• Title/Summary/Keyword: Current Continuity Condition

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Effects of Coulomb Gauge Condition and Current Continuity Condition on 3-Dimensional FE Analysis for Eddy Current Problems (3차원 와전류문제의 유한요소해석에서 쿨롱게이지조건과 전류연속조건의 영향)

  • Lee, Hyang-Beom
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.10
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    • pp.483-491
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    • 2005
  • To solve the 3D eddy current problems by using FE(finite element) method with MVP(magnetic vector potential) and electric scalar potential, Coulomb gauge condition and current continuity condition have to be considered. Coulomb gauge condition enforced on existing FE formulations to insure the uniqueness of MVP looks unnatural and current continuity condition which can be driven from Ampere's law looks unnecessary. So in this paper the effect of two conditions on FE formulations are investigated in order to help to obtain accurate numerical simulation results.

Study on the Electric Continuity Measurements of Green Car for Human Body Safety (친환경자동차의 인체 안전을 위한 전기적 연속성 측정 연구)

  • Kim, Hyang-Kon;Lee, Ki-Yeon;Kim, Dong-Ook;Choi, Hyo-Sang
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.3
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    • pp.351-356
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    • 2009
  • In this study, we analyzed and experimented about electric continuity for human body safety from green cars. And we compared power systems of HEV and examined about human body effect of current and time. We investigated internal and external standards and regulations for human body safety from high voltage electrical equipments. Indirect contact refers to contact between the human body and exposed conductive parts. According to UNECE R100, ISO 23273-3, ISO 6469-3 and Japanese Regulation Attachment 101, electric continuity between any two exposed conductive parts shall not exceed $0.1{\Omega}$. The value of electric continuity was measured below $0.1{\Omega}$ at the actual condition of green car. We expected that the results of these experiments can utilize to data for electrical safety of green car.

QoS Management Mechanism for Heterogeneous Networks (이종 망을 위한 QoS 관리 체계)

  • Lee, Gi-Sung;Lee, Jong-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2393-2398
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    • 2014
  • Because each resource in LTE-Advanced system and network's shapes such as bandwidth, error rate change variably, it is judged that it is impossible to control service continuity with procedural, artificial, and static control method applied to the existing voice service. This research suggests a QoS management mechanism to support the service continuity effectively based on policy control. It means a method in which a subscriber's terminal collects information about its current condition and base station around, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling service continuity on its own.

Service Self-Organization Method in LTE-Advanced Heterogeneous Networks (LTE-Advanced 융합 망에서 서비스 자기-조직화 방법)

  • Lee, Gi-Sung;Lee, Jong-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6260-6268
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    • 2015
  • In LTE-Advanced that different networks coexist, it is considered that it is actually difficult to provide service continuity with a procedural and static control method applied to the existing voice service. This paper suggests Service Self-Organization to support the service continuity effectively based on SON. It means a method in which a subscriber's terminal collects information about its current condition and base station around, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling service continuity on its own. In other words, as context information of mobile terminal and base station changes, set-up of related functions such as ISHO, cell selection, source allocation, load control, and QoS mapping is adapted; each function fits into the change, exchanges the process of reorganization, and interacts; these actions go toward to satisfy service continuity. Simulation results show that it provides better performances than the conventional one with the measure of resource utilization rate and outage probability.

Computer Simulation of Pt-GaAs Schottky Barrier Diode (Pt-GaAs Schottky Barrier Diode의 Computer Simulation)

  • Yoon, Hyun-Ro;Hong, Bong-Sik
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.3
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    • pp.101-107
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    • 1990
  • In this work, one-dimensional simulation is carried out for PT-GaAs Schottky barrier diodes with finite difference method. Shockley's semiconductor governing equations: Poisson equation and current continuity equation are discertized, and linearized by Newton-Raphson method. The linear system of equation is solved by Gaussian elimination method until convergence is achieved. The boundary condition for this equation is taken from thermionic emission-diffusion theory. Simulation is done for PT-GaAs epitaxial-layer Schottky barrier diodes. The claculated results of electron and potential distribution are shown. Simulation results show exellent agreement with experiments.

