---
_id: '16296'
abstract:
- lang: eng
  text: "Multiobjective optimization plays an increasingly important role in modern\r\napplications,
    where several objectives are often of equal importance. The task\r\nin multiobjective
    optimization and multiobjective optimal control is therefore\r\nto compute the
    set of optimal compromises (the Pareto set) between the\r\nconflicting objectives.
    Since the Pareto set generally consists of an infinite\r\nnumber of solutions,
    the computational effort can quickly become challenging\r\nwhich is particularly
    problematic when the objectives are costly to evaluate as\r\nis the case for models
    governed by partial differential equations (PDEs). To\r\ndecrease the numerical
    effort to an affordable amount, surrogate models can be\r\nused to replace the
    expensive PDE evaluations. Existing multiobjective\r\noptimization methods using
    model reduction are limited either to low parameter\r\ndimensions or to few (ideally
    two) objectives. In this article, we present a\r\ncombination of the reduced basis
    model reduction method with a continuation\r\napproach using inexact gradients.
    The resulting approach can handle an\r\narbitrary number of objectives while yielding
    a significant reduction in\r\ncomputing time."
author:
- first_name: Stefan
  full_name: Banholzer, Stefan
  last_name: Banholzer
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: https://orcid.org/0000-0002-3389-793X
- first_name: Stefan
  full_name: Volkwein, Stefan
  last_name: Volkwein
citation:
  ama: 'Banholzer S, Gebken B, Dellnitz M, Peitz S, Volkwein S. ROM-Based Multiobjective
    Optimization of Elliptic PDEs via Numerical Continuation. In: Michael H, Roland
    H, Christian K, Michael U, Stefan U, eds. <i>Non-Smooth and Complementarity-Based
    Distributed Parameter Systems</i>. Springer; 2022:43-76. doi:<a href="https://doi.org/10.1007/978-3-030-79393-7_3">10.1007/978-3-030-79393-7_3</a>'
  apa: Banholzer, S., Gebken, B., Dellnitz, M., Peitz, S., &#38; Volkwein, S. (2022).
    ROM-Based Multiobjective Optimization of Elliptic PDEs via Numerical Continuation.
    In H. Michael, H. Roland, K. Christian, U. Michael, &#38; U. Stefan (Eds.), <i>Non-Smooth
    and Complementarity-Based Distributed Parameter Systems</i> (pp. 43–76). Springer.
    <a href="https://doi.org/10.1007/978-3-030-79393-7_3">https://doi.org/10.1007/978-3-030-79393-7_3</a>
  bibtex: '@inbook{Banholzer_Gebken_Dellnitz_Peitz_Volkwein_2022, place={Cham}, title={ROM-Based
    Multiobjective Optimization of Elliptic PDEs via Numerical Continuation}, DOI={<a
    href="https://doi.org/10.1007/978-3-030-79393-7_3">10.1007/978-3-030-79393-7_3</a>},
    booktitle={Non-Smooth and Complementarity-Based Distributed Parameter Systems},
    publisher={Springer}, author={Banholzer, Stefan and Gebken, Bennet and Dellnitz,
    Michael and Peitz, Sebastian and Volkwein, Stefan}, editor={Michael, Hintermüller
    and Roland, Herzog and Christian, Kanzow and Michael, Ulbrich and Stefan, Ulbrich},
    year={2022}, pages={43–76} }'
  chicago: 'Banholzer, Stefan, Bennet Gebken, Michael Dellnitz, Sebastian Peitz, and
    Stefan Volkwein. “ROM-Based Multiobjective Optimization of Elliptic PDEs via Numerical
    Continuation.” In <i>Non-Smooth and Complementarity-Based Distributed Parameter
    Systems</i>, edited by Hintermüller Michael, Herzog Roland, Kanzow Christian,
    Ulbrich Michael, and Ulbrich Stefan, 43–76. Cham: Springer, 2022. <a href="https://doi.org/10.1007/978-3-030-79393-7_3">https://doi.org/10.1007/978-3-030-79393-7_3</a>.'
  ieee: 'S. Banholzer, B. Gebken, M. Dellnitz, S. Peitz, and S. Volkwein, “ROM-Based
    Multiobjective Optimization of Elliptic PDEs via Numerical Continuation,” in <i>Non-Smooth
    and Complementarity-Based Distributed Parameter Systems</i>, H. Michael, H. Roland,
    K. Christian, U. Michael, and U. Stefan, Eds. Cham: Springer, 2022, pp. 43–76.'
  mla: Banholzer, Stefan, et al. “ROM-Based Multiobjective Optimization of Elliptic
    PDEs via Numerical Continuation.” <i>Non-Smooth and Complementarity-Based Distributed
    Parameter Systems</i>, edited by Hintermüller Michael et al., Springer, 2022,
    pp. 43–76, doi:<a href="https://doi.org/10.1007/978-3-030-79393-7_3">10.1007/978-3-030-79393-7_3</a>.
  short: 'S. Banholzer, B. Gebken, M. Dellnitz, S. Peitz, S. Volkwein, in: H. Michael,
    H. Roland, K. Christian, U. Michael, U. Stefan (Eds.), Non-Smooth and Complementarity-Based
    Distributed Parameter Systems, Springer, Cham, 2022, pp. 43–76.'
date_created: 2020-03-13T12:45:31Z
date_updated: 2022-03-14T13:04:51Z
department:
- _id: '101'
- _id: '655'
doi: 10.1007/978-3-030-79393-7_3
editor:
- first_name: Hintermüller
  full_name: Michael, Hintermüller
  last_name: Michael
- first_name: Herzog
  full_name: Roland, Herzog
  last_name: Roland
- first_name: Kanzow
  full_name: Christian, Kanzow
  last_name: Christian
- first_name: Ulbrich
  full_name: Michael, Ulbrich
  last_name: Michael
- first_name: Ulbrich
  full_name: Stefan, Ulbrich
  last_name: Stefan
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/pdf/1906.09075.pdf
oa: '1'
page: 43-76
place: Cham
publication: Non-Smooth and Complementarity-Based Distributed Parameter Systems
publication_identifier:
  isbn:
  - 978-3-030-79392-0
publisher: Springer
status: public
title: ROM-Based Multiobjective Optimization of Elliptic PDEs via Numerical Continuation
type: book_chapter
user_id: '47427'
year: '2022'
...
---
_id: '30294'
abstract:
- lang: eng
  text: With the ever increasing capabilities of sensors and controllers, autonomous
    driving is quickly becoming a reality. This disruptive change in the automotive
    industry poses major challenges for manufacturers as well as suppliers as entirely
    new design and testing strategies have to be developed to remain competitive.
    Most importantly, the complexity of autonomously driving vehicles in a complex,
    uncertain, and safety-critical environment requires new testing procedures to
    cover the almost infinite range of potential scenarios.
author:
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
- first_name: Sebastian
  full_name: Bannenberg, Sebastian
  last_name: Bannenberg
citation:
  ama: 'Peitz S, Dellnitz M, Bannenberg S. Efficient Virtual Design and Testing of
    Autonomous Vehicles. In: Bock HG, Küfer K-H, Maas P, Milde A, Schulz V, eds. <i>German
    Success Stories in Industrial Mathematics</i>. Vol 35. Mathematics in Industry.
    Springer International Publishing; 2022. doi:<a href="https://doi.org/10.1007/978-3-030-81455-7_23">10.1007/978-3-030-81455-7_23</a>'
  apa: Peitz, S., Dellnitz, M., &#38; Bannenberg, S. (2022). Efficient Virtual Design
    and Testing of Autonomous Vehicles. In H. G. Bock, K.-H. Küfer, P. Maas, A. Milde,
    &#38; V. Schulz (Eds.), <i>German Success Stories in Industrial Mathematics</i>
    (Vol. 35). Springer International Publishing. <a href="https://doi.org/10.1007/978-3-030-81455-7_23">https://doi.org/10.1007/978-3-030-81455-7_23</a>
  bibtex: '@inbook{Peitz_Dellnitz_Bannenberg_2022, place={Cham}, series={Mathematics
    in Industry}, title={Efficient Virtual Design and Testing of Autonomous Vehicles},
    volume={35}, DOI={<a href="https://doi.org/10.1007/978-3-030-81455-7_23">10.1007/978-3-030-81455-7_23</a>},
    booktitle={German Success Stories in Industrial Mathematics}, publisher={Springer
    International Publishing}, author={Peitz, Sebastian and Dellnitz, Michael and
    Bannenberg, Sebastian}, editor={Bock, H. G. and Küfer, K.-H. and Maas, P. and
    Milde, A. and Schulz, V.}, year={2022}, collection={Mathematics in Industry} }'
  chicago: 'Peitz, Sebastian, Michael Dellnitz, and Sebastian Bannenberg. “Efficient
    Virtual Design and Testing of Autonomous Vehicles.” In <i>German Success Stories
    in Industrial Mathematics</i>, edited by H. G. Bock, K.-H. Küfer, P. Maas, A.
    Milde, and V. Schulz, Vol. 35. Mathematics in Industry. Cham: Springer International
    Publishing, 2022. <a href="https://doi.org/10.1007/978-3-030-81455-7_23">https://doi.org/10.1007/978-3-030-81455-7_23</a>.'
  ieee: 'S. Peitz, M. Dellnitz, and S. Bannenberg, “Efficient Virtual Design and Testing
    of Autonomous Vehicles,” in <i>German Success Stories in Industrial Mathematics</i>,
    vol. 35, H. G. Bock, K.-H. Küfer, P. Maas, A. Milde, and V. Schulz, Eds. Cham:
    Springer International Publishing, 2022.'
  mla: Peitz, Sebastian, et al. “Efficient Virtual Design and Testing of Autonomous
    Vehicles.” <i>German Success Stories in Industrial Mathematics</i>, edited by
    H. G. Bock et al., vol. 35, Springer International Publishing, 2022, doi:<a href="https://doi.org/10.1007/978-3-030-81455-7_23">10.1007/978-3-030-81455-7_23</a>.
  short: 'S. Peitz, M. Dellnitz, S. Bannenberg, in: H.G. Bock, K.-H. Küfer, P. Maas,
    A. Milde, V. Schulz (Eds.), German Success Stories in Industrial Mathematics,
    Springer International Publishing, Cham, 2022.'
date_created: 2022-03-14T07:32:41Z
date_updated: 2022-03-14T07:42:01Z
department:
- _id: '101'
- _id: '655'
doi: 10.1007/978-3-030-81455-7_23
editor:
- first_name: H. G.
  full_name: Bock, H. G.
  last_name: Bock
- first_name: K.-H.
  full_name: Küfer, K.-H.
  last_name: Küfer
- first_name: P.
  full_name: Maas, P.
  last_name: Maas
- first_name: A.
  full_name: Milde, A.
  last_name: Milde
- first_name: V.
  full_name: Schulz, V.
  last_name: Schulz
intvolume: '        35'
language:
- iso: eng
place: Cham
publication: German Success Stories in Industrial Mathematics
publication_identifier:
  isbn:
  - '9783030814540'
  - '9783030814557'
  issn:
  - 1612-3956
  - 2198-3283
publication_status: published
publisher: Springer International Publishing
series_title: Mathematics in Industry
status: public
title: Efficient Virtual Design and Testing of Autonomous Vehicles
type: book_chapter
user_id: '47427'
volume: 35
year: '2022'
...
