---
_id: '61017'
abstract:
- lang: eng
text: Selecting tasks is a typical job in everyday teaching that requires teachers
to have content-specific expertise, including categories to think about and perceive
conceptual understanding. This contribution investigates the activation of prospective
teachers’ categories when solving tasks on the scalar product and evaluating their
relevance for teaching in upper secondary school. To further investigate, whether
input on content-related aspects could be helpful to promote a professional justification
for the selection of tasks, two groups with and without input are to be differentiated.
Different ways of dealing with underlying concept elements and evaluating the
relevance of tasks are discussed by examples.
author:
- first_name: Janine
full_name: Herrmann, Janine
id: '64060'
last_name: Herrmann
citation:
ama: 'Herrmann J. Which categories do prospective teachers apply when selecting
tasks for the scalar product? In: Cornejo C, Felmer P, Gómez DM, et al., eds.
Proceedings of the 48th Conference of the International Group for the Psychology
of Mathematics Education. Vol 1. ; 2025.'
apa: Herrmann, J. (2025). Which categories do prospective teachers apply when selecting
tasks for the scalar product? In C. Cornejo, P. Felmer, D. M. Gómez, P. Dartnell,
P. Araya, A. Peri, & V. Randolph (Eds.), Proceedings of the 48th Conference
of the International Group for the Psychology of Mathematics Education (Vol.
1).
bibtex: '@inproceedings{Herrmann_2025, title={Which categories do prospective teachers
apply when selecting tasks for the scalar product?}, volume={1}, booktitle={Proceedings
of the 48th Conference of the International Group for the Psychology of Mathematics
Education}, author={Herrmann, Janine}, editor={Cornejo, Claudia and Felmer, Patricio
and Gómez, David M. and Dartnell, Pablo and Araya, Paulina and Peri, Armando and
Randolph, Valeria }, year={2025} }'
chicago: Herrmann, Janine. “Which Categories Do Prospective Teachers Apply When
Selecting Tasks for the Scalar Product?” In Proceedings of the 48th Conference
of the International Group for the Psychology of Mathematics Education, edited
by Claudia Cornejo, Patricio Felmer, David M. Gómez, Pablo Dartnell, Paulina Araya,
Armando Peri, and Valeria Randolph, Vol. 1, 2025.
ieee: J. Herrmann, “Which categories do prospective teachers apply when selecting
tasks for the scalar product?,” in Proceedings of the 48th Conference of the
International Group for the Psychology of Mathematics Education, Santiago
de Chile, 2025, vol. 1.
mla: Herrmann, Janine. “Which Categories Do Prospective Teachers Apply When Selecting
Tasks for the Scalar Product?” Proceedings of the 48th Conference of the International
Group for the Psychology of Mathematics Education, edited by Claudia Cornejo
et al., vol. 1, 2025.
short: 'J. Herrmann, in: C. Cornejo, P. Felmer, D.M. Gómez, P. Dartnell, P. Araya,
A. Peri, V. Randolph (Eds.), Proceedings of the 48th Conference of the International
Group for the Psychology of Mathematics Education, 2025.'
conference:
end_date: 2025-08-02
location: Santiago de Chile
name: 48th PME Conference
start_date: 2025-07-28
date_created: 2025-08-26T08:35:10Z
date_updated: 2026-02-16T07:54:31Z
ddc:
- '510'
editor:
- first_name: Claudia
full_name: Cornejo, Claudia
last_name: Cornejo
- first_name: Patricio
full_name: Felmer, Patricio
last_name: Felmer
- first_name: David M.
full_name: Gómez, David M.
last_name: Gómez
- first_name: Pablo
full_name: Dartnell, Pablo
last_name: Dartnell
- first_name: Paulina
full_name: Araya, Paulina
last_name: Araya
- first_name: Armando
full_name: Peri, Armando
last_name: Peri
- first_name: 'Valeria '
full_name: 'Randolph, Valeria '
last_name: Randolph
file:
- access_level: closed
content_type: application/pdf
creator: herrmann
date_created: 2025-08-26T08:32:39Z
date_updated: 2025-08-26T08:32:39Z
file_id: '61018'
file_name: RR_Herrmann.pdf
file_size: 408502
relation: main_file
success: 1
file_date_updated: 2025-08-26T08:32:39Z
has_accepted_license: '1'
intvolume: ' 1'
keyword:
- Teacher expertise
- noticing
- analytical vectorial geometry
language:
- iso: eng
main_file_link:
- url: https://www.igpme.org/wp-content/uploads/2025/07/PME48_ResearchReports_E-ISSN_2790-3648.zip
publication: Proceedings of the 48th Conference of the International Group for the
Psychology of Mathematics Education
publication_identifier:
unknown:
- 2790-3648
quality_controlled: '1'
status: public
title: Which categories do prospective teachers apply when selecting tasks for the
scalar product?
type: conference
user_id: '64060'
volume: 1
year: '2025'
...
---
_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.). Machine learning of discrete field theories with guaranteed
convergence and uncertainty quantification.
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. Machine Learning of Discrete Field Theories with Guaranteed
Convergence and Uncertainty Quantification.
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
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: '31849'
author:
- first_name: Max
full_name: Hoffmann, Max
id: '32202'
last_name: Hoffmann
orcid: 0000-0002-6964-7123
- first_name: Rolf
full_name: Biehler, Rolf
id: '16274'
last_name: Biehler
citation:
ama: 'Hoffmann M, Biehler R. Student Teachers ’ Knowledge of Congruence before a
University Course on Geometry. In: Trigueros M, Barquero B, Hochmuth R, Peters
J, eds. Proceedings of the Fourth Conference of the International Network for
Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022).
University of Hannover and INDRUM.; 2023.'
apa: Hoffmann, M., & Biehler, R. (2023). Student Teachers ’ Knowledge of Congruence
before a University Course on Geometry. In M. Trigueros, B. Barquero, R. Hochmuth,
& J. Peters (Eds.), Proceedings of the Fourth Conference of the International
Network for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October
2022). University of Hannover and INDRUM.
bibtex: '@inproceedings{Hoffmann_Biehler_2023, place={Hannover}, title={Student
Teachers ’ Knowledge of Congruence before a University Course on Geometry}, booktitle={Proceedings
of the Fourth Conference of the International Network for Didactic Research in
University Mathematics (INDRUM 2022, 19-22 October 2022)}, publisher={University
of Hannover and INDRUM.}, author={Hoffmann, Max and Biehler, Rolf}, editor={Trigueros,
Marı́a and Barquero, Berta and Hochmuth, Reinhard and Peters, Jana}, year={2023}
}'
chicago: 'Hoffmann, Max, and Rolf Biehler. “Student Teachers ’ Knowledge of Congruence
before a University Course on Geometry.” In Proceedings of the Fourth Conference
of the International Network for Didactic Research in University Mathematics (INDRUM
2022, 19-22 October 2022), edited by Marı́a Trigueros, Berta Barquero, Reinhard
Hochmuth, and Jana Peters. Hannover: University of Hannover and INDRUM., 2023.'
ieee: M. Hoffmann and R. Biehler, “Student Teachers ’ Knowledge of Congruence before
a University Course on Geometry,” in Proceedings of the Fourth Conference of
the International Network for Didactic Research in University Mathematics (INDRUM
2022, 19-22 October 2022), 2023.
mla: Hoffmann, Max, and Rolf Biehler. “Student Teachers ’ Knowledge of Congruence
before a University Course on Geometry.” Proceedings of the Fourth Conference
of the International Network for Didactic Research in University Mathematics (INDRUM
2022, 19-22 October 2022), edited by Marı́a Trigueros et al., University of
Hannover and INDRUM., 2023.
short: 'M. Hoffmann, R. Biehler, in: M. Trigueros, B. Barquero, R. Hochmuth, J.
