@article{61255, abstract = {{Abstract Topological states have been widely investigated in different types of systems and lattices. In the present work, we report on topological edge states in double-wave (DW) chains, which can be described by a generalized Aubry-André-Harper (AAH) model. For the specific system of a driven-dissipative exciton polariton system we show that in such potential chains, different types of edge states can form. For resonant optical excitation, we further find that the optical nonlinearity leads to a multistability of different edge states. This includes topologically protected edge states evolved directly from individual linear eigenstates as well as additional edge states that originate from nonlinearity-induced localization of bulk states. Extending the system into two dimensions (2D) by stacking horizontal DW chains in the vertical direction, we also create 2D multi-wave lattices. In such 2D lattices multiple Su–Schrieffer–Heeger (SSH) chains appear along the vertical direction. The combination of DW chains in the horizonal and SSH chains in the vertical direction then results in the formation of higher-order topological insulator corner states. Multistable corner states emerge in the nonlinear regime.}}, author = {{Schneider, Tobias and Gao, Wenlong and Zentgraf, Thomas and Schumacher, Stefan and Ma, Xuekai}}, issn = {{2192-8614}}, journal = {{Nanophotonics}}, number = {{4}}, pages = {{509--518}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates}}}, doi = {{10.1515/nanoph-2023-0556}}, volume = {{13}}, year = {{2024}}, } @article{61257, abstract = {{Exceptional points (EPs), with their intriguing spectral topology, have attracted considerable attention in a broad range of physical systems, with potential sensing applications driving much of the present research in this field. Here, we investigate spectral topology and EPs in systems with significant nonlinearity, exemplified by a nonequilibrium exciton-polariton condensate. With the possibility to control loss and gain and nonlinearity by optical means, this system allows for a comprehensive analysis of the interplay of nonlinearities (Kerr type and saturable gain) and non-Hermiticity. Not only do we find that EPs can be intentionally shifted in parameter space by the saturable gain, but we also observe intriguing rotations and intersections of Riemann surfaces and find nonlinearity-enhanced sensing capabilities. With this, our results illustrate the potential of tailoring spectral topology and related phenomena in non-Hermitian systems by nonlinearity. Published by the American Physical Society 2024 }}, author = {{Wingenbach, Jan and Schumacher, Stefan and Ma, Xuekai}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, number = {{1}}, publisher = {{American Physical Society (APS)}}, title = {{{Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems}}}, doi = {{10.1103/physrevresearch.6.013148}}, volume = {{6}}, year = {{2024}}, } @article{61258, abstract = {{AbstractThermal stability is crucial for doped organic semiconductors (OSCs) and their applications in organic thermoelectric (OTE) devices. However, the capacity of n‐dopants to produce thermally stable n‐doped OSC films has not been thoroughly explored, with few reports of high thermal stability. Here, a novel n‐dopant, phosphazenium tetrafluoroborate (P2BF4) is introduced, which effectively induces n‐doping in N2200, P(PzDPP‐CT2) and several other commonly used OSCs. Remarkably, the electrical conductivity of P2BF4‐doped OSC films remains almost unchanged even after heating at temperatures > 150 °C for 24 h, far superior to the films doped with benchmark N‐DMBI. The exceptional thermal stability observed in P2BF4‐doped P(PzDPP‐CT2) films allows for stable operation of the corresponding organic thermoelectric devices at 150 °C for 16 h, a milestone not previously achieved. This study offers valuable insights into the development of n‐dopants capable of producing OSCs with outstanding thermal stability, paving the way for the practical realization of OTE devices with enhanced operation stability.}}, author = {{Wei, Huan and Guo, Jing and Liu, Heng and Wu, Tong and Chen, Ping‐An and Dong, Chuanding and Wang, Shu‐Jen and Schumacher, Stefan and Bai, Yugang and Lei, Ting and Wang, Suhao and Hu, Yuanyuan}}, issn = {{2199-160X}}, journal = {{Advanced Electronic Materials}}, publisher = {{Wiley}}, title = {{{Novel Phosphazenium Tetrafluoroborate Dopant Enables Efficient and Thermally Stable n‐Doped Organic Semiconductors}}}, doi = {{10.1002/aelm.202400767}}, year = {{2024}}, } @article{61259, author = {{Bauch, Fabian and Dong, Chuan-Ding and Schumacher, Stefan}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, number = {{8}}, pages = {{3525--3532}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Dynamics of Electron–Hole Coulomb Attractive Energy and Dipole Moment of Hot Excitons in Donor–Acceptor Polymers}}}, doi = {{10.1021/acs.jpcc.3c07513}}, volume = {{128}}, year = {{2024}}, } @article{61263, abstract = {{Charge transfer mechanism in the deprotonation-induced n-type doping of PCBM.