A risk management model for commercial property development and investment in Ghana
- Authors: Asianoah, Rexford Kofi
- Date: 2023-04
- Subjects: Risk management , Commercial real estate , Investment -- Ghana
- Language: English
- Type: Doctoral's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60493 , vital:65633
- Description: Commercial property development and investment provide many benefits to individuals and governments around the globe; these include the generation of income for investors, employment, tax revenues, and contributions to a country‘s GDP. Yet commercial property development and investment projects involve construction, economic and management risks. A lack of effective risk assessment and management tools may lead to developers and investors incurring losses. To curtail such losses, this study sought to create a credible management model that can be used to assess and manage risks in Ghana‘s commercial property development and investment industry. An extensive literature review was done, covering all 12 identified study constructs: real estate trends and cycle, construction project management, outside advice/mentorship, spatial development, strategic factors, business management skills, PMBOK, PESTEL analysis, general management skills, governance structures, financial feasibility, professional feasibility, and risk management. Each construct was defined and operationalised. A positivistic philosophical approach was used, and quantitative approach was used to solicit data from the main respondents through the distribution of questionnaires to the target population sample. CB-SEM and SPSS version 24 were used to analyse data, SEM to test the positive relationships hypothesised between the identified variables and SPSS to analyse the demographic data. The major findings are that there is a lack of financial and professional feasibility analysis among respondents along the following factors: the PMBOK, real estate trends and cycles, general management, business management, strategic factors, spatial development, and PESTEL analysis. It was found that these factors have positive and favourable influences on CPDI projects. The study recommends that developers and investors do financial and professional feasibility studies before they embark on projects. This could improve project viability in commercial property development and investment. The study has contributed to the body of knowledge in CPDI sector by developing a new risk assessment/risk management model. , Thesis (PhD) -- Faculty of Engineering Built Environment and Technology, School of the built Environment, 2023
- Full Text:
- Date Issued: 2023-04
- Authors: Asianoah, Rexford Kofi
- Date: 2023-04
- Subjects: Risk management , Commercial real estate , Investment -- Ghana
- Language: English
- Type: Doctoral's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60493 , vital:65633
- Description: Commercial property development and investment provide many benefits to individuals and governments around the globe; these include the generation of income for investors, employment, tax revenues, and contributions to a country‘s GDP. Yet commercial property development and investment projects involve construction, economic and management risks. A lack of effective risk assessment and management tools may lead to developers and investors incurring losses. To curtail such losses, this study sought to create a credible management model that can be used to assess and manage risks in Ghana‘s commercial property development and investment industry. An extensive literature review was done, covering all 12 identified study constructs: real estate trends and cycle, construction project management, outside advice/mentorship, spatial development, strategic factors, business management skills, PMBOK, PESTEL analysis, general management skills, governance structures, financial feasibility, professional feasibility, and risk management. Each construct was defined and operationalised. A positivistic philosophical approach was used, and quantitative approach was used to solicit data from the main respondents through the distribution of questionnaires to the target population sample. CB-SEM and SPSS version 24 were used to analyse data, SEM to test the positive relationships hypothesised between the identified variables and SPSS to analyse the demographic data. The major findings are that there is a lack of financial and professional feasibility analysis among respondents along the following factors: the PMBOK, real estate trends and cycles, general management, business management, strategic factors, spatial development, and PESTEL analysis. It was found that these factors have positive and favourable influences on CPDI projects. The study recommends that developers and investors do financial and professional feasibility studies before they embark on projects. This could improve project viability in commercial property development and investment. The study has contributed to the body of knowledge in CPDI sector by developing a new risk assessment/risk management model. , Thesis (PhD) -- Faculty of Engineering Built Environment and Technology, School of the built Environment, 2023
- Full Text:
- Date Issued: 2023-04
Inner-city regeneration in South Africa : a property development approach
- Authors: Chidzambwa, Overt
- Date: 2023-04
- Subjects: Regeneration -- South Africa , Real estate development
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60578 , vital:65894
- Description: Worldwide, the topic of inner-city decay and regeneration continues to attract a lot of attention from various parties and organisations. This is largely due to the fact that Central Business Districts (CBDs) remain the heartbeat of any city’s economic, social and political vibrancy. It therefore remains an ongoing process for the government and private stakeholders to keep on devising strategies aimed at revitalising the inner-city. The problem of urban decay is however experienced more in the developing third world and is characterised by high unemployment rates, high crime rates, depopulation, desolate-looking landscapes, abandonment of buildings, split families amongst others. Urban decay does not have one single cause, but rather a combination of many, including poor urban planning, redlining, poverty, suburbanization, and racial discrimination. These factors have resulted in urban sprawl as property owners preferred to migrate from the increasingly toxic social and economic environment that now became of the inner-city. The study seeks to investigate the current state of urban decay in South African CBDs with a case study of Gqeberha metro city, it also investigates current efforts and measures in place for regeneration and lastly, recommendations that have been put and continue to be put in place for inner-city regeneration. The state of inner-city infrastructure, property development finance options, town planning requirements and regulations and the investment case are other factors that have been investigated. Various other aspects of inner-city dynamics in the context of property development have been explored with findings from extensive literature review and structured interviews enabling the researcher to come up with recommendations for sustainable inner-city regeneration. , Thesis (MSBE) --Faculty of Engineering Built Environment and Information Technology, School of Built Environment and Civil Engineering, 2023
- Full Text:
- Date Issued: 2023-04
- Authors: Chidzambwa, Overt
- Date: 2023-04
- Subjects: Regeneration -- South Africa , Real estate development
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/60578 , vital:65894
- Description: Worldwide, the topic of inner-city decay and regeneration continues to attract a lot of attention from various parties and organisations. This is largely due to the fact that Central Business Districts (CBDs) remain the heartbeat of any city’s economic, social and political vibrancy. It therefore remains an ongoing process for the government and private stakeholders to keep on devising strategies aimed at revitalising the inner-city. The problem of urban decay is however experienced more in the developing third world and is characterised by high unemployment rates, high crime rates, depopulation, desolate-looking landscapes, abandonment of buildings, split families amongst others. Urban decay does not have one single cause, but rather a combination of many, including poor urban planning, redlining, poverty, suburbanization, and racial discrimination. These factors have resulted in urban sprawl as property owners preferred to migrate from the increasingly toxic social and economic environment that now became of the inner-city. The study seeks to investigate the current state of urban decay in South African CBDs with a case study of Gqeberha metro city, it also investigates current efforts and measures in place for regeneration and lastly, recommendations that have been put and continue to be put in place for inner-city regeneration. The state of inner-city infrastructure, property development finance options, town planning requirements and regulations and the investment case are other factors that have been investigated. Various other aspects of inner-city dynamics in the context of property development have been explored with findings from extensive literature review and structured interviews enabling the researcher to come up with recommendations for sustainable inner-city regeneration. , Thesis (MSBE) --Faculty of Engineering Built Environment and Information Technology, School of Built Environment and Civil Engineering, 2023
- Full Text:
- Date Issued: 2023-04
A framework for ethical sourcing of construction materials
- Authors: Ibrahim, Kabir
- Date: 2019
- Subjects: Construction industry -- Environmental aspects -- Nigeria , Building materials -- Environmental aspects -- Nigeria Building -- Environmental aspects -- Nigeria Environmental protection -- Nigeria Conservation of natural resources -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42140 , vital:36629
- Description: Climate change and a speedily depreciating ecosystem are global challenges. These challenges are, in the main, attributed to activities in the construction industry, which relies heavily on the environment to provide materials. Studies show that the impact in developing countries is worse, due to the low level of awareness. Consequently, there is a dearth of research-based evidence on the ethics of sourcing of materials. This research aimed at changing that by investigating the ethics of materials sourcing in Nigeria. Epistemologically, the research is subjective and paradigmatically phenomenological. The methods used for data collection include a comprehensive literature review, collection of archival records, empirical studies of sixteen organisations that are involved in materials sourcing, transportation and production of eight construction materials across the six geo-political zones in Nigeria, that were purposefully selected. The findings reveal that the majority of the processes employed to source, transport and produce materials for the construction industry are not ethical environmentally due to their contribution to air pollution, water pollution, noise pollution and vibration, landscape damage, harm to flora and fauna and waste production. Furthermore, the study found that the majority of the organisations studied, do not produce sustainability reports for their operations. The study developed a framework for ethical sourcing of construction materials. The study recommends that organisations should utilise the framework developed in this study to enhance their sustainability practices.
