A geological, petrological and mineralogical study of the UG3 chromitite seam at Modikwa Platinum Mine : significance to exploration and PGE resources
- Authors: Machumele, Nkateko Jones
- Date: 2014
- Subjects: Modikwa Platinum Mine (South Africa) , Chromite -- South Africa -- Limpopo , Geology -- South Africa -- Limpopo , Petrology -- South Africa -- Limpopo , Mineralogy -- South Africa -- Limpopo , Platinum mines and mining -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5074 , http://hdl.handle.net/10962/d1013553
- Description: The UG3 at Modikwa Platinum Mine occurs as a platiniferous, planar chromitite seam. It is stratigraphically located in the Upper Critical Zone of the Eastern Bushveld Complex. Field work study comprise of underground mapping, sampling, surface mapping, borehole core logging, microprobing and microscopic investigations carried out at the Rhodes University. The UG3 at the Modikwa Platinum Mine is about 22cm thick chromitite seam underlain by a white fine grained anorthosite and overlain by a brown medium grained feldspathic pyroxenite. It is an incomplete cyclic unit consisting of chromite and feldspathic pyroxenite. The UG3 reef at the Modikwa Platinum Mine lease area represents a Platinum Group Metal resource of 300 million tons of ore at an in situ grade of 2.5g/t. Under the current market conditions the UG3 reef remains unprofitable to mine in an underground operation due to the operational cost involved. However, it has been illustrated that the UG3 chromitite seam can increase profit margins in an open pit operation provided it is mined together with the economic UG2 chromitite seam. The extraction of the UG3 as ore in the four Modikwa UG2 open pits would result in a combined operating cash profit of R330 million. The UG3 chromitite seam is platiniferous. The platinum-group minerals (PGM) range in size from less than 10μm to about 70μm. The PGMs are associated with sulphides and are both located in the interstitial silicates and are concentrated in the chromitite seam. The PGMs show a strong preference to contact boundaries of the silicate grains, the chromite grains and the sulphide phases. In some instances, they are enclosed within the chromite grains in association with sulphides. The general sulphide assemblage comprises pentlandite and chalcopyrite whereas, the PGMs assemblage comprises cooperite, ferroplatinum, laurite, FeRhS and PtRhS.
- Full Text:
- Date Issued: 2014
- Authors: Machumele, Nkateko Jones
- Date: 2014
- Subjects: Modikwa Platinum Mine (South Africa) , Chromite -- South Africa -- Limpopo , Geology -- South Africa -- Limpopo , Petrology -- South Africa -- Limpopo , Mineralogy -- South Africa -- Limpopo , Platinum mines and mining -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5074 , http://hdl.handle.net/10962/d1013553
- Description: The UG3 at Modikwa Platinum Mine occurs as a platiniferous, planar chromitite seam. It is stratigraphically located in the Upper Critical Zone of the Eastern Bushveld Complex. Field work study comprise of underground mapping, sampling, surface mapping, borehole core logging, microprobing and microscopic investigations carried out at the Rhodes University. The UG3 at the Modikwa Platinum Mine is about 22cm thick chromitite seam underlain by a white fine grained anorthosite and overlain by a brown medium grained feldspathic pyroxenite. It is an incomplete cyclic unit consisting of chromite and feldspathic pyroxenite. The UG3 reef at the Modikwa Platinum Mine lease area represents a Platinum Group Metal resource of 300 million tons of ore at an in situ grade of 2.5g/t. Under the current market conditions the UG3 reef remains unprofitable to mine in an underground operation due to the operational cost involved. However, it has been illustrated that the UG3 chromitite seam can increase profit margins in an open pit operation provided it is mined together with the economic UG2 chromitite seam. The extraction of the UG3 as ore in the four Modikwa UG2 open pits would result in a combined operating cash profit of R330 million. The UG3 chromitite seam is platiniferous. The platinum-group minerals (PGM) range in size from less than 10μm to about 70μm. The PGMs are associated with sulphides and are both located in the interstitial silicates and are concentrated in the chromitite seam. The PGMs show a strong preference to contact boundaries of the silicate grains, the chromite grains and the sulphide phases. In some instances, they are enclosed within the chromite grains in association with sulphides. The general sulphide assemblage comprises pentlandite and chalcopyrite whereas, the PGMs assemblage comprises cooperite, ferroplatinum, laurite, FeRhS and PtRhS.
- Full Text:
- Date Issued: 2014
A goal-setting intervention with motocross racers : a case study investigating the effects of an intervention on perceived motivation, confidence, and self-efficacy
- Authors: Fleming, Tracey Laura
- Date: 2014
- Subjects: Motocross -- Psychological aspects -- Research , Motorcyclists -- Psychological aspects -- Research , Goal (Psychology) -- Research , Competition (Psychology) -- Research , Motivation (Psychology) -- Case studies , Confidence -- Case studies , Self-efficacy -- Case studies , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3224 , http://hdl.handle.net/10962/d1012996
- Description: This study aimed to investigate the effects that a specifically tailored goal-setting program would have on two motocross racers in terms of their self-efficacy and motivation, as well as the process of designing this intervention. This case-study approach involved a mixed methods approach, consisting of pre-intervention and post-intervention assessments, interviews, and performance profiles. The tools used include Vealey’s (1986) Competitive Orientation Inventory (COI), Gill and Deeter’s (1988) Sport Orientation Questionnaire (SOQ), performance profiles, and semi-structured interviews. The goal-setting intervention lasted a total of five weeks. The results from the preintervention and post-intervention assessments were compared to determine whether any changes in motivation or self-efficacy occurred during the intervention. For the first participant, significant changes in both motivation and self-efficacy were present in addition to significant changes in competitive orientation. For the second participant, there were no significant changes in either motivation or self-efficacy. However, for the second participant there was also no change in competitive orientation. Findings suggest that the focus and competitive orientation of an athlete have a significant influence on the types of goals set, and consequently on positive changes in motivation, confidence, and self-efficacy. The influence of the competitive orientation in athletes also highlighted the importance of attaining a balance between performance and outcome goal-related activities. It was also discovered through qualitative assessment that this program is suitable for particular groups of athletes such as those who are injured, display an external locus of causality or are otherwise not performing at their prime.
- Full Text:
- Date Issued: 2014
- Authors: Fleming, Tracey Laura
- Date: 2014
- Subjects: Motocross -- Psychological aspects -- Research , Motorcyclists -- Psychological aspects -- Research , Goal (Psychology) -- Research , Competition (Psychology) -- Research , Motivation (Psychology) -- Case studies , Confidence -- Case studies , Self-efficacy -- Case studies , Sports -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3224 , http://hdl.handle.net/10962/d1012996
- Description: This study aimed to investigate the effects that a specifically tailored goal-setting program would have on two motocross racers in terms of their self-efficacy and motivation, as well as the process of designing this intervention. This case-study approach involved a mixed methods approach, consisting of pre-intervention and post-intervention assessments, interviews, and performance profiles. The tools used include Vealey’s (1986) Competitive Orientation Inventory (COI), Gill and Deeter’s (1988) Sport Orientation Questionnaire (SOQ), performance profiles, and semi-structured interviews. The goal-setting intervention lasted a total of five weeks. The results from the preintervention and post-intervention assessments were compared to determine whether any changes in motivation or self-efficacy occurred during the intervention. For the first participant, significant changes in both motivation and self-efficacy were present in addition to significant changes in competitive orientation. For the second participant, there were no significant changes in either motivation or self-efficacy. However, for the second participant there was also no change in competitive orientation. Findings suggest that the focus and competitive orientation of an athlete have a significant influence on the types of goals set, and consequently on positive changes in motivation, confidence, and self-efficacy. The influence of the competitive orientation in athletes also highlighted the importance of attaining a balance between performance and outcome goal-related activities. It was also discovered through qualitative assessment that this program is suitable for particular groups of athletes such as those who are injured, display an external locus of causality or are otherwise not performing at their prime.