---
_id: '29673'
abstract:
- lang: eng
  text: Koopman operator theory has been successfully applied to problems from various
    research areas such as fluid dynamics, molecular dynamics, climate science, engineering,
    and biology. Applications include detecting metastable or coherent sets, coarse-graining,
    system identification, and control. There is an intricate connection between dynamical
    systems driven by stochastic differential equations and quantum mechanics. In
    this paper, we compare the ground-state transformation and Nelson's stochastic
    mechanics and demonstrate how data-driven methods developed for the approximation
    of the Koopman operator can be used to analyze quantum physics problems. Moreover,
    we exploit the relationship between Schrödinger operators and stochastic control
    problems to show that modern data-driven methods for stochastic control can be
    used to solve the stationary or imaginary-time Schrödinger equation. Our findings
    open up a new avenue towards solving Schrödinger's equation using recently developed
    tools from data science.
author:
- first_name: Stefan
  full_name: Klus, Stefan
  last_name: Klus
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: 'Klus S, Nüske F, Peitz S. Koopman analysis of quantum systems. <i>Journal
    of Physics A: Mathematical and Theoretical</i>. 2022;55(31):314002. doi:<a href="https://doi.org/10.1088/1751-8121/ac7d22">10.1088/1751-8121/ac7d22</a>'
  apa: 'Klus, S., Nüske, F., &#38; Peitz, S. (2022). Koopman analysis of quantum systems.
    <i>Journal of Physics A: Mathematical and Theoretical</i>, <i>55</i>(31), 314002.
    <a href="https://doi.org/10.1088/1751-8121/ac7d22">https://doi.org/10.1088/1751-8121/ac7d22</a>'
  bibtex: '@article{Klus_Nüske_Peitz_2022, title={Koopman analysis of quantum systems},
    volume={55}, DOI={<a href="https://doi.org/10.1088/1751-8121/ac7d22">10.1088/1751-8121/ac7d22</a>},
    number={31}, journal={Journal of Physics A: Mathematical and Theoretical}, publisher={IOP
    Publishing Ltd.}, author={Klus, Stefan and Nüske, Feliks and Peitz, Sebastian},
    year={2022}, pages={314002} }'
  chicago: 'Klus, Stefan, Feliks Nüske, and Sebastian Peitz. “Koopman Analysis of
    Quantum Systems.” <i>Journal of Physics A: Mathematical and Theoretical</i> 55,
    no. 31 (2022): 314002. <a href="https://doi.org/10.1088/1751-8121/ac7d22">https://doi.org/10.1088/1751-8121/ac7d22</a>.'
  ieee: 'S. Klus, F. Nüske, and S. Peitz, “Koopman analysis of quantum systems,” <i>Journal
    of Physics A: Mathematical and Theoretical</i>, vol. 55, no. 31, p. 314002, 2022,
    doi: <a href="https://doi.org/10.1088/1751-8121/ac7d22">10.1088/1751-8121/ac7d22</a>.'
  mla: 'Klus, Stefan, et al. “Koopman Analysis of Quantum Systems.” <i>Journal of
    Physics A: Mathematical and Theoretical</i>, vol. 55, no. 31, IOP Publishing Ltd.,
    2022, p. 314002, doi:<a href="https://doi.org/10.1088/1751-8121/ac7d22">10.1088/1751-8121/ac7d22</a>.'
  short: 'S. Klus, F. Nüske, S. Peitz, Journal of Physics A: Mathematical and Theoretical
    55 (2022) 314002.'
date_created: 2022-01-31T09:49:40Z
date_updated: 2022-07-18T14:26:41Z
department:
- _id: '655'
- _id: '101'
doi: 10.1088/1751-8121/ac7d22
external_id:
  arxiv:
  - '2201.12062'
intvolume: '        55'
issue: '31'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://iopscience.iop.org/article/10.1088/1751-8121/ac7d22/pdf
oa: '1'
page: '314002'
publication: 'Journal of Physics A: Mathematical and Theoretical'
publication_status: published
publisher: IOP Publishing Ltd.
status: public
title: Koopman analysis of quantum systems
type: journal_article
user_id: '47427'
volume: 55
year: '2022'
...
---
_id: '34618'
abstract:
- lang: eng
  text: "In this article, we show how second-order derivative information can be\r\nincorporated
    into gradient sampling methods for nonsmooth optimization. The\r\nsecond-order
    information we consider is essentially the set of coefficients of\r\nall second-order
    Taylor expansions of the objective in a closed ball around a\r\ngiven point. Based
    on this concept, we define a model of the objective as the\r\nmaximum of these
    Taylor expansions. Iteratively minimizing this model\r\n(constrained to the closed
    ball) results in a simple descent method, for which\r\nwe prove convergence to
    minimal points in case the objective is convex. To\r\nobtain an implementable
    method, we construct an approximation scheme for the\r\nsecond-order information
    based on sampling objective values, gradients and\r\nHessian matrices at finitely
    many points. Using a set of test problems, we\r\ncompare the resulting method
    to five other available solvers. Considering the\r\nnumber of function evaluations,
    the results suggest that the method we propose\r\nis superior to the standard
    gradient sampling method, and competitive compared\r\nto other methods."
author:
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
citation:
  ama: Gebken B. Using second-order information in gradient sampling methods for 
    nonsmooth optimization. <i>arXiv:221004579</i>. Published online 2022.
  apa: Gebken, B. (2022). Using second-order information in gradient sampling methods
    for  nonsmooth optimization. In <i>arXiv:2210.04579</i>.
  bibtex: '@article{Gebken_2022, title={Using second-order information in gradient
    sampling methods for  nonsmooth optimization}, journal={arXiv:2210.04579}, author={Gebken,
    Bennet}, year={2022} }'
  chicago: Gebken, Bennet. “Using Second-Order Information in Gradient Sampling Methods
    for  Nonsmooth Optimization.” <i>ArXiv:2210.04579</i>, 2022.
  ieee: B. Gebken, “Using second-order information in gradient sampling methods for 
    nonsmooth optimization,” <i>arXiv:2210.04579</i>. 2022.
  mla: Gebken, Bennet. “Using Second-Order Information in Gradient Sampling Methods
    for  Nonsmooth Optimization.” <i>ArXiv:2210.04579</i>, 2022.
  short: B. Gebken, ArXiv:2210.04579 (2022).
date_created: 2022-12-20T15:25:17Z
date_updated: 2022-12-20T15:28:54Z
department:
- _id: '101'
external_id:
  arxiv:
  - '2210.04579'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/pdf/2210.04579
oa: '1'
publication: arXiv:2210.04579
status: public
title: Using second-order information in gradient sampling methods for  nonsmooth
  optimization
type: preprint
user_id: '32643'
year: '2022'
...
---
_id: '31556'
abstract:
- lang: ger
  text: Mehrzieloptimierung behandelt Probleme, bei denen mehrere skalare Zielfunktionen
    simultan optimiert werden sollen. Ein Punkt ist in diesem Fall optimal, wenn es
    keinen anderen Punkt gibt, der mindestens genauso gut ist in allen Zielfunktionen
    und besser in mindestens einer Zielfunktion. Ein notwendiges Optimalitätskriterium
    lässt sich über Ableitungsinformationen erster Ordnung der Zielfunktionen herleiten.
    Die Menge der Punkte, die dieses notwendige Kriterium erfüllen, wird als Pareto-kritische
    Menge bezeichnet. Diese Arbeit enthält neue Resultate über Pareto-kritische Mengen
    für glatte und nicht-glatte Mehrzieloptimierungsprobleme, sowohl was deren Berechnung
    betrifft als auch deren Struktur. Im glatten Fall erfolgt die Berechnung über
    ein Fortsetzungsverfahren, im nichtglatten Fall über ein Abstiegsverfahren. Anschließend
    wird die Struktur des Randes der Pareto-kritischen Menge analysiert, welcher aus
    Pareto-kritischen Mengen kleinerer Subprobleme besteht. Schlussendlich werden
    inverse Probleme betrachtet, bei denen zu einer gegebenen Datenmenge ein Zielfunktionsvektor
    gefunden werden soll, für den die Datenpunkte kritisch sind.
- lang: eng
  text: Multiobjective optimization is concerned with the simultaneous optimization
    of multiple scalar-valued functions. In this case, a point is optimal if there
    is no other point that is at least as good in all objectives and better in at
    least one objective. A necessary condition for optimality can be derived based
    on first-order information of the objectives. The set of points that satisfy this
    necessary condition is called the Pareto critical set. This thesis presents new
    results about Pareto critical sets for smooth and nonsmooth multiobjective optimization
    problems, both in terms of their efficient computation and structural properties.
    In the smooth case they are computed via a continuation method and in the nonsmooth
    case via a descent method. Afterwards, the structure of the boundary of the Pareto
    critical set is analyzed, which consists of Pareto critical sets of smaller subproblems.
