Talks

• 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 non-smooth non-convex 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, August 30-September 3, 2021 (online).
   
• 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, April 12-20, 2021 (online).
   
• 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, October 4-10, 2020 (online).
   
• Convex relaxation 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, 
  Computational Methods for New Directions in Inverse Problems, Texas A&M University, College Station, TX, USA, February 3-5, 2020.
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  First Indo-German Conference on Computational Mathematics, 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 nonsmooth equations, 
  Workshop "New Trends in PDE-Constrained Optimization", Special Semester on Optimization, RICAM Linz, Austria, November 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 26-26, 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", Technische Universität München, 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 the Korean Mathematical Society and the German Mathematical Society., Seoul, 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, 
  27th 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, TU Wien, Vienna, Austria, February 21-23, 2018.
   
• Convex regularization of discrete-valued inverse problems, 
  Workshop "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 Partial Differential Equations", 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 and effective algorithms for imaging and vision", 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 Conference, Hangzhou, China, May 29-June 2, 2017.
   
• Adaptive discretization and first-order methods for nonsmooth inverse problems for PDEs, 
  Turing/LMS Workshop "Inverse Problems and Data Science", Edinburgh, UK, May 8-10, 2017.
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  Workshop "Numerical Methods for Optimal Control and Inverse Problems", Technische Universität München, 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, 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 Approximation and Optimization in the Caribbean, 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, Berlin, Germany, 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 Conference, 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.
   
• Multi-bang control of elliptic equations, 
  SIAM Conference on Optimization, San Diego, California, May 19-22, 2014.
   
• Multi-bang control of elliptic equations, 
  Workshop "Numerical Methods for Optimal Control and Inverse Problems", Technische Universität 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 8-13, 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 Conference, Daejeon, South Korea, July 1-5, 2013.
   
• Optimal control of elliptic PDEs with positive measures, 
  Workshop "Numerical Methods for Optimal Control and Inverse Problems", Technische Universität 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-infinity 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", Technische Universität München, Germany, March 12-14, 2012.
   
• A measure space approach to optimal source placement, 
  Workshop "Optimization with PDE constraints", Charles University 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 TC 7 Conference, Berlin, Germany, September 12-16, 2011.
   
• A measure space approach to optimal source placement, 
  25th IFIP TC 7 Conference, Berlin, Germany, September 12-16, 2011.
   
• Autocalibrated parameter choice for non-smooth noise models, 
  Applied Inverse Problems Conference, Texas A&M University, College Station, Texas, USA, May 23-27, 2011.
   
• L1 data fitting for parameter identification problems for PDEs, 
  Applied Inverse Problems Conference, Texas A&M University, 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. 
  [movies (mp4): slide 22, slide 23]
   
• 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 Conference, Wien, Austria, July 20-24, 2009.
   
• A predual formulation for PDE constrained optimization with total variation regularization, 
  Optimization with PDE Constraints (OPTPDE), Warsaw, 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 Conference, Vancouver, Canada, June 25-29, 2007.
   
• The quasi-reversibility method for thermoacoustic tomography in a heterogeneous medium, 
  Applied Inverse Problems Conference, Vancouver, Canada, June 25-29, 2007.

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• 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, September 28, 2021.
   
• Optimal control of nonsmooth partial differential equations, 
  Research Seminar in Optimization, Humboldt-Universität zu Berlin, April 20, 2021.
   
• Optimal control of nonsmooth partial differential equations, 
  IFIP WG 7.2 Virtual Seminar, February 2, 2021.
   
• Nonsmooth regularization of a coefficient inverse problem for the wave equation, 
  Mathematical Colloquium, Universidade Federal de Santa Catarina, Florianópolis, Brasil, October 30, 2020 (online).
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  Mathematisches Kolloquium, Heinrich-Heine-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, Humbold-Universität Berlin, February 9, 2019.
   
• Nichtglatte Optimierung im Funktionenraum, 
  Kolloquium Mathematik, Universität Paderborn, July 9, 2018.
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  Universität Paderborn, March 13, 2018.
   
