Attractor and dimension for strongly damped nonlinear wave equation

1. IntroductionConsider the strongly damped nonlinear wave equationwith the Dirichlet boundary conditionand the initial value conditionswhere u = u(x, t) is a real--valued function on fi x [0, co), fi is an open bounded set of R"with smooth boundary off, or > 0, g e L'(fl), D(--Q) ~ Ha(~~) n H'(fl).We assume for the function f(u) as follows'f(u) E CI (R, R) satisfiesfor any ig al, uZ E R, where k, hi > 0, i ~ 0, 1, 2, 61 > 0 and 0 5 6o < 1'The type of equation (1) can be regarded as the…     

Structure of the global attractor for a second order strongly damped lattice system

In this paper, we consider the dynamical behavior of a second order strongly damped lattice system where the coupled operator is nonnegative definite symmetric. Firstly, we prove the existence of a global attractor, and give an upper bound of Hausdorff dimension of the global attractor, which keeps bounded for large strongly damping. Then we show that when the damping term is linear and the damping is suitable large, the system has an unbounded one-dimensional global attractor, which is a restricted horizontal curve.     

有界多连通区域具线性阻尼Navier-Stokes方程的有限维行为

考虑二维有界多连通区域上具线性阻尼Navier-Stokes方程,在适当的边界条件下证明了解的存在唯一性及整体吸引子A的存在性,并给出了A的Hausdorff维数与Fractal维数.     

Kernel sections for non-autonomous strongly damped wave equations

We prove the existence of compact kernel sections for the process generated by a non-autonomous strongly damped wave equation with homogeneous Dirichlet boundary condition. We show that the upper bound of the Hausdorff dimension of sections decreases as the damping grows for large strong damping.     

有阻尼Sine－Gordon方程的全局吸引子的维数

本文通过引入新范数，得到有阻尼Ｓｉｎｅ－Ｇｏｒｄｏｎ方程的Ｄｉｒｉｃｈｌｅｔ问题的全局吸引子的维数的一个估计．结果表明：当“阻尼”与“扩散”同时增大或正弦项系数减小时，吸引子的维数减小．特别地，得到了零维吸引子存在的参数条件．     

有阻尼Sine－Gordon方程的全局吸引子的维数

本文通过引入新范数,得到有阻尼Ｓｉｎｅ－Ｇｏｒｄｏｎ方程的Ｄｉｒｉｃｈｌｅｔ问题的全局吸引子的维数的一个估计．结果表明：当“阻尼”与“扩散”同时增大或正弦项系数减小时,吸引子的维数减小．特别地,得到了零维吸引子存在的参数条件．     

Dimension of the global attractor for the discretized damped sine-Gordon equation

This paper presents a more precise estimate on the dimension of the global attractor for spatially discretized damped sine-Gordon equation with periodic boundary condition. The gained Hausdorff dimension is consistent with the continuous case and conforms to physics.     

Hausdorff Dimension in Convex Bornological Spaces

For non-metrizable spaces the classical Hausdorff dimension is meaningless. We extend the notion of Hausdorff dimension to arbitrary locally convex linear topological spaces and thus to a large class of non-metrizable spaces. This involves a limiting procedure using the canonical bornological structure. In the case of normed spaces the new notion of Hausdorff dimension is equivalent to the classical notion.     

A new fractal dimension: The topological Hausdorff dimension

We introduce a new concept of dimension for metric spaces, the so-called topological Hausdorff dimension. It is defined by a very natural combination of the definitions of the topological dimension and the Hausdorff dimension. The value of the topological Hausdorff dimension is always between the topological dimension and the Hausdorff dimension, in particular, this new dimension is a non-trivial lower estimate for the Hausdorff dimension.     

用非线性方程组求解等式约束非线性规划问题的降维算法

本文研究线性和非线性等式约束非线性规划问题的降维算法.首先,利用一般等式约束问题的降维方法,将线性等式约束非线性规划问题转换成一个非线性方程组,解非线性方程组即得其解;然后,对线性和非线性等式约束非线性规划问题用Lagrange乘子法,将非线性约束部分和目标函数构成增广的Lagrange函数,并保留线性等式约束,这样便得到一个线性等式约束非线性规划序列,从而,又将问题转化为求解只含线性等式约束的非线性规划问题.     

Zd中离散分形指标的线性不变性质

研究欧几里得格 Zd 内离散分形指标的线性不变性质 ,即证明了上、下离散质量维数的线性不变性质 ,离散 Hausdorff维数的线性不变性质以及离散填充维数的线性不变性质 .     

非线性阻尼非线性刚度隔振系统随机动力学特性研究

针对随机激励环境,同时引入刚度和阻尼非线性来提高隔振系统的隔振性能.刚度和阻尼非线性分别是由水平弹簧和水平阻尼的几何布置获得.通过求解Fokker-Planck-Kolmogorov(FPK)方程等效非线性随机振动方程来研究非线性隔振系统在随机激励下的隔振性能,并使用路径积分和Monte-Carlo数值方法进行验证.在此基础上研究刚度非线性和阻尼非线性对隔振系统在随机激励下力传递率及其概率分布的影响.研究表明随着噪声强度的增加,非线性阻尼抑制振动的能力增强,但是在较小的随机激励下线性阻尼优于非线性阻尼.     

Initial-boundary value problem for higher dimensional landau–lifshitz systems

This article is concerned with the partial regularity of the weak solutions satisfying energy inequality and monotonicity inequality to the initial-boundary value problem of Landau–Lifshitz system of ferromagnetic spin chain with Gilbert damping in higher dimensions. A generalized monotonicity inequality is derived. The singular set and its Hausdorff dimension are discussed.     

一类分形函数的Weyl-Marchaud分数阶导数的Hausdorff维数

首先介绍广义Weierstrass型函数的Weyl-Marchaud分数阶导数,得到了带随机相位的广义Weierstrass型函数的Weyl-Marchaud分数阶导数图像的Hausdorff维数,证明了该分形函数图像的Hausdorff维数与Weyl-Marchaud分数阶导数的阶之间的线性关系.     

Diophantine approximation on rational quadrics

We compute the Hausdorff dimension of sets of very well approximable vectors on rational quadrics. We use ubiquitous systems and the geometry of locally symmetric spaces. As a byproduct we obtain the Hausdorff dimension of the set of rays with a fixed maximal singular direction, which move away into one end of a locally symmetric space at linear depth, infinitely many times.     

非自治的Schrdinger方程的吸引子

研究2维的非自治非线性Schrdinger方程长时间的动力学行为,证明了一致吸引子的存在性,并给出了该一致吸引子Hausdorff维数的上界,     

Characterization of a coherent upper conditional prevision as the Choquet integral with respect to its associated Hausdorff outer measure

A model of coherent upper conditional prevision for bounded random variables is proposed in a metric space. It is defined by the Choquet integral with respect to Hausdorff outer measure if the conditioning event has positive and finite Hausdorff outer measure in its Hausdorff dimension. Otherwise, when the conditioning event has Hausdorff outer measure equal to zero or infinity in its Hausdorff dimension, it is defined by a 0–1 valued finitely, but not countably, additive probability. If the conditioning event has positive and finite Hausdorff outer measure in its Hausdorff dimension it is proven that a coherent upper conditional prevision is uniquely represented by the Choquet integral with respect to the upper conditional probability defined by Hausdorff outer measure if and only if it is monotone, comonotonically additive, submodular and continuous from below.     

The hausdorff dimension of the sample path of a subordinator

The Hausdorff dimension of the range of an arbitrary subordinator is exactly determined in terms of the rate of linear drift and the Levy measure of the subordinator. This generalizes the result of Blumenthal and Getoor: that for a stable subordinator of indexσ, the dimension of the range isσ.     

The set of stable switching sequences for discrete-time linear switched systems

In this paper we study the characterization of the asymptotical stability for discrete-time switched linear systems. We first translate the system dynamics into a symbolic setting under the framework of symbolic topology. Then by using the ergodic measure theory, a lower bound estimate of Hausdorff dimension of the set of asymptotically stable sequences is obtained. We show that the Hausdorff dimension of the set of asymptotically stable switching sequences is positive if and only if the corresponding switched linear system has at least one asymptotically stable switching sequence. The obtained result reveals an underlying fundamental principle: a switched linear system either possesses uncountable numbers of asymptotically stable switching sequences or has none of them, provided that the switching is arbitrary. We also develop frequency and density indexes to identify those asymptotically stable switching sequences of the system.     

On the fractional calculus of Besicovitch function

Relationship between fractional calculus and fractal functions has been explored. Based on prior investigations dealing with certain fractal functions, fractal dimensions including Hausdorff dimension, Box dimension, K-dimension and Packing dimension is shown to be a linear function of order of fractional calculus. Both Riemann–Liouville fractional calculus and Weyl–Marchaud fractional derivative of Besicovitch function have been discussed.