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1.
Synchronization performance in time-delayed random networks induced by diversity in system parameter
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Synchronization rhythm and oscillating in biological systems can give clues to understanding the cooperation and competition between cells under appropriate biological and physical conditions. As a result, the network setting is appreciated to detect the stability and transition of collective behaviors in a network with different connection types. In this paper, the synchronization performance in time-delayed excitable homogeneous random networks(EHRNs) induced by diversity in system parameters is investigated by calculating the synchronization parameter and plotting the spatiotemporal evolution pattern, and distinct impacts induced by parameter-diversity are detected by setting different time delays. It is found that diversity has no distinct effect on the synchronization performance in EHRNs with small time delay being considered. When time delay is increased greatly, the synchronization performance of EHRN degenerates remarkably as diversity is increased. Surprisingly, by setting a moderate time delay, appropriate parameter-diversity can promote the synchronization performance in EHRNs, and can induce the synchronization transition from the asynchronous state to the weak synchronization. Moreover, the bistability phenomenon, which contains the states of asynchronous state and weak synchronization,is observed. Particularly, it is confirmed that the parameter-diversity promoted synchronization performance in time-delayed EHRN is manifested in the enhancement of the synchronization performance of individual oscillation and the increase of the number of synchronization transitions from the asynchronous state to the weak synchronization. Finally, we have revealed that this kind of parameter-diversity promoted synchronization performance is a robust phenomenon. 相似文献
2.
Phase synchronization and its transition in two coupled bursting neurons: theoretical and numerical analysis
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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. 相似文献
3.
L. Wu S. Zhu Y. Ni 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):349-354
Combination of two basic types of synchronization, anticipatory
synchronization and lagged synchronization, is investigated
numerically between two coupled semiconductor lasers. It is found
that lagged synchronization produced by a backward coupling with a
suitable delay can combine with the originally hidden anticipatory
synchronization and produce a type of synchronization overcoming the
original lagged synchronization produced by a forward coupling. We
study the combination synchronization phenomenon when the delay of
the backward coupling is different from that of the original
anticipatory synchronization. Our results suggest that the
synchronization combination phenomenon might allow an interpretation
of an experimental observation by Sivaprakasam et al. [Phys.
Rev. Lett. 87, 154101 (2001)] that the anticipating time is
irrespective of the external-cavity round trip time, which to date remains to be understood. 相似文献
4.
《Physics letters. A》2006,353(1):30-33
Noise-induced synchronization refers to the phenomenon where two uncoupled, independent nonlinear oscillators can achieve synchronization through a “common” noisy forcing. Here, “common” means identical. However, “common noise” is a construct which does not exist in practice. Noise by nature is unique and two noise signals cannot be exactly the same. How to justify and understand this central concept in noise-induced synchronization? What is the relation between noise-induced synchronization and the usual chaotic synchronization? Here we argue and demonstrate that noise-induced synchronization is closely related to generalized synchronization as characterized by the emergence of a functional relation between distinct dynamical systems through mutual interaction. We show that the same mechanism applies to the phenomenon of noise-induced (or chaos-induced) phase synchronization. 相似文献
5.
This paper studies a robust synchronization of non-autonomous chaotic systems with parameter mismatch. In the synchronization scheme, a linear state error feedback control is used to couple the master and slave horizontal platform systems excited by harmonic external forces, between which there exists a phase mismatch. A new definition of global synchronization with error bound is introduced. Using Lyapunov's stability theory, the sufficient synchronization criteria for the scheme are proven and the corresponding synchronization error bound is estimated. The synchronization criteria are further optimized by optimally designing a quadratic Lyapunov function to more precisely estimate the synchronization error bound. The illustrative simulations verify the effectiveness of these criteria. The estimated synchronization error bound is compared with numerical one in the examples. 相似文献
6.
7.
