• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.4
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• pp.211-220
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• 2021

Low-pressure sodium lamps, high-pressure sodium lamps, and fluorescent lamps are mainly used for tunnel lighting in Rep. of Korea, which accounts for the highest percentage in the tunnel maintenance costs. Therefore, tunnel lights are being replaced by LED lamp that have advantages with respect to low power consumption and sustainability. To analyze the effect of replacement high pressure sodium lamp with LED lamp, illumination and monthly power usage per year have been investigated for 10 tunnels. The usage of LED lamp results in illumination improvement from 27.9% to 490% and power saving around average 47.1%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.333-338
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• 2021

This study determined the characteristics of LED illumination and photosynthetically active radiation flux density (PPFD) for LED lighting design in an indoor plant factory. This was done based on the light wavelength and PPFD intensity required for plant growth. It has been found that the wavelength and intensity are decreased according to the measuring distance, and green light has an important role in illumination characteristics, while blue light has an important role in the PPFD characteristics. Considering only the photosynthetic properties of plants, the effective order of photosynthesis was blue>red>white>green. When the measurement distance was 30 [cm], it was found that reduction levels of 60 [cm], 90 [cm], and 120 [cm] decreased to about 36 [%], 18 [%], and 10 [%], respectively. As a result of the characteristics of mixed light (red:blue=2:1, 3:1, 4:1) and the measurement distance, when the measured value at 30 [cm] is 100%, the measured value at 120 [cm] is 10-11 [%]. From the obtained results, an optimal structure was proposed for maximizing the light efficiency of an indoor greenhouse for future research.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1713_1714
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• 2009

본 연구는 LED 광원을 이용한 절전형 라인 조명제어장치의 개발에 관한 것이다. 기본 광원은 5W급 고휘도 LED Lamp를 기본적으로 1~5개의 개별 램프를 제어하며 LED Lamp의 불량상태와 운전상태 감시를 위한 정전류 방식의 구동 기능을 포함하고 여러 단계의 밝기 변화와 절전, 방열을 고려하여 PWM 방식으로 구동 밝기조절 및 점멸 주기 제어기능을 갖는다. 이장치는 도로의 라인조명용 단위장치로 구성될 수 있으며 개별적으로 중앙통제시스템과 통신제어기능을 수행할 수 있게 구성된 시스템이다.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.673-679
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• 2012

This study was conducted to examine the effect of artificial light source and photoperiod on the growth of leaf lettuce (Lactuca sativa L.) 'Seonhong Jeokchukmyeon' in a closed-type plant production system. Seedlings were grown under 3 light sources, fluorescent lamp (FL, Philips Co. Ltd., the Netherlands), WL #1 (Hepas Co. Ltd., Korea), and WL #2 (FC Poibe Co., Ltd., Korea), each with 3 photoperiods, 12/12, 18/6, and 24/0 (Light/Dark). An irradiance spectrum analysis showed that FL has various peaks in the 400-700 nm range, while WL #1 and WL #2 have only one monochromatic peak at 450 and 550 nm, respectively. The greatest plant height, fresh and dry weights were obtained in the 24/0 (Light/Dark) photoperiod. The 24/0 (Light/Dark) photoperiod treatment promoted vegetative growth of the leaf area. Length of the longest root, number of leaves, fresh weight, and total anthocyanin contents were greater in FL than in either WL #1 or #2. The greatest chlorophyll fluorescence (Fv/Fm) was found in the 12/12 (Light/Dark) photoperiod with FL treatment. The energy use efficiency of the LED increased by about 35-46% as compared to FL. Results suggest a possibility of LED being used as a substitute light source for fluorescent lamp for lettuce cultivation in a plant factory system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.55-58
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• 2004

Recently the examples of a lighting design with LED source have increased rapidly, but there are few researches that are related to selecting luminous colors by LED. The research is that respondents operated color blender and got preference colors according to what they made, the colors were measured by chroma meter and marking CIE 1931 chromaticity diagram. Through the results of the research has made group preference for luminous colors. From now on, not only does it seem capable of using a designing a building-lighting to which LED but it will be actively applied to controlling with a digital technology for lighting design.

