a whole analysis domain is fictitiously divided into a number of subdomains without overlapping. Practical performance of the present system are demonstrated through several examples.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.230-235
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• 2009

This paper describes an automatic finite element mesh generation for finite element analysis of three-dimensional structures. It is consisting of fuzzy knowledge processing, bubble meshing and solid geometry modeler. This novel mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of bubbles, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Bubble is generated if its distance from existing bubble points is similar to the bubble spacing function at the point. The bubble spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of finite element for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for 3D geometry.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.105-111
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• 2009

Widely used color information recognition methods based on the RGB color model with static fuzzy inference rules have limitations due to the model itself - the detachment of human vision and applicability of limited environment. In this paper, we propose a method that is based on HSI model with new inference process that resembles human vision recognition process. Also, a user can add, delete, update the inference rules in this system. In our method, we design membership intervals with sine, cosine function in H channel and with functions in trigonometric style in S and I channel. The membership degree is computed via interval merging process. Then, the inference rules are applied to the result in order to infer the color information. Our method is proven to be more intuitive and efficient compared with RGB model in experiment.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.1-10
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• 2009

Wooded areas that are a part of school campuses are one type of urban forest. Most schools located in an urban environment make an excellent setting for a forest in terms of location and area. These kinds of wooded spaces also make the city greener and healthier. As a place where students spend a great deal of time, schools can also be a venue for environmental education. The creation of wooded areas in schools currently has focused on the end result only; by ignoring student needs and participation, these areas have not had a significant influence on student environmental education. Previous studies based on questionnaire survey are significant in that they have quantified subjective qualitative data via Likert Scale. There has been, however, a problem in quantifying the more ambiguous subjective data. Therefore, this paper has attempted to investigate those factors that have an influence on student satisfaction with the wooded areas of their school campus using Fuzzy Theory with elementary school students in Gyeongsangbuk-do. A change was observed in terms of the ranking of arithmetic mean values of 'school peculiarity' and 'emotion evolution' and center of gravity, which has adopted Fuzzy Theory, proving that Fuzzy Theory could rationally objectify qualitative data such as human thoughts. In terms of the influential factors on the satisfaction with school forests(regression coefficient), 'school uniqueness(0.159)' was the highest, followed by 'many trees(0.142),' 'importance of nature(0.136)' and 'emotion evolution(0.130).' This paper may therefore be useful as basic data for objective questionnaire surveys and the development of school forests.