• Journal of Korean Port Research
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• v.14 no.2
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• pp.143-154
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• 2000

In port management, the scale of facilities and port layouts are major factors characterizing the port, which influence port economics and productivities continuously through the port operation. Grouping ports in certain region by their characteristics could be used as the principal informations to establish national policy for port development or investment and also to analyze the competitiveness between ports. Currently Korean ports are divided into two groups such as the local port and the designated port containing foreign trade port and coastal port under the Korean port law. These divisions seem to be used for port administration as the matter of convenience but some qualitative grouping is needed for research of port problems. In this paper, 20 major Korean ports were clustered by the similar characteristics using Fuzzy C-Means and found to be classified 8 qualitative groups.

• Journal of Magnetics
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• v.10 no.3
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• pp.103-107
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• 2005

Magnetotransport is a prerequisite to realization of electronic operation of spintronic devices and it would be more useful if realized at room temperature. The effects of Be codoping on GaMnAs on magnetotransport were investigated. Mn flux was varied for growth of precipitated GaMnAs layers under a Be flux for degenerate doping via low-temperature molecular beam epitaxy. Magnetotransport as well as ferromagnetism at room temperature were realized in the precipitated GaAs:(Mn,Be) layers. Codoping of Be was shown to promote formation of MnGa clusters, and annealing process further stabilized the cluster phases. The room-temperature magnetic properties of the layers originate from the ferromagnetic clusters of MnGa and MnAs embedded in GaAs. The degenerately doped metallic GaAs matrix allowed the visualization of the magnetotransport through anomalous Hall effect.

• Management & Information Systems Review
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• v.29 no.4
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• pp.169-186
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• 2010

This study aims to reveal the ways to sharpen the edges of Korean companies through the relativity analysis between knowledge management and innovational cluster in environmental changes in resent Busan. That is, according to the knowledge management approach, the methods and directions of strengthening industrial competition were established, while the strategy of innovational clusters was suggested as a way of expanding and encouraging knowledge management. The key words of innovational cluster are in this research are the framework of Cluster theory, the importance of innovational cluster, and the change of managerial strategy paradigm. This study provide the several implication for the practice of knowledge management and the researchers. Based on these theories of knowledge management and industrial clusters, their close relationships were analyzed. As a result, industrial clusters were found to be effectively utilized to enlarge and deepen knowledge management. In addition, this suggests the efficient operation guideline of knowledge management. this study indicates both knowledge and innovational cluster should be operated and handled together in the managerial strategy. but this research has limitations in generaling the study result because it collects data from local firms only in Busan.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.45-51
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• 2006

This paper aims to analysis on evaluation factor for success of port innovative cluster. This paper is divided three factors such ac policy, source and operation In addition, three factors are divided into the twelve detail factors. From a total of 30 survey cases, 50 percent randomly selected as the training group and the other 50 percent as the validation group. cases in the training group were used in the development of the Kohonen Network The validation group was used to test the performance of this model. The major findings may be summarized as follows; The prediction accuracy rate is $73.33\%$ The weight of real root and detail factors is calculated by Kohonen Network At the result, success prediction group of port innovative cluster, this paper places the priority on the source factor.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.33-42
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• 2007

Mobile ad-hoc network(MANET) can increase independence and flexibility of network because it consists of mobile node without the aid of fixed infrastructure. But, Because of unrestriction for the participation and breakaway of node, it has the difficulty in management and stability which is a basic function of network operation. Therefore, to solve those problems, we suggest a distributed weighted clustering algorithm from a manageable and stable point of view. The suggested algorithm uses distributed weighted clustering algorithm when it initially forms the cluster and uses a concept which is distributed gateway and sub-cluster head to reduce the re-clustering to the minimum which occurs mobile nodes after forming the cluster. For performance evaluation, We compare DCA and WCA with the suggested algorithm on the basis of initial overhead, resubscriber rate and a number of cluster.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.219-227
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• 2020

