Performance of the difference-based Liu-type estimator in partially linear model

This paper discusses the parameter estimation in a partially linear model. We proposed a difference-based Liu-type estimator of the unknown parameters in the partially linear model. The asymptotically properties of the proposed estimator are discussed. We propose a iterative method to choose the biasing parameters. Finally, a simulation study and a numerical example are presented to explain the performance of the estimators.     

基于协方差阵特征结构的新型控制图研究

本文在深入分析现行广义方差类的统计控制图存在的统计监控缺陷的基础上,提出了对多变量过程的协方差阵的特征向量张成的坐标系的一致性进行统计监控的C控制图,以及对特征值构成的椭球体的相似性进行监控的S控制图,有效地提高了对多变量过程的协方差阵的异常变动的统计监控能力。仿真表明,联合使用C控制图、S控制图及常规均值T²控制图,能够实现对多变量过程的协方差阵与均值的系统监控,显著改善监控效率。     

A new stochastic mixed Liu estimator in linear regression model

Abstract

To overcome multicollinearity, a new stochastic mixed Liu estimator is presented and its efficiency is considered. We also compare the proposed estimators in the sense of matrix mean squared error criteria. Finally a numerical example and a simulation study are given to show the performance of the estimators.     

Statistical Estimates for Modified Gravitation Model by Aggregated Data

A nonlinear regression model for forecasting of passenger flow between various spatial points (towns) is described. Unknown parameters are estimated using aggregated data when the information about a number of the departed passengers from each town is available only. For estimation, the least squares and maximum likelihood methods are used. Numerical examples are performed to illustrate the proposed approaches.     

Creating catalogues of two-level nonregular fractional factorial designs based on the criteria of generalized aberration

We consider the problem of constructing good two-level nonregular fractional factorial designs. The criteria of minimum G and G₂ aberration are used to rank designs. A general design structure is utilized to provide a solution to this practical, yet challenging, problem. With the help of this design structure, we develop an efficient algorithm for obtaining a collection of good designs based on the aforementioned two criteria. Finally, we present some results for designs of 32 and 40 runs obtained from applying this algorithmic approach.     

Efficient estimation for incomplete multivariate data

We review the Fisher scoring and EM algorithms for incomplete multivariate data from an estimating function point of view, and examine the corresponding quasi-score functions under second-moment assumptions. A bias-corrected REML-type estimator for the covariance matrix is derived, and the Fisher, Godambe and empirical sandwich information matrices are compared. We make a numerical investigation of the two algorithms, and compare with a hybrid algorithm, where Fisher scoring is used for the mean vector and the EM algorithm for the covariance matrix.     

基于卫星云图的视场坐标转化模型

利用卫星云图的灰度矩阵,可以换算出经纬度等信息,并由此对不同时刻的卫星数据进行有效的风矢度量。本文运用地心坐标系统,构建了几何模型,结合lagrange插值法给出了灰度矩阵元素行列号对应于经纬度坐标的换算公式;借助Matlab软件得出了灰度矩阵中对应行、列的经纬二维数组;并用Matlab将灰度矩阵转化为卫星云图,并添加经纬信息,统一坐标系统后用Matlab绘制海岸线。     

宝鸡钛产业发展的思考

宝鸡走向全国,面向世界的优势和城市名片就是“中国钛城”。根据SWOT态势分析,宝鸡要建设具有国际竞争力的“中国钛城”,就应当提高宝鸡市钛材加工能力,增强钛材的竞争力。进行钛加工资源的重组、整合,全力推进骨干企业集团化、规模化,实现聚集效应。加大科技投入力度,努力形成适合我国国情的钛合金材料体系,真正使钛产业成为宝鸡最具竞争优势的产业。     

三端点区间数互反判断矩阵的排序方法研究

本文研究了三端点区间数互反判断矩阵的一致性和排序方法。在三端点区间数互反判断矩阵完全一致性概念的基础上,首次将矩阵特征向量思想引入三端点区间数互反判断矩阵之中——研究了三端点区间数互反判断矩阵的一致性与权重向量之间的类似特征向量关系,并运用线性规划模型给出一种处理三端点区间数决策者对方案属性权重的方法,然后通过三端点区间数权重向量的期望值,进行方案集结排序。最后通过具体的案例,验证了所提出方法的有效性和适用性。     

Trajectories of Fertility and Household Composition in the Demographic Profile of the Czech Republic

The household composition matrix is a representation of the demographic structure of households, specific to age groups of household members and household heads. As such, the matrix reflects also the environmental conditions, housing in particular, that mould households' demographic structure. By specifically depicting the presence of children in households, household composition could be viewed as gauging fertility within the context of housing conditions. This stance is examined in an application to Czech census data for the year 1991, at the commencement of an intense process of socio-economic transformation that accompanied the collapse of communism across Eastern Europe. Within this process, housing had an inadvertent impact upon the structure of households in general, and upon fertility decline in particular. By using the standard matrix representation of household composition, correspondence between trajectories of age-specific fertility and household composition emerge throughout the Czech Republic. This correspondence illustrates the potential household composition analysis carries for fertility measurement and estimation in rapidly changing economic environments.