基于奔迈Palm OS的无线点餐系统开发

个人数字助理(PDA)在近几年得到了很大的发展.Palm作为该领域的开拓者,不断推出新品,在该领域继续取得了优异的成绩,拥有广阔的市场.Palm的产品技术成熟,反应速度快,完全可以胜任该领域内的所有任务.Palm OS以其速度高的特点,足以应付食肆高峰期的负荷,大大提高餐厅的工作效率. 无线点餐餐厅利用PDA的无线连接能力,实现服务员在客人点餐之后,餐厅相关部分马上得到点餐信息的技术.因为新的PDA具有多种无线接口,并具有相当强大的运算处理能力,完全可以利用PDA完成点餐的任务.     

印刷水印研究的新进展及应用

印刷水印在印刷作品的安全和图像的版权保护的方面起着重要的作用.由于印刷作品在打印扫描过程中经历攻击的复杂本质,现有印刷水印的研究尚未取得实质性的成果.因此,印刷水印的研究仍是信息安全领域挑战性极强的方向.本文首先从印刷水印遭受攻击的角度,指出了印刷水印实现的难点,接着探讨了新的典型的印刷水印的设计和实现,然后给出了新的印刷水印的研究成果和性能评价,最后展望了印刷水印的深入研究的方向和应用前景.     

全程实时程线的冷链NEC的RFID解决方案帮助泰凌实现了国内领先的冷链管理系统

冷链必须是全程的 实时的 作为国内拥有雄厚实力的进口疫苗分销商,泰凌医药集团旗下的海南泰凌生物制品有限公司肩负着一些垒球知名厂商的疫苗产品在中国的分销和冷链配送服务.每当看到专用的冷藏车将一箱箱的疫苗运送到仓库的时候,泰凌人的心中感受到更多的是责任.     

BSIM Model Research and Recent Progress

CMOS集成电路技术的进一步发展和不断出现的新技术应用要求我们持续地改进和增强VLSI电路设计和模拟的集约模型.基于此,美国Berkeley加州大学的BSIM团队对国际工业标准芯片仿真物理模型BSIM进行了一系列的研究和发展工作.本文分析和介绍了最近几年来本人参与其中的BSIM工程的研究和进展情况,包括BSIM5的研究,BSIM4的增强和BSIMSOI的发展.BSIM5是为满足RF和高速CMOS电路模拟要求而发展的新一代物理基础的BSIM模型,具有对称、连续和参数少的特点.BSIM4是一个成熟的工业标准仿真模型,在衬底电阻网络、隧穿电流、饱和电流原理和应力模型等方面有一系列的功能增强以支持技术进步的需求.BSIMSOI已经发展成可应用于SOI-PD和SOI-FD技术的普适模型,通过有效体电势△Vbi的改变进行器件工作模式的选择,可以帮助电路设计者实现PD和FD共存的设计趋势.     

Web安全测试及对策研究

随着WEB应用程序在更广泛范围的使用及WEB工程概念的提出,Web安全的测试就成为一项重要的工作.而Internct和Web媒体的不可预见性使得测试变得困难,必须为测试复杂的基于Web的系统研究新的方法和技术.文章在分析WEB系统的布署环境,应用程序,数据库和系统容错等方面存在安全漏洞的基础上,对Web安全测试的要点和方法进行了探讨,并对测试中可能发现的问题给出了解决方法.     

DM500S卫星多媒体接收机的GPRS网络共享

Dreambox的GPRS网络共享技术最先是俄罗斯烧友开发的,去年的11月份在国内某卫视论坛开始讨论起来,我国台湾的www543网友率先推出了内含PPP dial拨号功能的Gemini 4.10繁体版,并推出了视频教程,介绍如何通过支持GPRS串口功能的手机连接DM500S的软件设置方法,推动了这股GPRS网络共享的高潮。一些敏锐的小厂嗅到这一技术优势,迅速地推出了基于DM500S的内置GPRS模块。     

依然范特西 松下LUMIX DMC-LX3GK

不知你是否还记得当年风光无限的松下LX2,在为数不多的消费旗舰DC中,它以自己过硬的实力牢牢保持着一席尊位,受到广大用户的好评。漫长的两年之后,松下推出了LX2的替代机型——LX3,梦幻般的徕卡镜头、卓越的维纳斯四代引擎、出色的成像质量,LX系列不追求换代速度,它讲求的只有画质。这款让业界为之一震的小卡片依旧延续着LX系列Fantasy的故事,抒写着消费旗舰DC的新传奇。     

