• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기설비전문위원
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• pp.97-100
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• 2004

HFPD(High Frequency Partial Discharge) measurement has been widely performed to diagnosis of cable system in the world although Korea just begin. The efficiency of measurement has been reported and proved by many researchers who are engaged in the diagnosis of high power apparatus. LG Cable has investigated the technology of diagnosis for cable system by means of PD measurement for 10 years. In this paper, PD measurement with portable device was performed to evaluate the quality of the 154kV transmission line and the 22.9kV XLPE cable line. Test results are shown that the HFPD detection technology is very attractive for the diagnosis of power cable system by high detection sensitivity at on-site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.649-652
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• 1992

ECR(Electron Cyclotron Resonance) occure at ${\omega}_c$=${\omega}$, ${\omega}_c$:electron cycltron frequency, ${\omega}$:electromagnetic wave frequency. ECR system have several merit, 1) power transefer efficiency 2) low neutral gas pressure (below 1 mTorr) 3) high plasma density($10^{12}$ $cm^{-3}$). It is applicated variously in the field of semiconductor and new materials as the manufacturing equipment. Magnetic field in ECR system contruct resonance layer (${\omega}$=2.45GHz, $B_z$=875 Gauss) and control plasma. Plasma is almost generated at resonance layer. If the distance between substrate and resonance layer is short, uniformity of plasma is related with profile of resonance layer. Plasma have the property "Cold in Field", so directonality of magnetic field is one of the control factors of anisotropic etching. In this study, we calculate B field and flux line distribution, optimize geometry and submagnet current and improve of magnetic field directionality (99.9%) near substrate. For the purpose of calculation, vector potential A(r,z) and magnetic field B(r,z), green function and numerical integration is used. Object function for submagnet optimization is magnetic field directionality on the substrate and Powell method is used as optimization skim.

• 한국전기전자재료학회논문지
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• 제16권4호
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• pp.351-357
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• 2003

An easy learning elevator originated is opened to compare the existed teaming equipment, and it had a high studied efficiency that the sequence control circuit can open and close with the wire. The structure of equipment to be controlled from the first floor to the fifth floors is demostrated by the constructive apparatus with the lamps to express the function of the open-close of the door according to the cage moving with a mechanical actuation of the forward reverse breaker and the motor of load, and the mechanical actuation of hand-operation control components of push-button S/W and L/S and relay etc. These components let connect each other in order to control of the elevator function with the auto program and the designed sequence control circuit. Consequently the cage could go and come till 1∼5 steps with an auto program of the elevator and the sequence control circuit. The sequence control circuit is controlled by the step of forward and reverse to follow as that the sensor function of L/S1 ∼ L/S5 let posit with the control switchs of S/W1 ∼ S/W5 of PLC testing panel and switchs of S/W1 ∼ S/W5 installed on the transparent acryl plate of the frame. In here, improved apparatus is the hand-auto operation combined learning equipment to study the principle and technique of the originate sequence control circuit and the auto program of PLC.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.50-59
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• 2003

It was known that high pressure injection is an effective method to enhance thermal efficiency and decrease exhaust emissions in diesel engines. If injection pressure becomes ultra high, it is predicted that there may be a suitable injection pressure which the enhancement rate of spray characteristics is moderate. Also, there may be a limit injection pressure which spray characteristics is reversed and get worse. But these are unknown. To investigate a suitable injection pressure and a limit injection pressure, ultra high pressure injection equipment(UHPIE), which can realize the injection pressure of 3,200bar, was developed. UHPIE is a basic apparatus of single shot injection, and ultra high pressure was achieved by second stage rapid compression in short time. From the evaluation of UHPIE, a injection curve like a conventional diesel engine(jerk type) was realized. Also, it was proved that repetition of experiment was excellent. Therefore it was found that there was no problem to perform the study on the ultra high pressure injection with UHPIE. Consequently, the foundation of the study on ultra high pressure injection could be established.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.39-44
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• 2009

Entering in the time of high oil price, seriousness of an energy effect sector has given a huge impact and the importance of energy is growing. Especially, building energy occupying 24% of total demand of energy is expected to be possible to reduce energy demand more than other section. To reduce the building energy consumption, this study analyzes function and thermal performance of Super window by heat experimental apparatus. Super window is a 2-track low-e glazing window for high insulation efficiency. By applying the results of this experiment to building energy efficience rating tool, this study compares energy efficiency rates depending on a region.-Jeju, South, Central. And it shows how much does Super window reduce Building energy consumption.

