数据传输时延和跳数受限的Sink节点移动路径选择算法

考虑实际无线传感网系统中数据传输时延和跳数受限情况,且为降低算法的时间复杂度,提出一种移动无线传感网的Sink节点移动路径选择算法（MPSA）。在MPSA算法中,Sink节点采用分布式最短路径树算法收集k+1跳通信范围内传感节点的相关信息和感知数据,采用虚拟力理论计算边界、障碍物和空洞区域的虚拟斥力、第k+1跳未覆盖传感节点的虚拟引力和所有虚拟力的合力,根据停留次数、合力大小和方向等信息计算当前网格中心的停留时间和下一个停留网格中心。仿真结果表明：MPSA算法根据传感节点的位置、剩余能量等信息,寻找到一条较优的移动路径,从而提高Sink节点的数据收集量和节点覆盖率,降低传感节点的感知数据丢弃量。总之,在数据传输时延和跳数受限下,MPSA算法比RAND算法、GMRE算法和EASR算法更优。     

一种无线传感网的Sink节点移动路径规划算法研究

为寻找传感节点均匀分布时Sink节点的最优移动路径和最大网络生存时间,提出一种无线传感网的Sink节点移动路径规划算法(MPOA).在MPOA算法中,将Sink节点的数据收集范围分解成多个圆环,将监测区域分解成多个网格.根据Sink节点的停留位置和多跳通信方式,采用数学公式表示每一个网格的单位节点能耗,从而获得Sink节点移动的网络生存时间优化模型.采用修正的混合粒子群算法求解该优化模型,获得网络生存时间、Sink节点的停留位置和移动路径的最优方案.仿真结果表明:MPOA算法可寻找到Sink节点的最优移动路径,从而平衡网络能耗,提高网络生存时间.在一定的条件下,MPOA算法比Circle,Rect和Rand算法更优.     

Sink节点移动的无线传感网生存时间优化算法

为提高网络最大生存时间,提出Sink节点移动的无线传感网生存时间优化算法(LOAMSN)。该算法分析Sink节点移动时的流量平衡约束、最大传输速率约束、节点能耗约束等约束条件,将生存时间优化问题转化成优化模型。提出Sink节点的移动方法,即Sink节点利用节点的度值构建其移动路径,按照此路径循环移动收集数据。将Sink节点的移动认为是离散运动,Sink节点移动的生存时间优化模型分解成若干个Sink节点静止的生存时间优化模型,采用牛顿法求解每个Sink节点静止的优化模型,获得网络最大生存时间和节点发送数据量的最优值。仿真结果表明:LOAMSN算法能减少Sink节点停留位置上的节点能耗,平衡网络负载和节点能耗,提高网络最大生存时间。在一定条件下,LOAMSN算法比Sink节点静止时更优。     

Sink节点移动的三维无线传感网数据收集算法研究

为克服三维静态无线传感网中的能量空穴问题和提高网络生存时间,考虑Sink节点移动,提出一种Sink节点移动的三维无线传感网数据收集算法(DCA-TWSN),在DCA-TWSN中,提出三维环境下的正方体网格划分方法,建立包括Sink 移动路径选择约束、数据流量约束、能耗约束、链路约束等约束条件的数据收集优化模型,采用最优化方法求解已知Sink节点移动路径的数据收集优化问题,采用修正的蚁群算法求解Sink节点的移动路径问题,获得最优方案。仿真结果表明:不管Sink节点的最大数据收集跳数和传感节点数量如何变化,DCA-TWSN都能寻找到较优的移动路径和数据传输方案,从而提高了网络生存时间和传感节点的平均数据传输率,降低了移动路径长度、平均节点能耗方差和丢包率,比RAND、GREED和EDG-3D更优。     

