@article{32810, author = {{Li, Jiaao and Ma, Yulai and Shi, Yongtang and Wang, Weifan and Wu, Yezhou}}, issn = {{0195-6698}}, journal = {{European Journal of Combinatorics}}, keywords = {{Discrete Mathematics and Combinatorics}}, publisher = {{Elsevier BV}}, title = {{{On 3-flow-critical graphs}}}, doi = {{10.1016/j.ejc.2021.103451}}, volume = {{100}}, 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}}, } @inproceedings{21198, author = {{Hanselle, Jonas Manuel and Tornede, Alexander and Wever, Marcel Dominik and Hüllermeier, Eyke}}, location = {{Delhi, India}}, title = {{{Algorithm Selection as Superset Learning: Constructing Algorithm Selectors from Imprecise Performance Data}}}, year = {{2021}}, } @inproceedings{21813, author = {{Hansmeier, Tim and Platzner, Marco}}, booktitle = {{GECCO '21: Proceedings of the Genetic and Evolutionary Computation Conference Companion}}, isbn = {{978-1-4503-8351-6}}, location = {{Lille, France}}, pages = {{1639–1647}}, publisher = {{Association for Computing Machinery (ACM)}}, title = {{{An Experimental Comparison of Explore/Exploit Strategies for the Learning Classifier System XCS}}}, doi = {{10.1145/3449726.3463159}}, year = {{2021}}, } @inproceedings{25265, abstract = {{Waveguide-based methods can be used for the non-destructive determination of acoustic material parameters. One of these methods is based on transmission measurements of cylindrical polymeric specimens. Here, the experimental setup consists of two transducers, which excite and receive the waveguide modes at the faces of the cylinder. The measurement, as well as a forward model, are used to determine material parameters of the polymeric specimen in an inverse approach. 1-3 piezoelectric composites are used as an active element because they can be approximated by a thickness vibration only. This allows an easy identification of Mason model parameters to characterise the transducers’ vibration behaviour. However, sensitivity analysis shows a high uncertainty in the determination of the mechanical shear parameters due to the uniform excitation. To increase the sensitivity to these shear motions, arbitrary excitations were investigated by means of numerical simulation. In order to be able to realise the determined optimal excitation, new transducer prototypes were designed. By subdividing the electrodes of the active element, for example, ring-shaped excitation is feasible. Furthermore, it can be shown that modelling these transducers with a one-dimensional Mason model is sufficient.}}, author = {{Dreiling, Dmitrij and Itner, Dominik and Feldmann, Nadine and Scheidemann, Claus and Gravenkamp, Hauke and Henning, Bernd}}, booktitle = {{Fortschritte der Akustik - DAGA 2021}}, location = {{Wien}}, publisher = {{Deutsche Gesellschaft für Akustik e.V. (DEGA)}}, title = {{{Application and modelling of ultrasonic transducers using 1-3 piezoelectric composites with structured electrodes}}}, 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}}, } @inproceedings{29938, abstract = {{Modular solid-state transformers (SSTs) are a promising technology in converting power from a 10kV three-phase medium voltage to a lower DC-voltage in the range of 100…400V to provide pure DC power to applications such as electrolyzers for hydrogen generation, data centers with a DC power distribution and DC micro grids. Modular SSTs which can be interpreted as modular multilevel converters with an isolated DC-DC output stage per module, are designed with redundant modules to increase reliability. Usually, each of the three arms operates independently, and therefore, only a fixed number of faulty modules can be compensated in each arm, even if all modules are operational in the remaining two arms. With the proposed zero-sequence voltage injection, up to 100% more faulty modules can be compensated in an arm by employing the same hardware. In addition, module power imbalances are nearly eliminated by utilizing a fundamental frequency zero-sequence voltage. A dominant 3rd harmonic zero-sequence voltage injection in combination with the 5th, 7th and several higher order harmonics with adaptive (small) amplitudes minimize the required arm voltages at steady-state. For nominal operation or symmetrical faults, the proposed technique is equivalent to the well known Min-Max voltage injection, which already reduces the peak arm voltage by 13.4% compared to a constant star point potential. A statistical analysis proves, that the expected number of tolerable faulty modules of the 1MW SST increases by 12% without the need for additional hardware.