• 대한전자공학회논문지
• /
• 제10권3호
• /
• pp.1-9
• /
• 1973

파일롯트 램프와 숫자표시를 목적으로 국내에서 처음으로 화합물반도체인 갈륨 인을 사용해서 발광다이오드를 만들었다. 이같이 만든 다이오드는 밝고 선명한 붉은 빛을 냈으며 발광하는데 필요한 순방향 바이아스 전류는 5mA 이하였다. 다이오드의 p-n 접합면은 n형 GaP 단결정 기판에 liquid phase epitaxy방법으로 성장시켰고 이때의 Ga 용액의 온도는 약 1300°K정도를 유지했다. 이렇게 하여 제조된 p-n 접합체에 wire bonding으로 ohmic contact시켜 다이오드를 제조했다. 칼륨인 발광다이오드는 매우 적은 전류로 발광되는 장점과 성장 반웅시 질소를 불순물로 doping시키면 녹색으로 발광되는 장점을 갖고 있으므로 앞으로 양산화의 전망이 매우 밝다.

• 산업기술연구
• /
• 제30권B호
• /
• pp.113-118
• /
• 2010

In this paper, We proposed remote dimming control system for Light Emitting Diode(LED) street light using Power Line Communication(PLC). LED will be used widly by indoor or outdoor lighting because of semi-permanent life and environment restriction. For energy saving of street light, the dimming control system is very necessary and the PLC is a very efficient technique. Thus, in this paper we proposed the remote dimming control system for LED street light using PLC. A performance of the proposed system was validated by experimental results.

• 한국약용작물학회지
• /
• 제20권3호
• /
• pp.165-170
• /
• 2012

This study was conducted to evaluate the effect of light spectrum using red (660 nm), blue (460 nm), red and blue mixed (Red : Blue = 6 : 4) LED (light-emitting diode), and fluorescent lamp on antioxidant activities and functional components of dandelion (Taraxacum officinale). Total polyphenol contents in dandelion irradiated with the red and blue mixed or the red LED were 121.77 mg/100 g or 115.36 mg/100 g, respectively, which were greater than those in dandelion treated with blue LED and fluorescent lamp. Asparagine showed the highest content among amino acids in leaves and roots regardless of treatments. Total amino acid was the highest when illuminated with the red LED. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and SOD (super oxide dismutase) activity of ethanol extracts were increased under all of the LED treatments compared with fluorescent lamp, and the antioxidant activities were increased by the red and the mixed LED illumination. The results indicate that application of the red and the mixed LED illumination promote antioxidant activity and increase functional components during cultivation of dandelion.

• 한국버섯학회지
• /
• 제11권4호
• /
• pp.226-229
• /
• 2013

표고 톱밥재배시 LED광파장에 따른 생육특성을 분석한 결과, 파장이 긴 적색광과 황색광에서 대길이가 길어지고 갓색이 연해지며, 파장이 짧은 청색광과 녹색광에서는 대길이가 짧아지고 갓색이 진해지는 현상을 보였다. 자실체 항산화활성은 광파장에 따른 큰 차이를 보이지 않았으며, 2주기까지 배지당 자실체 수량은 녹색에서 159 g으로 형광등 121 g 대비 31% 증수효과가 있었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제29권6호
• /
• pp.830-837
• /
• 2016

The purpose of this study was to investigate the effect of monochromic light-emitting diode (LED) light with different color on the growth and reproductive performances of white Roman breeder geese. A randomized complete batch design was utilized for the trial, and the replicate was regarded as one batch. Twenty ganders and fifty-five dames were used in batch 1 (started on 2011/6/17 and ended on 2012/1/31), thirty ganders and eighty-four dames were used in batch 2 (started on 2012/3/23 and ended on 2012/10/26), and thirty ganders and seventy-two dames were used in batch 3 (started on 2013/3/12 and ended on 2013/12/20). Two hundred and ninety-one geese were randomly assigned to 6 rooms in an environmentally controlled house. They were randomly allotted into one of three monochromatic light treatments: Blue, red, or white. The results showed that there was no significant difference in body weight among the three lighting groups at any point throughout the experimental period. However, compared to the blue light group, significantly more eggs were produced by the red and white light groups (p<0.05). Furthermore, the laying period of the red light group was significantly longer than that of other two groups (p<0.05). In conclusion, our results suggested that red LED-light has the best effect on reproductive performance (i.e. longer laying period and higher total eggs number) at 30 lux light intensity, and is therefore a better choice for the management of breeding geese than blue or white LED-light.

