Regulation plays a pivotal role in mitigating the spread of rumors, serving as a vital tool for maintaining social stability and facilitating its evolution. A central challenge lies in establishing an effective regula...Regulation plays a pivotal role in mitigating the spread of rumors, serving as a vital tool for maintaining social stability and facilitating its evolution. A central challenge lies in establishing an effective regulatory framework despite limited resources available for combating rumor propagation. To address this challenge, this paper proposes a dynamic and adaptive regulatory system. First, based on observed regulatory patterns in real-world social networks, the rumor propagation process is divided into two distinct phases: regulation and intervention. Regulatory intensity is introduced as an indicator of user state transitions. Unlike traditional, non-adaptive regulatory models that allocate costs uniformly,the adaptive model facilitates flexible cost distribution through a manageable individual regulatory intensity. Moreover,by introducing adaptive strength, the two cost allocation models are integrated within a unified framework, leading to the development of a dynamic model for rumor suppression. Finally, simulation experiments on Barabási–Albert(BA)networks demonstrate that the adaptive regulatory mechanism significantly reduces both the scope and duration of rumor propagation. Furthermore, when traditional non-adaptive regulatory models show limited effectiveness, the adaptive model effectively curbs rumor propagation by optimizing cost allocation between regulatory and intervention processes, and by adjusting per-unit cost benefit differentials.展开更多
The analysis of structure and dynamics in chaotic systems has long been a significant research direction in nonlinear science.Constructing a reliable chaotic system with rich dynamical characteristics is essential for...The analysis of structure and dynamics in chaotic systems has long been a significant research direction in nonlinear science.Constructing a reliable chaotic system with rich dynamical characteristics is essential for secure communication applications.Existing memristor-based chaotic maps are typically obtained by incorporating discrete mathematical models of memristors into basic chaotic maps.In this study,a simple memristive nonlinear circuit is first designed,from which a memristive oscillator is derived.Subsequently,a memristive map is developed from this oscillator through a linear transformation of the variables.The reliability of the new map is validated through nonlinear dynamic analysis.The results demonstrate that the map exhibits complex nonlinear dynamics under different parameter settings.This finding is beneficial for the construction of memristor maps and the development of image encryption algorithms.展开更多
Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control o...Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control（ARC） are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve＇s dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.展开更多
This paper reviews recent developments in learning-based adaptive optimal output regulation that aims to solve the problem of adaptive and optimal asymptotic tracking with disturbance rejection.The proposed framework ...This paper reviews recent developments in learning-based adaptive optimal output regulation that aims to solve the problem of adaptive and optimal asymptotic tracking with disturbance rejection.The proposed framework aims to bring together two separate topics—output regulation and adaptive dynamic programming—that have been under extensive investigation due to their broad applications in modern control engineering.Under this framework,one can solve optimal output regulation problems of linear,partially linear,nonlinear,and multi-agent systems in a data-driven manner.We will also review some practical applications based on this framework,such as semi-autonomous vehicles,connected and autonomous vehicles,and nonlinear oscillators.展开更多
In this paper,we present an output regulation method for unknown cyber-physical systems(CPSs)under time-delay attacks in both the sensor-to-controller(S-C)channel and the controller-to-actuator(C-A)channel.The propose...In this paper,we present an output regulation method for unknown cyber-physical systems(CPSs)under time-delay attacks in both the sensor-to-controller(S-C)channel and the controller-to-actuator(C-A)channel.The proposed approach is designed using control inputs and tracking errors which are accessible data.Reinforcement learning is leveraged to update the control gains in real time using policy or value iterations.A thorough stability analysis is conducted and it is found that the proposed controller can sustain the convergence and asymptotic stability even when two channels are attacked.Finally,comparison results with a simulated CPS verify the effectiveness of the proposed output regulation method.展开更多
