一类非线性发展方程的全局解的存在性(英文)

本文证明了一类非线性发展方程全局解的存在性,并证明适当假设下,当非线性项满足临界指数增长条件时,方程具有紧吸引子。     

时滞型脉冲神经网络的全局指数稳定性

对一类含时滞的脉冲神经网络平衡点的存在性和稳定性进行了研究．在不假定激励函数有界、单调或可微而仅假定激励函数Lipschitz连续的条件下,利用压缩映像原理证明了系统平衡点的存在性,利用右上Dini导数的性质并通过构造适当的gyapunov函数得到了平衡点全局指数稳定的充分条件．文末通过实例说明了所获结论的有效性．     

具有扭转耦合效应的复合薄壁梁黎斯基的性质和指数稳定性(英文)

研究了具有扭转耦合效应的复合薄壁梁黎斯基的性质以及指数稳定性.首先证明该系统决定算子的预解式是紧的,且可生成群.其次,通过对该系统算子谱的渐近分析,证明了除至多有限个本征值外,其算子的谱是单重可分离的.特殊地,我们获得了自由系统的频率渐近表达式,因而利用克尔德什定理,证明了在希尔伯特状态空间中算子广义本征函数列的完备性.最后,结合黎斯基的性质及算子谱的分布证明了该系统的指数稳定性.     

最短区间估计问题研究

给出了正态分布总体及指数分布总体在给定置信水平下参数的最短区间估计.为便于实际工作者的应用,文章给出了计算用表.     

具有时滞的抑制细胞神经网络的周期解的存在性和全局指数稳定性

By using the Leray-Schauder fixed point theorem,differential inequality techniques and constructing suitable Lyapunov functional,several sufficient conditions are obtained for the existence and global exponential stability of periodic solutions for general shunting inhibitory cellular neural networks with delays.Some new results are obtained and some previously known results are improved.An example is employed to illustrate our feasible results.     

A random transport-diffusion equation

In this paper we study the integral curve in a random vector field perturbed by white noise. It is related to a stochastic transport-diffusion equation. Under some conditions on the covariance function of the vector field, the solution of this stochastic partial differential equation is proved to have moments. The exact p-th moment is represented through integrals with respect to Brownian motions. The basic tool is Girsanov formula.     

指数时程差分与有理谱配点法求解奇异摄动Burgers-Huxley问题

带小参数ε的Burgers-Huxley方程是一类非线性、非定常奇异摄动初边值问题,本文用指数时程差分与有理谱配点法求其数值解.对空间方向的边界层,用带sinh变换的有理谱配点法便Chebyshev节点在边界层处加密,只需取较少节点即可达到较高精度;时间方向采用指数时程差分与4阶Runge-Kutta法相结合的格式,并用围线积分计算矩阵甬数的方法克服了求解奇异摄动问题时遇到的的数值不稳定堆题.数值实验表明,本文提出的方法在求解左、右边界层和内部层的奇异摄动Burgers-Huxley问题都有较高的精度.     

More on regular and decomposable ultrafilters in ZFC

We prove, in ZFC alone, some new results on regularity and decomposability of ultrafilters; among them: (a) If m ≥ 1 and the ultrafilter D is (_m(λ⁺ⁿ), _m(λ⁺ⁿ))‐regular, then D is κ ‐decomposable for some κ with λ ≤ κ ≤ 2^λ (Theorem 4.3(a^')). (b) If λ is a strong limit cardinal and D is (_m(λ⁺ⁿ), _m(λ⁺ⁿ))‐regular, then either D is (cf λ, cf λ)‐regular or there are arbitrarily large κ < λ for which D is κ ‐decomposable (Theorem 4.3(b)). (c) Suppose that λ is singular, λ < κ, cf κ ≠ cf λ and D is (λ⁺, κ)‐regular. Then: (i) D is either (cf λ, cf λ)‐regular, or (λ^', κ)‐regular for some λ^' < λ (Theorem 2.2). (ii) If κ is regular, then D is either (λ, κ)‐regular, or (ω, κ^')‐regular for every κ^' < κ (Corollary 6.4). (iii) If either (1) λ is a strong limit cardinal and λ^<λ < 2^κ, or (2) λ^<λ < κ, then D is either λ ‐decomposable, or (λ^', κ)‐regular for some λ^' < λ (Theorem 6.5). (d) If λ is singular, D is (μ, cf λ)‐regular and there are arbitrarily large ν < λ for which D is ν ‐decomposable, then D is κ ‐decomposable for some κ with λ ≤ κ ≤ λ^<μ (Theorem 5.1; actually, our result is stronger and involves a covering number). (e) D × D^' is (λ, μ)‐regular if and only if there is a ν such that D is (ν, μ)‐regular and D^' is (λ, ν^')‐regular for all ν^～ < ν (Proposition 7.1). We also list some problems, and furnish applications to topological spaces and to extended logics (Corollar‐ies 4.6 and 4.8) (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

随机选择修理工的可修复系统指数稳定性分析

讨论了一个随机选择修理工的可修复系统解的指数稳定性,首先通过对积分微分方程组描述的可修复系统生成的系统算子的本质谱的增长性约束和扰动后本质谱半径的变化情况进行分析,进而得到了可修复系统解的指数稳定性.     

随机指数系的完备性和极小性

得到了随机指数系在加权Banach空间C_α中完备和极小的充要条件,其中C_α是实直线R上的复连续函数在权α的一致范数下组成的Banach空间.这些结果可以看作是Malliavin经典结果的概率推广.