- Full Text:
- Date Issued: 2014
A hybrid model for managing personal health records in South Africa
- Authors: Kyazze, Michael
- Date: 2014
- Subjects: Cloud computing -- South Africa , Information storage and retrieval systems -- Medical care -- South Africa , Medical records -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3145 , vital:20403
- Description: Doctors can experience difficulty in accessing medical information of new patients. One reason for this is that the management of medical records is mostly institution-centred. The lack of access to medical information may negatively affect patients in several ways. These include new medical tests that may need to be carried out at a cost to the patient and doctors prescribing drugs to which the patient is allergic. This research investigates how patients can play an active role in sharing their personal health records (PHRs) with doctors located in geographically separate areas. In order to achieve the goal of this research, existing literature concerning medical health records and standards was reviewed. A literature review of techniques that can be used to ensure privacy of health information was also undertaken. Interview studies were carried out with three medical practices in Port Elizabeth with the aim of contextualising the findings from the literature study. The Design Science Research methodology was used for this research. A Hybrid Model for Managing Personal Health Records in South Africa is proposed. This model allows patients to view their PHRs on their mobile phones and medical practitioners to manage the patients’ PHRs using a web-based application. The patients’ PHR information is stored both on a cloud server and on mobile devices hence the hybrid nature. Two prototypes were developed as a proof of concept; a mobile application for the patients and a web-based application for the medical practitioners. A field study was carried out with the NMMU health services department and 12 participants over a period of two weeks. The results of the field study were highly positive. The successful evaluation of the prototypes provides empirical evidence that the proposed model brings us closer to the realisation of ubiquitous access to PHRS in South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Kyazze, Michael
- Date: 2014
- Subjects: Cloud computing -- South Africa , Information storage and retrieval systems -- Medical care -- South Africa , Medical records -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3145 , vital:20403
- Description: Doctors can experience difficulty in accessing medical information of new patients. One reason for this is that the management of medical records is mostly institution-centred. The lack of access to medical information may negatively affect patients in several ways. These include new medical tests that may need to be carried out at a cost to the patient and doctors prescribing drugs to which the patient is allergic. This research investigates how patients can play an active role in sharing their personal health records (PHRs) with doctors located in geographically separate areas. In order to achieve the goal of this research, existing literature concerning medical health records and standards was reviewed. A literature review of techniques that can be used to ensure privacy of health information was also undertaken. Interview studies were carried out with three medical practices in Port Elizabeth with the aim of contextualising the findings from the literature study. The Design Science Research methodology was used for this research. A Hybrid Model for Managing Personal Health Records in South Africa is proposed. This model allows patients to view their PHRs on their mobile phones and medical practitioners to manage the patients’ PHRs using a web-based application. The patients’ PHR information is stored both on a cloud server and on mobile devices hence the hybrid nature. Two prototypes were developed as a proof of concept; a mobile application for the patients and a web-based application for the medical practitioners. A field study was carried out with the NMMU health services department and 12 participants over a period of two weeks. The results of the field study were highly positive. The successful evaluation of the prototypes provides empirical evidence that the proposed model brings us closer to the realisation of ubiquitous access to PHRS in South Africa.
- Full Text:
- Date Issued: 2014
A hybridisation technique for game playing using the upper confidence for trees algorithm with artificial neural networks
- Authors: Burger, Clayton
- Date: 2014
- Subjects: Neural networks (Computer science) , Computer algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3957 , vital:20495
- Description: In the domain of strategic game playing, the use of statistical techniques such as the Upper Confidence for Trees (UCT) algorithm, has become the norm as they offer many benefits over classical algorithms. These benefits include requiring no game-specific strategic knowledge and time-scalable performance. UCT does not incorporate any strategic information specific to the game considered, but instead uses repeated sampling to effectively brute-force search through the game tree or search space. The lack of game-specific knowledge in UCT is thus both a benefit but also a strategic disadvantage. Pattern recognition techniques, specifically Neural Networks (NN), were identified as a means of addressing the lack of game-specific knowledge in UCT. Through a novel hybridisation technique which combines UCT and trained NNs for pruning, the UCTNN algorithm was derived. The NN component of UCT-NN was trained using a UCT self-play scheme to generate game-specific knowledge without the need to construct and manage game databases for training purposes. The UCT-NN algorithm is outlined for pruning in the game of Go-Moku as a candidate case-study for this research. The UCT-NN algorithm contained three major parameters which emerged from the UCT algorithm, the use of NNs and the pruning schemes considered. Suitable methods for finding candidate values for these three parameters were outlined and applied to the game of Go-Moku on a 5 by 5 board. An empirical investigation of the playing performance of UCT-NN was conducted in comparison to UCT through three benchmarks. The benchmarks comprise a common randomly moving opponent, a common UCTmax player which is given a large amount of playing time, and a pair-wise tournament between UCT-NN and UCT. The results of the performance evaluation for 5 by 5 Go-Moku were promising, which prompted an evaluation of a larger 9 by 9 Go-Moku board. The results of both evaluations indicate that the time allocated to the UCT-NN algorithm directly affects its performance when compared to UCT. The UCT-NN algorithm generally performs better than UCT in games with very limited time-constraints in all benchmarks considered except when playing against a randomly moving player in 9 by 9 Go-Moku. In real-time and near-real-time Go-Moku games, UCT-NN provides statistically significant improvements compared to UCT. The findings of this research contribute to the realisation of applying game-specific knowledge to the UCT algorithm.
- Full Text:
- Date Issued: 2014
- Authors: Burger, Clayton
- Date: 2014
- Subjects: Neural networks (Computer science) , Computer algorithms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3957 , vital:20495
- Description: In the domain of strategic game playing, the use of statistical techniques such as the Upper Confidence for Trees (UCT) algorithm, has become the norm as they offer many benefits over classical algorithms. These benefits include requiring no game-specific strategic knowledge and time-scalable performance. UCT does not incorporate any strategic information specific to the game considered, but instead uses repeated sampling to effectively brute-force search through the game tree or search space. The lack of game-specific knowledge in UCT is thus both a benefit but also a strategic disadvantage. Pattern recognition techniques, specifically Neural Networks (NN), were identified as a means of addressing the lack of game-specific knowledge in UCT. Through a novel hybridisation technique which combines UCT and trained NNs for pruning, the UCTNN algorithm was derived. The NN component of UCT-NN was trained using a UCT self-play scheme to generate game-specific knowledge without the need to construct and manage game databases for training purposes. The UCT-NN algorithm is outlined for pruning in the game of Go-Moku as a candidate case-study for this research. The UCT-NN algorithm contained three major parameters which emerged from the UCT algorithm, the use of NNs and the pruning schemes considered. Suitable methods for finding candidate values for these three parameters were outlined and applied to the game of Go-Moku on a 5 by 5 board. An empirical investigation of the playing performance of UCT-NN was conducted in comparison to UCT through three benchmarks. The benchmarks comprise a common randomly moving opponent, a common UCTmax player which is given a large amount of playing time, and a pair-wise tournament between UCT-NN and UCT. The results of the performance evaluation for 5 by 5 Go-Moku were promising, which prompted an evaluation of a larger 9 by 9 Go-Moku board. The results of both evaluations indicate that the time allocated to the UCT-NN algorithm directly affects its performance when compared to UCT. The UCT-NN algorithm generally performs better than UCT in games with very limited time-constraints in all benchmarks considered except when playing against a randomly moving player in 9 by 9 Go-Moku. In real-time and near-real-time Go-Moku games, UCT-NN provides statistically significant improvements compared to UCT. The findings of this research contribute to the realisation of applying game-specific knowledge to the UCT algorithm.
