In this paper, we develop and analyze a preconditioning technique and an iterative solver for the linear systems resulting from the discretization of second order elliptic problems by the symmetric interior penalty discontinuous Galerkin methods. The main ingredient of our approach is a stable decomposition of the piecewise polynomial discontinuous finite element space of arbitrary order into a...

Piecewise linear networks (PLNs) are attractive because they can be trained quickly and provide good performance in many nonlinear approximation problems. Most existing design algorithms for piecewise linear networks are not convergent, non-optimal, or are not designed to handle noisy data. In this paper, four algorithms are presented which attack this problem. They are: (1) a convergent design...

We consider the topology of piecewise linear vector fields whose domain is a piecewise linear 2-manifold, i.e. a triangular mesh. Such vector fields can describe simulated 2-dimensional flows, or they may reflect geometric properties of the underlying mesh. We introduce a thinning technique which preserves the complete topology of the vector field, i.e. the critical points and separatrices. As ...

For linear hybrid systems consisting of linear dynamic equations interacting with linear threshold events, automata, and logic propositions, provided in mixedlogical dynamical (MLD) form, this paper describes an efficient technique for transforming such systems into an equivalent piecewise affine (PWA) form, where equivalent means that for the same initial conditions and input sequences the tra...