Research On A Mitigation Strategy For Scale-free Network Against Cascading Failures

With the rapid development of internet technology,complex network applications exist in all aspects of our lives.The most common network model in the real world is the scale-free network.Because of the special mechanism of network evolution,the degree distribution of scale-free network presents power-low distribution characteristic.That is,most nodes have smaller node degrees,and only a small number of nodes have larger node degrees.Once the cascading failure occurs in the network and endangers the nodes with larger nodal degree,the scale-free network will be very fragile and may collapse instantly,which can result in breakdown of the network.Therefore,it is of great practical significance to study the mitigation strategies of the non-scale network intermediate failure problems.In this paper,the specific research contents of cascade failure of scale-free network are as follows:First of all,the main network parameters of the complex network,the evolution model and related characteristics of some classical network models are analyzed and studied.Based on the basic characteristics of complex network,the cascading failure problem of scale-free network is further studied.The steps of cascaded failure behavior in the scale-free network are analyzed,and the vulnerability of the scale-free network to cascade failure is obtained.Second,without changing the network structure,a cascade failure model is established based on the invariable node capacity in the scale-free network.The bearing limit of the network large-scale cascade failure is deduced.Then according to the failure behavior of nodes in descending order of node degree,a mitigation strategy is proposed.The simulation results show that only one mitigation strategy can be adopted for the overloaded nodes with large nodes in the network,which can significantly improve the cascade failure resistance of the scale-free network to such attacks.At the same time,the numerical simulation shows that the total number of nodes and the node capacity are positively correlated with the network cascade failure resistance.Finally,on the basis of the change of network structure,two methods to mitigatecascade failure are proposed.They are the maximum residual capacity increment strategy and the shortest distance enhancement strategy.Combining the two strategies,a load redistribution model is established and theoretical derivation and simulation verification are carried out based on the load capacity model of cascade failure.The results show that the larger the residual capacity,the shorter the edge distance,the more stable the scale-free network.The ability to mitigate cascade failure is obtained under different parameters.Combining the two strategies the optimal parameter values of the scale-free network in the face of cascade failure mitigation are presented.