@inproceedings{45661, abstract = {{Effect chain modelling is a method for creating information models for impact analyses of changes in system elements. For the estimation of change propagation, dependencies between requirements must be detected. The high number of require- ment dependencies in the engineering of complex technical systems results in the need for automation. In a study, it was shown that transformer models (BERT) are suitable for the automated dependency analysis of requirements. However, there are currently deficits in the applicability of the models for different projects without an extensive and heterogeneous training database. This paper investigates how active learning can be used to train BERT models (active-BERT) in order to increase the performance of the models for classifying requi- rement dependencies of projects with heterogeneous require- ments. The results show that the performance of the models increases significantly through active learning. Through active- BERT, engineers are enabled to model effect chains efficiently and to handle requirement changes effectively.}}, author = {{Gräßler, Iris and Preuß, Daniel}}, booktitle = {{Stuttgarter Symposium für Produktentwicklung SSP 2023}}, editor = {{Hölzle, Katharina and Kreimeyer, Matthias and Roth, Daniel and Maier, Thomas and Riedel, Oliver}}, issn = {{2364-4885}}, location = {{Stuttgart}}, publisher = {{Fraunhofer IAO}}, title = {{{Automatisierte Abhängigkeitsanalyse von Anforderungen zur Wirkkettenmodellierung}}}, year = {{2023}}, } @book{42949, author = {{Fuchs, Christian}}, isbn = {{9781032362724}}, publisher = {{Routledge}}, title = {{{Digital Democracy and the Digital Public Sphere}}}, volume = {{6}}, year = {{2023}}, } @unpublished{40982, abstract = {{Effective photoinduced charge transfer makes molecular bimetallic assemblies attractive for applications as active light induced proton reduction systems. For a more sustainable future, development of competitive base metal dyads is mandatory. However, the electron transfer mechanisms from the photosensitizer to the proton reduction catalyst in base metal dyads remain so far unexplored. We study a Fe-Co dyad that exhibits photocatalytic H2 production activity using femtosecond X-ray emission spectroscopy, complemented by ultrafast optical spectroscopy and theoretical time-dependent DFT calculations, to understand the electronic and structural dynamics after photoexcitation and during the subsequent charge transfer process from the FeII photosensitizer to the cobaloxime catalyst. Using this novel approach, the simultaneous measurement of the transient Kalpha X-ray emission at the iron and cobalt K-edges in a two-colour experiment is enabled making it possible to correlate the excited state dynamics to the electron transfer processes. The methodology, therefore, provides a clear and direct spectroscopic evidence of the Fe->Co electron transfer responsible for the proton reduction activity.}}, author = {{Nowakowski, Michał and Huber-Gedert, Marina and Elgabarty, Hossam and Kubicki, Jacek and Kertem, Ahmet and Lindner, Natalia and Khakhulin, Dimitry and Lima, Frederico Alves and Choi, Tae-Kyu and Biednov, Mykola and Piergies, Natalia and Zalden, Peter and Kubicek, Katerina and Rodriguez-Fernandez, Angel and Salem, Mohammad Alaraby and Kühne, Thomas and Gawelda, Wojciech and Bauer, Matthias}}, booktitle = {{arxiv}}, title = {{{Ultrafast two-colour X-ray emission spectroscopy reveals excited state landscape in a base metal dyad}}}, year = {{2023}}, } @inproceedings{42163, abstract = {{The article shows how to learn models of dynamical systems from data which are governed by an unknown variational PDE. Rather than employing reduction techniques, we learn a discrete field theory governed by a discrete Lagrangian density $L_d$ that is modelled as a neural network. Careful regularisation of the loss function for training $L_d$ is necessary to obtain a field theory that is suitable for numerical computations: we derive a regularisation term which optimises the solvability of the discrete Euler--Lagrange equations. Secondly, we develop a method to find solutions to machine learned discrete field theories which constitute travelling waves of the underlying continuous PDE.