基于系统重建的数据采集器的设计与实现

以一个数据采集系统的设计与实现过程为例,介绍了一种对遗留系统开发行之有效的方法－系统重建。介绍了该采集系统重建的过程,通过这些介绍,可以看到重建思想的作用。最后讨论了系统重建过程中一些相关原则。     

TWC LOGD: A portal for linked open government data ecosystems

International open government initiatives are releasing an increasing volume of raw government datasets directly to citizens via the Web. The transparency resulting from these releases not only creates new application opportunities but also imposes new burdens inherent to large-scale distributed data integration, collaborative data manipulation and transparent data consumption. The Tetherless World Constellation (TWC) at Rensselaer Polytechnic Institute (RPI) has developed the Semantic Web-based TWC LOGD portal to support the deployment of linked open government data (LOGD). The portal is both an open source infrastructure supporting linked open government data production and consumption and a vibrant community portal that educates and serves the growing international open government community of developers, data curators and end users. This paper motivates and introduces the TWC LOGD Portal and highlights innovative aspects and lessons learned.     

关于分布式、异构、历史遗留数据的数据挖掘研究

主要研究在分布式、异构和历史遗留数据库中进行数据挖掘的方法和策略。首先讨论分布式数据库的挖掘方法,在此基础上进行扩展讨论异构数据源的数据挖掘方法;最后,讨论历史遗留数据库的挖掘方法。     

一种工业控制现场数据到开放平台移植的应用

工业控制系统的数据移植问题一直是解决现代工业企业信息化孤岛问题和改善生产自动化水平的热门研究课题。本文通过开放式数据库互联(ODBC)和基于数据对象的现行服务器页(ASP ADO)方法,实现工业控制现场数据到开放平台的移植。这种方法应用于具体工程实例,获得了满意效果。     

大数据背景下长江水文数据开放平台设计研究

科学数据共享对增强国家科技创新能力、促进社会和经济发展具有重要意义。为提升大数据背景下长江水文数据资源共享能力,在分析研究水文数据特点的基础上,提出水文数据开放能力的相关概念,同时结合水文数据开放应用需求,对构建具备数据和能力开放应用的开放平台建设体系进行研究,设计水文数据开放平台总体框架和功能结构。在此基础上,通过分析长江水文建设水文数据开放平台的基础和条件,提出开放平台的主要建设内容,阐述开放平台建设在数据开放范围、质量保障、开放友好性和安全性等方面面临的挑战,并针对性地从开放机制、产品形式、应用生态等方面提出对策建议,为开放平台落地应用提供重要技术保障。     

Multidimensional data modeling for location-based services

With the recent and continuing advances in areas such as wireless communications and positioning technologies, mobile, location-based services are becoming possible.Such services deliver location-dependent content to their users. More specifically, these services may capture the movements and requests of their users in multidimensional databases, i.e., data warehouses, and content delivery may be based on the results of complex queries on these data warehouses. Such queries aggregate detailed data in order to find useful patterns, e.g., in the interaction of a particular user with the services.The application of multidimensional technology in this context poses a range of new challenges. The specific challenge addressed here concerns the provision of an appropriate multidimensional data model. In particular, the paper extends an existing multidimensional data model and algebraic query language to accommodate spatial values that exhibit partial containment relationships instead of the total containment relationships normally assumed in multidimensional data models. Partial containment introduces imprecision in aggregation paths. The paper proposes a method for evaluating the imprecision of such paths. The paper also offers transformations of dimension hierarchies with partial containment relationships to simple hierarchies, to which existing precomputation techniques are applicable.Received: 28 September 2002, Accepted: 5 April 2003, Published online: 12 August 2003Edited by: J. Veijalainen Correspondence to: I. Timko     

基于语言转换工具的遗产系统移植方法

解决遗产信息系统问题有三种策略:重新开发、封装和移植。由于前两者存在较大的缺陷,移植策略成为了重要的研究和应用领域。本文分析了目前已有的遗产系统移植方法的不足和未解决的问题,在此基础上提出了一种着重于实现代码自动移植的基于语言转换工具的移植方法,给出了一种具有灵活性和可操作性的通用移植过程模型。     

