Now showing items 41-60 of 69

    • A note on the stochastic version of the Gronwall lemma 

      Makasu, Cloud (Taylor & Francis Group, 2022)
      We prove a stochastic version of the Gronwall lemma assuming that the underlying martingale has a terminal random value in Lp, where 1 p < 1: The proof of the present result is mainly based on a sharp martingale inequality ...
    • A NSFD discretization of two-dimensional singularly perturbed semilinear convection-diffusion problems 

      Kehinde, Olawale O.; Munyakazi, Justin B.; Appadu, Appanah R. (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 

      Derzie, Eshetu B.; Munyakazi, Justin B.; Dinka, Tekle G. (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 reliable ...
    • A NSFD method for the singularly perturbed Burgers-Huxley equation 

      Derzie, Eshetu B.; Munyakazi, Justin B.; Dinka, Tekle G. (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 ...
    • Numerical solution for a problem arising in angiogenic signalling 

      Kolade, Owolabi; Kailash, Patidar; Shikongo, Albert (American Institute of Mathematical Sciences, 2019)
      Since the process of angiogenesis is controlled by chemical signals, which stimulate both repair of damaged blood vessels and formation of new blood vessels, then other chemical signals known as angiogenesis inhibitors ...
    • Numerical treatment of Kap's equation using a class of fourth order method 

      Akanbi, M.A.; Okunuga, S.A.; Sofoluwe, A.B. (Academic Journals, 2011)
      Kap's equation is a stiff initial value problem. This paper deals with the treatment of Kap's equation using a class of 4th order explicit Runge-Kutta method. Numerical computation was carried out using Microsoft Visual ...
    • On maximal inequalities via comparison principle 

      Makasu, Cloud (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 

      Makasu, Cloud (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 ...
    • One-sided maximal inequalities for a randomly stopped bessel process 

      Cloud, Makasu (Taylor & Francis Group, LLC, 2023)
      We prove a one-sided maximal inequality for a randomly stopped Bessel process of dimension (Formula presented.) For the special case when α = 1, we obtain a sharp Burkholder-Gundy inequality for Brownian motion as a ...
    • An optimal portfolio and capital management strategy for basel III compliant commercial banks 

      Muller, Grant E.; Witbooi, Peter J. (Hindawi Publishing Corporation, 2014)
      We model a Basel III compliant commercial bank that operates in a financial market consisting of a treasury security, a marketable security, and a loan and we regard the interest rate in the market as being stochastic. We ...
    • Optimal strategy for controlling the spread of HIV/AIDS disease: A case study of South Africa 

      Yusuf, Tunde T.; Benyah, Francis (Taylor and Francis Group, 2012)
      HIV/AIDS disease continues to spread alarmingly despite the huge amounts of resources invested infighting it. There is a need to integrate the series of control measures available to ensure a consistentreduction ...
    • Performance of Richardson extrapolation on some numerical methods for a singularly perturbed turning point problem whose solution has boundary layers 

      Munyakazi, Justin B.; Patidar, Kailash C. (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. ...
    • Protein interaction networks as metric spaces: A novel perspective on distribution of hubs 

      Fadhal, Emad; Gamieldien, Junaid; Mwambene, Eric C (BMC, 2014)
      In the post-genomic era, a central and overarching question in the analysis of protein-protein interaction networks continues to be whether biological characteristics and functions of proteins such as lethality, physiological ...
    • Quasi-uniform structures determined by closure operators 

      Holgate, D; Iragi, M (Elsevier, 2021)
      We demonstrate a one-to-one correspondence between idempotent closure operators and the so-called saturated quasi-uniform structures on a category C. Not only this result allows to obtain a categorical counterpart P of the ...
    • Relative homotopy in relational structures 

      Witbooi, Peter (Cambridge University Press, 2018)
      The homotopy groups of a finite partially ordered set (poset) can be described entirely in the context of posets, as shown in a paper by B. Larose and C. Tardif. In this paper we describe the relative version of such a ...
    • A robust numerical solution to a time-fractional Black–Scholes equation 

      Nuugulu, S.M; Gideon, F; Patidar, K.C (Springer Nature, 2021)
      Dividend paying European stock options are modeled using a time-fractional Black–Scholes (tfBS) partial differential equation (PDE). The underlying fractional stochastic dynamics explored in this work are appropriate for ...
    • A robust spectral method for pricing of American put options on zero-coupon bonds 

      Pindza, Edson; Patidar, Kailash C. (Global-Science Press, 2018)
      American put options on a zero-coupon bond problem is reformulated as a linear complementarity problem of the option value and approximated by a nonlinear partial differential equation. The equation is solved by an ...
    • A robust spectral method for solving Heston’s model 

      Ngounda, E.; Patidar, Kailash C.; Pindza, E. (Springer Verlag, 2014)
      In this paper, we consider the Heston’s volatility model (Heston in Rev. Financ. Stud. 6: 327–343, 1993]. We simulate this model using a combination of the spectral collocation method and the Laplace transforms method. ...
    • An SEIR model with infected immigrants and recovered emigrants 

      Witbooi, Peter J. (Springer Science and Business Media Deutschland GmbH, 2021)
      We present a deterministic SEIR model of the said form. The population in point can be considered as consisting of a local population together with a migrant subpopulation. The migrants come into the local population for ...
    • An SEIRS epidemic model with stochastic transmission 

      Witbooi, Peter J. (Springer, 2017)
      For an SEIRS epidemic model with stochastic perturbations on transmission from the susceptible class to the latent and infectious classes, we prove the existence of global positive solutions. For sufficiently small values ...