• 농업과학연구
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• 제40권4호
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• pp.297-303
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• 2013

This study was carried out to examine the effect of Red LED (660 nm) and fluorescent lamp for night break (NB) treatments of each 3 hours (22:30-01:30), 4 hours (22:00-02:00) and 5 hours (21:30-:02:30) per day for 53 days on flower bud initiation and growth in Chrysanthemum cv. 'Baekma' and cv. 'Jinba'. The days to flower budding after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (21.0 days) and 5 hr (20.5 days) NB, and it was shorter at Red LED 3 hr (14.2 days). The days to flowering after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (54.0 days), 5 hr (53.5 days) NB, and Red LED 5 hr (53.3 days), and it was shortest at Red LED 3 hr (50.2 days) NB treatment among all treatments. The days to flower budding after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (20.6 days) and was shorter at Red LED 3 hr (14.1 days) among all treatments. Similarly, the days to flowering after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (55.3 days) and was shortest at Red LED 3 hr (50.2 days) among all treatments. Therefore, inhibition of flower bud initiation was the most effective under fluorescent lamp 4 hr treatment. The length of cut flower of 'Baekma' was increased by fluorescent lamp 4 hr, 5 hr, and Red LED 5 hr, but of 'Jinba' was longer at LED 4 hr and 5 hr treatment. The weight of cut flower of 'Baekma' was heaviest at fluorescent lamp 5 hr treatment and was at Red LED 5hr treatment for 'Jinba' even though there was not statistically significant difference between 'Baekma' and 'Jinba'. Consequently, under fluorescent lamp 4 hr for night break was the most effective on flower bud initiation, flowering inhibition and cut-flower characteristics in 'Baekma' and 'Jinba'.

• 한국융합학회논문지
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• 제8권3호
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• pp.199-204
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• 2017

최근, 자동차 전조등에 할로겐 램프가 아닌 LED 전조등을 사용하고 있는 추세이다. 이 LED 전조등 내부에는 방열판이 존재한다. 방열판은 LED 수명에 지대한 역할을 하는 중요한 부품이다. 방열판은 매개물로부터 나온 열을 흡수하여 다이오드의 오버히트를 방지하는 장치이다. 본 연구에서는 LED 전조등 방열판의 형상에 따른 열전달과 열응력에 대하여 알아보았다. 본 연구 결과로서, Model 1이 Model 2에 비해 열이 더 많이 내려가고 내구성면에서도 좋은 값이 나와 내구성이 더 있었다. 이러한 기반데이터로 방열판 형상에 융합기술 적용하여 자동차 전조등에 그 미적 감각을 나타낼 수 있다.

• 한국터널지하공간학회 논문집
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• 제23권4호
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• pp.211-220
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• 2021

터널구조물의 특성상 터널조명은 일반 도로의 조명과 달리 주간에도 조명이 필요하므로, 터널 유지관리 비용 가운데 터널조명을 위한 전력요금은 가장 높은 비율을 차지하고 있는 것으로 알려져 있다. 따라서 유지비용 절감 등을 위하여 터널조명을 낮은 소비전력, 장수명 등의 장점이 있는 LED램프로 교체 중에 있다. 본 연구에서는 기존 터널조명이 고압나트륨램프인 10개소 터널을 대상으로 터널조명 광원을 LED램프로 교체 시 효과 분석을 위하여, 광원 교체 전·후 터널 조도측정결과 및 1년간의 월별 전력사용량을 조사하였다. 터널조명 광원을 고압나트륨램프에서 LED램프로 교체 후 조도는 27.9~490% 향상되었으나, 터널조명용 전력사용량은 평균 47.1% 감소한 것으로 나타났다.

• 한국의류산업학회지
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• 제20권1호
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• pp.101-107
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• 2018

The purpose of this study is to develop the electroconductive textiles based on polyurethane(PU) nanoweb and to explore that it is applicable to smart clothing. The electroconductive textiles developed by coating 2.0 wt% aqueous dispersed non-oxidized graphene paste on the surface of PU nanoweb. The fabricated electroconductive nanoweb was applied as a transmission line to connect the LED lamp, and the brightness of the LED lamp was measured to confirm its performance. The nanoweb transmission line was fixed by two methods(seam sealing tape, embroidering) to connect the LED lamp and AA batteries. The results as follows, the brightness of the LED lamp fixed with seam sealing tape was about 82 lux, and which fixed with embroidering was about 57 lux. It represents that the nanoweb transmission line which fixed with the seam sealing tape has better electrical signal transmitting because the lux value higher than the one fixed by embroidering. In order to compare the performance of the nanoweb transmission line and the metal wire, we connected the LED lamp with copper wire. The brightness of copper wire connected LED lamp was about 193 lux. Although the electrical signal strength of the nanoweb transmission line was weaker than the copper wire, it was reachable to operate LED lamp. The results of this study will provide a basic data to develop the textile based electronic devices, and conducting wire for smart clothing.

