@article{30717, abstract = {{To achieve the climate objectives, various measures are taken to increase the efficiency of raw materials and energies used. A sector with a large proportion of the global consumption of resources is the mobility sector. To increase the efficiency in this field, large efforts are made to reduce the weight of moving masses. One approach is the use of multi-material systems, which utilises different materials and their specific properties depending on the local requirements. Multi-material systems consist often of materials which differ in strength and density, for example, high-strength steels, aluminium alloys or polymers. Additionally, such a system can utilise different geometries of the components to be joined, characterised for example by varying sheet thicknesses. A central challenge of producing these systems is the joining of the individual components. This requires robust joining processes capable of covering the entire spectrum of possible variants and is feasible for different physical properties of the materials. Since conventional joining processes are rather rigid and have difficulty reacting to changing process and disturbance variables, new joining processes are necessary. With the objective of being able to react versatile to varying parameters, a process combination consisting of a semi-tubular self-piercing riveting process and orbital forming process with adjustable tumbling kinematic is introduced. Due to the process combination of tumbling and self-piercing riveting, mutual influences of the two process components are analysed in regard to material flow and process forces. Further, the investigations show the influence of a varying tumbling angle on the joining process itself and how the characteristic properties undercut, rivet head end position and residual sheet thickness of the joint are affected. The material used for the joining partners is an aluminium alloy EN AW-6014 typical for multi-material systems in the automotive industry and the rivets are from type Rivset C produced by the Böllhoff company.}}, author = {{Wituschek, S. and Lechner, M.}}, journal = {{Production Engineering}}, title = {{{Investigation of the influence of the tumbling angle on a tumbling self-piercing riveting process}}}, doi = {{10.1177/14644207221080068}}, year = {{2022}}, } @article{30629, abstract = {{Clinching is a joining process that is becoming more and more important in industry due to the increasing use of multi-material designs. Despite the already widespread use of the process, there is still a need for research to understand the mechanisms and design of clinched joints. In contrast to the tool parameters, process and material disturbances have not yet been investigated to a relatively large extent. However, these also have a great influence on the properties and applicability of clinching. The effect of process disturbances on the clinched joint are investigated with numerical and experimental methods. The investigated process variations are the history of the sheets using the pre-hardening of the material, different sheet thicknesses, sheet arrangements and punch strokes. For the consideration of the material history, a specimen geometry for pre-stretching specimens in uniaxial tension is used, from which the pre-stretched secondary specimens are taken. A finite element model is set up for the numerical investigations. Suitable clinching tools are selected. With the simulation, selected process influences can be examined. The effort of the numerical investigations is considerably reduced with the help of a statistical experimental design according to Taguchi. To confirm the simulation results, experimental investigations of the clinch point geometry by using micrographs and the shear strength of the clinched joint are performed. The analysis of the influence of difference disturbance factors on the clinching process demonstrate the importance of the holistic view of the clinching process.}}, author = {{Steinfelder, C. and Acksteiner, J. and Guilleaume, C. and Brosius, A.