ghanaopendata/ghanaian-research-english huggingface dataset:
Modeling of Pension Fund Using Garch: Case Study of SSNIT

The introduction of the three-tier contribution scheme under the new pensions Act has brought great reforms in the pensions industry. Currently a total of 18.5% of the contributors basicsalary is deducted for pensions and only 11.0% goes to SSNIT , 2.5% goes to the management of the National Health Insurance Scheme and the remaining 5.0% goes to the second-tier The challenging aspect of the new Pension Act is that , although the contribution level of SSNIT is reduced ,SSNIT is asked to provide monthly pensions for at least fifteen years (additional three years) so far as a contributor lives and also provide forms of invalidity. In view of this, the researcher used the GARCH model in fitting a model for the fund size and predicted the funding level of the Trust, The sustainability ratio of the fund which determines how much sustainable the fund was within this period was also examined The predicted values showed an upwards trend in the fund size and an increase in the sustainability ratio. It was also observed that one major factor that affected the funding level of the trust was indebtedness to the Controller and Accountant Generals Department. It was the institution with the highest indebtedness percentage. The study recommended much lucrative investment opportunities for the Trust to look at, to increase its sustainability level and also measures to put in place to increase its outflow especially its expenses on operations and administration

Source: KNUST
Modeling the determinants of under-five mortality using logit regression

Child mortality, also known as under-five mortality refers to the death of infants and children under age of five. The objectives of this thesis are to identify the significant determinants of under-five mortality, set up a logit model and use it to predict under-five mortality in the Tano South district of Ghana. The district was divided into four zones and the target populations were identified using the purposive sampling. A total sample size of 200 mothers or caregivers was used, of which 50 were selected randomly from each zone. Binary logit regression was the main statistical tool for the analysis of data. The results revealed that higher parity, in particular grandmultigravidae parity has adverse significant impact on under-five mortality. Among the diseases, both anaemia and malaria showed adverse significant impact on under-five mortality. However, while there are factors that adversely impact on under-five mortality, others such as the use of treated bed net, child vaccine, not exclusive and exclusive breast feeding reduce its likelihood. It is therefore recommended that more education and sensitization on precautionary measures and good health should be given to mothers, especially mothers of grandmultigravidae parity. Additionally, education on the use treated bed-nets in the homes of mothers should be intensified.

Source: KNUST
MODELING THE INFECTION DYNAMICS OF ONCHOCERCIASIS AND ITS TREATMENT

Onchocerciasis is one of the neglected tropical diseases caused by Onchocerca volvulus. Ivermectin is known to be effective in the treatment of onchocerciasis because it suppresses the production of microfilariae by the adult female worms for a few months following treatment thus reducing transmission. In this study, a deterministic model is developed to assess the effect of mass treatment of onchocerciasis with ivermectin. The basic reproduction number, R0, of the model system is determined and it is observed that the model exhibits backward bifurcation for some parameters implying the existence of multiple endemic equilibria when R0 < 1. The existence of multiple equilibria emphasizes the fact that R0 < 1 is not sufficient to eradicate the disease and the need is to lower R0 much below one to make the disease-free equilibrium globally stable. Numerical simulations are done and conclusions drawn with respect to the known treatment protocols in endemic areas. The study results suggest that the mass treatment of the disease with ivermectin should cover a higher proportion of the population to control the disease and eventually eliminate it from the population.

Source: KNUST
Modeling the occurrence and incidence of malaria cases: a case study at Obuasi Government Hospital

Malaria has always been a major a major health problem and therefore timely and accurate information about its occurrence and incidence cannot be underestimated. The main objectives of this research is to model the occurrence of malaria cases given the age, gender and time in quarters ; to model the incidence of severe malaria cases given age , gender and time in years and lastly to validate the two models using negative binomial regression model. Poisson and negative binomial regression models were used in fitting the data obtained from Obuasi Government Hospital data based dated 2007 to 2010. Based on the results, the negative binomial regression model fitted the data better than the Poisson regression model. Both models indicated that malaria is independent of gender. With respect to time, more cases were recorded in quarters4 (October-December) in the first model and the incidence of severe malaria cases also increased with time in the second model. The prevalence of malaria and severe malaria cases were found to be prevalent among children with less than 1 year old, and those under 5 and 70+years old. More cases were recorded for those found 20-34 year groups with reference to occurrence of malaria and incidence of severe malaria cases. Consequently, we draw a conclusion that despite the various interventions such as the Internal Residual Mass Spraying (I R M S) exercise by the Malaria Control Programme of AngloGold Ashanti introduced in 2006 and other social programmes aimed at reducing the menace of malaria, it’s still remains high particularly among children under 5 years and those found between 20-34 age groups.

