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1.
李春晓 《电子测试》2014,(Z2):53-54
科学技术的发展现在一个国家的发展中显的极为的重要,对于科学技术的研究是体现一个国家的综合国力的表现,本文主要针对LISA数据库收录的有关云计算机的文献进行的研究,通过这些的研究分析来关注它的起源,发展历程极其研究的最新动态。并且在一定的范围内探讨出在以后的研究道路上的目标以及我们应该注意的问题。  相似文献   

2.
城市发展的好与坏与城市的设计规划有着巨大的联系,这是不容置疑的,发展好的城市的规划设计就是要比其他城市的规划设计更加的合理。但是在这个城市遍地的时代,不是所以的城市都发展的很好,这主要就是城市的设计规划的不同所导致的,譬如:城市中的道路;建筑;楼房的建设;环境的创建等,这些东西的不同直接导致了两个城市的发展结果截然不同,这就说明城市规划对城市的发展是有很大的意义的。  相似文献   

3.
网络的规划及计算机的维护工作主要涉及到了计算机的软硬件的管理及维护的工作还有网络的相应的规划和管理的工作,此外还有中心机房的规划和布置的相关的内容以及计算机的外部设备相应的维护及管理的工作等内容。本文就局域网的建设和维护工作做了很好地分析,并针对其中的问题提出了很好地建议。  相似文献   

4.
我国的数字卫星电视经过了一个漫长的发展才达到了目前的程度,有效的提高了我国人民的能够收看到的电视品质,本文从我国早期的的卫星电视与我国卫星电视的数字化过程对我国的数字卫星电视的发展做出了一定的论述。  相似文献   

5.
对于宁波大学的体育馆的扩声系统的设计进行了详细的介绍.考虑到体育馆内部的空间大,混响时间长的建筑结构的缺陷.在吊顶上采用了大量的吸声体解决了混响时间过长的问题.同时,采用集中式的阵列扬声器的布局模式解决了声压级的覆盖以及对语言清晰度要求的矛盾.同时在系统中采用了大量的数字音频处理器设备简化了系统的结构,提高了系统的可靠性.  相似文献   

6.
2010年的国产鸿篇巨制<孔子>,以强大的演员阵容,扣人心弦的故事情节,具有和谐思想的人性解读,再现出中国二千五百年前的春秋争霸以及一位"去圣"的凡人颠沛流离的晚年生活.视听震撼之外,是灵魂深处的碰撞:天下大同的圣人思想、仙境岸边的子见老子、虔诚执着的门徒弟子,灰飞烟灭的红颜知己,颠沛流离的晚年生活、皓首苍颜的衰老终回……从人心的最深处不断敲打的人性的灵魂.  相似文献   

7.
随着人们建筑工程的质量的要求的不断的提高,建筑工程的质量的检测技术在也在不断的发展和受到人们越来越多的重视。在建筑施工的过程中的建筑工程的质量的控制和监督是影响工程的整体质量的一个关键的因素。在建筑的工程质量检测的过程中要对工程的工期和工程建设质量检测人员的素质等的因素进行严格的控制和管理,以保证工程的质量的合格。  相似文献   

8.
随着时代的飞速发展,科技的不断进步,人们越来越意识到虚拟现实的重要作用,校园是培养人才的地方,如何给学生更好地学习环境,更好的保障学生在上学时的安全,更加有效地提高学生学习的效率,都是可以通过虚拟现实的技术得以实现的。人们通过虚拟现实的技术,更好的更直观了解校园中一些具体的情况,获取相应的信息,以往仅仅只是对校园环境的模拟已经无法满足人们的需求,人们需要教学,教务,校园生活三者相结合的一种虚拟校园的出现,而目前的科学技术已经足以实现这样的效果,真实性,互动性,有着特有的情节是虚拟技术的一个很重要的表现形式。  相似文献   

