Federated searching and usability testing: Building the perfect beast

With the ubiquity of federated search tools as viable solutions for students and researchers to search across external sources and internal repositories, users have become more sophisticated in their application of this technology. With the goal of optimizing the user experience of its newly introduced federated search offering, Endeavor Information Systems employed usability testing to gain insights into the critical requirements of librarians and information professionals for this solution. The results of this analysis, conducted in concert with market research and customer focus groups, and their relevance to Endeavor's federated search technology are the focus of this article.     

A simple approximation for the doubly noncentral t-distribution

A simple approximation for the doubly noncentral t-distribution, based upon the Fieller-Geary Theorem (1930) and approximate normality of the square root of the noncentral chi-square variable observed by Patnaik (1949), is developed, This approximation and an Edgeworth series expansion associated with it are evaluated. The simple approximation is seen to be reasonably accurate for most practical purposes.     

美国扩军备战的鼓吹者——伦纳德·伍德

伦纳德·伍德认为：美国必须为未来战争做好准备，实行国民经济总动员，建立公民军队、平民军事教育体系和预备役军官。他在担任总参谋长期间采取了一系列的措施：提高总参谋部的效率，改革后勤，改组国民警卫队，改革军队编制，开展“普拉茨堡运动”，颁布1916年《国防法》和《扩军法》，为美国参加第一次世界大战做好了准备。     

Could Removing Arsenic from Tobacco Smoke Significantly Reduce Smoker Risks of Lung Cancer?

If a specific biological mechanism could be determined by which a carcinogen increases lung cancer risk, how might this knowledge be used to improve risk assessment? To explore this issue, we assume (perhaps incorrectly) that arsenic in cigarette smoke increases lung cancer risk by hypermethylating the promoter region of gene p16INK4a, leading to a more rapid entry of altered (initiated) cells into a clonal expansion phase. The potential impact on lung cancer of removing arsenic is then quantified using a three‐stage version of a multistage clonal expansion (MSCE) model. This refines the usual two‐stage clonal expansion (TSCE) model of carcinogenesis by resolving its intermediate or “initiated” cell compartment into two subcompartments, representing experimentally observed “patch” and “field” cells. This refinement allows p16 methylation effects to be represented as speeding transitions of cells from the patch state to the clonally expanding field state. Given these assumptions, removing arsenic might greatly reduce the number of nonsmall cell lung cancer cells (NSCLCs) produced in smokers, by up to two‐thirds, depending on the fraction (between 0 and 1) of the smoking‐induced increase in the patch‐to‐field transition rate prevented if arsenic were removed. At present, this fraction is unknown (and could be as low as zero), but the possibility that it could be high (close to 1) cannot be ruled out without further data.     

Information matrix for a mixture of two inverse gaussian distributions

In this paper, Fisher information matrix about the five parameters ρ, μ_:1, μ², λ¹and λ²of a mixture of two Inverse Gaussian density functions is obtained. The Leguerre-Gauss quadrature formula is used to evaluate the essential integral on which the twenty five elements of the information matrix are based. Results involving the computation of the information about p are compared with those involving both the power series expansion and Simpson's method of integration. Laguerre-Gauss quadra-ture was found to lead to good approximations as compared with other methods. It was therefore chosen for the computations of the elements of the information matrix.     

聚酯聚合反应分层温度控制系统

介绍了聚合釜聚酯聚合反应温度过程控制系统及其设计方法。控制系统以高性能单片机系统为直控机（DDC）,PC机为上位机（MIS）,直控机负责聚合釜釜温及夹套温度采集、分析、控制,并将参数送上位机。上位机负责控制过程的时间及温度值设定、温度监测、工作过程监控。     

生态环境效应视角提升产业竞争力路径选择

针对废旧电子产品污染环境问题,采用实证的方法,分析了电子产品的污染状况和影响因素,提出要营造投资环境,引进产业链高端技术,建立激励机制,引导企业减少污染等措施。研究结果对电子信息产业的竞争力提升有指导作用。     

合并高校电子阅览室开放式管理系统的开发与应用

文章简要介绍了合并高校图书馆电子阅览室管理系统的设计原理、流程及方法,实现了对多校区电子阅览室集中管理,不仅方便读者上机,计费准确,同时减轻了管理人员劳动强度,提高管理层次.     

环境殖民主义批判

环境殖民主义是资本主义殖民本性在环境领域的体现和拓展。为了维持资本主义生产生活方式,发达国家不仅掠夺发展中国家的能源资源与原料燃料等,还通过多种方式把有毒有害废弃物和垃圾输往广大发展中国家。环境殖民根源于资本的求利本性和全球扩张,资本主义生态理性与经济理性存在不可调和的矛盾。我国应以科学的态度对待环境殖民主义。     

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.