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Product Spacing of Stress–Strength under Progressive Hybrid Censored for Exponentiated-Gumbel Distribution

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Computers, materials & Continua 2021年第3期66卷 2973-2995页

作者： R.Alshenawy mohamed A.H.Sabry ehab m.almetwally Hisham m.Elomngy Department of mathematics and Statistics King Faisal UniversityAl-Ahsa31982Saudi Arabia Department of Applied Statistics and Insurance Mansoura UniversityMansoura35516Egypt Department of mathematical Statistics Cairo UniversityCairo12613Egypt Department of Statistics Delta University for Science and TechnologyMansoura11152Egypt

maximum product spacing for stress–strength model based on progressive Type-II hybrid censored samples with different cases has been *** paper deals with estimation of the stress strength reliability model R=P(Ymbel distribution random variables with different shape parameters but having the same scale *** stress–strength reliability model is estimated under progressive Type-II hybrid censoring *** progressive Type-II hybrid censoring schemes were used,Case I:A sample size of stress is the equal sample size of strength,and same time of hybrid censoring,the product of spacing function under progressive Type-II hybrid censoring *** II:The sample size of stress is a different sample size of strength,in which the life-testing experiment with a progressive censoring scheme is terminated at a random time T 2 e0;*** maximum likelihood estimation and maximum product spacing estimation methods under progressive Type-II hybrid censored samples for the stress strength model have been discussed.A comparison study with classical methods as the maximum likelihood estimation method is ***,to compare the performance of various cases,markov chain monte Carlo simulation is conducted by using iterative procedures as Newton Raphson or conjugate-gradient ***,two real datasets are analyzed for illustrative purposes,first data for the breaking strengths of jute fiber,and the second data for the waiting times before the service of the customers of two banks.

关键词： Exponentiated Gumbel distribution stress-strength model progressive Type-II hybrid censoring maximum product spacing maximum likelihood

Bayesian and Non-Bayesian Analysis for the Sine Generalized Linear Exponential model under Progressively Censored Data

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Computer modeling in Engineering & Sciences 2024年第9期140卷 2795-2823页

作者： Naif Alotaibi A.S.Al-moisheer Ibrahim Elbatal mohammed Elgarhy ehab m.almetwally Department of mathematics and Statistics Faculty of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11432Saudi Arabia Department of mathematics College of ScienceJouf UniversityP.O.Box 848Sakaka72351Saudi Arabia mathematics and Computer Science Department Faculty of ScienceBeni-Suef UniversityBeni-Suef62521Egypt Department of Basic Sciences Higher Institute of Administrative SciencesBelbeisEgypt Faculty of Business Administration Delta University for Science and TechnologyGamasa11152Egypt

This article introduces a novel variant of the generalized linear exponential(GLE)distribution,known as the sine generalized linear exponential(SGLE)*** SGLE distribution utilizes the sine transformation to enhance its *** updated distribution is very adaptable and may be efficiently used in the modeling of survival data and dependability *** suggested model incorporates a hazard rate function(HRF)that may display a rising,J-shaped,or bathtub form,depending on its unique *** model includes many well-known lifespan distributions as separate *** suggested model is accompanied with a range of statistical *** model parameters are examined using the techniques of maximum likelihood and Bayesian estimation using progressively censored *** order to evaluate the effectiveness of these techniques,we provide a set of simulated data for testing *** relevance of the newly presented model is shown via two real-world dataset applications,highlighting its superiority over other respected similar models.

关键词： Sine G family generalized linear failure rate progressively censored data moments maximum likelihood estimation Bayesian estimation simulation

Assessing the Performance of Some Ranked Set Sampling Designs Using Hybrid Approach

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Computers, materials & Continua 2021年第9期68卷 3737-3753页

作者： mohamed.A.H.Sabry ehab m.almetwally Hisham m.Almongy Gamal m.Ibrahim Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza12613Egypt Faculty of Business Administration Delta University of Science and TechnologyMansoura35511Egypt Department of Statistics Delta University for Science and TechnologyMansouraEgypt High Institute for management Sciences Belqas35511Egypt

In this paper,a joint analysis consisting of goodness-of-fit tests and markov chain monte Carlo simulations are used to assess the performance of some ranked set sampling *** markov chain monte Carlo simulations are conducted when Bayesian methods with Jeffery’s priors of the unknown parameters of Weibull distribution are used,while the goodness of fit analysis is conducted when the likelihood estimators are used and the corresponding empirical distributions are *** ranked set sampling designs considered in this research are the usual ranked set sampling,extreme ranked set sampling,median ranked set sampling,and neoteric ranked set sampling *** intensive monte Carlo simulation study is conducted using Lindley’s approximation algorithm to compute the different designs’-based *** study showed that the dependent design“neoteric ranked set sampling design”is superior to other ranked set designs and the total relative efficiency is higher than the other designs’total relative efficiency.

