Bootstrapping data with multiple levels of variation

The authors consider general estimators for the mean and variance parameters in the random effect model and in the transformation model for data with multiple levels of variation. They show that these estimators have different distributions under the two models unless all the variables have Gaussian distributions. They investigate the asymptotic properties of bootstrap procedures designed for the two models. They also report simulation results and illustrate the bootstraps using data on red spruce trees.     

A Mixed Model Approach for Geoadditive Hazard Regression

Abstract.  Mixed model based approaches for semiparametric regression have gained much interest in recent years, both in theory and application. They provide a unified and modular framework for penalized likelihood and closely related empirical Bayes inference. In this article, we develop mixed model methodology for a broad class of Cox-type hazard regression models where the usual linear predictor is generalized to a geoadditive predictor incorporating non-parametric terms for the (log-)baseline hazard rate, time-varying coefficients and non-linear effects of continuous covariates, a spatial component, and additional cluster-specific frailties. Non-linear and time-varying effects are modelled through penalized splines, while spatial components are treated as correlated random effects following either a Markov random field or a stationary Gaussian random field prior. Generalizing existing mixed model methodology, inference is derived using penalized likelihood for regression coefficients and (approximate) marginal likelihood for smoothing parameters. In a simulation we study the performance of the proposed method, in particular comparing it with its fully Bayesian counterpart using Markov chain Monte Carlo methodology, and complement the results by some asymptotic considerations. As an application, we analyse leukaemia survival data from northwest England.     

陕北燎百病风俗的地域含义探析

岁时风俗是一种现实的民俗文化现象,同时也是历史文化现象的积淀,产生于特定的地理环境之中。陕北地处黄土高原地区农牧交错地带,历史上先后在这里生活过的民族众多,相互交流,故其燎百病风俗深受汉族农耕文化和北方游牧文化的影响,包含着鲜明的农本价值指向和强烈的除病驱邪作用。     

《诗经》评点三种来源考论

自明末以来的《诗经》评本约存三十种,按其来源可分为原创评点、转录评点、嫁接评点三种。本文在对现存评本进行考察梳理的基础上,对这三种来源进行了阐说。     

顶部送风方腔内混合对流换热的数值研究

采用非稳态数学模型对具有对称和非对称结构的顶部送风二维方腔内混合对流流场与温度场进行了数值求解.数值计算中控制参数Ra取为固定值106,Re在1 000~3 000范围内变化.数值结果显示,随Re的增大,具有对称结构问题的数值解会分别出现定常解、周期性振荡解和非周期性振荡解;而对于非对称结构问题,数值解的最大网格Pe虽然大于对称结构问题的最大网格Pe,数值解是定常的,并未发生解的振荡.因此,判明具有对称结构的顶部送风二维方腔内混合对流问题数值解的振荡是客观存在的物理振荡,而非数值方法不稳定所引起的数值振荡.     

混合拟单调系统的全局渐近稳定性

本文引进混合单调流和单调拟合流的概念,利用单调流理论研究混合拟单调系统,对于合作、竞争和捕食一被捕食三种关系并存的生态系统,我们得到其共生状态全局渐近稳定的判别准则.     

酯化反应研究（Ⅱ）混合催化剂催化苯甲酸乙酯的快速合成

本报道用混合催化剂PPDS－H－BGA，快速合成苯甲酸乙酯。实验结果表明，在混合催化剂PPDS－H－BGA存在下，苯甲酸与乙醇的回流反应，仅15分钟时间，制得苯甲酯乙酯，其产率达到96．7％。     

Conditional Functional Principal Components Analysis

Abstract.  This work proposes an extension of the functional principal components analysis (FPCA) or Karhunen–Loève expansion, which can take into account non-parametrically the effects of an additional covariate. Such models can also be interpreted as non-parametric mixed effect models for functional data. We propose estimators based on kernel smoothers and a data-driven selection procedure of the smoothing parameters based on a two-step cross-validation criterion. The conditional FPCA is illustrated with the analysis of a data set consisting of egg laying curves for female fruit flies. Convergence rates are given for estimators of the conditional mean function and the conditional covariance operator when the entire curves are collected. Almost sure convergence is also proven when one observes discretized noisy sample paths only. A simulation study allows us to check the good behaviour of the estimators.     

ASYMPTOTIC LIKELIHOOD APPROXIMATIONS USING A PARTIAL LAPLACE APPROXIMATION

Elimination of a nuisance variable is often non‐trivial and may involve the evaluation of an intractable integral. One approach to evaluate these integrals is to use the Laplace approximation. This paper concentrates on a new approximation, called the partial Laplace approximation, that is useful when the integrand can be partitioned into two multiplicative disjoint functions. The technique is applied to the linear mixed model and shows that the approximate likelihood obtained can be partitioned to provide a conditional likelihood for the location parameters and a marginal likelihood for the scale parameters equivalent to restricted maximum likelihood (REML). Similarly, the partial Laplace approximation is applied to the t‐distribution to obtain an approximate REML for the scale parameter. A simulation study reveals that, in comparison to maximum likelihood, the scale parameter estimates of the t‐distribution obtained from the approximate REML show reduced bias.     

英文商标和英文商标的命名策略

英语作为语言帝国主义 ,它侵占到了商品流通领域中的一个重要方面 :商标的命名。商标是生产者和经营者的唯一最有价值的资产。在当今社会中 ,英文商标的命名在全球经济日趋一体化中显得十分重要。英文商标的命名当然有其英文表达的固有特点 ,但是它有些命名的战略需要人们不断研究。文章根据作者在澳大利亚对世界著名商品的英文商标在市场上的知名度所作的实地考察素材 ,研究了英文商标的重要性和英文商标命名中的一些规律性的东西 ,提出了英文商标命名的策略