基于数学思维学习英语时态的策略

英语中的时态是一个重要的语法范畴,是英语学习中的重点和难点,十六种时态的用法对于许多英语学习者来说都是一个难题。本文通过数轴、公式推导等数学知识,拟介绍一种借助数学思维学习英语时态的方法,帮助学生直观形象地理解不同时态的含义与用法。     

Resolving a Multi-Million Dollar Contract Dispute With a Latin Square

The City of New York negotiated a dispute over the performance of new garbage trucks purchased from a vehicle manufacturer. The dispute concerned the fulfillment of a specification in the purchase contract that the trucks load a minimum full-load of 12.5 tons of household refuse. On behalf of the City, but in cooperation with the manufacturer, the City's Department of Sanitation and consulting statisticians tested fulfillment of the contract specification, employing a Latin Square design for routing trucks. We present the classical analysis using a linear model and analysis of variance. We also show how fixed, mixed, and random effect models are useful in analyzing the results of the test. Finally, we take a Bayesian perspective to demonstrate how the information from the data overcomes the difference between the prior densities of the city and the manufacturer for the load capacities of the trucks to result in much closer posterior densities. This procedure might prove useful in similar negotiations. Supplementary material including the data and R code for computations in the article are available online.     

Reinterpreting the relation between motherhood and paid work: second‐generation immigrant women in Norway

A pertinent question in contemporary Europe is whether the children of immigrants will reproduce the gender‐complementary practices and ideals of the immigrant generation, which often include strong expectations that women should prioritize family obligations over the pursuit of paid work. This article analyses the cultural and moral understandings at stake in second‐generation women's reflections on and practices of combining motherhood and paid work, and explores the space for negotiating such understandings in the family. The study is based on in‐depth interviews with second‐generation women of Pakistani descent in Norway, and interviews with some of their husbands. The findings show that the moral understandings and practices of the parent generation are not merely passed on to the second generation; rather they are challenged and reinterpreted in ways that support mothers' participation in paid work. The article argues that this change is facilitated by the cultural and institutional context that the Norwegian welfare state represents.     

Confidence interval estimation for number of patient‐years needed to treat

The number of patient‐years needed to treat (N_PYNT), also called the event‐based number needed to treat, to avoid one additional exacerbation has been reported in recently published respiratory trials, but the confidence intervals are not routinely reported. The challenge of constructing confidence intervals for N_PYNT is due to the fact that exacerbation data or count data in general are usually analyzed using Poisson‐based models such as Poisson or negative binomial regression and the rate ratio is the natural metric for between‐treatment comparison, while N_PYNT is based on rate difference, which is not usually calculated for those models. Therefore, the variance estimates from these analysis models are directly related to the rate ratio rather than the rate difference. In this paper, we propose several methods to construct confidence intervals for the N_PYNT, assuming that the event rates are estimated using Poisson or negative binomial regression models. The coverage property of the confidence intervals constructed with these methods is assessed by simulations. Copyright © 2014 John Wiley & Sons, Ltd.     

排斥还是包容：不同世代在地居民对外来农民工接纳态度的比较实证分析

东莞有为数众多的外来务工者，他们被称为新莞人。调研发现，整体而言，各世代的东莞在地居民对新莞人的接纳态度差异并不算过大，对新莞人也有一定水平的友善包容；60后东莞居民对与新莞人的互动经验评价较为中立，他们同时也认为新莞人在找工作时容易因为身份而受到歧视；80后与90后年轻东莞居民更加正面肯定新莞人是东莞人才资源中重要的一部分；对于新莞人占用本地的社会资源，90后东莞居民持中立态度的比例明显高于其他世代。除了世代之外，学历、工资收入也都是影响东莞本地居民对新莞人接纳态度的个人背景因素。     

关联理论视角下的英语新闻模糊语分析

新闻语言通常被认为是准确的。实际上，大量的模糊语言被应用到新闻中来增强其表述效果。关联理论把语言交际看成一种明示———推理的认知过程，能解释大量的有关于人类语言认知的问题。在收集权威英语新闻语料的基础上，把模糊语这种现象与英语新闻结合起来进行研究，并结合关联理论，分析英语新闻中常出现的模糊数字和英语新闻的标题。     

On the estimation of parameters,survival functions,and hazard rates based on fuzzy life time data

Life time data analysis is regarded as one of the significant out-shoots of statistics. Classical statistical techniques reckon life time observations as precise numbers and solely cover variation among the observations. In fact, there are two types of uncertainty in data: variation among the observations and the fuzziness. To this effect, the analysis techniques, which do not consider fuzziness and are only based on precise life time observations, use incomplete information; hence lead to pseudo results. This study aimed at generalizing parameters estimation, survival functions, and hazard rates for fuzzy life time data.     

High-dimensional Canonical Forest

Recently, a new ensemble classification method named Canonical Forest (CF) has been proposed by Chen et al. [Canonical forest. Comput Stat. 2014;29:849–867]. CF has been proven to give consistently good results in many data sets and comparable to other widely used classification ensemble methods. However, CF requires an adopting feature reduction method before classifying high-dimensional data. Here, we extend CF to a high-dimensional classifier by incorporating a random feature subspace algorithm [Ho TK. The random subspace method for constructing decision forests. IEEE Trans Pattern Anal Mach Intell. 1998;20:832–844]. This extended algorithm is called HDCF (high-dimensional CF) as it is specifically designed for high-dimensional data. We conducted an experiment using three data sets – gene imprinting, oestrogen, and leukaemia – to compare the performance of HDCF with several popular and successful classification methods on high-dimensional data sets, including Random Forest [Breiman L. Random forest. Mach Learn. 2001;45:5–32], CERP [Ahn H, et al. Classification by ensembles from random partitions of high-dimensional data. Comput Stat Data Anal. 2007;51:6166–6179], and support vector machines [Vapnik V. The nature of statistical learning theory. New York: Springer; 1995]. Besides the classification accuracy, we also investigated the balance between sensitivity and specificity for all these four classification methods.     

论汉语双数量的"整体与部分"关系

"整体与部分"是汉语数量之间最常见的关系,它在汉语表达过程中有许多典型的对应式.通过分析这些对应式,发现汉语双数量的这种关系实际有强有弱,同时,某些对应式在具体使用过程中隐喻扩展出了"夸张"关系.     

Approximation of IMSE-optimal Designs via Quadrature Rules and Spectral Decomposition

We address the problem of computing integrated mean-squared error (IMSE) optimal designs for interpolation of random fields with known mean and covariance. We assume that the mean squared error is integrated through a discrete measure and restrict the design space to its support. We show that the IMSE and its approximation by spectral truncation can be easily evaluated, which makes their global minimization affordable. Numerical experiments are carried out that illustrate the effectiveness of the approach.