@inproceedings{FerreinBharatheeshaSchifferetal.2019,
  author    = {Ferrein, Alexander and Bharatheesha, Mukunda and Schiffer, Stefan and Corbato, Carlos Hernandez},
  title     = {TRROS 2018 : Teaching Robotics with ROS Workshop at ERF 2018; Proceedings of the Workshop on Teaching Robotics with ROS (held at ERF 2018), co-located with European Robotics Forum 2018 (ERF 2018), Tampere, Finland, March 15th, 2018},
  series = {CEUR Workshop Proceedings},
  booktitle = {CEUR Workshop Proceedings},
  number    = {Vol-2329},
  issn      = {1613-0073},
  pages     = {68 Seiten},
  year      = {2019},
  language  = {en}
}
@article{SchoppBritunVoracetal.2019,
  author    = {Schopp, Christoph and Britun, Nikolay and Vorac, Jan and Synek, Petr and Snyders, Rony and Heuermann, Holger},
  title     = {Thermal and Optical Study on the Frequency Dependence of an Atmospheric Microwave Argon Plasma Jet},
  series = {IEEE Transactions on Plasma Science},
  volume    = {47},
  journal   = {IEEE Transactions on Plasma Science},
  number    = {7},
  publisher = {IEEE},
  address   = {New York},
  issn      = {1939-9375},
  pages     = {3176 -- 3181},
  year      = {2019},
  language  = {en}
}
@inproceedings{GaldiHartungDugelay2019,
  author    = {Galdi, Chiara and Hartung, Frank and Dugelay, Jean-Luc},
  title     = {Socrates: A database of realistic data for source camera recognition on smartphones},
  series = {Proceedings of the 8th International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM},
  booktitle = {Proceedings of the 8th International Conference on Pattern Recognition Applications and Methods - Volume 1: ICPRAM},
  isbn      = {978-989-758-351-3},
  doi       = {10.5220/0007403706480655},
  pages     = {648 -- 655},
  year      = {2019},
  language  = {en}
}
@incollection{RaoPathroseHueningetal.2019,
  author    = {Rao, Deepak and Pathrose, Plato and H{\"u}ning, Felix and Sid, Jithin},
  title     = {An Approach for Validating Safety of Perception Software in Autonomous Driving Systems},
  series = {Model-Based Safety and Assessment: 6th International Symposium, IMBSA 2019, Thessaloniki, Greece, October 16-18, 2019, Proceedings},
  booktitle = {Model-Based Safety and Assessment: 6th International Symposium, IMBSA 2019, Thessaloniki, Greece, October 16-18, 2019, Proceedings},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-32872-6},
  doi       = {10.1007/978-3-030-32872-6_20},
  pages     = {303 -- 316},
  year      = {2019},
  abstract  = {The increasing complexity of Advanced Driver Assistance Systems (ADAS) presents a challenging task to validate safe and reliable performance of these systems under varied conditions. The test and validation of ADAS/AD with real test drives, although important, involves huge costs and time. Simulation tools provide an alternative with the added advantage of reproducibility but often use ideal sensors, which do not reflect real sensor output accurately. This paper presents a new validation methodology using fault injection, as recommended by the ISO 26262 standard, to test software and system robustness. In our work, we investigated and developed a tool capable of inserting faults at different software and system levels to verify its robustness. The scope of this paper is to cover the fault injection test for the Visteon's DriveCore™ system, a centralized domain controller for Autonomous driving which is sensor agnostic and SoC agnostic. With this new approach, the validation of safety monitoring functionality and its behavior can be tested using real-world data instead of synthetic data from simulation tools resulting in having better confidence in system performance before proceeding with in-vehicle testing.},
  language  = {en}
}
@inproceedings{AlhwarinSchifferFerreinetal.2019,
  author    = {Alhwarin, Faraj and Schiffer, Stefan and Ferrein, Alexander and Scholl, Ingrid},
  title     = {An Optimized Method for 3D Body Scanning Applications Based on KinectFusion},
  series = {Communications in Computer and Information Science},
  volume    = {1024},
  booktitle = {Communications in Computer and Information Science},
  publisher = {Springer},
  issn      = {1865-0929},
  doi       = {10.1007/978-3-030-29196-9_6},
  pages     = {100 -- 113},
  year      = {2019},
  language  = {en}
}
@inproceedings{EltesterFerreinSchiffer2020,
  author    = {Eltester, Niklas Sebastian and Ferrein, Alexander and Schiffer, Stefan},
  title     = {A smart factory setup based on the RoboCup logistics league},
  series = {2020 IEEE Conference on Industrial Cyberphysical Systems (ICPS)},
  booktitle = {2020 IEEE Conference on Industrial Cyberphysical Systems (ICPS)},
  publisher = {IEEE},
  doi       = {10.1109/ICPS48405.2020.9274766},
  pages     = {297 -- 302},
  year      = {2020},
  abstract  = {In this paper we present SMART-FACTORY, a setup for a research and teaching facility in industrial robotics that is based on the RoboCup Logistics League. It is driven by the need for developing and applying solutions for digital production. Digitization receives constantly increasing attention in many areas, especially in industry. The common theme is to make things smart by using intelligent computer technology. Especially in the last decade there have been many attempts to improve existing processes in factories, for example, in production logistics, also with deploying cyber-physical systems. An initiative that explores challenges and opportunities for robots in such a setting is the RoboCup Logistics League. Since its foundation in 2012 it is an international effort for research and education in an intra-warehouse logistics scenario. During seven years of competition a lot of knowledge and experience regarding autonomous robots was gained. This knowledge and experience shall provide the basis for further research in challenges of future production. The focus of our SMART-FACTORY is to create a stimulating environment for research on logistics robotics, for teaching activities in computer science and electrical engineering programmes as well as for industrial users to study and explore the feasibility of future technologies. Building on a very successful history in the RoboCup Logistics League we aim to provide stakeholders with a dedicated facility oriented at their individual needs.},
  language  = {en}
}
@article{SerrorHackHenzeetal.2021,
  author    = {Serror, Martin and Hack, Sacha and Henze, Martin and Schuba, Marko and Wehrle, Klaus},
  title     = {Challenges and Opportunities in Securing the Industrial Internet of Things},
  series = {IEEE Transactions on Industrial Informatics},
  volume    = {17},
  journal   = {IEEE Transactions on Industrial Informatics},
  number    = {5},
  publisher = {IEEE},
  address   = {New York},
  issn      = {1941-0050},
  doi       = {10.1109/TII.2020.3023507},
  pages     = {2985 -- 2996},
  year      = {2021},
  language  = {en}
}
@inproceedings{CordesGligorevicBlicharski2019,
  author    = {Cordes, Sven and Gligorevic, Snjezana and Blicharski, Peter},
  title     = {Analysis of sine precision influence on DOA estimation using the MUSIC algorithm},
