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1.
一种快速有效的帧级码率控制算法   总被引:3,自引:1,他引:2  
贺军 《电视技术》2003,(9):14-16,23
基于对码率控制算法的研究,取H.263 的TMN8码率控制算法和DivX的平均码率控制算法之长,提出了一种新型帧级码率控制算法,给出了实现算法的步骤和软件流程,实验表明该码率控制算法快速、简便、有效,并可将它应用于视频监控系统中。  相似文献   

2.
灰色预测控制的设计及其应用   总被引:8,自引:0,他引:8  
介绍一种灰色预测控制算法,它以灰色系统理论为基础,利用灰色预测模型实时调整PID控制参数,从而从根本上解决单一PID控制算法的局限性。灰色预测控制算法通过8098单片机实现,并在实际应用中获得良好的控制效果。  相似文献   

3.
基于重复控制的高精度平台控制系统设计   总被引:1,自引:0,他引:1  
针对传统PID控制算法的局限性,本文提出了一种基于重复控制的雷达平台控制系统的设计,给出了将重复控制算法引入PID闭环控制系统的实现方法。应用结果表明,在雷达平台控制系统中引入重复控制算法,可改善系统的控制品质,使系统的跟踪控制精度能有很大的提高。  相似文献   

4.
刘明阳  郑晨  张昂  蔡悟洋 《现代导航》2020,11(4):268-271
针对轮式机器人轨迹跟踪控制问题,提出了一种轨迹跟踪控制算法。通过对轮式机器人进行运动学分析,建立了运动学模型来描述其在水平面内的运动规律;提出了轨迹跟踪控制算法,并对迹跟踪控制算法进行仿真试验,直线轨迹跟踪的纵向偏差 0.09m,横向偏差 0.06m, 航向角偏差 3.7°;曲线轨迹跟踪的纵向偏差 0.13m,横向偏差 0.09m,航向角偏差 5.1°。仿真试验结果表明本研究所设计的轨迹跟踪控制算法具有良好的动态响应,可以支撑实际应用。  相似文献   

5.
王兵  叶栋  丁炜 《通信学报》2003,24(5):121-128
分析了呼叫接纳控制算法研究的现状,提出一种适应自相似业务流量模型的呼叫接纳控制算法,在接纳判决过程中引入概率接纳机制。理论分析和仿真结果验证了算法的可行性和在自相似业务流量模型下相对于传统呼叫接纳控制算法的优越性。  相似文献   

6.
基于80C51单片机的智能PID控制器的设计与实现   总被引:2,自引:0,他引:2       下载免费PDF全文
吴占雄  王友钊   《电子器件》2006,29(3):972-975
PID控制技术在工业控制中的应用非常广泛。然而,在实际过程中被控对象常常比较复杂,具有非线性、不确定性,很难为之建立精确的数学模型,对之应用传统的PID控制算法,不能达到理想的控制效果。本文在传统PID控制算法的基础上,结合人工智能的方法,设计了多模式PID控制算法;而且基于80C51单片机实现了该PID控制器,在实践中得到了较传统PID控制器优越的控制性能。  相似文献   

7.
会议电视系统比特率控制方法的研究   总被引:1,自引:0,他引:1  
会议电视系统中核心部分是比特率的控制方法,它对编码的图象质量产生直接影响。文中从缓冲器平滑波动数码流的原理入手,分析了缓冲器纯占有率控制算法及参数设置,并针对缓冲器纯占有率控制算法的编码图象质量不够理想的机理,研究了缓冲器占有率的视觉调整算法和基于比特分配的缓冲容量控制算法,并对三种算法进行了比较和论证。  相似文献   

8.
基于人工神经元的PID控制顺的仿真研究   总被引:1,自引:1,他引:0  
采用基于神经元的自学习控制算法对被控对象进行跟踪仿真研究,给出相应的控制算法,并对横摇信号进行跟踪仿真,结果表明这种算法既可取得较好的控制品质,又能避免常规PID控制参数不易实时调整的缺点。  相似文献   

9.
施琴  李玉柏 《通信技术》2007,40(11):10-11,24
文中介绍了高速下行链路分组接入技术(HSDPA)的高速共享控制信道(HS—SCCH)的一种功率控制算法:基于信道质量指示(CQI)的功率控制算法.介绍了该算法的原理:通过计算机仿真,分析了该算法的性能.从仿真结果可以看出,基于CQI的HS-SCCH功率控制算法适用于HSDPA。  相似文献   

