基于IMCB算法的无线传感器网络节点定位

针对蒙特卡洛盒(MCB)移动定位算法中存在的样本点退化问题,提出一种改进的蒙特卡洛盒(IMCB)定位算法,将其应用于无线传感器网络节点定位中。在MCB算法的基础上,通过分析当前时刻定位结果、节点距离以及相对位置信息,获得下一时刻在样本盒不同区域的采样概率,使样本点尽可能落在后验概率较大的区域内,从而解决MCB算法样本点退化导致定位精度降低的问题。仿真实验结果表明,在相同条件下,与MCB、MCL算法相比,IMCB算法的平均定位精度提高约14%,平均定位能耗降低约17%。     

基于接收信号强度指示测距的蒙特卡罗盒移动节点定位算法

针对无线传感器网络(WSN)中以蒙特卡罗为基础的移动节点定位算法在采样效率和定位精度方面的不足,提出一种基于接收信号强度指示(RSSI)测距的蒙特卡罗盒定位(MCB)算法。通过对RSSI测距信息分区间管理来加强过滤条件,提高定位精度;同时采样阶段利用已满足过滤条件的样本点生成更有效的样本,从而提高采样效率;最后通过牛顿插值法预测节点运动轨迹,样本点与未知节点运动轨迹越接近则其权值越大,据此对样本点进行加权处理得到节点的最佳估计位置。仿真结果表明,改进方案在不同的锚节点密度、通信半径、运动速度等情况下均表现出良好性能,且定位精度与同等条件下的蒙特卡罗盒算法相比均有提高。     

基于跳距修正L-M优化的WSN定位算法

针对DV-Hop定位算法在节点随机分布的网络拓扑环境下存在误差较大的问题,文中通过分析平均跳距估计、未知节点坐标估计区域求解对定位精度的影响,提出了一种基于跳距修正L-M优化的WSN定位算法CLDV-Hop(Correct L-M DV-Hop)。仿真结果表明,在不增加额外开销且仿真环境相同的条件下,CLDV-Hop算法比现有改进的算法具有更高的定位精度,与DV-Hop算法相比精度提高了约33%——41%。     

基于MCB的传感网移动目标定位算法

针对MCB移动定位算法在实时信息采样方面的不足,提出了EMCB(Enhanced Monte-Carlo localizationBoxed)定位算法。该算法在MCB算法基础之上,引入遗传算法中的变异和交叉操作,使样本选择向后验密度值较大的区域转移,从而有效地解决了原算法存在的成功采样率较低的问题。仿真实验结果表明,同MCB算法相比,EMCB算法平均采样数减少了约30%,定位精度提高了约17%。     

一种基于MCB的自适应和声搜索定位算法

针对无线传感器网络锚节点稀疏条件下节点定位中存在的翻转现象和定位精度问题,提出了一种基于MCB的自适应和声搜索定位算法。通过引入MCB算法中的采样思想,随机产生网络拓扑约束下的未知节点的坐标,引入自适应的和声保留概率和音调调节概率,达到提高搜索能力和定位精度目的。仿真结果表明：算法能有效解决翻转现象,提高定位精度,提出的算法在定位精度和计算量方面优于对比算法。     

锚节点静止的无线传感网定位算法

节点定位是无线传感网应用中的一个基础问题。针对锚节点静止而定位节点移动的无线传感网,改进MCB(Monte Carlo localization Boxed)定位算法。由于MCB算法只利用了当前时刻的一跳锚节点信息建立信标盒子,所以不能利用前一时刻锚节点的信息。在许多传感网中锚节点是静止的,所以可以利用前一时刻的锚节点信息。该算法以蒙特卡洛方法为基础,利用前一时刻的一跳锚节点信息和最大速度建立信标盒子,缩小了MCB算法的采样空间。实验结果表明,所提出的算法能够有效减小MCB算法的采样次数和提高定位精度。     

小波变换预测移动节点定位算法

针对无线传感器网络移动节点定位精度不高的问题,提出一种基于小波变换预测的移动节点定位算法。根据历史运动轨迹通过小波变换预测节点当前位置,精确采样区域,应用自适应采样方法减少采样次数,通过加权滤波增大高质量样本点以及降低低质量样本点对定位结果的影响,提高定位精度。仿真结果表明,在锚节点数目、通信半径、最大样本点数目等条件变化的情况下,该算法与传统算法相比提高了定位精度,在低锚节点密度环境下表现出良好的效果。     

一种基于多重共线性的三维DV-Hop定位算法

针对多边测距法的不足,考虑定位算法所应用的现实环境,在典型DV-Hop算法的基础上,提出了一种改进的三维定位算法。该算法除了将DV-Hop定位算法从二维空间移植到三维空间以外,着重考虑了信标节点拓扑关系和跳数对定位精度的影响,提出一种基于多重共线性的三维DV-Hop定位算法MCB3D DV-Hop。该算法通过设置跳数阂值与多重共线性阂值两个阂值参数,挑选网络中好的信标节点组进行位置估计。理论分析和仿真实验结果表明了算法有较高的定位精度和稳定性。     

基于DV-Hop定位算法的改进研究

在无线传感器网络DV-Hop定位算法中,网络平均跳距离的估算是决定定位精度的重要因素之一。传统的DV-Hop定位算法只考虑了最近一个锚节点佑计的平均跳距,从而导致定位误差较大。为了提高节点定位精度,在原算法基础上提出了一种改进算法,考虑使用多个锚节点佑算的平均跳距离并且采用加权平均跳距代替传统算法中的平均跳距。仿真实验结果表明,在相同的网络环境下,改进后的算法能有效地减少跳距计算带来的定位误差,提高定位精度。     

基于跳数修正的DV-Hop改进算法

针对无线传感器网络DV-Hop定位算法在实际应用中定位误差较大的问题,提出一种基于跳数修正的改进算法。在引入限跳机制的条件下,按未知节点与信标节点间的跳数值分类估算,对1跳区域内的节点采用RSSI测距技术,对于节点间跳数值大于1跳的节点,则利用信标节点间实际距离与估计距离的误差值修正平均每跳距离。仿真实验表明,在相同的网络条件下,与原DV-Hop定位算法和其他改进算法相比,改进后的算法能更有效地减少跳距估算带来的定位误差,提高平均定位精度并保持较好的算法稳定性。     

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.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。