基于虚拟移动的IPv6主动防御方案

现有通过地址跳变对IPv6节点进行防护的技术依赖时间同步或事件同步,利用IPv6的良好移动特性和多转交地址注册机制,提出一种基于虚拟移动的IPv6主动防御方案。通过为IPv6节点分配动态变化的转交地址,使其呈现出在网络内不断移动的特征,降低攻击者对其实施攻击概率的同时,能够保证通信的持续。理论分析和实验测试表明,方案具有良好的抗攻击能力且较小的系统开销。     

基于滑动时间窗口的IPv6地址跳变主动防御模型

针对IPv6恢复端到端通信,IPv6节点易被攻击者探测攻击等问题,提出一种基于滑动时间窗口的IPv6地址跳变（AHSTW）主动防御模型。首先通过共享密钥进行地址跳变间隔等会话参数的协商,之后引入收发时间窗口的概念,通信双方仅发送或接收处于时间窗口内的数据包,通过时间窗口自适应调整（TWAA）算法,依据网络时延的变化及时调整时间窗口大小以适应网络环境的变化。理论分析证明,该模型能够有效抵抗攻击者对目标IPv6节点的数据截获分析攻击和拒绝服务攻击（DoS）。实验结果表明,在传输相同数据包大小时,AHSTW的额外CPU开销在2~5个百分点,并无显著提高,通信效率并无显著下降;在通信过程中,通信双方地址与端口呈随机、分散、无序等特点,极大增加了攻击者的开销与攻击难度,保护了IPv6网络安全。     

一种基于IPv6安全通信方案的移动扩展研究

在对基于固定IPv6网路的安全通信方案进行研究和分析的基础上,提出了一种新的基于移动IPv6网络的安全通信扩展方案.通过对固定IPv6网络中的基于亲密伙伴的安全通信方案进行改进,并结合移动IPv6网络中移动节点的特性,提出了一种动态构建安全通信管理模式的新思想.以移动子网内部移动节点的预测驻留时间为标准来选取子网内部的管理节点.通过在移动网络中构造一个动态管理节点,妥善地解决了原方案在移动IPv6网络中的扩展问题.最后,通过对新方案进行了仿真和分析,证明了该方案的可行性.     

移动IPV6越区切换管理模型的研究

移动IPv6为IPv6节点提供了在Internet中使用固定的家乡地址在不同子网中进行漫游通信的能力,然而当节点在网络间越区切换的时候,容易引起通信质量的下降或中断。针对标准移动IPv6和HMIPv6（层次化移动IPv6管理模型）对节点切换管理的不足,提出了一种新的越区切换管理模型方案,通过非固定的移动锚节点（MAP,Mobility Anchor Point）管理域,以及动态的MAP切换时机的选择,来达到降低切换行为的发生频率、保持切换发生时通信的连续性、使MAP负载均衡等目的。     

移动IPv6环境下的QoS机制研究

移动IPv6为IPv6节点提供了在Internet不同子网中使用不变的家乡地址进行漫游通信的能力。相比于传统固定网络,节点的移动为通信的服务质量(QoS)保证提出了新的挑战。介绍了当前的移动IPv6技术和IP网的QoS技术,并针对移动IPv6的特点阐述了其QoS机制,对比各种机制的特点,对其进行网络时延的分析。最后说明了移动IPv6的QoS需要解决的问题。     

移动IPv6环境下的QoS机制研究

移动IPv6为IPv6节点提供了在Internet不同子网中使用不变的家乡地址进行漫游通信的能力。相比于传统固定网络，节点的移动为通信的服务质量（QoS）保证提出了新的挑战。介绍了当前的移动IPv6技术和IP网的QoS技术，并针对移动IPv6的特点阐述了其QoS机制，对比各种机制的特点，对其进行网络时延的分析。最后说明了移动IPv6的QoS需要解决的问题。     

基于真实IPv6源地址的网络接入认证技术研究

提出了一种新的基于真实IPv6源地址的网络安全接入认证方法.此方法在IPv6无状态地址自动配置过程中加入802.1X认证技术,只有经过授权的节点才能获得IPv6全局地址,同时改进了802.1X认证流程,使管理者可以主动获得节点用户的全局IPv6地址.该方法既保留了IPv6"即插即用"的优点,又从源头上保证接入网络的安全性.     

基于F-HMIPv6的MAP自适应选择算法

移动IPv6提供了移动节点在不同子网中漫游通信的能力,同时为了缩短切换延迟和减少丢包率,层次化移动IPv6模型、快速切换机制及F-HMIPv6相继被提出.在层次化移动IPv6模型和F-HMIPv6中引入了MAP来缩短绑定更新延迟,但目前还没有较完善的MAP选择算法被提出.提出了一种自适应的MAP选择算法,该算法能根据移动节点的移动特点来选择合适的MAP.     

基于移动IPv6的选播路由协议研究

提出了一个简洁的基于IPv6的报文结构模型，该模型通过对现有IPv6中ICMP路由器发现报文的改进，实现了对网络性能的改善。在该模型中，移动节点到达一个新的子网时，获得转交地址和申请选播服务的实现不必经过以往的两次报文发送—接收过程，而只需一次。该模型对网络性能的改善体现在：缩短转交地址获得和选播服务确定的时间，简化ICMP报文的类型，节约网络带宽资源。     

面向IPv6物联子网的轻量级树型转发模型

在IPv6 物联网中,RPL 路由模型已得到广泛的认可.然而对于规模较大的多跳网络结构,RPL 面临着部分转发节点路由容量较大的问题.而且物联子网中扁平化的地址结构使得这一问题更为突出.设计了支持IPv6 地址自动分配的轻量级树型转发模型TFAD（tree forwarding model with address automatically distributed）,将物联子网中的节点构造成一棵层次转发树,树节点的IPv6 地址在子树范围内高度聚合.各节点只需存储与其子节点数相当的转发项,即可完成TFAD 模型的数据转发.此外,设计了TFAD 模型的备份父节点机制,当网络出现故障时能够以子树为单位进行网络拓扑重构,实现物联子网的快速路由恢复.实验验证了TFAD 模型的高效路由存储性能以及快速的路由学习能力和故障后路由恢复能力.     

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。