In this paper, we incorporate new parameters into a cellular automaton traffic flow model proposed in our previous paper [Jin et al. 2010 J. Stat. Mech. 2010 P03018]. Through these parameters, we adjust the anticipate...In this paper, we incorporate new parameters into a cellular automaton traffic flow model proposed in our previous paper [Jin et al. 2010 J. Stat. Mech. 2010 P03018]. Through these parameters, we adjust the anticipated velocity and the acceleration threshold separately. It turns out that the flow rate of synchronized flow mainly changes with the anticipated velocity, and the F →S phase transition feature mainly changes with the acceleration threshold. Therefore, we conclude that the acceleration threshold is the major factor affecting the F → S phase transition.展开更多
Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as ...Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as free flow and wide moving jam states in the systems having relatively small values of the bottleneck strength parameter. In addition to the two phases, locally congested phaseappears as the strength becomes prominent. Jam formation occurs with the similar mechanism to the boomerang effect as well as the pinch one in it. Wide scattering of the flow-density relation in fundamental diagram is found in the congested phase.展开更多
The brain neural system is often disturbed by electromagnetic and noise environments, and research on dynamic response of its interaction has received extensive attention. This paper investigates electrical activity o...The brain neural system is often disturbed by electromagnetic and noise environments, and research on dynamic response of its interaction has received extensive attention. This paper investigates electrical activity of Morris-Lecar neural systems exposed to sinusoidal induced electric field(IEF) with random phase generated by electromagnetic effect. By introducing a membrane depolarization model under the effect of random IEF, transition state of firing patterns, including mixed-mode oscillations(MMOs) with layered inter-spike intervals(ISI) and intermittency with a power law distribution in probability density function of ISI, is obtained in a single neuron. Considering the synergistic effects of frequency and noise, coherence resonance is performed by phase noise of IEF under certain parameter conditions. For the neural network without any internal coupling, we demonstrate that synchronous oscillations can be induced by IEF coupling, and suppression of synchronous spiking is achieved effectively by phase noise of IEF. Results of the study enrich the dynamical response to electromagnetic induction and provide insights into mechanisms of noise affecting information coding and transmission in neural systems.展开更多
In this work, we study the collective dynamics of phase oscillators in a mobile ad hoc network whose topology changes dynamically. As the network size or the communication radius of individual oscillators increases, t...In this work, we study the collective dynamics of phase oscillators in a mobile ad hoc network whose topology changes dynamically. As the network size or the communication radius of individual oscillators increases, the topology of the ad hoc network first undergoes percolation, forming a giant cluster, and then gradually achieves global connectivity. It is shown that oscillator mobility generally enhances the coherence in such networks. Interestingly, we find a new type of phase synchronization/clustering, in which the phases of the oscillators are distributed in a certain narrow range, while the instantaneous frequencies change signs frequently, leading to shuttle-run-like motion of the oscillators in phase space. We conduct a theoretical analysis to explain the mechanism of this synchronization and obtain the critical transition point.展开更多
A network is named as mixed network if it is composed of N nodes, the dynamics of some nodes are periodic, while the others are chaotic. The mixed network with all-to-all coupling and its correspond- ing networks afte...A network is named as mixed network if it is composed of N nodes, the dynamics of some nodes are periodic, while the others are chaotic. The mixed network with all-to-all coupling and its correspond- ing networks after the nonlinearity gap-condition pruning are investigated. Several synchronization states are demonstrated in both systems, and a first-order phase transition is proposed. The mixture of dynamics implies any kind of synchronous dynamics for the whole network, and the inixed networks may be controlled by the nonlinearity gap-condition pruning.展开更多
In order to enhance the stability of single-phase microgrid,virtual synchronous generator(VSG)control method is investigated in this paper.Its electromagnetic model and electromechanical model are established to illus...In order to enhance the stability of single-phase microgrid,virtual synchronous generator(VSG)control method is investigated in this paper.Its electromagnetic model and electromechanical model are established to illustrate the performance of VSG.Considering the 2 nd fluctuation of fundamental-frequency in the output power,an instantaneous power calculation strategy is proposed based on the intrinsic frequency of single-phase VSG.Besides,a virtual power calculation method is presented to achieve islanded/grid-connected seamless transition.Stability analysis and comparison simulation results demonstrate the correctness of the presented power calculation method.At last,the effectiveness of the proposed approach is verified by comparison experiments of islanded/gridconnected operations in a 500 VA single-phase inverter.展开更多
