4. Electronic Theses and Dissertations (ETDs) - Faculties submissions

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A Data Science Framework for Mineral Resource Exploration and Estimation Using Remote Sensing and Machine Learning
(University of the Witwatersrand, Johannesburg, 2023-08) Muhammad Ahsan, Mahboob; Celik, Turgay; Genc, Bekir
Exploring mineral resources and transforming them into ore reserves is imperative for sustainable economic growth, particularly in low income developing economy countries. Limited exploration budgets, inaccessible areas, and long data processing times necessitate the use of advanced multidisciplinary technologies for minerals exploration and resource estimation. The conventional methods used for mineral resources exploration require expertise, understanding and knowledge of the spatial statistics, resource modelling, geology, mining engineering and clean validated data to build accurate estimations. In the past few years, data science has become increasingly important in the field of minerals exploration and estimation. This study is a step forward in this field of data science and its integration with minerals exploration and estimation. The research has been conducted to develop a state-of-the-art data science framework that can effectively use limited field data with remotely sensed satellite data for efficient mineral exploration and estimation, which was validated through case studies. Satellite remote sensing has emerged as a powerful modern technology for mineral resources exploration and estimation. This technology has been used to map and identify minerals, geological features, and lithology. Using digital image processing techniques (band ratios, spectral band combinations, spectral angle mapper and principal component analysis), the hydrothermal alteration of potential mineralization was mapped and analysed. Advanced machine learning and geostatistical models have been used to evaluate and predict the mineralization using field based geochemical samples, drillholes samples, and multispectral satellite remote sensing based hydrothermal alteration information. Several machine learning models were applied including the Convolutional Neural Networks (CNN), Random Forest (RF), Support Vector Machine (SVM), Support Vector Regression (SVR), Generalized Linear Model (GLM), and Decision Tree (DT). The geostatistical models used include the Inverse Distance Weighting (IDW) and Kriging with different semivariogram models. IDW was used to interpolate data points to make a prediction on mineralization, while Kriging used the spatial autocorrelation to make predictions. In order to assess the performance of machine learning and geostatistical models, a variety of predictive accuracy metrics such as confusion matrix, a receiver operating characteristic (ROC) curve, and a success-rate curve were used. In addition, Mean Absolute Error, Mean Square Error, and root mean square prediction error were also used. The results obtained based on the 10 m spatial resolution show that Zn is best predicted with RF with significant R2 values of 0.74 (p < 0.01) and 0.7 (p < 0.01) during training and testing. However, for Pb, the best prediction is made by SVR with significant R2 values of 0.72 (p < 0.01) and 0.64 (p < 0.01) for training and testing, respectively. Overall, the performance of SVR and RF outperforms the other machine learning models with the highest testing R2 values. The experimental results also showed that there is no single method that can be used independently to predict the spatial distribution of geochemical elements in streams. Instead, a combinatory approach of IDW and kriging is advised to generate more accurate predictions. For the case study of copper prediction, the results showed that the RF model exhibited the highest predictive accuracy, consistency and interpretability among the three ML models evaluated in this study. RF model also achieved the highest predictive efficiency in capturing known copper (Cu) deposits within a small prospective area. In comparison to the SVM and CNN models, the RF model outperformed them in terms of predictive accuracy and interpretability. The evaluation results have showed that the data science framework is able to deliver highly accurate results in minerals exploration and estimation. The results of the research were published through several peer reviewed journal and conference articles. The innovative aspect of the research is the use of machine learning models to both satellite remote sensing and field data, which allows for the identification of highly prospective mineral deposits. The framework developed in this study is cost-effective and time-saving and can be applied to inaccessible and/or new areas with limited ground-based knowledge to obtain reliable and up- to-date mineral information.
