• 한국정보시스템학회지:정보시스템연구
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• 제20권1호
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• pp.147-169
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• 2011

In organizations, evaluating the competency of individuals through the position or status has many limitations. To overcome these limitations, this study analyzes the organization's informal network using social network analysis. We measured out-degree centrality and in-degree centrality by making use of social network analysis technique. Out-degree centrality is interpreted as 'madangbal' in that actors actively help other people, while in-degree centrality is interpreted as 'prestige' in that other people want to have a relationship with. This research examines the effects of individual's 'prestige' and 'madangbal' in the instrumental network and communication network on IT competency. We carried out empirical analysis using social network data that were collected from undergraduate students. The result reveals that relationship between IT competency and centrality in the instrumental network is statistically significant, while relationship between IT competency and centrality in the communication network does not show significant results.

• 농촌계획
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• 제15권1호
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• pp.47-59
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• 2009

The aim of this study is to analyze the green-tourism centrality considering spatial interaction using Gravity Model and social network method. The degree centrality and prestige centrality were applied as green-tourism centrality index. The rural amenity resources and human resources were counted as attraction factors, and a distance among villages was used as friction factor in gravity model. The weights of rural tourism amenity resources were calculated using the analytic hierarchy process(AHP) method and applied to evaluate green-tourism potentiality. The distance was measured with the shortest path among villages using geographic information system(GIS) network analysis. The spatial interaction from gravity model were employed as link weights between nodal points; a pair villages. Using the spatial interaction, the degree-centrality and prestige-centrality indices were calculated by social network analysis and demonstrated possibility of developing integrated green-tourism region centered on high centrality villages.

• 정보관리학회지
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• 제29권2호
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• pp.193-204
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• 2012

이 연구에서는 인용 및 동시인용 문헌 네트워크에서의 중심성 지수를 사용한 추론 통계 적용의 첫 번째 단계로써 이들 간 관계의 선형성을 살펴보고자 하였다. 703개의 문헌 동시인용 네트워크를 활용하여 인용 빈도, 연결정도 중심성, 인접 중심성, 매개 중심성 간의 4가지 주요 관계의 패턴을 살펴본 결과, 모든 인용 및 중심성 간 관계가 선형모델보다는 비선형적 모델로 더 잘 설명될 수 있음을 통계적으로 확인되었다. 따라서 이들 간의 인과관계에 대한 다중회귀분석과 같은 추론 통계 분석의 기반이 되는 선형성을 확보하기 위해서는 논리적인 기준에 근거한 데이터 변환이나 실제값을 구간값으로 변환하는 과정이 필요하다고 할 수 있다.

• 복식
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• 제65권6호
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• pp.25-35
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• 2015

The purpose of this study is to investigate the characteristics of members and communities that have significant influence in the online fashion community through their word-of-mouth activities. In order to identify the influence and the diffusion of word-of-mouth in fashion community, the study selected one online fashion community. Then, the study sorted the online posts and comments made on fashion information and put them into the matrix form to perform social network analysis. The result of the analysis is as follows: First, the fashion community network used in the study has many active members that relay information very quickly. Average time for information diffusion is very short, taking only one or two days in most cases. Second, the influence of word-of-mouth is led by key information produced from only a few members. The number of influential members account for less than 20% of the total number of community members, which indicate high level of degree centrality. The diffusion of word-of-mouth is led by even fewer members, which represent high level of betweenness centrality, compared to the case of degree centrality. Third, component characteristic shares similar information with about 70% of all members being linked to maximize information influence and diffusion. Fourth, a node with high degree centrality and betweenness centrality shares similar interests, presenting strain effect to particular information. Specially, members with high betweenness centrality show similar interests with members of high degree centrality. The members with high betweenness centrality also help expansion of related information by actively commenting on posts. The result of this research emphasizes the necessity of creation and management of network to efficiently convey fashion information by identifying key members with high level of information influence and diffusion to enhance the outcome of online word-of-mouth.

• 인터넷정보학회논문지
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• 제16권5호
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• pp.39-47
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• 2015

그래프에서 각 노드에 대해 그래프 내의 중요도를 나타내는 중심성(centrality)을 계산할 수 있고, 그 값에 따라 각 노드는 중요도 순위(ranking)를 갖는다. 중심성을 나타내는 방법으로는 여러 척도가 있는데, 본 연구에서는 연결도(degree) 중심성, 밀접도(closeness) 중심성, 특성벡터(eigenvector) 중심성, betweenness 중심성에 국한하여 연구를 수행하였다. 본 연구는 그래프에서 에지를 하나 추가할 경우, 그래프 내 노드 전체에 미치는 노드의 중심성 및 순위의 변화를 실험계산을 통해 확인한다. 그리고, 추가되는 에지가 노드 전체의 중심성 및 순위에 미치는 영향은 그래프의 형태에 따라 달라진다는 것을 PCA(Principal Component Analysis)를 통해 밝혔다. 이 사실은 그래프의 구조적 특성을 구분하는 방법으로도 사용될 수 있다.

