# Institute annual report 2019

updates: Jan. 6, 2024; Dec. 3, 2022, Nov. 6, 2021, Mar. 15, 2022 (with CNCSIS prizes), June 28, 2023 (with Peer Review)

updates: Jan. 6, 2024; Dec. 3, 2022, Nov. 6, 2021, Mar. 15, 2022 (with CNCSIS prizes), June 28, 2023 (with Peer Review)

The Numerical Analysis and Approximation Theory workgroup:

- Dr. Emil
**Cătinaş**(workgroup coordinator) - Prof. Dr. Ion
**Păvăloiu**(from January to March 2019) - Prof. Dr. Octavian
**Agratini** - Dr. Mira-Cristiana
**Anisiu**(March 2009) - Dr. Diana
**Otrocol** - Dr. Flavius
**Pătrulescu** - Mihai
**Nechita** - Imre
**Boros** - Cristian-Daniel
**Alecsa**

The Numerical Modeling workgroup:

- Dr. Călin-Ioan
**Gheorghiu**(workgroup coordinator) - Dr. rer. nat. habil. Nicolae
**Suciu** - Dr. Maria
**Crăciun**

PhD students:

- Cristian-Daniel
**Alecsa**,*Contributions to the fixed point theory of single-valued and multi-valued operators defined on generalized metric spaces (**Contribuții la teoria punctului fix pentru operatori univoci și multivoci definiți pe spații metrice generalizate),*at UBB Cluj – supervisor: A. Petrusel - Imre
**Boros**,*Numerical methods for partial differential equations,*at UBB Cluj – supervisor: O. Agratini - Mihai
**Nechita**,*Unique continuation problems and stabilised finite element methods,*at University College London, supervisors: Erik Burman and Lauri Oksanen

Postdocs: -.

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** 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.

theses supervised 2019:

- Grapini O. Silviu-Ilie,
- Balogh M. Anamaria,
- Bunea-Domșa S. Mihai Grigore,
**Boros**Imre,*Numerical methods for partial differential equations*.

** Survey papers**

- E. Cătinaş,
*A survey on the high convergence orders and computational convergence orders of sequences*, Appl. Math. Comput., 343 (2019) 1-20. (2018 SRI 0.97, IF 3.092)

**.**

Papers - E. Burman,
__M. Nechita__, L. Oksanen,*Unique continuation for the Helmholtz equation using stabilized finite element methods*, J. Math. Pures Appl. 129 (2019), pp. 1-22. (SRI 3.7, IF 1.961)

(rem.: M. Nechita is a PhD student at UCL, London) - V. Moisoiu, A. Socaciu, A. Stefancu, S.D. Iancu,
__I. Boros, C. Alecsa__, C. Rachieriu, A.R. Chiorean, D. Eniu, N. Leopold, C. Socaciu, D. Eniu,*Breast cancer diagnosis by surface-enhanced Raman scattering (SERS) of urine*, Appl. Sci. (2019), 9(4), 806; (SRI 0.93, IF 2.217) - A. Aral,
__D. Otrocol__, I. Raşa,*On approximation by some Bernstein–Kantorovich exponential-type polynomials*, Period. Math. Hung. (2019) 79: 236. (SRI 0.51, IF 0.664) __D. Alecsa__,*Common fixed points for Presic operators via simulation functions*, J. Nonlin. Conv. Analysis, 20 (2019) no. 3, 363-377. (SRI 0.35, IF 0.595) ISSN 1345-4773__M. Crăciun__, T. Harko,*Constraining Bose-Einstein condensate dark matter models with the galaxy rotation curves of the SPARC sample*, Romanian Astronomical Journal, 29 (2019) no.2, 101-118.- V. Moisoiu, A. Stefancu, S. D. Iancu, T. Moisoiu, L. Loga, L. Dican, C. D. Alecsa, I. Boros, A. Jurj, D. Dima, C. Bagacean, R. Tetean, E. Burzo, C. Tomuleasa, F. Elec, N. Leopold,
*SERS assessment of the cancer-specific methylation pattern of genomic DNA: towards the detection of acute myeloid leukemia in patients undergoing hematopoietic stem cell transplantation*, Anal. Bioanal. Chem. 411 (2019) no. 29, pp. 7907–7913. (doi: 10.1007/s00216-019-02213-2) - D. Alecsa, Approximating fixed points for nonlinear generalized mappings using Ishikawa iteration, Rendiconti del Circolo Matematico di Palermo, Series 2,
**68**(2019), 163-191. - C.D. Alecsa,
*Sequences of contractions on cone metric spaces over Banach algebras and applications to nonlinear systems of equations and systems of differential equations*, International J. Nonlin. Anal. Appl., 10 (2019) 2, pp. 227-254, DOI: 10.22075/ijnaa.2019.18884.2040 - D. Otrocol,
*Qualitative properties of solutions for mixed type functional-differential equations with maxima*, Miskolc Mathematical Notes, 20 (2019) no. 2, pp. 1119-1128.

