TY - GEN AU - Mapura Ramirez, Luz Alejandra AU - Kenig, Eugeny Y. ID - 46591 TI - Zur Berechnug von flüssigkeitsseitigen Stoffübergagnskoeffizienten für Strukturpackungen ER - TY - JOUR AB - The Koopman operator has become an essential tool for data-driven approximation of dynamical (control) systems in recent years, e.g., via extended dynamic mode decomposition. Despite its popularity, convergence results and, in particular, error bounds are still quite scarce. In this paper, we derive probabilistic bounds for the approximation error and the prediction error depending on the number of training data points; for both ordinary and stochastic differential equations. Moreover, we extend our analysis to nonlinear control-affine systems using either ergodic trajectories or i.i.d. samples. Here, we exploit the linearity of the Koopman generator to obtain a bilinear system and, thus, circumvent the curse of dimensionality since we do not autonomize the system by augmenting the state by the control inputs. To the best of our knowledge, this is the first finite-data error analysis in the stochastic and/or control setting. Finally, we demonstrate the effectiveness of the proposed approach by comparing it with state-of-the-art techniques showing its superiority whenever state and control are coupled. AU - Nüske, Feliks AU - Peitz, Sebastian AU - Philipp, Friedrich AU - Schaller, Manuel AU - Worthmann, Karl ID - 23428 JF - Journal of Nonlinear Science TI - Finite-data error bounds for Koopman-based prediction and control VL - 33 ER - TY - GEN AB - Different conflicting optimization criteria arise naturally in various Deep Learning scenarios. These can address different main tasks (i.e., in the setting of Multi-Task Learning), but also main and secondary tasks such as loss minimization versus sparsity. The usual approach is a simple weighting of the criteria, which formally only works in the convex setting. In this paper, we present a Multi-Objective Optimization algorithm using a modified Weighted Chebyshev scalarization for training Deep Neural Networks (DNNs) with respect to several tasks. By employing this scalarization technique, the algorithm can identify all optimal solutions of the original problem while reducing its complexity to a sequence of single-objective problems. The simplified problems are then solved using an Augmented Lagrangian method, enabling the use of popular optimization techniques such as Adam and Stochastic Gradient Descent, while efficaciously handling constraints. Our work aims to address the (economical and also ecological) sustainability issue of DNN models, with a particular focus on Deep Multi-Task models, which are typically designed with a very large number of weights to perform equally well on multiple tasks. Through experiments conducted on two Machine Learning datasets, we demonstrate the possibility of adaptively sparsifying the model during training without significantly impacting its performance, if we are willing to apply task-specific adaptations to the network weights. Code is available at https://github.com/salomonhotegni/MDMTN. AU - Hotegni, Sedjro Salomon AU - Peitz, Sebastian AU - Berkemeier, Manuel Bastian ID - 46649 T2 - arXiv:2308.12243 TI - Multi-Objective Optimization for Sparse Deep Neural Network Training ER - TY - JOUR AU - Gonchikzhapov, Munko AU - Kasper, Tina ID - 46637 JF - Applications in Energy and Combustion Science KW - Nanoparticle synthesis KW - Flame spray pyrolysis KW - SpraySyn burner KW - Flame structure KW - Species distribution KW - Temperature distribution SN - 2666-352X TI - Thermal and chemical structure of ethanol and 2-ethylhexanoic acid/ethanol SpraySyn flames VL - 15 ER - TY - JOUR AB - Many problems in science and engineering require an efficient numerical approximation of integrals or solutions to differential equations. For systems with rapidly changing dynamics, an equidistant discretization is often inadvisable as it results in prohibitively large errors or computational effort. To this end, adaptive schemes, such as solvers based on Runge–Kutta