Robust adaptive synchronization of chaotic neural networks by slide technique

In this paper, we focus on the robust adaptive synchronization between two coupled chaotic neural networks with all the parameters unknown and time-varying delay. In order to increase the robustness of the two coupled neural networks, the key idea is that a sliding-mode-type controller is employed. Moreover, without the estimate values of the network unknown parameters taken as an updating object, a new updating object is introduced in the constructing of controller. Using the proposed controller, without any requirements for the boundedness, monotonicity and differentiability of activation functions, and symmetry of connections, the two coupled chaotic neural networks can achieve global robust synchronization no matter what their initial states are. Finally, the numerical simulation validates the effectiveness and feasibility of the proposed technique.     

Chaotic motion of the dynamical system under both additive and multiplicative noise excitations

With both additive and multiplicative noise excitations, the effect on the chaotic behaviour of the dynamical system is investigated in this paper. The random Melnikov theorem with the mean-square criterion that applies to a type of dynamical systems is analysed in order to obtain the conditions for the possible occurrence of chaos. As an example, for the Duffing system, we deduce its concrete expression for the threshold of multiplicative noise amplitude for the rising of chaos, and by combining figures, we discuss the influences of the amplitude, intensity and frequency of both bounded noises on the dynamical behaviour of the Duffing system separately. Finally, numerical simulations are illustrated to verify the theoretical analysis according to the largest Lyapunov exponent and Poincaré map.     

The effects of interstitial oxygen on superconducting electronic phases in strontium and oxygen co-doped La1.937Sr0.063CuO4＋δ

Strontium and oxygen co-doped La1.937Sr0.063CuO4＋δ superconductor with Tc≈ 40K, which is obtained by oxidizing strontium-doped starting ceramic sample La1.937Sr0.063CuO4 in NaC10 solution, is annealed under different conditions to allow interstitial oxygen to redistribute. The evolution of the intrinsic superconducting property with the oxygen redistribution is studied in detail by magnetic measurements in various fields. It is found that there occurs the electronic phase separation from the single superconducting phase with Tc ≈ 40 K into two coexisting superconducting states with values of Tc： 15 and 40K or of 15 and 35 K in this system, depending on annealing condition. Our results indicate that the 15, 35 and 40 K superconducting phases associated with the excess oxygen redistribution are all thermodynamically meta-stable intrinsic states in this Sr/O co-doped cuprate.     

Adaptive generalized projective synchronization of two different chaotic systems with unknown parameters

This paper presents a general method of the generalized projective synchronization and the parameter identification between two different chaotic systems with unknown parameters. This approach is based on Lyapunov stability theory, and employs a combination of feedback control and adaptive control. With this method one can achieve the generalized projective synchronization and realize the parameter identifications between almost all chaotic （hyperchaotic） systems with unknown parameters. Numerical simulations results are presented to demonstrate the effectiveness of the method.     

伪轨跟踪与混沌

本文对具有无限个点的紧致度量空间上的连续满射，研究了伪轨跟踪性质与Ｒｕｅｌｌｅ－Ｔａｋｅｎｓ意义下的混沌、拓扑混合及具有性质Ｐ的关系．     

一类描述混沌映射的符号动力系统

本文定义了符号空间上的拟移位映射,并用该类映射描述了Ｃａｎｔｏｒ集及平面Ｃａｎｔｏｒ集上的混沌映射,本文结果可看作Ｓｍａｌｅ马蹄模型的简化。     

A Spatiotemporal-Chaos-Based Cryptosystem Taking Advantage of Both Synchronous and Self-Synchronizing Schemes

Two-dimensional one-way coupled map lattices are used for cryptography where multiple space units producechaotic outputs in parallel. One of the outputs plays the role of driving for synchronization of the decryption sys-tem while the others perform the function of information encoding. With this separation of functions the receivercan establish a self-checking and self-correction mechanism, and enjoys the advantages of both synchronous andself-synchronizing schemes. A comparison between the present system with the system of advanced encryptionstandard (AES) is presented in the aspect of channel noise influence. Numerical investigations show that oursystem is much stronger than AES against channel noise perturbations, and thus can be better used for securecommunications with large channel noise.     

量子混沌在谱涨落统计特征上的表象

通过对Ｈｅｎｏｎ－Ｈｅｉｌｅｓ模型、Ｂａｒｂａｎｉｓ模型和刚环转球模型这两类三种守恒体系之对应量子体系的研究，具体地剖析了本征值谱涨落统计特征与体系动力学行为的联系，说明了量子混沌现象的两种表现形式。同时，通过将本质上属于经典耗散系范畴的Ｌｏｔｋａ－Ｖｏｌｔｅｒｒａ模型之演化方程哈密顿化，发现其量子对应系本征值谱的涨落统计特征超出了Ｐｏｉｓｓｏｎ－ＧＯＥ（Ｗｉｇｎｅｒ）或ＧＵＥ框架。揭示出经典耗散     

混沌和超混沌系统中的奇怪吸引子及其分析

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。     

高能碰撞各向异性动力学起伏的一个定量判据 *

通过对自仿射随机级联模型的Levy稳定性研究,发现其Levy稳定性指数不仅依赖于动力学起伏参数α而且依赖于统计阶乘矩时相空间的收缩方式.这样就提供了一种定量地判断动力学起伏是否各向异性的方法.另外,还从各向异性动力学起伏的假定出发,成功地解释了NA22实验组关于Levy稳定性破坏的实验结果.