共查询到20条相似文献,搜索用时 62 毫秒
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USB总线具有高速传输、热插拔、即插即用等特点,在计算机领域已经得到越来越广泛的应用.介绍了一种采用USB接口的动态视频板的软硬件设计与实现。在硬件设计上他采用单片机和复杂可编程逻辑器件技术,并通过USB接口完成上位计算机控制下视频运动图像的生成。单片机读取上位机前景运动图像位置信息并对视频板图像存储器进行刷新,复杂可编程逻辑器件巡回扫描视频板图像存储器并通过D/A转换后生成视频信号。该系统上位机界面设计采用VB语言。 相似文献
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基于STM32F103的USB主机接口设计 总被引:1,自引:0,他引:1
嵌入式USB主机系统在数据存储和交换领域具有很好的应用前景.为了存储和处理嵌入式系统中的大量数据,一种方法是让嵌入式系统具有USB设备接口,以通讯的方式向上位机不断转储RAM中的数据;另一种方法就是让嵌入式系统具有USB主机接口,使嵌入式系统可以直接读写U盘或SD卡之类的移动存储设备,再通过移动存储设备将数据转储到上位机中,不需要嵌入式系统与上位机之间有直接的通讯连接.使用USB控制芯片CH376设计了一个基于STM32F103的USB主机接口,并应用于嵌入式系统中. 相似文献
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介绍了以S3C2440A为处理器,Micro2440开发板为硬件平台,开发基于嵌入式Linux2.6.32.2操作系统的视频采集系统。该系统以USB摄像头为视频获取工具,通过V4L2编程接口实现摄像头捕获视频数据。实际运行表明,该视频采集系统画面显示稳定流畅、实时性好。 相似文献
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针对嵌入式软件开发采用交叉开发模型,需要频繁把程序从宿主机下载到目标机的要求,研究设计基于Linux的USB集成下载工具。根据USB协议,开发Linux系统的USB驱动模块,基于USB驱动模块,设计出Linux文件下载程序。该工具运行于Linux系统,并利用TQ2440,OK6410,TQ210开发板进行测试。测试结果表明,该工具可以支持2440系列、6410系列、210系列的ARM开发板,并具有很好的扩展性和移植性。 相似文献
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针对视频监控系统智能化的要求,提出了一种基于嵌入式视频监控的人脸检测设计方案。采用在ARM-Linux操作平台上建立Servfox流媒体服务器,实现USB摄像头的视频采集和传输。在客户端首先采用帧间差分更新背景模型的改进算法获取运动目标,减少视频中运动目标对背景模型的影响,且为人脸目标的检测缩小了范围。在运动目标区域内,通过Ada-Boost人脸检测算法,最终获得人脸位置。结果表明,系统对人脸检测效果良好,准确率可达95.2%,检测时间22~27 ms/frame,满足视频监控的实时性要求。 相似文献
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通过在Gene-8315开发板上加载嵌入式VxWorks系统对USB摄像头驱动进行研究。介绍了嵌入式VxWorks系统和USB摄像头驱动结构的特点,分析了spca5xx下USB摄像头视频采集的过程,裁剪并移植了spca5xx下ZC030x系列摄像头的采集过程,实现了基于嵌入式VxWorks系统下对Logitech USB摄像头的驱动和视频采集,并在显示器上显示驱动的过程和采集的结果。最后给出了对USB摄像头视频采集包头数据的分析。 相似文献
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基于GPRS的ARM7嵌入式单片机视频报警系统 总被引:1,自引:0,他引:1
为解决传统视频监控系统中存在的诸多弊端,满足更高的安全需求,提出一种新型的基于GPRS的嵌入式视频报警系统.该系统具有体积小、实时性强、功耗低等特点,并实现了图像的高速采集和传输.它无需处理模拟视频信号的PC机,而是把摄像机输出的模拟视频信号通过嵌入式视频编码器直接转换成IP数字信号.结果表明:该系统对大多数低中速运动物体能有效的发现报警,通过应用GPRS协议,分辨率能达到90%,算法的效率提高8%,传输数据帧的精度提高5%,很好地克服了传统的图像采集系统的缺陷. 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
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. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
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. 相似文献
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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. 相似文献
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Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
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A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
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《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献