A comparative study of CERBER, MAKTUB and LOCKY Ransomware using a Hybridised-Malware analysis
- Authors: Schmitt, Veronica
- Date: 2019
- Subjects: Microsoft Windows (Computer file) , Data protection , Computer crimes -- Prevention , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92313 , vital:30702
- Description: There has been a significant increase in the prevalence of Ransomware attacks in the preceding four years to date. This indicates that the battle has not yet been won defending against this class of malware. This research proposes that by identifying the similarities within the operational framework of Ransomware strains, a better overall understanding of their operation and function can be achieved. This, in turn, will aid in a quicker response to future attacks. With the average Ransomware attack taking two hours to be identified, it shows that there is not yet a clear understanding as to why these attacks are so successful. Research into Ransomware is limited by what is currently known on the topic. Due to the limitations of the research the decision was taken to only examined three samples of Ransomware from different families. This was decided due to the complexities and comprehensive nature of the research. The in depth nature of the research and the time constraints associated with it did not allow for proof of concept of this framework to be tested on more than three families, but the exploratory work was promising and should be further explored in future research. The aim of the research is to follow the Hybrid-Malware analysis framework which consists of both static and the dynamic analysis phases, in addition to the digital forensic examination of the infected system. This allows for signature-based findings, along with behavioural and forensic findings all in one. This information allows for a better understanding of how this malware is designed and how it infects and remains persistent on a system. The operating system which has been chosen is the Microsoft Window 7 operating system which is still utilised by a significant proportion of Windows users especially in the corporate environment. The experiment process was designed to enable the researcher the ability to collect information regarding the Ransomware and every aspect of its behaviour and communication on a target system. The results can be compared across the three strains to identify the commonalities. The initial hypothesis was that Ransomware variants are all much like an instant cake box consists of specific building blocks which remain the same with the flavouring of the cake mix being the unique feature.
- Full Text:
- Date Issued: 2019
- Authors: Schmitt, Veronica
- Date: 2019
- Subjects: Microsoft Windows (Computer file) , Data protection , Computer crimes -- Prevention , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92313 , vital:30702
- Description: There has been a significant increase in the prevalence of Ransomware attacks in the preceding four years to date. This indicates that the battle has not yet been won defending against this class of malware. This research proposes that by identifying the similarities within the operational framework of Ransomware strains, a better overall understanding of their operation and function can be achieved. This, in turn, will aid in a quicker response to future attacks. With the average Ransomware attack taking two hours to be identified, it shows that there is not yet a clear understanding as to why these attacks are so successful. Research into Ransomware is limited by what is currently known on the topic. Due to the limitations of the research the decision was taken to only examined three samples of Ransomware from different families. This was decided due to the complexities and comprehensive nature of the research. The in depth nature of the research and the time constraints associated with it did not allow for proof of concept of this framework to be tested on more than three families, but the exploratory work was promising and should be further explored in future research. The aim of the research is to follow the Hybrid-Malware analysis framework which consists of both static and the dynamic analysis phases, in addition to the digital forensic examination of the infected system. This allows for signature-based findings, along with behavioural and forensic findings all in one. This information allows for a better understanding of how this malware is designed and how it infects and remains persistent on a system. The operating system which has been chosen is the Microsoft Window 7 operating system which is still utilised by a significant proportion of Windows users especially in the corporate environment. The experiment process was designed to enable the researcher the ability to collect information regarding the Ransomware and every aspect of its behaviour and communication on a target system. The results can be compared across the three strains to identify the commonalities. The initial hypothesis was that Ransomware variants are all much like an instant cake box consists of specific building blocks which remain the same with the flavouring of the cake mix being the unique feature.
- Full Text:
- Date Issued: 2019
A crowdsensing method for water resource monitoring in smart communities
- Authors: Banda, Clara Mloza
- Date: 2019
- Subjects: Data collection platforms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42449 , vital:36658
- Description: Crowdsensing aims to empower a large group of individuals to collect large amounts of data using their mobile devices, with the goal of sharing the collected data. Existing crowdsensing studies do not consider all the activities and methods of the crowdsensing process and the key success factors related to the process. Nor do they investigate the profile and behaviour of potential participants. The aim of this study was to design a crowdsensing method for water resource monitoring in smart communities. This study opted for an exploratory study using the Engaged Scholarship approach, which allows the study of complex real-world problems based on the different perspectives of key stakeholders. The proposed Crowdsensing Method considers the social, technical and programme design components. The study proposes a programme design for the Crowdsensing Methodwhich is crowdsensing ReferenceFrameworkthat includes Crowdsensing Processwith key success factors and guidelines that should be considered in each phase of the process. The method also uses the Theory of Planned Behaviour (TPB) to investigate citizens’intention to participate in crowdsensing for water resource monitoring and explores their attitudes, norms and perceived behavioural control on these intentions. Understanding the profiles of potential participants can assist with designing crowdsensing systems with appropriate incentive mechanisms to achieve adequate user participation and good service quality. A survey was conducted to validate the theoretical TB model in a real-world context. Regression and correlation analyses demonstrated that the attitudes, norms and perceived behavioural control can be used to predict participants’ intention to participate in crowdsensing for water resource monitoring. The survey results assisted with the development of an Incentive Mechanism as part of the Crowdsensing Method. This mechanism incorporates recruitment and incentive policies, as well as guidelines derived from the literature review and extant system analysis. The policies, called the OverSensepolicies, provide guidance for recruitment and rewarding of participants using the popular Stackelberg technique. The policies were evaluated using simulation experiments with a data set provided by the case study, the Nelson Mandela Bay Municipality. The results of the simulation experiments illustrated that the OverSenserecruitmentpolicycan reduce the computing resources required for the recruitment of participants and that the recruitment policy performs better than random or naïve recruitment policies. The proposed Crowdsensing Method was evaluated using an ecosystem of success factors for mobile-based interventions identified in the literature and the Crowdsensing Method adhered to a majority (90%) of the success factors. This study also contributes information systems design theory by proposing several sets of guidelines for crowdsensing projects and the development of crowdsensing systems. This study fulfils an identified need to study the applicability of crowdsensing for water resource monitoring and explores how a crowdsensing method can create a smart community.
- Full Text:
- Date Issued: 2019
- Authors: Banda, Clara Mloza
- Date: 2019
- Subjects: Data collection platforms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42449 , vital:36658
- Description: Crowdsensing aims to empower a large group of individuals to collect large amounts of data using their mobile devices, with the goal of sharing the collected data. Existing crowdsensing studies do not consider all the activities and methods of the crowdsensing process and the key success factors related to the process. Nor do they investigate the profile and behaviour of potential participants. The aim of this study was to design a crowdsensing method for water resource monitoring in smart communities. This study opted for an exploratory study using the Engaged Scholarship approach, which allows the study of complex real-world problems based on the different perspectives of key stakeholders. The proposed Crowdsensing Method considers the social, technical and programme design components. The study proposes a programme design for the Crowdsensing Methodwhich is crowdsensing ReferenceFrameworkthat includes Crowdsensing Processwith key success factors and guidelines that should be considered in each phase of the process. The method also uses the Theory of Planned Behaviour (TPB) to investigate citizens’intention to participate in crowdsensing for water resource monitoring and explores their attitudes, norms and perceived behavioural control on these intentions. Understanding the profiles of potential participants can assist with designing crowdsensing systems with appropriate incentive mechanisms to achieve adequate user participation and good service quality. A survey was conducted to validate the theoretical TB model in a real-world context. Regression and correlation analyses demonstrated that the attitudes, norms and perceived behavioural control can be used to predict participants’ intention to participate in crowdsensing for water resource monitoring. The survey results assisted with the development of an Incentive Mechanism as part of the Crowdsensing Method. This mechanism incorporates recruitment and incentive policies, as well as guidelines derived from the literature review and extant system analysis. The policies, called the OverSensepolicies, provide guidance for recruitment and rewarding of participants using the popular Stackelberg technique. The policies were evaluated using simulation experiments with a data set provided by the case study, the Nelson Mandela Bay Municipality. The results of the simulation experiments illustrated that the OverSenserecruitmentpolicycan reduce the computing resources required for the recruitment of participants and that the recruitment policy performs better than random or naïve recruitment policies. The proposed Crowdsensing Method was evaluated using an ecosystem of success factors for mobile-based interventions identified in the literature and the Crowdsensing Method adhered to a majority (90%) of the success factors. This study also contributes information systems design theory by proposing several sets of guidelines for crowdsensing projects and the development of crowdsensing systems. This study fulfils an identified need to study the applicability of crowdsensing for water resource monitoring and explores how a crowdsensing method can create a smart community.
