Web开发中高效安全的数据持久层研究

本文阐述了企业数据的重要性,分析了当前流行的持久层解决方案的优缺点,并给出了基于XML的设计模式,建立一个高性能、高安全性、有弹性、可拓展性的数据持久层的方法.同时用一个信息查询的完整业务流程解释了持久性框架的主要设计思想.     

对象序列化技术在HLA仿真数据处理中的应用

在仿真数据的处理过程中,数据的持久存储以及在不同应用间的交互是需解决的关键问题。在面向对象领域,对象持久能力是使对象具备持久保存和动态恢复自身的能力,这一特点可用于构建仿真数据的持久存储和交互格式。对象序列化技术是支持对象实现持久性的重要机制,对此研究了一种将对象序列化技术改造用于高层体系结构（HLA）仿真数据处理的方法。该技术方法已经应用在作战仿真领域的实际系统中,结果表明基于对象序列化的仿真数据持久存储和交互格式使用起来更加方便并使数据处理效率得到提高。     

基于J2EE多层架构的Web开发框架研究*

在经典的J2EE四层体系结构的基础上增加数据持久层,提出了基于J2EE五层体系结构的Web开发框架;分析了基于Struts框架的J2EE架构中实现对象持久性的局限性,从中分离出对象持久层,并将Hibernate这个面向对象的轻量级对象持久性技术集成到该架构中;应用DAO设计模式在业务逻辑层与持久层之间设计了多源数据访问组件,抽象和封装了对不同数据源的数据访问操作,实现对不同类型、结构、环境、用法的异构数据库的统一访问。     

面向通用HPC的高性能DSP设计权衡

GPU由于其计算能力高达数TFLOPS,被高性能计算领域用于加速并行运算.但GPU较低的峰值性能利用率和功耗效率,已经成为了系统性能进一步提升的瓶颈.为了解决这个问题,作者开始研究将高性能DSP用于通用高性能计算领域.为了高效支撑通用高性能计算,文中提出了高性能DSP的结构框架,并通过映射GotoBLAS库到该结构上,建立了GEMM在该结构上的性能模型.作者研究了影响GEMM效率的主要因素,包括性能、存储层次、核的大小以及核的数量.文中总结了一些有指导意义的结论用于构建面向通用高性能计算的高效DSP.实验结果表明,通过尽可能少的硬件代价,可以在TFLOPS DSP上获得接近峰值的性能.     

OODB的支撑技术—持久程序设计语言（O＋＋和E的探讨）

持久程序设计语言是实现当前很有发展前途的面向对象数据库的一种支撑技术。这种技术是通过面向对象程序设计语言的扩充，使之具有持久存储的设施，从而能够用来构造出关系数据库中任意复杂的持久的数据结构。本文主要介绍了Ｏ＋＋和Ｅ这两种具有代表性的持久程序设计语言，并描述了如何解决在实现面向对象数据库过程中所遇到的诸如隐蔽指针、持久性和数据类型的无关性等几种困难问题。文章还比较了这两种语言的优缺点，希望能对面向     

基于OMNet＋＋的主从式异构物联网仿真平台的研究

本文分析并研究了融合GPRS和WLAN网络协议的主从式异构网络的物联网的系统性能,通过在OMNet＋＋框架内进行建模,搭建仿真平台。在这种网络模型中,传感器网络的主节点同时作为局域网网关工作。通过仿真实际异构物联网场景的性能测试,研究网络延时、正确送达率与节点数量、报文长度等的关系,以实现在大规模搭建传感器网络前根据具体的网络性能和通信质量要求进行整体部署。     

Hibernate对象管理研究

该文分析了Hibernate框架在应用程序持久层的位置、原理和重要意义。深入研究了Hibernate对象生命周期中的三种状态及其转化关系,并用实际开发中的典型程序段进行了直观形象地说明。阐明了Hibernate的Session缓存对数据持久性能的优化机制[1]。对准确、高效地操作Hibernate对象,编写高质量的持久层应用程序具有重要的参考价值。     

Hibernate对象管理研究

该文分析了Hibernate框架在应用程序持久层的位置、原理和重要意义。深入研究了Hibernate对象生命周期中的三种状态及其转化关系,并用实际开发中的典型程序段进行了直观形象地说明。阐明了Hibernate的Session缓存对数据持久性能的优化机制[1]。对准确、高效地操作Hibernate对象,编写高质量的持久层应用程序具有重要的参考价值。     

持久性操作系统及其相关技术

在正交持久性系统中，所有数据都是持久的，并可用相同的方式访问。程序设计语言层面的持久性支持具有性能低下、功能重复等缺点，操作系统级别的持久性支持才是更好的解决方案。本文首先介绍正交持久性的概念，然后分析持久性操作系统的需求并给出它的定义，接下来讨论持久性地址空间、影式分页和日志式分页等技术，最后研究一个持久性操作系统一GIrasshopper的设计。     

基于HLA/RTI的供配电仿真系统设计

针对传统供配电仿真系统的不足,本文提出基于HLA／RTI设计仿真系统框架,同时使用VegaPrime软件和Creator完成实时视景的开发,综合Visual C＋＋编程最终实现了一个具有一定先进性的供配电综合仿真系统。实践表明该仿真系统不仅可以用作电力运营的辅助工具,还可以为决策人员提供数据支持和决策建议,同时,还可用于对电力人员进行培训。     

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.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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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.