@article{28196, abstract = {{We show that narrow trenches in a high-contrast silicon-photonics slab can act as lossless power dividers for semi-guided waves. Reflectance and transmittance can be easily configured by selecting the trench width. At sufficiently high angles of incidence, the devices are lossless, apart from material attenuation and scattering due to surface roughness. We numerically simulate a series of devices within the full 0-to-1-range of splitting ratios, for semi-guided plane wave incidence as well as for excitation by focused Gaussian wave bundles. Straightforward cascading of the trenches leads to concepts for 1×M-power dividers and a polarization beam splitter.}}, author = {{Hammer, Manfred and Ebers, Lena and Förstner, Jens}}, issn = {{2578-7519}}, journal = {{OSA Continuum}}, keywords = {{tet_topic_waveguide}}, number = {{12}}, pages = {{3081}}, title = {{{Configurable lossless broadband beam splitters for semi-guided waves in integrated silicon photonics}}}, doi = {{10.1364/osac.437549}}, volume = {{4}}, year = {{2021}}, } @techreport{33854, abstract = {{Macrodiversity is a key technique to increase the capacity of mobile networks. It can be realized using coordinated multipoint (CoMP), simultaneously connecting users to multiple overlapping cells. Selecting which users to serve by how many and which cells is NP-hard but needs to happen continuously in real time as users move and channel state changes. Existing approaches often require strict assumptions about or perfect knowledge of the underlying radio system, its resource allocation scheme, or user movements, none of which is readily available in practice. Instead, we propose three novel self-learning and self-adapting approaches using model-free deep reinforcement learning (DRL): DeepCoMP, DD-CoMP, and D3-CoMP. DeepCoMP leverages central observations and control of all users to select cells almost optimally. DD-CoMP and D3-CoMP use multi-agent DRL, which allows distributed, robust, and highly scalable coordination. All three approaches learn from experience and self-adapt to varying scenarios, reaching 2x higher Quality of Experience than other approaches. They have very few built-in assumptions and do not need prior system knowledge, making them more robust to change and better applicable in practice than existing approaches.}}, author = {{Schneider, Stefan Balthasar and Karl, Holger and Khalili, Ramin and Hecker, Artur}}, keywords = {{mobility management, coordinated multipoint, CoMP, cell selection, resource management, reinforcement learning, multi agent, MARL, self-learning, self-adaptation, QoE}}, title = {{{DeepCoMP: Coordinated Multipoint Using Multi-Agent Deep Reinforcement Learning}}}, year = {{2021}}, } @misc{35066, author = {{Süßmann, Johannes}}, title = {{{Mariemont – Modernismus und Erinnerung. Videographierter Vortrag für den 5. Belgientag des Belgienzentrums Paderborn ›Belgien – Pralle Kunst des Lebens‹ am 18. Mai 2021}}}, year = {{2021}}, } @article{21265, abstract = {{Fast-growing energy demand of the world makes the researchers focus on finding new energy sources or optimizing already-developed approaches. For an efficient use of solar and wind energy in an energy system, correct design and sizing of a power system is of high importance and improving or optimizing the process of data obtaining for this purpose leads to higher performance and lower cost per unit of energy. It is essential to have the most precise possible estimation of solar and wind energy potential and other local weather parameters in order to fully feed the demand and avoid extra costs. There are various methods for obtaining local data, such as local measurements, official organizational data, satellite obtained, and reanalysis data. In this paper, the Modern-Era Retrospective analysis for Research and Applications dataset version 2 (MERRA-2) dataset provided by NASA is introduced and its performance is evaluated by comparison to various locally measured datasets offered by meteorological institutions such as Meteonorm and Deutscher Wetterdienst (DWD, or Germany’s National Meteorological Service) around the world. After comparison, correlation coefficients from 0.95 to 0.99 are observed for monthly global horizontal irradiance values. In the case of air temperature, correlation coefficients of 0.99 and for wind speed from 0.81 to 0.99 are observed. High correlation with ground measurements and relatively low errors are confirmed, especially for irradiance and temperature values, that makes MERRA-2 a valuable dataset, considering its world coverage and availability.}}, author = {{Khatibi, Arash and Krauter, Stefan}}, issn = {{1996-1073}}, journal = {{Energies}}, keywords = {{Solar irradiance, MERRA 2, Meteonorm, DWD}}, number = {{4}}, publisher = {{MDPI}}, title = {{{Validation and Performance of Satellite Meteorological Dataset MERRA-2 for Solar and Wind Applications}}}, doi = {{10.3390/en14040882}}, volume = {{14}}, year = {{2021}}, } @article{26987, abstract = {{Optical metasurfaces are perfect candidates for the phase and amplitude modulation of light, featuring an excellent basis for holographic applications. In this work, we present a dual amplitude holographic scheme based on the photon sieve principle, which is then combined with a phase hologram by utilizing the Pancharatnam–Berry phase. We demonstrate that two types of apertures, rectangular and square shapes in a gold film filled with silicon nanoantennas are sufficient to create two amplitude holograms at two different wavelengths in the visible, multiplexed with an additional phase-only hologram. The nanoantennas are tailored to adjust the spectral transmittance of the apertures, enabling the wavelength sensitivity. The phase-only hologram is implemented by utilizing the anisotropic rectangular structure. Interestingly, such three holograms have quantitative mathematical correlations with each other. Thus, the flexibility of polarization and wavelength channels can be utilized with custom-tailored features to achieve such amplitude and phase holography simultaneously without sacrificing any space-bandwidth product. The present scheme has the potential to store different pieces of information which can be displayed separately by switching the wavelength or the polarization state of the reading light beam.