• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.251-252
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1017-1018
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• 2009

• Annual Conference of KIPS
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• 2022.11a
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• pp.794-796
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• 2022

본 논문은 에어컨 토출구 살균조명용 UV-LED 에 관한 연구이다. 서론에서는 에어컨 토출구에 증식하는 곰팡이의 문제점과 원인에 대해 조사 분석함으로써 연구의 목적을 설명하였다. 본론에서는 내부를 살균하며 동시에 무드조명의 역할을 수행함으로써 얻을 수 있는 장점과 작동방식에 대하여 설명하고, 가능성을 확인하기 위한 실험을 계획하였다. 실험계획과 실험결과에서는 이전 다른 실험과의 차이점과 실험계획을 설명하고, 실험결과에 대해 설명하며 이번 실험에서의 한계점 및 보안할 점도 함께 설명하였다. UV-LED 의 설치 위치를 예시를 들며 설명하였다. 결론에서는 본 논문에서 설명한 연구의 내용을 종합하고, 향후 연구의 진행방향과 추가적으로 필요한 실험 및 적절한 UV-LED 의 파장선택에 대해서 기술하였다.

• Journal of Life Science
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• v.31 no.10
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• pp.905-912
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• 2021

In this study, four common food-borne bacteria, namely, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Bacillus subtilis, were targeted via irradiation with 270 nm UV C-LED, 365 nm UV A-LED, 465~475 and 620~630 nm visible-LED, and 850 and 5,000~7,000 nm infrared-LED light. The effect on the growth of each bacterial species was investigated. In the case of 270 nm UV C-LED, all four strains showed inhibitory effects compared with the control group when irradiated for 10 or 30 min. Furthermore, when irradiated with 365 nm UV A-LED for 1 or 3 hr, B. subtilis showed 100% growth inhibition. When irradiated with 465~475 nm visible-LED for 1 hr, all four strains showed no significant difference from the control group but showed significant growth inhibition when irradiated for 3 hr. S. aureus and B. subtilis treated with 620~630 nm visible-LED; S. typhimurium and S. aureus treated with 850 nm infrared-LED; and E. coli, S. typhimurium, and S. aureus treated with 5,000~7,000 nm infrared-LED were confirmed to significantly proliferate compared with the control group. The results of this experiment show the potential of the use of various LED light sources as a food preservation and application technology by examining their effect on the inhibition and growth of food-borne bacteria and by grasping the characteristics of each wavelength.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.178-187
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• 2017

The aim of this study was to investigate the effect of different light sources on the levels of glucosinolates (GSLs) in rocket salad (Eruca sativa L.). The light sources used in the study were: natural light (Control-1 or 2), red light-emitting diodes(LEDs), blue LEDs, mixed red and blue LEDs (R+B LEDs), white LEDs, fluorescent lamps (FL), and fluorescent lamps plus UV-C (FL+UV-C). Two separate experiments were conducted [Experiment I: Control-1, Red LED, Blue LED, Mix (R+B) LED and Experiment II: Control-2, White LED, FL, FL+UV-C] because of the limited number of growth chambers in our laboratory. The rate of increase in the length of rocket salad leaves was the highest under red LEDs and, FL confirming that red LED and, FL affect the growth of rocket salad. We separated and identified seven types of GSLs from the rocket salad:glucoraphanin, diglucothiobeinin, glucoerucin, glucobrassicin, dimeric 4-mercaptobutyl GSL, 4-methoxyglucobrassicin, and gluconasturtiin. The highest total GSL contents in Eexperiment I was found in plants grown under in red LEDs ($4.30{\mu}mol{\cdot}g^{-1}\;dry$ weight, DW), and the lowest under blue LEDs ($0.17{\mu}mol{\cdot}g^{-1}\;DW$). The highest total GSL contents in Experiment II was found in plants grown under FL ($13.45{\mu}mol{\cdot}g^{-1}\;DW$), and the lowest in FL+UV-C ($0.39{\mu}mol{\cdot}g^{-1}\;DW$). Especially in Experiment II, the content of dimeric 4-mercaptobutyl, which has a strong aroma and spicy flavor in rocket salad, was higher under FL and white LEDs than in Control-2, increasing by approximately 14.9 and 3.2-fold respectively. Therefore, light sources such as red LEDs, white LEDs and FL affected the accumulation of GSLs in rocket salad.