  series = {2019 20th International Radar Symposium (IRS)},
  booktitle = {2019 20th International Radar Symposium (IRS)},
  isbn      = {978-3-7369-9860-5},
  doi       = {10.23919/IRS.2019.8768162},
  pages     = {1 -- 10},
  year      = {2019},
  language  = {en}
}
@article{SchmidtForkmannSchultzetal.2019,
  author    = {Schmidt, Katharina and Forkmann, Katarina and Schultz, Heidrun and Gratz, Marcel and Bitz, Andreas and Wiech, Katja and Bingel, Ulrike},
  title     = {Enhanced Neural Reinstatement for Evoked Facial Pain Compared With Evoked Hand Pain},
  series = {The Journal of Pain},
  journal   = {The Journal of Pain},
  number    = {In Press, Corrected Proof},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1526-5900},
  doi       = {10.1016/j.jpain.2019.03.003},
  year      = {2019},
  language  = {en}
}
@article{KoenigWolf2018,
  author    = {K{\"o}nig, Johannes Alexander and Wolf, Martin},
  title     = {GHOST: An Evaluated Competence Developing Game for Cybersecurity Awareness Training},
  series = {International Journal on Advances in Security},
  volume    = {11},
  journal   = {International Journal on Advances in Security},
  number    = {3 \& 4},
  publisher = {IARIA Journals},
  issn      = {1942-2636},
  pages     = {274 -- 287},
  year      = {2018},
  abstract  = {To train end users how to interact with digital systems is indispensable to ensure a strong computer security. 'Competence Developing Game'-based approaches are particularly suitable for this purpose because of their motivation-and simulation-aspects. In this paper the Competence Developing Game 'GHOST' for cybersecurity awareness trainings and its underlying patterns are described. Accordingly, requirements for an 'Competence Developing Game' based training are discussed. Based on these requirements it is shown how a game can fulfill these requirements. A supplementary game interaction design and a corresponding evaluation study is shown. The combination of training requirements and interaction design is used to create a 'Competence Developing Game'-based training concept. A part of these concept is implemented into a playable prototype that serves around one hour of play respectively training time. This prototype is used to perform an evaluation of the game and training aspects of the awareness training. Thereby, the quality of the game aspect and the effectiveness of the training aspect are shown.},
  language  = {en}
}
@article{ClaerFerreinSchiffer2019,
  author    = {Claer, Mario and Ferrein, Alexander and Schiffer, Stefan},
  title     = {Calibration of a Rotating or Revolving Platform with a LiDAR Sensor},
  series = {Applied Sciences},
  volume    = {Volume 9},
  journal   = {Applied Sciences},
  number    = {issue 11, 2238},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3417},
  doi       = {10.3390/app9112238},
  pages     = {18 Seiten},
  year      = {2019},
  language  = {en}
}
@inproceedings{SteinbauerFerrein2019,
  author    = {Steinbauer, Gerald and Ferrein, Alexander},
  title     = {CogRob 2018 : Cognitive Robotics Workshop. Proceedings of the 11th Cognitive Robotics Workshop 2018 co-located with 16th International Conference on Principles of Knowledge Representation and Reasoning (KR 2018). Tempe, AZ, USA, October 27th, 2018.},
  series = {CEUR workshop proceedings},
  booktitle = {CEUR workshop proceedings},
  number    = {Vol-2325},
  issn      = {1613-0073},
  pages     = {46 Seiten},
  year      = {2019},
  language  = {en}
}
@inproceedings{SchifferBragard2019,
  author    = {Schiffer, Fabian and Bragard, Michael},
  title     = {Cascaded LQ and Field-Oriented Control of a Mobile Inverse Pendulum (Segway) with Permanent Magnet Synchronous Machines},
  series = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  booktitle = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  isbn      = {978-1-5386-9257-8},
  doi       = {10.1109/REM.2019.8744101},
  pages     = {1 -- 8},
  year      = {2019},
  language  = {en}
}
@inproceedings{BragardSubeSchneideretal.2019,
  author    = {Bragard, Michael and Sube, Maike and Schneider, Maike and Jungemann, Christoph},
  title     = {Introducing a Cross-University Bachelor's Programme with Orientation Semester - Enabling a Permeable Academic Education System},
  series = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  booktitle = {2019 20th International Conference on Research and Education in Mechatronics (REM)},
  isbn      = {978-1-5386-9257-8},
  doi       = {10.1109/REM.2019.8744132},
  pages     = {1 -- 6},
  year      = {2019},
  language  = {en}
}
@article{OrzadaSolbachGratzetal.2019,
  author    = {Orzada, Stephan and Solbach, Klaus and Gratz, Marcel and Brunheim, Sascha and Fiedler, Thomas M. and Johst, S{\"o}ren and Bitz, Andreas and Shooshtary, Samaneh and Abuelhaija, Asjraf and Voelker, Maximilian N. and Rietsch, Stefan H. G. and Kraff, Oliver and Maderwald, Stefan and Fl{\"o}ser, Martina and Oehmingen, Mark and Quick, Harald H. and Ladd, Mark E.},
  title     = {A 32-channel parallel transmit system add-on for 7T MRI},
  series = {Plos one},
  journal   = {Plos one},
  doi       = {10.1371/journal.pone.0222452},
  year      = {2019},
  language  = {en}
}
@article{NoureddineKraffLaddetal.2019,
  author    = {Noureddine, Yacine and Kraff, Oliver and Ladd, Mark E. and Wrede, Karsten and Chen, Bixia and Quick, Harald H. and Schaefers, Georg and Bitz, Andreas},
  title     = {Radiofrequency induced heating around aneurysm clips using a generic birdcage head coil at 7 Tesla under consideration of the minimum distance to decouple multiple aneurysm clips},
  series = {Magnetic Resonance in Medicine},
  journal   = {Magnetic Resonance in Medicine},
  number    = {Early view},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.27835},
  pages     = {1 -- 17},
  year      = {2019},
  language  = {en}
}
@article{OrzadaFiedlerBitzetal.2020,
  author    = {Orzada, Stephan and Fiedler, Thomas M. and Bitz, Andreas and Ladd, Mark E. and Quick, Harald H.},
  title     = {Local SAR compression with overestimation control to reduce maximum relative SAR overestimation and improve multi-channel RF array performance},
  series = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  journal   = {Magnetic Resonance Materials in Physics, Biology and Medicine},
  number    = {34 (2021)},
  publisher = {Springer},
  address   = {Heidelberg},
  isbn      = {1352-8661},
  doi       = {10.1007/s10334-020-00890-0},
  pages     = {153 -- 164},
  year      = {2020},
  abstract  = {Objective In local SAR compression algorithms, the overestimation is generally not linearly dependent on actual local SAR. This can lead to large relative overestimation at low actual SAR values, unnecessarily constraining transmit array performance. Method Two strategies are proposed to reduce maximum relative overestimation for a given number of VOPs. The first strategy uses an overestimation matrix that roughly approximates actual local SAR; the second strategy uses a small set of pre-calculated VOPs as the overestimation term for the compression. Result Comparison with a previous method shows that for a given maximum relative overestimation the number of VOPs can be reduced by around 20\% at the cost of a higher absolute overestimation at high actual local SAR values. Conclusion The proposed strategies outperform a previously published strategy and can improve the SAR compression where maximum relative overestimation constrains the performance of parallel transmission.},
