@article{BosseGroetschelHenk2005, author = {Bosse, Hartwig and Gr{\"o}tschel, Martin and Henk, Martin}, title = {Polynomial inequalities representing polyhedra}, volume = {103}, journal = {Mathematical Programming}, number = {1}, doi = {10.1007/s10107-004-0563-2}, pages = {35 -- 44}, year = {2005}, language = {en} } @article{GroetschelHenk2003, author = {Gr{\"o}tschel, Martin and Henk, Martin}, title = {The Representation of Polyhedra by Polynomial Inequalities}, volume = {29}, journal = {Discrete \& Computational Geometry}, number = {4}, doi = {10.1007/s00454-003-0782-y}, pages = {485 -- 504}, year = {2003}, language = {en} } @article{BorndoerferEisenblaetterGroetscheletal.1998, author = {Bornd{\"o}rfer, Ralf and Eisenbl{\"a}tter, Andreas and Gr{\"o}tschel, Martin and Martin, Alexander}, title = {Frequency assignment in cellular phone networks}, volume = {76}, journal = {Annals of Operations Research}, publisher = {J. C. Baltzer AG, Science Publishers}, doi = {10.1023/A:1018908907763}, pages = {73 -- 93}, year = {1998}, language = {en} } @article{GroetschelMartinWeismantel1996, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {Packing Steiner trees: a cutting plane algorithm and computational results}, volume = {72}, journal = {Mathematical Programming, Series A}, number = {2}, doi = {10.1007/BF02592086}, pages = {125 -- 145}, year = {1996}, language = {en} } @article{GroetschelMartinWeismantel1997, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {The Steiner tree packing problem in VLSI design}, volume = {78}, journal = {Mathematical Programming}, number = {2}, pages = {265 -- 281}, year = {1997}, language = {en} } @inproceedings{GroetschelMartinWeismantel1993, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {Routing in grid graphs by cutting planes}, booktitle = {Integer Programming and Combinatorial Optimization. Proceedings of a Conference held at Centro Ettore Majorana, Erice, Italy, April 29 - May 1, 1993}, editor = {Rinaldi, Giovanni and Wolsey, Laurence}, publisher = {Librarian CORE}, address = {Louvain-la-Neuve}, pages = {447 -- 461}, year = {1993}, language = {en} } @article{FerreiraGroetschelMartinetal.1993, author = {Ferreira, Carlos and Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert and Kiefl, Stefan and Krispenz, Ludwig}, title = {Some Integer Programs Arising in the Design of Main Frame Computers}, volume = {38}, journal = {ZOR - Methods and Models of Operations Research}, number = {1}, pages = {77 -- 100}, year = {1993}, language = {en} } @article{GroetschelMartinWeismantel1995, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {Routing in Grid Graphs by Cutting Planes}, volume = {41}, journal = {ZOR - Mathematical Methods of Operations Research}, number = {3}, pages = {255 -- 275}, year = {1995}, language = {en} } @article{GroetschelMartinWeismantel1996, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {Packing Steiner Trees: Separation Algorithms}, volume = {9}, journal = {SIAM Journal on Discrete Mathematics}, number = {2}, doi = {10.1137/S0895480193258716}, pages = {233 -- 257}, year = {1996}, language = {en} } @article{GroetschelMartinWeismantel1996, author = {Gr{\"o}tschel, Martin and Martin, Alexander and Weismantel, Robert}, title = {Packing Steiner Trees: Further Facets}, volume = {17}, journal = {European Journal of Combinatorics}, number = {1}, doi = {10.1006/eujc.1996.0004}, pages = {39 -- 52}, year = {1996}, language = {en} } @inproceedings{BorndoerferEisenblaetterGroetscheletal.1996, author = {Bornd{\"o}rfer, Ralf and Eisenbl{\"a}tter, Andreas and Gr{\"o}tschel, Martin and Martin, Alexander}, title = {Stable-Set and Other Techniques for Frequency Assignment Problems}, booktitle = {Anais da I Oficina Nacional em Problemas de Corte \& Empacotamento}, publisher = {Universidade de S{\~a}o Paulo, Instituto de Matem{\´a}tica e Estat{\´i}stica}, pages = {17 -- 21}, year = {1996}, language = {en} } @misc{GroetschelLuegger2009, author = {Gr{\"o}tschel, Martin and L{\"u}gger, Joachim}, title = {Ver{\"a}nderungen der Publikations- und Kommunikationswelt: Open Access, Google, etc.}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-11223}, number = {09-10}, year = {2009}, abstract = {Vorbemerkung Beim Schreiben dieses Artikels, der auf Ver{\"a}nderungen der Kommunikations- und Publikationstechniken und ihre Bedeutung hinweist, ist uns mehr als je zuvor bewusst geworden, wie beschr{\"a}nkt das Medium Papier ist. Es gibt z. B. keine Hyperlinks, durch die man unmittelbar das Erw{\"a}hnte erleben oder {\"u}berpr{\"u}fen kann. Ein schneller Wechsel vom Wort zum Bild, zum Ton oder Video ist nicht m{\"o}glich. Wer will schon lange URLs abtippen und Medienbr{\"u}che erleiden? Wir haben uns daher entschlossen, eine textidentische Version dieses Artikels mit allen URLs - sie liegt Ihnen hier vor - elektronisch anzubieten und in der f{\"u}r die "Gegenworte" (BBAW) gek{\"u}rzten Fassung nur durch [URL] anzudeuten, dass der Leser an dieser Stelle einfach in der elektronischen Version einen Klick ins Internet machen sollte. Und damit sind wir bereits mitten im Thema.}, language = {de} } @misc{GroetschelLuegger2009, author = {Gr{\"o}tschel, Martin and L{\"u}gger, Joachim}, title = {E-Learning and the Working Mathematician}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-11455}, number = {09-29}, year = {2009}, abstract = {Eigentlich war der erste Autor nur zu einem Grußwort zur Tagung „GML² 2009 - Grundfragen Multi¬medialen Lehrens und Lernens" eingeladen. Daraus wurde ein E-Learning-bezogener Vortrag, der - basierend auf Erfahrungen im Fach Mathematik - einen kritischen Blick auf die E-Learning-Szene in Deutschland wirft und diese mit entsprechenden Aktivit{\"a}ten weltweit vergleicht. Dies ist die in seinen mathematischen Teilen gek{\"u}rzte, in den E-Learning-Anteilen ein wenig erweiterte schriftliche Fassung des Vortrags. Der Artikel stammt nicht von E-Learning-Spezialisten sondern von Personen, die sich seit fast zwanzig Jahren mit elektronischer Information und Kommunikation (kurz: IuK) - insbesondere in der Mathematik - besch{\"a}ftigen. Nach einer Definition von Michael Kerres kennzeichnet der Begriff E-Learning (electronic learning - elektronisch unterst{\"u}tztes Lernen) alle Formen von Lernen, bei denen digitale Medien f{\"u}r die Pr{\"a}sentation und Distribution von Lernmaterialien und/oder zur Unterst{\"u}tzung zwischenmenschlicher Kommunikation zum Einsatz kommen, siehe z.B. http://de.wikipedia.org/wiki/E-Learning. IuK und E-Learning haben nach dieser Begriffsbildung viele Ber{\"u}hrungspunkte. Deswegen wagen wir es, unsere positiven und negativen Erfahrungen im Bereich IuK in diesem Er{\"o}ffnungsvortrag zu berichten, einige Entwicklungslinien zu vergleichen und eine eigene Kurzversion der Definition von E-Learning (besser E-Teaching and -Learning) voranzustellen: „Lehren und Lernen mit Unterst{\"u}tzung elektronischer Hilfsmittel".