• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.172-181
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• 2023

Dunhuang murals are one of the most outstanding achievements in the art of traditional grotto painting in China, and are known as a "Wall Museum". As a representative of the heyday of Dunhuang murals, an in-depth exploration of Dunhuang murals from the perspective of color will help researchers understand the laws and connotations of color in Dunhuang murals during the Tang Dynasty and fully grasp the art of Dunhuang murals. The color system of the traditional Chinese "Five colors" concept expresses the cultural attributes and emotions of the Chinese people and has distinctive national characteristics. This thesis provides a theoretical grasp of the traditional Chinese "Five colors" view of color system, the Dunhuang murals of the Tang Dynasty, and the color configuration of the color composition principles, and uses the modern design principles of color composition to conduct an in-depth analysis of the configuration of the Dunhuang murals' use of color. Explore the unique characteristics of Tang Dynasty Dunhuang murals, and help modern designers master richer color application techniques by learning from and studying the harmonious patterns of Dunhuang murals to provide a new path for the dissemination of excellent Chinese traditional culture.

• Current Optics and Photonics
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• v.3 no.1
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• pp.78-85
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• 2019

The remote phosphor structure has been proven to bear greater luminous efficiency than both the conformal phosphor and in-cup phosphor structures; however, controlling its color quality is much more challenging. To solve this dilemma, various researchers have proposed dual-layer phosphor and triple-layer phosphor configuration as techniques to enhance the display brightness of white LEDs (WLEDs). Likewise, this study picked one of these configurations to utilize in multichip WLEDs with five distinct color temperatures in the range from 5600 to 8500 K, for the purpose of improving the optical properties of WLEDs, such as color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE), and chromatic homogeneity. According to the results of this research, the triple-layer phosphor configuration has superior performance compared to other configurations in terms of CRI, CQS, and LE, and yields higher chromatic stability for WLEDs.

• Korean Journal of Optics and Photonics
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• v.12 no.5
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• pp.425-428
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• 2001

In this work, we propose a new optical configuration for a 3-stack color LCD using subtract color mixing method. This configuration consists of 3 color polarizers, a neutral polarizer and 3 LC cells. With the proposed configuration, we can increase the contrast ratio practically by using a neutral polarizer and reduce the manufacturing cost. To reduce wavelength dispersion, the sequence of polarizers is optimized.

• Agricultural and Biosystems Engineering
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• v.3 no.1
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• pp.35-43
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• 2002

The spectral color resolution of an image is very important in color image analysis. Two factors influencing the spectral color resolution of an image are illumination intensity and lens aperture for a selected vision system. An optimal combination of illumination intensity and lens aperture for color image analysis was determined in the study. The method was based on a model of dynamic range defined as the absolute difference between digital values of selected foreground and background color in the image. The role of illumination intensity in machine vision was also described and a computer program for simulating the optimal combination of two factors was implemented for verifying the related algorithm. It was possible to estimate the non-saturating range of the illumination intensity (input voltage in the study) and the lens aperture by using a model of dynamic range. The method provided an optimal combination of the illumination intensity and the lens aperture, maximizing the color resolution between colors of interest in color analysis, and the estimated color resolution at the combination for a given vision system configuration.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1327-1331
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• 1990

A new dual loop controller using color LCD bar graphs with LED back lights has been developed. An optional memory card is used to load or save the controller configuration, which may be a preprogrammed standard package or a user-programmed configuration, in addition to the built-in functions ready for user selection. The bar-graph display is selectable for single-loop or dual-loop use. A high grade of self-tuning functions using a modeling technique is built-in as standard. The controller can accommodate optional plug-in modules for thermocouples, communication, etc. All the options are fully field upgradable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.202-203
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• 2009

In this paper, system divide into the edge extraction, labeling, clustering, and South Korea's traditional color combination and identifying to identify Korea's traditional colors. Edge is extracted using Canny operator. And given the label, and clustering to ensure the quality of the cluster. Finally, we identify color harmony by organizing and comparing primary color with secondary color configuration table Korea traditional color.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.61-71
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• 2002

Color-code imaging should be one of the best display tools for the quick perception of both damage area and its intensity, In this study we proposed the standard color code corresponding to maximum observed acceleration value. Since the acceleration value changes with frequency contents, we suggested to limit the frequency band less than 10Hz. The background considerations of this limitation, magnitude vs. dominant frequency, natural characteristics of artificial noises and the relationship between velocity and acceleration, were reviewed in detail. The standard of color code was assigned from 0.001%g to 20%g based on the possible earthquakes at Korean peninsula and the color imaging given by RGB value was shown to be very consistent, irrespective of hardware configuration.