}}, journal = {{Production Engineering}}, title = {{{Analysis of the interactions between joint and component properties during clinching}}}, doi = {{10.1007/s11740-021-01102-x}}, year = {{2022}}, } @article{30640, abstract = {{Surface determination is an essential step of the measurement process in industrial X-ray computed tomography (XCT). The starting point of the surface determination process step is a single grey value threshold within a voxel volume in conventional surface determination methods. However, this value is not always found in the reconstructed volume in the local environment of the surface of the measurement object due to various artefacts, so that none or incorrect surfaces are determined. In order to find surfaces independently of a single grey value, a three-dimensional approach of the initial contour determination based on a Prewitt edge detection algorithm is presented in this work. This method is applied to different test specimens and specimen compositions which, due to their material or material constellation, their geometric properties with regard to surfaces and interfaces as well as their calibrated size and length dimensions, embody relevant properties in the examination of joining connections. It is shown that by using the surface determination method in the measurement process, both a higher metrological structure resolution and interface structure resolution can be achieved. Surface artefacts can be reduced by the application and it is also an approach to improved surface finding for the multi-material components that are challenging for XCT.}}, author = {{Busch, M. and Hausotte, T.}}, journal = {{Production Engineering}}, title = {{{Application of an edge detection algorithm for surface determination in industrial X-ray computed tomography}}}, doi = {{10.1007/s11740-021-01100-z}}, year = {{2022}}, } @article{30628, abstract = {{The work carried out is based on the thesis properties of clinched joints are determined by the proportions of binding mechanisms form-closure, force-closure and material-closure. To describe the acting binding mechanisms and thus to derive the joint properties, detailed knowledge of the local effect of the individual binding mechanisms is necessary to ensure their targeted adjustment by the joining process. The targeted setting of different proportions of the binding mechanisms is achieved firstly via tool geometry and secondly via surface condition of the joined parts. An introduced form-closure component can be quantified by metallographic cross section with subsequent measurement of the quality-determining parameters such as undercut, penetration depth and neck thickness. To qualify the force-closure component, a torsional load can be applied mechanically at rotationally symmetrical clinch joints. This also allows the influence of different surface conditions on the tribological system to be quantified. Measurement of electrical resistance can reveal the binding mechanisms of force- and material-closure. These investigations are carried out on an aluminum joining part combination of the same type. As a result of these investigations, the clinched joints can be designed according to the load occurring in the later life cycle in the form of an optimum and compromise variant with regard to minimum loads to be transmitted mechanically, electrically with regard to low resistance or manufacturing with minimum energy input.}}, author = {{Kalich, J. and Füssel, U.}}, journal = {{Production Engineering}}, title = {{{Design of clinched joints on the basis of binding mechanisms}}}, doi = {{10.1007/s11740-022-01108-z}}, year = {{2022}}, } @article{30627, abstract = {{Additive plasticity in the logarithmic strain space is compared to multiplicative plasticity for various loading cases including coaxial and non-coaxial plastic deformations. Even though both finite plasticity approaches are based on total Lagrangian descriptions, the former is popular due to its inherent similarity to the infinitesimal theory and its easy extensibility. However, since its introduction several limitations of additive plasticity in the logarithmic strain space have been discovered. In this study, these problems such as stress rotation and softening are considered, revealing that fundamental differences compared to multiplicative plasticity occur for non-coaxial plastic deformations. We focus in particular on the observed softer response of the additive based approach, which is analysed in depth using three numerical examples including two well-known benchmarks for finite plasticity. By means of these finite element simulations the softer and possibly even localising response of additive plasticity in the logarithmic strain space is confirmed.}}, author = {{Friedlein, J. and Mergheim, J. and Steinmann, P.