• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.47-53
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• 2016

A type of workflow affiliation network is one of the specialized social network types, which represents the associative relation between actors and activities. There are many methods on a workflow affiliation network measuring centralities such as degree centrality, closeness centrality, betweenness centrality, eigenvector centrality. In particular, we are interested in the closeness centrality measurements on a workflow affiliation network discovered from enterprise workflow models, and we know that the time complexity problem is raised according to increasing the size of the workflow affiliation network. This paper proposes an estimated ranking algorithm and analyzes the accuracy and average computation time of the proposed algorithm. As a result, we show that the accuracy improves 47.5%, 29.44% in the sizes of network and the rates of samples, respectively. Also the estimated ranking algorithm's average computation time improves more than 82.40%, comparison with the original algorithm, when the network size is 2400, sampling rate is 30%.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.413-422
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• 2017

In this study we investigate the importance of the subway station using network centrality measures. For centrality measures, we have used betweenness centrality, closeness centrality, and degree centrality. A new measure called weighted betweenness centrality is proposed, that combines both traditional betweenness centrality and passenger flow between stations. Through correlation analysis and power-law analysis of passenger flow on the Seoul metropolitan subway network, we have shown that weighted betweenness centrality is a meaningful and practical measure. We have also shown that passenger flow between any two stations follows a highly skewed power-law distribution.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.146-148
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• 2013

본 연구는 지속가능한 물류활동에서 관심을 받고 있는 내항해운(연안해운)의 물류네트워크를 파악하기위한 기초분석으로서 연안여객항로에 관하여 네트워크를 파악하였다. 최근에 기존의 계량적 통계분석방법을 뛰어넘어 존재하고 있는 구조와 실체를 파악하기위해 사회연결망분석이 도입되고 있는 상황에서, 우리나라 연안해운항로의 네트워크를 파악하고자 하였다. 내항해운은 화물운송과 여객운송으로 구별되나 본 연구에서는 화물선만 고려하였다. 국가물류통합정보센터와 해운항만물류정보시스템을 활용하여 한국의 내항해운의 중심성을 분석하였다. 중심성 분석을 위해서 화물선 출입항 척수와 화물처리량을 변수로 사용하여 Pajek과 UCINET 등의 SNA 프로그램을 이용한 결과 내항해운 네트워크를 도식화하고 파악하였다. 결과적으로 네트워크의 node에 해당하는 항만 중에서 어떤 항만이 가장 중요한 노드인지를 찾고, 네트워크 구조가 얼마나 소수의 중요한 항만에게 집중되는 것인지를 확인하기 위하여 중심성 분석을 통해 파악하였다.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.607-614
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• 2014

This article aims to explore and discuss research trends in global cruise industry using keyword network analysis. We visualize keyword networks in each of four groups of 1982-1999, 2000-2004, 2005-2009, 2010-2014 based on the top 20 keyword nodes' degree centrality and betweenness centrality which are selected among four centrality measurements, comparing them with frequency order. The article shows that keyword frequency collected from 240 articles published in international journals is subject to Zipf's law and nodes degree distribution also exhibits power law. We try to find out research trends in global cruise industry to change some important keywords diachronically, visualizing several networks focusing on the top two keywords, cruise and tourism, belonging to all the four year groups, with high degree and betweenness centrality values. Interestingly enough, a new node, China, connecting the top most keywords, appears in the most recent period of 2010-2014 when China has emerged as one of the rapid development countries in global cruise industry. Therefore keyword network analysis used in this article will be useful to understand research trends in global cruise industry because of increase and decrease of numbers of network types in different year groups and the visual connection between important nodes in giant components.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.151-153
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• 2014

본 논문에서는 사회네트워크 분석 기법을 이용하여 2005년부터 2013년까지 운용되었던 국내 연안여객선의 항로를 분석하였다. 분석결과 연도별로 중심이 되는 항구가 변화되는 것을 확인할 수 있었다. 목포는 지속적으로 가장 높은 연결 중심성을 보였으며, 여수는 최근 그 중심성이 높아지는 것을 확인하였다. 또한 물동량과 이용량 등 전통적인 방법을 통하여 분석한 결과와 사회 네트워크 방법으로 분석한 결과 값을 비교하였는데 이 두 값이 매우 강한 상관관계를 보였다. 이를 통해 전통적인 방법을 사용하지 않더라도 네트워크 분석을 통해 해당 항구의 중심성을 알 수 있음을 확인하였다.

