فهرست مقالات Elyas Shivanian


  • مقاله

    1 - Numerical ‎S‎olution of Two-Dimensional Hyperbolic Equations with Nonlocal Integral Conditions Using Radial Basis Functions‎
    International Journal of Industrial Mathematics , شماره 1 , سال 11 , زمستان 2019
    This paper proposes a numerical method to the two-dimensional hyperbolic equations with nonlocal integral conditions. The nonlocal integral equation is of major challenge in the frame work of the numerical solutions of PDEs. The method benefits from collocation radial b چکیده کامل
    This paper proposes a numerical method to the two-dimensional hyperbolic equations with nonlocal integral conditions. The nonlocal integral equation is of major challenge in the frame work of the numerical solutions of PDEs. The method benefits from collocation radial basis function method, the generalized thin plate splines radial basis functions are used.Therefore, it does not require any struggle to determine shape parameter (In other RBFs, it is time-consuming step). پرونده مقاله

  • مقاله

    2 - Numerical Simulation of 1D Linear Telegraph Equation With Variable Coefficients Using Meshless Local Radial Point Interpolation (‎MLRPI)
    International Journal of Industrial Mathematics , شماره 2 , سال 10 , بهار 2018
    In the current work, we implement the meshless local radial point interpolation (MLRPI) method to find numerical solution of one-dimensional linear telegraph equations with variable coefficients. The MLRPI method, as a meshless technique, does not require any background چکیده کامل
    In the current work, we implement the meshless local radial point interpolation (MLRPI) method to find numerical solution of one-dimensional linear telegraph equations with variable coefficients. The MLRPI method, as a meshless technique, does not require any background integration cells and all integrations are carried out locally over small quadrature domains of regular shapes, such as lines in one dimensions, circles or squares in two dimensions and spheres or cubes in three dimensions. Weak form formulation of the discretized equations has been constructed on local subdomains, hence the domain and boundary integrals in the weak form methods can easily be evaluated over the regularly shaped subdomains by some numerical quadratures. Radial basis functions augmented with monomials are used in to create shape functions. These shape functions have delta function property. Also the time derivatives is eliminated by using two-step finite differences approximation. Two illustrative numerical examples are given to show the stability and accuracy of the present method. پرونده مقاله

  • مقاله

    3 - Existence of ‎W‎eak Solutions to a Kind of System of Fractional Semi-Linear Fredholm-Volterra Boundary Value Problem
    International Journal of Industrial Mathematics , شماره 2 , سال 14 , بهار 2022
    ‎This article is devoted to study the weak solutions of a class of nonlinear system of fractional boundary value problems including both Volterra and Fredholm linear integral terms. This system of fractional semi-linear Fredholm-Volterra integro-differential equatio چکیده کامل
    ‎This article is devoted to study the weak solutions of a class of nonlinear system of fractional boundary value problems including both Volterra and Fredholm linear integral terms. This system of fractional semi-linear Fredholm-Volterra integro-differential equations does have a gradient of a nonlinear source term as well. We apply the critical point theory and the variational structure to prove the existence of at least three distinct weak solutions to the system. Furthermore, it is presented an example to verify the legitimacy and applicability of the ‎theory.‎ پرونده مقاله

  • مقاله

    4 - Exact Closed-Form Result for the Heat Transfer From Convecting-Radiating Fin of Rectangular Shape
    International Journal of Industrial Mathematics , شماره 5 , سال 13 , پاییز 2021
    In this letter, the problem of determining heat transfer from convecting-radiating fin of rectangular shape is investigated. We consider steady conduction in the fin and neglect radiative exchange between adjacent fins and between the fin and its primary surface. It is چکیده کامل
    In this letter, the problem of determining heat transfer from convecting-radiating fin of rectangular shape is investigated. We consider steady conduction in the fin and neglect radiative exchange between adjacent fins and between the fin and its primary surface. It is demonstrated that the governing fin equation is exactly solvable. The exact, closed-form analytical solutions in implicit form are convenient for physical interpretation and optimization for maximum heat transfer. پرونده مقاله