    Finally, inverse problems are considered, where a data set is given and an objective
    vector is sought for which the data points are critical.
author:
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
citation:
  ama: Gebken B. <i>Computation and Analysis of Pareto Critical Sets in Smooth and
    Nonsmooth Multiobjective Optimization</i>.; 2022. doi:<a href="https://doi.org/10.17619/UNIPB/1-1327">10.17619/UNIPB/1-1327</a>
  apa: Gebken, B. (2022). <i>Computation and analysis of Pareto critical sets in smooth
    and nonsmooth multiobjective optimization</i>. <a href="https://doi.org/10.17619/UNIPB/1-1327">https://doi.org/10.17619/UNIPB/1-1327</a>
  bibtex: '@book{Gebken_2022, title={Computation and analysis of Pareto critical sets
    in smooth and nonsmooth multiobjective optimization}, DOI={<a href="https://doi.org/10.17619/UNIPB/1-1327">10.17619/UNIPB/1-1327</a>},
    author={Gebken, Bennet}, year={2022} }'
  chicago: Gebken, Bennet. <i>Computation and Analysis of Pareto Critical Sets in
    Smooth and Nonsmooth Multiobjective Optimization</i>, 2022. <a href="https://doi.org/10.17619/UNIPB/1-1327">https://doi.org/10.17619/UNIPB/1-1327</a>.
  ieee: B. Gebken, <i>Computation and analysis of Pareto critical sets in smooth and
    nonsmooth multiobjective optimization</i>. 2022.
  mla: Gebken, Bennet. <i>Computation and Analysis of Pareto Critical Sets in Smooth
    and Nonsmooth Multiobjective Optimization</i>. 2022, doi:<a href="https://doi.org/10.17619/UNIPB/1-1327">10.17619/UNIPB/1-1327</a>.
  short: B. Gebken, Computation and Analysis of Pareto Critical Sets in Smooth and
    Nonsmooth Multiobjective Optimization, 2022.
date_created: 2022-06-01T06:48:08Z
date_updated: 2022-06-01T07:13:09Z
department:
- _id: '101'
doi: 10.17619/UNIPB/1-1327
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://digital.ub.uni-paderborn.de/hs/download/pdf/6531779
oa: '1'
status: public
supervisor:
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
title: Computation and analysis of Pareto critical sets in smooth and nonsmooth multiobjective
  optimization
type: dissertation
user_id: '32643'
year: '2022'
...
---
_id: '33150'
abstract:
- lang: eng
  text: In this article, we build on previous work to present an optimization algorithm
    for nonlinearly constrained multi-objective optimization problems. The algorithm
    combines a surrogate-assisted derivative-free trust-region approach with the filter
    method known from single-objective optimization. Instead of the true objective
    and constraint functions, so-called fully linear models are employed and we show
    how to deal with the gradient inexactness in the composite step setting, adapted
    from single-objective optimization as well. Under standard assumptions, we prove
    convergence of a subset of iterates to a quasi-stationary point and if constraint
    qualifications hold, then the limit point is also a KKT-point of the multi-objective
    problem.
author:
- first_name: Manuel Bastian
  full_name: Berkemeier, Manuel Bastian
  id: '51701'
  last_name: Berkemeier
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: Berkemeier MB, Peitz S. Multi-Objective Trust-Region Filter Method for Nonlinear
    Constraints using Inexact Gradients. <i>arXiv:220812094</i>. Published online
    2022.
  apa: Berkemeier, M. B., &#38; Peitz, S. (2022). Multi-Objective Trust-Region Filter
    Method for Nonlinear Constraints using Inexact Gradients. In <i>arXiv:2208.12094</i>.
  bibtex: '@article{Berkemeier_Peitz_2022, title={Multi-Objective Trust-Region Filter
    Method for Nonlinear Constraints using Inexact Gradients}, journal={arXiv:2208.12094},
    author={Berkemeier, Manuel Bastian and Peitz, Sebastian}, year={2022} }'
  chicago: Berkemeier, Manuel Bastian, and Sebastian Peitz. “Multi-Objective Trust-Region
    Filter Method for Nonlinear Constraints Using Inexact Gradients.” <i>ArXiv:2208.12094</i>,
    2022.
  ieee: M. B. Berkemeier and S. Peitz, “Multi-Objective Trust-Region Filter Method
    for Nonlinear Constraints using Inexact Gradients,” <i>arXiv:2208.12094</i>. 2022.
  mla: Berkemeier, Manuel Bastian, and Sebastian Peitz. “Multi-Objective Trust-Region
    Filter Method for Nonlinear Constraints Using Inexact Gradients.” <i>ArXiv:2208.12094</i>,
    2022.
  short: M.B. Berkemeier, S. Peitz, ArXiv:2208.12094 (2022).
date_created: 2022-08-26T06:08:06Z
date_updated: 2022-08-26T06:12:10Z
department:
- _id: '101'
- _id: '655'
external_id:
  arxiv:
  - '2208.12094'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/pdf/2208.12094
oa: '1'
publication: arXiv:2208.12094
status: public
title: Multi-Objective Trust-Region Filter Method for Nonlinear Constraints using
  Inexact Gradients
type: preprint
user_id: '47427'
year: '2022'
...
---
_id: '20731'
abstract:
- lang: eng
  text: We present a novel algorithm that allows us to gain detailed insight into
    the effects of sparsity in linear and nonlinear optimization, which is of great
    importance in many scientific areas such as image and signal processing, medical
    imaging, compressed sensing, and machine learning (e.g., for the training of neural
    networks). Sparsity is an important feature to ensure robustness against noisy
    data, but also to find models that are interpretable and easy to analyze due to
    the small number of relevant terms. It is common practice to enforce sparsity
    by adding the ℓ1-norm as a weighted penalty term. In order to gain a better understanding
    and to allow for an informed model selection, we directly solve the corresponding
    multiobjective optimization problem (MOP) that arises when we minimize the main
    objective and the ℓ1-norm simultaneously. As this MOP is in general non-convex
    for nonlinear objectives, the weighting method will fail to provide all optimal
    compromises. To avoid this issue, we present a continuation method which is specifically
    tailored to MOPs with two objective functions one of which is the ℓ1-norm. Our
    method can be seen as a generalization of well-known homotopy methods for linear
    regression problems to the nonlinear case. Several numerical examples - including
    neural network training - demonstrate our theoretical findings and the additional
    insight that can be gained by this multiobjective approach.
article_type: original
author:
- first_name: Katharina
  full_name: Bieker, Katharina
  id: '32829'
  last_name: Bieker
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: Bieker K, Gebken B, Peitz S. On the Treatment of Optimization Problems with
    L1 Penalty Terms via Multiobjective Continuation. <i>IEEE Transactions on Pattern
    Analysis and Machine Intelligence</i>. 2022;44(11):7797-7808. doi:<a href="https://doi.org/10.1109/TPAMI.2021.3114962">10.1109/TPAMI.2021.3114962</a>
  apa: Bieker, K., Gebken, B., &#38; Peitz, S. (2022). On the Treatment of Optimization
    Problems with L1 Penalty Terms via Multiobjective Continuation. <i>IEEE Transactions
    on Pattern Analysis and Machine Intelligence</i>, <i>44</i>(11), 7797–7808. <a
    href="https://doi.org/10.1109/TPAMI.2021.3114962">https://doi.org/10.1109/TPAMI.2021.3114962</a>
  bibtex: '@article{Bieker_Gebken_Peitz_2022, title={On the Treatment of Optimization
    Problems with L1 Penalty Terms via Multiobjective Continuation}, volume={44},
    DOI={<a href="https://doi.org/10.1109/TPAMI.2021.3114962">10.1109/TPAMI.2021.3114962</a>},
    number={11}, journal={IEEE Transactions on Pattern Analysis and Machine Intelligence},
    publisher={IEEE}, author={Bieker, Katharina and Gebken, Bennet and Peitz, Sebastian},
    year={2022}, pages={7797–7808} }'
  chicago: 'Bieker, Katharina, Bennet Gebken, and Sebastian Peitz. “On the Treatment
    of Optimization Problems with L1 Penalty Terms via Multiobjective Continuation.”
    <i>IEEE Transactions on Pattern Analysis and Machine Intelligence</i> 44, no.
    11 (2022): 7797–7808. <a href="https://doi.org/10.1109/TPAMI.2021.3114962">https://doi.org/10.1109/TPAMI.2021.3114962</a>.'
  ieee: 'K. Bieker, B. Gebken, and S. Peitz, “On the Treatment of Optimization Problems
    with L1 Penalty Terms via Multiobjective Continuation,” <i>IEEE Transactions on
    Pattern Analysis and Machine Intelligence</i>, vol. 44, no. 11, pp. 7797–7808,
    2022, doi: <a href="https://doi.org/10.1109/TPAMI.2021.3114962">10.1109/TPAMI.2021.3114962</a>.'
  mla: Bieker, Katharina, et al. “On the Treatment of Optimization Problems with L1
    Penalty Terms via Multiobjective Continuation.” <i>IEEE Transactions on Pattern
    Analysis and Machine Intelligence</i>, vol. 44, no. 11, IEEE, 2022, pp. 7797–808,
    doi:<a href="https://doi.org/10.1109/TPAMI.2021.3114962">10.1109/TPAMI.2021.3114962</a>.
  short: K. Bieker, B. Gebken, S. Peitz, IEEE Transactions on Pattern Analysis and
    Machine Intelligence 44 (2022) 7797–7808.
date_created: 2020-12-15T07:46:36Z
date_updated: 2022-10-21T12:27:16Z
ddc:
- '510'
department:
- _id: '101'
- _id: '530'
- _id: '655'
doi: 10.1109/TPAMI.2021.3114962
file:
- access_level: closed
  content_type: application/pdf
  creator: speitz
  date_created: 2021-09-25T11:59:15Z
  date_updated: 2021-09-25T11:59:15Z
  file_id: '25040'
  file_name: On_the_Treatment_of_Optimization_Problems_with_L1_Penalty_Terms_via_Multiobjective_Continuation.pdf
  file_size: 7990831
  relation: main_file
  success: 1
file_date_updated: 2021-09-25T11:59:15Z
has_accepted_license: '1'
intvolume: '        44'
issue: '11'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9547772
oa: '1'
page: 7797-7808
publication: IEEE Transactions on Pattern Analysis and Machine Intelligence
publication_status: epub_ahead
publisher: IEEE
status: public
title: On the Treatment of Optimization Problems with L1 Penalty Terms via Multiobjective
  Continuation
type: journal_article
user_id: '47427'
volume: 44
year: '2022'
...