pairs, have been developed which adapt the step size based on local error estimations at each step. While the classical schemes apply very generally and are highly efficient on regular systems, they can behave suboptimally when an inefficient step rejection mechanism is triggered by structurally complex systems such as chaotic systems. To overcome these issues, we propose a method to tailor numerical schemes to the problem class at hand. This is achieved by combining simple, classical quadrature rules or ODE solvers with data-driven time-stepping controllers. Compared with learning solution operators to ODEs directly, it generalizes better to unseen initial data as our approach employs classical numerical schemes as base methods. At the same time it can make use of identified structures of a problem class and, therefore, outperforms state-of-the-art adaptive schemes. Several examples demonstrate superior efficiency. Source code is available at https://github.com/lueckem/quadrature-ML. AU - Dellnitz, Michael AU - Hüllermeier, Eyke AU - Lücke, Marvin AU - Ober-Blöbaum, Sina AU - Offen, Christian AU - Peitz, Sebastian AU - Pfannschmidt, Karlson ID - 21600 IS - 2 JF - SIAM Journal on Scientific Computing TI - Efficient time stepping for numerical integration using reinforcement learning VL - 45 ER - TY - CHAP AU - Dahms, Frederik AU - Homberg, Werner ID - 46691 SN - 2195-4356 T2 - Lecture Notes in Mechanical Engineering TI - Analysis and Modelling of the Deformation in the Manufacture of Flange-Contours by the Combined Friction-Spinning and Flow-Forming Process ER - TY - CONF AU - Garnefeld, I. AU - Böhm, Eva AU - Hanf, L. AU - Helm, S. ID - 46665 T2 - 2023 AMA Summer Academic Conference, San Francisco, CA TI - Unboxing video effectiveness – Does speech matter? ER - TY - CONF AU - Kessing, K. AU - Garnefeld, I. AU - Böhm, Eva ID - 46666 T2 - EMAC Annual Conference, Odense, Denmark TI - The dark and bright side of online reviews in manufacturer online shops ER - TY - CONF AU - Hanf, L. AU - Garnefeld, I. AU - Böhm, Eva AU - Helm, S. ID - 46667 T2 - EMAC Annual Conference, Odense, Denmark TI - Stimulating engagement with unboxing videos – Does speech matter? ER - TY - CONF AU - Sadeghi-Kohan, Somayeh AU - Hellebrand, Sybille AU - Wunderlich, Hans-Joachim ID - 46739 T2 - 2023 53rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks Workshops (DSN-W) TI - Low Power Streaming of Sensor Data Using Gray Code-Based Approximate Communication ER - TY - CONF AU - Janzen, Thomas AU - Wotschel, Philipp AU - Meier, Jana AU - Vogelsang, Christoph ID - 46740 T2 - EARLI 2023 TI - Assessing pre-service EFL teachers’ feedback performance in role-play-based simulations ER - TY - JOUR AU - Zscherp, Mario Fabian AU - Jentsch, Silas Aurel AU - Müller, Marius Johannes AU - Lider, Vitalii AU - Becker, Celina AU - Chen, Limei AU - Littmann, Mario AU - Meier, Falco AU - Beyer, Andreas AU - Hofmann, Detlev Michael AU - As, Donat Josef AU - Klar, Peter Jens AU - Volz, Kerstin AU - Chatterjee, Sangam AU - Schörmann, Jörg ID - 46741 IS - 33 JF - ACS Applied Materials & Interfaces KW - General Materials Science SN - 1944-8244 TI - Overcoming the Miscibility Gap of GaN/InN in MBE Growth of Cubic InxGa1–xN VL - 15 ER - TY - CONF AU - Müller, Michelle AU - Neumann, Jürgen ID - 33722 T2 - Proceedings of the 55th Hawaii International Conference on System Sciences (HICSS) TI - Bring me my Meal on your Wheel - An Empirical Analysis of the Impact of Food Delivery Platforms on Local Restaurant Employment ER - TY - JOUR AB - AbstractWorking conditions of knowledge workers have been subject to rapid change recently. Digital nomadism is no longer a phenomenon that relates only to entrepreneurs, freelancers, and gig workers. Corporate employees, too, have begun to uncouple their work from stationary (home) offices and 9-to-5 schedules. However, pursuing a permanent job in a corporate environment is still subject to fundamentally different values than postulated by the original notion of digital nomadism. Therefore, this paper explores the work identity