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Item Open Access A Comparative Study of Box-Jenkins, Arima, Holt-Winter and Exponential Smoothing Models as Applied to Exchange Rate on Naira to Dollar(Department of Mathematics, Nasarawa State University Keffi, 2005-01-06) Umar, Mallam AbdulkarimItem Open Access Effect of Vaccination, Treatment and Population Area Size on the Transmission Dynamics of Tuberculosis in a Proportionate Mixing Population(Department of Mathematics, Nasarawa State University Keffi, 2007-01-06) Umar, Mallam AbdulkarimItem Open Access Effect of Vaccination, Treatment and Population Area Size on the Transmission Dynamics of Bird-Flu Epidemics in a Proportiona,(Department of Mathematics, Nasarawa State University Keffi, 2007-01-06) Umar, Mallam AbdulkarimWe have examined the effect of vaccination, nnrl population nren size on the transmission dynamics oT bird flu epidemics in a poultry farm, using two class of models, an age -structured epidemic model and n homogeneous epidemics model in which the transmission rate in the ease of homogeneous model, is assumed not age-depended, while it is assumed age-dependent in the agc-struclurcd model. The per capital contact rate and the vital rates arc assumed not age depended. It is observed in both eases, that llic area size occupied by the population influences the rate of transmission of the virus. Wild birds, which arc normally on free range, arc observed to be responsible for the spread of the virus to poultry farms; however the transmission rate may be less than in poultry birds, due to their free range nature. This is not investigated this work. This is assumed to has helped to control the concentration of the wild birds population density in n particular location, where they arc found, and less per cnpilnl contact rale. Thus, the disease spread is minimal. Threshold parameters for both models arc examined to determine the stability of the non -trivial steady stales.Item Open Access Two Sex Model for Horizontal Transmission of STD in a Constants Homogeneous mixing population(Department of Mathematics, Nasarawa State University Keffi, 2007-01-06) Umar, Mallam AbdulkarimIn this paper, we examined llic two sex model ofl-lsich4 and Kimbir cl a/..', and extended these models to study transmission dynamics of socially ti'nnsmitlcd diseased STD ) in a proportional mixing population with vital dynamics, and no disease induced death. Our major focus is to reduce the cost of disease intervention towards eradication of curable STD. like gonorrhea and others, which is heller achieved through preventive measure rather than Irentmenl. a concept dial is cheaper and affordable, in developing economies like ours. We have proposed a variant of the Kimbir el a/..5 model of prevention of 111 V / AIDS in a varying population to study the transmission dynamics of STD. Stability of the equilibriums slates lire discussed via the reproductive ratio of the infection and the Routh -1 Iunviiz.conditions on the model parameters. Threshold conditions for eradication and persistent of the disease arc derived nod interpre tation are discussed. 'Item Open Access Age-Structures Epidemic Model for Transmission Dynamics of Tuberculosis(Department of Mathematics, Nasarawa State University Keffi, 2007-02-02) Umar, Mallam AbdulkarimItem Open Access Mathematical Model for Vertical Transmission of HIV/AIDS, in a Homogeneous Mixing Population(Department of Mathematics, Nasarawa State University Keffi, 2007-03-03) Umar, Mallam Abdulkarim; Ndakwo, Husseini S.Item Open Access Age-Structured Transmission Dynamics Model for Vertical and Horizontal Transmission of HIV/AIDS(Department of Mathematics, Nasarawa State University Keffi, 2008-01-06) Umar, Mallam Abdulkarim; Olowofeso, E.O.; Ademiluyi, R.A.Transmission dynamics model for -HlV/AlDS, along the line of Mckendrick-Forester age-structured model is proposed with the natural mortality rate and the fertility functions assumed to bE age depended, similar, to Doma, Gurlin-MacCnmy definitions. The solution^ to the governing equations are obtained and the steady stales are examined for their local stability. The model is further extended to study the case of constant mortality . rate and an exponential type of interaction function. It is observed that the endemic steady'.exist, and. .. asymptotically stable.Item Open Access Modeling Horizontal Transmission of HIV/AIDS in an Age-Structured Population(Department of Mathematics, Nasarawa State University Keffi, 2008-01-08) Umar, M.A.; Olowofeso, E.O.; Ademiluyi, R.A.Item Open Access The Dynamics of Natural Mortality, Life Expectancy and TB in an Structured Population.