- Full Text:
- Date Issued: 2019
- Authors: Ibrahim, Kabir
- Date: 2019
- Subjects: Construction industry -- Environmental aspects -- Nigeria , Building materials -- Environmental aspects -- Nigeria Building -- Environmental aspects -- Nigeria Environmental protection -- Nigeria Conservation of natural resources -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42140 , vital:36629
- Description: Climate change and a speedily depreciating ecosystem are global challenges. These challenges are, in the main, attributed to activities in the construction industry, which relies heavily on the environment to provide materials. Studies show that the impact in developing countries is worse, due to the low level of awareness. Consequently, there is a dearth of research-based evidence on the ethics of sourcing of materials. This research aimed at changing that by investigating the ethics of materials sourcing in Nigeria. Epistemologically, the research is subjective and paradigmatically phenomenological. The methods used for data collection include a comprehensive literature review, collection of archival records, empirical studies of sixteen organisations that are involved in materials sourcing, transportation and production of eight construction materials across the six geo-political zones in Nigeria, that were purposefully selected. The findings reveal that the majority of the processes employed to source, transport and produce materials for the construction industry are not ethical environmentally due to their contribution to air pollution, water pollution, noise pollution and vibration, landscape damage, harm to flora and fauna and waste production. Furthermore, the study found that the majority of the organisations studied, do not produce sustainability reports for their operations. The study developed a framework for ethical sourcing of construction materials. The study recommends that organisations should utilise the framework developed in this study to enhance their sustainability practices.
- Full Text:
- Date Issued: 2019
A framework to implement information security awareness, education and training within the Limpopo economic development agency group
- Authors: Mokobane, Ntsewa Benjamin
- Date: 2019
- Subjects: Computer security , Computer networks -- Security measures Data protection
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/42063 , vital:36622
- Description: Cybersecurity awareness, education and training of employees is key in reducing and preventing cyber-attack opportunities. The ignorance and/or lack of understanding of employees about the information security risks around them might expose the LEDA Group to cyber-attacks. This led to the problem that the level of awareness of employees regarding information security was not known. The implication of this not knowing was that an argument for the nature of an intervention to ensure awareness, as well as to educate and train employees regarding information security was not possible. The aim of this treatise was to develop a framework as an effective guideline for the implementation of cybersecurity awareness, education and training of employees. In the study, the LEDA Group employees were surveyed to determine their cybersecurity knowledge gap. An online questionnaire was randomly sent to 314 LEDA Group employees. The survey was voluntary and confidential. One hundred and thirty seven (137) employees completed the survey. The results of the survey were analysed to determine the gap between the current cybersecurity knowledge of the LEDA Group employees and state-of-the-art cybersecurity knowledge. The gap was used in the development of the framework for the implementation of the cybersecurity awareness, education and training (F-CSAET). Central to F-CSAET is the governance principles guided by best practices such as King IV, COBIT5, ISO27001, ISO27005, ISO27008 and ISO27032 and the compliance requirements to POPIA, the Copyright Act and the Cybercrimes and Cybersecurity Bill. The F-CSAET has six steps, namely Assess, Analyse, Create, Plan, Implement and Reinforce. The framework was evaluated for applicability by the team called the cyber security interest team, which was established specifically for the purpose of the F-CSAET.
- Full Text:
- Date Issued: 2019
- Authors: Mokobane, Ntsewa Benjamin
- Date: 2019
- Subjects: Computer security , Computer networks -- Security measures Data protection
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/42063 , vital:36622
- Description: Cybersecurity awareness, education and training of employees is key in reducing and preventing cyber-attack opportunities. The ignorance and/or lack of understanding of employees about the information security risks around them might expose the LEDA Group to cyber-attacks. This led to the problem that the level of awareness of employees regarding information security was not known. The implication of this not knowing was that an argument for the nature of an intervention to ensure awareness, as well as to educate and train employees regarding information security was not possible. The aim of this treatise was to develop a framework as an effective guideline for the implementation of cybersecurity awareness, education and training of employees. In the study, the LEDA Group employees were surveyed to determine their cybersecurity knowledge gap. An online questionnaire was randomly sent to 314 LEDA Group employees. The survey was voluntary and confidential. One hundred and thirty seven (137) employees completed the survey. The results of the survey were analysed to determine the gap between the current cybersecurity knowledge of the LEDA Group employees and state-of-the-art cybersecurity knowledge. The gap was used in the development of the framework for the implementation of the cybersecurity awareness, education and training (F-CSAET). Central to F-CSAET is the governance principles guided by best practices such as King IV, COBIT5, ISO27001, ISO27005, ISO27008 and ISO27032 and the compliance requirements to POPIA, the Copyright Act and the Cybercrimes and Cybersecurity Bill. The F-CSAET has six steps, namely Assess, Analyse, Create, Plan, Implement and Reinforce. The framework was evaluated for applicability by the team called the cyber security interest team, which was established specifically for the purpose of the F-CSAET.
- Full Text:
- Date Issued: 2019
A model for the alignment of information security requirements within South African small, medium and micro enterprises
- Authors: Speckman, Timothy Harambee
- Date: 2019
- Subjects: Computer security -- Management , Data protection -- Management Small business -- South Africa Knowledge management
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/44012 , vital:37092
- Description: Small, medium and micro enterprises (SMMEs) are reported to be the hope of the economy in many developing countries, such as South Africa (SA). The unique characteristics of SMMEs such as their ability to evolve rapidly, and to employ larger labour forces as they grow, make these enterprises valuable to the SA economy, in which poverty and unemployment rates are alarmingly high. Like most modern enterprises, SA SMMEs make use of information and communication technology (ICT) systems - as a vehicle to store, transmit and process information, which is an asset that is critical to their business operations. Thus, the vulnerabilities of these ICT systems need to be addressed, in order to protect the information assets of enterprises. However, SMMEs are known to only implement measures to protect their information assets on an ad hoc basis and frequently as reactive measures to information security incidents. This can be attributed to the fact that most of these enterprises lack the ability to establish their unique information security requirements. Information security requirements are a measure of the level of security needed to adequately protect the information assets of an enterprise. Furthermore, it is reported that information security best practices and standards, which provide guidance on information security, are too complex for SA SMMEs to implement and for SMMEs to use for establishing their unique information security requirements.
- Full Text:
- Date Issued: 2019
- Authors: Speckman, Timothy Harambee
- Date: 2019
- Subjects: Computer security -- Management , Data protection -- Management Small business -- South Africa Knowledge management
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/44012 , vital:37092
- Description: Small, medium and micro enterprises (SMMEs) are reported to be the hope of the economy in many developing countries, such as South Africa (SA). The unique characteristics of SMMEs such as their ability to evolve rapidly, and to employ larger labour forces as they grow, make these enterprises valuable to the SA economy, in which poverty and unemployment rates are alarmingly high. Like most modern enterprises, SA SMMEs make use of information and communication technology (ICT) systems - as a vehicle to store, transmit and process information, which is an asset that is critical to their business operations. Thus, the vulnerabilities of these ICT systems need to be addressed, in order to protect the information assets of enterprises. However, SMMEs are known to only implement measures to protect their information assets on an ad hoc basis and frequently as reactive measures to information security incidents. This can be attributed to the fact that most of these enterprises lack the ability to establish their unique information security requirements. Information security requirements are a measure of the level of security needed to adequately protect the information assets of an enterprise. Furthermore, it is reported that information security best practices and standards, which provide guidance on information security, are too complex for SA SMMEs to implement and for SMMEs to use for establishing their unique information security requirements.
