@article{21796, author = {{Schuster, J and Kim, T Y and Batke, E and Reuter, Dirk and Wieck, A D}}, issn = {{0268-1242}}, journal = {{Semiconductor Science and Technology}}, title = {{{Two-dimensional electron bound hole photoluminescence in GaAs in perpendicular magnetic fields}}}, doi = {{10.1088/1361-6641/ab89e1}}, year = {{2020}}, } @article{16457, author = {{Lehmann, T and Büchel, D and Cockcroft, J and Louw, Q and Baumeister, Jochen}}, issn = {{0306-4522}}, journal = {{Neuroscience}}, pages = {{63--72}}, title = {{{Modulations of Inter-Hemispherical Phase Coupling in Human Single Leg Stance.}}}, doi = {{10.1016/j.neuroscience.2020.01.029}}, volume = {{430}}, year = {{2020}}, } @inproceedings{16487, author = {{Bobolz, Jan and Eidens, Fabian and Krenn, Stephan and Slamanig, Daniel and Striecks, Christoph}}, booktitle = {{Proceedings of the 15th ACM Asia Conference on Computer and Communications Security (ASIA CCS ’20),}}, location = {{Taiwan}}, publisher = {{ACM}}, title = {{{Privacy-Preserving Incentive Systems with Highly Efficient Point-Collection}}}, doi = {{10.1145/3320269.3384769}}, year = {{2020}}, } @inbook{16508, author = {{Harteis, Christian and Caruso, Carina}}, booktitle = {{Verlängerte Praxisphasen in der universitären Lehrerbildung: Spannungsfelder zwischen Theorie, Praxis und der Bestimmung von Professionalisierung }}, editor = {{Rheinländer, K. and Scholl, D.}}, pages = {{58--73}}, publisher = {{Klinkhardt}}, title = {{{Inwiefern können Praxisphasen im Studium zu einer Theorie-Praxis-Relationierung beitragen? Implikationen für die professionelle Entwicklung angehender Lehrkräfte. }}}, year = {{2020}}, } @inproceedings{16903, abstract = {{We consider the clock synchronization problem in the (discrete) beeping model: Given a network of $n$ nodes with each node having a clock value $\delta(v) \in \{0,\ldots T-1\}$, the goal is to synchronize the clock values of all nodes such that they have the same value in any round. As is standard in clock synchronization, we assume \emph{arbitrary activations} for all nodes, i.e., the nodes start their protocol at an arbitrary round (not limited to $\{0,\ldots,T-1\}$). We give an asymptotically optimal algorithm that runs in $4D + \Bigl\lfloor \frac{D}{\lfloor T/4 \rfloor} \Bigr \rfloor \cdot (T \mod 4) = O(D)$ rounds, where $D$ is the diameter of the network. Once all nodes are in sync, they beep at the same round every $T$ rounds. The algorithm drastically improves on the $O(T D)$-bound of \cite{firefly_sync} (where $T$ is required to be at least $4n$, so the bound is no better than $O(nD)$). Our algorithm is very simple as nodes only have to maintain $3$ bits in addition to the $\lceil \log T \rceil$ bits needed to maintain the clock. Furthermore we investigate the complexity of \emph{self-stabilizing} solutions for the clock synchronization problem: We first show lower bounds of $\Omega(\max\{T,n\})$ rounds on the runtime and $\Omega(\log(\max\{T,n\}))$ bits of memory required for any such protocol. Afterwards we present a protocol that runs in $O(\max\{T,n\})$ rounds using at most $O(\log(\max\{T,n\}))$ bits at each node, which is asymptotically optimal with regards to both, runtime and memory requirements.}}, author = {{Feldmann, Michael and Khazraei, Ardalan and Scheideler, Christian}}, booktitle = {{Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, publisher = {{ACM}}, title = {{{Time- and Space-Optimal Discrete Clock Synchronization in the Beeping Model}}}, doi = {{10.1145/3350755.3400246}}, year = {{2020}}, } @inproceedings{16968, abstract = {{In this work, we initiate the research about the Gathering problem for robots with limited viewing range in the three-dimensional Euclidean space. In the Gathering problem, a set of initially scattered robots is required to gather at the same position. The robots' capabilities are very restricted -- they do not agree on any coordinate system or compass, have a limited viewing range, have no memory of the past and cannot communicate. We study the problem in two different time models, in FSYNC (fully synchronized discrete rounds) and the continuous time model. For FSYNC, we introduce the 3D-Go-To-The-Center-strategy and prove a runtime of $\Theta(n^2)$ that matches the currently best runtime bound for the same model in the Euclidean plane [SPAA'11]. Our main result is the generalization of contracting strategies (continuous time) from [Algosensors'17] to three dimensions. In contracting strategies, every robot that is located on the global convex hull of all robots' positions moves with full speed towards the inside of the convex hull. We prove a runtime bound of $O(\Delta \cdot n^{3/2})$ for any three-dimensional contracting strategy, where $\Delta$ denotes the diameter of the initial configuration. This comes up to a factor of $\sqrt{n}$ close to the lower bound of $\Omega (\Delta \cdot n)$ which is already true in two dimensions. In general, it might be hard for robots with limited viewing range to decide whether they are located on the global convex hull and which movement maintains the connectivity of the swarm, rendering the design of concrete contracting strategies a challenging task. We prove that the continuous variant of 3D-Go-To-The-Center is contracting and keeps the swarm connected. Moreover, we give a simple design criterion for three-dimensional contracting strategies that maintains the connectivity of the swarm and introduce an exemplary strategy based on this criterion.}}, author = {{Braun, Michael and Castenow, Jannik and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 27th Conference on Structural Information and Communication Complexity (SIROCCO)}}, location = {{Paderborn}}, publisher = {{Springer}}, title = {{{Local Gathering of Mobile Robots in Three Dimensions}}}, doi = {{10.1007/978-3-030-54921-3_4}}, year = {{2020}}, } @inproceedings{17063, author = {{Hansmeier, Tim and Kaufmann, Paul and Platzner, Marco}}, booktitle = {{GECCO '20: Proceedings of the Genetic and Evolutionary Computation Conference Companion}}, isbn = {{978-1-4503-7127-8}}, location = {{Cancún, Mexico}}, pages = {{1756--1764}}, publisher = {{Association for Computing Machinery (ACM)}}, title = {{{An Adaption Mechanism for the Error Threshold of XCSF}}}, doi = {{10.1145/3377929.3398106}}, year = {{2020}}, } @inproceedings{15604, author = {{Jovanovikj, Ivan and Yigitbas, Enes and Sauer, Stefan and Engels, Gregor}}, booktitle = {{Proceedings of the 8th International Conference on Model-Driven Engineering and Software Development - Volume 1: MODELSWARD}}, isbn = {{978-989-758-400-8}}, location = {{Valletta}}, title = {{{Concept-based Co-Migration of Test Cases}}}, doi = {{10.5220/0009171404490456}}, year = {{2020}}, } @article{15605, author = {{Jovanovikj, Ivan and Yigitbas, Enes and Sauer, Stefan and Engels, Gregor}}, issn = {{1613-0073}}, journal = {{Software Engineering 2020 Workshopband}}, location = {{Innscbruck}}, title = {{{Test Case Co-Migration Method Patterns}}}, year = {{2020}}, } @article{15628, abstract = {{The three-dimensional (3D) crystal structures of the GAF3 domain of cyanobacteriochrome Slr1393 (Synechocystis PCC6803) carrying a phycocyanobilin chromophore could be solved in both 15-Z dark-adapted state, Pr, λmax = 649 nm, and 15-E photoproduct, Pg, λmax = 536 nm (resolution, 1.6 and 1.86 Å, respectively). The structural data allowed identifying the large spectral shift of the Pr-to-Pg conversion as resulting from an out-of-plane rotation of the chromophore’s peripheral rings and an outward movement of a short helix formed from a formerly unstructured loop. In addition, a third structure (2.1-Å resolution) starting from the photoproduct crystals allowed identification of elements that regulate the absorption maxima. In this peculiar form, generated during X-ray exposition, protein and chromophore conformation still resemble the photoproduct state, except for the D-ring already in 15-Z configuration and tilted out of plane akin the dark state. Due to its formation from the photoproduct, it might be considered an early conformational change initiating the parental state-recovering photocycle. The high quality and the distinct features of the three forms allowed for applying quantum-chemical calculations in the framework of multiscale modeling to rationalize the absorption maxima changes. A systematic analysis of the PCB chromophore in the presence and absence of the protein environment showed that the direct electrostatic effect is negligible on the spectral tuning. However, the protein forces the outer pyrrole rings of the chromophore to deviate from coplanarity, which is identified as the dominating factor for the color regulation.