@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}}, } @article{46517, author = {{Ahmed, Abdullah Fathi and Sherif, Mohamed Ahmed and Ngomo, Axel-Cyrille Ngonga}}, issn = {{2169-3536}}, journal = {{IEEE Access}}, keywords = {{General Engineering, General Materials Science, General Computer Science, Electrical and Electronic Engineering}}, pages = {{1--1}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{NELLIE: Never-Ending Linking for Linked Open Data}}}, doi = {{10.1109/access.2023.3300694}}, year = {{2023}}, } @inproceedings{46518, abstract = {{Purpose: This study addresses the limitations of current short abstracts of DBpedia entities, which often lack a comprehensive overview due to their creating method (i.e., selecting the first two-three sentences from the full DBpedia abstracts). Methodology: We leverage pre-trained language models to generate abstractive summaries of DBpedia abstracts in six languages (English, French, German, Italian, Spanish, and Dutch). We performed several experiments to assess the quality of generated summaries by language models. In particular, we evaluated the generated summaries using human judgments and automated metrics (Self-ROUGE and BERTScore). Additionally, we studied the correlation between human judgments and automated metrics in evaluating the generated summaries under different aspects: informativeness, coherence, conciseness, and fluency. Findings: Pre-trained language models generate summaries more concise and informative than existing short abstracts. Specifically, BART-based models effectively overcome the limitations of DBpedia short abstracts, especially for longer ones. Moreover, we show that BERTScore and ROUGE-1 are reliable metrics for assessing the informativeness and coherence of the generated summaries with respect to the full DBpedia abstracts. We also find a negative correlation between conciseness and human ratings. Furthermore, fluency evaluation remains challenging without human judgment. Value: This study has significant implications for various applications in machine learning and natural language processing that rely on DBpedia resources. By providing succinct and comprehensive summaries, our approach enhances the quality of DBpedia abstracts and contributes to the semantic web community}}, author = {{Zahera, Hamada Mohamed Abdelsamee and Vitiugin, Fedor and Sherif, Mohamed and Castillo, Carlos and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{SEMANTiCS}}, keywords = {{dice enexa kiam ngonga porque sherif zahera}}, location = {{Leipzig, Germany}}, title = {{{Using Pre-trained Language Models for Abstractive DBpedia Summarization: A Comparative Study}}}, year = {{2023}}, } @misc{45558, abstract = {{Graffiti is an urban phenomenon that is increasingly attracting the interest of the sciences. To the best of our knowledge, no suitable data corpora are available for systematic research until now. The Information System Graffiti in Germany project (Ingrid) closes this gap by dealing with graffiti image collections that have been made available to the project for public use. Within Ingrid, the graffiti images are collected, digitized and annotated. With this work, we aim to support the rapid access to a comprehensive data source on Ingrid targeted especially by researchers. In particular, we present IngridKG, an RDF knowledge graph of annotated graffiti, abides by the Linked Data and FAIR principles. We weekly update IngridKG by augmenting the new annotated graffiti to our knowledge graph. Our generation pipeline applies RDF data conversion, link discovery and data fusion approaches to the original data. The current version of IngridKG contains 460,640,154 triples and is linked to 3 other knowledge graphs by over 200,000 links. In our use case studies, we demonstrate the usefulness of our knowledge graph for different applications.}}, author = {{Sherif, Mohamed and Morim da Silva, Ana Alexandra and Pestryakova, Svetlana and Ahmed, Abdullah Fathi Ahmed and Niemann, Sven and Ngonga Ngomo, Axel-Cyrille}}, publisher = {{LibreCat University}}, title = {{{IngridKG: A FAIR Knowledge Graph of Graffiti}}}, doi = {{10.5281/ZENODO.7560242}}, year = {{2023}}, } @article{46542, abstract = {{Multiprotein adsorption from complex body fluids represents a highly important and complicated phenomenon in medicine. In this work, multiprotein adsorption from diluted human serum at gold and oxidized iron surfaces is investigated at different serum concentrations and pH values. Adsorption-induced changes in surface topography and the total amount of adsorbed proteins are quantified by atomic force microscopy (AFM) and polarization-modulation infrared reflection absorption spectroscopy (PM-IRRAS), respectively. For both surfaces, stronger protein adsorption is observed at pH 6 compared to pH 7 and pH 8. PM-IRRAS furthermore provides some qualitative insights into the pH-dependent alterations in the composition of the adsorbed multiprotein films. Changes in the amide II/amide I band area ratio and in particular side-chain IR absorption suggest that the increased adsorption at pH 6 is accompanied by a change in protein film composition. Presumably, this is mostly driven by the adsorption of human serum albumin, which at pH 6 adsorbs more readily and thereby replaces other proteins with lower surface affinities in the resulting multiprotein film.