@article{50299,
abstract = {{A finite classical polar space of rank $n$ consists of the totally isotropic
subspaces of a finite vector space over $\mathbb{F}_q$ equipped with a
nondegenerate form such that $n$ is the maximal dimension of such a subspace. A
$t$-$(n,k,\lambda)$ design in a finite classical polar space of rank $n$ is a
collection $Y$ of totally isotropic $k$-spaces such that each totally isotropic
$t$-space is contained in exactly $\lambda$ members of $Y$. Nontrivial examples
are currently only known for $t\leq 2$. We show that $t$-$(n,k,\lambda)$
designs in polar spaces exist for all $t$ and $q$ provided that
$k>\frac{21}{2}t$ and $n$ is sufficiently large enough. The proof is based on a
probabilistic method by Kuperberg, Lovett, and Peled, and it is thus
nonconstructive.}},
author = {{Weiß, Charlene}},
journal = {{Des. Codes Cryptogr.}},
pages = {{971 -- 981}},
title = {{{Nontrivial $t$-designs in polar spaces exist for all $t$}}},
doi = {{10.1007/s10623-024-01471-1}},
volume = {{93}},
year = {{2025}},
}
@article{64292,
author = {{Lindemann, M. and D’Alessandro, M. and Ledentsov, N. and Makarov, O. Y. and Ledentsov, N. N. and Tibaldi, A. and Gerhardt, N. C. and Hofmann, M. R.}},
issn = {{1089-7550}},
journal = {{Journal of Applied Physics}},
number = {{5}},
publisher = {{AIP Publishing}},
title = {{{Laterally coupled vertical-cavity surface-emitting lasers with tunable resonance width and frequency}}},
doi = {{10.1063/5.0275622}},
volume = {{138}},
year = {{2025}},
}
@inproceedings{61918,
author = {{Rook, Jeroen and Renau, Quentin and Trautmann, Heike and Hart, Emma}},
booktitle = {{Proceedings of the 18th ACM/SIGEVO Conference on Foundations of Genetic Algorithms, FOGA 2025, Leiden, The Netherlands, August 27-29, 2025}},
pages = {{262–272}},
publisher = {{ACM}},
title = {{{Efficient Online Automated Algorithm Selection in the Face of Data-Drift in Optimisation Problem Instances}}},
doi = {{10.1145/3729878.3746615}},
year = {{2025}},
}
@inproceedings{64658,
author = {{Neukötter, Moritz and Jesinghausen, Steffen and Schmid, Hans-Joachim}},
location = {{Hamburg}},
title = {{{Die Möglichkeiten der Filament Extension Atomization }}},
year = {{2025}},
}
@inproceedings{64659,
author = {{Neukötter, Moritz and Jesinghausen, Steffen and Schmid, Hans-Joachim}},
location = {{Berlin}},
title = {{{Flow around Particles in Uniaxially Elongated Capillary Bridges}}},
year = {{2025}},
}
@misc{64657,
author = {{Neudorf, Julian and Neukötter, Moritz}},
title = {{{Fließverhalten von unterschiedlichen Fluiden im Filament Extension Atomizer}}},
year = {{2025}},
}
@article{64662,
abstract = {{
In this study, we investigate the impact of chromium-induced point defects on the nonlinear optical properties and electric-field-induced second harmonic generation (EFISH) in rutile titanium dioxide (TiO
2
). Chromium thin films were deposited by electron beam evaporation on (001)-oriented bulk TiO
2
substrates and subsequently diffused into the lattice in a tube furnace under a nitrogen atmosphere at 900 °C. The introduction of chromium significantly enhanced the third harmonic generation (THG) of a 1560 nm laser, with an amplification factor of up to 8.3, indicative of an enhanced third-order nonlinear susceptibility,
χ
(3)
. Moreover, the application of an external voltage induced a pronounced EFISH signal in the chromium-doped samples, further confirming the enhanced nonlinear response. These results demonstrate that defect engineering via chromium doping in rutile TiO
2
offers a promising pathway for the development of high-performance nonlinear optical devices.
