The main goal of this research is to analyse the effect of angular velocity on stability and vibration of a simply supported Rayleigh rotating shaft. To this end, non-dimensional kinetic and potential energies are written while lateral vibration is considered. Finite element method is employed to discrete the formulations and Linear method is applied to analyse instability threshold of a rotati...

In this paper we study the backward stability of running a stable eigenstructure solver on pencil $$S(\lambda )$$ that is strong linearization rational matrix $$R(\lambda expressed in form )=D(\lambda )+ C(\lambda I_\ell -A)^{-1}B$$ , where $$D(\lambda polynomial and $$C(\lambda minimal state-space realization. We consider family block Kronecker linearizations which have following structure $$\...

A fully discrete penalty finite element method is presented for the two-dimensional time-dependent Navier-Stokes equations. The time discretization of the penalty Navier-Stokes equations is based on the backward Euler scheme; the spatial discretization of the time discretized penalty Navier-Stokes equations is based on a finite element space pair (Xh,Mh) which satisfies some approximate assumpt...

This letter presents a novel cascade ΣΔ modulator architecture that employs inter-stage resonation to increase its effective resolution compared to traditional cascades while presenting very relaxed output swing requirements and, subsequently, high robustness to non-linearities of the amplifiers. In addition, the use of loop filters based on Forward-Euler integrators, instead of Backward-Euler ...

In this paper, a nonconforming mixed finite element method (FEM) is presented to approximate time-dependent Maxwell’s equations in a three-dimensional bounded domain with absorbing boundary conditions (ABC). By employing traditional variational formula, instead of adding penalty terms, we show that the discrete scheme is robust. Meanwhile, with the help of the element’s typical properties and d...

background: the children’s body composition status is an important indicator of health condition evaluated through their body mass index (bmi). we aimed to provide standardized percentile curves of bmi in a population of iranian children and adolescents. we assessed the nationally representative of sample populations from tehran. materials and methods: a total sample of 14,865 children aged 7-1...

Two midpoint-trapezoid pairs of dynamically equivalent (conjugate) algorithms are derived as compositions of first-order forward Euler and backward Euler integrators as applied to an incremental form of the initial-value problem of three-dimensional rigid body rotation. The algorithms are related to the recently developed methodology of the so-called Munthe-Kaas Runge–Kutta methods. Selected ex...

In this paper, we investigate an a posteriori error estimate of a control constrained optimal control problem governed by a time-dependent convection diffusion equation. Control constraints are handled by using the primal-dual active set algorithm as a semi-smooth Newton method or by adding a Moreau-Yosida-type penalty function to the cost functional. An adaptive mesh refinement indicated by a ...

We formulate a penalty method for the obstacle problem associated with a nonlinear variational principle. It is proven that the solution to the relaxed variational problem (in both the continuous and discrete settings) is exact for finite parameter values above some calculable quantity. To solve the relaxed variational problem, an accelerated forward-backward method is used, which ensures conve...