共查询到20条相似文献,搜索用时 15 毫秒
1.
P. M. Gleiser D. H. Zanette 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(2):233-238
We analyze the interplay of synchronization and structure
evolution in an evolving network of phase oscillators. An initially
random network is adaptively rewired according to the dynamical
coherence of the oscillators, in order to enhance their mutual
synchronization. We show that the evolving network reaches a
small-world structure. Its clustering coefficient attains a maximum
for an intermediate intensity of the coupling between oscillators,
where a rich diversity of synchronized oscillator groups is
observed. In the stationary state, these synchronized groups are
directly associated with network clusters. 相似文献
2.
N. Rubido C. Cabeza S. Kahan G.M. Ramírez Ávila Arturo C. Marti 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(1):51-56
Stable synchronous states of different order were analytically, numerically and
experimentally characterized in pulse-coupled light-controlled oscillators (LCOs). The
Master-Slave (MS) configuration was studied in conditions where different time-scale
parameters were tuned under varying coupling strength. Arnold tongues calculated
analytically – based on the piecewise two-time-scale model for LCOs – and obtained
numerically were consistent with experimental results. The analysis of the stability
pattern and tongue shape for (1 : n) synchronization was based on the
construction of return maps representing the Slave LCO evolution induced by the action of
the Master LCO. The analysis of these maps showed that both tongue shape and stability
pattern remained invariant. Considering the wide variation range of LCO parameters, the
obtained results could have further applications on ethological models. 相似文献
3.
O. V. Zhirov D. L. Shepelyansky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):375-379
Using the methods of quantum trajectories
we study numerically a quantum dissipative
system with periodic driving which exhibits
synchronization phenomenon in the classical limit.
The model allows to analyze the effects of quantum
fluctuations on synchronization
and establish the regimes where the synchronization
is preserved in a quantum case (quantum synchronization).
Our results show that at small values
of Planck constant ħ the classical devil's staircase
remains robust with respect to quantum fluctuations
while at large ħ values synchronization
plateaus are destroyed. Quantum synchronization in our model
has close similarities with Shapiro steps in Josephson junctions
and it can be also realized in experiments with cold atoms. 相似文献
4.
A phase model for a population of oscillators with random excitatory and inhibitory mean-field coupling and subject to external white noise random forces is proposed and studied. In the thermodynamic limit different stable phases for the oscillator population may be found: (i) an incoherent state where all possible values of an oscillator phase are equally probable, (ii) a synchronized state where the population has a nonzero collective phase; (iii) a glassy phase where the global synchronization is zero but the oscillators are in phase with the random disorder; and (iv) a mixed phase where the oscillators are partially synchronized and partially in phase with the disorder. These predictions are based upon bifurcation analysis of the reduced equation valid at the thermodynamic limit and confirmed by Brownian simulation. 相似文献
5.
Phase synchronization of two linearly coupled Rossler oscillators with parameter misfits is explored.It is found that depending on parameter mismatches,the synchronization of phases exhibits different manners.The synchronization regime can be divided into three regimes.For small mismatches,the amplitude-insensitive regime gives the phase-dominant synchronization; When the parameter misfit increases,the amplitudes and phases of oscillators are correlated,and the amplitudes will dominate the synchronous dynamics for very large mismatches.The lag time among phases exhibits a power law when phase synchronization is achieved. 相似文献
6.
Sebastián Bouzat Damián H. Zanette 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(4):557-565
We study an SIS epidemiological model for a sexually
transmitted infection in a monogamous population where the formation
and breaking of couples is governed by individual preferences. The
mechanism of couple recombination is based on the so-called bar
dynamics for the marriage problem. We compare the results with those
of random recombination – where no individual preferences exist –
for which we calculate analytically the infection incidence and the
endemic threshold. We find that individual preferences give rise to
a large dispersion in the average duration of different couples,
causing substantial changes in the incidence of the infection and in
the endemic threshold. Our analysis yields also new results on the
bar dynamics, that may be of interest beyond the field of
epidemiological models. 相似文献
7.
Guy Katriel 《Physica D: Nonlinear Phenomena》2008,237(22):2933-2944
We study synchronization of oscillators that are indirectly coupled through their interaction with an environment. We give criteria for the stability or instability of a synchronized oscillation. Using these criteria we investigate synchronization of systems of oscillators which are weakly coupled, in the sense that the influence of the oscillators on the environment is weak. We prove that arbitrarily weak coupling will synchronize the oscillators, provided that this coupling is of the ‘right’ sign. We illustrate our general results by applications to a model of coupled GnRH neuron oscillators proposed by Khadra and Li [A. Khadra, Y.X. Li, A model for the pulsatile secretion of gonadotropin-releasing hormone from synchronized hypothalamic neurons, Biophys. J. 91 (2006) 74-83.], and to indirectly weakly-coupled λ-ω oscillators. 相似文献
8.
