Sawchuck, Natalie2008-12-302008-12-3020082008-12-30http://hdl.handle.net/1828/1315A permutation array, represented by PA(n, d), is a subset of Sn such that any two distinct elements have a distance of at least d where d is the number of differing positions. We analyze the upper and lower bounds of permutation codes with distance equal to 4. An optimization problem on Young diagrams is used to improve the upper bound for almost all n while the lower bound is improved for small values of n by means of recursive construction methods.enAvailable to the World Wide WebDiscrete MathematicsUVic Subject Index::Sciences and Engineering::MathematicsThesis