}},
author = {{Brinkmann, Marius and Meier, Falco and Spedt, Vladimir and Meier, Cedrik}},
issn = {{1094-4087}},
journal = {{Optics Express}},
number = {{26}},
publisher = {{Optica Publishing Group}},
title = {{{Boosting third-order nonlinearities in rutile TiO2 by chromium doping}}},
doi = {{10.1364/oe.572063}},
volume = {{33}},
year = {{2025}},
}
@inproceedings{64720,
author = {{Schulte, Carsten and Sentance, Sue and Sparmann, Sören and Altin, Rukiye and Friebroon-Yesharim, Mor and Landman, Martina and Rücker, Michael T. and Satavlekar, Spruha and Siegel, Angela and Tedre, Matti and Tubino, Laura and Vartiainen, Henriikka and VelÁzquez-Iturbide, J. Ángel and Waite, Jane and Wu, Zihan}},
booktitle = {{2024 Working Group Reports on Innovation and Technology in Computer Science Education}},
publisher = {{ACM}},
title = {{{What We Talk About When We Talk About K-12 Computing Education}}},
doi = {{10.1145/3689187.3709612}},
year = {{2025}},
}
@inproceedings{64719,
author = {{Sparmann, Sören and Altin, Rukiye and Mühling, Andreas and Schulte, Carsten}},
booktitle = {{Proceedings of the 25th Koli Calling International Conference on Computing Education Research}},
publisher = {{ACM}},
title = {{{Surfacing Educational Traditions in European K–12 Computing Curricula: A Large-Scale NLP-Based Comparison}}},
doi = {{10.1145/3769994.3770014}},
year = {{2025}},
}
@article{59258,
author = {{Winkler, Michael}},
issn = {{0095-4616}},
journal = {{Applied Mathematics & Optimization}},
number = {{2}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Rough Data in an Evolution System Generalizing 1D Thermoviscoelasticity with Temperature-Dependent Parameters}}},
doi = {{10.1007/s00245-025-10243-9}},
volume = {{91}},
year = {{2025}},
}
@misc{64736,
booktitle = {{J. Lie Theory}},
editor = {{Frahm, Jan and Glöckner, Helge and Hilgert, Joachim and Olafsson, Gestur}},
number = {{4}},
title = {{{Special issue of Journal of Lie Theory dedicated to Karl-Hermann Neeb on the occasion of his 60th birthday}}},
volume = {{35}},
year = {{2025}},
}
@inproceedings{62079,
abstract = {{This paper investigates two modeling approaches for the simulation of the deformation and decomposition behavior of preconsolidated rovings above the thermoplastic matrix{\textquoteright} melting temperature. This is crucial for capturing the local material structure after processes introducing highly localized deformation such as mechanical joining processes between metal and fiber reinforced thermoplastics (FRTP). A generic finite element (FE) model is developed, incorporating interfaces discretized through either cohesive zone (CZ) elements or Coulomb friction-based contacts. The material parameters for the FE elements are derived from the initial stiffness of a statistical volume element (SVE) at micro scale modelled with an Arbitrary-Lagrange-Eulerian method for three load cases. The CZ properties calculated are based on the shear viscosity of the composite. The CZ and contact modelling approaches are evaluated using three load cases of the SVE, comparing force-displacement curves. Under simple loading conditions, such as normal pressure tension and bending, both methods produce similar results; however, in complex load cases, the CZ approach shows clear advantages in handling interface interactions and shows robust simulations. The CZ approach thus presents a promising method for simulating roving decomposition in FRTP-metal joining applications above the matrix{\textquoteright} melting temperature.}},
author = {{Gröger, Benjamin and Gerritzen, Johannes and Hornig, Andreas and Gude, Maik}},
booktitle = {{Sheet Metal 2025}},
editor = {{Meschut, G. and Bobbert, M. and Duflou, J. and Fratini, L. and Hagenah, H. and Martins, P. and Merklein, M. and Micari, F.}},
isbn = {{978-1-64490-354-4}},
keywords = {{Finite Element Method (FEM), Process, Thermoplastic Fiber Reinforced Plastic}},
pages = {{268–275}},
publisher = {{Materials Research Forum LLC, Materials Research Foundations}},
title = {{{Modeling approaches for the decomposition behavior of preconsolidated rovings throughout local deformation processes}}},
doi = {{10.21741/9781644903551-33}},
year = {{2025}},
}
@inproceedings{62080,
abstract = {{The failure behavior of fiber reinforced polymers (FRP) is strongly influenced by their microstructure, i.e. fiber arrangement or local fiber volume content. However, this information cannot be directly used for structural analyses, since it requires a discretization on micrometer level. Therefore, current failure theories do not directly account for such effects, but describe the behavior averaged over an entire specimen. This foundation in experimentally accessible loading conditions leads to purely theory based extension to more complex stress states without direct validation possibilities. This work aims at leveraging micro-scale simulations to obtain failure information under arbitrary loading conditions. The results are propagated to the meso-scale, enabling efficient structural analyses, by means of machine learning (ML). It is shown that the ML model is capable of correctly assessing previously unseen stress states and therefore poses an efficient tool of exploiting information from the micro-scale in larger simulations.}},
author = {{Gerritzen, Johannes and Hornig, Andreas and Gude, Maik}},
booktitle = {{Sheet Metal 2025}},
editor = {{Meschut, G. and Bobbert, M. and Duflou, J. and Fratini, L. and Hagenah, H. and Martins, P. and Merklein, M. and Micari, F.}},
isbn = {{978-1-64490-354-4}},
keywords = {{Failure, Fiber Reinforced Plastic, Machine Learning}},
pages = {{260–267}},
publisher = {{Materials Research Forum LLC, Materials Research Foundations}},
title = {{{Efficient failure information propagation under complex stress states in fiber reinforced polymers: From micro- to meso-scale using machine learning}}},
doi = {{10.21741/9781644903551-32}},
year = {{2025}},
}
@article{62081,
author = {{Gerritzen, Johannes and Gröger, Benjamin and Zscheyge, Matthias and Hornig, Andreas and Gude, Maik}},
issn = {{0264-1275}},
journal = {{Materials & Design}},
publisher = {{Elsevier BV}},
title = {{{3D viscoelastic plastic model coupled with a continuum damage formulation for fiber reinforced polymers}}},
doi = {{10.1016/j.matdes.2025.114969}},
volume = {{260}},
year = {{2025}},
}
@phdthesis{64770,
author = {{Pinaud, Matthieu}},
title = {{{Manifold of mappings and regularity properties of half-Lie groups}}},
doi = {{10.17619/UNIPB/1-2211}},
year = {{2025}},
}
@inproceedings{61149,
abstract = {{The use of continuous fiber-reinforced thermoplastics (FRTP) in automotive industry increases due to their excellent material properties and possibility of rapid processing. The scale spanning heterogeneity of their material structure and its influence on the material behavior, however, presents significant challenges for most joining technologies, such as self-piercing riveting (SPR). During mechanical joining, the material structure is significantly altered within and around the joining zone, heavily influencing the material behavior. A comprehensive understanding of the underlying phenomena of material alteration during the SPR process is essential as basis for validating numerical simulations. This study examines the material structure at ten stages of a step-setting test of SPR with two FRTP sheets with glass-fiber reinforcement. Utilizing X-ray computed tomography (CT), the damage phenomena within different areas of the setting test are analyzed three-dimensionally and key parameters are quantified. Dominating phenomena during the penetration of the rivet into the laminate are fiber failure (FF), interfiber failure (IFF) and fiber bending, while delamination, fiber kinking and roving splitting are also observed. At the final stages, the bottom layers of the second sheet collapse and form a bulge into the cavity of the die.}},
author = {{Dargel, Alrik and Gröger, Benjamin and Schlichter, Malte Christian and Gerritzen, Johannes and Köhler, Daniel and Meschut, Gerson and Gude, Maik and Kupfer, Robert}},
booktitle = {{Proceedings of the 8th International Conference on Integrity-Reliability-Failure (IRF2025)}},
editor = {{Gomes, J.F. Silva and Meguid, Shaker A.}},
isbn = {{9789727523238}},
keywords = {{self-piercing riveting, computed tomography, thermoplastic composites, process-structure-interaction}},
location = {{Porto}},
publisher = {{FEUP}},
title = {{{LOCAL DEFORMATION AND FAILURE OF COMPOSITES DURING SELF-PIERCING RIVETING: A CT BASED MICROSTRUCTURE INVESTIGATION}}},
doi = {{10.24840/978-972-752-323-8}},
year = {{2025}},
}
@article{63828,
author = {{Gerritzen, Johannes and Chopra, Kunal and Reschke, Gregor and Hornig, Andreas and Brosius, Alexander and Gude, Maik}},
issn = {{2666-3309}},
journal = {{Journal of Advanced Joining Processes}},
publisher = {{Elsevier BV}},
title = {{{Quality assurance of clinched joints using explainable machine learning}}},
doi = {{10.1016/j.jajp.2025.100368}},
volume = {{13}},
year = {{2025}},
}
@inproceedings{59441,
abstract = {{Abstract. Accurate Finite Element Modeling (FEM) of joints is essential in the design of complex mechanical systems such as automotive body-in-white (BIW) structures, as it plays a critical role in evaluating their performance. Although well-established techniques exist for modeling rotationally symmetric joints, there remains a significant gap in effectively modeling non-rotationally symmetric joints. These joints are particularly relevant in the automotive BIW, where they can better accommodate anisotropic loading conditions. In this study, strategies for modeling non-rotationally symmetric joints were explored using finite element simulations in LS-DYNA. The findings demonstrate that discrete beam elements can capture the anisotropic characteristics of such joints. Two models were tested: a single-beam model for stiffness periodicity every 90°, and a three-beam model for stiffness periodicity every 120°. Force responses, stress distribution, and sheet bending behaviors were analyzed, confirming that discrete beam elements can accurately represent direction-dependent stiffness. These results establish a foundation for developing advanced joint modeling strategies in complex mechanical systems.}},
author = {{Devulapally, Deekshith Reddy and Tröster, Thomas}},
booktitle = {{Materials Research Proceedings}},
issn = {{2474-395X}},
location = {{Paderborn}},
publisher = {{Materials Research Forum LLC}},
title = {{{Modelling strategies for non-rotationally symmetric joints}}},
doi = {{10.21741/9781644903551-21}},
volume = {{52}},
year = {{2025}},
}
@inproceedings{62041,
author = {{Reckmann, Eileen and Temmen, Katrin}},
booktitle = {{EDULEARN Proceedings}},
editor = {{Gómez Chova, Luis and González Martínez, Chelo and Lees, Joanna}},
issn = {{2340-1117}},
publisher = {{IATED}},
title = {{{Intrinsic Motivation in Stem Outreach: An Analysis of External Factors in Voluntary and School-Based Lab Settings}}},
doi = {{10.21125/edulearn.2025.2462}},
volume = {{1}},
year = {{2025}},
}
@inproceedings{64786,
author = {{Müller, Laura and Meihöfener, Niclas and Siemoneit, Johannes Gabriel and Mozgova, Iryna}},
booktitle = {{Engineering Education for Sustainable Development (EESD2025)}},
title = {{{Introduction of electronic lab notebooks in engineering education - opportunities for a cultural change}}},
doi = {{https://doi.org/10.71779/776}},
year = {{2025}},
}