Presentations

Conferences | Colloquia and seminars

Conferences

• Convex relaxation of hybrid discrete-valued optimization problems,
  4th Austrian Calculus of Variations Day, Innsbruck, Austria, November 7–8, 2024.
• Optimal control of the principal coefficient in a scalar wave equation,
  31st IFIP TC7 Conference on System Modeling and Optimization, Hamburg, Germany, August 12–16, 2024.
• Primal-dual proximal splitting and generalized conjugation in nonsmooth nonconvex optimization,
  Recent Advances in Scientific Computing and Inverse Problems, Hong Kong, China, March 11–12, 2024.
• MRI Pulse Design via discrete-valued optimal control,
  Applied Inverse Problems Conference, Göttingen, Germany, September 4–8, 2023.
• Primal-dual proximal splitting and generalized conjugation in non-smooth non-convex optimization,
  International Congress on Industrial and Applied Mathematics, Tokyo, Japan, August 20–25, 2023.
• Nonsmooth regularization of a coefficient inverse problem for the wave equation,
  Inverse Problems: Modeling and Simulation, Mellieha, Malta, May 23–27, 2022.
• Optimal control of non-smooth partial differential equations,
  29th IFIP TC7 Conference on System Modelling and Optimization, Quito, Ecuador (online), August 30–September 3, 2021.
• Nonsmooth regularization of a coefficient inverse problem for the wave equation,
  13th International Scientific Conference and Young Scientist School “Theory and Computational Methods for Inverse and Ill-posed Problems”`, Novosibirsk, Akademgorodok (online), April 12–20, 2021.
• Iterative regularization of nonsmooth ill-posed problems,
  12th International Scientific Conference and Young Scientist School “Theory and Computational Methods for Inverse and Ill-posed Problems”`, Novosibirsk, Akademgorodok (online), October 4–10, 2020.
• Convex regularization of hybrid discrete-continuous control problems,
  SIGOPT 2020 International Conference on Optimization, TU Dortmund, March 4–6, 2020.
• Multibang regularization of a coefficient inverse problem for the wave equation,
  Workshop Computational Methods for New Directions in Inverse Problems, Texas A&M University, College Station, TX, USA, February 3–5, 2020.
• Convex regularization of hybrid discrete-continuous control problems,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, Indian Institute of Science, Bangalore, India, December 2–4, 2019.
• Iterative regularization for nonsmooth inverse problems,
  1st Alps-Adriatic Inverse Problems Workshop, Klagenfurt, Austria, November 7–8, 2019.
• Optimal control of non-smooth partial differential equations,
  Workshop “New Trends in PDE-constrained Optimization, RICAM, Linz, Austria, October 14–18, 2019.
• Optimal control of the principal coefficient in a scalar wave equation,
  19th French-German-Swiss Conference on Optimization, Nice, France, September 17–20, 2019.
• Discrete material optimization for the wave equation,
  International Conference on Continuous Optimization, Berlin, Germany, August 5–8, 2019.
• Iterative regularization for nonsmooth inverse problems,
  International Congress on Industrial and Applied Mathematics, Valencia, Spain, July 15–19, 2019.
• Iterative regularization of non-smooth equations,
  Applied Inverse Problems Conference, Grenoble, France, July 8–12, 2019.
• Multibang regularization of a coefficient inverse problem for the wave equation,
  Applied Inverse Problems Conference, Grenoble, France, July 8–12, 2019.
• Accelerated primal-dual methods for structured non-convex optimization,
  International Conference on Stochastic Optimization and Related Topics Mülheim an der Ruhr, Germany, April 25–26, 2019.
• Multibang regularization of a coefficient inverse problem for the wave equation,
  Workshop Mathematical and Numerical Approaches for Multi-Wave Inverse Problems, CIRM, Marseille, France, April 1–5, 2019.
• Iterative regularization of non-smooth equations,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, Garching, Germany, March 11–13, 2019.
• Accelerated primal-dual methods for PDE-constrained optimization,
  International Workshop on PDE-constrained Optimization, Optimal Control, and Applications, Tsinghua Sanya International Mathematics Forum, Hainan, China, December 10–14, 2018.
• Bouligand–Landweber iteration for a non-smooth ill-posed problem,
  COPDESC Workshop “Analysis, Control and Inverse Problems for PDEs”, Napoli, Italy, November 26–30, 2018.
