谈工程测量技术存在的问题及对策分析

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。     

水电站群远程集中控制系统的“五防”功能拓展研究

随着我国的水电站系统不断的发展,远程的集中控制系统也在不断的发展,针对现在我国的水电站的实际情况,为了能够有效的防止远程操作的时候发生事故失误操作,更具电力系统的五防的定义,基于现代意义上的需要在远程的集中控制计算机的监控系统的应用上进行的内涵的扩展,本文的设计实现了计算机的监控系统的五防功能,为了梯级水电站的远程操作的正确性提供了一定的保证。     

浅析配电网线路状态检修存在问题及应对措施

在由于我国的电网建设的不间断发展,从而用电户对于电的要求也将会越来越高,用电户最有效的保证是电网线路的可靠、实在的运用。本文的作者总结出的多年的工作经验,经过对于配电网的线路检修的某个意义做出的简略的描绘,最主要的也就是配电网的线路状态进行的检修中所存在的问题和相应的解决方案做了深入研究,并且也为人们相对的提出一些保障措施。     

对我国动车的发展简述

对于当今社会来说,交通运输的发展趋势是势不可挡的,人们的生活水平不断的提高的同时对出行的要求来越高,铁路运输的发展也要愈来愈适应社会发展的需求。我国的高速铁路面对愈来愈多的竞争与需求,由于动车有诸多优点所以它的发展带动了铁路运输业的飞跃。本文简单的介绍了动车的组成和特点概括性的总结了动车的优缺点,并对动车的产生于使用对其发展进行了大致的分析。     

JR Transrotor王者风范

经典的最大意义在于,它有着真正的价值——这种价值的内涵是丰富的,就音响范畴上的经典而言,它的价值既包括文化意义上的,也包括历史长度上的.最特别的是,与当今在技术发达背景下形成的快速消费型电子产品有所不同,经典的全方位价值始终沉淀在那里.虽然它一时无法在这个热闹的时代成为人们的最高关注,但是,它的那种源远流长的魅力却是无法阻挡的.在这里,我们说的是LP.历史极为悠久的LP有着独属于自己的喜与悲.在最早的讯源时代,它的诞生不仅是划时代的,而且还是受到全球性欢迎的,其所积累起来的声誉使得在很长的一段时间内成为绝对的主角.     

城市设计规划对城市发展的意义

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。     

关于LISA数据库中关于云计算文献的定量分析

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。     

通信工程发展的前景

在现代技术和科学水平的不断推动下,我国的社会主义经济不断的向前发展,为我国各行各业的发展带来了发展的机遇,通讯工程产业就随着科技和经济的发展下,发生了巨大的改变。这种新兴的产业通信工程不仅改善了人们的生活质量,让人们的交流和沟通变得更加的容易,还在一定的程度上促进了经济的整体发展,推动了经济全球化的发展步伐。本文将主要从通信工程具备的特征、通信工程的发展现状以及通信工程的发展前景这三个方面出发对通信工程的发展进行了分析。希望能够依据通信工程的发展前景提前的做好发展的准备工作,更好的规避发展的风险,从而获得更多的产业利润,保证产业的长远发展。只有顺应时代发展潮流的企业才不会被市场所淘汰,只有积极进行改革的企业才能保持长久的生命活力。     

关于对局域网建设与维护的分析

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。     

广播发射系统中的信号冲突消除技术分析

在经济与科技高速发展的今天,为了满足人们对于信息的大量需求,计算机与相应的信息技术充斥在我们衣食住行的方方面面.随着各个领域的应用的加深,也出现了相应的矛盾即计算机技术的快速更替导致的信息的量级的增长,因而多媒体技术的信息检索方法取代了传统的信息检索方法来满足人们对于信息的数量与质量的实际需求.针对广播发射系统中的信息识别问题,尚存在相应的冲突问题.信息在传送过程中因为某一方面的问题导致的信息通道的拥堵,信息滞留导致的系统的效率的降低与稳定性差的问题.本文将就广播发射系统中的信号冲突消除技术进行分析.     

空间互联网技术发展现状及趋势

空间互联网技术是人类进行航天测控、导航定位、远洋航行等空间应用的基础支撑,是实现全球互联互通的关键手段。首先介绍了空间互联网的概念及内涵、组成及结构、特点及优势等相关基础知识,接着总结了空间互联网的关键技术,然后阐述了空间互联网的发展现状和面临的问题,最后结合互联网技术发展趋势和航天应用的发展要求,对空间互联网技术的发展趋势进行了展望和预测。     

