Characterisation of Young's modulus and loss factor of damping materials
- Authors: Nortemann, Markus
- Date: 2014
- Subjects: Elasticity , Simulation methods , Damping (Mechanics)
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9662 , http://hdl.handle.net/10948/d1021036
- Description: Given the importance of simulation techniques in automotive engineering, there is a lack of implementation regarding these techniques in the acoustics of damping materials for air-borne sound. Biot’s calculations have proven its abilities to simulate the acoustic characteristics of these damping materials. However, the characterisation of essential structural parameters, such as Young’s modulus and loss factor, in order to conduct Biot’s calculations have been inconclusive. Thus, the primary research objective of this study is to propose a new measurement system for the structural Biot parameters. After a comprehensive literature review has been undertaken on damping materials, as well as measurement apparatuses for Young’s modulus and loss factor of damping materials, two causes of measurement errors have been identified. Unknown stresses in measurement apparatuses and inhomogeneous, polytrophic and viscoelastic behaviour of specimens. A new measurement system that does not affect the specimens with unknown stresses and accounts for their complex behaviour required investigation. Non-contact ultrasound had been selected as a solution to determine the aforementioned parameters, since these methods do not necessarily touch or compress the specimen, which led to unknown stresses and neglection of the complex specimen behaviour with the aforementioned techniques. Although ultrasound had been used to determine structural parameters on various types of materials, it has never been used to measure soft porous damping materials. In order to find possible solutions, various sources using ultrasonics to investigate struc- tural parameters had been reviewed. In order to calculate structural parameters, the longitudinal and transversal wave velocity inside the specimen had to be determined. The main findings showed that non-contact ultrasound will be able to evaluate the Young’s modulus, loss factor as well as Poisson’s ratio. Consequently, it was shown that longitudinal velocity measurements could be conducted using well known transmission measurements. However, well known approaches would not be sufficient measuring the transversal wave velocity in soft damping materials. This problem was addressed with a special gas to be used, with lower sound speed velocity in the fluid than in the solid. Moreso, a new method determining the transversal wave velocity had been found, as it would enable the use of an even larger range of damping materials, especially ones with heavy frames and lower porosity. It will use refracted waves inside the specimen and the determination of the convertion position of the transversal to the longitudinal wave at the rear specimen surface. At the end of the study, hardware components were selected and a test rig was constructed, which should be able to prove that a determination of structural Biot parameters with non-contact ultrasound is possible with less errors instead of using mechanical transfer function systems. The development of measurement software as well as the testing of the measurement system and its validation was not under investigation in this dissertation. This study has expanded on the body of literature knowledge regarding non-contact ultrasound. Furthermore, a significant contribution has been made towards a new measurement system measuring Young’s modulus and loss factor which circumvents errors in mechanical transfer function systems. This will contribute to more precise simulations of damping materials and damped enclosures, which may ultimately result in enhanced efficiency of damping materials as well as the acoustic packaging of cars.
- Full Text:
- Date Issued: 2014
- Authors: Nortemann, Markus
- Date: 2014
- Subjects: Elasticity , Simulation methods , Damping (Mechanics)
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9662 , http://hdl.handle.net/10948/d1021036
- Description: Given the importance of simulation techniques in automotive engineering, there is a lack of implementation regarding these techniques in the acoustics of damping materials for air-borne sound. Biot’s calculations have proven its abilities to simulate the acoustic characteristics of these damping materials. However, the characterisation of essential structural parameters, such as Young’s modulus and loss factor, in order to conduct Biot’s calculations have been inconclusive. Thus, the primary research objective of this study is to propose a new measurement system for the structural Biot parameters. After a comprehensive literature review has been undertaken on damping materials, as well as measurement apparatuses for Young’s modulus and loss factor of damping materials, two causes of measurement errors have been identified. Unknown stresses in measurement apparatuses and inhomogeneous, polytrophic and viscoelastic behaviour of specimens. A new measurement system that does not affect the specimens with unknown stresses and accounts for their complex behaviour required investigation. Non-contact ultrasound had been selected as a solution to determine the aforementioned parameters, since these methods do not necessarily touch or compress the specimen, which led to unknown stresses and neglection of the complex specimen behaviour with the aforementioned techniques. Although ultrasound had been used to determine structural parameters on various types of materials, it has never been used to measure soft porous damping materials. In order to find possible solutions, various sources using ultrasonics to investigate struc- tural parameters had been reviewed. In order to calculate structural parameters, the longitudinal and transversal wave velocity inside the specimen had to be determined. The main findings showed that non-contact ultrasound will be able to evaluate the Young’s modulus, loss factor as well as Poisson’s ratio. Consequently, it was shown that longitudinal velocity measurements could be conducted using well known transmission measurements. However, well known approaches would not be sufficient measuring the transversal wave velocity in soft damping materials. This problem was addressed with a special gas to be used, with lower sound speed velocity in the fluid than in the solid. Moreso, a new method determining the transversal wave velocity had been found, as it would enable the use of an even larger range of damping materials, especially ones with heavy frames and lower porosity. It will use refracted waves inside the specimen and the determination of the convertion position of the transversal to the longitudinal wave at the rear specimen surface. At the end of the study, hardware components were selected and a test rig was constructed, which should be able to prove that a determination of structural Biot parameters with non-contact ultrasound is possible with less errors instead of using mechanical transfer function systems. The development of measurement software as well as the testing of the measurement system and its validation was not under investigation in this dissertation. This study has expanded on the body of literature knowledge regarding non-contact ultrasound. Furthermore, a significant contribution has been made towards a new measurement system measuring Young’s modulus and loss factor which circumvents errors in mechanical transfer function systems. This will contribute to more precise simulations of damping materials and damped enclosures, which may ultimately result in enhanced efficiency of damping materials as well as the acoustic packaging of cars.
- Full Text:
- Date Issued: 2014
Development of a mechatronic transmission control system for the drivetrain of the K71 project
- Authors: Nortemann, Alexander
- Date: 2014
- Subjects: Motor vehicles -- Transmission devices , Automobiles -- Power trains , Automobile driving -- Shifting gear
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9659
- Description: The tractive force has to be interrupted during a gear-shifting operation in a manual vehicle transmission, leading into a decrease of speed while changing gears during the acceleration process. Therefore in a racing application, the shifting time has to be as short as possible so that the required performance of a racing car can be achieved. The following dissertation describes the development of a transmission control system to enable gear changes within a manual gearbox, which was designed for the Formula Student racing series. Various solutions were developed on the basis of reviewed literature, technical data of components and experiences of Formula Student teams. Following this, a comparison of the concepts by means of a utility analysis identified the pneumatic actuation of selector forks to be the most suitable concept. This was mainly due to the expected shifting time, the weight, and its advantageous energy supply requirement. After the selection of the actuators and the position sensors, the system was implemented into the drivetrain to check the tment and the technical feasibility. To draw conclusions regarding the shifting time and to prove the functionality of the system, an open test bench was constructed. Additionally, the hardware and software had to be developed to enable the test run. After the manufacturing and assembling of the test bench, the optimal settings for the test run were determined. By comparing the achieved shifting time of alternative solutions, an improvement in the driving performance of a Formula Student race car is probable.
- Full Text:
- Date Issued: 2014
- Authors: Nortemann, Alexander
- Date: 2014
- Subjects: Motor vehicles -- Transmission devices , Automobiles -- Power trains , Automobile driving -- Shifting gear
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: vital:9659
- Description: The tractive force has to be interrupted during a gear-shifting operation in a manual vehicle transmission, leading into a decrease of speed while changing gears during the acceleration process. Therefore in a racing application, the shifting time has to be as short as possible so that the required performance of a racing car can be achieved. The following dissertation describes the development of a transmission control system to enable gear changes within a manual gearbox, which was designed for the Formula Student racing series. Various solutions were developed on the basis of reviewed literature, technical data of components and experiences of Formula Student teams. Following this, a comparison of the concepts by means of a utility analysis identified the pneumatic actuation of selector forks to be the most suitable concept. This was mainly due to the expected shifting time, the weight, and its advantageous energy supply requirement. After the selection of the actuators and the position sensors, the system was implemented into the drivetrain to check the tment and the technical feasibility. To draw conclusions regarding the shifting time and to prove the functionality of the system, an open test bench was constructed. Additionally, the hardware and software had to be developed to enable the test run. After the manufacturing and assembling of the test bench, the optimal settings for the test run were determined. By comparing the achieved shifting time of alternative solutions, an improvement in the driving performance of a Formula Student race car is probable.
