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selected for a training antigen
ag
i
,
m
match
goes through a proliferation process (Prolif-
eration-I), known as
somatic hyper-mutation
that generates a number of clones of
m
match
. The exact number of clones is determined by three parameters, namely, (i)
hyper-mutation rate, (ii) clonal rate and (iii)
stim
(
ag
i
,
m
match
). Note that the first two
parameters are user-defined.
Each clone is produced through mutation (controlled by MUTATION_RATE, a
user defined parameter) at selected sites of
m
match
's feature matrix. No clone is an
exact copy of
m
match
. The algorithms for Proliferation-I and the generation of mutated
clones are outlined in Algorithm-I and II, respectively. These algorithms are similar to
the ones described in [6]. On completion of hyper-mutations, a stimulation value is
computed for each element
b
j
B
as
stim
(
b
j
,
ag
i
). Here
b
j
denotes an individual
b
-cell
clone and
B
represents the entire cloned population.
In order to minimize the computational cost in generating clones, a modified
version of the resource limitation policy [15] is incorporated. The modified version
considers only the recent clones generated for the current antigen undergoing the
(maturation) training process. The method does not consider clones generated for
previous antigens i.e. present implementation considered the entire resource for the
current antigen's class only.
Stopping criterion defined in equation (3) is used to terminate the training on an
antigen
ag
i
. If this criterion is not met then further proliferation of existing (i.e. sur-
vived after resource limitation)
b
-cells is invoked. In this stage (i.e. Proliferation-II),
each survived
b
-cell, i.e.
b
j
is proliferated to produce a number of clones determined
by the resources allocated to it. Proliferation-II process is similar to one for prolifera-
tion-I outlined in Algorithm-I except the calculation of the number clones to be gen-
erated from each surviving
b
-cell (
b
j
). This number is determined only by the
CLONAL_RATE and
stim
(
ag
i
,
b
j
).
∈
B
∑
=1
b
.
stim
j
(3)
j
> STIMULATION_THRESHOLD
B
Algorithm I
. Hyper-mutation/Proliferation-I
Let
B
is the set of
b
-cell clones to be created due to somatic hyper-mutation started
with
m
match
.
Initially
B
={
m
match
}.
Let
N
c
denote the number of clones and calculated as,
N
c
Å
HYPER_MUTATION_RATE * CLONAL_RATE *
stim
(
ag
i
,
m
i
)
While (|
B
|
≤
N
c
)
Do
mut
Å
false //
mut
is a Boolean variable
Call
mutate
(
m
i
,
mut
)
Let
b
j
denote a mutated clone of
m
i
If (
mut
) Then
B
Å
B
∪
b
j
Done
