How do genetic algorithms relate to their biological ...biological origins? l Separation of genetic...
Transcript of How do genetic algorithms relate to their biological ...biological origins? l Separation of genetic...
MIT Design Inquiry
How do genetic algorithms relate to theirbiological origins?
How do they relate to human processes ofdesign?
Why is there power in this metaphor?
How can they be used to extend thecapabilities of the designer?
John GeroProfessor of Design Science
University of SydneyVisiting Professor of Design and Computation
MIT
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How do genetic algorithms relate to theirbiological origins?
l Separation of genetic material (genotype[representation]) from organism (phenotype[design])
l Expressing genotype as organisml Organism carries genotype and reproduces
genotype using ‘genetic’ processes of crossoverand mutation
l Darwin’s natural selection uses fitnesses oforganisms in their environment to improve the genepool
l GA is a simple model of this process
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Genetic processesGenetic processes
Crossover Points
A
C
B
D
Parents
Offspring
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A A B
B B C
A B C
B A B
Parents
Crossover point
Offspring
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A A B
B B C
A A C
B B B
Parents Offspring
Crossover point
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How do they relate to human processes ofdesign?
l Can map genetic representation onto acomputational representation of a design; can mapphenotype onto a interpretable view of a design
l Humans work on single or few designs at a time/genetics works on a population of ‘designs’ in parallel
l Humans can be seen to “search” design spaces - thisis one interpretation of what GAs are doing.
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Why is there power in this metaphor?
l Guaranteed improvement - Darwinianevolution
l Large scale searchl Blind searchl Fitness can be human evaluationl Fitness can change over evolutionary timel Can produce complexityl Can produce unexpected results
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How can they be used to extend the capabilitiesof the designer?
l Creativity through genetic engineering
l Novel designs through extending geneticcrossover
l Novel designs through different fitnesses
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Genetic Engineering and CreativeDesign
Genetic Engineering and CreativeDesign
l Background
l genes, genotype, phenotype, fitness
l Connecting genes to performance in fitness
l Emergent gene clusters ˛ evolved genes
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••
xx
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“bad”
“good”
“good” genotypes “bad” genotypes
Total Population
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a a brule 1 a ab
rule 2 aa
brule 3
a abrule 4 a rule 5 a rule 6
a ba
rule 7 ab
arule 8
ba
b
a
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design 1 design 2 design 3
design 4 design 5 design 6
design 7 design 8 design 9 design 10
{1,12,2,8,5,4,4,2,8,5,7}good
{1,2,1,8,2,8,5,5,6,6,8,1}good
{3,2,2,6,5,8,2,1,4,4,3,1}bad
{6,4,1,2,8,5,4,2,8,5,3,3}good
{3,4,8,2,8,1,6,5,7,3}bad
{2,3,2,3,4,3,5,6,5,1,6,2}neutral
{3,1,8,5,5,6,4,6,1,1,3,3}good
{1,6,4,2,7,3,4,8,6,1,6,2}bad
{6,4,1,2,3,4,5,2,1,7,4}neutral
{2,3,7,5,1,2,8,3,1,6,2,1}bad
Composite building block A{2,8,5}
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Mondrian
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Genotype Form
l In form of a tree
l Each node has four variables
l direction of rectangular split (4 values)
l fraction of the split (15 values)
l colour of split area (10 values)
l line width (3 values)
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Fitnesses for Representation
l offset between actual and required positions ofdissection lines
l number of lines with correct line width,normalised
l number of correct colour panels, normalised
l number of lines assigned, normalised
l number of unassigned lines, normalised
Genetically Engineered Mondrian
Genetically Engineered Mondrian
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Genetically Engineered Frank Lloyd Wright Windows
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Flondrians
l Mondrian painting ˛ genetically engineeredgenes: M-genes
l Frank Lloyd Wright windows ˛ geneticallyengineered genes in same representation: F-genes
l “Flondrians” are the genetic product of matingM-genes with F-genes
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How Many Designs Are There andWhere Are They?
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Genetic crossover as an interpolation
g1
g2
gcpc
p2
p1
Genotypic space GPhenotypic space P
C(g1,g2) Æ gcC(p1,p2) Æ pc
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P+
P
p1 p2
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Interpolation
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(interactive Genetic Art III)
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Image detection
(a) (b)
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Modelling Interest
Berlyne’s model of arousal based on novelty using Wundt curve
HE
DO
NIC
VA
LU
E
NOVELTYNx
Hx
Reward
Punish
0
1
-1
n1 n2
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Different novelty functions
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Different novelty preferences
N=0 N=1 N=2 N=3
N=4 N=5 N=6 N=7
N=8 N=9 N=10 N=11
N=12 N=13 N=14 N=15
N=16 N=17 N=18 N=19