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    5 - Existence and Uniqueness Analysis for a Class of Singular Non-Linear Two-Point Boundary Value Problems by an Optimal Iterative ‎Sequence
    International Journal of Industrial Mathematics , شماره 1 , سال 15 , زمستان 2023
    The convergence of thisiterative sequence is then controlled by an embedded parameter. The fastest convergence occurs for an optimal embedded parameter which maximizes a special function. This optimization problem brings a sequence with high rate of the convergence to t چکیده کامل
    The convergence of thisiterative sequence is then controlled by an embedded parameter. The fastest convergence occurs for an optimal embedded parameter which maximizes a special function. This optimization problem brings a sequence with high rate of the convergence to theunique solution in the finite region where $\frac{\partial f}{\partial y}$ has to be positive.Some illustrative examples are given to confirm the validity and reliability of this constructive theory. پرونده مقاله

  • مقاله

    6 - A Novel Shifted Jacobi Operational Matrix for Solution of Nonlinear Fractional Variable-Order Differential Equation with Proportional ‎Delays‎
    International Journal of Industrial Mathematics , شماره 4 , سال 14 , پاییز 2022
    This work presents the generalized nonlinear multi-terms fractional variable-order differential equation with proportional delays. In this paper, a novel shifted Jacobi operational matrix technique is introduced to solve a class of these equations mentioned, so that the چکیده کامل
    This work presents the generalized nonlinear multi-terms fractional variable-order differential equation with proportional delays. In this paper, a novel shifted Jacobi operational matrix technique is introduced to solve a class of these equations mentioned, so that the main problem becomes a system of algebraic equations that we can solve numerically. The suggested technique is successfully developed for the aforementioned problem. Comprehensive numerical tests are provided to demonstrate the generality, efficiency, accuracy of presented scheme and the flexibility of this technique. The numerical experiments compared it with other existing methods such as Reproducing Kernel Hilbert Space method ($ RKHSM $). Comparing the results of these methods as well as comparing the current method ($NSJOM$) with the true solution, indicating the validity and efficiency of this scheme. Note that the procedure is easy to implement and this technique will be considered as a generalization of many numerical schemes. Furthermore, the error and its bound are estimated. پرونده مقاله

  • مقاله

    7 - Generalization of Dodgson's "Virtual Center" Method; an Efficient Method for Determinant Calculation
    نظریه تقریب و کاربرد های آن , شماره 1 , سال 12 , بهار 2018
    Charles Dodgson (1866) introduced a method to calculate matrices determinant, in asimple way. The method was highly attractive, however, if the sub-matrix or the mainmatrix determination is divided by zero, it would not provide the correct answer. Thispaper explains the چکیده کامل
    Charles Dodgson (1866) introduced a method to calculate matrices determinant, in asimple way. The method was highly attractive, however, if the sub-matrix or the mainmatrix determination is divided by zero, it would not provide the correct answer. Thispaper explains the Dodgson method's structure and provides a solution for the problemof "dividing by zero" called "virtual center". پرونده مقاله

  • مقاله

    8 - A Second-Order Accurate Numerical Approximation for Two-Sided Fractional Boundary Value Advection-Diffusion Problem
    نظریه تقریب و کاربرد های آن , شماره 1 , سال 13 , زمستان 2019
    Fractional order partial differential equations are generalization of classical partialdifferential equations. Increasingly, these models are used in applications such as fluid flow, financeand others. In this paper we examine some practical numerical methods to solve a چکیده کامل
    Fractional order partial differential equations are generalization of classical partialdifferential equations. Increasingly, these models are used in applications such as fluid flow, financeand others. In this paper we examine some practical numerical methods to solve a class of initial-boundary value fractional partial differential equations with variable coefficients on a finite domain. An approach based on the classical Crank-Nicolson method combined with spatial extrapolation is used to obtain temporally and spatially second-order accurate numerical estimates. Stability, consistency, and convergence of the method are examined. It is shown that the fractional Crank-Nicolson method based on the shifted Gr"{u}nwaldformula is unconditionally stable. Some numerical examples are presented and compared with the exact analytical solutionfor its order of convergence.Fractional order partial differential equations are generalization of classical partialdifferential equations. Increasingly, these models are used in applications such as fluid flow, financeand others. In this paper we examine some practical numerical methods to solve a class of initial-boundary value fractional partial differential equations with variable coefficients on a finite domain. An approach based on the classical Crank-Nicolson method combined with spatial extrapolation is used to obtain temporally and spatially second-order accurate numerical estimates. Stability, consistency, and convergence of the method are examined. It is shown that the fractional Crank-Nicolson method based on the shifted Gr"{u}nwaldformula is unconditionally stable. Some numerical examples are presented and compared with the exact analytical solutionfor its order of convergence. پرونده مقاله

