TY - CONF AB - The creation of an RDF knowledge graph for a particular application commonly involves a pipeline of tools that transform a set ofinput data sources into an RDF knowledge graph in a process called dataset augmentation. The components of such augmentation pipelines often require extensive configuration to lead to satisfactory results. Thus, non-experts are often unable to use them. Wepresent an efficient supervised algorithm based on genetic programming for learning knowledge graph augmentation pipelines of arbitrary length. Our approach uses multi-expression learning to learn augmentation pipelines able to achieve a high F-measure on the training data. Our evaluation suggests that our approach can efficiently learn a larger class of RDF dataset augmentation tasks than the state of the art while using only a single training example. Even on the most complex augmentation problem we posed, our approach consistently achieves an average F1-measure of 99% in under 500 iterations with an average runtime of 16 seconds AU - Dreßler, Kevin AU - Sherif, Mohamed AU - Ngonga Ngomo, Axel-Cyrille ID - 31806 KW - 2022 RAKI SFB901 deer dice kevin knowgraphs limes ngonga sherif simba T2 - Proceedings of the 33rd ACM Conference on Hypertext and Hypermedia TI - ADAGIO - Automated Data Augmentation of Knowledge Graphs Using Multi-expression Learning ER - TY - JOUR AU - Redder, Adrian AU - Ramaswamy, Arunselvan AU - Karl, Holger ID - 32854 IS - 13 JF - IFAC-PapersOnLine TI - Practical Network Conditions for the Convergence of Distributed Optimization VL - 55 ER - TY - CONF AU - Hansmeier, Tim AU - Brede, Mathis AU - Platzner, Marco ID - 33253 T2 - GECCO '22: Proceedings of the Genetic and Evolutionary Computation Conference Companion TI - XCS on Embedded Systems: An Analysis of Execution Profiles and Accelerated Classifier Deletion ER - TY - CONF AU - Chen, Wei-Fan AU - Chen, Mei-Hua AU - Mudgal, Garima AU - Wachsmuth, Henning ID - 33274 T2 - Proceedings of the 9th Workshop on Argument Mining (ArgMining 2022) TI - Analyzing Culture-Specific Argument Structures in Learner Essays ER - TY - CONF AU - Maack, Marten AU - Pukrop, Simon AU - Rasmussen, Anna Rodriguez ED - Chechik, Shiri ED - Navarro, Gonzalo ED - Rotenberg, Eva ED - Herman, Grzegorz ID - 33491 T2 - 30th Annual European Symposium on Algorithms, ESA 2022, September 5-9, 2022, Berlin/Potsdam, Germany TI - (In-)Approximability Results for Interval, Resource Restricted, and Low Rank Scheduling VL - 244 ER - TY - GEN AB - We study the consequences of modeling asymmetric bargaining power in two-person bargaining problems. Comparing application of an asymmetric version of a bargaining solution to an upfront modification of the disagreement point, the resulting distortion crucially depends on the bargaining solution concept. While for the Kalai-Smorodinsky solution weaker players benefit from modifying the disagreement point, the situation is reversed for the Nash bargaining solution. There, weaker players are better off in the asymmetric bargaining solution. When comparing application of the asymmetric versions of the Nash and the Kalai-Smorodinsky solutions, we demonstrate that there is an upper bound for the weight of a player, so that she is better off with the Nash bargaining solution. This threshold is ultimately determined by the relative utilitarian bargaining solution. From a mechanism design perspective, our results provide valuable information for a social planner, when implementing a bargaining solution for unequally powerful players. AU - Haake, Claus-Jochen AU - Streck, Thomas ID - 32106 KW - Asymmetric bargaining power KW - Nash bargaining solution KW - Kalai-Smorodinsky bargaining solution TI - Distortion through modeling asymmetric bargaining power VL - 148 ER - TY - GEN AU - Grynko, Yevgen AU - Shkuratov, Yuriy AU - Alhaddad, Samer AU - Förstner, Jens ID - 34136 KW - tet_topic_scattering TI - Light backscattering from numerical analog of planetary regoliths ER - TY - JOUR AB - How can Knowledge In/Equity be addressed in qualitative research by taking the idea of Open Science into account? Two projects from the Open Science Fellows Programme by Wikimedia Deutschland will be used to illustrate how Open Science practices can succeed in qualitative research, thereby reducing In/Equity. In this context, In/Equity is considered as a fair and equal representation of people, their knowledge and insights and comprehends questions about how epistemic, structural, institutional and personal biases generate and shape knowledge as guidance. Three questions guide this approach: firstly, what do we understand by In/Equity in the context of knowledge production in these projects? Secondly, who will be involved in knowledge generation and to what extent will they be valued or unvalued? Thirdly, how can data be made accessible for re-use to enable true participation and sharing? AU - Steinhardt, Isabel AU - Kruschick, Felicitas ID - 34132 JF - Research Ideas and Outcomes KW - Open Science KW - Knowledge Equity KW - Qualitative Methods SN - 2367-7163 TI - Knowledge Equity and Open Science in qualitative research – Practical research considerations VL - 8 ER - TY - JOUR AB - Subwavelength dielectric resonators assembled into metasurfaces have become a versatile tool for miniaturizing optical components approaching the nanoscale. An important class of metasurface functionalities is associated with asymmetry in both