• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.993_994
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• 2009

본 논문에서는 RGB 멀티칩 LED모듈을 구성하고 포워드 컨버터 방식의 Red LED의 구동전압인 13V 및 Green과 Blue LED의 구동전압인 21V의 다중출력 SMPS를 설계하였다. 설계 제작된 SMPS로 RGB 멀티칩 LED 모듈을 구동하였으며 21V 및 13V의 전압 출력이 안정적으로 구동됨을 확인하였으며 Red, Green, Blue 각각의 LED는 안정적으로 구동됨을 확인하였다. 또한 구동용 SMPS는 역률제어를 통하여 안정성을 향상시켰다.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.99-112
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• 2020

A edible mushroom, Hypsizygus marmoreus is commercially cultivated. However, the researches of cultivation and physiological characteristics were not conducted in Korea. In this study, we conducted on artificial cultivation of H. marmoreus and elucidated the effect of light on the mycelial growth and fruit body development using LED light sources with different wavelength; blue (peak wave length 460nm), green(peak wave length 530nm), yellow(peak wave length 590nm), red(peak wave length 630nm), and white as positive control. Mycelial growth of H. marmoreus strains were inhibited about 30~40% in inhibition ratio under the illumination with blue, green, yellow LED light. However, red LED light was not inhibited. Elongation of stipe was effective under the long wave length such as yellow and red light. Abnormal fruit body was produced under the long wavelength and dark. However, development of pileus was effective under the short wavelength such as green and blue light. Also, as a result of cultivation with mixed light for high quality and harvest, many effective numbers and yields of fruiting bodies were obtained in the mixed treatment of blue and white light, and pileus developed well.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.816-823
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• 2016

This paper studies a light emitting diode(LED) overlapping method of a head-up display that consists of a digital micro device(DMD) panel and a red, green, blue LED in order to increase the brightness of display system and optical output power. This optimization overlapping method removes a quantization noise which occur due to LED overlapping too excessive and stabilizes the junction temperature of LED. In order to reduce junction temperature of LED, the a correlation between a green duty and LED overlapping ratio is studied. Throughout this study, the brightness of head-up display exhibited high increasement ratio of luminance around 33.3 percent at 39 percent overlapping method.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.101-111
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• 2012

The purpose of this study is to draw emotional evaluation model related to LED lighting colors and suggest basic informations that enable planned directions of architectural pacade lighting to simulate beforehand in a laboratory. As experimental methods, extracted PAD emotional evaluation model and then directed a experimental model of 10 LED lighting colors, studied and analyzed survey questions. The results are as follows; First, in the case of P(Pleasure-Unpleasure), Red, Yellow, Green, Cyan, Magenta, White and Combination of $G{\leftrightarrow}B$ Colors are satisfying, vibrant and positive distribution chart has shown. Second, in the case of A(Arousal-Unarousal), Red, Yellow, Green, Cyan, Blue, White and Combinations of $R{\leftrightarrow}G$, $G{\leftrightarrow}B$, $R{\leftrightarrow}B$ Colors, it makes a little difference, they have shown useful distribution chart to induce sight in a aroused state. Third, in the case of D(Dominance-Submissiveness), Red, Cyan, Green and Combinations of $G{\leftrightarrow}B$ Colors are free, controlling and extent of effect was excellent. On the contrary, in the case of Yellow and Magenta and Combinations of $R{\leftrightarrow}B$, they are gentle and arouse the protective instinct or feminine distribution chart has shown. Fourth, it showed difference of preference that difference of select ratios of both men and women in Orange, Blue, Greenish-Yellow (preference of man) and Magenta, Combinations of $R{\leftrightarrow}B$ Colors(preference of woman).

