Reducing component estimation for varying coefficient models

The estimation problem for varying coefficient models has been studied by many authors. We consider the problem in the case that the unknown functions admit different degrees of smoothness. In this paper we propose a reducing component local polynomial method to estimate the unknown functions. It is shown that all of our estimators achieve the optimal convergence rates. The asymptotic distributions of our estimators are also derived. The established asymptotic results and the simulation results show that our estimators outperform the the existing two-step estimators when the coefficient functions admit different degrees of smoothness. We also develop methods to speed up the estimation of the model and the selection of the bandwidths.     

On the type-B integral equation and the distribution of wilks statist for testing independence of several groups of variables

In this paper, WILKS'type-B integral equation is solved in the general form of a series of beta functions and a series of weighted gamma functions as proposed by WALD and BROOKNER 1941. The coefficients in both representations can be obtained by explicit recurrence relartions, therefore the results solve many distributional problems and have the fewest computational difficulties of any representation that has surfaced to date. The radius of convergence of the second series representation is given, whereas the convergence property of the first series representation is given, whereas the convergence property of the first series representation was studied by WALD and Brookner. The exact null distributions of WILKS' statistic A for testing the independence of several groups of variables and of V = -log A are given. The coefficients in all the series representration can be computed recursilvely and hence can be obtained easily with the help of modern computatinal facilities     

Extension of the pool-adjacent-violators algorithm

The pool-adjacent-violators algorithm (PAVA) is an efficient algorithm which converges in a finite number of steps. However, it has been applicable so far only in isotonic regression with the simple order. This report extends its applicability to other quadratic programming problems, including certain one-sided multivariate testing problems and concave regression problems.     

IMPROVING POPULATION-SPECIFIC ALLELE FREQUENCY ESTIMATES BY ADAPTING SUPPLEMENTAL DATA: AN EMPIRICAL BAYES APPROACH

Estimation of the allele frequency at genetic markers is a key ingredient in biological and biomedical research, such as studies of human genetic variation or of the genetic etiology of heritable traits. As genetic data becomes increasingly available, investigators face a dilemma: when should data from other studies and population subgroups be pooled with the primary data? Pooling additional samples will generally reduce the variance of the frequency estimates; however, used inappropriately, pooled estimates can be severely biased due to population stratification. Because of this potential bias, most investigators avoid pooling, even for samples with the same ethnic background and residing on the same continent. Here, we propose an empirical Bayes approach for estimating allele frequencies of single nucleotide polymorphisms. This procedure adaptively incorporates genotypes from related samples, so that more similar samples have a greater influence on the estimates. In every example we have considered, our estimator achieves a mean squared error (MSE) that is smaller than either pooling or not, and sometimes substantially improves over both extremes. The bias introduced is small, as is shown by a simulation study that is carefully matched to a real data example. Our method is particularly useful when small groups of individuals are genotyped at a large number of markers, a situation we are likely to encounter in a genome-wide association study.     

服务台可修的多水平优先权排队(二)

文献[1]讨论了服务台可修的多水平优先权排队的排队指标。本文讨论该系统的可靠性指标。利用文献[3]中的随机序,获得了这些可靠性指标的界值。     

光纤转角、位移传感器的理论研究

提出了“光纤桥”新概念,利用“光纤桥”构成了测量转角、位移的光纤传感器。利用准高斯光束假设,详细地分析、计算了系统参数对传感器性能的影响,理论上预见了测角精度可达1”,测角范围±6′。     

组织信息资源管理论纲

本文在简要分析现代组织管理环境基本特点的基础上,对社会组织的信息资源管理的功能、原则及其运作等若干问题进行了认真的探讨,以期进一步完善现代组织管理理论。     

FIGARCH模型对股市收益长记忆性的实证分析

一、问题的提出长记忆性是指过去的冲击持续到将来,对预期的将来具有很大的影响。在大多数情况下,自相关函数的曲线图用来描述时间序列的长记忆特征。因此长记忆性可以定义如下：假设Ｙｔ是一个离散的时间序列,ｊ阶滞后的自相关函数为ρｊ,如果有ｌｉｍｎ→∞Σｎｊ＝...     

浅析水墨动画片的空间意识

水墨动画是中国传统水墨画与动画技术相结合的颇具民族特色的一种动画片种.它将中国传统水墨画的题材、笔墨节奏、审美空间意识引入到动画制作中,呈现"动画化"的水墨艺术.本文首先分析了传统水墨画所表现的节奏化自然、"阴阳"、"有无"的空间意识,再从属于电影范畴的水墨动画片的视听语言角度来阐述水墨艺术仅仅"动起来"还不够,还要达到真正意义上的"动画化",才能表现出比传统水墨画更有意蕴的空间意识.