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A Comparison of Different Estimation Methods to Handle Missing Data in Explanatory Variables
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Missing data is one of the problems that may occur in regression models. This problem is usually handled by deletion mechanism available in statistical software. This method reduces statistical inference values because deletion affects sample size. In this paper, Expectation Maximization algorithm (EM), Multicycle-Expectation-Conditional Maximization algorithm (MC-ECM), Expectation-Conditional Maximization Either (ECME), and Recurrent Neural Networks (RNN) are used to estimate multiple regression models when explanatory variables have some missing values. Experimental dataset were generated using Visual Basic programming language with missing values of explanatory variables according to a missing mechanism at random general pattern and some ratios of missing values (10%, 20%, and 30%) with error variance values of 0.5, 1. 5, and 2, which were included in sample sizes of 25, 50, 100, and 500 and evaluated using Mean Squared Error (MSE). Simulation results show that RNN outperforms the other methods, followed by EM at small sample sizes.

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Publication Date
Sat Jan 29 2022
Journal Name
Phytoparasitica
Effects of Volatile Organic Compounds (VOCs) emitted by citrus infested with Aonidiella aurantii on the predator Rhyzobius lophanthae attraction
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Publication Date
Thu Feb 23 2023
Journal Name
Chalcogenide Letters
Studying the effect of copper on the p-ZnTe/n-AgCuInSe2/p-Si for thin films solar cell applications
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A thin film of AgInSe2 and Ag1-xCuxInSe2 as well as n-Ag1-xCuxInSe2 /p-Si heterojunction with different Cu ratios (0, 0.1, 0.2) has been successfully fabricated by thermal evaporation method as absorbent layer with thickness about 700 nm and ZnTe as window layer with thickness about 100 nm. We made a multi-layer of p-ZnTe/n-AgCuInSe2/p-Si structures, In the present work, the conversion efficiency (η) increased when added the Cu and when used p-ZnTe as a window layer (WL) the bandgap energy of the direct transition decreases from 1.75 eV (Cu=0.0) to 1.48 eV (Cu=0.2 nm) and the bandgap energy for ZnTe=2.35 eV. The measurements of the electrical properties for prepared films showed that the D.C electrical conductivity (σd.c) increase

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Publication Date
Wed May 25 2022
Journal Name
Iraqi Journal Of Science
Determination of Electrons Temperature and Density For Ag, Zn, and Cu metals using Plasma jet System at atmospheric pressure
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      Under atmospheric pressure, an argon plasma stream was sustained and its plasma characteristics were examined. The emission spectra of plasma created in a plasma jet system using argon gas were observed for three metals (Ag, Zn, and Cu) for the anode and varied flow rates ranging from 1–4 L/min. at constant voltage, and normal atmospheric pressure. The spectral lines of excited Ar, Ag, Zn, and Cu species were identified at a wavelength of (650–900) nm .The Debye length, sphere, and temperature of an electron are all measured. Optical emission spectrometer (OES) equipment was used to capture the spectrum produced by the plasma at various argon gas flow rates.The temperature and density of the electron (Te) and (n

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Publication Date
Sun Nov 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Thermophysical properties of [EMIM][BF<sub>4</sub>] and [HMIM][PF<sub>6</sub>] imidazolium ionic liquids with MWCNTs
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Abstract<p>In this study, several ionanofluids (INFs) were prepared in order to study their efficiency as a cooling medium at 25 °C. The two-step technique is used to prepare ionanofluid (INF) by dispersing multi-walled carbon nanotubes (MWCNTs) in two concentrations 0.5 and 1 wt% in ionic liquid (IL). Two types of ionic liquids (ILs) were used: hydrophilic represented by 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF<sub>4</sub>] and hydrophobic represented by 1-hexyl-3-methylimidazolium hexafluorophosphate [HMIM][PF<sub>6</sub>]. The thermophysical properties of the prepared INFs including thermal conductivity (TC), density and viscosity were measured experimental</p> ... Show More
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Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Improving the efficiency and security of passport control processes at airports by using the R-CNN object detection model
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The use of real-time machine learning to optimize passport control procedures at airports can greatly improve both the efficiency and security of the processes. To automate and optimize these procedures, AI algorithms such as character recognition, facial recognition, predictive algorithms and automatic data processing can be implemented. The proposed method is to use the R-CNN object detection model to detect passport objects in real-time images collected by passport control cameras. This paper describes the step-by-step process of the proposed approach, which includes pre-processing, training and testing the R-CNN model, integrating it into the passport control system, and evaluating its accuracy and speed for efficient passenger flow

