光子学及其发展

光子学是继电子学之后正在迅速发展的一个极其重要的前沿科学，本文对光子学的动态，定义，诞生时间，内容和范围，以及与光子学有关的理论，材料，器件和应用的发展状况，作了介绍和评述，光子学理论是以“光具有波粒二象性”为出发点，以经典电动力学和量子电动力学为理论基础，包括电磁光学，量子光学，激光理论，导波光学和光子光学等；光子学材料包括玻璃，半导体，非线性光学晶体，有机和聚合物等；光子器件着重介绍半导体激光     

全新的移动信息化发展模式——山东省移动信息化综合服务平台

基于无线通信技术的移动信息化具有广泛的渗透性和增值作用，其在经济和社会各领域的广泛应用，将极大地提高工作效率，降低能耗和生产成本，减少环境污染，有力地推动经济发展和社会进步。大力推广移动信息化应用，发挥其渗透和倍增作用，可以培育出众多新兴产业，促进传统产业结构调整和优化升级，有效提高国民经济运行质量。     

光纤接入网组结构优选及分步发展技术构思

本根据本地及国内外光纤接入网组网形式，结构及使用情况，分析和他们在应用中的优缺点，优选网络结构２和设备类型，提出分步发展的技术构思设计，力求做到“一次规划，分步实施，满足当前需求，兼顾中长期目标”，降低网络投入和运行成本，避免重复建设和浪费，保证网络升级和发展的持续性.     

光纤接入网组网结构分析及应用

根据要于及国内外光纤接入网组网形式，结构及使用情况，分析应用中的优缺点，优选网络结构和设备类型，提出分步发展的技术构思设计，力求做到，一次规划，分步实施，满足当前需求，兼顾中长期目标，降低网络投入和运行成本，避免重复拆建和浪费，保证网络升级和发展的持续性。     

国家经贸委提出要大力推进技术创新工程

最近，国家经贸委在确定今年技术创新工作重点时指出，要大力推动技术创新工程的实施，以技术创新试点企业和试点城市为突破口，推进企业的技术创新体系和运行机制的建设，切实将技术创新作为结构调整的制高点，优化存量，发展具有自主知识产权的产品的技术，提高企业的竞争力。国家经贸委提出，今年技术创新工作重点是积极开展政策和信息引导，加强宏观调控，建立和完善技术创新政策、法规，把技术创新工作纳入到整体上搞好国有经济的大环境中，完善全国技术创新项目和信息网络，建立和完善专家咨询系统。今天要围绕企业改革抓大放小，系统…     

低轨小型卫星的发展和应用

本文介绍低轨小卫星的发展和应用前景。低轨小卫星，体积和重量小，轨道低，功能单一，智能化，制造和发展都很容易，投资费用低，受到用户的普遍欢迎，有广阔的发展和应用前景。小卫星在近年发展迅速，应用广泛，已经受到世界各国的重视。在许多方面，已经应用小卫星和计划中应用小卫星的例子很多，本文只作简要介绍，目的在于引起人们的重视，发展我国的小卫星事业。     

浅谈多媒体通信

多媒体通信是一种新型的通信系统，它是指表示，存储，重现和传输多媒体信息，诸如文本，语音，图形，图像，音像和影像等。．本文介绍了多媒体通信的概念，特点，应用和业务。     

Internet防火墙及其发展趋势

本叙述了Internet来自外部，内部，硬件，软件方面的十种安全威胁和攻击，给出了防火墙的限制，隔离，筛选，过滤和屏蔽作用，介绍了防火墙的六种基本结构类型，论滤了过滤路由器，双宿主主机，主机过滤，过滤子网和吊带式五种安全结构，分析了传统防火墙的七种不足，给出了目前防火墙混合应用包过滤技术，代理服务技术和其他一些技术的发展趋势。     

微电机械系统/微光电机械系统的应用及前景

微技术正在解决除了微电子技术之外的微机械，微光学，微声学，微流体技术，微反应技术等领域的微型化和集成化问题，其进一步的重点将放在微米量级的相关器件和系统的研究上。近10年来，微技术已尼形成了各种产品和日用品的数十亿美元资产的市场，预计未若干年仍会高速增长，由于人们对医疗保健，信息，可移动性和可持续发展的渴望，刺激了对微技术产品的需求，一些高技术生产工艺和材料应运而生，而新器件和新系统的发展也使得一些用来模拟器模拟器件功能，生产工艺和综合优化过程中的软件显得到关重要。此外，微器件的应用正在扩展至信息，自动化和医学技术领域，同时也为未来由微小型化在化学工程，生命科学，工业自动化和光通信等学科引起的变革奠定了全新的基础。     

