Research ArticleOpen accessIn the abstractOn the Pseudo-Spectral Method of Solving Linear Ordinary Differential EquationsB. S. OgundareProblem statement: Not all differential equations can be solved analytically, to overcome this problem, there is need to search for an accurate approximate solution. Approach: The objective of this study was to find an accurate approximation technique (scheme) for solving linear differential equations. By exploiting the Trigonometric identity property of the Chebyshev polynomial, we developed a numerical scheme referred to … …Journal of Mathematics and Statistics, Vol. 5, Issue 2 · 30 Jun 2009 · 7,222 accessesView PDFCite
Research ArticleOpen accessIn the abstractOn Strongly Coupled Linear Elliptic Systems with Application to Otolith Membrane DistortionI.K. YoussefProblem Statement: In this research, the author discussed the problems associated with the approximation of the mixed derivative terms appearing in strongly coupled linear elliptic systems by the finite difference method over irregular domains. To avoid the appearance of mixed derivative terms the author introduced a reformulation for the system through introducing a new dependent variable which adds one supplementary … …Journal of Mathematics and Statistics, Vol. 4, Issue 4 · 31 Dec 2008 · 6,714 accessesView PDFCite
Research ArticleOpen accessIn the abstractNumerical Comparison of Thermal Stratification due Natural Convection in Densified LOX, LN2 TanksSeyed Ali Jazayeri, Ehsan Molla Hasanzadeh KhoeiThe growth of natural circulation and thermal stratification inside LOX, LN2 storage tanks due to heat transfer from surroundings is investigated using a non-equilibrium, two-domain, mathematical model. The two-dimensional model is considered for the liquid domain in two cases and a lumped, thermodynamic model is utilized for vapor domain. The vapor is assumed to behave like an ideal gas. The … …American Journal of Applied Sciences, Vol. 5, Issue 12 · 31 Dec 2008 · 6,967 accessesView PDFCite
Research ArticleOpen accessIn the abstractDynamic Analysis of Structures Using Neural NetworksN. Ahmadi, R. Kamyab Moghadas, A. LavaeiIn the recent years, neural networks are considered as the best candidate for fast approximation with arbitrary accuracy in the time consuming problems. Dynamic analysis of structures against earthquake has the time consuming process. We employed two kinds of neural networks: Generalized Regression neural network (GR) and Back-Propagation Wavenet neural network (BPW), for approximating of dynamic time history response of … …American Journal of Applied Sciences, Vol. 5, Issue 9 · 30 Sep 2008 · 7,154 accessesView PDFCite
Research ArticleOpen accessIn the abstractOptimized Set of RST Moment InvariantsKhalid M. HosnyMoment invariants are widely used in image processing, pattern recognition and computer vision. Several methods and algorithms have been proposed for fast and efficient calculation of moment's invariants where numerical approximation errors are involved in most of these methods. In this paper, an optimized set of moment invariants with respect to rotation, scaling and translation is presented. An accurate method … …American Journal of Applied Sciences, Vol. 5, Issue 6 · 30 Jun 2008 · 7,069 accessesView PDFCite
Research ArticleOpen accessIn the abstractElectronic Energies in Delta Doped AlGaAs/GaAs HeterostucturesA. Meftah, H. Ajlani, A. Marzouki et al.The band bending of the potential at the AlGaAs/GaAs interface increases with the electrons concentration in the GaAs channel. This band bending is often ignored in the theoretical calculation of the electronic energies and a linear potential approximation was used. This led to imprecise energy values and occupied subband configurations. We have taken account of the band bending in the … …American Journal of Applied Sciences, Vol. 5, Issue 4 · 30 Apr 2008 · 6,931 accessesView PDFCite
Research ArticleOpen accessIn the abstractClosed Die Forging Geometrical Parameters Optimization for Al-MMCM. Jolgaf, S.B. Sulaiman, M.K.A Ariffin, A.A. FaiezaDemand for lighter and stiffer products has been increasing in the last few years especially in automobile manufacturing. The closed die forging process of Metal Matrix Material (MMC) is presented as possible solution, since it produces parts with good mechanical properties and lighter weight. A computational modeling of closed die forging process using finite element method and optimization techniques makes … …American Journal of Engineering and Applied Sciences, Vol. 1, Issue 1 · 31 Mar 2008 · 8,477 accessesView PDFCite
Research ArticleOpen accessIn the abstractConvergence Ratio Profile for Optimal Control Problems Governed by Ordinary Differential Equations with Matrix CoefficientsO. Olotu, S.A. OlorunsolaThe geometric convergence ratio, the main focus of a discretized scheme for constrained quadratic control problem was examined. In order to allow for the numerical applications of the developed scheme, discretizing the time interval and using Euler’s scheme for its differential constraint obtained a finite dimensional approximation. Applying the penalty function method, an unconstrained problem was obtained on function minimization … …American Journal of Applied Sciences, Vol. 5, Issue 2 · 28 Feb 2008 · 7,108 accessesView PDFCite
Research ArticleOpen accessIn the abstractMINLP Optimization of Mechanical StructuresS. Šilih, T. Žula, Z. Kravanja, S. KravanjaWe presented optimization of mechanical structures, performed by the Mixed-Integer Nonlinear Programming (MINLP) optimization approach. The MINLP is a combined continuous/discrete optimization technique, where a structural topology and standard/discrete sizes are optimized simultaneously with the continuous variables. Ddiscrete binary 0-1 variables were used to express the discrete decisions. For solution of this non-linear, continuous/discrete and non-convex MINLP class of the … …American Journal of Applied Sciences, Vol. 5, Issue 1 · 31 Jan 2008 · 7,125 accessesView PDFCite
Research ArticleOpen accessIn the abstractOn the Discretized Algorithm for Optimal Problems Constrained by Differential Equation with Real CoefficientsO. OlotuA discretized scheme, Discretized Continuous Algorithm (DCA), for solving constrained quadratic optimal control problems was developed to ease the computational cumbersomeness inherent in some existing algorithms, particularly, the Function Space A lgorithm (FSA) by replacing the integral by a series of summation. In order to accomplish this numerical scheme, we resort to a finite approximation of it by discretizing its … …Journal of Mathematics and Statistics, Vol. 3, Issue 4 · 31 Dec 2007 · 6,851 accessesView PDFCite