@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}}, } @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}}, } @inproceedings{45371, author = {{Elsner, Julia and Tenberge, Claudia and Fechner, Sabine}}, booktitle = {{Lernen, Lehren und Forschen in einer digital geprägten Welt}}, editor = {{van Vorst, Helena}}, pages = {{925--928}}, title = {{{Videoanalyse des Modellierprozesses von Grundschüler*innen}}}, volume = {{43}}, year = {{2023}}, } @techreport{46491, author = {{Kundisch, Dennis}}, pages = {{12--13}}, title = {{{#DIGITALENTS - Digital Talents Programm geht in die zweite Runde}}}, volume = {{1}}, year = {{2023}}, } @article{45656, author = {{Kempkes, J. P. and Kreuzhage, K. and Kundisch, Dennis and Seutter, Janina and Weskamp, Christoph}}, journal = {{Kultur Management Network Magazin}}, title = {{{Digitale Transformation im Theater – Mittels Besucherforschung und Entscheidungsunterstützung zur besseren Angebotsgestaltung}}}, volume = {{172}}, year = {{2023}}, } @inproceedings{46502, author = {{Gräßler, Iris and Wiechel, Dominik}}, booktitle = {{2023 18th Annual System of Systems Engineering Conference (SoSe)}}, location = {{Lille}}, publisher = {{IEEE}}, title = {{{Customized impact analyses for technical engineering changes}}}, doi = {{10.1109/sose59841.2023.10178484}}, year = {{2023}}, } @article{46503, abstract = {{ Purpose The purpose of this study is to investigate the manufacturability of Fe-3Si lattice structures and the resulting mechanical properties. This study could lead to the successful processing of squirrel cage conductors (a lattice structure by design) of an induction motor by additive manufacturing in the future. Design/methodology/approach The compression behaviour of two lattice structures where struts are arranged in a face-centred cubic position and vertical edges (FCCZ), and struts are placed at body-centred cubic (BCC) positions, prepared by laser powder bed fusion (LPBF), is explored. The experimental investigations are supported by finite element method (FEM) simulations. Findings The FCCZ lattice structure presents a peak in the stress-strain curve, whereas the BCC lattice structure manifests a plateau. The vertical struts aligned along the compression direction lead to a significant increase in the load-carrying ability of FCCZ lattice structures compared to BCC lattice structures. This results in a peak in the stress-strain curve. However, the BCC lattice structure presents the bending of struts with diagonal struts carrying the major loads with struts near the faceplate receiving the least load. A high concentration of geometrically necessary dislocations (GNDs) near the grain boundaries along cell formation is observed in the microstructure. Originality/value To the best of the authors’ knowledge, this is the first study on additive manufacturing of Fe-3Si lattice structures. Currently, there are no investigations in the literature on the manufacturability and mechanical properties of Fe-3Si lattice structures. }}, author = {{Pramanik, Sudipta and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{1355-2546}}, journal = {{Rapid Prototyping Journal}}, keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}}, number = {{6}}, pages = {{1257--1269}}, publisher = {{Emerald}}, title = {{{Experimental and finite element method investigation on the compression behaviour of FCCZ and BCC lattice structures of additively manufactured Fe-3Si samples}}}, doi = {{10.1108/rpj-06-2022-0190}}, volume = {{29}}, year = {{2023}}, } @article{46507, author = {{Pramanik, Sudipta and Milaege, Dennis and Hein, Maxwell and Andreiev, Anatolii and Schaper, Mirko and Hoyer, Kay-Peter}}, issn = {{1438-1656}}, journal = {{Advanced Engineering Materials}}, keywords = {{Condensed Matter Physics, General Materials Science}}, number = {{14}}, publisher = {{Wiley}}, title = {{{An Experimental and Computational Modeling Study on Additively Manufactured Micro‐Architectured Ti–24Nb–4Zr–8Sn Hollow‐Strut Lattice Structures}}}, doi = {{10.1002/adem.202201850}}, volume = {{25}}, year = {{2023}}, } @unpublished{46504, author = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Schaper, Mirko}}, publisher = {{Elsevier BV}}, title = {{{Powder Bed Fusion of Soft-Magnetic Iron-Silicon-Based Alloys: Advantages and Challenges}}}, doi = {{10.2139/ssrn.4369485}}, year = {{2023}}, } @inproceedings{46514, abstract = {{Purpose: Data integration and applications across knowledge graphs (KGs) rely heavily on the discovery of links between resources within these KGs. Geospatial link discovery algorithms have to deal with millions of point sets containing billions of points. Methodology: To speed up the discovery of geospatial links, we propose COBALT. COBALT combines the content measures with R-tree indexing. The content measures are based on the area, diagonal and distance of the minimum bounding boxes of the polygons which speeds up the process but is not perfectly accurate. We thus propose two polygon splitting approaches for improving the accuracy of COBALT. Findings: Our experiments on real-world datasets show that COBALT is able to speed up the topological relation discovery over geospatial KGs by up to 1.47 × 104 times over state-of-the-art linking algorithms while maintaining an F-Measure between 0.7 and 0.9 depending on the relation. Furthermore, we were able to achieve an F-Measure of up to 0.99 by applying our polygon splitting approaches before applying the content measures. Value: The process of discovering links between geospatial resources can be significantly faster by sacrificing the optimality of the results. This is especially important for real time data-driven applications such as emergency response, location-based services and traffic management. In future work, additional measures, like the location of polygons or the name of the entity represented by the polygon, could be integrated to further improve the accuracy of the results.}}, author = {{Becker, Alexander and Ahmed, Abdullah Fathi Ahmed and Sherif, Mohamed and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{SEMANTiCS}}, keywords = {{ahmed becker dice ngonga sail sherif}}, location = {{Leipzig, Germany}}, title = {{{COBALT: A Content-Based Similarity Approach for Link Discovery over Geospatial Knowledge Graphs}}}, year = {{2023}}, }