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Channel Estimation and Prediction Based Adaptive Wireless Communication Systems
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Wireless channels are typically much more noisy than wired links and subjected to fading due to multipath  propagation which result in ISI and hence high error rate. Adaptive modulation is a powerful technique to improve the tradeoff between spectral efficiency and Bit Error Rate (BER). In order to adjust the transmission rate, channel state information (CSI) is required at the transmitter side.

In this paper the performance enhancement of using linear prediction along with channel estimation to track the channel variations and adaptive modulation were examined. The simulation results shows that the channel estimation is sufficient for low Doppler frequency shifts (<30 Hz), while channel prediction is much more suited at high Doppler shifts with same SNR and target BER=10-4. It was shown that the performance at higher Doppler frequency shifts (<30Hz) was improved by more than 2dB over channel estimation at target BER=10-4 and 32QAM constellation used.

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
Studying the effect of annealing on some electrical and optical properties for thin CdS , CdS:In films
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In the present work we prepared heterojunction not homogenous CdS/:In/Cu2S) by spray and displacement methods on glass substrate , CdS:In films prepared by different impurities constration. Cu2S prepared by chemical displacement method to improve the junction properties , structural and optical properties of the deposited films was achieved . The study shows that the film polycrystalline by XRD result for all film and the energy gap was direct to 2.38 eV with no effect on this value by impurities at this constration .

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Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
The Theory of Vital Space - Theoretical Study of Geopolitical Dimensions, Targets and Means (USA) Case Study
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The concept of forming the living space in the American strategic thought has an
important position it is regarded as an strategic movement that it supports the American
United States with the huge capabilities in its own concern that enables it to approach of
American administration , we find that of different historical periods it works to establish that
the geopolitical dimension which is accompanied with the ability of American response for
the evens that in its own turn enables the American united states to seize the growing chances
in the global strategic environment This study includes five chapters :
- Chapter one: The idea of living space.
- Chapter two: Geopolitical dimension of living space theory.
-

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Publication Date
Tue Aug 15 2023
Journal Name
Al-academy
Formal questioning and its representations in the design of contemporary residential rooms for children with autism
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The formal investigation of the interior spaces of the residential bedrooms for children with autism is one of the basic tasks that should be known by the interior designer. Achieving an atmosphere compatible with his health condition, which contributes to generating a sense of spatial intimacy through the design dimension provided by the interior designer and his tireless endeavor to meet the needs of the child in an internal environment that achieves the functional dimension and spiritual approaches that enhance the child’s sense of spatial belonging and contribute to improving his mood and this positively reflects on his behavior and social integration. The current research has reached the most important design criteria that must be

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Publication Date
Fri Jul 24 2020
Journal Name
Al-kindy College Medical Journal
Irritable Bowel Syndrome: The Most Common Presentation, Severity Ranking and Therapeutic Regimens among Patients Attending Outpatient
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Background: Irritable bowel syndrome (IBS) is one of the most common GI disorders in people under 50 years of age.
Objective: To Formulate an overview about demographics of IBS and patterns of presentation, to determine IBS patients severity ranking, and to recognize the main regimens with their patient satisfaction.
Methods: This is a cross sectional clinical study that is conducted in Outpatient Consultant Internal Medicine Clinic in Al-Kindy Teaching Hospital from 11/12/2017 to 24/12/2017. The patients suffering from IBS are diagnosed by a consultant according to the symptom-based Rome criteria for functional GI disorders, by implementing a questionnaire collecting thorough information. 77 cases of IBS patients were collected (2

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Relevance of Budgeting Estimations for Control and Performance Evaluation in Adopting Kaizen: Hypothetical & Empirical Study
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The kaizen is considered as one of the most important modern techniques which has been adopted by various economics entities especially manufacturing firms and its beginnings return to the middle of the earlier century that has been used by companies like Toshiba, Matsushita Electric, and Toyota. Which realized that these modern techniques would make a total change in the competitive environment and started qualifying and its staff in such away that enables them to go along with this unique environment. The continuous improvement (Kaizen) depends on the small continuous improvements in the product and the production operations during the production stage. Consequently, the research problem is represented in the improperly of the budg

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Laser-Induced Modification of Ag and Cu Metal Nanoparticles Formed by Exploding Wire Technique in Liquid
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This research aims to find a method to synthesize nanoparticles of important metals in the fields of medicine and electronics, with high purity small in size and narrow size distribution. And it characterized by simplicity, efficiency and high productivity. To achieve this aim the effects of laser irradiation on silver and copper colloids prepared by exploding wire technique in double distilled and deionized water (DDDW) have been studied. The laser irradiation was performed using laser radiation fluence about 4 J/cm2 at 532 nm wavelength. Additional irradiation of colloids resulted in the changes of particles morphology, which were monitored by absorption spectroscopy and transmission electron microscopy methods. It was found that both

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Publication Date
Sun Sep 07 2008
Journal Name
Baghdad Science Journal
Study the effect of thickness and annealing temperature on the Electrical Properties of CdTe thin Films
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The electrical properties of polycrystalline cadmium telluride thin films of different thickness (200,300,400)nm deposited by thermal evaporation onto glass substrates at room temperature and treated at different annealing temperature (373, 423, 473) K are reported. Conductivity measurements have been showed that the conductivity increases from 5.69X10-5 to 0.0011, 0.0001 (?.cm)-1 when the film thickness and annealing temperature increase respectively. This increasing in ?d.c due to increasing the carrier concentration which result from the excess free Te in these films.

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Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Compound Heat Transfer Enhancement in Dimpled and Sinusoidal Metal Solar Wall Ducts Fitted with Wired Inserts
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An improved Metal Solar Wall (MSW) with integrated thermal energy storage is presented in this research. The proposed MSW makes use of two, combined, enhanced heat transfer methods. One of the methods is characterized by filling the tested ducts with a commercially available copper Wired Inserts (WI), while the other one uses dimpled or sinusoidal shaped duct walls instead of plane walls. Ducts having square or semi-circular cross sectional areas are tested in this work.
A developed numerical model for simulating the transported thermal energy in MSW is solved by finite difference method. The model is described by system of three governing energy equations. An experimental test rig has been built and six new duct configurations have b

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Publication Date
Wed Mar 16 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Cognitive Behavioral Program in Reducing Stuttering and Social Anxiety among High-School Students
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The current study aims to assess the effectiveness of the cognitive-behavioral programs in reducing stuttering and social anxiety among high-school students. The researchers used the experimental design. The sample consists of (20) male students who reported the highest score on the stuttering severity scale and social anxiety scale. The sample was divided into experimental and control groups (each group consists of 10 participants). The researcher used the type and severity of stuttering scale developed by Onslow et al (2003), translated by Mahmoud Ismail and the social anxiety scale was prepared by the authors. The results showed that there are statistically significant differences in pre-post and follow-up tests amongst the experiment

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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Spectrophotometric Study for Charge Transfer Complexes Between p- Chloranil with Anions of Amide, Azide and Cyanide
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    The complexes of para-chloranil as electron acceptor and the anions of amide, azide and cyanide as electron donors in aqueous ethanol as a solvent, were studied spectrophotometrically .     The reactions lead to the formation of charge transfer complexes. The CT complexes were stable in excess acceptor concentration, while they were underwent another transformations in excess donors concentrations.   Stoichiometries were determined, the molecular ratio was determined by continuous variation method (Job method) and is was  1:1 (donor: acceptor).   The maximum wavelength (λ max.), the energy (hÏ…CT), ionization potential (Ip) and activation energy (w ) of excited state f

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