GENE REORDERING AND CONCURRENCY IN GENETIC ALGORITHMS Şehitoğlu, Onur Tolga Ph.D., Department of Computer Engineering Supervisor: Assoc. Prof. Dr. Göktürk Uçoluk August 2002, 90 pages This study first introduces an order-free chromosome encoding to enhance the performance of genetic algorithms by learning the linkage of building blocks in non-binary encodings. The method introduces a measure called `affinity' which is based on the statistical properties of gene valuations in the population. It uses the affinity values of the local and global gene pairs to construct a global permutation with tight building block positioning. Method is tested and experimental results are shown for a group of deceptive and real life test problems. Then, study proposes a gene level concurrency model where each gene position is implemented on a different process. This combines the advantages of implicit parallelism and a chromosome structure free approach. It also helps implementation of gene reordering method introduced and probably other non-linear chromosome encodings. Keywords: genetic algorithms, concurrency, reordering, linkage learning, deceptive problem