}}, author = {{Dong, Chuan-Ding and Bauch, Fabian and Hu, Yuanyuan and Schumacher, Stefan}}, issn = {{1463-9076}}, journal = {{Physical Chemistry Chemical Physics}}, number = {{5}}, pages = {{4194--4199}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Charge transfer in superbase n-type doping of PCBM induced by deprotonation}}}, doi = {{10.1039/d3cp05105f}}, volume = {{26}}, year = {{2024}}, } @article{61261, author = {{Liang, Qian and Ma, Xuekai and Gu, Chunling and Ren, Jiahuan and An, Cunbin and Fu, Hongbing and Schumacher, Stefan and Liao, Qing}}, issn = {{0002-7863}}, journal = {{Journal of the American Chemical Society}}, number = {{7}}, pages = {{4542--4548}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Photochemical Reaction Enabling the Engineering of Photonic Spin–Orbit Coupling in Organic-Crystal Optical Microcavities}}}, doi = {{10.1021/jacs.3c11373}}, volume = {{146}}, year = {{2024}}, } @article{57461, abstract = {{This study empirically examines the "Evaluative AI" framework, which aims to enhance the decision-making process for AI users by transitioning from a recommendation-based approach to a hypothesis-driven one. Rather than offering direct recommendations, this framework presents users pro and con evidence for hypotheses to support more informed decisions. However, findings from the current behavioral experiment reveal no significant improvement in decision-making performance and limited user engagement with the evidence provided, resulting in cognitive processes similar to those observed in traditional AI systems. Despite these results, the framework still holds promise for further exploration in future research. }}, author = {{Kornowicz, Jaroslaw}}, journal = {{arXiv}}, title = {{{An Empirical Examination of the Evaluative AI Framework}}}, doi = {{10.48550/ARXIV.2411.08583}}, year = {{2024}}, } @inproceedings{61273, abstract = {{In human-machine explanation interactions, such as tutoring systems or customer support chatbots, it is important for the machine explainer to infer the human user's understanding. Nonverbal signals play an important role for expressing mental states like understanding and confusion in these interactions. However, an individual's expressions may vary depending on other factors. In cases where these factors are unknown, machine learning methods that infer understanding from nonverbal cues become unreliable. Stress for example has been shown to affect human expression, but it is not clear from the current research how stress affects the expression of understanding. To address this gap, we design a paradigm that induces understanding and confusion through game rule explanations. During the explanations, self-perceived understanding and confusion are annotated by the participants. A stress condition is also introduced to enable the investigation of changes in the expression of social signals under stress. We conducted a study to validate the stress induction and participants reported a statistically significant increase in stress during the stress condition compared to the neutral control condition. Additionally, feedback from participants shows that the paradigm is effective in inducing understanding and confusion. This paradigm paves the way for further studies investigating social signals of understanding to improve human-machine explanation interactions for varying contexts.}}, author = {{Paletschek, Jonas}}, booktitle = {{12th International Conference on Affective Computing & Intelligent Interaction}}, keywords = {{Understanding, Nonverbal Social Signals, Stress Induction, Explanation, Machine Learning Bias}}, location = {{Glasgow}}, publisher = {{IEEE}}, title = {{{A Paradigm to Investigate Social Signals of Understanding and Their Susceptibility to Stress}}}, doi = {{10.1109/ACII63134.2024.00040}}, year = {{2024}}, } @article{61290, abstract = {{ffective computing often relies on audiovisual data to identify affective states from non-verbal signals, such as facial expressions and vocal cues. Since automatic affect recognition can be used in sensitive applications, such as healthcare and education, it is crucial to understand how models arrive at their decisions. Interpretability of machine learning models is the goal of the emerging research area of Explainable AI (explainable AI (XAI)). This scoping review aims to survey the field of audiovisual affective machine learning to identify how XAI is applied in this domain. We first provide an overview of XAI concepts relevant to affective computing. Next, following the recommended PRISMA guidelines, we perform a literature search in the ACM, IEEE, Web of Science and PubMed databases. After systematically reviewing 1190 articles, a final set of 65 papers is included in our analysis. We quantitatively summarize the scope, methods and evaluation of the XAI techniques used in the identified papers. Our findings show encouraging developments for using XAI to explain models in audiovisual affective computing, yet only a limited set of methods are used in the reviewed works. Following a critical discussion, we provide recommendations for