of what is referred to as ‘corporate nomads’. By drawing on identity theory and the results of semi-structured interviews, the paper proposes a conceptualization of the corporate nomad archetype and presents nine salient identity issues of corporate nomads (e.g., holding multiple contradictory identities, the flexibility paradox, or collaboration constraints). By introducing the ‘corporate nomad’ archetype to the Information Systems literature, this article helps to rethink established conceptions of “home office” and socio-spatial configurations of knowledge work. AU - Marx, Julian AU - Stieglitz, Stefan AU - Brünker, Felix AU - Mirbabaie, Milad ID - 44143 JF - Business & Information Systems Engineering KW - Information Systems SN - 2363-7005 TI - Home (Office) is where your Heart is ER - TY - JOUR AU - Zander, K.K. AU - Nguyen, D. AU - Mirbabaie, Milad AU - Garnett, S.T. ID - 46487 JF - International Journal of Disaster Risk Reduction KW - Geology KW - Safety Research KW - Geotechnical Engineering and Engineering Geology KW - Building and Construction SN - 2212-4209 TI - Aware but not prepared: understanding situational awareness during the century flood in Germany in 2021 VL - 96 ER - TY - BOOK AB - In the proposal for our CRC in 2011, we formulated a vision of markets for IT services that describes an approach to the provision of such services that was novel at that time and, to a large extent, remains so today: „Our vision of on-the-fly computing is that of IT services individually and automatically configured and brought to execution from flexibly combinable services traded on markets. At the same time, we aim at organizing markets whose participants maintain a lively market of services through appropriate entrepreneurial actions.“ Over the last 12 years, we have developed methods and techniques to address problems critical to the convenient, efficient, and secure use of on-the-fly computing. Among other things, we have made the description of services more convenient by allowing natural language input, increased the quality of configured services through (natural language) interaction and more efficient configuration processes and analysis procedures, made the quality of (the products of) providers in the marketplace transparent through reputation systems, and increased the resource efficiency of execution through reconfigurable heterogeneous computing nodes and an integrated treatment of service description and configuration. We have also developed network infrastructures that have a high degree of adaptivity, scalability, efficiency, and reliability, and provide cryptographic guarantees of anonymity and security for market participants and their products and services. To demonstrate the pervasiveness of the OTF computing approach, we have implemented a proof-of-concept for OTF computing that can run typical scenarios of an OTF market. We illustrated the approach using a cutting-edge application scenario – automated machine learning (AutoML). Finally, we have been pushing our work for the perpetuation of On-The-Fly Computing beyond the SFB and sharing the expertise gained in the SFB in events with industry partners as well as transfer projects. This work required a broad spectrum of expertise. Computer scientists and economists with research interests such as computer networks and distributed algorithms, security and cryptography, software engineering and verification, configuration and machine learning, computer engineering and HPC, microeconomics and game theory, business informatics and management have successfully collaborated here. AU - Haake, Claus-Jochen AU - Meyer auf der Heide, Friedhelm AU - Platzner, Marco AU - Wachsmuth, Henning AU - Wehrheim, Heike ID - 45863 TI - On-The-Fly Computing -- Individualized IT-services in dynamic markets VL - 412 ER - TY - JOUR AU - Stieglitz, Stefan AU - Mirbabaie, Milad AU - Deubel, Annika AU - Braun, Lea-Marie AU - Kissmer, Tobias ID - 45458 JF - International Journal of Information Management KW - Library and Information Sciences KW - Computer Networks