基于区域簇头选择的WSN路由协议

针对LEACH协议中网络能量不平衡和利用率低的问题,提出一种改进协议(LEACH-V),在计算阈值时引入剩余能量与网络平均能量,并基于Voronoi图单元进行簇头选择。仿真实验结果表明,LEACH-V协议能延长网络寿命,推迟第1个死亡节点出现的时间,提高能量利用率。     

无线传感器网络LEACH协议的改进

延长传感器网络的生存周期,降低传感器节点的能耗成为无线传感器网络（WSN）研究的重点。基于LEACH 协议中簇头生成算法提出了改进、调整节点竞选簇头的阀值函数,并在非簇头节点选择适合自己的最优簇头时综合考虑了候选簇头节点的剩余能量以及距基站的距离等因素,给出了新的成簇机制的适合因子的计算公式。仿真结果表明,新型簇首选择机制能够有效平衡节点的能耗分布,延长节点与网络的寿命。     

基于学习自动机的无线传感网能量均衡分簇算法

优化簇首选择、均衡节点能量负载以延长网络存活时间,一直是无线传感器网络分簇协议研究的重点。针对无线传感器网络节点随机分布的情况,在基于学习自动机(Learning Automata, LA)的ICLA算法基础上,提出一种兼顾节点密度的能耗均衡分簇算法。在簇头选举方面,综合考虑节点剩余能量和节点密度,利用学习自动机与周围环境进行信息交互和动作奖惩,选择出相对较优的簇头;根据簇首与基站距离和其节点密度构造大小非均匀的簇,实现不同位置不同网络疏密程度下簇内和簇间能耗互补均衡;构造了基于簇首剩余能量、簇内节点密度和传输距离的评价函数,并运用贪婪算法选择出最优中转簇首进行多跳传输。仿真实验结果表明,该算法能选择出更为合理的簇头,有效地均衡网络能量负载,延长网络生存时间。     

煤矿采空区无线传感器网络路由协议研究

针对现有的基于能量均衡的无线传感器网络路由协议不适应煤矿采空区应用的问题,提出了一种非均匀分簇能量均衡路由协议,即UCEB-CMF协议。该协议原理如下:优化候选簇首的选择机制,有效保证剩余能量大的传感器节点优先成为候选簇首;改进非均匀竞争半径的计算公式和候选簇首的竞争方法,在考虑剩余能量的基础上,增加了对簇首节点到Sink节点距离的考量,从而实现能耗均衡;针对煤矿采空区传感器节点易消亡的特点,提出了一种多路径路由算法,从而实现数据传输的持续性。仿真结果表明,该协议能有效均衡传感器节点能耗,延长无线传感器网络的生存期,适用于煤矿采空区。     

一种基于时间延迟机制的WSNs非均匀分簇算法

为减少无线传感器网络分簇路由协议中节点竞争簇首时多余的能耗,解决簇首能耗不均的问题,提出一种基于时间延迟机制的非均匀分簇算法。该算法使能量较多的节点被优先选为簇首,并提出了簇首竞争半径的计算方法,确保其数目稳定且位置均匀分布。成簇过程中,节点根据最小消费函数选择簇首,簇内成员加入时考虑簇首能量、二者距离以及簇首和汇聚节点角度等因素来均衡簇首能耗。仿真结果表明:算法能有效地均衡节点能耗,延长网络寿命,分别比CHTD和EEUC算法延长了35.1%和12.9%。     

多判据的无线传感器网络分簇路由算法

无线传感器网络由大量能量受限的传感器节点组成,工作在各种复杂物理环境中完成数据采集、协同处理等功能.如何在节点能量受限的情况下延长网络生存期是设计传感器网络需要考虑的首要因素.分簇的路由算法将网络内的节点分成若干个簇,簇内的每个节点只需与簇首进行通信,簇首将簇内的所有数据进行融合后向基站发送.与平面自组织算法相比,分簇算法具有实现简单,显著降低系统能耗,便于网络管理等优点.文中提出了一种基于LEACH协议改进的多判据的分簇路由选择算法.使节点在选择簇首时进一步考虑簇首的剩余能量,实现网络中能量消耗的均衡分布.通过仿真,证明了这种多判据的路由选择算法能显著延长网络的生存期.     

改进的基于蚁群算法的非均匀分簇路由协议

针对无线传感器网络中传感器节点随机分布造成能耗不均和“热区”等问题,提出了一种改进的基于蚁群算法的非均匀分簇路由协议。该协议也采用“轮”方式运行,每轮簇首选举开始阶段,根据节点剩余能量、节点密度,结合节点到Sink节点的距离来构造不均匀的竞选半径,每个节点根据竞选半径范围内邻居节点计算剩余能量比及距离偏差平均值,从而计算出其簇首竞争等待时间,采用时间等候簇首竞选机制来选举出簇首,平衡簇内的通信能耗;数据传输阶段,考虑剩余能量、通信能耗、链路质量、传输时延等因素,采用改进的蚁群算法构造最优传输路径,数据传输的同时更新信息素,从而达到自适应、动态优化地建立和维护传输路径。仿真结果表明,该路由协议能有效节约能量和均衡能耗,延长网络生命周期,改善链路质量,减少传输时延。     

一种分布式能量有效的无线传感器网络分簇路由协议

提出了一种分布式能量有效的无线传感器网络分簇路由协议DEEC(Distributed Energy-efficient Clustering Algorithm)。该协议采用基于时间的簇首选择算法,广播时间取决于自身剩余能量和其邻居节点的剩余能量。在数据传输阶段,采用簇内单跳与簇间多跳相结合的方式,引入权值函数优化簇首中继节点的选择。仿真实验结果表明,与LEACH,PEGASIS协议相比,DEEC能够有效地节约单个节点能量、均衡网络能耗、延长网络生存周期。     

一种能量均衡的无线传感器网络分簇路由协议

由于无线传感器网络节点能量有限,为均衡无线传感器网络节点之间的能量消耗,提高整体网络的生命周期,针对LEACH协议中簇首选举时未考虑节点剩余能量因素、随机分簇等不足,提出了一种改进的LEACH协议.改进的LEACH协议在簇首选举时,以节点的剩余能量作为重要参考依据,优化节点担任簇首的概率.仿真结果表明,与传统的LEACH协议相比,改进的LEACH协议达到了能量消耗均衡的目标,从而延长了网络的生存寿命.     

基于簇半径差异化和节点能量区间的分簇算法

提出一种基于簇半径差异化和节点能量区间的分簇算法——CRDNE算法.该算法用于解决电子导游系统能量均衡问题,从而尽可能的延长网络寿命.算法首先利用路由跳数将整个网络划分热点和非热点区域,并根据不同区域的通信开销不同的特点,定义了不同的区域簇半径.然后,根据区域簇半径和节点剩余能量所处的能量区间,分布式地选取簇首.最后,将CRDNE算法与LDCR、Leach-V算法在Matlab平台进行多个方面仿真比较,进一步证明了本文算法的优越性.     

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。     

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。