A model for integrated tourism infrastructure planning in the South African public sector
(2024) Chettiar, Shamilla
Infrastructure supports competitiveness, productivity and economic growth. While planning is critical for co-ordination and delivery of infrastructure, integrated infrastructure planning models remain elusive. Integrated infrastructure planning is especially important to derive maximum benefits from limited public sector funding. This research focussed on infrastructure planning in the tourism context. Within the complex South African public sector planning system, the responsibility for infrastructure and tourism planning lies with multiple departments at national, provincial and local government spheres. Tourism infrastructure needs can therefore best be addressed through integrated planning. This thesis presents the results of a qualitative, multi-method study. Various methods, such as reviews of documents, key-informant interviews, focus groups and case studies were utilised to gather data. The research also contains the reflections of the researcher who has extensive experience in public sector planning. The research question was: “What are the key elements of a model for integrated tourism infrastructure planning undertaken by the South African public sector?” The model proposes three key elements - a National Tourism Spatial Development Framework; Regional Tourism Masterplans; and a Tourism Infrastructure Strategy and Plan. A People component has also emerged as being significant for the effectiveness of the model. The study further confirmed that the model will support the integration of tourism, economic, spatial and infrastructure planning and development. In the long - term integrated public sector tourism infrastructure planning in South Africa, should yield greater public sector investment, stimulate greater private sector investment, and ultimately support the growth and competitiveness of the tourism sector. This research makes a significant contribution to knowledge for integrated infrastructure planning.
A Symphony of Sakina: Using mosque design to facilitate community development in Mooiplaas
(University of the Witwatersrand, Johannesburg, 2024-02) Jaffer, Raeesah; Janse van Rensburg, Ariane
This research report studies Mooiplaas Informal Settlement in Pretoria, South Africa. The research first discusses the developmental challenges of this marginalised community and then investigates ways in which informal settlements can be developed. It explores the design and application of a Mosque complex, focusing on its potential to facilitate community development. Mooiplaas has a growing Muslim population, and a Mosque is a fundamental requirement to facilitate prayer. The Mosque is further investigated to understand its significance and functionality in community settings throughout history. Previous developmental initiatives undertaken have not reached full potential to holistically address the needs of the Muslim and non-Muslim communities in Mooiplaas. Thus, this research investigates ways the Mooiplaas community can enhance resilience and sustainability by applying the Mosque complex as a fundamental instrument for future development initiatives. The proposed Mosque can facilitate social and economic upliftment within the settlement by providing spiritual development and education and promoting social cohesion.
Acid[c]ity - Undamning the Dam: Wicking of the Harmony Gold Mine Dam Through Algae Exploration
(University of the Witwatersrand, Johannesburg, 2024-02) Le Pere, Justine; Doermann, Kirsten; Daskalakos, Christos
This project discusses the need to help fight against the effects of mining on water, and to help the surrounding environment and community. A large emphasis is placed on the use of algae to treat the water from the Harmony Gold Mines’ tailings dams, and the facility plays host to this natural water treatment method. The facility provides the space for water resource management and water treatment education to take place. The community of Tshepisong Phase 2 lies north of the facility and acts as the activator of the facility. Without the community needing to collect water for use at home, the facility would not have a strong sense of integration into the township. The layout of the facility allows the layers of privacy to help aid the program, and the program allows the facility to be transparent to its visitors and the neighbouring township.
Action volume ratio: a method to classify the danger of lightning in any given volume
(University of the Witwatersrand, Johannesburg, 2015-05-07) Dickson, Andrew Stuart
The annual number of injuries and fatalities from lightning has, over the last century, been on a steady decline. This is primarily due to urbanisation and movement away from agriculturally intensive activities. In countries with a high urban population, the incidence of lightning fatalities is below 1 death per million people per year. However, in countries with a larger rural population, this rate is significantly higher, ranging between 8 and 15 deaths per million people per year. There has been a large drive towards educating the general public about the dangers of lightning and methods to avoid being in a dangerous situation. However, fatal lightning events still occur on a regular basis. There are currently no methods to determine the risk of lightning to living beings in open spaces. The international standard (IEC 62305-2) provides a method for the assessment of risk to living beings within a structure, and up to three metres outside of it. Considering that the majority of deaths by lightning occur outdoors, a method of determining these risks is necessary. The Action Volume Ratio (AVR) is proposed as a new method for the analysis of the danger of lightning in any volume. It considers the dangers of all lightning injury mechanisms in relation to the objects in the space, which are assumed to be the preferential points of strike. A union of the dangerous volumes is then formed, and a ratio to the total volume is created. The AVR uses accepted electrical engineering equations to determine the dangerous areas, and places no reliance on probability theory, which can, in many cases, skew the results of a lightning risk analysis process. The AVR can be combined with lightning ground flash density data to indicate the incidence and frequency of dangerous events within a given volume.
