@inproceedings{64252,
abstract = {{ABSTRACT:The increasing complexity of modern product and production system development, driven by dynamic market demands, supply chain disruptions and economic pressures, poses significant challenges for companies. Existing methodologies often fall short due to their domain-specific focus, inconsistent terminology and lack of integration. To address these challenges, this paper presents a taxonomy for integrative product and production system development. The taxonomy systematically structures key elements, dependencies and processes to improve collaboration, decision-making and communication within organisations. Developed iteratively the taxonomy identifies ten core artefacts. It enables organisations to better plan improvements, synchronise development processes, and select appropriate methods and tools.}},
author = {{Disselkamp, Jan-Philipp and Seidenberg, Tobias and Westphal, Svenja and Lick, Jonas and Ptock, Lukas and Wyrwich, Fabian and Hovemann, Aschot and Dumitrescu, Roman}},
booktitle = {{Proceedings of the Design Society}},
issn = {{2732-527X}},
pages = {{2121--2130}},
publisher = {{Cambridge University Press (CUP)}},
title = {{{Integrative and Integrated product and production system development: a taxonomy for managing dependencies and processes}}},
doi = {{10.1017/pds.2025.10226}},
volume = {{5}},
year = {{2025}},
}
@inproceedings{59517,
author = {{Lick, Jonas and Kattenstroth, Fiona and Trienens, Malte and Disselkamp, Jan-Philipp and Kühn, Arno and Dumitrescu, Roman}},
booktitle = {{2024 IEEE International Conference on Technology Management, Operations and Decisions (ICTMOD)}},
publisher = {{IEEE}},
title = {{{Guidance on a Digital Factory Twin: Proposal for a Reference Architecture}}},
doi = {{10.1109/ictmod63116.2024.10878221}},
year = {{2025}},
}
@inbook{64254,
author = {{Dumitrescu, Roman and Riedel, Oliver and Henke, Michael and Metternich, Joachim and Ihlenfeldt, Steffen and Koldewey, Christian}},
booktitle = {{Gaia-X in industriellen Wertschöpfungsnetzwerken – Erkenntnisse aus der Förderlinie InGAIA-X}},
isbn = {{9783186204165}},
publisher = {{VDI Verlag}},
title = {{{Gaia-X in industriellen Wertschöpfungsnetzwerken – Erkenntnisse aus der Förderlinie InGAIA-X}}},
doi = {{10.51202/9783186204165-i}},
year = {{2025}},
}
@article{64256,
author = {{Rasor, Anja and Koldewey, Christian and Dumitrescu, Roman}},
issn = {{2662-7493}},
journal = {{Nachhaltige Industrie}},
number = {{2}},
pages = {{40--43}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Mit digitalen Hebeln zur Kreislaufwirtschaft}}},
doi = {{10.1007/s43462-025-1406-x}},
volume = {{6}},
year = {{2025}},
}
@proceedings{64257,
editor = {{Dumitrescu, Roman and Hölzle, Katharina}},
publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}},
title = {{{Vorausschau und Technologieplanung - 19. Symposium für Vorausschau und Technologieplanung}}},
doi = {{10.17619/UNIPB/1-2467}},
year = {{2025}},
}
@article{61932,
abstract = {{Substantial improvements in the performance of optical interconnects based on multi-mode fibers are required to support emerging single-channel data transmission rates of 200 Gb/s and 400 Gb/s. Future optical components must combine very high modulation bandwidths—supporting signaling at 100 Gbaud and 200 Gbaud—with reduced spectral width to mitigate chromatic-dispersion-induced pulse broadening and increased brightness to further restrict flux-confining area in multi-mode fibers and thereby increase the effective modal bandwidth (EMB). A particularly promising route to improved performance within standard oxide-confined VCSEL technology is the introduction of multiple isolated or optically coupled oxide-confined apertures, which we refer to collectively as multi-aperture (MA) VCSEL arrays. We show that properly designed MA VCSELs exhibit narrow emission spectra, narrow far-field profiles and extended intrinsic modulation bandwidths, enabling longer-reach data transmission over both multi-mode (MMF) and single-mode fibers (SMF). One approach uses optically isolated apertures with lateral dimensions of approximately 2–3 µm arranged with a pitch of 10–12 µm or less. Such devices demonstrate relaxation oscillation frequencies of around 30 GHz in continuous-wave operation and intrinsic modulation bandwidths approaching 50 GHz. Compared with a conventional single-aperture VCSELs of equivalent oxide-confined area, MA designs can reduce the spectral width (root mean square values < 0.15 nm), lower series resistance (≈50 Ω) and limit junction overheating through more efficient multi-spot heat dissipation at the same total current. As each aperture lases in a single transverse mode, these devices exhibit narrow far-field patterns. In combination with well-defined spacing between emitting spots, they permit tailored restricted launch conditions in MMFs, enhancing effective modal bandwidth. In another MA approach, the apertures are optically coupled such that self-injection locking (SIL) leads to lasing in a single supermode. One may regard one of the supermodes as acting as a master mode controlling the other one. Streak-camera studies reveal post-pulse oscillations in the SIL regime at frequencies up to 100 GHz. MA VCSELs enable a favorable combination of wavelength chirp and chromatic dispersion, extending transmission distances over MMFs beyond those expected for zero-chirp sources and supporting transfer bandwidths up to 60 GHz over kilometer-length SMF links.}},
