@misc{AchterbergKochMartin2004, author = {Achterberg, Tobias and Koch, Thorsten and Martin, Alexander}, title = {Branching rules revisited}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-7886}, number = {04-13}, year = {2004}, abstract = {Mixed integer programs are commonly solved with linear programming based branch-and-bound algorithms. The success of the algorithm strongly depends on the strategy used to select the variable to branch on. We present a new generalization called {\sl reliability branching} of today's state-of-the-art {\sl strong branching} and {\sl pseudocost branching} strategies for linear programming based branch-and-bound algorithms. After reviewing commonly used branching strategies and performing extensive computational studies we compare different parameter settings and show the superiority of our proposed newstrategy.}, language = {en} } @misc{EisenblaetterGeerdesKochetal.2004, author = {Eisenbl{\"a}tter, Andreas and Geerdes, Hans-Florian and Koch, Thorsten and Martin, Alexander and Wess{\"a}ly, Roland}, title = {UMTS Radio Network Evaluation and Optimization beyond Snapshots}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-7903}, number = {04-15}, year = {2004}, abstract = {This paper is concerned with UMTS radio network design. Our task is to reconfigure antennas and the related cells as to improve network quality. In contrast to second generation GSM networks, \emph{interference} plays a paramount role when designing third generation radio networks. A known compact formulation for assessing the interference characteristics of a radio network as coupling relations between cells based on user snapshots is generalized to statistical average load. This enables us to overcome the notorious difficulties of snapshot-based network optimization approaches. We recall a mixed-integer programming model for the network design problem that is based on user snapshots and contrast it with a new network design model based on the average coupling formulation. Exemplarily focusing on the important problem of optimizing antenna tilts, we give computational results for a fast local search algorithm and the application of a MIP solver to both models. These results demonstrate that our new average-based approaches outperform state-of-the-art snapshot models for UMTS radio network optimization.}, language = {en} } @misc{KochGriebelSoellneretal.2016, author = {Koch, Thorsten and Griebel, Rolf and S{\"o}llner, Konstanze and Christof, J{\"u}rgen and Bertelmann, Roland}, title = {DeepGreen - Entwicklung eines rechtssicheren Workflows zur effizienten Umsetzung der Open-Access-Komponente in den Allianz-Lizenzen f{\"u}r die Wissenschaft}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-56799}, pages = {22}, year = {2016}, abstract = {In Deutschland wurden 2011 wichtige Akzente f{\"u}r die Umsetzung des Gr{\"u}nen Wegs der Open-Access-Bewegung gesetzt: Mit finanzieller Unterst{\"u}tzung der Deutschen Forschungsgemeinschaft (DFG) haben Bibliotheken sogenannte Allianz-Lizenzen mit Verlagen verhandelt, in denen weitreichende Rechte hinsichtlich der Open-Access-Archivierung verankert sind. Autorinnen und Autoren zugriffsberechtigter Einrichtungen k{\"o}nnen ihre Artikel, die in diesen lizenzierten Zeitschriften erschienen sind, ohne oder mit nur kurzer Embargofrist in geeigneten Repositorien ihrer Wahl frei zug{\"a}nglich machen. Allerdings macht der Kreis berechtigter Autorinnen und Autoren nur sehr z{\"o}gerlich von seinen Open-Access-Rechten Gebrauch. Auch die Bibliotheken - als Betreiber der Repositorien und damit Vertreter f{\"u}r die berechtigten Autorinnen und Autoren - nutzen dieses Recht nur unzureichend. Mit DeepGreen verfolgen die Antragssteller das Ziel, einen Großteil jener Publikationen, die unter den speziell im DFG-gef{\"o}rderten Kontext verhandelten Bedingungen gr{\"u}n online gehen d{\"u}rften, auch tats{\"a}chlich online abrufbar zu machen. Im Rahmen des Projektes wird prototypisch mit Allianzverlagen und berechtigten Bibliotheken ein m{\"o}glichst stark automatisierter Workflow entwickelt, in dem rechtssichere Verlagsdaten inklusive der Volltexte abgeliefert und von Repositorien eingespielt werden. Ein technischer Baustein ist dabei ein intermedi{\"a}res Repositorium, das als Datenverteiler dient. Das nationale Projektkonsortium besteht aus den zwei Bibliotheksverb{\"u}nden Kooperativer Bibliotheksverbund Berlin-Brandenburg (KOBV) und Bibliotheksverbund Bayern (BVB), den zwei Universit{\"a}tsbibliotheken der Friedrich-Alexander-Universit{\"a}t Erlangen-N{\"u}rnberg (FAU) und der Technische Universit{\"a}t Berlin (TU Berlin), zus{\"a}tzlich die Bayerische Staatsbibliothek (BSB) und eine außeruniversit{\"a}re Forschungseinrichtung - das Helmholtz Open Science Koordinationsb{\"u}ro am Deutschen GeoForschungsZentrum (GFZ). Das Projekt startet zum 01. Januar 2016. Hier vorliegend finden Sie den Projektantrag zum Nachlesen.}, language = {de} } @misc{Koch2001, author = {Koch, Thorsten}, title = {ZIMPL User Guide}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-6466}, number = {01-20}, year = {2001}, abstract = {{\sc Zimpl} is a little language to translate the mathematical model of a problem into a linear or (mixed-)integer mathematical program expressed in {\tt lp} or {\tt mps} file format which can be read by a LP or MIP solver.}, language = {en} } @misc{BleyKoch2000, author = {Bley, Andreas and Koch, Thorsten}, title = {Optimierung in der Planung und beim Aufbau des G-WiN}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-6169}, number = {00-48}, year = {2000}, abstract = {Ende Juni diesen Jahres wurde das Gigabit-Wissenschaftsnetz offiziell gestartet. In der zweij{\"a}hrigen Vorbereitungsphase wurden nicht nur die technischen M{\"o}glichkeiten der neuen {\"U}bertragungstechniken und Dienste getestet. Es wurden auch verschiedene Fragestellungen zum effizienten Einsatz der verf{\"u}gbaren Ressourcen f{\"u}r den Betrieb des G-WiN untersucht. In diesem Artikel beschreiben wir, wie das G-WiN zu seiner jetzigen Struktur und Topologie gekommen ist.