---
_id: '24169'
article_number: '133018'
author:
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Patrick
  full_name: Gelß, Patrick
  last_name: Gelß
- first_name: Stefan
  full_name: Klus, Stefan
  last_name: Klus
- first_name: Cecilia
  full_name: Clementi, Cecilia
  last_name: Clementi
citation:
  ama: 'Nüske F, Gelß P, Klus S, Clementi C. Tensor-based computation of metastable
    and coherent sets. <i>Physica D: Nonlinear Phenomena</i>. Published online 2021.
    doi:<a href="https://doi.org/10.1016/j.physd.2021.133018">10.1016/j.physd.2021.133018</a>'
  apa: 'Nüske, F., Gelß, P., Klus, S., &#38; Clementi, C. (2021). Tensor-based computation
    of metastable and coherent sets. <i>Physica D: Nonlinear Phenomena</i>, Article
    133018. <a href="https://doi.org/10.1016/j.physd.2021.133018">https://doi.org/10.1016/j.physd.2021.133018</a>'
  bibtex: '@article{Nüske_Gelß_Klus_Clementi_2021, title={Tensor-based computation
    of metastable and coherent sets}, DOI={<a href="https://doi.org/10.1016/j.physd.2021.133018">10.1016/j.physd.2021.133018</a>},
    number={133018}, journal={Physica D: Nonlinear Phenomena}, author={Nüske, Feliks
    and Gelß, Patrick and Klus, Stefan and Clementi, Cecilia}, year={2021} }'
  chicago: 'Nüske, Feliks, Patrick Gelß, Stefan Klus, and Cecilia Clementi. “Tensor-Based
    Computation of Metastable and Coherent Sets.” <i>Physica D: Nonlinear Phenomena</i>,
    2021. <a href="https://doi.org/10.1016/j.physd.2021.133018">https://doi.org/10.1016/j.physd.2021.133018</a>.'
  ieee: 'F. Nüske, P. Gelß, S. Klus, and C. Clementi, “Tensor-based computation of
    metastable and coherent sets,” <i>Physica D: Nonlinear Phenomena</i>, Art. no.
    133018, 2021, doi: <a href="https://doi.org/10.1016/j.physd.2021.133018">10.1016/j.physd.2021.133018</a>.'
  mla: 'Nüske, Feliks, et al. “Tensor-Based Computation of Metastable and Coherent
    Sets.” <i>Physica D: Nonlinear Phenomena</i>, 133018, 2021, doi:<a href="https://doi.org/10.1016/j.physd.2021.133018">10.1016/j.physd.2021.133018</a>.'
  short: 'F. Nüske, P. Gelß, S. Klus, C. Clementi, Physica D: Nonlinear Phenomena
    (2021).'
date_created: 2021-09-12T08:51:24Z
date_updated: 2022-01-06T06:56:08Z
department:
- _id: '101'
doi: 10.1016/j.physd.2021.133018
language:
- iso: eng
publication: 'Physica D: Nonlinear Phenomena'
publication_identifier:
  issn:
  - 0167-2789
publication_status: published
status: public
title: Tensor-based computation of metastable and coherent sets
type: journal_article
user_id: '81513'
year: '2021'
...
---
_id: '24170'
article_number: '045016'
author:
- first_name: Stefan
  full_name: Klus, Stefan
  last_name: Klus
- first_name: Patrick
  full_name: Gelß, Patrick
  last_name: Gelß
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Frank
  full_name: Noé, Frank
  last_name: Noé
citation:
  ama: 'Klus S, Gelß P, Nüske F, Noé F. Symmetric and antisymmetric kernels for machine
    learning problems in quantum physics and chemistry. <i>Machine Learning: Science
    and Technology</i>. Published online 2021. doi:<a href="https://doi.org/10.1088/2632-2153/ac14ad">10.1088/2632-2153/ac14ad</a>'
  apa: 'Klus, S., Gelß, P., Nüske, F., &#38; Noé, F. (2021). Symmetric and antisymmetric
    kernels for machine learning problems in quantum physics and chemistry. <i>Machine
    Learning: Science and Technology</i>, Article 045016. <a href="https://doi.org/10.1088/2632-2153/ac14ad">https://doi.org/10.1088/2632-2153/ac14ad</a>'
  bibtex: '@article{Klus_Gelß_Nüske_Noé_2021, title={Symmetric and antisymmetric kernels
    for machine learning problems in quantum physics and chemistry}, DOI={<a href="https://doi.org/10.1088/2632-2153/ac14ad">10.1088/2632-2153/ac14ad</a>},
    number={045016}, journal={Machine Learning: Science and Technology}, author={Klus,
    Stefan and Gelß, Patrick and Nüske, Feliks and Noé, Frank}, year={2021} }'
  chicago: 'Klus, Stefan, Patrick Gelß, Feliks Nüske, and Frank Noé. “Symmetric and
    Antisymmetric Kernels for Machine Learning Problems in Quantum Physics and Chemistry.”
    <i>Machine Learning: Science and Technology</i>, 2021. <a href="https://doi.org/10.1088/2632-2153/ac14ad">https://doi.org/10.1088/2632-2153/ac14ad</a>.'
  ieee: 'S. Klus, P. Gelß, F. Nüske, and F. Noé, “Symmetric and antisymmetric kernels
    for machine learning problems in quantum physics and chemistry,” <i>Machine Learning:
    Science and Technology</i>, Art. no. 045016, 2021, doi: <a href="https://doi.org/10.1088/2632-2153/ac14ad">10.1088/2632-2153/ac14ad</a>.'
  mla: 'Klus, Stefan, et al. “Symmetric and Antisymmetric Kernels for Machine Learning
    Problems in Quantum Physics and Chemistry.” <i>Machine Learning: Science and Technology</i>,
    045016, 2021, doi:<a href="https://doi.org/10.1088/2632-2153/ac14ad">10.1088/2632-2153/ac14ad</a>.'
  short: 'S. Klus, P. Gelß, F. Nüske, F. Noé, Machine Learning: Science and Technology
    (2021).'
date_created: 2021-09-12T08:52:57Z
date_updated: 2022-01-06T06:56:08Z
department:
- _id: '101'
doi: 10.1088/2632-2153/ac14ad
language:
- iso: eng
publication: 'Machine Learning: Science and Technology'
publication_identifier:
  issn:
  - 2632-2153
publication_status: published
status: public
title: Symmetric and antisymmetric kernels for machine learning problems in quantum
  physics and chemistry
type: journal_article
user_id: '81513'
year: '2021'
...
---
_id: '21195'
author:
- first_name: Christian
  full_name: Goelz, Christian
  last_name: Goelz
- first_name: Karin
  full_name: Mora, Karin
  last_name: Mora
- first_name: Julia Kristin
  full_name: Stroehlein, Julia Kristin
  last_name: Stroehlein
- first_name: Franziska Katharina
  full_name: Haase, Franziska Katharina
  last_name: Haase
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
- first_name: Claus
  full_name: Reinsberger, Claus
  last_name: Reinsberger
- first_name: Solveig
  full_name: Vieluf, Solveig
  last_name: Vieluf
citation:
  ama: Goelz C, Mora K, Stroehlein JK, et al. Electrophysiological signatures of dedifferentiation
    differ between fit and less fit older adults. <i>Cognitive Neurodynamics</i>.
    2021. doi:<a href="https://doi.org/10.1007/s11571-020-09656-9">10.1007/s11571-020-09656-9</a>
  apa: Goelz, C., Mora, K., Stroehlein, J. K., Haase, F. K., Dellnitz, M., Reinsberger,
    C., &#38; Vieluf, S. (2021). Electrophysiological signatures of dedifferentiation
    differ between fit and less fit older adults. <i>Cognitive Neurodynamics</i>.
    <a href="https://doi.org/10.1007/s11571-020-09656-9">https://doi.org/10.1007/s11571-020-09656-9</a>
  bibtex: '@article{Goelz_Mora_Stroehlein_Haase_Dellnitz_Reinsberger_Vieluf_2021,
    title={Electrophysiological signatures of dedifferentiation differ between fit
    and less fit older adults}, DOI={<a href="https://doi.org/10.1007/s11571-020-09656-9">10.1007/s11571-020-09656-9</a>},
    journal={Cognitive Neurodynamics}, author={Goelz, Christian and Mora, Karin and
    Stroehlein, Julia Kristin and Haase, Franziska Katharina and Dellnitz, Michael
    and Reinsberger, Claus and Vieluf, Solveig}, year={2021} }'
  chicago: Goelz, Christian, Karin Mora, Julia Kristin Stroehlein, Franziska Katharina
    Haase, Michael Dellnitz, Claus Reinsberger, and Solveig Vieluf. “Electrophysiological
    Signatures of Dedifferentiation Differ between Fit and Less Fit Older Adults.”
    <i>Cognitive Neurodynamics</i>, 2021. <a href="https://doi.org/10.1007/s11571-020-09656-9">https://doi.org/10.1007/s11571-020-09656-9</a>.
  ieee: C. Goelz <i>et al.</i>, “Electrophysiological signatures of dedifferentiation
    differ between fit and less fit older adults,” <i>Cognitive Neurodynamics</i>,
    2021.
  mla: Goelz, Christian, et al. “Electrophysiological Signatures of Dedifferentiation
    Differ between Fit and Less Fit Older Adults.” <i>Cognitive Neurodynamics</i>,
    2021, doi:<a href="https://doi.org/10.1007/s11571-020-09656-9">10.1007/s11571-020-09656-9</a>.
  short: C. Goelz, K. Mora, J.K. Stroehlein, F.K. Haase, M. Dellnitz, C. Reinsberger,
    S. Vieluf, Cognitive Neurodynamics (2021).
date_created: 2021-02-08T13:16:07Z
date_updated: 2022-01-06T06:54:49Z
department:
- _id: '101'
doi: 10.1007/s11571-020-09656-9
language:
- iso: eng
main_file_link:
- url: https://link.springer.com/content/pdf/10.1007/s11571-020-09656-9.pdf
publication: Cognitive Neurodynamics
status: public
title: Electrophysiological signatures of dedifferentiation differ between fit and
  less fit older adults
type: journal_article
user_id: '32643'
year: '2021'
...