• 프린팅코리아
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• v.12 no.5
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• pp.90-91
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• 2013

과거 몇 년 동안 에너지 효율 극대화를 목표로 자체 UV 드라이어의 새로운 기술을 개발해온 KBA의 신기술 HR(Highly Reactive ; 고반응도) UV 시스템 및 LED 드라이어가 시장 지배력을 얻어가고 있다. HR 드라이어는 2011년에서부터 2012년까지는 라피다145에 활용됐는데, 2013년 부터는 RA105, RA106, RA164에도 적용되고 있다.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.45-54
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• 2024

A proper level of UV-A light treatment in terms of intensity, spectrum, and exposure duration is known to have a positive impact on plant growth, photosynthesis, and the biosynthesis of secondary metabolites. However, there are few studies investigating the physiological responses of spinach (Spinacia oleracea L.) to UV radiation. Hence, this study aimed to assess the effects of short-term UV-A radiation on the growth and bioactive compounds of spinach. Spinach seedlings were cultivated in a vertical farm module under the following environmental conditions: photosynthetic photon flux density 200 µmol·m^-2·s^-1, white LED, 12 h on/off, 20℃ air temperature, 70% relative humidity, and 500 µmol·mol^-1 CO₂ concentration. After 5 weeks of sowing, the seedlings were subjected to continuous UV-A (peak wavelength; 385 nm) irradiation at two different energy levels: 20 W·m^-2 and 40 W·m^-2 for 7 days. As a result, the UV-A_20W treatment increased the shoot fresh and dry weights of spinach. However, there were no significant differences observed in photosynthetic parameters between the UV-A treatments and the control. The maximum quantum efficiency of photosystem II (Fv/Fm) consistently decreased across all UV-A treatments for 7 days in UV-A treatments. Additionally, the total phenolic content and antioxidant capacity increased in the UV-A_20W treatment at 7 days of treatment as well as the total flavonoid content significantly increased at 5 and 7 days of treatment. These findings suggest that supplemental UV-A LED radiation can enhance the growth and quality of spinach cultivated in closed type plant production systems such as vertical farms.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.88.1-88.1
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• 2015

In recent printed electronics technology, Photo-Sintering, a technique for sintering materials using a light source, has attracted attention as an alternative to time-consuming high-temperature thermal processes. The key principle of this technique is the selective heating of a strongly absorbent thin film, while preventing the heating of the transparent substrate by the light source. Many recent studies have used a flash lamp as the light source, and investigated the material-dependent effect of the width or intensity of the pulsed light. However, the flash lamp for sintering is not suitable for industry yet, because of needing too high power to sinter for a large scale. In energy-saving and large-scale sintering, LED technologies would be very useful in the near future. In this work, we investigated a sintering process for silver nanoparticles using UV-LED array. Silver nanoparticles in ink were inkjet-printed on a $1{\times}1cm$ area of a PET film and photo-sintered by 365 nm UV-LED module. A sheet resistance value as low as $72.6m{\Omega}/sq$ (2.3 - 4.5 times that of bulk silver) was obtained from the UV-LED sintering at 300 mW/cm2 for 50 min.

• Food Science and Preservation
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• v.19 no.1
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• pp.47-53
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• 2012

UV light irradiation is known to give beneficial effects on fresh produce preservation. A container system equipped with UV-LED was fabricated for storing cherry tomatoes under computer-controlled conditions of intermittent on-off cycles (1 hour on/1 hour off). Wavelength (365 and 405 nm) and physical location of the LED (2 and 5 cm above fruit) were studied as variables affecting the respiration, ethylene production and quality preservation of the fruits at 10 and $20^{\circ}C$. 365 nm wavelength gave much higher radiation intensity than 405 nm, and intensity on surface decreased in inverse proportion to square of distance from LED. When compared to non-irradiated control, UV-LED irradiation decreased the respiration by 5-10% at $10^{\circ}C$ while there was no obvious effect at $20^{\circ}C$. Ethylene production was reduced when the fruits were placed at 5 cm distance, while there was no significant difference from control at 2 cm location. The reduction of ethylene production at 5 cm was more pronounced at $20^{\circ}C$. UV-LED irradiation was shown to have delayed increase or lower concentration in carotenoids compared to control treatment. Any negative effect of UV-LED irradiation on ascorbic acid content and firmness was not observed.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.4
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• pp.87-92
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• 2007

A $CaAl_{12}O_{19}:Mn^{4+}$ red phosphor showed the highest emission intensity at a concentration of 0.02mole $Mn^{4+}$ and the high crystallinity and luminescent properties were obtained at $1600^{\circ}C$ firing temperature for 3hr. The synthesized phosphor showed a broad emission band at 658nm wavelength. Red light-emitting diodes(LEDs) were fabricated through the integration of on InGaN UV bare chip and a 1:3 ratio of $CaAl_{12}O_{19}:Mn^{4+}$ and epoxy resin in a single package. This coated LED can be applicable to make White LEDs under excitation energy of UV LED.