• Fire Science and Engineering
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• v.16 no.2
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• pp.1-7
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• 2002

In the normally, exit sign is always lighting on status by the connected to normal electrical source. So, there are happened to rise of the economical cost such as power consumption, maintenances and repair replacement of lamp etc. This paper are study on the new exit sign circuits by using high efficiency LED that is available for remote control and reduceible to power consumption, maintenance cost by the way of compensation fluorescent and incandescent lamps. As a results on the study, exit sign lamp is capable of control and supervisory in trigger angle by the remote control switch, widely and easily. And then, the response time was very fast in 600〔$\mu$s〕and also it can be find that the rising and fall time of oscillate circuit is maximum 200〔ns〕 as high sensitively. Finally, it obtain to the result that reducible of electrical power consumption and not required for replacement of lamp by using the high efficiency LED lighting source.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.92-93
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• 2017

최근 IT 및 사이니지 기술을 포함한 여러 기술의 발전 형태가 융복합적 기술의 방향으로 전환됨으로서, 기술 간 장벽이 허물어지고, 상호 연관성을 갖게 됨에 따라 사이니지 및 IT기술이 접목된 새로운 융복합 기술에 대한 연구가 지속적으로 이루어지고 있다. 특히, LED 광원의 일종인 사이니지를 이용하여 광 데이터를 전송할 수 있는 기술에 대한 연구가 학계, 연구소 및 관련 산업체 등에서 지속적으로 진행되고 있는 상황이다. 이에 본 논문에서는 LED 전광판 사이니지를 이용하여 무선광통신이 용이한 LED 소재에 대한 연구를 진행하였다. LED 전광판 사이니지를 이용한 무선광통신 기술은 LED 광원이 지닌 특성을 토대로 RF방식 대비 높은 주파수 대역과 고속의 데이터 전송이 가능하기 때문에 높은 잠재력과 파급력을 통하여 무선통신 분야에서의 새로운 통신 척도로 활용될 수 있을 것으로 예상된다.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.81-83
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• 2005

반도체 기술의 발전으로 기존에 전자회로 부품으로 사용되던 LED(Light Emitting Diode)는 차세대 조명용 광원으로 대두되고 있다. LED는 소비전력이 작아 에너지를 절약할 수 있을 뿐만 아니라 수명이 길어 유지보수 비용이 획기적으로 줄어든다. 현재 신호등과 같은 지시용 조명기기를 대체할 광원으로 다양한 시도가 이루어지고 있다. LED는 자체적인 발열은 적지만 주변온도에 민감하게 광도가 변화한다는 단점을 가지고 있다. 높은 온도는 LED의 수명에도 영향을 미쳐 열화를 빨리 가져오게 된다. 따라서 정전류제어를 통해 LED의 전류를 일정하게 하고 온도변화에 영향을 받지 않고 광도를 일정하게 유지하여야 한다. 본 논문에서는 정전류 구동회로에 열화로 인한 LED의 수명의 연장하기 위해 온도변화에 따라 LED의 구동전류와 일정한 광출력을 유지하기 위한 제어회로를 제안하였다. 제안한 제어회로는 시뮬레이션을 통해 타당성을 검증하였다.

• Photonics industry news
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• s.35
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• pp.10-13
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• 2006

발광다이오드(LED)산업은 21세기 빛의 산업으로 세계시장에서 매우 유망한 산업의 하나이며, 국가성장을 위한 미래전략산업의 하나다.LED라는 것은 반도체에 전압을 가할 때 생기는 발광현상으로 빛을 내는 조명방식인데 기존의 조명과는 달리 무한대의 색과 높은 휘도를 낼 수 있다. 아울러 고유 가시대에 에너지 절감과 환경보호효과가 커서 새로운 차세대 광원으로 떠오르고 있다.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.223-233
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• 2014

Cyanidation method has been used to extract high-purity gold and silver in mining industry. Such mining activities have used a large amount of cyanide, and the mine wastewater contained a high level of cyanide has brought about pollution of surrounding aqueous environments. This research was initiated to study $TiO_2$-catalytic UV-LED photo-oxidation to remove cyanide from the mine wastewater. UV lamp has been generally used as a light source in conventional photo-oxidation so far, but it shows numerous drawbacks. For this reason, this study focused on the evaluation of applicability of UV-LED as an alternative light source in cyanide photo-oxidation process. Three types of $TiO_2$ photo-catalyst were compared in terms of performance of photo-oxidation of cyanide, and the results show that Degussa P25 was the most efficient. In addition, four types of UV-LED were tested to compare their efficiencies of cyanide photo-oxidation, and their efficacy was increased in the order of 365 nm lamp-type > 365 nm can-type > 280 nm can-type > 420 nm lamp-type. Not only did this study demonstrate that UV-LED can be used in the photo-oxidation of cyanide as an alternative light source of UV lamp, but also confirmed that the performance of photo-oxidation was significantly influenced by the type of $TiO_2$ catalysts.