Maren Klever, M.Sc.

Research Interests

• Low-rank tensor formats and tree tensor networks
• Non-negative matrix and tensor factorization
• High-dimensional approximation under constraints
• High-dimensional problems in medical applications, in particular, for tumor progression modeling via Mutual Hazard Networks

Research Project

• Tensorapproximationsmethoden zur Modellierung von Tumorprogression (DFG GR-3179/6-1)
  Interdisciplinary research project together with Lars Grasedyck, Rudolf Schill, Rainer Spang, and Tilo Wettig

Preprints and Publications

• Simon Pfahler*, Peter Georg, Rudolf Schill, Maren Klever, Lars Grasedyck, Rainer Spang, and Tilo Wettig
  Taming numerical imprecision by adapting the KL divergence to negative probabilities
  In: Statistics and Computing, Vol. 34, No. 5, 2024-08
  DOI: 110.1007/s11222-024-10480-y
• Kevin Rupp*, Andreas Lösch, Y. Linda Hu, Chenxi Nie, Rudolf Schill, Maren Klever, Simon Pfahler, Lars Grasedyck, Tilo Wettig, Niko Beerenwinkel*, and Rainer Spang*
  Modeling metastatic progression from cross-sectional cancer genomics data
  In: Bioinformatics, Volume 40, Issue Supplement_1, pages i140–i150, 2024-07
  DOI: 10.1093/bioinformatics/btae250
• Lars Grasedyck, Maren Klever*, and Sebastian Krämer
  Quasi-orthogonalization for alternating non-negative tensor factorization
  In: ETNA - Electronic Transactions on Numerical Analysis, pages 22-57, 2024-07
  DOI: 10.1553/etna_vol62s22
• Rudolf Schill*, Maren Klever, Andreas Lösch, Y. Linda Hu, Stefan Vocht, Kevin Rupp, Lars Grasedyck, Rainer Spang, and Niko Beerenwinkel
  Overcoming Observation Bias for Cancer Progression Modeling
  In: Research in Computational Molecular Biology, Lecture Notes in Computer Science (LNCS, volume 14758), pages 217-234, 2024-05
  DOI: 10.1007/978-1-0716-3989-4_14
• Kevin Rupp*, Rudolf Schill*, Jonas Süskind, Peter Georg, Maren Klever, Andreas Lösch, Lars Grasedyck, Tilo Wettig, and Rainer Spang*
  Differentiated uniformization: a new method for inferring Markov chains on combinatorial state spaces including stochastic epidemic models
  In: Computational Statistics, Volume 39, pages 3643–3663, 2024-01
  DOI: 10.1007/s00180-024-01454-9
• Rudolf Schill*, Maren Klever*, Kevin Rupp, Y. Linda Hu, Andreas Lösch, Peter Georg, Simon Pfahler, Stefan Vocht, Stefan Hansch, Tilo Wettig, Lars Grasedyck, and Rainer Spang*
  Reconstructing Disease Histories in Huge Discrete State Spaces
  In: KI - Künstliche Intelligenz, 2024-01
  DOI: 10.1007/s13218-023-00822-9
• Peter Georg, Lars Grasedyck, Maren Klever*, Rudolf Schill, Rainer Spang, and Tilo Wettig
  Low-rank tensor methods for Markov chains with applications to tumor progression models
  In: Journal of Mathematical Biology , Vol. 86, No. 1, 2022-12
  DOI: 10.1007/s00285-022-01846-9
• Lars Grasedyck, Maren Klever, Christian Löbbert, and Tim A. Werthmann*
  A parameter-dependent smoother for the multigrid method
  Forthcoming in: Computing and Visualization in Science, 2019-08
  DOI: 10.48550/arXiv.2008.00927

Conferences and Workshops

• METT X - 10th Workshop on Matrix Equations and Tensor Techniques
  Talk: Alternating non-negative factorization for low-rank tensor formats, Aachen, 2023-09
• ICIAM - 2023 International Congress on Industrial and Applied Mathematics
  Talk: Alternating non-negative factorization for low-rank tensor formats, Tokyo, 2023-08
• GAMM Annual Meeting 2022
  Talk: Low-rank tensor methods for Markov chains with applications to tumor progression models, Aachen, 2022-08
• METT IX - 9th Workshop on Matrix Equations and Tensor Techniques
  Talk: Low-rank tensor uniformization for tumor progression modeling, Perugia and hybrid, 2021-09
• METT VIII - 8th Workshop on Matrix Equations and Tensor Techniques
  As participant, Margdeburg, 2019-11

Teaching

WS 2020/2021 - 2024/2025	Assistant for Mathematics I (for Civil Engineers a.o.) Development and organization of e-learning tasks, exercises, and exams via Dynexite
SS 2021 - 2024	Assistant for Mathematics II (for Civil Engineers a.o.) Development and organization of e-learning tasks, exercises, and exams via Dynexite
WS 2019/2020	Supervision for the Seminar on Numerical Analysis
	Assistant for Mathematics I (for Civil Engineers a.o.) Conducting practice sessions for students
During studies SS 2016 - SS 2019	Student assistant for Numerical mathematics (for mechanical and electrical engineers) Numerical computation (for computer scientists) ODEs (for mathematicians) Independent supervision of small group exercises for students Student research assistant (building on my bachelor thesis)

Education

• Master of Science in Mathematics at the RWTH Aachen University
  Thesis: Low-Rank Tensor Solvers for Mutual Hazard Networks
  Supervisor: Prof. Dr. Lars Grasedyck
• Bachelor of Science in Mathematics at the RWTH Aachen University
  Thesis: Fundamental Solutions for a certain Class of Partial Differential Equations
  Supervisor: Prof. Dr. Manuel Torrilhon