Nevertheless it is important first to examine line
network where each element has only two intercon-
nections, Layer should be desintegrated into several
pieces or sets of neurons which can operate
independently.
Functions of connections between neurons in
linear parallel networks are significantly more rich
than in vertical ones.The main goal of this paper is
to show real possibility of application such neuron
networks for 2D optical signal treatment.
2.1 Functioning in general
Examination of human eye promises not only
clarification in idea of its layer structure but as
well enables to mark out several cells between
layers which bind certain other neurons into a
network whole. These specific cells are called
horizontal.They fulfil actions similar to ones of
springs between metal spheres.Each element of retina
recieves optical signals and if horizontal
interconnections are linear, then all information
will quickly be lost.Consequently, cells between
neurons should be considered as non linear elements.
The impetus for the investigations was a theory
of nonlinear lattices in accordance with which
whole network can be represented as a set of
oscillating elements.Specifical feature of this
structure is definition of external optical field,
influencing on network as potential, correspondig to
Toda or Korteveg-de-Vries equations at initial
moment. The profound theory of those systems one can
find in /2/, /3/.It is necessary to recall that in
the finite dimensional case the problem consists in
finding nxn matrices R and A, known as a Lax pair,
such, that equations of motion are equivalent to
the matrix equation
Sz [R,A]
where [..] - Lie brackets.
That this equation implies the eigenvalues of the
matrix R are conserved in time.It defines descrete
spectrum for corresponding well known Schrodinger
equation. Hence each new optical image has own
collection of spectral components.Single component
in its turn defines non linear stable wave- soliton.
Solitons move along network with different
velocities. Their complete characteristics are
amplitudes, location at network.Most interesting
parameter is phase shift between two solitons which
appears after their collisions.
2.2 Information processes in networks
From this starting point we will try to show
possibilities of networks with non linear
interconnections to analize information, containing
in the optical images.Imagine a linear lattice of
photodetectors with exponential links.The simplest
example of this links one can find in /4/.Determine
a moment of time when all detectors recieve
simultaneously signals.Then influence of them ceases
and picture of moving solitons begin to form.If
network is infinite, then there are descrete and
continuous spectrums.Continuous component is analog
of spectrum for linear network. Thus for every
neuronlike element its outpute is a solution of
Toda's equation
d'y ,4^-, onu. d
52 =e”""se 2e
where y is a normalized value of charge at the n-th
output (/5/).Define set Cyl.y2,. + 5 YTis » «VMS at
moment t=0 as an initial conditions.Let's find all
spectral components when quantity of neurons is
great enough to reproduce optical signal with
expecting acciracy. Values and locations of solitons
determine two Jost solutions (x), (x) which can
be found in accordance with oe
* ¢
039 6G) z ep (o -i J ote) (x) sin (e)
(1) = :
4) V 60 7 expCilon + Te) pe) emissa
These equations describe process of Wave
propagation trough potential
Kixzx’?) 2 y(x" )sinLk(-x?)]
In the theory of light scattering this function is
sometimes called transition function. Thus, solving
scattering problem for a wave, which propagates to
(exp(-ikx)) it is necessary to investigate influence
Of K(x,x") on t£ G0.K(x,x?) is defined by optical
image forming at the detector plane.We can achieve a
result, using Monte-Karlo method. Assume, that wave
propagates through plane parallel nonhomogeneous
media. The scattering properties are defined by
Kix,x"). Then express Y (x) as
(2) (xyk) = 2 b (Kk) |
where ho(x,k) = 1 and
K -ik(æ-x) ; /
' a / N
(S) e = "kie safe ach (e) d'e
This sum consists of components which can be
called components of i - order of scattering. This
property enables to classify all optical images from
the viewpoint of their discrete spectrum. Amplitudes
of each component of sum are different, but decrease
when i has tend to increase.If we substitute sum (2)
with finite series with imax-n then it is necessary
to choose n, specific for each signal.To achieve the
purpose of classification and analize extent of
correspondence between spectrum of signals and
collection of their discrete components numerical
experiment was made.As in the scattering theory we
can express K(x,x") in the form
?
- Ss (058) exp[-t(x,2)] (x)
O(x)2t lv-'*
where 6, , 6 - scattering and full cross sections, t -
optical length and g(cos 6) denotes the first
component (F11) of general transformation matrix by
Van de Hulst (/6/). © scattering angle. We discuss
only situation when k = in and
(4) Klx,x?)
Kix,x?) = te? Mh, i (^e - c.)
For linear network we consider only 6 = O.It should
be noted that solution of eq.1 can be found by two
ways.First supposes change @ (x) in accordance with
y{x), and the second change of g(cos © ).Sometimes
it is more convenient to define g(cos €) in every
point of network than G .Function M? (x) can be
found using well known weight method (/7/),averaging
> & LS Ms [ni 22]
where xn is determined by Monte-Karlo chain.
For this numerical experiment g(cos O ) was cal-
culated. It has been done for characterization of
real optical field with collection of parameters
which enables to obtain suitable illustrative
material and supplementary information for building
2 D network. To achieve this goal, the diffraction
task for spherical particles was solved. Gí(cos )
18