Two approaches to the nonlinear functions approximation problem.

Nonlinear Two-Phase Stefan Problem

In this paper we consider a nonlinear two-phase Stefan problem in one-dimensional space. The problem is mapped into a nonlinear Volterra integral equation for the free boundary.

Two Approaches to the Initial Transient Problem

This paper describes two diierent approaches to dealing with the initial transient problem. In the rst approach, the length of the \warm-up period" is determined by obtaining analytical estimates on the rate of convergence to stationarity. Speciically, we obtain an upper bound on the \second eigenvalue" of the transition matrix of a Markov chain, thereby providing one with a theoretical device ...

Two neighbourhood approaches to the timetabling problem

It is well known that any search algorithm needs for certain parts to be problem specific. It is very important the way these parts are implemented. A fine tuning of parameters will never balance a bad definition of the solution set, of the neighbourhood or the cost function. In this paper we try to compare two well known neighbourhood operators applied to the timetabling problem. Tests were ma...

Nonlinear Approximation of Random Functions

Given an orthonormal basis and a certain class X of vectors in a Hilbert space H, consider the following nonlinear approximation process: approach a vector x ∈ X by keeping only its N largest coordinates, and let N go to infinity. In this paper, we study the accuracy of this process in the case where H = L(I), and we use either the trigonometric system or a wavelet basis to expand this space. T...

Huber Approximation for the Nonlinear l1 Problem