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Quantum-Mechanical Modeling and Simulation of Center-Channel Double-Gate MOSFET (중앙-채널 이중게이트 MOSFET의 양자역학적 모델링 및 시뮬레이션 연구)

  • Kim, Ki-Dong;Won, Tae-Young
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.7 s.337
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    • pp.5-12
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    • 2005
  • The device performance of nano-scale center-channel (CC) double-gate (DG) MOSFET structure was investigated by numerically solving coupled Schr$\"{o}$dinger-Poisson and current continuity equations in a self-consistent manner. The CC operation and corresponding enhancement of current drive and transconductance of CC-NMOS are confirmed by comparing with the results of DG-NMOS which are performed under the condition of 10-80 nm gate length. Device optimization was theoretically performed in order to minimize the short-channel effects in terms of subthreshold swing, threshold voltage roll-off, and drain-induced barrier lowering. The simulation results indicate that DG-MOSFET structure including CC-NMOS is a promising candidates and quantum-mechanical modeling and simulation calculating the coupled Schr$\"{o}$dinger-Poisson and current continuity equations self-consistently are necessary for the application to sub-40 nm MOSFET technology.

A Monitoring Method for Supporting QoS in Next Generation Mobile Communication Networks (차세대 이동통신망의 QoS를 보장하기 위한 모니터링 방법)

  • Lee, Gi-Sung;Lee, Jong-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3680-3686
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    • 2012
  • This research suggests a monitoring method to support QoS of mobile multimedia services effectively based on information gathering. It means a method in which a subscriber's terminal collects information about its current condition and its surrounding base stations, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling QoS on its own. In other words, as context information of mobile terminal and base station changes, set-up of related functions and QoS mapping is adapted; each function fits into the change, exchanges the process of reorganization, and interacts; these actions go toward to satisfy service continuity.

Numerical Wave Tank Technology for Multipurpose Simulation in Marine Environmental Engineering (해양환경공학의 다목적 시뮬레이션을 위한 수치파랑수조 기술)

  • 박종천
    • Journal of Ocean Engineering and Technology
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    • v.17 no.4
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    • pp.1-7
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    • 2003
  • A virtual reality technology for multipurpose numerical simulation is developed to reproduce and investigate a variety of ocean environmental problems in a 3D Numerical Wave Tank(NWT). The governing equations for solving incompressible fluid motion are Navier-Stokes equation and continuity equation. The Marker-Density function technique is adopted to implement the fully nonlinear freesurface kinematic condition. The marine environmental situations, i.e., waves, currents, etc., are reproduced by use of multi-segmented wavemakers on the basis of the so-called ″snake-principle″. In this paper, some numerical reproduction techniques for regular, and irregular waves, multi-directional waves, Bull's-eye wave. wave-current, and solitary wave are presented, and a model test in motion with large amplitude of roll angle is conducted in the developed 3D-NWT, using a overlaid grid system.

An Experimental Study on Thawing of Frozen Fish by the Vacuum System (진공장치를 이용한 동결어류의 해동에 관한 실험적 연구)

  • Choi, H.K.;Choe, S.Y.
    • Journal of Power System Engineering
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    • v.10 no.2
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    • pp.62-67
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    • 2006
  • The maintenance of continuity on food processing has created a need for the rapid reinstatement of many types of frozen fish to an ambient temperature and good condition. A number of thawing methods are in current use have also several disadvantages in thawing time. discoloration mass loss caused by drying, capital and running cost. These damages are, it is claimed, either eliminated or improves by the vacuum system. An experimental study on the thawing for hair tail and Yellow croaker by the vacuum system were carried out. The Yellow croaker thawing time with this vacuum system took out 170 minutes to reach from $-10.3^{\circ}C\;to\;-0.8^{\circ}C$ at 20mmHg abs. and hair tail thawing time 220 minutes to reach from $-12.2^{\circ}C\;to\;0^{\circ}C$ at 20mmHg abs.

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Reduction of switching loss and low-order harmonics in three-phase PWM inverter using the selected harmonic elimination (특정고조파제거기법을 이용한 3상 PWM 인버터의 저차고조파제거 및 스위칭손실 저감에 관한 연구)

  • Jang, Chul;Lee, Byung-Jin;Yun, Jae-Sung;Suh, Yoon-Chul;Yu, Chul-Ro
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1960-1962
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    • 1998
  • Reference/modulating waveform continuity is not a necessary condition for the implementation of switching patterns for three-phase pulse-width modulated(PWM) converters. This is based on the fact that the converter phase-voltages do not need to be sinusoidal and switching pattern discontinuities do not degrade the quality of output/input voltage/current waveforms by introducing low-order harmonics if certain parameters are optimized. This paper introduces the selected harmonic elimination to reduce the switching frequency and low-order harmonics compared with continuous PWM techniques and some discontinues switching patterns for PWM converter.

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