Even better Mastermind
-
Upload
juan-j-merelo -
Category
Technology
-
view
1.927 -
download
0
Transcript of Even better Mastermind
J. J. Merelo, Carlos Cotta, Antonio Mora
U. Granada & Málaga (Spain)
Http://geneura.wordpress.com
http://twitter.com/geneura
Optimizing worst-case scenario in evolutionary
solutions to the MasterMind puzzle
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 2
Game of MasterMind
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 3
7 reasons why you should care
Donald Knuth
NP-Complete
Differential cryptanalisis/ATM cracking
Circuit/program test
Genetic profiling
Optimal solution not known
Interesting search problem
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 4
Let's play, then
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 5
Consistent combinations
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 6
Naïve Algorithm
Repeat
Find a consistent combination and play it.
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 7
Looking for consistent solutions
Optimization algorithm based on distance to consistency (for all combinations played)
D = 2
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 8
Not all consistent combinations are born the same
There's at least one better than the others (the solution).
Some will reduce the remaining search space more.
But scoring them is an open issue.
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 9
What we did beforeWhat we did before
Apply heuristic methods to speed up finishing Apply heuristic methods to speed up finishing gamesgames
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 10
What we do now
Increase diversity in search via new operators and selection mechanisms
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 11
Objectives
Reduce the probability of takeover by a single individual
Reduce the possibility of repeated generation of a single combination
Increase speed to afford tackling bigger sizes
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 12
New tricks for old games
Add permutation operator
Add diff uniform crossover
crossover over different positions only
Selection makes sure parents are different
Change to tournament selection
Stronger selective pressure
Higher replacement rate
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 13
Results: number of evaluations
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 14
Results: any good at MasterMind?
Better
Bet
ter
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 15
Mission accomplished?
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 16
Worst case is better!
Measures to increase diversity have a positive impact on quality of algorithm and also speed
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 17
Open source your science!
Even B etter Evolutionary Mastermind - Merelo/Cotta/Mora 18
Thank you very much
Questions?