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In this article, we develop an iterative scheme based on the meshless methods to simulate the solution of one dimensional stochastic evolution equations using radial basis function (RBF) interpolation under the concept of Gaussian random field simulation. We use regularized Kansa collocation to approximate the mean solution at space and the time component is discretized by the global $ theta $-weighted method. Karhunen-lo`{e}ve expansion is employed for simulating the Gaussian random field. Statistical tools for numerical analysis are standard deviation, absolute error, and root mean square. In this work, we solve two major problems for showing the convergence, and stability of the presented method on two problems. The first problem is the
In this paper, we introduce numerical schemes and their analysis based on weak Galerkin finite element framework for solving 2‐D reaction–diffusion systems. Weak Galerkin finite element method (WGFEM) for partial differential equations relies on the concept of weak functions and weak gradients, in which differential operators are approximated by weak forms through the Green's theorem. This method allows the use of totally discontinuous functions in the approximation space. In the current work, the WGFEM solves reaction–diffusion systems to find unknown concentrations (u, v) in element interiors and boundaries in the weak Galerkin finite element space WG(P0, P0, RT0). The WGFEM is used to approximate the spatial variables and the
A new weak Galerkin finite element method is applied for time dependent Brusselator reaction-diffusion systems by using discrete weak gradient operators over discontinuous weak functions. In this work, we consider the lowest order weak Galerkin finite element space . Discrete weak gradients are defined in Raviart-Thomas space. Thus we employ this approximate space on triangular mesh for solving unknown concentrations in Brusselator reaction-diffusion systems. Based on a weak varitional form, semi-discrete and fully-discrete weak Galerkin finite element scheme are obtained. In addition, the paper presents some numerical results to illustrate the power of proposed method.
The aim of this paper is to study the numerical application of radial basis functions (RBFs) approximation in the reconstruction process of well known ENO/WENO schemes. The resulted schemes are employed for approximating the viscosity solution of Hamilton–Jacobi (H–J) equations. The accuracy in the smooth area is enhanced by locally optimizing the shape parameter according to the results. It is revealed that the proposed schemes in this research prepare more accurate reconstructions and sharper solution near singularities by comparing the RBFENO/RBFWENO schemes and the classical ENO/WENO schemes for some benchmark examples. Looking at the several numerical examples in 1D, 2D and 3D illustrate that the proposed schemes in this paper perf
A new weak Galerkin finite element method is applied for time dependent Brusselator reaction-diffusion systems by using discrete weak gradient operators over discontinuous weak functions. In this work, we consider the lowest order weak Galerkin finite element space . Discrete weak gradients are defined in Raviart-Thomas space. Thus we employ this approximate space on triangular mesh for solving unknown concentrations in Brusselator reaction-diffusion systems. Based on a weak varitional form, semi-discrete and fully-discrete weak Galerkin finite element scheme are obtained. In addition, the paper presents some numerical results to illustrate the power of proposed method.
Honey bee is the insect that mainly pollens agricultural products. In recent decades, colony failure rates as a global concern have increased. Some mathematical models have been proposed. In one of the first models the impact of bee death rates on population dynamics was studied and then the food availability and the rate of broods added to the model. Here we improve the model by considering seasonal changes and death rate of hive bees. Our results show that death rates higher than 0. 41 lead to colony collapse. At higher death rates, despite of colony failure, food stored in colony and this is instance of colony collapse. Additionally, the model predicts the minimum food needed for colony in various death rates.
Aging is a dynamic concept in today’s world, and the quality of life should be taken into consideration as the elderly population grows. Therefore, the purpose of this study is to investigate the simple and multiple relationship between psychological, spiritual and social capital with clinical symptoms of elderly people living in nursing homes of Chaharmahal and Bakhtaran province. To this end, 200 elderly people were selected by simple random sampling method and responded to the questionnaires. The research tools include the Luthans’ Psychological Capital Questionnaire (PCQ), Kings’ Spiritual Capital, Onyx’s Social Capital, and Clinical Symptoms. The results show that there is a reverse and significant correlation (at a level less
In this paper, a meshless collocation method is considered to solve the multi-term time fractional diffusion-wave equation in two dimensions. The moving least squares reproducing kernel particle approximation is employed to construct the shape functions for spatial approximation. Also, the Caputo’s time fractional derivatives are approximated by a scheme of order O (τ 3− α), 1< α< 2. Stability and convergence of the proposed scheme are discussed. Some numerical examples are given to confirm the efficiency and reliability of the proposed method.
This study was aimed to investigate psychometric properties of identity style scale among high school students. For this purpose 365 subjects were selected by simple random sampling and responded to identity style scale. The results of the validation and factor analysis showed normality in it. Through the general formula alpha reliability coefficient scale is 0.78. Principal components analysis shows that the questioner has six main factors. These six factors including successful identity, confused identity, premature identity, professional identity, religious identity and collective identity that determined about 45.2% of the variance.
In this paper, the meshless local Petrov–Galerkin (MLPG) method is employed to solve the 2-D time-dependent Maxwell equations. The MLPG method is a truly meshless method in which the trial and test functions are chosen from totally different functional spaces. In the current work, the moving least square reproducing kernel (MLSRK) scheme is chosen to be the trial function. The method is applied for the unsteady Maxwell equations in different media. In the local weak form, by employing the difference operator for evolution in time and simultaneously in time and space, the semi-discrete and fully discrete schemes are obtained respectively. The error estimation is discussed for both the semi-discrete and fully-discrete numerical schemes for
Interest in meshless methods has grown rapidly in recent years in solving boundary value problems (BVPs) arising in science and engineering. In this paper, we present the moving least square radial reproducing polynomial (MLSRRP) meshless method as a generalization of the moving least square reproducing kernel particle method (MLSRKPM). The proposed method is established upon the extension of the MLSRKPM basis by using the radial basis functions. Some important properties of the shape functions are discussed. An interpolation error estimate is given to assess the convergence rate of the approximation. Also, for some class of time-dependent partial differential equations, the error estimate is acquired. The efficiency of the present method i
In this paper a meshfree weak-strong (MWS) form method is considered to solve the coupled equations in velocity and magnetic field for the unsteady magnetohydrodynamic flow throFor this modified estimaFor this modified estimaFor this modified estimaugh a pipe of rectangular and circular sections having arbitrary conducting walls. Computations have been performed for various Hartman numbers and wall conductivity at different time levels. The MWS method is based on applying a meshfree collocation method in strong form for interior nodes and nodes on the essential boundaries and a meshless local Petrov–Galerkin method in weak form for nodes on the natural boundary of the domain. In this paper, we employ the moving least square
A generalization of moving least square reproducing kernel method is presented in this work. The moving least square reproducing kernel method is obtained by using a moving least square scheme but not in the discrete version. The resulted scheme provides a continuous basis which is able to reproduce any - order polynomial, and prepares a scheme that can approximate smooth functions with an optimal accuracy. On the other hand, considering the power of moving least square scheme in meshless approximation for the numerical solution of partial differential equations, the generalized moving least square approximation is able to approximate just in terms of node values where is an arbitrary linear operator. In this paper, a generalization of mo