- Full Text:
- Date Issued: 2014
A lignocellulolytic enzyme system for fruit waste degradation : commercial enzyme mixture synergy and bioreactor design
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014
- Authors: Gama, Repson
- Date: 2014
- Subjects: Enzymes -- Biotechnology , Enzymes -- Industrial applications , Lignocellulose -- Biodegradation , Biomass energy , Biomass conversion , Biochemical engineering , Agricultural wastes as fuel
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4114 , http://hdl.handle.net/10962/d1013073
- Description: Studies into sources of alternative liquid transport fuel energy have identified agro-industrial wastes, which are lignocellulosic in nature, as a potential feedstock for biofuel production against the background of depleting nonrenewable fossil fuels. In South Africa, large quantities of apple and other fruit wastes, called pomace, are generated from fruit and juice industries. Apple pomace is a rich source of cellulose, pectin and hemicellulose, making it a potential target for utilisation as a lignocellulosic feedstock for biofuel and biorefinery chemical production. Lignocellulosic biomass is recalcitrant in nature and therefore its degradation requires the synergistic action of a number of enzymes such as cellulases, hemicellulases, pectinases and ligninases. Commercial enzyme cocktails, containing some of these enzymes, are available and can be used for apple pomace degradation. In this study, the degradation of apple pomace using commercial enzyme cocktails was investigated. The main focus was the optimisation of the release of sugar monomers that could potentially be used for biofuel and biorefinery chemical production. There is no or little information reported in literature on the enzymatic degradation of fruit waste using commercial enzyme mixtures. This study first focused on the characterisation of the substrate (apple pomace) and the commercial enzyme cocktails. Apple pomace was found to contain mainly glucose, galacturonic acid, arabinose, galactose, lignin and low amounts of xylose and fructose. Three commercial enzyme cocktails were initially selected: Biocip Membrane, Viscozyme L (from Aspergillus aculeatus) and Celluclast 1.5L (a Trichoderma reesei ATCC 26921 cellulase preparation). The selection of the enzymes was based on activities declared by the manufacturers, cost and local availability. The enzymes were screened based on their synergistic cooperation in the degradation of apple pomace and the main enzymes present in each cocktail. Viscozyme L and Celluclast 1.5L, in a 50:50 ratio, resulted in the best degree of synergy (1.6) compared to any other combination. The enzyme ratios were determined on Viscozyme L and Celluclast 1.5L based on the protein ratio. Enzyme activity was determined as glucose equivalents using the dinitrosalicylic acid (DNS) method. Sugar monomers were determined using Megazyme assay kits. There is limited information available on the enzymes present in the commercial enzyme cocktails. Therefore, the main enzymes present in Viscozyme L and Celluclast 1.5L were identified using different substrates, each targeted for a specific enzyme and activity. Characterisation of the enzyme mixtures revealed a large number of enzymes required for apple pomace degradation and these included cellulases, pectinases, xylanases, arabinases and mannanases in different proportions. Viscozyme L contained mainly pectinases and hemicellulases, while Celluclast 1.5L displayed largely cellulase and xylanase activity, hence the high degree of synergy reported. The temperature optimum was 50ºC for both enzyme mixtures and pH optima were observed at pH 5.0 and pH 3.0 for Viscozyme L and Celluclast 1.5L, respectively. At 37ºC and pH 5.0, the enzymes retained more that 90% activity after 15 days of incubation, allowing the enzymes to be used together with less energy input. The enzymes were further characterised by determining the effect of various compounds, such as alcohols, sugars, phenolic compounds and metal ions at various concentrations on the activity of the enzymes during apple pomace hydrolysis. Apart from lignin, which had almost no effect on enzyme activity, all the compounds caused inhibition of the enzymes to varying degrees. The most inhibitory compounds were some organic acids and metal ions, as well as cellobiose and xylobiose. Using the best ratio for Viscozyme L and Celluclast 1.5L (50:50) for the hydrolysis of apple pomace, it was observed that synergy was highest at the initial stages of hydrolysis and decreased over time, though the sugar concentration increased. The type of synergy for optimal apple pomace hydrolysis was found to be simultaneous. There was no synergy observed between Viscozyme L and Celluclast 1.5L with ligninases - laccase, lignin peroxidase and manganese peroxidase. Hydrolysing apple pomace with ligninases prior to addition of Viscozyme L and Celluclast 1.5L did not improve degradation of the substrate. Immobilisation of the enzyme mixtures on different supports was performed with the aim of increasing stability and enabling reuse of the enzymes. Immobilisation methods were selected based on the chemical properties of the supports, availability, cost and applicability on heterogeneous and insoluble substrate like apple pomace. These methods included crosslinked enzyme aggregates (CLEAs), immobilisation on various supports such as nylon mesh, nylon beads, sodium alginate beads, chitin and silica gel beads. The immobilisation strategies were unsuccessful, mainly due to the low percentage of immobilisation of the enzyme on the matrix and loss of activity of the immobilised enzyme. Free enzymes were therefore used for the remainder of the study. Hydrolysis conditions for apple pomace degradation were optimised using different temperatures and buffer systems in 1 L volumes mixed with compressed air. Hydrolysis at room temperature, using an unbuffered system, gave a better performance as compared to a buffered system. Reactors operated in batch mode performed better (4.2 g/L (75% yield) glucose and 16.8 g/L (75%) reducing sugar) than fed-batch reactors (3.2 g/L (66%) glucose and 14.6 g/L (72.7% yield) reducing sugar) over 100 h using Viscozyme L and Celluclast 1.5L. Supplementation of β- glucosidase activity in Viscozyme L and Celluclast 1.5L with Novozyme 188 resulted in a doubling of the amount of glucose released. The main products released from apple pomace hydrolysis were galacturonic acid, glucose and arabinose and low amounts of galactose and xylose. These products are potential raw materials for biofuel and biorefinery chemical production. An artificial neural network (ANN) model was successfully developed and used for predicting the optimum conditions for apple pomace hydrolysis using Celluclast 1.5L, Viscozyme L and Novozyme 188. Four main conditions that affect apple pomace hydrolysis were selected, namely temperature, initial pH, enzyme loading and substrate loading, which were taken as inputs. The glucose and reducing sugars released as a result of each treatment and their combinations were taken as outputs for 1–100 h. An ANN with 20, 20 and 6 neurons in the first, second and third hidden layers, respectively, was constructed. The performance and predictive ability of the ANN was good, with a R² of 0.99 and a small mean square error (MSE). New data was successfully predicted and simulated. Optimal hydrolysis conditions predicted by ANN for apple pomace hydrolysis were at 30% substrate (wet w/v) and an enzyme loading of 0.5 mg/g and 0.2 mg/mL of substrate for glucose and reducing sugar, respectively, giving sugar concentrations of 6.5 mg/mL and 28.9 mg/mL for glucose and reducing sugar, respectively. ANN showed that enzyme and substrate loadings were the most important factors for the hydrolysis of apple pomace.