}}, author = {{Unruh, Roland and Lange, Jarren and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{23rd European Conference on Power Electronics and Applications (EPE'21 ECCE Europe)}}, isbn = {{978-9-0758-1537-5}}, keywords = {{Solid-State Transformer, Zero sequence voltage, Fault handling strategy, Power balance control technique, Three-phase system}}, location = {{Ghent, Belgium}}, publisher = {{IEEE}}, title = {{{Adaptive Zero-Sequence Voltage Injection for Modular Solid-State Transformer to Compensate for Asymmetrical Fault Conditions}}}, doi = {{https://doi.org/10.23919/EPE21ECCEEurope50061.2021.9570542}}, year = {{2021}}, } @article{33481, abstract = {{While 2D Gibbsian particle systems might exhibit orientational order resulting in a lattice-like structure, these particle systems do not exhibit positional order if the interaction between particles satisfies some weak assumptions. Here we investigate to which extent particles within a box of size may fluctuate from their ideal lattice position. We show that particles near the center of the box typically show a displacement at least of order . Thus we extend recent results on the hard disk model to particle systems with fairly arbitrary particle spins and interaction. Our result applies to models such as rather general continuum Potts type models, e.g. with Widom–Rowlinson or Lenard-Jones-type interaction.}}, author = {{Richthammer, Thomas and Fiedler, Michael}}, journal = {{Stochastic Processes and their Applications}}, pages = {{1--32}}, publisher = {{Elsevier}}, title = {{{A lower bound on the displacement of particles in 2D Gibbsian particle systems}}}, doi = {{https://doi.org/10.1016/j.spa.2020.10.003}}, volume = {{132}}, year = {{2021}}, } @unpublished{27778, abstract = {{Consider a set of jobs connected to a directed acyclic task graph with a fixed source and sink. The edges of this graph model precedence constraints and the jobs have to be scheduled with respect to those. We introduce the Server Cloud Scheduling problem, in which the jobs have to be processed either on a single local machine or on one of many cloud machines. Both the source and the sink have to be scheduled on the local machine. For each job, processing times both on the server and in the cloud are given. Furthermore, for each edge in the task graph, a communication delay is included in the input and has to be taken into account if one of the two jobs is scheduled on the server, the other in the cloud. The server can process jobs sequentially, whereas the cloud can serve as many as needed in parallel, but induces costs. We consider both makespan and cost minimization. The main results are an FPTAS with respect for the makespan objective for a fairly general case and strong hardness for the case with unit processing times and delays.}}, author = {{Maack, Marten and Meyer auf der Heide, Friedhelm and Pukrop, Simon}}, booktitle = {{arXiv:2108.02109}}, title = {{{Full Version -- Server Cloud Scheduling}}}, year = {{2021}}, } @misc{27058, author = {{Wiecher, Carsten and Fischbach, Jannik and Greenyer, Joel and Vogelsang, Andreas and Wolff, Carsten and Dumitrescu, Roman}}, booktitle = {{arXiv preprint}}, title = {{{Integrated and Iterative Requirements Analysis and Test Specification: A Case Study at Kostal}}}, 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}}, } @inproceedings{26407, author = {{Piskachev, Goran and Krishnamurthy, Ranjith and Bodden, Eric}}, booktitle = {{2021 IEEE 21st International Working Conference on Source Code Analysis and Manipulation (SCAM)}}, title = {{{SecuCheck: Engineering configurable taint analysis for software developers}}}, year = {{2021}}, } @inproceedings{22463, author = {{Luo, Linghui and Schäf, Martin and Sanchez, Daniel and Bodden, Eric}}, booktitle = {{Proceedings of the 29th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering}}, title = {{{IDE Support for Cloud-Based Static Analyses}}}, year = {{2021}}, } @inproceedings{33840, author = {{Karakaya, Kadiray and Bodden, Eric}}, booktitle = {{2021 IEEE 21st International Working Conference on Source Code Analysis and Manipulation (SCAM)}}, pages = {{181–186}}, title = {{{SootFX: A Static Code Feature Extraction Tool for Java and Android}}}, 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{35575, author = {{Schulze Darup, Moritz and Alexandru, Andreea B. and Quevedo, Daniel E. and Pappas, George J.}}, issn = {{1066-033X}}, journal = {{IEEE Control Systems}}, keywords = {{Electrical and Electronic Engineering, Modeling and Simulation, Control and Systems Engineering, Electrical and Electronic Engineering, Modeling and Simulation, Control and Systems Engineering}}, number = {{3}}, pages = {{58--78}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Encrypted Control for Networked Systems: An Illustrative Introduction and Current Challenges}}}, doi = {{10.1109/mcs.2021.3062956}}, volume = {{41}}, year = {{2021}}, } @article{35576, author = {{Schulze Darup, Moritz and Klädtke, Manuel and Mönnigmann, Martin}}, issn = {{2405-8963}}, journal = {{IFAC-PapersOnLine}}, keywords = {{Control and Systems Engineering}}, number = {{6}}, pages = {{290--295}}, publisher = {{Elsevier BV}}, title = {{{Exact solution to a special class of nonlinear MPC problems}}}, doi = {{10.1016/j.ifacol.2021.08.559}}, volume = {{54}}, year = {{2021}}, }