We investigated the synchronization dynamics of a coupled neuronal system composed of two identical Chay model neurons. The Chay model Showed coexisting period-1 and period-2 bursting patterns as a parameter and initi...We investigated the synchronization dynamics of a coupled neuronal system composed of two identical Chay model neurons. The Chay model Showed coexisting period-1 and period-2 bursting patterns as a parameter and initial values are varied. We simulated multiple periodic and chaotic bursting patterns with non-（NS）, burst phase （BS）, spike phase （SS）, complete （CS）, and lag synchronization states. When the coexisting behavior is near period-2 bursting, the transitions of synchronization states of the coupled system follows very complex transitions that begins with transitions between BS and SS, moves to transitions between CS and SS, and to CS. Most initial values lead to the CS state of period-2 bursting while only a few lead to the CS state of period-I bursting. When the coexisting behavior is near period-1 bursting, the transitions begin with NS, move to transitions between SS and BS, to transitions between SS and CS, and then to CS. Most initial values lead to the CS state of period-1 bursting but a few lead to the CS state of period-2 bursting. The BS was identified as chaos synchronization. The patterns for NS and transitions between BS and SS are insensitive to initial values. The patterns for transitions between CS and SS and the CS state are sensitive to them. The number of spikes per burst of non-CS bursting increases with increasing coupling strength. These results not only reveal the initial value- and parameter- dependent synchronization transitions of coupled systems with coexisting behaviors, but also facilitate interpretation of various bursting patterns and synchronization transitions generated in the nervous system with weak coupling strength.展开更多
The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order...The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes.Previous works have shown that higher-order interactions promote coherent states.However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state.Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states.Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states.All the observed results can be well described in terms of the dimension reduction method.This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial-temporal patterns in networked systems.展开更多
It is crucially important to study different synchronous regimes in coupled neurons because different regimes may correspond to different cognitive and pathological states. In this paper, phase synchronization and its...It is crucially important to study different synchronous regimes in coupled neurons because different regimes may correspond to different cognitive and pathological states. In this paper, phase synchronization and its transitions are discussed by means of theoretical and numerical analyses. In two coupled modified Morris-Lecar neurons with a gap junction, we show that the occurrence of phase synchronization can be investigated from the dynamics of phase equation, and the analytical synchronization condition is derived. By defining the phase of spike and burst, the transitions from burst synchronization to spike synchronization and then toward nearly complete synchronization can be identified by bifurcation diagrams, the mean frequency difference and time series of neurons. The simulation results suggest that the synchronization of bursting activity is a multi-time-scale phenomenon and the phase synchronization deduced by the phase equation is actually spike synchronization.展开更多
We study the synchronization transition in the Kuramoto model by considering a unidirectional cou- pling with a chain structure. The microscopic clustering features are characterized in the system. We identify several...We study the synchronization transition in the Kuramoto model by considering a unidirectional cou- pling with a chain structure. The microscopic clustering features are characterized in the system. We identify several clustering patterns for the long-time evolution of the effective frequencies and reveal the phase transition between them. Theoretically, the recursive approach is developed in order to ob- tain analytical insights; the essential bifurcation schemes of the clustering patterns are clarified and the phase diagram is illustrated in order to depict the various phase transitions of the system. Fur- thermore, these recursive theories can be extended to a larger system. Our theoretical analysis is in agreement with the numerical simulations and can aid in understanding the clustering patterns in the Kuramoto model with a general structure.展开更多
The behaviors of coupled oscillators, each of which has periodic motion with random natural frequency in the absence of coupling, are investigated when phase shifts are considered. In the system of coupled oscillators...The behaviors of coupled oscillators, each of which has periodic motion with random natural frequency in the absence of coupling, are investigated when phase shifts are considered. In the system of coupled oscillators, phase shifts are the same between different oscillators. Synchronization and synchronization transition are revealed with different phase shifts. Phase shifts play an important role for this kind of system. When the phase shift α〈 0.5π, the synchronization state can be attained by increasing the coupling, and the system cannot reach the synchronization state while α≥ 0.5π. A clear scaling between complete synchronization critical coupling strength Kpc and α - 0.5π is found.展开更多
