Abstract: Recent disasters，such as earthquakes, typhoons, and terrorist attacks, disrupted operations of critical infrastructure systems and even destroyed functions of our society. Therefore, it is necessary and important to maintain critical infrastructure systems which are not only cost-effective but also able to respond quickly, handle smoothly, and recover promptly from disruptions. To achieve this goal, a linear piece-wise recovery function is proposed based on three other recovery functions and then develops a resilience analysis model. The proposed model is applied to the decision-making processes of improving the resilience of the power system in C county. C county is a coastal area vulnerable to hurricanes and its power network consists of 958 arcs and 939 nodes, including 4 supply nodes and 56 transfer nodes. In addition, to estimate the probability of nodes being disrupted and identify the critical nodes that require priority protection, different disaster scenarios are simulated according to the type, severity, and extent of the disaster in C county. The results show that: (1) this linear piece-wise recovery function enables tradeoff between a cost minimum system and a resilient system; (2) this resilience analysis model can distinguish the critical nodes in infrastructure systems and give the best and highly individualized approach to protect critical infrastructure systems. Overall, a new analysis model is developed for the protection of the critical infrastructure systems and therefore the targeted strategies and suggestions can be provided to protect the critical infrastructure systems.

Key words: network resilience; critical infrastructure systems; network flow optimization; emergency management; mathematic programming