@phdthesis{37645, abstract = {{Für den Erwerb fachmethodischer Fähigkeiten stellen Laborpraktika eine zentrale Lerngelegenheiten des Physikstudiums dar. Trotz ihrer hohen Bedeutung fehlt ein hochschulfachdidaktischer Diskurs zu einer lehr-lerntheoretischen Fundierung. Zudem wird ihre Lernwirksamkeit aufgrund der bestehenden didaktischen Gestaltung kritisiert. Die weit verbreiteten engmaschigen Aufgabenstellungen enthalten keine Anreize zur tiefergehenden Auseinandersetzung mit den Inhalten. Um der Diskrepanz zwischen den Zielsetzungen und den von den Lernenden erworbenen Fähigkeiten entgegenzuwirken, liegen aktuell nur wenige und zudem nur punktuelle Grundlagen für eine evidenzbasierte Überarbeitung dieses Veranstaltungsformates vor. Ziel dieser Arbeit ist daher, einen Vorschlag für ein performanzorientiertes Kompetenzstrukturmodell auf universitärem Niveau zu entwickeln, das die Inhaltsbereiche, die experimentellen Fähigkeiten und Fertigkeiten sowie die Qualitätsausprägungen experimenteller Handlungen systematisiert.Die Modellierung ist auf Basis der Analyse videografierter experimenteller Performanz von 16 unterschiedlich fähigen Proband:innen realisiert worden. Für die Entwicklung der Dimensionen Fachmethodik und Qualitätsausprägung werden unter Nutzung der qualitativen Forschungsansätze Dokumentarische Methode und Typenbildung die charakteristischen Merkmale universitären Experimentierens identifiziert und anschließend systematisiert. Zur Prüfung der Passung des Modells zur Perspektive der Wissenschaft Physik ist ein Interrating mit einem Fachwissenschaftler durchgeführt worden, das sehr gute Übereinstimmungswerte liefert. Die Passung des Modells zur Perspektive der Praktikumsleiter:innen ist durch ein Expertenrating erfolgt. Ein Rangfolgen-Vergleich zeigt hohe Übereinstimmungswerte.}}, author = {{Bauer, Anna Brigitte}}, publisher = {{LibreCat University}}, title = {{{Experimentelle Kompetenz Physikstudierender}}}, doi = {{10.17619/UNIPB/1-1652}}, year = {{2023}}, } @article{41874, author = {{Pfeiffer, Jella and Gutschow, Julia and Haas, Christian and Möslein, Florian and Maspfuhl, Oliver and Borgers, Frederik and Alpsancar, Suzana}}, issn = {{2363-7005}}, journal = {{Business & Information Systems Engineering}}, keywords = {{Information Systems}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Algorithmic Fairness in AI}}}, doi = {{10.1007/s12599-023-00787-x}}, year = {{2023}}, } @misc{41948, author = {{Süßmann, Johannes}}, booktitle = {{wissen/leben. Die Zeitung der WWU Münster}}, pages = {{6}}, title = {{{Zu »wahrer Glückseligkeit« anleiten. WWU-Gründervater Franz von Fürstenberg wollte vor allem den Fortbestand des Landes sichern – ein Gastbeitrag}}}, volume = {{17/1}}, year = {{2023}}, } @unpublished{42160, abstract = {{The goal of this paper is to make a strong point for the usage of dynamical models when using reinforcement learning (RL) for feedback control of dynamical systems governed by partial differential equations (PDEs). To breach the gap between the immense promises we see in RL and the applicability in complex engineering systems, the main challenges are the massive requirements in terms of the training data, as well as the lack of performance guarantees. We present a solution for the first issue using a data-driven surrogate model in the form of a convolutional LSTM with actuation. We demonstrate that learning an actuated model in parallel to training the RL agent significantly reduces the total amount of required data sampled from the real system. Furthermore, we show that iteratively updating the model is of major importance to avoid biases in the RL training. Detailed ablation studies reveal the most important ingredients of the modeling process. We use the chaotic Kuramoto-Sivashinsky equation do demonstarte our findings.}}, author = {{Werner, Stefan and Peitz, Sebastian}}, booktitle = {{arXiv:2302.07160}}, title = {{{Learning a model is paramount for sample efficiency in reinforcement learning control of PDEs}}}, year = {{2023}}, } @article{27426, abstract = {{Regularization is used in many different areas of optimization when solutions are sought which not only minimize a given function, but also possess a certain degree of regularity. Popular applications are image denoising, sparse regression and machine learning. Since the choice of the regularization parameter is crucial but often difficult, path-following methods are used to approximate the entire regularization path, i.e., the set of all possible solutions for all regularization parameters. Due to their nature, the development of these methods requires structural results about the regularization path. The goal of this article is to derive these results for the case of a smooth objective function which is penalized by a piecewise differentiable regularization term. We do this by treating regularization as a multiobjective optimization problem. Our results suggest that even in this general case, the regularization path is piecewise smooth. Moreover, our theory allows for a classification of the nonsmooth features that occur in between smooth parts. This is demonstrated in two applications, namely support-vector machines and exact penalty methods.