Peters (Eds.), Proceedings of the Fourth Conference of the International Network
for Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022),
University of Hannover and INDRUM., Hannover, 2023.'
date_created: 2022-06-12T11:07:34Z
date_updated: 2023-03-25T10:11:35Z
ddc:
- '370'
- '510'
department:
- _id: '97'
editor:
- first_name: Marı́a
full_name: Trigueros, Marı́a
last_name: Trigueros
- first_name: Berta
full_name: Barquero, Berta
last_name: Barquero
- first_name: Reinhard
full_name: Hochmuth, Reinhard
last_name: Hochmuth
- first_name: Jana
full_name: Peters, Jana
last_name: Peters
file:
- access_level: closed
content_type: application/pdf
creator: maxh
date_created: 2023-03-25T10:01:03Z
date_updated: 2023-03-25T10:01:03Z
file_id: '43096'
file_name: HoffmannBiehler2022_indrum_congruence.pdf
file_size: 201942
relation: main_file
success: 1
file_date_updated: 2023-03-25T10:01:03Z
has_accepted_license: '1'
keyword:
- Teaching and learning of specific topics in university mathematics
- Transition to
- across and from university mathematics
- Student Teachers
- Geometry
- Congruence
- Double Discontinuity.
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://hal.univ-reims.fr/INDRUM2022/
oa: '1'
place: Hannover
publication: Proceedings of the Fourth Conference of the International Network for
Didactic Research in University Mathematics (INDRUM 2022, 19-22 October 2022)
publication_status: published
publisher: University of Hannover and INDRUM.
quality_controlled: '1'
status: public
title: Student Teachers ’ Knowledge of Congruence before a University Course on Geometry
type: conference
user_id: '32202'
year: '2023'
...
---
_id: '35322'
author:
- first_name: Kai-Uwe
full_name: Bux, Kai-Uwe
last_name: Bux
- first_name: Joachim
full_name: Hilgert, Joachim
id: '220'
last_name: Hilgert
- first_name: Tobias
full_name: Weich, Tobias
id: '49178'
last_name: Weich
orcid: 0000-0002-9648-6919
citation:
ama: Bux K-U, Hilgert J, Weich T. Poisson transforms for trees of bounded degree.
Journal of Spectral Theory. 2022;12(2):659-681. doi:10.4171/jst/414
apa: Bux, K.-U., Hilgert, J., & Weich, T. (2022). Poisson transforms for trees
of bounded degree. Journal of Spectral Theory, 12(2), 659–681. https://doi.org/10.4171/jst/414
bibtex: '@article{Bux_Hilgert_Weich_2022, title={Poisson transforms for trees of
bounded degree}, volume={12}, DOI={10.4171/jst/414},
number={2}, journal={Journal of Spectral Theory}, publisher={European Mathematical
Society - EMS - Publishing House GmbH}, author={Bux, Kai-Uwe and Hilgert, Joachim
and Weich, Tobias}, year={2022}, pages={659–681} }'
chicago: 'Bux, Kai-Uwe, Joachim Hilgert, and Tobias Weich. “Poisson Transforms for
Trees of Bounded Degree.” Journal of Spectral Theory 12, no. 2 (2022):
659–81. https://doi.org/10.4171/jst/414.'
ieee: 'K.-U. Bux, J. Hilgert, and T. Weich, “Poisson transforms for trees of bounded
degree,” Journal of Spectral Theory, vol. 12, no. 2, pp. 659–681, 2022,
doi: 10.4171/jst/414.'
mla: Bux, Kai-Uwe, et al. “Poisson Transforms for Trees of Bounded Degree.” Journal
of Spectral Theory, vol. 12, no. 2, European Mathematical Society - EMS -
Publishing House GmbH, 2022, pp. 659–81, doi:10.4171/jst/414.
short: K.-U. Bux, J. Hilgert, T. Weich, Journal of Spectral Theory 12 (2022) 659–681.
date_created: 2023-01-06T08:49:06Z
date_updated: 2024-02-19T06:28:12Z
department:
- _id: '10'
- _id: '623'
- _id: '548'
- _id: '91'
doi: 10.4171/jst/414
intvolume: ' 12'
issue: '2'
keyword:
- Geometry and Topology
- Mathematical Physics
- Statistical and Nonlinear Physics
language:
- iso: eng
page: 659-681
publication: Journal of Spectral Theory
publication_identifier:
issn:
- 1664-039X
publication_status: published
publisher: European Mathematical Society - EMS - Publishing House GmbH
status: public
title: Poisson transforms for trees of bounded degree
type: journal_article
user_id: '49063'
volume: 12
year: '2022'
...
---
_id: '34818'
article_number: '101687'
article_type: original
author:
- first_name: Maximilian
full_name: Hanusch, Maximilian
id: '30905'
last_name: Hanusch
citation:
ama: Hanusch M. Symmetries of analytic curves. Differential Geometry and its
Applications. 2021;74. doi:10.1016/j.difgeo.2020.101687
apa: Hanusch, M. (2021). Symmetries of analytic curves. Differential Geometry
and Its Applications, 74, Article 101687. https://doi.org/10.1016/j.difgeo.2020.101687
bibtex: '@article{Hanusch_2021, title={Symmetries of analytic curves}, volume={74},
DOI={10.1016/j.difgeo.2020.101687},
number={101687}, journal={Differential Geometry and its Applications}, publisher={Elsevier
BV}, author={Hanusch, Maximilian}, year={2021} }'
chicago: Hanusch, Maximilian. “Symmetries of Analytic Curves.” Differential Geometry
and Its Applications 74 (2021). https://doi.org/10.1016/j.difgeo.2020.101687.
ieee: 'M. Hanusch, “Symmetries of analytic curves,” Differential Geometry and
its Applications, vol. 74, Art. no. 101687, 2021, doi: 10.1016/j.difgeo.2020.101687.'
mla: Hanusch, Maximilian. “Symmetries of Analytic Curves.” Differential Geometry
and Its Applications, vol. 74, 101687, Elsevier BV, 2021, doi:10.1016/j.difgeo.2020.101687.
short: M. Hanusch, Differential Geometry and Its Applications 74 (2021).
date_created: 2022-12-22T09:20:30Z
date_updated: 2023-01-09T18:07:26Z
department:
- _id: '93'
doi: 10.1016/j.difgeo.2020.101687
extern: '1'
intvolume: ' 74'
keyword:
- Geometry and Topology
- Analysis
language:
- iso: eng
publication: Differential Geometry and its Applications
publication_identifier:
issn:
- 0926-2245
publication_status: published
publisher: Elsevier BV
status: public
title: Symmetries of analytic curves
type: journal_article
user_id: '30905'
volume: 74
year: '2021'
...
---
_id: '22274'
abstract:
- lang: eng
text: 'The use of high-strength steel and aluminium is rising due to the intensified
efforts being made in lightweight design, and self-piercing riveting is becoming
increasingly important. Conventional rivets for self-piercing riveting differ
in their geometry, the material used, the condition of the material and the coating.
To shorten the manufacturing process, the use of stainless steel with high strain
hardening as the rivet material represents a promising approach. This allows the
coating of the rivets to be omitted due to the corrosion resistance of the material
and, since the strength of the stainless steel is achieved by cold forming, heat
treatment is no longer required. In addition, it is possible to adjust the local
strength within the rivet. Because of that, the authors have elaborated a concept
for using high nitrogen steel 1.3815 as the rivet material. The present investigation
focusses on the joint strength in order to evaluate the capability of rivets in
high nitrogen steel by comparison to conventional rivets made of treatable steel.
Due to certain challenges in the forming process of the high nitrogen steel rivets,
deviations result from the targeted rivet geometry. Mainly these deviations cause
a lower joint strength with these rivets, which is, however, adequate. All in
all, the capability of the new rivet is proven by the results of this investigation. '
author:
- first_name: Benedikt
full_name: Uhe, Benedikt
id: '38131'
last_name: Uhe
- first_name: Clara-Maria
full_name: Kuball, Clara-Maria
last_name: Kuball
- first_name: Marion
full_name: Merklein, Marion
last_name: Merklein
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
citation:
ama: 'Uhe B, Kuball C-M, Merklein M, Meschut G. Strength of self-piercing riveted
Joints with conventional Rivets and Rivets made of High Nitrogen Steel. In: ;
2021. doi:10.25518/esaform21.1911'
apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2021). Strength
of self-piercing riveted Joints with conventional Rivets and Rivets made of High
Nitrogen Steel. 24th International Conference on Material Forming (ESAFORM),
Liège, Belgien. https://doi.org/10.25518/esaform21.1911
bibtex: '@inproceedings{Uhe_Kuball_Merklein_Meschut_2021, title={Strength of self-piercing
riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel},
DOI={10.25518/esaform21.1911},
author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut,
Gerson}, year={2021} }'
chicago: Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut.