- Full Text:
- Date Issued: 2019
A deep learning approach to classifying tyres using sidewall images
- Authors: Gifford, Dean
- Date: 2019
- Subjects: Image processing -- Digital techniques , Image processing Computer science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39720 , vital:35351
- Description: End of Life Tyres (ELT's) pose a potential health and environmental risk when dumped in illegal stockpiles. For recycling to be considered feasible, a profitable business opportunity needs to be created. One method of making the recycling process of tyres more profitable is by understanding the compounds found within each tyre. This study aims at classifying these tyres in order to achieve this knowledge. A literature review was done to investigate neural networks, convolutional neural networks as well as existing deep learning architectures for image classification. A deep learning approach was applied in order to classify the logos of tyres as these approaches have proved their success in both image classification and more specifically logo classification. Although tyre classification has been implemented in the past, a deep learning approach has not been applied and the logo has not been the classifying element in any other studies. The main difference of this study compared to previous research surrounding deep learning and logo classification is the properties of the tyre logo. Logos on tyres are very similar in colour as they are purely formed in rubber and very seldom have any colour to them. Additionally, the embossed logos can contain variation among same branded tyres due to small inconsistencies in the moulds. The implementation of this deep learning solution saw multiple convolutional neural networks implemented. Some of these architectures were also implemented using transferred learning. The metrics obtained as outputs from training and testing the architectures were the accuracy, precision, recall, and F1-score. These metrics were compared in conjunction with the confusion matrix produced from testing. To ensure that variance was accounted for in the experiments, the k-fold cross-validation technique was adopted. The results of this study identified that one convolutional neural network model, MobileNet, was particularly well suited for the context of classifying logos on tyre sidewalls. The MobileNet architecture had the highest performance metrics for both training from scratch (96.7% accuracy) and transferred learning (98.8% accuracy). Three other models performed particularly well when trained from scratch, these were a modification of the LeNet architecture, ResNet50 and InceptionV3. The transferred learning results were also impressive with four out of the 5 models achieving an accuracy above 94%. Interestingly, the ResNet50 architecture failed to train when transferred learning was applied. Contrasting to this, the two models VGG16 and VGG19 failed to train when trained from scratch but performed equally as well as the other models when transferred learning was implemented. This indicates that although transferred learning can improve the performance of models, it is highly dependent on the task as well as the model. Overall the results obtained proved that a deep learning approach could be applied in order to classify tyres accurately.
- Full Text:
- Date Issued: 2019
- Authors: Gifford, Dean
- Date: 2019
- Subjects: Image processing -- Digital techniques , Image processing Computer science
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39720 , vital:35351
- Description: End of Life Tyres (ELT's) pose a potential health and environmental risk when dumped in illegal stockpiles. For recycling to be considered feasible, a profitable business opportunity needs to be created. One method of making the recycling process of tyres more profitable is by understanding the compounds found within each tyre. This study aims at classifying these tyres in order to achieve this knowledge. A literature review was done to investigate neural networks, convolutional neural networks as well as existing deep learning architectures for image classification. A deep learning approach was applied in order to classify the logos of tyres as these approaches have proved their success in both image classification and more specifically logo classification. Although tyre classification has been implemented in the past, a deep learning approach has not been applied and the logo has not been the classifying element in any other studies. The main difference of this study compared to previous research surrounding deep learning and logo classification is the properties of the tyre logo. Logos on tyres are very similar in colour as they are purely formed in rubber and very seldom have any colour to them. Additionally, the embossed logos can contain variation among same branded tyres due to small inconsistencies in the moulds. The implementation of this deep learning solution saw multiple convolutional neural networks implemented. Some of these architectures were also implemented using transferred learning. The metrics obtained as outputs from training and testing the architectures were the accuracy, precision, recall, and F1-score. These metrics were compared in conjunction with the confusion matrix produced from testing. To ensure that variance was accounted for in the experiments, the k-fold cross-validation technique was adopted. The results of this study identified that one convolutional neural network model, MobileNet, was particularly well suited for the context of classifying logos on tyre sidewalls. The MobileNet architecture had the highest performance metrics for both training from scratch (96.7% accuracy) and transferred learning (98.8% accuracy). Three other models performed particularly well when trained from scratch, these were a modification of the LeNet architecture, ResNet50 and InceptionV3. The transferred learning results were also impressive with four out of the 5 models achieving an accuracy above 94%. Interestingly, the ResNet50 architecture failed to train when transferred learning was applied. Contrasting to this, the two models VGG16 and VGG19 failed to train when trained from scratch but performed equally as well as the other models when transferred learning was implemented. This indicates that although transferred learning can improve the performance of models, it is highly dependent on the task as well as the model. Overall the results obtained proved that a deep learning approach could be applied in order to classify tyres accurately.
- Full Text:
- Date Issued: 2019
A framework for scoring and tagging NetFlow data
- Authors: Sweeney, Michael John
- Date: 2019
- Subjects: NetFlow , Big data , High performance computing , Event processing (Computer science)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65022 , vital:28654
- Description: With the increase in link speeds and the growth of the Internet, the volume of NetFlow data generated has increased significantly over time and processing these volumes has become a challenge, more specifically a Big Data challenge. With the advent of technologies and architectures designed to handle Big Data volumes, researchers have investigated their application to the processing of NetFlow data. This work builds on prior work wherein a scoring methodology was proposed for identifying anomalies in NetFlow by proposing and implementing a system that allows for automatic, real-time scoring through the adoption of Big Data stream processing architectures. The first part of the research looks at the means of event detection using the scoring approach and implementing as a number of individual, standalone components, each responsible for detecting and scoring a single type of flow trait. The second part is the implementation of these scoring components in a framework, named Themis1, capable of handling high volumes of data with low latency processing times. This was tackled using tools, technologies and architectural elements from the world of Big Data stream processing. The performance of the framework on the stream processing architecture was shown to demonstrate good flow throughput at low processing latencies on a single low end host. The successful demonstration of the framework on a single host opens the way to leverage the scaling capabilities afforded by the architectures and technologies used. This gives weight to the possibility of using this framework for real time threat detection using NetFlow data from larger networked environments.
- Full Text:
- Date Issued: 2019
- Authors: Sweeney, Michael John
- Date: 2019
- Subjects: NetFlow , Big data , High performance computing , Event processing (Computer science)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/65022 , vital:28654
- Description: With the increase in link speeds and the growth of the Internet, the volume of NetFlow data generated has increased significantly over time and processing these volumes has become a challenge, more specifically a Big Data challenge. With the advent of technologies and architectures designed to handle Big Data volumes, researchers have investigated their application to the processing of NetFlow data. This work builds on prior work wherein a scoring methodology was proposed for identifying anomalies in NetFlow by proposing and implementing a system that allows for automatic, real-time scoring through the adoption of Big Data stream processing architectures. The first part of the research looks at the means of event detection using the scoring approach and implementing as a number of individual, standalone components, each responsible for detecting and scoring a single type of flow trait. The second part is the implementation of these scoring components in a framework, named Themis1, capable of handling high volumes of data with low latency processing times. This was tackled using tools, technologies and architectural elements from the world of Big Data stream processing. The performance of the framework on the stream processing architecture was shown to demonstrate good flow throughput at low processing latencies on a single low end host. The successful demonstration of the framework on a single host opens the way to leverage the scaling capabilities afforded by the architectures and technologies used. This gives weight to the possibility of using this framework for real time threat detection using NetFlow data from larger networked environments.
- Full Text:
- Date Issued: 2019
A gatherer's paradise? Early humans and plant foraging on the cape south coast, South Africa
- Authors: Gummow, William Thomas
- Date: 2019
- Subjects: Soil amendments , Plants -- Nutrition Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39687 , vital:35348
- Description: South Africa is a semi-arid country that is experiencing population growth and the associated pressure of producing sufficient crops to sustain the population. Furthermore, poor land management has also led to increased degradation of valuable arable land. To improve poor soil quality and possibly avoid or reverse degradation and ultimately desertification, it was suggested that soil amendments are a potential solution to some of these problems. Although soil amendment is a relatively well-known practice to improve soil quality, the use of rubber crumb as a soil amendment is not well studied. Rubber crumb is produced from end-of-life tyres that have been ground up to fine particles and as such can be used as a secondary resource to replace the use of virgin materials. Rubber crumb has been used in an array of industries, however, the present study investigated the possibility that rubber crumb might be used as a soil amendment to alleviate various forms of soil degradation, specifically soil compaction and crusting, and potentially improve crop establishment and growth.To determine this, a soil that is prone to crusting and compaction was amended with rubber crumb at rates of 5%, 15% and 25%. Various soil physical characteristics, such as bulk density, particle density, porosity, field capacity and penetration resistance were investigated and it was determined that as the percentage rubber crumb increases in the soil, so do the beneficial characteristics of the soil. Furthermore, the rubber crumb was also treated in various ways in order to determine how the treatments might affect the chemical properties of the soil, as well as the amount of zinc that is leached from the rubber crumb. It was found that washing the rubber with a weak acid or even water prior to adding it to the soil resulted in more desirable chemical condition compared to untreated rubber crumb. Lastly, maize (Zea mays L.) was used to determine whether amending soil with pre-treated rubber crumb in different percentages had an influence on the germination success and growth rate of maize. In terms of germination success, amending soil with rubber crumb does not seem to have a significant influence, however, growth rate decreased as the percentage rubber crumb increased, while treating the rubber with a weak acid or water prior to adding it to soil had the most positive effect on plant growth. It can therefore be concluded that rubber crumb amendment rates between 5% and 15% resulted in the most desirable soil physical properties and plant growth amongst the amendments. However the best plant growth was still seen in the control soil, to which no rubber crumb had been added.