}}, author = {{Huang, Jingyuan and Qiu, Yunshu and Lücke, Felix and Su, Jiangling and Grundmeier, Guido and Keller, Adrian}}, issn = {{1420-3049}}, journal = {{Molecules}}, keywords = {{Chemistry (miscellaneous), Analytical Chemistry, Organic Chemistry, Physical and Theoretical Chemistry, Molecular Medicine, Drug Discovery, Pharmaceutical Science}}, number = {{16}}, publisher = {{MDPI AG}}, title = {{{Multiprotein Adsorption from Human Serum at Gold and Oxidized Iron Surfaces Studied by Atomic Force Microscopy and Polarization-Modulation Infrared Reflection Absorption Spectroscopy}}}, doi = {{10.3390/molecules28166060}}, volume = {{28}}, year = {{2023}}, } @article{46543, abstract = {{The influence of nanoscale surface topography on protein adsorption is highly important for numerous applications in medicine and technology. Herein, ferritin adsorption at flat and nanofaceted, single-crystalline Al2O3 surfaces is investigated using atomic force microscopy and X-ray photoelectron spectroscopy. The nanofaceted surfaces are generated by the thermal annealing of Al2O3 wafers at temperatures above 1000 °C, which leads to the formation of faceted saw-tooth-like surface topographies with periodicities of about 160 nm and amplitudes of about 15 nm. Ferritin adsorption at these nanofaceted surfaces is notably suppressed compared to the flat surface at a concentration of 10 mg/mL, which is attributed to lower adsorption affinities of the newly formed facets. Consequently, adsorption is restricted mostly to the pattern grooves, where the proteins can maximize their contact area with the surface. However, this effect depends on the protein concentration, with an inverse trend being observed at 30 mg/mL. Furthermore, different ferritin adsorption behavior is observed at topographically similar nanofacet patterns fabricated at different annealing temperatures and attributed to different step and kink densities. These results demonstrate that while protein adsorption at solid surfaces can be notably affected by nanofacet patterns, fine-tuning protein adsorption in this way requires the precise control of facet properties.}}, author = {{Pothineni, Bhanu K. and Kollmann, Sabrina and Li, Xinyang and Grundmeier, Guido and Erb, Denise J. and Keller, Adrian}}, issn = {{1422-0067}}, journal = {{International Journal of Molecular Sciences}}, keywords = {{Inorganic Chemistry, Organic Chemistry, Physical and Theoretical Chemistry, Computer Science Applications, Spectroscopy, Molecular Biology, General Medicine, Catalysis}}, number = {{16}}, publisher = {{MDPI AG}}, title = {{{Adsorption of Ferritin at Nanofaceted Al2O3 Surfaces}}}, doi = {{10.3390/ijms241612808}}, volume = {{24}}, year = {{2023}}, } @inproceedings{46459, author = {{Kouagou, N’Dah Jean and Heindorf, Stefan and Demir, Caglar and Ngomo, Axel-Cyrille Ngonga}}, booktitle = {{NeSy}}, pages = {{430–431}}, publisher = {{CEUR-WS.org}}, title = {{{Neural Class Expression Synthesis (Extended Abstract)}}}, volume = {{3432}}, year = {{2023}}, } @techreport{46534, abstract = {{We study the effect of education on health (hospital stays, number of diagnosed conditions, self-rated poor health, and obesity) over the life-cycle in Germany, using compulsory schooling reforms as a source of exogenous variation. Our results suggest a positive correlation of health and education which increases over the life-cycle. We do not, however, find any positive local average treatment effects of an additional year of schooling on health or health care utilization for individuals up to age 79. An exception is obesity, where positive effects of schooling start to be visible around age 60 and become very large in age group 75-79. The results in age group 75-79 need to be interpreted with caution, however, due to small sample size and possible problems of attrition.}}, author = {{Schmitz, Hendrik and Tawiah, Beatrice Baaba}}, keywords = {{Education, health, life-cycle effects, compulsory schooling}}, publisher = {{RWI - Leibniz-Institut für Wirtschaftsforschung, Ruhr-University Bochum, TU Dortmund University, University of Duisburg-Essen}}, title = {{{Life-cycle health effects of compulsory schooling}}}, volume = {{1006}}, year = {{2023}}, }