“Strength of Self-Piercing Riveted Joints with Conventional Rivets and Rivets
Made of High Nitrogen Steel,” 2021. https://doi.org/10.25518/esaform21.1911.
ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Strength of self-piercing
riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel,”
presented at the 24th International Conference on Material Forming (ESAFORM),
Liège, Belgien, 2021, doi: 10.25518/esaform21.1911.'
mla: Uhe, Benedikt, et al. Strength of Self-Piercing Riveted Joints with Conventional
Rivets and Rivets Made of High Nitrogen Steel. 2021, doi:10.25518/esaform21.1911.
short: 'B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, in: 2021.'
conference:
end_date: 2021-04-16
location: Liège, Belgien
name: 24th International Conference on Material Forming (ESAFORM)
start_date: 2021-04-14
date_created: 2021-05-31T10:17:37Z
date_updated: 2026-02-27T10:25:13Z
department:
- _id: '157'
doi: 10.25518/esaform21.1911
keyword:
- Self-piercing Riveting
- Joining Technology
- Rivet Geometry
- Rivet Material
- High Nitrogen Steel
- Joint Strength
language:
- iso: eng
quality_controlled: '1'
status: public
title: Strength of self-piercing riveted Joints with conventional Rivets and Rivets
made of High Nitrogen Steel
type: conference
user_id: '53912'
year: '2021'
...
---
_id: '29545'
author:
- first_name: Frédéric
full_name: Jean, Frédéric
last_name: Jean
- first_name: Sofya
full_name: Maslovskaya, Sofya
id: '87909'
last_name: Maslovskaya
- first_name: Igor
full_name: Zelenko, Igor
last_name: Zelenko
citation:
ama: Jean F, Maslovskaya S, Zelenko I. On Weyl’s type theorems and genericity of
projective rigidity in sub-Riemannian geometry. Geometriae Dedicata. 2020;213(1):295-314.
doi:10.1007/s10711-020-00581-z
apa: Jean, F., Maslovskaya, S., & Zelenko, I. (2020). On Weyl’s type theorems
and genericity of projective rigidity in sub-Riemannian geometry. Geometriae
Dedicata, 213(1), 295–314. https://doi.org/10.1007/s10711-020-00581-z
bibtex: '@article{Jean_Maslovskaya_Zelenko_2020, title={On Weyl’s type theorems
and genericity of projective rigidity in sub-Riemannian geometry}, volume={213},
DOI={10.1007/s10711-020-00581-z},
number={1}, journal={Geometriae Dedicata}, publisher={Springer Science and Business
Media LLC}, author={Jean, Frédéric and Maslovskaya, Sofya and Zelenko, Igor},
year={2020}, pages={295–314} }'
chicago: 'Jean, Frédéric, Sofya Maslovskaya, and Igor Zelenko. “On Weyl’s Type Theorems
and Genericity of Projective Rigidity in Sub-Riemannian Geometry.” Geometriae
Dedicata 213, no. 1 (2020): 295–314. https://doi.org/10.1007/s10711-020-00581-z.'
ieee: 'F. Jean, S. Maslovskaya, and I. Zelenko, “On Weyl’s type theorems and genericity
of projective rigidity in sub-Riemannian geometry,” Geometriae Dedicata,
vol. 213, no. 1, pp. 295–314, 2020, doi: 10.1007/s10711-020-00581-z.'
mla: Jean, Frédéric, et al. “On Weyl’s Type Theorems and Genericity of Projective
Rigidity in Sub-Riemannian Geometry.” Geometriae Dedicata, vol. 213, no.
1, Springer Science and Business Media LLC, 2020, pp. 295–314, doi:10.1007/s10711-020-00581-z.
short: F. Jean, S. Maslovskaya, I. Zelenko, Geometriae Dedicata 213 (2020) 295–314.
date_created: 2022-01-26T13:19:18Z
date_updated: 2022-01-26T13:19:39Z
department:
- _id: '636'
doi: 10.1007/s10711-020-00581-z
intvolume: ' 213'
issue: '1'
keyword:
- Geometry and Topology
language:
- iso: eng
page: 295-314
publication: Geometriae Dedicata
publication_identifier:
issn:
- 0046-5755
- 1572-9168
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: On Weyl’s type theorems and genericity of projective rigidity in sub-Riemannian
geometry
type: journal_article
user_id: '87909'
volume: 213
year: '2020'
...
---
_id: '19973'
abstract:
- lang: eng
text: As a result of lightweight design, increased use is being made of high-strength
steel and aluminium in car bodies. Self-piercing riveting is an established technique
for joining these materials. The dissimilar properties of the two materials have
led to a number of different rivet geometries in the past. Each rivet geometry
fulfils the requirements of the materials within a limited range. In the present
investigation, an improved rivet geometry is developed, which permits the reliable
joining of two material combinations that could only be joined by two different
rivet geometries up until now. Material combination 1 consists of high-strength
steel on both sides, while material combination 2 comprises aluminium on the punch
side and high-strength steel on the die side. The material flow and the stress
and strain conditions prevailing during the joining process are analysed by means
of numerical simulation. The rivet geometry is then improved step-by-step on the
basis of this analysis. Finally, the improved rivet geometry is manufactured and
the findings of the investigation are verified in experimental joining tests.
article_type: original
author:
- first_name: Benedikt
full_name: Uhe, Benedikt
id: '38131'
last_name: Uhe
- first_name: Clara-Maria
full_name: Kuball, Clara-Maria
last_name: Kuball
- first_name: Marion
full_name: Merklein, Marion
last_name: Merklein
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
citation:
ama: Uhe B, Kuball C-M, Merklein M, Meschut G. Improvement of a rivet geometry for
the self-piercing riveting of high-strength steel and multi-material joints. Production
Engineering. 2020;14:417-423. doi:10.1007/s11740-020-00973-w
apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2020). Improvement
of a rivet geometry for the self-piercing riveting of high-strength steel and
multi-material joints. Production Engineering, 14, 417–423. https://doi.org/10.1007/s11740-020-00973-w
bibtex: '@article{Uhe_Kuball_Merklein_Meschut_2020, title={Improvement of a rivet
geometry for the self-piercing riveting of high-strength steel and multi-material
joints}, volume={14}, DOI={10.1007/s11740-020-00973-w},
journal={Production Engineering}, author={Uhe, Benedikt and Kuball, Clara-Maria
and Merklein, Marion and Meschut, Gerson}, year={2020}, pages={417–423} }'
chicago: 'Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut.
“Improvement of a Rivet Geometry for the Self-Piercing Riveting of High-Strength
Steel and Multi-Material Joints.” Production Engineering 14 (2020): 417–23.
https://doi.org/10.1007/s11740-020-00973-w.'
ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Improvement of a rivet
geometry for the self-piercing riveting of high-strength steel and multi-material
joints,” Production Engineering, vol. 14, pp. 417–423, 2020, doi: 10.1007/s11740-020-00973-w.'
mla: Uhe, Benedikt, et al. “Improvement of a Rivet Geometry for the Self-Piercing
Riveting of High-Strength Steel and Multi-Material Joints.” Production Engineering,
vol. 14, 2020, pp. 417–23, doi:10.1007/s11740-020-00973-w.
short: B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, Production Engineering 14
(2020) 417–423.
date_created: 2020-10-12T08:14:13Z
date_updated: 2026-02-27T10:41:55Z
department:
- _id: '157'
doi: 10.1007/s11740-020-00973-w
intvolume: ' 14'
keyword:
- Self-piercing riveting
- Joining technology
- Rivet geometry
- Multi-material design
- High-strength steel
- Aluminium
language:
- iso: eng
page: 417-423
publication: Production Engineering
publication_status: published
quality_controlled: '1'
status: public
title: Improvement of a rivet geometry for the self-piercing riveting of high-strength
steel and multi-material joints
type: journal_article
user_id: '53912'
volume: 14
year: '2020'
...
