TY - JOUR AB - AbstractPolycarbonate (PC) is an amorphous polymer that is an extremely robust material with a high tenacity, and thus suitable for a lightweight construction with glass‐like transparency. Due to these advantageous properties, PC is often used in industry for example in medical devices, automotive headlamps, sporting equipment, electronics, and a variety of other products. PC is often subjected to uniaxial and biaxial loading conditions. Therefore, reliable material models have to take into account the various resulting experimental effects. For those reasons, we investigate PC specimens under uniaxial and biaxial loading by using different stretch rates and loading scenarios. In addition to that, we propose methods for optical measurement of local stretches to obtain the approximated local true stress. In future work, the displacement fields and the resulting reaction forces will be used for parameter identification of constitutive equations. AU - Hamdoun, Ayoub AU - Mahnken, Rolf ID - 52217 JF - PAMM KW - Electrical and Electronic Engineering KW - Atomic and Molecular Physics KW - and Optics SN - 1617-7061 TI - Experimental investigations of uniaxial and biaxial cold stretching within PC‐films and bars using optical measurements ER - TY - GEN AU - Gröger, Benjamin AU - Wiebicke, Felix AU - Koch, Ilja AU - Gude, Maik AU - Gilich, Julian AU - Meschut, Gerson ID - 52537 T2 - 24. Kolloquium: Gemeinsame Forschung in der Klebtechnik TI - Experimentelle und numerische Analyse des Fließverhaltens von hochviskosen Wärmeleitstoffen im Fertigungsprozess ER - TY - GEN AU - Franke, Patrick ID - 52504 TI - Experimentelle Untersuchung und Modellierung des flüssigseitigen Stofftransports in Anstaupackungen ER - TY - CONF AB - Digital Servitization is one of the significant trends affecting the manufacturing industry. Companies try to tackle challenges regarding their differentiation and profitability using digital services. One specific type of digital services are smart services, which are digital services built on data from smart products. Introducing these kinds of offerings into the portfolio of manufacturing companies is not trivial. Moreover, they require conscious action to align all relevant capabilities to realize the respective business goals. However, what capabilities are generally relevant for smart services remains opaque. We conducted a systematic literature review to identify them and extended the results through an interview study. Our analysis results in 78 capabilities clustered among 12 principles and six dimensions. These results provide significant support for the smart service transformation of manufacturing companies and for structuring the research field of smart services. AU - Koldewey, Christian AU - Fichtler, Timm AU - Scholtysik, Michel AU - Biehler, Jan AU - Schreiner, Nick AU - Sommer, Franziska AU - Schacht, Maximilian AU - Kaufmann, Jonas AU - Rabe, Martin AU - Sedlmeier, Joachim AU - Dumitrescu, Roman ID - 48632 KW - Digital Servitization KW - Transformation KW - Capabilities KW - Maturity KW - Smart Services TI - Exploring Capabilities for the Smart Service Transformation in Manufacturing: Insights from Theory and Practice ER - TY - GEN AB - We rigorously derive novel and sharp finite-data error bounds for highly sample-efficient Extended Dynamic Mode Decomposition (EDMD) for both i.i.d. and ergodic sampling. In particular, we show all results in a very general setting removing most of the typically imposed assumptions such that, among others, discrete- and continuous-time stochastic processes as well as nonlinear partial differential equations are contained in the considered system class. Besides showing an exponential rate for i.i.d. sampling, we prove, to the best of our knowledge, the first superlinear convergence rates for ergodic sampling of deterministic systems. We verify sharpness of the derived error bounds by conducting numerical simulations for highly-complex applications from molecular dynamics and chaotic flame propagation. AU - Philipp, Friedrich M. AU - Schaller, Manuel AU - Boshoff, Septimus AU - Peitz, Sebastian AU - Nüske, Feliks AU - Worthmann, Karl ID - 51160 T2 - arXiv:2402.02494 TI - Extended Dynamic Mode Decomposition: Sharp bounds on the sample efficiency ER - TY - JOUR AU - Moretto, Giordano AU - Schnell, Nicolas AU - Frey, Jonathan AU - Karakaya, Yasin AU - Amstutz, Alois AU - Diehl, Moritz AU - Kasper, Tina AU - Onder, Christopher ID - 50841 JF - Control Engineering Practice TI - Fast model-based calibration of multiple injections for a CI engine using nonlinear optimal control VL - 145 ER - TY - JOUR AB - We derive efficient algorithms to compute