New estimates of trends in births by birth order in England and Wales

A greater understanding of past, present and future trends in fertility can be gained from analysing trends in birth order; that is whether a birth is a first, second, third or higher order birth. However, under current legislation, birth order information is not collected at registration for births outside marriage and birth order recorded within marriage is not the true birth order. This article presents revised and updated estimates of true birth order. It discusses the construction of the new estimates and presents analysis relating the births by true birth order to the population of women by parity on both a period (fertility in a particular year) and cohort (fertility of women born in a particular year) basis. The new true birth order figures are also compared to the previous set of estimates.     

The creation of 'consistent areas through time' (CATTs) in Scotland, 1981-2001

Small area analysis of sociodemographic change over time is often impeded by the changing configuration of census zones for each decennial UK census. Approaches for matching zone configurations exist, but these typically require population estimation techniques, which inevitably involve some error. Because of the postcode-based geographical zoning system used in Scottish censuses, it is possible to create a local-area geography which is consistent for recent censuses. Here we present a methodology used to create three sets of consistent areas through time (CATTs) that can be used for analysing comparable small area data output from the 1981, 1991 and 2001 Censuses.     

International migration to and from the United Kingdom, 1975-1999: consistency, change and implications for the labour market

This article presents some findings of a recent study carried out for the Home Office by the Migration Research Unit (MRU) in the Department of Geography at UCL. The study was concerned with patterns and trends in international migration to and from the United Kingdom since 1975, with a particular focus on those in employment, and drew on many sources. The statistics analysed here derive from the International Passenger Survey, including hitherto unpublished tables provided by the Office for National Statistics on migration of the employed by citizenship. They indicate remarkable consistency in some aspects of migration flows and major change in others.     

Estimates of the population by ethnic group for areas within England

This article describes, and provides some initial analysis of, the experimental population estimates by ethnic group for areas within England published by the Office for National Statistics (ONS) in January 2006. The article considers growth and the population structure of each of the ethnic groups identified in the 2001 Census; subnational patterns of change; population turnover; and measures of diversity and segregation, and also provides a comparison of the estimates and corresponding sample-based estimates from the Labour Force Survey.     

Families, groups and clusters of local and health authorities: revised for authorities in 1999

This is the second of two articles describing the revision of The ONS classification of local and health authorities of Great Britain to take account of area changes in the 1990's. It presents local authorities in Great Britain as at April 1999 in terms of Families, Groups and Clusters, based on 37 socio-economic and demographic variables from the 1991 Census. Health authorities are presented in terms of Families and Groups only, based on the same variables. The previous article (in Population Trends 98) presented, for each local and health authority, up to four other authorities to which it is 'most similar'.     

Performance analysis of multi-channel order statistics detector for range-spread target

The problem of two order statistics detection schemes for the detection of a spatially distributed target in white Gaussian noise are studied.When the number of strong scattering cells is known,we first show an optimal detector,which requires many processing channels.The structure of such optimal detector is complex.Therefore,a simpler quasi-optimal detector is then introduced.The quasi-optimal detector,called the strong scattering cells’ number dependent order statistics(SND-OS) detector,takes the form of an average of maximum strong scattering cells with a known number.If the number of strong scattering cells is unknown in real situation,the multi-channel order statistics(MC-OS) detector is used.In each channel,a various number of maximums scattered from target are averaged.Then,the false alarm probability analysis and thresholds sets for each channel are given,following the detection results presented by means of Monte Carlo simulation strategy based on simulated target model and three measured targets.In particular,the theoretical analysis and simulation results highlight that the MC-OS detector can efficiently detect range-spread targets in white Gaussian noise.     

