List of Titles

Physical activity, physical fitness, sedentary behaviour and screen time profiles of primary school children in a school within the Makana Municipality, Eastern Cape, South Africa

- Kade, Andréa Gaby

Authors: Kade, Andréa Gaby
Date: 2021-04
Subjects: Sedentary behavior in children -- South Africa -- Makana Municipality , Physical fitness for children -- South Africa -- Makana Municipality , Exercise -- Physiological aspects , Exercise -- Health aspects , Diabetes -- Risk factors , Heart -- Diseases -- Risk factors
Language: English
Type: thesis , text , Masters , MSc
Identifier: http://hdl.handle.net/10962/177282 , vital:42806
Description: There is a lack of data on the physical activity, physical fitness and sedentary behaviour of children in South Africa. Furthermore chronic diseases such as type II diabetes and coronary heart disease have been linked to childhood inactivity, and improving cardiorespiratory fitness and increasing levels of physical activity has been shown to be beneficial in reducing the risk of such diseases. In South Africa more broadly there is a lack of information on levels of physical activity and sedentary behaviour as well as physical fitness measures particularly in children. Objective: The purpose of this study was to enhance the existing body of knowledge on this, by measuring the prevalence of physical inactivity, sedentary behaviour and screen time of primary school children in a private school from the Makana Municipal region in the Eastern Cape Province of South Africa, where the evidence is most sparse. A secondary aim was to assess levels of physical fitness in this cohort, as well as to compare across grades and sexes. Method: After ethical approval was granted, stature and body mass measurements were taken and body mass index was computed for primary school children (Grade one to seven) from a private school in the Makana Municipality. Sitting stature was measured in order to determine each child’s peak height velocity and maturity offset. Five different physical fitness tests were conducted on the children and blood pressure and heart rate values were measured at rest. Physical activity and screen time questionnaires were completed by the children’s parents for a seven day period. Results: Females were found to mature faster than males. In addition females were more physically active (Females= 916 min/week; Males= 669 min/week) while also accumulating more sedentary time (Females= 1241 min/week; Males= 970 min/week) as compared to males, although no significant differences were found between males and females for these variables. The sample participated in more than 60 minutes of moderate-to-vigorous physical activity and less than two hours of screen time daily, which is in accordance with guidelines. No differences were found between grades and sexes for accumulated screen time. Strength increased significantly with grade and age, and there were also statistical differences between the sexes for all three strength measures with males being stronger than females. Females were more flexible than males and no statistical differences were found between sexes for the shuttle run test. Blood pressure correlated positively with mass, as did all the strength measures as well as maturity offset. No correlations were found between screen time and all other variables. A negative relationship was recorded between screen time and physical activity, although not significant. For females a strong positive correlation was found between sedentary behaviour and physical activity. Conclusion: The study was successful in adding to the body of knowledge regarding the prevalence of physical inactivity, sedentary behaviour and screen time within school children from the Makana Municipality in the Eastern Cape Province of South Africa. The sample was considered physically active as they accumulated on average more than 60 minutes of moderate-to-vigorous physical activity daily (Males= 96 min/day; Females 130 min/day), which is in accordance with guidelines recommended by the World Health Organization (World Health Organization, 2018). The sample accumulated more sedentary behaviour than physical activity, although not significant. Screen time was below regulations of two hours daily, indicating this population participated in more non screen related sedentary behaviour. More research is needed into the risks presented with different forms of sedentary behaviour. Physical fitness increased with increasing grade and age and males were considerably more fit. The current study did not present any concern with regards to the effects of increased physical activity and fitness levels within school aged children. More research into the current levels of physical activity, physical fitness and sedentary behaviour of school aged children in South Africa in general, and in the Eastern Cape Province, is needed. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
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Date Issued: 2021-04

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'n Ondersoek na genderpolitieke kwessies in die kortverhale van Rachelle Greeff

