Flows and Cohesion: Balancing Capabilities Across an Expanded Union1

Until recently the flow of skilled workers to established centres from more peripheral regions was seen as a ‘brain drain’, implying a one‐way and permanent loss of skilled labour. However, increasing mobility and connectivity permits more complex traffic between more and less advanced locations. With the emergence of a global economy dependent on flows of material and intellectual capital, the notion of ‘brain circulation’ has gained prominence. Understanding the potential benefits of migration to both donor and recipient economies must move beyond financial remittance to social remittance. As connectivity increases, both become capacity‐building resources. This article discusses the impact of a combination of greater physical mobility and electronic connectivity on the dual objectives of social cohesion and technical leadership being pursued through the policies of the European Commission.     

现代化进程中古城风貌的保护与延伸

在现代化进程中古城风貌保护与延伸的理论与对策应是社会学学者所关注的一个问题。古城应在动态中进行“城市性格”保护和延伸,在宏观上分异城市功能,在微观上注重“修旧如旧”和“点、线、面”的三位一体,城市社区的建设问题可以在保护和延伸中协调解决。     

大宗物资集中采购的调运计划研究

大宗物资调运问题是一个受多因素影响的复杂问题,一般来讲,其调运数量大、地域跨度大、时间紧。如何协调供需以及运输能力,保证物资采购部门的经济利益是本文所要研究的问题。本文首先给出了大宗物资集中采购的调运模式,然后针对采购部门在大宗物资调运过程中遇到的困难,为采购部门提出了以获取数量折扣、准时采购、降低库存成本和协调运输能力为准则的调运计划模型。数值计算表明应用本文所建模型编制调运计划能够达到降低采购费用、协调运输能力的目的,为大宗物资调运计划的编制提供了一种较为有效的方法。     

回收物流库存控制研究

本文探讨了包含回收品的库存系统。回收物流库存中既有一般生产过程的新产品,也有经再制造的回收品,使其最优库存策略非常复杂,论文推导出不同控制方式下的EOQ模型,以确定最优生产和再制造批量。此外,还对求得的最优批量进行适当的调整,以确保在循环周期中的定货次数为整数。该模型形式、结构简单易于在实践中应用。     

理想气体微观状态数的计算及其统计性质的研究

本文借助自由粒子的量子能态分布理论,利用3n维空间球体模型,实现了对理想气体（N,V,E）系统微态数的计算,在此基础上,给出了理想气体热力学量的统计结果。     

西汉人口数量变化考论

西汉人口数量变化大体可分为三个阶段:汉初至武帝前期(前202年—前130年),西汉人口由1300多万增长到3400万左右,是人口的快速增长时期;武帝中后期(前129年—前87年),由于战争等原因,造成大量人口非正常死亡,全国人口进入增长停滞期,甚至显著下降,武帝末年人口减少到2800多万;昭帝至平帝元始二年(前86年—公元2年),社会较为安定,西汉人口又进入增长时期,并达到5900多万的高峰。但此数字,并不是西汉末年全部实际存在的人口数,而仅仅是以郡国为基础列入政府版籍的“编户齐民”。实际人口数应加上:隐匿人口,宗室、列侯及奴婢人口,西域都护管辖地区的人口及以属国方式管辖的少数民族人口。西汉末年人口总数可达6400万。     

《空中之鸟》与雕塑的语言

《空中之鸟》以纯粹的形式体现了雕塑的三种语言:体感、量感、质感。雕塑是体感、量感、质感的艺术,这句话用抽象的术语表述出来,也就是,雕塑是"存在"的艺术。中国书法的基本精神是"变化",雕塑艺术的基本精神是"存在"。     

胀接对管板强度的加强效应

由于胀接使列管与管板紧密连接，管壁厚度的部分或全部可以考虑在管桥 宽度中.本文通过数值计算分析了胀接对管板强度的加强效应.     

Bootstrap confidence regions computed from autoregressions of arbitrary order

Given a linear time series, e.g. an autoregression of infinite order, we may construct a finite order approximation and use that as the basis for confidence regions. The sieve or autoregressive bootstrap, as this method is often called, is generally seen as a competitor with the better-understood block bootstrap approach. However, in the present paper we argue that, for linear time series, the sieve bootstrap has significantly better performance than blocking methods and offers a wider range of opportunities. In particular, since it does not corrupt second-order properties then it may be used in a double-bootstrap form, with the second bootstrap application being employed to calibrate a basic percentile method confidence interval. This approach confers second-order accuracy without the need to estimate variance. That offers substantial benefits, since variances of statistics based on time series can be difficult to estimate reliably, and—partly because of the relatively small amount of information contained in a dependent process—are notorious for causing problems when used to Studentize. Other advantages of the sieve bootstrap include considerably greater robustness against variations in the choice of the tuning parameter, here equal to the autoregressive order, and the fact that, in contradistinction to the case of the block bootstrap, the percentile t version of the sieve bootstrap may be based on the 'raw' estimator of standard error. In the process of establishing these properties we show that the sieve bootstrap is second order correct.     

话语有效的基本原则

话语是人们口头、书面语言活动的结果，话语是否有效与信息编码的要求有关，也与编码者有关。从编码的角度上说，语言形式所表现的意义和内容都有合质的要求，而且要适量，适量不等于简化语符，也不等于多多益善。从编码者的角度上说，善预测与善选择与否是衡量语言把握能力的重要因素。