Page 426 - Introduction to Information Optics
P. 426

7.8. Neural Pattern Recognition










                                   (a)




























                     (b)                                 (c)
       Fig. 7.46. (a) Input objects. Output correlation distributions (a) obtained from a WMF (a K — 0,05.
       « v = 0.05), and (b) using a CMF.


       7.8. NEURAL PATTERN RECOGNITION


         Strictly speaking, there are generally two kinds of neural networks (NNs),
       supervised and unsupervised. In supervised learning, a teacher is required to
       supply the NN with both input data and the desired output data, such as
       training exemplars (e.g., references). The network has to be taught when to
       learn and when to process information, but it cannot do both at the same time.
       In unsupervised learning, the NN is given input data but no desired output
       data; instead, after each trial or series of trials, it is given an evaluation rule
       that evaluates its performance. It can learn an unknown input during the
       process, and it presents more or less the nature of human self-learning ability.
   421   422   423   424   425   426   427   428   429   430   431