- Full Text:
- Date Issued: 2019
- Authors: Gummow, William Thomas
- Date: 2019
- Subjects: Soil amendments , Plants -- Nutrition Plant physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39687 , vital:35348
- Description: South Africa is a semi-arid country that is experiencing population growth and the associated pressure of producing sufficient crops to sustain the population. Furthermore, poor land management has also led to increased degradation of valuable arable land. To improve poor soil quality and possibly avoid or reverse degradation and ultimately desertification, it was suggested that soil amendments are a potential solution to some of these problems. Although soil amendment is a relatively well-known practice to improve soil quality, the use of rubber crumb as a soil amendment is not well studied. Rubber crumb is produced from end-of-life tyres that have been ground up to fine particles and as such can be used as a secondary resource to replace the use of virgin materials. Rubber crumb has been used in an array of industries, however, the present study investigated the possibility that rubber crumb might be used as a soil amendment to alleviate various forms of soil degradation, specifically soil compaction and crusting, and potentially improve crop establishment and growth.To determine this, a soil that is prone to crusting and compaction was amended with rubber crumb at rates of 5%, 15% and 25%. Various soil physical characteristics, such as bulk density, particle density, porosity, field capacity and penetration resistance were investigated and it was determined that as the percentage rubber crumb increases in the soil, so do the beneficial characteristics of the soil. Furthermore, the rubber crumb was also treated in various ways in order to determine how the treatments might affect the chemical properties of the soil, as well as the amount of zinc that is leached from the rubber crumb. It was found that washing the rubber with a weak acid or even water prior to adding it to the soil resulted in more desirable chemical condition compared to untreated rubber crumb. Lastly, maize (Zea mays L.) was used to determine whether amending soil with pre-treated rubber crumb in different percentages had an influence on the germination success and growth rate of maize. In terms of germination success, amending soil with rubber crumb does not seem to have a significant influence, however, growth rate decreased as the percentage rubber crumb increased, while treating the rubber with a weak acid or water prior to adding it to soil had the most positive effect on plant growth. It can therefore be concluded that rubber crumb amendment rates between 5% and 15% resulted in the most desirable soil physical properties and plant growth amongst the amendments. However the best plant growth was still seen in the control soil, to which no rubber crumb had been added.
- Full Text:
- Date Issued: 2019
A hydrogeological investigation of Grahamstown, assessing both the dynamics and quality of the local groundwater system
- Authors: Smetherham, Kyle Norman
- Date: 2019
- Subjects: Hydrogeology -- South Africa -- Makhanda , Water quality -- South Africa -- Makhanda , Groundwater -- Quality -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/94444 , vital:31045
- Description: In many parts of South Africa, complete allocation of surface water reservoirs together with current drought conditions has led to serious water shortages and subsequent awareness regarding the importance to save water. Grahamstown is no different, with water problems relating to low supply and high demand being compounded by insufficient treatment capacity and aging infrastructure. Groundwater is an alternative water resource that could potentially act as a supplementary and/or emergency supply to the town, reducing the reliability on surface reservoirs. Groundwater however, is a hidden resource and requires an understanding of various aquifer properties and continuous monitoring and modelling so not to permanently disrupt the natural system but rather achieve sustainable management. Grahamstown is situated towards the northern extent of the Cape Fold Belt (CFB) system, within a synclinal fold structure. The local geology forms two local aquifer systems beneath Grahamstown that directly influence both the dynamics and quality of the groundwater. These underground reservoirs are the Witpoort and Dwyka aquifers and can be described as a semi-confined, fractured, quartzitic sandstone aquifer and an unconfined, fractured, tillite aquifer, respectively. Separating these aquifer systems is a shale aquitard, although due to the fractured nature of the rocks in the region there is most likely some groundwater interaction between them. Evaluation of geological formations together with the monitoring of 31 local boreholes presented a valuable conceptualisation of the local system and allowed for the application of methods to estimate recharge. Recharge estimation is one of the most crucial factors when managing aquifer systems as it can be used to determine what proportion of rainfall contributes to the subsurface reservoir and therefore, the sustainable amount that can be extracted. Various methods have been developed to estimate recharge, however due to the uncertainty surrounding groundwater systems, especially fractured aquifers, it was important to apply multiple methods to validate results. The water-table fluctuation (WTF) and cumulative rainfall departure (CRD) are two methods that were used in the present study to determine recharge. These methods rely on water-table changes in boreholes and specifically how they respond to rainfall events. Along with the WTF and CRD methods, a modelling approach was also used to estimate recharge which focused on the dynamics of a natural groundwater outlet, termed the Fairview Spring. This natural spring system is located just outside the main town of Grahamstown, within the Witpoort aquifer system, and is an important water resource to many residents due to poor supply and quality of municipal water. Monitoring the discharge of this spring allowed for the development of a model which attempts to recreate the discharge conditions observed. Along with groundwater recharge, other processes added to the model include evapotranspiration, storage, interflow spring outflow and groundwater outflow. Several different model simulation scenarios provided valuable insight into the greater groundwater dynamics. In terms of groundwater quality, nine borehole samples and one spring sample were analysed for major ions (Ca, Na, K, Cl, Mg, SO4, HCO3), metals (Cu, Fe, Mn) as well as pH and electrical conductivity. Overall electrical conductivity levels and major ion concentrations were lower in the Witpoort aquifer indicating a better groundwater quality compared to that of the Dwyka aquifer. Of the three metals included in the analysis, Mn proved to be the most significant and the highest concentrations were produced for samples that intersected the shale aquitard unit, suggesting that Mn-containing groundwater is drawn from this geological layer. Development of a supplementary and/or emergency groundwater supply requires careful consideration of the geology, quantity, quality, and recharge in the study site. All these aspects were assessed as well as deliberation into the potential infrastructural costs involved. Through conceptualisation of the system; evidence gathered during basic monitoring; and a simple spring model, the current study aimed to explore certain management strategies and recommend potential options going forward. The hidden nature of the resource together with the heterogeneity of fracture networks creates an inevitable uncertainty surrounding the system. Proper development and management of the aquifer can only be achieved if the system is continually monitored, modelled and utilised sustainably.
- Full Text:
- Date Issued: 2019
- Authors: Smetherham, Kyle Norman
- Date: 2019
- Subjects: Hydrogeology -- South Africa -- Makhanda , Water quality -- South Africa -- Makhanda , Groundwater -- Quality -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/94444 , vital:31045
- Description: In many parts of South Africa, complete allocation of surface water reservoirs together with current drought conditions has led to serious water shortages and subsequent awareness regarding the importance to save water. Grahamstown is no different, with water problems relating to low supply and high demand being compounded by insufficient treatment capacity and aging infrastructure. Groundwater is an alternative water resource that could potentially act as a supplementary and/or emergency supply to the town, reducing the reliability on surface reservoirs. Groundwater however, is a hidden resource and requires an understanding of various aquifer properties and continuous monitoring and modelling so not to permanently disrupt the natural system but rather achieve sustainable management. Grahamstown is situated towards the northern extent of the Cape Fold Belt (CFB) system, within a synclinal fold structure. The local geology forms two local aquifer systems beneath Grahamstown that directly influence both the dynamics and quality of the groundwater. These underground reservoirs are the Witpoort and Dwyka aquifers and can be described as a semi-confined, fractured, quartzitic sandstone aquifer and an unconfined, fractured, tillite aquifer, respectively. Separating these aquifer systems is a shale aquitard, although due to the fractured nature of the rocks in the region there is most likely some groundwater interaction between them. Evaluation of geological formations together with the monitoring of 31 local boreholes presented a valuable conceptualisation of the local system and allowed for the application of methods to estimate recharge. Recharge estimation is one of the most crucial factors when managing aquifer systems as it can be used to determine what proportion of rainfall contributes to the subsurface reservoir and therefore, the sustainable amount that can be extracted. Various methods have been developed to estimate recharge, however due to the uncertainty surrounding groundwater systems, especially fractured aquifers, it was important to apply multiple methods to validate results. The water-table fluctuation (WTF) and cumulative rainfall departure (CRD) are two methods that were used in the present study to determine recharge. These methods rely on water-table changes in boreholes and specifically how they respond to rainfall events. Along with the WTF and CRD methods, a modelling approach was also used to estimate recharge which focused on the dynamics of a natural groundwater outlet, termed the Fairview Spring. This natural spring system is located just outside the main town of Grahamstown, within the Witpoort aquifer system, and is an important water resource to many residents due to poor supply and quality of municipal water. Monitoring the discharge of this spring allowed for the development of a model which attempts to recreate the discharge conditions observed. Along with groundwater recharge, other processes added to the model include evapotranspiration, storage, interflow spring outflow and groundwater outflow. Several different model simulation scenarios provided valuable insight into the greater groundwater dynamics. In terms of groundwater quality, nine borehole samples and one spring sample were analysed for major ions (Ca, Na, K, Cl, Mg, SO4, HCO3), metals (Cu, Fe, Mn) as well as pH and electrical conductivity. Overall electrical conductivity levels and major ion concentrations were lower in the Witpoort aquifer indicating a better groundwater quality compared to that of the Dwyka aquifer. Of the three metals included in the analysis, Mn proved to be the most significant and the highest concentrations were produced for samples that intersected the shale aquitard unit, suggesting that Mn-containing groundwater is drawn from this geological layer. Development of a supplementary and/or emergency groundwater supply requires careful consideration of the geology, quantity, quality, and recharge in the study site. All these aspects were assessed as well as deliberation into the potential infrastructural costs involved. Through conceptualisation of the system; evidence gathered during basic monitoring; and a simple spring model, the current study aimed to explore certain management strategies and recommend potential options going forward. The hidden nature of the resource together with the heterogeneity of fracture networks creates an inevitable uncertainty surrounding the system. Proper development and management of the aquifer can only be achieved if the system is continually monitored, modelled and utilised sustainably.
