• Title/Summary/Keyword: Tiling

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Automatic Generation of Tetrahedral Meshes from General Sections (일반 단면으로부터 사면체 요소망의 자동생성)

  • Chae, Su-Won;Lee, Gyu-Min;Sin, Sang-Yeop
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.1 s.173
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    • pp.196-205
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    • 2000
  • Computed Tomography (CT), Nuclear Magnetic Resonance Imaging (MR1) and some ultrasound techniques make it possible to obtain cross sections of human body or mechanical parts. In CAD system, a series of sectional surfaces can also be obtained from solid models of 3D objects. In this paper we introduce a tetrahedral meshing algorithm from these series of general sections using basic operators. In this scheme. general sections of three-dimensional object are triangulated first and side surfaces between two sections are triangulated by the use of tiling process. Finally tetrahedral meshing process is performed on each layer of 3D objects, which is composed of two general sections and one side surface.

High-Performance Computer-Generated Hologram by Optimized Implementation of Parallel GPGPUs

  • Lee, Yoon-Hyuk;Seo, Young-Ho;Yoo, Ji-Sang;Kim, Dong-Wook
    • Journal of the Optical Society of Korea
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    • v.18 no.6
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    • pp.698-705
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    • 2014
  • We propose a new development for calculating a computer-generated hologram (CGH) through the use of multiple general-purpose graphics processing units (GPGPUs). For optimization of the implementation, CGH parallelization, object point tiling, memory selection for object point, hologram tiling, CGMA (compute to global memory access) ratio by block size, and memory mapping were considered. The proposed CGH was equipped with a digital holographic video system consisting of a camera system for capturing images (object points) and CPU/GPGPU software (S/W) for various image processing activities. The proposed system can generate about 37 full HD holograms per second using about 6K object points.

The Study on the Kinematics of Carbody Tilting Mechanism for Railway Vehicles (철도차량용 차체틸팅기구의 기구학적 특성연구)

  • 김정석;김남포;고태환
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.384-388
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    • 2004
  • This study presents parametric studies for design of tiling mechanism to be used in 180km/h tilting train. The titling mechanism is composed of 4 links, a tilting bolster and an electro-mechanical actuator. First we have determined the installation height of tilting actuator using 3D tilting bogie modeling. Secondary, we verified movements of the tiling center and train body CG along variation of upper and lower span length. From this study, we obtained the upper and lower span length to minimize the lateral and vertical motion of CG of train body. Finally, we evaluated the tilting actuator force and power required to tilt the train body to $\pm$8$^{\circ}$.

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Image Fingerprinting Scheme for Print-and-capture Attacking Model (Print-and-capture 공격 모델을 위한 이미지 핑거프링팅 기법)

  • Lee, Seon-Hwa;Kim, Won-Gyum;Seo, Yong-Seok
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.427-428
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    • 2006
  • This paper presents an image fingerprinting scheme for the print-to-capture model performed by a photo printer and digital camera. When capturing an image by a digital camera, various kinds of distortions such as noise, geometrical distortions, and lens distortions are applied. slightly and simultaneously. In this paper, we consider several steps to extract fingerprints from the distorted image in print-and capture scenario. To embed ID into an image as a fingerprint, multi-bits embedding is applied. We embed 64 bits information as a fingerprint into spatial domain of color images. In order to restore a captured image from distortions a noise reduction filter is performed and a rectilinear tiling pattern is used as a template. To make the template, a multi-bits fingerprint is embedded repeatedly like a tiling pattern. We show that the extracting is successful from the image captured by a digital camera through the experiment.

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The illumination system design of Integrated Screen 3D Display

  • Lin, Chu-Hsun;Lin, Chun-Chuan;Lo, Hsin-Hsiang;Chung, Shuang-Chao;Chen, Tian-Yuan;Wang, Chy-Lin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1379-1382
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    • 2009
  • The 3D display has been used in optical projection technology to connect twenty mini- projectors with seamless image tiling. In this way, we can improve the projected resolution by reducing each project screen and increase projected area by connect several mini-projectors. In this article, the illumination system uses the LED light source, non- telecentric structure and LCOS panel, and it's total length is less than 10 centimeter. It can build a seamless large display by tiling multiple projectors.