  language  = {en}
}
@inproceedings{ChajanSchulteTiggesRekeetal.2021,
  author    = {Chajan, Eduard and Schulte-Tigges, Joschua and Reke, Michael and Ferrein, Alexander and Matheis, Dominik and Walter, Thomas},
  title     = {GPU based model-predictive path control for self-driving vehicles},
  series = {IEEE Intelligent Vehicles Symposium (IV)},
  booktitle = {IEEE Intelligent Vehicles Symposium (IV)},
  publisher = {IEEE},
  isbn      = {978-1-7281-5394-0},
  doi       = {10.1109/IV48863.2021.9575619},
  pages     = {1243 -- 1248},
  year      = {2021},
  abstract  = {One central challenge for self-driving cars is a proper path-planning. Once a trajectory has been found, the next challenge is to accurately and safely follow the precalculated path. The model-predictive controller (MPC) is a common approach for the lateral control of autonomous vehicles. The MPC uses a vehicle dynamics model to predict the future states of the vehicle for a given prediction horizon. However, in order to achieve real-time path control, the computational load is usually large, which leads to short prediction horizons. To deal with the computational load, the control algorithm can be parallelized on the graphics processing unit (GPU). In contrast to the widely used stochastic methods, in this paper we propose a deterministic approach based on grid search. Our approach focuses on systematically discovering the search area with different levels of granularity. To achieve this, we split the optimization algorithm into multiple iterations. The best sequence of each iteration is then used as an initial solution to the next iteration. The granularity increases, resulting in smooth and predictable steering angle sequences. We present a novel GPU-based algorithm and show its accuracy and realtime abilities with a number of real-world experiments.},
  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}
}
@book{Altherr2016,
  author    = {Altherr, Lena},
  title     = {Algorithmic System Design under Consideration of Dynamic Processes},
  publisher = {Shaker},
  address   = {Aachen},
  isbn      = {978-3-8440-4848-3},
  pages     = {94},
  year      = {2016},
  abstract  = {Nach Stand von Wissenschaft und Technik werden Komponenten hinsichtlich ihrer Eigenschaften, wie Lebensdauer oder Energieeffizienz, optimiert. Allerdings k{\"o}nnen selbst hervorragende Komponenten zu ineffizienten oder instabilen Systemen f{\"u}hren, wenn ihr Zusammenspiel nur unzureichend ber{\"u}cksichtigt wird. Eine Systembetrachtung schafft ein gr{\"o}ßeres Optimierungspotential - dem erh{\"o}hten Potential steht jedoch auch ein erh{\"o}hter Komplexit{\"a}tsgrad gegen{\"u}ber. Die vorliegende Arbeit ist im Rahmen des Sonderforschungsbereichs 805 entstanden, dessen Ziel die Beherrschung von Unsicherheit in Systemen des Maschinenbaus ist. Die Arbeit zeigt anhand eines realen Systems aus dem Bereich der Hydraulik, wie Unsicherheit in der Entwicklungsphase beherrscht werden kann. Hierbei ist neu, dass die durch den sp{\"a}teren Betrieb zu erwartende Systemdegradation eines jeden m{\"o}glichen Systemvorschlags antizipiert werden kann. Dadurch k{\"o}nnen Betriebs- und Wartungskosten vorausgesagt und minimiert werden und durch eine optimale Betriebs- und Wartungsstrategie die Verf{\"u}gbarkeit des Systems garantiert werden. Wesentliche Fragen bei der optimalen Auslegung des betrachteten hydrostatischen Getriebes sind dessen physikalische Modellierung, die Darstellung des Optimierungsproblems als gemischt-ganzzahliges lineares Programm, und dessen algorithmische Behandlung zur L{\"o}sungsfindung. Hierzu werden Heuristiken zum schnelleren Auffinden sinnvoller Systemtopologien vorgestellt und mittels mathematischer Dekomposition eine Bewertung des dynamischen Verschleiß- und Wartungsverlaufs m{\"o}glicher Systemvorschl{\"a}ge vorgenommen. Die Arbeit stellt die Optimierung technischer Systeme an der Schnittstelle von Mathematik, Informatik und Ingenieurwesen sowohl gr{\"u}ndlich als auch anschaulich und nachvollziehbar dar.},
  language  = {en}
}
@incollection{AltherrEdererLorenzetal.2016,
  author    = {Altherr, Lena and Ederer, Thorsten and Lorenz, Ulf and Pelz, Peter F. and P{\"o}ttgen, Philipp},
  title     = {Designing a feedback control system via mixed-integer programming},
  series = {Operations Research Proceedings 2014: Selected Papers of the Annual International Conference of the German Operations Research},
  booktitle = {Operations Research Proceedings 2014: Selected Papers of the Annual International Conference of the German Operations Research},
  editor    = {L{\"u}bbecke, Marco E. and Koster, Arie and Letmathe, Peter and Madlener, Reihard and Preis, Britta and Walther, Grit},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-28695-2},
  doi       = {10.1007/978-3-319-28697-6_18},
  pages     = {121 -- 127},
  year      = {2016},
  abstract  = {Pure analytical or experimental methods can only find a control strategy for technical systems with a fixed setup. In former contributions we presented an approach that simultaneously finds the optimal topology and the optimal open-loop control of a system via Mixed Integer Linear Programming (MILP). In order to extend this approach by a closed-loop control we present a Mixed Integer Program for a time discretized tank level control. This model is the basis for an extension by combinatorial decisions and thus for the variation of the network topology. Furthermore, one is able to appraise feasible solutions using the global optimality gap.},
  language  = {en}
}
@incollection{PfetschAbeleAltherretal.2021,
  author    = {Pfetsch, Marc E. and Abele, Eberhard and Altherr, Lena and B{\"o}lling, Christian and Br{\"o}tz, Nicolas and Dietrich, Ingo and Gally, Tristan and Geßner, Felix and Groche, Peter and Hoppe, Florian and Kirchner, Eckhard and Kloberdanz, Hermann and Knoll, Maximilian and Kolvenbach, Philip and Kuttich-Meinlschmidt, Anja and Leise, Philipp and Lorenz, Ulf and Matei, Alexander and Molitor, Dirk A. and Niessen, Pia and Pelz, Peter F. and Rexer, Manuel and Schmitt, Andreas and Schmitt, Johann M. and Schulte, Fiona and Ulbrich, Stefan and Weigold, Matthias},
  title     = {Strategies for mastering uncertainty},
  series = {Mastering uncertainty in mechanical engineering},
  booktitle = {Mastering uncertainty in mechanical engineering},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-78353-2},
  doi       = {10.1007/978-3-030-78354-9_6},
  pages     = {365 -- 456},
  year      = {2021},