Source: KNUST
Modeling the Kinetics of Potassium Diffusion in Estima Potato under Different Leaching Conditions

The diffusion of potassium in potato (Solanum tuberosum) at different leaching conditions was investigated. Two modes of pretreatment of potato samples (cubes and spheres) by preheating to 80° C and leaching at temperatures of 20-80° C were performed using a temperature- and agitation-controlled batch extractor. A Fickian model incorporating the effective diffusion coefficient (Deff), partition coefficient (K) between the solute concentration in the potato and medium, and mass transfer coefficient (kl) was developed to simulate and predict the fraction of potassium leached from the potato at any temperature. Results showed significant reduction in activation energies from 92 to 25.02 kJ/mol for cubes and from 75.02 to 13.40 kJ/mol for spheres culminating in higher extraction rates when samples were preheated to 80° C. The Deff , K, and kl values obtained were in the range of 0:02 − 7:33 × 10−9 m2/s, 0:63 − 8:00 × 10−2, and 0:01333:00 × 10−4 m/s, respectively. The kinetic parameters showed a change in slope or discontinuity in the gelatinization temperature range as a function of temperature, an indication of a change in the diffusional matrix. The optimum operating conditions were 80° C preheating and leaching at temperatures up to 50° C. The proposed mathematical model offered a satisfactory description of both dynamic and equilibrium mass transfers of potassium by adequately predicting the fraction of potassium from potato cubes and spheres. The present findings could be useful in the pretreatment of potato for renal patients.

Source: KNUST
Modeling the E ects of Nutritional Withdrawal on CD4 Cell Count Among HIV/AIDS Patients Using Generalized Estimating Equations (GEE).

Malnutrition is one of the major complications of HIV/AIDS (Lui et al., 2011). Nutritional intervention programs for People Living with HIV/AIDS (PLWHA) were withdrawn in Kumasi. The aim of this study is to examine the withdrawal e ects of the nutritional intervention on CD4+ cell counts and model the CD4+ cell counts before, during and after the initiation of the intervention, given BMI, HB levels and other characteristics of PLWHA. The study was carried out using data from a retrospective cohort study of 501 PLWHA who started ART from 2007 to 2011. Generalized Estimation Equations (GEE) was used to model the CD4+ cell counts before, during and after the initiation of the intervention, given BMI, HB levels and other characteristics of PLWHA. Age, the linear interaction between HB and time, the linear interaction between BMI and time, Group 1 (No Intervention) and Group 2 (Intervention) were all statistically signi cant predictors of CD4+ cell count at the level of 0.05. The nutritional interven- tion positively a ected the health outcomes of PLWHA during the nutritional intervention. After the intervention however, there was a signi cant reduction in the average CD4 cell count of respondents. BMI predicts a positive gain in CD4+ cell count of respondent and there was a positive correlation between the blood haemoglobin levels of the HIV/AIDS patients and their CD4 cell counts. There was an inverse relationship between age and CD4 cell counts of HIV/AIDS patients; which is consistent with other works.

Source: KNUST
Modeling the spread of tuberculosis in Central Region using the susceptible-exposed-infected-susceptible (SEIS) mathematical model

Tuberculosis (TB) is a growing problem worldwide, with an estimated one-third of the world’s population currently infected. In this thesis we modify the non-constant population SEIS model developed by Castillo-Chavez to a constant population model to predict the spread of tuberculosis in the Central Region of Ghana using data from the Central regional Health Directorate, Cape Coast. We discuss the mathematics behind the model and various tools for judging effectiveness of policies and control methods. The model has two equilibrium states namely, the disease – free and the endemic equilibrium points. The stability of each equilibrium point is discussed and the endemic equilibrium has been found to be stable while that of the disease-free was unstable. The basic reproduction number (R_o) was estimated to be 2. The disease was found to persist with R_o >1 whenever the transmission rate was increased or the recovery rate reduced but turned to die out with R_o <1, whenever the transmission rate was reduced or the recovery rate increased. The results of our sensitivity analysis showed that the most sensitive parameter that controls the spread of tuberculosis in Central Region is the initial infection rate of the susceptible, σ. Decreasing the value of σ at the same rate as the other parameter values completely decreases the proportions of both the infective and the exposed more effectively than any parameter value. From the analysis and discussions of the model, SEIS epidemiological model is a good model to study the spread of tuberculosis in Ghana.

