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The problem of constructing a matrix by its spectral information is called inverse eigenvalue problem (IEP) which arises in a variety of applications. In this paper, we study an IEP for arrowhead matrices in different cases. The problem involves constructing of the matrix by some eigenvalues of each of the leading principal submatrices and one eigenpair. We will also investigate this problem and its variants in the cases of matrix entries being real, nonnegative, positive definite, complex and equal diagonal entries. To solve the problems, a new method to establish a relationship between the IEP and properties of symmetric and general form of matrices is developed. The necessary and sufficient conditions of the solvability of the problems are obtained. Finally, some numerical examples are presented. [ABSTRACT FROM AUTHOR]

Because of the importance of the analytical study of the vibration behavior of nanotubes delivering nanoparticles, in this study, the transverse vibration of these systems has been studied by analytical approach based on the homotopy perturbation method. The nonlocal Euler–Bernoulli beam theory is used for derivation of the equation of motion. The interaction between nanoparticle and the inner wall of nanotube has been modeled by using van der Waals forces and considering the effects of inertial forces caused by centrifugal and Coriolis acceleration components of nanoparticles. After evaluation of the implemented analytical method by numerical results, it is revealed that the obtained second-order approximation response gives high accurate vibration behavior of these systems for a wide range of parameters. As well, these results show that inertial forces caused by motion of nanoparticle increase vibration amplitude of nanotube and change nonlinear frequency of the system. [ABSTRACT FROM AUTHOR]

One of the schemes to find the optimal shape parameter and optimal number of points in the radial basis function (RBF) methods is to apply the stochastic arithmetic (SA) in place of the common floating-point arithmetic (FPA). The main purpose of this work is to introduce a reliable approach based on this new arithmetic to compute the local optimal shape parameter and number of points in multiquadric and Gaussian RBF-meshless methods for solving differential equations, in the iterative process. To this end, the CESTAC method is applied. Also, in order to implement the proposed algorithms, the CADNA library is performed. The examples illustrate the efficiency and importance of using this library to validate the results. [ABSTRACT FROM AUTHOR]