In this article, a synchronization problem for master-slave Markovian switching complex dynamical networks with time-varying delays in nonlinear function via sliding mode control is investigated. On the basis of the a...In this article, a synchronization problem for master-slave Markovian switching complex dynamical networks with time-varying delays in nonlinear function via sliding mode control is investigated. On the basis of the appropriate Lyapunov-Krasovskii functional, introducing some free weighting matrices, new synchronization criteria are derived in terms of linear matrix inequalities （LMIs）. Then, an integral sliding surface is designed to guarantee synchronization of master-slave Markovian switching complex dynamical networks, and the suitable controller is synthesized to ensure that the trajectory of the closed-loop error system can be driven onto the prescribed sliding mode surface. By using Dynkin＇s formula, we established the stochastic stablity of master-slave system. Finally, numerical example is provided to demonstrate the effectiveness of the obtained theoretical results.展开更多
In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting spee...In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting speed,cutting angle,and rotational speed)in order to explore their influences on cutting performance.The results indicate that the thrust,torque,vibration velocity,and roughness all increased continuously with increase of the propulsion speed and cutting depth.At the same time,the specific energy consumption was found to decrease continuously.As the rotational speed was increased,the thrust increased at first and then decreased.In contrast,the torque and roughness continuously decreased,and the specific energy consumption and vibration speed continuously increased.When the cutting angle was increased,the thrust remained unchanged.However,the torque,specific energy consumption,and vibration speed all decreased continuously,and the roughness increased continuously.The temperature of the surface of the cutting tool was found to be relatively uniformly distributed during the rock-breaking process;the highest temperatures generated were in the range of 200-300℃.As the propulsion speed,cutting depth,and cutting angle were increased,the proportion of tensile fractures produced appeared to increase and the proportion of shear fractures decreased.As the rotational speed was increased,the proportion of tensile fractures decreased and the proportion of shear fractures increased.The results could provide useful information on the rock-breaking behavior involved and can be used to offer technical support for engineers using master-slave follow-up disc cutters in the field.展开更多
This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling m...This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling matrices to be symmetric or irreducible.We have the advantages of using adaptive control method to reduce control gain and pinning control technology to reduce cost.By con-structing Lyapunov function,some sufficient synchronization criteria are established.Finally,numerical examples are employed to illustrate the effectiveness of the proposed approach.展开更多
Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we ...Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion.In our proposal,the CPT state and the CPA state are treated as the on state and the off state,respectively.Consequently,the efficiency of this all-optical switch can reach the maximum value of 1.With the introduction of an incoherent pump field,the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state.The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field.展开更多
Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has...Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.展开更多
Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for ...Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for pervasive computing that suitable for general PC, mobile device such as smart phones or PADs to participants in the working of mining and verification, in which we separated traditional blockchain model in 2 layer defined as master node layer and a series of slavery agents layer, then we proposed 2 approaches for partially computing model(PCM) and non-computing of model(NCM) in the MSB blockchain, Finally large amounts of simulations manifest the proposed master-slave blockchain scheme is feasible, extendible and suitable for pervasive computing especially in the 5 G generation environment, and can apply in the DRM-related applications.展开更多
This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such ...This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master-slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numer- ical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master-slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization con- trol strategy. This synchronization control strategy proves the synchronization＇s feasibility and controllability for com- plicated motions generated by master-slave manipulators.展开更多
The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple li...The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple linear state feedback controller is designed to synchronize the master chaotic system and the slave chaotic systems with a time- varying communication topology connection. The exponential stability of the closed-loop networked synchronization error system is guaranteed by applying Lyapunov stability theory. The derived novel criteria are in the form of linear matrix inequalities （LMIs）, which are easy to examine and tremendously reduce the computation burden from the feedback matrices. This paper provides an alternative networked secure communication scheme which can be extended conveniently. An illustrative example is given to demonstrate the effectiveness of the proposed networked synchronization method.展开更多