Source: KNUST
Modeling The Surrender Of Life Insurance Policies In Ghana: A Case Study Of An Insurance Company

The life insurance industry is a very essential part of the financial structure of every economy. This industry provides a means through which the insured to transfer their risks of death or any other specified event to the insurer. The industry is however faced with the risk of policy surrenders which poses a long term threat to the industry. The study seeks to establish the extent to which heterogeneity among policyholders affects the rate of policy surrenders. The study used surrender data covering the period 2011 to 2017. Data analysis was done by employing non-parametric survival analysis tools and Cox PH models. Log rank tests were carried out on each categorical variable to ascertain whether there is a significant difference between the surrender rates of these variables. The outcome of the log rank test revealed that, there exists a significant difference in surrender rates of males and females, and also, endowment and universal policies respectively. Occupation showed no significant difference among its two classes, formal and informal. From the results of the Cox PH, it was observed that, gender, age and policy type were significant in having an effect on life insurance policy surrender rates. A Schoenfeld residual test showed that, the chosen model assumes proportional hazards. The study recommends to the management of the life insurance company to devise strategies to retain the males and also to target females, and increase marketing of universal policies. The study also recommends that, further research be carried out and extended to cover more life insurance companies with more data.

Source: KNUST
Modeling the role of humic substances in the distribution of trace metals in selected ecosystems in Ghana

The complexity of semi-natural ecosystems in terms of the composition and chemical properties of the solid and solution phases has cause researchers to develop intelligent and innovative ways of modeling and using the models to describe the chemistry of metal distribution in natural environments. But a comprehensive model that adequately describes the role humic substances play in trace metal distribution in semi-natural ecosystems is absent. The colloidal properties and aggregation properties at cloud point have not been effectively correlated with its cation binding properties. In view of these the role of humic substances in trace metal distribution at the mining communities at Talensi-Nabdam District of Upper East Region of Ghana were modeled in this study. Development of the models was based on the novel idea that there is a relationship between the fraction of metal associated with humic matter, intrinsic properties of the humic matter and metal partition constant. A quantitative account of the role of humic substance in metal distribution was studied using component factor analysis approach to model the speciation and distribution phenomena of trace metals at the selected ecosystem for the study. The properties of humic substance and the interactions of trace metals were correlated and used to develop mathematical models for the description of the role of humic substance in metal partition. The conceptual and mathematical models were proved to have the potential to explain the humic-impacted-partition of trace metals when they were fitted to data obtained from field and simulation experiments. The distribution model explained 97.99% of the factors which influence trace metal distribution in the terrestrial environment out of which humic substances accounts for more than 30 % of all the factors. The speciation model also showed that humic substances account for VI 13.06% of the variables which determine trace metal speciation at the ecosystem studied. It was concluded that humic substances play a significant role in trace metal distribution in terrestrial environment. The mathematical models gave good correlations and R2 values when fitted to data from simulation experiments. The models described the trace metal partition well in terms of humic acid (HA) complexation and partition. The overall impression of the models is that HA influences Cu distribution in soil solution system to an extent determined by the relative proportion of other cations which compete with the metal for both the humic acid and the soil mineral. The models also indicated that modification of the solid phase by HA introduces two major heterogeneous binding sites in the solid phase (i.e., the organic and inorganic binding sites) and that changes in the relative moles of the site types are determined by the cation binding and hydrophobic properties of HA. The models indicated that the properties of humic substance which makes it capable of influencing trace metal distribution are hydrophobicity, detergent properties and metal complexing ability.

Source: KNUST
Modeling the spatial distribution of Global Solar Radiation (GSR) over Ghana using the Angström-Prescott ˚ sunshine duration model

Solar radiation is an important geological and meteorological parameter. In most developing countries, data is readily unavailable owing to lack of instrumentation and skilled personnel. In this study, Global solar radiation (GSR) over Ghana has been quantified using the Angström–Prescott ˚ sunshine model with sunshine duration data from 22 synoptic stations distributed across the country’s ecological zones. The simulated data was gridded at 10 km by 10 km, establishing the spatial distribution of solar radiation over the country. Comparison with satellite data showed good results with root mean square error (RMSE) values of 1–5 MJm−2day−1 and correlation coefficient of 60 - 66%. Meanwhile, the estimated total GSR over the country was found to be 412.82 MJm−2day−1. The savanna zone had the maximum estimated total monthly mean GSR for the year, with the highest value of 20.76 MJm−2day−1 in Navrongo. The forest zone had the minimum estimated total annual mean GSR, with the lowest radiation level in Oda (17.11 MJm−2day−1). A maximum and minimum mean clearness index of 0.59 and 0.48 respectively are estimated, implying that about 53% of solar radiation at the top of the atmosphere reaches the study area after attenuation. The satellite data has a total monthly mean horizontal Global Solar irradiance of 366.62 MJm−2day−1. The study shows that the region is a potential field to harness and optimize solar energy for the operation of photovoltaic systems and solar collectors for industrial and domestic applications.

