Institute annual report 2025

last updates: February 3, 2026.

Human resources

Researchers

The Numerical Analysis and Approximation Theory workgroup:

• Dr. Emil Cătinaş
• Prof. Dr. Octavian Agratini (workgroup coordinator)
• Dr. Mihai Nechita
• Dr. Diana Otrocol
• Imre Boros
• Andra Malina
• Eduard Grigoriciuc

The Numerical Modeling workgroup:

• Prof. Dr. Radu Precup, corresponding member of the Romanian Academy
• Dr. Călin-Ioan Gheorghiu (workgroup coordinator)
• Dr. rer. nat. habil. Nicolae Suciu
• Dr. Maria Crăciun
• Andrei Stan
• Andrei Gasparovici (till June, 2025)
• Rareș Răhăian (since October 2025)

Doctoral students/postdocs:

Doctoral students in 2025:

• Eduard Grigoriciuc, Modern Approaches in the Theory of Univalent Mappings in C and Cⁿ, at UBB Cluj
• Andra Malina, Metode de aproximare a functiilor de mai multe variabile, at UBB Cluj
• Andrei Stan, Nash type equilibria for systems of nonlinear equations, at UBB Cluj.
• Andrei Gasparovici, (title to be completed), at UBB Cluj (hired since August 2024)

Postdoc students in 2025: –

PhD advisors

Prof. dr. Radu Precup, corresponding member of the Romanian Academy
PhD students (2025):

• Alexandru Hofman, Control problems for systems of Kolmogorov type, at UBB Cluj
• David Brumar, The analysis of some mathematical models in fluid dynamics, at UBB Cluj.
• … (to be completed)

Coordination of doc and postdoc students: Nataliia Kolun (Ukraine).
Mentor in some research projects: Lorand Parajdi, Mihai Nechita, Maria Neuss-Radu.

Prof. Univ. dr. Octavian Agratini
(no PhD students in 2025)

Dr. rer. nat. habil. Nicolae Suciu
(no PhD students in 2025)

Papers published in 2025

Papers in JCR journals from abroad

1. E. Burman, M. Nechita, L. Oksanen, Optimal approximation of unique continuation, Found. Comput. Math. 25, 1025–1045 (2025), https://doi.org/10.1007/s10208-024-09655-w.
2. T. Catinas, A. Malina, Spherical Shepard-Bernoulli operator, J. Appl. Math. Comput., 71 (2025), pp. 1267–1283, https://doi.org/10.1007/s12190-024-02285-z
3. N. Suciu, S. Nepal, Y. Wondmagegne, M. Ögren, A. Muntean, Global random walk for one-dimensional one-phase Stefan-type moving-boundary problems: Simulation results, Comp. Appl. Math., 44 (2025), art. no. 377. https://doi.org/10.1007/s40314-025-03334-4
4. S. Koumla, R. Precup, N. Ngarasta, Existence results for some functional integrodifferential equations with state-dependent delay, Differ. Eq. Dyn. Syst., 33 (2025), pp. 875–889. https://doi.org/10.1007/s12591-023-00661-y
5. Precup, A. Stan, Wei-Shih Du, Control of semilinear differential equations with moving singularities, Fractal and Fractional, 9 (2025), 198, 1-14, https://doi.org/10.3390/fractalfract9040198
6. Al. Hofman, R. Precup, A fixed-point approach to control problems for Kolmogorov type second-order equations and systems, Journal of Fixed Point Theory and Applications, 27 (2025), art. no. 7, https://doi.org/10.1007/s11784-024-01160-5
7. R. Precup, A. Stan, Fixed point results and the Ekeland variational principle in vector B-metric spaces, Axioms, 14 (2025), 250, 1-19, https://doi.org/10.3390/axioms14040250
8. U. Abel, O. Agratini, R. Păltănea, Szász–Mirakjan–Durrmeyer operators defined by multiple Appell polynomials, Positivity, 29 (2025), art. no. 17, https://doi.org/10.1007/s11117-024-01108-6
9. O. Agratini, M. Crăciun, Linear approximation processes based on binomial polynomials, Mathematics, 13 (15), 2025, https://doi.org/10.3390/math13152413.
10. A. Pop, M. Craciun, Two complementary approaches of the periodicity detection in astronomical time series, Experimental Astronomy, 59 (2025) art. no. 24, https://doi.org/10.1007/s10686-025-09995-7
11. C.I. Gheorghiu, Accurate Chebfun solutions to third-order nonlinear BVPs on the half-line. Applications in boundary layer theory, Physica Scripta, 100 (2025) no. 5, art. no. 055204, https://doi.org/10.1088/1402-4896/adc51a 
12. A. Stan, Role of partial functionals in the study of variational systems, Topological Methods in Nonlinear Analysis, 65 (2025) no. 1, pp. 383 – 399. https://doi.org/10.12775/TMNA.2024.033
13.  A. Stan, Symmetric Water Waves with Surface Tension: Traveling Wave Behavior and Maximal Horizontal Velocity. Water Waves 7, 593–603 (2025).
14.  A. Stan, Free-surface equatorial flows with surface tension in spherical coordinates. Applicable Analysis, 1–11 (2025).