As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the...As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the leading cause.Hence,the solution may rest with the synchronization of those heating processes in MCHR system.This paper proposes a’Master-Slave’generalized predictive synchronization control(MS-GPSC)method with’Mr.Slowest’strategy for preheating stage of MCHR system.The core of the proposed method is choosing the heating process with slowest dynamics as the’Master’to track the setpoint,while the other heating processes are treated as‘Slaves’tracking the output of’Master’.This proposed method is shown to have the good ability of temperature synchronization.The corresponding analysis is conducted on parameters tuning and stability,simulations and experiments show the strategy is effective.展开更多
A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelit...A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelity and controllability experiments demonstrate feasibility of the con-trol system.展开更多
The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inhere...The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inherent limitation,that is,the spreading angle cannot be controlled independently,rather by the jet volume flow rate and internal geometry.Accordingly,two types of fluidic oscillators based on the master-slave design are developed in current study to decouple this correlation.In both designs,the master layer inherits the similar oscillation mechanisms of a sweeping jet,and the slave layer resembles a steady jet channel.The difference between the two designs is that Design A has a short diverging exit in the slave layer,but Design B adds a long interaction chamber in the exit channel to intensify flow instability.The external flow fields and governing oscillation properties of these two designs are experimentally explored with time-resolved Particle Image Velocimetry(PIV),while the internal flow dynamics and driving oscillation mechanisms are numerically investigated.By fixing the total volume flow rate,the jet spreading angle of Design A can be increased smoothly from 0°to above 100°by increasing the proportion of master layer’s flow rate from 0 to 100%.For Design B,the control authority of the master layer is significantly enhanced by adding the interaction chamber in the slave layer.In addition,the added chamber causes notable jet oscillation even when the master layer has none input.展开更多
This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed tim...This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed time delays. Using an appropriate Lyapunov-Krasovskii functional, some delay-dependent sufficient conditions and an adaptation law including the master-slave parame- ters are established for designing a delayed synchronization law in terms of linear matrix inequalities（LMIs）. The time-varying controller guarantees the H ∞ synchronization of the two coupled master and slave systems regardless of their initial states. Particularly, it is shown that the synchronization speed can be controlled by adjusting the updated gain of the synchronization signal. Two numerical examples are given to demonstrate the effectiveness of the method.展开更多
Welding seam tracking precision was decreased due to human hand tremor during the master-slave welding teleoperation. To solve this problem, a master-slave robot remote welding system was built, the system consisted o...Welding seam tracking precision was decreased due to human hand tremor during the master-slave welding teleoperation. To solve this problem, a master-slave robot remote welding system was built, the system consisted of a master manipulator with six degree of freedom （ DOF ） , an industrial computer control system and a slave Motoman HP3 J robot, and human hand tremor and digital filtering were discussed. An optimal digital filter was designed to clean human tremor signal for improving the welding seam tracking precision. The experimental results show that the digital filter suppresses the operator＇ s tremor signal.展开更多
Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON an...Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master slave RS 422/485 protocol. This design adopts LON as the trunk, master slave RS 422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance cost ratio.展开更多
This study aims to address the feasibility of planned islanding operation and to investigate the effect of unplanned islanding using the master-slave islanding method for controlling the distributed generation units d...This study aims to address the feasibility of planned islanding operation and to investigate the effect of unplanned islanding using the master-slave islanding method for controlling the distributed generation units during grid-connected and islanding operation. Neplan desktop power simulation tool was used for the modelling and simulation of a realistic MV network with four different distributed generation technologies (diesel, gas, hydro and wind) along with their excitation and governor control systems, while an exponential model was used to represent the loads in the network. The dynamic and steady state behavior of the four distributed generation technologies were investigated during grid-connected operation and two transition modes to the islanding situation, planned and unplanned. The obtained results that validated through various case studies have shown that a suitable planned islanding transition could provide support to critical loads at the event of electricity utility outages.展开更多
Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely us...Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely used for artificial spiking synapses due to their relatively poor memrisitve performance.Here,for the first time,we present an organic memristor based on an electropolymerized dopamine-based memristive layer.This polydopamine-based memristor demonstrates the improve-ments in key performance,including a low threshold voltage of 0.3 V,a thin thickness of 16 nm,and a high parasitic capaci-tance of about 1μF·mm^(-2).By leveraging these properties in combination with its stable threshold switching behavior,we con-struct a capacitor-free and low-power artificial spiking neuron capable of outputting the oscillation voltage,whose spiking fre-quency increases with the increase of current stimulation analogous to a biological neuron.The experimental results indicate that our artificial spiking neuron holds potential for applications in neuromorphic computing and systems.展开更多
BACKGROUND Research has consistently demonstrated that patients with major depressive disorder(MDD)exhibit attentional switching dysfunction,and the dual-task paradigm has emerged as a valuable tool for probing cognit...BACKGROUND Research has consistently demonstrated that patients with major depressive disorder(MDD)exhibit attentional switching dysfunction,and the dual-task paradigm has emerged as a valuable tool for probing cognitive deficits.However,the neuroelectrophysiological mechanism underlying this deficit has not been clarified.AIM To investigate the event-related potential(ERP)characteristics of attentional switching dysfunction and further explore the neuroelectrophysiological mechanism of the cognitive processing deficits underlying attentional switching dysfunction in MDD.METHODS The participants included 29 MDD patients and 29 healthy controls(HCs).The ERPs of the participants were measured while they performed the dual-task para digm.The behavioral and ERP N100,P200,P300,and late positive potential(LPP)data were analyzed.RESULTS This study revealed greater accuracy in HCs and slower reaction times(RTs)in MDD patients.Angry facial pictures led to lower accuracy.The results also revealed shorter RTs for happy facial pictures and the longest RTs for the 500-ms stimulus onset asynchrony.With respect to ERP characteristics,happy facial pictures and neutral facial pictures evoked higher amplitudes.The N100,P200,P300,and LPP amplitudes at Pz were the highest.MDD patients had lower P200 mean amplitudes and LPP amplitudes than HCs did.CONCLUSION In conclusion,MDD patients exhibited abnormal ERP characteristics evoked by the dual-task paradigm,which could be the neural correlates of the known abnormalities in attentional switching in patients with MDD.These results provide valuable insights into the understanding of the neural mechanisms of attentional switching function and may guide targeted interventions in patients with MDD.展开更多
文摘In this article, a synchronization problem for master-slave Markovian switching complex dynamical networks with time-varying delays in nonlinear function via sliding mode control is investigated. On the basis of the appropriate Lyapunov-Krasovskii functional, introducing some free weighting matrices, new synchronization criteria are derived in terms of linear matrix inequalities （LMIs）. Then, an integral sliding surface is designed to guarantee synchronization of master-slave Markovian switching complex dynamical networks, and the suitable controller is synthesized to ensure that the trajectory of the closed-loop error system can be driven onto the prescribed sliding mode surface. By using Dynkin＇s formula, we established the stochastic stablity of master-slave system. Finally, numerical example is provided to demonstrate the effectiveness of the obtained theoretical results.
基金study was supported by the National Key Research and Development Program of China(Grant No.2023YFC2907202)the National Natural Science Foundation of China(Grant No.52404116)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240129).
文摘In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting speed,cutting angle,and rotational speed)in order to explore their influences on cutting performance.The results indicate that the thrust,torque,vibration velocity,and roughness all increased continuously with increase of the propulsion speed and cutting depth.At the same time,the specific energy consumption was found to decrease continuously.As the rotational speed was increased,the thrust increased at first and then decreased.In contrast,the torque and roughness continuously decreased,and the specific energy consumption and vibration speed continuously increased.When the cutting angle was increased,the thrust remained unchanged.However,the torque,specific energy consumption,and vibration speed all decreased continuously,and the roughness increased continuously.The temperature of the surface of the cutting tool was found to be relatively uniformly distributed during the rock-breaking process;the highest temperatures generated were in the range of 200-300℃.As the propulsion speed,cutting depth,and cutting angle were increased,the proportion of tensile fractures produced appeared to increase and the proportion of shear fractures decreased.As the rotational speed was increased,the proportion of tensile fractures decreased and the proportion of shear fractures increased.The results could provide useful information on the rock-breaking behavior involved and can be used to offer technical support for engineers using master-slave follow-up disc cutters in the field.
