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81.
82.
考虑随机系数自回归模型Yt =Φtyt-1+ ut,其中 Φt为随机系数,ut为随机误差。在允许Φt与ut相依以及Eut无穷的条件下,构造了误差方差的自加权估计,并证明了该估计的渐近正态性。最后通过数值模拟,说明
自加权估计的稳健和有效性。 相似文献
83.
Meirong Xu 《Applied mathematics and computation》2010,217(1):441-449
In this paper, we study the difference equation:
84.
Helga Baum 《Journal of Geometry and Physics》1987,4(4):503-522
Let
(P) be the moduli space of irreducible connections of a G-principal bundle P over a closed Riemannian spin manifold M. Let DA be the Dirac operator of M coupled to a connection A of P and f a smooth function on M. We consider a smooth variation A(u) of A with tangent vector ω and denote Tω:=
(DA(u)−f) (u=0. The coefficients of the asymptotic expansion of trace (Tω · e-t(DA−f)2) near t=0 define 1-forms a(k)f, K=0, 1, 2, … on
(P). In this paper we calculate aa(0)f, a(1)f, a(2)f and study some of their properties. For instance using the 1-form a(2)f for suitable functions f we obtain a foliation of codimension 5 of the space of G-instantons of S4. 相似文献
85.
Masayuki Kumon 《Annals of the Institute of Statistical Mathematics》1992,44(2):239-260
The present paper treats the identification of parametric nonminimum phase transfer function. We propose a method of identification based on the inner outer factorization of stable transfer function. It consists of identifying the outer and inner parts of a transfer function separately. The outer part is identified by the use of the second-order spectral estimate from the observed linear process, while the inner part is identified by the use of a higher-order cumulant spectral estimate from the observed process. Respective parameter estimators are determined in the light of asymptotic efficiency. In order to estimate the order of the inner part of a transfer function, a criterion is proposed. It is introduced based on the same principle as in the case of Akaike's AIC. 相似文献
86.
Representation theorem and local asymptotic minimax theorem are derived for nonparametric estimators of the distribution function on the basis of randomly truncated data. The convolution-type representation theorem asserts that the limiting process of any regular estimator of the distribution function is at least as dispersed as the limiting process of the product-limit estimator. The theorems are similar to those results for the complete data case due to Beran (1977, Ann. Statist., 5, 400–404) and for the censored data case due to Wellner (1982, Ann. Statist., 10, 595–602). Both likelihood and functional approaches are considered and the proofs rely on the method of Begun et al. (1983, Ann. Statist., 11, 432–452) with slight modifications.Division of Biostatistics, School of Public Health, Columbia Univ. 相似文献
87.
Let {Xt} be a Gaussian ARMA process with spectral density fθ(λ), where θ is an unknown parameter. The problem considered is that of testing a simple hypothesis H:θ = θ0 against the alternative A:θ ≠ θ0. For this problem we propose a class of tests
, which contains the likelihood ratio (LR), Wald (W), modified Wald (MW) and Rao (R) tests as special cases. Then we derive the χ2 type asymptotic expansion of the distribution of T
up to order n−1, where n is the sample size. Also we derive the χ2 type asymptotic expansion of the distribution of T under the sequence of alternatives An: θ = θ0 + /√n, ε > 0. Then we compare the local powers of the LR, W, MW, and R tests on the basis of their asymptotic expansions. 相似文献
88.
我们考虑空间上一粒子系统,当其受到分布于求面上的介质作进行粒子分枝和衍生,产生新了体,而新粒子仍按原粒子的运动规则继续空间运动。通过合理的假设和极限过程,粒子在空间的散布一测度值分枝过程来刻划。 相似文献
89.
For an l x k matrix A = (aij) of integers, denote by L(A) thesystem of homogenous linear equations ai1x1 + ... + aikxk =0, 1 i l. We say that A is density regular if every subsetof N with positive density, contains a solution to L(A). Fora density regular l x k matrix A, an integer r and a set ofintegers F, we write
if for any partition F = F1 ... Fr there exists i {1, 2,..., r} and a column vector x such that Ax = 0 and all entriesof x belong to Fi. Let [n]N be a random N-element subset of{1, 2, ..., n} chosen uniformly from among all such subsets.In this paper we determine for every density regular matrixA a parameter = (A) such that limn P([n]N (A)r)=0 if N =O(n) and 1 if N = (n). 1991 Mathematics Subject Classification:05D10, 11B25, 60C05 相似文献
90.
N.M. Temme 《Numerical Algorithms》1997,15(2):207-225
Airy-type asymptotic representations of a class of special functions are considered from a numerical point of view. It is well known that the evaluation of the coefficients of the asymptotic series near the transition point is a difficult problem. We discuss two methods for computing the asymptotic series. One method is based on expanding the coefficients of the asymptotic series in Maclaurin series. In the second method we consider auxiliary functions that can be computed more efficiently than the coefficients in the first method, and we do not need the tabulation of many coefficients. The methods are quite general, but the paper concentrates on Bessel functions, in particular on the differential equation of the Bessel functions, which has a turning point character when order and argument of the Bessel functions are equal. 相似文献