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Determination Of Cramer-Rao Lower Bound (Crlb) And Minimum Variance Unbiased Estimator Of A Dc Signal In Awgn Using Laplace Transform, Abdi T. Abdalla Dec 2021

Determination Of Cramer-Rao Lower Bound (Crlb) And Minimum Variance Unbiased Estimator Of A Dc Signal In Awgn Using Laplace Transform, Abdi T. Abdalla

Tanzania Journal of Science

This paper presents an alternative approach for the determination of Cramer-Rao Lower Bound (CRLB) and Minimum Variance Unbiased Estimator (MVUE) using Laplace transformation. In this work, a DC signal in Additive White Gaussian Noise (AWGN) was considered. During the investigation, a number of experiments were conducted to analyze different possible outputs under different conditions, and then the patterns of the outcomes were studied. Finally closed-form expressions for the CRLB and MVUE were deduced employing the Laplace transformation. The resulting expressions showed that the proposed method has almost the same number of steps as the existing method. However, the latter requires …


Improved Modified Ratio Estimation Of Population Mean Using Information On Size Of The Sample, Sikiru A Suleiman, Amos A Adewara Dec 2021

Improved Modified Ratio Estimation Of Population Mean Using Information On Size Of The Sample, Sikiru A Suleiman, Amos A Adewara

Tanzania Journal of Science

In sample surveys, auxiliary information is used for estimation to improve the efficiency of estimators. Increased precision can be obtained when the variable under study is highly correlated with auxiliary information. In this study, the sample size has been used as information for improved estimation of population mean of the main variable under study. A new modified generalized ratio type estimator of population mean has been proposed and the efficiency was examined using Murthy (1967) and Mukhopadhyay (2009) dataset. The large sample properties, the bias and the mean squared error of the newly proposed modified ratio estimator were obtained up …


Mitigating The Spread Of Measles Under Constrained Health Care Resources In Tanzania Using Social Contact Network Models, Herieth Rwezaura, Seán Mcgarraghy Dec 2021

Mitigating The Spread Of Measles Under Constrained Health Care Resources In Tanzania Using Social Contact Network Models, Herieth Rwezaura, Seán Mcgarraghy

Tanzania Journal of Science

Tanzania revaccinates individuals during measles outbreaks, despite having scant healthcare resources. We construct epidemiological models of measles spread by employing a hybrid of existing social contact networks models to develop SEIR simulation model. Using demographic and measles surveillance data from three rural villages in Tanzania, we simulate the spread of measles and examine which vaccination strategies can effectively control outbreaks. Results strongly indicate the spread of measles largely depends on contact rates among infected individuals within a population. Findings indicate a need for targeted vaccination for children of 6 months to 15 years of age, but equally for unvaccinated older …


Modelling The Impact Of Undetected Cases On The Transmission Dynamics Of Covid-19, Herieth Rwezaura Dec 2021

Modelling The Impact Of Undetected Cases On The Transmission Dynamics Of Covid-19, Herieth Rwezaura

Tanzania Journal of Science

The spread of COVID-19 globally has caused negative impacts to the public, making understanding the dynamics of transmission a necessity. Essential factors such as undetected cases, asymptomatic cases, and several non-pharmaceutical interventions have played significant roles in the spreading mechanism of COVID-19 in the human population. It is imperative to understand the significance of these factors in order to determine whether COVID-19 will be eradicated or will continue to persist in the population. A mathematical model is formulated to investigate the impacts of vaccination and several non-pharmaceutical interventions on the dynamics of a COVID-19 accounting for asymptomatic cases, detected (identified) …


Application Of Faulkenberry (2018) Bayes Factor To A Balanced Two Way Analysis Of Variance With Random Effects, Onyeike D. Egburonu, Omotayo A. Abidoye Dec 2021

Application Of Faulkenberry (2018) Bayes Factor To A Balanced Two Way Analysis Of Variance With Random Effects, Onyeike D. Egburonu, Omotayo A. Abidoye

