oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 9 )

2019 ( 618 )

2018 ( 719 )

2017 ( 704 )

Custom range...

Search Results: 1 - 10 of 402242 matches for " Ashraf M. Abdelbar "
All listed articles are free for downloading (OA Articles)
Page 1 /402242
Display every page Item
Alpha-Beta Pruning and Alth?fer’s Pathology-Free Negamax Algorithm
Ashraf M. Abdelbar
Algorithms , 2012, DOI: 10.3390/a5040521
Abstract: The minimax algorithm, also called the negamax algorithm, remains today the most widely used search technique for two-player perfect-information games. However, minimaxing has been shown to be susceptible to game tree pathology, a paradoxical situation in which the accuracy of the search can decrease as the height of the tree increases. Alth?fer’s alternative minimax algorithm has been proven to be invulnerable to pathology. However, it has not been clear whether alpha-beta pruning, a crucial component of practical game programs, could be applied in the context of Alh?fer’s algorithm. In this brief paper, we show how alpha-beta pruning can be adapted to Alth?fer’s algorithm.
Rotating Variable-Thickness Inhomogeneous Cylinders: Part I—Analytical Elastic Solutions  [PDF]
Ashraf M. Zenkour
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.16063
Abstract: In this paper, an analytical solution for the rotation problem of an inhomogeneous hollow cylinder with variable thickness under plane strain assumption is developed. The present cylinder is made of a fiber-reinforced viscoelastic inhomogeneous orthotropic material. The thickness of the cylinder is taken as parabolic function in the radial direction. The elastic properties varies in the same manner as the thickness of the cylinder while the density varies according to an exponential law form. The inner and outer surfaces of the cylinder are considered to have combinations of free and clamped boundary conditions. Analytical solutions are given according to different types of the hollow cylinders. An extension of the present solutions to the viscoelastic ones and some applications are investigated in Part II.
Rotating Variable-Thickness Inhomogeneous Cylinders: Part II—Viscoelastic Solutions and Applications  [PDF]
Ashraf M. Zenkour
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.16064
Abstract: Analytical solutions for the rotating variable-thickness inhomogeneous, orthotropic, hollow cylinders under plane strain assumption are developed in Part I of this paper. The extensions of these solutions to the viscoelastic case are discussed here. The method of effective moduli and Illyushin's approximation method are used for this purpose. The rotating fiber-reinforced viscoelastic homogeneous isotropic hollow cylinders with uniform thickness are obtained as special cases of the studied problem. Numerical application examples are given for the dimensionless displacement of and stresses in the different cylinders. The influences of time, constitutive parameter and elastic properties on the stresses and displacement are investigated.
Physical Properties of Lithium Containing Cadmium Phosphate Glasses  [PDF]
Muhammad Altaf, M. Ashraf Chaudhry
Journal of Modern Physics (JMP) , 2010, DOI: 10.4236/jmp.2010.14030
Abstract: Lithium cadmium phosphate glasses were prepared by melt quench technique. These glasses contain a mole % composition of x% Li2O-(50-x)% CdO-50%P2O5. The quantity x varies from 0-40 mole%. The physical properties reported in this paper are mass density ρ, modulus of rigidity η, coefficient of linear expansion α, transition temperature Tg, Softening temperature Ts, Oxygen packing density, Molar volume and lithium ion concentration. The mass density, oxygen packing density, modulus rigidity, transition temperature and softening temperature show decreasing trend with increasing concentration of lithium ions in these glasses, where molar volume and coefficient of linear expansion increases with increasing concentration of Li2O.
Simulation of Diode-Pumped Q-Switched Nd:YAG Laser Generating Eye-Safe Signal in IOPO Environment  [PDF]
Mian M. Ashraf, Muhammad Siddique
Optics and Photonics Journal (OPJ) , 2012, DOI: 10.4236/opj.2012.23025
Abstract: Numerical simulation of diode-pumped Q-switched Nd:YAG laser leading to the generation of eye-safe signal in singly resonant Intracavity Optical Parametric Oscillator (IOPO) is presented. Starting from rate equations, the time dependent laser equations have been solved numerically, whereas the space-dependent OPO equations analytically. Our results show that 1.4 J diode laser (810 nm) pulse with 200 msec width, delivers 30 mJ Nd:YAG laser (1064 nm) pulse with 5 n-second width. This Nd:YAG laser further generates 9 mJ eye safe signal (1570 nm) pulse with 2.5 n-second width.
Flash Flood Risk Assessment Using Morphological Parameters in Sinai Peninsula  [PDF]
Ashraf M. Elmoustafa, Mona M. Mohamed
Open Journal of Modern Hydrology (OJMH) , 2013, DOI: 10.4236/ojmh.2013.33016