- Full Text:
- Date Issued: 2019
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Nutrition -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44616 , vital:38152
- Description: Background: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. Aim: The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. Research design and methodology: A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results: Of the 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Conclusion and recommendations: Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Nutrition -- Education
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44616 , vital:38152
- Description: Background: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. Aim: The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. Research design and methodology: A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results: Of the 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Conclusion and recommendations: Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A nutrition education tool for practical application of the food based dietary guidelines for primary school teachers in Nelson Mandela Bay
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Malnutrition -- South Africa -- Port Elizabeth , Nutrition—Evaluation Nutrition -- Evaluation Nutrition -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45019 , vital:38226
- Description: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results of the research 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
- Authors: Joubert, Tayla Kate
- Date: 2019
- Subjects: Malnutrition -- South Africa -- Port Elizabeth , Nutrition—Evaluation Nutrition -- Evaluation Nutrition -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45019 , vital:38226
- Description: The South Africa Food-Based Dietary Guidelines (SAFBDG) was developed to promote better food choices for a healthy lifestyle and are included in the school syllabus. Schools remain viable platforms for nutrition education with teachers playing significant roles, but research has shown that teachers do not necessarily know about the SAFBDG and how to incorporate these into the teaching programme. The aim of this study was to develop a tool in the form of a nutrition education guide for primary school teachers, aimed at the practical application of the SAFBDG, in order to enhance the nutrition knowledge, attitudes and dietary practices of the teachers. A quasi-experimental, one group, quantitative design was employed. Forty-six teachers were conveniently chosen from schools in previously disadvantaged areas of Nelson Mandela Bay. The study design consisted of four phases. Phase one consisted of a pre-test where the teachers’ nutrition knowledge, nutrition attitudes, dietary practices, staff wellness and physical activity were determined by means of a standardised questionnaire. A nutritional assessment was also conducted in phase one. In phase two, the nutrition guide, which was Curriculum Assessment Policy Statement compliant for grades four to seven, was developed. In phase three, the guide was used in a workshop to train the teachers that attended phase one of the study, on how to use the nutrition education guide. In phase four, a post-test was conducted after the training to evaluate the effectiveness of the training and to determine whether there has been an increase in the teachers’ nutrition knowledge. Data from the questionnaires were analysed on Microsoft Excel 2016 MSO (16.0.4639.1000). Ethical approval for this study was obtained from the Faculty Postgraduate Studies Committee (FPGSC) of the Faculty of Health Sciences, Nelson Mandela University (Ethics clearance reference number: H18-HEA-DIET-005) and all ethical principles were upheld according to the Belmont report and the Declaration of Helsinki. Results of the research 46 teachers who participated 36 (78 %) were obese. The mean waist circumference and waist-to-hip ratio was 109.99 and 0.887 respectively (± 17.32 and ± 0.089). The teachers obtained a relatively high mean overall score in the pre-test of 69 % (± 10.78). Only 42 % of the teachers had heard of the SAFBDG before the study. There was an overall statistical significant increase in knowledge of 6 % (p = 0.03) from the pre-test to the post-test. The dietary practice was obtained through a food frequency questionnaire (FFQ), which showed under-reporting. The most neglected food groups were legumes, dairy and vegetables/ fruit. Hypertension was the highest self-reported condition, with just under a quarter of the teachers having hypertension (high blood pressure). There was no statistical significance between the teachers’ BMI and their nutrition knowledge as well as no statistical significance between their BMI and their physical activity level. Even though the teachers obtained a relatively high mean overall score in their pre-test, there were still gaps in their nutrition knowledge. These gaps in the teachers’ knowledge results in insufficient nutrition knowledge being provided to the learners, leading to poor dietary practices and misconceptions regarding different foods among the learners as well as the teachers. By providing training for the teachers, it will not only improve their nutrition knowledge but potentially also help to improve their lifestyle. With enhanced nutrition knowledge, the teachers can communicate sufficient information to their learners. The DoBE need to advocate for a healthier school environment in which the SAFBDG are implemented more extensively in the curriculum as well as part of school food policies.
- Full Text:
- Date Issued: 2019
A pilot wide-field VLBI survey of the GOODS-North field
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
A Statistical assessment of available solar resource across multiple sites in South Africa
- Authors: Eastwood, Kirstie
- Date: 2019
- Subjects: Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39907 , vital:35505
- Description: Around the globe, fossil fuels remain the primary source of energy at around 78% of the world’s total energy consumption. However, the associated carbon emissions, environmental impact, the depletion of fossil fuels and price and cost volatility are factors influencing the growing popularity of research into renewable energy. Solar power is acknowledged as the fastest-growing renewable energy, but the uncertainty surrounding the long-term projections of solar irradiance available for energy conversion is a hindrance when discussing the financial risk with potential investors. This study investigates the quality of freely available solar resource data in South Africa as well as proposes techniques for potential solar farm site comparisons. Tolerance intervals derived within a Bayesian framework provide information on the future available solar resource across multiple sites. These techniques capture the inherent variability in the available solar resource which equips investors with statistical methods that lead to the better understanding of the solar resource and thus aids in better decision-making.
- Full Text:
- Date Issued: 2019
- Authors: Eastwood, Kirstie
- Date: 2019
- Subjects: Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39907 , vital:35505
- Description: Around the globe, fossil fuels remain the primary source of energy at around 78% of the world’s total energy consumption. However, the associated carbon emissions, environmental impact, the depletion of fossil fuels and price and cost volatility are factors influencing the growing popularity of research into renewable energy. Solar power is acknowledged as the fastest-growing renewable energy, but the uncertainty surrounding the long-term projections of solar irradiance available for energy conversion is a hindrance when discussing the financial risk with potential investors. This study investigates the quality of freely available solar resource data in South Africa as well as proposes techniques for potential solar farm site comparisons. Tolerance intervals derived within a Bayesian framework provide information on the future available solar resource across multiple sites. These techniques capture the inherent variability in the available solar resource which equips investors with statistical methods that lead to the better understanding of the solar resource and thus aids in better decision-making.
- Full Text:
- Date Issued: 2019
A study of malicious software on the macOS operating system
- Authors: Regensberg, Mark Alan
- Date: 2019
- Subjects: Malware (Computer software) , Computer security , Computer viruses , Mac OS
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92302 , vital:30701
- Description: Much of the published malware research begins with a common refrain: the cost, quantum and complexity of threats are increasing, and research and practice should prioritise efforts to automate and reduce times to detect and prevent malware, while improving the consistency of categories and taxonomies applied to modern malware. Existing work related to malware targeting Apple's macOS platform has not been spared this approach, although limited research has been conducted on the true nature of threats faced by users of the operating system. While macOS focused research available consistently notes an increase in macOS users, devices and ultimately in threats, an opportunity exists to understand the real nature of threats faced by macOS users and suggest potential avenues for future work. This research provides a view of the current state of macOS malware by analysing and exploring a dataset of malware detections on macOS endpoints captured over a period of eleven months by an anti-malware software vendor. The dataset is augmented with malware information provided by the widely used Virus. Total service, as well as the application of prior automated malware categorisation work, AVClass to categorise and SSDeep to cluster and report on observed data. With Windows and Android platforms frequently in the spotlight as targets for highly disruptive malware like botnets, ransomware and cryptominers, research and intuition seem to suggest the threat of malware on this increasingly popular platform should be growing and evolving accordingly. Findings suggests that the direction and nature of growth and evolution may not be entirely as clear as industry reports suggest. Adware and Potentially Unwanted Applications (PUAs) make up the vast majority of the detected threats, with remote access trojans (RATs), ransomware and cryptocurrency miners comprising a relatively small proportion of the detected malware. This provides a number of avenues for potential future work to compare and contrast with research on other platforms, as well as identification of key factors that may influence its growth in the future.
- Full Text:
- Date Issued: 2019
- Authors: Regensberg, Mark Alan
- Date: 2019
- Subjects: Malware (Computer software) , Computer security , Computer viruses , Mac OS
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92302 , vital:30701
- Description: Much of the published malware research begins with a common refrain: the cost, quantum and complexity of threats are increasing, and research and practice should prioritise efforts to automate and reduce times to detect and prevent malware, while improving the consistency of categories and taxonomies applied to modern malware. Existing work related to malware targeting Apple's macOS platform has not been spared this approach, although limited research has been conducted on the true nature of threats faced by users of the operating system. While macOS focused research available consistently notes an increase in macOS users, devices and ultimately in threats, an opportunity exists to understand the real nature of threats faced by macOS users and suggest potential avenues for future work. This research provides a view of the current state of macOS malware by analysing and exploring a dataset of malware detections on macOS endpoints captured over a period of eleven months by an anti-malware software vendor. The dataset is augmented with malware information provided by the widely used Virus. Total service, as well as the application of prior automated malware categorisation work, AVClass to categorise and SSDeep to cluster and report on observed data. With Windows and Android platforms frequently in the spotlight as targets for highly disruptive malware like botnets, ransomware and cryptominers, research and intuition seem to suggest the threat of malware on this increasingly popular platform should be growing and evolving accordingly. Findings suggests that the direction and nature of growth and evolution may not be entirely as clear as industry reports suggest. Adware and Potentially Unwanted Applications (PUAs) make up the vast majority of the detected threats, with remote access trojans (RATs), ransomware and cryptocurrency miners comprising a relatively small proportion of the detected malware. This provides a number of avenues for potential future work to compare and contrast with research on other platforms, as well as identification of key factors that may influence its growth in the future.