Nonlinear circuits can show multistability when a magnetic flux-dependent memristor(MFDM) or a charge-sensitive memristor(CSM) is incorporated into a one branch circuit,which helps estimate magnetic or electric field ...Nonlinear circuits can show multistability when a magnetic flux-dependent memristor(MFDM) or a charge-sensitive memristor(CSM) is incorporated into a one branch circuit,which helps estimate magnetic or electric field effects.In this paper,two different kinds of memristors are incorporated into two branch circuits composed of a capacitor and a nonlinear resistor,thus a memristive circuit with double memristive channels is designed.The circuit equations are presented,and the dynamics in this oscillator with two memristive terms are discussed.Then,the memristive oscillator is converted into a memristive map by applying linear transformation on the sampled time series for the memristive oscillator.The Hamilton energy function for the memristive oscillator is obtained by using the Helmholtz theorem,and it can be mapped from the field energy of the memristive circuit.An energy function for the dual memristive map is suggested by imposing suitable weights on the discrete energy function.The dynamical behaviors of the new memristive map are investigated,and an adaptive law is proposed to regulate the firing mode in the memristive map.This work will provide a theoretical basis and experimental guidance for oscillator-to-map transformation and discrete map energy calculation.展开更多
Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular...Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular high temperature gas-cooled reactor(MHTGR) is considered as one of the best candidates for SMR-based nuclear power plants. Since its dynamics presents high nonlinearity and parameter uncertainty, it is necessary to develop adaptive power-level control, which is beneficial to safe, stable, and efficient operation of MHTGR and is easy to be implemented. In this paper, based on the physically-based control design approach, an adaptive outputfeedback power-level control is proposed for MHTGRs. This control can guarantee globally bounded closedloop stability and has a simple form. Numerical simulation results show the correctness of the theoretical analysis and satisfactory regulation performance of this control.展开更多
The ion channel in neurons is the basic component of signal transmission in the nervous system.The ion channel has important effects on the potential of neuron release and dynamic behavior in neural networks.Ion chann...The ion channel in neurons is the basic component of signal transmission in the nervous system.The ion channel has important effects on the potential of neuron release and dynamic behavior in neural networks.Ion channels control the flow of ions into and out of the cell membrane to form an ion current,which makes the excitable membrane produce special potential changes and become the basis of nerve and muscle activity.The blockage of ion channels has a significant effect on the dynamics of neurons and networks.Therefore,it is very meaningful to study the influence of ion channels on neuronal dynamics.In this work,a hybrid ion channel is designed by connecting a charge-controlled memristor(CCM)with an inductor in series,and a magnetic flux-controlled memristor(MFCM),capacitor,and nonlinear resistor are connected in parallel with the mixed ion channel to obtain the memristor neural circuit.Furthermore,the oscillator model with a hybrid ion channel and its energy function are calculated,and a map neuron is obtained by linearizing the neuron oscillator model.In addition,an adaptive regulation method is designed to explore the adaptive regulation of energy on the dynamic behaviors of the map neuron.The results show that the dynamics of a map neuron with a hybrid ion channel can be controlled by parameters and external magnetic fields.This study is also used to research synchronization between map neurons and collective behaviors in the map neurons network.展开更多
In response to the limitations of conventional thermal management materials,such as restricted functionality,narrow temperature adaptability,and poor breathability,flexibility,and stretchability,this highlight present...In response to the limitations of conventional thermal management materials,such as restricted functionality,narrow temperature adaptability,and poor breathability,flexibility,and stretchability,this highlight presents a breathable,dual-mode leather-like nanotextile(LNT)with asymmetric pleated photonic microstructures and Janus wettability.This innovative design enables efficient and adaptive personal thermal regulation across a broad temperature range,while significantly improving wearer comfort through optimized moisture management and mechanical compliance.The proposed LNT opens new pathways for developing nextgeneration smart textiles,showing great potential for real-world applications in dynamic and demanding environments.展开更多
This paper addresses the global output feedback regulation problem for a class of uncertain feedforward time-delay nonlinear systems.Unlike to the previous works,the nonlinear functions in the class of systems under c...This paper addresses the global output feedback regulation problem for a class of uncertain feedforward time-delay nonlinear systems.Unlike to the previous works,the nonlinear functions in the class of systems under consideration are dominated by an input-output function multiplied by an unknown parameter and linear unmeasured states.By using only one dynamic gain and an appropriate Lyapunov-Krasovskii functionals,it is shown that the closed-loop system is globally asymptotically stable.Finally,a numerical example is provided to illustrate the effectiveness of the proposed design scheme.展开更多
