TY - JOUR A1 - Raack, Christian A1 - Koster, Arie M.C.A. A1 - Orlowski, Sebastian A1 - Wessäly, Roland T1 - On cut-based inequalities for capacitated network design polyhedra JF - Networks Y1 - 2011 UR - http://onlinelibrary.wiley.com/doi/10.1002/net.20395/abstract VL - 57 IS - 2 SP - 141 EP - 156 ER - TY - JOUR A1 - Idzikowski, Filip A1 - Orlowski, Sebastian A1 - Raack, Christian A1 - Woesner, Hagen A1 - Wolisz, Adam T1 - Dynamic routing at different layers in IP-over-WDM networks – Maximizing energy savings JF - Optical Switching and Networking, Special Issue on Green Communications Y1 - 2011 UR - http://opus.kobv.de/zib/volltexte/2010/1230/ ER - TY - JOUR A1 - Raack, Christian A1 - Raymond, Annie A1 - Schlechte, Thomas A1 - Werner, Axel T1 - Standings in sports competitions using integer programming JF - Journal of Quantitative Analysis in Sports Y1 - 2013 U6 - https://doi.org/10.1515/jqas-2013-0111 VL - 10 IS - 2 SP - 131 EP - 137 PB - De Gruyter ER - TY - JOUR A1 - Grötschel, Martin A1 - Raack, Christian A1 - Werner, Axel T1 - Towards optimizing the deployment of optical access networks JF - EURO Journal on Computational Optimization Y1 - 2013 U6 - https://doi.org/10.1007/s13675-013-0016-x VL - 2 SP - 17 EP - 53 PB - Springer ER - TY - JOUR A1 - Betker, Andreas A1 - Kosiankowski, Dirk A1 - Lange, Christoph A1 - Pfeuffer, Frank A1 - Raack, Christian A1 - Werner, Axel ED - Helber, Stefan ED - Breitner, Michael ED - Rösch, Daniel ED - Schön, Cornelia ED - Graf von der Schulenburg, Johann-Matthias ED - Sibbertsen, Philipp ED - Steinbach, Marc ED - Weber, Stefan ED - Wolter, Anja T1 - Energy efficiency in extensive IP-over-WDM networks with protection JF - Operations Research Proceedings 2012 Y1 - 2014 U6 - https://doi.org/10.1007/978-3-319-00795-3_14 SP - 93 EP - 99 PB - Springer ER - TY - JOUR A1 - Poss, Michael A1 - Raack, Christian T1 - Affine recourse for the robust network design problem: Between static and dynamic routing JF - Networks - Special Issue: INOC 2011 Conference, June 13–16, 2011, Hamburg, Germany N2 - 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. Y1 - 2013 U6 - https://doi.org/10.1002/net.21482 VL - 61 IS - 2 SP - 180 EP - 198 ER - TY - JOUR A1 - Achterberg, Tobias A1 - Raack, Christian T1 - The MCF-Separator – Detecting and Exploiting Multi-Commodity Flows in MIPs JF - Mathematical Programming C Y1 - 2010 UR - http://www.springerlink.com/content/383250gmx3184126/ IS - 2 SP - 125 EP - 165 ER - TY - JOUR A1 - Dash, Sanjeeb A1 - Günlük, Oktay A1 - Raack, Christian T1 - A note on the MIR closure and basic relaxations of polyhedra JF - Optimization Research Letters Y1 - 2011 UR - http://www.optimization-online.org/DB_HTML/2010/12/2853.html VL - 39 IS - 3 SP - 198 EP - 199 ER -