• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.2
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• pp.56-61
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• 1992

This paper is reported on the simulation and test results of a constant flux vector control scheme of an induction motor without any speed detecting eqiupment, in which the adaptive current PWM inverter is used. The rotor speed is estimated form stator voltage, current and parameters of motor, and control algorithm in the system is performed with by micro processor. By comparing the waveform of input current of this system with that of the case with taco-generator, good agreement is observed except small ripple component. Experimental results which are acquired at start up and during acceleration/deceleration are quite similar to those of the simulation results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.454-456
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• 2017

Current and capacitance-voltage characteristics of tunnel field effect transistor (TFET) with various quantum models were investigated. Density gradient, Bohm quantum potential (BQP), and Vandort quantum correction are used with calibrating against Schrodinger-Poisson model. Drive-currents in all models. are decreased. When only BQP is used, SS and $V_{onset}$ are fixed but drive-current is decreased 3 times more than those of no quantum model. And When BQP with Vandort and density gradient are used, SS increased more than 40 mV./dec and $V_{onset}$ shifted as 0.07 eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.51-51
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• 2008

최근 센서, 전자기술의 발달은 소형 센서 기기의 구동에 필요한 파워를 줄여 주변의 진동이나 온도차등에서의 작은 에너지로도 센서 등의 소형 전자기기의 구동을 가능하게 했다. 이에 따라 전자기기의 구동에너지로써 에너지 하베스팅이 많은 관심을 받고 있다. 압전 효과를 이용하여 주변의 진동에너지를 전기에너지로 변화 시키는 압전에너지 하베스터는 온도차이나 태양광, 바람등과는 달리 날씨나 구동조건에 큰 영항을 받지 않는 장점과 그 크기가 비교적 소형이라는 장점이 있어 많은 연구가 진행되고 있다. 에너지 하베스터에서 생산된 에너지를 사용하기 위해서는 생산된 에너지를 저장장치에 저장해야 한다. 저장장치에 저장하기 위해서는 일정 이상의 전압과 많은 양의 전류가 있는 것이 효과적이다. 하지만 압전 세라믹의 출력 특성은 전압이 크고, 출력 전류가 작은 특성을 지지고 있어 충전 속도가 느리다는 문제점이 있다. 압전세라믹에서 발생되는 에너지는 세라믹의 두께와 세라믹의 전극면적에 비례하는데 각각 세라믹의 두께는 출력 전압에 영향을 주며, 세라믹의 전극면적은 발생하는 전하량에 영항을 준다. 이러한 압전체의 특징을 이용하여 본 연구에서는 압전체의 출력특성의 향상을 위하여 $10\times35mm^2$ 크기의 적층 세라믹을 제작하여 압전에너지 하베스터를 제작하였다. 적층 압전세라믹을 이용한 에너지 하베스터에서 3.5m/$s^2$ 24.6 ${\mu}m$의 진동에서 발생전압 2.14 V 에 발생전류 252 ${\mu}A$의 특성을 얻을 수 있었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.3
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• pp.205-210
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• 2022

A novel OLED pixel circuit is proposed in this paper that uses only n-type thin-film transistors(TFTs) to improve the luminance non-uniformity of the AMOLED display caused by the threshold voltage variation of an OLED driving TFT. The proposed OLED pixel circuit is composed of 6 n-channel TFTs and 2 capacitors. The operation of the proposed OLED pixel circuit consists of the capacitor initializing period, threshold voltage sensing period of an OLED·driving TFT, image data voltage writing period, and OLED·emitting period. As a result of SmartSpice simulation, when the threshold voltage of·OLED·driving TFT varies from 1.2 V to 1.8 V, the proposed OLED pixel circuit has a maximum current error of 5.18 % at IOLED = 1 nA. And, when the OLED cathode voltage rises by 0.1 V, the proposed OLED pixel circuit has very little change in the OLED current compared to the conventional OLED pixel circuit. Therefore, the proposed pixel circuit exhibits superior compensation characteristics for the threshold voltage variation of an OLED driving TFT and the rise of the OLED cathode voltage compared to the conventional OLED pixel circuit.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.06a
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• pp.660-663
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• 1996

• Superconductivity and Cryogenics
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• v.14 no.2
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• pp.28-33
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• 2012

• Superconductivity and Cryogenics
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• v.11 no.1
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• pp.38-44
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• 2009

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.111-121
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• 1999

This paper deals with an active gate drive (AGD) technolo밍T for high power IGBTs. It is based on an optimal c combination of several requirements necessmy for good switching performance under hard switching conditions, The s scheme specifically combines together the slow drive requirements for low noise and switching stress and the fast driver requirements for high speed switching and low switching energy loss The gate drive can also effectively dampen oscillations during low cunent turnlongrightarrowon transient in the IGBT, This paper looks at the conflicting requirements of the c conventional gate dlive circuit design and the experimental results show that the proposed threelongleftarrowstage active gate dlive t technique can be an effective solution.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.1
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• pp.90-96
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• 2006

A novel high power factor drive of a single-phase switched reluctance motor (SRM) is researched. It achieves sinusoidal and near unity power factor input currents. The proposed SRM drive has one additional active switches. And a single-stage approach has a simple structure and low cost. A prototype to drive an SRM equipping a suitable encoder is designed to evaluate the proposed topology. The characteristics and validity of the proposed circuit is discussed with some simulations and experimental results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.509-513
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• 2003

In this paper, we configured secure communication circuit with PSpice through Embedding Drive Synchronization using SC-CNN, SC-CNN provide us a good method to separate interconnected state variables of a system respectively and to make it possible to change current component to voltage component in the state variables.