@article{21531, author = {{Gasteiger, Hedwig and Bruns, Julia and Benz, Christiane and Brunner, Esther and Sprenger, Priska}}, issn = {{1863-9690}}, journal = {{ZDM}}, pages = {{193--205}}, title = {{{Mathematical pedagogical content knowledge of early childhood teachers: a standardized situation-related measurement approach}}}, doi = {{10.1007/s11858-019-01103-2}}, volume = {{52}}, year = {{2019}}, } @article{46607, author = {{Schubert, Michael}}, journal = {{Journal of Borderlands Studies}}, pages = {{527 -- 545}}, title = {{{The Creation of Illegal Migration in the German Confederation, 1815–1866}}}, volume = {{34}}, year = {{2019}}, } @article{46733, author = {{Polzien, Andrea and Güldenpenning, Iris and Weigelt, Matthias}}, journal = {{German Journal of Exercise and Sport Research}}, number = {{4}}, pages = {{424–434}}, publisher = {{Springer Berlin}}, title = {{{Effector-specific priming effects during action observation in combat sports.}}}, volume = {{49}}, year = {{2019}}, } @article{46734, author = {{Güldenpenning, Iris and Weigelt, Matthias and Kunde, Wilfried}}, journal = {{Human Movement Science}}, pages = {{102499}}, publisher = {{Elsevier}}, title = {{{Processing head fakes in basketball: Are there ironic effects of instructions on the head-fake effect in basketball?}}}, doi = {{https://doi.org/10.1016/j.humov.2019.102499}}, volume = {{67}}, year = {{2019}}, } @article{42712, abstract = {{In der Sportwissenschaft existiert eine Vielzahl von motorischen Testinstrumenten, deren Konstruktionen unterschiedliche Zielstellungen verfolgen. Mit MOBAK-3-4 (Motorische Basiskompetenzen) etabliert sich ein kompetenzorientiertes Testverfahren für Dritt- und Viertklässler. In der vorliegenden Untersuchung mit N = 344 Kindern (167 Mädchen; M = 8,78 Jahre, SD = 0,40) sollen die faktorielle Validität des MOBAK-3-4 Testinstruments sowie Zusammenhänge mit dem Geschlecht, Alter und Gewichtsstatus (Body Mass Index, BMI), der Häufigkeit und Art von außerschulischer Sportaktivität sowie dem fähigkeitsorientierten Hagedorn-Parcours aufgeklärt werden. Die zweifaktorielle Struktur des MOBAK-3-4 konnte mit den Faktoren Sich-Bewegen und Etwas-Bewegen bestätigt werden (CFI = 0,97; RMSEA = 0,033). Zusammenhänge mit den motorischen Basiskompetenzen konnten durch die Integration der Kovariaten Geschlecht, Alter und BMI sowie Häufigkeit und Art von außerschulischer Sportaktivität in die konfirmatorische Faktorenanalyse nachgewiesen werden. Jungen zeigten gegenüber Mädchen im Umgang mit dem Ball (Etwas-Bewegen) bessere Leistungen. Mädchen waren hinsichtlich der Ganzkörperkoordination im Raum (Sich-Bewegen) leicht überlegen. Während die älteren Kinder im Etwas-Bewegen stärker als die jüngeren Kinder waren, zeigten sich im Sich-Bewegen keine altersspezifischen Leistungsunterschiede. Weiterhin stand die Häufigkeit Mannschaftssport in einem engen Zusammenhang mit Etwas-Bewegen sowie die Ausübung von Individualsportarten mit Sich-Bewegen. Zudem zeigten die Ergebnisse des Hagedorn-Parcours auf latenter Ebene mittlere bis starke Zusammenhänge mit den Kompetenzbereichen Sich-Bewegen (β = 0,75, p < 0,001) und Etwas-Bewegen (β = 0,66, p < 0,001).}}, author = {{Strotmeyer, Anne and Kehne, Miriam and Herrmann, Christian}}, issn = {{2509-3142}}, journal = {{German Journal of Exercise and Sport Research}}, number = {{1}}, pages = {{82--91}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Motorische Basiskompetenzen}}}, doi = {{10.1007/s12662-019-00596-z}}, volume = {{50}}, year = {{2019}}, } @inproceedings{47013, author = {{Polzien, A. and Güldenpenning, Iris and Weigelt, Matthias}}, booktitle = {{Abstractband der 51. Jahrestagung der Arbeitsgemeinschaft für Sportpsychologie (asp)}}, editor = {{Stoll, O.}}, location = {{Halle/Saale}}, pages = {{166}}, title = {{{Die Blicktäuschung im Basketball: Einfluss des zeitlichen Versatzes zwischen Blick- und Kopfwendung auf den Täuschungseffekt}}}, year = {{2019}}, } @inbook{47063, author = {{Güldenpenning, Iris and Weigelt, Matthias}}, booktitle = {{Dictionary of Sport Psychology}}, editor = {{Hackfort, D. and Schinke, R. J. and Strauss, B.