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Gravitational collapse with standard and dark energy in the teleparallel equivalent of general relativity

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Chinese Physics B 2012年第6期21卷 57-62页

作者： gamal G.L.Nashed mathematics Department Faculty of ScienceKing Faisal UniversityP.O.Box 380 Al-Ahsaa 31982the Kingdom of Saudi Arabia mathematics Department Faculty of ScienceAin Shams UniversityCairo11566Egypt Center for Theoretical Physics British University of EgyptSherouk City 11837P.O.Box 43Egypt

A perfect fluid with self-similarity of the second kind is studied within the framework of the teleparallel equivalent of general relativity （TEGR）. A spacetime which is not asymptotically fiat is derived. The energy conditions of this spacetime are studied. It is shown that after some time the strong energy condition is not enough to satisfy showing a transition from standard matter to dark energy. The singularities of this solution are discussed.

关键词： perfect fluid with self-similarity of second kind teleparallel equivalent of general relativ-ity asymptotically nonflat spacetime energy conditions

EFFECT OF RANDOm NOISE ON STOCHASTIC COmPLEX DAmPED NONLINEAR SYSTEmS

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EFFECT OF RANDOM NOISE ON STOCHASTIC COMPLEX DAMPED NONLINEA...

Cosmological application on five-dimensional teleparallel theory equivalent to general relativity

庆祝中国力学学会成立50周年暨中国力学学会学术大会’2007

作者： mahmoud gamal m. Department of mathematics Faculty of ScienceUniversity of Assiut

Complex damped nonlinear systems have been introduced and studied in our previous investigateons. These systems appear in many important applications in engineering,physics and mechanics,for example,in rotor dynamics,robots,shells and in high energy *** the aim of this paper is to continue our investigations by studying these systems with random noise.

关键词： complex damped dynamical system top Lyapunov exponent Poincar(?) map analysis random phase stabilization time evolution

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Chinese Physics B 2012年第10期21卷 122-129页

作者： gamal G.L.Nashed mathematics Department Faculty of ScienceKing Faisal UniversityP.O.Box 380 Al-Ahsaa 31982the Kingdom of Saudi Arabia mathematics Department Faculty of ScienceAin Shams UniversityCairo 11566Egypt Center for Theoretical Physics British University of EgyptSherouk City 11837P.O.Box 43Egypt

A theory of（4＋1）-dimensional gravity has been developed on the basis of which equivalent to the theory of general relativity by *** fundamental gravitational field variables are the 5-dimensional（5D） vector fields（pentad）,defined globally on a manifold m,and gravity is attributed to the *** Lagrangian density is quadratic in the torsion *** then apply the field equations to two different homogenous and isotropic geometric structures which give the same line element,i.e.,FRW in five *** cosmological parameters are calculated and some cosmological problems are discussed.

关键词： 5D teleparallel equivalent of general relativity 5D solutions cosmological parameters cosmological problems

Ensemble machine Learning to Enhance Q8 Protein Secondary Structure Prediction

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Computers, materials & Continua 2022年第11期73卷 3951-3967页

作者： moheb R.Girgis Rofida m.gamal Enas Elgeldawi Computer Science Department Faculty of ScienceMinia University61519MiniaEgypt

