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1.
We report experimental observation of phase synchronization in an array of nonidentical noncoupled noisy neuronal oscillators, due to stimulation with external noise. The synchronization derives from a noise-induced qualitative change in the firing pattern of single neurons, which changes from a quasiperiodic to a bursting mode. We show that at a certain noise intensity the onsets of bursts in different neurons become synchronized, even though the number of spikes inside the bursts may vary for different neurons. We demonstrate this effect both experimentally for the electroreceptor afferents of paddlefish, and numerically for a canonical phase model, and characterize it in terms of stochastic synchronization. 相似文献
2.
Zheng Zhi-gang Feng Xiao-qin Ao Bin Michael C. Cross 《Frontiers of Physics in China》2006,1(4):458-467
In this paper, partial synchronization (PaS) in networks of coupled chaotic oscillator systems and synchronization in sparsely
coupled spatiotemporal systems are explored. For the PaS, we reveal that the existence of PaS patterns depends on the symmetry
property of the network topology, while the emergence of the PaS pattern depends crucially on the stability of the corresponding
solution. An analytical criterion in judging the stability of PaS state on a given network are proposed in terms of a comparison
between the Lyapunov exponent spectrum of the PaS manifold and that of the transversal manifold. The competition and selections
of the PaS patterns induced by the presence of multiple topological symmetries of the network are studied in terms of the
criterion. The phase diagram in distinguishing the synchronous and the asynchronous states is given. The criterion in judging
PaS is further applied to the study of synchronization of two sparsely coupled spatiotemporal chaotic systems. Different synchronization
regimes are distinguished. The present study reveals the intrinsic collective bifurcation of coupled dynamical systems prior
to the emergence of global synchronization. 相似文献
3.
4.
We investigate the synchronization of complex networks,which are impulsively coupled only at discrete instants.Based on the comparison theory of impulsive differential systems,a distributed impulsive control scheme is proposed for complex dynamical networks to achieve synchronization.The proposed scheme not only takes into account the influence of all nodes to network synchronization,which depends on the weight of each node in the network,but also provides us with a flexible method to select the synchronized state of the network.In addition,it is unnecessary for the impulsive coupling matrix to be symmetrical.Finally,the proposed control scheme is applied to a chaotic Lorenz network and Chua’s circuit network.Numerical simulations are used to illustrate the validity of this control scheme. 相似文献
5.
We considered coupled map lattices with long-range interactions to study the spatiotemporal behaviour of spatially extended
dynamical systems. Coupled map lattices have been intensively investigated as models to understand many spatiotemporal phenomena
observed in extended system, and consequently spatiotemporal chaos. We used the complex order parameter to quantify chaos
synchronization for a one-dimensional chain of coupled logistic maps with a coupling strength which varies with the lattice
in a power-law fashion. Depending on the range of the interactions, complete chaos synchronization and chaos suppression may
be attained. Furthermore, we also calculated the Lyapunov dimension and the transversal distance to the synchronization manifold. 相似文献
6.
This Letter presents an analytical study of synchronization in an array of coupled deterministic Boolean networks. A necessary and sufficient criterion for synchronization is established based on algebraic representations of logical dynamics in terms of the semi-tensor product of matrices. Some basic properties of a synchronized array of Boolean networks are then derived for the existence of transient states and the upper bound of the number of fixed points. Particularly, an interesting consequence indicates that a “large” mismatch between two coupled Boolean networks in the array may result in loss of synchrony in the entire system. Examples, including the Boolean model of coupled oscillations in the cell cycle, are given to illustrate the present results. 相似文献
7.
We review some recent work on the synchronization of coupled dynamical systems on a variety of networks. When nodes show synchronized
behaviour, two interesting phenomena can be observed. First, there are some nodes of the floating type that show intermittent
behaviour between getting attached to some clusters and evolving independently. Secondly, two different ways of cluster formation
can be identified, namely self-organized clusters which have mostly intra-cluster couplings and driven clusters which have
mostly inter-cluster couplings. 相似文献
8.
In this Letter, singular hybrid coupled systems are introduced to describe complex networks with a special class of constraints. The synchronization problem of singular hybrid coupled systems with time-varying nonlinear perturbation is investigated. A sufficient condition for global synchronization is derived based on the Lyapunov stability theory. The singular system is regular and impulse free. Finally, a numerical example is provided to illustrate the effectiveness of the proposal conditions. 相似文献
9.
Fumito Mori 《Physica D: Nonlinear Phenomena》2009,238(14):1180-1185
We investigate the synchronous dynamics of Kuramoto oscillators and van der Pol oscillators on Watts-Strogatz type small-world networks. The order parameters to characterize macroscopic synchronization are calculated by numerical integration. We focus on the difference between frequency synchronization and phase synchronization. In both oscillator systems, the critical coupling strength of the phase order is larger than that of the frequency order for the small-world networks. The critical coupling strength for the phase and frequency synchronization diverges as the network structure approaches the regular one. For the Kuramoto oscillators, the behavior can be described by a power-law function and the exponents are obtained for the two synchronizations. The separation of the critical point between the phase and frequency synchronizations is found only for small-world networks in the theoretical models studied. 相似文献
10.
