EME: Emergence Module

1
EME Emergence Module

• Susan Stepney
• susan_at_cs.york.ac.uk
• Fiona Polack
• fiona_at_cs.york.ac.uk

2
What is an emergent system?

• Many simple elements, no central control
• Overall behaviour that is not an obvious
  consequence of behaviour of elements
• Construction by insects
• Crowd or flock behaviour by people, birds,
  insects
• Plants grown using simple growth algorithms
• Animals developed from simple cells

3
Why study emergent systems?

• Emergent systems cannot be understood by direct
  extension of conventional systems ideas
• An emergent system is a system of systems
• Emergent properties at system level
• Components at system level
• Emergence requires a change in scale
• Small systems combine to larger-scale effect
• This will not make sense if you are
  colour-blind or reading in b/w!

4
How can an emergent system be engineered?

• Through studying lots of emergent systems
• Well cover various sorts in EME
• By considering levels and the environment
• Polack and Stepney work on architectural aspects
  of emergent system development
• Through simulation and real-world observation
• What needs to be modelled to faithfully simulate
  emergence?
• Paying attention to dependability assurance

5
What will we look at?
6
CA demonstrate complex behaviour from simple
rules

• CAs

Time 1

• Game Of Life CAs
• http//www.math.com/students/wonders/life/life.htm
  l

• Langtons self-replicating loops
• http//necsi.org/postdocs/sayama/sdsr/java/

7
What will we look at?

• Demonstrations that complex behaviour emerges
  from multiple instances of simple systems
• L-systems
• Aristid Lindenmeyer Przemyslaw Prusinkiewicz
• biological metaphor plant branching growth
• eg. a bud becomes a twig, a twig gains buds,

8
What will we look at?

• Demonstrations that complex behaviour emerges
  from multiple instances of simple systems
• L-systems
• Aristid Lindenmeyer Przemyslaw Prusinkiewicz
• biological metaphor plant branching growth
• eg. a bud becomes a twig, a twig gains buds,
• a production replaces a parent module with a
  child module
• pn symbol ? rewrite_string
• bud ? twig p1 B ? T
• twig ? twig bud bud p2 T ? TBB

9
What will we look at?

• Demonstrations that complex behaviour emerges
  from multiple instances of simple systems
• L-systems
• Aristid Lindenmeyer Przemyslaw Prusinkiewicz
• biological metaphor plant branching growth
• eg. a bud becomes a twig, a twig gains buds,

Prusinkiewicz Lindenmeyer, fig 1.24a, c, d,
1.10, 1.24f, 1.8
10
What will we look at?

• Demonstrations that complex behaviour emerges
  from multiple instances of simple systems
• and various other artificial complex systems

11
What will we look at?

• Demonstrations that complex behaviour emerges
  from multiple instances of simple systems
• Nanotechnology
• molecular nanotech
• little things that make big things
• Nanobot constructors and replicators

Design for a fine-motion controller for molecular
assembly - 3000 atoms, lt1nm http//www.imm.org/
12
Engineering

• Not much work has been done on engineering
• Most artificial emergent systems are hacked
• Conways Game of Life CA was discovered by
  playing with patterns on a GO board
• Proposals for real-world nano-scale assemblers
  and disassemblers make engineering urgent
• Well look at
• Identifying and measuring emergence
• Layers in emergent systems
• Towards assurance-directed development frameworks