• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1997년도 추계학술발표회논문집
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• pp.14-17
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• 1997

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.59.2-59
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• 1998

• 조명전기설비학회논문지
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• 제16권2호
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• pp.113-120
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• 2002

본 논문은 인체에 의해 발생하는 정전기 방전과도전압 파형의 특성에 관한 것으로 정전기 방전전압의 피크 크기와 초기상승부분의 특성에 대한 통계를 분석하기 위해서 여러 가지 실험조건에서 정전기 방전전압을 측정하였다. 정전기 방전전압의 측정에는 주파수대역이 DC∼400[MHz]인 전압측정계를 사용하였으며, 정전기 방전전압의 파형은 전류 파형과 거의 동일하였다. 또한 본 연구에서 제안한 등가회로를 적용한 시뮬레이션결과는 측정결과와 거의 일치하였다. 정전기 방전전압 파형은 접촉 물체의 재질과 접근속도에 크게 영향을 받으며, 빠른 접근일 때가 느린 접근일 때보다 초기상승시간이 짧은 파형으로 나타났다. 손에 의한 정전기 방전전압의 상승시간은 10∼30[ns]로 비교적 길었으나, 크기는 작았다. 반면에 절연손잡이를 갖는 드라이버를 통한 정전기 방전전압 파형은 1[ns]이하의 매우 짧은 상승시간과 매우 큰 피크값을 나타내었다. 본 연구결과는 저전압 소전류인 전자기기의 정전기 장해에 대한 대책의 마련에 응용될 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.95-101
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• 2005

In the heart, $Na^{+}-Ca^{2+}$ exchange (NCX) is the major $Ca^{2+}$ extrusion mechanism. NCX has been considered as a relaxation mechanism, as it reduces global $[Ca^{2+}]_i$ raised during activation. However, if NCX locates in the close proximity to the ryanodine receptor, then NCX would curtail $Ca^{2+}$ before its diffusion to global $Ca^{2+}_i$ This will result in a global $[Ca^{2+}]_i$ decrease especially during its ascending phase rather than descending phase. Therefore, NCX would decrease the myocardial contractility rather than inducing relaxation in the heart. This possibility was examined in this study by comparing NCX-induced extrusion of $Ca^{2+}$ after its release from SR in the presence and absence of global $Ca^{2+}_i$ transient in the isolated single rat ventricular myocytes by using patch-clamp technique in a whole-cell configuration. Global $Ca^{2+}_i$ transient was controlled by an internal dialysis with different concentrations of BAPTA added in the pipette. During stimulation with a ramp pulse from +100 mV to -100 mV for 200 ms, global $Ca^{2+}_i$ transient was suppressed only mildly, and completely at 1 mmol/L, and 10 mmol/L BAPTA, respectively. In these situations, ryanodine-sensitive inward NCX current was compared using $100{\mu}mol/L$ ryanodine, $Na^+$ depletion, 5 mmol/L $NaCl_2$ and $1{\mu}mol/L$ nifedipine. Surprisingly, the result showed that the ryanodine-sensitive inward NCX current was well preserved after 10 mmol/L BAPTA to 91 % of that obtained after 1 mmol/L BAPTA. From this result, it is concluded that most of the NCX-induced $Ca^{2+}$ extrusion occurs before the $Ca^{2+}$ diffuses to global $Ca^{2+})i$ in the rat ventricular myocyte.

• 대한전자공학회논문지
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• 제25권11호
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• pp.1294-1303
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• 1988

광 유도 전류 천이 (photo-induced current transient)방법으로 측정한 SI GaAs의 전자와 정공 trap이 갖을 수 있는 activation energy({\Delta}E_r)의 범위는 0.16$\pm$ 0.01eV에서 0.98$\pm$ 0.01eV까지 분포되어 있다. SI Undoped GaAs가 SI GaAs : Cr 보다 깊은 준위의 수가 적음을 확인 하였다. Trap의 열적인 capture cross section과 농도를 평가 하였고, 약간의 trap은 SI GaAs 성장시에 발생될 수 있는 결함과 관련되어 있음을 확인하였다. 특히 SI GaAs에서 보상 level로 작용하는 Cr과 “0” level를 좀 더 정확하게 측정하기 위하여 서로 다른 측정방법을 사용하여 측정한 결과를 각기 비교 검토 하였다. 즉, PICT측정, 상온 이상의 온도에서 측정한 Hall data 및 광전류 spectra data 등을 비교 검토 하였으며, 보상 level은 격자 결합이 매우 약함을 확인할 수 있었다. Hall data를 computer로 분석한 결과 중성 불순물 scattering이 측정 온도 범위에서 매우 중요한 역할을 하고 있음을 알 수 있었다.

• Journal of Power Electronics
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• 제16권5호
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• pp.1884-1893
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• 2016

The ride-through control of a doubly-fed induction generator (DFIG) for the voltage sags on wind farms utilizing crowbar circuits by which the rotor side converter (RSC) is disabled has being reported in many literatures. An analysis and calculation of the transient current when the RSC is switched off are of significance for carrying out the low voltage ride through (LVRT) of a DFIG. The mathematical derivation is highlighted in this paper. The zero-state and zero-input responses of the transient current in the frequency domain through a Laplace transformation are investigated, and the transient components in the time domain are achieved. With the characteristics worked out from the linear resolving without modeling simplification, the selection of the resistance in the linear crowbar circuit and the value conversion from a linear circuit to a nonlinear one is proposed to setup the attenuation rate. In terms of grid code requirements, the theoretical analysis for the time constant of the transient components attenuation insures the controllability when the excitation of the RSC is resumed and it guarantees the reserved time for the response of the reactive power compensation. Simulations are executed in MATLAB/SIMPOWER and experiments are carried out to validate the theoretical analysis. They indicate that the calculation method is effective for selection of the resistance in a crowbar circuit for LVRT operations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.404-408
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• 2000

The novel control method of ZVS Full-bridge PWM converter with pulse load current is proposed. This new control method can reduce the switching loss of switches during no load condition. Moreover by using feed-forward load current information this method can obtain better transient dynamics compared to the system with only linear feedback control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.52-54
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• 2005

This paper describes an exciting current calculation method for transformers by finite element method. In case of a special case such as air-gap presence, one can not calculate exciting current accurately using exciting power curves due to flinging effect, magnetic saturation and so on. Transient analysis with external circuit is performed with a 2D model and compared to a test result.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.266-268
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• 2005

A new synchronous switch controlled transient current build-up zero voltage switching (TCB-ZVS) forward converter is proposed. The proposed converter is suitable for the low-voltage and high-current applications. The features of the proposed converter are low conduction loss of magnetizing current, no additional circuit for the ZVS operation, high efficiency, high power density and low EMI noise throughout all load conditions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.475-476
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• 2007

The stress induced leakage currents will affect data retention in synapse transistors and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor made by thin silicon oxides has represented the neural states and the manipulation which gaves unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhibitory state according to weighted values affected the channel current. The stress induced leakage currents affected excitatory state and inhibitory state.