- Gelderblom, Zel-Marí Kato

Authors: Gelderblom, Zel-Marí Kato
Date: 2020
Subjects: Women -- Political activity
Language: Afrikaans
Type: Thesis , Masters , MA
Identifier: http://hdl.handle.net/10948/50756 , vital:42666
Description: Hierdie verhandeling fokus op die genderpolitieke kwessies in die volgende geselekteerde kortverhale van Rachelle Greeff; “Borste en bandiet”, en “Snaaks watter simpel goed mens onthou”, uit die bundel Die rugkant van die bruid (1990), sowel as “Eters anoniem”, uit die bundel Onwaarskynlike Engele (1993). Die hoofdoel van die studie was om die essensies van genderpolitiek soos deur Greeff aangetoon, te bepaal ten einde die geslagsposisie van die hedendaagse vrou te belig. Daar is gekyk na die manier waarop Rachelle Greeff die fokus op die liggaamlikheid en spesifiek die uiterlike van die vrou plaas, sowel as die manier waarop Greeff stereotipes en taboes rondom die vrou afbreek. Judith Butler se genderteorie is gebruik om hierdie genderpolitieke kwessies te ondersoek, te bespreek en te analiseer. Hierdie is volgens my kennis die eerste verhandeling wat oor Rachelle Greeff se werk handel.
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Date Issued: 2020

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A 150 MHz all sky survey with the Precision Array to Probe the Epoch of Reionization

- Chege, James Kariuki

Authors: Chege, James Kariuki
Date: 2020
Subjects: Epoch of reionization -- Research , Astronomy -- Observations , Radio interferometers
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/117733 , vital:34556
Description: The Precision Array to Probe the Epoch of Reionization (PAPER) was built to measure the redshifted 21 cm line of hydrogen from cosmic reionization. Such low frequency observations promise to be the best means of understanding the cosmic dawn; when the first galaxies in the universe formed, and also the Epoch of Reionization; when the intergalactic medium changed from neutral to ionized. The major challenges to these observations is the presence of astrophysical foregrounds that are much brighter than the cosmological signal. Here, I present an all-sky survey at 150 MHz obtained from the analysis of 300 hours of PAPER observations. Particular focus is given to the calibration and imaging techniques that need to deal with the wide field of view of a non-tracking instrument. The survey covers ~ 7000 square degrees of the southern sky. From a sky area of 4400 square degrees out of the total survey area, I extract a catalogue of sources brighter than 4 Jy whose accuracy was tested against the published GLEAM catalogue, leading to a fractional difference rms better than 20%. The catalogue provides an all-sky accurate model of the extragalactic foreground to be used for the calibration of future Epoch of Reionization observations and to be subtracted from the PAPER observations themselves in order to mitigate the foreground contamination.
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Date Issued: 2020

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A Bayesian approach to tilted-ring modelling of galaxies

- Maina, Eric Kamau

Authors: Maina, Eric Kamau
Date: 2020
Subjects: Bayesian statistical decision theory , Galaxies , Radio astronomy , TiRiFiC (Tilted Ring Fitting Code) , Neutral hydrogen , Spectroscopic data cubes , Galaxy parametrisation
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/145783 , vital:38466
Description: The orbits of neutral hydrogen (H I) gas found in most disk galaxies are circular and also exhibit long-lived warps at large radii where the restoring gravitational forces of the inner disk become weak (Spekkens and Giovanelli 2006). These warps make the tilted-ring model an ideal choice for galaxy parametrisation. Analysis software utilizing the tilted-ring-model can be grouped into two and three-dimensional based software. Józsa et al. (2007b) demonstrated that three dimensional based software is better suited for galaxy parametrisation because it is affected by the effect of beam smearing only by increasing the uncertainty of parameters but not with the notorious systematic effects observed for two-dimensional fitting techniques. TiRiFiC, The Tilted Ring Fitting Code (Józsa et al. 2007b), is a software to construct parameterised models of high-resolution data cubes of rotating galaxies. It uses the tilted-ring model, and with that, a combination of some parameters such as surface brightness, position angle, rotation velocity and inclination, to describe galaxies. TiRiFiC works by directly fitting tilted-ring models to spectroscopic data cubes and hence is not affected by beam smearing or line-of-site-effects, e.g. strong warps. Because of that, the method is unavoidable as an analytic method in future Hi surveys. In the current implementation, though, there are several drawbacks. The implemented optimisers search for local solutions in parameter space only, do not quantify correlations between parameters and cannot find errors of single parameters. In theory, these drawbacks can be overcome by using Bayesian statistics, implemented in Multinest (Feroz et al. 2008), as it allows for sampling a posterior distribution irrespective of its multimodal nature resulting in parameter samples that correspond to the maximum in the posterior distribution. These parameter samples can be used as well to quantify correlations and find errors of single parameters. Since this method employs Bayesian statistics, it also allows the user to leverage any prior information they may have on parameter values.
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Date Issued: 2020

