数学美在科学探索中的功能

本文通过对数学和自然科学发展史的考察,认为数学美在科学家的科学实践活动中,发挥着重要的动力作用和方法论功能。即数学美为科学探索提供持久的内在动力;为科学发现提供武器和导引;为科学成果提供选择和评价的标准。     

中国企业呼唤敏捷制造战略

本文简述了敏捷制造战略的主要思想,指出在中国实施敏捷制造战略是当务之急。为此,需要从中国制造业的实际出发解决敏捷化的制造单元技术,以敏捷方式集成制造单元等关键问题。本文认为中国的敏捷化制造单元的构建可基于独立制造岛,提出了以虚拟企业方式实施中国的集团化经营战略的设想。     

区域主导产业评价指标与数学模型

以现有研究成果为基础,建立了区域主导产业评价指标体系;基于灰色聚类的思想,提出了评价区域主导产业优度的数学模型-定权聚类评估模型,并对河南省武陟县工业主导产业选择进行了实证研究。     

规划调整决策任务分解、认知限制与决策支持

规划调整决策问题(PCDPs-Program and Control Decision Problems)都比较宏观综合,涉及面广且结构性差,决策支持需求不易确定。本论文将通过决策任务分解说明决策认知过程,并在知识分类的基础上论述完成决策任务中的认知限制,进而从扩展决策者的认知能力出发给出了决策支持基本功能设计和开发规划调整决策支持系统(PCDSS)的三层结构。     

Multilevel models for repeated binary outcomes: attitudes and voting over the electoral cycle

Models for fitting longitudinal binary responses are explored by using a panel study of voting intentions. A standard multilevel repeated measures logistic model is shown to be inadequate owing to a substantial proportion of respondents who maintain a constant response over time. A multivariate binary response model is shown to be a better fit to the data.     

Multivariate bandwidth selection for local linear regression

The existence and properties of optimal bandwidths for multivariate local linear regression are established, using either a scalar bandwidth for all regressors or a diagonal bandwidth vector that has a different bandwidth for each regressor. Both involve functionals of the derivatives of the unknown multivariate regression function. Estimating these functionals is difficult primarily because they contain multivariate derivatives. In this paper, an estimator of the multivariate second derivative is obtained via local cubic regression with most cross-terms left out. This estimator has the optimal rate of convergence but is simpler and uses much less computing time than the full local estimator. Using this as a pilot estimator, we obtain plug-in formulae for the optimal bandwidth, both scalar and diagonal, for multivariate local linear regression. As a simpler alternative, we also provide rule-of-thumb bandwidth selectors. All these bandwidths have satisfactory performance in our simulation study.     

基于T-S模糊模型的非线性组合预测方法研究

一、引言自从Ｊ．Ｍ．Ｂａｔｅｓ和Ｃ．Ｗ．Ｊ．Ｇｒａｎｇｅｒ首次提出组合预测方法［１］以来,组合预测的研究已经取得很大的进展,文献［２～６］对此有比较详细的综述和评价。根据集结或组合各单项预测模型的方式不同,组合预测一般可分为线性组合预测和非线性组合预...     

Multiple roots of estimating functions

Estimating functions can have multiple roots. In such cases, the statistician must choose among the roots to estimate the parameter. Standard asymptotic theory shows that in a wide variety of cases, there exists a unique consistent root, and that this root will lie asymptotically close to other consistent (possibly inefficient) estimators for the parameter. For this reason, attention has largely focused on the problem of selecting this root and determining its approximate asymptotic distribution. In this paper, however, we concentrate on the exact distribution of the roots as a random set. In particular, we propose the use of higher-order root intensity functions as a tool for examining the properties of the roots and determining their most problematic features. The use of root intensity functions of first and second order is illustrated by application to the score function for the Cauchy location model.     

高等教育可持续发展的几个问题

可持续发展战略包括社会的全面进步和可持续发展, 教育是实现可持续发展的关键,同时其本身也必须得到可持续发展。本文引入教育生态学的观点,关注高等教育的可持续发展问题,认为教育的生态平衡是高教可持续发展的最关键思想     

我国统筹城乡养老保险制度研究评述

在城乡二元经济结构导致城乡经济发展不平衡的大背景下,政府对城乡社会养老保险制度的不同设计以及对养老投入的不同水平,造成我国目前城乡实际养老保障水平之间存在很大差异。伴随我国农村人口日趋老龄化、土地保障功能弱化以及计划生育下养儿防老观念的逐步淡化,我国农村养老问题日益凸显,构建城乡一体的养老保险制度、统筹城乡养老保险体系问题引起了社会和学者的广泛关注。文章对近年来国内学界对统筹城乡养老保险的相关研究进行了归纳,就我国统筹城乡养老保险制度的必要性、可行性、路径步骤等,进行了总结和评价,以期对政府统筹城乡养老的有关政策提供理论参考。