• Title/Summary/Keyword: Lee Joon Gu

검색결과 328건 처리시간 0.026초

PET 기판 위에 증착된 ITO 투명전도막의 전기적.광학적 특성 (Electrical and Optical Properties of ITO Thin Films Prepared on the PET Substrate)

  • 이재형;정학기;임동건;양계준;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.176-179
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    • 2003
  • ITO films on PET substrate were prepared by DC magnetron sputtering method using powdery target with different deposition conditions. In addition, the electrical and optical properties were investigated. As the sputtering power and working pressure were higher, the resistvity of ITO films increased. The optical transmittance deteriorated with increasing sputtering power and thickness. As the working pressure increased, however, the optical transmittance improved at visible region of light. From these results, we could deposited ITO films with $8{\times}10^{-3}\;{\Omega}-cm$ of resistivity and 80% of transmittance at optimal conditions.

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X선영상증배관의 상대변환계수 측정에 관한 검토 (The Study on Measurement of Relative Conversion Factor in X-ray Image Intensifier)

  • 김성철;신성일;이선숙;허준;김성수
    • 대한방사선기술학회지:방사선기술과학
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    • 제20권2호
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    • pp.28-33
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    • 1997
  • For the Evaluation of X-ray image intensifier, we measured radiation dose at input of I. I., brightness and fluorescence at output of I. I. by using X-ray exposure meter, optometer and fluorescence meter for the relative conversion factor. Especially, by using fluorescence meter, we could easily get relative conversion factor without having regulated machine by JIS. Since using, the quality of image intensifier is going down. Consequently, it needs continuous quality maintenance.

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건축내장재의 흡음 특성 (Sound Absorption Characteristics of Building Interior Decoration Materials)

  • 강대준;이재원;구진희;박형규
    • 한국소음진동공학회논문집
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    • 제17권3호
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    • pp.201-206
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    • 2007
  • It is important to consider the sound absorption characteristics of building interior decoration materials when we design a building and simulate acoustics in a room. The purpose of this study is to accumulate acoustic data on building interior decoration materials and give a basic data for improving the sound absorption performance by testing the sound absorption coefficients of 9 types of ceiling materials, 14 types of wall papers and 20 types of floor papers.

자동차 소음기 특성 및 배기소음 개선 방안 (Characteristics of Vehicle Mufflers and Improvement Measures of Vehicle Exhaust Noise)

  • 이재원;강대준;구진회
    • 한국소음진동공학회논문집
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    • 제18권12호
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    • pp.1224-1228
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    • 2008
  • Vehicles are exhausting various environmental pollutions such as exhaust gas, noise, and so on. This study investigates only noise problems by vehicles, especially the vehicle exhaust noise. It is known that the exhaust noise among vehicle noises is over 20% of those when the vehicle is suddenly accelerated or normally accelerated. In this study, we mainly investigate the exhaust noise of vehicle so that we intend to show the measures to decrease the illegal tuning mufflers and reduce the exhaust noise problems. In the conclusion, we suggest the new appropriate standard to control the tuning mufflers and reduce the exhaust noise induced by vehicles.

Intramedullary Spinal Cord Lipoma Extending from the Cervicomedullary Junction to the Upper Thoracic Cord

  • Lee, Deok-Gu;Yoon, Seok-Mann;Shim, Jai-Joon;Bae, Hack-Gun
    • Journal of Korean Neurosurgical Society
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    • 제38권1호
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    • pp.71-73
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    • 2005
  • A case of intramedullary spinal cord lipoma is presented. A one month-old male infant presented with irritability and weakness on his upper extremities. A magnetic resonance[MR] image of the cervical spine demonstrated a well defined, high signal intensity lesion on both T1 and T2-weighted MR images and suppression on the fat saturation sequence. The tumor mass extended from the foramen magnum to T2 vertebra level. Ventral displacement of the spinal cord with kinking of the cervico-medullary junction was evident on the T2-weighted sagittal image. Partial resection of the tumor mass through laminoplastic laminotomy from C1 to T2 resulted in improved motor weakness on his upper extremities.

