• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 추계학술대회 논문집
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• pp.45-48
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• 2004

To improve the efficiency characteristics in the resonant converter using the contact-less power supply with the large air-gap and the long primary winding, this paper suggests the three-level series-parallel resonant converter(SPRC). The voltage gain characteristics of the proposed converter have the unit gain in a resonance frequency point of the series and parallel, and input voltage and current in the primary of SPRC are always In phase for the all equivalent load resistance because of the parallel resonant tank of the high impedance. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental prototype.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권9호
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• pp.434-437
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• 2001

ZnSe, ZnSe:Ho/sup 3+/, Mg/sub x/Zn/sub 1-x/Se and Mg/sub x/Zn/sub 1-x/Se:Ho/sup 3+/ crystals were grown by the chemical transport reaction method. The crystal structures and optical energy band gaps of the single crystals were investigated. Their photoluminescence(PL) spectra were measured at 10 [K]. Sharp emission peaks in the blue-green wavelength range and broad emission peaks in the yellow-red wavelength range were observed. The single crystals doped with 1.0 [mol%] of holmium did not show the sharp emission peaks because of defects which were thought to be originated to the holmium dopant.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2006년도 추계공동학술대회
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• pp.361-365
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• 2006

Air pollution problem has been one of the most urgent global environmental problems since UN Framework Convention on Climate Change accepted in Rio Conference, 1992. International environmental regulations of global community to reduce the green house gases have Influenced the domestic environmental policies. Recently, various policy have been made to cope with foreign environment restrction and active supports for development of related technology have been carried out in our government confrontation strategy still leaves much to be desired. In this paper, government confrontation program to climate agreement, counter strategies in motor and also electrics, electronics industries are investigated and discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.175-178
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• 2000

The resonance characteristic of microstrip antenna with an airgap between the substrate layer and ground plane is investigated. The study is performed by using a rigorous Green’s function formulation in the spectral domain and Galerkin’s moment method calculation. The numerical convergence using sinusoidal basis functions, the unknown surface current distribution in the rectangular patch, is discussed. Numerical result for the effects of airgap and patch length on the complex resonant frequencies of the rectangular microstrip structure are also presented

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.102-105
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• 2005

For transferring the primary power to the secondary one, the high frequency series resonant converter has been widely used for the contactless power supply system. However, the high frequency series resonant converter has the disadvantages such as the low efficiency, the high voltage gain characteristics and deviation of the phase angle in the overall load range. To improve this disadvantage, In this paper, the characteristics of the high efficiency and unit voltage gain as well as in phase are revealed in the proposed three-level LCLC ( Inductor - Capacitor - Inductor -Capacitor)resonant converter. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental prototype.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.424-425
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• 2018

In the introduction, this paper introduces LS Industrial Systems' medium-voltage drive installed at Hyundai Green Power, an 800MW gas power plant. In the body, it explains the synchronous transfer technology and new speed search technology applied to Forced Draft(FD) Fan and Boiler Feed-water(BF) Pump, which are power generation facilities. Lastly, it shows the annual energy saving amount and operation status which are applied to each facility and proves that it is a successful application case.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.339-341
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• 2009

A transparent plasma display was developed using transparent glass barrier ribs. Glass barrier ribs were fabricated via a wet etching process. Glass barrier ribs created using a top and bottom etching process showed better transparency compared to those created through only a top etching process. A see-through phosphor layer was obtained by coating the sidewall of the barrier ribs with a conventional opaque phosphor. A fabricated prototype of a transparent plasma display was clear enough to see the background beyond the panel and was well operated by a conventional driving scheme. The maximum luminance was 1150 cd/$m^2$ and the maximum luminous efficacy was 1.35 lm/W in a Ne+13.5%Xe gas-mixture and green cells.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.327-328
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• 2013

대용량 전력변환기에서 필터로 사용되는 인덕터의 특성은 전력변환 효율 및 전력 품질에 결정적인 역할을 하는 매우 중요한 수동소자이다. 따라서 PWM 방식의 대용량 전력변환장치에서 특성이 좋은 인덕터를 사용하는 것은 매우 중요하다. 이러한 인덕터의 특성을 분석하기 위해서는 인덕터의 자기적 포화를 관찰하기 위한 펄스전압에 의한 전류특성을 분석하는 방식과 DC 중첩 특성을 사용하여 전류리플에 따른 인덕터의 특성 분석 방식을 사용한다. 따라서 본 연구에서는 이러한 특성을 분석하기 위해서 펄스전압 및 DC 중첩을 발생할 수 있는 장비를 제작하고 이를 분석할 수 있는 장치를 개발하였다.

• Journal of Information Display
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• 제2권1호
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• pp.14-19
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• 2001

Plasma display panel(PDP) have gained great attention due to their potential application to large-area display including HDTV. The luminance and luminous efficiency of PDP, however, should be improved to realize this goal. In this study, we examined experimentally the effects of phosphor thickness and discharge gap on the luminance and luminous efficiency of ac PDP. For the rib height of 110 ${\mu}m$, whereas the optimum phosphor thickness was about 30 ${\mu}m$. The optimum thickness of green phosphor was about 50 ${\mu}m$ for the rib height of $120{\sim}160\;{\mu}m$.

• Journal of Communications and Networks
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• 제6권2호
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• pp.133-146
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• 2004

Recently, many active queue management (AQM) algorithms have been proposed to address the performance degradation. of end-to-end congestion control under tail-drop (TD) queue management at Internet routers. However, these AQM algorithms show performance improvement only for limited network environments, and are insensitive to dynamically changing network situations. In this paper, we propose an adaptive queue management algorithm, called PID-controller, that uses proportional-integral-derivative (PID) feedback control to remedy these weak-Dalles of existing AQM proposals. The PID-controller is able to detect and control congestion adaptively and proactively to dynamically changing network environments using incipient as well as current congestion indications. A simulation study over a wide range of IP traffic conditions shows that PID-controller outperforms other AQM algorithms such as Random Early Detection (RED) [3] and Proportional-Integral (PI) controller [9] in terms of queue length dynamics, packet loss rates, and link utilization.