• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.499-508
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• 2014

In this paper, we implemented a LED sensitivity illumination system, being driven in response to changes in the biological signals of GSR and PPG signal. After measuring biological signals of a human body from GSR and PPG sensor modules, MCU decided the state of relaxation or arousal of the subject, being based on the wake relaxation identifying map proposed in this paper. A developed LED sensitivity illumination system makes the subject to reach a normal state by giving a change of the LED illumination color, corresponding to a state of the subject.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.47-56
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• 2010

For a human being's smooth activity, the clean air and comfortable lighting environment are needed. The suitable lighting environment is obtained generally by making it available for being formed the bright situation easy for seeing object and the visually comfortable atmosphere. In this way, even the lighting environment was changed along with economic development. Even a light source was diversified. Thus, several kinds of new light sources such as LED, OLED, PLS, and CNT came to appear. Halogen lamp, which has low efficiency due to high color rendering among lamps of being used now, is being much used yet. However, owing to radiation of UV and IR, there are many limitations to the subject in general exhibition lighting, museum, and art museum. Accordingly, a research was performed on filter that is blocked UV and IR at the same time, by using halogen lamp that is excellent in color rendering and in life.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.475-478
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• 2004

In this paper, we describe a powerful solution for efficient LED wall calibration through the use of a quality 2D-luminance meter : the MURATest and a dedicated applicative software. The intended calibration allows adjusting individually the intensity of each LED so as to obtain a good uniformity on the module. Furthermore the intensity of each module can be adjusted one to the others so as to obtain a good uniformity on a complete display and maintain it even after module exchange for display maintenance needs.

• Journal of Mushroom
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• v.15 no.4
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• pp.264-268
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• 2017

In the 21st century, information and communication technology (ICT) worldwide presents a new vision for agriculture. Time and place, as well as the high-tech industry, to overcome barriers to the fusion of the so-called "smart agriculture," are changing the agricultural landscape. Core container production in precision agriculture for mushroom cultivation, optimal temperature, humidity, irradiation, self-regulation of factors such as carbon dioxide, and environment for mushroom cultivation were adopted. Lentinula edodes (shiitake) is an edible mushroom native to East Asia, cultivated and consumed in many Asian countries. It is considered to be medicinal in certain practices of traditional medicine. We used different controlled light sources (Blue-Red-White-combined LED, blue LED, red LED, and fluorescent light) with different LED radiation intensities (1.5, 10.5, and $20.5{\mu}mol/m^2s$ for LEDs) to compare growth and development. Mushrooms were treated with light in a 12-hour-on/12-hour-off cycle, and maintained in a controlled room at $19{\sim}21^{\circ}C$, with 80~90% humidity, and an atmospheric $CO_2$ concentration of 1,000 ppm for 30 days. Growth and development differed with the LED source color and LED radiation intensity. Growth and development were the highest at $10.5{\mu}mol/m^2s$ of blue LED light. After harvesting the fruit bodies, we measured their weight and length, thickness of pileus and stipe, chromaticity, and hardness. The $10.5{\mu}mol/m^2s$ blue-LED-irradiated group showed the best harvest results with an average individual weight of 39.82 g and length of 64.03 mm, pileus thickness of 30.85 mm and pileus length of 43.22 mm, and stipe thickness of 16.96 mm with fine chromaticity and hardness. These results showed that blue LED light at $10.5{\mu}mol/m^2s$ s exerted the best effect on the growth and development of L. edodes (shiitake) mushroom in the ICT-system container-type environment.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.561-568
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• 2002

Purpose of this research is estimating polymerization depth of different source of light. XL 3000 for halo-gen light, Apollo 95E for plasma arc light and Easy cure for LED light source were used in this study. Different shade (B1 & A3) resin composites (Esthet-X, Dentsply, U.S.A.) were used to measure depth of cure. 1, 2, and 3 mm thick samples were light cured for three seconds, six seconds or 10 seconds with Apollo 95E and they were light cured with XL-3000 and Easy cure for 10 seconds, 20 seconds, or 40 seconds. Vicker's hardness test carried out after store samples for 24 hours in distilled water. Results were as following. 1. Curing time increases from al1 source of lights, oui$.$ing depth increased(p<0.05). 2. Depth (that except 1mm group and 2mm group which lighten to halogen source of light) deepens in all groups, Vickers hardness decreased(p<0.05). 3. Vicker's hardness of A3 shade composite was lower in all depths more than B1 shade composites in group that do polymerization for 10 seconds and 20 seconds using halogen source of light(p<0.05), but group that do polymerization lot 40 seconds did not show difference(p>0.05). 4. Groups that do polymerization using Plasma arc and LED source of light did not show Vicker's hardness difference according to color at surface and 1mm depth(p>0.05), but showed difference according to color at 2mm and 3mm depth(p<0.05). The results showed that Apollo 95E need more polymerization times than manufacturer's recommendation (3 seconds), and Easy cure need polymerization time of XL-3000 at least.