- Full Text:
- Date Issued: 2019
A model for using learners' online behaviour to inform differentiated instructional design in MOODLE
- Authors: Leppan, Ronald George
- Date: 2019
- Subjects: Cyberspace -- Psychological aspects , Web applications in libraries Moodle Special education -- Computer programs Computer-assisted instruction -- Computer programs Open source software
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40393 , vital:36155
- Description: This thesis proposes a learning analytics-based process model, derived from a web analytics process, which aims to build a learner profile of attributes from Moodle log files that can be used for differentiated instructional design in Moodle. Commercial websites are rife with examples of personalisation based on web analytics, while the personalisation of online learning has not yet gained such widespread adoption. Several Instructional Design Models recommend that, in addition to taking prior knowledge and learning outcomes into account, instruction should also be informed by learner attributes. Learning design choices should be made based on unique learner attributes that influence their learning processes. Learner attributes are generally derived from well-known learning styles and associated learning style questionnaires. However, there are some criticisms of learning style theories and the use of questionnaires to create a learner profile. Attributes that can be inferred from learners’ online behaviour could provide a more dynamic learner profile. Education institutions are increasingly using Learning Management Systems, such as Moodle, to deliver and manage online learning. Moodle is not designed to create a learner profile or provide differentiated instruction. However, the abundant data generated by learners accessing course material presented in Moodle provides an opportunity for educators to build such a dynamic learner profile. Individual learner profiles can be used by educators who desire to tailor instruction to the needs of their learners. The proposed model was developed and evaluated using an iterative design focused approach that incorporates characteristics of a web analytics process, instructional design models, Learning Management Systems, educational data mining and adaptive education technologies. At each iteration, the model was evaluated using a technical risk and efficacy strategy. This strategy proposes a formative evaluation in an artificial setting. Evaluation criteria used include relevance, consistency, practicality and utility. The contributions of this thesis address the lack of prescriptive guidance on how to analyse learner online behaviours in order to differentiate learning design in Moodle. The theoretical contribution is a model for a dynamic data-driven approach to profile building and a phased differentiated learning design in a Learning Management System. The practical contribution is an evaluation of the expected practicality and utility of learner modelling from Moodle log files and the provision of tailored instruction using standard Moodle tools. The proposed model recommends that educators should define goals, develop Key Performance Indicators (KPI) to measure goal attainment, collect and analyse suitable metrics towards KPIs, test optional alternative hypotheses and implement actionable insights. To enable differentiated instruction, two phases are necessary: learner modelling and differentiated learning design. Both phases rely on the selection of suitable attributes which influence learning processes, and which can be dynamically inferred from online behaviours. In differentiated learning design, the selection/creation and sequencing of Learning Objects are influenced by the learner attributes. In learner modelling, the data sources and data analysis techniques should enable the discovery of the learner attributes that was catered for in the learning design. Educators who follow the steps described in the proposed model will be capable of building a learner profile from Moodle log files that can be used for differentiated instruction based on any learning style theory.
- Full Text:
- Date Issued: 2019
A model for using learners' online behaviour to inform differentiated instructional design in MOODLE
- Authors: Leppan, Ronald George
- Date: 2019
- Subjects: Cyberspace -- Psychological aspects , Web applications in libraries Moodle Special education -- Computer programs Computer-assisted instruction -- Computer programs Open source software
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40393 , vital:36155
- Description: This thesis proposes a learning analytics-based process model, derived from a web analytics process, which aims to build a learner profile of attributes from Moodle log files that can be used for differentiated instructional design in Moodle. Commercial websites are rife with examples of personalisation based on web analytics, while the personalisation of online learning has not yet gained such widespread adoption. Several Instructional Design Models recommend that, in addition to taking prior knowledge and learning outcomes into account, instruction should also be informed by learner attributes. Learning design choices should be made based on unique learner attributes that influence their learning processes. Learner attributes are generally derived from well-known learning styles and associated learning style questionnaires. However, there are some criticisms of learning style theories and the use of questionnaires to create a learner profile. Attributes that can be inferred from learners’ online behaviour could provide a more dynamic learner profile. Education institutions are increasingly using Learning Management Systems, such as Moodle, to deliver and manage online learning. Moodle is not designed to create a learner profile or provide differentiated instruction. However, the abundant data generated by learners accessing course material presented in Moodle provides an opportunity for educators to build such a dynamic learner profile. Individual learner profiles can be used by educators who desire to tailor instruction to the needs of their learners. The proposed model was developed and evaluated using an iterative design focused approach that incorporates characteristics of a web analytics process, instructional design models, Learning Management Systems, educational data mining and adaptive education technologies. At each iteration, the model was evaluated using a technical risk and efficacy strategy. This strategy proposes a formative evaluation in an artificial setting. Evaluation criteria used include relevance, consistency, practicality and utility. The contributions of this thesis address the lack of prescriptive guidance on how to analyse learner online behaviours in order to differentiate learning design in Moodle. The theoretical contribution is a model for a dynamic data-driven approach to profile building and a phased differentiated learning design in a Learning Management System. The practical contribution is an evaluation of the expected practicality and utility of learner modelling from Moodle log files and the provision of tailored instruction using standard Moodle tools. The proposed model recommends that educators should define goals, develop Key Performance Indicators (KPI) to measure goal attainment, collect and analyse suitable metrics towards KPIs, test optional alternative hypotheses and implement actionable insights. To enable differentiated instruction, two phases are necessary: learner modelling and differentiated learning design. Both phases rely on the selection of suitable attributes which influence learning processes, and which can be dynamically inferred from online behaviours. In differentiated learning design, the selection/creation and sequencing of Learning Objects are influenced by the learner attributes. In learner modelling, the data sources and data analysis techniques should enable the discovery of the learner attributes that was catered for in the learning design. Educators who follow the steps described in the proposed model will be capable of building a learner profile from Moodle log files that can be used for differentiated instruction based on any learning style theory.
- Full Text:
- Date Issued: 2019
A monitoring and control system for an accelerated weather test chamber
- Authors: Harvey, Luke Gareth
- Date: 2019
- Subjects: Materials -- Deterioration -- Testing , Motor vehicles -- Testing Motor vehicles -- Automatic control Intelligent control systems
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/40360 , vital:36152
- Description: In the Automotive Sector, weathering tests of components are of paramount importance. The most critical components to the overall comfort and durability of a vehicle are the interior components and thus is important to guarantee the quality of these components. The interior components are generally made of plastic, fabric, leather and various painted components. These components are prone to fading, cracking and distortion which is caused by natural factors such as solar radiation, temperature and moisture. This is known as natural weathering. Over the years many weathering tests have been carried out on automotive components to address critical issues during the design process. Many of these tests are simulated in chambers to mimic real life cycles. Although these accelerated tests provide somewhat accurate results in much shorter periods, natural weathering is still essential as it is uncontrolled and unpredictable. This dissertation looks at the method of a metallic chamber used to carry out weathering tests on automotive components and to simulate the conditions inside a vehicle. It addresses the current state and improvement: accurate tracking, intelligent fuzzy logic control and cloud-based monitoring. Currently weather testing chambers are stationery, which does not allow for maximum exposer to solar radiation. Therefore, a system was designed to allow the weather testing chamber to track the azimuth and elevation of the sun to increase the solar radiation on the components tested, a GPS will achieve this. Currently systems lack remote monitoring. A further shortcoming is the lack of controlling the temperature and humidity inside the chamber for sufficient tests. The use of a fuzzy logic controller was implemented to achieve this. The fuzzy logic was compared to other types of logic controllers. To further IoT integration, two main control devices were used, these control devices were two Arduino Mega’s. One Arduino Mega was used for the intelligent fuzzy logic control and the second for solar tracking. The weathering system and controllers were powered by using solar power. The fuzzy logic controller was tested while tracking the sun and then not tracking the sun. The results obtained were compared and it was seen that the fuzzy logic performed very well in both instances, however, the test with tracking the sun performed better. A second test was performed. The second test was similar to the previously mentioned test, but the fuzzy logic had a set point control. It was concluded that both tests performed as expected as the fuzzy logic controlled the temperature and humidity at the given setpoint, but during the solar tracking test the fuzzy logic control performed the best. The fuzzy logic worked well in general use as well as set point control, both for tracking and non-tracking. The tracking performed better than the non-tracking.
- Full Text:
- Date Issued: 2019
- Authors: Harvey, Luke Gareth
- Date: 2019
- Subjects: Materials -- Deterioration -- Testing , Motor vehicles -- Testing Motor vehicles -- Automatic control Intelligent control systems
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/40360 , vital:36152
- Description: In the Automotive Sector, weathering tests of components are of paramount importance. The most critical components to the overall comfort and durability of a vehicle are the interior components and thus is important to guarantee the quality of these components. The interior components are generally made of plastic, fabric, leather and various painted components. These components are prone to fading, cracking and distortion which is caused by natural factors such as solar radiation, temperature and moisture. This is known as natural weathering. Over the years many weathering tests have been carried out on automotive components to address critical issues during the design process. Many of these tests are simulated in chambers to mimic real life cycles. Although these accelerated tests provide somewhat accurate results in much shorter periods, natural weathering is still essential as it is uncontrolled and unpredictable. This dissertation looks at the method of a metallic chamber used to carry out weathering tests on automotive components and to simulate the conditions inside a vehicle. It addresses the current state and improvement: accurate tracking, intelligent fuzzy logic control and cloud-based monitoring. Currently weather testing chambers are stationery, which does not allow for maximum exposer to solar radiation. Therefore, a system was designed to allow the weather testing chamber to track the azimuth and elevation of the sun to increase the solar radiation on the components tested, a GPS will achieve this. Currently systems lack remote monitoring. A further shortcoming is the lack of controlling the temperature and humidity inside the chamber for sufficient tests. The use of a fuzzy logic controller was implemented to achieve this. The fuzzy logic was compared to other types of logic controllers. To further IoT integration, two main control devices were used, these control devices were two Arduino Mega’s. One Arduino Mega was used for the intelligent fuzzy logic control and the second for solar tracking. The weathering system and controllers were powered by using solar power. The fuzzy logic controller was tested while tracking the sun and then not tracking the sun. The results obtained were compared and it was seen that the fuzzy logic performed very well in both instances, however, the test with tracking the sun performed better. A second test was performed. The second test was similar to the previously mentioned test, but the fuzzy logic had a set point control. It was concluded that both tests performed as expected as the fuzzy logic controlled the temperature and humidity at the given setpoint, but during the solar tracking test the fuzzy logic control performed the best. The fuzzy logic worked well in general use as well as set point control, both for tracking and non-tracking. The tracking performed better than the non-tracking.