The paper considers the adaptive regulation for the Hammerstein and Wiener systems with event-triggered observations.The authors adopt a direct approach,i.e.,without identifying the unknown parameters and functions wi...The paper considers the adaptive regulation for the Hammerstein and Wiener systems with event-triggered observations.The authors adopt a direct approach,i.e.,without identifying the unknown parameters and functions within the systems,adaptive regulators are directly designed based on the event-triggered observations on the regulation errors.The adaptive regulators belong to the stochastic approximation algorithms and under moderate assumptions,the authors prove that the adaptive regulators are optimal for both the Hammerstein and Wiener systems in the sense that the squared regulation errors are asymptotically minimized.The authors also testify the theoretical results through simulation studies.展开更多
A Multimedia streams dynamic rate control algorithm based on Fuzzy adaptive PID （MFPID） has been proposed to implement multimedia streams＇ end sending rate on-line self-regulating and smoothing, and to track system...A Multimedia streams dynamic rate control algorithm based on Fuzzy adaptive PID （MFPID） has been proposed to implement multimedia streams＇ end sending rate on-line self-regulating and smoothing, and to track system resources in time, so that it can avoid system＇s regulating oscillation and guarantee system＇s stability. And, some work has been done to analyze adaptive session model of multimedia streams, to implement future available bandwidth estimation of IP network, to achieve PID parameters＇ on-line self-tuning by fuzzy controlling. Simulation validated the theoretical results of MFPID.展开更多
A new method for the direct adaptive regulation of unknown nonlinear dynamical systems is proposed in this paper,paying special attention to the analysis of the model order problem.The method uses a neurofuzzy (NF) mo...A new method for the direct adaptive regulation of unknown nonlinear dynamical systems is proposed in this paper,paying special attention to the analysis of the model order problem.The method uses a neurofuzzy (NF) modeling of the unknown system,which combines fuzzy systems (FSs) with high order neural networks (HONNs).We propose the approximation of the unknown system by a special form of an NF-dynamical system (NFDS),which,however,may assume a smaller number of states than the original unknown model.The omission of states,referred to as a model order problem,is modeled by introducing a disturbance term in the approximating equations.The development is combined with a sensitivity analysis of the closed loop and provides a comprehensive and rigorous analysis of the stability properties.An adaptive modification method,termed ‘parameter hopping’,is incorporated into the weight estimation algorithm so that the existence and boundedness of the control signal are always assured.The applicability and potency of the method are tested by simulations on well known benchmarks such as ‘DC motor’ and ‘Lorenz system’,where it is shown that it performs quite well under a reduced model order assumption.Moreover,the proposed NF approach is shown to outperform simple recurrent high order neural networks (RHONNs).展开更多
This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the ge...This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the genetic algorithm(GA),a system that allows to accurately decide in real time on the light switching pattern that minimizes the traffic waiting time.Equally importantly,the inherent crossroads constraints,namely,the security of their users and the structure thereof,also referred to as the antagonism principle,are considered in the proceeding of this method.The implementation of this model on two crossroads significantly decreases the waiting time and regulates the traffic flow.Therefore,the adaptive control system based on the GA proves efficient compared to the nonadaptive system.展开更多
For the linear deterministic system with unknown orders and coefficients adaptive controlsare given so that the closed-loop system is stabilized and the unknown parameters are consistentlyestimated. Moreover, if the p...For the linear deterministic system with unknown orders and coefficients adaptive controlsare given so that the closed-loop system is stabilized and the unknown parameters are consistentlyestimated. Moreover, if the parameter estimation is ignored, then the system input and outputcan be reduced to zero with an exponential rate.展开更多
