• Title/Summary/Keyword: energy gap

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The Band Structure of GaAs/(Al,Ga)As Superlattice with Interface Grading (계면경사가 있는 GaAs/(Al, Ga)As 초격자의 밴드구조)

  • 김장래;김충원;한백형
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.3
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    • pp.287-293
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    • 1988
  • This paper calculates the band structure of the GaAs/(Al,Ga) As semiconductor superlttice with the interface3 grading, in consideration of different effective masses in each region. Including the effective masses, superlattice period, well and barrier widths, and the interface, the dispersion relation is derived, and the effects that the above parameters affect the subband (or miniband) structure of the superlattice and effective energy gap are investigated. It is particularly found that this case(ma<>mb<>mc) is significantly different from the same effective mass case(ma<>mb<>mc).

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New Structure to Enhance the Light Efficiency in LCoS Optical Engine

  • Huang, Chi-Wei;Mo, Chi-Neng;Wu, Shih-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.744-747
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    • 2005
  • The exploitable efficiency of UHP is very important in a projection system. We always use lens array for light shaping and energy distribution transformation in conventional projection system. Because of the limitation of arc gap and F/# of elements, the utilize efficiency is always dismal. In this paper we try to bring out a new method to reduce the sparkle formed on the PS converter and enhance the system efficiency.

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Electroless Deposition of ITO Thin Films (무전해침전법에 의한 투명전도박막 제작에 관한 연구)

  • ;邊潤植;李建基
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.2
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    • pp.238-241
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    • 1987
  • ITO thin film was prepared by the electroless deposition technique. ITO thin film had a high transmittance in the visible region and a high reflectance in the near infrared region. The energy gap of the thn film (Sn/Im=0.1) was 4.05 eV, the carrier concentration was 2x10**21 cm**-3, and the electric resistivity was 1.5x10**-3 ohm-cm. We confirmed that ITO thin film was a degenerated n-type semiconductor.

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Nuclear Magnetic Relaxation in Flurinated $YBa_2Cu_3O_{7-x}$

  • Lee, Cheol-Eui;White, D.;Davies, P.K.;Moon, B.M.;Sung, M.Y.;Park, J.H.;Kim, B.H.
    • Journal of Magnetics
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    • v.1 no.1
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    • pp.1-3
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    • 1996
  • The $YBa_2Cu_3O_{7-x}$ structure has been fluorinated by a gas phase exchange technique. The ${^19}F$NMR (nuclear magnetic resonance) spin-lattice relaxation rate (1/T1) measurements on a fluorinated sample gave superconducting energy gap of $2\Delta=4.6kT_c$.

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Diffraction-Induced Wave Setup inside Harbor

  • Oh, Tae-Myoung
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.130-133
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    • 1998
  • This paper identifies diffraction-induced wave setup when waves enter into a harbor of constant depth through a breakwater gap narrower than one wave length. It is well known, for this case, that the waves in the lee of the breakwater propagate as if from a point source and the wave crest lines are approximated well by semicircular arcs. Wave height decreases in accordance with conservation of energy; thereby resulting in an appreciable setup of the surface. (omitted)

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The Analysts of PerformaneeCharacterlstics of a L.I.M. with taken into Conslderatlon of End Effects(l) (단부효과를 고려한 L.I.M.의 동작특성 해석 (1))

  • 임달호;이은웅;장석명
    • 전기의세계
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    • v.31 no.4
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    • pp.288-295
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    • 1982
  • In this study, the characteristic equation of a double sided short stator linear induction motor, referred to as LIM excited by equivalent current sheet having linear current density was derived using Maxwell's electromagnetic field theory with its entry and exit, end effects taken into consideration. According to the treatment of several physical phenomena in the air-gap i.e. the magnetic flux density distributions, thrust-force, forward and backward travelling wave with decay, normal field, the fundamental data in this study are made reference to improve the characteristics of LIM, effectual electro-magnetic energy conversion devices.

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Adsorption of carbon atoms on graphene/MgO(111)

  • Min, Kyung-Ah
    • Proceeding of EDISON Challenge
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    • 2013.04a
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    • pp.228-231
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    • 2013
  • In this study, we investigate the electronic and atomic structure of graphene on O-terminated MgO(111) using density functional theory (DFT) calculations. To suggest a possible direction for future band gap engineering of graphene on MgO(111), adsorption of carbon atoms on graphene/MgO(111) is studied by considering the several adsorption sites. Details in adsorption properties of carbon atoms on graphene/MgO(111) are analyzed in terms of energy band structure.

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Embodiment of all-optical switching phenomena on a GaAs waveguide

  • Lee, Sang-Jae
    • Journal of Sensor Science and Technology
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    • v.5 no.5
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    • pp.85-95
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    • 1996
  • Based on the transmission of coupled gap solitons in nonlinear periodic media, we present an all-optical switching scheme which has a novel architecture and principle. The proposed switch with an extremely small switching element can be realized on a semiconductor waveguide. We here investigate the switching performance with a GaAs waveguide in order to give criteria for the experimental realization of the all-optical switching phenomena. We also suggest a variation of an index-matching scheme to solve the technical problem such as the input-energy coupling into a periodic waveguide.

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Battery energy storage system for 10kW wind turbine output stabilization (배터리 에너지 저장장치를 이용한 10kW 풍력발전출력 안정화 시스템 개발)

  • Oh, Seung-Jin;Han, Byung-Moon
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.36-37
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    • 2010
  • This paper presents a simulation model and results of experiment about analysis of grid-tied wind turbine generator with batteries. The system consists of two inverters and a bidirectional DC/DC converter. These inverters are to capture the maximum active power under varying wind conditions and to keep the DC-link voltage magnitude at a specific level. And the bidirectional DC/DC converter makes battery charging or discharging depend on power gap between wind turbine output and local load.

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