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SDN simplifies network management by relying on declarativity (high-level interface) and expressiveness (network flexibility). We propose a solution to support those features while preserving high robustness and scalability as needed in carrier-grade networks. Our solution is based on (i) a two-layer architecture separating connectivity and optimization(More)
This paper considers the daily assignment of newborn infant patients to nurses in a hospital. The objective is to balance the workload of the nurses, while satisfying a variety of side constraints. Prior work proposed a MIP model for this problem, which unfortunately did not scale to large instances and only approximated the objective function, since(More)
Many assignment problems require the solution to be balanced. Such a problem is the Balanced Academic Curriculum Problem (BACP) [1]. Standard deviation is a common way to measure the balance of a set of values. A recent constraint presented by Pesant and Régin [2] enforces the mean µ and the standard deviation σ of a set of variables. Our work extends [2](More)
The Steel Mill Slab Problem is an optimization benchmark that has been studied for a long time in the constraint-programming community but was only solved efficiently in the two last years. Gargani and Refalo solved the problem using Large Neighborhood Search and Van Henten-ryck and Michel made use of constraint programming with an improved symmetry(More)
The Balanced Academic Curriculum Problem (BACP) has received little attention in Constraint Programming. Only a few articles deals with this problem with experimental results on the three small instances publicly available in CSPLIB. The present article describes an approach to efficiently solve this challenging problem. Optimal solutions are produced on a(More)
The Large Neighborhood Search (LNS) approach for solving Constrained Optimization Problems has been proved to be effective on a wide range of problems. LNS is a local search metaheuristic that uses a complete search method (such as CP) to explore a large neighborhood. At each step, the neighborhood is defined by relaxing a subset, called fragment, of the(More)