查看更多>>摘要：The Lebanese wireless device explosion incident has drawn widespread attention， involving devices such as pagers， walkie-talkies， and other common devices [1]。 This event has revealed and highlighted the security vulnerabilities in global supply chains from raw material manufacturing and distribution to the usage of devices and equipment， signaling the onset of a new wave of “supply chain warfare” [2]。 Even worse， with the rapid proliferation of Internet of Things (IoT) devices and smart hardware， the fragility of global supply chains would become increasingly fatal and significant， since almost all devices of daily usage could be maliciously programmed and triggered as weapons of massive destruction。 Given this， we need new thinking and new approaches for improving supply chain security [3]。 With its decentralized， tamper-proof， and highly traceable characteristics， blockchain technology is considered an effective solution to address these security threats [4]， [5]。 How to secure the entire lifecycle of smart devices， from production and transportation to usage， through blockchain-enabled safety management and protection， has become a pressing issue that requires immediate attention。
查看更多>>摘要：The 2024 Lebanon pager explosions represent one of the most unexpected and devastating technological incidents in recent history。 On September 17 and 18， 2024， thousands of pagers and walkie-talkies exploded simultaneously across Lebanon and parts of Syria， resulting in 42 deaths and more than 3500 injuries。 These handheld communication devices， previously regarded as secure and low-profile， were rigged with concealed explosives and remotely triggered by attackers。 The explosions primarily occurred when users either responded to the pager's signal or interacted with the walkie-talkies， leading to devastating injuries。 Hospitals across Lebanon were overwhelmed， as victims arrived with severe trauma， including facial and hand lacerations， blindness， and other injuries [1]。
查看更多>>摘要：Power electronic-interfaced renewable energy sources (RES) exhibit lower inertia compared to traditional synchronous generators。 The large-scale integration of RES has led to a significant reduction in system inertia， posing significant challenges for maintaining frequency stability in future power systems。 This issue has garnered considerable attention in recent years。 However， the existing research has not yet achieved a comprehensive understanding of system inertia and frequency stability in the context of low-inertia systems。 To this end， this paper provides a comprehensive review of the definition， modeling， analysis， evaluation， and control for frequency stability。 It commences with an exploration of inertia and frequency characteristics in low-inertia systems， followed by a novel definition of frequency stability。 A summary of frequency stability modeling， analysis， and evaluation methods is then provided， along with their respective applicability in various scenarios。 Additionally， the two critical factors of frequency control—energy sources at the system level and control strategies at the device level—are examined。 Finally， an outlook on future research in low-inertia power systems is discussed。
查看更多>>摘要：This paper presents a fixed-time equivalent-input-disturbance (EID) approach to deal with the problem of robust output-feedback control for perturbed uncertain systems。 This method uses the basic structure of the conventional EID approach and treats uncertainties and disturbances as a lumped disturbance on the control-input channel。 A fixed-time state observer enables state estimation， which resolves the causality issue in an EID-based control system， is finished in a fixed time。 An implicit Lyapunov function， the homogeneity with dilation， the input-to-state stability， and the small-gain theorem are used to analyze the convergence and robustness of the EID-based system with measurement noise。 Numerical and experimental results are presented to demonstrate the effectiveness and superiority of the proposed method。
查看更多>>摘要：The article investigates the optimal energy management (OEM) problem for microgrids。 To figure out the problem in fixed time and alleviate communication load with limited resources， this article devises a novel fixed-time stability lemma and an event-triggered (ET) fixed-time distributed OEM approach。 Using Lyapunov stability theory， the distributed approach has been proven to converge in fixed time and the upper bound on convergence time can be derived without dependence on the initial states。 The dynamic ET method is raised to dynamically adjust the triggering threshold and reduce communication redundancy。 In addition， Zeno behavior is avoided。 Simulations are given to show the effectiveness and advantage of the designed distributed OEM method。
查看更多>>摘要：This article develops a novel data-driven safe Q-learning method to design the safe optimal controller which can guarantee constrained states of nonlinear systems always stay in the safe region while providing an optimal performance。 First， we design an augmented utility function consisting of an adjustable positive definite control obstacle function and a quadratic form of the next state to ensure the safety and optimality。 Second， by exploiting a pre-designed admissible policy for initialization， an off-policy stabilizing value iteration Q-learning (SVIQL) algorithm is presented to seek the safe optimal policy by using offline data within the safe region rather than the mathematical model。 Third， the monotonicity， safety， and optimality of the SVIQL algorithm are theoretically proven。 To obtain the initial admissible policy for SVIQL， an offline VIQL algorithm with zero initialization is constructed and a new admissibility criterion is established for immature iterative policies。 Moreover， the critic and action networks with precise approximation ability are established to promote the operation of VIQL and SVIQL algorithms。 Finally， three simulation experiments are conducted to demonstrate the virtue and superiority of the developed safe Q-learning method。
NETL
NSTL
IEEE