}, language = {de} } @misc{Groetschel2005, author = {Gr{\"o}tschel, Martin}, title = {Das Problem mit der Komplexit{\"a}t: P = NP?}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8916}, number = {05-58}, year = {2005}, abstract = {Was Komplexit{\"a}t ist, weiß niemand so richtig. In vielen Wissenschaftsgebieten wird der Begriff Komplexit{\"a}t verwendet, {\"u}berall mit etwas anderer Bedeutung. Mathematik und Informatik hab en eine eigene Theorie hierzu entwickelt: die Komplexit{\"a}tstheorie. Sie stellt zwar grundlegende Begriffe bereit, aber leider sind die meisten wichtigen Fragestellungen noch ungel{\"o}st. Diese kurze Einf{\"u}hrung konzentriert sich auf einen speziellen, aber bedeutenden Aspekt der Theorie: L{\"o}sbarkeit von Problemen in deterministischer und nichtdeterministischer polynomialer Zeit. Hinter der f{\"u}r Uneingeweihte etwas kryptischen Frage "P = NP?" verbirgt sich das derzeit wichtigste Problem der Komplexit{\"a}tstheorie. Anhand dieser Fragestellung werden einige Aspekte der Theorie erl{\"a}utert und formell erkl{\"a}rt, was "P = NP?" bedeutet. Es geht nicht nur um komplizierte algorithmische Mathematik und Informatik, sondern um grunds{\"a}tzliche Fragen unserer Lebensumwelt. Kann man vielleicht beweisen, dass es f{\"u}r viele Probleme unseres Alltags keine effizienten L{\"o}sungsmethoden gibt?}, language = {de} } @misc{BorndoerferGroetschelPfetsch2005, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Pfetsch, Marc}, title = {A Column-Generation Approach to Line Planning in Public Transport}, doi = {/10.1287/trsc.1060.0161}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8522}, number = {05-18}, year = {2005}, abstract = {The line planning problem is one of the fundamental problems in strategic planning of public and rail transport. It consists in finding lines and corresponding frequencies in a transport network such that a given travel demand can be satisfied. There are (at least) two objectives. The transport company wishes to minimize operating costs, the passengers want to minimize travel times. We propose a n ew multi-commodity flow model for line planning. Its main features, in comparison to existing models, are that the passenger paths can be freely routed and that the lines are generated dynamically. We discuss properties of this model and investigate its complexity. Results with data for the city of Potsdam, Germany, are reported.}, language = {en} } @misc{BorndoerferGroetschelPfetsch2005, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Pfetsch, Marc}, title = {Public Transport to the fORe!}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8562}, number = {05-22}, year = {2005}, abstract = {Can OR methods help the public transport industry to break even? The article gives evidence that there exist significant potentials in this direction, which can be harnessed by a combination of modern mathematical methods and local planning knowledge. Many of the planning steps in public transport are classical combinatorial problems, which can be solved in unprecedented size and quality due the rapid progress in large-scale optimization. Three examples on vehicle scheduling, duty scheduling, and integrated vehicle and duty scheduling illustrate the level that has been reached and the improvements that can be achieved today. Extensions of such methods to further questions of strategic, online, and market-oriented planning are currently investigated. In this way, OR can make a significant contribution to answer the basic but extremely difficult question ``What is a good public transport network?.}, language = {en} } @misc{GroetschelRoggenbuckSperber2005, author = {Gr{\"o}tschel, Martin and Roggenbuck, Robert and Sperber, Wolfram}, title = {Entwicklung und Aufbau des Internet-Dienstes "Math\&Industry"}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8573}, number = {05-23}, year = {2005}, abstract = {Die Anwendung mathematischer Methoden und Verfahren wird immer mehr zur Voraussetzung innovativer Produkte und Dienstleistungen. Um neue Produkte und Dienstleistungen zu entwickeln, m{\"u}ssen die Produktions- und technologischen Prozesse mathematisch modelliert, beschrieben und optimiert werden. Diesen Umstand Rechnung tragend, hat das Bundesministerium f{\"u}r Bildung und Forschung (BMBF) 1993 begonnen, den Einsatz mathematischer Verfahren und Methoden in der Mathematik {\"u}ber ein spezielles Mathematikprogramm zu f{\"o}rdern. Inzwischen hat die vierte F{\"o}rderperiode des Mathematikprogramms begonnen. \par Das Medium Internet und insbesondere das WWW sind f{\"u}r die Sichtbarkeit und Transparenz wissenschaftlicher Resultate in den letzten zehn Jahren immer wichtiger geworden. Wer nicht im Web "'sichtbar"' ist, l{\"a}uft Gefahr, nicht wahrgenommen zu werden. Intention und Ziel des durchgef{\"u}hrten Projekts war es, ein Konzept f{\"u}r eine qualitativ hochwertige und umfassende Darstellung des BMBF Mathematikprogramms, insbesondere der in den Projekten erzielten Ergebnisse, zu entwickeln und zu realisieren und damit den Stellenwert und die Akzeptanz mathematischer Forschung in der Gesellschaft zu festigen und den Wissenstransfer zwischen mathematischer Forschung sowie Forschung und Entwicklung in der Wirtschaft und dem Dienstleistungsbereich zu f{\"o}rdern.}, language = {de} } @misc{Groetschel2005, author = {Gr{\"o}tschel, Martin}, title = {Schnelle Rundreisen: Das Travelling Salesman-Problem}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-8901}, number = {05-57}, year = {2005}, abstract = {Das Travelling-Salesman-Problem (TSP) ist das am intensivsten untersuchte kombinatorische Optimierungsproblem. In diesem Abschnitt wird eine Einf{\"u}hrung in das TSP gegeben. Es werden Problemstellungen erl{\"a}utert, Anwendungen skizziert und einige Schwierigkeiten bei der korrekten Modellierung der Zielfunktion dargelegt. Es ist gar nicht so klar, was in einem konkreten Problem die wirkliche Entfernung ist. Exakte und approximative L{\"o}sungsverfahren werden an Beispielen skizziert, und es wird angedeutet, dass man, obwohl TSPs zu den theoretisch schweren Problemen z{\"a}hlen, in der Praxis TSPs von atemberaubender Gr{\"o}ße l{\"o}sen kann.