Jun Fu – författare

This book approaches its subject matter in a way that provides Lyapunov function analysis and event-triggered design methods for switched dynamic systems in terms of sampled-data control, hysteresis switching control, and fault-tolerant control.

This book presents several novel design methods on event-triggered control of switched linear systems, in which the events inclusively consist of not only switching itself but events occurring as the switched systems evolve. The features of our approaches lie in threefold: i) In the framework of sampled-data control, a bond between the sampling period and the average dwell time of the asynchronous switched linear neutral systems is revealed, with which stabilization conditions are derived for periodic sampling and event-triggered sampling mechanisms, respectively. ii) New event-triggered control strategies are proposed for switched linear systems and switched delay systems including switched neutral systems. The Zeno phenomenon canbe excluded easily since the constant threshold can guarantee the existence of minimum positive lower bound between two continuous sampling intervals. iii). Two new fault-tolerant control methods are presented for switched cascade systems, with structural uncertainties existing in both system matrices and input matrices of the linear subsystems, by using the average dwell-time techniques. The proposed control design works on both the switched systems with actuator faults and its nominal systems (i.e., without actuator faults) without necessarily changing any structures and/or parameters of the proposed controllers. This book presents several systematical analysis and design methods for event-triggered control of switched systems in terms of the Lyapunov-based stability. It is of great significance to theoretical research and practical applications for switched systems.

Networked switched system has emerged as an essential system model in the field of control due to its accurate reflection of the wide-area distribution and typical switching characteristics of increasingly sophisticated controlled objects in engineering practice. The openness of communication networks, the limitation of communication resources, and the complexity of switching behaviors make it a challenging task to ensure the steady-state and transient performance of the output regulation of networked switched systems.

This book proposes several novel methodologies for output regulation of networked switched systems from the perspective of both steady-state and transient performance. The core features of our approaches are fourfold: i) Without imposing stability requirements on individual subsystems and all switching instants, a series of innovative dwell-time switching technologies are established to handle the issue of output regulation for networked switched systems with severely unstable dynamics under event-triggering strategies in the presence of cyber attacks. ii) Taking into account switching rules and cyber attack parameters within the event-triggered control framework, event detection conditions, modal matching conditions, and event waiting conditions are constructed, and a series of new event-triggering mechanisms are proposed to effectively enhance network resource utilization and secure steady-state performance of networked switched systems. iii) Typical cyber attacks have unique consequences on the secure steady-state performance of networked switched systems with severely unstable dynamics due to the short activation time of a single subsystem and the necessity to relay the switching signal through the network. To this purpose, the consecutive asynchronous switching behaviors of the subsystem or controller resulting from a long-duration DoS attack or an integrity deception attack incorporating switching signal tampering are investigated. iv) To deal with the transient performance fluctuations of the closed-loop system caused by factors such as mismatch switching between the subsystem and the corresponding controller, data update at event-triggering instants, cyber attack blocking and tampering of transmitted data, etc., bumpless transfer control strategies are formulated in the interpolation type and multi-source type, balancing the transient and steady-state performances of the output regulation of networked switched systems. This book presents these topics in a systematic way, which is of tremendous importance to both theoretical research and practical applications involving switched systems.

This monograph studies the synchronization control of Markovian complex neural networks with time-varying delays, and the structure of the book is summarized as follows. Chapter 1 introduces the system description and some background knowledges, and also addresses the motivations of this monograph. In Chapter 2, the stochastic synchronization issue of Markovian coupled neural networks with partially unknown transition rates and random coupling strengths is investigated. In Chapter 3, the local synchronization issue of Markovian neutral complex networks with partially information of transition rates is investigated. The new delay-dependent synchronization criteria in terms of LMIs are derived, which depends on the upper and lower bounds of the delays. In Chapter 4, the local synchronization issue of Markovian nonlinear coupled neural networks with uncertain and partially unknown transition rates is investigated. The less conservative local synchronization criteria containing the bounds of delay and delay derivative are obtained based on the novel augmented Lyapunov-Krasovskii functional and a new integral inequality. In Chapter 5, the sampled-data synchronization issue of delayed complex networks with aperiodic sampling interval is investigated based on enhanced input delay approach, which makes full use of the upper bound of the variable sampling interval and the sawtooth structure information of varying input delay. In Chapter 6, the sampled-data synchronization issue of Markovian coupled neural networks with mode-dependent interval time-varying delays and aperiodic sampling intervals is investigated based on an enhanced input delay approach. Furthermore, the mode-dependent sampled-data controllers are proposed based on the delay dependent synchronization criteria. In Chapter 7, the synchronization issue of inertial neural networks with time-varying delays and generally Markovian jumping is investigated. In Chapter 8, we conclude the monograph by briefly summarizing the main theoretical findings.

This book presents a comprehensive, state-of-the-art review of the latest progresses in UHMWPE biomaterials, which has been critical for the performance and longevity of joint implants. Oriented by clinical challenges to UHMWPE-based joint implants, it introduces the processing, crosslinking, structural manipulation, oxidation mechanism, stabilization, drug delivery, and wear, as well as clinical performance, biomechanics, and simulated studies of joint implant based on UHMWPE with low wear, which are aimed to tackle or minimize the adverse effect related to wear and wear debris. These contributions provide fundamentals of chemistry and physics of UHMWPEs to help understand the clinical performances of UHMWPE based joint implants. Perspectives to next generation UHMWPE to meet the unmet challenges in clinical use are included.

This book examines how emerging forms of citizenship are shaped by young people in digital spaces as way of making sense of contemporary Chinese society, forming new identities, and negotiating social and political participation. By focusing on Chinese young adults'' everyday online practices, the book offers a unique treatment of the topic of young people and the Chinese Internet that navigates between the dominant focus on censorship on the one hand and protest and politicized action on the other.

The book brings the focus of research from highly visible or spectacular forms of collectivity, belonging, and identification exhibited in young people''s online practices to young people''s everyday social and cultural engagement through new media. It brings new insights by understanding the meanings of young people''s mundane and everyday online engagement for their citizenship learning, identity performance, and their formation of political subjectivity. Readers will gain insightsinto citizenship in China, and young people and the Chinese Internet.