Sebastian Krämer, M.Sc.

Institut für Geometrie und Praktische Mathematik
RWTH Aachen
Templergraben 55
52056 Aachen
Germany

advisor:
Lars Grasedyck

office:
Hauptgegbäude 104.2
phone:
+49 241 80-80-94875
fax:
+49 241 80-92317
email:
kraemer@igpm.rwth-aachen.de

Publications

S. Krämer, The Geometrical Description of Feasible Singular Values in the Tensor Train Format.
Preprint. 		[arXiv]
L. Grasedyck and S. Krämer, Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion.
Preprint.		 [IGPM]
[arXiv]
L. Grasedyck, M. Kluge, and S. Krämer, Variants of alternating least squares tensor completion in the tensor train format.
SIAM Journal on Scientific Computing 37(5):A2424--A2450, 2015. 		[epubs.siam]

Repositories

TT Feasibility Toolbox
Mini-toolbox for "A Geometrical Description of Feasible Singular Values in the Tensor Train Format". 		[Git Repository]
[Live Script Walkthrough]

Other Implementations

SALSA from "Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion". A C++ implementation is in progress. [Matlab Implementation]
ADF/ALS from "Variants of Alternating Least Squares Tensor Completion in The Tensor Train Format". This version is not user-friendly and the algorithm has been superseded by SALSA. Please have a look into it instead. [C Implementation]

Presentations (with updated titles)

L. Grasedyck and S. Krämer: The Geometrical Description of Feasible Singular Values in the Tensor Train Format:
Talk: Geometrical Description of Feasible Singular Values in Tree Tensor Formats
SIAM Conference on Applied Linear Algebra (SIAM-ALA18), Hong Kong, 2018		 [LINK]
Talk: Feasible Singular Values for Hierarchical Tensors
Algebraic Geometry, Approximation, and Optimisation, Creswick, Australia, 2018		 [LINK]
Poster: The Geometrical Description of Feasible Singular Values in the Tensor Train Format.
Workshop A1, FoCM '17 (2nd), Barcelona, Spain, 2017		 [LINK]
Talk: The Geometrical Description of Feasible Singular Values in the Tensor Train Format.
GAMM Jahrestagung, Weimar, Germany, 2017		 [LINK]
L. Grasedyck and S. Krämer: Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion:
Talk: Stable ALS Approximation for Rank-Adaptive Tensor Completion.
GAMM Jahrestagung, Munich, Germany, 2018		 [LINK]
Poster: Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion.
Workshop B7, FoCM '17 (2nd), Barcelona, Spain, 2017		 [LINK]
Talk: Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion.
UNCECOMP (2nd), Rhodes, Greece, 2017		 [LINK]
Talk: Stable ALS Approximation in the TT-Format for Rank-Adaptive Tensor Completion.
METT VII, Pisa, Italy, 2017		 [LINK]
Talk: Semi-Implicit Rank Adaption for Alternating Tensor Completion in the TT Format.
ILAS, Leuven, Belgium, 2016		 [LINK]
L. Grasedyck, M. Kluge, and S. Krämer: Variants of Alternating Least Squares Tensor Completion in The Tensor Train Format:
Talk: A Variant of Alternating Least Squares Tensor Completion in the TT-Format.
Siam Conference on Applied Linear Algebra, Atlanta, USA, 2015 		[LINK]
Poster: A Variant of Alternating Least Squares Tensor Completion in the TT-Format.
Workshop: Low-rank Optimization and Applications (Hausdorff Center for Mathematics), Bonn, Germany, 2015 		[LINK]

Main Teaching

Begleitpraktikum II (for mathematicians) [SS18]
Numerische Mathematik IV (for mathematicians) [WS1718]
Numerische Mathematik (for electrical engineers) [SS17]
Numerische Mathematik IV (for mathematicians) [WS1617]
Seminar "Aktuelle Themen der Numerik" (for mathematicians) [SS16]
Numerische Multilineare Algebra (for mathematicians) [SS16]
Numerische Mathematik III (for mathematicians) [WS1516]
Numerische Mathematik II (for mathematicians) [SS15]
Numerische Mathematik I (for mathematicians) [WS1415]
Begleitpraktikum I / II (for mathematicians, during studies) [2009-2011, 2012-2014]