Gabriel H. Paissan 《Physica D: Nonlinear Phenomena》2008,237(6):818-828
We consider an extension of Kuramoto’s model of coupled phase oscillators where oscillator pairs interact with different strengths. When the coupling coefficient of each pair can be separated into two different factors, each one associated to an oscillator, Kuramoto’s theory for the transition to synchronization can be explicitly generalized, and the effects of coupling heterogeneity on synchronized states can be analytically studied. The two factors are respectively interpreted as the weight of the contribution of each oscillator to the mean field, and the coupling of each oscillator to that field. We explicitly analyze the effects of correlations between those weights and couplings, and show that synchronization can be completely inhibited when they are strongly anti-correlated. Numerical results validate the theory, but suggest that finite-size effect are relevant to the collective dynamics close to the synchronization transition, where oscillators become entrained in synchronized frequency clusters. 相似文献
9.
研究了考虑振子振幅效应的耦合极限环系统的同步.研究表明,耦合极限环系统的序参量随耦合强度的增加呈现非单调变化,并且出现若干不可微的点;平均频率随耦合强度的变化过程表现为同步分岔树结构;在临界点处出现了相速度的滑移、锁定和相速度差的开关阵发现象,开关阵发的平均周期具有很好的标度关系;振子的平均振幅随相同步的进程实际上是由均匀化逐渐分岔而达到非均匀化的过程,振子振幅的变化范围在临界点处突然减小.
关键词:
耦合极限环系统
同步
振幅效应 相似文献
10.
Sarira Sahu W.-Y. P. Hwang 《The European Physical Journal C - Particles and Fields》2008,58(4):609-615
We have calculated the effective potential experienced by highly relativistic neutrinos in a weakly magnetized electron–positron
plasma, where a momentum-dependent finite-width correction to the propagator of W is considered to account for the threshold effect. Magnetars are believed to be sources of TeV–PeV neutrinos which are produced
due to photomeson and proton–proton interactions in their atmosphere. We have studied the resonant-oscillation process ν
e
↔
ν
μ,τ
of the highly relativistic neutrinos in the atmosphere of SGR 1806-20, which is a magnetar. It is shown that, for high-energy
neutrinos propagating within the magnetar atmosphere, the resonance condition can never be satisfied. On the other hand, if
GeV neutrinos are produced deep inside the magnetar atmosphere, where the temperature is about 50 keV or more, then these
neutrinos can undergo resonant oscillation. 相似文献
11.
G. Yan Z. -Q. Fu G. Chen 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(4):515-520
We study the consensus dynamics with or without time-delays on directed and undirected de Bruijn graphs. Our results show
that consensus on an undirected de Bruijn graph has a lower converging speed and larger time-delay tolerance in comparison
with that on an undirected scale-free network. Although there is not much difference between the eigenvalue ratios of the
two undirected networks, we found that their dynamical properties are remarkably different; consequently, it is seemingly
more informative to consider the second smallest and the largest eigenvalues separately rather than considering their ratio
in the study of synchronization of a coupled oscillators network. Moreover, our study on directed de Bruijn graphs reveals
that properly setting directions on edges can improve the converging speed and time-delay tolerance simultaneously. 相似文献
12.
D. A. Kenwright A. Bahraminasab A. Stefanovska P. V. E. McClintock 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,65(3):425-433
We show that the transitions which occur between close orders of synchronization in the cardiorespiratory system are mainly
due to modulation of the cardiac and respiratory processes by low-frequency components. The experimental evidence is derived
from recordings on healthy subjects at rest and during exercise. Exercise acts as a perturbation of the system that alters
the mean cardiac and respiratory frequencies and changes the amount of their modulation by low-frequency oscillations. The
conclusion is supported by numerical evidence based on a model of phase-coupled oscillators, with white noise and lowfrequency
noise. Both the experimental and numerical approaches confirm that low-frequency oscillations play a significant role in the
transitional behavior between close orders of synchronization. 相似文献
13.
We identify a novel phenomenon in distinct (namely non-identical) coupled chaotic systems, which we term dynamical hysteresis.
This behavior, which appears to be universal, is defined in terms of the system dynamics (quantified for example through the
Lyapunov exponents), and arises from the presence of at least two coexisting stable attractors over a finite range of coupling,
with a change of stability outside this range. Further characterization via mutual synchronization indices reveals that one
attractor corresponds to spatially synchronized oscillators, while the other corresponds to desynchronized oscillators. Dynamical
hysteresis may thus help to understand critical aspects of the dynamical behavior of complex biological systems, e.g. seizures
in the epileptic brain can be viewed as transitions between different dynamical phases caused by time dependence in the brain’s
internal coupling. 相似文献
14.