}}, author = {{Frese, Daniel and Sain, Basudeb and Zhou, Hongqiang and Wang, Yongtian and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2192-8614}}, journal = {{Nanophotonics}}, number = {{18}}, pages = {{4543--4550}}, publisher = {{De Gruyter}}, title = {{{A wavelength and polarization selective photon sieve for holographic applications}}}, doi = {{10.1515/nanoph-2021-0440}}, volume = {{10}}, year = {{2021}}, } @article{16294, abstract = {{Model predictive control is a prominent approach to construct a feedback control loop for dynamical systems. Due to real-time constraints, the major challenge in MPC is to solve model-based optimal control problems in a very short amount of time. For linear-quadratic problems, Bemporad et al. have proposed an explicit formulation where the underlying optimization problems are solved a priori in an offline phase. In this article, we present an extension of this concept in two significant ways. We consider nonlinear problems and - more importantly - problems with multiple conflicting objective functions. In the offline phase, we build a library of Pareto optimal solutions from which we then obtain a valid compromise solution in the online phase according to a decision maker's preference. Since the standard multi-parametric programming approach is no longer valid in this situation, we instead use interpolation between different entries of the library. To reduce the number of problems that have to be solved in the offline phase, we exploit symmetries in the dynamical system and the corresponding multiobjective optimal control problem. The results are verified using two different examples from autonomous driving.}}, author = {{Ober-Blöbaum, Sina and Peitz, Sebastian}}, journal = {{International Journal of Robust and Nonlinear Control}}, pages = {{380--403}}, title = {{{Explicit multiobjective model predictive control for nonlinear systems with symmetries}}}, doi = {{10.1002/rnc.5281}}, volume = {{31(2)}}, year = {{2021}}, } @misc{29549, abstract = {{Als Griechenland 1830 seine Unabhängigkeit erlangte, war das Land wirtschaftlich wenig entwickelt und von der Industrialisierung noch kaum berührt. Kredite für die Gründung oder den Ausbau von Unternehmen waren auf Grund des Kapitalmangels entweder unmöglich oder extrem teuer – ein für die wirtschaftliche Entwicklung ernst zu nehmendes Hemmnis. Das Land brauchte zur wirtschaftlichen Entwicklung also Investitionen aus dem Ausland. Jedoch hielten sich die europäischen Banken und Anleger mit solchen Investitionen vor den 1870er Jahren zurück. Warum diese Scheu der Kapitalanleger vor Griechenland, obwohl sie anderswo keineswegs vor risikoreichen Investitionen zurückschreckten, wenn nur entsprechend hohe Erträge lockten? Dieser Frage möchte der Beitrag anhand eines Beispiels nachgehen: der bayerisch-französischen Bankiersfamilie von Eichthal, die in den 1830er Jahren enge Geschäftsbeziehungen nach Griechenland aufbaute und zeitweilig sehr interessiert an Investitionen war – bevor das Bankhaus sich von diesen Plänen schließlich unverrichteter Dinge wieder abwandte. Das kulturelle Interesse an Griechenland überdauerte dagegen bis in die 1880er Jahre. Die Eichthals eignen sich hervorragend, um paradigmatisch zu untersuchen, auf welcher Grundlage und wie europäische Bankiers ihre Investitionsentscheidungen für oder gegen Griechenland trafen.}}, author = {{Schönhärl, Korinna}}, title = {{{Finanzielle Netze. Die bayerisch–französische Familienbank von Eichthal und ihre Investitionspläne in Griechenland in den 1830er Jahren/ Οικονομικά δίκτυα. Η βαυαρογαλλική οικογενειακή τράπεζα των Άιχταλ και τα επενδυτικά σχέδιά της στην Ελλάδα κατά τη δεκαετία του 1830}}}, year = {{2021}}, } @unpublished{22764, abstract = {{Robotics applications process large amounts of data in real-time and require compute platforms that provide high performance and energy-efficiency. FPGAs are well-suited for many of these applications, but there is a reluctance in the robotics community to use hardware acceleration due to increased design complexity and a lack of consistent programming models across the software/hardware boundary. In this paper we present ReconROS, a framework that integrates the widely-used robot operating system (ROS) with ReconOS, which features multithreaded programming of hardware and software threads for reconfigurable computers. This unique combination gives ROS2 developers the flexibility to transparently accelerate parts of their robotics applications in hardware. We elaborate on the architecture and the design flow for ReconROS and report on a set of experiments that underline the feasibility and flexibility of our approach.