无线多媒体传感器网络能量敏感多路径路由

针对节点能量分布不均匀的无线多媒体传感器网络中大数据量传输问题,提出一种无线多媒体传感器网络能量敏感多路径路由算法EACM。该算法通过平衡路由节点间剩余能量差异,调节多路径聚集程度来均衡网络能耗减少数据包在路径上的延迟。仿真结果表明EACM算法能有效地延长网络生存期,减少数据包在路径上的时延。     

无线传感网络数据转发最佳权重选取算法仿真

为了有效提高无线传感网络数据转发的有效性和可靠性,针对传统的数据转发算法存在的数据转发率低、延时长等问题,提出一种基于蚁群优化的无线传感网络数据转发最佳权重选取算法。选择无线传感网络数据节点负载、剩余能量以及数据转发时延作为网络服务性能评价指标,利用熵权系数法自适应地确定评价指标的权重。引入数据转发链路容量和链路距离等因素建立数据转发时延最小的优化模型,利用蚁群算法的节点概率函数机制找出能同时满足时延带宽和数据转发链路容量要求的评价值最高的邻居节点,通过上述节点选取数据转发最优权重,完成数据转发。实验结果表明,所提算法在节点能量消耗、转发延迟、数据转发率等方面都优于现有无线传感网络数据转发算法。     

基于能量的无线传感器网络拓扑发现算法改进

对于自组织的无线传感器网络而言,网络拓扑控制对网络性能影响很大。良好的拓扑结构能够提高路由协议和MAC协议的效率,为数据融合、时间同步和目标定位等很多方面提供基础,有利于延长整个网络的生存时间。本文提出了一种基于能量因素的无线传感器网络拓扑发现算法,该算法是以TopDisc算法为基础,在此基础上考虑根据节点的剩余能量控制等待转发时间,在响应拓扑发现请求时把节点自身的剩余能量考虑在内,与距离加权后影响邻节点的发送时延,即对算法的时延机制进行改进。     

基于剩余能量预测的WSN模糊分簇算法

为了进一步降低无线传感器网络的能量消耗,延长网络寿命,提出一种基于剩余能量预测的无线传感器网络模糊分簇算法。新算法根据节点到基站的距离和邻居节点的数目,对候选节点转发数据的能耗进行预估,得到节点的预测剩余能量。然后采用模糊算法在综合考虑候选节点的原始能量和预测剩余能量的基础上计算竞争半径,选出多个簇首,构建大小不均的簇。仿真实验表明,与其他路由算法相比,该算法可以更好地优化簇的结构,均衡网络能耗,延长网络的生命周期。     

一种基于模糊逻辑的自适应信标交换算法

针对移动无线传感器网络中贪婪地理路由协议采用固定信标周期导致通信暂盲的问题,提出了一种基于模糊逻辑的自适应信标交换算法。该算法以节点移动速度、节点剩余能量和邻居节点的数量作为评价因素,利用模糊逻辑控制机制确定自适应的信标周期,提高了邻居表构建与维护的准确性与实时性,为贪婪地理转发提供了可靠依据。仿真结果表明：该算法有效减少了通信暂盲现象,降低了控制开销和平均端到端时延,提高了分组交付率,适用于对传输可靠性要求高的大规模移动无线传感器网络。     

基于蚁群系统的WSN能量均衡多路径路由协议

针对无线传感器网络节点能量有限和网络拥塞问题,采用一种基于蚁群系统的能量均衡多路径路由协议。在路由发现过程中,综合考虑节点最小剩余能量和平均剩余能量,通过跨层设计模型获取节点距离信息和节点队列长度作为启发式函数,利用蚁群系统的特点形成多路径的数据传输。仿真结果表明,该路由协议在端到端传输时延和能量均衡等方面优于其它协议。     

基于蚁群优化算法的ReInForM动态路由

无线传感器网络中Re In For M多路径协议能保证网络可靠性,但未考虑节点能量动态变化和通信路径工况,随机选取下一跳转发节点的方式使得部分节点因被反复使用而快速失效,缩短了网络生命周期。针对该问题,在蚁群优化算法的基础上,结合蚁群信息素浓度和节点剩余能量等因素,提出一种Re In For M协议多目标优化条件下的动态路由选择算法,将能耗和剩余能量作为多路径选择指标,共同决定下一跳最优节点。仿真结果表明,与原有Re In For M路由算法相比,该算法能够在保证数据传输可靠率的同时,更有效地均衡节点能耗。     

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。     

基于蚁群优化的无线传感器网络能耗均衡路由算法

针对无线传感器网络中节点能量受限的特点,将蚁群优化算法(ACO)应用于无线传感器网络,同时考虑了通信路径长度和节点剩余能量等因素,提出了具有能量意识的无线传感器网络路由算法,从多方面解决了节点间的能耗不均衡问题。该算法在OMNET++平台下仿真结果表明,与Ant-Net、ACRA算法相比在能耗不均衡和传输延迟等方面有了较大改进,实现了全网节点的能耗均衡,有效延长了网络生命期,减小了传输时延。     

改进的异构无线传感器网络路由能量算法

阈值稳定选举协议（Threshold-Stable Election Protocol,TSEP）没有考虑节点的剩余能量和节点到基站的距离,导致部分低能量节点当选簇头而过早死亡。而且簇头将数据直接发送给基站,也导致节点能量耗尽而过早死亡。针对以上问题,提出了一种改进的异构无线传感器网络节能路由算法。新算法通过考虑节点到基站的距离、节点的邻居节点数、节点的剩余能量以及节点与邻居节点的平均距离来改进阈值公式,通过改进的蚁群算法对双层簇头模型的数据转发路径进行优化。仿真结果表明,该算法延长了网络的生命周期,提高了整个网络的稳定性。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.