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101.
This paper studies optimum designs for linear models when the errors are heteroscedastic. Sufficient conditions are given in order to obtainD-, A- andE-optimum designs for a complete regression model from partial optimum designs for some sub-parameters. A result about optimality for a complete model from the optimality for the submodels is included. Supported by Junta de Andalucía, research group FQM244.  相似文献   
102.
The authors extend the block external bootstrap to partially linear regression models with strongly mixing, nonstationary error terms. In addition to providing an approximate distribution for the semiparametric least square estimator of the parametric component, they propose a consistent estimator of the co‐variance matrix of this estimator.  相似文献   
103.
Consider a website and the surfers visiting its pages. A typical issue of interest, for example while monitoring an advertising campaign, concerns whether a specific page has been designed successfully, i.e. is able to attract surfers or address them to other pages within the site. We assume that the surfing behaviour is fully described by the transition probabilities from one page to another, so that a clickstream (sequence of consecutively visited pages) can be viewed as a finite-state-space Markov chain. We then implement a variety of hierarchical prior distributions on the multivariate logits of the transition probabilities and define, for each page, a content effect and a link effect. The former measures the attractiveness of the page due to its contents, while the latter signals its ability to suggest further interesting links within the site. Moreover, we define an additional effect, representing overall page success, which incorporates both effects previously described. Using WinBUGS, we provide estimates and credible intervals for each of the above effects and rank pages accordingly.  相似文献   
104.
The quantification of the relationship between the amount of microbial organisms ingested and a specific outcome such as infection, illness, or mortality is a key aspect of quantitative risk assessment. A main problem in determining such dose-response models is the availability of appropriate data. Human feeding trials have been criticized because only young healthy volunteers are selected to participate and low doses, as often occurring in real life, are typically not considered. Epidemiological outbreak data are considered to be more valuable, but are more subject to data uncertainty. In this article, we model the dose-illness relationship based on data of 20 Salmonella outbreaks, as discussed by the World Health Organization. In particular, we model the dose-illness relationship using generalized linear mixed models and fractional polynomials of dose. The fractional polynomial models are modified to satisfy the properties of different types of dose-illness models as proposed by Teunis et al . Within these models, differences in host susceptibility (susceptible versus normal population) are modeled as fixed effects whereas differences in serovar type and food matrix are modeled as random effects. In addition, two bootstrap procedures are presented. A first procedure accounts for stochastic variability whereas a second procedure accounts for both stochastic variability and data uncertainty. The analyses indicate that the susceptible population has a higher probability of illness at low dose levels when the combination pathogen-food matrix is extremely virulent and at high dose levels when the combination is less virulent. Furthermore, the analyses suggest that immunity exists in the normal population but not in the susceptible population.  相似文献   
105.
《万国公报》是晚清时期一份颇具影响的刊物。它的出名,既与美国监理会传教士林乐知密不可分,又与供职于其间的华人编辑息息相关。文章详细论述了这一群体,并分析了这批华人编辑在供职《万国公报》时期的活动和言论。  相似文献   
106.
线性科学与非线性科学哲学思想研究   总被引:1,自引:0,他引:1  
在简述线性科学的科学基础、科学方法和哲学思想的基础上,研究了非线性科学的科学基础、科学方法和哲学思想,其中较为详细地探讨了非线性科学的哲学范畴和哲学思想,认为要多角度观察事物,要从变化中认识主要矛盾,事物的发展是多元竞争与协同的统一,这一结果将对非线性科学的哲学思想的进一步研究有一定的启发和借鉴作用。  相似文献   
107.
独立学院是我国现行高教体制的突破与革新,既不同于传统的公办普通高校,又有别于已有的民办高校和职业技术学院。随着高等教育大众化,面对着竞争愈演愈烈的人才市场,独立学院如何在高等教育竞争中的勇立潮头,赢得一席之地,必须就“独立学院应用性人才培养模式的构建”进行认真的研究与探索,根据社会对人才需求呈现出多样化趋势的实际,找准学院定位,明确办学理念,理清办学思路,创新培养模式,全力打造“应用性”人才。  相似文献   
108.
儒学的伦理思想是中国几千年来各封建王朝所奉行的道德标准,它影响着社会生活的各个方面。建筑是文化的载体,不同时期的建筑体现着不同时期的主流文化。中国传统建筑充分体现了这种等级分明的伦理道德观,而现代建筑同样也体现出现代社会的伦理与道德观念,居住文化的变迁体现出伦理思想的嬗变。  相似文献   
109.
This paper develops a likelihood‐based method for fitting additive models in the presence of measurement error. It formulates the additive model using the linear mixed model representation of penalized splines. In the presence of a structural measurement error model, the resulting likelihood involves intractable integrals, and a Monte Carlo expectation maximization strategy is developed for obtaining estimates. The method's performance is illustrated with a simulation study.  相似文献   
110.
Summary. Standard goodness-of-fit tests for a parametric regression model against a series of nonparametric alternatives are based on residuals arising from a fitted model. When a parametric regression model is compared with a nonparametric model, goodness-of-fit testing can be naturally approached by evaluating the likelihood of the parametric model within a nonparametric framework. We employ the empirical likelihood for an α -mixing process to formulate a test statistic that measures the goodness of fit of a parametric regression model. The technique is based on a comparison with kernel smoothing estimators. The empirical likelihood formulation of the test has two attractive features. One is its automatic consideration of the variation that is associated with the nonparametric fit due to empirical likelihood's ability to Studentize internally. The other is that the asymptotic distribution of the test statistic is free of unknown parameters, avoiding plug-in estimation. We apply the test to a discretized diffusion model which has recently been considered in financial market analysis.  相似文献   
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