Roman Dmytryshyn

Professor of Department of Mathematical and Functional Analysis
Doctor of Physical and Mathematical Sciences, Professor

 

Curriculum VitaePublicationsActivitiesContacts

PERSONAL INFORMATION

Date of birth: September 6, 1973
Address:
Department of Mathematical and Functional Analysis
Vasyl Stefanyk Precarpathian National University
vul. Shevchenka 57
Ivano-Frankivsk 76018
Ukraine
E-mail address: dmytryshynr@hotmail.com, roman.dmytryshyn@pnu.edu.ua
Web page: https://kmfa.pnu.edu.ua/en/roman-dmytryshyn/
ORCID ID: https://orcid.org/0000-0003-2845-0137
SCOPUS Author ID: https://www.scopus.com/authid/detail.uri?authorId=6508232466
Web of Science Researcher ID: https://www.webofscience.com/wos/author/record/N-4208-2019

EDUCATION

Student, Faculty of Physico-Mathematical, Vasyl Stefanyk Precarpathian University, Ivano-Frankivsk, Ukraine, 1990–1995
Post-graduate Studies, Department of Differential Equations and Theory of Functions, Pidstryhach Institute for Applied Problems of Mechanics and Mathematics of National Academy of Sciences of Ukraine, Lviv, Ukraine, 1995–1998
PhD Degree in Mathematics and Physics, Specialty Mathematical Analysis, Lviv State University, Lviv, Ukraine, 1998

Title of PhD thesis: The Multidimensional Analogs of g-fractions, Its Properties, Convergence Criterions

PhD advisor: Prof. Dr. Dmytro Bodnar

DSc Degree in Mathematics and Physics, Specialty Mathematical Analysis, Institute of Mathematics, National Academy of Sciences of Ukraine, Kyiv, Ukraine, 2019

Title of DSc thesis: Some Classes of Functional Branched Continued Fractions with Independent Variables and Multiple Power Series

MOST RECENT POSITION HELD

University or Company: Vasyl Stefanyk Precarpathian National University
Position Title: Professor (Full) of Department of Mathematical and Functional Analysis
Dates: 09/2019 –

Position Title: Professor (Associate) of Department of Economic Cybernetics
Dates: 09/2002 – 09/2019

University or Company: Ternopil National Economic University
Position Title: Professor (Associate) of Department of Automated Systems and Programming
Dates: 03/2000 – 09/2002

University or Company: Pidstryhach Institute for Applied Problems of Mechanics and Mathematics
Position Title: Researcher of Department of Differential Equations and Theory of Functions
Dates: 12/1998 – 03/2000

 

