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
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Enamel Protective Agent on Shear and Tensile Bond Strength of Stainless Steel Brackets by Using Different Adhesive Agents (In Vitro Study)
...Show More Authors

Background: Decalcification of surface enamel adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a wide spread and familiar well-known side effect of orthodontic treatment. The present study was carried out to evaluate the effect of enamel protective agent (Clinpro white varnish) on shear and tensile bond strength of Dentaurum orthodontic stainless steel brackets by using 3M Unitek and Ormco as orthodontic adhesive agents. Materials and methods: Sixty-four extracted human upper first premolar teeth were selected and randomly divided into two groups with 32 teeth each, representing the shear and tensile bond strength testing groups. Then according to the type of bonding adhesive and the addition of Clinpro before

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Oct 01 2022
Journal Name
Baghdad Science Journal
Using Pomegranate Peel Extract to Change the Adverse Effect of Ethephon by Enhancing its Antioxidant, Anti-inflammatory, and Anti-apoptotic Effects in Rats
...Show More Authors

Organophosphorus insecticide and growth regulator namely Ethephon (2-chloroethylphosphonic acid) are widely used as a ripening process accelerator and a cultivation duration inhibitor. Pomegranate extract (PPE) has recently been taken into consideration due to its pharmacological effects especially those associated with renal diseases. Thus, this study aims to investigate the possible protective effect of PPE against ethephon-induced nephrotoxicity in rats. In this study four groups of adult male rats were divided into control group, PPE 400 mg/kg group, Ethephon 250 mg/kg group, and finally, PPE + Ethephon group (treated with the same dose of PPE group and Ethephon group). In the current study, kidney function parameters (KIM-1, creatin

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Fri Nov 21 2025
Journal Name
Journal Of Baghdad College Of Dentistry
An Assessment of Sagittal Condylar Position of TMJ Dysfunction in Centric Occlusion by Using Cone Beam Computed Tomography
...Show More Authors

Background: Temporomandibular joint (TMJ) is a compound articulation formed from the articular surfaces of the temporal bone and the mandibular condyle.CBCT imaging of TMJ is that it allows accurate measurements of the volume and surface of the condyle. The aim of the study is to assess the sagittal position of mandibular condyle in patients with temporomandibulardysfunction using Cone Beam Computed Tomography in centric occlusion. Materials and Methods: CBCT images for all patients were obtained in an upright position using New Tom Giano CBCT with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors was changed accordingly using NNT version 5.1 software for sagittal reconstruction, anterior, superior and posterior

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Jan 30 2019
Journal Name
Journal Of The College Of Education For Women
The Impact of Applying Mind Mapping Technique as a Pre- Writing Tool on EFL College Students in Essay Writing
...Show More Authors

Based on the assumption that the more teachers know about brain science, the better
prepared they will be to make instructional decisions.
Mind Mapping is a powerful tool for assisting any form of writing. Language is an
important device and a very beneficial means for human being to communicate with other
people .Writing is one of the language skills that will never be left in education.
The study aims at investigating the Impact of applying mind mapping technique as a prewriting
tool on Iraqi EFL college students in essay writing. To do so, 60 EFL college students
were divided randomly selected and divided into two groups experimental and control. Prior
to treatment, participants of the both groups were given a

... Show More
View Publication Preview PDF
Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Radon concentration measurement in soil for some northen Iraqi's regions by using CR-39 detector
...Show More Authors

Concentrations of radon were measured in this study for twenty-four samples of soil distributed in six locations on the north part of Iraq. The radon concentrations in soil samples measured by using alpha-emitters registration that emits from Radon (222Rn) in (CR-39) track detector. The concentrations values were calculated by a comparison with standard samples. The results shows that the radon gas concentrations in Darbandikhan City varies from (16.60-34.04 Bq/m3), Halabja City (16.51-23.32 Bq/m3), Al Sulaimaniya City (17.61-32.25 Bq/m3), Koisnjaq City (22.04-35.65 Bq/m3), Shaqlaua City (21.10-29.10 Bq/m3) and Erbil City (22.30-34.63 Bq/m3). The average radon gas concentration in Al Sulaimaniya and Erbil governorate are (22.30 Bq/m3)

