• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.513-518
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• 2014

Purpose: This study was to investigate color distortion by colors and luminous transmittance of lenses with word-color test included in computerized neurocognitive function test (CNT). Methods: 32 subjects aged $21.97{\pm}1.58$ years with no ocular disease and color vision deficiency were selected. Four colors of tinted lenses, which were red, green and blue included in the primary colors of light and pink, and word-color test in CNT to evaluate changes in cognitive function by color distortion were used. Results: Response time was not significantly increased in green, blue, and pink among four colors, but significantly increased in only red color. And response time was significantly increased below 46% of luminous transmittance in red color. Conclusions: It should be cautious and careful of the red-tinted lens choice because red color with below 46% of luminous transmittance can distort colors of objects, and it could be related to safety problem. It is suggested that word-color test could be extensively used for further studies on color recognition.

• Korean Journal of Materials Research
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• v.22 no.12
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• pp.669-674
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• 2012

Yellow phosphor dispersed color conversion glasses are promising phosphor materials for white LED applications because of their good thermal durability, chemical stability, and anti-ultraviolet property. Six color conversion glasses were prepared with high Tg and low Tg specimens of glass. Luminous efficacy, luminance, CIE (Commission Internationale de l'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) of the color conversion glasses were analyzed according to the PL spectrum. Color conversion glasses with high Tg glass frit, sintered at higher temperature, showed better luminous properties than did color conversion glasses with low Tg glass frit. The characteristics of the color conversion glass depended on the glass composition rather than on the sintering temperature. The XRD peaks of the YAG phosphor disappeared in the color conversion glass with major components of $B_2O_3$-ZnO-$SiO_2$-CaO and, in the XRD results, new crystalline peaks of $BaSi_2O_5$ appeared in the color conversion glass with major components of $Bi_2O_3$-ZnO-$B_2O_3$-MgO. The characteristics of CIE chromaticity, CCT, and the CRI of low Tg color conversion glasses showed worse color properties than those of high Tg color conversion glasses. However, these color characteristics of low Tg glasses were improved by thickness variation. So color conversion glasses with good characteristics of both luminous and color properties were attained.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.83-86
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• 2002

This paper presents a new self-erasing discharge mode for the improvement of luminous efficiency and color purity of an AC plasma display panel (AC PDP). A new self-erasing discharge mode is produced between successive sustain pulses. by simultaneously applying the auxiliary short pulses at the falling edge of the sustain pulses without cross-talk during a sustain period. As a result. the luminous efficiency and color gamut are improved by 16% and 5%, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.54-62
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• 2013

In this study, a mock powder room was installed with variable LED lighting environments in order to conduct the experiments. The experimental conditions include luminaire type, illuminance ratio, vertical illuminance and color temperatures. The evaluation methods used were the Semantic Differential Method and a subjective evaluation on activities through observation. The SD evaluation result factor analysis categorizes ideas into three factors: brightness, emotion, and glare. The vertical bracket or the combined luminaire (luminous panel+ Vertical bracket) has better brightness than luminous panel. A vertical illuminance of 500lx is not significantly difference as compared to 600lx, allowing 500lx to be considered standard. The emotional atmosphere is evaluated as being better at lower color temperature. The luminous panel is the best for reducing glare while the vertical bracket is the worst. The best conditions differ according to the illuminance ratio of the luminous panel and vertical bracket. In the subjective evaluation (satisfaction with lighting environment, suitability to activity) the combined luminaire and 4000K received the best evaluation.

• KIEAE Journal
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• v.15 no.2
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• pp.37-43
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• 2015

Purpose: It is crucially important that indoor luminous conditions of built environments be carefully studied so as to promote comfort and occupants' well-being. Method: The current study therefore focuses on the lit aspect of an enclosed space considered to be a resting room ($4.5m{\times}6.32m{\times}2.5m$). Particularly, on the effect that light levels and light color temperatures have on the physiological and psychological responses of resting occupants. To do so, a questionnaire survey was carried out on 50 subjects. The independent variables for the experiment included 9 different luminous environment conditions setup using 3 different levels of illuminance (50 lx, 150 lx, 300 lx) and 3 different color temperatures (2000 K, 3800 K, 5600 K). A questionnaire was utilized in determining which conditions were preferred by occupants. Result: As it turns out, indoor luminous environment designed for relaxation purposes should display luminance levels of at least 150 lx and 3800 K of color temperature in order to provide a visually comfortable environment suitable for the occupant's relaxation while at the same time promoting the psychological and HRV well-being of resting occupants.

• Fashion & Textile Research Journal
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• v.8 no.6
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• pp.721-726
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• 2006

In this article I visually assessed the relation between luminous source and color, and analyzed subjective recognition of color by light source and image of color, aiming at giving guidelines in selecting source of light suitable for each purpose, thereby contributing to enhanced quality of life. For this purpose, I subjectized, by applying a quantitative method, the objective measurement that employs sensory evaluation method for 14 categories of color, light and feelings in visual perception of textile colors (blue, green and yellow) by color of light source (color temperature of 2800K, 4200K and 6500K), Followings are the conclusions derived form this study. Colors of textile were differently perceived according to the color of light source. When examining common recognition of textiles in blue, green and yellow, 2800K was said to give dirty, soft and blurred image, as for 4200K clear, wide and fine feelings were said, and pure, vivid, refined and bright image were marked for 6500K. As for 2800K, it got the most low appraisals compared with others. In conclusion, image and feeling of the same colors can differ according to light source, which indicates the importance of appropriate selection of light source for purpose of use. As for yellow, the number of assessment result that shows significant difference was the smallest among the three colors. So, it can be concluded that when we consider the recognition of color in mixing different colors, mixing with yellow can result in difficulty in visually perceiving difference of colors. Therefore, it is regarded that more considerable attention is required when dealing with yellow color.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1666-1668
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• 1997

This paper reports the optimal gas mixing ratio for color plasma display panel to improve luminous efficiency using gas dischage simulation which contains energy equation. We verified a simulation by measuring vacuum ultraviolet. The luminous efficiency has improved considerably(about 30%) by adding Ar (0.5%), compared with Ne-Xe(4%) mixing gas.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.123-127
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• 2011

To clarify the relations of optical properties to the main factors responsible for the loss and damage of luminous efficacy, a 20 min turn-on/turn-off test for 2,000 h for a ceramic metal halide lamp is conducted. The corrosion rates of the arc tube wall and electrode are estimated based on thermal stress. Wall blackening is attributed to the tungsten being transported from the hot electrode tips to the relatively cold arc tube wall. Furthermore, the grain boundaries of the arc tube are changed by the degradation. Distortion of the electrode is observed, and the ignition and the driving voltage of the load both increase. Finally, the color rendering index and the color coordinates are changed after the degradation. The luminous flux and the intensity of the luminous distribution are decreased significantly.

• Journal of Information Display
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• v.10 no.3
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• pp.97-100
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• 2009

A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.415-419
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• 2010

A phosphor-conversion white light source is demonstrated using an InGaN-based blue laser diode (LD) and a yellow-emitting phosphor excited by the blue LD. The photometric and colorimetric properties of this blue-LD-based white light source are characterized. When injection current of the LD is 100 mA, luminous flux and luminous efficiency of the white light are found to be over 5 lm and 10 lm/W, respectively. When injection current is >90 mA, luminance is estimated to be larger than 10 Mcd/$cm^2$. In addition, color characteristics of the white light such as chromaticity coordinates, a correlated color temperature, and a color rendering index are found to be quite stable as current and temperature of the LD varies. The demonstrated LD-based white light source is expected to be used in high-brightness illumination applications with good color stability.