• Title/Summary/Keyword: Cluster Formation

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The Formation of Innovative Clusters in Kazakhstan: Analysis and Methods for Identifying Specialization

  • Kireyeva, Anel A.;Nurlanova, Nailya K.
    • The Journal of Asian Finance, Economics and Business
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    • v.1 no.1
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    • pp.23-30
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    • 2014
  • The aim of this research is theoretical and methodological approaches to the necessity of formation of innovation clusters as growth poles on the basis of statistical analysis and identification of specialization. In this research, we used methods, which will allow to analyze of innovative processes and to identify of prospective branches of specialization of the formation of innovative clusters in the spatial context. Keeping with the previous literature, the present study is determined by the novelty of the problem, concerning the formation and development of innovative clusters as growth poles, as well as large specifics of problems in our country in the framework of use of innovative clusters. An analysis was showed that Kazakhstan's regions have substantial differences in the groups of regions for most of the indicators have presented form a tightly located clusters and in the ratings of innovative susceptibility and innovative activity. This research has some practical implications, which have proved that innovative clusters become platforms as growth poles for introduction of advanced technologies, development of innovative companies, thereby providing a certain stability of the economy of the regions.

Deep Impact: Molecular Gas Properties under Strong Ram Pressure Probed by High-Resolution Radio Interferometric Observations

  • Lee, Bumhyun;Chun, Aeree
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.39.3-39.3
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    • 2019
  • Ram pressure stripping due to the intracluster medium (ICM) is an important environmental process, which causes star formation quenching by effectively removing cold interstellar gas from galaxies in dense environments. The evidence of diffuse atomic gas stripping has been reported in several HI imaging studies. However, it is still under debate whether molecular gas (i.e., a more direct ingredient for star formation) can be also affected and/or stripped by ram pressure. The goal of this thesis is to understand the impact of ram pressure on the molecular gas content of cluster galaxies and hence star formation activity. To achieve this, we conducted a series of detailed studies on the molecular gas properties of three Virgo spiral galaxies with clear signs of active HI gas stripping (NGC 4330, NGC 4402, and NGC 4522) based on high-resolution CO data obtained from the Submillimeter Array (SMA) and Atacama Large Millimeter/submillimeter Array (ALMA). As a result, we find the evidence that the molecular gas disk also gets affected by ram pressure in similar ways as HI even well inside of the stellar disk. In addition, we detected extraplanar 13CO clumps in one of the sample, which is the first case ever reported in ram pressure stripped galaxies. By analyzing multi-wavelength data (e.g., Hα, UV, HI, and CO), we discuss detailed processes of how ram pressure affects star formation activities and hence evolution of cluster galaxies. We also discuss the origin of extraplanar 13CO, and how ram pressure can potentially contribute to the chemical evolution of the ICM.

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The Phase Analysis of MgB2 Fabricated by Spark Plasma Sintering after Ball Milling (볼 밀링 후 방전플라즈마 소결법에 의해 제조된 MgB2의 상 분석)

  • Kang, Deuk-Kyun;Choi, Sung-Hyun;Ahn, In-Shup
    • Journal of Powder Materials
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    • v.15 no.5
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    • pp.371-377
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    • 2008
  • This paper deals with the phase analysis of $MgB_2$ bulk using spark plasma sintering process after ball milling. Mg and amorphous B powders were used as raw materials, and milled by planetary-mill for 9 hours at argon atmosphere. In order to confirm formation of $MgB_2$ phase, DTA and XRD were used. The milled powders were fabricated to $MgB_2$ bulk at the various temperatures by Spark Plasma Sintering. The fabricated $MgB_2$ bulk was evaluated with XRD, EDS, FE-SEM and PPMS. In the DTA result, reaction on formation of $MgB_2$ phase started at $340^{\circ}C$. This means that ball milling process improves reactivity on formation of $MgB_2$ phase. The $MgB_2$ MgO and FeB phases were characterized from XRD result. MgO and FeB were undesirable phases which affect formation of $MgB_2$ phase, and it's distribution could be confirmed from EDS mapping result. Spark Plasma Sintered sample for 5 min at $700^{\circ}C$ was relatively densified and it's density and transition temperature showing super conducting property were $1.87\;g/cm^3$ and 21K.

The Study on the Strategy for the Formation of the Innovation Clusters - Focused on the Scenario Planning of the 'Pankyo TechnoValley'- (기술혁신 클러스터 구축의 전략방향 설정에 관한 연구 - '판교 테크노밸리' 시나라오 플래닝을 중심으로 -)

  • Lee, Won-Il;Yim, Deok-Soon;Lee, Yeon-Hee;Jung, Eui-Jeong
    • Journal of Korea Technology Innovation Society
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    • v.14 no.2
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    • pp.301-319
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    • 2011
  • This research focused on the strategy consulting of the 'Pankyo Technovalley' for the formation of the innovation clusters The study was performed based on both theoretical study and related qualitative study approaches. Particularly, 'scenario planning' as a foresight method was used for the strategy formulation of the innovation clusters. The major determinants for the success of the formation of the innovation clusters can be summarized as follows; the enhancement of the service of the host institution of clusters, the alignment of the national cluster policy with the strategy of the host institution and the networks of the clusters. In terms of the needs of times, this study regarding the strategy for the formation of the innovation clusters is anticipated to be a good reference for the R&D organizations and technology cluster participants in coming years.

