Serafino Cicerone

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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)
We propose a fully-dynamic distributed algorithm for the all-pairs shortest paths problem on general networks with positive real edge weights. If ∆σ is the number of pairs of nodes changing the distance after a single edge modification σ (insert, delete, weight decrease, or weight increase) then the message complexity of the proposed algorithm is O(n∆σ) in(More)
Parity graphs form a superclass of bipartite and distance-hereditary graphs. Since their introduction, all the algorithms proposed as solutions to the recognition problem and other combinatorial problems exploit the structural property of these graphs described by Burlet and Uhry in [8]. This paper introduces a different structural property of parity(More)
In this paper we propose a uniform approach to deal with incremental problems on digraphs and with decremental problems on dags generalizing a technique used by La Poutré and van Leeuwen in [17] for updating the transitive closure and the transitive reduction of a dag. We define a propagation property on a binary relationship over the vertices of a digraph(More)
Several attempts have been done in the literature in the last years in order to provide a formal definition of the notions of robustness and recoverability for optimization problems. Recently, a new model of recoverable robustness has been introduced in the context of railways optimization. The basic idea of recoverable robustness is to compute solutions(More)