---
_id: '55159'
abstract:
- lang: eng
  text: "We introduce a method based on Gaussian process regression to identify discrete
    variational principles from observed solutions of a field theory. The method is
    based on the data-based identification of a discrete Lagrangian density. It is
    a geometric machine learning technique in the sense that the variational structure
    of the true field theory is reflected in the data-driven model by design. We provide
    a rigorous convergence statement of the method. The proof circumvents challenges
    posed by the ambiguity of discrete Lagrangian densities in the inverse problem
    of variational calculus.\r\nMoreover, our method can be used to quantify model
    uncertainty in the equations of motions and any linear observable of the discrete
    field theory. This is illustrated on the example of the discrete wave equation
    and Schrödinger equation.\r\nThe article constitutes an extension of our previous
    article  arXiv:2404.19626 for the data-driven identification of (discrete) Lagrangians
    for variational dynamics from an ode setting to the setting of discrete pdes."
author:
- first_name: Christian
  full_name: Offen, Christian
  id: '85279'
  last_name: Offen
  orcid: 0000-0002-5940-8057
citation:
  ama: Offen C. Machine learning of discrete field theories with guaranteed convergence
    and uncertainty quantification.
  apa: Offen, C. (n.d.). <i>Machine learning of discrete field theories with guaranteed
    convergence and uncertainty quantification</i>.
  bibtex: '@article{Offen, title={Machine learning of discrete field theories with
    guaranteed convergence and uncertainty quantification}, author={Offen, Christian}
    }'
  chicago: Offen, Christian. “Machine Learning of Discrete Field Theories with Guaranteed
    Convergence and Uncertainty Quantification,” n.d.
  ieee: C. Offen, “Machine learning of discrete field theories with guaranteed convergence
    and uncertainty quantification.” .
  mla: Offen, Christian. <i>Machine Learning of Discrete Field Theories with Guaranteed
    Convergence and Uncertainty Quantification</i>.
  short: C. Offen, (n.d.).
date_created: 2024-07-10T13:43:50Z
date_updated: 2024-08-12T13:43:32Z
ddc:
- '510'
department:
- _id: '636'
external_id:
  arxiv:
  - '2407.07642'
file:
- access_level: open_access
  content_type: application/pdf
  creator: coffen
  date_created: 2024-07-10T13:39:32Z
  date_updated: 2024-07-10T13:39:32Z
  description: |-
    We introduce a method based on Gaussian process regression to identify discrete
    variational principles from observed solutions of a field theory. The method is based on the data-based identification of a discrete Lagrangian density. It is a geometric machine learning technique in the sense that the variational structure of the true field theory is reflected in the data-driven model by design.
    We provide a rigorous convergence statement of the method.
    The proof circumvents challenges posed by the ambiguity of discrete Lagrangian densities in the inverse problem of variational calculus.
    Moreover, our method can be used to quantify model uncertainty in the equations of motions and any linear observable of the discrete field theory.
    This is illustrated on the example of the discrete wave equation and Schrödinger equation.
    The article constitutes an extension of our previous article for the data-driven identification of (discrete) Lagrangians for variational dynamics from an ode setting to the setting of discrete pdes.
  file_id: '55160'
  file_name: L_Collocation.pdf
  file_size: 4569314
  relation: main_file
  title: Machine learning of discrete field theories with guaranteed convergence and
    uncertainty quantification
file_date_updated: 2024-07-10T13:39:32Z
has_accepted_license: '1'
keyword:
- System identification
- inverse problem of variational calculus
- Gaussian process
- Lagrangian learning
- physics informed machine learning
- geometry aware learning
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
oa: '1'
page: '28'
project:
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication_status: submitted
related_material:
  link:
  - description: GitHub
    relation: software
    url: https://github.com/Christian-Offen/Lagrangian_GP_PDE
status: public
title: Machine learning of discrete field theories with guaranteed convergence and
  uncertainty quantification
type: preprint
user_id: '85279'
year: '2024'
...
---
_id: '45972'
author:
- first_name: Balázs
  full_name: Kovács, Balázs
  id: '100441'
  last_name: Kovács
  orcid: 0000-0001-9872-3474
citation:
  ama: Kovács B. Numerical surgery for mean curvature flow of surfaces. <i>SIAM Journal
    on Scientific Computing</i>. 2024;46(2):A645--A669. doi:<a href="https://doi.org/10.1137/22M1531919">10.1137/22M1531919</a>
  apa: Kovács, B. (2024). Numerical surgery for mean curvature flow of surfaces. <i>SIAM
    Journal on Scientific Computing</i>, <i>46</i>(2), A645--A669. <a href="https://doi.org/10.1137/22M1531919">https://doi.org/10.1137/22M1531919</a>
  bibtex: '@article{Kovács_2024, title={Numerical surgery for mean curvature flow
    of surfaces}, volume={46}, DOI={<a href="https://doi.org/10.1137/22M1531919">10.1137/22M1531919</a>},
    number={2}, journal={SIAM Journal on Scientific Computing}, author={Kovács, Balázs},
    year={2024}, pages={A645--A669} }'
  chicago: 'Kovács, Balázs. “Numerical Surgery for Mean Curvature Flow of Surfaces.”
    <i>SIAM Journal on Scientific Computing</i> 46, no. 2 (2024): A645--A669. <a href="https://doi.org/10.1137/22M1531919">https://doi.org/10.1137/22M1531919</a>.'
  ieee: 'B. Kovács, “Numerical surgery for mean curvature flow of surfaces,” <i>SIAM
    Journal on Scientific Computing</i>, vol. 46, no. 2, pp. A645--A669, 2024, doi:
    <a href="https://doi.org/10.1137/22M1531919">10.1137/22M1531919</a>.'
  mla: Kovács, Balázs. “Numerical Surgery for Mean Curvature Flow of Surfaces.” <i>SIAM
    Journal on Scientific Computing</i>, vol. 46, no. 2, 2024, pp. A645--A669, doi:<a
    href="https://doi.org/10.1137/22M1531919">10.1137/22M1531919</a>.
  short: B. Kovács, SIAM Journal on Scientific Computing 46 (2024) A645--A669.
date_created: 2023-07-10T12:32:34Z
date_updated: 2024-08-27T07:42:56Z
department:
- _id: '841'
doi: 10.1137/22M1531919
extern: '1'
intvolume: '        46'
issue: '2'
language:
- iso: eng
page: A645--A669
publication: SIAM Journal on Scientific Computing
status: public
title: Numerical surgery for mean curvature flow of surfaces
type: journal_article
user_id: '100441'
volume: 46
year: '2024'
...
---
_id: '56497'
article_number: '114258'
author:
- first_name: Chiara
  full_name: Cappello, Chiara
  last_name: Cappello
- first_name: Reza
  full_name: Naserasr, Reza
  last_name: Naserasr
- first_name: Eckhard
  full_name: Steffen, Eckhard
  id: '15548'
  last_name: Steffen
  orcid: 0000-0002-9808-7401
- first_name: Zhouningxin
  full_name: Wang, Zhouningxin
  last_name: Wang
citation:
  ama: Cappello C, Naserasr R, Steffen E, Wang Z. Critically 3-frustrated signed graphs.
    <i>Discrete Mathematics</i>. 2024;348(1). doi:<a href="https://doi.org/10.1016/j.disc.2024.114258">10.1016/j.disc.2024.114258</a>
  apa: Cappello, C., Naserasr, R., Steffen, E., &#38; Wang, Z. (2024). Critically
    3-frustrated signed graphs. <i>Discrete Mathematics</i>, <i>348</i>(1), Article
    114258. <a href="https://doi.org/10.1016/j.disc.2024.114258">https://doi.org/10.1016/j.disc.2024.114258</a>
  bibtex: '@article{Cappello_Naserasr_Steffen_Wang_2024, title={Critically 3-frustrated
    signed graphs}, volume={348}, DOI={<a href="https://doi.org/10.1016/j.disc.2024.114258">10.1016/j.disc.2024.114258</a>},
    number={1114258}, journal={Discrete Mathematics}, publisher={Elsevier BV}, author={Cappello,
    Chiara and Naserasr, Reza and Steffen, Eckhard and Wang, Zhouningxin}, year={2024}
    }'
  chicago: Cappello, Chiara, Reza Naserasr, Eckhard Steffen, and Zhouningxin Wang.
    “Critically 3-Frustrated Signed Graphs.” <i>Discrete Mathematics</i> 348, no.
