Title Page
ABSTRACT
Contents
LIST OF ABBEREVIATIONS 12
Chapter Ⅰ. INTRODUCTION 13
Ⅰ.1. Advancements in microbiome research 14
Ⅰ.2. Social Network Analysis 16
Ⅰ.3. Purpose of Research 19
Chapter Ⅱ. MATERIALS AND METHODS 23
Ⅱ.1. Data collection 24
Ⅱ.2. Co-Author Networks (CANs) 26
Ⅱ.3. Measures of network 27
Ⅱ.3.1. Average Path Length 27
Ⅱ.3.2. Average Clustering Coefficients 29
Ⅱ.3.3. Modularity 31
Ⅱ.3.4. Betweenness Centrality 34
Ⅱ.4. Topic Modeling 34
Chapter Ⅲ. RESULTS 37
Ⅲ.1. The Growth of microbiome research 38
Ⅲ.2. Comparison of the microbiome field by country 42
Ⅲ.3. Analysis of network topology 45
Ⅲ.4. Visualizations of Co-Author Networks 52
Chapter Ⅳ. DISCUSSION 87
Ⅳ.1. Advancement of research network structure 88
Ⅳ.2. Impact of sequencing technology 90
Ⅳ.3. Diseases and microbiome networks 92
Ⅳ.4. Institutions and microbiome networks 93
Ⅳ.5. Consortia and research funding 94
Ⅳ.6. Two mode networks 95
REFERENCES 97
국문 초록 100
Table Ⅱ.1.1. Search terms for analysis 25
Table Ⅲ.4.1. Time Point of Network Phase 53
Table Ⅳ.2.1. Comparison of device performance for representative sequencing technologies 91
Figure Ⅰ.1. Flow Chart of Network Analysis and Topic Modeling 20
Figure Ⅲ.1.1. Comparison of annual publication numbers by research topic 38
Figure Ⅲ.1.2. Mean number of authors per paper 40
Figure Ⅲ.2.1. Comparison of the number of microbiome papers by country 42
Figure Ⅲ.2.2. Changes in the Number of Research Publication by Country 43
Figure Ⅲ.3.1. Number of nodes of microbiome research Co-Author Networks in various countries 45
Figure Ⅲ.3.2. Average Path Length of microbiome research Co-Author Network in various countries 47
Figure Ⅲ.3.3. Average Clustering Coefficients of microbiome research Co-Author Network in various countries 50
Figure Ⅲ.4.1. Changes in Giant component of microbiome Co-Author Network at each stage 54
Figure Ⅲ.4.2. The microbiome Co-Author Networks in United States Early Phase 55
Figure Ⅲ.4.3. The microbiome Co-Author Networks in United States Mid Phase 56
Figure Ⅲ.4.4. The microbiome Co-Author Networks in United States Late Phase 57
Figure Ⅲ.4.5. The microbiome Co-Author Networks in China Early Phase 59
Figure Ⅲ.4.6. The microbiome Co-Author Networks in China Mid Phase 60
Figure Ⅲ.4.7. The microbiome Co-Author Networks in China Late Phase 61
Figure Ⅲ.4.8. The microbiome Co-Author Networks in Canada Early Phase 62
Figure Ⅲ.4.9. The microbiome Co-Author Networks in Canada Mid Phase 63
Figure Ⅲ.4.10. The microbiome Co-Author Networks in Canada Late Phase 64
Figure Ⅲ.4.11. The microbiome Co-Author Networks in England Early Phase 65
Figure Ⅲ.4.12. The microbiome Co-Author Networks in England Mid Phase 66
Figure Ⅲ.4.13. The microbiome Co-Author Networks in England Late Phase 67
Figure Ⅲ.4.14. The Co-Author Networks in Spain Early Phase 68
Figure Ⅲ.4.15. The microbiome Co-Author Networks in Spain Mid Phase 69
Figure Ⅲ.4.16. The microbiome Co-Author Networks in Spain Late Phase 70
Figure Ⅲ.4.17. The microbiome Co-author networks in France Early Phase 71
Figure Ⅲ.4.18. The microbiome Co-author networks in France Mid Phase 72
Figure Ⅲ.4.19. The microbiome Co-author networks in France Late Phase 73
Figure Ⅲ.4.20. The microbiome Co-Author Networks in Germany Early Phase 74
Figure Ⅲ.4.21. The microbiome Co-Author Networks in Germany Mid Phase 75
Figure Ⅲ.4.22. The microbiome Co-Author Networks in Germany Late Phase 76
Figure Ⅲ.4.23. The microbiome Co-Author Networks in Italia Early Phase 77
Figure Ⅲ.4.24. The microbiome Co-Author Networks in Italia Mid Phase 78
Figure Ⅲ.4.25. The microbiome Co-Author Networks in Italia Late Phase 79
Figure Ⅲ.4.26. The microbiome Co-Author Networks in Japan Early Phase 80
Figure Ⅲ.4.27. The microbiome Co-Author Networks in Japan Mid Phase 81
Figure Ⅲ.4.28. The microbiome Co-Author Networks in Japan Late Phase 82
Figure Ⅲ.4.29. The microbiome Co-Author Networks in Korea Early Phase 83
Figure Ⅲ.4.30. The microbiome Co-Author Networks in Korea Mid Phase 84
Figure Ⅲ.4.31. The microbiome Co-Author Networks in Brazil Early Phase 85
Figure Ⅲ.4.32. The microbiome Co-Author Networks in Brazil Mid Phase 86