- Full Text:
- Date Issued: 2019
A strategy for adopting cloud computing services in small, medium and micro enterprises (SME) in the Nelson Mandela Metropole
- Authors: Sarpong, George
- Date: 2019
- Subjects: Cloud computing , Technological innovations -- Management Information technology -- Management Management information systems New business enterprises -- South Africa -- Nelson Mandela Bay Municipality Small business -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/43567 , vital:36920
- Description: Small, medium and micro enterprises (SMEs) in South Africa continue to form the foundation for growing the economy. Thus, these enterprises have a significant role in to play in helping the country to eliminate poverty and unemployment. In order for these businesses to continue to grow and stay abreast with the changing business landscape, these businesses need to adopt some or other form of technology. One such technology is cloud computing, which is at times referred to as external hosting. Cloud computing is a type of technology that allows any business to operate as if it had a team of dedicated professional information technology (IT) personnel continually checking and monitoring its IT systems. As a result, cloud computing often allows a business to save on costs, improve communication with clients and speed up the transfer of information across the business. Thus, as SMEs often have small or non-existent IT departments, cloud computing offers these business an opportunity to compete with larger corporations without having to compromise on the quality of their service. However, in spite of these benefits, cloud computing still remains something of a novelty to many small businesses that operate in Nelson Mandela Metropole, as these businesses tend to either adopt a small portion of the technology or not to adopt the technology at all. The reasons for not significantly investing in the technology are usually far ranging but are often linked to these businesses not understanding how the service can be best used to help their business to grow. This study includes a description of a strategy that SMEs can follow when adopting cloud computing services as part of their business models. In addition to this, this study includes a discussion on the various benefits and disadvantages that await SMEs that make the decision to invest in the service.
- Full Text:
- Date Issued: 2019
- Authors: Sarpong, George
- Date: 2019
- Subjects: Cloud computing , Technological innovations -- Management Information technology -- Management Management information systems New business enterprises -- South Africa -- Nelson Mandela Bay Municipality Small business -- South Africa -- Management
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/43567 , vital:36920
- Description: Small, medium and micro enterprises (SMEs) in South Africa continue to form the foundation for growing the economy. Thus, these enterprises have a significant role in to play in helping the country to eliminate poverty and unemployment. In order for these businesses to continue to grow and stay abreast with the changing business landscape, these businesses need to adopt some or other form of technology. One such technology is cloud computing, which is at times referred to as external hosting. Cloud computing is a type of technology that allows any business to operate as if it had a team of dedicated professional information technology (IT) personnel continually checking and monitoring its IT systems. As a result, cloud computing often allows a business to save on costs, improve communication with clients and speed up the transfer of information across the business. Thus, as SMEs often have small or non-existent IT departments, cloud computing offers these business an opportunity to compete with larger corporations without having to compromise on the quality of their service. However, in spite of these benefits, cloud computing still remains something of a novelty to many small businesses that operate in Nelson Mandela Metropole, as these businesses tend to either adopt a small portion of the technology or not to adopt the technology at all. The reasons for not significantly investing in the technology are usually far ranging but are often linked to these businesses not understanding how the service can be best used to help their business to grow. This study includes a description of a strategy that SMEs can follow when adopting cloud computing services as part of their business models. In addition to this, this study includes a discussion on the various benefits and disadvantages that await SMEs that make the decision to invest in the service.
- Full Text:
- Date Issued: 2019
A strategy for improving the maturity levels of IT service management in higher education institutions in South Africa
- Authors: Hilmer, Thomas
- Date: 2019
- Subjects: Information technology -- Management , Information technology Education, Higher -- South Africa Education -- Effect of technological innovations on -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40161 , vital:35824
- Description: IT Service Management (ITSM) refers to a set of activities that an organisation can perform to develop, supply, operate, manage and improve information technology related services in order to meet the needs of the business. The interest in ITSM is based on the expectation that applying best practice ITSM processes will result in lower expenses, fewer incidents and improved customer satisfaction. Various standards, frameworks, methodologies and processes have evolved to support this move to a value-driven, service-orientated approach to managing an organisation’s information systems. Between 2007 and 2009, Higher Education Institutions (HEIs) in South Africa benefited from a national project to improve the quality of their IT services through training in ITIL, a best practice ITSM framework. An assessment at the time, however, found that the maturity levels of the ITIL processes implemented after the intervention remained low, and this observation is common in other industries as well. The implementation of industry best practice ITSM frameworks does not always proceed smoothly; they can be costly, have long implementation times, and can be seen as excessively complicated and suited mainly for large organisations. Therefore, it is often challenging for organisations such as HEIs to improve their ITSM process maturity levels. The aim of this study is to develop a strategy that may assist South African HEIs in taking steps to improve their IT Service Management maturity levels. This primary research objective is addressed through a number of secondary research objectives, namely, to understand the challenges that HEIs often encounter when implementing ITSM; to determine the ITSM implementation status at a number of South African HEIs; to determine the various elements and components required to formulate the ITSM strategy; to determine whether alternatives to ITIL are feasible options for HEIs in South Africa; and to validate the proposed strategy by verifying its quality, utility and efficacy. A comprehensive literature review provides information on various ITSM standards, frameworks and methodologies. It also investigates ITSM adoption and implementation by organisations in general, and HEIs in particular, and how modern practices such as DevOps, Agile and Lean relate to ITSM. Thereafter, an online survey is used to determine the status of ITSM maturity levels at South African HEIs, and whether alternatives to ITIL are being used. Expert interviews are used to obtain additional information on what is required to formulate the proposed strategy. The findings from the literature review, survey and expert interviews are used to develop a four-step strategy, which was evaluated for its quality, utility and efficacy through an online assessment by the same experts. This strategy can be considered a useful tool for Higher Education Institutions in South Africa if they wish to increase their levels of IT Service Management maturity. The findings of this study make a substantial contribution to the field of ITSM research at South African Higher Education Institutions.
- Full Text:
- Date Issued: 2019
- Authors: Hilmer, Thomas
- Date: 2019
- Subjects: Information technology -- Management , Information technology Education, Higher -- South Africa Education -- Effect of technological innovations on -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40161 , vital:35824
- Description: IT Service Management (ITSM) refers to a set of activities that an organisation can perform to develop, supply, operate, manage and improve information technology related services in order to meet the needs of the business. The interest in ITSM is based on the expectation that applying best practice ITSM processes will result in lower expenses, fewer incidents and improved customer satisfaction. Various standards, frameworks, methodologies and processes have evolved to support this move to a value-driven, service-orientated approach to managing an organisation’s information systems. Between 2007 and 2009, Higher Education Institutions (HEIs) in South Africa benefited from a national project to improve the quality of their IT services through training in ITIL, a best practice ITSM framework. An assessment at the time, however, found that the maturity levels of the ITIL processes implemented after the intervention remained low, and this observation is common in other industries as well. The implementation of industry best practice ITSM frameworks does not always proceed smoothly; they can be costly, have long implementation times, and can be seen as excessively complicated and suited mainly for large organisations. Therefore, it is often challenging for organisations such as HEIs to improve their ITSM process maturity levels. The aim of this study is to develop a strategy that may assist South African HEIs in taking steps to improve their IT Service Management maturity levels. This primary research objective is addressed through a number of secondary research objectives, namely, to understand the challenges that HEIs often encounter when implementing ITSM; to determine the ITSM implementation status at a number of South African HEIs; to determine the various elements and components required to formulate the ITSM strategy; to determine whether alternatives to ITIL are feasible options for HEIs in South Africa; and to validate the proposed strategy by verifying its quality, utility and efficacy. A comprehensive literature review provides information on various ITSM standards, frameworks and methodologies. It also investigates ITSM adoption and implementation by organisations in general, and HEIs in particular, and how modern practices such as DevOps, Agile and Lean relate to ITSM. Thereafter, an online survey is used to determine the status of ITSM maturity levels at South African HEIs, and whether alternatives to ITIL are being used. Expert interviews are used to obtain additional information on what is required to formulate the proposed strategy. The findings from the literature review, survey and expert interviews are used to develop a four-step strategy, which was evaluated for its quality, utility and efficacy through an online assessment by the same experts. This strategy can be considered a useful tool for Higher Education Institutions in South Africa if they wish to increase their levels of IT Service Management maturity. The findings of this study make a substantial contribution to the field of ITSM research at South African Higher Education Institutions.