}, language = {de} } @misc{GroetschelHinrichsSchroeeretal.2006, author = {Gr{\"o}tschel, Martin and Hinrichs, Hinrich and Schr{\"o}er, Klaus and Tuchscherer, Andreas}, title = {Ein gemischt-ganzzahliges lineares Optimierungsmodell f{\"u}r ein Laserschweißproblem im Karosseriebau}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-9141}, number = {06-21}, year = {2006}, abstract = {Wir besch{\"a}ftigen uns mit dem Problem der Betriebsplanung von Laserschweißrobotern im Karosseriebau. Gegeben ist eine Menge von Schweißn{\"a}hten, die innerhalb einer Fertigungszelle an einem Karosserieteil gefertigt werden m{\"u}ssen. Die Schweißn{\"a}hte werden durch mehrere parallel betriebene Roboter bearbeitet. Die Aufgabe besteht darin, f{\"u}r jeden Roboter eine Reihenfolge und eine zeitliche Koordinierung seiner Bewegungen zu finden, so dass alle Schweißn{\"a}hte innerhalb der Taktzeit der Fertigungszelle bearbeitet werden und so wenig Laserquellen wie m{\"o}glich eingesetzt werden. Dabei m{\"u}ssen einige Nebenbedingungen ber{\"u}cksichtigt werden. F{\"u}r dieses spezielle Schweißproblem haben wir eine Formulierung als gemischt-ganzzahliges lineares Programm entwickelt, welches sich f{\"u}r die untersuchten praktischen F{\"a}lle sehr schnell l{\"o}sen l{\"a}sst.}, language = {de} } @misc{AchterbergGroetschelKoch2006, author = {Achterberg, Tobias and Gr{\"o}tschel, Martin and Koch, Thorsten}, title = {Software for Teaching Modeling of Integer Programming Problems}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-9176}, number = {06-23}, year = {2006}, abstract = {Modern applications of mathematical programming must take into account a multitude of technical details, business demands, and legal requirements. Teaching the mathematical modeling of such issues and their interrelations requires real-world examples that are well beyond the toy sizes that can be tackled with the student editions of most commercial software packages. We present a new tool, which is freely available for academic use including complete source code. It consists of an algebraic modeling language and a linear mixed integer programming solver. The performance and features of the tool are in the range of current state-of-the-art commercial tools, though not in all aspects as good as the best ones. Our tool does allow the execution and analysis of large real-world instances in the classroom and can therefore enhance the teaching of problem solving issues. Teaching experience has been gathered and practical usability was tested in classes at several universities and a two week intensive block course at TU Berlin. The feedback from students and teachers has been very positive.}, language = {en} } @misc{BorndoerferGroetschelLoebel2000, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and L{\"o}bel, Andreas}, title = {Der schnellste Weg zum Ziel}, journal = {Alles Mathematik}, editor = {Aigner, Martin and Behrends, Ehrhard}, publisher = {Vieweg Verlag}, address = {Braunschweig/Wiesbaden}, doi = {10.1007/978-3-322-96366-6_5}, pages = {45 -- 76}, year = {2000}, language = {en} } @incollection{BorndoerferGroetschelJaeger2008, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Jaeger, Ulrich}, title = {Planungsprobleme im {\"o}ffentlichen Verkehr}, booktitle = {PRODUKTIONSFAKTOR MATHEMATIK - Wie Mathematik Technik und Wirtschaft bewegt}, editor = {Gr{\"o}tschel, Martin and Lucas, Klaus and Mehrmann, Volker}, publisher = {acatech - Deutsche Akademie der Technikwissenschaften und Springer}, pages = {127 -- 153}, year = {2008}, language = {en} } @inproceedings{BorndoerferGroetschelPfetsch2008, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Pfetsch, Marc}, title = {Models for Line Planning in Public Transport}, volume = {600}, booktitle = {Computer-aided Systems in Public Transport (CASPT 2004)}, editor = {Hickman, Mark and Mirchandani, Pitu and Voß, Stefan}, publisher = {Springer-Verlag}, doi = {10.1007/978-3-540-73312-6_18}, pages = {363 -- 378}, year = {2008}, language = {en} } @misc{Groetschel1973, type = {Master Thesis}, author = {Gr{\"o}tschel, Martin}, title = {Der Satz von Frobenius f{\"u}r konvergente Potenzreihen}, year = {1973}, language = {en} } @article{GroetschelPadberg1975, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {Partial linear characterizations of the asymmetric travelling salesman polytope}, volume = {8}, journal = {Mathematical Programming}, pages = {378 -- 381}, year = {1975}, language = {en} } @inproceedings{Groetschel1976, author = {Gr{\"o}tschel, Martin}, title = {{\"U}ber Graphen mit Kreisen, die gegebene Wege enthalten}, volume = {5}, booktitle = {Proceedings in Operations Research}, editor = {Kohlas, J{\"u}rg and Seifert, Olaf and Zimmermann, H.}, publisher = {Physica-Verlag}, address = {W{\"u}rzburg}, pages = {119 -- 121}, year = {1976}, language = {en} } @incollection{Groetschel1977, author = {Gr{\"o}tschel, Martin}, title = {Graphs with cycles containing given paths}, volume = {1}, booktitle = {Studies in Integer Programming}, editor = {Hammer, Peter and Johnson, Ellis and Korte, Bernhard and Nemhauser, George}, publisher = {North-Holland}, pages = {233 -- 245}, year = {1977}, language = {en} } @book{Groetschel1977, author = {Gr{\"o}tschel, Martin}, title = {Polyedrische Charakterisierungen kombinatorischer Optimierungsprobleme}, volume = {36}, journal = {Mathematical Systems in Economics}, publisher = {Verlag Anton Hain}, address = {Meisenheim am Glan}, isbn = {3-445-01537-6}, year = {1977}, language = {en} } @inproceedings{Groetschel1977, author = {Gr{\"o}tschel, Martin}, title = {The monotone 2-matching polytope on a complete graph}, booktitle = {Operations Research Verfahren XXIV, Symposium in Mannheim}, pages = {72 -- 84}, year = {1977}, language = {en} } @inproceedings{Groetschel1977, author = {Gr{\"o}tschel, Martin}, title = {Facetten von Matroid-Polytopen}, booktitle = {Operations Research Verfahren XXV, Symposium Heidelberg 1976}, pages = {306 -- 313}, year = {1977}, language = {en} } @incollection{GroetschelKorte1977, author = {Gr{\"o}tschel, Martin and Korte, Bernhard}, title = {Bemerkungen zur Optimierung {\"o}konomischer Modelle}, booktitle = {Quantitative Wirtschaftsforschung, Willhelm Krelle zum 60. Geburtstag}, editor = {Albach, Horst and Helmst{\"a}dter, Ernst and Henn, Rudolf}, publisher = {J. C. B. Mohr}, address = {T{\"u}bingen}, pages = {457 -- 467}, year = {1977}, language = {en} } @article{GroetschelPadberg1977, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {Lineare Charakterisierungen von Travelling Salesman Problemen}, volume = {21}, journal = {Zeitschrift f{\"u}r Operations Research, Series A}, number = {1}, publisher = {Physica-Verlag}, pages = {33 -- 64}, year = {1977}, language = {en} } @article{Groetschel1978, author = {Gr{\"o}tschel, Martin}, title = {Hypo-Hamiltonian Facets of the Symmetric Travelling Salesman Polytope}, volume = {58}, journal = {Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik}, pages = {T469 -- T471}, year = {1978}, language = {en} } @inproceedings{GroetschelPadberg1978, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {On the symmetric travelling salesman problem}, volume = {157}, booktitle = {Optimization and operations research, Proc. Workshop, Bonn 1977}, editor = {Henn, Rudolf and Korte, Bernhard and Oettli, W.}, publisher = {Springer}, pages = {105 -- 115}, year = {1978}, language = {en} } @article{GroetschelvonRandow1978, author = {Gr{\"o}tschel, Martin and von Randow, Rabe}, title = {A property of continuous unbounded algorithms}, volume = {14}, journal = {Mathematical Programming}, pages = {373 -- 377}, year = {1978}, language = {en} } @article{Groetschel1979, author = {Gr{\"o}tschel, Martin}, title = {On minimal strong blocks}, volume = {3}, journal = {Journal of Graph Theory}, pages = {213 -- 219}, year = {1979}, language = {en} } @inproceedings{Groetschel1979, author = {Gr{\"o}tschel, Martin}, title = {Strong blocks and the optimum branching problem}, volume = {46}, booktitle = {Numerische Methoden bei graphentheoretischen und kombinatorischen Problemen, Bd. 2, Tagung in Oberwolfach 1978}, editor = {Collatz, Lothar and Meinardus, G. and Wetterling (Hrsg.), W.}, publisher = {Birkh{\"a}user}, address = {Basel}, pages = {112 -- 121}, year = {1979}, language = {en} } @article{GroetschelHarary1979, author = {Gr{\"o}tschel, Martin and Harary, Frank}, title = {The Graphs for which All Strong Orientations Are Hamiltonian}, volume = {3}, journal = {Journal of Graph Theory}, pages = {221 -- 223}, year = {1979}, language = {en} } @article{GroetschelPadberg1979, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {On the symmetric travelling salesman problem I}, volume = {16}, journal = {Mathematical Programming}, pages = {265 -- 280}, year = {1979}, language = {en} } @article{GroetschelPadberg1979, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {On the symmetric travelling salesman problem II}, volume = {16}, journal = {Mathematical Programming}, pages = {281 -- 302}, year = {1979}, language = {en} } @article{Groetschel1980, author = {Gr{\"o}tschel, Martin}, title = {On the symmetric travelling salesman problem}, volume = {12}, journal = {Mathematical Programming Study}, publisher = {North-Holland}, pages = {61 -- 77}, year = {1980}, language = {en} } @article{Groetschel1980, author = {Gr{\"o}tschel, Martin}, title = {On the monotone symmetric travelling salesman problem}, volume = {5}, journal = {Mathematics of Operations Research}, number = {2}, pages = {285 -- 292}, year = {1980}, language = {en} } @incollection{GroetschelWakabayashi1990, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {Composition of facets of the clique partitioning polytope}, booktitle = {Topics in combinatorics and graph theory. Essays in honour of Gerhard Ringel}, editor = {Bodendiek, Rainer and Henn, Rudolf}, publisher = {Physica-Verlag}, address = {Heidelberg}, pages = {271 -- 284}, year = {1990}, language = {en} } @inproceedings{GroetschelJuengerReinelt1987, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {Calculating Exact Ground States of Spin Glasses}, booktitle = {Proceedings of the Heidelberg Colloquium on "Glassy Dynamics", Lecture Notes in Physics 275}, editor = {van Hemmen, J. and Morgenstern, I.}, publisher = {Springer}, pages = {325 -- 353}, year = {1987}, language = {en} } @article{BarahonaGroetschelJuengeretal.1988, author = {Barahona, Francisco and Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {An application of combinatorial optimization to statistical physics and circuit layout design}, volume = {36}, journal = {Operations Research}, number = {3}, pages = {493 -- 513}, year = {1988}, language = {en} } @book{GroetschelLovaszSchrijver1988, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {Geometric Algorithms and Combinatorial Optimization}, volume = {2}, journal = {Algorithms and Combinatorics}, publisher = {Springer}, isbn = {3-540-13624-X, 0-387-13624-X (U.S.)}, year = {1988}, language = {en} } @article{GroetschelJuengerReinelt1989, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {Via Minimization with Pin Preassignments and Layer Preference}, volume = {69}, journal = {ZAMM - Zeitschrift f{\"u}r Angewandte Mathematik und Mechanik}, number = {11}, pages = {393 -- 399}, year = {1989}, language = {en} } @article{GroetschelTruemper1989, author = {Gr{\"o}tschel, Martin and Truemper, Klaus}, title = {Decomposition and Optimization over Cycles in Binary Matroids}, volume = {46}, journal = {Journal of Combinatorial Theory, Series B}, number = {3}, pages = {306 -- 337}, year = {1989}, language = {en} } @article{GroetschelTruemper1989, author = {Gr{\"o}tschel, Martin and Truemper, Klaus}, title = {Master Polytopes for Cycles of Binary Matroids}, volume = {114/115}, journal = {Linear Algebra and its Applications}, pages = {523 -- 540}, year = {1989}, language = {en} } @article{GroetschelWakabayashi1989, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {A cutting plane algorithm for a clustering problem}, volume = {45}, journal = {Mathematical Programming, Series B}, publisher = {Mathematical Programming, Series B}, pages = {59 -- 96}, year = {1989}, language = {en} } @inproceedings{AscheuerEscuderoGroetscheletal.1990, author = {Ascheuer, Norbert and Escudero, Laureano and Gr{\"o}tschel, Martin and Stoer, Mechthild}, title = {On Identifying in Polynomial Time Violated Subtour Elimination and Precedence Forcing Constraints for the Sequential Ordering Problem}, booktitle = {Integer Programming and Combinatorial Optimization, Proceeedings of a Conference held at the University of Waterloo, May 28-30, 1990}, editor = {Kannan, Ravi and Pulleyblank, William}, publisher = {University