Video data location plays a key role for Peer-to-Peer （P2P） live streaming applications. In this paper, we propose a new one-hop Distributed Hash Table （DHT） lookup frarrework called Strearre ing-DHT （SDHT） to p...Video data location plays a key role for Peer-to-Peer （P2P） live streaming applications. In this paper, we propose a new one-hop Distributed Hash Table （DHT） lookup frarrework called Strearre ing-DHT （SDHT） to provide efficient video data location service. By adopting an enhanced events dissemination mechanism-EDRA＋, the accuracy of routing table at peers can be guaranteed. More importantly, in order to enhance the perforlmnce of video data lookup operation without incurring extra overhead, we design a so-called Distributed Index Mapping and Management Mechanism （DIMM） for SDHT. Both analytical modeling and intensive simulation experiments are conducted to demonstrate the effectiveness of SDHT framework. Numerical results show that almost 90% requested video data can be retrieved within one second in SDHT based systems, and SDHT needs only 26% average bandwidth consumption when compared with similar one-hop DHT solutions such as D1HT. This indicates that SDHT framework is an appropriate data lookup solution for time-sensitive network applications such as P2P live streaming.展开更多
Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad dela...Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad delay performance. In this paper, we seek to improve the delay performance under ensuring video display quality stemming from chunk scheduling. And so we model Pull-based chunk scheduling problem as a multi-objective optimization problem to minimize the video delay and maximize video display quality in the environment of heterogeneous upload bandwidths, heterogeneous and dynamic propagation delays. Finally we put up with a greedy Pull-based scheduling approach(GPSA) to solve the optimization problem. The evaluation shows GPSA can outperform two classical chunk scheduling approaches and adapt to dynamic variance of propagation delays.展开更多
In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and...In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and Distributed Hash Table(DHT) based P2P streaming system,called HQMedia,to provide high playback quality to users by maintaining high data dissemination resilience with a low overhead.In HQMedia,peers are classified into Super Peers(SP) and Common Peers(CP) according to their online time.SPs and CPs form a mesh structure,while SPs alone form a new Streaming DHT(SDHT) structure.In this hybrid architecture,we propose a joint scheduling and compensation mechanism.If any frames cannot be obtained during the scheduling phase,an SDHT-based compensation mechanism is invoked for retrieving the missing frames near the playback point.We evaluate the performance of HQMedia by both theoretical analysis and intensive simulation experiments on large-scale networks to demonstrate the effectiveness and scalability of the proposed system.Numerical results show that HQMedia significantly outperforms existing mesh-based and treebased P2P live streaming systems by improving playback quality with only less than 1% extra maintenance overhead.展开更多
对于日益发展的移动互联网来说,流媒体是其最重要最有需求和市场的应用之一。本论文以Http Live Streaming技术为背景,详细介绍了Android平台架构和Android NDK开发,并在此基础上介绍并设计了移动流媒体直播系统,实现了无线网络视频的...对于日益发展的移动互联网来说,流媒体是其最重要最有需求和市场的应用之一。本论文以Http Live Streaming技术为背景,详细介绍了Android平台架构和Android NDK开发,并在此基础上介绍并设计了移动流媒体直播系统,实现了无线网络视频的传输。最后,通过性能测试,实现了客户端采集编码功能。展开更多
目的探讨六西格玛(lean six sigma,LSS)管理在国家区域医疗中心建设背景下“直播+科普”跨界模式中的应用效果。方法运用LSS管理方法中的界定、测量、分析、改进和控制5个阶段对国家区域医疗中心建设背景下“直播+科普”跨界模式应用中...目的探讨六西格玛(lean six sigma,LSS)管理在国家区域医疗中心建设背景下“直播+科普”跨界模式中的应用效果。方法运用LSS管理方法中的界定、测量、分析、改进和控制5个阶段对国家区域医疗中心建设背景下“直播+科普”跨界模式应用中的管理难点进行分析,采用头脑风暴、根因分析等方法分析影响“直播+科普”跨界模式的关键环节,提出解决方案,建立规范性运行机制,比较实施前后“直播+科普”累计播放量、累计点赞量、留言互动量变化;辖区内居民健康教育知晓率、满意度及慢性病患者再入院率变化。结果运用LSS管理后,科普直播累计播放量、累计点赞量、留言互动量显著增长;辖区内居民健康教育知识知晓率、健康科普满意度显著提升;全院慢性病患者再入院率下降,差异有统计学意义(P<0.05)。结论LSS管理可有效提高“直播+科普”跨界模式质量,辖区内居民健康素养增强,慢性病患者再入院率降低。展开更多
基金Acknowledgements This work was supported by the Key Projects for Science and Technology Development under Caant No. 2009ZX03004-002 the National Natural Science Foundation of China under Gants No. 60833002, No. 60772142+1 种基金 the National Science and Technology Fundamental Project under Grant No. 2008ZX03003-005 the Science ＆ Technology Research Project of Chongqing Education Committee under Crant No. KJ120825.
