Likelihood Inference for Unions of Interacting Discs

Abstract. This is probably the first paper which discusses likelihood inference for a random set using a germ‐grain model, where the individual grains are unobservable, edge effects occur and other complications appear. We consider the case where the grains form a disc process modelled by a marked point process, where the germs are the centres and the marks are the associated radii of the discs. We propose to use a recent parametric class of interacting disc process models, where the minimal sufficient statistic depends on various geometric properties of the random set, and the density is specified with respect to a given marked Poisson model (i.e. a Boolean model). We show how edge effects and other complications can be handled by considering a certain conditional likelihood. Our methodology is illustrated by analysing Peter Diggle's heather data set, where we discuss the results of simulation‐based maximum likelihood inference and the effect of specifying different reference Poisson models.     

Modeling longitudinal count data with dropouts

This paper explores the utility of different approaches for modeling longitudinal count data with dropouts arising from a clinical study for the treatment of actinic keratosis lesions on the face and balding scalp. A feature of these data is that as the disease for subjects on the active arm improves their data show larger dispersion compared with those on the vehicle, exhibiting an over‐dispersion relative to the Poisson distribution. After fitting the marginal (or population averaged) model using the generalized estimating equation (GEE), we note that inferences from such a model might be biased as dropouts are treatment related. Then, we consider using a weighted GEE (WGEE) where each subject's contribution to the analysis is weighted inversely by the subject's probability of dropout. Based on the model findings, we argue that the WGEE might not address the concerns about the impact of dropouts on the efficacy findings when dropouts are treatment related. As an alternative, we consider likelihood‐based inference where random effects are added to the model to allow for heterogeneity across subjects. Finally, we consider a transition model where, unlike the previous approaches that model the log‐link function of the mean response, we model the subject's actual lesion counts. This model is an extension of the Poisson autoregressive model of order 1, where the autoregressive parameter is taken to be a function of treatment as well as other covariates to induce different dispersions and correlations for the two treatment arms. We conclude with a discussion about model selection. Published in 2009 by John Wiley & Sons, Ltd.     

The Social Ecology of Race and Ethnicity School Achievement Gaps: Economic,Neighborhood, School,and Family Factors

This study used a nationally representative sample of middle and high school students to examine the degree to which economic, neighborhood, school, and family factors contributed to three points on a proposed school outcome continuum: (1)avoidance of problem behavior, (2)sense of school coherence, and (3)grades. Multilevel models were employed to account for the clustering of students inside schools. Results suggested that though family and neighborhood social factors contribute to variance in school outcomes, family and neighborhood economic factors revealed the largest potential to explain and therefore present leverage points to reduce race and ethnicity achievement gaps.     

An Evaluation of Behavioral Health Compliance and Microbial Risk Factors on Student Populations Within a High-Density Campus

Abstract

Objective: The aim of this Canadian study was to assess student behavioral response to disease transmission risk, while identifying high microbial deposition/transmission sites. Participants: A student survey was conducted during October 2009. Methods: The methods included a survey of students to assess use of health services, vaccination compliance, and hygiene along with a microbial analysis of potential transmission sites targeting specific residence buildings on campus. Results: Results indicated that most students maintained that they were worried about H1N1 and reported making changes in hygienic behavior, with the majority not planning to be vaccinated. The microbial analysis indicated contamination of fomites in co-ed residences to be higher than either male or female student residences. Conclusions: A consideration of physical space along with behavioral factors is required in order to properly assess risk pathways in the establishment of an evidence-based infection control plan for universities and their contiguous communities.     

基于“大话”文化消极影响下的高校德育

＂大话＂文化解构崇高、讽刺搞笑的特点带来了青年学子政治观念趋向淡漠、集体责任感弱化、远大理想迷失、追求标新立异和自我意志崇拜等消极方面的影响。高校应该在教育方法上,尊重学生个性发展要求,并因材施教、加强引导;在教育环境上,加强道德实践教育,推进新时代的德育美育教育;在教育原则上,重新厘定审视师生关系,发展交往式德育教育模式,逐渐消除＂大话＂文化对高校德育教育的消极影响。     

中国企业出口与生产率关系实证研究——对制造业企业自我选择效应和出口中学效应的分析

运用2005—2008年中国14个制造业企业面板数据,分析企业出口的自我选择效应和出口中学效应,结果表明:中国制造业企业出口与生产率的关系违背异质性企业贸易模型,自我选择效应不显著,并且存在"生产率悖论";出口中学效应也不显著。虽然出口企业的生产率与出口规模正相关,但在控制其他影响出口规模的变量后,生产率与出口规模则呈现负相关;在控制其他影响生产率的变量后,出口规模与生产率同样也会呈现负相关。中国企业出口的自我选择效应不显著的原因在于其加工贸易等现实条件与经典理论假设的背离;而中国企业出口中学效应不明显的重要原因则在于其自我选择效应的不显著和规模报酬递减。     

