公益广告的攻心策略

公益广告的效果研究一直处于广告研究的滞后阶段。目前的公益广告存在着“隔岸观火”和“隔靴搔痒”两大病症。问题的关键是广告诉求与受众的相关度不高。对症下药,提高公益广告效果的策略有三:真实再现、指向明确和对比联想。     

Extremes of Markov chains with tail switching potential

Summary.  A recent advance in the utility of extreme value techniques has been the characteri- zation of the extremal behaviour of Markov chains. This has enabled the application of extreme value models to series whose temporal dependence is Markovian, subject to a limitation that prevents switching between extremely high and extremely low levels. For many applications this is sufficient, but for others, most notably in the field of finance, it is common to find series in which successive values switch between high and low levels. We term such series Markov chains with tail switching potential, and the scope of this paper is to generalize the previous theory to enable the characterization of the extremal properties of series displaying this type of behaviour. In addition to theoretical developments, a modelling procedure is proposed. A simulation study is made to assess the utility of the model in inferring the extremal dependence structure of autoregressive conditional heteroscedastic processes, which fall within the tail switching Markov family, and generalized autoregressive conditional heteroscedastic processes which do not, being non-Markov in general. Finally, the procedure is applied to model extremal aspects of a financial index extracted from the New York Stock Exchange compendium.     

Conditional statistical inference and quantification of relevance

Summary. We argue that it can be fruitful to take a predictive view on notions such as the precision of a point estimator and the confidence of an interval estimator in frequentist inference. This predictive approach has implications for conditional inference, because it immediately allows a quantification of the concept of relevance for conditional inference. Conditioning on an ancillary statistic makes inference more relevant in this sense, provided that the ancillary is a precision index. Not all ancillary statistics satisfy this demand. We discuss the problem of choice between alternative ancillary statistics. The approach also has implications for the best choice of variance estimator, taking account of correlations with the squared error of estimation itself. The theory is illustrated by numerous examples, many of which are classical.     

绿色产品定格的博弈分析

自 2 0世纪 90年代以来消费者越来越强烈地关注环境问题 ,绿色消费成为消费者追求的消费模式。合理的定价是绿色产品能否占领市场的关键。利用Hotelling模型对绿色产品的定价进行了相应的分析 ,得到“绿色产品的最优定价与提供具有基本效用的生产成本呈正相关的关系 ,与消费者的绿色效用系数呈正相关的关系 ,与市场中存在的绿色消费者人数呈正相关关系”的结论。     

高可用性双机系统的有限自动机

介绍了提供高可用性的双机系统的原理、部署和体系结构;定义了双机系统各部件功能,描述了子系统间的接口,给出了该双机系统的有限自动机。该自动机具有有限数目的内部状态,模拟了双机系统的工作原理及内部各状态的相互转化,描述了服务切换、进程与服务监控、心跳侦测、网络参考点侦测等过程,为双机系统的行为描述和结构设计提供了理论依据和论证。     

物流服务品质及其定量分析

物流服务品质是物流供需均衡理论分析的重要媒介,其内涵可以界定为依托于物流过程所体现出来的、能被消费者感知的、物流服务的质量特征。分析指出物流服务品质主要由时效性、可靠性、灵活性、安全性以及经济性等五个方面内容构成,并通过设置指标体系加以量化描述,运用层次分析法进行综合评价。结果表明,物流企业可以通过对物流服务品质的合理定位,更好地满足用户需求,并促进物流供需均衡的实现。     

居民生活质量的因子分析与综合评价

选择现阶段与人们生活质量密切相关的指标,构建了研究居民生活质量的指标体系。选用2004年31个省市的截面数据,采用因子分析法对31个省市居民生活质量进行了分析,并依据因子分析结果进行了综合评价,得到了现阶段提高居民生活质量的有效措施。     

基于Malmquist指数的客车企业效率研究

汽车行业是中国加入WTO后受冲击最大的行业之一。正确估计作为公共交通主要工具的客车企业的效率是研究、规划、调控该行业发展的重要依据。本文运用基于DEA模型的Malmquist研究了2002年到2005年中国客车类上市公司纯技术效率、规模效率、技术进步率和全要素生产率的变化。结果表明面对外资企业的冲击,多数企业的发展高于人们的预期,在激烈的竞争中保持住了竞争优势,并实现了一定程度的生产率提高,只是受发展环境的限制,提高速度低于国民经济增长速度。     

Using a mixture model for multiple imputation in the presence of outliers: the 'Healthy for life' project

Summary.  We consider the problem of obtaining population-based inference in the presence of missing data and outliers in the context of estimating the prevalence of obesity and body mass index measures from the 'Healthy for life' study. Identifying multiple outliers in a multivariate setting is problematic because of problems such as masking, in which groups of outliers inflate the covariance matrix in a fashion that prevents their identification when included, and swamping, in which outliers skew covariances in a fashion that makes non-outlying observations appear to be outliers. We develop a latent class model that assumes that each observation belongs to one of K unobserved latent classes, with each latent class having a distinct covariance matrix. We consider the latent class covariance matrix with the largest determinant to form an 'outlier class'. By separating the covariance matrix for the outliers from the covariance matrices for the remainder of the data, we avoid the problems of masking and swamping. As did Ghosh-Dastidar and Schafer, we use a multiple-imputation approach, which allows us simultaneously to conduct inference after removing cases that appear to be outliers and to promulgate uncertainty in the outlier status through the model inference. We extend the work of Ghosh-Dastidar and Schafer by embedding the outlier class in a larger mixture model, consider penalized likelihood and posterior predictive distributions to assess model choice and model fit, and develop the model in a fashion to account for the complex sample design. We also consider the repeated sampling properties of the multiple imputation removal of outliers.     

地方大学科技服务策略探讨

为地方经济发展提供智力支持和科技服务是地方大学的重要价值之一．在地方经济社会进行快速转型的形势面前，地方大学应以“立足地方、主动适应、把握形势、积极引导”为基本的科技服务策略，充分利用自身的科研资源优势，全面服务于地方的经济转轨、产业调整和高新技术发展．