WSN中基于最大最小化的优化路由算法

无线传感器网络(WSN)由能量受限的节点组成,需要设计路由算法优化节点的能耗。文章以最大化网络生存时间为目标,基于最大最小化模型提出了优化路由算法,定义了数据发送矩阵,设计了转发节点选择机制,以避免路由回路;基于节点收发数据的能耗及剩余能量,设计了求解优化路由的数学规划模型,优化了传感器节点的数据发送路径和发送量,均衡了节点的能量消耗。仿真结果表明,该算法能有效地均衡节点的能耗,延长网络生存时间。     

基于改进蚁群算法的无线传感网络路由算法研究

针对无线传感网络能量消耗不均及节点过早死亡等问题,提出一种新的基于改进蚁群算法的路由算法。在网络结构方面,加入网络分隔带和搜索角,并结合节点剩余能量,共同限制下一跳节点的转移概率;同时改进启发函数,加入能量影响因子,增强算法寻优,避免陷入局部最优;在信息素更新方面,引入阈值机制并设立最优路径权重值来寻找最优路径。仿真结果表明,改进后的算法能够进一步降低网络能耗,延长网络生命周期。     

基于蚁群的无线传感器网络能量均衡非均匀分簇路由算法

无线传感器网络(WSN)路由中,节点未充分考虑路径剩余能量及链路状况进行的路由会造成网络中部分节点网络寿命减少,严重影响网络的生存时间。为此,将蚁群优化算法与非均匀分簇路由算法相结合,提出一种基于蚁群优化算法的无线传感器非均匀分簇路由算法。该算法首先利用考虑节点能量的优化非均匀分簇方法对节点进行分簇,然后以需要传输数据的节点为源节点,汇聚节点为目标节点,利用蚁群优化算法进行多路径搜索,搜索过程充分考虑了路径传输能耗、路径最小剩余能量、传输距离和跳数、所选链路的时延和带宽等因素,最后选出满足条件的多条最优路径,完成源目的节点间的信息传输。实验表明,该算法充分考虑路径传输能耗和路径最小剩余能量、传输跳数及传输距离,能有效延长无线传感器网络的生存期。     

基于蚁群优化的WSN功率自适应路由算法

为节省节点能量开销,延长无线传感器网络(WSN)的生命周期,在研究蚁群优化算法的基础上,提出一种基于蚁群优化的功率自适应路由算法。在蚂蚁寻路时考虑节点的传输方向、剩余能量和节点间距离。寻找到一条最优路径后,根据相邻两节点间的距离调整节点的发射功率,避免功率过大造成能量浪费。仿真实验结果表明,在节点非均匀分布的情况下,该算法能够有效节省网络开销,延长网络生命周期。     

基于蚁群算法的WSN多路径负载均衡路由

为使无线传感器网络节点能量消耗相对均衡,在定向扩散路由算法的基础上,结合蚁群算法,提出一种多路径负载均衡路由算法。该算法利用蚁群的自适应和动态寻优能力,在源节点和目的节点之间搜索建立多条传输路径,并将节点剩余能量引入启发因子,均衡节点能量消耗。同时,运用层次分析法,赋予每条路径一定的负载分配比例,使数据总能在链路性能较优的多路径中均衡传输,延长整个网络的生命期。仿真结果表明,与定向扩散路由算法相比,该算法能够均衡节点能耗,有效延长网络寿命。     

基于改进蚁群优化算法的无线传感器网络路由研究

无线传感器网络为能量受限系统,为了促使网络节点能量消耗相对均衡,将蚁群优化(ACO)算法应用于无线传感器网络的路由选择,提出一种基于能量均衡的无线传感器网络路由算法。该算法将节点能量作为转移概率规则启发因子,通过计算转移概率和适应度值找到最优路径。仿真结果表明:该算法可以显著减低网络总能耗,从而延长无线传感器网络的生命周期。     

基于聚类分析的能耗均衡无线传感器网络分簇算法

为降低并均衡无线传感器网络(WSN)中传感器节点的能量消耗,提出一种基于最优传输距离和K-means聚类的WSN分簇算法。根据层次聚类算法建立聚类特征树,将聚类特征树中的叶节点视为一个簇,并使每个簇控制在最优传输距离内,实现簇内节点的能耗均衡。通过目标函数对K-means聚类簇进行优化,保证簇内节点数目的均匀分布,并在考虑剩余能量和地理位置的基础上完成节点数据传输。实验结果表明,该算法在均衡网络能耗的同时,可有效延长网络生命周期。     

一种基于分簇蚁群策略的无线传感器网络路由算法

如何最大化地延长网络的生存时间是无线传感器（WSN）网络研究的核心问题.基于分簇策略,提出一种能量有效的路由算法（EEA）.该算法利用分簇原理减少了参与寻找最优路径的节点数,从而降低了系统的能耗.同时设计一种改进的最优路径评价标准,该标准兼顾了传输路径上各节点的剩余能量和最优路径上总的能量消耗.仿真结果表明,与其他蚁群策略的路由算法（如：基于蚁群算法的路由算法（ARA）和EEAWSN）相比,该算法能在寻找最优路径时避开剩余能量少的节点,使最优路径上各节点的能量呈整体性衰落,从而沿长了网络的寿命.     

采用半贪心优化的节点非均匀分布路由协议

为避免无线传感器网络中因节点能耗不均衡而产生的能量空洞现象,延长网络生命周期,提出采用半贪心优化的节点非均匀分布路由协议。首先在网络监测区域分层的基础上,计算各层感知数据转发能耗,根据各层网络能耗比例和监测区域覆盖要求,设计了密度递减的节点部署模型;然后基于两跳通信的贪心范围,提出两跳能耗代价估计函数,改进半贪心算法;在簇间多跳通信阶段,利用优化的半贪心算法求解簇头到基站的最优转发路径。仿真实验表明,与现有的几种路由协议相比,新协议能够均衡各层网络节点能耗,延长网络生命周期,有效避免能量空洞现象。     

基于改进蚁群算法的LEACH协议研究

针对LEACH协议在数据传输阶段,簇首与汇聚节点之间采用单跳模式传输数据使得能量消耗快并且不均衡的问题,提出一种基于改进蚁群算法的新型路由协议。该协议利用了能耗因子对蚁群转移概率以及信息素更新进行改进,充分考虑了节点的剩余能量和节点间距离,通过信息素的建立和更新,寻找簇首节点和基站之间的最优传输路径,进行多跳传输模式,从而均衡簇首节点能量消耗。仿真实验结果表明,改进后的ACO-BEC协议较之于LEACH协议,能够有效降低了整个网络能量消耗,延长了网络寿命。     

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。     

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。