• 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.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.20-31
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• 2014

Recently, cache sharing methods have been studied in order to effectively reply to user requests in mobile P2P networks. In this paper, we propose a cache sharing scheme based on a cluster considering the peer connectivity in mobile P2P networks. The proposed scheme shares caches by making a cluster that consists of peers preserving the connectivity among them for a long time. The proposed scheme reduces data duplication to efficiently use the cache space in a cluster. The cache space is divided into two parts with a data cache and a temporary cache for a cache space. It is possible to reduce the delay time when the cluster topology is changed or the cache data is replaced utilizing a temporary cache. The proposed scheme checks the caches of peers in a route to a cluster header and the caches of one-hop peers in order to reduce the communication cost. It is shown through performance evaluation that the proposed scheme outperforms the existing schemes.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.425-436
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• 2012

This research aims to investigate the life-style and types of leisure experienced among airline flight attendants during temporary stays abroad. In this study 2 hypotheses based on literature reviews were employed. Questionnaires were also developed based on data collected from previous studies. Subjects of the study were focused on flight attendants in Legacy Airlines. Factor analysis and reliability coefficients were used to examine the internal consistency among variables. Seven dimensions of leisure, which are cultural experience, pursuit of success, social orientation, humanity, pursuit of fashion, shopping preferences and health-orientation were identified from factor analysis. Three dimensions of leisure, which include type of rest, type of sports, and activity of tourists, were identified from factor analysis accordingly. Lifestyle factors were extracted from a result of cluster analysis, cluster 1- Passive lifestyle, Active lifestyle community type 2, and Cluster 3 analyzed Self-satisfied lifestyle types. Airline cabin crew workers involved in the life style analysis can make good use of leisure time.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.3
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• pp.37-45
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• 2004

In this paper we propose Clustered Group Multicast by Clustering Algorithm in Wireless Mobile Ad-hoc Network. The proposed scheme applies to Weighted Cluster Algorithm Ad-hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized administration or reliable support services such as wired network and base station. In ad hoc network muting protocol because of limited bandwidth and high mobility robust, simple and energy consume minimal. WCGM method uses a base structure founded on combination weighted value and applies combination weight value to cluster header keeping data transmission by seeped flooding, which is the advantage of the exiting FGMP method. Because this method has safe and reliable data transmission, it shows the effect to decrease both overhead to preserve transmission structure and overhead for data transmission.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.2
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• pp.361-366
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• 2023

Apache Hadoop, a representative framework for distributed processing of big data, has the advantage of increasing cluster size up to thousands of nodes to improve parallel distributed processing performance. However, reducing the size of the cluster is limited to the extent of permanently decommissioning nodes with defects or degraded performance, so there are limitations to operate multiple nodes flexibly in small clusters. In this paper, we discuss the problems that occur when removing nodes from the Hadoop cluster and propose a dynamic down-scaling technique to manage the distributed cluster more flexibly. To do this, we design and implement a modified Hadoop system and interfaces to support dynamic down-scaling of the cluster which supports temporary pause of a node and reconnection of it when necessary, rather than decommissioning the node when removing a node from the Hadoop cluster. We have verified that effective downsizing can be performed without performance degradation based on experimental results.

• Journal of the Korean Home Economics Association
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• v.28 no.3
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• pp.33-52
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• 1990

The aims of this study are to classify the life styles of urban housewives, to see their relationship between life style and demorgaphic variables, and also to see the relationship between life style and dietary patterns. This study has been performed by a questionsire about life style, demographic variables and dietary pattern. The selected samples were 475 housewives. The data were analyzed by factor analysis, cluster analysis, Duncan test, X-test and F-test. Life style is classified into 4 types: temporary enjoying type, passive irrational type, realistic conservative type, actual progressive type. The housewives who are in temporary enjoying type usually do randomly and don't think seriously something. And they have tendency to enjoy themselves. Therefore they don't have any plan for dietary behavior. The passive irrational type's housewives have no consistancy in their life and they do everything temporarily. The housewives who are in this type have relatively low incom, low level of education and they are high in age. The people who are in realistic conservative type act reasonably and elastically everything. They use convenient food very much, because they are willing to save time to make them. The housewives who are included in actual progressive type are well organized and planned in dietary behavior than others, when they dine out, they eat with family together in general, they usually use only a kind of western sauces and convenient food. They are relatively young, highly educated, and they are high income group. In conclusion realistic conservative type and actual progressive type are both relatively desirable type in dietary behavior, but in temporary enjoying type and passive irrational type, there, have to do some guide and education about managing family resources and dietary behavior.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.2
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• pp.13-20
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• 2005

An ad hoc wireless networks forms temporary network without the aid of fixed networks or centralized administration with a collection of wireless mobile hosts. In this case, it is necessary for one mobile host to enlist the aid of other hosts in forwarding a packet to its destination. This paper presents an efficient cluster-based routing protocol scheme for ad hoc networks. The cluster is used for path setup and data delivery. Our cluster-based routing algorithm is designed for the improvement of the load balance. Our simulation results show the improved performance for low mobility networks comparing with the previous works.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.480-488
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• 2009

A mobile ad-hoc network is an autonomous collection of wireless mobile nodes that organizes a temporary network without any network infrastructure. Due to node mobility, it is a challenging task to maintain the network topology. In this paper, we propose a stable clustering algorithm that uses node mobility for cluster formation. In the proposed algorithm, the node mobility is measured by counting the number of nodes entering into/leaving from its transmission range. The node having the lowest mobility is selected as a cluster head. For topology maintenance with reduced control overhead, the cluster head adaptively controls the broadcasting period of hello message to the measured node mobility. Through computer simulations, it is verified that the proposed algorithm outperforms previous clustering algorithms in terms of control overhead, the rate of node mobility changes and the number of cluster head changes.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.3
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• pp.112-119
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• 2001

This paper proposes an adaptive reclosing scheme which is based on the classification of fault patterns. In case that the first reclosing is unsuccessful in distribution system employing with two-shot reclosing scheme, the proposed method can determine whether the second reclosing will be attempted of not. If the first reclosing is unsuccessful two fault currents can be measured before the second reclosing is attempted, where these two fault currents are utilized for an adaptive reclosing scheme. Total harmonic distortion and RMS are used for extracting the characteristics of two fault currents. And the pattern of two fault currents is respectively classified using a mountain clustering method a minimum-distance classifier. Mountain clustering method searches the cluster centers using the acquired past data. And minimum-distance classifier is used for classifying the measured two currents into one of the searched centers respectively. If two currents have the different pattern it is interpreted as temporary fault. But in case of the same pattern, the occurred fault is interpreted as permanent. The proposed method was tested for the fault data which had been measured in KEPCO's distribution system, and the test results can demonstrate the effectiveness of the adaptive reclosing scheme.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.10-20
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• 2012

This study shows how to estimate AADT(Annual Average Daily Traffic) on temporary count data using new grouping method. This study deals with clustering permanent traffic counts using monthly adjustment factor, daily adjustment factor and a percentage of hourly volume. This study uses a percentage of hourly volume comparing with other studies. Cluster analysis is used and 5 groups is suitable. First, make average of monthly adjustment factor, average of daily adjustment factor, a percentage of hourly volume for each group. Next estimate AADT using 24 hour volume(not holiday) and two adjustment factors. Goodness of fit test is used to find what groups are applicable. MAPE(Mean Absolute Percentage Error) is 8.7% in this method. It is under 1.5% comparing with other method(using adjustment factors in same section). This method is better than other studies because it can apply all temporary counts data.