Furstenberg 族和混沌

称由正整数集的某些子集构成的一个集合为一个 Furstenberg族, 如果它满足向上遗传的要求(即包含着族中某一个成员的正整数的子集也是这个族的成员). 给定一个系统 (即一个完备度量空间和其上的一个连续映射构成的偶对), 对于Furstenberg 族F, 将称空间中某些点的偶对为F-攀援偶对，使得众所周知的 Li-Yorke攀援偶对和分布式攀援偶对都成为某种特定的F-攀援偶对. 文中对F-攀援偶对构成的集合作了一般性探讨. 定义了全局性F-混沌系统和全局性强F-混沌系统, 并且对于系统是否是全局性强F-混沌的给出了一个判据.     

Furstenberg族与处处混沌及等度连续(英文)

本文引进并研究了Furstenberg族意义下的处处混沌与等度连续的概念.如果一个动力系统是F_1-敏感和F_2-可达的,则称之为(F_1,F_2)-处处混沌的,其中F_1与F_2是Furstenberg族.一个动力系统(X,f)被称为F_1-敏感的,是指存在7>0使得对任意x∈X及x的任意开邻域存在y∈U,有{n∈Z_+:d(f~n(x),f~n(y))>τ}∈F_1成立.一个动力系统(X,f)被称为F_2-可达的,是指对任意的s>O及X的任意非空开集U,V,存在x∈U,y∈V使得{n∈Z_+:d(f~n(x),f~n(y))<ε}∈F_1成立.一个动力系统被称为F-等度连续的,是指对任意的ε>0,存在δ>0,当d(x,y)<δ时有{n∈Z_+:d(f~n(x),f~n(y))<ε}∈F成立,其中F是一个Furstenberg族.     

(F_1,F_2)-攀援集的一些注记

研究(F_1,F_2)-攀援集的迭代不变性.定义了与正整数k相关的Furstenberg族的性质P(k)和Q(k).指出:对任意介于0,1之间的实数s而言,Furstenberg族M(s)具有性质P(k)和Q(k),其中■(s)表示非负整数集的所有上密度不小于s的无限子集构成的集族.据此证明了:对任意正整数k,S为系统(X,f)的(■(s),■(t))-攀援集当且仅当S为系统(X,f~k)的(■(s),■(t))-攀援集,其中s,t是介于0,1之间的任意给定的实数.     

加控制器的预估-校正算法在分数阶Chen混沌系统中的实现

讨论了分数阶预估-校正算法,并选定了对Chen混沌系统进行仿真研究.分数阶Chen混沌系统在一定的初始条件下,系统为混沌的并且仍然呈现出丰富和复杂的分数阶混沌动力学行为.在分数阶预估-校正法的基础上,用分段二次函数对Chen混沌系统方程施加控制器,使Chen混沌系统能够渐进稳定到平衡点.最后在MATLAB软件上进行仿真,得到分数阶Chen混沌系统的数值仿真稳定相图.     

攀援集与Furstenberg族

本文用Furstenberg族研究了弱混合系统的攀援集.证明了:对于每一个有不动点的离散弱混合系统(X,f)而言,存在一个不变的稠密的(τF_(inf),F_(inf))-攀援集;对于每一个弱混合的有任意周期的周期点的周期吸附系统(X,f)而言,存在一个不变的稠密的(τF_(inf),τF_(inf))-攀援集,其中τF_(inf)为非负整数集的全体thick集组成的集族,F_(inf)为非负整数集的全体无限子集组成的集族。     

异结构离散型混沌系统的延迟同步

以异结构离散型混沌系统为研究对象,设计了一种延迟同步控制器实现了离散型Henon混沌系统和Ikeda混沌系统之间的同步控制．根据稳定性定理,确定了延迟同步控制器的结构以及系统状态变量之间的误差方程．设计的延迟同步控制器对于不同的离散型混沌系统具有统一的形式,可以实现任意异结构离散型混沌系统之间的延迟同步．数值仿真模拟进一步验证了该控制器的有效性．     

关于连续区间映射的敏感依赖性

首先证明:若区间映射f是敏感依赖的,则f的拓扑熵ent(f)>0.然后通过引入一种扩张映射进一步证明了敏感依赖的区间映射的拓扑熵的下确界为0,即,上式中拓扑熵的下界0是最优的.最后通过实例展示稠混沌、Spatio-temporal混沌、Li-Yorke敏感及敏感性之间是几乎互不蕴含的.     

基于混沌同步化的广义无源性

对一般类型的混沌系统,提出了一个新的基于同步化的无源性.以Liapunov理论和线性矩阵不等式(LMI)逼近为基础.基于无源性的控制器,不仅要求其同步误差系统无源,同时要求其渐近稳定.解线性矩阵不等式表示的凸最优化问题,可以求得所建议的控制器.对Genesio-Tesi混沌系统和Qi混沌系统的仿真计算,证明所建议格式的有效性.     

Hénon混沌系统的模糊广义预测控制与同步

针对Hénon混沌系统,本文给出了一种基于T-S模糊模型的混沌系统广义预测控制算法。该方法将模糊辨识和广义预测控制结合起来应用到Hénon混沌系统中。首先,应用T-S模糊模型对Hénon混沌系统进行辨识,模糊聚类法辨识模型的前件参数,递推最小二乘法辨识结论参数。基于辨识模型,采用广义预测控制算法对其进行控制,实现了系统的跟踪与同步。仿真结果表明,与其它算法相比,该算法能够保证系统输出快速、有效地跟踪设定值。     

一类R(o)ssler混沌系统的分岔控制

研究双反馈控制的Rossler混沌系统,并根据Hopf分岔定理给出了受控Rossler混沌系统在平衡点处发生Hopf分岔的一些充分条件,数值模拟进一步验证了这种控制方法的有效性.     

