Title
On some double circulant codes of Crnković and disproof of his two conjectures.
Abstract
Crnković (2014) introduced a self-orthogonal 2 q , q - 1 code and a self-dual 2 q + 2 , q + 1 code over the finite field F p arising from orbit matrices for Menon designs, for every prime power q , where q ź 1 ( mod 4 ) and p a prime dividing q + 1 2 . He showed that if q is a prime and q = 12 m + 5 , where m is a non-negative integer, then the self-dual 2 q + 2 , q + 1 code over F 3 is equivalent to a Pless symmetry code. However for other values of q , he remarked that these codes, up to his knowledge, do not belong to some previously known series of codes. In this paper, we describe an equivalence between his self-dual codes and the known codes introduced by Gaboritźin 2002. On the other hand, Crnković (2014) also conjectured that if p = q + 1 2 is a prime, the self-orthogonal code and the self-dual code have minimum distance p + 3 . We disprove this conjecture by giving two counter-examples in the case of the self-orthogonal code and the self-dual code, respectively when q = 25 and p = 13 .
Year
DOI
Venue
2016
10.1016/j.disc.2016.03.016
Discrete Mathematics
Keywords
Field
DocType
Block design,Linear codes,Self-dual codes,Orbit matrix
Integer,Prime (order theory),Discrete mathematics,Combinatorics,Finite field,Group code,Circulant matrix,Linear code,Prime power,Conjecture,Mathematics
Journal
Volume
Issue
ISSN
339
9
0012-365X
Citations 
PageRank 
References 
0
0.34
3
Authors
2
Name
Order
Citations
PageRank
Dong-Man Heo100.34
Jon-Lark Kim231234.62