• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.20-27
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• 2006

Multi-level thresholding is a method that is widely used in image segmentation. However most of the existing methods are not suited to be directly used in applicable fields and moreover expanded until a step of image segmentation. This paper proposes region-based multi-level thresholding as an image segmentation method. At first we classify pixels of each color channel to two clusters by using EWFCM(Entropy-based Weighted Fuzzy C-Means) algorithm that is an improved FCM algorithm with spatial information between pixels. To obtain better segmentation results, a reduction of clusters is then performed by a region-based reclassification step based on a similarity between regions existing in a cluster and the other clusters. The clusters are created using the classification information of pixels according to color channel. We finally perform a region merging by Bayesian algorithm based on Kullback-Leibler distance between a region and the neighboring regions as a post-processing method as many regions still exist in image. Experiments show that region-based multi-level thresholding is superior to cluster-, pixel-based multi-level thresholding, and the existing mettled. And much better segmentation results are obtained by the post-processing method.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.93-102
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• 1996

The optical system of lens must be designed to tramsmit light over wide wavelength range and to have lower reflectivity in order to obtain higher spectral transmittance. However, the reflection color light appears due to the remain-reflection light in any optical system of lens. The wavelength of the reflection color light can be controlled by the structure of the number of layers, thickness of layer, reflective index, wavelength of incidence, and substrate etc. In the optical systems of the single layer and the double layers, the reflection color light appears in the condition of the anti-reflection of ${\lambda}s/{\lambda}$ = 1.0 by the color mixture of the remain-reflection lights in the ranges of the longer wavelength side and the shorter one of the ${\lambda}s/{\lambda}$ = 1.0, and of the double layers and triple layers, the reflection color light positioned at P1 < ${\lambda}s/{\lambda}$ < P2 appears in the condition of the antireflection of ${\lambda}s/{\lambda}$ = $PI{\ll}1$ and $P2{\gg}1$. In the optical system of the multi-layers, many antireflection points are existed at the various s/ values, and the reflection color light by the color mixture of the remain-reflection lights in the ranges except for the antireflection points.

• Journal of Fashion Business
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• v.20 no.2
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• pp.107-123
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• 2016

The purpose of this study is to obtain specific data about the characteristics of color preference on Women's street fashion within China and Korea. Photos of Women's street fashion from the twenties and thirties were taken in person in four cities in China(Beijing, Dalian, Qingdao and Nanjing) and Seoul from July 2nd to August 10th, 2015. Three hundred photos in each city were selected, making a total of 1,500 photos. In the analysis of the colors of the clothing in these five cities, the uses of the multi color was most frequent in Dalian, while those of Black was most prevalent in Beijing, Qingdao, Nanjing and Seoul. The Black proved to be commonly preferred through all the items, regardless of terms of the nationality, areas and seasonal changes. The high incidence of Purple Blue color in Beijing, Dalian and Qingdao might be attributed to their preference of the blue jeans. The Multi color was highly shown in all the cities which might be due to their preference of compound colors rather than the mono ones. The high preference for the chromatic colors such as Red, Yellow Red and Yellow might be ascribed to the Chinese traditional color preferences. The differences lies in the color tones, such as the dark and light grayish tone emphasized in Seoul and Nanjing, and vivid and strong tones in Beijing, Dalian and Qingdao. Seoul shows a liking for the achromatic colors, preferring dark and grayish tones, compared with four cities in China, only Nanjing has a similar trend to Seoul. This study analyzes geographical preferences in China that possibly contribute to the launching of Korean fashion brands in view of the design and marketing as a useful basic resources.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.3
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• pp.197-207
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• 2024

This study aims to evaluate the color stability and surface roughness of the single-shade composite resin after finishing and polishing for primary molars. A single-shade composite resin (OM, OMNICHROMA) and two multi-shade composite resins (FT, Filtek^TM Z350XT; ES, ESTELITE^® SIGMA QUICK) were included. The specimens were divided into three subgroups using different polishing methods: control, Sof-Lex XT, and Sof-Lex Diamond. For color stability tests, cavities were prepared on extracted primary second molars and restored with experimental composite resins. Each specimen was immersed in the coffee solution for 48 hours. The color difference of each specimen was calculated. For surface roughness tests, cylindrical specimens were crafted with experimental composite resins. Surface roughness was analyzed using an atomic force microscope and a scanning electron microscope. In the color stability tests, FT demonstrated a significantly lower ΔE_ab than ES among the control groups, but no significant differences were observed between the ΔE_ab values of OM and FT or OM and ES. Additionally, no significant differences were found between the Sof-Lex XT and Sof-Lex Diamond subgroups in the three composite groups. Moreover, no significant differences in the surface roughness were found between the three composite groups, regardless of the polishing methods. The single-shade composite resin demonstrated comparable color stability and surface roughness to that of the multi-shade composite resins regardless of the polishing methods used in restoring primary molars. The single-shade composite resin is expected to be applicable in clinical pediatric dentistry reducing chair time due to the easy shade matching procedures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.53-59
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• 2009

