Institute annual report 2020
(version of December 22, 2020)
The Numerical Analysis and Approximation Theory workgroup:
- Dr. Emil Cătinaş (workgroup coordinator)
- Prof. Dr. Octavian Agratini
- Dr. Diana Otrocol
- Dr. Flavius Pătrulescu
- Dr. Mihai Nechita
- Imre Boros
- Dr. Cristian-Daniel Alecsa
The Numerical Modeling workgroup:
- Dr. Călin-Ioan Gheorghiu (workgroup coordinator)
- Dr. rer. nat. habil. Nicolae Suciu
- Dr. Maria Crăciun
- Dr. rer. nat. habil. Nicolae Suciu supervises PhD theses.
He has recently supervised the thesis Filtered density functions for uncertainty assessment of transport in groundwater, by Lennart Schüler, defended on September 8, 2016, at Jena University, Germany; the thesis received the distinction Magna Cum Laudae.
- Prof. dr. Ion Păvăloiu, honorary member, has supervised -in the past- 8 PhD theses at North University of Baia-Mare and at Babeş-Bolyai University.
- Prof. dr. Octavian Agratini, who supervises PhD theses at Babes-Bolyai University.
Papers published in 2020 in JCR/ISI indexed journals:
Papers in JCR journals from abroad
- C.D. Alecsa, I. Boros, F. Frank, P. Knabner, M. Nechita, A. Prechtel, A. Rupp, N. Suciu, Numerical benchmark study for flow in highly heterogeneous aquifers, Adv. Water Res., 138 (2020), 103558. Impact Factor (IF) 2019: 4.01
- C.D. Alecsa, T. Pinţa, I. Boros, New optimization algorithms for neural network training using operator splitting techniques, Neural Networks, 126 (2020), 178-190. doi: 10.1016/j.neunet.2020.03.018 IF 2019: 5.53
- E. Burman, M. Nechita, L. Oksanen, A stabilized finite element method for inverse problems subject to the convection-diffusion equation. I: diffusion-dominated regime, Numer. Math. 144 (2020), pp. 451-477 IF 2019: 2.05
- M. Crăciun, T. Harko, Testing Bose-Einstein condensate dark matter models with the SPARC galactic rotation curves data, The European Physical Journal C, 80 (2020) 8, 735, 1-28, IF 2019: 4.3
- C.-D. Alecsa, S.C. László, A. Viorel, A gradient-type algorithm with backward inertial steps associated to a nonconvex minimization problem, Numer. Algor. 84 (2020), pp. 485-512.
- F. Pătrulescu, T. Groşan, I. Pop, Natural convection from a vertical plate embedded in a non-Darcy bidisperse porous medium, ASME-Journal of Heat Transfer 142(1): 012504, HT-19-1097 (2020), (11 pages)
- V. Ilea, A. Novac, D. Otrocol, R. Precup, Solutions with a prescribed interval of positivity for differential systems with nonlocal conditions, Appl. Math. Comput., 375 (2020), doi: 10.1016/j.amc.2020.125092
- V. Ilea, D. Otrocol, Existence and uniqueness of the solution for an integral equation with supremum, via w-distances, Symmetry 2020, 12, 1554, https://doi.org/10.3390/sym12091554
- O. Agratini, Linear positive operators constructed by using Beta-type bases, Hacettepe Journal of Mathematics & Statistics, 49 (2020) no. 3, pp. 1030-1038, doi: 10.15672/hujms.549015
- C. I. Gheorghiu, Spectral collocation based on quasi-classical orthogonal polynomials applied to solve a singular BVP from hydrodynamics, AIP Conference Proceedings 2293, 100004 (2020); https://doi.org/10.1063/5.0026783
- A.M. Acu, A. Maduta, D. Otrocol, I. Raşa, Inequalities for information potentials and entropies, Mathematics 2020, 8(11), 2056; https://doi.org/10.3390/math8112056
Papers in JCR journals from Romania
- O. Agratini, Modifying an approximation process using non-Newtonian calculus, Stud. Univ. Babes-Bolyai Math. 65 (2020) no. 2, 291–301, doi: 10.24193/subbmath.2020.2.10
- V. Ilea, D. Otrocol, On the Burton method of progressive contractions for Volterra integral equations, Fixed Point Theory, 21 (2020) no. 2, 585-594.
