ROBERT JAJCAY

                                   
Bratislava, Slovakia


LOCATION AND CONTACT

Room: M137

Department: Katedra algebry a geometrie

University: Fakulta matematiky, fyziky a informatiky Univerzity Komenskeho
Mlynska dolina, 842 48, Bratislava

Phone: +421 (0)2 602 95642 (office)

Mail: robert.jajcay@fmph.uniba.sk

Office of Doctoral Studies: F2-92, +421 (0)2 602 95194 rdrs@fmph.uniba.sk

                 






FALL 2024 SCHEDULE

Monday

8:10 - 9:40, B, 1-MAT-490/00, Linear Algebra and Geometry
11:30 - 13:00, M-VII, 2-MAT-224/09, Linear Coding
13:00 - 13:30, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Tuesday

11:00 - 11:30, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Wednesday

Thursday

8:10 - 9:40, M-V, 1-MAT-460/00, Graph Theory
09:50 - 11:20, M213, Graph Theory Seminar
11:30 - 12:00, F2- 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Friday

13:10 - 14:40, M-XI, Algebraic Graph Theory Seminar






EDUCATION

Ph.D. Mathematics/Computer Science (minor), May, 1995

University of Nebraska-Lincoln, Lincoln, Nebraska

Research specialty: Algebraic Combinatorics

Dissertation: Vertex-transitive graphs and maps and their automorphism groups

Advisor: Professor Spyros S. Magliveras


RNDr., summa cum laude, Mathematics
Comenius University, Bratislava, Slovakia, 1988


                 




MOST RECENT PUBLICATIONS AND PROFESSIONAL ACTIVITIES


T.B. Jajcayova and R. Jajcay, Totally Regular Mixed Graphs Constructed from the CD(n,q) Graphs of Lazebnik, Ustimenko and Woldar,
accepted for publication in ADAM.

R. Jajcay, J. Siran and Y. Wang, Generalized Cayley maps and their Petrie duals,
Ars Math. Contemp. 24, No. 3, Paper No. 1, 19 p. (2024)

T.B. Jajcayova and R. Jajcay, Generalizations of Cayley graphs to uniform hypergraphs,
Art Discrete Appl. Math., 2024, doi:10.26493/2590-9770.1606.28a

S. Gyurki, R. Jajcay, P. Janos, J. Siran and Y. Wang, Using bi-coset graphs to construct small regular and biregular graphs,
Discrete Mathematics 347 (5), 2024.

G. Exoo, R. Jajcay and T. Raiman, On decreasing the orders of (k,g)-graphs,
Journal of Combinatorial Optimization, 2023, 46(4), 26

Support files for S. Gyurki, R. Jajcay, P. Janos, J. Siran and Y. Wang,
Using bi-coset graphs to construct small regular and biregular graphs


L. Eze, R. Jajcay and D. Mihalova, An algorithmic approach to determining spectra of orders of (k,g)-graphs,
ITAT 2023 Proceedings, CEUR Workshop Proceedings Vol. 3498 (2023) 204 - 208.

ALL PUBLICATIONS

Member of the Editorial Board of Ars Mathematica Contemporanea,
Art of Discrete and Applied Mathematics, and Acta Mathematica Universitatis Comenianae




TEACHING EXPERIENCE

Educational Excellence Award, College of Arts and Sciences, ISU, April 1999

Teaching Award awarded by the Dean of FMFI UK, Faculty of Mathematics, Physics and Informatics of the Comenius University, November, 2018



POSTDOCTORAL VISITORS

Shasha Zheng, January 16, 2024 - January 15, 2025

Fatemeh Koorepazan Moftakhar, April 1, 2022 - March 30, 2023

Slobodan Filipovski, December 1, 2019 - November 30, 2020, currently at the University of Primorska, Koper, Slovenia

Sara Sabrina Zemljic, December 1, 2017 - November 30, 2018

Christian Rubio Montiel, January 1 - December 31, 2016, currently at FES Acatlan, National Autonomous University of Mexico



DOCTORAL STUDENTS

Tom Raiman, PhD., 2023, VSB-TU Ostrava, Extremal graphs of prescribed degree and girth

Milan Lekar, PhD., 2022, Comenius University, The impact of emigration on the development of Mathematics in Slovakia

Slobodan Filipovski, PhD., 2018, University of Primorska, On extremal graphs of given degree and diameter/girth



MASTER STUDENTS

Juraj Belohorec, MSc, 2024, Comenius University, Code based cryptography

Branislav Boran, MSc, 2022, Comenius University, Vlastnosti a symetrie linearnych kodov generovanych incidencnymi maticami regularnych grafov s malym obvodom

Marek Murin, MSc, 2021, Comenius University, Two-dimensional recurrence relations and enumeration of locally testable matrices

Dominik Holly, MSc, 2020, Comenius University, Codes with Prescribed Automorphism Groups

Ajda Zavrtanik Drglin, MSc, 2019, University of Ljubljana, Girth-Regular and Edge-Girth-Regular Graphs

