2,016 research outputs found
Learning a spin glass: determining Hamiltonians from metastable states
We study the problem of determining the Hamiltonian of a fully connected
Ising Spin Glass of units from a set of measurements, whose sizes needs to
be bits. The student-teacher scenario, used to study learning
in feed-forward neural networks, is here extended to spin systems with
arbitrary couplings. The set of measurements consists of data about the local
minima of the rugged energy landscape. We compare simulations and analytical
approximations for the resulting learning curves obtained by using different
algorithms.Comment: 5 pages, 1 figure, to appear in Physica
Stability diagrams for bursting neurons modeled by three-variable maps
We study a simple map as a minimal model of excitable cells. The map has two
fast variables which mimic the behavior of class I neurons, undergoing a
sub-critical Hopf bifurcation. Adding a third slow variable allows the system
to present bursts and other interesting biological behaviors. Bifurcation lines
which locate the excitability region are obtained for different planes in
parameter space.Comment: 7 pages, 3 figures, accepted for publicatio
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