}}, pages = {{69}}, publisher = {{Academic Press - Elsevier}}, title = {{{Deceptive Actions}}}, year = {{2019}}, } @inproceedings{15412, abstract = {{ Ultrasonic joining is a common industrial process. To build electrical connections in the electronics industry, uni-axial and torsional ultrasonic vibration have been used to join different types of workpieces for decades. Many influencing factors like ultrasonic power, bond normal force, bond duration and frequency are known to have a high impact on bond quality and reliability. Multi-dimensional bonding has been investigated in the past to increase ultrasonic power and consequently bond strength. This contribution is focused on the comparison of circular, multi-frequency planar and uniaxial vibration trajectories used for ultrasonic bonding of copper pins on copper substrate. Bond quality was analyzed by shear tests, scanning acoustic microscopy and interface cross-sections. }}, author = {{Schemmel, Reinhard and Eacock, Florian and Dymel, Collin and Hemsel, Tobias and Hunstig, Matthias and Brökelmann, Michael and Sextro, Walter}}, booktitle = {{International Symposium on Microelectronics}}, issn = {{2380-4505}}, location = {{Boston}}, pages = {{509--514}}, title = {{{Impact of multi-dimensional vibration trajectories on quality and failure modes in ultrasonic bonding}}}, doi = {{10.4071/2380-4505-2019.1.000509}}, year = {{2019}}, } @article{10334, abstract = {{Ultrasonic joining is a common industrial process. In the electronics industry it is used to form electrical connections, including those of dissimilar materials. Multiple influencing factors in ultrasonic joining are known and extensively investigated; process parameters like ultrasonic power, bond force, and bonding frequency of the ultrasonic vibration are known to have a high impact on a reliable joining process and need to be adapted for each new application with different geometry or materials. This contribution is focused on increasing ultrasonic power transmitted to the interface and keeping mechanical stresses during ultrasonic bonding low by using a multi-dimensional ultrasonic transducer concept. Bonding results for a new designed connector pin in IGBT-modules achieved by multi- and one-dimensional bonding are discussed.}}, author = {{Schemmel, Reinhard and Hemsel, Tobias and Dymel, Collin and Hunstig, Matthias and Brökelmann, Michael and Sextro, Walter}}, issn = {{0924-4247}}, journal = {{Sensors and Actuators A: Physical}}, keywords = {{Ultrasonic bonding, Ultrasonic welding, Multi-dimensional bonding, Complex vibration, Multi-frequent, Two-dimensional friction model}}, pages = {{653 -- 662}}, title = {{{Using complex multi-dimensional vibration trajectories in ultrasonic bonding and welding}}}, doi = {{10.1016/j.sna.2019.04.025}}, volume = {{295}}, year = {{2019}}, } @inproceedings{13460, abstract = {{Remaining useful lifetime (RUL) predictions as part of a condition monitoring system are focused in more and more research and industrial applications. To establish an efficient and precise estimate of the RUL of a technical product, different uncertainties have to be handled. To minimize the uncertainties of the RUL estimation, a reliable and accurate prognostic approach as well as a good failure threshold are important. Regarding the failure threshold, most often an expert sets a fixed failure threshold. However, neither the a priori known failure threshold nor a fixedthreshold value are feasible in every application. Especially in the case of varying characteristics of the monitored system, an adaptive failure threshold is of great importance concerning the accuracy of the RUL estimation. Rubber-metal-elements, which are used in a wide range of applications for vibration and sound isolation, are mon-itored by thermocouples to allow for lifetime predictions. Therefore, the element’s state is described by its temper-ature during its service life. Aiming to establish accurate RUL predictions of a rubber-metal-element, uncertainties due to nonlinear material characteristics and changing operational conditions have to be considered. Consequently, different temperature-based failure threshold definitions are implemented and compared within a particle filtering approach. }}, author = {{Bender, Amelie and Schinke, Lennart and Sextro, Walter}}, booktitle = {{Proceedings of the 29th European Safety and Reliability Conference (ESREL2019)}}, editor = {{Beer, Michael and Zio, Enrico}}, isbn = {{978-981-11-2724-3}}, keywords = {{RUL prediction, adaptive threshold, prognostics, condition monitoring}}, location = {{Hannover}}, number = {{29}}, pages = {{1262--1269}}, title = {{{Remaining useful lifetime prediction based on adaptive failure thresholds}}}, year = {{2019}}, } @article{21, abstract = {{We address the general mathematical problem of computing the inverse p-th root of a given matrix in an efficient way. A new method to construct iteration functions that allow calculating arbitrary p-th roots and their inverses of symmetric positive definite matrices is presented. We show that the order of convergence is at least quadratic and that adaptively adjusting a parameter q always leads to an even faster convergence. In this way, a better performance than with previously known iteration schemes is achieved. The efficiency of the iterative functions is demonstrated for various matrices with different densities, condition numbers and spectral radii.