- C.I. Gheorghiu,
*Spectral collocation solutions to a class of pseudo-parabolic equations*, G. Nikolov et al. (Eds.): Numerical Methods and Applications. NMA 2018. Lecture Notes in Computer Science, vol 11189. Springer, Cham., pp. 1–8, 2019. doi: 10.1007/978-3-030-10692-8_20 __Agratini__,*Shift λ – invariant operators*, Constructive Mathematical Analysis, 2 (2019) 3, 103-108. DOI http://doi/org/10.33205/cma.544094__Agratini__,*From uniform to statistical convergence of binomial-type operators*, In: Advances In Summability And Approximation Theory, 169 – 179, (Eds. S. A. Mohiuddine, T. Acar), Springer, Singapore, 2018. ISBN: 978-981-13-3076-6, DOI https://doi.org/10.1007/978-981-13-3077-3_10- C.I. Gheorghiu, B. Zinsou,
*Analytic vs. numerical solutions to a Sturm-Liouville transmission eigenproblem*, J. Numer. Anal. Approx. Theory, 48 (2019) no. 2, 159-174. - C.D. Alecsa, A. Petruşel,
*Some variants of Ćirić’s multi-valued contraction principle,*Annals of West University of Timisoara – Mathematics and Computer Science,**57**(2019) no. 1, pp.23-42, https://doi.org/10.2478/awutm-2019-0004

__D. Alecsa, I. Boros, T. Pinta__,*New optimization algorithms for neural network training using operator splitting techniques*, Arxiv 1904.12952 (preprint)- Maduta,
__D. Otrocol__, I. Rasa,*Inequalities for indices of coincidence and entropies*, arXiv: 1910.1349 (preprint) - C.D. Alecsa S.C. Laszlo, T. Pinta,
*An extension of the second order dynamical system that models Nesterov’s convex gradient method and convergence rates of order O(1/n2) for the energy error in the sequences generated by the resulted inertial algorithms*, 2019, posted on ResearchGate - C.D. Alecsa S.C. Laszlo, A. Viorel,
*A gradient type algorithm with backward inertial steps associated to a nonconvex minimization*, 2019, posted on ResearchGate

- O. Pătrulescu, T. Groşan, I. Pop,
*Natural convection from a vertical plate embedded in a non-Darcy bidisperse porous medium*, ASME-Journal of Heat Transfer (2019), DOI: https://doi.org/10.1115/1.4045067. (ISSN: 0022-1481). IF: 1.479. (paper published in 2019, with coordinates in 2020) - C.-D. Alecsa, S.C. László, A. Viorel,
*A gradient-type algorithm with backward inertial steps associated to a nonconvex minimization problem*, Numer. Algor., https://doi.org/10.1007/s11075-019-00765-z - C.I. Gheorghiu,
*Spectral Collocation Based on Quasi-Classical Orthogonal Polynomials Applied to Solve a Singular BVP from Hydrodynamics*, AIP Publishing, (accepted, to appear)

- T. Cătinaş,
__D. Otrocol__,*Iterates of Cheney-Sharma type operators on a triangle with curved side*, J. Comput. Anal. Appl.

