General networks such as Internet are complex heterogeneous networks, which are constructed by many different organizations, and so become non-effective ones. Therefore one constructed a level of software over networks which is called overlay or virtual topology. In this paper we present principle of symmetry for general network topology by using Cayley graph models and show its necessity to im...

—Project JXTA is the first peer-to-peer application development infrastructure that includes standard protocols and multi-language implementations. Performance and scalability of JXTA are not well understood, despite its widespread usage in research and increasing popularity in the industry. This paper reports on a performance evaluation of the JXTA protocol implementations in Java. The peer st...

In this paper, we propose managing data summaries in unstructured P2P systems. Our summaries are intelligible views with two main virtues. First, they can be directly queried and used to approximately answer a query. Second, as semantic indexes, they support locating relevant nodes based on data content. The performance evaluation of our proposal shows that the cost of query routing is minimize...

Many peer-to-peer systems require a way of accurately assessing the bandwidth of their constituent peers. However, nodes cannot be trusted to accurately report their own capacity in the presence of incentives to the contrary and thus self-reporting can lead to poor network performance and security flaws. We present EigenSpeed, a secure and accurate peer-to-peer bandwidth evaluation system based...

The size of a Peer-to-Peer (P2P) network is an important parameter for performance tuning of P2P routing algorithms. This paper introduces and evaluates a new efficient method for participants in an unstructured P2P network to establish the size of the overall network. The presented method is highly efficient, propagating information about the current size of the network to all participants usi...

Storage capacity, like computing power, follows its Moore’s law and grows dramatically. Consequently, the need for data backup services increases. The domain of data backup was recently hit by the peer-to-peer wave: several projects propose to use a cooperative approach to the backup problem. In this paper we survey these projects, the various problems they face and the techniques they propose ...

BitTorrent is undoubtedly the most popular P2P file sharing application on today’s Internet. The widespread popularity of BitTorrent has attracted a great deal of attention from networking researchers who conducted various performance studies on it. This paper presents a comprehensive survey of analytical performance modeling techniques for BitTorrent networks. The performance models examined i...

Two forms of thinking about the future are distinguished: expectations versus fantasies. Positive expectations (judging a desired future as likely) predicted high effort and successful performance, but the reverse was true for positive fantasies (experiencing one's thoughts and mental images about a desired future positively). Participants were graduates looking for a job (Study 1), students wi...

This article explains the pilot project and results of a peer review which, according to the data available, is the first such review carried out in the Croatian nursing practice. The goals of this project were to identify standards of professional performance which describe behaviour of competent professionals. Peer review is the evaluation of an individual’s professional performance for relev...