3. INTRODUCTION
Genetic Algorithm (GA) is a search-based
optimization technique based on the principles
of Genetics and Natural Selection. It is frequently
used to find optimal or near-optimal solutions to
difficult problems which otherwise would take a
lifetime to solve.
4.
5. What are genetic algorithm?
Nature has always been a great source of
inspiration to all mankind. Genetic Algorithms
(GAs) are search based algorithms based on
the concepts of natural selection and genetics.
GAs are a subset of a much larger branch of
computation.
6. Benefits of genetic algorithms
Easy to understand
Supports multi-objective optimisation
Good for noisy environment
We always get answer and answer gets better with time
Inherently parallel and easily distributed
Easy to exploit for precious or alternate solutions
Flexible in forming building blocks for hybrid
applications
Has substantial history and range of use
7. Basic genetic algorithms
Step1: Represent the problem variable domain as a chromosome of a fixed
length, choose the size of a chromosomes population N, the crossover
probability P, and the mutation probability Pm.
Step2: Define a fitness function to measure the performance, or fitness, of a
individual chromosome in the problem domain. The fitness function
establishes the basis for selecting chromosomes that will be mated during
reproduction.
Step3: Randomly generate an initial population of chromosomes of size
N: x1, x2, ……xN.
8. Step4: Calculate the fitness of each individual chromosome:
f(x1), f(x2), ……..f(xN)
Step5: Select a pair of chromosomes for mating from the current population.
Parent chromosomes are selected with a probability related to their fitness.
Step6: Create a pair of offspring chromosomes by applying the genetic operators –
crossover and mutation.
Step7: Place the created offspring chromosomes in the new population.
Step8: Repeat step5 until the size of the new chromosome population becomes
equal to the size of the initial population, N.
Step9: Replace the initial (parent) chromosomes population with the new (offspring)
population.
10. Basic operation of ga
Reproduction: It is usually the first operator applied on population. Chromosomes are selected
from the population of parents to cross over and produce offspring. It is based on Darwin’s
evolution theory of “Survival of the fittest”. Therefore, this operation is also known as
‘Selection Operation’.
Cross Over: After reproduction phase, population is enriched with better individuals. It makes
clones of good strings but doesn’t create new ones. Cross over operator is applied to the
mating pool with a hope that it would create better strings.
11. Mutation: After cross over, the strings are subjected to mutation. Mutation of
a involves flipping it, changing 0 to 1 and vice-versa.
12. APPLICATION OF GA
Travelling Salesman Problem
Artificial Life(A-Life)
Robotics
Automotive Design
Evolvable Hardware
Computer Gaming
Encryption and Code Breaking
Optimizing Chemical Kinetic Analysis
13. They are Robust.
Provide optimization over large space state.
Unlike traditional AI, they do not break on slight
change in input or presence of noise.
Why we use Genetic Algorithms
14. CONCLUSION:
Genetic Algorithms(Gas) are search based
algorithms based on the concepts of natural
selection and genetics. There is know better
algorithm than genetic algorithm.