We show that under certain conditions there is a one-to-one correspondence between weighted bounded solutions of a linear nonautonomous Volterra difference system with infinite delay and its perturbed system. Under additional ...

We investigate the evolution of the ridge produced by the non-symmetrical convergent motion of two substrates over which an initially uniform layer of a Newtonian liquid rests. The lack of symmetry of the flow arises because ...

We establish conditions to guarantee boundedness and convergence of signals described by non integer order equations using Caputo derivatives. The case of linear time-varying unforced equations is first studied, and ...

We discuss Rayleigh-Ritz variational calculations with nonorthogonal basis sets that exhibit the correct asymptotic behaviour. We construct the suitable basis sets for general one-dimensional models and illustrate the ...