- INSTANCE:
An
*n*-node synchronous binary Hopfield network and a stable initial vector of states . A binary Hopfield network is a complete graph where each edge has an integer weight and each vertex has an integer threshold value . At each time step*t*each vertex has a state . is given by*u*and where is the sign function. An initial vector of states is stable if eventually converges for all*i*. - SOLUTION:
An initial vector of states
*v*that either converges to a different vector than*u*or is not stable. - MEASURE:
The Hamming distance between
*u*and*v*. If*v*is the vector nearest to*u*that does not converge to the same vector as*u*, then this distance is the attraction radius.

*Bad News:*Not approximable within for any [167].*Comment:*Transformation from MINIMUM INDEPENDENT DOMINATING SET.