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Definition
Genetic Algorithms (GAs) are optimization functions that use an evolutionary
process to search through a space of alternative solutions to seek the optimal
solution.Unique Value
- Genetic Algorithms search large spaces of
alternative solutions efficiently
- GAs are "robust", meaning they are suitable
for a wide variety of problems because they make no assumptions about the
nature of the fitness "landscape"
- GAs deliver good solutions quickly in large
search spaces, but do not guarantee the optimal solution. This makes
them suitable for many applications where having a 99% solution now is better
than a 100% perfect solution someday.
Description
Solutions are encoded as strings
(chromosomes) of variables (genes) that have values (alleles). For
example, in the following graphic, the entire series is a chromosome, the
positions are genes and the "1" or "0" values are alleles. The entire
sequence represents an encoded solution, or "geneotype". When the genotype
chromosome is decoded it becomes a "phenotype", a physical solution to a problem.
The performance of this solution is evaluated. The performance measure is
called "fitness". The word "fitness" is based on how fit the solution is
to solve the problem.

"Generation-based" Genetic Algorithms
In "Generation-based" Genetic Algorithms, a population of alternative
chromosomes is
created with random values. These population members are decoded and their
performance is evaluated. Then using a performance-based selection scheme,
the attributes of the better solutions are combined in a mating or "crossover"
process. Next, they are randomly "mutated" to introduce some "jitter" to
explore the solution neighborhood.

The evaluation, selection/crossover, mutation
repeats until some stopping criteria is met. For example, one may stop
after a number of evaluations, or a number of cycles, or when a certain
performance has been found, or when a certain amount of time has been expended.
Continuous Genetic Algorithms
Continuous GAs do not have generations, but rather the population evolves on a
continual basis as the algorithms are called upon to provide alternative
solutions.

Like before, a random population is created, but
when a solution is called for by the calling application, two parents are
selected, mated and mutated and the child is returned. That child is
decoded and its fitness is evaluated. If the child meets a performance
criteria, it is allowed to return to the population. If not, it is
discarded. Typically the child is better than the criteria and the poorest
member of the population is dumped (to maintain population size) and the child
is allowed to enter. This is repeated while keeping the best solution
found until some stopping criteria is met.
BioComp's GA-CPG algorithms are a member of the
Continuous GA family.
The BioComp Advantage
There are a number of advantages in using GAs from BioComp:
- Nearly 20 years of research and development
that has eliminated issues and tuned algorithms for fast convergence to a
solution with few tuning parameters and insensitivity to settings.
- GA's that support constraints, limits and
solution desirability
- Simplified GA technology with greater
algorithm effectiveness and performance. GA searches can be run with as
little as four (4) API calls
- Scalable libraries are available that are
being used in multi-threaded multiple simultaneous optimizations for large
scale commercial applications
- Multiple-population optimization is supported
enabling simultaneous search of significantly different encoding and
convergence
- The technology is pre-embedded in useful
applications for common applications
- The technology is commercially supported
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