通信技术三大跃进和媒体数字化

本文先叙述现代通信技术进展最快的三项 ,即 :硅片集成密度、光纤传输能力、无线通信容量 ,其中特别引人瞩目的是一根光纤的实验传输速率已达 1Tb /s,意味着将使用“奇妙的飞秒”的光脉冲。文中又提到媒体数字化的重要技术 ,这将依靠“朴实的比特”发挥作用。     

构建面向综合业务的有线电视网

有线电视运营商以互联网业务需求采用的CableModem技术作为数据回传手段，已不能满足宽带数据应用和内容对带宽的需求，没有高性能的双向网络是一直制约有线电视网的信息化发展进程的要素。随着数字电视的发展与推广，有线电视网的数字化和信息化再一次得到关注，新的业务、技术和设备不断涌现，有线电视网发展面临着新的机遇，如何构建面向综合业务的有线电视网将是实现重大突破的基础与方向。从综合业务需求、网络演进、双向接入技术发展以及网络架构设计的角度出发，全面分析了有线电视网的发展趋势，提出了基于有线电视网现状的发展演进的网络架构，这对有线电视运营商的业务发展和网络长远规划具有很强的实践指导意义。     

基于专家系统的数字化电视的智能故障检修

电视机器件的高度集成化和数字化进程加速了电视机的维修难度。为了提高维修效率，本文提出了一种基于专家系统的数字化电视智能故障检修设计方案。该方案要求电视机设计时，在控制系统中，利用I^2C总线可双向传递信号的特性，对单元电路的状态进行检测，根据反馈信号与专家库基准信号进行比较，根据存储的检修顺序进行推断，实现快速判断故障的部位，从而提高电视机维修的效率。     

企业馆藏信息资源数字化建设初探

数字图书馆因其传递信息的便利性和快捷性而成为未来图书馆发展的主要模式。企业图书馆数字化建设的关键是馆藏信息资源的数字化。在数字化资源建设中对馆藏数字化对象、输入设备、数据存储模式等的选择应根据各自的馆藏、人力、财力等资源具体分析，作切合实际的选择。     

户外广告媒体的持续数字化

户外数字化标识广告技术的应用势头似乎是无法抵抗的,但这项技术广泛普及的速度却很缓慢。再加上技术、后勤和法律上的一系列困难需要克服,另外还有金融问题减缓户外媒体的数字化标识在商业上的突破。在此,我们将从一个户外媒体公司的角度评价这项技术可能实现的方法。     

《华尔街日报》信息聚合服务成功实践分析

“RSS聚合新闻服务”的出现．使得网络传播进入了一个新局面．新闻网站在面临严峻挑战的同时也迎来了再发展的良好契机。本文将从实行信息产品的聚合策略的原因，互联网和数字化对信息产品的聚合有何影响，美国《华尔街日报》RSS聚合新闻服务的启示等几方面综合分析，针对我国新闻网站现状提出利用RSS技术推动其自身发展的借鉴方案．并对聚合新闻服务能否在我国成功复制进行理性的分析。     

A Prototype Bandpass Sigma-Delta Modulator Employing Crystal Resonator

This paper describes an initial work on a second-order bandpass Sigma-delta modulator employing crystal resonator. The aim of this work is to explore the possibilities of realizing bandpass sigma-delta modulator using non-electronic resonators, such as micro-mechanical resonators. The initial study is based on crystal resonators as they have similar characteristics as the other types of resonator and are readily available. In order to obtain the desired loop transfer function, a compensation circuit is proposed to cancel the anti-resonance in the crystal resonator. The modulator chip is fabricated in a 0.6-μ m CMOS process. The bandpass noise shaping is demonstrated in the experiment with a 1- and 8-MHz crystal resonator, respectively. Yong Ping Xu graduated from Nanjing University, P.R. China in 1977. He received his Ph.D. from University of New South Wales (UNSW) Australia, in 1994. From 1978 to 1987, he was with Qingdao Semiconductor Research Institute, P.R.China, initially as an IC design engineer, and later the deputy R&D manager and the Director. From 1993 to 1995, he worked on an industry collaboration project with GEC Marconi, Sydney, Australia, at the same university, involved in design of sigma-delta ADCs. He was a lecturer at University of South Australia, Adelaide, Australia from 1996 to 1998. He has been with the Department of Electrical and Computer Engineering, National University of Singapore since June 1998 and is now an Associate Professor. His general research interests are in the areas of mixed-signal and RF integrated circuits, and integrated MEMS and sensing systems. He is a Senior Member of IEEE. Xiaofeng Wang was born in Shangqiu, China, in 1980. He received B.Eng. degree from Northwestern Polytechnical University, Xi'an, China, in 2000 and M. Eng. degree from National University of Singapore, Singapore, in 2003, both in electrical engineering. He is currently working toward the Ph.D. degree at Tufts University, Medford, USA. His research is on high speed ADC design. Wai Hoong Sun was born in Taiping, Malaysia in 1976. He received the B. App. Sc. (Honours) degree in electrical engineering from the University of Toronto, Canada in 1999. After graduating, he joined Sharp Electronics Singapore as an R&D Engineer where he was involved in FPGA and digital IC design of display related circuits. In 2001 and 2002, he did full time research in the National University of Singapore on bandpass sigma-delta modulators. During that period, he was also a Graduate Tutor in electronics for second year electrical and computer engineering students. He then joined Philips Electronics Singapore in 2002 as a Lead Engineer. He did board-level designs for LCD and plasma televisions. He was also development project leader for a project that was successful in bringing to the market a range of LCD and plasma televisions. Currently, he is a Hardware Architect where he is responsible for the system-level electrical design of the television board.     

探索农村有线数字电视营销模式

有线电视数字化是当今世界广播电视发展的重大技术革命,是经济社会信息化的重要标志,更是国家加快宽带通信网、数字电视网和下一代互联网等信息基础设施建设,推进三网融合的需要。当前全国各地农村正在有序推进有线数字电视双向网改造和整体平移,大量资本的投入,如何产出最大的经济效益,这是对我们这代广电人的一大考验。结合当前安吉县报福镇部分农村有线数字电视双向网改造和整体平移的实际情况,阐述农村营销新模式,推动农村有线数字电视经济效益最大化。     

地市模拟微波网数字化改造方案

主要对大同地区市县原8G模拟微波网的数字化改造提出了切合实际的解决方案。改造后,一个模拟通道可以传输6~8套电视节目。这样,既节省频率资源的占用率,又可以提高传输质量。     

模拟中频信号数字化光传输系统设计

概述了模拟信号数字化转换技术的现状和中频信号数字化技术的重要性,主要介绍了中频信号数字化传输系统的实现原理、关键芯片和典型应用电路,并提供了对电路主要环节链路噪声的优化控制方法,可以给初始参与模拟中频数字化设计的人员提供一定的技术参考。