}, language = {de} } @misc{KaibelKoch2006, author = {Kaibel, Volker and Koch, Thorsten}, title = {Mathematik f{\"u}r den Volkssport}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-9225}, number = {06-28}, year = {2006}, abstract = {"`Volkssport Sudoku"' titelt der Stern in seiner Ausgabe vom 24. Mai2006. In der Tat traut sich derzeit kaum noch eine Zeitung, ohne Sudoku zu erscheinen. Die Begeisterung am L{\"o}sen dieser Zahlenr{\"a}tsel offenbart eine unvermutete Freude am algorithmischen Arbeiten. Mathematisch kann man Sudokus als lineare diophantische Gleichungssysteme mit Nichtnegativit{\"a}tsbedingungen formulieren. Solche ganzzahligen linearen Programme sind die wichtigsten Modellierungswerkzeuge in zahlreichen Anwendungsgebieten wie z.B. der Optimierung von Telekommunikations- und Verkehrsnetzen. Moderne Verfahren zur L{\"o}sung dieser Optimierungsprobleme sind durch Sudokus allerdings deutlich weniger zu beeindrucken als Zeitungsleser.}, language = {de} } @misc{AbboudGroetschelKoch2006, author = {Abboud, Nadine and Gr{\"o}tschel, Martin and Koch, Thorsten}, title = {Mathematical Methods for Physical Layout of Printed Circuit Boards: An Overview}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-9231}, number = {06-29}, year = {2006}, abstract = {This article surveys mathematical models and methods used for physical PCB layout, i.e., component placement and wire routing. The main concepts are briefly described together with relevant references.}, language = {en} } @misc{RuschPetersKottigBoltzeetal.2021, author = {Rusch, Beate and Peters-Kottig, Wolfgang and Boltze, Julia and Brandtner, Andreas and Degkwitz, Andreas and Kirsch, Simona and Koch, Thorsten and Lohrum, Stefan and M{\"u}ller, Anja and Mutter, Moritz and Seeliger, Frank and Stanek, Ursula}, title = {KOBV Jahresbericht 2019-2020}, address = {Berlin}, organization = {Kooperativer Bibliotheksverbund Berlin-Brandenburg}, issn = {1438-0064}, doi = {10.12752/8247}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-82474}, pages = {84}, year = {2021}, abstract = {Der aktuelle KOBV-Jahresbericht informiert dar{\"u}ber, was in den Mitgliedsbibliotheken und Partnerprojekten in den letzten beiden Jahren passiert ist und was sich in der Verbundzentrale und in der Bibliothekslandschaft {\"a}ndert. Die Ausgabe 2019/2020 enth{\"a}lt den Schwerpunktteil »Digitalisierung« mit verschiedenen Perspektiven auf die digitale Arbeitswelt.}, language = {de} } @misc{BertelmannKochCeynowaetal.2022, author = {Bertelmann, Roland and Koch, Thorsten and Ceynowa, Klaus and S{\"o}llner, Konstanze and Christof, J{\"u}rgen and Rusch, Beate and Sch{\"a}ffler, Hildegard and Putnings, Markus and Pampel, Heinz and Kuberek, Monika and Boltze, Julia and Lohrum, Stefan and Retter, Regina and H{\"o}llerl, Annika and Faensen, Katja and Steffen, Ronald and Gross, Matthias and Hoffmann, Cornelia and Haoua, Marsa}, title = {DeepGreen: Etablierung und Weiterentwicklung rechtssicherer Workflows zur effizienten Umsetzung von Open-Access-Komponenten in Lizenzvereinbarungen f{\"u}r wissenschaftliche Publikationen - Abschlussbericht}, issn = {1438-0064}, doi = {10.12752/8542}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-85420}, year = {2022}, abstract = {DeepGreen wurde vom 01.08.2018 bis zum 30.06.2021 in einer zweiten Projektphase von der Deutschen Forschungsgemeinschaft (DFG) gef{\"o}rdert. DeepGreen unterst{\"u}tzt Bibliotheken als Dienstleister f{\"u}r Hochschulen, außeruniversit{\"a}re Forschungseinrichtungen und die dort t{\"a}tigen Wissenschaftler:innen dabei, Publikationen auf Open-Access-Repositorien frei zug{\"a}nglich zu machen und f{\"o}rdert das Zusammenspiel von wissenschaftlichen Einrichtungen und Verlagen. An der zweiten Projektphase waren der Kooperative Bibliotheksverbund Berlin-Brandenburg, die Bayerische Staatsbibliothek, der Bibliotheksverbund Bayern, die Universit{\"a}tsbibliotheken der Friedrich-Alexander-Universit{\"a}t Erlangen-N{\"u}rnberg und der Technischen Universit{\"a}t Berlin und das Helmholtz Open Science Office beteiligt. In dem Projekt wurde erfolgreich eine technische und organisatorische L{\"o}sung zur automatisierten Verteilung von Artikeldaten wissenschaftlicher Verlage an institutionelle und fachliche Repositorien entwickelt. In der zweiten Projektphase lag der Fokus auf der Erprobung der Datendrehscheibe in der Praxis und der Ausweitung auf weitere Datenabnehmer und weitere Verlage. Im Anschluss an die DFG-gef{\"o}rderte Projektlaufzeit ist DeepGreen in einen zweij{\"a}hrigen Pilotbetrieb {\"u}bergegangen. Ziel des Pilotbetriebs ist es, den {\"U}bergang in einen bundesweiten Real-Betrieb vorzubereiten.}, language = {de} } @misc{PetersKottigBrandtnerChristofetal.2023, author = {Peters-Kottig, Wolfgang and Brandtner, Andreas and Christof, J{\"u}rgen and Hauffe, Yves and Koch, Thorsten and Kuo, Leslie and Krause, Katja and M{\"u}ller, Anja and Seeliger, Frank and Stanek, Ursula and St{\"o}hr, Elena and Vetter, Danilo and Winkler, Alexander and Zeyns, Andrea and Rusch, Beate}, title = {KOBV Jahresbericht 2021-2022}, volume = {2021-2022}, address = {Berlin}, organization = {Kooperativer Bibliotheksverbund Berlin-Brandenburg}, issn = {0934-5892}, doi = {10.12752/9116}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-91162}, year = {2023}, language = {de} } @misc{RuschPetersKottigCeynowaetal.2025, author = {Rusch, Beate and Peters-Kottig, Wolfgang and Ceynowa, Klaus and Dinter, Joachim and Dubberke, Ina and Happel, Hans-Gerd and Hilliger, Kirsten and Kitaeva, Xenia and Kleineberg, Michael and Koch, Thorsten and Mc Leod, Shirley and Mutter, Moritz and M{\"u}ller, Anja and Seeliger, Frank and Segger, Elisabeth and Stanek, Ursula and Wiese, Robert and Wrzesinski, Marcel}, title = {KOBV Jahresbericht 2023-2024}, volume = {2023-2024}, address = {Berlin}, organization = {Kooperativer Bibliotheksverbund Berlin-Brandenburg}, issn = {0934-5892}, doi = {10.12752/10044}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-100440}, year = {2025}, language = {de} } @misc{BertelmannBoltzeCeynowaetal.2021, author = {Bertelmann, Roland and Boltze, Julia and Ceynowa, Klaus and Christof, J{\"u}rgen and Faensen, Katja