}}, author = {{Gebken, Bennet and Bieker, Katharina and Peitz, Sebastian}}, journal = {{Journal of Global Optimization}}, number = {{3}}, pages = {{709--741}}, title = {{{On the structure of regularization paths for piecewise differentiable regularization terms}}}, doi = {{10.1007/s10898-022-01223-2}}, volume = {{85}}, year = {{2023}}, } @article{43018, author = {{Alhaddad, Samer and Förstner, Jens and Grynko, Yevgen}}, issn = {{0022-4073}}, journal = {{Journal of Quantitative Spectroscopy and Radiative Transfer}}, keywords = {{tet_topic_scattering}}, publisher = {{Elsevier BV}}, title = {{{Numerical study of light backscattering from layers of absorbing irregular particles larger than the wavelength}}}, doi = {{10.1016/j.jqsrt.2023.108557}}, volume = {{302}}, year = {{2023}}, } @inproceedings{31849, author = {{Hoffmann, Max and Biehler, Rolf}}, booktitle = {{Proceedings of the Fourth Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022)}}, editor = {{Trigueros, Marı́a and Barquero, Berta and Hochmuth, Reinhard and Peters, Jana}}, keywords = {{Teaching and learning of specific topics in university mathematics, Transition to, across and from university mathematics, Student Teachers, Geometry, Congruence, Double Discontinuity.}}, publisher = {{University of Hannover and INDRUM.}}, title = {{{Student Teachers ’ Knowledge of Congruence before a University Course on Geometry}}}, year = {{2023}}, } @inproceedings{43097, author = {{Florensa, Ignasio and Hoffmann, Max and Romo Vázquez, Avenilde and Zandieh, Michelle and Martínez-Planell, Rafael}}, booktitle = {{Proceedings of the Fourth Conference of the International Network for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022)}}, editor = {{Trigueros, Marı́a and Barquero, Berta and Hochmuth, Reinhard and Peters, Jana}}, title = {{{Innovations in university teaching based on mathematic education research}}}, year = {{2023}}, } @article{43464, abstract = {{Lightweight design is a common approach to reduce energy demand in the use stage of vehicles. The production of lightweight materials is usually associated with an increase in energy demand, so the environmental impacts of lightweight structures need to be assessed holistically using a life cycle assessment. To estimate the life cycle environmental impacts of a product in its developmental stage, for example, by life cycle engineering, future changes in relevant influencing factors must be considered. Prospective life cycle assessment provides methods for integrating future scenarios into life cycle assessment studies. However, approaches for integrating prospective life cycle assessment into product development are limited. The objective of this work is to provide the methodological foundation for integrating future scenarios of relevant influencing factors in the development of lightweight structures. The applicability of the novel methodology is demonstrated by a case study of a structural component in a steel, aluminium, and hybrid design. The results show that appropriate decarbonisation measures can reduce the life cycle greenhouse gas emissions by up to 95 percent until 2050. We also found that shifts in the environmentally optimal design are possible in future scenarios. Therefore, the methodology and data provided contribute to improved decision-making in product development.