• Title/Summary/Keyword: clusters

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A Study on the Types and Characteristics of Global Fashion Clusters (글로벌 패션 산업 클러스터의 유형과 특성에 대한 연구)

  • Yun, So Jung;Lee, Ha Kyung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.43 no.4
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    • pp.491-505
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    • 2019
  • This study analyzes global fashion clusters to provide insight for the domestic fashion market to form a competitive fashion cluster. We examine formation factors and operation types of the global fashion clusters to understand their characteristics. We also explore the effectiveness of each global fashion cluster by investigating the stage of development in fashion clusters. Fourteen cases of global fashion clusters are collected and analyzed. First, global fashion clusters show three types of formation and operation: self-formation, self-formation & government based development, and government, institute, and enterprise based formation & development. Second, the characteristics of global fashion clusters are based on functions related to space, learning, innovation, network, and knowledge. Third, there are four steps in the development stage of global fashion clusters: professional clusters, industrial clusters, learning clusters and innovative industrial clusters. In particular, innovative industrial clusters, the final stage of development, have high levels of effectiveness in terms of co-growth and collaboration among fashion-related businesses in fashion clusters. The results of this study can help guide the development of local fashion cluster in Korea.

Are There Any Old Globular Clusters in the Starburst Galaxy M82?

  • Lim, Sung-Soon;Hwang, Na-Rae;Lee, Myung-Gyoon
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.63.1-63.1
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    • 2011
  • M82 is a famous starburst galaxy which is dominated by young stellar populations and ISM. Some previous studies indicated the existence of intermediate-age and old stellar population in this galaxy, but little is known about them. We present a study of old globular clusters in M82 using the Hubble Space Telescope archive data. From the cluster survey of M82 we found 650 star clusters. We divided them into disk and halo star clusters according to their position. The color-color diagrams show that all 19 halo star clusters are old globular clusters. The disk sample may include both reddened young clusters and geniune old globular clusters. We estimated their ages using spectral energy distribution fit method with six filter data covering from ultraviolet (F330W) to infrared (F160W), and found that 30 of them are older than 3 Gyr. These are considered to be disk globular clusters. Twelve of the halo globular clusters are found to be partially resolved into their member stars. The (B-V) color range of the halo globular clusters is consistent with that of the Milky Way globular clusters, but most of M82 globular clusters are bluer than (B-V)=0.7. The existence of these old globular clusters suggests that the starburst galaxy M82 has an old stellar halo that may be as old as the Milky Way halo.

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A Conceptual Model of Port Clusters and Related Assemblages

  • Roh Hong-Seung
    • Journal of Navigation and Port Research
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    • v.30 no.2
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    • pp.145-150
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    • 2006
  • Recently we have seen a noticeable trend in ports to establish port clusters. Despite this trend, little research has actually been undertaken to fully define and analyse port clusters. A couple of exceptions have descriptively defined port clusters but the boundaries of port clusters are not apparent. Therefore, the aim of this paper is to define port clusters in terms of set theory and in particular look at them in terms of their distinct characteristics and system boundaries. The main concern of this paper is that there is a need to distinguish, from a system and a competition perspective, between port clusters, ports, maritime clusters and port ranges. This paper proposes a conceptual model relevant to the relationship among port clusters related assemblages and that has been applied to the north western europe region This model suggests six levels of competition that will help port authorities and government to develop appropriate policies and strategies for port operation and port industry.

A Study on the Knowledge-Sharing Networks in Clusters to Enhance the Competitiveness of Industrial Parks (산업단지의 경쟁력 제고를 위한 산업집적지의 지식공유 네트워크에 관한 연구)

  • Jeong, Jongsik
    • Knowledge Management Research
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    • v.2 no.1
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    • pp.133-144
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    • 2001
  • Clusters mean geographic concentrations of interconnected companies and institutions in a particular field. Geographic, cultural, and institutional proximity provides companies with special access, closer relationships, better information, powerful incentives, and other advantages that are difficult to tap from a distance. And clusters are the knowledge-sharing networks which are composed of co-existence of related industries and supporting industries, sophisticated demand, sponsor of various exhibitions and events, liaison of peripheries and clusters, liaison of clusters and clusters, and governments' willingness for promoting clusters' development.