and Groß, Matthias and Hoffmann, Cornelia and Koch, Thorsten and Kuberek, Monika and Lohrum, Stefan and Pampel, Heinz and Putnings, Markus and Retter, Regina and Rusch, Beate and Sch{\"a}ffler, Hildegard and S{\"o}llner, Konstanze and Steffen, Ronald and Wannick, Eike}, title = {DeepGreen: Open-Access-Transformation in der Informationsinfrastruktur - Anforderungen und Empfehlungen, Version 1.0}, issn = {1438-0064}, doi = {10.12752/8150}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-81503}, year = {2021}, abstract = {DeepGreen ist ein Service, der es teilnehmenden institutionellen Open-Access-Repositorien,Open-Access-Fachrepositorien und Forschungsinformationssystemen erleichtert, f{\"u}r sie relevante Verlagspublikationen in zyklischer Abfolge mithilfe von Schnittstellen Open Access zur Verf{\"u}gung zu stellen. Die entsprechende Bandbreite an Relationen zwischen den Akteuren, diverse lizenzrechtliche Rahmenbedingungen sowie technische Anforderungen gestalten das Thema komplex. Ziel dieser Handreichung ist es, neben all diesen Themen, die begleitend beleuchtet werden, im Besonderen Empfehlungen f{\"u}r die reibungslose Nutzung der Daten{\"u}bertragung zu liefern. Außerdem werden mithilfe einer vorangestellten Workflow- Evaluierung Unterschiede und Besonderheiten in den Arbeitsschritten bei institutionellen Open-Access-Repositorien und Open-Access-Fachrepositorien aufgezeigt und ebenfalls mit Empfehlungen angereichert.}, language = {de} } @inproceedings{BreuerBussieckCaoetal.2020, author = {Breuer, Thomas and Bussieck, Michael and Cao, Karl-Kien and Fiand, Fred and Gils, Hans-Christian and Gleixner, Ambros and Khabi, Dmitry and Kempke, Nils and Koch, Thorsten and Rehfeldt, Daniel and Wetzel, Manuel}, title = {BEAM-ME: Accelerating Linear Energy Systems Models by a Massively Parallel Interior Point Method}, volume = {50}, booktitle = {NIC Symposium 2020}, pages = {345 -- 352}, year = {2020}, language = {en} } @article{KochAchterbergAndersenetal.2011, author = {Koch, Thorsten and Achterberg, Tobias and Andersen, Erling and Bastert, Oliver and Berthold, Timo and Bixby, Robert E. and Danna, Emilie and Gamrath, Gerald and Gleixner, Ambros and Heinz, Stefan and Lodi, Andrea and Mittelmann, Hans and Ralphs, Ted and Salvagnin, Domenico and Steffy, Daniel and Wolter, Kati}, title = {MIPLIB 2010}, volume = {3}, journal = {Mathematical Programming Computation}, number = {2}, doi = {10.1007/s12532-011-0025-9}, pages = {103 -- 163}, year = {2011}, language = {en} } @inproceedings{AchterbergBertholdKochetal.2008, author = {Achterberg, Tobias and Berthold, Timo and Koch, Thorsten and Wolter, Kati}, title = {Constraint Integer Programming: A New Approach to Integrate CP and MIP}, volume = {5015}, booktitle = {Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, 5th International Conference, CPAIOR 2008}, editor = {Perron, Laurent and Trick, Michael}, publisher = {Springer}, doi = {10.1007/978-3-540-68155-7_4}, pages = {6 -- 20}, year = {2008}, language = {en} } @inproceedings{BleyKoch2008, author = {Bley, Andreas and Koch, Thorsten}, title = {Integer programming approaches to access and backbone IP-network planning}, booktitle = {Modeling, Simulation and Optimization of Complex Processes, Proceedings of the 3rd International Conference on High Performance Scientific Computing, March 6-10, Hanoi, Vietnam}, publisher = {Springer}, pages = {87 -- 110}, year = {2008}, language = {en} } @article{EisenblaetterGeerdesKochetal.2005, author = {Eisenbl{\"a}tter, Andreas and Geerdes, Hans-Florian and Koch, Thorsten and Martin, Alexander and Wess{\"a}ly, Roland}, title = {UMTS Radio Network Evaluation and Optimization beyond Snapshots}, volume = {63}, journal = {Mathematical Methods of Operations Research}, number = {1}, doi = {10.1007/s00186-005-0002-z}, pages = {1 -- 29}, year = {2005}, language = {en} } @article{BleyKoch2000, author = {Bley, Andreas and Koch, Thorsten}, title = {Optimierung des G-WiN}, journal = {DFN-Mitteilungen}, number = {54}, pages = {13 -- 15}, year = {2000}, language = {en} } @article{AbboudGroetschelKoch2008, author = {Abboud, Nadine and Gr{\"o}tschel, Martin and Koch, Thorsten}, title = {Mathematical methods for physical layout of printed circuit boards: an overview}, volume = {30}, journal = {OR Spectrum}, number = {3}, doi = {10.1007/s00291-007-0080-9}, pages = {453 -- 468}, year = {2008}, language = {en} } @article{AchterbergGroetschelKoch2006, author = {Achterberg, Tobias and Gr{\"o}tschel, Martin and Koch, Thorsten}, title = {Teaching MIP Modeling and Solving}, volume = {33}, journal = {OR/MS Today}, number = {6}, pages = {14 -- 15}, year = {2006}, language = {en} } @misc{FuegenschuhHillerHumpolaetal.2011, author = {F{\"u}genschuh, Armin and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Schwarz, Robert and Schweiger, Jonas and Szab{\´o}, J{\´a}cint}, title = {Gas Network Topology Optimization for Upcoming Market Requirements}, doi = {10.1109/EEM.2011.5953035}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-12348}, number = {11-09}, year = {2011}, abstract = {Gas distribution networks are complex structures that consist of passive pipes, and active, controllable elements such as valves and compressors. Controlling such network means to find a suitable setting for all active components such that a nominated amount of gas can be transmitted from entries to exits through the network, without violating physical or operational constraints. The control of a large-scale gas network is a challenging task from a practical point of view. In most companies the actual controlling process is supported by means of computer software that is able to simulate the flow of the gas. However, the active settings have to be set manually within such simulation software. The solution quality thus depends on the experience of a human planner. When the gas network is insufficient for the transport then topology extensions come into play. Here a set of new pipes or active elements is determined such that the extended network admits a feasible control again. The question again is how to select these extensions and where to