7490 research outputs found
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Investigation of control methods applied to the doubly fed induction generator
Full text linkGiven the depletion and environmental impact associated with the use of coal or other natural gases for purposes of producing power, the demand of electricity has grown and the need for use of renewables as an alternative source of energy has also received great attention. Various renewable sources exist for producing power and these sources include photovoltaic system, thermal energy, hydro-electric power, and wind energy etc. However, electricity generation from wind has dominated the engineering field, particularly the renewable energy space. Nowadays, a large proportion of renewable electrical power is coming from wind power plants either from onshore or offshore. The hybrid connection of renewable systems with low voltage, medium, or high voltage electrical network may have impact into the operation of the network and can have dynamic effect into the overall power system performance. The rotor speed changes of the turbine because of change in wind may results in changes in grid voltage and frequency. Therefore, it is imperative to comprehensively examine and evaluate the use of wind energy sources into the electrical grid. In the past decade, the wind turbines with slip-ring induction generator commonly known as dual fed induction generator has drawn attention and provides an alternative to the use of traditional variable speed generators due to it having two circuits. The stator flux orientation in the direct axis, results for the equal magnitude of stator and quadrature voltages. The transformed direct current rotor components are utilized for the control of machine output powers, flux and torque. The switching signals for the converter are produced using the pulse width modulation (PWM). PWM is widely used as an alternative for enabling the control of the doubly fed induction generator (DFIG). In this dissertation, conventional proportional integral controller (PI), second order active disturbance rejection controller (ADRC), conventional siding mode controller (SMC) and Fuzzy-PI controller were modelled and simulated on MATLAB/Simulink only. The proposed control methods were investigated and evaluated in terms of the steady state error, steady state ripple and ripple overshoot at both low and high speeds. From the simulation results, fuzzy-PI controller exhibited the overall best results, yielding steady state ripple superiority of above 90%. However, it was observed that the fuzzy-PI controller has a slow response time, and that the algorithm has a high computational burden, thereby making iterative tuning a complex task when compared to other controllers.Thesis (MEng) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 202
The emergence of privately managed terminals within selected ports in Africa: their effectiveness and shortfalls
Full text linkThe study examines the rise of privately managed terminals within selected African ports, analysing their effectiveness and shortcomings. A qualitative methodology was employed, combining thematic analysis of interview data with an extensive literature review. This approach explored the transition of port management from public to private entities in regions such as Southern, Western, North and East Africa. These public entities demonstrated a lack of capacity, expertise and technological advancement to run state of the art ports in order to benchmark themselves against the best in the world. The private sector deployed lot of capital and expertise to turn the fortunes around. Findings reveal that privatisation has significantly improved port operations, infrastructure, and efficiency by leveraging private sector investment and technological advancement. However, challenges such as insufficient peripheral infrastructure, political interference, and labour concerns persist, hampering the full potential of private participation. Notable examples include Maputo and Tangier Med, which showcased successful integration of private operators and public cooperation, while others, such as Durban, grapple with systemic inefficiencies despite privatisation efforts which are contested at the courts. The longer that case takes, the longer it will take to privatise. The study underscores the need for a holistic and implementable framework that aligns port operations with national socio-economic goals, ensuring equitable benefits for all stakeholders such as increase traffic, increase government taxes, competitive advantage, highly trained workforce and improved world ranking of the port, amongst other benefits. Future studies should address long-term socio-environmental impacts and optimising public-private partnerships in the African maritime sector.Thesis (MMM) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Assessing the challenges encountered by South African fisheries in pursuit of blue economy strategic objectives