    1 (2024). <a href="https://doi.org/10.1016/j.disc.2024.114258">https://doi.org/10.1016/j.disc.2024.114258</a>.
  ieee: 'C. Cappello, R. Naserasr, E. Steffen, and Z. Wang, “Critically 3-frustrated
    signed graphs,” <i>Discrete Mathematics</i>, vol. 348, no. 1, Art. no. 114258,
    2024, doi: <a href="https://doi.org/10.1016/j.disc.2024.114258">10.1016/j.disc.2024.114258</a>.'
  mla: Cappello, Chiara, et al. “Critically 3-Frustrated Signed Graphs.” <i>Discrete
    Mathematics</i>, vol. 348, no. 1, 114258, Elsevier BV, 2024, doi:<a href="https://doi.org/10.1016/j.disc.2024.114258">10.1016/j.disc.2024.114258</a>.
  short: C. Cappello, R. Naserasr, E. Steffen, Z. Wang, Discrete Mathematics 348 (2024).
date_created: 2024-10-10T12:27:11Z
date_updated: 2024-10-10T12:28:13Z
department:
- _id: '542'
doi: 10.1016/j.disc.2024.114258
intvolume: '       348'
issue: '1'
language:
- iso: eng
publication: Discrete Mathematics
publication_identifier:
  issn:
  - 0012-365X
publication_status: published
publisher: Elsevier BV
status: public
title: Critically 3-frustrated signed graphs
type: journal_article
user_id: '15540'
volume: 348
year: '2024'
...
---
_id: '59791'
author:
- first_name: Sofya
  full_name: Maslovskaya, Sofya
  id: '87909'
  last_name: Maslovskaya
- first_name: Sina
  full_name: Ober-Blöbaum, Sina
  id: '16494'
  last_name: Ober-Blöbaum
citation:
  ama: 'Maslovskaya S, Ober-Blöbaum S. Symplectic Methods in Deep Learning. In: <i>IFAC-PapersOnLine</i>.
    Vol 58. Elsevier BV; 2024:85-90. doi:<a href="https://doi.org/10.1016/j.ifacol.2024.10.118">10.1016/j.ifacol.2024.10.118</a>'
  apa: Maslovskaya, S., &#38; Ober-Blöbaum, S. (2024). Symplectic Methods in Deep
    Learning. <i>IFAC-PapersOnLine</i>, <i>58</i>(17), 85–90. <a href="https://doi.org/10.1016/j.ifacol.2024.10.118">https://doi.org/10.1016/j.ifacol.2024.10.118</a>
  bibtex: '@inproceedings{Maslovskaya_Ober-Blöbaum_2024, title={Symplectic Methods
    in Deep Learning}, volume={58}, DOI={<a href="https://doi.org/10.1016/j.ifacol.2024.10.118">10.1016/j.ifacol.2024.10.118</a>},
    number={17}, booktitle={IFAC-PapersOnLine}, publisher={Elsevier BV}, author={Maslovskaya,
    Sofya and Ober-Blöbaum, Sina}, year={2024}, pages={85–90} }'
  chicago: Maslovskaya, Sofya, and Sina Ober-Blöbaum. “Symplectic Methods in Deep
    Learning.” In <i>IFAC-PapersOnLine</i>, 58:85–90. Elsevier BV, 2024. <a href="https://doi.org/10.1016/j.ifacol.2024.10.118">https://doi.org/10.1016/j.ifacol.2024.10.118</a>.
  ieee: 'S. Maslovskaya and S. Ober-Blöbaum, “Symplectic Methods in Deep Learning,”
    in <i>IFAC-PapersOnLine</i>, 2024, vol. 58, no. 17, pp. 85–90, doi: <a href="https://doi.org/10.1016/j.ifacol.2024.10.118">10.1016/j.ifacol.2024.10.118</a>.'
  mla: Maslovskaya, Sofya, and Sina Ober-Blöbaum. “Symplectic Methods in Deep Learning.”
    <i>IFAC-PapersOnLine</i>, vol. 58, no. 17, Elsevier BV, 2024, pp. 85–90, doi:<a
    href="https://doi.org/10.1016/j.ifacol.2024.10.118">10.1016/j.ifacol.2024.10.118</a>.
  short: 'S. Maslovskaya, S. Ober-Blöbaum, in: IFAC-PapersOnLine, Elsevier BV, 2024,
    pp. 85–90.'
date_created: 2025-05-05T09:21:13Z
date_updated: 2025-05-05T09:22:27Z
department:
- _id: '636'
doi: 10.1016/j.ifacol.2024.10.118
intvolume: '        58'
issue: '17'
language:
- iso: eng
page: 85-90
publication: IFAC-PapersOnLine
publication_identifier:
  issn:
  - 2405-8963
publication_status: published
publisher: Elsevier BV
status: public
title: Symplectic Methods in Deep Learning
type: conference
user_id: '87909'
volume: 58
year: '2024'
...
---
_id: '59801'
author:
- first_name: Frédéric
  full_name: Jean, Frédéric
  last_name: Jean
- first_name: Sofya
  full_name: Maslovskaya, Sofya
  id: '87909'
  last_name: Maslovskaya
citation:
  ama: Jean F, Maslovskaya S. Inverse optimal control problem in the non autonomous
    linear-quadratic case. Published online 2024.
  apa: Jean, F., &#38; Maslovskaya, S. (2024). <i>Inverse optimal control problem
    in the non autonomous linear-quadratic case</i>.
  bibtex: '@article{Jean_Maslovskaya_2024, title={Inverse optimal control problem
    in the non autonomous linear-quadratic case}, author={Jean, Frédéric and Maslovskaya,
    Sofya}, year={2024} }'
  chicago: Jean, Frédéric, and Sofya Maslovskaya. “Inverse Optimal Control Problem
    in the Non Autonomous Linear-Quadratic Case,” 2024.
  ieee: F. Jean and S. Maslovskaya, “Inverse optimal control problem in the non autonomous
    linear-quadratic case.” 2024.
  mla: Jean, Frédéric, and Sofya Maslovskaya. <i>Inverse Optimal Control Problem in
    the Non Autonomous Linear-Quadratic Case</i>. 2024.
  short: F. Jean, S. Maslovskaya, (2024).
date_created: 2025-05-05T09:42:19Z
date_updated: 2025-05-05T09:43:05Z
department:
- _id: '636'
language:
- iso: eng
status: public
title: Inverse optimal control problem in the non autonomous linear-quadratic case
type: preprint
user_id: '87909'
year: '2024'
...
---
_id: '55078'
abstract:
- lang: eng
  text: "This paper develops and discusses a residual-based a posteriori error\r\nestimate
    and a space--time adaptive algorithm for solving parabolic surface\r\npartial
    differential equations on closed stationary surfaces. The full\r\ndiscretization
    uses the surface finite element method in space and the backward\r\nEuler method
    in time. The proposed error indicator bounds the error quantities\r\nglobally
    in space from above and below, and globally in time from above and\r\nlocally
    from below. A space--time adaptive algorithm is proposed using the\r\nderived
    error indicator. Numerical experiments illustrate and complement the\r\ntheory."
author:
- first_name: Balázs
  full_name: Kovács, Balázs
  id: '100441'
  last_name: Kovács
  orcid: 0000-0001-9872-3474
- first_name: Michael Frederik Raúl
  full_name: Lantelme, Michael Frederik Raúl
  id: '102867'
  last_name: Lantelme
citation:
  ama: Kovács B, Lantelme MFR. A posteriori error estimates for parabolic partial
    differential equations on stationary surfaces. <i>arXiv:240702101</i>. Published
    online 2024.
  apa: Kovács, B., &#38; Lantelme, M. F. R. (2024). A posteriori error estimates for
    parabolic partial differential equations on stationary surfaces. In <i>arXiv:2407.02101</i>.
  bibtex: '@article{Kovács_Lantelme_2024, title={A posteriori error estimates for
    parabolic partial differential equations on stationary surfaces}, journal={arXiv:2407.02101},
    author={Kovács, Balázs and Lantelme, Michael Frederik Raúl}, year={2024} }'
  chicago: Kovács, Balázs, and Michael Frederik Raúl Lantelme. “A Posteriori Error
    Estimates for Parabolic Partial Differential Equations on Stationary Surfaces.”
    <i>ArXiv:2407.02101</i>, 2024.
  ieee: B. Kovács and M. F. R. Lantelme, “A posteriori error estimates for parabolic
    partial differential equations on stationary surfaces,” <i>arXiv:2407.02101</i>.
    2024.
  mla: Kovács, Balázs, and Michael Frederik Raúl Lantelme. “A Posteriori Error Estimates
    for Parabolic Partial Differential Equations on Stationary Surfaces.” <i>ArXiv:2407.02101</i>,
    2024.
  short: B. Kovács, M.F.R. Lantelme, ArXiv:2407.02101 (2024).
date_created: 2024-07-04T12:53:47Z
date_updated: 2026-02-18T14:45:36Z
department:
- _id: '841'
external_id:
  arxiv:
  - '2407.02101'
language:
- iso: eng
publication: arXiv:2407.02101
status: public
title: A posteriori error estimates for parabolic partial differential equations on
  stationary surfaces
type: preprint
user_id: '100441'
year: '2024'
...