place them such that the total extension costs are minimal. Industrial practice is again to use the same simulation software, determine extensions by experience, add them to the virtual network, and then try to find a feasible control of the active elements. The validity of this approach now depends even more on the human planner. Another weakness of this manual simulation-based approach is that it cannot establish infeasibility of a certain gas nomination, unless all settings of the active elements are tried. Moreover, it is impossible to find a cost-optimal network extension in this way. In order to overcome these shortcomings of the manual planning approach we present a new approach, rigorously based on mathematical optimization. Hereto we describe a model for finding feasible controls and then extend this model such that topology extensions can additionally and simultaneously be covered. Numerical results for real-world instances are presented and discussed.}, language = {en} } @misc{BleyKochNiu2008, author = {Bley, Andreas and Koch, Thorsten and Niu, Lingfeng}, title = {Experiments with nonlinear extensions to SCIP}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8300}, number = {08-28}, year = {2008}, abstract = {This paper describes several experiments to explore the options for solving a class of mixed integer nonlinear programming problems that stem from a real-world mine production planning project. The only type of nonlinear constraints in these problems are bilinear equalities involving continuous variables, which enforce the ratios between elements in mixed material streams. A branch-and-bound algorithm to handle the integer variables has been tried in another project. However, this branch-and-bound algorithm is not effective for handling the nonlinear constraints. Therefore state-of-the-art nonlinear solvers are utilized to solve the resulting nonlinear subproblems in this work. The experiments were carried out using the NEOS server for optimization. After finding that current nonlinear programming solvers seem to lack suitable preprocessing capabilities, we preprocess the instances beforehand and use an heuristic approach to solve the nonlinear subproblems. In the appendix, we explain how to add a polynomial constraint handler that uses IPOPT as embedded nonlinear programming solver for the constraint programming framework SCIP. This is one of the crucial steps for implementing our algorithm in SCIP. We briefly described our approach and give an idea of the work involved.}, language = {en} } @incollection{EisenblaetterFuegenschuhKochetal.2002, author = {Eisenbl{\"a}tter, Andreas and F{\"u}genschuh, Armin and Koch, Thorsten and Koster, Arie M.C.A. and Martin, Alexander and Pfender, Tobias and Wegel, Oliver and Wess{\"a}ly, Roland}, title = {Mathematical Model of Feasible Network Configurations for UMTS}, booktitle = {Telecommunications network design and management}, editor = {G. Anandalingam, S.}, publisher = {Kluwer}, pages = {1 -- 24}, year = {2002}, language = {en} } @misc{EisenblaetterFuegenschuhGeerdesetal.2003, author = {Eisenbl{\"a}tter, Andreas and F{\"u}genschuh, Armin and Geerdes, Hans-Florian and Koch, Thorsten and T{\"u}rke, Ulrich and Meijerink, Ellen}, title = {XML Data Specification and Documentation}, publisher = {IST-2000-28088 MOMENTUM Technical Report}, year = {2003}, language = {en} } @inproceedings{EisenblaetterFuegenschuhGeerdesetal.2004, author = {Eisenbl{\"a}tter, Andreas and F{\"u}genschuh, Armin and Geerdes, Hans-Florian and Junglas, Daniel and Koch, Thorsten and Martin, Alexander}, title = {Integer Programming Methods for UMTS Radio Network Planning}, booktitle = {Proceedings of the WiOpt'04, Cambridge, UK}, year = {2004}, language = {en} } @misc{ShinanoAchterbergBertholdetal.2010, author = {Shinano, Yuji and Achterberg, Tobias and Berthold, Timo and Heinz, Stefan and Koch, Thorsten}, title = {ParaSCIP - a parallel extension of SCIP}, doi = {10.1007/978-3-642-24025-6_12}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-11921}, number = {10-27}, year = {2010}, abstract = {Mixed integer programming (MIP) has become one of the most important techniques in Operations Research and Discrete Optimization. SCIP (Solving Constraint Integer Programs) is currently one of the fastest non-commercial MIP solvers. It is based on the branch-and-bound procedure in which the problem is recursively split into smaller subproblems, thereby creating a so-called branching tree. We present ParaSCIP, an extension of SCIP, which realizes a parallelization on a distributed memory computing environment. ParaSCIP uses SCIP solvers as independently running processes to solve subproblems (nodes of the branching tree) locally. This makes the parallelization development independent of the SCIP development. Thus, ParaSCIP directly profits from any algorithmic progress in future versions of SCIP. Using a first implementation of ParaSCIP, we were able to solve two previously unsolved instances from MIPLIB2003, a standard test set library for MIP solvers. For these computations, we used up to 2048 cores of the HLRN~II supercomputer.}, language = {en} } @article{PfetschFuegenschuhGeissleretal.2014, author = {Pfetsch, Marc and F{\"u}genschuh, Armin and Geißler, Bj{\"o}rn and Geißler, Nina and Gollmer, Ralf and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Martin, Alexander and Morsi, Antonio and R{\"o}vekamp, Jessica and Schewe, Lars and Schmidt, Martin and Schultz, R{\"u}diger and Schwarz, Robert and Schweiger, Jonas and Stangl, Claudia and Steinbach, Marc and Vigerske, Stefan and Willert, Bernhard}, title = {Validation of Nominations in Gas Network Optimization: Models, Methods, and Solutions}, journal = {Optimization Methods and Software}, publisher = {Taylor \& Francis}, doi = {10.1080/10556788.2014.888426}, year = {2014}, abstract = {In this article we investigate methods to solve a fundamental task in gas transportation, namely the validation of nomination problem: Given a gas transmission network consisting of passive pipelines and active, controllable elements and given an amount of gas at every entry and exit point of the network, find operational settings for all active elements such that there exists a network state meeting all physical, technical, and legal constraints. We describe a two-stage approach to solve the resulting complex and numerically difficult feasibility problem. The first phase consists of four distinct algorithms applying linear, and methods for complementarity constraints to compute possible settings for the discrete decisions. The second phase employs a precise continuous programming model of the gas network. Using this setup, we are able to compute high quality solutions to real-world industrial instances that are significantly larger than networks that have appeared in the mathematical programming literature before.