author = {{Ledentsov, Nikolay N. and Ledentsov, Nikolay and Shchukin, Vitaly A. and Ledentsov, Alexander N. and Makarov, Oleg Yu. and Titkov, Ilya E. and Lindemann, Markus and de Adelsburg Ettmayer, Thomas and Gerhardt, Nils Christopher and Hofmann, Martin R. and Chen, Xin and Hurley, Jason E. and Dong, Hao and Li, Ming-Jun}},
issn = {{2304-6732}},
journal = {{Photonics}},
number = {{10}},
publisher = {{MDPI AG}},
title = {{{VCSELs: Influence of Design on Performance and Data Transmission over Multi-Mode and Single-Mode Fibers}}},
doi = {{10.3390/photonics12101037}},
volume = {{12}},
year = {{2025}},
}
@article{61931,
abstract = {{Recent research revealed that single-mode vertical-cavity surface-emitting lasers under spin injection (spin-VCSELs) have the potential to revolutionize laser technology for short-haul optical communications. While previous studies have focused solely on single-mode operation, this study introduces multimode spin-VCSELs. We experimentally demonstrate the existence of multi-resonant polarization dynamics when spin is injected, a phenomenon previously unobserved. The development opens the door to significantly faster and more efficient optical communication systems by harnessing the collective behavior of multiple laser modes. Furthermore, we lay the groundwork for understanding multimode operation through the extension of the single-mode spin–flip model, which forms the basis for present and future analyses of multimode spin-laser operation. This work is an important step toward realizing the full potential of spin-VCSELs and, thus, enables significantly improved performance of spin-VCSEL-based optical networks in the future.}},
author = {{Diiankova, Uliana and Drong, Mariusz and Pusch, Tobias and Michalzik, Rainer and Lindemann, Markus and Gerhardt, Nils Christopher and Hofmann, Martin R.}},
issn = {{2378-0967}},
journal = {{APL Photonics}},
number = {{10}},
publisher = {{AIP Publishing}},
title = {{{Multimode vertical-cavity surface-emitting lasers under spin injection}}},
doi = {{10.1063/5.0286998}},
volume = {{10}},
year = {{2025}},
}
@article{56717,
abstract = {{We establish a multiresolution analysis on the space $\text{Herm}(n)$ of
$n\times n$ complex Hermitian matrices which is adapted to invariance under
conjugation by the unitary group $U(n).$ The orbits under this action are
parametrized by the possible ordered spectra of Hermitian matrices, which
constitute a closed Weyl chamber of type $A_{n-1}$ in $\mathbb R^n.$ The space
$L^2(\text{Herm}(n))^{U(n)}$ of radial, i.e. $U(n)$-invariant $L^2$-functions
on $\text{Herm}(n)$ is naturally identified with a certain weighted $L^2$-space
on this chamber.
The scale spaces of our multiresolution analysis are obtained by usual dyadic
dilations as well as generalized translations of a scaling function, where the
generalized translation is a hypergroup translation which respects the radial
geometry. We provide a concise criterion to characterize orthonormal wavelet
bases and show that such bases always exist. They provide natural orthonormal
bases of the space $L^2(\text{Herm}(n))^{U(n)}.$
Furthermore, we show how to obtain radial scaling functions from classical
scaling functions on $\mathbb R^{n}$. Finally, generalizations related to the
Cartan decompositions for general compact Lie groups are indicated.}},
author = {{Langen, Lukas and Rösler, Margit}},
journal = {{Indagationes Mathematicae}},
number = {{6}},
pages = {{1671--1694}},
publisher = {{Elsevier}},
title = {{{Multiresolution analysis on spectra of hermitian matrices}}},
volume = {{36}},
year = {{2025}},
}
@article{64289,
abstract = {{Abstract
Motivated by asymptotic symmetry groups in general relativity, we consider projective unitary representations
$$\overline{\rho }$$
ρ
¯
of the Lie group
$${{\,\textrm{Diff}\,}}_c(M)$$
Diff
c
(
M
)
of compactly supported diffeomorphisms of a smooth manifold M that satisfy a so-called generalized positive energy condition. In particular, this captures representations that are in a suitable sense compatible with a KMS state on the von Neumann algebra generated by
$$\overline{\rho }$$
ρ
¯
. We show that if M is connected and
$$\dim (M) > 1$$
dim
(
M
)
>
1
, then any such representation is necessarily trivial on the identity component
$${{\,\textrm{Diff}\,}}_c(M)_0$$
Diff
c
(
M
)
0
. As an intermediate step towards this result, we determine the continuous second Lie algebra cohomology
$$H^2_\textrm{ct}(\mathcal {X}_c(M), \mathbb {R})$$
H
ct
2
(
X
c
(
M
)
,
R
)
of the Lie algebra of compactly supported vector fields. This is subtly different from Gelfand–Fuks cohomology in view of the compact support condition.}},