---
_id: '56429'
abstract:
- lang: eng
  text: "It is known that the notion of a transitive subgroup of a permutation group\r\n$P$
    extends naturally to the subsets of $P$. We study transitive subsets of the\r\nwreath
    product $G \\wr S_n$, where $G$ is a finite abelian group. This includes\r\nthe
    hyperoctahedral group for $G=C_2$. We give structural characterisations of\r\ntransitive
    subsets using the character theory of $G \\wr S_n$ and interpret such\r\nsubsets
    as designs in the conjugacy class association scheme of $G \\wr S_n$. In\r\nparticular,
    we prove a generalisation of the Livingstone-Wagner theorem and\r\ngive explicit
    constructions of transitive sets. Moreover, we establish\r\nconnections to orthogonal
    polynomials, namely the Charlier polynomials, and use\r\nthem to study codes and
    designs in $C_r \\wr S_n$. Many of our results extend\r\nresults about the symmetric
    group $S_n$."
author:
- first_name: Lukas-André Dominik
  full_name: Klawuhn, Lukas-André Dominik
  id: '91965'
  last_name: Klawuhn
  orcid: 0009-0009-7736-4885
- first_name: Kai-Uwe
  full_name: Schmidt, Kai-Uwe
  last_name: Schmidt
citation:
  ama: Klawuhn L-AD, Schmidt K-U. Transitivity in wreath products with symmetric groups.
    <i>arXiv:240920495</i>. Published online 2024.
  apa: Klawuhn, L.-A. D., &#38; Schmidt, K.-U. (2024). Transitivity in wreath products
    with symmetric groups. In <i>arXiv:2409.20495</i>.
  bibtex: '@article{Klawuhn_Schmidt_2024, title={Transitivity in wreath products with
    symmetric groups}, journal={arXiv:2409.20495}, author={Klawuhn, Lukas-André Dominik
    and Schmidt, Kai-Uwe}, year={2024} }'
  chicago: Klawuhn, Lukas-André Dominik, and Kai-Uwe Schmidt. “Transitivity in Wreath
    Products with Symmetric Groups.” <i>ArXiv:2409.20495</i>, 2024.
  ieee: L.-A. D. Klawuhn and K.-U. Schmidt, “Transitivity in wreath products with
    symmetric groups,” <i>arXiv:2409.20495</i>. 2024.
  mla: Klawuhn, Lukas-André Dominik, and Kai-Uwe Schmidt. “Transitivity in Wreath
    Products with Symmetric Groups.” <i>ArXiv:2409.20495</i>, 2024.
  short: L.-A.D. Klawuhn, K.-U. Schmidt, ArXiv:2409.20495 (2024).
date_created: 2024-10-08T13:14:45Z
date_updated: 2024-11-15T12:34:03Z
department:
- _id: '100'
external_id:
  arxiv:
  - '2409.20495'
language:
- iso: eng
page: '38'
publication: arXiv:2409.20495
status: public
title: Transitivity in wreath products with symmetric groups
type: preprint
user_id: '91965'
year: '2024'
...
---
_id: '59171'
abstract:
- lang: eng
  text: To model dynamical systems on networks with higher-order (non-pairwise) interactions,
    we recently introduced a new class of ordinary differential equations (ODEs) on
    hypernetworks. Here, we consider one-parameter synchrony breaking bifurcations
    in such ODEs. We call a synchrony breaking steady-state branch ‘reluctant’ if
    it is tangent to a synchrony space, but does not lie inside it. We prove that
    reluctant synchrony breaking is ubiquitous in hypernetwork systems, by constructing
    a large class of examples that support it. We also give an explicit formula for
    the order of tangency to the synchrony space of a reluctant steady-state branch.
author:
- first_name: Sören
  full_name: von der Gracht, Sören
  id: '97359'
  last_name: von der Gracht
  orcid: 0000-0002-8054-2058
- first_name: Eddie
  full_name: Nijholt, Eddie
  last_name: Nijholt
- first_name: Bob
  full_name: Rink, Bob
  last_name: Rink
citation:
  ama: 'von der Gracht S, Nijholt E, Rink B. Higher-order interactions lead to ‘reluctant’
    synchrony breaking. <i>Proceedings of the Royal Society A: Mathematical, Physical
    and Engineering Sciences</i>. 2024;480(2301). doi:<a href="https://doi.org/10.1098/rspa.2023.0945">10.1098/rspa.2023.0945</a>'
  apa: 'von der Gracht, S., Nijholt, E., &#38; Rink, B. (2024). Higher-order interactions
    lead to ‘reluctant’ synchrony breaking. <i>Proceedings of the Royal Society A:
    Mathematical, Physical and Engineering Sciences</i>, <i>480</i>(2301). <a href="https://doi.org/10.1098/rspa.2023.0945">https://doi.org/10.1098/rspa.2023.0945</a>'
  bibtex: '@article{von der Gracht_Nijholt_Rink_2024, title={Higher-order interactions
    lead to ‘reluctant’ synchrony breaking}, volume={480}, DOI={<a href="https://doi.org/10.1098/rspa.2023.0945">10.1098/rspa.2023.0945</a>},
    number={2301}, journal={Proceedings of the Royal Society A: Mathematical, Physical
    and Engineering Sciences}, publisher={The Royal Society}, author={von der Gracht,
    Sören and Nijholt, Eddie and Rink, Bob}, year={2024} }'
  chicago: 'Gracht, Sören von der, Eddie Nijholt, and Bob Rink. “Higher-Order Interactions
    Lead to ‘Reluctant’ Synchrony Breaking.” <i>Proceedings of the Royal Society A:
    Mathematical, Physical and Engineering Sciences</i> 480, no. 2301 (2024). <a href="https://doi.org/10.1098/rspa.2023.0945">https://doi.org/10.1098/rspa.2023.0945</a>.'
  ieee: 'S. von der Gracht, E. Nijholt, and B. Rink, “Higher-order interactions lead
    to ‘reluctant’ synchrony breaking,” <i>Proceedings of the Royal Society A: Mathematical,
    Physical and Engineering Sciences</i>, vol. 480, no. 2301, 2024, doi: <a href="https://doi.org/10.1098/rspa.2023.0945">10.1098/rspa.2023.0945</a>.'
  mla: 'von der Gracht, Sören, et al. “Higher-Order Interactions Lead to ‘Reluctant’
    Synchrony Breaking.” <i>Proceedings of the Royal Society A: Mathematical, Physical
    and Engineering Sciences</i>, vol. 480, no. 2301, The Royal Society, 2024, doi:<a
    href="https://doi.org/10.1098/rspa.2023.0945">10.1098/rspa.2023.0945</a>.'
  short: 'S. von der Gracht, E. Nijholt, B. Rink, Proceedings of the Royal Society
    A: Mathematical, Physical and Engineering Sciences 480 (2024).'
date_created: 2025-03-27T10:15:06Z
date_updated: 2025-03-27T10:19:56Z
ddc:
- '510'
department:
- _id: '101'
doi: 10.1098/rspa.2023.0945
file:
- access_level: open_access
  content_type: application/pdf
  creator: svdg
  date_created: 2025-03-27T10:16:20Z
  date_updated: 2025-03-27T10:19:48Z
  file_id: '59172'
  file_name: higher-order-interactions-lead-to-reluctant-synchrony-breaking.pdf
  file_size: 820435
  relation: main_file
file_date_updated: 2025-03-27T10:19:48Z
has_accepted_license: '1'
intvolume: '       480'
issue: '2301'
keyword:
- higher-order interactions
- synchrony breaking
- network dynamics
- coupled cell systems
language:
- iso: eng
oa: '1'
publication: 'Proceedings of the Royal Society A: Mathematical, Physical and Engineering
  Sciences'
publication_identifier:
  issn:
  - 1364-5021
  - 1471-2946
publication_status: published
publisher: The Royal Society
status: public
title: Higher-order interactions lead to ‘reluctant’ synchrony breaking
type: journal_article
user_id: '97359'
volume: 480
year: '2024'
...
