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1.
循环码的周期分布的新的计算公式   总被引:18,自引:1,他引:17  
本文在[1]文的基础上进一步分析了循环码的周期分布的性质,给出了新的计算方法和公式,并且确定了一些熟知的循环码的周期分布。  相似文献   

2.
本文介绍了锂电池的优点以及它在使用过程中的难点。介绍了过充过放电对锂电池的危害,分析了常见锂电池保护电路的工作过程,提出了在使用锂电池保护芯片时的注意事项。  相似文献   

3.
异步传输方式的HDLC协议的实现   总被引:1,自引:0,他引:1  
研究实现了一种HDLC(High Level Data Link Control)协议的改进方法,该方法把HDLC协议传统的同步传输方式改成了异步传输方式,既保留了原有HDLC协议的主要优点,又增强了传输数据的抗干扰性能,并节省了通信系统的同步时钟接口连线.文中简要介绍了HDLC的协议规程,并提供了CRC及删"0"部分的VHDL代码.最后,描述了HDLC协议的异步传输方式,并通过FPGA完成了HDLC协议的改进.  相似文献   

4.
秦敏 《通讯世界》2016,(7):213-213
本文重点分析了现代家居智能化系统的需要实现的基本功能,探讨了于Zigbee技术的家居智能控制系统的整个设计思路,从硬软件的角度解析了家居智能控制系统具体设计细节等。  相似文献   

5.
纪捷先 《电子技术》2010,47(7):42-43
数字下变频技术是软件无线电的核心技术之一。本文首先介绍了DDC的组成结构,然后详细分析了DDC各功能模块的工作原理,通过Modelsim完成了DDC其主要模块的仿真和调试,并进行初步系统级验证。在仿真的基础上使用了FPGA开发系统,实测了DDC的性能。  相似文献   

6.
本文首先介绍了当前的无线网络的发展,并对P2P做了相关说明。然后把JXTA与当前的主要P2P技术进行了比较,随后仔细讲解了如何构建基于JXTA的网络,最后通过一个demo对系统做了试验,并得到了一些结论。  相似文献   

7.
本首先介绍了当前的无线网络的发展,并对P2P做了相关说明。然后把JXTA与当前的主要P2P技术进行了比较,随后仔细讲解了如何构建基于JXTA的网络,最后通过一个demo对系统做了试验,并得到了一些结论。  相似文献   

8.
首先简要介绍了基于LDP的VPLS的工作原理,然后探讨了层次化体系结构下的两种VPLS的实施模型,比较了这几种不同实施模型的VPLS的特点和适用环境.  相似文献   

9.
在计算机技术和流媒体技术的快速发展下,视频点播(VOD)系统得到了广泛的应用,伴随着嵌入式技术和网络技术的发展,出现了基于嵌入式的视频点播系统,本文介绍了基于ARM9的嵌入式视频点播系统的组成,重点阐述了该系统的工作原理、设计方案、软硬件模块的实现方法。  相似文献   

10.
李旺铭 《电子技术》1995,22(3):18-22
文章分析了单片机控制的频率合成器,阐述了单片机控制分频器分频比的原理.并且个绍了单片机控制部分的设计。给出了主要部分的框图及程序。  相似文献   

11.
利用软硬件结合方式,设计一种针对舰艇雷达及电子对抗装备主要性能的测试及评估系统,实现非接触测试,无须上舰,在距离舰艇100~200 m的码头,采用"定量比对法"对雷达及对抗装备的关键参数进行测试和评估。  相似文献   

12.
3G接入技术中认证鉴权的安全性研究   总被引:5,自引:0,他引:5  
对3G用户接入时的认证鉴权进行分析和研究,介绍了3G的安全体系结构,详细分析了3G的认证和鉴权机制和过程、用户信息的加密和完整性保护的过程和方法、密钥协商机制,并指出了3G认证鉴权机制可能存在的缺陷,最后对2G和3G的互通方面的安全性和2G与3G安全上下文之间转换运算的算法进行了分类和剖析。  相似文献   

