@unpublished{29835, author = {{Lanza, Lukas Johannes and Berger, Thomas}}, publisher = {{submitted to: IEEE Transactions on Automatic Control}}, title = {{{Funnel control of linear systems under output measurement losses}}}, year = {{2022}}, } @article{26747, abstract = {{Metasurfaces provide applications for a variety of flat elements and devices due to the ability to modulate light with subwavelength structures. The working principle meanwhile gives rise to the crucial problem and challenge to protect the metasurface from dust or clean the unavoidable contaminants during daily usage. Here, taking advantage of the intelligent bioinspired surfaces which exhibit self-cleaning properties, a versatile dielectric metasurface benefiting from the obtained superhydrophilic or quasi-superhydrophobic states is shown. The design is realized by embedding the metasurface inside a large area of wettability supporting structures, which is highly efficient in fabrication, and achieves both optical and wettability functionality at the same time. The superhydrophilic state enables an enhanced optical response with water, while the quasi-superhydrophobic state imparts the fragile antennas an ability to self-clean dust contamination. Furthermore, the metasurface can be easily switched and repeated between these two wettability or functional states by appropriate treatments in a repeatable way, without degrading the optical performance. The proposed design strategy will bring new opportunities to smart metasurfaces with improved optical performance, versatility, and physical stability.}}, author = {{Lu, Jinlong and Sain, Basudeb and Georgi, Philip and Protte, Maximilian and Bartley, Tim and Zentgraf, Thomas}}, issn = {{2195-1071}}, journal = {{Advanced Optical Materials}}, number = {{1}}, publisher = {{Wiley}}, title = {{{A Versatile Metasurface Enabling Superwettability for Self‐Cleaning and Dynamic Color Response}}}, doi = {{10.1002/adom.202101781}}, volume = {{10}}, year = {{2022}}, } @inproceedings{30236, abstract = {{Recent reinforcement learning approaches for continuous control in wireless mobile networks have shown impressive results. But due to the lack of open and compatible simulators, authors typically create their own simulation environments for training and evaluation. This is cumbersome and time-consuming for authors and limits reproducibility and comparability, ultimately impeding progress in the field. To this end, we propose mobile-env, a simple and open platform for training, evaluating, and comparing reinforcement learning and conventional approaches for continuous control in mobile wireless networks. mobile-env is lightweight and implements the common OpenAI Gym interface and additional wrappers, which allows connecting virtually any single-agent or multi-agent reinforcement learning framework to the environment. While mobile-env provides sensible default values and can be used out of the box, it also has many configuration options and is easy to extend. We therefore believe mobile-env to be a valuable platform for driving meaningful progress in autonomous coordination of wireless mobile networks.}}, author = {{Schneider, Stefan Balthasar and Werner, Stefan and Khalili, Ramin and Hecker, Artur and Karl, Holger}}, booktitle = {{IEEE/IFIP Network Operations and Management Symposium (NOMS)}}, keywords = {{wireless mobile networks, network management, continuous control, cognitive networks, autonomous coordination, reinforcement learning, gym environment, simulation, open source}}, location = {{Budapest}}, publisher = {{IEEE}}, title = {{{mobile-env: An Open Platform for Reinforcement Learning in Wireless Mobile Networks}}}, year = {{2022}}, } @inbook{16296, abstract = {{Multiobjective optimization plays an increasingly important role in modern applications, where several objectives are often of equal importance. The task in multiobjective optimization and multiobjective optimal control is therefore to compute the set of optimal compromises (the Pareto set) between the conflicting objectives. Since the Pareto set generally consists of an infinite number of solutions, the computational effort can quickly become challenging which is particularly problematic when the objectives are costly to evaluate as is the case for models governed by partial differential equations (PDEs). To decrease the numerical effort to an affordable amount, surrogate models can be used to replace the expensive PDE evaluations. Existing multiobjective optimization methods using model reduction are limited either to low parameter dimensions or to few (ideally two) objectives. In this article, we present a combination of the reduced basis model reduction method with a continuation approach using inexact gradients. The resulting approach can handle an arbitrary number of objectives while yielding a significant reduction in computing time.