1,635 research outputs found
Emergence of chaotic attractor and anti-synchronization for two coupled monostable neurons
The dynamics of two coupled piece-wise linear one-dimensional monostable maps
is investigated. The single map is associated with Poincare section of the
FitzHugh-Nagumo neuron model. It is found that a diffusive coupling leads to
the appearance of chaotic attractor. The attractor exists in an invariant
region of phase space bounded by the manifolds of the saddle fixed point and
the saddle periodic point. The oscillations from the chaotic attractor have a
spike-burst shape with anti-phase synchronized spiking.Comment: To be published in CHAO
Dynamic image recognition in a spiking neuron network supplied by astrocytes
Mathematical model of spiking neuron network (SNN) supplied by astrocytes is
investigated. The astrocytes are specific type of brain cells which are not
electrically excitable but inducing chemical modulations of neuronal firing. We
analyzed how the astrocytes influence on images encoded in the form of dynamic
spiking pattern of the SNN. Serving at much slower time scale the astrocytic
network interacting with the spiking neurons can remarkably enhance the image
recognition quality. Spiking dynamics was affected by noise distorting the
information image. We demonstrated that the activation of astrocyte can
significantly suppress noise influence improving dynamic image representation
by the SNN.Comment: arXiv admin note: text overlap with arXiv:2210.0101
Diffraction radiation from a screen of finite conductivity
An exact solution has been found for the problem of diffraction radiation
appearing when a charged particle moves perpendicularly to a thin finite screen
having arbitrary conductivity and frequency dispersion. Expressions describing
the Diffraction and Cherenkov emission mechanisms have been obtained for the
spectral-angular forward and backward radiation densities.Comment: 6 pages, 4 figure
Non-language factors and language evolution
This paper is devoted to the description of the functioning and development of the language system seen in correlation with the influence of non-language factor
Astrocyte control bursting mode of spiking neuron network with memristor-implemented plasticity
A mathematical model of a spiking neuron network accompanied by astrocytes is
considered. The network is composed of excitatory and inhibitory neurons with
synaptic connections supplied by a memristor-based model of plasticity. Another
mechanism for changing the synaptic connections involves astrocytic regulations
using the concept of tripartite synapses. In the absence of memristor-based
plasticity, the connections between these neurons drive the network dynamics
into a burst mode, as observed in many experimental neurobiological studies
when investigating living networks in neuronal cultures. The memristive
plasticity implementing synaptic plasticity in inhibitory synapses results in a
shift in network dynamics towards an asynchronous mode. Next,it is found that
accounting for astrocytic regulation in glutamatergic excitatory synapses
enable the restoration of 'normal' burst dynamics. The conditions and
parameters of such astrocytic regulation's impact on burst dynamics
established
Dynamical diffraction in sinusoidal potentials: uniform approximations for Mathieu functions
Eigenvalues and eigenfunctions of Mathieu's equation are found in the short
wavelength limit using a uniform approximation (method of comparison with a
`known' equation having the same classical turning point structure) applied in
Fourier space. The uniform approximation used here relies upon the fact that by
passing into Fourier space the Mathieu equation can be mapped onto the simpler
problem of a double well potential. The resulting eigenfunctions (Bloch waves),
which are uniformly valid for all angles, are then used to describe the
semiclassical scattering of waves by potentials varying sinusoidally in one
direction. In such situations, for instance in the diffraction of atoms by
gratings made of light, it is common to make the Raman-Nath approximation which
ignores the motion of the atoms inside the grating. When using the
eigenfunctions no such approximation is made so that the dynamical diffraction
regime (long interaction time) can be explored.Comment: 36 pages, 16 figures. This updated version includes important
references to existing work on uniform approximations, such as Olver's method
applied to the modified Mathieu equation. It is emphasised that the paper
presented here pertains to Fourier space uniform approximation
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