Historically, coding theory has dealt with binary
codes correcting symmetric errors, in which errors are
made in both 0 and 1 bits with equal likelihood.
Within the past ten years, some study has been made of
asymmetric codes, under the assumption that the only
errors which occur are errors in...
Various problems related to systematic error-detecting
and error-correcting unidirectional codes are discussed.
Systematic codes with r check bits are the main topic of
the thesis. Classes of codes are presented which work for
specific numbers of information bits and then a class of
codes is given which detects the same...
An extensive theory of symmetric error control coding has been developed in the last few decades. The recently developed VLSI circuits, ROM, and RAM memories have given an impetus to the extension of error control coding to include asymmetric and unidirectional types of error control. The maximal numbers of unidirectional...
The bulk of the theory on error control codes has been developed under the
fault assumption of random (symmetric) errors, where 1 → 0 and 0 → 1 errors are
equally likely. In the past few years, several applications have emerged in which the
observed errors are highly asymmetric. This...