}}, author = {{Banholzer, Stefan and Gebken, Bennet and Dellnitz, Michael and Peitz, Sebastian and Volkwein, Stefan}}, booktitle = {{Non-Smooth and Complementarity-Based Distributed Parameter Systems}}, editor = {{Michael, Hintermüller and Roland, Herzog and Christian, Kanzow and Michael, Ulbrich and Stefan, Ulbrich}}, isbn = {{978-3-030-79392-0}}, pages = {{43--76}}, publisher = {{Springer}}, title = {{{ROM-Based Multiobjective Optimization of Elliptic PDEs via Numerical Continuation}}}, doi = {{10.1007/978-3-030-79393-7_3}}, year = {{2022}}, } @article{30195, abstract = {{While plasmonic particles can provide optical resonances in a wide spectral range from the lower visible up to the near-infrared, often, symmetry effects are utilized to obtain particular optical responses. By breaking certain spatial symmetries, chiral structures arise and provide robust chiroptical responses to these plasmonic resonances. Here, we observe strong chiroptical responses in the linear and nonlinear optical regime for chiral L-handed helicoid-III nanoparticles and quantify them by means of an asymmetric factor, the so-called g-factor. We calculate the linear optical g-factors for two distinct chiroptical resonances to −0.12 and –0.43 and the nonlinear optical g-factors to −1.45 and −1.63. The results demonstrate that the chirality of the helicoid-III nanoparticles is strongly enhanced in the nonlinear regime.}}, author = {{Spreyer, Florian and Mun, Jungho and Kim, Hyeohn and Kim, Ryeong Myeong and Nam, Ki Tae and Rho, Junsuk and Zentgraf, Thomas}}, issn = {{2330-4022}}, journal = {{ACS Photonics}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Biotechnology, Electronic, Optical and Magnetic Materials}}, number = {{3}}, pages = {{784–792}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Second Harmonic Optical Circular Dichroism of Plasmonic Chiral Helicoid-III Nanoparticles}}}, doi = {{10.1021/acsphotonics.1c00882}}, volume = {{9}}, year = {{2022}}, } @inproceedings{30387, abstract = {{Resonant evanescent coupling can be utilized to selectively excite orbital angular momentum (OAM) modes of high angular order supported by a thin circular dielectric rod. Our 2.5-D hybrid-analytical coupled mode model combines the vectorial fields associated with the fundamental TE- and TM-modes of a standard silicon photonics slab waveguide, propagating at oblique angles with respect to the rod axis, and the hybrid modes supported by the rod. One observes an efficient resonant interaction in cases where the common axial wavenumber of the waves in the slab matches the propagation constant of one or more modes of the rod. For certain modes of high angular order, the incident wave is able to transfer its directionality to the field in the fiber, exciting effectively only one of a pair of degenerate OAM modes}}, author = {{Hammer, Manfred and Ebers, Lena and Förstner, Jens}}, booktitle = {{Complex Light and Optical Forces XVI}}, editor = {{Andrews, David L. and Galvez, Enrique J. and Rubinsztein-Dunlop, Halina}}, keywords = {{tet_topic_waveguide}}, pages = {{120170F}}, publisher = {{SPIE}}, title = {{{Resonant evanescent excitation of OAM modes in a high-contrast circular step-index fiber}}}, doi = {{10.1117/12.2612179}}, year = {{2022}}, } @misc{30737, author = {{Schulz, Michael and Neuhaus, Uwe and Kaufmann, Jens and Kühnel, Stephan and Alekozai, Emal M. and Rohde, Heiko and Hoseini, Sayed and Theuerkauf, René and Badura, Daniel and Kerzel, Ulrich and Lanquillon, Carsten and Daurer, Stephan and Günther, Maik and Huber, Lukas and Thiée, Lukas-Walter and zur Heiden, Philipp and Passlick, Jens and Dieckmann, Jonas and Schwade, Florian and Seyffarth, Tobias and Badewitz, Wolfgang and Rissler, Raphael and Sackmann, Stefan and Gölzer, Philipp and Welter, Felix and Röth, Jochen and Seidelmann, Julian and Haneke, Uwe}}, publisher = {{NORDAKADEMIE gAG Hochschule der Wirtschaft}}, title = {{{DASC-PM v1.1 - Ein Vorgehensmodell für Data-Science-Projekte}}}, year = {{2022}}, } @article{30917, abstract = {{We study lobby group formation in a two-stage model where the players rst form lobby groups that then engage in a rent-seeking contest to inuence the legislator. However, the outcome of the contest aects all players according to the ideological distance between the implemented policy and the players' preferences. The players can either lobby by themselves, form a coalition of lobbyists or free ride. We nd that free coalition formation is reasonable if either players with moderate preferences face lobby groups with extreme preferences, or if there are two opposing coalitions with an equal number of members. Otherwise, there are always free riders among the players.