• 제목/요약/키워드: Electrical engineering

검색결과 42,388건 처리시간 0.054초

인체 근육에 있어서 신호 전송계수의 계측 (A measurement of signal transmission parameters in human muscle)

  • 이현철;이승주;김기영;윤재현;윤양웅;박형준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 D
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    • pp.2699-2701
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    • 2002
  • In this study, a system for measurement of impedance (transmission parameter) on the human muscle was constructed. The system composed of the stimulating part for input with milli-voltage and the measuring part for measurement of transmission voltage in human muscle. As a result of this experiment, the frequency characteristic of each subject represent that the transmission voltage goes up in spite of a constant input voltage according to frequency (1Hz -50kHz) increment. Namely, the amplitude of input signal was not reflected but frequency was reflected on the measured results. This result be estimated that the proposed system is able to measure passive electrical characteristic of human body.

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광대역 AE 센서에 의한 유중코로나의 초음파 특성 (Ultrasonic Characteristics of Oil Corona by Wide-Band AE Sensor)

  • 김인식;이상우;김성규;구경철;이광식;이동인
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 E
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    • pp.2338-2340
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    • 1999
  • In this paper measurements of AE (Acoustic Emission) signals caused by corona discharge were performed to analyze the electrical deterioration in oil. We also examined the relationship between discharge magnitude and peak-to-peak value of AE signals to diagnose the deterioration of liquid dielectrics. From these results, Vpp(peak to peak value) of AE signals was proportional to corona discharge magnitude. The main frequency band of AE signals in oil appeared to 130[kHz].

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9/65/35 PLZT 박막의 유전적, 전기적 특성 (Dielectrical and Electrical Characteristics of 9/65/35 PLZT Thin Films)

  • 강종윤;최형욱;백동수;윤현상;신현웅;박창엽
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1305-1307
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    • 1994
  • 9/65/35 PLZT thin films were prepared by sol-gel processing and annealed by direct insertion, 9/65/35 PLZT thin films were poly-crystallized after direct insertion at $750^{\circ}C$ for 3omin. The grain size of film was 50 nm, coercive field was 28.2 kV/cm and remnant polarization was $3.68 {\mu}C/cm^2$.

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Pulsed Actuator with Combined Plunger Made of Carbon Steel and Permanent Magnet

  • Dolezel, Ivo;Panek, David;Ulrych, Bohus
    • Journal of international Conference on Electrical Machines and Systems
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    • 제1권3호
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    • pp.282-288
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    • 2012
  • A special pulsed electromagnetic actuator is presented whose plunger consists of two parts made of carbon steel and permanent magnet, respectively. The actuator exhibits a high holding force and small consumption of energy. The movement of the plunger is controlled by short current pulses. The static characteristics and other operation properties of the device are modeled numerically.

Low-Cost SVM-DTC Strategy of Induction Machine Drives Using Single DC-link Current Sensor

  • Wang, Wei;Cheng, Ming;Hua, Wei;Ding, Shichuan;Zhu, Ying;Zhao, Wenxiang
    • Journal of international Conference on Electrical Machines and Systems
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    • 제1권3호
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    • pp.266-273
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    • 2012
  • In conventional direct torque control (DTC) using space-vector modulation (SVM) of induction machine (IM) drives, at least three current sensors are needed. In this paper, a low-cost SVM-DTC strategy is proposed, in which only a single current sensor is used. The position of the voltage space vector is divided into two areas: effective and non-effective area. If it is located in the non-effective area, the voltage space vector will be shifted into the effective area with minimum distortion. Further, the switching frequency remains constant. The simulation is carried out on a MATLAB/Simulink platform and the simulated results verify the effectiveness of the proposed strategy.