- Full Text:
- Date Issued: 2019
A suitability study for the implementation of a corporate geographic information system at the King Sabata Dalindyebo Municipality
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
- Authors: Triegaardt, Inge
- Date: 2019
- Subjects: Geographic information systems , Information storage and retrieval systems -- Geography Information technology Sustainable development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:37044
- Description: A tender in the Government Gazette in 2013 for the implementation of a Corporate Geographic Information System (CGIS) at the King Sabata Dalindeybo (KSD) Local Municipality, created an opportunity for a study to be conducted for the implementation of a Corporate Geographic Information System (CGIS). A CGIS is a suitable management system for implementation at a municipality, given that the municipality is ready. Internationally the implementation of CGIS at municipalities has been done successfully. In South Africa, however, the implementation of said software has been slow and at times unsuccessful. The purpose of this research study was to evaluate the current GIS knowledge and infrastructure of the KSD Local Municipality for the municipality to be a suitable candidate for the implementation of a CGIS. The evaluation was done by the collection of data through three questionnaires, two interviews and observations. The findings of this research study are discussed according to the qualitative data collected from the KSD Local Municipality and recommendations based on the results of the data collection have been made for the municipality to be implementation ready. The qualitative instruments such as pre-training, post-training/pre-implementation and postimplementation questionnaires, observations and interviews with the IT Technician and the CGIS Specialist were processed by the researcher to obtain insight to the perceptions of the employees and the current state of GIS in the KSD Local Municipality. The results from this research study were in-line with the benefits and barriers of implementation of a CGIS in municipalities in international literature.
- Full Text:
- Date Issued: 2019
A technical survey of the South African harvesting machine population
- Authors: Mathelele, Ouma Florah
- Date: 2019
- Subjects: Harvesting -- South Africa , Energy harvesting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40999 , vital:36281
- Description: South Africa adopted the practice of conducting technical surveys from Austria three decades ago. The Austrian technical survey was used to model the South African technical survey. The survey was conducted with the aim of providing the forestry industry with a detailed analysis of the state of timber harvesting operations. The first technical survey in South Africa was conducted in 1987, and the second one in 1998. The most recent study was carried out in 2007. Since 2007, there has been no other technical survey of a similar nature conducted on harvesting and transport operations. There is no recent information quantifying the volumes harvested, identifying harvesting systems and methods used, and determining volumes harvested using these systems and methods. Furthermore, no updated information exists on the type and quantities of timber trucks transporting the volume. A fourth technical survey that quantifies and analyses these aspects in harvesting operations, therefore, was due. The fourth technical survey aimed at quantifying the number of harvesting machines and timber trucks. The survey further investigated the drivers behind the mechanisation and system preference. The four technical surveys were compared to identify trends in harvesting machines and methods. The data were collected from grower companies, harvesting and transport contractors and small-scale timber growers. Questionnaires were sent to all potential respondents from the three target groups, and interviews were later conducted with selected respondents. The harvesting machines were quantified per function i.e. felling, extraction, processing and loading. The results showed that some machines were more common compared to other machines performing the same function. Mechanised felling machines sampled had more units in the fourth survey than the previous surveys had. Of the 10.6 million m3 volume surveyed in 2017, chainsaws had 1 048 units, and their number had decreased from the 5 000 sampled in the first technical survey in 1987 that sampled about 12.8 million m3. Harvesters and feller bunchers also increased from zero in the first technical survey to 94 and 13, respectively in the fourth survey. The drivers towards the increased use of mechanised equipment were identified as safety and health, ergonomics, productivity, labour issues, operational costs, terrain, and company policies. Despite the introduction of mechanisation, however, the use of manual labour was evident in hardwood processing and loading operations. Manual debarking was more common than mechanised debarking in the fourth technical survey. When comparing all four technical surveys, the cut to length (CTL) harvesting method was dominant in hardwood; harvesting 79% of the volume sampled in the 2017 survey. The full tree method was barely applied in the first three technical surveys and in the 2007 survey, it was absent. It was only in the fourth technical survey that the method was applied, felling 27% and 9% of the sampled volumes in softwood and hardwood, respectively. The technical survey provides information to the different stakeholders in the forest industry. Such include harvesting managers and contractors, grower companies, machine distributors and researchers. The information will bring awareness to harvesting managers and contractors about the different machine options available to assist in decision making when selecting systems. Machine distributors will know the number of machines, where machines are operating and their target market. A gap in knowledge will be bridged between the different provinces regarding the different types of harvesting machines out there.
- Full Text:
- Date Issued: 2019
- Authors: Mathelele, Ouma Florah
- Date: 2019
- Subjects: Harvesting -- South Africa , Energy harvesting -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/40999 , vital:36281
- Description: South Africa adopted the practice of conducting technical surveys from Austria three decades ago. The Austrian technical survey was used to model the South African technical survey. The survey was conducted with the aim of providing the forestry industry with a detailed analysis of the state of timber harvesting operations. The first technical survey in South Africa was conducted in 1987, and the second one in 1998. The most recent study was carried out in 2007. Since 2007, there has been no other technical survey of a similar nature conducted on harvesting and transport operations. There is no recent information quantifying the volumes harvested, identifying harvesting systems and methods used, and determining volumes harvested using these systems and methods. Furthermore, no updated information exists on the type and quantities of timber trucks transporting the volume. A fourth technical survey that quantifies and analyses these aspects in harvesting operations, therefore, was due. The fourth technical survey aimed at quantifying the number of harvesting machines and timber trucks. The survey further investigated the drivers behind the mechanisation and system preference. The four technical surveys were compared to identify trends in harvesting machines and methods. The data were collected from grower companies, harvesting and transport contractors and small-scale timber growers. Questionnaires were sent to all potential respondents from the three target groups, and interviews were later conducted with selected respondents. The harvesting machines were quantified per function i.e. felling, extraction, processing and loading. The results showed that some machines were more common compared to other machines performing the same function. Mechanised felling machines sampled had more units in the fourth survey than the previous surveys had. Of the 10.6 million m3 volume surveyed in 2017, chainsaws had 1 048 units, and their number had decreased from the 5 000 sampled in the first technical survey in 1987 that sampled about 12.8 million m3. Harvesters and feller bunchers also increased from zero in the first technical survey to 94 and 13, respectively in the fourth survey. The drivers towards the increased use of mechanised equipment were identified as safety and health, ergonomics, productivity, labour issues, operational costs, terrain, and company policies. Despite the introduction of mechanisation, however, the use of manual labour was evident in hardwood processing and loading operations. Manual debarking was more common than mechanised debarking in the fourth technical survey. When comparing all four technical surveys, the cut to length (CTL) harvesting method was dominant in hardwood; harvesting 79% of the volume sampled in the 2017 survey. The full tree method was barely applied in the first three technical surveys and in the 2007 survey, it was absent. It was only in the fourth technical survey that the method was applied, felling 27% and 9% of the sampled volumes in softwood and hardwood, respectively. The technical survey provides information to the different stakeholders in the forest industry. Such include harvesting managers and contractors, grower companies, machine distributors and researchers. The information will bring awareness to harvesting managers and contractors about the different machine options available to assist in decision making when selecting systems. Machine distributors will know the number of machines, where machines are operating and their target market. A gap in knowledge will be bridged between the different provinces regarding the different types of harvesting machines out there.
