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Directive and Steerable Radiation Pattern using SASPA Array

This work examines the ability of a special type of smart antenna array known as Switched Active Switched Parasitic Antenna (SASPA) to produce a directive and electronically steerable radiation pattern. The SASPA array consists of antenna elements that are switchable between active and parasitic states by using P-Intrinsic-N (PIN) diodes. The active element is the element that is supplied by the radio frequency while short-circuiting the terminals of an element in the array results in a parasitic element. Due to the strong mutual coupling between the elements, a directional radiation pattern with high gain and a small beamwidth can be produced with only one active element operating at a time. By changing the parasitic state to the active state sequentially for all elements, the directed radiation pattern can be easily rotated. The antenna array structure used in this work is the uniform circular array (UCA) to achieve symmetrical radiation patterns and full coverage of the entire azimuth plane. Also, a novel method for reducing the mutual coupling effect in SASPA arrays is proposed in this work. By using this method, some parameters of the generated SASPA’s radiation pattern can be controlled. The simulated results obtained from this work depict that an N-element SASPA-UCA produces N-symmetrical, switchable, and steerable radiation patterns with high gain, small beamwidth, and a high Front-to-Back (F/B) ratio. Also, the results show that further improvements in these parameters can be achieved by increasing the number of elements in the array. Additional simulations demonstrate that by including decaying function weight in each element's circuitry, the mutual coupling between the components of the SASPA-UCA array can be minimized. The aforementioned parameters can then be efficiently modified using this mutual coupling reduction.

 

 

 

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Publication Date
Sun Jul 30 2023
Journal Name
Iraqi Journal Of Science
Studying the Environmental Changes Using Remote Sensing and GIS

     The research aims to monitor environmental changes and study the state of desertification in the northeastern part of the Al-Najaf province, Iraq. The study area suffers from desertification and drought phenomena. Remote sensing systems "RS" and geographic information systems "GIS" are essential for monitoring environmental changes because they provide Earth observation satellites that contribute to detecting environmental changes. Two Sentinel 2 images were acquired on December 26, 2015, and November 29, 2021. The images were combined and used for indices calculations. Normalized vegetation difference index "NDVI,” Normalized difference index "NDWI," soil exposure index "BSI," and Normalized difference index "NDBI." The resul

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Publication Date
Fri Jun 30 2023
Journal Name
Iraqi Journal Of Science
Using Retrieved Sources for Semantic and Lexical Plagiarism Detection

     Plagiarism is described as using someone else's ideas or work without their permission. Using lexical and semantic text similarity notions, this paper presents a plagiarism detection system for examining suspicious texts against available sources on the Web. The user can upload suspicious files in pdf or docx formats. The system will search three popular search engines for the source text (Google, Bing, and Yahoo) and try to identify the top five results for each search engine on the first retrieved page. The corpus is made up of the downloaded files and scraped web page text of the search engines' results. The corpus text and suspicious documents will then be encoded as vectors. For lexical plagiarism detection, the system will

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Publication Date
Thu Feb 25 2016
Journal Name
Research Journal Of Applied Sciences, Engineering And Technology
Block Matching Algorithm Using Mean and Low Order Moments

In this study, a fast block matching search algorithm based on blocks' descriptors and multilevel blocks filtering is introduced. The used descriptors are the mean and a set of centralized low order moments. Hierarchal filtering and MAE similarity measure were adopted to nominate the best similar blocks lay within the pool of neighbor blocks. As next step to blocks nomination the similarity of the mean and moments is used to classify the nominated blocks and put them in one of three sub-pools, each one represents certain nomination priority level (i.e., most, less & least level). The main reason of the introducing nomination and classification steps is a significant reduction in the number of matching instances of the pixels belong to the c

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Publication Date
Thu Jan 01 2015
Journal Name
Applied And Computational Mathematics
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Publication Date
Tue Jan 31 2023
Journal Name
Iraqi Geological Journal
Discrimination Reef and Non-Reef Environments, Using REE Geochemistry

This research aims to distinguish the reef environment from the non-reef environment. The Oligocene-Miocene-succussion in western Iraq was selected as a case study, represented by the reefal limestone facies of the Anah Formation (Late Oligocene) deposited in reef-back reef environments, dolomitic limestone of the Euphrates Formation (Early Miocene) deposited in open sea environments, and gypsiferous marly limestone of the Fatha Formation (Middle Miocene) deposited in a lagoonal environment. The content of the rare earth elements (REEs) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Ho, Tm, Yb, Lu, and Y) in reef facies appear to be much lower than of those in the non-reef facies. The open sea facies have a low content of REEs due to bein

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Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Scheduling projects using dynamic programming style and smart algorithm

The aim of this research is to compare traditional and modern methods to obtain the optimal solution using dynamic programming and intelligent algorithms to solve the problems of project management.

It shows the possible ways in which these problems can be addressed, drawing on a schedule of interrelated and sequential activities And clarifies the relationships between the activities to determine the beginning and end of each activity and determine the duration and cost of the total project and estimate the times used by each activity and determine the objectives sought by the project through planning, implementation and monitoring to maintain the budget assessed 

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
Investigate and Prepare silver Nano Particles Using Jet Plasma

Nano- particles (Ag NPs) are synthesized by using plasma Jet  argon gas. The prepared Ag NPs are characterized by Atomic Absorption Spectroscopy (AAS) The measure was performed for different time exposuring 15,30,45 and 60 sec. The results shows the low concentration of nano-silver time expose (15 sec) and very) and high concentration at 60 sec. The UV-VIS spectrometer for nano-silver different time exsposuring to plasma, shows the Surface Plasmon Resonance (SPR) appeared around 419 nm, and the  energy gab is 4.1 eV for the 15 second exposure and 1.6eV for 60 second exposure.  The Scanning Probe Microscope (SPM) is used to identify the characterization of silver  nanoparticles, the average diameter of nano-silver  for 15 second exp

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Publication Date
Sun Aug 01 2021
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
Audio compression using transforms and high order entropy encoding

<span>Digital audio is required to transmit large sizes of audio information through the most common communication systems; in turn this leads to more challenges in both storage and archieving. In this paper, an efficient audio compressive scheme is proposed, it depends on combined transform coding scheme; it is consist of i) bi-orthogonal (tab 9/7) wavelet transform to decompose the audio signal into low &amp; multi high sub-bands, ii) then the produced sub-bands passed through DCT to de-correlate the signal, iii) the product of the combined transform stage is passed through progressive hierarchical quantization, then traditional run-length encoding (RLE), iv) and finally LZW coding to generate the output mate bitstream.

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Publication Date
Tue Jan 01 2019
Journal Name
Science International
Publication Date
Sat Sep 02 2017
Journal Name
Journal Of Engineering
Estimation Curve Numbers using GIS and Hec-GeoHMS Model

Recently, the development and application of the hydrological models based on Geographical Information System (GIS) has increased around the world. One of the most important applications of GIS is mapping the Curve Number (CN) of a catchment. In this research, three softwares, such as an ArcView GIS 9.3 with ArcInfo, Arc Hydro Tool and Geospatial Hydrologic Modeling Extension (Hec-GeoHMS) model for ArcView GIS 9.3, were used to calculate CN of (19210 ha) Salt Creek watershed (SC) which is located in Osage County, Oklahoma, USA. Multi layers were combined and examined using the Environmental Systems Research Institute (ESRI) ArcMap 2009. These layers are soil layer (Soil Survey Geographic SSURGO), 30 m x 30 m resolution of Digital Elevati

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