  abstract  = {This chapter describes three general strategies to master uncertainty in technical systems: robustness, flexibility and resilience. It builds on the previous chapters about methods to analyse and identify uncertainty and may rely on the availability of technologies for particular systems, such as active components. Robustness aims for the design of technical systems that are insensitive to anticipated uncertainties. Flexibility increases the ability of a system to work under different situations. Resilience extends this characteristic by requiring a given minimal functional performance, even after disturbances or failure of system components, and it may incorporate recovery. The three strategies are described and discussed in turn. Moreover, they are demonstrated on specific technical systems.},
  language  = {en}
}
@inproceedings{MuellerSchmittLeiseetal.2021,
  author    = {M{\"u}ller, Tim M. and Schmitt, Andreas and Leise, Philipp and Meck, Tobias and Altherr, Lena and Pelz, Peter F. and Pfetsch, Marc E.},
  title     = {Validation of an optimized resilient water supply system},
  series = {Uncertainty in Mechanical Engineering},
  booktitle = {Uncertainty in Mechanical Engineering},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-77255-0},
  doi       = {10.1007/978-3-030-77256-7_7},
  pages     = {70 -- 80},
  year      = {2021},
  abstract  = {Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.},
  language  = {en}
}
@incollection{LeiseAltherrSimonetal.2019,
  author    = {Leise, Philipp and Altherr, Lena and Simon, Nicolai and Pelz, Peter F.},
  title     = {Finding global-optimal gearbox designs for battery electric vehicles},
  series = {Optimization of complex systems - theory, models, algorithms and applications : WCGO 2019},
  booktitle = {Optimization of complex systems - theory, models, algorithms and applications : WCGO 2019},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-21802-7},
  doi       = {10.1007/978-3-030-21803-4_91},
  pages     = {916 -- 925},
  year      = {2019},
  abstract  = {In order to maximize the possible travel distance of battery electric vehicles with one battery charge, it is mandatory to adjust all components of the powertrain carefully to each other. While current vehicle designs mostly simplify the powertrain rigorously and use an electric motor in combination with a gearbox with only one fixed transmission ratio, the use of multi-gear systems has great potential. First, a multi-speed system is able to improve the overall energy efficiency. Secondly, it is able to reduce the maximum momentum and therefore to reduce the maximum current provided by the traction battery, which results in a longer battery lifetime. In this paper, we present a systematic way to generate multi-gear gearbox designs that—combined with a certain electric motor—lead to the most efficient fulfillment of predefined load scenarios and are at the same time robust to uncertainties in the load. Therefore, we model the electric motor and the gearbox within a Mixed-Integer Nonlinear Program, and optimize the efficiency of the mechanical parts of the powertrain. By combining this mathematical optimization program with an unsupervised machine learning algorithm, we are able to derive global-optimal gearbox designs for practically relevant momentum and speed requirements.},
  language  = {en}
}
@incollection{StengerAltherrAbel2019,
  author    = {Stenger, David and Altherr, Lena and Abel, Dirk},
  title     = {Machine learning and metaheuristics for black-box optimization of product families: a case-study investigating solution quality vs. computational overhead},
  series = {Operations Research Proceedings 2018},
  booktitle = {Operations Research Proceedings 2018},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-18499-5 (Print)},
  doi       = {10.1007/978-3-030-18500-8_47},
  pages     = {379 -- 385},
  year      = {2019},
  abstract  = {In product development, numerous design decisions have to be made. Multi-domain virtual prototyping provides a variety of tools to assess technical feasibility of design options, however often requires substantial computational effort for just a single evaluation. A special challenge is therefore the optimal design of product families, which consist of a group of products derived from a common platform. Finding an optimal platform configuration (stating what is shared and what is individually designed for each product) and an optimal design of all products simultaneously leads to a mixed-integer nonlinear black-box optimization model. We present an optimization approach based on metamodels and a metaheuristic. To increase computational efficiency and solution quality, we compare different types of Gaussian process regression metamodels adapted from the domain of machine learning, and combine them with a genetic algorithm. We illustrate our approach on the example of a product family of electrical drives, and investigate the trade-off between solution quality and computational overhead.},
  language  = {en}
}
@article{RauschFriesenAltherretal.2018,
  author    = {Rausch, Lea and Friesen, John and Altherr, Lena and Meck, Marvin and Pelz, Peter F.},
  title     = {A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data},
  series = {Remote Sensing},
  volume    = {10},
  journal   = {Remote Sensing},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  isbn      = {2072-4292},
  doi       = {10.3390/rs10020216},
  pages     = {1 -- 23},
  year      = {2018},
  abstract  = {Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.},
  language  = {en}
}
@inproceedings{MuellerAltherrAholaetal.2019,
  author    = {M{\"u}ller, Tim M. and Altherr, Lena and Ahola, Marja and Schabel, Samuel and Pelz, Peter F.},
  title     = {Multi-Criteria optimization of pressure screen systems in paper recycling - balancing quality, yield, energy consumption and system complexity},
  series = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  booktitle = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  editor    = {Rodrigues, H. C.},
  publisher = {Springer International Publishing},
  address   = {Basel},
  isbn      = {978-3-319-97773-7},
  doi       = {10.1007/978-3-319-97773-7_105},
  year      = {2019},
  abstract  = {The paper industry is the industry with the third highest energy consumption in the European Union. Using recycled paper instead of fresh fibers for papermaking is less energy consuming and saves resources. However, adhesive contaminants in recycled paper are particularly problematic since they reduce the quality of the resulting paper-product. To remove as many contaminants and at the same time obtain as many valuable fibres as possible, fine screening systems, consisting of multiple interconnected pressure screens, are used. Choosing the best configuration is a non-trivial task: The screens can be interconnected in several ways, and suitable screen designs as well as operational parameters have to be selected. Additionally, one has to face conflicting objectives. In this paper, we present an approach for the multi-criteria optimization of pressure screen systems based on Mixed-Integer Nonlinear Programming. We specifically focus on a clear representation of the trade-off between different objectives.},
  language  = {en}
}