- C.D. Alecsa,
*Diploma Academiei Romane privind rezultate remarcabile cu privire la teoria si programarea metodelor numerice*, May 14 2019. (Romanian Academy Diploma for: remarkable results regarding theory and practice of numerical methods)

Dr. N. Suciu has achieved high Hirsch index.

CNCSIS prizes for papers published in the “red zone” journals (based on journals impact factor or influence score):

- E. Cătinaş, code: PRECISI-2019-35376
- O. Agratini, code: PRECISI-2019-35373

Symposium:* Numerical Analysis, Approximation and Modeling*, Cluj-Napoca, April 16, 2019.

**Note:** with the participation of Prof. C. Cartis (Univ. of Oxford).

__N. Suciu__,*Global random walk solutions for flow in porous media*(poster), EGU General Assembly 2015, Vienna, April, 7–12, 2019, https://meetingorganizer.copernicus.org/EGU2019/posters/30957__N. Suciu__,*Global random walk solutions for flow in porous media*(prezentare orala), European Numerical Mathematics and Advanced Applications Conference 2019, 30th sep – 4th okt 2019, Egmond aan Zee, The Netherlands, https://www.enumath2019.eu/program/day/4?man_id=536- Harko,
__M. Crăciun__, S. Liang, Testing the Bose-Einstein dark matter model with galactic rotation curves from the SPARC sample, 2019 International Mini Workshop on Composite Higgs, Dark Matter, Neutrinos, New Physics, Gauge-Higgs Unification and Related Topics, Sun Yat-sen University (SYSU), Guangzhou, China, 21-24 November 2019. - C.I. Gheorghiu,
*Finite element solutions to a Sturm-Liouville transmission eigenproblem*, 90th Annual Meeting of the International Association of Applied Mathematics and Mechanics, 18 – 22 February 2019 University of Vienna, Vienna, Austria. - C.I. Gheorghiu,
*Spectral Collocation Based on Quasi-Classical Orthogonal Polynomials Applied to Solve a Singular BVP from Hydrodynamics*, ICNAAM 2019, Rhodes, Greece - T. Grosan, I. Pop, F.O. Patrulescu,
*Transfer Phenomena in Non-Darcy Bidisperse Porous Media*, 15th International Conference on Fluid Mechanics (FLUIDS ’19), Athens, Greece, December 8-10, 2019 http://www.wseas.org/multimedia/conferences/2019/Athens-A/Program.pdf - D. Otrocol (joint work with A. Novac and D. Popa),
*Ulam stability of a linear difference equation in locally convex spaces*, International Conference on Approximation Theory and Its Applications, Alexandru Lupas, 10-13 October, 2019, Sibiu, Romania, http://conferences.ulbsibiu.ro/icata __O. Agratini__,*Non-Newtonian Calculus and Approximation Theory*, The International Conference on Approximation Theory and its Applications, Sibiu, 10-13 October 2019. (joint work with Harun Karsli)- D. Otrocol (joint work with Ioan Rasa),
*Functional equations and entropies*, The Eighteenth International Conference on Functional Equations and Inequalities (18 ICFEI), Bedlewo, Poland, June 9 – 15, 2019, https://icfei.up.krakow.pl/

- E. Cătinaș,
*Aspects regarding the convergence orders of sequences,*Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.

