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AbstractBackground Prostate cancer (PCa) is poor response to the immunotherapy for its high heterogeneity of immune microenvironment. In this study, we aim to introduce a new immune subtype for PCa involving M2 tumour associated macrophages (M2-TAMs).Methods Three hundred and sixty-two PCa patients and matched normal prostate tissues were selected from the Cancer Genome Atlas and Gene Expression Omnibus databases. Patients’ immune infiltration characters were then analyzed based on the gene expressions. The immune subtypes were identified by the method of unsupervised hierarchical clustering. Finally, the relationship between the M2-TAMs infiltration and anti-programmed death-ligand-1 (PD-L1) therapy was investigated in the IMvigor210 cohort.Results PCa expressed lower immune-related genes levels compared with the adjacent normal tissues. Based on the proved immunosuppressive mechanisms in PCa, tumour patients were classified into three independent subclasses with high infiltrated cytolytic activity (CYT), M2-TAMs and regulatory T cell (Tregs), respectively. Among these subtypes, M2-TAMs infiltration subtype showed the worst clinicopathological features and prognosis compared with the other two subtypes. The results of the IMvigor210 cohort demonstrated poor response of anti-PD-L1 therapy for patients with high M2-TAMs infiltration.Conclusion Prostate tumours involved in significant immunosuppression, and high infiltration of M2-TAMs can be applied to predict the effect of anti-PD-L1 therapy.Key MessagesPCa patients can be classified into three immunotypes of high infiltrated CYT, M2-TAMS, and Tregs according to the immunosuppressive mechanisms.High M2-TAMs infiltration subtype reflected the worst clinical characters, immune infiltration, and lowest expression of immune checkpoint inhibitors among the three subclasses in PCa.High M2-TAMs infiltration predicts the low response rate of anti-PD-L1 therapy.

Family and school environments are assumed to be associated with and influence aggressive behaviors. However, which specific risk factors within these environments that are associated with aggressive behavior are unclear. The goal of this study is to identify family and social environmental qualities that are related to aggression among Chinese adolescents. Survey data were obtained from 3,213 randomly selected urban high school students ages 10 through 18 in southern China. Lower parental attachment, higher family income, mother's higher education levels, father's parenting goals, rough or changeable parenting styles, unsuitable peer relationships, and inadequate social atmospheres at school serve as risk factors for aggression among Chinese adolescents. Our findings provide some implications for understanding aggression among adolescents and suggests possible interventions to help overcome potential environmental risk factors and thus to prevent aggressive behavior in school.

This paper studies the decentralized $H_{\infty }$ secure load frequency control issue and circuital realization of multi-area networked power systems subject to random transmission delays and deception attacks. To make full use of the stochastic feature of the network-induced transmission delay, its distribution described by the probability density function is utilized. Due to this feature, the normal control signal and the injected deceptive attack signal transmitted over the network can be formed as two distributed delay terms. Then, the $i$ th load frequency control area is established as a new distributed delay system, in which the delay probability density is treated as the distributed kernel. By utilizing an integral inequality dependent on the kernel, new sufficient controller design conditions are derived to guarantee the system stability with given $H_{\infty }$ performance. Moreover, a physical execution approach is addressed to transfer the load frequency control systems into electrical analogy circuits. The effectiveness of the proposed approach is illustrated via the professional simcape toolbox in Simulink/MATLAB for circuit simulations. [ABSTRACT FROM AUTHOR]

In this brief, a type of novel fully distributed adaptive protocols is designed for achieving leader‐follower multi‐agents tracking. The design procedure constitutes three steps. First, a local observer is constructed for each agent (including the leader) in virtue of its own inputs and outputs, aiming to estimating of that agent's state. Second, to propagate the estimate of the leader from target followers to all the followers, a distributed adaptive estimator is then proposed, via embedding with time‐varying coupling weights. At last, an elegant controller is designed for each follower based on the estimate of its own state and the estimate of the leader's state. The rigorous convergence analysis is provided. Finally, the simulation results validate the effectiveness of the proposed protocols. [ABSTRACT FROM AUTHOR]