Chaos via Furstenberg family couple

In this paper we define (F₁,F₂)-chaos via Furstenberg family couple F₁ and F₂. It turns out that the Li-Yorke chaos and distributional chaos can be treated as chaos in Furstenberg families sense. Some sufficient conditions such that a system is the (F₁,F₂)-chaotic (Theorems 4.2 and 4.4) are given. In addition, we construct an example as an application. It is showed that the second type of distributional chaos cannot imply the first type of distributional chaos even though the scrambled set is uncountable.     

A class of Furstenberg families and their applications to chaotic dynamics

For each sequence of positive real numbers,tending to positive infinity,a Furstenberg family is defined.All these Furstenberg families are compatible with dynamical systems.Then,chaos with respect to such Furstenberg families are intently discussed.This greatly improves some classical results of distributional chaos.To confirm the effectiveness of these improvements,the relevant examples are provided finally.     

ON F-SENSITIVE PAIRS

In the present paper, we define sensitive pairs via Furstenberg families and discuss the relation of three definitions: sensitivity, F -sensitivity and F -sensitive pairs, see Theorem 1. For transitive systems, we give some sufficient conditions to ensure the existence of F -sensitive pairs. In particular, each non-minimal E system (M system, P system) has positive lower density ( Fs , Fr resp.)-sensitive pairs almost everywhere. Moreover, each non-minimal M system is Fts -sensitive. Finally, by some exampl...     

ON F-SENSITIVE PAIRS

In the present paper, we define sensitive pairs via Furstenberg families and discuss the relation of three definitions: sensitivity, F -sensitivity and F -sensitive pairs, see Theorem 1. For transitive systems, we give some sufficient conditions to ensure the existence of F -sensitive pairs. In particular, each non-minimal E system (M system, P system) has positive lower density ( Fs , Fr resp.)-sensitive pairs almost everywhere. Moreover, each non-minimal M system is Fts -sensitive. Finally, by some examples we show that: (1) F -sensitivity can not imply the existence of F -sensitive pairs. That means there exists an F -sensitive system, which has no F -sensitive pairs. (2) There is no immediate relation between the existence of sensitive pairs and Li-Yorke chaos, i.e., there exists a system (X, f ) without Li-Yorke scrambled pairs, which has κ B -sensitive pairs almost everywhere. (3) If the system (G, f ) is sensitive, where G is a finite graph, then it has κ B -sensitive pairs almost everywhere.     

模态系统与蕴涵系统

<正> 在本文中我们采用(?)ukasiewicz 符号,以(?)分別表示“非α或β”(实质蕴涵)“α或β”(析取)“α与β“(舍取)“C_(αβ)且C_(αβ)”(实质等价)“非α”(否定).此外,我们更引入下列符号“□α”——α是必然的,必然α;“◇α”——α是可能的,可能α;“Fαβ”表示口 C_(αβ),G_(αβ)”表示 KF_(αβ)F_(αβ)(注意,它与□E_(αβ)未必相同).但须注意,在最后一节内,F_(αβ)另有意义.我们采用公理模式而不采用合有命题变元的公理,因此在证明过程中可以用不到代入规则.     

Weyl chamber flow on irreducible quotients of PSL(2, ℝ) × PSL(2, ℝ)

We study the topological dynamics of the action of the diagonal subgroup on quotients Γ\PSL(2, ℝ) × PSL(2, ℝ), where Γ is an irreducible lattice. Closed orbits are described and a set of points of dense orbit is explicitly given. Such properties are expressed using the Furstenberg boundary of the associated symmetric space ℍ × ℍ.     

On λ-Power Distributional n-Chaos

For each real number λ∈ [0, 1], λ-power distributional chaos has been introduced and studied via Furstenberg families recently. The chaoticity gets stronger and stronger as λ varies from 1 to 0, where 1-power distributional chaos is exactly the usual distributional chaos. As a generalization of distributional n-chaos, λ-power distributional n-chaos is defined similarly. Lots of classic results on distributional chaos can be improved to be the versions of λ-power distributional n-chaos accordingly. A practical method for distinguishing 0-power distributional n-chaos is given. A transitive system is constructed to be 0-power distributionally n-chaotic but without any distributionally(n + 1)-scrambled tuples. For each λ∈ [0, 1], λ-power distributional n-chaos can still appear in minimal systems with zero topological entropy.     

完备度量空间中的混沌判定

本文研究完备度量空间上的离散动力系统的混沌标准,证明了如果完备度量空间X上的连续映射f具有正则非退化返回排斥子或连接不动点的正则非退化异宿环,则存在f的不变闭子集A,使得f限制在此不变闭子集上的子系统与两个符号的符号动力系统拓扑共轭,从而获得具有这类结构的连续映射f具有Devaney混沌、分布混沌、正拓扑熵及ω-混沌,此结果改进了已有的相关结果.     

The structure of strongly stationary systems

Motivated by a problem in ergodic Ramsey theory, Furstenberg and Katznelson introduced the notion of strong stationarity, showing that certain recurrence properties hold for arbitrary measure preserving systems if they are valid for strongly stationary ones. We construct some new examples and prove a structure theorem for strongly stationary systems. The building blocks are Bernoulli systems and rotations on nilmanifolds.     

IFS中一个经典遍历性质的一些推广

该文针对概率迭代函数系统(IFS),给出一些遍历性质,这些结果推广了Elton[2]的结果,一个结果在某种意义上与Fustenberg[4]和Assani [1]关于弱混合系统中的结果类似.