Browsing by Author "Ackora-Prah, Joseph"

Now showing 1 - 9 of 9
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    A comprehensive cost-effectiveness analysis of control of maize streak virus disease with Holling’s Type II predation form and standard incidence
    (Elsevier, 2022-06) Seidu, Baba; Asamoah, Joshua Kiddy K.; Wiah, Eric Neebo; Ackora-Prah, Joseph; 0000-0002-7066-246X
    Maize streak virus disease, caused by the maize streak virus, has been identified as severe vector-borne disease in Africa. In most regions of the continent, the disease is generally uncontrolled, and in epidemic years, it contributes to massive yield losses and famine. We propose a Holling-type predation functional response to explore the disease transmission. We show the sensitivity indices of various embedded parameters in the basic reproduction number. To illustrate the dynamics of the disease of the maize–leafhopper interaction, we perform a numerical simulation, and the results are graphically displayed. Incorporating four control methods (infection control, predation control, removal of infected maize plants, and insecticide application) into the basic model yields an optimal control issue. We used the Incremental Cost-Effectiveness Ratio technique to evaluate the most cost-effective combination of the four controls. We notice that the most cost-effective strategy combines the simultaneous adoption of the four controls.
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    Fractal-Fractional Caputo Maize Streak Virus Disease Model
    (MDPI, 2023-02) Ackora-Prah, Joseph; Seidu, Baba; Okyere, Eric; Asamoah, Joshua Kiddy K.; 0000-0002-7066-246X
    Maize is one of the most extensively produced cereals in the world. The maize streak virus primarily infects maize but can also infect over 80 other grass species. Leafhoppers are the primary vectors of the maize streak virus. When feeding on plants, susceptible vectors can acquire the virus from infected plants, and infected vectors can transmit the virus to susceptible plants. However, because maize is normally patchy and leafhoppers are mobile, leafhoppers will always be foraging for food. Therefore, we want to look at how leafhoppers interact on maize farms using Holling’s Type III functional response in a Caputo fractal-fractional derivative sense. We show that the proposed model has unique positive solutions within a feasible region. We employed the Newton polynomial scheme to numerically simulate the proposed model to illustrate the qualitative results obtained. We also studied the relationship between the state variables and some epidemiological factors captured as model parameters. We observed that the integer-order versions of the model exaggerate the impact of the disease. We also observe that the increase in the leafhopper infestation on maize fields has a devastating effect on the health of maize plants and the subsequent yield. Furthermore, we noticed that varying the conversion rate of the infected leafhopper leads to a crossover effect in the number of healthy maize after 82 days. We also show the dynamics of varying the maize streak virus transmission rates. It indicates that when preventive measures are taken to reduce the transmission rates, It will reduce the low-yielding effect of maize due to the maize streak virus disease.
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    Fractal-fractional order dynamics and numerical simulations of a Zika epidemic model with insecticide-treated nets
    (2022-06) Addai, Emmanuel; Zhang, Lingling; Ackora-Prah, Joseph; Gordon, Joseph Frank; Asamoah, Joshua Kiddy K.; Essel, John Fiifi; 0000-0002-7066-246X
    Fractional order and fractal order are mathematical tools that can be used to model realworld problems. In order to demonstrate the usefulness of these operators, we develop a new fractal-fractional model for the propagation of the Zika virus. This model includes insecticide-treated nets and the generalized fractal-fractional Mittag-Leffler kernel. The existence, uniqueness, and Ulam–Hyres stability conditions for the given system are determined. Using the Newton polynomial, the numerical scheme is described. From the numerical simulations, we notice that a change in the fractal-fractional order directly affects the dynamics of the Zika virus. We also notice that the use of fractal order only converges to faster than the use of fractional order only. Testing the inherent potency of insecticide-treated nets when the fractal-fractional order is 0.99 indicates that increased use of insecticide-treated nets increases the number of healthy humans. The fractalfractional analysis captures the geometric pattern of the Zika virus that is repeated at every scale, which cannot be captured by classical geometry. This backs up the idea that the best way to control the disease is to know enough about how it spread in the past.
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    Fractional-Order Ebola-Malaria Coinfection Model with a Focus on Detection and Treatment Rate
    (Hindawi, 2022-09) Zhang, Lingling; Addai, Emmanuel; Ackora-Prah, Joseph; Dissou Arthur, Yarhands; Asamoah, Joshua Kiddy K.; 0000-0002-7066-246X
    Coinfection of Ebola virus and malaria is widespread, particularly in impoverished areas where malaria is already ubiquitous. Epidemics of Ebola virus disease arise on a sporadic basis in African nations with a high malaria burden. An observational study discovered that patients in Sierra Leone’s Ebola treatment centers were routinely infected with malaria parasites, increasing the risk of death. In this paper, we study Ebola-malaria coinfections under the generalized Mittag-Leffler kernel fractional derivative. The Banach fixed point theorem and the Krasnoselskii type are used to analyse the model’s existence and uniqueness. We discuss the model stability using the Hyers-Ulam functional analysis. The numerical scheme for the Ebolamalaria coinfections using Lagrange interpolation is presented. The numerical trajectories show that the prevalence of Ebolamalaria coinfections ranged from low to moderate depending on memory. This means that controlling the disease requires adequate knowledge of the past history of the dynamics of both malaria and Ebola. The graphical dynamics of the detection rate indicate that a variation in the detection rate only affects the following compartments: individuals that are latently infected with the Ebola, Ebola virus afflicted people who went unnoticed, individuals who have been infected with the Ebola virus and have been diagnosed with the disease, and persons undergoing Ebola virus therapy.
