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검색결과 3,913건 처리시간 0.036초

Linear Temperature Dependence of Magnetic Penetration Depth Length at Low T in an Isotropic Superconductor

  • Nam, Sang-Boo
    • Progress in Superconductivity
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    • 제2권1호
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    • pp.11-14
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    • 2000
  • The notion of the finite pairing interaction energy range Td is shown to result in a linear temperature dependence of the London magnetic penetration depth length, ${\Delta}{\lambda}{/\lambda}(0)=(T/Td)2/\pi)ln2$ at low T in the case of the s-wave pairing state, accounting for data of high Tc superconductor by Hardy et al.

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유치원 교사의 과학교수효능감에 영향을 미치는 관련 변인 연구 (Self-Efficacy Beliefs of Kindergarten Science Teachers)

  • 조부경;서소영
    • 아동학회지
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    • 제22권2호
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    • pp.361-373
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    • 2001
  • This study identified significant variables that influence the science teaching self-efficacy beliefs of Kindergarten teachers. Data was obtained from 317 kindergarten teachers who responded to the questionnaire, the Science Teaching Efficacy Belief Instrument (Riggs & Enochs). Results indicated that science teaching experience, teachers' attitudes about science and teaching science, and children's interest in science influenced science teaching self-efficacy. Science related experiences of childhood and schooling negatively affected science teaching outcome expectancy.

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큐 상태 정보와 예측을 기반으로 한 흐름제어기법 (A Flow Control based on Queue Dynamics and Estimate Information)

  • 서주하;정부영;유현희
    • 산업기술연구
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    • 제19권
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    • pp.423-428
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    • 1999
  • In this paper, We propose a new flow control scheme based on Queue Dynamics and it's Estimate Information in order to achieve higher throughput and network efficiency using control of the best-effort traffic. The feedback Information gives a result that compare queue length with queue threshold. Traffic changes at the time when queue length is cross over under the queue thresholds. The performance of the purposed scheme has been analyzed mathematically and we verify efficiency of the proposed method by means of simulation.

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레이저 다이오드의 코팅된 단면의 반사율 측정에 사용되는 문턱전류비에 관한 연구 (A study on the threshold current ratio method using the measurement of coated facet reflectivity of a laser diode)

  • 이상무;김부균
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.541-543
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    • 1995
  • We propose the improved threshold current ratio method to determine the reflectivity of coated facets. The carrier recombination time used in the improved threshold current ratio method depends on the value of facet reflectivities. However, the carrier recombination time used in the conventional threshold current ratio method is constant regardless of facet reflectivities. The difference between the results of the two methods increases as the reflectivity of a coated facet decreases.

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$N_2$ 가스에서 전자의 수송현상에 대한 입자적 해석 (The particle analysis on electron transport coeffcient at $N_2$ gas atmosphere)

  • 이용신;심재학;고광철;강형부
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1932-1934
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    • 1996
  • Electron transport coefficients are calculated in nitrogen over the E/p range $50{\sim}700\;V\;cm^{-1}$ $Torr^{-1}$ by a Monte Carlo method, using a set of electron collision cross sections measured by authors.

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미생물이 생산하는 항산화물질에 관한 연구 (Studies on Antioxidants of Microbial Origin)

  • Park, Boo-kil
    • 한국미생물·생명공학회지
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    • 제11권3호
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    • pp.201-204
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    • 1983
  • Antioxidant, tentatively named PA-29B substance was isolated from the fermentation broth of rare Actinomycetes. It was isolated by means of silica gel column chromatography and obtained as colorless plates, mp 155-157$^{\circ}C$. The structure of PA-29B substance was assigned to be $\alpha$-phenyl acetamide by $^1$HNMR spectrometer and mass spectrometer.

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수중무기 체계의 정비 시간 예측 (On the Maintenance Time Prediction of an Underwater Military System)

  • 신주환;김상부;윤원영
    • 산업공학
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    • 제11권1호
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    • pp.175-182
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    • 1998
  • The maintainability prediction of an underwater military system is considered. A general and parctical prediction method for maintainability using MIL-HDBK-472 is presented. We develop a computer program to predict MTTR of an underwater military system. A case study is made to explain the proposed maintainability prediction method.

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