• Bulletin of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.52-61
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• 2000

이상에서 MDO 기법의 정식화와 관련된 issue들인 해석의 연성과 관련된 SAND 및 NAND 기법과 의사결정의 분산과 관련된 다단계 최적화 기법을 살펴보았다.Part 2에서는 MDO기법의 정식화 방법들을 소개하고, 각 방법들이 Part1에서 언급된 issue들을 어떻게 다루고 있는지 살펴볼 것이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.229-237
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• 2008

In this research, a MDO(multi-disciplinary design optimization) framework, which integrates aerodynamic and structural analysis to design an aircraft wing, is constructed. Whole optimization process is automated by a parametric-modeling approach. A CFD mesh is generated automatically from parametric modeling of CATIA and Gridgen followed by automatic flow analysis using Fluent. Finite element mesh is generated automatically by parametric method of MSC.Patran PCL. Aerodynamic load is transferred to Finite element model by the volume spline method. RSM(Response Surface Method) is applied for optimization, which helps to achieve global optimum. As the design problem to test the current MDO framework, a wing weight minimization with constraints of lift-drag ratio and deflection of the wing is selected. Aspect ratio, taper ratio and sweepback angle are defined as design variables. The optimization result demonstrates the successful construction of the MDO framework.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.210-218
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• 2003

MDO (multidisciplinary design optimization) technology has been proposed and applied to solve large and complex optimization problems where multiple disciplinaries are involved. In this research. an MDO problem is defined for automobile design which has crashworthiness analyses. Crash model which are consisted of airbag, belt integrated seat (BIS), energy absorbing steering system .and safety belt is selected as a practical example for MDO application to vehicle system. Through disciplinary analysis, vehicle system is decomposed into structure subspace and occupant subspace, and coupling variables are identified. Before subspace optimization, values of coupling variables at given design point must be determined with system analysis. The system analysis in MDO is very important in that the coupling between disciplines can be temporary disconnected through the system analysis. As a result of system analysis, subspace optimizations are independently conducted. However, in vehicle crash, system analysis methods such as Newton method and fixed-point iteration can not be applied to one. Therefore, new system analysis algorithm is developed to apply to crashworthiness. It is conducted for system analysis to determine values of coupling variables. MDO algorithm which is applied to vehicle crash is MDOIS (Multidisciplinary Design Optimization Based on Independent Subspaces). Then, structure and occupant subspaces are independently optimized by using MDOIS.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.2
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• pp.109-117
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• 2004

Optimization has been successfully applied to systems with a single discipline. As many disciplines are involved in coupled fashion, MDO (multidisciplinary design optimization) technology has been developed. MDO algorithms are trying to solve the coupled aspects generated from interdisciplinary relationship. In a general MDO algorithms, a large design problem is decomposed into small ones which can be easily solved. Although various methods have been proposed for MDO, the research is still in the early stage. This research proposes a new MDO method which is named as MDOIS (Multidisciplinary Design Optimization Based on Independent Subspaces). Many real engineering problems consist of physically separate components and they can be independently designed. The inter-relationship occurs through coupled physics. MDOIS is developed for such problems. In MDOIS, a large system is decomposed into small subsystems. The coupled aspects are solved via system analysis which solves the coupled physics. The algorithm is mathematically validated by showing that the solution satisfies the Karush-Kuhn-Tucker condition.

