• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1064-1072
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• 2005

For the efficient operation of sensor networks, it is very important to design sensor networks for sensors to utilize their energies in very effective ways. Cluster-based routing schemes such as LEACH can achieve their energy efficiencies by delivering data between cluster heads and sensor nodes. In those cluster-based schemes, cluster reconfiguration algorithm is one of the most critical issues to achieve longer operation lifetime of sensor networks. In this paper, we propose a new energy efficient cluster reconfiguration algorithm. Proposed method does not require any location or energy information of sensors, and can configure clusters with fair cluster regions such that all the sensors in a sensor network can utilize their energies equally. The performances of the proposed scheme have been compared with LEACH and LEACH-C.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.2
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• pp.214-235
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• 2019

This study adopts the concept of social innovation cluster in which social economy organizations as one of the emerging axes of economic systems operate in collaboration with government agencies, investment institutions, intermediate supporting organizations and non-profit organizations, and investigates how the clusters of this kind grow in the context of the Korean socio-economic situation for the cases of Seongdong-gu and Eunpyeong-gu in Seoul, Korea. For this purpose, it has identified the actors of the clusters and their internal relations, and analyzed the process of cluster formation. A social network analysis of the partnerships between the actors has shown that Seongdong-gu has more diversified types of the network participation of universities, global networks and investment institutions than Eunpyeong-gu. It is interpreted that this pattern has resulted from the domination of private organizations in the former area, which is also confirmed by in-depth interviews with persons involved in the clusters. Although the facets of social innovation clusters are manifested in both areas, even in their initial stage, such factors as linkages between industrial actors and convergence with other clusters, which appear in the maturing stage of cluster formation, has yet to be found. It is suggested that the sustainable growth of social innovation clusters should be accompanied by information sharing and cooperation between the two areas on the future orientation of development.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.5
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• pp.385-393
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• 2004

Cluster systems have been widely used for solving problems in various application domains, and regarded as useful high performance computing resources. As the number of cluster system user is increasing, it is no less important to maintain stable operation than to improve cluster system performance. Although hardware preventive maintenance is important for keeping normal operation, the testing tool which can be used for general cluster systems during maintenance has received little attention. In this Paper, considering hardware Preventive maintenance, we suggest a testing tool for hardware of cluster system. The cluster system testing tool which is named CTS(Cluster system Test Suite) has two check routines; one for memory, and the other for NIC respectively. The CTS is designed to support the common features of general cluster systems and all the Jobs such as setting test conditions to querying the results can be done entirely within an integrated GUI environment. CTS is used as the testing tool for two kinds of cluster systems during maintenance, and the experimental results show that CTS reports useful information for cluster systems management.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.87-91
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• 2019

WSN is a wirelessly configured network of sensor nodes with limited power such as batteries. If the sensor node's battery is exhausted, the node is no longer available. Therefore, if the network is to be used for a long time, energy consumption should be minimized. There are many Wireless Sensor Network Protocols to improve energy efficiency, including Cluster-based and chain-based Protocols. Cluster-based Protocols elect Cluster Heads and divide sensor field into Clusters. The Cluster Head collects the data in the Cluster and transmits it to the Base Station. In the case of nodes elected as Cluster Heads, there is a problem of energy consumption. The chain-based Protocol links sensor nodes in a chain and finally transmits all data to the Base Station. In this paper, we intend to increase the network lifetime by using a chain to reduce the energy consumption of the Cluster Head in the Cluster-based Protocol, LEACH Protocol.

• Journal of the Korean association of regional geographers
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• v.18 no.3
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• pp.298-309
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• 2012

This paper studies the characteristics of the network of the Zhongguancun Cluster, the most representative innovative cluster of the high-tech industry in China at present. For this study, Zhongguancun Cluster was the first high-tech cluster created in China in 1988, the current Zhongguancun Cluster plays a leading role in the development of the high-tech industry in China. In addition, the Zhongguancun Cluster has attracted global attention and helped elevate China as a key region in terms of research development in relation to the high-tech industry. With regard to the spatial characteristics of the network belonging to the companies in Zhongguancun Cluster, purchase and producer services and information and R&D network have a strong tendency to be local, while on the other hand the product sales network has a strong tendency to be non-local. It is because the political support supplied by the government, institutional base that provides high-tech companies, producer services and information regarding producer services is relatively well prepared and managed in Zhongguancun Cluster. The spatial characteristics of the R&D network have a very strong local character is due to the location of the Zhongguancun Cluster where companies, universities and research centers with outstanding research development capacity as well as various support organizations for technology innovation within the cluster are included. On the other hand, because the high-tech products produced in this area are sold all across China as well as in foreign countries, the product sales network has a strong non-local character. Strengthening the local network in terms of the main agents of the cluster is the most important aspect in order to develop a certain industrial cluster into an innovative cluster. In this respect, if the Zhongguancun Cluster is seen from the perspective of a network, it has a basic network foundation. However, to strengthen international competitiveness, not only the local network but also the international network should be strengthened.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.4
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• pp.642-659
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• 2012

