• 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 Astronomy and Space Sciences
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• v.15 no.2
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• pp.321-333
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• 1998

In order to derive the UV color - effective temperature relation, we calculated the effective temperature and ultraviolet color index for about 118 IUE standard stars. Using differential correction method, the effective temperature was obtained by the best fittings of IUE low-dispersion spectra to the Kurucz model (1993), and the UV color index was calculated from the magnitude differences of the UV wavelength between 2750 $\AA$ and 2950 $\AA$. The temperature determined by the Kurucz model fittings was consistent with that obtained by other investigators (Malagnini & Morossi 1990, Malagnini et al. 1986), except for the low temperature stars. The relations between UV color - effective temperature also was similar to that in Kurucz model.

• 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.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.186-189
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• 2001

본 연구에서는 2종류의 색온도(4000 K, 2700 K)조건 하에서 작업자의 피로도를 평가하기 위하여 피험자에게 검색작업을 부가하고 주관평가 및 생리신호를 측정하였다. 주관평가는 ME(Magnitude Estimation)법의 설문지를 사용했으며, 생리신호는 ECG, 맥파, 피부전도도, 피부온도, 호흡, 뇌파를 측정하여 그중 ECG신호를 분석하였다. ECG신호 파라미터로서 IBI, BPM, 평균 BPM, LF/HF, CSI, CVI, CV-RR를 분석한 결과, 특히 CSI, CVI, CV-RR가 피로도와 상관관계가 높았다.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.451-459
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• 2006

Color reproduction of small LCD display is quite different from that of standard CRT due to the difference of physical, electrical, and optical characteristics. In this paper, we propose a simple and practical method using gamma and CCT correction for improvement of color reproduction on a small LCD display. First, we investigate characteristics of a small LCD display such as brightness, uniformity, color temperature, white and black balance, and nonlinear gamma. And, we also analyze color reproduction region and CCT trajectory according to LCD's input levels. Finally, the optimum gamma and CCT compensation method using LUT is proposed, and our proposed method was realized at mobile phone without hardware modification. In the experimental results, the result image of proposed algorithm is more close to standard color.

• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.91-100
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• 1998

Color indexes and effective temperatures for 25 standard stars have been determined as a pilot project which show a relationship between color index and effective temperature in ultraviolet region. The effective temperature was determined by comparing energy distribution curves derived from the IUE low dispersion spectra with Kurucz atmosphere model. The UV color index was deduced by integrating fluxes in $300{\AA}$ interval of the IUE low disperion spectra. The relation between color index and effective temperature in ultraviolet is similar with that of optical region.

• 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.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.49-57
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• 1991

A simple system to measure the correlated color temperature ($T_c$) and color rendering index ($R_a$) oflight sources was developed. And the T, and R, of incandescent lamps (I/L) and various fluorescent lamps(F/L) were measured with varying source voltage and power frequency. As results, $T_c$ variations of I/L and F/L with varying source voltage were relatively large, but $R_a$, variations were small. And $T_c$, $R_a$, variations of F/L under 5OkHz of power frequency were small, but over 50kHz, it is supposed that $T_c$, and $R_a$, will vary significantly.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.262-263
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• 2008

LCD 디바이스는 그 동작원리와 전기-광학적 특성에 의해 CRT와는 다른 감마곡선 특성을 갖고 있다. 대부분의 LCD디스플레이 디바이스들의 감마곡선은 CRT와는 달리 일관성을 갖지 않을 뿐 더러 흑백계조입력을 기준으로 하는 감마보정을 위해 RED, GREEN, BLUE 입력값을 세부적으로 조정할 때 각 계조입력에 대한 상관색온도가 일정한 값을 갖지 않아 LCD의 특성에 대한 모델링과 보정에 어려움이 있다. 또한, 애플사의 맥머신 그리고 실리콘 그래픽스사의 시스템과 같이 소정의 감마값을 전제로 해당 시스템의 내부참조테이블(internal look-up table)이 설계되어 각기 다른 시스템감마를 가지는 장치들에 의해 인코딩되어진 영상출력신호의 경우, 동일한 시스템을 갖추거나 시스템감마에 대한 역감마특성을 가진 디스플레이장치가 아닌 환경에서는 원본영상에 대한 왜곡은 더욱 커질 수 있다. 특히, 낮은 흑백계조입력에서의 색온도의 경우, 파장에 따라 서로 다른 감쇄성능을 가진 일반적인 컬러필터의 특성에 의한 누설광(light leakage)에 의해 결정되며, 이로 인해 색온도가 특정한 객을 띄는 현상이 발생한다. 본 논문에서는 LCD디스플레이의 감마곡선을 여러 가지 시스템감마에 대응할 수 있는 감마곡선예 일치시키고, 계조선형성을 동시에 개선하기 위하여 입력 디지털값과 삼자극치간 관계를 나타내는 여러 가지 컬러모델링 방법 중에서 PLCC(Piecewise Linear Interpolation assuming Constant Chromaticity coordinates)모델을 적용하고, 목표로 하는 감마곡선과 색온도를 만족하기 위한 새로운 입력값을 구한 후 이를 컬러참조테이블(color look-up table)예 적용하는 방법과 저계조에서의 색온도를 목표색온도에 근접시키는 방법을 제안한다.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.25-29
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• 1999

Time-temperature indicators (TTI) from three different companies obtained and were attached to food packages materials to evaluate degree of their color change according to storage time and temperature. Five temperature (-10 -5, 0, 5 and 10) was selected to represent standard freezing, refrigerating and room temperature, and evaluated performance by color change based on magnitude of color change and hunter system (L, a, b). Response end point was measured and recorded to find characteristic of each indicator. Comparison and discussion were conducted for accuracy and precision of each time-temperature. More research should be conducted at variable temperature and with various food to determine applicability of TTI on various storage condition.