- Full Text:
- Date Issued: 2019
Aeolian processes and landforms at Mesrug on sub-Antarctic Marion Island
- Authors: Nguna, Abuyiselwe Athandile
- Date: 2019
- Subjects: Eolian processes Sediments (Geology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17095 , vital:40848
- Description: Recent observations have recognised the increasing role of aeolian processes as a geomorphic agent on sub-Antarctic Marion Island. This study presents the first long-term data on aeolian processes and dynamics at Mesrug (46° 56’ 41”S; 37° 49’ 59”E) on subAntarctic Marion Island. An intensive and high-resolution (five-minute interval) environmental monitoring campaign was initiated using Pace Scientific XR5 data loggers while aeolian transported sediments were collected using Big Spring Number Eight (BSNE) sediment traps at four different heights above the ground. The aeolian features at Mesrug is identified as mega-ripples and is essentially an erosional feature, while annual sediment flux at 0.05 m height were calculated as 2.29 kg cm-2 y -1 . Spatial data based on a two-year survey showed that the entire surface of the study area have lowered by deflation while the ripples shifted slightly eastward (down-wind). Furthermore, the site lost 3.4 m3 of sediment between these two surveys with an average of 0.75 cm per 1 m2 across the site which has an area of 454 m2 . The study suggest that the relatively large particle size of surface sediments on Marion Island is a major contributor to the low annual aeolian sediment flux. From the AWS data it is clear that high wind speeds are frequent at Mesrug and the high wind speeds facilitating sediment movement. Sediment supply is the limiting factor of aeolian sediment transport, but even though the perennial wetness experienced on the island is not a major limiting factor to sediment flux, it may influence rate of movement. The predominant wind direction at the study site is from the south-west but maximum wind velocities are from the north-west. The data from the wind-aspirated BSNE sediment traps, indicate that sediment movement occurs closest to the surface and weight of sediment moved as well as size of particles decreases vertically in the air column. It seems that the upper limit of aeolian sediment transport at Mesrug is 0.8 m above the ground and saltation of particles is the dominant aeolian transport mechanism. Sediment movement occur in near gale to gale force winds and horizontal precipitation. This is mainly associated with strong north-westerly winds which are linked to a frontal system from a mid-latitudinal cyclone that has a strong meridional component or is a cut of low pressure. The data suggest that the climate change implication of a reduction in the westerly component of wind could reduce wind speeds and this could influence the magnitude and frequency of aeolian sediment transport on Marion Island in the future
- Full Text:
- Date Issued: 2019
- Authors: Nguna, Abuyiselwe Athandile
- Date: 2019
- Subjects: Eolian processes Sediments (Geology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17095 , vital:40848
- Description: Recent observations have recognised the increasing role of aeolian processes as a geomorphic agent on sub-Antarctic Marion Island. This study presents the first long-term data on aeolian processes and dynamics at Mesrug (46° 56’ 41”S; 37° 49’ 59”E) on subAntarctic Marion Island. An intensive and high-resolution (five-minute interval) environmental monitoring campaign was initiated using Pace Scientific XR5 data loggers while aeolian transported sediments were collected using Big Spring Number Eight (BSNE) sediment traps at four different heights above the ground. The aeolian features at Mesrug is identified as mega-ripples and is essentially an erosional feature, while annual sediment flux at 0.05 m height were calculated as 2.29 kg cm-2 y -1 . Spatial data based on a two-year survey showed that the entire surface of the study area have lowered by deflation while the ripples shifted slightly eastward (down-wind). Furthermore, the site lost 3.4 m3 of sediment between these two surveys with an average of 0.75 cm per 1 m2 across the site which has an area of 454 m2 . The study suggest that the relatively large particle size of surface sediments on Marion Island is a major contributor to the low annual aeolian sediment flux. From the AWS data it is clear that high wind speeds are frequent at Mesrug and the high wind speeds facilitating sediment movement. Sediment supply is the limiting factor of aeolian sediment transport, but even though the perennial wetness experienced on the island is not a major limiting factor to sediment flux, it may influence rate of movement. The predominant wind direction at the study site is from the south-west but maximum wind velocities are from the north-west. The data from the wind-aspirated BSNE sediment traps, indicate that sediment movement occurs closest to the surface and weight of sediment moved as well as size of particles decreases vertically in the air column. It seems that the upper limit of aeolian sediment transport at Mesrug is 0.8 m above the ground and saltation of particles is the dominant aeolian transport mechanism. Sediment movement occur in near gale to gale force winds and horizontal precipitation. This is mainly associated with strong north-westerly winds which are linked to a frontal system from a mid-latitudinal cyclone that has a strong meridional component or is a cut of low pressure. The data suggest that the climate change implication of a reduction in the westerly component of wind could reduce wind speeds and this could influence the magnitude and frequency of aeolian sediment transport on Marion Island in the future
- Full Text:
- Date Issued: 2019
Affordability of housing in the gap market: a case of Walmer link in Port Elizabeth, South Africa
- Makeleni, Nokukhanya Precious
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
- Authors: Makeleni, Nokukhanya Precious
- Date: 2019
- Subjects: Home ownership -- South Africa -- Port Elizabeth , Housing -- South Africa -- Port Elizabeth Public housing -- South Africa -- Port Elizabeth Rental housing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/42562 , vital:36668
- Description: The new dispensation, after 1994, in South Africa has been criticised a lot for not being able to satisfactorily achieve its election promise of redistribution and poverty alleviation. While success has been noted in the provision of low cost housing and subsequently home ownership for lower income earners, housing demand continues to be a challenge in the delivery capacity of housing for most South Africans. The people most excluded from homeownership include the public sector employees and laborers who face common, but different constraints. These people are classified as middle-income earners, they are either earn too much to qualify for a housing subsidy (RDP house), or too less to afford a house in the prime market. These people are referred to as the “gap market” because they fall with the gap of high and lowincome earners. Adopting a qualitative research method, survey questionnaire were sent to selective respondents involved in the development of affordable housing in the gap market in Walmer Link, Port Elizabeth, Nelson Mandela Bay Metropolitan area. This research sought to assess the affordability of housing in gap market, by understanding the challenges faced by the housing market in addressing the needs of the gap market in Walmer Link. Obstacles that hinders closure in the gap housing delivery, such as affordability, over indebtedness, poor credit ratings and inadequate supply for affordable housing in the gap market were identified during the research. While these obstacles show little indication of abating, this research’s findings and recommendations suggest new pathways for formulating new housing policies that address the housing backlog in the gap market. This also suggests that government policies are critical in developing a healthy and inclusive housing market.
- Full Text:
- Date Issued: 2019
Amaranth (Amaranthus cruentus) growth and nutritional contents as affected by nitrogen and potassium fertiliser and plant density
- Authors: Mamvura, Luckmore
- Date: 2019
- Subjects: Weeds -- Control -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17249 , vital:40869
- Description: The research was conducted to determine the response of amaranth growth and development to different rates of nitrogen and potassium fertilizer, the effect of plant density on herbage yield and weed management, effect of leaf age and stems on nutritional value of amaranths. The research was conducted at the University of Fort Hare Research Farm and University of Fort Hare glasshouse. For the fertilizer trial, a 4 x 3 factorial experiment: nitrogen at four levels (50kg/ha; 100kg/ha; 150kg/ha; 200kg/ha) and potassium at three levels (50kg/ha; 75kg/ha; 100kg/ha) was applied. Phosphorus was applied at 50kg/ha. The experiment was laid as randomised complete block design (RCBD) with 4 blocks (replication). The results showed that application of nitrogen and potassium treatments significantly (P < 0.05) increased plant height, stem girth and number of leaves per plant which in turn increased the crop economic leaf vegetative yield. The results also showed that at high rates of nitrogen and potassium, high vegetative yields were achieved in most cases. There was no interaction (P < 0.05) between nitrogen and potassium. Second experiment, the twelve treatments used in fertilizer trial were imposed under four different amaranth plant densities (1 200 000, 1400 000, 1600 000 and 1800 000 pph) at field level to find out growth and development performance of amaranth. In addition, at the same time investigating the effectiveness of plant density on weeds management using split plot design. The different planting densities were allocated to the main plots laid-out in RCBD. The results showed that there was no significant difference (P < 0.05) on the number of weeds under four plant densities. The results showed that different plant densities did not prevent weeds germination but the amaranths tolerate the negative effects of weeds. The nutritional analysis results showed that amaranth synthesised close to above recommended nutritional level despite different treatments applied. The third experiment: stems, lower and upper leaves were harvested separately and their nutritional composition was analysed. The results showed that the nutritional composition of stems, lower leaves and upper leaves were significantly different (P < 0.05) in most cases. Lower leaves dominated nutritional content for: crude protein crude fibre, carbohydrates, and calcium. The stems recorded least nutritional content on crude protein, crude fat, carbohydrates, calcium, potassium and sodium
- Full Text:
- Date Issued: 2019
- Authors: Mamvura, Luckmore
- Date: 2019
- Subjects: Weeds -- Control -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17249 , vital:40869
- Description: The research was conducted to determine the response of amaranth growth and development to different rates of nitrogen and potassium fertilizer, the effect of plant density on herbage yield and weed management, effect of leaf age and stems on nutritional value of amaranths. The research was conducted at the University of Fort Hare Research Farm and University of Fort Hare glasshouse. For the fertilizer trial, a 4 x 3 factorial experiment: nitrogen at four levels (50kg/ha; 100kg/ha; 150kg/ha; 200kg/ha) and potassium at three levels (50kg/ha; 75kg/ha; 100kg/ha) was applied. Phosphorus was applied at 50kg/ha. The experiment was laid as randomised complete block design (RCBD) with 4 blocks (replication). The results showed that application of nitrogen and potassium treatments significantly (P < 0.05) increased plant height, stem girth and number of leaves per plant which in turn increased the crop economic leaf vegetative yield. The results also showed that at high rates of nitrogen and potassium, high vegetative yields were achieved in most cases. There was no interaction (P < 0.05) between nitrogen and potassium. Second experiment, the twelve treatments used in fertilizer trial were imposed under four different amaranth plant densities (1 200 000, 1400 000, 1600 000 and 1800 000 pph) at field level to find out growth and development performance of amaranth. In addition, at the same time investigating the effectiveness of plant density on weeds management using split plot design. The different planting densities were allocated to the main plots laid-out in RCBD. The results showed that there was no significant difference (P < 0.05) on the number of weeds under four plant densities. The results showed that different plant densities did not prevent weeds germination but the amaranths tolerate the negative effects of weeds. The nutritional analysis results showed that amaranth synthesised close to above recommended nutritional level despite different treatments applied. The third experiment: stems, lower and upper leaves were harvested separately and their nutritional composition was analysed. The results showed that the nutritional composition of stems, lower leaves and upper leaves were significantly different (P < 0.05) in most cases. Lower leaves dominated nutritional content for: crude protein crude fibre, carbohydrates, and calcium. The stems recorded least nutritional content on crude protein, crude fat, carbohydrates, calcium, potassium and sodium
- Full Text:
- Date Issued: 2019
An analysis of the use of DNS for malicious payload distribution
- Authors: Dube, Ishmael
- Date: 2019
- Subjects: Internet domain names , Computer networks -- Security measures , Computer security , Computer network protocols , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97531 , vital:31447
- Description: The Domain Name System (DNS) protocol is a fundamental part of Internet activities that can be abused by cybercriminals to conduct malicious activities. Previous research has shown that cybercriminals use different methods, including the DNS protocol, to distribute malicious content, remain hidden and avoid detection from various technologies that are put in place to detect anomalies. This allows botnets and certain malware families to establish covert communication channels that can be used to send or receive data and also distribute malicious payloads using the DNS queries and responses. Cybercriminals use the DNS to breach highly protected networks, distribute malicious content, and exfiltrate sensitive information without being detected by security controls put in place by embedding certain strings in DNS packets. This research undertaking broadens this research field and fills in the existing research gap by extending the analysis of DNS being used as a payload distribution channel to detection of domains that are used to distribute different malicious payloads. This research undertaking analysed the use of the DNS in detecting domains and channels that are used for distributing malicious payloads. Passive DNS data which replicate DNS queries on name servers to detect anomalies in DNS queries was evaluated and analysed in order to detect malicious payloads. The research characterises the malicious payload distribution channels by analysing passive DNS traffic and modelling the DNS query and response patterns. The research found that it is possible to detect malicious payload distribution channels through the analysis of DNS TXT resource records.