Addressing high dimensionality in water quality modelling in water distribution networks
(University of the Witwatersrand, Johannesburg, 2024-02) Machweu, Morongwa Ednah; Taigbenu, Akpofure
Water quality models are the most effective tools for characterizing water quality conditions, assessing the effects of water pollution, and supporting decision-makers with water quality management. They can be utilised for detecting the variations in the water quality parameters. Despite the usefulness of water quality models, an appropriate and simple water quality descriptor for a particular application, considering the high dimensionality of various water quality parameters, remains a challenge (Chapman, 1992). To address this high dimensionality, a single dimensionless index is commonly used to describe water quality for a particular application. While pollution loads at various points in a river reach have been widely assessed by studies using water quality indices, little research has been done on water distribution networks with service reservoirs and a variation of loading conditions. In a water distribution network, service reservoirs function similarly to rivers in that they have complicated mixing mechanisms, are subject to a variety of water quality factors, and are sized and located differently. The most common water quality indices require the formation of subindices and weights to avoid ambiguity, eclipsing and rigidity. The Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) does not require the formation of sub-indices and weights, thus providing a simplified way of describing water quality. This study investigates the use of the CCME WQI to address high dimensionality in water quality modelling of water distribution networks, taking into consideration the locations of multiple service reservoirs. This study was carried out primarily for decision-making and design optimization purposes only. Using EPANET 2.2, four hydraulically optimised solutions (which satisfied minimum pressure requirements) were further analysed for water quality performance. This was achieved by incorporating simulated data on three water quality variables (chlorine residual, water age and THM concentration) into the CCME WQI for a hypothetical water distribution network, Anytown. The results indicate that two of the four hydraulically optimised solutions achieved excellent water quality levels. This study has demonstrated the usefulness of a dimensionless index as a proxy for multiple water quality variables of a water distribution system in facilitating decision-making.
Alternative Tenure Options as a Stepping Stone for Urban Land Reform: The Case of Kwa Mai Mai Muthi Market
(University of the Witwatersrand, Johannesburg, 2024-02) Mnguni, Thobeka; Maina, Miriam M.
This research uses qualitative methods to investigate the case of the Kwa Mai Mai muthi market located in the central business district of Johannesburg where over the decades informal traders have converted their trading units into residential homes. This case is used to respond to the research question, ‘To what extent is taking administrative action to improve land tenure by offering communities rights to occupy urban land feasible and necessary for advancing the urban land reform agenda?.’ The research acknowledges that popular approaches to improving tenure by converting insecure tenure rights to statutory ownership through the Deeds office has had limited success and resulted in efficiencies due to the high costs and the resources intensive nature of this approach. Instead, the research recommends a necessary transition to improving tenure in innovative, context-specific ways that work to build on existing settlements through taking low-cost and low LOE administrative action.
An application of John Rawls' principles of social justice to planning: issues arising from the implementation of the national housing subsidy programme in the inner City of Johannesburg
(2024) Oelofse, Michael Gerald
John Rawl' s conception of social justice has had a fundamental influence on liberal ethics yet its practical implications for distributive planning have rarely been considered in any comprehensive way. This is the key contribution of this thesis. Using the South African housing subsidy system, it examines how distributional policies may be structured to benefit the least advantaged and explores the consequences of their implementation in Johannesburg's inner city. Based on a literature review, it argues that Western planners often place the responsibility for distributional decisions on political processes, or concern themselves with maximising the public good without addressing the consequent allocation of the costs and benefits among members of society. Contemporary planning theory continues to avoid the substantive c.9ntent of social justice. Confronted with what seem to be equally valid, often competing conceptions of social justice, planners focus on the fairness of planning procedures instead of taking normative, principled positions on distributional outcomes. However, just procedure alone does not guarantee a just outcome. This requires adherence to some predefined set of distributional principles, and Rawls' political conception of social justice is presented here as a reasonable and compelling option for planners. Drawing on the author's practical experience, this thesis traces the liberal influence on the formulation of housing subsidy policy in South Africa and argues that national policy generally conforms with Rawlsian distributional principles. However, an empirical analysis of the housing sector in Johannesburg's inner city reveals that its impact is dissipated by a lack of local commitment to the original principles. Conflicting development principles and a failure among many residents to honour the obligations attached to housing benefits compound the problem. This thesis concludes that Rawlsian principles of social justice in combination with the contemporary communicative turn in planning provide planners with a powerful means of placing social justice on the development agenda, but that these principles require championing because conflicting principles and interests continuously place the needs of the least advantaged at risk.