9.
传统的无线通信系统空中接口的高层协议采用简单的分层结构,每层进行独立的设计和操作,各层间的接口是静态的。这种设计方法简化了网络设计,具有很好的通用性,但是无线通信系统的信道是随着时间、空间和频率而随机变化的,同时用户的多媒体业务和整个网络状态也是动态的、变化的,而传统的分层协议结构不能很好的适应无线通信的特点,不能保证用户多媒体业务的QoS(服务质量),传输的可靠性和提高无线资源的利用率,本文针对此问题阐述了跨层无线资源管理的思想,跨层设计能够根据用户多媒体业务的QoS和信道的随机变化特性等,跨过层间功能进行优化,更好的保证了不同多媒体业务的QoS,利用各个用户间信道的独立随机变化的特性,最大化系统的传输效率。  相似文献   

10.
传统的传输数据的方式是应用有线的方式。传统的数据信息的传输方式存在一定的弊端,在这些弊端的存在以及时代的发展之下,我们进入了无线的时代。数据信息于无线传输的采集与控制的方式具有速度快,噪音小、效率高等优点,给我们的生活带来了巨大的便利。  相似文献   

11.
A doping system consisting of NPB and PVK is employed as a composite hole transporting layer (CHTL). By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK : NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK : NPB at 1:3.  相似文献   

12.
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.  相似文献   

13.
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   

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.
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   

16.
电磁兼容测试结果与检测实验室可靠性程度直接相关,检测实验室自身质量是保证电磁兼容测试结果准确性先决条件,检测实验室测试系统相符性则成为电磁兼容系统性能评估中需要考虑的关键内容和重要指标。因此,检测实验室测试系统相符性比对是实现电磁兼容系统评估研究的基础工作之一。本文首先针对电磁兼容检测实验室测试系统相符性比对的特点,结合自己几年来的测试实践论述了电磁兼容检测实验室测试系统相符性对比方案,然后提出了具体的案例同时进行了详细的分析,最后总结出了影响电磁兼容检测实验室测试系统相符性因素,整个案例和分析过程及结果可作为电磁兼容检测实验室测试系统相符性比对的手段和依据,具有重要的现实指导意义。  相似文献   

17.
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   

18.
This paper presents a unified treatment of various important signal processing techniques for the extraction of the instantaneous envelope and phase of a real signal. These techniques include Complex Demodulation, Hilbert Transformation, In-Phase and In-Quadrature Filtering, Phase-Locked Loop Demodulation, and Peak Amplitude and Zero-Crossing Detection. The salient points in the mathematical theory and implementation of these techniques are outlined, as well as their interrelationships via the theory of analytic signals. The advantages and limitations of each of these techniques are elaborated upon, and Complex Demodulation is shown to be the most effective and flexible method from an implementation point of view. The relation of the above techniques to Fourier spectrum analysis is elucidated, and an example is presented of applying Complex Demodulation for the quantification of time nonstationarities in the electrographic morphology of an EEG waveform.  相似文献   

19.
在通信系统中,伪随机码应用十分广泛,其优点是抗干扰能力强,保密性好。在比较两种伪随机码产生方法的基础上,分析了应用伪随机码的EAS(Electronic Article Surveillance)系统的优点:抗干扰能力强和多系统协调工作性能好。同时,提出一种以伪随机特征码为纽带的多个EAS系统一起工作的协调方式。然后,通过对现有EAS系统不足点的分析,提出了新的检测信号有效性的判断依据,即信号的测量值与平均值的偏差是符合高斯分布的,以及相应的评判方法,即计算信号测量值与平均值的偏差,如果测量偏差大于某个城值,则触发一个报警。由此,进一步详细阐述了将伪随机码技术应用于EAS系统的具体方法及其抗干扰能力。  相似文献   

20.
郭勇 《电子科技》2005,(7):57-60,64
对于下一代网络(NGN),如何保障端到端的服务质量(QoS)是NGN的核心问题之一,直接影响着NGN业务的提供.该文给出了NGN的网络体系结构和业务特点,针对其对服务质量的要求,探讨了在NGN中实现QoS的框架模型,着重介绍了几种实现端到端QoS保障的关键技术,分析了它们各自的特点和存在的问题.  相似文献   

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