Browsing Doctoral Degrees (Mathematics and Computer Science Education) by Issue Date
Now showing items 120 of 73

On purity relative to an hereditary torsion theory.
(1992)The thesis is mainly concerned with properties of the concept "σpurity" introduced by J. Lambek in "Torsion Theories, Additive Semantics and Rings of Quotients", (SpringerVerlag, 1971). In particular we are interested ... 
Conformally invariant relativistic solutions.
(1993)The study of exact solutions to the Einstein and EinsteinMaxwell field equations, by imposing a symmetry requirement on the manifold, has been the subject of much recent research. In this thesis we consider specifically ... 
Polynomial approximations to functions of operators.
(1994)To solve the linear equation Ax = f, where f is an element of Hilbert space H and A is a positive definite operator such that the spectrum (T (A) ( [m,M] , we approximate 1 the inverse operator A by an operator V which ... 
Aspects of distance and domination in graphs.
(1995)The first half of this thesis deals with an aspect of domination; more specifically, we investigate the vertex integrity of ndistancedomination in a graph, i.e., the extent to which ndistancedomination ... 
Spherically symmetric cosmological solutions.
(1996)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. ... 
Graph and digraph embedding problems.
(1996)This thesis is a study of the symmetry of graphs and digraphs by considering certain homogeneous embedding requirements. Chapter 1 is an introduction to the chapters that follow. In Chapter 2 we present a brief survey ... 
Amplitudeshape method for the numerical solution of ordinary differential equations.
(1997)In this work, we present an amplitudeshape method for solving evolution problems described by partial differential equations. The method is capable of recognizing the special structure of many evolution problems. ... 
A modelling approach for determining the freshwater requirements of estuarine macrophytes.
(1998)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 ... 
An algebraic study of residuated ordered monoids and logics without exchange and contraction.
(1998)Please refer to the thesis for the abstract. 
On the status of the geodesic law in general relativity.
(1998)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 ... 
FischerClifford theory for split and nonsplit group extensions.
(2001)The character table of a finite group provides considerable amount of information about the group, and hence is of great importance in Mathematics as well as in Physical Sciences. Most of the maximal subgroups of the finite ... 
A new approach to illposed evolution equations : Cregularized and B bounded semigroups.
(2001)The theory of semigroups of linear operators forms an integral part of Functional Analysis with substantial applications to many fields of the natural sciences. In this study we are concerned with the application to ... 
Aspects of functional variations of domination in graphs.
(2003)Let G = (V, E) be a graph. For any real valued function f : V >R and SCV, let f (s) = z ues f(u). The weight of f is defined as f(V). A signed ksubdominating function (signed kSF) of G is defined as a function f : V > ... 
Anisotropic stars in general relativity.
(2004)In this thesis we seek new solutions to the anisotropic Einstein field equations which are important in the study of highly dense stellar structures. We first adopt the approach used by Maharaj & Maartens (1989) to obtain ... 
Optimal designs for linear mixed models.
(2004)The research of this thesis deals with the derivation of optimum designs for linear mixed models. The problem of constructing optimal designs for linear mixed models is very broad. Thus the thesis is mainly focused on the ... 
The role and use of sketchpad as a modeling tool in secondary schools.
(2004)Over the last decade or two, there has been a discernible move to include modeling in the mathematics curricula in schools. This has come as the result of the demand that society is making on educational institutions to ... 
FischerClifford matrices of the generalized symmetric group and some associated groups.
(2005)With the classification of finite simple groups having been completed in 1981, recent work in group theory has involved the study of the structures of simple groups. The character tables of maximal subgroups of simple ... 
Stratification and domination in graphs.
(2006)In a recent manuscript (Stratification and domination in graphs. Discrete Math. 272 (2003), 171185) a new mathematical framework for studying domination is presented. It is shown that the domination number and many ... 
Exact models for radiating relativistic stars.
(2007)In this thesis, we seek exact solutions for the interior of a radiating relativistic star undergoing gravitational collapse. The spherically symmetric interior spacetime, when matched with the exterior radiating Vaidya ...