With the emergence of peer-to-peer video-on-demand systems, new avenues for keeping track of and subsequently meeting user needs and desires have arisen. Based on the idea of contextual priming, we introduce a new frame-work, SUE, that takes advantage of the intimate level of user profiling afforded by the internet as well as the linear and segmented nature of p2p technology to determine a user's exact on-screen experience at any given time interval. This allows us to more accurately determine the type of information a user is likely to be more receptive to. Our design differs from other existing systems in two ways: (a) the level of granularity it can support, accommodating factors from both the user's on-screen and physical environment in making its recommendations and (b) in addressing some of the shortcomings seen in current applications, such as those imposed by coarse user profiling and faulty associations. In order to examine the viability of our framework, we provide a high level design specifying its incorporation into an existing p2p video system, the BitVampire project.

With the emergence of peer-to-peer video-on-demand systems, new avenues for keeping track of and subsequently meeting user needs and desires have arisen. Based on the idea of contextual priming, we introduce a new frame-work, SUE, that takes advantage of the intimate level of user profiling afforded by the internet as well as the linear and segmented nature of p2p technology to determine a user's exact on-screen experience at any given time interval. This allows us to more accurately determine the type of information a user is likely to be more receptive to. Our design differs from other existing systems in two ways: (a) the level of granularity it can support, accommodating factors from both the user's on-screen and physical environment in making its recommendations and (b) in addressing some of the shortcomings seen in current applications, such as those imposed by coarse user profiling and faulty associations. In order to examine the viability of our framework, we provide a high level design specifying its incorporation into an existing p2p video system, the BitVampire project.

Univ., Diss.--Stuttgart. / Parallelsacht.: Modeling and performance evaluation of a distributed video on demand system for variable bit rate MPEG encoded video data streams.

With the emergence of peer-to-peer video-on-demand systems, new avenues for keeping track of and subsequently meeting user needs and desires have arisen. Based on the idea of contextual priming, we introduce a new frame-work, SUE, that takes advantage of the intimate level of user profiling afforded by the internet as well as the linear and segmented nature of p2p technology to determine a user's exact on-screen experience at any given time interval. This allows us to more accurately determine the type of information a user is likely to be more receptive to. Our design differs from other existing systems in two ways: (a) the level of granularity it can support, accommodating factors from both the user's on-screen and physical environment in making its recommendations and (b) in addressing some of the shortcomings seen in current applications, such as those imposed by coarse user profiling and faulty associations. In order to examine the viability of our framework, we provide a high level design specifying its incorporation into an existing p2p video system, the BitVampire project. / Science, Faculty of / Computer Science, Department of / Graduate

With the emergence of cloud computing, many applications are migrated onto clouds. Video-on-demand (VoD) can be implemented on the cloud platform with geo-distributed cloud servers to serve worldwide users. New videos are distributed to these geo-distributed cloud servers. This distribution should be properly scheduled based on the videos' sizes, videos' popularities and the available network bandwidth, so that the mean completion time is minimized. We formulate this problemas a preemptive scheduling problem, prove that it is NP-hard, and design a heuristic scheduling algorithm to solve it. This algorithm iteratively determines: 1) themost preferred file to be received by the most preferred destination server by pairwise analysis and PageRank, and 2) the most preferred source servers which can transmit this file to the most preferred destination server with appropriate data rates. The simulation results demonstrate that the proposed scheduling algorithm gives much smaller mean completion time than four scheduling algorithms.

