O jednom problému z theorie kodování
We introduce two new classes of codes, namely adjacent codes and codes with finite interpreting delay. For each class, we establish an extension of the defect theorem.
In this paper we consider the extremal even self-dual -additive codes. We give a complete classification for length . Under the hypothesis that at least two minimal words have the same support, we classify the codes of length and we show that in length such a code is equivalent to the unique -hermitian code with parameters [18,9,8]. We construct with the help of them some extremal -modular lattices.
In this paper we present 35 new extremal binary self-dual doubly-even codes of length 88. Their inequivalence is established by invariants. Moreover, a construction of a binary self-dual [88, 44, 16] code, having an automorphism of order 21, is given.*This work was partly supported by the Norwegian Government Scholarship.