Preferred Language
Articles
/
jeasiq-2145
Comparison of Some Methods for Estimating Parameters of General Linear Model in Presence of Heteroscedastic Problem and High Leverage Points
...Show More Authors

Linear regression is one of the most important statistical tools through which it is possible to know the relationship between the response variable and one variable (or more) of the independent variable(s), which is often used in various fields of science. Heteroscedastic is one of the linear regression problems, the effect of which leads to inaccurate conclusions. The problem of heteroscedastic may be accompanied by the presence of extreme outliers in the independent variables (High leverage points) (HLPs), the presence of (HLPs) in the data set result unrealistic estimates and misleading inferences. In this paper, we review some of the robust weighted estimation methods that accommodate both Robust and classical methods in the detection of extreme outliers (High leverage points) (HLPs) and the determination of weights. The methods include both Diagnostic Robust Generalized Potential Based on Minimum Volume Ellipsoid (DRGP (MVE)), Diagnostic Robust Generalized Potential Based on Minimum Covariance Determinant (DRGP (MCD)), and Diagnostic Robust Generalized Potential Based on Index Set Equality (DRGP (ISE)). The comparison was made according to the standard error criterion of the estimated parameters  SE ( ) and SE ( ) of general linear regression model, for sample sizes (n=60, n=100, n=160), with different degree (severity) of heterogeneity, and contamination percentage (HLPs) are (τ =10%, τ=30%). it was found through comparison that weighted least squares estimation based on the weights of the DRGP (ISE) method are considered the best in estimating the parameters of the multiple linear regression model because they have the lowest standard error values of the estimators ( ) and ( )  as compared to other methods.

Paper type: A case study

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Jun 01 2021
Journal Name
Baghdad Science Journal
Numerical Solution for Linear Fredholm Integro-Differential Equation Using Touchard Polynomials
...Show More Authors

A new method based on the Touchard polynomials (TPs) was presented for the numerical solution of the linear Fredholm integro-differential equation (FIDE) of the first order and second kind with condition. The derivative and integration of the (TPs) were simply obtained. The convergence analysis of the presented method was given and the applicability was proved by some numerical examples. The results obtained in this method are compared with other known results.

 

View Publication Preview PDF
Scopus (9)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Thu Mar 20 2025
Journal Name
Tikrit Journal Of Engineering Sciences
Effect of Different Compressor Speeds on the Energy and Exergy of an Automobile Air-Conditioner Using R134a in the Absence and Presence of a Liquid-Suction Heat Exchanger
...Show More Authors

Refrigerant R134a has been widely utilized in automotive air conditioning systems (AACSs); R134a has a high global warming potential (GWP) of 1430 despite having zero ozone depletion potential (ODP). Coming refrigeration systems must include refrigerants with low GWP and zero ODP. The aim of this experimental study is to evaluate the thermal performance of an (AAC) with different values of compressor speeds, i.e., (1000, 1700, and 2400 rpm) and two thermal loads, i.e., (500 and 1000 Watt) with the absence and presence of liquid suction heat exchanger (LSHX) using R134a. The results showed that adding LSHX enhanced the COP cycle by 7.18%, 10.7%, and 3.09% for the first, second, and third speed, respectively, at 500 Watt, while the en

... Show More
View Publication
Scopus Crossref
Publication Date
Wed Apr 01 2009
Journal Name
6th.engineering Conference/college Of Eng. /university Of Baghdad
Comparison between analytical solution and experimental results for reinforced loose sand
...Show More Authors

Presents here in the results of comparison between the theoretical equation stated by Huang and Menq and laboratory model tests used to study the bearing capacity of square footing on geogrid-reinforced loose sand by performing model tests. The effects of several parameters were studied in order to study the general behavior of improving the soil by using the geogrid. These parameters include depth of first layer of reinforcement, vertical spacing of reinforcement layers, number of reinforcement layers and types of reinforcement layers The results show that the theoretical equation can be used to estimate the bearing capacity of loose sand.