Tanzania Journal of Science

The Analysis of Variance technique estimates variance components by comparing their mean squares to their expected values. Nevertheless, this method could give variance component estimates that are found outside the parameter space, i.e. negative estimates. In a bid to overcome this deficiency, alternate approaches are essential, and likelihood-based approaches have become common over time. Bayesian techniques have also been proposed and Bayes factors developed for examining various models. We applied the Bayes factor proposed by Faulkenberry (2018) to a Balanced Two Way ANOVA under three (3) cases, namely Case 1: the levels of the two factors are fixed; Case 2: …


Mathematical Characterization Of Biological Control Of Cassava Pests Model, Yidiat O. Aderinto, Faith O. Ibiwoye, Michael O. Oke, Folashade M. Jimoh Dec 2021

Mathematical Characterization Of Biological Control Of Cassava Pests Model, Yidiat O. Aderinto, Faith O. Ibiwoye, Michael O. Oke, Folashade M. Jimoh

Tanzania Journal of Science

Pests are major constraints to the effective growth and development of every crop through their damage, and can be controlled effectively by the use of their natural enemies which is referred to as the biological pest control. In this study, the biological control model of cassava pests through optimal control theory was presented in order to minimize the population of the pests and stabilize the natural enemies population so as not to affect the crop negatively. A mathematical model was formulated via the Lotka-Volterra model, and the model was characterized. The optimality system was established, the equilibrium point with its …


Effects Of Refuge Prey On Stability Of The Prey-Predator Model Subject To Immigrants: A Mathematical Modelling Approach, Mussa Amos Stephano, Il Hyo Jung Oct 2021

Effects Of Refuge Prey On Stability Of The Prey-Predator Model Subject To Immigrants: A Mathematical Modelling Approach, Mussa Amos Stephano, Il Hyo Jung

Tanzania Journal of Science

Prey-predator system is enormously complex and nonlinear interaction between species. Such complexity regularly requires development of new approaches which involves more factors in analysis of its population dynamics. In this paper, we formulate a modified Lotka-Volterra model that incorporates factors such as refuge prey and immigrants. We investigate the effects of refuge prey and immigrants by varying the refuge factor, with and without immigrants. The results show that with Holling’s type I functional response, the proposed model is asymptotically convergent when a refuge prey factor is introduced. Moreover, with Holling’s type II functional response, the proposed mathematical model is unstable …


A Mathematical Analysis Of An In-Vivo Ebola Virus Transmission Dynamics Model, Seleman Ismail, Adeline Peter Mtunya Oct 2021

A Mathematical Analysis Of An In-Vivo Ebola Virus Transmission Dynamics Model, Seleman Ismail, Adeline Peter Mtunya

Tanzania Journal of Science

Ebola virus (EBOV) infection is a hemorrhagic and hazardous disease, which is among the most shocking threats to human health causing a large number of deaths. Currently, there are no approved curative therapies for the disease. In this study, a mathematical model for in-vivo Ebola virus transmission dynamics was analyzed. The analysis of the model mainly focused on the sensitivity of basic reproductive number,  pertaining to the model parameters. Particularly, the sensitivity indices of all parameters of  were computed by using the forward normalized sensitivity index method. The results showed that a slight change in the infection rate immensely influences …


A Susceptible Exposed Infected Recovered Susceptible (Seirs) Model For The Transmission Of Tuberculosis, Latifat M Erinle-Ibrahim, Waheed O Lawal, Olukayode Adebimpe, Gbemisola R Sontan Aug 2021

A Susceptible Exposed Infected Recovered Susceptible (Seirs) Model For The Transmission Of Tuberculosis, Latifat M Erinle-Ibrahim, Waheed O Lawal, Olukayode Adebimpe, Gbemisola R Sontan

Tanzania Journal of Science

In this paper, a deterministic mathematical model was proposed and analyzed to understand the dynamics of tuberculosis based on the SEIRS model. The disease-free equilibrium, the endemic equilibrium, and their stabilities were examined. The R0 (basic reproduction number) was derived using the Next Generation Matrix method and its sensitivity analysis showed that the birth rate and infectious rate were the most sensitive parameters of R0. The behaviour of exposed individuals at the latent period with varied treatment rates were examined through numerical simulation. From the analysis carried out, the effect of variations of the treatments of latent TB shows that …


Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima Aug 2021

Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima

Tanzania Journal of Science

A two-level facility location problem (FLP) has been studied in the transportation network of emergence maize crop in Tanzania. The facility location problem is defined as the optimal location of facilities or resources so as to minimize costs in terms of money, time, distance and risks with the relation to supply and demand points. Distribution network design problems consist of determining the best way to transfer goods from the supply to the demand points by choosing the structure of the network such that the overall cost is minimized. The three layers, namely production centres (PCs), distribution centres (DCs) and customer …


Maintenance Automation Architecture And Electrical Equipment Fault Prediction Method In Tanzania Secondary Distribution Networks, Hadija Mbembati, Kwame Ibwe, Baraka Maiseli Aug 2021

Maintenance Automation Architecture And Electrical Equipment Fault Prediction Method In Tanzania Secondary Distribution Networks, Hadija Mbembati, Kwame Ibwe, Baraka Maiseli

Tanzania Journal of Science

Distribution networks remain the most maintenance-intensive parts of power systems. The implementation of maintenance automation and prediction of equipment fault can enhance system reliability while reducing the overall costs. In Tanzania, however, maintenance automation has not been deployed in secondary distribution networks (SDNs). Instead, traditional methods are used for condition prediction and fault identification of power assets (transformers and power lines). These (manual) methods are costly and time-consuming, and may introduce human-related errors. Motivated by these challenges, this work introduces maintenance automation into the network architecture by implementing effective maintenance and fault identification methods. The proposed method adopts machine learning …


High Speed Hill Climbing Algorithm For Portfolio Optimization, Collether John Aug 2021

High Speed Hill Climbing Algorithm For Portfolio Optimization, Collether John

Tanzania Journal of Science

Portfolio can be defined as a collection of investments. Portfolio optimization usually is about maximizing expected return and/or minimising risk of a portfolio. The mean-variance model makes simplifying assumptions to solve portfolio optimization problem. Presence of realistic constraints leads to a significant different and complex problem. Also, the optimal solution under realistic constraints cannot always be derived from the solution for the frictionless market. The heuristic algorithms are alternative approaches to solve the extended problem. In this research, a heuristic algorithm is presented and improved for higher efficiency and speed. It is a hill climbing algorithm to tackle the extended …


Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi Aug 2021

Spatial Modelling For Cholera Incidence Rates In Morogoro Municipality, Tanzania, Caroline Ngereza, Rosalia S. Katapa, Ali R. Mniachi

Tanzania Journal of Science

Spatial modelling was conducted to examine community factors associated with cholera incidence rates in Morogoro Municipality. The study employed both secondary (cholera cases) and primary (geographic coordinates of community risk factors) data. Spatial lag model was applied in examining association between the variables. All wards of Morogoro Municipality were considered in the study to capture their variations because cholera cases have a tendency to be clustered. Results indicated that market density, distance to the market and distance to the dumpster are significant factors associated with cholera incidence rates in the wards (p < 0.05). Geographically weighted Poisson model was used to show the variations of those factors between the wards in Municipality. A statistically significant positive association of cholera incidence rates; and market density was only found in Mazimbu ward (p < 0.05) and distance from the community to the dumpster was found in Kihonda, Kingolwira, Bigwa, Kichangani, Kilakala and Boma wards (p < 0.001) and some wards at the centre of the municipality which are Mji Mkuu and Kingo (p < 0.05). A statistically significant negative association of cholera incidence rates and distance from the centre of the community to the market was found in Kihonda, Kingolwira and Kichangani (p < 0.001) and Bigwa wards (p < 0.05). Therefore, measures taken to control and prevent cholera disease should base on the variations of the risk factors found in the Municipal wards.  Keywords:    Cholera incidence rate, Spatial lag regression model, Community risk factor, Geographically weighted Poisson model


Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku Aug 2021

Determination Of Quantile Range Of Optimal Hyperparameters Using Bayesian Estimation, Ayoade I. Adewole, Olusoga A. Fasoranbaku

Tanzania Journal of Science

Bayesian estimations have the advantages of taking into account the uncertainty of all parameter estimates which allows virtually the use of vague priors. This study focused on determining the quantile range at which optimal hyperparameter of normally distributed data with vague information could be obtained in Bayesian estimation of linear regression models. A Monte Carlo simulation approach was used to generate a sample size of 200 data-set. Observation precisions and posterior precisions were estimated from the regression output to determine the posterior means estimate for each model to derive the new dependent variables. The variances were divided into 10 equal …


Robust Trilateration Based Algorithm For Indoor Positioning Systems, Simeon Pande, Kwame S Ibwe Aug 2021

Robust Trilateration Based Algorithm For Indoor Positioning Systems, Simeon Pande, Kwame S Ibwe

Tanzania Journal of Science

Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used in self-navigating robots and helping hands. To obtain position information, positioning algorithms employing Received Signal Strength Indicator (RSSI) are of great benefits since they reuse the existing radio wireless infrastructures for indoor positioning. However, the changes in the indoor environment decrease the overall accuracy of the developed indoor positioning algorithms. To cope with the challenge of environmental dependency in indoor positioning, a robust algorithm using radio signal identification was developed. The algorithm uses circle expansion and reduction mechanism to achieve better RSSI-Distance relationship. The distances from RSSI-Distance …


Bayesian Hetero-Elasticnet (A Gibbs Sampler Approach), Isiaka Oloyede Aug 2021

Bayesian Hetero-Elasticnet (A Gibbs Sampler Approach), Isiaka Oloyede

Tanzania Journal of Science

Combined heteroscedasticity and multicollinearity as dual non-spherical disturbances were experimented asymptotically. A Gibbs Sampler technique was used to investigate the asymptotic properties of hetero-elasticnet estimator with mean squares error (MSE) and bias as performance metrics. The seed was set to 12345;  is set at ; Xs variables were generated as follow: the design matrix was generated from the multivariate normal distribution with mean > 0 and variance .  and  are truncated with Harvey (1976) heteroscedastic error structure;  are collinear covariate with pairwise correlation between 0.6 and 0.9, the sample sizes were 25, 100 and 1000. The number of replications of the …


Weighted Statistical A-Optimal Designs For Two-Variable Poisson Regression Model With Application To Fertility Studies, Emmanuel Idowu Olamide, Femi Barnabas Adebola, Olusoga Akin Fasoranbaku Aug 2021

Weighted Statistical A-Optimal Designs For Two-Variable Poisson Regression Model With Application To Fertility Studies, Emmanuel Idowu Olamide, Femi Barnabas Adebola, Olusoga Akin Fasoranbaku

Tanzania Journal of Science

This research extends design optimization to model involving count data. A two-variable Poisson regression model was investigated for A-optimality on a constrained design space and the weights of the optimal design points were obtained. The constructed designs were verified to be A-optimal at 4-point design through the general equivalence theorem. The efficiency of the constructed optimal design was found to be 100% A-efficient. The concept of weighted optimal designs for Poisson regression model was applied to fertility studies. Approximate A-optimal design weights of educational level of women were obtained for each marriage duration period with respect to their places of …


Efficient Load Balancing Algorithm In Long Term Evolution (Lte) Heterogeneous Network Based On Dynamic Cell Range Expansion Bias, Emmanuel Bakuza, Hashimu U. Iddi, Abdi T. Abdalla Aug 2021

Efficient Load Balancing Algorithm In Long Term Evolution (Lte) Heterogeneous Network Based On Dynamic Cell Range Expansion Bias, Emmanuel Bakuza, Hashimu U. Iddi, Abdi T. Abdalla