An Investigation of Factors Contributing to Long Waiting of Patients Collecting Repeat Medication in a Tertiary Hospital Pharmacy
(University of the Witwatersrand, Johannesburg, 2023-02) Oladipupo, Rekgopetse Victoria; Hattingh, Teresa; Sunjka, Bernadette
According to the World Health Organization (WHO) patient waiting time is identified as a key measurement to a responsive healthcare service and is an important indicator of quality of services offered by hospitals (NDoH, 2011) as it affects the patient’s responsiveness to the services received (NDoH, 2011; SA FAM PRACTICE, 2008; Tegabu, 2008; Pandit et, al. 2016). Long waiting times at healthcare facilities undermines the services rendered resulting in compromised or unfulfilled patient care (Afolabi & Erhun, 2003). This research studies the processes associated with the collection of repeat medication in a tertiary hospital pharmacy in order to identify value adding activities and non-value adding activities that could be impacting patient waiting time using the Lean thinking concept of driving out waste. A qualitative observational method was therefore employed to observe all the steps involved during the journey of the patient collecting repeat medication from the registration point until medication was issued at the pharmacy. Value stream mapping (one of Lean Thinking principle) was employed to analyze the processes that took place. Patient waiting time was also measured from the registration point to the pharmacy. On average patients had to wait a total 159 minutes before they could access services both at the registration point (67 minutes) and at pharmacy (92 minutes). The service time was 29 minutes at both registration point (11 minutes) and pharmacy (18 minutes). Of the 18 minutes pharmacy service time; eight minutes were found to be value-adding while 10 minutes were non-value-adding mainly due to prescriptions waiting on queue to be picked, waiting to be signed by the pharmacist and waiting to be issued out to the patient. Lack of a dedicated pharmacy service points exclusively for chronic repeat patients, manual dispensing, illegible doctor’s prescriptions, were found to prolong the time it takes the Pharmacist to complete a prescription. Post Basic Pharmacist Assistants performing duties that could be performed by a less qualified staff (e.g., Learner Basic Pharmacist Assistants) during peak hours was not value adding and thus decreasing productivity. The level of staff commitment in addressing issues of quality such as long waiting time was questionable. The demand / workload and capacity during the early hours of business at the registration point did not seem to match, thus resulting in bottlenecks at the patient registration point and throughout the system.
An investigation on the impact of landownership dynamics in rural development: A case of Nooitgedacht area in Muldersdrift, Mogale City Local Municipality
(University of the Witwatersrand, Johannesburg, 2024-02) Masonganye, Thoriso Obakeng; Sithagu, Taki
South Africa's history of land ownership is deeply intertwined with the legacy of colonialism and segregation. In the contemporary context, land ownership has emerged as a pivotal catalyst for rural development, aimed at addressing historical injustices and fostering sustainable socio-economic growth. Despite numerous reforms and initiatives introduced since the dawn of democracy, challenges persist, particularly in rural regions like Nooitgedacht in the West of Gauteng. In Nooitgedacht, landlessness, underdevelopment, poverty, and minimal economic activity continue to plague the community. This study delves into the intricate relationship between land ownership dynamics and rural development, with a specific focus on Nooitgedacht within the Mogale City Local Municipality. To comprehensively assess this issue, a multi-faceted research approach was employed, incorporating primary and secondary data collection methods. The research methods encompassed a thorough desktop survey, the distribution of questionnaires to community members, and in-depth interviews with municipal officials and community stakeholders. The desktop survey harnessed municipal valuation data to discern the existing patterns of land ownership in Nooitgedacht, revealing a marked imbalance, with most of the land controlled by private individuals and businesses, while national, provincial, and local governments held relatively merger land ownership within the study area. This skewed ownership pattern underscores the profound challenge of land access in Nooitgedacht. Consequently, the area grapples with persistent land inequalities encompassing issues of access, ownership, distribution, and administration, which further manifest through ongoing threats of land invasions, evictions, limited development, and a dearth of economic activities. Despite the presence of municipal policies aimed at addressing these disparities, implementation remains sporadic, fragmented, and inadequately coordinated within the municipality, resulting in a sluggish delivery of rural development. In conclusion, the study underscores the pivotal role of land ownership in shaping the trajectory of rural development in Nooitgedacht. It is evident that without equitable and well-coordinated land ownership policies and practices, the goal of achieving sustainable rural development in this region remains an elusive aspiration.