Nicole Durisova, MSc, 2019, Comenius University, Rekurentne postupnosti v linearnej algebre

Juraj Karlubik, MSc, 2018, Comenius University, Vyuzitie softveroveho balika GAP na vytvaranie a testovanie hypotez v algebraickej teorii grafov

Katarina Jasencakova, MSc, 2017, Comenius University, m-Spanning Generalized Petersen Graphs

Viktor Hirschner, MSc, 2017, Comenius University, Recursive Constructions of Regular Graphs

Martin Bachraty, MSc, 2015, Comenius University, Powers of Skew-Morphisms

Tomas Peitl, MSc, 2015, Comenius University, Applications of Number Theory to Homomorphic Encryption

Michael Cameron , MSc, 1998, Indiana State University, Constructing Regular Cayley Maps Using Computers



BACHELOR STUDENTS

Valter Cingel, 2024, Dolne ohranicenia maximalnej hodnosti netrivialnych ciastocnych automorfizmov jednoduchych grafov

Juraj Belohorec, 2022, Mathematical and Algorithmic Foundations of Attacks on the Knapsack Problem Based Cryptographic Protocols

Alexandra Racikova, 2022, Matematicke zaklady zdielania tajomstva v kryptografii

Damian Konig, 2020, Vyuzitie metod linearnej algebry v autentifikacii s nulovou stratou informacie

Jakub Skoda, 2020, Discrete Logarithm and Integer Factorization

Jana Valigurska, 2019, Symmetric Codes

Veronika Zajceva, 2017, Vyuzitie metod linearnej algebry na vyhladavanie extremalnych grafov

Justina Karlovska, 2017, Vyuzitie metod linearnej algebry na vyhladavanie extremalnych grafov

Veronika Martisova, 2016, Aplikacie teorie sifrovania v internetovej komunikacii

Kamil Bena, 2016, Perfektne linearne a nelinearne kody

Katarina Dunikova, 2015, Applications of Game Theory in Pricing Strategy Selection

Katarina Jasencakova, 2015, Use of Lifting Techniques in Vertex-Transitive Graph Constructions

Martin Bachraty, 2013, Powers of Skew-Morphisms



GRANTS AWARDED

Exceptional structures in Discrete Mathematics: Properties, constructions and classifications,
APVV-23-0076, 2024-2028

Constructions of expanders and extremal graphs,
SK-AT-23-0019 , 2024-2026

Algebraic methods in extremal graph theory,
VEGA 1/0437/23, 2023-2026

Exceptional structures in Discrete Mathematics,
APVV-19-0308, 2020-2024 (with M. Skoviera)

Combinatorial structures with prescribed symmetries,
VEGA 1/0423/20, 2020-2022

Vyuzitie algebraickych a vypoctovych metod na riesenie klasickych problemov extremalnej teorie kombinatorickych struktur,
VEGA 1/0596/17, 2017-2019 (with M. Macaj)

Algebraicke, topologicke a kombinatoricke metody v studiu diskretnych struktur,
APVV-15-0220, 2016-2018 (with M. Skoviera)

Graphs and Related Structures,
VEGA 1/0474/15, 2015-2017 (with M. Skoviera)

Applications of inverse semigroups in combinatorics,
VEGA 1/0577/14, (with T.B. Jajcayova)

Project: Mobility,
ITMS code: 26110230082, (with R. Nedela)

National Science Foundation of China,
NSFC 11371307, (with Yan Wang)

Algebraic, Topological and Combinatorial Structures on Graphs,
APVV, 2011 - 2014, (with M. Skoviera)

Research and Development Cooperation Slovakia -- China,
2011 - 2012, (with R. Nedela)

Algebraic, Combinatorial and Topological Structures on Graphs,
APVV, 2008 - 2010 (with M. Skoviera)

Symmetric graphs and maps,
VEGA, 2002 - 2004 (with J. Siran)

US - Slovenia cooperation,
awarded by the Slovenian Ministry of Science, 2002 - 2006 (with D. Marusic)

National Research Council's Collaboration in Basic Science and Engineering (COBASE),
2002 (with D. Marusic)

Summer research grants
awarded by the Indiana State University Research Council, 1996, 1998, 2004, 2009



CONFERENCES ORGANIZED

EUROCOMB 2019
August 26 - 30, 2019, Bratislava, Slovakia

Trojkralova konferencia 2016
January 4, 2016, Bratislava, Slovakia

IWONT 2014, The 6th International Workshop on Optimal Network Topologies
June 30 - July 4, 2014, Bratislava, Slovakia

Midwest Graph Theory Conference, MIGHTY LII
Terre Haute, IN, April 27-28, 2012

Indiana Section of the Mathematical Association of America
Terre Haute, IN, April 2-3, 2004

Midwestern Conference on Combinatorics, Cryptography and Computing
Terre Haute, IN, Oct.30 - Nov. 1, 1997



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