- Full Text:
- Date Issued: 2014
Effectiveness of the project management profession in the Ugandan oil industry : performance, benefits and challenges
- Authors: Kiggundu, Kamulegeya John
- Date: 2014
- Subjects: Project Mangement -- Uganda , Oil industry workers -- Uganda , Benchmarking (Management) -- Uganda
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9707 , http://hdl.handle.net/10948/d1020059
- Description: Oil is one of the most valuable resources. For a country like Uganda, which is one of the least developed countries in the world with more than one third of the population still living below the poverty line; the discovery of this valuable resource has the capacity to radically alter the economy of the country. But on the other hand, oil exploration, mining and refining are complex, costly, long duration projects with many challenges that require sophisticated financial management, planning, scheduling and cost control. The project management profession is charged as a single point of responsibility for initiating, planning, executing, monitoring and controlling projects in order to meet stakeholder’s needs and expectations. The research objectives were: 1. To identify and examine the challenges and risks associated with the oil industry in Uganda. 2. To investigate the effectiveness of project management practices in the Ugandan oil industry in terms 1 above. 3. Identify how project success can be measured in the Ugandan oil industry. A case study was the research technique adopted and interviews were conducted with the major stakeholders in the Ugandan oil industry. The research findings reveal the challenges and risks that continue to plague the Ugandan oil industry and the role of project management in the exploration phase of the project. The research findings were used to evaluate the role, responsibility and service that project management professionals are expected to render and the actual role, responsibility and service that the professionals have been rendering to the stakeholders in the Ugandan oil industry. The research then concludes by proposing ways of improving the chances of project success in the Ugandan oil industry.
- Full Text:
- Date Issued: 2014
- Authors: Kiggundu, Kamulegeya John
- Date: 2014
- Subjects: Project Mangement -- Uganda , Oil industry workers -- Uganda , Benchmarking (Management) -- Uganda
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9707 , http://hdl.handle.net/10948/d1020059
- Description: Oil is one of the most valuable resources. For a country like Uganda, which is one of the least developed countries in the world with more than one third of the population still living below the poverty line; the discovery of this valuable resource has the capacity to radically alter the economy of the country. But on the other hand, oil exploration, mining and refining are complex, costly, long duration projects with many challenges that require sophisticated financial management, planning, scheduling and cost control. The project management profession is charged as a single point of responsibility for initiating, planning, executing, monitoring and controlling projects in order to meet stakeholder’s needs and expectations. The research objectives were: 1. To identify and examine the challenges and risks associated with the oil industry in Uganda. 2. To investigate the effectiveness of project management practices in the Ugandan oil industry in terms 1 above. 3. Identify how project success can be measured in the Ugandan oil industry. A case study was the research technique adopted and interviews were conducted with the major stakeholders in the Ugandan oil industry. The research findings reveal the challenges and risks that continue to plague the Ugandan oil industry and the role of project management in the exploration phase of the project. The research findings were used to evaluate the role, responsibility and service that project management professionals are expected to render and the actual role, responsibility and service that the professionals have been rendering to the stakeholders in the Ugandan oil industry. The research then concludes by proposing ways of improving the chances of project success in the Ugandan oil industry.
- Full Text:
- Date Issued: 2014
Factors impacting Tablet PC usage in low-income communities
- Authors: Meiring, Natalie
- Date: 2014
- Subjects: Information technology -- Economic aspects , Information technology -- Social aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/4642 , vital:20625
- Description: The purpose of this research was to identify factors that impact on tablet PC usage in low-income communities. In order to determine and identify these factors a main research question and sub-research questions were formulated. The primary research question of this study was "What factors impact on tablet PC usage in low-income communities?" This main research question was answered by creating three sub-research questions followed by triangulating the results from these questions. The first sub-research question was aimed at determining whether prior exposure to touch screen technology impacts the user experience. In order to reach this objective an extensive literature review was conducted on the tablet PC landscape in South Africa. This literature review, coupled with the case study helped answer this first research question. The second sub-research question was concerned with determining whether existing user experience guidelines are relevant to South African users. A thorough literature review was conducted on user experience guidelines and related studies. This literature review, together with the results from the case study helped answer this second research question. The third sub-research question involved identifying specific factors which help improve the user experience of tablet PC users in a specific context. This research question was addressed in the case study. Each sub-research question provided results which were analysed in order to answer the main research question. The factors which impact on tablet PC usage were thus identified and recommendations were proposed.
- Full Text:
- Date Issued: 2014
- Authors: Meiring, Natalie
- Date: 2014
- Subjects: Information technology -- Economic aspects , Information technology -- Social aspects
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/4642 , vital:20625
- Description: The purpose of this research was to identify factors that impact on tablet PC usage in low-income communities. In order to determine and identify these factors a main research question and sub-research questions were formulated. The primary research question of this study was "What factors impact on tablet PC usage in low-income communities?" This main research question was answered by creating three sub-research questions followed by triangulating the results from these questions. The first sub-research question was aimed at determining whether prior exposure to touch screen technology impacts the user experience. In order to reach this objective an extensive literature review was conducted on the tablet PC landscape in South Africa. This literature review, coupled with the case study helped answer this first research question. The second sub-research question was concerned with determining whether existing user experience guidelines are relevant to South African users. A thorough literature review was conducted on user experience guidelines and related studies. This literature review, together with the results from the case study helped answer this second research question. The third sub-research question involved identifying specific factors which help improve the user experience of tablet PC users in a specific context. This research question was addressed in the case study. Each sub-research question provided results which were analysed in order to answer the main research question. The factors which impact on tablet PC usage were thus identified and recommendations were proposed.
- Full Text:
- Date Issued: 2014
Guidelines to address the human factor in the South African National Research and Education Network beneficiary institutions
- Authors: Mjikeliso, Yolanda
- Date: 2014
- Subjects: National Research and Education Network (Computer network) Information networks -- South Africa Computer networks -- Security measures -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/9946 , vital:26635
- Description: Even if all the technical security solutions appropriate for an organisation’s network are implemented, for example, firewalls, antivirus programs and encryption, if the human factor is neglected then these technical security solutions will serve no purpose. The greatest challenge to network security is probably not the technological solutions that organisations invest in, but the human factor (non-technical solutions), which most organisations neglect. The human factor is often ignored even though humans are the most important resources of organisations and perform all the physical tasks, configure and manage equipment, enter data, manage people and operate the systems and networks. The same people that manage and operate networks and systems have vulnerabilities. They are not perfect and there will always be an element of mistake-making or error. In other words, humans make mistakes that could result in security vulnerabilities, and the exploitation of these vulnerabilities could in turn result in network security breaches. Human vulnerabilities are driven by many factors including insufficient security education, training and awareness, a lack of security policies and procedures in the organisation, a limited attention span and negligence. Network security may thus be compromised by this human vulnerability. In the context of this dissertation, both physical and technological controls should be implemented to ensure the security of the SANReN network. However, if the human factors are not adequately addressed, the network would become vulnerable to risks posed by the human factor which could threaten the security of the network. Accordingly, the primary research objective of this study is to formulate guidelines that address the information security related human factors in the rolling out and continued management of the SANReN network. An analysis of existing policies and procedures governing the SANReN network was conducted and it was determined that there are currently no guidelines addressing the human factor in the SANReN beneficiary institutions. Therefore, the aim of this study is to provide the guidelines for addressing the human factor threats in the SANReN beneficiary institutions.
