• Title/Summary/Keyword: 김영기

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The LED PKG Analysis of Thermal Resistance Characteristics by Following Via hole and FR4 PCB Area (FR4 PCB면적과 Via hole에 따른 LED PKG 열 저항 특성 분석)

  • Kim, Sung-Hyun;Joung, Young-Gi;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1724-1725
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    • 2011
  • 본 논문에서는 LED 패키지의 방열문제를 해결하기 위해 FR4 PCB에 Via-hole을 형성함으로써 열전달 능력을 향상시키고자 하였다. 또한 FR4 PCB의 면적과 Via-hole 크기 및 수량을 변화를 주어 그에 따른 K-factor를 측정 하였으며 열 저항 특성을 분석하였다. 결과로서, Via-hole을 형성한 FR4 PCB의 경우 초기 면적이 증가함에 따라 열 저항 및 접합온도가 급격히 감소하는 특성을 보였으며 200 [mm2]에서 안정화 되는 특성을 보였다. 또한 PCB 면적 및 Via-hole을 형성함에 따라 광 출력이 최대 17% 향상 되었다. 따라서 접합온도 및 열 저항에 있어서 PCB면적의 증가 및 Via-hole을 구성함에 있어 열전달 능력을 향상시킬 수 있음을 확인하였다.

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Development of Virtual Reality Contents for Korean Sign Language Interpretation (수화 통역을 위한 VR 콘텐츠 개발)

  • Na, Kil-Hang;Lee, Byung-Ho;Kim, Jong-Hun;Kim, Jong-Nam;Jung, Young-Kee
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.690-695
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    • 2009
  • 본 논문은 영화, 방송, 애니메이션 등의 다양한 동영상 콘텐츠에 수화 애니메이션을 합성하여 동영상 콘텐츠를 청각 및 언어장애인들에게 이해시키기 위한 수화 통역 VR 콘텐츠 시스템을 제안하고자 한다. 제안된 시스템은 수화 사전에 있는 수화들을 3D 애니메이션으로 DB화하기 위해, 모션 캡처 시스템과 데이터 글러브를 사용하여 실제 사람처럼 자연스러운 애니메이션을 생성하였다. 최종적으로 동영상 콘텐츠의 자막이나 대본의 구문분석을 한 후, 이를 수화용 단어자막을 통해 수화 애니메이션을 DB에서 검색한 후, 실시간적으로 기존 동영상 콘텐츠와 동기합성을 하여 수화 통역 콘텐츠를 제공하는 VR 콘텐츠 시스템을 구현하였고 이 시스템을 동화용 애니메이션에 적용하였다.

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The Design of 6 inch Down-light by Optimization of the Optical and the Thermal Properties (광학적 열적 최적화를 통한 6인치 다운라이트 설계)

  • Kim, Sung-Hyun;Joung, Young-Gi;Seo, Bum-Sik;Yang, Jong-Kyung;Park, Dae-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.6
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    • pp.1178-1182
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    • 2011
  • The best methods for distribution controled of LED lighting fixtures is control to designed LED chip array, lens and reflector. However, lens design need distribution design to reflector for low-wattage LED lighting because of difficulty of production and reduction of light efficiency. In addition, it needs maximize of thermal performance to improve the efficiency and reliability of device. As a result, for the height of reflector 40[mm] and Inclination 25[$^{\circ}$], we can see the best distribution properties, and, in the thermal properties, junction temperature MCPCB 62.9 [$^{\circ}C$], FR4 PCB 89.6 [$^{\circ}C$], FR4 PCB from Via-hole is 63.1 [$^{\circ}C$]. it may improve for thermal properties for makes the Via-hole.

Microbiological Quantitative Assay of Pivampicillin.HCl (Pivampicillin.HCl에 관(關)한 연구(硏究) I -미생물학적(微生物學的) 정량법(定量法)-)

  • Lee, Han-Pyo;Kim, Chung-Kyu;Sim, Young-Ki;Yong, Kun-Ho
    • Journal of Pharmaceutical Investigation
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    • v.3 no.1_2
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    • pp.16-22
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    • 1973
  • Biological determination of Pivampicillin hydrochloride was examined and an available method has been established. Unhydrolyzed Pivampicillin hydrochloride has no antibacterial activity, but it exhibits an antibacterial activity hydrolyzed with liberation of ampicillin by nonspecific enzymes present in blood and tissues from various species in vitro and in vivo. Using these properties, Pivampicillin hydrochloride can be determined as ampicillin by use of an agar-diffusion method with Bacillus subtilis as the assay organism.

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Design and Implementation of CoAP based Cloud-IoT Architecture (CoAP 기반 클라우드 환경 IoT 구조 설계 및 구현)

  • Park, Young-Ki;Yang, Hyun-Sik;Kim, Young-Han
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.3
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    • pp.119-127
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    • 2015
  • In the IoT(Internet of Things) environment, methods that user can access sensor node directly to collect sensing data or manage sensor in a gateway have a limitations. To solve this problem, cloud based sensor network architectures are proposed. In this paper, we proposed CoAP based IoT architecture that a lightweight gateway is used for data gathering instead of using a heavy traditional one and users can request sensing data through IoT applications running in the cloud environment and analyze signaling message cost. By doing so, our system can reduce message cost compared to the traditional gateway based system.

