共查询到18条相似文献,搜索用时 78 毫秒
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混沌系统的平均绝对误差增长最初是用来刻画初始值误差增长的,本文依照平均绝对误差增长的定义来研究模型误差的增长过程,获得了一些很有意义的结论.研究发现,在初期模型误差的平均绝对误差增长呈指数级增长,增长指数同模型的扰动相关,与真实系统最大Lyapunov指数没有直接关系.其后模型误差进入非线性增长过程,误差增长放缓,最终达到饱和.误差饱和值恒定,当真实系统和模型系统吸引子差别较小时,模型误差饱和值基本上同真实系统的初始值误差饱和值相等.利用上述研究结论可以求出模型的可预报期限,这在数值天气预报中具有重要的意义.进而利用模型的可预报期限可以对同一真实系统的不同模型进行评价,相对真实系统越精确的模型拥有更高的可预报期限.这对新模型的开发具有很强的指导作用. 相似文献
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利用非线性误差增长理论计算了Logistic映射和Lorenz系统可预报期限随初始误差的变化,发现Logistic映射等简单混沌系统的可预报期限与初始误差的对数存在线性关系.在非线性误差增长理论的框架下,理论分析表明,平均误差增长达到一定值时,误差增长进入明显的非线性增长阶段,最终达到饱和;对于一个确定的混沌系统,在控制参数固定的情况下误差增长的饱和值也是固定的,因此可预报期限只依赖于初始误差. 在可预报期限与初始误差对数存在的线性函数关系式中,线性系数与最大Lyapunov指数有关,在已知混沌系统的最大
关键词:
非线性局部Lyapunov指数
可预报期限
初始误差
混沌系统 相似文献
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对Pecora和Carroll的混沌自同步方案的延迟同步误差进行了研究.在计算机上对Lorenz混沌系统伪装的延迟同步误差进行了模拟:给定系统参数,对应不同延迟时间,得出了均方误差与采样步长的关系曲线;给定系统参数和延迟时间,对应不同采样步长,得到了混沌时间序列的误差曲线;给定采样步长,对应不同的系统参数,获得了混沌时间序列的尺度效应和均方误差与采样步长的关系曲线.提出了减小延迟同步误差的一些方法,得到一些对混沌同步和混沌控制应用有意义的结果.
关键词:
混沌同步
时间同步
误差分析 相似文献
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混沌和超混沌系统中的奇怪吸引子及其分析 总被引:1,自引:0,他引:1
用四阶定步长龙格—库塔算法对几种混沌和超混沌系统进行数值求解,绘制了各种系统典型奇怪吸引子的相图,对奇怪吸引子的结构和特性进行了分析。 相似文献
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Suppressing chaos by parametric perturbation at doubled frequency of periodic perturbation 下载免费PDF全文
An analysis of the chaos suppression of a nonlinear elastic beam(NLEB)is presented.In terms of modal transformation the equation of NLEB is reduced to the Duffing equation.It is shown that the chaotic behaviour of the NLEB is sensitively dependent on the parameters of perturbations and initial conditions.By adjusting the frequency of parametric perturbation to twice that of the periodic one and the amplitude of parametric pertubation to the same as the periodic one,the chaotic region of the nonlinear elastic beam driven by periodic force can be greatly suppressed. 相似文献
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Spatial orders appearing at instabilities of synchronous chaos of spatiotemporal systems 总被引:1,自引:0,他引:1
Shihong Wang Jinghua Xiao Xingang Wang Bambi Hu Gang Hu 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,30(4):571-575
Various spatial orders introduced by the instabilities of synchronous chaotic state of spatiotemporal systems are investigated
by considering coupled map lattice and chaotic partial differential equation. In particular, the motions of on-off intermittent
states at the onset of the instabilities are studied in detail. The chaotic desynchronized patterns can be described by a
simple universal form, including three parts: the synchronous chaos; a spatially ordered pattern, determined by the unstable
mode of the reference synchronous chaos; and on-off intermittency of the scale of this given pattern.
Received 31 July 2002 / Received in final form 20 November 2002 Published online 31 December 2002 相似文献
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This paper proposes a new method to chaotify the discrete-time fuzzy hyperbolic model (DFHM) with uncertain parameters. A simple nonlinear state feedback controller is designed for this purpose. By revised Marotto theorem, it is proven that the chaos generated by this controller satisfies the Li-Yorke definition. An example is presented to demonstrate the effectiveness of the approach. 相似文献
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Haibo Xu Guangrui Wang Shigang Chen 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,22(1):65-69
By adjusting external control signal, rather than some available parameters of the system, we modify the straight-line stabilization
method for stabilizing an unstable periodic orbit in a neighborhood of an unstable fixed point formulated by Ling Yang et al., and derive a more simple analytical expression of the external control signal adjustment. Our technique solves the problem
that the unstable fixed point is independent of the system parameters, for which the original straight-line stabilization
method is not suitable. The method is valid for controlling dissipative chaos, Hamiltonian chaos and hyperchaos, and may be
most useful for the systems in which it may be difficult to find an accessible system parameter in some cases. The method
is robust under the presence of weak external noise.
Received 10 January 2001 相似文献
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We present the generalized forms of Parrondo's paradox existing in fractional-order nonlinear systems. The generalization is implemented by applying a parameter switching(PS) algorithm to the corresponding initial value problems associated with the fractional-order nonlinear systems. The PS algorithm switches a system parameter within a specific set of N ≥ 2 values when solving the system with some numerical integration method. It is proven that any attractor of the concerned system can be approximated numerically. By replacing the words "winning" and "loosing" in the classical Parrondo's paradox with "order" and "chaos", respectively, the PS algorithm leads to the generalized Parrondo's paradox:chaos_1+ chaos_2+ ··· + chaosN= order and order_1+ order_2+ ··· + orderN= chaos. Finally, the concept is well demonstrated with the results based on the fractional-order Chen system. 相似文献