Preferred Language
Articles
/
ijp-251
The effect of short range correlation on the inelastic C4 form factors of 18O nucleus
...Show More Authors

The effect of short range correlations on the inelastic longitudinal
Coulomb form factors for different states of J   4 , T  1with
excitation energies 3.553,7.114, 8.960 and 10.310 MeV in 18O is
analyzed. This effect (which depends on the correlation parameter )
is inserted into the ground state charge density distribution through
the Jastrow type correlation function. The single particle harmonic
oscillator wave function is used with an oscillator size parameter b.
The parameters  and b are considered as free parameters, adjusted
for each excited state separately so as to reproduce the experimental
root mean square charge radius of 18O. The model space of 18O does
not contribute to the transition charge density. As a result, the
inelastic Coulomb form factors of 18O comes absolutely from the
core polarization transition charge density. According to the
collective modes of nuclei, the core polarization transition charge
density is assumed to have the form of Tassie shape. It is found that
the introduction of the effect of short range correlations is necessary
for obtaining a remarkable modification in the calculated inelastic
longitudinal Coulomb form factors and considered as an essential for
explanation the data amazingly throughout the whole range of
considered momentum transfer.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 30 2021
Journal Name
Iraqi Journal Of Science
Gompertz Fréchet stress-strength Reliability Estimation
...Show More Authors

In this paper, the reliability of the stress-strength model is derived for probability P(Y<X) of a component having its strength X exposed to one independent stress Y, when X and Y are following Gompertz Fréchet distribution with unknown shape parameters and known parameters . Different methods were used to estimate reliability R and Gompertz Fréchet distribution parameters, which are maximum likelihood, least square, weighted least square, regression, and ranked set sampling. Also, a comparison of these estimators was made by a simulation study based on mean square error (MSE) criteria. The comparison confirms that the performance of the maximum likelihood estimator is better than that of the other estimators.

View Publication Preview PDF
Scopus (4)
Scopus Crossref
Publication Date
Sun Jun 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Different Methods for Estimating Location Parameter & Scale Parameter for Extreme Value Distribution
...Show More Authors

      In this study, different methods were used for estimating location parameter  and scale parameter for extreme value distribution, such as maximum likelihood estimation (MLE) , method of moment  estimation (ME),and approximation  estimators based on percentiles which is called white method in estimation, as the extreme value distribution is one of exponential distributions. Least squares estimation (OLS) was used, weighted least squares estimation (WLS), ridge regression estimation (Rig), and adjusted ridge regression estimation (ARig) were used. Two parameters for expected value to the percentile  as estimation for distribution f

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Apr 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Different Estimation Methods for System Reliability Multi-Components model: Exponentiated Weibull Distribution
...Show More Authors

        In this paper, estimation of system reliability of the multi-components in stress-strength model R(s,k) is considered, when the stress and strength are independent random variables and follows the Exponentiated Weibull Distribution (EWD) with known first shape parameter θ and, the second shape parameter α is unknown using different estimation methods. Comparisons among the proposed estimators through  Monte Carlo simulation technique were made depend on mean squared error (MSE)  criteria

View Publication Preview PDF
Crossref (1)
Crossref