Now showing items 35-54 of 67

    • Identifying and modeling the dynamics of a core cancer sub-network. 

      Bayleyegn, Yibeltal Negussie. (2011)
      Many recent studies have shown that the initiation of human cancer is due to the malfunction of some genes at the R-checkpoint during the G1-to-S transition of the cell cycle. Identifying and modeling the dynamics of ...
    • Impact of exogenous reinfection on TB infection in a genetically susceptible population. 

      Mwangi, Wangari Isaac. (2013-12-17)
      In this study we investigated the impact of exogenous reinfection on genetically resistant and genetically sensitive sub populations. We qualitatively analysed the dynamics of TB by assuming that TB is transmitted in two ...
    • Initial conditions of the universe : signatures in the cosmic microwave background and baryon acoustic oscillations. 

      Kasanda, Simon Muya. (2012)
      In this thesis, we investigate the signatures of isocurvature initial conditions in the cosmic microwave background (CMB) through the temperature and polarization anisotropies, and in the large-scale structure distribution ...
    • Interative approaches to convex feasibility problems. 

      Pillay, Paranjothi. (2001)
      Solutions to convex feasibility problems are generally found by iteratively constructing sequences that converge strongly or weakly to it. In this study, four types of iteration schemes are considered in an attempt to ...
    • Matrices of graphs and designs with emphasis on their integral eigen-pair balance characteristic. 

      Jessop, Carol Lynne. (2015-01-05)
      The interplay between graphs and designs is well researched. In this dissertation we connect designs and graphs entirely through their associated matrices – the incidence matrix for designs and the adjacency matrix for ...
    • Matrix models of population theory. 

      Abdalla, Suliman Jamiel Mohamed. (2014-05-12)
      Non-negative matrices arise naturally in population models. In this thesis, we first study Perron- Frobenius theory of non-negative irreducible matrices. We use this theory to investigate the asymptotic behaviour ...
    • A modelling approach for determining the freshwater requirements of estuarine macrophytes. 

      Wortmann, Joanne. (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 ...
    • Modelling the response of cytotoxic t-lymphocytes in controlling solid tumour invasion. 

      Malinzi, Joseph. (2013-12-20)
      We present mathematical models to study the mechanism of interaction of tumour infiltrating cytotoxic lymphocytes (TICLs) with tumour cells. We focus on the phase spaces of the systems and the nature of the solutions for ...
    • Modelling waterborne diseases. 

      Collins, Obiora C. (2015-03-20)
      Waterborne diseases are among the major health problems threatening the life of individuals globally. This thesis investigates the dynamics of waterborne disease under different conditions and consequently determines ...
    • Models in isotropic coordinates with equation of state. 

      Ngubelanga, Sifiso Allan. (2015-09-04)
      In this thesis we consider spacetimes which are static and spherically symmetric related to the Einstein and Einstein-Maxwell system of equations in isotropic coordinates. We study both neutral and charged matter ...
    • New classes of exact solutions for charged perfect fluids. 

      Mthethwa, Thulani Richard. (2014-03-28)
      We investigate techniques to generate new classes of exact solutions to the Einstein- Maxwell field equations which represent the gravitational field of charged perfect fluid spherically symmetric distributions of ...
    • New models for quark stars with charge and anisotropy. 

      Sunzu, Jefta Mvukaye. (2014)
      We find new classes of exact solutions for the Einstein-Maxwell field equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field ...
    • New realistic solutions for charged matter with an equation of state. 

      Takisa, Pedro Mafa.
      The purpose of this thesis is to provide new exact solutions to the Einstein-Maxwell system which are physically reasonable. We assume that the spacetime is static and spherically symmetric with a charged anisotropic ...
    • Non-circularity of beams in the CMB polarization power spectrum estimation. 

      Ramamonjisoa, Fidy Andriamanankasina. (2015-01-05)
      Precise measurements of the Cosmic Microwave Background (CMB) anisotropies have been one of the foremost concerns in modern cosmology as it provides valuable information on the cosmology of the Universe. However, an ...
    • Nonclassical solutions of hyperbolic conservation laws. 

      Agbavon, Koffi Messan.
      This dissertation studies the nonclassical shock waves which appears as limits of certain type diffusive-dispersive regularisation to hyperbolic of conservation laws. Such shocks occur very often when the ux function ...
    • On new and improved semi-numerical techniques for solving nonlinear fluid flow problems. 

      Makukula, Zodwa Gcinaphi. (2012)
      Most real world phenomena is modeled by ordinary and/or partial differential equations. Most of these equations are highly nonlinear and exact solutions are not always possible. Exact solutions always give a good account ...
    • On singularly perturbed problems and exchange of stabilities. 

      Kimba Phongi, Eddy. (2015)
      Singular perturbation theory has been used for about a century to describe models displaying different timescales, that arise in applied sciences; particularly, models displaying two timescales, namely slow time and fast ...
    • On Stephani universes. 

      Moopanar, Selvandren. (1992)
      In this dissertation we study conformal symmetries in the Stephani universe which is a generalisation of the Robertson-Walker models. The kinematics and dynamics of the Stephani universe are discussed. The conformal ...
    • On the integrity of domination in graphs. 

      Smithdorf, Vivienne. (1993)
      This thesis deals with an investigation of the integrity of domination in a.graph, i.e., the extent to which domination properties of a graph are preserved if the graph is altered by the deletion of vertices or edges or ...
    • On the physical viability of horizon-free collapse. 

      Ntshangase, Mlungisi Alex Doctor. (2015-09-04)
      The so-called Cosmic Censorship Conjecture has drawn widespread attention amongst astrophysicists and particle physicists. In particular, the end-state of gravitational collapse of a bounded matter distribution is a ...