Papers published in other journals
- T. Cătinaș, D. Otrocol, Iterates of Cheney-Sharma type operators on a triangle with curved side, J. Comp. Anal. Appl., 28 (2020) no. 4, pp. 737-744.
- O. Agratini, A stop over Jain operators and their generalizations, Annals of West University of Timisoara – Mathematics and Computer Science, 56 (2018) no. 2, pp. 28-42.
- M. Nechita, Sir George Jessel studentship, University College London (february 2020).
Papers accepted and published online in JCR/ISI journals [with coordinates to follow in 2021]
- C.D. Alecsa, S.C. László, T. Pinţa, An extension of the second order dynamical system that models Nesterov’s convex gradient method, Appl. Math. Optim. (2020). doi: 10.1007/s00245-020-09692-1
Preprints in Arxiv
- C. I. Gheorghiu, Accurate spectral collocation computation of high order eigenvalues for singular Schroedinger equations. arXiv/3486226[math-ph]
- C. I. Gheorghiu, Accurate spectral collocation solutions to some Bratu’s type Boundary Value Problems. arXiv/3486209[math.NA]
- C. I. Gheorghiu, Spectral collocation solutions to second order singular Sturm-Liouville eigenproblems, arXiv/ 3484569[math.NA]
- C.D. Alecsa, I. Boros, F. Frank, P. Knabner, M. Nechita, A. Prechtel, A. Rupp, N. Suciu, Benchmark for numerical solutions of flow in heterogeneous groundwater formations, arxiv 1911.10774.
- E. Burma, M. Nechita, L. Oksanen, A stabilized finite element method for inverse problems subject to the convection-diffusion equation. II: convection-dominated regime, 2020., arXiv:2006.13201
- N. Suciu, Global random walk solutions for flow in porous media, accepted paper, ENUMATH 2019 Proceedings, to apear (Springer)
Posts in notable repositories
- C. I. Gheorghiu, A third-order nonlinear BVP on the half-line, January 2020, https://www.chebfun.org/examples/ode-nonlin/GulfStream.html
Members of Editorial Boards
- Studia UBB Math.: O. Agratini (senior Editor)
- J. Numer. Anal. Approx. Theory: O. Agratini (Editor-in-Chief), E. Catinas (Editor-in-Chief), D. Otrocol, M. Nechita, I. Boros
- ROMAI Journal: N. Suciu, C.I. Gheorghiu
- Mathematica (Cluj): O. Agratini
- Open Journal of Discrete Mathematics: O. Agratini
- J. Science and Arts: O. Agratini
Conferences attended by the members of the Institute
- C.D. Alecsa, I. Boros, F. Frank, P. Knabner, M. Nechita, A. Prechtel, A. Rupp, N. Suciu, D443: Numerical benchmark study for flow in highly heterogeneous aquifers, EGU General Assembly 2020 – Sharing Geoscience Online, https://doi.org/10.5194/egusphere-egu2020-10504
- O. Agratini, Using the sequences of linear operators to approximate signals, The 2nd International Conference on Mathematics and Computers in Science and Engineering, MACISE 2020, Madrid, Spain, January 18-20, 2020. https://www.macise.org/#Plenary
- S.C. Laszlo, C.D. Alecsa, T. Pinta, An extension of the second order dynamical system that models Nesterov’s convex gradient method, Games, Dynamics and Optimization (GDO2020), Rome, Italy, February 24-26, 2020.
- International grant SU 415/4-1 (https://gepris.dfg.de/gepris/projekt/405338726) obtained by dr. rer. habil. N. Suciu from (Deutschefourschungs Gmemeindschaft), for the project “Integrated global random walk model for reactive transport in groundwater adapted to measurement spatio-temporal scales” (01.10.2018-30.09.2021), in progress at Erlangen-Nuernberg University.