---
_id: '21337'
abstract:
- lang: eng
  text: "We present a flexible trust region descend algorithm for unconstrained and\r\nconvexly
    constrained multiobjective optimization problems. It is targeted at\r\nheterogeneous
    and expensive problems, i.e., problems that have at least one\r\nobjective function
    that is computationally expensive. The method is\r\nderivative-free in the sense
    that neither need derivative information be\r\navailable for the expensive objectives
    nor are gradients approximated using\r\nrepeated function evaluations as is the
    case in finite-difference methods.\r\nInstead, a multiobjective trust region approach
    is used that works similarly to\r\nits well-known scalar pendants. Local surrogate
    models constructed from\r\nevaluation data of the true objective functions are
    employed to compute\r\npossible descent directions. In contrast to existing multiobjective
    trust\r\nregion algorithms, these surrogates are not polynomial but carefully\r\nconstructed
    radial basis function networks. This has the important advantage\r\nthat the number
    of data points scales linearly with the parameter space\r\ndimension. The local
    models qualify as fully linear and the corresponding\r\ngeneral scalar framework
    is adapted for problems with multiple objectives.\r\nConvergence to Pareto critical
    points is proven and numerical examples\r\nillustrate our findings."
article_number: '31'
author:
- first_name: Manuel Bastian
  full_name: Berkemeier, Manuel Bastian
  id: '51701'
  last_name: Berkemeier
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: Berkemeier MB, Peitz S. Derivative-Free Multiobjective Trust Region Descent
    Method Using Radial  Basis Function Surrogate Models. <i>Mathematical and Computational
    Applications</i>. 2021;26(2). doi:<a href="https://doi.org/10.3390/mca26020031">10.3390/mca26020031</a>
  apa: Berkemeier, M. B., &#38; Peitz, S. (2021). Derivative-Free Multiobjective Trust
    Region Descent Method Using Radial  Basis Function Surrogate Models. <i>Mathematical
    and Computational Applications</i>, <i>26</i>(2). <a href="https://doi.org/10.3390/mca26020031">https://doi.org/10.3390/mca26020031</a>
  bibtex: '@article{Berkemeier_Peitz_2021, title={Derivative-Free Multiobjective Trust
    Region Descent Method Using Radial  Basis Function Surrogate Models}, volume={26},
    DOI={<a href="https://doi.org/10.3390/mca26020031">10.3390/mca26020031</a>}, number={231},
    journal={Mathematical and Computational Applications}, author={Berkemeier, Manuel
    Bastian and Peitz, Sebastian}, year={2021} }'
  chicago: Berkemeier, Manuel Bastian, and Sebastian Peitz. “Derivative-Free Multiobjective
    Trust Region Descent Method Using Radial  Basis Function Surrogate Models.” <i>Mathematical
    and Computational Applications</i> 26, no. 2 (2021). <a href="https://doi.org/10.3390/mca26020031">https://doi.org/10.3390/mca26020031</a>.
  ieee: M. B. Berkemeier and S. Peitz, “Derivative-Free Multiobjective Trust Region
    Descent Method Using Radial  Basis Function Surrogate Models,” <i>Mathematical
    and Computational Applications</i>, vol. 26, no. 2, 2021.
  mla: Berkemeier, Manuel Bastian, and Sebastian Peitz. “Derivative-Free Multiobjective
    Trust Region Descent Method Using Radial  Basis Function Surrogate Models.” <i>Mathematical
    and Computational Applications</i>, vol. 26, no. 2, 31, 2021, doi:<a href="https://doi.org/10.3390/mca26020031">10.3390/mca26020031</a>.
  short: M.B. Berkemeier, S. Peitz, Mathematical and Computational Applications 26
    (2021).
date_created: 2021-03-01T10:46:48Z
date_updated: 2022-01-06T06:54:55Z
department:
- _id: '101'
- _id: '655'
doi: 10.3390/mca26020031
intvolume: '        26'
issue: '2'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.mdpi.com/2297-8747/26/2/31/pdf
oa: '1'
publication: Mathematical and Computational Applications
publication_identifier:
  eissn:
  - 2297-8747
publication_status: published
status: public
title: Derivative-Free Multiobjective Trust Region Descent Method Using Radial  Basis
  Function Surrogate Models
type: journal_article
user_id: '47427'
volume: 26
year: '2021'
...
---
_id: '21820'
abstract:
- lang: eng
  text: <jats:p>The reduction of high-dimensional systems to effective models on a
    smaller set of variables is an essential task in many areas of science. For stochastic
    dynamics governed by diffusion processes, a general procedure to find effective
    equations is the conditioning approach. In this paper, we are interested in the
    spectrum of the generator of the resulting effective dynamics, and how it compares
    to the spectrum of the full generator. We prove a new relative error bound in
    terms of the eigenfunction approximation error for reversible systems. We also
    present numerical examples indicating that, if Kramers–Moyal (KM) type approximations
    are used to compute the spectrum of the reduced generator, it seems largely insensitive
    to the time window used for the KM estimators. We analyze the implications of
    these observations for systems driven by underdamped Langevin dynamics, and show
    how meaningful effective dynamics can be defined in this setting.</jats:p>
article_number: '134'
author:
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Péter
  full_name: Koltai, Péter
  last_name: Koltai
- first_name: Lorenzo
  full_name: Boninsegna, Lorenzo
  last_name: Boninsegna
- first_name: Cecilia
  full_name: Clementi, Cecilia
  last_name: Clementi
citation:
  ama: Nüske F, Koltai P, Boninsegna L, Clementi C. Spectral Properties of Effective
    Dynamics from Conditional Expectations. <i>Entropy</i>. 2021. doi:<a href="https://doi.org/10.3390/e23020134">10.3390/e23020134</a>
  apa: Nüske, F., Koltai, P., Boninsegna, L., &#38; Clementi, C. (2021). Spectral
    Properties of Effective Dynamics from Conditional Expectations. <i>Entropy</i>.
    <a href="https://doi.org/10.3390/e23020134">https://doi.org/10.3390/e23020134</a>
  bibtex: '@article{Nüske_Koltai_Boninsegna_Clementi_2021, title={Spectral Properties
    of Effective Dynamics from Conditional Expectations}, DOI={<a href="https://doi.org/10.3390/e23020134">10.3390/e23020134</a>},
    number={134}, journal={Entropy}, author={Nüske, Feliks and Koltai, Péter and Boninsegna,
    Lorenzo and Clementi, Cecilia}, year={2021} }'
  chicago: Nüske, Feliks, Péter Koltai, Lorenzo Boninsegna, and Cecilia Clementi.
    “Spectral Properties of Effective Dynamics from Conditional Expectations.” <i>Entropy</i>,
    2021. <a href="https://doi.org/10.3390/e23020134">https://doi.org/10.3390/e23020134</a>.
  ieee: F. Nüske, P. Koltai, L. Boninsegna, and C. Clementi, “Spectral Properties
    of Effective Dynamics from Conditional Expectations,” <i>Entropy</i>, 2021.
  mla: Nüske, Feliks, et al. “Spectral Properties of Effective Dynamics from Conditional
    Expectations.” <i>Entropy</i>, 134, 2021, doi:<a href="https://doi.org/10.3390/e23020134">10.3390/e23020134</a>.
  short: F. Nüske, P. Koltai, L. Boninsegna, C. Clementi, Entropy (2021).
date_created: 2021-04-28T18:07:56Z
date_updated: 2022-01-06T06:55:16Z
department:
- _id: '101'
doi: 10.3390/e23020134
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.mdpi.com/1099-4300/23/2/134
oa: '1'
publication: Entropy
publication_identifier:
  issn:
  - 1099-4300
publication_status: published
status: public
title: Spectral Properties of Effective Dynamics from Conditional Expectations
type: journal_article
user_id: '81513'
year: '2021'
...
---
_id: '16867'
abstract:
- lang: eng
  text: "In this article, we present an efficient descent method for locally Lipschitz\r\ncontinuous
    multiobjective optimization problems (MOPs). The method is realized\r\nby combining
    a theoretical result regarding the computation of descent\r\ndirections for nonsmooth
    MOPs with a practical method to approximate the\r\nsubdifferentials of the objective
    functions. We show convergence to points\r\nwhich satisfy a necessary condition
    for Pareto optimality. Using a set of test\r\nproblems, we compare our method
    to the multiobjective proximal bundle method by\r\nM\\\"akel\\\"a. The results
    indicate that our method is competitive while being\r\neasier to implement. While
    the number of objective function evaluations is\r\nlarger, the overall number
    of subgradient evaluations is lower. Finally, we\r\nshow that our method can be
    combined with a subdivision algorithm to compute\r\nentire Pareto sets of nonsmooth
    MOPs."
author:
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: Gebken B, Peitz S. An efficient descent method for locally Lipschitz multiobjective
    optimization problems. <i>Journal of Optimization Theory and Applications</i>.
    2021;188:696-723. doi:<a href="https://doi.org/10.1007/s10957-020-01803-w">10.1007/s10957-020-01803-w</a>
  apa: Gebken, B., &#38; Peitz, S. (2021). An efficient descent method for locally
    Lipschitz multiobjective optimization problems. <i>Journal of Optimization Theory
    and Applications</i>, <i>188</i>, 696–723. <a href="https://doi.org/10.1007/s10957-020-01803-w">https://doi.org/10.1007/s10957-020-01803-w</a>
  bibtex: '@article{Gebken_Peitz_2021, title={An efficient descent method for locally
    Lipschitz multiobjective optimization problems}, volume={188}, DOI={<a href="https://doi.org/10.1007/s10957-020-01803-w">10.1007/s10957-020-01803-w</a>},
    journal={Journal of Optimization Theory and Applications}, author={Gebken, Bennet
    and Peitz, Sebastian}, year={2021}, pages={696–723} }'
  chicago: 'Gebken, Bennet, and Sebastian Peitz. “An Efficient Descent Method for
    Locally Lipschitz Multiobjective Optimization Problems.” <i>Journal of Optimization
    Theory and Applications</i> 188 (2021): 696–723. <a href="https://doi.org/10.1007/s10957-020-01803-w">https://doi.org/10.1007/s10957-020-01803-w</a>.'
  ieee: B. Gebken and S. Peitz, “An efficient descent method for locally Lipschitz
    multiobjective optimization problems,” <i>Journal of Optimization Theory and Applications</i>,
    vol. 188, pp. 696–723, 2021.
  mla: Gebken, Bennet, and Sebastian Peitz. “An Efficient Descent Method for Locally
    Lipschitz Multiobjective Optimization Problems.” <i>Journal of Optimization Theory
    and Applications</i>, vol. 188, 2021, pp. 696–723, doi:<a href="https://doi.org/10.1007/s10957-020-01803-w">10.1007/s10957-020-01803-w</a>.
  short: B. Gebken, S. Peitz, Journal of Optimization Theory and Applications 188
    (2021) 696–723.
date_created: 2020-04-27T09:11:22Z
date_updated: 2022-01-06T06:52:57Z
department:
- _id: '101'
doi: 10.1007/s10957-020-01803-w
intvolume: '       188'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://link.springer.com/content/pdf/10.1007/s10957-020-01803-w.pdf
oa: '1'
page: 696-723
publication: Journal of Optimization Theory and Applications
publication_status: published
status: public
title: An efficient descent method for locally Lipschitz multiobjective optimization
  problems
type: journal_article
user_id: '47427'
volume: 188
year: '2021'
...
