Chunyan Wang

This paper investigates the intermittent synchronization problem of complex dynamic network systems (CDNs) that are subject to cyber attacks. Firstly, Average Dwelling Time Ratio (ADTR) is novelly employed to unitedly describe aperiodic intermittent control and aperiodic DoS attacks, overcoming the limitations of modeling separately in traditional methods. Secondly, a short-term memory event-triggered mechanism (METM) is proposed, where the triggering condition relies in part on the error information between the current moment and only its two nearest triggering instants. Moreover, the triggering threshold can be dynamically adjusted according to the start time of the attack dormant, improving the triggering accuracy and resource utilization efficiency. Thirdly, the time axis is divided into four non-overlapping intervals depending on the working/rest status of the controller and the active/dormant scenario of the attack. Then different Lyapunov function energy growth factors are introduced. Based on a segmented iterative design, sufficient conditions ensuring exponential synchronization of the error system are derived. Finally, the effectiveness of the developed method is verified through a numerical example and an actual circuit.

This paper investigates an aperiodic sampled‐data‐based resilient control problem for a class of non‐strict feedback switched systems under denial‐of‐service (DoS) attacks. If the output values can be available only at the sampling instants, such incomplete information will make the variable non‐differentiable and increase the risk of asynchronous operation for switched systems. Moreover, it will become more serious if DoS attacks destroy both the switching and output signals. To address these challenges, a novel aperiodic sampling rule is designed. Based on the assigned sampling rule, a sampled‐data observer and an adaptive resilient controller are constructed, which not only reduce the dual‐channel transmission burden, eliminate the trouble of output being not‐differentiable, but also overcome the adverse impact of DoS attacks. What's more, the proposed sampling rule and the control strategy, relating to the switching signal, highlight the characteristics of each subsystem. The common Lyapunov stability theory can ensure all the variables of the considered closed‐loop switched systems are bounded under arbitrary switching. Finally, the simulation results of two examples are given to verify the effectiveness of the proposed method.

In this study, a sampling control problem is investigated for a class of switched linear neutral systems under asynchronous switching. By developing a novel edge‐dependent discontinuous Lyapunov function (EDDLF) approach, new exponential stability conditions are established for the considered switched system with sampled‐data partitioned feedback controllers. In addition, the switching rule characterised by admissible edge‐dependent average dwell time (AED‐ADT) is first explored for sampling asynchronous switching studies of switched systems, and tighter bounds of AED‐ADT are obtained by the EDDLF strategy. By properly assigning the sampling period and the number of segments, the proposed controller gains and smaller AED‐ADT are followed, which can guarantee the exponential stability of the closed‐loop switched system. Finally, some simulation results show the advantages of the developed control strategy.

In this paper, we consider the Von Kármán swirling-flow problem, which is described by an ordinary equations system. The explicit asymptotic solutions are given by applying the homotopy renormalization method. Furthermore, the numerical simulations verify that our asymptotic solutions have high precision and the absolute errors are less than 0.03, which means that the results obtained are truly valid and can be used practically.