• The Korean Journal of Mycology
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• v.36 no.1
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• pp.31-35
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• 2008

To elucidate optimum light conditions for artificial cultivation of Grifola frondosa, the effects of light quality (blue, green, white) and light intensity (200, 500, 800, 1200 lux) on primordium formation, morphological properties and yield of fruiting bodies of G. frondosa using bag cultivation method were tested. Among three light sources, white light source ($400{\sim}620\;nm$) had a higher mushroom yield (242 g/bag) and a shorter cultivation period (52 days) than those of the others. In particular, blue light source ($400{\sim}560\;nm$) induced the morphology of wide and deep colored pilei in G. frondosa fruiting body. The experimental results on the appropriate light intensity indicated that 500 lux light was the most effective on mushroom production, whereas primordium formation was effective at 200 lux.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.104-113
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• 2022

Plants under the genus Orostachys have been known as medicinal plants. This study deems to determine the growth and leaf color of Orostachys japonica and O. boehmeri when subjected to various LED light sources. A total of seven LED light treatments were used, i.e. red (630 nm), green (520 nm), blue (450 nm), purple (650 and 450 nm), 3000 K white (455, 600 nm), 4100 K white (455, 590 nm), and 6500 K white (450, 545 nm) LEDs. Results showed that O. japonica plants showed favorable growth under 4100 K white LED, while O. boehmeri plants had a positive growth response under white light LEDs (3000, 4100, and 6500 K). In leaf color analysis, the use of green LED showed the greatest change in CIELAB L^* and b^* values which were relatively higher compared to other treatments indicating that leaves turned yellowish. Further statistical analysis using Pearson's correlation also suggested that there is a small negative association between dry weight and b^* values of O. japonica, and a negative moderate association between plant weights (fresh and dry weight) and leaf color (L^* and b^*) and positive association between said plant weights and a^* color values of O. boehmeri. Therefore, it is recommended to cultivate O. japonica under 4100 K white LED and O. boehmeri under 3000, 4100, 6500 K white LEDs.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.383-388
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• 2010

The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.208-214
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• 2017

This study aimed to determinate the effect of fluorescent light and light-emitting diodes on the leaf morphology, growth and antioxidant capacity of Salvia plebeia. The plants were grown for 56 days after transplanting (DAT) under the fluorescent light (FL) and LEDs (White, Red and Blue (R+B, ratio 2:1), Blue, Red LED) under the same light intensity and photoperiod ($130{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 hours). Leaf length, width and number of Salvia plebeia at the 56 DAT were significantly higher under the FL and red LED, and lower in the RB LED and white LED. The highest fresh and dry weights of shoot and leaf area were observed in the red LED, followed by the FL and blue LED, and the lowest in the RB LED and white LED. After 21 DAT, leaf apinasty symptom was appeared in plants grown under red LED and RB LED. The chlorophyll content was lower in the red LED. The specific leaf weight, the ratio of leaf dry weight to area, was higher in the blue LED, and lowest in the FL. No significant difference in DPPH radical scavenging activity of Salvia plebeia under the different light sources. All the integrated results suggest that the FL light is a proper light conditions for a closed cultivation of Salvia plebeia.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.67-67
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• 2020

Though there is an on-going need for the diversity of ornamental plants for in-door environment, their growth and stress adaptability in comparatively low light intensity condition require further studies for implementation. Here investigates the growth and chlorophyll fluorescence parameters of Farfugium japonicum (L.) Kitam, Liriope muscari (Decne.) L.H.Bailey and Acorus gramineus Aiton under several light intensities which were based on common in-door environment. The growth measurement of the plants included the quantity, length, width and SPAD value of the leaves. Calculated values of Fm/Fo, Fv/Fm, Pi_Abs, ETo/RC and DIo/RC were used as the parameters of the chlorophyll fluorescence under 10, 50, 100 and 200 PPFD (μmol·m^-2·s^-1) light intensities. In-door plants group was put in a closed room allowing no other light sources for 10 weeks and the control group was put in glass-greenhouse for the same period. The overall in-door growth of L. muscari was not significantly different in all light intensities compared to the control group and even showed the higher SPAD values. Also, an increasing tendency of Pi_Abs value under 10 to 100 PPFD was observed implying that L.muscari could adapt well to in-door environment. Measurement of A. gramineus growth mostly showed the highest values in the control group especially in the number of the leaves. Nevertheless, chlorophyll fluorescence parameters showed no significant value difference between in-door and the control groups and thus, A. gramineus might have possibility of successful adaptation to in-door environment. F. japonicum showed deficient growth in plant height and leaf length compared to the control but, it seemed to be able to sustain ornamental value under in-door light intensities. Furthermore, Pi_Abs and DIo/RC values were increased under in-door light conditions suggesting potential adaptability of F. japonicum.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.245-256
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• 2015