---
_id: '16295'
abstract:
- lang: eng
  text: It is a challenging task to identify the objectives on which a certain decision
    was based, in particular if several, potentially conflicting criteria are equally
    important and a continuous set of optimal compromise decisions exists. This task
    can be understood as the inverse problem of multiobjective optimization, where
    the goal is to find the objective function vector of a given Pareto set. To this
    end, we present a method to construct the objective function vector of an unconstrained
    multiobjective optimization problem (MOP) such that the Pareto critical set contains
    a given set of data points with prescribed KKT multipliers. If such an MOP can
    not be found, then the method instead produces an MOP whose Pareto critical set
    is at least close to the data points. The key idea is to consider the objective
    function vector in the multiobjective KKT conditions as variable and then search
    for the objectives that minimize the Euclidean norm of the resulting system of
    equations. By expressing the objectives in a finite-dimensional basis, we transform
    this problem into a homogeneous, linear system of equations that can be solved
    efficiently. Potential applications of this approach include the identification
    of objectives (both from clean and noisy data) and the construction of surrogate
    models for expensive MOPs.
author:
- first_name: Bennet
  full_name: Gebken, Bennet
  id: '32643'
  last_name: Gebken
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: https://orcid.org/0000-0002-3389-793X
citation:
  ama: 'Gebken B, Peitz S. Inverse multiobjective optimization: Inferring decision
    criteria from data. <i>Journal of Global Optimization</i>. 2021;80:3-29. doi:<a
    href="https://doi.org/10.1007/s10898-020-00983-z">10.1007/s10898-020-00983-z</a>'
  apa: 'Gebken, B., &#38; Peitz, S. (2021). Inverse multiobjective optimization: Inferring
    decision criteria from data. <i>Journal of Global Optimization</i>, <i>80</i>,
    3–29. <a href="https://doi.org/10.1007/s10898-020-00983-z">https://doi.org/10.1007/s10898-020-00983-z</a>'
  bibtex: '@article{Gebken_Peitz_2021, title={Inverse multiobjective optimization:
    Inferring decision criteria from data}, volume={80}, DOI={<a href="https://doi.org/10.1007/s10898-020-00983-z">10.1007/s10898-020-00983-z</a>},
    journal={Journal of Global Optimization}, publisher={Springer}, author={Gebken,
    Bennet and Peitz, Sebastian}, year={2021}, pages={3–29} }'
  chicago: 'Gebken, Bennet, and Sebastian Peitz. “Inverse Multiobjective Optimization:
    Inferring Decision Criteria from Data.” <i>Journal of Global Optimization</i>
    80 (2021): 3–29. <a href="https://doi.org/10.1007/s10898-020-00983-z">https://doi.org/10.1007/s10898-020-00983-z</a>.'
  ieee: 'B. Gebken and S. Peitz, “Inverse multiobjective optimization: Inferring decision
    criteria from data,” <i>Journal of Global Optimization</i>, vol. 80, pp. 3–29,
    2021.'
  mla: 'Gebken, Bennet, and Sebastian Peitz. “Inverse Multiobjective Optimization:
    Inferring Decision Criteria from Data.” <i>Journal of Global Optimization</i>,
    vol. 80, Springer, 2021, pp. 3–29, doi:<a href="https://doi.org/10.1007/s10898-020-00983-z">10.1007/s10898-020-00983-z</a>.'
  short: B. Gebken, S. Peitz, Journal of Global Optimization 80 (2021) 3–29.
date_created: 2020-03-13T12:45:05Z
date_updated: 2022-01-06T06:52:48Z
department:
- _id: '101'
doi: 10.1007/s10898-020-00983-z
intvolume: '        80'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://link.springer.com/content/pdf/10.1007/s10898-020-00983-z.pdf
oa: '1'
page: 3-29
publication: Journal of Global Optimization
publisher: Springer
status: public
title: 'Inverse multiobjective optimization: Inferring decision criteria from data'
type: journal_article
user_id: '47427'
volume: 80
year: '2021'
...
---
_id: '32057'
abstract:
- lang: ger
  text: Ein zentraler Aspekt bei der Untersuchung dynamischer Systeme ist die Analyse
    ihrer invarianten Mengen wie des globalen Attraktors und (in)stabiler Mannigfaltigkeiten.
    Insbesondere wenn das zugrunde liegende System von einem Parameter abhängt, ist
    es entscheidend, sie im Bezug auf diesen Parameter effizient zu verfolgen. Für
    die Berechnung invarianter Mengen stützen wir uns für ihre Approximation auf numerische
    Algorithmen. Typischerweise können diese Methoden jedoch nur auf endlich-dimensionale
    dynamische Systeme angewendet werden. In dieser Arbeit präsentieren wir daher
    einen numerischen Rahmen für die globale dynamische Analyse unendlich-dimensionaler
    Systeme. Wir werden Einbettungstechniken verwenden, um das core dynamical system
    (CDS) zu definieren, welches ein dynamisch äquivalentes endlich-dimensionales
    System ist.Das CDS wird dann verwendet, um eingebettete invariante Mengen, also
    eins-zu-eins Bilder, mittels Mengen-orientierten numerischen Methoden zu approximieren.
    Bei der Konstruktion des CDS ist es entscheidend, eine geeignete Beobachtungsabbildung
    auszuwählen und die geeignete inverse Abbildung zu entwerfen. Dazu werden wir
    geeignete numerische Implementierungen des CDS für DDEs und PDEs vorstellen. Für
    eine nachfolgende geometrische Analyse der eingebetteten invarianten Menge betrachten
    wir eine Lerntechnik namens diffusion maps, die ihre intrinsische Geometrie enthüllt
    sowie ihre Dimension schätzt. Schließlich wenden wir unsere entwickelten numerischen
    Methoden an einigen bekannten unendlich-dimensionale dynamischen Systeme an, wie
    die Mackey-Glass-Gleichung, die Kuramoto-Sivashinsky-Gleichung und die Navier-Stokes-Gleichung.
- lang: eng
  text: One central aspect in the study of dynamical systems is the analysis of its
    invariant sets such as the global attractor and (un)stable manifolds. In particular,
    when the underlying system depends on a parameter it is crucial to efficiently
    track those set with respect to this parameter. For the computation of invariant
    sets we rely on numerical algorithms for their approximation but typically those
    tools can only be applied to finite-dimensional dynamical systems. Thus, in thesis
    we present a numerical framework for the global dynamical analysis of infinite-dimensional
    systems. We will use embedding techniques for the definition of the core dynamical
    system (CDS) which is a dynamically equivalent finite-dimensional system. The
    CDS is then used for the approximation of related embedded invariant sets, i.e,
    one-to-one images, by set-oriented numerical methods. For the construction of
    the CDS it is crucial to choose an appropriate observation map and to design its
    corresponding inverse. Therefore, we will present suitable numerical realizations
    of the CDS for DDEs and PDEs. For a subsequent geometric analysis of the embedded
    invariant set we will consider a manifold learning technique called diffusion
    maps which reveals its intrinsic geometry and estimates its dimension. Finally,
    we apply our develop numerical tools on some well-known infinite-dimensional dynamical
    systems such as the Mackey-Glass equation, the Kuramoto-Sivashinsky equation and
    the Navier-Stokes equation.
author:
- first_name: Raphael
  full_name: Gerlach, Raphael
  id: '32655'
  last_name: Gerlach
citation:
  ama: Gerlach R. <i>The Computation and Analysis of Invariant Sets of Infinite-Dimensional
    Systems</i>.; 2021. doi:<a href="https://doi.org/10.17619/UNIPB/1-1278">10.17619/UNIPB/1-1278</a>
  apa: Gerlach, R. (2021). <i>The Computation and Analysis of Invariant Sets of Infinite-Dimensional
    Systems</i>. <a href="https://doi.org/10.17619/UNIPB/1-1278">https://doi.org/10.17619/UNIPB/1-1278</a>
  bibtex: '@book{Gerlach_2021, title={The Computation and Analysis of Invariant Sets
    of Infinite-Dimensional Systems}, DOI={<a href="https://doi.org/10.17619/UNIPB/1-1278">10.17619/UNIPB/1-1278</a>},
    author={Gerlach, Raphael}, year={2021} }'
  chicago: Gerlach, Raphael. <i>The Computation and Analysis of Invariant Sets of
    Infinite-Dimensional Systems</i>, 2021. <a href="https://doi.org/10.17619/UNIPB/1-1278">https://doi.org/10.17619/UNIPB/1-1278</a>.
  ieee: R. Gerlach, <i>The Computation and Analysis of Invariant Sets of Infinite-Dimensional
    Systems</i>. 2021.
  mla: Gerlach, Raphael. <i>The Computation and Analysis of Invariant Sets of Infinite-Dimensional
    Systems</i>. 2021, doi:<a href="https://doi.org/10.17619/UNIPB/1-1278">10.17619/UNIPB/1-1278</a>.
  short: R. Gerlach, The Computation and Analysis of Invariant Sets of Infinite-Dimensional
    Systems, 2021.
date_created: 2022-06-20T09:54:24Z
date_updated: 2022-06-20T13:40:30Z
department:
- _id: '101'
doi: 10.17619/UNIPB/1-1278
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://digital.ub.uni-paderborn.de/hs/download/pdf/6214949
oa: '1'
status: public
supervisor:
- first_name: Michael
  full_name: Dellnitz , Michael
  last_name: 'Dellnitz '
- first_name: Péter
  full_name: Koltai, Péter
  last_name: Koltai
title: The Computation and Analysis of Invariant Sets of Infinite-Dimensional Systems
type: dissertation
user_id: '32643'
year: '2021'
...
---
_id: '16294'
abstract:
- lang: eng
  text: "Model predictive control is a prominent approach to construct a feedback\r\ncontrol
    loop for dynamical systems. Due to real-time constraints, the major\r\nchallenge
    in MPC is to solve model-based optimal control problems in a very\r\nshort amount
    of time. For linear-quadratic problems, Bemporad et al. have\r\nproposed an explicit
    formulation where the underlying optimization problems are\r\nsolved a priori
    in an offline phase. In this article, we present an extension\r\nof this concept
    in two significant ways. We consider nonlinear problems and -\r\nmore importantly
    - problems with multiple conflicting objective functions. In\r\nthe offline phase,
    we build a library of Pareto optimal solutions from which we\r\nthen obtain a
    valid compromise solution in the online phase according to a\r\ndecision maker's
    preference. Since the standard multi-parametric programming\r\napproach is no
    longer valid in this situation, we instead use interpolation\r\nbetween different
    entries of the library. To reduce the number of problems that\r\nhave to be solved
    in the offline phase, we exploit symmetries in the dynamical\r\nsystem and the
    corresponding multiobjective optimal control problem. The\r\nresults are verified
    using two different examples from autonomous driving."
