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Phenomenological Model for the Maximum Mass of a Rotating Magnetized Neutron Star 认领 引用
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作者 Abbas Al-Faouri Ali Taani Mohammed Abu-Saleem 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2026年第3期182-191,共10页
We present a refined phenomenological relation for estimating the critical mass of a neutron star(NS),accounting for both rotation and magnetic helicity effects.This model is analyzed to confirm agreement with recogni... We present a refined phenomenological relation for estimating the critical mass of a neutron star(NS),accounting for both rotation and magnetic helicity effects.This model is analyzed to confirm agreement with recognized universal relations,constrained based on observations from both gravitational wave and electromagnetic sources,and results of surface deformation derived using X-ray pulse modeling add dependencies involving the moment of inertia and compactness.Our model builds on the classical static Tolman-Oppenheimer-Volkoff limit by adding important physical effects:centrifugal pressure from rapid spin combined with magneto-superfluid effects that display magnetic helicity in the NS core and deformation of the stellar surface resulting from high rotational spin rates.The model accurately reproduces key numerical results as seen in the quasi-universal relation Mmax≈(1.203±0.022)MTOV for configurations with maximum rotation.This refined approach leads to a gentle,flexible tool for estimating critical masses and interpreting observational data for rotating systems and magnetized compact stars,where it contributes to ongoing analytical and numerical developments in relativistic astrophysics. 展开更多
关键词 (galaxies:)quasars general-(galaxies:)quasars emission lines-galaxies active-galaxies highredshift
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Nonlinear Post-Buckling Stability of Graphene Origami-Enabled Auxetic Metamaterials Plates 认领 引用 被引量：1
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作者 Salwa A.Mohamed Mohamed A.Eltaher +1 位作者 Nazira Mohamed Rasha Abo-bakr 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第4期515-538,共24页
The nonlinear post-buckling response of functionally graded(FG)copper matrix plates enforced by graphene origami auxetic metamaterials(GOAMs)is investigated in the currentwork.The auxeticmaterial properties of the pla... The nonlinear post-buckling response of functionally graded(FG)copper matrix plates enforced by graphene origami auxetic metamaterials(GOAMs)is investigated in the currentwork.The auxeticmaterial properties of the plate are controlled by graphene content and the degree of origami folding,which are graded across the thickness of the plate.Thematerial properties of the GOAM plate are evaluated using genetic micro-mechanicalmodels.Governing nonlinear eigenvalue problems for the post-buckling response of the GOAM composite plate are derived using the virtual work principle and a four-variable nonlinear shear deformation theory.A novel differential quadrature method(DQM)algorithm is developed to solve the nonlinear eigenvalue problem.Detailed parametric studies are presented to explore the effects of graphene content,folding degree,and GO distribution patterns on the post-buckling responses of GOAM plates.Results show that high tunability in post-buckling characteristics can be achieved by using GOAM.FunctionallyGradedGraphene OrigamiAuxeticMetamaterials(FG-GOAM)plates can be used in aerospace structures to improve their structural performance and response. 展开更多
关键词 Postbuckling nonlinear stability auxetic metamaterials higher order plate DQM numerical solution
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Suzuki-Type(μ,v)-Weak Contraction for the Hesitant Fuzzy Soft Set Valued Mappings with Applications in Decision Making 认领 引用
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作者 Muhammad Sarwar Rafiq Alam +2 位作者 Kamaleldin Abodayeh Saowaluck Chasreechai Thanin Sitthiwirattham 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第5期2213-2236,共24页
In this manuscript,the notion of a hesitant fuzzy soft fixed point is introduced.Using this notion and the concept of Suzuki-type(μ,ν)-weak contraction for hesitant fuzzy soft set valued-mapping,some fixed point res... In this manuscript,the notion of a hesitant fuzzy soft fixed point is introduced.Using this notion and the concept of Suzuki-type(μ,ν)-weak contraction for hesitant fuzzy soft set valued-mapping,some fixed point results are established in the framework of metric spaces.Based on the presented work,some examples reflecting decision-making problems related to real life are also solved.The suggested method’s flexibility and efficacy compared to conventional techniques are demonstrated in decision-making situations involving uncertainty,such as choosing the best options in multi-criteria settings.We noted that the presented work combines and generalizes two major concepts,the idea of soft sets and hesitant fuzzy set-valued mapping from the existing literature. 展开更多
关键词 Hesitant fuzzy soft set valued mapping Suzuki-type(μ,ν)-weak contraction fixed point decision making problem
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ON THE EXISTENCE AND STABILITY OF BOUNDARY VALUE PROBLEM FOR DIFFERENTIAL EQUATION WITH HILFER-KATUGAMPOLA FRACTIONAL DERIVATIVE 认领 引用 被引量：3