}, language = {en} } @inproceedings{FuegenschuhHillerHumpolaetal.2011, author = {F{\"u}genschuh, Armin and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Schwarz, Robert and Schweiger, Jonas and Szabo, Jacint}, title = {Gas Network Topology Optimization for Upcoming Market Requirements}, booktitle = {International Conference on the European Energy Market (EEM)}, doi = {10.1109/EEM.2011.5953035}, pages = {346 -- 351}, year = {2011}, abstract = {Gas distribution networks are complex structures that consist of passive pipes, and active, controllable elements such as valves and compressors. Controlling such network means to find a suitable setting for all active components such that a nominated amount of gas can be transmitted from entries to exits through the network, without violating physical or operational constraints. The control of a large-scale gas network is a challenging task from a practical point of view. In most companies the actual controlling process is supported by means of computer software that is able to simulate the flow of the gas. However, the active settings have to be set manually within such simulation software. The solution quality thus depends on the experience of a human planner. When the gas network is insufficient for the transport then topology extensions come into play. Here a set of new pipes or active elements is determined such that the extended network admits a feasible control again. The question again is how to select these extensions and where to place them such that the total extension costs are minimal. Industrial practice is again to use the same simulation software, determine extensions by experience, add them to the virtual network, and then try to find a feasible control of the active elements. The validity of this approach now depends even more on the human planner. Another weakness of this manual simulation-based approach is that it cannot establish infeasibility of a certain gas nomination, unless all settings of the active elements are tried. Moreover, it is impossible to find a cost-optimal network extension in this way. In order to overcome these shortcomings of the manual planning approach we present a new approach, rigorously based on mathematical optimization. Hereto we describe a model for finding feasible controls and then extend this model such that topology extensions can additionally and simultaneously be covered. Numerical results for real-world instances are presented and discussed.}, language = {en} } @inproceedings{BertholdGleixnerHeinzetal.2012, author = {Berthold, Timo and Gleixner, Ambros and Heinz, Stefan and Koch, Thorsten and Shinano, Yuji}, title = {SCIP Optimization Suite を利用した 混合整数(線形/非線形) 計画問題の解法}, booktitle = {Proceedings of the 24th RAMP symposium. The Operations Society of Japan, RAMP: Research Association of Mathematical Programming}, pages = {165 -- 192}, year = {2012}, abstract = {この論文ではソフトウェア・パッケージSCIP Optimization Suite を紹介し,その3つの構成要素:モデリン グ言語Zimpl, 線形計画(LP: linear programming) ソルバSoPlex, そして,制約整数計画(CIP: constraint integer programming) に対するソフトウェア・フレームワークSCIP, について述べる.本論文では,この3つの 構成要素を利用して,どのようにして挑戦的な混合整数線形計画問題(MIP: mixed integer linear optimization problems) や混合整数非線形計画問題(MINLP: mixed integer nonlinear optimization problems) をモデル化 し解くのかを説明する.SCIP は,現在,最も高速なMIP,MINLP ソルバの1つである.いくつかの例により, Zimpl, SCIP, SoPlex の利用方法を示すとともに,利用可能なインタフェースの概要を示す.最後に,将来の開 発計画の概要について述べる.}, language = {ja} } @article{FuegenschuhGeisslerGollmeretal.2013, author = {F{\"u}genschuh, Armin and Geißler, Bj{\"o}rn and Gollmer, Ralf and Hayn, Christine and Henrion, Ren{\´e} and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Martin, Alexander and Mirkov, Radoslava and Morsi, Antonio and R{\"o}misch, Werner and R{\"o}vekamp, Jessica and Schewe, Lars and Schmidt, Martin and Schultz, R{\"u}diger and Schwarz, Robert and Schweiger, Jonas and Stangl, Claudia and Steinbach, Marc and Willert, Bernhard}, title = {Mathematical optimization for challenging network planning problems in unbundled liberalized gas markets}, volume = {5}, journal = {Energy Systems}, number = {3}, publisher = {Springer Berlin Heidelberg}, address = {Berlin}, doi = {10.1007/s12667-013-0099-8}, pages = {449 -- 473}, year = {2013}, abstract = {The recently imposed new gas market liberalization rules in Germany lead to a change of business of gas network operators. While previously network operator and gas vendor were united, they were forced to split up into independent companies. The network has to be open to any other gas trader at the same conditions, and free network capacities have to be identified and publicly offered in a non-discriminatory way. We discuss how these changing paradigms lead to new and challenging mathematical optimization problems. This includes the validation of nominations, that asks for the decision if the network's capacity is sufficient to transport a specific amount of flow, the verification of booked capacities and the detection of available freely allocable capacities, and the topological extension of the network with new pipelines or compressors in order to increase its capacity. In order to solve each of these problems and to provide meaningful results for the practice, a mixture of different mathematical aspects have to be addressed, such as combinatorics, stochasticity, uncertainty, and nonlinearity. Currently, no numerical solver is available that can deal with such blended problems out-of-the-box. The main goal of our research is to develop such a solver, that moreover is able to solve instances of realistic size. In this article, we describe the main ingredients of our prototypical software implementations.