• 제목/요약/키워드: absorbed power

검색결과 191건 처리시간 0.021초

평판형 유도결합 플라즈마 장치의 $CF_4$ 방전에 대한 Global Simulation (Global Simulation for $CF_4$ Discharge in Transformer Coupled Plasma Source)

  • 권득철;유동훈;김성식;윤남식;김정형;신용현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1757-1759
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    • 2002
  • Global simulator for $CF_4$ discharge in transformer coupled plasma (TCP) source is developed and simulations arc performed under various conditions. The developed simulator is based on a set of space averaged fluid equations for electrons, positive ions, neutrals and radicals of $CF_4$ plasma. And the used absorbed power by electrons is calculated by a 2-dimensional heating model[1].

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발전기 스테이터의 냉각코일에 pinhole 발생을 검지 할 수 있는 수소센서 개발 ($H_2$ sensor for detecting hydrogen in DI water using Pd membrane)

  • 최시영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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    • pp.442-445
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    • 1999
  • In this work, to detect of hydrogen in DI water in the generator area of nuclear power plants was fabricated Pd/Pt gate MISFET sensor using Pd membrane. $H_2$ permeation through Pd accounts for external mass transfer, surface adsorption and desorption, transitions to and from the bulk metal, and diffusion within the metal. The identification of pinholes in the generator area of plant is an important safety consideration, as hydrogen build-up gives rise to explosion. For this type of application the sensor needs to be isolated in DI water, accordingly, a Pd membrane was used to separate the DI water. The hydrogen in the DI water was then absorbed on the Pd thin film and diffused into the oil through the thin film. The Pd/Pt gate MISFET sensor, encapsulated by oil, will thereby detect permeated hydrogen.

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The Comparison with SAR Patterns of Biological Objects Contacted with Coaxial Waveguide Antenna Using the FDTD Method

  • Koo, S.M.;Kwon, K.H.;Lee, C.W.;Won, C.H.;Kim, M.N.;Cho, J.H.
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.272-275
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    • 1997
  • Noninvasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and our layer human body model. We derived finite-difference time-domain(FDTD) algorithm and equation of MUR and generalized perfectly matched layer(GPML) absorbing boundary conditions(ABCs) in cylindrical coordination. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of the FDTD method using MUR and GPML ABCs to obtain the absorbed power patterns in the media. The specific absorption rates(SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in FDTD method. The SAR patterns of FDTD method using MUR ABCs was compared with those of FDTD method using GPML ABCs.

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다중경로 페이딩 채널에서 DAC 양자화 오차에 대한 IEEE P802.15.3a 멀티밴드 UWB 송수신기 성능 분석 (Performance Analysis of IEEE P802.15.3a Multi-band UWB Transceiver for DAC Quantization Error in Fading Channel)

  • 정성원;이승윤;임승호;박규호
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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    • pp.216-219
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    • 2003
  • In this paper, we present performance analysis of an IEEE P802.15.3a high rate wireless personal area network transceiver. This physical layer standard uses QOSK as its sub-channel modulation scheme and orthogonal frequency domain modulation (OFDM) for sub-bands. OFDM is used for each sub-band so that multi-path effects are absorbed by equalizer and guard, and fading can be approximately modeled as additive white Gaussian noise. In multi-band ultra-wideband system, DAC quantization error is important noise source since high resolution conversion cannot be used due to high power consumption. Simulation result shows that, to get 640-Mbps throughput, at least 5-bits precision is necessary to maintain bit-error rate under 10$\^$-2/, which can be lowered, with channel coding, to 10$\^$-6/ that is the bit-error rate required by IEEE 802.15 upper protocol layer, in 4-meter LOS fading channel.

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초고압 OF 케이블 급유계통의 조기이상검지시스템 (New leakage detection system for the hydraulic system of EHV underground oil-filled cables)

  • 김영;성정규;한창석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1966-1968
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    • 2000
  • Globally, oil-filled paper-insulated cables and cross-linked polyethylene-insulated cables have been mainly applied for a underground power transmission line. The oil-filled cable has the hydraulic system in which insulating oil, expanded and contracted by temperature changes, is absorbed and supplied. This system enable us to detect oil leakages from the cable. But it has some problems such as difficulty in detecting minor leakages and a relatively long period of fault detecting. And so, this paper introduce a new leakage detection system, improved from the current one.