Publication Date
Wed Aug 26 2020
Journal Name
International Journal Of Research In Social Sciences And Humanities
THE ROLE OF A PROTEAN CAREER IN HIGH PERFORMANCE
...Show More Authors

View Publication
Crossref
Publication Date
Thu Dec 08 2022
Journal Name
International Journal Of Interactive Mobile Technologies (ijim)
Implementation of RWP and Gauss Markov Mobility Model for Multi-UAV Networks in Search and Rescue Environment
...Show More Authors

Future generations of wireless networks are expected to heavily rely on unmanned aerial vehicles (UAVs). UAV networks have extraordinary features like high mobility, frequent topology change, tolerance to link failure, and extending the coverage area by adding external UAVs. UAV network provides several advantages for civilian, commercial, search and rescue applications. A realistic mobility model must be used to assess the dependability and effectiveness of UAV protocols and algorithms.  In this research paper, the performance of the Gauss Markov (GM) and Random Waypoint (RWP) mobility models in multi-UAV networks for a search and rescue scenario is analyzed and evaluated. Additionally, the two mobility models GM and RWP are descr

... Show More
View Publication
Crossref (21)
Crossref
Publication Date
Sun Oct 01 2023
Journal Name
Baghdad Science Journal
Synthesis and Characterization of Co-Polymer (Styrene / Allyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside) and Studying some of its thermal properties
...Show More Authors

In this research, a Co-polymer (Styrene / Allyl-2.3.4.6-tetra-O-acetyl-β-D-glucopyranoside) was synthesized from glucose in four steps using Addition Polymerization according to the radical mechanism using Benzoyl Peroxide (BP) as initiator. Initially, Allyl-2.3.4.6-tetra-O-acetyl-β-D-glucopyranoside monomer was prepared in three steps and the reaction was followed by (HPLC, FT-IR, TLC), in the fourth step the monomer was polymerized with Styrene and the structure was determined by FT-IR and NMR spectroscopy. The reaction conditions (temperature, reaction time, material ratios) were also studied to obtain the highest yield, the relative, specific and reduced viscosity of the prepared polymer was determined, from which the viscosity ave

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Organizational Ethnography and its Reflection in the Resonant LeadershipCase study at the University of Kufa
...Show More Authors

ABSTRACT

The purpose of this research is to investigate the relationship between organizational ethnography and resonant leadership in the University of Kufa, importance of research includes rare of studies that investigated the relationship between organizational ethnography and resonant leadership. Moreover, it comes as an attempt to reduce or bridge the knowledge gap between the variables of the research. As well as try to put the right foundations and appropriate for industry leaders of various Iraqi organizations aimed at profit or service. Based on the random sampling, 450 questionnaires were distributed to employees at the University of Kufa. Only 392 questionnaires were returned. Out of which 104 questionnaires we

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Thu Feb 04 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Economic losses caused by mole cricket Gryllotalpa gryllotalpa on some vegetable plants and agricultural crops: Economic losses caused by mole cricket Gryllotalpa gryllotalpa on some vegetable plants and agricultural crops
...Show More Authors

The study was conducted to estimate the economic losses caused by insect mole cricket Gryllotalpa gryllotalpa on some agricultural crops and Potato tubers in collage of Agriculture- Abu Ghraib season 2012-2013. Study showed Mole cricket caused percentage of infestation in spring potato tubers variety Luciana reached to 11.61% and the percentage of loss in weight of tubers reached 18.88%. The study showed that addition of animal manure (organic fertilizer) to the soil when planting potatoes in the autumn increased the incidence of infestation and the number of tunnels caused by mole cricket which led to from increased economic losses. When matured potato tubers were left for a longer period in the soil percentage of infestation by mole cr

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Using Tools Lean Accounting to Reduce the Costing: An Applied Research in General Company for Electric Industry
...Show More Authors

The developments accelerated in technology and rapid changes in the environment and increase numbers industrial countries and different desires and requirements of customers, lead to be produced in large quantities is not feasible due to changes listed above as well as the need to product variety and change in tastes and desires of consumers, all above led not to enable companies to discharge their products in the case of mass production and created the need to devise ways and new methods fit with the current situation, and accounting point no longer the traditional accounting systems able to meet the requirements needed by the companies to make decisions and know where waste and loss of resources resulting to invent new style away from

... Show More
View Publication Preview PDF
Publication Date
Sat Feb 22 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of time management on the performance of the functional business: Survey study at Al Salam General Company for Communications and Information Technology
...Show More Authors

The aim of the research is to know the level of time management application and its impact on the performance of the job, a survey search in the general company for communication and information technology and provide recommendations that help employees to optimize the use of time and improve performance, which is an important element in controlling the various functions of the company. In order to achieve the objectives of the research, the questionnaire was based on two main variables and distributed to a random sample of (44) employees in the company out of (308) employees, thus the proportion of the sample (14%). After collecting the samples from the sample, there are (6) incomplete forms that have been retri

... Show More
View Publication Preview PDF
Crossref