一种多接口多信道VANET动态信道分配算法研究

为了合理地实现多接口多信道车载自组织网络（VANET）车辆节点间通信信道的动态分配,提出了一种基于通信双方车辆节点信道切换队列的动态信道分配算法。定义了车辆节点的射频接口状态,给出了信道的性能因子以及信道切换队列的生成方法,通过综合考虑通信双方车辆节点的射频接口状态和信道切换队列,快速自主地建立通信链路,从而解决了信道公平接入和分配不合理的问题。通过软件仿真比较可以看出,该算法实现了信道的动态分配,减小了平均端到端时延,增加了网络平均吞吐量,显著提高了多接口多信道VANET的网络性能。     

基于多接口状态字的VANET信道接入算法研究

为了实现多接口车载自组织网络(VANET)车辆节点合理高效的信道接入,提出了一种基于车辆节点多接口状态字的时分竞争信道接入算法。根据车辆节点的多接口状态字给出了时隙划分的方法与竞争退避机制原则,通过综合考虑竞争类技术与时分多址技术的优点,有效解决了信道公平接入的问题。通过软件仿真比较可以看出,该算法实现了信道的合理接入,减小了平均端到端时延,增加了网络平均吞吐量,显著提高了多接口VANET的网络性能。     

多接口车载自组织网络频谱分配算法研究

如何提升链路的并行传输能力是车载自组网面临的重要问题.如果在车辆上装配多个无线接口,并且分别调制到不同的正交信道可以有效增强链路的并行传输能力,从而提升网络吞吐率.针对拓扑变化对多接口车载自组网动态频谱分配带来的影响,提出了一种多接口车载自组网动态频谱分配算法.算法根据车辆的运动速度进行分簇,然后在簇头间通信中采用离线频谱分配策略,从而避免了网络的拓扑变化对频谱分配造成的影响.而簇内车辆具有相同的运动速度,所以具有稳定的簇内拓扑结构,有利于频谱分配算法的应用.仿真分析表明,提出的算法适用于多接口车载自组网,在动态拓扑环境下表现出了良好的性能.     

多信道无线Mesh网络的多播信道分配算法

无线Mesh网络可用信道和节点接口的缺乏限制了多播树链路的可用带宽,致使网络吞吐量下降。针对该问题,提出支持多播的多信道多接口信道分配算法——LAMCA。该算法能最小化无线Mesh网络的干扰程度,并最大化网络吞吐量。仿真结果表明,与层次信道分配算法LCA相比,该算法在吞吐量性能方面较优。     

基于SAC强化学习的车联网频谱资源动态分配

针对车联网频谱资源稀缺问题,提出一种基于柔性致动-评价（SAC）强化学习算法的多智能体频谱资源动态分配方案。以最大化信道总容量与载荷成功交付率为目标,建立车辆-车辆（V2V）链路频谱资源分配模型。将每条V2V链路作为单个智能体,构建多智能体马尔科夫决策过程模型。利用SAC强化学习算法设计神经网络,通过最大化熵与累计奖励和以训练智能体,使得V2V链路经过不断学习优化频谱资源分配。仿真结果表明,与基于深度Q网络和深度确定性策略梯度的频谱资源分配方案相比,该方案可以更高效地完成车联网链路之间的频谱共享任务,且信道传输速率和载荷成功交付率更高。     

一种异构多接口多信道无线网络的信道分配算法

多接口多信道技术是无线网络环境中减少链路干扰、提高网络吞吐量的有效途径,但如何合理有效地进行信道分配已成为多接口多信道无线网络所面临的主要问题之一.针对自私的网络节点,本文使用非合作博弈对异构条件下多接口节点的信道分配问题进行建模分析,其纳什均衡解为解决该问题所需的稳定的信道分配方案.本文首先讨论纳什均衡的存在条件并提出实现纳什均衡的分布式算法.此外,考虑到实际网络中节点仅能感知局部信道信息以及接口工作信道受限等因素,本文进一步改进算法并通过仿真实验对其收敛性进行证明.     

多跳多接口无线网络中的协作路由

协作通信可以利用空间分集效应抵抗无线信道衰弱而得到广泛关注。在多业务流多跳多接口无线协作网络中,研究联合路由选择和协作节点分配的最优化问题,将最大化最小业务流速率的联合优化问题建模为混合整数线性规划问题。针对这个问题提出一种基于分支定界的启发式算法JFRBB。JFRBB算法基于分支定界的思想是将原问题分解为多个子问题通过迭代获得最优解。仿真实验结果表明,JFRBB下的多接口协作网络获得的传输速率、聚合流量明显优于多接口无协作网络和单接口协作网络的性能。     

一种基于多接口多信道的移动Ad Hoc网络仿真平台实现方法

目前移动Ad Hoc网络的研究主要针对单接口单信道场景,但随着底层无线技术的进步和发展,一个节点往往可以具备多个接口,并且可以配置不同的信道。新的特性使得针对移动Ad Hoc网络的研究有了新的网络支撑环境。针对现有的NS-2环境下单接口单信道模型的不足,提出具有多接口多信道特性的移动Ad Hoc网络仿真平台的一种实现方法。实验结果验证了多接口多信道平台设计的正确性。该仿真平台的实现,使得多接口多信道环境下的移动Ad Hoc网络性能评估成为可能,并且能够方便对新研发协议进行测试。     

基于分组管理的无线mesh网多信道分配算法*

为了合理利用多信道来提高无线网络吞吐量,针对基于802.11标准无线mesh网的业务特点,提出了基于分组管理的分布式多信道分配算法。该算法将节点接口分为回程接口与转发接口,并使回程接口分配到在干扰区域内干扰值尽可能小的信道。仿真实验结果表明,该算法可以减少区域干扰,并可充分利用信道的多样性和得到较高的网络吞吐量。     

一种多射频多信道分配算法的研究与仿真

随着无线Mesh网络的发展,在网络中配置节点多射频多信道,提高信道资源的利用率和降低无线干扰,成为扩大网络容量的有效手段.采用了一种基于网络拓扑信息的集中式的多射频多信道分配算法.实现包括信道分配计算、信道分配切换及网络恢复三个阶段.三个阶段依次实现网络的信道干扰最小、确保网络的连通以及节点失败后网络的恢复,并提高网络的容量.仿真结果表明,信道分配算法可以有效地提升网络性能.     

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.     

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     

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.     

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.