基于概率度分簇的ad hoc网络实时多媒体通信方案

Ad hoc网络的移动性、高度动态拓扑使得实时多媒体传输受到严重影响，为了解决多媒体通信中的传输不稳定和丢包问题，应用Markov过程提出了基于概率度的分簇算法（PD）。该算法首先在当前时刻预测下一时刻任意两点间链路的连通性，然后选取链路的连通概率较高的节点作为簇头。仿真结果表明，PD算法成簇数目少于最高连通度算法（HD），而且簇内节点无重叠，从而有效降低了分簇结构的维护开销。由于簇成员数量并不明显多于HD，因此说明PD算法效率较高，而且没因分簇数目减少给簇首增加负担。最后在此分簇基础上，结合UDP协议，给出了一种基于概率度分簇的ad hoc网络实时多媒体通信方案，不仅使得传输稳定，而且解决了数据包失序和丢包问题。     

无线传感器网络分簇拓扑的覆盖区域节点调度优化算法研究

利用区域分割的方法建立了一种覆盖区域冗余节点的优化调度机制,实现对完全覆盖区域内冗余节点的休眠调度,并将该机制引入无线传感器网络的分簇结构中,提出一种基于分簇拓扑的节点调度优化算法。算法通过控制簇内冗余节点进行休眠,减少簇首的数据通信量和簇成员中工作的冗余节点个数,降低了网络能耗。仿真结果表明,与未考虑冗余节点休眠调度的分簇算法相比,该算法有效提高了网络能量利用率,延长了网络生命期。     

无线传感器网络的连通成簇算法

在大规模无线传感器网络中,层次型拓扑可有效地提高节点的能量效率,延长网络的生存时间.本文提出一种基于连通支配集的分布式分簇算法,利用剩余能量较优的节点来担任簇头的角色,使整个网络的能量均衡消耗;在簇内与簇间通信能力相同情况下,使所有的簇头节点构成一个连通子网,以简化簇间通信的约束条件,提高簇间通信的能量效率;模拟实验表明算法的可行性以及有效性,能进一步延长网络的生存时间,可应用于无线传感器网络的层次型拓扑控制.     

能量优化的无线传感器网络LEACH算法

针对无线传感器网络(WSNs)的经典路由算法LEACH中存在簇头节点选举不合理,导致节点加速死亡、网络寿命缩短的问题,提出了基于能量和连通度的LEACH(LEACH-EC)算法.该算法主要在簇头选举时,同时引入节点的剩余能量和连通度两个因子,采用修改阈值的方法,优化簇头选举,从而避免低能量和低连通度节点担任簇头的可能性.仿真实验结果表明:该算法均衡了整个网络能量消耗的比例,延长了节点和网络的寿命.     

低概率事件场景的无线传感器网络构建

低概率事件场景,静态部署的小规模监测网络是较为常见的一类无线传感器应用网络.针对这一类无线传感器网络的特点,从拓扑控制角度出发,基于分层分簇思想,提出了一种固定分簇层次型网络构建方法.该方法采用固定分簇有效节省了一般周期性动态分簇聚类大量能耗,簇内成员节点基于事件概率预测的休眠调度更进一步降低了网络能耗;簇头在簇内的轮换实现了网络能耗均衡;功率控制建立了可靠的多跳路由.仿真性能分析表明:该方法节能效果明显,实施简单,易于应用推广.     

基于IK-means聚类的分簇路由算法

为了均衡移动自组织网络的能耗,提高簇结构稳定性,提出了一种基于IK-means聚类的分簇路由算法(IK-CRA).首先利用IK-means算法对网络中的节点进行分簇;然后通过节点的剩余能量、邻居节点数与连通代价的比值、链路维持时间构造适应度函数,采用改进的人工蜂群算法(IABC)解决分簇路由算法中的最优簇头问题.仿真结果表明,IK-CRA算法缩短了成簇时间,降低了节点的状态变化率,减少了节点的能量消耗,延长了簇首的持续时间,提高了动态环境下簇结构的稳定性.     

无线传感器网络拓扑三级分簇优化算法

针对大规模分布式传感器网络提出一种拓扑三级分簇结构优化算法. 通过引入传感器休眠模式, 并考虑到分簇数目较多的情况, 对多个簇头节点采用生成最小刚性图的方法进行拓扑优化, 以实现传感器网络整体能量均衡,使传感器网络具有较好的连通性和鲁棒性. 仿真实验表明, 与已有相关算法相比, 采用所提出的算法可使网络延缓出现节点死亡现象, 有利于实现网络负载均衡, 并且网络中节点整体存活时间较长, 从而延长网络的生命周期.

     

模糊边缘检测无线传感器网络分簇算法

针对传统分簇算法簇头选举仅单一考虑节点位置或能量分布的问题,提出了一种基于模糊边缘检测的无线传感网络分簇算法,该算法综合考虑拓扑边缘信息和节点能量分布,根据网络能量分布情况调整带宽内边缘节点参与簇头选举的概率.仿真结果表明,该算法簇头选举相对于LEACH算法分布更加合理,有效延长网络生命周期.     

SEBCDS:无线传感网络的连通支配集算法

由于无线传感网络(WSN,sireless sensor network)节点受到能量和传输距离的约束,有效地构建连通支配集(CDS,connected dominating set)是提高WSN数据传输效率的重要技术手段.然而,现存的多数构建CDS算法只强调CDS规模,没有考虑网络的能量均衡.为此,提出了基于休眠机制和能量均衡的连通支配集(SEBCDS,sleep-and energy-balance-based connected dominating set)算法.SEBCDS算法首先选择剩余能量高和邻居节点多的节点作为支配节点,并为支配节点选择副支配节点,然后采用休眠机制,让一部分支配节点工作,另一部分支配节点休眠,降低网络能量消耗.仿真结果表明,提出的SEB-CDS算法能够降低能量消耗、延长CDS的生命周期.与TCDS算法相比,能量消耗降低了23％,CDS的生命周期提高了约31%.     

基于最高连接度的WSN交叠分簇算法

本文对无线传感器网络的分簇算法进行了研究,提出了一种分簇算法.该算法将网络分成若干个相互交叠的簇,从而产生网关节点,并利用连通支配集理论优化网络的拓扑结构,选取剩余能量值高的网关节点成为支配节点作为,均衡了网络的负栽和能量消耗,达到了延长网络生命时间的目的.     

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.