• Title/Summary/Keyword: Cluster system

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The Strategies for Forming Governance System to Raise Industrial Competitiveness of Metal and Machinery Industrial Clusters in South-East Region, Korea (동남권 기계.금속산업클러스터의 광역적 지원체계 구축전략)

  • Kwon, O--Hyeok
    • Journal of the Economic Geographical Society of Korea
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    • v.9 no.3
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    • pp.297-317
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    • 2006
  • This article is aimed to find a more successful way to build a metropolitan-wide governance for enhancing industrial cluster in South-East region, Korea. We begin a research with reviewing a current study of regional cluster and its governance. New industrial system and agglomeration changed regional growth theory and urban system. In traditional system, a central city dominated economy of the metropolitan area. However, with development of new transportation and communication technology, a central city lost their superiority to suburban cities. In other words, growing competition between central and suburban cities changed traditional concentration and diffusion theory of urbanization which dominated urban geography for last decades. Next, current situation of development of industrial cluster in South-East region is examined to suggest policy for more competitiveness. South-East region has grown as the most prominent cluster of mechanical engineering and metal industry in Korea since the late 1970s. In the form of agglomeration and network of a specific and its related industry, South-East region has formed a linear industrial belt along with the inter-regional South Coast Highway and contain about ten industrial cities. Accompanying with this growing South-East region, a problem has risen from geographic mismatch between metropolitan-wide industrial cluster and its administrative boundary. Since industrial cluster has no specific administrative boundary, adequate government support for developing industrial cluster has not been provided. Responding to the problem, academics and policy makers maintain need in establishing a metropolitan-wide governance for supporting a cluster. At the end, this paper provides some implication to planners and policy makers.

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Optical and Near-IR Photometry of the NGC 4874 Globular Cluster System with the Hubble Space Telescope

  • Cho, Hyejeon;Blakeslee, John P.;Peng, Eric W.;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.37.1-37.1
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    • 2013
  • We present our study of analyzing the photometric properties of the globular cluster (GC) system which resides in the extended halo of the central bright Coma cluster galaxy NGC 4874. The core of the Coma cluster of galaxies (Abell 1656) was observed with both the HST Advanced Camera for Surveys (ACS) in the F475W (g475) and F814W (I814) and Wide Field Camera 3 IR Channel (WFC3/IR) in the F160W (H160) filters. The data analysis procedure and GC candidate selection criteria are briefly described. We investigate the interesting "tilt" features in color-magnitude diagrams for this GC system and their link to the nonlinear color-metallicity relation for GCs. The NGC 4874's GC system exhibits a bimodal distribution in the optical g475-I814 color and much more than half the GCs fall in the red side at g475-I814 ~ 1.1. This bimodality is weakened in the optical-IR I814-H160 color; the quantitative analysis on the features of both color distributions using the Gaussian Mixture Modeling code proves the bimodalities are different. Both colors, thus, cannot linearly reflect the bimodality of an underlying metallicity, supporting the suggestion that observed bimodalities in extragalactic GC colors are the metallicity-to-color projection effect.

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Recovery Management of Split-Brain Group in Highly Available Cluster file System $\textrm{SANique}^{TM}$ (고가용성 클러스터 파일 시스템 $\textrm{SANique}^{TM}$의 분할그룹 탐지 및 회복 기법)

  • 이규웅
    • Journal of Korea Multimedia Society
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    • v.7 no.4
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    • pp.505-517
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    • 2004
  • This paper overviews the design details of the cluster file system $\textrm{SANique}^{TM}$ on the SAN environment. $\textrm{SANique}^{TM}$ has the capability of transferring user data from shared SAN disk to client application without control of centralized file server. We, especially, focus on the characteristics and functions of recovery manager CRM of $\textrm{SANique}^{TM}$. The process component for failure detection and its overall procedure are described. We define the split-brain problem that cannot be easily detected in cluster file systems and also propose the recovery management method based on SAN disk in order to detect and solve the split-brain situation.

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An Efficient Cluster Based Service Discovery Model for Mobile Ad hoc Network

  • Buvana, M.;Suganthi, M.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.680-699
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    • 2015
  • The use of web service has been increased rapidly, with an increase in the number of available services, finding the exact service is the challenging task. Service discovery is the most significant job to complete the service discoverers needs. In order to achieve the efficient service discovery, we focus on designing a cluster based service discovery model for service registering and service provisioning among all mobile nodes in a mobile ad hoc network (MANETs). A dynamic backbone of nodes (i.e. cluster heads) that forms a service repository to which MANET nodes can publish their services and/or send their service queries. The designed model is based on storing services with their service description on cluster head nodes that are found in accordance with the proposed cluster head election model. In addition to identifying and analyzing the system parameters for finding the effectiveness of our model, this paper studies the stability analysis of the network, overhead of the cluster, and bandwidth utilization and network traffic is evaluated using analytic derivations and experimental evaluation has been done.

Hydrodynamics Simulation of the Off-Axis Cluster Merger Abell 115

  • Lee, Wonki;Kim, Mincheol;Jee, M. James
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.60.3-61
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    • 2018
  • Abell 115 is a renowned cluster merger at z=0.197. It exhibits an asymmetric X-ray distribution with cometary tails and a megaparsec-sized radio relic stretching in the northeastern direction from the core of the northern cluster. Many observations have concluded that this cluster merger has a large impact parameter, but there has been no numerical analysis on the structure of Abell 115. In this study, we simulate Abell 115 with Gadget2 N-body/SPH code to reproduce the X-ray and weak lensing features of Abell 115. We find a new plausible merger scenario of Abell 115, wherein the northern cluster is currently in an outgoing phase. The predicted X-ray emission has a similar morphology to the observed tail of the northern cluster. However, in order to reproduce the observed line-of-sight velocity and projected distance while maintaining the two systems gravitationally bound, the system should possess a large projection angle, which makes the shock look considerably more diffused than the observed radio relic.

