有初始缺陷粘弹性压杆的蠕变屈曲

研究有初始缺陷粘弹性压杆的蠕变屈曲,讨论分析了瞬时临界载荷和长期临界载荷对粘弹性压杆蠕变屈曲的影响。     

Churning races in Canada: Visible minority response change between 2006 and 2011

Why do most people have stable responses to census race questions, while some do not? Using linked Canadian data, we examine personal, social, and economic characteristics that predict response stability as White or as one of six large visible minority groups, versus a change in response to/from White or to/from another visible minority group. Response change rates in Canada are generally comparable to those in the US, UK, and New Zealand. Likely reflecting the centuries-old hegemony of Whites in these countries, White is the most stable response group in Canada as well as the US, UK, and New Zealand. Multiple-race response groups are among the newest and least stable response groups. Social statuses and experiences (mixed ethnic heritage, immigration status, and exposure to own-group members) are generally more predictive of race response stability and change than economic (income level and change in income) or personal statuses (education, age). This highlights the socially-constructed nature of race group boundaries. Joining and leaving a group are often predicted by the same status/characteristic and in the same direction, hinting that the status/characteristic adds complexity to the race-related experiences of constituents.     

Logistic与分类树模型变量筛选的比较——基于信用卡邮寄业务响应率分析

基于信用卡邮寄业务响应率分析来讨论Logistic模型和分类树模型在变量选取上的区别,并尝试从几个不同角度去解释两类模型变量筛选差异的原因。笔者认为没有绝对占优势的方法,需要结合具体场景和模型的特点来选择合适的模型。分类树模型在训练集上容易过度拟合,对单个变量的影响很敏感,在进行危险因素分析时结果更能强调危险因素,对孤立点的识别率很高。Logistic模型容易受到解释变量依存关系的影响,加上分类变量的影响容易过多地选入变量或者因子,对孤立点敏感,对噪点不敏感。判别函数的差异是变量筛选差异的关键因素。     

Optimal designs for response functions with a downturn

In many toxicological assays, interactions between primary and secondary effects may cause a downturn in mean responses at high doses. In this situation, the typical monotonicity assumption is invalid and may be quite misleading. Prior literature addresses the analysis of response functions with a downturn, but so far as we know, this paper initiates the study of experimental design for this situation. A growth model is combined with a death model to allow for the downturn in mean doses. Several different objective functions are studied. When the number of treatments equals the number of parameters, Fisher information is found to be independent of the model of the treatment means and on the magnitudes of the treatments. In general, A- and D_A-optimal weights for estimating adjacent mean differences are found analytically for a simple model and numerically for a biologically motivated model. Results on c-optimality are also obtained for estimating the peak dose and the EC₅₀ (the treatment with response half way between the control and the peak response on the increasing portion of the response function). Finally, when interest lies only in the increasing portion of the response function, we propose composite D-optimal designs.     

机载SAR斜侧视成像的高效空变算法

针对机载合成孔径雷达ＳＡＲ斜侧视成像的二维处理特性，采用一种全聚焦的处理方法，它能方便地处理斜侧视ＳＡＲ参考函数的空间变化的特性，并提高计算效率。     

Electricity consumption prediction with functional linear regression using spline estimators

A functional linear regression model linking observations of a functional response variable with measurements of an explanatory functional variable is considered. This model serves to analyse a real data set describing electricity consumption in Sardinia. The interest lies in predicting either oncoming weekends’ or oncoming weekdays’ consumption, provided actual weekdays’ consumption is known. A B-spline estimator of the functional parameter is used. Selected computational issues are addressed as well.     

Testing for order among K populations: theory and examples

Testing for stochastic order among K populations is a common and important problem in statistical practice. It arises in the analysis of both planned experiments and observational studies. The authors develop a new nonparametric test for order among K populations that can accommodate any stochastic ordering. The test is based on a maximally selected chi‐bar‐square statistic. The authors find its limiting distribution and use simulations to derive critical values. Three important examples are used to illustrate the applicability of the general method. The authors find that the new tests outperform the existing methods in many practical cases. The Canadian Journal of Statistics 38: 97–115; 2010 © 2009 Statistical Society of Canada     

Low dose risk estimation via simultaneous statistical inferences

Summary.  The paper develops and studies simultaneous confidence bounds that are useful for making low dose inferences in quantitative risk analysis. Application is intended for risk assessment studies where human, animal or ecological data are used to set safe low dose levels of a toxic agent, but where study information is limited to high dose levels of the agent. Methods are derived for estimating simultaneous, one-sided, upper confidence limits on risk for end points measured on a continuous scale. From the simultaneous confidence bounds, lower confidence limits on the dose that is associated with a particular risk (often referred to as a bench-mark dose ) are calculated. An important feature of the simultaneous construction is that any inferences that are based on inverting the simultaneous confidence bounds apply automatically to inverse bounds on the bench-mark dose.     

中国货币政策和财政政策相对有效性的实证研究

在我国由计划经济向市场经济的体制转轨过程中,货币政策和财政政策已成为我国宏观经济调节的主要手段,在我国的经济发展中发挥了重要作用。但货币政策和财政政策是各自独立的政策体系,由于作用的方式和条件有较大区别,其效果也有较大不同,文章试图应用脉冲响应函数和方差分解方法,对改革开放以来我国货币政策和财政政策的效果进行实证比较研究,并得出有关结论,为我国的宏观调控政策提供理论分析和实证检验的依据。     

过程写作法在英语专业低年级的运用

过程写作法近年来盛行海外，已经成为西方写作教学主流。它将写作视为交互循环的心理认知过程和语言交际过程，重视写作的具体过程及其交际性，被证明对于提高学习者写作能力效果显著。本文系统地研究了过程写作法产生的背景、理论基础及其在写作教学中的实际应用。