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    9 - The new Implicit Fi nite Difference Method for the Solution of Time Fractional Advection-Dispersion Equation
    نظریه تقریب و کاربرد های آن , شماره 1 , سال 12 , زمستان 2018
    In this paper, a numerical solution of time fractional advection-dispersion equations are presented.The new implicit nite difference methods for solving these equations are studied. We examinepractical numerical methods to solve a class of initial-boundary value fracti چکیده کامل
    In this paper, a numerical solution of time fractional advection-dispersion equations are presented.The new implicit nite difference methods for solving these equations are studied. We examinepractical numerical methods to solve a class of initial-boundary value fractional partial differentialequations with variable coefficients on a nite domain. Stability, consistency, and (therefore) convergenceof the method are examined and the local truncation error is O(Δt + h). This study concernsboth theoretical and numerical aspects, where we deal with the construction and convergence analysisof the discretization schemes. The results are justi ed by some numerical implementations. Anumerical example with known exact solution is also presented, and the behavior of the error isexamined to verify the order of convergence. پرونده مقاله

  • مقاله

    10 - Buckling of doubly clamped nano-actuators in general form through spectral meshless radial point interpolation (SMRPI)
    Journal of Nanoanalysis , شماره 500 , سال 1 , زمستان 2050
    The present paper is devoted to the development of a kind of spectral meshlessradial point interpolation (SMRPI) technique in order to obtain a reliable approx-imate solution for buckling of nano-actuators subject to different nonlinear forces.To end this aim, a general چکیده کامل
    The present paper is devoted to the development of a kind of spectral meshlessradial point interpolation (SMRPI) technique in order to obtain a reliable approx-imate solution for buckling of nano-actuators subject to different nonlinear forces.To end this aim, a general type of the governing equation for nano-actuators, con-taining integro-differential terms and nonlinear forces are considered. This generaltype for the nano-actuators is a non-linear fourth-order Fredholm integro-differentialboundary value problem. The point interpolation method with the help of radialbasis functions is used to construct shape functions which play as basis functions inthe frame of SMRPI. In the current work, the thin plate splines (TPS) are used asthe basis functions. This numerical based technique enables us to overcome all kindof nonlinearities in equation and then to obtain fast convergent solutions. Thus, itcan facilitate the design of nano-actuators. پرونده مقاله

  • مقاله

    11 - Buckling of Doubly Clamped Nano-Actuators in General form Through Spectral Meshless Radial Point Interpolation (SMRPI)
    Journal of Nanoanalysis , شماره 1 , سال 4 , زمستان 2017
    The present paper is devoted to the development of a kind of spectral meshless radial point interpolation (SMRPI) technique in order to obtain a reliable approximate solution for buckling of nano-actuators subject to different nonlinear forces. To end this aim, a genera چکیده کامل
    The present paper is devoted to the development of a kind of spectral meshless radial point interpolation (SMRPI) technique in order to obtain a reliable approximate solution for buckling of nano-actuators subject to different nonlinear forces. To end this aim, a general type of the governing equation for nano-actuators, containing integro-differential terms and nonlinear forces is considered. This general type for the nano-actuators is a non-linear fourth-order Fredholm integro-differential boundary value problem. The point interpolation method with the help of radial basis functions is used to construct shape functions which play as basis functions in the frame of SMRPI. In the current work, the thin plate splines (TPSs) are used as radial basis functions. This numerical based technique enables us to overcome all kind of nonlinearities in the mentioned boundary value problem and then to obtain fast convergent solution. Thus, it can facilitate the design of nano-actuators. پرونده مقاله