• Asia Pacific Journal of Business Review
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• v.2 no.2
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• pp.1-15
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• 2018

The purpose of this paper is to find out the factors responsible for purchase of LED (light-emitting-diodes) bulbs & tubes among Indian consumers and how much they are ready to replace their existing lighting system with LED fittings. A multiple regression model has been employed to investigate the factors affecting the buying decision of LED lamps in place of CFL and incandescent lamps. Eleven motives for adopting LED lamps has been identified viz. price, quality, energy saving, durability, brand, promotion, CSR, & environmental consciousness. In addition the effect of demographic variables like gender, age, household income on the purchasing decision of LED has also been examined. A total 150 respondents were contacted visiting different outlet of electrical shops of Northern Delhi. The study may helpful for the companies to decide their marketing strategies to promote LED Lamps among the consumers with an aim to save energy and save environment.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.374-380
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• 2010

This experiment was carried out to investigate the effect of light qualities and lighting types provided by LED Chamber System which designed by Rural Development Administration on growth and development of Chrysanthemum (Dendranthema grandiflorum L., cv. 'Cheonsu') plantlet cultured in vitro. The explants of single-node cuttings were exposed to monochromic or mixture radiation of blue, red, or green under continuous and intermittent lighting for 42 days. The intermittent lighting of 20 sec. on and off per minute significantly stimulated shoot elongation with lower number of internodes compared with continuous lighting treatments. However, continuous blue, red, or green light gave greater dry weight comparing the intermittent lighting, and the lowest weight was recorded at the continuous fluorescent lamp. Otherwise, the plantlet growth in dry weight or leaf area was inhibited by the green light controlled at 50 times intermittence but internode elongation was significantly increased. These results showed that the plantlets were successfully grown under the LED Chamber System controlled with different light qualities and lighting types. Quantitative growth of the plantlets was improved under the shorter photoperiod with a intermittent lighting cycle compared with continuous lighting using fluorescent lamps. It is concluded that the growth and development of in vitro plantlets such as single-node cuttings can be achieved by the controlling of light quality or lighting type during the photoperiod per day with a lower electric cost compared with conventional continuous lighting system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.16-23
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• 2011

Since the first lighting light source was invented, lighting has turned into superior-quality lighting considering the amenity of occupants, and the characteristics of a light source has developed rapidly. So this research confirmed the lighting performance of a dimmer control system and an ON-OFF control system via the existing light source, and analyzed the basic lighting environment of Permanent Supplementary Artificial Lighting of Interiors(PSALI) through the physical comparison and evaluation of a LED lamp substituted for a fluorescent lamp used in a dimmer control system, showing that the lighting physical quantity characteristics of an ON-OFF control system and a dimmer control system are similar to each other and that they are effective in terms of energy saving. Besides, it was shown that introducing a LED light source to a dimmer control system improves lighting environments and largely reduces energy consumption.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.265-272
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• 2019

The purpose of this study was to investigate the effects of LED and QD-LED (Quantum Dot) irradiation on seed germination, antioxidant ability, and microbial growth, during red radish (Raphanus sativus L.) sprouts cultivation. Irradiated light was blue, red, blue + red and blue + red + far red (QD-LED) lights, and the controls were a fluorescent lamp (FL), and dark condition. Germination rate of red radish was highest in the dark condition. The plant height and fresh weight of red radish sprouts that irradiated each light for 24 hrs after 7 days growing in dark condition, did not shown significantly difference among treatments. After 24 hrs of light irradiation, cotyledon green was best in blue + red light, and the red hypocotyl was excellent in blue light and QD-LED light. DPPH and phenol contents were high in dark and blue + red light treatment, and anthocyanin content was high in blue light and QD-LED light. Total aerobic counts were similar in all treatments and did not show bactericidal effect, whereas E. coli count was lowest in QD-LED light treatment, and yeast and mold counts were lowest in FL only treatment. Results suggest that when red radish seeds were germinated in dark condition and cultivated for 7 days as sprouts, and then treated with blue light or QD-LED light for 24 hrs, the seeds produced good quality red radish sprouts with greenish cotyledon, reddish hypocotyl, high anthocyanin content, and lower level of E coli contamination.

• Journal of Plant Biotechnology
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• v.48 no.1
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• pp.62-70
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• 2021

We analyzed the growth and quality characteristics of barley sprouts grown under artificial light sources consisting of a fluorescent lamp or light-emitting diode (LED) in an aquaculture system (grown with water only, without nutrients). At the end of the observation period, the shoots grown under the fluorescent lamp treatment were the longest, followed by the LED treatment and natural light-treatment. It was also observed that growth was faster for sprouts subjected to a non-sterilizing treatment than those subjected to a 70% ethanol treatment. As the seed sowing rate for planting trays increased, the yield of harvested barley sprouts increased; among light treatments, the natural light treatment resulted in the lowest yield, while the fluorescent light treatment resulted in the highest. The total phenol and total flavonoid contents of extracts of the barley sprouts were highest for the natural light treatment, but TEAC and FRAP were both highest for the fluorescent lamp treatment. The essential amino acid content ranged from 41.64 to 45.93 mg/g and was relatively higher for the natural light treatment than the other two treatments, while the content of non-essential amino acids was highest for the LED treatment. The total amino acid content was highest for the LED treatment at 97.47 ± 6.30 mg/g, for which the content of non-essential amino acids (53.17%) was higher than that of essential amino acids (46.83%).

