复杂网络牵制控制优化选点算法及节点组重要性排序

本文研究复杂网络动力学模型的无向网络牵制控制的优化选点及节点组重要性排序问题.根据牵制控制的同步准则,网络的牵制控制同步取决于网络的Laplacian删后矩阵的最小特征值.因此,通过合理选择受控节点集得到一个较大的Laplacian删后矩阵最小特征值,是牵制控制优化选点问题的核心所在.基于Laplacian删后矩阵最小特征值的图谱性质,本文提出了多个受控节点选取的递归迭代算法,该算法适用于任意类型的网络.通过BA无标度网络、NW小世界网络及一些实际网络中的仿真实验表明:该算法在控制节点数较少时,能有效找到最优受控节点集.最后讨论了在复杂网络牵制控制背景下节点组重要性排序问题,提出节点组的重要性排序与受控节点的数目有关.

Node-set importance and optimization algorithm of nodes selection in complex networks based on pinning control

Controlling a complex network to achieve a certain desired objective is an important task for various interacting systems.In many practical situations,it is expensive and unrealistic to control all nodes especially in a large-scale complex network.In order to reduce control cost,one turns to control a small part of nodes in the network,which is called pinning control.This research direction has been widely concerned and much representative progress has been achieved so far.However,to achieve an optimal performance,two key questions about the node-selection scheme remain open.One is how many nodes need controlling and the other is which nodes the controllers should be applied to.It has been revealed in our recent work that the effectiveness of node-selection scheme can be evaluated by the smallest eigenvalue λ1 of the grounded Laplacian matrix obtained by deleting the rows and columns corresponding to the pinned nodes from the Laplacian matrix of the network.As a further study of our previous work,we study node selection algorithm for optimizing pinning control in depth,based on the proposed index λ1 and its spectral properties.As is well known,it is an NP-hard problem to obtain the maximum of λ1 by numerical calculations when the number of pinned nodes is given.To solve this challenge problem,in this paper a filtering algorithm is proposed to find most important nodes,which results in an optimal λ1 when the number of pinned nodes is given.The method can be applied to any type of undirected networks.Furthermore,in this paper we propose the concept of node-set importance in complex networks from the perspective of network control,which is different from the existing definitions about node importance of complex networks:The importance of a node set and the selected nodes in this paper depends on the number of pinned nodes;if the number of pinned nodes is different,the selected nodes will be different.The concept of node-set importance reflects the effect of nodes’combination in a network.It is expected that the obtained results are helpful in guiding the optimal control problems in practical networks.