Dynamic Event-Triggered Quadratic Nonfragile Filtering for Non-Gaussian Systems:Tackling Multiplicative Noises and Missing Measurements

This paper focuses on the quadratic nonfragile filtering problem for linear non-Gaussian systems under multiplicative noises,multiple missing measurements as well as the dynamic event-triggered transmission scheme.The multiple missing measurements are characterized through random variables that obey some given probability distributions,and thresholds of the dynamic event-triggered scheme can be adjusted dynamically via an auxiliary variable.Our attention is concentrated on designing a dynamic event-triggered quadratic nonfragile filter in the well-known minimum-variance sense.To this end,the original system is first augmented by stacking its state/measurement vectors together with second-order Kronecker powers,thus the original design issue is reformulated as that of the augmented system.Subsequently,we analyze statistical properties of augmented noises as well as high-order moments of certain random parameters.With the aid of two well-defined matrix difference equations,we not only obtain upper bounds on filtering error covariances,but also minimize those bounds via carefully designing gain parameters.Finally,an example is presented to explain the effectiveness of this newly established quadratic filtering algorithm.

Encrypted Finite-Horizon Energy-to-Peak State Estimation for Time-Varying Systems Under Eavesdropping Attacks: Tackling Secrecy Capacity

This paper is concerned with the problem of finitehorizon energy-to-peak state estimation for a class of networked linear time-varying systems.Due to the inherent vulnerability of network-based communication,the measurement signals transmitted over a communication network might be intercepted by potential eavesdroppers.To avoid information leakage,by resorting to an artificial-noise-assisted method,we develop a novel encryption-decryption scheme to ensure that the transmitted signal is composed of the raw measurement and an artificial-noise term.A special evaluation index named secrecy capacity is employed to assess the information security of signal transmissions under the developed encryption-decryption scheme.The purpose of the addressed problem is to design an encryptiondecryption scheme and a state estimator such that:1)the desired secrecy capacity is ensured;and 2)the required finite-horizon–l_(2)-l_(∞)performance is achieved.Sufficient conditions are established on the existence of the encryption-decryption mechanism and the finite-horizon state estimator.Finally,simulation results are proposed to show the effectiveness of our proposed encryption-decryption-based state estimation scheme.

Stochastic stability of networked control systems with network-induced delay and data dropout

This paper deals with the stochastic stability of networked control systems with the presence of network- induced delay and transmitted data dropout. Based on the Lyapunov approach, sufficient conditions for the mean-square stability of the networked control system are derived subject that the sequence of transmission interval is driven by an identically independently distributed sequence and by a finite state Markov chain, respectively. Stabilization controllers are constructed in terms of linear matrix inequalities correspondingly. An example is provided to illustrate our results.

Stabilization for nonlinear systems via a limited capacity communication channel with data packet dropout

This paper addresses the stabilization problem for a class of nonlinear systems. It is assumed that the controller can only receive the transmitted sequence of finite coded signals via a limited digital communication channel. Both state and output feedback coder-decoder-controller procedures are proposed. Stabilization conditions involving the size of coding alphabet, the sampling period, system state growth rate and data packet dropout rate are obtained. Finally, an example is given to illustrate the design procedures and effectiveness of the proposed results.

Temperature and Flow Rate Control of Diffusing Chamber

The temperature and flow rate control of diffusing chamber is one of the key technologies in the production of poly-crystal silicon thin film. As there exist some modeling uncertainties and errors in the actual system, it is difficult to guarantee the chamber variable temperature conditions and the flow rate of diffusion gas being controlled within its targeted range in the rapid thermal processing (RTP). In this paper, the control applies the programmable logic controller (PLC) to configure control hardware system, proposes expert proportional integral derivative (PID) control method to regulate the gas flow rate and H∞ control strategy to attenuate chamber modeling uncertainties and disturbances, respectively, to steer the chamber rapid variable temperature very close to the expected product temperatures. Furthermore, it designs human-machine integrated user control interface (HMI) and achieves rapid and accurately control performances for user operating production. The designed control system are simulated and tested in the application, which demonstrates that the control method has strong robustness when the modeling uncertainties, errors, parameters perturbation and disturbances, the temperature and flow rate meet the requirements of precisely trajectory following.

The nuclear cytokine IL-37a controls lethal cytokine storms primarily via IL-1R8-independent transcriptional upregulation of PPARγ

Cytokine storms are crucial in the development of various inflammatory diseases,including sepsis and autoimmune disorders.The immunosuppressive cytokine INTERLEUKIN(IL)-37 consists of five isoforms(IL-37a-e).We identified IL-37a as a nuclear cytokine for the first time.Compared to IL-37b,IL-37a demonstrated greater efficacy in protecting against Toll-like receptor-induced cytokine hypersecretion and lethal endotoxic shock.The full-length(FL)form of IL-37a and the N-terminal fragment,which is processed by elastase,could translocate into cell nuclei through a distinctive nuclear localization sequence(NLS)/importin nuclear transport pathway.These forms exerted their regulatory effects independent of the IL-1R8 receptor by transcriptionally upregulating the nuclear receptor peroxisome proliferator-activated receptor(PPARγ).This process involved the recruitment of the H3K4 methyltransferase complex WDR5/MLL4/C/EBPβand H3K4me1/2 to the enhancer/promoter of Pparg.The receptor-independent regulatory pathway of the nuclear IL-37a–PPARγaxis and receptor-dependent signaling by secreted IL-37a maintain homeostasis and are potential therapeutic targets for various inflammatory diseases,including sepsis.