- Full Text:
- Date Issued: 2019
A strategy for sustainable ICT development in deep rural environments
- Authors: Medupe, Tsietsi Jacob
- Date: 2019
- Subjects: Information technology , Sustainable development Information technology -- Developing countries Rural development -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41438 , vital:36483
- Description: This study provides a strategy for sustainable Information and Communcation Technology (ICT) development in deep rural environments and describes a case study conducted within the community of the AmaJingqi traditional council. It investigates the sustainability of the ICT services within a rural environments, the income profile and affordability of different members of the community and the strategy formulation model. The study’s main focus is on creating a strategy to be used as a guideline for the successful development and implementation of sustainable ICT development in deep rural environments and on defining ICT Sustainability. Furthermore, the different ICT users are profiled based on affordability and access to services, and deep rural environments are also defined. Moreover, the study describes the complete composition of sustainable ICT. It discusses design science research methodology and the reasons why the method is used is motivated and advanced. The study also outlines various research paradigms and philosophies and a number of research strategies are also discussed. The literature review focuses on various policies and frameworks which have been formulated to advance the universal access of ICT services by rural communities. It also outlines some of the ICT initiatives which have failed and the reasons for the failures and what will be corrected for similar mistakes not to be repeated. The study discusses the concepts of a strategy framework that outlines the theoretical foundation of the strategy formulation model, strategy implementation and control. It also discusses the diagnostics and outlines the various strategy guiding polices. The strategy is validated, expert reviews are solicited and the strategy is revised and finalised.
- Full Text:
- Date Issued: 2019
- Authors: Medupe, Tsietsi Jacob
- Date: 2019
- Subjects: Information technology , Sustainable development Information technology -- Developing countries Rural development -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41438 , vital:36483
- Description: This study provides a strategy for sustainable Information and Communcation Technology (ICT) development in deep rural environments and describes a case study conducted within the community of the AmaJingqi traditional council. It investigates the sustainability of the ICT services within a rural environments, the income profile and affordability of different members of the community and the strategy formulation model. The study’s main focus is on creating a strategy to be used as a guideline for the successful development and implementation of sustainable ICT development in deep rural environments and on defining ICT Sustainability. Furthermore, the different ICT users are profiled based on affordability and access to services, and deep rural environments are also defined. Moreover, the study describes the complete composition of sustainable ICT. It discusses design science research methodology and the reasons why the method is used is motivated and advanced. The study also outlines various research paradigms and philosophies and a number of research strategies are also discussed. The literature review focuses on various policies and frameworks which have been formulated to advance the universal access of ICT services by rural communities. It also outlines some of the ICT initiatives which have failed and the reasons for the failures and what will be corrected for similar mistakes not to be repeated. The study discusses the concepts of a strategy framework that outlines the theoretical foundation of the strategy formulation model, strategy implementation and control. It also discusses the diagnostics and outlines the various strategy guiding polices. The strategy is validated, expert reviews are solicited and the strategy is revised and finalised.
- Full Text:
- Date Issued: 2019
A strategy to effectively manage the disaster recovery plan (DRP) at the city of Johannesburg: roads sector
- Authors: Maphutha, Selina Masai
- Date: 2019
- Subjects: Management information systems , Data recovery (Computer science) Computer security Emergency management Local government -- South Africa -- Johannesburg
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40944 , vital:36274
- Description: Electronic information is critical to Municipalities, the City of Johannesburg (Road sector) rely on computerised systems to perform their operations and deliver services to its inhabitants. Disaster recovery planning for the City of Johannesburg is crucial and urgent, as it will ensure that the organisation is able to recover the core business functionality of its software, data, and systems after the occurrence of a natural or man-made disaster. Municipalities should have adequate recovery strategies in place in case of disasters. Planning for recovery from a disaster is quickly becoming recognized as a necessity, however organisational leaders are not putting recovery strategies as a priority and thus result in challenges when implementing the recovery processes i.e. Lack of resources, overlooking risk management, lack of leadership commitment to continuity processes and lack of understanding the concept of DRP and BCP. Disruption can happen when not anticipated, It is impossible to foresee what may hit an organisation. It is thus necessary and compulsory for organisation to plan for disasters most especially with ever-increasing dependence of business processes on technology services. The purpose of this research was to assess the adequacy of the Disaster recovery plan at the City of Johannesburg (Road sector) and to develop a strategy to effectively manage the DRP. The research revealed that the DRP at the City of Johannesburg (Road sector) is not comprehensive and that there are other processes that are not effectively implemented. There is a lack of resources for implementing the DRP. The dedicated staff is not adequately technically skilled to implement the disaster recovery processes. This study has revealed that the challenges noted were common to other institutions. An adequate DRP is crucial; capacity management and seamless procurement processes are also crucial for the success of the disaster recovery processes. Theoretically, this research adds to the literature on disaster recovery management and highlights the challenges and complexities involved. Practically, the research provides several lessons and guiding principles that the organisation may consider around disaster recovery management.
- Full Text:
- Date Issued: 2019
- Authors: Maphutha, Selina Masai
- Date: 2019
- Subjects: Management information systems , Data recovery (Computer science) Computer security Emergency management Local government -- South Africa -- Johannesburg
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40944 , vital:36274
- Description: Electronic information is critical to Municipalities, the City of Johannesburg (Road sector) rely on computerised systems to perform their operations and deliver services to its inhabitants. Disaster recovery planning for the City of Johannesburg is crucial and urgent, as it will ensure that the organisation is able to recover the core business functionality of its software, data, and systems after the occurrence of a natural or man-made disaster. Municipalities should have adequate recovery strategies in place in case of disasters. Planning for recovery from a disaster is quickly becoming recognized as a necessity, however organisational leaders are not putting recovery strategies as a priority and thus result in challenges when implementing the recovery processes i.e. Lack of resources, overlooking risk management, lack of leadership commitment to continuity processes and lack of understanding the concept of DRP and BCP. Disruption can happen when not anticipated, It is impossible to foresee what may hit an organisation. It is thus necessary and compulsory for organisation to plan for disasters most especially with ever-increasing dependence of business processes on technology services. The purpose of this research was to assess the adequacy of the Disaster recovery plan at the City of Johannesburg (Road sector) and to develop a strategy to effectively manage the DRP. The research revealed that the DRP at the City of Johannesburg (Road sector) is not comprehensive and that there are other processes that are not effectively implemented. There is a lack of resources for implementing the DRP. The dedicated staff is not adequately technically skilled to implement the disaster recovery processes. This study has revealed that the challenges noted were common to other institutions. An adequate DRP is crucial; capacity management and seamless procurement processes are also crucial for the success of the disaster recovery processes. Theoretically, this research adds to the literature on disaster recovery management and highlights the challenges and complexities involved. Practically, the research provides several lessons and guiding principles that the organisation may consider around disaster recovery management.
- Full Text:
- Date Issued: 2019
A strategy to promote awareness and adherence to information security policy at Capricorn District Municipality
- Authors: Mamabolo, Mokgadi Hellen
- Date: 2019
- Subjects: Computer security -- Management , Data protection -- Management Computer security Computer networks -- Security measures
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40867 , vital:36245
- Description: The purpose of this research was to investigate the reasons for non-adherence to the ISP and to measure the current level of adherence to the ISP. The research revealed that non adherence to the ISP is caused by lack of training or awareness, and through non-communication of the ISP to employees. The study was conducted at Capricorn District Municipality, Polokwane Local Municipality, Molemole Local Municipality and Blouberg Local Municipality. A web-based questionnaire (QuestionPro) was developed and it was directed to every official who uses or interacts with municipal information, to quantify the level of adherence to ISP by employees. An email with the questionnaire link administered by www.questionpro.com was then sent to the population of 152 employees. Presently ISP adherence is one of the key concerns that are faced by organisations. Employees are perceived as one of the reasons that there are security breaches within organisations; hence, it is of paramount importance that these security breaches are noticed, as well as technical matters. Most researchers have reasoned that non-adherence to ISP is one of the major challenges faced by organisations. The non-adherence to ISP will lead to potential information security threats and unauthorised access to information that might compromise municipal business operations. The Information Security Officer together with the help of management must educate employees regarding the value of IS and why it is crucial to adhere to these policies. The proposed strategy summarises the various concepts required in the promotion of awareness and adherence to an effective ISP. Ultimately, this research study concludes that if management continually trains employees, raising awareness about ISP and monitoring their adherence to ISP, this should increase the adherence level.