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Publication Date
Thu May 17 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Scan Rate and pH on Determination Amoxilline Using Screen Printed Carbon Electrode Modified With Functionalized Graphene Oxide
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  Graphene oxide GO was functionalized with 4-amino, 3-substituted 1H, 1, 2, 4 Triazole 5(4H) thion (ASTT) to obtain GOT. GOT characterized by FT-IR, XRD.via modification of the working electrode of the SPCE with the prepared nanomaterial ( GOT) the effect of scan rate and pH on the determination of Amoxilline (AMOX) was studied using cyclic voltammetry. AMOX show various responses at pH ranging from 2 to 7 and also was observed sharp increase in the oxidation peaks in the pH 3. The formal potential (midpoint) for AMOX was highly pH-dependent. From the effect of scan rate, surface coverage concentration  of electroactive species the values of the electron transfer coefficient and the electron transfer constant rate ket

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Publication Date
Sat Mar 31 2018
Journal Name
Journal Of Engineering
Estimating Angle of Arrival (AOA) for Wideband Signal by Sensor Delay Line (SDL) and Tapped Delay Line (TDL) Processors
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Angle of arrival (AOA) estimation for wideband signal becomes more necessary for modern communication systems like Global System for Mobile (GSM), satellite, military applications and spread spectrum (frequency hopping and direct sequence). Most of the researchers are focusing on how to cancel the effects of signal bandwidth on AOA estimation performance by using a transversal filter (tap delay line) (TDL). Most of the researchers were using two elements array antenna to study these effects. In this research, a general case of proposed (M) array elements is used. A transversal filter (TDL) in phase adaptive array antenna system is used to calculate the optimum number of taps required to compensate these effect. The propo

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Publication Date
Sat Sep 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Dimensions of Virtuous Leadership and its Effect on organizational conflict: Applied Research on State Property Departmentin Al-Najaf Governorate
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This research aims to know the impact of leadership integrity as explanatory variable including its dimensions (courage, asceticism, justice, rationality, and humanity) on organizational conflict as responding variable. This research depended on the descriptive-constructive approach through the responses of a sample of (79) employees from (Real Estate Office of The State) in Al-Najaf province. The analyzing of the study done by using (Smart PLS) program to calculate (R2, t, p). Many results have been concluded and one of them, there is significant impact correlation of the leadership integrity on organizational conflict. There are many suggestions have been reached depending on the results reached and one of them is the necess

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Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
Preparation and characterization of mawsonite Cu6Fe2SnS8 [CFTS] thin films via the semi-computerized spray pyrolysis technique for photovoltaic applications
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Publication Date
Tue Nov 01 2022
Journal Name
Journal Of Engineering
Finite Element Modeling of One-Way Recycled Aggregate Concrete Slabs Strengthened using Near-Surface Mounted CFRPs under Repeated Loading
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This study offers numerical simulation results using the ABAQUS/CAE version 2019 finite element computer application to examine the performance, and residual strength of eight recycle aggregate RC one-way slabs. Six strengthened by NSM CFRP plates were presented to study the impact of several parameters on their structural behavior. The experimental results of four selected slabs under monotonic load, plus one slab under repeated load, were validated numerically. Then the numerical analysis was extended to different parameters investigation, such as the impact of added CFRP length on ultimate load capacity and load-deflection response and the impact of concrete compressive strength value on the structural performance of

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