Some estimations for nilpotence of nill-algebras over a field of an arbitrary characteristic and height theorem

In this paper are obtained some estimations for nilpotence degree of nill-algebras over a field of an arbitrary characteristic and for height in Shirshovs sense. These estimations are exponential.     

并联压力—强度模型可靠性研究

In this paper,the reliability of a parallel stress-strength model of exponentiated Pareto distribution is discussed.Different point estimations and interval estimations are proposed.The point estimators obtained are maximum likelihood and Bayesian estimators.The interval estimations obtained are approximate,exact,bootstrap-p and bootstrap-t confidence intervals and Bayesian credible interval.Different methods and the corresponding confidence intervals are demonstrated using some simulation studies.     

系数为梯形模糊数的模糊回归分析的最小二乘法

由于模糊数往往可以用梯形模糊数来逼近,因此对梯形模糊数的模糊回归模型的研究就有一定的实用价值.采用最小二乘的方法,针对输入为精确数、输出和回归系数都是梯形模糊数的模糊线性回归模型,讨论了该模型回归系数的最小二乘估计及误差项的估计,实例说明了提出的参数估计的拟合度比较好.     

三参数对数正态分布的参数估计

本文讨论了三参数对正态分布的参数估计问题，指出了最小二乘估计存在的问题，并提出了两种修改的最小二乘估计，模拟研究表明，这种估计较以前提出的估计有一定的优点。     

二维RLW方程的Cauchy问题

通过椭圆积分求出了二维RLW方程椭圆余弦波解,并用先验估计方法证明了该方程Cauchy问题关于小x、y周期解的若干性质和解的唯一性、稳定性。     

On Approximation by Neural Networks with Optimized Activation Functions and Fixed Weights

Recently, Li [16] introduced three kinds of single-hidden layer feed-forward neural networks with optimized piecewise linear activation functions and fixed weights, and obtained the upper and lower bound estimations on the approximation accuracy of the FNNs, for continuous function defined on bounded intervals. In the present paper, we point out that there are some errors both in the definitions of the FNNs and in the proof of the upper estimations in [16]. By using new methods, we also give right approximation rate estimations of the approximation by Li’s neural networks.     

The retraction constant in some Banach spaces

We give new sharper estimations for the retraction constant in some Banach spaces.     

Two-weighted estimations for the Hardy-Littlewood maximal function in ideal Banach spaces

We give conditions on a couple of ideal Banach spaces with weights which are both necessary and sufficient for the Hardy-Littlewood maximal function to satisfy the two-weighted estimations of weak type, and we consider a modification of the Hardy-Littlewood maximal function. We also give some conditions on weights in order for the Hardy-Littlewood maximal function and the modification under consideration to fulfil the two-weighted estimations of strong type.

     

两类螺形映照扩充子族的偏差上界估计

偏差估计一直是多复变函数论的研究热点之一.但目前螺形映照扩充子族的偏差估计的研究成果还较少.针对这一问题,研究了复向量空间C_n中开单位球B_n,复Banach空间中单位球B和域Ω_(p_1,…,p_n)上一类α次β型,α次强β型螺形映照的偏差估计问题.利用不等式、矩阵及两类映照的增长定理等方法,获得了上述域上的两种映照的偏差上界估计,所得结果推广了一些已知的结论.     

Numerical Solution of the Reaction-Diffusion Equation

In this paper, we consider the numerical solution for the reaction-diffusion equation. A finite difference scheme and the basic error equality are given. Then the error estimations are proved for the periodic problem with $v(x,t)\geq 0$, the first and second boundary value problems with $v(x,t)\geq v_0＞0$, and for $v(U)\geq v_0›0$. Under some conditions such estimations imply the stabilities and convergences of the schemes.     

On explicit conditions for the asymptotic stability of linear higher order difference equations

We derive some explicit sufficient conditions for the asymptotic stability of the zero solution in a general linear higher order difference equation, and compare our estimations with other related results in the literature. Our main result also applies to some nonlinear perturbations satisfying a kind of sublinearity condition.     

On the spectral radius of a nonnegative centrosymmetric matrix

In this paper, we discuss the spectral radius of nonnegative centrosymmetric matrices. By using the centrosymmetric structure, we establish some estimations of the spectral radius.     

SOME ESTIMATIONS FOR DETERMINANT OF THE HADAMARD PRODUCT OF H-MATRICES

In this paper,some new results on the estimations of bounds for determinant ofHadamard Product of two H-matrices are given.Several recent results are improved andgeneralized.     

一个有效估计:半参数非时齐扩散模型的局部线性复合分位回归估计

主要研究半参数非时齐扩散模型的参数估计问题.基于非时齐扩散模型的离散观测样本,首先得到漂移参数的局部线性复合分位回归估计,并证明估计量的渐近偏差、渐近方差和渐近正态性.其次,讨论了带宽的选择和局部线性复合分位回归估计关于局部线性最小二乘估计的渐近相对效,所得到的局部估计较局部线性最小二乘估计更为有效.最后,通过模拟说明了局部线性复合分位回归估计比局部线性最小二乘估计的模拟效果更好.     

Bilateral approximations for some Aitken-Steffensen-Hermite type methods of order three

We study the local convergence of some Aitken-Steffensen-Hermite type methods of order three. We obtain that under some reasonable conditions on the monotony and convexity of the nonlinear function, the iterations offer bilateral approximations for the solution, which can be efficiently used as a posteriori estimations.     

Kunita-Watanabe inequalities and Tanaka formula for multi-dimensional G-Brownian motion

In this paper, some new properties and interesting estimations of mutual variation process for G-Brownian motion are presented, Kunita-Watanabe inequalities and Tanaka formula for multi-dimensional G-Brownian motion are also obtained.     

优良抽样设计下总体均值的比率估计

当研究目标的实际测量具有不可修复的破坏性或耗资巨大时,有效的抽样设计将是一项重要的研究课题.在统计推断方面,排序集抽样被视为一种更为有效的收集数据的方式.极值排序集抽样(ERSS)是一种改进的排序集抽样.文章在ERSS下研究了总体均值的比率估计.以正态分布为例,比较了简单随机抽样和ERSS下比率估计的相对效率.数值结果表明ERSS下的比率估计优于简单随机抽样下的比率估计.     

The ?ojasiewicz exponent of nondegenerate surface singularities

We give some estimations of the ?ojasiewicz exponent of nondegenerate surface singularities in terms of their Newton diagrams. We also give an exact formula for the ?ojasiewicz exponent of such singularities in some special cases. The results are stronger than Fukui inequality?[8]. It is also a multidimensional generalization of the Lenarcik theorem?[13].     

On estimations of dispersion of ratio block sequences

Using new characteristics of an infinite subset of positive integers we give some estimations of the dispersion of the related block sequence. Supported by VEGA Grant no. 1/4006/07.