Tervetuloa, Welcome, Willkommen!
About me
I am an applied mathematician and assistant professor for computational and mathematical methods for imaging at the University of Hamburg. Therefore, I am member of Center of Optimization and Approximation.
My actual research covers large-scale inverse problems in biological and medical applications such as for example fluorescence microscopy, photo acoustic tomography and magnetic particle imaging. More precisely, I am working on variational regularization methods, dynamic inverse problems, Bayesian inversion, and approximation error modelling.
News
Open PhD positions
I am currently looking for two PhD-students who would like to work on inverse problems related to medical imaging.
New paper
Our paper "Improved image reconstruction in magnetic particle imaging using structural a priori information" is accepted by IJMPI.
AIP 2017
Our mini-symposium "Mathematical Imaging with Magnetic Nanoparticles" is accepted for the AIP 2017
My research
Article
Bathke, C.; Kluth, T.; Brandt, C. & Maaß, P.: Improved image reconstruction in magnetic particle imaging using structural a priori information. International Journal On Magnetic Particle Imaging, 3(1):2017.online availble here
Storath, M.; Brandt, C.; Hofmann, M.; Knopp, T.; Salamon, J.; Weber, A. & Weinmann, A.: Edge preserving and noise reducing reconstruction for magnetic particle imaging. IEEE Transactions on Medical Imaging, 36(1):74-85, 2017.
doi:10.1109/TMI.2016.2593954
Brandt, C., Maass, P., Piotrowska-Kurczewski, I., Schiffler, S., Riemer,O., and Brinksmeier, E.: Mathematical methods for optimizing high precision cutting operations. International Journal of Nanomanufacturing, 8(4):306–325, 2012.
doi:10.1504/IJNM.2012.048580.
Brandt, C., Niebsch, J., Ramlau, R., and Maass, P.: Modeling the influence of unbalances for ultra-precision cutting processes. ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, 91(10):795–808, 2011.
doi:10.1002/zamm.201000155.
Piotrowska, I., Brandt, C., Karimi, H. R., and Maass, P.: Mathematical model of micro turning process The International Journal of Advanced Manufacturing Technology, Volume 45(1):33–40, 2009.
doi:10.1007/s00170-009-1932-z.
Brandt,C., Niebsch, J., and Vehmeyer, J.: Modelling of ultra-precision turning process in consideration of unbalances. Advanced Materials Research, 223:839–848, 2011.
doi:10.4028/www.scientific.net/AMR.223.839
Gossiaux, P.B., Aichelin, J., Brandt, C., Gousset, T., and Peigné, S.: Energy loss of a heavy quark produced in a finite-size quark-gluon plasma. Journal of Physics G: Nuclear and Particle Physics, 34(8):S817, 2007.
doi:10.1088/0954-3899/34/8/S103.
Gossiaux, P.B., Peigné, S., Brandt, C., and Aichelin, J.: Energy loss of a heavy quark produced in a finite size medium. Journal of High Energy Physics, 4(04):012, 2007.
doi:10.1088/1126-6708/2007/04/012.
Thesis
Brandt, C.: Regularization of Inverse Problems for Turning Processes. Ph.D. thesis, University of Bremen, Logos, 2012available by Logos
Book chapter
Andres, M., Blum, H., Brandt, C., Carstensen, C., Maass, P., Niebsch, J., Rademacher, R., Ramlau, R., Schröder, A., Stephan, E.-P., and Wiedemann, S.: Process Machine Interactions, Adaptive finite elements and mathematical optimization methods. Lectures Notes in Production Engineering. Springer, 2013.doi:DOI:10.1007/978-3-642-32448-2.
Brandt, C., Krause, A., Niebsch, J., Vehmeyer, J., Brinksmeier, E., Maass, P., and Riemer, O.: Process Machine Interactions, Surface Generation Process with Consideration ot the Balancing State in Diamond Machining. Lectures Notes in Production Engineering. Springer, 2013.
doi:DOI: 10.1007/978-3-642-32448-2.
Piotrowska-Kurczewski, I., Brandt, C., Maass, P., and Riemer, O.: Micro Metal Forming, chapter Simulation technologies - Inverse Modelling, pages 368–379. Springer, 2013.
Brandt, C., Piotrowska, I., Karimi, H., Niebsch, J., Ramlau, R., Krause, A., Riemer, O., and Maass, P.: Process machine interaction model for turning processes. International Journal of Control Theory and Applications, 1(2):145–153, 2008.
Conference proceedings (reviewed)
Storath, M., Brandt, C., Hofmann, M., Knopp, T. , Weber, A., Weinmann, A.: Fused lasso regularization for magnetic particle imaging. Proceedings of the International Workshop on Magnetic Particle Imaging 2016, March 16-18. 2016, Lübeck, Germany, 2016.Brandt, C., Niebsch, J., and Vehmeyer, J.: Modelling of ultra-precision turning process in consideration of unbalances. In Outeiro, J.C., editor, Proceedings of the 13th CIRP Conference on Modeling of Machining Operations, May 12-13. 2011, Sintra, Portugal, volume 223, pages 839–848. 2011. www.scientific.net/AMR.223.839>
Niebsch, J., Ramlau, R., and Brandt, C.: On the interaction of unbalances and surface quality in ultra-precision cutting machinery. In SIRM 2011, Darmstadt, Germany. 2011.
