• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.390-396
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• 2002

This paper Presents to choose number of RGB LED through optical special quality analysis of RGB LED samples and to produce ratio of RGB LED for a stable color variation and white light. Also, it is to design of a simple switching circuit using some resistances and switching transistors that is able to operate each 16 RGB LED stably, and switching control circuit base on a microcontroller that would be suitable for colors variation patterns control more than about 64 patterns and colors variation more than about 100,000 colors using ON/OFF and Duty control.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.9-15
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• 2021

It is a challenge for visually impaired people to access unfamiliar environments independently, hence the quality of life is reduced, and safety of life is compromised. An accurate and reliable door detection system comprising of way finding and indoor navigation can be beneficial for a large number of autonomous and mobile applications for visually impaired people. This paper illustrates an image-based door detection scheme for visually impaired people using stable features (edges and corners) including color averaging and image resizing. Simulation results show that the proposed scheme shows a significant improvement when compared with existing scheme.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.375-380
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• 1998

A study of characteristics of greenish pigments from silkwarm excrement by ethanol extraction. Through visible absorption scanning, it showed two absorption peaks at 415 and 657nm, and it was shown to be greenish color. In the presence of light, the stability of pigments rapidly degraded, but in the presence of Al-foil, green and blue cover were very stable. It was shown to be stabilized at the temperature of 7$0^{\circ}C$ until 20days and presence of metal ions, such as Na+, K+, Ca2+, Mg2+ and Zn2+. The pigments was shown to be stabilized in 5% acetic acid solution, but in the presence of lactic acid, citric acid and tartaric acid solution were unstable. On the result of TLC analysis, pigments were shown to be composed of eight color fractions, and main color fractions were F-1, F-2 and F-3. In F-1, F-2 fractions were revealed green color and F-3 fraction were revealed yellow color.

• Journal of Sensor Science and Technology
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• v.17 no.5
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• pp.387-395
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• 2008

An optic module system is developed adopting multiple colorimetry units for the measurement of multi-pad urinalysis dipsticks. Multiple photometry system instead of moving mechanisms has the advantages of system reliability and simplicity as well as economic aspects due to the recent development of economic color light emitting diodes and stable photo sensors. An integration amplifier with programmable integration time, a current source circuit with selectable and stable current settings were connected through analog multiplexers to thirty light emitting diodes for illumination and ten photo transistors for reading each strip pad. All the circuits are controlled by a microprocessor through a simple set of serial communication commands. The detect ability is eighteen times better than the minimum color difference of the test grading which is 0.013 in urobilinogen in the color space defined in this paper.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.506-510
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• 1996

The stability of prickly pear color as affected by pH, metal ions, sugar and acids was studied. The color of prickly pear was most stable at pH 4 and 5. Metal ions (Fe, Cu) at a level of 100 ppm caused a decrease in stability compared to that of the control, whereas pigment of prickly pear was stable at 100 ppm of Sn ion And the color of prickly pear was stable at 0.15 M fructose. Both 100 and 500 ppm ascorbic acid had the greatest effect on stability, while citric acid, phosphoric acid and tartaric acid had no effect on stability compared to that of the control. Based on the data presented, it was concluded that under selected conditions prickly pear pigment should find application as natural food colorants.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.105-119
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• 1976