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A business process model for blockchain-based South African real estate transactions

- Tilbury, Jack Laurie

Authors: Tilbury, Jack Laurie
Date: 2020
Subjects: Blockchains (Databases) , Conveyancing -- Technological innovations , Real estate business -- Data processing , Real estate business -- South Africa -- Technological innovations
Language: English
Type: text , Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10962/148380 , vital:38734
Description: The real estate transaction process has been described as inefficient and technologically outdated due to numerous stakeholders and predominantly paper-based operations. Despite the apparent bottlenecks in the current process, the implementation of new technology into the real estate sector has lagged. Several attempts have been made to modernise and digitise the business process but committed integration of assisting technology has lacked attention. This study examined the applicability and potential integration of blockchain technology into the business process of South African real estate transactions. Blockchain’s novelty means that research in this space, especially within South Africa, is limited. Of the research that has been conducted, no models of the business processes for South African or blockchain-based real estate transactions have been constructed. This study provides two business process models, illustrating the two different processes. The main contribution of this paper was an integrated business process model, illustrating how the various processes and stakeholder interactions for South African blockchain-based real estate transactions are conducted on one transaction platform, common to all participating stakeholders. This platform was named the South African Blockchain Land Exchange System (SABLES), which manages and facilitates these transactions in their entirety from start to finish. This model depicts an enhanced business process that provides increased security, transparency, and speed. These benefits will be realised by those who register, adopt, and transact on the platform. Through in-depth interviews, the integrated business process model was assessed. The findings produced a final and combined thematic map, representing the main themes of the analysed interview data, namely blockchain implementation strategies, business process applicability, information technology assimilation, current transaction context, and PropTech 3.0 success factors. The discussion revealed that the current transaction process lacks technological innovation, which increases pressure on the conveyancing role. It was also revealed that there is not only a need within the industry, but a desire, for newer technologies to assist the transaction process. In order to streamline and improve efficiency, business processes should leverage digital records and data, and strive for a solution beyond digitisation, achieving digitalisation. Digitalisation recognises digital documents as official and legal documents as opposed to simply being digital back-ups. This, coupled with the business process models, represent theoretical contributions.
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Date Issued: 2020

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A case study of how a leader shaped the culture of an organisation during a post-merger integration