Preparing enzyme-like artificial hosts that can undergomulti-stimuli-responsive deformationswhile simultaneously enhancing vip reactivity remains a challenge.Here,a flexible coordination tube 1 based on semirigid fo...Preparing enzyme-like artificial hosts that can undergomulti-stimuli-responsive deformationswhile simultaneously enhancing vip reactivity remains a challenge.Here,a flexible coordination tube 1 based on semirigid four-arm ligands was prepared that could undergo multi-stimuli-responsive deformations,including temperature-driven distortions,vip-tuning deformations(e.g.,distortion,contraction,and expansion),stepwise deformations caused by vip concentrations,specific deformations synergistically induced by vips and temperatures.Moreover,tube 1 could effectively regulate the reactivity of Z-stilbene and E/Z-azoarenes throughmutual induced-fit.Inside the tube,the photoisomerization rate and photoisomerization selectivity of Z-stilbene could be enhanced simultaneously,whereby the expansion of tube 1 and the distortion of Z-stilbene occurred synergistically.For the azoarenes in tube 1,E→Z photoisomerization,Z→E photoisomerization,and Z→E thermal isomerizationwere regulated,where Z→E isomerization tended to be promoted and E→Z isomerization was inhibited because E-isomers matched tube 1 better than Z-isomers.This work provides a useful strategy for synthesizing enzymelike artificial hosts.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62266030 and 61863025)。
文摘Regulation plays a pivotal role in mitigating the spread of rumors, serving as a vital tool for maintaining social stability and facilitating its evolution. A central challenge lies in establishing an effective regulatory framework despite limited resources available for combating rumor propagation. To address this challenge, this paper proposes a dynamic and adaptive regulatory system. First, based on observed regulatory patterns in real-world social networks, the rumor propagation process is divided into two distinct phases: regulation and intervention. Regulatory intensity is introduced as an indicator of user state transitions. Unlike traditional, non-adaptive regulatory models that allocate costs uniformly,the adaptive model facilitates flexible cost distribution through a manageable individual regulatory intensity. Moreover,by introducing adaptive strength, the two cost allocation models are integrated within a unified framework, leading to the development of a dynamic model for rumor suppression. Finally, simulation experiments on Barabási–Albert(BA)networks demonstrate that the adaptive regulatory mechanism significantly reduces both the scope and duration of rumor propagation. Furthermore, when traditional non-adaptive regulatory models show limited effectiveness, the adaptive model effectively curbs rumor propagation by optimizing cost allocation between regulatory and intervention processes, and by adjusting per-unit cost benefit differentials.
基金supported by the Youth Innovation Team of Shaanxi Universities。
文摘The analysis of structure and dynamics in chaotic systems has long been a significant research direction in nonlinear science.Constructing a reliable chaotic system with rich dynamical characteristics is essential for secure communication applications.Existing memristor-based chaotic maps are typically obtained by incorporating discrete mathematical models of memristors into basic chaotic maps.In this study,a simple memristive nonlinear circuit is first designed,from which a memristive oscillator is derived.Subsequently,a memristive map is developed from this oscillator through a linear transformation of the variables.The reliability of the new map is validated through nonlinear dynamic analysis.The results demonstrate that the map exhibits complex nonlinear dynamics under different parameter settings.This finding is beneficial for the construction of memristor maps and the development of image encryption algorithms.
基金Supported by National Natural Science Funds of China(Grant No.51275451)National Basic Research Program of China(973 Program,Grant No.2013CB035404)+1 种基金Science Fund for Creative Research Groups of National Natural Science Foundation of China(Grant No.51221004)National Hi-tech Research and Development Program of China(863 Program,Grant No.2013AA040203)
文摘Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control（ARC） are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve＇s dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.
文摘This paper reviews recent developments in learning-based adaptive optimal output regulation that aims to solve the problem of adaptive and optimal asymptotic tracking with disturbance rejection.The proposed framework aims to bring together two separate topics—output regulation and adaptive dynamic programming—that have been under extensive investigation due to their broad applications in modern control engineering.Under this framework,one can solve optimal output regulation problems of linear,partially linear,nonlinear,and multi-agent systems in a data-driven manner.We will also review some practical applications based on this framework,such as semi-autonomous vehicles,connected and autonomous vehicles,and nonlinear oscillators.
基金the National Natural Science Foundation of China(Nos.61973277,62073292)the Zhejiang Provincial Natural Science Foundation of China(No.LR20F030004).
文摘In this paper,we present an output regulation method for unknown cyber-physical systems(CPSs)under time-delay attacks in both the sensor-to-controller(S-C)channel and the controller-to-actuator(C-A)channel.The proposed approach is designed using control inputs and tracking errors which are accessible data.Reinforcement learning is leveraged to update the control gains in real time using policy or value iterations.A thorough stability analysis is conducted and it is found that the proposed controller can sustain the convergence and asymptotic stability even when two channels are attacked.Finally,comparison results with a simulated CPS verify the effectiveness of the proposed output regulation method.
