• 센서학회지
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• 제24권4호
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• pp.232-238
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• 2015

In this paper, we introduce a passive transponder in which an LED is used for both a light transmitter and a receiver, and a solar cell is used for supplying power to the all devices in the transponder. The LED in the transponder operates as a photodetector in the receiving mode, and acts as a light source in the transmitting mode. The current responsivity of the LED detector was measured to be in the order of $10^{-4}A/W$, and the receiving bandwidth with a load resistance of $10k{\Omega}$ was about 10 to 30 kHz. Using the LED for an optical transceiver in a VLID transponder, the detection range was about 70 cm when the transponder was illuminated by the visible light from a $3{\times}3$ LED array in a reader.

• 한국약용작물학회지
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• 제28권3호
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• pp.200-208
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• 2020

Background: Salvia miltiorrhiza Bunge has been used in traditional medicine. The type of light source has an effect on the growth properties and composition of functional compounds in plants. In this study, we analyzed the effects of different artificial light sources on the growth characteristics as well as antioxidant and antimicrobial activities of S. miltiorrhiza. Methods and Results: Seedlings of S. miltiorrhiza were grown under various artificial light sources, including fluorescent light (FL), light emitting diode (LED), and microwave electrodeless light (MEL), for 8 weeks. Growth characteristics were the best in plants treated with MEL. DPPH scavenging activity of the shoot was more pronounced with the FL treatments, while the roots were more active in plants grown under single wavelength lights (i.e., blue and red LEDs). Among the different light source treatments, the blue LED resulted in a higher total phenolic content in the plants. Furthermore, growing plants growth under the red LED enhanced their total flavonoid content. Notably, the antimicrobial properties of plants varied significantly between light source treatments in this study. Except for E. coli, all the tested microorganisms were susceptible to the plant extracts. Conclusions: The type of light source may be an important parameter for the enhancement of plant growth and functional compounds in S. miltiorrhiza.

• 농업과학연구
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• 제44권2호
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• pp.261-271
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• 2017

The aim of this study was to investigate the amount of glucosinolates (GSLs) in kale sprouts (Brassica oleracea L. var. acephala) ('TBC') according to different concentrations of sulfur ions in sprout's nutrient solutions (0.0, 0.5, 1.0, and 2.0 mM) and to different light sources [Fluorescent lamp, Red, Blue, and Mix (R+B) LED]. Kale sprouts were cultivated in a growth chamber for 13 days in sulfur solutions. Kale sprouts were treated with fluorescent lamp and LED light sources for 5 days, from eight days after sowing to harvest. Amount of seven types of GSLs (progoitrin, sinigrin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were measured in kale sprouts after harvest. The total GSL content was influenced by different sulfur solution concentration, and it was the highest at S 0.5 mM ($172.54{\mu}mol{\cdot}g^{-1}DW$) and the lowest at S 2.0 mM ($163.09{\mu}mol{\cdot}g^{-1}DW$). The GSL content was influenced by different light source, and it was the highest with Red LED ($159.23{\mu}mol{\cdot}g^{-1}DW$) and the lowest with Blue LED ($147.57{\mu}mol{\cdot}g^{-1}DW$). As the sulfur solution concentration increased under all light source, progoitrin and sinigrin contents tended to decrease while glucobrassicin content showed an upward tendency for all of the light sources. The content of glucobrassicin was higher than that of progitrin when treated with sulfur solutions for all LED light sources. Sinigrin, which has excellent anti-cancer effects, showed the highest rate (92.2%) among all the GSLs, under all of the light sources.

• 한국광학회지
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• 제27권2호
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• pp.73-80
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• 2016

본 논문에서는 광생물 반응기의 조명 시스템에 적용할 수 있는 LED(Light-Emitting Diode)와 태양광 하이브리드 광원을 이용한 도광판의 설계 및 제작 결과에 대해 보고한다. LED용 도광판 패턴을 설계하고 기존에 보고된 태양광용 도광판에 함께 중첩하여 가공하였다. 하이브리드 도광판의 출력 PFD(Photon Flux Density)를 일정하게 유지시켜주기 위한 제어 시스템을 제작하였으며, 출력 PFD 목표값을 $70{\mu}E/(m^2{\cdot}s)$로 설정하였을 경우 오차범위 ${\pm}2%$ 이내에서 제어가 이루어짐을 확인하였다.

