A new approach to simulating spherical shallow-water flows is described and illustrated. The approach exploits the distinction between slow vortical motions and fast gravity waves at leading order. Contour advection is used for the vortical part, specifically for the potential vorticity. This allows an accurate representation of the vortical dynamics at modest grid resolution. New variables are...

Exact solutions are derived for an n-dimensional radial wave equation with a general power nonlinearity. The method is based on the introduction of groupinvariant jet space variables associated with the point symmetry group admitted for the wave equation and is applicable more generally to any nonlinear PDEs. It is shown to yield not only group-invariant solutions as derived by standard symmetr...

We present a design optimization method for reducing the wave resistance (drag) of surface piercing hulls. Since this component of the drag is directly related to the energy contained in the wave structure that extends behind the ship, a fully coupled calculation of the flow field and wave evolution equation is required. The method combines the authors’ efficient automatic shape optimization te...

Background: We designed a cross-sectional study to determine electrocardiographic disorders in Down syndrome patients with congenitally normal hearts in a bid to predict fatal cardiac arrhythmia in the future. Materials and Methods: We investigated 60 children with DS without congenital abnormal hearts. Sixty healthy juveniles were also included in the study as a control group. Physical examina...

Stochastic description and simulation of oceanographic variables are essential for coastal and marine engineering applications. In the past decade, copula-based approaches have become increasingly popular to estimate the multivariate distribution of some variables at the peak of a storm along with its duration. The modeling of the storm shape, which contributes to its impact, is often simplifie...

|Based on the notion of wave variables, and the idea of wave-integral transmission, a new method is suggested to match the system parameters with changes in the delay. An autoregressive model is used as a predictor to forecast the future values of the delay. The predictions are used with a look-up table to tune the gain with which the wave integrals are to be fed to the system. This gain schedu...

We assess whether the probability of a sample member participating at a particular wave of a panel survey is greater if the same interviewer is deployed as at the previous wave. Previous research on this topic mainly uses non-experimental data. Consequently, a) interviewer change is generally non-random, and b) continuing interviewers are more experienced by the time of the next wave. We design...