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作者 E.M.ELSAYED S.HARIKRISHNAN K.KANAGARAJAN 《Acta Mathematica Scientia》 SCIE CSCD 2019年第6期1568-1578,共11页
In this paper, we discuss the existence, uniqueness and stability of boundary value problem for differential equation with Hilfer-Katugampola fractional derivative. The arguments are based upon Schaefer's fixed po... In this paper, we discuss the existence, uniqueness and stability of boundary value problem for differential equation with Hilfer-Katugampola fractional derivative. The arguments are based upon Schaefer's fixed point theorem, Banach contraction principle and Ulam type stability. 展开更多
关键词 Hilfer-Katugampola fractional derivative boundary condition existence Ulam stability
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Dynamics of a multi-mode maximum entangled coherent state over an amplitude damping channel 认领 引用 被引量：1
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作者 A.El Allati Y.Hassouni N.Metwally 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期67-73,共7页
The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the traveling state is very fragile to this noise chann... The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated. For small values of the transmissivity rate, the traveling state is very fragile to this noise channel, which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the traveling state over this noise channel quickly loses its entanglement. The odd and even states vanish at the same value of field intensity. 展开更多
关键词 entanglement quantum communication decoherence coherent states
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State-space approach to vibration of gold nano-beam induced by ramp type heating 认领 引用 被引量：1
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作者 Hamdy M.Youssef Khaled A.Elsibai 《Nano-Micro Letters》 SCIE EI CAS 2010年第3期139-147,共9页
In the nanoscale beam,two effects become domineering.One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate.In the present study,a generalized solutio... In the nanoscale beam,two effects become domineering.One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate.In the present study,a generalized solution for the generalized thermoelastic vibration of gold nano-beam resonator induced by ramp type heating is developed.The solution takes into account the above two effects.State-space and Laplace transform methods are used to determine the lateral vibration,the temperature,the displacement,the stress and the strain energy of the beam.The effects of the relaxation time and the ramping time parameters have been studied. 展开更多
关键词 Thermoelasticity Euler-Bernoulli equation Gold nano-beam Ramp type heating
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Metaheuristic Lightweight Cryptography for Security Enhancement in Internet of Things 认领 引用 被引量：1
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作者 Mahmoud Ragab Ehab Bahaudien Ashary 《Computers, Materials & Continua》 SCIE EI 2022年第8期3009-3023,共15页
The advancements made in Internet of Things(IoT)is projected to alter the functioning of healthcare industry in addition to increased penetration of different applications.However,data security and private are challen... The advancements made in Internet of Things(IoT)is projected to alter the functioning of healthcare industry in addition to increased penetration of different applications.However,data security and private are challenging tasks to accomplish in IoT and necessary measures to be taken to ensure secure operation.With this background,the current paper proposes a novel lightweight cryptography method for enhance the security in IoT.The proposed encryption algorithm is a blend of Cross Correlation Coefficient(CCC)and Black Widow Optimization(BWO)algorithm.In the presented encryption technique,CCC operation is utilized to optimize the encryption process of cryptography method.The projected encryption algorithm works in line with encryption and decryption processes.Optimal key selection is performed with the help of Artificial Intelligence(AI)tool named BWO algorithm.With the combination of AI technique and CCC operation,optimal security operation is improved in IoT.Using different sets of images collected from databases,the projected technique was validated in MATLAB on the basis of few performance metrics such as encryption time,decryption time,Peak Signal to Noise Ratio(PSNR),CC,Error,encryption time and decryption time.The results were compared with existing methods such as Elliptical Curve cryptography(ECC)and Rivest-Shamir-Adleman(RSA)and the supremacy of the projected method is established. 展开更多
关键词 Security images encryption time correlation coefficient black widow optimization artificial intelligence decryption time
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On the Application of the Adomian’s Decomposition Method to a Generalized Thermoelastic Infinite Medium with a Spherical Cavity in the Framework Three Different Models 认领 引用 被引量：1
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作者 Najat A.Alghamdi Hamdy M.Youssef 《Fluid Dynamics & Materials Processing》 EI 2019年第5期597-611,共15页