基金supported by the National Science Foundation of China under Grant No. 12072139。
文摘Nonlinear circuits can show multistability when a magnetic flux-dependent memristor(MFDM) or a charge-sensitive memristor(CSM) is incorporated into a one branch circuit,which helps estimate magnetic or electric field effects.In this paper,two different kinds of memristors are incorporated into two branch circuits composed of a capacitor and a nonlinear resistor,thus a memristive circuit with double memristive channels is designed.The circuit equations are presented,and the dynamics in this oscillator with two memristive terms are discussed.Then,the memristive oscillator is converted into a memristive map by applying linear transformation on the sampled time series for the memristive oscillator.The Hamilton energy function for the memristive oscillator is obtained by using the Helmholtz theorem,and it can be mapped from the field energy of the memristive circuit.An energy function for the dual memristive map is suggested by imposing suitable weights on the discrete energy function.The dynamical behaviors of the new memristive map are investigated,and an adaptive law is proposed to regulate the firing mode in the memristive map.This work will provide a theoretical basis and experimental guidance for oscillator-to-map transformation and discrete map energy calculation.
文摘Small modular reactors(SMRs) are beneficial in providing electricity power safely and viable for specific applications such as seawater desalination and heat production. Due to its inherent safety feature, the modular high temperature gas-cooled reactor(MHTGR) is considered as one of the best candidates for SMR-based nuclear power plants. Since its dynamics presents high nonlinearity and parameter uncertainty, it is necessary to develop adaptive power-level control, which is beneficial to safe, stable, and efficient operation of MHTGR and is easy to be implemented. In this paper, based on the physically-based control design approach, an adaptive outputfeedback power-level control is proposed for MHTGRs. This control can guarantee globally bounded closedloop stability and has a simple form. Numerical simulation results show the correctness of the theoretical analysis and satisfactory regulation performance of this control.
基金supported by the National Science Basic Research Program of Shaanxi(Grant No.2023-JC-QN-0087)。
文摘The ion channel in neurons is the basic component of signal transmission in the nervous system.The ion channel has important effects on the potential of neuron release and dynamic behavior in neural networks.Ion channels control the flow of ions into and out of the cell membrane to form an ion current,which makes the excitable membrane produce special potential changes and become the basis of nerve and muscle activity.The blockage of ion channels has a significant effect on the dynamics of neurons and networks.Therefore,it is very meaningful to study the influence of ion channels on neuronal dynamics.In this work,a hybrid ion channel is designed by connecting a charge-controlled memristor(CCM)with an inductor in series,and a magnetic flux-controlled memristor(MFCM),capacitor,and nonlinear resistor are connected in parallel with the mixed ion channel to obtain the memristor neural circuit.Furthermore,the oscillator model with a hybrid ion channel and its energy function are calculated,and a map neuron is obtained by linearizing the neuron oscillator model.In addition,an adaptive regulation method is designed to explore the adaptive regulation of energy on the dynamic behaviors of the map neuron.The results show that the dynamics of a map neuron with a hybrid ion channel can be controlled by parameters and external magnetic fields.This study is also used to research synchronization between map neurons and collective behaviors in the map neurons network.
文摘In response to the limitations of conventional thermal management materials,such as restricted functionality,narrow temperature adaptability,and poor breathability,flexibility,and stretchability,this highlight presents a breathable,dual-mode leather-like nanotextile(LNT)with asymmetric pleated photonic microstructures and Janus wettability.This innovative design enables efficient and adaptive personal thermal regulation across a broad temperature range,while significantly improving wearer comfort through optimized moisture management and mechanical compliance.The proposed LNT opens new pathways for developing nextgeneration smart textiles,showing great potential for real-world applications in dynamic and demanding environments.
文摘This paper addresses the global output feedback regulation problem for a class of uncertain feedforward time-delay nonlinear systems.Unlike to the previous works,the nonlinear functions in the class of systems under consideration are dominated by an input-output function multiplied by an unknown parameter and linear unmeasured states.By using only one dynamic gain and an appropriate Lyapunov-Krasovskii functionals,it is shown that the closed-loop system is globally asymptotically stable.Finally,a numerical example is provided to illustrate the effectiveness of the proposed design scheme.
基金supported by the National Key Research and Development Program of China under Grant No.2018YFA0703800the Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research under Grant No.YSBR-008the Strategic Priority Research Program of CAS under Grant No.XDA27000000。
文摘The paper considers the adaptive regulation for the Hammerstein and Wiener systems with event-triggered observations.The authors adopt a direct approach,i.e.,without identifying the unknown parameters and functions within the systems,adaptive regulators are directly designed based on the event-triggered observations on the regulation errors.The adaptive regulators belong to the stochastic approximation algorithms and under moderate assumptions,the authors prove that the adaptive regulators are optimal for both the Hammerstein and Wiener systems in the sense that the squared regulation errors are asymptotically minimized.The authors also testify the theoretical results through simulation studies.
