Ştefan M. Şoltuz

The information on this webpage is no longer updated.

e-mail: soltuzul[at]yahoo.com, stefanmsoltuz[at]yahoo.com

### Academic degree:

Ph.D. in Mathematics (2004)

Thesis title: *Contributions to the theory of Mann and Ishikawa iterations*

Supervisor: Prof. dr. Iosif Kolumban

### Current position:

former member (between 1998-2014) of ICTP

### Research domains:

- Fixed Point Theory
- Functional analysis
- ODEs

version of December 2, 2022.

**Education background:**

2004 | Ph.D. in mathematics with honours at Faculty of Mathematics and Computer Science, “Babeş-Bolyai” University, Cluj |

1995-1996 | Master degree with honours at Faculty of Mathematics and Computer Science, “Babeş-Bolyai” University, Cluj-Napoca |

1991-1995 | Faculty of Mathematics and Computer Science, “Babeş-Bolyai” University, Cluj-Napoca. |

**Additional education:**

2001-2004 | Sandwich Ph. D. Program, for 34 months, in University of Kaiserslautern, at Fraunhofer-Institute fuer Techno und Wirtschaft Mathematik (ITWM), Kaiserslautern, Germany. |

**Working experience:**

1996 – 1997 | high school teacher. |

1998 – 2005 | research assistant, “Tiberiu Popoviciu” Institute of Numerical Analysis, Cluj-Napoca, Romanian Academy |

2005 – present | scientific researcher III, “Tiberiu Popoviciu” Institute of Numerical Analysis, Cluj-Napoca, Romanian Academy |

Aug. 2007- May 2008 | Assistant Professor at Universidad de los Andes (Colombia) |

**Teaching experience:**

Aug. 2007-May 2008 | Assistant Professor at Universidad de los Andes, teaching Numerical Methods (with Matlab), Differential Equations, Calculus and Linear Algebra. |

Fall 1999-Spring 2000 | Math M 211 and M 212 (Calculus): Adjunct Assistant Professor at Babes-Bolyai University, Introduction to Mathematical Analysis for students from Chemical Engineering and Chemistry. |

Fall 2003 | Math M311: Adjunct Assistant Professor at Kaiserslautern University, Functions of several variable, ODE, Minimum and Maximum problems,limits, integration (Analysis I and II). |

**Computer experience**

- Operating systems: Windows, Linux
- Programming languages: Matlab
- Word-processing languages: Scientific Work Place

**Languages**

English (fluent), French (fluent), German (fluent), Italian (fluent).

