We present a fast contour-integral eigensolver for finding selected or all the eigenpairs of a non-Hermitian matrix based on a series of analytical and computational techniques, such as the analysis of filter functions, quick and reliable eigenvalue count via low-accuracy matrix approximations, and fast shifted factorization update. The quality of some quadrature rules for approximating a relev...

In [5] and [2] the authors describe the remarkable effectiveness of the doubly exponential ‘tanh-sinh’ transformation for numerical integration —even for quite unruly integrands. Our intention in this note is to provide a theoretical underpinning when the integrand is analytic for the observed superlinear convergence of the method. Our analysis rests on the corresponding but somewhat easier ana...

High order approximations of an integral can be obtained by taking the linear combination of lower degree approximations in a systematic way. One of these approaches for 1-d integrals is known as Romberg Integration and is based upon the composite trapezoidal rule approximations and the well-known Euler-Maclaurin expansion of the error. Because of its theoretical nature, students in a classical...

Transient noise analysis means time domain simulation of noisy electronic circuits. We consider mathematical models where the noise is taken into account by means of sources of Gaussian white noise that are added to the deterministic network equations, leading to systems of stochastic differential algebraic equations (SDAEs). A crucial property of the arising SDAEs is the large number of small ...

Grey system is a theory which specially studies poor information, and it possesses wide suitability. The parameters of multivariable grey FMGM(1,n) model with the fractional order accumulation can reflect the restricted and affected multi-variables relation with one another. We start by constructing background values based on vector continued fractions theory by using rational interpolation wit...

A stabilized stochastic finite element implementation for the natural convection system of equations under Boussinesq assumptions with uncertainty in inputs is considered. The stabilized formulations are derived using the variational multiscale framework assuming a one-step trapezoidal time integration rule. The stabilization parameters are shown to be functions of the time-step size. Provision...

This paper explores the study of Multi-Objective Multi-item Solid Transportation Problem (MMSTP) under fuzzy environment. Realizing impact real-life situations, here we consider MMSTP with parameters, e.g. , transportation cost, supply, and demand, treat as trapezoidal numbers. Trapezoidal numbers are then converted into nearly approximation interval by using (P. Grzegorzewski, Fuzzy Sets Syst....

A numerical model is presented for computation of unsteady two-fluid interfaces in nonlinear porous media flow. The nonlinear Forchheimer equation is included in the Navier-Stokes equations for porous media flow. The model is based on capturing the interface on a fixed mesh domain. The zero level set of a pseudo-concentration function, which defines the interface between the two fluids, is gove...

In this paper, a novel algorithm for transient linear circuit analysis based on the Finite Element Technique (FET) was established. The FET procedure allows straightforward solution complex electric circuits since it is Method (FEM) approach. developed us to select various types of time integration schemes when forming local system equations coupled finite element. To illustrate basic principle...