TY - GEN A1 - Fügenschuh, Armin A1 - Geißler, Björn A1 - Gollmer, Ralf A1 - Hayn, Christine A1 - Henrion, Rene A1 - Hiller, Benjamin A1 - Humpola, Jesco A1 - Koch, Thorsten A1 - Lehmann, Thomas A1 - Martin, Alexander A1 - Mirkov, Radoslava A1 - Morsi, Antonio A1 - Römisch, Werner A1 - Rövekamp, Jessica A1 - Schewe, Lars A1 - Schmidt, Martin A1 - Schultz, Rüdiger A1 - Schwarz, Robert A1 - Schweiger, Jonas A1 - Stangl, Claudia A1 - Steinbach, Marc A1 - Willert, Bernhard T1 - Mathematical Optimization for Challenging Network Planning Problems in Unbundled Liberalized Gas Markets N2 - 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 where 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 show that these new paradigms lead to new and challenging mathematical optimization problems. In order to solve them and to provide meaningful results for practice, all aspects of the underlying problems, such as combinatorics, stochasticity, uncertainty, and nonlinearity, have to be addressed. With such special-tailored solvers, free network capacities and topological network extensions can, for instance, be determined. T3 - ZIB-Report - 13-13 KW - Gas Market Liberalization KW - Entry-Exit Model KW - Gas Network Access Regulation KW - Mixed-Integer Nonlinear Nonconvex Stochastic Optimization Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-17821 SN - 1438-0064 ER - TY - GEN A1 - Arnold, Thomas A1 - Berthold, Timo A1 - Heinz, Stefan A1 - Vigerske, Stefan A1 - Henrion, René A1 - Grötschel, Martin A1 - Koch, Thorsten A1 - Tischendorf, Caren A1 - Römisch, Werner ED - Deuflhard, Peter ED - Grötschel, Martin ED - Hömberg, Dietmar ED - Horst, Ulrich ED - Kramer, Jürg ED - Mehrmann, Volker ED - Polthier, Konrad ED - Schmidt, Frank ED - Schütte, Christof ED - Skutella, Martin ED - Sprekels, Jürgen T1 - A Jack of all Trades? Solving stochastic mixed-integer nonlinear constraint programs T2 - MATHEON - Mathematics for Key Technologies N2 - Natural gas is one of the most important energy sources in Germany and Europe. In recent years, political regulations have led to a strict separation of gas trading and gas transport, thereby assigning a central role in energy politics to the transportation and distribution of gas. These newly imposed political requirements influenced the technical processes of gas transport in such a way that the complex task of planning and operating gas networks has become even more intricate. Mathematically, the combination of discrete decisions on the configuration of a gas transport network, the nonlinear equations describing the physics of gas, and the uncertainty in demand and supply yield large-scale and highly complex stochastic mixed-integer nonlinear optimization problems. The Matheon project "Optimization of Gas Transport" takes the key role of making available the necessary core technology to solve the mathematical optimization problems which model the topology planning and the operation of gas networks. An important aspect of the academic impact is the free availability of our framework. As a result of several years of research and development, it is now possible to download a complete state-of-the-art framework for mixed-integer linear and nonlinear programming in source code at http://scip.zib.de Y1 - 2014 U6 - https://doi.org/10.4171/137 VL - 1 SP - 135 EP - 146 PB - European Mathematical Society ER - TY - JOUR A1 - Fügenschuh, Armin A1 - Geißler, Björn A1 - Gollmer, Ralf A1 - Hayn, Christine A1 - Henrion, René A1 - Hiller, Benjamin A1 - Humpola, Jesco A1 - Koch, Thorsten A1 - Lehmann, Thomas A1 - Martin, Alexander A1 - Mirkov, Radoslava A1 - Morsi, Antonio A1 - Römisch, Werner A1 - Rövekamp, Jessica A1 - Schewe, Lars A1 - Schmidt, Martin A1 - Schultz, Rüdiger A1 - Schwarz, Robert A1 - Schweiger, Jonas A1 - Stangl, Claudia A1 - Steinbach, Marc A1 - Willert, Bernhard T1 - Mathematical optimization for challenging network planning problems in unbundled liberalized gas markets JF - Energy Systems N2 - 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. Y1 - 2013 U6 - https://doi.org/10.1007/s12667-013-0099-8 VL - 5 IS - 3 SP - 449 EP - 473 PB - Springer Berlin Heidelberg CY - Berlin ER - TY - GEN A1 - Arnold, Thomas A1 - Berthold, Timo A1 - Heinz, Stefan A1 - Vigerske, Stefan A1 - Henrion, René A1 - Grötschel, Martin A1 - Koch, Thorsten A1 - Tischendorf, Caren A1 - Römisch, Werner T1 - A Jack of all Trades? Solving stochastic mixed-integer nonlinear constraint programs N2 - Natural gas is one of the most important energy sources in Germany and Europe. In recent years, political regulations have led to a strict separation of gas trading and gas transport, thereby assigning a central role in energy politics to the transportation and distribution of gas. These newly imposed political requirements influenced the technical processes of gas transport in such a way that the complex task of planning