Adaptive coupling schemes among interacting elements are ubiquitous in real systems ranging from physics and chemistry to neuroscience and have attracted much attention in recent years.Here,we extend the Kuramoto mode...Adaptive coupling schemes among interacting elements are ubiquitous in real systems ranging from physics and chemistry to neuroscience and have attracted much attention in recent years.Here,we extend the Kuramoto model by considering a particular adaptive scheme in a system of globally coupled oscillators.The homogeneous coupling is correlated with the global coherence of the population that is weighted by the generic nonlinear feedback function of the amplitude of the order parameter.The studied model is analytically tractable that generalizes the theory of Kuramoto for synchronization transition.We develop a mean-field theory by establishing the self-consistent equation describing the stationary dynamics in the thermodynamic limit.Importantly,the Landau damping effect,which turns out to be far more generic,is revealed in the framework of the linear stability analysis of the resonant pole theory.Furthermore,the relaxation rate of the order parameter in the subcritical region is obtained from a universal formula.Our study can deepen the understanding of synchronization transitions and other related collective dynamics in networked oscillators with adaptive interaction schemes.展开更多
In this paper,we propose a new method to study intermittent behaviors of coupled piecewise-expanding map lattices.We show that the successive transition between ordered and disordered phases occurs for almost every or...In this paper,we propose a new method to study intermittent behaviors of coupled piecewise-expanding map lattices.We show that the successive transition between ordered and disordered phases occurs for almost every orbit when the coupling is small.That is,lim inf n→∞∑1≤i,j≤m|x_(i)(n)−x_(j)(n)|=0,lim sup n→∞∑1≤i,j≤m|x_(i)(n)−x_(j)(n)|≥c_(0)>0,where xi(n)correspond to the coordinates of m nodes at the iterative step n.Moreover,when the uncoupled system is generated by the tent map and the lattice consists of two nodes,we prove a phase transition occurs between synchronization and intermittent behaviors.That is,limn→∞|x_(1)(n)−x_(2)(n)|=0 for c−1/2<1/4 and intermittent behaviors occur for|c−1/2|>1/4,where 0≤c≤1 is the coupling.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10872194 and 50738001)
文摘In this paper, we incorporate new parameters into a cellular automaton traffic flow model proposed in our previous paper [Jin et al. 2010 J. Stat. Mech. 2010 P03018]. Through these parameters, we adjust the anticipated velocity and the acceleration threshold separately. It turns out that the flow rate of synchronized flow mainly changes with the anticipated velocity, and the F →S phase transition feature mainly changes with the acceleration threshold. Therefore, we conclude that the acceleration threshold is the major factor affecting the F → S phase transition.
文摘Dynamics is studied for one-dimensional single-lane traffic flow by means of an extended optimal-velocity model with continuously varied bottleneck strength for nonlinear roads. Two phases exist in this model such as free flow and wide moving jam states in the systems having relatively small values of the bottleneck strength parameter. In addition to the two phases, locally congested phaseappears as the strength becomes prominent. Jam formation occurs with the similar mechanism to the boomerang effect as well as the pinch one in it. Wide scattering of the flow-density relation in fundamental diagram is found in the congested phase.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11672233, 11672231)the NPU Foundation for Fundamental Research (Grant No. 3102017AX008)+1 种基金the Seed Foundation of Innovation and Creation for Graduate Student in Northwestern Polytechnical University (Grant No. ZZ2018173)the Qian Xuesen Laboratory of Space Technology Seed Fund (Grant No. QXS-ZZJJ-02)
文摘The brain neural system is often disturbed by electromagnetic and noise environments, and research on dynamic response of its interaction has received extensive attention. This paper investigates electrical activity of Morris-Lecar neural systems exposed to sinusoidal induced electric field(IEF) with random phase generated by electromagnetic effect. By introducing a membrane depolarization model under the effect of random IEF, transition state of firing patterns, including mixed-mode oscillations(MMOs) with layered inter-spike intervals(ISI) and intermittency with a power law distribution in probability density function of ISI, is obtained in a single neuron. Considering the synergistic effects of frequency and noise, coherence resonance is performed by phase noise of IEF under certain parameter conditions. For the neural network without any internal coupling, we demonstrate that synchronous oscillations can be induced by IEF coupling, and suppression of synchronous spiking is achieved effectively by phase noise of IEF. Results of the study enrich the dynamical response to electromagnetic induction and provide insights into mechanisms of noise affecting information coding and transmission in neural systems.
