  In this paper, we find regular or biregular Hadamard matrices with maximum
excess by negating some rows and columns of known Hadamard matrices obtained
from quadratic residues of finite fields. In particular, we show that if either
$4m^2+4m+3$ or $2m^2+2m+1$ is a prime power, then there exists a biregular
Hadamard matrix of order $n=4(m^2+m+1)$ with maximum excess. Furthermore, we
give a sufficient condition for Hadamard matrices obtained from quadratic
residues being transformed to be regular in terms of four-class translation
association schemes on finite fields.
