Univerza na Primorskem Fakulteta za matematiko, naravoslovje in informacijske tehnologije
SI | EN

Raziskovalni matematični seminar - Arhiv

2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010
1 2 3 4 5 6 7 8 9 10 11 12
Datum in ura / Date and time: 4.10.21
(10:00 -- 11:00)
Predavalnica / Location: Zoom
Predavatelj / Lecturer: Didem Gözüpek (Gebze Technical University, Turkey)
Naslov / Title: TRIANGLE-FREE EQUIMATCHABLE GRAPHS
Vsebina / Abstract:

A graph is called equimatchable if all of its maximal matchings have the same size. Frendrup et.al. provided a characterization of equimatchable graphs with girth at least 5. In this work, we extend this result by providing a complete structural characterization of equimatchable graphs with  girth at least 4, that is, equimatchable graphs with no triangle, by identifying the equimatchable triangle-free graph families. Our characterization also extends the result given by Akbari et. al.  which proves that the only connected triangle-free equimatchable r-regular graphs are C5, C7 and Kr,r, where r is a positive integer. Given a non-bipartite graph, our characterization implies a linear time recognition algorithm for triangle-free equimatchable graphs.

Join Zoom Meeting Here.

 See you there!

 This Monday, October 4,  2021, from 10 am to 11 am.

 Everyone is welcome and encouraged to attend.

 


Datum in ura / Date and time: 11.10.21
(10:00 -- 11:00)
Predavalnica / Location: Zoom
Predavatelj / Lecturer: Galina Filipuk (University of Warsaw, Poland)
Naslov / Title: ASPECTS OF NONLINEAR DIFFERENTIAL EQUATIONS
Vsebina / Abstract:

In this talk I shall speak about Painleve equations, special nonlinear differential equations of second order, that appear in many applications. 

I shall explain relation to the recurrence coefficients of certain semiclassical orthogonal polynomials and also show related Hamiltonian systems.

Join Zoom Meeting Here.

 See you there!

 This Monday, October 11,  2021, from 10 am to 11 am.

 Everyone is welcome and encouraged to attend.

  


Datum in ura / Date and time: 18.10.21
(10:00 -- 11:00)
Predavalnica / Location: Zoom
Predavatelj / Lecturer: Yushi Uno ( Osaka Prefecture University, Japan)
Naslov / Title: Gounds: a sliding-block puzzle with turning
Vsebina / Abstract:

We propose a new kind of sliding-block puzzle, called Gourds, where the objective is to rearrange 1 x 2 pieces on a hexagonal grid board of 2n + 1 cells with n pieces, using sliding, turning, and pivoting moves. This puzzle has a single empty cell on a board and forms a natural extension of the 15-puzzle to include rotational moves. We analyze the puzzle and completely characterize the cases when the puzzle can always be solved. We also study the complexity of determining whether a given set of colored pieces can be placed on a colored hexagonal grid board with matching colors. We show this problem is NP-complete for arbitrarily many colors, but solvable in randomized polynomial time if the number of colors is a fixed constant.
 

Join Zoom Meeting Here.

 See you there!

 This Monday, October 18,  2021, from 10 am to 11 am.

 Everyone is welcome and encouraged to attend.