• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.278-281
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• 2014

본 논문에서는 진동에너지 하베스팅을 위한 세 가지 종류의 전파 정류기를 비교 분석 하였다. 첫번째 정류기는 두 개의 능동 다이오드(active diode)와 두 개의 MOSFET로 구성된 전파 정류기로 능동 다이오드의 비교기는 정류기의 출력으로부터 전력을 공급받는다. 두 번째는 네 개의 MOSFET로 구성된 정류기와 하나의 능동 다이오드로 구성된 2단 정류기이며, 마찬가지로 비교기는 정류기의 출력으로부터 전력을 공급받는다. 세 번째는 두 번째 정류기와 동일한 구조이나 비교기의 전력을 정류기의 입력으로부터 공급받는 input-powered 정류기이다. 이 정류기들을 0.35um CMOS 공정으로 설계하고 모의실험을 통해 성능을 비교, 분석하였다. 부하가 큰 경우에는 첫 번째 정류기를 이용하는 것이, 부하가 작은 경우에는 두 번째 정류기를 이용하는 것이 효율적인 측면에서 유리하다. 또한 효율보다는 진동에너지의 유무에 따른 전력 소모가 중요하다면 세 번째 정류기가 유리하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.478-481
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• 1991

This paper discusses the principle and structure of instantaneous voltage drop compensator, which protects damage from instantaneous voltage drop in systems such as computer, variable speed drive, high voltage discharge-lamp, magnet switch. When instantaneous voltage drop occurs, control circuits detect it, then produce output voltage the same as normal condition voltage. Instantaneous voltage drop compensator has condenser bank as energy storage component, so system can be made small, light weight compared with UPS. In normal state, utility source transfers power, and in instantaneous voltage drop state, the energy of condenser bank transfers power through inverter, so high efficiency, compact, and especially low cost system can be manufactured.

• 전기학회논문지P
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• 제60권4호
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• pp.253-256
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• 2011

LEDs have small size, long lifespan, high reliability, low power consumption and high color efficiency. Using such a characteristics, LED Back Light Unit has been studying actively. This paper proposes LED driver to minimize power consumption due to LED forward voltage($V_F$) difference and temperature rising. Compared to conventional LED driver, the proposed driver have excellent stability, brief structure and linear output voltage of DC-DC boost converter. Proposed LED Driver circuit was designed using 0.35um CMOS technology. And its operation was verified through simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.262-265
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• 2003

In this paper, a new active snubber circuit that overcomes most of the drawbacks of the normal "zero voltage transition pulse width modulation" (ZVT-PWM) converter is proposed to contrive a new family of ZVT- PWM converter. A converter with the proposed snubber circuit can also operate at light load conditions. A design procedure of the proposed active snubber circuit is also presented. Additionally, at full output power in the proposed soft switching converter, the main switch loss is about 27[%] and the total circuit loss is about 36[%] of that in its counterpart hard switching converter, and so the overall efficiency, which is about 91[%] in the hard switching case, increases to about 97[%].

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.321-324
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• 2004

This paper presents a package IC containing some components of DC/DC converter block for mobile phone's sub OLED(Organic Light Emitting Display). Package IC contains a load switch, a control IC, a diode, a switch for on/off operation, and a switch for changing output voltage. It operates with switching frequency of 100kHz, within the range of input voltage, $3.2V\~5.5V$. Duty ratio can be changed up to $93\%$, and maximum power efficiency is $85\%$. This package IC is loaded onto three model of 1.2W mobile phone's sub-OLED.

• 전자공학회논문지A
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• 제33A권7호
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• pp.253-260
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• 1996

In this paper, a simple scheme of two-stage free-space photonic swiching system for nonblocking optical interconnections has been investigated using holgorams. The multistage system requires a smaller number of interconnections for a given number of inpuut-output nonblocking ports than the single stage system does. Here hologram elements were used to change interconnection beam paths. In order to increase the idffraction efficiency of the hologram elements in photographic plates, a bleaching technique was used, which converts the amplitude hologram to the phase hologram. To show sthe feasibility of our optical interconnection system, it was implemented using the bleached hologram arrays and an LCTV spatial light modulator, and the sytem as a photonic switching system was demonstrated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.268-271
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• 1993

Discharge pumped high power excimer laser is a very useful light source of ultraviolet region. In this paper. the design and operation characteristics of UV pre-ionized discharge pumped XeCl laser are discussed. Maximum output power of 890mJ at the efficiency of 1.4% was achieved with 35kV charging voltage, 3.4atm of total pressure and 10pps of pulse repetition rate. Optimum HCl pressure is considered to be between 2.5 and 3.5torr.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.248-254
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• 2012

In the situation of expanding domestic solar power supply business long-term performance modeling of a proposed solar-cooling and cleaning system to increase electromotive force and light transmission is carried out to test the effectiveness of the system. To test the effectiveness of the system, the data which comparing the solar power planet installing the system to not installing at the same time is used. A difference between the utilization factor of each comparison group were recorded. Approximately from one year to two years Field Test was performed, Result of apply to cooling/cleaning technology, Each of plant by From least 7 percent up to 16 percent utilization factor increased, and the cooling / cleaning is output through improved as a result of the determined.

• Journal of the Optical Society of Korea
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• 제4권2호
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• pp.79-85
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• 2000

The main purpose of this paper is to present the potential of photovoltaic systems using holographic solar concentrators. A hologram used here focuses light, spectrally splits it and diverts unwanted infrared heat away from the solar cell. The output of the hologram appears as a perpendicular thin spectral line and is displaced to solar cells on both sides. To obtain optimum design conditions we used the coupled wave theory and the vector ray tracing method. The measured data showed that the diffraction efficiency was 75 ％ and the spectral bandwidth was 350 nm.

• 전자공학회논문지A
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• 제29A권4호
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• pp.14-21
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• 1992

An optical novelty filter is implemented using photorefractive materal(BaTiO$_{3}$) as a recording materal and commercial liquid crystal TV as a spatial light polarization modulator. If a signal beam incident at the proper, the loop and the crossing angle inside th e crystal is formed to get maximum diffraction efficiency and BaTiO$_{3}$ as a self-pumped phase conjugation mirror show that phase conjugate reflectivity was 20 times as much as ordinary polarization if signal beam is extraordinary. In this paper, the stoke's theorem which is a reciprocal theorem for which is a reciprocal theorem for beam path is experimentally proved, and good output images were obtained with optical experiment of novelty filter which is formed by use of Michelson interferometer.