• Title/Summary/Keyword: Cluster theory

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A Study on the method for finding the degree of proficiency of technicians by the use of VTR and Machine of working character tests by a pattern of YK (VTR 및 YK식(式) 작업성격검사기(作業性格檢査器)를 이용(利用)한 기능공(技能工)의 숙련도측정(熟練度測定)에 관(關)한 연구(硏究))

  • Lee, Sun-Yo
    • Journal of Korean Institute of Industrial Engineers
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    • v.2 no.1
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    • pp.45-60
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    • 1976
  • In this study, Multiple Factor Analysis was undertaken for the purpose of substituting General Vocational Aptitude tester for paper tests according to the standardized and partially modified norm, and compared and analyzed these aptitude tests YK Type Working Character test for a test battery. In this analysis, four basis aptitude cluster of AQE was utilized as aptitude cluster, the study for skill was carried out by the method of sampling electronic aptitude cluster in four basis ones, and the parts needed in the process of its analysis were investigated by means of Video-Tape Recording. This paper was performed with sample test by application of the inverse variation curve from learning theory and induced learning rate as a measure of the degree of proficient of technicians, and from the obtained results illustrated optimum newly-production plan of ability program and load program by the use of computer program.

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A Kernel-Level Group Communication System for Highly Available Linux Cluster (리눅스 클러스터의 고가용성 보장을 위한 커널 수준 그룹 통신 시스템)

  • 이상균;박성용
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.10
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    • pp.533-543
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    • 2003
  • With the increase of interests in cluster, there have been a number of research efforts to address the high availability issues on cluster. However, there are no kernel-level group communication systems to support the development of kernel-level application programs and it is not easy to use traditional user-level group communication systems for the kernel-level applications. This paper presents the design and implementation issues of KCGCS(Kernel-level Cluster Group Communication System), which is a kernel-level group communication module for linux cluster. Unlike traditional user-level group communication systems, the KCGCS uses light-weight heartbeat messages and a ring-based heartbeat mechanism, which allows users to implement scalable failure detection mechanisms. Moreover, the KCGCS improves the reliability by using distributed coordinators to maintain membership information.

VIA-Based PC Cluster System for Efficient Information Retrieval (효율적인 정보 검색을 위한 VIA 기반 PC 클러스터 시스템)

  • Kang, Na-Young;Chung, Sang-Hwa;Jang, Han-Kook
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.10
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    • pp.539-549
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    • 2002
  • PC cluster-based Information Retrieval (IR) systems improve their performances by parallel processing of query terms using cluster nodes. However TCP/IP based communication used to exchange data between cluster nodes prevents the performance from being improved further. The user-level communication mechanisms solve the problem by eliminating the time-consuming kernel access in exchanging data between cluster nodes. The Virtual Interface Architecture (VIA) is one of the representative user-level communication mechanisms which provide low latency and high bandwidth. In this paper, we propose a VIA-based parallel IR system on a PC cluster. The IR system is implemented using the following three communication methods: Sealable Coherent Interface (SCI) based VIA, MPI on SCI based VIA, MPI on Fast Ethernet based VIA. Through experiments, the performances of the three methods are analyzed in various aspects.

Clusterförderung und -politik in Deutschland (독일의 지역산업 클러스터정책)

  • Ahn, Young-Jin
    • Journal of the Economic Geographical Society of Korea
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    • v.21 no.4
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    • pp.425-437
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    • 2018
  • Since the 1990s, clusters defined as a geographic concentration of interconnected companies, research and educational institutions, technology transfer agencies, and other public or semi-public institutions in a particular field have not only been subject to academic research, but have also become goals for various innovation and regional policies. Over the past 20 years Germany at both the Federal and $L{\ddot{a}}nder$ levels has been pursuing various cluster promotion policies and initiatives for upgrading industries' competitiveness and innovations, and some of these measures have been evaluated as successful. This study aims to examine the industrial cluster promotion policy of Germany. For this purpose, the study first outlines the concept of cluster and cluster policy theoretically, and then explores the formation and historical development of cluster polices of the German federal government.

Computational Study of the Molecular Structure, Vibrational Spectra and Energetics of the OIO Cation

  • Lee, Sang-Yeon
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1855-1858
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    • 2004
  • Molecular geometries for the cationic and neutral species of OXO (X=Cl, Br, and I) are optimized using the Hartree-Fock (HF) theory, the second order Moller-Plesset perturbation theory (MP2), the density functional theory with the B3LYP hybrid functional (B3LYP), and the coupled cluster theory using single and double excitation with a perturbational treatment of triplet excitation (CCSD[T]) methods, with two basis sets of triple zeta plus polarization quality. The single point calculations for these species are performed at the CCSD(T,Full) level. The harmonic vibrational frequencies for these species are calculated at the HF, MP2, B3LYP and CCSD(T) levels. The adiabatic ionization potential for OIO is calculated to be 936.7 kJ/mol at the CCSD(T,Full) level and the correct value is estimated to be around 945.4 kJ/mol.