}, language = {en} } @article{HoangKoch2012, author = {Hoang, Nam-Dung and Koch, Thorsten}, title = {Steiner tree packing revisited}, volume = {76}, journal = {Mathematical Methods of Operations Research}, number = {1}, doi = {10.1007/s00186-012-0391-8}, pages = {95 -- 123}, year = {2012}, abstract = {The Steiner tree packing problem (STPP) in graphs is a long studied problem in combinatorial optimization. In contrast to many other problems, where there have been tremendous advances in practical problem solving, STPP remains very difficult. Most heuristics schemes are ineffective and even finding feasible solutions is already NP-hard. What makes this problem special is that in order to reach the overall optimal solution non-optimal solutions to the underlying NP-hard Steiner tree problems must be used. Any non-global approach to the STPP is likely to fail. Integer programming is currently the best approach for computing optimal solutions. In this paper we review some "classical" STPP instances which model the underlying real world application only in a reduced form. Through improved modelling, including some new cutting planes, and by emplyoing recent advances in solver technology we are for the first time able to solve those instances in the original 3D grid graphs to optimimality.}, language = {en} } @incollection{BorndoerferHoangKarbsteinetal.2013, author = {Bornd{\"o}rfer, Ralf and Hoang, Nam-Dung and Karbstein, Marika and Koch, Thorsten and Martin, Alexander}, title = {How many Steiner terminals can you connect in 20 years?}, booktitle = {Facets of Combinatorial Optimization; Festschrift for Martin Gr{\"o}tschel}, editor = {J{\"u}nger, Michael and Reinelt, Gerhard}, publisher = {Springer}, doi = {10.1007/978-3-642-38189-8_10}, pages = {215 -- 244}, year = {2013}, language = {en} } @misc{ShinanoAchterbergBertholdetal.2013, author = {Shinano, Yuji and Achterberg, Tobias and Berthold, Timo and Heinz, Stefan and Koch, Thorsten and Winkler, Michael}, title = {Solving hard MIPLIB2003 problems with ParaSCIP on Supercomputers: An update}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-42888}, year = {2013}, abstract = {Contemporary supercomputers can easily provide years of CPU time per wall-clock hour. One challenge of today's software development is how to harness this wast computing power in order to solve really hard mixed integer programming instances. In 2010, two out of six open MIPLIB2003 instances could be solved by ParaSCIP in more than ten consecutive runs, restarting from checkpointing files. The contribution of this paper is threefold: For the first time, we present computational results of single runs for those two instances. Secondly, we provide new improved upper and lower bounds for all of the remaining four open MIPLIB2003 instances. Finally, we explain which new developments led to these results and discuss the current progress of ParaSCIP. Experiments were conducted on HLRNII, on HLRN III, and on the Titan supercomputer, using up to 35,200 cores.}, language = {en} } @misc{BorndoerferHoangKarbsteinetal.2013, author = {Bornd{\"o}rfer, Ralf and Hoang, Nam-Dung and Karbstein, Marika and Koch, Thorsten and Martin, Alexander}, title = {How Many Steiner Terminals Can You Connect in 20 Years?}, issn = {1438-0064}, doi = {10.1007/978-3-642-38189-8_10}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-42524}, year = {2013}, abstract = {Steiner trees are constructed to connect a set of terminal nodes in a graph. This basic version of the Steiner tree problem is idealized, but it can effectively guide the search for successful approaches to many relevant variants, from both a theoretical and a computational point of view. This article illustrates the theoretical and algorithmic progress on Steiner tree type problems on two examples, the Steiner connectivity and the Steiner tree packing problem.}, language = {en} } @article{HumpolaFuegenschuhKoch2016, author = {Humpola, Jesco and F{\"u}genschuh, Armin and Koch, Thorsten}, title = {Valid inequalities for the topology optimization problem in gas network design}, volume = {38}, journal = {OR Spectrum}, number = {3}, publisher = {Springer}, address = {Berlin Heidelberg}, doi = {https://doi.org/10.1007/s00291-015-0390-2}, pages = {597 -- 631}, year = {2016}, abstract = {One quarter of Europe's energy demand is provided by natural gas distributed through a vast pipeline network covering the whole of Europe. At a cost of 1 million Euro per km extending the European pipeline network is already a multi-billion Euro business. Therefore, automatic planning tools that support the decision process are desired. Unfortunately, current mathematical methods are not capable of solving the arising network design problems due to their size and complexity. In this article, we will show how to apply optimization methods that can converge to a proven global optimal solution. By introducing a new class of valid inequalities that improve the relaxation of our mixed-integer nonlinear programming model, we are able to speed up the necessary computations substantially.}, language = {en} } @misc{MaherFischerGallyetal.2017, author = {Maher, Stephen J. and Fischer, Tobias and Gally, Tristan and Gamrath, Gerald and Gleixner, Ambros and Gottwald, Robert Lion and Hendel, Gregor and Koch, Thorsten and L{\"u}bbecke, Marco and Miltenberger, Matthias and M{\"u}ller, Benjamin and Pfetsch, Marc and Puchert, Christian and Rehfeldt, Daniel and Schenker, Sebastian and Schwarz, Robert and Serrano, Felipe and Shinano, Yuji and Weninger, Dieter and Witt, Jonas T. and Witzig, Jakob}, title = {The SCIP Optimization Suite 4.0}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-62170}, year = {2017}, abstract = {The SCIP Optimization Suite is a powerful collection of optimization software that consists of the branch-cut-and-price framework and mixed-integer programming solver SCIP, the linear programming solver SoPlex, the modeling language Zimpl, the parallelization framework UG, and the generic branch-cut-and-price solver GCG. Additionally, it features the extensions SCIP-Jack for solving Steiner tree problems, PolySCIP for solving multi-objective problems, and SCIP-SDP for solving mixed-integer semidefinite programs. The SCIP Optimization Suite has been continuously developed and has now reached version 4.0. The goal of this report is to present the recent changes to the collection. We not only describe the theoretical basis, but focus on implementation aspects and their computational consequences.