In this article, an event-triggered practical fixed-time containment control issue for stochastic nonlinear multiagent systems is addressed. The event-triggering mechanism is designed for the controller update which is reduced update frequency. In combination with the backstepping technique and fuzzy logic systems, an adaptive fuzzy containment control strategy is developed for stochastic uncertain multiagent systems. By adopting the protocol, an adaptive containment controller is devised, which can ensure that the containment errors gather to a small range in fixed time. Finally, simulation results for the practical example demonstrate the correctness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Due to the high resistance/reactance (R/X) ratio of a low-voltage microgrid (LVMG), virtual complex impedance-based $P-\dot {V}/Q-\omega $ droop control is adopted in this article as the primary control (PC) technique for stabilizing the system. A distributed event-triggered restoration mechanism (ETSM) is proposed as the secondary control (SC) technique to restore the output-voltage frequency and improve power sharing accuracy. The proposed ETSM ensures that neighboring communication happens only at some discrete instants when a predefined event-triggering condition (ETC) is fulfilled. In general, the design of the ETC is the crucial challenge of an event-triggered mechanism (ETM). Thus, in this article, a static ETM (SETM) is proposed as the ETC at first, where two static parameters are utilized to reduce the triggering frequency. Bounded stability is ensured under the SETM, which means that the output-voltage frequency is restored to the vicinity of its nominal value, and close to fair utilization of the distributed generators (DGs) is achieved. To further improve the power sharing accuracy and accelerate the regulation process, a dynamic ETM (DETM) is then introduced. In the DETM, two dynamic parameters that converge to zero in the steady state are designed, which promises asymptotic stability of the system. Besides, Zeno behavior is excluded in both mechanisms. An LVMG consisting of four DGs is constructed in MATLAB/Simulink to illustrate the effectiveness of the proposed methods, and the simulations correspond with our theoretical analysis. [ABSTRACT FROM AUTHOR]

In distribution networks with a high penetration of photovoltaic (PV), a coordination between reactive power compensation (RPC) of PV inverter and active power compensation (APC) of battery energy storage system (BESS) is always used in voltage regulation (VR). Since using a periodical VR inevitably increases communication utilization, how to design a new event-triggered one to reduce communication burden while achieving comprehensive voltage governance with the required minimum BESS sizing? Therefore, an event-triggered hybrid VR method is proposed in this paper. Firstly, an event-triggered communication is designed based on the changes in bus voltage and sensitivity, thereby defining all operating instants into transmission and ordinary sampling types. For the voltage violation issue at the transmission instants, a network-wide coordinated proportional RPC-APC is then designed, which keeps constant during one transmission interval. For the additional voltage fluctuation at the ordinary sampling instants in the interval, a local RPC-APC is additionally designed to yield a fast suppression without using any communication. In addition, the required minimum BESS sizing is obtained by calculating the total APC for VR requirement, which gives a reference in configuring BESS. Finally, the case study is conducted to demonstrate the effectiveness of this method. [ABSTRACT FROM AUTHOR]

The strong stochastic nature of wind power generation makes it extremely challenging to accurately predict and support the planning and operation of modern power systems with significant penetration of renewable energy. This article proposes a two-step wind power prediction method, which consists of two phases: long time-scale coarse prediction and short time-scale fine correction. In the long time-scale phase, a complementary ensemble empirical mode decomposition-based sigma point Kalman filter approach is proposed to coarsely predict wind power merely with historical data. In the short time-scale phase, a deep deterministic policy gradient approach learns from real-time weather information to correct the coarse prediction result, which results in an improved prediction accuracy. A real-life case study confirms that the proposed method can properly predict wind power generation and have a better prediction accuracy than existing techniques, thus offering a viable and promising alternative for predicting wind power generation. [ABSTRACT FROM AUTHOR]

This paper proposes a co-estimation and resilient compensation control framework for multi-area load frequency control (LFC) systems in the presence of false data injection (FDI) attacks and denial-of-service (DoS) attacks. To relax the requirement on existing DoS attack models, which are usually considered under the assumption that both its frequency and duration are constrained, a new DoS model within a known bounds of the sleeping and active period of the attack signal is proposed. The injected FDI attack signal is generated by an external dynamic systems. A switching impulsive observer and a switching state observer are constructed to estimate the unknown FDI attack signal and the system state, respectively. Moreover, a new exponential stability criteria of the output feedback multi-area LFC systems under DoS and FDI attacks is first derived by using attack parameter dependent time varying Lyapunov function method. Then, a co-design method of a resilient attack compensation controller, state estimator, and attack estimator is developed. Finally, case studies are considered for verification of the effectiveness of the proposed theoretical results. [ABSTRACT FROM AUTHOR]

