TECHNICAL SESSIONS Monday, 8:00-9:30 MA-02 Monday, 8:00-9:30 MA-01 Room SB 227 Monday, 8:00-9:30 Combinatorial Optimisation Hall A Stream: Combinatorial Optimisation (c) Effective Algorithms for Combinatorial Contributed session Optimisation Problems Chair: Ioannis Mourtos, Department of Economics, University Stream: Combinatorial Optimisation (dedicated to of Patras, Rion, 26 504, Patras, Greece,
[email protected] the memory of Peter L. Hammer) 1 - On the Representability of Totally Unimodular Ma- Invited session trices on Bidirected Graphs Chair: Paolo Toth, Deis, University of Bologna, Viale Leonidas Pitsoulis, Mathematical and Physical Sciences, Risorgimento 2, 40136, Bologna, Italy,
[email protected] Aristotle University of Thessaloniki, Engineering School, 1 - A Branch-and-Cut-and-Price approach for the Train Department of Mathematical and Physical Sciences, 54124, Thessaloniki,
[email protected], Gautam Appa, Platforming Problem Konstantinos Papalamprou, Balazs Kotnyek Laura Galli, DEIS, University of Bologna, Viale Its well known that any totally unimodular (TU) matrix can be con- Risorgimento, 2, 40136, Bologna,
[email protected], structed through a series of operations called k-sums starting from net- Paolo Toth, Alberto Caprara work matrices their transposes and two unique representation matrices We present an ILP model and an exact algorithm for a Train Platforming B1 and B2 of a certain matroid. Given that B1, B2 are binet we examine Problem arising in real life applications. The goal is to assign to each train the k-sums of network and binet matrices. It is shown that binet matrices a platform and two paths, avoiding platform-conflicts, keeping the num- are not closed under k-sums.