}}, author = {{Ostermann, Moritz and Grenz, Julian and Triebus, Marcel and Cerdas, Felipe and Marten, Thorsten and Tröster, Thomas and Herrmann, Christoph}}, issn = {{1996-1073}}, journal = {{Energies}}, keywords = {{Life Cycle Engineering, Life Cycle Assessment, Lightweight Design, Prospective LCA, Future-oriented LCA, Energy System, Material production, Sustainable production}}, number = {{8}}, publisher = {{MDPI AG}}, title = {{{Integrating Prospective Scenarios in Life Cycle Engineering: Case Study of Lightweight Structures}}}, doi = {{10.3390/en16083371}}, volume = {{16}}, year = {{2023}}, } @article{42252, abstract = {{Die Wirtschaftlichkeit von Wärmemotoren wird maßgeblich durch die Rückführung von Wärme in Rekuperatoren beeinflusst. Beim isobaren Expansionsmotor vom Bush-Typ, einem Wärmemotor, welcher bereits mit Wärmequellen ab 60°C betrieben werden kann, steigt der thermische Wirkungsgrad durch den Einsatz von Rekuperatoren signifikant. Gleichzeitig wirken sich das Fluidvolumen des Wärmeübertragers sowie der beim Betrieb auftretende Druckverlust negativ auf den thermischen Wirkungsrad aus. In dieser Arbeit wird der Zusammenhang von Totvolumen, Druckverlust und Wärmerückgewinnung untersucht und Empfehlungen für den Betrieb von Rekuperatoren am isobaren Expansionsmotor gegeben.}}, author = {{Mügge, Nils and Kronberg, Alexander and Glushenkov, Maxim and Kenig, Eugeny Y.}}, journal = {{Chemie Ingenieur Technik}}, keywords = {{Isobarer Expansionsmotor, Dynamische Wärmeübertragungsmodellierung, Phasenwechsel, dichte Arbeitsmedien}}, number = {{5}}, publisher = {{Wiley}}, title = {{{Untersuchung überlagerter Effekte von Druckverlust und Totvolumen durch Rekuperation am isobaren Expansionsmotor}}}, doi = {{10.1002/cite.202200243}}, volume = {{95}}, year = {{2023}}, } @article{36983, abstract = {{AbstractThe use of structured measuring systems to prevent wall slip is a common approach to obtain absolute rheological values. Typically, only the minimum distance between the measuring surfaces is used for further calculation, implying that no flow occurs between the structural elements. But this assumption is misleading, and a gap correction is necessary. To determine the radius correction $$\Delta r$$ Δ r for specific geometries, we conducted investigations on three Newtonian fluids (two silicon oils and one suspension considered to be Newtonian in the relevant shear rate range). The results show that $$\Delta r$$ Δ r is not only shear- and material-independent, but geometry-dependent, providing a Newtonian flow behaviour in a similar viscosity range. Therefore, a correction value can be determined with only minute deviations in different Newtonian fluids. As the conducted laboratory measurements are very time-consuming and expensive, a CFD-approach with only very small deviations was additionally developed and compared for validation purposes. Therefore, simulation is an effective and resource-efficient alternative to the presented laboratory measurements to determine $$\Delta r$$ Δ r for the correction of structured coaxial geometries even for non-Newtonian fluids in the future.}}, author = {{Josch, Sebastian and Jesinghausen, Steffen and Dechert, Christopher and Schmid, Hans-Joachim}}, issn = {{0035-4511}}, journal = {{Rheologica Acta}}, keywords = {{rheology, rheometry, suspension, coaxial, correction}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Experimental and simulative determination and correction of the effective gap extension in structured coaxial measuring systems}}}, doi = {{10.1007/s00397-023-01383-2}}, year = {{2023}}, } @inproceedings{30125, abstract = {{We present an approach for guaranteed constraint satisfaction by means of data-based optimal control, where the model is unknown and has to be obtained from measurement data. To this end, we utilize the Koopman framework and an eDMD-based bilinear surrogate modeling approach for control systems to show an error bound on predicted observables, i.e., functions of the state. This result is then applied to the constraints of the optimal control problem to show that satisfaction of tightened constraints in the purely data-based surrogate model implies constraint satisfaction for the original system.}}, author = {{Schaller, Manuel and Worthmann, Karl and Philipp, Friedrich and Peitz, Sebastian and Nüske, Feliks}}, booktitle = {{IFAC-PapersOnLine}}, number = {{1}}, pages = {{169--174}}, title = {{{Towards reliable data-based optimal and predictive control using extended DMD}}}, doi = {{10.1016/j.ifacol.2023.02.029}}, volume = {{56}}, year = {{2023}}, } @article{43094, abstract = {{}}, author = {{Heck, Tamara and Steinhardt, Isabel and Rahal, Rima-Maria and Schubotz, Moritz and Scholl, Dominik and Behrens, Sarah}}, issn = {{2367-7163}}, journal = {{Research Ideas and Outcomes}}, keywords = {{Open Science}}, publisher = {{Pensoft Publishers}}, title = {{{Bootstrapping the Open Science culture: The fellowship approach}}}, doi = {{10.3897/rio.9.e103675}}, volume = {{9}}, year = {{2023}}, } @proceedings{35062, editor = {{Meine, Sabine and