@inproceedings{VierhausFuegenschuh2015, author = {Vierhaus, Ingmar and F{\"u}genschuh, Armin}, title = {Global and Local Optimal Control of a Resource Utilization Problem}, booktitle = {Proceedings of the 33rd International Conference of the System Dynamics Society}, year = {2015}, abstract = {System Dynamic models describe physical, technical, economical, or social systems using differential and algebraic equations. In their purest form, these models are intended to describe the evolution of a system from a given initial state. In many applications, it is possible to intervene with the system in order to obtain a desired dynamic or a certain outcome in the end. On the mathematical side, this leads to control problems, where aside from the simulation one has to find optimal intervention functions over time that maximize a specific objective function. Using a dynamical model for the utilization of a natural nonrenewable resource of Behrens as a demonstrator example, we present two main mathematical solution strategies. They are distinguished by the quality certificate on their respective solution: one leads to proven local optimal solution, and the other technique yields proven global optimal solutions. We present implementational and numerical issues, and a comparison of both methods.}, language = {en} } @inproceedings{HillerSaitenmacherWalther2017, author = {Hiller, Benjamin and Saitenmacher, Ren{\´e} and Walther, Tom}, title = {Analysis of operating modes of complex compressor stations}, booktitle = {Proceedings of Operations Research 2016}, doi = {10.1007/978-3-319-55702-1_34}, pages = {251 -- 257}, year = {2017}, abstract = {We consider the modeling of operation modes for complex compressor stations (i.e., ones with several in- or outlets) in gas networks. In particular, we propose a refined model that allows to precompute tighter relaxations for each operation mode. These relaxations may be used to strengthen the compressor station submodels in gas network optimization problems. We provide a procedure to obtain the refined model from the input data for the original model.}, language = {en} } @masterthesis{Viernickel2016, type = {Bachelor Thesis}, author = {Viernickel, Jan Merlin}, title = {Absch{\"a}tzung der Suchbaumgr{\"o}ße und Laufzeit f{\"u}r Branch-and-Bound Algorithmen}, year = {2016}, language = {de} } @misc{Gottwald2016, type = {Master Thesis}, author = {Gottwald, Robert Lion}, title = {Experiments with Concurrency and Heuristics in SCIP}, year = {2016}, language = {en} }