- Full Text:
- Date Issued: 2014
A mathematics rendering model to support chat-based tutoring
- Authors: Haskins, Bertram Peter
- Date: 2014
- Subjects: Intelligent tutoring systems , Educational innovations , Tutors and tutoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9822 , http://hdl.handle.net/10948/d1020567
- Description: Dr Math is a math tutoring service implemented on the chat application Mxit. The service allows school learners to use their mobile phones to discuss mathematicsrelated topics with human tutors. Using the broad user-base provided by Mxit, the Dr Math service has grown to consist of tens of thousands of registered school learners. The tutors on the service are all volunteers and the learners far outnumber the available tutors at any given time. School learners on the service use a shorthand language-form called microtext, to phrase their queries. Microtext is an informal form of language which consists of a variety of misspellings and symbolic representations, which emerge spontaneously as a result of the idiosyncrasies of a learner. The specific form of microtext found on the Dr Math service contains mathematical questions and example equations, pertaining to the tutoring process. Deciphering the queries, to discover their embedded mathematical content, slows down the tutoring process. This wastes time that could have been spent addressing more learner queries. The microtext language thus creates an unnecessary burden on the tutors. This study describes the development of an automated process for the translation of Dr Math microtext queries into mathematical equations. Using the design science research paradigm as a guide, three artefacts are developed. These artefacts take the form of a construct, a model and an instantiation. The construct represents the creation of new knowledge as it provides greater insight into the contents and structure of the language found on a mobile mathematics tutoring service. The construct serves as the basis for the creation of a model for the translation of microtext queries into mathematical equations, formatted for display in an electronic medium. No such technique currently exists and therefore, the model contributes new knowledge. To validate the model, an instantiation was created to serve as a proof-of-concept. The instantiation applies various concepts and techniques, such as those related to natural language processing, to the learner queries on the Dr Math service. These techniques are employed in order to translate an input microtext statement into a mathematical equation, structured by using mark-up language. The creation of the instantiation thus constitutes a knowledge contribution, as most of these techniques have never been applied to the problem of translating microtext into mathematical equations. For the automated process to have utility, it should perform on a level comparable to that of a human performing a similar translation task. To determine how closely related the results from the automated process are to those of a human, three human participants were asked to perform coding and translation tasks. The results of the human participants were compared to the results of the automated process, across a variety of metrics, including agreement, correlation, precision, recall and others. The results from the human participants served as the baseline values for comparison. The baseline results from the human participants were compared with those of the automated process. Krippendorff’s α was used to determine the level of agreement and Pearson’s correlation coefficient to determine the level of correlation between the results. The agreement between the human participants and the automated process was calculated at a level deemed satisfactory for exploratory research and the level of correlation was calculated as moderate. These values correspond with the calculations made as the human baseline. Furthermore, the automated process was able to meet or improve on all of the human baseline metrics. These results serve to validate that the automated process is able to perform the translation at a level comparable to that of a human. The automated process is available for integration into any requesting application, by means of a publicly accessible web service.
- Full Text:
- Date Issued: 2014
- Authors: Haskins, Bertram Peter
- Date: 2014
- Subjects: Intelligent tutoring systems , Educational innovations , Tutors and tutoring
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9822 , http://hdl.handle.net/10948/d1020567
- Description: Dr Math is a math tutoring service implemented on the chat application Mxit. The service allows school learners to use their mobile phones to discuss mathematicsrelated topics with human tutors. Using the broad user-base provided by Mxit, the Dr Math service has grown to consist of tens of thousands of registered school learners. The tutors on the service are all volunteers and the learners far outnumber the available tutors at any given time. School learners on the service use a shorthand language-form called microtext, to phrase their queries. Microtext is an informal form of language which consists of a variety of misspellings and symbolic representations, which emerge spontaneously as a result of the idiosyncrasies of a learner. The specific form of microtext found on the Dr Math service contains mathematical questions and example equations, pertaining to the tutoring process. Deciphering the queries, to discover their embedded mathematical content, slows down the tutoring process. This wastes time that could have been spent addressing more learner queries. The microtext language thus creates an unnecessary burden on the tutors. This study describes the development of an automated process for the translation of Dr Math microtext queries into mathematical equations. Using the design science research paradigm as a guide, three artefacts are developed. These artefacts take the form of a construct, a model and an instantiation. The construct represents the creation of new knowledge as it provides greater insight into the contents and structure of the language found on a mobile mathematics tutoring service. The construct serves as the basis for the creation of a model for the translation of microtext queries into mathematical equations, formatted for display in an electronic medium. No such technique currently exists and therefore, the model contributes new knowledge. To validate the model, an instantiation was created to serve as a proof-of-concept. The instantiation applies various concepts and techniques, such as those related to natural language processing, to the learner queries on the Dr Math service. These techniques are employed in order to translate an input microtext statement into a mathematical equation, structured by using mark-up language. The creation of the instantiation thus constitutes a knowledge contribution, as most of these techniques have never been applied to the problem of translating microtext into mathematical equations. For the automated process to have utility, it should perform on a level comparable to that of a human performing a similar translation task. To determine how closely related the results from the automated process are to those of a human, three human participants were asked to perform coding and translation tasks. The results of the human participants were compared to the results of the automated process, across a variety of metrics, including agreement, correlation, precision, recall and others. The results from the human participants served as the baseline values for comparison. The baseline results from the human participants were compared with those of the automated process. Krippendorff’s α was used to determine the level of agreement and Pearson’s correlation coefficient to determine the level of correlation between the results. The agreement between the human participants and the automated process was calculated at a level deemed satisfactory for exploratory research and the level of correlation was calculated as moderate. These values correspond with the calculations made as the human baseline. Furthermore, the automated process was able to meet or improve on all of the human baseline metrics. These results serve to validate that the automated process is able to perform the translation at a level comparable to that of a human. The automated process is available for integration into any requesting application, by means of a publicly accessible web service.
- Full Text:
- Date Issued: 2014
A method for the evaluation of similarity measures on graphs and network-structured data
- Authors: Naude, Kevin Alexander
- Date: 2014
- Subjects: Graph theory , Network analysis (Planning)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10494
- Description: Measures of similarity play a subtle but important role in a large number of disciplines. For example, a researcher in bioinformatics may devise a new computed measure of similarity between biological structures, and use its scores to infer bio-logical association. Other academics may use related approaches in structured text search, or for object recognition in computer vision. These are diverse and practical applications of similarity. A critical question is this: to what extent can a given similarity measure be trusted? This is a difficult problem, at the heart of which lies the broader issue: what exactly constitutes good similarity judgement? This research presents the view that similarity measures have properties of judgement that are intrinsic to their formulation, and that such properties are measurable. The problem of comparing similarity measures is one of identifying ground-truths for similarity. The approach taken in this work is to examine the relative ordering of graph pairs, when compared with respect to a common reference graph. Ground- truth outcomes are obtained from a novel theory: the theory of irreducible change in graphs. This theory supports stronger claims than those made for edit distances. Whereas edit distances are sensitive to a configuration of costs, irreducible change under the new theory is independent of such parameters. Ground-truth data is obtained by isolating test cases for which a common outcome is assured for all possible least measures of change that can be formulated within a chosen change descriptor space. By isolating these specific cases, and excluding others, the research introduces a framework for evaluating similarity measures on mathematically defensible grounds. The evaluation method is demonstrated in a series of case studies which evaluate the similarity performance of known graph similarity measures. The findings of these experiments provide the first general characterisation of common similarity measures over a wide range of graph properties. The similarity computed from the maximum common induced subgraph (Dice-MCIS) is shown to provide good general similarity judgement. However, it is shown that Blondel's similarity measure can exceed the judgement sensitivity of Dice-MCIS, provided the graphs have both sufficient attribute label diversity, and edge density. The final contribution is the introduction of a new similarity measure for graphs, which is shown to have statistically greater judgement sensitivity than all other measures examined. All of these findings are made possible through the theory of irreducible change in graphs. The research provides the first mathematical basis for reasoning about the quality of similarity judgments. This enables researchers to analyse similarity measures directly, making similarity measures first class objects of scientific inquiry.