Tanzania Journal of Science

The traditional scheme for load balancing in a homogeneous Long Term Evolution (LTE) Network where User Equipment (UEs) associate to a node with the strongest received signal strength is not practical for LTE Heterogeneous Network (LTE HetNet) due to power disparity between the nodes. Therefore, dynamic Cell Range Expansion (CRE) based load-balancing schemes were employed by several scholars to address the challenges in the LTE HetNet. However, the fairness index in achieving the desired average user throughput and UE offloading effect is relatively low. In this work, an efficient load-balancing algorithm for LTE HetNet based on dynamic Cell Range Expansion …


E-Optimal Experimental Designs For Poisson Regression Models In Two And Three Variables, Emmanuel Idowu Olamide, Olusoga Akin Fasoranbaku, Femi Barnabas Adebola Aug 2021

E-Optimal Experimental Designs For Poisson Regression Models In Two And Three Variables, Emmanuel Idowu Olamide, Olusoga Akin Fasoranbaku, Femi Barnabas Adebola

Tanzania Journal of Science

In the context of generalized linear models, most of the recent studies were on logistic regression models and many of them focussed on optimal experimental designs with concentration on D-optimality. In this research, two- and three-variable Poisson regression models were considered for E-optimization on restricted design space [0, 1]. The two-variable Poisson regression model was not optimal at 3-design points, but was found to be E-optimal at 4-design points (1, 1), (0, 0), (0, 1) and (1, 0) with equal design weights of 0.25. The three-variable Poisson regression model was E-optimal at 4-design points (0, 0, 1), (0, 1, 0), …


Elegant Iterative Methods For Solving A Nonlinear Matrix Equation X-A^* E^X A=I, Chacha S Chacha Aug 2021

Elegant Iterative Methods For Solving A Nonlinear Matrix Equation X-A^* E^X A=I, Chacha S Chacha

Tanzania Journal of Science

The nonlinear matrix equation   was solved by Gao (2016) via standard fixed point method. In this paper, three more elegant iterative methods are proposed to find the approximate solution of the nonlinear matrix equation  namely: Newton’s method; modified fixed point method and a combination of Newton’s method and fixed point method. The convergence of Newton’s method and modified fixed point method are derived. Comparative numerical experimental results indicate that the new developed algorithms have both less computational time and good convergence properties when compared to their respective standard algorithms. Keywords: Hermitian positive definite solution, nonlinear matrix equation, modified fixed point …


A Gate-Based Monte Carlo Simulation Of A Dual-Layer Pixelized Gadolinium Oxyorthosilicate (Gso) Detector Performance And Response For Micro Pet Scanner, Leonid L Nkuba, Innocent J Lugendo, Idrissa S Amour May 2021

A Gate-Based Monte Carlo Simulation Of A Dual-Layer Pixelized Gadolinium Oxyorthosilicate (Gso) Detector Performance And Response For Micro Pet Scanner, Leonid L Nkuba, Innocent J Lugendo, Idrissa S Amour

Tanzania Journal of Science

The purpose of this study was to simulate the GSO detector of a micro PET using GATE simulation platform. The performance and responses of the simulated GSO detector assembly were evaluated by comparing the simulated data to the experimental and XCOM data to validate the simulation platform and procedure. Based on NEMA NU-4 2008 protocols, the performance of GSO detector in terms of sensitivity was simulated and compared to the experimental data. Similarly, the GSO detector response to photons interaction was simulated and compared against the XCOM data for absorbed intensity ratio in the GSO detector and survived intensity ratio …


Solving The University Course Timetabling Problem Using Bat Inspired Algorithm, Ushindi Limota, Egbert Mujuni, Allen Mushi May 2021

Solving The University Course Timetabling Problem Using Bat Inspired Algorithm, Ushindi Limota, Egbert Mujuni, Allen Mushi

Tanzania Journal of Science

Many mathematical optimization problems from real-life applications are NP-hard, and hence no algorithm that solves them to optimality within a reasonable time is known. For this reason, metaheuristic methods are mostly preferred when their size is big. Many meta-heuristic methods have been proposed to solve various combinatorial optimization problems. One of the newly introduced metaheuristic methods is a bat-inspired algorithm, which is based on the echolocation behaviour of microbats. Bat algorithm (BA) and its variants have been used successfully to solve several optimization problems. However, from the No-free Lunch Theorem, it is known that there is no universal metaheuristic method …