文摘This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling matrices to be symmetric or irreducible.We have the advantages of using adaptive control method to reduce control gain and pinning control technology to reduce cost.By con-structing Lyapunov function,some sufficient synchronization criteria are established.Finally,numerical examples are employed to illustrate the effectiveness of the proposed approach.
基金supported by the National Natural Science Foundation of China(Grants Nos.12304405,12275203,and 12075176)the Natural Science Foundation of Shaanxi Provincial Department of Education(Grant No.23JK0483)+2 种基金the Natural Science Basic Research Program of Shaanxi(Grant Nos.2024JC-YBMS-521 and 2024JC-YBMS-039)the 2022 Shaanxi University Youth Innovation Team Project(Grant No.K20220186)the College Students’Innovative Entrepreneurial Training Plan Program of Shaanxi(Grant No.S202410702178)。
文摘Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion.In our proposal,the CPT state and the CPA state are treated as the on state and the off state,respectively.Consequently,the efficiency of this all-optical switch can reach the maximum value of 1.With the introduction of an incoherent pump field,the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state.The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field.
基金supported by the Natural Science Foundation of Guangdong Province,China (No.2025A1515011654)the National Natural Science Foundation of China (No.22090053)+3 种基金the Fundamental Research Funds for National Universities,China University of Geosciences (Wuhan)support from the program of China Scholarships Council (No.202406410155)Young Elite Scientists Sponsorship Program by CAST-Doctoral Student Special Plansupport from the S&T Special Program of Huzhou (No.2024GZ07)。
文摘Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.
基金supported by the National Key R&D Program of China(2023YFA1406200)the National Natural Science Foundation of China(T2521005,12174144,12474009,12174146,and 124B2059)the Special Construction Project Fund for Shan-dong Province Taishan Scholars.
文摘Multifunctional optical responsive materials have grown increasingly pivotal in addressingthe escalating demands of sensing,detection,and anti-counterfeiting applications[1,2].These materials exhibit distinct visible optical variations upon exposure to external stimuli,such as pressure,temperature,light,solvents,pH fluctuations,or mechanical force.Fluorescent sensing and anti-counterfeiting technologies leveraging these optical responses have emerged as highly promising solutions.
基金supported by the National Natural Science Foundation of China under Grant 61272519the Research Funds of Blockchain Joint Lab between BUPT and BCTthe joint Blockchain and Security Lab between BUPT and CAPSTONE
文摘Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for pervasive computing that suitable for general PC, mobile device such as smart phones or PADs to participants in the working of mining and verification, in which we separated traditional blockchain model in 2 layer defined as master node layer and a series of slavery agents layer, then we proposed 2 approaches for partially computing model(PCM) and non-computing of model(NCM) in the MSB blockchain, Finally large amounts of simulations manifest the proposed master-slave blockchain scheme is feasible, extendible and suitable for pervasive computing especially in the 5 G generation environment, and can apply in the DRM-related applications.
基金supported by the Key Project of Chinese Ministry of Education(108037)the National Natural Science Foundation of China(10402008 and 50535010)
文摘This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master-slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numer- ical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master-slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization con- trol strategy. This synchronization control strategy proves the synchronization＇s feasibility and controllability for com- plicated motions generated by master-slave manipulators.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60904046, 60972164, 60974071, and 60804006)the Special Fund for Basic Scientific Research of Central Colleges, Northeastern University, China (Grant No. 090604005)+2 种基金the Science and Technology Program of Shenyang (Grant No. F11-264-1-70)the Program for Liaoning Excellent Talents in University (Grant No. LJQ2011137)the Program for Liaoning Innovative Research Team in University (Grant No. LT2011019)
文摘The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple linear state feedback controller is designed to synchronize the master chaotic system and the slave chaotic systems with a time- varying communication topology connection. The exponential stability of the closed-loop networked synchronization error system is guaranteed by applying Lyapunov stability theory. The derived novel criteria are in the form of linear matrix inequalities （LMIs）, which are easy to examine and tremendously reduce the computation burden from the feedback matrices. This paper provides an alternative networked secure communication scheme which can be extended conveniently. An illustrative example is given to demonstrate the effectiveness of the proposed networked synchronization method.
