移动Ad Hoc网络联合路由入侵检测模型研究

无线移动Ad Hoc网络是一种新型的无线移动通信网络,由于其动态拓扑、无线信道以及资源有限等特点,容易遭受各种攻击。特别地,由于网络中的每个节点都参与路由,Ad Hoc网络路由协议自身的安全性尤为重要。以入侵检测技术为基础,分析针对AODV路由协议的各种攻击,提出了一种新的、有效的将有限状态机（FSM）协议分析和支持向量机（SVM）统计学习方法相结合的无线移动Ad Hoc网络路由入侵检测模型,该模型通过检测针对路由协议的各种攻击来实现安全路由。通过NS-2网络仿真实验表明：基于FSM和SVM相结合的混合入侵检测机制具有较高的检测精度和检测性能。     

AODV协议在嵌入式平台中的应用研究

文中介绍了一个在嵌入式Linux系统上实现无线Ad—Hoc网络的应用,目的旨在建立一个基于嵌入式Linux和DevKit8000的嵌入式无线网络平台,并在嵌入式开发板中部署运行AODV路由协议,通过对AODV路由协议在嵌入式开发平台中的运行情况进行实验并分析,验证基于嵌入式开发平台的无线自组织网络部署运行AODV路由协议并组网的可行性。实验表明所移植的AODV路由协议运行稳定可靠,通过分析实验数据,体现了AODV路由协议在一定程度上具有稳定性,同时Ad-Hoc网络运行正常,各节点可通过运行的AODV路由协议进行稳定通信。     

AODV路由协议的安全性改进

针对Ad Hoc网络易遭受黑洞攻击而造成大量丢包现象的安全问题,提出了一种基于非合作博弈理论的安全路由方法。以Ad Hoc网络节点和恶意节点为对象建立双人博弈模型,理论分析证明该模型存在纳什均衡点,即对博弈的双方均存在优势策略。Ad Hoc网络根据自己的优势策略选择路由进行防御和网络传输,恶意节点根据自己的优势策略采取网络攻击行为。分析和仿真结果表明,新方法能有效地选择比较安全的路由,从而减少了恶意节点对Ad Hoc网络进行黑洞攻击造成的影响,降低了路由开销和网络丢包率。     

一种安全的Ad Hoc网络路由协议SGSR

Ad Hoc网络作为一种无线移动网络,其安全问题,特别是路由协议的安全备受关注。针对现有适合移动Ad Hoc网络的链路状态路由协议GSR无法防范恶意节点伪造、篡改、DoS攻击的现状,本文提出了一种在移动Ad Hoc网络中抵抗单个节点恶意攻击的安全路由协议SGSR,给出了认证协议的形式化证明,并对路由协议进行仿真和性能分析。     

基于GloMoSim的Ad Hoc网络路由协议仿真研究

针对24台移动终端在无线自组织网络中的联网通信需求,需要选择一种能够适应Ad Hoc网络拓扑结构不断变化的路由协议。文章对Ad Hoc网络的路由协议进行了分类和比较,并通过GloMoSim仿真平台,结合具体的网络仿真场景,着重对Ad Hoc网络中的AODV和DSR两种按需路由协议进行性能仿真测试,比较不同移动速度下两种协议的平均端到端时延、分组投递率和吞吐量性能优劣。实验表明,节点在GloMoSim平台中成功实现了通信互联,无论节点在静止状态还是高速移动情况下,AODV的性能都要优于DSR协议。     

时延容忍传感器网络中抗黑洞攻击的安全路由协议

时延容忍网络是一种在大部分时间内源节点和目的节点之间不存在端到端路径,而依靠存储转发机制实现异步通信的无线自组织网络。针对其黑洞攻击的问题,设计一种能够检测黑洞节点的安全路由协议。分析时延容忍传感器网络模型和黑洞攻击模型,给出基于传递证据的恶意节点检测方案,并将其与路由协议相融合。仿真结果表明,该协议可准确识别出恶意节点,并且在传感器网络环境中具有较好的路由性能。将安全路由协议应用于水下环境监测或城市交通控制等领域,可以避免其网络环境遭受恶意节点的攻击,保证网络的可靠性与稳定性。     

AODV自适应网关设计及仿真

Ad Hoc网络和有线网络的互联是网络发展的必然。为实现有线节点与无线节点间的通信,在采用AODV路由协议的Ad Hoc网络中通过添加网关节点的方式实现AODV协议无线网络的有线接入。在AODV路由协议中添加了网关节点,并结合实际网络场景进行了网关公告的自适应性能优化。对改进后的AODV路由协议在NS2中进行了仿真。仿真结果表明：实现了改进AODV协议无线节点与有线节点的通信,降低了网关引入的网络开销,可以灵活地响应网络拓扑变化。     

MANET环境下AODV协议的研究和改进

MANET网络就是移动Ad—Hoc网络，它是由若干节点所组成的一个移动自治系统，在一个无线Ad—Hoc网络中，节点之间通过多跳无线链路相互通信，所有的节点利用共享的无线媒质相互联系。这样节点之间路由问题就成为一个重点要解决的问题。目前，在这方面普遍采用DSR和AODV路由协议。但是，这两种路由协议对于要求QoS的网络来说还是力不从心的。文中主要讨论的是基于AODV路由协议的一些改进方案。     

基于多节点联合的Ad hoc网络攻击

本文基于对Ad hoc网络中AODV协议的安全性分析,针对现有黑洞攻击中存在的不足,提出一种新的基于多节点联合的跨层攻击方法。该方案可以破坏网络中正在传输的路径,迫使源节点重新发送路由请求,以达到恶意节点进入其路由路径,从而实施主动攻击的目的,而不必像传统的AODV路由攻击那样,需要等待节点发起路由请求才能实施攻击。     

无线Ad Hoc网络中AODV路由算法的改进研究

无线Ad Hoc网络是一个临时多跳的自治系统。网络中各节点地位平等,既可以做主机也可以做路由器。Ad Hoc网络有着广泛的应用,已成为当前研究的热点之一。由于Ad Hoc网络拓扑结构频繁变化,本文提出了一种改进的AODV路由协议——R_EAODV。R_EAODV路由协议通过查看每个节点的剩余能量进行链路修复。通过仿真我们发现R_EAOD在分组传送成功率、平均端到端时延、路由开销等性能方面都得到有效的改善,特别是当节点能量不足时进行链路修复以发现新的路由,更适用于拓扑结构变化快的网络环境。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。