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Deep Reinforcement Learning based Handover Management for Millimeter Wave Communication
Get PDFThis research article published by the International Journal of Advanced Computer Science and Applications, Vol. 12, No. 2, 2021The Millimeter Wave (mm-wave) band has a broad-spectrum capable of transmitting multi-gigabit per-second date-rate. However, the band suffers seriously from obstruction and high path loss, resulting in line-of-sight (LOS) and non-line-of-sight (NLOS) transmissions. All these lead to significant fluctu-ation in the signal received at the user end. Signal fluctuations present an unprecedented challenge in implementing the fifth gen-eration (5G) use-cases of the mm-wave spectrum. It also increases the user’s chances of changing the serving Base Station (BS) in the process, commonly known as Handover (HO). HO events become frequent for an ultra-dense dense network scenario, and HO management becomes increasingly challenging as the number of BS increases. HOs reduce network throughput, and hence the significance of mm-wave to 5G wireless system is diminished without adequate HO control. In this study, we propose a model for HO control based on the offline reinforcement learning (RL) algorithm that autonomously and smartly optimizes HO decisions taking into account prolonged user connectivity and throughput. We conclude by presenting the proposed model’s performance and comparing it with the state-of-art model, rate based HO scheme. The results reveal that the proposed model decreases excess HO by 70%, thus achieving a higher throughput relative to the rates based HO scheme
Variations in nutrient composition of oyster nuts (Telfairia pedata) across different agro-climatic conditions
Get PDFThis research article published by Taylor & Francis Online, 2021In sub-Saharan Africa, nutrient deficiency remains a challenge. The challenge is partly due to the underutilization of available local nutrient sources and failure to optimize nutrients based on agro-climatic conditions. This study investigated the nutrient composition and variations in the underutilized oyster nuts (Telfairia pedata) from different sites and elevation levels encompassing different agro-climatic conditions. Fats were the most abundant contents of the nuts with 68%, followed by 25% protein, 5% carbohydrates, and 2% ash. Fatty acid contents were dominated by linoleic acid (47%), while magnesium was 150 mg/100 g, the most abundant mineral element. Protein and fat contents increased significantly with declining elevations, while sites did not show any significant effects, except for oleic acids. These were higher in Tanga compared to Kilimanjaro and Arusha sites. In contrast, linoleic acids and minerals such as magnesium (Mg) and phosphorus (P) decreased significantly in low elevations. Other nutrients such as carbohydrates, potassium (K), calcium (Ca), iron (Fe), palmitic acid, and stearic acid were not significantly affected by site nor elevations. Our results highlight that, particularly in lower elevations associated with high temperature and high precipitation, oyster nuts’ quality is optimized and can contribute to reducing micronutrient deficiency and improve local communities’ nutritional status in sub-Saharan Africa
Dog ownership practices and responsibilities for children's health in terms of rabies control and prevention in rural communities in Tanzania.
Get PDFThis research article published by PLOS ONE, 2021Interventions tackling zoonoses require an understanding of healthcare patterns related to both human and animal hosts. The control of dog-mediated rabies is a good example. Despite the availability of effective control measures, 59,000 people die of rabies every year worldwide. In Tanzania, children are most at risk, contributing ~40% of deaths. Mass dog vaccination can break the transmission cycle, but reaching the recommended 70% coverage is challenging where vaccination depends on willingness to vaccinate dogs. Awareness campaigns in communities often target children, but do not consider other key individuals in the prevention chain. Understanding factors related to dog ownership and household-level responsibility for dog vaccination and child health is critical to the design of vaccination strategies. We investigated who makes household decisions about dogs and on health care for children in rural Tanzania. In the Kilosa district, in-depth interviews with 10 key informants were conducted to inform analysis of data from a household survey of 799 households and a survey on Knowledge Attitudes and Practices of 417 households. The in-depth interviews were analysed using framework analysis. Descriptive analysis showed responsibilities for household decisions on dogs' and children's health. Multivariate analysis determined factors associated with the probability of dogs being owned and the number of dogs owned, as well as factors associated with the responsibility for child health. Dog ownership varied considerably between villages and even households. The number of dogs per household was associated with the size of a household and the presence of livestock. Children are not directly involved in the decision to vaccinate a dog, which is largely made by the father, while responsibility for seeking health care if a child is bitten lies with the mother. These novel results are relevant for the design and implementation of rabies interventions. Specifically, awareness campaigns should focus on decision-makers in households to improve rabies prevention practices and on the understanding of processes critical to the control of zoonoses more broadly
The influence of agri-entrepreneurship courses studied on youth farm entrepreneurial intention: Evidence from Folk Development Colleges in Tanzania
Get PDFThis research article published by African Online Scientific Information Systems, 2021Background: Youth engagement in agriculture in developing countries is of paramount importance since much of their livelihoods depend on this sector.
