扰动粒子群优化的SDWSN路由算法

针对分布式路由算法在软件定义无线传感器网络中应用时能量消耗大以及簇头能耗不均衡问题,提出一种基于扰动粒子群优化的能耗均衡路由算法tPSOEB。该算法通过考虑节点的剩余能量、位置和能量均衡信息选择簇头,并引入扰动改进粒子群算法的搜索性能,然后用非均匀分簇的思想来构建大小不等的簇,每周期进行一轮全局分簇和[k]轮局部簇头更新,节省分簇时的能量消耗。在簇间路由建立时,根据链路能耗、节点剩余能量和簇内节点数,采用集中式方式构建最短路由树。仿真结果表明,tPSOEB能显著提高网络的能量使用率,延长网络寿命。     

基于差分算法的无线传感器网络路由分簇协议

针对异构无线传感器网络分簇路由协议存在节点能耗不均衡问题,提出一种基于差分进化算法的路由协议及基于节点能耗的分簇协议。该协议首先以最大化网络中簇头节点的最小生存周期为目标,建立函数优化模型,并采用差分进化算法对其进行优化,从而延长网络整体的生存周期;然后根据节点通信列表中的簇头数目进行分簇,将节点分配给能耗因子较低的簇头,以达到均衡网络能耗的目的,延长普通节点的生存周期。仿真结果表明,基于差分的路由分簇协议能有效均衡网络中节点的能量消耗,显著延长网络的生存周期并提高网络能量利用率。     

基于博弈论能耗均衡的WSN非均匀分簇路由协议

在无线传感器网络(WSN)的分簇路由算法中,节点间能耗不均容易引发 “能量空洞”现象,影响整个网络的性能。针对这个问题,提出了一种基于博弈论能耗均衡的非均匀分簇路由(GBUC)算法。该算法在分簇阶段,采用非均匀分簇结构,簇的半径由簇头到汇聚节点的距离和剩余能量共同决定,通过调节簇头在簇内通信的能耗和转发数据的能耗来达到能耗的均衡;在簇间通信阶段,通过建立一个以节点剩余能量和链路可靠度为效益函数的博弈模型,利用其纳什均衡的解来寻找联合能耗均衡、链路可靠性的最优传输路径,从而提高网络性能。仿真结果表明:与能量高效的非均匀分簇(EEUC)算法和非均匀分簇节能路由(UCEER)算法相比,GBUC算法在均衡节点能耗、延长网络生命周期等性能方面有显著的提高。     

压缩感知的能量异构WSN分簇路由协议

分簇路由协议对用于环境监测的无线传感器网络具有较好的节能性,数据压缩可以减少节点通信的数据量,但增加了分簇层次结构簇头的能耗和汇聚节点算法的复杂度,而由高能力节点担任簇头可以实现能量均衡并改善网络性能。针对无线传感器网络能量异构普遍存在的特点,提出了一种基于压缩感知的能量异构分簇路由协议（CSCH算法）。该算法根据异构节点能量确定多极簇头选举的概率,将簇内节点的信息集中在簇头上,而簇头对所采集的数据进行稀疏、压缩,以减少向汇聚节点传输数据的节点数和通信量,汇聚节点利用重构算法可从来自簇头的少量数据中恢复出信号源。同时设计了一种基于正态分布的权值系数,以优化在数据量过少情况下压缩感知算法的信号重构性能。仿真实验结果表明,该协议不仅能充分利用能量异构资源,均衡网络能耗,延长整个网络生命周期,而且能精确恢复信号源。     

带有重叠区域的多跳非均匀分簇路由算法

能耗作为衡量无线传感器网络性能的一项重要指标,通常将延长生命周期、均衡能耗作为网络协议重要的设计目标.针对静态、异构、非均匀分布的网络模型,设计带有重叠区域的分簇及簇内单跳、簇间多跳的路由算法 ----- OMU分簇路由算法,该算法中簇头不再作为数据转发节点,而主要用于簇内数据的接收与融合.通过综合考虑节点剩余能量、节点密度及与基站的距离进行簇头选举并进行分簇,形成簇间重叠区域,产生用于数据转发的中继节点.同时,建立簇头与中继节点轮换机制以达到节点能耗均衡的目的,并为每个节点建立能量最省的多跳数据传输路径.仿真结果表明,所设计的分簇路由算法,特别是在大规模部署的无线传感器网络中,能有效减少和均衡能量消耗.     

