• Proceedings of the KIEE Conference
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• 2004.07e
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• pp.88-91
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• 2004

In order to improve ozone generation, we experimentally investigated the silent discharge plasma and ozone generation characteristics of a multi-discharge type ozonizer. Ozone in a multi-discharge type ozonizer is generated by superposition of a silent discharge plasma, which is simultaneously generated in separated discharge spaces. A multi-discharge type ozonizer is composed of three different kinds of superposed silent discharge type ozonizers, depending on the method of applying power to each electrode. We observed that the discharge period of the current pulse for a multi-discharge type ozonizer can be longer than that of silent discharge type ozonizer with two electrodes and one gap.Hence, ozone generation is improved up to 17185 ppm and 783 g/kwh for the superposed silent discharge type ozonizer for which an AC high voltages with a 180 phase difference were applied to the internal electrode and the external electrode, respectively, with the central electrode being ground

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.6
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• pp.35-42
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• 2000

In this paper, AE(Acoustic Emission) signals detected from the growth of the electrical tree in an epoxy resin under ac high-voltage application were analysed to diagnose the insulation deterioration of cast-resin power transformer. Frequency spectra of AE signals generated from the magnetizing and the load currents in the actual operating cast-resin power transformer of 500[kVA] under distribution system of 22.9[kV] were also analysed to distinguish the AE signals due to void discharges from the magnetic circuit noises in the core of the transformer. As the experimental results, we could distinguish the AE signals whether those signals were caused due to the void discharges or due to the magnetic circuit noises by analyzing the frequency spectrum of AE signals. The frequency spectra of AE signals generated from the cast-resin power transformer in operation due to both the magnetizing and the load currents appeared in the range of 40-120[kHz], but the frequency band of AE signals emitted from the void discharges in an epoxy resin sample was about 50[kHz] to 230[kHz].

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.92-92
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• 2016

전기방전의 기본적인 특성을 가지고 있는 플라즈마를 이용하여 재료를 가공하는 증착, 식각, 표면처리 공정에 있어서 플라즈마 내의 전자 충돌 반응에 의한 이온, 라디칼의 생성과 재료 표면의 반응을 분석하는 도구로써 분압 측정은 일반적인 화학 조성 분석에 기원한 오랜 역사를 가지고 있다. 1 amu 정도의 분해능을 가지고 있고 크기가 30 cm 정도에 불과한 사중극자 질량 분석기는 적절한 질량 스캔 시간과 넓은 이온 전류 측정 범위를 가지므로 소형 차등 배기 시스템과 조합하면 1 mTorr 영역의 스퍼터링 시스템에서 1 Torr 영역의 PECVD/PEALD 시스템 진단에도 쉽게 적용이 가능하다. Inficon사의 CPM-300과 Pfeiffer사의 Prisma80을 이용한 플라즈마 식각 공정 분석 결과를 보면 동위원소까지 분석이 가능하다. 또한 전자충돌 이온화 에너지를 조절하여 m/q(질량전하비율)가 중첩되는 경우의 해석도 가능하다. 다중 오리피스를 갖는 compact design의 밸브 블록을 이용한 설계에서는 line-of-sight 입사가 불가능하여 이온 전류를 분석할 수 없다는 단점이 있으나 표준 가스를 이용한 정량화 등의 큰 장점들이 있다. 최근 이루어진 연구의 내용으로는 유도 결합 플라즈마 장치에서 전도성 메쉬를 이용한 라디칼 거동 관찰을 위해서 두 대의 CPM-300을 메쉬 전 후에 설치하여 라디칼의 양 변화를 전류 프로브와 같이 사용하여 조사하였다.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1624-1626
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• 1997

In this paper, a new PD measurement technique of pulse superposition method was proposed in order to investigate both PD mechanism and phase related PD patterns. From the experimental results, we could find that the polarity and the phase angle of the superposed pulse take great effects on PD characteristics and these method make it possible to get the physical information which statistical approach can not give. We could conclude that the changes of PD characteristics in the void surrounded by polymers may be attributed to the injection of charge carriers thereby formation of space charge in the surface and/or the bulk of the polymer.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.163-166
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• 2001

