无线多媒体传感器网络图像通信性能分析

对无线视频传感器节点的图像通信活动进行研究,分析了其在资源受限的无线多媒体传感器网络中进行图像编码和传输的性能。对基于DCT和DWT的图像编码与传输的能量消耗和率失真进行建模分析。根据所建立的能量消耗与率失真模型,对有限的能量和传输带宽进行优化分配。根据监测场景的统计信息,调整编码中所使用的参数,以使得能量消耗最小化。仿真实验结果表明,所提出的方法在保证应用所需图像质量的情况,有效地降低了无线传感器节点的数据通信量和计算过程的能耗。     

基于分布式视频编码的低能耗视频传感器节点研究

在无线多媒体传感器网络中,如何提高节点能源的利用率,延长整个网络的生命周期是当前迫切需要解决的关键问题;从视频数据处理和传输能耗的角度出发,对分布式视频编码(DVC)基础理论及视频传感器节点的能耗模型进行分析和研究;通过实验仿真的方式将H.264帧内编码方案同DVC方案进行比较,实验结果表明了DISCOVER-DVC方案在节点节能方面的优势;最后基于DISCOVER-DVC算法,在S3C6410硬件平台和嵌入式Linux操作系统平台之上完成视频传感器节点设计,来降低节点能耗,提高节点生命周期.     

面向无线多媒体传感器网络的JPEG 2000图像编码算法

在资源受限的无线多媒体传感器网络(WMSNs)中进行图像编码和传输需要综合考虑能量消耗、压缩率和图像质量三者之间平衡的图像编码方案。对基于离散小波变换的图像编码算法的能耗进行建模分析,提出了一种适用于WMSNs的能量有效的JPEG 2000图像编码算法,根据网络条件和图像质量的限制,使用查找表来选择适当的量子化层级和小波变换层级以减少能量消耗。并采用半可靠的方案进行图像传输,节点根据剩余能量和数据优先级来决定转发或丢弃。仿真实验结果表明:所提出的方法能够在保证所要求图像质量的情况下,有效地降低无线传感器节点的计算和通信能耗。     

多媒体传感器网络中基于两跳簇结构的图像传输方案

与传统无线传感器网络节点能量绝大部分消耗在无线收发上不同,无线多媒体传感器网络中数据处理与传输能耗具有“均匀“分布的特点.通过分析表明,传统无线传感器网络簇结构下的数据传输策略并不适合于无线多媒体传感器网络.因此提出了一种基于两跳簇结构的图像传输方案,通过增加中继节点负责图像的压缩编码和转发,在减小相机节点图像传输能耗的同时,大大缓解了相机节点和簇头的图像处理能耗压力.仿真结果表明,该图像传输方案极大的延长了网络的生命周期,非常适合于能量有限的无线多媒体传感器网络.     

WMSN中的分布式视频编码GOP大小控制方法

针对分布式视频编码（DVC）序列在无线多媒体传感器网络（WMSN）中传输可靠性较低的问题,提出了一种考虑节点能耗的图像组（GOP）大小控制方法。该方法分析了DVC编码框架及节点的能量消耗情况,定义了节点的可用度和帧的活动度,并对分布式视频编码序列在编码和传输过程的能耗进行了计算。在此基础上,综合考虑帧的活动度与节点能耗,实现了对分布式视频编码GOP大小的有效控制。仿真实验结果表明,与现有的GOP大小控制方法相比,该方法提高了无线多媒体传感器网络中的DVC序列的峰值信噪比,降低了节点的平均能耗,其传输可靠性也得到了显著改善。     

井下无线多媒体传感器网络图像传输技术研究

本文在分析分布式视频编解码技术具有低复杂度、低存储、低能耗的特点以及无线多媒体传感器网络具有自组织性、放置灵活、移动性强等特点后;根据煤矿巷道狭长的特点,设计一种煤矿井下救灾应急通信系统,并以此系统框架为基础提出了适于井下长距离分布式图像编码传输技术和基于伙伴协助的图像传输方案:多媒体节点将采集到的图像首先进行量化处理,然后将压缩任务分布到伙伴节点,伙伴节点将压缩后的数据传输给簇首,最后由簇首转发该压缩数据至汇集节点,在地面的服务器上进行解压缩和数据融合,合成分辨率较高的图像。最后通过与传统三种基于簇的图像传输方案比较,本文提出的基于伙伴协助的视频流传输方案极大地缓解了多媒体节点的能耗压力,很好地平衡了网络节点能耗,更能有效地延长网络的生命周期。     

一个简化的无线传感器网络管理编码规则

为降低无线传感器网络(WSN)节点能耗并延长网络寿命,基于网络管理操作原语,设计一种简化的WSN管理编码规则。根据网络管理报文的长度,选择一个或多个字节表示网络管理中协议数据单元的长度。理论分析和实验结果表明,该编码规则能降低报文的编码长度及节点的通信能耗,并提高编码效率。     

面向多媒体传感器网络的视频压缩新算法

视频压缩可以降低多媒体传感器网络中的数据信息量。传统分布式视频编码方案采用区域统一编码,可能导致运动剧烈区域解码估计的失真。提出一种改进的分布式视频编码算法。该算法基于图像梯度场,针对Wyner-Ziv帧不能准确编解码的区域,通过ROI判定准则提取该区域并基于熵编码压缩,图像其他区域则基于LDPC实现分布式编解码,进而实现视频的优化传输。仿真实验表明：本文算法可增强运动剧烈区域的编码效率,在降低码率的同时提高解码图像质量,最终降低传感器节点能耗。     

WMSNs图像传感器节点节能研究

提出了一种基于压缩感知理论的低能耗WMSNs图像传感器节点。采用压缩感知(CS)理论,通过对半原始数据稀疏采样来降低后续量化编码的数据量,并能降低节点图像处理复杂度,平衡图像处理和数据传输之间的能量消耗。通过建立能耗模型和Matlab仿真表明,与JPEG相比,采用基于压缩感知理论的压缩编码算法可以有效降低整个节点的能耗。     

一种新的支持移动Sink的多媒体传感器网络路由协议

提出了一种新的支持移动Sink的多媒体传感器网络路由协议,该协议利用锚节点作为转发节点与移动Sink进行通信,避免多媒体传感器节点与Sink直接进行远距离通信,在多媒体传感器节点中采用改进的基于地理信息的路由协议建立路由路径.仿真实验表明:该协议不仅能支持移动Sink,而且能够有效降低节点能耗,延长网络寿命,提高数据传...     

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。     

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.     

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.     

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。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.