stagnation recovery with the method of task modeling. The collective behavior of
their system appears to be very similar to that of real ants.
1.3.AMORPHOUS COMPUTING
Amorphous computing represents an analog approach to swarm system design.
In amorphous computing systems, a colony of cells cooperates to form a multicellular organism under the direction of a program (loosely called a genetic program)
that is shared by all members of the colony.
The objective of amorphous computing is the creation of algorithms and techniques
for the understanding of programming materials. Essentially, amorphous computing
seems to incorporate the biological mechanisms of individual cells into systems that
exhibit the expressive power of digital logic circuits. Stigmergy in such systems can
be either marker-based or sematectonic and be either scalar or vector in extent. An
amorphous computing medium is a system of irregularly placed, asynchronous,
locally interacting computing elements. The medium is modelled as a collection of
“computational particles” sprinkled irregularly on a surface or mixed throughout a
volume. In essence, the computational assembly forms an ad hoc network.
Research into self-healing structures, circuit formation, programmable self-assembly
and selforganizing communication networks are a small sample of the work
undertaken.
1.4. EVALUATION OF SWARM INTELLIGENT SYSTEM
Although many studies on swarm intelligence have been presented, there are no
general criteria to evaluate a swarm intelligent system's performance. They
proposed measures of fault tolerance and local superiority as indices. They compared
two swarm intelligent systems via simulation with respect to these two indices. There
is a significant need for more analytical studies.
1.4.1 STABILITY OF SWARMS
1.4.1.1 BIOLOGICAL MODELS
In biology, researchers proposed “continuum models" for swarm behavior based on
nonlocal interactions. The model consists of integro-differential advection-diffusion