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Compensation of the Nonlinear Power Amplifier by Using SCPWL Predistorter with Genetic Algorithm in OFDM technique
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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.

 

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Publication Date
Mon Mar 01 2010
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Mechanical Combined Contact Stress with Buckling Load on the Stress Distribution in the Ball and Socket Joint Mechanism
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The design of components subjected to contact stress as local compressive stress is important in engineering application especially in ball and socket Joining.  Two kinds of contact stress are introduced in the ball and socket joint, the first is from normal contact while the other is from sliding contact. Although joining two long links (drive shaft in steering cars) will cause the effect of flexural and tensional buckling stress in hollow columns through the ball and socket ends on the failure condition of the joining mechanism. In this paper the consideration of the combined effect of buckling Load and contact stress on the ball and socket joints have been taken, epically on the stress distribution in the contact area. Different

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Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Extension of the Chebyshev Method of Quassi-Linear Parabolic P.D.E.S With Mixed Boundary Conditions
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The researcher [1-10] proposed a method for computing the numerical solution to quasi-linear parabolic p.d.e.s using a Chebyshev method. The purpose of this paper is to extend the method to problems with mixed boundary conditions. An error analysis for the linear problem is given and a global element Chebyshev method is described. A comparison of various chebyshev methods is made by applying them to two-point eigenproblems. It is shown by analysis and numerical examples that the approach used to derive the generalized Chebyshev method is comparable, in terms of the accuracy obtained, with existing Chebyshev methods.

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Publication Date
Fri Feb 02 2018
Journal Name
International Journal Of Science And Research (ijsr)
The Compressibility of Clayey Soils Reinforced with Fiberglass
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During the prior three decades numerous research works presented to investigate the behavior of reinforced soil. A, IJSR, Call for Papers, Online Journal

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Publication Date
Sun Sep 15 2024
Journal Name
Iraqi Journal Of Pharmaceutical Sciences( P-issn 1683 - 3597 E-issn 2521 - 3512)
Olanzapine-induced Metabolic Syndrome and its Association with -759C>T Polymorphism of the HTR2C Gene in Iraqi Schizophrenic Patients
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The hazardous metabolic effects of treating schizophrenia patients with olanzapine comprise serotonin 2C receptor (5-HT2C) antagonists. Metabolic side effects of antipsychotic drugs, including lipid abnormalities, disturbed glucose metabolism, and weight gain, can have a major impact on treating psychiatric patients. The intent of this study was to investigate whether there is an associated link between the genetic polymorphism at -759C>T in the promoter region of the 5-hydroxytryptamine 2C receptor (HTR2C) gene and the metabolic syndrome driven by olanzapine in schizophrenia patients. A cross-sectional study that involved fifty hospitalized patients with schizophrenia. The patients were split into two groups (metabolic and non-metab

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Publication Date
Fri Oct 02 2015
Journal Name
American Journal Of Applied Sciences
Advances in Document Clustering with Evolutionary-Based Algorithms
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Document clustering is the process of organizing a particular electronic corpus of documents into subgroups of similar text features. Formerly, a number of conventional algorithms had been applied to perform document clustering. There are current endeavors to enhance clustering performance by employing evolutionary algorithms. Thus, such endeavors became an emerging topic gaining more attention in recent years. The aim of this paper is to present an up-to-date and self-contained review fully devoted to document clustering via evolutionary algorithms. It firstly provides a comprehensive inspection to the document clustering model revealing its various components with its related concepts. Then it shows and analyzes the principle research wor

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Publication Date
Mon Sep 03 2018
Journal Name
Al-academy
Educational Novelty And Its Relation With Visual Thinking With The Students Of Artistic Education Department
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The two objectives of the current research are :-

  1. Uncover the views and opinions of the students of Artistic Education Department about the relation between educational novelty and its relation with visual . 
  2. Identifying the capabilities of the students of artistic education department .

            The society of the research is the  fourth class students of artistic education department -  College of Fine Arts  ( 83 students from both sexes ) .  It was chosen ( 60 ) students sample of  from both sexes by the researcher in order to conduct test upon them .The researcher has adopted descr

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Publication Date
Thu Apr 01 2021
Journal Name
Annals Of The Romanian Society For Cell Biology
Rehabilitation exercises accompanying ultrasound in the rehabilitation of the elbow joint for patients with tendinitis, aged (30-40) men
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The elbow joint is one of the important and mobile joints in a way that allows it to perform its functions. The injury occurs when the joint tendon and arm muscles are subjected to repeated partial ruptures as a result of excessive and repetitive work, as well as the patient not being subjected to correct rehabilitation programs, and only rest. From here, the researchers decided to study this problem by preparing rehabilitation exercises accompanying ultrasound and assessing their impact on the rehabilitation of the elbow joint. The sample included male patients aged 30-40 years, and the tests were determined, which included testing the range of motion of the elbow joint from the flexion position and the rotation outward position, the mu

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Publication Date
Sun Apr 07 2013
Journal Name
Journal Of Educational And Psychological Researches
skills and its relationship to the with concept of self in social The chidren kindergarten age (4-6) years
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 The interest in Multi social skills and self-concept is extremely  important for many of the scholars of education and psychology has taken a great deal in their writings and their interests as they see that social skills training is to make sure of the same, and that whenever enable the individual from acquiring social skills whenever asserted itself.The research aims know social skills and self-concept and their relationship to the children Riyadh age (4-6 years), and the research sample consisted of(200) boys and girls from kindergarten in the city of Baghdad Bjanbey Rusafa second and Karkh second.And to the objectives of the research realized the researcher has built two measures of social skills a

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Publication Date
Sat Dec 01 2018
Journal Name
Political Sciences Journal
The Patterns of the Strategic Environment and its Role in Determining Strategies for Dealing with Conflict and Peace Situations
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Abstract

The decision maker needs to understand the strategic environment to be addressed through different means and methods. It is obvious that there is a difference between the three strategic environments (conflict environment, peace environment, post- peace environment) in terms of inputs and strategies to deal with each one of them. There is an urgent need to understand each pattern separately, analyze its inputs, and identify the factors and variables that affect the continuity of this situation (conflict, peace, post-peace). It is not appropriate to identify treatment without diagnosis of the condition, so it is very important to understand the type of strategic environment to be dealt with it.

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Publication Date
Sat Dec 01 2018
Journal Name
Acta Facultatis Medicae Naissensis
The Factors Influencing the Risk of Perforation in Patients with Peptic Ulcers: A Cross-Sectional Study from Central Iraq
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Abstract<p>The aim of this study was to evaluate the risk factors that influence the perforation, regardless of the presence of H. pylori infection, in a sample of Iraqi patients with peptic ulcers, admitted to Al-Kindy Teaching Hospital. A total of 90 patients who had perforated peptic ulcer participated in this study. The diagnosis was based on history, clinical examination, laboratory and radiological investigations and was confirmed intraoperatively. A number of probable risk factors for perforation were investigated. Eighty participants were males and 10 were females (male to female ratio 8:1). About 42.2% of patients were in their fifth decade of life. Forty-nine (54.4%) patients were asymptomatic be</p> ... Show More
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