}}, author = {{Offen, Christian and Ober-Blöbaum, Sina}}, booktitle = {{Geometric Science of Information}}, editor = {{Nielsen, F and Barbaresco, F}}, keywords = {{System identification, discrete Lagrangians, travelling waves}}, location = {{Saint-Malo, Palais du Grand Large, France}}, pages = {{569--579}}, publisher = {{Springer, Cham.}}, title = {{{Learning discrete Lagrangians for variational PDEs from data and detection of travelling waves}}}, doi = {{10.1007/978-3-031-38271-0_57}}, volume = {{14071}}, year = {{2023}}, } @article{29240, abstract = {{The principle of least action is one of the most fundamental physical principle. It says that among all possible motions connecting two points in a phase space, the system will exhibit those motions which extremise an action functional. Many qualitative features of dynamical systems, such as the presence of conservation laws and energy balance equations, are related to the existence of an action functional. Incorporating variational structure into learning algorithms for dynamical systems is, therefore, crucial in order to make sure that the learned model shares important features with the exact physical system. In this paper we show how to incorporate variational principles into trajectory predictions of learned dynamical systems. The novelty of this work is that (1) our technique relies only on discrete position data of observed trajectories. Velocities or conjugate momenta do not need to be observed or approximated and no prior knowledge about the form of the variational principle is assumed. Instead, they are recovered using backward error analysis. (2) Moreover, our technique compensates discretisation errors when trajectories are computed from the learned system. This is important when moderate to large step-sizes are used and high accuracy is required. For this, we introduce and rigorously analyse the concept of inverse modified Lagrangians by developing an inverse version of variational backward error analysis. (3) Finally, we introduce a method to perform system identification from position observations only, based on variational backward error analysis.}}, author = {{Ober-Blöbaum, Sina and Offen, Christian}}, issn = {{0377-0427}}, journal = {{Journal of Computational and Applied Mathematics}}, keywords = {{Lagrangian learning, variational backward error analysis, modified Lagrangian, variational integrators, physics informed learning}}, pages = {{114780}}, publisher = {{Elsevier}}, title = {{{Variational Learning of Euler–Lagrange Dynamics from Data}}}, doi = {{10.1016/j.cam.2022.114780}}, volume = {{421}}, year = {{2023}}, } @article{29236, abstract = {{The numerical solution of an ordinary differential equation can be interpreted as the exact solution of a nearby modified equation. Investigating the behaviour of numerical solutions by analysing the modified equation is known as backward error analysis. If the original and modified equation share structural properties, then the exact and approximate solution share geometric features such as the existence of conserved quantities. Conjugate symplectic methods preserve a modified symplectic form and a modified Hamiltonian when applied to a Hamiltonian system. We show how a blended version of variational and symplectic techniques can be used to compute modified symplectic and Hamiltonian structures. In contrast to other approaches, our backward error analysis method does not rely on an ansatz but computes the structures systematically, provided that a variational formulation of the method is known. The technique is illustrated on the example of symmetric linear multistep methods with matrix coefficients.