多媒体协作平台中录制系统的研究与实现

在多媒体协作平台中,录制系统将实时协作过程中的音视频数据存储下来,用户通过回放可以重温整个会话过程。文中针对录制系统数据量大、实时性高、并发访问多的特点,研究并实现了一个实时多媒体录制系统。就缓冲管理、存储策略、会话管理等关键问题进行了分析并给出了解决方案。另外,为了提高系统各节点利用率和自适应性,提出了基于预测和负载反馈的动态负载平衡机制以及录制任务迁移策略。     

基于Flex、Red5和MongoDB的视频直播、录制及存储系统设计

为改善以往网络视频直播或点播过程中播放不流畅的情况和寻找大量视频数据的存储策略,提出了一种实时的视频直播、录制及存储系统的整体设计方案。利用开源的流媒体服务器Red5结合富互联网技术Flex实现直播和录制;通过开源NoSQL数据库MongoDB将录制的视频数据进行存储。实际测试结果表明,该平台能满足系统在多用户访问和数据存储方面的要求。     

基于Flex、Red5和MongoDB的视频直播、录制及存储系统设计

为改善以往网络视频直播或点播过程中播放不流畅的情况和寻找大量视频数据的存储策略,提出了一种实时的视频直播、录制及存储系统的整体设计方案。利用开源的流媒体服务器Red5结合富互联网技术Flex实现直播和录制;通过开源NoSQL数据库MongoDB将录制的视频数据进行存储。实际测试结果表明,该平台能满足系统在多用户访问和数据存储方面的要求。     

基于JMF的音视频实时交互及存储的具体实现

针对目前多媒体远程教学及实时监控系统大部分是信息单向传输，缺乏用户间的多媒体信息实时交互功能及多媒体数据存储海量的弊端，文章提供了一种用JMF的数据克隆、数据轨道控制、流媒体的存储及传输等技术来实现网络音、视频数据双向传输及由用户选择和控制将音视频数据以MOV文件格式存储到本地硬盘的方案，并介绍了实现方法。系统软、硬件成本低，且数据量小，易于网络传输和存储。     

一种基于中间件的授权管理体系结构

近年来，授权策略的研究取得诸多进展。但是，在应用系统中实施这些策略还需大量具有共性和挑战性的工作。本文将对象中间件技术同信任管理技术有机地结合起来，定义了面向中间件的授权策略框架MPF，然后提出一种通用中间件授权管理体系结构StarNumen。StarNumen将授权同应用组件分离，以策略驱动或透明的方式为应用系统提供授权策略描述、策略存储、会话管理等多种具有通用性的授权机制。模拟测试结果说明了StarNumen的可行性和有效性。     

下一代网络多媒体会话中H.248与SIP之间协议协作的研究

H.248和SIP是下一代电信网络的两个核心协议,通过H.248和SIP之间的协作来完成多媒体会话的建立、调整和删除是在下一代网络中实现多媒体业务需面临的重要问题。文章在深入研究H.248和SIP协议的基础上针对协议协作的应用环境抽象了一个协作模型。依据此模型,对两方多媒体会话和多方多媒体会话中各信令交互阶段H.248和SIP之间的协作进行了详细阐述。对H.248和SIP协议之间协作的研究可以应用到下一代电信网络的工程技术领域。     

基于IP组播的网络多媒体教学系统的设计与实现

IP组播是IP领域的最新技术，它为网络实时多媒体传输和批量数据传输提供了解决方法。设计并实现了一个基于IP组播的纯软件的网络多媒体教学系统，该系统能保证传输流的服务质量，能有效地拓展会话节点的规模。     

群组协作模式下的网络视频会议系统

针对群组协作模式下多学科协同产品设计过程的需求,开发一个纯软件的多点网络视频会议系统.采用类B/S结构设计.基于Java媒体框架(JMF)和流媒体技术,完成系统框架设计、功能设计和媒体流交互过程的管理与控制机制,并实现与产品数据管理(PDM)系统的集成.系统提供了多学科协同过程知识交流与共享、设计冲突消解的实时多媒体应用环境.     

全自动网络录播系统分析

教室教学设备的建设和网络系统的完善,全自动网络录播系统为精品课、公开课、研究课、讲座、大会讲话进行录制,制成单画面电影模式和多画面资源模式和实时播出,搭建实时和非实时的远程视频教学系统,利用网络进行大面积的教学,缓解师资压力,充分发挥优秀教师的示范作用,数字化存储优秀教师的教学成果和方便地建立课件管理及点播系统奠定了基础。     

基于实时多媒体流的预取算法研究

实时多媒体应用存在严格的时间限制。存储访问时延是影响系统性能的一个最关键问题,针对实时多媒体数据而言,基于传统数据的LRU及其改进算法上的的预取和置换策略已经不能满足实际QoS要求。该文针对实时多媒体流,建立终端环境下的实时媒体对象的任务路径树模型,并给出该模型下的媒体流的预取和置换算法MO-VFT。实验模拟结果表明,所提出的模型合理,算法负载小,性能提高达20～35%。     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.