This method is adopted the Susceptible Infected Removed (SIR) model [34] in which each node includes three compartments, such as susceptible (disposed to be infected), infectious (already infected), and recovered from disease. The authors also accurately calculated outbreak size of the epidemic and the epidemic threshold of the multiplex network. Moreover, they suggested two measures for determining the level of inter-similarity of two layers, such as average similarity of neighbors (ASN) and degree degree correlation (DDC). The ANS is used to evaluate the average of similarity of nodes in different layers while the DDC indicates the correlation of node’s degree in different layers.