- Full Text:
- Date Issued: 2014
- Authors: Naude, Kevin Alexander
- Date: 2014
- Subjects: Graph theory , Network analysis (Planning)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:10494
- Description: Measures of similarity play a subtle but important role in a large number of disciplines. For example, a researcher in bioinformatics may devise a new computed measure of similarity between biological structures, and use its scores to infer bio-logical association. Other academics may use related approaches in structured text search, or for object recognition in computer vision. These are diverse and practical applications of similarity. A critical question is this: to what extent can a given similarity measure be trusted? This is a difficult problem, at the heart of which lies the broader issue: what exactly constitutes good similarity judgement? This research presents the view that similarity measures have properties of judgement that are intrinsic to their formulation, and that such properties are measurable. The problem of comparing similarity measures is one of identifying ground-truths for similarity. The approach taken in this work is to examine the relative ordering of graph pairs, when compared with respect to a common reference graph. Ground- truth outcomes are obtained from a novel theory: the theory of irreducible change in graphs. This theory supports stronger claims than those made for edit distances. Whereas edit distances are sensitive to a configuration of costs, irreducible change under the new theory is independent of such parameters. Ground-truth data is obtained by isolating test cases for which a common outcome is assured for all possible least measures of change that can be formulated within a chosen change descriptor space. By isolating these specific cases, and excluding others, the research introduces a framework for evaluating similarity measures on mathematically defensible grounds. The evaluation method is demonstrated in a series of case studies which evaluate the similarity performance of known graph similarity measures. The findings of these experiments provide the first general characterisation of common similarity measures over a wide range of graph properties. The similarity computed from the maximum common induced subgraph (Dice-MCIS) is shown to provide good general similarity judgement. However, it is shown that Blondel's similarity measure can exceed the judgement sensitivity of Dice-MCIS, provided the graphs have both sufficient attribute label diversity, and edge density. The final contribution is the introduction of a new similarity measure for graphs, which is shown to have statistically greater judgement sensitivity than all other measures examined. All of these findings are made possible through the theory of irreducible change in graphs. The research provides the first mathematical basis for reasoning about the quality of similarity judgments. This enables researchers to analyse similarity measures directly, making similarity measures first class objects of scientific inquiry.
- Full Text:
- Date Issued: 2014
A mobile phone solution for ad-hoc hitch-hiking in South Africa
- Authors: Miteche, Sacha Patrick
- Date: 2014
- Subjects: Cell phones -- Information services , Cell phone users -- South Africa , Hitchhiking -- South Africa , Mobile communication systems -- Social aspects , Digital media -- South Africa , Information technology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4702 , http://hdl.handle.net/10962/d1013340
- Description: The purpose of this study was to investigate the use of mobile phones in organizing ad-hoc vehicle ridesharing based on hitch-hiking trips involving private car drivers and commuters in South Africa. A study was conducted to learn how hitch-hiking trips are arranged in the urban and rural areas of the Eastern Cape. This involved carrying out interviews with hitch-hikers and participating in several trips. The study results provided the design specifications for a Dynamic Ridesharing System (DRS) tailor-made to the hitch-hiking culture of this context. The design of the DRS considered the delivery of the ad-hoc ridesharing service to the anticipated mobile phones owned by people who use hitch-hiking. The implementation of the system used the available open source solutions and guidelines under the Siyakhula Living Lab project, which promotes the use of Information and Communication Technology (ICT) in marginalized communities of South Africa. The developed prototype was tested in both the simulated and live environments, then followed by usability tests to establish the viability of the system. The results from the tests indicate an initial breakthrough in the process of modernizing the ad-hoc ridesharing of hitch-hiking which is used by a section of people in the urban and rural areas of South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Miteche, Sacha Patrick
- Date: 2014
- Subjects: Cell phones -- Information services , Cell phone users -- South Africa , Hitchhiking -- South Africa , Mobile communication systems -- Social aspects , Digital media -- South Africa , Information technology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4702 , http://hdl.handle.net/10962/d1013340
- Description: The purpose of this study was to investigate the use of mobile phones in organizing ad-hoc vehicle ridesharing based on hitch-hiking trips involving private car drivers and commuters in South Africa. A study was conducted to learn how hitch-hiking trips are arranged in the urban and rural areas of the Eastern Cape. This involved carrying out interviews with hitch-hikers and participating in several trips. The study results provided the design specifications for a Dynamic Ridesharing System (DRS) tailor-made to the hitch-hiking culture of this context. The design of the DRS considered the delivery of the ad-hoc ridesharing service to the anticipated mobile phones owned by people who use hitch-hiking. The implementation of the system used the available open source solutions and guidelines under the Siyakhula Living Lab project, which promotes the use of Information and Communication Technology (ICT) in marginalized communities of South Africa. The developed prototype was tested in both the simulated and live environments, then followed by usability tests to establish the viability of the system. The results from the tests indicate an initial breakthrough in the process of modernizing the ad-hoc ridesharing of hitch-hiking which is used by a section of people in the urban and rural areas of South Africa.
- Full Text:
- Date Issued: 2014
A model for attaining extended e-commerce adoption and use by hospitality smmes in the Eastern Cape Province
- Authors: Maoneke, Pardon Blessings
- Date: 2014
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11147 , http://hdl.handle.net/10353/d1017897
- Description: There is a slow adoption and use of electronic commerce or e-Commerce by Small, Medium and Micro-sized Enterprises based in the hospitality sector (hospitality SMMEs). Only a few hospitality SMMEs that have adopted e-Commerce show the migration of value adding activities to their e-Commerce platforms. As such, this study developed and proposed a model that shows how hospitality SMMEs in the Eastern Cape Province can attain extended e-Commerce adoption and use. Extended e-Commerce platforms are characterised by the institutionalization of e-Commerce that includes Search Engine Marketing activities and/or listing services on intermediary websites, and engaging through social media websites. Tourism and hospitality customers’ information needs and buying behaviour were used to guide the requirements of extended e-Commerce platforms for hospitality businesses. The proposed model outlined factors determining extended e-Commerce adoption, extended e-Commerce characteristics and the anticipated e-Commerce adoption outcomes. The model was evaluated in the Eastern Cape using a multiple-case study methodology. The study’s use of a multiple-case study was applied within the interpretivist paradigm and four cases were considered. Triangulation through document analysis, interviews and observation was used for collecting data regarding factors determining the transition to extended e-Commerce adoption. A questionnaire was used for evaluating extended e-Commerce use. Within and cross-case analysis with the aid of coding was used for data analysis. Data collection and analysis validated the proposed model as a model that shows how hospitality SMMEs can attain extended e-Commerce adoption and use. The proposed model concedes that, successful adoption and use of e-Commerce by hospitality SMMEs would result in e-Commerce adoption outcomes namely online sales, reservations and customer service. These e-Commerce adoption outcomes are the criteria against which the level of extended e-Commerce adoption is measured.
- Full Text:
- Date Issued: 2014
- Authors: Maoneke, Pardon Blessings
- Date: 2014
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11147 , http://hdl.handle.net/10353/d1017897
- Description: There is a slow adoption and use of electronic commerce or e-Commerce by Small, Medium and Micro-sized Enterprises based in the hospitality sector (hospitality SMMEs). Only a few hospitality SMMEs that have adopted e-Commerce show the migration of value adding activities to their e-Commerce platforms. As such, this study developed and proposed a model that shows how hospitality SMMEs in the Eastern Cape Province can attain extended e-Commerce adoption and use. Extended e-Commerce platforms are characterised by the institutionalization of e-Commerce that includes Search Engine Marketing activities and/or listing services on intermediary websites, and engaging through social media websites. Tourism and hospitality customers’ information needs and buying behaviour were used to guide the requirements of extended e-Commerce platforms for hospitality businesses. The proposed model outlined factors determining extended e-Commerce adoption, extended e-Commerce characteristics and the anticipated e-Commerce adoption outcomes. The model was evaluated in the Eastern Cape using a multiple-case study methodology. The study’s use of a multiple-case study was applied within the interpretivist paradigm and four cases were considered. Triangulation through document analysis, interviews and observation was used for collecting data regarding factors determining the transition to extended e-Commerce adoption. A questionnaire was used for evaluating extended e-Commerce use. Within and cross-case analysis with the aid of coding was used for data analysis. Data collection and analysis validated the proposed model as a model that shows how hospitality SMMEs can attain extended e-Commerce adoption and use. The proposed model concedes that, successful adoption and use of e-Commerce by hospitality SMMEs would result in e-Commerce adoption outcomes namely online sales, reservations and customer service. These e-Commerce adoption outcomes are the criteria against which the level of extended e-Commerce adoption is measured.
