• 대한기계학회논문집B
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• 제27권2호
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• pp.155-162
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• 2003

Design optimization of a transonic compressor rotor (NASA rotor 37) using response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It is also found that the design process provides reliable design of a turbomachinery blade with reasonable computing time.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.135-142
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• 2001

Design optimization of a transonic compressor rotor (NASA rotor 37) using response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. Ana, it is found that the design process provides reliable design of a turbomachinery blade with reasonable computing time.

• 한국전산구조공학회논문집
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• 제26권4호
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• pp.241-246
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• 2013

본 논문에서는 밀도법 기반 위상 최적설계를 통해 얻어진 수치 결과를 바탕으로 CAD 모델을 구성하고 이를 3차원 프린터로 제작하여 실험적으로 최적설계를 검증하였다. 위상 최적설계 과정에서는 체커보드(Checkerboard) 현상이나 잔가지가 종종 나타나는데, 이는 최적설계 구조물을 실제로 제작함에 있어서 어려움을 준다. 이러한 문제점을 해결하기 위하여 민감도 필터링과 모폴로지 기법을 사용하였다. 엄밀한 검증을 위하여 수치 모델과 실험 모델의 부피율을 일치시켰다. 위상 최적설계를 포함한 다양한 설계에 대하여 실험을 통해 비교하여 최적설계 구조물이 가장 높은 강성을 가지고 있음을 확인하였으며 컴플라이언스에 대한 실험결과는 수치해석 값과 잘 일치함을 확인하였다.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.563-573
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• 2007

Optimal design of an automotive catalytic converter for minimization of cold-start emissions is numerically performed using a micro genetic algorithm for two optimization problems: optimal geometry design of the monolith for various operating conditions and optimal axial catalyst distribution. The optimal design process considered in this study consists of three modules: analysis, optimization, and control. The analysis module is used to evaluate the objective functions with a one-dimensional single channel model and the Romberg integration method. It obtains new design variables from the control module, produces the CO cumulative emissions and the integral value of a catalyst distribution function over the monolith volume, and provides objective function values to the control module. The optimal design variables for minimizing the objective functions are determined by the optimization module using a micro genetic algorithm. The control module manages the optimal design process that mainly takes place in both the analysis and optimization modules.

• 응용통계연구
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• 제13권2호
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• pp.393-405
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• 2000

원래 최적실험의 이론은 주어진 모형과 그에 따른 가정에 기초하여 발달되었기 때문에 하나의 최적실험기준이 실험이 가족 있는 여러 목적을 모두 반영하는 것이 무리이다. 따라서 실험자가 다목적 실험기준의 필요성을 느끼는 경우에는 종종 여러 최적실험 기준들의 균형을 이루는 방법을 통해 이러한 문제가 다루어진다. 본 연구에서는 이 분산 구조를 가지고 있는 모형을 예를 들어 복합적인 실험기준들을 알아본다. 왜냐하면 이분산인 경우 D-최적과 G-최적실험간의 동격이론은 더 이상 성립되지 않음에 따라 두 실험기준의 특징은 현격하게 구분되어지기 때문이다. 제약조건최적실험, 결합최적실험, 그리고 minimax 설험방법을 통한 실험기준들간의 균형을 꾀하여 보았다. 처음 두 방법은 실험자의 주관이 반영되어 실제적으로 매우 세심한 주의가 필요한 반면, minimax는 그러한 점을 해소하였다고 본다. 또한 이를 확장하여 오차의 이분산 구조에 대한 불확실성이 존재할 때 적용될수 있는 두 가지 실험기준도 마련하여 보았다. 간단한 알고리즘과 결어를 첨부하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권3호
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• pp.93-100
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• 2003

Switched reluctance motor(SRM) has some advantages such as low cost, high torque density but SRM has essentially high torque ripple due to its salient structure. In order to apply SRM to industrial field, torque ripple has to be reduced. This paper introduces optimal design process of SRM using an optimization algorithm of Progressive Quadratic Response Surface Modeling(PQRSM) and two-dimensional(2D) Finite Element Method(FEM). The electrical and geometrical design parameters have been adopted as 2D design variables. From this work, it can be obtained both the optimal design minimized torque ripple and the optima1 design maximized the average torque, respectively. Finally, this Paper Presents Performance comparison of two optimal designs and consider influence of the selected design variables in torque characteristics.

• 한국생산제조학회지
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• 제24권2호
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• pp.172-176
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• 2015

In this research, a tool was developed to automate one-dimensional finite element analysis (1D FEA) for design of a machine tool spindle. Based on object-oriented programing, this tool employs the objects of a CAD system to construct a geometric model and then to convert it into the FE model of 1D beams at the workbenches of the CAD system with minimum data to define the spindle such as bearing positions and cross-sections of the shaft. Graphic user interfaces were developed for users to interact with the tool. This tool is helpful in identifying a near optimal design of the spindle with the automation of the FEA process with numerous design changes in minimum time and efforts. It is also expected to allow even design engineers to perform the FEA in search of an optimal design of the machine tool spindle.

• 한국산업융합학회 논문집
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• 제14권4호
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• pp.167-172
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• 2011

This paper investigated optimal design for slim wall mount arm for flat TV. Recently the number of flat TV sets in use went on increasing in TV market. As the flat TV sets are getting common, consumers came to need another requirements like aesthetic factor besides display performances. As the new TV sets tend to be slimmer due to aesthetic design, Wall mount also requires to be slimmer for aesthetic balance. Slim structures, however, are vulnerable to structural rigidity. In this study, slim wall mount arm has been designed by 3D CAD and DOE (Design of Experiments) and finite element analysis for optimal structural design were carried out to determine the design variables for minimize working stress of wall mount arm. Finally two optimal design conditions were selected through DOE and FEM and one of those was chosen under constraint of minimizing blanking developed length.

• 대한전기학회논문지
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• 제37권3호
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• pp.180-185
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• 1988

This paper considers the problem of the optimal input design for parameter estimtion in the ARMAX model in which the system and noise transfer function have the common denominator polynomial. Deriving the information matrix, in detail, for the assumed model structure and using the autocorrelation functin of the filtered input as design variables, it is shown that D-optimal input signal can be realized as an autoregressive moving average process. Computer simulations are carried out to show the standard-deviation reduction in the parameter estimtes using the optimal input signal.

• 센서학회지
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• 제14권6호
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• pp.402-408
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• 2005

This paper describes the optimal design of a multi-layered surface plasmon resonance sensors to meet various specifications and improve some physical parameters. Dip 3 dB bandwidth and depth were chosen as design parameters and the objective function was the norm of the difference between design parameters and target values. The design variables are thicknesses of each layer and to obtain the design parameters, the optical admittance method was employed. The (1+1) evolution strategy was employed as an optimization tool. By applying the proposed optimization procedure to a 3-layered sensor, the optimized design variables considerably improved the 3 dB bandwidth by 4.8 nm and the dip depth by 1.1 dB.