In this paper, the superposition of ultrasonic signals which were generated by multi-source in a transformer was presented. For analysis of ultrasonic superposition, V$_{peak-peak}$ and pulse number of ultra-sonic signal were used. As a result, the wave form of ultrasonic superposition was classified into three types ; First type was the wave form whose V$_{peak-peak}$ was increased by the superposition of each signal's V$_{peak-peak}$. Second type was wave form whose V$_{peak-peak}$ was decreased by the superposition of each signal's V$_{peak-peak}$. And the other type was wave form whose peals were two or mere. And V$_{peak-peak}$ of superposed ultrasonic wave wads mostlv increased or decreased and pulse number of supe게osed u1trasonic wave was mostly increased.y increased.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.454-455
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• 2008

1970년대 이후 반도체 기술의 발달로 싸이리스트 밸브가 기존의 수은방전밸브를 대체 하면서 HVDC 기술이 급격히 향상되고 교류송전에 비해 직류송전이 갖는 여러 가지 이점 때문에 최근 HVDC 송전이 점점 증가하고 있는 추세에 있다. 본 논문에서는 2000년에 발표된 CIGRE 189.의 "800kV급까지의 HVDC 송전케이블의 전기적 평가 권고안"에 준하여, HVDC해저케이블의 전기적 평가를 위한 극성반전시험 및 임펄스 중첩회로를 해석을 통하여 모의하고 전기적 시험회로의 설계 및 구성한 후 평가한 결과에 대해서 설명한다.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1815-1817
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• 1998

In this paper, a superposed discharge type ozonizer(IESDO) has been designed and manufactured. IESDO is equipped with three electrodes(central, internal and external electrodes), and it is composed of two gaps. Ozone is generated by overlapping silent discharge, which is respectively came from two gaps. This paper describes the following characteristics : (1) The characteristics of discharge with variation of output voltage of AC H.V source, quantity of supplied gas and discharge voltage (2) the characteristics of ozone generation with variation of quantity of supplied gas, discharge power, operating number of IESDO.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1834-1836
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• 2003

In this paper, a superposed discharge type ozonizer(SDO) has been designed and manufactured. SDO is equipped with three electrodes(central, internal and external electrodes), and it is composed of two gaps. Ozone is generated by overlapping silent discharge, which is respectively came from two gaps. At this time, Internal electrode consists of a mesh type. This paper describes the discharge and ozone generation characteristics of SDO with variation of mesh and discharge wattage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.13-18
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• 2014

On 250.199nm uv-line, witch has the potential to emit as a laser line, from a ccrf-excited He-Zn discharge with overlapped DC was carried out optimization of the discharge parameters and measurement of the optical gain. In this study the optical gain of the 250.199nm uv-line has been optained 4% for the first time. At a rf-power of 400W with the frequency 13.56MHz the optimal He-pressure indicated 2kPa.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.99-100
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• 2007

마그네트론 스퍼터링법을 이용하여 $100^{\circ}C$미만의 저온에서 플라스틱 기판위에 IZO(Indium Zinc Oxide) 박막을 증착하였다. 저전압 방전을 위하여 RF 중첩형 DC 마그네트론 스퍼터링 방법을 사용하였으며, 인가 power에 따른 IZO 박막의 전기적, 광학적 특성과 굽힘에 대한 신뢰성을 평가하였다. 플라스틱 기판이 변형되지 않도록 $90\;^{\circ}C$ 이하의 범위에서 기판온도와 산소분압을 변화하여 $2{\times}10^{-4}$ ${\Omega}$ cm의 비저항, 95 % 이상의 가시광 투과도를 가지는 IZO 박막을 증착할 수 있었다. 또한 본 연구에서 비가열의 플라스틱기판 위에 증착한 IZO 투명전극을 이용하여 유연성 OLED를 제작하였으며, 제작된 소자의 특성은 13.7 %의 최대양자 효율과 32.7 lm/W의 전력효율을 보였다.