• Convex regularization of discrete-valued inverse problems,
  2018 Joint Meeting of KMS and DMV, Seoul, South Korea, October 3–6, 2018.
• Bouligand–Landweber iteration for a non-smooth ill-posed problem,
  VI Latin American Workshop on Optimization and Control, Quito, Ecuador, September 3–7, 2018.
• Bouligand–Landweber iteration for a non-smooth ill-posed problem,
  28th IFIP TC7 Conference on System Modelling and Optimization, Essen, Germany, July 23–27, 2018.
• Convex regularization of discrete-valued inverse problems,
  Inverse Problems: Modeling and Simulation, Mellieha, Malta, May 21–25, 2018.
• Total variation regularization of multi-material topology optimization,
  7th International Conference on High Performance Scientific Computing, Hanoi, Vietnam, March 19–23, 2018.
• Design of optimal RF pulses for NMR as a discrete-valued control problem,
  9th Vienna International Conference on Mathematical Modelling, Wien, Austria, February 21–23, 2018.
• Convex regularization of discrete-valued inverse problems,
  New Trends in Parameter Identification for Mathematical Models, IMPA, Rio de Janeiro, Brazil, October 30–November 3, 2017.
• Total variation regularization of multi-material topology optimization,
  IFIP WG 7.2 Workshop “Optimal Control of PDES”, Castro Urdiales, Spain, September 18–21, 2017.
• Convex relaxation of hybrid discrete-continuous control problems,
  19th ÖMG Congress and DMV Annual Meeting, Salzburg, Austria, September 11–15, 2017.
• Convex regularization of discrete-valued inverse problems,
  Workshop “Variational methods, new optimisation techniques and new fast numerical algorithms, Isaac Newton Institute, Cambridge, UK, September 4–8, 2017.
• Discrete regularization of parameter identification problems,
  Workshop “Computational Imaging and Tomography, Innsbruck, Austria, August 17–18, 2017.
• Discrete regularization of parameter identification problems,
  Applied Inverse Problems, Hangzhou, China, May 29–June 2, 2017.
• Adaptive discretization and first-order methods for nonsmooth inverse problems for PDEs,
  LMS/Turing Workshop Inverse Problems and Data Science, Edinburgh, UK, May 8–11, 2017.
• Convex regularization of hybrid discrete-continuous control problems,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, Garching, Germany, April 5–7, 2017.
• A primal–dual extragradient method for nonlinear inverse problems for PDEs,
  Optimization Techniques for Inverse Problems III, Modena, Italy, September 19–21, 2016.
• A nonlinear primal–dual extragradient method for nonsmooth PDE-constrained optimization,
  IFIP Workshop “Optimal Control Meets Inverse Problems”, Essen, Germany, September 5–9, 2016.
• A nonlinear primal–dual extragradient method for nonsmooth PDE-constrained optimization,
  5th International Conference on Continuous Optimization, Tokyo, Japan, August 8–11, 2016.
• Nonsmooth optimization of partial differential equations,
  XII International Conference on Approximation and Optimization in the Carribean, La Habana, Cuba, June 6–10, 2016.
• A primal-dual extragradient method for nonlinear forward models in function spaces,
  SIAM Conference on Imaging Science, Albuquerque, New Mexico, May 23–26, 2016.
• Second-order analysis of pointwise subdifferentials and applications to nonsmooth optimization,
  Workshop on Nonsmooth and Stochastic Optimization with Applications to Energy Management, WIAS, Berlin, May 10–12, 2016.
• Stochastic inverse problems with impulsive noise,
  SIAM Conference on Uncertainty Quantification, Lausanne, Switzerland, April 5–8, 2016.
• Convex regularization of hybrid discrete-continuous inverse problems,
  International Workshop on Recent Developments in Inverse Problems, WIAS, Berlin, September 17–18, 2015.
• Convex regularization of hybrid discrete-continuous inverse problems,
  8th International Congress on Industrial and Applied Mathematics, Beijing, China, August 10–14, 2015.
• A primal-dual extragradient method for nonsmooth nonlinear inverse problems for PDEs,
  International Conference on Inverse Problems, Imaging, and Applications, Hangzhou, China, August 6–8, 2015.
• A primal-dual extragradient method for nonlinear operators in function spaces,
  27th IFIP TC7 Conference, Sophia Antipolis, France, June 29–July 3, 2015.
• A convex analysis approach to multi-material topology optimization,
  International Workshop “From Open to Closed Loop Control, Mariatrost, Austria, June 22–26, 2015.