@article{AltherrJoggerstLeiseetal.2018,
  author    = {Altherr, Lena and Joggerst, Laura and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas and Wendt, Janine},
  title     = {On obligations in the development process of resilient systems with algorithmic design methods},
  series = {Applied Mechanics and Materials},
  volume    = {885},
  journal   = {Applied Mechanics and Materials},
  number    = {885},
  publisher = {Trans Tech Publications},
  address   = {B{\"a}ch},
  isbn      = {1662-7482},
  doi       = {10.4028/www.scientific.net/AMM.885.240},
  pages     = {240 -- 252},
  year      = {2018},
  abstract  = {Advanced computational methods are needed both for the design of large systems and to compute high accuracy solutions. Such methods are efficient in computation, but the validation of results is very complex, and highly skilled auditors are needed to verify them. We investigate legal questions concerning obligations in the development phase, especially for technical systems developed using advanced methods. In particular, we consider methods of resilient and robust optimization. With these techniques, high performance solutions can be found, despite a high variety of input parameters. However, given the novelty of these methods, it is uncertain whether legal obligations are being met. The aim of this paper is to discuss if and how the choice of a specific computational method affects the developer's product liability. The review of legal obligations in this paper is based on German law and focuses on the requirements that must be met during the design and development process.},
  language  = {en}
}
@article{SunAltherrPeietal.2018,
  author    = {Sun, Hui and Altherr, Lena and Pei, Ji and Pelz, Peter F. and Yuan, Shouqi},
  title     = {Optimal booster station design and operation under uncertain load},
  series = {Applied Mechanics and Materials},
  volume    = {885},
  journal   = {Applied Mechanics and Materials},
  publisher = {Trans Tech Publications},
  address   = {B{\"a}ch},
  issn      = {1662-7482},
  doi       = {10.4028/www.scientific.net/AMM.885.102},
  pages     = {102 -- 115},
  year      = {2018},
  abstract  = {Given industrial applications, the costs for the operation and maintenance of a pump system typically far exceed its purchase price. For finding an optimal pump configuration which minimizes not only investment, but life-cycle costs, methods like Technical Operations Research which is based on Mixed-Integer Programming can be applied. However, during the planning phase, the designer is often faced with uncertain input data, e.g. future load demands can only be estimated. In this work, we deal with this uncertainty by developing a chance-constrained two-stage (CCTS) stochastic program. The design and operation of a booster station working under uncertain load demand are optimized to minimize total cost including purchase price, operation cost incurred by energy consumption and penalty cost resulting from water shortage. We find optimized system layouts using a sample average approximation (SAA) algorithm, and analyze the results for different risk levels of water shortage. By adjusting the risk level, the costs and performance range of the system can be balanced, and thus the system's resilience can be engineered},
  language  = {en}
}
@incollection{MuellerAltherrAholaetal.2018,
  author    = {M{\"u}ller, Tim M. and Altherr, Lena and Ahola, Marja and Schabel, Samuel and Pelz, Peter F.},
  title     = {Optimizing pressure screen systems in paper recycling: optimal system layout, component selection and operation},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-18499-5},
  doi       = {10.1007/978-3-030-18500-8_44},
  pages     = {355 -- 361},
  year      = {2018},
  abstract  = {Around 60\% of the paper worldwide is made from recovered paper. Especially adhesive contaminants, so called stickies, reduce paper quality. To remove stickies but at the same time keep as many valuable fibers as possible, multi-stage screening systems with several interconnected pressure screens are used. When planning such systems, suitable screens have to be selected and their interconnection as well as operational parameters have to be defined considering multiple conflicting objectives. In this contribution, we present a Mixed-Integer Nonlinear Program to optimize system layout, component selection and operation to find a suitable trade-off between output quality and yield.},
  language  = {en}
}
@inproceedings{Huening2021,
  author    = {H{\"u}ning, Felix},
  title     = {Sustainable changes beyond covid-19 for a second semester physics course for electrical engineering students},
  series = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?},
  booktitle = {Blended Learning in Engineering Education: challenging, enlightening - and lasting?},
  isbn      = {978-2-87352-023-6},
  pages     = {1405 -- 1409},
  year      = {2021},
  abstract  = {The course Physics for Electrical Engineering is part of the curriculum of the bachelor program Electrical Engineering at University of Applied Science Aachen. Before covid-19 the course was conducted in a rather traditional way with all parts (lecture, exercise and lab) face-to-face. This teaching approach changed fundamentally within a week when the covid-19 limitations forced all courses to distance learning. All parts of the course were transformed to pure distance learning including synchronous and asynchronous parts for the lecture, live online-sessions for the exercises and self-paced labs at home. Using these methods, the course was able to impart the required knowledge and competencies. Taking the teacher's observations of the student's learning behaviour and engagement, the formal and informal feedback of the students and the results of the exams into account, the new methods are evaluated with respect to effectiveness, sustainability and suitability for competence transfer. Based on this analysis strong and weak points of the concept and countermeasures to solve the weak points were identified. The analysis further leads to a sustainable teaching approach combining synchronous and asynchronous parts with self-paced learning times that can be used in a very flexible manner for different learning scenarios, pure online, hybrid (mixture of online and presence times) and pure presence teaching.},
  language  = {en}
}
@article{LeiseEsserEichenlaubetal.2021,
  author    = {Leise, Philipp and Eßer, Arved and Eichenlaub, Tobias and Schleiffer, Jean-Eric and Altherr, Lena and Rinderknecht, Stephan and Pelz, Peter F.},
  title     = {Sustainable system design of electric powertrains - comparison of optimization methods},
  series = {Engineering Optimization},
  journal   = {Engineering Optimization},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {0305-215X},
  doi       = {10.1080/0305215X.2021.1928660},
  year      = {2021},
