ROBERT JAJCAY

                                   
Bratislava, Slovakia


LOCATION AND CONTACT

Room: M144

Department: Katedra algebry, geometrie a didaktiky matematiky

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







SUMMER 2018 SCHEDULE

Monday

9:00 - 9:45, M-V, Linearna algebra a geometria
10:30 - 11:00, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Tuesday

11:30 - 12:00, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Wednesday

09:00 - 09:45, M-126, Linearna algebra a geometria
10:30 - 11:00, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies
14:50 - 16:20, M-126, Linearne kodovanie

Thursday

08:10 - 09:40, I-23 Vybrane kapitoly z kryptologie
09:50 - 11:20, M213, Graph Theory Seminar
11:30 - 12:00, F2 - 92, Uradne hodiny na referate DRS / Office hours doctoral studies

Friday

08:10 - 09:40, F1-328, Linearna algebra a geometria
13:30 - 15:00, 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


G. Exoo, R. Jajcay, M. Macaj and J. Siran, On the defect of vertex-transitive graphs of given degree and diameter,
J. Comb. Theory, Series B, 134 (2019), 322-340.

S. Filipovski and R. Jajcay, On the non-existence of families of (d,k,delta)-digraphs containing only selfrepeat vertices,
Linear Algebra and its Applications 563 (2019), 302-312.

R. Jajcay, T. Jajcayova and M. Opial, Enumeration of matrices with prohibited bounded sub-windows,
ITAT 2018 Proceedings, CEUR Workshop Proceedings Vol. 2203 (2018).

R. Jajcay, Gy. Kiss and S. Miklavic, Edge-girth-regular graphs,
Europ. J. of Comb. 72 (2018), 70-82.

S. Filipovski and R. Jajcay, On the excess of vertex-transitive graphs with given degree and girth,
Discrete Math. 341, No. 3 (2018), 772-780.

M. Bachraty and R. Jajcay, Classification of coset-preserving skew-morphisms of finite cyclic groups,
Australasian Journal of Combinatorics, Vol. 67 (2) (2017), 259-280.

T.B. Jajcayova, S. Filipovski and R. Jajcay, Counting cycles in graphs with small excess,
Lecture Notes of Seminario Interdisciplinare di Matematica Vol. 14 (2016), 17-36.

G.A. Jones and R. Jajcay, Cayley properties of merged Johnson graphs,
Journal of Algebraic Combinatorics 44 (2016), 1047-1067.

T.B. Jajcayova, S. Filipovski and R. Jajcay, Improved lower bounds for the orders of even-girth cages,
The Electronic Journal of Combinatorics 23(3) (2016), #P3.55.

M. Bachraty and R. Jajcay, Powers of skew-morphisms,
in Symmetries in Graphs, Maps, and Polytopes, 5th SIGMAP Workshop, West Malvern, UK, July 2014 (J. Siran and R. Jajcay, ed.),
Springer Proceedings in Mathematics & Statistics 159 (2016), 1-26.

G. Exoo and R. Jajcay, Biregular cages of odd girth,
J. Graph Theory 81, No. 1 (2016), 50-56.

G. Araujo-Pardo, G. Exoo and R. Jajcay, Small biregular graphs of even girth,
Discrete Math. 339, No. 2 (2016), 658-667.

M. Conder, R. Jajcay, and T. Tucker, Cyclic complements and skew morphisms of groups,
J. Algebra 453 (2016), 68-100.


ALL PUBLICATIONS


J. Siran, R. Jajcay (Eds.), Symmetries in Graphs, Maps, and Polytopes, 5th SIGMAP Workshop, West Malvern, UK, July 2014,
Springer Proceedings in Mathematics & Statistics 159 (2016).

Member of the Editorial Board of Ars Mathematica Contemporanea




TEACHING EXPERIENCE

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



POSTDOCTORAL VISITORS

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

Sara Sabrina Zemljic, December 1 - November 30, 2018



MASTER STUDENTS

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

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

Vyuzitie algebraickych a vypoctovych metod na riesenie klasickych problemov extremalnej teorie kombinatorickych strukt,
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

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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