Preferred Language
Articles
/
hRb3BIcBVTCNdQwCuy3S
Performance evaluation of frequency division duplex (FDD) massive multiple input multiple output (MIMO) under different correlation models
...Show More Authors

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.

Scopus Clarivate Crossref
View Publication
Publication Date
Fri Jan 01 2021
Journal Name
Latin American Journal Of Solids And Structures
Structural Behavior of Reinforced Hybrid Concrete Columns under Biaxial Loading
...Show More Authors

View Publication
Crossref (15)
Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Buckling Analysis of Composite Plates under Thermal and Mechanical Loading
...Show More Authors

Buckling analysis of composite laminates for critical thermal (uniform and linear) and mechanical loads is reported here. The objective of this work is to carry out theoretical investigation of buckling analysis of composite plates under thermomechanical loads, and experimental investigation under mechanical loads. The analytical investigation involved certain mathematical preliminaries, a study of equations of orthotropic elasticity for classical laminated plate theory (CLPT), higher order shear deformation plate theory (HSDT) , and numerical analysis (Finite element method), then the equation of motion are derived and solved using Navier method and Levy method for symmetric and anti-symmetric cross-ply and angle-ply laminated plates t

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Formulation of Multi-Purpose Grease for Use under Severe Conditions
...Show More Authors

View Publication Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Latin American Journal Of Solids And Structures
Structural Behavior of Reinforced Hybrid Concrete Columns under Biaxial Loading
...Show More Authors

Scopus (17)
Crossref (16)
Scopus Clarivate Crossref
Publication Date
Tue Mar 03 2020
Journal Name
Molecular Biology Reports
Correlation of GSTP1 gene variants of male Iraqi waterpipe (Hookah) tobacco smokers and the risk of lung cancer
...Show More Authors

Glutathione-S-transferases (GSTs) play a role in the detoxification of environmental chemicals and mutagens, such as those inhaled during tobacco smoking. There have been conflicting reports concerning GST polymorphisms as risk factors in the development of lung cancer. No studies focused on Arab populations exposed to Waterpipe (WP) tobacco smoke have been undertaken. Here Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and gene sequenc- ing were applied to analyze allelic variations in GSTP1-rs1695 and -rs1138272 amongst 123 lung cancer patients and 129 controls. The data suggest that WP smoking raised the risk of lung cancer more than three-fold (OR 3.6; 95% CI 2.1–6.0; p < 0.0001). However, there was no s

... Show More
View Publication Preview PDF
Scopus (15)
Crossref (12)
Scopus Clarivate Crossref
Publication Date
Sat Jul 01 2017
Journal Name
Global Journal Of Bio-science And Biotechnology
Efficiency of different denture disinfection methods
...Show More Authors

Dentures that are not cleaning and maintained properly may prone to contamination by different microbial pathogens that result in several oral conditions. This study was design to compare the antimicrobial effect of different denture cleansers oxalic, tartaric, citric acids and alkaline peroxide with microwave irradiation on the growth of Candida albicans and Staphylococcus aureus respectively. Microwave oven used to disinfect specimens of heat-activated acrylic resin and soft linear. Oxalic, citric, tartaric acids, and alkaline peroxide were also used. Microorganisms that tested were Candida albicans and Staphylococcus aureus separately. Treatment with microwave or tartaric acid could achieve sterilization of both hot cured acrylic resins

... Show More
Preview PDF
Publication Date
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Color Stability of Different Aesthetic Archwires after Immersion into Different Types of Mouthwashes(An In Vitro Study)
...Show More Authors

Background: Because of the demands for aesthetic orthodontic appliances have increased, aesthetic archwires have been widely used to meet patient's aesthetic needs. The color stability of aesthetic archwires is clinically important, any staining or discoloration will affect patient’s acceptance and satisfaction. This study was designed to evaluate the color stability of different types of aesthetic archwires after immersion into different types of mouth washes. Materials and methods: Four brands of nickel titanium coated aesthetic arch wires: Epoxy coated (Orthotechnology and G&H) and Teflon coated (Dany and Hubit) were evaluated after 1 week, 3 weeks and 6 weeks of immersion into two types of mouthwashes (Listerine with alcohol and

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The Fraud under the fair value Exploratory Study
...Show More Authors

The research aim is to identify the concept of fair value and its measurement approaches, shed light on the concept of fraud and its forms, motives, as well as how to identify fraud under the fair value method.

I have been using the program package SSPS statistical in the calculation of the research variables, and the research sample was a group of university professors and auditors working in the federal board of Supreme Audit. 

 The researcher has reached some conclusions, the most important; the lack of conclusive evidence about management's intent in adopting the use of fair value raises several doubts about the credibility of the statements prepared in under the fa

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Apr 07 2025
Journal Name
Structures Congress 2025
Encased Pultruded I-GFRP Beam under Impact Loading
...Show More Authors

View Publication
Scopus Crossref
Publication Date
Mon Jun 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
High performance work systems and general industrial enterprise performance
...Show More Authors

High performance work systems and general industrial enterprise performance

View Publication Preview PDF
Crossref (1)
Crossref