Andreas Grigorjew

About me

I am a doctoral student at the University of Helsinki in the Department of Computer Science, supervised by Alexandru I. Tomescu. I am part of the Graph Algorithms Team.

My research interests broadly lie in theoretical computer science and include combinatorics, graph theory and algorithms. I also study the design of algorithms for computational problems that arise from Biology.
During my doctoral studies I was very fortunate to spend one week at the Max Planck Institute for Biology, Tübingen for research collaboration with Hajk-Georg Drost, three weeks at the University of Verona for collaboration with Romeo Rizzi and two months at the Montana State University for collaboration with Brendan Mumey.
I am always interested in working on interesting problems together, you are welcome to get in touch!

In my free time, I enjoy strolling around, hiking or bouldering. I am also trying to master playing the violin and the Finnish language.

Contact

Postal address: Department of Computer Science, P.O. Box 68, FI-00014 University of Helsinki, Finland
Physical address: Pietari Kalmin katu 5, 00560 Helsinki, Finland
Email: contact [at] andreasgrigorjew [dot] de (PGP key)
Social media: @andreasg@mathstodon.xyz (Mastodon), andreasgrigorjew (GitHub)

Research

Publications and preprints

Note that authors in publications in theoretical computer science are usually ordered alphabetically, while authors in publications in Bioinformatics are ordered by contribution.

• Andreas Grigorjew, Fernando H. C. Dias, Andrea Cracco, Romeo Rizzi, Alexandru I. Tomescu
  Accelerating ILP solvers for Minimum Flow Decompositions through search space and dimensionality reductions
  arXiv preprint, 2023 (view)
  Accepted for SEA 2024!
• Manuel Cáceres, Massimo Cairo, Andreas Grigorjew, Shahbaz Khan, Brendan Mumey, Romeo Rizzi, Alexandru I. Tomescu, Lucia Williams
  Width Helps and Hinders Splitting Flows
  ESA 2022 - European Symposium on Algorithms (Track A), 31:1--31:14, 2022 (view)
  ACM Transactions on Algorithms, 20(2), 1--20, 2024 (view extended version)
• Andreas Grigorjew, Artur Gynter, Fernando Dias, Benjamin Buchfink, Hajk-Georg Drost*, Alexandru I. Tomescu*
  Sensitive inference of alignment-safe intervals from biodiverse protein sequence clusters using EMERALD
  Genome Biology 24, 168, 2023 (view)
  *Equal contribution

Software

• Optimized FD: An optimized flow decomposition solver using Integer Linear Programming, for exact optimum and heuristic solutions (GitHub).
  Flow decompositions are used e.g. for RNA transcriptict assembly or viral strain reconstruction.
• EMERALD: a protein sequence aligner that finds safety windows, protein regions preserved in the suboptimal alignment space (GitHub).

Teaching

I was a teaching assistant in the following courses holding exercise classes:

• Models of Computation, spring 2024 (Helsinki, ongoing)
• Models of Computation, spring 2023 (Helsinki)
• Elements of Bioinformatics, autumn 2022 (Helsinki)
• Design and analysis of algorithms, autumn 2021 (Helsinki)
• Mathematik für Data Science und Physik Studierende I, winter 2021 (Erlangen)
• Analysis III, winter 2019 (Erlangen)
• Theorie der Programmierung, summer 2019 (Erlangen)
• Theorie der Programmierung, summer 2018 (Erlangen)

Education

• since April 2021: Doctoral student in the Department of Computer Science at the University of Helsinki
• October 2018 until March 2021: Master of Science in Mathematics at the Friedrich-Alexander-Universität Erlangen-Nürnberg
• January 2020 until May 2020: Exchange semester at the University of Helsinki
• October 2015 until July 2018: Bachelor of Science in Mathematics at the Friedrich-Alexander-Universität Erlangen-Nürnberg