• 한국자동차공학회논문집
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• 제18권4호
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• pp.92-98
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• 2010

Virtual ground modeling is one of key topic for real-time vehicle dynamic simulation. This paper discusses about the virtual 3D road modeling process using parametric surface concept. General road data is a type of lumped position vector so interpolation process is required to compute contact of internal surface. The parametric surface has continuity and linearity within boundaries and functions are very simple to find out contact point. In this paper, the parametric surface formula is adopted to road modeling to calculate road hight. Position indexing method is proposed to reduce memory size and resource possession, and a simple mathematical method for contact patch searching is also proposed. The developed road process program is tested in dynamic driving simulation on off-road. Conclusively, the new virtual road program shows high performance of road hight computation in vast field of off-road simulation.

• 한국CDE학회논문집
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• 제14권5호
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• pp.306-313
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• 2009

This paper presents the unique formation process of a volumetric space with the digital algorithm developed for Voronoi diagram in order to generate an effective parametric architectural form. By applying systematic parameters of architectural conditions within digital parametric tools, the interactions among sub-spaces developed by Voronoi diagram are enhanced by manipulating the spatial structures. In this paper, we discuss how the parametric distributing and zoning geometrical system can support designers in developing a free-formed space, and research on how this system creates a 3D volumetric space. With the in-depth research on the system and structure of Voronoi diagram, the approaches to the application of Voronoi diagram into architectural form generation are clarified to be an effective, creative and successful digital tool. The result of the application of the Voronoi diagram improves the design quality with systematic language in the sense that the sub-regions are created and controlled under the systematic and balanced hierarchy having dynamic relationships among each others with the restoration of the equilibrium of forces and tensions. This 3-dimensional Voronoi diagram provides another means for designers to solve architectural issues and to reinforce their design concepts.

• 산업공학
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• 제24권1호
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• pp.24-39
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• 2011

In this paper, we study the methodology for the measurement and integration of market risk and credit risk using Copula. We apply the methodology of Rosenberg, and Schuermann(2006) to the assets of pension system. Firstly we estimate dynamics of risk factors and their effects on investment returns, then use the estimated result to simulate future movement of risk factors and distribution of investment returns. Finally we measure integrated risk using integrated return distribution by Copula and simulated future investment return distributions. We found the integrated risk changing with the correlation of risks and investment weights of risks and confirmed the diversification effect of risks. This result is consistent when we use normal Copula and normal marginals, t-Copula and t(3) marginals, and normal Copula and non-parametric marginals. And in the case of non-parametric maginals, larger integrated risk is calculated. It means that use of non-parametric marginals is more conservative.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.767-776
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• 2014

본 연구는 베트남 호치민시 보건부 데이터베이스에서 추출한 20개 공공종합병원의 2006년부터 2010년까지 5년간 패널자료를 이용하여 비모수적 기법과 모수적 기법을 활용하여 규모수익과 생산성 변화를 측정하였다. 그 결과를 요약하면 다음과 같다. 첫째, 비모수 기법으로 측정된 생산성 증가율은 5년간 누적 증가율이 2.8%이며 이는 5.8%의 기술효율성 증가와 기술효율성 개선에 기인하고 있다. 반면 규모효율성은 5.2% 감소하고 있다. 둘째, 모수적 기법으로 측정한 생산성은 17.1% 감소를 보였으며 이는 17.1%의 기술 퇴보와 9.1%의 규모효율성 감소에 기인하고 있다. 두 기법에서의 공통적인 점은 베트남 공공종합병원에서 규모의 비효율성이 발생하고 있으며 규모의 비효율성 변화가 생산성 변화에 중요한 영향을 미치고 있었다. 즉 베트남 공공종합병원은 분석표본의 70%~80%가 규모의 체증상태에 있으며 이는 환자 수에 비해 공공병원의 규모가 과잉공급 상태에 있음을 시사하고 있다. 이 연구는 베트남 공공병원의 효율성과 생산성 변화를 측정한 국내 첫 연구이며 향후 베트남 병원산업 진출을 위한 기초 정보로 활용될 수 있다는 점에서 의미가 있다.

