ARS COMBINATORIA, cilt.71, ss.239-247, 2004 (SCI İndekslerine Giren Dergi)
One of the most important problems of coding theory is to construct codes with the best possible minimum distance. The class of quasi-cyclic codes has proved to be a good source for such codes. In this paper, we use the algebraic structure of quasi-cyclic codes and the BCH type bound introduced in  to search for quasi-cyclic codes which improve the minimum distances of the best-known linear codes. We construct 11 new linear codes over GF(8) where 3 of these codes are one unit away from being optimal.