Mathematical Data Analysis

19.10.2022: First meeting to asign dates and topics and first talk

       Learned operator correction in context of nano CT (Ehlers)

26.10.2022: Introducing learning into a primal-dual algorithm (Jabs)

02.11.2022: Generative Autoencoders using Normalizing Flows (Käsbohrer)

09.11.2022:TBA

16.11.2022:TBA

23.11.2022: TBA

30.11.2022: On the convergence of a class of ADAM type algorithms - talk is cancelled

07.12.2022: TBA (Horn)

14.12.2022:TBA

21.12.2022: Curse of Dimensionality - talk is cancelled

11.01.2023: TBA (Hudaff)

18.01.2023: Learning the invisible: A hybrid deep learning-shearlet framework for limited angle CT (Marquardt)

25.01.2023: TBA (Lewerenz)

05.04.2022

no seminar

12.04.2022

First meeting to asign dates and topics

19.04.2022

Ehlers Introduction to learned operator correctin in context of nano CT

26.04.2022

Albrecht, Generalized interpolation in reproducing kernel Hilbert spaces

03.05.2022

Andrikyan, Exact reconstruction of sparse exponential sums from Fourier coefficients

10.05.2022

Saleh, Augmented spectral methods for solving variational problems

17.05.2022

31.05.2022

07.06.2022

14.06.2022

21.06.2022

Ahmad, Deep Learning: An Introduction for Applied Mathematicians

28.06.2022

Lalovic, Learned convex regularizers for inverse problems

05.07.2022

Jensen, Learning optical flow for fast MRI reconstruction

12.07.2022

Reincke, Directional sinogram inpainting for limited angle tomography

02.11.2021: no seminar

09.11.2021: Learning the regularization parameter (Jabs)

16.11.2021: no seminar

23.11.2021: Dimension reduction and stability for kernel regression

30.11.2021:  tba (Käsbohrer)

07.12.2021:  tba (Goetz)

14.12.2021:  tba (Saleh)

      afternoon: Xmas market visit at 5 pm

04.01.2021: tba (Saarinen)

11.01.2021 : Model reduction and neural networks for parametric PDEs  (Diaz Florez)

18.01.2021: tba (Sheydaei)

25.01.2021: tba (Albrecht)

06 April 2021: First meeting

14 April 2021: Compression of system matrices in magnetic particle imaging with convoluted tensor products of Chebyshev polynomials (Scheffler)

21 April 2021: Multi-bang regularization for electrical impedance tomography (Kreyziu)

28 April 2021: no seminar

05 May 2021: Manifold Learning (Dhola) – talk is cancelled!

12 May 2021: Dynamic MPI reconstruction using Splines (Schmidt)

19 May 2021: tba (Albrecht)

26 May 2021: tba (Jabs)

02 June 2021: Dynamic CT reconstruction using the approximate inverse (Juerss)

09 June 2021: A Kaczmarz-type sequential subspace optimization method for dynamic CT reconstruction (Ehlers)

16 June 2021: tba (Dunst)

23 June 2021: Variational reconstruction method for undersampled dynamic X-ray tomography (Gyawali)

30 June 2021: tba (Käsbohrer)

07 July 2021: tba (Funk)

25 November 2020: Active learning: theory and application (Saleh)

02 December 2020: Introduction to magnetic particle imaging (Entzian)

09 December 2020: tba (Zdun)

16 December 2020: Error estimates for approximation of multibang control (Do)

06 January 2021: tba (Beckmann)

13 January 2021: tba (Dziwnik)

20 January 2021: High dimensional statistics – PCA in high dimensions and Stein's phenomenon (Eggers)

27 January 2021: tba (Hudaff)

03 February 2021: Manifold Learning (Dhola)

10 February 2021: Random walks on graphs (Vieregg)

17 February 2021: cancelled (Singh)

24 February 2021:

• Deep generative modelling (Käsbohrer)
• Bayesian regression and Gaussian processes (Saarinen)

04 May 2020: On a non-linear inverse problem involving the Radon - transform (Beckmann)

11 May 2020: Usage of the Bayesian Framework to improve the MPI reconstruction in case of noised magnetic fields (Grün)

18 May 2020: Graph spectral image processing over adaptive triangulations (Wagner)

25 May 2020: Dynamic Computerized Tomography - Modeling and Iterative Reconstruction (Blanke)

08 June 2020: Kernel-based methods in Computerized Tomography (Albrecht)

15 June 2020:

• cancelled (Guillemard)
• Approximate inverse for linear problems (Schaub)

22 June 2020: K-transform tomography - applications in nuclear verification (Fichtlscherer)

29 June 2020: Dynamic concentration reconstruction for magnetic particle imaging using splines (Schmidt)

06 July 2020: tba (Dziwnik)

13 July 2020:

• tba (Goetz)
• Dynamic linear inverse problems (Kreyziu)

13 November 2019: Discrete regularization parameter idendification problems (Do)

20 November 2019: Solvers for the generalized Riemann problem - greatest hits and news from the lab (Goetz)

27 November 2019: cancelled

04 December 2019: Reconstructing dynamic tracer concentrations from Magnetic Particle Imaging measurements (Schmidt)

11 December 2019: Axisymmetric (Surface) Diffusion: Dynamics and Stability of Self-Similar Pinchoff (Dziwnik)

18 December 2019: cancelled

08 January 2020: tba (Albrecht)

15 January 2020: A tractable approach for 1-bit compressed sensing on manifolds (Krause-Solberg)

Abstract: A tractable approach for 1-bit compressed sensing on manifolds

Compressed Sensing deals with reconstructing some unknown vector from few linear measurements in high dimension by additionally assuming sparsity, i.e. many entries are zero. Recent results guaranteed recovery even when just signs of the measurements are available (one-bit CS). A natural generalization of classical CS replaces sparse vectors by vectors lying on manifolds having low intrinsic dimension. In this talk I introduce the one-bit problem and proposes a tractable strategy to solve one-bit CS problems for data lying on manifolds. This is based on joint work with Johannes Maly and Mark Iwen.

22 January 2020: The K-Transform - how inverse problems can be used for nuclear disarmament (Fichtlscherer)

29 January 2020: tba (Scharmacher)