统计学在20世纪的开拓性应用回顾

20世纪以来,作为数据搜集、整理和分析的一门重要工具,统计学在众多领域里得到了极其广泛的应用,统计学的作用及其重要性已渐渐显现出来。为了使统计学在20世纪所取得的进展及其重要性能为更多的人所认识和接受,并促进中国统计学的发展,对其在社会经济、自然科学以及生物医学等相关重要领域中的开拓性应用进行了简要的概述。这些应用一方面为统计学的发展提供了机遇,同时也向统计学提出了许多新的方法和应用上的挑战,为今后统计学的发展指明了方向。因而,对这些应用的回顾具有重要的实际意义。     

Selecting the optimum k in ridge regression

Two ridge rules are proposed for selecting the optimal k in ridge regression . Since the sampling distribution of the proposed rules are mathematically in tractable , a Monte Carlo study is conducted to examine their statisticl properties . Numerical results of the simulations in dicate that the performance of ridge rules depends upon the risk function used. Nevertheless, one of the ridge rules does produce a smaller mean squared error than the least squares estimator with the probability greater than 0.57 for all situations.     

Bounds on the biasing parameter in ridge regression

One of the problems with the ridge estimator is the appropriate value for the unknown biasing parameter k. In theory k can take a range of values, though some values are preferable to others. In this note we consider the optimum value for k and give bounds on the expected value of k.     

多维定位误差的CAEC建模与实验研究

为对三维机的多维定位误差提供CAEC信息,本文作者提出了“点阵综合计算法”,对多维定位误差的CAEC建模、实验进行了理论与实验方法的研究。     

A generalization and Bayesian interpretation of ridge-type estimators with good prior means

Pliskin (1987) and Trenkler (1988) compared ridge-type estimators with good prior means. From a Bayesian viewpoint, these estimators are special cases of Bayesestimators and the mean square error matrix comparisons can be made in the more general case.     

人口老龄化对制造业转型升级的影响

制造业转型升级是我国经济高质量发展的核心动力。为分析辽宁省人口老龄化对于制造业转型升级的影响,从劳动力禀赋效应、劳动生产率效应、资本积累效应、人力资本积累效应、消费需求效应五个方面分析人口老龄化对制造业转型升级的作用机理。在此基础上,利用辽宁省时间序列数据实证分析人口老龄化对制造业转型升级的影响。结果表明,人口老龄化对辽宁省制造业转型升级具有显著正向影响,外商直接投资、对外贸易、城镇化水平和研发强度对辽宁省制造业转型升级也发挥了重要作用。可从加强顶层设计、完善社会保障体系、提高劳动力素质等方面入手,进一步促进制造业转型升级。     

Multicollinearity and financial constraint in investment decisions: a Bayesian generalized ridge regression

This paper addresses the investment decisions considering the presence of financial constraints of 373 large Brazilian firms from 1997 to 2004, using panel data. A Bayesian econometric model was used considering ridge regression for multicollinearity problems among the variables in the model. Prior distributions are assumed for the parameters, classifying the model into random or fixed effects. We used a Bayesian approach to estimate the parameters, considering normal and Student t distributions for the error and assumed that the initial values for the lagged dependent variable are not fixed, but generated by a random process. The recursive predictive density criterion was used for model comparisons. Twenty models were tested and the results indicated that multicollinearity does influence the value of the estimated parameters. Controlling for capital intensity, financial constraints are found to be more important for capital-intensive firms, probably due to their lower profitability indexes, higher fixed costs and higher degree of property diversification.     

浅谈信息资源构建

概述IA定义、要求、核心、过程、现状、应用,点出IA不足,并且通过介绍与IA相关的情报学、知识管理、知识构建,进一步阐述IA内涵,同时对IA的发展前景和方向进行了展望。