Information Technology Reference
In-Depth Information
further 2000 iterations. This shows a smooth transition in the number of tol-
erated antigen as
r
is increased. At large
r
, all antigens are tolerated by the
network. This is due to the fact that at extreme values of
r
, the recognition re-
gion covers this entire grid; thus every cell stimulates every other cell, resulting
in very large value of stimulation which cause any cell added to the network to be
suppressed. Antigen cells are tolerated as they are added at higher concentration
than antibody cells, therefore outlive any antibody cell that may potentially kill
them.
The right hand diagram of figure 4 shows results obtained using a bit-string
model using a complementary anity function. Surprisingly and in contrast with
the 2D shape-space, no antigens are tolerated by the network.
4
Why do the Models in Binary and 2D Shape-Space not
Concur?
The results in the previous section have shown that surprising results are ob-
tained when comparing a 2D shape-space to a bit-string shape-space. In an
attempt to explain this, we examine the distribution of the field received at
Fig. 6.
Field experienced by every potential bit-string in the bit-string space, following
emergence of the network, for four different anity thresholds.