无线传感器网络中基于压缩感知的分簇数据收集算法

针对无线传感器网络(WSNs)能量有限、通信链路不可靠的特点,提出一种基于稀疏分块对角矩阵进行压缩感知的分簇(SBDMC)数据收集算法.该算法以稀疏分块对角矩阵作为观测矩阵以减少参与收集节点数目;采用分布式分簇路由实现数据的分布式收集;通过分析能耗模型得到最优簇头数目以减少网络能耗.在此基础上,给出一种有效的分簇路由数据收集算法.仿真分析表明:提出的算法较之已有算法可以减少通信能耗、延长网络寿命,同时均衡能耗负载.     

基于环的节点非均匀分布分簇算法

针对无线传感器网络（WSN）中基于环的节点非均匀分布网络模型下的能量空洞问题,提出了一种基于环的节点非均匀分布分簇算法（RCANND）。该算法在节点非均匀分布的网络模型下,通过每环的能耗最小化,计算每一环的最优簇首数;通过节点剩余能量、距基站距离以及与邻居节点的平均距离计算簇首选择度。在簇内以簇首选择度序列表进行簇首轮转,降低分簇次数,提高网络能量的利用效率。对提出的算法进行仿真对比实验,仿真结果表明,相同半径、不同分布模型下节点的平均能耗波动很小;相同分布模型、不同半径下节点的平均能耗波动也不明显。以网络中50%节点存活作为网络生命周期,在节点非均匀分布情况下,所提算法的网络生命周期比混合能量高效分布式不等分簇算法（UHEED）和轮转的混合能量高效分布式不等分簇算法（RUHEED）分别提高约18.1%和11.5%;在节点均匀分布模型下,所提算法的网络生命周期比基于分环的能量高效无线传感器网络分簇路由（RECR）协议提高约6.4%。所提算法有效均衡了不同分布模型下的能耗,有效延长了网络生命周期。     

基于环的能耗均衡分簇路由算法

针对无线传感器网络分簇路由算法中节点能耗不均的问题,提出了一种基于环的能耗均衡分簇路由算法。算法对监测区域作基于环的分簇,在靠近基站的“热区”内划定数据汇聚区,汇聚区内的节点不分簇,节省分簇及簇内通信能耗;对汇聚区外其他环的簇个数进行优化以均衡能耗。提出新的最优路径搜索策略,寻找整体最优路径,进一步减少网络能耗。仿真结果表明,提出的算法在能耗均衡性上比改进的LEACH路由协议(LEACH-R)和一种能量高效的非均匀分簇算法(EUCA)更优;以50%节点死亡作为网络生命周期,网络寿命分别提高约30.9%和11.9%,有效延长了网络生命周期。     

基于环分块的能耗均衡分簇路由算法

针对无线传感器网络（WSN）中节点能耗不均衡和能量效率低而影响网络生命周期的问题，提出了基于环分块的能耗均衡分簇路由算法（EBCR-RP）。首先，计算网络能耗最低的单跳距离，并将其作为环间距；然后，优化每环的簇数目，并对每环进行均匀分块，且在每块中选取能量最高的节点担任簇头，以均衡网络能耗；最后，设计传输代价函数，搜索簇头和汇聚节点之间数据的最佳传输路径，以提高网络能量效率。仿真结果表明，EBCR-RP与模糊理论簇形成协议（FLCFP）和改进的非均匀分簇路由（IUCR）算法相比，网络的生命周期分别延长了51.4%和8.6%。EBCR-RP能够有效地延长网络生命周期，均衡网络能耗，提高能量效率。     

能量高效的水声传感器网络多跳非均匀分簇算法

针对现有水声传感器网络(UW-ASN)分簇路由算法存在的能耗不均衡问题,提出了一种能量高效的多跳非均匀分簇(EEMUC)路由算法。通过节点到基站的物理距离建立网络非均匀分层模型,各层区域内的节点根据综合属性值选择簇头,靠近基站的簇的规模小于远离基站的簇。簇间采用多跳路由方式传送数据,从而均衡了簇头的能耗。实验结果表明,所提算法在簇头数目和节点的剩余能量等性能方面优于低能耗自适应分簇路由(LEACH)和能量高效的非均匀分簇(EEUC)算法,从而提高了水声传感器网络的能量效率,并延长了网络的生命周期。     

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.