Transcript Chapter 1 Data Communications and Networks Overview

Publications
1- Prediction of Non Linear system in Optics Using
Genetic Programming, International Journal of
Modern Physics C, vol.18, No.3, pp. 369-374
(March 2007 ). This paper also published in the
31 international conference for statistics,
computer science and its application 2-6 April
2006.
2- Genetic Programming approach for electronalkali-metal atom collisions, International Journal
of Modern Physics B, vol.20, No.32, pp. 54635471 (December 2006 ).
3- Genetic Programming approach for flow of
steady state fluid between two eccentric spheres
, Appl. Rheol. 17:6 (2007) 68210
First : Applications of GA & GP in Optics
• Optical fiber is a dielectric transparent medium which
conducts and guides light and has many applications in
different fields (ex communications) due to its superior
optical properties.
• For example zero-dispersion wavelength is one of optical
properties of fiber. These optical properties are affected
by temperature.
• Variations of the optical properties of an optical fiber with
temperature are of optimum importance in many optical
and optoelectronic applications (why)
• Our aim to study the effect of room temperature on the
optical properties
First : Applications of GA & GP in Optics cont.
Two-term Sellmeier dispersion relation
had been adopted and fitted to the
experimental refractive index data in the
form
2
2
2
n ()  A  B (1  C /  )  D (1  E /  ) (1)
 is the wavelength measured in
micrometers. Here A, B, C, D, and E are
called the dispersion parameters of the
fiber core/cladding materials.
First : Applications of GA & GP in Optics cont.
• Nonlinear equation which can be solved
numerically by using a suitable
numerical calculation program.
• However, a set of parameter values A,
B, C and D, in many cases, will not be
uniquely determined (not agreed with
the previous experimental data).
• many different regions of parameter
space are investigated simultaneously.
• The results agree well with all previous
Authors’ works.
First : Applications of GA & GP in Optics cont.
n (, T )  ??
2
Introduction
First : Applications of g GA
& GP enetic programming in Optics
Experimental and predicted refractive index dispersion formula of the
core of fiber.
First : Applications of GA & GP in Optics
 In conclusion, GA succeeded to find solutions for
the variables in one equation that others methods
could not.
 The discovered function shows an excellent match
to the experimental data as well as,
the
predicting experimental data that are not used in
the training session.
 GP find a model that depend on two variables (,
T) not one variable as in the literature.
 Finally, we conclude that GP have become one of
important research area in the field of optics.
Second : Applications of GP in Atomic
•Alkali-metal atoms Li, Na, K, Rb and Cs atoms
have been a subject of interest in several
theoretical and experimental investigations in
electron-atom collisions because of their various
interesting applications
•The previous theoretical formula has an
error 21% with the experimental data.
•To find a function that fit the experimental
data and can predict others, We applied the
GP technique.
Second : Applications of GP in Atomic
Second : Applications of GP in Atomic
Second : Applications of GP in Atomic
In conclusion, the discovered functions (the
electron incident energy, atomic number and static
dipole polarizability) show a good match to the
experimental data. Moreover, the discovered
functions are capable of predicting experimental
data that are not used in the training session.
The previous theoretical formula has an error 21%
with the experimental data but the discovered
function has less than 10% which is acceptable
error in physics.
Finally, we conclude that GP have become one of
important research area in the field of atomic
physics.
Third : Applications of GP in fluid dynamics
•Fluids have some characteristics as viscosity
and elasticity.
•There are instruments measured viscosity
but for polymers that have the two
characteristics (viscosity & elasticity).
•It is difficult to measured both of them
simultaneously, a special techniques needed
•A new technique describes by the torque
and the forces acting on the external sphere
due to steady state motion of viscoelastic
fluid between two eccentric spheres.
Third : Applications of GP in fluid dynamics
Third : Applications of GP in fluid dynamics
Third : Applications of GP in fluid dynamics
In conclusion, GP discovered two functions
(for torque and forces ) that matched with
the experimental calculated and predicted
Data.
Moreover, the discovered functions are
capable of predicting experimental data that
are not used in the training session.
The two discovered functions are new in the
fluid dynamics to determent the viscosity and
elasticity simultaneously.