- Full Text:
- Date Issued: 2019
- Authors: Mamabolo, Mokgadi Hellen
- Date: 2019
- Subjects: Computer security -- Management , Data protection -- Management Computer security Computer networks -- Security measures
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/40867 , vital:36245
- Description: The purpose of this research was to investigate the reasons for non-adherence to the ISP and to measure the current level of adherence to the ISP. The research revealed that non adherence to the ISP is caused by lack of training or awareness, and through non-communication of the ISP to employees. The study was conducted at Capricorn District Municipality, Polokwane Local Municipality, Molemole Local Municipality and Blouberg Local Municipality. A web-based questionnaire (QuestionPro) was developed and it was directed to every official who uses or interacts with municipal information, to quantify the level of adherence to ISP by employees. An email with the questionnaire link administered by www.questionpro.com was then sent to the population of 152 employees. Presently ISP adherence is one of the key concerns that are faced by organisations. Employees are perceived as one of the reasons that there are security breaches within organisations; hence, it is of paramount importance that these security breaches are noticed, as well as technical matters. Most researchers have reasoned that non-adherence to ISP is one of the major challenges faced by organisations. The non-adherence to ISP will lead to potential information security threats and unauthorised access to information that might compromise municipal business operations. The Information Security Officer together with the help of management must educate employees regarding the value of IS and why it is crucial to adhere to these policies. The proposed strategy summarises the various concepts required in the promotion of awareness and adherence to an effective ISP. Ultimately, this research study concludes that if management continually trains employees, raising awareness about ISP and monitoring their adherence to ISP, this should increase the adherence level.
- Full Text:
- Date Issued: 2019
A sustainable industrialisation model for the ocean economy of South Africa
- Authors: Williams, Mark
- Date: 2019
- Subjects: Marine resources , Shipping -- Economic aspects Marine terminals -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44401 , vital:37164
- Description: South African role players recognise that when truly exploited and well-managed, the South African ocean economy can constitute a source of wealth and significantly increase South Africa’s fortunes and, by doing so, contribute towards the increased economic growth, employment growth and ultimately the development of South Africa. However, as a result of the multi-dimensional and complex nature of ocean economic systems, role players in South Africa faced the problem of identifying the factors that influence the success of sustainable industrialisation of the ocean economy of South Africa. The aim of this research was to contribute to the promotion and sustainable development of the ocean economy of South Africa, in an effort to address the challenge mentioned above. In order to achieve this aim, the objective was to develop and test a conceptual theoretical model which will assist industrialists and other role players in South Africa to increase their economic activities sustainably in the ocean economy. Evidence from this research indicated that if the factors influencing the industrialisation of the ocean economy could be identified, assessed and recommendations could be made which may contribute to the promotion and sustainable development of the ocean economy of South Africa. The focus of the literature study was firstly on the global perspective of the marine industry, particularly how nations around the world are involved in the various components of the ocean economy and the challenges, as well as issues, the world confronts in respect of the marine industry and secondly, to give consideration to global solutions that are relevant for South Africa. The research effort, furthermore, explored South Africa’s legislative, policy and other consideration that has a direct impact on the ocean economy. The literature study on both global and South African perspectives of ocean economies found ten major variables that influence the sustainability of the industrialisation of the ocean economy of South Africa. These variables include one intervening variable, infrastructure development as well as nine independent variables namely demand planning, strategic partnering, knowledge management, access to finance, institutional environment, value-chain integration, resource management, regulatory environment, and innovation. All variables were hypothesised as they were perceived to positively influence the dependent variable namely: the perceived success of sustainable industrialisation of the ocean economy of South Africa The influencing factors, defined and operationalised, were then structured in a questionnaire which was sent randomly to specialists in the ocean economies around the world. Data was collected from 246 respondents and subjected to various statistical analysis techniques. Firstly, Exploratory Factor Analysis (EFA) was conducted to assess the discriminant validity of the research instrument. Secondly, Cronbach’s alpha coefficients were calculated for each of the identified factors to confirm the reliability of the research instrument. The significance of the hypothesised relationships in the revised model was then tested by using the statistical technique known as Structural Equation Modelling (SEM). The key contribution of this research to the South Africa’s ocean economy body of knowledge is as follows: The research into the contributing factors which influence the success of sustainable industrialisation of the ocean economy of South Africa, The development of a theoretical model for the industrialisation of the ocean economy of South Africa that can be used by role players in South Africa to promote economic activities sustainably in the ocean economy, The research investigated the ocean economy ecosystem, the global economic exploitation of the ocean and issues and challenges surrounding such exploitation, Consider South Africa’s own efforts at economic exploitation of the ocean and the issues and challenges surrounding such exploitation. Findings and recommendations on empirically accessed factors which significantly affect the likelihood of the sustainable development of the ocean economy of South Africa. In conclusion, the theoretical model and operational recommendations that are offered in this research do serve as a useful guideline as to what the key success factors are that will influence the sustainable industrialisation of the ocean economy of South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Williams, Mark
- Date: 2019
- Subjects: Marine resources , Shipping -- Economic aspects Marine terminals -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44401 , vital:37164
- Description: South African role players recognise that when truly exploited and well-managed, the South African ocean economy can constitute a source of wealth and significantly increase South Africa’s fortunes and, by doing so, contribute towards the increased economic growth, employment growth and ultimately the development of South Africa. However, as a result of the multi-dimensional and complex nature of ocean economic systems, role players in South Africa faced the problem of identifying the factors that influence the success of sustainable industrialisation of the ocean economy of South Africa. The aim of this research was to contribute to the promotion and sustainable development of the ocean economy of South Africa, in an effort to address the challenge mentioned above. In order to achieve this aim, the objective was to develop and test a conceptual theoretical model which will assist industrialists and other role players in South Africa to increase their economic activities sustainably in the ocean economy. Evidence from this research indicated that if the factors influencing the industrialisation of the ocean economy could be identified, assessed and recommendations could be made which may contribute to the promotion and sustainable development of the ocean economy of South Africa. The focus of the literature study was firstly on the global perspective of the marine industry, particularly how nations around the world are involved in the various components of the ocean economy and the challenges, as well as issues, the world confronts in respect of the marine industry and secondly, to give consideration to global solutions that are relevant for South Africa. The research effort, furthermore, explored South Africa’s legislative, policy and other consideration that has a direct impact on the ocean economy. The literature study on both global and South African perspectives of ocean economies found ten major variables that influence the sustainability of the industrialisation of the ocean economy of South Africa. These variables include one intervening variable, infrastructure development as well as nine independent variables namely demand planning, strategic partnering, knowledge management, access to finance, institutional environment, value-chain integration, resource management, regulatory environment, and innovation. All variables were hypothesised as they were perceived to positively influence the dependent variable namely: the perceived success of sustainable industrialisation of the ocean economy of South Africa The influencing factors, defined and operationalised, were then structured in a questionnaire which was sent randomly to specialists in the ocean economies around the world. Data was collected from 246 respondents and subjected to various statistical analysis techniques. Firstly, Exploratory Factor Analysis (EFA) was conducted to assess the discriminant validity of the research instrument. Secondly, Cronbach’s alpha coefficients were calculated for each of the identified factors to confirm the reliability of the research instrument. The significance of the hypothesised relationships in the revised model was then tested by using the statistical technique known as Structural Equation Modelling (SEM). The key contribution of this research to the South Africa’s ocean economy body of knowledge is as follows: The research into the contributing factors which influence the success of sustainable industrialisation of the ocean economy of South Africa, The development of a theoretical model for the industrialisation of the ocean economy of South Africa that can be used by role players in South Africa to promote economic activities sustainably in the ocean economy, The research investigated the ocean economy ecosystem, the global economic exploitation of the ocean and issues and challenges surrounding such exploitation, Consider South Africa’s own efforts at economic exploitation of the ocean and the issues and challenges surrounding such exploitation. Findings and recommendations on empirically accessed factors which significantly affect the likelihood of the sustainable development of the ocean economy of South Africa. In conclusion, the theoretical model and operational recommendations that are offered in this research do serve as a useful guideline as to what the key success factors are that will influence the sustainable industrialisation of the ocean economy of South Africa.