- Ş.M. Şoltuz, B.E. Rhoades,
*A mixed iteration for nonnegative matrix factorizations*, Appl. Math. Comput., 219 (2013) no. 18, 9847-9855. - V.V. Morariu, C. Vamoş, Ş.M. Şoltuz, A. Pop, L. Buimaga-Iarinca, O. Zainea,
*Autoregressive modeling of biological phenomena*, Biophysical Reviews and Letters, vol. 5 (2010) no. 3, pp. 109-128. - V.V. Morariu, C. Vamoş, A. Pop, Ş.M. Şoltuz and L. Buimaga-Iarinca,
*Autoregressive modeling of the variability of an active galaxy*, Romanian Journal of Physics, v. 55 (2010) nos. 7-8, pp. 676-686. - Ş.M. Şoltuz,
*Data dependece for strongly pseudocontractive operators*, Advances in Nonlinear Variational Inequalities, v. 13 (2010), 19-27. - Ş.M. Şoltuz,
*Inverse problems via generalized contractive operators*, Rev. Anal. Numer. Theor. Approx., 39 (2010) no. 2, 164-168. - Ş.M. Şoltuz,
*Solving inverse problems via hemicontractive maps*, Nonlinear Analysis: Theory, Methods & Applications, 71 (2009), 2387-2390. - Ş.M. Şoltuz, Solving inverse problems via weak-contractive maps, Rev. Anal. Numer. Theor. Approx., 37 (2008) no 2, pp. 217-220.
- S.M. Şoltuz,
*The equivalence between the T-stabilities of Picard-Banach and Mann-Ishikawa iterations*. Applied Math. E-Notes, 8 (2008), 109-114. - S.M., Şoltuz, T. Groşan,
*Data dependence for Ishikawa iteration when dealing with contractive-like operators*, Fixed Point Theory Appl. 2008, article ID 242916. - S.M. Şoltuz, B.E. Rhoades,
*Characterization for the convergence of Krasnoselskij iteration for non-Lipschitzian operators*, Int. J. Math. Math. Sci. 2008, article ID 630589. - S.M. Soltuz, Stability of solutions for a class of minimization problems, Tamkang J. Math., 17 (2007) no. 4, 17-30.
- Ş.M. Şoltuz, D. Otrocol,
*Classical results via Mann-Ishikawa iteration*, Rev. Anal. Numer. Theor. Approx., 36 (2007) no. 2, 193-197. - Ş.M. Şoltuz, D. Otrocol,
*The convergence of Mann iteration with delay*, Mathematical Sciences Research, 11 (2007) no. 3, pp. 390-393. - Ş. Şoltuz,
*The convergence of modified Mann-Ishikawa iterations when applied to an asymptotically pseudocontractive map*, Austral. J. Math Anal. Appl., 4 (2007) no. 2. - V.V. Morariu, L. Buimaga-Iarinca, C. Vamoş, Ş.M. Şoltuz,
*Detrended fluctuation analysis of autoregressive processes*, Fluct. Noise Lett., 7, L249-L255, 2007. - Ş.M. Şoltuz,
*The equivalence between Krasnoselskij, Mann, Ishikawa, Noor and multistep iterations*, Math. Commun. 12 (2007) no. 1, 53-61. - C. Vamoş, Ş.M. Şoltuz, M. Crăciun,
*Order 1 autoregressive process of finite length*, Rev. Anal. Numér. Théor. Approx., 36 (2007) no. 2, pp. 201-216. - Ş.M. Şoltuz,
*The equivalence between T-stabilities of the Krasnoselskij and the Mann iterations*, Fixed Point Theory and Applications, (2007) art. id. 60732. - B.E. Rhoades, Ş.M . Şoltuz,
*The equivalence between the T-stabilities of Mann and Ishikawa iterations*, J. Math. Anal. Appl. 318 (2006), 472-475. - B.E. Rhoades, Ş.M . Şoltuz,
*The convergence of an implicit mean value iteration*, Int. J. Math. Math. Sci. 2006 ID 68369, 7 p. - B.E. Rhoades, Ş.M. Şoltuz,
*The equivalence of Mann and Ishikawa iterations dealing with uniformly pseudocontractive maps without bounded range*, Tamkang J. Math. 37 (3) (2006). - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence between Mann and Ishikawa iterations dealing with generalized contractions*, Int. J. Math. Math. Sci. 2006, article ID 54653. - Ş.M. Şoltuz,
*Errors estimation for implicit Mann iteration*, Rev. Anal. Numer. Theor. Approx. 35 (2006) no. 1, 117-118. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence between the Krasnoselskij, Mann and Ishikawa iterations*, Rev. Anal. Numer. Theor. Approx. 35 (2006) no. 2, 199-205. - Ş.M. Şoltuz,
*The equivalence between the T-stabilities of modified Mann-Ishikawa and Mann-Ishikawa iterations*, Rev. Anal. Numer. Theor. Approx. 35 (2006) no. 2, 221-224. - B.E. Rhoades, Ş.M. Şoltuz ,
*The convergence of mean value iteration for a family of maps*, Int. J. Math. Math. Sci. 2005: 21, 3479-3485. - B.E. Rhoades and Ş.M. Şoltuz,
*The class of asymptotically demicontractive maps is a proper subclass of asymptotically pseudocontractive maps*, PanAmerican Mathematical Journal Volume 16 (2006) no 2, 93-97. - B.E. Rhoades and Ş.M. Şoltuz,
