RADIUS协议及其在IP电话中的应用

本文论述了分布式安全协议RADIUS的基本原理,通过分析指出了其优点与缺陷,并介绍了如何在IP电话系统中使用RADIUS协议。     

Passive Matrix Organic Electroluminescent Display for 3G Cellular Phone

The major features of the display technologies for 3G cellular phone are reviewed.The comparison between their potential candidates for 3G cellular phone is given ,and a detailed discussion is made on passive matrix organic electroluminescent display technology.A novel method to improve display contrast ratio is presented.Finally several 3G phone set prototypes with OLED display panels are given as well as the market forecast.     

联通公司机卡分离的构想与实现

文章介绍了中国联合通信公司推行CDMA机卡分离工作的定位及进展情况,并着重描述了机卡分离的技术规范。     

基于B/S结构的Windows95远程实时数据访问

根据工业环境的特点,对远程实时数据访问的方案进行了分析.结合当前技术条件,介绍了如何在纯Windows95环境下不编程通过调制解调器和公共电话网实现浏览/服务模式的远程数据访问.     

IP电话系统语音终端的设计及实现

以开发ＩＰ电话系统为背景,论述了语音终端及其具有实现方法,包括了对语音的实时采样、播放、自适应压缩和解压、在网络的实时传输等关键技术。同时对ＲＡＤｖｉｓｉｏｎＨ．３２３Ｓｔａｃｋ进行了一定的技术讨论,并对该系统今后的升级提出建议。     

大数据背景下基于手机信令的道路识别研究

研究主题是如何利用手机用户产生的切换信令数据进行道路匹配,完成道路用户识别。其基本原理是创新性地采用协同过滤的算法将手机用户的切换信令与通过路测产生的“最大权重路径”实现道路匹配。选取保定城市主干道为实验路网进行验证,对用户信令信息处理和道路匹配进行分析,证明了基于手机信令的道路识别的可行性,该成果将会为交通人流量的统计分析提供数据支撑。     

OLED显示技术进展

2007年以有机发光二极管(OLED)为主屏的便携式手机将进入量产阶段。以此为突破口,便携式多媒体游戏机等也已列入采用OLED显示屏的考虑范围之内。但与薄膜晶体管有源驱动液晶(TFT AM-LCD)相抗衡,OLED有待进一步改进。本文从成本、功耗、寿命以及柔性化等方面对现行的OLED技术发展方向做了简要的阐述,并对其作了进一步的展望。     

基于跟踪微分器的波门跟踪算法的研究

针对目标自动跟踪系统对目标跟踪算法实时性和精确性要求高的特点,提出了一种基于跟踪微分滤波器的运动目标跟踪方法.该算法利用跟踪微分器预测目标中心在下一帧体现在图像中可能出现的位置,以该位置为波门目标检测的中心,减少了目标的搜索范围,缩短了算法的运算时间.仿真结果表明,该方法具有不依赖于目标运动模型,实时性好,精确性高等优...     

‘Pirate’ radio,convergence and reception in Zimbabwe

Using a qualitative research approach, this study examines the appropriation of digital technologies and their implications for the reception of the so-called ‘pirate’ radio in Zimbabwe. It specifically explores how the use of the Internet (and its associated digital technologies), including the mobile phone by two prominent ‘underground’ radio stations, Short Wave (SW) Radio Africa and Voice of America’s Studio 7, beaming into Zimbabwe from the UK and the US, respectively, has impacted on the reception of their content. Drawing on reception theory, the paper highlights the ambiguities and complexities associated with the reception of (pirate) radio in the era of convergence in Africa. It argues that while both SW Radio Africa and Studio 7’s multiple digital transmission strategies have broadened the range of options available for the reception of their content (albeit in disproportionate ways), traditional forms of reception remain in force. This is largely because of enduring questions of access to digital technologies (especially the Internet), and the lasting connections between traditional live radio and the oral traditions of local culture. These contextual factors sustain reception practices that differ markedly from the scenario in the economically developed world of the North where digital technologies have radically redefined radio reception practices. Similarly, the mobile phone has expanded options for the generation and reception of news content from the radio stations thus pointing to the fact that in Africa convergence can indeed assume unique forms, shaped by an intricate combination of local socio-economic and cultural factors.     

纳米VO2薄膜的制备及其可见光透过率的改善

阐述了一种纳米VO2薄膜材料新型结构的制备方法.先用反应离子束溅射和退火工艺在玻璃基底上制备出具有相变特性的薄膜.HRTEM及XRD显示这种薄膜含有纳米量级的VO2颗粒,四探针测试电阻温度关系表明该类材料相变温度已经靠近室温,变化温度下测得的红外透过曲线表明该材料在相变前后具有良好的红外光开关特性.再针对该薄膜材料较低的可见光透过率,提出S iO2减反膜设计,取得了较好的实验效果.为开展VO2薄膜材料在智能窗类光电产品的应用研究打下了基础.