Alfredo Navarra

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SYNTHESIS is a tool for automatically assembling correct and distributed component-based systems. In our context, a system is correct when it is deadlock-free and performs only specified component interactions. In order to automatically synthesize the correct composition code, SYNTHESIS takes as input an high-level behavioural description for each component(More)
In this paper we present a new heuristic called Adaptive Broadcast Consumption (ABC for short) for the Minimum-Energy Broadcast Routing (MEBR) problem. We first investigate the problem trying to understand which are the main properties not taken into account by the classic and well–studied MST and BIP heuristics, then we propose a new algorithm proving that(More)
In this paper we present a new upper bound on the approximation ratio of the minimum spanning tree heuristic for the basic problem on ad-hoc networks given by the minimum-energy broadcast routing (MEBR) problem. We introduce a new analysis allowing to establish a 6.33-approximation ratio in the 2-dimensional case, thus decreasing the previously known 7.6(More)
We consider the problem of determining constructions with an asymptotically optimal oblivious diameter in small world graphs under the Kleinberg’s model. In particular, we give the first general lower bound holding for any monotone distance distribution, that is induced by a monotone generating function. Namely, we prove that the expected oblivious diameter(More)
In this paper we present new results on the performance of the Minimum Spanning Tree heuristic for the <i>Minimum-Energy Broadcast Routing</i> (MEBR) problem. We first prove that, for any number of dimensions <i>d</i> &#8805; 2, the approximation ratio of the heuristic does not increase when the power attenuation coefficient &#945;, that is the exponent to(More)
In this paper we provide efficient robust algorithms for shunting problems concerning the reordering of train cars over a hump. In particular, we study algorithms able to cope with small disruptions, as temporary and local unavailability and/or malfunctioning of key resources that can occur and affect planned operations. To this aim, a definition of robust(More)
Distributed Greedy Coloring is an interesting and intuitive variation of the standard Coloring problem. Given an order among the colors, a coloring is said to be greedy if there does not exist a vertex for which its associated color can be replaced by a color of lower position in the fixed order without violating the property that neighbouring vertices must(More)
Prolonging the lifetime of wireless sensor networks has always been a determining factor when designing and deploying such networks. Clustering is one technique that can be used to extend the lifetime of sensor networks by grouping sensors together. However, there exists the hot spot problem which causes an unbalanced energy consumption in equally formed(More)