초대형 해상 크레인의 선체구조 강도평가 (The Hull Strength Assessment for Heavy Lift Floating Crane)

  • 강용구;백승훈;이준혁;박우진;심대성;안용택;조병삼
    • 대한조선학회 특별논문집
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    • 대한조선학회 2015년도 특별논문집
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    • pp.1-8
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    • 2015
  • In general, the strength assessment for heavy lift vessel is carried out under two stages. The first stage is to comply with the requirement of KR (Korean Register of Shipping) Steel Barges and Rules for Classification of Steel Ships. At the second stage, the structural strength analysis by Finite Element Method is peformed. This paper describes the strength assessment considering various loads for the heavy lift vessel of sheerleg type.

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Nickel Doping on Cobalt Oxide Thin Film Using by Sputtering Process-a Route for Surface Modification for p-type Metal Oxide Gas Sensors

  • Kang, Jun-gu;Park, Joon-Shik;An, Byeong-Seon;Yang, Cheol-Woong;Lee, Hoo-Jeong
    • Journal of the Korean Physical Society
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    • 제73권12호
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    • pp.1867-1872
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    • 2018
  • This study proposes a route for surface modification for p-type cobalt oxide-based gas sensors. We deposit a thin layer of Ni on the Co oxide film by sputtering process and annealed at $350^{\circ}C$ for 15 min in air, which changes a typical sputtered film surface into one interlaced with a high density of hemispherical nanoparticles. Our in-depth materials characterization using transmission electron microscopy discloses that the microstructure evolution is the result of an extensive inter-diffusion of Co and Ni, and that the nanoparticles are nickel oxide dissolving some Co. Sensor performance measurement unfolds that the surface modification results in a significant sensitivity enhancement, nearly 200% increase for toluene (at $250^{\circ}C$) and CO (at $200^{\circ}C$) gases in comparison with the undoped samples.

GIS 및 산림기본통계를 이용한 산림정보지도 제작 (Forest Information Mapping using GIS and Forest Basic Statistics)

  • 박준규;이종신
    • 한국산학기술학회논문지
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    • 제19권8호
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    • pp.370-377
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    • 2018
  • 현재 우리나라는 산림선진국(독일, 일본, 오스트리아 등)과 비교해도 부족하지 않을 만큼 산림경영, 산림조사 및 산림관리 등 산림분야에서 앞서 나가고 있는 상황이다. 그러나 체계적이며, 고도화된 산림관리 방안 수립 및 관련 연구는 부족하고, 실질적이면서 복합적인 분석을 위한 GIS로의 구축도 미흡한 상황이다. 이에 본 연구에서는 산림분석을 효율적으로 수행하기 위해 GIS를 기반으로 산림기본통계자료(2010년, 2015년)를 지도화하여 산림정보지도를 제작하였다. 그 결과 세부 행정구역별 산림면적, 임목축적, 평균임목축적, 산림률을 시각적 효과가 극대화된 지도로 제작할 수 있었으며, 시계열적인 변화 또한 체계적으로 분석할 수 있었다. 산림면적은 고성군, 세종특별시, 철원군, 연천군, 대전광역시 동구, 서울특별시 구로구에서만 증가하고, 그 이외 지역에서는 모두 감소하는 것을 알 수 있었으며, 임목축적은 대부분 지역에서 증가한 반면, 2011년 산불피해를 입은 울진군을 비롯하여 울릉군, 서울특별시 노원구, 서울특별시 강동구, 서울특별시 중구에서만 감소하는 것을 알 수 있었다. 평균임목축적은 4개 행정구역을 제외한 대부분의 지역에서 증가하는 것을 알 수 있었으며, 산림률의 경우 고성군, 연천군, 공주시, 부산광역시 동구, 대구광역시 서구 등 10개 지역을 제외한 대부분의 지역에서 감소한 것을 알 수 있었다. 향후, 본 연구를 바탕으로 보다 소규모의 행정구역과 더 많은 시기를 대상으로 산림정보지도를 제작하고 분석을 진행할 예정이다.