移动无线传感网的移动感知路径选择算法

为解决稀疏网络环境下移动传感节点的区域全覆盖和数据传输问题,提出一种移动无线传感网的移动感知路径选择算法(MSPS)。在MSPS算法中,用数学公式表示邻居网格集合、区域覆盖率、数据传输时延、节点平均能耗等参数。采用机会路由算法进行数据传输,并建立能保证全覆盖监测区域且权衡数据传输时延、数据传输率和节点平均能耗的移动路径选择优化模型。提出到目标网格的路径寻找方法、初始染色体的确定方法和染色体适应度值计算方法。最终提出修正的多种群遗传算法求解优化模型,获得移动传感节点的最优移动方案。仿真结果表明:不管监测区域内是否存在障碍物,MSPS算法都能提高数据传输率,降低数据传输时延和节点丢弃的总数据量。在一定的条件下,MSPS算法比SGA、TCM_M、RAND_D和RAND算法更优。     

基于Q学习的多Sink节点无线传感网路由机制研究

单Sink节点无线传感网存在部分关键区域节点能量消耗过快、路由选择算法单一及Sink节点失效的问题.多Sink节点无线传感网能有效解决上述问题,研究多Sink节点传感网的路由协议及其存在的不足,提出了一种基于Q学习的路由选择机制.利用该学习方法节点综合考虑各种环境因素,进行周期性的学习训练,优化路径选择,最后按照计算得...     

无线传感网中一种智能数据融合算法的实现及仿真分析

在无线传感网中,传感器节点一般都由自身装配的电池供电,难以进行电量补充,因此节约电量对于无线传感网来说至关重要.为了提高无线传感网能量使用效率,延长网络生存时间,提出了一种结合遗传算法和粒子群算法优化BP神经网络的智能数据融合算法 GAPSOBP(BP Neural Network Data Fusion algorithm optimized by Genetic algorithm and Particle swarm).GAPSOBP算法将无线传感网的节点类比为BP神经网络中的神经元,通过神经网络提取无线传感网采集的感知数据并结合分簇路由对收集的传感数据进行融合处理,从而大幅减少发往汇聚节点的网络数据量.仿真结果表明,与经典LEACH算法和PSOBP算法相比,GAPSOBP算法能有效减少网络通信量,节约节点能量,显著延长网络生存时间.     

无线传感器网络覆盖优化算法的仿真研究

关于优化网络生命周期,研究无线传感器覆盖问题,针对无线传感器网络节点存在严重冗余问题,影响网络覆盖优化机制,导致传统算法网络覆盖率低,能量大量消耗,网络生存时间短等难题.为了提高无线传感器网络的覆盖率,有效延长网络生存时间,提出一种基于蚁群算法的无线传感网络覆盖优化机制.首先把网络监测区域划离散化成若干个网格点,将网络有效覆盖率和节点最小利用率作为优化目标,建立一个组合优化数学模型,然后利用蚁群算法对优化模型进行求解,从而得到最优网络覆盖率.仿真结果表明,不仅很好地降低了节点的冗余,减少了网络的能量消耗,而且有效地提高了网络的覆盖率,从而达到了延长网络的生存周期的目的.     

面向带状无线传感网低延迟可靠数据收集算法

带状无线传感网为长距离带状分布，现有的数据收集算法无法很好解决其数据收集延迟较大的问题。提出了一种主动定位移动Sink的数据收集算法DCFAN（Data Collection based on Forwarding of Agent Nodes），DCFAN构建移动Sink的同步代理节点以及存储同步代理节点的线节点序列，通过获取同步代理节点转发感知数据到Sink汇聚点。仿真结果表明，DCFAN算法能有效降低网络节点能耗以及数据收集延迟，同时提升数据收集率，适用于对数据收集延迟具有一定要求的带状无线传感网应用场景。     

WSN中基于移动Sink的高效数据收集算法

针对无线传感器网络中的数据收集问题,提出一种改进的MWSF算法。该算法结合A*算法求解出移动Sink在传感器节点之间移动的最短路径,利用MWSF算法找到移动Sink所需访问的下一个传感器节点,并与单跳通信范围内的其他传感器节点进行通信,从而收集数据。仿真结果表明,该算法能降低数据溢出发生率,提高网络的数据传输效率。     

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     

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.     

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。