具有多项式增长系数的随机延迟微分方程的整体解与矩估计

本文用Ito公式和Lyapunov函数法为具有多项式增长系数的随机延迟微分方程的整体解的存在和矩有界给出一个充分的条件.此条件适用于无限时滞的随机系统,对于有限时滞的随机系统也成立.     

具弱非线性耗散的Bresse系统解的能量衰减

本文研究了一维有界区域上三个波动方程都具有非线性阻尼的Bresse系统解的能量衰减估计.利用乘子法,通过一个加权积分不等式,证明了该Bresse系统解的能量衰减估计,这类非线性阻尼在原点有多项式增长阶,但不要求等速波传播条件.     

一般多项式有界算子的泛函表示定理

该文在圆盘代数A(D)中引入了一个数乘变换, 找到了多项式有界算子的多项式演算与Riesz函数演算之间的联系, 得到了Banach空间X上的一般多项式有界算子的泛函表示定理.     

中立型随机延迟微分方程分裂步θ方法的强收敛性

中立型随机延迟微分方程常出现在一些科学技术和工程领域中.本文在漂移系数和扩散系数关于非延迟项满足全局Lipschitz条件,关于延迟项满足多项式增长条件以及中立项满足多项式增长条件下,证明了分裂步θ方法对于中立型随机延迟微分方程的强收敛阶为1/2.数值实验也验证了这一理论结果.     

推广的Kantorovich多项式算子在L-p[0,1](1≤p)中的一个局部逆定理

本文在引进了推广的Kantorovich多项式算子的条件下,假设｛αn｝有界得到了该算子在逼近过程中的局部逆定理,从而推广了文献[1]中Z．Ditzian的结果．     

广义解的Pohozaev恒等式及其应用

本文我们证明了二阶椭圆型方程组控制增长条件下的广义解及自然增长条件下的连续广义解的Pohozaev型恒等式.作为应用,我们给出了自然增长二次泛函的W_o~(1,2)极小点有界或连续在某种意义下的充分必要条件.另外还给出了在调和映射中的一个应用.     

勒让德方程的有界解问题

勒让德多项式P_n(x)为勒让德方程的有界解,而其方程的一切有界解可表为AP_n(x)(A 为一常数因子),对这一命题给出一个简便的证明.     

一类调和多项式与Poisson核乘积的积分及增长性

本文研究了半空间上的一类调和多项式与Poisson核的乘积的积分及其增长性问题.通过利用已知的收敛条件重新定义测度的方法和相应的增长估计,获得了一类调和多项式与Poisson核乘积的积分的增长性质,推广了关于Poisson积分的结果.     

一个求解P*(k)水平线性互补问题精确极大互补解的不可行内点算法

Stoer,Wechs,和Mizuno最近提出了一个求解P*(k)水平线性互补问题的不可行内点算法,他们的算法能在有限不内得到问题的一个精确解,但是没有讨论算法的多项式复杂性.本文提出一个能得到P*(k)水平线性互补问题精确极大互补解的不可行内点算法,通过使用条件数和误差界理论,我们证明了所给算法是多项式有界的.     

推广的Kantorovich多项式算子在Lp[0,1](1≤P)中的一个局部逆定理

本文在引进了推广的Ｋａｎｔｏｒｏｖｉｃｈ多项式算子的条件下,假设（ａｎ）有界得到了该算子在逼近过程中的局部逆定理,从而推广了文献「１」中Ｚ－Ｄｉｔｚｉａｎ的结果。     

Study of the blow-up of solutions of systems of equations of hydrodynamic type

Mathematical Notes - We study the initial boundary-value problem for three-dimensional systems of equations of pseudoparabolic type. The system is similar to the Oskolkov system, but differs from...     

Distribution of types of symmetry of tensors of high degree

The asymptotic distribution of tensors of degree N in symmetry types is studied in this paper.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 155, pp. 181–186, 1986.     

Axiomatizability of reducts of algebras of relations

In this paper, we prove that any subreduct of the class of representable relation algebras whose similarity type includes intersection, relation composition and converse is a non-finitely axiomatizable quasivariety and that its equational theory is not finitely based. We show the same result for subreducts of the class of representable cylindric algebras of dimension at least three whose similarity types include intersection and cylindrifications. A similar result is proved for subreducts of the class of representable sequential algebras. Received October 7, 1998; accepted in final form September 10, 1999.     

Characterization of types of asymptotic discernibility of families of hypotheses

We give a characterization of the types of asymptotic discernibility of families of hypotheses in the case of hypothetical measures that are not, in general, mutually absolutely continuous. The case when the logarithm of the likelihood ratio admits an asymptotic expansion of the type of an expansion with local asymptotic normality is examined in detail. Examples are studied.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 64–71, 1987.     

Lengths of periods of continued fractions of square roots of integers

Empirical study of the period’s length T of the continued fractions of $\sqrt{Q}$ (for growing integers Q) shows several strange asymptotical results, for instance, $T\leq C\sqrt{Q}\ln{Q}$ . These results show important differences between the statistics of the elements of the continued fractions of random real numbers and of square roots of random integers.