Bayesian networks for imputation

Summary.  Bayesian networks are particularly useful for dealing with high dimensional statistical problems. They allow a reduction in the complexity of the phenomenon under study by representing joint relationships between a set of variables through conditional relationships between subsets of these variables. Following Thibaudeau and Winkler we use Bayesian networks for imputing missing values. This method is introduced to deal with the problem of the consistency of imputed values: preservation of statistical relationships between variables ( statistical consistency ) and preservation of logical constraints in data ( logical consistency ). We perform some experiments on a subset of anonymous individual records from the 1991 UK population census.     

The evaluation of DNA evidence in pedigrees requiring population inference

Summary. The evaluation of nuclear DNA evidence for identification purposes is performed here taking account of the uncertainty about population parameters. Graphical models are used to detail the hypotheses being debated in a trial with the aim of obtaining a directed acyclic graph. Graphs also clarify the set of evidence that contributes to population inferences and they also describe the conditional independence structure of DNA evidence. Numerical illustrations are provided by re-examining three case-studies taken from the literature. Our calculations of the weight of evidence differ from those given by the authors of case-studies in that they reveal more conservative values.     

微机辅助设计机械产品装配图

本文提出一个在微机上设计机械产品装配图的方式。以Auto CAD为图形支持软件,利用其图形处理功能构成零件图子集,继而按装配要求形成草图,通过接口程序将图形信息转换成数字信息,求交、消隐后自动生成所需的产品装配图。     

The Meaningful Involvement of Service Users in Social Work Education: Examples from Belgium and The Netherlands

This article links the development of service user involvement championed in the United Kingdom to two examples in Dutch-speaking qualifying social work programmes: one from Belgium and one from the Netherlands. In both projects, a longer lasting cooperation with more marginalised service users was established. The Belgium project highlights social work lecturers and service users living in poverty, working in tandem to deliver a module to social work and socio-educational care work students. The example from the Netherlands involves young people from a homeless shelter as peer-researchers, working together with social work students.

Both projects, one focusing on social work education and on social work research, highlight striking similarities in the positives and challenges of working with service users including how this challenges both groups preconceptions of the other, deepens learning but also creates greater potential for confrontations which need to be managed creatively. The article also identifies the pre-requisites for this to be effective including appropriate resourcing, training, facilitative skills and acknowledges that collaborations can be extremely fragile. However, such projects need further investment, experimentation and implementation on an international scale to share learning and promote creative approaches for the development and learning of social work students.     

Involving Service Users in Social Work Management Education: What Makes it Meaningful According to the ‘Experts’?

Course leaders have adopted a relatively cautious approach to involving service users and carers in Post-Qualifying (PQ) social work management education programmes in the UK, looking for opportunities in which it ‘makes sense’ for them to be included. Whilst there is, to a certain extent, the belief that involving service users and carers in PQ social work education is ‘a good thing’, it has proved challenging to implement. This research study sought to explore, through interviews with ‘experts’ in the field, why this process had proved so challenging. A term which emerged during the research was the importance of ‘meaningful involvement’. The research explored what ‘meaningful involvement’ might mean for managers, for academics and also for service users and carers; what it looks like and how might it take forward the understanding of and the preparation for PQ social work management education.     

Service Users,Social Work Education and Knowledge for Social Work Practice

This paper explores the implications of service user contributions to social work education in the light of historical critiques of disability research. The paper reflects on the authors' dual service user and academic perspectives as well as their dual disability studies and social work disciplinary affiliations. Referring back to early critiques of disability research, it argues that isolated user involvement in social work education can be problematic, particularly where that involvement is under the control of the academy. Drawing on feminist critiques of traditional social science, the authors present arguments for the collective involvement of service users in research and underpinning knowledge for social work as well as in social work education.     

中国证券业总产出和增加值测算研究

 金融机构总产出和增加值的测算是一项基础性的研究工作。与传统测算方法不同，本文借鉴经济合作和发展组织（OECD）提出的使用者成本法，把证券业视为生产性服务活动，并结合我国的实际情况，从服务的角度初步提出了我国证券业总产出和增加值的测算框架。并提出了未来研究改进的方向。     

基于贝叶斯图模型方法的投资组合决策

提出基于贝叶斯思想的图模型结构检测方法:首先给出精度矩阵新的参数化方法,且通过MCMC方法给出算法设计,最后将该图模型方法应用于中国证券市场,研究在牛市和熊市下证券市场六大板块之间的条件相关性.实证结果表明:牛市和熊市下的行业板块图结构存在显著差异,熊市似乎有着更强的相关性.     

Graphical Techniques for Selecting Explanatory Variables for Time Series Data

Bayesian model building techniques are developed for data with a strong time series structure and possibly exogenous explanatory variables that have strong explanatory and predictive power. The emphasis is on finding whether there are any explanatory variables that might be used for modelling if the data have a strong time series structure that should also be included. We use a time series model that is linear in past observations and that can capture both stochastic and deterministic trend, seasonality and serial correlation. We propose the plotting of absolute predictive error against predictive standard deviation. A series of such plots is utilized to determine which of several nested and non-nested models is optimal in terms of minimizing the dispersion of the predictive distribution and restricting predictive outliers. We apply the techniques to modelling monthly counts of fatal road crashes in Australia where economic, consumption and weather variables are available and we find that three such variables should be included in addition to the time series filter. The approach leads to graphical techniques to determine strengths of relationships between the dependent variable and covariates and to detect model inadequacy as well as determining useful numerical summaries.     

浅谈机房网络故障维护

网络机房是现代实验教学中必不可少的教学条件,维护好网络,才能保证实验教学的顺利进行。本文针对机房常见的网络故障,结合笔者工作环境,通过实践总结出几种常易出现的问题及解决方法。