Making sense of absolute measurement: James Clerk Maxwell,William Thomson,Fleeming Jenkin,and the invention of the dimensional formula

During the 1860s, the Committee on Electrical Standards convened by the British Association for the Advancement of Science (BAAS) attempted to articulate, refine, and realize a system of absolute electrical measurement. I describe how this context led to the invention of the dimensional formula by James Clerk Maxwell and subsequently shaped its interpretation, in particular through the attempts of William Thomson and Fleeming Jenkin to make absolute electrical measurement intelligible to telegraph engineers. I identify unit conversion as the canonical purpose for dimensional formulae during the remainder of the nineteenth century and go on to explain how an operational interpretation was developed by the French physicist Gabriel Lippmann. The focus on the dimensional formula reveals how various conceptual, theoretical, and material aspects of absolute electrical measurement were taken up or resisted in experimental physics, telegraphic engineering, and electrical practice more broadly, which leads to the conclusion that the integration of electrical theory and telegraphic practice was far harder to achieve and maintain than historians have previously thought. This ultimately left a confusing legacy of dimensional concepts and practices in physics.     

科技档案应用开发研究

科技档案是开展各种科技活动后的技术总结,包括项目申请书、项目总结报告、科技报告等,是科技工作者智慧的结晶,也是开展科技创新的重要参考,科技档案的开发利用,既有利于挖掘科技档案中沉淀的知识,为科技发展和经济建设服务,也是对开展各种科技活动绩效的反映.该文从科技档案的利用价值出发,说明科技档案应用开发必须首先建立信息化的管理系统,并采用大数据技术和数据开放获取技术,以充分发挥科技档案对科技创新的参考和支撑作用.     

胜东社区供热系统的节能技术改造

文章结合实际,介绍了胜利油田胜东社区供热系统节能技术改造方案、系统技术特点、主要经济技术指标以及系统改造后的效果评价等。实践证明,该系统节能技术改造效果良好。     

浅议电力企业降低线损率的措施

供电企业是为电力企业获取经济效益最直接的窗口。如何降低线损率,提高供电企业的经济效益,这对处在改革和发展过程中的电力企业是一个不小的挑战。降低线损率是提高电力企业经济效益的一个重要方面。文章通过对线损概念的提出、解释,分析了当前电网线损产生的主要原因,针对这些原因指出了降低线损率的管理措施和技术措施,最后提出合理降低线损率对节能减排的促进作用。     

Big Data: Unleashing information

At present,it is projected that about 4 zettabytes(or 10**21 bytes)of digital data are being generated per year by everything from underground physics experiments to retail transactions to security cameras to global positioning systems.In the U.S.,major research programs are being funded to deal with big data in all five sectors(i.e.,services,manufacturing,construction,agriculture and mining)of the economy.Big Data is a term applied to data sets whose size is beyond the ability of available tools to undertake their acquisition,access,analytics and/or application in a reasonable amount of time.Whereas Tien(2003)forewarned about the data rich,information poor(DRIP)problems that have been pervasive since the advent of large-scale data collections or warehouses,the DRIP conundrum has been somewhat mitigated by the Big Data approach which has unleashed information in a manner that can support informed-yet,not necessarily defensible or valid-decisions or choices.Thus,by somewhat overcoming data quality issues with data quantity,data access restrictions with on-demand cloud computing,causative analysis with correlative data analytics,and model-driven with evidence-driven applications,appropriate actions can be undertaken with the obtained information.New acquisition,access,analytics and application technologies are being developed to further Big Data as it is being employed to help resolve the 14 grand challenges(identified by the National Academy of Engineering in 2008),underpin the 10 breakthrough technologies(compiled by the Massachusetts Institute of Technology in 2013)and support the Third Industrial Revolution of mass customization.     

关于宇宙不会“热寂”的一种论证

本文利用宇宙大爆炸模型来说明宇宙不会“热寂”。     

Integrating time-series and end-use methods to forecast electricity sales

Two types of forecasting methods have been receiving increasing attention by electric utility forecasters. The first type, called end-use forecasting, is recognized as an approach which is well suited for forecasting during periods characterized by technological change. The method is straightforward. The stock levels of energy-consuming equipment are forecast, as well as the energy consumption characteristics of the equipment. The final forecast is the product of the stock and usage characteristics. This approach is well suited to forecasting long time periods when technological change, equipment depletion and replacement, and other structural changes are evident. For time periods of shorter duration, these factors are static and variations are more likely to result from shocks to the environment. The shocks influence the usage of the equipment. A second forecasting approach using time-series analysis has been demonstrated to be superior for these applications. This paper discusses the integration of the two methods into a unified system. The result is a time-series model whose parameter effects become dynamic in character. An example of the models being used at the Georgia Power Company is presented. It is demonstrated that a time-series model which incorporates end-use stock and usage information is superior—even in short-term forecasting situations—to a similar time-series model which excludes the information.     

State-space modelling of residential,commercial and peak demands

The potential use of state-space modelling is evaluated through comparison with the existing multivariate ARMA models currently in use at Georgia Power Company for forecasting its residential sales, commercial sales and peak demand.     

半导体变流技术的应用

本文通过实例论述半导体变流技术在工业电气化及自动化中的应用。     

电信数据仓库体系结构的研究

近年来,随着企业信息化的建设及电信业务的不断发展,电信企业建立了众多的信息系统,以帮助企业进行内外部业务的处理和管理工作.然而,随着信息系统的增加,信息系统产生了海量的业务数据,并且这些各自孤立工作的信息系统存在数据统计口径不一致、数据质量较差、难以共享等缺点.为此提出了基于电信数据仓库的体系结构,从而解决了数据统计口径不一致、数据难以共享等缺点,并探讨了数据仓库系统在电信针对性营销上的应用.