---
_id: '21199'
abstract:
- lang: eng
  text: "As in almost every other branch of science, the major advances in data\r\nscience
    and machine learning have also resulted in significant improvements\r\nregarding
    the modeling and simulation of nonlinear dynamical systems. It is\r\nnowadays
    possible to make accurate medium to long-term predictions of highly\r\ncomplex
    systems such as the weather, the dynamics within a nuclear fusion\r\nreactor,
    of disease models or the stock market in a very efficient manner. In\r\nmany cases,
    predictive methods are advertised to ultimately be useful for\r\ncontrol, as the
    control of high-dimensional nonlinear systems is an engineering\r\ngrand challenge
    with huge potential in areas such as clean and efficient energy\r\nproduction,
    or the development of advanced medical devices. However, the\r\nquestion of how
    to use a predictive model for control is often left unanswered\r\ndue to the associated
    challenges, namely a significantly higher system\r\ncomplexity, the requirement
    of much larger data sets and an increased and often\r\nproblem-specific modeling
    effort. To solve these issues, we present a universal\r\nframework (which we call
    QuaSiModO:\r\nQuantization-Simulation-Modeling-Optimization) to transform arbitrary\r\npredictive
    models into control systems and use them for feedback control. The\r\nadvantages
    of our approach are a linear increase in data requirements with\r\nrespect to
    the control dimension, performance guarantees that rely exclusively\r\non the
    accuracy of the predictive model, and only little prior knowledge\r\nrequirements
    in control theory to solve complex control problems. In particular\r\nthe latter
    point is of key importance to enable a large number of researchers\r\nand practitioners
    to exploit the ever increasing capabilities of predictive\r\nmodels for control
    in a straight-forward and systematic fashion."
article_number: '110840'
author:
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
- first_name: Katharina
  full_name: Bieker, Katharina
  id: '32829'
  last_name: Bieker
citation:
  ama: Peitz S, Bieker K. On the Universal Transformation of Data-Driven Models to
    Control Systems. <i>Automatica</i>. 2023;149. doi:<a href="https://doi.org/10.1016/j.automatica.2022.110840">10.1016/j.automatica.2022.110840</a>
  apa: Peitz, S., &#38; Bieker, K. (2023). On the Universal Transformation of Data-Driven
    Models to Control Systems. <i>Automatica</i>, <i>149</i>, Article 110840. <a href="https://doi.org/10.1016/j.automatica.2022.110840">https://doi.org/10.1016/j.automatica.2022.110840</a>
  bibtex: '@article{Peitz_Bieker_2023, title={On the Universal Transformation of Data-Driven
    Models to Control Systems}, volume={149}, DOI={<a href="https://doi.org/10.1016/j.automatica.2022.110840">10.1016/j.automatica.2022.110840</a>},
    number={110840}, journal={Automatica}, publisher={Elsevier}, author={Peitz, Sebastian
    and Bieker, Katharina}, year={2023} }'
  chicago: Peitz, Sebastian, and Katharina Bieker. “On the Universal Transformation
    of Data-Driven Models to Control Systems.” <i>Automatica</i> 149 (2023). <a href="https://doi.org/10.1016/j.automatica.2022.110840">https://doi.org/10.1016/j.automatica.2022.110840</a>.
  ieee: 'S. Peitz and K. Bieker, “On the Universal Transformation of Data-Driven Models
    to Control Systems,” <i>Automatica</i>, vol. 149, Art. no. 110840, 2023, doi:
    <a href="https://doi.org/10.1016/j.automatica.2022.110840">10.1016/j.automatica.2022.110840</a>.'
  mla: Peitz, Sebastian, and Katharina Bieker. “On the Universal Transformation of
    Data-Driven Models to Control Systems.” <i>Automatica</i>, vol. 149, 110840, Elsevier,
    2023, doi:<a href="https://doi.org/10.1016/j.automatica.2022.110840">10.1016/j.automatica.2022.110840</a>.
  short: S. Peitz, K. Bieker, Automatica 149 (2023).
date_created: 2021-02-10T07:04:15Z
date_updated: 2023-01-07T12:01:58Z
department:
- _id: '101'
- _id: '655'
doi: 10.1016/j.automatica.2022.110840
intvolume: '       149'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.sciencedirect.com/science/article/pii/S0005109822007075/pdfft?isDTMRedir=true&download=true
oa: '1'
project:
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Automatica
publication_status: published
publisher: Elsevier
status: public
title: On the Universal Transformation of Data-Driven Models to Control Systems
type: journal_article
user_id: '47427'
volume: 149
year: '2023'
...
---
_id: '49326'
abstract:
- lang: eng
  text: Many networked systems are governed by non-pairwise interactions between nodes.
    The resulting higher-order interaction structure can then be encoded by means
    of a hypernetwork. In this paper we consider dynamical systems on hypernetworks
    by defining a class of admissible maps for every such hypernetwork. We explain
    how to classify robust cluster synchronization patterns on hypernetworks by finding
    balanced partitions, and we generalize the concept of a graph fibration to the
    hypernetwork context. We also show that robust synchronization patterns are only
    fully determined by polynomial admissible maps of high order. This means that,
    unlike in dyadic networks, cluster synchronization on hypernetworks is a higher-order,
    i.e., nonlinear, effect. We give a formula, in terms of the order of the hypernetwork,
    for the degree of the polynomial admissible maps that determine robust synchronization
    patterns. We also demonstrate that this degree is optimal by investigating a class
    of examples. We conclude by demonstrating how this effect may cause remarkable
    synchrony breaking bifurcations that occur at high polynomial degree.
author:
- first_name: Sören
  full_name: von der Gracht, Sören
  id: '97359'
  last_name: von der Gracht
  orcid: 0000-0002-8054-2058
- first_name: Eddie
  full_name: Nijholt, Eddie
  last_name: Nijholt
- first_name: Bob
  full_name: Rink, Bob
  last_name: Rink
citation:
  ama: 'von der Gracht S, Nijholt E, Rink B. Hypernetworks: Cluster Synchronization
    Is a Higher-Order Effect. <i>SIAM Journal on Applied Mathematics</i>. 2023;83(6):2329-2353.
    doi:<a href="https://doi.org/10.1137/23m1561075">10.1137/23m1561075</a>'
  apa: 'von der Gracht, S., Nijholt, E., &#38; Rink, B. (2023). Hypernetworks: Cluster
    Synchronization Is a Higher-Order Effect. <i>SIAM Journal on Applied Mathematics</i>,
    <i>83</i>(6), 2329–2353. <a href="https://doi.org/10.1137/23m1561075">https://doi.org/10.1137/23m1561075</a>'
  bibtex: '@article{von der Gracht_Nijholt_Rink_2023, title={Hypernetworks: Cluster
    Synchronization Is a Higher-Order Effect}, volume={83}, DOI={<a href="https://doi.org/10.1137/23m1561075">10.1137/23m1561075</a>},
    number={6}, journal={SIAM Journal on Applied Mathematics}, publisher={Society
    for Industrial &#38; Applied Mathematics (SIAM)}, author={von der Gracht, Sören
    and Nijholt, Eddie and Rink, Bob}, year={2023}, pages={2329–2353} }'
  chicago: 'Gracht, Sören von der, Eddie Nijholt, and Bob Rink. “Hypernetworks: Cluster
    Synchronization Is a Higher-Order Effect.” <i>SIAM Journal on Applied Mathematics</i>
    83, no. 6 (2023): 2329–53. <a href="https://doi.org/10.1137/23m1561075">https://doi.org/10.1137/23m1561075</a>.'
  ieee: 'S. von der Gracht, E. Nijholt, and B. Rink, “Hypernetworks: Cluster Synchronization
    Is a Higher-Order Effect,” <i>SIAM Journal on Applied Mathematics</i>, vol. 83,
    no. 6, pp. 2329–2353, 2023, doi: <a href="https://doi.org/10.1137/23m1561075">10.1137/23m1561075</a>.'
  mla: 'von der Gracht, Sören, et al. “Hypernetworks: Cluster Synchronization Is a
    Higher-Order Effect.” <i>SIAM Journal on Applied Mathematics</i>, vol. 83, no.
    6, Society for Industrial &#38; Applied Mathematics (SIAM), 2023, pp. 2329–53,
    doi:<a href="https://doi.org/10.1137/23m1561075">10.1137/23m1561075</a>.'
  short: S. von der Gracht, E. Nijholt, B. Rink, SIAM Journal on Applied Mathematics
    83 (2023) 2329–2353.
date_created: 2023-11-29T10:50:05Z
date_updated: 2023-11-29T10:52:23Z
department:
- _id: '101'
doi: 10.1137/23m1561075
external_id:
  arxiv:
  - '2302.08974'
intvolume: '        83'
issue: '6'
keyword:
- Applied Mathematics
language:
- iso: eng
page: 2329-2353
publication: SIAM Journal on Applied Mathematics
publication_identifier:
  issn:
  - 0036-1399
  - 1095-712X
publication_status: published
publisher: Society for Industrial & Applied Mathematics (SIAM)
status: public
title: 'Hypernetworks: Cluster Synchronization Is a Higher-Order Effect'
type: journal_article
user_id: '97359'
volume: 83
year: '2023'
...
---
_id: '49372'
author:
- first_name: Jürgen
  full_name: Klüners, Jürgen
  id: '21202'
  last_name: Klüners
- first_name: Jiuya
  full_name: Wang, Jiuya
  last_name: Wang
citation:
  ama: Klüners J, Wang J. Idélic Approach in Enumerating Heisenberg Extensions. <i>La
    Matematica</i>. Published online 2023. doi:<a href="https://doi.org/10.1007/s44007-023-00067-w">10.1007/s44007-023-00067-w</a>
  apa: Klüners, J., &#38; Wang, J. (2023). Idélic Approach in Enumerating Heisenberg
    Extensions. <i>La Matematica</i>. <a href="https://doi.org/10.1007/s44007-023-00067-w">https://doi.org/10.1007/s44007-023-00067-w</a>
  bibtex: '@article{Klüners_Wang_2023, title={Idélic Approach in Enumerating Heisenberg
    Extensions}, DOI={<a href="https://doi.org/10.1007/s44007-023-00067-w">10.1007/s44007-023-00067-w</a>},
    journal={La Matematica}, publisher={Springer Science and Business Media LLC},
    author={Klüners, Jürgen and Wang, Jiuya}, year={2023} }'
  chicago: Klüners, Jürgen, and Jiuya Wang. “Idélic Approach in Enumerating Heisenberg
    Extensions.” <i>La Matematica</i>, 2023. <a href="https://doi.org/10.1007/s44007-023-00067-w">https://doi.org/10.1007/s44007-023-00067-w</a>.
  ieee: 'J. Klüners and J. Wang, “Idélic Approach in Enumerating Heisenberg Extensions,”
    <i>La Matematica</i>, 2023, doi: <a href="https://doi.org/10.1007/s44007-023-00067-w">10.1007/s44007-023-00067-w</a>.'
  mla: Klüners, Jürgen, and Jiuya Wang. “Idélic Approach in Enumerating Heisenberg
    Extensions.” <i>La Matematica</i>, Springer Science and Business Media LLC, 2023,
    doi:<a href="https://doi.org/10.1007/s44007-023-00067-w">10.1007/s44007-023-00067-w</a>.
  short: J. Klüners, J. Wang, La Matematica (2023).
date_created: 2023-12-01T09:23:59Z
date_updated: 2023-12-06T09:50:43Z
department:
- _id: '102'
doi: 10.1007/s44007-023-00067-w
language:
- iso: eng
publication: La Matematica
publication_identifier:
  issn:
  - 2730-9657
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: Idélic Approach in Enumerating Heisenberg Extensions
type: journal_article
user_id: '21202'
year: '2023'
...
---
_id: '34135'
abstract:
- lang: eng
  text: By one of the most fundamental principles in physics, a dynamical system will
    exhibit those motions which extremise an action functional. This leads to the
    formation of the Euler-Lagrange equations, which serve as a model of how the system
    will behave in time. If the dynamics exhibit additional symmetries, then the motion
    fulfils additional conservation laws, such as conservation of energy (time invariance),
    momentum (translation invariance), or angular momentum (rotational invariance).
    To learn a system representation, one could learn the discrete Euler-Lagrange
    equations, or alternatively, learn the discrete Lagrangian function Ld which defines
    them. Based on ideas from Lie group theory, in this work we introduce a framework
    to learn a discrete Lagrangian along with its symmetry group from discrete observations
    of motions and, therefore, identify conserved quantities. The learning process
    does not restrict the form of the Lagrangian, does not require velocity or momentum
    observations or predictions and incorporates a cost term which safeguards against
    unwanted solutions and against potential numerical issues in forward simulations.
    The learnt discrete quantities are related to their continuous analogues using
    variational backward error analysis and numerical results demonstrate the improvement
    such models can have both qualitatively and quantitatively even in the presence
    of noise.
author:
- first_name: Yana
  full_name: Lishkova, Yana
  last_name: Lishkova
- first_name: Paul
  full_name: Scherer, Paul
  last_name: Scherer
- first_name: Steffen
  full_name: Ridderbusch, Steffen
  last_name: Ridderbusch
- first_name: Mateja
  full_name: Jamnik, Mateja
  last_name: Jamnik
- first_name: Pietro
  full_name: Liò, Pietro
  last_name: Liò
- first_name: Sina
  full_name: Ober-Blöbaum, Sina
  id: '16494'
  last_name: Ober-Blöbaum
- first_name: Christian
  full_name: Offen, Christian
  id: '85279'
  last_name: Offen
  orcid: 0000-0002-5940-8057
citation:
  ama: 'Lishkova Y, Scherer P, Ridderbusch S, et al. Discrete Lagrangian Neural Networks
    with Automatic Symmetry Discovery. In: <i>IFAC-PapersOnLine</i>. Vol 56. Elsevier;
    2023:3203-3210. doi:<a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">10.1016/j.ifacol.2023.10.1457</a>'
  apa: Lishkova, Y., Scherer, P., Ridderbusch, S., Jamnik, M., Liò, P., Ober-Blöbaum,
    S., &#38; Offen, C. (2023). Discrete Lagrangian Neural Networks with Automatic
    Symmetry Discovery. <i>IFAC-PapersOnLine</i>, <i>56</i>(2), 3203–3210. <a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">https://doi.org/10.1016/j.ifacol.2023.10.1457</a>
  bibtex: '@inproceedings{Lishkova_Scherer_Ridderbusch_Jamnik_Liò_Ober-Blöbaum_Offen_2023,
    title={Discrete Lagrangian Neural Networks with Automatic Symmetry Discovery},
    volume={56}, DOI={<a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">10.1016/j.ifacol.2023.10.1457</a>},
    number={2}, booktitle={IFAC-PapersOnLine}, publisher={Elsevier}, author={Lishkova,
    Yana and Scherer, Paul and Ridderbusch, Steffen and Jamnik, Mateja and Liò, Pietro
    and Ober-Blöbaum, Sina and Offen, Christian}, year={2023}, pages={3203–3210} }'
  chicago: Lishkova, Yana, Paul Scherer, Steffen Ridderbusch, Mateja Jamnik, Pietro
    Liò, Sina Ober-Blöbaum, and Christian Offen. “Discrete Lagrangian Neural Networks
    with Automatic Symmetry Discovery.” In <i>IFAC-PapersOnLine</i>, 56:3203–10. Elsevier,
    2023. <a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">https://doi.org/10.1016/j.ifacol.2023.10.1457</a>.
  ieee: 'Y. Lishkova <i>et al.</i>, “Discrete Lagrangian Neural Networks with Automatic
    Symmetry Discovery,” in <i>IFAC-PapersOnLine</i>,  Yokohama, Japan, 2023, vol.
    56, no. 2, pp. 3203–3210, doi: <a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">10.1016/j.ifacol.2023.10.1457</a>.'
  mla: Lishkova, Yana, et al. “Discrete Lagrangian Neural Networks with Automatic
    Symmetry Discovery.” <i>IFAC-PapersOnLine</i>, vol. 56, no. 2, Elsevier, 2023,
    pp. 3203–10, doi:<a href="https://doi.org/10.1016/j.ifacol.2023.10.1457">10.1016/j.ifacol.2023.10.1457</a>.
  short: 'Y. Lishkova, P. Scherer, S. Ridderbusch, M. Jamnik, P. Liò, S. Ober-Blöbaum,
    C. Offen, in: IFAC-PapersOnLine, Elsevier, 2023, pp. 3203–3210.'
conference:
  end_date: 2023-07-14
  location: ' Yokohama, Japan'
  name: The 22nd World Congress of the International Federation of Automatic Control
  start_date: 2023-07-09
date_created: 2022-11-23T08:17:10Z
date_updated: 2023-12-29T14:26:00Z
ddc:
- '510'
department:
- _id: '636'
doi: 10.1016/j.ifacol.2023.10.1457
external_id:
  arxiv:
  - '2211.10830'
file:
- access_level: open_access
  content_type: application/pdf
  creator: coffen
  date_created: 2023-04-17T08:05:55Z
  date_updated: 2023-04-17T08:05:55Z
  description: |-
    By one of the most fundamental principles in physics, a dynamical system will
    exhibit those motions which extremise an action functional. This leads to the formation of
    the Euler-Lagrange equations, which serve as a model of how the system will behave in time.
    If the dynamics exhibit additional symmetries, then the motion fulfils additional conservation
    laws, such as conservation of energy (time invariance), momentum (translation invariance), or
    angular momentum (rotational invariance). To learn a system representation, one could learn
    the discrete Euler-Lagrange equations, or alternatively, learn the discrete Lagrangian function
    Ld which defines them. Based on ideas from Lie group theory, we introduce a framework to learn
    a discrete Lagrangian along with its symmetry group from discrete observations of motions and,
    therefore, identify conserved quantities. The learning process does not restrict the form of the
    Lagrangian, does not require velocity or momentum observations or predictions and incorporates
    a cost term which safeguards against unwanted solutions and against potential numerical issues
    in forward simulations. The learnt discrete quantities are related to their continuous analogues
    using variational backward error analysis and numerical results demonstrate the improvement
    such models can have both qualitatively and quantitatively even in the presence of noise.
  file_id: '44037'
  file_name: LNN_project.pdf
  file_size: 576115
  relation: main_file
  title: Discrete Lagrangian Neural Networks with Automatic Symmetry Discovery
file_date_updated: 2023-04-17T08:05:55Z
has_accepted_license: '1'
intvolume: '        56'
issue: '2'
language:
- iso: eng
main_file_link:
- url: https://www.sciencedirect.com/science/article/pii/S2405896323018657
oa: '1'
page: 3203-3210
publication: IFAC-PapersOnLine
publication_status: published
publisher: Elsevier
quality_controlled: '1'
related_material:
  link:
  - description: GitHub
    relation: software
    url: https://github.com/yanalish/SymDLNN
status: public
title: Discrete Lagrangian Neural Networks with Automatic Symmetry Discovery
type: conference
user_id: '85279'
volume: 56
year: '2023'
...
---
_id: '50298'
abstract:
- lang: eng
  text: A finite classical polar space of rank $n$ consists of the totally isotropic
    subspaces of a finite vector space equipped with a nondegenerate form such that
    $n$ is the maximal dimension of such a subspace. A $t$-Steiner system in a finite
    classical polar space of rank $n$ is a collection $Y$ of totally isotropic $n$-spaces
    such that each totally isotropic $t$-space is contained in exactly one member
    of $Y$. Nontrivial examples are known only for $t=1$ and $t=n-1$. We give an almost
    complete classification of such $t$-Steiner systems, showing that such objects
    can only exist in some corner cases. This classification result arises from a
    more general result on packings in polar spaces.
author:
- first_name: Kai-Uwe
  full_name: Schmidt, Kai-Uwe
  last_name: Schmidt
- first_name: Charlene
  full_name: Weiß, Charlene
  id: '70420'
  last_name: Weiß
citation:
  ama: Schmidt K-U, Weiß C. Packings and Steiner systems in polar spaces. <i>Combinatorial
    Theory</i>. 2023;3(1). doi:<a href="https://doi.org/10.5070/c63160424">10.5070/c63160424</a>
  apa: Schmidt, K.-U., &#38; Weiß, C. (2023). Packings and Steiner systems in polar
    spaces. <i>Combinatorial Theory</i>, <i>3</i>(1). <a href="https://doi.org/10.5070/c63160424">https://doi.org/10.5070/c63160424</a>
  bibtex: '@article{Schmidt_Weiß_2023, title={Packings and Steiner systems in polar
    spaces}, volume={3}, DOI={<a href="https://doi.org/10.5070/c63160424">10.5070/c63160424</a>},
    number={1}, journal={Combinatorial Theory}, author={Schmidt, Kai-Uwe and Weiß,
    Charlene}, year={2023} }'
  chicago: Schmidt, Kai-Uwe, and Charlene Weiß. “Packings and Steiner Systems in Polar
    Spaces.” <i>Combinatorial Theory</i> 3, no. 1 (2023). <a href="https://doi.org/10.5070/c63160424">https://doi.org/10.5070/c63160424</a>.
  ieee: 'K.-U. Schmidt and C. Weiß, “Packings and Steiner systems in polar spaces,”
    <i>Combinatorial Theory</i>, vol. 3, no. 1, 2023, doi: <a href="https://doi.org/10.5070/c63160424">10.5070/c63160424</a>.'
  mla: Schmidt, Kai-Uwe, and Charlene Weiß. “Packings and Steiner Systems in Polar
    Spaces.” <i>Combinatorial Theory</i>, vol. 3, no. 1, 2023, doi:<a href="https://doi.org/10.5070/c63160424">10.5070/c63160424</a>.
  short: K.-U. Schmidt, C. Weiß, Combinatorial Theory 3 (2023).
date_created: 2024-01-08T14:33:54Z
date_updated: 2024-01-08T14:39:20Z
department:
- _id: '100'
doi: 10.5070/c63160424
intvolume: '         3'
issue: '1'
language:
- iso: eng
publication: Combinatorial Theory
publication_status: published
status: public
title: Packings and Steiner systems in polar spaces
type: journal_article
user_id: '70420'
volume: 3
year: '2023'
...
---
_id: '50297'
abstract:
- lang: eng
  text: We show that there exist ordered orthogonal arrays, whose sizes deviate from
    the Rao bound by a factor that is polynomial in the parameters of the ordered
    orthogonal array. The proof is nonconstructive and based on a probabilistic method
    due to Kuperberg, Lovett and Peled.
author:
- first_name: Kai‐Uwe
  full_name: Schmidt, Kai‐Uwe
  last_name: Schmidt
- first_name: Charlene
  full_name: Weiß, Charlene
  id: '70420'
  last_name: Weiß
citation:
  ama: Schmidt K, Weiß C. Existence of small ordered orthogonal arrays. <i>Journal
    of Combinatorial Designs</i>. 2023;31(9):422-431. doi:<a href="https://doi.org/10.1002/jcd.21903">10.1002/jcd.21903</a>
  apa: Schmidt, K., &#38; Weiß, C. (2023). Existence of small ordered orthogonal arrays.
    <i>Journal of Combinatorial Designs</i>, <i>31</i>(9), 422–431. <a href="https://doi.org/10.1002/jcd.21903">https://doi.org/10.1002/jcd.21903</a>
  bibtex: '@article{Schmidt_Weiß_2023, title={Existence of small ordered orthogonal
    arrays}, volume={31}, DOI={<a href="https://doi.org/10.1002/jcd.21903">10.1002/jcd.21903</a>},
    number={9}, journal={Journal of Combinatorial Designs}, publisher={Wiley}, author={Schmidt,
    Kai‐Uwe and Weiß, Charlene}, year={2023}, pages={422–431} }'
  chicago: 'Schmidt, Kai‐Uwe, and Charlene Weiß. “Existence of Small Ordered Orthogonal
    Arrays.” <i>Journal of Combinatorial Designs</i> 31, no. 9 (2023): 422–31. <a
    href="https://doi.org/10.1002/jcd.21903">https://doi.org/10.1002/jcd.21903</a>.'
  ieee: 'K. Schmidt and C. Weiß, “Existence of small ordered orthogonal arrays,” <i>Journal
    of Combinatorial Designs</i>, vol. 31, no. 9, pp. 422–431, 2023, doi: <a href="https://doi.org/10.1002/jcd.21903">10.1002/jcd.21903</a>.'
  mla: Schmidt, Kai‐Uwe, and Charlene Weiß. “Existence of Small Ordered Orthogonal
    Arrays.” <i>Journal of Combinatorial Designs</i>, vol. 31, no. 9, Wiley, 2023,
    pp. 422–31, doi:<a href="https://doi.org/10.1002/jcd.21903">10.1002/jcd.21903</a>.
  short: K. Schmidt, C. Weiß, Journal of Combinatorial Designs 31 (2023) 422–431.
date_created: 2024-01-08T14:25:28Z
date_updated: 2024-01-08T14:38:53Z
department:
- _id: '100'
doi: 10.1002/jcd.21903
intvolume: '        31'
issue: '9'
language:
- iso: eng
page: 422-431
publication: Journal of Combinatorial Designs
publication_status: published
publisher: Wiley
status: public
title: Existence of small ordered orthogonal arrays
type: journal_article
user_id: '70420'
volume: 31
year: '2023'
...
---
_id: '50300'
abstract:
- lang: eng
  text: Digital communications relies heavily on the usage of different types of codes.
    Prominent codes nowadays are rank-metric codes and subspace codes - the q-analogs
    of binary codes and binary codes with constant weight. All these codes can be
    viewed as subsets of classical association schemes. A central coding-theoretic
    problem is to derive upper bounds for the size of codes. This thesis investigates
    Delsartes powerful linear program whose optimum is precisely such a bound for
    codes in association schemes. The linear programs for binary codes and binary
    constant-weight codes have been extensively studied since the 1970s, but their
    optimum is still unknown. We determine in a unified way the optimum of the linear
    program in several ordinary q-analogs as well as in their affine counterparts.
    In particular, bounds and constructions for codes in polar spaces are established,
    where the bounds are sharp up to a constant factor in many cases. Moreover, based
    on these results, an almost complete classification of Steiner systems in polar
    spaces is provided by showing that they could only exist in some corner cases.
author:
- first_name: Charlene
  full_name: Weiß, Charlene
  id: '70420'
  last_name: Weiß
citation:
  ama: Weiß C. <i>Linear Programming Bounds in Classical Association Schemes</i>.;
    2023. doi:<a href="https://doi.org/10.17619/UNIPB/1-1672">10.17619/UNIPB/1-1672</a>
  apa: Weiß, C. (2023). <i>Linear programming bounds in classical association schemes</i>.
