基于小波树模型的CoSaMP压缩感知算法

无线传感网络存在网络带宽限制和传感器节点的能耗问题,实际应用中通常希望可以通过重构算法从采集的少量数据中还原出原始信息,压缩感知理论为上述问题提供了一个解决思路。利用压缩感知理论,对无线传感器网络中温度传感器的监测信号进行了压缩感知的应用研究。针对传统压缩采样匹配追踪(CoSaMP)算法中测量次数多、重构精度低等问题,利用信号的小波系数所形成的连通树的结构特性,提出了基于小波树模型的压缩采样匹配追踪算法。将该算法应用到无线传感器网络监测信号的压缩感知仿真实验中,与传统压缩采样匹配追踪算法的重构性能进行比较,结果表明该算法较传统压缩采样匹配追踪算法在一定范围内对无线传感器网络中的温度信号具有更好的压缩感知性能。     

基于分布式压缩感知的无线传感器网络异常数据处理

无线传感器网络的海量数据采集、传输和处理,对传感器节点的处理能力和功耗提出了严峻挑战,而且现实环境中传感器故障或者环境因素的突变会导致部分采集数据异常,而传统的数据处理方法无法对包含异常的数据进行有效的处理。针对上述问题,文中提出了两类无线传感器网络的异常数据模型,以及相应的基于分布式压缩感知的异常数据处理方法。通过协同的多个传感器进行数据压缩采样,当多个传感器采集的数据包含异常成分时,分布式压缩感知技术对数据中相同的正常分量进行一次统一重构,仅对不同的异常分量进行单独重构,从而避免了对相同数据分量的重复处理,提高了对包含异常成分数据处理的效率。另外,分布式压缩感知技术充分利用数据间的相关性,可有效减少传感器网络的数据采集量,加强其对抗异常数据的鲁棒性。对两类异常数据模型的数值仿真结果表明:相比于传统的基于单组测量值的压缩感知技术,基于分布式压缩感知技术的数据处理方法在提高异常数据重构准确率的同时,将采样数据量减少了约33%,证明了该方法的有效性。     

基于压缩感知的链型无线传感器网络节能数据收集

无线传感器网络(WSNs)中节点受体积、功率、成本等限制而导致了节点能量、生命周期有限的问题.提出一种基于压缩感知算法的无线传感器网络节能优化方法,并结合无线传感器网络中的链型拓扑网络模型,给出基于压缩感知理论的节能网络数据传输模型.通过理论分析比较表明压缩感知方法在节能方面的优越性,然后在得出的网络能耗模型的基础上进行仿真.仿真结果表明:压缩感知方法有效减少了网络能耗.     

WSN中的分布式压缩感知

为了解决传统的压缩感知算法在无线传感器网络中实现的难题,首先研究了用定时器控制ADC进行随机压缩采样的压缩感知技术,实验表明,该方法有效可行。在此基础上提出了基于无线传感器网络的分布式压缩感知算法。该算法通过对随机压缩采样序列的拆分实现分布式压缩采样,最后利用合并后的采样值和CoSaMP算法完成对信号的重构。仿真和实验表明,该方法能够在星型网络拓扑中实现以1/10的标准采样频率下实现信号的重构。     

基于贝叶斯压缩感知的无线传感器网络节点定位

本文研究无线传感器网络多目标时应用了压缩感知,对建立该传感器的网络模型的过程进行了分析,阐述了传感器节点二维位置重构的算法,并使用MATLAB进行仿真,得知定位无线传感器网络节点时应用贝叶斯压缩感知的有效性。     

单比特压缩感知理论及应用研究

单比特压缩感知是量化压缩感知的极限形式,该方法采集的是观测值的符号,仅需要1个比特单元来记录这个值,因此在硬件实施上成本低,运行速度快。目前,单比特压缩感知技术已经成为一个研究热点。本文首先介绍了单比特压缩感知的发展和研究现状,然后从检测和不检测观测符号两个方面对重构算法进行了分析,接着从单比特压缩感知的成像领域、无线传感器网络领域、医学图像领域和信号传输领域四个应用领域进行分析,最后对单比特压缩感知技术进行了总结和展望。     

基于分类的分布式压缩感知算法

在无线传感器网络中,压缩感知是一种新兴的数据融合方法,能利用少量数据采样进行数据恢复。由于具有较好的节省能耗的性质,压缩感知受到研究人员越来越多的关注。然而,传统的应用于无线传感器网络中压缩感知方法是在汇聚节点得到所有节点的加权和,然后利用重构算法对整个网络中各节点的数据进行恢复,并没有考虑到网络节点的分布式的特性。因此,当网络拓扑较复杂时,应用压缩感知时数据需要传输的次数并不会低于利用最短路径树时数据需要传输的次数。在该文中,我们考虑如何将压缩感知技术更好的和网络节点的分布式结构相结合,使得该技术的更加符合无线传感器网络的需求。     

无线传感器网络基于压缩感知数据处理算法研究

无线传感器网络中的分布式数据处理处理时,会出现数据压缩率低和数据相关性差的特点,在数据采集和处理中采用分布式压缩感知算法.对基础矩阵和观测矩阵的合理建立,在满足无线传感器网络数据传输的可靠性同时,充分考虑数据之间的相关性,大大降低数据的冗余度,减少了数据量的传输.实验结果表明,在满足信号数据可靠性的同时,有效的增加了信号的压缩比,减少了节点数据采集量.     

基于压缩感知和双簇头交替的WSNs路由算法

提出了一种基于压缩感知和双簇头交替的无线传感器网络分层路由算法CS-DC HA(Compressed Sensing-Double Cluster Head Alternation)。该算法对DCHS(Deterministic Cluster-head Selection)算法进行改进,利用压缩感知理论优化稀疏采样过程;采用双簇头交替方法进行路由选择,进而实现减低能耗;同时以贝叶斯算法进行稀疏信号重构。通过实验可以看出,相比于传统的无线传感器监测网络,CS-DCHA算法保证了在一定的信号重构精度条件下,能降低无线传感器网络的能耗并延长其生存时间。     

压缩感知在无线传感网络的应用综述

随着信息技术的发展,近些年压缩感知技术格外引人瞩目,在图像视频编码、雷达及微波辐射成像、气象卫星、图像加密、物联网等领域展现出强大的功能与发展前景。首先介绍了压缩感知在无线传感网络领域的发展及研究现状,然后从压缩感知仿真实验和实例、压缩感知的测量方案、压缩感知的解压缩方案、压缩感知在无线传感网络的具体应用四个方面阐明了压缩感知在无线传感网络领域的优势,最后对压缩感知的前景进行了展望。     

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。