and operating gas networks has become even more intricate. Mathematically, the combination of discrete decisions on the configuration of a gas transport network, the nonlinear equations describing the physics of gas, and the uncertainty in demand and supply yield large-scale and highly complex stochastic mixed-integer nonlinear optimization problems. The Matheon project "Optimization of Gas Transport" takes the key role of making available the necessary core technology to solve the mathematical optimization problems which model the topology planning and the operation of gas networks. An important aspect of the academic impact is the free availability of our framework. As a result of several years of research and development, it is now possible to download a complete state-of-the-art framework for mixed-integer linear and nonlinear programming in source code at http://scip.zib.de T3 - ZIB-Report - 14-14 KW - gas transport optimization KW - mixed integer nonlinear programming Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-49947 SN - 1438-0064 ER - TY - GEN A1 - Tack, Alexander A1 - Kobayashi, Yuske A1 - Gauer, Tobias A1 - Schlaefer, Alexander A1 - Werner, René T1 - Bewegungsfeldschätzung in artefaktbehafteten 4D-CT-Bilddaten: Vergleich von paar- und gruppenweiser Registrierung T2 - 21st Annual Meeting of the German-Society-for-Radiation-Oncology N2 - In der Strahlentherapie von Lungentumoren kann mittels Dosisakkumulation der Einfluss von Atembewegungen auf statisch geplante Dosisverteilungen abgeschätzt werden. Grundlage sind 4D-CT-Daten des Patienten, aus denen mittels nicht-linearer Bildregistrierung eine Sequenz von Bewegungsfeldern berechnet wird. Typischerweise werden Methoden der paarweisen Bildregistrierung eingesetzt, d.h. konsekutiv zwei Atemphasen aufeinander registriert. Hierbei erfolgt i.d.R. eine physiologisch nicht plausible Anpassung der Felder an CT-Bewegungsartefakte. Gruppenweise Registrierungsansätze berücksichtigen hingegen gleichzeitig sämtliche Bilddaten des 4D-CT-Scans und ermöglichen die Integration von zeitlichen Konsistenzbetrachtungen. In diesem Beitrag wird der potentielle Vorteil der gruppen- im Vergleich zur paarweisen Registrierung in artefaktbehafteten 4D-CT-Daten untersucht. Y1 - 2015 U6 - https://doi.org/10.1007/s00066-015-0847-x VL - Supplement 1 SP - 65 EP - 65 PB - Springer CY - Strahlentherapie und Onkologie ET - 191 ER - TY - CHAP A1 - Tack, Alexander A1 - Kobayashi, Yuske A1 - Gauer, Tobias A1 - Schlaefer, Alexander A1 - Werner, René T1 - Groupwise Registration for Robust Motion Field Estimation in Artifact-Affected 4D CT Images T2 - ICART: Imaging and Computer Assistance in Radiation Therapy: A workshop held on Friday 9th October as part of MICCAI 2015 in Munich, Germany. MICCAI workshop. 2015. N2 - Precise voxel trajectory estimation in 4D CT images is a prerequisite for reliable dose accumulation during 4D treatment planning. 4D CT image data is, however, often affected by motion artifacts and applying standard pairwise registration to such data sets bears the risk of aligning anatomical structures to artifacts – with physiologically unrealistic trajectories being the consequence. In this work, the potential of a novel non-linear hybrid intensity- and feature-based groupwise registration method for robust motion field estimation in artifact-affected 4D CT image data is investigated. The overall registration performance is evaluated on the DIR-lab datasets; Its robustness if applied to artifact-affected data sets is analyzed using clinically acquired data sets with and without artifacts. The proposed registration approach achieves an accuracy comparable to the state-of-the-art (subvoxel accuracy), but smoother voxel trajectories compared to pairwise registration. Even more important: it maintained accuracy and trajectory smoothness in the presence of image artifacts – in contrast to standard pairwise registration, which yields higher landmark-based registration errors and a loss of trajectory smoothness when applied to artifact-affected data sets. Y1 - 2015 SP - 18 EP - 25 ER - TY - CHAP A1 - Hiller, Benjamin A1 - Hayn, Christine A1 - Heitsch, Holger A1 - Henrion, René A1 - Leövey, Hernan A1 - Möller, Andris A1 - Römisch, Werner T1 - Methods for verifying booked capacities T2 - Evaluating gas network capacities Y1 - 2015 SP - 291 EP - 315 PB - Society for Industrial and Applied Mathematics ER - TY - JOUR A1 - Koch, Thorsten A1 - Schmidt, Martin A1 - Hiller, Benjamin A1 - Pfetsch, Marc A1 - Geißler, Björn A1 - Henrion, René A1 - Joormann, Imke A1 - Martin, Alexander A1 - Morsi, Antonio A1 - Römisch, Werner A1 - Schewe, Lars A1 - Schultz, Rüdiger T1 - Capacity Evaluation for Large-Scale Gas Networks JF - German Success Stories in Industrial Mathematics Y1 - 2020 SN - 978-3-030-81454-0 U6 - https://doi.org/10.1007/978-3-030-81455-7 VL - 35 SP - 23 EP - 28 ER -