线性约束下部分线性模型中估计的渐近性质

考虑回归模型yi=x′iβ+ g(ti) + ei, 0 ≤i ≤nr=Rβ其中(xi,ti)是固定非随机设计点列,xi=(xi1,…,xip)′,β=(β1,…,βp)′(p 1) ,g是定义在[0 ,1]上的未知函数,β是未知待估参数,0≤ ti≤1i,ei 是i.i.d随机误差,且Eei=0 ,Ee2i=σ2 <∞.r是一个J维向量,R是一个J* p列满秩矩阵,基于g的估计取一个非参数权估计,本文讨论了在线性约束下β的最小二乘估计的相合性及渐近正态性.     

半参数回归模型的误差方差的小波估计

考虑半参数回归模型y i=x i' β +g(t i)+e i,1 i n,其中β∈R d为未知参数,g(t)为[0,1]上的未知Borel函数,x i为R d上的随机设计, {e i}为i.i.d.随机误差. 本文构造了误差方差σi 2=var (e i)的小波估计 n 2,得到了 n 2的渐近正态性, 同时构造了var(e i 2)的小波估计 n 2,并且证明了 n 2的弱相合性, 由此可知 依分布收敛于N(0,1), 这一结果可用于构造σ 2的大样本区间估计或对σ 2进行大样本检验.     

一类混合回归模型中估计的收敛速度

考虑回归模型y_i=x_iβ+g(t_i)+e_4,i=1,2,…,n,其中 g(·)是未知光滑函数,β是未知待估参数,e_4是随机误差.设{(x_4,t_4,y_4),1≤i≤n}是 i.i.d.子样.本文首先给出了 g(·)的一类近邻估计n(·),然后基于模型 y_4=x_4β+(t_4)+e_4得到了β的最小二乘估计.在适当条件下,证得了及 g(·)的最终估计(·)的强弱收敛速度.     

半参数回归模型的渐近有效L-估计

对半参数回归模型yi=χiTβ+g(χi)+ei,i=1,2,…,n,对非参数函数g(·)采用核估计的方法,构造了参数向量β的L-估计量λn,在一些正则条件下,获得了λn的渐近正态性和非参数函数g(·)的估计量gn(t)的最优收敛速度可达到O(n-(1/3)),并且给出了标准化L估计量λn的渐近分布的Berry-Esseen界.     

基于M—估计的误差密度估计

对于线性模型 Yi=x＇_iβ十e_i,i=1,2,...,{e_i}_(i= 1)~∞i.i.d.,e_1有未知密度函数f（x）,本文基于β的M-估计的残差:e_i=Yi—x＇_iβ,i=1,2,…,n,其中β为β的M-估计,用 f_n(x)=1/2na_n sum from i=1 to n I(x-a_ne_i^≤x a_n)估计f(x）,得到了这种估计的强收敛速度,一致强收敛速度,L_1-模相合性,渐近正态性,重对数律。     

部分线性模型中参数估计的Bootstrap逼近

考虑回归模型 :yi=xiβ+g(ti) +σiei,1≤ i≤ n.其中 σ2i=f(ui) ,(xi,ti,ui)是固定非随机设计点列 ,f (· )和 g(· )是未知函数 ,β是待估参数 ,ei 是随机误差 .对文 [1 ]给出的基于 g(· )及 f(· )的一类非参数估计的β的最小二乘估计β^ n和加权最小二乘估计βn,本文通过重抽样的方法构造了 β^n 和 βn 的 Bootstrap统计量 β^ *n 和 β*n .证明了在给定原样本的条件下 ,n (β^ *n -β^ n)和 n (β*n -β^ n)分别与 n (β^ n-β)和 n (βn-β)有相同的渐近分布 .     

带有异方差的部分线性回归模型的B样条估计

考虑一带有异方差的固定设计部分线性回归模型yij=X'ijβ+g(tij)+εij,i=1,2…,k:j=1,2,…,ni,和sum from i=1 to kni=n,其中yij为响应变量,β=(β1,…,βp)’是未知的参数向量,g(·)是未知的函数,Xij=(Xij1,…,Xijp)’和tij∈[0,1]为已知的非随机设计点,εij为均值0,方差是σi2的随机误差,其中σi2可能不同.通过B样条级数近似非参数分量,构造了参数分量β的一个半参数广义最小二乘估计.在一些矩条件下,导出了此半参数广义最小二乘估计的渐近分布,大多数在实际中遇到的误差分布都满足这些矩条件.另外,也构造了半参数广义最小二乘估计的渐近协方差矩阵的一个相合估计,还讨论了非参数分量的B样条估计.所有这些大样本性质都是在k趋于无穷大,ni有限时导出的.这些结果能被用来做渐近有效的统计推导.     

一类混合回归模型中估计的收敛速度

考虑回归模型 y_i=x_iβ+g(t_i)+e_i,i=1,2,…n,其中g(·)是未知光滑函数,β是未知待估参数,e_i是随机误差。 设{(x_i,t_i,y_i,),1≤i≤n}是i.i.d.子样。本文首先给出了g(·)的一类近邻估计■_n(·),然后基于模型y_i=x_iβ+■_n(t_i),+e_i得到了β的最小二乘估计■_n。在适当条件下,证得了■_n及g(·)的最终估计■_n~■(·)的强弱收敛速度。     

半参数回归模型的误差方差的小波估计

考虑半参数回归模型yi=Xi'β＋g（ti）＋ei,1≤i≤n,其中β∈Rd为未知参数,g（t）为[0,1]上的未知Borel函数,xi为Rd上的随机设计,{ei}为i.i.d．随机误差本文构造了误差方差σi2=var（ei）的小波估计■,得到了■的渐近正态性,同时构造了var(ei2)的小波估计■,并且证明了■的弱相合性,由此可知■依分布收敛于N（0,1）,这一结果可用于构造σ2的大样本区间估计或对σ~2进行大样本检验。     

固定设计的时间序列半参数回归

考虑如下的半参数回归模型Yi=xTiβ+g(ti)+εi(0≤i≤n),其中{εi,0≤i≤n}和{εt,0≤t≤n}有相同的联合分布,{εt,-∞＜t＜∞}是具有零均值和有限方差σ2的严平稳α-混合时间序列.本文构造了上述模型中β,g(t)和σ2的局部多项式估计,在适当的条件下,得到了估计的渐近正态性和收敛速度.在一定的假设下,β的估计是自适应的,而且g(υ)(t)(g(t)的第υ阶导数)的估计的收敛速度是最优的.     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.