  abstract  = {The transition within transportation towards battery electric vehicles can lead to a more sustainable future. To account for the development goal 'climate action' stated by the United Nations, it is mandatory, within the conceptual design phase, to derive energy-efficient system designs. One barrier is the uncertainty of the driving behaviour within the usage phase. This uncertainty is often addressed by using a stochastic synthesis process to derive representative driving cycles and by using cycle-based optimization. To deal with this uncertainty, a new approach based on a stochastic optimization program is presented. This leads to an optimization model that is solved with an exact solver. It is compared to a system design approach based on driving cycles and a genetic algorithm solver. Both approaches are applied to find efficient electric powertrains with fixed-speed and multi-speed transmissions. Hence, the similarities, differences and respective advantages of each optimization procedure are discussed.},
  language  = {en}
}
@inproceedings{LeiseBreuerAltherretal.2020,
  author    = {Leise, Philipp and Breuer, Tim and Altherr, Lena and Pelz, Peter F.},
  title     = {Development, validation and assessment of a resilient pumping system},
  series = {Proceedings of the Joint International Resilience Conference, JIRC2020},
  booktitle = {Proceedings of the Joint International Resilience Conference, JIRC2020},
  isbn      = {978-90-365-5095-6},
  pages     = {97 -- 100},
  year      = {2020},
  abstract  = {The development of resilient technical systems is a challenging task, as the system should adapt automatically to unknown disturbances and component failures. To evaluate different approaches for deriving resilient technical system designs, we developed a modular test rig that is based on a pumping system. On the basis of this example system, we present metrics to quantify resilience and an algorithmic approach to improve resilience. This approach enables the pumping system to automatically react on unknown disturbances and to reduce the impact of component failures. In this case, the system is able to automatically adapt its topology by activating additional valves. This enables the system to still reach a minimum performance, even in case of failures. Furthermore, timedependent disturbances are evaluated continuously, deviations from the original state are automatically detected and anticipated in the future. This allows to reduce the impact of future disturbances and leads to a more resilient system behaviour.},
  language  = {en}
}
@inproceedings{LorenzAltherrPelz2019,
  author    = {Lorenz, Imke-Sophie B. and Altherr, Lena and Pelz, Peter F.},
  title     = {Graph-theoretic resilience analysis of a water distribution system's topology},
  series = {World Congress on Resilience, Reliability and Asset Management 2019},
  booktitle = {World Congress on Resilience, Reliability and Asset Management 2019},
  pages     = {106 -- 109},
  year      = {2019},
  abstract  = {Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. In practice, the focus is set on the most beneficial maintenance measures and/or capacity adaptations of existing water distribution systems (WDS). Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of WDS, i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, metrics based on graph theory have been proposed. In this study, a promising approach is applied to assess the resilience of the WDS for a district in a major German City. The conducted analysis provides insight into the process of actively influencing the resilience of WDS},
  language  = {en}
}
@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}
}
@inproceedings{MuellerAltherrLeiseetal.2020,
  author    = {M{\"u}ller, Tim M. and Altherr, Lena and Leise, Philipp and Pelz, Peter F.},
  title     = {Optimization of pumping systems for buildings: Experimental validation of different degrees of model detail on a modular test rig},
  series = {Operations Research Proceedings 2019},
  booktitle = {Operations Research Proceedings 2019},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-48438-5},
  doi       = {10.1007/978-3-030-48439-2_58},
  pages     = {481 -- 488},
  year      = {2020},
  abstract  = {Successful optimization requires an appropriate model of the system under consideration. When selecting a suitable level of detail, one has to consider solution quality as well as the computational and implementation effort. In this paper, we present a MINLP for a pumping system for the drinking water supply of high-rise buildings. We investigate the influence of the granularity of the underlying physical models on the solution quality. Therefore, we model the system with a varying level of detail regarding the friction losses, and conduct an experimental validation of our model on a modular test rig. Furthermore, we investigate the computational effort and show that it can be reduced by the integration of domain-specific knowledge.},
  language  = {en}
}
@article{AltherrLeisePfetschetal.2018,
  author    = {Altherr, Lena and Leise, Philipp and Pfetsch, Marc E. and Schmitt, Andreas},
  title     = {Algorithmic design and resilience assessment of energy efficient high-rise water supply systems},
  series = {Applied Mechanics and Materials},
  volume    = {885},
  journal   = {Applied Mechanics and Materials},
  publisher = {Trans Tech Publications},
  address   = {B{\"a}ch},
  issn      = {1662-7482},
  doi       = {10.4028/www.scientific.net/AMM.885.211},
  pages     = {211 -- 223},
  year      = {2018},
  abstract  = {High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building.},
  language  = {en}
}
@inproceedings{LeiseAltherr2018,
  author    = {Leise, Philipp and Altherr, Lena},
  title     = {Optimizing the design and control of decentralized water supply systems - a case-study of a hotel building},
  series = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  booktitle = {EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-97773-7},
  doi       = {10.1007/978-3-319-97773-7_107},
  pages     = {1241 -- 1252},
  year      = {2018},
  abstract  = {To increase pressure to supply all floors of high buildings with water, booster stations, normally consisting of several parallel pumps in the basement, are used. In this work, we demonstrate the potential of a decentralized pump topology regarding energy savings in water supply systems of skyscrapers. We present an approach, based on Mixed-Integer Nonlinear Programming, that allows to choose an optimal network topology and optimal pumps from a predefined construction kit comprising different pump types. Using domain-specific scaling laws and Latin Hypercube Sampling, we generate different input sets of pump types and compare their impact on the efficiency and cost of the total system design. As a realistic application example, we consider a hotel building with 325 rooms, 12 floors and up to four pressure zones.},
  language  = {en}
}
@incollection{StengerAltherrMuelleretal.2018,
  author    = {Stenger, David and Altherr, Lena and M{\"u}ller, Tankred and Pelz, Peter F.},
  title     = {Product family design optimization using model-based engineering techniques},
  series = {Operations Research Proceedings 2017},
  booktitle = {Operations Research Proceedings 2017},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-89919-0},
  doi       = {10.1007/978-3-319-89920-6_66},
  pages     = {495 -- 502},
  year      = {2018},
  abstract  = {Highly competitive markets paired with tremendous production volumes demand particularly cost efficient products. The usage of common parts and modules across product families can potentially reduce production costs. Yet, increasing commonality typically results in overdesign of individual products. Multi domain virtual prototyping enables designers to evaluate costs and technical feasibility of different single product designs at reasonable computational effort in early design phases. However, savings by platform commonality are hard to quantify and require detailed knowledge of e.g. the production process and the supply chain. Therefore, we present and evaluate a multi-objective metamodel-based optimization algorithm which enables designers to explore the trade-off between high commonality and cost optimal design of single products.},
  language  = {en}
}
@article{AltherrBroetzDietrichetal.2018,
  author    = {Altherr, Lena and Br{\"o}tz, Nicolas and Dietrich, Ingo and Gally, Tristan and Geßner, Felix and Kloberdanz, Hermann and Leise, Philipp and Pelz, Peter Franz and Schlemmer, Pia and Schmitt, Andreas},
  title     = {Resilience in mechanical engineering - a concept for controlling uncertainty during design, production and usage phase of load-carrying structures},
  series = {Applied Mechanics and Materials},
  volume    = {885},
  journal   = {Applied Mechanics and Materials},
  publisher = {Trans Tech Publications},
  address   = {B{\"a}ch},
  isbn      = {1662-7482},
  doi       = {10.4028/www.scientific.net/AMM.885.187},
  pages     = {187 -- 198},
  year      = {2018},
  abstract  = {Resilience as a concept has found its way into different disciplines to describe the ability of an individual or system to withstand and adapt to changes in its environment. In this paper, we provide an overview of the concept in different communities and extend it to the area of mechanical engineering. Furthermore, we present metrics to measure resilience in technical systems and illustrate them by applying them to load-carrying structures. By giving application examples from the Collaborative Research Centre (CRC) 805, we show how the concept of resilience can be used to control uncertainty during different stages of product life.},
  language  = {en}
}
@inproceedings{LeiseAltherrPelz2018,
  author    = {Leise, Philipp and Altherr, Lena and Pelz, Peter F.},
  title     = {Technical Operations Research (TOR) - Algorithms, not Engineers, Design Optimal Energy Efficient and Resilient Cooling Systems},
  series = {FAN2018 - Proceedings of the International Conference on Fan Noise, Aerodynamics, Applications and Systems},
  booktitle = {FAN2018 - Proceedings of the International Conference on Fan Noise, Aerodynamics, Applications and Systems},
  pages     = {1 -- 12},
  year      = {2018},
  abstract  = {The overall energy efficiency of ventilation systems can be improved by considering not only single components, but by considering as well the interplay between every part of the system. With the help of the method "TOR" ("Technical Operations Research"), which was developed at the Chair of Fluid Systems at TU Darmstadt, it is possible to improve the energy efficiency of the whole system by considering all possible design choices programmatically. We show the ability of this systematic design approach with a ventilation system for buildings as a use case example. Based on a Mixed-Integer Nonlinear Program (MINLP) we model the ventilation system. We use binary variables to model the selection of different pipe diameters. Multiple fans are model with the help of scaling laws. The whole system is represented by a graph, where the edges represent the pipes and fans and the nodes represents the source of air for cooling and the sinks, that have to be cooled. At the beginning, the human designer chooses a construction kit of different suitable fans and pipes of different diameters and different load cases. These boundary conditions define a variety of different possible system topologies. It is not possible to consider all topologies by hand. With the help of state of the art solvers, on the other side, it is possible to solve this MINLP. Next to this, we also consider the effects of malfunctions in different components. Therefore, we show a first approach to measure the resilience of the shown example use case. Further, we compare the conventional approach with designs that are more resilient. These more resilient designs are derived by extending the before mentioned model with further constraints, that consider explicitly the resilience of the overall system. We show that it is possible to design resilient systems with this method already in the early design stage and compare the energy efficiency and resilience of these different system designs.},
  language  = {en}
}
@incollection{AltherrDoerigEdereretal.2017,
  author    = {Altherr, Lena and D{\"o}rig, Bastian and Ederer, Thorsten and Pelz, Peter Franz and Pfetsch, Marc and Wolf, Jan},
  title     = {A mixed-integer nonlinear program for the design of gearboxes},
  series = {Operations Research Proceedings 2016},
  booktitle = {Operations Research Proceedings 2016},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-55701-4},
  doi       = {10.1007/978-3-319-55702-1_31},
  pages     = {227 -- 233},
  year      = {2017},
  abstract  = {Gearboxes are mechanical transmission systems that provide speed and torque conversions from a rotating power source. Being a central element of the drive train, they are relevant for the efficiency and durability of motor vehicles. In this work, we present a new approach for gearbox design: Modeling the design problem as a mixed-integer nonlinear program (MINLP) allows us to create gearbox designs from scratch for arbitrary requirements and—given enough time—to compute provably globally optimal designs for a given objective. We show how different degrees of freedom influence the runtime and present an exemplary solution.},
  language  = {en}
}
@incollection{LeiseAltherrPelz2018,
  author    = {Leise, Philipp and Altherr, Lena and Pelz, Peter F.},
  title     = {Energy-Efficient design of a water supply system for skyscrapers by mixed-integer nonlinear programming},
  series = {Operations Research Proceedings 2017},
  booktitle = {Operations Research Proceedings 2017},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-89919-0},
  doi       = {10.1007/978-3-319-89920-6_63},
  year      = {2018},
  abstract  = {The energy-efficiency of technical systems can be improved by a systematic design approach. Technical Operations Research (TOR) employs methods known from Operations Research to find a global optimal layout and operation strategy of technical systems. We show the practical usage of this approach by the systematic design of a decentralized water supply system for skyscrapers. All possible network options and operation strategies are modeled by a Mixed-Integer Nonlinear Program. We present the optimal system found by our approach and highlight the energy savings compared to a conventional system design.},
