The aim of this study to identify the impact of ownership’ structure criteria measured by
managerial ownership and ownership dispersion on corporate performance measured by
return on equity ROE, through sample contains of six Syrian private banks a
nd six Syrian
insurance companies for period between 2011 and 2016. The results showed that the
managerial ownership effects on performance, while ownership dispersion does not affect
on performance, as well as the relationship between these variables difference in term of
industry the company belongs to. To enhance the performance of Syrian corporation, some
recommendations have been presented by the end of study.
The aim of this study is to study the possibilities of obtaining materials with a material
shift to the higher wavelengths that fall within the C-Band window currently used in fiber
optic communication systems. This is done by mixing pure SiO2 with
different materials
and different percentages. We find the evidence of refraction of the core material in an
optical fiber and study the change of these clues by sequential wavelength of light from the
solimer constants obtained from the OptiFiber program. We then calculated the physical
dispersion factor DM for each of the studied materials by writing a special matlab program
for this study and thus studying the change in the physical dispersion of these materials by
the sequential wave length.
This research aims to study and design a single mode optical fiber using simulation,
with a core and glass cladding, and also helps in ensuring the efficiency to use the optical
fiber designed within the broading window C-Band,and that these resear
ches and studies
tries to use this window. This research also shares to set the light on the Numerical
Programmes and Simulation used now in studying and designing these optical fibers. At
first we used the programOptifiberto reach the confidence of Sellmeier equation for the
fiber core, and this completed by using the finite element method solving the equation of
propagation the electric field and finding its 3-D distribution, using the famous simulating
COMSOLMultiphysics. This completed by putting the program MATLAB to reach the
two equation: the total dispersion and attenuation for the designed optical fiber.
According to the method VMA Based on the direct
analysis of data related to total section functional angular
section, In order to access the parameters of optical
scattering Optimally which is based on the inner link between
the two parts (real – imaginary) Which is expressed through
Dispersion relation
Pulses suffer from changes in time and space when it propagates through matter, like
the positive Group Velocity Dispersion (GVD) which increases the pulse duration and
disperses its components ,this appears a2s a result of the second derivative of phase with
respect to frequency. We show in this article the possibility of a compensation way to
shorten the pulse duration based on negative GVD.
This research aims to check the actual performance of the work of the propeller
depending on series of results issued from Hamburg basins that are known by RANSE
where the arcs analysis and the hydrodynamic characteristics of the propeller work in
open
water are done by using the commercial program CFD Analysis m by Hydro Comp.
Thus, the results were compared with the experimental data and the study of fluently
around the different parts of the ship and the definition of resistance values and friction
factor CF. These values were compared with those issued by ITTC basins and coincidence
was found between those of RANSE and the experimental values in the different stages of
study.
Therefore, a collection of solutions related to the work of propeller were achieved in
addition to the evaluation of the level of interaction and the exchanged effect of the
propeller work in different conditions, and the definition of degree of difference resulted
from the values of the rotation moment and the factors of advance and control the are
resulted from the use of CFD program. The numerical results and the syntheses data were
discussed in case of working in open water.
Studying is showed that the amount of exchanging information in the network
surprisingly grows due to developing new communication services. But, when data rates
increase the optical system performance degrades due to dispersion, which was taken in
to
account in this research. Where as the reduction of dispersion losses is important in optical
networks. Fiber Bragg Grating (FBG) is one of the most important components of optical
communication systems, and one of the effective methods used for this goal.
This article tests the effect of using FBG as dispersion compensator in optical
communication systems, where we simulate optical communication system using FBG.
And study the effect of Erbium Doped Fiber Amplifier (EDFA) and FBG and fiber optic
parameters on this system performance, and it has been finding the best values of the
system parameters. Which the simulation model depended on two Optisystem7 and Matlab
software. We evaluate performance through eye diagram and two factors Q, Bit Error Rate
(BER).
Increasing data rate in optical communication systems leads to nonlinear electromagnet phenomenon in optical signal along fiber, and causes distortion in it.Thefiber dispersion is a linear phenomenon that causes difficulties toachieve high bit rate a
nd distance product.The limiting of nonlinear effects requireslow input power level, but this induces lowsignal to noise ratio. So, we search another solutions.
This paper studies Split Step Fourier Transform Algorithm (SSFTM) used to solve partial differential nonlinear Schrödinger equation (NLSE).Then, we use it for simulating optical signal propagating in fiber by using MATLAB program, and designing fiber optic block could add it to MATLAB Simulink Library. Finally ,in this paper, we achieved results for selecting important parameters in single mode fiber for high bit rate, for improving bit error rate and Qcoefficient.
The chromatic dispersion of fiber is a major factor
causing distortion of the light signals, and if not being
addressed using accurate compensators it will lead to a
significant deterioration in the performance of optical system.
The value of chr
omatic dispersion is not fixed along the fiber,
and this necessitates the use of tunable dispersion
compensators which need information about the value of
dispersion which is done by dispersion monitoring.
This research is Interested in analyzing chromatic
dispersion technique based on the measuring of clock tone
power of transmitted data and which is commensurate with
the dispersion of the fiber. We found the relationship between
signal frequency with range and accuracy of measurement.
Also, the advantage of this technique to provide feedback
signal to tunable dispersion compensator. The results show
the extent of the improvement made in network performance.
VPItransmissionmaker program was used to simulate
the technique proposed.