}}, author = {{Richters, Dorothee and Lass, Michael and Walther, Andrea and Plessl, Christian and Kühne, Thomas}}, journal = {{Communications in Computational Physics}}, number = {{2}}, pages = {{564--585}}, publisher = {{Global Science Press}}, title = {{{A General Algorithm to Calculate the Inverse Principal p-th Root of Symmetric Positive Definite Matrices}}}, doi = {{10.4208/cicp.OA-2018-0053}}, volume = {{25}}, year = {{2019}}, } @article{12871, author = {{Platzner, Marco and Plessl, Christian}}, issn = {{0170-6012}}, journal = {{Informatik Spektrum}}, title = {{{FPGAs im Rechenzentrum}}}, doi = {{10.1007/s00287-019-01187-w}}, year = {{2019}}, } @inproceedings{13461, abstract = {{As the emerging digitalization of technical systems offers immense opportunities to be exploited by means of bigdata analysis, ubiquitous computing and largely networked systems, the digital twin comes into focus to combineall these aspects to an attendant model of an individual system during design phase as well as during operation.Since state-of-art technical systems are growing increasingly complex due to inherent intelligence and increasingfunctionality, i. e. autonomous behavior so far, it becomes considerably challenging to ensure reliability for thosesystems. Many methods were developed to support a reliability focused design or reliability-by-design approachesto tackle this challenge during design process. In field, data-based methods, i. e. condition monitoring enabled bythe rise of machine learning approaches, are exploited to ensure a reliable operation based on the current conditionof the monitored system. In order to take advantage of existing models of system reliability during design phaseand condition monitoring systems during operation, a method is proposed to combine both approaches in order toset up a digital twin with focus on system reliability. The base model of the digital twin is taken from the systemreliability model from the design phase and is used during operation and therein updated to the current reliabilitybased on the state estimation of the condition monitoring system. The approach is illustrated with a case study of arolling bearing test rig.}}, author = {{Kaul, Thorben and Bender, Amelie and Sextro, Walter}}, booktitle = {{Proceedings of the 29th European Safety and Reliability Conference (ESREL2019)}}, editor = {{Beer, Michael and Zio, Enrico}}, isbn = {{ 978-981-11-2724-3}}, location = {{Hannover}}, number = {{29}}, pages = {{2340--2347}}, title = {{{Digital Twin for Reliability Analysis During Design and Operation of Mechatronic Systems}}}, year = {{2019}}, } @inproceedings{28445, author = {{Wehde, Janis and Schäfer, Laura and Schlegel, Anina and Oster, Leonie and Beeck, Valentina}}, location = {{Münster}}, title = {{{Orientierungs(un)willig? – Zu studienbereichsspezifischen Unterschieden in der Intention zur beruflichen Orientierung}}}, year = {{2019}}, } @inbook{59978, abstract = {{In latest body-in-white (BIW) concepts, engineers take into account a wider range of different materials to pursue a multi-material design approach. However, the lightweight potential of common materials like steel, aluminum or even fiber-reinforcement plastics (FRP) is limited. In keeping with the motto “the best material for the best application”, a new approach for a top-down material design is introduced. With the aim to develop an application tailored material, the multi-material concept is adapted for the thickness dimension of the component. Within this contribution a new optimization- based design methodology is applied on a stiffness relevant car body part. Starting with benchmark simulations of a reference BIW structure, a critical car body component is determined by an internal energy based method and a subsequent sensitivity analysis. The identified demonstrator component is later subdivided into multiple layers and submitted to a first optimization loop in which the developed methodology varies the material parameters for each single layer. Once an optimum for the through-thickness properties of the part is found, further optimization loops with concrete material pendants and manufacturing restrictions are carried out. The result is a hybrid laminate part consisting of steel and FRP plies. To achieve a further improvement in body characteristics and lightweight, the investigated part is redesigned by the aim of topology optimization. Finally, the tailored hybrid stacks are validated in BIW simulations and compared with the reference. The optimization-based approach allows a weight reduction up to 25 % while maintaining or even improving the BIW properties.