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Implementation of Tile Searching and Indexing Management Algorithms for Mobile GIS Performance Enhancement

  • Lee, Kang-Won;Choi, Jin-Young
    • Journal of Internet of Things and Convergence
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    • v.1 no.1
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    • pp.11-19
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    • 2015
  • The mobile and ubiquitous environment is experiencing a rapid development of information and communications technology as it provides an ever increasing flow of information. Particularly, GIS is now widely applied in daily life due to its high accuracy and functionality. GIS information is utilized through the tiling method, which divides and manages large-scale map information. The tiling method manages map information and additional information to allow overlay, so as to facilitate quick access to tiled data. Unlike past studies, this paper proposes a new architecture and algorithms for tile searching and indexing management to optimize map information and additional information for GIS mobile applications. Since this involves the processing of large-scale information and continuous information changes, information is clustered for rapid processing. In addition, data size is minimized to overcome the constrained performance associated with mobile devices. Our system has been implemented in actual services, leading to a twofold increase in performance in terms of processing speed and mobile bandwidth.

Photomosaic Algorithm with Adaptive Tilting and Block Matching (적응적 타일링 및 블록 매칭을 통한 포토 모자이크 알고리즘)

  • Seo, Sung-Jin;Kim, Ki-Wong;Kim, Sun-Myeng;Lee, Hae-Yeoun
    • The KIPS Transactions:PartB
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    • v.19B no.1
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    • pp.1-8
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    • 2012
  • Mosaic is to make a big image by gathering lots of small materials having various colors. With advance of digital imaging techniques, photomosaic techniques using photos are widely used. In this paper, we presents an automatic photomosaic algorithm based on adaptive tiling and block matching. The proposed algorithm is composed of two processes: photo database generation and photomosaic generation. Photo database is a set of photos (or tiles) used for mosaic, where a tile is divided into $4{\times}4$ regions and the average RGB value of each region is the feature of the tile. Photomosaic generation is composed of 4 steps: feature extraction, adaptive tiling, block matching, and intensity adjustment. In feature extraction, the feature of each block is calculated after the image is splitted into the preset size of blocks. In adaptive tiling, the blocks having similar similarities are merged. Then, the blocks are compared with tiles in photo database by comparing euclidean distance as a similarity measure in block matching. Finally, in intensity adjustment, the intensity of the matched tile is replaced as that of the block to increase the similarity between the tile and the block. Also, a tile redundancy minimization scheme of adjacent blocks is applied to enhance the quality of mosaic photos. In comparison with Andrea mosaic software, the proposed algorithm outperforms in quantitative and qualitative analysis.

DESIGN AND IMPLEMENTATION OF 3D TERRAIN RENDERING SYSTEM ON MOBILE ENVIRONMENT USING HIGH RESOLUTION SATELLITE IMAGERY

  • Kim, Seung-Yub;Lee, Ki-Won
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.417-420
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    • 2006
  • In these days, mobile application dealing with information contents on mobile or handheld devices such as mobile communicator, PDA or WAP device face the most important industrial needs. The motivation of this study is the design and implementation of mobile application using high resolution satellite imagery, large-sized image data set. Although major advantages of mobile devices are portability and mobility to users, limited system resources such as small-sized memory, slow CPU, low power and small screen size are the main obstacles to developers who should handle a large volume of geo-based 3D model. Related to this, the previous works have been concentrated on GIS-based location awareness services on mobile; however, the mobile 3D terrain model, which aims at this study, with the source data of DEM (Digital Elevation Model) and high resolution satellite imagery is not considered yet, in the other mobile systems. The main functions of 3D graphic processing or pixel pipeline in this prototype are implemented with OpenGL|ES (Embedded System) standard API (Application Programming Interface) released by Khronos group. In the developing stage, experiments to investigate optimal operation environment and good performance are carried out: TIN-based vertex generation with regular elevation data, image tiling, and image-vertex texturing, text processing of Unicode type and ASCII type.

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Plagiarism Detection among Source Codes using Adaptive Methods

  • Lee, Yun-Jung;Lim, Jin-Su;Ji, Jeong-Hoon;Cho, Hwaun-Gue;Woo, Gyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.6
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    • pp.1627-1648
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    • 2012
  • We propose an adaptive method for detecting plagiarized pairs from a large set of source code. This method is adaptive in that it uses an adaptive algorithm and it provides an adaptive threshold for determining plagiarism. Conventional algorithms are based on greedy string tiling or on local alignments of two code strings. However, most of them are not adaptive; they do not consider the characteristics of the program set, thereby causing a problem for a program set in which all the programs are inherently similar. We propose adaptive local alignment-a variant of local alignment that uses an adaptive similarity matrix. Each entry of this matrix is the logarithm of the probabilities of the keywords based on their frequency in a given program set. We also propose an adaptive threshold based on the local outlier factor (LOF), which represents the likelihood of an entity being an outlier. Experimental results indicate that our method is more sensitive than JPlag, which uses greedy string tiling for detecting plagiarism-suspected code pairs. Further, the adaptive threshold based on the LOF is shown to be effective, and the detection performance shows high sensitivity with negligible loss of specificity, compared with that using a fixed threshold.