• Title/Summary/Keyword: Multi-dividing

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Parallel Generation of NC Tool Paths for Subdivision Surfaces

  • Dai Junfu;Wang Huawei;Qin Kaihuai
    • International Journal of CAD/CAM
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    • v.4 no.1
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    • pp.47-53
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    • 2004
  • The subdivision surface is the limit of recursively refined polyhedral mesh. It is quite intuitive that the multi-resolution feature can be utilized to simplify generation of NC (Numerical Control) tool paths for rough machining. In this paper, a new method of parallel NC tool path generation for subdivision surfaces is presented. The basic idea of the method includes two steps: first, extending G-Buffer to a strip buffer (called S-Buffer) by dividing the working area into strips to generate NC tool paths for objects of large size; second, generating NC tool paths by parallel implementation of S-Buffer based on MPI (Message Passing Interface). Moreover, the recursion depth of the surface can be estimated for a user-specified error tolerance, so we substitute the polyhedral mesh for the limit surface during rough machining. Furthermore, we exploit the locality of S-Buffer and develop a dynamic division and load-balanced strategy to effectively parallelize S-Buffer.

Progressive Image Coding using Wavelet Transform (웨이블릿 변환을 이용한 순차적 영상 부호화)

  • Kim, Yong-Yeon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.1
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    • pp.33-40
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    • 2014
  • In this paper we propose new image coding using wavelet transform. The new method constructs hierarchical bit plane and progressively transports each bit plane. The Proposed algorithm not only supports multi-resolution, dividing original image into special band and various resolution using Antonini's wavelet basis function but also reduces blocking effects that come into JPEG. In encoding time this algorithm considers each band characters and priority of transport order, and applies to fast search of image.

Cross-cultural Study on Knowledge Sharing in Open Collaboration: Collectivism vs. Individualism (문화에 따른 개방형 협업 지식공유 활동 비교 연구: 집단주의 문화와 개인주의 문화를 중심으로)

  • Baek, Hyunmi;Lee, Saerom
    • Knowledge Management Research
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    • v.19 no.2
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    • pp.133-150
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    • 2018
  • To cope with the rapid changes in the corporate environment, the creation of innovative output through various forms of collaboration have been discussed. For open collaborations, contributors who distribute to various countries and cultures are able to share knowledge via the internet without physical rewards or responsibilities. In this study, we focused on the open source software project, which is a representative open collaboration. We investigated the factors that affect the knowledge contribution of developers of various countries within the open collaboration platform. Specifically, we investigated the open collaborative nature of multi-culture developers by dividing cultures according to collectivism and individualism. We collected data on 26,604 developers using a python based web crawler for GitHub which is an open source software development platform, and conducted cross-cultural study. This paper contributes to the field of knowledge management by suggesting various impacts of antecedents such as hireability, and information exposure on knowledge sharing according to culture.

A Study on Piano String Vibration (피아노현의 진동에 관한 연구)

  • Kang, T.-H.;Yoon, Y.-K.;Lee, S.-J.
    • The Journal of the Acoustical Society of Korea
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    • v.8 no.1
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    • pp.13-22
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    • 1989
  • This study made an analysis of the characteristics of vibration & tone color of the piano strings on which a concentrated mass was set to give variety of different variations to the gamut. Theoretical analyses in this study were based on discrete and continuous system, of which the former was transformed into a multi-degree of freedom system by dividing into a number of small parts, while the latter utilized mode summation and Laplace transformation methods. And experiments were carried out with setting concentrated masses on upright piano string.

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Implementation and Performance Analysis of Web Robot for URL Analysis (URL 분석을 위한 웹 로봇 구현 및 성능분석)

  • Kim, Weon;Kim, Hie-Cheol;Chin, Yong-Ohk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3C
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    • pp.226-233
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    • 2002
  • This paper proposes the web robot based on Multi-Agent which the mutual dependency should be minimized each other with dividing the function each to collect Webpage. In result it is written to make a foundation for producing the effective statistics to analyze the domestic webpages and text, multimedia file composition ratio through performance analysis of the implemented system. It is easy that Web robot of the sequential processing method to collect Webpage on the same resource environment produces the limit of collecting performance. So to speak Webpages have "Dead-links" URL which is produced by the temporary host down and instability of network resource. If there are much "Dead-links" URL in the webpages, it takes a lot of time for web robot to collect HTML. The propose of this paper to be proposed, makes the maximum improvement to extract the webpages to process "Dead-links" URL on the Inactive URL scanner Agent.

