• 한국의류산업학회지
• /
• 제3권1호
• /
• pp.31-34
• /
• 2001

The color difference values of dyed fabrics with colorant in Eucommiae Cortex were as follows; One hour of dyeing depending on pH at $95^{\circ}C$ exhibited colors of dark brown, light brown, light beige and grey. The colors of wool, nylon and silk was darkest brown at pH 3 but light brown or yellow as pH increased. In all dyed fabrics the color was changed to darker brown as time prolonged, however; there was no further color change and value and chroma of wool declined. At pH 3, the increase in temperature turned colors of all dyed fabrics into dark brown from light yellow. As the result of repetitive dyeing, colors of all dyed fabrics gradually turned into darker brown. The methods of mordant resulted in color changes between light yellow and dark brown without various color changes.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제29권3호
• /
• pp.29-36
• /
• 2023

Purpose: The purpose of this study is to find out whether the color change of the LED light source has a significant effect on the beta wave activity of EEG in the learning state. Methods: The subjects of the experiment were 20 male and female college students between the ages of 19 and 25 who routinely perform their studies. In the created learning environment, the EEG change according to the change in the lighting color was measured while solving the Mensa thinking ability problem while sitting on a desk with LED lights installed on the top and a chair with a footrest to stabilize the legs. The light source consisted of 3 ready-made colors and 6 newly created colors. A total of 9 color light stimuli were given for 2 minutes each, and the EEG change of the subject was observed. After the experiment, the correlation was analyzed based on the mid-beta wave data recorded on the QEEG according to the color change of light and the Mensa problem score. Results: It was found that the activation of mid-beta waves was stimulated in the temporal lobes (T5, T3, T6, T4) and occipital lobes (O1, O2) of all subjects who focused on solving Mensa thinking problems. As a result of comparing the top 20% and the bottom 20% of problem solving scores, the upper group had no effect of lighting, while the lower group showed increased beta wave activity in response to color light stimulation in the order of T4, T6, and T5. Implications: It was confirmed that the color of light that activates the middle beta wave varies greatly depending on the subject's attention and learning ability, and it is judged that the color of light including the green wavelength is helpful in activating the middle beta wave in the group with low learning ability.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권11호
• /
• pp.2160-2174
• /
• 2011

In this paper, a new technique for color reproduction based on color variation characteristics of digital camera under a dim light condition is proposed. Generally, photographers should adjust a camera exposure properly for obtaining an image with real color tone of subjects. Thus, in case of taking a picture under a dim light condition, the exposure time of a camera has to be relatively longer than the one under a bright light condition. Although images with real color tone of the subject are obtained, the images may get blurred due to the shaky hands of photographer holding the camera. In order to avoid the blur effect, an input image is captured from a camera set as a short exposure time under a dim light condition. Then we propose a method to reproduce color tone of the dim input image. To this end, color variation characteristics which represent color variations of a digital camera are first extracted by analyzing the Macbeth color checker images taken under various exposure values. Then, a color reproduction is performed by an estimation based on the color variation characteristics. Experimental results have shown that the proposed method has achieved better performance of color reproduction, compared with existing methods.

• 한국의류산업학회지
• /
• 제8권6호
• /
• pp.721-726
• /
• 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.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권3호
• /
• pp.365-371
• /
• 2001

The effects of light exposure and light intensity on surface color of Hanwoo (Korean native cattle) beef and color stability of fresh normal and DFD (dark, firm, dry) muscles during 7 days at $4{\pm}1^{\circ}C$ under three display conditions (Dark, Light1000 and Light3000) were investigated. The $L^*$, $a^*$, $b^*$, $C^*$ values and R630-R580 were significantly (p<0.05) higher in normal beef than in DFD beef. The $a^*$, $b^*$, $c^*$ values and R630-R580 of normal beef increased during the first day of display except Light3000 group, then gradually decreased over time. The surfaces of Hanwoo beef accumulated more metmyoglobin in the light than in the dark. Also, the rate of decrease in redness during refrigerated storage was enhanced by light exposure and increase in light intensity. Discolorations were more rapid in DFD beef than normal beef. Increasing light intensity promoted not only discoloration but also lipid oxidation. Therefore storage in the dark is effective in retarding the formation of a brown color in Hanwoo beef.

