Design and analysis of a nonequilibrium cross-coupled network with a detectable similarity measure

In this paper, a nonequilibrium network which works as a dynamical associat ive memory is designed. The design is based on a new similarity measure bet ween any stored pattern and a state of the network. Although conventional s imilarity measures, such as Hamming distance, direction cosine, and so on, are not detectable in a cross-coupled network, the similarity measure propo sed in this paper is. The new similarity measure is employed in our design, The network should include the following properties in its output pattern sequence, so that the dynamics of cross-coupled network mag be designed: 1) Stored patterns are frequently associated in the dynamical association. 2) The dynamical association is very robust against variation of distributed parameters, Property 1) is achieved by introducing the next two operation m odes with inverse N-shaped function into the dynamics of the proposed netwo rk. 1) When the state of the network is close enough to a stored pattern at a time step, the state is forced to evolve at the next time step, 2) The s tate of the network converges to a stored one while it is not close to any stored patterns, By considering these two operation modes, the frequency of associating stored patterns is increased, The authors emphasize the proper ty 2) which is very important for a silicon implementation of the proposed network, In the silicon implementation, parameters of the network must be r epresented by transistors, resistors, capacitors, and other electric compon ents which exhibit variation in their characteristics. Thus the second prop erty guarantees the easy silicon implementation of the nonequilibrium netwo rk proposed in this paper.