二阶积-微分方程奇异边值问题解的存在性

讨论了一类二阶积 微分方程两点边值问题解的存在性。该问题以四阶微分方程两点边值问题为特例。首先在不假设非线性项单调,并允许其有奇性的情况下,利用上下解方法与Schauder不动点定理,获得了二阶Fredholm型积 微分方程两点边值问题解的存在性结果,然后把该结果应用于两端简单支撑的弹性梁的平衡状态模型—四阶微分方程边值问题。     

一种混合型多属性决策问题的TOPSIS方法

研究了精确数、区间数和模糊数指标相结合的混合多属性决策问题，提出了一种基于理想点的多属性决策模型，给出具体的决策方法和过程．各方案的排序是根据其到正理想解的相对贴近度大小进行的，从而为解决混合多属性决策问题提供了一条新的途径．     

6-3-3并联机构部分工作空间奇异性分析与仿真

建立了6自由度6-3-3并联机构的运动学逆解模型,给出了该机构奇异性判别矩阵。基于其运动学逆解和奇异性判别矩阵行列式数值是否为零,提出了对该机构部分工作空间进行奇异性仿真的方法并使用MATLAB语言开发了该机构部分工作空间奇异性仿真程序。最后给出了四个算例。研究为该并联机构的轨迹规划提供了技术基础。     

异小杆线虫离体繁殖技术研究

采用液体和固体两种培养方法繁殖异小杆线虫Heterorhabditis bacteriophora - 1（Hb—1）,测定和计算不同方法得到的线虫产量、质量和效率。试验结果表明,TSYS液体培养中接种单菌线虫是非单菌线虫产量的2．1倍,效率是其3．5倍。TSYS液体培养基培养线虫的效率明显高于PSYG液体培养基。TSYS固体培养线虫的产量和效率是其液体培养的3．7倍。液体培养和固体培养线虫均在第17d开始收获。20d后调查,固体培养的线虫致病力和存活率稍高于液体培养。图5,参13。     

引信战斗部系统的实弹打靶结果分析方法

实弹打靶中,引战系统的靶试结果分析是重要的一个方面,本文根据以往的工作经验,对引战系统的靶试结果分析的意义和方法作了综合概述,供引战系统总体人员、特别是刚参加此项工作的总体人员参考。     

AN ALGORITHM FOR THE DETERMINATION OF THE ECONOMIC ORDER QUANTITY IN A TWO-LEVEL SUPPLY CHAIN WITH TRANSPORTATION COSTS： COMPARISON OF DECENTRALIZED WITH CENTRALIZED DECISION

This paper considers a two-level supply chain consisting of one warehouse and one retailer. In this model we determine the optimal ordering policy according to inventory and transportation costs. We assume that the demand rate by the retailer is known. Shortages are allowed neither at the retailer nor at the warehouse. We study this model in two cases; decentralized and centralized. In the decentralized case the retailer and the warehouse independently minimize their own costs; while in the centralized case the warehouse and the retailer are considered as a whole firm. We propose an algorithm to find economic order quantifies for both the retailer and the warehouse which minimize the total system cost in the centralized case. The total system cost contains the holding and ordering costs at the retailer and the warehouse as well as the transportation cost from the warehouse to the retailer. The application of this model into the pharmaceutical downstream supply chain of a public hospital allows obtaining significant savings. By numerical examples, the costs are computed in MATLAB to compare the costs in the centralized case with decentralized one and to propose a saving-sharing mechanism through quantity discount.     

The decline of intensive intergenerational care of older people in Great Britain, 1985-1995

There are increasing concerns about the future availability of informal care for older people, particularly care by their children. This article explores past trends in the provision of informal care by children/children-in-law to their older parents/parents-in-law between 1985 and 1995 in Great Britain, using successive General Household Survey data. The article suggests that, during this period, there was a decline in co-resident intergenerational care and that this was associated with a decline in highly intensive intergenerational care. The article explores possible factors underlying these trends, in particular, demographic changes and changes in patterns of formal care for older people.     

The long shadow of childhood: associations between parental social class and own social class, educational attainment and timing of first birth; results from the ONS Longitudinal Study

In September 2004, linked data from the 2001 Census was made available in the Office for National Statistics (ONS) Longitudinal Study (a 1 per cent sample of the population of England and Wales). The study now includes information from four censuses on sample members and the people they lived with. The availability of this new information, the length of follow-up and other features of the study (such as records of births and deaths to sample members) provide new opportunities for analysing change--both over the life course, between time periods, and between generations. This article illustrates the potential for analysis of continuity and change with new results on intergenerational social mobility, and on parental social class and age at first birth.     