Progressive Wavelet Transform Coding for Image Communication (영상통신을 위한 점진적 웨이브렛 변환 부호화)

  • 김정일;유재휘
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.3
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    • pp.89-98
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    • 1998
  • In this paper, we propose new image coding using wavelet transform. The new method constructs hierarchical bit plane and progressively transports each bit plane. The proposed algorithm not only supports multi-resolution, dividing original image into special band and various resolution but also reduces blocking effects that come into JPEG In encoding time, this algorithm considers each band characters and priority of transport order, and applies to fast search of image.

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Peak Power Control for Improvement of Stability in Multi-core System (멀티코어 시스템의 안정성 향상을 위한 피크파워 제어 알고리즘)

  • Park, Sung-Hwan;Kim, Jae-Hwan;Ahn, Byung-Gyu;Jung, Il-Jong;Lee, Seok-Hee;Chong, Jong-Wha
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.747-748
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    • 2008
  • In this paper, we propose a new algorithm for task scheduling consisting of subtask partitioning and subtask priority scheduling steps in order to keep the peak power under the system specification. The subtask partitioning stepis performed to minimize the idle operation time for processors by dividing a task into multiple subtasks using the least square method developed with power consumption pattern of tasks. In the subtask priority scheduling step, a priority is assigned to a subtask based on the power requirement and the power variation of subtask so that the peak power violation can be minimized and the task can be completed within the execution time deadline.

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Analysis of Reference Inquiries in the Field of Social Science in the Collaborative Reference Service Using the Co-Word Technique

  • Cho, Jane
    • Journal of the Korean Society for Library and Information Science
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    • v.49 no.1
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    • pp.129-148
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    • 2015
  • This study grasped the true nature of the inquiry domain by analysing the requests for collaborative reference service in the social science field using the co-word technique, and schematized the intellectual structure. First, this study extracted 748 uncontrolled keywords from inquiries for reference in the field of social science. Second, calculated similarity indices between the words on the basis of co-occurrence frequency, and performed not only clustering but also MDS mapping. Third, to grasp the difference in inquiries for reference by period, dividing the period into two parts, and performed comparative analysis. As a result, there formed 5 clusters and "Korea Education" showed an overwhelming size with 40.3% among those clusters. The result of the analysis through the period division showed there were many questions about "Education" during the first half, while a lot of inquiries with focus on "welfare and business information" during the second half.

Backward Quadtree Disparity Estimation for Efficient Multi-view Image Coder (효율적인 다시점 영상 부호화기를 위한 역방향 사진트리 변이 추정)

  • 최승철;김용태;손광훈
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1911-1914
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    • 2003
  • This paper proposes efficient system for multiview images using backward quadtree disparity estimation. Previous quadtree method usually divides current image. In this work, backward quadtree divides reference image. So, it does not need to code quadtree data. For backward quadtree, quadtree information map is generated. By using this map, adaptive dividing is possible. And, conventional bi-directional matching method is used with backward quadtree. These methods increase subject and object quality of decoded test images. For multiview images, panorama synthesizing method was used. Panorama image and right-most image are used for reference image for intermediate view images coding.

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Finite element modeling and dynamic characteristic analysis of the tilting turret slide system (틸팅터릿 이송시스템의 유한요소 모델링 및 동특성 해석)

  • 정상화;김상석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.10a
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    • pp.188-192
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    • 2000
  • In multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of each structures such as saddle, careg, and turret are simulated by MSC/NASTRAN, for the purpose of developing the effective design. The results of mode analysis and frequency analysis are visualized with PATRAN, and the mothod which can solve the resornance problem by eigenvalues and eigenvectors of each axe is developed as well.

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