  1. Aron R.M., Dmytryshyn R., Mastyło M., Zagorodnyuk A. Recent advances in functional analysis and function theory. J. Math. Anal. Appl. 2024; 529(2): 127560. https://doi.org/10.1016/j.jmaa.2023.127560
  2.  Dmytryshyn R, Goran V. On the analytic extension of Lauricella–Saran’s hypergeometric function FK to symmetric domains. Symmetry. 2024; 16(2): 220. https://doi.org/10.3390/sym16020220
  3.  Dmytryshyn R., Lutsiv I.-A., Dmytryshyn M. On the analytic extension of the Horn’s hypergeometric function H4. Carpathian Math. Publ. 2024; 16(1): 32–39. https://doi.org/10.15330/cmp.16.1.32-39
  4. Dmytryshyn R., Cesarano C., Lutsiv I.-A., Dmytryshyn M. Numerical stability of the branched continued fraction expansion of Horn’s hypergeometric function H4. Mat. Stud. 2024; 61(1): 51–60. https://doi.org/10.30970/ms.61.1.51-60
  5.  Antonova T., Cesarano C., Dmytryshyn R., Sharyn S. An approximation to Appell’s hypergeometric function F2 by branched continued fraction. Dolomites Res. Notes Approx. 2024; 17(1): 22–31. https://doi.org/10.14658/PUPJ-DRNA-2024-1-3
  6.   Dmytryshyn R., Lutsiv I.-A., Dmytryshyn M., Cesarano C. On some domains of convergence of branched continued fraction expansions of the ratios of Horn hypergeometric functions H4. Ukr. Math. J. 2024; 76(4): 559–565. https://doi.org/10.1007/s11253-024-02338-3
  7. Aron R.M., Dmytryshyn R., Mastyło M., Zagorodnyuk A. Recent advances in functional analysis and function theory. J. Math. Anal. Appl. 2023, 127560. https://doi.org/10.1016/j.jmaa.2023.127560
  8. Antonova T., Dmytryshyn R., Sharyn S. Branched continued fraction representations of ratios of Horn’s confluent function H6. Constr. Math. Anal. 2023, 6(1), 22–37. https://doi.org/10.33205/cma.1243021
  9. Antonova T., Dmytryshyn R., Lutsiv I.-A., Sharyn S. On some branched continued fraction expansions for Horn’s hypergeometric function H4(a,b;c,d;z1,z2) ratios. Axioms. 2023, 12(3), 299. https://doi.org/10.3390/axioms12030299
  10. Antonova T., Dmytryshyn R., Kril P., Sharyn S. Representation of some ratios of Horn’s hypergeometric functions H7 by continued fractions. Axioms. 2023, 12(8), 738. https://doi.org/10.3390/axioms12080738
  11. Dmytryshyn R.I. Convergence of multidimensional A– and J-fractions with independent variables. Comput. Methods Funct. Theory. 22(2), (2022) 229–242. https://doi.org/10.1007/s40315-021-00377-6
  12. Antonova T., Dmytryshyn R., Kurka R. Approximation for the ratios of the confluent hypergeometric function Φ(N)D by the branched continued fractions. Axioms. 11(9), (2022) 426. https://doi.org/10.3390/axioms11090426
  13. Antonova T., Dmytryshyn R., Kravtsiv V. Branched continued fraction expansions of Horn’s hypergeometric function H3 ratios. Mathematics. 9(2), (2021) 148. https://doi.org/10.3390/math9020148
  14. Antonova T., Dmytryshyn R., Sharyn S. Generalized hypergeometric function 3F2 ratios and branched continued fraction expansions. Axioms 10(4), (2021) 310. https://doi.org/10.3390/axioms10040310
  15. Dmytryshyn R.I., Sharyn S.V. Approximation of functions of several variables by multidimensional S-fractions with independent variables. Carpathian Math. Publ. 13 (3), (2021) 592-607. https://doi.org/10.15330/cmp.13.3.592-607
  16. Bodnar O.S., Dmytryshyn R.I., Sharyn S.V. On the convergence of multidimensional S-fractions with independent variables. Carpathian Math. Publ. 12 (2), (2020) 353–359. https://doi.org/10.15330/cmp.12.2.353-359
  17. Antonova T.M., Dmytryshyn R.I. Truncation error bounds for branched continued fraction whose partial denominators are equal to unity. Mat. Stud. 54 (1), (2020) 3-14. https://doi.org/10.30970/ms.54.1.3-14
  18. Antonova T.M., Dmytryshyn R.I. Truncation error bounds for branched continued fraction . Ukr. Math. J. 72 (7), (2020) 1018-1029. https://doi.org/10.1007/s11253-020-01841-7
  19. Dmytryshyn R.I. Multidimensional regular C-fraction with independent variables corresponding to formal multiple power series. Proc. Roy. Soc. Edinburgh Sect. A. 150 (4), (2020) 1853-1870. https://doi.org/10.1017/prm.2019.2
  20. Dmytryshyn R.I. On some of convergence domains of multidimensional S-fractions with independent variables. Carpathian Math. Publ. 11 (1), (2019) 54–58. https://doi.org/10.15330/cmp.11.1.54-58
  21. Bodnar D.I., Dmytryshyn R.I. Multidimensional associated fractions with independent variables and multiple power series. Ukr. Math. J. 71 (3), (2019) 370-386. https://doi.org/10.1007/s11253-019-01652-5
  22. Bodnar O.S., Dmytryshyn R.I. On the convergence of multidimensional S-fractions with independent variables. Carpathian Math. Publ. 10 (1), (2018) 58–64. https://doi.org/10.15330/cmp.10.1.58-64
  23. Dmytryshyn R.I. On the convergence criterion for branched continued fractions with independent variables. Carpathian Math. Publ. 9 (2), (2017) 120–127. https://doi.org/10.15330/cmp.9.2.120-127
  24. Dmytryshyn R.I. Convergence of some branched continued fractions with independent variables. Mat. Stud. 47 (2), (2017) 150–159. https://doi.org/10.15330/ms.47.2.150-159
  25. Dmytryshyn R.I. Some properties of branched continued fractions of special form. Carpathian Math. Publ. 7(1), (2015) 72–77. https://doi.org/10.15330/cmp.7.1.72-77
  26. Dmytryshyn R.I. Associated branched continued fractions with two independent variables. Ukr. Math. J. 66 (9), (2015) 1312-1323. https://doi.org/10.1007/s11253-015-1011-6
  27. Dmytryshyn R.I. Two-dimensional generalization of the Rutishauser qd-algorithm. J. Math. Sci. 208 (3), (2015) 301-309. https://doi.org/10.1007/s11253-015-1011-6
  28. Dmytryshyn R.I. Positive definite branched continued fractions of special form. Carpathian Math. Publ. 5 (2), (2013) 225–230. https://doi.org/10.15330/cmp.5.2.225-230
  29. Dmytryshyn R.I. The two-dimensional g-fraction with independent variables for double power series. J. Approx. Theory. 164 (12), (2012) 1520-1539. https://doi.org/10.1016/j.jat.2012.09.002
  30. Dmytryshyn R.I. On the expansion of some functions in a two-dimensional g-fraction with independent variables. J. Math. Sci. 181 (3), (2012) 320-327. https://doi.org/10.1007/s10958-012-0687-5
  31. Dmytryshyn R.I. The multidimensional generalization of g-fractions and their application. J. Comput. Appl. Math. 164–165, (2004) 265–284. https://doi.org/10.1016/S0377-0427(03)00642-3
  32. Bodnar D.I., Dmytryshyn R.I. On the convergence of multidimensional g-fraction. Mat. Stud. 15 (2), (2001) 115–126. http://matstud.org.ua/texts/2001/15_2/115_126.pdf
  33. Dmytryshyn R.I. A priori estimates of the approximation errors of a multidimensional g-fraction. J. Math. Sci. 96 (2), (1999) 2948–2950. https://doi.org/10.1007/BF02169685