incorporating interpretability in future work for affective machine learnin}}, author = {{Johnson, David and Hakobyan, Olya and Paletschek, Jonas and Drimalla, Hanna}}, issn = {{1949-3045}}, journal = {{IEEE Transactions on Affective Computing}}, number = {{2}}, pages = {{518--536}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Explainable AI for Audio and Visual Affective Computing: A Scoping Review}}}, doi = {{10.1109/taffc.2024.3505269}}, volume = {{16}}, year = {{2024}}, } @article{55394, abstract = {{Nowadays we deal with robots and AI more and more in our everyday life. However, their behavior is not always apparent to most lay users, especially in error situations. This can lead to misconceptions about the behavior of the technologies being used. This in turn can lead to misuse and rejection by users. Explanation, for example through transparency, can address these misconceptions. However, explaining the entire software or hardware would be confusing and overwhelming for users. Therefore, this paper focuses on the ‘enabling’ architecture. It describes those aspects of a robotic system that may need to be explained to enable someone to use the technology effectively. Furthermore, this paper deals with the ‘explanandum’, i.e. the corresponding misunderstandings or missing concepts of the enabling architecture that need to be clarified. Thus, we have developed and are presenting an approach to determine the ‘enabling’ architecture and the resulting ‘explanandum’ of complex technologies.}}, author = {{Beierling, Helen and Richter, Phillip and Brandt, Mara and Terfloth, Lutz and Schulte, Carsten and Wersing, Heiko and Vollmer, Anna-Lisa}}, journal = {{Cognitive Systems Research}}, keywords = {{Robotics HRI Explainability Didactics Didactic reconstruction}}, publisher = {{Elsevier}}, title = {{{What you need to know about a learning robot: Identifying the enabling architecture of complex systems}}}, volume = {{88}}, year = {{2024}}, } @misc{55398, abstract = {{This position paper calls for an increase in the number and flexibility of input mechanisms in user-robot in- teractions, highlighting their potential to enhance learning algo- rithms through user feedback. Moreover, we argue that refining interfaces, interactions, and systems is crucial for the optimal integration of mechanisms into learning processes. Our call to research involves the development of interfaces that enable flexible mechanisms, and the mechanisms interactions can benefit most from, and the algorithmic incorporation of user input. This aims to advance the adaptability and responsiveness of robotic systems in human-centric environments}}, author = {{Beierling, Helen and Loos, Kira and Helmert, Robin and Vollmer, Anna-Lisa}}, publisher = {{Proc. Mech. Mapping Hum. Input Robots Robot Learn. Shared Control/Autonomy-Workshop RSS}}, title = {{{Advancing Human-Robot Collaboration: The Impact of Flexible Input Mechanisms}}}, year = {{2024}}, } @inproceedings{61350, author = {{Massopo, Orlando and Schmid, Hans-Joachim and Reddemann, Manuel and Kneer, Reinhold and Bieber, Malte}}, publisher = {{6th International Symposium Gas-Phase Synthesis of Functional Nanomaterials: Fundamental Understanding, Modeling and Simulation, Scale-up and Application}}, title = {{{Influence of Dispersion Gas and Resulting Reaction Zone on the Particle Formation in Spray Flame Synthesis (Presentation)}}}, year = {{2024}}, } @misc{61345, author = {{Zink, Timm Florian and Massopo, Orlando and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, title = {{{Untersuchung des Lösungsmitteleinflusses auf die Synthese von Manganoxid-Nanopartikeln in der Flammenspraypyrolyse}}}, year = {{2024}}, } @misc{61347, author = {{El Gabbouhi, Abderazzak and Massopo, Orlando and Jesinghausen, Steffen and Schmid, Hans-Joachim}}, title = {{{Einfluss der Zerstäubungsparameter auf die Partikelbildung und die Eigenschaften der Endproduktpulver (Studienarbeit)}}}, year = {{2024}}, } @article{61357, author = {{Krenz, Marvin and Sanna, Simone and Gerstmann, Uwe and Schmidt, Wolf Gero}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, number = {{41}}, pages = {{17774--17778}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Understanding and Improving Triplet Exciton Transfer in Sensitized Silicon Solar Cells}}}, doi = {{10.1021/acs.jpcc.4c05446}}, volume = {{128}}, year = {{2024}}, } @article{57914, author = {{Ballweg, Sandra}}, journal = {{Zeitschrift für Interaktionsforschung in DaFZ}}, number = {{1}}, pages = {{29--53}}, title = {{{ "Was heißt das, Mama?" Die Familie als Ort von Sprachaneignung und mehrsprachigen Praktiken am Beispiel einer türkisch-deutsch-sprachigen Familie}}}, doi = {{10.17192/ZIAF.2024.4.1.8672}}, volume = {{4}}, year = {{2024}}, } @book{60231, author = {{Reijers, Wessel and de Filippi, Primavera and Mannan, Morshed }}, title = {{{Blockchain Governance}}}, year = {{2024}}, } @inproceedings{61403, author = {{Lohmer, Vivien and Kern, Friederike}}, booktitle = {{Second International Multimodal Communication Symposium (MMSYM) - Book of Abstract}}, keywords = {{gesture, explanations, conversation