28 articles for “Difference Equations”

Research ArticleOpen accessIn the abstractREFLECTION OF A WEAK DISCONTINUITY OF THE AXIS AND THE PLANE OF SYMMETRYBulat Pavel ViktorovichIn this article we consider the problem of discontinuous characteristic (weak discontinuity) reflection from the axis and the plane of symmetry of the supersonic flow. There is a known problem of perturbations radial focusing when during numerical calculations reflection of a weak perturbation wave from the axis of symmetry leads to an abrupt change in the distribution of dynamics variables … …American Journal of Applied Sciences, Vol. 11, Issue 6 · 17 Apr 2014 · 6,529 accessesView PDF Cite

Research ArticleOpen accessIn the abstractEstimation of Genetic Correlations on Sweet Corn Inbred Lines Using SAS Mixed ModelPedram Kashiani, Ghizan SalehProblem statement: Genetic correlations among traits refer to the extent of relatedness among them due to genetic causes. Estimating genetic correlations for quantitative traits is tedious if done manually. Approach: However, the use of the computer software SAS, applying mixed-model analysis of variance has facilitated many recent studies in evolutionary quantitative genetics. Results: In this two-way statistical model, the variance … …American Journal of Agricultural and Biological Sciences, Vol. 5, Issue 3 · 30 Sep 2010 · 10,891 accessesView PDF Cite

Research ArticleOpen accessIn the abstractHigher-Order Newton-Cotes FormulasPedro Americo Almeida Magalhaes Junior, Cristina Almeida MagalhaesProblem statement: The present work offers equations of Newton-Cotes Integration until twenty segments. Approach: It shows Newton-Cotes closed and open integration formulas. The new type Newton-Cotes semi-closed or semi-open was proposed. Results: An analysis of error in the technique was made. To estimate the error of integration in discrete data, we propose apply different rules or mix several rules. Conclusion/Recommendations: … …Journal of Mathematics and Statistics, Vol. 6, Issue 2 · 30 Jun 2010 · 9,750 accessesView PDF Cite

Research ArticleOpen accessIn the abstractDesign and Optimization of a 1.55 µm Waveguide Based on Silicon Planar Photonic CrystalsR. Bchir, A. Bardaoui, M. Machhout et al.Background: Silicon based Planar Photonic Crystals (PPC) are used for the design of a 1.55 µm waveguide. Line defects are then formed in the PPC structures, by removing rows of holes, to obtain a Planar Photonic Crystal Waveguide (PPCW). Objective: First, we varied the thickness of the Silicon slab and the pore radius in order to obtain optimum design parameters … …American Journal of Applied Sciences, Vol. 7, Issue 1 · 31 Jan 2010 · 7,472 accessesView PDF Cite

Research ArticleOpen accessIn the abstractMathematical Model of Double Pass Photovoltaic Thermal Air Collector with FinsEbrahim M. Ali Alfegi, Kamaruzzaman Sopian, Mohd Yusof Hj Othman, Baharudin Bin YatimProblem statement: The efficiency of photovoltaic cells is generally temperature dependent (efficiency decrease when the temperature of the photovoltaic cells increase). This problem can be solved by cooling the solar cells during operation and operated at low temperature. Approach: This study presented a numerical model of double pass Photovoltaic Thermal (PV/T) solar air collector with fins attached to the back … …American Journal of Environmental Sciences, Vol. 5, Issue 5 · 31 Oct 2009 · 8,006 accessesView PDF Cite

Research ArticleOpen accessIn the abstractThree Dimensional Flow Analyses in a Diagonal Type MHD GeneratorTriwahju Hardianto, Nobuomi Sakamoto, Nob. HaradaThis paper studied development of the three dimensional flow fields in a diagonal channel MHD generator. A diagonal insulating sidewalls type channel is proposed in this work. The partial-differential equations for the three momentum, the enthalpy and the electrical fields are solved by a finite-difference calculation procedure. The turbulence phenomenon is represented by two-equation turbulence model. Calculations have been made … …American Journal of Applied Sciences, Vol. 3, Issue 8 · 31 Aug 2006 · 6,917 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordAccelerators in Macroeconomics: Comparison of Discrete and Continuous ApproachesVasily E. Tarasov, Valentina V. TarasovaWe prove that the standard discrete-time accelerator equation cannot be considered as an exact discrete analog of the continuous-time accelerator equation. This leads to fact that the standard discrete-time macroeconomic models cannot be considered as exact discretization of the corresponding continuous-time models. As a result, the equations of the continuous and standard discrete models have different solutions and can predict … …American Journal of Economics and Business Administration, Vol. 9, Issue 3 · 10 Nov 2017 · 8,633 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordMagneto Convection in Tilted Square Cavity with Differentially Thermally Active Vertical WallsGokila Subbarayalu, Selladurai VelappanProblem statement: The purpose of this study is to study numerically the magnetoconvection in a tilted square cavity with differentially thermally active vertical walls. The two vertical side walls of tilted enclosure are differentially thermally active, each consisting of alternating equal sized hot and cold surface elements facing each other in an opposed manner while the horizontal top and bottom … …Journal of Mathematics and Statistics, Vol. 7, Issue 2 · 25 May 2011 · 7,355 accessesView PDF Cite