Brandt, C., Niebsch, J., Maass, P., and Ramlau, R.: Simulation of process machine interaction for ultra precision turning. In Proceedings of the 2nd International Conference on Process Machine Interactions, June 10-11, 2010, Vancouver, Canada. 2010.
Brandt, C., Krause, A., Brinksmeier, E., and Maass, P.: Force modelling in diamond machining with regard to the surface generation process. In Proceedings of the 9th International Conference and Exhibition on Laser Metrology, machine tool, CMM and robotic performance, LAMDAMAP 2009, London, 30.06.-02.07.2009, pages 377–386. 2009.
Gossiaux, P.B., Peigné, S., Brandt, C., and Aichelin, J.: Energy loss of a heavy quark produced in a finite-size quark-gluon plasma
doi:10.1088/0954-3899/34/8/S103. QM2006 Proceedings; 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (QM2006), Shanghai, China, November 14-20, 2006.
2016
Inverse problems seminar at Helsinki University, 15.6.2016
Helsinki, Finland
Invited by Samuli Siltanen
SIAM Imaging 2016
23.-26.5.2016, Albuquerque, USA
Invited by Cecile Louchet
International Workshop on Magnetic Particle Imaging IWMPI 2016
16.-18.3.2016, Lübeck, Germany
2015
Inverse Days 2015, 8.-10.12.2015
Lappeenranta, Finland
Mini-symposium on "Mathematical Methods for MPI" at the DMV 2015, 21.-25.9.2015,Hamburg
Invited by Wolfgang Erb
Applied Inverse Problems 2015
May 2015, Helsinki, Finland
2014
Seminar AG Imaging, University Münster,
3.12.2014
Invited by Martin Burger
DSR seminar at the Helmholtz Institut München
7.7.2014
Invited by Frank Filbir
Sparse Image Reconstruction for Photoacoustic Tomography Using Shearlets
Workshop "Wavelets and Applications"
22.5.2014, Université Libre de Bruxelles, Belgium
Invited by Christine de Mol
SIAM Conference on Imaging Science
12-14.5.2014, Hongkong, China
Mecklenburger Workshop "Approximationsmethoden und schnelle Algorithmen, 17-20.03.2014, Hasenwinkel
2013
Advances In Mathematical Image Processing, 30.09.-2.10.2013, Annweiler
Applied Inverse Problems Conference AIP 2013, 1.-5.07.2013, Daejeon, Korea
2012
Inverse Problems: Modelling and Simulation 2012, 21.-26.05.2012, Antalya, Turkey
Oberseminar Analysis Universität Osnabrück, 14.05.2013, Osnabrück
(invited talk)
Winterseminar der AG Technomathematik der Universität Bremen, 2012, 28.-29.2.2912, Ganderkesee
Magnetic Particle Imaging (MPI) is a novel imaging modality for biomedical diagnostics that determines the spatial distribution of magnetic nanoparticles by measuring the non-linear magnetization response of the particles to an applied magnetic field. The advantages of MPI are the high dynamic spatial and temporal resolution and that it does not employ any ionizing radiation.
Actual research projects on MPI
Bimodal reconstructions for MRI-MPI, joint work with Christine Bathke, Tobias Kluth and Peter Maass
Joint reconstruction in multi-color MPI, joint work with Martin Storath, Martin Hofmann and Tobias Knopp
Approximation error modelling for model-based MPI, joint work with Aku Seppänen
Time based regularization for 4D MPI, joint work Andreas Hauptmann
It is a joint research within of the scientific network "Mathematical methods for Magnetic Particle Imaging (MIEM). The network funded by the DFG consists of 9 researchers and it is lead by Dr. Wolfgang Erb from the University of Lübeck. For more information, see the official MIEM homepage.
The main objective of this research is the development of mathematical methods for three imaging modalities in biological and medical applications: fluorescence microscopy (FM), photo-acoustic tomography (PAT) and magnetic particle imaging (MPI). All imaging applications have in common that the desired object such as in PAT and MPI the cancer cell in the human body is not directly observable but can be measured only indirectly.
In order to reconstruct the desired object, one has to solve the so-called inverse problem. In this project, mathematical methods for solving inverse problems are developed which consider modelling errors and uncertainties of the underlying models in the inversion. It is expected that the image reconstruction quality will be increased significantly in all three applications. In particular, the improvements are assumed to contribute to the development of PAT and MPI as medical imaging techniques in clinical practice.
