• 제목/요약/키워드: semi-conductor

검색결과 240건 처리시간 0.026초

고온초전도 직류 케이블용 절연재료인 PPLP의 직류 및 임펄스 절연 특성 (DC and Impulse Insulation Characteristics of PPLP for HTS DC Cable)

  • 김우진;방만식;김해종;조전욱;김상현
    • 한국전기전자재료학회논문지
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    • 제26권7호
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    • pp.545-549
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    • 2013
  • To realize the high-Tc superconducting (HTS) DC cable system, it is important to study not only high current capacity and low loss of conductor but also optimum electrical insulation at cryogenic temperature. A model HTS DC cable system consists of a HTS conductor, semi-conductor, cooling system and insulating materials. Polypropylene laminated paper (PPLP) has been widely adopted as insulating material for HTS machines. However, the fundamental insulation characteristics of PPLP for the development of HTS DC cable have not been revealed satisfactorily until now. In this paper, we will discuss mainly on the breakdown characteristics of 3 sheets PPLP in liquid nitrogen ($LN_2$). The characteristics of the diameter, location of butt-gap, distance between butt-gap length, pressure effect, polarity effect under DC and impulse voltage were studied. Also, the DC polarity reversal breakdown voltage of mini-model cable was measured in $LN_2$ under 0.4 MPa.

Epoxy-Cu간 접촉면에서의 절연특성 개선 (Reformation of Dielectric Property in interface between epoxy and Cu)

  • 송재주;김성홍;정남성;황종선;한병성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.9-12
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    • 2000
  • Insulators for high-voltage and large-power should be endured mechanically the weight of mold bushing itself and the force of pushed from contact with circuit breaker and conductor. But dielectric breakdown could be occurred result from the external circumstances and internal factors such as chemical reaction, partial discharge, change of temperature and the relation of temperature-time in process of casting. Therefore, to get rid of external and internal factors of dielectric breakdown. Furthermore, to prevent the internal cracks, void, cavity which resulted from the contraction originated on the interface between copper and epoxy resin, formed semi-conductive layer with partially carbon painted on copper bar. The PD properties and the insulation qualities of epoxy molded insulators were improved by roles of cushions for the direction of diameter and natural sliding effects as like separated from conductor for the direction of length.

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기계설계분야 중견 엔지니어의 일과 학습에 관한 내러티브 연구 - 엔지니어의 직무관련 학습의 맥락과 공학교육에 대한 시사점 찾기 (A narrative research on the job and the job-related learning of a mechanical engineer - an exemplary study on the characteristic of job-related learning of engineer in work place and it's implication on engineering education)

  • 임세영
    • 대한공업교육학회지
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    • 제38권2호
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    • pp.1-26
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    • 2013
  • 이 연구는 기계설계 분야의 중견엔지니어 한 사람을 중심으로 그가 수행하는 구체적인 과업은 무엇이며 그와 관련하여 이루어지는 학습은 무엇인지, 일터에서 이루어지는 직무관련 학습의 맥락은 무엇인지 내러티브 연구방법에 의해 탐구하였으며, 이것이 공학교육에 주는 시사점을 논의하였다. 연구결과 연구참여자는 취업 후 수입대체를 위한 초창기 반도체 검사장비 개발을 위해 독립적으로 개발할 장비에 관한 기초지식을 습득하고 장비의 개념설계를 하였으며, 볼 타입 반도체 검사장비개발 동료들과 함께 장비의 구체설계를 하였고, 근무하던 회사의 폐업 후 잔류 엔지니어들과 함께 창업, 인터뷰 당시 이 기업의 경영자로 일하였다. 그가 엔지니어로서 수행한 주요 실무는 공학적 문제해결이었으며, 비형식적 학습의 과정이었다. 그는 실무수행 과정에서 프로젝트 관리, 자기주도적 과업수행, 기능분석, 추론과 검증, 긴밀한 협동, 대화와 토론, 시행착오, 암묵적 경험지식의 체계화, 총체적 사고, 환경변화의 지각과 기술수요 예측, 인간관계와 업무의 조화, 리더십 등을 경험하였다. 이를 바탕으로 공학교육이 프로젝트 학습, 자기주도적 학습, 대화와 토론 능력 교육을 위한 협동학습, 성찰학습, 실무적 경험을 이론화하는 학습, 인간관계와 리더십 교육 등을 강화해야 한다는 시사점을 얻었다.

