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。     

上海慕尼黑电子展暨同期展会见闻

2007年3月21日～23日的上海新国际博览中心是格外的热闹,超过2万名来自电子行业的专业观众汇聚与此.吸引他们来到这里的原因就是慕尼黑上海电子展,慕尼黑上海激光、光电展(LASER. World of Photonics China)、中国国际半导体设备、材料、生产和服务展览暨研讨会(SEMICON China),以及中国国际电子电路展览会(CPCA Show)四大电子业权威品牌展联合在此举行.     

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.     

命题逻辑中代数学的影子

命题逻辑是一个以命题为基本研究对象的数学化的逻辑系统,命题逻辑是数理逻辑的基础,也是计算机科学与技术的理论基础.为了深入理解命题逻辑,将命题逻辑与一般的代数学进行比较,从6个方面简要总结和论述命题逻辑中代数学的一些思想和方法,使得读者能从中体会到代数学的一些思想和方法在命题逻辑中的应用.     

不一样的热插拔(hot swap)控制器

引言 热插拔(hot swapping)的定义是从一块正在通电运作中的背板(backplane)上插入或移除电路板.这项技术被广泛应用在电信服务器(telecom servers)、USB界面、火线(firewire)界面和 CompactPCI应用等[参考1].这种技术可在维持系统背板的电压下,更换发生故障的电路板,而同时系统中其它正常的电路板仍可保持运作.     

从跨国公司CEO扎堆访华说起

11月1日,似乎是个好日子!来自英特尔、EMC、思科的3位跨国公司CEO均选在这一天访华,并宣布其在中国市场大手笔的战略投入. 11月2日,来自全球最大显卡芯片厂商NVIDIA公司的联合创始人、总裁兼CEO黄仁勋借访华之际,在清华大学美术学院报告厅进行了"GPU--还原一个真世界"的演讲.     

FEW-NNN: A Fuzzy Entropy Weighted Natural Nearest Neighbor Method for Flow-Based Network Traffic Attack Detection

Attacks such as APT usually hide communication data in massive legitimate network traffic, and mining structurally complex and latent relationships among flow-based network traffic to detect attacks has become the focus of many initiatives. Effectively analyzing massive network security data with high dimensions for suspicious flow diagnosis is a huge challenge. In addition, the uneven distribution of network traffic does not fully reflect the differences of class sample features, resulting in the low accuracy of attack detection. To solve these problems, a novel approach called the fuzzy entropy weighted natural nearest neighbor(FEW-NNN) method is proposed to enhance the accuracy and efficiency of flowbased network traffic attack detection. First, the FEW-NNN method uses the Fisher score and deep graph feature learning algorithm to remove unimportant features and reduce the data dimension. Then, according to the proposed natural nearest neighbor searching algorithm(NNN_Searching), the density of data points, each class center and the smallest enclosing sphere radius are determined correspondingly. Finally, a fuzzy entropy weighted KNN classification method based on affinity is proposed, which mainly includes the following three steps: 1、 the feature weights of samples are calculated based on fuzzy entropy values, 2、 the fuzzy memberships of samples are determined based on affinity among samples, and 3、 K-neighbors are selected according to the class-conditional weighted Euclidean distance, the fuzzy membership value of the testing sample is calculated based on the membership of k-neighbors, and then all testing samples are classified according to the fuzzy membership value of the samples belonging to each class;that is, the attack type is determined. The method has been applied to the problem of attack detection and validated based on the famous KDD99 and CICIDS-2017 datasets. From the experimental results shown in this paper, it is observed that the FEW-NNN method improves the accuracy and efficiency of flow-based network traffic attack detection.     

追日

去年10月一个温暖的早晨,在澳大利亚内陆深处,14名麻省理工学院的学生和校友上午6点就爬出了他们的睡袋,准备车队,进行又一天的艰苦驾驶,在护卫队的护送下,他们驶过一段平坦、笔直、炎热、灰尘弥漫的道路.领头的车辆迎着其他车流,形成了一个缓冲带,一辆货车断后以监测整个队伍的进程.     

Design of Diode Type Un-Cooled Infrared Focal Plane Array Readout Circuit

The diode infrared focal plane array uses the silicon diodes as a sensitive device for infrared signal measurement. By the infrared radiation, the infrared focal plane can produces small voltage signals. For the traditional readout circuit structures are designed to process current signals, they cannot be applied to it. In this paper,a new readout circuit for the diode un-cooled infrared focal plane array is developed. The principle of detector array signal readout and small signal amplification is given in detail. The readout circuit is designed and simulated by using the Central Semiconductor Manufacturing Corporation (CSMC) 0.5 μm complementary metal-oxide-semiconductor transistor (CMOS) technology library. Cadence Spectre simulation results show that the scheme can be applied to the CMOS readout integrated circuit (ROIC) with a larger array, such as 320×240 size array.     