Protein structure prediction is one of the most essential objectives practiced by theoretical chemistry and bioinformatics as it is of a vital importance in medicine,biotechnology and *** secondary structure prediction(PSSP)has a significant role in the prediction of protein tertiary structure,as it bridges the gap between the protein primary sequences and tertiary structure *** secondary structures are classified into two categories:3-state category and 8-state *** the 3 states and the 8 states of secondary structures from protein sequences are called the Q3 prediction and the Q8 prediction problems,*** 8 classes of secondary structures reveal more precise structural information for a variety of applications than the 3 classes of secondary structures,however,Q8 prediction has been found to be very challenging,that is why all previous work done in PSSP have focused on Q3 *** this paper,we develop an ensemble machine Learning(mL)approach for Q8 PSSP to explore the performance of ensemble learning algorithms compared to that of individual mL algorithms in Q8 *** ensemble members considered for constructing the ensemble models are well known classifiers,namely SVm(Support Vector machines),KNN(K-Nearest Neighbor),DT(Decision Tree),RF(Random Forest),and NB(Naïve Bayes),with two feature extraction techniques,namely LDA(Linear Discriminate Analysis)and PCA(Principal Component Analysis).Experiments have been conducted for evaluating the performance of single models and ensemble models,with PCA and LDA,in Q8 *** novelty of this paper lies in the introduction of ensemble learning in Q8 PSSP *** experimental results confirmed that ensemble mL models are more accurate than individual mL *** also indicated that features extracted by LDA are more effective than those extracted by PCA.

关键词： Protein secondary structure prediction(PSSP) Q3 prediction Q8 prediction ensemble machine leaning boosting bagging

Effect of melatonin and/or cysteamine on development and vitrification of buffalo embryos

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Asian pacific Journal of Reproduction 2017年第4期6卷 176-180页

作者： mohamed mm El-Sokary mohamed El-Raey Karima Ghm.mahmoud mahmoud EA Abou El-Roos gamal mS Sosa Department of Theriogenology Faculty of Veterinary MedicineBenha UniversityP.O:13736TokhKaliobiaEgypt Department of Anim.Reprod.&A.I. National Research CenterDokkiGizaEgypt

Objective:To assess the effects of melatonin and/or cysteamineonin vitro maturation, culturing and post-warming of buffalo ***: Buffalo oocytes were classified into control, cysteamine (50 μm), melatonin (10 ng/mL) and cysteamine (50 μm) + melatonin (10 ng/mL) treatment groups. In experiment 1, previous treatments were added duringin vitromaturation and culturing of buffalo ***:Cleavage and blastocyst rates were significantly (Pmelatonin treated group (70.5±0.9 and 12.8±1.0, respectively). However this effect was potentiated when combined with cysteamine (74.0±1.7 and 14.8±1.7, respectively). In experiment 2, the treatements were added in maturtaion, culturing as well as post-warming culture media. Embryos at 7 d were *** assessement directly after warming showed significant increase (Pmine, melatonin and their combination groups (76.8±2.8, 80.0±2.1 and 83.3±1.7, respectively) than control (65.8±2.4);but the viability after 24 h post-warming was the best in cysteamine + melatonin combination group (61.4±2.1).Conculsions: Enriching maturation, culturing and post-warming media of buffalo oocytes and embryos with melatonin and/or cysteamine have significantly beneficial effects on oocyte developmental competence as well as embryos vitrification procedure outcomes which in turn resulting in enhancement of commercial buffalo embryo production.

关键词： melatonin Cysteamine Buffalo Oocyte maturation Vitrification

Chaotic and Hyperchaotic Complex Jerk Equations

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International Journal of modern Nonlinear Theory and Application 2012年第1期1卷 6-13页

作者： gamal m. mahmoud mansour E. Ahmed Department of mathematics Faculty of Science Assiut University Assiut Egypt

The aim of this paper is to introduce and investigate chaotic and hyperchaotic complex jerk equations. The jerk equations describe various phenomena in engineering and physics, for example, electrical circuits, laser physics, mechanical oscillators, damped harmonic oscillators, and biological systems. Properties of these systems are studied and their Lyapunov exponents are calculated. The dynamics of these systems is rich in wide range of systems parameters. The control of chaotic attractors of the complex jerk equation is investigated. The Lyapunov exponents are calculated to show that the chaotic behavior is converted to regular behavior.