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 02 2023
Journal Name
Journal Of Pakistan Association Of Dermatologists
The frequency of acute radiodermatitis and associated risk factors among patients with breast cancer treated by radiotherapy
...Show More Authors

Background: Acute radiodermatitis is a common side effect during and after radiotherapy course in breast cancer patients treated by radiotherapy. This study assess the frequency of acute radiodermatitis and record the predictive factors for acute radiodermatitis. Patients and Methods: A descriptive case series study conducted at Baghdad, Iraq from August 2020 to September 2021. 70 female scheduled for radiotherapy sessions enrolled in this study. sociodemographic data were recorded and Skin examination before radiotherapy and weekly till the end of the radiotherapy sessions was done to report the frequency, risk factors, clinical picture and grades of acute radiodermatitis based on The National Cancer Institute’s Common Terminology Crite

... Show More
View Publication Preview PDF
Scopus
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Ridge regression method with some classical methods to estimate the parameters of Lomax distribution by simulation
...Show More Authors

Abstract

In this research provide theoretical aspects of one of the most important statistical distributions which it is Lomax, which has many applications in several areas, set of estimation methods was used(MLE,LSE,GWPM) and compare with (RRE) estimation method ,in order to find out best estimation method set of simulation experiment (36) with many replications  in order  to get mean square error and used it to make compare , simulation experiment  contrast with (estimation method, sample size ,value of location and shape parameter) results show that estimation method effected by simulation experiment factors and ability of using other estimation methods such as(Shrinkage, jackknif

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 03 2021
Journal Name
Key Engineering Materials
Study the Behavior of Castellated Steel Column Encasing by Different Reactive Powder Concrete Thickness with Laced Reinforcement
...Show More Authors

Castellated columns are structural members that are created by breaking a rolled column along the center-line by flame after that rejoining the equivalent halves by welding such that for better structural strength against axial loading, the total column depth is increased by around 50 percent. The implementation of these institutional members will also contribute to significant economies of material value. The main objectives of this study are to study the enhancement of the load-carrying capacity of castellated columns with encasement of the columns by Reactive Powder Concrete (RPC) and lacing reinforcement, and serviceability of the confined castellated columns. The Castellated columns with RPC and Lacing Reinforcement improve com

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Sun Oct 01 2017
Journal Name
Diyala Journal For Pure Science
Employing difference technique in some Liu estimators to semiparametric regression model
...Show More Authors

Semiparametric methods combined parametric methods and nonparametric methods ,it is important in most of studies which take in it's nature more progress in the procedure of accurate statistical analysis which aim getting estimators efficient, the partial linear regression model is considered the most popular type of semiparametric models, which consisted of parametric component and nonparametric component in order to estimate the parametric component that have certain properties depend on the assumptions concerning the parametric component, where the absence of assumptions, parametric component will have several problems for example multicollinearity means (explanatory variables are interrelated to each other) , To treat this problem we use

... Show More
View Publication
Crossref
Publication Date
Thu Jun 20 2019
Journal Name
Baghdad Science Journal
Social Worked-Examples Technique to Enhance Student Engagement in Program Visualization
...Show More Authors

Learning programming is among the top challenges in computer science education. A part of that, program visualization (PV) is used as a tool to overcome the high failure and drop-out rates in an introductory programming course. Nevertheless, there are rising concerns about the effectiveness of the existing PV tools following the mixed results derived from various studies. Student engagement is also considered a vital factor in building a successful PV, while it is also an important part of the learning process in general. Several techniques have been introduced to enhance PV engagement; however, student engagement with PV is still challenging. This paper employed three theories—constructivism, social constructivism and cognitive load t

... Show More
View Publication Preview PDF
Crossref (1)
Clarivate Crossref