Papers in JCR journals from Romania

1. V. Ilea, A. Novac, D. Otrocol, Fixed point results for weakly Picard non-self operators on ℝ+m-metric spaces, Fixed Point Theory 26 (2) 2025, pp.553-562,https://doi.org/10.24193/fpt-ro.2025.2.13 
2. D. Otrocol, V. Ilea, A. Novac, Fixed point results for non-self operators R₊m-metric spaces, Fixed Point Theory, 26 (2025) no. 1, 177-188, https://doi.org/10.24193/fpt-ro.2025.1.10

Chapters in books in recognized publishing houses/proceedings

1. N. Suciu, F.A. Radu, J.S. Stokke, E. Cătinaș, A. Malina, Computational orders of convergence of iterative methods for Richards’ equation, in: Sequeira, A., Silvestre, A., Valtchev, S.S., Janela, J. (eds) Numerical Mathematics and Advanced Applications ENUMATH 2023, vol. 2. ENUMATH 2023. Lecture Notes in Computational Science and Engineering, vol. 154 (2025), pp. 379–388. Springer, Cham. https://doi.org/10.1007/978-3-031-86169-7_39
2. A. Malina, An application of the Shepard operator in image reconstruction, 2024 26th International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (SYNASC), Timisoara, Romania, 2024, pp. 61-67, doi: http://doi.org/10.1109/SYNASC65383.2024.00023, Date Added to IEEE Xplore: 26 February 2025

Papers published in journals from other databases

1. R. Bunoiu, R. Precup, Localization and multiplicity for stationary Stokes systems with variable viscosity, Communications in Mathematical Analysis and Applications, 4 (2025) no. 2, pp. 151–178. https://doi.org/10.4208/cmaa.2025-0001
2. C.I. Gheorghiu, Chebyshev collocation solutions to some nonlinear and singular third-order problems relevant to thin-film flows, Journals Modern Mathematical Physics, 1 (2025) no. 1, art. no. 5, 15 pp., https://doi.org/10.3390/mmphys1010005

Papers accepted and published online

• E.Ş. Grigoriciuc, g-Loewner chains and the Graham–Kohr extension operator in complex Banach spaces, Comput. Methods Funct. Theory, (2025), https://doi.org/10.1007/s40315-025-00581-8

Preprints in Arxiv/submitted/accepted

• 1. U. Abel, O. Agratini, R. Păltănea, A complete asymptotic expansion for the semi-exponential Post-Widder operators, https://arxiv.org/abs/2509.12270
  2. R. Precup, A. Stan, On equilibrium in control problems with applications to evolution systems, arXiv:2409.09805, 2024.
  3. A. Stan Localization of critical points in annular conical sets via the method of Nehari manifold, Preprint, 2025. https://doi.org/10.48550/arXiv.2503.12371
  4. A. Stan, Two abstract methods of lower and upper solutions with applications (Preprint), 2025
  5. R. Precup, A. Stan, A Nehari manifold method for nonvariational problems (Preprint), 2025.
  6. R. Precup, A. Stan, Hybrid Nehari-Schauder type fixed point results and applications (Preprint), 2025.