• 한국철도학회논문집
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• 제20권3호
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• pp.413-422
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• 2017

본 연구에서는 네트워크 중심성 지표를 사용하여 지하철 네트워크의 개별 노드의 중요성을 분석하고 이로부터 한국 지하철 네트워크의 특성을 분석하였다. 중심성 측도로 매개, 근접 그리고 차수 중심성을 사용하였다. 본 연구에서는 기존에 제안된 매개 중심성 지표와 승객들의 실제 흐름양을 함께 고려한 가중 매개 중심성 지표를 새롭게 제안하였다. 그리고 본 연구에서 제안한 여러 중심성 지표들 사이의 상관관계를 조사함으로서 서울 수도권 지하철과 승객 흐름의 구조적 특성 등을 조사하였다. 아울러 승객들 흐름의 편중 현상을 조사하기 위하여 멱분포(Power-law) 분석을 수행하여 결과 분석의 신빙성을 더하였다.

• 정보관리학회지
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• 제31권2호
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• pp.121-142
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• 2014

본 연구는 학술논문의 저자키워드 출현순서에 따른 저자키워드의 중요도를 측정해보고자 하는 연구이다. 먼저 출현순서에 따른 저자키워드의 특징을 분석한 후 네트워크 분석 방법의 연결정도중심성, 근접중심성, 매개중심성, 위세중심성, 그리고 네트워크의 구조적공백성의 효과크기와 같은 지수를 사용하여 학술논문의 저자키워드 출현순서에 따른 저자키워드의 중요도를 측정해보았으며 각각의 네트워크 지수와 저자키워드의 출현순서와의 상관관계분석을 수행하였다. 네트워크 분석 지수 중 연결정도중심성 지수, 매개중심성 지수의 경우 각 학문분야별 저자키워드의 출현순서와의 상관관계의 결과에서의 유의한 분야의 수가 비교적 다른 지수에 비해 많았다. 이와 같은 결과를 통해 저자키워드의 중요도를 단지 출현빈도만으로 판단했던 것에서 벗어나 저자키워드의 중요도 측정을 위한 방법으로 연결정도중심성 지수, 매개중심성 지수도 고려해 볼 수 있음을 알 수 있었다.

• Communications for Statistical Applications and Methods
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• 제29권4호
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• pp.487-498
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• 2022

Social network analysis (SNA) techniques have recently been developed to monitor and detect abnormal behaviors in social networks. As a useful tool for process monitoring, control charts are also useful for network monitoring. In this paper, the degree and closeness centrality measures, in which each has global and local perspectives, respectively, are applied to an exponentially weighted moving average (EWMA) chart and a multinomial cumulative sum (CUSUM) chart for monitoring undirected weighted networks. In general, EWMA charts monitor only one variable in a single chart, whereas multinomial CUSUM charts can monitor a categorical variable, in which several variables are transformed through classification rules, in a single chart. To monitor both degree centrality and closeness centrality simultaneously, we categorize them based on the average of each measure and then apply to the multinomial CUSUM chart. In this case, the global and local attributes of the network can be monitored simultaneously with a single chart. We also evaluate the performance of the proposed procedure through a simulation study.

• Kyungpook Mathematical Journal
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• 제56권4호
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• pp.1191-1205
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• 2016

The emergence of various Internet worms, including the stand-alone Code Red worm that caused a distributed denial of service (DDoS), has prompted many studies on their propagation speed to minimize potential damages. Many studies, however, assume the same probabilities for initially infected nodes to infect each node during their propagation, which do not reflect accurate Internet worm propagation modelling. Thus, this paper analyzes how Internet worm propagation speed varies according to the number of vulnerable hosts directly connected to infected hosts as well as the link costs between infected and vulnerable hosts. A mathematical model based on centrality theory is proposed to analyze and simulate the effects of degree centrality values and closeness centrality values representing the connectivity of nodes in a large-scale network environment on Internet worm propagation speed.

• 보건행정학회지
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• 제29권2호
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• pp.138-145
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• 2019

Background: The purpose of this study is supposed to figure out the keyword network from 2009 to 2018 with social network analysis and provide the research data that can help the Korea government's policy making on smoking cessation. Methods: First, frequency analysis on the keyword was performed. After, in this study, I applied three classic centrality measures (degree centrality, betweenness centrality, and eigenvector centrality) with R 3.5.1. Moreover, I visualized the results as the word cloud and keyword network. Results: As a result of network analysis, 'smoking' and 'smoking cessation' were key words with high frequency, high degree centrality, and betweenness centrality. As a result of looking at trends in keyword, many study had been done on the keyword 'secondhand smoke' and 'adolescent' from 2009 to 2013, and 'cigarette graphic warning' and 'electronic cigarette' from 2014 to 2018. Conclusion: This study contributes to understand trends on smoking cessation study and seek further study with the keyword network analysis.