M. Zhao T. Zhou B.-H. Wang Q. Ou J. Ren 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(3):375-379
In this paper, inspired by the idea that different nodes should
play different roles in network synchronization, we bring forward
a coupling method where the coupling strength of each node depends
on its neighbors' degrees. Compared with the uniform coupled
method and the recently proposed Motter-Zhou-Kurths method, the
synchronizability of scale-free networks can be remarkably
enhanced by using the present coupling method, and the highest
network synchronizability is achieved at β=1 which is
similar to a method introduced in [AIP Conf. Proc. 776, 201
(2005)]. 相似文献
15.
We introduce a model to study the effects of coupling-frequency correlations on synchronization in complete graphs. When the linear correlation is adopted, we find a symmetric network where frequencies of the oscillators are distributed in a bipolar way, having values either −1 or +1. In the network, the oscillators either all drift or all phase-locked. The behavior can separate qualitatively two other types of correlations, where slow and fast oscillators can remain unsynchronized respectively. It is obvious that the weighting exponent plays an important role. Besides, the numerical simulation results indicate that the linear correlation has the best performance in synchronization ability among three types of correlations in view of the average node cost. 相似文献
16.
Synchronization is a widespread phenomenon in both synthetic and real-world networks. This collective behavior of simple and complex systems has been attracting much research during the last decades. Two different routes to synchrony are defined in networks; first-order, characterized as explosive, and second-order, characterized as continuous transition. Although pioneer researches explained that the transition type is a generic feature in the networks, recent studies proposed some frameworks in which different phase and even chaotic oscillators exhibit explosive synchronization. The relationship between the structural properties of the network and the dynamical features of the oscillators is mainly proclaimed because some of these frameworks show abrupt transitions. Despite different theoretical analyses about the appearance of the first-order transition, studies are limited to the mean-field theory, which cannot be generalized to all networks. There are different real-world and man-made networks whose properties can be characterized in terms of explosive synchronization, e.g., the transition from unconsciousness to wakefulness in the brain and spontaneous synchronization of power-grid networks. In this review article, explosive synchronization is discussed from two main aspects. First, pioneer articles are categorized from the dynamical-structural framework point of view. Then, articles that considered different oscillators in the explosive synchronization frameworks are studied. In this article, the main focus is on the explosive synchronization in networks with chaotic and neuronal oscillators. Also, efforts have been made to consider the recent articles which proposed new frameworks of explosive synchronization. 相似文献
17.
We consider classical nonlinear oscillators on hexagonal lattices. When the coupling between the elements is repulsive, we observe coexisting states, each one with its own basin of attraction. These states differ by their degree of synchronization and by patterns of phase-locked motion. When disorder is introduced into the system by additive or multiplicative Gaussian noise, we observe a non-monotonic dependence of the degree of order in the system as a function of the noise intensity: intervals of noise intensity with low synchronization between the oscillators alternate with intervals where more oscillators are synchronized. In the latter case, noise induces a higher degree of order in the sense of a larger number of nearly coinciding phases. This order-by-disorder effect is reminiscent to the analogous phenomenon known from spin systems. Surprisingly, this non-monotonic evolution of the degree of order is found not only for a single interval of intermediate noise strength, but repeatedly as a function of increasing noise intensity. We observe noise-driven migration of oscillator phases in a rough potential landscape. 相似文献
18.
Y. Zhang H.A. Cerdeira G. Hu 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,23(1):97-102
A ring of diffusively coupled R?ssler oscillators, which can develop the conventional rotating wave from high-dimensional
chaos by increasing the coupling ɛ continuously is studied. The chaotic generator for the rotating wave emerges around ɛ =
ɛ, where the topological transition induced by the coupling not only changes the topological structure of all the oscillators,
which share a common strange attractor, but also changes them into being different from each other. Starting from this transition,
infinitely long range temporal correlation and spatial order in the style of antiphase state are established gradually, which
gives rise to the chaotic generator of the rotating wave.
Received 15 March 2001 相似文献
19.
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
20.
F. Mancini F. P. Mancini 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,68(3):341-351
Within the Green’s function and equations of motion formalism it is possible to exactly solve a large class of models useful
for the study of strongly correlated systems. Here, we present the exact solution of the one-dimensional extended Hubbard
model with on-site U and first nearest neighbor repulsive V interactions in the presence of an external magnetic field h,
in the narrow band limit. At zero temperature our results establish the existence of four phases in the three-dimensional
space (U, n, h) – n is the filling – with relative phase transitions, as well as different types of charge ordering. The magnetic
field may dramatically affect the behavior of thermodynamic quantities, inducing, for instance, magnetization plateaus in
the magnetization curves, and a change from a single to a double-peak tructure in the specific heat. According to the value
of the particle density, we find one or two critical fields, marking the beginning of full or partial polarization. A detailed
study of several thermodynamic quantities is also presented at finite temperature. 相似文献