Load-Induced Cascading Failures In Interconnected Network Systems

Revealing how the interdependency between different networks affects the load-induced cascading failures is a new interesting topic recently. A new cascading failure model for interconnected network system is introduced in this paper, in which the loads of the failed nodes can be transmitted between different layer networks or among each layer network, the ratio is adjusted with a defined parameter T-f which can be viewed as a measure of coupling strength. Based on the proposed model, we find that under different attacking strategies and different value of T-f, different coupling types have different effects on the robustness of interconnected network systems. We mainly focus on the robustness of interconnected network with random coupling under intentional attack, we find there being a threshold T*(f), when T-f < T*(f), the interconnected network systems will be more vulnerable with larger value of T-f ; however, when T-f > T*(f), if the capacity redundancy of interconnected network is low, increasing T-f tends to enhance the robustness of interconnected network system. In addition, we also get the conclusion that increasing the total amount of loads in one layer network or the unbalance of load distribution between different layer networks will decline the robustness of the interconnected network system. We hope our work will shed some light on designing high-robust interconnected network systems or improving the robustness of interconnected network systems.