the generation and transmission of light with respect to reversals of the positions of emitters and receivers. The nonlinear light–matter interaction in metasurfaces offers a promising pathway towards miniaturization of the asymmetric control of light. Here we demonstrate asymmetric parametric generation of light in nonlinear metasurfaces. We assemble dissimilar nonlinear dielectric resonators into translucent metasurfaces that produce images in the visible spectral range on being illuminated by infrared radiation. By design, the metasurfaces produce different and completely independent images for the reversed direction of illumination, that is, when the positions of the infrared emitter and the visible light receiver are exchanged. Nonlinearity-enabled asymmetric control of light by subwavelength resonators paves the way towards novel nanophotonic components via dense integration of large quantities of nonlinear resonators into compact metasurface designs. AU - Kruk, Sergey S. AU - Wang, Lei AU - Sain, Basudeb AU - Dong, Zhaogang AU - Yang, Joel AU - Zentgraf, Thomas AU - Kivshar, Yuri ID - 32088 JF - Nature Photonics KW - Atomic and Molecular Physics KW - and Optics KW - Electronic KW - Optical and Magnetic Materials SN - 1749-4885 TI - Asymmetric parametric generation of images with nonlinear dielectric metasurfaces VL - 16 ER - TY - CONF AB - In this paper, machine learning techniques will be used to classify different PCB layouts given their electromagnetic frequency spectra. These spectra result from a simulated near-field measurement of electric field strengths at different locations. Measured values consist of real and imaginary parts (amplitude and phase) in X, Y and Z directions. Training data was obtained in the time domain by varying transmission line geometries (size, distance and signaling). It was then transformed into the frequency domain and used as deep neural network input. Principal component analysis was applied to reduce the sample dimension. The results show that classifying different designs is possible with high accuracy based on synthetic data. Future work comprises measurements of real, custom-made PCB with varying parameters to adapt the simulation model and also test the neural network. Finally, the trained model could be used to give hints about the error’s cause when overshooting EMC limits. AU - Maalouly, Jad AU - Hemker, Dennis AU - Hedayat, Christian AU - Rückert, Christian AU - Kaufmann, Ivan AU - Olbrich, Marcel AU - Lange, Sven AU - Mathis, Harald ID - 34140 KW - emc KW - pcb KW - electronic system development KW - machine learning KW - neural network T2 - 2022 Kleinheubach Conference TI - AI Assisted Interference Classification to Improve EMC Troubleshooting in Electronic System Development ER - TY - CHAP AU - Hagengruber, Ruth Edith ED - Banse, Gerhard ED - Fuchs-Kittowski, Klaus ID - 34108 T2 - Sitzungsberichte der Leibniz-Sozietät der Wissenschaften 150/151, Jahrgang 2022: „Cyberscience – Wissenschaftsforschung und Informatik. Digitale Medien und die Zukunft der Kultur wissenschaftlicher Tätigkeit. Arbeitskreis „Emergente Systeme/Informatik und Gesellschaft“ der Leibniz-Sozietät der Wissenschaften zu Berlin in Kooperation mit der Gesellschaft für Wissenschaftsforschung“ TI - Die „dritte Wissensdimension“. Eine Epistemologie für eine neue Wissenswelt ER - TY - CHAP AB - This work addresses the automatic resolution of software requirements. In the vision of On-The-Fly Computing, software services should be composed on demand, based solely on natural language input from human users. To enable this, we build a chatbot solution that works with human-in-the-loop support to receive, analyze, correct, and complete their software requirements. The chatbot is equipped with a natural language processing pipeline and a large knowledge base, as well as sophisticated dialogue management skills to enhance the user experience. Previous solutions have focused on analyzing software requirements to point out errors such as vagueness, ambiguity, or incompleteness. Our work shows how apps can collaborate with users to efficiently produce correct requirements. We developed and compared three different chatbot apps that can work with built-in knowledge. We rely on ChatterBot, DialoGPT and Rasa for this purpose. While DialoGPT provides its own knowledge base, Rasa is the best system to combine the text mining and knowledge solutions at our disposal. The evaluation shows that users accept 73% of the suggested answers from Rasa, while they accept only 63% from DialoGPT or even 36% from ChatterBot. AU - Kersting, Joschka AU - Ahmed, Mobeen AU - Geierhos, Michaela ED - Stephanidis, Constantine ED - Antona, Margherita ED - Ntoa, Stavroula ID - 32179 KW - On-The-Fly Computing KW - Chatbot KW - Knowledge Base SN - 1865-0929 T2 - HCI International 2022 Posters TI - Chatbot-Enhanced Requirements Resolution for Automated Service Compositions VL - 1580 ER - TY - CONF AU - Otroshi, Mortaza AU - Meschut, Gerson ID - 34152 TI - Methodenentwicklung zur Verbesserung der Schädigungsmodellierung in der numerischen 3D-Belastungssimulation mechanischer Fügeverfahren unter Berücksichtigung der fügeinduzierten Vorbeanspruchung ER - TY - CONF AU - Krauter, Stefan AU - Bendfeld, Jörg ID - 34155 T2 - Proceedings of the 8th World Conference on Photovoltaik Energy Conversion TI - Microinverter PV Systems: New Efficiency Rankings and Formula for Energy Yield Assessment