摘要
As an research example of the widely existing cooperation-competition systems,the authorspresent an empirical investigation on a fruit nutritive factor network.It is described by a node-weightedbipartite graph.The fruit nutritive factors are defined as the nodes,and two nodes are connected by anedge if at least one fruit contains these two nutritive factors.The fruits are defined as the collaborationacts.The node-weight W_(nt),which signifies the 'importance degree' of each actor node,is defined as thecont ent of a nutritive factor in a fruit.The empirical investigation results show some unique features.The node-weight distributions take so-called 'shifted power law' function forms,but the act-weightdistribution takes a normal form.The degree and act-degree distributions show impulsive-spectrumlike forms.These observations may be helpful for the study of fruits.The network description methodproposed in this article may be universal for a kind of cooperation-competition systems.
基金
supported by the National Natural Science Foundation of China under Grant Nos. 10635040 and 70671089