• 감성과학
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• 제14권3호
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• pp.371-384
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• 2011

LED 조명의 색상이 정서자극의 평정과 재인에 어떤 영향을 미치는지를 알아보기 위하여 세 개의 실험을 실시하였다. 실험 1과 2에서는 IAPS 정서사진을 사용하여 각각 Red, Green, Blue, 및 White와 Cyan, Magenta, Yellow, 및 White의 조명색상조건에서 정서평정(정서가, 각성차원) 과제와 재인기억과제를 실시하였다. 실험 3에서는 정서단어를 사용하여 Red, Green, Blue, 및 White 조명색상조건에서 두 과제를 실시하였다. 실험 결과, 정서평정과제에서는 일차 색상(RGB)의 경우, LED조명 색상이 Red일 때는 흥분을, Green일 때는 유쾌 정서를 유발하였고, 이차 색상(CMY)의 경우, Magenta와 Cyan은 Red와 Green과 유사한 패턴의 정서 반응을 유발하였으나 그 강도는 약하였다. 재인기억과제에서는 실험 1과 실험 2의 경우, Green과 Cyan 조명색상조건에서 제시되었던 사진자극들에 대한 반응이 다른 조명색상조건에서 제시되었던 사진자극들에 비해 약간 빠른 경향이 있었으나 유의미한 차이는 아니었다. 하지만 실험 3에서는 Green 조명색상조건에서 제시되었던 정서단어들에 대한 재인기억반응이 유의미하게 빨랐다. 이러한 결과로 Red나 Magenta와 같은 난색들은 불쾌나 흥분과 관련된 감성을 유발하는 반면, Green이나 Cyan과 같은 한색들은 유쾌나 이완과 같은 감성을 유발하는 경향이 있으며, 일차 색상들이 이차 색상들보다 강한 정적 내지 부적 감성을 유발함을 알 수 있다. 특히 실험 3의 재인 기억과제에서 나타난 결과는 시각 자극보다 언어 자극의 기억수행에 Green 색상의 LED 조명이 더 유리함을 시사한다.

• Current Optics and Photonics
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• 제1권6호
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• pp.626-630
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• 2017

GaN-based green light-emitting diode (LED) structures suffer from low internal quantum efficiency (IQE), known as the "green gap" problem. The IQE of LED structures is expected to be improved to some extent by exploiting the Purcell effect. In this study, the Purcell effect on the IQE of green LED structures is investigated numerically using a finite-difference time-domain simulation. The Purcell factor of flip-chip LED structures is found to be more than three times as high as that of epi-up LED structures, which is attributed to the high-reflectance mirror near the active region in the flip-chip LED structures. When the unmodified IQE is 20%, the relative enhancement of IQE can be greater than 50%, without utilizing the surface-plasmon coupling effect. Based on the simulation results, the "green gap" problem of GaN-based green LEDs is expected to be mitigated significantly by optimizing flip-chip LED structures to maximize the Purcell effect.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.62-67
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• 2021

In this study, we have successfully developed an unique NVIS Green A compatible LED by combining two technologies. One is white LED made with a black EMC (epoxy molding compound) lead frame. The other is NVIS Green A filter that shields the near infrared region made in the film method. The form factor of the developed NVIS Green A compatible LED was 2.0 × 2.0 × 0.95 mm. And it is possible to satisfy NVIS radiance and color limit specified in MIL-STD-3009 by controlling the concentration of Green A dye and the thickness of the NVIS filter as well as adjusting of color temperature of the white LED. From these results, we are expected that the developed NVIS Green A suitable LED is a promising solution for the weight reduction and the cost reduction of avionic applications.

• 반도체디스플레이기술학회지
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• 제19권4호
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• pp.1-5
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• 2020

By adapting black body leadflame and thin film type Green A filter, we successfully demonstrated night vision imaging system (NVIS) Green A compatible LED. Fabricated NVIS compatible LEDs show small form factor compared to that of commercialized NVIS compatible LED. Especially, NVIS radiance and chromaticity of MIL-STD-3009 specification can be satisfied simultaneously and easily by controlling the color temperature of the white LED as well as the concentration of the Green A dye and the thickness of the Green A filter. The optimal dye concentration of the NVIS Green A filter is expected to be about 1 wt%. The results of this study are expected to contribute to miniaturization, weight reduction and localization of avionic display and lighting devices.

