Basilis Mamalis

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A large class of Wireless Sensor Networks (WSN) applications involve a set of isolated urban areas (e.g., urban parks or building blocks) covered by sensor nodes (SNs) monitoring environmental parameters. Mobile sinks (MSs) mounted upon urban vehicles with fixed trajectories (e.g., buses) provide the ideal infrastructure to effectively retrieve sensory data(More)
Clustering is a promising approach for building hierarchies and simplifying the routing process in mobile ad-hoc network environments. The main objective of clustering is to identify suitable node representatives, i.e. cluster heads (CHs), to store routing and topology information and maximize clusters stability. Traditional clustering algorithms suggest CH(More)
This paperl discusses the efi-iciency of a parallel text retrieval system that is based on the Vector Space Model. Specifically, we describe a general parallel retrieval algorithm for use with this model, the application of the algorithm in the FIRE system [I], and its implementation on the high performance GCe131512 Parsytec parallel machine [2]. The use(More)
Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering algorithm that uses both location(More)
Mobile ad hoc networks comprise a collection of wireless nodes that dynamically create a network among themselves without using any pre-existing infrastructure. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to answer the organization, scalability and routing problems of mobile ad hoc networks. In this work, we(More)
The main objective of clustering in mobile ad-hoc network environments is to identify suitable node representatives, i.e. cluster heads (CHs) to store routing and topology information; CHs should be elected so as to maximize clusters stability, that is to prevent frequent cluster re-structuring. A popular clustering algorithm (LID) suggests CH election(More)
A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile nodes forming a network without using any existing infrastructure. All mobile nodes function as mobile routers that discover and maintain routes to other mobile nodes of the network and therefore, can be connected dynamically in an arbitrary manner. The mobility attribute of MANETs is a very(More)
Lately, many systems and websites add personalization functionalities among their provided services. However, for large document collections it is difficult for the user to direct effective queries from the beginning of his/her search, since accurate query terms may not be known in advance. In this paper we describe a system that applies a hybrid approach(More)