of Waterloo Press}, pages = {19 -- 28}, year = {1990}, language = {en} } @article{GroetschelMonma1990, author = {Gr{\"o}tschel, Martin and Monma, Clyde}, title = {Integer Polyhedra Arising from Certain Network Design Problems with Connectivity Constraints}, volume = {3}, journal = {SIAM Journal on Discrete Mathematics}, number = {4}, pages = {502 -- 523}, year = {1990}, language = {en} } @article{GroetschelWakabayashi1990, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {Facets of the clique partitioning polytope}, volume = {47}, journal = {Mathematical Programming, Series A}, number = {3}, pages = {367 -- 387}, year = {1990}, language = {en} } @article{GroetschelJuengerReinelt1984, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {Optimal triangulation of large real world input-output matrices}, volume = {25}, journal = {Statistische Hefte}, pages = {261 -- 295}, year = {1984}, language = {en} } @inproceedings{GroetschelLovaszSchrijver1984, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {Geometric Methods in Combinatorial Optimization}, booktitle = {Progress in Combinatorial Optimization, (Conference Waterloo/Ontario 1982)}, editor = {Pulleyblank, William}, publisher = {Academic Press}, pages = {167 -- 183}, year = {1984}, language = {en} } @incollection{GroetschelLovaszSchrijver1984, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {Polynomial algorithms for perfect graphs}, volume = {21}, booktitle = {Topics on perfect graphs}, editor = {Berge, Claude and Chv{\´a}tal, Vašek}, publisher = {North-Holland}, pages = {325 -- 356}, year = {1984}, language = {en} } @article{GroetschelLovaszSchrijver1984, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {Corrigendum to our paper "The ellipsoid method and its consequences in combinatorial optimization"}, volume = {4}, journal = {Combinatorica}, number = {4}, pages = {291 -- 295}, year = {1984}, language = {en} } @article{GroetschelNemhauser1984, author = {Gr{\"o}tschel, Martin and Nemhauser, George}, title = {A polynomial algorithm for the max-cut problem on graphs without long odd cycles}, volume = {29}, journal = {Mathematical Programming}, number = {1}, publisher = {North-Holland}, pages = {28 -- 40}, year = {1984}, language = {en} } @inproceedings{GroetschelWakabayashi1984, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {Constructions of hypotraceable digraphs}, booktitle = {Mathematical Programming. Proceedings of the International Congress on Mathematical Programming, Rio de Janeiro, Brazil, 6-8 April 1981}, editor = {Cottle, Richard and Kelmanson, Milton and Korte, Bernhard}, publisher = {North-Holland}, pages = {147 -- 175}, year = {1984}, language = {en} } @article{BarahonaGroetschelMahjoub1985, author = {Barahona, Francisco and Gr{\"o}tschel, Martin and Mahjoub, Ali}, title = {Facets of the Bipartite Subgraph Polytope}, volume = {10}, journal = {Mathematics of Operations Research}, pages = {340 -- 358}, year = {1985}, language = {en} } @article{GroetschelHolland1985, author = {Gr{\"o}tschel, Martin and Holland, Olaf}, title = {Solving matching problems with linear programming}, volume = {33}, journal = {Mathematical Programming}, number = {3}, pages = {243 -- 259}, year = {1985}, language = {en} } @inproceedings{GroetschelJuengerReinelt1985, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {Acyclic subdigraphs and linear orderings}, booktitle = {Graphs and Order. The Role of Graphs in the Theory of Ordered Sets and its Applications, Proceedings of NATO ASI, Ser. C 147, Banff/Canada 1984}, editor = {Rival, Ivan}, publisher = {D. Reidel Publishing Company}, pages = {217 -- 264}, year = {1985}, language = {en} } @article{GroetschelJuengerReinelt1985, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {On the acyclic subgraph polytope}, volume = {33}, journal = {Mathematical Programming}, number = {1}, publisher = {North-Holland}, pages = {28 -- 42}, year = {1985}, language = {en} } @article{GroetschelJuengerReinelt1985, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {Facets of the linear ordering polytope}, volume = {33}, journal = {Mathematical Programming}, number = {1}, publisher = {North-Holland}, pages = {43 -- 60}, year = {1985}, language = {en} } @incollection{GroetschelPadberg1985, author = {Gr{\"o}tschel, Martin and Padberg, Manfred}, title = {Polyhedral theory}, booktitle = {The Traveling Salesman Problem. A Guided Tour of Combinatorial Optimization}, editor = {Lawler, Eugene and Lenstra, Jan and Kan, Alexander and Shmoys, David}, publisher = {Wiley}, pages = {251 -- 306}, year = {1985}, language = {en} } @incollection{PadbergGroetschel1985, author = {Padberg, Manfred and Gr{\"o}tschel, Martin}, title = {Polyhedral computations}, booktitle = {The Traveling Salesman Problem. A Guided Tour of Combinatorial Optimization}, editor = {Lawler, Eugene and Lenstra, Jan and Kan, Alexander and Shmoys, David}, publisher = {Wiley}, pages = {307 -- 360}, year = {1985}, language = {en} } @techreport{BarahonaGroetschel1985, author = {Barahona, Francisco and Gr{\"o}tschel, Martin}, title = {The Travelling Salesman Problem for Graphs not Contractible to K_5 - e}, number = {77}, publisher = {Mathematisches Institut, Universit{\"a}t Augsburg}, year = {1985}, language = {en} } @article{BarahonaGroetschel1986, author = {Barahona, Francisco and Gr{\"o}tschel, Martin}, title = {On the Cycle Polytope of a Binary Matroid}, volume = {40}, journal = {Journal of Combinatorial Theory, Series B}, pages = {40 -- 62}, year = {1986}, language = {en} } @inproceedings{Groetschel1986, author = {Gr{\"o}tschel, Martin}, title = {Polyedrische Kombinatorik und Schnittebenenverfahren, Tagungsbericht 2. Sommerschule Diskrete Strukturen, Bayreuth 1985}, volume = {21}, booktitle = {Diskrete Strukturen, algebraische Methoden und Anwendungen}, editor = {Kerber, Adalbert}, publisher = {Institut f{\"u}r Mathematik, Universit{\"a}t Bayreuth}, pages = {69 -- 100}, year = {1986}, language = {en} } @incollection{Groetschel1986, author = {Gr{\"o}tschel, Martin}, title = {Fortschritte in der polyedrischen Kombinatorik}, booktitle = {{\"O}konomische Prognose-, Entscheidungs- und Gleichgewichtsmodelle, Abschlußberichte des SFB 21}, editor = {Krelle, Wilhelm}, publisher = {Verlag Chemie}, address = {Weinheim}, pages = {341 -- 367}, year = {1986}, language = {en} } @article{GroetschelLovaszSchrijver1986, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {Relaxations of Vertex Packing}, volume = {40}, journal = {Journal of Combinatorial Theory, Series B}, pages = {330 -- 343}, year = {1986}, language = {en} } @article{GroetschelPulleyblank1986, author = {Gr{\"o}tschel, Martin and Pulleyblank, William}, title = {Clique tree inequalities and the symmetric travelling salesman problem}, volume = {11}, journal = {Mathematics of Operations Research}, number = {4}, pages = {537 -- 569}, year = {1986}, language = {en} } @article{GroetschelHolland1987, author = {Gr{\"o}tschel, Martin and Holland, Olaf}, title = {A Cutting Plane Algorithm for Minimum Perfect 2-Matchings}, volume = {39}, journal = {Computing}, pages = {327 -- 344}, year = {1987}, language = {en} } @article{GroetschelThomassenWakabayashi1980, author = {Gr{\"o}tschel, Martin and Thomassen, Carsten and Wakabayashi, Yoshiko}, title = {Hypotraceable digraphs}, volume = {4}, journal = {Journal of Graph Theory}, pages = {377 -- 381}, year = {1980}, language = {en} } @article{GroetschelWakabayashi1980, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {Hypohamiltonian digraphs}, volume = {36}, journal = {Methods of Operations Research}, pages = {99 -- 119}, year = {1980}, language = {en} } @book{BachemButzGroetscheletal.1981, author = {Bachem, Achim and Butz, Lothar and Gr{\"o}tschel, Martin and (Bearb.), Rainer and Leitung), Bernhard}, title = {Input-Output-Analyse bei unternehmensgr{\"o}ßenspezifischen Fragestellungen}, publisher = {Institut f{\"u}r Mittelstandsforschung}, address = {Bonn}, year = {1981}, language = {en} } @article{BachemGroetschel1981, author = {Bachem, Achim and Gr{\"o}tschel, Martin}, title = {Homogenization of polyhedra}, volume = {40}, journal = {Methods of Operations Research}, pages = {215 -- 219}, year = {1981}, language = {en} } @inproceedings{BachemGroetschel1981, author = {Bachem, Achim and Gr{\"o}tschel, Martin}, title = {Characterizations of adjacency of faces of polyhedra}, volume = {14}, booktitle = {Mathematical Programming at Oberwolfach}, editor = {K{\"o}nig, Heinz and Korte, Bernhard and Ritter, Klaus}, publisher = {North-Holland}, pages = {1 -- 22}, year = {1981}, language = {en} } @article{GroetschelLovaszSchrijver1981, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {The ellipsoid method and its consequences in combinatorial optimization}, volume = {1}, journal = {Combinatorica}, number = {2}, pages = {169 -- 197}, year = {1981}, language = {en} } @article{GroetschelLovaszSchrijver1981, author = {Gr{\"o}tschel, Martin and Lov{\´a}sz, L{\´a}szlo and Schrijver, Alexander}, title = {The ellipsoid method and its consequences in combinatorial optimization}, journal = {IIASA Collab. Proceedings Ser. CP-81-S1}, pages = {511 -- 546}, year = {1981}, language = {en} } @article{GroetschelPulleyblank1981, author = {Gr{\"o}tschel, Martin and Pulleyblank, William}, title = {Weakly bipartite graphs and the max-cut problem}, volume = {1}, journal = {Operations Research Letters}, number = {1}, pages = {23 -- 27}, year = {1981}, language = {en} } @article{GroetschelWakabayashi1981, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {On the structure of the monotone asymmetric travelling salesman polytope I}, volume = {34}, journal = {Discrete Mathematics}, pages = {43 -- 59}, year = {1981}, language = {en} } @article{GroetschelWakabayashi1981, author = {Gr{\"o}tschel, Martin and Wakabayashi, Yoshiko}, title = {On the structure of the monotone asymmetric travelling salesman polytope II}, volume = {14}, journal = {Mathematical Programming Study}, pages = {77 -- 97}, year = {1981}, language = {en} } @inproceedings{BachemGroetschel1982, author = {Bachem, Achim and Gr{\"o}tschel, Martin}, title = {New aspects of polyhedral theory}, booktitle = {Modern Applied Mathematics}, editor = {Korte, Bernhard}, publisher = {North-Holland}, pages = {51 -- 106}, year = {1982}, language = {en} } @inproceedings{Groetschel1982, author = {Gr{\"o}tschel, Martin}, title = {Approaches to Hard Combinatorial Optimization Problems}, booktitle = {Modern Applied Mathematics, Optimization and Operations Research, Lect. Summer Sch., Bonn 1979}, editor = {Korte, Bernhard}, publisher = {North-Holland}, pages = {437 -- 515}, year = {1982}, language = {en} } @inproceedings{Groetschel1982, author = {Gr{\"o}tschel, Martin}, title = {Kombinatorische Optimierung}, booktitle = {Forschungsbericht 1978-1980 der Rheinischen Friedrich-Wilhelms-Universit{\"a}t}, editor = {der Universit{\"a}t Bonn, Der}, publisher = {Bouvier}, address = {Bonn}, pages = {45 -- 54}, year = {1982}, language = {en} } @inproceedings{Groetschel1984, author = {Gr{\"o}tschel, Martin}, title = {On Intersections of Longest Cycles}, booktitle = {Graph Theory and Combinatorics}, editor = {Bollob{\´a}s, B{\´e}la}, publisher = {Academic Press}, pages = {171 -- 189}, year = {1984}, language = {en} } @incollection{Groetschel1984, author = {Gr{\"o}tschel, Martin}, title = {Developments in combinatorial optimization}, booktitle = {Perspectives in Mathematics (Anniversary of Oberwolfach 1984)}, editor = {J{\"a}ger, Willi and Moser, J. and Remmert, R.}, publisher = {Birkh{\"a}user}, address = {Basel}, pages = {249 -- 294}, year = {1984}, language = {en} } @inproceedings{Groetschel1984, author = {Gr{\"o}tschel, Martin}, title = {Polyhedral Combinatorics}, booktitle = {COMBINATORIAL OPTIMIZATION}, editor = {O'Heigeartaigh, Michael and Lenstra, Jan and Kan, Alexander}, publisher = {Wiley}, pages = {1 -- 10}, year = {1984}, language = {en} } @techreport{Groetschel1984, author = {Gr{\"o}tschel, Martin}, title = {Polyedrische Kombinatorik und Schnittebenenverfahren}, number = {231}, publisher = {Forschungszentrum Graz, {\"O}sterreich}, year = {1984}, language = {en} } @article{GroetschelJuengerReinelt1984, author = {Gr{\"o}tschel, Martin and J{\"u}nger, Michael and Reinelt, Gerhard}, title = {A Cutting Plane Algorithm for the Linear Ordering Problem}, volume = {32}, journal = {Operations Research}, number = {6}, pages = {1195 -- 1220}, year = {1984}, language = {en} } @article{BorndoerferGroetschelPfetsch2007, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Pfetsch, Marc}, title = {A Column-Generation Approach to Line Planning in Public Transport}, volume = {41}, journal = {Transportation Science (INFORMS)}, number = {1}, doi = {10.1287/trsc.1060.0161}, pages = {123 -- 132}, year = {2007}, language = {en} } @misc{GroetschelLoebelVoelker1996, author = {Gr{\"o}tschel, Martin and L{\"o}bel, Andreas and V{\"o}lker, Manfred}, title = {Optimierung des Fahrzeugumlaufs im {\"O}ffentlichen Nahverkehr}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2195}, number = {SC-96-08}, year = {1996}, abstract = {This paper addresses the problem of scheduling vehicles in a public mass transportation system. We show how this problem can be modelled as a special multicommodity flow problem and outline the solution methodology we have developed. Based on polyhedral investigations, we have designed and implemented a branch\&cut algorithm and various heuristics with which real vehicle scheduling problems of truely large scale can be solved to optimality. We describe some implementation issues and report computational results.