3.5. Keyword and theme trend analysis
Appeared
Analysis of keywords can help identify the research hotspots in the field, understand the evolution of topics, and predict future trends. It also provides a useful tool for a comprehensive analysis of collected articles. To identify the frequency, evolution, emergence, and concepts of keywords, keyword analysis was conducted in this paper. Briefly, as shown in Figure (A) Author keyword word frequency analysis. (B) Extended keyword word frequency analysis. (C) Appeared in the frequency of the top 10 extended keywords.The extended keywords were analyzed in Figure Figure Frequency of keyword occurrences as a percentage of overall.The keyword clusters are shown in Figure (A) Keyword cluster analysis. (B) Theme trend keyword.Figure 