- Full Text:
- Date Issued: 2014
- Authors: Mjikeliso, Yolanda
- Date: 2014
- Subjects: National Research and Education Network (Computer network) Information networks -- South Africa Computer networks -- Security measures -- South Africa
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/9946 , vital:26635
- Description: Even if all the technical security solutions appropriate for an organisation’s network are implemented, for example, firewalls, antivirus programs and encryption, if the human factor is neglected then these technical security solutions will serve no purpose. The greatest challenge to network security is probably not the technological solutions that organisations invest in, but the human factor (non-technical solutions), which most organisations neglect. The human factor is often ignored even though humans are the most important resources of organisations and perform all the physical tasks, configure and manage equipment, enter data, manage people and operate the systems and networks. The same people that manage and operate networks and systems have vulnerabilities. They are not perfect and there will always be an element of mistake-making or error. In other words, humans make mistakes that could result in security vulnerabilities, and the exploitation of these vulnerabilities could in turn result in network security breaches. Human vulnerabilities are driven by many factors including insufficient security education, training and awareness, a lack of security policies and procedures in the organisation, a limited attention span and negligence. Network security may thus be compromised by this human vulnerability. In the context of this dissertation, both physical and technological controls should be implemented to ensure the security of the SANReN network. However, if the human factors are not adequately addressed, the network would become vulnerable to risks posed by the human factor which could threaten the security of the network. Accordingly, the primary research objective of this study is to formulate guidelines that address the information security related human factors in the rolling out and continued management of the SANReN network. An analysis of existing policies and procedures governing the SANReN network was conducted and it was determined that there are currently no guidelines addressing the human factor in the SANReN beneficiary institutions. Therefore, the aim of this study is to provide the guidelines for addressing the human factor threats in the SANReN beneficiary institutions.
- Full Text:
- Date Issued: 2014
Integration of an electrical discharge machining module onto a reconfigurable machine tool
- Authors: Roberts, Bryndan
- Date: 2014
- Subjects: Machine-tools -- Numerical control , Electric discharges , Manufacturing processes
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: http://hdl.handle.net/10948/6182 , vital:21047
- Description: Electrical Discharge Machining (EDM) is a non-contact manufacturing process in which material is removed from a metal workpiece by high frequency electrical pulses produced between an electrode and the workpiece. EDM machines are usually stand-alone devices, and are quite expensive. The objective of this research was to integrate an EDM machine and an existing reconfigurable CNC machine tool, using a modular approach, to enable conventional milling and EDM to be conducted in a co-ordinated fashion on the same machine tool.
- Full Text:
- Date Issued: 2014
- Authors: Roberts, Bryndan
- Date: 2014
- Subjects: Machine-tools -- Numerical control , Electric discharges , Manufacturing processes
- Language: English
- Type: Thesis , Masters , MEngineering (Mechatronics)
- Identifier: http://hdl.handle.net/10948/6182 , vital:21047
- Description: Electrical Discharge Machining (EDM) is a non-contact manufacturing process in which material is removed from a metal workpiece by high frequency electrical pulses produced between an electrode and the workpiece. EDM machines are usually stand-alone devices, and are quite expensive. The objective of this research was to integrate an EDM machine and an existing reconfigurable CNC machine tool, using a modular approach, to enable conventional milling and EDM to be conducted in a co-ordinated fashion on the same machine tool.
- Full Text:
- Date Issued: 2014
Laser bending of commercially pure grade 2 titanium alloy plates: mechanisms analysis and characterisation of mechanical properties
- Authors: Mjali, Kadephi Vuyolwethu
- Date: 2014
- Subjects: Materials -- Mechanical properties , Bending , Titanium-aluminum alloys
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9642 , http://hdl.handle.net/10948/d1021147
- Description: The processing of materials has become a specialist field and the industry will continue to grow due to rising costs in labour and raw materials which has forced many automotive industry suppliers to invest heavily in this field. In order to be relevant and competitive in today’s industrial world, companies in South Africa are now forced to dedicate billions of rands in profits to research and development. Metals like titanium are finding favour with automotive and aviation companies in pursuit of savings in fuel consumption. This saving is achieved by reducing weight on aircraft and automobiles yet still meeting acceptable and improved structural integrity. In-depth research into the behaviour of various materials under varying loading conditions is therefore essential. The study on the processing of commercially pure grade 2 titanium alloy plates focuses on the development of process parameters for bending the material using a 4kW Nd: YAG laser to an approximate radius of curvature of 120mm. The resulting mechanical properties of laser formed plates are then compared to those obtained from mechanically formed samples. The titanium parent material was used to benchmark the performance of formed samples. The effect of process parameters on the mechanical properties and structural integrity also formed part of this study. To obtain the bending parameters for laser forming, various combinations of processing speeds and laser powers were used. The line energy is dependent on the power and scanning velocity parameters and these are shown in table 1. The laser power, line energy and scanning velocity were the main parameters controlled in this study and the beam diameter remained unchanged. Residual stress analysis, micro-hardness and fatigue life testing were carried out to analyse mechanical properties and the structural integrity of the plate samples. Microstructural analysis was also done to observe changes in the material as a result of the forming processes. From the results it is evident that laser forming is beneficial to the hardness of titanium but detrimental to the fatigue life at higher line energies. Residual stress analysis showed the amount of stress within the study samples increased with each forming operation. This information was vital in the analysis of the fatigue life of titanium. A fatigue life prediction model was developed from this study and it shed some light on the behaviour of titanium in fatigue testing. The model could be used to predict fatigue life when no fatigue data is available for commercially pure grade 2 titanium alloy plates. In conclusion, this study helped establish parameters that could be used to bend titanium while the analysis of mechanical properties showed the limits of working with this alloy.
- Full Text:
- Date Issued: 2014
- Authors: Mjali, Kadephi Vuyolwethu
- Date: 2014
- Subjects: Materials -- Mechanical properties , Bending , Titanium-aluminum alloys
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9642 , http://hdl.handle.net/10948/d1021147
- Description: The processing of materials has become a specialist field and the industry will continue to grow due to rising costs in labour and raw materials which has forced many automotive industry suppliers to invest heavily in this field. In order to be relevant and competitive in today’s industrial world, companies in South Africa are now forced to dedicate billions of rands in profits to research and development. Metals like titanium are finding favour with automotive and aviation companies in pursuit of savings in fuel consumption. This saving is achieved by reducing weight on aircraft and automobiles yet still meeting acceptable and improved structural integrity. In-depth research into the behaviour of various materials under varying loading conditions is therefore essential. The study on the processing of commercially pure grade 2 titanium alloy plates focuses on the development of process parameters for bending the material using a 4kW Nd: YAG laser to an approximate radius of curvature of 120mm. The resulting mechanical properties of laser formed plates are then compared to those obtained from mechanically formed samples. The titanium parent material was used to benchmark the performance of formed samples. The effect of process parameters on the mechanical properties and structural integrity also formed part of this study. To obtain the bending parameters for laser forming, various combinations of processing speeds and laser powers were used. The line energy is dependent on the power and scanning velocity parameters and these are shown in table 1. The laser power, line energy and scanning velocity were the main parameters controlled in this study and the beam diameter remained unchanged. Residual stress analysis, micro-hardness and fatigue life testing were carried out to analyse mechanical properties and the structural integrity of the plate samples. Microstructural analysis was also done to observe changes in the material as a result of the forming processes. From the results it is evident that laser forming is beneficial to the hardness of titanium but detrimental to the fatigue life at higher line energies. Residual stress analysis showed the amount of stress within the study samples increased with each forming operation. This information was vital in the analysis of the fatigue life of titanium. A fatigue life prediction model was developed from this study and it shed some light on the behaviour of titanium in fatigue testing. The model could be used to predict fatigue life when no fatigue data is available for commercially pure grade 2 titanium alloy plates. In conclusion, this study helped establish parameters that could be used to bend titanium while the analysis of mechanical properties showed the limits of working with this alloy.
- Full Text:
- Date Issued: 2014
Mechanisms, analysis and characterisation of mechanical properties of laser formed commercially pure grade 2 titanium alloy plates
- Authors: Mjali, Kadephi Vuyolwethu
- Date: 2014
- Subjects: Materials -- Mechanical properties , Bending , Titanium-aluminum alloys
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9641 , http://hdl.handle.net/10948/d1021083
- Description: The processing of materials has become a specialist field and the industry will continue to grow due to rising costs in labour and raw materials which has forced many automotive industry suppliers to invest heavily in this field. In order to be relevant and competitive in today’s industrial world, companies in South Africa are now forced to dedicate billions of rands in profits to research and development. Metals like titanium are finding favour with automotive and aviation companies in pursuit of savings in fuel consumption. This saving is achieved by reducing weight on aircraft and automobiles yet still meeting acceptable and improved structural integrity. In-depth research into the behaviour of various materials under varying loading conditions is therefore essential. The study on the processing of commercially pure grade 2 titanium alloy plates focuses on the development of process parameters for bending the material using a 4kW Nd: YAG laser to an approximate radius of curvature of 120mm. The resulting mechanical properties of laser formed plates are then compared to those obtained from mechanically formed samples. The titanium parent material was used to benchmark the performance of formed samples. The effect of process parameters on the mechanical properties and structural integrity also formed part of this study. To obtain the bending parameters for laser forming, various combinations of processing speeds and laser powers were used. The line energy is dependent on the power and scanning velocity parameters and these are shown in table 1. The laser power, line energy and scanning velocity were the main parameters controlled in this study and the beam diameter remained unchanged. Residual stress analysis, micro-hardness and fatigue life testing were carried out to analyse mechanical properties and the structural integrity of the plate samples. Microstructural analysis was also done to observe changes in the material as a result of the forming processes. From the results it is evident that laser forming is beneficial to the hardness of titanium but detrimental to the fatigue life at higher line energies. Residual stress analysis showed the amount of stress within the study samples increased with each forming operation. This information was vital in the analysis of the fatigue life of titanium. A fatigue life prediction model was developed from this study and it shed some light on the behaviour of titanium in fatigue testing. The model could be used to predict fatigue life when no fatigue data is available for commercially pure grade 2 titanium alloy plates. In conclusion, this study helped establish parameters that could be used to bend titanium while the analysis of mechanical properties showed the limits of working with this alloy.
- Full Text:
- Date Issued: 2014
- Authors: Mjali, Kadephi Vuyolwethu
- Date: 2014
- Subjects: Materials -- Mechanical properties , Bending , Titanium-aluminum alloys
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9641 , http://hdl.handle.net/10948/d1021083
- Description: The processing of materials has become a specialist field and the industry will continue to grow due to rising costs in labour and raw materials which has forced many automotive industry suppliers to invest heavily in this field. In order to be relevant and competitive in today’s industrial world, companies in South Africa are now forced to dedicate billions of rands in profits to research and development. Metals like titanium are finding favour with automotive and aviation companies in pursuit of savings in fuel consumption. This saving is achieved by reducing weight on aircraft and automobiles yet still meeting acceptable and improved structural integrity. In-depth research into the behaviour of various materials under varying loading conditions is therefore essential. The study on the processing of commercially pure grade 2 titanium alloy plates focuses on the development of process parameters for bending the material using a 4kW Nd: YAG laser to an approximate radius of curvature of 120mm. The resulting mechanical properties of laser formed plates are then compared to those obtained from mechanically formed samples. The titanium parent material was used to benchmark the performance of formed samples. The effect of process parameters on the mechanical properties and structural integrity also formed part of this study. To obtain the bending parameters for laser forming, various combinations of processing speeds and laser powers were used. The line energy is dependent on the power and scanning velocity parameters and these are shown in table 1. The laser power, line energy and scanning velocity were the main parameters controlled in this study and the beam diameter remained unchanged. Residual stress analysis, micro-hardness and fatigue life testing were carried out to analyse mechanical properties and the structural integrity of the plate samples. Microstructural analysis was also done to observe changes in the material as a result of the forming processes. From the results it is evident that laser forming is beneficial to the hardness of titanium but detrimental to the fatigue life at higher line energies. Residual stress analysis showed the amount of stress within the study samples increased with each forming operation. This information was vital in the analysis of the fatigue life of titanium. A fatigue life prediction model was developed from this study and it shed some light on the behaviour of titanium in fatigue testing. The model could be used to predict fatigue life when no fatigue data is available for commercially pure grade 2 titanium alloy plates. In conclusion, this study helped establish parameters that could be used to bend titanium while the analysis of mechanical properties showed the limits of working with this alloy.
- Full Text:
- Date Issued: 2014
Problems experienced by project managers on housing projects
- Mtshekexe, Ntombesibini Octavia
- Authors: Mtshekexe, Ntombesibini Octavia
- Date: 2014
- Subjects: Project management , Housing rehabilitation , Public housing -- South Africa , Building -- Superintendence
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9675 , http://hdl.handle.net/10948/d1020930
- Description: Housing projects are amongst the South African (SA) Government’s major focus points with reference to budgeting for its financial years. The delivery of these housing projects is taking place at a slower rate than anticipated due to the problems experienced in the processes involved in their management. The project management shortcomings are a major setback with reference to the delivery of houses to the communities. It is, however, stated by the Constitution of the Republic of South Africa (RSA) that every South African citizen has a right to housing and that the Local Government, as the closest entity to communities, must do whatever it possibly can to ensure timeous service delivery to its communities. The objective of this research is to ascertain the nature and extent of project management problems experienced by municipal project managers, the impact thereof and potential solutions to the identified problems. The study is intended to advise on possible ways to address project management problems arising during the implementation of housing projects in the Nelson Mandela Bay Municipality (NMBM) through investigation and analysis of information gathered in both theory and practice. Project management is a process of controlling the achievement of project objectives through the application of knowledge, skills, tools and techniques. For a housing project the main objective is to deliver safe, quality houses on time and within budget. Problems which hinder the delivery of housing projects relate to cost, time and the quality of housing projects delivered. The fact that these key project objectives are not met needs to be addressed urgently in order to improve the housing delivery. The literature reviewed and the feedback from the surveys; indicate that these problems have a vast impact on housing projects. The survey also reveals that it is not only housing Project Managers (PMs) that are unable to perform well, but also other parties involved in the project management of housing projects and which play a great role in project management failures of housing projects. Some of these parties are consultants and contractors. The lack of performance by project managers affects the delivery of houses negatively in the NMBM.
- Full Text:
- Date Issued: 2014
- Authors: Mtshekexe, Ntombesibini Octavia
- Date: 2014
- Subjects: Project management , Housing rehabilitation , Public housing -- South Africa , Building -- Superintendence
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9675 , http://hdl.handle.net/10948/d1020930
- Description: Housing projects are amongst the South African (SA) Government’s major focus points with reference to budgeting for its financial years. The delivery of these housing projects is taking place at a slower rate than anticipated due to the problems experienced in the processes involved in their management. The project management shortcomings are a major setback with reference to the delivery of houses to the communities. It is, however, stated by the Constitution of the Republic of South Africa (RSA) that every South African citizen has a right to housing and that the Local Government, as the closest entity to communities, must do whatever it possibly can to ensure timeous service delivery to its communities. The objective of this research is to ascertain the nature and extent of project management problems experienced by municipal project managers, the impact thereof and potential solutions to the identified problems. The study is intended to advise on possible ways to address project management problems arising during the implementation of housing projects in the Nelson Mandela Bay Municipality (NMBM) through investigation and analysis of information gathered in both theory and practice. Project management is a process of controlling the achievement of project objectives through the application of knowledge, skills, tools and techniques. For a housing project the main objective is to deliver safe, quality houses on time and within budget. Problems which hinder the delivery of housing projects relate to cost, time and the quality of housing projects delivered. The fact that these key project objectives are not met needs to be addressed urgently in order to improve the housing delivery. The literature reviewed and the feedback from the surveys; indicate that these problems have a vast impact on housing projects. The survey also reveals that it is not only housing Project Managers (PMs) that are unable to perform well, but also other parties involved in the project management of housing projects and which play a great role in project management failures of housing projects. Some of these parties are consultants and contractors. The lack of performance by project managers affects the delivery of houses negatively in the NMBM.
- Full Text:
- Date Issued: 2014
SecMVC : a model for secure software design based on the model-view-controller pattern
- Authors: Colesky, Michael Robert
- Date: 2014
- Subjects: Computer networks -- Security measures -- Software , Computer software -- Development , Model-driven software architecture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9823 , http://hdl.handle.net/10948/d1020614
- Description: Current advances in the software development industry are growing more ubiquitous by the day. This has caused for security, not only in the broader sense, but specifically within the design and overall development of software itself, to become all the more important. An evidently prevalent problem in the domain of software development is that software security is not consistently addressed during design, which undermines core security concerns, and leads to the development of insecure software. This research seeks to address this issue via a model for secure software design, which is based on a software design pattern, namely, the Model-View-Controller (MVC) pattern. The use of a pattern to convey knowledge is not a new notion. However, the ability of software design patterns to convey secure software design is an idea worth investigating. Following identification of secure software design principles and concepts, as well as software design patterns, specifically those relating to the MVC pattern, a model was designed and developed. With the MVC pattern argued as being a suitable foundation for the model, the security conscious MVC (SecMVC) combines secure software design principles and concepts into the MVC pattern. Together herewith, the MVC pattern’s components in the MVC Compound pattern, namely: the Observer pattern, the Strategy pattern, and the Composite pattern, have provided further sub-models for less abstraction and greater detail. These sub-models were developed, as a result of the SecMVC model’s evaluation in the validation for this study, an expert review. Argued in the light of similar research methods, the expert review was chosen – along with a process that included the use of two expert participants to validate the SecMVC model. It was determined through the expert review that the SecMVC model is of sufficient utility, quality, and efficacy to constitute research value. The research methodology process followed was design science, in which the SecMVC model, which includes its related sub-models, serves as the artefact and research output of this study. This research study contributes evidence of the feasibility for integrating knowledge into software design patterns. This includes the SecMVC model itself. In addition, it argues for the use of an expert review, as an evaluative research method for such an artifact.
- Full Text:
- Date Issued: 2014
- Authors: Colesky, Michael Robert
- Date: 2014
- Subjects: Computer networks -- Security measures -- Software , Computer software -- Development , Model-driven software architecture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9823 , http://hdl.handle.net/10948/d1020614
- Description: Current advances in the software development industry are growing more ubiquitous by the day. This has caused for security, not only in the broader sense, but specifically within the design and overall development of software itself, to become all the more important. An evidently prevalent problem in the domain of software development is that software security is not consistently addressed during design, which undermines core security concerns, and leads to the development of insecure software. This research seeks to address this issue via a model for secure software design, which is based on a software design pattern, namely, the Model-View-Controller (MVC) pattern. The use of a pattern to convey knowledge is not a new notion. However, the ability of software design patterns to convey secure software design is an idea worth investigating. Following identification of secure software design principles and concepts, as well as software design patterns, specifically those relating to the MVC pattern, a model was designed and developed. With the MVC pattern argued as being a suitable foundation for the model, the security conscious MVC (SecMVC) combines secure software design principles and concepts into the MVC pattern. Together herewith, the MVC pattern’s components in the MVC Compound pattern, namely: the Observer pattern, the Strategy pattern, and the Composite pattern, have provided further sub-models for less abstraction and greater detail. These sub-models were developed, as a result of the SecMVC model’s evaluation in the validation for this study, an expert review. Argued in the light of similar research methods, the expert review was chosen – along with a process that included the use of two expert participants to validate the SecMVC model. It was determined through the expert review that the SecMVC model is of sufficient utility, quality, and efficacy to constitute research value. The research methodology process followed was design science, in which the SecMVC model, which includes its related sub-models, serves as the artefact and research output of this study. This research study contributes evidence of the feasibility for integrating knowledge into software design patterns. This includes the SecMVC model itself. In addition, it argues for the use of an expert review, as an evaluative research method for such an artifact.
- Full Text:
- Date Issued: 2014
The effects of shot peening on low cycle fatigue life of 7075-T6 aluminium alloy round bar
- Authors: Peters, Donald Michael Dirk
- Date: 2014
- Subjects: Shot peening , Aluminum alloys -- Fatigue , Metals -- Fatigue
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/2929 , vital:20364
- Description: The aim in this dissertation was to improve our understanding of the effectiveness of shot peening in prolonging fatigue life, of 7075-T6 Aluminium Alloy round bar, taking into consideration surface residual stress, microstructural and micro-hardness parameters. Three point bending, high stress, moderately low cycle, fatigue tests were conducted to study the effects of shot peening and associated surface residual compressive stresses on fatigue life. The influence of shot peening on the microstructure was explored, including the application of mechanical small plastic straining and surface skimming, to vary the surface residual compressive stresses and induce strain hardening. Tests were performed to measure residual stress-depth distribution, plastic straining, micro-hardness, and the microstructure analysed on scanning electron microscopy (SEM) fractographs. The Juvinall and Marshek life prediction model was used in conjunction with the Gerber equation for non-zero mean stress applications to generate a proposed life prediction model for this material which is user-friendly. The proposed life prediction model has a linear equation format with the flexibility to conservatively accommodate most of the various types, and combinations, of treatments applied in this research by the use of customised constants. The results show that there was good correlation between actual and predicted fatigue life as well as useful insights into the role of the microstructure in explaining fatigue life behaviour.
- Full Text:
- Date Issued: 2014
- Authors: Peters, Donald Michael Dirk
- Date: 2014
- Subjects: Shot peening , Aluminum alloys -- Fatigue , Metals -- Fatigue
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/2929 , vital:20364
- Description: The aim in this dissertation was to improve our understanding of the effectiveness of shot peening in prolonging fatigue life, of 7075-T6 Aluminium Alloy round bar, taking into consideration surface residual stress, microstructural and micro-hardness parameters. Three point bending, high stress, moderately low cycle, fatigue tests were conducted to study the effects of shot peening and associated surface residual compressive stresses on fatigue life. The influence of shot peening on the microstructure was explored, including the application of mechanical small plastic straining and surface skimming, to vary the surface residual compressive stresses and induce strain hardening. Tests were performed to measure residual stress-depth distribution, plastic straining, micro-hardness, and the microstructure analysed on scanning electron microscopy (SEM) fractographs. The Juvinall and Marshek life prediction model was used in conjunction with the Gerber equation for non-zero mean stress applications to generate a proposed life prediction model for this material which is user-friendly. The proposed life prediction model has a linear equation format with the flexibility to conservatively accommodate most of the various types, and combinations, of treatments applied in this research by the use of customised constants. The results show that there was good correlation between actual and predicted fatigue life as well as useful insights into the role of the microstructure in explaining fatigue life behaviour.
- Full Text:
- Date Issued: 2014
The effects of the labour skills shortage in the construction industry
- Authors: Vanqa, Inga Bongo
- Date: 2014
- Subjects: Construction industry -- South Africa , Building trades -- Employees , Skilled labor -- South Africa , Labor supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9728 , http://hdl.handle.net/10948/d1021125
- Description: Purpose of this treatise: The aim of this research is to determine, if the skilled labour shortage has had any impact on how construction projects are executed. If there is an impact the study aims to determine the nature and extent of the problem. Design/methodology/approach: A review of related literature was conducted, mainly to ensure that existing research is not replicated, in order to generate new ideas. The quantitative research approach was applied for this research. The questionnaire was designed so that scores can be easily summed in order to obtain an overall measure of the attitudes and opinions of the respondents. Findings: The results revealed that the skilled labour shortage has a negative effect on how construction projects are executed. The results further revealed that the biggest concern amongst employers and management of construction companies was the negative impact the shortage of skilled labour has on the levels of workmanship. Research limitations: The sample (construction companies) is mostly situated in the Gauteng province of South Africa. Practical implications: The research is of importance to managers and supervisors of construction companies of all sizes. The findings of this study will assist in ensuring that projects are efficiently managed irrespective of the current skills crisis in the construction industry.