The main aim of this article is to examine theoretical issues on the 'global-local connectivity' of regional industrial cluster and regional innovation system which have been presented since the 2000s in terms of three different aspects. Firstly, the concept of 'geographical proximity' is discussed within the context of its importance for the regional industrial development by considering relationships of cluster, local buzz and global pipeline. Secondly, concepts on knowledge gatekeeper and temporary cluster are explored with respect to their role of a mediator in forming or transforming global-local connectivity. Finally, policy implications of the global-local connection are presented. Authors arguments are as follows; firstly, in order to improve regional industrial cluster on the basis of geographical proximity, relational proximity which is beyond different spatial scales has to be secured. It means that geographical convenience and inconvenience are required simultaneously for regional industrial development. Secondly, A base of the global-local connectivity is socal capital and embeddedness. Therefore, it needs to understand that relational proximity is embedded into different culture and habit at different spatial scales. Finally, within the context of the global-local connectivity, in order to overcome spatial hierarchy by the division of labor of firms, it needs to consider the complex system which is composed of vertical and horizontal hierarchy by the spatial division of labor by firms, openness and closeness of clusters, and the scope of policies' inclusion and exclusion by central and local governments.

• Cartoon and Animation Studies
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• s.12
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• pp.56-72
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• 2007

The purpose of this study is to analyze the characteristics of animation cluster in Chuncheon. It has been over 10 years since Chuncheon was designated as the cluster raising the animation industry. The Chuncheon cluster is trying to differentiate through managing several unique strategies. In order to realize the micro-regionalism, it focuses on co-production not with domestic companies but with foreign companies. Especially, for establishing the whole concrete production pipe-line, it concerns to make co-production contracts dealing with not only for the main production part but also pre- and post-production parts. Based on these production experience, it is building the production complex in the name of ICT convergence cluster. The changed role of the policy-management organization(Gangwon Information & Multimedia Corporation, GIMC) enables these differentiated strategies by itself. The establishment of the Asian Animation Round(AAR) is recognized as the characteristic of macro-regionalism. Starting from the year of 2006, the AAR tries to place Chuncheon as the hub of animation production in Asia and focuses on constructing the network of animation production countries that have developed their production capabilities through sub-contracts. This type of production and market bloc has not been made before.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.291-298
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• 2010

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. The clustering is the one of methods used to manage network energy consumption efficiently and LEACH(Low-Energy Adaptive Clustering Hierarchy) is one of the most famous clustering algorithms. LEACH utilizes randomized rotation of cluster-head to evenly distribute the energy load among the sensor nodes in the network. The random selection method of cluster-head does not guarantee the number of cluster-heads produced in each round to be equal to expected optimal value. And, the cluster head in a high-density cluster has an overload condition. In this paper, we proposed both a token based cluster-head selection algorithm for guarantee the number of cluster-heads and a cluster selection algorithm for uniform-density cluster. Through simulation, it is shown that the proposed algorithm improve the network lifetime about 9.3% better than LEACH.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5B
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• pp.801-808
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• 2010

LEACH, one of hierarchical based routing protocols, was proposed for energy efficiency which is the most important requirement of Wireless Sensor Network(WSN). LEACH protocol is composed of a cluster of certain large number of clusters, which have a cluster head and member nodes. Member nodes send sensing data to their cluster heads, and the cluster heads aggregate the sensing data and transmit it to BS. The challenges of LEACH protocol are that cluster heads are not evenly distributed, and energy consumption to transmit aggregated data from Cluster heads directly to BS is excessive. This study, to improve LEACH protocol, suggests LECEEP that transmit data to contiguity cluster head that is the nearest and not far away BS forming chain between cluster head, and then the nearest cluster head from BS transmit aggregated data finally to BS. According to simulation, LECEEP consumes less energy and retains more number of survival node than LEACH protocol.

• Journal of Technology Innovation
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• v.17 no.1
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• pp.69-95
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• 2009

This paper examines the motives for location decisions of startups and dynamics of cluster growth. Because the location decision is intrinsically strategic choice by entrepreneurs, it is an interplay of three critical forces; cost-benefit of the choice, R&D ability of new entrants, and R&D capability of incumbents in clusters. The effect of knowledge spillovers influences the cluster growth like a double-edge sword; both a positive effect of technology learning and a negative effect of knowledge de-learning. Using data on 710 bio-tech venture firms in Korea, this paper tests the hypotheses about the factors influencing the growth of the cluster. The empirical analyses suggested that early entrepreneurial activity in the clustered regions were important, however other factors such as the organizational legacy, internal dynamics inside a cluster, and the existence of cooperation norm in the cluster, affected long term viability of the cluster.