聚合物基纳米复合材料

聚合物基纳米复合材料以其独特的性能受到人们的重视。主要介绍聚合物基纳米复合材料的制备方法、性能、应用及国内外研究现状。     

自动云纹干涉系统及其在复合材料中的应用

本文介绍了一种自动云纹干涉系统，包括其基本原理、软硬件设备、特别是干涉条纹的自动采集与处理方法，以及在复合材料的层缩区应力分析、叠层面应力分析和Ｉｏｓｉｐｅｓｃｕ试件应力分析中的应用。     

光学分辨率判据和可见度

本文研究了两个非相干点光源靠近时，在圆孔的夫琅和费衍射下两个光斑之间可见度的变化情况。对于不同判据，可见度有明显差异，表现出各种判据的不一致性。同时还研究了光栅的夫琅和费衍射，当两明条纹很靠近时，可见度的变化情况。同样可以得到各判据相应的数值。     

用量纲分析法估算挤压机的生产率和功率

在塑料、橡胶、食品加工等领域挤压机有着广泛的应用.挤压机的功率和生产率是设计、制造和使用挤压机时需要了解的重要参数之一.然而,传统的计算方法较复杂,本文用相似理论推出了挤压机的生产率和功率的计算公式.简单、实用.     

长江上游特旱特涝年夏季风特征的分析

本文采用700百帕、500百帕上的假相当位温θse和温度露点差(t—td)的候平均演变曲线,反映出长江上游地区夏季风的变化,并对比分析了长江上游特旱的1972年和特涝的1974年的夏季风活动规律,表明干旱年受夏季风影响的时间短于洪涝年。通过500百帕上的候平均θse值,构造了一个表征当年夏季风特征的夏季风的综合指数Icsm,分析结果表明,该指数能反映出夏季风到达迟早、持续时间及强度等特征,为长江上游的旱涝预报提供了一个依据。     

Robust designs for first-order multiple design multivariate models

This paper deals with the methodology of obtaining designs that are robust to nonnormality of the error distribution for tests associated with first-order multiple design multivariate linear models.A sequential procedure is given for the generation of the proposed designs.     

INDEX TO VOLUME 17 (1999)

We study how to select or combine estimators of the average treatment effect (ATE) and the average treatment effect on the treated (ATT) in the presence of multiple sets of covariates. We consider two cases: (1) all sets of covariates satisfy the unconfoundedness assumption and (2) some sets of covariates violate the unconfoundedness assumption locally. For both cases, we propose a data-driven covariate selection criterion (CSC) to minimize the asymptotic mean squared errors (AMSEs). Based on our CSC, we propose new average estimators of ATE and ATT, which include the selected estimators based on a single set of covariates as a special case. We derive the asymptotic distributions of our new estimators and propose how to construct valid confidence intervals. Our Monte Carlo simulations show that in finite samples, our new average estimators achieve substantial efficiency gains over the estimators based on a single set of covariates. We apply our new estimators to study the impact of inherited control on firm performance.     

Corrigendum for: The Distribution of Family Sizes Under a Time-Homogeneous Birth and Death Process

Regretably, there are a number of significant errors in Moschopoulos and Shpak, (2010). Communications in Statistics—Theory and Methods 39:1761–1775. Most are typographic errors that have the potential to cause confusion, and in some instances, have carried through to several equations.     

Monotony relations between distribution functions and their application to experimental design

In a linear regression model an estimator of the unknown coefficients is considered which, in special cases, includes the least squares estimator. In the ease of stable symmetric error distribution and by means of a certain monotony relation between distribution functions optimality of this estimator is proved and the designing problem is investigated. A robustness property of optimal designs against the designing criterion and some conclusions are given concerning the least squares estimator in the case of G- and C-optimality.     

On the relationship between levinson recursion and the r and s arrays for arma model identification

Motivated by the papers of Woodward and Gray (1979) and Gray, Kelly and McIntire (1978) on the R and S array approach to ARMA modeling, the authors show that the R and S array algorithm is completely equivalent to Levinson recursion. Since entries in the R and S array can be computed by either algorithm, the equivalence provides greater insight into the R and S methodology as well as its links to Akaike's AIC or FPE. Numerical simulations serve to highlight the differences between the various approaches as well as illustrate the problems associated with exact methods. The K and S array approach is shown to be an effective procedure for determining ARMA model orders.