• Journal of Information Display
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• v.10 no.4
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• pp.164-170
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• 2009

The dependences of color gamut size and power consumption on the area ratio of the neutral and green subpixels for the RGB-LED-backlight RGBW LCD were studied, in which the red- and blue-subpixel areas are the same and represent one-quarter of the pixel aperture area. It was found that the color saturation of the RGBW LCD can be improved through the use of a smaller neutral- and green-subpixel area ratio, at the expense of higher power consumption.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.3
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• pp.211-218
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• 2017

The catch performance of the silver-white jig for automatic jigging machine, developed to improve the effectiveness of LED fishing lamp in catching squid, was compared to that of the conventional green jig. The vessels used in this investigation were Haesong-ho (A-vessel), a training vessel of Gangwon State University and Haengbok-ho (B-vessel), a commercial fishing boat. In the case of the A-vessel, five to eight automatic jigging machines were used in the fishing operation with a 31.3 kW LED fishing lamp in summer. As for the B-vessel, fourteen automatic jigging machines were used with a 43.2 kW LED fishing lamp in autumn and winter. The results showed that the catch performance of the silver-white jig was similar to that of the green jig in the case of the A-vessel (p>0.05). However, in the case of the B-vessel, the catch performance of the silver-white jig was superior to that of the green jig in both winter (p<0.05) and autumn (P<0.001). Based on the catch performance results regarding the B-vessel in autumn, it is expected that the annual income increase that can be earned by using the silver-white jig will be KRW 26,385,000.

• Journal of the Korean Professional Engineers Association
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• v.42 no.5
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• pp.41-45
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• 2009

The last century of lighting has been dominated by incandescent, fluorescent and high-intensity discharge(HID)light sources. In the late 1970's, after green LEDs were invented, Dr. Ching Tang at Eastman Kodak discovered that sending an electrical impulse through carbon compound caused such material glow. Present day LED commercial packages have reached 100 lm/W, comparable to the efficacies of fluorescent and certain HID lamps. LED products available today are market as "Green-Industry" but actually low light output compared to typical light sources. The combination of high price and low light output make them a poor replacement for current technology. It is very important to compare new LED products to the most efficient conventional technology that could be used for any specific application. As LED technology advances, costs decrease, and efficiency improves, LEDs will build market share in the general illumination market.

• Journal of the Optical Society of Korea
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• v.11 no.2
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• pp.67-70
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• 2007

A Wide Color Gamut Backlight system was studied using a three-band white Light-Emitting Diode. A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 445-nm blue peak, and a green phosphor and red phosphor that emit 535-nm green and 621-nm red peak emissions, respectively, when excited by 450-nm blue light. Using for this three-band white LED, wide color gamut backlight unit (BLU) was attained. The luminance of BLU and CIE 1931 chromaticity coordinates was $1,700Cd/m^2$ and (0.337, 0.346). Color filter matching simulations for this configuration show that the three-band white LED backlight can be enhanced by up to 16% over conventional white LED backlight color gamut.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.81-86
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• 2023

Recently, there has been an increased demand for light-emitting diode (LED) due to the growing emphasis on environmental protection. However, the use of GaN-based sapphire in LED manufacturing leads to the generation of defects, such as dislocations caused by lattice mismatch, which ultimately reduces the luminous efficiency of LEDs. Moreover, most inspections for LED semiconductors focus on evaluating the luminous efficiency after packaging. To address these challenges, this paper aims to detect defects at the wafer stage, which could potentially improve the manufacturing process and reduce costs. To achieve this, image processing and deep learning-based defect detection techniques for Sapphire Epi-Wafer used in Green LED manufacturing were developed and compared. Through performance evaluation of each algorithm, it was found that the deep learning approach outperformed the image processing approach in terms of detection accuracy and efficiency.

• Journal of Mushroom
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• v.12 no.4
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• pp.258-262
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• 2014

We aim to elucidate suitable mixed color of light during development of fruit body in Pleurotus ostreatus. The four mixed color of LED(Light Emitting Diode), blue and white, green and white, blue and green and green and red LED, were irradiated for formation of fruit-body. First, as effect of mixed color of LED, the properties of fruit body of P. ostreatus in blue and white LED irradiation were showed higher commercial yields than those in control(fluorescent lamp). And the ergothioneine was the highest at the blue and white LED. Second, we could obtain higher commercial yields than those at the $1{\mu}mol/m^2/s$ of light intensity by blue and white LED in P. ostreatus.