- Full Text:
- Date Issued: 2014
- Authors: Vanqa, Inga Bongo
- Date: 2014
- Subjects: Construction industry -- South Africa , Building trades -- Employees , Skilled labor -- South Africa , Labor supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9728 , http://hdl.handle.net/10948/d1021125
- Description: Purpose of this treatise: The aim of this research is to determine, if the skilled labour shortage has had any impact on how construction projects are executed. If there is an impact the study aims to determine the nature and extent of the problem. Design/methodology/approach: A review of related literature was conducted, mainly to ensure that existing research is not replicated, in order to generate new ideas. The quantitative research approach was applied for this research. The questionnaire was designed so that scores can be easily summed in order to obtain an overall measure of the attitudes and opinions of the respondents. Findings: The results revealed that the skilled labour shortage has a negative effect on how construction projects are executed. The results further revealed that the biggest concern amongst employers and management of construction companies was the negative impact the shortage of skilled labour has on the levels of workmanship. Research limitations: The sample (construction companies) is mostly situated in the Gauteng province of South Africa. Practical implications: The research is of importance to managers and supervisors of construction companies of all sizes. The findings of this study will assist in ensuring that projects are efficiently managed irrespective of the current skills crisis in the construction industry.
- Full Text:
- Date Issued: 2014
The training of artisans for house building projects in South Western Nigeria
- Authors: Oni, Oluwole Joseph
- Date: 2014
- Subjects: Skilled labor -- Nigeria , Artisans -- Training of -- Nigeria , Construction industry -- Employees -- Training of -- Nigeria , Training needs -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9726 , http://hdl.handle.net/10948/d1020625
- Description: The current shortage of artisans in the Nigerian house construction sector has constrained the productivity of the sector and exacerbated the nation‟s housing problem. The persistent neglect of the artisan training system has negatively impacted on the stock of artisans available for house construction projects. Nigeria‟s large and fast-growing population of over 140 million with an estimated growth rate of 3.2 percent has engendered increased investment in shelter provision; especially by individuals and families due to fast rising housing rentals- mainly in the urban centres. Past policies have not adequately addressed the realities of the skills crisis occasioned by inadequate and neglected apprenticeship training and poorly developed vocational education and training systems. The fallout of this is manifested in the difficulties faced by developers in sourcing suitably qualified and experienced artisans for house construction projects. In response to this challenge, an upsurge of migrant artisans and craftsmen from neighbouring West African nations like Togo, Benin Republic and Ghana to Nigeria has occurred in the recent times. They were attracted by building contracting firms to fill the gap created by inadequate artisan supply that is currently being experienced locally. This development is totally unacceptable as it exacerbates the overarching socio-economic problems in Nigeria, especially the already high unemployment rate which is estimated to be 23.9 percent. This study has consequently investigated the inadequate training of house construction artisans in South Western Nigeria; evolving interventions and developing a strategic model for improving the artisan training system to ensure an adequate and sustainable artisan supply in the house construction sector. The model incorporates best practices, rethinking strategies and integrated approaches in mitigating the identified challenges. The model is underpinned by reviewed literature and empirical findings. Quantitative surveys and interviews were utilised as the data sources. The research findings show that the factors which negatively impact on the artisan training system in the house construction sector include: the poor image of artisans in society; lack of recruitment strategies for attracting potential artisans; inadequate policy framework for training and employment; a faulty and rigid National Qualification Framework (NQF); the non-participation of employers in training; a poor funding mechanism; a weak regulatory framework and corrupt practices in training administration. Recommendations for addressing the inadequate training of artisans include education policy reforms to give priority to vocational education; a new regime of funding for vocational education and training; a review of the National Qualification Framework to integrate the vocational colleges with the university system; a reform of the regulatory framework; public re-orientation on the societal image of the artisans; adoption of a new approach of public- private partnership in artisan training; the provision of incentives schemes to attract potential artisans and the appropriation of the proposed model for an integrated approach to addressing the challenges.
- Full Text:
- Date Issued: 2014
- Authors: Oni, Oluwole Joseph
- Date: 2014
- Subjects: Skilled labor -- Nigeria , Artisans -- Training of -- Nigeria , Construction industry -- Employees -- Training of -- Nigeria , Training needs -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9726 , http://hdl.handle.net/10948/d1020625
- Description: The current shortage of artisans in the Nigerian house construction sector has constrained the productivity of the sector and exacerbated the nation‟s housing problem. The persistent neglect of the artisan training system has negatively impacted on the stock of artisans available for house construction projects. Nigeria‟s large and fast-growing population of over 140 million with an estimated growth rate of 3.2 percent has engendered increased investment in shelter provision; especially by individuals and families due to fast rising housing rentals- mainly in the urban centres. Past policies have not adequately addressed the realities of the skills crisis occasioned by inadequate and neglected apprenticeship training and poorly developed vocational education and training systems. The fallout of this is manifested in the difficulties faced by developers in sourcing suitably qualified and experienced artisans for house construction projects. In response to this challenge, an upsurge of migrant artisans and craftsmen from neighbouring West African nations like Togo, Benin Republic and Ghana to Nigeria has occurred in the recent times. They were attracted by building contracting firms to fill the gap created by inadequate artisan supply that is currently being experienced locally. This development is totally unacceptable as it exacerbates the overarching socio-economic problems in Nigeria, especially the already high unemployment rate which is estimated to be 23.9 percent. This study has consequently investigated the inadequate training of house construction artisans in South Western Nigeria; evolving interventions and developing a strategic model for improving the artisan training system to ensure an adequate and sustainable artisan supply in the house construction sector. The model incorporates best practices, rethinking strategies and integrated approaches in mitigating the identified challenges. The model is underpinned by reviewed literature and empirical findings. Quantitative surveys and interviews were utilised as the data sources. The research findings show that the factors which negatively impact on the artisan training system in the house construction sector include: the poor image of artisans in society; lack of recruitment strategies for attracting potential artisans; inadequate policy framework for training and employment; a faulty and rigid National Qualification Framework (NQF); the non-participation of employers in training; a poor funding mechanism; a weak regulatory framework and corrupt practices in training administration. Recommendations for addressing the inadequate training of artisans include education policy reforms to give priority to vocational education; a new regime of funding for vocational education and training; a review of the National Qualification Framework to integrate the vocational colleges with the university system; a reform of the regulatory framework; public re-orientation on the societal image of the artisans; adoption of a new approach of public- private partnership in artisan training; the provision of incentives schemes to attract potential artisans and the appropriation of the proposed model for an integrated approach to addressing the challenges.
- Full Text:
- Date Issued: 2014
A cyber security awareness and education framework for South Africa
- Authors: Kortjan, Noloxolo
- Date: 2013
- Subjects: Computer networks -- Security measures , Computer crimes -- Prevention , Computer security
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9811 , http://hdl.handle.net/10948/d1014829
- Description: The Internet is becoming increasingly interwoven in the daily life of many individuals, organisations and nations. It has, to a large extent, had a positive effect on the way people communicate. It has also introduced new avenues for business and has offered nations an opportunity to govern online. Nevertheless, although cyberspace offers an endless list of services and opportunities, it is also accompanied by many risks. One of these risks is cybercrime. The Internet has given criminals a platform on which to grow and proliferate. As a result of the abstract nature of the Internet, it is easy for these criminals to go unpunished. Moreover, many who use the Internet are not aware of such threats; therefore they may themselves be at risk, together with businesses and governmental assets and infrastructure. In view of this, there is a need for cyber security awareness and education initiatives that will promote users who are well versed in the risks associated with the Internet. In this context, it is the role of the government to empower all levels of society by providing the necessary knowledge and expertise to act securely online. However, there is currently a definite lack in South Africa (SA) in this regard, as there are currently no government-led cyber security awareness and education initiatives. The primary research objective of this study, therefore, is to propose a cyber security awareness and education framework for SA that will assist in creating a cyber secure culture in SA among all of its users of the Internet.
