@article{EveraersKarimiVarzanehFlecketal.2020,
  author    = {Everaers, Ralf and Karimi-Varzaneh, Hossein Ali and Fleck, Franz and Hojdis, Nils and Svaneborg, Carsten},
  title     = {Kremer-Grest Models for Commodity Polymer Melts: Linking Theory, Experiment, and Simulation at the Kuhn Scale},
  series = {Macromolecules},
  volume    = {53},
  journal   = {Macromolecules},
  number    = {6},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {1520-5835},
  doi       = {10.1021/acs.macromol.9b02428},
  pages     = {1901 -- 1916},
  year      = {2020},
  abstract  = {The Kremer-Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.},
  language  = {en}
}
@inproceedings{LorenzAltherrPelz2020,
  author    = {Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.},
  title     = {Assessing and Optimizing the Resilience of Water Distribution Systems Using Graph-Theoretical Metrics},
  series = {Operations Research Proceedings 2019},
  booktitle = {Operations Research Proceedings 2019},
  editor    = {Neufeld, Janis S. and Buscher, Udo and Lasch, Rainer and M{\"o}st, Dominik and Sch{\"o}nberger, J{\"o}rn},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-48439-2},
  doi       = {10.1007/978-3-030-48439-2_63},
  pages     = {521 -- 527},
  year      = {2020},
  abstract  = {Water distribution systems are an essential supply infrastructure for cities. Given that climatic and demographic influences will pose further challenges for these infrastructures in the future, the resilience of water supply systems, i.e. their ability to withstand and recover from disruptions, has recently become a subject of research. To assess the resilience of a WDS, different graph-theoretical approaches exist. Next to general metrics characterizing the network topology, also hydraulic and technical restrictions have to be taken into account. In this work, the resilience of an exemplary water distribution network of a major German city is assessed, and a Mixed-Integer Program is presented which allows to assess the impact of capacity adaptations on its resilience.},
  language  = {en}
}
@inproceedings{LeiseSimonAltherr2020,
  author    = {Leise, Philipp and Simon, Nicolai and Altherr, Lena},
  title     = {Comparison of Piecewise Linearization Techniques to Model Electric Motor Efficiency Maps: A Computational Study},
  series = {Operations Research Proceedings 2019},
  booktitle = {Operations Research Proceedings 2019},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-48439-2},
  doi       = {10.1007/978-3-030-48439-2_55},
  pages     = {457 -- 463},
  year      = {2020},
  abstract  = {To maximize the travel distances of battery electric vehicles such as cars or buses for a given amount of stored energy, their powertrains are optimized energetically. One key part within optimization models for electric powertrains is the efficiency map of the electric motor. The underlying function is usually highly nonlinear and nonconvex and leads to major challenges within a global optimization process. To enable faster solution times, one possibility is the usage of piecewise linearization techniques to approximate the nonlinear efficiency map with linear constraints. Therefore, we evaluate the influence of different piecewise linearization modeling techniques on the overall solution process and compare the solution time and accuracy for methods with and without explicitly used binary variables.},
  language  = {en}
}
@article{Olbertz2020,
  author    = {Olbertz, Klaus},
  title     = {Jahresr{\"u}ckblick Arbeitsrecht 2019 : Gesetzes{\"a}nderungen und insbesondere im Zeichen des Befristungs- und Urlaubsrechts stehende h{\"o}chstrichterliche Rechtsprechung},
  series = {NWB - Steuer- und Wirtschaftsrecht},
  journal   = {NWB - Steuer- und Wirtschaftsrecht},
  number    = {8},
  publisher = {NWB-Verl.},
  address   = {Herne},
  issn      = {0028-3460},
  pages     = {557 -- 569},
  year      = {2020},
