Preferred Language
Articles
/
joe-600
Compensation of the Nonlinear Power Amplifier by Using SCPWL Predistorter with Genetic Algorithm in OFDM technique
...Show More Authors

The High Power Amplifiers (HPAs), which are used in wireless communication, are distinctly characterized by nonlinear properties. The linearity of the HPA can be accomplished by retreating an HPA to put it in a linear region on account of power performance loss. Meanwhile the Orthogonal Frequency Division Multiplex signal is very rough. Therefore, it will be required a large undo to the linear action area that leads to a vital loss in power efficiency. Thereby, back-off is not a positive solution. A Simplicial Canonical Piecewise-Linear (SCPWL) model based digital predistorters are widely employed to compensating the nonlinear distortion that introduced by a HPA component in OFDM technology. In this paper, the genetic algorithm has been used to optimized the SCPWL coefficients by using Matlab 2015b, and then the Bit Error Rate (BER) performance has been evaluated for OFDM signal with 16-QAM and 64-QAM modulations in three cases, with nonlinear effects, without nonlinear effects (ideal case), with SCPWL and with nonlinear effects (compensated case)). The simulation results showed that the predistorter that adjusted by the genetic algorithm accomplishes huge execution change by successfully compensating the nonlinearity and reducing the input and output back-off (IBO, OBO) of the HPA.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Physics
Power dissipation and time of breakdown in AC discharge of argon at a low pressure in the frequency range 5-10 kHz
...Show More Authors

The influence of 5-10 kHz audio frequency on the power dissipation in ac discharge of argon gas was studied experimentally, at pressures 50-80 mTorr and electrodes separation 10 cm (pd range 0.5-0.8 Torr.
cm). The measurements have shown that the discharge behavior in the ac circuit is equivalent to a series RC circuit. It is observed that the variation curve of discharge power P with the frequency f is approximately has a Gaussian shape. It is also observed that the curve of Pm- pd is the inverse of Paschen curve, where Pm is the maximum power in the frequency range. The time of breakdown is estimated from the curve of P- f.

View Publication Preview PDF
Publication Date
Sun Dec 08 2019
Journal Name
Periodicals Of Engineering And Natural Sciences (pen)
Estimating total dissolved solids and total suspended solids in Mosul dam lake in situ and using remote sensing technique
...Show More Authors

View Publication
Scopus (12)
Crossref (8)
Scopus Crossref
Publication Date
Thu Aug 25 2016
Journal Name
International Journal Of Mathematics Trends And Technology
Pretest Single Stage Shrinkage Estimator for the Shape Parameter of the Power Function Distribution
...Show More Authors

View Publication
Crossref (1)
Crossref
Publication Date
Thu Nov 21 2013
Journal Name
المؤتمر العلمي الدولي الرابع لاتحاد الاحصائيين العرب / بغداد
Estimating Fertility Rates in Iraq by using (Lee-Carter) Model And Forecasting for the Period (2012_2031)
...Show More Authors

A large number of researchers had attempted to identify the pattern of the functional relationship between fertility from a side and economic and social characteristics of the population from another, with the strength of effect of each. So, this research aims to monitor and analyze changes in the level of fertility temporally and spatially in recent decades, in addition to estimating fertility levels in Iraq for the period (1977-2011) and then make forecasting to the level of fertility in Iraq at the national level (except for the Kurdistan region), and for the period of (2012-2031). To achieve this goal has been the use of the Lee-Carter model to estimate fertility rates and predictable as well. As this is the form often has been familiar

... Show More
Preview PDF
Publication Date
Thu Oct 01 2015
Journal Name
Al-academy
Power of language and carriers meaning in communication discourse: كاظم مؤنس عزيز
...Show More Authors

It reveals speech communication whether it is legible audible or visible on a comprehensive formula inhabited open language on the modalities for reporting cases of the source say, making communication cognitive processes, is not to produce arguments as it is about the generation of the content of communication, so the contact of any kind remains practice for the cognitive action by the language in which it operates as a way agreed to their units between the poles of communication circle in the framework of a certain socio-cultural context, and that becomes the basis of the text of the message external referrals, making it feasible for multiple readings in semantic dimensions and deliberative

 
... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Apr 01 2019
Journal Name
The Saudi Dental Journal
Implementation and characterization of coating pure titanium dental implant with sintered β-TCP by using Nd:YAG laser
...Show More Authors

Objectives This work presents laser coating of grade 1 pure titanium (Ti) dental implant surface with sintered biological apatite beta-tricalcium phosphate (β-TCP), which has a chemical composition close to bone. Materials and methods Pulsed Nd:YAG laser of single pulse capability up to 70 J/10 ms and pulse peak power of 8 kW was used to implement the task. Laser pulse peak power, pulse duration, repetition rate and scanning speed were modulated to achieve the most homogenous, cohesive and highly adherent coat layer. Scanning electron microscopy (SEM), energy dispersive X-ray microscopy (EDX), optical microscopy and nanoindentation analyses were conducted to characterise and evaluate the microstructure, phases, modulus of elasticity

... Show More
View Publication
Scopus (25)
Crossref (19)
Scopus Clarivate Crossref
Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Comparative study of the linear and nonlinear optical properties for different Iraqi heavy and light crude oils
...Show More Authors

Iraqi oil crudes have some of the physical and chemical characteristics that distinguish it from other types of oil crudes in the world. Some of these features such us molecular composition, rheological, viscosity and emulsions are studied carefully by researchers. In this work, a comparative study of the linear and the non-linear optical properties for typical heavy and light crude oils of Iraqi origin was studied utilizing Z-scan technique. The He -Ne laser of wavelength 632.8 nm had been used for this purpose. These samples were collected from Basra and Kut oil fields. The values of the non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order electrical susceptibility (χ3) were e

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use the Six Sigma technique in a solutionProblems of work (analytical study)
...Show More Authors

The research Concentrates on modern Variable in the organizations that is 6 sigma. The field study is two of Iraqi industrial organizations, The first is state company of …………… , the other is the state company of ……

The problem of the research determines some questions and hypotheses, The data was Collected by question air, which contains 5 dimensions and (10) critical Successful factories  . 

The sample contains (42) who Works in that organizations. The points out many conclusions. The main of it, there is significant differences among the two organizations Then The research concluded with a number of important recommendations serve it's objectives .

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Structural and optical properties of CdO and CdO0.99Cu0.01 thin films prepared by pulsed laser deposition technique
...Show More Authors

Structural and optical properties of CdO and CdO0.99Cu0.01 thin
films were prepared in this work. Cadmium Oxide (CdO) and
CdO0.99Cu0.01semiconducting films are deposited on glass substrates
by using pulsed laser deposition method (PLD) using SHG with Qswitched
Nd:YAG pulsed laser operation at 1064nm in 6x10-2 mbar
vacuum condition and frequency 6 Hz. CdO and CdO0.99Cu0.01 thin
films annealed at 550 C̊ for 12 min. The crystalline structure was
studied by X-ray diffraction (XRD) method and atomic force
microscope (AFM). It shows that the films are polycrystalline.
Optical properties of thin films were analyzed. The direct band gap
energy of CdO and CdO0.99Cu0.01 thin films were determined from
(αhυ)1/2 v

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees19gr
I-V characteristics of n-Si /ZnO/Se/MWCNTs nanocomposite solar cell fabricated by solvothermal technique
...Show More Authors

View Publication
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref