The results of the Householder and QL algorithms for determining the eigenelements of a symmetric matrix, provided by a computer, always contain the errors resulting from floating-point arithmetic round-off error propagation. The Permutation-Perturbation method is a very efficient practical...

The purpose of this paper is to look at the problem of propagation of round-off errors in fixed-point arithmetic and at various problems of checking solutions of equations already treated by La Porte and Vignes in the case of floating-point arithmetic. We first consider the probabilistic model...

It is shown that one-dimensional C1-collocation at the Gauss points may be viewed as a member of a family of 3-point finite difference schemes. This new formulation of the method leads to a simple practical technique for the elimination of the derivative degrees of freedom. In contrast to what...

During forced-convection air-cooling of grain in warm climates, ambient heat warms grain in the region adjacent to the walls of the grain-store. Consequently, grain spoilage is possible in the uncooled wall-region and this work simulates conditions in that region. Transient results show the...

In this paper, a formal space for the modelization of computer arithmetic and a pseudo-distance defined on this space to study computer iterative sequences is proposed. Some properties if this pseudo-distance are examined and a termination criterion for iterative sequences in this space is...

An embodiment is a simulation program in which particular models are defined using a formal language that represents processes in the real world. The motivation for such programs comes from the increasing use of formal languages as modelling tools; examples are given of applications to growth,...

To retain the advantages of conceptual modelling while addressing the difficulty of parameter estimation, a procedure is proposed in which model structure is developed progressively, with model performance and associated parameter uncertainty being evaluated at each stage, to determine whether...

Models of heat and mass transfer in the pyrolysis of Julia Creek oil shale have been developed. Results for single particles are compared with those for clusters of particles and the effect of periodic temperature fluctuations, as would be experienced in mixing of solids in a retort, is discussed.

A method of documenting simulation models in a form designed to suit the needs of those having little knowledge of mathematics or computer jargon is described. Extracts are included of such documentation for two models, one relating to energy, the other forestry. In each case the description won...

Rationalized Haar functions (RHFs, for short) are applied for solving linear first- and second-order partial differential equations (PDEs, for short). For this purpose, new operational matrices of integration and differentiation based on a double rationalized Haar series are derived. By using...