Synchronization of hyperchaotic Chen systems: a class of the adaptive control approach

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.     

Adaptive generalized synchronization between Chen system and a multi-scroll chaotic system

Based on Lyapunov theory, the adaptive generalized synchronization between Chen system and a multi-scroll chaotic system is investigated. According to the form of target function a proper adaptive controller is designed, by which the controlled Chen system can be synchronized with a multi-scroll chaotic system including unknown parameters. The Lyapunov direct method is exploited to prove that the synchronization error and parameter identification error both converge to zero. Numerical simulation results verify the feasibility of the proposed method further.     

Function Projective Synchronization of Two Identical New Hyperchaotic Systems

A function projective synchronization of two identical hyperchaotic systems is defined and the theorem of sufficient condition is given. Based on the active control method and symbolic computation Maple, the scheme of function projective synchronization is developed to synchronize the two identical new hyperchaotic systems constructed by Yan up to a scaling function matrix with different initial values. Numerical simulations are used to verify the effectiveness of the scheme.     

Chaos synchronization between two different 4D hyperchaotic Chen systems

This paper presents chaos synchronization between two different four-dimensional (4D) hyperchaotic Chen systems by nonlinear feedback control laws. A modified 4D hyperchaotic Chen system is obtained by changing the nonlinear function of the 4D hyperchaotic Chen system, furthermore, an electronic circuit to realize two different 4D hyperchaotic Chen systems is designed. With nonlinear feedback control method, chaos synchronization between two different 4D hyperchaotic Chen systems is achieved. Based on the stability theory, the functions of the nonlinear feedback control for synchronization of two different 4D hyperchaotic Chen systems is derived, the range of feedback gains is determined. Numerical simulations are shown to verify the theoretical results.     

Parameter identification and synchronization of an uncertain Chen chaotic system via adaptive control

A systematic design process of adaptive synchronization and parameter identification of an uncertain Chen chaotic system is provided.With this new and effective method,parameter identification and synchronization of the Chen system,with all the system parameters unknown,can be achieved simultaneously.Theoretical proof and numerical simulation demonstrate the effectiveness and feasibility of the proposed method.     

Pitchfork bifurcation and circuit implementation of a novel Chen hyper-chaotic system

In this paper,a novel four dimensional hyper-chaotic system is coined based on the Chen system,which contains two quadratic terms and five system parameters.The proposed system can generate a hyper-chaotic attractor in wide parameters regions.By using the center manifold theorem and the local bifurcation theory,a pitchfork bifurcation is demonstrated to arise at the zero equilibrium point.Numerical analysis demonstrates that the hyper-chaotic system can generate complex dynamical behaviors,e.g.,a direct transition from quasi-periodic behavior to hyper-chaotic behavior.Finally,an electronic circuit is designed to implement the hyper-chaotic system,the experimental results are consist with the numerical simulations,which verifies the existence of the hyper-chaotic attractor.Due to the complex dynamic behaviors,this new hyper-chaotic system is useful in the secure communication.     

A formulation for the characteristic lengths of fcc materials in first strain gradient elasticity via the Sutton–Chen potential

The usual continuum theories are inadequate in predicting the mechanical behavior of solids in the presence of small defects and stress concentrators; it is well known that such continuum methods are unable to detect the change of the size of the inhomogeneities and defects. For these reasons various augmented continuum theories and strain gradient theories have been proposed in the literature. The major difficulty in implication of these theories lies in the lack of information about the additional material constants which appear in such theories. For fcc metals, for the calculation of the associated characteristic lengths which arise in first strain gradient theory, an atomistic approach based on the Sutton–Chen interatomic potential function is proposed. For the validity of the computed characteristic lengths, the phenomenon of the size effect pertinent to a nano-sized circular void within an fcc (111) plane is examined via both first strain gradient theory and lattice statics. Comparison of the results explains the physical ramifications of the characteristic lengths in improving the usual continuum results. Moreover, by reconsideration of the Kelvin problem it is shown that a commonly employed variant of the first strain gradient theory is only valid for a few fcc metals.     

Stabilization of parameters perturbation chaotic system via adaptive backstepping technique

The work of Yassen [M.T. Yassen, Chaos control of chaotic dynamical systems using backstepping design, Chaos Soliton Fract. 27 (2006) 537–548] which mainly investigated the stabilization problem for a class of chaotic systems without the parameters perturbation. This paper is concerned with stabilization problem for a class of parameters perturbation chaotic systems via both backstepping design method and adaptive technique. The proposed controllers can guarantee that the parameters perturbation systems will be stabilized at a fixed bounded point. Furthermore, the paper also proposes controllers to stabilize the uncertain chaotic system at equilibrium point with only backstepping design method. Finally, numerical simulations are given to illustrate the effectiveness of the proposed controllers.     

分数阶超混沌Chen系统和分数阶超混沌 Rössler系统的异结构同步

分数阶系统具有更大的密钥空间, 然而异结构的分数阶系统在保密通信领域更具有普遍性, 因此, 研究异结构的分数阶同步问题具有重要的意义. 本文讨论了分数阶超混沌Chen系统和分数阶超混沌Rössler系统的异结构同步问题, 基于分数阶系统稳定性理论, 应用主动控制同步法和自适应控制同步法来设计各自不同的控制器, 使得响应系统和驱动系统同步. 数值仿真表明了本文所研究方法的可行性和有效性.     

陈吸引子一个"奇怪"性质的研究

本本文主要是用几何的方法研究了陈吸引子任一邻域内存在正测度的排斥集，从而得出其吸引盆有“奇怪”的筛形性质