for any PV Panel Size at different Microinverter types ER - TY - CONF AU - Kakande, Josephine Nakato AU - Philipo, Godiana Hagile AU - Krauter, Stefan ID - 34156 T2 - Proceedings of the 8th World Conference on Photovoltaik Energy Conversion TI - Optimal Design of a Semi Grid-Connected PV System for a Site in Lwak, Kenya Using HOMER ER - TY - GEN AU - Otroshi, Mortaza AU - Meschut, Gerson ID - 34153 TI - Schädigungsmodellierung von Hilfsfügeelementen beim mechanischen Fügen von Stahlwerkstoffen ER - TY - THES AB - Wettstreit zwischen der Entwicklung neuer Hardwaretrojaner und entsprechender Gegenmaßnahmen beschreiten Widersacher immer raffiniertere Wege um Schaltungsentwürfe zu infizieren und dabei selbst fortgeschrittene Test- und Verifikationsmethoden zu überlisten. Abgesehen von den konventionellen Methoden um einen Trojaner in eine Schaltung für ein Field-programmable Gate Array (FPGA) einzuschleusen, können auch die Entwurfswerkzeuge heimlich kompromittiert werden um einen Angreifer dabei zu unterstützen einen erfolgreichen Angriff durchzuführen, der zum Beispiel Fehlfunktionen oder ungewollte Informationsabflüsse bewirken kann. Diese Dissertation beschäftigt sich hauptsächlich mit den beiden Blickwinkeln auf Hardwaretrojaner in rekonfigurierbaren Systemen, einerseits der Perspektive des Verteidigers mit einer Methode zur Erkennung von Trojanern auf der Bitstromebene, und andererseits derjenigen des Angreifers mit einer neuartigen Angriffsmethode für FPGA Trojaner. Für die Verteidigung gegen den Trojaner ``Heimtückische LUT'' stellen wir die allererste erfolgreiche Gegenmaßnahme vor, die durch Verifikation mittels Proof-carrying Hardware (PCH) auf der Bitstromebene direkt vor der Konfiguration der Hardware angewendet werden kann, und präsentieren ein vollständiges Schema für den Entwurf und die Verifikation von Schaltungen für iCE40 FPGAs. Für die Gegenseite führen wir einen neuen Angriff ein, welcher bösartiges Routing im eingefügten Trojaner ausnutzt um selbst im fertigen Bitstrom in einem inaktiven Zustand zu verbleiben: Hierdurch kann dieser neuartige Angriff zur Zeit weder von herkömmlichen Test- und Verifikationsmethoden, noch von unserer vorher vorgestellten Verifikation auf der Bitstromebene entdeckt werden. AU - Ahmed, Qazi Arbab ID - 29769 KW - FPGA Security KW - Hardware Trojans KW - Bitstream-level Trojans KW - Bitstream Verification TI - Hardware Trojans in Reconfigurable Computing ER - TY - CONF AB - Within innovation management, choosing the best fitting product idea is the most important decision point. The future existence and success of the organization is depending on selected product ideas. To find the best fitting idea for an organization, it needs evaluation criteria representing the organizations mission Therefore, this study focuses on a holistic overview about evaluation criteria and on supporting organizations in the process to select its individual evaluation criteria. Based on a literature study, existing approaches regarding evaluation criteria in product idea selection are identified and a list of evaluation criteria is reworked. Using the list of evaluation criteria, a prioritization method is created. Within an interview with experts in innovation management, the method is discussed regarding usability and the level of assistance in product idea selection. The developed criteria can be used directly by innovation manager and industrial practitioners to evaluate potential product ideas. AU - Gräßler, Iris AU - Koch, Anna-Sophie ID - 34166 KW - innovation management KW - evaluation criteria KW - idea selection KW - idea evaluation KW - meta-study SN - 978-952-335-694-8 T2 - XXXIII Proceedings of the ISPIM Innovation Conference TI - Evaluation Criteria in Product Idea Selection Decisions ER - TY - THES AB - Anforderungsänderungen sind ein wesentlicher Grund für Ineffizienzen und Projektfehlschläge in der Entwicklung komplexer technischer Systeme. Proaktives Management von Anforderungsänderungen hat das Potenzial, den Umgang mit Anforderungsänderungen effizienter zu gestalten. Dafür ist ein systematischer Ansatz erforderlich, der eine ganzheitliche Bewertung und Handhabung des Änderungsrisikos im industriellen Entwicklungskontext ermöglicht. Im Rahmen dieser Dissertation wird mit der ProMaRC-Methodik ein neuartiger Ansatz für das proaktive Management von Anforderungsänderungen vorgestellt. Die Methodik wurde in enger Zusammenarbeit mit Industrieanwender:innen aus der Automobilindustrie entwickelt und anhand von fünf Fallstudien validiert. Mittels automatisierter Abhängigkeitsanalyse auf Grundlage künstlicher Intelligenz wird der Anwendungsaufwand gegenüber bestehenden Ansätzen reduziert. Die teilautomatisierte Bewertung und Handhabung der Änderungswahrscheinlichkeit und -auswirkung erfolgt anhand eines modifizierten PageRank-Algorithmus und umfasst erstmalig alle für die Risikoanalyse relevanten Einflussfaktoren. Die Validierung belegt, dass durch die ProMaRC-Methodik eine überzeugende Kombination aus praxistauglichem Anwendungsaufwand und Vollständigkeit der Analyse erzielt wird. Damit erschließt diese Dissertation das bisher kaum beachtete Forschungsfeld des proaktiven Managements von Anforderungsänderungen und fördert eine effizientere Produktentwicklung. AU - Oleff, Christian ID - 34174 TI - Proaktives Management von Anforderungsänderungen in der Entwicklung komplexer technischer Systeme VL - 406 ER - TY - CONF AB - This