嵌入式实时视频通信系统设计与关键技术研究

为了解决嵌入式视频通信系统普遍存在的实时性不好,服务质量不可控的问题,论述了嵌入式实时视频通信系统设计以及系统实现过程中若干关键技术问题的解决方案。在TI DM642EVM视频处理平台上设计并实现了一个嵌入式实时视频传输系统。提出应用层服务质量(QoS:Quality of Service)控制机制,实现了网络视频的实时传输。参考IP网络多媒体通信协议H.323框架进行系统控制,采用实时传输协议(Real-Tim eTransport Protocol)进行传输控制和网络状况反馈。实验结果表明,在同等网络条件下,这种QoS控制机制具有较好的视频传输质量,而且具有良好的扩展性。     

嵌入式网络实时视频监控系统的设计

基于目前视频监控系统的现状,提出了一个基于嵌入式系统的网络实时视频监控系统.其服务端以S3C2410嵌入式平台为核心、IME6400及附属电路为扩展功能,并采用了嵌入式Linux操作系统.在Linux设备驱动中设计和实现了零拷贝技术,保证了压缩编码后的视频流数据在系统内存中只存在1份实体而无其他的拷贝,这样就提高了系统内存的使用效率,并且减少了CPU的资源消耗.依照RTP协议进行实时视频流传输,同时采用嵌入式Web方式,并且支持ActiveX,用户只需使用IE浏览器就可以完成实时监控.该嵌入式视频监控系统构建灵活,占用资源少,系统效率高,有较高的可靠性和安全性,因此具有较大的市场潜力.     

嵌入式无线视频监控系统的设计与实现

嵌入式无线视频监控系统在Samsung的s3c2410微处理器平台上,搭建armlinux软件环境,通过USB摄像头实时获取视频,综合利用点对点(PPP)拨号机制、多线程通信、Video4Linux编程和基于UDP的C/S软件结构,实现了视频图像在CDMA网络上的实时低码率传输,从而达到了无线视频监控的目的.     

嵌入式微处理器环境下视频流的采集与传输

提出了一种基于嵌入式技术的网络视频监控系统实现方案。系统以嵌入式Linux操作系统和嵌入式S3C2440微处理器为核心平台,建立基于TCP/IP协议的视频服务器,将摄像头采集来的图像数据压缩为MPEG-4视频流后,经过网络传输,完成对监控现场的网络视频监控任务。     

工程机群的通信与GPS定位装置的设计与实现

智能化工程机械的GPS定位与监控中心的通信装置是实现工程机械机群化管理的关键装置 .根据工程机械机群工作的特殊性 ,设计了具有WLAN方式和GSM方式相结合的双模无线通信网络 .利用嵌入式计算机作为硬件平台 ,开发了采集GPS数据和工程机械上重要数据的硬件设备 ,并利用嵌入式Linux系统作为软件平台 ,开发了一套能够根据网络情况自由选择的利用WLAN网络或GSM网络通信的软件 .利用上述网络和软硬件 ,实现了单个工程机械向监控中心的数据传输 .     

嵌入式智能网络视频监控系统设计与实现

网络视频监控是进行远程分布式视频监控的重要途径。设计实现了一个基于DSP的嵌入式智能网络视频监控系统。整个系统包括视频服务器端、视频客户端和视频控制端三大部分。其中服务器端采用自行研制的嵌入式DSP开发平台实现，具有体积小、智能判断运动目标等特点。测试结果表明，该系统运行稳定，对于D1格式的视频图像，能达到实时网络视频监控的目的。     

基于FPGA的动态家居安防系统的设计

为了实现在减少Zigbee网络节点的前提下,又能实时捕捉用户所需信息的目标,提出了一种基于现场可编程逻辑阵列(FPGA)芯片———Zynq的动态智能家居系统.该系统采用智能小车作为移动网关,Zigbee作网络节点,用Sim300 GSM模块来实现短信收发功能.远程用户能够实时获取家里的信息;并且可以用短信以及Internet与智能家居网关进行通信,从而实现对智能家居系统的远程控制.     

网络化的楼宇可视终端系统的设计

为了克服以往模拟监控系统在信号、布线、传输距离方面的局限性及以PC机为用户端的网络监控系统的体积限制,提出了基于嵌入式Linux的网络可视终端系统的解决方案.在电子门侧采用嵌入式Linux平台,利用Video ForLinux内核接口函数,结合USB摄像头来实现单帧和视频连续帧的采集,采用MJPEG标准进行视频图像压缩,通过TCP/IP协议实现网络传输;在用户端用支持嵌入式Linux的彩屏终端系统对视频数据进行接收、解码和显示.该方案使监控系统小型化、低成本化,且图像显示清晰、实时性好.     

基于RTSP和H.264的嵌入式网络视频监控系统

本文主要介绍了基于ARM处理器S3C6410、嵌入式linux、嵌入式Live555的流媒体服务器的视频监控系统设计方案,实现了Live555对H.264压缩编码的支持、基于RTP/RTCP及RTSP协议的视频数据实时传输和基于VLC播放器的视频数据解码播放。     

嵌入式DaVinci平台视频服务器的设计

从软件工程层面分析了嵌入式SoC达芬奇平台的硬件系统、架构和组件技术,介绍了达芬奇软件资源、操作系统移植、流媒体应用系统搭建以及嵌入式中间件的概念,提出了利用达芬奇架构和H.264算法组件设计一个高质量、低成本的基于SIP的流媒体传输系统的方法,详细阐述了现场端嵌入式系统的硬件设计和监控中心软件的实现.嵌入式视频服务器在网络和远程视频监控中得到了较好的应用,与传统的视频监控系统相比较,该方案具有成本低、体积小、稳定性好、可靠度高等优点.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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