面向高速场景的基于路径连通概率路由协议

有效地传输数据是提高车联网VANETs(Vehicular Ad Hoc Networks,)应用性能的关键.而动态的拓扑结构,给VANETs的数据传输提出了挑战.为此,提出基于路径连通概率的车联网路由算法CPR(Connected Probability-Based Routing).首先,依据高速公路场景,建立一维车辆移动模型,然后再计算链路的连通概率,最后,计算路径的连通概率,并选择连通概率最高的路径传输数据.仿真结果表明,提出的CPB算法能够有效地提高数据包传递率、端到端传输时延以及吞吐量性能.     

Ad Hoc网络多路径需求路由及路径熵选择算法

无线移动Ad Hoc网络是一种不依赖任何固定基础设施的移动无线多跳网络.由于其动态性和资源的限制,在Ad Hoc网络中提供多路径路由是一个重要的研究课题.描述了一种Ad Hoc网络中基于信息熵选择的稳定多路径路由算法(stability multipath on-demand routing,简称SMDR),提出了路径熵的度量参数,并利用路径熵来选择稳定的、长寿命的多路径,减少了重构路由的次数,从而在网络拓扑频繁变化的Ad Hoc网络环境中较好地提供QoS保证和提高数据传输率.仿真结果表明,SMDR协议改进了分组传输率、端到端时延和路由负载率.SMDR协议为解决动态的Ad Hoc网络多路径传输提供了一种新的有效途径.     

Ad Hoc网中基于熵的长寿分布式QoS路由算法

在分析Ad Hoc网的单播QoS路由问题的基础上,提出了一种新的Ad Hoc网的分布式QoS路由算法--EBLLD(entropy-based long-life distributed QoS routing)算法.其核心思想是提出了衡量路径稳定性的新尺度--熵,并利用熵来选择长寿的路径,减少了重建路由(或路由修复)的次数,从而在Ad Hoc网的网络拓扑频繁变化的环境中尽可能地提供QoS保证.同时该算法还利用本地组播机制和启发函数排序过滤和熵尺度排序过滤减小了其路由消息开销.仿真结果表明,EBLLD算法能够以较小的路由消息开销获得较高的路由成功率.此外,EBLLD算法具有可扩展性,可以应用于较大规模的Ad Hoc网中.     

移动Ad hoc网络路由协议的研究

介绍了当前Ad Hoc(移动自组网络)的网络路由协议研究现状,对Ad Hoc网络路由协议分类,并就传统的按需距离矢量路由(Ad-hoc On-Demand Distance Vector routing,AODV)的特征、优点和缺点给出分析,提出了一个新的基于AODV的改进路由协议--N-AODV(Neighborhood Routing Protocol based on AODV).采用NS-2系统仿真工具搭建了移动Ad Hoc网的仿真平台,在此平台的基础上,实现了N-AODV路由算法.通过仿真比较传统的AODV路由算法和改进的AODV路由算法的网络性能,验证了N-AODV算法的可行性,为实际系统的设计和规划提供了参考算法、参考模型和参考数据.最后,提出了一个基于Ad Hoc网络应用的系统架构.     

面向车载网的基于AODV优化路由协议的研究

车载网VANETs(Vehicular ad hoc networks)属于新型的通信模型,其可实现车间通信和车与基础设施通信。由于VANETs节点密度动态变化,节点的快速移动、移动模型的局限性等特点,为VANETs的数据传输提出挑战。鉴于此,提出优化的按需距离矢量AODV(Ad Hoc On demand Distance Vector)方案IAODV(Improved AODV)。在城市环境中,AODV在端到端传输时延、数据包丢失率方向性能较差。为此,IAODV采用限定源节点的路由跳数,降低AODV的端到端传输时延,同时为源节点提供备份路由,从而改善数据包丢失率。仿真结果表明,与AODV协议相比,IAODV在端到端传输时延、数据包丢失率得到有效提升。     