paper aims at discussing past limitations set in sentiment analysis research regarding explicit and implicit mentions of opinions. Previous studies have regularly neglected this question in favor of methodical research on standard-datasets. Furthermore, they were limited to linguistically less-diverse domains, such as commercial product reviews. We face this issue by annotating a German-language physician review dataset that contains numerous implicit, long, and complex statements that indicate aspect ratings, such as the physician’s friendliness. We discuss the nature of implicit statements and present various samples to illustrate the challenge described. AU - Kersting, Joschka AU - Bäumer, Frederik Simon ED - Kersting, Joschka ID - 31054 KW - Sentiment analysis KW - Natural language processing KW - Aspect phrase extraction T2 - Proceedings of the Fourteenth International Conference on Pervasive Patterns and Applications (PATTERNS 2022): Special Track AI-DRSWA: Maturing Artificial Intelligence - Data Science for Real-World Applications TI - Implicit Statements in Healthcare Reviews: A Challenge for Sentiment Analysis ER - TY - JOUR AU - Hoyer, Britta AU - De Jaegher, Kris ID - 31881 JF - International Journal of Game Theory TI - Network Disruption and the Common-Enemy Effect ER - TY - GEN AB - BloKK-Beitrag für das ZeKK, 03.12.2022 AU - Lebock, Sarah ID - 34187 TI - Blogpost "Von der Grundstimmung als philosophischer Ausgangspunkt" ER - TY - JOUR AB - Far-field multi-speaker automatic speech recognition (ASR) has drawn increasing attention in recent years. Most existing methods feature a signal processing frontend and an ASR backend. In realistic scenarios, these modules are usually trained separately or progressively, which suffers from either inter-module mismatch or a complicated training process. In this paper, we propose an end-to-end multi-channel model that jointly optimizes the speech enhancement (including speech dereverberation, denoising, and separation) frontend and the ASR backend as a single system. To the best of our knowledge, this is the first work that proposes to optimize dereverberation, beamforming, and multi-speaker ASR in a fully end-to-end manner. The frontend module consists of a weighted prediction error (WPE) based submodule for dereverberation and a neural beamformer for denoising and speech separation. For the backend, we adopt a widely used end-to-end (E2E) ASR architecture. It is worth noting that the entire model is differentiable and can be optimized in a fully end-to-end manner using only the ASR criterion, without the need of parallel signal-level labels. We evaluate the proposed model on several multi-speaker benchmark datasets, and experimental results show that the fully E2E ASR model can achieve competitive performance on both noisy and reverberant conditions, with over 30% relative word error rate (WER) reduction over the single-channel baseline systems. AU - Zhang, Wangyou AU - Chang, Xuankai AU - Boeddeker, Christoph AU - Nakatani, Tomohiro AU - Watanabe, Shinji AU - Qian, Yanmin ID - 33669 JF - IEEE/ACM Transactions on Audio, Speech, and Language Processing SN - Print ISSN: 2329-9290 Electronic ISSN: 2329-9304 TI - End-to-End Dereverberation, Beamforming, and Speech Recognition in A Cocktail Party ER - TY - JOUR AB - AbstractComprehensive data understanding is a key success driver for data analytics projects. Knowing the characteristics of the data helps a lot in selecting the appropriate data analysis techniques. Especially in data-driven product planning, knowledge about the data is a necessary prerequisite because data of the use phase is very heterogeneous. However, companies often do not have the necessary know-how or time to build up solid data understanding in connection with data analysis. In this paper, we develop a methodology to organize and categorize and thus understand use phase data in a way that makes it accessible to general data analytics workflows, following a design science research approach. We first present a knowledge base that lists typical use phase data from a product planning view. Second, we develop a taxonomy based on standard literature and real data objects, which covers the diversity of the data considered. The taxonomy provides 8 dimensions that support classification of use phase data and allows to capture data characteristics from a data analytics view. Finally, we combine both views by clustering the objects of the knowledge base according to the taxonomy. Each of the resulting clusters covers a typical combination of analytics relevant characteristics occurring in practice. By abstracting from the diversity of use phase data into artifacts with manageable complexity, our approach provides guidance to choose appropriate data analysis and AI techniques. AU - Panzner, Melina AU - von Enzberg, Sebastian AU - Meyer, Maurice AU - Dumitrescu, Roman ID - 34197 JF - Journal of the Knowledge Economy KW - Economics and Econometrics SN - 1868-7865 TI - Characterization of Usage Data with the Help of Data Classifications ER - TY - JOUR AB - Mounting sensors in disk stack separators is often a major challenge due to the operating conditions. However, a process cannot be optimally monitored without sensors. Virtual sensors can be a solution to calculate the sought parameters from measurable values. We measured the vibrations of disk stack separators and applied machine learning (ML) to