• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.1-6
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• 2000

In this paper, organic dispersion type back light EL(Electroluminescent) devices were manufactured using Ethyl hydroxy ethyl cellulose as organic binder, ZnS:Cu as phosphor powder and $BaTiO_3$ as dielectrics by screen printing method, which are focused on as a new light source. The properties of the fabricated organic dispersion type back light EL devices were showed $1.98[mA/\m^2]$ of current density, 0.075[W] of power consumption, 7.1[nF] of capacitance at $25[^{\circ}C]$, 100[V], 400[Hz], respectively. Also brightness of the fabricated device was revealed $20~110[cd/\m^2]$ at 50~150[V] and the change of color was shoed bluish green of x=0.1711, y=0.3676 which are color coordinate by CIE.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.666-671
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• 2016

This paper introduces a device providing close local lighting to the affected part, where the operation-purpose astral lamp alone cannot shed light directly, in an operation room of hospitals or clinics, which helps clinical doctors perform safe treatment of the affected part deep inside a human body. This medical assisting lighting is a device necessary to prevent fatal operation failures, which can occur with minute operation processes, such as tumor removal or angiorrhaphy. The components, such as the light source and power supply were designed to be low power consuming and small in size, have a narrow angle lens was used to increase the light spreading effect and focused illumination. The end-caps of the light transmission device using an optical cable and the lighting device were designed in the waterproof type to enable disinfection of these devices after use for the next patients. According to the measurement of the light source properties made after development of the retractor lighting device, the illumination intensity was 490 lux, the brightness was $11,550cd/m^2$, general color rendering index was 78, color temperature was 11,000K, and the intensity distribution was even, which were confirmed to be adequate for medical assisting local lighting.

• Animal Bioscience
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• v.36 no.5
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• pp.731-739
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• 2023

Objective: This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. Methods: A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. Results: The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L^*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Conclusion: Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.727-731
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• 2005

We introduce a method of color-coded illumination that is simple and fast. The purpose of this study is the real-time shape measurement of three-dimensional object by using color-coded information. The object is illuminated by a prism color spectrum. A color spectrum of a white-light source is imaged onto the object by illumination from one certain direction. The object is observed by a color CCD camera from a direction of observation, which is different from the direction of illumination. It can be evaluated by the red, blue, green using a inherence colors of hue value are good point.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.248-254
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• 2009

The aim of this study is to optimize the light source combination which can maximize the capability of the illuminance and color temperature of circadian lighting apparatus. To achieve this goal, the circadian lighting apparatus was consisted of two different types of fluorescent lamps having different color temperature of 2000K and 8000K, respectively, and the capability of the illuminance and color temperature of circadian lighting apparatus was evaluated by optical simulation as the number of the respective lamps were varied. Considering the Kruithof's curve and exceptional cases, the ranges of illuminance and color temperature for the living activities were reclassified in 4 groups - gathering, studying, relaxing and sleeping - so that the target range of illuminance and color temperature of lighting apparatus was settled. As a result, in the case of adopting two fixtures in which four 2000K lamps and five 8000K lamps were consisted, respectively to one fixture, the highest illuminance was expected at 4000K and over 500lx of illuminance was calculated between 3000K and 6000K. Through the optimized combination of light sources, the range of illuminance and color temperature were calculated as $44{\sim}750lx$ and $2500{\sim}6500K$, respectively.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.39-46
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• 2001

In this paper we propose a new method that can be estimation the spectral power distribution of the light source from three-band images. the light source is estimated by dividing the reflected spectral power distribution of the maximum achromatic region(L(λ)) by the corresponding surface reflectance(Ο(λ)). In order to obtain reflected spectral power distribution of the maximum achromatic region from three-bend images, a modified gray world assumption algorithm is adapted. And the maximum surface reflectance is estimated using the principal component analysis method along with achromatic population. The achromatic population is created from a set of given Munsell color chips whose chroma vector is less than threshold. Cumulative contribution ratio of principal components from the first to the third for classified achromatic population was about 99.75%. The reconstruction of illumination spectral power distribution by using achromatic population and three-band digital images captured under various light source was examined, and evaluated by RMSE between the original and reconstructed illumination spectral power distribution. This work was supported by grant No (2000-1-30200-005-3) from the Basic Research Program of the Korea Science & Engineering Foundation.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.299-304
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• 2012