基金Acknowledgements This work was supported by the Innovation Program of the Shanghai Municipal Education Commission （Grant No. 12ZZ043） the National Natural Science Foundation of China （Grant Nos. 11375066 and 11135001） and the Open Project Program of the State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China （No. Y4KF151CJ1）.
文摘In this work, we study the collective dynamics of phase oscillators in a mobile ad hoc network whose topology changes dynamically. As the network size or the communication radius of individual oscillators increases, the topology of the ad hoc network first undergoes percolation, forming a giant cluster, and then gradually achieves global connectivity. It is shown that oscillator mobility generally enhances the coherence in such networks. Interestingly, we find a new type of phase synchronization/clustering, in which the phases of the oscillators are distributed in a certain narrow range, while the instantaneous frequencies change signs frequently, leading to shuttle-run-like motion of the oscillators in phase space. We conduct a theoretical analysis to explain the mechanism of this synchronization and obtain the critical transition point.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 11135001）.
文摘A network is named as mixed network if it is composed of N nodes, the dynamics of some nodes are periodic, while the others are chaotic. The mixed network with all-to-all coupling and its correspond- ing networks after the nonlinearity gap-condition pruning are investigated. Several synchronization states are demonstrated in both systems, and a first-order phase transition is proposed. The mixture of dynamics implies any kind of synchronous dynamics for the whole network, and the inixed networks may be controlled by the nonlinearity gap-condition pruning.
基金supported by the National Basic Research Program of China(973 Program)(No.2013CB02708201)
文摘In order to enhance the stability of single-phase microgrid,virtual synchronous generator(VSG)control method is investigated in this paper.Its electromagnetic model and electromechanical model are established to illustrate the performance of VSG.Considering the 2 nd fluctuation of fundamental-frequency in the output power,an instantaneous power calculation strategy is proposed based on the intrinsic frequency of single-phase VSG.Besides,a virtual power calculation method is presented to achieve islanded/grid-connected seamless transition.Stability analysis and comparison simulation results demonstrate the correctness of the presented power calculation method.At last,the effectiveness of the proposed approach is verified by comparison experiments of islanded/gridconnected operations in a 500 VA single-phase inverter.
基金supported by the National Natural Science Foundation of China(Grant Nos.11372224 and 11402039)the Fundamental Research Funds for Central Universities designated to Tongji University(Grant No.1330219127)
文摘We investigated the synchronization dynamics of a coupled neuronal system composed of two identical Chay model neurons. The Chay model Showed coexisting period-1 and period-2 bursting patterns as a parameter and initial values are varied. We simulated multiple periodic and chaotic bursting patterns with non-（NS）, burst phase （BS）, spike phase （SS）, complete （CS）, and lag synchronization states. When the coexisting behavior is near period-2 bursting, the transitions of synchronization states of the coupled system follows very complex transitions that begins with transitions between BS and SS, moves to transitions between CS and SS, and to CS. Most initial values lead to the CS state of period-2 bursting while only a few lead to the CS state of period-I bursting. When the coexisting behavior is near period-1 bursting, the transitions begin with NS, move to transitions between SS and BS, to transitions between SS and CS, and then to CS. Most initial values lead to the CS state of period-1 bursting but a few lead to the CS state of period-2 bursting. The BS was identified as chaos synchronization. The patterns for NS and transitions between BS and SS are insensitive to initial values. The patterns for transitions between CS and SS and the CS state are sensitive to them. The number of spikes per burst of non-CS bursting increases with increasing coupling strength. These results not only reveal the initial value- and parameter- dependent synchronization transitions of coupled systems with coexisting behaviors, but also facilitate interpretation of various bursting patterns and synchronization transitions generated in the nervous system with weak coupling strength.
基金Project supported by the National Natural Science Foundation of China (Grants Nos.12375031 and 11905068)the Natural Science Foundation of Fujian Province, China (Grant No.2023J01113)the Scientific Research Funds of Huaqiao University (Grant No.ZQN-810)。
文摘The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes.Previous works have shown that higher-order interactions promote coherent states.However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state.Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states.Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states.All the observed results can be well described in terms of the dimension reduction method.This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial-temporal patterns in networked systems.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10872014 and 10802012)the Development Foundation of Science of Nanjing University of Science and Technology (Grant No.XKF09036)
文摘It is crucially important to study different synchronous regimes in coupled neurons because different regimes may correspond to different cognitive and pathological states. In this paper, phase synchronization and its transitions are discussed by means of theoretical and numerical analyses. In two coupled modified Morris-Lecar neurons with a gap junction, we show that the occurrence of phase synchronization can be investigated from the dynamics of phase equation, and the analytical synchronization condition is derived. By defining the phase of spike and burst, the transitions from burst synchronization to spike synchronization and then toward nearly complete synchronization can be identified by bifurcation diagrams, the mean frequency difference and time series of neurons. The simulation results suggest that the synchronization of bursting activity is a multi-time-scale phenomenon and the phase synchronization deduced by the phase equation is actually spike synchronization.
