Remove unwanted variation retrieves unknown experimental designs

Remove unwanted variation (RUV) is an estimation and normalization system in which the underlying correlation structure of a multivariate dataset is estimated from negative control measurements, typically gene expression values, which are assumed to stay constant across experimental conditions. In this paper we derive the weight matrix which is estimated and incorporated into the generalized least squares estimates of RUV-inverse, and show that this weight matrix estimates the average covariance matrix across negative control measurements. RUV-inverse can thus be viewed as an estimation method adjusting for an unknown experimental design. We show that for a balanced incomplete block design (BIBD), RUV-inverse recovers intra- and interblock estimates of the relevant parameters and combines them as a weighted sum just like the best linear unbiased estimator (BLUE), except that the weights are globally estimated from the negative control measurements instead of being individually optimized to each measurement as in the classical, single measurement BIBD BLUE.     

Asymptotically optimal Berry-Esseen-type bounds for distributions with an absolutely continuous part

Recursive and closed form upper bounds are offered for the Kolmogorov and the total variation distance between the standard normal distribution and the distribution of a standardized sum of n independent and identically distributed random variables. The method employed is a modification of the method of compositions along with Zolotarev's ideal metric. The approximation error in the CLT obtained vanishes at a rate O(n^−k/2+1), provided that the common distribution of the summands possesses an absolutely continuous part, and shares the same k−1 (k?3) first moments with the standard normal distribution. Moreover, for the first time, these new uniform Berry-Esseen-type bounds are asymptotically optimal, that is, the ratio of the true distance to the respective bound converges to unity for a large class of distributions of the summands. Thus, apart from the correct rate, the proposed error estimates incorporate an optimal asymptotic constant (factor). Finally, three illustrative examples are presented along with numerical comparisons revealing that the new bounds are sharp enough even to be used in practical statistical applications.     

写实主义理论在日本近代的发展与变异

坪内逍遥提出的写实主义理论对日本近代文学的影响,一方面表现在催生了以二叶亭四迷为代表的现实主义文学的诞生,一方面为长谷川天溪等代表的自然主义理论提供了某些方法论的基础,从而引起人们对写实主义与自然主义在概念理解上的分歧。写实主义理论之所以会有这样的发展与变异,是因为日本近代的写实主义与左拉的自然主义都与实证主义哲学有着或明或暗的关系。     

The Apparent‐Time Construct and stable variation: Final /z/ devoicing in northwestern Indiana1

As real‐time language data becomes increasingly available for sociolinguistic research, a growing number of studies are benefitting from it in order to study language changes in progress, some of which even explicitly seek to scrutinize the Apparent‐Time Construct itself. Vanishingly few real‐time studies, however, have focused specifically on stable sociolinguistic variables, leaving an important gap in our understanding of the Apparent‐Time Construct's abilities to model real‐time facts. In an effort to address this gap, the present study analyzes a presumably stable sociolinguistic variable – final /z/ devoicing – in extreme northwestern Indiana through real and apparent time. A series of Varbrul analyses indicate that this variable is, indeed, stable throughout the 20 years of real time covered by the data and that its stability is successfully modeled in apparent time. Additionally, similarities in /z/ devoicing between this community and some other communities where it has also been studied are identified and discussed.     

From sociolinguistic variation to socially strategic stylisation1

This article investigates the indexical relation between language, interactional stance and social class. Quantitative sociolinguistic analysis of a linguistic variable (the first person possessive singular) is combined with interactional analysis of the way one particular variant (possessive ‘me’, as in Me pencil's up me jumper) is used by speakers in ‘stylised’ interactional performances. The aim of this analysis is to explore: (1) how possessive ‘me’ is implicated in the construction and management of local identities and relationships; and (2) how macro‐social categories, such as social class, relate to linguistic choice. The data for this analysis comes from an ethnographic study of the language practices of nine‐ to ten‐year‐old children in two socially‐differentiated primary schools in north‐east England. A secondary aim of the article is to spotlight the sociolinguistic sophistication of these young children, in particular, the working‐class participants, who challenge the notion that the speech of working‐class children is in any way ‘impoverished’.     

Logistic模型的系数比较问题及解决策略：一个综述

本文介绍了Logistic模型中经常被忽视的系数比较问题,包括同一样本在不同模型间的系数比较和在不同样本或子群体间的模型系数比较。研究者往往会沿袭线性回归模型的系数比较方法,但这是不恰当的,因为Logistic模型存在未被观测到的异质性（残差变异）问题,所以模型间系数不能进行简单的直接比较。根据已有研究,本文总结了解决这一问题的五种策略,分别是“y*标准化”、KHB分解、异质选择模型、平均偏效应（APE）和线性概率模型（LPM）,然后利用CGSS2006数据,以教育递进率模型为例,比较这些解决策略的异同,最后总结这些策略的特征及适用情况。     

Value orientations of social welfare policy structures

Substantial literature exists around the variation of welfare policy development in liberal democracies. The contrast of the American welfare state to those in Europe has sparked significant analytical literature about which factors are most significant in the variation. The literature extensively examines many of these factors but has neglected the significance of social values. This article discusses values and policy development as a foundation for further studies linking specific values to policy and institutional development. First, I discuss theorists who have identified value orientation as significant to welfare state variation; second, I review the major comparative welfare state literature. Finally, I discuss the major variation categories through the lens of social values by identifying the significant value orientation of sample policy structures. Comparative welfare state literature benefits from elucidating the values orientation of welfare policies that define the welfare state typological categories. Including the role of social values in welfare state comparisons promotes greater understanding of the origins and trajectory of current policy. Key Practitioner Message: ● Increase understanding of welfare state variation factors; ● Frame questions about social values reflected in social policy.     

Methods to Distinguish Between Polynomial and Exponential Tails

Two methods to distinguish between polynomial and exponential tails are introduced. The methods are based on the properties of the residual coefficient of variation for the exponential and non‐exponential distributions. A graphical method, called a CV‐plot, shows departures from exponentiality in the tails. The plot is applied to the daily log‐returns of exchange rates of US dollar and Japanese yen. New statistics are introduced for testing the exponentiality of tails using multiple thresholds. They give better control of the significance level than previous tests. The powers of the new tests are compared with those of some others for various sample sizes.     

次分数布朗运动下带交易费用的备兑权证定价

为了体现金融资产的长记忆性,采用次分数布朗运动刻画备兑权证标的资产价格变化的行为模式。利用随机分析理论和偏微分方程方法,建立了次分数布朗运动下带交易费用的备兑权证定价模型,进一步研究了定价模型的参数估计问题。最后,采用我国权证市场实际数据进行了实证分析,通过比较不同定价模型的结果说明了长记忆性和交易费用对定价结果有着显著的影响。