Browsing Faculty of Natural Sciences by Subject "Mathematics"
Now showing items 1-20 of 23
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An unconditionally stable nonstandard finite difference method applied to a mathematical model of HIV infection
(De Gruyter Open, 2013)We formulate and analyze an unconditionally stable nonstandard finite difference method for a mathematical model of HIV transmission dynamics. The dynamics of this model are studied using the qualitative theory of dynamical ... -
Analyzing chemical data in more than two dimensions: A tutorial on factor and cluster analysis
(Journal of chemical education, 1990)This tutorial is intended to introduce factor and cluster analysis at a level that will afford a senior student-and the practicing chemist, for that matter-some insights into the workings of the computer packages employing ... -
Automorphism groups of graph covers and uniform subset graphs
(Taylor and Francis Group, 2018)Hofmeister considered the automorphism groups of antipodal graphs through the exploration of graph covers. In this note weextend the exploration of automorphism groups of distance preserving graph covers. We apply the ... -
Binary codes from m-ary n-cubes Q(n) (m)
(American Institute of Mathematical Sciences, 2021)We examine the binary codes from adjacency matrices of the graph with vertices the nodes of the m-ary n-cube Qmn and with adjacency de ned by the Lee metric. For n = 2 and m odd, we obtain the parameters of the code and ... -
Control and elimination in an SEIR model for the disease dynamics of Covid-19 with vaccination
(AIMS Press, 2023)COVID-19 has become a serious pandemic affecting many countries around the world since it was discovered in 2019. In this research, we present a compartmental model in ordinary differential equations for COVID-19 with ... -
A fitted numerical method for parabolic turning point singularly perturbed problems with an interior layer
(Wiley, 2019)The objective of this paper is to construct and analyzea fitted operator finite difference method (FOFDM) forthe family of time-dependent singularly perturbed parabolicconvection–diffusion problems. The solution to the ... -
Generalizing the Hilton–Mislin genus group
(Elsevier, 2001)For any group H, let H be the set of all isomorphism classes of groups K such that K H . For a finitely generated group H having finite commu- Ž .tator subgroup H, H , we define a group structure on H ... -
Mathematical study of transmission dynamics of SARS-CoV-2 with waning immunity
(AIMS Press, 2022)The aim of this work is to provide a new mathematical model that studies transmission dynamics of Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The model ... -
Maths4Stats: Opleiding vir onderwysers
(AOSIS, 2013)Maths4Stats: Educating teachers. The inadequate nature of the education infrastructure in South Africa has led to poor academic performance at public schools. Problems within schools such as under-qualified teachers and ... -
Modeling the impact of combined use of Covid Alert SA app and vaccination to curb Covid-19 infections in South Africa
(Public Library of Science, 2023)The unanticipated continued deep-rooted trend of the Severe Acute Respiratory Syndrome Corona-virus-2 the originator pathogen of the COVID-19 persists posing concurrent anxiety globally. More effort is affixed in the ... -
Multicolour time series photometry of the variable star 1SWASP J234401.81−212229.1
(Oxford University Press, 2014)1SWASP J234401.81-212229.1 may be one of a handful of contact binaries comprising two Mdwarfs. Modelling of the available observations is complicated by the fact that the radiation of the eclipsing system is dominated ... -
Multimodality and new materialism in science learning: Exploring insights from an introductory physics lesson
(Unisa Press, 2021)Science disciplines are inherently multimodal, involving written and spoken language, bodily gestures, symbols, diagrams, sketches, simulation and mathematical formalism. Studies have shown that ... -
Multiplication of Crowns
(Instituto de Matematica de Bahia Blanca (INMABB-CONICET), 2013)It is known that the only nite topological spaces that are H-spaces are the discrete spaces. For a nite poset which is weakly equivalent to an H-space, a generalized multiplication may be found after suitable ... -
A NSFD discretization of two-dimensional singularly perturbed semilinear convection-diffusion problems
(Frontiers Media, 2022)Despite the availability of an abundant literature on singularly perturbed problems, interest toward non-linear problems has been limited. In particular, parameter-uniform methods for singularly perturbed semilinear ... -
A NSFD method for the singularly perturbed Burgers-Huxley equation
(Frontiers Media, 2023)This article focuses on a numerical solution of the singularly perturbed Burgers-Huxley equation. The simultaneous presence of a singular perturbation parameter and the nonlinearity raise the challenge of finding a ... -
On maximal inequalities via comparison principle
(SpringerOpen, 2015)Under certain conditions, we prove a new class of one-sided, weighted, maximal inequalities for a standard Brownian motion. Our method of proof is mainly based on a comparison principle for solutions of a system of ... -
On the exact constants in one-sided maximal inequalitiesfor Bessel processes
(Taylor and Francis Group, 2023)In this paper, we establish a one-sided maximal moment inequalitywith exact constants for Bessel processes. As a consequence, weobtain an exact constant in the Burkholder-Gundy inequality. Theproof of our main result is ... -
On the time delay between ultra-relativistic particles
(Elsevier, 2016)The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through ... -
Performance of Richardson extrapolation on some numerical methods for a singularly perturbed turning point problem whose solution has boundary layers
(KOREAN MATHEMATICAL SOC, 2014)Investigation of the numerical solution of singularly perturbed turning point problems dates back to late 1970s. However, due to the presence of layers, not many high order schemes could be developed to solve such problems. ... -
Periodic low-frequency electric field structures in a magnetized non-thermal auroral plasma
(Elsevier, 2019)The theoretical explanation of electric field structures associated with density depletion in the Earth’s upper ionosphere is presented. Using the quasi-neutrality hypothesis, the effect of excess energetic electron ...