Analysis of the developmental potential of artisanal and small-scale mining: a strategy for South Africa
(2024) Twala, Pontsho Francinah
The mining industry remains central to the socio-economic development of mineral economies. While this is the case, most African countries have been struggling to translate the benefits of mining into positive developmental outcomes. This has been attributed to several factors including the failure to leverage opportunities from the Artisanal and Small-Scale Mining (ASM) sector which has been growing in most countries. As is the case in other African countries, the mining industry continues to play a considerable role in South Africa’s economy. The industry is expected to contribute significantly to the country’s socio-economic agenda which aims to eradicate poverty and inequality by 2030. Despite the positive outlook, the performance of the industry has been declining resulting in the government identifying a series of interventions aimed at reviving the industry’s activities. Amongst these is the formalisation of the ASM which has been earmarked for job creation and poverty alleviation. The objectives of the Thesis were to establish the developmental potential of ASM in the country, and subsequently develop a strategy framework aimed at enabling the sector to contribute to the mining industry and national development plan. The study was conducted using multiple case studies with data collected and analysed using multiple methods. The major finding from the study is that the ASM sector has the potential to contribute towards the country’s development priorities. This is taken from the evidence that shows a direct link between the sector’s activities and the country’s socio-economic landscape. It was established that the main drivers of ASM are socio-economic challenges in the country, mainly growing unemployment and poverty levels. To this end, ASM is playing a role in providing livelihoods to country’s population is that most affected by poverty and unemployment. As a livelihood strategy, ASM has improved the poverty status as well as the living standards of those that participate in its activities. The evidence from the study revealed that most of the miners measure above the country’s subsistence level and can provide for themselves and their families. The benefits of the sector also extend to communities and overall, these can be linked to several objectives as captured in the country’s development plan. The conclusion from the study is that the developmental potential of ASM can only be leveraged if the challenges in the sector are addressed, and these encompass issues relating to the regulation of the sector, mining land and mineral resources; value chain constraints, and related support, responsible practices, institutional arrangements, and ASM stakeholder relationships.
Application of derivative techniques to improve the forecasting of price volatility of copper, gold and platinum metals
(2024) Veriyadi, Veriyadi
This research investigates the forecasted price volatility of copper, gold and platinum metals based on the selected companies; Palabora Copper Mining Ltd, AngloGold Ashanti Ltd, Gold Fields Ltd, Sibanye-Stillwater, Anglo Platinum Ltd and Impala Platinum Ltd. In responding to the latter sentence, single price volatilities are dual volatilities, where dual volatilities comprise of financial and technical variables. The selected firms either have global operations or they are subsidiaries of global companies. Dual volatility is computed using a Sample Correlation Coefficient and in order to explore the dual volatility, this research introduces three hypotheses. The first hypothesis uses a Decision Tree Analysis to test dual volatility based on financial and technical variables (e.g., mineral commodity price, metal grade, operating cost and production rate) in improving the forecasting of price volatility of copper, gold and platinum metals. For validation, the first hypothesis uses the Markov-Regime Switching Model. The results of this hypothesis illustrate that dual volatilities are more accurate and robust than price only volatilities. Then, the second hypothesis examines dual volatility using a GBM model. This hypothesis tests dual volatility; which is computed based on financial and technical variables (e.g., oil price, copper price, oil production and consumption, copper production and consumption; and the exchange rate from U.S.$ to ZAR and gold and platinum price data). The chosen variables that affect the dual volatility are examined using a Multiple Regression Model and that model confirms that those variables are independent in principle. Finally, the third hypothesis estimates future profits based on a binomial tree, which has risk-neutral probabilities based on dual volatility using mineral commodity price, metal grade, operating cost and production rate. The results of risk-neutral probabilities using dual volatility are less optimal than a mineral commodity price volatility due to not accounting for the mean of logarithmic returns. The robustness test uses the VAR model, which indicates that the profits react differently to different shock stages from revenues, risk-free interest rates and profits. In conclusion, dual volatility can improve future price forecasting performance because duality is underpinned by different variables, which include independent variables from the global commodity markets. The forecasting performance improvement from dual volatility in predicting the future price can be shown by the lower value of the Root Mean Square Error and Mean Absolute Percentage Error results than a mineral commodity price volatility. The findings of this research apply to copper, gold and platinum metals for mining around the globe.