• 안보군사학연구
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• 통권1호
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• pp.191-229
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• 2003

Multi-sensor data fusion techniques combine evidences from multiple sensors in order to get more accurate and efficient meaningful information through several process levels that may not be possible from a single sensor alone. One of the most important parts in the data fusion system is the identification fusion, and it can be categorized into physical models, parametric classification and cognitive-based models, and parametric classification technique is usually used in multi-sensor data fusion system by its characteristic. In this paper, we propose a novel heuristic identification fusion method in which we adopt desirable properties from not only parametric classification technique but also cognitive-based models in order to meet the realtime processing requirements.

• 한국BIM학회 논문집
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• 제3권3호
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• pp.19-28
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• 2013

In Korea highway bridges, most piers are the type of one-column or multi-column ones. So, in this study, under an environment applying BIM so fast, to activate researches on two-column piers subjected to bidirectional seismic loading, a 3D parametric modeling method was selected when the model of two-column piers and one-column piers were formed. Also, interface module between input data in structural analysis and 3D model of RC pier was developed. The module can create the input data for non-linear structural analysis like material, geometric properties and additional coefficients.

• 한국지구과학회지
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• 제26권2호
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• pp.114-128
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• 2005

Fuzzy information representation of multi-source spatial data is applied to landslide hazard mapping. Information representation based on frequency ratio and non-parametric density estimation is used to construct fuzzy membership functions. Of particular interest is the representation of continuous data for preventing loss of information. The non-parametric density estimation method applied here is a Parzen window estimation that can directly use continuous data without any categorization procedure. The effect of the new continuous data representation method on the final integrated result is evaluated by a validation procedure. To illustrate the proposed scheme, a case study from Jangheung, Korea for landslide hazard mapping is presented. Analysis of the results indicates that the proposed methodology considerably improves prediction capabilities, as compared with the case in traditional continuous data representation.

• 한국멀티미디어학회논문지
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• 제19권11호
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• pp.1900-1908
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• 2016

Recent times have seen the introduction of modeling technologies using implicit surface and marching cubes algorithm in the field of computer graphics. Implicit surface modeling is used to express characters or fluid. This study presents a calculation method for the density of curve skeletal primitives using parametric curve and implements an implicit surface modeling tool by utilizing Maya API. Skeletal primitives can be assembled and utilized in character modeling using the implemented modeling tool. Results could be obtained more effectively compared to existing particle-based methods.

• KSTLE International Journal
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• 제2권1호
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• pp.35-39
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• 2001

In this paper, statistical approach is undertaken to investigate the classification of wear debris which is the key function of objective assessment of wear debris morphology. Wear tests are run to produce various kinds of wear debris. The images of wear debris from wear tests are captured with image acquisition equipment. By thresholding, two-dimensional binary images of wear debris are made and, then, morphological parameters are used to quantify the images of debris. Parametric and nonparametric discriminant method are employed to classify wear debris into predefined wear conditions. It is demonstrated that classification accuracy of parametric and nonparametric discriminant method is similar. The selected use of morphological parameters by stepwise discriminant analysis can generally improve the classification accuracy of parametric and nonparametric discriminant method.

• 한국항공운항학회지
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• 제16권4호
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• pp.1-11
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• 2008

This research presents a study for the knowledge-based configuration design development of a RC (remote control) helicopter. Parametric design and knowledge based design concepts are introduced for rapid design changes and analyses using commercial CAD software, CATIA(R) Knowledgeware module. It is crucial for RC helicopter design because it enables rapid conceptual design through instant configuration changes. Positions and dimensions of RC helicopter parts were used as design parameters. As an example, positions of CG(center of gravity) points were traced and plotted as the configuration changes. Further research should be performed in areas of user interfaces and web-based multi-user environments instead of using Excel data sheets.