首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
定义1^[1]记函数f(x)=f^[1](x),f(f(x))=f^[2](x),…,f(f(…f(x)…))=f^[n](x),f^[n](x)为f(x)的n次迭代.  相似文献   

2.
任哲  胡舒合 《数学杂志》2002,22(3):301-308
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 .  相似文献   

3.
证明lin λ→0∑i=1^nf(ξi)g(θi)△Xi=∫a^bf(x)g(x)dx和limλ→0∑i=1^n√f^2(ξi) g^2(θi)=∫a^b√f^2(x) g^2(x)dx,并将其应用于弧长公式和第一类曲线积分计算公式的证明.  相似文献   

4.
Warsaw圈上映射的等度连续性   总被引:4,自引:0,他引:4  
顾荣宝 《数学研究》2002,35(3):249-256
设W是Warsaw圈:f:W→W是连续映射,本证明f是等度连续映射的充分必要条件是下列两个条件之一成立:(1)F(f)是一个单点集并且F(f^2)=∩^∞n=1f^n(W);(2)F(f)=∩^∞n=1f^n(W)。  相似文献   

5.
误差为鞅差序列的半参数回归模型估计的相合性   总被引:1,自引:0,他引:1  
凌能祥 《工科数学》1999,15(2):71-73
设半参数回归摸型Y^(n)=β·χi(1) g(l1^(n)) 1 ^(n),i=1,2,….n,本由最小二乘法和一般加权方法定义的β、g(t)的怙计量βn,gn(t).在误差为鞅差序列下获得了βn gn(f)的r(≥2)阶平均相合性。  相似文献   

6.
在整数环Z上的二次不定方程不恒有解,而在多项式环R[x]中,对任意首项系数为正数的多项式f(x),必有R[x]中首项系数为正数的多项式g(x),h(x),使得f^2(x)=g^2(x) h^2(x)。  相似文献   

7.
众所周知,将二次函数f(x)=x^2 bx c进行n次迭代,得到f^[n](x),这是个2^n次多项式,函数f(x)有无不动点(即方程f(x)=x有无实根)对方程f^[n](x)=x的解的情况有何影响?本文拟对此进行一些探索,在本文中,我们规定f^[0](x)=x。  相似文献   

8.
讨论由f(x)和f^(n 1)(x)的性质来决定f‘(x),f‘‘(x)……f(n)(x)的相应性质,得到几个结论璧如:设f(x)在区间(a, ∞)有直到(n 1)阶的导数,那么当limx→ ∞f(x)=0且limx→ ∞f^(n 1)(x)=0时,必有limx→ ∞f(x)=0……limx→ ∞f^(n)(x)=0  相似文献   

9.
向量值Nevanlinna第二基本定理的余项S(r)的估计   总被引:2,自引:1,他引:1  
张丹萍 《工科数学》1999,15(1):28-35
首先通过建立并证明推广的对数导数基本引理。讨论了1/2n∫^2n0 ‖f^1(re^iθ)‖/‖f(re^iθ)‖dθ的增长问题,进而对向量Nevanlinna第二基本定理的余项进行了估计。  相似文献   

10.
定义1 记函数f(x)=f^{1}(x),f(f(x))=f^{2}(x),…,f(f(…f(x)…))=f^{n}(x),f^{n}(x)为f(x)的n次迭代.  相似文献   

11.
12.
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.  相似文献   

13.
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.  相似文献   

14.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

18.
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].  相似文献   

19.
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.  相似文献   

20.
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  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号