author:
- first_name: Sina
  full_name: Ober-Blöbaum, Sina
  id: '16494'
  last_name: Ober-Blöbaum
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: https://orcid.org/0000-0002-3389-793X
citation:
  ama: Ober-Blöbaum S, Peitz S. Explicit multiobjective model predictive control for
    nonlinear systems  with symmetries. <i>International Journal of Robust and Nonlinear
    Control</i>. 2021;31(2):380-403. doi:<a href="https://doi.org/10.1002/rnc.5281">10.1002/rnc.5281</a>
  apa: Ober-Blöbaum, S., &#38; Peitz, S. (2021). Explicit multiobjective model predictive
    control for nonlinear systems  with symmetries. <i>International Journal of Robust
    and Nonlinear Control</i>, <i>31(2)</i>, 380–403. <a href="https://doi.org/10.1002/rnc.5281">https://doi.org/10.1002/rnc.5281</a>
  bibtex: '@article{Ober-Blöbaum_Peitz_2021, title={Explicit multiobjective model
    predictive control for nonlinear systems  with symmetries}, volume={31(2)}, DOI={<a
    href="https://doi.org/10.1002/rnc.5281">10.1002/rnc.5281</a>}, journal={International
    Journal of Robust and Nonlinear Control}, author={Ober-Blöbaum, Sina and Peitz,
    Sebastian}, year={2021}, pages={380–403} }'
  chicago: 'Ober-Blöbaum, Sina, and Sebastian Peitz. “Explicit Multiobjective Model
    Predictive Control for Nonlinear Systems  with Symmetries.” <i>International Journal
    of Robust and Nonlinear Control</i> 31(2) (2021): 380–403. <a href="https://doi.org/10.1002/rnc.5281">https://doi.org/10.1002/rnc.5281</a>.'
  ieee: 'S. Ober-Blöbaum and S. Peitz, “Explicit multiobjective model predictive control
    for nonlinear systems  with symmetries,” <i>International Journal of Robust and
    Nonlinear Control</i>, vol. 31(2), pp. 380–403, 2021, doi: <a href="https://doi.org/10.1002/rnc.5281">10.1002/rnc.5281</a>.'
  mla: Ober-Blöbaum, Sina, and Sebastian Peitz. “Explicit Multiobjective Model Predictive
    Control for Nonlinear Systems  with Symmetries.” <i>International Journal of Robust
    and Nonlinear Control</i>, vol. 31(2), 2021, pp. 380–403, doi:<a href="https://doi.org/10.1002/rnc.5281">10.1002/rnc.5281</a>.
  short: S. Ober-Blöbaum, S. Peitz, International Journal of Robust and Nonlinear
    Control 31(2) (2021) 380–403.
date_created: 2020-03-13T12:44:36Z
date_updated: 2022-01-24T13:27:50Z
department:
- _id: '101'
doi: 10.1002/rnc.5281
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://onlinelibrary.wiley.com/doi/epdf/10.1002/rnc.5281
oa: '1'
page: 380-403
project:
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
publication: International Journal of Robust and Nonlinear Control
status: public
title: Explicit multiobjective model predictive control for nonlinear systems  with
  symmetries
type: journal_article
user_id: '15694'
volume: 31(2)
year: '2021'
...
---
_id: '17411'
abstract:
- lang: eng
  text: Many dynamical systems possess symmetries, e.g. rotational and translational
    invariances of mechanical systems. These can be beneficially exploited in the
    design of numerical optimal control methods. We present a model predictive control
    scheme which is based on a library of precomputed motion primitives. The primitives
    are equivalence classes w.r.t. the symmetry of the optimal control problems. Trim
    primitives as relative equilibria w.r.t. this symmetry, play a crucial role in
    the algorithm. The approach is illustrated using an academic mobile robot example.
author:
- first_name: Kathrin
  full_name: Flaßkamp, Kathrin
  last_name: Flaßkamp
- first_name: Sina
  full_name: Ober-Blöbaum, Sina
  last_name: Ober-Blöbaum
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: 0000-0002-3389-793X
citation:
  ama: 'Flaßkamp K, Ober-Blöbaum S, Peitz S. Symmetry in Optimal Control: A Multiobjective
    Model Predictive Control Approach. In: Junge O, Schütze O, Froyland G, Ober-Blöbaum
    S, Padberg-Gehle K, eds. <i>Advances in Dynamics, Optimization and Computation</i>.
    Cham: Springer; 2020. doi:<a href="https://doi.org/10.1007/978-3-030-51264-4_9">10.1007/978-3-030-51264-4_9</a>'
  apa: 'Flaßkamp, K., Ober-Blöbaum, S., &#38; Peitz, S. (2020). Symmetry in Optimal
    Control: A Multiobjective Model Predictive Control Approach. In O. Junge, O. Schütze,
    G. Froyland, S. Ober-Blöbaum, &#38; K. Padberg-Gehle (Eds.), <i>Advances in Dynamics,
    Optimization and Computation</i>. Cham: Springer. <a href="https://doi.org/10.1007/978-3-030-51264-4_9">https://doi.org/10.1007/978-3-030-51264-4_9</a>'
  bibtex: '@inbook{Flaßkamp_Ober-Blöbaum_Peitz_2020, place={Cham}, title={Symmetry
    in Optimal Control: A Multiobjective Model Predictive Control Approach}, DOI={<a
    href="https://doi.org/10.1007/978-3-030-51264-4_9">10.1007/978-3-030-51264-4_9</a>},
    booktitle={Advances in Dynamics, Optimization and Computation}, publisher={Springer},
    author={Flaßkamp, Kathrin and Ober-Blöbaum, Sina and Peitz, Sebastian}, editor={Junge,
    Oliver and Schütze, Oliver and Froyland, Gary and Ober-Blöbaum, Sina and Padberg-Gehle,
    KathrinEditors}, year={2020} }'
  chicago: 'Flaßkamp, Kathrin, Sina Ober-Blöbaum, and Sebastian Peitz. “Symmetry in
    Optimal Control: A Multiobjective Model Predictive Control Approach.” In <i>Advances
    in Dynamics, Optimization and Computation</i>, edited by Oliver Junge, Oliver
    Schütze, Gary Froyland, Sina Ober-Blöbaum, and Kathrin Padberg-Gehle. Cham: Springer,
    2020. <a href="https://doi.org/10.1007/978-3-030-51264-4_9">https://doi.org/10.1007/978-3-030-51264-4_9</a>.'
  ieee: 'K. Flaßkamp, S. Ober-Blöbaum, and S. Peitz, “Symmetry in Optimal Control:
    A Multiobjective Model Predictive Control Approach,” in <i>Advances in Dynamics,
    Optimization and Computation</i>, O. Junge, O. Schütze, G. Froyland, S. Ober-Blöbaum,
    and K. Padberg-Gehle, Eds. Cham: Springer, 2020.'
  mla: 'Flaßkamp, Kathrin, et al. “Symmetry in Optimal Control: A Multiobjective Model
    Predictive Control Approach.” <i>Advances in Dynamics, Optimization and Computation</i>,
    edited by Oliver Junge et al., Springer, 2020, doi:<a href="https://doi.org/10.1007/978-3-030-51264-4_9">10.1007/978-3-030-51264-4_9</a>.'
  short: 'K. Flaßkamp, S. Ober-Blöbaum, S. Peitz, in: O. Junge, O. Schütze, G. Froyland,
    S. Ober-Blöbaum, K. Padberg-Gehle (Eds.), Advances in Dynamics, Optimization and
    Computation, Springer, Cham, 2020.'
date_created: 2020-07-27T09:50:19Z
date_updated: 2022-01-06T06:53:11Z
department:
- _id: '101'
doi: 10.1007/978-3-030-51264-4_9
editor:
- first_name: Oliver
  full_name: Junge, Oliver
  last_name: Junge
- first_name: Oliver
  full_name: Schütze, Oliver
  last_name: Schütze
- first_name: Gary
  full_name: Froyland, Gary
  last_name: Froyland
- first_name: Sina
  full_name: Ober-Blöbaum, Sina
  last_name: Ober-Blöbaum
- first_name: Kathrin
  full_name: Padberg-Gehle, Kathrin
  last_name: Padberg-Gehle
language:
- iso: eng
place: Cham
publication: Advances in Dynamics, Optimization and Computation
publication_identifier:
  isbn:
  - '9783030512637'
  - '9783030512644'
  issn:
  - 2198-4182
  - 2198-4190
publication_status: published
publisher: Springer
status: public
title: 'Symmetry in Optimal Control: A Multiobjective Model Predictive Control Approach'
type: book_chapter
user_id: '47427'
year: '2020'
...
---
_id: '21819'
abstract:
- lang: eng
  text: <jats:p>Many dimensionality and model reduction techniques rely on estimating
    dominant eigenfunctions of associated dynamical operators from data. Important
    examples include the Koopman operator and its generator, but also the Schrödinger
    operator. We propose a kernel-based method for the approximation of differential
    operators in reproducing kernel Hilbert spaces and show how eigenfunctions can
    be estimated by solving auxiliary matrix eigenvalue problems. The resulting algorithms
    are applied to molecular dynamics and quantum chemistry examples. Furthermore,
    we exploit that, under certain conditions, the Schrödinger operator can be transformed
    into a Kolmogorov backward operator corresponding to a drift-diffusion process
    and vice versa. This allows us to apply methods developed for the analysis of
    high-dimensional stochastic differential equations to quantum mechanical systems.</jats:p>
article_number: '722'
author:
- first_name: Stefan
  full_name: Klus, Stefan
  last_name: Klus
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Boumediene
  full_name: Hamzi, Boumediene
  last_name: Hamzi
citation:
  ama: Klus S, Nüske F, Hamzi B. Kernel-Based Approximation of the Koopman Generator
    and Schrödinger Operator. <i>Entropy</i>. 2020. doi:<a href="https://doi.org/10.3390/e22070722">10.3390/e22070722</a>
  apa: Klus, S., Nüske, F., &#38; Hamzi, B. (2020). Kernel-Based Approximation of
    the Koopman Generator and Schrödinger Operator. <i>Entropy</i>. <a href="https://doi.org/10.3390/e22070722">https://doi.org/10.3390/e22070722</a>
  bibtex: '@article{Klus_Nüske_Hamzi_2020, title={Kernel-Based Approximation of the
    Koopman Generator and Schrödinger Operator}, DOI={<a href="https://doi.org/10.3390/e22070722">10.3390/e22070722</a>},
    number={722}, journal={Entropy}, author={Klus, Stefan and Nüske, Feliks and Hamzi,
    Boumediene}, year={2020} }'
  chicago: Klus, Stefan, Feliks Nüske, and Boumediene Hamzi. “Kernel-Based Approximation
    of the Koopman Generator and Schrödinger Operator.” <i>Entropy</i>, 2020. <a href="https://doi.org/10.3390/e22070722">https://doi.org/10.3390/e22070722</a>.
  ieee: S. Klus, F. Nüske, and B. Hamzi, “Kernel-Based Approximation of the Koopman
    Generator and Schrödinger Operator,” <i>Entropy</i>, 2020.
  mla: Klus, Stefan, et al. “Kernel-Based Approximation of the Koopman Generator and
    Schrödinger Operator.” <i>Entropy</i>, 722, 2020, doi:<a href="https://doi.org/10.3390/e22070722">10.3390/e22070722</a>.
  short: S. Klus, F. Nüske, B. Hamzi, Entropy (2020).
date_created: 2021-04-28T18:06:35Z
date_updated: 2022-01-06T06:55:16Z
department:
- _id: '101'
doi: 10.3390/e22070722
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.mdpi.com/1099-4300/22/7/722
oa: '1'
publication: Entropy
publication_identifier:
  issn:
  - 1099-4300
publication_status: published
status: public
title: Kernel-Based Approximation of the Koopman Generator and Schrödinger Operator
type: journal_article
user_id: '81513'
year: '2020'
...
