• Annual Conference of KIPS
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• 2016.04a
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• pp.766-769
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• 2016

산업시설 가운데 화력발전소에 스마트 부하관제 시스템을 이용하여 메탈 조명을 LED 조명으로 대체하여 전력을 절감하였다. LED 조명의 빛의 세기를 조절 할 수 있는 디밍을 통해서 사용자의 다양한 요구사항을 반영할 수 있다. 수요 예측은 전력 사용량이 많은 시간대의 전력사용량을 분산시키는 시스템이다. 수요 예측 스케줄에 의해서 목표전력량에 도달하기 위해 설정된 시간대에 디밍으로 LED 조명의 전력량을 조절하여, 기존 LED 조명 대비 전력량을 27.8% 절감하였다. 외부에 눈과 비가 오거나 밤에 실내가 어두워져서 작업 환경에 영향을 미치는 경우가 있다. 실시간으로 조도를 측정하여 작업 환경이 원활한 기준조도에 맞도록 LED 조명을 디밍 하여 작업환경을 개선하였다.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.41-47
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• 2012

The purpose of this study was to determine optimum condition for the cultivation of Chlorella sp. FC-21 using red light emitting diodes (LED). Specific growth rate and cell concentration were measured for the reactors at the illuminations of different light intensity of red LED. Under the illumination of red LED, specific growth rate increased as light intensity increased but cell concentrations decreased. To determine beneficial effect of aeration to cell cultivation, micro-air bubbles were aerated at 0.7 vvm in the reactor at the illumination of red LED. Two and ten times greater specific growth rate and cell concentration were obtained when aeration was applied. In case of blowing of carbon dioxide, pH of culture medium decreased below to pH 3, which resulted in decreases of cell concentration. From this study, we found that red LED with aeration were the most appropriate light source for the cultivation of Chlorella sp. FC-21.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.1-10
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• 2016

A system which provides multispectral near-IR and visible gray images of objects is constructed and an algorithm is derived to acquire a natural color image of objects from the gray images. A color image of 24 color patches is obtained by recovering their CIE (International Commission on Illumination) LAB color coordinates $L^*$, $a^*$, $b^*$ from their gray images using the algorithm based on polynomial regression. The system is composed of a custom-designed LED illuminator emitting multispectral near-IR illuminations, fluorescent lamps and a monochrome digital camera. Color reproducibility of the algorithm is estimated in CIELAB color difference ${\Delta}E^*_{ab}$. And as a result, if yellow and magenta color patches with around 10 ${\Delta}E^*_{ab}$ are disregarded, the average ${\Delta}E^*_{ab}$ is 2.9, and this value is within the acceptability tolerance for quality evaluation for digital color complex image.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.548-561
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• 2020

Paecilomyces japonica is widely cultured to produce mycelium for medicinal and health food use. Illumination is an important factor in the growth and production of mycelium in submerged culture. The effects of different light-emitting diode (LED) combinations on the growth and cordycepin content as bioactive substances of mycelium were investigated. The results showed that the mycelium dry weights were lower under dark condition and red LED treatments. Dark condition, fluorescent light, and ultraviolet-A failed to increase the cordycepin content. Blue light was necessary to increase the cordycepin content, and a red-to-blue ratio of 3:7 induced the highest cordycepin content. The cordycepin contents of mycelium in submerged culture were significantly higher in a 12 h/day illumination time under red and blue (red-to-blue ratio of 3:7) LED treatments, showing an increase of up to 38% compared with those under the fluorescent-light control condition. The results demonstrated the roles of light with different wavelengths on the biosynthesis of cordycepin as bioactive substances. The low-heat release and replacement of traditional fluorescent lights with low-energy-consuming LEDs could increase the contents of bioactive substances. After optimization of the cordycepin production using response surface methodology (Box-Behnken design) to its canonical form, the optimum combination was found to be as follows: illumination time = 17.7 h/day, sugar content in the medium = 9.7 g/50 mL, and incubation time = 61.2 h. The model predicted a maximum response of 3779.2 ㎍/mL cordycepin yield.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.19-19
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• 2009

Recently, Light Emitting Diode(LED) has many advantages in comparison with conventional light sources; low power consumption, long lifetime, and less environmental pollution. Therefore, the use of LED is multiplying and increasing rapidly. In general, however, spherical lens is used in LED-lighting which cause many problems induces by optical aberration of spherical lens; low illumination, a yellow belt, unpleasant feeling in human eye. As a potential solution of this problem, aspherical lens can be employed. This study reports the improvement of LED-lighting performance by adopting aspherical lens. From the commercial program, $LightTools^{TM}$, the optical problem were ensured. And then, to improve this problem, optimum aspheric form was designed using Code $V^{TM}$.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.107-109
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• 2007

LED is expected as an environmentally friendly light source with its good reliability and long lifetime. A few ten mW white LED can substitute for the indicator light source, and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lamps. Since the optical technology used for several mW white LED light source uses only 30% to 50% of the light, it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.717-721
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• 2008

This paper proposes an image system that can efficiently measure the spectral reflectance of a scene using RGB cameras and LED light sources. Multispectral imaging system is composed of LED controllers, LED clusters and RGB cameras. It captures full-spectral images at real-time. The system adopts a simple, empirical linear model to estimate the full spectral reflectance at each pixel. Since the model is linear, the reconstruction is efficient and stable. We estimated the spectral reflectance of various scenes using the system and showed the effectiveness of the proposed system.

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.201-206
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• 2014

LED lighting,considered to be a new growth industry, has attracted a great deal of attention due to its higher illumination and longer life time than existing light sources. In this study, high-efficiency and long-life LED fog lamps for automobiles were developed, which can substitute the existing 27 W halogen fog lamps for a used car market. For this purpose, the number of LED modules, the body, heat sink, and the output of the fog lamp were first optimized through a numerical analysis. Then, a 10 W-class LED fog lamp was prototyped based on the optimized numerical model, and the performance of the fog lamp was successfully verified through the experiments.

• 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.

• Electronics and Telecommunications Trends
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• v.23 no.5
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• pp.32-39
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• 2008

반도체 LED가 조명 인프라를 바꾸는 신성장 기술로 급부상하고 있다. LED는 백열전등에 비하여 전기 절감 효과가 높고, 형광등에 비하여 수은을 사용하지 않아 친환경적이다. 통신 및 조명 환경 변화에 부응한 기술로서, LED 조명과 동시에 통신을 할 수 있는 가시광 무선통신 융합 기술이 등장하였다. 본 고에서는 조명과 통신의 전혀 다른 산업이 융합된 기술로 탄생하게 된 기술적 배경, 가시광 무선통신의 국내 및 국제 표준동향, LED 조명통신 융합 기술에 의한 융합 서비스를 설명한다. 가시광 무선통신 기술은 눈으로 확인하는 통신, 빛 색에 따른 선별통신, LOS 통신 보안을 보장해주는 것이 특징이다. 또한, 조명통신 융합에 의해 광 ID, 광센서, 초정밀 실내 측위, M2M 등의 신규 융합 서비스도 제공할 수 있다.