The effects of vector concatenation as well as of eliminating the zero diagonal restriction of associative memory neural network matrices are analyzed. Extensive computer simulations seem to indicate that the use of concatenated vectors increases the storage capacity of the association matrices.
B. H. Soffer,
"Associative Memory Neural Networks With Concatenated Vectors", Proc. SPIE 0963, Optical Computing '88, (8 February 1988); doi: 10.1117/12.947935; https://doi.org/10.1117/12.947935