Intergenerational replacement and migration in the countries and regions of the United Kingdom, 1971-2009

This article uses a recently proposed measure, the overall replacement ratio or ORR, to assess the extent to which migration alters intergenerational replacement within the United Kingdom. The UK as a whole can be seen to experience 'replacement migration' as immigration compensates for fertility below the replacement level. However, the article shows that the impact of migration differs radically in the different regions of the country. South East England experiences very substantial immigration from both the rest of the UK and overseas, far more than is needed for intergenerational replacement, whereas most of the rest of the UK sees little or no net immigration and the ORR remains below the replacement level.     

Changing economic and social roles: the experience of four cohorts of mid-life individuals in Britain, 1985-2000

Men and women in Great Britain are increasingly involved in a variety of economic and social roles, particularly during their mid-life period. This article examines the changes in role occupancy across four birth cohorts passing throughout mid-life over the period 1985-2000. Data from the General Household Survey is used to investigate the occupancy of four key roles: 'partner', 'parent', 'carer' and 'paid worker', analyzing separate and multiple role occupancies and level of commitment to a particular role. The implications of the findings for health and employment policies is also discussed.     

特殊一维背包问题的降维替换算法研究

对问题单约束0-1线性整数规划问题(0-1ILP,背包问题)的特性进行了分析,设计了问题求解的算法--降维替换算法(线性规划求解与特殊启发式相结合的方法).     

《系统辩证学学报》2003-2005年载文、作者和引文的统计分析与评价

应用文献计量学的方法，对《系统辩证学学报》2003--2005年的栽文、作者和引文情况进行了定量分析，重点讨论了栽文量和基金项目论文比例；作者的地区分布、合著率和合作度以及多产作者的分布情况；引文数量、语种和高频被引期刊、被引作者以及自引情况等方面的内容，以便使作者、读者和编者对本刊有更深入的了解。同时希望经过系统科学领域同仁的共同努力，使它在更名为《系统科学学报》后有更好的发展与提高。     

Planning of dynamically feasible trajectories for translational, planar, and underconstrained cable-driven robots

Extensively studied since the early nineties, cable-driven robots have attracted the growing interest of the industrial and scientific community due to their desirable and peculiar attributes. In particular, underconstrained and planar cable robots can find application in several fields, and specif- ically, in the packaging industry. The planning of dynamically feasible trajectories （i.e., trajectories along which cable slackness and excessive tensions are avoided） is particularly challenging when dealing with such a topology of cable robots, which rely on gravity to maintain their cables in tension. This paper, after stressing the current relevance of cable robots, presents an extension and a generalization of a model-based method developed to translate typical cable tension bilateral bounds into intuitive limits on the velocity and acceleration of the robot end effector along a prescribed path. Such a new formulation of the method is based on a parametric expression of cable tensions. The computed kine- matic limits can then be incorporated into any trajectory planning algorithm. The method is developed with reference to a hybrid multi-body cable robot topology which can be functionally advantageous but worsen the problem of keeping feasible tensions in the cables both in static and dynamic conditions. The definition of statically feasible workspace is also introduced to identify the positions where static equilibrium can be maintained with feasible tensions. Finally, some aspects related to the practical implementation of the method are discussed.     

人口、资源、环境与经济协调发展的多目标集成模型

人口 (population)、资源 (resource)、环境 (environment)和经济 (economy)是区域可持续发展的关键要素 ,组成了一个动态开放复杂系统 ,简称为PREE系统。在PREE协调发展研究的定量分析中 ,需要解决PREE复杂系统的整体性问题。提出了一种三层次模型体系结构 ;建立了基于目标规划的PREE系统多目标综合集成模型。该模型可较好地反映各子系统协调发展的制衡关系 ,并完整地体现了PREE系统的整体性特征 ,为开展用于预测和规划的区域可持续发展的定量研究提供了技术基础。