• Title/Summary/Keyword: Clusters System

Search Result 827, Processing Time 0.017 seconds

A Conceptual Model of Port Clusters and Related Assemblages

  • Roh Hong-Seung
    • Journal of Navigation and Port Research
    • /
    • v.30 no.2
    • /
    • pp.145-150
    • /
    • 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.

THE STAR CLUSTER SYSTEM OF THE MERGING GALAXY NGC 1487

  • Lee, Hye-Jin;Lee, Myung-Gyoon
    • Journal of The Korean Astronomical Society
    • /
    • v.38 no.3
    • /
    • pp.345-355
    • /
    • 2005
  • We present a photometric study of the star cluster system in the merging galaxy NGC 1487, based on the BI photometry obtained from the F450W and F814W images in the HST /WFPC2 archive data. We have found about 560 star cluster candidates in NGC 1487, using the morphological parameters of the objects. We have investigated several photometric characteristics of the clusters: color-magnitude diagrams (CMDs), color distribution, spatial distribution, age, size and luminosity function. The CMD of the bright clusters with 18.5 < B < 24 mag in NGC 1487 shows three major populations of clusters: a blue cluster population with $(B-I){\le}0.45$, an intermediate-color cluster population with $0.45<(B-I){\le}1.55$, and a red cluster population with (B - I) > 1.55. The intermediate-color population is the most dominant among the three populations. The brightest clusters in the blue and intermediate- color populations are as bright as $B{\approx}18mag$ ($M_B{\approx}-12mag$), which are three magnitudes brighter than those in the red population. The blue and intermediate-color clusters are strongly concentrated on the bright condensations, while the red clusters are relatively more scattered over the galaxy. The CMD of these clusters is found to be remarkably similar to that of the clusters in the famous interacting system M51. From this we suggest that the intermediate-color clusters were, probably, formed during the merging process which occurred about 500 Myrs ago.

Group Search Optimization Data Clustering Using Silhouette (실루엣을 적용한 그룹탐색 최적화 데이터클러스터링)

  • Kim, Sung-Soo;Baek, Jun-Young;Kang, Bum-Soo
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.42 no.3
    • /
    • pp.25-34
    • /
    • 2017
  • K-means is a popular and efficient data clustering method that only uses intra-cluster distance to establish a valid index with a previously fixed number of clusters. K-means is useless without a suitable number of clusters for unsupervised data. This paper aimsto propose the Group Search Optimization (GSO) using Silhouette to find the optimal data clustering solution with a number of clusters for unsupervised data. Silhouette can be used as valid index to decide the number of clusters and optimal solution by simultaneously considering intra- and inter-cluster distances. The performance of GSO using Silhouette is validated through several experiment and analysis of data sets.

The Formation of Information Technology Clusters in Kazakhstan: System and Structured Approaches

  • Kireyeva, Anel A.
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.3 no.2
    • /
    • pp.51-57
    • /
    • 2016
  • The aim of this study is to examine of the cluster approach to ensure high rates of innovation, information and communication enterprises of information technology cluster in order to enhance the competitiveness of regions. Keeping with the previous literature, the present research determined that the novelty of the problem, concerning of the creation IT clusters as drivers of new generation, i.e. a kind of platform of "startup accelerators" through the creation of previously not existing in the country high-tech industries and sectors of the economy. The study employs system approach involves to determine prospective directions of the formation of clusters of IT industry, also applies structured approach to shows relationships between elements of cluster systems (participants of cluster), as well as focusing on some aspects of cluster development such as networking. Based on this analysis we have proposed to create clusters in regions, which can play the role of translator's innovations at the periphery of the country. This research shows that formation of IT clusters is one of the most successful tools to avoid of dependence of Kazakhstan from raw materials.

The Mechanism of Gold Deposition by Thermal Evaporation

  • Mark C. Barnes;Kim, Doh-Y.;Nong M. Hwang
    • Proceedings of the Korea Association of Crystal Growth Conference
    • /
    • 2000.06a
    • /
    • pp.127-142
    • /
    • 2000
  • The charged cluster model states that chemical vapor deposition (CVD) begins with gas phase nucleation of charged clusters followed by cluster deposition on a substrate surface to form a thin film. A two-chambered CVD system, separated by a 1-mm orifice, was used to study gold deposition by thermal evaporation in order to determine if the CCM applies in this case. At a filament temperature of 1523 and 1773 K, the presence of nano-meter sized gold clusters was found to be positive and the cluster size and size distribution increased with increasing temperature. Small clusters were found to be amorphous and they combined with clusters already deposited on a substrate surface to form larger amorphous clusters on the surface. This work revealed that gold thin films deposited on a mica surface are the result of the sticking of 4-10 nm clusters. The topography of these films was similar to those reported previously under similar conditions.