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Formation and Evolution of Ulsan Automobile Cluster (울산 자동차클러스터의 형성과 발전전망)

  • Lee, Jeong-Hyop
    • Journal of the Economic Geographical Society of Korea
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    • v.10 no.1
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    • pp.1-18
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    • 2007
  • This study examines the development direction of Ulsan automobile cluster and suggests strategic interventions, based on the possibility of system transformation in the open economic system. The spatial characteristics of global, national and local production and R&D networks were analyzed to investigate the conditions of Ulsan automobile cluster. And the agglomeration process of automobile industry and the capabilities accumulated in Ulsan were analyzed and alternative developmental path and policy suggestions were proposed.

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Bi-active Load Balancer for enhancing of scalability and fault-tolerance of Cluster System (확장성과 고장 감내를 위한 효율적인 부하 분산기)

  • Kim, Young-Hwan;Youn, Hee-Yong;Choo, Hyun-Seung
    • Annual Conference of KIPS
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    • 2002.04a
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    • pp.381-384
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    • 2002
  • This paper describes the motivation, design and performance of bi-active Load balancer in Linux Virtual Server. The goal of bi-active Load balancer is to provide a framework to build highly scalable, fault-tolerant services using a large cluster of commodity servers. The TCP/IP stack of Linux Kernel is extended to support three IP load balancing techniques, which can make parallel services of different kinds of server clusters to appear as a service on a single IP address. Scalability is achieved by transparently adding or removing a node in the cluster. and high availability is provided by detecting node or daemon failures and reconfiguring the system appropriately. Extensive simulation reveals that the proposed approach improves the reply rate about 20% compared to earlier design.

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Evaluation of Combustion Mechanism of Droplet Cluster in Premixed Spray Flame by Simultaneous Time-Series Measurement (동시 시계열 계측에 의한 예혼합 분무화염 내 유적군 연소기구의 평가)

  • Hwang, Seung-Min
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.6
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    • pp.442-448
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    • 2009
  • To evaluate the combustion mechanism of each droplet cluster downstream of the premixed spray flame, the simultaneous time-series measurements were conducted by using optical measurement system consisting of laser tomography, multi-color integrated Cassegrain receiving optics (MICRO) and phase Doppler anemometer (PDA). Furthermore, the group combustion number of droplet cluster was estimated experimentally, and the combustion mechanism of droplet cluster was examined applying the theoretical analysis. The group combustion number, $G_c$, was experimentally estimated about all droplet cluster verified by planar images, and it was classified into the internal group combustion mode and the external group combustion mode according to the theoretical analysis. It is found that there are cases in which the group combustion number estimated experimentally for droplet cluster agree or disagree with the classification by theoretical analysis. The reason of disagreement is considered due to that the group combustion number was only estimated by the geometrical arrangement of droplets in cluster, and that the actual phenomenon is three-dimensional but the measurement system is two-dimensional.

Study on a Model-based Design Technique for Monitoring and Control of a Vehicle Cluster (자동차 클러스터의 감시 및 제어를 위한 모델기반설계 기법 연구)

  • Kim, Dong Hun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.27 no.1
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    • pp.35-41
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    • 2017
  • This paper presents the development of a monitoring and control system for a vehicle cluster using a model-based design technique. For MBD(model-based design), MATLAB GUI(Graphic User Interface), M programs, simulink, state flow, and tool boxes are used to monitor a number of data such as warning, interrupts, and etc. connected to a real vehicle cluster. As a monitoring tool, a PC(Personal Computer) station interworks with the real vehicle cluster through the interface commands of tool boxes. Thus, unlike existing text-based designs, the MBD based vehicle cluster system provides very easy algorithm updates and addition, since it offers a number of blocks and state flow programs for each functional actions. Furthermore, the proposed MBD technique reduces the required time and cost for the development and modification of a vehicle cluster, because of verification and validation of the cluster algorithm on the monitor through a PC.

Recent Clinical Research on Acupuncture Therapy for Cluster Headache (군발성 두통에 대한 최근 침치료 연구 동향)

  • Sung-eun Kim;Ae-ri Lee;In Lee
    • The Journal of Internal Korean Medicine
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    • v.44 no.6
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    • pp.1197-1211
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    • 2023
  • Objectives: This study presents evidence by analyzing the research trends in acupuncture treatment for cluster headache in the last 10 years. Methods: Randomized controlled trials (RCTs) about acupuncture for cluster headache were searched from the China National Knowledge Infrastructure, PubMed, Cochrane Library, Oriental Medicine Advanced Searching Integrated System, ScienceON, Korean Studies Information Service System, and Research Information Sharing Service. The search terms were the combinations of "cluster headache", "acupuncture", and "needle therapy", and the articles were restricted to those published between 2013 and 2023. Only RCTs were selected. The risk of bias (RoB) was assessed according to the revised Cochrane RoB2 criteria. Results: Six RCTs were selected and analyzed in this review. All selected studies were conducted in China. All RCTs comprised 628 participants. Manual acupuncture was used in all studies. Acupuncture targeting the sphenopalatine ganglion was performed in two papers published after 2020. ST8, Ex-HIN3, and GB14 were the most frequently used acupoints in acupuncture treatment. The most commonly used indicators for evaluation were headache attack frequency, clinical efficacy, and the visual analog scale. In each study, adding acupuncture treatment to conventional therapy had significant effects in relieving the symptoms of cluster headaches. Conclusion: The results suggest that acupuncture is an effective treatment for cluster headache. To ensure objective evidence for the effectiveness of acupuncture treatment in cluster headache, it is important to continue large-scale case reports and RCTs.