• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.182-188
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• 2006

In this study, we have designed the millimeter-wave passive imaging system which records energy that is reflected or emitted from the source and produces image. The lens and front-end of receiver appeared to be important in the system to detect input thermal noise signal. The lens for signal focusing has been designed by optical transfer function. Amplifier of the imaging systemhas been set up with 40dB in maximum gain, 5 dB in maximum noise figure, and 10GHz in bandwidth to enhance sensitivity for thermal noise and to receive it in wide-band width as well. The SBD MSS-20 141B10D diode has been used for the detector circuit to convert amplified millimeter-wave signals to DC output.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.442-446
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• 2004

Computer simulation of a swaging manufacturing process is presented in this paper. Commercially available software has been used to develop the simulation algorithm. Based on the experience gained from trial runs, simulation of a tube swaging process has been carried out. The material parameters "n" (strain hardening exponent) and "K" (plastic modulus) are obtained from actual tensile test measurements of the tube material. Two different geometries for the die and the tube have been used in this work and a comparison made. Numerical simulation of the swaging process has been performed using the commercially available HyperMesh(r) for pre-processing, LS-DYNA(r) for analysis and LS-TAURUS(r) for post-processing. Some of the results obtained from this study are compared with those available in the literature.

• The Optical Journal
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• s.110
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• pp.58-66
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• 2007

고기능 CMOS 이미지 센서는 현재 차재나 시큐리티 등의 응용을 목표로 실용화 개발이 활발히 이루어지고 있다. 그리고 정보통신으로의 응용도 가시광통신 등의 보급에 따라 이후 연구가 활발해질 것으로 생각된다. 바이오 의료 관계는 아직 연구단계에 있지만, 앞으로 고령화 사회가 도래할 것을 생각하면 필요한 기술이라고 할 수 있다. 단 실제 장착기술뿐 아니라 윤리적인 면도 포함하여 난제가 산재해있어 지금부터 착실한 연구개발이 필요하다. 앞으로의 발전에 기대가 된다. 본 고에서는 이러한 고기능 CMOS 이미지센서의 보고 예에 대해 차재.시큐리티 응용에서는 광다이나믹레인지화, 3차원거리계측에 대해, 정보통신기술응용에서는 광ID태그, 광무선LAN을 기술하겠다. 그리고 바이오의료응용으로서 바이오이미징과 인공시각에 대해서 서술하고, 마지막으로 앞으로의 전망에 대해서 정리하겠다.

• Journal of the Korean institute of surface engineering
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• v.20 no.1
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• pp.25-30
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• 1987

미국의 정부규격은 국방규격(Military Specification and Standard) 연방규격(Federal Specification Standard)이 있으며 금속표면처리에 관련된 규격인 전기도금규격, 아노다이징, 화성피막처리, 기타 코팅 규격은 40여종으로 되어있다. 이들 규격서와 표준서는 미국내 정부베이소 구매시의 금속표면처리 제품과 때로는 장비의 구입 계약시에 지침이 되고 있다. 전민간의 산업체와 일반 상품의 가공에 생산과 품질관리에 두루 적용되고 있어 국내 대미주 지역의 수출은 물론 표면처리 제품의 생산 공정에 활용-기여하고자 규격 주요내용의 기술과 구입방법을 소개하고져 한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.157-159
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• 2009

LED BLU(Back Light Unit), based on MCPCB(Metal Core Printed Circuit Board) with anodizing oxide dielectric layer and improved thermal dissipation property, are presented. Reflecting cups were also formed on the surface of the MCPCB such that optical coupling between neighboring chips were minimized for improving the photon extraction efficiency. LED chips were directly attached on the MCPCB by using the COB (Chip On Board) scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2624-2630
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• 2013

In LED chip packaging, die bonding is a very important process which fixes the LED chip on the lead flame to provide enough strength for the next process. During the process, inspection processes are very important to detect exact locations of dispensed epoxy dots and to determine bonding status of dies whether they are lies at exact positions with sufficient bonding strength. In this study, a useful machine vision based inspection system is proposed for the LED die bonder. In the proposed system, 2 cameras are used for epoxy dot position detection and 2 cameras are sued for die attaching status determination. New vision processing algorithm is proposed, and its efficiency is verified through required field experiments. Measured position error is less than $X:-29{\mu}m$, $Y:-32{\mu}m$ and rotation error:$3^{\circ}$ using proposed vision algorithm. It is concluded that the proposed machine vision based inspection system can be successfully implemented on the developed die bonding system.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.1
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• pp.1-16
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• 2023