农村有线电视网络常见故障

（1）原来转播的中央1套节目变成了中央2套。检查机柜正常．调出菜单发现原设定的频率1290变为970，其他节目正常。重新调整频率，节目恢复正常，分析其原因为接收一体机内部集成块出现误码导致原储存的数据发生变化。     

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.     

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。     

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.     

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。     

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。     

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.     

Status and Trends in Advanced SOI Devices and Materials

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.     

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.     

Alternative Schemes for Dynamic Secure VPN Deployment in UMTS

Three alternative schemes for secure Virtual Private Network (VPN) deployment over the Universal Mobile Telecommunication System (UMTS) are proposed and analyzed. The proposed schemes enable a mobile node to voluntarily establish an IPsec-based secure channel to a private network. The alternative schemes differ in the location where the IPsec functionality is placed within the UMTS network architecture (mobile node, access network, and UMTS network border), depending on the employed security model, and whether data in transit are ever in clear-text, or available to be tapped by outsiders. The provided levels of privacy in the deployed VPN schemes, as well as the employed authentication models are examined. An analysis in terms of cost, complexity, and performance overhead that each method imposes to the underlying network architecture, as well as to the mobile devices is presented. The level of system reliability and scalability in granting security services is presented. The VPN management, usability, and trusted relations, as well as their behavior when a mobile user moves are analyzed. The use of special applications that require access to encapsulated data traffic is explored. Finally, an overall comparison of the proposed schemes from the security and operation point of view summarizes their relative performance. Christos Xenakis received his B.Sc. degree in computer science in 1993 and his M.Sc. degree in telecommunication and computer networks in 1996, both from the Department of Informatics and Telecommunications, University of Athens, Greece. In 2004 he received his Ph.D. from the University of Athens (Department of Informatics and Telecommunications). From 1998–2000 was with the Greek telecoms system development firm Teletel S.A., where was involved in the design and development of advanced telecommunications subsystems for ISDN, ATM, GSM, and GPRS. Since 1996 he has been a member of the Communication Networks Laboratory of the University of Athens. He has participated in numerous projects realized in the context of EU Programs (ACTS, ESPRIT, IST). His research interests are in the field of mobile/wireless networks, security and distributed network management. He is the author of over 15 papers in the above areas. Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Greece, in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981 and 1984, respectively. From 1983 to 1986, he was on the faculty of Electrical Engineering and Computer Science at the University of Connecticut, Storrs. From 1986 to 1994 he was on the faculty of the Electrical and Computer Engineering Department at Northeastern University, Boston, MA. During the period 1993–1994 he served as Director of the Communications and Digital Processing Research Center at Northeastern University. During the summers of 1990 and 1991, he was a Visiting Scientist at the IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens, Greece, where he is presently a Professor in the Department of Informatics and Telecommunications, and Director of the Communication Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. His research interests are in the design and performance analysis of broadband networks, and wireless/mobile communication systems and services. He has authored more than 150 papers in the above areas. Since 1995, he is leading the research activities of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies & Services (ACTS) and Information Society Technologies (IST) programmes funded by the European Union (projects RAINBOW, Magic WAND, WINE, MOBIVAS, POLOS, ANWIRE). He is chairman of the board of the Greek Universities Network, the Greek Schools Network, and member of the board of the Greek Research Network. In 1994, he received the Guanella Award for the Best Paper presented at the International Zurich Seminar on Mobile Communications.     

卫星通信组呼业务MAC层研究

组呼通信在指挥调度中有着重要作用,而在一些地面没有基站的地方,就无法正常使用。卫星通信具有无视地形,通信范围广,不易受陆地灾害影响,易于建设等优点。把卫星通信和组呼通信结合在一起的卫星组呼通信技术兼顾两者的优点,能更好的发挥指挥调度这一作用。当前卫星组呼通信采用固定频率方式,组呼成员在一个频率下进行通信,这种方式实用性不好。本文研究的是移动卫星组呼,在GMR-1系统的基础上研究了卫星组呼通信中MAC层的功能,提出了MAC-Ready-Gcc、MAC-Dedicated-Gcc这两个为了支持组呼的状态,并针对在MAC层发生的PTT竞争提出了一种回退策略。