• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.2050-2055
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• 2009

This paper describes the proceeding experimental results to replace the 32 [W] fluorescent lamp installed in subway train to a LED module. We fabricated 25 [W] LED modules to meet the illuminance 300 [lx] specified in the standard for subway train. After the installation of LED modules, comparative analysis with conventional fluorescent lamps was carried out. From the experimental results, illuminances on the height of 0.85 [m] and 1 [m] above floor were 323 [lx] and 360 [lx], respectively. These illuminances satisfied the requirement 300 [lx]. By the application of 25 [W] LED module as a light source in subway train, energy saving about 22 [%] compared with 32 [W] fluorescent is acquired. Also, low cost of maintenance is expected due to 8 times longer lifetime 50,000 hours of LED than that 6,000 hours of fluorescent lamp.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.315-316
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• 2015

LED 광원용 해상용 등명기의 동향을 조사해 보았으며, 최근 수요가 증가하고 있는 LED-300 등명기의 특성을 업체별 색상별로 통계화하여 부동광도 특성 및 소비전력 특성의 차이점 등을 분석했다. 이를 통해 현단계의 문제점 및 개선 방향에 대해 언급하였다.

• 한국전자통신학회논문지
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• 제10권1호
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• pp.111-116
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• 2015

본 연구에서는 실내조명을 위한 LED 조명용 정전류 컨버터를 설계하고 제작된 SMPS의 전기적 특성을 측정하였다. 출력전류가 300mA 일 때 최대 85%의 효율을 나타내었으며 100~400mA의 범위에서는 70% 이상의 효율을 나타내었다. 또한 0~250mV의 제어신호를 이용하여 디밍레벨 0~100%의 범위를 모두 제어할 수 있었다.

• 한국전기전자재료학회논문지
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• 제28권2호
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• pp.131-136
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• 2015

We develop the 60 W class hybrid solar LED street lamp controller. The controller is providing power via an inverter in the day with the least solar cell and battery and charging the battery for the ESS, acts as a power failure, the built-in battery. Rated output of the fabricated LED street lamp is 300 W or greater battery capacity 300 Wh, discharge time 10 hr, LED street lamp efficiency showed a very high level of light efficiency by about 127 lm/W. In addition, as a result of light distribution pattern according to the distance and the light intensity measurement will be able to ensure a very high quality, show the constant brightness in the distance from the road lights 6 m is about 35~40 lux in uniformity ratio. The proposed hybrid solar LED street lamp system showed a high energy capacity of approximately 1.5 to 152.7% power generation efficiency than typical conventional solar street lamp.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2011년도 제43차 동계학술발표논문집 19권1호
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• pp.299-300
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• 2011

태양에너지를 에너지 공급원으로 하고 LED 램프를 조명용 광원으로 사용하여 적은 전력 소모와 연장된 램프의 수명으로 에너지 소모를 크게 줄이고, 유지 보수 관리 비용을 획기적으로 줄일 수 있는 LED 조명제어시스템을 개발하였다. 점등 회로, 구동회로 등의 최적화된 설계와 구성으로 광 변환 효율을 높여 소형화, 경량화 되도록 하고, 환경 친화적인 조명 광원으로서 효율적인 성능을 얻을 수 있도록 한다.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 동계학술발표회 논문집
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• pp.299-300
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• 2007

• 한국재료학회지
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• 제19권8호
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• pp.417-420
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• 2009

This study develops a highly transparent ohmic contact using phosphorus doped ZnO with current spreading for p-GaN to increase the optical output power of nitride-based light-emitting diodes (LEDs). The phosphorus doped ZnO transparent ohmic contact layer was prepared by radio frequency magnetron sputtering with post-deposition annealing. The transmittance of the phosphorus doped ZnO exceeds 90% in the region of 440 nm to 500 nm. The specific contact resistance of the phosphorus doped ZnO on p-GaN was determined to be $7.82{\times}10^{-3}{\Omega}{\cdot}cm^2$ after annealing at $700^{\circ}C$. GaN LED chips with dimensions of $300\times300{\mu}m$ fabricated with the phosphorus doped ZnO transparent ohmic contact were developed and produced a 2.7 V increase in forward voltage under a nominal forward current of 20 mA compared to GaN LED with Ni/Au Ohmic contact. However, the output power increased by 25% at the injection current of 20 mA compared to GaN LED with the Ni/Au contact scheme.

• 대한금속재료학회지
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• 제50권1호
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• pp.71-77
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• 2012

We studied the effect of heat treatment on the microstructures and mechanical strength of the solder joints in the Light Emitting Diode (LED) packages. The commercial LED packages were mounted on the a flame resistance-4 (FR4) Printed Circuit Board (PCB) in the reflow process, and then the joints were aged at $125^{\circ}C$ for 100, 200, 300, 500 and 1000 hours, respectively. After the heat treatment, we measured the shear strength of the solder joints between the PCB and the LED packages to evaluate their mechanical property. We used Pb-free Sn-3.0Ag-0.5Cu solder to bond between the LED packages and the PCBs using two different surface finishes, Electroless Nickel-Immersion Gold (ENIG) and Electroless Nickel-Electroless Palladium-Immersion Gold (ENEPIG). The microstructure of the solder joints was observed by a scanning electron microscope (SEM). (Cu,Ni)6Sn5 intermetallic compounds (IMCs) formed between the solder and the PCB, and the thickness of the IMCs was increased with increasing aging time. The shear strength for the ENIG finished LED package increased until aging for 300 h and then decreased with increasing aging time. On the other hand, in the case of an ENEPIG finished LED package, the shear strength decreased after aging for 500 h.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.522-523
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• 2008

This paper presents an LED lighting which can control its color temperature. It consists of a power factor correction (PFC) circuit, an LED driver, and an LED color control circuit. The proposed system can adjusts the light intensity to obtain a desired color with independently changeable illuminance. The power factor of the PFC circuit is 98%. The LED driver has 90% efficiency at 300mA output current. The output power of the experimented LED lighting is 150 W. The achieved color temperature range was from 3000K to 7500K, and the illumination one was from 500 lux to 1500 lux.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.375-376
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• 2007

In this work, we have simulated a 42-inch LED BLU which was based on 300 RGB LEDs. We have done an adjustment of LEDs' strip distance and a height of the top of the LED to the back of the LCD to get white color uniformity. So, we have changed simultaneously the distance between the top of the LEDs and the back of the LCD. Moreover, we set a fixed position for the horizontal of LED's pitch. And then, we have experimented and compared to our simulation data.