- Full Text:
- Date Issued: 2019
Affordability of housing in the gap market: a case of Walmer link in Port Elizabeth, South Africa
- Makeleni, Nokukhanya Precious
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
Causes of road projects’ delays: a case of Blantyre
- Authors: Mwamvani, Henry Duncan John
- Date: 2019
- Subjects: Construction industry -- Management , Engineering -- Management Project management Building -- Planning Building -- Superintendance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/41719 , vital:36575
- Description: The Construction Industry (CI) is recognised as a formidable sector that has the potential of facilitating the growth and development of a nation’s economy by providing the necessary infrastructure that is required to spur the growth of other industries. In many countries, such as Malawi, the city councils (CCs) also influence the implementation and management of such infrastructure as mandated by the Malawi Local Government Act (1998). Successful projects should be implemented in such a manner that completion of the projects is within the golden triangle of cost, time and quality. This implies that projects are completed within the planned budget, stipulated time and specified quality. City Councils in Malawi, however, face various challenges in their implementation of infrastructure projects leading to delayed project completion, resulting in extended project implementation periods. This study aimed at finding the causes of road projects construction delays in Blantyre City Council, (BCC) which is one of the four CCs in Malawi, the second largest and the commercial capital. The study followed a qualitative research method using a case study approach. This study combined in-depth, face-to-face interviews of identified stakeholders with general routine work observations and project document gathering to collect the primary data while secondary data was obtained from books, research journal articles, government documents, unpublished theses, some international organisation reports, general internet information and other academic related sources of relevant information. The participants included council representatives (council service committee chairperson, secretariat management staff), contractors’ representatives and consultants’ representatives. The participants were chosen using a non-probability sampling method of purposive and snowball selection, targeting their involvement in the previous and/or the current project implementation cycles. The study also involved visiting some of the ongoing and completed projects and collecting project photographs. The findings from the case study revealed challenges the council faced due to a shortage of engineers in conducting detailed proposed projects surveys resulting in incomplete project scope definition (detailed designs) on some projects, before the procurement of contractors as the major cause of project construction delays. Other factors that were identified were: service providers delaying the removal of existing public utility infrastructure from project sites, inclement weather and the client delays in issuing instructions to the contractors during the implementation of the projects. Another factor was the shortage of construction equipment and construction materials by some contractors. Based on the research findings, the main recommendation is to increase the number of technical employees, especially engineers and other key technical staff such as quantity surveyors by improving the employees’ conditions of service. Improving the service conditions will attract and retain the right quality and quantity of technical employees to undertake the management of the construction projects. Alternatively, all positions for professionals who are deemed as scarce or hard to maintain could be placed on a contract basis, renewable after a period of two to three years. This would be able to attract those professionals who are ready to offer their expertise for a certain period but may not necessarily want to work until the government mandatory retirement. This will be in addition to the engagement of external project consultants to assist in project management, which the council started implementing in 2017. As for the delay in the removal of utility services infrastructure on proposed project sites, the client needs to commence with the process early in the planning and procurement process before handing over the project sites to the contractors. General contractor delay causes can be minimised by raising the selection criteria of contractors to flush out as well as black-listing incompetent contractors.
- Full Text:
- Date Issued: 2019
- Authors: Mwamvani, Henry Duncan John
- Date: 2019
- Subjects: Construction industry -- Management , Engineering -- Management Project management Building -- Planning Building -- Superintendance
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/41719 , vital:36575
- Description: The Construction Industry (CI) is recognised as a formidable sector that has the potential of facilitating the growth and development of a nation’s economy by providing the necessary infrastructure that is required to spur the growth of other industries. In many countries, such as Malawi, the city councils (CCs) also influence the implementation and management of such infrastructure as mandated by the Malawi Local Government Act (1998). Successful projects should be implemented in such a manner that completion of the projects is within the golden triangle of cost, time and quality. This implies that projects are completed within the planned budget, stipulated time and specified quality. City Councils in Malawi, however, face various challenges in their implementation of infrastructure projects leading to delayed project completion, resulting in extended project implementation periods. This study aimed at finding the causes of road projects construction delays in Blantyre City Council, (BCC) which is one of the four CCs in Malawi, the second largest and the commercial capital. The study followed a qualitative research method using a case study approach. This study combined in-depth, face-to-face interviews of identified stakeholders with general routine work observations and project document gathering to collect the primary data while secondary data was obtained from books, research journal articles, government documents, unpublished theses, some international organisation reports, general internet information and other academic related sources of relevant information. The participants included council representatives (council service committee chairperson, secretariat management staff), contractors’ representatives and consultants’ representatives. The participants were chosen using a non-probability sampling method of purposive and snowball selection, targeting their involvement in the previous and/or the current project implementation cycles. The study also involved visiting some of the ongoing and completed projects and collecting project photographs. The findings from the case study revealed challenges the council faced due to a shortage of engineers in conducting detailed proposed projects surveys resulting in incomplete project scope definition (detailed designs) on some projects, before the procurement of contractors as the major cause of project construction delays. Other factors that were identified were: service providers delaying the removal of existing public utility infrastructure from project sites, inclement weather and the client delays in issuing instructions to the contractors during the implementation of the projects. Another factor was the shortage of construction equipment and construction materials by some contractors. Based on the research findings, the main recommendation is to increase the number of technical employees, especially engineers and other key technical staff such as quantity surveyors by improving the employees’ conditions of service. Improving the service conditions will attract and retain the right quality and quantity of technical employees to undertake the management of the construction projects. Alternatively, all positions for professionals who are deemed as scarce or hard to maintain could be placed on a contract basis, renewable after a period of two to three years. This would be able to attract those professionals who are ready to offer their expertise for a certain period but may not necessarily want to work until the government mandatory retirement. This will be in addition to the engagement of external project consultants to assist in project management, which the council started implementing in 2017. As for the delay in the removal of utility services infrastructure on proposed project sites, the client needs to commence with the process early in the planning and procurement process before handing over the project sites to the contractors. General contractor delay causes can be minimised by raising the selection criteria of contractors to flush out as well as black-listing incompetent contractors.
- Full Text:
- Date Issued: 2019
Characterisation of single event effects and total ionising dose effects of an intel atom microprocessor
- Authors: Malinda, Muema
- Date: 2019
- Subjects: Microprocessors , Mechatronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/41875 , vital:36605
- Description: The rapid advancements of COTS microprocessors compared to radiation hardened microprocessors has attracted the interest of system designers within the aerospace sector. COTS microprocessors offer higher performance with lower energy requirements, both of which are desired characteristics for microprocessors used in spacecraft. COTS microprocessors, however, are much more susceptible to radiation damage therefore their SEE and TID responses needs to be evaluated before they can be incorporated into spacecraft. This thesis presents the process followed to evaluate said characteristics of a COTS Intel Atom E3815 microprocessor mounted on a DE3815TYBE single board PC. Evaluation of the SEE response was carried out at NRF iThemba Labs in Cape Town, South Africa where the device was irradiated by a proton beam at 55.58 MeV and with varying beam currents. The device showed a higher sensitivity to functional interrupts when running with the onboard cache on compared to when running with the cache off, as would be expected. The cross-sections, respectively, are: 4.5𝑥 10−10 𝑐𝑚2 and 2.8 𝑥 10−10 𝑐𝑚2. TID testing on the other hand was carried out at the irradiation chamber of FruitFly Africa in Stellenbosch, South Africa. The test device was irradiated by gamma radiation from a Cobalt-60 source at a dose rate of 9.7kRad/h and to a total dose of 67.25kRad. Noticeable TID degradation, in the form of leakage currents, was observed once a total dose of about 20kRad was absorbed. The device then completely failed once a total dose of approximately 32kRad was absorbed. These results suggest that the E3815 microprocessor would not be suitable for long term missions that require higher TID survivability. The processor could however be considered for short term missions launched into polar or high incline orbits where the dose rate is relatively low, and the mission is capable of tolerating functional interrupts.
- Full Text:
- Date Issued: 2019
- Authors: Malinda, Muema
- Date: 2019
- Subjects: Microprocessors , Mechatronics
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/41875 , vital:36605
- Description: The rapid advancements of COTS microprocessors compared to radiation hardened microprocessors has attracted the interest of system designers within the aerospace sector. COTS microprocessors offer higher performance with lower energy requirements, both of which are desired characteristics for microprocessors used in spacecraft. COTS microprocessors, however, are much more susceptible to radiation damage therefore their SEE and TID responses needs to be evaluated before they can be incorporated into spacecraft. This thesis presents the process followed to evaluate said characteristics of a COTS Intel Atom E3815 microprocessor mounted on a DE3815TYBE single board PC. Evaluation of the SEE response was carried out at NRF iThemba Labs in Cape Town, South Africa where the device was irradiated by a proton beam at 55.58 MeV and with varying beam currents. The device showed a higher sensitivity to functional interrupts when running with the onboard cache on compared to when running with the cache off, as would be expected. The cross-sections, respectively, are: 4.5𝑥 10−10 𝑐𝑚2 and 2.8 𝑥 10−10 𝑐𝑚2. TID testing on the other hand was carried out at the irradiation chamber of FruitFly Africa in Stellenbosch, South Africa. The test device was irradiated by gamma radiation from a Cobalt-60 source at a dose rate of 9.7kRad/h and to a total dose of 67.25kRad. Noticeable TID degradation, in the form of leakage currents, was observed once a total dose of about 20kRad was absorbed. The device then completely failed once a total dose of approximately 32kRad was absorbed. These results suggest that the E3815 microprocessor would not be suitable for long term missions that require higher TID survivability. The processor could however be considered for short term missions launched into polar or high incline orbits where the dose rate is relatively low, and the mission is capable of tolerating functional interrupts.
