Preferred Language
Articles
/
QBamBYcBVTCNdQwC6S_k
A Partial CSI Estimation Approach for Downlink FDD massive-MIMO System with Different Base Transceiver Station Topologies
...Show More Authors

Massive multiple-input multiple-output (massive-MIMO) is a promising technology for next generation wireless communications systems due to its capability to increase the data rate and meet the enormous ongoing data traffic explosion. However, in non-reciprocal channels, such as those encountered in frequency division duplex (FDD) systems, channel state information (CSI) estimation using downlink (DL) training sequence is to date very challenging issue, especially when the channel exhibits a shorter coherence time. In particular, the availability of sufficiently accurate CSI at the base transceiver station (BTS) allows an efficient precoding design in the DL transmission to be achieved, and thus, reliable communication systems can be obtained. In order to achieve the aforementioned objectives, this paper presents a feasible DL training sequence design based on a partial CSI estimation approach for an FDD massive-MIMO system with a shorter coherence time. To this end, a threshold-based approach is proposed for a suitable DL pilot selection by exploring the statistical information of the channel covariance matrix. The mean square error of the proposed design is derived, and the achievable sum rate and bit-error-rate for maximum ratio transmitter and regularized zero forcing precoding is investigated over different BTS topologies with uniform linear array and uniform rectangular array. The results show that a feasible performance in the DL FDD massive-MIMO systems can be achieved even when a large number of antenna elements are deployed by the BTS and a shorter coherence time is considered.

Scopus Clarivate Crossref
View Publication
Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Southwest Jiaotong University
A Recognition System for Subjects' Signature Using the Spatial Distribution of Signature Body
...Show More Authors

This investigation proposed an identification system of offline signature by utilizing rotation compensation depending on the features that were saved in the database. The proposed system contains five principle stages, they are: (1) data acquisition, (2) signature data file loading, (3) signature preprocessing, (4) feature extraction, and (5) feature matching. The feature extraction includes determination of the center point coordinates, and the angle for rotation compensation (θ), implementation of rotation compensation, determination of discriminating features and statistical condition. During this work seven essential collections of features are utilized to acquire the characteristics: (i) density (D), (ii) average (A), (iii) s

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon Feb 25 2019
Journal Name
Iraqi Journal Of Physics
Simulation of indoor solar illumination system for a library hall in Baghdad city
...Show More Authors

A concept of indoor solar illumination is described and simulated. The solar illumination system is composed of a tracking primary reflector, a selective secondary reflector, a visible light guide and a scattering solid glass tube fixture. Each part of the solar illumination system is optically suited and compatible with other parts to realize high efficiency. The simulation is conducted for Baghdad city for a library hall. Two major days over a year are chosen to investigate the illumination system for acceptable visible light level for reading hall. The two days are: summer solstice day and winter solstice day at 8:00 AM and 12:00 PM for each. Research results showed that the design of the solar system is achieved on the base of minimu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2020
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
A Haptic feedback system based on leap motion controller for prosthetic hand application
...Show More Authors

Leap Motion Controller (LMC) is a gesture sensor consists of three infrared light emitters and two infrared stereo cameras as tracking sensors. LMC translates hand movements into graphical data that are used in a variety of applications such as virtual/augmented reality and object movements control. In this work, we intend to control the movements of a prosthetic hand via (LMC) in which fingers are flexed or extended in response to hand movements. This will be carried out by passing in the data from the Leap Motion to a processing unit that processes the raw data by an open-source package (Processing i3) in order to control five servo motors using a micro-controller board. In addition, haptic setup is proposed using force sensors (F

... Show More
View Publication
Scopus (3)
Crossref (2)
Scopus Crossref
Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Low-carbon Technologies
Performance evaluation of the photovoltaic thermal system with a fin array and surface zigzag layout
...Show More Authors
Abstract<p>Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep</p> ... Show More
View Publication
Scopus (10)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Tue Nov 13 2012
Journal Name
Wireless Personal Communications
Design and Implementation of a Scalable RFID-Based Attendance System with an Intelligent Scheduling Technique
...Show More Authors

View Publication
Scopus (17)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Thu Jan 12 2023
Journal Name
Mathematics
Dynamical Behavior of a Cancer Growth Model with Chemotherapy and Boosting of the Immune System
...Show More Authors

In this study, we set up and analyze a cancer growth model that integrates a chemotherapy drug with the impact of vitamins in boosting and strengthening the immune system. The aim of this study is to determine the minimal amount of treatment required to eliminate cancer, which will help to reduce harm to patients. It is assumed that vitamins come from organic foods and beverages. The chemotherapy drug is added to delay and eliminate tumor cell growth and division. To that end, we suggest the tumor-immune model, composed of the interaction of tumor and immune cells, which is composed of two ordinary differential equations. The model’s fundamental mathematical properties, such as positivity, boundedness, and equilibrium existence, are exami

... Show More
View Publication Preview PDF
Scopus (18)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Sat Oct 16 2021
Journal Name
Energies
Performance Analysis of a Solar Cooling System with Equal and Unequal Adsorption/Desorption Operating Time
...Show More Authors

In solar-thermal adsorption/desorption processes, it is not always possible to preserve equal operating times for the adsorption/desorption modes due to the fluctuating supply nature of the source which largely affects the system’s operating conditions. This paper seeks to examine the impact of adopting unequal adsorption/desorption times on the entire cooling performance of solar adsorption systems. A cooling system with silica gel–water as adsorbent-adsorbate pair has been built and tested under the climatic condition of Iraq. A mathematical model has been established to predict the system performance, and the results are successfully validated via the experimental findings. The results show that, the system can be operational

... Show More
View Publication
Scopus (11)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Wed Sep 01 2021
Journal Name
Journal Of Applied Mathematics
The Dynamics of a Tritrophic Leslie-Gower Food-Web System with the Effect of Fear
...Show More Authors

The avoidance strategy of prey to predation and the predation strategy for predators are important topics in evolutionary biology. Both prey and predators adjust their behaviors in order to obtain the maximal benefits and to raise their biomass for each. Therefore, this paper is aimed at studying the impact of prey’s fear and group defense against predation on the dynamics of the food-web model. Consequently, in this paper, a mathematical model that describes a tritrophic Leslie-Gower food-web system is formulated. Sokol-Howell type of function response is adapted to describe the predation process due to the prey’s group defensive capability. The effects of fear due to the predation process are considered in the first two levels

... Show More
View Publication
Scopus (29)
Crossref (13)
Scopus Clarivate Crossref
Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Extraction and estimation of curcumin compounds from turmeric (Curcuma longa) rhizomes by using different variables (solvent, time and temperature).
...Show More Authors

The study aimed to investigate the effect of different times as follows 0.5, 1.00, 2.00 and 3.00 hrs, type of solvent (acetone, methanol and ethanol) and temperature (~ 25 and 50)ºc on curcumin percentage yield from turmeric rhizomes. The results showed significant differences (p? 0.05) in all variables. The curcumin content which were determined spectrophotometrically ranged between (0.55-2.90) %. The maximum yield was obtained when temperature, time and solvent were 50ºC, 3 hrs and acetone, respectively.

View Publication Preview PDF
Crossref
Publication Date
Fri Dec 01 2023
Journal Name
Russian Journal Of Bioorganic Chemistry
A Brief Review on Schiff Base, Synthesis, and Their Antimicrobial Activities
...Show More Authors

View Publication
Scopus (10)
Crossref (6)
Scopus Clarivate Crossref