A mathematical model is elaborated for a thermoelastic infinite body with a spherical cavity.A generalized set of governing equations is formulated in the context of three different models of thermoelasticity:the Biot... A mathematical model is elaborated for a thermoelastic infinite body with a spherical cavity.A generalized set of governing equations is formulated in the context of three different models of thermoelasticity:the Biot model,also known as“coupled thermoelasticity”model;the Lord-Shulman model,also referred to as“generalized thermoelasticity with one-relaxation time”approach;and the Green-Lindsay model,also called“generalized thermoelasticity with two-relaxation times”approach.The Adomian’s decomposition method is used to solve the related mathematical problem.The bounding plane of the cavity is subjected to harmonic thermal loading with zero heat flux and strain.Numerical results for the temperature,radial stress,strain,and displacement are represented graphically.It is shown that the angular thermal load and the relaxation times have significant effects on all the studied fields. 展开更多
关键词 Adomian’s decomposition method generalized thermoelasticity relaxation time iteration method
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Nonlinear electrodynamics coupled to teleparallel theory of gravity 认领 引用 被引量：1
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第2期73-82,共10页
Using nonlinear electrodynamics coupled to teleparallel theory of gravity, regular charged spherically symmetric solutions are obtained. The nonlinear theory is reduced to the Maxwell one in the weak limit and the sol... Using nonlinear electrodynamics coupled to teleparallel theory of gravity, regular charged spherically symmetric solutions are obtained. The nonlinear theory is reduced to the Maxwell one in the weak limit and the solutions correspond to charged spacetimes. One of the obtained solutions contains an arbitrary function which we call general solution since we can generate from it the other solutions. The metric associated with these spacetimes is the same, i.e., regular charged static spherically symmetric black hole. In calculating the energy content of the general solution using the gravitational energy momentum within the framework of the teleparallel geometry, we find that the resulting form depends on the arbitrary function. Using the regularized expression of the gravitational energy-momentum we obtain the value of energy. 展开更多
关键词 tetrad theory of gravitation nonlinear electrodynamics spherically symmetric black holes gravitational energy-momentum
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Energy and spatial momentum of charged rotating frames in tetrad gravity 认领 引用 被引量：1
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期90-101,共12页
We compute the total energy and the spatial momentum of four charged rotating （Kerr-Newman） frames by using the gravitational energy-momentum 3-form within the framework of the tetrad formulation of the general rela... We compute the total energy and the spatial momentum of four charged rotating （Kerr-Newman） frames by using the gravitational energy-momentum 3-form within the framework of the tetrad formulation of the general relativity theory. We show how the effect of the inertial always makes the total energy divergent. We use a natural regularization method, which yields the physical value for the total energy of the system. We show how the regularization method works on a number of different rotating frames that are related to each other by the local Lorentz transformation. We also show that the inertial has no effect on the spatial momentum components. 展开更多
关键词 teleparallel gravity energy-momentum Weitzenbock connection regularization teleparallelism
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Spherically symmetric solution in higher-dimensional teleparallel equivalent of general relativity 认领 引用 被引量：1
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期120-127,共8页
A theory of（N＋1）-dimensional gravity is developed on the basis of the teleparallel equivalent of general relativity（TEGR）.The fundamental gravitational field variables are the（N＋1）-dimensional vector fields,de... A theory of（N＋1）-dimensional gravity is developed on the basis of the teleparallel equivalent of general relativity（TEGR）.The fundamental gravitational field variables are the（N＋1）-dimensional vector fields,defined globally on a manifold M,and the gravitational field is attributed to the torsion.The form of Lagrangian density is quadratic in torsion tensor.We then give an exact five-dimensional spherically symmetric solution（Schwarzschild（4＋1）-dimensions）.Finally,we calculate energy and spatial momentum using gravitational energy-momentum tensor and superpotential 2-form. 展开更多
关键词 （N＋1）-dimensional teleparallel equivalent of general relativity five-dimensional solution energy and momentum
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Spherically Symmetric Solutions on a Non-Trivial Frame in f(T) Theories of Gravity 认领 引用 被引量：1
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作者 Gamal G.L.Nashed 《Chinese Physics Letters》 SCIE EI CAS CSCD 2012年第5期37-40,共4页
A new solution with constant torsion is derived using the field equations of f(T).Asymptotic forms of energy density,radial and transversal pressures are shown to meet the standard energy conditions,i.e.,weak and '... A new solution with constant torsion is derived using the field equations of f(T).Asymptotic forms of energy density,radial and transversal pressures are shown to meet the standard energy conditions,i.e.,weak and 'null' energy conditions according to some restrictions on T0,f(T0) and fT(T0). Other solutions are obtained for vanishing radial pressure and for specific choices of f(T).The physics relevant to the resulting models is discussed. 展开更多
