A nodally exact scheme is derived for a model equation in 1D involving zeroth and second order terms. The method is derived using residual-free bubbles in conjunction with the Galerkin approximation. It is shown that this approach leads to the mass lumping scheme for su ciently small mesh sizes. 1. The residual-free bubbles approach. The usage of the Galerkin method enriched with bubble functio...

Systematic lumping of complex tropospheric chemical mechanisms using a time-scale based approach L. E. Whitehouse, A. S. Tomlin, and M. J. Pilling Energy and Resources Research Institute, University of Leeds, Leeds LS2 9JT, United Kingodm School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom Received: 1 April 2004 – Accepted: 6 May 2004 – Published: 8 July 2004 Correspondence ...

The Scaling Law for the Discrete Kinetic Growth Percolation Model The critical exponent of the total number of finite clusters α is calculated directly without using scaling hypothesis both below and above the percolation threshold pc based on a kinetic growth percolation model in two and three dimensions. Simultaneously, we can calculate other critical exponents β and γ, and show that the scal...

A discrete event system (DES) is a dynamic system that evolves in accordance with the abrupt occurrence, at possibly unknown irregular intervals, of physical events. Because of the special nature of these systems, different tools are currently used for their analysis, design and modeling. The main focus of this paper is the presentation of a new modeling approach of Discrete Event Systems. The ...

Various structural discontinuities, which form a discrete fracture network, play a significant role in the failure conditions and stability of the rock masses around underground excavations. Several continuum numerical methods have been used to study the stability of underground excavations in jointed rock masses but only few of them can take into account the influence of the pre-existing natur...