Biblio

Trust plays an important role in human life environments and virtual organizations. In the context of a network, trust may help its elements to decide whether another member of the same network is being uncooperative or malicious. Trust becomes quite important in self-configurable and autonomous systems, such as wireless sensor networks (WSN). However, very little effort has been done in the field of trust management in WSN. On the other hand, some efforts have been made in quite related fields such as Ad-hoc and P2P networks. In this paper we give an overview of existing trust management solutions, mainly those developed for Ad-Hoc and P2P networks and, more importantly, investigate their suitability to WSN. We also provide some guidelines to aid the development of trust management systems for WSN according to the nature of these networks.

Clausal temporal resolution is characterised by a translation of the formulae whose satisfiability is to be established to a normal form, step resolution (similar to classical resolution) on formulae occurring at the same states and temporal resolution between formulae describing properties over a longer period. The most complex part of the method occurs in searching for candidates for the temporal resolution operation, something that may need to be carried out several times. In this paper we consider a new technique for finding the candidates for the temporal resolution operation. Although related to the previously developed external search procedure, this new approach not only allows the temporal resolution operation to be carried out at any moment, but also simplifies any subsequent search required for similar temporal formulae. Finally, in contrast with previous approaches, this search can be seen as an inherent part of the resolution process, rather than an external procedure that is only called in certain situations.} year = {2002