• Stochastic inverse problems with impulsive noise,
  Applied Inverse Problems, Helsinki, Finland, May 25–29, 2015.
• A convex analysis approach to switching control of PDEs,
  International Conference on Inverse Problems and Optimal Control, Hong Kong, China, December 4–6, 2014.
• Stochastic inverse problems with impulsive noise,
  Chemnitz Symposium on Inverse Problems, Chemnitz, Germany, September 18–19, 2014.
• Convex relaxation of hybrid binary–continuous problems,
  Inverse Problems – from Theory to Application, Bristol, UK, August 26–28, 2014.
• Avoiding degeneracy in the Westervelt equation by state constrained optimal control,
  10th AIMS Conference on Dynamical Systems, Differential Equations and Applications, Madrid, Spain, July 7–11, 2014.
• A convex analysis approach to hybrid binary–continuous optimal control problems with application to switching control,
  10th AIMS Conference on Dynamical Systems, Differential Equations and Applications, Madrid, Spain, July 7–11, 2014.
• Multibang control of elliptic equations,
  SIAM Conference on Optimization, San Diego, California, USA, May 19–22, 2014.
• Multibang control of elliptic equations,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, München, Germany, March 3–5, 2014.
• Sparse controls for elliptic and parabolic partial differential equations,
  1st IFAC Workshop on Control of Systems Modeled by PDEs, Paris, France, September 25–27, 2013.
• Parameter identification problems with uniform noise,
  26th IFIP TC7 Conference, Klagenfurt, Austria, September 9–13, 2013.
• Multi-bang control of elliptic systems,
  4th International Conference on Continuous Optimization, Lisboa, Portugal, July 29–August 1, 2013.
• Parameter identification problems with uniform noise,
  3rd European Conference on Computational Optimization, Chemnitz, Germany, July 17–19, 2013.
• Coefficient inverse problems with uniform noise,
  Applied Inverse Problems, Daejeon, South Korea, July 1–5, 2013.
• Optimal control of elliptic PDEs with positive measures,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, München, Germany, March 11–13, 2013.
• Parameter identification with non-Gaussian noise,
  Oberwolfach Workshop Computational Inverse Problems, Mathematisches Forschungsinstitut Oberwolfach, Germany, October 22–26, 2012.
• Inverse problems for PDEs with uniform noise,
  21st International Symposium on Mathematical Programming, Berlin, Germany, August 20–24, 2012.
• Inverse problems for PDEs with L^∞ data fitting,
  Inverse Problems: Modeling and Simulation, Antalya, Turkey, May 21–25, 2012.
• Inverse Problems with uniform noise,
  Workshop Numerical Methods for Optimal Control and Inverse Problems, München, Germany, March 12–14, 2012.
• A measure space approach to optimal source placement,
  ESF Workshop Optimization with PDE constraints, Prague, Czech Republic, December 9–10, 2011.
• Variational methods for image reconstruction in magnetic resonance imaging,
  Dagstuhl Seminar Efficient Algorithms for Global Optimisation Methods in Computer Vision, Schloß Dagstuhl, Germany, November 20–25, 2011.
• Minimum effort optimal control of elliptic PDEs,
  25th IFIP TC7 Conference, Berlin, Germany, September 12–16, 2011.
• A measure space approach to optimal source placement,
  25th IFIP TC7 Conference, Berlin, Germany, September 12–16, 2011.
• Autocalibrated parameter choice for non-smooth noise models,
  Applied Inverse Problems, College Station, Texas, USA, May 23–27, 2011.
• L¹ data fitting for parameter identification problems for PDEs,
  Applied Inverse Problems, College Station, Texas, USA, May 23–27, 2011.
• Parameter identification problems for PDEs with L¹ data fitting,
  SIAM Conference on Optimization, Darmstadt, Germany, May 16–19, 2011.
• Optimal source placement as an optimal control problem in measure spaces,
  82nd Annual Meeting of the GAMM, Graz, Austria, April 18–21, 2011.
• L¹ data fitting for nonlinear inverse problems,
  Chemnitz Symposium on Inverse Problems, Chemnitz, Germany, September 23–24, 2010.
• Total variation regularized nonlinear inversion for parallel MRI with variable density sampling patterns,
  Workshop on Novel Reconstruction Strategies in NMR and MRI, Göttingen, Germany, September 9–11, 2010.