Biracial Silicon Solar Cells with Spin-on Doping and Electroless Plating

  • U. Gangopadhyay;Kim, Kyung-Hae;S.K. Dhungel;D. Mangalaraj;Park, J.H.;J. Yi
    • Transactions on Electrical and Electronic Materials
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    • 제5권1호
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    • pp.7-10
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    • 2004
  • A new method for fabrication of transistor like structure of the bifacial solar cell using spin-on doping and electroless plating has been proposed and the basic characteristics of the bifacial cell have been investigated. It is found that 9% increase in short circuit current is achieved with bifacial connection than the unifacial connection. Some unwanted effect of the series resistance on collection efficiency under different mode of illumination has been pointed out. Loss mechanisms inherent in the transistor like bifacial structure have also been discussed.

Dynamic Characteristic Analysis of Electric Actuator for 1 kV/3.2 kA Air Circuit Breaker Based on the Three-link Structure

  • Lee, Seung-Min;Kang, Jong-Ho;Kwak, Sang-Yup;Kim, Rae-Eun;Jung, Hyun-Kyo
    • Journal of Electrical Engineering and Technology
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    • 제6권5호
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    • pp.613-617
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    • 2011
  • In the present paper, a new type of electrical actuator, an electromagnetic force driving actuator (EMFA), applicable to air circuit breaker is developed and analyzed. Transient analysis is performed to obtain the dynamic characteristics of EMFA. The distribution of static magnetic flux is obtained using the finite element method. The coupled problems of electrics and mechanics governing equations are solved using the time-difference method. According to the interception rate of each contactor, investigation of the contactor spring load condition is conducted and applied to the threelink system. Comparisons of the dynamic characteristics of the three-link simulation and experimental data are performed.

유기 박막 트랜지스터의 스파이스 모형화 (SPICE Modeling of Organic Field Effect Transistors (OFETs))

  • 이재우;박응석;박소정;장도영;김강현;김규태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.142-143
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    • 2006
  • Organic thin film transistors(OTFTs) were simulated by a SPICE model adopted in the amorphous TFTs(a-Si:H TFTs). The gate voltage-dependent mobilities were assumed to fit the representative current-voltage characteristics. The optimal fitting procedures were suggested to compare the experimental data with the mathematical expressions used in the amorphous TFTs. Each SPICE parameter explains the gate dependent mobilities in OTFTs which might originate from the influence of the hopping conduction.

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아르곤 압력에 따른 유도결합형 폴라즈마의 전기적 특성 (Electrical Properties of Inductively Coupled Plasma by Argon Pressurebstract)

  • 이영환;허인성;조주웅;김광수;이종찬;최용성;박대희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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    • pp.89-91
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    • 2003
  • In this paper, using a Langmuir probe Ar gas characteristic of electrodeless fluorescent lamp which used an inductively coupled plasma were investigated. The RF output changed into 5-50W in 13.56MHz. At this time internal plasma voltage of the chamber and probe current were measured while changing in -70V - +70V with a supply voltage by Langmuir probe. If pressure of Ar gas was increased, the electric current tended to decrease. Also, an electric current was increased according to an increase of a RF output.

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Device modelling and performance analysis of two-dimensional AlSi3 ballistic nanotransistor

  • Chuan, M.W.;Wong, K.L.;Hamzah, A.;Rusli, S.;Alias, N.E.;Lim, C.S.;Tan, M.L.P.
    • Advances in nano research
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    • 제10권1호
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    • pp.91-99
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    • 2021
  • Silicene is an emerging two-dimensional (2D) semiconductor material which has been envisaged to be compatible with conventional silicon technology. This paper presents a theoretical study of uniformly doped silicene with aluminium (AlSi3) Field-Effect Transistor (FET) along with the benchmark of device performance metrics with other 2D materials. The simulations are carried out by employing nearest neighbour tight-binding approach and top-of-the-barrier ballistic nanotransistor model. Further investigations on the effects of the operating temperature and oxide thickness to the device performance metrics of AlSi3 FET are also discussed. The simulation results demonstrate that the proposed AlSi3 FET can achieve on-to-off current ratio up to the order of seven and subthreshold swing of 67.6 mV/dec within the ballistic performance limit at room temperature. The simulation results of AlSi3 FET are benchmarked with FETs based on other competitive 2D materials such as silicene, graphene, phosphorene and molybdenum disulphide.