Massimo Marchiori

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We introduce the concept of efficiency of a network as a measure of how efficiently it exchanges information. By using this simple measure, small-world networks are seen as systems that are both globally and locally efficient. This gives a clear physical meaning to the concept of "small world," and also a precise quantitative analysis of both weighted and(More)
Conditional rewriting is universally recognized as being much more complicated than unconditional rewriting In this paper we study how much of conditional rewriting can be automatically inferred from the simpler theory of unconditional rewriting We introduce a new tool called unraveling to automatically translate a conditional term rewriting system CTRS(More)
Large but rare cascades triggered by small initial shocks are present in most of the infrastructure networks. Here we present a simple model for cascading failures based on the dynamical redistribution of the flow on the network. We show that the breakdown of a single node is sufficient to collapse the efficiency of the entire system if the node is among(More)
Community structures are an important feature of many social, biological, and technological networks. Here we study a variation on the method for detecting such communities proposed by Girvan and Newman and based on the idea of using centrality measures to define the community boundaries [M. Girvan and M. E. J. Newman, Proc. Natl. Acad. Sci. U.S.A. 99, 7821(More)
The concept of network efficiency, recently proposed to characterize the properties of small-world networks, is here used to study the effects of errors and attacks on scale-free networks. Two different kinds of scale-free networks, i.e. networks with power law P(k), are considered: 1) scale-free networks with no local clustering produced by the(More)
A new method, based on a recently defined centrality measure, allows to spot the critical components of a generic complex network. The identification and protection of the critical components of a given communication–transportation network should be the first concern in order to reduce the consequences of terrorist attacks. On the other hand, the critical(More)
The Resource Description Framework (RDF) Model&Syntax Specification describes a metadata infrastructure which can accommodate classification elements from different vocabularies i.e. schemas. The underlying model consists of a labeled directed acyclic graph which can be linearized into eXtensible Markup Language (XML) transfer syntax for interchange between(More)