(Department of Mathematics, Nasarawa State University Keffi, 2008-01-09) Umar, Mallam AbdulkarimWe have extended live classical Mckcndriok-Focrstcr age structured population model to study the olicet ol population area size on the transmission dynamics of tuberculosis in an ngo*otniciurccl population, in wliicli infective recovers, nfior irontmontond bocomo suscoptiblo again when in contact with Die disease. The natural mortality rate J3 assumed density mid nren size depended, wiUi the population assumed lo be in propoi tionm.0 mixing. Wo defined n niodol in which tlie area sizes and the total population influences the rale at. which death by nature in 1110 population. This model is extended to study Iho influence the area size of the population has on the natural mortality rate, life expectancy of the population and the transmission dynamics oT the infection. The analytical solutions of the governing equations arc obtained. The existence of the non trivial a toady .states in oxnminod with their local and global .stability.Item Open Access HARNESSING VIRTUAL CLASSROOM SYSTEM AS AN ALTERNATIVE FOR PART-TIME STUDIES IN NIGERIA(Department Of Mathematics, Nasarawa State University Keffi., 2011-09-26) Chaku, Shammah Emmanuel; Anyachebelu, Tochukwu Kene; Offiong, N.M.The clamour for higher education is on the increase globally, precisely, there is great need for higher education in Nigeria. For this mere fact, there was great need for part-time studies in the Nigerian universities. This need was short lived when the governing body of the Nigerian Universities; Nigerian University Commission (NUC) put a stop to this viable means of acquiring knowledge. The hope of Nigerians was salvaged with the advancement in technology, especially in the area of Information and Communication Technology (ICT). With these inventions, we have what is known as the virtual classroom (VC), a medium that works like the traditional classroom system. The virtual class room is a teaching and learning environment located within a computer-mediated communication system which supports collaborative learning. The virtual classroom has three prominent components: A Virtual Instructor, a Server and Virtual Students. These three components interact together to form the Virtual Classroom System (VCS). This paper shows how virtual classroom can be harnessed as a replacement for part-time studies in Nigeria with the aid of synchronous and asynchronous tools. The virtual instructor sends lecture notes and materials through the server (internet) and the virtual student receives the note and sends feed back through the server. The server here serves as the point of contact between the virtual lecturer and the virtual student just like what is obtainable in a traditional classroom.Item Open Access Modeling Vaccination and Treatment of HTV/AIDS Epidemics in an Age-Structured Population A(Department of Mathematics, Nasarawa State University Keffi, 2011-10-10) Umar, Mallam AbdulkarimWe proposed a deterministic age- structured vaccination and treatment model of HIV and AIDS, along the line oflvlcCamy - Foester age-structured population model, with structured population. compartments and-class dependent Activity level (interaction functions), per-capital force of infection, natural mortality rate and disease • induced death rate . The models equations Are reduced to ordinary differential equations. Their, steady state solutions are obtained and examined for local stability. The, disease-free state is found to be stable if vaccination and removal rates are simultaneously maximized. This will lend to a corresponding decrease in the size of HIV infected individuals and the number of infected cases progressing to AIDS.Item Open Access MODELING THE DYNAMICS OFT4-CELLS COUNTS IN AN HIV-INFECTED INDIVIDUAL(Department of Mathematics, Nasarawa State University Keffi, 2011-11-11) Umar, Mallam Abdulkarim; Ndakwo, Husseini S.In this work, w e examined, the stages of HIV progression to AI DS and proposed .a stochastic model of • the number of T 4 - cells counts in an HIV infected person. Tlie mean number of 14 - cells in each disease, phase is obtained and the conditions for a stable level of CD +4 — lymphoc^'te cells in an infected host are suggested. TIic need for antiretroviral therapies to sustain this level is emphasized.Item Open Access A Continuous Time Mathematical Model for Retiring Lecturers in the Nigerian Universities: A Case Study, of Nasarawa State University, Keffi, Nigeria(Department of Mathematics, Nasarawa State University Keffi, 2012-01-03) Ndakwo, Husseini S.; Muhammad, A.Y.; Umar, M.A.In this .paper, an attempt vas made to formulate a continuous tunc Mathematical model dial will solve the problems'confronting Lecturers towards and during re them end Onnh, E.S. and Mser, M.D.(2003) Mathematical Association of Nigeria worked on the general Mathematical Model for retiring workers. 