---
_id: '10596'
abstract:
- lang: eng
  text: Multi-objective optimization is an active field of research that has many
    applications. Owing to its success and because decision-making processes are becoming
    more and more complex, there is a recent trend for incorporating many objectives
    into such problems. The challenge with such problems, however, is that the dimensions
    of the solution sets—the so-called Pareto sets and fronts—grow with the number
    of objectives. It is thus no longer possible to compute or to approximate the
    entire solution set of a given problem that contains many (e.g. more than three)
    objectives. On the other hand, the computation of single solutions (e.g. via scalarization
    methods) leads to unsatisfying results in many cases, even if user preferences
    are incorporated. In this article, the Pareto Explorer tool is presented—a global/local
    exploration tool for the treatment of many-objective optimization problems (MaOPs).
    In the first step, a solution of the problem is computed via a global search algorithm
    that ideally already includes user preferences. In the second step, a local search
    along the Pareto set/front of the given MaOP is performed in user specified directions.
    For this, several continuation-like procedures are proposed that can incorporate
    preferences defined in decision, objective, or in weight space. The applicability
    and usefulness of Pareto Explorer is demonstrated on benchmark problems as well
    as on an application from industrial laundry design.
article_type: original
author:
- first_name: Oliver
  full_name: Schütze, Oliver
  last_name: Schütze
- first_name: Oliver
  full_name: Cuate, Oliver
  last_name: Cuate
- first_name: Adanay
  full_name: Martín, Adanay
  last_name: Martín
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: https://orcid.org/0000-0002-3389-793X
- first_name: Michael
  full_name: Dellnitz, Michael
  last_name: Dellnitz
citation:
  ama: 'Schütze O, Cuate O, Martín A, Peitz S, Dellnitz M. Pareto Explorer: a global/local
    exploration tool for many-objective optimization problems. <i>Engineering Optimization</i>.
    2020;52(5):832-855. doi:<a href="https://doi.org/10.1080/0305215x.2019.1617286">10.1080/0305215x.2019.1617286</a>'
  apa: 'Schütze, O., Cuate, O., Martín, A., Peitz, S., &#38; Dellnitz, M. (2020).
    Pareto Explorer: a global/local exploration tool for many-objective optimization
    problems. <i>Engineering Optimization</i>, <i>52</i>(5), 832–855. <a href="https://doi.org/10.1080/0305215x.2019.1617286">https://doi.org/10.1080/0305215x.2019.1617286</a>'
  bibtex: '@article{Schütze_Cuate_Martín_Peitz_Dellnitz_2020, title={Pareto Explorer:
    a global/local exploration tool for many-objective optimization problems}, volume={52},
    DOI={<a href="https://doi.org/10.1080/0305215x.2019.1617286">10.1080/0305215x.2019.1617286</a>},
    number={5}, journal={Engineering Optimization}, author={Schütze, Oliver and Cuate,
    Oliver and Martín, Adanay and Peitz, Sebastian and Dellnitz, Michael}, year={2020},
    pages={832–855} }'
  chicago: 'Schütze, Oliver, Oliver Cuate, Adanay Martín, Sebastian Peitz, and Michael
    Dellnitz. “Pareto Explorer: A Global/Local Exploration Tool for Many-Objective
    Optimization Problems.” <i>Engineering Optimization</i> 52, no. 5 (2020): 832–55.
    <a href="https://doi.org/10.1080/0305215x.2019.1617286">https://doi.org/10.1080/0305215x.2019.1617286</a>.'
  ieee: 'O. Schütze, O. Cuate, A. Martín, S. Peitz, and M. Dellnitz, “Pareto Explorer:
    a global/local exploration tool for many-objective optimization problems,” <i>Engineering
    Optimization</i>, vol. 52, no. 5, pp. 832–855, 2020.'
  mla: 'Schütze, Oliver, et al. “Pareto Explorer: A Global/Local Exploration Tool
    for Many-Objective Optimization Problems.” <i>Engineering Optimization</i>, vol.
    52, no. 5, 2020, pp. 832–55, doi:<a href="https://doi.org/10.1080/0305215x.2019.1617286">10.1080/0305215x.2019.1617286</a>.'
  short: O. Schütze, O. Cuate, A. Martín, S. Peitz, M. Dellnitz, Engineering Optimization
    52 (2020) 832–855.
date_created: 2019-07-10T08:14:39Z
date_updated: 2022-01-06T06:50:46Z
department:
- _id: '101'
doi: 10.1080/0305215x.2019.1617286
intvolume: '        52'
issue: '5'
language:
- iso: eng
page: 832-855
publication: Engineering Optimization
publication_identifier:
  issn:
  - 0305-215X
  - 1029-0273
publication_status: published
status: public
title: 'Pareto Explorer: a global/local exploration tool for many-objective optimization
  problems'
type: journal_article
user_id: '47427'
volume: 52
year: '2020'
...
---
_id: '16288'
abstract:
- lang: eng
  text: We derive a data-driven method for the approximation of the Koopman generator
    called gEDMD, which can be regarded as a straightforward extension of EDMD (extended
    dynamic mode decomposition). This approach is applicable to deterministic and
    stochastic dynamical systems. It can be used for computing eigenvalues, eigenfunctions,
    and modes of the generator and for system identification. In addition to learning
    the governing equations of deterministic systems, which then reduces to SINDy
    (sparse identification of nonlinear dynamics), it is possible to identify the
    drift and diffusion terms of stochastic differential equations from data. Moreover,
    we apply gEDMD to derive coarse-grained models of high-dimensional systems, and
    also to determine efficient model predictive control strategies. We highlight
    relationships with other methods and demonstrate the efficacy of the proposed
    methods using several guiding examples and prototypical molecular dynamics problems.
article_number: '132416'
author:
- first_name: Stefan
  full_name: Klus, Stefan
  last_name: Klus
- first_name: Feliks
  full_name: Nüske, Feliks
  id: '81513'
  last_name: Nüske
  orcid: 0000-0003-2444-7889
- first_name: Sebastian
  full_name: Peitz, Sebastian
  id: '47427'
  last_name: Peitz
  orcid: https://orcid.org/0000-0002-3389-793X
- first_name: Jan-Hendrik
  full_name: Niemann, Jan-Hendrik
  last_name: Niemann
- first_name: Cecilia
  full_name: Clementi, Cecilia
  last_name: Clementi
- first_name: Christof
  full_name: Schütte, Christof
  last_name: Schütte
citation:
  ama: 'Klus S, Nüske F, Peitz S, Niemann J-H, Clementi C, Schütte C. Data-driven
    approximation of the Koopman generator: Model reduction, system identification,
    and control. <i>Physica D: Nonlinear Phenomena</i>. 2020;406. doi:<a href="https://doi.org/10.1016/j.physd.2020.132416">10.1016/j.physd.2020.132416</a>'
  apa: 'Klus, S., Nüske, F., Peitz, S., Niemann, J.-H., Clementi, C., &#38; Schütte,
    C. (2020). Data-driven approximation of the Koopman generator: Model reduction,
    system identification, and control. <i>Physica D: Nonlinear Phenomena</i>, <i>406</i>.
    <a href="https://doi.org/10.1016/j.physd.2020.132416">https://doi.org/10.1016/j.physd.2020.132416</a>'
  bibtex: '@article{Klus_Nüske_Peitz_Niemann_Clementi_Schütte_2020, title={Data-driven
    approximation of the Koopman generator: Model reduction, system identification,
    and control}, volume={406}, DOI={<a href="https://doi.org/10.1016/j.physd.2020.132416">10.1016/j.physd.2020.132416</a>},
    number={132416}, journal={Physica D: Nonlinear Phenomena}, author={Klus, Stefan
    and Nüske, Feliks and Peitz, Sebastian and Niemann, Jan-Hendrik and Clementi,
    Cecilia and Schütte, Christof}, year={2020} }'
  chicago: 'Klus, Stefan, Feliks Nüske, Sebastian Peitz, Jan-Hendrik Niemann, Cecilia
    Clementi, and Christof Schütte. “Data-Driven Approximation of the Koopman Generator:
    Model Reduction, System Identification, and Control.” <i>Physica D: Nonlinear
    Phenomena</i> 406 (2020). <a href="https://doi.org/10.1016/j.physd.2020.132416">https://doi.org/10.1016/j.physd.2020.132416</a>.'
  ieee: 'S. Klus, F. Nüske, S. Peitz, J.-H. Niemann, C. Clementi, and C. Schütte,
    “Data-driven approximation of the Koopman generator: Model reduction, system identification,
    and control,” <i>Physica D: Nonlinear Phenomena</i>, vol. 406, 2020.'
  mla: 'Klus, Stefan, et al. “Data-Driven Approximation of the Koopman Generator:
    Model Reduction, System Identification, and Control.” <i>Physica D: Nonlinear
    Phenomena</i>, vol. 406, 132416, 2020, doi:<a href="https://doi.org/10.1016/j.physd.2020.132416">10.1016/j.physd.2020.132416</a>.'
  short: 'S. Klus, F. Nüske, S. Peitz, J.-H. Niemann, C. Clementi, C. Schütte, Physica
    D: Nonlinear Phenomena 406 (2020).'
date_created: 2020-03-13T12:35:40Z
date_updated: 2022-01-06T06:52:48Z
department:
- _id: '101'
doi: 10.1016/j.physd.2020.132416
intvolume: '       406'
language:
- iso: eng
publication: 'Physica D: Nonlinear Phenomena'
publication_identifier:
  issn:
  - 0167-2789
publication_status: published
status: public
title: 'Data-driven approximation of the Koopman generator: Model reduction, system
  identification, and control'
type: journal_article
user_id: '47427'
volume: 406
year: '2020'
...