author = {{Janssens, Bas and Niestijl, Milan}},
issn = {{0010-3616}},
journal = {{Communications in Mathematical Physics}},
number = {{2}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Generalized Positive Energy Representations of the Group of Compactly Supported Diffeomorphisms}}},
doi = {{10.1007/s00220-024-05226-w}},
volume = {{406}},
year = {{2025}},
}
@inproceedings{59910,
abstract = {{The connection between inconsistent databases and Dung’s abstract argumentation framework has recently drawn growing interest. Specifically, an inconsistent database, involving certain types of integrity constraints such as functional and inclusion dependencies, can be viewed as an argumentation framework in Dung’s setting. Nevertheless, no prior work has explored the exact expressive power of Dung’s theory of argumentation when compared to inconsistent databases and integrity constraints. In this paper, we close this gap by arguing that an argumentation framework can also be viewed as an inconsistent database. We first establish a connection between subset-repairs for databases and extensions for AFs considering conflict-free, naive, admissible, and preferred semantics. Further, we define a new family of attribute-based repairs based on the principle of maximal content preservation. The effectiveness of these repairs is then highlighted by connecting them to stable, semi-stable, and stage semantics. Our main contributions include translating an argumentation framework into a database together with integrity constraints. Moreover, this translation can be achieved in polynomial time, which is essential in transferring complexity results between the two formalisms.}},
author = {{Mahmood, Yasir and Hecher, Markus and Ngonga Ngomo, Axel-Cyrille}},
booktitle = {{Proceedings of the AAAI Conference on Artificial Intelligence}},
issn = {{2374-3468}},
number = {{14}},
pages = {{15058--15066}},
publisher = {{Association for the Advancement of Artificial Intelligence (AAAI)}},
title = {{{Dung’s Argumentation Framework: Unveiling the Expressive Power with Inconsistent Databases}}},
doi = {{10.1609/aaai.v39i14.33651}},
volume = {{39}},
year = {{2025}},
}
@article{64551,
abstract = {{Laterally coupled vertical-cavity surface-emitting lasers (VCSELs) can exhibit additional resonances at high modulation frequencies that can substantially increase the laser’s modulation bandwidth. State-of-the-art laterally coupled devices require non-standard manufacturing technology and precise tuning of the currents supplied to each cavity separately to form optical supermodes suitable for such resonances. Here, we report on a novel switching phenomenon in laterally coupled VCSEL structures having only a single common electric contact and manufactured in a standard oxide-confined VCSEL geometry. At lower currents, they can be operated in a weakly coupled (WCR) regime and, at higher currents, in an injection-locked (IL) regime, enabling fundamentally different spectral and dynamic features. In the WCR, both optical supermodes lase and a narrow tunable plasma-assisted peak at their beating frequency is observed for each of the apertures, with a current-dependent frequency tuning and anti-phase intensity oscillations in each of the cavities. In contrast, in the IL regimes, only one (anti-symmetric) supermode lases. This adds a broader resonance to the modulation response while the intensity oscillations in both cavities are in-phase. Only the IL regime can result in increased modulation bandwidth of the system. Measurements of the pulse responses and continuous modulation up to 70 GHz for both operational regimes are presented and compared with simulations of our distributed rate equation model whose parameters are extracted from full-wave electromagnetic simulations of the device, including the temperature distribution in the device. Excellent agreement is found and enables comprehensive understanding of the dynamics of supermodes in oxide-confined coupled cavity VCSELs.}},
author = {{Lindemann, M. and D’Alessandro, M. and Ledentsov, N. and Makarov, O. Y. and Ledentsov, N. N. and Tibaldi, A. and Gerhardt, Nils Christopher and Hofmann, M. R.}},
issn = {{0021-8979}},
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{64293,
author = {{Gerhardt, Nils Christopher and Hofmann, Martin R. and Zens, Leon and Möller, Jens and Besaga, Vira}},
booktitle = {{Practical Holography XXXIX: Displays, Materials, and Applications}},
title = {{{Quantitative holography for the characterisation of semiconductor amplifieres and lasers}}},
doi = {{10.1117/12.3041318}},
year = {{2025}},
}
@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}},
}
@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}},
}
@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{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{64795,
author = {{Ebert, Marc and Temmen, Katrin}},
location = {{Oldenburg}},
title = {{{Über Rätsel zur Quantenphysik – Eine spielerische Heranführung an ein abstraktes Thema}}},
year = {{2025}},
}