IPTV质量监测的研究与实现

电信运营商由于缺乏有效的IPTV故障定位手段,导致难以及时发现IP网络中潜在的拥塞、阻断、冲突等故障,难以实现对IPTV业务的＂实时监测、主动运维＂。本文将分析电信运营商对IPTV服务质量监测的需求,在此基础上结合本人对现有监控技术的研究提出一套IPTV服务质量监测系统的解决方案。     

IPTV要傍着宽带兴

2005年元旦期间,山东威海信息港宽带应用平台用户张先生对IPTV有了切身感受,视频点播的大片让他直呼过瘾。IPTV是利用IP宽带网络,集互联网、多媒体、通信等多种技术于一体,向用户提供直播电视、视频点播、上网浏览等多种交互式服务的业务。用户可以通过“IP机顶盒 电视”或电脑两种方式使用IPTV业务。     

一种宽带流媒体软件终端的设计和实现

提出了一种运行在IP宽带网、基于DirectShow技术、支持IPTV直播业务和VOD点播业务、在PC平台下的宽带流媒体软件终端。着重于整个软件终端系统的构架、各功能模块的功能设计、以及MPEG-2解码中的关键技术。     

电信运营商IPTV业务市场分析及运营策略

随着全球范围内电信基础建设和网络技术的飞速发展，带宽成本迅速下降，基于IP视频传输的市场需求已经被激活，越来越多的用户不满足于IP网上传输信息和数据，他们更希望在网上传输以音视频为代表的更加丰富的多媒体内容。在这一需求的推动下，网络电视（IPTV）市场迅速发展起来。IPTV在世界范围内受到电信运营商的重视。电信运营商通过IP宽带网络提供的IPTV业务也在迅速发展。     

光网用户终端远程诊断方案研究及现网实施

随着上海电信光网宽带产品的大规模普及,家庭业务更加丰富,除了可以使用20 Mbit/s以上宽带上网业务外,还可以使用视频应用(如IPTV)以及基于IP的话音(如VoIP)服务。上述综合复杂的业务对用户侧故障定位及排查提出了挑战,也给上海电信售后、维修服务带来了更大阻力。本文着重研究和实现基于终端管理协议TR-069的ITMS(综合终端管理系统)在光网用户侧终端故障诊断方面的商用方案,并将数据挖掘方法应用于诊断数据继而得出实用结果。为光网用户侧终端的故障诊断发展做了有益的探索和尝试,并做了前瞻性的展望。     

IPTV直播容灾技术方案研究

自三网融合开展以来,IPTV业务已从宽带增值业务逐渐发展为电信基础业务,其中直播业务占70%左右。运营商对直播业务保障尤为重要。基于此,简要说明了采用主备方式部署直播转码服务器,在同一PIM-SM域的主备区域配置相同组播源IP地址,提供相同组播地址的直播频道。用户接入组播时,根据最优组播路径选择,从而实现IPTV直播容灾功能。     

基于IPTV业务的承载网络技术

IPTV业务具有数据传输量大、对网络时延及其抖动敏感等特点,因此,IPTV的核心在于构建一个基于IP技术的多业务承载的系统。多播技术、CDN(Content Delivery Network)、P2P技术够成了主要的基于IPTV业务的承载网络技术。     

宽带IP网发展的实践与思考

IP化已不再是一个趋势,而是不争的事实。电信级以太网技术的出现,加速了IP网与传输网的融合。如何能够有效地融合,共同向下一代承载网演进已是急需解决的课题。基于此,本文简要回顾了上海公司宽带IP网络发展历程,围绕近年重点工作介绍了IP综合业务承载网的规划与建设和IP全业务支撑系统的构建与应用等相关系统情况,重点说明了IPTV、软交换等业务承载的实现方式和主要特点,最后结合工作体会提出了几点思考。     

IP业务流量及带宽需求预测计算方法在工程实践中的应用

基于IP网络承载数据、语音、视频、无线等多种业务已成为网络发展的趋势。NGN语音、IPTV、三网融合等业务的开展,对承载网络的带宽、质量、可靠性提出了更高的需求,本文例举了在工程实践中某城市IP业务流量及带宽需求预测的计算方法的应用详解。     

一种可支持多种多媒体业务的基于IMS的IPTV架构

IP多媒体子系统用于实现端到端的IP多媒体通信,具有接入无关性、对各种接入技术广适性的特点,因此,下一代网络采用IP多媒体子系统作为核心架构.提出一个基于IP多媒体子系统的IP电视架构,在IP多媒体子系统核心模块的基础上,以一组互相独立的基于会话初始化协议的功能模块构成应用服务器,并设计了能够支持和提供不同IM S业务的客户端与内容提供商端,使该IPTV框架可以在下一代网络上支持基于IP多媒体子系统的包括IPTV业务在内的多种多媒体业务.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.