Despite the tremendous effort made by industry and academia,we are still searching for metrics that can characterize Cyberspace and system security risks. In this paper,we study the class of security risks that are in...Despite the tremendous effort made by industry and academia,we are still searching for metrics that can characterize Cyberspace and system security risks. In this paper,we study the class of security risks that are inherent to the dependence structure in software with vulnerabilities and exhibit a "cascading" effect. We present a measurement framework for evaluating these metrics,and report a preliminary case study on evaluating the dependence-induced security risks in the Apache HTTP Server. The experiment results show that our framework can not only clearly analyze the root cause of the security risks but also quantitatively evaluate the attack consequence of the risks.展开更多
In this paper,the fault detection filter(FDF) design problem for networked control systems(NCSs) with both network-induced delay and data dropout is studied.Based on a new NCSs model proposed recently,an observer-base...In this paper,the fault detection filter(FDF) design problem for networked control systems(NCSs) with both network-induced delay and data dropout is studied.Based on a new NCSs model proposed recently,an observer-based filter is introduced to be the residual generator and formulated as an H∞-optimization problem for systems with two successive delay components.By applying Lyapunov-Krasovskii approach,a new sufficient condition on stability and H∞ performance is derived for systems with two successive delay components in the state.A solution of the optimization problem is then presented in terms of linear matrix inequality(LMI) formulation,dependently of time delay.In order to detect the fault,the residual evaluation problem is also considered.An illustrative design example is employed to demonstrate the validity of the proposed approach.展开更多
基金supported by Natural Science Foundation of China under award No.61303024Natural Science Foundation of Jiangsu Province under award No.BK20130372+3 种基金National 973 Program of China under award No.2014CB340600National High Tech 863 Program of China under award No.2015AA016002supported by Natural Science Foundation of China under award No.61272452supported in part by ARO Grant # W911NF-12-1-0286 and NSF Grant #1111925
文摘Despite the tremendous effort made by industry and academia,we are still searching for metrics that can characterize Cyberspace and system security risks. In this paper,we study the class of security risks that are inherent to the dependence structure in software with vulnerabilities and exhibit a "cascading" effect. We present a measurement framework for evaluating these metrics,and report a preliminary case study on evaluating the dependence-induced security risks in the Apache HTTP Server. The experiment results show that our framework can not only clearly analyze the root cause of the security risks but also quantitatively evaluate the attack consequence of the risks.
基金National Natural Science Foundation of China(No.60574081)
文摘In this paper,the fault detection filter(FDF) design problem for networked control systems(NCSs) with both network-induced delay and data dropout is studied.Based on a new NCSs model proposed recently,an observer-based filter is introduced to be the residual generator and formulated as an H∞-optimization problem for systems with two successive delay components.By applying Lyapunov-Krasovskii approach,a new sufficient condition on stability and H∞ performance is derived for systems with two successive delay components in the state.A solution of the optimization problem is then presented in terms of linear matrix inequality(LMI) formulation,dependently of time delay.In order to detect the fault,the residual evaluation problem is also considered.An illustrative design example is employed to demonstrate the validity of the proposed approach.
