Preferred Language
Articles
/
jeasiq-288
A Comparative Study of Some Methods of Estimating Robust Variance Covariance Matrix of the Parameters Estimated by (OLS) in Cross-Sectional Data
...Show More Authors

 

Abstract

The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative,  the first one is  (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable but this method requires knowledge and knowledge of the nature of the problem and the private model of the problem, whether the Heteroscedasticity otherwise, the method (GLS) become inappropriate. The second alternative is a matrix contrast common variation fortified it does not require prior knowledge of the nature of your problem model, it's also an easy way and by this method has met with popular and interest in more than two decades by researchers, that the estimated of Robust covariance matrix the estimated parameters method(OLS), shall be according to data that is handled type, and we have dealt with in this study, cross-sectional data where the problem of Heteroscedasticity in contrast may be contained therein(Heteroscedasticity- Consistent Covariance matrix Estimation) and symbolized by the (HCCME) and includes many ways, and we have dealt with in our study of these methods  

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Mar 19 2015
Journal Name
Al-academy
Ideology and Film : a study in the expressive requirement: عمار هادي العرادي
...Show More Authors

Film and literature exchanges it’s influences since the early beginning of the motion pictures appearance .it was a phenomenon in other genres such as theatre ,short stories and novels .the film used out of this interaction with literature the content , themes and subjects whish were more attached to the society. based on that , the film gains it’s successes and wide spread of influences on it’s audiences who became more familiar with the motion picture style.Astrok , the French film critic wrote about “Camera the pain “ and called it as the a way of writing in the future .he was talking about the future’s role of the film .It is the importance of the film in the creation and documenting the life and its various fields.Becaus

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon May 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Screening and optimization of a novel gallic acid and tannase production under semi quantitative and quantitative methods
...Show More Authors
Abstract<p>Tannin acyl hydrolase as the common name of tannase is an inducible extracellular enzyme that causes the hydrolysis of galloyl ester and depside bonds in tannins, yielding gallic acid and glucose. The main objective of this study is to find a novel gallic acid and tannase produced by <italic>Acinetobacter Baumannii</italic>. A number of optimization steps were followed in order to improve the highest production of gallic acid and tannase. In present study, <italic>A. baumannii</italic> were isolated from ICU burn. <italic>A. baumannii</italic> was examined by microscopic examination, morphological and biochemical assay including oxidase and catalase. The </p> ... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Effect of Condenser Tubes Distribution for Domestic Refrigerator
...Show More Authors

The performance of a condenser in a domestic refrigerator system without wires and a condenser with a novel design consisted of number of loops as elliptical shape is investigated experimentally in this work. The experiment was conducted with a refrigerator designed to work with HFC134a, under no load and with loads of (1.5,3 and 12 liters of water). In particular, the effects of shape change of the condenser were very important in heat transfer enhancement and reduce of the frictional loss as a result of reducing the pressure drop in the condenser. The results shown that compressor work decreases with elliptical condenser about (8.6% to 11.3%), and then the power consumption decreases also. The performance of household refrigerator with

... Show More
View Publication Preview PDF
Publication Date
Wed May 10 2023
Journal Name
Journal Of Planner And Development
Relationship of LST, NDVI, and NDBI using Landsat-8 data in Duhok city in 2019-2022
...Show More Authors

One of the most significant elements influencing weather, climate, and the environment is vegetation cover. Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) over the years 2019–2022 were estimated based on four Landsat 8 TIRS’s images covering Duhok City. Using the radiative transfer model, the city&#39;s land surface temperature (LST) during the next four years was calculated. The aim of this study is to compute the temperature at the land&#39;s surface (LST) from the years 2019-2022 and understand the link, between LST, NDVI, and NDBI and the capability for mapping by LANDSAT-8 TIRS&#39;s. The findings revealed that the NDBI and the NDVI had the strongest correlation with the

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 02 2017
Journal Name
Al-khwarizmi Engineering Journal
Mathematical Modeling for the Clarifier Units and Turbidity Parameters in AL-KARAMA Treatment Plant
...Show More Authors