高速光纤综合通信网络平台研究

现代通信网络应能满足各种通信业务和通信容量日益发展的需求,实现话音、数据、视频、IP等业务的一体化综合交换和传输。在比较TDM、IP和ATM三种协议的基础上,提出"采用内置RPR和MPLS功能的MSTP平台"建设光纤综合通信网络平台的实现方法。MSTP采用SDH的数据帧结构,保持了SDH标准光接口、灵活分插低速信号、自愈环保护和功能强大的网管等优点,可对TDM、IP和ATM协议进行优化传输。     

Cospas–Sarsat LEO and GEO: Satellite distress and safety systems (SDSS)

Cospas–Sarsat Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) networks must provide enhanced service of Satellite Distress and Safety Systems (SDSS); to improve Search and Rescue (SAR) operations in all environments; and to increase safety and security at low cost for numbers of mobiles at sea, on land and in the air. This paper describes the concepts of integrated LEO and GEO space configurations in function of Cospas (space system for search of distress vessels and airplanes) and Sarsat SDSS, and SAR infrastructures. The paper also reviews satellite repeaters providing SDSS service for satellite beacons known as an Emergency Position Indicating Radio Beacons for Maritime, Personal Locator Beacons for land (road and rail), and Emergency Locator Transmitter (ELT) for aeronautical applications. Copyright © 2007 John Wiley & Sons, Ltd.     

Progress in doping semiconductor nanowires during growth

The anisotropic growth of one-dimensional or filamental crystals in the form of microwires and nanowires constitutes a rich domain of epitaxy and newly enabled applications at different length and size scales. Significant progress has been accomplished in controlling the growth, morphology, and properties of semiconductor nanowires and consequently their device level performance. The objective of this review is two-fold: to highlight progress up to date in nanowire doping and to discuss the remaining fundamental challenges. We focus on the most common semiconductor nanowire growth mechanism, the vapor-liquid-solid growth, and the perturbation of its kinetic and thermodynamic aspects with the introduction of dopants. We survey the origins of dopant gradients in nanowire growth and summarize quantification techniques for dopants and free-carrier concentrations. We analyze the morphological changes due to dopants and the influence of growth droplet seeds on composition and morphology and review growth aspects and alternatives that can mitigate these effects. We then summarize some of the remaining issues pertaining to dopant control in nanowires.     

带SIR结构新型多枝节加载双频滤波器

本文在传统λ/4阶梯阻抗谐振器的基础上,提出了一种新型的宽带双频滤波器改进设计方案。改进的滤波器增加了传输零点,此传输零点能有效的改进通带的选择性和阻带特性,且上阻带带宽很宽。结构简单,在传统类似滤波器同谐振频率基础上有效缩小了尺寸,并且设计的滤波器通带的中心频率和带宽是完全独立可控,方便我们应用到实际。工作在4.1 GHz和6 GHz两个频段,3 dB相对带宽分别为7.2%和2.2%,实测和仿真吻合良好。     

Towards Mobile Ubiquitous Service Environment

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.     

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.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

TD-LTE符号间干扰和载波间干扰分析

ISI和ICI是TD-LTE系统机制固有的干扰现象,也是TD-LTE系统必须消除和抑制的问题。通过对ISI和ICI产生机制及消除方法的定性分析与理论推导,可使广大工程技术人员对TD-LTE系统有全新的认识,为其管理、维护和优化TD-LTE系统提供帮助。     

Rural broadband: Gaps,maps and challenges

This paper examines challenges to evidence-based decision-making in the design and implementation of rural broadband investment programs. Our focus is on Canada, and the apparent need for further intra-rural broadband research and better data and mapping for informing public investment decisions, but similar challenges are evident in the international literature. Based on proprietary telecommunication provider datasets, the Canadian Radio-television and Telecommunication Commission (CRTC) estimates that broadband services with advertised speeds that meet its basic universal service targets (50 Mbps download and 10 Mbps upload) are available to 87.4 percent of households in Canada. In rural areas however, services that meet CRTC’s speed targets are available to 45.6 percent of households. Moreover, effective speeds and service quality levels that suppliers deliver and users experience tend to fall well below the government’s aspirational targets. In response to demand for better broadband, a variety of initiatives are directing public investment to the deployment of regional and rural broadband networks, which are typically owned and operated by private companies. There remains a serious lack of relevant data and its effective use in creating rural broadband strategies and managing public investment projects. Evidence from the literature suggest that this affects the degree and quality of geo-spatial and econometric analysis that results in a limited empirical basis to allocate scarce public investments, aggregate demand of consumers/communities, and assess the outcomes of rural broadband initiatives ex post. This paper provides a historical overview of rural broadband development in Canada and questions if the body of knowledge to inform public investment initiatives has grown sufficiently to ensure their effectiveness and sustainability. With a regional case from southwestern Ontario, Canada, we discuss the findings of the literature review, characterize the broadband data challenge, and discuss the importance of proprietary provider data cross-referenced with Internet user experience data.