Research On The Evolution Characteristics Of China's Domestic Patent Cooperation Network

Patent is an important part of the national innovation system.It is not only a bridge between science and production,but also a link connecting knowledge and technology.It can simultaneously characterize knowledge innovation and technological innovation.As an important form of resource sharing and knowledge exchange,patent cooperation can effectively improve the efficiency of individual and overall scientific research.Therefore,the characteristics and laws of patent cooperation are discovered through research on domestic patent cooperation networks,which can provide guidance for the government to formulate policies to promote the development of cooperative innovation,and better promote the construction of an innovative country.Based on the domestic inter-agency patent cooperation data from 1999 to 2018,this article uses the theory and methods of patent measurement analysis and social network analysis to examine the characteristics of the domestic inter-agency patent cooperation network and the characteristics of the domestic inter-agency patent cooperation network subgroups.analysis.First,construct a domestic inter-agency patent cooperation network from 1999 to2018.Analyze the evolution of the scale characteristics,degree distribution characteristics,heterogeneity characteristics and relevance characteristics of the patent cooperation network in the past 20 years.It is found that the gradually expanding domestic inter-agency patent cooperation network has gradually enhanced characteristics of scale-free network and heterogeneous matching.The interaction of these two characteristics of the patent cooperation network makes it increasingly heterogeneous,that is,a small number of nodes play a leading role in the evolution of the patent cooperation network.At the same time,the domestic inter-agency patent cooperation network has a shorter average path length and a higher clustering coefficient,and the network has a higher relevance.Then,according to connectivity,the 20 domestic inter-agency patent cooperation networks were divided into subgroups in turn from 1999 to 2018,and the number characteristics of subgroups and node distribution characteristics of the division results were analyzed.It is found that each year's patent cooperation network consists of a largest subgroup with a large number of nodes and many other subgroups with only a few nodes.In the study of the topological structure characteristics of the largest subgroup and the evolution process of important nodes,it is found that in the process of the gradual expansion of the largest subgroup,the nodes in the subgroup first gradually gather in the form of a star structure.In this process,the subgraph gradually expands in scale.When the subgroup reaches a certain scale,a complex network structure is established between the center nodes of the subgraphs of the star structure.With the further expansion of the scale,the connection between the edge nodes in the star structure subgraph is gradually established,and the complexity of the network structure is further enhanced.In this process,the center of the network has gradually changed from an enterprise to a university.In the study of the topological structure characteristics of other subgroups and the evolution process of important nodes,it is found that in the evolution process of other subgroups,the size of the subgroups will not expand as rapidly as the largest subgroup,only the number of subgroups will increase.In this process,the center of the network is always the enterprise,and enterprise is becoming more and more important in other subgroups except the largest subgroup.