- Full Text:
- Date Issued: 2014
A model for security incident response in the South African National Research and Education network
- Authors: Mooi, Roderick David
- Date: 2014
- Subjects: Information networks -- South Africa , Internet -- Security measures , Computer networks -- Security measures -- South Africa , National Research and Education Network (Computer network)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9813 , http://hdl.handle.net/10948/d1017598
- Description: This dissertation addresses the problem of a lack of a formal incident response capability in the South African National Research and Education Network (SA NREN). While investigating alternatives it was found that no clear method exists to solve this problem. Therefore, a second problem is identified: the lack of a definitive method for establishing a Computer Security Incident Response Team (CSIRT) or Computer Emergency Response Team (CERT) in general. Solving the second problem is important as we then have a means of knowing how to start when building a CSIRT. This will set the basis for addressing the initial problem, resulting in a prepared, improved and coordinated response to IT security incidents affecting the SANREN. To commence, the requirements for establishing a CSIRT are identified via a comprehensive literature review. These requirements are categorized into five areas, namely, the basic business requirements followed by the four Ps of the IT Infrastructure Library (ITIL). That is, People, Processes, Product and Partners, adapted to suit the CSIRT context. Through the use of argumentation, the relationships between the areas are uncovered and explored. Thereafter, a Design Science Research-based process is utilised to develop a generic model for establishing a CSIRT. The model is based on the interactions uncovered between the business requirements and the adapted four Ps. These are summarised through two views -- strategic and tactical -- together forming an holistic model for establishing a CSIRT. The model highlights the decisions required for the business requirements, services, team model and staff, policies and processes, tools and technologies, and partners of a CSIRT respectively. Finally, to address the primary objective, the generic model is applied to the SANREN environment. Thus, the second artefact is an instantiation, a specific model, which can be implemented to create a CSIRT for the SA NREN. To produce the specific model, insight into the nature of the SANREN environment was required. The status quo was revealed through the use of a survey and argumentative analysis of the results. The specific decisions in each area required to establish an SA NREN CSIRT are explored throughout the development of the model. The result is a comprehensive framework for implementing a CSIRT in the SA NREN, detailing the decisions required in each of the areas. This model additionally acts as a demonstration of the utility of the generic model. The implications of this research are twofold. Firstly, the generic model is useful as a basis for anyone wanting to establish a CSIRT. It helps to ensure that all factors are considered and that no important decisions are neglected, thereby enabling an holistic view. Secondly, the specific model for the SA NREN CSIRT serves as a foundation for implementing the CSIRT going forward. It accelerates the process by addressing the important considerations and highlighting the concerns that must be addressed while establishing the CSIRT.
- Full Text:
- Date Issued: 2014
- Authors: Mooi, Roderick David
- Date: 2014
- Subjects: Information networks -- South Africa , Internet -- Security measures , Computer networks -- Security measures -- South Africa , National Research and Education Network (Computer network)
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9813 , http://hdl.handle.net/10948/d1017598
- Description: This dissertation addresses the problem of a lack of a formal incident response capability in the South African National Research and Education Network (SA NREN). While investigating alternatives it was found that no clear method exists to solve this problem. Therefore, a second problem is identified: the lack of a definitive method for establishing a Computer Security Incident Response Team (CSIRT) or Computer Emergency Response Team (CERT) in general. Solving the second problem is important as we then have a means of knowing how to start when building a CSIRT. This will set the basis for addressing the initial problem, resulting in a prepared, improved and coordinated response to IT security incidents affecting the SANREN. To commence, the requirements for establishing a CSIRT are identified via a comprehensive literature review. These requirements are categorized into five areas, namely, the basic business requirements followed by the four Ps of the IT Infrastructure Library (ITIL). That is, People, Processes, Product and Partners, adapted to suit the CSIRT context. Through the use of argumentation, the relationships between the areas are uncovered and explored. Thereafter, a Design Science Research-based process is utilised to develop a generic model for establishing a CSIRT. The model is based on the interactions uncovered between the business requirements and the adapted four Ps. These are summarised through two views -- strategic and tactical -- together forming an holistic model for establishing a CSIRT. The model highlights the decisions required for the business requirements, services, team model and staff, policies and processes, tools and technologies, and partners of a CSIRT respectively. Finally, to address the primary objective, the generic model is applied to the SANREN environment. Thus, the second artefact is an instantiation, a specific model, which can be implemented to create a CSIRT for the SA NREN. To produce the specific model, insight into the nature of the SANREN environment was required. The status quo was revealed through the use of a survey and argumentative analysis of the results. The specific decisions in each area required to establish an SA NREN CSIRT are explored throughout the development of the model. The result is a comprehensive framework for implementing a CSIRT in the SA NREN, detailing the decisions required in each of the areas. This model additionally acts as a demonstration of the utility of the generic model. The implications of this research are twofold. Firstly, the generic model is useful as a basis for anyone wanting to establish a CSIRT. It helps to ensure that all factors are considered and that no important decisions are neglected, thereby enabling an holistic view. Secondly, the specific model for the SA NREN CSIRT serves as a foundation for implementing the CSIRT going forward. It accelerates the process by addressing the important considerations and highlighting the concerns that must be addressed while establishing the CSIRT.
- Full Text:
- Date Issued: 2014
A model of creative and innovative techniques that will prepare final year students to become entrepreneurs
- Authors: Yiadom, Michael Boakye
- Date: 2014
- Subjects: Technological innovations -- Economic aspects , Entrepreneurship -- Study and teaching
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/3812 , vital:20465
- Description: Creativity and innovation are significant for the creation of a knowledge and productive base economy with its associated growth, sustainability and job creation. However it is noticed that students will need to employ the techniques on creativity and innovation in order to prepare themselves sufficiently to become business owners and entrepreneurs in this current global world where government jobs are difficult to come by. Therefore, the primary objective of this study is to determine creative and innovative techniques that will prepare final-year students to become entrepreneurs. A hard copy Word document questionnaire was considered an appropriate measurement method for this study. The targeted population of the study included entrepreneurial experts, business owners, teachers and lecturers of business management/studies in the Sisonke District of Kwazulu Natal Province. Thus, some 100 entrepreneur experts, owners of businesses, teachers and lecturers were identified as part of the sampling frame. A total number of 67 questionnaires were administered out of the 100 targeted– giving a response rate of 67%. The quantitative data were processed using Excel, leading to appropriate descriptive statistical analyses, including frequencies, means, medians and standard deviations. In order to obtain a better understanding of a model that will prepare final year students to become entrepreneurs, problem statements and sub-problems were stated and a t-test was used to establish demographic variables, whilst correlation analysis among skills was conducted regarding the model of creative and innovative techniques. Factor analysis was conducted using the Cronbach’s alpha coefficient which confirms that training in the model will prepare students to become entrepreneurs. The results from the empirical study revealed that a model of creative and innovative techniques will prepare students to become entrepreneurs, with a total of 70% of respondents attesting to it. Based on the relevant literature study and the empirical results, recommendations were made in order to support the training needs of students on creativity and innovation techniques. However, the unavailability of an exhaustive entrepreneurial experts database and small number of further education and training colleges in the Sisonke District, did not allow the research to draw on a larger representative sample. Thus, this limitation has impeded in-depth statistical analysis that would have allowed the research to obtain more accurate findings. Further studies could be investigated from lecturers, business owners and experts whether an introduction of a special curriculum on creativity and innovation in further education and training schools may prepare students to become entrepreneurs.
