• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1045-1052
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• 2011

Recently, because of complex cultural space, underground space are becoming larger. Therefore, the demand for location-based services is growing. VLC (Visible Light Communication) is based on the LED lighting infrastructure so that suitable LBS (Location-based service) is possible for the targeted places in indoor space. To experiment with indoor LBS by VLC, we measure the identification distance according to variable angles between LED and photo diode. We send the different ASCII code for each LED light, then we found the maximum identification distance is 1.75m from LED lights. From the results of this experiment, we show that indoor navigation is possible.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.201-203
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• 2009

본 논문에서는 LED(light emitting diode)를 사용한 일반 조명에서부터 자동차 조명에 대한 LED, CNT(carbon nano-tube), OLED조명의 융합기술 현황에 대하여 살펴보았다. 정부의 15/30보급정책의 일환인 LED조명 시범보급사업(부산 및 대전 지하철역사, 김대중 컨벤션센터, 대구 및 대전 우체국 등)과 한국산업규격(KS C 7651-3)의 제정 등으로 LED 응용 조명은 시장에서의 사용으로 기존 조명기기와의 경쟁력이 예상된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2317-2322
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• 2010

Market for LED lights as a newly-growing industry has been growing, and secureness of high efficiency and long life through optimal thermal design are crucial for further popularization. In this study, considerable improvement in thermal performance for a 10W LED light has been done compared to a previous model. For this, numerical model has been established through experiments and used to optimize design factors in heat release such as fin shape, PCB kind or LED number etc. Furthermore, prototype of a LED light has been made and the improved thermal performance was verified with heat release experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.938-941
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• 2012

LED is divided to multichannel in order not to exceed a certain voltage in aspects of electric standard. However, it's not possible to know in accordance with what channel SMPS controls the constant voltage and current. In order to solve this problem, it needs to detect the maximum LED String voltage which is applied to LED control circuit, and it is possible to minimize the voltage drop when a difference of LED string voltage occurs by each channel if LED is controlled by the maximum LED string voltage detected. In addition, it is also possible to maximize the efficiency of LED if change LED voltage by detecting the maximum voltage. Feasibility of this claim was verified through implementation of the circuit.

• Korean Journal of Optics and Photonics
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• v.21 no.3
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• pp.118-122
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• 2010

We fabricated a high power LED lamp structure which utilizes the modified COB concept based on an MCPCB with insulation layer partially removed. In the proposed structure, no insulation layer exists between the LED chip and the metal base. As a result, the heat generated in the chip is easily dissipated through the metal base. In actual measurement as well as in thermal simulation, the fabricated LED lamp structure showed superb thermal properties, compared to the SMD LED lamp attached on an MCPCB or the LED lamp based on conventional COB concept.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.559-560
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• 2009

네트워크를 이용한 LED 조명의 제어는 최근 IP(Internet Protocol)을 이용한 조명 제어와 융합되어 단순한 디밍(Dimming)제어 뿐만 아니라, 미디어 파사드(Media facade), 카이네틱 아트(Kinetic Art)등의 새로운 조명 분야로 범위가 확대 되고 있다. 본 논문에서는 다양화 되는 네트워크 기반의 제어 방식 중 DMX over IP 에 대하여 멀티케스트-다중화 방식(Multicast & Multiplexing)으로 분석 및 시뮬레이션 하였다. 그 결과 1 만개 이상의 채널 수를 가지는 규모가 큰(large volume) 조명 네트워크 시스템의 경우 채널의 개수 증가가 delay-throughput 에 영향이 적음을 알 수 있다.

• Resources Recycling
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• v.33 no.1
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• pp.3-14
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• 2024

Owing to technological advancements and energy-saving policies, the demand for LED is increasing, leading to rapid industry expansion. Consequently, efficient recycling of accumulated LED waste has become a growing social concern, and current recycling status of LED waste resources and future directions were reviewed. Currently, waste LED recycling is focused on Ga recovery. Therefore, the development of integrated recycling technologies such as pre-treatment and concentration/recovery of high valued materials is necessary. In this study, we investigated the status and recycling technologies of waste LED and presented prospects.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.208-214
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• 2017

This study aimed to determinate the effect of fluorescent light and light-emitting diodes on the leaf morphology, growth and antioxidant capacity of Salvia plebeia. The plants were grown for 56 days after transplanting (DAT) under the fluorescent light (FL) and LEDs (White, Red and Blue (R+B, ratio 2:1), Blue, Red LED) under the same light intensity and photoperiod ($130{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 hours). Leaf length, width and number of Salvia plebeia at the 56 DAT were significantly higher under the FL and red LED, and lower in the RB LED and white LED. The highest fresh and dry weights of shoot and leaf area were observed in the red LED, followed by the FL and blue LED, and the lowest in the RB LED and white LED. After 21 DAT, leaf apinasty symptom was appeared in plants grown under red LED and RB LED. The chlorophyll content was lower in the red LED. The specific leaf weight, the ratio of leaf dry weight to area, was higher in the blue LED, and lowest in the FL. No significant difference in DPPH radical scavenging activity of Salvia plebeia under the different light sources. All the integrated results suggest that the FL light is a proper light conditions for a closed cultivation of Salvia plebeia.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.203-206
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• 2016

This study was conducted to evaluate the attraction effects of Sitotroga cerealella and Plodia interpunctella adults to light emitting diode (LED) trap in granary and compared with the results of the black light bulb (BLB) trap, which is typically used as a commercial trap. The blue LED was more attractive to S. cerealella than the BLB. The green LED was significantly more attractive to P. interpunctella than the BLB. Furthermore, the external installation of blue LED and green LED was about 1.7 times more attractive to S. cerealella and P. interpunctella, respectively, than the internal installation. These results indicated that blue LED and green LED traps can be used for eco-friendly insect pest control in granary.

• Journal of Mushroom
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• v.12 no.4
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• pp.375-378
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• 2014

The attractions of Lycoriella ingenua to different LED light sources were investigated in the mushroom cultivations which were located in Yongin of Gyeonggi-do province and Buyeo of Chungcheongnam-do Province. The LED light sources which were used in the investigations were white, green, red, blue and orange. Numbers of Lycoriella ingenua to LED lights in Yongin and Buyeo were 132.9 and 3,272.5 to white LED source, 120.3 and 3,109.5 to green LED source, 105.5 and 1,910.1 to red LED source, 88.3 and 2,708.3 to blue LED source and 46.7 and 2,465.5 to orange LED source, respectively. The numbers of Lycoriella ingenua to LED light sources were 2.7~3.5 times higher than the ones of untreated.