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The paper describes a prototype system called HiSQL (Historical SQL) which extends the functionality of SQL in manipulating
historical data, by providing functions for spatial and temporal processing. Conceptually the paper is divided into three
parts: the first part deals with the design and architecture of the system; the second part introduces a case study (the defters);
and the third part describes specific functions for spatial and temporal processing of serial documents. The paper concludes
with a comparison between HiSQL and SQL and suggestions for further work.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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陈树岗 《计算机研究与发展》1992,29(1):23-28
本文介绍一个以DECnet-VAX计算机为主干的远程网络。开发研制内容包括NECACOS和其他异种机入网、文电处理、点对点终端实时会话、文件传送、NECPC-9801微机终端仿真等功能的综合信息系统。讨论了它的主要功能和实现技术。 相似文献
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We present BLAS, a Bi-LAbeling based XPath processing System. BLAS uses two labeling schemes to speed up query processing: P-labeling for processing consecutive child (or parent) axis traversals, and D-labeling for processing descendant (or ancestor) axis traversals. XML data are stored in labeled form and indexed. Algorithms are presented for translating XPath queries to SQL expressions. BLAS reduces the number of joins in the SQL query translated from a given XPath query and reduces the number of disk accesses required to execute the SQL query compared with the traditional XPath processing using D-labeling alone. We also propose an approximate P-labeling scheme and the corresponding query translation algorithm to handle XML data trees that contain a large number of distinct tag names, and/or are very deep. This extension captures a spectrum of XPath-to-SQL query translation schemes, ranging from existing schemes that do not use P-labels to the one that uses exact P-labels. Experimental results demonstrate the efficiency of the BLAS system. 相似文献
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基于B/S模式的通用试题库系统的设计与实现 总被引:4,自引:0,他引:4
本文介绍一个基于B/S模式的通用试题库系统的设计思想,并详细阐述其在Visual Studio环境下基于SQLServer 2000数据库和ASP.net、ADO.net、ODBC等技术的实现方法。该系统在结构上被划分为数据、功能和应用三个层次,实现了数据库构建,试题库建立,试题录入、查询和管理,对使用记录的处理,手工组卷,自动组卷,试卷的生成、预览、打印和管理等功能。该系统的技术实现使其具备良好的开放性、安全性、稳定性及通用性,目前已经投入使用且运行良好。 相似文献
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We have extended the canonical relational data model to enable the management of multimedia objects. In an attempt to provide a smooth paradigm shift to multimedia information system development, we have enhanced the relational data model framework with techniques for modeling, storing and manipulating multimedia data. In particular, we have provided a graphical conceptual model for structuring a multimedia document and mapping rules for translating it into an extended relational data schema. Extensions have regarded the management of foreign keys, active components, mechanisms for the management of spatial and temporal relations, and finally functions for handling multimedia presentations. As a consequence, we have also provided extensions to the SQL language to handle these new mechanisms. 相似文献
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Hui Lin Bo Huang 《Knowledge and Data Engineering, IEEE Transactions on》2001,13(4):671-682