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On Clusters: External and Internal Perspectives

  • Ffowcs-Williams, Ifor
    • World Technopolis Review
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    • v.1 no.3
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    • pp.158-176
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    • 2012
  • This paper examines the phenomenon of local clusters in two dimensions. Firstly an external perspective on clusters is taken, the origins of clusters identified and their significance for economic development highlighted. Secondly, the paper takes an inside look at clusters, exploring the key factors that lead to the success of strong, high performance clusters.

Extra-tidal stars around globular clusters NGC 5024 and NGC 5053 and their chemical abundances

  • Chun, Sang-Hyun;Lee, Jae-Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.40.2-40.2
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    • 2018
  • NGC 5024 and NGC 5053 are among the most metal-poor globular clusters in the Milky Way. Both globular clusters are considered to be accreted from dwarf galaxies (like Sagittarius dwarf galaxy or Magellanic clouds), and common stellar envelope and tidal tails between globular clusters are also detected. We present a search for extra-tidal cluster member candidates around these globular clusters from APOGEE survey data. Using 20 chemical elements (e.g., Fe, C, Mg, Al) and radial velocities, t-distributed stochastic neighbour embedding (t-SNE), which identifies an optimal mapping of a high-dimensional space into fewer dimensions, was explored, and we find that globular cluster stars are well separated from the field stars in 2-dimensional map from t-SNE. We also find that some stars selected in t-SNE map are placed outside of the tidal radius of the clusters. The proper motion of stars outside tidal radius is also comparable to that of globular clusters, which suggest that these stars are tidally decoupled from the globular clusters. We manually measure chemical abundances for the clusters and extra-tidal stars, and discuss the association of extra-tidal stars with the clusters.

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The Roles of Intermediaries in Clusters: The Thai Experiences in High-tech and Community-based Clusters

  • Intarakumnerd, Patarapong
    • Journal of Technology Innovation
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    • v.13 no.2
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    • pp.23-43
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    • 2005
  • Industrial clusters are geographical concentrations of interconnected companies, specialised suppliers, service providers, firms in related industries, and associated institutions (for example, universities, standard agencies, and trade associations) that combine to create new products and/or services in specific lines of business. At present, the concept of industrial cluster becomes very popular worldwide, policy makers at national, regional and local levels and business people in both forerunner and latecomer countries are keen to implement the cluster concept as an economic development model. Though understanding of clusters and related promoting policies varies from one place to another, the underlying benefits of clusters from collective learning and knowledge spillovers between participating actors strongly attract the attention of these people. In Thailand, a latecomer country in terms of technological catching up, the cluster concept has been used as a means to rectify weakness and fragmentation of its innovation systems. The present Thai government aspires to apply the concept to promote both high-tech manufacturing clusters, services clusters and community-based clusters at the grass-root level. This paper analyses three very different clusters in terms of technological sophistication and business objectives, i.e., hard disk drive, software and chili paste. It portrays their significant actors, the extent of interaction among them and the evolution of the clusters. Though are very dissimilar, common characteristics attributed to qualified success are found. Main driving forces of the three clusters are cluster intermediaries. Forms of these organizations are different from a government research and technology organization (RTO), an industrial association, to a self-organised community-based organization. However, they perform similar functions of stimulating information and knowledge sharing, and building trust among participating firms/individuals in the clusters. Literature in the cluster studies argues that government policies need to be cluster specific. In this case, the best way to design and implement cluster-specific policies is through working closely with intermediaries and strengthening their institutional especially in linking member firms/individuals to other actors in clusters such as universities, government R&D institutes, and financial institutions.

