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Performance evaluation of frequency division duplex (FDD) massive multiple input multiple output (MIMO) under different correlation models
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Massive multiple-input multiple-output (massive-MIMO) is considered as the key technology to meet the huge demands of data rates in the future wireless communications networks. However, for massive-MIMO systems to realize their maximum potential gain, sufficiently accurate downlink (DL) channel state information (CSI) with low overhead to meet the short coherence time (CT) is required. Therefore, this article aims to overcome the technical challenge of DL CSI estimation in a frequency-division-duplex (FDD) massive-MIMO with short CT considering five different physical correlation models. To this end, the statistical structure of the massive-MIMO channel, which is captured by the physical correlation is exploited to find sufficiently accurate DL CSI estimation. Specifically, to reduce the DL CSI estimation overhead, the training sequence is designed based on the eigenvectors of the transmit correlation matrix. To this end, the achievable sum rate (ASR) maximization and the mean square error (MSE) of CSI estimation with short CT are investigated using the proposed training sequence design. Furthermore, this article examines the effect of channel hardening in an FDD massive-MIMO system. The results demonstrate that in high correlation scenarios, a large loss in channel hardening is obtained. The results reveal that increasing the correlation level reduces the MSE but does not increase the ASR. However, exploiting the spatial correction structure is still very essential for the FDD massive-MIMO systems under limited CT. This finding holds for all the physical correlation models considered.

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Publication Date
Tue Jan 23 2018
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
ESTIMATION OF SOME CHEMICAL AND PHYSICAL PROPERTIES USING A WATER TREATMENT UNIT VORTISAND COMPARED TO THEIR CONCENTRATION IN WATER PRODUCED BY TRIDINTINAL DRINKING WATER PROJECTS IN BAGHDAD.: ESTIMATION OF SOME CHEMICAL AND PHYSICAL PROPERTIES USING A WATER TREATMENT UNIT VORTISAND COMPARED TO THEIR CONCENTRATION IN WATER PRODUCED BY TRIDINTINAL DRINKING WATER PROJECTS IN BAGHDAD.
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This study was conducted to determine the ability of water treatment system (Vortisand) to reduce some chemical and physical properties for tigris river raw water, It consisted of turbidity, electrical conductivity, pH, total hardness, calcium Hardness as well as temperature in order to determine the unit`s efficiency for reducing their concentration as compared to those in the water produced by some classical potable water projects (Dora and Wathba) in Baghdad. Samples were collected during the cold months (December 2016 and January 2017) and during the hot months (May and June 2017). The results showed that this system has the ability to reduce some properties such as turbidity, the values were 215NTU in raw water and decreased to NTU

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Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
the role of Green Human Resources Management Practices in strengthening the Strategic Positioning An Analytical Research on Leaders opinion in the Nongovernmental Hospitals in Erbil
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This research is seeks to state the role of Green Human Resources Management Practices and their dimensions (Green Employment and Selection, Green Performance Assessment, Green Training & Development and Green Compensation and Stimulation Systems) in strengthening the Strategic Positioning in the Nongovernmental Hospitals in Erbil city, and aims to analyze the relationship between Green Human Resources Management Practices and Strategic Positioning and to show the impact of Green Human Resources Management Practices in determining the Strategic Position.

            It is depended on a questionnaire as key tools for achieving data, as designed on

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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Nonlinear optical properties of polymer [PMMA] thin films doped with dye lasing compounds, Rhodamine 6G and Acriflavine in chloroform solvent by using dip coating method
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The fluorescence emission of Rhodamine 6G (R6G) and Acriflavine dyes in PMMA polymer have been studied by changing the irradiation and exposure time of laser light to know the effect of this parameter. It was found that the fluorescence intensity decreases in the polymer samples doped dyes as the exposure time increases and then reaches stabilization at long times, this behavior called photobleaching, which have been shown in liquid phase less than solid phase. Using 2nd harmonic with wavelength 530 nm laser, the photobleaching effect in the two dye-doped polymers different solvent but same was studied. It was observed that photobleaching of by different solution and by using dip spin coating the photobleaching seem in liquid phase more