• 한국지반신소재학회논문집
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• 제10권4호
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• pp.93-103
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• 2011

극한지에 적합한 지반구조물의 설계를 위해서는 일반적으로 영구동토지반의 공학적 특성에 대한 고려가 필요하다. 동상현상은 가장 대표적인 동토지반의 공학적 특성으로, 구조물 설계에 있어서 동착 및 크리프 현상과 함께 주요한 설계정수로서 고려된다. 그러므로 극한지 지반구조물 설계에 관한 연구를 위해서는 동상현상에 대한 기초적 연구가 선행되어야 한다. 이미 다양한 동상 관련 실험장비가 개발되어 연구에 활용되고 있지만, 기존의 동상 연구를 위한 실험장비들은 기초의 설계정수로서 동상현상을 분석하기에는 한계점이 나타난다고 판단된다. 따라서 본 논문에서는 동상현상을 비롯하여 토사의 동결현상을 보다 면밀히 분석할 수 있도록 개발된 실내 동결 실험장비를 소개하고, 장비의 활용성을 검증하기 위한 실내실험 결과를 제시한다. 검증 실험결과로부터, 개발된 고효율 동결실험장비의 다양한 동결현상 모사성능과 동상시험에의 활용 가능성을 검증하였다.

• 전기학회논문지
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• 제56권7호
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• pp.1261-1267
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• 2007

Although LEDs have been used in various applications with improving the brightness and luminous efficacy, the electrical and optical characteristics of high power LED varies at different temperature and starting time. In this paper, optimal heat sink and apparatus design were conducted using IR camera and ICEPAK on the LED bulb consisting with fourteen LED array. The temperatures of heat sink and LED device of the designed LED bulb without cooling pan were $74^{\circ}C\;and\;96.8^{\circ}C$, respectively, showing in good themal characteristics. For high efficiency driving circuit of LED array adopted optimal heat sink design, driving circuits of constant voltage and current circuits were suggested and fabricated. As a result the efficacy of all driving circuits showed more than 20 lm/W. Also, the constant current circuits are suitable for signal lamp, hallway lamp, and flash lamp having short operating time(about 30 min). On the other hand, a reading light and indoor lamp having long operating time can be controlled by constant voltage circuit.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.187-190
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• 2007

Nowadays, with urban railway vehicles, refrigeration has been used for a long time as an air conditioner including a heating apparatus and a ventilator. Regarding saveenergy, there are lots of researches continually on the refrigeration field to reduce the parts' weight, improve the parts' efficiency and make good looking design of air conditioners. Moreover, we are able to see the recent achievement of the researches. As a result, through this research we improve the quality of inner air with the urban railway system and make a domestic HVAC system by technical development of high capacity air conditioner and the principal parts.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.218-221
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• 2007

Nowadays, with urban railway vehicles, refrigeration has been used for a long time as an air conditioner including a heating apparatus and a ventilator. Regarding saveenergy, there are lots of researches continually on the refrigeration field to reduce the parts' weight, improve the parts' efficiency and make good looking design of air conditioners. Moreover, we are able to see the recent achievement of the researches. As a result, through this research we will improve the quality of inner air with the urban railway system and make a domestic HVAC system by technical development of high capacity air conditioner and the principal parts.

• 한국정보전자통신기술학회논문지
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• 제9권2호
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• pp.185-189
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• 2016

에너지 절약형 전열제품 개발은 유가상승에 따라 국가의 최대 현안으로 꼽히고 있다. 따라서 최근에는 이러한 문제점들을 대처하기 위해 전기를 이용한 난방장치에 대한 에너지의 효율적 사용측면에서 경제성과 안정성을 높이기 위한 지속적인 연구 연구개발이 이루어지고 있고, 특히 고성능 및 신기능 소재에 대한 기술개발이 활발히 이루어지고 있다. 본 논문은 에너지 전달특성이 우수한 전열제품 개발에 관한 것으로 고효율 유도가열 장치에 관한 연구이다. 유도가열은 전자유도현상을 이용한 것으로 기존의 전도나 대류와 같은 열전달 방식과는 전혀 다르게 중간매질이 없이 피가열물에 직접 흡수되어 열로 전환되므로 급속, 균일하게 가열시키는 특징을 가진다. 또한 고주파 유도가열은 다양한 구조 설계가 가능하므로 가열 발열체를 적절히 활용하면 피가열물만을 집중가열 하는 것이 가능하다.