A Note on the Lower Bounds on Maximum Number of Clear Two-Factor Interactions for (2 m−p III) and (2 m−p IV) Designs

ABSTRACT

In the reliability analysis of mechanical repairable equipment subjected to reliability deterioration with operating time, two forms of the non-homogeneous Poisson processes, namely the Power-Law (PL) and the Log-Linear (LL) model, have found general acceptance in the literature. Inferential procedures, conditioned on the assumption of the PL or LL model, underestimate the overall uncertainty about a quantity of interest because the PL and LL models can provide different estimates of the quantity of interest, even when both of them adequately fit the observed data. In this paper, a composite estimation procedure, which uses the PL and LL models as competing models, is proposed in the framework of Bayesian statistics, thus allowing the uncertainty involved in model selection to be considered. A model-free approach is then proposed for incorporating technical information on the failure mechanism into the inferential procedure. Such an approach, which is based on two model-free quantities defined irrespectively of the functional form of the failure model, prevents that the prior information on the failure mechanism can improperly introduce prior probabilities on the adequacy of each model to fit the observed data. Finally, numerical applications are provided to illustrate the proposed procedures.     

Measures of Restoration in Geriatric Care Residences

Abstract

In this paper, we have studied how elderly people's frame of mind influences their response to experiencing nature, measured in terms of blood pressure, pulse rate, concentration and results from protocols. Two theories concerning the importance of psychological balance have been put forward earlier by Lawton and Kiiller, both of whom maintain that the surrounding everyday environment is one of the keys to a harmonious existence. We present findings supporting the theory that the positive experience of natural surroundings per se has a balancing and healing effect.

We have found that the people most affected by their surroundings are those with the greatest psycho-physiological imbalance. When the balance tilts, the balancing effect of the green experience can restore the individual to a state of better harmony. Time spent in the outdoors is, thus, especially important for individuals who easily lose their equilibrium or find it difficult to make compensatory changes to restore harmony on their own.

The research project is an intervention study in which fifteen elderly individuals living at a home for very old people participated. Their power of concentration, blood pressure and heart rate were measured before and after an hour of rest in a garden and in an indoor setting, respectively. Seven elderly people were randomly chosen to have their first series of tests in a garden, while eight elderly people had their first series of tests indoors. The results indicate that power of concentration increases for very old people after a visit in a garden outside the geriatric home in which they live, as compared to resting indoors in their favorite room.

The results did not show any effects on blood pressure or heart rate.

However, when we compared these results with the background variables, we found interesting correlations. Background variables included how often they took part in social activities, showed helpfulness toward other residents in group activities and tolerance/critique of other residents. After a factor analysis, the background variables formed three distinct factors, one of which showed significant correlation with blood pressure and heart rate: the factor psycho-physiological balance, with the variables “degree of tolerance,” “degree of helpfulness” and “frequency of hospital visits.” Elderly people with low psycho-physiological balance, that is, who had low tolerance of other residents, were not helpful in group activities and had a high frequency of hospital visits, were most affected by a stay in a garden, as could be measured in changes in heart rate and blood pressure. The results may be interpreted as showing that a garden can restore an elderly person with low psycho-physiological balance to a state of better harmony.

The present study show, first, that an outdoor visit is important for recovery from stress and fatigue and, second, that the improvement is especially significant for the most susceptible. Thus, it is of particular importance that weak groups, such as elderly in great need of care, have access to an outdoor space. Such groups are likely to include many people who are in psycho-physiological imbalance.     

Optimal repeated measurements designs for comparing test treatments with a control

A-optimal and mv optimal repeated measurments designs for comparing serveral test treatments with a control are considered. the models considered are basically of two types: without preperides and the cirular model. It is shown known that some known strongly balanced uniform repeated measurements designs can be modified to obtain optimal designs for this problem. Some other methods of finding optimal designs are also given.     

单面与双面信息广告重复效应的实证研究

通过引入企业道德感知变量,并在整合最优唤醒理论、加工流畅模型、归因理论和两因素理论的基础上,深入剖析了单、双面信息广告重复效应的差异。研究结果表明:双面信息广告比单面信息广告加工更困难,但消费者对其广告正确回忆率更高,广告反应也更积极。单面信息广告的重复效应呈现先增后减的倒U趋势,而双面信息广告的重复效应呈单调递增趋势,疲劳效应延迟出现。消费者对企业道德感知的差异在很大程度上决定了单、双面信息广告重复效应的差异。