互联网电视

据国外报道，日本佳能公司计划斥资7．3亿欧元（约合11亿美元），收购荷兰复印机和打印机生产商奥西（Oce）。     

基于流行度预测的互联网+电视节目缓存调度算法

针对互联网+电视平台为提高热点节目命中率而过渡消耗存储空间的问题,提出一种基于流行度预测的节目缓存调度算法PPRA(popularity prediction replication algorithm).首先,在对实际测量数据进行统计与分析的基础上,使用随机森林(random forests, RF)算法构建节目流行度预测模型.同时,针对所选特征存在的“维数灾难”问题,利用主成分分析法(principal component analysis, PCA)实施特征降维处理,以实现视频流行度预测值的快速计算.然后基于节目流行度预测数据调度缓存中的节目.最后以某广电运营商130万用户120 d的收视数据为例,对PPRA算法进行实验.实验结果表明,在保证一定缓存命中率前提下,与LRU,LFU算法相比,PPRA算法仅需30%的存储空间,可有效降低互联网+电视平台的建设成本.     

基于电力线网络的电视机以及组网方法探讨

旨在探讨一种电视机宽带接入技术,更具体地说,涉及一种利用电力线以及xDSL（Digital Subscriber Line,数字用户线）实现电视机宽带接入的调制解调装置和组网方法。该方法实现了网页浏览、视频会议、与个人电脑实现数据共享、电视机之间联机游戏、高清多媒体影音下载和播放等娱乐、商务功能。     

Toward high-quality gradient estimation on regular lattices

In this paper, we present two methods for accurate gradient estimation from scalar field data sampled on regular lattices. The first method is based on the multidimensional Taylor series expansion of the convolution sum and allows us to specify design criteria such as compactness and approximation power. The second method is based on a Hilbert space framework and provides a minimum error solution in the form of an orthogonal projection operating between two approximation spaces. Both methods lead to discrete filters, which can be combined with continuous reconstruction kernels to yield highly accurate estimators as compared to the current state of the art. We demonstrate the advantages of our methods in the context of volume rendering of data sampled on Cartesian and Body-Centered Cubic lattices. Our results show significant qualitative and quantitative improvements for both synthetic and real data, while incurring a moderate preprocessing and storage overhead.     

A differentiated services architecture for multimedia streaming in next generation Internet

This paper presents a Differentiated Services (Diffserv or DS) architecture for multimedia streaming applications. Specifically, we define two types of services in the context of Assured Forwarding (AF) per hop behavior (PHB) that are differentiated in terms of reliability of packet delivery: the High Reliable (HR) service and the Less Assured (LA) service. We propose a novel node mechanism called Selective Pushout with Random Early Detection (SPRED) that is capable of simultaneously achieving the following four objectives: (1) a core router does not maintain any state information for each flow (i.e., core-stateless); (2) the packet sequence within each flow is not re-ordered at a node; (3) packets from HR service are delivered more reliably than packets from LA service at a node during congestion; and (4) packets from TCP traffic are dropped randomly to avoid global synchronization during congestion. We show that SPRED is a generalized buffer management algorithm of both tail-dropping and Random Early Detection (RED), and combines the best features of pushout (PO), RED and RED with In/Out (RIO) mechanisms. Simulation results demonstrate that under the same link speed and network topology, network nodes employing our Diffserv architecture have substantial performance improvement over the current Best Effort (BE) Internet architecture for multimedia streaming applications.     

A novel resource scheduling algorithm for QoS-aware services on the Internet

The popularity and availability of Internet connection has opened up the opportunity for network-centric collaborative work that was impossible a few years ago. Contending traffic flows in this collaborative scenario share different kinds of resources such as network links, buffers, and router CPU. The goal should hence be overall fairness in the allocation of multiple resources rather than a specific resource. In this paper, firstly, we present a novel QoS-aware resource scheduling algorithm called Weighted Composite Bandwidth and CPU Scheduler (WCBCS), which jointly allocates the fair share of the link bandwidth as well as processing resource to all competing flows. WCBCS also uses a simple and adaptive online prediction scheme for reliably estimating the processing times of the incoming data packets. Secondly, we present some analytical results, extensive NS-2 simulation work, and experimental results from our implementation on Intel IXP2400 network processor. The simulation and implementation results show that our low complexity scheduling algorithm can efficiently maximise the CPU and bandwidth utilisation while maintaining guaranteed Quality of Service (QoS) for each individual flow.     