---
_id: '8162'
abstract:
- lang: eng
text: 'The constraint satisfaction problems k-SAT and Quantum k-SAT (k-QSAT) are
canonical NP-complete and QMA_1-complete problems (for k >= 3), respectively,
where QMA_1 is a quantum generalization of NP with one-sided error. Whereas k-SAT
has been well-studied for special tractable cases, as well as from a parameterized
complexity perspective, much less is known in similar settings for k-QSAT. Here,
we study the open problem of computing satisfying assignments to k-QSAT instances
which have a "matching" or "dimer covering"; this is an NP problem whose decision
variant is trivial, but whose search complexity remains open. Our results fall
into three directions, all of which relate to the "matching" setting: (1) We give
a polynomial-time classical algorithm for k-QSAT when all qubits occur in at most
two clauses. (2) We give a parameterized algorithm for k-QSAT instances from a
certain non-trivial class, which allows us to obtain exponential speedups over
brute force methods in some cases by reducing the problem to solving for a single
root of a single univariate polynomial. (3) We conduct a structural graph theoretic
study of 3-QSAT interaction graphs which have a "matching". We remark that the
results of (2), in particular, introduce a number of new tools to the study of
Quantum SAT, including graph theoretic concepts such as transfer filtrations and
blow-ups from algebraic geometry; we hope these prove useful elsewhere.'
author:
- first_name: Marco
full_name: Aldi, Marco
last_name: Aldi
- first_name: Niel
full_name: de Beaudrap, Niel
last_name: de Beaudrap
- first_name: Sevag
full_name: Gharibian, Sevag
id: '71541'
last_name: Gharibian
orcid: 0000-0002-9992-3379
- first_name: Seyran
full_name: Saeedi, Seyran
last_name: Saeedi
citation:
ama: 'Aldi M, de Beaudrap N, Gharibian S, Saeedi S. On Efficiently Solvable Cases
of Quantum k-SAT. In: Potapov I, Spirakis P, Worrell J, eds. 43rd International
Symposium on Mathematical Foundations of Computer Science (MFCS 2018). Vol
117. Leibniz International Proceedings in Informatics (LIPIcs). Schloss Dagstuhl
- Leibniz-Zentrum fuer Informatik; 2018:38:1-38:16. doi:10.4230/LIPIcs.MFCS.2018.38'
apa: Aldi, M., de Beaudrap, N., Gharibian, S., & Saeedi, S. (2018). On Efficiently
Solvable Cases of Quantum k-SAT. In I. Potapov, P. Spirakis, & J. Worrell
(Eds.), 43rd International Symposium on Mathematical Foundations of Computer
Science (MFCS 2018) (Vol. 117, p. 38:1-38:16). Schloss Dagstuhl - Leibniz-Zentrum
fuer Informatik. https://doi.org/10.4230/LIPIcs.MFCS.2018.38
bibtex: '@inproceedings{Aldi_de Beaudrap_Gharibian_Saeedi_2018, place={Dagstuhl,
Germany}, series={Leibniz International Proceedings in Informatics (LIPIcs)},
title={On Efficiently Solvable Cases of Quantum k-SAT}, volume={117}, DOI={10.4230/LIPIcs.MFCS.2018.38},
booktitle={43rd International Symposium on Mathematical Foundations of Computer
Science (MFCS 2018)}, publisher={Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik},
author={Aldi, Marco and de Beaudrap, Niel and Gharibian, Sevag and Saeedi, Seyran},
editor={Potapov, Igor and Spirakis, Paul and Worrell, James}, year={2018}, pages={38:1-38:16},
collection={Leibniz International Proceedings in Informatics (LIPIcs)} }'
chicago: 'Aldi, Marco, Niel de Beaudrap, Sevag Gharibian, and Seyran Saeedi. “On
Efficiently Solvable Cases of Quantum K-SAT.” In 43rd International Symposium
on Mathematical Foundations of Computer Science (MFCS 2018), edited by Igor
Potapov, Paul Spirakis, and James Worrell, 117:38:1-38:16. Leibniz International
Proceedings in Informatics (LIPIcs). Dagstuhl, Germany: Schloss Dagstuhl - Leibniz-Zentrum
fuer Informatik, 2018. https://doi.org/10.4230/LIPIcs.MFCS.2018.38.'
ieee: 'M. Aldi, N. de Beaudrap, S. Gharibian, and S. Saeedi, “On Efficiently Solvable
Cases of Quantum k-SAT,” in 43rd International Symposium on Mathematical Foundations
of Computer Science (MFCS 2018), Liverpool, UK, 2018, vol. 117, p. 38:1-38:16,
doi: 10.4230/LIPIcs.MFCS.2018.38.'
mla: Aldi, Marco, et al. “On Efficiently Solvable Cases of Quantum K-SAT.” 43rd
International Symposium on Mathematical Foundations of Computer Science (MFCS
2018), edited by Igor Potapov et al., vol. 117, Schloss Dagstuhl - Leibniz-Zentrum
fuer Informatik, 2018, p. 38:1-38:16, doi:10.4230/LIPIcs.MFCS.2018.38.
short: 'M. Aldi, N. de Beaudrap, S. Gharibian, S. Saeedi, in: I. Potapov, P. Spirakis,
J. Worrell (Eds.), 43rd International Symposium on Mathematical Foundations of
Computer Science (MFCS 2018), Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik,
Dagstuhl, Germany, 2018, p. 38:1-38:16.'
conference:
location: Liverpool, UK
name: 43rd International Symposium on Mathematical Foundations of Computer Science
(MFCS 2018)
date_created: 2019-03-01T11:34:41Z
date_updated: 2023-02-28T11:01:16Z
department:
- _id: '623'
- _id: '7'
doi: 10.4230/LIPIcs.MFCS.2018.38
editor:
- first_name: Igor
full_name: Potapov, Igor
last_name: Potapov
- first_name: Paul
full_name: Spirakis, Paul
last_name: Spirakis
- first_name: James
full_name: Worrell, James
last_name: Worrell
external_id:
arxiv:
- '1712.09617'
intvolume: ' 117'
keyword:
- search complexity
- local Hamiltonian
- Quantum SAT
- algebraic geometry
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://drops.dagstuhl.de/opus/volltexte/2018/9620/
oa: '1'
page: 38:1-38:16
place: Dagstuhl, Germany
publication: 43rd International Symposium on Mathematical Foundations of Computer
Science (MFCS 2018)
publication_identifier:
unknown:
- 978-3-95977-086-6
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik
series_title: Leibniz International Proceedings in Informatics (LIPIcs)
status: public
title: On Efficiently Solvable Cases of Quantum k-SAT
type: conference
user_id: '71541'
volume: 117
year: '2018'
...
---
_id: '19943'
abstract:
- lang: eng
text: 'In this paper we continue our study of bifurcations of solutions of boundary-value
problems for symplectic maps arising as Hamiltonian diffeomorphisms. These have
been shown to be connected to catastrophe theory via generating functions and
ordinary and reversal phase space symmetries have been considered. Here we present
a convenient, coordinate free framework to analyse separated Lagrangian boundary
value problems which include classical Dirichlet, Neumann and Robin boundary value
problems. The framework is then used to prove the existence of obstructions arising
from conformal symplectic symmetries on the bifurcation behaviour of solutions
to Hamiltonian boundary value problems. Under non-degeneracy conditions, a group
action by conformal symplectic symmetries has the effect that the flow map cannot
degenerate in a direction which is tangential to the action. This imposes restrictions
on which singularities can occur in boundary value problems. Our results generalise
classical results about conjugate loci on Riemannian manifolds to a large class
of Hamiltonian boundary value problems with, for example, scaling symmetries. '
article_type: original
author:
- first_name: Robert I
full_name: McLachlan, Robert I
last_name: McLachlan
- first_name: Christian
full_name: Offen, Christian
id: '85279'
last_name: Offen
orcid: https://orcid.org/0000-0002-5940-8057
citation:
ama: McLachlan RI, Offen C. Hamiltonian boundary value problems, conformal symplectic
symmetries, and conjugate loci. New Zealand Journal of Mathematics. 2018;48:83-99.
doi:10.53733/34
apa: McLachlan, R. I., & Offen, C. (2018). Hamiltonian boundary value problems,
conformal symplectic symmetries, and conjugate loci. New Zealand Journal of
Mathematics, 48, 83–99. https://doi.org/10.53733/34
bibtex: '@article{McLachlan_Offen_2018, title={Hamiltonian boundary value problems,
conformal symplectic symmetries, and conjugate loci}, volume={48}, DOI={10.53733/34 }, journal={New Zealand Journal of Mathematics}, author={McLachlan,
Robert I and Offen, Christian}, year={2018}, pages={83–99} }'
chicago: 'McLachlan, Robert I, and Christian Offen. “Hamiltonian Boundary Value
Problems, Conformal Symplectic Symmetries, and Conjugate Loci.” New Zealand
Journal of Mathematics 48 (2018): 83–99. https://doi.org/10.53733/34 .'