Architecture as mnemonic experiencing past, present, and future narratives in a Johannesburg cultural complex
(2024) Segal, Yehuda
Memory is transient, it comes and it goes. It is a passing remembrance of a past time, person or place. Memory is the experience we store in our minds to recall at a future time and date. It is the friends we make on the first day of school, our childhood holidays, or beach sand between our toes. Memory is also stored in books, visuals, art, and the internet. It is the long-gone monarch in a painting, the photographs and videos of historical events that record a past time and people. And so, memory is architecture- or, simply, space. Spatial recall- the ability to remember a space or place, directions from point A to point B, is the reason we find our way when lost. The architecture of memory is related to that of structures, buildings and spaces that serve to record or preserve a past event or person, yet also the landmark that guides us. It is a museum, memorial, triumphal arch and even a religious or cultural space. It is also the old as opposed, or in harmony with, the new. Architecture as mnemonic is relatable to other aspects and devices with mnemonic value. Memory is therefore an important aspect of archi - tecture and the built world. Not only do we remember through spatial interactions, we also experience spaces which lead to us creating new memories.
A bathhouse in Cyrildene - a phenomenological approach to the design of a bathhouse in Johannesburg
(2021) Kow, Alan
In Johannesburg, there is a lack of global bathhouse typologies. They either don’t exist or are in a form which caters to a niche subculture. Bathhouse culture has been around for hundreds of years and many people around the world take advantage of it as a form of communal bonding, relaxation and general hygiene. In addition to this, when done correctly, it has the effect of stripping away of social class and distinction as well as providing a safe and entertaining environment for those within its walls. This study aims to bring my personal experience of an East-Asian bathhouse into Cyrildene, a predominantly Chinese neighbourhood, that is slowly losing its cultural identity. Building on existing data on historic bathhouses from around the world, it asks: How can the concept of phenomenology be used to guide the design of an Asian style bathhouse in order to enhance the Asian/Chinese cultural experience and help in the revitalisation of Derrick street as a distinct cultural hub In Johannesburg? The main methodologies that will be used in this report will be from literature reviews on historical analysis of bathhouses around the world but more specifically in Eastern Asia. One on one interviews with the residents and shop owners living in Cyrildene as well as the owner/s of a spa. Observations based on mapping and photography will also be employed. The last will be the use of auto-ethnographic data from my own experiences. The main hypothesis of the report will be seeing if the bathhouse typology through the use of a variety of different programs that range from bathing to eating to sleeping in addition to the application of architectural phenomenological theories helps make it suitable for Cyrildene and thereby revitalise and strengthen the areas existing cultural identity.
Benefits of using Internet of Things technology for fuel management at a mechanised underground platinum bord and pillar mine: A Bathopele mine case study
(University of the Witwatersrand, Johannesburg, 2024-01) Thema, Sephela Makete; Cawood, Frederick; Feroze, Tariq
The advent of the fourth industrial revolution, Environmental Social and Governance (ESG), and push for green energy transition has propelled mining companies to reconsider their strategies. Over the past two decades, mining companies along the Bushveld Igneous complex in South Africa have been shifting towards mechanized mining methods which are generally safer and provide for the generation of greater volumes of output. Sibanye Stillwater’s Bathopele mine, which has a fleet of over two hundred and fifty (250) trackless mobile machinery (TMM) and a daily fuel consumption of approximately ten thousand (10 000) liters per day. The introduction of Internet of Things (IOT) technology in the fuel management system at Bathopele mine achieved benefits such as fuel consumption tracking, effective inventory management, prevention of fuel theft, detection of fuel leaks, determination of maintenance requirements and readily available access to fuel use data. This access to data enabled the mine to effectively apply for fuel use rebates from the South African Revenue Services (SARS) with ease. To determine the impact of the increased distance to underground working places on the refueling of TMM, the Theory of Constraints (TOC) method, qualitative and quantitative techniques were applied. A bivariate analysis conducted indicated a linear relationship between fuel consumption and production output at Bathopele mine, which suggests that an effective fuel management system had a positive impact on production output at the mine. A real-time or near real time model for fuel management in underground trackless bord and pillar mines in proposed.