}}, author = {{Lienen, Christian and Platzner, Marco}}, booktitle = {{arXiv:2107.07208}}, pages = {{19}}, title = {{{Design of Distributed Reconfigurable Robotics Systems with ReconROS}}}, year = {{2021}}, } @inproceedings{25880, author = {{Hetkämper, Tim and Dreiling, Dmitrij and Claes, Leander and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2021}}, title = {{{Tomographie des Schallfelds von Ultraschallwandlern mittels Schlierentechnik}}}, year = {{2021}}, } @misc{31385, author = {{Hoffmann, Max}}, booktitle = {{Mathematische Semesterberichte}}, pages = {{295–297}}, title = {{{Rezension: Hendrik Kasten und Denis Vogel: Grundlagen der ebenen Geometrie – Eine zugängliche aber exakte Einführung in die ebene Geometrie}}}, doi = {{10.1007/s00591-021-00299-3}}, volume = {{68}}, year = {{2021}}, } @article{24955, author = {{Woitkowski, David and Rochell, Leonie and Bauer, Anna}}, issn = {{2469-9896}}, journal = {{Physical Review Physics Education Research}}, title = {{{German university students’ views of nature of science in the introductory phase}}}, doi = {{10.1103/physrevphyseducres.17.010118}}, year = {{2021}}, } @inproceedings{21726, author = {{Triebus, Marcel and Tröster, Thomas}}, booktitle = {{9th NRW Nano Conference - Innovations in Materials and Applications}}, location = {{Web}}, title = {{{HyOpt - Optimization-Based Development of Hybrid Materials}}}, year = {{2021}}, } @inproceedings{28988, author = {{Kirchhoff, Jonas}}, booktitle = {{The 1st Early Career Researchers Workshop Co-Located with ECSS 2021}}, location = {{Madrid}}, title = {{{Providing Decision Makers with Tailored Decision Support Systems}}}, year = {{2021}}, } @article{32558, abstract = {{With the rapid progress of technological development, self-efficacy in reference to digital devices (i.e., information and computer technology [ICT] self-efficacy) is an important driver that helps students to deal with technological problems and support their lifelong learning processes. Schools, peers, and home learning environments are important sources for the development of positive self-efficacy. Expanding on previous research, we investigated the associations between different aspects of the digital home learning environment and students’ ICT self-efficacy. The moderation effects of gender were also tested. A total of 651 children answered a questionnaire about different digital home learning environment dimensions and estimated their ICT self-efficacy using an adapted scale—Schwarzer and Jerusalem’s (1999) general self-efficacy scale. Using the structural equation modeling technique, a digital home learning environment containing six different qualities of parental support was investigated. Families’ cultural capital, parents’ attitudes toward the Internet, and shared Internet activities at home contributed positively to ICT self-efficacy. We observed small gender differences, with the moderation effect being nonsignificant. The results help researchers and practitioners to understand how different dimensions of the digital home learning environment support ICT self-efficacy. We will discuss how parents can enhance the home learning environment and how teachers can integrate this knowledge into formal education.}}, author = {{Bonanati, Sabrina and Buhl, Heike M.}}, issn = {{1387-1579}}, journal = {{Learning Environments Research}}, keywords = {{Digital media use, Gender, Home learning environment, ICT self-efcacy, Motivation, Parental involvement}}, number = {{2}}, pages = {{485--505}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{The digital home learning environment and its relation to children’s ICT self-efficacy}}}, doi = {{10.1007/s10984-021-09377-8}}, volume = {{25}}, year = {{2021}}, } @article{32560, abstract = {{Several methods are available to answer questions regarding similarity and accuracy, each of which has specific properties and limitations. This study focuses on the Latent Congruence Model (LCM; Cheung, 2009), because of its capacity to deal with cross-informant measurement invariance issues. Until now, no cross-national applications of LCM are present in the literature, perhaps because of the difficulty to deal with both cross-national and cross-informant measurement issues implied by those models. This study presents a step-by-step procedure to apply LCM to dyadic cross-national research designs controlling for both cross-national and cross-informant measurement invariance. An illustrative example on parent–child support exchanges in Italy and Germany is provided. Findings help to show the different possible scenarios of partial invariance, and a discussion related to how to deal with those scenarios is provided. Future perspectives in the study of parent–child similarity and accuracy in cross-national research will be discussed.}}, author = {{Tagliabue, Semira and Zambelli, Michela and Sorgente, Angela and Sommer, Sabrina and Hoellger, Christian and Buhl, Heike M. and Lanz, Margherita}}, issn = {{1664-1078}}, journal = {{Frontiers in Psychology}}, keywords = {{latent congruence model, measurement invariance, similarity, accuracy, cross-national, cross-informant, parent-child relationship, support exchanges}}, publisher = {{Frontiers Media SA}}, title = {{{Latent Congruence Model to Investigate Similarity and Accuracy in Family Members' Perception: The Challenge of Cross-National and Cross-Informant Measurement (Non)Invariance}}}, doi = {{10.3389/fpsyg.2021.672383}}, volume = {{12}}, year = {{2021}}, } @article{32561, abstract = {{This investigation concentrates on the association of intergenerational value similarity and adult children’s and parents’subjective well-being, on the linkage between relationship quality and subjective well-being. Mediation effects of the relationship quality on the associations between value similarity and subjective well-being were focused. The sample consisted of 600 adult German children (53.8% women) and their parents. Dyadic correlations were constructed to determine the value similarity. In this study, the general value orientation and the family values were objects of research. We measured the subjective well-being with the Satisfaction with Life Scale and we used the Network of Relationships Inventory (NRI) to measure the relationship quality. Associations between subjective well-being and value similarity, and between subjective well-being and relationship quality, as well as mediation effects, were found. All effects depend on gender and perspective.}}, author = {{Hoellger, Christian and Sommer, Sabrina and Buhl, Heike M.}}, issn = {{0192-513X}}, journal = {{Journal of Family Issues}}, keywords = {{adult child–parent dyads, relationship quality, life satisfaction, parent–child relationship, intergenerational stake hypothesis, mediation analyses}}, publisher = {{SAGE Publications}}, title = {{{Intergenerational Value Similarity and Subjective Well-Being}}}, doi = {{10.1177/0192513x211054470}}, year = {{2021}}, } @inproceedings{23758, author = {{Peeters, Hendrik and Habig, Sebastian and Fechner, Sabine}}, booktitle = {{Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch?}}, editor = {{Habig, Sebastian}}, keywords = {{digitale Medien}}, pages = {{613--616}}, title = {{{Augmented Reality als Experimentierhilfe bei Beobachtung und Deutung}}}, volume = {{41}}, year = {{2021}}, } @phdthesis{21502, abstract = {{Die vollständige Beschreibung fluiddynamischer und akustischer Vorgänge setzt voraus, dass die Eigenschaften des Fluids hinlänglich bekannt sind.Während Fluidkenngrößen, wie etwa die Schallgeschwindigkeit oder die Scherviskosität, für viele Flüssigkeiten über weite Bereiche des thermodynamischen Zustandsraums bekannt sind, existieren für die Volumenviskosität nur eine geringe Anzahl Messdaten.In dieser Arbeit wird daher ein Messverfahren zur selektiven Bestimmung der Volumenviskosität von Flüssigkeiten, basierend auf der Absorption von Ultraschallwellen, entwickelt und realisiert.Schwerpunkte bilden dabei der simulationsgestützte Entwurf von Algorithmen zur Auswertung der Messsignale sowie die Analyse und Weiterentwicklung einer Messanordnung, basierend auf dem Puls-Echo-Verfahren. Neben der Absorption im Fluid treten dabei weitere Effekte (zum Beispiel Beugung oder unvollständige Reflexion) auf, die das akustische Signal schwächen oder anderweitig beeinflussen. Die Entwicklung von Verfahren zur Trennung dieser Effekte von der akustischen Absorption bildet daher einen weiteren Schwerpunkt dieser Arbeit.Abschließend wird die Volumenviskosität aus der gemessenen akustischen Absorption für unterschiedliche Fluide in verschiedenen thermodynamischen Zuständen unter Zuhilfenahme anderer bekannter Fluidkenngrößen bestimmt sowie eine Unsicherheitsbetrachtung durchgeführt.}}, author = {{Claes, Leander}}, pages = {{223}}, publisher = {{Universiät Paderborn}}, title = {{{Messverfahren für die akustische Absorption in reinen Fluiden zur Bestimmung der Volumenviskosität}}}, doi = {{10.17619/UNIPB/1-1104}}, year = {{2021}}, } @article{33278, abstract = {{The kinetic Brownian motion on the sphere bundle of a Riemannian manifold M is a stochastic process that models a random perturbation of the geodesic flow. If M is an orientable compact constantly curved surface, we show that in the limit of infinitely large perturbation the L2-spectrum of the infinitesimal generator of a time-rescaled version of the process converges to the Laplace spectrum of the base manifold.}}, author = {{Kolb, Martin and Weich, Tobias and Wolf, Lasse}}, journal = {{Annales Henri Poincaré }}, number = {{4}}, pages = {{1283--1296}}, publisher = {{Springer Science + Business Media}}, title = {{{Spectral Asymptotics for Kinetic Brownian Motion on Surfaces of Constant Curvature}}}, volume = {{23}}, year = {{2021}}, } @unpublished{32099, author = {{Weich, Tobias and Budde, Julia}}, booktitle = {{arXiv:2103.02968v1}}, title = {{{Wave Front Sets of Nilpotent Lie Group Representations}}}, year = {{2021}}, } @article{33372, abstract = {{Academics may actively respond to the expectations of the academic status market, which have largely been shaped by the World University Rankings (WURs). This study empirically examines how academics’ citation patterns have changed in response to the rise of an “evaluation environment” in academia. We regard the WURs to be a macro-level trigger for cementing a bibliometric-based evaluation environment in academia. Our analyses of citation patterns in papers published in two higher education journals explicitly considered three distinct periods: the pre-WURs (1990–2003), the period of WURs implementation (2004–2010), and the period of adaption to WURs (2011–2017). We applied the nonparametric Kaplan–Meier method to compare first-citation speeds of papers published across the three periods. We found that not only has first-citation speed become faster, but first-citation probability has also increased following the emergence of the WURs. Applying Cox proportional hazard models to first-citation probabilities, we identified journal impact factors and third-party funding as factors influencing first-citation probability, while other author- and paper-related factors showed limited effects. We also found that the general effects of different factors on first-citation speeds have changed with the emergence of the WURs. The findings expand our understanding of the citation patterns of academics in the rise of WURs and provide practical grounds for research policy as well as higher education policy.