- Full Text:
- Date Issued: 2014
- Authors: Yiadom, Michael Boakye
- Date: 2014
- Subjects: Technological innovations -- Economic aspects , Entrepreneurship -- Study and teaching
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/3812 , vital:20465
- Description: Creativity and innovation are significant for the creation of a knowledge and productive base economy with its associated growth, sustainability and job creation. However it is noticed that students will need to employ the techniques on creativity and innovation in order to prepare themselves sufficiently to become business owners and entrepreneurs in this current global world where government jobs are difficult to come by. Therefore, the primary objective of this study is to determine creative and innovative techniques that will prepare final-year students to become entrepreneurs. A hard copy Word document questionnaire was considered an appropriate measurement method for this study. The targeted population of the study included entrepreneurial experts, business owners, teachers and lecturers of business management/studies in the Sisonke District of Kwazulu Natal Province. Thus, some 100 entrepreneur experts, owners of businesses, teachers and lecturers were identified as part of the sampling frame. A total number of 67 questionnaires were administered out of the 100 targeted– giving a response rate of 67%. The quantitative data were processed using Excel, leading to appropriate descriptive statistical analyses, including frequencies, means, medians and standard deviations. In order to obtain a better understanding of a model that will prepare final year students to become entrepreneurs, problem statements and sub-problems were stated and a t-test was used to establish demographic variables, whilst correlation analysis among skills was conducted regarding the model of creative and innovative techniques. Factor analysis was conducted using the Cronbach’s alpha coefficient which confirms that training in the model will prepare students to become entrepreneurs. The results from the empirical study revealed that a model of creative and innovative techniques will prepare students to become entrepreneurs, with a total of 70% of respondents attesting to it. Based on the relevant literature study and the empirical results, recommendations were made in order to support the training needs of students on creativity and innovation techniques. However, the unavailability of an exhaustive entrepreneurial experts database and small number of further education and training colleges in the Sisonke District, did not allow the research to draw on a larger representative sample. Thus, this limitation has impeded in-depth statistical analysis that would have allowed the research to obtain more accurate findings. Further studies could be investigated from lecturers, business owners and experts whether an introduction of a special curriculum on creativity and innovation in further education and training schools may prepare students to become entrepreneurs.
- Full Text:
- Date Issued: 2014
A needs-ICTD strategy alignment framework foundation for the measurement of ICTD impact
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2014
- Subjects: Siyakhula Living Lab SAP Research Needs assessment -- Information technology -- Social aspects -- South Africa -- Case studies Information technology -- South Africa -- Management -- Case studies Information technology -- Social aspects -- South Africa Rural development -- Economic aspects -- South Africa Rural development -- South Africa -- Sociological aspects Rural development projects -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1155 , http://hdl.handle.net/10962/d1011116
- Description: Many Information and Communication Technologies for Development (ICTD) projects are established with the overall aim of positively developing the communities they are implemented in. However, the solutions that are provided are often commonly developed without the needs of these communities being sufficiently investigated beforehand. As a result the ICTD strategy of the project ends up not well aligned with the aims and targets of the needs of the community. As a result of this, an appropriate programme theory for the project and relevant impact indicators fail to be adequately developed. Consequently, when an impact assessment is conducted it is often found that the intended effects are not directly linked to the needs of the community or what the community had hoped to gain from the ICTD initiative. The purpose of this research serves to develop a needs-ICTD strategy alignment foundation that supports the identification and formulation of impact assessment indicators. Through this research, a framework is developed to support the alignment of ICTD strategy, the development and the promotion of contextual needs of rural communities and other frequently marginalized areas. The Needs-ICTD strategy alignment framework is composed of eight main components that describe the process that can be used to align ICTD strategy with community needs. These components include: collaboration between the internal and external stakeholders, the development of the community, conducting baseline studies, the needs assessment, the ICTD strategy, linking of the needs-ICTD strategy, and lastly the identification of impact indicators. An interpretive research approach is used to explore and inform the framework through a multi-case study investigation of the Siyakhula Living Lab and two projects in the Systems Application Products (SAP) Living Lab. Two main case study questions drive the exploration of the framework, that being: 1) How are the needs of the community elicited and how is the ICTD strategy aligned to the needs of the community? 2) And, why were the selected approaches chosen for aligning the needs of the community and ICTD strategy? Data for this research was collected qualitatively through interviews, document analysis and participant observation. Key findings indicate that the involvement of internal (local) stakeholders in the development and alignment of ICTD strategy to the needs of the community is still lacking. As a consequence, many community members end up not fully understanding the project objectives and how these objectives aims are to be achieved. The research also finds that ‘solution specific’ projects also fail communities as they focus specifically on one target group and repeatedly fail to assist the community holistically in supporting their information and their community development needs.
- Full Text:
- Date Issued: 2014
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2014
- Subjects: Siyakhula Living Lab SAP Research Needs assessment -- Information technology -- Social aspects -- South Africa -- Case studies Information technology -- South Africa -- Management -- Case studies Information technology -- Social aspects -- South Africa Rural development -- Economic aspects -- South Africa Rural development -- South Africa -- Sociological aspects Rural development projects -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1155 , http://hdl.handle.net/10962/d1011116
- Description: Many Information and Communication Technologies for Development (ICTD) projects are established with the overall aim of positively developing the communities they are implemented in. However, the solutions that are provided are often commonly developed without the needs of these communities being sufficiently investigated beforehand. As a result the ICTD strategy of the project ends up not well aligned with the aims and targets of the needs of the community. As a result of this, an appropriate programme theory for the project and relevant impact indicators fail to be adequately developed. Consequently, when an impact assessment is conducted it is often found that the intended effects are not directly linked to the needs of the community or what the community had hoped to gain from the ICTD initiative. The purpose of this research serves to develop a needs-ICTD strategy alignment foundation that supports the identification and formulation of impact assessment indicators. Through this research, a framework is developed to support the alignment of ICTD strategy, the development and the promotion of contextual needs of rural communities and other frequently marginalized areas. The Needs-ICTD strategy alignment framework is composed of eight main components that describe the process that can be used to align ICTD strategy with community needs. These components include: collaboration between the internal and external stakeholders, the development of the community, conducting baseline studies, the needs assessment, the ICTD strategy, linking of the needs-ICTD strategy, and lastly the identification of impact indicators. An interpretive research approach is used to explore and inform the framework through a multi-case study investigation of the Siyakhula Living Lab and two projects in the Systems Application Products (SAP) Living Lab. Two main case study questions drive the exploration of the framework, that being: 1) How are the needs of the community elicited and how is the ICTD strategy aligned to the needs of the community? 2) And, why were the selected approaches chosen for aligning the needs of the community and ICTD strategy? Data for this research was collected qualitatively through interviews, document analysis and participant observation. Key findings indicate that the involvement of internal (local) stakeholders in the development and alignment of ICTD strategy to the needs of the community is still lacking. As a consequence, many community members end up not fully understanding the project objectives and how these objectives aims are to be achieved. The research also finds that ‘solution specific’ projects also fail communities as they focus specifically on one target group and repeatedly fail to assist the community holistically in supporting their information and their community development needs.
- Full Text:
- Date Issued: 2014
A new approach to obesity for health journalism: fit not fat
- Authors: Dugmore, Harry
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158620 , vital:40212 , https://hdl.handle.net/10520/EJC159484
- Description: Health journalism is a complicated beat. The science is easy to get wrong, and the tone and tenor of the reporting needs careful attention. Coverage of obesity is even more fraught. Early insights from an on-going research project by the Discovery Centre for Health Journalism suggests that not only is most journalism about obesity not helping - some reporting may inadvertently be making the situation worse. This needs to change. There is too much at stake for journalism about food, fat and fitness to be anything less than impactful and effective.
- Full Text:
- Date Issued: 2014
- Authors: Dugmore, Harry
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158620 , vital:40212 , https://hdl.handle.net/10520/EJC159484
- Description: Health journalism is a complicated beat. The science is easy to get wrong, and the tone and tenor of the reporting needs careful attention. Coverage of obesity is even more fraught. Early insights from an on-going research project by the Discovery Centre for Health Journalism suggests that not only is most journalism about obesity not helping - some reporting may inadvertently be making the situation worse. This needs to change. There is too much at stake for journalism about food, fat and fitness to be anything less than impactful and effective.
