共查询到19条相似文献,搜索用时 93 毫秒
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针对不确定混沌系统控制问题, 研究了一种基于共轭梯度法(conjugate gradient algorithm, CGA)的多项式函数模型 (polynomial-basis-functions model, PBFM)的补偿控制方法. 该方法首先用PBFM对混沌系统的动力学特性进行拟合, 然后用拟合好的PBFM模型对不确定混沌系统进行前馈补偿控制. 该方法的特点是不需要被控混沌系统的数学模型, 可以快速跟踪任意给定的参考信号. 数值仿真试验表明了该方法不仅具有响应速度快、控制精度高, 而且具有较强的抑制混沌系统参数摄动能力和抗干扰能力.
关键词:
混沌控制
多项式函数模型
共轭梯度法 相似文献
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耦合径向基函数与多项式基函数的无网格方法 总被引:3,自引:1,他引:2
耦合径向基函数和多项式基函数,形成一种新的近似函数.该近似函数对散乱分布的离散数据点进行逼近时,只需节点信息,不需要划分网格.详细描述了耦合近似函数的建立、属性、插值行为及其形函数和形函数导数的性质.最后引入修正变分原理和单位分解积分技术求解边值问题,并给出了计算实例,表明耦合径向基函数和多项式基函数是一种非常有效的方法. 相似文献
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计算仿真发现,函数f(x,y,z)=sin(k(x2+y2+z2)),f(x,y,z)=k(1-(x2+y2+z2))e(-(x+y+z+u)2),f(x,y,z)=k((x2+y2+z2)/3)(1-(x2+y2+z2)/3)分别与另外两个随机产生的二次多项式函数均可组合成一个三维离散动力系统,当系数k,u在一定范围内取值时,系统出现混沌吸引子的概率可以大于90%.通过绘制分岔图、Lyapunov指数图等对上述系统的混沌特性进行了分析.分析发现,出现混沌概率高的原因是这3个函数的截面都是中间凸起或中间凹陷的曲面,在这样的截面条件下系统容易出现混沌.这普遍适用于三维函数,利用这些三维离散动力系统绘制出的大量吸引子图形具有使用价值和研究价值. 相似文献
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n维粒子系统的状态函数 总被引:8,自引:3,他引:5
对能谱关系为ε=ap^s(s=1,2)的n维气体作了统一讨论,并给出了n维理想气体以及n维弱简并理想费米气体和玻色气体的状态方程及各热力学函数。 相似文献
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The quantum non-relativistic two-component Bose and Fermi gases with infinitely strong point-like coupling between particles in one space dimension are considered. Time- and temperature-dependent correlation functions are represented in the thermodynamic limit as Fredholm determinants of integrable linear integral operators. 相似文献
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Structural properties of the condensate in two-dimensional mesoscopic systems of strongly correlated excitons 总被引:1,自引:0,他引:1
A two-dimensional mesoscopic Bose system of dipoles in a 2D trap is considered using computer simulation by the quantum path-integral Monte Carlo method. The model describes a rarefied system of spatially indirect excitons in a confining potential. Bose condensation in the system and its superfluid and structural properties are studied over a wide range of interparticle spatial correlations, from an almost ideal Bose gas to the regime of a strongly correlated system. It is found that, at strong interparticle spatial correlations, particles in the condensate form a crystal-like structure. In this case, the spatial correlations of particles in the condensate are less pronounced than the correlations of noncondensed particles. The effect of recurrent crystallization is observed in the regime of strong interparticle correlations. 相似文献
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应用玻色系统的基本方程,玻色积分的特性以及热力学理论,导得理想玻色气体焦汤系数的解析表达式,详细讨论了低温下玻色气体的定压热容和焦汤系数,阐明了系统的量子本性对焦汤系数的贡献,表明理想玻色气体适用于低温制冷系统。 相似文献
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Yu. E. Lozovik I. L. Kurbakov G. E. Astrakharchik M. Willander 《Journal of Experimental and Theoretical Physics》2008,106(2):296-315
The Bose condensation of two-dimensional dipolar excitons in quantum wells is numerically studied by the diffusion Monte Carlo simulation method. The correlation, microscopic, thermodynamic, and spectral characteristics are calculated. It is shown that, in structures of coupled quantum wells, in which low-temperature features of exciton luminescence have presently been observed, dipolar excitons form a strongly correlated system. 相似文献