Mathematical Analysis Of Harvested Predator-Prey System With Prey Refuge And Intraspecific Competition, Alanus Mapunda, Thadei Sagamiko May 2021

Mathematical Analysis Of Harvested Predator-Prey System With Prey Refuge And Intraspecific Competition, Alanus Mapunda, Thadei Sagamiko

Tanzania Journal of Science

In this paper, a predator-prey relationship in the presence of prey refuge was studied. The analysis of the dependence of locally stable equilibrium points on the parameters of the problem was carried out. Bifurcation and limit cycles for the model were analyzed to show the dynamical behaviour of the system. The results showed that the system is stable at a constant prey refuge m = 0.3 and prey harvesting rate H = 0.3. However, increasing m and decreasing H or vice versa, the predator-prey system remains stable. It was further observed that for a constant prey refuge m ≥ 0.78, …


Investigation Of Some Factors Associated With Utilization Of Maternal Health Care Services By Adolescent Mothers In Tanzania, Elia Magwaja, Jacqueline Minja, Majige Selemani Budeba, Rocky R.J. Akarro May 2021

Investigation Of Some Factors Associated With Utilization Of Maternal Health Care Services By Adolescent Mothers In Tanzania, Elia Magwaja, Jacqueline Minja, Majige Selemani Budeba, Rocky R.J. Akarro

Tanzania Journal of Science

This study examined some factors associated with the utilization of maternal health care servicesby adolescent mothers (15-19 years) in Tanzania in order to provide advice accordingly. The studyused cross-sectional study of adolescent mothers aged 15-19 years using Demographic HealthSurvey and Malaria indicator Survey 2015/16 data. The dependent variables were number ofantenatal care visits, the place where an adolescent mother delivered and post-natal checkup(adolescent mother’s health checking after being discharged or after a home delivery). Theindependent variables were birth order, education level of a mother, marital status of a mother,media exposure, wealth index, distance to health facility. Multiple binary logistic regression …


Application Of Optimal Control To Tuberculosis Model With Parameter Estimations: Bayesian Approach, Goodluck M Mlay, Alfred K Hugo May 2021

Application Of Optimal Control To Tuberculosis Model With Parameter Estimations: Bayesian Approach, Goodluck M Mlay, Alfred K Hugo

Tanzania Journal of Science

In this paper, one-strain tuberculosis (TB) model with two control mechanisms, education campaigns and chemoprophylaxis of TB-infected patients, was studied to determine their effects on the reduction of latent and active TB cases. In the case of analysis, boundedness and positivity of the model solutions were carried out to determine the biological feasibility of the study. Besides, the calibration of the parameters by utilizing the identifiability technique through the Markov chain Monte Carlo (MCMC) was thoroughly analysed. The optimum conditions for controlling TB were derived from the Pontryagin Maximum Principle. The numerical simulations were carried out using the forward-back sweep …


Evaluation Of Scatter Suppression Algorithm For X-Ray Exposure Of Soft Tissue Equivalent Phantoms Over Nominal Energy Range Using Fluka Code, Samson O Omondi, Innocent J Lugendo, Ramadhan R Kazema, Robert Kinyua May 2021

Evaluation Of Scatter Suppression Algorithm For X-Ray Exposure Of Soft Tissue Equivalent Phantoms Over Nominal Energy Range Using Fluka Code, Samson O Omondi, Innocent J Lugendo, Ramadhan R Kazema, Robert Kinyua

Tanzania Journal of Science

Soft tissue imaging is heavily impaired by streaks and cupping effects associated with X-ray scatter. Quality of images from projection imaging may be improved by the use of enhanced anti-scatter grids’ designs with potency to reject significant scatter. However, optimization of grid characteristics requires investigation to improve diagnostic image quality. Transmitted scatter spatially distributed degrades images engendering need for effective scatter correction protocols. This study investigated the pre-scan scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range. Adipose tissue and polymethyl methacrylate phantoms of cross-sectional area (30 x 30) cm2 and of varying thickness …