Recently, the shift to next-generation wide-bandgap (WBG) power semiconductor for electric vehicle is accelerated due to the need to improve power conversion efficiency and to overcome the limitation of conventional Si power semiconductor. With the adoption of WBG semiconductor, it is also required that the packaging materials for power modules have high temperature durability. As an alternative to conventional high-temperature Pb-based solder, Ag sintering die attach, which is one of the power module packaging process, is receiving attention. In this study, we will introduce the recent research trends on the Ag sintering die attach process. The effects of sintering parameters on the bonding properties and methodology on the exact physical properties of Ag sintered layer by the realization 3D image are discussed. In addition, trends in thermal shock and power cycle reliability test results for power module are discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.2
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• pp.280-291
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• 2004

Apparel goods are classified by many criteria for ease of merchandising implementation. Fashion and basic goods are also an oucome oi classification. Previous studies pnvide some criteria by which apparel products can be classified into fushion and basic goods. Among those ciiteria, seasonality, fashionability, clothing types, complexity in pnduction, simplicity of style, pioducuon volume, degree of style change by season, could be listed. This study, first explored how apparel merchandisers and designers define fashion and basic goods in relation with those criteria. Definitions of fashion and basic goods were explored in terms of design elements (i.e., style, color, material), production volume, sales ratio, proportion in product assortment, and contribution to profit. The study adopted a qualitative approach by use of eighteen infepth interviews with menhandisers and designers. Six were from women＇s wear brand, Seven from men＇s wear brand, and 5 from casual wear brand. All the interviewees agreed that they are using the classification of basic vs. fashion goods. However, they are using diverse terms to indicate the basic and fashion goods. The interviewees defined each group based on its contribution to total sales or profit complexity in design, production volume, and style change by season. Basic goods had a higher level of production quantity, contribute more to profit simpler design, and less style change by season than fashion goods.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.2
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• pp.138-143
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• 2015

Purpose: The aim of this study was to compare the translucency of two different laminate ceramic veneers with and without glazing. Materials and methods: Ten millimeter side square-shaped specimens in 0.3 mm and 0.6 mm thick were fabricated for the following materials with and without glazing (n=80): A1 shade IPS e.maxPress (IEM) and Styleveneers (STV). The color coordinates (CIE $L^*a^*b^*$) of the specimens were measured with a colorimeter. The Translucency parameter (TP) was calculated from the color difference of the material on a black versus a white background. For comparisons between materials and between the 'not glazed' and 'glazed' groups, unpaired t-test was used to analyze the data (P=.05). Results: The TP ($Mean{\pm}SD$) of 'not-glazed' and 'glazed' group of IEM specimens at 0.3 mm thickness were $45.99{\pm}3.00$ and $49.53{\pm}2.28$ and the TP at 0.6 mm thickness were $32.82{\pm}2.59$ and $43.02{\pm}0.98$, respectively. Likewise, the TP of 'not-glazed' and 'glazed' group of STV specimens at 0.3 mm thickness were $47.03{\pm}3.65$ and $50.95{\pm}3.05$ and the TP at 0.6 mm thickness group were $34.48{\pm}1.28$ and $43.39{\pm}1.20$, respectively. As the glazing of ceramic veneer differed, the TP of each ceramic veneer showed statistically significant difference. But, the result between the products was not statistically different. Conclusion: Within the limitations of this study, we are concluded that the glazing process changed translucency of laminate ceramic veneers and the TP would not be affected by products.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.8-13
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• 2009

LED BLU(Back Light Unit), based on MCPCB(Metal Core Printed Circuit Board) with anodizing oxide dielectric layer and improved thermal dissipation property, are presented. Reflecting cups were also formed on the surface of the MCPCB such that optical coupling between neighboring chips were minimized for improving the photon extraction efficiency. LED chips were directly attached on the MCPCB by using the COB (Chip On Board) scheme.