  • PDF

스웨덴의 지역혁신체제 및 클러스터 육성정책

  • 박상철
    • Journal of Technology Innovation
    • /
    • v.11 no.1
    • /
    • pp.195-214
    • /
    • 2003
  • Sweden's regional innovation system is built mainly on innovative clusters, several of them - in automobile, steel, new materials, information and telecommunication, and bioscience - world-class. Most successful clusters were developed at local bases imbued with local history. In fact, a cluster's competitiveness is intimately related to its closeness of fit with its local environment. Geographically dispersed clusters in Sweden - some national, others local, and some local but deemed members of a national cluster as well - have already created many new competitive products and services. In 2001, Sweden has eight national and nine regional clusters, and envisioned eleven national and five regional clusters more. The experience of Swedish clusters indicate several elements that determine the ability of cluster policies to promote and strengthen regional economic growth. Cluster policies require strong public sector support, particularly in the form of providing basic national conditions. Regional cluster policies place new demands on national and regional industrial policies. All policies must be closely interwoven without compromising their primary allegiance to their respective areas.

  • PDF

The Effect of the Number of Clusters on Speech Recognition with Clustering by ART2/LBG

  • Lee, Chang-Young
    • Phonetics and Speech Sciences
    • /
    • v.1 no.2
    • /
    • pp.3-8
    • /
    • 2009
  • In an effort to improve speech recognition, we investigated the effect of the number of clusters. In usual LBG clustering, the number of codebook clusters is doubled on each bifurcation and hence cannot be chosen arbitrarily in a natural way. To have the number of clusters at our control, we combined adaptive resonance theory (ART2) with LBG and perform the clustering in two stages. The codebook thus formed was used in subsequent processing of fuzzy vector quantization (FVQ) and HMM for speech recognition tests. Compared to conventional LBG, our method was shown to reduce the best recognition error rate by 0${\sim$}0.9% depending on the vocabulary size. The result also showed that between 400 and 800 would be the optimal number of clusters in the limit of small and large vocabulary speech recognitions of isolated words, respectively.

  • PDF

Emerging Green Clusters in South Korea? The Case of the Wind Power Cluster in Jeonbuk Province

  • Berg, Su-Hyun;Hassink, Robert
    • STI Policy Review
    • /
    • v.3 no.1
    • /
    • pp.63-79
    • /
    • 2012
  • Regional innovation systems and clusters represent a fashionable conceptual basis for regional innovation policies in many industrialized countries (including South Korea). Due to questions related to climate change and environment-friendly energy production, the green industry has been increasingly discussed in relation to regional innovation systems and clusters. This explorative paper analyzes these discussions and critically examines the emergence of green clusters in South Korea based on the case of the wind power cluster in Jeonbuk Province. It tentatively concludes that the role of the central government is too powerful and the role of regional actors (policy-makers and entrepreneurs) is too weak for the successful emergence of green clusters.

A Case Study of Regional Industry Clusters : Clusters Estimate Index and Policy (지역산업클러스터 사례연구 : 클러스터 평가지표와 정책과제)

  • Won, Gu-Hyun
    • Korean Business Review
    • /
    • v.18 no.2
    • /
    • pp.197-223
    • /
    • 2005
  • The industrial cluster policy of 21st century rise to the focus method of regional economic promotion, therefore, the importance of study in cluster identification and mapping as policy task will bring into relief. This paper will confirms the estimate index and policy of industrial clusters with regional industry. The result in this case study, Cluster development should embrace the pursuit of competitive advantage and specialization rather than simply imitate successful clusters in other locations. This requires building on local sources of uniqueness. Government should reinforce and building on existing and emerging clusters rather than attempt to create entirely new ones. This sort of role for government is very different from industrial policy. The aim of cluster policy is to reinforce the development of all clusters. Not all clusters will succeed, but market forces should determine the outcomes. In other words, government should build on market- oriented system and innovative infra. The result of this study is meaning to the development of objectivity estimate index and derivation of cluster-focused policy with a case study of industrial clusters.

  • PDF

Spectroscopic Confirmation of Galaxy Clusters at z~0.92

  • Kim, Jae-Woo;Im, Myungshin;Lee, Seong-Kook;Hyun, Minhee
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.1
    • /
    • pp.45.1-45.1
    • /
    • 2015
  • Galaxy clusters have provided important information to understand the evolution of the universe, since the number density and mass of clusters are tightly related to the cosmological parameters. In addition, galaxy clusters are an excellent laboratory to investigate the galaxy evolution in dense environments. However, finding galaxy clusters at high redshift ($z{\geq}1$) still remains as a main subject in astronomy due to their rareness and difficulty in identifying such objects from optical imaging data alone. Here, we report a spectroscopic follow-up observation of distant galaxy cluster candidates identified by a deep optical-NIR dataset of Infrared Medium-deep Survey. Through the galaxy spectra taken with the IMACS instrument on the Magellan telescope, we confirm at least 3 massive clusters at z~0.92. Interestingly, the maximum spatial separation between these clusters is ~8Mpc, which implies that this system is a new supercluster in the distant universe. We also discuss properties of galaxies in these clusters based on multi-wavelength photometric data.

  • PDF