}}, author = {{McLachlan, Robert and Offen, Christian}}, journal = {{Journal of Geometric Mechanics}}, keywords = {{variational integrators, backward error analysis, Euler--Lagrange equations, multistep methods, conjugate symplectic methods}}, number = {{1}}, pages = {{98--115}}, publisher = {{AIMS Press}}, title = {{{Backward error analysis for conjugate symplectic methods}}}, doi = {{10.3934/jgm.2023005}}, volume = {{15}}, year = {{2023}}, } @article{37654, abstract = {{Recently, Hamiltonian neural networks (HNN) have been introduced to incorporate prior physical knowledge when learning the dynamical equations of Hamiltonian systems. Hereby, the symplectic system structure is preserved despite the data-driven modeling approach. However, preserving symmetries requires additional attention. In this research, we enhance the HNN with a Lie algebra framework to detect and embed symmetries in the neural network. This approach allows to simultaneously learn the symmetry group action and the total energy of the system. As illustrating examples, a pendulum on a cart and a two-body problem from astrodynamics are considered.}}, author = {{Dierkes, Eva and Offen, Christian and Ober-Blöbaum, Sina and Flaßkamp, Kathrin}}, issn = {{1054-1500}}, journal = {{Chaos}}, number = {{6}}, publisher = {{AIP Publishing}}, title = {{{Hamiltonian Neural Networks with Automatic Symmetry Detection}}}, doi = {{10.1063/5.0142969}}, volume = {{33}}, year = {{2023}}, } @inbook{46473, author = {{Dehmel, Lukas}}, booktitle = {{Grundlagen der Erwachsenen- und Weiterbildungsforschung}}, editor = {{Kondratjuk, Maria}}, pages = {{125--127}}, publisher = {{utb}}, title = {{{6.3.2 Medienpädagogische Professionalisierung in der beruflichen Weiterbildung. Eine Studie aus Perspektive der biografischen Medienforschung. Steckbrief zur Dissertation.}}}, year = {{2023}}, } @article{46471, author = {{Unterstell, Rembert}}, journal = {{german research – Magazine of the Deutsche Forschungsgemeinschaft}}, number = {{1}}, pages = {{8--11}}, title = {{{„Allowing the Economy to Breathe Even During the Crisis“ – Interview with Tax Expert Caren Sureth-Sloane}}}, year = {{2023}}, } @proceedings{46474, editor = {{Ade, Larissa and Breiwe, René and Dehmel, Lukas and Wolf, Karsten D. and Rummler, Klaus and Dander, Valentin and Grünberger, Nina and Schiefner-Rohs, Mandy}}, number = {{53}}, title = {{{ENT | GRENZ | UNGEN in der Medienpädagogik. Perspektiven im Anschluss an den 28. Kongress der DGfE}}}, doi = {{doi.org/10.21240/mpaed/53.X}}, year = {{2023}}, } @article{46472, author = {{Dehmel, Lukas and Meister, Dorothee and Gerhardts, Lara}}, journal = {{Zeitschrift MedienPädagogik}}, number = {{53}}, pages = {{55--75}}, title = {{{Die Entgrenzung von Kommunikationskulturen in Lehrpersonenkollegien. Reflexion einer unbeabsichtigten Begleiterscheinung der Arbeit mit Tablets.}}}, doi = {{https://doi.org/10.21240/mpaed/53/2023.06.12.X }}, year = {{2023}}, } @inbook{46475, abstract = {{Dieser Beitrag bietet verschiedene professionelle Perspektiven auf den popmusikalischen Kommunikationsprozesses innerhalb postdigitaler Popmusikjournalismuskulturen. Neben einer wissenschaftlichen Rahmung, Übersicht und Strukturierung des Untersuchungsfelds und des Forschungsstands versammelt der Beitrag multiperspektivische Thesen, die journalistische Praktiken und ihre Reflexionen von Produktion über Distribution und Rezeption/Nutzung bis zur Weiterverarbeitung inklusive Archivierung/Institutionalisierung/Musealisierung aufgreifen und herausstellen. Die aufgestellten Thesen gelten als Aufschlag für die zukünftige Analyse des so fundamentalen und doch auch immer wieder übersehenen Berufsfeldes und seiner Rezeption zwischen Faszination und Exploitation.}}, author = {{Godlewsky, Tanja and Jacke, Christoph and Roenneke, Stefanie and Venker, Thomas}}, booktitle = {{Musik und Internet. Aktuelle Phänomene populärer Kulturen}}, editor = {{Moormann, Peter and Ruth, Nicolas}}, isbn = {{9783658391447}}, issn = {{2626-6199}}, publisher = {{Springer Fachmedien Wiesbaden}}, title = {{{Pop(musik)journalismen zwischen Printmagazin-Krise und postdigitaler Realität – Forschungsüberblick und multiperspektivische Thesen}}}, doi = {{10.1007/978-3-658-39145-4_11}}, year = {{2023}}, } @inproceedings{46476, abstract = {{Abstract. Increasing resource efficiency is a major challenge and affects almost every aspect of social and economic life. The mobility sector in particular is responsible for a large share of primary energy consumption and is increasingly in the focus of public interest. One