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전계흡수형 도파로에서 광전류를 이용한 전계에 따른 흡수변화의 측정 (Measurement of field-induced absorption changes in an electroabsorption waveguide using photocurrent)

  • 강병권;박승한;최중길
    • 한국광학회지
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    • 제10권3호
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    • pp.254-258
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    • 1999
  • 전계흡수형 반도체 광도파로에서 흡수된 빛에 의해 발생된 광전류는 전파되는 파장에 따라 Fabry-Perot 모드의 간섭패턴을 나타냄을 보이고, 이로부터 인가전압에 따른 흡수계수의 변화를 측정할 수 있는 방법을 제시하였다. 광전류 신호는 파장에 따라 공명 반공명을 반복해서 나타내며 그 진폭은 흡수계수의 크기에 의존하므로 전계에 따른 흡수계수의 변화량을 측정 할 수 있었고, 1.55 $\mu\textrm{m}$ 파장에서 역전압 1.5V 인가시 bulk in GaAsP의 흡수계수 변화는 대략 157cm-1임을 알 수 있었다.

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유한 차분법을 이용한 동축 도파관 안테나에 접촉된 생체의 SAR 패턴에 관한 연구 (SAR Pattern of Biological Objects Contacted with Coaxial Waveguide Antenna Using the FDTD Method)

  • 구성모;이창원;원철호;조진호
    • 대한의용생체공학회:의공학회지
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    • 제18권3호
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    • pp.261-266
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    • 1997
  • Nonevasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and four layer human body model. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of the finite-difference time-domain(FDTD) method to obtain the absorbed power patterns in the media. The object studied in this paper was a homogeneous and four-layered lossy medium. The specific absorption rates(SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in FDTD method. The SAR pattern of 1.2GHz was compared with that of 1.8GHz.

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슈퍼커패시터를 이용한 전기차량용 회생제동 에너지 저장장치 개발 (Development of Regenerative Energy Storage System for An Electric Vehicle Using Super-Capacitors)

  • 정대원
    • 전기학회논문지
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    • 제60권3호
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    • pp.544-551
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    • 2011
  • This paper presents the circuit arrangement and effective control method of regenerative energy storage system for an electric vehicle using super-capacitors as the braking energy storage element. A bi-directional controlled current flow of the DC-DC converters with the capacitor bank is connected in parallel with battery, and is controlled so that the whole of the braking energy is effectively absorbed into the capacitors and released back to the electric motor upon acceleration. The converter needs the series-parallel switching circuit for making the best use of the series capacitors and for limiting the step-up ratio of the boost converter. The proposed methods are verified by computer simulation and experimental set-up. They are usefully applied to the electric vehicles such as green cars, electric motorcycles, bike, etc which are power- supplied by the electric batteries.

A 전기적인 대구조의 마이크로파 가열의 수치해석 모델링 (A Numerical Algorithm for Modeling Microwave Heating Effects in Electrically Large Structures)

  • ;이하영;김형석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.2315-2317
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    • 2005
  • In this paper, an iterative method to model the electromagnetic heating of electrically large lossy dielectrics is presented. Frequency domain finite element (FEM) solutions of the wave equation are determined for the lossy inhomogeneous dielectric as the material properties are change with temperature and time. The power absorbed from microwave losses is applied to a finite element time domain (FETD) calculation of the heat diffusion equation. Time steps appropriate for updating the piecewise material properties in the wave equation and the time stepping of the heat equation are presented. The effects of preheating and source frequency are investigated.

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단상 계통연계 태양광 인버터용 L-C-L 필터 설계 및 분석 (Study and Design of L-C-L Filter for Single-Phase Grid-Connected PV Inverter)

  • 차한주;부우충기엔
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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    • pp.228-230
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    • 2009
  • Nowadays, the LCL-filter type becomes an attractive grid interfacing for grid-connected Voltage Source Inverter (VSI). LCL-filter can render the current harmonics attenuation around the switching frequency by using smaller inductance than L-filter. This paper presents a study about the LCL-filter design for single-phase grid-connected inverter in Photovoltaic (PV) system. According to the expected current ripple, the inductances of the filter can be determined. Based on the absorbed reactive power on capacitor, the capacitance can be calculated. Due to the theoretical analysis, a LCL-filter based single phase grid connected inverter control system are simulated. The studied simulation results are given to validate the theoretical analysis.

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