• 제목/요약/키워드: over current characteristics

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유동대전 억제제가 첨가된 변압기유의 전기전도 특성 (The Electrical Conduction Characteristics of Transformer Oils added the Anti-static Agent for Streaming Electrification)

  • 이용우;이태훈;오세영;이종필;차광훈;홍진웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1213-1215
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    • 1997
  • In order to investigate the electrical characteristics due to the BTA(Benzotriazole) additive in the transformer, the electrical characteristics of the transformer oils contained benzotriazole as an anti-static agent for streaming electrification is studied by measuring the electric conduction. As a result of the electrical conduction characteristics, it is confirmed that the conduction current of virgin specimen is more higher than that of specimen contained the BT A 10[ppm] over 35[$^{\circ}C$], but that of specimen contained the BT A 10[ppm] over 50[$^{\circ}C$] is increased.

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The Conduction Characteristics in Oriented Polypropylene Films

  • Oh, Jae-Han;Jung, Il-Hyun;Kim, Sang-Keol;Park, Geon-Ho;Lee, Kyung-Sup
    • Transactions on Electrical and Electronic Materials
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    • 제1권1호
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    • pp.45-52
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    • 2000
  • The conduction characteristics in Oriented polypropylene (OPP) film were studied over electric field intensities between 10 M/V m and 300 M/V m . The range of the conduction characteristics was divided in to five regions with increasing field intensity. Particularly, in the region from 70 Mb/m to 82 MV/m voltage-controlled negative resistance was displayed. In the negative resistance region current oscillations were also observed the negative resistance characteristics could by explaine by Gibbons theory.

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한국형 고속열차의 350km/h 본선 주행시험을 통해 본 고속열차용 팬터그래프의 이선 특성과 동적 특성 고찰 (Study on the current collection & vibration characteristics of the KHST's pantograph through trial running test up to 350km/h)

  • 목진용;박찬경;박춘수;김기환
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.459-462
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    • 2005
  • The KHST(Korean High Speed Train) which had been developed by through 'G7-R&D project' has succeeded trial running test up to 350km/h on the Kyoung-Bu High Speed Track in December 16th, 2004. In order to evaluate the function and characteristics of KHST, various experimental conditions have been considered and conducted. In this paper, measured current collection characteristics and dynamic behaviors of KHST's pantograph are analysed over 300 to 350km/h in running speed of KHST. A measuring system developed and installed on the KHST for measuring the performance and mechanical characteristics of the KHST's pantograph was used for this trial running test and eventually, we proofed that KHST has a remarkable and stable current collection characteristics as it had been designed.

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Preparation of ITO Thin Films for Display Application with $O_2$ Gas Flow Ratio and Input Current by FTS (Facing Targets Sputtering) System

  • Kim, H.W.;Keum, M.J.;Lee, K.S.;Kim, H.K.;Kim, K.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1477-1479
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    • 2005
  • In this work, the ITO thin films were prepared by FTS (Facing Targets Sputtering) system under different sputtering conditions which were varying $O_2$ gas flow, input current at room temperature. As a function of sputtering conditions, electrical and optical properties of prepared ITO thin films were measured. The electrical, optical characteristics and surface roughness of prepared ITO thin films were measured. In the results, as increasing $O_2$ gas 0.1[sccm] to 0.7[sccm], resistivity of ITO thin film was increased with a decreasing carrier concentration, $O_2$ gas over 0.3[sccm] the carrier mobility have a similarly value. Transmittance of prepared ITO thin films were improved at increasing $O_2$ gas 0.1[sccm] to 0.7[sccm]. And transmittance of all of the prepared ITO thin films was over 80%. We could obtain resistivity $6.19{\times}10^{-4}[{\omega}{\cdot}cm]$, carrier mobility $22.9[cm^2/V{\cdot}sec]$, carrier concentration $4.41{\times}10^{20}[cm^{-3}]$ and transmittance over 80% of ITO thin film prepared at working pressure 1mTorr, input current 0.4A without any substrate heating.