Growth and Interdiffusion Behavior of Copper MOCVD Films on Au/Si(100) Substrates (Au/Si(100)기판상에서 Cu-MOCVD 박막의 성장과 상호확산거동)

  • Kim, Jeong-Yeol;Lee, Yeong-Gi;Park, Dong-Gu;Jo, Beom-Rae
    • Korean Journal of Materials Research
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    • v.7 no.8
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    • pp.668-678
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    • 1997
  • Si(100)기판상에 여러 가지 두께의 Au박막을 선행 증착(pre-deposition)한 후, 각각의 Au박막상에서의 Cu-MOCVD박막의 초기 핵생성과 성장 기구를 고찰하였고, 또한 각 계면에서의 상호 확산 거동을 여러가지의 분석 장비를 이용하여 조사하였다. 30$\AA$두께의 Au 박막은 수소 가스 분위기중의 열처리에 의하여 평탄한 표면 상태에서 불연속의 응집된 도상(island)형태로 변화(Si 전체 표면중 약 20%)하였다. 반면에 1500$\AA$두께의 Au박막상에서 성장한 Cu-MOCVD박막은 두께 증가에 따른 미세구조의 차이, 즉 Cu박막중으로 Au원자의 확산여부는 Au박막에 유기되는 열응력(thermal stress)을 완화하는 과정에서 일어난 결과이다.

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Development of Potato Virus Y Resistant Tobacco Plant by Transformation of the Untranslatable Viral Coat Protein Encoding cDNA (감자 바이러스 Y 비전이성 외피단백질 cDNA의 형질전환에 의한 바이러스 저항성 연초품종 개발)

  • 이청호;이영기;강신웅;박성원;김상석;박은경
    • Journal of the Korean Society of Tobacco Science
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    • v.19 no.2
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    • pp.117-123
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    • 1997
  • Viral coat protein (CP) encoding cDNA with artificial start and stop codons was synthesized by reverse-transcriptase polymerase chain reaction (RT-PCR) from the Korean isolate of potato virus Y-vein nectrosis strain (pVY-VN). To make PVY CP cDNA to untranslatable form, three stop codons were inserted near the start codon by "megaprimer-PCR" method. The untranslatable CP cDNA was subcloned to plant expression vector and transferred to N. tabacum cv. NC82 by Agrobacterium-mediated transformation. Highly resistant plants to PVY infection were screened, based on symptom development after mechanical virus inoculation. By genomic PCR and Southern blot analysis, one or more copies of the untranslatable CP gene were found in all transformants. From northern blot analysis, highly resistant transgenic lines had very low level of CP transcript but susceptible lines had high level, suggesting resistance to PVY infection should be related to RNA-mediated mechanism.mechanism.

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Optimal Growth Conditions for Carotenoid Pigment Production from marine Microorganism (해양미생물로부터 카로테노이드 색소의 생산을 위한 최적조건)

  • 정영기;김태수;정명주;류병호;주우홍;박정욱
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.6
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    • pp.1239-1243
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    • 1999
  • The optimal medium composition for the production of carotenoid pigment from Haloarcular sp. EH 1 as a dietary for fishes were 1.0% sucrose, 1.0% yeast extract, 25% sodium chloride, 0.3% sodium citrate, 0.2% potassium chloride, 2.0% magnesium sulphate, 0.002% ferric sulphate(pH 7.0). The incubation temperate, aeration rate and agitation speed were 40oC, 100ml medium/500ml vol. shaking flask, and 180 rpm/min. The carotenoid pigment production was highest after 5 days of incubation with the light.

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Dynamic Modeling and Simulation of a Hybrid Heat Pump (하이브리드 열펌프 동적 모델링 및 시뮬레이션)

  • Shin, Younggy;Kim, Jae Hyun;Yoo, Byeong Jun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.7
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    • pp.406-412
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    • 2013
  • A hybrid heat pump is under development with the goal of utilizing 120% of primary energy resources. A plate heat exchanger is added between the compressor and air-cooled condenser of an ordinary heat pump to heat water. For successful operation of the heat pump, it is necessary to develop a control algorithm under various operating conditions. As a virtual test bed for that purpose, a dynamic model has been developed, to simulate its dynamic behavior. It was modeled in transient one-dimensions, with varying phase lengths considered. The model was implemented in Matlab and Simulink. Simulation results were effectively applied to design a control algorithm. They also provided physical insight into how to design and operate the system.

Estimation of Emission and Factors of the Greenhouse Gases from LNG Combustion Facilities (LNG 연소시설의 온실가스 배출계수 산출 및 배출량 산정)

  • Jang, Young-Gi;Choi, Sang-Jin;Kim, Gwan;Song, Gi-Bong;Kim, Ho-Jung;Hong, Young-Sil;Jung, Mi-Suk
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.219-220
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    • 2003
  • 최근 석유, 석탄을 사용하는 연소시설이 황산화물, 먼지가 배출되지 않는 LNG(Liquefied Natural Gas)로 연료를 전환하고 있다. 점차적으로 LNG 사용이 증가함에 따라 LNG에 의한 대기오염에 대한 관심이 높아지고 있으며, 최근에는 온실가스에 대한 관심도 높아지고 있다. 따라서 털 연구에서는 LNG연소에 의한 온실가스 배출계수와 국내 온실가스 배출량을 연소시설별로 산출하고자 한다. (중략)

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