在VB中快速访问SQL Server数据库的方法

针对SQL Server系统所建立的数据库，分别就DQO、RDO ADO不同机制下的数据源访问列举出采用数据绑定控件和适应动态编程的非绑定控件的应用，着重对ADO方法进行了详解。     

多维数据概念模型的形式化描述

本文基于维层次间的部分包含关系及其传递性,对多维数据概念模型的形式化描述进行了初步研究,并首次从静态结构视图与功能结构视图两个方面对其进行了详细的阐述;同时还从基本代数操作、模型分析操作、模型维护操作三个方面对该模型支持的操作进行了定义;最后还给出了该模型的构建方法。     

开放信息模型研究

元数据及其管理是数据仓库系统的核心部件,是内部技术人员开发与维护数据仓库的蓝图,是商业终端用户导航数据仓库以及定位有用信息的路标。该文详细介绍了元数据联盟的开放信息模型的总体结构和底层技术标准。     

时空大数据资源集成框架设计与应用

随着地理空间信息技术的快速发展,产生了大量形式各异的时空数据资源与服务应用。针对资源共享存在的服务互操作、消息传输、数据同步和数据传输等技术瓶颈问题,提出一种时空大数据资源集成框架(STDRIF)。采用松耦合模块化的方式,形成一套从数据资源集成到服务调用的完整技术体制,可以有效整合各类时空数据资源。以J2EE架构应用为例,验证了STDRIF的可用性并进行性能分析。实验结果表明,STDRIF具有较高的性能和良好的用户体验。     

中国西部环境与生态科学数据中心的数据服务理念与成效

数据服务是科学数据共享的实现方式,完善的数据服务对于促进数据共享具有重要意义。中国西部环境与生态科学数据中心从2006年成立到现在稳定运行,数据服务理念经历了从简单到较为完善的转变过程,认识到保护数据知识产权、数据质量控制、持续扩充数据资源和主动服务的重要性,并针对这些问题提出了数据共享审核、数据引用、数据评审和数据汇交等可行的服务手段,提高了数据中心的服务质量,有力推动了科学数据的共享氛围。     

Can urban pluvial flooding be predicted by open spatial data and weather data?

Cities are increasingly prone to urban flooding due to heavier rainfall, denser populations, augmenting imperviousness, and infrastructure aging. Urban pluvial flooding causes damage to buildings and contents, and disturbs stormwater drainage, transportation, and electricity provision. Designing and implementing efficient adaptation measures requires proper understanding of the urban response to heavy rainfall. However, implemented stormwater drainage models lack flood impact data for calibration, which results in poor flood predictions. Moreover, such models only consider rainfall and hydraulic parameters, neglecting the role of other natural, built, and social conditions in flooding mechanisms. This paper explores the potential of open spatial datasets to explain the occurrence of citizen-reported flood incidents during a heavy rain event. After a dimensionality reduction, imperviousness and proximity to watershed outflow point were found to significantly explain up to half of the flooding incidents variability, proving the usefulness of the proposed approach for urban flood modelling and management.     

Measurement and defect modeling for a legacy software system

This paper analyzes the quality of a large-scale legacy software system using selected metrics. Quality measurements include defect information collected during product development and in-field operation. Other software metrics include measurements on various product and process attributes, including design, size, change, and complexity. Preliminary analyses revealed the high degree of skew in our data and a weak correlation between defects and software metrics. Tree-based models were then used to uncover relationships between defects and software metrics, and to identify high-defect modules together with their associated measurement characteristics. As results presented in tree forms are natural to the decision process and are easy to understand, tree-based modeling is shown to be suitable for change solicitation and useful in guiding remedial actions for quality improvement.The following are trademarks or service marks in the United States and/or other countries: IBM is a trademark of International Business Machines Corporation. REFINE and Software Refinery are trademarks of Reasoning Systems Inc. SAS is a trademark of the SAS Institute Inc. S-PLUS is a trademark of the Statistical Sciences, Inc.