Title Page

Contents

Abstract 10

Chapter 1. Introduction 12

Chapter 2. Literature Review 15

Chapter 3. Method 18

3.1. Data Collection 18

3.2. Analysis methodology 19

Chapter 4. Initial statistics 21

4.1. Number of annual publications and contributed venues 21

4.2. Descriptive analysis: Geographical origins, institutional associations and top contributing authors 23

Chapter 5. Network approach 26

5.1. Co-occurence analysis 26

5.2. Three Core fields 30

5.3. Thematic evolution 32

Chapter 6. Direction for future research 36

Chapter 7. Discussion & Conclusion 38

References 41

초록 48

Table 2.1. Summary of previous work 17

Table 4.1. Top 10 publication venues 23

Table 4.2. Top 10 publication institutions 24

Table 4.3. Top 10 publication authors 25

Table 4.4. The number of the corresponding countries (author-based) 25

Table 5.1. Betweenness centrality and Pagerank results in author keyword based network 28

Table 5.2. Betweenness centrality and Pagerank results in abstract-based network 29

Figure 3.1. Representative data collection procedure 20

Figure 4.1. Annual publications 22

Figure 5.1. Co-occurrence network with author keywords 27

Figure 5.2. Co-occurrence network with abstract 29

Figure 5.3. Three field plot using author, keyword and source 31

Figure 5.4. Thematic evolution with author keywords 34

Figure 5.5. Thematic evolution with abstract 35