possibility to adress these challenges is to reduce the vehicle weight by means of lightweight construction technologies such as multi-material systems. These assemblies consist of workpieces with different mechanical and geometrical properties, which poses a major challenge for joining technology. Mechanical joining processes such as semi-tubular self-piercing riveting are often used in the production of these assemblies, but due to their process characteristics, they are rigid and can only react to changing process variables to a limited extent. One way to increase the versatility of self-piercing riveting is to superimpose a tumbling kinematics on the punch. During tumbling, an angular offset of the punch axis to the tool axis is set and the contact area between punch and workpiece is reduced. In this work, investigations were carried out to determine how the tumbling strategy, consisting of the parameters tumbling angle, tumbling onset and tumbling kinematics, affects the material flow of the rivet element. For this purpose, experimental tests are conducted with the typical materials of conventional multi-material systems and the geometric joint formations are determined by means of macrographs. }}, author = {{Wituschek, S. and Elbel, L. and Lechner, M.}}, booktitle = {{Materials Research Proceedings}}, issn = {{2474-395X}}, publisher = {{Materials Research Forum LLC}}, title = {{{Versatile self-piercing riveting with a tumbling superimposed punch}}}, doi = {{10.21741/9781644902479-122}}, year = {{2023}}, } @article{46468, author = {{Lange, Nina Amelie and Schapeler, Timon and Höpker, Jan Philipp and Protte, Maximilian and Bartley, Tim}}, issn = {{2469-9926}}, journal = {{Physical Review A}}, number = {{2}}, publisher = {{American Physical Society (APS)}}, title = {{{Degenerate photons from a cryogenic spontaneous parametric down-conversion source}}}, doi = {{10.1103/physreva.108.023701}}, volume = {{108}}, year = {{2023}}, } @article{46478, author = {{Bartelheimer, Christian and zur Heiden, Philipp and Berendes, Carsten Ingo and Beverungen, Daniel}}, issn = {{0960-085X}}, journal = {{European Journal of Information Systems}}, keywords = {{Library and Information Sciences, Information Systems}}, pages = {{1--34}}, publisher = {{Informa UK Limited}}, title = {{{Designing digital actor engagement platforms for local high streets: an action design research study}}}, doi = {{10.1080/0960085x.2023.2242847}}, year = {{2023}}, } @phdthesis{46482, abstract = {{Ever increasing demands on the performance of microchips are leading to ever more complex semiconductor technologies with ever shrinking feature sizes. Complex applications with high demands on safety and reliability, such as autonomous driving, are simultaneously driving the requirements for test and diagnosis of VLSI circuits. Throughout the life cycle of a microchip, uncertainties occur that affect its timing behavior. For example, weak circuit structures, aging effects, or process variations can lead to a change in the timing behavior of the circuit. While these uncertainties do not necessarily lead to a change of the functional behavior, they can lead to a reliability problem. With modular and hybrid compaction two test instruments are presented in this work that can be used for X-tolerant test response compaction in the built-in Faster-than-At-Speed Test (FAST) which is used to detect uncertainties in VLSI circuits. One challenge for test response compaction during FAST is the high and varying X-rate at the outputs of the circuit under test. By dividing the circuit outputs into test groups and separately compacting these test groups using stochastic compactors, the modular compaction is able to handle these high and varying X-rates. To deal with uncertainties on logic interconnects, a method for distinguishing crosstalk and process variation is presented. In current semiconductor technologies, the number of parasitic coupling capacitances between logic interconnects is growing. These coupling capacitances can lead to crosstalk, which causes increased current flow in the logic interconnects, which in turn can lead to increased electromigration. In the presented method, delay maps describing the timing behavior of the circuit outputs at different operating points are used to train artificial neural networks which classify the tested circuits into fault-free and faulty.