基于Linux的无线视频监控系统的研究

随着嵌入式技术、图像压缩技术以及无线传输技术的发展,基于嵌入式系统的无线视频监控系统已成为视频监控领域的发展趋势。文章将嵌入式系统的特点与无线传输技术相结合,研究和开发出一种基于Linux的无线视频监控系统。本嵌入式视频监控系统采用C/S架构,服务器基于ARM11处理器,搭载嵌入式Linux系统,主要实现图像的采集、压缩、预览和传输;PC机作为客户端主要实现视频图像的解压、显示以及参数设置等功能。     

基于TD-SCDMA的ARM9无线视频监控系统设计

本文设计了一个基于TQ2440开发板的无线视频监控系统,前端视频采集编码系统以嵌入式Linux操作系统为平台,运用MPEG-4编解码;传输系统采用中国移动的TD-SCDMA无线网络,无线传输模块采用重邮信科公司的基于TD-SCDMA的TD230A;后端监控系统采用客户机/服务器模式,监控软件采用Socket编程。本文阐述了整个系统的软硬件功能与组成,真正实现了视频监控的无线化,满足无线视频监控系统的要求。     

基于Hi3510和无线发送模块的视频传输设计

为了在嵌入式系统中增加图像数据的无线传输功能,实现终端实时监控的目的,设计了一种嵌入式系统下基于3G无线模块的视频图像数据传输系统.该系统以Hi3510嵌入式Linux系统为平台,采用DTM6211无线发送模块实现视频数据的无线发送.详细介绍了系统各组成部分的功能与实现方法,给出了系统的整体结构框图,程序流程图和嵌入式Linux下无线发送模块设备驱动解决办法.实验结果表明,该系统上行数据的传输速度在150～200 KB/S,与传统2.5G技术的短信方式监控方法相比,数据速度得到很大提高,并实现实时监控.     

嵌入式视频监控系统的设计和实现

近年来,视频监控系统得到了迅速的发展和广泛的应用,将嵌入式技术用于视频监控是其发展的趋势和方向。基于实际的开发需求,设计了一种基于嵌入式Linux的无线视频监控系统,该系统由服务器和客户端两部分组成。服务器通过video4linux接口循环地采集视频并进行MJPEG压缩,然后采用基于802.11g的无线传输协议发送视频。客户端不断地接收视频并进行解码,然后调用SDL在客户端的计算机屏幕上播放监控画面。经测试,该系统实现了视频的实时传输。     

基于CDMA1x的H.264无线远程视频监控押运系统

在分析当前无线远程视频监控系统的发展趋势的基础上,给出了一种基于CDMA1x无线网络,采用DSP实现H.264编码协议的无线远程视频传输系统的设计方案.结合嵌入式Linux构成一个数据采集编码处理终端,将采集到的图像数据按照H.264标准进行编码,得到的码流可以通过CDMA1x无线信道传输.接收端的解码显示图像格式为CIF或QOF视频,采用帧频的方式显示,在有限的带宽内满足应用需求.     

基于ARM11和Linux的网络视频监控系统

论述了一种基于ARM11和Linux平台的网络视频监控系统实现方案。介绍了网络视频监控系统的总体架构,重点论述了视频Web服务器的硬件和软件设计,包括服务器的硬件结构、Linux的移植以及MJPG-streamer的移植。该系统采用B/S模式,以高性能的S3C6410处理器作为视频Web服务器;视频监控终端可以是手机和平板PC等移动终端,也可以是PC等固定终端,采用有线或者无线的方式进行实时视频监控。测试结果表明,系统运行稳定可靠,固定终端和移动终端获取的实时视频图像清晰流畅,无失真和抖动现象,取得了较好的实时视频监控效果。     

基于嵌入式ARM下的视频监控系统的实现

介绍了一种应用于智能家居视频监控系统的实现方案。通过对嵌入式技术的分析和理解,将无线局域网的特点和优势与嵌入式系统相结合,提出并实现了一种无线视频监控的解决方案。该系统以ARMS3C2440为硬件平台,利用Video4Linux2获得USB摄像头采集到的视频图像数据,将其通过UDP协议进行网络传输,最终在PC端的一个基于SDL库设计的程序上进行实时接收并显示。     

基于无线Mesh网络的视频传感器节点研究与设计

视频信息传输对救灾、应急通信和特殊区域监控有着重要意义,网络的适应性和带宽问题是限制视频监控系统发展的重要因素.无线Mesh网络具有带宽高、易组网等优点,能够提供实时的视频传输服务.首先完成对基于Mesh网络的视频监控系统整体架构设计,通过实验仿真的方法对比几种常用的Mesh网络路由协议性能,根据仿真结果和应用需求,选择AODV作为路由协议方案.然后在DM365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.最后对无线Mesh网络多跳带宽性能进行测试,测试结果表明系统可以满足应用需求.     

基于Wi-Fi的移动视频监控平台

基于解决目前监控系统中监控平台无法移动和数据种类过少等问题,采用以STC89C52为控制芯片,以S3C6410作为核心处理器,使用Linux操作系统,搭载USB高清摄像头、Wi-Fi无线传输模块以及移动监控平台,设计出一款可以对现场的环境和视频信息进行采集,并将视频信息与环境信息同时显示在监控软件上的可移动监控平台.     

基于CDMA1x的H．264无线远程视频监控押运系统

在分析当前无线远程视频监控系统的发展趋势的基础上,给出了一种基于CDMA1x无线网络,采用DSP实现H.264编码协议的无线远程视频传输系统的设计方案。结合嵌入式Linux构成一个数据采集编码处理终端,将采集到的图像数据按照H.264标准进行编码,得到的码流可以通过CDMA1x无线信道传输。接收端的解码显示图像格式为CIF或QCIF视频,采用帧频的方式显示,在有限的带宽内满足应用需求。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.