WeCom——企业IP融合通信解决方案

语音、数据、视频是人类重要且高效的通信方式，但长期以来，这几种通信方式相互独立，既影响沟通效果，也给企业带来了较高的通信成本。企业IP网络的完善及IP集合通信技术的成熟，使得在统一IP网络上实现语音、数据、视频融合成为可能，也成为不可逆转的趋势。IP网络最初只能实现简单的网络连接、E—mail、文件传送、信息发布等业务。1998年以后，随着网络控制技术和QoS技术的发展，IP网络逐渐成为一个多业务的承载网络，Voice over IP、Video over IP等基于IP的综合应用开始出现，各种通信手段的传输通道统一到了IP网络上。目前，随着新型IP技术的兴起，语音、数据、视频三种通信手段进一步融合，以IP集合通信的形态服务于广大行业和企业用户。     

Avaya推出企业IP语音通信网络实时管理方案

全球领先的企业通信软件、系统和服务供应商Avaya公司目前在业界率先推出面向IP语音通信的远程管理服务，使企业在不间断语音通信的情下对其IP语音通信网络进行监控和管理。通过这项服务，企业能够使问题在影响到网络运作之前便被及时发现．并在大多数情况下自动的解决这些问题。     

基于NS的自适应多速率网络语音通信的性能分析

目前,几乎所有的语音电话系统（VoIP）都采用固定速率传输,这使得网络丢包,特别是连续丢包无法避免,因此导致了严重的语音质量下降.针对这一问题,给出了一种新的抗分组丢失的网络语音通信系统,并用网络仿真软件NS（network simulator）对该系统进行了性能分析,仿真实验证明,所提出的网络语音通信系统在网络丢包、平均延迟和主观听觉方面明显优于传统的IP语音电话系统.     

阿尔卡特 亚太企业网络技术开发立足中国

10月18日，2005年（第15届）中国国际通信设备技术展览会在北京开幕，这是今年在中国和亚洲举办的规模最大的国际信息通信展览会。而同在这天，阿尔卡特公司在上海成立亚太地区企业网络技术开发中心。开发中心设在上海浦东金桥开发区，负责阿尔卡特企业网络方集的全面本地化开发并服务亚太地区市场。研发项目包括企业语音通信平台、商务电话和手机、IP网络和通信应用，其它重点领域还包括VoIP和企业移动解决方案的开发和认证。     

IP融合通信， 电力企业新选择

随着广大电力企业IP数据网络的完善及IP集合通信技术的成熟，在统一的IP网络上实现语音、视频、数据已经成为不可逆转的趋势。随着下一代企业网（NGeN）的兴起，语音、视频和数据三种通信手段进一步融合，以IP集合通信的形态开始服务于广大电力用户。本文试图分析电力网络目前的现状，对未来电力企业网络发展趋势进行深层次探讨。     

Avaya与Juniper提供智能通信方案

Avaya公司与Juniper网络公司近日宣布．联手提供基于标准的安全可靠的智能通信解决方寨并面向全球分布式布局的企业。这些解决方案利用Avaya在企业IP语音通信领域和Juniper在毋网络与安全领域的专长．可为企业提供安全．高质量的语音．数据和融合通信．以帮助他们保护敏感数据和维护网络的完整与性能．     

北电推出新的以太网交换机产品系列，发展统一通信

北电宣布推出新的以太网路由交换机系列，以帮助企业顺利完成迁移至IP语音通信（VoIP）和先进的统一通信应用。北电为企业提供了可靠的网络基础，使其更好地实现企业关键通信业务的融合。[第一段]     

提高网络视频会议质量的QoS技术

随着IP网络与Internet在当今使用得越来越广泛，基于IP网络的视频会议系统也越来越为广大的消费者所接受，在现有企业网内融合语音、视频和数据通信，能为公司缩减大笔商务开支，其中尤以VoIP和视频会议最为重要。但融合通信会引发网络性能问题，企业网不但要能提供多种服务，而且要保证端到端的良好性能，而召开网络视频会议最重要的就是要保证有良好的音视频质量。     

试论企业主干网络设备的选型

1概述大型企业主干网络工程的建设，需要首先研究用户的网络应用水平及各应用系统的发展状况，新一代网络应用系统大多建立在语音、视频等多媒体信息通信基础上，而不像传统应用大多以数据通信为主。在目前和可以预见的将来，各机构及其相互间传输和交换的信息主要是语音、数据和视频，包括语音信息、办公自动化信息、视频监控信息等。如何将这些信息以及不断出现的新型信息，如多媒体业务和电视会议等，有效地结合起来，在多业务点之间实现实时、可靠的传输和交换；如何将现有设备、网络、业务实施有效兼容和共享，避免重复建网、重复投资…     

Elastix在企业通信中的应用

随着VoIP技术的发展,企业内部语音通信的网路化成为一种趋势．本文从企业通信需求出发分析了企业语言通信的应用场合,基于软交换在网络语音通信上的应用,介绍了一种稳定,流行的交换开源项目——Elastix,并设计了一种应用于企业通信的Elastix系统架构,为企业提供一个完整的通信解决方案．     

On a wing and a prayer

Aircraft giants Boeing and Airbus are pinning their hopes on very different visions of how air travel will evolve in the coming decade.     

