• Title/Summary/Keyword: 서수

검색결과 698건 처리시간 0.03초

피해가 발생된 휨벽체의 내진보강에 관한 연구 (Retrofit Method of Damaged Flexural Wall)

  • 서수연;이용택;이현호;이리형;천영수;양지수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.811-816
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    • 2002
  • An experimental work is performed to evaluate the retrofit method of damaged flexural walls. For two flexural walls damaged up to almost failure, reinforcements yielded and concrete below height of 1d are replaced with new reinforcements and steel fiber concrete, respectively. In order to evaluate the effectiveness of Aramid sheet for retrofitting walls, Aramid sheet is also, attached to longitudinal direction and rolled horizontal direction of one wall specimen. Horizontal cyclic loads are applied to the top of the specimen with constant axial load. Test result showed that retrofitting with steel fiber concrete after replacing reinforcements can not afford to recover 100% of the wall capacity before damage. However, the capacity of walls could be sufficiently strengthened by using Aramid sheet.

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미시적인 IGBT 소자 모델링과 회로동작 시뮬레이션 (Micro IGBT Device Modeling and Circuit Simulation)

  • 서영수;백동현;임영배;김영춘;조문택;서수호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.562-564
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    • 1994
  • IGBT devices have the best features of both power MOSFETs and power bipolar transistors, i. e., efficient voltage gate drive requirements and high current density capability. The interaction of the IGBT with the load circuit can be described using the device model and the state equation of the load circuit. The protection circuit requirements are unique for the IGBT and can be examined using the model.

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Ir-192 방사성소선원에 의한 뇌종양의 치료계획 (Ir-192 Brachytherapy Planning of Brain Tumor)

  • 최태진;박정호;김옥배;서수지
    • Radiation Oncology Journal
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    • 제6권2호
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    • pp.277-281
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    • 1988
  • Although widely used in external beam treatment planning, computed tomography scans are infrequent in incranial tumors by implanting of Radioactive isotope. This incranial brachytherapy has only become possible by using CT scans and stereotaxic operation methods. The coincidence of single source and tumor axes in brachytherapy is very important to determine the therapeutic dosages. Eventhough using the CT scan, according to spatial location of tumor tying, the section of tumor will be seen enlargement, cause the tumor will be cut off with slight angle to its axes. Correct analysis of tumor size from source is required for rotated axes in analytical geometry.

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FCVA 방법으로 증착된 다이아몬드상 탄소 박막의 XPS 및 XRR 특성 연구 (A Study on XPS and XRR Characteristics of DLC films Deposited by FCVA Method)

  • 박창균;장석모;엄현석;서수형;박진석
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권3호
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    • pp.109-115
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    • 2003
  • Diamond-like carbon (DLC) films are deposited at room temperature using a filtered cathodic vacuum arc (FCVA) technique. The influence of negative bias voltage (applied to the substrate from 0 to -250V) on the $sp^3$ hybridized carbon fraction is examined by Raman spectroscopy and x-ray photoelectron spectroscopy (XPS) for C 1s core peak. For the first time, depth profile of C 1s, Si 2p, and O 1s XPS peaks for the deposited DLC film are obtained. DLC film is modeled as a multilayered structure. composing of surface, bulk, and interface. In addition, the x-ray reflectivity (XRR) is proposed as a method for estimating the density, surface roughness, and thickness of each layer constituting the DLC film. The estimated thickness of DLC film is in good agreement with the result obtained from the transmission electron microscope (TEM) measurement.

웹 환경 요소를 고려한 전자상거래 사이트 평가 기법 (The evaluation techniques of electronic commerce website considering web environment elements)

  • 서수석;이종호
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2002년도 추계학술발표논문집 (하)
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    • pp.2195-2198
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    • 2002
  • 전 세계적으로 전자상거래의 수요가 폭발적으로 증가하고 있고, 많은 개인과 기업들이 전자상거래 사이트를 구축하여 운영하고 있지만 이를 사업적인 측면에서 수익과 연결시키지 못하고 있으며, 소비자에게 편리한 구매를 지원하지 못하는 등 많은 문제점이 야기되었다. 따라서 본 논문에서는 전자상거래 사이트의 합리적인 평가 모델을 제시함으로써 전자상거래 웹사이트의 구축과 운영상의 기초 자료를 제공하고, 효율적 관리 및 활용 촉진을 도모하고자 한다. 따라서 현재 전자상거래 웹사이트의 실태를 점검 평가함으로써 궁극적으로 서비스 향상 그리고 개인과 기업 또는 조직의 생산성 향상 및 이윤 극대화 방안을 모색할 수 있을 것이다. 본 논문에서는 웹사이트의 성격에 따라 평가하는 기준과 가중치 또한 다르다는 인식 하에 선행연구와 여러 기관들의 평가기준을 고찰한 후, 평가변수의 체계적인 분석을 통해 전자상거래 웹사이트의 새로운 측정의 틀을 설계하고 이에 따른 평가 모델을 구축 제시하였다. 본 평가 모델을 통한 전자상거래 웹사이트의 평가는 운영자의 입장에서는 웹사이트의 효율적인 운영과 예산에도 많은 영향을 미칠 것이고, 이는 사용자 측면에서도 더욱 유리한 방향의 효과가 나타날 것이다.