Full text linkThis study investigates the challenges encountered by South African fisheries in their pursuit of Blue Economy strategic objectives, focusing on sustainable development, economic resilience, and marine conservation. South Africa’s fisheries sector is integral to the national economy and the livelihoods of coastal communities. However, it faces significant challenges that hinder its contribution to the Blue Economy. Through qualitative analysis in the form of interviews and document analysis, the study identifies key issues, including overfishing, illegal, unreported, and unregulated (IUU) fishing, limited market access, inadequate capacity building, and insufficient community involvement. The study highlights the need for ecosystem-based management practices, enhanced monitoring and enforcement mechanisms, and robust regional cooperation to combat IUU fishing effectively. Furthermore, it underscores the importance of capacity building and community engagement, advocating for initiatives that empower small-scale fishers and promote co-management systems that integrate local knowledge with regulatory oversight. The findings also emphasize improving market access and economic opportunities for fishers through infrastructure development, sustainable certification, and financial support. Recommendations provide a roadmap for achieving a sustainable fisheries sector that aligns with Blue Economy principles, balancing economic growth with environmental protection and social equity. This study contributes to the broader discourse on sustainable fisheries management by offering insights and actionable strategies that policymakers, industry stakeholders, and community leaders can use to address current challenges. Ultimately, the research advocates for a more inclusive, resilient, and sustainable approach to managing South Africa’s marine resources, highlighting a model that could serve as a reference for other nations pursuing Blue Economy objectives.Thesis (MMM) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Exploring Indigenous and local knowledge systems in estuarine management
Full text linkThis study explores the Indigenous and Local Knowledge Systems (ILKS) within the Sundays River Estuary (SRE) and how these knowledge systems play vital roles in estuarine management in South Africa. ILKSs are neglected, and much of this knowledge has yet to be identified or has been undervalued. Despite acknowledging different knowledge systems and stakeholders, there is little to no integration of ILKS in current estuary management in South Africa. Communities living around estuaries are excluded from decision-making and natural resource management, focusing mostly on ecological studies, sustainability, and conservation. There is, however, a growing recognition of the importance of incorporating ILKS alongside scientific knowledge, which is crucial to enhancing our understanding and decision-making processes in complex socioecological systems. This study uses social justice and transformative research paradigms to bridge this gap by exploring ILKS in the SRE, focusing on culturally significant areas through participatory community mapping (PCM) and transect walks/walking journeys. Through participatory methods, coresearchers involved in this study (Colchester and Cannonville communities) have the platform to define their significance (cultural values) and share culturally significant areas in the SRE area. This study highlights overlapping uses of the SRE for spiritual and cultural needs, recreation, livelihoods, learning and nature conservation. These diverse uses highlight the need for more inclusive management frameworks that encourage co-management with ILK holders to support sustainable estuarine management practices.Thesis (MA) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Exploring data governance to enhance operations management in the Eastern Cape Department of Transport
Full text linkThe study explored data governance to enhance operations management in the Eastern Cape Department of Transport (EC-DoT). The motivation for this research was the EC-DoT's failure to meet its oversight responsibilities in data management, leading to consecutive adverse audit outcomes. The study used a qualitative research method and adopted an inductive approach to understand the nature and the extent of the research problem. Semi-structured interviews were conducted through a purposive sampling strategy that targeted EC-DoT leadership and management. Out of 30 sampled participants, 19 participants were interviewed thus a achieving a 63% participation rate for the study. Data was analysed and reported using reflective thematic analysis aligned with the research objectives. The study found that reliable data is crucial for achieving operational objectives, and poor data quality hinders decision-making and customer service. Inconsistencies in data management, such as the lack of a data governance guideline and fragmented data systems, were identified as major challenges. The study also highlighted the lack of alignment of national policies, guidelines, and standards, which poses significant challenges to achieving data legitimacy and impedes citizens' rights to access information. Institutional arrangements for data governance were found to be inadequate, with a need for enhanced assurance systems and collaborative information sharing. The study found that reliable data is crucial for achieving operational objectives, and poor data quality hinders decision-making and customer service. Inconsistencies in data management, such as the lack of a data governance guideline and fragmented data systems, were identified as major challenges. The study also highlighted the lack of alignment of national policies, guidelines, and standards, which poses significant challenges to achieving data legitimacy and impedes citizens' rights to access information. Institutional arrangements for data governance were found to be inadequate, with a need for enhanced assurance systems and collaborative information sharing. In addition to proposing a guideline for effective data management, this study recognizes the need for leadership support to drive the desired culture within the EC-DoT. Leadership support is essential for fostering a culture that values data governance. The recommendations are coupled with a change management framework to ensure successful implementation and sustainability.Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 202