  language  = {en}
}
@inproceedings{RauschFriesenAltherretal.2018,
  author    = {Rausch, Lea and Friesen, John and Altherr, Lena and Pelz, Peter F.},
  title     = {Using mixed-integer programming for the optimal design of water supply networks for slums},
  series = {Operations Research Proceedings 2017},
  booktitle = {Operations Research Proceedings 2017},
  editor    = {Kliewer, Natalia and Ehmke, Jan Fabian and Bornd{\"o}rfer, Ralf},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-89919-0 (Print)},
  doi       = {10.1007/978-3-319-89920-6_68},
  pages     = {509 -- 516},
  year      = {2018},
  abstract  = {The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.},
  language  = {en}
}
@inproceedings{RauschLeiseEdereretal.2016,
  author    = {Rausch, Lea and Leise, Philipp and Ederer, Thorsten and Altherr, Lena and Pelz, Peter F.},
  title     = {A comparison of MILP and MINLP solver performance on the example of a drinking water supply system design problem},
  series = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering},
  booktitle = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering},
  editor    = {Papadrakakis, M. and Ppadopoulos, V. and Stefanou, G. and Plevris, V.},
  isbn      = {978-618-82844-0-1},
  pages     = {8509 -- 8527},
  year      = {2016},
  abstract  = {Finding a good system topology with more than a handful of components is a highly non-trivial task. The system needs to be able to fulfil all expected load cases, but at the same time the components should interact in an energy-efficient way. An example for a system design problem is the layout of the drinking water supply of a residential building. It may be reasonable to choose a design of spatially distributed pumps which are connected by pipes in at least two dimensions. This leads to a large variety of possible system topologies. To solve such problems in a reasonable time frame, the nonlinear technical characteristics must be modelled as simple as possible, while still achieving a sufficiently good representation of reality. The aim of this paper is to compare the speed and reliability of a selection of leading mathematical programming solvers on a set of varying model formulations. This gives us empirical evidence on what combinations of model formulations and solver packages are the means of choice with the current state of the art.},
  language  = {en}
}
@inproceedings{HueningWacheMagiera2021,
  author    = {H{\"u}ning, Felix and Wache, Franz-Josef and Magiera, David},
  title     = {Redundant bus systems using dual-mode radio},
  series = {Proceedings of Sixth International Congress on Information and Communication Technology},
  booktitle = {Proceedings of Sixth International Congress on Information and Communication Technology},
  publisher = {Springer},
  address   = {Singapore},
  isbn      = {978-981-16-2379-0},
  doi       = {10.1007/978-981-16-2380-6_73},
  pages     = {835 -- 842},
  year      = {2021},
  abstract  = {Communication via serial bus systems, like CAN, plays an important role for all kinds of embedded electronic and mechatronic systems. To cope up with the requirements for functional safety of safety-critical applications, there is a need to enhance the safety features of the communication systems. One measure to achieve a more robust communication is to add redundant data transmission path to the applications. In general, the communication of real-time embedded systems like automotive applications is tethered, and the redundant data transmission lines are also tethered, increasing the size of the wiring harness and the weight of the system. A radio link is preferred as a redundant transmission line as it uses a complementary transmission medium compared to the wired solution and in addition reduces wiring harness size and weight. Standard wireless links like Wi-Fi or Bluetooth cannot meet the requirements for real-time capability with regard to bus communication. Using the new dual-mode radio enables a redundant transmission line meeting all requirements with regard to real-time capability, robustness and transparency for the data bus. In addition, it provides a complementary transmission medium with regard to commonly used tethered links. A CAN bus system is used to demonstrate the redundant data transfer via tethered and wireless CAN.},
  language  = {en}
}
@article{Wolf2000,
  author    = {Wolf, Martin},
  title     = {Groupware related task design},
  series = {ACM SIGGROUP Bulletin},
  volume    = {21},
  journal   = {ACM SIGGROUP Bulletin},
  number    = {2},
  issn      = {2372-7403},
  doi       = {10.1145/605660.605662},
  pages     = {5 -- 8},
  year      = {2000},
  abstract  = {his report summarizes the results of a workshop on Groupware related task design which took place at the International Conference on Supporting Group Work Group'99, Arizona, from 14 th to 17 th November 1999. The workshop was addressed to people from different viewpoints, backgrounds, and domains: - Researchers dealing with questions of task analysis and task modeling for Groupware application from an academic point of view. They may contribute modelbased design approaches or theoretically oriented work - Practitioners with experience in the design and everyday use of groupware systems. They might refer to the practical side of the topic: "real" tasks, "real" problems, "real" users, etc.},
  language  = {en}
}
@inproceedings{KoenigVoelkerWolf2018,
  author    = {K{\"o}nig, Johannes Alexander and V{\"o}lker, Veronika and Wolf, Martin},
  title     = {The user-focused storybuilding framework for competence developing games - a design-framework considering the basics of an educational game's story},
  series = {ACHI 2018 : The Eleventh International Conference on Advances in Computer-Human Interactions},
  booktitle = {ACHI 2018 : The Eleventh International Conference on Advances in Computer-Human Interactions},
  isbn      = {978-1-61208-616-3},
  pages     = {98 -- 106},
  year      = {2018},
  abstract  = {During the development of a Competence Developing Game's (CDG) story it is indispensable to understand the target audience. Thereby, CDGs stories represent more than just the plot. The Story is about the Setting, the Characters and the Plot. As a toolkit to support the development of such a story, this paper introduces the UserFocused Storybuilding (short UFoS) Framework for CDGs. The Framework and its utilization will be explained, followed by a description of its development and derivation, including an empirical study. In addition, to simplify the Framework use regarding the CDG's target audience, a new concept of Nine Psychographic Player Types will be explained. This concept of Player Types provides an approach to handle the differences in between players during the UFoS Framework use. Thereby, this article presents a unique approach to the development of target group-differentiated CDGs stories.},
  language  = {en}
}