Preferred Language
Articles
/
ijs-1982
A Comparison of Different Estimation Methods to Handle Missing Data in Explanatory Variables
...Show More Authors

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.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Oct 06 1996
Journal Name
Iraqi Journal Of Chemistry
Synthesis of new Schiff bases derived from [3-amino-3-C-cyano-3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-allofuranose
...Show More Authors

Aromatic Schiff-bases are known to have antibacterial activity, but most of these compounds are sparingly soluble in water. The present work describes the synthesis of new Schiff-bases derived from branched aminosugars. Treatment of 3-Amino-3-Cyano-3-Deoxy-1,2:5,6-Di-O-Isopropylene-α-D-Allofuranose (1) with the aldehydes (2) under reflux in methanol afforded the Schiff-bases (3) in good yields. The new Schiff-bases were in accord with their NMR, IR spectral data and elemental analysis.

Preview PDF
Publication Date
Wed Nov 01 2017
Journal Name
Research Journal Of Pharmaceutical, Biological And Chemical Sciences
Preparation, Spectral studies and Biological Efficiency of Metal (II) Mixed Ligand Complexes Schiff Base derived from (Benzaldehyde and OAminoaniline) with 8-Hydroxyquinoline
...Show More Authors

fication of benzaldehyde (C6H5CHO) and O- amino aniline O-C6H4(NH2)2 in ethanol with 8- Hydroxyquinoline (8HQ) . Formed compounds were acquired of 1:1:2 molar proportion reactions for metal ions and ligands (L) and 2(8HQ) during reaction for MCl2 .nH2O salt products complexes conformable into the forms [M(L)(8HQ)2] ,where M = Mn(II),Co(II) and Ni(II). Whole the compounds were identified during the basis of their; FT-IR and U.V spectrum, melting point, molar conduct, identify of the percentage from the metal at the complexes via flame (AAS), C, H and N content of the Schiff base (L) and metal complexes were analysis and magnetic susceptibility menstruations. A hexagonal coordinated metal complexes were proposed to the separated complexes of

... Show More
Publication Date
Mon Aug 07 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Preparation and Structural Studies of new Metal Complexes with 2-N(4- N,N- dimethyl benzyliden ) 5 - (p- methoxy phenyl)- 1,3,4- thiodiazole
...Show More Authors

A new Schiff base, 2-N( 4- N,N – dimethyl benzyliden )5 – (p- methoxy phenyl) – 1,3,4- thiodiazol ,and their metal complexes Cu (Π) ,Ni (Π),         Fe (III) , Pd (Π) , Pt (IV) , Zn(Π) ,V(IV) and Co (Π) , were synthesized. The prepared complexes were identified and their structural geometries were suggested by using flam atomic absorption technique , FT-IR and Uv-Vis spectroscopy, in addition to magnetic susceptibility and conductivity measurements. The study of the nature of the complexes formed in ethanol solution , following the mole ratio method , gave results which were compared successfully with those obtained from the isolated solid state studied. Structur

... Show More
View Publication Preview PDF
Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
Theoretical Calculation of the Electron Transport Parameters and Energy Distribution Function for CF3I with noble gases mixtures using Monte Carlo simulation program
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Mar 04 2020
Journal Name
Frontiers In Plant Science
Suppression of Arabidopsis Mediator Subunit-Encoding MED18 Confers Broad Resistance Against DNA and RNA Viruses While MED25 Is Required for Virus Defense
...Show More Authors

View Publication
Scopus (5)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Thu Jan 01 2015
Journal Name
Journal Of Nanomaterials
Comparative Studies on Thermal Performance of Conic Cut Twist Tape Inserts with SiO<sub>2</sub>and TiO<sub>2</sub>Nanofluids
...Show More Authors

This paper presents a comparison study on thermal performance conic cut twist tape inserts in laminar flow of nanofluids through a constant heat fluxed tube. Three tape configurations, namely, quadrant cut twisted tape (QCT), parabolic half cut twisted tape (PCT), and triangular cut twisted (VCT) of twist ratioy= 2.93 and cut depthde= 0.5 cm were used with 1% and 2% volume concentration of SiO2/water and TiO

... Show More
View Publication
Scopus (7)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sun May 10 2020
Journal Name
Baghdad Science Journal
Prevalence of Quinolones Resistance Proteins Encoding Genes (qnr genes) and Co-Resistance with β-lactams among Klebsiella pneumoniae Isolates from Iraqi Patients
...Show More Authors

This study investigated the prevalence of quinolones resistance proteins encoding genes (qnr genes) and co-resistance for fluoroquinolones and β-lactams among clinical isolates of Klebsiella pneumoniae.  Out of 150 clinical samples, 50 isolates of K. pneumoniae were identified according to morphological and biochemical properties. These isolates were collected from different clinical samples, including 15 (30%) urine, 12 (24%) blood, 9 (18%) sputum, 9 (18%) wound, and 5 (10%) burn. The minimum inhibitory concentrations (MICs) assay revealed that 15 (30%) of isolates were resistant to ciprofloxacin (≥4µg/ml), 11 (22%) of isolates were resistant to levofloxacin (≥8 µg/ml), 21 (42%) of isolates were re

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
The Conflict of Active Regional and International Powers over Nagorny Karabakh Region: وداد حسين خضير علي , و مهيمن عبد الحليم طه الوادي
...Show More Authors

      The current study is descriptive; it focuses on studying the contemporary geopolitical problem, and sectarian differences in Caucasus. Nagorno-Karabakh is considered an important disputed region nowadays. Many parties and states participated in this dispute, especially after the conflict had developed into an open war between Armenia and Azerbaijan. Thus, the study aims to examine the causes of the conflict in this region, analyze the international positions on this conflict, and find if Armenia was able to occupy this region. The methodology adopted by the researchers is the functional approach, and the theory of power analysis that Cohen created for analyzing all strengths that drove each of the parties t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 28 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of FeІІ , CoІІ , NiІІ , CuІІ and ZnІІ Complexes With Dithiocarbamate and N-Donor Ligands
...Show More Authors

New complexes of first series of transition metals with P-amino benzene dithiocarbamate of the general formula [M(PABdtc)2] and [ M(PABdtc)2(L)n] M=Fe( ІІ ),Co( ІІ ),Ni( ІІ ) ,Cu(ІІ) and Zn (ІІ). PABdtc = Paraamino benzene dithiocarbamate ,n=2 when  L= Py,É£-Pic,iso qunoline ,3,5lutidine  n=1when L=1,10-phenanthroline, en, 2,-2bipy.and the type(R)4N[Ni(PABdtc)3] R= methyl, ethyl are prepared. Physico chemical characterization of these complexes was applied  using magnetic susceptibility measurements, molar conductance , Infrared and electronic spectra, Metal content measurements, molar conductance indicate complexes of the type [M(PABdtc)2] and [M(PABdtc)2(L)n] are non-electrolyte

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 01 2017
Journal Name
International Journal Of Science And Research (ijsr)
The Effect of the Five Fingers Strategy and Traffic Signals Strategy on Physics First Grade Intermediate School Students' Achievement and Personal Intelligence
...Show More Authors

The aim of this research is to know the effect of two strategies of active learning, the five fingers and traffic signals, on the first grade intermediate level student's achievement and personal intelligence. The research sample was chosen from the Al- Mansour intermediate school for boys, including (101) students divided into three groups chosen randomly which represented the first experimental group (32) students, the second experimental group (34) students, and the control group (33) students. To achieve the research aims, the research prepared a physics achievement test containing (26) items, and a personal intelligence test containing (20) items. The psychometric characteristics, of the tests were checked up the following results were

... Show More