Lin Yuan, Zhang Zhongzhi
1] School of Computer Science, Fudan University, Shanghai 200433, China [2] Shanghai Key Lab of Intelligent Information Processing, Fudan University, Shanghai 200433, China.
Sci Rep. 2014 Jun 20;4:5365. doi: 10.1038/srep05365.
We perform an in-depth study for mean first-passage time (MFPT)--a primary quantity for random walks with numerous applications--of maximal-entropy random walks (MERW) performed in complex networks. For MERW in a general network, we derive an explicit expression of MFPT in terms of the eigenvalues and eigenvectors of the adjacency matrix associated with the network. For MERW in uncorrelated networks, we also provide a theoretical formula of MFPT at the mean-field level, based on which we further evaluate the dominant scalings of MFPT to different targets for MERW in uncorrelated scale-free networks, and compare the results with those corresponding to traditional unbiased random walks (TURW). We show that the MFPT to a hub node is much lower for MERW than for TURW. However, when the destination is a node with the least degree or a uniformly chosen node, the MFPT is higher for MERW than for TURW. Since MFPT to a uniformly chosen node measures real efficiency of search in networks, our work provides insight into general searching process in complex networks.
我们对最大熵随机游走(MERW)在复杂网络中进行的平均首次通过时间(MFPT)——随机游走的一个具有众多应用的主要量——进行了深入研究。对于一般网络中的MERW,我们根据与网络相关联的邻接矩阵的特征值和特征向量推导出了MFPT的显式表达式。对于非相关网络中的MERW,我们还在平均场水平上提供了MFPT的理论公式,在此基础上,我们进一步评估了非相关无标度网络中MERW到不同目标的MFPT的主导标度,并将结果与传统无偏随机游走(TURW)的结果进行比较。我们表明,MERW到枢纽节点的MFPT比TURW低得多。然而,当目的地是度数最小的节点或均匀选择的节点时,MERW的MFPT比TURW高。由于到均匀选择的节点的MFPT衡量了网络中搜索的实际效率,我们的工作为复杂网络中的一般搜索过程提供了见解。