• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.2
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• pp.39-43
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• 2010

Purpose : The purpose of this study was to analyze skin reactions induced by ultraviolet irradiation using digital imagery. Methods : We recruited 15 women and ultraviolet irradiation was applied to their lumbar area. (The degree of inflammatory reaction was set on the basis of the third erythema dose. Image analysis was divided by Photoshop CS (8 bit RGB scale and gray scale). Then, images were processes using Image Pro Plus 4.5 program analyzing R, G, B, chromatic red value, luminance value and gray value. Results : As a result of analyzing changes in RGB scale, there were statistically significant differences in R, G, and chromatic red values. As a result of analyzing changes in gray scale, there were statistically significant differences in gray value. Analysis of changes in B and luminance values showed that there was no statistically significant difference. Conclusion : This study found that ultraviolet irradiation had influence on RGB and gray scale. These results suggest that changes to digital images on skin reaction by ultraviolet irradiation are related to erythema. In particular, these changes are related to R and gray values.

• KIISE Transactions on Computing Practices
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• v.22 no.10
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• pp.532-536
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• 2016

Frame Rate Up Conversion (FRUC) generate interpolated frames between existing frames using motion estimation and motion compensation interpolation considering temporal redundancy. Falsely-estimated FRUC, however, can generate poor quality frames because FRUC typically uses blending-based interpolation method. As skipping an interpolating process between frames generate mis-estimated motion vectors, could improve Quality of Services of FRUC. In this Paper we analyze luminance histogram and motion vector consistency in frames generating poor quality interpolated frames. We conclude these features could help to be a clue in classifying the frames, which often result in the poor quality of FRUC results through the analysis and experiment.

• KIEAE Journal
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• v.4 no.2
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• pp.29-36
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• 2004

Designing outdoor lighting on landmarks has been activated in Korea since 2002 World Cup. And outdoor lighting has been important method to create nighttime activities. Especially, historic buildings which are illuminated by outdoor lighting expresses cultural beauty of the heritages in the region. Therefore, this study aims to analyze the outdoor lighting effect of historic buildings with particular reference to four historic buildings - Namdaemun, Kwanghwamun, Changanmun and Paltalmun. For the purpose, luminance of outdoor lighting are measured. Outdoor lighting of the historic buildings were mainly illuminated by the floodlights. In addition, up-lighting and accent lighting were used for expressing the bracket structure. Basements and rooflines are emphasized by floodlighting, and they represented the night image of historical buildings. For the subjective evaluation on the outdoor lighting of historic buildings, outdoor lighting images of four historic buildings - Namdaemun, Kwanghwamun, Changanmun and Paltalmun were photographed. Questionnaire surveys were conducted by hundred and twenty university students of architectural department And collected papers were statistically analyzed by SPSS. Factors that shows outdoor lighting images of historical buildings are as follows; atmosphere, clearness, intimacy, modelling. On the question of general impression of outdoor lighting, Kwanghwamun has got the most satisfactory responses and the next is Changanmun and Namdaemun, Paltalmun. Major variables which related to the 'general impression' of outdoor lighting for historic buildings have been 'dignity', 'match', 'elegance', 'beauty' in the order.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.111-116
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• 2005

This study examined the luminance and light appearance about 14 flood lighting established bridges of 26 Han River bridges and then analyzed the result through questionnaire and so on. Through this result, we looked out for new direction of analysis research for flood lighting that consider the problem of optimum brightness and light appearance harmony at flood lighting presentation, proposed to be utilized concretely in lighting design guideline for Han River bridge.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.1-7
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• 2015

Road lighting is designed with a goal of achieving the related standards on luminance, uniformity ratio and glare. Unless the luminaire with LID which is perfect for road conditions is used, a situation which fails to meet lighting standards may occur. The study examined the relationship of maximum spacing with average road luminance and longitudinal uniformity. Based on the result of the analysis, this study evaluated luminaire with what characteristics are suitable to achieve lighting requirements of the roads and suggested methods of selection for luminaires depending on the size of the road.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1569-1572
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• 2007

A two-dimensional fluid simulation code has been developed in order to investigate discharge phenomena and to improve plasma luminous efficiency in a Hg flat fluorescent lamp (FFL) for an LCD backlight unit. In this study, the method of a two-dimensional fluid simulation for FFL is explained and the simulation results of Hg-Ar-Ne mixture gas are presented for the enhancement of the luminance efficiency. The effects of various parameters, such as driving voltage, frequency, and gas mixture ratio, are investigated. The luminance efficiency increased with increasing fraction of mercury but the increasing fraction of argon did not affect the efficiency much.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.671-674
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• 2006

Due to the stricter requests of the human perception of images, many industrial standards such as TCO'03 have been made to survey the Flat Panel Displays (FPD) nowadays. The angular-dependence luminance uniformity is an important item to evaluate the performance of FPD. In this article, we focus on the above test item base on TCO'03 standard in the case of vertical direction of ${\pm}15^{\circ}$. With controlling the driving voltage toward the liquid crystals of TN-type TFT-LCD, there exists a voltage-driving range which can achieve the value of the $L_{max}/L_{min}$ at ${\pm}15^{\circ}\;{\leq}1.7$ readily. Both experiment and simulation have been well analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1650-1655
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• 2012

AC-PDPs have recently achieved good performance and their image quality can sufficiently compete with the LCD TV. However, it is necessary more effort to improve the luminance and luminous efficacy in the PDP technology. The gas mixture ratio plays a very important role in discharge characteristics, but the mechanism of gas discharge is complex and complicated. In this paper, we investigate the mechanism of gas discharge with Ne+Xe miture ratio through zero and two dimensional fluid simulation.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.27-28
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• 2000

We examined ($He_x-Ne_{l-x}$)-Xe gas discharge in an AC PDP cell by computer simulation to understand the gas mixing effects. The breakdown and sustain voltage were significantly lowered with the addition of Ne into He-Xe. The luminance and efficiency in ($He_x-Ne_{l-x}$)-Xe also improved when compared with the He-Xe or Ne-Xe gas mixture. The luminance is maximum around $30{\sim}40%$ He addition, while the efficiency shows peak values at 70% He. Two-dimensional numerical simulation was done to explain these results.

• Journal of Information Display
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• v.5 no.1
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• pp.7-15
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• 2004

A highly simplified backlight unit mainly composed of diffractive grating in sub-micron order imprinted light-guide plate (LGP) is proposed for edge-lit backlight unit. Optical characteristics of the imprinted LGP are examined by RCWA and the performance is verified through Monte Carlo simulation. Results show that the diffraction efficiency, luminous flux and its uniformity over the area are significantly affected by the angle of incident ray. Consequently couples of design considerations are additionally proposed to enhance luminous flux. In terms of peak luminance and out-coupling luminous flux, the experimental results are agreed well with the performance simulation. Finally, compared with optical characteristics of conventional backlight unit, we could conclude that the proposed simplified backlight unit made of diffractive grating imprinted light-guide plate is a good substitute for the conventional backlight unit.