- Zozi, Vuyokazi

Authors: Zozi, Vuyokazi
Date: 2020
Subjects: Corporate culture -- South Africa -- East London , Leadership -- South Africa -- East London , Organizational behavior -- South Africa -- East London , Strategic planning -- South Africa -- East London , Mission statements -- South Africa -- East London , Government accountability -- South Africa -- East London , Government corporations -- South Africa -- East London , Consolidation and merger of corporations -- South Africa -- East London , Consolidation and merger of corporations -- Management , Crisis management -- South Africa -- East London , Core competencies -- South Africa -- East London , Resource allocation -- South Africa -- East London , Personnel management -- South Africa -- East London , Communication in management -- South Africa -- East London , Qualitative research
Language: English
Type: Thesis , Masters , MBA
Identifier: http://hdl.handle.net/10962/146643 , vital:38544
Description: This research took the form of a case study of the post-merger integration of a government organisation. The study had four objectives, namely to: (1) describe the cultural value of accountability; (2) analyse how strategic leadership and relational leadership roles were exercised to address post-merger integration challenges; (3) analyse how a leader applied selected primary mechanisms to shape organisational culture; (4) analyse how strategic and relational leadership complemented each other in addressing the challenges of post-merger integration and thereby shaping a culture of accountability; and (5) describe how some of the secondary articulation and reinforcing mechanisms supported the culture that was created through primary mechanisms. The literature reviewed, identified some of the critical challenges that are experienced in a post-merger integration, and highlighted the role of leadership in culture formation. The critical challenges that were identified are as follows: What is the vision and organisational purpose? How does the leader structure the organisation? What kind of culture does the leader need to create? How does the leader maintain trust and keep communication with employees? How does a leader build new core competences and develop human capital? Two leadership approaches were adopted, namely strategic and relational leadership. These two leadership approaches were selected because, based on a review of the literature, they appeared to address these post-integration challenges. The roles associated with strategic leadership that were investigated, were creating a vision and purpose for the organisation, developing core competences and developing human capital. From the perspective of relational leadership, this study was concerned with how a leader communicated through regular formal and informal dialogues to keep employees abreast of things, and how the leader built trust. In reviewing the literature linking leadership and culture, the work of Schein (2010) featured prominently. Schein (2010) referred to primary embedding mechanisms that create culture and secondary articulation and reinforcing mechanisms that reinforce or support the culture being created through the primary mechanisms. This study looked at how that happens, and hence six propositions were crafted from the literature. These propositions are as follows: (1) Formal dialogues between the leader and employees demonstrate what the leader pays attention to, measures and controls, which then clarifies what the employees are accountable for. (2) What the leader pays attention to, measures and controls during regular informal interactions between the leader and employees, contributes to strong mutual relationships between them, which promotes ownership and accountability amongst employees for their actions. (3) A leader who behaves consistently when handling critical incidents and organisational crises, is trusted by employees, who then act responsibly and take full responsibility for their actions, and even their mistakes. (4) A leader creates a vision and sense of purpose for the organisation through what he pays attention to, measures and controls, thereby clarifying for employees what they are required to do. (5) A leader who pays attention to developing the organisational core competence and allocates resources to it, instils confidence in his employees with regards to carrying out their own responsibilities. (6) A leader who develops human capital through the allocation of additional resources, thereby instilling confidence in employees who are willing and able to realise or take up their responsibilities. This research adopted a qualitative approach. Data was collected through conducting interviews and the analysis of relevant documents. A deductive thematic analysis of the data was used for the purpose of identifying, analysing and reporting patterns, or themes within the data collected. The research confirmed these propositions as being relevant to the case study. It also confirmed that strategic and relational leadership as reflected in the propositions have complemented one another in the successful implementation of the post-merger integration, thereby shaping a particular culture. It was concluded that the challenges associated with a post-merger integration could not have been addressed through only one of the leadership approaches. The findings of the study also recognised that an architectural role was also required. That is, in a merger, the structure has to be carefully designed and not taken for granted. It was therefore recognised as a critical leadership role. The study considers the implications of the findings and makes recommendations for managers of this organisation, as well as for other organisations that are engaging in a post-merger integration. It further outlines the limitations, delimitations as well as the contribution that the study has made to the body of knowledge. Some of the recommendations made for further research were to analyse how other primary mechanisms that were not part of the propositions may shape the organisational culture; and to research how architectural leadership roles combine with strategic and relational leadership to address post-merger integration challenges. Lastly, this study has explained how leadership, through various mechanisms, shaped a culture of accountability. Other studies can be done using a similar design with different theories of leadership and other mechanisms that apply to shaping other kinds of cultural values.
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Date Issued: 2020

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A cloud adoption framework for South African SMEs

- Mudzamba, Ronald Ratidzo

Authors: Mudzamba, Ronald Ratidzo
Date: 2020
Subjects: Cloud computing , Cloud computing -- Security measures , Small business -- Technological innovations -- South Africa -- Eastern Cape , Small business -- Information technology -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Technology-Organisation-Environment (TOE) framework , Small to Medium Enterprises (SMEs)
Language: English
Type: text , Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10962/148574 , vital:38751
Description: Small to Medium Enterprises (SMEs) have been touted as key enablers to the economic development of most countries. Despite growing evidence that most SMEs fail within their initial years, ICTs have been found to add substantial value in facilitating their success. However, in most developing countries, ICT adoption by SMEs has been plagued with a plethora of challenges ranging from poor electricity supply, high ICT costs, lack of ICT expertise to lack of government support. While this might seem problematic for SMEs, the adoption and the use of cloud services mitigates some of these challenges. The problem, however, is that a limited amount of literature has provided guidance with regard to how the cloud adoption process should be carried out by SMEs. The objective of this research, was therefore, to address this by developing a framework that can be used by SMEs to guide them through the cloud adoption process. To this end, thirteen (13) semi-structured interviews were conducted across nine (9) SMEs in the Eastern Cape. The resultant interview transcripts were analysed using an established thematic approach; the result of which allowed for the development of a rich interpretive narrative about SME cloud adoption. Combined with theory from extant literature, this culminated in the development of a framework for cloud services adoption for SMEs in the Eastern Cape.
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Date Issued: 2020