• Inverse source problems with L¹-type penalties,
  Inverse Problems: Modeling and Simulation Antalya, Turkey, May 20–24, 2010.
• Optimal control of PDEs with measures,
  Annual Meeting of the DMV München, Germany, March 8–12, 2010.
• A semismooth Newton method for optimal control problems in a measure space,
  14th Belgian-French-German Conference on Optimization Leuven, Belgium, September 14–18, 2009.
• Inverse problems with L¹ data fitting,
  Applied Inverse Problems, Wien, Austria, July 20–24, 2009.
• A predual formulation for PDE constrained optimization with total variation regularization,
  Optimization with PDE Constraints (OPTPDE) Warszawa, Poland, December 11–13, 2008.
• A direct method for the numerical time reversal of waves in a heterogeneous medium,
  6th International Congress on Industrial and Applied Mathematics (ICIAM) Zürich, Switzerland, July 16–20, 2007.
• A non-standard numerical method for variational data assimilation for a convection-diffusion equation,
  Applied Inverse Problems Vancouver, Canada, June 25–29, 2007.
• The quasi-reversibility method for thermoacoustic tomography in a heterogeneous medium,
  Applied Inverse Problems Vancouver, Canada, June 25–29, 2007.

Colloquia and seminars

• Iterative regularization of non-smooth ill-posed problems,
  Inverse Problems Seminar, The Chinese University of Hong Kong, November 17, 2022.
• Convex relaxation of hybrid discrete-continuous control problems,
  Seminar on Computational Engineering, LUT University, Lappeenranta, Finland (online), September 28, 2021.
• Optimal control of nonsmooth partial differential equations,
  Research Seminar Optimization, Humboldt-Universität zu Berlin (online), April 20, 2021.
• Optimal control of nonsmooth partial differential equations,
  IFIP WG 7.2 Virtual Seminar, Online, February 2, 2021.
• Nonsmooth regularization of a coefficient inverse problem for the wave equation,
  Mathematical Colloquium, Universidade Federal de Santa Catarina, Florianópolis, Brasil (online), October 30, 2020.
• Convex relaxation of hybrid discrete-continuous control problems,
  Mathematisches Kolloquium, Universität Düsseldorf, December 13, 2019.
• Multibang regularization of a coefficient inverse problem for the wave equation,
  Forschungsseminar Inverse Probleme und PDEs, TU Chemnitz, September 3, 2019.
• Accelerated primal-dual methods for structured non-convex optimization,
  Computational and Applied Mathematics Seminar, Chalmers University of Technology, Göteborg, Sweden, August 28, 2019.
• Generalized modes in Bayesian inverse problems,
  Forschungsseminar Mathematische Statistik, Humboldt-Universität Berlin, February 6, 2019.
• Nichtglatte Optimierung im Funktionenraum,
  Kolloquium Mathematik, Universität Paderborn, July 9, 2018.
• Inverse und schlecht gestellte Probleme,
  Fachschaftstagung Mathematik, Cusanuswerk, Uder, May 11, 2018.
• Variationsmethoden in der mathematischen Bildverarbeitung,
  Fachschaftstagung Mathematik, Cusanuswerk, Uder, May 11, 2018.
• Convex relaxation of hybrid discrete-continuous control problems,
  Institut für Mathematik, Universität Paderborn, March 13, 2018.
• Konvexe Relaxierung von gemischt-ganzzahligen Optimalsteuerproblemen,
  Department Mathematik, Friedrich-Alexander-Universität Erlangen-Nürnberg, February 5, 2018.
• Convex regularization of discrete-valued inverse problems,
  DAMUT Colloquium, Universiteit Twente, Netherlands, September 27, 2017.
• A primal–dual extragradient method for nonlinear inverse problems for PDEs,
  Institut für Numerische und Angewandte Mathematik, Georg-August-Universität Göttingen, August 10, 2017.
• Convex regularization of hybrid discrete-continuous control problems,
  MODUS Seminar, Universität Bayreuth, June 17, 2017.
• Convex relaxation of hybrid binary-continuous control problems,
  Optimization Seminar, Weierstraß-Institut für Angewandte Analysis und Stochastik, Berlin, March 29, 2017.
• Stochastic inverse problems with impulsive noise,
  Institute for Mathematics and Scientific Computing, Karl-Franzens-Universität Graz, March 15, 2017.
• Discrete regularization of parameter identification problems,
  Institut für Mathematik, Alpen-Adria-Universität Klagenfurt, November 16, 2016.
