Data tilting for time series

Summary. We develop a general methodology for tilting time series data. Attention is focused on a large class of regression problems, where errors are expressed through autoregressive processes. The class has a range of important applications and in the context of our work may be used to illustrate the application of tilting methods to interval estimation in regression, robust statistical inference and estimation subject to constraints. The method can be viewed as 'empirical likelihood with nuisance parameters'.     

神性、人性和理性--略论艺术形态与时代精神

艺术的本质在于其精神性,从艺术和时代精神的相互关系中去确立划分艺术形态的标准是符合艺术本质的.按照艺术所包含的精神内容的不同,艺术形态可分为神性艺术、人性艺术和理性艺术,以丰富的艺术史例可以说明其特征.     

Choice of the primary analysis in longitudinal clinical trials

Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd.     

现象学的问题如何发生--德里达对胡塞尔发生现象学的解读

德里达对胡塞尔的发生现象学有他自己的特殊理解,他研究了观念的历史,以及根据所形成的心理习惯构成的观念,当然,这也是观念对象构成的历史过程。发生是一个陌生的过程:在即将来临的历史中包含着一种中断。德里达描述了从某种确定的目的论返回到胡塞尔所新近确立的起源问题的运动结构。德里达研究稳定的结构与发生现象学之间的关系,在这个过程中,德里达提出了关于解构的基本问题。     

国家权力与城市空间:当代中国城市基层社会治理变革

确立和调整城市治理的空间策略是现代国家的重要任务。改革前中国的单位体制,使国家能够依靠单位实现“单元分隔”式的治理模式。改革以来,这种整齐划一的空间战略无法适应新的城市社会变迁。在城市社区管理体制改革中,出现了三种不同的国家空间战略,即“政党国家”,“行政国家”和“社会化国家”模式。当前城市社区改革的困难和复杂性体现了以上三种空间战略的对立和冲突。     

Creating a reference to a complex emergency situation using time series methods: war in Guinea-Bissau 1998-1999

Impacts of complex emergencies or relief interventions have often been evaluated by absolute mortality compared to international standardized mortality rates. A better evaluation would be to compare with local baseline mortality of the affected populations. A projection of population-based survival data into time of emergency or intervention based on information from before the emergency may create a local baseline reference. We find a log-transformed Gaussian time series model where standard errors of the estimated rates are included in the variance to have the best forecasting capacity. However, if time-at-risk during the forecasted period is known then forecasting might be done using a Poisson time series model with overdispersion. Whatever, the standard error of the estimated rates must be included in the variance of the model either in an additive form in a Gaussian model or in a multiplicative form by overdispersion in a Poisson model. Data on which the forecasting is based must be modelled carefully concerning not only calendar-time trends but also periods with excessive frequency of events (epidemics) and seasonal variations to eliminate residual autocorrelation and to make a proper reference for comparison, reflecting changes over time during the emergency. Hence, when modelled properly it is possible to predict a reference to an emergency-affected population based on local conditions. We predicted childhood mortality during the war in Guinea-Bissau 1998-1999. We found an increased mortality in the first half-year of the war and a mortality corresponding to the expected one in the last half-year of the war.     

从《老人》看凯瑟琳·安·波特的叙述艺术

凯瑟琳.安.波特的中篇小说《老人》在时间结构、叙述视角以及人物话语几个方面紧紧围绕米兰达对艾米姑妈的悲剧故事的了解过程这一主线展开。通过这些叙事策略进一步深化了小说的主题。     

中国始炼硫化汞时间新证

中国始炼硫化汞的时间问题,因其关涉到“人类第一次用自己的劳动得到了实质上与天然产物无二的成果”,而引起科技史家的极大关注,但因缺乏确凿资料,以至该问题一直悬而未决。事实上,此前学界认为道士升炼硫化汞的时间大略始于隋代的观点是值得商榷的。仅以《道藏》所载炼丹文献为例,即可粗举数例隋代以前与升炼硫化汞相关的资料。进一步的考证说明,中国古代道士早在南北朝或晋代甚至汉代,就已经能够用人工的方法升炼硫化汞了。     

数控机床功能的扩展

本文主要分析了HEIDENHAIN TNC 310数控铣床系统中圆弧铣削指令及螺纹铣削指令,对螺纹铣削功能进行延伸,扩展到圆弧三轴联动,并对螺纹铣削指令格式进行了修改,从而具有圆弧三轴联动铣削功能。     

基于经济时空的中国林业产业发展路径

经济时间和经济空间是研究产业变迁的两个重要维度,就林业产业时空特性而言,中国林业产业的发展面临着时空分离和时空压缩的困境。在经济全球化进程中,林业产业要适应现代科技变革和产业变迁,必须寻求新的发展路径:实现林业产业的时空转换,拓宽林业产业的市场时空;提高林业产业技术,促进林业产业的时空延伸;优化林业产业布局,提高林业产业的时空效益。