• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2745-2755
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• 1997

Many large-scale enterprises have developed software systems to build management information system for their business. However, it is hard to maintain share ability of data, compatibility of operation methedology, and interoperability among subsystems when the development project progresses since each distributed team prepares a development plan for its subsystem and must have poor communication problem among those teams. We must apply software configuration management to the whole life cycle of the software system in order to solve those Problems. We need a model and a repository in order to execute configuration management on configuration products like document, data, and source code which are generated through the life cycle of software development. In this paper, we suggest a model for configuration change control where cross- referencing among life cycle Phases and data-sharing are highlighted, and define ER model to use IRDS(Information Resource Dictionary system) and IRD schemas.

• Journal of computational fluids engineering
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• v.5 no.3
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• pp.32-39
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• 2000

3차원 Euler 방정식과 adjoint법을 이용한 공력설계코드를 개발하였으며, 이를 초음속수송기의 주날개 설계에 적용하였다. 표면형상의 변화를 위해 Hicks-Henne함수를 사용하였으며, 내부격자점의 수정을 위해 타원형방정식법을 이용하였다. 나셀의 수직이동과 관련되지 않은 설계변수에 대해서는 내부격자점의 이동을 무시함으로써 계산시간을 크게 단축할 수 있었다. 양력과 날개단면두께를 일정하게 유지하면서 항력을 최소화하도록 단면형상을 최적화하였으며, 성공적인 결과를 얻음으로써 본 설계시스템의 타당성 및 효율성을 확인하였다.

• Journal of Power System Engineering
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• v.5 no.1
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• pp.73-79
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• 2001

정전기력을 이용하는 마이크로가속도계 센서는 단결성 실리콘 SOI(Silicon On Insulator) 웨이퍼의 기판에 절전재료 적층과 등방성 및 이방성 부식공정으로 제작한다. 마이크로가속도 센서 개발에는 3차원 미소구조체의 제작공정에서 가열 및 냉각공정의 온도구배로 야기되는 포핑업과 같은 열변형 해석이 최적 형상설계에 중요한 요건이다. 본 연구에서는 양자역학적 현상인 턴널링전류 원리로 승용차 에어백의 검침부 역할을 하는 마이크로가속도 센서의 제조공정에서 소착현상을 방지하는 부가 비임과 턴널갭의 FIB 절단가공과 백금 적층공정의 열적 거동을 해석한다. 마이크로머시닝 공정에서 온도의존성을 고려하여 연성해석하고 유한요소법의 상용코드인 MARC K6.1로 분석한 결과를 단결정 실리콘 웨이퍼로 가공하는 마이크로가속도 센서의 최적공정 및 형상설계를 위한 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.474-477
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• 2009

본 연구에서는 5MW급 수평축 풍력발전 블레이드에 대한 정격풍속과 낮은 풍속 영역을 고려하여 풍속에 대한 다점 최적설계를 수행하였다. 다점 최적설계를 수행하기 위해 블레이드 해석은 Blade Element and Momentum theory를 이용 하였으며, 설계 시 적용된 기저형상은 NREL에서 제안한 5MW급 풍력터빈 블레이드이다. 최적화 과정을 통해 얻어진 최적해의 집합에 대하여 L2 Norm을 통한 파레토분석을 하였으며, 이를 통해 기저형상의 연간 에너지생산량과 설비 이용률을 보다 향상 시킬 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.492-492
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• 2009

Nowadays in Republic of Korea, there is no distinct reference for the related design technology of rotor blade of wind turbine. Therefore the optimum design and evaluation of performance is carried out with foreign commercial code softwares. This paper shows in-house code software that evaluates the aerodynamic design of wind turbine rotor blade using blade element-momentum theory (BEMT) and processes that is applied through various aerodynamics theories such as momentum theory, blade element theory, prandtl's tip loss theory and strip theory. This paper presents the results of the numerical analysis such as distribution of aerodynamic properties and performance curves using in-house code POSEIDON.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.28-36
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• 1999

An efficient inverse design method based on the MGM(Modified Garabedian-McFadden) method has been developed. The 2-D Navier-Stokes equations are solved for obtaining the surface pressure distributions and coupled with the MGM method to perform the inverse design. The MGM method is a residual-correction technique, in which the residuals are the difference between the desired and the computed pressure distribution. The developed code was applied to several airfoil shapes and the propeller. It has been found that they are well converged to their targeting shapes.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.113-122
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• 2010

A two-dimensional thermal response and ablation analysis code for predicting charring material ablation and shape change on solid rocket nozzle is presented. For closing the problem of thermal analysis, Arrhenius' equation and Zvyagin's ablation model are used. The moving boundary problem are solved by remeshing-rezoning method. For simulation of complicated thermal protection systems, this method is integrated with a three-dimensional finite-element thermal and structure analysis code through continuity of temperature and heat flux.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.252-256
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• 1999

In this research, the performance predictions of the submersible mixer were investigated. The variation of the performance characteristics by changing the impeller design parameters were discussed through the flow calculation results by using a commercial program, FLUENT. The performance of the submersible mixers is related to the velocity diffusion profiles downstream of the impeller and also the required input motor power to mix the fluid. In this study, the various design parameters such as the number of blade, the hub and tip diameters, the impeller blade profiles and revolution speed of the blades were taken for the fixed values. The blade sweep direction, the chord length distribution along with the radius of the blade and the inlet blade angle were changed to make different testing models. The flow calculation results show the effect of the changed design parameters on the performance of the submersible mixers and also give some helpful information for designing more efficient submersible mixers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.27-27
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• 2002

본 연구에서는 상용코드 FLUENT를 통한 수치모사 결과를 바탕으로 개발한 이중 원호익형의 성능상관식을 축류펌프의 설계에 적용하여 보았다. 일반적으로 익형의 설계는 크게 두 단계를 거치게 된다. 먼저 반경방향의 평형과 설계조건을 만족하는 임펠러와 디퓨저의 입구와 출구의 속도 삼각형을 얻고, 다음으로 적당한 익형을 선택하여 기하학적 형상을 결정하는 과정으로 이루어져 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.509-515
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• 2013

In this study, the real-coded adaptive range multi-objective genetic algorithm code, which represents the global multi-objective optimization algorithm, was developed for an airfoil shape design. In order to achieve the better aerodynamic characteristics than reference airfoil at landing and cruise conditions, maximum lift coefficient and lift-to-drag ratio were chosen as object functions. Futhermore, the PARSEC method reflecting geometrical properties of airfoil was adopted to generate airfoil shapes. Finally, two airfoils, which show better aerodynamic characteristics than a reference airfoil, were chosen. As a result, maximum lift coefficient and lift-to-drag ratio were increased of 4.89% and 5.38% for first candidate airfoil and 7.13% and 4.33% for second candidate airfoil.