}}, journal = {{International Journal of Solids and Structures}}, pages = {{111416}}, title = {{{Observations on additive plasticity in the logarithmic strain space at excessive strains}}}, doi = {{10.1016/j.ijsolstr.2021.111416}}, volume = {{239-240}}, year = {{2022}}, } @article{29182, author = {{Chang, M. and Büchel, Daniel and Reinecke, K. and Lehmann, T. and Baumeister, Jochen}}, issn = {{0953-816X}}, journal = {{European Journal of Neuroscience}}, keywords = {{General Neuroscience}}, publisher = {{Wiley}}, title = {{{Ecological Validity in Exercise Neuroscience Research: A Systematic Investigation}}}, doi = {{10.1111/ejn.15595}}, year = {{2022}}, } @inproceedings{29220, abstract = {{Modern services often comprise several components, such as chained virtual network functions, microservices, or machine learning functions. Providing such services requires to decide how often to instantiate each component, where to place these instances in the network, how to chain them and route traffic through them. To overcome limitations of conventional, hardwired heuristics, deep reinforcement learning (DRL) approaches for self-learning network and service management have emerged recently. These model-free DRL approaches are more flexible but typically learn tabula rasa, i.e., disregard existing understanding of networks, services, and their coordination. Instead, we propose FutureCoord, a novel model-based AI approach that leverages existing understanding of networks and services for more efficient and effective coordination without time-intensive training. FutureCoord combines Monte Carlo Tree Search with a stochastic traffic model. This allows FutureCoord to estimate the impact of future incoming traffic and effectively optimize long-term effects, taking fluctuating demand and Quality of Service (QoS) requirements into account. Our extensive evaluation based on real-world network topologies, services, and traffic traces indicates that FutureCoord clearly outperforms state-of-the-art model-free and model-based approaches with up to 51% higher flow success ratios.}}, author = {{Werner, Stefan and Schneider, Stefan Balthasar and Karl, Holger}}, booktitle = {{IEEE/IFIP Network Operations and Management Symposium (NOMS)}}, keywords = {{network management, service management, AI, Monte Carlo Tree Search, model-based, QoS}}, location = {{Budapest}}, publisher = {{IEEE}}, title = {{{Use What You Know: Network and Service Coordination Beyond Certainty}}}, year = {{2022}}, } @article{29296, author = {{Schmolke, Tobias and Krüger, Christopher and Merdivan, David and Meschut, Gerson}}, journal = {{ATZ worldwide}}, number = {{1}}, pages = {{66--71}}, title = {{{Weight-optimized Battery Housings for Volume Vehicles}}}, doi = {{https://doi.org/10.1007/s38311-021-0766-7}}, volume = {{124}}, year = {{2022}}, } @inproceedings{29342, author = {{Sander, Sascha and Teutenberg, Dominik and Meschut, Gerson and Kötz, Fabian and Matzenmiller, Anton and Kasper, Yann and Ummenhofer, Thomas}}, booktitle = {{22. Kolloquium Gemeinsame Forschung in der Klebtechnik}}, location = {{Online Konferenz}}, title = {{{Methodenentwicklung zur rechnerischen Auslegung geklebter Stahlverbindungen unter Alterungsbeanspruchung im Stahl- und Anlagenbau }}}, year = {{2022}}, } @article{21571, abstract = {{The paper investigates the impact of individual attention on investor risk-taking. We analyze a large sample of trading records from a brokerage service that allows its customers to trade contracts-for-differences (CFD), and sends standardized push messages on recent stock performance to its client investors. The advantage of this sample is that it allows us to isolate the "push" messages as individual attention triggers, which we can directly link to the same individuals' risk-taking. A particular advantage of CFD trading is that it allows investors to make use of leverage, which provides us a pure measure of investors' willingness to take risks that is independent of the decision to purchase a particular stock. Leverage is a major catalyst of speculative trading, as it increases the scope of extreme returns, and enables investors to take larger positions than what they can afford with their own capital. We show that investors execute attention-driven trades with higher leverage, compared to their other trades, as well as those of other investors who are not alerted by attention triggers.}}, author = {{Arnold, Marc and Pelster, Matthias and Subrahmanyam, Marti G.