Sucrose, glucose, starches hydrolyzates and raw starchy materials hydrolyzates were caramelized using various catalysis and the caramel products were analysed, in order to carry out the basic research for the replacement of caramel coloring. The results obtained were summarized as follows. 1. The caramel which was manufactured by sucrose syrup being pH 3.5 adjusted by sulfuric acid showed strong color intensity and hue as well as good stability in the solutions of table salt, tannin and alcohol. 2. The product caramelized from sucrose syrup being pH 9.5 adjusted by sodium carbonate showed very strong color intensity and black color component, and was quite stable in alcohol solution but not in table salt and tannin solutions. 3. The caramel products made from sucrose syrup using ammonium salts of strong acid like $NH_4Cl$ and $(NH_4)_2SO_4$ as catalyst showed strong color intensity and black color component but hazy apparence in solution of table salt, tannin and alcohol. 4. The product caramelized from glucose syrup being pH 9.5 adjusted by sodium carbonate indicated strong color intensity but weak red color component and was transparent in solution of table salt and alcohol but hazy in tannin solution. 5. In glucose caramel using $NH_4Cl$, $(NH_4)_2SO_4$, $(NH_4)_2CO_3$ and $(NH_4)_2SO_3$ as catalyst, $NH_4Cl$ plot was very weak in color intensity and insufficient in red color component but stable in solution of table salt, tannin and alcohol. In the case of $(NH_4)_2CO_3$, $(NH_4)_2SO_4$ and $(NH_4)_2SO_3$ plots, all products were strong in color intensity but little insufficient in red color component. On the stability in solutions, $(NH_4)_2SO_3$ plot was stable in two solutions expect tannin solution, $(NH_4)_2CO_3$ plot was only stable in alcohol solution and $(NH_4)_2SO_3$ plot was only stable in table salt solution. 6. When the acid hydrolyzed starch syrups without neutralization were caramelized using $(NH_4)_2SO_4$ as catalyst, the potato starch hydrolyzate caramel showed higher in color intensity being similar to its of glucose caramel than sweet potato starch hydrolyzate caramel and corn starch hydrolyzate caramel. 7. Dried sweet potato powder, dried acorns powders, the acorns (from Q. serrata THUNB and Q. acutissima CARR.) powders extracted with water for 7 days and with 50% alcohol solution for 24 hrs were hydrolyzed by sulfuric acid in autoclave at $3.5kg/cm^2$ as pressure for 60 mins, and were caramelized using $(NH_4)_2SO_4$ as catalyst. It was supposed that all of those products were poor quality on color and stability in solutions at the viewpoint of food coloring matter.

• 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.

• Architectural research
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• v.18 no.3
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• pp.83-90
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• 2016

Senescent effects are the gradual deterioration of function caused by biological aging. Senescent effects on color vision are not clearly understood even after considerable researches. Part of the reason is that the color vision is a complex phenomenon resulting from various factors such as organic systems, and the physical (neuro-optical) and the psychological (experiential) processes of color perception. We performed a field experiment on color perceptional differences due to aging vision. Our experiment was applied to two different groups in South Korea: an experimental group (46 subjects of over the age of 61 years) and a control group (49 subjects in their twenties). The experimental tools are comprised of (1) six gradual yellowing detector board (40%, 50%, 60%, 70%, 80%, 90%); (2) pairs of vivid-strong, vivid-deep, grayish-deep, deep-dull, and bright-light tones of Blue (B) and Purple (P) colors; (3) Red (R), Yellow (Y), Green (G), Blue (B), and Purple (P) colors of dull-tones and pale-tones; and (4) a questionnaire on the semantic differential scales of the color images and color differences. A diagnosis system of gradual yellow vision, developed by the authors for this study, was adapted to generate the color detecting boards. The results are as follows. (1) There are significant differences between the two groups in detecting colors that simulate 40% and 50% of yellow vision. (2) As to the color difference detecting ability between similar tones, the experimental group shows difficulties in pairs of vivid-strong tones and deep-dull tones of the B color. And (3), the emotional responses to the dull tone and the pale tone are not stable in the red, the yellow, blue, and purple. Thus, we empirically demonstrate the specific differences in color perception between the old and young groups.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.2
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• pp.43-52
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• 2020

With the advent of the Fourth Industrial Revolution, people need healing. Research in neuroarchitecture shows that people feel happy and stable when working with nature, and patients heal quickly. Therefore, This study aims to quantitatively analyze the colors that help psychological healing in the painting images depicting nature by setting 'Natural Colors' of Biophilic Design as the subject of research. So the purpose of this study was to measure Biophilic Color and to develop Biophilic Color Palette. We extracted Biophilic colors using Impressionist Monet's Landscape painting. After extracting colors using Photoshop Color Picker, we converted RGB color code to NCS color code and Munsell color code. The results of this study were as follows; The ratio of Y was high in the GY-series and YR-series. This is due to the characteristic of impressionism that expresses the change of color by light in close relationship with light. Y is universally considered to be pleasant, representing happiness, sunshine and optimism. Therefore, it is possible to create an environment that helps psychological healing by utilizing the Y-series color palette. Average Blackness was 28. Average Chromaticness was 34.61. The significance of this study is to propose a biophilic color palette that is useful for psychological healing by quantifying the color code of biophilic colors depicted and expressed with adjective images and idiomatic color names. Quantitative and empirical studies on healing colors are needed continuously and should be actively utilized in healing environment planning.

• 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.