• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.327-337
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• 2000

In this paper, the design sensitivity formula for the control of the transient temperature distribution is developed using the direct differentiation method, and used for the optimal design of induction heating coil position. The temperature distribution is calculated using the heat source of the induced eddy current and heat diffusion equation. The physical property variations of the workpiece depending on the temperature are considered. The eddy current distribution and the temperature distribution are calculated with the 2D finite element procedure. The adjoint variable technique is employed in expressing the design sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the workpiece. The numerical example shows that the proposed design sensitivity analysis for the control of the transient temperature distribution is very useful and practical in the optimal design of induction heating coils.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.268-271
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• 2003

There are several methods for the design of 2D filter. Notable among them is McClellan transform method. This transform allows us to obtain a high order 2D FIR filter through mapping the 1D frequency points of a 1D prototype FIR filter onto 2D frequency contours. We design 2D filter using this transform. Then we notice for mapping deviation of the 2D filter. In this paper, Quadratic programming (QP) method allows us to obtain coefficients of McClellan transform. Then we compare deviation of QP method with least-squares(LS) method. Elliptic filter is used for comparison. The optimal cutoff frequencies of a 1D filter are obtained directly from the QP method. Also several problem of LS method are solved.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권3호
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• pp.262-266
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• 2005

In this paper, in order to enhance thrust of slotless type Permanent Magnet Linear Synchronous Motor, an optimal design is achieved by combining a genetic algorithm with 3D space harmonic method. In the case of multi-objective functions, the ratio of thrust/weight and thrust/volume are increased by $\7.56[%]l\;and\;7.98\[%]$, respectively. Thus, miniaturization and lightweight were realized at the same time.

• 디자인학연구
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• 제17권3호
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• pp.123-132
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• 2004

이 논문은 한국의 환경에 맞는 한국형 고속전철 디자인 방법과 그 디자인 과정을 한국의 환경에 맞추어 연구하고, 그로부터 이루어진 결과를 바탕으로 공기역학적 최적화에 초점을 둔 시제차량(prototype test train, HSR 350${\times}$)의 외형형상 디자인 개발의 형태로 밝힌다. 이는 고속전철 기술개발 사업의 일환으로 1996년부터 2002년까지 6년간 진행되었다. 그 사업의 최종 결과로 제작된 시제차량은 두개의 동력차와 두개의 동력대차 그리고 세 개의 객차로 구성되어 있으며, 2003년에 경부고속전철 선로에서 최고 380km/h까지 성공적으로 시험을 마쳤다. 그러나 시제차량의 디자인 개발과 제작에서는 턱없이 부족한 진행일정과 경제적 제한으로 많은 것들이 유보되었다. 따라서 시제차량에서는 구현되지 못하였으나 향후 미래에 필요성을 염두에 두어, 시제차량과 병행하여 상용차량과 차세대 차량을 위한 보다 개선된 개념 디자인 연구가 진행되었다.

• Composites Research
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• 제35권5호
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• pp.340-346
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• 2022

본 연구에서는 복합재료 블레이드에 대한 최적 구조설계 프레임워크를 구성하고, 이를 헬리콥터 블레이드에 적용하여 최적 구조설계를 수행하였다. 단면 형상의 경우 C형 및 D형 스파를 선택할 수 있게 구성하였으며, 최적설계 프레임워크는 유전자 알고리즘과 입자 군집 최적화 알고리즘을 결합한 PSGA를 활용하였다. 단면의 기하학적 모델링은 B-spline을 이용하여 구현하였고, 유한요소 모델 생성 프로그램 Gmsh를 통해 단면 유한요소모델을 만든 뒤 단면 해석 프로그램인 Ksec2D를 사용하여 구조해석 결과를 도출하였다. 본 최적설계 프레임워크를 HART II 블레이드에 적용하여 최적 구조설계를 수행한 결과, C형 스파 모델은 기준 형상 대비 무게 7.39%, D형 스파 모델은 6.65% 감소하였으며, 이때 전단중심은 모두 공력중심과 인접한(5% 이내) 결과를 도출하였다. 본 연구를 통해 일반적인 헬리콥터 블레이드의 단면에 적용할 수 있는 최적 구조설계 프레임워크의 유효성을 확인하였다.

