基于混沌人工蜂群算法的无线传感器网络覆盖优化

针对无线传感器网络随机播撒的节点严重冗余并且导致网络寿命短、覆盖效率不高等缺陷,提出了一种混沌人工蜂群算法的无线传感器网络覆盖优化算法;将节点的利用率和覆盖率作为优化目标函数,建立与之对应的数学模型,之后用混沌人工蜂群算法改善人工蜂群算法陷入局部最优、收敛慢等问题,提高算法收敛速度和精度,对节点覆盖模型进行求解,得出网络最优覆盖方案;通过实验仿真,提出的算法提高了无线传感器网络的覆盖率,覆盖率可达93.48%以上,减少了网络节点冗余,提高了网络寿命,降低了网络成本。     

一种连通性覆盖的无线传感器网络节点调度算法

研究传感器节点随机部署于监测区域内,无节点地理位置信息情况下,如何能量有效地保证网络的通信连通与感知覆盖;节点采用基于概率的联合感知模型。提出CDS-based SSCA算法,其为一种基于连通支配集构造树的节点调度机制,每个节点根据剩余能量和与父节点的距离来设置等待时间及成为候选节点优先级。模拟实验结果显示,本算法能够能量有效地满足感知覆盖和连通覆盖要求;与ASW算法相比较,工作节点个数较少,网络生命周期明显延长,降低了网络整体耗能。     

能量有效的无线传感器网络协同覆盖

在节点随机分布的无线传感器网络目标覆盖中,考虑到单个节点有时难以完成对目标的感知,利用节点的概率感知模型和漏检率的概念,提出了节点协同覆盖的思想,并建立了协同覆盖模型;详细分析并推导了协同覆盖感知概率、节点数目和节点参与协同覆盖的最低感知概率之间的关系;在协同覆盖模型的基础上,考虑节点能量消耗的因素,设计了优化网络使用寿命的协同覆盖算法ECTC;仿真结果表明,该算法在改善网络感知概率的同时,延长了网络的使用寿命。     

基于改进蜂群算法无线传感器感知节点部署优化*

提出了一种基于改进蜂群算法的无线传感器感知节点部署优化方法,以网络覆盖率为目标函数,将传感器感知节点部署问题形式化为组合优化问题,并采用分层机制对基本蜂群算法进行改进。仿真实验结果表明,本方法能够以相对较小的代价完成传感器感知节点部署,并能降低网络能耗,提高网络的整体覆盖率。     

一种面向多目标关联覆盖的无线传感器网络节点优化调度算法

提出一种面向多目标关联点覆盖的无线传感器网络节点优化调度算法D-MTAC．该算法基于数据挖掘中的关联规则和无线传感器网络的能量高效原则,通过挖掘随机部署的网络节点与待监控目标间的关联感知关系给出高频关联目标集,采用优化时间分片和动态自适应选择机制确定能够令责任节点工作状态与网络寿命实现最优匹配的优化调度决策集合．仿真结果表明：在保证目标监控质量的前提下,该算法能够有效降低网络累积能耗并延长网络寿命．     

异构传感器网络节点部署算法

传感器节点的部署方式有确定性的和自组织两种。研究了由高级节点和普通节点组成的异构传感器网络的节点部署问题。给出一种满足连通覆盖条件的最大化网络寿命模型,通过分析节点的能量消耗,计算出了最大化网络寿命时两种节点的部署比例,提出了最大化网络寿命的节点部署算法。     

基于差分算法的异构无线传感器网络多重覆盖节点调度方案

针对部署区域中存在多个不同覆盖质量需求的目标,本文提出一种基于多重覆盖算法的异构节点调度机制。该算法在满足区域覆盖要求和重点区域监测目标多重覆盖的要求,及节点能量的约束条件下,以网络的有效覆盖率最大和工作节点数目最少为目标,借助改进的差分算法来对节点状态进行优化达到提高网络覆盖性能和降低网络能耗的目的。仿真结果显示,本文的算法在满足热点目标监测要求的前提下,最大限度地兼顾网络的区域覆盖质量,减少了网络的能耗;较之随机调度算法,本文算法在覆盖率和网络能耗方面优于后者。     

多感知范围无线传感器网络中一种分布式目标覆盖算法

基于多感知范围无线传感器网络中节点与目标的覆盖关系,设计了一种目标生命期评估机制。鉴于网络生命期由具有最小生命期的目标决定,在分析节点感知半径变更影响的基础上,提出了两种提高最小目标生命期的策略,建立了一个动态目标覆盖博弈模型,并证明了该博弈存在纯策略的纳什均衡。本文设计了一种分布式目标覆盖算法,算法中节点根据邻居节点的能量分布和目标覆盖情况,选用最优感知半径,以确保目标完全覆盖并延长最小目标生命期。仿真结果表明,在不同的网络中所提算法均能有效地延长网络生命期。     

基于先验概率模型的混合水下传感器网络部署

针对水下传感器网络,结合水声通信和光通信两种通信方式的优点,设计了新的水下传感器网络结构。根据水下目标分布的先验概率模型,提出了混合水下传感器网络部署算法,实现了水下数据的高速传输和水下目标区域的高效覆盖。仿真结果表明,算法能够较好地减少网络部署的节点数目、缩短数据传输延时,减少能量损耗,延长网络寿命。     

异构无线传感器网络中异构节点的部署与优化

在无线传感器网络中适当地部署少量的异构传感器节点能够有效地延长网络寿命,提高网络的可靠性.本文主要研究无线传感器网络中异构节点的部署问题,提出了基于选址问题的异构节点部署算法,以优化无线传感器网络中异构节点的数量和位置.与其它算法相比,该算法对无线传感器网络的拓扑结构没有特定的要求,可以支持随机部署或人工部署的各种传感器网络,最后还给出了该算法的仿真测试结果.     

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.