School of Computer Science and Mathematics,
Liverpool John Moores University

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*** Personal Info *** Publications *** Teaching *** Contact ***

Senior Lecturer, 09/2021-
 School of Computer Science and Mathematics, Liverpool John Moores University, UK.

University Teacher, 10/2020-09/21
 Department of Computer Science, University of Liverpool, UK.

Research Associate, 03/2019-09/2020
 Department of Computer Science, University of Oxford, UK.
 In ERC project "Analysis, Verification, and Synthesis of Infinite-State Systems" led by Prof. Joël Ouaknine.

Lecturer, 10/2019-09/2020
 Jesus College, University of Oxford, UK.

Research Associate, 06/2018-02/2019
 Department of Computer Science, University of Oxford, UK.
 In ERC project "Algorithmic Verification of String Manipulating Programs" led by Prof. Anthony W. Lin.

Research Associate, 01/2018-05/2018
 Department of Computer Science, University of Liverpool, UK.
 In EPSRC project "Reachability problems for words, matrices and maps" led by Prof. Igor Potapov.

Project Reseacher, 10/2013-09/2014
 Dept of Mathematics and Statistics, University of Turku, Finland

SET for BRITAIN 2016, finalist in a poster competition in the House of Commons

Nokia Foundation's Nokia Scholarship 2014

Postgraduate Research Studentship, Dept of Computer Science, University of Liverpool, 10/2014-09/2017

PhD in Computer Science, 10/2014-07/2018
 Title of PhD Thesis: Reachability games and related matrix and word problems
 Supervisors: Prof. Igor Potapov, Dr Vesa Halava, and Prof. Paul Spirakis
 Department of Computer Science, University of Liverpool, UK.

M.Sc. in Mathematics, 02/2013-08/2013
 Thesis: “On Decidability of the Mortality Problem for Small Integer Matrices” (in Finnish)
 Dept of Mathematics and Statistics,
 University of Turku, Finland

B.Sc. in Mathematics, 09/2007-02/2013
 Dept of Mathematics and Statistics,
 University of Turku, Finland

On the Identity and Group Problems for Complex Heisenberg Matrices,
Paul C. Bell, R.N., Igor Potapov, Pavel Semukhin, in proc. of RP 2023, LNCS 14235: 42-55, 2023.

Integer weighted automata on infinite words,
Vesa Halava, Tero Harju, R.N., Igor Potapov International Journal of Foundations of Computer Science, 2022.

Reachability problems in low-dimensional nondeterministic polynomial maps over integers,
Sang-Ki Ko, R.N., Igor Potapov, in Information and Computation 281: 104785, 2021.

Integer weighted automata on infinite words,
Vesa Halava, Tero Harju, R.N., Igor Potapov in proc. of DLT 2021, LNCS 12811: 167-179, 2021.

On decidability and complexity of low-dimensional robot games,
R.N., Igor Potapov, Julien Reichert, in Journal of Computer and System Sciences 107: 124-141, 2020.

Monadic Decomposability of Regular Relations,
Pablo Barceló, Chih-Duo Hong, Xuan-Bach Le, Anthony W. Lin, R.N., in proc. of ICALP 2019, LIPIcs 132: 103:1-103:14, 2019.

Reachability Problems in Nondeterministic Polynomial Maps on the Integers,
Sang-Ki Ko, R.N., Igor Potapov, in proc. of DLT 2018, LNCS 11088: 465-477, 2018.

On the Identity Problem for the Special Linear Group and the Heisenberg Group,
Sang-Ki Ko, R.N., Igor Potapov in proc. of ICALP 2018, LIPIcs 107 132:1-132:15, 2018.

Reachability problem for polynomial iteration is PSPACE-complete,
R.N. in proc. of RP 2017, LNCS 10506: 132-143, 2017.

Small Semi-Thue System Universal with Respect to the Termination Problem,
Vesa Halava, Yuri Matiyasevich, R.N., in Fundamenta Informaticae 154(1-4): 177-184, 2017.

Weighted Automata on Infinite Words in the Context of Attacker-Defender Games,
Tero Harju, Vesa Halava, R.N., Igor Potapov, in Information and Computation 255: 27-44, 2017.

Robot Games with States in Dimension One,
R.N. in proc. of RP 2016, LNCS 9899: 163-176, 2016.

Undecidability of Two-dimensional Robot Games,
R.N., Igor Potapov, Julien Reichert in proc. of MFCS 2016, LIPIcs 58: 73:1-73:13, 2016.

On Robot Games of Degree Two,
Vesa Halava, R.N., Igor Potapov in proc. of LATA 2015, LNCS 8977: 224-236, 2015.

Weighted Automata on Infinite Words in the Context of Attacker-Defender Games,
Tero Harju, Vesa Halava, R.N., Igor Potapov, in proc. of CiE 2015, LNCS 9136: 206-215, 2015.

Undecidability of the Universality Problem for 3-State Integer Weighted Büchi Automata,
Vesa Halava, Tero Harju, R.N., Igor Potapov, pre-print, 2014.

Reviewer for journals Constraints, FI, IJFCS, IPL, JCSS.
Subreviewer for conferences CiE 2022, CPM 2015, DLT 2014, 2015, 2016, 2018, 2020, FCT 2019, 2021, ICALP 2023, LATIN 2018, LICS 2020, MFCS 2019, RP 2019, STACS 2019, 2021, 2023, SOFSEM 2018, 2020, VMCAI 2019.

Association Computability in Europe
European Association for Theoretical Computer Science

19th International Conference on Developments in Language Theory (Liverpool, UK),
9th International Conference on WORDS (Turku, Finland),
Salomaa 80 - conference dedicated to academician Arto Salomaa on his 80th birthday (Turku, Finland).

Level 5 Tutor for Computer Science, Liverpool John Moores University, 2023-present.
First Aider, Liverpool John Moores University, 2022-present.
Mental Health First Aid Champion at Department of Computer Science, University of Oxford, 2019-2020.
Member of the Staff-Student Liason Committee at Department of Computer Science, University of Liverpool, 2016-2017.