ieee: 'R. I. McLachlan and C. Offen, “Hamiltonian boundary value problems, conformal
symplectic symmetries, and conjugate loci,” New Zealand Journal of Mathematics,
vol. 48, pp. 83–99, 2018, doi: 10.53733/34
.'
mla: McLachlan, Robert I., and Christian Offen. “Hamiltonian Boundary Value Problems,
Conformal Symplectic Symmetries, and Conjugate Loci.” New Zealand Journal of
Mathematics, vol. 48, 2018, pp. 83–99, doi:10.53733/34 .
short: R.I. McLachlan, C. Offen, New Zealand Journal of Mathematics 48 (2018) 83–99.
date_created: 2020-10-06T16:39:08Z
date_updated: 2023-09-21T07:29:24Z
ddc:
- '510'
department:
- _id: '636'
doi: '10.53733/34 '
extern: '1'
external_id:
arxiv:
- '1804.07479'
file:
- access_level: open_access
content_type: application/pdf
creator: coffen
date_created: 2020-10-06T16:49:29Z
date_updated: 2020-10-07T14:04:01Z
file_id: '19946'
file_name: Hamiltonian_Boundary_Value_Problems,_Conformal_Symplectic_Symmetries,_and_Conjugate_Loci.pdf
file_size: 3126111
relation: main_file
title: Hamiltonian Boundary Value Problems, Conformal Symplectic Symmetries, and
Conjugate Loci
file_date_updated: 2020-10-07T14:04:01Z
has_accepted_license: '1'
intvolume: ' 48'
keyword:
- Hamiltonian boundary value problems
- singularities
- conformal symplectic geometry
- catastrophe theory
- conjugate loci
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://nzjmath.org/index.php/NZJMATH/article/view/34
oa: '1'
page: 83-99
publication: New Zealand Journal of Mathematics
publication_status: published
quality_controlled: '1'
status: public
title: Hamiltonian boundary value problems, conformal symplectic symmetries, and conjugate
loci
type: journal_article
user_id: '85279'
volume: 48
year: '2018'
...
---
_id: '32020'
author:
- first_name: Benjamin
full_name: Küster, Benjamin
last_name: Küster
citation:
ama: Küster B. On the semiclassical functional calculus for h-dependent functions.
Annals of Global Analysis and Geometry. 2017;52(1):57-97. doi:10.1007/s10455-017-9549-1
apa: Küster, B. (2017). On the semiclassical functional calculus for h-dependent
functions. Annals of Global Analysis and Geometry, 52(1), 57–97.
https://doi.org/10.1007/s10455-017-9549-1
bibtex: '@article{Küster_2017, title={On the semiclassical functional calculus for
h-dependent functions}, volume={52}, DOI={10.1007/s10455-017-9549-1},
number={1}, journal={Annals of Global Analysis and Geometry}, publisher={Springer
Science and Business Media LLC}, author={Küster, Benjamin}, year={2017}, pages={57–97}
}'
chicago: 'Küster, Benjamin. “On the Semiclassical Functional Calculus for H-Dependent
Functions.” Annals of Global Analysis and Geometry 52, no. 1 (2017): 57–97.
https://doi.org/10.1007/s10455-017-9549-1.'
ieee: 'B. Küster, “On the semiclassical functional calculus for h-dependent functions,”
Annals of Global Analysis and Geometry, vol. 52, no. 1, pp. 57–97, 2017,
doi: 10.1007/s10455-017-9549-1.'
mla: Küster, Benjamin. “On the Semiclassical Functional Calculus for H-Dependent
Functions.” Annals of Global Analysis and Geometry, vol. 52, no. 1, Springer
Science and Business Media LLC, 2017, pp. 57–97, doi:10.1007/s10455-017-9549-1.
short: B. Küster, Annals of Global Analysis and Geometry 52 (2017) 57–97.
date_created: 2022-06-20T08:47:57Z
date_updated: 2024-04-11T12:26:30Z
department:
- _id: '548'
doi: 10.1007/s10455-017-9549-1
extern: '1'
intvolume: ' 52'
issue: '1'
keyword:
- Geometry and Topology
- Analysis
language:
- iso: eng
page: 57-97
publication: Annals of Global Analysis and Geometry
publication_identifier:
issn:
- 0232-704X
- 1572-9060
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: On the semiclassical functional calculus for h-dependent functions
type: journal_article
user_id: '70575'
volume: 52
year: '2017'
...
---
_id: '9955'
abstract:
- lang: eng
text: Wire bonding has been an established packaging technology for decades. When
introducing copper as wire material for high power applications, adaptations to
the bonding process and to machines became necessary. Here, challenges occur due
to the stiffer wire material and changing oxide layers on the contact partners.
To achieve sufficient process stability, a clean bond area is required, which
can only be achieved with high shear stresses in the contact partners surfaces.
These necessitate high normal forces to plastically deform the wire and substrate.
To achieve such high stresses in the contact area, the bonding tool needs to be
able to transmit the needed tangential forces to the top side of the wire. The
wire itself performs a shear movement and transmits the force into the contact
area to clean the contaminant and oxide layers and to level the desired bond surfaces.
The main function of the tool is to transmit these forces. If the bond tool can
only transmit low forces in the direction of excitation, the parameter space for
a stable bond process is severely restricted. Here, a modeling approach to estimate
how well different tool shapes meet the demand of transmitting high tangential
forces is presented. The model depends on wire deformation and thus on the ultrasonic
softening effect.
author:
- first_name: Simon
full_name: Althoff, Simon
last_name: Althoff
- first_name: Tobias
full_name: Meyer, Tobias
last_name: Meyer
- first_name: Andreas
full_name: Unger, Andreas
last_name: Unger
- first_name: Walter
full_name: Sextro, Walter
id: '21220'
last_name: Sextro
- first_name: Florian
full_name: Eacock, Florian
last_name: Eacock
citation:
ama: 'Althoff S, Meyer T, Unger A, Sextro W, Eacock F. Shape-Dependent Transmittable
Tangential Force of Wire Bond Tools. In: IEEE 66th Electronic Components and
Technology Conference. ; 2016:2103-2110. doi:10.1109/ECTC.2016.234'
apa: Althoff, S., Meyer, T., Unger, A., Sextro, W., & Eacock, F. (2016). Shape-Dependent
Transmittable Tangential Force of Wire Bond Tools. In IEEE 66th Electronic
Components and Technology Conference (pp. 2103–2110). https://doi.org/10.1109/ECTC.2016.234
bibtex: '@inproceedings{Althoff_Meyer_Unger_Sextro_Eacock_2016, title={Shape-Dependent
Transmittable Tangential Force of Wire Bond Tools}, DOI={10.1109/ECTC.2016.234},
booktitle={IEEE 66th Electronic Components and Technology Conference}, author={Althoff,
Simon and Meyer, Tobias and Unger, Andreas and Sextro, Walter and Eacock, Florian},
year={2016}, pages={2103–2110} }'
chicago: Althoff, Simon, Tobias Meyer, Andreas Unger, Walter Sextro, and Florian
Eacock. “Shape-Dependent Transmittable Tangential Force of Wire Bond Tools.” In
IEEE 66th Electronic Components and Technology Conference, 2103–10, 2016.
https://doi.org/10.1109/ECTC.2016.234.
ieee: S. Althoff, T. Meyer, A. Unger, W. Sextro, and F. Eacock, “Shape-Dependent
Transmittable Tangential Force of Wire Bond Tools,” in IEEE 66th Electronic
Components and Technology Conference, 2016, pp. 2103–2110.
mla: Althoff, Simon, et al. “Shape-Dependent Transmittable Tangential Force of Wire
Bond Tools.” IEEE 66th Electronic Components and Technology Conference,
2016, pp. 2103–10, doi:10.1109/ECTC.2016.234.
short: 'S. Althoff, T. Meyer, A. Unger, W. Sextro, F. Eacock, in: IEEE 66th Electronic
Components and Technology Conference, 2016, pp. 2103–2110.'
date_created: 2019-05-27T08:47:52Z
date_updated: 2020-05-07T05:33:52Z
department:
- _id: '151'
doi: 10.1109/ECTC.2016.234
keyword:
- finite element simulation
- wire bonding
- tool geometry
language:
- iso: eng
page: 2103-2110
project:
- _id: '92'
grant_number: 02 PQ2210
name: Intelligente Herstellung zuverlässiger Kupferbondverbindungen
publication: IEEE 66th Electronic Components and Technology Conference
quality_controlled: '1'
status: public
title: Shape-Dependent Transmittable Tangential Force of Wire Bond Tools
type: conference
user_id: '210'
year: '2016'
...