Innovative Environment of Regional Industrial Clusters : Comparison of Daejon's Bio and Buchon's Mature Industries (지역산업군집의 혁신환경 : 대전 생물벤처산업과 부천 조립금속산업을 대상으로)

  • Nahm Kee-Bom
    • Journal of the Economic Geographical Society of Korea
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    • v.8 no.1
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    • pp.1-16
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    • 2005
  • Literature on cluster theory and cluster policy has been focused on the differences between mature industrial areas and innovative regions. Mature industrial areas are described as possessing little competence for innovation and lacking entrepreneurship to be transferred an innovative region, say, an innovative cluster. Old industrial regions are, however, rich in social capital, local networking, and regional institutionalization. This paper compares Buchon's mature industries with Daejon's bio-sector new start-ups in terms of innovative potential, socio-economic and cultural-economic mechanisms. Policy implications such as networking and business support systems on the differential types of industrial regions are offered.

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THE CONTRIBUTION TO THE EXTRAGALACTIC γ-RAY BACKGROUND BY HADRONIC INTERACTIONS OF COSMIC RAYS PRODUCING EUV EMISSION IN CLUSTERS OF GALAXIES

  • KUO PING-HUNG;BOWYER STUART;HWANG CHORNG- YUAN
    • Journal of The Korean Astronomical Society
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    • v.37 no.5
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    • pp.597-600
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    • 2004
  • A substantial number of processes have been suggested as possible contributors to the extragalactic $\gamma$-ray background (EGRB). Yet another contribution to this background will be emission produced in hadronic interactions of cosmic-ray protons with the cluster thermal gas; this class of cosmic rays (CRs) has been shown to be responsible for the EUV emission in the Coma Cluster of galaxies. In this paper we assume the CRs in the Coma Cluster is prototypic of all clusters and derive the contribution to the EGRB from all clusters over time. We examine two different possibilities for the scaling of the CR flux with cluster size: the number density of the CRs scale with the number density of the thermal plasma, and alternatively, the energy density of the CRs scale with the energy density of the plasma. We find that in all scenarios the EGRB produced by this process is sufficiently low that it will not be observable in comparison with other mechanisms that are likely to produce an EGRB.

Fuzzy Technique-based Identification of Close and Distant Clusters in Clustering

  • Lee, Kyung-Mi;Lee, Keon-Myung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.11 no.3
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    • pp.165-170
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    • 2011
  • Due to advances in hardware performance, user-friendly interfaces are becoming one of the major concerns in information systems. Linguistic conversation is a very natural way of human communications. Fuzzy techniques have been employed to liaison the discrepancy between the qualitative linguistic terms and quantitative computerized data. This paper deals with linguistic queries using clustering results on data sets, which are intended to retrieve the close clusters or distant clusters from the clustering results. In order to support such queries, a fuzzy technique-based method is proposed. The method introduces distance membership functions, namely, close and distant membership functions which transform the metric distance between two objects into the degree of closeness or farness, respectively. In order to measure the degree of closeness or farness between two clusters, both cluster closeness measure and cluster farness measure which incorporate distance membership function and cluster memberships are considered. For the flexibility of clustering, fuzzy clusters are assumed to be formed. This allows us to linguistically query close or distant clusters by constructing fuzzy relation based on the measures.

The lag analysis on the impact of patents on profitability of firms in software industry at segment level (특허가 기업의 수익성에 영향을 미치는 시차에 대한 미국 소프트웨어 세분시장 수준 분석)

  • Yi, Joon Hye;Jung, Won Kyo;Park, Sang Sung;Jang, Dong Sik
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.2
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    • pp.199-211
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    • 2012
  • There have been studies to evaluate valuation of firms by using patents in various ways. Also, the theory that value of patents helps enterprise's growth is valid in economics. However, when evaluating the value of the company, through the patent evaluation has not been used. Because of previous studies researched relation between patents and firms only at certain points. To solve this problem, this study intends to analyze lag between patent and profitability of the firms. In this study, we classified top 100 software firms in the United States through PBR, PER and value of intangible assets by using cluster analysis. And we applied Almon's distributed lag model to each cluster to find out lag between patent and profitability of the firms. As a result, in the cluster of more valuable companies, patents have an effect on profitability of the firms at regular lags. This study indicates that the patents are an important indicator to assess companies.

Environments of Galaxies and Their Effects on Galaxy Properties

  • Yoon, Yongmin;Im, Myungshin
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.38.2-38.2
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    • 2019
  • In the history of universe, galaxies are consistently affected by surrounding medium and neighbor galaxies. These effects control galaxy evolution, making properties of galaxies diverse and dependent on environments. We investigate environments of various types of galaxies and how they affect galaxy properties, such as bar structures and galaxy sizes, etc. First, we present the observational evidence that bars can form from a cluster-cluster interaction. The evidence indicates that bars can form due to a large-scale violent phenomenon, and cluster-cluster interaction should be considered as an important channel for bar formation. Second, we discover for the first time that local early-type galaxies heavier than 1011.2 Msol show a clear environmental dependence in mass-size relation, in such a way that galaxies are as much as 20 - 40% larger in densest environments than in underdense environments. This result suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory. Lastly, we investigate environments of the most massive galaxies and extremely massive quasars. By doing so, we find that massive galaxies are a much better signpost for galaxy clusters than massive quasars.

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