民法与经济法的经济学基础

民法是市场经济的基本法,是市场调节机制发挥作用的法律保障。经济法的概念及调整对象虽然学术界尚未形成定论,但大都定位在弥补市场缺陷,规范国家干预之上。如果说,成熟的经济学与幼稚的法学的提法过于偏颇,在市场与国家关系领域,经济学的确比法学成熟得多。运用经济学理论,对民法与经济法进行法律的经济分析,不失为科学界定二者调整范围的佳径。     

论高等教育中政府调节的职能定位与调节失灵现象

政府调节是高等教育调节机制的重要组成部分.在高等教育运行中,加强政府宏观管理职能,防止职能的缺位、越位、错位是高等教育管理体制改革的核心问题.为了有效地提供高等教育公共产品,解决高等教育外部性问题,克服高等教育资本市场的缺陷,政府确实有必要加强对高等教育的干预和调节.政府的高等教育调节职能主要有三个,即资源配置职能、实现社会公平职能、稳定职能.高等教育中的政府失灵主要表现为高等教育政治决策失误、高等教育管理的过度集中、高等教育管理机构的低效率、高等教育物品分配的不平等.为了矫正高等教育中的政府失灵,有必要准确界定政府的作用范围、选择合理的干预手段、厘定干预的限度.     

Local model uncertainty and incomplete-data bias (with discussion)

Summary.  Problems of the analysis of data with incomplete observations are all too familiar in statistics. They are doubly difficult if we are also uncertain about the choice of model. We propose a general formulation for the discussion of such problems and develop approximations to the resulting bias of maximum likelihood estimates on the assumption that model departures are small. Loss of efficiency in parameter estimation due to incompleteness in the data has a dual interpretation: the increase in variance when an assumed model is correct; the bias in estimation when the model is incorrect. Examples include non-ignorable missing data, hidden confounders in observational studies and publication bias in meta-analysis. Doubling variances before calculating confidence intervals or test statistics is suggested as a crude way of addressing the possibility of undetectably small departures from the model. The problem of assessing the risk of lung cancer from passive smoking is used as a motivating example.     

Reproducibility of clinical data I: continuous outcomes

Across a variety of clinical settings, repeated measurements on an individual, obtained under identical circumstances, often differ from one another. This implies the measurements lack perfect reproducibility. Topics related to reproducibility of clinical measurements are introduced in this paper. In this first of two parts, continuous outcomes are addressed. The intraclass correlation coefficient, ρ, has been the traditional coefficient of reproducibility for continuous outcomes. The importance of ρ regarding observations on an individual, and observations among populations, is outlined. Estimation and inferential procedures for ρ are reviewed and worked examples are provided. Copyright © 2004 John Wiley & Sons, Ltd.     

归因理论在数学教学中的指导意义

该文首先介绍了社会心理学中的归因理论,并结合作者的实际工作,论述了归因理论对数学教学工作的指导意义。它包括:教师必须弄清学生学习失败的真正原因,帮助学生树立自信心,并不断使其体验到因具备能力并加上自身的努力后取得成功的喜悦;强调经过努力获得成功也是学生自身能力的体现。教师应努力使学生深信,他们所要完成的学习任务是很有价值的,能够通过自我控制达到最佳的效果。     

Accounting for Both Random Errors and Systematic Errors in Uncertainty Propagation Analysis of Computer Models Involving Experimental Measurements with Monte Carlo Methods

A Monte Carlo method is presented to study the effect of systematic and random errors on computer models mainly dealing with experimental data. It is a common assumption in this type of models (linear and nonlinear regression, and nonregression computer models) involving experimental measurements that the error sources are mainly random and independent with no constant background errors (systematic errors). However, from comparisons of different experimental data sources evidence is often found of significant bias or calibration errors. The uncertainty analysis approach presented in this work is based on the analysis of cumulative probability distributions for output variables of the models involved taking into account the effect of both types of errors. The probability distributions are obtained by performing Monte Carlo simulation coupled with appropriate definitions for the random and systematic errors. The main objectives are to detect the error source with stochastic dominance on the uncertainty propagation and the combined effect on output variables of the models. The results from the case studies analyzed show that the approach is able to distinguish which error type has a more significant effect on the performance of the model. Also, it was found that systematic or calibration errors, if present, cannot be neglected in uncertainty analysis of models dependent on experimental measurements such as chemical and physical properties. The approach can be used to facilitate decision making in fields related to safety factors selection, modeling, experimental data measurement, and experimental design.     

Semiparametric Global Cross-ratio Models for Bivariate Censored Data

Abstract.  Multivariate correlated failure time data arise in many medical and scientific settings. In the analysis of such data, it is important to use models where the parameters have simple interpretations. In this paper, we formulate a model for bivariate survival data based on the Plackett distribution. The model is an alternative to the Gamma frailty model proposed by Clayton and Oakes. The parameter in this distribution has a very appealing odds ratio interpretation for dependence between the two failure times; in addition, it allows for negative dependence. We develop novel semiparametric estimation and inference procedures for the model. The asymptotic results of the estimator are developed. The performance of the proposed techniques in finite samples is examined using simulation studies; in addition, the proposed methods are applied to data from an observational study in cancer.     

Extreme value models with application to drought data

Summary The exact distributions of the productXY are derived whenX andY are independent random variables and come from the extreme value distribution of Type I, the extreme value distribution of Type II or the extreme value distribution of Type III. Of the, six possible combinations, only three yield closed-form expressions for the distribution ofXY. A detailed application of the results is provided to drought data from Nebraska. The author would like to thank the referees and the Associate Editor for carefully reading the paper and for their great help in improving the paper.     

What makes motherhood so expensive?: The role of social expectations, interdependence, and coordination failure in explaining lower wages of mothers

This paper utilizes expectations imposed by society to explain lower wages of mothers compared to non-mothers in the labor market. Social expectation, interdependence between mothers’ labor supply and childcare services, and lack of coordination between employers, employees (mothers), and childcare services explain how an economy can be caught in a ‘trap’ exhibiting large wage differences. Higher levels of human capital, increased coordination along with affordable childcare services in a more modern economy allows for specialization, increasing returns, and the possibility for a better outcome due to multiple equilibria.     

铝合金材料LY12CZ临界空穴扩张比的适用性探讨

对光滑试样和 3种不同曲率半径的切口试样 ,采用拉伸试验和电镜观测相结合的方法 ,研究了铝合金材料LY12CZ的VGC 参数的适用性。证实VGC 参数对材料的断裂形式较为敏感 ,适用于以拉伸型断裂为主的切口试样 ,对以剪切断裂为主的光滑拉伸试样不适用。