}}, author = {{Sprenger, Alexander}}, keywords = {{Testantwortkompaktierung, Prozessvariation, Silicon Lifecycle Management}}, pages = {{xi, 160}}, publisher = {{Universität Paderborn}}, title = {{{Testinstrumente und Testdatenanalyse zur Verarbeitung von Unsicherheiten in Logikblöcken hochintegrierter Schaltungen}}}, doi = {{10.17619/UNIPB/1-1787}}, year = {{2023}}, } @inproceedings{46485, abstract = {{We present a miniaturized pulse shaping device that creates an arbitrary dispersion through the interaction of multiple metasurfaces on less than 2 mm3 volume. For this, a metalens and a grating-metasurface between two silver mirrors are fabricated. The grating contains further phase information to achieve the device's pulse shaping functionality.}}, author = {{Geromel, René and Georgi, Philip and Protte, Maximilian and Bartley, Tim and Huang, Lingling and Zentgraf, Thomas}}, booktitle = {{CLEO: Fundamental Science 2023}}, location = {{San Jose, USA}}, publisher = {{Optica Publishing Group}}, title = {{{Dispersion control with integrated plasmonic metasurfaces}}}, doi = {{10.1364/cleo_fs.2023.fth4d.3}}, year = {{2023}}, } @article{44851, abstract = {{We present the fabrication of strain-free quantum dots in the In0.53Ga0.47As/In0.52Al0.48As-system lattice matched to InP, as future sources for single and entangled photons for long-haul fiber-based quantum communication in the optical C-band. We achieved these quantum dots by local droplet etching via InAl droplets in an In0.52Al0.48As layer and subsequent filling of the holes with In0.53Ga0.47As. Here, we present detailed investigations of the hole morphologies measured by atomic force microscopy. Statistical analysis of a set of nanoholes reveals a high degree of symmetry for nearly half of them when etched at optimized temperatures. Overgrowth with 50–150 nm In0.52Al0.48As increases their diameter and elongates the holes along the [01̄1]-direction. By systematically scanning the parameter space, we were able to fill the holes with In0.53Ga0.47As, and by capping the filled holes and performing photoluminescence measurements, we observe photoluminescence emission in the O-band up into the C-band depending on the filling height of the nanoholes.}}, author = {{Deutsch, D. and Buchholz, C. and Zolatanosha, V. and Jöns, K. D. and Reuter, D.}}, issn = {{2158-3226}}, journal = {{AIP Advances}}, keywords = {{General Physics and Astronomy}}, number = {{5}}, publisher = {{AIP Publishing}}, title = {{{Telecom C-band photon emission from (In,Ga)As quantum dots generated by filling nanoholes in In0.52Al0.48As layers}}}, doi = {{10.1063/5.0147281}}, volume = {{13}}, year = {{2023}}, } @article{46480, author = {{Müller, Hendrik and Weinberger, Christian and Grundmeier, Guido and de los Arcos de Pedro, Maria Teresa}}, issn = {{0368-2048}}, journal = {{Journal of Electron Spectroscopy and Related Phenomena}}, keywords = {{Physical and Theoretical Chemistry, Spectroscopy, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Radiation, Electronic, Optical and Magnetic Materials}}, publisher = {{Elsevier BV}}, title = {{{UV-enhanced environmental charge compensation in near ambient pressure XPS}}}, doi = {{10.1016/j.elspec.2023.147317}}, volume = {{264}}, year = {{2023}}, } @article{46486, author = {{Pfeifer, Florian and Knorr, Lukas and Schlosser, Florian and Marten, Thorsten and Tröster, Thomas}}, issn = {{1848-9257}}, journal = {{Journal of Sustainable Development of Energy, Water and Environment Systems}}, keywords = {{Energy Engineering and Power Technology, Water Science and Technology, Environmental Science (miscellaneous), Renewable Energy, Sustainability and the Environment}}, number = {{3}}, pages = {{1--20}}, publisher = {{SDEWES Centre}}, title = {{{Ecological and Economic Feasibility of Inductive Heating for Sustainable Press Hardening Processes}}}, doi = {{10.13044/j.sdewes.d11.0450}}, volume = {{11}}, year = {{2023}}, }