• 원예과학기술지
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• 제31권4호
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• pp.415-422
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• 2013

본 연구는 식물공장용 LED 챔버 시스템에서 고추냉이의 생육반응에 미치는 LED 광원 및 광질의 영향을 알아보기 위해 적색, 청색, 백색 그리고 원적색광의 단일 및 혼합처리, 적색광과 청색광의 비율 그리고 duty비 등을 다양하게 처리하여 수행하였다. 고추냉이의 생육반응은 적색 + 청색 혼합광에서 가장 높았고, 단일광 조건에서는 청색광보다 적색광 하에서 식물체 생물량이 높았다. 고추냉이의 식물체 생물량과 분얼수는 적색과 청색광의 비율이 1:1인 조건에서 가장 높았다. 적색과 청색광을 혼합하여 처리 시 고추냉이의 생육반응은 duty비가 100%일 때 높은 반면, 적색과 청색광에 백색광을 첨가하여 처리 하였을 때는 duty비가 가장 낮은 97%에서 높았다. 엽면적과 잎건중량은 적색광에서 가장 높은 반면, 비엽면적은 청색광에서 가장 높았다. 적색과 청색 혼합광에서 엽면적과 잎건중량은 적색광의 비율이 높거나, duty비가 낮을수록 증가하였고, 백색광을 첨가한 조건에서는 duty비가 높을수록 증가했다. 이상의 결과를 종합해보면, 고추냉이는 단일광을 처리하는 것보다 적색과 청색광을 혼합하여 처리해 주거나, 청색광보다 적색광의 비율을 더 높여주는 것이 고추냉이의 생육 및 품질을 향상시켜 줄것으로 판단된다.

• 한국광학회지
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• 제19권2호
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• pp.116-121
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• 2008

본 연구는 2차원 PLS(Point Light Source) 배열과 디스플레이 장치의 조합을 통하여 시역형성용 광학판이 없는 3차원 영상을 재생하는 방법에 관한 것이다. PLS를 사용하여 3차원 영상을 디스플레이 하는 경우 기존의 시차장벽(parallax barrier), 렌티큘러(lenticular), 마이크로 렌즈(microlens lens) 등의 광학판을 사용할 때 발생하는 여러 가지 광학적 문제점 등을 해소할 수 있다. PLS로 사용된 LED 광원이 가져야 할 특성을 조사하였으며 PLS 배열을 통한 입체영상 디스플레이의 시역에 대해 실험을 통하여 입증 하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.157-159
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• 2006

The advantages of LED(Light Emitting Diode) are low electric power consumption, long life time and excellent visibility. And a LED light source does not include the mercury(Hg) and or a filament, it is expected as an environmentally friendly next generation light source with its good reliability. In order to design and develope the flash lantern using LED for aironautical ground lights, technical trends and new standards about the aironautical ground lights were inspected, and power consumption and flash time for effective luminous intensity of aironautical ground lights were analyzed.

• 한국정보통신학회논문지
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• 제19권4호
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• pp.954-964
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• 2015

본 연구는 균일한 조명을 얻기 위해 자유 형상 렌즈(freeform lens)를 제작하였으며, 이를 위해 중첩 조명 모델(overlapped illumination model)을 제안하였고, 제작한 LED 렌즈들의 특성을 분석하였다. 제작한 렌즈는 LED 빛 세기 분포의 중심 방향, 반치각 (half angle) 및 LED 광원의 위치변화를 바탕으로 그 성능을 평가하였다. 아울러 조명영역은 평균 조도 (average illuminance)와 조도 균일도 (illuminance uniformity) 변화 값으로 수행하였다. 광도 분포의 중심 방향 변화에 대해서는 제안된 모델과 발산 모델이 대체로 비슷한 공차 특성을 보였으며, 특히 제작한 렌즈에서 반치각 변화는 기존 방법에 비해 조도 균일도 공차 특성은 현저히 개선됨을 확인하였다.

• 조명전기설비학회논문지
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• 제25권10호
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• pp.14-22
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• 2011

The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

• 한국생산제조학회지
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• 제20권3호
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• pp.361-367
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• 2011

In this paper, it was attempted to analyze the optimal design of light emitting diode (LED), a source of back light unit (BLU). LED is beginning with commercialized red LED which is made by GaAsP compound semiconductor, and has been developed focusing on liquid crystal panel. In order to get the optimal design, optical simulation was made by analyzing luminosity shape, reflector angle, chip depth, and chip position of LED lighting. Final results show that the proposed LED characteristics were useful to increase light efficiency and it has been proven by distribution chart for actual exposed light on the light guide panel (LGP).