}}, journal = {{Journal of Financial Economics}}, number = {{2}}, pages = {{ 846--875}}, title = {{{Attention triggers and investors' risk-taking}}}, doi = {{10.1016/j.jfineco.2021.05.031}}, volume = {{143}}, year = {{2022}}, } @inproceedings{29302, abstract = {{This paper introduces the project Scale4Edge. The project is focused on enabling an effective RISC-V ecosystem for optimization of edge applications. We describe the basic components of this ecosystem and introduce the envisioned demonstrators, which will be used in their evaluation.}}, author = {{Ecker, Wolfgang and Adelt, Peer and Müller, Wolfgang and Heckmann, Reinhold and Krstic, Milos and Herdt, Vladimir and Drechsler, Rolf and Angst, Gerhard and Wimmer, Ralf and Mauderer, Andreas and Stahl, Rafael and Emrich, Karsten and Mueller-Gritschneder, Daniel and Becker, Bernd and Scholl, Philipp and Jentzsch, Eyck and Schlamelcher, Jan and Grüttner, Kim and Bernardo, Paul Palomero and Brinkmann, Oliver and Damian, Mihaela and Oppermann, Julian and Koch, Andreas and Bormann, Jörg and Partzsch, Johannes and Mayr, Christian and Kunz, Wolfgang}}, booktitle = {{In Proceedings of the Design Automation and Test Conference and Exhibition (DATE 2022)}}, title = {{{The Scale4Edge RISC-V Ecosystem}}}, year = {{2022}}, } @article{29295, author = {{Schmolke, Tobias and Krüger, Christopher and Merdivan, David and Meschut, Gerson}}, journal = {{ ATZ - Automobiltechnische Zeitschrift}}, number = {{1}}, pages = {{80--85}}, title = {{{Gewichtsoptimierte Batteriegehäuse für Volumenfahrzeuge}}}, doi = {{https://doi.org/10.1007/s35148-021-0785-0}}, volume = {{124}}, year = {{2022}}, } @inbook{29355, author = {{Mildorf, Jarmila}}, booktitle = {{Erzählte Welt: Sinnstiftung in Zeiten kultureller und politischer Umbrüche}}, editor = {{Schachtner, Christina and Drews, Albert}}, pages = {{167--194}}, publisher = {{Evangelische Akademie Loccum}}, title = {{{Durch Andere sich selbst erzählen: Figuren der Selbststilisierung in autobiographischen Schriften von Alan Bennett und Candia McWilliam}}}, volume = {{9}}, year = {{2022}}, } @article{23415, author = {{Sperling, Martina and Schryen, Guido}}, journal = {{European Journal of Operational Research (EJOR)}}, number = {{2}}, pages = {{690 -- 705}}, title = {{{Decision Support for Disaster Relief: Coordinating Spontaneous Volunteers}}}, volume = {{299}}, year = {{2022}}, } @article{27776, author = {{Koldewey, Christian and Rasor, Anja and Reinhold, Jannik and Gausemeier, Jürgen and Dumitrescu, Roman and Chohan, Nadia and Frank, Maximilian}}, issn = {{0040-1625}}, journal = {{Technological Forecasting and Social Change}}, publisher = {{Elsevier}}, title = {{{Aligning strategic position, behavior, and structure for smart service businesses in manufacturing}}}, doi = {{10.1016/j.techfore.2021.121329}}, year = {{2022}}, } @inproceedings{29539, abstract = {{Explainable Artificial Intelligence (XAI) is currently an important topic for the application of Machine Learning (ML) in high-stakes decision scenarios. Related research focuses on evaluating ML algorithms in terms of interpretability. However, providing a human understandable explanation of an intelligent system does not only relate to the used ML algorithm. The data and features used also have a considerable impact on interpretability. In this paper, we develop a taxonomy for describing XAI systems based on aspects about the algorithm and data. The proposed taxonomy gives researchers and practitioners opportunities to describe and evaluate current XAI systems with respect to interpretability and guides the future development of this class of systems.}}, author = {{Kucklick, Jan-Peter}}, booktitle = {{Wirtschaftsinformatik 2022 Proceedings}}, keywords = {{Explainable Artificial Intelligence, XAI, Interpretability, Decision Support Systems, Taxonomy}}, location = {{Nürnberg (online)}}, title = {{{Towards a model- and data-focused taxonomy of XAI systems}}}, year = {{2022}}, } @unpublished{29541, author = {{Lienen, Christian and Platzner, Marco}}, title = {{{ReconROS Executor: Event-Driven Programming of FPGA-accelerated ROS 2 Applications}}}, year = {{2022}}, } @inbook{29104, abstract = {{The digitalization of workplaces can introduce changes on various levels of work activities. Educational research follows this transformation in one of two ways: On the one hand, there is the optimistic perspective of expecting to