面向流量控制的可扩展策略库的设计与实现

Linux提供了一套功能强大的流量控制机制,成为当前实现网络QoS的重要工具.针对制定流量控制方案时带宽划分精度和粒度难以权衡,采用单一队列调度算法实施流量整形效果不尽如人意等问题,提出了基于可扩展策略库的流量控制管理方案,在Linux下设计并实现了可扩展流量控制策略库.介绍了该策略库的3个模块:策略存储实体、出错回滚监控模块和可扩展策略库管理模块.定义了策略的存储格式,将主机、服务、时间、上下行方向等元素综合管理起来.同时提出了结合优先级调度的策略添加、删除、合并的策略管理算法.通过实验分析证明该流量控制管理方案的有效性和实用性.     

一种基于事件处理函数的GUI测试方法

事件处理函数响应用户GUI(graphic user interface)操作并完成软件预定义功能,事件处理函数以及事件处理函数之间的关系实现是否与规约一致,是GUI 测试的重点.针对现有的基于模型GUI 测试用例自动生成过程中面临的测试用例规模庞大以及生成的测试用例无效问题,从分析事件处理函数的角度出发,提出了一种GUI 测试模型EHG.针对此模型,结合事件处理函数及其代码结构,提出了两个测试覆盖准则：完整最短路径覆盖准则和完整最短路径定义-引用对覆盖准则;利用基于反馈的测试用例生成技术生成测试用例.实验结果表明,针对较为复杂的应用,该方法不仅能够有效控制测试用例规模,消除无效测试用例,而且生成的测试用例能有效提高事件处理函数的代码结构覆盖率.     

分布式RFID复杂事件处理技术的研究

目前RFID复杂事件处理技术的研究主要针对集中式的处理。集中式RFID复杂事件处理技术对于海量RFID数据的处理具有很多局限性,主要表现为网络通讯代价高和处理效率低。针对集中式RFID复杂事件处理存在的问题,本文研究了分布式环境下RFID复杂事件处理的关键算法,采用一种Pull(抽取)类型的数据通讯模型来降低通讯代价,在此基础上提出了两种分布式的RFID复杂事件处理算法。实验结果表明,本文提出的分布式RFID复杂事件处理算法比集中式复杂事件处理算法更有效。     

不可靠RFID数据上的复杂事件处理研究*

通过在基于NFA的复杂事件处理算法中引入可靠性约束检测,提出了一种直接应用于不可靠RFID数据上的复杂事件处理算法。实验结果表明该方法是有效和高效的。     

基于复杂事件处理的算法交易研究

在目前的资本市场,算法交易得到了广泛的应用.通过实时分析大量的金融市场数据,算法交易能够合理地决定交易的时机、价格、数量等交易的各个方面.现有的一般架构通常采用存储-索引-查询的数据库建模方法,但是这不能满足实时处理要求.复杂事件处理是构建和管理由事件驱动的信息系统的一种新兴技术.它用来处理大量的事件流,实时分析这些事件并且响应感兴趣的事件.针对于此,提出了基于复杂事件处理的算法交易架构模型,并在此基础上,提出了对应的事件模型以及设计了一个有效的检测复杂事件的算法.     

实时事件服务设计与实现

提出一个扩展标准ＣＯＲＢＡ事件服务的方案,通过在标准事件服务事件通道中增加事件描述过滤模块、优先级和时间设定模块、调度模块和相关事件处理模块,并对原有消费者代理和供给代理模块的功能扩充,使之有进行实时事件处理、实时事件广播等满足实时应用要求的实时事件服务。     

基于遗传算法的信息流安全标记自动化挖掘

分布式信息流模型可以细粒度地控制信息的访问和传播,但其灵活性也增加了系统安全需求表达和策略管理实施的复杂性,严重制约了模型在云计算等分布式系统中的应用。对此,设计了一种基于安全断言的策略描述语言以表达安全需求;形式化定义了信息流安全标记挖掘问题,分析并证明了该问题是NP完全问题;提出了基于遗传算法的标记挖掘近似最优化算法。实验结果表明,算法可自动挖掘出策略配置最优解方案,有效提高了分布式信息流模型在实际系统中的可用性。     

新一代分布式的复杂事件处理系统解决方案

本文首先对复杂事件处理系统建设的驱动力进行介绍,然后结合系统的特性要求提出一套针对性的实现方案。该方案通过Storm结合策略处理引擎、消息队列和分布式缓存构建一套高可用性通用复杂事件处理系统,满足用户对复杂海量实时信息处理分析的需求。     

基于模型检测的信息流策略安全性分析

分布式信息流控制是增强系统安全的一种有效方法,但其灵活性也增加了策略管理和分析的复杂性。策略的安全性分析判定系统的所有可达状态是否都能保持特定的安全属性,可以验证策略是否一致完备的满足安全需求。形式化定义了基于Kripke结构和计算树时序逻辑的信息流策略安全性分析问题,验证信息流允许、禁止和授权管理三类信息流安全目标。提出了分支限界和模型检测两种策略验证算法,实验结果表明,算法可有效验证分布式信息流控制系统是否满足特定安全需求,提高了分布式信息流控制的可用性。     

基于事件处理的JAVA切片

Event是一类特殊的对象,它在Java中与被创建的控件相关联,并通过对应的监听器接收消息而激发相应的事件处理程序。本文提出了一种合理的新方法,在系统依赖图中表示事件处理模块,利用图可达性算法计算事件处理切片。     

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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