Continuous Hopfield Networks

In continuous Hopfield networks, the activation is no longer calculated by the binary threshold function but by the Fermi function with temperature parameters here, the network is stable for symmetric weight matrices with zeros on the diagonal, too. Hopfield also stated that continuous Hopfield networks can be applied to find acceptable solutions for the NP-hard travelling salesman problem. According to some verification trials this statement can’t be kept up any more. But today there are faster algorithms for handling this problem and therefore the Hopfield network is no longer used here.