- Full Text:
- Date Issued: 2013
- Authors: Kortjan, Noloxolo
- Date: 2013
- Subjects: Computer networks -- Security measures , Computer crimes -- Prevention , Computer security
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9811 , http://hdl.handle.net/10948/d1014829
- Description: The Internet is becoming increasingly interwoven in the daily life of many individuals, organisations and nations. It has, to a large extent, had a positive effect on the way people communicate. It has also introduced new avenues for business and has offered nations an opportunity to govern online. Nevertheless, although cyberspace offers an endless list of services and opportunities, it is also accompanied by many risks. One of these risks is cybercrime. The Internet has given criminals a platform on which to grow and proliferate. As a result of the abstract nature of the Internet, it is easy for these criminals to go unpunished. Moreover, many who use the Internet are not aware of such threats; therefore they may themselves be at risk, together with businesses and governmental assets and infrastructure. In view of this, there is a need for cyber security awareness and education initiatives that will promote users who are well versed in the risks associated with the Internet. In this context, it is the role of the government to empower all levels of society by providing the necessary knowledge and expertise to act securely online. However, there is currently a definite lack in South Africa (SA) in this regard, as there are currently no government-led cyber security awareness and education initiatives. The primary research objective of this study, therefore, is to propose a cyber security awareness and education framework for SA that will assist in creating a cyber secure culture in SA among all of its users of the Internet.
- Full Text:
- Date Issued: 2013
A framework for assuring conformance of cloud-based email at higher education institutions
- Authors: Willett, Melanie
- Date: 2013
- Subjects: Cloud computing -- Security measures , Computer networks -- Security measures , Web services , Education, Higher -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9815 , http://hdl.handle.net/10948/d1018664
- Description: Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.
- Full Text:
- Date Issued: 2013
- Authors: Willett, Melanie
- Date: 2013
- Subjects: Cloud computing -- Security measures , Computer networks -- Security measures , Web services , Education, Higher -- Technological innovations
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9815 , http://hdl.handle.net/10948/d1018664
- Description: Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.
- Full Text:
- Date Issued: 2013
A framework for biometrics for social grants in South Africa
- Authors: Van de Haar, Helen Augusta
- Date: 2013
- Subjects: Biometric identification -- Law and legislation -- South Africa , Biometric identification cards -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9829 , http://hdl.handle.net/10948/d1021018
- Description: In the South African Social Security Agency (SASSA) Annual Report of 2011/2012 it is stated that there were more than 15 million social grants paid out to needy beneficiaries of which 10 927 731 were Child Support Grants. A major challenge that is continually being addressed is the management and administration of these grants. In particular, the focus is on service delivery and zero tolerance to fraud and corruption. SASSA has made various attempts to address these issues, such as the rollout of biometric smart cards in 2012. This research endeavour attempts to discover whether a framework can be designed where necessary factors are taken into consideration to provide for an efficient social grant application and delivery process that uses biometrics. The framework aims to suggest improvements in the use of biometrics for the social grants. Seeing that biometrics in this case is used as a technology to improve a system involving humans, this study followed a Design Science approach and made use of a case study to collect the data required for the study. Literature studies reviewed the fields of social grants and biometrics. The challenges and lessons learnt from current implementations of social grants and biometrics within the South African context and further abroad were also relevant for the study. The framework that resulted from the above was evaluated for validity and applicability after which a modified framework is presented. The research concludes with specific implementation guidelines as well as areas for future research.
- Full Text:
- Date Issued: 2013
- Authors: Van de Haar, Helen Augusta
- Date: 2013
- Subjects: Biometric identification -- Law and legislation -- South Africa , Biometric identification cards -- South Africa , Public welfare -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9829 , http://hdl.handle.net/10948/d1021018
- Description: In the South African Social Security Agency (SASSA) Annual Report of 2011/2012 it is stated that there were more than 15 million social grants paid out to needy beneficiaries of which 10 927 731 were Child Support Grants. A major challenge that is continually being addressed is the management and administration of these grants. In particular, the focus is on service delivery and zero tolerance to fraud and corruption. SASSA has made various attempts to address these issues, such as the rollout of biometric smart cards in 2012. This research endeavour attempts to discover whether a framework can be designed where necessary factors are taken into consideration to provide for an efficient social grant application and delivery process that uses biometrics. The framework aims to suggest improvements in the use of biometrics for the social grants. Seeing that biometrics in this case is used as a technology to improve a system involving humans, this study followed a Design Science approach and made use of a case study to collect the data required for the study. Literature studies reviewed the fields of social grants and biometrics. The challenges and lessons learnt from current implementations of social grants and biometrics within the South African context and further abroad were also relevant for the study. The framework that resulted from the above was evaluated for validity and applicability after which a modified framework is presented. The research concludes with specific implementation guidelines as well as areas for future research.
- Full Text:
- Date Issued: 2013
A framework to mitigate phishing threats
- Authors: Frauenstein, Edwin Donald
- Date: 2013
- Subjects: Computer networks -- Security measures , Mobile computing -- Security measures , Online social networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9832 , http://hdl.handle.net/10948/d1021208
- Description: We live today in the information age with users being able to access and share information freely by using both personal computers and their handheld devices. This, in turn, has been made possible by the Internet. However, this poses security risks as attempts are made to use this same environment in order to compromise the confidentiality, integrity and availability of information. Accordingly, there is an urgent need for users and organisations to protect their information resources from agents posing a security threat. Organisations typically spend large amounts of money as well as dedicating resources to improve their technological defences against general security threats. However, the agents posing these threats are adopting social engineering techniques in order to bypass the technical measures which organisations are putting in place. These social engineering techniques are often effective because they target human behaviour, something which the majority of researchers believe is a far easier alternative than hacking information systems. As such, phishing effectively makes use of a combination of social engineering techniques which involve crafty technical emails and website designs which gain the trust of their victims. Within an organisational context, there are a number of areas which phishers exploit. These areas include human factors, organisational aspects and technological controls. Ironically, these same areas serve simultaneously as security measures against phishing attacks. However, each of these three areas mentioned above are characterised by gaps which arise as a result of human involvement. As a result, the current approach to mitigating phishing threats comprises a single-layer defence model only. However, this study proposes a holistic model which integrates each of these three areas by strengthening the human element in each of these areas by means of a security awareness, training and education programme.
- Full Text:
- Date Issued: 2013
- Authors: Frauenstein, Edwin Donald
- Date: 2013
- Subjects: Computer networks -- Security measures , Mobile computing -- Security measures , Online social networks -- Security measures
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9832 , http://hdl.handle.net/10948/d1021208
- Description: We live today in the information age with users being able to access and share information freely by using both personal computers and their handheld devices. This, in turn, has been made possible by the Internet. However, this poses security risks as attempts are made to use this same environment in order to compromise the confidentiality, integrity and availability of information. Accordingly, there is an urgent need for users and organisations to protect their information resources from agents posing a security threat. Organisations typically spend large amounts of money as well as dedicating resources to improve their technological defences against general security threats. However, the agents posing these threats are adopting social engineering techniques in order to bypass the technical measures which organisations are putting in place. These social engineering techniques are often effective because they target human behaviour, something which the majority of researchers believe is a far easier alternative than hacking information systems. As such, phishing effectively makes use of a combination of social engineering techniques which involve crafty technical emails and website designs which gain the trust of their victims. Within an organisational context, there are a number of areas which phishers exploit. These areas include human factors, organisational aspects and technological controls. Ironically, these same areas serve simultaneously as security measures against phishing attacks. However, each of these three areas mentioned above are characterised by gaps which arise as a result of human involvement. As a result, the current approach to mitigating phishing threats comprises a single-layer defence model only. However, this study proposes a holistic model which integrates each of these three areas by strengthening the human element in each of these areas by means of a security awareness, training and education programme.