weakly Pareto optimal solutions for smooth, convex and unconstrained multiobjective optimization problems in general Hilbert spaces. To this end, we define a novel inertial gradient-like dynamical system in the multiobjective setting, which trajectories converge weakly to Pareto optimal solutions. Discretization of this system yields an inertial multiobjective algorithm which generates sequences that converge weakly to Pareto optimal solutions. We employ Nesterov acceleration to define an algorithm with an improved convergence rate compared to the plain multiobjective steepest descent method (Algorithm 1). A further improvement in terms of efficiency is achieved by avoiding the solution of a quadratic subproblem to compute a common step direction for all objective functions, which is usually required in first-order methods. Using a different discretization of our inertial gradient-like dynamical system, we obtain an accelerated multiobjective gradient method that does not require the solution of a subproblem in each step (Algorithm 2). While this algorithm does not converge in general, it yields good results on test problems while being faster than standard steepest descent. AU - Sonntag, Konstantin AU - Peitz, Sebastian ID - 46019 JF - Journal of Optimization Theory and Applications TI - Fast Multiobjective Gradient Methods with Nesterov Acceleration via Inertial Gradient-Like Systems ER - TY - GEN AB - We prove Feynman-Kac formulas for the semigroups generated by selfadjoint operators in a class containing Fr\"ohlich Hamiltonians known from solid state physics. The latter model multi-polarons, i.e., a fixed number of quantum mechanical electrons moving in a polarizable crystal and interacting with the quantized phonon field generated by the crystal's vibrational modes. Both the electrons and phonons can be confined to suitable open subsets of Euclidean space. We also include possibly very singular magnetic vector potentials and electrostatic potentials. Our Feynman-Kac formulas comprise Fock space operator-valued multiplicative functionals and can be applied to every vector in the underlying Hilbert space. In comparison to the renormalized Nelson model, for which analogous Feynman-Kac formulas are known, the analysis of the creation and annihilation terms in the multiplicative functionals requires novel ideas to overcome difficulties caused by the phonon dispersion relation being constant. Getting these terms under control and generalizing other construction steps so as to cover confined systems are the main achievements of this article. AU - Hinrichs, Benjamin AU - Matte, Oliver ID - 52691 T2 - arXiv:2403.12147 TI - Feynman-Kac formulas for semigroups generated by multi-polaron Hamiltonians in magnetic fields and on general domains ER - TY - BOOK ED - Adelmann, Ralf ED - Matzner, Tobias ED - Miggelbrink, Monique ED - Schulz, Christian ID - 51764 TI - Filter – Medienwissenschaftliche Symposien der DFG ER - TY - JOUR AB - In der Professionalisierung von Lehrkräften ist die Selbst-reflexion eine wesentliche Voraussetzung, da sie zentral für die Weiterentwicklung der eigenen Kompetenzen ist. Daraus ergibt sich die Notwendigkeit, bereits in der ersten Phase der Lehrkräftebildung die Selbstreflexion und die Weiterentwicklungsorientierung zu fördern. Hierzu sind auf Grund des sozialen Settings gezielte reflexionsorientierte Workshops chancenreich. Um die Effekte von reflexionsorientierten Workshops und dabei den Zusammenhang zwischen der Selbst-reflexion und der Weiterentwicklungsorientierung zu überprüfen, wurden anhand einer Stichprobe von N = 646 Lehramtsstudierenden die Entwicklung der Selbst-reflexion und Weiterentwicklungsorientierung beim Besuch von Workshops zu überfachlichen Kompetenzen untersucht. Die Datenerhebung erfolgte vor, direkt nach und erneut vier bis sechs Wochen nach den reflexionsorientierten Workshops mittels eines Fragebogens. Durch Varianzanalysen können in Bezug auf die Selbst-reflexion direkt nach den Workshops signifikante Effekte sowie eine konstante Ausprägung vier bis sechs Wochen später nachgewiesen werden. Weiterhin konnte ein signifikanter Anstieg bei der Weiterentwicklungsorientierung über die drei Messzeitpunkte verzeichnet werden. Ebenso zeigte sich ein positiver Effekt der Selbstreflexion auf den Anstieg der Weiterentwicklungsorientierung. AU - Kleine, Sabrina M AU - Sohlau, Sylvia AU - Seifert, Andreas AU - Buhl, Heike M. ID - 52328 IS - 1 JF - Herausforderung Lehrer*innenbildung - Zeitschrift zur Konzeption, Gestaltung und Diskussion TI - Förderung der Selbstreflexion und Weiterentwicklungsorientierung durch reflexionsorientierte Workshops im Lehramtsstudium VL - 7 ER -