}}, author = {{Lee, Soo Jeung and Schneijderberg, Christian and Kim, Yangson and Steinhardt, Isabel}}, issn = {{2071-1050}}, journal = {{Sustainability}}, keywords = {{world university rankings, citation, first-citation speed, Minerva, Studies in Higher Education}}, number = {{17}}, publisher = {{MDPI AG}}, title = {{{Have Academics’ Citation Patterns Changed in Response to the Rise of World University Rankings? A Test Using First-Citation Speeds}}}, doi = {{10.3390/su13179515}}, volume = {{13}}, year = {{2021}}, } @inproceedings{29291, author = {{Zahera, Hamada Mohamed Abdelsamee and Heindorf, Stefan and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{Proceedings of the 11th on Knowledge Capture Conference}}, publisher = {{ACM}}, title = {{{ASSET: A Semi-supervised Approach for Entity Typing in Knowledge Graphs}}}, doi = {{10.1145/3460210.3493563}}, year = {{2021}}, } @inbook{29292, author = {{Feldhans, Robert and Wilke, Adrian and Heindorf, Stefan and Shaker, Mohammad Hossein and Hammer, Barbara and Ngonga Ngomo, Axel-Cyrille and Hüllermeier, Eyke}}, booktitle = {{Intelligent Data Engineering and Automated Learning – IDEAL 2021}}, isbn = {{9783030916077}}, issn = {{0302-9743}}, publisher = {{Springer International Publishing}}, title = {{{Drift Detection in Text Data with Document Embeddings}}}, doi = {{10.1007/978-3-030-91608-4_11}}, year = {{2021}}, } @inproceedings{29287, abstract = {{Knowledge graph embedding research has mainly focused on the two smallest normed division algebras, $\mathbb{R}$ and $\mathbb{C}$. Recent results suggest that trilinear products of quaternion-valued embeddings can be a more effective means to tackle link prediction. In addition, models based on convolutions on real-valued embeddings often yield state-of-the-art results for link prediction. In this paper, we investigate a composition of convolution operations with hypercomplex multiplications. We propose the four approaches QMult, OMult, ConvQ and ConvO to tackle the link prediction problem. QMult and OMult can be considered as quaternion and octonion extensions of previous state-of-the-art approaches, including DistMult and ComplEx. ConvQ and ConvO build upon QMult and OMult by including convolution operations in a way inspired by the residual learning framework. We evaluated our approaches on seven link prediction datasets including WN18RR, FB15K-237 and YAGO3-10. Experimental results suggest that the benefits of learning hypercomplex-valued vector representations become more apparent as the size and complexity of the knowledge graph grows. ConvO outperforms state-of-the-art approaches on FB15K-237 in MRR, Hit@1 and Hit@3, while QMult, OMult, ConvQ and ConvO outperform state-of-the-approaches on YAGO3-10 in all metrics. Results also suggest that link prediction performances can be further improved via prediction averaging. To foster reproducible research, we provide an open-source implementation of approaches, including training and evaluation scripts as well as pretrained models.}}, author = {{Demir, Caglar and Moussallem, Diego and Heindorf, Stefan and Ngonga Ngomo, Axel-Cyrille}}, booktitle = {{The 13th Asian Conference on Machine Learning, ACML 2021}}, title = {{{Convolutional Hypercomplex Embeddings for Link Prediction}}}, year = {{2021}}, } @inproceedings{29294, author = {{Nickchen, Tobias and Heindorf, Stefan and Engels, Gregor}}, booktitle = {{2021 IEEE Winter Conference on Applications of Computer Vision (WACV)}}, publisher = {{IEEE}}, title = {{{Generating Physically Sound Training Data for Image Recognition of Additively Manufactured Parts}}}, doi = {{10.1109/wacv48630.2021.00204}}, year = {{2021}}, } @misc{33733, author = {{Heindorf, Stefan}}, title = {{{Automatically generating instructions from tutorials for search and user navigation}}}, year = {{2021}}, } @article{23728, abstract = {{We demonstrate the integration of amorphous tungsten silicide superconducting nanowire single-photon detectors on titanium in-diffused lithium niobate waveguides. We show proof-of-principle detection of evanescently coupled photons of 1550 nm wavelength using bidirectional waveguide coupling for two orthogonal polarization directions. We investigate the internal detection efficiency as well as detector absorption using coupling-independent characterization measurements. Furthermore, we describe strategies to improve the yield and efficiency of these devices.}}, author = {{Höpker, Jan Philipp and Verma, Varun B and Protte, Maximilian and Ricken, Raimund and Quiring, Viktor and Eigner, Christof and Ebers, Lena and Hammer, Manfred and Förstner, Jens and Silberhorn, Christine and Mirin, Richard P and Woo Nam, Sae and Bartley, Tim}}, issn = {{2515-7647}}, journal = {{Journal of Physics: Photonics}}, pages = {{034022}}, title = {{{Integrated superconducting nanowire single-photon detectors on titanium in-diffused lithium niobate waveguides}}}, doi = {{10.1088/2515-7647/ac105b}}, volume = {{3}}, year = {{2021}}, } @article{25046, abstract = {{While increasing digitalization enables multiple advantages for a reliable operation of technical systems, a remaining challenge in the context of condition monitoring is seen in suitable consideration of uncertainties affecting the monitored system. Therefore, a suitable prognostic approach to predict the remaining useful lifetime of complex technical systems is required. To handle different kinds of uncertainties, a novel Multi-Model-Particle Filtering-based prognostic approach is developed and evaluated by the use case of rubber-metal-elements. These elements are maintained preventively due to the strong influence of uncertainties on their behavior. In this paper, two measurement quantities are compared concerning their ability to establish a prediction of the remaining useful lifetime of the monitored elements and the influence of present uncertainties. Based on three performance indices, the results are evaluated. A comparison with predictions of a classical Particle Filter underlines the superiority of the developed Multi-Model-Particle Filter. Finally, the value of the developed method for enabling condition monitoring of technical systems related to uncertainties is given exemplary by a comparison between the preventive and the predictive maintenance strategy for the use case.