}, language = {en} } @incollection{KochPfetschRoevekamp2015, author = {Koch, Thorsten and Pfetsch, Marc and R{\"o}vekamp, Jessica}, title = {Introduction}, booktitle = {Evaluating Gas Network Capacities}, publisher = {Society for Industrial and Applied Mathematics}, isbn = {9781611973686}, pages = {3 -- 16}, year = {2015}, language = {en} } @misc{GamrathFischerGallyetal.2016, author = {Gamrath, Gerald and Fischer, Tobias and Gally, Tristan and Gleixner, Ambros and Hendel, Gregor and Koch, Thorsten and Maher, Stephen J. and Miltenberger, Matthias and M{\"u}ller, Benjamin and Pfetsch, Marc and Puchert, Christian and Rehfeldt, Daniel and Schenker, Sebastian and Schwarz, Robert and Serrano, Felipe and Shinano, Yuji and Vigerske, Stefan and Weninger, Dieter and Winkler, Michael and Witt, Jonas T. and Witzig, Jakob}, title = {The SCIP Optimization Suite 3.2}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-57675}, year = {2016}, abstract = {The SCIP Optimization Suite is a software toolbox for generating and solving various classes of mathematical optimization problems. Its major components are the modeling language ZIMPL, the linear programming solver SoPlex, the constraint integer programming framework and mixed-integer linear and nonlinear programming solver SCIP, the UG framework for parallelization of branch-and-bound-based solvers, and the generic branch-cut-and-price solver GCG. It has been used in many applications from both academia and industry and is one of the leading non-commercial solvers. This paper highlights the new features of version 3.2 of the SCIP Optimization Suite. Version 3.2 was released in July 2015. This release comes with new presolving steps, primal heuristics, and branching rules within SCIP. In addition, version 3.2 includes a reoptimization feature and improved handling of quadratic constraints and special ordered sets. SoPlex can now solve LPs exactly over the rational number and performance improvements have been achieved by exploiting sparsity in more situations. UG has been tested successfully on 80,000 cores. A major new feature of UG is the functionality to parallelize a customized SCIP solver. GCG has been enhanced with a new separator, new primal heuristics, and improved column management. Finally, new and improved extensions of SCIP are presented, namely solvers for multi-criteria optimization, Steiner tree problems, and mixed-integer semidefinite programs.}, language = {en} } @article{EisenblaetterFuegenschuhFledderusetal.2003, author = {Eisenbl{\"a}tter, Andreas and F{\"u}genschuh, Armin and Fledderus, E. and Geerdes, Hans-Florian and Heideck, B. and Junglas, Daniel and Koch, Thorsten and K{\"u}rner, T. and Martin, Alexander}, title = {Mathematical Methods for Automatic Optimization of UMTS Radio Networks}, number = {D4.3}, editor = {Martin, Alexander}, publisher = {IST-2000-28088 MOMENTUM}, year = {2003}, language = {en} } @article{EisenblaetterGeerdesJunglasetal.2003, author = {Eisenbl{\"a}tter, Andreas and Geerdes, Hans-Florian and Junglas, Daniel and Koch, Thorsten and K{\"u}rner, T. and Martin, Alexander}, title = {Final Report on Automatic Planning and Optimisation}, number = {D4.7}, publisher = {IST-2000-28088 MOMENTUM}, year = {2003}, language = {en} } @misc{Koch2011, author = {Koch, Thorsten}, title = {Which mixed integer programs could a million CPUs solve?}, journal = {CPAIOR 2011 - Late Breaking Abstracts}, number = {11-20}, editor = {Achterberg, Tobias and Beck, J. Christopher}, publisher = {Zuse Institute Berlin}, address = {Takustr. 7, Berlin}, pages = {17 -- 18}, year = {2011}, language = {en} } @inproceedings{ShinanoAchterbergBertholdetal.2012, author = {Shinano, Yuji and Achterberg, Tobias and Berthold, Timo and Heinz, Stefan and Koch, Thorsten}, title = {ParaSCIP: a parallel extension of SCIP}, booktitle = {Competence in High Performance Computing 2010}, editor = {Bischof, Christian and Hegering, Heinz-Gerd and Nagel, Wolfgang and Wittum, Gabriel}, publisher = {Springer}, doi = {10.1007/978-3-642-24025-6_12}, pages = {135 -- 148}, year = {2012}, language = {en} } @article{KochRalphsShinano2012, author = {Koch, Thorsten and Ralphs, Ted and Shinano, Yuji}, title = {Could we use a million cores to solve an integer program?}, volume = {76}, journal = {Mathematical Methods of Operations Research}, number = {1}, doi = {10.1007/s00186-012-0390-9}, pages = {67 -- 93}, year = {2012}, language = {en} } @incollection{DorndorfDrosteKoch2012, author = {Dorndorf, Ulrich and Droste, Stefan and Koch, Thorsten}, title = {Using ZIMPL for Modeling Production Planning Problems}, booktitle = {Algebraic Modeling Systems}, editor = {Kallrath, Josef}, publisher = {Springer}, doi = {10.1007/978-3-642-23592-4}, pages = {145 -- 158}, year = {2012}, language = {en} } @inproceedings{MartinGeisslerHeynetal.2011, author = {Martin, Alexander and Geißler, Bj{\"o}rn and Heyn, Christine and Hiller, Benjamin and Humpola, Jesco and Koch, Thorsten and Lehmann, Thomas and Morsi, Antonio and Pfetsch, Marc and Schewe, Lars and Schmidt, Martin and Schultz, R{\"u}diger and Schwarz, Robert and Schweiger, Jonas and Steinbach, Marc and Willert, Bernhard}, title = {Optimierung Technischer Kapazit{\"a}ten in Gasnetzen}, booktitle = {Optimierung in der Energiewirtschaft}, publisher = {VDI-Verlag, D{\"u}sseldorf}, pages = {105 -- 114}, year = {2011}, language = {en} } @inproceedings{KochLeoeveyMirkovetal.2011, author = {Koch, Thorsten and