13.
This paper presents a systematic review of models and methodologies that integrate information and communication technologies (ICT) and education. The systematic review was based on the methodology of Kitchenham. The steps used and developed correspond to the steps proposed in the methodology. The starting point of the review are the research questions, then keywords, selection of the databases, definition of the inclusion and exclusion criteria, the definition of the search chains, search process and selection of papers, the analyzes of the paper and the results of the systematic review to answer the questions posed. In the systematic review, 919 papers were found in 6 academic databases and 129 relevant papers were selected. The work developed intends to know the different models and methodologies that integrate the ICT and the education. Develop an analysis and characterize to find common elements among models and methodologies. The idea is to find limitations, disadvantages and spaces that allow to propose a new model. This systematic review is the first step in the development of a doctoral research in which the development of a U-Learning model based on Connective Learning and Experience Learning is proposed.  相似文献   

14.
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   

15.
小信号多腔速调管主要性能指标简化分析   总被引:1,自引:0,他引:1  
宁曰民 《微波学报》2005,21(3):43-47
介绍了速调管在我国的发展现状和小信号条件下速调管的各种主要性能指标的简化分析方法。在这种简化分析方法中,首先不考虑非线性和相对论效应等带来的影响,并把多腔速调管看作是几个双腔速调管的级联,得出了增益、效率、带宽和输出功率等重要参数的计算公式。然后通过给出部分参数的修正系数说明了这种简化分析方法的实用价值及理论指导意义。  相似文献   

16.
以S3C2440为平台,实现了S3C2440单板机对智能模拟人的控制箱,按压和通气功能的控制,以及S3C2440与上位机通信功能,通过对内核的裁剪和驱动及控制程序的编写,不仅可以实现各种控制箱的操作,而且也可以对模拟人的按压和通气模拟操作功能进行控制,产生与之对应的各种模拟反应。最后,提出了用设置加权系数的办法解决按压和通气控制条反应速率过缓问题。  相似文献   

17.
王鹏周政 《微波学报》2012,28(S2):361-363
GPS 卫星定位技术已广泛应用于航空航天系统。本文通过阐述GPS 接收机的工作原理及GPS 信号的特点,分 析了接收机交调互调传导敏感度测量原理,扩展了GPS 接收机交调互调传导敏感度的试验方法。该测试方法快捷、易 于掌握,便于得到接收机互调交调抑制比参数。  相似文献   

18.
直流电源输出的纹波和噪声的测量   总被引:1,自引:0,他引:1  
对于直流电源纹波和噪声的测量,不同的测量方法测量的结果往往差别较大。针对这个问题,本文先介绍了电源输出的纹波和噪声的基本概念,并在此基础上介绍了三种常见的纹波和噪声的测量方法:直接测量的方法、去掉探头和探头接地线的测量方法和使用同轴电缆的测量方法。通过分析、比较,阐明了不同测量方法之间的区别,明确了对示波器的要求及测量的注意事项,以使大家能够根据具体情况选用适宜、方便的测量方法,准确地测量到直流电源输出的纹波和噪声。  相似文献   