}}, author = {{Bender, Amelie}}, issn = {{2075-1702}}, journal = {{Machines}}, keywords = {{prognostics, RUL predictions, particle filter, uncertainty consideration, Multi-Model-Particle Filter, model-based approach, rubber-metal-elements, predictive maintenance}}, number = {{10}}, title = {{{A Multi-Model-Particle Filtering-Based Prognostic Approach to Consider Uncertainties in RUL Predictions}}}, doi = {{10.3390/machines9100210}}, volume = {{9}}, year = {{2021}}, } @techreport{35889, abstract = {{Network and service coordination is important to provide modern services consisting of multiple interconnected components, e.g., in 5G, network function virtualization (NFV), or cloud and edge computing. In this paper, I outline my dissertation research, which proposes six approaches to automate such network and service coordination. All approaches dynamically react to the current demand and optimize coordination for high service quality and low costs. The approaches range from centralized to distributed methods and from conventional heuristic algorithms and mixed-integer linear programs to machine learning approaches using supervised and reinforcement learning. I briefly discuss their main ideas and advantages over other state-of-the-art approaches and compare strengths and weaknesses.}}, author = {{Schneider, Stefan Balthasar}}, keywords = {{nfv, coordination, machine learning, reinforcement learning, phd, digest}}, title = {{{Conventional and Machine Learning Approaches for Network and Service Coordination}}}, year = {{2021}}, } @inbook{36260, author = {{Weber, Jutta}}, booktitle = {{Drone Imaginaries. The Power of Remote Vision}}, editor = {{Maurer, Kathrin and Graae, Andreas Immanuel}}, pages = {{167--179}}, publisher = {{Manchester University Press}}, title = {{{Artificial Intelligence and the Sociotechnical Imaginary: On Skynet, Self-Healing Swarms and Slaughterbots}}}, year = {{2021}}, } @inbook{36257, author = {{Weber, Jutta and Mayer, Katja}}, booktitle = {{Explorations in Digital Cultures}}, editor = {{Burkhardt, Marcus and Shnayien, Mary and Grashöfer, Katja}}, publisher = {{meson press}}, title = {{{From Optimizing Military Operations to Targeting Terrorist Networks: Social Network Analysis in Data-Driven Warfare}}}, year = {{2021}}, } @inbook{36256, author = {{Weber, Jutta}}, booktitle = {{In digitaler Gesellschaft. Neukonfigurationen zwischen Robotern, Algorithmen und Usern}}, editor = {{Braun, Kathrin and Kropp, Cordula}}, pages = {{213--222}}, publisher = {{transcript}}, title = {{{Human-Machine Learning und Digital Commons}}}, year = {{2021}}, } @article{36545, abstract = {{Due to the Corona crisis, German Higher Education Institutions had to close their campuses in March and lecturers had to teach online. To understand how the Corona crisis affected students, first this article explains the structural and social inequalities in the German higher education system, using Tinto's (1975; 1997) student engagement theory. Second, the concept of Bergman-Rosamond et al. (2020) is used to analyze the challenges that Corona has raised for students, including current surveys. We found that the closure of the social space campus (and the Corona crisis as a whole) particularly hit hard those students who had previously been affected by (intersectional) inequality. Therefore, to lessen the specific challenges associated with the ad hoc transition to digital studying, the creation of a digital community of learning can help. We demonstrate how such a community can be created by the example seminar, "Digital practices: an autoethnographic observation". During the seminar, students recorded their digital technology use in a journal, and we analyzed the diary entries using the collaborate autoethnography method. The seminar example shows that this method is well suited for the development of a community of learning as it not only places students in the spotlight but as students work together on a topic they get to know each other, and a basis of trust is created through peer-feedback. Therefore, it was important to have a digital space (in this case Mahara) where the exchange could take place. The continuous insight into the students’ "learning status" enabled the lecturer to promote the learning and provide individual assistance for the students.}}, author = {{Steinhardt, Isabel}}, journal = {{ISA Pedagogy Series}}, keywords = {{Intersectionality, inequality, gender, diversity, higher-education, crisis}}, number = {{1}}, pages = {{42--59}}, publisher = {{International Sociology Association}}, title = {{{Students in the spotlight: Using collaborative autoethnography to build a community of learning in the Corona crisis}}}, volume = {{1}}, year = {{2021}}, } @techreport{36551, abstract = {{The call for free access to research data and materials is becoming louder and louder from the political and scientific communities in Germany. More and more researchers are facing demands to open up qualitative research data for scientific purposes. They often have a general interest in sharing their data, but are unsure how to proceed. This handout was developed to provide an initial introduction to opening and sharing qualitative data. It was developed at a workshop held in Berlin in January 2020, organized by the research group „Digitization of Science“ of the Weizenbaum Institute, together with its associate researcher Dr. Isabel Steinhardt from the University of Kassel. The workshop involved staff from German research data centers as well as mentees and mentors from the Fellow Program Open Science who already have experience with Open Science, qualitative research, and interdisciplinary research. The handout is addressed primarily to qualitatively researching scientists in Germany. For this reason, it was initially written in German. One year later, we have now decided to translate the handout into English as well. The reasons are twofold: first, we want to make it accessible to researchers in Germany with little knowledge of German. Second, we also want to give interested people outside Germany an insight into the German system and the German discussion about opening up and sharing qualitative data. Due to the objectives and the history of its development, the handout focuses on the German context. This includes the literature references and further sources, and the references to research data centers as well as legal issues. We have deliberately not included a contextualization of the German situation in international discussions in order to keep the handout as short as possible.