CPXe: web services for Internet imaging

The Common Picture eXchange environment leverages the Web services paradigm to serve the electronic photographic services market, combining open standards for exchanging digital images, orders, and other information with an online directory of service providers.     

Internet resource discovery services

An overview of resource discovery services currently available on the Internet is presented. The authors concentrate on the following discovery tools: the Wide Area Information Servers (WAIS) project, Archie, Prospero, Gopher. The World-Wide Web (WWW), Netfind, the X.500 directory, Indie, the Knowbot Information Service (KIS), Alex, Semantic File Systems, and Nomenclator. The authors summarize the surveyed tools by presenting a taxonomy of their characteristics and design decisions. They also describe where to find and how to access several of the surveyed discovery services. They conclude with a discussion of future directions in the area of resource discovery and retrieval     

Programming Internet telephony services

The Internet offers an opportunity to enhance traditional telephony services, such as call forwarding, through interaction with e-mail, the Web, and directory services, as well as traditional media types. How do you effectively program these services? The authors propose a CGI (common gateway interface) solution for trusted user/developers (such as administrators) and the Call Processing Language (CPL)-a simple, robust, safe, call processing language-for untrusted user/developers     

Integrating Internet telephony services

Cost savings and the ease of developing and adding new services have motivated great interest in Internet telephony, which integrates services provided by the Internet with the public switched telephone network (PSTN). Internet telephony relies on several protocols, including the real-time transport protocol (RTP) for multimedia data transport and the session initiation protocol (SIP) or H.323 for establishing and controlling sessions. SIP can integrate with other Internet services, such as email, the Web, voice mail, instant messaging, conference calling, and multimedia collaboration. We have implemented a SIP-based software suite called the Columbia Internet extensible multimedia architecture (Cinema), which we installed and integrated with the existing private branch exchange (PBX) infrastructure in the computer science department at Columbia University. The Cinema environment provides interoperability with the PSTN, programmable Internet telephony services, and IP-based voice mail. It also integrates Web access and e-mail for unified messaging and supports multiparty multimedia conferencing. The setup lets us extend our PBX capacity and will eventually let us replace it while keeping our existing phone numbers. It also provides an environment in which we can easily add new services and features, including interoperation with existing multimedia tools, e-mail access from standard. telephones, network appliance control, and instant messaging support     

Catch-up TV forecasting: enabling next-generation over-the-top multimedia TV services

Due to recent developments in Over-The-Top (OTT) technologies, Pay-TV operators have begun a migration process of managed IP Television (IPTV) services to more appealing OTT approaches. In these scenarios, being able to predict when and what resources will be necessary at any given point is crucial to a high-quality, efficient, and cost-effective operation, especially when dealing with the dynamic and resource-intensive requirements of IPTV multimedia services. To evaluate the advantages of demand forecasting for efficient Catch-up TV delivery on OTT scenarios, this research work explores several classes of machine learning models regarding their accuracy, computational requirement trade-offs, and deployability. The training process relies on a dataset comprised of Catch-up TV usage logs acquired from an IPTV operator’s live production service containing over 1 million subscribers. A predictive and dynamic resource provisioning approach is proposed and evaluated in terms of bandwidth and storage savings. Results demonstrate that forecasting Catch-up TV demand is practical, suitable for integration in OTT solutions, and useful in improving efficiency, with benefits to operators and consumers. Significant savings in bandwidth and storage are shown to be achievable, enabling green and cost-effective resource usage.     