__O. Agratini__,*Approximation processes with flexible nodes*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__C. I. Gheorghiu__,*Spectral collocation methods based on quasi-classical orthogonal polynomials. Some numerical experiments*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__F. Pătrulescu, C.D. Alecsa, N. Suciu__,*Numerical solutions (finite element method, finite difference) for a flow problem in aquifers*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__I. Boros__,*Spectral methods with arbitrary precision for differential problems. Application to a flow problem in heterogeneous aquifers*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__M. Crăciun__, T. Harko,*About the fitting of a dark matter model on the galactic rotation curves data*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__M.-C. Anisiu__,*Families of curves and compatible potentials*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__I. Păvăloiu, E. Cătinaș__,*On the convergence of some iterative methods for nonlinear equations in R*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.__C. D. Alecsa__,*A gradient type algorithm with backward inertial steps for a nonconvex minimization*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019.- A. Novac,
__D. Otrocol__, D. Popa,*On Ulam stability of a linear difference equation in locally convex spaces*, Numerical Analysis, Approximation and Modeling, Academic Days, Cluj-Napoca, April 16, 2019. __M. Crăciun__, T. Harko,*Galactic rotation curves in Bose-Einstein Condensate dark matter models, Recent developments in astronomy, astrophysics, space and planetary sciences*, Recent developments in astronomy, astrophysics, space and planetary sciences, International Conference, 27-29 May 2019, Cluj-Napoca.- A. Pop,
__M. Crăciun__, V. Turcu,*Detection of a low level period variability in the pulsating star SZ Lyncis*, Recent developments in astronomy, astrophysics, space and planetary sciences, International Conference, 27-29 May 2019, Cluj-Napoca. __C.I. Gheorghiu__*, Two Open Problems Concerning Quasi-Periodic Eigenproblems*, CAIM 2019, Universitatea Valahia, Târgovişte.__C.I. Gheorghiu__*, On the utility of non-classical orthogonal Polynomials. Boundary value and eigenvalue problems,*ICATA 2019, Universitatea Lucian Blaga, Sibiu.

- 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.

- 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

- Mihiț T. L. Claudia-Luminița, thesis
*Concepte de splitting pentru cociclici de evoluție în spații Banach*(coord. Prof. dr. Sasu Bogdan), September 18, West University of Timisoara - Crai P. Violeta, thesis
*Concepte de dichotomie și tricotomie cu rate de creștere în spații Banach*(coord. Prof. dr. Megan Mihail), September 18, West University of Timisoara **Alecsa**L. Cristian-Daniel, thesis*Contribuții la teoria punctului fix pentru operatori univoci și multivoci definiți pe spații metrice generalizate*(coord. Prof. dr. Petrușel Adrian), October 18, 2019, Babes-Bolyai University- Parajdi I. G. Lorand-Gabriel, thesis
*Analiza unor modele matematice de dinamici celulare din hematologie*(coord. Prof. dr. Precup Radu), October 18, 2019, Babes-Bolyai University - Pop Vicuța (married Neagoș), thesis
*Procedee de interpolare și aproximare a funcțiilor*(coord. Prof. dr. Ivan Mircea), July 25, 2019, Technical University of Cluj-Napoca

**Alecsa**L. Cristian-Daniel, thesis*Contribuții la teoria punctului fix pentru operatori univoci și multivoci definiți pe spații metrice generalizate*(coord. Prof. dr. Petrușel Adrian), October 18, 2019, Babes-Bolyai University

- O. Agratini, for Apan (married Pop) Beatrix-Mihaela (supervisor Duca Dorel)

- O. Agratini for: Studia Universitatis Babeș-Bolyai Mathematica (3), Journal of Numerical Analysis and Approximation Theory (2), Constructive Mathematical Analysis (1), Positivity (1), Hacettepe Journal of Mathematics & Statistics (1), Annals of Functional Analysis (1), Open Journal of Discrete Mathematics (1), Rocky Mountain Journal of Mathematics (1), Carpathian Journal of Mathematics (1)
- C.I. Gheorghiu (to be completed)

for Mathematical Reviews:

- O. Agratini: MR4033337, MR3986896, MR3984707, MR3954368, MR3908422, MR3881252
- D. Otrocol: MR4036407, MR3959395, MR3939832

for ZBL:

- Gheorghiu: 1462.65211, 1448.65057, 1451.65198, 1404.65258, 1404.65246.

(to be completed)