An alternative to model selection in ordinary regression

The weaknesses of established model selection procedures based on hypothesis testing and similar criteria are discussed and an alternative based on synthetic (composite) estimation is proposed. It is developed for the problem of prediction in ordinary regression and its properties are explored by simulations for the simple regression. Extensions to a general setting are described and an example with multiple regression is analysed. Arguments are presented against using a selected model for any inferences.     

文化需求与信息资源管理的转型

由于人文环境的巨大转变及互联网文化无可匹敌的影响,21世纪的都市文化需求尤其是阅读需求,发生了革命性的变化.都市文化与人本角色的这种互动,对于社会科学信息资源的合理配置和深度开发利用,具有决定性的影响,并直接造成了信息资源管理模式的转型.重点讨论都市文化需求对信息资源合理配置的影响,以及由此产生的信息资源管理模式的转范.     

Goodness‐of‐fit methods for matched case‐control studies

The authors propose graphical and numerical methods for checking the adequacy of the logistic regression model for matched case‐control data. Their approach is based on the cumulative sum of residuals over the covariate or linear predictor. Under the assumed model, the cumulative residual process converges weakly to a centered Gaussian limit whose distribution can be approximated via computer simulation. The observed cumulative residual pattern can then be compared both visually and analytically to a certain number of simulated realizations of the approximate limiting process under the null hypothesis. The proposed techniques allow one to check the functional form of each covariate, the logistic link function as well as the overall model adequacy. The authors assess the performance of the proposed methods through simulation studies and illustrate them using data from a cardiovascular study.     

关于移动自组网自安全证书管理模型

对目前建立移动自组网信任模型的各种主流方案进行了分类和评述,重点阐述了自安全证书管理模型各种方案的优缺点,并指出了今后的研究方向.     

探析我国金融控股公司的建立模式与监管制度

金融服务业的变革和一体化,促进了金融集团及金融控股公司的发展。我国金融控股公司有两种模式:非金融企业控股公司和银行控股公司。在监管制度上,强调应实行综合监管与分业监管相结合,从传统监管方式向风险目标值法转移,要制定对金融控股公司资本充足性的监管,建立内部的“防火墙”。     

力学实验教学改革的探索与实践

力学实验作为力学课程中重要的实践性教学环节,对于培养工科学生用科学的方法来研究处理实际问题的能力和创新精神,提高学生的综合素质有着极其重要的作用.文章分析了力学实验教学改革的实践,探讨了提高力学实验教学效果的改革思路;提出要通过开发综合性与研究性实验项目,探索合理的实验教学模式,加强培养学生解决工程实际问题的能力及力学建模能力.     

康德先验逻辑的基本问题

康德的先验逻辑对传统哲学特别是形而上学所运用的范畴在分类的基础上作了新的理解,指出了范畴作为思维的逻辑功能,是对感性直观的固有关系。这就决定了先验逻辑的基本问题是范畴与直观的固有关系问题。它构成先验逻辑不同于形式逻辑和思辨逻辑的根本点。     

马哲视角的人存在方式探研

人以社会实践活动方式而存在,从中形成人与自然、人与人、人与社会、人与人自身诸矛盾及人的生产与消费的矛盾,这后一矛盾是人存在方式中的根本矛盾。近代工业文明以来,由于人对自我存在方式的科学性、社会性、预见性和终极价值维度不能给予唯物辩证把握,而陷入存在方式的误区。直面生存危机,以马克思主义哲学为指导,探索建施人全面持续发展为宗旨的存在方式是时代课题。     

劳动力密集地区非均衡流动——对河南省固始县劳动力流动及县域经济发展的调查

在劳动力密集的河南省,大量输出劳动力可以迅速促进当地经济的发展和人民生活水平的提高,但人们往往忽视从长远看过量输出导致的非均衡流动却可能束缚输出地经济的发展,笔者通过对河南省信阳市固始县为期13天的调研,对这一问题进行了研究。本文描述了劳动力的大量输出对当地经济发展的促进,着重分析了当地劳动力流动的原因,并分析了非均衡流动给当地经济未来发展带来的三个问题。文章将在前半部分从劳动力流动的环境动力和劳动力流动去向的角度,结合劳动力流动的相关理论,对谷围村劳动力流动情况进行分析,并用"吸出模型"解释劳动力非均衡流动带来的问题和产生的原因。文章后半部分从劳动力大量输出对当地县域经济影响的角度分析了在劳动力密集的固始县企业招工难且劳动力成本高于外地的奇怪现象。最后,文章对固始县为实现劳动力均衡流动而采取的措施进行了研究,总结出劳动力过量输出地区的经济发展模式即"固始模式",并对该模式进行了分析。     

A partial score test for difference among heterogeneous populations

In event time data analysis, comparisons between distributions are made by the logrank test. When the data appear to contain crossing hazards phenomena, nonparametric weighted logrank statistics are usually suggested to accommodate different-weighted functions to increase the power. However, the gain in power by imposing different weights has its limits since differences before and after the crossing point may balance each other out. In contrast to the weighted logrank tests, we propose a score-type statistic based on the semiparametric-, heteroscedastic-hazards regression model of Hsieh [2001. On heteroscedastic hazards regression models: theory and application. J. Roy. Statist. Soc. Ser. B 63, 63–79.], by which the nonproportionality is explicitly modeled. Our score test is based on estimating functions derived from partial likelihood under the heteroscedastic model considered herein. Simulation results show the benefit of modeling the heteroscedasticity and power of the proposed test to two classes of weighted logrank tests (including Fleming–Harrington's test and Moreau's locally most powerful test), a Renyi-type test, and the Breslow's test for acceleration. We also demonstrate the application of this test by analyzing actual data in clinical trials.