Structural changes during a century of the world’s most popular sport

The analysis in this paper employs a methodology for dating structural breaks in tests with non-standard asymptotic distributions. The application examines whether changes in the rules of a game and major social and political events during the past century had significant effects upon various outcomes of this game. The statistical methodology first applied here proves successful as most breaks can be traced to specific events and rule changes. Dating these breaks allows us to obtain useful insights into production and competition processes in this industry. As such, using empirical tests we illustrate the utility of a valuable statistical technique not applied previously.Ignacio Palacios-Huerta: I am grateful to Gary S. Becker, Tony Lancaster, Robin Lumsdaine, Kevin M. Murphy, Gabriel Perez-Quiros, Ana I. Saracho, Amy Serrano, an associate editor and a referee for useful suggestions. I am also indebted to Barry Blake, Vicki Bogan, Salwa Hammami and Karen Wong for able research assistance, Tony Brown at the Association of Football Statisticians for the data the Hoover Institution for its hospitality, and the Spanish Ministerio de Ciencia y Tecnologia for financial support (grant BEC 2003-08182). The Gauss programs used in this paper were kindly provided by Bruce E. Hansen. Any errors are mine alone.     

基于灰色关联度和理想解法的决策方法研究

引入灰色系统理论对传统理想解法(TOPSIS)进行了拓展,提出了一种基于灰色关联度和理想解法(TOP-SIS)的决策方法。该方法将欧氏距离和灰色关联度有机结合,构造了一种新的相对贴近度以实现对方案的评价。新贴近度同时反映了方案与理想方案和负理想方案之间的位置关系和数据曲线的相似性差异,物理含义更加明确。最后通过一个供应商选择的示例进一步说明了方法的应用步骤。     

Imputation by power transformation

In this paper, a new power transformation estimator of population mean in the presence of non-response has been suggested. The estimator of mean obtained from proposed technique remains better than the estimators obtained from ratio or mean methods of imputation. The mean squared error of the resultant estimator is less than that of the estimator obtained on the basis of ratio method of imputation for the optinum choice of parameters. An estimator for estimating a parameter involved in the process of new method of imputation has been discussed. The MSE expressions for the proposed estimators have been derived analytically and compared empirically. Product method of imputation for negatively correlated variables has also been introduced. The work has been extended to the case of multi-auxiliary information to be used for imputation.     

关于中值定理“中间点”当x→+∞时的一个渐近估计式

讨论了在区间[a,x]上建立的中值定理“中间点”当x→＋∞时的渐近性态,给出了一个新的渐近估计式     

最小二乘圆弧法在圆图象分析中的应用

本文提出用圆方程作最小二乘法逼近,残量用径向差表达。当对圆图象进行分析时,可同时得出该图象的偏心度和径向误差,较好地解决了诸如评定圆度和机床主轴径跳的问题。     

微分方程在构造微分中值命题的辅助函数中的应用

众所周知,Lagrange定理、Cauchy定理[1]及其它许许多多微分中值命题的证明均借助于构造一个适当的辅助函数。然而,如何作辅助函数,如同作几何证明中的辅助线,需要较高的技巧,无一定法则可循,这给教学带来了难处。文[2]给出了一种辅助函数的“统一”构造法,只需按照一套固定的程序即可。本文利用简单微分方程的解构造出中值问题的辅助函数,从而得到寻求辅助函数的一种新方法。     

我院通信改造及设备选用

本文针对我院通信改造中存在的问题,提出了解决传输的办法及新设备的选用。     

Characterization of discrete populations through conditional expectations of order statistics

In this paper we give some properties of the expected values of any order statistic when one of its adjacent order statistics is known (order mean function) from a sequence of sizen of independent and identically distributed random variables with discrete distribution. Furthermore, we obtain the explicit expressions of the distribution from these order mean functions, and finally, we show the necessary and sufficient conditions for any real function to be an order mean function. We also add some examples of characterization of discrete distributions from the order mean functions. Partially supported by Consejería de Cultura y Educación (C.A.R.M.), under Grant PIB 95/90.     

Parametrically Guided Non-parametric Regression

We present a new approach to regression function estimation in which a non-parametric regression estimator is guided by a parametric pilot estimate with the aim of reducing the bias. New classes of parametrically guided kernel weighted local polynomial estimators are introduced and formulae for asymptotic expectation and variance, hence approximated mean squared error and mean integrated squared error, are derived. It is shown that the new classes of estimators have the very same large sample variance as the estimators in the standard non-parametric setting, while there is substantial room for reducing the bias if the chosen parametric pilot function belongs to a wide neighbourhood around the true regression line. Bias reduction is discussed in light of examples and simulations.     

Block diagrams and splitting criteria for classification trees

Various aspects of the classification tree methodology of Breiman et al., (1984) are discussed. A method of displaying classification trees, called block diagrams, is developed. Block diagrams give a clear presentation of the classification, and are useful both to point out features of the particular data set under consideration and also to highlight deficiencies in the classification method being used. Various splitting criteria are discussed; the usual Gini-Simpson criterion presents difficulties when there is a relatively large number of classes and improved splitting criteria are obtained. One particular improvement is the introduction of adaptive anti-end-cut factors that take advantage of highly asymmetrical splits where appropriate. They use the number and mix of classes in the current node of the tree to identify whether or not it is likely to be advantageous to create a very small offspring node. A number of data sets are used as examples.