Aim: This article therefore aims at assessing the influence of studying agri-entrepreneurship courses on youth farm entrepreneurial intention.
Setting: Three of the 55 Folk Development Colleges (FDCs) in Tanzania.
Methods: A cross-sectional design was employed and 300 respondents were randomly selected from three FDCs offering agricultural programmes. Both qualitative and quantitative data were collected and analysed by using descriptive and inferential statistics in which frequencies, percentages, mean, standard deviation and Somers’s D Model were employed.
Results: The results show that there is a significant relationship between agri-entrepreneurship knowledge and skills acquired and youth entrepreneurial intentions towards farming.
Conclusion: The FDCs’ agri-entrepreneurial training provides knowledge and skills which influence youth farm entrepreneurial intention. However, the strength of this influence ranges from weak to moderate depending on various factors. Regular reviews of curricula to enhance the beliefs that develop a view of farm entrepreneurship as a paying business is recommended. The analysis and implication of this finding has been further explained
Performance of inclined plates settler integrated with constructed wetland for high turbidity water treatment
Get PDFThis research article published by IWA Publishing, 2021The purpose of this study was to investigate and demonstrate cost-effective treatment technologies for high
turbid waters, used for domestic purposes in rural areas of Tanzania where conventional community water
treatment techniques are not available. Pilot scale inclined plates setter integrated with constructed wetland
(IPS-CW) system was investigated on earth dam water with turbidities ranging from 186 to 4,011 NTU. The IPS
was used as a physical pretreatment system preceding the CW, meant for the removal of organic matter, nutrients, and pathogens. Major focus of the IPS-CW system was on turbidity and faecal coliform (FC) removal and at
5 L/min flow rate mean maximum removal efficiency of 95.9% and 94.3% were achieved, respectively. Total
suspended solids, nitrate (NO3
), ammonium, biological oxygen demand (BOD5) and phosphate removal were
studied and removal efficiencies of 97.4%, 91.7%, 71.3%, 91.7% and 49.8% were obtained at 5 L/min flow
rate, respectively. Although the use of these combinations of technologies in improving drinking water quality
is uncommon, results demonstrated that NO3
and BOD5 met WHO and TBS drinking water standards of 50 mg/l
and 6 mg/L respectively. Due to low production cost and simplicity in operation the system is relevant for
application in rural communities
Optimisation of fermentation processes of local cereal-based beverages to produce improved cereal based probiotic beverages.