关键词 radial torsion vanishing
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Energy and momentum of rotating frames in tetrad gravity 认领 引用 被引量：1
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作者 Gamal G L Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期101-111,共11页
Within the framework of the tetrad formulation of general relativity theory, we compute the total energy and momentum of four rotating frames using the gravitational energy-momentum 3-form. We show how the effect of i... Within the framework of the tetrad formulation of general relativity theory, we compute the total energy and momentum of four rotating frames using the gravitational energy-momentum 3-form. We show how the effect of inertia always makes the total energy divergent. We use a natural regularization method to obtain physical values for the total energy of the system and show how it works on a number of explicit examples. We also show by calculation that inertia has no effect on the momentum components. 展开更多
关键词 teleparallel gravity, energy-momentum WeitzenbSck connection, regularization telepar-allelism
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Entanglement of the Thermal State of an Anisotropic XYZ Spin Chain in an Inhomogeneous Constant Magnetic Field 认领 引用
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作者 A.-S.F.Obada G.M.Abd Al-Kadar +1 位作者 F.K.Faramawy A.A.Youssef 《Chinese Physics Letters》 SCIE EI CAS CSCD 2012年第3期9-12,共4页
A system of a two-qubit Heisenberg anisotropic XYZ spin chain in an inhomogeneous constant magnetic field with the Dzyaloshinskii-Moriya interaction is studied.The energy eigenvalues,the corresponding eigenstates and ... A system of a two-qubit Heisenberg anisotropic XYZ spin chain in an inhomogeneous constant magnetic field with the Dzyaloshinskii-Moriya interaction is studied.The energy eigenvalues,the corresponding eigenstates and the thermal states of the system are evaluated.The entanglement is investigated according to Wootter's concurrence.The concurrence is studied against temperature for different values of the parameters involved. 展开更多
关键词 system concurrence states
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Mathematical Modelling of Quantum Kernel Method for Biomedical Data Analysis 认领 引用
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作者 Mahmoud Ragab Ehab Bahauden Ashary +2 位作者 Maha Farouk S.Sabir Adel A.Bahaddad Romany F.Mansour 《Computers, Materials & Continua》 SCIE EI 2022年第6期5441-5457,共17页
This study presents a novelmethod to detect themedical application based on Quantum Computing(QC)and a few Machine Learning(ML)systems.QC has a primary advantage i.e.,it uses the impact of quantum parallelism to provi... This study presents a novelmethod to detect themedical application based on Quantum Computing(QC)and a few Machine Learning(ML)systems.QC has a primary advantage i.e.,it uses the impact of quantum parallelism to provide the consequences of prime factorization issue in a matter of seconds.So,this model is suggested for medical application only by recent researchers.A novel strategy i.e.,Quantum KernelMethod(QKM)is proposed in this paper for data prediction.In this QKM process,Linear Tunicate Swarm Algorithm(LTSA),the optimization technique is used to calculate the loss function initially and is aimed at medical data.The output of optimization is either 0 or 1 i.e.,odd or even in QC.From this output value,the data is identified according to the class.Meanwhile,the method also reduces time,saves cost and improves the efficiency by feature selection process i.e.,Filter method.After the features are extracted,QKM is deployed as a classification model,while the loss function is minimized by LTSA.The motivation of the minimal objective is to remain faster.However,some computations can be performed more efficiently by the proposed model.In testing,the test data was evaluated by minimal loss function.The outcomes were assessed in terms of accuracy,computational time,and so on.For this,databases like Lymphography,Dermatology,and Arrhythmia were used. 展开更多
关键词 Medical data classification feature selection qkm classifier ltsa optimization
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Conserved charges of Kerr-Ads spacetime using Poincaré gauge version 认领 引用 被引量：1
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作者 Gamal G. L. Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第12期96-103,共8页
The process of covariant conserved charge of gravitational theory, which is covariant under general coordinate and local Lorentz transformations, has been applied to many tetrad fields, which reproduce Kerr-Ads spacet... The process of covariant conserved charge of gravitational theory, which is covariant under general coordinate and local Lorentz transformations, has been applied to many tetrad fields, which reproduce Kerr-Ads spacetime, to calculate their conserved charges. It is shown that this process gives an infinite value of the conserved charges for Kerr–Ads spacetime. Therefore, the method of “regularization through relocalization”, i.e., modification of the Lagrangian of the gravitational field through a total derivative, is used. This method gaves a finite and a consistent result of total energy and angular momentum for Kerr–Ads spacetime. 展开更多