Multi-view video is necessary to develop a new compression encoding technique for storage and transmission, because of a huge amount of data. Layered depth image is an efficient representation method of multi-view video data. This method makes a data structure that is synthesis of multi-view color and depth image. This paper proposed enhanced compression method by presentation of efficient layered depth image using real distance comparison, solution of overlap problem, and interpolation. In experimental results, confirmed high compression performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.321-324
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• 2010

There have been lots of researches on a multi-core processor. The enhancement has been performed through parallelization method. Multi-core architecture in the mobile environment has emerged. But, there is a limit to a mobile CPU's performance. GP-GPU(General-Purpose computing on Graphics Processing Units) can improve performance without adding other dedicated hardware. This paper presents the implementation of Inverse Quantization, Inverse DCT and Color Space Conversion module in H.264/AVC decoder using Multi-Core GP-GPU for a mobile environments. The proposed architecture improves approximately 50% of performance when it use all the features.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.38-44
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• 2021

To cater to the transition from single-color to multicolor/multi-material printing, this paper proposes a cartridge-replacing type multi-nozzle Fused Depositon Modeling(FDM) three-dimensional (3D) printer. In the test printing run, tool change failure/wobble/layer shift occurred. It was confirmed that improper support was the cause of this tool change failure. As a solution, spline and electromagnetic cartridges were designed. Wobble was caused by machine vibration and the motor stepping out. To minimize wobble, an additional Z-axis was installed, and the four-point bed leveling method was used instead of the three-point bed leveling method. The occurrence of layer shift was ascribed to the eccentricity of the Z-axis lead screw. Therefore, slit coupler was replaced with an Oldham type. In addition to the mechanical supplementation, the control environment was integrated to prevent accidents and signal errors due to wire connections. Before the final test printing run, a rectifier circuit was added to the motor to secure precise control stability. The final test printing run confirmed that the wobble/layer shift phenomenon was minimized, and the maximum error between layers was reduced to 0.05.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.166-173
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• 2020

Multi-view images, which are widely used for providing free-viewpoint services, can enhance the quality of synthetic views when the number of views increases. However, there needs an efficient representation method because of the tremendous amount of data. In this paper, we propose a method for generating point cloud data for the efficient representation of multi-view color and depth images. The proposed method conducts sequential reconstruction of point clouds at each viewpoint as a method of deleting duplicate data. A 3D point of a point cloud is projected to a frame to be reconstructed, and the color and depth of the 3D point is compared with the pixel where it is projected. When the 3D point and the pixel are similar enough, then the pixel is not used for generating a 3D point. In this way, we can reduce the number of reconstructed 3D points. Experimental results show that the propose method generates a point cloud which can generate multi-view images while minimizing the number of 3D points.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.1
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• pp.46-51
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• 2005

Intelligent Space(ISpace) is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment, it is very important that the system knows the location information to offer the useful services. In order to achieve these goals, we present a method for representing, tracking and human following by fusing distributed multiple vision systems in ISpace, with application to pedestrian tracking in a crowd. And the article presents the integration of color distributions into particle filtering. Particle filters provide a robust tracking framework under ambiguity conditions. We propose to track the moving objects by generating hypotheses not in the image plan but on the top-view reconstruction of the scene. Comparative results on real video sequences show the advantage of our method for multi-object tracking. Simulations are carried out to evaluate the proposed performance. Also, the method is applied to the intelligent environment and its performance is verified by the experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1046-1049
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• 2006

We proposed a simplified fabrication structure and method which can provide separate Red (R), Green (G), Blue (B), and White (W) OLED pixels with 2 metal-mask changes in emitting layer fabrication inspired from the structure of multi-layer white OLED and carrier blocking mechanism. A red emission layer for the R and W pixel with 1st mask, and then a blue emission layer with hole blocking layer for the B and W pixel with 2nd mask, and finally a common green emission layer were deposited sequentially. We expect that this concept would be very useful to the actual fabrication of multi-color OLED display although additional optimization is needed.