对等网络技术在IPTV中的应用研究

本文为解决IPTV网络中数据服务器传输瓶颈问题，提出了一种新方法，即引入对等网络技术。文中介绍了对等网络技术原理，将对等网络技术与组播技术进行了比较，研究了对等网络在fPTV应用中的实现方法，总结出对等网络技术的优势，并提出对等网络存在的不足，以及采用DRM技术来弥补不足的方法。     

大洋参震CCBN2012展示全系列额品

3月21日，CCBN2012在北京开幕，大洋展出了新媒体、云计算、3D以及高清制播等领域的创新成果。21日上午，国家厂电总局张丕民副局长一行在大洋公司邓伟副总裁的陪同下参观了大洋云媒资与新媒体工厂等展区，询问了解了云媒资等产品的功能和应用场景，对大洋在新媒体、云计算等方面开展的前沿性探索给予了肯定。     

谈谈如何搞好邮电企业筹资管理

就湖北省邮电企业如何适应两个根本转变，搞好筹资管理这一课题，从筹资方式，资金的运用及管理等方面进行了阐述，提出了合理负债，加大资金集中力度，联合建设等对策     

5G无人机安全研究综述

5G和无人机技术的融合，丰富了传统无人机的应用服务场景，然而5G无人机仍存在安全隐患。为此，针对5G无人机网络安全问题，调研了加密通信、信任管理等典型安全防护手段，同时针对无人机设备端存在的GPS欺骗等攻击，归纳了物理特性分析、物理隔绝等解决方案。在此基础上，对5G无人机发展前景进行了展望。     

古朴而优雅，来自维也纳的音韵——赏析维也纳（Viena acoustics）之巴赫（BACH）音箱

维也纳，一直以来都是公认的音乐圣地，西方古典音乐的发源地，一直是音乐艺术家灵感的源泉，莫扎特，贝多芬，斯特劳斯等等，音乐大师层出不穷。浓厚的音乐艺术背景，不仅吸引了一代又一代的音乐大师，也深深吸引了我们这些异国他乡的音乐爱好者。     

FLASH与数据库交互及发布技术研究

本文介绍了FLASH如何利用loadVariables方法、XML包等手段与SQLSERVER等数据库进行交互操作的应用技术，总结了FLASH应用程序作品在不同网络环境下的分发技巧，对FLASH如何显示动态数据等进行了研究，同时对几种实现思路进行了对比。     

云计算环境下的大型机场数据中心基础设施规划研究

当前，在大型机场的数据中心信息化项目建设中，云计算平台作为信息化底座，得到了普遍应用，但数据中心中的机房、布线等基础设施，通常仍按照常规的松散方案进行设计和建设，影响了上层业务的整体运行和维护情况。文中基于对青岛新机场、天府新机场等大型机场云数据中心的建设经验，从云数据中心整体建设的角度，对数据中心机柜规划、综合布线路由等基础设施建设逻辑提出了一种优化建设方案。     

瑞利信标非等晕性误差测量试验研究

人造信标为自适应光学大气湍流校正提供信标光源，在天文望远镜、激光传输领域可发挥重要作用，但也存在着一些无法克服的局限性，非等晕性误差就是其一。世界各国对非等晕性误差开展了大量的理论研究工作，但鲜有实际测量试验的公开报道。提出了非等晕性误差的测量方法，详细介绍了自主研发的人造信标非等晕性误差测量系统，采用两路高灵敏度EMCCD构成哈特曼波前传感器同时测量瑞利信标回光波前与自然星回光波前，分别开展了8耀18km高度瑞利信标聚焦非等晕性误差测量试验、12km 信标高度0~100rad偏角瑞利信标非等晕性误差测量试验，并获取了较为准确的测试结果。     

锐取“带外硬双流”解决方案在气象行业中的应用

一、应用背景 近年来，视频会议系统在国内气象行业的应用已逐步普及，给气象会商等日常工作的沟通带来了质的飞越，提高了工作效率，降低了沟通成本，气象会商等工作也越来越依赖于视频会议系统。     

3G全球发力数据业务成运营业增长引擎

日前，受美国次级债及全球通货膨胀等因素的影响，包括终端制造商、系统设备提供商等在内的电信企业业绩都被一层阴霾笼罩。但值得欣喜的是，3G数据业务的强劲表现，使得部署3G网络的运营商取得了持续的业务增长，也有效地弥补了固网等业务的下滑势头。     

From the editors: collaborative computing community - leveraging single-user applications for multiuser distributed collaboration

Single-user interactive computer applications are pervasive in our work and daily lives. Commonly used single-user interactive applications include text editors such as Notepad and Emacs, word processors such as Office Word and OpenOffice Writer, spreadsheet tools such as Office Excel and OpenOffice Calculator, slide authoring and presentation tools such as Office PowerPoint and OpenOffice Impress, Web authoring tools such as FrontPage and Dreamweaver, CAD systems such as AutoCAD and Catia, and media creation tools such as Maya and 3D Studio Max. The choices for real-time collaborative applications, however, are limited. Most advanced real-time collaborative applications are research prototypes with limited functionalities and usability. The vast majority of existing commercial applications were designed for single users, and future applications' design is expected to continue to be single-user-centric.     

Emerging technology for transient and broad-band analysis and synthesis of antennas and scatterers

Due to some applied problems of recent interest significant effort has been devoted to developing the technology of the transient and broad-band electromagnetic response of various objects such as antennas and scatterers as well as the production mechanisms for such transient fields. This paper addresses the various types of approaches which have been used for understandiag such transient/broad-band properties. While initially various approaches aid in analysis of such fields, in some cases other properties of the approaches lead to more powerful results such as synthesis of transient/broad-band properties.     