文摘Video data location plays a key role for Peer-to-Peer （P2P） live streaming applications. In this paper, we propose a new one-hop Distributed Hash Table （DHT） lookup frarrework called Strearre ing-DHT （SDHT） to provide efficient video data location service. By adopting an enhanced events dissemination mechanism-EDRA＋, the accuracy of routing table at peers can be guaranteed. More importantly, in order to enhance the perforlmnce of video data lookup operation without incurring extra overhead, we design a so-called Distributed Index Mapping and Management Mechanism （DIMM） for SDHT. Both analytical modeling and intensive simulation experiments are conducted to demonstrate the effectiveness of SDHT framework. Numerical results show that almost 90% requested video data can be retrieved within one second in SDHT based systems, and SDHT needs only 26% average bandwidth consumption when compared with similar one-hop DHT solutions such as D1HT. This indicates that SDHT framework is an appropriate data lookup solution for time-sensitive network applications such as P2P live streaming.
基金supported by National Key Basic Research Program of China(973 Program)(2009CB320504)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 60821001)+1 种基金Beijing Municipal Commission of Education to build the project special,Research Fund for the Doctoral Program of Higher Education of China (20090005120012)National Natural Science Foundation (60672121)
文摘Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad delay performance. In this paper, we seek to improve the delay performance under ensuring video display quality stemming from chunk scheduling. And so we model Pull-based chunk scheduling problem as a multi-objective optimization problem to minimize the video delay and maximize video display quality in the environment of heterogeneous upload bandwidths, heterogeneous and dynamic propagation delays. Finally we put up with a greedy Pull-based scheduling approach(GPSA) to solve the optimization problem. The evaluation shows GPSA can outperform two classical chunk scheduling approaches and adapt to dynamic variance of propagation delays.
基金supported by the National Programs for Science and Technology under Grant No. 2009ZX03004-002the National Natural Science Foundation of China Major Project under Grant No. 60833002+2 种基金the National Natural Science Foundation of China under Grant No.60772142the National Science and Technology Major Projects under Grant No. 2008ZX03003-005the Science and Technology Research Project of Chongqing Education Commission under Grant No. KJ120825
文摘In Peer-to-Peer(P2P) streaming systems,video data may be lost since peers can join and leave the overlay network randomly,thereby deteriorating the video playback quality.In this paper we propose a new hybrid mesh and Distributed Hash Table(DHT) based P2P streaming system,called HQMedia,to provide high playback quality to users by maintaining high data dissemination resilience with a low overhead.In HQMedia,peers are classified into Super Peers(SP) and Common Peers(CP) according to their online time.SPs and CPs form a mesh structure,while SPs alone form a new Streaming DHT(SDHT) structure.In this hybrid architecture,we propose a joint scheduling and compensation mechanism.If any frames cannot be obtained during the scheduling phase,an SDHT-based compensation mechanism is invoked for retrieving the missing frames near the playback point.We evaluate the performance of HQMedia by both theoretical analysis and intensive simulation experiments on large-scale networks to demonstrate the effectiveness and scalability of the proposed system.Numerical results show that HQMedia significantly outperforms existing mesh-based and treebased P2P live streaming systems by improving playback quality with only less than 1% extra maintenance overhead.
文摘对于日益发展的移动互联网来说,流媒体是其最重要最有需求和市场的应用之一。本论文以Http Live Streaming技术为背景,详细介绍了Android平台架构和Android NDK开发,并在此基础上介绍并设计了移动流媒体直播系统,实现了无线网络视频的传输。最后,通过性能测试,实现了客户端采集编码功能。
文摘目的探讨六西格玛(lean six sigma,LSS)管理在国家区域医疗中心建设背景下“直播+科普”跨界模式中的应用效果。方法运用LSS管理方法中的界定、测量、分析、改进和控制5个阶段对国家区域医疗中心建设背景下“直播+科普”跨界模式应用中的管理难点进行分析,采用头脑风暴、根因分析等方法分析影响“直播+科普”跨界模式的关键环节,提出解决方案,建立规范性运行机制,比较实施前后“直播+科普”累计播放量、累计点赞量、留言互动量变化;辖区内居民健康教育知晓率、满意度及慢性病患者再入院率变化。结果运用LSS管理后,科普直播累计播放量、累计点赞量、留言互动量显著增长;辖区内居民健康教育知识知晓率、健康科普满意度显著提升;全院慢性病患者再入院率下降,差异有统计学意义(P<0.05)。结论LSS管理可有效提高“直播+科普”跨界模式质量,辖区内居民健康素养增强,慢性病患者再入院率降低。