• 조명전기설비학회논문지
• /
• 제25권11호
• /
• pp.1-13
• /
• 2011

The purpose of this study is the realization of LED light environment closely resembling the Autumn daylight which people feel comfortable with. This research was conducted through an optical experiment and Emotional evaluation through human's eyes. Human beings are affected by the color of light, quality and light intensity. Unlike the past when human beings have worked mainly in daylight, the urbanites today spend most of the time in indoor spaces. Therefore, the artificial light is needed to strive toward a spectrum of daylight. This study is purposed to provide the pleasant light environment for human beings and build its database. This study course is expected to contribute to the new design methodology of the related fields under the development of the LED emotional lighting color.

• 전기학회논문지P
• /
• 제58권2호
• /
• pp.142-147
• /
• 2009

Conventional HP(high pressure) sodium or Metal-halide lamps have a life span of around one year requiring at least annual replacement and maintenance. High Power LED lights require no regular maintenance further increasing savings on replacement bulbs, access equipment and labour costs. New installations benefit from a substantial reduction in the cost of expensive heavy duty cable required for sodium lighting. Especially, LED light can achieve variable color temperature, high functional performance in the field of street light. There are two main method to achieve variable color temperature function of the street light. one method is using RGB multi-chip LED, the other is using Orange-White LED method. In this paper, it was compare RGB Multi-chip LED with white-orange LED for there characteristics performance.

• 방송공학회논문지
• /
• 제21권4호
• /
• pp.538-551
• /
• 2016

방송 제작현장에서는 영상 이미지 표현의 광원으로 Tungsten Halogen 광원이 주 광원으로 사용 되어 왔다. Tungsten Halogen 광원은 그동안 개발된 다른 광원보다 태양광원과 유사한 색 재현성으로 각광받아 왔지만 에너지 효율성의 문제점을 가지고 있었다. 최근 대체 광원으로 고효율의 에너지와 긴 수명의 LED광원이 방송 광원으로 주목받기 시작했다. LED광원은 독특한 발광원리 때문에 카메라를 통한 영상 이미지의 색 재현성과 광원에서 투사되는 빛의 질에 있어서 Tungsten Halogen광원과 다른 특성을 가지고 있다. 이런 특성은 LED광원이 방송 광원으로서 도입이 늦어지는 이유이다. 이에 본 연구에서는 LED 광원의 색 재현성과 빛의 질 특성인 평탄도를 측정하여 기준광원인 Tungsten Halogen과 비교하여 방송 광원으로써의 적합성에 대한 실험 데이터를 제시할 것이다. 또한 LED광원이 방송 광원으로서의 확산되기 위해서 필요한 점이 무엇인지 향후 과제와 기준을 제시하고자 한다.

• Journal of the Optical Society of Korea
• /
• 제14권4호
• /
• pp.415-419
• /
• 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.

• 한국의류학회지
• /
• 제31권5호
• /
• pp.801-812
• /
• 2007

In this research, 128 stimuli of same-color coloration of lipstick and clothing were evaluated to the degree of harmony in the coordination of makeup and clothing color depending on the combination of eyeshadow color, lipstick color, lipstick tone, clothing style, and clothing tone. As to the brown eyeshadow, vivid lipstick and vivid, dull clothing, dull lipstick and light, dull, dark clothing, dark lipstick and dull, dark clothing among the combinations of red lipstick and clothing, vivid lipstick and vivid, light, dark clothing, dull lipstick and light, dull, dark clothing, dark lipstick and dark, clothing among the combinations of orange lipstick and clothing were evaluated as harmonious coloration regardless of the clothing style. As to the violet eyeshadow, vivid lipstick and vivid clothing, dull lipstick and light, dark clothing, dark lipstick and dull, dark clothing among the combinations of red lipstick and clothing, vivid lipstick and vivid, dull clothing, dull lipstick and vivid, light, dull clothing, dark lipstick and vivid, dull, dark clothing among the purple lipstick and clothing were evaluated as harmonious coloration regardless of the clothing style. Thus, the degree of harmony cannot only be different according to the clothing style even in the same coloration, but also the same clothing style can be perceived to be different degree of harmony depending on how the color and tone of clothing and lipstick are coordinate.