• KIEAE Journal
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• v.2 no.2
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• pp.33-38
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• 2002

There are a number of practical uses for devices which are capable of piping large amounts of light: illumination of areas where there would be maintenance, safety, or security problems with electronic light sources; piping sunlight into indoor areas for illumination; and the conversion of high luminous efficacy, good color quality, high intensity discharge lamps into more acceptable linear of area sources of light. Prism light guides are hollow structures which pipe light by means of total internal reflectin(TIR). These devices are unique in their ability to combine the efficiency of TIR with the relatively low cost of hollow structure. An important application stems from their ability to transform a point source of light such as an incandescent or discharge lamp into a linear or area source of light or illumination. We report the development of an economical, flexible prismatic film for fabricating the light guide wall. This guide geometries and films are currently under development.

• Journal of the Korean Society of Costume
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• v.31
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• pp.33-46
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• 1997

The purpose of this study was to investigate color planning method for apparel fashion de-sign and to present the method of analysis of green color. Theoretical backgrouds of color planning for fashion design were scrutinized by documentary studies Fashion color planning has been developed through 4 steps: analysis of color environment analysis of color psy-chology presentation of coordination appli-cation to fashion design. Green color environment consisted of mar-ket informations and forecast informations The former were collected by color samples which were used for women's apparel of national brands from '93 spring/summer to '96 spring/summer and the latter were analyzed by fashion forecasting books. Green color psy-chology was investigated through the docu-mentary studiess. image of green color and these expressed in fashion were revealed through documentary studies. The results of this study were as follow: 1. 117 green color samples were collected from domestic womens brand. The character-istic of samples were the yellow green in hue and pale light bright in tone. forecast infor-mation was collected through fashion forecasting books from abroad and adaption of forecast information was investigated by mak-ing a comparison forecasting information be-tween market information. In consequence national market colors reflected the forecast information in concurrence with the character-istic colors of national women's apparel. 2. Affirmative images of green were nature youth health and abundance and negative images were extraordinary misfortune wind-fall. in these images nature youth and health were mostly used in fashion.

• Korean Institute of Interior Design Journal
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• v.25 no.2
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• pp.83-91
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• 2016

This study is a basic research to suggest user-centered healthcare environmental color, which aims to analyze tendency of color consciousness and preference depending on the user characteristics (generation, gender, residential area, and environment). For this purpose, this study constructed an analysis tool through the literature review with regard to environmental color of healthcare facility and influential factors of color preference. Besides, an online survey regarding general usage and satisfaction, health related color consciousness, and color preference tendency of healthcare facility was conducted targeting from 20s to 60s, total 1,500 persons. The results of this study are as follows: (1) The usage and satisfaction of healthcare facilities were higher for older generation and accessible urban area. (2) The respondents were aware that color and health are related, recognizing 'green' as healthy and stress relieving color. Besides, 'natural' and 'clear' was the highest in health related color image. 'Light' which relates to vitality was high as well for older generation. (3) In the color preference tendency survey, hue PB was generally the most highly preferred, in details, younger generation preferred B and R while older generation preferred G. The survey also showed high value and chroma were preferred, while female and younger generation preferred high value of 9.0 and low chroma close to achromatic color, which presented older generation preferred vivid color.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.475-483
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• 2015

We examined the effects of light colors (wavelength) and light quantities on the yield ratio and quality of cultivated cowpea sprouts. All light colors resulted in a lower cowpea sprout yield ratio compared to the untreated condition (darkness), but were similar in hard seed ratio. All light colors promoted the growth of the epicotyl and root when compared to the untreated condition, but limited the growth of the hypocotyl. White light (458 nm) significantly improved grade by increasing the lightness of the cotyledon and the hypocotyl and the yellowness of the hypocotyl. The Fe content of cowpea sprouts was higher in those grown under red light (632 nm), and the total amino acid content was higher for those grown under yellow light (560 nm), white light (458 nm), and blue light (460 nm) compared to plants grown in the untreated condition (darkness). The yield ratio of cowpea sprouts was lower in the yellow light condition (560 nm) at lower light quantity, but no differences were observed at other light colors and quantities. The lightness and yellowness of cowpea sprouts was higher in the yellow light (560 nm) and red light (632 nm) at lower light quantity, redness was lower. No significant differences were observed in the content of normal and inorganic components according to the light quantities of each light color, except that Fe content was higher in sprouts grown under red light (632 nm) as light quantity increased. Total amino acid content was slightly higher in sprouts grown under white light (458 nm) and blue light (460 nm) as light quantity increased.

