• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1100-1103
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• 2001

(1) By comparing and analyzing the distribution of brightness as domestic lamps and Japanese products go thinner and lighter, we set an effective design standard. (2) By comparing and analyzing the feature, brightness, chromaticity and uniformity of domestic LGPs and Japanese products, early home-manufacturing and stabilization in home-manufacturing are possible. (3) By comparing and analyzing the distribution of brightness as sheets are varied, we can design an ideal sheet composition.

• 대한원격탐사학회지
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• 제6권2호
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• pp.153-164
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• 1990

A statistical correlation between cloud thickness and brightness is shown by regression analysis using the least-square method. Cloud thicknesses are obtained from radiosonde observation. Brightness values are obtained from GMS visible channel. Regression analyses are preformed on both thickness data used in conjunction with brightness data for summer season. The results are shown by the regression curve relating thickness and brightness accounting for 79% of variance. And the relationship between thickness and precipitable water in the cloud layers is analyzed. The thickness shows a positive correlation with precipitable water in cloudy layers.

• 전자공학회논문지 IE
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• 제46권3호
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• pp.12-18
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• 2009

본 논문은 LED 디스플레이 시스템에서 균일하고 부드러운 영상표출을 위하여 각각의 Red, Green, Blue LED의 휘도를 조절하여 흰색보정을 유지할 수 있는 프로세서를 설계하였다. 이 프로세서는 일반적인 LED소자의 특성곡선을 근거로 "a"를 고유특성 값, "b"를 사용시간에 따른 휘도보정 값, "X"를 구동전류 값, "Y"를 휘도 값이라 할 때, "Y=aX+b"로 설정되는 휘도 특성함수에 의하여 각 픽셀의 휘도에 따른 구동 전류 값을 산출하여 휘도를 보정하고, 또한 장시간 사용 시 LED소자의 휘도 저하 문제를 해결하기 위하여 "b"값을 조절하여 LED 디스플레이 시스템의 전체 평균 휘도 값을 상향시킬 수 있도록 구현하였다.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.100-109
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• 1997

The objectives of this study was to decrease pollutions of bleaching effluent and was to enhanced brightness of non-chlorine bleached pulps by xylanase treatments. Xylanase cloned Esherichacoli(E. coli) capable of each of endo, exo-xylanase and acetyl-esterase were obtained from Bacillus stearothermophillus. These xylanase was maintained high activity in alkali and high temperature. Especially endo-xylanase would be more active in $60^{\circ}C$ and pH 11. Xylanase pretreatment(X) of unbleached pulp increased brightness, and decreased the degree of delignification. The degree of increase in brightness of pulp due to xylanase pretreatment was similar to non-enzyme treated pulp, regardless of the amount of enzyme added. Therefore, the addition of xylanase of 2 unit was recommended when considering costs of enzyme. The pulp bleached XO sequence had higher brightness and lower Kappa no, than O bleached pulp, while pulp bleached XP sequence had similar brightness and Kappa no. with P bleached pulp. In XOC/D, XOZ and XOP bleaching sequences, brightness and degree of delignification were improved. The C/D and Z stage bleached pulp was good effect on rate of raise in brightness and Kappa no., but P stage bleached pulp had similar level in non-enzyme treated bleaching sequence.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.161-170
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• 2015

Mean separated histogram equalization in order to preserve the original mean brightness has been proposed. To provide the minimum mean brightness error after the histogram modification, the input image's histogram is successively divided by the factor of 2 until the mean brightness error is satisfied the defined threshold. Then each divided group or sub-histogram will be independently equalized based on the proportional input mean. To provide the overall minimum mean brightness error, each group will be controlled by adding some certain pixels from the adjacent grey level of the next group for giving its mean near by the corresponding the divided mean. However, it still exists some little error which will be put into the next adjacent group. By successive dividing the original histogram, we found that the absolute mean brightness error is gradually decreased when the number of group is increased. Therefore, the error threshold is assigned in order to automatically dividing the original histogram for obtaining the desired absolute mean brightness error (AMBE). This process will be applied to the color image by treating each color independently.

• 조명전기설비학회논문지
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• 제26권10호
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• pp.16-26
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• 2012

This study conducted a subjective evaluation of brightness perception and visual discomfort according to dimming speeds and CCTs(Correlated Color Temperatures). Dimming speeds of two different CCT lights(2,700K, 6400K) were set to 1.7%/s, 3.3%/s, 5.0%/s, 6.7%/s, and 10.0%/s respectively. Subjects checked the time when they perceived the change of the brightness and visual discomfort. As a result, when dimming speeds were 1.7%/s, 3.3%/s, 5.0%/s, 6.7%/s, more than half of subjects responded the change of the brightness in 55.0~45.0% dimming ratios, and felt the visual discomfort in 35~25% dimming ratios. When the brightness was changed, dimming level responded to the brightness perception of hight CCT(6,400K) was higher about 8.0% then dimming level responded to the brightness perception of low CCT(2,700K). Dimming level responded to the visual discomfort of low CCT(2,700K) was higher about 5.0% then dimming level responded to the visual discomfort of hight CCT(6,400K).

