Dear Editor,This letter deals with the set stabilization of stochastic Boolean control networks(SBCNs)by the pinning control strategy,which is to realize the full control for systems by imposing control inputs on a fr...Dear Editor,This letter deals with the set stabilization of stochastic Boolean control networks(SBCNs)by the pinning control strategy,which is to realize the full control for systems by imposing control inputs on a fraction of agents.展开更多
Dear Editor,This letter considers the finite-time stability(FTS)problem of generalized impulsive stochastic nonlinear systems(ISNS).By employing the stochastic Lyapunov and impulsive control approach,some novel criter...Dear Editor,This letter considers the finite-time stability(FTS)problem of generalized impulsive stochastic nonlinear systems(ISNS).By employing the stochastic Lyapunov and impulsive control approach,some novel criteria on FTS are presented,where both situations of stabilizing and destabilizing impulses are considered.Furthermore,new impulse-dependent estimation strategies of stochastic settling time(SST)are proposed.展开更多
Dear Editor,This letter studies the problem of sliding mode control(SMC)design for recurrent neural networks(RNNs)with impulsive disturbances and time-varying transmission delays.To this end,an appropriate integral sl...Dear Editor,This letter studies the problem of sliding mode control(SMC)design for recurrent neural networks(RNNs)with impulsive disturbances and time-varying transmission delays.To this end,an appropriate integral sliding surface function and SMC law are adopted for use under impulsive disturbances and time-varying delays.展开更多
Dear Editor,Over the past decades,cooperative control and distributed optimization have gained significant research attention due to their broad applications such as signal processing,robotics,and social networks[1],[...Dear Editor,Over the past decades,cooperative control and distributed optimization have gained significant research attention due to their broad applications such as signal processing,robotics,and social networks[1],[2].As a fundamental component of distributed control and optimization,the issue of average consensus has become a recurring topic of interest[3],[4].展开更多
Ferroelectric materials possessing exceptional piezoelectric attributes have garnered widespread utilization in various applications.Solid solution systems improve piezoelectric properties through multiphase mixing,bu...Ferroelectric materials possessing exceptional piezoelectric attributes have garnered widespread utilization in various applications.Solid solution systems improve piezoelectric properties through multiphase mixing,but the methodologies for effective design remain wanting.Based on the Landau–Devonshire theory,we propose a theoretical design method.Binary materials with morphotropic phase boundary(MPB)compositions are added with new elements to increase the free energy of the original stabilized phase and lower the energy barrier(EB).Flatter EBsand higher piezoelectric coefficients are found at the phase boundaries of the ternary system.By calculating the phase diagram,piezoelectric coefficient,dielectric constant,polarization,and EBs,we reveal the origin of the highest piezoelectric coefficient at the phase boundaries.This study underscores the importance of the EBs for polarization rotation in characterizing piezoelectric properties and proposes a theoretical design method for exploring materials with high piezoelectric coefficients.展开更多
In the realm of microgrid(MG),the distributed load frequency control(LFC)system has proven to be highly susceptible to the negative effects of false data injection attacks(FDIAs).Considering the significant responsibi...In the realm of microgrid(MG),the distributed load frequency control(LFC)system has proven to be highly susceptible to the negative effects of false data injection attacks(FDIAs).Considering the significant responsibility of the distributed LFC system for maintaining frequency stability within the MG,this paper proposes a detection and defense method against unobservable FDIAs in the distributed LFC system.Firstly,the method integrates a bi-directional long short-term memory(Bi LSTM)neural network and an improved whale optimization algorithm(IWOA)into the LFC controller to detect and counteract FDIAs.Secondly,to enable the Bi LSTM neural network to proficiently detect multiple types of FDIAs with utmost precision,the model employs a historical MG dataset comprising the frequency and power variances.Finally,the IWOA is utilized to optimize the proportional-integral-derivative(PID)controller parameters to counteract the negative impacts of FDIAs.The proposed detection and defense method is validated by building the distributed LFC system in Simulink.展开更多
