2,240 research outputs found
Exploiting Environmental Computation in a Multi-Agent Model of Slime Mould
Very simple organisms, such as the single-celled amoeboid slime mould
Physarum polycephalum possess no neural tissue yet, despite this, are known to
exhibit complex biological and computational behaviour. Given such limited
resources, can environmental stimuli play a role in generating the complexity
of slime mould behaviour? We use a multi-agent collective model of slime mould
to explore a two-way mechanism where the collective behaviour is influenced by
simulated chemical concentration gradient fields and, in turn, this behaviour
alters the spatial pattern of the concentration gradients. This simple
mechanism yields complex behaviour amid the dynamically changing gradient
profiles and suggests how the apparently intelligent response of the slime
mould could possibly be due to outsourcing of computation to the environment.Comment: 2014 ABBII International Symposium on Artificial, Biological and
Bio-Inspired Intelligence, 27-28th September, Rhodes, Greec
Towards Physarum Binary Adders
Plasmodium of \emph{Physarum polycephalum} is a single cell visible by
unaided eye. The plasmodium's foraging behaviour is interpreted in terms of
computation. Input data is a configuration of nutrients, result of computation
is a network of plasmodium's cytoplasmic tubes spanning sources of nutrients.
Tsuda et al (2004) experimentally demonstrated that basic logical gates can be
implemented in foraging behaviour of the plasmodium. We simplify the original
designs of the gates and show --- in computer models --- that the plasmodium is
capable for computation of two-input two-output gate and
three-input two-output . We assemble the
gates in a binary one-bit adder and demonstrate validity of the design using
computer simulation.Comment: Biosystems (2010), in press. Please download final version of the
paper from the Publishers's sit
Road planning with slime mould: If Physarum built motorways it would route M6/M74 through Newcastle
Plasmodium of Physarum polycephalum is a single cell visible by unaided eye.
During its foraging behaviour the cell spans spatially distributed sources of
nutrients with a protoplasmic network. Geometrical structure of the
protoplasmic networks allows the plasmodium to optimize transfer of nutrients
between remote parts of its body, to distributively sense its environment, and
make a decentralized decision about further routes of migration. We consider
the ten most populated urban areas in United Kingdom and study what would be an
optimal layout of transport links between these urban areas from the
"plasmodium's point of view". We represent geographical locations of urban
areas by oat flakes, inoculate the plasmodium in Greater London area and
analyse the plasmodium's foraging behaviour. We simulate the behaviour of the
plasmodium using a particle collective which responds to the environmental
conditions to construct and minimise transport networks. Results of our scoping
experiments show that during its colonization of the experimental space the
plasmodium forms a protoplasmic network isomorphic to a network of major
motorways except the motorway linking England with Scotland. We also imitate
the reaction of transport network to disastrous events and show how the
transport network can be reconfigured during natural or artificial cataclysms.
The results of the present research lay a basis for future science of
bio-inspired urban and road planning.Comment: Submitted November (2009
Gauge Coupling Unification in MSSM + 5 Flavors
We investigate gauge coupling unification at 2-loops for theories with 5
extra vectorlike SU(5) fundamentals added to the MSSM. This is a borderline
case where unification is only predicted in certain regions of parameter space.
We establish a lower bound on the scale for the masses of the extra flavors, as
a function of the sparticle masses. Models far outside of the bound do not
predict unification at all (but may be compatible with unification), and models
outside but near the boundary cannot reliably claim to predict it with an
accuracy comparable to the MSSM prediction. Models inside the boundary can work
just as well as the MSSM.Comment: 28 pages, 13 figures. Added references, fixed minor typos. No changes
to content. Page count was incorrect in v1 Comment
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