基于SIP的集中式多媒体会议系统的研究

基于IP网络的多媒体会议系统是一个重要的研究课题。该文通过对各种会议拓扑结构的分析和比较,提出了一种以SIP作为控制信令的、集中式拓扑结构的多媒体会议系统。在给出了系统的框架结构之后,该文研究了如何扩展基本的SIP协议来完成会议控制的功能,并针对几种常用的会议控制功能,给出了详细的控制机制。     

虚拟会议空间的研究与实现

支持协同工作的虚拟环境是当前虚拟现实技术研究的热点,虚拟会议空间能提供无缝的会场环境、眼神接触、凝视感知等普通多媒体会议系统不具备的虚拟协同工作环境。介绍了已成功鉴定的虚拟空间会议系统VST中虚拟会议空间的构造模型与实现方法。     

混合型会议电视系统的设计与实现

文章首先就混合型会议电视系统的关键技术——卫星会议网控系统的设计与实现方法进行了探讨,并对混合型会议电视系统的组成、卫星载波的分配和会议过程的控制进行了设计,同时简要介绍了已研制开发的会议编解码终端和网技设备及其基本功能。     

基于SIP集中式多媒体视频会议系统中对私下会议问题的研究

私下会议(Sidebar)指的是会议中若干与会者在不退出目前会议的情况下,组成一个私下的小规模会议,这项特性有很强的使用价值,在IETF的XCON工作组中提出了该问题,但目前尚无专门的草案探讨其实现方式。本文在基于SIP集中式多媒体会议系统上,利用二次媒体流混合,提出了自己的解决方案。     

基于企业知识形成过程的会议系统研究

会议正日益成为企业运作管理与企业知识形成的重要途径，良好的会议管理对企业具有重大的意义。针对现阶段会议管理普遍存在的问题，通过分析企业知识形成的过程，提出了一种会议模型。在此基础上设计一个会议系统，不但能够对会议的议题、文档、记录、决议等相关信息进行统一管理，而且还构建了会议知识库以实现会议知识的查询与回溯，从而提高了企业知识形成的效率，并能够更有效地应用会议知识。     

基于企业知识形成过程的会议系统研究

会议正日益成为企业运作管理与企业知识形成的重要途径,良好的会议管理对企业具有重大的意义。针对现阶段会议管理普遍存在的问题,通过分析企业知识形成的过程,提出了一种会议模型。在此基础上设计一个会议系统,不但能够对会议的议题、文档、记录、决议等相关信息进行统一管理,而且还构建了会议知识库以实现会议知识的查询与回溯,从而提高了企业知识形成的效率,并能够更有效地应用会议知识。     

基于JAIN SIP的多媒体会议用户代理设计

会议初始化（SIP）协议是下一代网络应用层的核心控制协议。JAIN SIP是SUN公司用于实现SIP应用而提供的一套标准Java接口。文章提出了一个基于JAIN SIP的多媒体会议用户代理的框架，对每一层的功能模块进行了详细分析，包括JAIN SIP协议栈的体系结构、用户代理控制部分信令（创建会议、加入会议、删除会议等）、媒体信息处理等。用JAIN SIP开发基于SIP协议的应用不仅可以提高开发效率，而且将使应用程序获得较高的可靠性和较好的移植性。     

计算机会议系统流结合模型的研究

流结合是开放分布式处理参考模型的一个重要概念本文首次以计算机会议流结合作为基本模式，采用ＯＤＰ的五各观点方法系统地研究了一个分布式会议系统。文中提出会议流结合模型的概念，分别从企业，信息，计算，工程和技术各个分面式会议系统。文中提出会议流结合模型的概念，分别从企业，信息，计算，工程和技术各个层面突出了会议系统的信息流结构及其交互特性，从而成为会议系统实现模型的基础。     

基于SIP的集中式会议控制模型及实现

在前人研究的基础上提出了一种独立于应用的、适用于集中式会议的会议控制模型。模型包括会议配置、用户管理、Floor control、应用会话管理和网络管理各组件,采用了SIP协议作为会话控制协议。会议控制消息分为命令和通知两种。会议命令使用SOAP协议实现,会议消息采用了SIP事件通知机制。该会议控制模型被成功地应用于基于SIP的实时多媒体视频会议系统。实践表明,该会议控制模型是合理的、有效的。     

基于SSH的会议管理系统

介绍一种会议管理系统的开发,可实现网上会议申请、批准会议、管理会议室、指定会议管理员等功能。系统采用流行的SSH框架组合,具有较好的可维护性,可以实现单位与会议有关资源的合理安排,充分发挥会议资源的作用。     

Fast Motion Estimation Algorithm with Edge Alignment for H.264 Encoder

Image sequences processing and video encoding are extremely time consuming problems. The time complexity of them depends on image contents. This paper presents an estimation of a block motion method for video coding with edge alignment. This method uses blocks of size 4 × 4 and its basic idea is to find motion vector using the edge position in each video coding block. The method finds the motion vectors more accurately and faster than any known classical method that calculates all the possibilities. Our presented algorithm is compared with known classical algorithms using the evaluation function of the peak signal-to-noise ratio. For comparison of the methods we are using parameters such as time, CPU usage, and size of compressed data. The comparison is made on benchmark data in color format YUV. Results of our proposed method are comparable and in some cases better than results of standard classical algorithms.     

ITC is Cool

ITC is cool. How can this be, you ask? This is the International Test Conference's 36th year, which makes it a middle-aged conference; and, as anyone who has ever been middle-aged knows, being cool at this time of life is a serious challenge. ITC doesn't try to be cool, at least not in the way that, say, Macworld does. ITC tries instead to be interesting, innovative, and informative. All three of these qualities are vital for a successful conference.     