Le{\"o}vey, Hernan and Mirkov, Radoslava and R{\"o}misch, Werner and Wegner-Specht, Isabel}, title = {Szenariogenerierung zur Modellierung der stochastischen Ausspeiselasten in einem Gastransportnetz}, booktitle = {Optimierung in der Energiewirtschaft}, publisher = {VDI-Verlag, D{\"u}sseldorf}, pages = {115 -- 125}, year = {2011}, language = {en} } @inproceedings{CookKochSteffyetal.2011, author = {Cook, William and Koch, Thorsten and Steffy, Daniel and Wolter, Kati}, title = {An Exact Rational Mixed-Integer Programming Solver}, volume = {6655}, booktitle = {IPCO 2011}, editor = {G{\"u}nl{\"u}k, Oktay and Woeginger, Gerhard}, doi = {10.1007/978-3-642-20807-2_9}, pages = {104 -- 116}, year = {2011}, language = {en} } @misc{ShinanoAchterbergBertholdetal.2013, author = {Shinano, Yuji and Achterberg, Tobias and Berthold, Timo and Heinz, Stefan and Koch, Thorsten and Vigerske, Stefan and Winkler, Michael}, title = {制約整数計画ソルバ SCIP の並列化}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-18130}, year = {2013}, abstract = {制約整数計画(CIP: Constraint Integer Programming)は,制約プログラミング(CP: Constraint Programming),混合整数計画(MIP: Mixed Integer Programming), 充足可能性問題(SAT: Satisfiability Problems)の研究分野におけるモデリング技術と解法を統合している.その結果,制約整数計画は,広いクラスの最適化問題を扱うことができる.SCIP (Solving Constraint Integer Programs)は,CIPを解くソルバとして実装され,Zuse Institute Berlin (ZIB)の研究者を中心として継続的に拡張が続けられている.本論文では,著者らによって開発されたSCIP に対する2種類の並列化拡張を紹介する. 一つは,複数計算ノード間で大規模に並列動作するParaSCIP である. もう一つは,複数コアと共有メモリを持つ1台の計算機上で(スレッド)並列で動作するFiberSCIP である. ParaSCIP は,HLRN IIスーパーコンピュータ上で, 一つのインスタンスを解くために最大7,168 コアを利用した動作実績がある.また,統計数理研究所のFujitsu PRIMERGY RX200S5上でも,最大512コアを利用した動作実績がある.統計数理研究所のFujitsu PRIMERGY RX200S5上 では,これまでに最適解が得られていなかったMIPLIB2010のインスタンスであるdg012142に最適解を与えた.}, language = {ja} } @misc{CookKochSteffyetal.2012, author = {Cook, William and Koch, Thorsten and Steffy, Daniel and Wolter, Kati}, title = {A Hybrid Branch-and-Bound Approach for Exact Rational Mixed-Integer Programming}, issn = {1438-0064}, doi = {10.1007/s12532-013-0055-6}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-17171}, year = {2012}, abstract = {We present an exact rational solver for mixed-integer linear programming that avoids the numerical inaccuracies inherent in the floating-point computations used by existing software. This allows the solver to be used for establishing theoretical results and in applications where correct solutions are critical due to legal and financial consequences. Our solver is a hybrid symbolic/numeric implementation of LP-based branch-and-bound, using numerically-safe methods for all binding computations in the search tree. Computing provably accurate solutions by dynamically choosing the fastest of several safe dual bounding methods depending on the structure of the instance, our exact solver is only moderately slower than an inexact floating-point branch-and-bound solver. The software is incorporated into the SCIP optimization framework, using the exact LP solver QSopt_ex and the GMP arithmetic library. Computational results are presented for a suite of test instances taken from the MIPLIB and Mittelmann libraries and for a new collection of numerically difficult instances.}, language = {en} } @misc{CookKochSteffyetal.2011, author = {Cook, William and Koch, Thorsten and Steffy, Daniel and Wolter, Kati}, title = {An Exact Rational Mixed-Integer Programming Solver}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-12329}, number = {11-07}, year = {2011}, abstract = {We present an exact rational solver for mixed-integer linear programming that avoids the numerical inaccuracies inherent in the floating-point computations used by existing software. This allows the solver to be used for establishing theoretical results and in applications where correct solutions are critical due to legal and financial consequences. Our solver is a hybrid symbolic/numeric implementation of LP-based branch-and-bound, using numerically-safe methods for all binding computations in the search tree. Computing provably accurate solutions by dynamically choosing the fastest of several safe dual bounding methods depending on the structure of the instance, our exact solver is only moderately slower than an inexact floating-point branch-and-bound solver. The software is incorporated into the SCIP optimization framework, using the exact LP solver QSopt_ex and the GMP arithmetic library. Computational results are presented for a suite of test instances taken from the MIPLIB and Mittelmann collections.}, language = {en} } @article{GamrathKochMaheretal.2017, author = {Gamrath, Gerald and Koch, Thorsten and Maher, Stephen J. and Rehfeldt, Daniel and Shinano, Yuji}, title = {SCIP-Jack - A solver for STP and variants with parallelization extensions}, volume = {9}, journal = {Mathematical Programming Computation}, number = {2}, doi = {10.1007/s12532-016-0114-x}, pages = {231 -- 296}, year = {2017}, abstract = {The Steiner tree problem in graphs is a classical problem that commonly arises in practical applications as one of many variants. While often a strong relationship between different Steiner tree problem variants can be observed, solution approaches employed so far have been prevalently problem-specific. In contrast, this paper introduces a general-purpose solver that can be used to solve both the classical Steiner tree problem and many of its variants without modification. This versatility is achieved by transforming various problem variants into a general form and solving them by using a state-of-the-art MIP-framework. The result is a high-performance solver that can be employed in massively parallel environments and is capable of solving previously unsolved instances.}, language = {en} } @book{GreuelKochPauleetal.2016, author = {Greuel, Martin and Koch, Thorsten and Paule, Peter and Sommese, Andrew}, title = {Mathematical Software - ICMS 2016, 5th Int. Conf. Berlin, Germany, July 11-14, 2016, Proceedings}, volume = {9725}, journal = {Lecture Notes in Computer Science (LNCS)}, publisher = {Springer}, isbn = {978-3-319-42431-6}, doi = {10.1007/978-3-319-42432-3}, pages = {XXIV, 532}, year = {2016}, language = {en} }