A keyword-based semantic prefetching approach in Internet news services

Prefetching is an important technique to reduce the average Web access latency. Existing prefetching methods are based mostly on URL graphs. They use the graphical nature of HTTP links to determine the possible paths through a hypertext system. Although the URL graph-based approaches are effective in prefetching of frequently accessed documents, few of them can prefetch those URLs that are rarely visited. The paper presents a keyword-based semantic prefetching approach to overcome the limitation. It predicts future requests based on semantic preferences of past retrieved Web documents. We apply this technique to Internet news services and implement a client-side personalized prefetching system: NewsAgent. The system exploits semantic preferences by analyzing keywords in URL anchor text of previously accessed documents in different news categories. It employs a neural network model over the keyword set to predict future requests. The system features a self-learning capability and good adaptability to the change of client surfing interest. NewsAgent does not exploit keyword synonymy for conservativeness in prefetching. However, it alleviates the impact of keyword polysemy by taking into account server-provided categorical information in decision-making and, hence, captures more semantic knowledge than term-document literal matching methods. Experimental results from daily browsing of ABC News, CNN, and MSNBC news sites for a period of three months show an achievement of up to 60 percent hit ratio due to prefetching.     

Interactive TV: VoD meets the Internet

As broadband enters more and more homes, it will allow television to become an e-commerce medium - merging video, voice and transactional data in "television commerce" (t-commerce). T-commerce combines the interactive power of the Internet with traditional TV programming. The driving force behind t-commerce is interactive TV technology     

Large-scale multimedia content delivery over optical networks for interactive TV services

iTVP is a system built for delivery of live TV programming, video-on-demand and audio-on-demand with interactive access over IP networks. It has a nationwide range and is designed to provide service to a high number of concurrent users. Hence, scalability is one of the most important issues. In this paper we described how scalability is achieved in a two-level hierarchical architecture of the delivery system. We present the principles of content caching mechanisms and the management of the resulting distributed content repository. The system is implemented and currently operates in a test installation. Although the range of the test system operations is limited, as far as the number of users and the size of the content repository is concerned, the experience gained with iTVP so far provides an insight into the expected prototype performance. We present a system performance evaluation and describe the experience gained during the iGrid demonstration.     

Toward a reference process for developing wireless Internet services

Wireless Internet services such as mobile Web applications promise an enormous market potential. The field is characterized by extreme time-to-market pressure and insufficient knowledge about development procedures and technical constraints. This results in insufficient guidance for project managers and software developers on selecting appropriate development processes, techniques, methods, and tools. In addition, there is an enormous lack of knowledge about the effects (such as effort consumption, defect injection) of such technologies that hinders the transfer of innovative technologies into practice. This article describes an initial reference process by summarizing essential technologies for the development of wireless Internet services and experience with these technologies on the levels of life cycle processes, engineering processes, and managerial processes. The reference process is based on a comprehensive literature survey and the execution of development projects for wireless Internet services. The goal of the article is to provide domain-specific guidance for project managers and software developers with accompanying lessons learned from the past.     

A dynamic assignment scheduling algorithm for big data stream processing in mobile Internet services

As the huge number of mobile devices (e.g., smart phones, tablets and netbooks) increases, more and more people choose to use the Internet services financed by mobile Internet service providers (MISPs). To provide better services, it is quite necessary for MISPs to analyze the information hidden in the big data stream generated by users. Therefore, processing the real-time big data stream efficiently has become increasingly important. However, traditional static data storage technology fails to meet the demands of real-time data processing. To improve processing capacity, many parallel processing structures are proposed, which brings up the problem about how the parallel devices can be scheduled to maximize their efficiency. Accordingly, a dynamic assignment scheduling algorithm for big data stream processing in mobile Internet services is proposed, and a stream query graph is built to calculate the weight of every edge. The edge with the minimum weight is selected to send tuples. Simulation results show that the proper number of the logic devices can dramatically reduce system response time. Furthermore, system context switching is reduced by increasing the number of tuples sent each time.     

液压管路压力非插入式超声检测新技术

实现液压管路压力的非插入式检测 ,对于液压系统快速故障定位具有重要意义。基于油液声学特性 ,利用超声技术实现压力的非插入式检测是一种有效的方法。重点论述声速测压法检测系统设计及综合校正模型等内容