In the agricultural industries, LEDs are used as supplementary, as well as main lighting sources in closed cultivation systems. In cultivation using artificial light sources, various light qualities have been tried to supplement fluorescent lamps to promote plant growth and metabolism. Microarray analysis of Brassica rapa seedlings under blue and fluorescent mixed with blue light conditions identified changes in three genes of the glucosinolate pathway. This attracted attention as functional materials highly expressed 3.6-4.6 fold under latter condition. We selected four more genes of the glucosinolate pathway from the Brassica database and tested their expression changes under fluorescent light mixed with red, green, and blue, respectively. Some genes increased expression under red and blue mixed conditions. The Bra026058, Bra015379, and Bra021429; the orthologous genes of CYP79F1, ST5a, and FMOGS-OX1 in Arabidopsis, are highly expressed in Brassica rapa under fluorescent mixed with blue light conditions. Further, Bra029355, Bra034180, Bra024634, and Bra022448; the orthologous genes of MAM1, AOP3, UGT74B1, and BCAT4 in Arabidopsis, are highly expressed in Brassica rapa under fluorescent mixed with red light conditions. The various light conditions had unique effects on the varieties of Brassica, resulting in differences in glucosinolate synthesis. However, in some varieties, glucosinolate synthesis increased under mixed blue light conditions. These results will help to construct artificial light facilities, which increase functional crops production.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.204-211
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• 2022

To produce a high quality crop, light is an essential environmental factor in greenhouse cultivation. In the winter season, solar radiation is weak than other season. Therefore, using supplemental light during a low radiation period can increase the crop growth and yield. This study was conducted to select the economical supplemental light source for greenhouse cultivation in pepper during the low radiation period. The green pepper (Capsicum annuum 'Super Cheongyang') was transplanted on 5 September 2019. Supplemental lighting treatment was conducted from 1 January 2020 to 31 March 2020. RB LED (red and blue LED, red:blue = 7:3), W LED (white LED, R:G:B = 5:3:2), and HPS (high-pressure sodium lamp) were used as the supplemental light source. Non-treatment was used as the control. The plant height, SPAD, and number of nodes of pepper plants have no significant differences by supplemental light sources. However, the number of ramifications plants was the greatest in RB LED light source. Moreover, supplemental lighting increased photosynthesis of the pepper plant, and especially, the RB LED had the highest photosynthesis rate during supplemental lighting period. Also, the yield of pepper increased in the supplemental lighting treatment than in the control, and the RB LED had the greatest yield than other light sources. The electricity consumption was the highest in W LED and the lowest in HPS light. Through the economic analysis, the RB LED had high economic efficiency. In conclusion, these results suggest that using RB LED for supplemental light source during low radiation in pepper greenhouse increase the yield and economic feasibility.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.547-550
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• 2005

Gauge blocks are the most widely used material measure in length field in industry. The gauge block interferometer, which is the gauge block measuring system, comprises Twyman-Green type interferometer optics and light sources having precisely known wavelengths. This paper describes the work done for advancing the measurement system and automating the measurement process. The advancing of the system was done mainly by exchanging the spectral lamp with the frequency stabilized lasers, and the automation of measurement was achieved by modifying the hardware and developing the automatic measuring software. As the results of this work, the contrast of interferometric fringes of gauge blocks longer than 100 mm s enhanced about 20 times, and the measurement time has reduced down to 50% by automation.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1167-1171
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• 2008

The flow and thermal performance of the skiving and louver fin type heat sinks for the cooling system of the small LED projector were experimentally evaluated. A small fan tester based on AMCA standards was used to control and measure the air flow rate into the heat sink. Three heat blocks were used to simulate the heat and light sources(red, green and blue) of the small LED projector. We measured the pressure drop, temperatures and input power at the specific air flow rate and discussed those results. As a result, it is found that the louver fin type heat sink has higher pressure drop and lower thermal resistance than the skiving type. From the comparison of the temperature of the heat block between skiving and louver fin type, the louver fin type heat sink was found to be more suitable for cooling the high power heat source than skiving type. The thermal performance of the fan-sink(louver fin type) system was discussed with the picture taken by a thermal video.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.80.1-80
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• 2003

Several plant and microbial genes that could confer disease resistance in transgenic rice plants are being cloned and characterized. We are currently constructing transgenic rice lines that overexpress the gene products, such as a galactinol synthase, a defensin, and a bacterial ACC deaminase. Subtractive hybridization of a rice cDNA library constructed from the Xanthomonas oryzae-infected ice leaves resulted in isolation of many inducible cDNA clones including a elongation factor EF2, a oryzain alpha, a catalase, a aldehyde dehydrogenase, a S-adenosylmethionine synthetase, a caffeic acid O-methyltransferase, a glyceraldehyde-3-phosphate dehydrogenase, a light-regulated protein, nKY transcription factors, and a nucleotide diphosphate kinase. Some genes among those may be useful genetic sources for construction of disease resistant transgenic rice. Full lengths of the rice OsFIERG and a rice oryzain genomic clones were cloned, and serial deletion fragments of the promoter regions of these genes were fused with GUS reporter gene in pCAMBIA1201, respectively. Promoter activities of these constructs will be examined upon various stresses and Pathogen infections to obtain the pathogen specific inducible-promoter. This work was supported by a grant from BioGreen 21 Program, Rural Development Administration, Republic of Korea.