关键词： Goodness of fit ranked set sampling Weibull distribution Bayesian estimation Lindley’s approximation neoteric ranked set sampling design

Exponentiated Generalized Inverse Flexible Weibull Distribution:Bayesian and Non-Bayesian Estimation Under Complete and TypeⅡCensored Samples with Applications

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Communications in mathematics and Statistics 2022年第3期10卷 413-434页

作者： m.El-morshedy m.S.Eliwa A.El-Gohary ehab m.almetwally R.EL-Desokey Department of mathematics College of Science and Humanities in Al-KharjPrince Sattam Bin Abdulaziz UniversityAl-Kharj 11942Saudi Arabia Department of mathematics Faculty of ScienceMansoura UniversityMansoura 35516Egypt Faculty of Business Administration Delta University of Science and TechnologyMansouraEgypt Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza 12613Egypt

In this paper,a new 4-parameter exponentiated generalized inverse flexible Weibull distribution is *** of its statistical properties are *** aim of this paper is to estimate the model parameters via several approaches,namely,maximum likelihood,maximum product spacing and *** to Bayesian approach,several techniques are used to get the Bayesian estimators,namely,standard error function,Linex loss function and entropy loss *** estimation herein is based on complete and censored *** Chain monte Carlo simulation is used to discuss the behavior of the estimators for each ***,two real data sets are analyzed to obtain the flexibility of the proposed model.

关键词： Weibull distribution Hazard rate function maximum likelihood estimation maximum product spacing estimation Bayesian estimation Censored samples Simulation

Bayesian Analysis in Partially Accelerated Life Tests for Weighted Lomax Distribution

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Computers, materials & Continua 2021年第9期68卷 2859-2875页

作者： Rashad Bantan Amal S.Hassan ehab almetwally m.Elgarhy Farrukh Jamal Christophe Chesneau mahmoud Elsehetry Deanship of Scientific Research King Abdulaziz UniversityJeddah21589Kingdom of Saudi Arabia Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza12613Egypt Faculty of Business Administration Delta University of Science and TechnologyMansoura11152Egypt The Higher Institute of Commercial Sciences Al Mahalla Al Kubra31951AlgarbiaEgypt Department of Statistics The Islamia University of BahawalpurPunjab 63100Pakistan Department of mathematics LMNOUniversity of CaenCaen14032France Deanship of Information Technology King Abdulaziz UniversityJeddah21589Kingdom of Saudi Arabia

Accelerated life testing has been widely used in product life testing experiments because it can quickly provide information on the lifetime distributions by testing products or materials at higher than basic conditional levels of stress,such as pressure,temperature,vibration,voltage,or load to induce early *** this paper,a step stress partially accelerated life test(SSPALT)is regarded under the progressive type-II censored data with random *** removals from the test are considered to have the binomial *** life times of the testing items are assumed to follow lengthbiased weighted Lomax *** maximum likelihood method is used for estimating the model parameters of length-biased weighted *** asymptotic confidence interval estimates of the model parameters are evaluated using the Fisher information *** Bayesian estimators cannot be obtained in the explicit form,so the markov chain monte Carlo method is employed to address this problem,which ensures both obtaining the Bayesian estimates as well as constructing the credible interval of the involved *** precision of the Bayesian estimates and the maximum likelihood estimates are compared by *** addition,to compare the performance of the considered confidence intervals for different parameter values and sample *** Bootstrap confidence intervals give more accurate results than the approximate confidence intervals since the lengths of the former are less than the lengths of latter,for different sample sizes,observed failures,and censoring schemes,in most ***,the percentile Bootstrap confidence intervals give more accurate results than Bootstrap-t since the lengths of the former are less than the lengths of latter for different sample sizes,observed failures,and censoring schemes,in most *** performance comparison is conducted by the experiments with real data.

关键词： Partially accelerated life testing progressive type-II censoring length-biased weighted Lomax Bayesian and bootstrap confidence intervals

mathematical analyses of the GPS receiver interference tolerance and mean time to loss lock

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Defence Technology（防务技术） 2019年第3期15卷 440-449页

作者： ehab m.Shaheen Sherif A.Elgamel Electronic Warfare Department Military Technical College

In this paper, novel mathematical expressions are derived for the Global Positioning System (GPS) receiver interference tolerance in the presence of different types of interference signals such as: continuous wave interference, narrowband interference, partial band interference, broadband interference, match spectrum interference and pulse interference. Also, in this paper the mean time to loss lock is determined in order to analyse the mentioned interferences effect on the GPS receiver. These derived analytical expressions are validated with the aid of extensive simulation experiments.

