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
Tue Mar 28 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Comparative Analysis of the Fatty Acid Pattern of Silybum marianum with Nigella sativa by Gas Chromatography-Mass Spectrometry
...Show More Authors

Many studied were conducted to evaluate the antihepatotoxic and antioxidant activities of Silybum marianum and proved these actions. The Naturally grown seed in Iraqi-Kurdistan Region also were studied for its chemical contents and biological activities. Vegetable oils occur in various plant parts mainly concentrated in the seeds.

In this study comparison was made between the fatty acid patterns of two plant seeds, Silybum marianum and Nigella sativa. Seed sample of Silybum marianum and Nigella sativa were exposed for extraction and isolation of the fatty acid contents using two different solvents (petroleum ether and n-hexane) at 60-80oC using soxhlet apparatus and the oily extract

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 23 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Bayes Estimators of Reliability in the Exponential Distribution
...Show More Authors

Abstract

           We produced a study in Estimation for Reliability of the Exponential distribution based on the Bayesian approach. These estimates are derived using Bayesian approaches. In the Bayesian approach, the parameter of the Exponential distribution is assumed to be random variable .we derived bayes estimators of reliability under four types when the prior distribution for the scale parameter of the Exponential distribution is: Inverse Chi-squar

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Physics
A Study of the generation of laser soliton from spontaneous emission by ring cavity with carbon nanotube
...Show More Authors

We demonstrate a behavior of laser pulse grows through fiber laser inside and output cavity with a soliton fiber laser based on the multi-wall carbon nanotube saturable absorber (SA), we investigate the effects of a saturable absorber parameter on the mode-locking of a realistic Erbium fiber ring laser. Generalized nonlinear Schrodinger equation including the nonlinear effects as gain dispersion, second anomalous group velocity dispersion (GVD), self phase modulation (SPM), and two photon absorption used to describe pulse evolution. An analytical method has been used to understand and to quantify the role of the SA parameter on the propagation dynamics of pulse laser. We compute the chirp, power, width and phase of the soliton for range

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Estimation of the parameter of the Pareto distribution manual Using the general mediator estimator
...Show More Authors

Estimation of the tail index parameter of a one - parameter Pareto model has wide important by the researchers because it has awide application in the econometrics science and reliability theorem.

Here we introduce anew estimator of "generalized median" type and compare it with the methods of Moments and Maximum likelihood by using the criteria, mean square error.

 The estimator of generalized median type performing best over all.

View Publication Preview PDF
Crossref
Publication Date
Thu Dec 20 2007
Journal Name
Journal Of Planner And Development
The Weighted Index Number Method
...Show More Authors

The process of identifying the region is not an easy process when compared with other operations within the attribute or similarity. It is also not difficult if the process of identifying the region is based on the standard and standard indicators in its calculation. The latter requires the availability of numerical and relative data for the data of each case Any indicator or measure is included in the legal process

View Publication Preview PDF
Publication Date
Sun Aug 06 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparative for the EWMA charts by using non - homogeneous markov chain approach
...Show More Authors

In this study, we investigate the run length properties for the EWMA charts with time - varying control limits, and fast initial Response (FIR), for monitoring the mean of a normal process with a known standard deviation , by using non - homogeneous markov chain approach.

View Publication Preview PDF
Publication Date
Sat Jun 01 2024
Journal Name
University Of Thi-qar Journal Of Agricultural Research
A comparative histological, histometrical and hormonal study between the ovary and uterus of non-pregnant and pregnant local breed cat (Catus felius)
...Show More Authors

Samples of the ovary and uterus of local breed cats used to investigate the histological, histometrical and hormonal features. The paraffin embedding technique was used for processing of tissue that stained by hematoxyline and eosin stain, and massons trichrom stain. Ovary of at proestrus or oestrus phases composed of outer cortex that covered by cuboidal germinal epithelium and inner medulla. Tunica albuginea composed of a thin layer of characterized by fusiform stromal cells. The cortex content groups of Oogonial cells, numerous primordial follicles, little primary, secondary and tertiary follicles in addition for 1-2 follicular cysts and mature corpus letium. In pregnant cat the thickness of ovarian cortex was significantly incre

... Show More
View Publication
Crossref
Publication Date
Sat Dec 30 2023
Journal Name
Wasit Journal For Pure Sciences
A Review of Modern Methods of Synthesis 1, 3, 4-Oxadiazole as a Bioactive Compounds
...Show More Authors

ABSTRACT: Oxadiazole ring is a heterocyclic molecule with an oxygen and two nitrogen atoms spread throughout its five-membered structure. There are four different isomers that have been discovered, Because of their wide applications in a range of sectors, including medications . Some of these biological activity are; anticonvulsant capacity, anticancer as well, antibacterial, antiviral, antifungal,  antimalarial, antitubercular, anti-asthmatic, antidepressant, antidiabetic, antioxidant, antiparkinsonian, analgesic and  anti-inflammatory, are just some of the therapeutic uses that have drawn attention to drug candidates containing an oxadiazole moiety. This review, we will examine the various methods of oxadiazole synthesis. The mo

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Wed May 10 2017
Journal Name
Journal Of The College Of Languages (jcl)
Technical methods in foreign language teaching as a new method in foreign language learning
...Show More Authors

Unter dem Titel " Technische Methoden im Fremdsprachunterricht als eine neueste Methode im Fremdsprachlernen, die Spiele als Muster"

versteht man, dass die Forschung  sich mit einer neuen Methoden im Fremdsprachunterricht beschäftigt. Von den neuen Methoden im Unterricht sind die Spiele. So man sieht  in den letzten Jahren viele Artikel zum Thema Spiele im Fremdsprschunterricht. Davon gehen wir aus, dass die Spiele im Unterricht eine groβe Rolle spielt, denn diese Methode macht Lust, Spaβ im Lernenprozeβ. Die Spiele im Unterricht bezeichnen als ein Mittel, um Unterricht etwas Schönes , Nützliches und Lebendigs zu sein. Die Spiele sind vielfälltig und unterscheidet sich nach den Themen und Materialien. In dieser F

... Show More
View Publication Preview PDF
Publication Date
Wed Feb 01 2023
Journal Name
Baghdad Science Journal
Synthesis, Characterization, and Thermal Analysis of a New Acidicazo Ligand's Metal Complexes
...Show More Authors

The researchers wanted to make a new azo imidazole as a follow-up to their previous work. The ligand 4-[(2-Amino-4-phenylazo)-methyl]-cyclohexane carboxylic acid as a derivative of trans-4-(aminomethyl) cyclohexane carboxylic acid diazonium salt, and synthesis a series of its chelate complexes with metalions, characterized these compounds using a variety technique, including elemental analysis, FTIR, LC-Mass, 1H-NMRand UV-Vis spectral process as well TGA, conductivity and magnetic quantifications. Analytical data showed that the Co (II) complex out to 1:1 metal-ligand ratio with square planner and tetrahedral geometry, respectively while 1:2 metal-ligand ratio in the Cu(II), Cr(III), Mn(II), Zn(II), Ru(III)and Rh(III)complexes

... Show More
View Publication Preview PDF
Scopus (24)
Crossref (7)
Scopus Clarivate Crossref