    <a href="https://doi.org/10.17619/UNIPB/1-1672">https://doi.org/10.17619/UNIPB/1-1672</a>
  bibtex: '@book{Weiß_2023, title={Linear programming bounds in classical association
    schemes}, DOI={<a href="https://doi.org/10.17619/UNIPB/1-1672">10.17619/UNIPB/1-1672</a>},
    author={Weiß, Charlene}, year={2023} }'
  chicago: Weiß, Charlene. <i>Linear Programming Bounds in Classical Association Schemes</i>,
    2023. <a href="https://doi.org/10.17619/UNIPB/1-1672">https://doi.org/10.17619/UNIPB/1-1672</a>.
  ieee: C. Weiß, <i>Linear programming bounds in classical association schemes</i>.
    2023.
  mla: Weiß, Charlene. <i>Linear Programming Bounds in Classical Association Schemes</i>.
    2023, doi:<a href="https://doi.org/10.17619/UNIPB/1-1672">10.17619/UNIPB/1-1672</a>.
  short: C. Weiß, Linear Programming Bounds in Classical Association Schemes, 2023.
date_created: 2024-01-08T14:42:12Z
date_updated: 2024-01-08T14:46:14Z
department:
- _id: '100'
doi: 10.17619/UNIPB/1-1672
language:
- iso: eng
status: public
title: Linear programming bounds in classical association schemes
type: dissertation
user_id: '70420'
year: '2023'
...
---
_id: '51351'
author:
- first_name: Eckhard
  full_name: Steffen, Eckhard
  id: '15548'
  last_name: Steffen
  orcid: 0000-0002-9808-7401
- first_name: Isaak Hieronymus
  full_name: Wolf, Isaak Hieronymus
  id: '88145'
  last_name: Wolf
citation:
  ama: Steffen E, Wolf IH. Bounds for the chromatic index of signed multigraphs. <i>Discrete
    Applied Mathematics</i>. 2023;337:185-189. doi:<a href="https://doi.org/10.1016/j.dam.2023.05.008">10.1016/j.dam.2023.05.008</a>
  apa: Steffen, E., &#38; Wolf, I. H. (2023). Bounds for the chromatic index of signed
    multigraphs. <i>Discrete Applied Mathematics</i>, <i>337</i>, 185–189. <a href="https://doi.org/10.1016/j.dam.2023.05.008">https://doi.org/10.1016/j.dam.2023.05.008</a>
  bibtex: '@article{Steffen_Wolf_2023, title={Bounds for the chromatic index of signed
    multigraphs}, volume={337}, DOI={<a href="https://doi.org/10.1016/j.dam.2023.05.008">10.1016/j.dam.2023.05.008</a>},
    journal={Discrete Applied Mathematics}, publisher={Elsevier BV}, author={Steffen,
    Eckhard and Wolf, Isaak Hieronymus}, year={2023}, pages={185–189} }'
  chicago: 'Steffen, Eckhard, and Isaak Hieronymus Wolf. “Bounds for the Chromatic
    Index of Signed Multigraphs.” <i>Discrete Applied Mathematics</i> 337 (2023):
    185–89. <a href="https://doi.org/10.1016/j.dam.2023.05.008">https://doi.org/10.1016/j.dam.2023.05.008</a>.'
  ieee: 'E. Steffen and I. H. Wolf, “Bounds for the chromatic index of signed multigraphs,”
    <i>Discrete Applied Mathematics</i>, vol. 337, pp. 185–189, 2023, doi: <a href="https://doi.org/10.1016/j.dam.2023.05.008">10.1016/j.dam.2023.05.008</a>.'
  mla: Steffen, Eckhard, and Isaak Hieronymus Wolf. “Bounds for the Chromatic Index
    of Signed Multigraphs.” <i>Discrete Applied Mathematics</i>, vol. 337, Elsevier
    BV, 2023, pp. 185–89, doi:<a href="https://doi.org/10.1016/j.dam.2023.05.008">10.1016/j.dam.2023.05.008</a>.
  short: E. Steffen, I.H. Wolf, Discrete Applied Mathematics 337 (2023) 185–189.
date_created: 2024-02-14T17:33:29Z
date_updated: 2024-02-14T17:33:59Z
department:
- _id: '542'
doi: 10.1016/j.dam.2023.05.008
intvolume: '       337'
keyword:
- Applied Mathematics
- Discrete Mathematics and Combinatorics
language:
- iso: eng
page: 185-189
publication: Discrete Applied Mathematics
publication_identifier:
  issn:
  - 0166-218X
publication_status: published
publisher: Elsevier BV
status: public
title: Bounds for the chromatic index of signed multigraphs
type: journal_article
user_id: '15540'
volume: 337
year: '2023'
...
---
_id: '45190'
author:
- first_name: Chiara
  full_name: Cappello, Chiara
  id: '72874'
  last_name: Cappello
- first_name: Eckhard
  full_name: Steffen, Eckhard
  id: '15548'
  last_name: Steffen
  orcid: 0000-0002-9808-7401
citation:
  ama: 'Cappello C, Steffen E. Graph-Theoretical Models for the Analysis and Design
    of Socio-Technical Networks. In: <i>The Digital Twin of Humans</i>. Springer International
    Publishing; 2023:93--110. doi:<a href="https://doi.org/10.1007/978-3-031-26104-6_5">10.1007/978-3-031-26104-6_5</a>'
  apa: Cappello, C., &#38; Steffen, E. (2023). Graph-Theoretical Models for the Analysis
    and Design of Socio-Technical Networks. In <i>The Digital Twin of Humans</i> (pp.
    93--110). Springer International Publishing. <a href="https://doi.org/10.1007/978-3-031-26104-6_5">https://doi.org/10.1007/978-3-031-26104-6_5</a>
  bibtex: '@inbook{Cappello_Steffen_2023, place={Cham}, title={Graph-Theoretical Models
    for the Analysis and Design of Socio-Technical Networks}, DOI={<a href="https://doi.org/10.1007/978-3-031-26104-6_5">10.1007/978-3-031-26104-6_5</a>},
    booktitle={The Digital Twin of Humans}, publisher={Springer International Publishing},
    author={Cappello, Chiara and Steffen, Eckhard}, year={2023}, pages={93--110} }'
  chicago: 'Cappello, Chiara, and Eckhard Steffen. “Graph-Theoretical Models for the
    Analysis and Design of Socio-Technical Networks.” In <i>The Digital Twin of Humans</i>,
    93--110. Cham: Springer International Publishing, 2023. <a href="https://doi.org/10.1007/978-3-031-26104-6_5">https://doi.org/10.1007/978-3-031-26104-6_5</a>.'
  ieee: 'C. Cappello and E. Steffen, “Graph-Theoretical Models for the Analysis and
    Design of Socio-Technical Networks,” in <i>The Digital Twin of Humans</i>, Cham:
    Springer International Publishing, 2023, pp. 93--110.'
  mla: Cappello, Chiara, and Eckhard Steffen. “Graph-Theoretical Models for the Analysis
    and Design of Socio-Technical Networks.” <i>The Digital Twin of Humans</i>, Springer
    International Publishing, 2023, pp. 93--110, doi:<a href="https://doi.org/10.1007/978-3-031-26104-6_5">10.1007/978-3-031-26104-6_5</a>.
  short: 'C. Cappello, E. Steffen, in: The Digital Twin of Humans, Springer International
    Publishing, Cham, 2023, pp. 93--110.'
date_created: 2023-05-22T10:22:21Z
date_updated: 2024-02-16T07:42:38Z
department:
- _id: '542'
doi: 10.1007/978-3-031-26104-6_5
language:
- iso: eng
page: 93--110
place: Cham
publication: The Digital Twin of Humans
publication_identifier:
  isbn:
  - '9783031261039'
  - '9783031261046'
publication_status: published
publisher: Springer International Publishing
status: public
title: Graph-Theoretical Models for the Analysis and Design of Socio-Technical Networks
type: book_chapter
user_id: '15540'
year: '2023'
...
