H-likelihood: problems and solutions

In recent issues of this journal it has been asserted in two papers that the use of h-likelihood is wrong, in the sense of giving unsatisfactory estimates of some parameters for binary data (Kuk and Cheng, 1999; Waddington and Thompson, 2004) or theoretically unsound (Kuk and Cheng, 1999). We wish to refute both these assertions.     

Detecting active effects in unreplicated designs

Unreplicated factorial designs pose a difficult problem in analysis because there are no degrees of freedom left to estimate the error. Daniel [Technometrics 1 (1959), pp. 311-341] proposed an ingenious graphical method that does not require σ to be estimated. Here we try to put Daniel's method into a formal framework and lift the subjectiveness that carries. A simulation study has been conducted that shows that the proposed method behaves better than Lenth's [Technometrics 31 (1989), pp. 469-473] popular method.     

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.     

战后台湾两次土改不同作用与影响的历史比较

战后我国台湾地区经历了两次性质相同、目标各异的土地改革,迅速改变了传统的封建土地所有制,促进了台湾政治的稳定和现代经济的起飞。但由于时代条件对土地政策的要求不同,台湾的两次土改所发挥的作用与影响也各不相同,给人们留下了深刻的启示。     

Evaluating the Efficacy of a Mental Models Approach for Improving Occupational Chemical Risk Protection

Chemical risk protection in the workplace relies partly on informing workers about possible risks using material safety data sheets (MSDS). This article reports on phase 2 of a project (phase 1 reported in Cox et al.), which employed a mental models approach to improve on data sheets as communicative interventions for perchloroethylene in dry cleaning and rosin-based solder flux in the electronics industry within small businesses in the United Kingdom (small enterprises (SEs) < 25 employees in the workplace). It focuses on the efficacy of a multimethod evaluation strategy to assess (1) the capacity of a mental models approach to yield contextually relevant data for intervention design and (2) the effectiveness of the strategy itself in validating the mental models data. The evaluation was conducted using postal questionnaires and semi-structured verbal protocols to provide responses to the alternative intervention content and to prioritize risk messages. User discussion groups were then employed, particularly as a means of establishing whether contextual information could be obtained that would differ qualitatively from the kind elicited through individual (semi) structured methods. We conclude that the mental models approach as part of an iterative process including systematic multimethod evaluation is successful in supporting the design of relevant communications to the users of chemicals. The overall viability of communicative interventions in the context of health and safety in small businesses remains in question. Future research might aim to develop a more holistic approach to interventions in complex occupational contexts.     

跨国公司内部贸易对我国经济的负面影响探析

跨国公司内部贸易会对我国经济产生诸多负面影响,主要表现在通过转移定价谋取超额利润、垄断先进技术、加深产业结构的低级化、干扰正常的国际贸易活动、冲击国家经济主权等方面,因此应该采取一些措施,比如控制跨国公司转移定价、加快自主科技的研究与开发、规范跨国公司投资领域、培育大型企业集团、健全法制等等,以此最大限度地降低跨国公司内部贸易对我国经济的负面影响.     

供应链协调机制的研究

本文对供应链的协调机制进行系统的论述,以往很少有文献涉及。首先对供应链失调的原因、阻碍供应链协调的因素以及失调对运营造成的影响进行简单的分析;然后介绍了各种供应链的协调机制;最后,对协调供应链的策略方法进行了简要的阐述。     

浅谈网络经济对中国企业文化建设的负面影响及对策研究

网络经济是21世纪的新兴经济形态,它的出现既为全球经济发展带来了一股新鲜的活力,也对人类的社会生活产生了诸多方面的负面影响.网络经济中人的行为和观念的变化直接影响了网络经济下企业文化的建设.本文分析了网络经济对中国企业文化建设的负面影响,并探讨了减轻负面影响的策略.     

Efficient Estimation in Marginal Partially Linear Models for Longitudinal/Clustered Data Using Splines

Abstract.  We consider marginal semiparametric partially linear models for longitudinal/clustered data and propose an estimation procedure based on a spline approximation of the non-parametric part of the model and an extension of the parametric marginal generalized estimating equations (GEE). Our estimates of both parametric part and non-parametric part of the model have properties parallel to those of parametric GEE, that is, the estimates are efficient if the covariance structure is correctly specified and they are still consistent and asymptotically normal even if the covariance structure is misspecified. By showing that our estimate achieves the semiparametric information bound, we actually establish the efficiency of estimating the parametric part of the model in a stronger sense than what is typically considered for GEE. The semiparametric efficiency of our estimate is obtained by assuming only conditional moment restrictions instead of the strict multivariate Gaussian error assumption.     

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.