• 한국생산제조학회지
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• 제20권5호
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• pp.582-588
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• 2011

This study was aimed at the design of the dies for the unified shaft joint using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation, 'Deform-3d' and 'Eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the process analysis, we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of die design, we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for multi-forging has been developed.

• 정보처리학회논문지B
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• 제14B권6호
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• pp.437-444
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• 2007

본 논문의 목적은 기존의 모션 캡쳐 기반 애니메이션을 모바일 임베디드 시스템의 적은 메모리와 낮은 계산력에 적합하게 개조하는데 있다. 모바일 임베디드 시스템의 메모리를 효율적으로 사용하기 위한 방안으로서, PC 상에서 모션 캡쳐 데이터베이스를 압축하고, 압축된 모션캡쳐 데이터베이스를 모바일 임베디드 시스템에서 조금씩 압축 해제하고 사용 직후 삭제하는 패러다임을 제안한다. 이러한 목적으로 사용될 모션 캡쳐 데이터베이스 압축 기법으로서, 다항식 정합법을 활용하여 캡쳐된 운동 랜더링 파라미터의 데이터베이스를 축소하는 방법을 제안한다. 그리고 성능향상을 위해서 다항식 정합 함수를 최적화하는 방안도 함께 제안한다. 이렇게 설계된 다항식 정합법에 기반한 데이터 압축 방식을 사용하여, 상용화된 모바일 임베디드 시스템에서 효율적인 모션 캡쳐 기반 애니메이션 제작을 시현한다.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1219-1226
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• 2000

An efficient method is developed for plunger thermal cycle analysis in repeated forming process of the TV glass. The plunger undergoes temperature fluctuation during a cycle due to the repeated contact and separation from the glass, which attains a cyclic steady state having same temperature history at every cycle. Straightforward analysis of this problem brings about more than 80 cycles to get reasonable solution, and yet hard to setup stopping criteria due to extremely slow convergence. An exponential fitting method is proposed to overcome the difficulty, which finds exponential function to best approximate temperature values of 3 consecutive cycles, and new cycle is restarted with the fitted value at infinite time. Numerical implementation shows that it reduces the number of cycles dramatically to only 6-18 cycles to reach convergence within 10 accuracy. A system for the analysis is constructed, in which the thermal analysis is performed by commercial software ANSYS, and the fitting of the result is done by IMSL library. From the parametric studies, one reveals some important facts that although the plunger cooling or the glass thickness is increased, its counter part in contact is not much affected, duo to the low thermal conductance of the glass.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.697-702
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• 2008

2007년 현재 전 세계적으로 모바일 기기 사용 인구수는 약 30억 명으로 전 세계 PC사용자 수의 두 배에 달한다. 모바일 디스플레이는 작은 크기로 인해 휴대성이 높은 등 많은 장점을 갖고 있지만, 소형화와 전력 절감을 위해 얇은 디스플레이 패널과 저성능 이미지 센서를 채택하는 등 대형 디스플레이에 비해 색상표현력이 떨어질 수 밖에 없다. 따라서 본 연구에서는 모바일 디스플레이 자체의 성능이 떨어지더라도 사람의 눈에 인식되기 용이하게 색채이론에 입각해 이미지 환경을 변경하는 방법을 제안한다. 사람의 눈은 망막상의 색신경이 어떤 색의 자극을 받게 되면 그 색의 보색에 대한 감수성이 높아지고, 명암차이가 분명한 색상들을 나열하면 반대 밝기에 대한 민감도가 높아진다. 사람의 시각신경에서 느끼는 색채에 대한 감성적인 색상처리(RGB의 채도를 증가 시키거나 다이나믹 레인지의 확장과 보색대비의 강조에 따른 변화)를 통하여 얻은 데이터를 비교 분석 한다. 그 결과 적용 전의 이미지보다 적용 후의 이미지의 인식률이 높아지고 화질이 향상됨을 알 수 있다.

• 한국의류학회지
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• 제24권5호
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• pp.714-723
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• 2000

The purpose of this study is to develop functional and sensible brassiere for middle-aged women. As a methodology, engineering design process, especially, QFD(Quality Function Deployment) was adopted to translate consumer's needs into product design parameters. Wearing tests of commercial brassiere were performed for the development o subjective measurement scale. The environmental condition was controlled at 28$\pm$1$^{\circ}C$, 65$\pm$3%RH. As results, subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. Regression equations with the subjective evaluation descriptors were developed for the prediction of wearing comfort of brassiere. (R2=.82) The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap.

• 한국소음진동공학회논문집
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• 제27권2호
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• pp.139-147
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• 2017

Acoustic performance of splitter silencers was investigated by using 3-dimensional commercial software and experiments. Flow resistivity of sound absorbing material was indirectly estimated by using an impedance tube setup and a curve fitting method. In addition the acoustic impedance of perforated plate was determined by an empirical formulation. Such properties have been used as input parameters in the commercial software. The prediction for a splitter silencer with 1000 mm length was compared with the experimental result. The numerical method is then applied to identify the effects of number of splitters, length of splitters, absorptive material density, and porosity of a perforated plate on the performance of the splitter silencers. As the number and length of splitter increases, the acoustic performance significantly increases. Although the increase of density of absorptive material also increase the acoustic performance, a change in the density over a certain level hardly affect it. The increase of porosity will enhance the performance especially at higher frequencies.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.876-879
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• 2007

대규모 복합시설물의 내부 도시는 상업 및 공간 구조에 따라 거리의 보행 인구에 영향을 미치다. 또한 거리의 보행 인구는 상업 활동을 활성화 시키면서 보행량이 증가하면 상가시설의 매출액이 증가하고, 이러한 보행 유도인구의 증대는 상업시설의 입대료와 상가의 가치를 증진시킨다. 그러므로 대규모 복합시설물에서 보행량의 위상학적 접근성과 상가의 입지 특성에 따라 가치가 결정되어 진다. 이에 따라 본 연구에서는 정량적 평가 도구로 공간 위상학적 분석에 기반을 둔 공간구문론(Space Syntax)을 통해 개별 공간이 위상학적 속성을 분석하고 동선에 분포 및 패넌을 예측하여 상가의 입지가치를 평가하고자 한다. 또한 효과적인 입지 전략을 추진하기 위해 가로의 내부화에 적합한 내부 도시계획 및 설계 측면에서 시사점을 제시하고자 한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 제4회 압출 및 인발가공 심포지엄
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• pp.45-53
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.82-88
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• 2002

Copper bus-bar is made by drawing process and used in many part of industry. Ohen design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper it is analyzed to determine shrink fit value by shrink fit analysis program which is used with APDL/UIDL language in a commercial FEM package, ANSYS. The shrink fit analysis has been developed that enables optimal desist of the dies taking into account the elastic deflections. Elastic deflection is generated in shrink fitting the die inserts and that caused by the stresses generated using DEFORM software for drawing process analysis. This data can be processed as load input data fir a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.45-46
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• 2017

The operating characteristics of power MOSFETs greatly vary depending on the junction temperature. A PSpice thermal model is implemented to simulate the temperature characteristics of the power MOSFETs in this paper. A thermal model is derived that can be applied online in PSpice simulations and PSpice parameters are reconstructed using a curve fitting from commercial data sheets. The implemented PSpice model is applied to the buck converter and the validity of the model is verified through experiments.