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A comparative analysis of social media brand image of insurance companies in South Africa: a longitudinal study

- Gudu, Daniel

Authors: Gudu, Daniel
Date: 2020
Subjects: Social media -- South Africa , Internet marketing -- South Africa , Chernoff faces , Ínsurance companies -- South Africa -- Marketing , Insurance companies -- South Africa -- Case studies , Multivariate analysis -- Graphic methods
Language: English
Type: text , Thesis , Masters , MBA
Identifier: http://hdl.handle.net/10962/144277 , vital:38327
Description: Social media is changing the way business is conducted. Almost five billion videos are watched on YouTube every single day. Social media has an extensive worldwide presence. Out of the total global population of over 7,5 billion people, over 4 billion are internet users. Of these, over 3 billion are active on social media. Social media is very influential in today's decision-making processes. Businesses must integrate social media into their strategies. The purpose of this research was to investigate the use of a novel method, Chernoff Faces, to assess and compare the social media brand images of six insurance companies in South Africa based on social conversation measurement. The intention of research was towards observing existing situations at hand and pointing out the game changers that can provide the industry with a new leap. Social media are multidimensional and understanding them requires tracking different measures simultaneously. Integrating social media into a communication strategy leads to a problem in finding the best way to portray and communicate multivariate data. It is essential to find the best way to represent and transmit the data so that marketing executives can quickly and easily monitor changes in brand images. Previous studies have successfully proved the possibility of using this method to gauge a "snapshot in time." This study took the concept further by closely monitoring the results for a set of brands over a period to account for the dynamic nature of social media. Accordingly, the study was a longitudinal study of 30 days. Data on the insurance companies was collected from Social Mention, a social media search and analysis platform that aggregates user-generated content into a single stream of information. A tool in the statistical software Stata, Chernoff's faces, was used to analyse the results by generating facial expressions to the metrics associated with the social mentions of each of the insurance companies. The resulting facial expressions were then analysed to recognise the more favourable and stable brands and those that need appropriate risk management. Managing Social Media is challenging as managers must always keep it as positive as possible. Brand managers, therefore, need a better tool to gauge the mood in social media conversations due to the fast-changing nature of social media and the importance of social media to business especially insurance.
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Date Issued: 2020

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A comparative analysis of the effects of different Levels of Education on growth in African Economies

- Mkhosana, Nomathamsanqa

Authors: Mkhosana, Nomathamsanqa
Date: 2020
Subjects: Economic development -- Effect of education on , Education -- Economic Aspects
Language: English
Type: Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10948/50393 , vital:42161
Description: The economic growth and development of a country depend on the educational opportunities available to its citizens. Education is deemed to influence economic growth via improved labour productivity particularly through knowledge and skills accumulation by promoting technological improvement and innovation. The aim of the study was to highlight the importance of each level of education on economic growth of African countries. The objective of the study was to find which level of education (primary, secondary and tertiary) has the most significant effect on economic growth. To obtain this objective, the study using two panel cointegration methods, the fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS) method applied to data covering the period of 2000 to 2017, the study aimed at sampling 10 educated economies and 10 advanced economies in Africa, since South Africa and Kenya belong in both categories, the study a total of 18 African economies. The results of the study show discrepancies, that is, primary and secondary education being most beneficial towards more advanced economies whilst only tertiary education is beneficiary towards more educated African countries. Policy implications are provided.
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Date Issued: 2020

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A comparative analysis with selected jurisdictions of structural challenges facing the South African office of the tax ombud