PSIM 소프트웨어에 의한 STATCOM 시스템 시뮬레이션 (STATCOM System Simulation Used by the PSIM Software)

  • 이화수;김용헌;이은웅;이동주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.94-96
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    • 2003
  • The study for improvement of power qualify is widely performed, because most equipments used semi-conductor are very sensitive for power quality. In this paper, we performed modeling for STATCOM system which developed using SCRs, and suggested the compensation principle of reactive Power by simulations used PSIM software. We will apply this results to 30kVA STATCOM under manufacturing.

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The Band Edge Liminescence of SUrface Modified CdSe Nanocrystallites and Their Applications

  • Lee, Jin-Kyu;Kuno, Masaru K.;Bawendi, Moungi G.
    • Journal of Photoscience
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    • 제5권4호
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    • pp.175-179
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    • 1998
  • In this paper, a brief overview of nanocrystallites of metal and semi-conductor materials will be presented, and then the novel synthetic method of high quality CdSe nanocrystallites developed by Bawendi group at MIT will be introduced . It will be shown that results of optical properties of surface modified nanocrystallites give the evidence that the luminescence of CdSe nanocrystallites is not originated from surface related trap states, but from intrinsic spin forbidden core states. Some of the interesting applications of CdSe nano-crystallites will also be discussed at the end.

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초정밀 다축 위치제어장치 개발 및 보정에 관한 연구 (A Study on the Development and Compensation of precision Multi-Axis Positioning System)

  • 정상화;차경래
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.455-458
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    • 2002
  • In recent years, precision positioning stage is demanded fur some industrial fields such as semi conductor lithography, ultra precision machining and fabricating of nano structure. In this research, precision multi-axis positioning stage, which consists of pzt actuator, flexure, and capacitance gauge, is designed and developed. The performance of it such as 3-axis positioning, characteristic of motion and resolution is verified.

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나노위치제어용 선형 모터의 거동 분석

  • 설진수;이우영;임경화
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2005년도 춘계 학술대회
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    • pp.125-128
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    • 2005
  • The equipments in semi-conductor, display and measurement fields require high precision and resolution positioning technology. High positioning control can be carried out by using linear motors with little vibration, backlash and friction. In this paper, the acceleration patterns of the moving Part are analyzed to obtain the optimum pattern which leads to the less vibration reduction of equipment. In addition, the effect of friction force in guide rail on position control accuracy is investigated to identify possibility of using current bearing system for nano-positioning control.

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압전 액츄에이터를 이용한 초정밀 위치제어장치 개발 (Development of Nano Positioning Stage using PZT Actuator)

  • 정상화;차경래
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.214-218
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    • 2002
  • In recent years, precision positioning stage is demanded for some industrial fields such as semi-conductor lithography, ultra precision machining, and fabricating of nano structure. In this research, precision multi-axis positioning stage, which consists of pzt actuator, flexure, and capacitance gauge, is designed and developed. The performance of 3-axis positioning, characteristics of motion and resolution are verified.

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Area Usage Factor Analyzing Method for Semi-conductor Manufacturing Process

  • Konishi, Katunobu;Ukida, Hiroyuki;Sawada, Koutarou
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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    • pp.480-483
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    • 1998
  • For memory products, it is very important to develop a new production line as soon as possible. All products are inspected to get rid of defected products at the last testing stage. Those inspection data are called FCM. In this paper, based on the FCM data, Area Usage Factor (AUF) analyzing method will be proposed. Process engineers can make up their mind to which direction they should concentrate their analyzing power.

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