基于链路时间预测的移动Ad Hoc网路由

移动Ad Hoc网络是一种自组织、无基础设施的网络。而节点的自由移动促使链路频繁的断裂。为此,提出基于链路连通时间预测路由LDPR(Link Duration-Prediction-based Routing)。LDPR路由先通过节点运动信息,预测链路的连通时间。然后,再依据链路的连通时间计算路由生成时间,并选择两条路由生成时间长的路由协同传输数据,一条路由作为主路由,另一条路由作为备用路由。通过双路由机制,提高数据包的传输效率。实验数据表明,相比于传统的按需距离矢量AODV(Ad Hoc On-demand Distance Vector)路由,LDPR路由在吞吐量和端到端传输时延方面的性能得到有效改善。     

Ad Hoc网络中基于蚁群的多路径路由算法

Ad Hoc网络是由一组移动节点在没有任何现存网络基础设施或是集中管理的情况下形成的动态网络.针时Ad Hoc网络的动态网络环境和负载不均等不利因素,提出了一种基于蚁群的Ad Hoc多路径路由算法(AMRBA),算法具有良好的分布式特性,能为网络提供大量的冗余路径,增强了网络的抗毁性.同时通过对蚂蚁收集到的网络信息所对应的参数赋予不同加权值的方法对路由表进行控制,有效地缓解了Ad Hoc网络的拥塞问题和路由开销过大的问题.仿真结果表明,AMRBA在分组投递率、端到端平均时延等方面有优良性能,改善了网络性能.     

车联网中V2I通信路由的研究

节点移动和无线链路的衰落导致车联网 (Vehicular Ad Hoc Networks,VANETs)拓扑的快速变化。传统的路由通常依据移动参数(如位置、速度和方向)计算链路稳定性,而忽视信号的多径衰落,其降低了网络性能的。为此,提出面向Nakagmai衰落信道的车与路边设施通信 (Vehicles-to Roadside Infrastructure, V2I)通信路由(Nakagmai Fading Channel-based V2I Communication Routing, FCCR)。FCCR路由引用有效链路寿命作为新的路由指标,其考虑了移动参数和多径衰落信道统计值对链路稳定性的影响,目的在于使车辆能够选择具有最稳定、最小衰落连通路边设施(Road Side Units, RSUs)的路由。实验数据表明,提出的FCCR路由算法提高了吞吐量,并降低了开销     

基于萤火虫群优化的Ad Hoc网络路由协议

针对Ad Hoc网络拓扑结构多变、网络生存时间受限及数据包分组传输效率低下等问题,本文借鉴萤火虫群优化算法的思想,提出了一种基于萤火虫群优化的Ad Hoc网络路由协议。路由协议用萤火虫优化算法的荧光素强度的更新规则与无线自组网络中的节点移动速度、拥塞程度、节点剩余能量及节点间的距离等因素相互映射,改进萤火虫群优化算法中的搜索萤火虫、驻留萤火虫及回溯萤火虫用于完成Ad Hoc网络中路由协议的路由发现、路由选择及路由维护等过程,整个协议无须传送大量的控制分组,即可实现Ad Hoc网络的稳定。仿真实验结果表明,与AODV及基于蚁群优化的路由算法AntRouting协议相比,本文所提出的路由协议在端到端延时、分组数据传输率及网络生存时间上均有良好的性能。     

Ad Hoc网络路由重构技术研究

由于Ad Hoc网络的特点,从它出现就一直受到了各界的广泛关注,尤其是在军事领域中,得到了广泛的研究与应用。在一些特殊的军事应用中,节点的移动方向以及移动速度都与作战需求有很大的关系,这导致网络拓扑结构实时变化。而在战术Ad Hoc网络这样一个动态变化的网络中,怎么样提供更好的路由服务、确保信息及时准确的送达是一个迫切需要解决的问题。针对这个问题论文主要介绍Ad Hoc网络路由重构技术的特点和主要因素,并在原有路由重构算法的基础上提出一种基于路径跳数和带宽的最短路径路由选择算法,通过实验验证,该算法能在网络拓扑结构发生变化触发路由重构时,有效选择一条到达目的节点的新链路,从而保证战术Ad Hoc网络环境下,指挥作战信息的畅通传输。     

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。     

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.     

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.     

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。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.