@article{RaackKosterOrlowskietal.2011, author = {Raack, Christian and Koster, Arie M.C.A. and Orlowski, Sebastian and Wess{\"a}ly, Roland}, title = {On cut-based inequalities for capacitated network design polyhedra}, volume = {57}, journal = {Networks}, number = {2}, pages = {141 -- 156}, year = {2011}, language = {en} } @article{IdzikowskiOrlowskiRaacketal.2011, author = {Idzikowski, Filip and Orlowski, Sebastian and Raack, Christian and Woesner, Hagen and Wolisz, Adam}, title = {Dynamic routing at different layers in IP-over-WDM networks - Maximizing energy savings}, journal = {Optical Switching and Networking, Special Issue on Green Communications}, year = {2011}, language = {en} } @article{RaackRaymondSchlechteetal.2013, author = {Raack, Christian and Raymond, Annie and Schlechte, Thomas and Werner, Axel}, title = {Standings in sports competitions using integer programming}, volume = {10}, journal = {Journal of Quantitative Analysis in Sports}, number = {2}, publisher = {De Gruyter}, doi = {10.1515/jqas-2013-0111}, pages = {131 -- 137}, year = {2013}, language = {en} } @article{GroetschelRaackWerner2013, author = {Gr{\"o}tschel, Martin and Raack, Christian and Werner, Axel}, title = {Towards optimizing the deployment of optical access networks}, volume = {2}, journal = {EURO Journal on Computational Optimization}, publisher = {Springer}, doi = {10.1007/s13675-013-0016-x}, pages = {17 -- 53}, year = {2013}, language = {en} } @article{BetkerKosiankowskiLangeetal.2014, author = {Betker, Andreas and Kosiankowski, Dirk and Lange, Christoph and Pfeuffer, Frank and Raack, Christian and Werner, Axel}, title = {Energy efficiency in extensive IP-over-WDM networks with protection}, journal = {Operations Research Proceedings 2012}, editor = {Helber, Stefan and Breitner, Michael and R{\"o}sch, Daniel and Sch{\"o}n, Cornelia and Graf von der Schulenburg, Johann-Matthias and Sibbertsen, Philipp and Steinbach, Marc and Weber, Stefan and Wolter, Anja}, publisher = {Springer}, doi = {10.1007/978-3-319-00795-3_14}, pages = {93 -- 99}, year = {2014}, language = {en} } @article{PossRaack2013, author = {Poss, Michael and Raack, Christian}, title = {Affine recourse for the robust network design problem: Between static and dynamic routing}, volume = {61}, journal = {Networks - Special Issue: INOC 2011 Conference, June 13-16, 2011, Hamburg, Germany}, number = {2}, doi = {10.1002/net.21482}, pages = {180 -- 198}, year = {2013}, abstract = {Affinely-Adjustable Robust Counterparts provide tractable alternatives to (two-stage) robust programs with arbitrary recourse. We apply them to robust network design with polyhedral demand uncertainty, introducing the affine routing principle. We compare the affine routing to the well-studied static and dynamic routing schemes for robust network design. All three schemes are embedded into the general framework of two-stage network design with recourse. It is shown that affine routing can be seen as a generalization of the widely used static routing still being tractable and providing cheaper solutions. We investigate properties on the demand polytope under which affine routings reduce to static routings and also develop conditions on the uncertainty set leading to dynamic routings being affine. We show however that affine routings suffer from the drawback that (even totally) dominated demand vectors are not necessarily supported by affine solutions. Uncertainty sets have to be designed accordingly. Finally, we present computational results on networks from SNDlib. We conclude that for these instances the optimal solutions based on affine routings tend to be as cheap as optimal network designs for dynamic routings. In this respect the affine routing principle can be used to approximate the cost for two-stage solutions with free recourse which are hard to compute.}, language = {en} } @article{AchterbergRaack2010, author = {Achterberg, Tobias and Raack, Christian}, title = {The MCF-Separator - Detecting and Exploiting Multi-Commodity Flows in MIPs}, journal = {Mathematical Programming C}, number = {2}, pages = {125 -- 165}, year = {2010}, language = {en} } @article{DashGuenluekRaack2011, author = {Dash, Sanjeeb and G{\"u}nl{\"u}k, Oktay and Raack, Christian}, title = {A note on the MIR closure and basic relaxations of polyhedra}, volume = {39}, journal = {Optimization Research Letters}, number = {3}, pages = {198 -- 199}, year = {2011}, language = {en} }