Chaos in the Fractional Order Logistic Delay System

In this paper, we study the chaotic behaviors in a fractional order logistic delay system. We find that chaos exists in the fractional order logistic delay system with an order being less than 1. In addition, we numerically simulate the continuances of the chaotic behaviors in the logistic delay system with orders from 0.1 to 0.9. The lowest order we find to have chaos in this system is 0.1. Then we further investigate two methods in controlling the fractional order chaotic logistic delay system based on feedback. Finally, we investigate a lag synchronization scheme in this system. Numerical simulations show the effectiveness and feasibility of our approach.     

Chaos at Interface Brings Order into Oxide/Silicon Structure

Integration of oxides with silicon fuses advanced functional properties with a mature technological platform. In particular, direct EuO/Si contact holds high promise for spintronics but requires single-crystalline epitaxial films with atomically sharp interfaces. The standard approach employing regular 2D superstructures of metal atoms on the Si surface fails to meet the challenge. Here, an alternative route is designed and shown to solve the problem. This route avoids regular templates; the chaotic 2D distribution of metal atoms on the Si surface prevents stabilization of unwanted crystal orientations. Thus, the disordered submonolayer phase at the interface promotes order in oxide/Si coupling, as witnessed by a combination of diffraction techniques and high-resolution electron microscopy. The results not only mark tangible progress in manufacturing EuO/Si contacts but also provide a general framework for monolithic integration of functional oxides with semiconductor substrates.     

VCSELs高阶分岔及混沌行为的参数控制

基于自发辐射在微腔激光器中的独特性,利用参数开关调制控制混沌的理论和技术,对VCSELs实施高频大信号深度调制和混沌控制的数值模拟.结果表明,提高自发辐射因子可抑制VCSELs的非线性行为,通过对自发辐射因子的开关调制,可把系统由混沌状态控制到平衡态和nP周期轨道,同时给出了VCSELS各种稳定周期态、分岔数、分岔点位置和混沌带与调控参数之间的定量关系.     

混沌控制与混沌制导

提出了混沌控制的两种新途径, 并提出了混沌制导的建议。     

基于量子混沌粒子群优化算法的分数阶超混沌系统参数估计

为了对分数阶超混沌系统中的未知参数进行准确估计,提出一种量子混沌粒子群优化算法（Quantum chaos particle swarm optimization,QCPSO）.该算法通过对量子粒子群优化算法（Quantum behaved particle swarm optimization,QPSO）的实现机理进行分析,并结合量子纠缠与混沌系统之间的相关性而实现.首先,将量子势阱中心视为混沌吸引子围绕的不动点,处于吸引子外部的粒子会逐渐聚集于吸引子之内,而处于吸引子内部的粒子会出现快速分离扩散的现象;然后,采用基于随机映射的粒子更新机制,充分保证混沌粒子的初值多样性;最后,提出了基于不动点中心的尺度自适应策略,解决了算法后期的搜索停滞问题.运用QCPSO算法对典型分数阶超混沌系统参数进行估计,结果表明,该算法在收敛速度与精度上优于改进的差分进化算法、自适应人工蜂群算法以及改进的量子粒子群优化算法.     

光学混沌

本文对(有源)激光器、(无源)光学双稳态以及其他非线性光学系统中混沌的研究进展作了综述。     

混沌理论在海杂波研究中的应用

混沌理论在雷达海杂波的研究中取得了令人鼓舞的成果.基于混沌理论的海杂波模型在信号检测方面表现出较好的性能,具有很好的杂波抑制能力,对传统的雷达信号检测技术形成了一定的挑战.本文概括了海杂波混沌模型的基本概念和研究方法,分析了混沌理论在该领域的应用现状及动态,探讨了该领域研究的发展趋势.     

Chaos hamiltonien

Hamiltonian chaos is illustrated through the chaotic regime of a synchronous dipolar motor. This regime is explained with a quite simple Hamiltonian which describes the nonlinear pendulum in a particular limiting case. Phase space structure as revealed by a stroboscope relies upon the nesting of resonances and the tangle of stable and unstable manifolds.     

分数阶简并光学参量振荡器系统的混沌及同步

构建了分数阶简并光学参量振荡器系统,利用分数阶系统稳定性理论,得到了分数阶简并光学参量振荡器系统存在混沌现象的必要条件,给出了系统在满足必要条件下的混沌吸引子.实现了分数阶简并光学参量振荡器混沌系统的混沌同步,在同步过程中并未删去响应系统的所有非线性信息,理论分析和数值研究结果的一致性表明了该方法的有效性.     

