13 citations · 68 across the 19 of their papers we have counts for
24 papers
Equivalence of Complex Hadamard Matrices
Patric R. J. Östergård, Tuomo Valtonen
Symmetry in the context of equivalence or isomorphism is a fundamental and natural concept in any study of discrete structures. Symmetries are also important for non-discrete struc…
Spherical codes with prescribed signed permutation automorphisms inside shells of low-dimensional integer lattices
Ganzhinov Mikhail, Östergård Patric R. J
Let be the maximum size of a code containing only vectors of the th shell of the integer lattice such that the inner product between distinct…
Improving Uniquely Decodable Codes in Binary Adder Channels
József Balogh, The Nguyen, Patric R. J. Ostergard +2
We present a general method to modify existing uniquely decodable codes in the -user binary adder channel. If at least one of the original constituent codes does not have averag…
Enumerating Steiner Triple Systems
Daniel Heinlein, Patric R. J. Östergård
Steiner triple systems (STSs) have been classified up to order 19. Earlier estimations of the number of isomorphism classes of STSs of order 21, the smallest open case, are discour…
Switching 3-edge-colorings of cubic graphs
Jan Goedgebeur, Patric R. J. Östergård
The chromatic index of a cubic graph is either 3 or 4. Edge-Kempe switching, which can be used to transform edge-colorings, is here considered for 3-edge-colorings of cubic graphs.…
On the Structure of Small Strength- Covering Arrays
Janne I. Kokkala, Karen Meagher, Reza Naserasr +3
A covering array of strength is an array of symbols from an alphabet of size such that in every subarray, every -tuple occur…