- Mothiba, Boitumelo Charity

Authors: Mothiba, Boitumelo Charity
Date: 2020
Subjects: South Africa. Office of the Tax Ombud , Tax administration and procdure -- South Africa , Taxpayer advocates -- South Africa
Language: English
Type: text , Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10962/140360 , vital:37882
Description: The Office of the Tax Ombud is critical in the protection of South African taxpayers' rights. The office has only been in existence for a little over five years and to ensure that it fulfils the purpose for which it was established, it must be properly structured. This includes that it ought to be independent from any external influence and manipulation. Any such external influence on the Tax Ombud creates the risk that the general public will lose confidence in the Tax Ombud as an independent recourse. The study, therefore, is designed to review the structure relating to the independence and powers of the South African Tax Ombud. The study assesses and evaluates the legislative safeguards of the structure of the Tax Ombud office in order to determine whether the legislative framework (the Tax Administration Act) safeguarding the Office of the Tax Ombud is adequate to ensure its independence and also to ensure a strengthened structure, without interference in the decision-making process of the office. To achieve this, a comparative analysis was made with selected foreign institutions of Tax Ombudsmen, or equivalent institutions, in order to draw from the best international practice. The study found that the structure of the Office of the Tax Ombud is relatively weak and does not fully provide the legislative powers to protect taxpayers from the well-resourced South African Revenue Service. The study also revealed that most of the institutional features in the structure of the South African Tax Ombud were found to be in line with standard international practice. The study has made recommendations aimed at strengthening the structure of the South African Tax Ombud by suggesting reforms in the legislative framework of the Tax Ombud.
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Date Issued: 2020

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A comparative mineralogical and geochemical study of manganese deposits in the Postmasburg Manganese Field, South Africa

- Thokoa, Mamello

Authors: Thokoa, Mamello
Date: 2020
Subjects: Manganese ores -- South Africa -- Postmasburg , Geology -- South Africa -- Postmasburg
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/167609 , vital:41496
Description: The Postmasburg Manganese Field (PMF), located in the Northern Cape Province of South Africa, is host to some of the largest deposits of iron and manganese metal in the world. These deposits are restricted to a geographical area known as the Maremane Dome, an anticlinal structure defined by folded dolostones of the Campbellrand Subgroup and overlying ironformations of the Asbestos Hills Subgroup of the Neoarchaean-Palaeproterozoic Transvaal Supergroup. Manganese ores associated with the Maremane Dome have been divided into two major classes in the literature: the Wolhaarkop breccia-hosted massive ores of the Eastern Belt, as well as the shale-associated ores of the Western Belt. The Eastern Belt ores have been classed as siliceous in nature, while the Western Belt deposits are reported to be typically ferruginous. These divisions were made based on their varying bulk chemical and mineralogical compositions in conjunction with their different stratigraphic sub-settings. Presently, both deposit types are explained as variants of supergene mineralisation that would have formed through a combination of intense ancient lateritic weathering in the presence of oxygen, extreme residual enrichments in Mn (and Fe), and accumulations in karstic depressions at the expense of underlying manganiferous dolostones. This study revisits these deposits and their origins by sampling representative end-member examples of both Eastern Belt and Western Belt manganese ores in both drillcore (localities Khumani, McCarthy and Leeuwfontein), and outcrop sections (locality Bishop). In an attempt to provide new insights into the processes responsible for the genesis of these deposits, the possibility of hydrothermal influences and associated metasomatic replacement processes is explored in this thesis. This was achieved using standard petrographic and mineralogical techniques (transmitted and reflected light microscopy, XRD , SEM-EDS and EMPA), coupled with bulk-rock geochemical analysis of the same samples using a combination of XRF and LAICP- MS analyses. Combination of field observations, petrographic and mineralogical results, and geochemical data allowed for the re-assessment of the different ore types encountered in the field. Comparative considerations made between the bulk geochemistry of the different end-member ore types revealed no clear-cut compositional distinctions and therefore do not support existing classifications between siliceous (Eastern Belt) and ferruginous (Western Belt) ores. This is supported by trace and REE element data as well, when normalised against average shale. The geochemistry reflects the bulk mineralogy of the ores which is broadly comparable, whereby braunite and hematite appear to be dominant co-existing minerals in both Eastern Belt (Khumani) and Western Belt (Bishop) ore. In the case of the McCarthy locality, manganese ore is cryptomelane-rich and appears to have involved recent supergene overprint over Eastern Belt type ore, whereas the Leeuwfontein ores are far more ferruginous than at any other locality studied and therefore represent a more complex, hybrid type of oxide-rich Mn mineralisation (mainly bixbyitic) within massive hematite iron ore. In terms of gangue mineralogy, the ores share some close similarities through the omnipresence of barite, and the abundance of alkalirich silicate minerals. Eastern Belt ores contain abundant albite and serandite whereas the main alkali-rich phase in Western Belt ores is the mineral ephesite. In both cases, Na contents are therefore high at several wt% levels registered in selected samples. The afore-mentioned alkali enrichments have been variously reported for both these deposit types. The occurrence of high alkalis cannot be explained through classic residual or aqueous supergene systems of ore formation, as proposed in prevailing genetic models in the literature. Together with the detection of halogens such as F and Br through SEM-EDS analyses of ore from both belts, the alkali enrichments suggest possible hydrothermal processes of ore formation involving circulation of metalliferous sodic brines. Selected textural evidence from samples from both ore belts lends support to fluid-related models and allow the proposal for a common hydrothermal-replacement model to have been responsible for ore formation across the broader Maremane Dome region.
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Date Issued: 2020

