• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1673-1681
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• 2018

In this paper, the fabrication of a white light-emitting diode (WLED) package capable of producing different color rendering indexes (CRI ($R_a$)) using different types of phosphors (YAG:Ce, Silicate, Nitride, LuAG) for the LEDs is presented. The color quality is evaluated based on the current and temperature variation conditions. The evaluation method for color quality compares the existing CIE 13.3 method and the new IES TM-30-15 method. The CRI ($R_a$) defined in the conventional CIE 13.3 has the disadvantage. This cannot offer any information relevant to the user's preference. However, the newly proposed IES TM-30-15 method suggests the additional measure related to user's preference such as Color Gamut ($R_g$). The present experimental results obtained using the IES TM-30-15 show that the color quality of the WLEDs using green and red phosphors are better than that of the WLEDs using yellow phosphor, but their luminous efficacies are lower. The color quality of WLEDs using green and red phosphors are more stable than that of the WLEDs using yellow phosphor, for current and temperature variations, and it is verified that the phosphor causes this change. The evaluation method for color quality, based on IES TM-30-15, is proved to be capable of overcoming the problems of the existing evaluation methods by this study.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.715-719
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• 1998

In this paper, we propose a color enhancement system which is based on the improvement of transition time problem and specific color detection stability. The proposcd system apply the time difference correction step to corrects time difference which is taken place at the transimission process between color signal and color subcarrier signal and to reduce detection errors. And also, we proposed stability method to improve transition time problem and detection efficiency as the control of reference color. The proposed system controls specific color when the mean difference value of detected voltages greater than the value of minimum discriminate voltages of two adjacent color signals. Thus, the color enhancement system improves detection efficiency and controls specific color from the color signal without overlapping of correction range.

• Journal of KIISE:Software and Applications
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• v.32 no.3
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• pp.141-152
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• 2005

A new emotion-based image retrieval method is proposed in this paper. Query emotion descriptors called query color code and query gray code are designed based on the human evaluation on 13 emotions('like', 'beautiful', 'natural', 'dynamic', 'warm', 'gay', 'cheerful', 'unstable', 'light' 'strong', 'gaudy' 'hard', 'heavy') when 30 random patterns with different color, intensity, and dot sizes are presented. For emotion image retrieval, once a query emotion is selected, associated query color code and query gray code are selected. Next, DB color code and DB gray code that capture color and, intensify and dot size are extracted in each database image and a matching process between two color codes and between two gray codes are peformed to retrieve relevant emotion images. Also, a new relevance feedback method is proposed. The method incorporates human intention in the retrieval process by dynamically updating weights of the query and DB color codes and weights of an intra query color code. For the experiments over 450 images, the number of positive images was higher than that of negative images at the initial query and increased according to the relevance feedback.

• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.2
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• pp.1-20
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• 1996

we describes a method for realizing the color conversion from the tristimulus (X, Y, Z) values to the print ink signals (C, M, Y) by using neural networks. The realized nonlinear color conversion system consists of two hidden layers those have seventeen nodes. We determined the C, M, Y values of the input control signals to compensate the printer nonlinearity of real systems. Experimental results showed that the described method is useful and valid to realized the nonlinear color conversion.

• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.2
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• pp.65-80
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• 1996

Ink trap is one of the important factors to determine the color in multi-color overprints. This study was carried out for the purpose for analyzing the relationships between ink traps and color differences in two-color solid overprints. The specimens were printed under four different conditions that the overprinting ink sequence of M(Magenta) or C(Cyan) and the overprinting method of W(Wet-on-Wet) or D(Wet-on-Dry) were changed altermately, that is M+C-W or C+M-W and M+C-D or C+M-D.

• Journal of Korea Multimedia Society
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• v.21 no.11
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• pp.1279-1287
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• 2018

In this paper, a new type of color coordinate conversion is proposed as modified CIEXYZ from RGB to compress the color gamut. The proposed segmentation includes principal component analysis for the optimal projection of a feature vector into a one-dimensional feature. The final step adopted for lip segmentation is Otsu's threshold for a two-class problem. The performance of the proposed method was better than that of conventional methods, especially for the chromatic feature.

• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.305-315
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• 2012

Color correction between two or multiple images is very crucial for the development of subsequent algorithms and stereoscopic 3D camera system. Even though various color correction methods are proposed recently, there are few methods for measuring the performance of these methods. In addition, when two images have view variation by camera positions, previous methods for the performance measurement may not be appropriate. In this paper, we propose a method of measuring color difference between corresponding images for color correction. This method finds matching points that have the same colors between two scenes to consider the view variation by correspondence searches. Then, we calculate statistics from neighbor regions of these matching points to measure color difference. From this approach, we can consider misalignment of corresponding points contrary to conventional geometric transformation by a single homography. To handle the case that matching points cannot cover the whole regions, we calculate statistics of color difference from the whole image regions. Finally, the color difference is computed by the weighted summation between correspondence based and the whole region based approaches. This weight is determined by calculating the ratio of occupying regions by correspondence based color comparison.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1659-1664
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• 2013

The objectives of this study were to investigate color patterns of shell and mantle edge pigmentation of a Pacific oyster, C. gigas, and to estimate variance components of the two colors. A sample of 240 F0 oysters was collected from six aquaculture farms in Tongyeong, Korea to measure shell color and mantle edge pigmentation. Among the F0s, male and female individuals with black (white) shell and black (white) mantle edge were selected and mated to generate three F1 full-sib black (white) cross families (N = 265). Two and four F2 cross families (N = 286) were also produced from black and white F1 selected individuals, respectively. Variance component estimates due to residuals and families within color were obtained using SAS PROC VARCOMP procedures to estimate heritability of shell and mantle edge pigmentation. In the F0 generation, about 29% (11%) had black (white) color for both shell and mantle edge. However, in the F1 and F2 black (white) cross families, 75% (67%) and 100% (100%) of oysters had black (white) shell colors, and 59% (23%) and 79% (55%) had black (white) mantle edge, respectively. Spearman correlation coefficients between shell and mantle edge color were 0.25, 0.74, and 0.92 in F0, F1, and F2 generations, respectively, indicating that, with generations of selection process, an individual with black (white) shell color is more likely to have black (white) mantle edge pigmentation. This suggests that shell color could be a good indicator trait for mantle edge pigmentation if selection of both the colors is implemented for a couple of generations. Estimates of heritability were 0.41 and 0.77 for shell color and 0.27 and 0.08 for mantle edge pigmentation in the F1 and F2 generations, respectively, indicating that, in general, significant proportions of phenotypic variations for the shell and mantle edge colors are explained by genetic variations between individuals. These results suggest that the two color traits are inheritable and correlated, enabling effective selection on shell and mantle edge color.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.933-938
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• 2001

A 5-valve(intake 3-valve) engine has been developed to increase engine performance. These vehicles have a high power caused by the decrease of inertia mass of an intake valve and the increase of intake effective area. In this study, velocity profiles at near intake valves were inspected by using a two-color PIV and laser sheet method with tumble control valve(TCV). In addition, steady flow tests were performed to quantify tumble ratio on flow-fields generated with a TCV. These experimental results show that the tendency of the tunble ratio in intake 3-valve engine is different from the one in intake 2-valve engine. From this results, the intake flow characteristics around intake valves were made clear.

• Journal of The Korean Astronomical Society
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• v.42 no.4
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• pp.81-91
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• 2009

We make a new catalog of AGB stars in our Galaxy from the sources listed in the Infrared Astronomical Satellite (IRAS) point source catalog (PSC) compiling the lists of previous works with verifying processes. We verify the class identification of AGB stars into oxygen-rich and carbon-rich stars using the information from recent investigations. For the large sample of AGB stars, we present infrared two-color diagrams from the observations at near infrared bands and IRAS PSC. On the two-color diagrams, we plot the tracks of theoretical radiative transfer model results with increasing dust shell optical depths. Comparing the observations with the theoretical tracks, we discuss the meaning of the infrared two-color diagrams.