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Publication Date
Wed Feb 28 2024
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn 2789-3219 )
The Effects of -806 T/C and -857 T/C Single Nucleotide Polymorphisms in the TNF-α Gene on Rheumatoid Arthritis Severity and Inflammatory Markers
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Background: Polymorphisms in the TNF-α gene affect the development and progression of rheumatoid arthritis. Objective: To investigate the associations between (-806 T/C) and (-857 T/C) SNPs with rheumatoid arthritis severity and susceptibility in a sample of Iraqi patients. Methods: A case-control study was conducted in Baghdad, Iraq. Twenty healthy controls and 63 patients confirmed to be newly diagnosed with rheumatoid arthritis were included. Those are divided into two groups (patients and controls), and the patients were further subdivided into severe and mild-moderate groups. Samples from those participants were analyzed for clinical and inflammatory parameter measurements. Genotyping by the Sanger method was performed to stu

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Publication Date
Wed Oct 02 2024
Journal Name
International Development Planning Review
THE EFFECT OF EXERCISES USING A MINI SQUASH COURT ON IMPROVING SOME MOTOR ABILITIES AND LEARNING SOME BASIC SKILLS FOR PLAYERS AGED 10-12 YEARS
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Publication Date
Sun Jun 30 2024
Journal Name
Modern Sport
The effect of an educational curriculum using virtual reality glasses in improving some kinetic abilities and learning freestyle swimming for first-year primary school students
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هدفت الدراسة الى الاهتمام واستغلال ماهو جديد من تقنيات واجهزة حديثة في تعليم السباحة الحرة عن طريق توجيه الاطفال على تطوير مداركهم واستيعابهم بالتطور التكنولوجي الذي يتناوله العالم ،قامت الباحثتان باعداد منهج تعليمي باستخدام نظارة الواقع الافتراضي وذالك بتوفير بيئة مشابهة للبيئة الحقيقية تحاكي مدارك عقول الاطفال في عالم افتراضي لتتكون صورة كاملة عن مهارات السباحة الحرة ،ومن هنا اتت المشكلة نتيجة تعل

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Publication Date
Wed Oct 02 2024
Journal Name
International Development Planning Review
THE EFFECT OF EXERCISES USING A MINI SQUASH COURT ON IMPROVING SOME MOTOR ABILITIES AND LEARNING SOME BASIC SKILLS FOR PLAYERS AGED 10-12 YEARS
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Publication Date
Wed Dec 14 2016
Journal Name
Journal Of Baghdad College Of Dentistry
Cell Surface Expression of 70 KDa Heat Shock Proteins and P21 in Normal Oral Mucosa, Oral Epithelial Dysplasia and Squamous Cell Carcinoma (An Immunohistochemical Study)
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Background: Oral SCC is a complex malignancy where environmental factors, viral infections and genetic alterations most likely interact, and thus give rise to the malignant condition. The HSP70 play a direct role in apoptosis inhibition by aligning the improved integrity of a cell’s proteins with the improved chances of that particular cell’s survival.P21 gene produces p21 protein which is a potent cyclin-dependent kinase inhibitor that plays a significant role in carcinogenesis. The aims of the study were to evaluate and compare the immun-histochemical expression of the HSP70 and cell cycle protein p21in NOM, OED, and OSCC. Correlate both marker expressions with each other. Materials and methods: Forty six formalin-fixed, par

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Publication Date
Wed Jun 29 2022
Journal Name
Journal Of The College Of Education For Women
The Chicago School in Urban Sociology: A Socio-Historical Approach on the Pragmatic Thought Influence as a Theoretical Frame of Reference in it-1892-2020
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The present theoretical study analyzes the legacy of the Chicago School of Urban Sociology and evaluates it in the light of the growth and development of Chicago City and the establishment of sociology in it. Sociology has become an academic discipline recognized in the United States of America in the late nineteenth century, particularly, after the establishment of the first department of sociology in the University of Chicago in 1892. That was during the period of the rapid industrialization and sustainable growth of the Chicago City. The Chicago School relied on Chicago City in particular, as one of the American cities that grew and expanded rapidly in the first two decades of the twentieth century. At the end of the nineteenth centur

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Publication Date
Fri Jun 30 2023
Journal Name
لارك
Expressions of probability in Spanish language and their translation into Arabic (Empirical study)تعابير الاحتمالية في اللغة الاسبانية و ترجمتها الى اللغة العربية: دراسة تطبيقية
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The probability is considered one of the grammatical cases in all languages of the world. Expressions of probability in Spanish language are expressed by various structures, expressions and some verb tenses. By this study explains the grammatical cases, the verbal periphrases, the impersonal expressions, the future tenses (simple and perfect) and the conditional mode of probability in Spanish language .We have explains these cases in detail with examples that have extracted from various spanish grammar books .The specific objective of this study is to know the resources and constructions of probability in Spanish language and their translation in Arabic language.

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