• CDE review
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• v.10 no.1
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• pp.39-47
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• 2004

설계분야의 중요성은 신차 개발에 소요되는 부문별 비용들과 그들이 성능 및 생산성에 미치는 영향을 보여주는 그림 1을 통하여 명확히 설명될 수 있다. 이는 설계부문에 소요되는 비용이 다른 부문에 비해 적지만 성능 및 생산성에 미치는 영향은 지대함을 보여주며, 국내 산업체도 그 중요성을 인식하고 연구개발 투자의 비중을 높여가고 있다. 그런데, 국내 산업체의 현황을 살펴보면, 설계는 부품별 혹은 해석 분야별로 나뉘어 여러 설계부서들에서 이루어지며, 결과를 종합하는 단계에서 서로 상충되는 결과가 나타나면 관리자의 판단이나 부서간 협의에 의하여 재 설계하는 과정을 반복한다. (중략)

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.26-37
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• 2007

A virtual engine test based on "Numerical test cell" can extremely reduce the time and cost for the development of a hardware by coupling multidisciplinary analysis. This paper introduces the development activities of full engine simulation programs in U.S.A. and Europe, with the their related techniques(the engineering models, the simulation environment and high performance computing) based on the NPSS(Numerical Propulsion System Simulation). NASA Glenn research conte. leads the development efforts of NPSS by assembling the current codes and improving their Auctions. VIVACE(Value Improvement through a Virtual Aeronautical Collaborative Enterprise), a consortium of universities, research centers and companies in Europe, is developing the PROOSIS(PRopulsion Object Oriented Simulation Software). The capability for the domestic development is also estimated by surveying the current status.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.187-189
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• 2006

오늘날 공학 분야에서 한 분야에서만 이뤄지던 연구가 다분야 통합 연구로 바뀌어 가고 있다. MDO(Multi-Disciplinary Optimization) 프레임워크는 각 분야의 설계 도구들 간의 데이터 공유로 효율적 관리를 위한 기술과 여러 분야가 분산된 환경 하에서 병렬로 작업할 수 있는 컴퓨팅 환경을 말한다. 기존의 MDO 프레임워크는 여러 분야의 설계 도구들을 통합 관리하는 표준 인터페이스가 없고 이것들의 작업 흐름을 자동으로 통합 관리할 환경이 없다는 문제점이 있다. 본 논문에서는 웹 서비스를 사용하여 각 설계도구 간의 표준 인터페이스를 제공하고, 워크플로우를 사용하여 이것들을 자동으로 통합 관리하는 웹 서비스 기반 통합 설계 프레임워크를 구현한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.11-15
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• 2005

Compared with the conventional ground rocket launching, air-launching has many advantages. However, comprehensive and integrated system design approach is required because the physical geometry of air launch vehicle is quite dependent on the installation limitation of the mother plane. The system design has been performed using two different approaches: the sequential optimization and the multidisciplinary feasible(MDF) optimization method. Analysis modules include mission analysis, staging, propulsion analysis, configuration, weight analysis, aerodynamics analysis and trajectory analysis. MDF optimization shows better result than sequential optimization. As a result of system optimization, a supersonic air launching rocket with total mass of 1244.91 kg, total length of 6.18 m, outer diameter of 0.60 m and the payload mass of 7.5 kg has been successfully designed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.26-32
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• 2005

Compared with the conventional ground rocket launching, air-launching has many advantages. However, a comprehensive and integrated system design approach is required because the physical geometry of air launch vehicle is quite dependent on the installation limitation of the mother plane. The system design has been performed using two different approaches: the sequential optimization and the multidisciplinary feasible(MDF) optimization method. Analysis modules include mission analysis, staging, propulsion analysis, configuration, weight analysis, aerodynamics analysis and trajectory analysis. MDF optimization shows better results than the sequential optimization. As a result of system optimization, a supersonic air launching rocket with total mass of 1244.91kg, total length of 6.36m, outer diameter of 0.60m and the payload mass of 7.5kg has been successfully designed.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.187-190
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• 2005

In this study, the reliablility based design optimization is peformed for an aircraft wing. The flexiblility of the wing was assumed by considering the interaction modeled by static aeroelasticity between aerodynamic forces and the structure. For a multidisciplinary design optimization the results of aerodynamic analysis and structural analysis were included in the optimization formulation. The First Order Reliability Method(FORM) was employed to consider the uncertainty of the designed points.