}}, author = {{Xu, Xiuling and Port, Astrid and Wiebeler, Christian and Zhao, Kai-Hong and Schapiro, Igor and Gärtner, Wolfgang}}, issn = {{0027-8424}}, journal = {{Proceedings of the National Academy of Sciences}}, title = {{{Structural Elements Regulating the Photochromicity in a Cyanobacteriochrome}}}, doi = {{10.1073/pnas.1910208117}}, year = {{2020}}, } @article{15714, author = {{Riedl, T. and Kunnathully, V. S. and Trapp, A. and Langer, T. and Reuter, D. and Lindner, J. K. N.}}, issn = {{2475-9953}}, journal = {{Physical Review Materials}}, title = {{{Strain-driven InAs island growth on top of GaAs(111) nanopillars}}}, doi = {{10.1103/physrevmaterials.4.014602}}, year = {{2020}}, } @inproceedings{16222, author = {{Zafeiropoulos, A. and Fotopoulou, E. and Peuster, Manuel and Schneider, Stefan Balthasar and Gouvas, P. and Behnke, D. and Müller, M. and Bök, P. and Trakadas, P. and Karkazis, P. and Karl, Holger}}, booktitle = {{IEEE Conference on Network Softwarization (NetSoft)}}, title = {{{Benchmarking and Profiling 5G Verticals' Applications: An Industrial IoT Use Case}}}, year = {{2020}}, } @article{16288, abstract = {{We derive a data-driven method for the approximation of the Koopman generator called gEDMD, which can be regarded as a straightforward extension of EDMD (extended dynamic mode decomposition). This approach is applicable to deterministic and stochastic dynamical systems. It can be used for computing eigenvalues, eigenfunctions, and modes of the generator and for system identification. In addition to learning the governing equations of deterministic systems, which then reduces to SINDy (sparse identification of nonlinear dynamics), it is possible to identify the drift and diffusion terms of stochastic differential equations from data. Moreover, we apply gEDMD to derive coarse-grained models of high-dimensional systems, and also to determine efficient model predictive control strategies. We highlight relationships with other methods and demonstrate the efficacy of the proposed methods using several guiding examples and prototypical molecular dynamics problems.}}, author = {{Klus, Stefan and Nüske, Feliks and Peitz, Sebastian and Niemann, Jan-Hendrik and Clementi, Cecilia and Schütte, Christof}}, issn = {{0167-2789}}, journal = {{Physica D: Nonlinear Phenomena}}, title = {{{Data-driven approximation of the Koopman generator: Model reduction, system identification, and control}}}, doi = {{10.1016/j.physd.2020.132416}}, volume = {{406}}, year = {{2020}}, } @inproceedings{16363, author = {{Hansmeier, Tim and Kaufmann, Paul and Platzner, Marco}}, booktitle = {{GECCO '20: Proceedings of the Genetic and Evolutionary Computation Conference Companion}}, isbn = {{978-1-4503-7127-8}}, location = {{Cancún, Mexico}}, pages = {{125--126}}, publisher = {{Association for Computing Machinery (ACM)}}, title = {{{Enabling XCSF to Cope with Dynamic Environments via an Adaptive Error Threshold}}}, doi = {{10.1145/3377929.3389968}}, year = {{2020}}, } @article{24563, abstract = {{AbstractLaser surface treatment of metals is one option to improve their properties for adhesive bonding. In this paper, a pulsed YVO4 Laser source with a wavelength of 1064 nm and a maximum power of 25 W was utilized to increase the surface area of the steel HCT490X in order to improve its bonding properties with a carbon fibre reinforced polymer (CFRP). Investigated was the influence of the scanning speed of the laser source on the bonding properties. For this purpose, the steel surfaces were ablated at a scanning speed between 1500 and 4500 mm/s. Afterwards the components were bonded with the adhesive HexBond™ 677. After lap shear tests were carried out on the specimen, the surfaces were inspected using scanning electron microscopy (SEM). The experiments revealed that the bonding quality can be improved with a high scanning speed, even when the surface is not completely ablated.}}, author = {{Voswinkel, D. and Kloidt, D. and Grydin, O. and Schaper, M.