Biomedical Engineering Reference
In-Depth Information
Conjugation region
C donor
C ' donor
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C recipient
C recipient
Before
After
Figure 3.6
Example.of.conjugation.
3.2.2.3  Transformation
Transformation. [52-54]. mimics. the. biological. capability. of. some. bacteria.
to.absorb.fragments.of.DNA.from.the.environment.and.then.to.reintegrate.
these.gene.segments.in.the.recipient.cells..An.example.is.shown.in . Figure 3.7 ..
A.chromosome.is.selected.from.the.mating.pool;.a.gene.segment.is.chosen.
from. the. gene. segment. pool.. The. segment. is. incorporated. in. the. chromo-
some. by. replacing. the. genes. after. a. randomly. generated. transformation.
point..In.each.generation,.the.old.population.contributes.part.of.the.new.seg-
ment.pool;.the.rest.is.created.randomly.
Transformation.is.designed.to.replace.crossover.in.the.GA.so.that.a.higher.
genetic.variation.is.provided..As.studied.[52,53],.a.better.solution.was.found.
for. several. highly. multimodal. test. functions. as. compared. with. the. use. of.
the. standard. GA.. This. was. mainly. because. this. new. genetic. operator. can.
better.preserve.the.diversity.in.the.population.of.an.evolutionary.algorithm..
Some.preferable.parameter.settings.for.transformation.have.been.suggested.
[55]..It.was.concluded.that.if.the.segment.size.increases,.the.results.worsen.
since. larger. segments. introduce. more. disruption. in. the. individuals. of. the.
population.
Transformation point
C 1
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C ' 1
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Gene segment
Before
After
Figure 3.7
Example.of.transformation.
 
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