关键词： Hyperchaotic Chaotic Attractors Lyapunov Exponents Jerk Function Control Complex

Kumaraswamy Inverted Topp–Leone Distribution with Applications to COVID-19 Data

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Computers, materials & Continua 2021年第7期68卷 337-358页

作者： Amal S.Hassan Ehab m.Almetwally gamal m.Ibrahim Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza12613Egypt Faculty of Business Administration Delta University of Science and TechnologyMansoura35511Egypt High Institute for management Sciences Belqas35511Egypt

In this paper, an attempt is made to discover the distributionof COVID-19 spread in different countries such as;Saudi Arabia, Italy,Argentina and Angola by specifying an optimal statistical distribution for analyzing the mortality rate of COVID-19. A new generalization of the recentlyinverted Topp Leone distribution, called Kumaraswamy inverted Topp–Leonedistribution, is proposed by combining the Kumaraswamy-G family and theinverted Topp–Leone distribution. We initially provide a linear representationof its density function. We give some of its structure properties, such as quantile function, median, moments, incomplete moments, Lorenz and Bonferronicurves, entropies measures and stress-strength reliability. Then, Bayesian andmaximum likelihood estimators for parameters of the Kumaraswamy invertedTopp–Leone distribution under Type-II censored sample are *** estimator is regarded using symmetric and asymmetric loss functions. As analytical solution is too hard, behaviours of estimates have beendone viz monte Carlo simulation study and some reasonable comparisonshave been presented. The outcomes of the simulation study confirmed theefficiencies of obtained estimates as well as yielded the superiority of Bayesianestimate under adequate priors compared to the maximum likelihood *** to COVID-19 in some countries showed that the new distributionis more appropriate than some other competitive models.

关键词： Kumaraswamy-G family maximum likelihood Bayesian method COVID-19 moments quantile function stress-strength reliability

Effect of using ascorbic acid and cysteamine supplementation onin-vitrodevelopment of buffalo embryos

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Asian pacific Journal of Reproduction 2017年第2期6卷 85-88页

作者： Al-shimaa Al-H.H.El-Naby Karima Gh.m.mahmoud gamal A.m.Sosa mahmoud E.A.Abouel-Roos Youssef F.Ahmed Department of Theriogenology Faculty of Veterinary MedicineBenha UniversityEgypt Department of Animal Reproduction and A.I. National Research CenterDokkiGizaEgypt

Objective:To improvein vitro embryo production in buffalo by supplementation of L-ascorbic acid during maturation and development (experiment 1) and combination with another antioxidant as cysteamine (experiment 2).methods:Two experiments were performed, the first one aimed to evaluate the different concentrations (0, 25, 50, 100 μm) of L-ascorbic acid on embryo developmental rate of buffalo oocytes. The L-ascorbic acid was added to the maturation and culture media. In the second experiment, oocytes were cultured in media with two type of antioxidant (ascorbic acid + cysteamine) or ascorbic acid ***:There was a significant increase in cleavage rate at 25, 50 μm than 100 μm and control group. But, the blastocyst rate was higher at 50 μm ascorbic acid than other concentrations (0, 25, 100 μm). Supplementation of ascorbic acid and cysteamine to maturation and cultured media improved embryo development than ascorbic acid ***: Using of 50 μm L-ascorbic acid duringin vitro maturation and development improve the developmental competence of buffalo oocytes, this effect was increase with the presence of cysteamine.

关键词： Buffalo Oocytes L-ascorbic acid Cysteamine Embryo development

Regular Charged Solutions in mφller＇s Tetrad Theory of Gravitation

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Chinese Physics Letters 2007年第11期24卷 3059-3062页

作者： gamal G. L. Nashed Department of mathematics Faculty of Science Ain Shams University Cairo Egypt

We find the most general tetrads which give a regular charged spacetime in tetrad theory of gravitation. The metric is a static one and it includes the Schwarzschild and Fteissner Nordstrom black holes. The energy content contained in a sphere of radius R is calculated using the superpotential given by mφller in the context of Weitzenbock spacetime.

关键词： Regular Charged Solutions Tetrad Gravitation