3 papers
math.CO2025
Unbiased weighing matrices of weight
Makoto Araya, Masaaki Harada, Hadi Kharaghani +2
We investigate unbiased weighing matrices of weight and provide a construction method using mutually suitable Latin squares. For , we determine the maximum size among…
math.CO2024
On the classification of skew Hadamard matrices of order 36 and related structures
Makoto Araya, Masaaki Harada, Hadi Kharaghani +2
Two skew Hadamard matrices are considered {\sf SH}-equivalent if they are similar by a signed permutation matrix. This paper determines the number of {\sf SH}-inequivalent skew Had…
cs.IT2024
A method for constructing quaternary Hermitian self-dual codes and an application to quantum codes
Masaaki Harada
We introduce quaternary modified four -circulant codes as a modification of four circulant codes. We give basic properties of quaternary modified four -circulant Hermitian se…