This project is founded by the Academy of Finland.
online availible here
Brandt, C.; Seppänen, A. : Recovery from errors due to domain truncation in magnetic particle imaging -- approximation error modeling approach, submitted
More generally my research interests are :
- Medical and biological imaging
- Modelling and simulation
- Regularization with sparsity constraints
- Bayesian inversion and approximation error modelling
Collaborations
Dr. Martin Storath
Image Analysis and Learning GroupUniversity of Heidelberg
Prof. Tobias Knopp, Dr. Martin Hofmann
Universitätsklinikum Hamburg-EppendorfSektion für Biomedizinische Bildgebung
Institut für Biomedizinische Bildgebung
Technische Universität Hamburg
Dr. Wolfgang Erb
Institut für MathematikUniversität zu Lübeck
Prof. Maass, Christine Bathke
Center for Industrial MathematicsUniversiy of Bremen
Andreas Hauptmann
University of HelsinkiFinnland
Aku Seppänen
University of Eastern FinlandKuopio, Finland
Teaching
Actual courses
Optimization
I will give the master course and the exercises on optimization in infinite dimensional spaces during summer semester 2017.
Supervision of theses
I am offering topics for thesis such that inverse problems, image reconstruction and Bayesian inversion related to applications in bio/medical imaging. Current theses are:- Tuukka Heiskanen, Superresolution in microscopy, Bachelor thesis, University of Eastern Finland
- Thomas Yu, Optimization for HDR brachytherapy, Master thesis, University of Hamburg, supervision together with Prof. Schlaefer, TUHH
- Federico Lucchesi, Adversarial domain adaption for semantic segmentation Master thesis, Unversity of Hamburg, supervision together with Prof. Vazquez, Universitat Autònoma de Barcelona
Previous Courses
Inverse Problems
Exercises on inverse problems during winter semester 2016
Inverse Problems
together with Prof. Kunis (Summer semester 2014)
Inverse Problems occur in many applications in science, medicine and technology.
The course will cover the classical regularization theory for linear inverse problems .
Literature
Rieder,
Keine Probleme mit Inversen Problemen
Hanke, Engl, Neubauer,
Regularization of Inverse Problems
Louis,
Inverse und schlecht gestellte Probleme
Mathematics I for production engineering
2 tutorials during winter semester 2012
Analysis II
2 tutorials during summer semester 2012
Supervised theses and projects
- Tuukka Heiskanen, Deconvolution in fluorescence microscopy, Summer trainee 2016, University of Eastern Finland
- Phil Gralla, Mathematical methods for controlling ultra precise processes of machining, Bsc 2012, Secondary Supervisor with Dr. I. Piotrowska, University of Bremen.
- Philipp Welz, Regenerative chattering for micro cutting processes, Bsc 2011, together with Prof. P. Maass, University of Bremen.
- Florian Dollinger, A continuous model for determination of dwell periods for a form corrective polishing process, Diploma thesis 2010 , Secondary supervision with Dr. I. Piotrowska, University of Bremen.
- Thi Bach, Mathematical optimization of micro polishing, Student project (12 month) 2010, Main supervision together with Dr. I. Piotrowska, University Bremen.
Short CV
Academic positions
Since 03 2017
Assistant professor at the University of Hamburg.
Research group: Mathematical and computational methods in medical imaging
09/2015 - 02 2017
Academy post-doctoral researcher in the Inverse Problems group at the Eastern University of Finland in Kuopio.
- Academy of Finland project "Approximation error modelling in large scale inverse problems in imaging" (2015-2018)
04/2013 - 08/2015
Post-doctoral researcher in the research group "Applied and Numerical Analysis" at the University Osnabrück working within the
- Helmholtz young investigator group "Fast algorithms for biomedical imaging" (Helmholtz Zentrum München)
01/2008 - 04/2013
Research assistant in the at the WG Industrial Mathematics at the Center for Industrial Mathematics at the University Bremen, working within the
- DFG priority program SPP1180, project "Mathematical methods for precision balancing of machine tool" (2008-2011)
- SFB "Micro cold forming" (2012-2013)
11/2007 - 12/2007
Research assistant in the research group "Solid physics" at the University Rostock, working within the SFB 652, project B1 Exciton matter in mesoscopic potentials
- Tasks: Implementation of a phase retrieval algorithm for ultrashort laser pulses
Education
2008 - 2012
Doctoral studies in the research group "Industrial mathematics" at the University Bremen
2012: Doctorate degree in mathematics, University Bremen
- Thesis: "Regularization of Inverse Problems for Turning Processes"
- Supervisor: Prof Peter Maass
10/2001 - 08/2007
08/2007
Diploma studies in mathematics , University Rostock
Diploma degree in mathematics, University Rostock
- Thesis: "Numerical phase reconstruction" (Numerical phase retrieval)
- Supervisor: Prof Manfred Tasche
10/2002 - 08/2007
10/2006 - 07/2006
08/2007
Diploma studies in physics, University Rostock
Master studies in physics, Erasmus exchange program, University Nantes
Master degree in physics, University Nantes (France)
- Master thesis: "Energy loss of a parton in a quark-gluon-plasma"
- Supervisor: Stéphane Peigné
Contact me
Office adress
Universität HamburgDepartment of Mathematics
Bundesstraße 55
20146 Hamburg
Office: Geomatikum 104
Phone: +49 -40 42838 4076
Mail: Christina.Brandt(ad)uni-hamburg.de
Postal address
Universität HamburgFachbereich Mathematik
Bundesstraße 55
20146 Hamburg
Germany