<p>The purpose of this essey is through empirical methods investigate usability factors on Video On Demand applications for the Internet. More specificly we will focus on a application called Voddler. The purpose is to identify usability problems that exist in Voddler, and present the reader with suggestions on possible solutions. This could be used as guidelines to how to design for usability in this kind of system. We will use an online survey to investigate Voddler usability and use this data as a basis for our analysis. We will also conduct a expert evaluation of the system. The data collected from the survey will be compared to the expert evalutation and different theories behind usability. We will come to the conclusion that through a usability perspective Voddler has designed the software as an interactive Video On Demand service meanwhile the target audience want the application to function more like an normal computer program. This causes a conflict between the two that has to be resolved if one wants to optimize usability this kind of software.</p>

The purpose of this essey is through empirical methods investigate usability factors on Video On Demand applications for the Internet. More specificly we will focus on a application called Voddler. The purpose is to identify usability problems that exist in Voddler, and present the reader with suggestions on possible solutions. This could be used as guidelines to how to design for usability in this kind of system. We will use an online survey to investigate Voddler usability and use this data as a basis for our analysis. We will also conduct a expert evaluation of the system. The data collected from the survey will be compared to the expert evalutation and different theories behind usability. We will come to the conclusion that through a usability perspective Voddler has designed the software as an interactive Video On Demand service meanwhile the target audience want the application to function more like an normal computer program. This causes a conflict between the two that has to be resolved if one wants to optimize usability this kind of software.

<p>In recent years, with the fast development of resource capability of both the Internet and personal computers, multimedia applications like video-on-demand (VOD) streaming have gained dramatic growth and been shown to be potential killer applications in the current and next-generation Internet. Scalable deployment of these applications has become a hot problem area due to the potentially high server and network bandwidth required in these systems.</p><p>The conventional approach in a VOD streaming system dedicates a media stream for each client request, which is not scalable in a wide-area delivery system serving potentially very large numbers of clients. Recently, various efficient delivery techniques have been proposed to improve the scalability of VOD delivery systems. One approach is to use a scalable delivery protocol based on multicast, such as periodic broadcast or stream merging. These protocols have been mostly developed for single-server based systems and attempt to have each media stream serve as many clients as possible, so as to minimize the required server and network bandwidth. However, the performance improvements possible with techniques that deliver all streams from a single server are limited, especially regarding the required network bandwidth. Another approach is based on proxy caching and content replication, such as in content delivery networks (CDN). Although this approach is able to effectively distribute load across multiple CDN servers, the cost of this approach may be high.</p><p>With the focus on further improving the system efficiency regarding the server and network bandwidth requirement, a new scalable streaming protocol is developed in this work. It adapts a previously proposed technique called hierarchical multicast stream merging (HMSM) to use a peer-to-peer delivery approach. To be more efficient in media delivery, the conventional early merging policy associated with HMSM is extended to be compatible with the peer-to-peer environment, and various peer selection policies are designed for initiation of media streams. The impact of limited peer resource capability is also studied in this work. In the performance study, a number of simulation experiments are conducted to evaluate the performance of the new protocol and various design policies, and promising results are reported.

Peer-assisted Video-on-Demand (VoD) systems have not only received substantial recent research attention, but also been implemented and deployed with success in large-scale real-world streaming systems. Despite the remarkable popularity in real-world systems, the design of such systems are not well understood. In this thesis, we seek to address two design problems in peer-assisted VoD systems. First, we focus on the design of cache replacement algorithms. We construct an analytical framework based on dynamic programming, to help us form an in-depth understanding of optimal strategies to design cache replacement algorithms. Second, we shift our attention to the surplus upload bandwidth allocation problem in multi-channel systems. Through theoretical analysis and realistic simulations, we conclude that surplus upload bandwidth from peers can be utilized more efficiently than conventional prefetching strategies when it is devoted to redistributing content to those channels in deficit state.

Peer-assisted Video-on-Demand (VoD) systems have not only received substantial recent research attention, but also been implemented and deployed with success in large-scale real-world streaming systems. Despite the remarkable popularity in real-world systems, the design of such systems are not well understood. In this thesis, we seek to address two design problems in peer-assisted VoD systems. First, we focus on the design of cache replacement algorithms. We construct an analytical framework based on dynamic programming, to help us form an in-depth understanding of optimal strategies to design cache replacement algorithms. Second, we shift our attention to the surplus upload bandwidth allocation problem in multi-channel systems. Through theoretical analysis and realistic simulations, we conclude that surplus upload bandwidth from peers can be utilized more efficiently than conventional prefetching strategies when it is devoted to redistributing content to those channels in deficit state.