• Journal of Korean Library and Information Science Society
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• v.50 no.4
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• pp.77-100
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• 2019

This study aims to analyze and compare centrality and brokerage measures of journal citation network focusing on textmining research. The analytic sample was 193 academic articles collected from 136 KCI journals published in 2018. The journal citation network was constructed based on citation relations. The characteristics, centralities, and brokerages of network was analyzed. The journal citation network consisted 136 nodes and 413 links with directed and weight. According to the five types of centrality(out-degree, in-degree, out-closeness, in-closeness, betweenness), journals of social sciences, engineering, and interdisciplinary research showed higher centrality. Social sciences, engineering and interdisciplinary research journals also showed higher brokerages as a result of brokerage analysis which identify five types of brokerage roles(coordinator, gatekeeper, representative, consultant, liaison). The centralities and brokerages of journals are positively correlated. This study suggested how to construct journal citation network from the articles focusing on certain topics. This was meaningful study in terms of conducting brokerage analysis and comparing it with centrality in the journal citation network.

• Proceedings of the Korean Society for Information Management Conference
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• 2013.08a
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• pp.27-30
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• 2013

공동연구 네트워크의 대표적인 사례인 공저 네트워크는 오랫동안 네트워크 분석의 대상으로 다루어져 왔다. 최근에는 가중 네트워크로서 공저 네트워크에 대한 연구가 활발해지면서 연구자의 영향력을 측정하려는 몇 가지 척도가 제안되었다. 이 연구에서는 공저 네트워크에서의 중심성을 측정하기 위해서 사용된 척도인 가중페이지랭크, 공동연구 h-지수와 공동연구 hs-지수, 복합연결정도중심성, c-지수에 대해서 비교 분석해본다.

• Journal of the Korean Society for information Management
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• v.25 no.4
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• pp.327-345
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• 2008

The main purposes of this study are to construct a Korean science network from journal contributions data of Korean researchers, and to analyze the structure and characteristics of the network. First of all, the association matrix of 140 scholarly domains are calculated based on the number of contributions in common journals, and then the Pathfinder network algorithm is applied to those matrix. The resulting network has several hubs such as 'Biology', 'Korean Language & Linguistics', 'Physics', etc. The entropy formula and several centrality measures for the weighted networks are adopted to identify the centralities and interdisciplinarity of each scholarly domain. In particular, the date hubs, which have several weak links, are successively distinguished by local and global triangle betweenness centrality measures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.295-301
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• 2018

In various disciplines, researchers, not single researchers, tend to cooperate to study the same topic. There are many studies to analyze the collaborative form of various researchers through the social network analysis method, but there are few such studies in the computer field. In this paper, we analyze the characteristics of network and various groups of researchers through the social network analysis technique of the co-authors of the Journal of Korea Institute of Information and Communication Engineering, and analyze the degree centrality, the between centrality and edge weight. As a result of the analysis, many groups were extracted from the co-author's network, but the top 20 groups accounted for more than 50% of the total, also, we could find a pair of researchers who do joint research with a very high frequency. These Co-author networks are expected to be the basis for in-depth research on the subject and direction of research through future researches.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.189-207
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• 2015

The purpose of this study is to examine the relationship between the network characteristics of ports and their performance that is represented by port competitiveness for the port operators. The study employs Social Network Analysis (SNA) to evaluate network characteristics comprising four centrality indices. For this research, data from Containerization International Yearbooks for 2006-2011 is used to analyze the service networks of 20 major liner shipping companies. In SNA, nodes (vertices) in the network are the ports and links (edges) in the network are connections realized by vessel movements, such that the liner shipping network determines the port network. In addition, panel regression analysis has been employed to investigate the relationship between port network characteristics and their performance. The results suggest that the four centrality indices identify the roles of the world's major ports from 2006 to 2011 and that port performance is determined not only by macroeconomic variables and service capabilities but also by the eigenvector centrality of ports in networks.