@inproceedings{KoehlerSkutella, author = {K{\"o}hler, Ekkehard and Skutella, Martin}, title = {Flows over time with load-dependent transit times}, series = {Proceeding SODA '02 Proceedings of the thirteenth annual ACM-SIAM symposium on Discrete algorithms}, booktitle = {Proceeding SODA '02 Proceedings of the thirteenth annual ACM-SIAM symposium on Discrete algorithms}, publisher = {ACM Press [u.a.]}, address = {New York [u.a.]}, isbn = {0-89871-513-X}, pages = {174 -- 183}, language = {en} } @inproceedings{MoehringKoehlerGawrilowetal., author = {M{\"o}hring, Rolf H. and K{\"o}hler, Ekkehard and Gawrilow, Ewgenij and Stenzel, Bj{\"o}rn}, title = {Conflict-free Real-time AGV Routing}, series = {Operations Research Proceedings 2004, Selected Papers of the Annual International Conference of the German Operations Research Society (GOR), Jointly Organized with the Netherlands Society for Operations Research (NGB) Tilburg, September 1-3, 2004}, booktitle = {Operations Research Proceedings 2004, Selected Papers of the Annual International Conference of the German Operations Research Society (GOR), Jointly Organized with the Netherlands Society for Operations Research (NGB) Tilburg, September 1-3, 2004}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-540-24274-1}, doi = {10.1007/3-540-27679-3_3}, pages = {18 -- 24}, language = {en} } @misc{KoehlerLiebchenWuenschetal., author = {K{\"o}hler, Ekkehard and Liebchen, Christian and W{\"u}nsch, Gregor and Rizzi, Romeo}, title = {Lower bounds for strictly fundamental cycle bases in grid graphs}, series = {Networks : an international journal}, volume = {53}, journal = {Networks : an international journal}, number = {2}, issn = {1097-0037}, doi = {10.1002/net.20283}, pages = {191 -- 205}, language = {en} } @misc{KoehlerMouatadid, author = {K{\"o}hler, Ekkehard and Mouatadid, Lalla}, title = {A linear time algorithm to compute a maximum weighted independent set on cocomparability graphs}, series = {Information Processing Letters}, volume = {116}, journal = {Information Processing Letters}, number = {6}, issn = {0020-0190}, doi = {10.1016/j.ipl.2015.12.001}, pages = {391 -- 395}, language = {en} } @misc{KoehlerStrehler, author = {K{\"o}hler, Ekkehard and Strehler, Martin}, title = {Traffic signal optimization: combining static and dynamic models}, series = {arXiv.org}, journal = {arXiv.org}, pages = {29}, abstract = {In this paper, we present a cyclically time-expanded network model for simultaneous optimization of traffic assignment and traffic signal parameters, in particular offsets, split times, and phase orders. Since travel times are of great importance for developing realistic solutions for traffic assignment and traffic signal coordination in urban road networks, we perform an extensive analysis of the model. We show that a linear time-expanded model can reproduce realistic travel times especially for use with traffic signals and we verify this by simulation. Furthermore, we show how exact mathematical programming techniques can be used for optimizing the control of traffic signals. We provide computational results for real world instances and demonstrate the capabilities of the cyclically time-expanded by simulation results obtained with state-of-the-art traffic simulation tools.}, language = {en} } @misc{SchnellenbachKoehler, author = {Schnellenbach, Jan and K{\"o}hler, Ekkehard}, title = {Zur{\"u}ck zum Rubikon: Wie der Primat der Politik in der Eurozone wieder dauerhaft hergestellt werden kann}, series = {Badische Zeitung}, journal = {Badische Zeitung}, number = {23.08.2012}, language = {de} } @misc{DraganKoehlerLeitert, author = {Dragan, Feodor F. and K{\"o}hler, Ekkehard and Leitert, Arne}, title = {Line-distortion, Bandwidth and Path-length of a graph}, series = {Algorithmica}, volume = {77}, journal = {Algorithmica}, number = {3}, issn = {0178-4617}, doi = {10.1007/s00453-015-0094-7}, pages = {686 -- 713}, language = {en} } @inproceedings{DraganKoehlerAlrasheed, author = {Dragan, Feodor F. and K{\"o}hler, Ekkehard and Alrasheed, Hend}, title = {Eccentricity Approximating Trees}, series = {Graph-Theoretic Concepts in Computer Science, 42nd International Workshop, WG 2016, Istanbul, Turkey, June 22-24, 2016}, booktitle = {Graph-Theoretic Concepts in Computer Science, 42nd International Workshop, WG 2016, Istanbul, Turkey, June 22-24, 2016}, editor = {Heggernes, Pinar}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-662-53536-3}, doi = {10.1007/978-3-662-53536-3_13}, pages = {145 -- 157}, language = {en} } @incollection{Koehler, author = {K{\"o}hler, Ekkehard}, title = {Linear Structure of Graphs and the Knotting Graph}, series = {Gems of Combinatorial Optimization and Graph Algorithms}, booktitle = {Gems of Combinatorial Optimization and Graph Algorithms}, publisher = {Springer International Publishing}, address = {Cham [u.a.]