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A one-dimensional (1D) Bose system with dipole-dipole repulsion is studied at zero temperature by means of a quantum Monte Carlo method. It is shown that, in the limit of small linear density, the bosonic system of dipole moments acquires many properties of a system of noninteracting fermions. At larger linear densities, a variational Monte Carlo calculation suggests a crossover from a liquidlike to a solidlike state. The system is superfluid on the liquidlike side of the crossover and is normal deep on the solidlike side. Energy and structural functions are presented for a wide range of densities. Possible realizations of the model are 1D Bose atomic systems, with permanent dipoles or dipoles induced by static field or resonance radiation; or indirect excitons in coupled quantum wires; etc. We propose parameters of a possible experiment and discuss manifestations of the zero-temperature quantum crossover. 相似文献
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Algbraic Structure of Two-Parameter Deformed Multi-Mode Bose Operators and Their Applications (Ⅰ) 下载免费PDF全文
Two two-parameter deformed multi-mode boss operators which satisfy quantum Heisenberg-Weyl algebra are consbucted, and their algebraic structure. studied. As examples, the Holstein-Primokoff realizations for multi-node quantum. group SU(2)q,s. and SU(1,1)q,s are presented, and the eigenstates of the second power of the two-parameter deformed multi-mode bose operators are constructed, and their completenesses are proved. 相似文献
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Abdullah Algin 《Czechoslovak Journal of Physics》2005,55(11):1309-1313
The high and low temperature thermodynamical properties of the two-parameter deformed quantum group Bose and Fermi gases with
SU
p/q
(2) symmetry are studied. Starting with a SU
p/q
(2)-invariant bosonic as well as fermionic Hamiltonian, several thermodynamical functions of the system such as the average
number of particles, internal energy and equation of state are derived. The effects of two real independent deformation parameters
p and q on the properties of the systems are discussed. Particular emphasis is given to a discussion of the Bose-Einstein condensation
phenomenon for the two-parameter deformed quantum group Bose gas. The results are also compared with earlier undeformed and
one-parameter deformed versions of Bose and Fermi gas models.
Presented at the International Colloquium “Integrable Systems and Quantum Symmetries”, Prague, 16–18 June 2005. 相似文献
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We consider the formation of entangled quantum states for an atomic Bose condensate interacting with an external electromagnetic field in a single-particle state under conditions of change in various regimes for exchange interaction processes. These states of the Bose system have high phase coherence and are accompanied by the generation of squeezed states of a new type in terms of the parameters defined by a combination of transition operators for the condensate atoms and external-field photons with an appropriate polynomial deformation of the algebra SU(2). We show that localized quantum structures corresponding to stable elementary excitations of the atoms and the field in the condensate can be formed in principle. We also analyze the purely quantum effects of collapse and revival for the level populations of the Bose condensate and the change in atomic statistics as well as determine the conditions for the formation of superstructure of these unsteady states for the Bose system. 相似文献
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《Physics letters. A》1999,260(5):400-405
The superfluidity and Bose–Einstein condensation of indirect excitons in coupled quantum dots or trapped atoms with induced dipole momenta (or dipole molecules) are studied by path-integral Monte Carlo simulations. The temperature dependencies of superfluid and Bose-condensed fraction are calculated at different strengths of interaction. Using Kosterlitz–Thouless recursion relations, we also predict the critical temperature in a macroscopic system of indirect excitons. 相似文献