analysis}}, location = {{Goethe-Universität Frankfurt, Deutschland}}, title = {{{The role of interactive gestures in explanatory interactions}}}, year = {{2024}}, } @article{61413, abstract = {{Climate change has led to a large number of countries deciding to reduce carbon dioxide (CO2) emissions significantly. As the mobility sector is a major contributor to CO2, various strategies are being pursued to achieve the climate targets set. An increasingly applied lightweight design method is the use of multi-material constructions. To join these structures, mechanical joining technologies such as self-pierce riveting are being used. As a result of the currently rigid tool systems, which cannot react to changing boundary conditions, a large number of rivet–die combinations is required to join the rising number of materials as well as material thickness combinations. Thus, new, versatile joining technologies are needed that can react to the described changes. The versatile self-piercing riveting (V-SPR) process is one possible approach. In this process, different material thicknesses can be joined by using a multi-range capable rivet which is set by a joining system with extended actuator technology. In this study, the V-SPR joining process is analysed numerically according to the influence of the geometrical rivet parameters on the joints characteristics as well as the resulting material flow. The investigations showed that the shank geometry has a decisive influence on the expansion of the rivet. Furthermore, the rivet length could be proven to be an influencing factor. By changing the head radii and the protrusion height, the forming behaviour of the rivet head onto the punch-sided joining part could be improved and thus the formation of air pockets was prevented. Based on the numerical investigations, a novel rivet geometry was developed and produced by machining. Subsequently, experimentally produced joints were analysed according to their joint formation and load-bearing capacity.}}, author = {{Kappe, Fabian and Bobbert, Mathias and Meschut, Gerson}}, issn = {{0954-4089}}, journal = {{Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering}}, publisher = {{SAGE Publications}}, title = {{{Investigation of the influence of the rivet geometry on joint formation for a versatile self-piercing riveting process}}}, doi = {{10.1177/09544089241263141}}, year = {{2024}}, } @article{61414, abstract = {{The increasing significance of ecological responsibility, stricter political regulations and economic objectives are driving innovation in research fields such as lightweight construction. One of the most important popular methods is the use of multi-material systems. Due to the different geometric and mechanical properties of the various materials used, resource efficient applications and utilizations are possible. Great challenges arise for the joining processes to realize these multi-material systems, since conventional joining processes reach their limits. In the field of mechanical joining processes, there are continuously new approaches, such as superimposing the punch in a self-piercing riveting process with a tumbling kinematic, to increase the number of adaptable process parameters and enhance the process control. Through various preliminary tests, a good understanding of the process has been developed, which allows to directly control the geometric joint parameters by configuring the tumbling strategy. A major challenge, particularly with regard to future industrial applications, is the process time, which is comparatively high due to the tumbling kinematics. In the investigations, a reduction of approximately 90% of the process time is targeted by adapting the joining and tumbling strategy. Therefore, the correlation of the traverse velocity and the tumbling velocity are examined in a gradual series of experiments. To represent realistic applications, the experiments are carried out with a dual-phase steel and a precipitation-hardening aluminum alloy. For identifying the influence of the process parameters on the joining process, a constant rivet–die combination is applied. Further, the examination of force–displacement curves is conducted. Moreover, the determination of geometric joint parameters is reliant upon macrographs to assess the influence of the joining time on the geometric joint formation. The test results show that a significant increase in joining speed with a resulting reduction in process time is feasible. Although the joining properties are affected, reliable joining is possible. In particular, the shaft thickness of the rivet is influenced by the varying proportion of the tumbling process in the joining operation and increases with higher joining speeds.}}, author = {{Wituschek, Simon and Elbel, Leonie and Lechner, Michael}}, issn = {{0954-4089}}, journal = {{Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering}}, publisher = {{SAGE Publications}}, title = {{{Influence of the process time on a self-piercing riveting process with tumbling kinematic}}}, doi = {{10.1177/09544089241248430}}, year = {{2024}}, }