19.
This paper describes the design and implementation of a hybrid intelligent surveillance system that consists of an embedded system and a personal computer (PC)-based system. The embedded system performs some of the image processing tasks and sends the processed data to the PC. The PC tracks persons and recognizes two-person interactions by using a grayscale side view image sequence captured by a stationary camera. Based on our previous research, we explored the optimum division of tasks between the embedded system and the PC, simulated the embedded system using dataflow models in Ptolemy, and prototyped the embedded system in real-time hardware and software using a 16-bit CISC microprocessor. This embedded system processes one 320 × 240 frame in 89 ms, which yields one-third of the rate of 30 Hz video system. In addition, the real-time embedded system prototype uses 5.7 K bytes of program memory, 854 K bytes of internal data memory and 2 M bytes external DRAM. Koichi Sato is a Ph.D. student in the Department of Electrical and Computer Engineering at The University of Texas at Austin. He earned his B.S. in University of Tokyo, Japan in 1993. He worked for Automotive Development Center in Mitsubishi Electric Corporation where he was involved in lane and automobile recognition in vehicle video processing products such as automatic cruise control and drowsiness detection systems. He enrolled in the current University at 1998 and received an M.S in 2000. In his Master's thesis he worked on human tracking and human interaction recognition. His current work includes velocity extraction using the TSV transform, object tracking, and 3D object reconstruction. Brian L. Evans is a tenured Associate Professor in the Department of Electrical and Computer Engineering at The University of Texas at Austin. His research and teaching efforts are in embedded real-time signal and image processing systems. In signal processing, his research group is focused on the design and real-time software implementation of ADSL and VDSL transceivers, for high-speed Internet access. In image processing, his group is focused on the design and real-time software implementation of high-quality halftoning for desktop printers, smart image acquisition for digital still cameras, and 3-D sonar imaging systems. In signal and image processing, Dr. Evans has published over 100 refereed conference and journal papers. Dr. Evans is the primary architect of the Signals and Systems Pack for Mathematica, which has been on the market since October 1995. He was a key contributor to UC Berkeley's Ptolemy Classic electronic design automation environment for embedded systems, which has been successfully commercialized by Agilent and Cadence. His BSEECS (1987) degree is from the Rose-Hulman Institute of Technology, and his MSEE (1988) and PhDEE (1993) degrees are from the Georgia Institute of Technology. From 1993 to 1996, he was a post-doctoral researcher in the Ptolemy project at UC Berkeley. He is a member of the Design and Implementation of Signal Processing Systems Technical Committee of the IEEE Signal Processing Society, and a Senior Member of the IEEE. He is the recipient of a 1997 National Science Foundation CAREER Award. J.K. Aggarwal has served on the faculty of The University of Texas at Austin College of Engineering since 1964 and is currently Cullen Professor of Electrical and Computer Engineering and Director of the Computer and Vision Research Center. His research interests include computer vision and pattern recognition focusing on human motion. A Fellow of IEEE since 1976 and IAPR since 1998, he received the Senior Research Award of the American Society of Engineering Education in 1992, the 1996 Technical Achievement Award of the IEEE Computer Society and the graduate teaching award at The University of Texas at Austin in 1992. He has served as Chairman of the IEEE Computer Society Technical Committee on Pattern Analysis and Machine Intelligence (1987--1989); Director of the NATO Advanced Research Workshop on Multisensor Fusion for Computer Vision, Grenoble, France (1989); Chairman of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition (1993), and President of the International Association for Pattern Recognition (1992--1994). He is a Life Fellow of IEEE and Golden Core member of IEEE Computer Society. He has authored and edited a number of books, chapters, proceedings of conferences, and papers.  相似文献   

20.
胆小管超微细胞酶学研究   总被引:1,自引:0,他引:1  
以电镜细胞化学的方法,观察了小鼠胆小管酶的分布。观察的12种酶中,NDPase和G6Pase三种酶分布于胆小管微绒毛;AlPase、Na~+-K~+ATPase、Mg~(++)-ATPase、Ca~(++)-ATPase、CMPase、ACase和5'-Nase等7种酶分布于胆小管微绒毛,也分布于肝细胞邻接面细胞膜和Disse间隙微绒毛;ACPase、细胞色素氧化酶以及线粒体ATPase不分布胆小管微绒毛,也不分布Disse间隙微绒毛和肝细胞膜。据信,胆小管微绒毛上的酶参与胆汁成份的转运,提供转运所需能量以及还可能与某些代谢过程有关。本实验中磷酸水解酶类使用的铈基法及亚铁氰化钾半还原的锇酸后固定法,效果优于铅法。  相似文献   

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