• Journal of the Optical Society of Korea
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• v.11 no.2
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• pp.67-70
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• 2007

A Wide Color Gamut Backlight system was studied using a three-band white Light-Emitting Diode. A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 445-nm blue peak, and a green phosphor and red phosphor that emit 535-nm green and 621-nm red peak emissions, respectively, when excited by 450-nm blue light. Using for this three-band white LED, wide color gamut backlight unit (BLU) was attained. The luminance of BLU and CIE 1931 chromaticity coordinates was $1,700Cd/m^2$ and (0.337, 0.346). Color filter matching simulations for this configuration show that the three-band white LED backlight can be enhanced by up to 16% over conventional white LED backlight color gamut.

• KIEAE Journal
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• v.14 no.1
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• pp.23-30
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• 2014

The preferred illumination environment in accordance with the actions taken by the occupants of the rooms in residences differs significantly between different cultures and circumstances in and out of the country. In this regard, the purpose of this study is to evaluate the visual performance of various illumination environments in residential spaces by allowing the participants of the experiments to select the kind of illumination environment they prefer as the occupants of the room. For this purpose, we prepared a mock-up residential space of $6.2m{\times}4.5m{\times}2.5m$, where the experiments for this study were conducted. Then, three illuminance settings (30lx, 100lx, and 150lx) and three color temperature settings (2700k, 4000k, and 6500k) were selected as the properties of the physical environment where the tests were to be conducted. The survey was conducted with 30 study subjects, with whom the level of visual comfort and the lighting adjustment evaluation by different activities were carried out. The level of visual comfort in lighting in a residential context turned to be more influenced by the color temperature and illuminance compared to other factors. Except for the test item, 'comfort,' all test items showed positive reactions when the illuminance was 150lx, which was rather light. In 'comfort,' the test subjects appeared to prefer warm color temperature of 2700k. As we allowed the occupants to adjust the lighting environment in accordance with the conditions of the subjects and the activities they performed, the subjects regarded 150lx - 4000k setting as comfortable, while they preferred 150lx-5400k configuration for working. In case of resting, the subject answered that the configuration of 30lx -2700k setting to be visually comfortable.

• Current Optics and Photonics
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• v.1 no.4
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• pp.389-395
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• 2017

This paper investigates a method to improve the lighting performance of white light-emitting diodes (WLEDs), which are packaged using two separate remote phosphor layers, a yellow-emitting YAG:Ce phosphor layer and a red-emitting ${\alpha}-SrO{\cdot}3B_2O_3:Sm^{2+}$ phosphor layer. The thicknesses of these two layers are $800{\mu}m$ and $200{\mu}m$, respectively. Both of them are examined in conditions where the average correlated color temperatures (CCT) are 7700 K and 8500 K. For this two-layer model, the concentration of red phosphor is varied from 2% to 30% in the upper layer, while in the lower layer the yellow phosphor concentration is kept at 15%. It was found interestingly that the lighting properties such as color rendering index (CRI) and luminous flux are enhanced significantly, while the color uniformity is maintained in a relatively close range to the one of one-layer configuration (measured at the same correlated color temperature). Besides, the transmitted and reflected light of each phosphor layer are revised by combining Kubelka-Munk and Mie-Lorenz theories. Through analysis, it is demonstrated that the packaging configuration of two-layer remote phosphor that employs red-emitting ${\alpha}-SrO{\cdot}3B_2O_3:Sm^{2+}$ phosphor particles provides a practical solution for general WLEDs lighting.