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy in Life Sciences of the Nelson Mandela African Institution of
Science and TechnologyFermented cereal-based probiotic beverages are rare and have rarely been produced in
Tanzania. Though the beverages are novel, the potentiality of such beverages has for some
decades been exhibited through local fermented cereal-based beverages. In recent years there
has been a paradigm shift towards non-diary probiotic products because of the negative health
effects milk and dairy products have on the multitude of people around the world. A
quantitative study employing purposeful sampling was carried out in three regions of Mbeya,
Morogoro and Kilimanjaro whereby in each of the regions; quadruplicate samples of either of
the traditional cereal-based beverages locally known as Kindi, Kimpumu, Togwa or Mbege
were collected from a target village and stored at 4 °C in the laboratory. Identification of
probiotic microbes in the local beverages was done and probiotic Kindi, Kimpumu, Mbege and
Togwa were developed using pure cultures of the identified probiotic bacteria. Probiotic
cultures used were Lactobacillus brevis for Togwa, Lactobacillus plantarum for Kimpumu and
Mbege and Pediococcus pentosaceus for Kindi. After 24-48 h of controlled fermentation at 37
°C; results showed that the prepared cereal-based beverages were probiotic with mean viable
cell counts of 1 x 1011 cfu/mL and mean pH 4.77. During storage the probiotic cereal beverages
remained stable for five days at 25 °C and 28 days (4 weeks) at 4 °C with viable cell count of
2.0 x 1011 cfu/mL and pH 3.83 at 25 °C and viable cell count of 2.0 x 1011 cfu/mL and pH 4.08
at 4 °C, respectively. There was no growth of pathogens in the beverages. The four cereal based probiotic beverages were equally accepted by consumers through a sensorial evaluation.
This study shows that controlled fermentation of cereals using carefully selected probiotic
bacteria results in probiotic cereal based-beverages with good quality attributes and safety and
further advance the knowledge on fermented cereal substrates as nutrient-rich and promising
delivery vehicles for probiotics by sustaining the growth of a large population of lactic acid
bacteria
Clay-based ceramic materials for water de-fluoridation
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Materials Science and Engineering of the Nelson Mandela African Institution
of Science and TechnologyLong-term consumption of water with fluoride concentration above the WHO recommended
limit of 1.5 mg/g may cause fluorosis. Low-income communities living in fluoride endemic
regions are more affected as they cannot afford well-established water de-fluoridation
technologies. Currently, clay ceramic materials impregnated with silver colloids have been
used to disinfect water disregarding the removal of fluoride. This work investigated improving
the de-fluoridation capacity of clay ceramic materials with in-situ generated Ca/Mg phosphate
system using locally available carbonate rocks as a source of Ca/Mg. To achieve this, clayCa/Mg
phosphate
system
composite
ceramic
materials
were
synthesized
from
varied
ratios
of
clay
(K)
to
carbonate
rock
materials
(R)
(K:R
=
0:100,
90∶10,
85∶15,
75∶25
and
100:0),
sintered
at various temperatures between 500 and 900 . The materials were characterized using
XRF, FTIR, AAS, CHNS-O analyzer and X-ray PDF analysis. The three types of carbonate
rock materials investigated were identified to be; high-calcium limestone, magnesium-deficient
dolomite and near-stoichiometric dolomite. The magnesium-deficient dolomite gave rise to a
Ca/Mg phosphate system that exhibited superior de-fluoridation performance. The material
improved in de-fluoridation performance with increase sintering temperature from 500 to
700 , possibly due to an increase in the more soluble magnesium-substituted tri-calcium
phosphate (β-Mg
x
Ca
3-x
PO
4
), CaO and MgO (PDF and FTIR). This work has shown that the
de-fluorination performance of clay ceramic materials can be improved with a phosphate
system synthesized/formed in-situ using carbonate rocks as Ca/Mg source. The method of
improving the de-fluoridation performance of clay ceramic materials introduced in this present
study has potential applications in the fabrication of water filters with fluoride removal ability
Image - based poultry disease detection using deep convolutional neural network
Get PDFA Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master’s in Information and Communication Science and Engineering of the Nelson
Mandela African Institution of Science and TechnologyThe poultry sector in the country is highly affected by diseases including Coccidiosis,
Salmonella and Newcastle that have a significant impact on production. Lack of reliable
information and proper methods of farming has led to the spread of the diseases as the majority
of farmers practice traditional farming, hence lack a systematic way to detect and diagnose the
