Exploring technology evolution and transition characteristics of leading countries: A case of fuel cell field

In the course of the technology evolution, the status of leading countries changes with the times. Leading countries may persist, appear, or disappear, i.e. the change of which is named “transitions” which may be effected by some characteristics. An integrated solution is proposed in this study which first identifying technology topics as well as the leading countries over time and then evaluating the relative importance of characteristics and the zero, positive, or negative significant effects of characteristics on different transitions. Analyzing a set of patents related to fuel cell, we found that this technology consisted of several communities in which the segmentation was achieved mainly based on the types of fuel cell. Among those communities, the management utilities were invested mostly, followed by components of polymer electrolyte membrane fuel cell and direct methanol fuel cell, followed by solid oxide fuel cell. The United States and Japan always dominated each sub-domain and Germany and Korea emerged recently. On the other hand, we found that the science linkage (SL), technology cycle time (TCT) and pending duration (PD) were the top three important discriminators for the transitions, whereas the originality index (OI) was the least important one. The stable countries presented increasing manners of the SL, technology dependence (TD), and eigenvector centrality (EC), but a decreasing manner of the TCT. The appearing countries presented increasing manners of the SL and PD, but decreasing manners of the TCT and clustering coefficient (CC). The exiting countries presented an increasing manner of the TCT, but decreasing manners of the SL and degree centrality (DC).