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STAR FORMATION ACTIVITY OF GALAXIES UNDERGOING RAM PRESSURE STRIPPING IN THE VIRGO CLUSTER

  • Mun, Jae Yeon;Hwang, Ho Seong;Lee, Myung Gyoon;Chung, Aeree;Yoon, Hyein;Lee, Jong Chul
    • Journal of The Korean Astronomical Society
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    • v.54 no.1
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    • pp.17-35
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    • 2021
  • We study galaxies undergoing ram pressure stripping in the Virgo cluster to examine whether we can identify any discernible trend in their star formation activity. We first use 48 galaxies undergoing different stages of stripping based on H i morphology, H i deficiency, and relative extent to the stellar disk, from the VIVA survey. We then employ a new scheme for galaxy classification which combines H i mass fractions and locations in projected phase space, resulting in a new sample of 365 galaxies. We utilize a variety of star formation tracers, which include g - r, WISE [3.4]-[12] colors, and starburstiness that are defined by stellar mass and star formation rates to compare the star formation activity of galaxies at different stripping stages. We find no clear evidence for enhancement in the integrated star formation activity of galaxies undergoing early to active stripping. We are instead able to capture the overall quenching of star formation activity with increasing degree of ram pressure stripping, in agreement with previous studies. Our results suggest that if there is any ram pressure stripping induced enhancement, it is at best locally modest, and galaxies undergoing enhancement make up a small fraction of the total sample. Our results also indicate that it is possible to trace galaxies at different stages of stripping with the combination of H i gas content and location in projected phase space, which can be extended to other galaxy clusters that lack high-resolution H i imaging.

How did the peculiar S0 galaxy M85 form?

  • Ko, Youkyung;Lee, Myung Gyoon;Sohn, Jubee;Ryu, Jinhyuk;Jang, In Sung;Lim, Sungsoon;Park, Hong Soo;Hwang, Narae;Park, Byeong-Gon
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.46.1-46.1
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    • 2015
  • M85 is a merger remnant galaxy in the Virgo Cluster, showing complex merging features. Globular clusters in M85 are a good tracer of its merging history. To investigate globular cluster system of M85, we obtain deep and wide field images of M85 in ugi filters covering one square degree using CFHT/MegaCam. We discover about 1,000 globular cluster candidates in these images. The color distribution of the globular cluster candidates within r < 5' from M85 does not show a clear bimodality and blue globular cluster candidates are more than red ones. These features are different from those in massive early-type galaxies. The spatial distribution of the globular cluster candidates is elongated along the faint stellar light of M85. We also investigate the spatial distribution of sub-populations of the globular cluster candidates with different color and brightness and estimate their ages based on their color. We discuss these results in relation with the formation history of M85.

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Location-Based Spiral Clustering Algorithm for Avoiding Inter-Cluster Collisions in WSNs

  • Yun, Young-Uk;Choi, Jae-Kark;Yoo, Sang-Jo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.4
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    • pp.665-683
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    • 2011
  • Wireless sensor networks (WSN) consist of a large amount of sensor nodes distributed in a certain region. Due to the limited battery power of a sensor node, lots of energy-efficient schemes have been studied. Clustering is primarily used for energy efficiency purpose. However, clustering in WSNs faces several unattained issues, such as ensuring connectivity and scheduling inter-cluster transmissions. In this paper, we propose a location-based spiral clustering (LBSC) algorithm for improving connectivity and avoiding inter-cluster collisions. It also provides reliable location aware routing paths from all cluster heads to a sink node during cluster formation. Proposed algorithm can simultaneously make clusters in four spiral directions from the center of sensor field by using the location information and residual energy level of neighbor sensor nodes. Three logical addresses are used for categorizing the clusters into four global groups and scheduling the intra- and inter-cluster transmission time for each cluster. We evaluated the performance with simulations and compared it with other algorithms.

Promoting Strategies by Development Stage of Region Based Agricultural Cluster Using a Multi-disciplinary Approach (다학문적 접근을 통한 지역농업 클러스터의 단계별 추진전략)

  • Choi, Sang-Ho;Choi, Hung-Kyu;Lee, Min-Soo;Choe, Young-Chan
    • Journal of Korean Society of Rural Planning
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    • v.11 no.4 s.29
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    • pp.33-45
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    • 2005
  • This study investigates the core elements of the formation and development of cluster using a multi-disciplinary approach and suggests a promoting strategy by development stage of cluster. As a sub-category of regional innovation system, the cluster has been considered as one of the most noticeable methodological argument to make the regional innovation system come true. In the meantime, this study examines the core elements of cluster shown in the theories and examples through six academic fields such as economics, geography, regional development, business administration, sociology and pedagogy and their educational back-ground. By means of establishing the incubation stage in the development of cluster, core elements are composed in the stages of birth, incubation and evolution in subsequent manner. A promoting strategy will be suggested through the implication of core elements in the reestablished stages.