Prizes, outstanding achievements

• Prof. Dr. R. Precup has H-index ISI 16: https://www.webofscience.com/wos/author/rid/B-8158-2011 (h-index Google Scholar 23)
• Dr. rer. nat. habil. N. Suciu has H-index ISI 13: https://www.webofscience.com/wos/author/rid/N-7971-2017 (h-index Google Scholar 14)
• Prof. Dr. O. Agratini has H-index ISI 10: https://www.webofscience.com/wos/author/rid/B-6607-2012 (h-index Google Scholar 20)

Since 2022, O. Agratini is professor emeritus at the Faculty of Mathematics and Computer Science (Babeş-Bolyai University).

Editorial activity

Editors-in-Chief/deputy/senior editors of JCR/ISI or Scopus journals

• R. Precup, Editor-in-Chief of Studia UBB Math. (ISI/ESCI)
• R. Precup, Deputy Editor-in-Chief of Fixed Point Theory (Cluj) (ISI)
• O. Agratini, Editor-in-Chief of J. Numer. Anal. Approx. Theory (Scopus)
• E. Cătinaş, Editor-in-Chief of J. Numer. Anal. Approx. Theory (Scopus)
• O. Agratini, senior Editor of Studia UBB Math. (ISI/ESCI)

Members of editorial boards of JCR/ISI journals

– JCR/ISI journals abroad

• R. Precup, section Editor of Fixed Point Theory and Algorithms for Sciences and Engineering (Springer);
• R. Precup, editor of Journal of Inequalities and Special Functions.

– JCR/ISI journals from Romania

• R. Precup, member of the Editorial Board of Proceedings of the Romanian Academy- Series A
• R. Precup, member of the Editorial Board of Carpathian Journal of Mathematics
• R. Precup, Deputy Editor-in-Chief of Fixed Point Theory (Cluj)
• R. Precup, Editor-in-Chief of Studia UBB Math.
• O. Agratini, senior Editor of Studia UBB Math.
• O. Agratini, member of the Editorial Board of J. Science and Arts.
• M. Nechita, secretary of Studia UBB Math.

Members of editorial boards of journals of the Romanian Academy

• O. Agratini, Editor-in-Chief of J. Numer. Anal. Approx. Theory
• E. Cătinaş, Editor-in-Chief of J. Numer. Anal. Approx. Theory
• M. Nechita, secretary of J. Numer. Anal. Approx. Theory
• A. Malina, secretary of J. Numer. Anal. Approx. Theory
• A. Stan, secretary of J. Numer. Anal. Approx. Theory
• R. Precup, member of the Editorial Board of Mathematica (Cluj)
• O. Agratini, member of the Editorial Board of Mathematica (Cluj)

Members of editorial boards of other journals from abroad

• R. Precup, member of the Editorial Board of Discussiones Mathematicae Differential Inclusions, Control and Optimization (Poland);
• O. Agratini, member of the Editorial Board of Open Journal of Discrete Mathematics;
• R. Precup, member of the Editorial Board of Mathematics in Engineering, Science and Aerospace (USA).

Members of editorial boards of other journals from Romania

• R. Precup, member of the Editorial Board of Transylvanian Journal of Mathematics and Mechanics;
• N. Suciu, member of the Editorial Board of ROMAI Journal
• C.I. Gheorghiu, member of the Editorial Board of ROMAI Journal

Conferences

Conferences organized by the Institute

• The international conference Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), organized by ICTP in 3-6 November 2025.