基金supported in part by National Natural Science Foundation of China(62203127)Basic and Applied Basic Research Project of Guangzhou City(2023A04J1712)+1 种基金The Foshan-HKUST Projects Program(FSUST19-FYTRI01)GDAS’Project of Science and Technology Development(2020GDASYL-20200202001).
文摘As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the leading cause.Hence,the solution may rest with the synchronization of those heating processes in MCHR system.This paper proposes a’Master-Slave’generalized predictive synchronization control(MS-GPSC)method with’Mr.Slowest’strategy for preheating stage of MCHR system.The core of the proposed method is choosing the heating process with slowest dynamics as the’Master’to track the setpoint,while the other heating processes are treated as‘Slaves’tracking the output of’Master’.This proposed method is shown to have the good ability of temperature synchronization.The corresponding analysis is conducted on parameters tuning and stability,simulations and experiments show the strategy is effective.
文摘A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelity and controllability experiments demonstrate feasibility of the con-trol system.
基金financial support from the National Natural Science Foundation of China(Nos.12072196 and 11702172)Science and Technology Commission of Shanghai Municipality(No.19JC1412900)+1 种基金Aeronautics Power Foundation(No.6141B09050393)Key Laboratory of Aerodynamic Noise Control(No.ANCL20190106)extended to this study。
文摘The fluidic oscillator is an instrument that can continuously generate a spatially sweeping jet entirely based on its internal geometry without any moving parts.However,the traditional fluidic oscillator has an inherent limitation,that is,the spreading angle cannot be controlled independently,rather by the jet volume flow rate and internal geometry.Accordingly,two types of fluidic oscillators based on the master-slave design are developed in current study to decouple this correlation.In both designs,the master layer inherits the similar oscillation mechanisms of a sweeping jet,and the slave layer resembles a steady jet channel.The difference between the two designs is that Design A has a short diverging exit in the slave layer,but Design B adds a long interaction chamber in the exit channel to intensify flow instability.The external flow fields and governing oscillation properties of these two designs are experimentally explored with time-resolved Particle Image Velocimetry(PIV),while the internal flow dynamics and driving oscillation mechanisms are numerically investigated.By fixing the total volume flow rate,the jet spreading angle of Design A can be increased smoothly from 0°to above 100°by increasing the proportion of master layer’s flow rate from 0 to 100%.For Design B,the control authority of the master layer is significantly enhanced by adding the interaction chamber in the slave layer.In addition,the added chamber causes notable jet oscillation even when the master layer has none input.
文摘This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed time delays. Using an appropriate Lyapunov-Krasovskii functional, some delay-dependent sufficient conditions and an adaptation law including the master-slave parame- ters are established for designing a delayed synchronization law in terms of linear matrix inequalities（LMIs）. The time-varying controller guarantees the H ∞ synchronization of the two coupled master and slave systems regardless of their initial states. Particularly, it is shown that the synchronization speed can be controlled by adjusting the updated gain of the synchronization signal. Two numerical examples are given to demonstrate the effectiveness of the method.
基金This research is supported by National Natural Science Foundation of China （No. 50905043）.
文摘Welding seam tracking precision was decreased due to human hand tremor during the master-slave welding teleoperation. To solve this problem, a master-slave robot remote welding system was built, the system consisted of a master manipulator with six degree of freedom （ DOF ） , an industrial computer control system and a slave Motoman HP3 J robot, and human hand tremor and digital filtering were discussed. An optimal digital filter was designed to clean human tremor signal for improving the welding seam tracking precision. The experimental results show that the digital filter suppresses the operator＇ s tremor signal.
文摘Aiming at the weaknesses of LON bus, combining the coexistence of fieldbus and DCS (Distribu ted Control Systems) in control networks, the authors introduce a hierarchical hybrid control network design based on LON and master slave RS 422/485 protocol. This design adopts LON as the trunk, master slave RS 422/485 control networks are connected to LON as special subnets by dedicated gateways. It is an implementation method for isomerous control network integration. Data management is ranked according to real time requirements for different network data. The core components, such as control network nodes, router and gateway, are detailed in the paper. The design utilizes both communication advantage of LonWorks technology and the more powerful control ability of universal MCUs or PLCs, thus it greatly increases system response speed and performance cost ratio.
文摘This study aims to address the feasibility of planned islanding operation and to investigate the effect of unplanned islanding using the master-slave islanding method for controlling the distributed generation units during grid-connected and islanding operation. Neplan desktop power simulation tool was used for the modelling and simulation of a realistic MV network with four different distributed generation technologies (diesel, gas, hydro and wind) along with their excitation and governor control systems, while an exponential model was used to represent the loads in the network. The dynamic and steady state behavior of the four distributed generation technologies were investigated during grid-connected operation and two transition modes to the islanding situation, planned and unplanned. The obtained results that validated through various case studies have shown that a suitable planned islanding transition could provide support to critical loads at the event of electricity utility outages.
基金support from the Beijing Natural Science Foundation-Xiaomi Innovation Joint Fund(No.L233009)National Natural Science Foundation of China(NSFC Nos.62422409,62174152,and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020115).
文摘Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely used for artificial spiking synapses due to their relatively poor memrisitve performance.Here,for the first time,we present an organic memristor based on an electropolymerized dopamine-based memristive layer.This polydopamine-based memristor demonstrates the improve-ments in key performance,including a low threshold voltage of 0.3 V,a thin thickness of 16 nm,and a high parasitic capaci-tance of about 1μF·mm^(-2).By leveraging these properties in combination with its stable threshold switching behavior,we con-struct a capacitor-free and low-power artificial spiking neuron capable of outputting the oscillation voltage,whose spiking fre-quency increases with the increase of current stimulation analogous to a biological neuron.The experimental results indicate that our artificial spiking neuron holds potential for applications in neuromorphic computing and systems.
基金Supported by Wuxi Taihu Talent Project,No.WXTTP 2021the General Scientific Research Program of Wuxi Municipal Health Commission,No.M202447.
文摘BACKGROUND Research has consistently demonstrated that patients with major depressive disorder(MDD)exhibit attentional switching dysfunction,and the dual-task paradigm has emerged as a valuable tool for probing cognitive deficits.However,the neuroelectrophysiological mechanism underlying this deficit has not been clarified.AIM To investigate the event-related potential(ERP)characteristics of attentional switching dysfunction and further explore the neuroelectrophysiological mechanism of the cognitive processing deficits underlying attentional switching dysfunction in MDD.METHODS The participants included 29 MDD patients and 29 healthy controls(HCs).The ERPs of the participants were measured while they performed the dual-task para digm.The behavioral and ERP N100,P200,P300,and late positive potential(LPP)data were analyzed.RESULTS This study revealed greater accuracy in HCs and slower reaction times(RTs)in MDD patients.Angry facial pictures led to lower accuracy.The results also revealed shorter RTs for happy facial pictures and the longest RTs for the 500-ms stimulus onset asynchrony.With respect to ERP characteristics,happy facial pictures and neutral facial pictures evoked higher amplitudes.The N100,P200,P300,and LPP amplitudes at Pz were the highest.MDD patients had lower P200 mean amplitudes and LPP amplitudes than HCs did.CONCLUSION In conclusion,MDD patients exhibited abnormal ERP characteristics evoked by the dual-task paradigm,which could be the neural correlates of the known abnormalities in attentional switching in patients with MDD.These results provide valuable insights into the understanding of the neural mechanisms of attentional switching function and may guide targeted interventions in patients with MDD.