Smart Factory is one of the fastest developing and changing fourth industrial revolution fields. In particular, the degree of introduction and maturity level in the smart factory is an important part. In this paper, a cluster analysis of companies introduced smart factory was performed based on a new maturity assessment model. The 68% of 193 companies surveyed were at the basic level, with only 21% being the middle one. Most SMEs cited lack of funds as the main reason for not entering the middle one. As a result of the cluster analysis, it was found that all clusters had similar patterns but grouped into one of three levels of high, middle, and low depending on maturity level of smart factory operation, and process domain had the highest maturity and data domain was lowest among the 6 domains. Through this, analysis of more specific and quantified maturity levels can be performed using 6-domain smart factory maturity evaluation model.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.9-17
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• 2009

Twenty years have passed since the adoption of natural recreation forests and each forest has its own characteristics. However, there is hardly any classification among the natural recreation forests. The purpose of this study is to classify the forests by considering the supplier's perspective as well as the user's perspective in order to provide fundamental materials for the operation of the natural recreation forests. A factor analysis was conducted to identify the common characteristics of the selected twelve variables by pre-selection and survey of experts. K-means cluster analysis was conducted among those factors to classify the natural recreation forests in Korea. Four factors were drawn after the factor analysis and the factors were named according to the variables and sizes as 'The use performance and visiting condition factor', 'Education and settlement factor', 'Internal activation factor' and 'Potential factor' In addition, the cluster analysis of an $85{\times}4$ matrix was conducted for the points of the drawn factors and the final classification consists of five groups. The results of this study may contribute to providing fundamental materials for the operation and management of natural recreation forests. Also, it may act as a reference when investigating the natural recreation forests of Korea. Proposing the classification natural recreation forests could be helpful in selecting the proper recreation forest in the future. Based on the established model, fundamental materials could be provided to improve the profitability of the natural recreation forests by effectively expanding the number of tourists, creating new natural recreation forests and proper maintenance and management.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.181-194
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• 2020

Due to the changes in the distribution market, issues related to storage and distribution of agricultural, aquatic and livestock products, and storage and transportation of processed and fresh food are rapidly emerging, and as a result, Cold Chain is naturally receiving attention as one of the logistics services. The purpose of this study is to evaluate the competitiveness of location in the construction of a cold chain cluster centered on the metropolitan area, which has attracted attention in relation to the distribution of cold chains, such as recently refrigerated frozen foods. To this end, this study evaluated the competitiveness of cold chain cluster candidates in the metropolitan area by utilizing the CFPR (Consistent Fuzzy Preference Relations) method that can efficiently extract and quantify expert knowledge. As a result, the location competitiveness was found to be superior to Incheon New Port's hinterland, Gyeonggi South Area (Yongin), Gyeonggi West Area (Gimpo Logistics Complex), and Pyeongtaek Oseong Logistics Complex. In particular, this study extracted the knowledge of refrigerated and refrigerated logistics warehouse operation experts, and conducted detailed competitiveness assessments for cold chain cluster candidates in the metropolitan area, and suggested the optimal cluster candidates. In the future research, it is necessary to classify the questionnaire into the owner, large business group, and public business group, etc., who have the right to purchase and build to secure ownership of the fresh food distribution center.

• Journal of Applied Reliability
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• v.6 no.4
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• pp.297-306
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• 2006

In this paper, We presented the algorithm for estimating a reliability between nodes in wireless distributed sensor networks (DSN). To estimate the reliability between nodes, we first modeled DSN as probability graph. Links of the graph are always reliable and the probability of node failure is independent. After all possible simple path which can be established between two nodes are examined, we perform sharp operation to remove repetition event between two nodes. Using probability for each variable of the minimized Boolean equation, we present the reliability formula.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.7
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• pp.928-936
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• 2012

The microgrid concept assumes a cluster of loads and microsources operating as a single controllable system that provides a new paradigm for defining the operation of distributed generation. This system can be operated as both grid-connected mode and islanded mode. In other words, the microgrid can be operated to meet their special need; such as economics in steady state and local reliability in islanded mode due to the grid fault. This paper presents the AGC (Automatic Generation Control) method for microgrid with EMS (Energy Management System).