We study global stability of synchronization in asymmetrically connected networks of limit-cycle or chaotic oscillators. We extend the connection graph stability method to directed graphs with node balance, the property that all nodes in the network have equal input and output weight sums. We obtain the same upper bound for synchronization in asymmetrically connected networks as in the network with a symmetrized matrix, provided that the condition of node balance is satisfied. In terms of graphs, the symmetrization operation amounts to replacing each directed edge by an undirected edge of half the coupling strength. It should be stressed that without node balance this property in general does not hold. 相似文献
11.
This Letter focuses on the synchronization in a class of dynamical complex networks with each node being a deterministic ratchet. In virtue of the technique derived from pendulum-like nonlinear analytic theory and Kalman–Yakubovich–Popov (KYP) lemma, simple linear matrix inequality (LMI) formulations are established to guarantee the stable synchronization of such networks. An interesting conclusion is reached that the stability of synchronization in the coupled whole N-dimensional networks can be converted into that of the simplest 2-dimensional space. 相似文献
12.
We study the emergence of collective synchronization in large directed networks of heterogeneous oscillators by generalizing the classical Kuramoto model of globally coupled phase oscillators to more realistic networks. We extend recent theoretical approximations describing the transition to synchronization in large undirected networks of coupled phase oscillators to the case of directed networks. We also consider the case of networks with mixed positive-negative coupling strengths. We compare our theory with numerical simulations and find good agreement. 相似文献
13.
Casado JM 《Physical review letters》2003,91(20):208102
The focus of this Letter is on the activity of a network of neurons pairwise coupled by inhibitory connections. Each neuron is represented by a two-dimensional map capable, when isolated, of a rich variety of complex dynamical regimes. It is shown that the network exhibits a stimulus-dependent sequential activation and inactivation of subgroups of neurons. This complex behavior is rather similar to some spatiotemporal features observed in the first stages of the olfaction process in some insects and suggests the possibility of large scale simulation of these processes by using reasonable computational capabilities. 相似文献
14.
Some scalar linear controllers, which can ensure that the states of coupled chaotic dynamical networks asymptotically synchronize each other, are derived on the basis of high gain state feedback control. Numerical simulation is given to validate the proposed theoretical result. 相似文献
15.
The collective synchronization of a system of coupled logistic maps on random community networks is investigated. It is found that the synchronizability of the community network is affected by two factors when the size of the network and the number of connections are fixed. One is the number of communities denoted by the parameter rn, and the other is the ratio σ of the connection probability p of each pair of nodes within each community to the connection probability q of each pair of nodes among different communities. Theoretical analysis and numerical results indicate that larger rn and smaller σ are the key to the enhancement of network synchronizability. We also testify synchronous properties of the system by analysing the largest Lyapunov exponents of the system. 相似文献
16.
Cascades with coupled map lattices in preferential attachment community networks 总被引:2,自引:0,他引:2 下载免费PDF全文
In this paper, cascading failure is studied by coupled map lattice (CML) methods in preferential attachment community networks. It is found that external perturbation R is increasing with modularity Q growing by simulation. In particular, the large modularity Q can hold off the cascading failure dynamic process in community networks. Furthermore, different attack strategies also greatly affect the cascading failure dynamic process. It is particularly significant to control cascading failure process in real community networks. 相似文献
17.
N. Kouvaris A. Provata 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(4):535-541
Long distance reactive and diffusive coupling is introduced in a spatially extended nonlinear stochastic network of interacting
particles. The network serves as a substrate for Lotka-Volterra dynamics with 3rd order nonlinearities. If the network includes
only local nearest neighbour interactions, the system organizes into a number of local asynchronous oscillators. It is shown
that (a) Introduction of all-to-all coupling in the network leads the system into global, center-type, conservative oscillations
as dictated by the mean-field dynamics. (b) Introduction of reactive coupling to the network leads the system to intermittent
oscillations where the trajectories stick for short times in bounded regions of space, with subsequent jumps between different
bounded regions. (c) Introduction of diffusive coupling to the system does not alter the dynamics for small values of the
diffusive coupling pdiff, while after a critical value pdiff
c the system synchronizes into a limit cycle with specific frequency, deviating non-trivially from the mean-field center-type
behaviour. The frequency of the limit cycle oscillations depends on the reaction rates and on the diffusion coupling. The
amplitude σ of the limit cycle depends on the control parameter pdiff. 相似文献
18.
In this paper, the whole dynamical process of cascading failures in a class of scale-free coupled map lattices (CML’s), from the occurrence of attack to the end of failure propagation, is investigated. A dynamical model of cascading failures, based on synergetic theory, is constructed. Numerical simulations show that the macroscopic properties of the scale-free CML’s during cascading failure propagation are governed by the general laws of synergetics. This result will be useful in furthering the studies of the prediction and prevention of cascading events in many real-life complex networks. 相似文献
19.
We use symbolic dynamics to study discrete-time dynamical systems with multiple time delays. We exploit the concept of avoiding sets, which arise from specific non-generating partitions of the phase space and restrict the occurrence of certain symbol sequences related to the characteristics of the dynamics. In particular, we show that the resulting forbidden sequences are closely related to the time delays in the system. We present two applications to coupled map lattices, namely (1) detecting synchronization and (2) determining unknown values of the transmission delays in networks with possibly directed and weighted connections and measurement noise. The method is applicable to multi-dimensional as well as set-valued maps, and to networks with time-varying delays and connection structure. 相似文献
20.
This paper proposes new delay-dependent synchronization criteria for coupled Hopfield neural networks with time-varying delays. By construction of a suitable Lyapunov-Krasovskii's functional and use of Finsler's lemma, novel synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed methods. 相似文献