@inproceedings{HildenbrandtReineltHeismann, author = {Hildenbrandt, Achim and Reinelt, Gerhard and Heismann, Olga}, title = {Integer Programming Models for the Target Visitation Problem}, series = {Proceedings of the 16th International Multiconference INFORMATION SOCIETY - IS 2013}, booktitle = {Proceedings of the 16th International Multiconference INFORMATION SOCIETY - IS 2013}, pages = {569 -- 572}, abstract = {The target visitation problem (TVP) is concerned with finding a route to visit a set of targets starting from and returning to some base. In addition to the distance traveled a tour is evaluated by taking also preferences into account which address the sequence in which the targets are visited. The problem thus is a combination of two well-known combinato- rial optimization problems: the traveling salesman and the linear ordering problem. In this paper we present several possible IP-Models for this problem and compared them to their usability for branch-and-cut approaches.}, language = {en} } @misc{HeismannHildenbrandtSilvestrietal., author = {Heismann, Olga and Hildenbrandt, Achim and Silvestri, Francesco and Reinelt, Gerhard and Bornd{\"o}rfer, Ralf}, title = {HUHFA: A Framework for Facet Classification}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-42230}, abstract = {Usually complete linear descriptions of polytopes consist of an enormous number of facet-defining inequalities already for very small problem sizes. In this paper, we describe a method for dividing the inequalities into equivalence classes without resorting to a normal form. Within each class, facets are related by certain symmetries and it is sufficient to list one representative of each class to give a complete picture of the structural properties of a polytope. We propose an algorithm for the classification and illustrate its efficiency on a broad range of combinatorial optimization problems including the Traveling Salesman and the Linear Ordering Problem.}, language = {en} }