• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.71-76
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• 2007

본 논문에서는 고 연색성의 실시간으로 색온도 제어 가능한 승강기용 조명제품 개발을 위하여 제품에 사용될 LED Package를 제작하고 고연색성 실현을 위한 색온도 제어 기초실험을 행하였다. 그리고 20W 급의 LED 광원모듈 구동회로와 색온도 제어를 위한 제어회로를 설계하였다. 또한 음영 제거 및 글레어 차단, 효과적인 광색혼합을 위하여 확산배광을 달성하기 위한 R, G, B, A, W LED의 최적 배치 및 렌즈의 광학설계를 수행하였고 LED에서 발생하는 열을 효과적으로 발산하여 LED 조명모듈의 온도를 낮추기 위한 방열설계를 실시하였다.

• Journal of Korea Multimedia Society
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• v.7 no.10
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• pp.1370-1377
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• 2004

The still image and video of the same scene taken under various condition show different color, and the most important factor of capture condition is scene illuminant. The average color of contents is determined along the color temperature of scene illuminant, the method for conversion of scene illuminant chromaticity is needed. In this paper, the method for converting the scene illuminant chromaticity from arbitrary correlated color temperature to another arbitrary one is proposed. Conventional method only defines several set of color temperature conversion that can be evaluated as representative ones. The proposed method has the merit of calculating the conversion function directly from arbitrary color temperature to another one.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.757-762
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• 2015

This paper examine how CCT affected to writing task performance and EEG through 24 elementary students from in July to September, 2014. The study analyzed EEG that was changed in a task performance under an orange color light and a white color light in a laboratory for stabilization and relaxation. The study results showed that an alpha wave, beta wave, high-beta wave were high under the white color light. The task performance time, however, showed significant fast performance under the orange color light. Although pre-existing low CCT has been considered as typical type for stabilization and relaxation, this study provides that the various applications in the elements of cognition, tasks, and types can affect improvement of task performance and occupation ability.

• Science of Emotion and Sensibility
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• v.4 no.2
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• pp.63-68
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• 2001

We purpose to evaluate the fatigue of the error correcting task on monitoring with color temperature 2700 K, 4000 K and 6500 K. Results of questionnaire on subjective feeling of visual fatigue, mental fatigue and concentration. Visual fatigue and mental fatigue level were the lowest, concentration level was the highest and working performance was the best at 2700 K. At 6500 K, mental fatigue level was the highest and concentration level is the lowest. At 4000 K, visual fatigue level was the highest and working performance shown the worst ratio of correcting answers. As results, color temperature 2700 K is the best condition of color temperature to perform the error correcting task on monitoring.

• The KIPS Transactions:PartB
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• v.18B no.3
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• pp.139-146
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• 2011

The color correction is the important process of influencing on the picture quality of the 3D stereoscopic images. Existing colorcorrecting methods handle the processing intensifying a correspondence among a left and right image using a histogram based on any one side. In case of color correction based on a histogram, it is difficult to correct tone of image, because the color temperature is not converted enough. And in this paper, the color temperature correction and color consistency correction is proposed without using histogram. The proposed color correction method by color temperature gives 3 in CIE-${\Delta}E$ for each pixel on the images captured with same illuminants and the conventional gives similar results. For color consistency, the proposed gives 9 in CIE-${\Delta}E$ on the images captured with different illuminants while the conventional gives 18. The proposed method shows better results than the conventional in color consistency processing.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.705-708
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• 2000

일반적인 LCD의 색 재현 특성은 입력 디지털 값이 낮을수록 gray scale의 상관색온도가 상승하여 정확한 색 재현이 불가능하다. 본 논문에서는 LCD의 입력 디지털 값의 변화에 따른 특성을 조사하고, luminance, contrast 비 등의 특성에 열화없이 gray scale의 입력 잘 변화에 따른 상관색온도의 변화를 보정하기 위해서 입력 디지털 값을 조정하는 새로운 LUT를 제안하였다.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.1-8
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• 2001

In this paper we propose high performance system with reduced hardware architecture to convert a color tone. Conversion for the color tone of a input image is necessary to calculate the color temperature of the image Conventional way of calculating the temperature uses algorithm using the method calculating 2-D chromaticity coordinates. But it requires bulky hardware[1]. This paper propose the color temperature calculation method about 1-D chromaticity coordinates that reduces the hardware complexity while keeping the performance of the 2-D color temperature algorithm . The proposed method is verified by fLCD-TV system using the Xilinx Virtex FPGA XCV 2000E-6BG560 that has 1344*806 resolution and requires a high-speed 65MHz operation.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.248-254
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• 2009

The aim of this study is to optimize the light source combination which can maximize the capability of the illuminance and color temperature of circadian lighting apparatus. To achieve this goal, the circadian lighting apparatus was consisted of two different types of fluorescent lamps having different color temperature of 2000K and 8000K, respectively, and the capability of the illuminance and color temperature of circadian lighting apparatus was evaluated by optical simulation as the number of the respective lamps were varied. Considering the Kruithof's curve and exceptional cases, the ranges of illuminance and color temperature for the living activities were reclassified in 4 groups - gathering, studying, relaxing and sleeping - so that the target range of illuminance and color temperature of lighting apparatus was settled. As a result, in the case of adopting two fixtures in which four 2000K lamps and five 8000K lamps were consisted, respectively to one fixture, the highest illuminance was expected at 4000K and over 500lx of illuminance was calculated between 3000K and 6000K. Through the optimized combination of light sources, the range of illuminance and color temperature were calculated as $44{\sim}750lx$ and $2500{\sim}6500K$, respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.157-160
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• 2008

색온도 및 광색 가변형 100W RGBY LED 투광기를 개발하기 위하여, 투광기의 광학 및 방열기구를 설계하였다. 또한 100W LED 광원모듈을 구동하기 위한 구동회로와 색온도 및 광색 가변을 위한 제어회로를 개발하였다. 이와 같은 설계결과를 적용하여 100W RGBY 투광기의 시제품을 제작하였고, 시제품의 광학적 성능은 협각 $20^{\circ}$, 중각 $50^{\circ}$, 광각 $75^{\circ}$이상을 만족시켰다. 또한 색온도의 변화는 CIE 1931 색좌표에서 흑체궤적과 일치하여 $2,000K{\sim}10,000K$까지 변화하도록 R,G,B,Y LED의 Duty Ratio를 설정하였다. 또한 방열 특성은 100W 구동시 녹색 LED의 온도는 $37{\sim}41.3^{\circ}C$, heatsink의 온도는 $34{\sim}35^{\circ}C$에서 동작되도록 하였다.

• Science of Emotion and Sensibility
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• v.9 no.4
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• pp.341-351
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• 2006

The effect of color evokes a certain feeling and affects behavior. Especially, an understanding and applying color are critical because well-designed color substantially contributes to quality and usability. In this study, the effects of three color components(hue, value, and chroma) on apparent warmth were investigated separately and relatively, and then feasibility of applying to the information display was examined. The result showed that the apparent warmth of 10 Hues was a U-shaped function declining from Red to Purple-Blue and increasing from Purple-Blue to Red-Purple with following order of color-circle. Chroma made the character of hues remarkably clear, so warm color becomes warmer and cool color becomes cooler if chroma gets higher. But value has no effect on warmth. These results propose that we can change the apparent warmth by varying chroma in the limitation of color use. And there was a sharp distinction between warm and cool color, Meanwhile, in the reading task of the graphical information, the subjects' judgment distortion overestimating or underestimating the actual degrees was ascertained. This result should be applied to control operator's sensitivity in accordance with the purpose of task and display.