- Full Text:
- Date Issued: 2013
A model for managing user experience
- Authors: Mashapa, Job
- Date: 2013
- Subjects: Technological innovations -- Management , User interfaces (Computer systems)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9826 , http://hdl.handle.net/10948/d1020765
- Description: New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.
- Full Text:
- Date Issued: 2013
- Authors: Mashapa, Job
- Date: 2013
- Subjects: Technological innovations -- Management , User interfaces (Computer systems)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9826 , http://hdl.handle.net/10948/d1020765
- Description: New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.
- Full Text:
- Date Issued: 2013
A strategy to make ICT accessible in rural Zambia: a case study of Macha
- Authors: Van Stam, Gertjan
- Date: 2013
- Subjects: Communication in rural development -- Zambia , Communication and technology -- Zambia
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9830
- Description: The problem discussed in this dissertation is to gather evidence of good practice and derive strategy for the development of ICT access in rural Zambia. Access to ICT services is important, also in rural areas of Africa. The challenges are many. There is a distinct void in tangible descriptions of the realities of ICT Access in rural areas or actionable guidelines for practitioners. This study involves a case study in the rural areas of Zambia. It does so through ethnography involving 10 years of observation of aspects of ICT access in rural Macha, Zambia. In this community, emerging from an articulated vision, ICT access in the form of the Internet arrived in 2004. Macha Works with its ICT unit LinkNet provides the basis for this interpretive approach from within the rural cultural setting. The purpose of the study is to benefit the local rural community, addressing the fundamentals of reality to add to the body of knowledge. The study involves cross cultural interaction and takes a trans-disciplinary view on science. It involves Participative Action Learning and Research aimed at recognising the complex adaptive systems while being aligned with the ethics of the rural African environment. Emphasis is on the needs of the community, rather than of the individual utilising empirical evidence. The good practices in Macha that inform strategy to make ICT accessible in rural areas are: engaging the community, building relationships; workforce development, unlocking productivity; thought leadership, establishing authority.
- Full Text:
- Date Issued: 2013
- Authors: Van Stam, Gertjan
- Date: 2013
- Subjects: Communication in rural development -- Zambia , Communication and technology -- Zambia
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9830
- Description: The problem discussed in this dissertation is to gather evidence of good practice and derive strategy for the development of ICT access in rural Zambia. Access to ICT services is important, also in rural areas of Africa. The challenges are many. There is a distinct void in tangible descriptions of the realities of ICT Access in rural areas or actionable guidelines for practitioners. This study involves a case study in the rural areas of Zambia. It does so through ethnography involving 10 years of observation of aspects of ICT access in rural Macha, Zambia. In this community, emerging from an articulated vision, ICT access in the form of the Internet arrived in 2004. Macha Works with its ICT unit LinkNet provides the basis for this interpretive approach from within the rural cultural setting. The purpose of the study is to benefit the local rural community, addressing the fundamentals of reality to add to the body of knowledge. The study involves cross cultural interaction and takes a trans-disciplinary view on science. It involves Participative Action Learning and Research aimed at recognising the complex adaptive systems while being aligned with the ethics of the rural African environment. Emphasis is on the needs of the community, rather than of the individual utilising empirical evidence. The good practices in Macha that inform strategy to make ICT accessible in rural areas are: engaging the community, building relationships; workforce development, unlocking productivity; thought leadership, establishing authority.
- Full Text:
- Date Issued: 2013
A value framework for information and communication technology governance in South African higher education institutions
- Authors: Johl, Christian Peter
- Date: 2013
- Subjects: Information technology -- South Africa -- Management , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9821 , http://hdl.handle.net/10948/d1020281
- Description: The public higher education sector in South Africa is governed by an act of Parliament which defines the governance organs and mechanisms required within institutions and the sector. This doctoral thesis begins by contextualising ICT governance within the levels of systemic governance in South Africa that have relevance to this study. It then continues by advancing the understanding of the state of Information and Communication Technology (ICT) governance in public higher education institutions in South Africa by investigating the level of pervasiveness, the level of ICT process maturity and the alignment of ICT to the institutional processes within these institutions. Subsequently, this thesis results in the production of a contextually appropriate value framework that contributes towards an understanding of the need for the improvement of ICT governance. A survey of the extant literature on governance, ICT governance, and the frameworks and standards associated with governance indicates that the methodological approach currently favoured in ICT governance research is predominantly interpretive and based on surveys and interviews. This study leans towards a Design Science approach paradigm using surveys for the qualitative data collection process. The empirical research data was gathered from the highest ranking ICT officers at public higher education institutions in South Africa. This study makes contributions on a number of levels – from the first known measurement of ICT pervasiveness within the context of higher education, to the measurement of ICT process maturity and the measurement of the alignment of ICT and institutional processes, to the design of a value framework that breaks down governance into layers indicating which governance organs are appropriate at the relevant layers and which governance mechanisms can be used to address governance at each layer of governance. This study therefore makes a contribution to the ICT domain for development research by demonstrating praxis for the improvement of ICT governance implementation in the public higher education sector in South Africa. This study makes both method design and practical contributions to the ICT body of knowledge at various stages of the research process. These contributions include reflection on and analysis of the data gathering approaches that occur within the public higher education sector and in the complex environment of institutional autonomy and academic freedom; the use of Agency Theory to support the ‗governance intent‘ transfer between the layers of governance in the value framework and the synthesis of the improvement of ICT governance with value creation. The findings of this study further contribute to an understanding of the dynamics and interrelatedness of aspects of governance and management, while making a contribution to theoretical research by extending practical and empirical understanding of the ICT governance environment in the public higher education sector in South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Johl, Christian Peter
- Date: 2013
- Subjects: Information technology -- South Africa -- Management , Universities and colleges -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9821 , http://hdl.handle.net/10948/d1020281
- Description: The public higher education sector in South Africa is governed by an act of Parliament which defines the governance organs and mechanisms required within institutions and the sector. This doctoral thesis begins by contextualising ICT governance within the levels of systemic governance in South Africa that have relevance to this study. It then continues by advancing the understanding of the state of Information and Communication Technology (ICT) governance in public higher education institutions in South Africa by investigating the level of pervasiveness, the level of ICT process maturity and the alignment of ICT to the institutional processes within these institutions. Subsequently, this thesis results in the production of a contextually appropriate value framework that contributes towards an understanding of the need for the improvement of ICT governance. A survey of the extant literature on governance, ICT governance, and the frameworks and standards associated with governance indicates that the methodological approach currently favoured in ICT governance research is predominantly interpretive and based on surveys and interviews. This study leans towards a Design Science approach paradigm using surveys for the qualitative data collection process. The empirical research data was gathered from the highest ranking ICT officers at public higher education institutions in South Africa. This study makes contributions on a number of levels – from the first known measurement of ICT pervasiveness within the context of higher education, to the measurement of ICT process maturity and the measurement of the alignment of ICT and institutional processes, to the design of a value framework that breaks down governance into layers indicating which governance organs are appropriate at the relevant layers and which governance mechanisms can be used to address governance at each layer of governance. This study therefore makes a contribution to the ICT domain for development research by demonstrating praxis for the improvement of ICT governance implementation in the public higher education sector in South Africa. This study makes both method design and practical contributions to the ICT body of knowledge at various stages of the research process. These contributions include reflection on and analysis of the data gathering approaches that occur within the public higher education sector and in the complex environment of institutional autonomy and academic freedom; the use of Agency Theory to support the ‗governance intent‘ transfer between the layers of governance in the value framework and the synthesis of the improvement of ICT governance with value creation. The findings of this study further contribute to an understanding of the dynamics and interrelatedness of aspects of governance and management, while making a contribution to theoretical research by extending practical and empirical understanding of the ICT governance environment in the public higher education sector in South Africa.
- Full Text:
- Date Issued: 2013