'The income of a Professor and. a. Graduate Assistant in a Nigerian University was used in-the numerical example.Item Open Access Transport System Effects On. Cross Diffusion(Department of Mathematics, Nasarawa State University Keffi, 2013-01-06) Ndakwo, Husseini S.; Umar, Mallam Abdulkarim; Muhammad, A.Y.Cross diffusion is a phenomena in which a gradient in the concentration of one species induces a flux of another chemical species which was generally been neglected in the study of reaction-diffusion systems. We study the Turing bifurcation of two species reaction transport systems, where particle dispersal is governed by diffusion and cross diffusion, we performed linear stability apglysis to find tKc conditions for the Turing instability and compare results with the standard Turing conditions and we applied our results to'one model system, the Schnakenberg reaction Kinetics to see it effects on cross diffusion.Item Open Access A RESPONSE SURFACE OUTLOOK FOR OPTIMALITY IN RICE PRODUCTION IN THE NORTHERN NIGERIA STATE OF KANO(Department of Mathemaics, Nasarawa State University, Keffi., 2014-01-01) Adehi, Mary Unekwu; Dikko, H. G.; David, I. J.With the aid o f response surface methodology a response surface model was developed for a mixed level two factors (irrigation at 3 levels and fertilizer at 4 levels) experimental design on rice yield in Kano State which is situated in the northern part o f Nigeria. A quadratic surface was fitted and a canonical analysis was carried out to determine the surface in the region of maximum. Goodness off it tests was performed in assessing the model where the R~, adjusted-R2, and residual plots were done and it was revealed that the model is adequate.Item Open Access Influence of Environmental Pollution on the Transmission Dynamics of Infections(Department of Mathematics, Nasarawa State University Keffi, 2014-01-06) Umar, Mallam AbdulkarimItem Open Access A Global Stability Analysis of a Susceptible-Infected-Removed-Prevented-Controlled Epidemic Model(Department of Mathematics, Nasarawa State University Keffi, 2014-03-06) Muhammad, Yau A.; Ndakwo, Husseini S.; Umar, Mallam AbdulkarimA mathematical model off HIV transmission dynamics Is proposed and analysed. The population is partitioned into five compartments of susceptible 5(C),Infected I{£), Removed rtp), .Prevented* t/(C) and the Controlled W(t). Each of the compartments comprises of cohort of individuals. Five sys tems of nonlinear equations are derived to represent each of the compartments. The general bility of the disease free equilibrium (DFE) and the endemic equilibrium states of the linearized model are established using the linear stability analysis (Routh-Hurwitz) method which is found to be locally asymptotically stable when the Infected individuals receive ART and use the condom. The reproduction number is also derived using the idea of Diekmann and is found to be strictly less than one. This means that the epidemic will die out.Item Open Access A Class of Block Multi-Step Methods for the Solutions of Ordinary Differential Equation (Ode)(Department of Mathematical Science, Nasarawa State University Keffi., 2016-04-13) Nweze, N.O.; Chaku, Shammah Emmanuel; Offiong, M.N.; Maijamaa, BilkisuIn this research, an attempt is made to derive a self starting block procedure for some K-step linear multi-step methods (for K=1, 2 and 3), using Chebyshev polynomial as the basis function. The continuous interpolant were derived and collocated at grid and off-grid points to give the discrete methods used in block and applied simultaneously for the solution of non stiff initial value problem.The regions of absolute stability of the methods are plotted and are shown to be A (α) stable. The methods for K=2 and K=3 were experimented on initial value problems and the results reveal that the newly constructed block methods have good error stability and are efficient.Item Open Access Validating Numerical to Theoretical Solutions in a \Reaction-Diffusion with Linear Cross-Diffusion Systems.(Department of Mathematics, Nasarawa State University Keffi, 2020-07-20) Ndakwo, Husseini S.; Umar, Mallam Abdulkarim; Bello, Sulayman M.In tliis paper, we consider a reaction diffusion system with linear cross-diffusion. We carry‘out the analytical study in detail and find out that, when the diffusion coefficient is unity, Turing instability does not occur, but with the introduction of cross-diffusion, the system exhibit Turing instability. The numerical results reveal that, on increasing the value of, there is an occurrence of spatial patterns which conforms with the theoretical results. The cross-diffusion coefficients really play a vitaj role on the parameter spaces and spatial patterns of our system,Item Open Access Effects of minimum epidemic and population sizes on a global epidemic in simulations of final size data(Department of Mathematics, Nasarawa State University Keffi, 2020-08-08) Umar, Mallam Abdulkarim; Ndakwo, Husseini S.The stochastic SIR household epidemic model is well discussed in [2], [3] and [4]. The work of [1] • also proposed maximum likelihood based algori hm for its inference by assuming independence of epidemic in each household, contrary to the dependency assn uption in [4]. 8 ° * Using simulations, we examined the ne id for an appropriate choice of cut-off between small and large epidemics often referred to as minimum epidemic size, using rejection sampling, for a global infection to occur and then compared the estimates of the model parameters over a range of theoretical parameters, XL and Xc with corresponding z 6 [0,1]. We found that with large population size, appropriate choice of the minimum epidemic size and Xc =£ 0 facilitate the occurrence of a global epidemic. Thus, given these scenarios, the adequacy of the model fitness to the final size epidemic data is then realised.