• Proceedings of the KWS Conference
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• 1997.05a
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• pp.185-188
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• 1997

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.4
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• pp.155-159
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• 2004

Numerical analysis which is based on finite element techniques, implicit Euler method and frontal solving algorithm was performed to study the effects of the crucible shape on the temperature of sapphire crystal and the shape of the melt/crystal interface in heat exchanger method. The computer simulation described here and effective to solving the heat transport phenomena with the transition of the interface shape from hemispherical to planar. In the work, various crucibles with differently shaped corners at their bottom are considered to improve the deflection of the melt/crystal interface. The shape of the crucible should be considered as one of the variables for the process optimization.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.467-477
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• 1997

A series of experimental tests have been performed on a tube beam in which artificial damage is applied in order to address damage detectability using modal analysis. Modal parameters considered are frequency, displacement mode shape and strain mode shape CoMAC(Coordinate Modal Assurance Criterion) and Modal Vector Error have been adopted for presenting the change of displacement mode shape and strain mode shape. It is revealed strain mode shape is the most sensitive to damage.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.4
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• pp.23-30
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• 2003

The result of recent seismic hazard analysis indicates that the ground motion response spectra for Korean nuclear power plant site have relatively large frequency acceleration contents. In the ordinary seismic fragility analysis of nuclear power plant structures and equipments, the safety margin of design ground response spectrum is directly used as a response spectrum shape factor. The effects of input response spectrum shape on the floor response spectrum were investigated by performing the direct generation of floor response spectrum from the ground response spectrum. The safety margin included in the design ground response spectrum should be considered as a floor response spectrum shape factor for the seismic fragility analysis of the equipments located in a building.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.150-153
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• 2006

점탄성 복합재는 간단한 작업으로 큰 감쇠 효과를 볼 수 있어 사용이 날로 늘어나고 있다. 그런데 점탄성 복합재의 특성은 온도에 민감하게 반응하며 변화한다. 그러므로 점탄성 복합재의 모드해석 시 온도 변화에 따른 해석이 필요하다. 본 논문에서는 한쪽면에 점탄성재를 부착한 Oberst beam을 일단고정 상태로 설치하여 실험 온도를 $-15{\sim}45^{\circ}C$로 변화시켜가며 전달함수를 이용하여 실험모드해석을 실행하였다. 그리고 온도 차이에 따른 모드형상을 비교하였다.

• Geotechnical Engineering
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• v.14 no.1
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• pp.93-108
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• 1998

In this study, the analytic solutions and numerical methods were used to estimate the shape and size effects on the stability of underground openings. The stability of underground openings was evaluated by scrutinizing the effects of the rock mass quality, the state of in-situ stresses and the lateral earth pressure coefficient on the displacement, the stress concentration and the plastic region developed in the vicinity of the openings. The analytic solutions have shown that the stress concentration factor is inversely proportional to the radius of curvature of openings. Through parametric study on the various shapes and sizes of underground openings the characteristics of the controlling factors concerned with the stability were analyzed. Then, the study was extended to the horseshoe-shaped openings commonly used for under ground storage. Through the extended study the effects of the stress ratio and the height-towidth ratio of openings on the maximum displacement and plastic region developed around the openings were estimated. The results have shorn that the height-to-width ratio of domestic storage caverns can be increased economically without stability problem, as far as the lateral earth pressure coefficient is appropriate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.349-352
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• 2008

This work is to observe combustion characteristics depending on variation of the solid propellent grain configuration. The LRE (Liquid Rocket Engine) enables adjusting the thrust by controling the required fuel mass glow, but the SRM(Solid Rocket Motor)is not easy to adjust th thrust due to the difficulty of th fuel flow control by its combustion behavior even its configuration is simple. This difficulty can be partly solved by changing th size or the configuration of the propellant grain. In this study a proper grain configuration of a small solid rocket is selected through both the theoretical design and the experimental tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.7-12
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• 2008

This paper described results for desiging the best effective bushing geometry by comparing the distribution of the electric field according to bushing geometry. Twelve cases of the geometrical change are tried to analysis. Improvement of the insulation strength related with the vector and the electric field distribution are reached to about 0.7[%] and $21{\sim}26[%]$ by changing the electrode length, respectively. Moreover, in cases of the change of insulator thickness at high-voltage parts, the insulation strength relevant to the same parameters as mentioned above are 2[%] and $23{\sim}43[%]$, respectively Consequently, the quenching voltage for interrupting the partial discharge might be improved due to increasing the insulation strength by the geometrical change.

• Journal of the Korea Computer Graphics Society
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• v.11 no.3
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• pp.1-9
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• 2005

본 논문에서는 피부 변형 방법의 일종으로 스플라인 곡선과 곡면을 이용한 손 형상의 모델링 및 변형 기술을 소개하다. 손 형상의 골격 구조를 근사하는 스윕에 손 형상 메쉬 정점들을 바인딩 하여 관절의 변화에 따라 변형된 손 형상을 얻고, 손 자세 변형에 따라 손바닥 형상이 돌출되고 손금이 생기는 등 기존 연구에서 부족했던 손바닥 형상 변형의 사실성을 얻기 위해 손바닥 형상 변형을 제어하는 넙스 곡면을 생성하고 이용하였다. 손바닥 표면의 정 점들을 보간하여 생성된 넙스 곡면은 사실적인 손바닥 변형을 위해 소수의 보간 점들만 미리 정의된 방법으로 변경하면 되기 때문에 사용하기가 용이하다. 손금은 손바닥 곡면에 대한 차이 값으로 구현되어 손형상 자세에 부합하게 변형되며, 사람에 따라 다른 다양한 손금 형태를 지원할 수 있다. 연구 결과는 사실적인 형상 변형 결과를 보였으며, 실시간 실행이 가능하다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.43-47
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• 1991

For the structural analysis of optimum form decision of 3-D free fort structure such as ship, plane, automobile, definition of versatile forms and comparision between them satisfying the design criterion, is essential. In this paper, three dimensional free-form structure and it's variation are defined and attempts were made to obtain geometric form information for structural analysis. The validity of the method ks been tested for a particular free-form model selected.