}}, author = {{Steinhardt, Isabel and Fischer, Caroline and Heimstädt, Maximilian and Hirsbrunner, Simon David and Ikiz-Akinci, Dilek and Kressin, Lisa and Kretzer, Susanne and Möllenkamp, Andreas and Portzelt, Maike and Rahal, Rima-Maria and Schimmler, Sonja and Wilke, René and Wünsche, Hannes}}, pages = {{20}}, publisher = {{Weizenbaum Institute for the Networked Society - The German Internet Institu}}, title = {{{Opening up and Sharing Data from Qualitative Research: A Primer}}}, doi = {{10.34669/WI.WS/17}}, volume = {{17}}, year = {{2021}}, } @inbook{36557, abstract = {{Anhand einer explorativen Studie in den Fächern Jura und Soziale Arbeit wird rekonstruiert welche Praktiken Studierende in Bezug auf digitale Technologien haben und ob digitale Praktiken im Studium existieren. Dazu wurden narrative Interviews mit sechs Studierenden geführt, die habitushermeneutisch ausgewertet wurden. Die Ergebnisse zeigen keine digitalen Praktiken in Bezug auf das Studium, wohingegen sich digitale Praktiken im alltäglichen Leben zeigen. Für das Studium zeigen sich unterschiedliche Praktiken in der Nutzung digitaler Technologien, die in Beziehung zu den Kapitalsorten stehen, die Studierende besitzen. Die explorativen Ergebnisse legen nahe, dass Studierende unterschiedliche Hilfestellungen in Bezug auf die Digitalisierung des Studiums benötigen, die in der Lehrplanung und -pädagogik berücksichtigt werden müssten.}}, author = {{Steinhardt, Isabel}}, booktitle = {{Entwicklungen im Feld der Hochschule}}, editor = {{Bremer, Helmut and Lange-Vester, Andrea}}, isbn = {{978-3-7799-5861-1}}, pages = {{213--226}}, title = {{{Digitale Praktiken und das Studium}}}, year = {{2021}}, } @phdthesis{33872, author = {{Wembe Moafo, Boris Edgar}}, pages = {{180}}, title = {{{Geometric and Numerical Methods in Optimal Control and Zermelo Problems on Revolution Surfaces - Applications}}}, year = {{2021}}, } @article{25556, abstract = {{AbstractIn order to reduce fuel consumption and thus pollutant emissions, the automotive industry is increasingly developing lightweight construction concepts that are accompanied by an increasing usage of aluminum materials. Due to poor weldability of aluminum in combination with other materials, mechanical joining methods such as clinching were developed and established in series production. In order to predict the relevant characteristics of clinched joints and to ensure the reliability of the process, it is simulated numerically during product development processes. In this regard, the predictive accuracy of the simulated process highly depends on the implemented friction model. In particular, the frictional behavior between the sheet metals as well as between the sheet metal and clinching tools has a significant impact on the geometrical formation of the clinched joint. No testing methods exist that can sufficiently investigate the frictional behavior in sheet materials, especially under high interface pressures, different relative velocities, and long friction paths, while allowing a decoupled consideration of the test parameters. This paper describes the development of further testing concepts based on a proven tribo-torsion test method for determining friction coefficients between sheet metal materials for the simulation of clinching processes. For this purpose, the correlation of interface pressure and the relative velocity between aluminum and steel sheet material in clinching processes is investigated using numerical simulation. Based on these findings, the developed concepts focus on determining friction coefficients at interface pressures of the above materials, yield stress, as well as the reproduction of the occurring friction conditions between sheet metal materials and tool surfaces in clinching processes using tool substitutes. Furthermore, wear investigations between sheet metal material and tool surface were carried out in the friction tests with subsequent EDX analyses of the frictioned tool surfaces. The developed method also allows an optical deformation measurement of the sheet metal material specimen by means of digital image correlation (DIC). Based on a methodological approach, the test setups and the test systems used are explained, and the functionality of the concepts is proven by experimental tests using different sheet metal materials.