• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.55-71
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• 2017

This paper points out the semantic unclearness of the jargon "cluster" and suggests the substitution of "industrial cluster" for "cluster". Industrial cluster is the intersection of industrial agglomeration and cluster phenomenon while the actual concept of cluster includes not only industry cluster but also political administration cluster, science research cluster, art cluster, religion cluster, education cluster, etc. Partially reconstructing the concept and significance of industry cluster, industrial cluster is a geographic agglomeration of interconnected productional businesses in a particular industry, forming close industrial networks. The advantage of the agglomeration includes reducing the transaction cost between the businesses, promoting technological innovation and dispersion, facilitating the utilization of the professional workforce, sharing and connecting the external customer. Moreover, this paper discusses the range of the industrial cluster and its distinctness from the other similar concepts. There is a need to discriminate it from the other related jargons and to clarify their relationship. In particular, there is a task to eradicate the mixed usage of industrial cluster with the jargons related to space for learning and innovation.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.3
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• pp.79-99
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• 2020

The purpose of this study is to investigate the model of cluster analysis techniques for grouping public libraries and analyze their characteristics. Statistical data of public libraries of the National Library Statistics System were used, and three models of cluster analysis were applied. As a result of the study, cluster analysis was conducted based on the size of public libraries, and it was largely divided into two clusters. The size of the cluster was largely skewed to one side. For grouping based on size, the ward method of hierarchical cluster analysis and the k-means cluster analysis model were suitable. Three suggestions were presented as implications of the grouping method of public libraries. First, it is necessary to collect library service-related data in addition to statistical data. Second, an analysis model suitable for the data set to be analyzed must be applied. Third, it is necessary to study the possibility of using cluster analysis techniques in various fields other than library grouping.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.688-701
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• 2014

This article is focused on the agglomeration and decline factors of the footwear industries in Busan metropolitan area from the industrial cluster point of perspective. For the research, 'the components and network of industrial cluster model' are presented which is restructured of M. Porter's cluster model. Moreover, this research have examined the agglomeration and decline process of the footwear industries in Busan area and conducted a survey targeting footwear enterprises in Busan area. In the late 1980's, the footwear industries in Busan area formed the largest footwear industrial cluster in the world. However, the industrial cluster started to decline from early 1990's and now it is reduced in to 1/10 size of the past. The growth factors of Busan footwear industrial cluster include cheap and plentiful labours, penetration of OEM production, entrepreneur spirit, human resources network, government's support and so on. Moreover, the agglomeration of relative companies also created high competitiveness in this cluster. The decay factors are pointed out sudden rise of labour cost, shortage of factory site, rise of land price, alteration of government policy, international relocation of footwear production and growth of overseas industrial cluster. Busan footwear industrial cluster nowadays has declined in its size, but it is the only footwear industrial cluster in Korea.

• Korea Journal of Hospital Management
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• v.28 no.2
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• pp.9-20
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• 2023

Purpose: This study classified the actual functions of geriatric hospitals and examined the differences in their characteristics, in order to provide a basis for discussions on defining the functions of geriatric hospitals and how to pay for care. Methodology: This study used various administrative data such as health insurance data and long-term care insurance data. Cluster analysis was used to categorize geriatric hospitals. To examine the validity of the cluster analysis results, we conducted a discriminant analysis to calculate the accuracy of the classification. To examine cluster characteristics, we examined structure, process, and outcome indicators for each cluster. Findings: The cluster analysis identified five clusters. They were geriatric hospitals with relatively short stays for cancer patients(cluster 1; cancer patient-centered), geriatric hospitals with relatively large numbers of patients using rehabilitation services(cluster 2; rehabilitation patient-centered), geriatric hospitals with a high proportion of relatively severe elderly patients(cluster 3; severe elderly patient-centered), geriatric hospitals with a high proportion of mildly ill elderly patients with various conditions(cluster 4; mildly ill elderly patient-centered), and geriatric hospitals with a significantly higher proportion of dementia patients(cluster 5; dementia patient-centered). The largest number of geriatric hospitals were categorized in clusters 4 and 5, and the structure and process indicators for these clusters were generally lower than for the other clusters. Practical Implications: We have confirmed the existence of geriatric hospitals where the medical function, which is the original purpose of a geriatric hospital, has been weakened. It has been observed that the quality level of these geriatric hospitals is likely to be lower compared to hospitals that prioritize enhanced medical functions. Therefore, it is suggested to consider the conversion of these geriatric hospitals into long-term care facilities, and careful consideration should be given to the review of care-giver payment coverage.