Source: KNUST
Modeling The Transshipment Problem Of A Company (Case Study: Dupaul Wood Treatment(Gh) Ltd)

The transportation problem is a special class of the Linear Programming problem which seeks the determination of a shipping plan for transportion a single commodity from a number of sources to a number of destinations at a possible minimum transportation cost whilst satisfying the demands at the respective destinations. Unlike transportation problem which considers the units to be sent from the various sources, the demands at various destinations and unit transportation cost per product, Transshipment problem which is an expansion of the transportation problem considers units to be sent from the various sources, the demands at various destinations, unit transportation cost per product, intermediate nodes which are also referred to as transshipment nodes. My main objective is to model Dupaul Wood Treatement Limited transportation network as a transshipment problem and also minimize the cost in transportating their product. I will convert the Transshipment problem to an equivalent Transportation tableau and use the Transportation algorithm to solve it. QM for windows (Software for Quantitative Method, Operations Research and Management Science) will be used to analyze the data. The results of our analysis revealed that a signi cant savings of GH¢477.94

Source: KNUST
Modeling Vehicle Traffic Flow between Traffic Light Nodes with Partial Differential Equations

Vehicle traffic flow has become a challenge in this modern world of automobiles due to constantly accelerated influx of vehicles on the road network. The challenge of traffic flow has motivated many researchers to model traffic flow at both the macroscopic and microscopic levels. In order to ensure free flow of vehicles in the cities, road engineers have developed and implemented traffic lights to regulate the inflow and outflow of vehicles at the major intersections of road. However, the traffic lights have become one the major causes of traffic jams in the cities since they force the vehicles to stop causing a discontinuity of flow. This study seeks to model the continuous and the discontinuous behaviour of vehicles by the parameters: flow, density and velocity between two given traffic light nodes in Kumasi, Ghana with the use of partial differential Equations (PDEs) based on Lighthill, Whitham and Richard (LWR) model. Primary data was obtained from the study zone, a 100m road segment in Kumasi, during the peak hour in the morning .The flow was regressed on the density and the result indicated a quadratic dependence between flow and density confirming the fundamental relation of Greenshield. With prescribed initial conditions, the first order nonlinear homogeneous and nonlinear inhomogeneous PDE’s models were solved using the method of characteristics.

Source: KNUST
Modeling the trnsportation of solid waste from the transfer stations to the disposal sites in Tamale Metropolis

Solid waste management framework preoccupies itself with the collection, treatment and disposal of wastes within the boundaries of districts, municipalities and metropolis. Increasing environmental concerns and the emphasis on materials and energy are overwhelmingly changing the modus operandi of solid waste management as a whole and its transportation in particular. This study targeted Tamale metropolis so that a comprehensive and workable as well as efficient approach to solid waste transportation could be obtained through modeling for effective system of solid waste management. For management purposes, the Metropolis has been divided into two with one section managed by the Waste Management Department (WMD) and the other by ZoomLion (ZL). It was estimated that 240-260 tons of waste was generated a day in the management area of the WMD out of which about 70% was hauled daily. This left a backlog of 30% uncollected every day. Within the management area of ZL, about 110-115 tons of waste was generated a day and about 46% was hauled daily. This left a backlog of about 54%. This deficit has led to littering, heaping of waste and overflowing of skips. This avoidable situation could lead to contagious diseases such as typhoid, malaria, cholera and many more. Data for this thesis were obtained from primary and secondary sources. These were used to construct models for minimizing the cost of waste transportation to the available disposal sites. Vogel’s Approximation Method (VAM) and Modified Distribution (MODI) method were used to determine the initial feasible solution and optimal solution respectively. The model determined the optimal routes for waste transportation in each of the operational areas. Using the model, WMD would clear 175 tons of solid waste daily using GH¢171.45 instead of GH¢ 383.94; and ZL Ghana Ltd, Tamale would clear 51tons using GH¢197.80 instead of GH¢977.03 if no condition has changed. Working outside the models may increase the expenditure.

Source: KNUST
Modeling Transshipment Problem in a Manufacturing Industry: Case Study: Coca-Cola Bottling Company, Kumasi

In this thesis we focus on a decision model for a real world problem. The problem reveal itself as a transshipment problem where the Coca-Cola Bottling Company, Kumasi, transports its products from source to destinations through intermediate points as a system consisting of multiple retail locations with transshipment operations among the retailers. The study address the problem as a transportation problem and seeks find an efficient way to minimize the total transportation cost using the Dual Matrix Approach. Manual computations were also used to obtain the optimal solution.

Source: KNUST