器具开关操作引发的安全问题

对于符合 IEC 61058的器具开关,IEC 60335等大部分整机产品安全标准中只对开关的电气参数、IP 等级、动作循环周期、断开类型等提出要求,对器具开关的操作性能,例如力度、形状、位置等没有提出具体要求。实际中,如果操作器具开关需要的力度过大,会引发安全问题,例如稳定性问题以及由此引发的其它问题。提出应当制定器具开关操作力度的要求,同时还应当对器具开关的安装位置与电热元件等功能性危险源之间的距离做出规定,从而避免对器具开关的操作成为安全隐患,同时建议对此作进一步的研究。     

超高速光通信的新技术及应用

介绍了相位调制、正交幅度调制、多电平调制等新型调制技术,偏振复用和正交频分复用2种新型复用技术,以及相干接收技术的原理、优点和应用,光子集成技术的应用和技术发展;最后介绍了这些新技术在400G／1T等超高速光通信中的应用。     

Performance control in wireless sensor networks: the ginseng project - [Global communications news letter]

Research on wireless sensor networks (WSNs) has mainly been focused on protocols and architectures for applications in which network performance assurances are not considered essential, such as agriculture and environmental monitoring. However, for many important areas, such as plant automation and health monitoring, performance assurances are crucial, especially for metrics such as delay and reliability.     

Development of a Predictive Controller for Use on a Direct Converter for High-Energy Physics Applications

Recently, considerable interest has been shown in direct (matrix) converter topologies as an alternative to conventional motor drives. In general, when compared with existing three-phase motor drives (rectifier–inverter types), these topologies offer advantages, such as reduced space and weight (due largely to the removal of the large electrolytic capacitor), four-quadrant operation, and high-quality current waveforms. Consequently, there is now considerable interest regarding direct converters in areas such as aerospace, where issues such as the size and weight of the converter are important. The work presented in this paper capitalizes on these advantages in power conversion for high-power radio-frequency supplies, such as those used in high-energy physics research and associated applications.      

制导雷达检测性能影响因素分析研究

制导雷达准确检测目标是实现其对目标识别和跟踪的前提。影响制导雷达检测性能的因素很多,主要包括与雷达相关的因素(如频率稳定性、雷达平台稳定性、雷达平台运动特性等)、与目标相关的因素(如目标结构、目标运动特性、RCS大小、RCS起伏等)、与环境相关的因素(如杂波特性、传输特性等)。针对制导雷达检测性能评估这一目的,将影响因素分为内部、外部和中间三个层面,主要从目标特性、杂波特性和制导雷达平台运动特性三个方面分析研究了制导雷达目标检测性能的影响因素。首先从信号角度推导了制导雷达目标检测的流程,然后详细分析了影响制导雷达目标检测性能的各项因素,得出了在通常制导雷达系统参数条件下,径向加速度的影响可以忽略;RCS无起伏、散射中心分布越稠密、散射中心分布越均匀目标的检测性能更优;杂波反射越强、幅度起伏越大、相关性越强对检测性能影响越大的结论,并通过仿真实验验证了结论的正确性。      

A survey of routing attacks in mobile ad hoc networks

Recently, mobile ad hoc networks became a hot research topic among researchers due to their flexibility and independence of network infrastructures, such as base stations. Due to unique characteristics, such as dynamic network topology, limited bandwidth, and limited battery power, routing in a MANET is a particularly challenging task compared to a conventional network. Early work in MANET research has mainly focused on developing an efficient routing mechanism in such a highly dynamic and resource-constrained network. At present, several efficient routing protocols have been proposed for MANET. Most of these protocols assume a trusted and cooperative environment. However, in the presence of malicious nodes, the networks are vulnerable to various kinds of attacks. In MANET, routing attacks are particularly serious. In this article, we investigate the state-of-the-art of security issues in MANET. In particular, we examine routing attacks, such as link spoofing and colluding misrelay attacks, as well as countermeasures against such attacks in existing MANET protocols.     

Retrospective correction of intensity inhomogeneities in MRI

Medical imaging data sets are often corrupted by multiplicative inhomogeneities, often referred to as nonuniformities or intensity variations, that hamper the use of quantitative analyses. The authors describe an automatic technique that not only improves the worst situations, such as those encountered with magnetic resonance imaging (MRI) surface coils, but also corrects typical inhomogeneities encountered in routine volume data sets, such as MRI head scans, without generating additional artifact. Because the technique uses only the patient data set, the technique can be applied retrospectively to all data sets, and corrects both patient independent effects, such as rf coil design, and patient dependent effects, such as attenuation of overlying tissue experienced both in high field MRI and X-ray computed tomography (CT). The authors show results for several MRI imaging situations including thorax, head, and breast. Following such corrections, region of interest analyses, volume histograms, and thresholding techniques are more meaningful. The value of such correction algorithms may increase dramatically with increased use of high field strength magnets and associated patient-dependent rf attenuation in overlying tissues.     

光纤通信系统中的可调谐色散补偿技术

对于高比特率的光纤通信系统,由温度或功率变化导致的色散波动高于系统的色散容限。因此,色散补偿单元必须具备动态可调谐功能才能适应下一代光通信网络发展的需要。本文介绍了几种动态可调谐补偿技术的基本原理性能特点及其国内外研究情况,其中包括啁啾光纤光栅法、虚像相位阵列法、G-T干涉仪法、阵列光纤光栅法和平面光波导法,并且简要讨论了可调谐色散补偿技术今后的发展方向。