Chaos and engineering

Advances in nonlinear dynamics have brought a revolution in the view of dynamical behaviour, with major implications for anyone engaged in engineering system design. The most obvious reason for knowing about chaos is to recognise it, and avoid it. For instance, chaotic modes of vibration can cause serious, and wholly unexpected, damage, threatening the stability of mechanical structures or of subsystems within communications networks. More positively, chaos can be useful. Many applications rely on some form of pseudorandom number generator: chaos theory offers a novel means of generating such numbers using simple functions. The author briefly explains the terminology of dynamic systems and then discusses Lorenz attractors, logistic mapping and bifurcation     

Chaos and locking in a semiconductor laser due to externalinjection

We have analyzed the behavior of a semiconductor laser subjected to increasing external injection. Numerical simulations show the well-known nonlinear modulation and locking regimes, followed by an intermediate chaotic region that precedes definitive locking to the external source at significantly higher injection levels     

应用PSpice模拟混沌动力学系统的方法

通过具体实例,论述用PSpice求解微分方程的方法,讨论如何用PSpice模拟混沌动力学系统中的有趣的周期分叉现象.     

电流激励蔡氏电路混沌的解析预测

考虑到蔡氏电路受周围电路的影响,故将受周围影响的蔡氏电路做了等效处理,并将其等效为电流激励蔡氏电路。这里首次用解析的方法对三阶非线性微分方程能够产生混沌的参数范围进行预测,利用该方法得出电流激励蔡氏电路产生混沌的必要参数条件。通过数值仿真证明了该等效电路具有极其丰富的混沌动力学行为,仿真结果与解析预测结果有较好的吻合性。     

Agent协商优化问题的快速混沌遗传算法

随着Internet的日益完善和电子商务的普及，如何快速、高效地进行Agent协商是我们必须面对和解决的一个重要问题。文章在Bazaar协商模型下，给出了一种快速混沌遗传算法，该算法首先将混沌机制引入遗传算法，并在搜索中，以具有一定保证的当前最优解为中心不断压缩优化变量的搜索区间，对算法进行加速。这样即克服了遗传算法过早收敛的缺点，又解决了引入混沌后遗传算法收敛慢的问题。仿真实验表明，它是解决Agent协商优化问题的一种快速有效算法。     

应用PSice模拟混沌动力学系统的方法

通过具体实例,论 述用PSice求解微分方程的方法,讨论如何用PSpice模拟混沌动力学系统中的有趣的周期分叉现象。     

短脉冲激光的二阶自相关

为了实现短脉冲激光的高动态范围信噪比(SNR)测量,满足快点火对激光驱动器的要求,开展了信噪比测量的前期研究.结合非线性晶体分析了超短脉冲的二阶自相关信号的产生过程,结果表明自相关曲线的信噪比等于原始脉冲的信噪比.同时讨论了非共线二阶自相关中,两束输入信号光的夹角变化对输出信号光强的影响.在此基础上,建立了一台二阶自相关仪以验证超短脉冲信噪比测量系统的工作性能,其信噪比测量的动态范围达到了约108.     

混沌通信的研究

本文简要介绍了混沌的概念以及近年来国内外对混沌通信的研究概况，扼要地介绍了混沌通信的几种发展     

混沌保密通信进展

讨论了现有主要的几种混沌同步的方法、原理及特点，给出了缩短混沌同步时间与参数选择的可行性方案，介绍了混沌保密通信的基本思想和各种应用方案，并做了简要分析，提出了系统实现双向通信的基本框图．     

Chaos in electronic circuits

This paper describes three extremely simple electronic circuits in which chaotic phenomena have been observed. The simplicity of the circuits allows one to i) build them easily, ii) confirm the observed phenomena by digital computer simulation, and in some cases iii) rigorously prove the circuit is indeed chaotic. A consequence of i) is that the interested reader can build, and then see and even listen to chaos. It is to be emphasized that these circuits are not analog computers. They are real physical systems.     

混沌控制综述

混沌的控制与诱导是非线性动力系统与非线性控制的新理论与新方法，是智能控制的重要组成部分，本文综述了混沌及其控制的发展历史，理论研究和应用研究，并进行了分析和评论。