An important trend of current GIS development is to provide easy and effective access to spatial analysis functionalities for supporting decision making based on geo-referenced data. Within the framework of the ongoing SQL standards for spatial extensions, a spatial query language, called SQV/SDA, has been designed to meet such a requirement. Since the language needs to incorporate the important derivation functions (e.g., map-overlay and feature-fusion) as well as the spatial relationship and metric functions, the functionality of the FROM clause in SQL is developed in addition to the SELECT and WHERE clauses. By restructuring the FROM clause via a subquery, SQL/SDA is well-adapted to the general spatial analysis procedures using current GIS packages. Such an extended SQL, therefore, stretches the capabilities of previous ones. The implementation of SQL/SDA on the Internet adopts a hybrid model, which takes advantage of the Web GIS design methods in both the client side and server side. The client side of SQL/SDA, programmed in the Java language, provides a query interface by introducing visual constructs such as icons, listboxes, and comboboxes to assist in the composition of queries, thereby enhancing the usability of the language. The server side of SQL/SDA, which is composed of a query processor and Spatial Database Engine (SDE), carries out query processing on spatial databases after receiving user requests 相似文献
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首先回顾了时空数据处理与分析的发展历史,探讨了开展智能化研究的必要性,并提出了具有层次结构的时空数据智能化处理和分析的体系结构,结合第四代基本特征的地理信息系统的理论和技术,提出发展地理智能系统需要着重解决几个关键问题:地学知识的表达与推理,建立多尺度时空数据融合模型,时空数据统计特性的模型化表达,引进人工智能领域最新方法,设计有效,快速的时空数据的特点表达,分析,数据挖掘,知识发现等算法,表成一系列时空数据的智能化处理和分析功能。 相似文献
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Database Based Reasoning for Real Time Monitoring and Data Analysis in Intensive Care Units 总被引:1,自引:0,他引:1
The complexity of the monitored data available in modern intensive care units (ICUs) means that they are best processed, for presentation to medical staff, by expert system techniques. This article describes an expert system that has an appropriately designed inference engine, handling the temporal considerations inherent in monitoring and manages data acquisition via a Medical Information Bus. Also, we will describe how we extended our monitoring system in ICUs by writing an interface allowing communication in dynamic SQL with a relational database management system. The extended system facilitates both permanent filing of case data and the use of filed data by the rules of the expert system, and allows automatic intelligent screening of data prior to permanent filing so as to ensure data reliability. 相似文献
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在太阳磁场观测系统中通过使用相关跟踪算法发现并消除原始图像间的抖动错位,提高磁场观测数据的空间分辨率。然而相关算法的实现比较耗时,为保证系统观测数据的时间分辨率,系统中采取了缩小相关窗口的尺寸——选取特征区域作为相关窗口的局部相关跟踪算法,并结合快速傅立叶算法和IntelR图像处理函数库等方法优化相关运算,提高了系统的时间分辨率。系统指标满足常规天文观测的要求并已投入使用。 相似文献
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GIS环境下融合实时交通数据的交互系统 总被引:3,自引:0,他引:3
论述了如何在地理信息系统环境下集成实时交通数据,开发可交互系统。开发的目的主要有两点:1.充分利用数据库功能,增强当前交通监控系统能力;2.开发可视化智能分析工具,充分发挥当前交通监控系统的能力。文中分析了系统动态实时交通数据的数据库环境,讨论了交通数据实时融合、集中在GIS应用中的数据接口模块,并从时空两方面提供可视化和智能分析工具。为了便于分析,文章以北京交通管理局的地理信息系统开发为例。 相似文献
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陈翠松 《数字社区&智能家居》2009,(23)
答疑一直是教学中的一个重要环节,随着计算机技术和网络技术的深入发展,答疑的方式也越来越多,越来越灵活,但都存在一些不足,该文应用.NET技术和SQLServer工具设计了的一个基于B/S的三层体系结构的网上答疑系统。该系统可以实现不同类型用户的权限控制,多课程管理,问题管理等功能,而且系统采用实名制增加系统的安全性和有效性。 相似文献
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分布式流查询是一种基于数据流的实时查询计算方法,近年来得到了广泛的关注和快速发展。综述了分布式流处理框架在实时关系型查询上取得的研究成果;对涉及分布式数据加载、分布式流计算框架、分布式流查询的产品进行了分析和比较;提出了基于Spark Streaming和Apache Kafka构建的分布式流查询模型,以并发加载多个文件源的形式,设计内存文件系统实现数据的快速加载,相较于基于Apache Flume的加载技术提速1倍以上。在Spark Streaming的基础上,实现了基于Spark SQL的分布式流查询接口,并提出了自行编码解析SQL语句的方法,实现了分布式查询。测试结果表明,在查询语句复杂的情况下,自行编码解析SQL的查询效率具有明显的优势。 相似文献
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描述了高光谱图象处理与分析系统软件的系统设计,体系结构和主要特点,阐述了高光谱图象处理系统应具备的功能以及面向对象的设计方法在软件系统设计中的应用。实验表明,采用面向对象的设计方法和新一代的编程文3,可以快速开发出性能满足高光谱图象处理。 相似文献
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采用B/S模式结构,以.NET 2.0为开发平台,使用VB语言,后台连接SQL Server 2005数据库,设计并实现在线考试系统。本文主要对系统的需求分析、功能模块、数据存储结构以及编码实现等几个方面进行了阐述。 相似文献