迷失与探索——评托妮·莫里森的小说《最蓝的眼睛》

文章从《最蓝的眼睛》中佩科拉和克劳蒂亚不同命运的对比出发,对文化传承和社区责任感两方面进行分析,力图揭示莫里森心目中黑人自身存在的种种问题。文章进一步指出:在美国黑人文学发展的历史进程中,莫里森代表着一种从抗议转向自我探索的变化。     

Nonparametric regression for functional data: Automatic smoothing parameter selection

We study regression estimation when the explanatory variable is functional. Nonparametric estimates of the regression operator have been recently introduced. They depend on a smoothing factor which controls its behavior, and the aim of our work is to construct some data-driven criterion for choosing this smoothing parameter. The criterion can be formulated in terms of a functional version of cross-validation ideas. Under mild assumptions on the unknown regression operator, it is seen that this rule is asymptotically optimal. As by-products of this result, we state some asymptotic equivalences for several measures of accuracy for nonparametric estimate of the regression operator. We also present general inequalities for bounding moments of random sums involving functional variables. Finally, a short simulation study is carried out to illustrate the behavior of our method for finite samples.     

A Universal QQ-Plot for Continuous Non-homogeneous Populations

This article presents a universal quantile-quantile (QQ) plot that may be used to assess the fit of a family of absolutely continuous distribution functions in a possibly non-homogeneous population. This plot is more general than probability plotting papers because it may be used for distributions having more than two parameters. It is also more general than standard quantile-quantile plots because it may be used for families of not-necessarily identical distributions. In particular, the universal QQ plot may be used in the context of non-homogeneous Poisson processes, generalized linear models, and other general models.     

Kolmogorov-Smirnov Test Statistic and Critical Values for the Erlang-3 and Erlang-4 Distributions

Following a procedure applied to the Erlang-2 distribution in a recent paper, an adjusted Kolmogorov-Smirnov statistic and critical values are developed for the Erlang-3 and -4 cases using data from Monte Carlo simulations. The test statistic produced features of compactness and ease of implementation. It is quite accurate for sample sizes as low as ten.     

Choice between Semi-parametric Estimators of Markov and Non-Markov Multi-state Models from Coarsened Observations

Abstract.  We consider models based on multivariate counting processes, including multi-state models. These models are specified semi-parametrically by a set of functions and real parameters. We consider inference for these models based on coarsened observations, focusing on families of smooth estimators such as produced by penalized likelihood. An important issue is the choice of model structure, for instance, the choice between a Markov and some non-Markov models. We define in a general context the expected Kullback–Leibler criterion and we show that the likelihood-based cross-validation (LCV) is a nearly unbiased estimator of it. We give a general form of an approximate of the leave-one-out LCV. The approach is studied by simulations, and it is illustrated by estimating a Markov and two semi-Markov illness–death models with application on dementia using data of a large cohort study.     

《板桥杂记》"遗民情怀"辨

《板桥杂记》虽然是一部冶游之书,但值明清交替之际,却渗透着汉文人普遍的“遗民情怀”,仔细剖读《板桥杂记》会发现,这一时期“遗民文人”普遍感伤的常常不属高尚的家国情感,更多的是一种文化失语和个人的挫败感。     

我国师范教育收费历史与思考

我国的师范教育习自西方国家，在特殊的历史背景下师范教育收费几经变化，对师范教育产生了较大影响。在科教兴国的战略背景下，教师是重要的教育资源，师范教育是发展教育事业的基础。研究师范教育收费的变迁，对解决社会主义市场经济体制下教育领域出现的教师资源配置不均衡等问题有所启示。2007年实施的6所部属师范院校师范生免费教育政策，是对历史的创新，也是新时期解决新问题的必然要求。这一政策预期目标的实现，应注意避免负面效应，也需要一系列的配套措施。     

现代经济学多重视角下的信用缺失分析

信用是市场经济中重要且难获得的宝贵资源。鉴于信用缺失对中国市场经济造成的制约，在前人研究的基础上，从产权安排、信息不对称、重复博弈等现代经济学视角探讨信用缺失的内在机理。     

Multi-step forecasts from threshold ARMA models using asymmetric loss functions

The forecasts generation from nonlinear time series models is investigated under general loss functions. After presenting the main results and some relevant features of these functions, the Linex loss has been used to generate multi-step forecasts from threshold autoregressive moving average models showing their main properties and some results connected to a proper transformation of the forecast errors. A simulation exercise highlights interesting properties of the proposed predictors, both in terms of their bias and their distribution, further clarifying how the Linex predictor can be helpful in empirical applications.     

基于消费者损失效用的概率销售策略研究

随着网络信息技术的迅猛发展，概率销售作为一种新颖的销售策略广泛应用于旅游业。在双寡头销售商竞争销售背景下，两销售商分别向损失中性和损失厌恶型消费者销售高档产品和概率产品（中低档产品打包成概率产品）。本文首先运用博弈方法建立了损失中性下的概率销售模型，揭示了产品质量对销售商策略的影响。考虑到消费者在购买概率产品后存在期望损失，我们进一步构建了损失厌恶下的概率销售模型，研究了期望损失对概率销售策略的影响。研究表明期望损失为概率销售商实施概率销售提供了可能性，同时可以增加概率销售商的利润，但可能会损害其竞争者的利益；销售商是否采用概率销售策略主要取决于消费者对购买损失和选择损失的敏感度。最后给出了数值应用结果及管理学启示。