Anthony P. Stone 《Foundations of Physics Letters》1991,4(6):581-591
Assuming an Einsteinian world, formulae are given for achieving non-standard clock synchronization by various methods. It is shown that synchronization in one inertial frame simultaneously gives the same synchronization relative to all other frames. Absolute synchronization is not unique, and considerations of synchronization cannot distinguish an ether frame. In any world, synchronization with tachyons would produce the same results as other methods. 相似文献
8.
This paper is concerned with master-slave synchronization for two identical non-autonomous horizontal platform systems by using time-delay feedback control. Compared with some existing results on synchronization for horizontal platform systems, the effect of the time delay in the feedback control on master-slave synchronization is investigated. Applying a delay decomposition approach, some delay-dependent synchronization criteria are established and formulated in the form of linear matrix inequalities (LMIs). Sufficient conditions about the existence of a time delay feedback controller are derived by employing these newly obtained synchronization criteria. The controller gains can be achieved by solving a set of LMIs. One simulation example is given to illustrate the effectiveness of synchronization criteria and the design method. 相似文献
9.
A. E. Hramov A. A. Koronovskii Yu. I. Levin 《Journal of Experimental and Theoretical Physics》2005,100(4):784-794
We consider chaotic oscillator synchronization and propose a new approach for detecting the synchronized behavior of chaotic oscillators. This approach is based on analysis of different time scales in the time series generated by coupled chaotic oscillators. We show that complete synchronization, phase synchronization, lag synchronization, and generalized synchronization are particular cases of the synchronized behavior called time-scale synchronization. A quantitative measure of chaotic oscillator synchronous behavior is proposed. This approach is applied to coupled Rössler systems. 相似文献
10.
研究在超混沌信号调制参数作用下简并光学参量振荡器的混沌同步.计算结果表明,当调制系数在某确定的范围内使系统的最大条件李指数为负数时,两个或更多台简并光学参量振荡器在新的动力学基础上可实现同步或倒同步.同步方式与初始条件和调制系数有关.当初始条件确定的情况下,调制系数取某些值时,系统的同步方式具有突变性. 相似文献
11.
The partial and complete periodic synchronization in coupled discontinuous map lattices consisting of both discontinuous and non-invertible maps are discussed. We classify three typical types of periodic synchronization states, which give rise to different spatiotemporal patterns including static partial periodic synchronization, dynamically periodic synchronization, and complete periodic synchronization patterns. A special prelude dynamics of partial and complete periodic synchronization motion, which is shown by five separated concave curves in the time series plots of the order parameters,is observed. The detailed analysis shows that the special prelude dynamics is induced by the competition between two synchronized clusters, and the analytical expression for the corresponding order parameter is obtained. 相似文献
12.
基于自适应的方法, 提出了一种同步时间可控的混沌投影同步方法. 该方法针对一类不同的混沌系统设计了通用的同步控制器和参数自适应律, 使驱动系统的状态变量和响应系统的状态变量按照给定比例矩阵达到同步, 同步误差按预设的指数速率收敛. 由于比例矩阵和指数速率不为第三方所知, 可提高信息的抗破译能力. 同时, 通过调节相关控制器参数, 可在有限时间内达到投影同步, 并实现对同步时间的有效控制. 数值模拟结果的对比和分析验证了所提方法是有效的和鲁棒的.
关键词:
混沌
自适应控制
投影同步
时间可控 相似文献
13.
混沌系统的相同步现象是近几年混沌同步研究的热点,它反映了混沌运动中的有序行为.用分岔树来研究耦合系统相同步的进程,并用Lyapunov指数谱来探讨系统动力学在相同步时从高维混沌向低维混沌过渡的进程.发现了从多个有理同步的时间交替到完全相同步的道路.还 发现了相同步中的混沌抑制及通过倍周期分岔向混沌同步的恢复.此外,研究表明,非对称 耦合可以大大加强耦合系统的相同步,这对实际应用有重要的意义.