The effectiveness of fiscal and monetary policies towards addressing output gaps in South Africa
Full text linkThe study examined fiscal and monetary policies' effectiveness in addressing the output gap in South Africa. The study used the HP filter formula on EViews to calculate the output gap values. Fiscal policy was measured by two proxies, government expenditure and government revenue, while monetary policy was also proxied by two variables: prime lending rate and money supply. The study employed two research techniques, NLADRL and SVAR, using data from the period 1980 to 2021. The theories that underpinned the study are Keynesian, monetarist, and business cycles. The NLARDL results show the countercyclical nature of fiscal policy via government expenditure and the positive cycle of government expenditure that exhibited a negative relationship and is statistically significant. However, in the short term, the positive cycle of government expenditure exhibited a negative relationship and are statistically significant association with the output gap, while the monetary policy, via the prime lending rate, exhibits a procyclical relationship. There is a positive relationship between the prime lending rate and the output gap, while the negative cycle of the prime lending rate that is significant statistically at 1 percent, thus, the positive cycle of the prime lending rate p-value 0.85 is statistically insignificant. The variance decomposition of the output gap variables in the SVAR analysis reveals significant differences in how the explanatory variables respond to shocks. Overall, the prime lending rate emerges as the most impactful shock affecting the South African economy during recessionary periods. Given the outcomes of the study showing that both the fiscal and monetary policies are not effective as opt to be, the study then suggest that structural reforms should be considered in South Africa and the matter of structural adjustment are discussed under the chapter of literature review. The study concludes that whilst both fiscal and monetary policies are essential tools to address output gaps in South Africa, structural constraints must be addressed. The study suggests that there is an urgent need for the implementation of structural reforms to sustain economic growth in South Africa. It is recommended that South African policymakers pay special attention to the structural constraints that continue to neutralise the effect of both fiscal and monetary policies in South Africa.Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Investigating the use of risk management in minimising cybersecurity threats within a South African maritime border in Gqeberha
Full text linkThe emergence of the Fourth Industrial Revolution has transformed information technology and manufacturing. It has affected many sectors, including the maritime industry systems. The maritime freight-forwarding sector provides 70% of trade value and transports around 80 to 90% of all commodities and products worldwide, making it the backbone of international trade. The advancement in technology comes with many benefits for the maritime industry, including the progression of the technical structure of ships through the implementation of integration, digitalisation and automation of systems. However, apart from the opportunities presented by technology developments within the maritime industry, technology has also provided opportunities for cyber-crimes, making the sector vulnerable to cyber attacks that are similar to other critical infrastructures which are connected. The primary objective of this study is to investigate the use of risk management in minimising cyber security threats in the South African Maritime Border in Gqeberha. The study follows a qualitative approach where participants within maritime cyber security were interviewed. The data collected was analysed using thematic analysis. Ten people participated. The results highlighted why cyber security is important, linking to the protection of confidential information, the protection of resources from cyber-attacks as well as the reduction of financial loss. Several recommendations were put forward, including - but not limited to - the need for all personnel working within maritime industry cyber security to undergo ongoing training because technology advances continuously.Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Temas en tendense in die poësie van Clinton v. du Plessis