Invited speakers:

• R. Precup, Kirchhoff-type parabolic equations with nonlocal in space and time diffusion coefficients, Recent Trends in Nonlinear Differential Problems and Applications, Perugia, 4–6 June 2025;
• R. Precup, Fixed point approaches to control problems, International Workshop on Nonlinear Analysis and its Applications, Ankara, 3–5 September 2025;
• R. Precup, Navier-Stokes type models with control conditions given by inclusions, 5th Workshop on Geometric Function Theory in Several Complex Variables and Convex Banach Spaces. Cluj-Napoca, 28-30 November, 2025.

Talks given/conferences attended by the members of the Institute

International conferences

• O. Agratini, M. Crăciun, Generalizations of approximation processes based on squared binomial polynomial bases functions,  Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania

• M. Crăciun, T. Harko, General relativistic effects in Bose-Einstein Condensate dark matter halos, and their observational testing via the galactic rotation curves, 8th International Conference in Astronomy, Astrophysics, Space and Planetary Sciences, 2-4 July 2025, https://airaplanning.wixsite.com/zac2025

• Al. Pop, M. Crăciun, On the importance of estimation of statistical significance of spectral features in amplitude spectra of astronomical time series, 8th International Conference in Astronomy, Astrophysics, Space and Planetary Sciences, 2-4 July 2025, https://airaplanning.wixsite.com/zac2025

• E. Cătinaș, Computing functions of matrices, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• C.I. Gheorghiu, Complex singularities of an initial-boundary value problem modelling viscous film flow, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• E. Grigoriciuc, A Stancu-Schurer type extension of higher order of the Cheney-Sharma operators, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• A. Malina, T. Cătinaș, Methods for interpolating scattered data, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• M. Nechita, From conditional stability to optimal approximation for ill-posed elliptic PDEs, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• D. Otrocol, Best Ulam constant of a partial differential operator, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• R. Precup, Hybrid vector fixed point theorems, First Balkan Workshop on Fixed Point Theory and Applications, Cluj-Napoca, 12–13 June 2025;
• R. Precup, Navier-Stokes type models with control conditions given by inclusions, International Conference on Analysis – The 16th Romanian-Finnish Seminar, Alba Iulia, 24–27 June 2025;
• R. Răhăian, On Tikhonov regularization for the elliptic Cauchy problem, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania
• A. Stan, Localization of critical points in conical sets via the method of Nehari manifolds, Recent Trends in Nonlinear Differential Problems and Applications, Perugia, 4–6 June 2025;
• A. Stan, Fixed point results and the Ekeland variational principle in
  vector B-metric spaces, First Balkan Workshop on Fixed Point Theory and Applications, Cluj-Napoca, 12–13 June 2025;
• A. Stan, R. Precup, Nash equilibria of fractional functionals via a Dinkelbach–Ekeland type approach, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania.
• N. Suciu, Three-dimensional explicit L scheme for Richards equation, Numerical Analysis, Numerical Modeling, Approximation Theory (NANMAT 2025), 3-6 November 2025, Cluj-Napoca, Romania

Presentations at seminars

• Eduard Ștefan Grigoriciuc (ICTP), PhD Thesis: Modern approaches in the theory of univalent mappings in C and Cⁿ, 04.06.2025
• Eduard Ștefan Grigoriciuc (ICTP), A short story about parallel computing in Julia, 09.04.2025
• Andra Malina (ICTP), Parallel computing in Julia, 26.03.2025
• Andra Malina (ICTP), Ph.D. Thesis: Methods for approximating multivariate functions, 28.05.2025
• Mihai Nechita (ICTP), Calcul paralel în Matlab cu exemple numerice pentru plăci grafice (GPU), 14.05.2025
• R. Precup, Navier-Stokes type models with control conditions given by inclusions, Seminarul Operatori Neliniari şi Ecuaţii Diferenţiale, UBB, 27 February 2025.
• R. Precup, Navier-Stokes type models with control conditions given by inclusions, Seminarul Operatori Neliniari şi Ecuaţii Diferenţiale, UBB, 20 November 2025.
• Rareș Răhăian (ICTP), Regularisation methods for inverse problems related to partial differential equations, 01.10.2025
• A. Stan, Fixed-Point Results and the Ekeland Variational Principle in Vector B-Metric Spaces, Seminarul Operatori Neliniari şi Ecuaţii Diferenţiale, UBB, 3 April 2025.
• A. Stan, Symmetric water waves with surface tension: traveling wave behavior and maximal horizontal velocity, Seminarul Operatori Neliniari şi Ecuaţii Diferenţiale, UBB, 15 May 2025.
• A. Stan, Localization of critical points in annular conical sets via the method of Nehari manifold, Seminarul Operatori Neliniari şi Ecuaţii Diferenţiale, UBB, 13 November 2025.
• Andrei Stan (ICTP), The Nehari manifold method in a nutshell, 26.11.2025
• Nicolae Suciu (ICTP), Chebfun, geometric accuracy, and convergence, 10.12.2025

