• Title/Summary/Keyword: 중심도

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An Estimated Closeness Centrality Ranking Algorithm for Large-Scale Workflow Affiliation Networks (대규모 워크플로우 소속성 네트워크를 위한 근접 중심도 랭킹 알고리즘)

  • Lee, Do-kyong;Ahn, Hyun;Kim, Kwang-hoon Pio
    • 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%.

교구를 활용한 여러 대상의 무게중심 실험

  • Jang, Hun
    • Proceedings of the Korea Society of Mathematical Education Conference
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    • 2010.04a
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    • pp.225-225
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    • 2010
  • 몇 가지 교구를 사용하여 여러 대상의 무게중심을 찾아보고 수학적으로 정리한다. (1) 피노키오의 늘어나는 코 실험: 막대를 가장 길게 쌓는 방법 (2) 점 무게중심 실험: 일렬로 매단 추들의 무게중심, 삼각형, 사각형의 꼭짓점에 매단 추들에 대한 무게중심 (3) 선 무게중심 실험 : 삼각형, 사각형의 변에 대한 무게중심 (4) 면무게중심 실험 : 삼각형, 사각형, 오각형의 면의 무게중심

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Correlation Between Social Network Centrality and College Students' Performance in Blended Learning Environment (블렌디드 러닝 환경에서 사회 연결망 중심도와 학습자 성과 간의 상관관계)

  • Jo, II-Hyun
    • The Journal of Korean Association of Computer Education
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    • v.10 no.2
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    • pp.77-87
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    • 2007
  • The purpose of the study was to investigate the effects of social network centrality variables on students' performance in blended learning environment in a higher educational institution. Using data from 36-student course on Learning Theories and Their Implications on Instructional Design Practices, the researcher empirically tested how social network centrality variables - such as friendship network centrality, advice network centrality, and adversary network centrality - are correlated with academic achievement measures. Results indicate, as hypothesized, the friendship and advice centrality positively correlate with, whereas the adversary centrality being negatively correlate with application performance measures and test scores. The size and quality of posted online discussions are positively and strongly correlated with the advice network centrality.

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Performance Analysis of an Estimated Closeness Centrality Ranking Algorithm in Large-Scale Workflow-supported Social Networks (대규모 워크플로우 소셜 네트워크의 추정 근접 중심도 랭킹 알고리즘 성능 분석)

  • Kim, Jawon;Ahn, Hyun;Kim, Kwanghoon
    • Journal of Internet Computing and Services
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    • v.16 no.3
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    • pp.71-77
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    • 2015
  • This paper implements an estimated closeness centrality ranking algorithm in large-scale workflow-supported social networks and performance analyzes of the algorithm. Existing algorithm has a time complexity problem which is increasing performance time by network size. This problem also causes ranking process in large-scale workflow-supported social networks. To solve such problems, this paper conducts comparison analysis on the existing algorithm and estimated results by applying estimated-driven RankCCWSSN(Rank Closeness Centrality Workflow-supported Social Network). The RankCCWSSN algorithm proved its time-efficiency in a procedure about 50% decrease.

An Efficient Algorithm for Betweenness Centrality Estimation in Social Networks (사회관계망에서 매개 중심도 추정을 위한 효율적인 알고리즘)

  • Shin, Soo-Jin;Kim, Yong-Hwan;Kim, Chan-Myung;Han, Youn-Hee
    • KIPS Transactions on Software and Data Engineering
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    • v.4 no.1
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    • pp.37-44
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    • 2015
  • In traditional social network analysis, the betweenness centrality measure has been heavily used to identify the relative importance of nodes. Since the time complexity to calculate the betweenness centrality is very high, however, it is difficult to get it of each node in large-scale social network where there are so many nodes and edges. In our past study, we defined a new type of network, called the expanded ego network, which is built only with each node's local information, i.e., neighbor information of the node's neighbor nodes, and also defined a new measure, called the expanded ego betweenness centrality. In this paper, We propose algorithm that quickly computes expanded ego betweenness centrality by exploiting structural properties of expanded ego network. Through the experiment with virtual network used Barab$\acute{a}$si-Albert network model to represent the generic social network and facebook network to represent actual social network, We show that the node's importance rank based on the expanded ego betweenness centrality has high similarity with that the node's importance rank based on the existing betweenness centrality. We also show that the proposed algorithm computes the expanded ego betweenness centrality quickly than existing algorithm.

The factors influencing the quantity of Phoria: I. A study of effects to the quantity of Phoria by the refractive error and the conformity to the optical center and the pupillary center (사위량에 영향을 미치는 요인: I. 굴절이상, 동공중심과 광학중심의 일치에 따른 연구)

  • Kim, Jung-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.361-370
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    • 2004
  • The purpose of this study was to evaluate the outcome and Factors that influence the quantity of Phoria in the low correction and perfect correction. Also the coincidence with the opticenter and the pupillary distance was a principal factor that influence the quantity of Phoria. Thereupon, this study is attributed to promote the perfect Phoria test. The subjects for this study were 120 persons(240 eye) in myopic refractive errors. ISP/WIN program was used for the data analysis. The collected data was analyzed by descriptive statistics and Spearman's correlation coefficient. The results of this study were as follows: 1. The prism pattern was difference between low correction and perfect correction in the Phoria test. The proportion of orthophoria was changed from 10.0% to 12.5%, exophoria was changed from 67.5% to 62.5%, and esophoria was changed from 22.0% to 32.5%, respectively. 2. The average of optical center distance and pupillary distance were 31.70mm and 31.49 mm, respectively. 3. Among the 120 myopic glasses wearers, the distance between optical centers was coincided with the pupillary distance in 37.5%, and discrepant in 62.5%. 4. For the patients who were coincided with the pupillary distance, the proportion of exophoria decreased 53.33%, esophoria increased 20.0%. 5. For the changing of the quantity of Phoria in the low correction, the degree of exophoria decreased 1.11 prism diopters in the perfect correction, esophoria increased 0.39 prism diopters.

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Curriculum Orientations of Home Economics Teacher Educators (가정과 교사교육자들의 가정과 교육과정 관점)

  • Ryu, Sang-Hee
    • Korean Journal of Human Ecology
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    • v.10 no.1
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    • pp.1-13
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    • 2001
  • 본 연구는 가정과 교사교육자(전국 국 사립 대학의 가정교육과에 재직하고 있는 교수)들의 교육과정 관점을 조사함으로써 실천적 비판 중심 가정과 교육과정 개발을 위한 기초자료와 교사교육자들을 위한 세미나 프로그램 개발을 위한 유용한 자료를 제공하고자 한다. 본 연구의 결과는 다음과 같다. (1) 가정과 교사교육자들은 하나의 두드러진 교육과정 관점을 선호하지는 않았지만 인지과정중심 교육과정에 가장 높은 선호도를 보였다. (2) 석사과정에서 가정학 세부영역을 전공한 교사교육자는 가정교육학을 전공한 교사교육자보다 학문중심 교육과정과 기술중심 교육과정을 가정과 교육을 위한 적절한 관점으로 인식하였다. (3) 박사과정에서 가정교육학을 전공한 교사교육자는 가정학 세부영역을 전공한 교사교육자보다 개인중심교육과정을 가정과 교육을 위한 적절한 관점으로 인식하였다. (4) 가정교육학 관련 교과목을 가르치는 교사교육자는 가정학 세부영역 관련 교과목을 가르치는 교사교육자보다 기술중심 교육과정을 가정과 교육을 위한 적절한 관점으로 인식하였다.

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Local Information-based Betweenness Centrality to Identify Important Nodes in Social Networks (사회관계망에서 중요 노드 식별을 위한 지역정보 기반 매개 중심도)

  • Shon, Jin Gon;Kim, Yong-Hwan;Han, Youn-Hee
    • KIPS Transactions on Computer and Communication Systems
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    • v.2 no.5
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    • pp.209-216
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    • 2013
  • In traditional social network analysis, the betweenness centrality measure has been heavily used to identify the relative importance of nodes in terms of message delivery. Since the time complexity to calculate the betweenness centrality is very high, however, it is difficult to get it of each node in large-scale social network where there are so many nodes and edges. In this paper, we define a new type of network, called the expanded ego network, which is built only with each node's local information, i.e., neighbor information of the node's neighbor nodes, and also define a new measure, called the expended ego betweenness centrality. Through the intensive experiment with Barab$\acute{a}$si-Albert network model to generate the scale-free networks which most social networks have as their embedded feature, we also show that the nodes' importance rank based on the expanded ego betweenness centrality has high similarity with that based on the traditional betweenness centrality.

일본의 중심상점가 활성화

  • Im, Jun-Hong
    • 열린충남
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    • s.33
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    • pp.182-189
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    • 2006
  • 중심시가지의 노후와와 교외개발의 메카니즘 속에서 일본의 중심시가지는 침체와 쇠퇴를 거듭하고 있으며, 이를 극복하기 위해 1998년부터 "중심 시가지에 대한 시가지 정비 개선 및 상업 등의 활성화의 일체적 주진에 관한 법률"에 근거하여 연간 1조엔의 예산을 편성하고 경제산업성등 관련 부처들과 TMO(Town Management Organization) 차원에서 총체적인 접근을 하고 있다. 이러한 중심상점가의 쇠퇴는 우리나라에서도 정도의 차이는 있지만 유사한 형태로 나타나고 있다. 이에 일본의 중심상점가를 살펴봄으로써 우리나라 주심상점가의 활성화 방향을 모색하는데 도움을 주고자 한다.

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ANP와 DEA 결합모형을 통한 은행의 성과 평가방법론에 관한 연구

  • 임병학;박철수
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.940-947
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    • 2003
  • 은행의 지점을 하나의 책임중심점 (Responsibility center)으로 볼 때 원가중심점. 수익중심점, 이익중심점 및 투자중심점 등 네 가지 형태중의 하나로 구분 할 수 있다. 본 연구에서는 은행의 지점을 여러가지 투입물을 이용하여 여러가지의 다양한 산출물들을 생산 및 판매하는 이익중심점(Profit Center)으로 보기로 한다. 그리고 이익중심점으로서 은행의 지점을 평가하는 경우 기간이익이라는 종합적인 성과 측정치가 있으나 기간이익은 그 성과가 경쟁가격의 변화에 따른 것인지 업무의 효율에 의만 것인지 구별하기가 어렵다 그래서 본 연구에서는 장기적인 효과를 가지는 생산성. 즉 생산과정에 중점을 두고 평가하고자 한다.

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