---
_id: '51357'
article_number: '113457'
author:
- first_name: Eckhard
  full_name: Steffen, Eckhard
  id: '15548'
  last_name: Steffen
  orcid: 0000-0002-9808-7401
- first_name: Isaak Hieronymus
  full_name: Wolf, Isaak Hieronymus
  id: '88145'
  last_name: Wolf
citation:
  ama: Steffen E, Wolf IH. Rotation r-graphs. <i>Discrete Mathematics</i>. Published
    online 2023. doi:<a href="https://doi.org/10.1016/j.disc.2023.113457">10.1016/j.disc.2023.113457</a>
  apa: Steffen, E., &#38; Wolf, I. H. (2023). Rotation r-graphs. <i>Discrete Mathematics</i>,
    Article 113457. <a href="https://doi.org/10.1016/j.disc.2023.113457">https://doi.org/10.1016/j.disc.2023.113457</a>
  bibtex: '@article{Steffen_Wolf_2023, title={Rotation r-graphs}, DOI={<a href="https://doi.org/10.1016/j.disc.2023.113457">10.1016/j.disc.2023.113457</a>},
    number={113457}, journal={Discrete Mathematics}, publisher={Elsevier BV}, author={Steffen,
    Eckhard and Wolf, Isaak Hieronymus}, year={2023} }'
  chicago: Steffen, Eckhard, and Isaak Hieronymus Wolf. “Rotation R-Graphs.” <i>Discrete
    Mathematics</i>, 2023. <a href="https://doi.org/10.1016/j.disc.2023.113457">https://doi.org/10.1016/j.disc.2023.113457</a>.
  ieee: 'E. Steffen and I. H. Wolf, “Rotation r-graphs,” <i>Discrete Mathematics</i>,
    Art. no. 113457, 2023, doi: <a href="https://doi.org/10.1016/j.disc.2023.113457">10.1016/j.disc.2023.113457</a>.'
  mla: Steffen, Eckhard, and Isaak Hieronymus Wolf. “Rotation R-Graphs.” <i>Discrete
    Mathematics</i>, 113457, Elsevier BV, 2023, doi:<a href="https://doi.org/10.1016/j.disc.2023.113457">10.1016/j.disc.2023.113457</a>.
  short: E. Steffen, I.H. Wolf, Discrete Mathematics (2023).
date_created: 2024-02-16T08:44:50Z
date_updated: 2024-02-16T08:45:10Z
department:
- _id: '542'
doi: 10.1016/j.disc.2023.113457
keyword:
- Discrete Mathematics and Combinatorics
- Theoretical Computer Science
language:
- iso: eng
publication: Discrete Mathematics
publication_identifier:
  issn:
  - 0012-365X
publication_status: published
publisher: Elsevier BV
status: public
title: Rotation r-graphs
type: journal_article
user_id: '15540'
year: '2023'
...
---
_id: '46578'
abstract:
- lang: eng
  text: 'Multiobjective optimization plays an increasingly important role in modern
    applications, where several criteria are often of equal importance. The task in
    multiobjective optimization and multiobjective optimal control is therefore to
    compute the set of optimal compromises (the Pareto set) between the conflicting
    objectives. The advances in algorithms and the increasing interest in Pareto-optimal
    solutions have led to a wide range of new applications related to optimal and
    feedback control - potentially with non-smoothness both on the level of the objectives
    or in the system dynamics. This results in new challenges such as dealing with
    expensive models (e.g., governed by partial differential equations (PDEs)) and
    developing dedicated algorithms handling the non-smoothness. Since in contrast
    to single-objective optimization, the Pareto set generally consists of an infinite
    number of solutions, the computational effort can quickly become challenging,
    which is particularly problematic when the objectives are costly to evaluate or
    when a solution has to be presented very quickly. This article gives an overview
    of recent developments in the field of multiobjective optimization of non-smooth
    PDE-constrained problems. In particular we report on the advances achieved within
    Project 2 "Multiobjective Optimization of Non-Smooth PDE-Constrained Problems
    - Switches, State Constraints and Model Order Reduction" of the DFG Priority Programm
    1962 "Non-smooth and Complementarity-based Distributed Parameter Systems: Simulation
    and Hierarchical Optimization".'
author:
- first_name: Marco
  full_name: Bernreuther, Marco
  last_name: Bernreuther
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
- first_name: Georg
  full_name: Müller, Georg
  last_name: Müller
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
- first_name: Konstantin
  full_name: Sonntag, Konstantin
  id: '56399'
  last_name: Sonntag
  orcid: https://orcid.org/0000-0003-3384-3496
- first_name: Stefan
  full_name: Volkwein, Stefan
  last_name: Volkwein
citation:
  ama: Bernreuther M, Dellnitz M, Gebken B, et al. Multiobjective Optimization of
    Non-Smooth PDE-Constrained Problems. <i>arXiv:230801113</i>. Published online
    2023.
  apa: Bernreuther, M., Dellnitz, M., Gebken, B., Müller, G., Peitz, S., Sonntag,
    K., &#38; Volkwein, S. (2023). Multiobjective Optimization of Non-Smooth PDE-Constrained
    Problems. In <i>arXiv:2308.01113</i>.
  bibtex: '@article{Bernreuther_Dellnitz_Gebken_Müller_Peitz_Sonntag_Volkwein_2023,
    title={Multiobjective Optimization of Non-Smooth PDE-Constrained Problems}, journal={arXiv:2308.01113},
    author={Bernreuther, Marco and Dellnitz, Michael and Gebken, Bennet and Müller,
    Georg and Peitz, Sebastian and Sonntag, Konstantin and Volkwein, Stefan}, year={2023}
    }'
  chicago: Bernreuther, Marco, Michael Dellnitz, Bennet Gebken, Georg Müller, Sebastian
    Peitz, Konstantin Sonntag, and Stefan Volkwein. “Multiobjective Optimization of
    Non-Smooth PDE-Constrained Problems.” <i>ArXiv:2308.01113</i>, 2023.
  ieee: M. Bernreuther <i>et al.</i>, “Multiobjective Optimization of Non-Smooth PDE-Constrained
    Problems,” <i>arXiv:2308.01113</i>. 2023.
  mla: Bernreuther, Marco, et al. “Multiobjective Optimization of Non-Smooth PDE-Constrained
    Problems.” <i>ArXiv:2308.01113</i>, 2023.
  short: M. Bernreuther, M. Dellnitz, B. Gebken, G. Müller, S. Peitz, K. Sonntag,
    S. Volkwein, ArXiv:2308.01113 (2023).
date_created: 2023-08-21T05:50:12Z
date_updated: 2024-02-21T12:22:20Z
department:
- _id: '655'
- _id: '101'
external_id:
  arxiv:
  - '2308.01113'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/pdf/2308.01113
oa: '1'
publication: arXiv:2308.01113
status: public
title: Multiobjective Optimization of Non-Smooth PDE-Constrained Problems
type: preprint
user_id: '47427'
year: '2023'
...
---
_id: '45191'
alternative_title:
- An Interdisciplinary Concept of Digital Working Environments in Industry 4.0
citation:
  ama: Gräßler I, Maier GW, Steffen E, Roesmann D, eds. <i>The Digital Twin of Humans</i>.
    Springer International Publishing; 2023. doi:<a href="https://doi.org/10.1007/978-3-031-26104-6">10.1007/978-3-031-26104-6</a>
  apa: Gräßler, I., Maier, G. W., Steffen, E., &#38; Roesmann, D. (Eds.). (2023).
    <i>The Digital Twin of Humans</i>. Springer International Publishing. <a href="https://doi.org/10.1007/978-3-031-26104-6">https://doi.org/10.1007/978-3-031-26104-6</a>
  bibtex: '@book{Gräßler_Maier_Steffen_Roesmann_2023, place={Cham}, title={The Digital
    Twin of Humans}, DOI={<a href="https://doi.org/10.1007/978-3-031-26104-6">10.1007/978-3-031-26104-6</a>},
    publisher={Springer International Publishing}, year={2023} }'
  chicago: 'Gräßler, Iris, Günter W. Maier, Eckhard Steffen, and Daniel Roesmann,
    eds. <i>The Digital Twin of Humans</i>. Cham: Springer International Publishing,
    2023. <a href="https://doi.org/10.1007/978-3-031-26104-6">https://doi.org/10.1007/978-3-031-26104-6</a>.'
  ieee: 'I. Gräßler, G. W. Maier, E. Steffen, and D. Roesmann, Eds., <i>The Digital
    Twin of Humans</i>. Cham: Springer International Publishing, 2023.'
  mla: Gräßler, Iris, et al., editors. <i>The Digital Twin of Humans</i>. Springer
    International Publishing, 2023, doi:<a href="https://doi.org/10.1007/978-3-031-26104-6">10.1007/978-3-031-26104-6</a>.
  short: I. Gräßler, G.W. Maier, E. Steffen, D. Roesmann, eds., The Digital Twin of
    Humans, Springer International Publishing, Cham, 2023.
date_created: 2023-05-22T10:24:10Z
date_updated: 2024-03-25T09:07:55Z
department:
- _id: '542'
- _id: '152'
doi: 10.1007/978-3-031-26104-6
editor:
- first_name: Iris
  full_name: Gräßler, Iris
  id: '47565'
  last_name: Gräßler
  orcid: 0000-0001-5765-971X
- first_name: Günter W.
  full_name: Maier, Günter W.
  last_name: Maier
- first_name: Eckhard
  full_name: Steffen, Eckhard
  id: '15548'
  last_name: Steffen
  orcid: 0000-0002-9808-7401
- first_name: Daniel
  full_name: Roesmann, Daniel
  id: '54680'
  last_name: Roesmann
language:
- iso: eng
place: Cham
publication_identifier:
  isbn:
  - '9783031261039'
  - '9783031261046'
publication_status: published
publisher: Springer International Publishing
quality_controlled: '1'
status: public
title: The Digital Twin of Humans
type: book_editor
user_id: '5905'
year: '2023'
...