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    Fuel Scheduling by Linear Programming for Volta River Authority (VRA) - Aboadze Thermal Power Plant Project
    (1998-02-14) Ackora-Prah, Joseph
    By means of a Linear Programme (LP) model, an Optimal Fuel Scheduling Scheme has been obtained for the Aboadze Thermal Plant in Takoradi. The model which used weekly power output, Light Crude Oil, (LCO) delivery and inventory of the storage tanks as decision variables was solved using a computer code in Fortran. It was found out that LCO delivery to the two plants should be 25000 barrels to plant t1 and 15000 barrels to plant 2 in the first week, 23000 and 17000 barrels to plant 1 and plant 2 respectively in the second week. In the third week, the scheduled is 23000 and 18000 barrels of LCO to plant I and 2 respectively.. The inventory of the storage tanks at the end of the 3week period for the main problem was 18767 and 12169 barrels of LCO to plant 1 and plant 2 respectively. The optimal solution remained insensitive to 25% Tolerance in the model parameters.
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    Lyapunov stability analysis and optimization measures for a dengue disease transmission model
    (Elsevier, 2022-06) Abidemi, Afeez; Ackora-Prah, Joseph; Fatoyinbo, Hammed Olawale; Asamoah, Joshua Kiddy K.; 0000-0002-7066-246X
    system of ordinary differential equations using dynamical system theory. Appropriate Lyapunov functions are used to carry out an extensive investigation of the global asymptotic dynamics of the model around the dengue-free and dengue-present equilibria. The model is shown to exhibit a forward bifurcation phenomenon using Center Manifold Theory. Sensitivity analysis is carried out to determine the relative importance of the model parameters to the spread of the disease. Using optimal control theory, the model is further extended to a nonlinear optimal control model to explore the impact of four time-dependent control variables, namely, personal protection, treatment drug therapy for latently infected individuals, treatment control for symptomatic individuals and insecticide control for mosquito reduction, on dengue disease dynamics in a population. Cost-effectiveness analysis is conducted on various strategies with combinations of at least three optimal controls to determine the least costly and most effective strategy that can be implemented to contain the spread of dengue in a population.
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    Max-Plus Algebra for Genetic Algorithms
    (2012-08-18) Ackora-Prah, Joseph
    We investigate the redesigning of the general Genetic Algorithms (GAs) using concepts from max-plus algebra...
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    Scattering of kinks in noncanonical sine-Gor Scattering of kinks in noncanonical sine-Gordon Model don Model
    (Turkish Journal of Physics, 2022) Takyi, Ishmael; Barnes, Benedict; Tornyeviadzi, Hoese Michel; Ackora-Prah, Joseph; 0000-0002-1217-0889; 0000-0002-0580-5655; 0000-0001-9488-9610
    In this paper, we numerically study the scattering of kinks in the noncanonical sine-Gordon model using Fourier spectral methods. The model depends on two free parameters, which control the localized inner structure in the energy density and the characteristics of the scattering potential. It has been conjectured that the kink solutions in the noncanonical model possess inner structures in their energy density, and the presence of these yields bound states and resonance structures for some relative velocities between the kink and the antikink. In the numerical study, we observed that the classical kink mass decreases monotonically as the free parameters vary, and yields bion-formations and long-lived oscillations in the scattering of the kink-antikink system. :
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    Vacuum polarization energy of the kinks in the sinh-deformed models
    (Turkish Journal of Physics, 2021) Takyi, Ishmael; Barnes, Benedict; Ackora-Prah, Joseph; 0000-0002-1217-0889; 0000-0002-0580-5655; 0000-0001-9488-9610
    We compute the one-loop quantum corrections to the kink energies of the sinh-deformed 4 and 6 models in one space and one time dimensions. These models are constructed from the well-known polynomial 4 and 6 models by a deformation procedure. We also compute the vacuum polarization energy to the nonpolynomial function = 1 4 (1 − sinh2 .This potential approaches the model in the limit of small values of the scalar function. These energies are extracted from scattering data for fluctuations about the kink solutions. We show that for certain topological sectors with nonequivalent vacua the kink solutions of the sinh-deformed models are destabilized.