}}, author = {{Block, Lukas}}, journal = {{Quick And Easy Journal Title}}, keywords = {{Group formation, Rent-seeking, Free riding}}, title = {{{Coalition formation versus free riding in rent-seeking contests}}}, year = {{2022}}, } @article{29902, author = {{Reineke Matsudo, Bernhard and Sain, Basudeb and Carletti, Luca and Zhang, Xue and Gao, Wenlong and Angelis, Costantino and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2198-3844}}, journal = {{Advanced Science}}, keywords = {{General Physics and Astronomy, General Engineering, Biochemistry, Genetics and Molecular Biology (miscellaneous), General Materials Science, General Chemical Engineering, Medicine (miscellaneous)}}, number = {{12}}, publisher = {{Wiley}}, title = {{{Efficient Frequency Conversion with Geometric Phase Control in Optical Metasurfaces}}}, doi = {{10.1002/advs.202104508}}, volume = {{9}}, year = {{2022}}, } @inbook{29928, author = {{Yigitbas, Enes and Sauer, Stefan and Engels, Gregor}}, booktitle = {{Digital Transformation: Core Technologies and Emerging Topics from a Computer Science Perspective}}, editor = {{Vogel-Heuser, Birgit and Wimmer, Manuel}}, publisher = {{Springer-Vieweg}}, title = {{{Self-Adaptive Digital Assistance Systems for Work 4.0}}}, year = {{2022}}, } @article{30964, author = {{Gao, Wenlong and Sain, Basudeb and Zentgraf, Thomas}}, issn = {{2331-7019}}, journal = {{Physical Review Applied}}, keywords = {{General Physics and Astronomy}}, number = {{4}}, publisher = {{American Physical Society (APS)}}, title = {{{Spin-Orbit Interaction of Light Enabled by Negative Coupling in High-Quality-Factor Optical Metasurfaces}}}, doi = {{10.1103/physrevapplied.17.044022}}, volume = {{17}}, year = {{2022}}, } @article{23398, abstract = {{We study output reference tracking of systems with high relative degree via output feedback only; this is, tracking where the output derivatives are unknown. To this end, we prove that the conjunction of the funnel pre-compensator with a minimum phase system of arbitrary relative degree yields a system of the same relative degree which is minimum phase as well. The error between the original system's output and the pre-compensator's output evolves within a prescribed performance funnel; and moreover, the derivatives of the funnel pre-compensator's output are known explicitly. Therefore, output reference tracking with prescribed transient behavior of the tracking error is possible without knowledge of the derivatives of the original system's output; via funnel control schemes for instance.}}, author = {{Lanza, Lukas Johannes}}, journal = {{Mathematics of Control, Signals, and Systems}}, title = {{{Output feedback control with prescribed performance via funnel pre-compensator}}}, doi = {{10.1007/s00498-022-00322-5}}, year = {{2022}}, } @article{32180, author = {{Meschede, Henning and Bertheau, Paul and Khalili, Siavash and Breyer, Christian}}, issn = {{2041-8396}}, journal = {{WIREs Energy and Environment}}, keywords = {{General Environmental Science, Renewable Energy, Sustainability and the Environment}}, publisher = {{Wiley}}, title = {{{A review of 100% renewable energy scenarios on islands}}}, doi = {{10.1002/wene.450}}, year = {{2022}}, } @inproceedings{29842, abstract = {{To build successful software products, developers continuously have to discover what features the users really need. This discovery can be achieved with continuous experimentation, testing different software variants with distinct user groups, and deploying the superior variant for all users. However, existing approaches do not focus on explicit modeling of variants and experiments, which offers advantages such as traceability of decisions and combinability of experiments. Therefore, our vision is the provision of model-driven continuous experimentation, which provides the developer with a framework for structuring the experimentation process. For that, we introduce the overall concept, apply it to the experimentation on component-based software architectures and point out future research questions. In particular, we show the applicability by combining feature models for modeling the software variants, users, and experiments (i.e., model-driven) with MAPE-K for the adaptation (i.e., continuous experimentation) and implementing the concept based on the component-based Angular framework.