• 천문학회지
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• 제47권6호
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• pp.303-309
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• 2014

We present results of our investigation of the radio intrinsic brightness temperatures of compact radio jets. The intrinsic brightness temperatures of about 100 compact radio jets at 2, 5, 8, 15, and 86 GHz are estimated based on large VLBI surveys conducted in 2001-2003 (or in 1996 for the 5 GHz sample). The multi-frequency intrinsic brightness temperatures of the sample of jets are determined by a statistical method relating the observed brightness temperatures with the maximal apparent jet speeds, assuming one representative intrinsic brightness temperature for a sample of jets at each observing frequency. By investigating the observed brightness temperatures at 15 GHz in multiple epochs, we find that the determination of the intrinsic brightness temperature for our sample is affected by the flux density variability of individual jets at time scales of a few years. This implies that it is important to use contemporaneous VLBI observations for the multi-frequency analysis of intrinsic brightness temperatures. Since our analysis is based on the VLBI observations conducted in 2001-2003, the results are not strongly affected by the flux density variability. We find that the intrinsic brightness temperature $T_0$ increases as $T_0{\propto}{\nu}^{\xi}_{obs}$ with ${\xi}=0.7$ below a critical frequency ${\nu}_c{\approx}9GHz$ where the energy loss begins to dominate the emission. Above ${\nu}_c$, $T_0$ decreases with ${\xi}=-1.2$, supporting the decelerating jet model or particle cascade model. We also find that the peak value of $T_0{\approx}3.4{\times}10^{10}$ K is close to the equipartition temperature, implying that the VLBI cores observable at 2-86 GHz may be representing jet regions where the magnetic field energy dominates the total energy in jets.

• 전자공학회논문지
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• 제52권2호
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• pp.141-147
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• 2015

디스플레이의 대비는 일반적으로 디스플레이 최대 밝기와 최소 밝기의 비율을 이용하여 나타낸다. 그러나 이와 같은 명암비는 인간 시각의 인지 특성을 고려하지 않고 디스플레이의 물리적 특성만을 고려했기 때문에 인지 대비와 일치 하지 않는다. 본 논문에서는 디스플레이 밝기 범위 내에서 인지적으로 구별 가능한 밝기를 고려한 대비 측정 방법을 제안한다. 먼저, 디스플레이의 인지 밝기 범위를 측정하기 위해 CIECAM02 색 공간에서 최대 밝기와 최소 밝기 사이의 길이를 계산한다. 다음으로, Weber-Fechner 법칙을 기반으로 하여 각 밝기에서 인지적으로 동일한 밝기 범위를 결정하고, 각 범위 내에 존재하는 색의 수를 계산한다. 마지막으로, 각각의 동일하게 인지되는 밝기 범위내의 색의 수와 인지적 대비 길이의 비율로 인지적으로 구별 가능한 밝기를 계산한다. 주관적 실험에서 제안한 방법은 이전의 인지 대비 측정법에 비해 주관적 인지 대비 실험 결과와 일치하는 결과를 보였다.

• 한국터널지하공간학회 논문집
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• 제15권5호
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• pp.497-504
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• 2013

본 연구에서는 도로터널 조명설계에 있어서 내부조명의 밝기 수준에 영향을 미치는 갱구부 경관을 L20법 측정을 통하여 수치 해석적으로 고찰하였다. 갱문 형식별로 휘도인자를 추출하고 갱구부 주변시설물의 재료적 특성이 미치는 영향을 평가하기 위해서 동영상 휘도계 HI-LAND ELF SYSTEM과 면휘도계 LMK Mobile advanced로 촬영하여 휘도 분석을 하였다. 국내의 터널은 대부분 산악지대에 분포되어 L20각도 내에서 휘도가 가장 높은 하늘이 점하는 비율이 거의 없으며, 터널 입구주변이나 도로노면에 의한 휘도가 대부분을 차지하고 있다. 그러나, L20각도 내에서 갱문의 면적이 넓게 보이는 면벽식의 경우는 주변이나 노면에 비해 밝은 휘도를 나타냄으로서 터널내 경계부 휘도를 높이는 요인이 되고 있으며, 터널 갱구주변의 도로시설물도 휘도에 영향을 미치고 있음을 파악하였다. 따라서, 휘도기반의 터널조명 설계 시 갱문의 형식 및 갱구부 주변시설물에 대한 면적, 재료, 색상 등이 외부휘도에 영향을 미치고 이로 인해 터널 내부조명의 밝기 레벨 설정에 영향을 주는 요인이 되므로 갱구부 경관설계 시 이에 대한 검토가 반드시 필요한 것으로 나타났다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.836-841
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• 2004

This paper describes ASIC design for brightness revision control, A LED Pixel Matrix (LPM) design and LPM in natural color LED vision. A designed chip has 256 levels of gradation correspond to each Red, Green, Blue LED pixel respectively, which have received 8bit image data. In order to maintain color uniformity by reducing the original rank error of LED, we adjusted the specific character value 'a' and brightness revision value 'b' to pixel unit, module unit and LED vision respectively by brightness characteristic function with 'Y=aX+b'. In this paper, if designed custom chip and brightness revision control method are applied to manufacturing of natural color LED vision, we can obtain good quality of image. Furthermore, it may decrease the cost for manufacturing LED vision or installing the plants.