How effective are the reset tests for omitted variables

In regression analysis, RESET has widely been regarded as an effective diagnostic test especially for omitted variables. This paper investigates the limitations of the existing RESET tests in detecting omitted variables. We analyze the sources from which RESET draws its power and point out the circumstances under which RESET will likely be ineffective. We offer some Monte Carlo evidence as well as an empirical application to illustrate the weaknesses of the RESET tests. A more robust RESET type test is proposed.     

A comparison of the mixture and classification approaches to cluster analysis

This paper examines the relative performance of two commonly used clustering methods based on maximum likelihood in the context of classifying a sample of observations of unknown origin arising from two normal populations with a common covariance matrix. the associated properties of the two methods are compared by conducting a series of simulation experiments under both mixture and separate sampling schemes.     

知识经济时代应重视学生的个性发展

知识经济的创新性本质，要求注重学生个性的充分发展。素质教育就是全面加速发展学生个性的活动。学生的个性发展离不开人际交往，师生关系是学生个性发展的纽带和桥梁。     

全站仪对边测量测站点位置的选择

根据全站仪对边测量原理，推导其精度公式，确定影响精度的主要因素，采用模拟数据分析对边测量精度状况以及与测站点位置的关系，指出有利的测站点位置，结论对现场测量工作有指导意义。     

论《大学》与大学的关系

<大学>是春秋战国时期曾子所写的一篇学习孔子思想的心得论文,作为中国高等教育机构的大学是中国近代后期的产物,但是长期以来有些学者却一直把<大学>视为论述大学教育的专著.事实上,不管是从历史的角度,还是从教育学的角度,<大学>和大学都没有必然的联系,两者的涵义也有本质的区别.<大学>在中国古代曾被作为教科书,但其本义是为了传授其中的儒学思想,并不是把它作为大学教育纲要来对待.     

求解铸件凝固问题的一种新方法

用线性摄动法给出了铸件在表面形状呈正弦变化的有限厚度铸型上凝固的三维热传导问题的数学模型，结合自变量变换法与有限差分法求解了热传导方程的数值解，给出了相变面随时间的变化过程和铸件的温度场分布情况．     

Confidence regions for parameters in linear models with additional information

Using given significant additional information it is possible to improve different confidence regions for the regression parameters in a linear model. Thereby, the given informations may concern the expectation and (or) the variance of the observations, and an improvement is possible in the sense of the decrease of the confidence regions' size. In particular it is possible to improve the so called confidence ellipsoids which are often used to estimate the considered parameters.     

The optimal Lp norm estimator in linear regression models

The least squares estimator is usually applied when estimating the parameters in linear regression models. As this estimator is sensitive to departures from normality in the residual distribution, several alternatives have been proposed. The L_p norm estimators is one class of such alternatives. It has been proposed that the kurtosis of the residual distribution be taken into account when a choice of estimator in the L_p norm class is made (i.e. the choice of p). In this paper, the asymtotic variance of the estimators is used as the criterion in the choice of p. It is shown that when this criterion is applied, other characteristics of the residual distribution than the kurtosis (namely moments of order p-2 and 2p-2) are important.     

On a superiority problem in misspecified restricted linear models

Razzaghi (1987) conjectures that a wrong choice of covariance matrix in a restricted linear model results in loss of efficiency, This conjecture is proved to be correct.     

A distance based regression model for prediction with mixed data

A multiple regression method based on distance analysis and metric scaling is proposed and studied. This method allow us to predict a continuous response variable from several explanatory variables, is compatible with the general linear model and is found to be useful when the predictor variables are both continuous and categorical. Real data examples are given to illustrate the results obtained.