基于OneNET物联网云平台构建视频应用

视频能提供丰富的信息量,如何将种类繁多的视频设备接入物联网,是十分有挑战的课题。本文分析了OneNET云平台视频通信流程及通信协议,并设计了应用服务程序,提出了一种基于OneNET云平台构建视频应用的方案。该方案使用常见的网络摄像头采集音视频数据,通过应用服务程序接入OneNET,客户可通过流媒体播放器观看实时视频。实验表明,应用服务程序有较好的兼容性,不同品牌、型号的视频设备,只要支持ONVIF、RTSP、RTP等协议,即可通过应用服务程序向OneNET上传音视频数据,以较小成本实现视频数据接入物联网。     

基于Hi3531A的视频信号接入系统设计与实现

针对一些普通摄像头、电脑主机、视频会议终端等设备提供的HDMI,VGA,SDI等接口的视频源很难接入视频会议系统和融合通信系统的现状.设计并实现了基于Hi3531A芯片的视频信号接入系统,在指挥调度、多媒体会商、融合通信等多种场景中具有很高的应用价值.介绍了系统总体架构,对系统监控模块、资源管理模块、RTSP/SIP媒体协商模块和MPP视频编解码模块进行了阐述,给出了各模块功能及软件实现方案.     

基于SIP、RTP／RTCP和RTSP协议的视频监控系统

从流媒体协议入手,描述会话发起协议SIP（Session Initiation Protocol）、实时传输协议RTP（Real time Transport Protocol）、实时传输控制协议RTCP（RTP Control Protocol）和实时流传输协议RTSP（Real Time Streaming Protocol）的原理以及它们在IP单播或多播网络上的通信过程。在此基础上,进一步分析RTP/RTCP和RTSP协议的关系,并对基于RTP/RTCP和RTSP协议的流媒体服务器进行设计。流媒体服务器是视频监控系统的核心部分,采用C/S结构,服务器和客户端之间的多媒体数据之间的传递都在这一部分完成。在基于RTP/RTCP和RTSP协议的流媒体服务器的基础上,使用SIP协议让用户和服务器建立会话连接,并在流媒体服务器上进行多媒体数据的传递,从而设计出基于SIP、RTP/RTCP和RTSP协议的视频监控系统。     

基于多协议融合的实时移动视频监控系统

提出一种支持多协议融合的实时视频监控系统的设计与实现方案.系统可通过 Hi3520嵌入式处理器平台和移动端摄像头进行视频采集,采用H.264/AVC压缩编码和参数优化,兼容RTP/RTSP和RTMP多种通信协议进行媒体流传输;设计的Android的移动客户端可以实现视频数据的实时解析、网络串流等.实验测试表明： PC和采集端显示的画面仅有1~1.5秒延迟,系统可以灵活实现不同应用场景下的高清、实时监控.     

基于协议状态图遍历的RTSP协议漏洞挖掘

目前,视频监控设备中很多摄像头、DVR、NVR都支持RTSP协议,而且由RTSP协议引起的缓冲区溢出漏洞个数较多,危害性大,因此对RTSP协议的研究具有 理论意义和 应用价值。直接利用模糊测试框架中的方法生成的测试用例数量庞大,测试过程耗时长。针对上述问题,以视频监控设备的RTSP协议为研究对象,提出对协议基本块的样本集进行去重,利用协议状态间的约束关系和状态转移的关联关系构造协议状态图,并基于协议状态图进行深度遍历的方法。该方法减少了测试用例的生成,并提高了生成的有效性。对RTSP协议进行fuzzy测试时,利用发送TCP探测包的方法,判断测试目标是否异常。去除记录的异常测试用例的冗余部分,以缩短后续重放 过程的耗时,从而提高漏洞挖掘的效率。     

基于TMS320DM8168的RTSP服务器系统设计及实现

基于TMS320DM8168嵌入式平台实现了RTSP流媒体服务器的设计,详细分析了TMS320DM8168的软硬件架构、RTSP服务器的工作原理以及实现过程。以TMS320DM8168为核心,首先将采集的实时视频数据进行模数转换、预处理、H.264编码以及本地存储,然后对H.264码流进行RTP封包,最后发送到网络上进行实时传输。经测试,该系统能同时实现16路D1视频的实时监控并具有较好的实时性。     

基于RTSP的嵌入式视频监控系统设计

设计一种RTSP嵌入式视频监控系统。该系统基于服务器/客户端的模式,用户使用PC机通过以太网实时监控观测对象。系统基于DM3730ARM-Linux平台,通过V4L2接口从摄像头采集视频,通过第三方库libswscale将采集的视频数据转换为YUV420P格式,利用x264对视频数据进行编码;再将上述采集编码系统与Live555开源工程结合,在Live555中构建新的source类,该source类直接从摄像头取数据、编码并输出H264视频流,将此视频流通过RTSP协议传输到客户端,实现整个视频服务器的构建。测试结果表明客户端播放器能够流畅地播放视频数据,系统稳定可靠。     

矿用实时视频传输系统设计

针对现有煤矿井下视频传输系统存在视频清晰度低、传输速率不稳定、兼容性差等问题,设计了一种矿用实时视频传输系统。该系统采用960 nm红外激光作为辅助光源,利用MCCD图像传感器采集视频信号,提高了低光照强度或黑暗环境下视频清晰度;通过视频解码模块TVP5150将采集的PAL制式模拟视频信号转换为YUV数字信号,数字信号经多格式编码器进行H.264压缩编码,并在此基础上添加UDP报文头进行RTP封装,提高了视频数据传输的时效性;通过Live555流媒体服务器进行数据流化,使用ONVIF标准封装RTSP视频流,通过Socket网络编程实现实时视频流数据网络传输,提高了系统兼容性和传输速率稳定性。测试结果表明,该系统视频传输速率为2.190 Mbit/s,丢包率约为1.256%,达到实时视频传输要求。     

基于RTSP的流媒体视频服务器的设计与实现

描述了实时流协议RTSP（Real Time Streaming Protoco1）和相关流媒体协议的原理以及它们在IP单播或多播网络上的通信过程。在此基础上，进一步分析了RTSP／RTP流媒体视频服务器的设计原理和具体实现。最后，介绍了一个基于RTSP服务器开发的视频监控系统。     

网络视频录像系统中视频采集的研究与实现

介绍了一种在网络录像系统（NVR）中实现高清流媒体采集的方案。基于RTSP/RTP协议,实现了对视频数据的封装与传输,结合多线程编程技术,可以满足同时采集多路视频数据的需求,节省了系统资源,提高了用户体验。     

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.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.