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A Comparative Study of Bootstrapping Techniques for Inventory Control

- Frederick, Lauren

Authors: Frederick, Lauren
Date: 2020
Subjects: Computer bootstrapping -- Inventory control
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10948/48335 , vital:40849
Description: Setting correct inventory levels is an important business consideration in order to minimise inventory investment while at the same time ensuring sufficient inventory levels to meet customer demand. Inventory management has a significant impact on both financial and customer service aspects of a business. Selecting appropriate inventory levels requires that products’ lead time demand be accurately estimated in order to calculate the reorder point. The purpose of this study was to empirically determine whether bootstrapping methods used to estimate the lead time demand distribution and reorder point calculation could match or even outperform a standard parametric approach. The two bootstrapping methods compared in this research included variations of those presented by Bookbinder and Lordahl [1989] and do Rego and de Mesquita [2015]. These were compared to the standard parametric approach common in practice which makes use of the Normal distribution for modelling lead time demand. The three reorder point calculation methods were each incorporated into the inventory policy simulations using data supplied by a South African automotive spare parts business. The simulations covered a period of twelve months and were repeated for multiple service levels ranging from 70 to 99 percent. Results of the simulations were compared at a high level as well as for groups of items identified using segmentation techniques which considered different item demand and lead time characteristics. Key findings were that the Normal approximation method was far superior in terms of the service level metric, while the variation of the Bookbinder and Lordahl [1989] method adopted in this study presented possible cost benefits at lower service levels.
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Date Issued: 2020

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A comparative study of the tax measures for persons with disabilities in South Africa with those of Canada and the Republic of Ireland

- Currie, Natasha

Authors: Currie, Natasha
Date: 2020
Subjects: People with disabilities -- Taxation -- South Africa , People with disabilities -- Taxation -- Law and legislation -- South Africa , People with disabilities -- Taxation -- Canada , People with disabilities -- Taxation -- Law and legislation -- Ireland , People with disabilities -- Taxation -- Ireland
Language: English
Type: text , Thesis , Masters , MCom
Identifier: http://hdl.handle.net/10962/170746 , vital:41956
Description: Literature indicates that tax relief measures for persons with disabilities are important as they align with the principle of equity in the allocation of the tax burden. They are a government intervention that assists in decreasing the financial burden of medical care for persons with disabilities. The right of persons with disabilities to an adequate standard of living is contained in the landmark Convention on the Rights of Persons with Disabilities and Optional Protocol, a treaty of the United Nations, which South Africa ratified in 2007. The objective of the research was to provide a comparative study of tax relief measures for persons with disabilities in South Africa with those of Canada and the Republic of Ireland, with a view to identifying potential areas for improvement in South Africa. The requisite information was primarily collected through an extensive analysis of the tax legislation in the jurisdictions. The research found that tax relief measures for persons with disabilities and their families in South Africa are limited when compared with those of Canada and the Republic of Ireland. The comparative study identifies a number of potential tax relief measures for implementation in South Africa.
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Date Issued: 2020

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A comparison between the responsiveness of selected physiological and subjective mental workload indicators during real-world driving scenarios

- Schmidtke, Nadia-Jasmine

Authors: Schmidtke, Nadia-Jasmine
Date: 2020
Subjects: Automobile driving -- Physiological aspects , Automobile driving -- Psychological aspects , Automobile drivers -- Health and hygiene , Mental fatigue , Mental work -- Case studies
Language: English
Type: text , Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10962/148115 , vital:38711
Description: Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended.
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Date Issued: 2020

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