收视价值的迷失 高端人群在远离卫视 2008目睹中国电视之怪现状

近两个月来,本刊网站的论坛里又不太安静。有个叫"高清迷"的香港网友遭到了广东一些网友的质疑。彼此论战的焦点大部分在说香港电视好看或不好看。"高清迷"网友说大陆电视越来越好,水平已经超过香港的电视节目。广东网友们则是缅怀香港电视的辉煌历史。这原本是简单的我说你好你说我好,互相捧场的事情,但是网络的奇妙性在于事情并没有朝积极的方向发展,其结果是吵架不可避免的发生了。外来的和尚是不是会念经,我们先不去管他。重要的是我们要弄清楚自己是怎么回事。本文,是专业电视人对我国各省卫视台做的调查评估。让我们了解一下我国的电视台的现状吧。     

ADSL服务

现在使用ADSL上宽带网的用户是越来越多了,对ADSL设备的维护也成了一个不容忽视的问题.只有维护保养好它,不但让你的"宽带之旅"省心又省力,还能延长其寿命.ADSL的维护可分为软件和硬件两个方面来分析,软件主要是PPPOE协议的问题,和计算机本身的气操作系统,和网卡方面的事情.硬件主要是局端的节点设备,和用户端猫的问题.还有通信的线路等一些因素.     

“天地一体”不再是梦——访IPSTAR宽带卫星北京办事处

在抗震救灾的相关报道中,人们排队等待拨打卫星电话,从而取得与家人联系的画面引起了很多人的关注。因为在地震之后,灾区的通信系统一度中断,如何把灾区的受灾情况真实的反馈出来,如何让灾区的同胞尽快了解到亲人的下落成为了全国人民的心愿。也正是在这个时候,很少受到关注的卫星通讯系统走进了人们的视野,正是通过它,我们才及时了解到了那些重灾区的受灾情况。2008年5月12日,发生在四川省汶川县的大地震给那里的同胞们带来了巨大的灾难。地震给当地人民的生命财产造成了难以估量的损失,特别是地面通讯基站遭到了严重破坏,一时间灾区的通讯系统几乎处于瘫痪状态。人们焦急万分,在这危急关头,海事卫星电话等卫星通讯设备架起了灾区与外界信息沟通的桥梁。面对着堰塞湖可能溃坝的危险,一个名叫IPSTAR的宽带卫星视频监控系统也在这一时间引起了人们的极大关注。带着对IPSTAR以及我国的卫星通讯事业发展走势的期待,记者于近日走访了IPSTAR卫星北京办事处,在那里记者了解到了与之相关的诸多情况。     

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。     

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.     

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.     

1xEV-DO与HSPA无线接入技术对比

HSPA与1xEV-DO具有相同的目的和基本相同的技术实现手段,本文主要对1xEV-DO与HSDPA从标准演进、关键技术、网络结构与性能、商用情况等方面进行了全面的对比分析。     

Graphene‐Based Nanomaterials: Synthesis,Properties, and Optical and Optoelectronic Applications

Graphene, a two‐dimensional, single‐atom‐thick carbon crystal arranged in a honeycomb lattice, shows extraordinary electronic, mechanical, thermal, optical, and optoelectronic properties, and has great potential in next‐generation electronics, optics, and optoelectronics. Graphene and graphene‐based nanomaterials have witnessed a very fast development of both fundamental and practical aspects in optics and optoelectronics since 2008. In this Feature Article, the synthesis techniques and main electronic and optical properties of graphene‐based nanomaterials are introduced with a comprehensive view. Recent progress of graphene‐based nanomaterials in optical and optoelectronic applications is then reviewed, including transparent conductive electrodes, photodetectors and phototransistors, photovoltaics and light emitting devices, saturable absorbers for ultrafast lasers, and biological and photocatalytic applications. In the final section, perspectives are given and future challenges in optical and optoelectronic applications of graphene‐based nanomaterials are addressed.     

开放和分解OTN网络技术研究和分析

如何构建开放和分解的OTN网络,以实现跨厂家设备的混合组网和光层互连,一直是运营商和设备商追求的目标,ONF和LFN这两大开源项目组织分别基于各自的SDN控制平台——ONOS和OpenDayLight,给出了自己的解决方案——ODTN+TAPI和OpenROADM+TPCE,本文对这两种技术方案作了深入的研究和分析,比较了这两种技术的异同点,并对当前这两种技术的发展和应用前景作了简要的说明。     

基于AdaBoost的音乐情绪分类

随着流媒体应用的蓬勃兴起,音频信号的自动分类开始成为工程与学术关注的热点之一。根据音乐信号对乐曲表现的情绪进行分类,由于涉及音乐信号的社会属性和自然属性的综合表征与模糊分类,因此处理方法相应需要在各种传统表征与分类方法的基础上进行机制筛选与架构优化。该文探讨了在AdaBoost算法,K-L变换和GMM模型的基础上构造弱分类器的方法,采用多层分类器结构,成功地实现了对音乐信号进行情绪分类。初步的实验对163首歌曲进行平静(Calm),悲伤(Sad),激动(Exciting)以及愉悦(Pleasant)4种类别的分类,训练集和测试集的分类准确率分别达到97.5%和93.9%,展示了这种方法的可行性和进一步发展的潜在价值。