This work uses patents as agent and proposes the concept of knowledge adaptation factor in view of the objective law of survival of the fittest in technological evolutionary process. Knowledge genetic decomposition of a patent citation network is executed based on the Mendel law. And the contributions of early patents on current patents along patent citations are quantified to evaluate knowledge adaptability. Then the feasibility and effectiveness of the knowledge adaptability evaluation method are verified with the case study of fuel cell. This study collects 3054 patents related to fuel cell which were granted between 1873 to 2002 from the database of United States Patent and Trademark Office, queries from the patent data set of National Bureau of Economic Research to get 14214 patent citations, and uses the network analysis software Pajek to build the patent citation network. The results of the knowledge adaptability evaluation of fuel cell reflect that the knowledge dissemination process is composed of knowledge inheritance, knowledge innovation and knowledge recombinant. The patents whose knowledge adaptation factors are relatively high are subordinate to the technological evolutionary process of fuel cell. It is consistent with the central idea of knowledge adaptation factor, which is technological-evolution-oriented.
How do new use environments influence a technology's knowledge trajectory? A patent citation network analysis of lithium-ion battery technology
