Neural networks - Signals, Processes, and Systems - page 454

0,30

Sprectra - multi file
each word 10 times

0,25

0,20

0,15

0,10

0,05

0,00

0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 3250 3500 3750

Y/t-Grafik 0

Hz

0, 15

Waterfall- display parameter
Selected parameters :
Start frequency 100 Hz Stop: 1600 Hz
Frequency interva: 100 Hz; distance 0 Hz
Maximum (instead of integral)

0, 11

0, 07

0, 04

0, 00

0. 00 0. 25 0. 50 0. 75 1. 00 1. 25 1. 50 1. 7

Y/t-Grafik 0

ms

Illustration 294: Visualization of the distinguishing features of the target values
The frequency- time- landscape in the above half of the picture shows clear spectral differences between
the several words. This already is an important indication considering the quality of the reference
material. The neuronal network nevertheless is fed with the parameters that can also be illustrated by a
waterfall display. Here also distinguishing features for all 5 words can be found.

The training material can be prepared by repeating every of the 5 words for example 10
times and this as altogether 50 spectra is used in a single *.ddf respectively *.nnd file. To
achieve this, a certain constellation is adjusted in the menu of the frequency parameter
module (e.g. start frequency 50Hz, frequency ratio 12 to 9, number of intervals: 8).

As soon as the *nnd file exists, the network training can begin. As result of the learning
process, the *.nn network file is available.