10.
面向无线ad hoc网络的一种平面t-支撑图   总被引:2,自引:0,他引:2  
李铭  卢锡城  彭伟 《通信学报》2005,26(6):62-69
拓扑控制算法的目标是为无线ad hoc网络确定合适的底层拓扑。在无线ad hoc网络中,几何路由协议是一类重要的路由协议,为了保证消息转发的可达性和限制路由长度,它要求底层拓扑满足连通性、平面性和稀疏性,并且是原拓扑的t-支撑图。本文提出了一种新的几何结构AUDel图,并提出了两种低通信开销的构造AUDel图的局部拓扑控制算法。理论分析表明,AUDel图满足上述要求,我们提出的拓扑控制算法的通信歼销小于其它构造平面t-支撑图的拓扑控制算法。模拟实验验证了以上结论。  相似文献   

11.
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   

12.
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   

13.
Towards Mobile Ubiquitous Service Environment   总被引:2,自引:0,他引:2  
In this article we present a perspective on future vision of mobile communications and services which is referred to as Mobile Ubiquitous Service Environment (MUSE). Based on analysis of wireless communications and services, we exploit a conceptual model for MUSE via a top-down approach. The conceptual model consists of three major elements: Terminal Service Environment (TSE), Network Service Environment (NSE) and User Identity (UID). The concept of Always the Best Experience (ABE) is addressed as the hinge in design and development such that the user-centric services could be provided automatically and intelligently in the future diverse wireless world Based on these, we further discuss the issues on design and implementation of architecture of future wireless communication system. Requirements for architecture brought by the new features of MUSE are listed. Moreover, we also address several tradeoffs that should be taken into consideration in design. Finally, the deployment challenges for MUSE, such as reflectiveness of system, security and privacy, as well as peer-to-peer AAA are predicted.Ji Yang received PhD degree on Circuit and System, Bachelor degree on Telecommunication Engineering from Beijing University of Posts and Telecommunications (BUPT) in 2002 and 1993 respectively. Currently, he is an associate professor of BUPT, chief technical supervisor of Wireless Technology Innovation Institute, and vice manager of MTlab of Sino-Germany Software Institute. He leads the research on service and application in Future Forum in China. He also made much contribution to the China Communication Standardization Association (CCSA), including the vision of future Mobile Ubiquitous Service Environment, architecture of future B3G mobile terminal, etc. His research interests include architecture design for mobile ubiquitous networks, theory of self-organization, etc.Zhang Ping is now the professor of Beijing University of Posts and Telecommunications and director of Wireless Technology Innovation (WTI) Institute, BUPT. He has also served on the senior member of C3G Group, China MOST 863 future mobile communication FuTURE project, vice-chairman of China FuTURE Forum, and member of Vision Committee of World Wireless Research Forum(WWRF), he was vice chair of WWRF in 2005. He is also invited as the consultants for many domestic and oversea communication companies. He is very active on the international research activity on Beyond 3G area. He also participated in several European projects such as E2R and MOCCA. Until now, he has published 6 books, around 400 publications in journals and conferences in the area of telecommunications. His main research interests are theory and applications in wireless communication area. He was awarded by government, city of Beijing and Ministry of Information Industry several times for his great contribution to the industry and research activity in China.Hu Zheng is a PH.D candidate in mobile communications engineering in Wireless Technology Innovation Institute (WTI) at Beijing University of Posts and Telecommunications (BUPT). He received B.S degree from Nanjing University of Posts and Telecommunications in 2002, majoring in computer communications engineering. He currently works on serivce aspects of mobile ubiquitous communication system with focus on design and performance evaluation of interaction protocols and services in self-organized service environment.Wang Xu received the B.Tech. degree in electronic engineering from Beijing Polytechnic University (now named as Beijing University of Technology), Beijing, China, in 2002. Now he is working for his Ph.D. degree in Wireless Technology Innovation (WTI) Institute, Beijing University of Posts and Telecommunications (BUPT). His current interests include wireless communications in personal area, ad hoc networks and peer-to-peer system.Li Yinong received the BS degree major in Telecommunication Engineering in 1993 from Beijing University of Posts and Telecommunications, the MS degree and PhD degree major in Telecommunication and Electronic System in 1995 and 2003 from the Beijing University of Posts and Telecommunications. He is currently a lecture of STE (School of Telecommunication Engineering) of BUPT. His main research interests include service modeling, service composition approach, and intelligent service. In BUPT, he has given several lectures to both graduate and undergraduate students such as Information Theory, Speech Recognition, Pattern Recognition and Artificial Intelligence.  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.
This paper presents a design of high speed curve interpolating D/A converter. We improve 8-bit data to 12-bit data, so the data resolution increases 16 times than that of original 8-bit data. The curve interpolator is developed from the linear interpolator. The simulation speed curve interpolator is about 500 MHz. The chip is fabricated by 0.8 m double-metal single poly CMOS technology. The active interpolation size of chip is 1 × 1 mm2. The power dissipation is 200 mWatts at 5volt and 500 MHz for simulation result and 80 mWatts at 5 volt and 50 MHz for measurement result. The errors of interpolating result of curve interpolators are about 20 times less than that of original signal.  相似文献   

