结构图ETL概念模型的设计方法

ETL过程是数据仓库获得高质量数据的重要环节,是任何数据仓库工程不可缺少的成功因素。为了便于ETL过程的设计和维护,降低ETL过程的设计、维护代价,提出一种基于结构图的ETL概念模型设计方法,给出一个用于描述ETL过程的模型,并基于CWM完成用以存储元数据的ETL元模型的设计。通过图形化ETL过程中的元素和关联,该模型清晰直观地反映了各个源数据库与目标数据仓库的内部结构和组成、数据的来源与流向、源数据和目标数据之间的映射和转换关系,辅助设计人员更好地进行ETL过程的设计和编码实现,使整个ETL的设计与维护过程更加方便、灵活、有效。     

基于元数据驱动的ETL架构设计

ETL(Extract-Transform-Load)是数据仓库获得高质量数据的重要环节,一个设计良好、功能强大的ETL工具对于构建一个数据质量、结构良好的数据仓库有着重要意义。首先分析了传统ETL架构的局限性以及元数据管理对ETL过程的重要性,然后对传统的ETL架构进行改进,结合元数据管理思想,提出并设计了一种新的基于元数据驱动的ETL架构。结果表明,该ETL架构通过增加数据中转区并使整个ETL过程在元数据的指导下进行,有效保证了数据仓库的数据质量,提高了数据装载的效率,减轻了数据源和目标数据库的压力,增加了数据转换的灵活性和可靠性。     

保险业数据参考模型对ETL的影响和作用

本文在简略回顾保险业通用数据参考模型之后,以数据仓库技术中的ETL过程为着眼点,对基于保险业数据参考模型的ETL过程进行设计和分析,从而有针对性地提出一种保险行业数据抽取转换和加载的方法,最后探讨该设计在保险公司的应用.     

点击流数据仓库中的ETL设计

ETL是构建数据仓库过程中极其重要的部分,点击流数据仓库无论在体系结构上,维表与事实表设计上,还是点击流的抽取、转换和装载机制上,都比传统的数据仓库要复杂的多。本文以ETL基本原理出发,构造ETL体系结构,着重分析点击流数据仓库的ETL技术,进行数据抽取,数据转换,以及数据装载的ETL设计,为ETL系统的开发和ETL技术的应用提供了依据。     

数据仓库的建立与维护的一个实例

本文描述了在学校学生管理系统的基础上建立和维护数据仓库的过程,包括数据仓库模型设计、异构数据的转换、数据冗余、汇总数据存储等数据仓库设计过程和数据的抽取、转换和加载(ETL)以及元数据管理等维护过程,并简单地介绍了数据仓库在OLAP方面的应用。     

增量ETL过程中对删除数据实现装载的设计

使用ETL过程将数据源数据装载到数据仓库,大多数时候是向数据仓库中追加数据,但有时也需要删除一些数据,以维持数据仓库中数据的正确性.文章结合Oracle ETL工具的装载特点提出了一种对增量数据进行预处理的方法,以实现有删除数据的ETL装载,并给出了具体的设计.     

银行零售贷款风险管理系统分析

在数据仓库项目的实施过程中，ETL是数据仓库的核心和灵魂。它按照统一的规则集成并提高数据的价值，是负责完成数据从数据源向目标数据仓库转化的过程。是实施数据仓库的重要步骤。本文分析了银行贷款风险管理系统的实现。并介绍了ETL部分设计的方法。     

高校财务项目管理系统的数据仓库的设计

数据仓库系统是存储大量历史数据供分析和对决策进行支持的系统,本文详细描述了在高校财务项目管理系统的基础上建立和维护数据仓库的过程,包括数据仓库模型设计、异构数据的转换、数据冗余、汇总数据存储等数据仓库设计过程和数据的抽取、转换和加载（ETL）以及元数据管理等维护过程,并简单地介绍了数据仓库在OLAP方面的应用。     

一种可靠的数据仓库中ETL策略与架构设计

作为数据仓库系统的关键部件,ETL完成数据抽取、清洗、转换和装载的工作,它是构建数据仓库的重要环节,同时也是构建数据仓库过程中出现问题最多的环节,所以针对这点,该文给出了一个可靠的同时易于扩展的ETL策略和架构。文章首先简单地介绍了数据仓库技术和ETL技术,包括ETL的相关概念、ETL在数据仓库中的功能和重要地位;然后重点介绍了这种ETL的具体策略和架构设计。     

数据仓库中ETL技术的研究

作为数据仓库的关键部件,支持数据抽取、清洗、转换和装载的工具集对任何数据仓库工程都是一个必不可少的成功因素。该文简单介绍了ETL技术,包括ETL的相关概念、ETL在数据仓库中的功能和重要地位以及现有的研究成果,然后重点介绍了ETL的具体设计和实现方法。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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