• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.403-407
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• 2012

본 연구의 목적은 최적화 해석 기법을 이용하여 복합재 압력용기의 스커트 치수를 도출하는 것이다. 복합재 압력용기의 스커트 최적화 해석은 부분문제 근사법(sub-problem approximation method) 알고리즘을 사용하였으며, APDL(ANSYS Parametric Design Language)을 이용하여 해석의 모든 과정을 일괄처리(batch processing)하였다. 설계변수로는 압력용기 스커트 부위의 두께와 길이를 선정하였으며, 내압에 의해 발생하는 변위와 무게를 각각 목적함수로 하여 최적화 해석을 통해 최적의 스커트 치수를 도출하였다. 그 결과 복합재 압력용기의 스커트 무게를 최대 4.38% 절감할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.312-314
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• 1997

In this paper, Computer Aided Optimum Design Technique for Three-Phase Induction Motors is proposed. In the technique, reference magnetic flux, specific electric loading factor, specific magnetic loading factor(magnetic flux density) and current density are adopted as design parameters, and minimum total cost including material cost and loss power cost is adopted as a objective function which has to satisfy output condition too. As a result of application to the existing motor, it is proved that this technique is very effective in view of gradually increasing energy costs.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.195-201
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• 2013

In this paper, we present optimization technique for the response time of DVR (Dynamic Voltage Restorer) and the possible compensation range of voltage dip by the DVR system. To protect 3-phase phase-controlled rectifier from voltage dip, DVR system needs to have optimum response time as an important design factor. Although the fast response time of DVR ensures wider range of voltage dip, DVR controller has so high cost and poor stability. This paper proposes DVR system with optimum response time required for certain intensity of voltage dips and good stability to support possible compensation range of voltage dip. Proposed technique showed optimum response time and good stability for overall system. We believe that proposed technique is reliable and useful in DVR design.

• 한국공간구조학회논문집
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• 제1권1호
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• pp.143-155
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• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.315-324
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• 2003

If an optimum design technique is applied in the design of packaging container for bulk-type products, merits on the side of not only economic and compression performance but distribution efficiency are expected. Accordingly, minimum board area (mRBA), compression strength (CS) and compression strength per unit area (mCSPA) are important design parameters in optimum design of packaging container for bulk-type products. In this study, mathematical models for mRBA, CS and mCSPA of container as algorithm for optimum design program were developed. In order to develop these models, compression test by various dimensions of container and response surface analysis for mRBA, CS, and mCSPA of container were carried out. In the developed models, volume, W/L ratio and depth of container were principal independent variables. On the found of these models, optimum design program having faculties of outward and inward optimum design and information design was developed. Though the packaging specifications are same, required board area, board combination and cost of the corrugated board required container manufacture were greatly different by boundary conditions in outward design. Moreover, about 6.3∼10.1% in weight of container was lighter, and about 13.2∼25.6% in cost of container was reduced when the program was applied for 2 kinds of bulk-type products.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.199-204
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• 2000

In this study, an optimum design algorithm using efficient reanalysis is proposed for seismic design of RC Piers. The proposed algorithm for optimization of RC Piers is based on efficient reanalysis technique. Considering structural behavior of RC Piers, several other approximation techniques, such as artificial constraint deletion is introduced to increase the efficiency of optimization. The efficiency and robustness of the proposed algorithm increase the proposed reanalysis technique is demonstrated by comparing it with a conventional optimization algorithm. A few of design examples are optimized to show the applicability of the proposed algorithm.

• 한국지반공학회지:지반
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• 제13권4호
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• pp.95-108
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• 1997

피에조 콘의 소산시험을 이용한 정규 압밀 지반의 압밀계수 추정은 그간 많은 연구자들에 의하여 연구되어 왔으나 각 연구자들의 가정 사항과 해석 방법에 따라 특정한 압밀도에 대해서도 매우 넓은 범위의 이론적인 해들이 제시되어 왔다. 본 연구에서는 보다 현실적이면서 전 범위의 압밀도에 걸쳐서 일관성 있는 압밀계수를 구할 수 있도록 최적화 기법을 적용하였다. 콘 관입효과를 고려하기 위해 연속적인 구형 공동확장을 적용하므로써 이론적으로 얻어지는 간극수압의 분포와 관입 간극수압으로부터 초기 과잉간극수압의 분포를 결정하였으며 축대칭 선형비혼합 압밀이론을 사용하여 유발된 과잉간극수압의 소산효과를 모사하였다. 이와 같이 계산된 소산곡 선과 실제 계측된 소산곡선의 차이를 최소화시키기 위하여 비구속 최적화 알고리듬인 BFGS가 사용되었고 golden section 일차원 탐색법이 사용되었다. 검증 예제를 통하여 적용된 최적화 기법의 안정된 수렴성을 확인하였고 실제 예제에 적용함으로써 제안된 방법이 넓은 범위의 압밀도 범위에서 계측된 소산곡선과 잘 일치하는 압밀계수를 산정함으로써 매우 효과적임을 확인 할 수 있었다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권4호
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• pp.217-222
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• 2010

Since 1980's, optimum design techniques for ship structural design have been developed to the preliminary design which aims at minimum weight or minimum cost design of mid-ship section based on analytic structural analysis. But the optimum structural design researches about the application for the detail design of local structure based on FEA have been still insufficient. This paper presents optimization technique for the detail design of a racing motor boat. To improve the performance and reduce the damage of a real existing racing boat, direct structural analyses; static and non-linear transient dynamic analyses, were carried out to check the constraints of minimum weight design. As a result, it is shown that the optimum structural design of a racing boat has to be focused on reducing impulse response from pitching motion than static response because the dynamic effect is more dominant. Optimum design algorithm based on nonlinear finite element analysis for a racing motor boat was developed and coded to ANSYS, and its applicability for actual structural design was verifed.

• 한국전산구조공학회논문집
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• 제14권4호
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• pp.505-513
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• 2001

본 연구에서는 지진하중을 받는 철근콘크리트(Reinforced Concrete : RC) 교각의 효율적인 최적설계 알고리즘을 제안하였다. 제안한 RC 교각 최적설계 알고리즘은 효율적인 강도재해석 기법을 기초로 하고 있다. 또한 RC 교각의 특성을 고려하여 제약조건 소거기법과 같은 근사화 기법을 도입 하였다. 기존의 최적설계 방법 비교를 통해 제안한 RC 교각의 최적설계 방법의 효율성과 신뢰성을 비교하였다. 그리고 시방서의 내진 규정에 따른 수치예제를 통하여 제안한 강도재해석기법에 의한 새로운 알고리즘이 기존의 최적설계 방법에 비해 효율성과 신뢰도가 우수하다는 것을 입증하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 가을 학술발표회 논문집
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• pp.51-58
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• 1989

Through a series of analyses of specific structures it is shown that incremental collapse may be the critical design criterion and that shakedown analysis can be used as a design tool. Using shakedown analysis technique, a nonlinear structural optimization program has been developed. This incorporates : (ⅰ) design constraints on elastic stresses and deflections ; (ⅱ) constraints for the prevention of incremental collapse and soft story failure ; and (ⅲ) the constraint on the fundamental period of structure. A five-step design procedure is proposed by using this program to obtain the optimum design that satisfies all the requirements of comprehensive earthquake-resistant design.