• 한국전기전자재료학회논문지
• /
• 제24권1호
• /
• pp.42-46
• /
• 2011

Light can be divided into ultraviolet rays, visible rays, and infrared rays depending on the wavelengths. Visible rays with specific wavelength are those predominantly used for would treatment. Especially low level laser irradiates into cells, effectively stimulating cellular tissues and activating cellular function. This study was intended to verify the effect of white LED irradiation therapy on wound recovery in animal tests by applying white LED irradiator, which was independently designed and developed to emit beams of similar wavelength to that of a laser. The designed LED Irradiator was used to find out how white LED light source affected the skin wound of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; white LED irradiation group which was irradiated 1 hour a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.

• 센서학회지
• /
• 제29권3호
• /
• pp.180-186
• /
• 2020

In this study, we applied edge-pulse modulation to prevent the flicker of light-emitting diode (LED) light in a visible light identification system. In the visible light transmitter, positive pulses were transmitted at the edges of the low-to-high transition points, and negative pulses were transmitted at the edges of the high-to-low transition points of the non-return-to-zero (NRZ) data waveforms. In the visible light receiver, the NRZ waveforms were regenerated by making low-to-high and high-to-low transitions at the point of the positive and negative pulses, respectively. This method has two advantages. First, it ensures that the LED light is flicker-free because the average optical power of the LED was kept constant during data transmission in the transmitter. Second, the 120 Hz optical noise from the adjacent lighting lamps was easily cut off using a simple RC-high pass filter in the receiver.

• Journal of Photoscience
• /
• 제11권1호
• /
• pp.35-40
• /
• 2004

[Ru(2,2'-bipyridine)$_2$(4,4'-dicarboxy-2,2'-bipyridine)]$^{2+}$(RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To evaluate the usefulness of this luminophore (RuBDc) for studying macromolecular dynamics, its intensity and anisotropy decays when conjugated to RNA bacteriophage MS2 were examined using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and the mean intensity decay time was 442.2 ns. The anisotropy decay data showed a single rotational correlation time (2334.9 ns), which is typical for a spherical molecule. The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc can be useful for studying rotational diffusion of biological macromolecules.s.

• 반도체디스플레이기술학회지
• /
• 제3권4호
• /
• pp.39-43
• /
• 2004

The parallel multi-quantum well structures of blue and amber lights were designed and grown in metal-organic chemical vapor deposition by utilizing integration process on epitaxial layers. Samples were deposited for 5 periods-InGaN multi-quantum well layers for blue light emission and partially etched in order to regrow the 3 periods-InGaN multi-quantum wells for amber light. The blue and amber photoluminescence spectra were observed at the peak wavelengths of 475 and 580 nm, respectively. The chromatic coordinates of the white emitting diode were 0.31 and 0.34.

• 수산해양기술연구
• /
• 제51권4호
• /
• pp.475-483
• /
• 2015

The marine microalgae Isochrysis galbana was cultured under various light-emitting diode (LED) light conditions with different wavelengths to examine changes in growth and in amino acid and fatty acid profiles. The culture conditions for the microalgae were Conway medium, salinity of 33 psu, temperature of $24^{\circ}C$, and a 16/8 h light/dark photoperiod. Six light sources, including 5 units of 180W LED lamps (peak wavelength: blue [LB] 470 nm; green [LG] 525 nm; yellow [LY] 595 nm; red [LR] 636 nm; white [LW] 442 nm) and 1 unit of a 175W metal halide (MH) lamp, were used for the experiment. The dry cell weights ($gL^{-1}$) of I. galbana under different light conditions were in the order of LW>LB${\geq}$MH>LR>LG>LY. Levels of essential amino acids were revealed to be significantly higher under LW, LG, and MH than under the other wavelengths (P<0.05). The fatty acid, unsaturated fatty acid, and DHA contents of I. galbana were higher under MH, LW, and LG. In addition, the carotenoid content was higher under MH, LW, and LG than under the other wavelengths (P<0.05). The fucoxanthin content was highest under MH (0.28%) and lowest under LY (0.2%), and it was 0.26% under LW and LG. The results indicate that the combined use of LW and LG is effective when using LED lamps for I. galbana cultivation.