Now showing items 1-10 of 22
Cosmological models and the deceleration parameter.
In this thesis we utilise a form for the Hubble constant first proposed by Berman (1983) to study a variety of cosmological models. In particular we investigate the Robertson-Walker spacetimes, the Bianchi I spacetime, ...
Distances in and between graphs.
Aspects of the fundamental concept of distance are investigated in this dissertation. Two major topics are discussed; the first considers metrics which give a measure of the extent to which two given graphs are removed from ...
Spherically symmetric cosmological solutions.
This thesis examines the role of shear in inhomogeneous spherically symmetric spacetimes in the field of general relativity. The Einstein field equations are derived for a perfect fluid source in comoving coordinates. ...
Queueing and communication networks governed by generalised Lindley-Loynes equations.
Several decades after A.K. Erlang originated the theory of queues and queueing networks, D.V. Lindley added impetus to the development of this field by determining a recursive relation for waiting times. Part I of this ...
On the status of the geodesic law in general relativity.
The geodesic law for test particles is one of the fundamental principles of general relativity and is extensively used. It is thought to be a consequence of the field laws but no rigorous proof exists. This thesis is ...
Modelling the spatial dynamics of a semi-arid grazing system.
A large proportion of the world's land surface is covered by semi-arid grasslands, and they provide an important source of income as a grazing resource. A more comprehensive understanding of these complex ecosystems is ...
An algebraic study of residuated ordered monoids and logics without exchange and contraction.
Please refer to the thesis for the abstract.
A modelling approach for determining the freshwater requirements of estuarine macrophytes.
Increased abstraction of water in the catchment results in a reduced or altered pattern of river flow and this holds serious consequences for the downstream estuarine ecosystem. In South Africa this is a serious concern ...
The application of the multigrid algorithm to the solution of stiff ordinary differential equations resulting from partial differential equations.
We wish to apply the newly developed multigrid method  to the solution of ODEs resulting from the semi-discretization of time dependent PDEs by the method of lines. In particular, we consider the general form of two ...
Amplitude-shape method for the numerical solution of ordinary differential equations.
In this work, we present an amplitude-shape method for solving evolution problems described by partial differential equations. The method is capable of recognizing the special structure of many evolution problems. ...