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CORRELATION FUNCTIONS OF THE ABELL, APM, AND X-RAY CLUSTERS OF GALAXIES

  • LEE SUNGHO;PARK CHANGBOM
    • Journal of The Korean Astronomical Society
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    • v.35 no.3
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    • pp.111-121
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    • 2002
  • We have measured the correlation functions of the optically selected clusters of galaxies in the Abell and the APM catalogs, and of the X-ray clusters in the X-ray-Brightest Abell-type Clusters of galaxies (XBACs) catalog and the Brightest Clusters Sample (BCS). The same analysis method and the same method of characterizing the resulting correlation functions are applied to all observational samples. We have found that the amplitude of the correlation function of the APM clusters is much higher than what has been previously claimed, in particular for richer subsamples. The correlation length of the APM clusters with the richness R $\ge$ 70 (as defined by the APM team) is found to be $r_0 = 25.4_{-3.0}^{+3.1}\;h^{-1}$ Mpc. The amplitude of correlation function is about 2.4 times higher than that of Croft et al. (1997). The correlation lengths of the Abell clusters with the richness class RC $\ge$ 0 and 1 are measured to be $r_0 = 17.4_{-1.1}^{+1.2}$ and $21.0_{-2.8}^{+2.8}\;h^{-1}$ Mpc, respectively, which is consistent with our results for the APM sample at the similar level of richness. The richness dependence of cluster correlations is found to be $r_0= 0.40d_c + 3.2$ where $d_c$ is the mean intercluster separation. This is identical in slope with the Bahcall & West (1992)'s estimate, but is inconsistent with the weak dependence of Croft et al. (1997). The X-ray bright Abell clusters in the XBACs catalog and the X-ray selected clusters in the BCS catalog show strong clustering. The correlation length of the XBACs clusters with $L_x {\ge}0.65{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.3_{-6.5}^{+8.2}\;h^{-1}$ Mpc, and that of the BCS clusters with $L_x {\ge}0.70{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.2_{-8.9}^{+9.8}\;h^{-1}$ Mpc. The clustering strength of the X-ray clusters is much weaker than what is expected from the optical clusters.

TIDAL TAILS OF GLOBULAR CLUSTERS

  • YIM KI-JEONG;LEE HYUNG MOK
    • Journal of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.75-85
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    • 2002
  • We present N-body simulations of globular clusters including gravitational field of the Galaxy, in order to study effects of tidal field systematically on the shape of outer parts of globular clusters using NBODY6. The Galaxy is assumed to be composed of central bulge and outer halo. We mvestigate the cluster of multi-mass models with a power-law initial mass function (IMF) starting with different initial masses, initial number of particles, different slopes of the IMF and different orbits of the cluster. We have examined the general evolution of the clusters, the shape of outer parts of the clusters, density profiles and the direction of tidal tails. The density profiles appear to become somewhat shallower just outside the tidal boundary consistent with some observed data. The position angle of the tidal tall depends on the location in the Galaxy as well as the direction of the motion of. clusters. We found that the clusters become more elongated at the apogalacticon than at the pengalacticon. The tidal tails may be used to trace the orbital paths of globular clusters.

MASS TO LUMINOSITY RATIONS OF SOME CLUSTERS IN THE LARGE MAGELLANIC CLOUD

  • Sohn, Young-Jong;Chun, Mun-Suk
    • Journal of Astronomy and Space Sciences
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    • v.7 no.2
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    • pp.125-139
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    • 1990
  • Luminosity profiles and dynamical parameters of 12 globular clusters in the Large Magellanic Cloud(SB(s)m) are obtained from the concentric aperture photoelectric photometry of 3 different aged clusters and the collected photometric data of 9 clusters. The total masses of the globular clusters are calculated using the equation $M_\bigoplus$= ${Mr_t}^j(4\Omega^2-k^2)$, which is derived from the theroetical rotation curve for the exponential disk(Chun 1978). These masses lie between $0.3\times10^4$ and $15.8\times10^4M_\bigoplus$. From the determined total mass and luminosity, the mass-to-luminosity ratios are also derived. The M/L ratio of a cluster increases with the cluster age ; about 0.03 for the youngest clusters(SWB I) and about 0.24 for the oldest clusters (SWB VII). There is a difference in M/L by a factor of 10 between the galactic globular clusters and the old globular clusters in the LMC.

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