Abstract: Flash floods are considered to be one of the worst weather-related natural disasters. They are sudden and highly unpredictable following brief spells of heavy rain. Egypt is subjected to flash floods, especially the eastern desert and Sinai Peninsula where floods from the mountains of Red Sea and Sinai are causing heavy damage to man-made features. This manuscript presents the methodology adopted to generate a weighted risk map for main watersheds located in Sinai according to main morphological parameters. Using digital elevation model (DEM) implemented into a Geographic Information System (GIS) the Sinai watersheds were delineated and morphological parameters calculated. The parameters where then used in a multi criteria analysis process to calculate a morphological risk factor. The resulted risk maps of this study can help initiating appropriate measures to mitigate the probable hazards in the area with prioritization.
Thermal buckling analysis of ceramic-metal functionally graded plates  [PDF]
Ashraf M. Zenkour, Daoud S. Mashat
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.29118
Abstract: Thermal buckling response of functionally graded plates is presented in this paper using sinusoidal shear deformation plate theory (SPT). The material properties of the plate are assumed to vary according to a power law form in the thickness direction. Equilibrium and stability equations are derived based on the SPT. The non-linear governing equations are solved for plates subjected to simply supported boundary conditions. The buckling analysis of a functionally graded plate under various types of thermal loads is carried out. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the SPT, demonstrating its importance and accuracy in comparison to other theories.
Analytical and Numerical Solutions for a Rotating Annular Disk of Variable Thickness  [PDF]
Ashraf M. Zenkour, Daoud S. Mashat
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.15057
Abstract: In this paper, the analytical and numerical solutions for rotating variable-thickness solid disk and numerical solution for rotating variable-thickness annular disk are presented. The outer edge of the solid disk and the inner and outer edges of the annular disk are considered to have clamped boundary conditions. Two different cases for the radially varying thickness of the solid and annular disks are given. The numerical solution as well as the analytical solution is available for the first case of the solid disk while the analytical solution is not available for the second case of the annular disk. Both analytical and numerical results for displacement and stresses will be investigated for the first case of radially varying thickness. The accuracy of the present numerical solution is discussed and its ability of use for the second case of radially varying thickness is investigated. Finally, the distributions of displacement and stresses will be presented and the appropriate comparisons and discussions are made at the same angular velocity.
Stress Function of a Rotating Variable-Thickness Annular Disk Using Exact and Numerical Methods  [PDF]
Ashraf M. Zenkour, Daoud S. Mashat
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.34048
Abstract: In this paper, the exact analytical and numerical solutions for rotating variable-thickness annular disk are presented. The inner and outer edges of the rotating variable-thickness annular disk are considered to have free boundary conditions. Two different annular disks for the radially varying thickness are given. The numerical Runge-Kutta solution as well as the exact analytical solution is available for the first disk while the exact analytical solution is not available for the second annular disk. Both exact and numerical results for stress function, stresses, strains and radial displacement will be investigated for the first annular disk of variable thickness. The accuracy of the present numerical solution is discussed and its ability of use for the second rotating variable-thickness annular disk is investigated. Finally, the distributions of stress function, displacement, strains, and stresses will be presented. The appropriate comparisons and discussions are made at the same angular velocity.
Thermal buckling analysis of ceramic-metal functionally graded plates  [PDF]
Ashraf M. Zenkour,Daoud S. Mashat
Natural Science (NS) , 2010, DOI: 10.4236/ns.2009.29118
Abstract: Thermal buckling response of functionally graded plates is presented in this paper using sinusoidal shear deformation plate theory (SPT). The material properties of the plate are assumed to vary according to a power law form in the thickness direction. Equilibrium and stability equations are derived based on the SPT. The non-linear governing equations are solved for plates subjected to simply supported boundary conditions. The buckling analysis of a functionally graded plate under various types of thermal loads is carried out. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the SPT, demonstrating its importance and accuracy in comparison to other theories.
Page 1 /402242
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.