In a large distributed system spanning many administrative domains such as a Grid, it is desirable to maintain and query dynamic and timely information about active participants such as services, resources and user communities. However, in such a database system, the set of information tuples in the universe is partitioned over one or more distributed nodes, for reasons including autonomy, scal...

Peer-to-peer (P2P) technology has already been established in several application domains, e.g., IP telephony, file sharing, and content distribution. It is considered to be distributed, ad-hoc, robust and scalable approach for digital information transfer. In this thesis, the P2P communication paradigm is proposed as an alternative communication approach in the first response application domai...

We address the problem of integrating real-time fault-tolerance mechanisms into peer-to-peer systems, with specific architecture and deployment constraints. For this purpose we implemented a prototype hierarchical peer-to-peer framework in which the leaf peers are sensors that generate different kinds of traffic such as mesh management, events, video and audio. We evaluate the framework by meas...

Peer response is useful to improve student writing. However, traditional peer response takes a single mode, which has some problems, such as effort for preparation of documents or ambiguous feedback. To address these problems, this study presents two peer response approaches, that is, an integrative approach and a game-based integrative approach. Additionally, whether students with these two pe...

Heightened emotional reactivity to peer feedback is predictive of adolescents' depression risk. Examining variation in emotional reactivity within currently depressed adolescents may identify subgroups that struggle the most with these daily interactions. We tested whether trait rumination, which amplifies emotional reactions, explained variance in depressed adolescents' physiological reactivit...

among structured peer-to-peer systems, chord has a general popularity due to its salient features like simplicity, high scalability, small path length with respect to network size, and flexibility on node join and departure. however, chord doesn’t take into account the topology of underlying physical network when a new node is being added to the system, thus resulting in high routing latency an...

abstract— peer-to-peer ( p2p ) systems have been the center of attention in recent years due to their advantage . since each node in such networks can act both as a service provider and as a client , they are subject to different attacks . therefore it is vital to manage confidence for these vulnerable environments in order to eliminate unsafe peers . this paper investigates the use of genetic ...

The efficiency of a Peer-to-Peer file sharing overlay is measured in terms of the scalability and versatility of its object lookup strategy. In these networks peers carry out distributed query relaying to discover the service providers. Existing lookup mechanisms like flooding and random walks in unstructured P2P overlays create huge communication overhead and increased response time. In this w...