Browsing by Subject "Peer-to-peer architecture (Computer networks)"

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Open Access
Data dissemination strategies for mobile peer-to-peer information systems with applications to healthcare
(2009) Özbekoğlu, Fatih Melih
Peer-to-peer (P2P) architecture is becoming increasingly popular for various applications, replacing the classical Client-Server architecture. With the enhanced capabilities of mobile devices (PDAs, mobile phones, etc.) wireless networks started to take advantage of P2P paradigm along with its properties like infrastructure-free operation, scalability, balanced and distributed workload. Mobile peer-to-peer (MP2P) networks refer to the application of P2P architecture over wireless networks. Problems about dissemination of data in both P2P and MP2P networks are widely studied, and there are many proposed solutions. Healthcare information systems are helping clinicians to hold the information belonging to patients and diseases, and to communicate with each other since early 1950s. Today, they are widely used in hospitals, being constructed using Client-Server network architecture. Wireless technologies are also applied to medical domain, especially for monitoring purposes. In this thesis, we present and evaluate various data dissemination strategies to work on a mobile peer-to-peer (MP2P) network designed for a medical healthcare environment. First, the designed network system is presented along with the network topology. Then, the proposed data dissemination strategies are described. And finally, these strategies are evaluated according to the properties and needs of a medical system.
Open Access
Top-K link recommendation for development of P2P social networks
(2014) Aytaş, Yusuf
The common approach for implementing social networks has been using centralized infrastructures, which inherently include problems of privacy, censorship, scalability, and fault-tolerance. Although decentralized systems offer a natural solution, significant research is needed to build an end-to-end peer-to-peer social network where data is stored among trusted users. The centralized algorithms need to be revisited for a P2P setting, where the nodes have connectivity to only neighbors, have no information of global topology, and may go offline and churn resulting in changes of the graph structure. The social graph algorithms should be designed as robust to node failures and network changes. We model P2P social networks as uncertain graphs where each node can go offline, and we introduce link recommendation algorithms that support the development of decentralized social networks. We propose methods to recommend top-k links to improve the underlying topology and efficiency of the overlay network, while preserving the locality of the social structure. Our approach aims to optimize the probabilistic reachability, improve the robustness of the local network and avoid loss from failures of the peers. We model the problem through discrete optimization and assign a score to each node to capture both the topological connectivity and the social centrality of the corresponding node. We evaluate the proposed methods with respect to performance and quality measures developed for P2P social networks.