Vulnerability Analysis of Infrastructure Systems Based on Complex Network Theory
|School||Huazhong University of Science and Technology|
|Course||Control Science and Engineering|
|Keywords||Infrastructure systems Complex network Network model Vulnerabilityanalysis Interface design strategy Critical components Infrastructure protection|
Infrastructure systems are the framework of material engineering facilities that provide service for the social production and the resident’s life. It is the general material condition of survival and development for society. It is a topical complex system. Societies today are increasingly dependent on such systems to maintain normal operation. However, events of recent years such as the North American blackout and the Chinese Southern snowstorm have raised alarms in regards to overall safety. In view of the importance of infrastructure systems for social well-being and sustenance, studying response of infrastructure systems under different types of disturbances, analyzing, understanding and identifying vulnerability of infrastructure systems for the purpose of improvement, has become a focal area for the process of optimizing infrastructure design and protection.Utilizing IIM, system dynamics model and agent simulation model, many authoritative agencies and researchers have made an research on the tender inside the infrastructure systems, and discussed the disaster affection to the economic system, functional device and the business processes, etc. But the researchers only get certain preliminary achievements because of the complexity of infrastructure systems. Therefore, the study in vulnerability analysis of infrastructure systems has been at the beginning stage without forming a complete theoretical and methodological system.As abstraction of many real complex systems, complex network theory has been applied to the area of mathematics, life sciences and engineering. It thus provides a new perspective and applied research method to vulnerability analysis of infrastructure systems, allowing a level of analysis that can approach the overall complexity and dynamics of infrastructure systems. Using the theory and method of complex networks, this paper studies the vulnerability of infrastructure systems, starting from a single system and then progressing to interdependent systems. Main contributions of this dissertation are summarized as follows:First, this paper gives the theoretical framework for vulnerability analysis, and analyses the complexity of infrastructure systems. Combined with the theories and methods of complex network, topology description and functional characterizations of infrastructure systems are studied. Meanwhile, to give a more profound understanding of the structural and functional features of the infrastructure systems, parameters such as clustering coefficient, degree, and betweenness are introduced and summarized.Because vulnerability analysis of single infrastructure systems often focuses on node cascading failures and the impact of external factors (such as natural disasters,) edge cascading failures, community structure implementation and community structural vulnerabilities are rarely mentioned. This article establishes a model of edges cascading failures, and analyses the vulnerability of infrastructure systems. Meanwhile, a community detection method and vulnerability metric are proposed to locate the weakest and most robust communities.Interdependent infrastructure system vulnerability analysis is a relatively new area of research. Current research in this area has not yet reached maturation of theory and methodology, especially in the field of modeling. Thus, this paper first studies the infrastructure system from different aspects such as interdependency types, operation states, infrastructure characteristics, failure types, coupling and response behavior, and infrastructure environment. It then establishes a framework for vulnerability analysis.The purpose of vulnerability analysis is to better protect the infrastructure systems. On the basis of vulnerability analysis on single and interdependent infrastructure systems, by considering the performance loss of systems undergoing edge or node failures, key components of an infrastructure system are proposed and identified and network interventions as well as improvement strategies are discussed to better protect the infrastructure systems.