}}, author = {{Camberg, Alan Adam and Stratmann, Ina and Tröster, Thomas}}, booktitle = {{Zukunftstechnologien für den multifunktionalen Leichtbau}}, isbn = {{9783662582053}}, issn = {{2524-4787}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{TAILORED STACKED HYBRIDS – AN OPTIMIZATION-BASED APPROACH IN MATERIAL DESIGN FOR FURTHER IMPROVEMENT IN LIGHTWEIGHT CAR BODY STRUCTURES}}}, doi = {{10.1007/978-3-662-58206-0_12}}, year = {{2019}}, } @inbook{59887, author = {{Plaksin, Anna Viktoria Katrin and Olley, Jacob}}, booktitle = {{Music Encoding Conference Proceedings 2015, 2016 and 2017}}, editor = {{Di Bacco, Giuliano and Kepper, Johannes and Roland, Perry D.}}, location = {{Tours}}, pages = {{119--130}}, title = {{{Creating an Encoding Workflow for a Critical Edition of Ottoman Music Manuscripts: Challenges and Solutions}}}, doi = {{10.15463/MUSIC-1}}, year = {{2019}}, } @article{59687, abstract = {{Lasers have both ubiquitous applications and roles as model systems in which non-equilibrium and cooperative phenomena can be elucidated1. The introduction of novel concepts in laser operation thus has potential to lead to both new applications and fundamental insights2. Spintronics3, in which both the spin and the charge of the electron are used, has led to the development of spin-lasers, in which charge-carrier spin and photon spin are exploited. Here we show experimentally that the coupling between carrier spin and light polarization in common semiconductor lasers can enable room-temperature modulation frequencies above 200 gigahertz, exceeding by nearly an order of magnitude the best conventional semiconductor lasers. Surprisingly, this ultrafast operation of the resultant spin-laser relies on a short carrier spin relaxation time and a large anisotropy of the refractive index, both of which are commonly viewed as detrimental in spintronics3 and conventional lasers4. Our results overcome the key speed limitations of conventional directly modulated lasers and offer a prospect for the next generation of low-energy ultrafast optical communication.}}, author = {{Lindemann, Markus and Xu, Gaofeng and Pusch, Tobias and Michalzik, Rainer and Hofmann, Martin R. and Žutić, Igor and Gerhardt, Nils Christopher}}, issn = {{0028-0836}}, journal = {{Nature}}, number = {{7751}}, pages = {{212--215}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Ultrafast spin-lasers}}}, doi = {{10.1038/s41586-019-1073-y}}, volume = {{568}}, year = {{2019}}, } @article{64756, author = {{Walter, Boris}}, issn = {{0019-3577}}, journal = {{Indagationes Mathematicae}}, keywords = {{58D05, 57S05, 22E65, 58D15, 58B10}}, number = {{4}}, pages = {{669–705}}, title = {{{Weighted diffeomorphism groups of Riemannian manifolds}}}, doi = {{10.1016/j.indag.2019.03.003}}, volume = {{30}}, year = {{2019}}, } @article{64630, author = {{Glöckner, Helge}}, issn = {{0008-414X}}, journal = {{Canadian Journal of Mathematics}}, keywords = {{22E65, 22A05, 22E67, 46A13, 46M40, 58D05}}, number = {{1}}, pages = {{131–152}}, title = {{{Completeness of infinite-dimensional Lie groups in their left uniformity}}}, doi = {{10.4153/CJM-2017-048-5}}, volume = {{71}}, year = {{2019}}, } @article{64780, abstract = {{The increasing trend of multi-material and space-frame design in automotive car body constructions consolidates the need for mechanical joining technologies with one-sided accessibility. The high-speed joining process (also called “RIVTAC®” or “Impact”) is an innovative and flexible technology. In this process, a tack having a profiled shank and an ogival shaped tip is pushed into the joining partners with a speed of 20 to 40 m/s without any pre-punching. The plastic and friction work is converted into heat, which causes an abrupt rise of temperature in the joining zone. This improves the flowability of the material which leads to filling the annular grooves existing on the shank of the tack. Simultaneously, a force-fit is created between the sheet metal and the tack. Furthermore, the effects of inertia are used so that the thin-walled structures can be joined without any additional tools (e.g. a die). The joining process causes the deformation of the structure, which must be taken into account with regard to tolerances. The numerical simulation is a powerful tool to predict the deformation and the joinability of a complex structure as well as the mechanical properties of the connection. The paper is about the detailed process- and load-simulation of high-speed joining as well as the required experimental data basis, such as temperature and strain rate dependent flow curves. Furthermore, the friction parameters are very important for the physical consideration of the force-fit connection. Coupled structural-thermal simulations of an axisymmetric 2D-model are performed using explicit and implicit codes.}}, author = {{Meschut, Gerson and Hein, David and Gerkens, Michael}}, issn = {{2351-9789}}, journal = {{Procedia Manufacturing}}, pages = {{280--287}}, publisher = {{Elsevier BV}}, title = {{{Numerical simulation of high-speed joining of sheet metal structures}}}, doi = {{10.1016/j.promfg.2019.02.173}}, volume = {{29}}, year = {{2019}}, }