  abstract  = {In Fortschreibung des Jahresr{\"u}ckblicks 2018 (Olbertz, NWB 5/2019 S. 266 ) skizziert der vorliegende Beitrag die j{\"u}ngsten nennenswerten Entwicklungen im Arbeitsrecht des Jahres 2019. Im Bereich der Gesetzgebung, mit dem sich der erste Teil des Beitrags befasst, betrifft dies etwa das Fachkr{\"a}fteeinwanderungsgesetz, die angestoßenen Schutzvorschriften f{\"u}r Whistleblower oder das gesetzlich verankerte Recht auf Br{\"u}ckenteilzeit. In der arbeitsrechtlichen h{\"o}chstrichterlichen Rechtsprechung stand das Jahr 2019 insbesondere im Zeichen des Befristungs- und des Urlaubsrechts. Was hier und dar{\"u}ber hinaus wegweisend war, zeigt der zweite Teil des Beitrags.},
  language  = {de}
}
@article{Olbertz2020,
  author    = {Olbertz, Klaus},
  title     = {GmbH-Gesch{\"a}ftsf{\"u}hrer: das eine Mal Arbeitnehmer, das andere Mal nicht : Arbeits- und sozialrechtliche Anwendung von Schutzvorschriften auf den Gesch{\"a}ftsf{\"u}hrer von A bis Z},
  series = {NWB - Steuer- und Wirtschaftsrecht},
  journal   = {NWB - Steuer- und Wirtschaftsrecht},
  number    = {19},
  publisher = {NWB-Verl.},
  address   = {Herne},
  issn      = {0028-3460},
  pages     = {1431 -- 1441},
  year      = {2020},
  language  = {de}
}
@article{Olbertz2020,
  author    = {Olbertz, Klaus},
  title     = {Wenn der „leitende" Angestellte doch nur ein „normaler" Arbeitnehmer ist ... : Zur Rechtsstellung leitender Angestellter, zu Fehleinsch{\"a}tzungen des Arbeitgebers und Praxishinweisen},
  series = {NWB - Steuer- und Wirtschaftsrecht},
  journal   = {NWB - Steuer- und Wirtschaftsrecht},
  number    = {32},
  publisher = {NWB-Verl.},
  address   = {Herne},
  issn      = {0028-3460},
  pages     = {2397 -- 2406},
  year      = {2020},
  language  = {de}
}
@book{Timme2020,
  author    = {Timme, Michael},
  title     = {WEG - Wohnungeigentumsgesetz / Hrsg. von Michael Timme . Stand 01.02.2020 ; Edition: 40},
  publisher = {Beck},
  address   = {M{\"u}nchen},
  year      = {2020},
  language  = {de}
}
@book{Timme2020,
  author    = {Timme, Michael},
  title     = {WEG - Wohnungeigentumsgesetz / Hrsg. von Michael Timme . Stand: 01.05.2020 ; Edition 41},
  publisher = {Beck},
  address   = {M{\"u}nchen},
  year      = {2020},
  language  = {de}
}
@inproceedings{MeckMuellerAltherretal.2020,
  author    = {Meck, Marvin M. and M{\"u}ller, Tim M. and Altherr, Lena and Pelz, Peter F.},
  title     = {Improving an industrial cooling system using MINLP, considering capital and operating costs},
  series = {Operations Research Proceedings 2019},
  booktitle = {Operations Research Proceedings 2019},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-48438-5 (Print)},
  doi       = {10.1007/978-3-030-48439-2_61},
  pages     = {505 -- 512},
  year      = {2020},
  abstract  = {The chemical industry is one of the most important industrial sectors in Germany in terms of manufacturing revenue. While thermodynamic boundary conditions often restrict the scope for reducing the energy consumption of core processes, secondary processes such as cooling offer scope for energy optimisation. In this contribution, we therefore model and optimise an existing cooling system. The technical boundary conditions of the model are provided by the operators, the German chemical company BASF SE. In order to systematically evaluate different degrees of freedom in topology and operation, we formulate and solve a Mixed-Integer Nonlinear Program (MINLP), and compare our optimisation results with the existing system.},
  language  = {en}
}
@article{MuellerLeiseLorenzetal.2020,
  author    = {M{\"u}ller, Tim M. and Leise, Philipp and Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.},
  title     = {Optimization and validation of pumping system design and operation for water supply in high-rise buildings},
  series = {Optimization and Engineering},
  volume    = {2021},
  journal   = {Optimization and Engineering},
  number    = {22},
  publisher = {Springer},
  issn      = {1573-2924},
  doi       = {10.1007/s11081-020-09553-4},
  pages     = {643 -- 686},
  year      = {2020},
  abstract  = {The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps' characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer's point of view, keeping in mind the economically important trade-off between investment and operation costs.},
  language  = {en}
}