Peer-to-Peer Networks and Computation: Current Trends and Future Perspectives

This research papers examines the state-of-the-art in the area of P2P networks/computation. It attempts to identify the challenges that confront the community of P2P researchers and developers, which need to be addressed before the potential of P2P-based systems, can be effectively realized beyond content distribution and file-sharing applications to build real-world, intelligent and commercial software systems. Future perspectives and some thoughts on the evolution of P2P-based systems are also provided

Taxonomy of P2P Applications

Peer-to-peer (p2p) networks have gained immense popularity in recent years and the number of services they provide continuously rises. Where p2p-networks were formerly known as file-sharing networks, p2p is now also used for services like VoIP and IPTV. With so many different p2p applications and services the need for a taxonomy framework rises. This paper describes the available p2p applications grouped by the services they provide. A taxonomy framework is proposed to classify old and recent p2p applications based on their characteristics

Multiple description image and video coding for P2P transmissions

Peer-to-Peer (P2P) media streaming is, nowadays, a very attractive topic due to the bandwidth available to serve demanding content scales. A key challenge, however, is making content distribution robust to peer transience. Multiple description coding (MDC) has, indeed, proven to be very effective with problems concerning the packets’ losses, since it generates several descriptions and may reconstruct the original information with any number of descriptions that may reach the decoder. Therefore multiple descriptions may be effective for robust peer-to-peer media streaming. In this dissertation, it will not only be showed that, but also that varying the redundancy level of description on the fly may lead to a better performance than the one obtained without varying this parameter. Besides that, it is shown, as well, that varying the Bitrate on the fly outperforms the redundancy on it. Furthermore, the redundancy and the Bitrate were varied simultaneously. Thus, it is shown that this variation is more efficient when the packet loss is high. The experiments reported above were done using an experimental test bed developed for this purpose at the NMCG lab of the University of Beira Interior. It was also used the REGPROT, a video encoder developed by our research team, to splitted the video into multiple descriptions, which were, later, distributed among the peers in the test bed. After the request of the client, the referred encoder decoded the descriptions as they were being received.Fundação para a Ciência e a Tecnologia (FCT

Compact tree plus algorithms for application-level multicast communications in multihome networks

Application-level multicast (ALM) communications replicate packets on host level to deliver them from a single source to multiple clients, so that it can efficiently realize a variety of network applications using moving pictures such as video conferences, distance learning, and video-on-demands. In this paper, we propose the CT+ (compact tree plus) algorithm for finding a better ALM routing tree in terms of delay minimization between hosts. CT+ consists of a tree construction stage from the existing CT algorithm, and a newly added iterative tree improvement stage. Then, we define the extended ALM routing problem and its heuristic algorithm ExCT+, to optimize the effectiveness of the multihome network in ALM communications by selecting multihomed hosts and connections in the ALM routing tree simultaneously. For their evaluations, we construct a network simulation model named MINET (multiple-ISP network simulator), where the topology is composed of multiple ISP backbone networks with IX connections, and the network traffic is generated by following the M/M/1 queuing process. The simulation results using MINET verify the effectiveness of our algorithms.</p

FILE SHARING IN P2P SYSTEMS FOR THE EXPECTED HIGH CHURN

Most of the file sharing networks plays a major role in the current networking domain. On that the file sharing between the users is an important work takes place on those systems. When considering each of the system, the need is a performance improvement in the network. We address the problem of highly transient populations in unstructured and loosely structured peer-to-peer (P2P) systems. In existing system they consider the distributed system and causes collision while communication. But we consider centralized system and overcome the collision during file sharing and also the existing system drawbacks

Distributed construction of resource-efficient overlay tree by approximating MST

Master'sMASTER OF SCIENC

Pushing the button: Why do learners pause online videos?

With the recent surge in digitalization across all levels of education, online video platforms gained educational relevance. Therefore, optimizing such platforms in line with learners’ actual needs should be considered a priority for scientists and educators alike. In this project, we triangulate logfiles of a large German online video platform for educational videos with behavioral data from a laboratory study and the objective characteristics of the selected videos. We aim to understand the potential motives for why participants pause educational videos while watching such videos online. Our analyses revealed that perceived difficulties in comprehension and meaningful structural breakpoints in the videos were associated with increased pausing behavior. In contrast, pausing behavior was not associated with the videos’ formal structural features highlighted in the video platform. Implications of these findings and the potentials of our methodological approach for theory and practice are discussed. © 2021 The Author

Radio 2.0 in Higher Education Communities: An approximation of Aveiro University Members perceptions

The web 2.0 raises new challenges and opportunities in many different fields of activity, namely because it introduces different approaches and possibilities to the relationship among participants both at institutional and individual levels. On the Higher Education context many changes are occurring due to the introduction of new learning paradigms, many of them take advantage of web 2.0 technologies to configure more effective and diverse scenarios to support the work of students and teaching staff. Social networks are currently being adopted in many Higher Education communities as platforms to support the interaction among community members, taking advantage of the potential of those networks to foster strong and meaningful relationships and support the awareness and consolidation of group identity. This potential is being explored to promote new possibilities for teaching and learning that include new approaches such as the personal learning environments. This article addresses the potential that radio services have for Higher Education communities in a web 2.0, focusing on the case of the University of Aveiro (Portugal). The article explores the perceptions that Aveiro academic members have about webradio potentialities in terms of sense of belonging creation and community cohesion