Full text linkThe aim of this study is to explore themes and trends in the poetry of Clinton V. du Plessis, with specific focus on selected texts. Du Plessis, a coloured Afrikaans poet, is known for his disapproval of the Afrikaans mainstream publishing industry, and his critical attitude towards the Afrikaans literary canon. This positioning serves as an essential starting point for understanding his work. His debut collection, Geloofsbelydenis van ’n kluisenaar, was published by Perskor in 1984. His self-publications include Flitse (2012), Rangeer (2013), Woorde roes in die water (2014), Verslag (2019), 60 op 60 (2022) and Kaartjies, asseblief (2024). Du Plessis states that a sense of estrangement set in after his debut with Perskor. He reveals to Pearce (2012) that he decided to publish his own work due to the maintenance of a “master narrative” by the Afrikaans literary establishment. He began to self-publish. Nowadays, he posts his poems on Facebook, a social media platform. This shift has gradually led to a movement away from his marginal status. In an interview with Janse Van Rensburg (2018), he confesses that an outsider status holds its own appeal for him, but that it will become increasingly difficult to maintain. Despite his status as a marginal figure, he has crossed the threshold of the canon four times. These paradoxes in Du Plessis’ career cannot be overlooked. While he deliberately adopted the role of a marginal figure, he has received increasing recognition for his poetry over the past decade, including awards, exposure to a broader readership on social media, as well as publications with mainstream publishers. This context creates a canvas on which the themes and trends in Du Plessis’ poetry will be explored.Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 202
Stakeholder engagement and sustainable tourism development in the greater Taung Local Municipal area, North-West Province
Full text linkThe global importance of sustainable tourism development as a foundation for economic growth, poverty reduction and employment cannot be over-emphasised, and this is not an exception for the North-West Province of South Africa. Sustainable tourism development is a multi-dimensional phenomenon which needs the involvement of all stakeholders to be a success. This study aims to explore and understand the role of stakeholder engagement on sustainable tourism development in the Greater Taung Local Municipality area. Applying a qualitative research approach under constructivism philosophy and exploratory design, data was collected using open-ended interview schedule. To effectively analyse data, the study adopted thematic approach which was achieved through qualitative techniques which included word cloud, tree maps, cluster analysis, hierarchy charts and word trees. The findings of the study showed that stakeholder engagement is largely dependent on the ability to effectively coordinate relevant stakeholders which is the main responsibility of government. Further findings of the study indicate that given the nature of development and diversity of the tourism industry, stakeholder identification cannot be a once off exercise performed by government alone. While government holds the responsibility of coordination, it is important to ensure that the process of stakeholder identification is as inclusive as possible and most importantly be guided by a set of stakeholder’s identification criteria. There is a need to also ensure that stakeholders are contently engaging. Findings also emphasise the importance of ensuring effective functionality of all formal structures within the tourism sector, the umbrella body and all other forums and stakeholders. These must be well organised, which requires active involvement and participation amongst all stakeholders. To successfully achieve this, various sustainability enablers such as technology, communication, information sharing, responsiveness, marketing, financing and education are important. Most importantly, there is a need for institutionalisation of innovation, research, monitoring and evaluation as the basis for the achievement of stakeholder engagement and sustainable tourism development. The study finally developed a stakeholder engagement and sustainable tourism development framework as a major contribution in the field of tourism.Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Factors influencing performance and productivity at the port of Ngqura container terminal
Full text linkPort performance and productivity are critical determinants of competitiveness in the global shipping industry. This study evaluates the factors influencing the performance and productivity of the Port of Ngqura Container Terminal utilising a qualitative systematic review approach. A total of 30 journal articles and additional industry reports, benchmarking studies, and policy documents published between 2014 and 2023 were analysed to assess operational inefficiencies, infrastructure limitations, and connectivity challenges. Guided by the Seaport Performance Theory (SPT) framework, the study identifies three strategic interventions for improving port performance: Infrastructure Maintenance, Technology Integration, and Human Capital Development. The thematic findings highlight the importance of adopting policies that promote resilience strategies, such as contingency planning for operational disruptions caused by extreme weather conditions or other unforeseen events. These interventions, aim to improve Key Performance Indicators (KPIs), maintain productivity during disruptions, and optimise resource allocation to improve overall port efficiency and competitiveness.Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202