基于GM8126的数字可视对讲系统设计与实现

为了设计高性能数字可视对讲系统,采用GM8126芯片作为主控芯片,利用Android智能手机作为室内机,设计并实现了一款可视对讲系统。采用多线程技术实现音频数据、命令数据的双向传输、视频数据的单向传输,采用H.264格式对视频数据进行硬件编码、软件解码,选用G.711A率标准压缩音频数据,利用RTSP协议实现音视频数据的实时同步传输。测试结果表明,该系统音视频效果良好、运行稳定。     

业界聚焦

韩国4G技术速率达3.6Gbps传送80个高清频道韩国电子通信研究院(ETRI)于近日展示了4G无线系统,在低速移动状态下实现了3.6Gbps的传输速率。ETRI实现了对80个高清电视频道同时进行实时传输,还利用FTP文件传输展示了高速传送移动数据。     

基于ARM的无线音视频监控系统设计

介绍了一种基于ARM硬件平台和WinCE软件平台的无线音视频监控系统设计方案.该设计应用三星公司的S3C2440A为主芯片,结合摄像头、麦克风和GPRS模块等实现数据的采集、处理和网络传送.S3C2440A具有丰富的硬件接口资源,采用H.264作为音视频数据压缩的核心算法,具有很高的数据压缩比率,适合无线传输.     

HDMI接口的基本原理

一、综述随着音视频产品和格式的发展,特别是HDTV产品日益被普通消费者所接受,高清格式节目所带来的大量数据的传输压力、更多的高保真声道导致的布线混乱, 以及日益重要的高清音视频节目版权保护,都向技术发展提出了新的需求。目前,主流数字家电的接口规范只能传输压缩或未压缩数字视频信号,音频信号需要单独的接口进行连接,这在使用过程中给普通消费者带来了诸多不便。     

研发动态

IBM计划开发10PFLOPS超级计算机；芯片中采用微波传输信号技术；依据主题分割音视频内容；IEEE暂停移动宽带工作组802．20开发工作；移动通信运营商成立4G服务组织[编者按]     

基于CMOS图像传感器的高清音视频采集及网络传输技术

为提高高清音视频采集效率，提高网络传输的稳定性，研究基于CMOS图像传感器的高清音视频采集及网络传输技术。利用CMOS图像传感器，采集高清音视频；为提高网络传输的稳定性，在传输前对音视频进行本地缓存；对高清音视频封装，并利用TCP通信协议和UDP通信协议完成网络传输。实验结果表明：设计的采集与传输技术在实际应用中可以有效缩短采集过程中的延时，并保证更加稳定的网络传输。     

嵌入式短距离无线音视频监控系统设计

嵌入式短距离无线音视频视监控系统主要由音视频采集发射端和接收端两部分组成,采用2.4G无线数据通信模块TX24500和RX2188完成音视频的传输功能,给出了具体的电路;接收终端利用嵌入式的S3C2440处理器设计,在WinCE5.0操作系统下开发应用程序,同时并给出了详细的软件设计步骤和软件流程图;该系统能够实现四路音视频同时传输和显示,并且可以录制到大容量硬盘作为备份,实现了便携、移动监控的功能.     

基于ARM-Linux的无线音视频传输系统

本文设计了一种基于S3C2410X微处理器、Linux操作系统的无线多媒体传输系统.论文首先介绍了系统的结构功能设计;接着给出了嵌入式无线音视频传输系统软硬件设计方案,包括系统发送端硬件结构设计和接收端硬件结构设计,并且给出了各个功能模块的芯片选择;最后,以嵌入式Linux操作系统为软件平台,WLAN为传输媒介的平台构架和环境搭建,设计并且实现了嵌入式无线音视频传输系统应用程序.     

基于GPRS的无线传感器网络数据中转器的设计

介绍了数据中转器的必要性和GPRS网络的特点和连接方法,提出了一种嵌入式数据采集无线传输的方法。采集数据通过ZigBee网络传至汇聚节点再传到数据中转器ARM芯片,ARM芯片完成采集数据存储和无线数据传送的功能。采集数据存储在铁电存储器中;无线数据传送部分采用SIM300C模块,通过GPRS网络将采集的数据传送到远程服务器上。该软件设计方案不仅满足系统实时性要求,而且具有数据传输稳定、可靠等优点。     

矿井无线音视频终端设计

介绍了一种矿井无线音视频终端的结构及软硬件设计方案。该终端的收发端均采用S3C6410处理器,成本较低;软件基于Linux嵌入式操作系统,实时性及稳定性好;收发端通过无线WiFi网络传输数据。测试结果表明,该终端正常传输音视频数据时,CPU占用率不超过5%;室内信号传输距离约为100m,室外信号传输距离约为300m。     

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.