}, language = {de} } @misc{AscheuerFischettiGroetschel1997, author = {Ascheuer, Norbert and Fischetti, Matteo and Gr{\"o}tschel, Martin}, title = {A polyhedral study of the asymmetric travelling salesman problem with time windows}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2807}, number = {SC-97-11}, year = {1997}, abstract = {The asymmetric travelling salesman problem with time windows (ATSP-TW) is a basic model for scheduling and routing applications. In this paper we present a formulation of the problem involving only 0/1-variables associated with the arcs of the underlying digraph. This has the advantage of avoiding additional variables as well as the associated (typically very ineffective) linking constraints. In the formulation, time window restrictions are modelled by means of ``infeasible path elimination'' constraints. We present the basic form of these constraints along with some possible strengthenings. Several other classes of valid inequalities derived from related asymmetric travelling salesman problems are also described, along with a lifting theorem. We also study the ATSP-TW polytope, \$P_{TW}\$, defined as the convex hull of the integer solutions of our model. We show that determining the dimension of \$P_{TW}\$ is strongly {\em NP}--complete problem, even if only one time window is present. In this latter case, we provide a minimal equation system for \$P_{TW}\$. Computational experiments on the new formulation are reported in a companion paper [1997] where we show that it outperforms alternative formulations on some classes of problem instances.}, language = {en} } @misc{AlevrasGroetschelWessaely1997, author = {Alevras, Dimitris and Gr{\"o}tschel, Martin and Wess{\"a}ly, Roland}, title = {Cost-Efficient Network Synthesis from Leased Lines}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2912}, number = {SC-97-22}, year = {1997}, abstract = {Given a communication demand between each pair of nodes of a network we consider the problem of deciding what capacity to install on each edge of the network in order to minimize the building cost of the network and to satisfy the demand between each pair of nodes. The feasible capacities that can be leased from a network provider are of a particular kind in our case. There are a few so-called basic capacities having the property that every basic capacity is an integral multiple of every smaller basic capacity. An edge can be equipped with a capacity only if it is an integer combination of the basic capacities. We treat, in addition, several restrictions on the routings of the demands (length restriction, diversification) and failures of single nodes or single edges. We formulate the problem as a mixed integer linear programming problem and develop a cutting plane algorithm as well as several heuristics to solve it. We report on computational results for real world data.}, language = {en} } @misc{AlevrasGroetschelWessaely1997, author = {Alevras, Dimitris and Gr{\"o}tschel, Martin and Wess{\"a}ly, Roland}, title = {Capacity and Survivability Models for Telecommunication Networks}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2931}, number = {SC-97-24}, year = {1997}, abstract = {Designing low-cost networks that survive certain failure situations is one of the prime tasks in the telecommunication industry. In this paper we survey the development of models for network survivability used in practice in the last ten years. We show how algorithms integrating polyhedral combinatorics, linear programming, and various heuristic ideas can help solve real-world network dimensioning instances to optimality or within reasonable quality guarantees in acceptable running times. The most general problem type we address is the following. Let a communication demand between each pair of nodes of a telecommunication network be given. We consider the problem of choosing, among a discrete set of possible capacities, which capacity to install on each of the possible edges of the network in order to (i) satisfy all demands, (ii) minimize the building cost of the network. \noindent In addition to determining the network topology and the edge capacities we have to provide, for each demand, a routing such that (iii) no path can carry more than a given percentage of the demand, (iv) no path in the routing exceeds a given length. \noindent We also have to make sure that (v) for every single node or edge failure, a certain percentage of the demand is reroutable. \noindent Moreover, for all failure situations feasible routings must be computed. The model described above has been developed in cooperation with a German mobile phone provider. We present a mixed-integer programming formulation of this model and computational results with data from practice.}, language = {en} } @misc{DalitzGroetschelLuegger1997, author = {Dalitz, Wolfgang and Gr{\"o}tschel, Martin and L{\"u}gger, Joachim}, title = {Information Services for Mathematics in the Internet (Math-Net)}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2949}, number = {SC-97-25}, year = {1997}, abstract = {The present paper gives a brief description of the Math-Net project which is carried out by nine mathematical institutions in Germany, supported by Deutsches Forschungsnetz (DFN) and Deutsche Telekom. The project aims at setting up the technical and organizational infrastructure for efficient, inexpensive and user-driven information services for mathematics. With the aid of active (structured retrieval mechanisms) and passive (profile services) components, electronic mathematical information in Germany will be made available to the scientist at his workplace. The emphasis is put on information about publications, software and data collections, teaching and research activities, but also on organizational and bibliographical information. Decentral organization structures, distributed search systems as well as the use of meta-information (metadata) in accordance with the Dublin Core (hopefully) guarantee a longterm, high-quality repository of data. The well-known mathematical software and data collection netlib\/ will be used as an example to illustrate how such a collection can be adapted to Math-Net. An integration of netlib into HyperWave offers additional perspectives and functionalities.