In this article, a cloud-edge collaboration based control framework is proposed for the voltage regulation and economic operation in incremental distribution networks (IDN). The voltage regulation and economic operation, usually considered in separated aspects, can be integrated in a hierarchical control method by coordinating the active power and reactive power of distributed generators (DGs) and distributed storages (DSs) in an “active” mode. Promising the voltage security of the IDN, the upper level multiobjective optimization is formulated to maximize the consumption of the DGs, moreover, the lower level model predictive control (MPC) aims to regulate the dynamics of the DGs and DSs based on the established state space model. Time delay in the downstream channel is considered due to the open environment of the proposed control framework, which can be eliminated by using the PCM derived from the MPC considering model uncertainty. Finally, simulation results demonstrate the validity and robustness of the proposed method. [ABSTRACT FROM AUTHOR]

This article investigates the problem of event-triggered switched fault-detection filters for networked stochastic systems under Denial-of-Service (DoS) jamming attacks. The considered DoS attacks are imposed by a power-constrained pulse-width modulated (PWM) jammers. A new resilient event-triggered communication strategy is designed to save network resources while counteracting the periodic PWM DoS jamming attacks. A new event-based switched residual model for fault detection is established, which characterizes the effects of the event-triggering scheme and DoS attacks simultaneously. By employing a piecewise stochastic Lyapunov functional method, sufficient conditions for achieving the exponentially mean-square stability and the prescribed performance of the residual system under the DoS attacks are formulated in terms of linear matrix inequalities. Consequently, co-design of the desired fault-detection filter parameters and the triggering parameters is achieved if the previous presented conditions are feasible. At last, an F-18 aircraft model is provided to show the validity of the proposed theoretical results. [ABSTRACT FROM AUTHOR]

This brief studies event-triggered control problem for consensus tracking based only on relative output information. First, with the sporadic relative outputs, an event-triggered observer is designed to estimate the relative states. Second, based on the intermittent estimate, an event-sampled controller is constructed to achieve the consensus tracking. Compared with the existing observer-based protocols that are designed with absolute outputs to reconstruct each agent’s states, the current protocol is born to have two fascinating features. First, the relative states rather than agent’s states are estimated, and meanwhile no observer information is inter-exchanged through network. This structure can not only save communication resources, but also reduce the possibility of encountering cyber attacks. Second, the triggering instants associated with observer and controller are independent, showing that the updates of observer and controller are asynchronous. Numerical simulation illustrates the proposed control approach. [ABSTRACT FROM AUTHOR]

Resilient distributed coordination control is studied on multiarea power systems with low inertia under hybrid attacks, including denial-of-service (DoS) attack and deception attack. The communication among various areas under the DoS attack is deteriorated to switching residual topologies whose time characteristic is modeled by model-dependent average dwell time (MDADT). Deception attack with malicious strategy targeting at negative feedback control is modeled by a sign function. To obtain resilience performance of the power system under low inertia and hybrid attacks, resilient distributed scheme combining load-frequency control (LFC) with virtual inertia control (VIC) is proposed. Then, resilient frequency control problem of the studied power system is converted to $H_{\infty }$ control of the switched nonlinear system. By employing the Lyapunov stability theory and switched system method, the resilient conditions are given by the lower bound of the average dwell time of each residual topology and the upper bound of deception attacks. Furthermore, a linear matrix inequality (LMI) technique is used to design the distributed resilient control gains of the LFC-VIC scheme. Finally, a simulation of four-area power systems is carried out to verify the validness of our theory. [ABSTRACT FROM AUTHOR]