The high cost of chemical analysis of water has necessitated various researches into finding alternative method of determining portable water quality. This paper is aimed at modelling the turbidity value as a water quality parameter. Mathematical models for turbidity removal were developed based on the relationships between water turbidity and other water criteria. Results showed that the turbidity of water is the cumulative effect of the individual parameters/factors affecting the system. A model equation for the evaluation and prediction of a clarifier’s performance was developed:

Model: T = T0(-1.36729 + 0.037101∙10λpH + 0.048928t + 0.00741387∙alk)

The developed model will aid the predictiv

... Show More
View Publication Preview PDF
Publication Date
Mon Oct 22 2018
Journal Name
Journal Of Economics And Administrative Sciences
Leadership crisis and environmental pressures A Survey of the views of a sample of administrative leaders at Mosul University and the North technical University
...Show More Authors

The administrative leadership relies on a variety of behavioral paths in the functional areas in which it operates, and thus indicates its ability and thus has the upper hand in the organizational events, and in such a way that it can draw lessons and evaluate the results so as to test the expectations within the framework of the changes.

Does the study sample leadership have the characteristics that enable it to contain both crises and environmental stresses?

The aim of the study was to determine the location of the administrative leaders in the system of the study sample from the issue of crises and environmental pressures. The study concluded with a number of conclusions, the m

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Sep 30 2021
Journal Name
International Journal Of Research In Social Sciences And Humanities
The Anonymous Identity of Forced Migrants: A Post-Colonial Study
...Show More Authors

Colonialism invades the Third World countries, physically and psychologically. This article exposes but sample of the physical and psychological consequences of colonialism. The Beekeeper of Aleppo (2019) by the British novelist, Christy Lefteri is a typical novel to diagnose the harsh circumstances of individuals within and after the disaster. Since it depicts characters from Asian countries, it would be a best representative for all Asian people who suffer colonialism. Migration toward anonymity is the mere option for the colonized people. Aftermath, they experience displacement, trauma, and the loss of identity.

View Publication
Crossref
Publication Date
Sat Feb 26 2022
Journal Name
Iraqi Journal Of Science
A Comprehensive Study and Analysis of the Chaotic Chua Circuit
...Show More Authors

      was studied by taking several different values for the constant α and fixing the other three variables β, c and d with the values 25.58, -0.7142857, and -1.142, respectively. The purpose of this paper is to know the values by which the system transforms from a steady state to a chaotic state under the initial conditions x, y, and z that equal -1.6, 0 and 1.6 respectively. It was found that when the value of α is equal to 0, the Chua system is in a steady state, and when the value of α is equal to 9.5 and the wave is sinusoidal, the system is in oscillation, and when α is equal 13.4 the system is in a Quasi-chaotic state, and finally the system turns to the chaotic state when the value of α equals 15.0

... Show More
View Publication Preview PDF
Scopus (11)
Crossref (3)
Scopus Crossref
Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Engineering
Exact Stiffness Matrix for Nonprismatic Beams with Parabolic Varying Depth
...Show More Authors

In this paper, an exact stiffness matrix and fixed-end load vector for nonprismatic beams having parabolic varying depth are derived. The principle of strain energy is used in the derivation of the stiffness matrix.
The effect of both shear deformation and the coupling between axial force and the bending moment are considered in the derivation of stiffness matrix. The fixed-end load vector for elements under uniformly distributed or concentrated loads is also derived. The correctness of the derived matrices is verified by numerical examples. It is found that the coupling effect between axial force and bending moment is significant for elements having axial end restraint. It was found that the decrease in bending moment was
in the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon May 31 2021
Journal Name
Iraqi Journal Of Science
Jordan Left Derivation and Centralizer on Skew Matrix Gamma Ring
...Show More Authors

We define skew matrix gamma ring and describe the constitution of Jordan left centralizers and derivations on skew matrix gamma ring on a  -ring. We also show the properties of these concepts.

View Publication Preview PDF
Scopus Crossref