Information Technology Reference
In-Depth Information
Parent solutions
Child solutions
Genic recombination
Synapsis
Shuffling
Figure 3.10
A conceptual view of uniform crossover. Genes are shown as rectangles.
Shade indicates functionality.
group of genes from one parent to another or by removing a contiguous group of
genes from a parent (Figure 3.11). Each of these operations is applied in 50% of
recombination events. In subtree crossover, one subtree is always replaced by
another. Using TR recombination, components being added and components be-
ing removed from a program are independent events, and therefore they are less
disruptive than using subtree or uniform crossover. Furthermore, the compo-
nents (apart from receptors) transferred to a program will only become involved
in the program's execution if they fulfill the interaction preferences of existing
components. Consequently, new components will only replace existing compo-
nents if they fulfill these preferences better than the components they replace.
The mutation operator of enzyme GP targets both activities and specificities.
An activity mutation replaces the current activity with one chosen randomly
Parent
Donor
Child
Figure 3.11
Recombination using transfer and remove. Note that the number of
receptors in a genotype is fixed, so any receptors transferred from the donor replace
those copied from the parent.