detect whether the separator contains only water or whether particles are also present. We combined seven ML classification algorithms with three feature engineering strategies and evaluated our model successfully on vibration data of an experimental disk stack separator. Our experimental results demonstrate that random forest in combination with manual feature engineering using domain specific knowledge about suitable features outperforms all other models with an accuracy of 91.27 %. AU - Merkelbach, Silke AU - Afroze, Lameya AU - Janssen, Nils AU - von Enzberg, Sebastian AU - Kühn, Arno AU - Dumitrescu, Roman ID - 34196 JF - Vibroengineering PROCEDIA KW - General Medicine SN - 2345-0533 TI - Using vibration data to classify conditions in disk stack separators VL - 46 ER - TY - CHAP AU - Hobscheidt, Daniela AU - Menzefricke, Jörn Steffen AU - Gabriel, Stefan AU - Kühn, Arno AU - Dumitrescu, Roman ID - 34195 SN - 9783658383787 T2 - Praxishandbuch Robotic Process Automation (RPA) TI - Soziotechnische Herausforderungen bei der Einführung von RPA managen ER - TY - CHAP AU - Bansmann, Michael AU - Dumitrescu, Roman AU - Fechtelpeter, Christian ID - 34193 SN - 2523-3637 T2 - Gestaltung digitalisierter Arbeitswelten TI - Transfer von Arbeit 4.0-Anwendungsszenarien ER - TY - CHAP AU - Brock, Jonathan AU - von Enzberg, Sebastian AU - Kühn, Arno AU - Dumitrescu, Roman ID - 34194 SN - 9783658383787 T2 - Praxishandbuch Robotic Process Automation (RPA) TI - Nutzung von Process Mining in RPA-Projekten ER - TY - JOUR AB - Praxeologische Kompetenzansätze verstehen Kompetenz als sozial erlernt und folglich als relativ zum sozialen Kontext. Damit einher geht die Frage, wie solche praxeologisch gerahmten Kompetenzen eigentlich unabhängig von der sie hervorbringenden Praxis evaluiert werden können – und eben dadurch erst für einen breiteren Kompetenzdiskurs fruchtbar sind. Die Dokumentarische Evaluationsforschung bietet hierzu erste Anhaltspunkte, offenbart aber auch Grenzen, die mit dem Evaluationsverständnis zusammenhängen, sich jedoch in der Forschungspraxis so nicht finden lassen. Aus der Differenz zwischen Methode und Praxis dokumentarischer Evaluation lässt sich formulieren, wie eine praxeologische Evaluation gestaltet werden könnte. Dabei spielt die Formulierung von Referenzrahmen eine zentrale Rolle, welche einerseits der zu evaluierenden Praktik external sein, andererseits praktisch formuliert werden müssen, damit sie soziale Praktiken jenseits ihrer eigenen Sinnhaftigkeit evaluativ (er-)fassen können. AU - Bloh, Thiemo ID - 34200 IS - 02 JF - Zeitschrift für Evaluation KW - Strategy and Management KW - Applied Psychology KW - Social Sciences (miscellaneous) KW - Education KW - Communication KW - Statistics and Probability SN - 1619-5515 TI - Rekonstruktive Evaluationsforschung im Kontext praxeologischer Kompetenzdiskurse. Kritische Reflexionen und konzeptionelle Überlegungen zur Dokumentarischen Evaluationsforschung VL - 2022 ER - TY - JOUR AU - Bloh, Thiemo AU - Caruso, Carina ID - 34198 JF - die hochschullehre TI - Ein kritisch-multiperspektivischer Blick auf Forschendes Lernen in der Lehrkräftebildung. Fragen, Erwägungen und Rekonstruktionen. VL - 8 ER - TY - JOUR AU - Bloh, Thiemo ID - 34199 IS - 6 JF - Zeitschrift für Pädagogik TI - Grundlagentheoretische Differenzen in der Lehrkräftekooperationsforschung VL - 68 ER - TY - JOUR AB - AlSi casting alloys combine excellent castability with high strength. Hence, this group of alloys is often used in the automotive sector. The challenge for this application is the brittle character of these alloys which leads to cracks during joint formation when mechanical joining technologies are used. A rise in ductility can be achieved by a considerable increase in the solidification rate which results in grain refinement. High solidification rates can be realized in twin–roll casting (TRC) by water-cooled rolls. Therefore, a hypoeutectic EN AC–AlSi9 (for European Norm - aluminum cast product) is manufactured by the TRC process and analyzed. Subsequently, joining investigations are performed on castings in as-cast and heat-treated condition using the self-piercing riveting process considering the joint formation and the load-bearing capacity. Due to the fine microstructure, the crack initiation can be avoided during joining, while maintaining the joining parameters, especially by specimens in heat treatment conditions. Furthermore, due to the extremely fine microstructure, the load-bearing capacity of the joint can be significantly increased in terms of the maximum load-bearing force and the energy absorbed. AU - Neuser, Moritz AU - Kappe, Fabian AU - Ostermeier, Jakob AU - Krüger, Jan Tobias AU - Bobbert, Mathias AU - Meschut, Gerson AU - Schaper, Mirko AU - Grydin, Olexandr ID - 34207 IS - 10 JF - Advanced Engineering Materials KW - Condensed Matter Physics KW - General Materials Science SN - 1438-1656 TI - Mechanical Properties and Joinability of AlSi9 Alloy Manufactured by Twin‐Roll Casting VL - 24 ER - TY - CONF AU - Bloh, Thiemo ID - 34203 TI - Was bedeutet Post-Digitalität? – Universitäre Lehrpraktiken zwischen situativer Anforderung und habitueller Prägung ER - TY - CONF AU - Bloh, Thiemo ID - 34201 TI - AussteigerInnen – Fluchtbewegungen in der LehrerInnenbiographie ER - TY - CONF AU - Bloh, Thiemo ID - 34202 TI - „Referenzrahmen“ als gewinnbringendes Konstrukt im Kontext Dokumentarischer Evaluationsforschung!? ER - TY - CONF AU - Bloh, Thiemo ID - 34204 TI - The Deconstruction of Professionalism ER - TY - CHAP AB - Nowadays, clinching is a widely used joining technique, where sheets are joined by pure deformation to create an interlock without the need for auxiliary parts. This leads to advantages such as reduced joining time and manufacturing costs. On the other hand, the joint strength solely relies on directed material deformation, which renders an accurate material modelling essential to reliably predict the joint forming. The formation of the joint locally involves large plastic strains and possibly complex non-proportional loading paths, as typical of many metal forming applications. Consequently, a finite plasticity formulation is utilised incorporating a Chaboche–Rousselier kinematic hardening law to capture the Bauschinger effect. Material parameters are identified from tension–compression tests on miniature spec- imens for the dual-phase steel HCT590X. The resulting material model is implemented in LS-Dyna to study the locally diverse loading paths and give a quantitative statement on the importance of kinematic hardening for clinching. It turns out that the Bauschinger effect mainly affects the springback of the sheets and has a smaller effect on the joint forming itself. AU - Friedlein, Johannes AU - Mergheim, Julia AU - Steinmann, Paul ID - 34211 KW - Clinching KW - Material modelling KW - Kinematic hardening KW - Parameter identification KW - Bauschinger effect SN - 2367-1181 T2 - The Minerals, Metals & Materials Series TI - Influence of Kinematic Hardening on Clinch Joining of Dual-Phase Steel HCT590X Sheet Metal ER - TY - JOUR AB - In this paper, a study based on experimental and numerical simulations is performed to analyze fatigue cracks in clinched joints. An experimental investigation is conducted to determine the failure modes of clinched joints under cyclic loading at different load amplitudes with single-lap shear tests. In addition, numerical FEM simulations of clinching process and subsequent shear loading are performed to support the experimental investigations by analyzing the state of stresses at the location of failure. An attempt is made to explain the location of crack initiation in the experiments using evaluation variables such as contact shear stress and maximum principal stress. AU - Ewenz, L. AU - Bielak, Christian Roman AU - Otroshi, Mortaza AU - Bobbert, Mathias AU - Meschut, Gerson AU - Zimmermann, M. ID - 34213 IS - 2-3 JF - Production Engineering KW - Industrial and Manufacturing Engineering KW - Mechanical Engineering SN - 0944-6524 TI - Numerical and experimental identification of fatigue crack initiation sites in clinched joints VL - 16 ER - TY - CHAP AB - Force–displacement measurements and micrograph analyses are commonly used methods to validate numerical models of clinching processes. However, these methods often lead to resetting of elastic deformations and crack- closing after unloading. In contrast, the in situ computed tomography (CT) can provide three-dimensional images of the clinch point under loading conditions. In this paper, the potential of the in situ investigation of a clinching process as validation method is analyzed. For the in situ testing, a tailored test set-up featuring a beryllium cylinder for load-bearing and clinching tools made from ultra-high-strength titanium and Si3N4 are used. In the experiments, the clinching of two aluminum sheets is interrupted at specific process steps in order to perform the CT scans. It is shown that in situ CT visualizes the inner geometry of the joint at high precision and that this method is suitable to validate numerical models. AU - Köhler, Daniel AU - Kupfer, Robert AU - Troschitz, Juliane AU - Gude, Maik ID - 34212 KW - Clinching KW - Non-destructive testing KW - Computed tomography KW - In situ CT SN - 2367-1181 T2 - The Minerals, Metals & Materials Series TI - Clinching in In Situ CT—A Novel Validation Method for Mechanical Joining Processes ER - TY - JOUR AB - Resource-saving and sustainable production is becoming increasingly important regarding social, political and economic aspects, thus making the use of lightweight-construction technologies a current trend. For this reason, multi-material-systems made of high-strength steel and aluminium as well as metal and fibre-reinforced plastics gain in importance. However, different material properties, e.g. stiffness, thermal expansion coefficients or chemical incompatibilities, are challenging for conventional joining technologies. Joining by cold formed pin structures has shown to have high potential for joining multi-material-systems. These pins can be joined either by direct pin pressing into an unperforated joining partner or by caulking, where the pins are inserted through a pre-punched joining partner and the pin head is upset, resulting in a form-fit joint. Usually, cylindrical pins are used for joining. However, non-rotationally symmetrical pin geometries offer the possibility of introducing a predetermined breaking point or reinforcing a connection in the principal force direction. In this work, cylindrical pins as well as non-rotationally symmetrical pin geometries, such as polygonal and oval pin structures, are cold extruded from the sheet metal plane of an HCT590X+Z dual phase steel and joined in the next step with an EN AW-6014 aluminium using direct pin pressing. Since the formation of an undercut has an