共查询到10条相似文献,搜索用时 20 毫秒
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设Y_i=x'iβ+ei,1≤i≤n为线性模型,βn=(βn1,…,βnp)'为β=(β1,…,βp)'的最小二乘估计,以u_n记(sum from i=1 to n(xix'i))的(1,1)元,vn=un-1.证明了在Eei=O且{ei}满足Gauss-Markov条件时,vi→∞及sum from i=2 to ∞(vi-2(vi-vi-1)log~2i<∞)为βn1强相合的充分条件,且对任何εn→0,vi→∞及sum from i=2 to ∞(εivi-2(vi-vi-1)log2i<∞)已不再充分.提出了βn1强相合的一个充要条件,它把βn1强相合归结为正交随机变量级数的收敛问题. 相似文献
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For linear models yj=x′jβ+ej(j=1,…,n,…) satisfying e1,e2,…i.i.d. 相似文献
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Suppose given a linear model yj=x'jβ+μj, j=1,2,…, The random errors all have a mean zero and unknown variance σ2, 0<σ2<∞. Let σn2 be the estimate of σ2 based on the residual sum of squares and calculated from (xj, yj), j=1,…,n. In this paper we show that if μ1,μ2,…, are independent but not necessarily identically distributed, and some further conditions on {μj} and (x1|…|xn) are satisfied, then for any ε>0 there exist constant ρε, 0<ρε<1, Such that P(|σn2-σ2|≥ε)=O(ρεn). 相似文献
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in linear models, the error varianceσ2 of random errors is usually estimat-ted by the residual sum of squares (divided by a su ita ble degree of free-dom), based on the first n observation, (denote it by σn2). it is well known t that under certain conditions, the distribution of this estimate, when standardised, converges to the standard normal distribution. In this paper, it is shown that |Gn(x)-Ф(x)|=O(n-δ/2(1+|x|)-(2+δ)). when the errors are indepedent (maynot be identically distributed) and their 4 + 2δ order moments exist, where Gn(x) is the distribution of (σn2-σ2/(varσn2)1/2,Ф(x)=1/(2π)1/2∫-∞xe-r2/2dt. 相似文献
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A non-flat Riemannian space Vn is called Riemannian space with constant connection if its Christoffel symbols of the second kind are constant in some coordinate system {xi}. Following G. Vranceanu [3], a Riemannian space Vn with constant connection is said to be of genus p, if the components of the fundamental tensor in the coordinate system {xi/sup>} can be written in the form gij=cijata(a=1,…,p) where cija are constant, and p is least.In this paper we prove the following 相似文献
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Let (X,Y) be a Rd×R1-valued random vector with E(|Y|)<∞,m(x)=E(Y|X=x) be the regression funvion of Y with respect to X.Suppose that (Xi, Yi),i=1, …,n, are iid samples drawn from (X,Y). It is desired to estimate m(x) based on these samples,everoye discussed in 1981 (see [2]) the pointwise Lp-convergence of the nearest neigthoor estimate mn(x) (see (5) of the present paper). In this article we further study the rate of this convergence.It is shown that if there exists p≥2 such that E |Y|p<∞,then E|mn(x)-m(x)|p=O(n-p/(d+2))a.s. for suitabte choice of the weighte Cm (see(4) of the present paper). 相似文献
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In this paper we consider the Mean Square Error (MSE) of two uaual estimates of density function f(x) at a point x: The uniform kernel estimate fn(x) and the NN estimate fn(x). we- show that when f is differentiable for sufficiently high order at x. these MSE can be expanded in a form E(fn(x)-f(x))2=A1(x)n-4/5 +A2(x)n-1+A3(x)n-6/5+…;E(fn(x)-f(x))2=B1(x)n-4/5 +B2(x)n-1+B3(x)n-6/5+… And if we suitably choose the parameters in fn and fn to make A1(x) and B1(x)to assume its minimunm value, then we also, have A2(x) =B2(x) but A3(X) differs form B3(X). This result shows that while the two estimates are not identical with respect to MSE. each one can be superior to the other in various special cases. 相似文献
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For Y1, Y2,…i .i .d . with Y1~N(μ, 1) and Sn=(?)Yi, the large deviations are obtained for theprobabilities that(?) conditionally given (i) Sm=0, and (ii) Smi=ξ. Applied these results to the double change points model with some nuisance parameters, we developed the large deviation for the significance level of the likelihood ratio test. 相似文献