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라이다 자료로부터 라스터 형태에 기반한 형상 추출기법 연구 (Feature Extraction from Rasterized Forms of Lidar Data)

  • 서수영;김해명
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2008년도 공동추계학술대회
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    • pp.144-145
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    • 2008
  • 본 연구는 라이다 자료를 이용하여 건물영역을 추출하고 건물모델을 구성하는 선형과 면요소들을 추출하는 기법을 제시하였다. 라이다 자료는 지형지물의 표고값을 정확하고 직접적인 방식으로 제공함으로써 기존의 항공사진에 비하여 매칭과정을 필요로 하지 않는 장점을 가지고 있다. 하지만 라이다 점들은 해당 수평위치에 대한 표고값만을 제공하기 때문에 지표 위의 지형지물들을 추출하기 위해서는 먼저 점들간의 기하학적인 관계를 분석하여 그들을 구성하는 선이나 면요소들을 추출해야 한다. 이를 위하여 본 연구에서는 먼저 라이다 자료를 라스터 형태로 변환한 후, 이미지 프로세싱을 통하여 상대적으로 낫은 영역과 높은 영역으로 분리하여 각각 지형과 건물영역으로 분류하였다. 다음으로 건물영역 경계로부터 건물 외곽선을 추출하고 건물영역 내에 면요소들을 통계분석을 통하여 추출하였다. 실험결과를 통하여 제시한 기법들은 비교적 복잡한 형태의 건물 지붕면과 외곽선을 성공적으로 분할하고 추출할 수 있음을 보여준다.

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Flavonoids의 약리작용(II) -항염작용과 창상치유 억제작용과의 상관성- (Pharmacological Activities of Flavonoids(II) -Relationships of Anti-inflammatory and Antigranulomatous Actions-)

  • 김창종;서수경;주재현;조승길
    • 약학회지
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    • 제34권6호
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    • pp.407-414
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    • 1990
  • The relationships of inhibitory activities of inflammation and wound healing of flavonoids were studied in vitro and in vivo. Generally flavonoids have not only significantly anti-inflammatory activity in carrageenin-induced paw edema and Freund's complete adjuvant-induced arthritis, but also inhibitory activity of wound healing. The more inhibitory activities of wound healing flavonoids have, the more they have the anti-inflammatory activities; apigenin > guercetin > flovone > rutin > hesperidin > naringin. Their inhibitory mechanism seems to be inhibition of the inflammatory cell infiltration and fibroblast proliferation, and so they decreased the granulomatous activity and tensile strength.

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Bi-2223초전도 선재의 접합공정 연구 (A study of joining method of BSCCO(2223) tape)

  • 김정호;김태우;주진호;서수정
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 1999년도 제1회 학술대회논문집(KIASC 1st conference 99)
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    • pp.18-21
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    • 1999
  • The effects of joining process such as contact method, shape of joined area and pressure on the properties of Bi-2223 superconducting tape have been optimized. In the process tapes were etched to expose the superconductor core in the shape of 'ㅁ' and 'ㄷ'. The exposed cores of the two tapes were brought into contact, uniaxially pressed and sintered. Subsequently, the current capacity of the joined tape was measured as a function of uniaxial pressure. It was observed that the current capacity was significantly dependent on uniaxial pressure. The joined tape, fabricated with a pressure of 1,600 MPa, showed the highest value of current capacity(90%) of highest value of current capacity is resulted from improvements in core density, contacting area and grain alignment, etc. In addition the effect of processing variables on microstructural evolution and mechanical property of joined tape will be presented.

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축력과 휨을 받는 스터드볼트 접합부의 거동에 관한 실험적 연구 (Behavior of Stud Connection Subjected to both Constant Axial and Various Bending Moments)

  • 김승훈;이태석;서수연;이리형;홍원기;백승대
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.535-540
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    • 2000
  • When the stud connection is considered as pin joint in the practical design, it is required to have high deformability. The rotational capacity as well as moment of the connection are evaluated through experimental works. Considered in the test are the reinforcement ratios of concrete member, the magnitude of axial force and connection details. It is shown that the stud connection has some quantity of moment capacity buy on the other hand it has low deformability. The strength and deformability of the connection depend on the axial force and reinforcements around the studs. The strength and ductility of the connection ate increased by using closed C-type.

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전단스팬비 영향을 고려한 RC구속조적조 벽체의 내진성능평가 (Seismic Performance Evaluation of Confined Masonry Wall System Considering of Shear-Depth Ratio)

  • 김경태;서수연;윤승조;성기태
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.1-4
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    • 2005
  • To investigate the effective seismic strengthening methods for masonry walls in developing countries, a total of four confined masonry (CM) walls were constructed and tested. In order to investigate the effect of the height of application point of lateral loads and reinforcing steel bars in walls and columns for the improvement of the seismic behavior of confined concrete block masonry walls, an experimental research program is conducted. The heights of inflection point considered were 0.67 and 1.11 times the height of the wall measured from the top of foundation beam. The constant vertical axial stress applied was 0 MPa. During the test, cracking patterns, load-deflection data, and strains in reinforcement and walls in critical locations was measured. From test data, it was showed that the seismic performance of confined concrete block masonry walls was significantly affected by test variables.

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