Chongyi Cui

This research delves into the passivity-based pinning synchronization problem for switched directed networks (SDNs) within the context of a sampled-data-based event-triggered (SDET) communication environment. An improved state-dependent switching strategy (SDSS) using sampled measurements alongside a novel time-dependent Lyapunov-Krasovskii functional (LKF) approach is constructed. Subsequently, a relaxed passivity analysis framework is then presented, ensuring that the resultant synchronization error system (SES) remains passive, and that the examined SDNs achieve asymptotic synchronization in the absence of external inputs. Unlike conventional strategies, the proposed switching protocol depends exclusively on system states at discrete sampling instants and effectively utilizes historical state data, yielding a less conservative theoretical framework for passivity synthesis in SDNs. Furthermore, the resulting synchronization criterion is independent of the number of network nodes, rendering it suitable for SDNs with large size. Ultimately, two examples involving relevant application in image encryption and decryption are provided to verify the effectiveness and applicability of the proposed scheme, and highlight the distinct advantage of switching behaviors in enhancing encryption confidentiality.

This paper investigates distributed $\ell _{\infty }$ filtering problem for discrete-time switched delayed systems (DTSDSs) in sensor networks (SNs) with dynamic event-triggered communication. Given that the presence of attacks can compromise the integrity and availability of data, as well as the critical role of switching signals in shaping the behavior of switched systems, a novel event-driven distributed filter is explored in scenarios where the switching signal of the controller experiences a denial-of-service (DoS) attack, characterized by bounded attack frequency and duration. It is significant to mention that the persistent and recurrent nature of attacks compromises the transmission of switching signals, resulting in significant asynchronous discrepancies between the switching of the filtering error system (FES) and the controller. To address the asynchronous behavior induced by DoS attacks, a piecewise time-dependent Lyapunov-Krasovskii functional (PTLKF) tailored to the characteristics of DTSDSs is proposed. Subsequently, sufficient conditions with reduced conservatism are formulated to ensure the exponential stability of the FES, while also guaranteeing an enhanced $\ell _{\infty }$ disturbance attenuation performance. Finally, two simulation examples are provided to exemplify the superiority and applicability of the proposed filtering technique.

This research explores the synchronization problem in directed networks (DNs) under an intermittent communication controller, employing an event-triggered transmission technique that relies on sampling data. Upon analyzing the prior relevant results, it was observed that the derived synchronization conditions are closely related to the number of nodes in networks, reflecting the increasing computational complexity as the number of nodes grows, which makes obtaining a solution within a finite time challenging. To overcome this difficulty, this paper designs a novel intermittent controller and establishes a piecewise time-dependent Lyapunov-Krasovskii functional (PTDLKF) predicated on work and rest intervals of operation for the synchronization system. Next, an event-triggered synchronization method based on sampling data is explored to derive sufficient conditions that ensure asymptotic convergence of synchronization errors in the intermittent context. Importantly, the verification of matrix conditions in the established synchronization criterion is not contingent on the node count in networks. Finally, two simulation examples are provided to substantiate the applicability of the formulated synchronization method in the intermittent communication.

Sampled-data-based event-triggered (SDET) communication techniques have found extensive applications in the research of synchronization and consensus in directed networks (DNs). However, as the quantity of nodes in a network expands, existing investigations encounter difficulties in obtaining solutions within finite computation times due to computational complexity. For coping with this scenario, a novel event-triggered pinning quasi-synchronization approach is explored in this research for a category of switched directed networks (SDNs) with sampling measurements. By developing a time-dependent Lyapunov–Krasovskii functional (LKF) and implementing a state-dependent switching strategy utilizing sampling measurements, sufficient conditions are formulated to assure that the synchronization errors are ultimately bounded in an exponential fashion. Different from previous relevant findings, the verification of matrix conditions in the derived synchronization criterion no longer depends on the number of nodes in networks, making it more suitable for large-scale SDNs. Ultimately, two simulation examples are incorporated to elucidate the applicability of the newly crafted synchronization methodology.