The future of international construction: some results of 1992-1999 surveys

Since 1992, eight annual opinion surveys of international construction activity have been conducted. The annual survey questionnaires are sent to key individuals concerned with construction activity in their own countries and internationally. The principal interest of the ECERU opinion survey is the predicted future development of construction activity worldwide. The survey is concerned with construction and economic development in general, and with specific questions relating to the global construction market over the next 25 years, 5 years and 12 months. This paper analyses and assesses some of the survey results, identifying future construction market trends at the regional, national and metropolitan level. The principal findings suggest that, at the regional level, the survey respondents generally share the survey's optimism about Asia and pessimism about Western Europe and Africa. However they disagree with the survey's pessimism about North America, East and Central Europe and South America. At the national and metropolitan level China and cities within China are considered noteworthy. The paper concludes that the Asian construction market is still at the focus of attention worldwide despite the problems following the Asian financial crisis. Depuis 1992, on a organisé huit sondages d'opinion annuels sur les activités du secteur de la construction dans le monde. Les questionnaires ont été envoyés à des personnalités concernées par la construction dans leur pays et au niveau international. Le principal intérêt de ces sondages conduits par l'ECERU est d'obtenir des informations prévisionnelles sur le développement de la construction dans le monde. Les sondages portent sur la construction et le développement économique en général; des questions spécifiques ont trait au marché global de la construction à trois échéances différentes: 25 ans, 5 ans et 12 mois. La présente communication analyse et évalue certains des résultats de ces sondages et dégage les tendances commerciales futures du secteur de la construction aux niveaux régional, national et métropolitain. Les principaux résultats laissent à penser qu'au niveau régional les personnes interrogées qui ont rempli les questionnaires partagent, d'une manière générale, l'optimisme de l'ECERU en ce qui concerne l'Asie et son pessimisme pour ce qui est de l'Europe occidentale et de l'Afrique. En revanche, elles n'adhèrent pas au pessimisme de l'ECERU quant à l'Amérique du nord, l'Europe centrale et de l'est et l'Amérique du sud. Aux niveaux national et métropolitain, la Chine et les grandes villes chinoises sont dignes d'intérêt. Les auteurs concluent qu'en Asie le marché de la construction reste au centre de l'attention en dépit des problèmes qui ont découlé de la crise financière en Asie.     

An assessment of the applicability of partnering in the Turkish construction sector

There are problems associated with the Turkish construction sector; some of these problems are implications of Government policy, restrictions imposed on public construction projects, bureaucratic procedures, contractual clauses incorporating unfair risk sharing and inadequacies in control mechanisms. Some problems can be attributed to inadequate technological knowhow, and/or lack of education and training incen1 tives in new technologies and management approaches. This paper presents findings from research that was aimed at investigating the applicability of partnering in the Turkish construction sector as an alternative approach in seeking solutions to some of the problems within this industry. The findings suggest that the partnering approach could help reduce some of the problems associated with the Turkish construction sector, although the implementation of this approach is likely to face complications, mainly in terms of cultural change requirements and the bureaucracies associated especially with the public construction process. The findings also suggest that if partnering were to be considered for Turkey, the private construction sector would offer more flexibility in the implementation of this approach, rather than reliance on the Government for the introduction of partnering into Turkey.     

The divergence in aggregate and activity estimates of US construction productivity

Discrepancies exist between aggregate and activity productivity measurements in the US construction industry. Multiple studies using aggregate industry measures suggest that construction productivity has declined over the long term. A longstanding problem with the aggregate measures concerns the difficulty of controlling for inflation so as to accurately measure real output. As an alternative, average activity productivity, measured by individual work activities, indicates that construction productivity has increased over the same time period. Activity measurement data have been collected for 200 construction activities over a 22-year time period from commercial estimation manuals used by contractors and owners to estimate the cost and time requirements for construction. This paper examines the discrepancies between aggregate and activity measurements and suggests possible reasons for their existence.     

高速切削机床关键技术研究与分析

高速切削技术是一门先进的工艺制造技术,在各类机械产品的制造加工中具有独特优势。高速切削机床作为高速切削技术的重要组成部分,呈现出超高速化、高精密度的发展趋势,是当今机械装备研究与开发的重点。系统总结了国内外高速机床的最新发展动态与趋势;详细分析了高速机床中的高速主轴系统、高速进给驱动系统、高性能控制系统和刀具系统等关键技术,为机床的技术改进和结构创新提供了专业建议与设计思路。借助对关键技术的研究,能够有效提高机床的加工速度和加工质量,为现代机械制造业的发展奠定良好的基础。     

扭矩传感器的现状与发展趋势

综述了国内外研制的多种扭矩传感器,并介绍了发展趋势。     

Evaluation of Cryogenic Flow Meters: An Example in Non-Standard Experimental Design and Analysis

A number of difficult problems in experimental design and analysis were afforded by an experiment to evaluate the precision and accuracy of a new facility for calibrating cryogenic flow meters. Time order was an important variable, but could not be economically randomized. The design space was not rectangular and two important variables were intrinsically highly correlated. The resulting data had outliers, cycles, unexpected shifts and other dilticultics. This report chronicals the evolution of the design of the experiments and the analysis of the results.     

锂离子电池最新动态和进展——第九届国际锂电池会议简介

介绍了第九届国际锂电池会的情况,在对会议的一般情况回顾后,对锂电池的最新进展和动向以及锂电池的相关材料的研究情况作了较详细介绍。     

A survey of teenager unnatural deaths in northern Sweden 1981-2000

OBJECTIVE: To survey unnatural deaths among teenagers in northern Sweden and to suggest preventive measures. SETTING: The four northernmost counties (908,000 inhabitants, 1991), forming 55% of the area of Sweden. MATERIAL AND METHODS: All unnatural teenager deaths from 1981 through 2000 were identified in the databases of the Department of Forensic Medicine in Umea, National Board of Forensic Medicine. Police reports and autopsy findings were always studied, social and hospital records if present. RESULTS: Three hundred and fifty-five deaths were found, of which 267 (75%) were males and 88 (25%) females. Ninety out of 327 (28%) tested positive for alcohol. Two hundred and forty-eight (70%) were unintentional and 102 (30%) were intentional deaths, and five (1%) were categorized as undetermined manner of death. Unintentional deaths decreased while the incidence of intentional deaths remained unaffected by time. CONCLUSIONS: Injury-reducing measures have been effective concerning unintentional deaths and the fall in young licensed drivers due to the economical recess have probably also contributed to the decrease. However, there were no signs of decreasing numbers of suicides during the study period, which calls for resources to be allocated to suicide prevention.