Scientific collaborations

ICTP has signed in July 2023 a collaboration protocol with Data and Predictive Analytics Center (DPAC – Rochester University, USA), based on some existing collaborations. The agreement aims in solving some problems in the analysis, processing and modelling of some time series from astronomy.

International scientific collaborations

• N. Suciu, collaboration with F.A. Radu, from Univ. of Bergen, Norway
• N. Suciu, collaboration with A. Muntean, from Karlstad University, Sweden
• N. Suciu, collaboration with I.S. Pop, from Univ. of Hasselt, Belgium
• E. Cătinaş, collaboration with F.A. Radu, from Univ. of Bergen, Norway
• R. Precup, collaboration with Jorge Rodriguez-Lopez, from Univ. of Santiago de Compostela, Spain
• R. Precup, collaboration with Sylvain Koumla, from Univ. Abéché, Chad;
• R. Precup, collaboration with Christian Guenther, from Univ. Hannover, Germany;
• R. Precup, collaboration with Maria Neuss-Radu, ffrom FAU Erlangen-Nürnberg, Germany;
• R. Precup, collaboration with Renata Bunoiu, from Univ. Lorraine, France;
• M. Nechita, collaboration with Erik Burman, from University College London;
• M. Nechita, collaboration with Lauri Oksanen, from University of Helsinki;
• M. Nechita, collaboration with Miguel A. Fernández, from INRIA Paris;
• M. Nechita, collaboration with Muriel Boulakia, from Université de Versailles;
• M. Nechita, collaboration with Maria Neuss-Radu, from FAU Erlangen-Nürnberg, Germany;
  
• O. Agratini, collaboration with Ulrich Abel, from Technische Hochschule Mittelhessen, Friedberg, Germany;
• O. Agratini, collaboration with Harun Karsli, from Abant Izzet Baysal University, Bolu, Turkey;
• O. Agratini, collaboration with Francesco Altomare, from University of Bari Aldo Moro, Italy;
• O. Agratini, collaboration with Ralf Rigger, from Friedberg, Germany;
• O. Agratini, collaboration with Tanmoy Som, from Indian Institute of Technology (BHU) Varanasi;
• O. Agratini, collaboration with Quy Muoi Oham;
• M. Craciun, collaboration with Mihai Barbosu, Rochester Institute of Technology, New York, USA;
• A. Stan, collaboration with Du Wei-Shih, National Kaohsiung Normal University, Taiwan;
• A. Stan, collaboration with Calin Iulian Martin, University of Vienna.
• A. Stan, collaboration with Jorge Rodriguez-Lopez, University of Santiago.