Self-powered photodetectors can convert light into electrical signals without external power input and are widely used in applications such as imaging,sensing,communication,and security.The most popular approach for c...Self-powered photodetectors can convert light into electrical signals without external power input and are widely used in applications such as imaging,sensing,communication,and security.The most popular approach for constructing a self-powered photodetector is typically based on the fabrication of an asymmetric metal-semiconductor(MS)contact;however,this technique is seriously limited by the Fermi-level pinning effect.Here,we report a room-temperature photodetector based on multi-layer MoS_(2) sandwiched between two separated asymmetric graphene contacts.Our photodetector was driven by the built-in electric field generated by a van der Waals(vd W)contact instead of the traditional MS contact.Operating under zero-bias voltage,the highest photoresponsivity of 0.63 AW^(-1) and a specific detectivity of 7.71×10^(12) Jones were achieved at a wavelength of 450 nm with 0.08μW cm^(-2) incident power intensity.Compared with devices using symmetric contacts,a high ON/OFF current ratio of approximately 1520 and a fast response time on the order of microseconds were also observed in our asymmetric graphene contact device.Our experimental results may open a novel way toward the realization of vd W contacts for the fabrication of selfpowered photodetectors.展开更多
The paper presents a study of networked control systems(NCSs)that are subjected to periodic denial-of-service(DoS)attacks of varying intensity.The use of appropriate Lyapunov-Krasovskii functionals(LKFs)help to reduce...The paper presents a study of networked control systems(NCSs)that are subjected to periodic denial-of-service(DoS)attacks of varying intensity.The use of appropriate Lyapunov-Krasovskii functionals(LKFs)help to reduce the constraints of the basic conditions and lower the conservatism of the criteria.An optimization problem with constraints is formulated to select the trigger threshold,which is solved using the gradient descent algorithm(GDA)to improve resource utilization.An intelligent secure event-triggered controller(ISETC)is designed to ensure the safe operation of the system under DoS attacks.The approach is validated through experiments with an autonomous ground vehicle(AGV)system based on the Simulink platform.The proposed method offers the potential for developing effective defense mechanisms against DoS attacks in NCSs.展开更多
基金supported by the National Key Research and Development Project of China(2020YFA0714301)the National Natural Science Foundation of China(61833005)。
文摘Dear Editor,This letter deals with the set stabilization of stochastic Boolean control networks(SBCNs)by the pinning control strategy,which is to realize the full control for systems by imposing control inputs on a fraction of agents.
文摘Dear Editor,This letter considers the finite-time stability(FTS)problem of generalized impulsive stochastic nonlinear systems(ISNS).By employing the stochastic Lyapunov and impulsive control approach,some novel criteria on FTS are presented,where both situations of stabilizing and destabilizing impulses are considered.Furthermore,new impulse-dependent estimation strategies of stochastic settling time(SST)are proposed.
文摘Dear Editor,This letter studies the problem of sliding mode control(SMC)design for recurrent neural networks(RNNs)with impulsive disturbances and time-varying transmission delays.To this end,an appropriate integral sliding surface function and SMC law are adopted for use under impulsive disturbances and time-varying delays.
基金supported in part by the National Natural Science Foundation of China(62173087)the Fundamental Research Funds for the Central Universitiesthe Alexander von Humboldt Foundation of Germany。
文摘Dear Editor,Over the past decades,cooperative control and distributed optimization have gained significant research attention due to their broad applications such as signal processing,robotics,and social networks[1],[2].As a fundamental component of distributed control and optimization,the issue of average consensus has become a recurring topic of interest[3],[4].
基金supported financially by the National Key Research and Development Program of China(Grant No.2019YFA0307900)the National Natural Science Foundation of China(Grant No.51972028)the China Postdoctoral Science Foundation(Grant No.2020M680375).
文摘Ferroelectric materials possessing exceptional piezoelectric attributes have garnered widespread utilization in various applications.Solid solution systems improve piezoelectric properties through multiphase mixing,but the methodologies for effective design remain wanting.Based on the Landau–Devonshire theory,we propose a theoretical design method.Binary materials with morphotropic phase boundary(MPB)compositions are added with new elements to increase the free energy of the original stabilized phase and lower the energy barrier(EB).Flatter EBsand higher piezoelectric coefficients are found at the phase boundaries of the ternary system.By calculating the phase diagram,piezoelectric coefficient,dielectric constant,polarization,and EBs,we reveal the origin of the highest piezoelectric coefficient at the phase boundaries.This study underscores the importance of the EBs for polarization rotation in characterizing piezoelectric properties and proposes a theoretical design method for exploring materials with high piezoelectric coefficients.
基金supported in part by the National Natural Science Foundation of China(No.61973078)in part by the Natural Science Foundation of Jiangsu Province of China(No.BK20231416)in part by the Zhishan Youth Scholar Program from Southeast University(No.2242022R40042)。
文摘In the realm of microgrid(MG),the distributed load frequency control(LFC)system has proven to be highly susceptible to the negative effects of false data injection attacks(FDIAs).Considering the significant responsibility of the distributed LFC system for maintaining frequency stability within the MG,this paper proposes a detection and defense method against unobservable FDIAs in the distributed LFC system.Firstly,the method integrates a bi-directional long short-term memory(Bi LSTM)neural network and an improved whale optimization algorithm(IWOA)into the LFC controller to detect and counteract FDIAs.Secondly,to enable the Bi LSTM neural network to proficiently detect multiple types of FDIAs with utmost precision,the model employs a historical MG dataset comprising the frequency and power variances.Finally,the IWOA is utilized to optimize the proportional-integral-derivative(PID)controller parameters to counteract the negative impacts of FDIAs.The proposed detection and defense method is validated by building the distributed LFC system in Simulink.
基金supported by the National Natural Science Foundation of China(Grant No.61971108)Science and Technology Foundation of Sichuan Province(Grant No.2021YFS0311)。
文摘Self-powered photodetectors can convert light into electrical signals without external power input and are widely used in applications such as imaging,sensing,communication,and security.The most popular approach for constructing a self-powered photodetector is typically based on the fabrication of an asymmetric metal-semiconductor(MS)contact;however,this technique is seriously limited by the Fermi-level pinning effect.Here,we report a room-temperature photodetector based on multi-layer MoS_(2) sandwiched between two separated asymmetric graphene contacts.Our photodetector was driven by the built-in electric field generated by a van der Waals(vd W)contact instead of the traditional MS contact.Operating under zero-bias voltage,the highest photoresponsivity of 0.63 AW^(-1) and a specific detectivity of 7.71×10^(12) Jones were achieved at a wavelength of 450 nm with 0.08μW cm^(-2) incident power intensity.Compared with devices using symmetric contacts,a high ON/OFF current ratio of approximately 1520 and a fast response time on the order of microseconds were also observed in our asymmetric graphene contact device.Our experimental results may open a novel way toward the realization of vd W contacts for the fabrication of selfpowered photodetectors.
基金supported by the National Key Research and Development Plan(Grant No.2020YFB2009503)the National Natural Science Foundation of China under Grant(Nos.61703060,61802036,61701048,61873305,U20B2046,62272119,62072130)+4 种基金the Sichuan Science and Technology Program under Grant No.2021YJ0106the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515010450,2021A1515012307)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)Guangdong Higher Education Innovation Group(No.2020KCXTD007),Guangzhou Higher Education Innovation Group(No.202032854)Consulting project of the Chinese Academy of Engineering(2022-JB-04-05).
文摘The paper presents a study of networked control systems(NCSs)that are subjected to periodic denial-of-service(DoS)attacks of varying intensity.The use of appropriate Lyapunov-Krasovskii functionals(LKFs)help to reduce the constraints of the basic conditions and lower the conservatism of the criteria.An optimization problem with constraints is formulated to select the trigger threshold,which is solved using the gradient descent algorithm(GDA)to improve resource utilization.An intelligent secure event-triggered controller(ISETC)is designed to ensure the safe operation of the system under DoS attacks.The approach is validated through experiments with an autonomous ground vehicle(AGV)system based on the Simulink platform.The proposed method offers the potential for developing effective defense mechanisms against DoS attacks in NCSs.