Cascading Robustness Analysis of Cyber-Physical Systems Considering Inter-Network Degree Correlation

Cyber-Physical Systems (CPSs) represent the integration of information technology and physical systems, gaining increasing significance in society. The Inter-network Degree Correlation (IDC), as a fundamental attribute of CPS, has a significant impact on their performance in cascading failures. However, current research on IDC primarily focuses on limited extreme correlation structures such as maximum positive networks, maximum negative networks, and completely random networks. Little consideration has been given to how IDC affects the cascading robustness of CPS in different interdependency mechanisms. Therefore, this paper constructs a CPS and considers two different interdependencies mechanisms to simulate the varying degrees of dependency found in real-world network systems. By introducing null models, we are able to construct and study interdependent systems with different degrees of IDC. The findings indicate that the impact of IDC on the cascading robustness of CPS is constrained by the interdependency mechanisms. In symmetric interdependency, an increase in IDC can significantly enhance the robustness of CPS. Conversely, in cases of asymmetric interdependence, changes in the interconnectivity between networks have almost no impact on the robustness of CPS. The research underscores the importance of considering the mechanisms of interdependency when assessing the impact of IDC on cascading failures in CPS.