---
_id: '31274'
author:
- first_name: David
full_name: Borthwick, David
last_name: Borthwick
- first_name: Tobias
full_name: Weich, Tobias
id: '49178'
last_name: Weich
orcid: 0000-0002-9648-6919
citation:
ama: Borthwick D, Weich T. Symmetry reduction of holomorphic iterated function schemes
and factorization of Selberg zeta functions. Journal of Spectral Theory.
2016;6(2):267-329. doi:10.4171/jst/125
apa: Borthwick, D., & Weich, T. (2016). Symmetry reduction of holomorphic iterated
function schemes and factorization of Selberg zeta functions. Journal of Spectral
Theory, 6(2), 267–329. https://doi.org/10.4171/jst/125
bibtex: '@article{Borthwick_Weich_2016, title={Symmetry reduction of holomorphic
iterated function schemes and factorization of Selberg zeta functions}, volume={6},
DOI={10.4171/jst/125}, number={2},
journal={Journal of Spectral Theory}, publisher={European Mathematical Society
- EMS - Publishing House GmbH}, author={Borthwick, David and Weich, Tobias}, year={2016},
pages={267–329} }'
chicago: 'Borthwick, David, and Tobias Weich. “Symmetry Reduction of Holomorphic
Iterated Function Schemes and Factorization of Selberg Zeta Functions.” Journal
of Spectral Theory 6, no. 2 (2016): 267–329. https://doi.org/10.4171/jst/125.'
ieee: 'D. Borthwick and T. Weich, “Symmetry reduction of holomorphic iterated function
schemes and factorization of Selberg zeta functions,” Journal of Spectral Theory,
vol. 6, no. 2, pp. 267–329, 2016, doi: 10.4171/jst/125.'
mla: Borthwick, David, and Tobias Weich. “Symmetry Reduction of Holomorphic Iterated
Function Schemes and Factorization of Selberg Zeta Functions.” Journal of Spectral
Theory, vol. 6, no. 2, European Mathematical Society - EMS - Publishing House
GmbH, 2016, pp. 267–329, doi:10.4171/jst/125.
short: D. Borthwick, T. Weich, Journal of Spectral Theory 6 (2016) 267–329.
date_created: 2022-05-17T12:18:22Z
date_updated: 2022-05-19T10:15:17Z
department:
- _id: '10'
- _id: '623'
- _id: '548'
doi: 10.4171/jst/125
external_id:
arxiv:
- '1407.6134 '
intvolume: ' 6'
issue: '2'
keyword:
- Geometry and Topology
- Mathematical Physics
- Statistical and Nonlinear Physics
language:
- iso: eng
page: 267-329
publication: Journal of Spectral Theory
publication_identifier:
issn:
- 1664-039X
publication_status: published
publisher: European Mathematical Society - EMS - Publishing House GmbH
status: public
title: Symmetry reduction of holomorphic iterated function schemes and factorization
of Selberg zeta functions
type: journal_article
user_id: '49178'
volume: 6
year: '2016'
...
---
_id: '38037'
author:
- first_name: Margit
full_name: Rösler, Margit
id: '37390'
last_name: Rösler
- first_name: Michael
full_name: Voit, Michael
last_name: Voit
citation:
ama: 'Rösler M, Voit M. A Central Limit Theorem for Random Walks on the Dual of
a Compact Grassmannian. Symmetry, Integrability and Geometry: Methods and Applications.
2015;11(013):18pp. doi:10.3842/sigma.2015.013'
apa: 'Rösler, M., & Voit, M. (2015). A Central Limit Theorem for Random Walks
on the Dual of a Compact Grassmannian. Symmetry, Integrability and Geometry:
Methods and Applications, 11(013), 18pp. https://doi.org/10.3842/sigma.2015.013'
bibtex: '@article{Rösler_Voit_2015, title={A Central Limit Theorem for Random Walks
on the Dual of a Compact Grassmannian}, volume={11}, DOI={10.3842/sigma.2015.013},
number={013}, journal={Symmetry, Integrability and Geometry: Methods and Applications},
publisher={SIGMA (Symmetry, Integrability and Geometry: Methods and Application)},
author={Rösler, Margit and Voit, Michael}, year={2015}, pages={18pp} }'
chicago: 'Rösler, Margit, and Michael Voit. “A Central Limit Theorem for Random
Walks on the Dual of a Compact Grassmannian.” Symmetry, Integrability and Geometry:
Methods and Applications 11, no. 013 (2015): 18pp. https://doi.org/10.3842/sigma.2015.013.'
ieee: 'M. Rösler and M. Voit, “A Central Limit Theorem for Random Walks on the Dual
of a Compact Grassmannian,” Symmetry, Integrability and Geometry: Methods and
Applications, vol. 11, no. 013, p. 18pp, 2015, doi: 10.3842/sigma.2015.013.'
mla: 'Rösler, Margit, and Michael Voit. “A Central Limit Theorem for Random Walks
on the Dual of a Compact Grassmannian.” Symmetry, Integrability and Geometry:
Methods and Applications, vol. 11, no. 013, SIGMA (Symmetry, Integrability
and Geometry: Methods and Application), 2015, p. 18pp, doi:10.3842/sigma.2015.013.'
short: 'M. Rösler, M. Voit, Symmetry, Integrability and Geometry: Methods and Applications
11 (2015) 18pp.'
date_created: 2023-01-23T08:18:48Z
date_updated: 2023-01-24T22:15:37Z
department:
- _id: '555'
doi: 10.3842/sigma.2015.013
intvolume: ' 11'
issue: '013'
keyword:
- Geometry and Topology
- Mathematical Physics
- Analysis
language:
- iso: eng
page: 18pp
publication: 'Symmetry, Integrability and Geometry: Methods and Applications'
publication_identifier:
issn:
- 1815-0659
publication_status: published
publisher: 'SIGMA (Symmetry, Integrability and Geometry: Methods and Application)'
status: public
title: A Central Limit Theorem for Random Walks on the Dual of a Compact Grassmannian
type: journal_article
user_id: '93826'
volume: 11
year: '2015'
...
---
_id: '11832'
abstract:
- lang: eng
text: In this paper we propose an approach to retrieve the absolute geometry of
an acoustic sensor network, consisting of spatially distributed microphone arrays,
from reverberant speech input. The calibration relies on direction of arrival
measurements of the individual arrays. The proposed calibration algorithm is derived
from a maximum-likelihood approach employing circular statistics. Since a sensor
node consists of a microphone array with known intra-array geometry, we are able
to obtain an absolute geometry estimate, including angles and distances. Simulation
results demonstrate the effectiveness of the approach.
author:
- first_name: Florian
full_name: Jacob, Florian
last_name: Jacob
- first_name: Joerg
full_name: Schmalenstroeer, Joerg
id: '460'
last_name: Schmalenstroeer
- first_name: Reinhold
full_name: Haeb-Umbach, Reinhold
id: '242'
last_name: Haeb-Umbach
citation:
ama: 'Jacob F, Schmalenstroeer J, Haeb-Umbach R. DoA-Based Microphone Array Position
Self-Calibration Using Circular Statistic. In: 38th International Conference
on Acoustics, Speech, and Signal Processing (ICASSP 2013). ; 2013:116-120.
doi:10.1109/ICASSP.2013.6637620'
apa: Jacob, F., Schmalenstroeer, J., & Haeb-Umbach, R. (2013). DoA-Based Microphone
Array Position Self-Calibration Using Circular Statistic. 38th International
Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013), 116–120.