Purpose: The aim of this study is to investigate the effect of different experience level and different light source on shade selection ability comparing prosthodontist group and dental student group under 4,000 K and 5,500 K light. Materials and methods: After color difference of Vitapan 3D-master shade guides was measured, 3 sets of 5 shade tabs were selected with similar value but have different chroma (set a, b, c). Also 3 sets of 5 shade tabs were selected with similar chroma but have different values (set d, e, f). Under 4,000 K and 5,500 K light sources, ten prosthodontists and ten dental students were allowed to match in one set of 5 tabs the same shade tab with the tab which was originally selected in the other set of 5 tabs. Color differences of original tab and matched tab were measured by spectrophotometer and the shade selection ability was evaluated with those data. Evaluation of color difference value was performed in regard to different light conditions and different level of experience, followed by t-test with 95% confidence interval. Results: Color difference values under 4,000 K and 5,500 K light source were $1.62{\pm}2.0$, and $1.33{\pm}1.7$ respectively. In addition, color difference values of prosthodontist group and dental student group were $1.34{\pm}1.7$, and $1.61{\pm}2.0$ respectively. Difference of shade selection ability was not found under either different light sources (P=.398), or different experience level (P=.221). Conclusion: Level of experience did not affect on the shade selection ability when prosthodontists and dental students matched the shades with the same shade tab under the same light source.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.1
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• pp.67-72
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• 2013

Cloud detection and analysis from satellite images has been a topic of research in many atmospheric and environmental studies; however, it still is a challenging task for many reasons. In this paper, we propose a new method for cloud-type classification using fuzzy logic. Knowing that visible-light images of clouds contain thickness related information, while infrared images haves height-related information, we propose a two-layered fuzzy logic based on the input source to provide us with a relatively clear-cut threshold in classification. Traditional noise-removal methods that use reflection/release characteristics of infrared images often produce false positive cloud areas, such as fog thereby it negatively affecting the classification accuracy. In this study, we used the color information from source images to extract the region of interest while avoiding false positives. The structure of fuzzy inference was also changed, because we utilized three types of source images: visible-light, infrared, and near-infrared images. When a cloud appears in both the visible-light image and the infrared image, the fuzzy membership function has a different form. Therefore we designed two sets of fuzzy inference rules and related classification rules. In our experiment, the proposed method was verified to be efficient and more accurate than the previous fuzzy logic attempt that used infrared image features.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.218.2-218.2
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• 2012

In the remote sensing researches, the reflected bright source such as snow, cloud have effects on the image quality of wanted signal. Even though those signal from bright source are adjusted in corresponding pixel level with atmospheric correction algorithm or radiometric correction, those can be problem to the nearby signal as one of the stray light source. Especially, in the step and stare observational method which makes one mosaic image with several snap shots, one of target area can affect next to the other snap shot each other. Presented in this paper focused on the stray light analysis from unwanted reflected bright source for geostationary ocean color sensor. The stray light effect for total 16 slot images each other were performed according to 8 band filters. For the realistic simulation, we constructed system modeling with integrated ray tracing technique which realizes the same space time in the remote sensing observation among the Sun, the Earth, and the satellite. Computed stray light effect in the results of paper demonstrates the distinguishable radiance value at the specific time and space.

• Korean Journal of Optics and Photonics
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• v.8 no.3
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• pp.183-188
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• 1997

Cut-off filters would reject all the radiation below and transmit all that above a certain wavelength or vice versa. In this paper, we study design and farbrication of dichroic mirror and broadband high reflective mirror for color separation of white laser beam source to R.G.B color beam source. In laser display system, color separation is very important. We fabricated below specific component for finite color separation of the Kr-Ar laser source. At 45$^{\circ}$ incidence s-polarized light , it is required that - H/R in blue region R>99%, H/T in green and red region T>90% - H/R in green and red region R>99%, H/T in blue region T>90% - H/R in green region R>99%, H/T in red region T>90% We composed the optical system and realize the full color image.