关键词： mathematical analyses GPS receiver interference tolerance

Effects of Plasticizers,Antioxidants and Burning Rate modifiers on Aging Performance of the HTPB/HmDI Composite Solid Propellant

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含能材料 2019年第1期27卷 21-27,90页

作者： Ahmed m Enew ehab Abadir Sahar Elmarsafy Karim K Elsharkawy Chemical Department Faculty of EngineeringCairo University School of Chemistry and Environment Beijing University of Aeronautics and Astronautics

The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HmDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.

关键词： polybutadiene(HTPB)/hexamethylene diisocyanate(HmDI)composite solid propellant plasticizers antioxidants burning rate modifiers aging program

Simulation of Water-Soil-Structure Interactions Using Incompressible Smoothed Particle Hydrodynamics

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Computers, materials & Continua 2020年第10期65卷 205-224页

作者： Abdelraheem m.Aly mitsuteru Asai ehab mahmoud mohamed Department of mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Department of mathematics Faculty of ScienceSouth Valley UniversityQena83523Egypt Civil Engineering Department Kyushu UniversityFukuoka819-0395Japan Electrical Engineering Department College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addwasir11991Saudi Arabia Electrical Engineering Department Faculty of EngineeringAswan UniversityAswan81542Egypt

In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure *** the current calculation,the water is modelled as a Newtonian *** soil is modelled in two different *** the first case,the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on mohr-Coulomb yield-stress criterion,and the viscosity is derived from the cohesion and friction *** addition,the fictitious suspension layers between water and soil depending on the concentration of soil are *** the second case,Hooke’s law introduces elastic *** ISPH,the pressure is evaluated by solving the pressure Poisson equation using a semi-implicit algorithm based on the projection method and an eddy viscosity for water is modelled by a large eddy simulation with the Smagorinsky *** the proposed ISPH method,the pressure is stabilized to simulate the multiphase flow between soil and *** experiments for water-soil suspension flow of Louvain erosional dam break with flat soil foundation,is simulated and validated using 3D-ISPH *** between water-soil interactions with different solid structures are *** results revealed that,the suspension layers with the Bingham model of soil gives more accurate results in the experiment as compared to the case of the Bingham model without suspension *** addition,the elastic soil model by the Hooke’s law can simulate soil hump accurately as compared to the Bingham *** the simulations,avoiding erosion behind the structure for preventing the structure break during flood are investigated by using an extended structure or a wedge structure.

关键词： Bingham model ISPH method rigid body water-soil interactions

Nanofluid Flows Within Porous Enclosures Using Non-Linear Boussinesq Approximation

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Computers, materials & Continua 2021年第3期66卷 3195-3213页

作者： Sameh E.Ahmed Dalal Alrowaili ehab mahmoud mohamed Abdelraheem m.Aly Department of mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Department of mathematics South Valley UniversityQena83523Egypt mathematics Department College of ScienceJouf UniversitySakakaSaudi Arabia Electrical Engineering Department College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addwasir11991Saudi Arabia Electrical Engineering Department Aswan UniversityAswan81542Egypt

In this paper,the Galerkin finite element method(FEm)together with the characteristic-based split(CBS)scheme are applied to study the case of the non-linear Boussinesq approximation within sinusoidal heating inclined enclosures filled with a non-Darcy porous media and *** enclosure has an inclination angle and its side-walls have varying sinusoidal temperature *** working fluid is a nanofluid that is consisting of water as a based nanofluid and Al2O3 as *** porous medium is modeled using the Brinkman Forchheimer extended Darcy *** obtained results are analyzed over wide ranges of the non-linear Boussinesq parameter 0≤ζ≤1,the phase deviation 00≤Φ≤1800,the inclination angle 00≤γ≤900,the nanoparticles volume fraction 0%≤φ≤4%,the amplitude ratio 0≤a≤1 and the Rayleigh number 104≤Ra≤*** results revealed that the average Nusselt number is enhanced by 0.73%,26.46%and 35.42%at Ra=104,105 and 106,respectively,when the non-linearBoussinesq parameter is varied from 0 to *** addition,rate of heat transfer in the case of a non-uniformly heating is higher than that of a uniformly ***-linear Boussinesq parameter rises the flow speed and heat transfer in an *** deviation makes clear changes on the isotherms and heat transfer rate on the right wall of an *** inclination angle varies the flow speed and it has a slight effect on heat transfer in an enclosure.

关键词： CBS scheme non-linear Boussinesq approximation nonuniformly heating non-darcy flow nanofluid