}}, author = {{Gottschalk, Sebastian and Yigitbas, Enes and Engels, Gregor}}, booktitle = {{Proceedings of the 18th International Conference on Software Architecture Companion }}, keywords = {{continuous experimentation, model-driven, component-based software architectures, self-adaptation}}, location = {{Hawaii}}, publisher = {{IEEE}}, title = {{{Model-driven Continuous Experimentation on Component-based Software Architectures }}}, doi = {{10.1109/ICSA-C54293.2022.00011}}, year = {{2022}}, } @article{29673, abstract = {{Koopman operator theory has been successfully applied to problems from various research areas such as fluid dynamics, molecular dynamics, climate science, engineering, and biology. Applications include detecting metastable or coherent sets, coarse-graining, system identification, and control. There is an intricate connection between dynamical systems driven by stochastic differential equations and quantum mechanics. In this paper, we compare the ground-state transformation and Nelson's stochastic mechanics and demonstrate how data-driven methods developed for the approximation of the Koopman operator can be used to analyze quantum physics problems. Moreover, we exploit the relationship between Schrödinger operators and stochastic control problems to show that modern data-driven methods for stochastic control can be used to solve the stationary or imaginary-time Schrödinger equation. Our findings open up a new avenue towards solving Schrödinger's equation using recently developed tools from data science.}}, author = {{Klus, Stefan and Nüske, Feliks and Peitz, Sebastian}}, journal = {{Journal of Physics A: Mathematical and Theoretical}}, number = {{31}}, pages = {{314002}}, publisher = {{IOP Publishing Ltd.}}, title = {{{Koopman analysis of quantum systems}}}, doi = {{10.1088/1751-8121/ac7d22}}, volume = {{55}}, year = {{2022}}, } @article{34132, abstract = {{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?}}, author = {{Steinhardt, Isabel and Kruschick, Felicitas}}, issn = {{2367-7163}}, journal = {{Research Ideas and Outcomes}}, keywords = {{Open Science, Knowledge Equity, Qualitative Methods}}, publisher = {{Pensoft Publishers}}, title = {{{Knowledge Equity and Open Science in qualitative research – Practical research considerations}}}, doi = {{10.3897/rio.8.e86387}}, volume = {{8}}, year = {{2022}}, } @phdthesis{29769, abstract = {{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.}}, author = {{Ahmed, Qazi Arbab}}, keywords = {{FPGA Security, Hardware Trojans, Bitstream-level Trojans, Bitstream Verification}}, publisher = {{ Paderborn University, Paderborn, Germany}}, title = {{{Hardware Trojans in Reconfigurable Computing}}}, doi = {{10.17619/UNIPB/1-1271}}, year = {{2022}}, } @article{33669, abstract = {{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.}}, author = {{Zhang, Wangyou and Chang, Xuankai and Boeddeker, Christoph and Nakatani, Tomohiro and Watanabe, Shinji and Qian, Yanmin}}, issn = {{Print ISSN: 2329-9290 Electronic ISSN: 2329-9304}}, journal = {{IEEE/ACM Transactions on Audio, Speech, and Language Processing}}, title = {{{End-to-End Dereverberation, Beamforming, and Speech Recognition in A Cocktail Party}}}, doi = {{10.1109/TASLP.2022.3209942}}, year = {{2022}}, } @article{34198, author = {{Bloh, Thiemo and Caruso, Carina}}, journal = {{die hochschullehre}}, title = {{{Ein kritisch-multiperspektivischer Blick auf Forschendes Lernen in der Lehrkräftebildung. Fragen, Erwägungen und Rekonstruktionen.}}}, doi = {{10.3278/HSL2221W}}, volume = {{8}}, year = {{2022}}, } @phdthesis{34272, abstract = {{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.}}, author = {{Schemmel, Reinhard}}, isbn = {{ 978-3-8440-8527-3}}, pages = {{174}}, publisher = {{Shaker}}, title = {{{Enhanced process development by simulation of ultrasonic heavy wire bonding}}}, doi = {{10.17619/UNIPB/1-1280}}, volume = {{13}}, year = {{2022}}, }