https://doi.org/10.1109/ICASSP.2013.6637620
bibtex: '@inproceedings{Jacob_Schmalenstroeer_Haeb-Umbach_2013, title={DoA-Based
Microphone Array Position Self-Calibration Using Circular Statistic}, DOI={10.1109/ICASSP.2013.6637620},
booktitle={38th International Conference on Acoustics, Speech, and Signal Processing
(ICASSP 2013)}, author={Jacob, Florian and Schmalenstroeer, Joerg and Haeb-Umbach,
Reinhold}, year={2013}, pages={116–120} }'
chicago: Jacob, Florian, Joerg Schmalenstroeer, and Reinhold Haeb-Umbach. “DoA-Based
Microphone Array Position Self-Calibration Using Circular Statistic.” In 38th
International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013),
116–20, 2013. https://doi.org/10.1109/ICASSP.2013.6637620.
ieee: 'F. Jacob, J. Schmalenstroeer, and R. Haeb-Umbach, “DoA-Based Microphone Array
Position Self-Calibration Using Circular Statistic,” in 38th International
Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013), 2013,
pp. 116–120, doi: 10.1109/ICASSP.2013.6637620.'
mla: Jacob, Florian, et al. “DoA-Based Microphone Array Position Self-Calibration
Using Circular Statistic.” 38th International Conference on Acoustics, Speech,
and Signal Processing (ICASSP 2013), 2013, pp. 116–20, doi:10.1109/ICASSP.2013.6637620.
short: 'F. Jacob, J. Schmalenstroeer, R. Haeb-Umbach, in: 38th International Conference
on Acoustics, Speech, and Signal Processing (ICASSP 2013), 2013, pp. 116–120.'
date_created: 2019-07-12T05:29:07Z
date_updated: 2023-10-26T08:11:12Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2013.6637620
keyword:
- Geometry calibration
- microphone arrays
- position self-calibration
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://groups.uni-paderborn.de/nt/pubs/2013/JacSchHae_ICASSP2013_Rev2.pdf
oa: '1'
page: 116-120
publication: 38th International Conference on Acoustics, Speech, and Signal Processing
(ICASSP 2013)
publication_identifier:
issn:
- 1520-6149
quality_controlled: '1'
related_material:
link:
- description: Presentation
relation: supplementary_material
url: https://groups.uni-paderborn.de/nt/pubs/2013/JaScHa13_Presentation.pdf
status: public
title: DoA-Based Microphone Array Position Self-Calibration Using Circular Statistic
type: conference
user_id: '460'
year: '2013'
...
---
_id: '11833'
abstract:
- lang: eng
text: In this paper we propose an approach to retrieve the geometry of an acoustic
sensor network consisting of spatially distributed microphone arrays from unconstrained
speech input. The calibration relies on Direction of Arrival (DoA) measurements
which do not require a clock synchronization among the sensor nodes. The calibration
problem is formulated as a cost function optimization task, which minimizes the
squared differences between measured and predicted observations and additionally
avoids the existence of minima that correspond to mirrored versions of the actual
sensor orientations. Further, outlier measurements caused by reverberation are
mitigated by a Random Sample Consensus (RANSAC) approach. The experimental results
show a mean positioning error of at most 25 cm even in highly reverberant environments.
author:
- first_name: Florian
full_name: Jacob, Florian
last_name: Jacob
- first_name: Joerg
full_name: Schmalenstroeer, Joerg
id: '460'
last_name: Schmalenstroeer
- first_name: Reinhold
full_name: Haeb-Umbach, Reinhold
id: '242'
last_name: Haeb-Umbach
citation:
ama: 'Jacob F, Schmalenstroeer J, Haeb-Umbach R. Microphone Array Position Self-Calibration
from Reverberant Speech Input. In: International Workshop on Acoustic Signal
Enhancement (IWAENC 2012). ; 2012.'
apa: Jacob, F., Schmalenstroeer, J., & Haeb-Umbach, R. (2012). Microphone Array
Position Self-Calibration from Reverberant Speech Input. International Workshop
on Acoustic Signal Enhancement (IWAENC 2012).
bibtex: '@inproceedings{Jacob_Schmalenstroeer_Haeb-Umbach_2012, title={Microphone
Array Position Self-Calibration from Reverberant Speech Input}, booktitle={International
Workshop on Acoustic Signal Enhancement (IWAENC 2012)}, author={Jacob, Florian
and Schmalenstroeer, Joerg and Haeb-Umbach, Reinhold}, year={2012} }'
chicago: Jacob, Florian, Joerg Schmalenstroeer, and Reinhold Haeb-Umbach. “Microphone
Array Position Self-Calibration from Reverberant Speech Input.” In International
Workshop on Acoustic Signal Enhancement (IWAENC 2012), 2012.
ieee: F. Jacob, J. Schmalenstroeer, and R. Haeb-Umbach, “Microphone Array Position
Self-Calibration from Reverberant Speech Input,” 2012.
mla: Jacob, Florian, et al. “Microphone Array Position Self-Calibration from Reverberant
Speech Input.” International Workshop on Acoustic Signal Enhancement (IWAENC
2012), 2012.
short: 'F. Jacob, J. Schmalenstroeer, R. Haeb-Umbach, in: International Workshop
on Acoustic Signal Enhancement (IWAENC 2012), 2012.'
date_created: 2019-07-12T05:29:08Z
date_updated: 2023-10-26T08:10:52Z
department:
- _id: '54'
keyword:
- Unsupervised
- geometry calibration
- microphone arrays
- position self-calibration
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://groups.uni-paderborn.de/nt/pubs/2012/JaScHa12.pdf
oa: '1'
publication: International Workshop on Acoustic Signal Enhancement (IWAENC 2012)
quality_controlled: '1'
related_material:
link:
- description: Video
relation: supplementary_material
url: https://groups.uni-paderborn.de/nt/pubs/2012/Microphine_Array_Position_Self-Calibration_from_Reverberant_Speech_Input.mp4
- description: Poster
relation: supplementary_material
url: https://groups.uni-paderborn.de/nt/pubs/2012/JaScHa12_Poster.pdf
- description: Demonstrator
relation: supplementary_material
url: https://groups.uni-paderborn.de/nt/pubs/2012/JaScHa12_Demonstrator.pdf
status: public
title: Microphone Array Position Self-Calibration from Reverberant Speech Input
type: conference
user_id: '460'
year: '2012'
...
---
_id: '11806'
abstract:
- lang: eng
text: Microphone arrays represent the basis for many challenging acoustic sensing
tasks. The accuracy of techniques like beamforming directly depends on a precise
knowledge of the relative positions of the sensors used. Unfortunately, for certain
use cases manually measuring the geometry of an array is not feasible due to practical
constraints. In this paper we present an approach to unsupervised shape calibration
of microphone array networks. We developed a hierarchical procedure that first
performs local shape calibration based on coherence analysis and then employs
SRP-PHAT in a network calibration method. Practical experiments demonstrate the
effectiveness of our approach especially for highly reverberant acoustic environments.
author:
- first_name: Marius
full_name: Hennecke, Marius
last_name: Hennecke
- first_name: Thomas
full_name: Ploetz, Thomas
last_name: Ploetz
- first_name: Gernot A.
full_name: Fink, Gernot A.
last_name: Fink
- first_name: Joerg
full_name: Schmalenstroeer, Joerg
id: '460'
last_name: Schmalenstroeer
- first_name: Reinhold
full_name: Haeb-Umbach, Reinhold
id: '242'
last_name: Haeb-Umbach
citation:
ama: 'Hennecke M, Ploetz T, Fink GA, Schmalenstroeer J, Haeb-Umbach R. A hierarchical
approach to unsupervised shape calibration of microphone array networks. In: IEEE/SP
15th Workshop on Statistical Signal Processing (SSP 2009). ; 2009:257-260.
