输油管线的优化问题

本文针对榆油管的布置问题,运用图解法建立优化模型,并依据所给的数据,运用几何知识,计算出方案的具体解,对题目中的具体问题,建立优化模型,用lingo软件编写程序,从而得出铺设管线最省的方案.     

以信息素养培养为驱动的体育院校计算机教学模式探究

本课题在对西安体育学院和武汉体育学院学生调查问卷的回收数据进行计算机仿真处理的基础上,构建信息素养评价指标体系,并利用线性回归分析法计算得出每个指标的权重,为进一步分析学生的信息素养提供有力的实证。最后针对目前计算机教学中存在的问题,联系多年的教学实际分析和研究了以信息素养培养为驱动的体育院校计算机教学,提出基于评价体系的计算机教学新模式。     

中日物流合作创新模式探析

首先分析了中日物流合作的现状及问题,并通过构建回归模型对中日物流合作趋势进行分析及预测,最后提出了中日物流合作创新模式的建设性对策,以促进中日两国区域物流合作创新模式的构建。     

线性规划在金钼股份备货运输方面的应用

以金钼股份现实问题为例,利用线性规划相关知识和理论,以节约费用为目标,在分析各个影响变量的基础上,运用数学模型,求解出运输费用最低的前提下的产量和运输路线。     

A Review of the Use of Conditional Likelihood in Capture‐Recapture Experiments

We present a modern perspective of the conditional likelihood approach to the analysis of capture‐recapture experiments, which shows the conditional likelihood to be a member of generalized linear model (GLM). Hence, there is the potential to apply the full range of GLM methodologies. To put this method in context, we first review some approaches to capture‐recapture experiments with heterogeneous capture probabilities in closed populations, covering parametric and non‐parametric mixture models and the use of covariates. We then review in more detail the analysis of capture‐recapture experiments when the capture probabilities depend on a covariate.     

Statistical inference on seemingly unrelated non‐parametric regression models with serially correlated errors

This article is concerned with the inference on seemingly unrelated non‐parametric regression models with serially correlated errors. Based on an initial estimator of the mean functions, we first construct an efficient estimator of the autoregressive parameters of the errors. Then, by applying an undersmoothing technique, and taking both of the contemporaneous correlation among equations and serial correlation into account, we propose an efficient two‐stage local polynomial estimation for the unknown mean functions. It is shown that the resulting estimator has the same bias as those estimators which neglect the contemporaneous and/or serial correlation and smaller asymptotic variance. The asymptotic normality of the resulting estimator is also established. In addition, we develop a wild block bootstrap test for the goodness‐of‐fit of models. The finite sample performance of our procedures is investigated in a simulation study whose results come out very supportive, and a real data set is analysed to illustrate the usefulness of our procedures.     

Variance estimation in the change analysis of a linear regression model

We study a “direct test” of Chu and White (1992) proposed for detecting changes in the trend of a linear regression model. The power of this test strongly depends on a suitable estimation of the variance of the error variables involved. We discuss various types of variance estimators and derive their asymptotic properties under the null-hypothesis of “no change” as well as under the alternative of “a change in linear trend”. A small simulation study illustrates the estimators' finite sample behaviour.     

Variable Selection and Shrinkage: Comparison of Some Approaches

A common strategy within the framework of regression models is the selection of variables with possible predictive value, which are incorporated in the regression model. Two recently proposed methods, Breiman's Garotte (B reiman , 1995) and Tibshirani's Lasso (T ibshirani , 1996) try to combine variable selection and shrinkage. We compare these with pure variable selection and shrinkage procedures. We consider the backward elimination procedure as a typical variable selection procedure and as an example of a shrinkage procedure an approach of V an H ouwelingen and L e C essie (1990). Additionally an extension of van Houwelingens and le Cessies approach proposed by S auerbrei (1999) is considered. The ordinary least squares method is used as a reference.
With the help of a simulation study we compare these approaches with respect to the distribution of the complexity of the selected model, the distribution of the shrinkage factors, selection bias, the bias and variance of the effect estimates and the average prediction error.     

The gender pay gap in the transition from communism: some empirical evidence

This short paper investigates the gender pay gap in a number of former communist countries of eastern Europe and the Soviet Union. The main findings are that, in general, the gender pay gap has not exhibited an upward tendency over the transitional period to which available data relate. Most of the gender pay gap is ascribed to the ‘unexplained’ component using conventional decompositions and this may partly be attributable to the proxy measure for labour force experience used in this study. Quantile regression analysis indicates that in all but one country, the ceteris paribus gender pay gap rises as we move up the wage distribution.