一年之间，物换星移

去年的这个时候,供货商们还在为生存而挣扎。如今,2009年的年报已经公布,许多供应商的年报业绩之好,就连最乐观的分析师也始料未及。这种变化的原因很简单：供应商们大幅削减成本,接下来是强劲的需求,这又导致了随后高企的设备利用率。     

Building a in a flash supercomputer

A flash mob is a group of strangers, organized over the Internet, that comes together briefly, acts out a predetermined scenario-often something as simple as clapping for 30 seconds-and then disperses. A supercomputer is a very fast and powerful computer that outperforms most mainframes, at a cost, typically, of millions of dollars. Can a flash mob build a supercomputer? It can sure try, and so it did on 3 April at the University of San Francisco's Koret athletic center. The goal was to run the Linpack benchmark, a standard method of assessing the speed of supercomputers, to achieve a speed of at least 403 gigaflops (billion floating point operations per second). This would be fast enough to earn the system a place on the list of the world's fastest 500 supercomputers. The goal was not reached. The group reached just 180 gigaflops before it was time to pack up the computers and go home. However, even though the San Francisco effort fell short of speed goal, it did ignite imaginations.     

Cooperative control of a human and a robot manipulator for positioning a cart on a frictionless plane

Robots may be expected to execute some tasks in cooperation with humans. Control systems for such robots should be appropriate to adapt to human characteristics in order to successfully accomplish the task. Pushing a cart on a frictionless plane in cooperation with a human is a basic example to such a task. To control the motion of an object from one point to another on a frictionless plane is impossible by only pushing in one direction without supporting it in the opposite direction, since as soon as the force is applied, the object will move without stopping its motion. In this paper, compliant cooperative positioning of a cart on a frictionless plane by a human and a manipulator is proposed using impedance control method with the parameters obtained from human–human cooperation.     

基于智能手机压电基片上微液滴位置分析章

为了降低微流分析成本,该文提出了基于智能手机检测压电基片上目标微液滴方法,并开发出相应的应用软件,通过分析微液滴颜色信息和几何信息定位目标微液滴位置,结合分析时间获取微液滴输运速度。为验证提出方法的正确性,以5 μL黑色墨水溶液微液滴为研究对象,进行压电基片上微液滴识别和位置分析实验。结果表明,该文所提方法和开发的应用软件可识别和定位压电基片上微液滴,在功率为27.5 dBm时,第2~10 s段内微液滴输运速度为0.416 mm/s。     

Analysis of a coaxial-to-waveguide adaptor including a discendedprobe and a tuning post

A field matching analysis of a coaxial-to-waveguide adaptor incorporating a disc-ended probe and a tuning post is presented. In this analysis, the tuning post is considered as a short-circuited second probe. A computer algorithm for calculating the input impedance of this structure is developed. This algorithm is used to investigate and improve the operation of a commercially available coaxial-to-waveguide adaptor     

Transmission-Line Properties of a Strip on a Dielectric Sheet on a Plane

The subject is a strip Iine formed of a strip and a parallel ground plane separated by a dielectric sheet (commonly termed "microstrip"). Building on the author's earlier papers all the significant properties are formulated in explicit form for practical applications. This may mean synthesis and/or analysis. Each formula is a close approximation for all shape ratios, obtained by a gradual transition between theoretical forms for the extremes of narrow and wide strips. The effect of thickness is formulated to a second-order approximation. Then the result is subjected to numerical differentiation for simple evaluation of the magnetic-loss power factor from the skin depth. The transition formulas are tested against derived formulas for overlapping narrow and wide ranges of shape. Some of these formulas are restated from the earlier derivations and others are derived herein. The latter include the second-order approximation for a narrow thin strip, and a close approximation for a narrow or wide square cross section in comparison with a circular cross section. Graphs are given for practical purposes, showing the wave resistance and magnetic loss for a wide range of shape and dielectric. For numerical reading, the formulas are suited for programming on a digital pocket calculator.     

The measurement of a large antenna using a spacecraft as a receiver

Two computational methods for obtaining the gain pattern of a large antenna using power levels recorded by a spacecraft are developed from the transmission equation. Nominally, the large antenna is linearly polarized while the spacecraft's receiving antennas are circularly polarized. Since the spacecraft has no attitude control system, the orientation of the receiving antennas is not known a priori nor its orientation the same from orbit to orbit. The first method relies on an independent spacecraft attitude determination system to furnish the orientation of the receiving antennas. It combines this information with receiving-antenna gain measurements to give the power level of the incident radiation. Losses due to polarization mismatch are taken into account, but polarization loss factors are not actually computed. The second method relates simultaneous measurements made by separate channels with separate receiving antennas. By solving a system of equations numerically, one can determine the direction of the incident radiation as well as its power level. This alleviates the need for an attitude determination system. These methods originated in the operations of the spacecraft NUSAT1 (northern Utah Satellite)