}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, pages = {{263--270}}, title = {{{Time efficient laser modification of steel surfaces for advanced bonding in hybrid materials}}}, doi = {{10.1007/s11740-020-01006-2}}, year = {{2020}}, } @inproceedings{19422, author = {{Sprenger, Alexander and Sadeghi-Kohan, Somayeh and Reimer, Jan Dennis and Hellebrand, Sybille}}, booktitle = {{IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFT’20), October 2020}}, title = {{{Variation-Aware Test for Logic Interconnects using Neural Networks - A Case Study}}}, year = {{2020}}, } @inproceedings{29939, abstract = {{In this paper, a full-bridge modular multilevel converter (MMC) and two half-bridge-based MMCs are evaluated for high-current low-voltage e.g. 100 - 400V DC-applications such as electrolysis, arc welding or datacenters with DC-power distribution. Usually, modular multilevel converters are used in high-voltage DC-applications (HVDC) in the multiple kV-range, but to meet the needs of a high-current demand at low output voltage levels, the modular converter concept requires adaptations. In the proposed concept, the MMC is used to step-down the three-phase medium-voltage of 10kV, and provide up to 1 MW to the load. Therefore, each module is extended by an LLC resonant converter to adapt to the specific electrolyzers DC-voltage range of 142 - 220V and to provide galvanic isolation. The six-arm MMC converter with half-bridge modules can be simplified and optimized by removing three arms, and thus halving the number of modules. In addition, the module voltage ripple and capacitor losses are decreased by 22% and 30% respectively. By rearranging the components of the half-bridge MMC to build a MMC consisting of grid-side full-bridge modules, the voltage ripple is further reduced by 78% and capacitor losses by 64%, while ensuring identical costs and volume for all MMCs. Finally, the LLC resonant converter is designed for the most efficient full-bridge MMC. The LLC can not operate at resonance with a fixed nominal module voltage of 770V because the output voltage is varying between 142 - 220V. By decreasing the module voltage down to 600V, additional points of operation can be operated in resonance, and the remaining are closer to resonance. The option to decrease the module voltage down to 600V, increases the number of required modules per arm from 12 to 15, which requires to balance the losses of the LLCs and the grid-side stages.}}, author = {{Unruh, Roland and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)}}, keywords = {{Multilevel converters, Resonant converter, High voltage power converters, ZVS Converters, Combination MMC LLC}}, location = {{Lyon, France}}, publisher = {{IEEE}}, title = {{{Evaluation of MMCs for High-Power Low-Voltage DC-Applications in Combination with the Module LLC-Design}}}, doi = {{10.23919/epe20ecceeurope43536.2020.9215687}}, year = {{2020}}, } @inproceedings{29894, author = {{Rehlaender, Philipp and Tikhonov, Sergey and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{2020 22nd European Conference on Power Electronics and Applications (EPE'20 ECCE Europe)}}, publisher = {{IEEE}}, title = {{{Dual Interleaved 3.6 kW LLC Converter Operating in Half-Bridge, Full-Bridge and Phase-Shift Mode as a Single-Stage Architecture of an Automotive On-Board DC-DC Converter}}}, doi = {{10.23919/epe20ecceeurope43536.2020.9215736}}, year = {{2020}}, } @inproceedings{30339, author = {{Ahmmad, Mohsin Ejaz and Schafmeister, Frank and Böcker, Joachim}}, booktitle = {{Proc. IEEE International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management (PCIM digital days)}}, location = {{Nuremberg, Germany}}, publisher = {{IEEE}}, title = {{{Practical Implementation and Verification of Simple-to-Implement Digital Current Observer for Half-Bridge Topologies}}}, year = {{2020}}, } @misc{15419, author = {{Sadeghi-Kohan, Somayeh and Hellebrand, Sybille}}, keywords = {{WORKSHOP}}, pages = {{4}}, publisher = {{32. Workshop "Testmethoden und Zuverlässigkeit von Schaltungen und Systemen" (TuZ'20), 16. - 18. Februar 2020}}, title = {{{Dynamic Multi-Frequency Test Method for Hidden Interconnect Defects}}}, year = {{2020}}, }