@book{RiessWallraff2024, author = {Rieß, Bernhard and Wallraff, Christoph}, title = {{\"U}bungsbuch Signale und Systeme}, edition = {4. Auflage}, publisher = {Springer Nature}, address = {Wiesbaden}, isbn = {9783658424244}, doi = {10.1007/978-3-658-42425-1}, year = {2024}, subject = {Aufgabensammlung}, language = {de} } @article{VansteenkisteChouWeigandetal.2009, author = {Vansteenkiste, A. and Chou, Kang Wei and Weigand, M. and Curcic, Michael and Sackmann, V. and Stoll, H. and Tyliszczak, T. and Woltersdorf, G. and Back, Christian H. and Sch{\"u}tz, G. and Van Waeyenberge, B.}, title = {X-ray imaging of the dynamic magnetic vortex core deformation}, series = {Nature Physics}, volume = {5}, journal = {Nature Physics}, number = {5}, publisher = {Nature Publishing Group}, issn = {1745-2473}, doi = {10.1038/nphys1231}, pages = {332 -- 334}, year = {2009}, language = {en} } @article{EchternachtLinnemannDreesetal.2013, author = {Echternacht, David and Linnemann, Christian and Drees, Tim and Breuer, Christopher and Moser, Albert}, title = {Wechselwirkungen zwischen Druckluftspeichern und Netzengp{\"a}ssen in zuk{\"u}nftigen Energiesystemen}, series = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien}, volume = {25}, journal = {Solarzeitalter : Politik, Kultur und {\"O}konomie erneuerbarer Energien}, number = {1}, publisher = {EUROSOLAR Verl.}, organization = {EUROSOLAR Verl.}, pages = {54 -- 59}, year = {2013}, language = {de} } @article{WolfThielbeerUlrichetal.2024, author = {Wolf, Dominik Werner and Thielbeer, Boris and Ulrich, Markus and Braun, Alexander}, title = {Wavefront aberration measurements based on the Background Oriented Schlieren method}, series = {Measurement: Sensors}, journal = {Measurement: Sensors}, publisher = {Elsevier}, issn = {2665-9174}, doi = {10.1016/j.measen.2024.101509}, year = {2024}, abstract = {Applications based on neural networks tend to be very sensitive to dataset shifts. Hence, the perception chain for autonomous driving is safeguarded against perturbations by imposing exaggerated optical quality requirements. Due to the non-linear coupling of optical elements, system requirements of camera-based Advanced Driver Assistance Systems (ADAS) can not be easily decomposed into individual part tolerances of the objective lens and the windscreen. This holds true for intensity-based part measurements, e.g. slanted edge measurements according to ISO12233, which can fundamentally not capture interference effects of the complex light field. Instead wavefront-based part measurements are required. Unfortunately, state-of-the-art wavefront measurement techniques are limited by the spanned sensitive area of the Shack-Hartmann lenslet array or the aperture stop of a corresponding interferometrical setup, respectively. Further, both measurements are limited by using collimated light only, whereas the target application has a large (angular) field of view, requiring many different measurements. We address those bottlenecks by proposing a novel wavefront aberration measurement procedure based on the Background Oriented Schlieren (BOS) method utilizing image auto-correlation. We analytically derive the governing equations for determining the Zernike coefficients of a wavefront aberration map in the knowledge of the local refractive power map obtained by a high-resolution BOS measurement. Furthermore, we experimentally demonstrate the feasibility of the measurement technique. Applying this novel method yields the promise of affordable wavefront aberration measurements only requiring a high-resolution camera and a sophisticated alignment strategy.}, language = {en} } @misc{Franz1995, author = {Franz, J{\"u}rgen H.}, title = {Was ist ein Baum? Eine Kurzgeschichte aus dem Leben des Herrn Schwarzweiß}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-9568}, year = {1995}, abstract = {Herr Schwarzweiß ist seit seiner Geburt nicht in der Lage Farben zu erkennen. Seine Welt ist schwarzweiß. Doch kann er sehr gut zwischen den verschiedenen Graut{\"o}nen unterscheiden. F{\"u}r ihn ist Weiß nicht gleich Weiß. Es gibt ein sehr helles Weiß, ein dunkleres Weiß, ein grau unterlegtes Weiß und viele andere Arten von Weiß. ...}, language = {de} } @article{WeigandVanWaeyenbergeVansteenkisteetal.2009, author = {Weigand, Markus and Van Waeyenberge, Bartel and Vansteenkiste, Arne and Curcic, Michael and Sackmann, Vitalij and Stoll, Hermann and Tyliszczak, Tolek and Kaznatcheev, Konstantine and Bertwistle, Drew and Woltersdorf, Georg and Back, Christian H. and Sch{\"u}tz, Gisela}, title = {Vortex Core Switching by Coherent Excitation with Single In-Plane Magnetic Field Pulses}, series = {Physical Review Letters}, volume = {102}, journal = {Physical Review Letters}, number = {7}, publisher = {American Physical Society}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.102.077201}, year = {2009}, language = {en} } @article{StruweWredeVennegeerts2023, author = {Struwe, Julian and Wrede, Holger and Vennegeerts, Hendrik}, title = {Validation Aspects for Grid-Forming Converters Based on System Characteristics and Inertia Impact}, series = {Energies}, volume = {16}, journal = {Energies}, number = {21}, publisher = {MDPI}, issn = {1996-1073}, doi = {10.3390/en16217357}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-48751}, year = {2023}, abstract = {Grid-forming converters are considered a key technology for electrical grids with a high share of renewable energy. However, there is a lack of a general, robust and verifiable definition of what constitutes this behaviour. Therefore, this paper presents three simple scenarios that enable such a definition. They are based on simple black-box simulations that allow manufacturers to protect their development work. It can be shown that grid forming can be clearly distinguished from grid-following controls by their grid behaviour in the proposed scenarios. Extensive results illustrate this and also provide suggestions to deepen the understanding of grid-forming grid behaviour and its impact on system inertia. These findings should inspire the development of a clear definition and ultimately new requirements for converter systems.}, subject = {Stromrichter}, language = {en} } @misc{Kern2012, author = {Kern, Mirco}, title = {Untersuchung eines Mikroprozessor-Betriebssystems mit 6LoWPAN-Stack in Hinblick auf die Portierung auf neue Prozessoren}, address = {D{\"u}sseldorf}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-7084}, pages = {59}, year = {2012}, abstract = {Innerhalb dieser Dokumentation des im Labor f{\"u}r Informatik an der Fachhochschule D{\"u}sseldorf durchgef{\"u}hrten Parxisprojekt werden zun{\"a}chst Grundlagen vermittelt, die n{\"o}tig sind, um den Kontext des Projekts und das Kommunikationsprotokoll 6LoWPAN zu verstehen. Da das Ziel des Praxisprojekts die Untersuchung eines Kommunikationssystems mit 6LoWPAN-Stack hinsichtlich dessen Portierungsm{\"o}glichkeiten ist, werden hierauf verschiedene, bereits auf dem Markt befindliche L{\"o}sungen analysiert und verglichen, die entweder direkt den drahtlosen Datenaustausch mit Hilfe des 6LoWPAN-Protokolls oder aber die Erweiterung zu einem eigenen Stack erm{\"o}glichen und dargestellt, warum das Mikrocontroller-Betriebssystem Contiki als geeignetster Kandidat hierf{\"u}r erscheint. Als Basis f{\"u}r die Analyse in Hinblick auf eine m{\"o}gliche Portierung dient der Mikrocontroller ATmega128RFA1 des Herstellers Atmel, der {\"u}ber eine integrierte Transceiver-Einheit verf{\"u}gt. Nach der Vermittlung der Grundlagen des Contiki-Betriebssystems, die insbesondere den schichtenartigen Aufbau der Verzeichnisse und das komplexe, {\"u}ber Makefiles organisierte Build-System betreffen, folgt die Beschreibung der Vorgehensweise bei der Portierung von Contiki und den dabei aufgetretenen Problemen. Da w{\"a}hrend der Arbeit an diesem Praxisprojekt eine neue Version des Contiki-Betriebssystems ver{\"o}ffentlicht wurde, wird zus{\"a}tzlich auf diese Version und die vorhandenen Inkompatibilit{\"a}ten zwischen den verschiedenen Contiki-Versionen eingegangen und eine Beispielanwendung f{\"u}r die neue Version implementiert. Die Performancemessungen verschiedener Kommunikationshardware runden diese Arbeit zusammen mit dem Fazit, das nocheinmal auf das Betriebssystem Contiki, den Mikrocontroller ATmega128RFA1 und m{\"o}gliche Vertiefungsund Optimierungsm{\"o}glichkeiten eingeht, ab.}, language = {de} } @unpublished{YuwonoSchwungSchwung2024, author = {Yuwono, Steve and Schwung, Dorothea and Schwung, Andreas}, title = {Transfer learning of state-based potential games for process optimization in decentralized manufacturing systems}, series = {arXiv}, journal = {arXiv}, publisher = {arXiv}, doi = {10.48550/arXiv.2408.05992}, pages = {48}, year = {2024}, abstract = {This paper presents a novel transfer learning approach in state-based potential games (TL-SbPGs) for enhancing distributed self-optimization in manufacturing systems. The approach focuses on the practical relevant industrial setting where sharing and transferring gained knowledge among similar-behaved players improves the self-learning mechanism in large-scale systems. With TL-SbPGs, the gained knowledge can be reused by other players to optimize their policies, thereby improving the learning outcomes of the players and accelerating the learning process. To accomplish this goal, we develop transfer learning concepts and similarity criteria for players, which offer two distinct settings: (a) predefined similarities between players and (b) dynamically inferred similarities between players during training. We formally prove the applicability of the SbPG framework in transfer learning. Additionally, we introduce an efficient method to determine the optimal timing and weighting of the transfer learning procedure during the training phase. Through experiments on a laboratory-scale testbed, we demonstrate that TL-SbPGs significantly boost production efficiency while reducing power consumption of the production schedules while also outperforming native SbPGs.}, subject = {Maschinelles Lernen}, language = {en} } @incollection{ChristmannBusboomFeigeetal.2020, author = {Christmann, Simon and Busboom, Imke and Feige, Volker K.S. and Haehnel, Hartmut}, title = {Towards Automated Quality Inspection Using a Semi-Mobile Robotized Terahertz System}, series = {2020 Third International Workshop on Mobile Terahertz Systems (IWMTS)}, booktitle = {2020 Third International Workshop on Mobile Terahertz Systems (IWMTS)}, publisher = {IEEE}, address = {Essen}, isbn = {978-1-7281-5598-2}, doi = {10.1109/IWMTS49292.2020.9166259}, pages = {1 -- 5}, year = {2020}, language = {en} }