Research Interests:

Approximation Theory
Continued Fractions and Their Generalizations
Special Functions
Numerical Analysis

Membership in professional organizations:
American Mathematical Society, Referee in Mathematical Reviews
Ivano-Frankivsk Mathematical Society (Ukraine), Member
National Agency for Higher Education Quality Assurance (Ukraine), Expert
National Research Foundation of Ukraine, Expert
Charitable Organization «Charitable Foundation «Ivano-Frankivsk Mathematical Society» (Ukraine), Founder & Director

Membership in scientific/organizing committees of workshops/symposiums/conferences:
International Workshop on Current Trends in Analysis and Approximation Theory, July 18, 2023, Rome, Italy
International Conference «Modern Problems of Mathematics and Mechanics» dedicated to the 100th anniversary of the National Leader Heydar Aliyev, April 26-28, 2023, Baku, Azerbaijan
International E-Conference on Mathematical and Statistical Sciences: A Selcuk Meeting, October 20–22, 2022, Konya, Turkiye
International Conference «Theory of Approximation of Functions and its Applications» dedicated to the 80th Anniversary of Corresponding Member of NAS of Ukraine Prof. Alexander Stepanets (1942-2007), June 6–10, 2022, Lutsk, Ukraine
International Online Conference «Current Trends in Abstract and Applied Analysis”, May 12–15, 2022, Ivano-Frankivsk, Ukraine
International Online Workshop on Approximation Theory, March 19–21, 2021, Ivano-Frankivsk, Ukraine

Membership in editorial boards of international journals:

Editor of journals:

Axioms (MDPI)
Carpathian Mathematical Publications
Matematychni Studii
Precarpathian Bulletin of the Shevchenko Scientific Society Number

Editor of special issues:

Approximation Theory, Carpathian Mathematical Publications
Advanced Approximation Techniques and Their Applications, Axioms (MDPI)
Recent Advances in Functional Analysis and Function Theory, Journal of Mathematical Analysis and Applications (Elsevier)

International travel experience:

Internship at University of Rzeszow, Rzeszow, Poland, 2020
Mobility of higher education staff at International Telematic University UNINETTUNO, Rome, Italy, 2023

Vasyl Stefanyk Precarpatian National University
vul. Shevchenka 57
Ivano-Frankivsk 76018

E-mail address: dmytryshynr@hotmail.com, roman.dmytryshyn@pnu.edu.ua