共查询到20条相似文献,搜索用时 15 毫秒
1.
Considernonlinearalmostperiodicdiferentialequationx=A(t)x(t)+f(t,x(t))(1)anditshomogeneouslineardiferentialequationx(t)=A(t)x... 相似文献
2.
刘晓建 《高等学校计算数学学报》1997,19(2):122-131
本文将考虑一类最高阶导数项前含有小参数ε的空间方向为二维的对流—扩散方程的一致精度的差分格式,分三部进行讨论。 1 连续问题 我们考虑下面的对流—扩散方程 相似文献
3.
一类高维滞后型泛函微分方程的周期解 总被引:21,自引:0,他引:21
本文研究一类滞后型函数分方程的周期解问题,利用指数型二分性和不动点定理,在较广泛的条件下证明了该方程的周期解的存在性及唯一性,推广并改进了文[1-3]的主要结果 相似文献
4.
Wu Xiaofei Sun Liyan 《Annals of Differential Equations》2007,23(2):218-224
This paper,using the theory of exponential dichotomy and fixed point theo- rem,discusses the existence of periodic solution for a class of neutral higher dimensional differential system with delay,the result extends and improves the result of paper[6]. 相似文献
5.
ONTHEEXISTENCEOFPERIODICSOLUTIONOFHIGHERORDERPERIODICSYSTEM(王全义)华侨大学,邮编:362011WangQuanyi(HuaqiaoUniversity)Abstract:Inthispap... 相似文献
6.
利用Banach空间压缩不动点定理和微分不等式的分析技巧,研究一类具分布时滞的Hopfield神经网络模型的概周期解的存在性和稳定性。得到了系统存在概周期和全局指数稳定的新的充分条件。所得结果改进和推广了相关文献的结论。 相似文献
7.
Xie Huiqin 《Annals of Differential Equations》2005,21(1):65-72
In this paper, we study the problem of almost periodic solution for the cellular neural networks with variable coefficients and delays. By ingeniously importing real parameters di > 0(i = 1,2,…n) which can be adjusted, we establish some sufficient conditions which ensure the neural networks exist a unique almost periodic solution, and all other solutions exponentially converge to such an almost periodic solution. 相似文献
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In this paper, we study the existence, uniqueness, and the global exponential stability of the periodic solution and equilibrium of hybrid bidirectional associative memory neural networks with discrete delays. By ingeniously importing real parameters di > 0 (i = 1,2, …, n) which can be adjusted, making use of the Lyapunov functional method and some analysis techniques, some new sufficient conditions are established. Our results generalize and improve the related results in [9]. These conditions can be used both to design globally exponentially stable and periodical oscillatory hybrid bidirectional associative neural networks with discrete delays, and to enlarge the area of designing neural networks. Our work has important significance in related theory and its application. 相似文献
10.
Deng Chunhong Feng Chunhua 《Annals of Differential Equations》2006,22(2):149-153
By means of the fixed point theorem and exponential dichotomy, in this paper we investigate the existence of almost periodic solutions to a class of n-dimensional almost periodic systems, which is more general than the systems in [1-2]. We generalize and improve some results in [3]. 相似文献
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微分方程的指数稳定性 总被引:1,自引:0,他引:1
比较系统地研究了It方程解的指数稳定性.给出了随机指数稳定性、指数P-稳定性、几乎必然指数稳定性的比较准则,这些比较准则推广了Nevel’son和Has’minskiǐ的相应结果. 相似文献
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15.
Imre Kátai 《Acta Mathematica Hungarica》2006,112(3):221-225
Summary Let <InlineEquation ID=IE"1"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"2"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"3"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"4"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"5"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"6"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"7"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"8"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"9"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"10"><EquationSource Format="TEX"><![CDATA[<InlineEquation
ID=IE"11"><EquationSource Format="TEX"><![CDATA[<InlineEquation ID=IE"12"><EquationSource Format="TEX"><![CDATA[$]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>$]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>]]></EquationSource></InlineEquation>
S(x,\alpha\mid X_p):=\sum_{\substack{p_1p_2<x\\ p_1<p_2}} X_{p_1}X_{p_2}e^{2\pi i\alpha p_1p_2},\qquad \pi_2(x)=\sum_{\substack{p_1p_2<x\ p_1<p_2}} 1, $$ where $p$, $p_1$, $p_2$ run over the prime numbers. It is proved that $$ \max_{\substack{|X_p|\le 1\\ p}}
\frac{{S(x,\alpha,X_p)}}{{\pi_2(x)}} =\Delta(x,\alpha)\to 0\qquad(x\to\infty) $$ for almost all irrational $\alpha$. 相似文献
16.
Robert M. Oliver 《Operations Research Letters》1984,3(3):111-117
Some new insights and results for exponential smoothing with application to forecasting and parameter estimation. Multidimensional exponential smoothing is described by a Kalman filter model with a limiting stationary gain matrix. 相似文献
17.
非光滑多目标规划非控解和真有效解 总被引:5,自引:0,他引:5
考虑问题(P) (?)其中 f(x)=(f_1(x),…,f_m(x))~T,g(x)=(g_1(x),…,g_l(x))~T,C 是 n 维欧氏空间 E_n中的闭集,f_i(x)(i=1,…,m)和 g_j(x)(j=1,…,l)为在 C 的某个邻域中的 Lipschitz函数,D 为 E_l 中的闭凸锥。记R={x|g(x)∈D,x∈C}。设 A 为 E_m 中的非零凸锥。(?)∈R 称为 f(x)(对 A)的非控解,若不存在 x∈R 使 相似文献
18.
Pierre De La Harpe 《Geometriae Dedicata》2002,95(1):1-17
This is an exposition of examples and classes of finitely-generated groups which have uniform exponential growth. The main examples are non-Abelian free groups, semi-direct products of free Abelian groups with automorphisms having an eigenvalue of modulus distinct from 1, and Golod–Shafarevich infinite finitely-generated p-groups. The classes include groups which virtually have non-Abelian free quotients, nonelementary hyperbolic groups, appropriate free products with amalgamation, HNN-extensions and one-relator groups, as well as soluble groups of exponential growth. Several open problems are formulated. 相似文献
19.
Let a and b given unequal positive integers; it is desired to determine the positive integer solutions n and x of the equation
of the title. Some special cases have recently been considered, and here some general results and conjectures are presented.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
Given a large square real matrix A and a rectangular tall matrix Q, many application problems require the approximation of the operation . Under certain hypotheses on A, the matrix preserves the orthogonality characteristics of Q; this property is particularly attractive when the associated application problem requires some geometric constraints to be satisfied. For small size problems numerical methods have been devised to approximate while maintaining the structure properties. On the other hand, no algorithm for large A has been derived with similar preservation properties. In this paper we show that an appropriate use of the block Lanczos method allows one to obtain a structure preserving approximation to when A is skew-symmetric or skew-symmetric and Hamiltonian. Moreover, for A Hamiltonian we derive a new variant of the block Lanczos method that again preserves the geometric properties of the exact scheme. Numerical results are reported to support our theoretical findings, with particular attention to the numerical solution of linear dynamical systems by means of structure preserving integrators. AMS subject classification (2000) 65F10, 65F30, 65D30 相似文献