The properties of time series generated by a perceptron with monotonic and
non-monotonic transfer function, where the next input vector is determined
from past output values, are examined. The analysis of the parameter space
reveals the: following main finding: a perceptron with a monotonic function
can produce fragile chaos only, whereas a non-monotonic function can gener
ate robust chaos as well. Fur non-monotonic functions, the dimension of the
attractor can be controlled monotonically by tuning a natural parameter in
the model.