• Convex regularization of discrete-valued inverse problems, 
  Universiteit Twente, Enschede, Netherlands, September 27, 2017.
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  Universität Bayreuth, June 16, 2017.
   
• Convex relaxation of hybrid discrete-continuous control problems, 
  Weierstraß-Institut für Angewandte Analysis und Stochastik, Berlin, March 29, 2017.
   
• Stochastic inverse problems with impulsive noise, 
  Karl-Franzens-Universität Graz, March 15, 2017.
   
• Discrete regularization of parameter identification problems, 
  Alpen-Adria-Universität Klagenfurt, November 16, 2016.
   
• A primal-dual extragradient method for nonlinear inverse problems for PDEs, 
  Karl-Franzens-Universität Graz, September 28, 2016.
   
• Discrete regularization of parameter identification problems, 
  University of Helsinki, August 25, 2016.
   
• Discrete regularization of parameter identification problems, 
  University of Tokyo, August 12, 2016.
   
• Convex relaxation of hybrid discrete-continuous regularization, 
  Fudan University, Shanghai, August 2, 2015.
   
• Convex relaxation of hybrid discrete-continuous problems, 
  Sandia National Laboratories, Albuquerque, March 23, 2015.
   
• Sparse optimization of PDEs with application to light source placement, 
  Kolloquium der FR Mathematik, Universität des Saarlandes, Saarbrücken, February 6, 2015.
   
• Sparse optimization of PDEs with application to light source placement, 
  Colloquium Nonlinear Science, Westfälische Wilhelms-Universität Münster, January 27, 2015.
   
• Convex relaxation of hybrid binary-continuous penalties, 
  Westfälische Wilhelms-Universität Münster, November 19, 2014.
   
• Sparse optimization of PDEs with application to light source placement, 
  University College London, October 10, 2014.
   
• Wieviel Mathematik steckt im "Kernspin"?, 
  WissensNacht Ruhr, Essen, October 2, 2014.
   
• Nichtglatte Optimierung im Funktionenraum, 
  Duisburger Arbeitskreis für Mathematik in Forschung und Praxis, May 27, 2014.
   
• A convex analysis approach to hybrid binary-continuous optimal control problems, 
  University of California, Riverside, May 23, 2014.
   
• A convex analysis approach to hybrid binary-continuous optimal control problems, 
  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.
   
• Multi-bang 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, 
  Universität Bayreuth, April 17, 2013.
   
• Numerische Optimierung im Maßraum, 
  Humboldt-Universität zu Berlin, February 11, 2013.
   
• Parameter identification problems with non-Gaussian noise, 
  University of Tokyo, January 24, 2013.
   
• Parabolic control problems in measure spaces, 
  Julius-Maximilians-Universität Würzburg, June 5, 2012.
   
• Parameteridentifizierung mit Impulsrauschen, 
  Universität Duisburg-Essen, January 27, 2012.
   
• Inverse problems with non-smooth noise models, 
  Helmholtz Zentrum München, October 27, 2011.
   
• A semi-smooth Newton method for nonlinear inverse problems with L1 data fitting, 
  RICAM, Linz, February 18, 2011.
   
• A primal-dual semi-smooth Newton method for nonlinear 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, 
  Universität Konstanz, April 14, 2010.
   
• Inverse problems with L1 data fitting: A semismooth Newton method and automatic parameter choice, 
  Johannes-Kepler Universität Linz, July 13, 2009.
   
• Basic Principles of (P)MRI, 
  Karl-Franzens-Universität Graz, December 3, 2008. 
  (very informal; animations missing; caution: ~7MB)
   
• Time Reversal and Thermoacoustic Tomography, 
  Georg-August-Universität Göttingen, October 30, 2007.
   
• A direct method for the numerical time reversal of waves in a heterogeneous medium, 
  Karl-Franzens-Universität Graz, May 2, 2007.
   
• A direct method for the numerical time reversal of waves in a heterogeneous medium, 
  RICAM, Linz, March 6, 2007.

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