A new method combining a finite difference method and a reduced order model (ROM) algorithm is presented for twodimensional (2-D) electromagnetic problems. The problem space is subdivided into subdomains of a generic type. By discretizing the spatial derivatives in a way similar to the finite-difference in time-domain technique (FDTD), the state equations are written down in each subdomain. Fro...

The cervix is a biochemically active tissue that changes its biomechanical properties in a remodeling process during pregnancy to be prepared for parturition. This maturation process is associated with changes of the mechanical properties of the cervical stroma. Preterm delivery is connected with undesired cervical changes bound to cervical ripening. Non-destructive evaluation using ultrasonic ...

In this paper, we derive a discretized multi-group epidemic model with time delay by using a nonstandard finite difference (NSFD) scheme. A crucial observation regarding the advantage of the NSFD scheme is that the positivity and boundedness of solutions of the continuous model are preserved. Furthermore, we show that the discrete model has the same equilibria, and the conditions for their stab...

The space and time discretization inherent to all FDTD schemes introduce non-physical dispersion errors, i.e. deviations of the speed of sound from the theoretical value predicted by the governing Euler differential equations. A general methodology for computing this dispersion error via straightforward numerical simulations of the FDTD schemes is presented. The method is shown to provide remar...

The nonlinear solvers in numerical solution of water flow in variably saturated soils are prone to convergence difficulties. Many aspects can give rise to such difficulties, like very dry initial conditions, a steep pressure gradient and great variation of hydraulic conductivity occur across the wetting front during the infiltration of water.  So, the averaging method applied to compute hydraul...

Due to its own structural characteristics, such as multi porosity, low density and water sensitivity, loess disasters occur continuously, rainfall is the main factor causing slope damage. Loess failures induced by infiltration frequently, due special characteristics sensitivity. Taking a secondary railway in Xinzhou City reference, model built carry out test of slope. The influence intensity, a...

and Applied Analysis 3 andX E = x−uΔt (similarly we see thatX E = x−2uΔt for the two-step methods). In (7) with X being replaced by X E , we have φ n+1 − φ n (x − uΔt) Δt − νΔφ n+1 = f n+1 . (9) On the other hand, (9) can be derived by MMOC [5]. In fact, with u = (u 1 , u 2 ), let s denote the direction vector (1, u 1 , u 2 ), and define the operator d ds := 1 θ ( ∂ ∂t + u ⋅ ∇) , (10) with θ(x,...