crucial influence on the joint strength, the investigations will be focused on the resulting joint geometry. In addition, the effect of different pin heights will be examined to analyse the joint formation at different levels of compression of the pin structures. Finally, the joints are evaluated regarding their joint strength in tensile shear tests and cross tension tests. Here the flow resistance of the geometry used as well as the pin height and thus the strain hardening of the pin base during the extrusion of the pins play a decisive role for the shear strength. AU - Römisch, David AU - Kraus, Martin AU - Merklein, Marion ID - 34219 IS - 6 JF - Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications KW - Mechanical Engineering KW - General Materials Science SN - 1464-4207 TI - Investigation of the influence of formed, non-rotationally symmetrical pin geometries and their effect on the joint quality of steel and aluminium sheets by direct pin pressing VL - 236 ER - TY - JOUR AB - In this study, quasi-unidirectional continuous fiber reinforced thermoplastics (CFRTs) are joined with metal sheets via cold formed cylindrical, elliptical and polygonal pin structures which are directly pressed into the CFRT component after local infrared heating. In comparison to already available studies, the unique novelty is the use of non-rotational symmetric pin structures for the CFRT/metal hybrid joining. Thus, a variation in the fiber orientation in the CFRT component as well as a variation in the non-rotational symmetric pins’ orientation in relation to the sample orientation is conducted. The created samples are consequently mechanically tested via single lap shear experiments in a quasi-static state. Finally, the failure behavior of the single lap shear samples is investigated with the help of microscopic images and detailed photographs. In the single lap shear tests, it could be shown that non-rotational symmetric pin structures lead to an increase in maximum testing forces of up to 74% when compared to cylindrical pins. However, when normalized to the pin foot print related joint strength, only one polygonal pin variation showed increased joint strength in comparison to cylindrical pin structures. The investigation of the failure behavior showed two distinct failure modes. The first failure mode was failure of the CFRT component due to an exceedance of the maximum bearing strength of the pin-hole leading to significant damage in the CFRT component. The second failure mode was pin-deflection due to the applied testing load and a subsequent pin extraction from the CFRT component resulting in significantly less visible damage in the CFRT component. Generally, CFRT failure is more likely with a fiber orientation of 0° in relation to the load direction while pin extraction typically occurs with a fiber orientation of 90°. It is assumed that for future investigations, pin structures with an undercutting shape that creates an interlocking joint could counteract the tendency for pin-extraction and consequently lead to increased maximum joint strengths. AU - Popp, Julian AU - Römisch, David AU - Merklein, Marion AU - Drummer, Dietmar ID - 34223 IS - 10 JF - Applied Sciences KW - Fluid Flow and Transfer Processes KW - Computer Science Applications KW - Process Chemistry and Technology KW - General Engineering KW - Instrumentation KW - General Materials Science SN - 2076-3417 TI - Joining of CFRT/Steel Hybrid Parts via Direct Pressing of Cold Formed Non-Rotational Symmetric Pin Structures VL - 12 ER - TY - JOUR AB - Thermoplastic composites (TPCs) are predestined for use in lightweight structures, especially for high-volume applications. In many cases, joining is a key factor for the successful application of TPCs in multi-material systems. Many joining processes for this material group are based on warm forming the joining zone. This results in a change of the local material structure characterised by modified fibre paths, as well as varying fibre contents, which significantly influences the load-bearing behaviour. During the forming process, many different phenomena occur simultaneously at different scales. In this paper, the deformation modes and flow mechanisms of TPCs during forming described in the literature are first analysed. Based on this, three different joining processes are investigated: embedding of inserts, moulding of contour joints, and hotclinching. In order to identify the phenomena occurring in each process and to describe the characteristic resulting material structure in the joining zones, micrographs as well as computed tomography (CT) analyses are performed for both individual process stages and final joining zones. AU - Troschitz, Juliane AU - Gröger, Benjamin AU - Würfel, Veit AU - Kupfer, Robert AU - Gude, Maik ID - 34225 IS - 15 JF - Materials SN - 1996-1944 TI - Joining Processes for Fibre-Reinforced Thermoplastics: Phenomena and Characterisation VL - 15 ER - TY - JOUR AB - Unter dem Begriff der Auflösung wird für gewöhnlich das kleinste messbare Merkmal eines Messsystems verstanden. In der dimensionellen Computertomografie hingegen haben sich in den vergangenen Jahren mehrere Auflösungskonzepte etabliert, die aufgrund der fehlenden Normung zueinander im Kontrast stehen. In diesem Beitrag werden die drei häufigsten Konzepte, die Voxelgröße, die Ortsauflösung und die metrologische Strukturauflösung in Kürze vorgestellt. Anschließend wird eine