improve the quality of work and work life; on the other hand, there is the expectation that conditions of work and work life will generally deteriorate. Irrespective of the concrete outcomes of digitalization, a general agreement exists that digitalization will induce changes at workplaces that affect individuals and the tasks they do. At the same time, however, scholars disagree as to whether employees experience these changes in terms of affordances that engage them into learning new processes or if they experience constraints that inhibit further engagement in learning. This chapter explores the particular developments covered under the topic of digitalization at and of work, explains particular challenges of the introduction of cyber-physical systems and analyzes consequences for workplace learning. It focuses on conceptual change as a theoretical framework for understanding the quality of learning processes that seem inevitable in order to cope with the new requirements and – more importantly – to use the potentials of the new technologies. It then sketches the poor state of empirical research conducted in this area – so far limited to exploratory field studies – even in times of corona, which has boosted the digital transformation. The chapter ends with a description of the potential and problems of – at best interdisciplinary – research into learning at digitalized workplaces.}}, author = {{Harteis, Christian and Goller, Michael and Gerholz, Karl-Heinz}}, booktitle = {{The SAGE Handbook of Learning and Work}}, editor = {{Malloch, Margaret and Cairns, Len and Evans, Karen and O'Connor, Bridget N.}}, isbn = {{978-1-5264-9111-4}}, pages = {{329--342}}, publisher = {{SAGE Publications}}, title = {{{Digitalization of work: Challenges for workplace learning}}}, year = {{2022}}, } @article{29103, abstract = {{Im Praxissemester (PS) sind Mentor*innen für Studierende wichtige Bezugspersonen, die sie u. a. bei der Planung, Durchführung und Reflexion von Unterricht begleiten. Während z.B. zur Kompetenzentwicklung Studierender im PS mehrere Erkenntnisse vorliegen, ist die Perspektive von Mentor*innen bisher wenig untersucht. Dieser Bericht zielt darauf, die Relevanz von Mentor*innen herauszuarbeiten, Forschungsdesiderate zu umreißen und Handlungsoptionen aufzuzeigen.}}, author = {{Caruso, Carina and Goller, Michael}}, journal = {{Die Deutsche Schule}}, keywords = {{Schlagwörter: Mentoring, Praxissemester, Professionalisierung}}, number = {{4}}, publisher = {{Waxmann}}, title = {{{Die Relevanz von Mentor*innen für die Professionalisierung von angehenden Lehrkräften im Praxissemester: Forschungsdesiderate und Handlungsoptionen}}}, volume = {{114}}, year = {{2022}}, } @phdthesis{29763, abstract = {{Modern-day communication has become more and more digital. While this comes with many advantages such as a more efficient economy, it has also created more and more opportunities for various adversaries to manipulate communication or eavesdrop on it. The Snowden revelations in 2013 further highlighted the seriousness of these threats. To protect the communication of people, companies, and states from such threats, we require cryptography with strong security guarantees. Different applications may require different security properties from cryptographic schemes. For most applications, however, so-called adaptive security is considered a reasonable minimal requirement of security. Cryptographic schemes with adaptive security remain secure in the presence of an adversary that can corrupt communication partners to respond to messages of the adversaries choice, while the adversary may choose the messages based on previously observed interactions. While cryptography is associated the most with encryption, this is only one of many primitives that are essential for the security of digital interactions. This thesis presents novel identity-based encryption (IBE) schemes and verifiable random functions (VRFs) that achieve adaptive security as outlined above. Moreover, the cryptographic schemes presented in this thesis are proven secure in the standard model. That is without making use of idealized models like the random oracle model.}}, author = {{Niehues, David}}, keywords = {{public-key cryptography, lattices, pairings, verifiable random functions, identity-based encryption}}, title = {{{More Efficient Techniques for Adaptively-Secure Cryptography}}}, doi = {{10.25926/rdtq-jw45}}, year = {{2022}}, }