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배전선로에 사용되는 전자개폐기(Magnetic Switch)의 가속수명시험에 관한 연구 (A Study on Accelerated Life Tests for Magnetic Switch Used in Distribution System)

  • 유행수;한규환;권영일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.536-540
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    • 2002
  • In this paper, accelerated life test (ALT) models and procedures for Magnetic Switch (MS) are developed and applied to assure specified reliability of the products at development phase and guarantee the life of the products. Magnetic contactor that functions with over-current relay is called MS. Magnetic contactor closes and opens the motor load with ON/OFF switch of electronic contactor. It is also used for protecting and controlling the load. Magnetic contactor detects the over-current flow in the load with a over-current relay and disconnects the load by opening its control power. In this study, ALT models for MS are developed using the relationship between stresses and life characteristics of products. Using the ALT models, we performed life tests and analyzed the tests results. The proposed ALT models and procedures may be extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably. Finally the results of this study will contribute to improving reliability of products and strengthening competitiveness of our products in world markets.

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광안해역에서의 파랑변형예측 (Prediction Wave Transformation in the Kwangan Beach)

  • 박정철;김재중;이정만
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 춘계학술대회논문집
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    • pp.75-81
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    • 2000
  • Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develop as wave-current equation type to investigate the effect of wave-current interaction. This wave-current model was applied to the Kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

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온도변화에 따른 AlGaAs/GaAs HBT의 전류이득 특성 (Current Gain Characteristics of AlGaAs/GaAs HBTs with different Temperatures)

  • 김종규;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.840-843
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    • 2001
  • In this study, temperature dependency of current gain for AlGaAs/GaAs/GaAs HBT is analytically proposed over the temperature range between 300K and 600K. Energy bandgap, effective mass, intrinsic carrier concentration are considered as temperature dependent parameters. Collector current which is numerically calculated is then analytically expressed to enhance the speed of calculation for current gain. From the results, current gain decreases as the temperature increases. These results will be used to expect the unity current gain frequency f$_{T}$ in conjunction with emitter-base and collector- base capacitances.s.

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전류모드 CMOS에 의한 3치 가산기 및 승산기의 구현 (Implementation of Ternary Adder and Multiplier Using Current-Mode CMOS)

  • 성현경
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.142-144
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    • 2006
  • In this paper, the Ternary adder and multiplier are implemented by current-mode CMOS. First, we implement the ternary T-gate using current-mode CMOS which have an effective availability of integrated circuit design. Second, we implement the circuits to be realized 2-variable ternary addition table and multiplication table over finite fields GF(3) with the ternary T-gates. Finally, these operation circuits are simulated by Spice under $1.5{\mu}m$ CMOS standard technology, $1.5{\mu}m$ unit current, and 3.3V VDD voltage. The simulation results have shown the satisfying current characteristics. The ternary adder and multiplier implemented by current-mode CMOS are simple and regular for wire routing and possess the property of modularity with cell array.

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파랑에 의한 연안류의 수치모델에 관한 연구 (A Study on the Numerical Models of Wave induced Currents)

  • 이정만;김재중;박정철
    • 한국해양공학회지
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    • 제12권3호통권29호
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    • pp.75-85
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    • 1998
  • A finite difference model for predicting time-dependent, wave-induced nearshore current is studied. The model includes wave refraction, wave-current interaction, bottom friction and wind effect. This model iteratively solved the linear the linear set of conservation of both mass and momentum, which were time averaged (over one wave period) and depth integrated, for mean velocities and free surface displacement. Numerical simulations of nearshore current under oblique wave attack, and for wave and wind induced current on a longshore periodic beach are carried out. Longshore velocities tend to zero in some distances outside the breaker line. And the peak velocity is shifted shoreward at the breaker line. The results represent the general characteristics of the nearshore current induced by wave.

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광안해역에서의 파랑변형예측 (Prediction of Wave Transformation in the Kwangan Beach)

  • 박정철;김재중;김인철
    • 한국해양공학회지
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    • 제15권2호
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    • pp.6-10
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    • 2001
  • Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develope as wave-current equation type to investigate the effect of wave-current interaction. It starts from Berkhoff's(1972) mild slope equation and is transformed to time-dependent hyperbolic type equation by using variational principal. Finally the governing equation is shown as a parabolic type equation by splitting method. This wave-current model was applied to the kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

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