《乌鸦》文本开放性探析

《乌鸦》是难解又极富内涵的一部诗集。这一切源自文本的高度开放性,也是休斯在艺术上苦心追求空白的结果。大幅跳跃的情节、混杂的叙事时间和频移的焦点带给文本众多的空白,造成诗集出现大量的不确定性,从而使它呈现出高度的开放性。文本的开放性使《乌鸦》成了可写性文本,它吸引读者积极参与文本的意义建构,从而在作品与读者之间形成强大的文本意义张力。于是《乌鸦》便因其深厚的意蕴而充满了无尽的魅力。     

A General Construction Method for Five-Level Second-Order Rotatable Designs

Response surface methodology is widely used for developing, improving, and optimizing processes in various fields. In this article, we present a method for constructing second-order rotatable designs in order to explore and optimize response surfaces based on an infinite class of supplementary difference sets. The produced designs achieve both properties of rotatability and estimation efficiency. Also, they possess good predictive properties.     

Confidence intervals for the slope of a linear functional relationship

Creasy (1956) obtained confidence limits for the slope of a bivariate linear structural relationship. This paper shows that her results are also applicable to the linear functional relationship.     

Bayesian estimation of the multidimensional graded response model with nonignorable missing data

A Bayesian approach is developed for analysing item response models with nonignorable missing data. The relevant model for the observed data is estimated concurrently in conjunction with the item response model for the missing-data process. Since the approach is fully Bayesian, it can be easily generalized to more complicated and realistic models, such as those models with covariates. Furthermore, the proposed approach is illustrated with item response data modelled as the multidimensional graded response models. Finally, a simulation study is conducted to assess the extent to which the bias caused by ignoring the missing-data mechanism can be reduced.     

In Memoriam: Martin Taitel,Francis E. McLntyre

A discrete uniform distribution is defined over the integers 1, 2, …, k. Following Tenenbein, who investigated the point estimation of k for a sample drawn without replacement, this paper considers a number of point estimators of k for sampling with replacement and presents conservative confidence sets for k for both methods of sampling.     

Markov chain Monte Carlo estimation of a mixture item response theory model

Markov chain Monte Carlo (MCMC) algorithms have been shown to be useful for estimation of complex item response theory (IRT) models. Although an MCMC algorithm can be very useful, it also requires care in use and interpretation of results. In particular, MCMC algorithms generally make extensive use of priors on model parameters. In this paper, MCMC estimation is illustrated using a simple mixture IRT model, a mixture Rasch model (MRM), to demonstrate how the algorithm operates and how results may be affected by some commonly used priors. Priors on the probabilities of mixtures, label switching, model selection, metric anchoring, and implementation of the MCMC algorithm using WinBUGS are described, and their effects illustrated on parameter recovery in practical testing situations. In addition, an example is presented in which an MRM is fitted to a set of educational test data using the MCMC algorithm and a comparison is illustrated with results from three existing maximum likelihood estimation methods.     

结构方程模式在信度检验中的应用

在对量表数据进行分析前,要先考虑所测量的数值是否可靠,只有信度被接受时,量表的数据分析才是可靠的。国内管理学研究对信度的检验广泛依赖于α系数,但α系数存在要求量表题项受潜在变量影响相等、误差间不能相关、不能对题项进行信度评估等诸多缺陷。随着结构方程模式的发展并被广泛应用,使用结构方程模式对量表进行组合信度（Composite Reliability）和个别项目信度（Individual Item Reliability）检验,可以克服上述缺陷,并为项目修正提供直接依据。     

基于粗集理论的线性回归方法及实证分析

通过分析实际问题中经济变量间往往出现多重共线性的现象,将粗集理论的约简思想引入线性回归分析,提出了基于粗集理论的线性回归模型来解决多重共线性问题,并通过实证分析来验证模型的可行性,为人们进行科学的预测和决策提供了一种新的思想和方法。     

Mimicking Cox-Regression

Abstract

A class of objective functions, related to the Cox partial likelihood, that generates unbiased estimating equations is proposed. These equations allow for estimation of interest parameters when nuisance parameters are proportional to expectations. Examples of the objective functions are applied to binary data with a log-link in three situations: independent observations, independent groups of observations with common random intercept and discrete survival data. It is pointed out that the Peto–Breslow approximation to the partial likelihood with discrete failure times fits a conditional model with a log-link.