}, language = {en} } @misc{BorndoerferGroetschelHerzogetal.1996, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Herzog, Werner and Klostermeier, Fridolin and Konsek, Wilhelm and K{\"u}ttner, Christian}, title = {K{\"u}rzen muß nicht Kahlschlag heißen - das Beispiel Telebus-Behindertenfahrdienst Berlin}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2510}, number = {SC-96-41}, year = {1996}, abstract = {M{\"u}ssen Etatk{\"u}rzungen bei staatlichen Dienstleistungseinrichtungen notwendig zu Leistungseinschr{\"a}nkungen oder Geb{\"u}hrenerh{\"o}hungen f{\"u}hren? Wir zeigen am Beispiel des Berliner Behindertenfahrdienstes {\em Telebus}, da\ss{} Sparzwang auch als Chance zur Verbesserung der eigenen Verwaltungs- und Arbeitsabl{\"a}ufe genutzt werden kann. Durch st{\"a}rkere Dienstleistungsorientierung, Vereinfachung der Arbeitsabl{\"a}ufe und durch den Einsatz von moderner EDV und von mathematischen Optimierungsmethoden zur Fahrzeugeinsatzplanung werden bei Telebus heute staatliche Leistungen trotz geringeren Etats besser erbracht als vorher.}, language = {de} } @misc{AlevrasGroetschelJonasetal.1996, author = {Alevras, Dimitris and Gr{\"o}tschel, Martin and Jonas, Peter and Paul, Ulrich and Wess{\"a}ly, Roland}, title = {Survivable Mobile Phone Architectures: Models and Solution Methods}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2582}, number = {SC-96-48}, year = {1996}, abstract = {In the highly competitive area of telecommunications, cost, quality, and network management are among the most important aspects to be considered when designing a network. We study the problem of dimensioning a telecommunication network that is still operating in case of a failure of a network component. Given a demand between each pair of nodes of a telecommunication network and a finite set of possible capacities for each edge of the network, we consider the problem of deciding what capacity to install on each edge of the network in order to minimize the building cost of the network and to satisfy the demand between each pair of nodes, even if a network component fails. The routing of the demands must satisfy the following additional restrictions: (a) there is a maximum number of nodes allowed in each path between any pair of nodes (path length restriction), and (b) there is a maximum percentage of the demand between each pair of nodes that can be routed through any network component (diversification restriction). Moreover, the chosen capacities must be such that, for every single node or single edge failure, a certain percentage of the demand between any pair of nodes is reroutable (i.e. it ``survives'' the particular failure). We formulate the problem as a mixed integer linear programming problem and present a cutting plane algorithm as well as several heuristics for its solution. Furthermore, we discuss several ways to implement survivability into a telecommunication network.}, language = {en} } @misc{AlevrasGroetschelWessaely1996, author = {Alevras, Dimitris and Gr{\"o}tschel, Martin and Wess{\"a}ly, Roland}, title = {A Network Dimensioning Tool}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2591}, number = {SC-96-49}, year = {1996}, abstract = {Designing low cost networks that survive certain failure situations belongs to one of the prime tasks in the telecommunications industry. In this paper we describe a mathematical model combining several aspects of survivability that are elsewhere treated in a hierarchical fashion. We present mathematical investigations of this integrated model, a cutting plane algorithm, as well as several heuristics for its solution. Moreover, we report computational results with real world data. The problem we address is the following. Suppose, between each pair of nodes in a region, a communication demand is given. We want to determine the topology of a telecommunication network connecting the given nodes and to dimension all potential physical links. For each link, the possible capacities are restricted to a given finite set. The capacities must be chosen such that the communication demands are satisfied, even if certain network components fail, and such that the network building costs are as small as possible. Moreover, for each pair of nodes and each failure situation, we want to determine the paths on which the demand between the nodes is routed.}, language = {en} } @misc{BorndoerferGroetschelKlostermeieretal.1996, author = {Bornd{\"o}rfer, Ralf and Gr{\"o}tschel, Martin and Klostermeier, Fridolin and K{\"u}ttner, Christian}, title = {Telebus Berlin - Mobilit{\"a}t f{\"u}r Behinderte}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-2500}, number = {SC-96-40}, year = {1996}, abstract = {Steigendes Mobilit{\"a}tsbed{\"u}rfnis der Behinderten bei angespannter Haushaltslage --- diese Situation ergab vor drei Jahren beim Berliner Behindertenfahrdienst {\em Telebus\/} Handlungsbedarf. Gleichzeitig stie\ss{} die verwendete manuelle (Fahrzeug-)Tourenplanung mit damals etwa 1.000 Fahrtw{\"u}nschen pro Tag an ihre Grenzen. Zur L{\"o}sung dieser Probleme war der effiziente Einsatz von Computern und von {\em mathematischen Optimierungsverfahren\/} erforderlich. Ergebnis des daraufhin gestarteten {\em Telebus-Projektes\/} ist die Entwicklung eines neuen, alle Arbeitsabl{\"a}ufe unterst{\"u}tzenden Computersystems, das seit {\"u}ber einem Jahr im Einsatz ist. Herzst{\"u}ck dieses Systems ist ein auf mathematischen Methoden der ganzzahligen Optimierung basierendes Verfahren zur Tourenplanung. Ziel dieses Artikels ist die Beschreibung dieses Verfahrens und seiner Verwendung bei der Behindertenbef{\"o}rderung. Das Beispiel Telebus zeigt, da\ss{} der Einsatz mathematischer Optimierungstechniken neue M{\"o}glichkeiten f{\"u}r Kosteneinsparungen bei gleichzeitiger Serviceverbesserung auch in anderen Bereichen des {\"O}PNV er{\"o}ffnet.}, language = {de} }