• Journal of Korea Multimedia Society
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• v.19 no.5
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• pp.910-917
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• 2016

Sensors have limited resources in sensor networks, so efficient use of energy is important. Representative clustering methods, LEACH, LEACHC, TEEN generally use direct transmission methods from cluster headers to the sink node to pass collected data. However, the communication distance of the sensor nodes at low cost and at low power is not long, it requires a data transfer through the multi-hop to transmit data to the sink node. In the existing cluster-based sensor network studies, cluster process and route selection process are performed separately in order to configure the routing path to the sink node. In this paper, in order to use the energy of the sensor nodes that have limited resources efficiently, a cluster-based multi-hop routing protocol which merges the clustering process and routing process is proposed. And the proposed method complements the problem of uneven cluster creation that may occur in probabilistic cluster methods and increases the energy efficiency of whole sensor nodes.

• Journal of the Korean Statistical Society
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• v.28 no.2
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• pp.235-251
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• 1999

In this paper we examine extremal behavior of a $textsc{k}$th-order stationary Markov chain {X\ulcorner} by considering excesses over a high level which typically appear in clusters. Excesses over a high level within a cluster define a cluster damage, i.e., a normalized sum of all excesses within a cluster, and all excesses define a damage point process. Under some distributional assumptions for {X\ulcorner}, we prove convergence in distribution of the cluster damage and obtain a representation for the limiting cluster damage distribution which is well suited for simulation. We also derive formulas for the mean and the variance of the limiting cluster damage distribution. These results guarantee a compound Poisson limit for the damage point process, provided that it is strongly mixing.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.58.2-58.2
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• 2014

The Arches cluster is a young (2-4 Myr), compact (~1 pc), and massive (${\sim}2{\times}10^4M_{\odot}$) star cluster located ~30 pc away from the Galactic center (GC) in projection. Being exposed to the extreme environment of the GC such as elevated temperature and turbulent velocities in the molecular clouds, strong magnetic fields, and larger tidal forces, the Arches cluster is an excellent target for understanding the effects of star-forming environment on the initial mass function (IMF) of the star cluster. However, resolving stars fainter than ~1 $M_{\odot}$ in the Arches cluster partially will have to wait until an extremely large telescope with adaptive optics in the infrared is available. Here we devise a new method to estimate the shape of the low-end mass function where the individual stars are not resolved, and apply it to the Arches cluster. This method involves histograms of pixel intensities in the observed images. We find that the initial mass function of the Arches cluster should not be too different from that for the Galactic disk such as the Kroupa IMF.

• Journal of information and communication convergence engineering
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• v.22 no.1
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• pp.1-6
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• 2024

Energy efficiency in wireless sensor networks (WSNs) is a critical issue because batteries are used for operation and communication. In terms of scalability, energy efficiency, data integration, and resilience, WSN-cluster-based routing algorithms often outperform routing algorithms without clustering. Low-energy adaptive clustering hierarchy (LEACH) is a cluster-based routing protocol with a high transmission efficiency to the base station. In this paper, we propose an energy consumption model for LEACH and compare it with the existing LEACH, advanced LEACH (ALEACH), and power-efficient gathering in sensor information systems (PEGASIS) algorithms in terms of network lifetime. The energy consumption model comprises energy-sensitive cluster formation and a cluster head selection technique. The setup and steady-state phases of the proposed model are discussed based on the cluster head selection. The simulation results demonstrated that a low-energy-consumption network was introduced, modeled, and validated for LEACH.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.113-119
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• 2000

A Robotic milking cluster system with the manipulator for an automatic milking system was designed and built for farmer to work easily and comfortably during milking processing. The cluster system was composed of screws, cams and links for power transmission, DC motors, the Quick Basic one-chip microprocessor, the vision system for image processing, and tea-cups. Software, written in Visual C+ and Quick Basic, combined the function of image capture, image processing, milking cluster control, and control into one control. The unit was made to transfer from four fixed points to four teats with four teat-cups. Performance tests of the cluster unit, the fully integrated system, were conducted to attach and detach the teat-cup on the teat of a artificial cow. The transfer programming provided for a teat-cup milking loop during the system starts and comes back the original fixed point at the manipulator of it for milking. It transferred the teat-cup with a success rate of more than 70%. The average time it took ot perform the milking loop was about 20 seconds.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.309-315
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• 2016

The node mobility in the wireless mobile network environment increases the energy consumption. This paper proposes a CNMA (cluster-based node management algorithm) to reduce the energy consumption caused by node mobility, and to prolong the life cycle for cluster member nodes. The proposed CNMA traces the mobility for nodes between cluster header and member, and it analyses the energy capacity as monitoring periodically their relationship. So, it makes a division and merges by analysing the state transition for nodes. This paper is to reduce the energy consumption due to the node mobility. The simulation results show that the proposed CNMA can efficiently control the energy consumption caused by mobility, and it can improve the energy cycle.