Igor Crévits

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Recently several hybrid methods combining exact algorithms and heuristics have been proposed for solving hard combinatorial optimization problems. In this paper, we propose new iterative relaxation-based heuristics for the 0–1 Mixed Integer Programming problem (0–1 MIP), which generate a sequence of lower and upper bounds. The upper bounds are obtained from(More)
In this paper we propose new hybrid methods for solving the multidimensional knapsack problem. They can be viewed as matheuristics that combine mathematical programming with the variable neighbourhood decomposition search heuristic. In each iteration a relaxation of the problem is solved to guide the generation of the neighbourhoods. Then the problem is(More)
The increasing air traffic and the ensuing increasing burden on air traffic controllers suggest to attempt to provide enhanced assistance to air traffic controllers. As it is difficult to reduce the number of primary tasks, a solution is to give active assistance to controllers by means of computer tools that allow for optimal control in order to maintain(More)
In the current organisation of air traffic control, some cooperative activities appear in the work of air traffic controllers, especially between Tactical Controllers (TC) and Planning Controllers (PC), who manage aircraft inside a sector to prevent collisions. These cooperative activities allow building and maintaining a Common Frame of References (COFOR)(More)