cooperative selection

Post on 23-Aug-2014

165 Views

Category:

Science

3 Downloads

Preview:

Click to see full reader

DESCRIPTION

This paper analyzes the dynamics of a new selection scheme based on altruistic cooperation between individuals. The scheme, which we refer to as cooperative selection, extends from tournament selection and imposes a stringent restriction on the mating chances of an individual during its lifespan: winning a tournament entails a depreciation of its fitness value. We show that altruism minimizes the loss of genetic diversity while increasing the selection frequency of the fittest individuals. An additional contribution of this paper is the formulation of a new combinatorial problem for maximizing the similarity of proteins based on their secondary structure. We conduct experiments on this problem in order to validate cooperative selection. The new selection scheme outperforms tournament selection for any setting of the parameters and is the best trade-off, maximizing genetic diversity and minimizing computational efforts.

TRANSCRIPT

Cooperative Selection: Improving Tournament Selection via Altruism

J.L.J. Laredo, S. Nielsen, G. Danoy,

P. Bouvry, C.M. Fernandes

University of Luxembourg, University of Lisbon

Scope

Cooperative Selection is an altruistic improvement of Tournament Selection…

…but, what´s wrong with Tournament Selection?

What is cool?

What is wrong ?

(Poli05) points outthe not-sampling and

the not-selection issues

What is wrong ?

Not-sampling

Population at generation xn individuals

What is wrong ?

Not-sampling

Population at generation xSampling 1

n individuals

Selection 1

What is wrong ?

Not-sampling

Population at generation xSampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

What is wrong ?

Not-sampling

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

What is wrong ?

Not-sampling

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

n x

n

What is wrong ?

Not-sampling

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

n x

n

Was sampled at all?

What is wrong ?

Not-sampling

Was sampled at all?

The answer is:might be not!

Good news: (Poli05) proposes a solution to the not-sampling issue

What is wrong ?

Not-selection

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

n x

n

What is wrong ?

Not-selection

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

Population at generation x

Population at generation x+1

Sampling 1

n individuals

Sampling 2

Selection 1

Selection 2Breeding

n x

n

Were they ever selected?

What is wrong ?

Not-selection

Were they ever selected?

The answer is also:might be not!

So far… there are no good news

Cooperative Selection

2 24 4 56 64 45 34 2 24 4 56 64 45 34

Tournament Selection Cooperative Selection

A B C D E F G A B C D E F G

2 24 4 56 64 45 34 2 24 4 56 64 45 34

Sampling Sampling

1st mate

Cooperative Selection

Tournament Selection Cooperative Selection

A B C D E F G A B C D E F G

2 24 4 56 64 45 34 2 24 4 56 64 45 34

64 64

Selection Selection

1st mate

Cooperative Selection

Tournament Selection Cooperative Selection

E E

A B C D E F G A B C D E F G

2 24 4 56 64 45 34 2 24 4 56 64 45 34

24+56

2=40

Selection Altruism

1st mate

Cooperative Selection

Tournament Selection Cooperative Selection

64 64

E E

A B C D E F G A B C D E F G

2 24 4 56 64 45 34 2 24 4 56 40 45 34

24+56

2=40

Selection Altruism

1st mate

Cooperative Selection

Tournament Selection Cooperative Selection

64 40

E E

A B C D E F G A B C D E F G

2 24 4 56 64 45 34 2 24 4 56 40 45 34

2nd mate

Cooperative Selection

Tournament Selection Cooperative Selection

Sampling Sampling

A B C D E F G A B C D E F G

64 40

E E

2 24 4 56 64 45 34 2 24 4 56 40 45 34

45

Selection Selection

2nd mate

64

Cooperative Selection

Tournament Selection Cooperative Selection

A B C D E F G A B C D E F G

64 40

E EE F

2 24 4 56 64 45 34 2 24 4 56 40 45 34

2nd mate

4+40

2=22

Cooperative Selection

Tournament Selection Cooperative Selection

45

Selection Altruism

64

A B C D E F G A B C D E F G

64 40

E EE F

2 24 4 56 64 45 34 2 24 4 56 40 22 34

2nd mate

4+40

2=22

Cooperative Selection

Tournament Selection Cooperative Selection

22

Selection Altruism

64

A B C D E F G A B C D E F G

64 40

E EE F

2 24 4 56 64 45 34 2 24 4 56 40 22 34

Cooperative Selection

Tournament Selection Cooperative Selection

22

Breeding

6464 40

E EE FBreeding

2 24 4 56 64 45 34 2 24 4 56 40 22 34

Cooperative Selection

Tournament Selection Cooperative Selection

22

Breeding

6464 40

E EE FBreeding

Cooperative Selection

2 24 4 56 64 45 34 2 24 4 56 40 22 34

Tournament Selection Cooperative Selection

22

Breeding

6464 40

E EE FBreeding

Cooperative Selection

2 24 4 56 64 45 34 2 24 4 56 40 22 34

Tournament Selection Cooperative Selection

22

Breeding

6464 40

E EE FBreeding

Thanks for your attention

top related