关键词:
相同步
分岔树
李指数 相似文献
14.
15.
改进恒Lyapunov指数谱混沌系统的特殊的分段线性结构及其全局线性调幅参数与倒相参数的存在性,赋予了其同步体系新的可实现性与可调节性.依据广义同步的原理,构造合适的驱动系统与响应系统,可以实现恒Lyapunov指数谱混沌系统的广义同步;改变响应系统的参数,可实现完全同步与广义投影同步;改进恒Lyapunov指数谱混沌系统的全局线性调幅参数能对驱动与响应系统的状态变量幅值实施同步升降控制,倒相参数能对某一特定状态变量实施同步倒相控制.这种同步体系无需专门的控制器,结构简单,易于实现.文章最后设计了同步体系的实现电路,实验仿真结果证明了混沌同步方法的可行性,也验证了恒指数谱混沌系统特殊参数对同步体系状态变量幅值与相位的调控作用. 相似文献
16.
常规光幕实现发射器和接收器双方信号的同步需要专用同步电缆来完成。针对这一缺点,提出了一种新的高速光幕同步方法,即在发射器的每个循环周期的第一通道发射光脉冲之前增加一个作为帧同步码的光脉冲段,接收端通过判断帧同步码的方式实现收发信号同步,这样便不再需要专用同步电缆,有效地节省了光幕同步系统成本。进一步地,采用新提出的高速光幕同步方法,基于FPGA技术,设计并实现了高速光幕同步系统的总体方案,硬件制作了可应用于高速运动物体的实时到位检测的高速光幕检测装置。实际工程应用表明,采用此方法的高速光幕检测装置,成本低,工作稳定可靠,捕捉与同步性能优良。 相似文献
17.
This paper deals with the chaotic oscillator synchronization. An approach to the synchronization of chaotic oscillators has been proposed. This approach is based on the analysis of different time scales in the time series generated by the coupled chaotic oscillators. It has been shown that complete synchronization, phase synchronization, lag synchronization, and generalized synchronization are the particular cases of the synchronized behavior called "time-scale synchronization." The quantitative measure of chaotic oscillator synchronous behavior has been proposed. This approach has been applied for the coupled R?ssler systems and two coupled Chua's circuits. 相似文献
18.
The synchronization of hyperchaotic Chen systems is
considered. An adaptive synchronization approach and a cascade
adaptive synchronization approach are presented to synchronize a
drive system and a response system. By utilizing an adaptive
controller based on the dynamic compensation mechanism, exact
knowledge of the systems is not necessarily required, and the
synchronous speed is controllable by tuning the controller
parameters. Sufficient conditions for the asymptotic stability of
the two synchronization schemes are derived. Numerical simulation
results demonstrate that the adaptive synchronization scheme with
four control inputs and the cascade adaptive synchronization scheme
with only one control signal are effective and feasible in chaos
synchronization of hyperchaotic systems. 相似文献
19.
A. A. Koronovskiĭ P. V. Popov A. E. Hramov 《Journal of Experimental and Theoretical Physics》2006,103(4):654-665
Generalized synchronization is analyzed in unidirectionally coupled oscillatory systems exhibiting spatiotemporal chaotic behavior described by Ginzburg-Landau equations. Several types of coupling between the systems are analyzed. The largest spatial Lyapunov exponent is proposed as a new characteristic of the state of a distributed system, and its calculation is described for a distributed oscillatory system. Partial generalized synchronization is introduced as a new type of chaotic synchronization in spatially nonuniform distributed systems. The physical mechanisms responsible for the onset of generalized chaotic synchronization in spatially distributed oscillatory systems are elucidated. It is shown that the onset of generalized chaotic synchronization is described by a modified Ginzburg-Landau equation with additional dissipation irrespective of the type of coupling. The effect of noise on the onset of a generalized synchronization regime in coupled distributed systems is analyzed. 相似文献