• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.153-163
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• 2004

The main objective of this study is to develop a multi-objective fuzzy optimum design program of steel structures and to verify that the multi-objective fuzzy optimum design is more reasonable than the single objective optimum design in real structural design. In the optimization formulation, the objective functions are both total weight and deflection. The design constraints are derived from the ultimate strength of service ability requirement of AISC-LRFD specification. The structural analysis was performed by the finite element method and also considered geometric non-linearity. The different importance of optimum criteria were reflected with two weighting methods ; membership weighting method and objective weighting method. Thus, designers could choose rational optimum solution of structures with application of two weighting methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.13-20
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• 1987

Methods of nonlinear structural design sensitivity analysis are developed in parallel with the nonlinear finite element structural analysis methods and numerically evaluated. Direct decomposition and iterative solution methods for the secant stiffness approach and direct use of tangent stiffness in the design sensitivity analysis phase are derived and presented as the methods of nonlinear structural analysis and design sensitivity analysis are closely related. From the considerations of theoretical and numerical behavior, the tangent stiffness approach is shown to be efficient as the intermediate results of structural analysis can be effectively used in the design sensitivity analysis stage.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.538-541
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• 2007

In this study, the complex AAM permanent anchor was introduced and the design method for the complex AAM permanent anchor was showed by examining the relationship of the forces applied to the anchor, the ground failure, the loads inducing the tensile failure between the anchors, etc. In order to understand the behavioral characteristics of the complex AAM permanent anchor, the field pullout test was carried out, and the results obtained with the design method were compared with those of the field pullout test.

• Computational Structural Engineering
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• v.7 no.3
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• pp.16-23
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• 1994

본 고에서는 형상최적설계에 대한 기초이론이 소개되었다. 재료도함수와 변분법 및 보조변수법에 기초한 형상설계민감도해석 절차는 까다로우며 함수론 등 많은 수학적인 배경을 필요로 한다. 설계민감도가 구해지면 이 정보를 필요로 하는 최적화 알고리즘을 사용하여 형상에 대한 최적해를 구할 수 있으며 그 과정은 재래식 최적설계시와 같다. 구조물 형상최적설게에 있어 형상(영역)변화의 효과는 대부분 경계에서 수직이동의 형태로 나타난다. 따라서 경계면에서 변위나 응력값 등에 대한 정확한 수치해는 성공적인 형상최적화의 중요한 관건이 된다. 따라서 구조해석을 위한 정확한 유한요소해석방법과 형상함수 그리고 경계를 나타내는 적절한 함수들을 지속적으로 개선할 필요가 있다. 반복설계과정 중에서 영역과 경계가 계속 바뀌므로 설계민감도 수치해의 정확도를 높이기 위해 경계요소법과 유한요소법에 기초를 둔 영역법 등을 사용하기도 한다.

• Journal of the Korean Magnetics Society
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• v.27 no.2
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• pp.54-62
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• 2017

This paper presents a design of the Interior Permanent Magnet Synchronous Motor (IPMSM). an initial design process is accomplished by using the parametric design. In the design process, motor characteristics of parameters is computed by the d-q axis equivalent circuit model. Then, an optimal design process is accomplished by combination the experimental design and the response surface method. Finally, the design and analysis results are verified with experimental results.

• Water for future
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• v.27 no.3
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• pp.135-143
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• 1994

This paper presents a model for the optimal design of dendritic water distribution systems using linear progranning technique. The optimization model was formulated and applied to a coastal region reclamation project site located in Hae-Ham, Jun-Nam province. The water distribution systems in the region had aleady been designed using a hydraulic simulator(BRANCH). The optimization model developed in this research utilized the data given in the report of the project. The comparison between the systems designed by the simulator and by the optimization model shows that the optimization model provides better results and can be utilized more efficiently in the design of dendritic water distribution systems.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.1
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• pp.37-48
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• 2022

In this study, a hybrid meta-heuristic approach is proposed for solving engineering design optimization problems. Various approaches in many literatures have been proposed to solve engineering optimization problems with various types of decision variables and complex constraints. Unfortunately, however, their efficiencies for locating optimal solution do not be highly improved. Therefore, we propose a hybrid meta-heuristic approach for improving their weaknesses. the proposed GA-VNS-HC approach is combining genetic algorithm (GA) for global search with variable neighborhood search (VNS) and hill climbing (HC) for local search. In case study, various types of engineering design optimization problems are used for proving the efficiency of the proposed GA-VNS-HC approach

• International Journal of Highway Engineering
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• v.5 no.1 s.15
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• pp.1-10
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• 2003

The objective of pavement design, just as with the design of other structures, is to obtain the most economical designs at specified levels of reliability. Methods that yield designs with different levels of reliability are undesirable, and over the course of time design approaches in the U.S. and Europe have converged toward the Load and Resistance Factor Design (LRFD) format in order to assure uniform reliability. At present the LRFD format has been implemented in concrete, steel, wood and bridge design specifications. In this paper, reliability theories are used to illustrate the development of an LRFD format for Mechanistic-Empirical (M-E) design of flexible pavements as an alternative of its reliability module. It is shown in this paper that ten candidate pavement sections designed with a reliability level using the AASHTO design guide (1986) do not have uniform structural reliability in terms of pavement mechanistic distress such as fatigue cracking and the uniform reliability can be achieved by using the LRFD format.

• Computational Structural Engineering
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• v.4 no.2
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• pp.24-31
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• 1991

국내의 경우 1988년에 건축물에 대한 내진설계기준이 제정되어 대형건축물에 대한 내진설계가 의무화되고 있으나, 도로교에 대해서는 아직 체계적인 연구나 설계방법이 도입되지 않고 있는 실정이다. 그러나 최근 국내에 건설된 올림픽대교, 팔당대교, 강동대교와 과거에 건설된 남해대교, 돌산교 등에서 미국이나 일본의 설계기준을 참조하여 내진해석을 실시한 바 있고, 앞으로 건설될 대형고량에 내진설계가 보편화될 것이 예상되는 바, 지진의 다발지역인 미국 캘리포니아주의 내진설계법과 지진의 피해가 다소 경미한 지역을 대상으로 한 미국의 도로교시방서(AAS HTO제정)의 내진설계법을 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2501-2503
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• 2005

탐침형 정보 저장 장치는 원자 현미경의 원리를 이용한 차세대 고밀도 저장장치로 여겨진다. 정보의 크기가 수십 나노미터 이하이므로 정밀한 위치 제어 알고리즘이 필수적이다. 본 논문에서는 별도의 위치 센서없이 복수개인 탐침을 이용하여 원하는 데이터 위치로 이동하는 servo algorithm, 정보 추종을 위한 tracking algorithm 및 위치 검출용 탐침의 수를 줄이고 최적 제어기 설계를 위한 노이즈 특성 안정화를 위한 servo code 설계법을 제안하고 제어기 설계법을 제안한다.