doi:10.1109/SSP.2009.5278589'
apa: Hennecke, M., Ploetz, T., Fink, G. A., Schmalenstroeer, J., & Haeb-Umbach,
R. (2009). A hierarchical approach to unsupervised shape calibration of microphone
array networks. IEEE/SP 15th Workshop on Statistical Signal Processing (SSP
2009), 257–260. https://doi.org/10.1109/SSP.2009.5278589
bibtex: '@inproceedings{Hennecke_Ploetz_Fink_Schmalenstroeer_Haeb-Umbach_2009, title={A
hierarchical approach to unsupervised shape calibration of microphone array networks},
DOI={10.1109/SSP.2009.5278589},
booktitle={IEEE/SP 15th Workshop on Statistical Signal Processing (SSP 2009)},
author={Hennecke, Marius and Ploetz, Thomas and Fink, Gernot A. and Schmalenstroeer,
Joerg and Haeb-Umbach, Reinhold}, year={2009}, pages={257–260} }'
chicago: Hennecke, Marius, Thomas Ploetz, Gernot A. Fink, Joerg Schmalenstroeer,
and Reinhold Haeb-Umbach. “A Hierarchical Approach to Unsupervised Shape Calibration
of Microphone Array Networks.” In IEEE/SP 15th Workshop on Statistical Signal
Processing (SSP 2009), 257–60, 2009. https://doi.org/10.1109/SSP.2009.5278589.
ieee: 'M. Hennecke, T. Ploetz, G. A. Fink, J. Schmalenstroeer, and R. Haeb-Umbach,
“A hierarchical approach to unsupervised shape calibration of microphone array
networks,” in IEEE/SP 15th Workshop on Statistical Signal Processing (SSP 2009),
2009, pp. 257–260, doi: 10.1109/SSP.2009.5278589.'
mla: Hennecke, Marius, et al. “A Hierarchical Approach to Unsupervised Shape Calibration
of Microphone Array Networks.” IEEE/SP 15th Workshop on Statistical Signal
Processing (SSP 2009), 2009, pp. 257–60, doi:10.1109/SSP.2009.5278589.
short: 'M. Hennecke, T. Ploetz, G.A. Fink, J. Schmalenstroeer, R. Haeb-Umbach, in:
IEEE/SP 15th Workshop on Statistical Signal Processing (SSP 2009), 2009, pp. 257–260.'
date_created: 2019-07-12T05:28:37Z
date_updated: 2023-10-26T08:09:22Z
department:
- _id: '54'
doi: 10.1109/SSP.2009.5278589
keyword:
- acoustic sensing tasks
- array geometry
- calibration
- coherence analysis
- hierarchical procedure
- local shape calibration
- microphone array networks
- microphone arrays
- network calibration method
- sensor arrays
- SRP-PHAT
- unsupervised shape calibration
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://groups.uni-paderborn.de/nt/pubs/2009/HePlFiScHa09.pdf
oa: '1'
page: 257-260
publication: IEEE/SP 15th Workshop on Statistical Signal Processing (SSP 2009)
quality_controlled: '1'
status: public
title: A hierarchical approach to unsupervised shape calibration of microphone array
networks
type: conference
user_id: '460'
year: '2009'
...
---
_id: '2999'
author:
- first_name: Johannes
full_name: Blömer, Johannes
id: '23'
last_name: Blömer
- first_name: Stefanie
full_name: ' Naewe, Stefanie'
id: '1971'
last_name: ' Naewe'
citation:
ama: Blömer J, Naewe S. Sampling methods for shortest vectors, closest vectors
and successive minima. Theoretical Computer Science. 2009;410(18):1648-1665.
doi:10.1016/j.tcs.2008.12.045
apa: Blömer, J., & Naewe, S. (2009). Sampling methods for shortest vectors,
closest vectors and successive minima. Theoretical Computer Science, 410(18),
1648–1665. https://doi.org/10.1016/j.tcs.2008.12.045
bibtex: '@article{Blömer_ Naewe_2009, title={Sampling methods for shortest vectors,
closest vectors and successive minima}, volume={410}, DOI={10.1016/j.tcs.2008.12.045},
number={18}, journal={Theoretical Computer Science}, author={Blömer, Johannes
and Naewe, Stefanie}, year={2009}, pages={1648–1665} }'
chicago: 'Blömer, Johannes, and Stefanie Naewe. “Sampling Methods for Shortest
Vectors, Closest Vectors and Successive Minima.” Theoretical Computer Science
410, no. 18 (2009): 1648–65. https://doi.org/10.1016/j.tcs.2008.12.045.'
ieee: 'J. Blömer and S. Naewe, “Sampling methods for shortest vectors, closest
vectors and successive minima,” Theoretical Computer Science, vol. 410,
no. 18, pp. 1648–1665, 2009, doi: 10.1016/j.tcs.2008.12.045.'
mla: Blömer, Johannes, and Stefanie Naewe. “Sampling Methods for Shortest Vectors,
Closest Vectors and Successive Minima.” Theoretical Computer Science, vol.
410, no. 18, 2009, pp. 1648–65, doi:10.1016/j.tcs.2008.12.045.
short: J. Blömer, S. Naewe, Theoretical Computer Science 410 (2009) 1648–1665.
date_created: 2018-06-05T08:07:24Z
date_updated: 2024-08-08T12:18:04Z
department:
- _id: '64'
doi: 10.1016/j.tcs.2008.12.045
intvolume: ' 410'
issue: '18'
keyword:
- Geometry of numbers
- Lattices
- Shortest vectors
language:
- iso: eng
page: 1648 - 1665
publication: Theoretical Computer Science
publication_identifier:
issn:
- 0304-3975
publication_status: published
status: public
title: Sampling methods for shortest vectors, closest vectors and successive minima
type: journal_article
user_id: '49063'
volume: 410
year: '2009'
...
---
_id: '39941'
author:
- first_name: Margit
full_name: Rösler, Margit
id: '37390'
last_name: Rösler
- first_name: Michael
full_name: Voit, Michael
last_name: Voit
citation:
ama: 'Rösler M, Voit M. A Limit Relation for Dunkl-Bessel Functions of Type A and
B. Symmetry, Integrability and Geometry: Methods and Applications. 2008;4(083):9pp.
doi:10.3842/sigma.2008.083'
apa: 'Rösler, M., & Voit, M. (2008). A Limit Relation for Dunkl-Bessel Functions
of Type A and B. Symmetry, Integrability and Geometry: Methods and Applications,
4(083), 9pp. https://doi.org/10.3842/sigma.2008.083'
bibtex: '@article{Rösler_Voit_2008, title={A Limit Relation for Dunkl-Bessel Functions
of Type A and B}, volume={4}, DOI={10.3842/sigma.2008.083},
number={083}, journal={Symmetry, Integrability and Geometry: Methods and Applications},
publisher={SIGMA (Symmetry, Integrability and Geometry: Methods and Application)},
author={Rösler, Margit and Voit, Michael}, year={2008}, pages={9pp} }'
chicago: 'Rösler, Margit, and Michael Voit. “A Limit Relation for Dunkl-Bessel Functions
of Type A and B.” Symmetry, Integrability and Geometry: Methods and Applications
4, no. 083 (2008): 9pp. https://doi.org/10.3842/sigma.2008.083.'
ieee: 'M. Rösler and M. Voit, “A Limit Relation for Dunkl-Bessel Functions of Type
A and B,” Symmetry, Integrability and Geometry: Methods and Applications,
vol. 4, no. 083, p. 9pp, 2008, doi: 10.3842/sigma.2008.083.'
mla: 'Rösler, Margit, and Michael Voit. “A Limit Relation for Dunkl-Bessel Functions
of Type A and B.” Symmetry, Integrability and Geometry: Methods and Applications,
vol. 4, no. 083, SIGMA (Symmetry, Integrability and Geometry: Methods and Application),
2008, p. 9pp, doi:10.3842/sigma.2008.083.'
short: 'M. Rösler, M. Voit, Symmetry, Integrability and Geometry: Methods and Applications
4 (2008) 9pp.'
date_created: 2023-01-25T09:50:01Z
date_updated: 2023-01-26T17:47:57Z
department:
- _id: '555'
doi: 10.3842/sigma.2008.083
extern: '1'
intvolume: ' 4'
issue: '083'
keyword:
- Geometry and Topology
- Mathematical Physics
- Analysis
language:
- iso: eng
page: 9pp
publication: 'Symmetry, Integrability and Geometry: Methods and Applications'
publication_identifier:
issn:
- 1815-0659
publication_status: published
publisher: 'SIGMA (Symmetry, Integrability and Geometry: Methods and Application)'
status: public
title: A Limit Relation for Dunkl-Bessel Functions of Type A and B
type: journal_article
user_id: '93826'
volume: 4
year: '2008'
...