- Full Text:
- Date Issued: 2019
- Authors: Dube, Ishmael
- Date: 2019
- Subjects: Internet domain names , Computer networks -- Security measures , Computer security , Computer network protocols , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97531 , vital:31447
- Description: The Domain Name System (DNS) protocol is a fundamental part of Internet activities that can be abused by cybercriminals to conduct malicious activities. Previous research has shown that cybercriminals use different methods, including the DNS protocol, to distribute malicious content, remain hidden and avoid detection from various technologies that are put in place to detect anomalies. This allows botnets and certain malware families to establish covert communication channels that can be used to send or receive data and also distribute malicious payloads using the DNS queries and responses. Cybercriminals use the DNS to breach highly protected networks, distribute malicious content, and exfiltrate sensitive information without being detected by security controls put in place by embedding certain strings in DNS packets. This research undertaking broadens this research field and fills in the existing research gap by extending the analysis of DNS being used as a payload distribution channel to detection of domains that are used to distribute different malicious payloads. This research undertaking analysed the use of the DNS in detecting domains and channels that are used for distributing malicious payloads. Passive DNS data which replicate DNS queries on name servers to detect anomalies in DNS queries was evaluated and analysed in order to detect malicious payloads. The research characterises the malicious payload distribution channels by analysing passive DNS traffic and modelling the DNS query and response patterns. The research found that it is possible to detect malicious payload distribution channels through the analysis of DNS TXT resource records.
- Full Text:
- Date Issued: 2019
An assessment of amount, distribution and use of urban green spaces in small towns of the Eastern Cape
- Authors: Radebe, Denis Siphosihle
- Date: 2019
- Subjects: Urban ecology (Sociology) -- South Africa -- Eastern Cape , Small cities -- South Africa -- Eastern Cape , City planning -- South Africa -- Eastern Cape , Recreation areas -- South Africa -- Eastern Cape , Open spaces -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76447 , vital:30563
- Description: Most regions of the developing world are experiencing large-scale urbanisation, with urban population growth outstripping rural growth. This is most marked in small and medium-sized towns as opposed to megacities. Urbanisation is associated with numerous changes in social, economic and ecological states and dynamics. A key one, of interest in this study, is the sustainability and liveability of the growing towns and cities. The retention, provision and maintenance of multifunctional urban green infrastructure are a core strategy in this regard. This study therefore sought to assess the amount, distribution and use of urban green spaces within South Africa using small towns of the Eastern Cape. The primary research included sixteen aerial images of which eight were historical aerial photographs and another eight were the latest aerial images of the selected study towns. Historical and latest aerial images were digitised to classify the types and calculate the amount of urban green space. GIS mapping, interviews and focus group discussions were conducted with urban residents to understand how these green spaces are used. The analytical tools in this study derived from social science included household surveys of 180 randomly selected respondents in small towns. Fifteen types of green spaces were identified in the sample towns. The study further revealed that green spaces are not distributed equally in different suburbs of small towns, generally being less green spaces, especially formal parks and recreation areas, in poorer areas. The results indicated a decline of green spaces with urbanisation, and most marked in fast growing towns. The results suggested that urban residents frequently visited urban green spaces, with most respondents favouring the use of green spaces for social and cultural benefits. How use of different spaces was strongly gender related, with males favouring less developed green space types (such as commonages and woodlands) and females for formal areas such domestic and institutional gardens and churchyards. Respondents also identified various challenges associated with using and accessing urban green spaces, with pollution, crime and lack of maintenance in particular. The study shows the importance of GIS as a mapping tool that can be used to provide information for ecological planning in rapidly changing urban environment. The research process generated several lessons that need to be taken into consideration when designing urban landscapes, most importantly relating to the diversity, quantity, quality and maintenance of urban green spaces.
- Full Text:
- Date Issued: 2019
- Authors: Radebe, Denis Siphosihle
- Date: 2019
- Subjects: Urban ecology (Sociology) -- South Africa -- Eastern Cape , Small cities -- South Africa -- Eastern Cape , City planning -- South Africa -- Eastern Cape , Recreation areas -- South Africa -- Eastern Cape , Open spaces -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76447 , vital:30563
- Description: Most regions of the developing world are experiencing large-scale urbanisation, with urban population growth outstripping rural growth. This is most marked in small and medium-sized towns as opposed to megacities. Urbanisation is associated with numerous changes in social, economic and ecological states and dynamics. A key one, of interest in this study, is the sustainability and liveability of the growing towns and cities. The retention, provision and maintenance of multifunctional urban green infrastructure are a core strategy in this regard. This study therefore sought to assess the amount, distribution and use of urban green spaces within South Africa using small towns of the Eastern Cape. The primary research included sixteen aerial images of which eight were historical aerial photographs and another eight were the latest aerial images of the selected study towns. Historical and latest aerial images were digitised to classify the types and calculate the amount of urban green space. GIS mapping, interviews and focus group discussions were conducted with urban residents to understand how these green spaces are used. The analytical tools in this study derived from social science included household surveys of 180 randomly selected respondents in small towns. Fifteen types of green spaces were identified in the sample towns. The study further revealed that green spaces are not distributed equally in different suburbs of small towns, generally being less green spaces, especially formal parks and recreation areas, in poorer areas. The results indicated a decline of green spaces with urbanisation, and most marked in fast growing towns. The results suggested that urban residents frequently visited urban green spaces, with most respondents favouring the use of green spaces for social and cultural benefits. How use of different spaces was strongly gender related, with males favouring less developed green space types (such as commonages and woodlands) and females for formal areas such domestic and institutional gardens and churchyards. Respondents also identified various challenges associated with using and accessing urban green spaces, with pollution, crime and lack of maintenance in particular. The study shows the importance of GIS as a mapping tool that can be used to provide information for ecological planning in rapidly changing urban environment. The research process generated several lessons that need to be taken into consideration when designing urban landscapes, most importantly relating to the diversity, quantity, quality and maintenance of urban green spaces.
- Full Text:
- Date Issued: 2019
An Assessment of the Environmental Impacts of Urban Sprawl in Buffalo City Metropolitan Municipality, Eastern Cape Province
- Authors: Matiza, Collins
- Date: 2019
- Subjects: Cities and towns -- Growth -- Environmental aspects City planning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17260 , vital:40870
- Description: Large industrial and residential developments near towns and along highways associated with public policies have transformed the pattern of development over the recent years, creating a new urbanisation phenomenon; urban sprawl. Indiscriminate population densities, discontinuous and fragmented settlements, largely define urban sprawl. The progression of urban sprawl can be described by transformation in pattern over time, like proportional increase in built-up surface to population leading to rapid urban spatial expansion. Stemming an understanding from the processes, causes and patterns of urban sprawl, the consequences of sprawl on land and vegetation can be analysed. Environmental impacts to both the rural and urban population emanate from such instances, creating an excessive liability to the government. With attention to this and recognising the lack of discussion on the matter, the research deliberates some of the impacts observed in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa. The study makes use of Geographic Information Systems and Remote Sensing with the assistance of landscape metrics. The influence of urban sprawl in this municipality has revealed impacts on vegetation, green areas and land in general. The results disclose that urban sprawl is a multidimensional phenomenon that is better explained using various methods (indices). Buffalo City Metropolitan municipality is located in Eastern Cape amidst the thicket ecosystem, the municipality has grown and expanded over the recent past. The study spread over an 18-year period from 1994- 2012. Based on field surveys and SPOT imagery, built-up areas of BCMM was extracted for different periods. Data used for the study are census data for BCMM, 1994, 2000, 2006 and 2012 SPOT images, images of BCMM acquired from Google earth 2018. The rate of transformation of the area was calculated and it was higher compared to that of population growth. Based on this data urban growth are analysed with the assistance of landscape metrics that include Shannon entropy. The outcomes confirm that this metropolitan municipality has experienced sprawl and sprawl has done so at cumulative rate.