• Journal of the Korean Home Economics Association
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• v.46 no.9
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• pp.1-6
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• 2008

The purpose of this study was to investigate the changes in the property of nylon fabrics dyed with safflower red and yellow colorants under Ultraviolet(UV)-light. For this purpose, nylon fabrics dyed with safflower red and yellow colorants were compared with each other after uv-light exposure in terms of K/S value, color changes(${\Delta}E$), morphology, and strength retention. K/S value rapidly decreased with increasing exposure time, but K/S value of the samples dyed with safflower red colorants decreased less than that of samples dyed with safflower yellow colorants. In color changes, as increasing exposure time, $L^*$ increased, $a^*$ decreased, $b^*$ increased, and so ${\Delta}E$ increased in samples dyed with safflower red colorants. In color changes, as increasing exposure time, $L^*$ increased, $a^*$ and $b^*$ decreased, and thereby ${\Delta}E$ increased in the samples dyed with safflower yellow colorants, indicating fading away by uv-light and changes of hue, value and chroma value. But the color change of samples dyed with safflower yellow colorants was less than that of samples dyed with safflower red colorants. SEM pictures showed a severe degradation by uv exposure, regardless of colorants type. Tensile strength slowly decreased until 14 days, and rapidly decreased until 28 days. Strength retention of the samples dyed with safflower yellow colorants was higher than that of the samples dyed with safflower red colorants.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.42-49
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• 2009

This paper proposes a driving current control method for a back light unit (BLU), consisting of red, green, and blue (RGB) light-emitting diodes (LEDs), whereby an RGB optical sensor is used to check the output color stimulus variation to enable a time-stable color stimulus for light emission by the RGB LED BLU. First, to obtain the present color stimulus information of the RGB LED BLU, an RGB to XYZ transform matrix is derived to enable CIEXYZ values to be calculated for the RGB LED BLU from the output values of an RGB optical sensor. The elements of the RGB to XYZ transform matrix are polynomial coefficients resulting from a polynomial regression. Next, to obtain the proper duty control values for the current supplied to the RGB LEDs, an XYZ to Duty transform matrix is derived to calculate the duty control values for the RGB LEDs from the target CIEXYZ values. The data used to derive the XYZ to Duty transform matrix are the CIEXYZ values for the RGB LED BLU estimated from the output values of the RGB optical sensor and corresponding duty control values applied to the RGB LEDs for the present, first preceding, and second preceding sequential check points. With every fixed-interval check of the color stimulus of the RGB LED BLU, the XYZ to Duty transform matrix changes adaptively according to the present lighting condition of the RGB LED BLU, thereby allowing the RGB LED BLU to emit the target color stimulus in a time-stable format regardless of changes in the lighting condition of the RGB LEDs.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.806-816
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• 2022

Purpose: In this study, the luminance measurement analysis results of the smoke generation state are considered for visual signal display light color for real-time escape guidance in the underground common area. Method: We will analyze the scattering characteristics of light in the atmosphere and optical technology based on the visibility theory, and try to classify the elemental technology as a guidance function through a prototype of a visual signal display device for evacuation guidance. Result: In the experiment conducted under the smoke-generating condition, the results were derived with low luminance ratio and good visibility in the order of red, green, and yellow. However, this result is different from general lighting in which color rendering is considered, and is limited to signals for signals and detection. Conclusion: A conclusions were drawn by reflecting both the luminance measurement results in the smoke generation situation and the preference survey results conducted in previous studies for the light color of the visual signal for signal and detection. When events such as smoke occur, it is better to use the escape guidance visual signal in red or green.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1171-1172
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• 2012

• The Magazine of the IEIE
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• v.21 no.8
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• pp.30-38
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• 1994

본고에서는 TFT LCD의 중요한 issue가 되고 있는 대형화와 full color 실현을 위해 저반사화 기술, 고개구율화 기술, 광시야각 기술 및 back light unit, color filter, 구동 IC등의 주요 핵심 부품 기술등의 최근 기술 동향 및 향후 나아갈 방향에 대하여 살펴보았다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7324-7330
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• 2014

Color distortion of the dark images acquired under a low-light-level environment with a weak light source can be cause of the performance decreation of various vision systems. Therefore, recovering the original color of the images is an important process for enhancing the performance of the system. For this, this study proposes a color restoration method using a dichromatic reflection model. This paper assumes that the dark images can be classified into two parts affected by specular or diffuse reflection. Two different color constancy methods were then applied to the images to remove the effects of each reflection and two images were created as a result. The resulting images produced a one color-corrected image by combining with different weights according to the position in the images. For the performance evaluation, this paper used a synthesized image, and considered the Euclidean distance and angular error as an evaluation factor. In addition, a performance comparison was performed with the existing various color constancy method to achieve the objectivity of evaluation. The experimental results showed that the proposed method can be a more suitable solution for color restoration than the existing method.