Otto, Arnold and Süßmann, Johannes}}, isbn = {{978-3-8260-7218-5}}, publisher = {{Königshausen & Neumann}}, title = {{{Musiklandschaften zwischen Rhein und Weser. Pluralisierung und Verflechtung entlang des Hellwegs in der Frühen Neuzeit. Unter Mitarbeit v. Markus Lauert}}}, doi = {{https://doi.org/10.36202/9783826077920}}, volume = {{13}}, year = {{2023}}, } @unpublished{43132, author = {{Meier, Torsten and Grisard, S. and Trifonov, A.V. and Rose, Hendrik and Reichhardt, R. and Reichelt, Matthias and Schneider, C. and Kamp, M. and Höfling, S. and Bayer, M. and Akimov, I.A}}, booktitle = {{arxiv:2302.02480}}, title = {{{Temporal sorting of optical multi-wave-mixing processes in semiconductor quantum dots}}}, year = {{2023}}, } @article{44097, abstract = {{We present strong enhancement of third harmonic generation in an amorphous silicon metasurface consisting of elliptical nano resonators. We show that this enhancement originates from a new type of multi-mode Fano mechanism. These ‘Super-Fano’ resonances are investigated numerically in great detail using full-wave simulations. The theoretically predicted behavior of the metasurface is experimentally verified by linear and nonlinear transmission spectroscopy. Moreover, quantitative nonlinear measurements are performed, in which an absolute conversion efficiency as high as ηmax ≈ 2.8 × 10−7 a peak power intensity of 1.2 GW cm−2 is found. Compared to an unpatterned silicon film of the same thickness amplification factors of up to ~900 are demonstrated. Our results pave the way to exploiting a strong Fano-type multi-mode coupling in metasurfaces for high THG in potential applications.}}, author = {{Hähnel, David and Golla, Christian and Albert, Maximilian and Zentgraf, Thomas and Myroshnychenko, Viktor and Förstner, Jens and Meier, Cedrik}}, issn = {{2047-7538}}, journal = {{Light: Science & Applications}}, keywords = {{tet_topic_meta}}, number = {{1}}, pages = {{97}}, publisher = {{Springer Nature}}, title = {{{A multi-mode super-fano mechanism for enhanced third harmonic generation in silicon metasurfaces}}}, doi = {{https://doi.org/10.1038/s41377-023-01134-1}}, volume = {{12}}, year = {{2023}}, } @book{44083, author = {{Bauer, Anna Brigitte}}, isbn = {{978-3-8325-5625-9}}, publisher = {{Logos Verlag Berlin GmbH}}, title = {{{Experimentelle Kompetenz Physikstudierender. Entwicklung und erste Erprobung eines performanzorientierten Kompetenzstrukturmodells unter Nutzung qualitativer Methoden}}}, doi = {{10.30819/5625}}, volume = {{352}}, year = {{2023}}, } @misc{43374, author = {{Schürmann, Patrick}}, title = {{{ A Formal Comparison of Advanced Digital Signature Primitives}}}, year = {{2023}}, } @article{42515, abstract = {{ Microcellular wood fiber reinforced polymers offer the possibility to reduce the use of fossil raw materials. In particular, thick-walled structures with thicknesses greater than 6 mm offer a high potential for weight savings. This study investigates the cell structures and mechanical properties of injection-molded test specimens. The influence of different thicknesses (6–10 mm) along with different chemical blowing agents (endothermic, exothermic) with varying dosages (0–2 wt%) is analyzed. The investigations reveal that exothermic chemical blowing agents form finer cells consistently to thin-walled structures than endothermic ones. Higher foaming agent content leads to higher pore fractions, with many small cells coalescing into a large open-pore cell network. The mechanical properties depend mainly on the pore content of the sample. The specific tensile properties deteriorate with the use of chemical blowing agents (CFA), whereas the sandwich structure produced with compact edge layers has a positive influence on the specific flexural properties. }}, author = {{Moritzer, Elmar and Flachmann, Felix}}, issn = {{0021-955X}}, journal = {{Journal of Cellular Plastics}}, keywords = {{Materials Chemistry, Polymers and Plastics, General Chemistry}}, number = {{3}}, pages = {{187--199}}, publisher = {{SAGE Publications}}, title = {{{Morphological and mechanical properties of foamed thick-walled Wood-Plastic-Composite structures}}}, doi = {{10.1177/0021955x231161175}}, volume = {{59}}, year = {{2023}}, } @article{42179, author = {{Burmeister, Sascha Christian and Schryen, Guido}}, journal = {{Energy Systems}}, publisher = {{Springer}}, title = {{{Distribution Network Optimization: Predicting computation times to design scenario analysis for network operators}}}, doi = {{10.1007/s12667-023-00572-5}}, year = {{2023}}, }