关键词 Kerr–Ads spacetimes total conserved charges Poincaré gauge version
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Plane Vibrations in a Transversely Isotropic Infinite Hollow Cylinder Under Effect of the Rotation and Magnetic Field 认领 引用
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作者 F.S.Bayones A.M.Abd-Alla 《Computer Modeling in Engineering & Sciences》 SCIE EI 2017年第2期151-170,共20页
The aim of this paper is to study the effects of rotation and magnetic field on the plane vibrations in a transversely isotropic material of an infinite hollow cylinder.The natural frequency of the plane vibrations in... The aim of this paper is to study the effects of rotation and magnetic field on the plane vibrations in a transversely isotropic material of an infinite hollow cylinder.The natural frequency of the plane vibrations in the case of harmonic vibrations has been obtained.The natural frequencies are calculated numerically and the effects of rotation and magnetic field are discussed.The numerical results obtained have been illustrated graphically to understand the behavior of frequency equation with different values of frequencyωunder effects the rotation and magnetic field.Comparison was made with the results obtained in the presence and absence of the rotation and magnetic field.The results indicate that the effect of rotation and magnetic field are very pronounced. 展开更多
关键词 Plane transversely isotropic rotating magnetic field homogeneous transversely isotropic Natural frequencies
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A Blockchain-Based Architecture for Enabling Cybersecurity in the Internet-of-Critical Infrastructures 认领 引用
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作者 Mahmoud Ragab Ali Altalbe 《Computers, Materials & Continua》 SCIE EI 2022年第7期1579-1592,共14页
Due to the drastic increase in the number of critical infrastructures like nuclear plants,industrial control systems(ICS),transportation,it becomes highly vulnerable to several attacks.They become the major targets of... Due to the drastic increase in the number of critical infrastructures like nuclear plants,industrial control systems(ICS),transportation,it becomes highly vulnerable to several attacks.They become the major targets of cyberattacks due to the increase in number of interconnections with other networks.Several research works have focused on the design of intrusion detection systems(IDS)using machine learning(ML)and deep learning(DL)models.At the same time,Blockchain(BC)technology can be applied to improve the security level.In order to resolve the security issues that exist in the critical infrastructures and ICS,this study designs a novel BC with deep learning empowered cyber-attack detection(BDLE-CAD)in critical infrastructures and ICS.The proposed BDLE-CAD technique aims to identify the existence of intrusions in the network.In addition,the presented enhanced chimp optimization based feature selection(ECOA-FS)technique is applied for the selection of optimal subset of features.Moreover,the optimal deep neural network(DNN)with search and rescue(SAR)optimizer is applied for the detection and classification of intrusions.Furthermore,a BC enabled integrity checking scheme(BEICS)has been presented to defend against the misrouting attacks.The experimental result analysis of the BDLE-CAD technique takes place and the results are inspected under varying aspects.The simulation analysis pointed out the supremacy of the BDLE-CAD technique over the recent state of art techniques with the accuy of 92.63%. 展开更多
关键词 BC internet of critical infrastructure ids deep learning security deep neural network machine learning
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Gravitational collapse with standard and dark energy in the teleparallel equivalent of general relativity 认领 引用
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期57-62,共6页
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 energ... 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. 展开更多
关键词 perfect fluid with self-similarity of second kind teleparallel equivalent of general relativ-ity asymptotically nonflat spacetime energy conditions
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Energy and momentum of general spherically symmetric frames on the regularizing teleparallelism 认领 引用
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作者 Gamal G.L.Nashed 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期101-109,共9页
In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary ... In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary function H（r）, which preserves the spherical symmetry and reproduces all the previous solutions, while the other one is characterized by a parameter ξ which ensures the vanishing of the axial of trace of the torsion. We calculate the total energy by using two procedures, i.e., when the WeitzenbSck connection Гα^β is trivial, and show how H（r） and ξ play the role of an inertia that leads the total energy to be unphysical. Therefore, we take into account Гα^β and show that although the spacetimes we use contain an arbitrary function and one parameter, they have no effect on the form of the total energy and momentum as it should be. 展开更多
关键词 gravitation teleparallel gravity energy-momentum conserved currents
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