Application of advanced computational techniques to the vulnerability assessment of network systems exposed to uncertain harmful events

Abstract

This paper presents the application of advanced computational techniques developed by the authors for evaluating the vulnerability characteristics of network systems exposed to harmful events. The physical system is modeled as a network (graph) of nodes interconnected by links. Uncertainties on the propagation and effects of an attack are modeled by probability distributions on the times of propagation through the network links and the numbers of people affected at the network nodes reached by the hazard. The impact of an attack is quantified by simulating the propagation of the hazard through the network nodes and links, by means of a combination of cellular automata and Monte Carlo simulation. The vulnerability assessment is embedded within a systematic multiple-objective optimization analysis aimed at identifying the optimal protective scheme which minimizes the average impact in terms of entities affected and hazard propagation time. The vulnerabilities and relative protection schemes of two networks of realistic size are systematically analyzed by the proposed approach for testing the procedure and identifying its strengths and weaknesses. © RAMS Consultants Printed in India.