We study different extended formulations for the set X = {x E Zn | Ax = Ax0} in order to tackle the feasibility problem for the set X+ = X N Zn+. Here the goal is not to find an improved polyhedral relaxation of conv(X+), but rather to reformulate in such a way that the new variables introduced...

We consider both branch-and-cut and column generation approaches for the problem of finding a minimum cost assignment of jobs with release dates and deadlines to unrelated parallel machines. Results are presented for several variants both with and without Constraint Programming. Among the...