This article is concerned with attack-resilient event-triggered $H_{\infty }$ filtering for a class of networked nonlinear systems described by an interval type-2 (IT2) fuzzy model. Suppose that data transmission from the plant to the filter is completed through a wireless sensor network subject to denial-of-service attacks (DoS). In order to save the limited network bandwidth and resist the effects of DoS attacks, a resilient event-triggered communication scheme is devised. Then, an attack-resilient IT2 filter model is introduced to estimate system states of the nonlinear plant. Based on a piecewise Lyapunov–Krasovskii functional, sufficient conditions are obtained to ensure that the filtering error system is exponentially stable and satisfies a certain $H_{\infty }$ performance level. Moreover, explicit expressions for the attack-resilient filter gain parameters and event-triggering parameters can be derived if a set of linear matrix inequalities are feasible. Finally, a practical example is provided to demonstrate the effectiveness of the proposed theoretical results. [ABSTRACT FROM AUTHOR]

Summary: Due to lack of support from the main grid, the problem of frequency over‐limitation is easily caused during heavy load disturbance occurs in the islanded microgrid (MG). For this reason, an improved curve‐shaped droop control strategy, which is composed by virtual synchronous generator (VSG) and an improved droop control, is designed to ensure the frequency stable of the MG system. In the contributed strategy, when the frequency of MG is changed within the normal range, the VSG control will be adopted to maintain the stability of the output power and frequency, this method can ensure that the frequency can be adjusted within the stable range rapidly; when the frequency deviation is serious, the proposed strategy will select the improved droop control strategy to ensure the output power equals to the load demand, and to ensure that the controlled frequency cannot lower than the minimum value. In addition, in order to suppress the voltage deviation and the system oscillation caused by the switching of the control methods, a voltage synchronization control strategy is also proposed, which can realize the smooth switching of the two control strategies and guarantees the voltage stable of the MG system. The effectiveness of the proposed methods is verified by simulation experiments via matlab/Simulink software. [ABSTRACT FROM AUTHOR]

Relative states between neighbors are ubiquitous in large-scale systems, and the relative state saturations need to be considered when designing controllers based on this relative state information. This article investigates the consensus control of the delayed multiagent systems under the relative state saturations. By means of an incidence matrix, the consensus under the relative state saturations is transformed into the stability of edge dynamics operating on constrained sets. To enable the edge states to stay within the constrained sets, a novel nonlinear protocol is designed by embedding an elaborate saturation function. Sufficient conditions are identified, under which not only consensus is achieved but also relative state saturations do not occur. Moreover, this analytical result can address the consensus problem while preserving connectivity, within the limited communication range framework. Simulations illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

This note is concerned with bandwidth allocation-based switched dynamic triggering control under DoS attacks and time delay. To prevent DoS attacks from causing open-loop unstable operation of the system with single-channel transmission, we present a primary-redundancy (PR) communication structure on the basis of limited bandwidth allocation; the correlation of communication delay bound between PR channels is introduced. To save the limited bandwidth, we propose a dynamic the event-triggered mechanism (DETM). Then, a switched delay system model is established to describe system dynamic driven by primary channel control, redundancy channel control, and unstable operation under DoS attacks. Further, by using the convex combination method, a switching law for PR channel is designed with the aim of keeping the concealment of the redundancy channel. With the switching law, a criterion of exponential stability is obtained by using piecewise Lyapunov–Krasovskii functional method. A co-design method is proposed to obtain feedback control gains, DETM parameters and switching law parameters. Finally, two simulation examples are illustrated to verify the validness of our proposed method. [ABSTRACT FROM AUTHOR]

This article investigates the consensus tracking of exponentially unstable multiagent systems with time-varying input delay. The truncated predictor feedback approach is utilized for designing delay-dependent state and output feedback protocols. And the explicit conditions that can realize consensus tracking are established in terms of parametric Lyapunov equations and scalar inequalities. Besides, the protocol design algorithms under the maximum allowable delay and the maximum convergence rate are, respectively, provided. Compared with the existing results, the salient characteristic of the current results is to reveal the quantitative relationship among the time delay, unstable plant, network topologies, and the convergence rate. Specifically, for achieving the consensus tracking, the synchronization force from network connectivity needs to dominate the anti-synchronization force from unstable open-loop poles and input delays; the maximum allowable input delay is inversely proportional to the sum of the unstable open-loop poles; the convergence rate becomes smaller as the input delay bounds or/and the sum of the unstable poles in plant increase. Numerical simulations confirm the effectiveness of the proposed theoretical design. [ABSTRACT FROM AUTHOR]