*Mean value iteration for a family of functions*, Nonlinear Funct. Anal. Appl.,10 (2005) no. 3, pp. 387-401. - Ş.M. Şoltuz,
*The equivalence of Picard, Mann and Ishikawa iterations dealing with quasi-contractive operators*, Math. Commun. 10 (2005) no. 2, 81-88. - Ş.M. Şoltuz,
*New technique for proving the equivalence of Mann and Ishikawa iterations*, Rev. Anal. Numer. Theor. Approx., 34 (2005) no. 1, 103-108. - B.E. Rhoades and Ş.M. Şoltuz,
*The Mann and Ishikawa iterations and the Mann-Ishikawa with errors are equivalent models dealing with a non-Lipschitzian map*, Rev. Anal. Numer. Theor. Approx., 34 (2005) no. 2, 181-193. - Ş.M. Şoltuz,
*On the boundedness of the associated sequence of Mann iteration for several operator classes with applications*, Rev. Anal. Numer. Theor. Approx., 34 (2005) no. 2, 227-232. - Ş.M. Şoltuz,
*A remark concerning the paper “An equivalence between the convergence of Ishikawa, Mann and Picard iterations”*, Rev. Anal. Numer. Theor. Approx. 33 (2004) no. 1, 95-96. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence of Mann and Ishikawa iterations dealing with strongly pseudocontractive or strongly accretive maps*, PanAmerican Mathematical Journal, 14 (2004) no. 4, 51-59. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence between Mann-Ishikawa iterations and multistep iteration*, Nonlinear Analysis: Theory, Methods & Applications, 58 (2004) no. 1-2, 219-228. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence of Mann and Ishikawa iteration for a Lipschitzian ψ-uniformly pseudocontractive and ψ-uniformly accretive map*, Tamkang J. Math. 35 (2004), 235-245. - B.E. Rhoades and Ş.M. Şoltuz,
*The Equivalence of Mann Iteration and Ishikawa iteration for ψ-uniformly pseudocontractive or ψ-uniformly accretive maps*, Internat. J. Math. Sci. 2004: 46, 2443-2451. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence between the convergences of Ishikawa and Mann iterations for asymptotically nonexpansive in the intermediate sense and strong successively pseudocontractive maps*, J. Math. Anal. Appl. 289 (2004), 266-278. - Ş.M. Şoltuz,
*Mann-Ishikawa iterations and Mann-Ishikawa iterations with errors are equivalent models*, Math. Commun. 8 (2003) no. 2, 139-151. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence between the convergences of Ishikawa and Mann iterations for asymptotically pseudocontractive map*, J. Math. Anal. Appl. 283 (2003), 681-688. - B.E. Rhoades and Ş.M. Şoltuz,
*The equivalence of Mann iteration and Ishikawa iteration for non-Lipschitzian operators*, Internat. J. Math. Math. Sci. 2003 (42), 2645-2652. - B.E. Rhoades and Ş.M. Şoltuz,
*On the equivalence of Mann and Ishikawa iteration methods*, Internat. J. Math. Math. Sci. 2003 (7), 451-459. - Ș.M. Șoltuz,
*The convergence of mann iteration for an asymptotic hemicontractive map*, Buletinul ştiinţific al Universitatii Baia Mare, Seria B, Fascicola matematică-informatică, 18 (2002) no. 1, pp. 115-118. - Ş.M. Şoltuz,
*A correction for a result on convergence of Ishikawa iteration for strongly pseudocontractive maps*, Math. Commun. 7 (2002) no. 1, 61-64. - Ş.M. Şoltuz,
*Mann iteration for direct pseudocontractive maps*, Bull. Stiint. Univ. Baia Mare, Ser. B, Fasc. Mat.-Inform., 17 (2001) nos. 1-2, 141-144. - Ş.M. Şoltuz,
*Mann iteration for generalized pseudocontractive maps in Hilbert spaces*, Math. Commun. 6 (2001) no. 1, 97-100. - Ş.M. Şoltuz,
*Sequence supplied by inequalities and an application*, (Co- Editors Yeol Je Cho, Jong Kyu Kim, Sever S. Dragomir, Inequality Theory and Applications vol. 2, Nova Publishers Inc. New York 2002, USA). - Ş.M. Şoltuz,
*Sequences supplied by inequalities*, Revue Anal. Numer. Theor. Approx. 29 (2000) no. 2, 207-212. - Ş.M. Şoltuz,
*The backward Mann iteration*, Octogon Math. Mag. 9 (2001):2, 797-800. - Ş.M. Şoltuz,
*Three proofs for the convergence of a sequence*, Octogon Math. Mag. 9 (2001):1, 503-505. - Ş.M. Şoltuz,
*Characterization of inner product spaces*, Octogon Math. Mag. 9 (2001):1, 482-487. - Ş.M. Şoltuz,
*The multivalued form of a classic result*, Octogon Math. Mag. 7 (1999):2, 97-98. - Ş.M. Şoltuz,
*Upon the convergence of subconvex sequences*, Octogon Math. Mag .6 (1998):2, 120-121.