• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1660-1665
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• 2003

On this study, we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite cantilever plate by each aspect ratio. A finite element analysis on the CFRP laminated composite cantilever plate using orthogonal array is carried out, and the results are compared with those obtained by modal testing.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권4호
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• pp.213-219
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• 2000

In this paper, a controller design method is proposed for haptic interface considering transparency and robust stability. For this, a performance index for the transparency as performance measure is defined in the points of impedance matching and the optimal solution which is minimizing the performance index is obtained by solving H2 optimal problem. In haptic interface, the modeling uncertainties can be restricted to that of haptic device. To implement the robust stabilizing haptic controller to the uncertainties of haptic device, a robust stable condition using H$\infty$ norm from small gain theorem is proposed. To verify the effectiveness of the proposed haptic controller design scheme, numerical examples and experimental results are illustrated for virtual wall consisting of stiffness and damping factor.

• 한국전기전자재료학회논문지
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• 제22권3호
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• pp.257-261
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• 2009

In this study, we have researched the optimum design method of the lenticular lens sheet for 3D displays on a TFT-LCD panel, to offer a more stable stereoscopic image, improved 3D quality, and a wider viewing zone. Especially, we have defined the viewing zone width (a parameter denoted as Z) to apply it to the optimum design. The results of this new design method have been compared with the existing design method. As a result, it is revealed that the proposed design method improves the stereoscopic image quality by reducing the black matrix zone width.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1438-1441
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• 2005

To establish of standard technique of nano-length measurement in 2D plane, new AFM system has been designed. In this system, measurement uncertainty is dominantly affected by the Abbe error of XY scanning stage. No linear stage is perfectly straight; in other words, every scanning stage is subject to tilting, pitch and yaw motion. In this paper, an AFM system with minimum offset of XY sensing is designed. And XY scanning stage is designed to minimize rotation angle because Abbe errors occur through the multiply of offset and rotation angle. To minimize the rotation angle optimal design has performed by maximizing the stiffness ratio of motion direction to the parasitic motion direction of each stage. This paper describes the design scheme of full AFM system, especially about XY stage. Full range of fabricated XY scanner is $100um\times{100um}$. And tilting, pitch and yaw motion are measured by autocollimator to evaluate the performance of XY stage. Using this AFM system, 3um pitch specimen was measured. As a result, the uncertainty of total system has been evaluated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.923-928
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• 1993

Genetic algorithms are powerful optimization methods based on the mechanism of natural genetics and natural selection. Genetic algorithms reduce chance of searching local optima unlike most conventional search algorithms and especially show good performances in complex nonlinear optimization problems because they do not require any information except objective function value. This paper presents a new model based on sexual reproduction in nature. In the proposed Sexual Reproduction model(SR model), individuals consist of the diploid of chromosomes, which are artificially coded as binary string in computer program. The meiosis is modeled to produce the sexual cell(gamete). In the artificial meiosis, crossover between homologous chromosomes plays an essential role for exchanging genetic informations. We apply proposed SR model to optimization of the design parameters of Single-sided Linear Induction Motor(SLIM). Sequential Unconstrained Minimization Technique(SUMT) is used to transform the nonlinear optimization problem with many constraints of SLIM to a simple unconstrained problem, We perform optimal design of SLIM available to FA conveyer systems and discuss its results.

• 한국생산제조학회지
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• 제23권5호
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• pp.456-464
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• 2014

Commercial vehicle drivers typically feel more fatigued compared to general-public drivers. because they spend longer periods of time driving and experience more rough road conditions. This study showed that the application of a magnet, a linear spring, and a seat suspension with nonlinear characteristics was the optimal design to increase comfort while driving. The resonant frequency for the optimal design suspension was 2.8 Hz, and the stiffness was analyzed through displacement-load experiments. Vibration transmissibility was analyzed by suspension stiffness and the existing dynamic compression. The magnetic spring type was at 0.875. As a result, the X-type magnetic spring performed better than the existing spring at 0.729.

• Journal of Biosystems Engineering
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• 제15권4호
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• pp.355-364
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• 1990

• 전산구조공학
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• 제8권1호
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• pp.39-49
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• 1995

• 조명전기설비학회논문지
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• 제19권1호
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• pp.143-147
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• 2005

본 연구에서는 희토류 자석편을 이용한 이중 회전자를 갖는 축방향 자속형 브러시리스 DC 전동기를 설계한다. 이러한 종류의 전동기는 반경방향 자속형에 비해 축방향 길이가 짧고 조립이 용이한 장점이 있다. 충분한 토크를 얻기 위해서 NdFeB 자석이 이용되며 생산 비용을 고려하여 자석은 세그먼트로 만들어 진다. 이 전동기를 설계하기 위해 자기 등가회로 모델이 이용되었고, 정확한 파라미터를 얻기 위해 3차원 유한요소법을 이용하여 공극 자속밀도를 구하였다. 최적화된 설계 변수들은 유전 알고리즘을 이용하여 구하였다. 시뮬레이션결과로부터 자석에 따른 설계의 지침과 타당성을 확인하였다.

• 에너지공학
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• 제27권4호
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• pp.13-19
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• 2018

본 연구에서는 위상최적화에 기초한 발전설비용 버터플라이 밸브 디스크 부품의 경량설계가 수행되었다. 이때 상용 유한요소해석 소프트웨어가 사용되었으며 기존 상용 밸브 디스크의 외형을 유지시키면서 내부의 불필요 공간을 제거하여 경량구조를 갖도록 하였다. 먼저 밸브 디스크의 원판과 브라켓을 분리하여 각각 최적설계 하였다. 최적의 형상이 선정되면 이들을 조립하여 3차원 경량 밸브 디스크 모델을 완성하였다. 이후 이 모델에 설계 압력을 적용하여 유한요소해석 후 구조적 안전성을 확인하였다.