- Full Text:
- Date Issued: 2019
- Authors: Matiza, Collins
- Date: 2019
- Subjects: Cities and towns -- Growth -- Environmental aspects City planning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17260 , vital:40870
- Description: Large industrial and residential developments near towns and along highways associated with public policies have transformed the pattern of development over the recent years, creating a new urbanisation phenomenon; urban sprawl. Indiscriminate population densities, discontinuous and fragmented settlements, largely define urban sprawl. The progression of urban sprawl can be described by transformation in pattern over time, like proportional increase in built-up surface to population leading to rapid urban spatial expansion. Stemming an understanding from the processes, causes and patterns of urban sprawl, the consequences of sprawl on land and vegetation can be analysed. Environmental impacts to both the rural and urban population emanate from such instances, creating an excessive liability to the government. With attention to this and recognising the lack of discussion on the matter, the research deliberates some of the impacts observed in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa. The study makes use of Geographic Information Systems and Remote Sensing with the assistance of landscape metrics. The influence of urban sprawl in this municipality has revealed impacts on vegetation, green areas and land in general. The results disclose that urban sprawl is a multidimensional phenomenon that is better explained using various methods (indices). Buffalo City Metropolitan municipality is located in Eastern Cape amidst the thicket ecosystem, the municipality has grown and expanded over the recent past. The study spread over an 18-year period from 1994- 2012. Based on field surveys and SPOT imagery, built-up areas of BCMM was extracted for different periods. Data used for the study are census data for BCMM, 1994, 2000, 2006 and 2012 SPOT images, images of BCMM acquired from Google earth 2018. The rate of transformation of the area was calculated and it was higher compared to that of population growth. Based on this data urban growth are analysed with the assistance of landscape metrics that include Shannon entropy. The outcomes confirm that this metropolitan municipality has experienced sprawl and sprawl has done so at cumulative rate.
- Full Text:
- Date Issued: 2019
An assessment of the hydrologic response of the Keiskamma catchment to land use/cover changes
- Authors: Sive, Mlamla
- Date: 2019
- Subjects: Hydrological response
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44732 , vital:38165
- Description: The Keiskamma catchment has undergone significant land use/cover changes (LUCC) underpinned by land use policy reforms and climate change. However, the hydrological responses of the catchment to LUCC are not fully understood. This study sought to assess the hydrological response of the Keiskamma catchment to LUCC at catchment and hillslope scale using remote sensing, GIS, hydrological modelling and field experiments. Catchment scale assessments first involved LUCC mapping in IDRISI TerrSet software, using supervised image classification for two sets of multispectral imagery; namely Landsat Thematic Mapper (TM) of 1994 and Landsat 08 Operational Land Imager (OLI) of 2016. The LUCC maps provided an indication of LUCC over time and were prerequisite land use inputs for modelling the hydrologic response of the catchment. The Soil and Water Assessment Tool (SWAT) hydrologic model was used to model the hydrologic response of the catchment to LUCC. The Sequential Uncertainty Fitting (SUFI-2) in SWAT-CUP was used to assess model performance and uncertainty analysis. The influence of rainfall on the hydrologic response of the catchment was also assessed using linear regression. One of the prominent forms of LUCC in the Keiskamma catchment, particularly central Keiskamma is P. incana shrub encroachment. Field experiments were set up to investigate the hydrologic impacts of P. incana shrub invasion at hillslope scale, as well as to validate the results obtained by the SWAT hydrologic model. Field experiments included an assessment of the Landscape Organisation Index (LOI) of the invasion, as well as assessing of surface conditions, surface runoff (L), volumetric soil water content (cm³/cm³) and sediment loss (grams) under P. incana, grass and bare-eroded areas. High image classification accuracy assessment values of 87.2 % and 87.4 % for 1994 and 2016 respectively were obtained, with a Kappa coefficient of 0.84 for both sets of imagery. Results of the study revealed a significant increase in woody vegetation encroachment, specifically shrub invasion, forest expansion in the upper parts of the catchment, as well as an increase in exotic and invasive vegetation species within the riparian zone. The SWAT model showed a good (NSE=0.69, R²=0.69 and RSR =0.56) and unsatisfactory (NSE=0.4, R²=0.4 and RSR 0.79) model performance for calibration and validation respectively. However, for both the calibration (p-factor =0.77; r-factor 1.03) and validation (p-factor =0.92; r-factor 1.38) periods there was acceptable uncertainty as indicated by the p- and r-factor statistics. The mean annual streamflow (-71.4 %), surface runoff (-98.8 %), soil water content (-4.5 %), evapotranspiration (-5.3 %), groundwater (-79.5 %) and sediment loss (-99.9 %) decreased from 1994 to 2016. The impoundments in the catchment viz Cata, Mnyameni, Binfield, Sandile, Debe and Dimbaza dams, also contributed significantly to the streamflow reduction. A strong correlation (r= 0.61) between the declining streamflow (m3/s) and rainfall (mm) was observed. At hillslope scale, P. incana invasion was characterised by a low LOI, owing to large inter-shrub bare patches and poor soil surface conditions characterised by soil surface crusting, conducive to high runoff generation and connectivity. High surface runoff and soil losses were evident under P. incana and bare-eroded areas. Volumetric soil water content was high under grass and P. incana tussocks, intermediate in P. incana inter-patches and low in bare-eroded areas. The findings and analysis of this study conclude that the hydrologic response of the Keiskamma catchment was influenced significantly by LUCC in the form of extensive invader shrub encroachment, expansion of forestry using exotic tree species, impoundments, as well as the infestation of riparian zones by invasive vegetation. Management of woody shrub encroachment and alien invasive plants as well as indigenous forest species utilisation should be considered as amongst the key efforts towards restoring the ecohydrological integrity of the Keiskamma catchment.
- Full Text:
- Date Issued: 2019
- Authors: Sive, Mlamla
- Date: 2019
- Subjects: Hydrological response
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44732 , vital:38165
- Description: The Keiskamma catchment has undergone significant land use/cover changes (LUCC) underpinned by land use policy reforms and climate change. However, the hydrological responses of the catchment to LUCC are not fully understood. This study sought to assess the hydrological response of the Keiskamma catchment to LUCC at catchment and hillslope scale using remote sensing, GIS, hydrological modelling and field experiments. Catchment scale assessments first involved LUCC mapping in IDRISI TerrSet software, using supervised image classification for two sets of multispectral imagery; namely Landsat Thematic Mapper (TM) of 1994 and Landsat 08 Operational Land Imager (OLI) of 2016. The LUCC maps provided an indication of LUCC over time and were prerequisite land use inputs for modelling the hydrologic response of the catchment. The Soil and Water Assessment Tool (SWAT) hydrologic model was used to model the hydrologic response of the catchment to LUCC. The Sequential Uncertainty Fitting (SUFI-2) in SWAT-CUP was used to assess model performance and uncertainty analysis. The influence of rainfall on the hydrologic response of the catchment was also assessed using linear regression. One of the prominent forms of LUCC in the Keiskamma catchment, particularly central Keiskamma is P. incana shrub encroachment. Field experiments were set up to investigate the hydrologic impacts of P. incana shrub invasion at hillslope scale, as well as to validate the results obtained by the SWAT hydrologic model. Field experiments included an assessment of the Landscape Organisation Index (LOI) of the invasion, as well as assessing of surface conditions, surface runoff (L), volumetric soil water content (cm³/cm³) and sediment loss (grams) under P. incana, grass and bare-eroded areas. High image classification accuracy assessment values of 87.2 % and 87.4 % for 1994 and 2016 respectively were obtained, with a Kappa coefficient of 0.84 for both sets of imagery. Results of the study revealed a significant increase in woody vegetation encroachment, specifically shrub invasion, forest expansion in the upper parts of the catchment, as well as an increase in exotic and invasive vegetation species within the riparian zone. The SWAT model showed a good (NSE=0.69, R²=0.69 and RSR =0.56) and unsatisfactory (NSE=0.4, R²=0.4 and RSR 0.79) model performance for calibration and validation respectively. However, for both the calibration (p-factor =0.77; r-factor 1.03) and validation (p-factor =0.92; r-factor 1.38) periods there was acceptable uncertainty as indicated by the p- and r-factor statistics. The mean annual streamflow (-71.4 %), surface runoff (-98.8 %), soil water content (-4.5 %), evapotranspiration (-5.3 %), groundwater (-79.5 %) and sediment loss (-99.9 %) decreased from 1994 to 2016. The impoundments in the catchment viz Cata, Mnyameni, Binfield, Sandile, Debe and Dimbaza dams, also contributed significantly to the streamflow reduction. A strong correlation (r= 0.61) between the declining streamflow (m3/s) and rainfall (mm) was observed. At hillslope scale, P. incana invasion was characterised by a low LOI, owing to large inter-shrub bare patches and poor soil surface conditions characterised by soil surface crusting, conducive to high runoff generation and connectivity. High surface runoff and soil losses were evident under P. incana and bare-eroded areas. Volumetric soil water content was high under grass and P. incana tussocks, intermediate in P. incana inter-patches and low in bare-eroded areas. The findings and analysis of this study conclude that the hydrologic response of the Keiskamma catchment was influenced significantly by LUCC in the form of extensive invader shrub encroachment, expansion of forestry using exotic tree species, impoundments, as well as the infestation of riparian zones by invasive vegetation. Management of woody shrub encroachment and alien invasive plants as well as indigenous forest species utilisation should be considered as amongst the key efforts towards restoring the ecohydrological integrity of the Keiskamma catchment.
- Full Text:
- Date Issued: 2019