- Full Text:
- Date Issued: 2019
Improvements and optimization for a functional low-cost prosthetic hand
- Authors: Setty, Kiran
- Date: 2019
- Subjects: Biomechanics , Artificial limbs -- Design , Prosthesis -- Design
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/43655 , vital:36955
- Description: The following study investigates the work of the Touch Hand 4, which involves the development of a lowcost myoelectric prosthetic terminal hand device for transradial amputees. The Touch Hand 4 is an iteration of the Touch Hand project which attempts to make a functional, low-cost prosthetic hand which is capable of being accessible to more people relative to conventional myoelectric prosthetic hands as well as being used as a robotic UAV gripper. This research is motivated due to the lack of affordable myoelectric prosthetic hands in the global market. It is believed, with the current technology, it is capable of developing a prosthetic hand which can meet these needs. Research was performed through reviewing other prosthetic hands to understand the requirements for a prosthetic hand as well as understanding the market of prosthetic hands. Prosthetists were interviewed to obtain a perspective from medial professionals regarding the requirements for a prosthetic hand. Hand kinesiology was performed to understand the biomechanics of the human hand, which was emulated in the design of the Touch Hand 4. The mechanical design begun with developing and testing a concept design, which was used to design the general shape of the Touch Hand 4. SLS was chosen to print the prosthetic hand with. After performing a kinematics and static force simulation, the mechanical system was designed accordingly. Further research on EMG sensors was then performed to understand the requirements of using EMG signals to control a prosthetic hand. The electronics and control system were then designed according to the requirements of the prosthetic hand. Tests were performed, however, tests performed with an amputee using the device was affected to improper placement of the EMG sensors, leading to poor results. Tests performed without an amputee, however, showed that the prosthetic hand is capable of gripping various objects of different shapes and sizes. An investigation was also performed on the contributions the Touch Hand 4 could make as a UAV gripper, which showed that the Touch Hand 4 is more adaptable and versatile than any other UAV gripper available on the market.
- Full Text:
- Date Issued: 2019
- Authors: Setty, Kiran
- Date: 2019
- Subjects: Biomechanics , Artificial limbs -- Design , Prosthesis -- Design
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/43655 , vital:36955
- Description: The following study investigates the work of the Touch Hand 4, which involves the development of a lowcost myoelectric prosthetic terminal hand device for transradial amputees. The Touch Hand 4 is an iteration of the Touch Hand project which attempts to make a functional, low-cost prosthetic hand which is capable of being accessible to more people relative to conventional myoelectric prosthetic hands as well as being used as a robotic UAV gripper. This research is motivated due to the lack of affordable myoelectric prosthetic hands in the global market. It is believed, with the current technology, it is capable of developing a prosthetic hand which can meet these needs. Research was performed through reviewing other prosthetic hands to understand the requirements for a prosthetic hand as well as understanding the market of prosthetic hands. Prosthetists were interviewed to obtain a perspective from medial professionals regarding the requirements for a prosthetic hand. Hand kinesiology was performed to understand the biomechanics of the human hand, which was emulated in the design of the Touch Hand 4. The mechanical design begun with developing and testing a concept design, which was used to design the general shape of the Touch Hand 4. SLS was chosen to print the prosthetic hand with. After performing a kinematics and static force simulation, the mechanical system was designed accordingly. Further research on EMG sensors was then performed to understand the requirements of using EMG signals to control a prosthetic hand. The electronics and control system were then designed according to the requirements of the prosthetic hand. Tests were performed, however, tests performed with an amputee using the device was affected to improper placement of the EMG sensors, leading to poor results. Tests performed without an amputee, however, showed that the prosthetic hand is capable of gripping various objects of different shapes and sizes. An investigation was also performed on the contributions the Touch Hand 4 could make as a UAV gripper, which showed that the Touch Hand 4 is more adaptable and versatile than any other UAV gripper available on the market.
- Full Text:
- Date Issued: 2019
Improving the property rental market in Tshwane CBD
- Authors: Kganyago, Rapholo Joseph
- Date: 2019
- Subjects: Real property -- South Africa -- Pretoria , Rental housing -- South Africa -- Pretoria Building leases -- South Africa -- Pretoria Housing -- South Africa -- Pretoria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40588 , vital:36185
- Description: The research focuses on investigating the Improvement of the property rental market in Tshwane CBD. This includes determining the factors leading to high dilapidation of the Tshwane rental properties in its CBD as well as establishing the challenges experienced by the tenants in respect to the comfort and safety of their rented properties. This includes determining challenges faced by the rental property owners in establishing safe, comfortable housing facilities that fulfill the tenants’ expectations. The research further determines to illuminate on economic opportunities that can be realised in improving the conditions of the rental property market. The research employs a mixed research approach, where 100 survey participants and 10 qualitative interviewees are used to gather empirical evidence for the study. This manages to bring congruency to the outcomes of the study. The research finds that rent seeking behaviours are prevalent in the Tshwane rental property market. The study finds that there is lack of adequate management of rental properties owing to challenges with timely maintenance costs that affect most rented properties in the CBD. The research illuminates further that rental property owners and employed agencies are not effectively upgrading or modifying security features in their commercialized units much to diminished safety of property and most importantly the tenants. The research also exposes that foreign nationals in rental property market are also part of the rent-seeking behaviours through some hidden costs and penalties that do not align with local authority regulations to unsuspecting and prospective tenants much like local rental property stakeholders. The research has recommended that regulatory agencies in the rental property market must be trained and assessed on performance metrics continuously to ensure that they effectively address and expose issues such as latent defects, health inspections of properties and a better understanding of rental property dynamics at inspection and certification of rental units as fit for commercial business. The research further recommends that urbanisation through gentrification requires sustainable partnerships between both private and public construction sector players with adequate consultation with communities affected near CBDs to encourage building of more structures that are affordable to middle-income earners residing in affected rental areas identified in the research phenomenon.
- Full Text:
- Date Issued: 2019
- Authors: Kganyago, Rapholo Joseph
- Date: 2019
- Subjects: Real property -- South Africa -- Pretoria , Rental housing -- South Africa -- Pretoria Building leases -- South Africa -- Pretoria Housing -- South Africa -- Pretoria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40588 , vital:36185
- Description: The research focuses on investigating the Improvement of the property rental market in Tshwane CBD. This includes determining the factors leading to high dilapidation of the Tshwane rental properties in its CBD as well as establishing the challenges experienced by the tenants in respect to the comfort and safety of their rented properties. This includes determining challenges faced by the rental property owners in establishing safe, comfortable housing facilities that fulfill the tenants’ expectations. The research further determines to illuminate on economic opportunities that can be realised in improving the conditions of the rental property market. The research employs a mixed research approach, where 100 survey participants and 10 qualitative interviewees are used to gather empirical evidence for the study. This manages to bring congruency to the outcomes of the study. The research finds that rent seeking behaviours are prevalent in the Tshwane rental property market. The study finds that there is lack of adequate management of rental properties owing to challenges with timely maintenance costs that affect most rented properties in the CBD. The research illuminates further that rental property owners and employed agencies are not effectively upgrading or modifying security features in their commercialized units much to diminished safety of property and most importantly the tenants. The research also exposes that foreign nationals in rental property market are also part of the rent-seeking behaviours through some hidden costs and penalties that do not align with local authority regulations to unsuspecting and prospective tenants much like local rental property stakeholders. The research has recommended that regulatory agencies in the rental property market must be trained and assessed on performance metrics continuously to ensure that they effectively address and expose issues such as latent defects, health inspections of properties and a better understanding of rental property dynamics at inspection and certification of rental units as fit for commercial business. The research further recommends that urbanisation through gentrification requires sustainable partnerships between both private and public construction sector players with adequate consultation with communities affected near CBDs to encourage building of more structures that are affordable to middle-income earners residing in affected rental areas identified in the research phenomenon.
- Full Text:
- Date Issued: 2019
Influence of laser surface treatment on residual stress distribution and dynamic properties in rotary friction welded ti-6al-4v components
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
Laser welding of thin-walled stainless steel tubing
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019