National scientific collaborations

• O. Agratini, collaboration with Mircea Ivan, Technical University Cluj-Napoca;
• O. Agratini, collaboration with Radu Păltănea, Transilvania University of Brașov;
• M. Craciun, collaboration with Tiberiu Harko, from Babes-Bolyai University, Cluj-Napoca;
• M. Craciun, collaboration with Alexandru Pop, Astronomical Institute, Astronomical Observatory Cluj-Napoca, Romanian Academy;
• A. Malina, collaboration with Teodora Catinas, from Babes-Bolyai University, Cluj-Napoca;
• E. Grigoriciuc, collaboration with Mirela Kohr, from Babes-Bolyai University, Cluj-Napoca;
• R. Precup, collaboration with Petru Jebelean, from West University, Timisoara;
• R. Precup, collaboration with Mirela Kohr, from Babes-Bolyai University, Cluj-Napoca
• R. Precup, collaboration with Nataliia Kolun, from Babes-Bolyai University, Cluj-Napoca;
• R. Precup, collaboration with Lorand Parajdi, from Babes-Bolyai University, Cluj-Napoca;
• R. Precup, collaboration with Veronica Ilea, from Babes-Bolyai University, Cluj-Napoca;
• R. Precup, collaboration with Adela Novac, from Technical University Cluj-Napoca;
• R. Precup, collaboration with Stefan Haplea, from Iuliu Hațieganu University of Medicine and Pharmacy Cluj-Napoca;
• A. Stan, collaboration with Cristina Gheorghe from Babes-Bolyai University, Cluj-Napoca.

Membership in professional organizations

• R. Precup, O. Agratini, D. Otrocol: SSMR (Societatea de Științe Matematice din România) members.
• E. Cătinaş, SIAM (Society for Industrial and Applied Mathematics) member  (since 2007), SSMR (Societatea de Științe Matematice din România).
• E. Grigoriciuc: SSMR (Romanian Mathematical Society) member (since 2020), AMS (American Mathematical Society) member (since 2021), LMS (London Mathematical Society) member (since 2021), EMS (European Mathematical Society) member (since 2021), SIAM (Society for Industrial and Applied Mathematics) member (since 2024).
• C.I. Gheorghiu, ROMAI (Societatea Română de Matematică Aplicată și Industrială), GAMM (Gesellschaft für angewandte Mathematik und Mechanik), ECMI (European Consortium for Mathematics in Industry) member.
• O. Agratini: AMS (American Mathematical Society) member.
• M. Crăciun, SIAM (Society for Industrial and Applied Mathematics) member.
• M. Nechita, SIAM (Society for Industrial and Applied Mathematics) member.
• A. Malina, SIAM (Society for Industrial and Applied Mathematics), AMS (American Mathematical Society) member.

Grants/contracts/scholarships

• grant for financing the technical-scientific literature, 48.000 lei.

Peer review

Members of PhD/habilitation evaluation committees

• R. Precup: Comisia de concurs post de profesor la UTCN (candidat Todea Constantin), Comisia de abilitare la UBB (conf. Madalina Pacurar)

Members of PhD supervising committees

• R. Precup, Comisia UBB de analiza a tezelor de doctorat sustinute in perioada 1990-2016: 6 teze

Referee reports for peer reviewed journals:

• R. Precup: Studia (9 reviews; 1907, 1928, 7031, 7032, 7406, 7270, 2091, 2047, 1948), Mathematica (2 reviews; 2175, 2214),  Fixed Point Theory (1 review ; 25-0003), Journal of Fixed Point Theory and Applications (1 review), Taiwanese Journal of Mathematics (1 review), Carpathian Journal of Mathematics (1 review), Applied Mathematical Letters (1 review),  Numerical Functional Analysis and Optimization (1 review).
• M. Nechita: SIAM Journal on Numerical Analysis (1), Computers & Mathematics with Applications (1), Studia UBB Math (5), Journal of Numerical Analysis and Approximation Theory (10).

Book reviews:

• A. Stan: 1 book review.
• E. Grigoriciuc: 1 book review.

Reviews (written in 2025)

for Mathematical Reviews:

• O. Agratini:
• R. Precup: 4844484, 4730414
• A. Malina: MR4876609, MR4940300
• C. Mustăța (honorary member): 

For ZBL Math:

• R. Precup: 8066271
• C.I. Gheorghiu: