数据库与MapReduce融合的大数据管理技术探索

大数据管理是随着时代和技术发展而提出和演化的命题。随着大数据从传统的结构化数据向无结构化数据的转移,Key/value存储、NoSQL、MapReduce等技术成为数据库技术之外大数据管理的多样化手段。MapReduce以其开放性成为当前大数据的代表技术,在大数据应用中,如何让MapReduce与数据库高效协同,发挥各自的技术优势和平台优势,提供高性能、高可扩展性、高可用性的大数据服务平台成为重要的研究课题。本文讨论在大数据存储、管理与服务主题上的观点和技术路线,探索将MapReduce作为数据库新的应用与开发平台的可行性。     

云计算数据库中集成化数据智能挖掘算法研究

为实现高效、快速、准确的信息挖掘,笔者设计了一种云计算数据库中集成化数据智能挖掘算法,通过研究基于MapReduce的云计算平台集成化数据智能挖掘技术,对yarn云计算的智能挖掘算法架构进行划分,完成对集成化数据的映射归约,利用HDFS编程构建模型。实验结果表明:运用MapReduce的云计算可以更高效、精准地完成集成化数据智能挖掘。     

数据库网格:基于网格的多数据库系统

近年来,数据网格技术的快速发展为广域分布环境下的海量数据共享提供了强有力的支持。数据库网格是指主要由各种数据库管理系统构成的数据网格环境,其技术难点是在网格环境下研究解决分布式查询、事务、多数据源视图等传统的数据库领域的问题。该文通过讨论数据网格、数据库网格和多数据库的概念和特点,并比较上述问题在多数据库和数据库网格环境下的异同,对数据库网格的特点进行了总结,对数据库网格技术的研究和发展方向进行了探讨和展望。     

数据库应用系统中LOB应用技术研究

为解决某专项技术数据库应用系统中多类型文档数据、图像数据等大对象数据的组织、存储、管理和高效访问技术问题,研究了应用 Oracle 9i 数据库管理系统对大对象类型数据进行集中存储和统一管理的技术,以及基于 JSP 的网络数据库应用系统对大对象数据的数据访问和数据显示技术.提出采用 Oracle 9i 中 LOB 和 Long Raw 数据类型对大对象数据进行存储和管理,以数据流的形式实现大对象类型数据的输入和输出,并基于 JSP 语言设计客户端软件,提供方便的图形用户接口,有效解决了数据库应用系统中大对象数据的存储、访问与显示问题.     

大数据背景下数据库技术应用分析

进入大数据时代,信息技术在各行各业得到广泛应用,其中数据库技术经不断发展,技术不断进步,对很多行业的发展起到极大地推动作用,本文主要从数据库技术的相关概念与特点出发,分析数据库技术当前的应用现状,探究大数据背景下数据库技术的应用方向以及如何更好的应用大数据技术。     

基于大数据的计算机数据库连接访问技术分析

在互联网技术不断发展的过程中,数据信息资源量也在不断增加,使人类社会进入大数据时代。在大数据时代,数据库作为一种重要的技术,能够对数据进行读写、存储操作,从而能够有效、快捷地为分布式管理系统提供服务。在此背景下,本文对基于大数据计算机数据库连接访问技术进行分析,以提高数据库访问链接性能。     

数据库应用系统中LOB应用技术研究

为解决某专项技术数据库应用系统中多类型文档数据、图像数据等大对象数据的组织、存储、管理和高效访问技术问题,研究了应用Oracle 9i数据库管理系统对大对象类型数据进行集中存储和统一管理的技术,以及基于JSP的网络数据库应用系统对大对象数据的数据访问和数据显示技术。提出采用Oracle 9i中LOB和Long Raw数据类型对大对象数据进行存储和管理,以数据流的形式实现大对象类型数据的输入和输出,并基于JSP语言设计客户端软件,提供方便的图形用户接口,有效解决了数据库应用系统中大对象数据的存储、访问与显示问题。     

一种基于MapReduce的最近似k对数据搜索方案

多种应用场合需要寻找给定数据库中相似度最大的前k对数据。然而由于应用领域需要处理的数据规模呈上升趋势,计算这样的最相似k对数据,难度非常大。提出一种基于MapReduce的最相似k对数据搜索方案,该方案首先将所有数据对分割成多个组,然后提出所有数据对分组算法和核心数据对分组算法,通过单独计算每个组中的最近似k对数据,从所有组的最近似k对数据中选择相似度最高的k对数据,进而确定最近似k对数据。最后基于合成数据和真实数据进行实验,性能评估结果表明本文MapReduce算法的有效性和可扩展性。     

基于物联网海量数据处理的数据库技术分析与研究

随着物联网发展速度的不断加快,对海量数据处理技术也提出了更高的要求。物联网数据具有实时性、海量性与多态性、异构性等特点,因此其海量数据处理技术也具有一定的特殊性。针对物联网海量数据的新需求,本文首先对物联网数据海量性、异构性、数据多维性与数据关联性、实时性与动态化等特点进行了分析,在此基础上主要分析与研究了物联网海量数据处理的数据库技术,包括分布式内存数据库技术与分布式实时数据库技术两种。     

使用MapReduce构建列存储数据的索引

大数据的存储与分析是近年来数据库领域研究的热点,高效的索引技术是提高大数据查询分析性能的重要技术手段。在现有的数据存储模型及索引技术研究基础上,提出使用MapReduce构建列存储数据的索引。该索引技术结合MapReduce编程模型,先在Map阶段完成数据划分,然后在Reduce阶段完成数据的排序,最后在数据有序的Reduce节点上创建RB+树索引,从而减少索引创建时因为RB+树内部节点递归分裂而产生的昂贵代价和树的高度,提高数据查询的性能。通过在真实数据集上进行实验,验证了所提出方法的有效性。     

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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