基金This workis supported by the Chinese High Technology Development Project"863"(2003AA121560) .
文摘A Multimedia streams dynamic rate control algorithm based on Fuzzy adaptive PID （MFPID） has been proposed to implement multimedia streams＇ end sending rate on-line self-regulating and smoothing, and to track system resources in time, so that it can avoid system＇s regulating oscillation and guarantee system＇s stability. And, some work has been done to analyze adaptive session model of multimedia streams, to implement future available bandwidth estimation of IP network, to achieve PID parameters＇ on-line self-tuning by fuzzy controlling. Simulation validated the theoretical results of MFPID.
文摘A new method for the direct adaptive regulation of unknown nonlinear dynamical systems is proposed in this paper,paying special attention to the analysis of the model order problem.The method uses a neurofuzzy (NF) modeling of the unknown system,which combines fuzzy systems (FSs) with high order neural networks (HONNs).We propose the approximation of the unknown system by a special form of an NF-dynamical system (NFDS),which,however,may assume a smaller number of states than the original unknown model.The omission of states,referred to as a model order problem,is modeled by introducing a disturbance term in the approximating equations.The development is combined with a sensitivity analysis of the closed loop and provides a comprehensive and rigorous analysis of the stability properties.An adaptive modification method,termed ‘parameter hopping’,is incorporated into the weight estimation algorithm so that the existence and boundedness of the control signal are always assured.The applicability and potency of the method are tested by simulations on well known benchmarks such as ‘DC motor’ and ‘Lorenz system’,where it is shown that it performs quite well under a reduced model order assumption.Moreover,the proposed NF approach is shown to outperform simple recurrent high order neural networks (RHONNs).
文摘This paper addresses the issue of managing the traffic flow at traffic-light controlled junctions adopting a mixed,nonlinear programming model.More precisely,we adopt an adaptive,acyclic control system based on the genetic algorithm(GA),a system that allows to accurately decide in real time on the light switching pattern that minimizes the traffic waiting time.Equally importantly,the inherent crossroads constraints,namely,the security of their users and the structure thereof,also referred to as the antagonism principle,are considered in the proceeding of this method.The implementation of this model on two crossroads significantly decreases the waiting time and regulates the traffic flow.Therefore,the adaptive control system based on the GA proves efficient compared to the nonadaptive system.
基金This project is supported by the National Natural Science Foundation of China
文摘For the linear deterministic system with unknown orders and coefficients adaptive controlsare given so that the closed-loop system is stabilized and the unknown parameters are consistentlyestimated. Moreover, if the parameter estimation is ignored, then the system input and outputcan be reduced to zero with an exponential rate.
基金supported by the National Key Research and Development Program of China(grant nos.2021YFA1500400 and 2018YFA0704500)the National Natural Science Foundation of China(grant no.22471267)+1 种基金the Natural Science Foundation of Fujian Province,China(grant no.2023J06046)the Selfdeployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(grant no.CXZX-2022-GH06).
文摘Preparing enzyme-like artificial hosts that can undergomulti-stimuli-responsive deformationswhile simultaneously enhancing vip reactivity remains a challenge.Here,a flexible coordination tube 1 based on semirigid four-arm ligands was prepared that could undergo multi-stimuli-responsive deformations,including temperature-driven distortions,vip-tuning deformations(e.g.,distortion,contraction,and expansion),stepwise deformations caused by vip concentrations,specific deformations synergistically induced by vips and temperatures.Moreover,tube 1 could effectively regulate the reactivity of Z-stilbene and E/Z-azoarenes throughmutual induced-fit.Inside the tube,the photoisomerization rate and photoisomerization selectivity of Z-stilbene could be enhanced simultaneously,whereby the expansion of tube 1 and the distortion of Z-stilbene occurred synergistically.For the azoarenes in tube 1,E→Z photoisomerization,Z→E photoisomerization,and Z→E thermal isomerizationwere regulated,where Z→E isomerization tended to be promoted and E→Z isomerization was inhibited because E-isomers matched tube 1 better than Z-isomers.This work provides a useful strategy for synthesizing enzymelike artificial hosts.