• 조명전기설비학회논문지
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• 제24권10호
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• pp.13-20
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• 2010

Until now, dimmable fluorescent luminaires has been widely used for dimming systems, and LED is currently attracting attentions as a alternative lamp due to environmental problem issues. LED, one of eco-friendly high efficiency lamp, has advantage that dimming is easy than fluorescent luminaire. But there have been not enough research on technical development and application for LED dimming. Therefore, to analyze luminous quantity of dimmable LED, the illuminance, color temperature, luminance, and current were measured in the whole range of dimming. In the results of this study, the dimmable LED of various types showed a similar trend in the changed luminous quantity by dimming.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.266-267
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• 2004

LED를 이용한 차량용 signal lamp를 구현 하였다. 가변적인 전원전압 및 온도조건에서도 일정한 광량을 유지할 수 있도록 하였으며, 한편 단위 LED 사이의 특성 차이로 인한 밝기의 불균일성을 줄일 수 있도록 하기 위하여 펄스폭 변조를 응용한 회로를 적용하였다.

• Journal of Biosystems Engineering
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• 제37권5호
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• pp.314-318
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• 2012

Purpose: This study was conducted to develop a measurement system for determining photosynthetic photon flux (PPF) distribution and illumination efficiency of LED lamps. Methods: The system was composed of a linear moving sensor part (LMSP), a rotating part to turn the LMSP, a body assembly to support the rotating part, and a motor controller. The average PPF of the LED lamp with natural cooling and water cooling was evaluated using the measurement system. Results: The PPF of LED lamp with water cooling was 3.1-31.7% greater than that with natural cooling. Based on the measured value, PPF on the horizontal surface was predicted. Illumination efficiency of the LED lamp was slightly increased with water cooling by 3.4%, compared with natural cooling. A simulation program using MATLAB was developed to analyze the effects of the vertical distance from lighting sources to growing bed, lamp spacing, and number of LED lamps, on the PPF distribution on the horizontal surface. The uniformity of the PPF distribution of the LED lamps was fairly improved with 15 cm spacing, as compared to the 5 cm spacing. By simulation, PPF of $217.0{\pm}27.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was obtained at the vertical distance of 40 cm from six LED lamps with 12 cm spacing. This simulated PPF was compared to the measured one of $225.9{\pm}25.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. After continuous lighting of 346 days, the relative PPF of LED lamps with water cooling and natural cooling was decreased by 6.6% and 22.8%, respectively. Conclusions: From these results, it was concluded that the measurement system developed in this study was useful for determining PPF and illumination efficiency of artificial lighting sources including LED lamp.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.196-198
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• 2008

본 논문에서는 LED의 고출력화가 이루어지면서 많이 사용되고 있는 LED MR 타입과 PAR 타입의 램프 배광을 설계하였다. 1W와 5W급의 High power LED를 적용하였고, 1개의 LED가 사용된 빔각 30도의 MR16 램프부터 9개의 LED가 사용된 빔각 60도의 PAR30 램프까지 총 6가지 배광을 구현하고 최대광도로 각각의 성능을 평가하였다. 빔 각을 구현하고 집광시키기 위하여 LED dome 측면부에 소형의 반사판을 설계하였다.

• 조명전기설비학회논문지
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• 제25권1호
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• pp.1-8
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• 2011

In this paper, the method to calculate chromaticity coordinate from spectral power distribution of LED is presented. Also, inverse tri-stimulus algorithm to find mixed luminance of red, green, blue LED from targeted luminance and chromaticity coordinate is proposed. Besides, digital light color control system of LED lamp applied this algorithm has been developed. In experiments, each chromaticity coordinate of red, green, blue LED calculated from this algorithm has relative percentage error of few % to measured values. Digital code is drawn from inverse tri-stimulus algorithm, and measured values of luminance and chromaticity coordinate of LED lamp digitally controlled by this code also have relative percentage error within a few % to targeted luminance and chromaticity coordinate.

• 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.