56 citations · 269 across the 60 of their papers we have counts for
7 papers · 1 filter
Optimal Self-Dual Z4-Codes and a Unimodular Lattice in Dimension 41
Masaaki Harada
For lengths up to 47 except 37, we determine the largest minimum Euclidean weight among all Type I Z4-codes of that length. We also give the first example of an optimal odd unimodu…
Some Extremal Self-Dual Codes and Unimodular Lattices in Dimension 40
Stefka Bouyuklieva, Iliya Bouyukliev, Masaaki Harada
In this paper, binary extremal singly even self-dual codes of length 40 and extremal odd unimodular lattices in dimension 40 are studied. We give a classification of extremal singl…
An Optimal Odd Unimodular Lattice in Dimension 72
Masaaki Harada, Tsuyoshi Miezaki
It is shown that if there is an extremal even unimodular lattice in dimension 72, then there is an optimal odd unimodular lattice in that dimension. Hence, the first example of an…
Singly-even self-dual codes with minimal shadow
Stefka Bouyuklieva, Wolfgang Willems
In this note we investigate extremal singly-even self-dual codes with minimal shadow. For particular parameters we prove non-existence of such codes. By a result of Rains \cite{Rai…
On the Residue Codes of Extremal Type II Z4-Codes of Lengths 32 and 40
Masaaki Harada
In this paper, we determine the dimensions of the residue codes of extremal Type II Z4-codes for lengths 32 and 40. We demonstrate that every binary doubly even self-dual code of l…
A complete classification of doubly even self-dual codes of length 40
Koichi Betsumiya, Masaaki Harada, Akihiro Munemasa
A complete classification of binary doubly even self-dual codes of length 40 is given. As a consequence, a classification of binary extremal self-dual codes of length 38 is also gi…