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关键词： 特色数据库   系统建设   评价指标  

摘要： 本文主要结合高校图书馆特色数据库的建设情况,并基于数据库评价的意义和原则分析,重点对特色数据库系统建设的评价指标进行了分析,以期促进特色数据库的发展和完善。

关键词： 数字图书馆   藏书总量   资源共享   河嘴   煤矿机电   办公网络   维修知识   数据库系统   电钳   煤炭技术  

摘要： "利用电脑就可以免费看到想看的书籍,获取需要的知识,真不错。"1月5日,川煤集团达竹公司小河嘴煤矿机电队员工钱依顺从该集团数字图书馆查阅到自己所需的电钳维修知识后,高兴地说。为适应当前员工的阅读习惯,川煤集团建立了网上数字图书馆,员工可通过集团办公网络实现网上阅读。该数字图书馆利用数据库系统,实现大规模集成技术信息数据资源,为集团员工提供各类煤炭技术信息和管理信息,开发了资源共享。

关键词： 病虫草害   智能移动终端   病虫害   防治方法   Android   知识库系统   数据库系统  

摘要： 一、引言 农业的发展不仅需要采取先进的农业技术措施,更需要通过信息化的手段拓宽农业新知识、新技术的传播和推广,使之有效应用于农业发展各个领域,响应当前农业信息化的趋势.随着无线网络的不断发展,手机、平板电脑等智能移动终端的迅速普及,在户外上网检索信息的需求已经非常普遍,越来越多的人深刻体会到移动互联网很大改变了人们的生活方式,甚至对人们的工作方式也产生了巨大的影响.

关键词： 数据库系统   可视化   地理信息工程  

摘要： 基于轻量级空间数据库Spatialite在当前的移动端地理信息应用等领域中正发挥着越来越大的作用。采用空间数据库的管理思路和开发方法,分析了Spatialite空间数据库的数据组织与存储机制,阐述了数据库开发的方法和技术路线,通过在.Net环境下进行的空间数据库管理系统的可视化应用开发实践,为轻量级的空间数据库应用提供了一个良好的解决思路。

关键词： firebird数据库   区域站资料   数据整理   数据质量控制  

摘要： 区域站历史资料是我国气象部门进行气候分析和科研服务的宝贵资源,但由于其数据量巨大而却以离散的文件形式保存,还没有得到有效的开发和利用。本文结合开源数据库firebird实现了区域站资料整理软件,该软件可以将全国区域站多种不同数据格式的数据文件进行解析并导入到firebird数据库系统中,利用数据库的统计功能对区域站资料进行质量控制、日统计值数据计算,最后按照新一代气象信息共享平台项目要求的格式输出数据资料。

关键词： Query optimization   Distributed database system   Ant colony optimization   Join queries   Cost model  

摘要： Distributed database systems provide a new data processing and storage technology for decentralized organizations of today. Query optimization, the process to generate an optimal execution plan for the posed query, is more challenging in such systems due to the huge search space of alternative plans incurred by distribution. As finding an optimal execution plan is computationally intractable, using stochastic-based algorithms has drawn the attention of most researchers. In this paper, for the first time, a multi-colony ant algorithm is proposed for optimizing join queries in a distributed environment where relations can be replicated but not fragmented. In the proposed algorithm, four types of ants collaborate to create an execution plan. Hence, there are four ant colonies in each iteration. Each type of ant makes an important decision to find the optimal plan. In order to evaluate the quality of the generated plan, two cost models are used-one based on the total time and the other on the response time. The proposed algorithm is compared with two previous genetic-based algorithms on chain, tree and cyclic queries. The experimental results show that the proposed algorithm saves up to about 80 % of optimization time with no significant difference in the quality of generated plans compared with the best existing genetic-based algorithm.

关键词： Documentation system   Data management   Clinical trials   Data capture   Information systems   Electronic analysis  

摘要： In radiation oncology, where treatment concepts are elaborated in interdisciplinary collaborations, handling distributed, large heterogeneous amounts of data efficiently is very important, yet challenging, for an optimal treatment of the patient as well as for research itself. This becomes a strong focus, as we step into the era of modern personalized medicine, relying on various quantitative data information, thus involving the active contribution of multiple medical specialties. Hence, combining patient data from all involved information systems is inevitable for analyses. Therefore, we introduced a documentation and data management system integrated in the clinical environment for electronic data capture. We discuss our concept and five-year experience of a precise electronic documentation system, with special focus on the challenges we encountered. We specify how such a system can be designed and implemented to plan, tailor and conduct (multicenter) clinical trials, ultimately reaching the best clinical performance, and enhancing interdisciplinary and clinical research. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

关键词： Storage provisioning   Data layout   Resource allocation   Total operating cost   Query optimization   I/O subsystems   SSD  

摘要： Data center operators face a bewildering set of choices when considering how to provision resources on machines with complex I/O subsystems. Modern I/O subsystems often have a rich mix of fast, high performing, but expensive SSDs sitting alongside with cheaper but relatively slower (for random accesses) traditional hard disk drives. The data center operators need to determine how to provision the I/O resources for specific workloads so as to abide by existing service level agreements, while minimizing the total operating cost (TOC) of running the workload, where the TOC includes the amortized hardware costs and the run-time energy costs. The focus of this paper is on introducing this new problem of TOC-based storage allocation, cast in a framework that is compatible with traditional DBMS query optimization and query processing architecture. We also present a heuristic-based solution to this problem, called DOT. We have implemented DOT in PostgreSQL, and experiments using TPC-H and TPC-C demonstrate significant TOC reduction by DOT in various settings.

关键词： 中学地理教学   GIS   信息化发展水平   地理信息资源   地理学科   可行性分析   数据库管理系统   教学效果   信息技术   教育理念  

摘要： 随着新课程的改革,各学科均将本专业信息化领域的知识带入教育教学中,作为与生活息息相关的地理学科,引入GIS辅助教学也应当提上日程。面对我国当前信息化发展水平相对较低、应用程序软件可选择范围较窄、教师信息化水平有限,以及可用地理信息资源(数据)严重匮乏等现状,大力开展GIS教学尚不现实。因此,地理教师需要开阔视野、勇于探索,将现代信息技术应用于实际教学。一、充分理解GIS的含义,加强对教育理念的认识GIS即地理信息系统,是基于数据库管理系统的分析和管理空间对象的信息系统,于20世纪60年代中期发展起来,经过了40年的发展历程。

关键词： C#   NET   Framework   ADO   SQL   SERVER   边坡系统开发  

摘要： 高速公路边坡稳定性分析,是高速公路建设的一项很重要的工作与重点内容。文章以边坡实时监测系统研究系统得出的数据为基础,基于.NET为基础开发平台,建立了边坡数据库管理系统。该系统包含边坡的基本数据、开挖前每段合同段的实时照片、每一开挖级数的实时照片及工程情况与边坡稳定性分析的建议和措施。可为高速公路的建设和运营管理提供技术支持。