Forming the optimal union of multiple databases

Many organizations, best illustrated by libraries, have access to hundreds of databases possessing varying degrees of complimentary and overlapping records. While users may receive positive marginal benefits from data duplications, all databases and their services cannot be supported because of resource limitations. This paper attempts to conceptualize the problem of database collection in an environment of multiple databases, with differential content and performance characteristics, diverse users, and limited resources. It defines the database collection problem as a constrained zero-one integer programming problem and solves for the optimal combination or union of databases. Several extensions are shown, where special conditions are imposed on the relationships between databases and/or their availability.     

The Buck Stops Where?

SUMMARY

University students-whether adult, distance learner, or traditional age-need access to university services and quick accurate answers to their questions beyond traditional “business” hours. Students' busy schedules and changing life patterns dictate that university services meet their needs. At DePaul University in Chicago, student focus groups repeatedly pointed to the need for one central place to get an answer or solve a problem. DePaul Central was created as an information and referral service to satisfy that student need, at the same capitalizing on the value of the librarian skill set.     

计算机端口和网络安全

该文介绍了一些与网络安全相关的计算机端口,并就如何通过这些端口的设置来提高计算机的网络安全性能进行了探讨,使网络运行环境更安全,更可靠。     

.NET Web services和FCS技术在煤矿安全监管中的应用

分析了现场总线技术(FCS)在分布式测控方面的优势,比较了.NETFrame和WindowsDNA框架下Web服务的适用范围。根据煤矿行业特点,提出了应用.NETWebservices和FCS技术构建煤矿安全监管系统的技术方案。     

ASCE Journal of Management in Engineering: Review of the years 1985–2002

This study considers the content of the papers published by ASCE’s Journal of Management in Engineering, which has witnessed a growth in number of papers and breadth of participation, particularly of international origin, during the 1985–2002 period. The content is analyzed in two main dimensions: the type of subject and its composing topics, and the type of contributors to the journal. The analysis shows the evolution of the engineering management discipline as represented in the journal. Over the years the discipline has been enriched by an increasing number of contributions on corporate strategies and programs, organizational change, and cultures issues, as well as a growing interest in project management topics, such as quality planning and evaluation of alternative project delivery systems. The number of papers by practitioners, initially the largest contributing group to the journal, has declined significantly over the years.     

Is time really important for research into contracting out public services in cities? Evidence for urban water management in Southern Spain

Local governments are responsible for the supply of important public services in cities. On many occasions the management of those services is externalized. There is extensive literature analyzing the explanations for the governance option taken by local governments, aiming to ascertain the reasons why the management of certain services is externalized. Recent research has highlighted the fact that time has not been contemplated by research dealing with explanatory factors in the decision to contract out municipal services. This is a key issue in order to identify the real reason behind policymakers’ decisions about the management of the services in cities. This paper tests the importance of taking into account time in the research into contracting out. This is undertaken by means of two methodological tests in the design of variables from a dataset containing 744 municipalities in Southern Spain. Using this empirical analysis as a basis, it is concluded that considering time contributes towards enhancing the specification of the model and that omitting this aspect could lead to misunderstanding the motivation behind such decisions.     

本地多点分布业务系统的体系结构及其关键技术

介绍宽带固定无线接入技术——LMDS的体系结构及其关键技术。     

基于Web Services的钻锣机监控系统的实施与应用

为加强对公司数量较多的钻机和锣机的集中监控管理,实施了利用JSP技术的基于Web services的钻锣机监控系统,采集了设备的工作状态和生产信息,实现了远程设备监控,并通过对加工过程参数和信息进行统计分析,提升了生产管理水平和设备稼动率.该系统可以同ERP和MES系统等系统互通集成,为企业打造透明高效的智能生产管理系统打下坚实的基础.     

中国联通公司电信发展近况

本文简介中国联通公司１９９８年发展建设电信业务总的指导思想，以及在ＧＳＭ、无线寻呼、长市话及中国环西太平洋海底光缆工程（ＣＷＰＣ）等方面所采取的措施及发展建设成就与现状。