2017-04-10 10:00-11:00 FAMNIT-POŠTA Sanja Rukavina (University of Rijeka, Croatia) Quasi-symmetric designs derived from AG(3,4) Some connections between designs and codes will be discussed. Further, we present the enumeration of quasi-symmetric 2-(64,24,46) designs supported by the dual code C^{\perp} of the…
2017-04-03 10:00-11:00 FAMNIT-POŠTA Dean Crnković (University of Rijeka, Croatia) On some regular Hadamard matrices and related codes A Hadamard matrix of order m is a (m \times m) matrix H=( h_{i,j}), h_{i,j} \in \{ -1,1 \}, satisfying HH^T=H^TH=mI_m, where I_m…
2017-03-27 10:00-11:00 FAMNIT-POŠTA Slobodan Filipovski (UP IAM, UP FAMNIT) On bipartite cages of excess 4 The Moore bound M(k,g) is a lower bound on the order of k-regular graphs of girth g (denoted (k,g)-graphs). The excess e of a (k,g)-graph…
2017-03-24 9:30-10:30 FAMNIT-POŠTA Matthew Johnson (Durham University, England) Kempe equivalence in regular graphs Let G be a graph with a proper vertex colouring. Let a and b be two of the colours. Then a connected component of the subgraph induced…
2017-03-20 10:00-11:00 FAMNIT-POŠTA Daniel Paulusma (Durham University, England) Colouring Diamond-free Graphs The Colouring problem is that of deciding, given a graph G and an integer k, whether G admits a (proper) k-colouring. For all graphs H up to five vertices,…
2017-03-13 10:00-11:00 FAMNIT-POŠTA Tomaž Pisanski (University of Primorska) What have we learned from the visit of the President of the ERC in Slovenia? The aim of this talk is to analyze poor performance of Slovenia at the ERC grant calls.…
2017-03-06 10:00-11:00 FAMNIT-POŠTA Andrea Munaro (Université Grenoble Alpes, France) Boundary Classes for Graph Problems Involving Non-Local Properties Many NP-hard graph problems remain NP-hard even for restricted classes of graphs, while they become polynomial-time solvable when further restrictions are applied. It…
2017-02-27 10:00-11:00 FAMNIT-POŠTA Daniel Pellicer (National Autonomous University of Mexico (UNAM)) Chiral 4-polytopes in space In this talk we adopt the notion of skeletal polytope introduce by Grunbaum in the second half of the 20th Century. A polygon is then…
2017-02-20 10:00-11:00 FAMNIT-POŠTA Yan-Quan Feng (Beijing Jiaotong University, China) Cayley digraphs of 2-genetic groups of prime-power order A group is called 2-genetic if each normal subgroup of the group can be generated by two elements. Let G be a non-abelian…