Count Time Series Models For Road Traffic Accidents In Tanzania Mainland, Amina S Msengwa, Florence D Ngari May 2021

Count Time Series Models For Road Traffic Accidents In Tanzania Mainland, Amina S Msengwa, Florence D Ngari

Tanzania Journal of Science

A pairwise analysis was conducted to assess the trends and factors associated with road traffic accidents in Tanzania. The Poisson and Negative Binomial Autoregressive Models were used to extend log linear functions by accounting time-varying components. A total of 85,514 road traffic accidents in Tanzania mainland that occurred from 2012 to 2017 were extracted from Tanzania Police Office records. Eleven factors were grouped into a human, vehicle, physical/environmental and pedestrian-related factors. The Likelihood ratio test, Akaike Information Criterion, Bayesian Information Criterion and residual ACF plots were used to evaluate the performance of the models in Dar es Salaam and other …


Spatial Distribution Patterns Of The Populations Of Two Subterranean Termites (Blattodea: Termitidae) In Eucalyptus (Myrtales: Myrtaceae) Plantations, Olaniyi T Alamu, Francis K Ewete, Ayangbade E Ayandokun, John A Ete May 2021

Spatial Distribution Patterns Of The Populations Of Two Subterranean Termites (Blattodea: Termitidae) In Eucalyptus (Myrtales: Myrtaceae) Plantations, Olaniyi T Alamu, Francis K Ewete, Ayangbade E Ayandokun, John A Ete

Tanzania Journal of Science

The study was conducted in Afaka, Northern Guinea Savanna of Nigeria to determine the spatial distribution patterns of the populations of Ancistrotermes sp. and Microtermes sp. in Eucalyptus camaldulensis Dehnh, Eucalyptus citriodora Hook, Eucalyptus cloeziana F. and Eucalyptus tereticornis Muell plantations. Spatial distributions patterns of the two termite species populations were determined using indices such as ratios of population variance to mean, Lloyd’s index, Green coefficient, Taylor power and Iwao’s regression models. The values of variance to mean ratios, Lloyd’s index and Green coefficient showed that the populations of both termite species had aggregated distribution pattern in all the Eucalyptus …


Influence Of Covid-19 On The Psychological Wellbeing Of Tertiary Institution Students In Nigeria, Seun Akorede, Ayodotun Ajayi, Atanda Toyin, Gilbert Uwadia Feb 2021

Influence Of Covid-19 On The Psychological Wellbeing Of Tertiary Institution Students In Nigeria, Seun Akorede, Ayodotun Ajayi, Atanda Toyin, Gilbert Uwadia

Tanzania Journal of Science

The outbreak of COVID-19 has led to a global lockdown, pending the time medical researchers find a vaccine for the coronavirus. This study examined if loneliness, depression and stress are influences of COVID-19 on the psychological wellbeing of tertiary institutions students in Nigeria. A descriptive research design of survey type was employed for this study. The population comprised all students of tertiary institutions in Nigeria totaling about 4,406,000. One hundred and thirty-seven (137) respondents were sampled for the study. A validated researcher developed questionnaire tested for reliability was used for the study. The data collected were analyzed using descriptive statistics. …


Hiv/Aids Transmission Dynamics: Modelling The Roles Of Long Distance Truck Drivers, Nyimvua Mbare Feb 2021

Hiv/Aids Transmission Dynamics: Modelling The Roles Of Long Distance Truck Drivers, Nyimvua Mbare

Tanzania Journal of Science

A mathematical model to investigate the roles of long distance truck drivers on HIV transmission dynamics was formulated and analyzed to establish the existence of disease free and endemic equilibrium points. The results show that, the disease free equilibrium point is asymptotically stable when the basic reproduction number is less than unity and unstable otherwise. Furthermore, comprehensive analyses on the two steady states (infection free and endemic) have shown that they are both globally and asymptotically stable. Sensitivity analysis is performed on the reproduction number in order to establish the relative importance of parameters, and it shows that the truck …