Bridging the Past: Redeveloping parts of Fordsburg to create secure and empowering environments for women
(University of the Witwatersrand, Johannesburg, 2024-03) Dar, Sarah; Szentesi, Anita
The safety of women in public spaces has become an increasingly unsettling issue in South Africa. One of the most severe violations of human rights that still occurs in communities worldwide is gender-based violence, a phenomenon that has a foundation in gender inequity. Gender-based violence affects both men and women, but women and girls comprise most of victims. Public spaces have favored the safety of men, whereas women struggle for their wellbeing in the same space. There is a need for a re-imagined women only space concept, in which women can evolve in, in hopes of creating safer spaces. (UN-Habitat, 2015). The proposal for this thesis is a Skills and Development Centre for women. The Centre will aim to create women run businesses in male dominated spaces with the research focusing on women empowerment through education, and further investigating past architectural theories on women-only design.
Change the GOAL: Promoting sports & community engagement through the integration of FNB Stadium
(University of the Witwatersrand, Johannesburg, 2024-02) Ramsarup, Shreya; Kirkman, Deborah
South Africa has invested many billions of rands to build and renovate stadiums. This investment has some advantages, such as fostering national pride and boosting political and economic agendas. However, the benefit to the ordinary citizen is exaggerated. This is evident at the FNB Stadium, while used for elite sport, majority of the Soweto community do not come to the stadium. To the local community it a symbol of something beyond their lived worlds. Against this context my project explored how the FNB stadium can become a sport and cultural led space that locates local people at the center of its use identity. I explored the design of the stadium precinct as a mixed-use space with a focus on sport and football development, allowing opportunities for more people to better connect and understand what the stadium has to offer. This re-imagining of FNB as a stadium fostering broader community aims helps to break the pattern of the stadium as an alienated icon within this historically disadvantaged community.
Comparative study of five country-specific labour-intensive infrastructure development programmes : implications for South Africa
(University of the Witwatersrand, Johannesburg, 2010) Quainoo, Harry Akyen; McCutcheon, R.T.
Unemployment and abject poverty in South Africa are widespread, persistent and disproportionately high. These problems are aggravated by inadequate capacity at all tiers of government and huge infrastructure backlogs in rural South Africa. Employment-intensive means of infrastructure delivery have been successfully implemented in several sub-Saharan African countries and elsewhere to generate employment and reduce poverty. It should be possible to replicate similar large-scale national programmes in South Africa. But South Africa has failed. Both prior to and since 1994, several supposedly employment-intensive programmes have been implemented in South Africa with poor results. In an endeavour to contribute to future South African policy and good practices regarding employment, this thesis describes and analyses in detail five major Sub-Saharan programmes and reaches conclusions regarding their achievements and shortcomings. Lessons derived bridge the knowledge gap between the large-scale programmes embarked upon in the sub-Saharan countries in the mid-1980s and the year 2007; these lessons should be applied to future endeavours in South Africa to generate significant employment per unit of expenditure and contribute to poverty alleviation. A major conclusion reached was that the success of employment-intensive infrastructure development programmes depends to a large extent on fundamental factors such as appropriate and implementable policy, government commitment, adequate and sustainable funding, adequate capacity and good preparation. Specifically, the thesis demonstrated that prior to implementation a sufficient timeframe is required for programme preparation in order to make significant contribution towards poverty reduction. Equally, national programme expansion requires a strategic balance between centralisation and decentralisation. In particular, for programme extension and decentralisation, due regard must be given to training and capability building and available resources. Deriving from the thesis’ major conclusions, the author developed three crucially important frameworks for anti-poverty infrastructure development programmes, namely; a four-phased model for evaluating the chances of success of infrastructure programmes, a five-phased result-oriented guidelines for testing the workability of infrastructure development policies, and a practical guideline for monitoring and evaluating employment-creation programmes that maximises the benefits thereof and pre-empts institutional memory loss through systematic knowledge management.