• 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 Internet Computing and Services
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• v.24 no.2
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• pp.19-26
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• 2023

Humans have adapted and evolved to natural light. However, as humans stay in indoor longer in modern times, the problem of biorhythm disturbance has been induced. To solve this problem, research is being conducted on lighting that reproduces the correlated color temperature(CCT) of natural light that varies from sunrise to sunset. In order to reproduce the CCT of natural light, multiple LED light sources with different CCTs are used to produce lighting, and then a control index DB is constructed by measuring and collecting the light characteristics of the combination of input currents for each light source in hundreds to thousands of steps, and then using it to control the lighting through the light characteristic matching method. The problem with this control method is that the more detailed the steps of the combination of input currents, the more time and economic costs are incurred. In this paper, an LED lighting control method that applies interpolation and combination calculation based on the minimum spectral power distribution information for each light source is proposed to reproduce the CCT of natural light. First, five minimum SPD information for each channel was measured and collected for the LED lighting, which consisted of light source channels with different CCTs and implemented input current control function of a 256-steps for each channel. Interpolation calculation was performed to generate SPD of 256 steps for each channel for the minimum SPD information, and SPD for all control combinations of LED lighting was generated through combination calculation of SPD for each channel. Illuminance and CCT were calculated through the generated SPD, a control index DB was constructed, and the CCT of natural light was reproduced through a matching technique. In the performance evaluation, the CCT for natural light was provided within the range of an average error rate of 0.18% while meeting the recommended indoor illumination standard.

• Korean Journal of Poultry Science
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• v.42 no.2
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• pp.125-132
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• 2015

The Far Infrared Ray (FIR) is part of the natural energy as light spectrum of sunlight. Human can disentangle the colors within visible ray, but FIR is invisible to human sight because it has longer wavelength than visible ray. The effect of using FIR on broiler performance, blood biochemical profiles and fecal gas emission from litter. Day-old semi-broiler chicks (Ross ♂ ${\times}$ Hyline ♀) were obtained and assigned to eight pens, 2 replicates of white and green color LED light, and with FIR on each color light, in a 20L:4D of lighting program. The body weight gain and feed efficiency were tend to improve under the green color than white color, which were increased by exposing to FIR on both color light. Emission of ammonia and lower hydrocarbons from litter were not different from each color but there was a decrease by exposing to FIR regardless of light color. The level of blood aspartate aminotransferase (AST) tends to be decreased under green color than white color, and this tendency becomes more pronounced as exposing to FIR. Therefore significantly increased under white color without FIR than green color with FIR (P<0.05). The levels of albumin and immunoglobulin were not different from each color but there was an increase by exposing to FIR regardless of light color. In conclusion, exposing to Far Infrared Ray (FIR) when broiler raising, there is potential to increase broiler performance because of improvement of bioactivity and raising environment.

• Food Science of Animal Resources
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• v.42 no.1
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• pp.142-152
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• 2022

The present study was aimed at examining the antibacterial effects of nonthermal decontamination processes, which are equivalent to thermal treatment, to ensure microbiological safety of raw ground chicken. Escherichia coli or Salmonella were inoculated into 25 g of raw ground chicken samples. The raw ground chicken samples were non-treated or treated with high hydrostatic pressure (HHP) at 500 MPa (1-7 min), light-emitting diode (LED) irradiation at 405 nm wavelength (30-120 min), and heat at 70℃, 90℃ (1-60 min), and 121℃ (1-15 min). E. coli and Salmonella cell counts were enumerated after treatments. Moreover, the color parameters of treated raw ground chicken were analyzed. HHP treatment reduced E. coli and Salmonella cell counts by more than 5 Log CFU/g and more than 6 Log CFU/g after 7 min and 1 min, respectively; these effects were equivalent to those of thermal treatment. However, LED irradiation reduced Salmonella cell counts by only 0.9 Log CFU/g after 90 min of treatment, and it did not reduce E. coli cell counts for 90 min. Compared with those of the non-treated samples, the ΔE (total color difference) values of the samples treated with HHP were high, whereas the ΔE values of the samples treated with LED irradiation were low (1.93-2.98). These results indicate that despite color change by HHP treatment, HHP treatment at 500 MPa could be used as a non-thermal decontamination process equivalent to thermal treatment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.1-12
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• 2008

The aim of this study is to investigate the sensitivity evaluation of human beings in reacting to the correlated color temperature of the optical properties of white LED lighting. For the sake of this study, white light-emitting diode modules have been fabricated their correlated color temperature have been measured, test cabinets for the sensitivity evaluation have been constructed with the white LED modules, and their sensitivity reactions on the test cabinets have been evaluated and analyzed. The sensitivity reaction has been evaluated by the semantic differential method with 15 selected questions, and the reliability and the content validity of their lighting have been analyzed to 3 factors which foe the activity as the first factor, the stability as the second one, the potency as the third one, respectively. For the data analysis on the sensitivity reaction, the dependent variable is the score of the sensitivity evaluation and the independent one is the correlated color temperature of the test module. The results of this study is as follows: In the case of the sensitive evaluation on the activity and the potency in the white LED lighting compared with the fluorescent lamp, the subjects have made higher mark on $MA_3$ with 8,300[K], and in the factor of the stability, they have made higher mark on $MA_1$ with 3,800[K].