@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}}, } @article{23891, abstract = {{Within a pre-post-design, we scrutinized the effects of normative augmented feedback with positive and negative valence on learning motor accuracy, consistency as well as automaticity by means of a dual-task paradigm. Forty-two healthy physical education students were instructed to produce an arm-movement sequence as precisely as possible with regard to three spatial reversal points within a time limit of 1200 ms. Twenty-eight practiced an elbow-extension-flexion-sequence (690 trials) and 14 participants were tested as a control group without feedback practice. Valence of normative feedback was systematically manipulated by means of reference lines in a visual feedback display. The reference lines indicated performance of a putative peer-group either to be superior (negative valence, Normative-Negative-Group) or inferior (positive valence, Normative-Positive-Group) to participants’ actual performance. As a result, dual-task costs (n-back error) significantly decreased solely in the Normative-Positive-Group, p = .003, η2p = .51, but in no other group. Surprisingly, the mean absolute error for the motor task significantly decreased (i.e., precision increased) only in the Normative-Negative-Group with a large effect size, but in none of the other groups. Motor consistency was not significantly affected by the valence of normative feedback. According to the hypotheses of error-provoked attentional control, positive feedback-valence appears to enhance skill automatization, while – unexpectedly – only negative feedback-valence seems to enhance movement precision, which may be explained by effects of feedback valence on the learners aspiration level.}}, author = {{Zobe, Christina and Krause, Daniel and Blischke, Klaus}}, journal = {{Human Movement Science}}, keywords = {{Augmented feedback Automaticity Dual task Motor learning}}, pages = {{529--540}}, publisher = {{Elsevier}}, title = {{{Dissociative effects of normative feedback on motor automaticity and motor accuracy in learning an arm movement sequence}}}, doi = {{https://doi.org/10.1016/j.humov.2019.06.004}}, volume = {{66}}, year = {{2019}}, } @article{48703, author = {{Zobe, Christina and Krause, Daniel and Blischke, Klaus}}, issn = {{0167-9457}}, journal = {{Human Movement Science}}, keywords = {{Experimental and Cognitive Psychology, Orthopedics and Sports Medicine, General Medicine, Biophysics}}, pages = {{529--540}}, publisher = {{Elsevier BV}}, title = {{{Dissociative effects of normative feedback on motor automaticity and motor accuracy in learning an arm movement sequence}}}, doi = {{10.1016/j.humov.2019.06.004}}, volume = {{66}}, year = {{2019}}, } @unpublished{16711, abstract = {{Embedding techniques allow the approximations of finite dimensional attractors and manifolds of infinite dimensional dynamical systems via subdivision and continuation methods. These approximations give a topological one-to-one image of the original set. In order to additionally reveal their geometry we use diffusion mapst o find intrinsic coordinates. We illustrate our results on the unstable manifold of the one-dimensional Kuramoto--Sivashinsky equation, as well as for the attractor of the Mackey-Glass delay differential equation.}}, author = {{Gerlach, Raphael and Koltai, Péter and Dellnitz, Michael}}, booktitle = {{arXiv:1902.08824}}, title = {{{Revealing the intrinsic geometry of finite dimensional invariant sets of infinite dimensional dynamical 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}}, } @article{56248, author = {{Engel, Joachim and Biehler, Rolf and Frischemeier, Daniel and Podworny, Susanne and Schiller, Achim and Martignon, Laura}}, issn = {{1863-8155}}, journal = {{AStA Wirtschafts- und Sozialstatistisches Archiv}}, number = {{1}}, pages = {{113--114}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Erratum to: Zivilstatistik: Konzept einer neuen Perspektive auf Data Literacy und Statistical Literacy}}}, doi = {{10.1007/s11943-019-00266-4}}, volume = {{14}}, year = {{2019}}, } @inbook{56245, author = {{Biehler, Rolf}}, booktitle = {{ICME-13 Monographs}}, editor = {{Jahnke, H. N. and Hefendehl-Hebeker, L.}}, isbn = {{9783030110680}}, issn = {{2520-8322}}, publisher = {{Springer International Publishing}}, title = {{{Allgemeinbildung, Mathematical Literacy, and Competence Orientation}}}, doi = {{10.1007/978-3-030-11069-7_6}}, year = {{2019}}, } @inbook{56247, author = {{Biehler, Rolf}}, booktitle = {{Proceedings of the Third International Virtual Congress of Statistical Education}}, editor = {{Contreras, J. M. and Gea, M. M. and Lopez-Martin, M. M. and Molina-Portillo, E.}}, publisher = {{Universidad de Granada}}, title = {{{Software for learning and for doing statistics and probability–Looking back and looking forward from a personal perspective}}}, year = {{2019}}, } @article{56252, author = {{Frischemeier, Daniel and Podworny, Susanne and Biehler, Rolf}}, journal = {{Stochastik in der Schule}}, number = {{1}}, pages = {{26--33}}, title = {{{Chancen und Herausforderungen für die Implementation von Zivilstatistiken in der Lehramtsausbildung}}}, volume = {{39}}, year = {{2019}}, } @inbook{56259, author = {{Nieszporek, Ralf and Biehler, Rolf}}, booktitle = {{Proceedings of the Eleventh Congress of the European Society for Research in Mathematics Education}}, editor = {{Jankvist, U. T. and van den Heuvel-Panhuizen, M. and Veldhuis, M.}}, publisher = {{Freudenthal Group & Freudenthal Institute, Utrecht University and ERME}}, title = {{{Retrospective competence assessment in a PD course on teaching statistics with digital tools in upper secondary schools}}}, year = {{2019}}, } @inbook{56257, author = {{Mai, Tobias and Biehler, Rolf}}, booktitle = {{Proceedings of the Third International Conference on Mathametics Textbook research and Development}}, editor = {{Rezat, S. and Lianghuo, F. and Hattermann, M. and Schumacher, J. and Wuschke, H.}}, pages = {{233--238}}, publisher = {{Universitätsbibliothek Paderborn}}, title = {{{On the Introduction of Vectors in German Textbooks for Upper Secondary School}}}, volume = {{16}}, year = {{2019}}, } @article{56255, author = {{Kempen, Leander and Biehler, Rolf}}, issn = {{1863-9690}}, journal = {{ZDM}}, number = {{5}}, pages = {{731--746}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Fostering first-year pre-service teachers’ proof competencies}}}, doi = {{10.1007/s11858-019-01035-x}}, volume = {{51}}, year = {{2019}}, } @inbook{56256, author = {{Lankeit, Elisa and Biehler, Rolf}}, booktitle = {{Hanse-Kolloquium zur Hochschuldidaktik der Mathematik 2018}}, editor = {{Klinger, M. and Schüler-Meyer, A. and Wessel, L.}}, pages = {{117--131}}, publisher = {{WTM-Verlag}}, title = {{{Vorstellung einer Aufgabe zu den Zusammenhängen verschiedener Differenzierbarkeitsbegriffe im Mehrdimensionalen}}}, year = {{2019}}, } @inbook{56188, author = {{Fäßler, Peter and Staffel, Florian}}, booktitle = {{Briten in Westfalen : Besatzer, Verbündete, Freunde?}}, editor = {{Fäßler, Peter and Neuwöhner, Andreas and Staffel , Florian }}, isbn = {{978-3-657-79250-4}}, pages = {{1--5}}, publisher = {{Ferdinand Schöningh}}, title = {{{Einleitung }}}, year = {{2019}}, } @techreport{56297, author = {{Baumgarten, Daniel and Lehwald, Sybille}}, issn = {{2364-1428}}, title = {{{Trade exposure and the decline in collective bargaining: Evidence from Germany}}}, year = {{2019}}, }