Aqueous Chemistry of Typical Geothermal Springs with Deep Faults in Xinyi and Fengshun in Guangdong Province,China

This paper investigated aqueous chemistry for two geothermal spring groups responsive and sensitive to flow fluctuations induced by earthquakes. Quake monitorings are favored for their being in residential areas with well-preserved natural flow systems in Xinyi City＇s Xijiang Hot Springs and Fengshun County＇s Shihu Hot Spring. The hot springs are typical in temperatures and flow rates in southern China＇s Guangdong Province. Physical and chemical conditions deep down in the heat sources are important constraints on earthquake, fluid flow, reactive solute transport and heat transfer, but remain challenging to address via field observations and numerical experiments. In this paper, we made daily and annual observations on flow rates, temperature, and/or aqueous chemistry. We employed strontium isotopes as tracers for the water sources, equilibrium phase diagram for K-feldspar and albite stability, and Na-K-Mg diagram for heat reservoir temperatures. The abundant sulfite content in Xi- jiang Hot Springs is discussed. Our main finding are that the deep fault springs are characterized by low reduction-oxidation potential at around -200- -150 mV and relatively large daily flow variations. The resuits provide scientific background features on the field sites regarding earthquake monitoring and predictions and geothermal reservoir.

Recent advances in synthesis of organosilicons via radical strategies

Organosilicon compounds play an important role in the fields of materials science,pharmacy,and organic synthesis.The development of effective approaches for the preparation of these compounds have also become a research focus in organic synthesis.In recent years,free radical synthesis of organosilicons has been vigorously developed,which generally has the advantages of milder synthesis conditions,higher yields and selectivity,and free of precious metal catalysts compared with traditional strategies.This article reviews research progresses in the synthesis of organosilico n compounds by free radical pathways since 2016.In most cases,the radical silylation is achieved based on the reaction of silyl radicals,which are triggered by four routes including peroxide,transition-metal-induced peroxide decomposition,alkali,photocatalysis.The alkyl radicals can also initiate the radical silylation for the generation of C(sp^(3))—Si bonds.

Single-atomic-site iron on N-doped carbon for chemoselective reduction of nitroarenes

A facile,gram-scale and sustainable approach has been established for the synthesis of single-atomic-site iron on N-doped carbon(Fe_(SA)@NC-20A)via the pyrolysis of aniline modified FeZn-ZIFs,in which the synthesis of zeolitic imidazolate frameworks(ZIFs)can be accomplished in water at room temperature,and no acid etching is required.The as-synthesized catalyst exhibits better performance on the chemoselective hydrogenation of nitroarenes with a broad substrate scope(turnover frequency(TOF)up to 1,727 h^(-1),23 examples)than most of previously reported works.Based on high-angle annular dark field scanning transmission microscopy(HAADF-STEM)images in combination with X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),electron spin resonance(ESR),and Mossbauer spectroscopy,Fe is dispersed as single atoms via forming FeNx(x=4-6).This work not only determines the active sites of FesA@NC-20A for hydrogenation(FeN4),but also proposes tentative pathways for both N-H activation of hydrazine and the reduction of nitroarene on FeN4 site,both of which are the key steps for the hydrogenation of nitroarenes.In addition,this catalyst shows excellent stability,and no significant activity degradation is observed when recycling for 10 times or restoring in air for 2 months.

The ketogenic diet for paediatric patients with super-refractory status epilepticus in febrile infection-related epilepsy syndrome

Objective:To investigate the effect and safety of ketogenic diet(KD)for the treatment of paediatric patients with super-refractory status epilepticus(SRSE)in febrile infection-related epilepsy syndrome(FIRES).Method:From January 1,2015 to October 31,2017,ten critically ill paediatric patients with SRSE in FIRES were included in this study and treated with KD.The treatment effects of KD were evaluated by using continuous encephalography(CEEG)and amplitude-integrated electro-encephalography(aEEG).Results:All 10 patients fulfilled the diagnostic criteria of SRSE in FIRES and achieved ketosis within 24–72 h following the administration of KD.CEEG and aEEG were monitored for several weeks to assess the efficacy of KD on status epilepticus(SE).SE was contained in 8 patients within 2 to 19 days after initiation of KD,and KD was discontinued in the other 2 patients.One of the 10 patients demonstrated severe adverse effects.Conclusion:KD may be an alternative and safe treatment option in critical paediatric patients with SRSE in FIRES.