We present a finite element method for time-dependent convectiondiffusion equations. The method is explicit and is applicable with piecewise polynomials of degree n > 2 . In the limit of zero diffusion, it reduces to a recently analyzed finite element method for hyperbolic equations. Near optimal error estimates are derived. Numerical results are given.

A piecewise algebraic curve is a curve defined by the zero set of a bivariate spline function. Given two bivariate spline spaces Sm Δ and S t n Δ over a domain D with a partition Δ, the Bezout number BN m,r;n,t;Δ is defined as the maximum finite number of the common intersection points of two arbitrary piecewise algebraic curves f x, y 0 and g x, y 0, where f x, y ∈ Sm Δ and g x, y ∈ Sn Δ . In ...

In this paper we study the existence problem of a zero point of a function defined on a finite set of elements of the integer lattice Z of the n-dimensional Euclidean space IR. It is assumed that the set is integrally convex, which implies that the convex hull of the set can be subdivided in simplices such that every vertex is an element of Z and each simplex of the triangulation lies in an n-d...

We investigate an implicit method to compute a piecewise linear representation of a surface from a set of sample points. As implicit surface functions we use the weighted sum of piecewise linear kernel functions. For such a function we can partition Rd in such a way that these functions are linear on the subsets of the partition. For each subset in the partition we can then compute the zero lev...

The zero level set of a piecewise-affine function with respect to a consistent tetrahedral subdivision of a domain in R3 is a piecewise-planar hyper-surface. We prove that if a family of consistent tetrahedral subdivions satisfies the minimum angle condition, then after a simple postprocessing this zero level set becomes a consistent surface triangulation which satisfies the maximum angle condi...

let $g=(v,e)$ be a simple graph. a set $ssubseteq v$ isindependent set of $g$,  if no two vertices of $s$ are adjacent.the  independence number $alpha(g)$ is the size of a maximumindependent set in the graph. in this paper we study and characterize the independent sets ofthe zero-divisor graph $gamma(r)$ and ideal-based zero-divisor graph $gamma_i(r)$of a commutative ring $r$.

This paper shows that Lyapunov-based state feedback controller synthesis for piecewise-affine (PWA) slab systems can be cast as an optimization problem subject to a set of linear matrix inequalities (LMIs) analytically parameterized by a vector. Furthermore, it is shown that continuity of the control inputs at the switchings can be guaranteed by adding equality constraints to the problem withou...

−Stabilization of uncertain hybrid systems with controllable transitions is considered. Uncertainty enters in the form of a disturbance input that can affect both the continuous and the discrete dynamics. A method for designing piecewise constant feedback controllers is developed. The controllers achieve approximate exponential convergence of the runs of the closed loop system to the zero level...

I announce a solution of the conjecture about the measure of periodic points for planar billiard tables. The theorem says that if Ω ⊂ R is a compact domain with piecewise C boundary, then the set of periodic orbits for the billiard in Ω has measure zero. Here I outline a proof. A complete version will appear elsewhere.