16.
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   

17.
Pure software HDTV video decoding is still a challenging task on entry-level to mid-range desktop and notebook PCs, even with today’s microprocessors frequency measured in GHz. This paper shows that the performance bottleneck in a software MPEG-2 decoder has been shifted to memory operations, as microprocessor technologies including multimedia instruction extensions have been improving at a fast rate during the past years.Our study exploits concurrencies at macroblock level to alleviate the performance bottleneck in a software MPEG-2 decoder. First, the paper introduces an interleaved block-order data layout to improve CPU cache performance. Second, the paper describes an algorithm to explicitly prefetch macroblocks for motion compensation. Finally, the paper presents an algorithm to schedule interleaved decoding and output at macroblock level. Our implementation and experiments show that these methods can effectively hide the latency of memory and frame buffer. The optimizations improve the performance of a multimedia-instruction-optimized software MPEG-2 decoder by a factor of about two. On a PC with a 933 MHz Pentium III CPU, the decoder can decode and display 1280 × 720-resolution HDTV streams at over 62 frames per second.This work was done while the author was a Ph.D. candidate in the Computer ScienceHan Chen is a research staff member in IBM T.J. Watson Research Center. His research interests include distributed computing systems, scalable display system, and multimedia. He received his Ph.D. degree in 2003 and his M.A. degree in 1999 from Princeton University. He received his B.S. degree from Tsinghua University of Beijing, China in 1997.Kai Li is a Charles Fitzmorris professor at the Computer Science Department of Princeton University. His research interests include operating systems, computer architecture, distributed systems, and scalable display systems. He received his Ph.D. degree from Yale University in 1986. Prior to that, he received his M.S. degree from University of Science and Technology of China, Academy of Sciences of China in 1981 and a B.S. degree from Jilin University in China in 1977. He was a visiting faculty member at University of Toronto in 1988 and a visiting professor at Stanford University during his sabbaticals in 1996 and 2000. He has served on dozens of program committees and served as chair or vice chair several times. He has been elected as an ACM fellow in 1998.Bin Wei received a Ph.D. in Computer Science from Princeton University in 1998 and joined the research community at AT&T Shannon Laboratories since then. His research interests are in the areas of high-performance computer systems, multimedia, and service platforms for mobile users. He received a BS in Computer Science from Tianjin University, China in 1983 and an MS in Computer Science from the Institute of Computing Technology, Chinese Academy of Sciences, in 1989.  相似文献   

18.
提供了一种用于安德鲁反射测量样品制备新方法. 该方法采用聚焦粒子束刻蚀和磁控溅射,可以获得可控的、干净的、无应力的纳米接触用于自旋极化探测. 所制备的样品中,磁性和非磁性材料样品的反射谱都表现出复杂的峰和谷结构,这些结构可能源于与界面相关的零偏压反常以及与激发态相关的准离子相互作用. 对另一个Co40Fe40B20合金样品采用简单的钕针尖压针方法进行了对比性测量,反射谱中没有观察到谷结构,但谱结构出现较明显的热扩展,这种热扩展可能来源于界面处的非弹性输运. 所有的反射谱目前还不能由现有的理论给出令人满意的解释. 利用点接触反射方法获得可靠的自旋极化信息还有赖于接触界面特征的进一步分析. 而一个更切合实际的、更完善的理论成为迫切的需要.  相似文献   

19.
Due to variable symbol length of digital pulse interval modulation(DPIM), it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation(FDPIM) method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.  相似文献   

20.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

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