disorders. Poultry farmers rely on experts to diagnose and detect the diseases; access to the
experts is also a challenge due to the limited number of extension officers. With the available
tools from artificial intelligence and machine learning, there is a potential to semi-automate the
diagnostics process for the most common diseases in chickens. This study proposes a solution
for predicting diseases in chickens using faecal images and deep Convolutional Neural
Networks (CNN). Additionally, the work leverages the use of pre-trained models and develop
the solution for the same problem. Based on the comparison, it is indicated that the model
developed from the XceptionNet deep learning framework outperforms other models for all
the metrics used. The experimental results indicate the accuracy of transfer learning at 94%
using pre-training over the other models from fully training on the same dataset. The results
show that the pre-trained XceptionNet framework (94%) has the best overall performance and
highest prediction accuracy, and can be suitable for chicken disease detection application. The
findings show that the proposed model is ideal for poultry diseases detection method
Assessment of fluoride bioaccumulation in catfish grown in fluoride rich waters
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Environmental Sciences and Engineering of the Nelson Mandela African
Institution of Science and Technology, TanzaniaFluoride bioaccumulation in fish poses a significant impact to their growth performance,
survival and consequently to the upper trophic levels. Few studies have reported the impact of
high fluoride concentration and their accumulation to catfish in African settings. A 60-days
African catfish (Claris gariepinus) cultivation was conducted at Ngarenanyuki ward and at the
Nelson Mandela African Institution of Science and Technology (NM-AIST) laboratory in
Arusha, Tanzania, to determine fluoride bioaccumulation and its effect on growth and survival
of the catfish. The juvenile catfishes were exposed to water containing 36 mg Fˉ/L in a fishpond
and synthetic water containing fluoride concentrations (NaF) of 5, 15, 36 and 45 mg/L in the
aquaria set at NM-AIST laboratory. Fish growth and survival was determined and the fluoride
concentrations in fish tissues were analysed by ion selective electrode. At the end of the
experiment, fish survival rate was greater than 90% in fluoride levels of 5, 15, 36 mg/L
compared to 65.8% in 45 mg/L aquaria treatment. Also, significant fluoride bioaccumulation
was observed in fish bones (222.00 mg/kg, dry weight) followed by gills (177.4 mg/kg), skin (9
mg/kg) and low amount in fillets (1.467 mg/kg). In all these tissues, fluoride bioaccumulation
significantly rose with increase in fluoride levels in the water and exposure time (p< 0.001).
From this experiment, it is concluded that high fluoride occurrence in surface water led to
increased bioaccumulation in the African catfish and correlates with exposure time. Therefore,
to grow catfish in water containing more than 45 mg/L requires a deflouridation process to take
place
Performance investigation of the slaughterhouse wastewater treatment facility: a case of Mwanza city slaughterhouse, Tanzania
Get PDFA Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of
Master’s in Hydrology and Water Resources Engineering of the Nelson Mandela African
Institution of Science and TechnologyThe present study engaged onsite operations and laboratory analysis for Mwanza City
Slaughterhouse (MCS) wastewater to improve the efficiency of wastewater treatment of a
newly installed facility. The MCS wastewater treatment facility integrated with various unitsbiodigester
(Batch Stirred Tank Bio-reactor), aeration unit, retention, clarifier, and a
constructed wetland. During the initial runs, the MCS facility removed 87.5%, 92.2%, 43%,
and 65.4% of effluent biochemical oxygen demand (BOD
5
), chemical oxygen demand
(COD), ammonium, and nitrate, respectively. Also, the parameters including pH, temperature,
dissolved oxygen (DO) were used to control the system operations. After conducting effective
plant operations for five months, the removal efficiencies of BOD
5
, COD, ammonium, and
nitrate improved to 97.4%, 98.3%, 97.4%, and 97.6%. In the present study, the unit-by-unit
performance values achieved as a result of alterations of the facility‟s running conditions
presented. The MCS wastewater treatment facility found to be energy-positive, as it produced
an average of 158.2 m
3
biogas per day. This amount of biogas, if converted to electricity,
would be sufficient to run the facility operations. Generally, the MCS wastewater treatment
facility attained the best performance as per design, achieving the effluent levels
recommended by the Tanzania Standards (TZS). Also, the MCS treatment facility takes care
of the environment and human health because of effluents released to the surrounding area are
now within recommended standards