• Advances in Computational Design
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• 제3권1호
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• pp.49-69
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• 2018

This paper shows an optimal design for reinforced concrete rectangular combined footings based on a criterion of minimum cost. The classical design method for reinforced concrete rectangular combined footings is: First, a dimension is proposed that should comply with the allowable stresses (Minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity withstand by the soil); subsequently, the effective depth is obtained due to the maximum moment and this effective depth is checked against the bending shear and the punching shear until, it complies with these conditions, and then the steel reinforcement is obtained, but this is not guaranteed that obtained cost is a minimum cost. A numerical experimentation shows the model capability to estimate the minimum cost design of the materials used for a rectangular combined footing that supports two columns under an axial load and moments in two directions at each column in accordance to the building code requirements for structural concrete and commentary (ACI 318S-14). Numerical experimentation is developed by modifying the values of the rectangular combined footing to from "d" (Effective depth), "b" (Short dimension), "a" (Greater dimension), "${\rho}_{P1}$" (Ratio of reinforcement steel under column 1), "${\rho}_{P2}$" (Ratio of reinforcement steel under column 2), "${\rho}_{yLB}$" (Ratio of longitudinal reinforcement steel in the bottom), "${\rho}_{yLT}$" (Ratio of longitudinal reinforcement steel at the top). Results show that the optimal design is more economical and more precise with respect to the classical design. Therefore, the optimal design presented in this paper should be used to obtain the minimum cost design for reinforced concrete rectangular combined footings.

• 대한수학회지
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• 제31권4호
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• pp.709-715
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• 1994

The aim of of the study is a powerful test for the discrimination and therefore an optimal desin for that purpose. This problem is studied by Chernoff ([5]) and used in Chernoff ([6]) for accelerated life tests using the exponential distribution for life times. The approach used here is similar to that suggested by Lauter ([10]) and used in Chaloner ([3]) and Chaloner and Larntz ([4]) where it is motivated using Bayesian arguments. The approach taken in this paper the loss function $L(\cdot)$ evaluating a test procedure and a design d.

• 전기학회논문지
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• 제65권5호
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• pp.769-772
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• 2016

In this paper, the overhang structure was applied to the axial flux permanent magnet (AFPM) motor. This paper describes the overhang effect in the AFPM motor. Moreover, the overhang effect was analyzed according to the different overhang length and an optimal overhang structure was proposed. Finally, the proposed structure was applied to design, analysis and experiment of prototype motors. Through the comparison between 3D finite element analysis results and experimental ones, the validity of proposed structure is clarified.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.225-230
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• 2001

In this paper, a method for optimal design of PID controller using the immune algorithm(IA) has been proposed to improve the stability of A.C.-D.C. power system. The process of this study is composed of formulation of basic controls on HVDC transmission system, mathematical model preparation for stability analysis, and supplementary signal control by an optimal PID controller using the IA. The dynamic property was verified through computer simulations regarding transient stability.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.247-254
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• 2008

The primary objective of this research is to develop an efficient design and optimization methodology for SRM Wagon Wheel Grain and to develop of software for practical designing and optimization of Wagon Wheel grains. This work will provide a design process reference guide for engineers in the field of Solid Rocket Propulsion. Using these proposed design methods, SRM Wagon Wheel grains can be designed for various geometries, their optimal solutions can be found and best possible configuration be attained thereby ensuring finest design in least possible iterations & time. The main focus is to improve computational efficiency at various levels of the design work. These have been achieved by the following way. a. Evaluation of system requirements and design objectives. b. Development of Geometric Model of Wagon Wheel grain configuration. c. Internal ballistic performance predictions. d. Preliminary designing of the Wagon Wheel grain configuration involving various independent geometric variables. e. Optimization of the grain configuration using Sequential Quadratic Programming f. In depth analysis of the optimal results considering affects of various geometric variables on ballistic parameters and analysis of performance prediction outputs have been performed g. Development of software for design and optimization of Wagon Wheel Grain. By using these proposed design methods, SRM Wagon Wheel grains can be designed by using geometric model, their optimal solutions can be found and best possible configuration be attained thereby ensuring finest design.