Social interaction with robots: three questions

Robots are coming into different spheres of our daily lives, and therefore it is important that we now reflect systematically and in a comprehensive and inclusive way on the effects this may have on human interactions with other people and with machines. In Delmenhorst we held the conference “Going beyond the Laboratory.” Reflecting on the discussions of the conference, the editorial team realized a conceptual gap between the engineering sciences on the one hand and the social sciences and philosophy on the other hand. In order to initiate first steps in the direction of overcoming this divide, the editorial team decided to put forth three questions crucial for the issue of social interaction with robots and collected answers by experts in different robotics research projects. The questions are: How are we to understand the term robot autonomy in robotics and in social life? How is the idea of robot autonomy related to the limits of mathematization? I.e. is it possible, to fully express mathematically processes of social interaction? And finally, how are interactions between humans and robots in everyday life related to social institutions on a micro- and macro-level?     

利用多模态机器注意改善视频会议用户感受

远程视频会议的应用已很多年了,但是,目前的视频会议系统对使用者的限制较多,往往需要使用者对系统保持关注方可正常使用。如何通过改善视频会议系统的人机交互模式来改善用户感受是视频会议系统进一步完善的重要途径。多模态机器注意技术来自于仿生学的研究成果,本文通过对基于多模态信息集成和同步来实现机器注意技术的讨论,将这种技术用于改进视频会议系统的人机交互模式,通过使视觉、听觉信号集成和同步的方法实现人工系统中视觉关注于感兴趣的对象——发言人的脸部及其发言。改进后的系统大大减少了发言人受到的约束,能够准确地自动跟踪发言人,而且在画面上更加突出视频会议画面中感兴趣的对象。     

Conferences as learning communities: some early lessons in using ‘back-channel’ technologies at an academic conference – distributed intelligence or divided attention?

Abstract Most, if not all, researchers attend conferences as a part of their practice, and yet it is an under-researched activity. Little attention has been paid either to developing a theoretically informed understanding of conference practice as knowledge building, or to assessing the extent to which conferences are successful. This paper addresses these issues in the context of a small empirical study of the introduction of mobile, interactive (‘back-channel’) technologies into a conference setting. Science studies and learning theories literatures are used to develop an eight-point statement describing the aims of an idealised conference. This is then used as a framework through which to make sense of what happened when ‘back-channel’ technologies such as internet relay chat (IRC) and blogging were introduced into the 2004 Colston Symposium ‘The Evolution of Learning and Web Technologies: Survival of the Fittest?’. Focusing on sequential issues and the conference as a forum for knowledge building, the analysis shows that conference order is disrupted by the introduction of the back-channel technologies. Nevertheless, other pressures on academic and professional practice (the governance agenda, calls for greater collaboration and a more consensual approach, and so on) suggest that the potential of the new technologies to help open up the black box of scientific and professional practice will be seen as increasingly important. If these tools are to be used effectively in the future, conferences will need to be supported by new skills and practices.     

Not every domain of a plain decompressor contains the domain of a prefix-free one

C. Calude, A. Nies, L. Staiger, and F. Stephan posed the following question about the relation between plain and prefix Kolmogorov complexities (see their paper in DLT 2008 conference proceedings): does the domain of every optimal decompressor contain the domain of some optimal prefix-free decompressor? In this paper we provide a negative answer to this question.     

基于SIP的多媒体会议框架研究与实现

针对SIP多媒体会议框架中若干高级问题进行一定深度和广度的探讨,并针对相应问题提出了有效可行的解决方案。其中主要论述了6个方面的问题,会议类型,加入会议,获取会议信息,创建了会议,媒体混合布局,会议集联,然后结合作者实际项目经验,探讨了SIP多媒体会议系统实现的总体架构,以及SIP会议系统核心部件Focus的实现。     

On optimization of expertise matching with various constraints

This paper studies the problem of expertise matching with various constraints. Expertise matching, which aims to find the alignment between experts and queries, is a common problem in many applications such as conference paper-reviewer assignment, product-reviewer alignment, and product-endorser matching. Most existing methods formalize this problem as an information-retrieval problem and focus on finding a set of experts for each query independently. However, in real-world systems, various constraints are often needed to be considered. For example, in order to review a paper, it is desirable that there is at least one senior reviewer to guide the reviewing process. An important question is: “Can we design a framework to efficiently find the optimal solution for expertise matching under various constraints?” This paper explores such an approach by formulating the expertise matching problem in a constraint-based optimization framework. In the proposed framework, the problem of expertise matching is linked to a convex cost flow problem, which guarantees an optimal solution under various constraints. We also present an online matching algorithm to support incorporating user feedbacks in real time. The proposed approach has been evaluated on two different genres of expertise matching problems, namely conference paper-reviewer assignment and teacher-course assignment. Experimental results validate the effectiveness of the proposed approach. Based on the proposed method, we have also developed an online system for paper-reviewer suggestions, which has been used for paper-reviewer assignment in a top conference and feedbacks from the conference organizers are very positive.     

基于组播的多点会议及其SIP扩展研究

Internet草案对于如何扩展SIP作了规定,在对多媒体会议的支持方面,通常都通过SIP的扩展来实现,但这些扩展采用单个会议成员服务器来保存会议成员状态,限制了会议系统的可控制性。该文主要针对该局限性,通过结合多媒体多点会议的组播模型,提出了一种支持多点会议的SIP协议扩展方法,并就该方法在保持会议成员一致性方面做了研究。