Modelling of connected processes

The problem of comparing, contrasting and combining information from different sets of data is an enduring one in many practical applications of statistics. A specific problem of combining information from different sources arose in integrating information from three different sets of data generated by three different sampling campaigns at the input stage as well as at the output stage of a grey-water treatment process. For each stage, a common process trend function needs to be estimated to describe the input and output material process behaviours. Once the common input and output process models are established, it is required to estimate the efficiency of the grey-water treatment method. A synthesized tool for modelling different sets of process data is created by assembling and organizing a number of existing techniques: (i) a mixed model of fixed and random effects, extended to allow for a nonlinear fixed effect, (ii) variogram modelling, a geostatistical technique, (iii) a weighted least squares regression embedded in an iterative maximum-likelihood technique to handle linear/nonlinear fixed and random effects and (iv) a formulation of a transfer-function model for the input and output processes together with a corresponding nonlinear maximum-likelihood method for estimation of a transfer function. The synthesized tool is demonstrated, in a new case study, to contrast and combine information from connected process models and to determine the change in one quality characteristic, namely pH, of the input and output materials of a grey-water filtering process.     

Markov chain Monte Carlo methods for high dimensional inversion in remote sensing

Summary.  We discuss the inversion of the gas profiles (ozone, NO₃, NO₂, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the 'Global ozone monitoring of occultation of stars' instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for a more comprehensive statistical inversion are presented. A direct inversion leads to a non-linear model with hundreds of parameters to be estimated. The problem is solved with an adaptive single-step Markov chain Monte Carlo algorithm. Another approach is to divide the problem into several non-linear smaller dimensional problems, to run parallel adaptive Markov chain Monte Carlo chains for them and to solve the gas profiles in repetitive linear steps. The effect of grid size is discussed, and we present how the prior regularization takes the grid size into account in a way that effectively leads to a grid-independent inversion.     

Empirical nonparametric control charts for high-quality processes

For attribute data with (very) small failure rates often control charts are used which decide whether to stop or to continue each time r failures have occurred, for some r?1. Because of the small probabilities involved, such charts are very sensitive to estimation effects. This is true in particular if the underlying failure rate varies and hence the distributions involved are not geometric. Such a situation calls for a nonparametric approach, but this may require far more Phase I observations than are typically available in practice. In the present paper it is shown how this obstacle can be effectively overcome by looking not at the sum but rather at the maximum of each group of size r.     

Accurate ARL computation for EWMA-S<Superscript>2</Superscript> control charts

Originally, the exponentially weighted moving average (EWMA) control chart was developed for detecting changes in the process mean. The average run length (ARL) became the most popular performance measure for schemes with this objective. When monitoring the mean of independent and normally distributed observations the ARL can be determined with high precision. Nowadays, EWMA control charts are also used for monitoring the variance. Charts based on the sample variance S² are an appropriate choice. The usage of ARL evaluation techniques known from mean monitoring charts, however, is difficult. The most accurate method—solving a Fredholm integral equation with the Nyström method—fails due to an improper kernel in the case of chi-squared distributions. Here, we exploit the collocation method and the product Nyström method. These methods are compared to Markov chain based approaches. We see that collocation leads to higher accuracy than currently established methods.     

天津市高职示范校教学质量监控体系建设现状探析

基于天津市高职示范院校,从教学质量监控中的评价主体、操作方法、评价范围、评价结果反馈等多个方面进行阐述;查找当前存在的问题并提出改进建议。     

元认知理论、作用及其能力的培养

元认知是对认知的认知,在教育、语言领域中有着广泛、深刻的影响.本文概述了元认知理论,它包括三个组成部分:元认知知识、元认知体验、元认知监控.并讨论了元认知在外语自主学习中的作用,及如何培养元认知能力来促进学习者的自主学习能力,有效提高学习效率,以达到教育要求.     

基于医疗质量实时监控系统的运行病历书写质量研究

目的:研究医疗质量实时监控系统是否可以提高运行病历的书写质量?方法:对实时监控前后共四年的运行病历书写质量进行回顾性分析,监控前共抽查960份运行病历,监控后检查24 255份运行病历,从运行病历书写的及时性?完整性?内涵质量三方面进行汇总分析?结果:监控前组和监控组比较,及时性达标率由79.4%提升到85.2%(P < 0.001),完整性达标率由94.9%提升到98.2%(P < 0.001),内涵质量达标率由91.8%提升到93.6%(P = 0.114);监控后第二年(2013年)发现运行病历书写及时性?完整性?内涵质量不达标情况分别集中在危重患者病程记录不及时?入院录不完整?日常病程记录内涵质量不高等方面;运行病历书写质量受书写人员的性别?学历?职称?科室因素影响?结论:医疗质量实时监控系统的应用是提高运行病历书写及时性?完整性的有效方法,但对提高运行病历书写的内涵质量效果不明显;女性?高职称?高学历?非手术科室的医务人员运行病历书写的质量较高?     

电动钻机步进式平移结构应力监测及强度分析

步进式平移可实现钻机前后左右整体移动,具有移动快速、操作便捷的特点,在丛式井组中应用广泛。针对 在役电动钻机加装步进式平移装置后,能否满足满立根情况下钻机整体平移的问题,开展了钻机平移结构应力监测试 验研究,以川庆钻探公司一台ZJ50DBS 钻机为研究对象,通过有限元分析找出钻机平移时结构受力较大部位的应力 监测点,在钻机无立根工况下进行钻机平移应力监测,再在试验数据分析结果基础上,以强度校核结果为目标值,对钻 机结构有限元模型进行修正,最后在修正模型上施加满立根载荷进行钻机整体平移受力分析。分析结果表明,该钻机 在底座安装步进式平移装置后,能够满足在满立根情况下的安全平移。     

以目标管理为核心完善高校教学质量监控体系

教学工作是学校经常性的中心工作,教学质量是教学工作永恒的主题。科学、规范、完善的教学质量监控体系,是以教学质量监控为重点,对教学过程和教学管理实行全面系统监控,是学校在不断扩大办学自主权的形势下,加强学校内部自我约束、增强自我发展能力的主要保证之一。如何将目标管理的理论和方法完全引入到教学管理中,使教学评价发挥更大的激励作用,是教学质量管理和当前广泛开展教学评价工作需要研究的重要课题。     

基于DirectShow的MPEG-4监控系统的设计与实现

介绍了DirectShow技术,并用该技术实现了一个基于MPEG-4的网络视频监控系统,包括多媒体数据的捕捉、解码、回放、定位等功能。基于DirectShow框架的构建方式极大地简化了复杂的多媒体程序的开发,同时实现了视频监控系统对实时性和清晰度可调的要求,为MPEG-4应用提供了一套完整的解决方案。