Technology Trend Analysis of Japanese Green Vehicle Powertrains Technology Using Patent Citation Data

As automobiles are major contributors to greenhouse gas emissions, the technological shift towards vehicle powertrain systems is an attempt lower problems such as emissions of carbon dioxide and nitrogen oxides. Patent data most reliable measure business performance for applied research development activities when investigating knowledge domains or technology evolution. This first study on Japanese patent citation green powertrains industry, using social network analysis method, which emphasizes centrality estimates community detection. not only elucidates by visualizing flow patterns but also provides a precious congregative method verifying important patents under International Classification system grasping trend new industry. detects leading companies, in terms number importance patents. The empirical result shows that (IPC) class starts with “B60K”, includes hybrid electric (HEV) battery (BEV), more likely be