and Communications KW - Information Systems SN - 0268-4012 TI - The potential of digital nudging to bridge the gap between environmental attitude and behavior in the usage of smart home applications VL - 72 ER - TY - JOUR AU - Mirbabaie, Milad AU - Marx, Julian AU - Erle, Lukas ID - 46746 JF - Pacific Asia Journal of the Association for Information Systems SN - 1943-7544 TI - Digital Nudge Stacking and Backfiring: Understanding Sustainable E-Commerce Purchase Decisions ER - TY - DATA AB - Die Energieaufnahme von Haushaltskältegeräten ist seit den 1990er Jahren erheblich gesunken. Dieser Wert wird von den Herstellern im Neuzustand der Geräte unter Normbedingungen bestimmt. Wie jedes technische System unterliegen jedoch auch Haushaltskältegeräte einem Alterungsprozess, der zu einem Anstieg der Energieaufnahme über die Zeit führt. Im Rahmen dieser Dissertation wurde auf der Grundlage von 100 Messungen der Energieaufnahme, die an 32 Geräten über einen Zeitraum von 21 Jahren durchgeführt wurden, ein Alterungsmodell entwickelt. Dieses Modell ist das erste, das mit Hilfe von Daten der Energieaufnahme real gealterter Geräte entwickelt wurde. Es beschreibt einen Anstieg der Energieaufnahme von 27 % über die durchschnittliche Einsatzzeit eines Haushaltskältegeräts von 16 Jahren. Der stärkste Anstieg erfolgt in den ersten fünf Betriebsjahren. Durch Diffusionsvorgänge in dem im Gehäuse verbauten Polyurethan-Schaum wird das im Zellgas vorhandene Kohlenstoffdioxid durch Luft ersetzt. Hierdurch steigt die Wärmeleitfähigkeit des Schaums um ca. 33 % an, wodurch sich die Energieaufnahme der Geräte erhöht. Des Weiteren wurde der Einsatz von Paraffinen als Phasenwechselmaterial in Haushaltskältegeräten untersucht. Durch deren Einsatz konnte die Energieaufnahme gesenkt und die Funktionalität der Geräte gesteigert werden. Hierfür sind detaillierte Kenntnisse der Materialkenndaten der Paraffine notwendig. Die Wärmeleitfähigkeit der verschiedenen Paraffin-Stoffgruppen in der festen Phase ist jedoch bisher nur unzureichend untersucht worden. Daher wurde ein Messaufbau entwickelt, mit dem die Wärmeleitfähigkeit von festem Paraffin bestimmt werden kann, und es wurden entsprechende Messungen durchgeführt. AU - Paul, Andreas ID - 46753 TI - Analyse von Alterungsmechanismen im Hinblick auf die Effizienz von Haushaltskältegeräten ER - TY - JOUR AB - Qualitative comparative analysis (QCA) enables researchers in international management to better understand how the impact of a single explanatory factor depends on the context of other factors. But the analytical toolbox of QCA does not include a parameter for the explanatory power of a single explanatory factor or “condition”. In this paper, we therefore reinterpret the Banzhaf power index, originally developed in cooperative game theory, to establish a goodness-of-fit parameter in QCA. The relative Banzhaf index we suggest measures the explanatory power of one condition averaged across all sufficient combinations of conditions. The paper argues that the index is especially informative in three situations that are all salient in international management and call for a context-sensitive analysis of single conditions, namely substantial limited diversity in the data, the emergence of strong INUS conditions in the analysis, and theorizing with contingency factors. The paper derives the properties of the relative Banzhaf index in QCA, demonstrates how the index can be computed easily from a rudimentary truth table, and explores its insights by revisiting selected papers in international management that apply fuzzy-set QCA. It finally suggests a three-step procedure for utilizing the relative Banzhaf index when the causal structure involves both contingency effects and configurational causation. AU - Haake, Claus-Jochen AU - Schneider, Martin ID - 34114 JF - Journal of International Management KW - Qualitative comparative analysis KW - Banzhaf power index KW - causality KW - explanatory power TI - Playing games with QCA: Measuring the explanatory power of single conditions with the Banzhaf index ER -