CSC321 
Lecture 18: Hopfield nets and simulated annealing

Hopfield Nets

The energy function

Settling to an energy minimum

How to make use of this type of computation

Storing memories

Spurious minima

Avoiding spurious minima by unlearning

Willshaw nets

An iterative storage method

Another computational role for Hopfield nets

An example: Interpreting a line drawing

Noisy networks find better energy minima

Stochastic units

The annealing trade-off

How temperature affects transition probabilities

Thermal equilibrium

An analogy