A comparison of various modelling techniques to optimise production rate on a platinum mining project
(2021) Dreyer, Jaco
Every business aims to create an optimal economic value for its shareholders. The production rate is one of the critical drivers of value in the mining business. Several approaches have been developed to determine the production rate for mining operations. This study applied three approaches for determining production rate, namely the tonnage-based, microeconomic and marginal-analysis modelling methods. These methods were applied on a platinum project, and the production rate results from the three methods were used to determine the life of mine (LOM) production profiles, capital expenditure (CAPEX) and operational expenditure (OPEX). These results were then used as inputs into a discounted cash flow (DCF) model. The DCF model results were compared and analysed to determine a production rate determination method that results in an optimum production output rate for the project. The study revealed that the tonnage-based modelling technique resulted in the highest production rate of 410-kilo tonnes per month (ktpm), the highest CAPEX of USD957.24 million, the lowest OPEX of USD75.37 per mined tonne, the highest net present value (NPV) of USD63.12 million and the highest internal rate of return (IRR) of 12.85% over a 40-year LOM. The microeconomic modelling technique ranked second with a production rate of 270 ktpm, CAPEX of USD 726.24 million, OPEX of USD 76.68 per mined tonne, NPV of USD 3.46 million and IRR of 10.17%. The marginal-analysis modelling technique ranked last with a production rate of 230 ktpm, CAPEX of USD 658.76 million, OPEX of USD 77.83 per mined tonne, NPV of USD -10.69 million and the lowest IRR of 9.47%. Mineral Resource tonnage-based modelling may be further investigated in other commodities other than platinum or other multi-element/polymetallic mineral deposits in line with the South African mining industry. This will result in the formulation of industry-specific calibration in the South African mining industry
Control of Aerial Manipulators for Contact Inspection
(University of the Witwatersrand, Johannesburg, 2023-10) Matosse, James; Kuchwa-Dube, Chioniso
Aerial manipulators are flying robotic systems that consist of a multi-rotor vehicle tailored with one or more manipulators. These systems are promising for contact inspection of chemical plants, boilers, tunnels and chimneys without human intervention. They require sophisticated control algorithms for control and stabilisation of complex varying dynamics due to the flying, manipulating and interacting with the environment. The dynamics of an aerial manipulator are treated as two subsystems, the quadrotor and the manipulator. The quadrotor dynamics are extracted through the Newton-Euler algorithm using quaternion-based orientation instead of Euler angles. The manipulator dynamics are extracted using the recursive Newton-Euler equations for purposes of handling the floating-base effect. A classic impedance control is a widely used effective control for contact force tracking but it requires the location of the environment relative to the end-effector and the environmental stiffness to be known precisely, and mostly- the desired force as a constant. In contact inspection without human intervention, the environmental properties (geometrical and mechanical) are uncertain, causing the classic impedance control method to be less effective. Presented in this study are: an adaptive variable impedance control (AVIC) for force tracking combined with the integral linear quadratic regulator (LQR) for the quadrotor and proportional-derivative (PD) for the manipulator’s navigation control. AVIC has the capability to counteract for environmental uncertainties by varying the impedance parameter (damping coefficient) on-line corresponding to the force tracking error. This control has been utilised effectively in industrial robot manipulators for a stable force tracking performance. So far in the literature, AVIC together with integral LQR and PD controllers have not been applied to aerial manipulators as a control strategy. Since the aerial manipulator is a coupled system, a linearisation process was performed on the quadrotor dynamics coupled with the manipulator to achieve a fair approximation of the non-linear model. This study has improved force tracking abilities through the implementation of AVIC that allows the aerial manipulator to achieve a desired contact force on the inspected contour while the quadrotor remains in a stable position. Finally, the developed system was simulated using MATLAB/SIMULINK program and the attained results proved the effectiveness of the strategy in comparison to the classic impedance control.

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