• Mycobiology
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• v.41 no.1
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• pp.63-66
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• 2013

This study was conducted to identify a suitable color of light for development of the fruit body in Hypsizygus marmoreus. To accomplish this, samples were irradiated with blue (475 nm), green (525 nm), yellow (590 nm), or red (660 nm) light emitting diodes (LEDs) to induce the formation of fruiting bodies after mycelia growth. The diameter and thickness of the pileus and length of stipes in samples subjected to blue LED treatment were similar to those of subjected to fluorescent light (control), and the lengths of the stipes were highest in response to treatment with the red LED and darkness. The commercial yields of plants subjected to blue and green LED treatment were similar to those of the control. In conclusion, cultivation of H. marmoreus coupled with exposure to blue LED is useful for inducing high quality fruit bodies as well as higher levels of ergosterol, DPPH radical scavenging activity, total polyphenol content and reducing power.

• Journal of Industrial Convergence
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• v.22 no.2
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• pp.55-62
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• 2024

Visible light communication, which transmits information using visible light, has advantages such as ultra-high speed, ultra-delay, and ultra-connectivity, so research is being conducted as a way to complement 6G communication. In this paper, a study was conducted to overcome the performance degradation caused by the RGB mixing ratio in visible light communication. In a visible light communication system using LED lighting, the role of lighting is an important function, and when used for communication, the performance difference according to the RGB mixing ratio inevitably occurs. In particular, if the intensity of light is below a certain standard, the problem of deteriorating the performance of the entire system occurs. In this study, when a certain performance or less occurs in the communication system caused by the difference in the mixing ratio among the three RGB channels, the remaining two signals except the LED with the best performance are transmitted to STBC (Space-Time Block Coding) to ensure the quality of communication. A computer simulation was performed to verify the performance of the proposed system, and it can be seen that the performance of the proposed system is improved compared to the existing system.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.263-268
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• 2014

This research was performed to investigate the effect of light source and light quality in night break treatment on the growth and flowering of standard chrysanthemum. It was processed 4 hours (22:00-02:00) night break using LED 590, 610, 630, 660, 680nm and fluorescent lamp (mixed light of 480+540+610nm) in standard chrysanthemum 'Baekma' and 'Jinba' for 40 days from transplanting. The days to flower budding from short-day treatment of 'Baekma' were the longgest at fluorescent treatment (21.3 days) and were the shorttest at LED 590nm treatment (15.8 days) among all treatments. The days to flower budding from short-day treatment of 'Jinba' was longger with 18.0 days, 17.8 days, and 17.7 days at the fluorescent, LED 610nm, and 660nm treatments. And it was the shortest with 15.1 days in LED 590nm treatment. Similarly, the days to flowering from short-day treatment of 'Baekma' was the longgest with 56.9 days at fluorescent treatment, and was the shorttest in 51.6 days about LED 590 nm treatment. The days to flowering from short-day treatment of 'Jinba' was longer at fluorescent (56.0 days) and LED 660nm (56.7 days) treatments and was shortest at LED 590nm (52.9 days) among all treatments. Therefore, inhibition of flower bud initiation and flowering were the most effective under fluorescent treatment in case of 'Baekma', and fluorescent and LED 660nm treatments in case of 'Jinba'. The length and weight of cut flower of 'Baekma' and 'Jinba' were most excellent in fluorescent treatment in which the floral differentiation suppression effect was the best. Consequently, as to the growth and flowering of standard chrysanthemum, the treatment which was suitable as the light source and light quality for night break is regarded as the fluorescent lamp, and also under LED 660nm up to a certain level.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.8-13
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• 2010

For better picture quality in LCD TVs, it is important to reach a steady emitting state within as short a time as possible in the initial stage after the TV is turned on. The initial characteristics of LCD TVs are mainly determined by the properties of the backlight. In the present study, the photometric and spectroscopic properties of a 55-inch Cold Cathode Fluorescent Lamp (CCFL) and Light Emitting Diode (LED) backlights were investigated. The measured properties include time dependence of the spectrum, luminance, and color coordinates. The results show that the change in the spectroscopic properties of the LED backlight is smaller than that of the CCFL backlight. This indicates that the initial picture quality of the LCD TV with the LED backlight is superior to that with the CCFL backlight. The origins of this difference were discussed in relation to the inherent characteristics of the two light sources.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.223-229
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• 2000

This study was conducted to analyze the opto-electric characteristics of light-emitting diodes(LED) designed for growth and morphogenesis control of transplant and to quantify the photon flux emittig from LED using a quantum sensor spectroradiometer. Difference in photon flux for blue and red LED between measured by a quantum sensor and measured by a spectroradiometer and numerically integrated was not observed. This result implies a spectroradiometer can be applied to quantify the photon flux emitting from far-red LED, which can not be measured using a quantum sensor. Since photon flux increases in proportion to wavelength, photon flux of LED modules arranged for red and far-red increased in proportion to wavelength, photon flux of LED modules arranged for red and rar-red increased gradually as the number of LED stick emitting far-red in LEd modules increased. Illumination of LED modules arranged for red and far-red decreased as the number of LED stick emitting far-red in LED modules increased. There was no difference in irradiance between LED modules arranged for red and far-red.