Bounds and constructions for binary asymmetric error-correcting codes

By use of known bounds on constant-weight binary codes, new uppper bounds are obtained on the cardinality of binary codes correcting asymmetric errors. Some constructions are exhibited that come close to these bounds. For single-error-correcting codes some constructions are derived from the Steiner system S(5, 6,12) , and for double-error-correcting codes some constructions are derived from the Nordstrom-Robinson code.