}, isbn = {978-3-319-24971-1}, doi = {10.1007/978-3-319-24971-1_2}, pages = {13 -- 27}, language = {en} } @misc{DraganKoehlerAlrasheed, author = {Dragan, Feodor F. and K{\"o}hler, Ekkehard and Alrasheed, Hend}, title = {Eccentricity approximating trees}, series = {Discrete Applied Mathematics}, volume = {232}, journal = {Discrete Applied Mathematics}, issn = {0166-218X}, doi = {10.1016/j.dam.2017.07.017}, pages = {142 -- 156}, language = {en} } @inproceedings{SchefflerMansouriYarahmadiBreussetal., author = {Scheffler, Robert and Mansouri Yarahmadi, Ashkan and Breuß, Michael and K{\"o}hler, Ekkehard}, title = {A Graph Theoretic Approach for Shape from Shading}, series = {Energy minimization methods in computer vision and pattern recognition , 11th International Conference, EMMCVPR 2017, Venice, Italy, October 30 - November 1, 2017}, booktitle = {Energy minimization methods in computer vision and pattern recognition , 11th International Conference, EMMCVPR 2017, Venice, Italy, October 30 - November 1, 2017}, editor = {Pelillo, Marcello and Hancock, Edwin}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-78198-3}, doi = {10.1007/978-3-319-78199-0_22}, pages = {328 -- 341}, abstract = {Resolving ambiguities is a fundamental problem in shape from shading (SFS). The classic SFS approach allows to reconstruct the surface locally around singular points up to an ambiguity of convex, concave or saddle point type. In this paper we follow a recent approach that seeks to resolve the local ambiguities in a global graph-based setting so that the complete surface reconstruction is consistent. To this end, we introduce a novel graph theoretic formulation for the underlying problem that allows to prove for the first time in the literature that the underlying surface orientation problem is NP-complete. Moreover, we show that our novel framework allows to define an algorithmic framework that solves the disambiguation problem. It makes use of cycle bases for dealing with the graph construction and enables an easy embedding into an optimization method that amounts here to a linear program.}, language = {en} } @misc{BeisegelDenkertKoehleretal., author = {Beisegel, Jesse and Denkert, Carolin and K{\"o}hler, Ekkehard and Krnc, Matjaž and Pivač, Nevena and Scheffler, Robert and Strehler, Martin}, title = {Recognizing Graph Search Trees}, series = {arXiv.org}, journal = {arXiv.org}, pages = {23}, language = {en} } @misc{BeisegelDenkertKoehleretal., author = {Beisegel, Jesse and Denkert, Carolin and K{\"o}hler, Ekkehard and Krnc, Matjaž and Pivač, Nevena and Scheffler, Robert and Strehler, Martin}, title = {On the End-Vertex Problem of Graph Searches}, series = {Discrete Mathematics \& Theoretical Computer Science}, volume = {21}, journal = {Discrete Mathematics \& Theoretical Computer Science}, number = {1}, issn = {1365-8050}, language = {en} } @misc{BeisegelChiarelliKoehleretal., author = {Beisegel, Jesse and Chiarelli, Nina and K{\"o}hler, Ekkehard and Krnc, Matjaž and Milanič, Martin and Pivač, Nevena and Scheffler, Robert and Strehler, Martin}, title = {Edge Elimination and Weighted Graph Classes}, series = {Graph-Theoretic Concepts in Computer Science - 46th International Workshop, {WG} 2020, Leeds, UK, June 24-26, 2020}, journal = {Graph-Theoretic Concepts in Computer Science - 46th International Workshop, {WG} 2020, Leeds, UK, June 24-26, 2020}, editor = {Adler, Isolde and M{\"u}ller, Haiko}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-60439-4}, issn = {1611-3349}, doi = {10.1007/978-3-030-60440-0_11}, pages = {134 -- 147}, language = {en} } @misc{BeisegelKoehlerScheffleretal., author = {Beisegel, Jesse and K{\"o}hler, Ekkehard and Scheffler, Robert and Strehler, Martin}, title = {Linear Time LexDFS on Chordal Graphs}, series = {28th Annual European Symposium on Algorithms (ESA) 2020, September 7-9, 2020, Pisa, Italy)}, volume = {173}, journal = {28th Annual European Symposium on Algorithms (ESA) 2020, September 7-9, 2020, Pisa, Italy)}, publisher = {Schloss Dagstuhl, Leibnitz Zentrum f{\"u}r Informatik}, doi = {10.4230/LIPIcs.ESA.2020.13}, url = {http://nbn-resolving.de/urn:nbn:de:0030-drops-128790}, pages = {13:1 -- 13:13}, language = {en} } @misc{BeisegelDenkertKoehleretal., author = {Beisegel, Jesse and Denkert, Carolin and K{\"o}hler, Ekkehard and Krnc, Matjaž and Pivač, Nevena and Scheffler, Robert and Strehler, Martin}, title = {Recognizing Graph Search Trees}, series = {The proceedings of Lagos 2019, the tenth Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS 2019) 2-7 June 2019, Belo Horizonte, Brazil}, journal = {The proceedings of Lagos 2019, the tenth Latin and American Algorithms, Graphs and Optimization Symposium (LAGOS 2019) 2-7 June 2019, Belo Horizonte, Brazil}, editor = {Coutinho, Gabriel and Kohayakawa, Yoshiharu and dos Santos, Vinicius and Urrutia, Sebasti{\´a}n}, publisher = {Elsevier}, issn = {1571-0661}, doi = {10.1016/j.entcs.2019.08.010}, pages = {99 -- 110}, language = {en} } @misc{KoehlerStrehler, author = {K{\"o}hler, Ekkehard and Strehler, Martin}, title = {Traffic Signal Optimization: Combining Static and Dynamic Models}, series = {Transportation Science}, volume = {53}, journal = {Transportation Science}, number = {1}, issn = {1526-5447}, doi = {10.1287/trsc.2017.0760}, pages = {21 -- 41}, language = {en} } @misc{BeisegelDenkertKoehleretal., author = {Beisegel, Jesse and Denkert, Carolin and K{\"o}hler, Ekkehard and Krnc, Matjaž and Pivač, Nevena and Scheffler, Robert and Strehler, Martin}, title = {The Recognition Problem of Graph Search Trees}, series = {SIAM Journal on Discrete Mathematics}, volume = {35}, journal = {SIAM Journal on Discrete Mathematics}, number = {2}, issn = {1095-7146}, doi = {10.1137/20M1313301}, pages = {1418 -- 1446}, language = {en} } @misc{HartmannKoehlerSchmidtetal., author = {Hartmann, Carsten and K{\"o}hler, Ekkehard and Schmidt, Heiko and Klein, Marten}, title = {Scientific computing LAB (SCL)}, series = {"Get Into Energy", BTU Cottbus-Senftenberg, ZHG Building, 1 Feb. 2023}, journal = {"Get Into Energy", BTU Cottbus-Senftenberg, ZHG Building, 1 Feb. 2023}, address = {Cottbus}, pages = {1}, abstract = {KEY COMPETENCE AND FOCUS • Development of numerical methods and algorithms for multi-energy systems • Multiscale and multiphysics modeling and simulation of P2X technologies • Stochastic simulation and efficient optimization of complex energy networks}, language = {en} } @misc{KoehlerRoggeScheffleretal., author = {K{\"o}hler, Ekkehard and Rogge, Markus and Scheffler, Robert and Strehler, Martin}, title = {Optimal Bicycle Routes with Few Signal Stops}, series = {23rd Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2023)}, volume = {OASIcs - Open Access Series in Informatics; Band 115}, journal = {23rd Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2023)}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl}, issn = {978-3-95977-302-7}, doi = {10.4230/OASIcs.ATMOS.2023.1}, pages = {1:1 -- 1:14}, language = {en} } @misc{BeisegelChiarelliKoehleretal., author = {Beisegel, Jesse and Chiarelli, Nina and K{\"o}hler, Ekkehard and Milanič, Martin and Muršič, Peter and Scheffler, Robert}, title = {The simultaneous interval number: a new width parameter that measures the similarity to interval graphs}, series = {19th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2024)}, journal = {19th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2024)}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl}, isbn = {978-3-95977-318-8}, doi = {10.4230/LIPIcs.SWAT.2024.7}, pages = {7:1 -- 7:20}, language = {en} } @misc{BeisegelKoehlerRatajczaketal., author = {Beisegel, Jesse and K{\"o}hler, Ekkehard and Ratajczak, Fabienne and Scheffler, Robert and Strehler, Martin}, title = {Graph search trees and the intermezzo problem}, series = {49th International Symposium on Mathematical Foundations of Computer Science (MFCS 2024)}, journal = {49th International Symposium on Mathematical Foundations of Computer Science (MFCS 2024)}, editor = {Kr{\´a}lovič, Rastislav and Kučera, Anton{\´i}n}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl}, isbn = {978-3-95977-335-5}, doi = {10.4230/LIPICS.MFCS.2024.22}, pages = {22:1 -- 22:18}, language = {en} } @misc{BeisegelKoehlerScheffleretal., author = {Beisegel, Jesse and K{\"o}hler, Ekkehard and Scheffler, Robert and Strehler, Martin}, title = {Certifying fully dynamic algorithms for recognition and Hamiltonicity of Threshold and Chain Graphs}, series = {Algorithmica}, volume = {85}, journal = {Algorithmica}, number = {8}, issn = {0178-4617}, doi = {10.1007/s00453-023-01107-1}, pages = {2454 -- 2481}, language = {en} }