• A primal–dual extragradient method for nonlinear inverse problems for PDEs,
  Institute for Mathematics and Scientific Computing, Karl-Franzens-Universität Graz, September 28, 2016.
• Discrete regularization of parameter identification problems,
  Department of Mathematics and Statistics, University of Helsinki, August 25, 2016.
• Discrete regularization of parameter identification problems,
  Graduate School of Mathematics, University of Tokyo, August 12, 2016.
• Convex relaxation of hybrid binary-continuous regularization,
  School of Mathematical Sciences, Fudan University, Shanghai, August 2, 2015.
• Convex relaxation of hybrid binary-continuous problems,
  Sandia National Laboratories, Albuquerque, New Mexico, March 23, 2015.
• Sparse optimization of PDEs with application to light source placement,
  Kolloquium des FR Mathematik, Universität des Saarlandes, Saarbrücken, February 6, 2015.
• Sparse optimization of PDEs with application to light source placement,
  Kolloquium Nonlinear Science, Universität Münster, January 27, 2015.
• Convex relaxation of hybrid binary-continuous penalties,
  Applied Mathematics Seminar, Universität Münster, November 19, 2014.
• Sparse optimization of PDEs with application to light source placement,
  Inverse Problems Seminar, University College London, October 10, 2014.
• Wieviel Mathematik steckt im “Kernspin”?,
  1. WissensNacht Ruhr, Essen, October 2, 2014.
• Nichtglatte Optimierung im Funktionenraum,
  Duisburger Arbeitskreis für Mathematik in Praxis und Forschung, Duisburg, May 27, 2014.
• A convex analysis approach to hybrid binary-continuous optimal control problems,
  Applied Mathematics Seminar, University of California, Riverside, May 23, 2014.
• A convex analysis approach to hybrid binary-continuous optimal control problems,
  Applied Analysis Seminar, Cambridge University, April 28, 2014.
• A convex analysis approach to hybrid binary-continuous optimal control problems with application to multi-bang controls,
  Institut für Mathematik, Alpen-Adria-Universität Klagenfurt, January 14, 2014.
• Multibang control of elliptic equations,
  Zentrum Mathematik, Technische Universität München, December 17, 2013.
• Parameter identification problems with non-Gaussian noise,
  Lothar Collatz Colloquium, Universität Hamburg, May 16, 2013.
• Numerische Optimierung im Maßraum,
  Mathematisches Institut, Universität Bayreuth, April 17, 2013.
• Numerische Optimierung im Maßraum,
  Institut für Mathematik, Humboldt-Universität zu Berlin, February 11, 2013.
• Parameter identification problems with non-Gaussian noise,
  Graduate School of Mathematics, University of Tokyo, January 24, 2013.
• Parabolic control problems in measure spaces,
  Oberseminar Wissenschaftliches Rechnen, Julius-Maximilians-Universität Würzburg, June 5, 2012.
• Parameteridentifizierung mit Impulsrauschen,
  Fakultät für Mathematik, Universität Duisburg-Essen, January 27, 2012.
• Inverse Problems with non-smooth noise models,
  Colloquium, Helmholtz Zentrum München, October 27, 2011.
• A semi-smooth Newton method for nonlinear inverse problems with L¹ data fitting,
  Inverse Problems group seminar, RICAM, Linz, February 18, 2011.
• A primal-dual semi-smooth Newton method for L¹ data fitting,
  Institute of Computational Mathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing, August 24, 2010.
• PDE-constrained optimization with L¹-type functionals,
  Institute of Computational Mathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing, August 18, 2010.
• PDE-constrained optimization with L¹-type functionals,
  AG Numerics, Universität Konstanz, April 14, 2010.
• Inverse problems with L¹ fitting,
  Fuzzy Logic Labs seminar, Johannes-Kepler Universität Linz, July 13, 2009.
• Basic Principles of (P)MRI,
  Optimization seminar, Karl-Franzens-Universität Graz, December 3, 2008.
• Time Reversal and Thermoacoustic Tomography,
  Colloquium of the Institute for Numerical and Applied Mathematics, Georg-August-Universität Göttingen, October 30, 2007.
• A direct method for the numerical time reversal of waves in a heterogeneous medium,
  Optimization seminar, Karl-Franzens-Universität Graz, May 2, 2007.
• A direct method for the numerical time reversal of waves in a heterogeneous medium,
  Inverse Problems group seminar, RICAM, Linz, March 6, 2007.