Abgrenzung zwischen den Konzepten getroffen und ein Integration der bestehenden Konzepte in ein gemeinsames Amplituden-Wellenlängen Diagramm diskutiert. AU - Binder, Felix AU - Hausotte, Tino ID - 34221 IS - s1 JF - tm - Technisches Messen KW - Electrical and Electronic Engineering KW - Instrumentation SN - 2196-7113 TI - Über die Abgrenzung von Auflösungskonzepten in der industriellen Computertomografie VL - 89 ER - TY - JOUR AB - Die Erkennbarkeit von Rissen und geometrischen Qualitätskennwerten von Fügeverbindungen mittels Computertomografie ist von der Interfacestrukturauflösung abhängig, welche mittels geeigneter Prüfkörper untersucht wird. Die Reduktion von Abbildungsartefakten im Bereich von Bauteilzwischenräumen und -oberflächen verbessert deren dimensionelle Erfassbarkeit. AU - Busch, Matthias AU - Butzhammer, Lorenz AU - Hausotte, Tino ID - 34220 IS - s1 JF - tm - Technisches Messen KW - Electrical and Electronic Engineering KW - Instrumentation SN - 2196-7113 TI - Herausforderungen bei computertomografischen Untersuchungen von Fügeverbindungen VL - 89 ER - TY - CONF AU - Marx, Julian AU - Rieskamp, Jonas AU - Mirbabaie, Milad ID - 33519 T2 - Proceedings of the 33rd Australasian Conference on Information Systems TI - ‘Just a Normal Day in the Metaverse’ – Distraction Conflicts of Knowledge Work in Virtual Environments ER - TY - CONF AU - Alshomary, Milad AU - Rieskamp, Jonas AU - Wachsmuth, Henning ID - 32247 T2 - Proceedings of the 9th International Conference on Computational Models of Argument TI - Generating Contrastive Snippets for Argument Search ER - TY - THES AB - Das Ultraschall-Dickdrahtbonden mit Aluminiumdraht ist ein Standardverfahren zur elektrischenKontaktierung von Leistungshalbleitermodulen. Die steigenden Anforderungen an die Effizienzund Zuverlässigkeit der Module haben zu technologischen Weiterentwicklungen geführt und eswerden vermehrt Kupferdrähte mit wesentlich besseren elektrischen und thermischen Eigenschafteneingesetzt. Hieraus resultieren durch höhere Prozesskräfte und Ultraschallleistung neueHerausforderungen bei der Prozessentwicklung; hierfür wird ein Simulationsmodell zur Verbesserungder Prozessentwicklung entwickelt.In Ultraschall-Drahtbondversuchen mit 400 m Aluminium und Kupfer Drähten wurde der Einflussder Prozessparameter auf die Bondqualität untersucht; diese Ergebnisse und zusätzliche Messungender Drahtdeformation und Schwingungen wurden für die Formulierung der Anforderungenund zur Validierung der Ergebnisse des Simulationsmodells genutzt.Es wurde ein Prozessmodell, basierend auf einer Co-Simulation zwischen MATLAB und ANSYS,entwickelt; hierbei wurden die phyiskalischen Phänomene wie die Ultraschall Werkstoffentfestigung,der Verbindungsaufbau und die dynamischen Systemeigenschaften abgebildet.Basierend auf einer Zug-Druck-Prüfmaschine wurde ein Prüfstand zur Identifikation der Modellparameterentwickelt. In zusätzlichen Druckversuchen mit den Bonddrähten mit und ohneUltraschallanregung wurde die Reduktion der Umformkräfte unter Ultraschalleinfluss untersucht.Mit dem entwickelten Prozessmodell wurden die Parameterstudien aus den Ultraschall-Drahtbondversuchensimuliert und direkt mit den experimentellen Ergebnissen verglichen, wobei sich einerelativ gute Übereinstimmung zwischen Simulation und Messung sowohl für Aluminium, als auchfür Kupfer, erzielen ließ. AU - Schemmel, Reinhard ID - 34272 SN - 978-3-8440-8527-3 TI - Enhanced process development by simulation of ultrasonic heavy wire bonding VL - 13 ER - TY - JOUR AU - Gutt, Jana Kim AU - Thommes, Kirsten ID - 34283 IS - 1 JF - Academy of Management Proceedings KW - Microbiology SN - 0065-0668 TI - Speaking of Performance: Evaluating Team Members’ Performance with Open-Ended Audio Comments VL - 2022 ER - TY - CONF AU - Trentinaglia, Roman ID - 34298 T2 - Proceedings of the 25th International Conference on Model Driven Engineering Languages and Systems: Companion Proceedings TI - Deriving model-based safety and security assurance cases from design rationale of countermeasure patterns ER - TY - JOUR AB - Eines der Lernziele des Physikstudiums stellt der Erwerb literaler Fähigkeiten für das Verfassen wissenschaftlicher Arbeiten dar. Die Student:innen werden allerdings im Rahmen ihres Studiums bisher kaum systematisch beim Erwerb dieser Fähigkeiten unterstützt. Eine Übungsgelegenheit für das Verfassen von Texten nach wissenschaftlichem Vorbild stellt das Laborpraktikum dar, in dem die Student:innen zu den absolvierten Experimenten Laborberichte verfassen. Im Paderborner Physik Praktikum 3P wurden in den letzten Jahren vier unterschiedliche Unterstützungsangebote für das Erlernen des wissenschaftlichen Schreibens entwickelt und mittels Zufriedenheitswerten evaluiert. In dem Beitrag werden die vier Angebote auf inhaltlicher Ebene hinsichtlich der Lernwirksamkeit mittels einer schriftproduktbasierten Evaluation analysiert. Durch die vergleichende Analyse können Potenziale und Grenzen der Angebote diskutiert und Implikationen für die Gestaltung von Unterstützungsangeboten zum Erlernen des wissenschaftlichen Schreibens in der Physik abgeleitet werden. AU - Bauer, Anna Brigitte AU - Lahme, Simon Zacharias AU - Sacher, Marc ID - 34316 IS - 1 JF - PhyDid A - Physik und Didaktik in Schule und Hochschule KW - Laborpraktikum KW - Schreiben TI - Potenziale und Grenzen von Unterstützungsmaßnahmen zum wissenschaftlichen Schreiben im Paderborner Physik Praktikum 3P VL - 21 ER -