第三届微波及毫米波技术国际会议(ICMMT2002)在北京召开

由中国电子学会主办的第三届微波及毫米波技术国际会议（ICMMT2002）于2002年8月17～19日在北京召开，本次会议得到了国家自然科学基金委、IEEE MTT-S，IEEE EDS，IEEE APS，日本的IEICE和韩国的KITE的支持。 本次会议共收到论文320多篇，收录294篇（含特邀报告9篇），与会代表分别在2个全体大会和35个专题会议上宣读论文229篇，宣读率接近80%。本次会议内容涉及电磁理论与CAD技术，天线和智能天线，传播和导航，真空源和固态源，射频IC，SiGe器件和射频MEMS，封装和互联，电磁兼容和电磁干扰，微波和光相互作用及光学和…     

Quality-optimised MPEG2 video data rate control using fuzzy logictechniques

Fuzzy logic control has been employed to improve the rate control mechanism for a MPEG2 video encoder. The data rate of compressed video is controlled by video encoders for either variable bit rate (VBR) or constant bit rate (CBR) applications. In VBR video transmission, it is considered to be more efficient to regulate the video rate by the video coder than by network management in order to avoid network congestion and maintain stable video quality. This rationale can also be applied to CBR transmission. Two fuzzy-logic-based rate control techniques are proposed which maintain the buffer occupancy within a specified range. In the proposed technique for VBR applications, a video quality measure is taken as the crucial control parameter. In CBR rate control, the video data rate or the buffer occupancy is also considered as a fuzzy logic variable. Proposed techniques are designed to control either data rate or video quality, depending on the mode of transmission, i.e. CBR or VBR for the MPEG2 encoder. The performance is compared to a typical VBR MPEG video coder with fixed quantiser step sizes for VBR and also to the CBR video coder with MPEG2 TM5 at typical channel rates. Simulation results are presented with peak signal-to-noise ratio, data rate variation and buffer occupancy as the performance measures     

基于ARM及μC/OS-Ⅱ的RGB视频矩阵设计

RGB视频矩阵也叫RGB视频信号切换器。在多媒体视频会议、安防监控、广播电视等领域都起着非常重要的作用。随着某些场合用到切换信号源的不断增多与控制地点的灵活变化,对视频矩阵的控制方式灵活性要求也越来越强烈,一种控制方式远远不能满足人们的需求,因此多种控制方式并存,才能使RGB视频矩阵发挥更大作用空间。该设计用低成本ARM LM3S6911作为主控制芯片,配合MAX232串口收发芯片,网络变压器芯片HR601680,还有本机键盘模块和LCD模块,采用专业视频信号切换芯片ISL59530实现了RGB视频矩阵的按键、串行口、以太网口3种控制方式并存。在软件方面成功地将μC/OS-Π内核移植到微控制器LM3S6911上,保证了系统操作的实时性,并提高了切换速度     

基于半马尔科夫决策过程的视频传输拥塞控制算法

针对传输控制协议(TCP, transmission control protocol)的拥塞控制算法未能满足视频传输质量要求的问题,提出了一种基于半马尔科夫决策过程的视频传输拥塞控制算法。首先, 为克服目前基于峰值信噪比的视频质量评估方法实时性低的缺点,设计了一种可在线运行的无参考视频质量评估方法。其次,根据接收端视频质量的反馈,采用半马尔科夫决策过程对拥塞控制进行建模,并通过求解此模型得到拥塞控制参数的调整策略。仿真实验结果表明,与目前典型的拥塞控制算法相比,该算法不但具备更好的TCP友好性,而且有效地提高了解码后视频序列的主观和客观质量。     

基于H.323协议的IP视频通信控制策略

针对IP视频通信来实现端到端的业务控制，始终是研究的热点问题。本从视频传输机制和业务接入控制机制两个方面对IP视频通信控制机制进行了分析，最后，给出了在城域IP网内实现IP视频通信端到端的控制策略。     

Adaptation strategies for MGS scalable video streaming

An adaptive streaming framework consists of a video codec that can produce video encoded at a variety of rates, a transport protocol that supports an effective rate/congestion control mechanism, and an adaptation strategy in order to match the video source rate to the available network throughput. The main parameters of the adaptation strategy are encoder configuration, video extraction method, determination of video extraction rate, send rate control, retransmission of lost packets, decoder buffer status, and packetization method. This paper proposes optimal adaptation strategies, in terms of received video quality and used network resources, at the codec and network levels using a medium grain scalable (MGS) video codec and two transport protocols with built-in congestion control, TCP and DCCP. Key recommendations are presented to obtain the best results in adaptive video streaming using TCP or DCCP based on extensive experimental results over the Internet.     