• KSBB Journal
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• 제28권6호
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• pp.428-432
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• 2013

The antimicrobial properties of Light-Emitting Diode (LED) are an area of increasing interest. The aim of this study was to evaluate the bactericidal effects of blue (peak at 456 nm), green (peak at 518 nm), red (peak at 654 nm) and blue-green combined (blue 456 nm : green 558 nm = 69:31) LED irradiation to pathogenic bacteria. For this, LED equipment providing power density of $10mW/cm^2$ was installed and plates were exposed to 0.9 or $3.0mW/cm^2$ to irradiate bacteria with 3.2 to $259.2mW/cm^2$ of energy density. As a result, blue and combined LED have shown bactericidal effects on Escherichia coli KCTC 1467 and Listeria monocytogenes ATCC 19115 after irradiation of $3.0mW/cm^2$ for 2 and 4 hr, respectively. Staphylococcus aureus KCTC 1916 was inhibited at 518 nm green LED irradiation. However, red LED irradiation showed no inhibitory effect to the other tested strains. Light technology that utilizes the bactericidal properties of blue (at 456 nm) and blue-green(blue 456 nm : green 558 nm = 69:31) combined LED may have potential applications in the food industry sector.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.514-523
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• 2023

The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

• Transactions on Electrical and Electronic Materials
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• 제11권5호
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• pp.226-229
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• 2010

Many methods exist that promote wound healing, including light therapy, which consists of light beams that assist the human body in treating and sterilizing wounds, as well as regenerating cells. Irradiation with specific wavelengths of either laser or LED light has been shown to induce beneficial proliferation of fibroblasts that, depending on the size of the wound, can be effective in promoting wound healing. The experiments in this study utilized 8 week old 250~300 g Male Sprague Dawley Rats (ILAR Code: NTacSam:SD) and included a non-irradiation group and a 525 nm green LED irradiation group (n of each group = 7). In experiments animals were allowed to rest for 24 hours after wounds had been excised, which was followed by non- irradiation or 525 nm green LED irradiation therapy one hour per day for 9 days. Immunohistochemical staining was conducted for cytokeratin in order to precisely measure the defect size. In addition, Masson's trichrome staining was utilized in order to compare levels of collagen between the 525 nm green LED irradiation group and the non-irradiation group. Animals exposed to 525 nm green LED irradiation (p<0.05) healed at a faster rate and had increased collagenosis compared with the non-irradiated control group. Thus, treatment with 525 nm green LED irradiation had a beneficial effect on wound healing and should be considered as a possible alternative to low power laser treatment.

• Journal of Applied Biological Chemistry
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• 제59권3호
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• pp.203-206
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• 2016

보리나방과 화랑곡나방 성충에 대한 LED 트랩의 곡물보관창고에서 이용가능성을 평가하기 위해 상업적 대조구 BLB 트랩과 비교한 실증실험을 통하여 유인효과를 비교하였다. 그 결과 4일 후 blue LED 트랩은 보리나방, green LED 트랩은 화랑곡나방에 대하여 대조구 BLB 트랩보다 높은 유인활성을 나타내었으며 곡물보관창고 외부에서 진행한 실험은 내부 실험보다 약 1.7배 높은 유인활성을 나타내었다. 이러한 결과를 바탕으로 blue LED와 green LED 트랩이 곡물보관창고에서 화랑곡나방과 보리나방을 방제하기 위한 친환경 저곡해충 방제법으로 적용 가능성을 보여주었다.

• Journal of Information Display
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• 제10권3호
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• pp.97-100
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• 2009

A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

• 한국전자통신학회논문지
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• 제16권2호
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• pp.219-226
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• 2021

LED-to-LED VLC(: Visible Light Communications) 기술은 기존의 VLC 기술과 달리 송신부와 수신부를 모두 LED로 사용한 기술이다. 본 논문에서는 Micro LED를 송신부로 사용한 Micro LED-to-LED VLC 기술을 연구하였다. Red, Yellow, Green, Blue, White 색상의 송/수신부 LED에 따라 통신 시스템의 상승 시간과 신호 대 잡음비를 측정하여 채널 용량을 비교하였다. 본 실험 결과에 따르면, 송신부 Micro LED가 Blue이고 수신부 LED가 Green일 때에 통신 시스템 중에서 가장 좋은 결과인 125 kbps의 채널 용량을 갖는 것을 확인하였다. 또한, OFDM(: Orthogonal Frequency Division Multiplexing) 신호를 사용하여 비트 에러율을 확인한 결과, 250 kbps까지는 통신이 가능함을 실험적으로 확인하였다.