}}, author = {{Böhnke, Max and Rossel, Moritz Sebastian and Bielak, Christian Roman and Bobbert, Mathias and Meschut, Gerson}}, issn = {{0268-3768}}, journal = {{The International Journal of Advanced Manufacturing Technology}}, title = {{{Concept development of a method for identifying friction coefficients for the numerical simulation of clinching processes}}}, doi = {{10.1007/s00170-021-07986-4}}, year = {{2021}}, } @misc{37504, author = {{Weber, Jutta}}, booktitle = {{Routledge Social Science Handbook of Artificial Intelligence}}, editor = {{Elliott, Anthony}}, pages = {{58--73 preprint}}, publisher = {{Routledge}}, title = {{{Artificial Intelligence in the Age of Technoscience}}}, year = {{2021}}, } @article{37644, abstract = {{Research on technological educationininterdisciplinary scienceand socialstudies (Sachunterricht) in German primary schools emphasizes that childrenare generally interested in technology. While several STEAM initiatives point towards a growing recognition of technological literacy, the consideration of technology education ininterdisciplinaryscience and social studies is quite underrepresented in practice as well as in research and teacher training.Takinginto accountthe UN-CRPDclaims foran inclusive educational system andthus alsothe right to equally participate in a free society,participation in society through participation in technological development is a fundamental common goal of technological and inclusive education and part of widely recognized technological literacy.It is therefore not well understood how teaching and learning arrangementscan consider and satisfythe needs of all different students. The research project the present paper is part of tries to unveil the appearance of student’s basic needs in relation to technological educationfor all children. Thisinitial quantitative part of a grounded theory study examined the subjective significance of basic psychological needs in interdisciplinary science studies in primary educationto allow for a well-reasoned sample choice for subsequent interviews. Quantitative results point towards some revisions regarding the instrument used and several implications on the diversity of students ́needs in science and social studies. Future research is needed with larger samples for factor-analysis.}}, author = {{Schröer, Franz and Tenberge, Claudia}}, issn = {{1893-1774}}, journal = {{TECHNE SERIES - Forskning i slöjdpedagogik och slöjdvetenskap}}, keywords = {{Inclusion, basic needs, Technology Education, Primary Education, autonomy, competence, social relatedness}}, location = {{Rauma (FIN)}}, number = {{2}}, pages = {{322--331}}, publisher = {{TECHNE SERIES}}, title = {{{Technological and Inclusive Education - Considering Students’ Needs Towards Technological Learning in Primary Schools}}}, volume = {{28}}, year = {{2021}}, } @inbook{34567, author = {{Alpsancar, Suzana}}, booktitle = {{Autonome Autos – Die Zukunft des Verkehrs und die Dispositive der Mobilität}}, editor = {{Sprenger, Florian}}, isbn = {{9783837650242}}, issn = {{2702-8852}}, pages = {{373 -- 397}}, publisher = {{transcript Verlag}}, title = {{{„Vom Fahr-Zeug zum Fahr-Ding. Ein Heideggerianischer Kommentar zum autonomen Automobil“}}}, doi = {{10.14361/9783839450246}}, year = {{2021}}, } @inproceedings{40541, author = {{Itner, D. and Gravenkamp, H. and Dreiling, Dmitrij and Feldmann, Nadine and Henning, Bernd}}, booktitle = {{14th WCCM-ECCOMAS Congress}}, publisher = {{CIMNE}}, title = {{{Simulation of Guided Waves in Cylinders Subject to Arbitrary Boundary Conditions Using the Scaled Boundary Finite Element Method}}}, doi = {{10.23967/wccm-eccomas.2020.307}}, volume = {{700}}, year = {{2021}}, } @article{41427, author = {{Uppenkamp, Vera and Höger, Christian}}, journal = {{Theo-Web. Zeitschrift für Religionspädagogik}}, number = {{2}}, pages = {{146--153}}, title = {{{"Wenn sich die Mitte auflöst...", ist das kein Verlust für die Religionspädagogik - ein bilanzierender Tagungsrückblick mit Augenzwinkern}}}, volume = {{20}}, year = {{2021}}, } @misc{41425, author = {{Uppenkamp, Vera}}, booktitle = {{Das wissenschaftlich-religionspädagogische Lexikon im Internet www.wirelex.de}}, title = {{{Art. Mädchen/Frauen}}}, year = {{2021}}, } @phdthesis{42070, author = {{Olma, Simon}}, isbn = {{9783947647231}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}}, title = {{{Systemtheorie von Hardware-in-the-Loop-Simulationen mit Anwendung auf einem Fahrzeugachsprüfstand mit parallelkinematischem Lastsimulator}}}, volume = {{404}}, year = {{2021}}, } @phdthesis{42069, author = {{Lankeit, Christopher}}, title = {{{Systematik zur Evolution technischer Anforderungen}}}, year = {{2021}}, } @book{42250, author = {{Eckel, Julia}}, isbn = {{ 978-3-8394-5320-9}}, pages = {{380}}, publisher = {{transcript}}, title = {{{ Das Audioviduum. Eine Theoriegeschichte des Menschenmotivs in audiovisuellen Medien}}}, year = {{2021}}, } @inbook{38153, author = {{Fuchs, Christian}}, booktitle = {{The Public Service Media and Public Service Internet Manifesto}}, editor = {{Fuchs, Christian and Unterberger, Klaus}}, pages = {{19--68}}, publisher = {{University of Westminster Press}}, title = {{{The Public Service Media and Public Service Internet Utopias Survey Report}}}, doi = {{https://doi.org/10.16997/book60.c}}, year = {{2021}}, } @article{38143, author = {{Fuchs, Christian}}, journal = {{Information, Communication and Society}}, number = {{15}}, pages = {{2258--2276}}, title = {{{History and Class Consciousness 2.0: Georg Lukács in the Age of Digital Capitalism and Big Data}}}, doi = {{https://doi.org/10.1080/1369118X.2020.1759670 }}, volume = {{24}}, year = {{2021}}, } @article{38146, author = {{Fuchs, Christian}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{1}}, pages = {{15--51}}, title = {{{Engels@200: Friedrich Engels and Digital Capitalism. How Relevant Are Engels’s Works 200 Years After His Birth?}}}, doi = {{https://doi.org/10.31269/triplec.v19i1.1228 }}, volume = {{19}}, year = {{2021}}, } @article{38145, author = {{Fuchs, Christian}}, journal = {{tripleC: Communication, Capitalism & Critique}}, number = {{1}}, pages = {{1--14}}, title = {{{Engels@200: Friedrich Engels in the Age of Digital Capitalism. Introduction}}}, doi = {{https://doi.org/10.31269/triplec.v19i1.1229}}, volume = {{19}}, year = {{2021}}, }