基于ARM的水域移动视频监控平台控制系统的设计

该文介绍了一种基于ARM的水域移动视频监控平台控制系统的设计和实现方法。经测试,该监控系统工作稳定并已成功应用于相关视频监控领域。为了实现水域移动视频监控平台的移动性、方便性、可操作性,设计了基于水域移动视频监控平台的控制系统。首先分析了该视频监控平台控制系统的优点,并简单介绍了系统的总体设计及模块功能,然后重点介绍了基于ARM芯片为内核,采用嵌入式系统设计和实现方法,最后分析了测试效果。实现视频监控、平台控制等功能。该设计针对性强,功能实用,稳定性可靠。     

多卡视频点播服务器的实现

基于双向有线电视网的视频点播VOD(V ideo On Command)系统中视频服务器是其核心的部分。介绍一种基于D irectShow技术开发单个视频解压卡控制进程,进而通过多进程控制多个视频解压卡方式实现的视频服务器,并从网络构架的角度分析了视频播放服务器的分布式应用。     

On network bandwidth sharing for transporting rate‐adaptive packet video using feedback

While existing research shows that feedback‐based congestion control mechanisms are capable of providing better video quality and higher link utilization for rate‐adaptive packet video, there has been relatively little study on how to share network bandwidth among competing rate‐adaptive video connections, when feedback control is used in a fully distributed network. This paper addresses this issue by presenting a framework of network bandwidth sharing for transporting rate‐adaptive packet video using feedback. We show how a weight‐based bandwidth sharing policy can be used to allocate network bandwidth among competing video connections and design a feedback control algorithm using an Available Bit Rate (ABR)‐like flow control mechanism. A novel video source rate adaptation algorithm is also introduced to decouple a video source's actual transmission rate from the rate used for distributed protocol convergence. Our feedback control algorithm provides guaranteed convergence and smooth source rate adaptation to our weight‐based bandwidth sharing policy under any network configuration and any set of link distances. Finally, we show the on‐line minimum rate renegotiation and weight adjustment options in our feedback control algorithm, which offer further flexibility in network bandwidth sharing for video connections. Copyright © 2000 John Wiley & Sons, Ltd.     

Foveated video compression with optimal rate control

Previously, fovcated video compression algorithms have been proposed which, in certain applications, deliver high-quality video at reduced bit rates by seeking to match the nonuniform sampling of the human retina. We describe such a framework here where foveated video is created by a nonuniform filtering scheme that increases the compressibility of the video stream. We maximize a new foveal visual quality metric. the foveal signal-to-noise ratio (FSNR) to determine the best compression and rate control parameters for a given target bit rate. Specifically, we establish a new optimal rate control algorithm for maximizing the FSNR using a Lagrange multiplier method defined on a curvilinear coordinate system. For optimal rate control, we also develop a piecewise R-D (rate-distortion)/R-Q (rate-quantization) model. A fast algorithm for searching for an optimal Lagrange multiplier lambda* is subsequently presented. For the new models, we show how the reconstructed video quality is affected, where the FSNR is maximized, and demonstrate the coding performance for H.263,+,++/MPEG-4 video coding. For H.263/MPEG video coding, a suboptimal rate control algorithm is developed for fast, high-performance applications. In the simulations, we compare the reconstructed pictures obtained using optimal rate control methods for foveated and normal video. We show that foveated video coding using the suboptimal rate control algorithm delivers excellent performance under 64 kb/s.     

Video rate control using a radial basis function estimator for constant bit-rate MPEG coders

Compressed video is a source of bursty traffic in communication networks whose data rate needs to be controlled within the available channel capacity, particularly, when it is transmitted via a fixed rate channel. Since the video rate is nonstationary and bursty at large-scene variations in a statistical sense, we propose a feed-forward, estimator-based rate control scheme associated with spatio-temporal activity features (STAF) for MPEG video encoders. This information is used to estimate the video rate of input picture frames. The estimated video rate enables the future buffer occupancy to be calculated and permits the encoder to adapt the quantisation step size to limit the increase or decrease in video rate due to dramatic scene variation. The current and future occupancies are used in a nonlinear quantiser control scheme to determine an appropriate quantisation step size depending on them. The novelty of this technique is that the nonlinear prediction and the nonlinear quantiser control are combined to achieve effective feed-forward video rate control, particularly, for realistic video containing various scene variations. In this paper, we highlight the innovative structure of the scheme and evaluate the performance of rate control algorithms with heuristic, linear and nonlinear rate estimators in the framework of the MPEG2 test model 5 video encoder. The performance measures are the occupancy of a two-frame delay buffer and peak signal-to-noise ratio (PSNR) for video quality.