Heba Fathy Nagy

Dr. Heba Fathy Nagy

Cairo University, Giza, Al Jīzah, Egypt
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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2020 in Computers, Materials & Continua
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Journal Article
Open access
Amer Al-OmariAmer Al-Omari
Amer Al-Omari
IAIbrahim M. Almanjahie
Ibrahim M. Almanjahie
AHAmal S. Hassan
Amal S. Hassan
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy
In reliability analysis, the stress-strength model is often used to describe the life of a component which has a random strength (X) and is subjected to a random stress (Y). In this paper, we considered the problem of estimating the reliability R=P [Y

5 January 2021 in Iranian Journal of Science and Technology, Transactions A: Science
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Journal Article
Closed access
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Amal Soliman HassanAmal Soliman Hassan
Amal Soliman Hassan
Amer Al-OmariAmer Al-Omari
Amer Al-Omari
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy

3 June 2021 in Pakistan Journal of Statistics and Operation Research
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Journal Article
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Amal Soliman HassanAmal Soliman Hassan
Amal Soliman Hassan
Ehab M. AlmetwallyEhab M. Almetwally
Ehab M. Almetwally
MKMundher Abdullah Khaleel
Mundher Abdullah Khaleel
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy
In this paper, a weighted version of the power Lomax distribution referred to the weighted power Lomax distribution, is introduced. The new distribution comprises the length biased and the area biased of the power Lomax distribution as new models as well as containing an existing model as the length biased Lomax distribution as special model. Essential distributional properties of the weighted power Lomax distribution are studied. Maximum likelihood and maximum product spacing methods are proposed for estimating the population parameters in cases of complete and Type-II censored samples. Asymptotic confidence intervals of the model parameters are obtained. A sample generation algorithm along with a Monte Carlo simulation study is provided to demonstrate the pattern of the estimates for different sample sizes. Finally, a real-life data set is analyzed as an illustration and its length biased distribution is compared with some other lifetime distributions.

7 January 2023 in Mathematics
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Journal Article
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Amal Soliman HassanAmal Soliman Hassan
Amal Soliman Hassan
IAIbrahim Almanjahie
Ibrahim Almanjahie
Amer Al-OmariAmer Al-Omari
Amer Al-Omari
LALoai Mahmoud Alzoubi
Loai Mahmoud Alzoubi
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy
In this study, we look at how to estimate stress–strength reliability models, R1 = P (Y < X) and R2 = P (Y < X), where the strength X and stress Y have the same distribution in the first model, R1, and strength X and stress Z have different distributions in the second model, R2. Based on the first model, the stress Y and strength X are assumed to have the Lomax distributions, whereas, in the second model, X and Z are assumed to have both the Lomax and inverse Lomax distributions, respectively. With the assumption that the variables in both models are independent, the median-ranked set sampling (MRSS) strategy is used to look at different possibilities. Using the maximum likelihood technique and an MRSS design, we derive the reliability estimators for both models when the strength and stress variables have a similar or dissimilar set size. The simulation study is used to verify the accuracy of various estimates. In most cases, the simulation results show that the reliability estimates for the second model are more efficient than those for the first model in the case of dissimilar set sizes. However, with identical set sizes, the reliability estimates for the first model are more efficient than the equivalent estimates for the second model. Medical data are used for further illustration, allowing the theoretical conclusions to be verified.

3 November 2022 in Mathematics
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Journal Article
Open access
PDF file
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy
Amer Al-OmariAmer Al-Omari
Amer Al-Omari
Amal Soliman HassanAmal Soliman Hassan
Amal Soliman Hassan
GAGhadah Alomani
Ghadah Alomani
The ranked set sampling (RSS) methodology is an effective technique of acquiring data when measuring the units in a population is costly, while ranking them is easy according to the variable of interest. In this article, we deal with an RSS-based estimation of the inverted Kumaraswamy distribution parameters, which is extensively applied in life testing and reliability studies. Some estimation techniques are regarded, including the maximum likelihood, the maximum product of spacing’s, ordinary least squares, weighted least squares, Cramer–von Mises, and Anderson–Darling. We demonstrate a simulation investigation to assess the performance of the suggested RSS-based estimators via accuracy measures relative to simple random sampling. On the basis of actual data regarding the waiting times between 65 consecutive eruptions of Kiama Blowhole, additional conclusions have been drawn. The outcomes of simulation and real data application demonstrated that RSS-based estimators outperformed their simple random sampling counterparts significantly based on the same number of measured units.

1 January 2020 in Journal of Taibah University for Science
Verified
Journal Article
Open access
Amal Soliman HassanAmal Soliman Hassan
Amal Soliman Hassan
Heba Fathy NagyHeba Fathy Nagy
Heba Fathy Nagy
HMHiba Z. Muhammed
Hiba Z. Muhammed
MSMohammed S. Saad
Mohammed S. Saad
Stress-strength models are of special importance in reliability literature and engineering applications. This paper deals with the estimation problem of a stress-strength model incorporating multi-component system. The system is regarded as alive only if at least S out of k (S<k) strength components exceed the stress. The reliability of such system is obtained when strength and stress variables have Weibull distributions. Maximum likelihood estimator of RS,k and asymptotic confidence intervals are obtained based on upper record values. Bayesian estimator under squared error and linear exponential loss functions using gamma prior distributions and the corresponding credible intervals are obtained. Due to the lack of explicit forms for the Bayes estimates, the Markov Chain Monte Carlo (MCMC) method is employed. A simulation study is implemented to assess the performance of estimates. A real-life example is presented to show how the proposed model may be utilized in breaking strength of jute fibre data.