基金This work was supported partly by the Na- tional Natural Science Foundation of China （Grant Nos. 11605055 and 11475022）, the Fundamental Research Funds for the Cen- tral Universities of China （Grant No. 2017MS054）, and the Sci- entific Research Funds of Huaqiao University （Grant Nos. 600005- Z17Y0064 and 15BS401） and China Scholarship Council （CSC）.
文摘We study the synchronization transition in the Kuramoto model by considering a unidirectional cou- pling with a chain structure. The microscopic clustering features are characterized in the system. We identify several clustering patterns for the long-time evolution of the effective frequencies and reveal the phase transition between them. Theoretically, the recursive approach is developed in order to ob- tain analytical insights; the essential bifurcation schemes of the clustering patterns are clarified and the phase diagram is illustrated in order to depict the various phase transitions of the system. Fur- thermore, these recursive theories can be extended to a larger system. Our theoretical analysis is in agreement with the numerical simulations and can aid in understanding the clustering patterns in the Kuramoto model with a general structure.
基金Project supported in part by the National Natural Science Foundation of China (Grant No 10875011)the 973 Programme (Grant No 2007CB814805)the Foundation of Doctoral Training of China (Grant No 20060027009)
文摘The behaviors of coupled oscillators, each of which has periodic motion with random natural frequency in the absence of coupling, are investigated when phase shifts are considered. In the system of coupled oscillators, phase shifts are the same between different oscillators. Synchronization and synchronization transition are revealed with different phase shifts. Phase shifts play an important role for this kind of system. When the phase shift α〈 0.5π, the synchronization state can be attained by increasing the coupling, and the system cannot reach the synchronization state while α≥ 0.5π. A clear scaling between complete synchronization critical coupling strength Kpc and α - 0.5π is found.
基金supported by the National Natural Science Foundation of China (Grant No.11905068)the Scientific Research Funds of Huaqiao University (Grant No.ZQN-810)。
文摘Adaptive coupling schemes among interacting elements are ubiquitous in real systems ranging from physics and chemistry to neuroscience and have attracted much attention in recent years.Here,we extend the Kuramoto model by considering a particular adaptive scheme in a system of globally coupled oscillators.The homogeneous coupling is correlated with the global coherence of the population that is weighted by the generic nonlinear feedback function of the amplitude of the order parameter.The studied model is analytically tractable that generalizes the theory of Kuramoto for synchronization transition.We develop a mean-field theory by establishing the self-consistent equation describing the stationary dynamics in the thermodynamic limit.Importantly,the Landau damping effect,which turns out to be far more generic,is revealed in the framework of the linear stability analysis of the resonant pole theory.Furthermore,the relaxation rate of the order parameter in the subcritical region is obtained from a universal formula.Our study can deepen the understanding of synchronization transitions and other related collective dynamics in networked oscillators with adaptive interaction schemes.
基金This work is supported by NSFC of China(Grants Nos.11031003,11271183,11971105 and 11771205)and Simons Foundation.
文摘In this paper,we propose a new method to study intermittent behaviors of coupled piecewise-expanding map lattices.We show that the successive transition between ordered and disordered phases occurs for almost every orbit when the coupling is small.That is,lim inf n→∞∑1≤i,j≤m|x_(i)(n)−x_(j)(n)|=0,lim sup n→∞∑1≤i,j≤m|x_(i)(n)−x_(j)(n)|≥c_(0)>0,where xi(n)correspond to the coordinates of m nodes at the iterative step n.Moreover,when the uncoupled system is generated by the tent map and the lattice consists of two nodes,we prove a phase transition occurs between synchronization and intermittent behaviors.That is,limn→∞|x_(1)(n)−x_(2)(n)|=0 for c−1/2<1/4 and intermittent behaviors occur for|c−1/2|>1/4,where 0≤c≤1 is the coupling.