- Full Text:
- Date Issued: 2014
A new approach to representations of revolution
- Authors: Burke, Matthew Ainslie
- Date: 2014
- Subjects: Radicalism in literature , Radicalism in literature -- Moral and ethical aspects , Politics and literature -- Moral and ethical aspects , Revolutionary literature, English
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2310 , http://hdl.handle.net/10962/d1013068
- Description: This project asserts that revolution is characterised by the expression of unthinkable possibilities, and so addresses the paradox implicit in any attempt to "write revolution." That is, how does one represent revolution without reducing it to an ordered term of reference, and thereby subduing its radical character? Additionally, can transformative action be conceptualised as a creative project to which an ethical subject may, and in fact should, be drawn? To answer these questions, my investigation develops in three strands. I combine the radical theory of Alain Badiou with similar affirmations of revolutionary intervention from Slavoj Žižek and Paulo Freire, and so create an aesthetic that affirms revolutionaries as agents of supplementary creativity. My first purpose is thus to establish revolution as a productive enterprise that enables peace, rather than a destructive undertaking that introduces violence. This done, I apply the resultant conceptual tools to literary representations of radical transformation, and demonstrate that my aesthetic enables new readings of the literature of revolution to which it is applied. In the course of my analysis, I also evaluate the suitability of Badiou's ethic as a standpoint from which to engage with literature on revolution. Ultimately, then, the aesthetic I construct not only contests the notion that radical transformation is always destructive, but also renders one sensitive to revolutionary literature's excessive and supplementary dimensions.
- Full Text:
- Date Issued: 2014
- Authors: Burke, Matthew Ainslie
- Date: 2014
- Subjects: Radicalism in literature , Radicalism in literature -- Moral and ethical aspects , Politics and literature -- Moral and ethical aspects , Revolutionary literature, English
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2310 , http://hdl.handle.net/10962/d1013068
- Description: This project asserts that revolution is characterised by the expression of unthinkable possibilities, and so addresses the paradox implicit in any attempt to "write revolution." That is, how does one represent revolution without reducing it to an ordered term of reference, and thereby subduing its radical character? Additionally, can transformative action be conceptualised as a creative project to which an ethical subject may, and in fact should, be drawn? To answer these questions, my investigation develops in three strands. I combine the radical theory of Alain Badiou with similar affirmations of revolutionary intervention from Slavoj Žižek and Paulo Freire, and so create an aesthetic that affirms revolutionaries as agents of supplementary creativity. My first purpose is thus to establish revolution as a productive enterprise that enables peace, rather than a destructive undertaking that introduces violence. This done, I apply the resultant conceptual tools to literary representations of radical transformation, and demonstrate that my aesthetic enables new readings of the literature of revolution to which it is applied. In the course of my analysis, I also evaluate the suitability of Badiou's ethic as a standpoint from which to engage with literature on revolution. Ultimately, then, the aesthetic I construct not only contests the notion that radical transformation is always destructive, but also renders one sensitive to revolutionary literature's excessive and supplementary dimensions.
- Full Text:
- Date Issued: 2014
A Note on the (Continued) Ability of the Yield Curve to Forecast Economic Downturns in South Africa
- Authors: Botha, Ferdi , Keeton, Gavin
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/395994 , vital:69142 , xlink:href="https://doi.org/10.1111/saje.12053"
- Description: In 2002-2003, the South African yield spread falsely signalled a downswing that never materialised. This paper provides two reasons for this false signal. First, while the Reserve Bank never actually officially declared the start of a downswing, by alternative measures a downswing did actually occur. It is this severe weakness in economic activity at that time that the yield curve pointed to. Second, short-term interest rates in 2003 were higher than they should have been because of a mistake made in measuring consumer price inflation. Because South Africa had recently introduced an inflation-targeting regime, policy interest rates were, as a result of this error, kept too high for too long. This policy mistake was rectified as soon as the error in the Consumer Price Index was discovered. Thus, the yield curve in 2003 pointed to the reality that short-term interest rates were too high and risked pushing the economy into full blown recession. This is demonstrated by the fact that it was a fall in long bond interest rates that caused the yield spread to turn negative, indicating expectations that short-term interest rates would need to be cut – as indeed they were.
- Full Text:
- Date Issued: 2014
- Authors: Botha, Ferdi , Keeton, Gavin
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/395994 , vital:69142 , xlink:href="https://doi.org/10.1111/saje.12053"
- Description: In 2002-2003, the South African yield spread falsely signalled a downswing that never materialised. This paper provides two reasons for this false signal. First, while the Reserve Bank never actually officially declared the start of a downswing, by alternative measures a downswing did actually occur. It is this severe weakness in economic activity at that time that the yield curve pointed to. Second, short-term interest rates in 2003 were higher than they should have been because of a mistake made in measuring consumer price inflation. Because South Africa had recently introduced an inflation-targeting regime, policy interest rates were, as a result of this error, kept too high for too long. This policy mistake was rectified as soon as the error in the Consumer Price Index was discovered. Thus, the yield curve in 2003 pointed to the reality that short-term interest rates were too high and risked pushing the economy into full blown recession. This is demonstrated by the fact that it was a fall in long bond interest rates that caused the yield spread to turn negative, indicating expectations that short-term interest rates would need to be cut – as indeed they were.
- Full Text:
- Date Issued: 2014
A phenomenological study of the experiences of adolescents following maternal HIV-disclosure
- Sibanyoni, Sibongile Success
- Authors: Sibanyoni, Sibongile Success
- Date: 2014
- Subjects: HIV infections -- Transmission -- South Africa -- Grahamstown , HIV-positive youth -- South Africa -- Grahamstown , Teenagers -- Diseases -- South Africa -- Grahamstown , HIV infections -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3231 , http://hdl.handle.net/10962/d1013125
- Description: Maternal HIV-disclosure to an adolescent is a controversial issue especially when considering the suitable time and context in which disclosure should take place. Furthermore there have been other considerations such as the adolescent’s emotional maturity as well as gender issues which have played a role in regards to determining whether the adolescent would be able to understand and cope effectively post-disclosure. These considerations formed the basis of this study’s aim and objectives which primarily focused on taking into account the developmental aspects apparent in the adolescent phase. These include adolescent’s relations with their mother, their peers and the meaning attached to having an education and career in their lives. For purposes of this study it was deemed important to actually explore with the adolescent’s the meaning they uphold pertaining to maternal HIVdisclosure. This differs from previous research which has focused predominantly on accessing adolescent’s experiences via their parents and in particular, their mothers. Data of only three participants was included following in-depth interviews being conducted. Data was analysed via Interpretive Phenomenological Analysis (IPA) which enabled an enhanced understanding and meaningful interpretation of the adolescent’s experiences following maternal HIV-disclosure. From the findings it became apparent that most concerns had already been addressed and were similar when compared to previous research that had been conducted. However one notable different finding was that instead of adolescent’s acting in ways that would lead to them self-sabotaging their lives they instead portrayed themselves to be living in a responsible manner. It became apparent rather that it was the adolescent’s mother rather that became more inclined to engage in self-sabotaging behaviours.
- Full Text:
- Date Issued: 2014
- Authors: Sibanyoni, Sibongile Success
- Date: 2014
- Subjects: HIV infections -- Transmission -- South Africa -- Grahamstown , HIV-positive youth -- South Africa -- Grahamstown , Teenagers -- Diseases -- South Africa -- Grahamstown , HIV infections -- Social aspects -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3231 , http://hdl.handle.net/10962/d1013125
- Description: Maternal HIV-disclosure to an adolescent is a controversial issue especially when considering the suitable time and context in which disclosure should take place. Furthermore there have been other considerations such as the adolescent’s emotional maturity as well as gender issues which have played a role in regards to determining whether the adolescent would be able to understand and cope effectively post-disclosure. These considerations formed the basis of this study’s aim and objectives which primarily focused on taking into account the developmental aspects apparent in the adolescent phase. These include adolescent’s relations with their mother, their peers and the meaning attached to having an education and career in their lives. For purposes of this study it was deemed important to actually explore with the adolescent’s the meaning they uphold pertaining to maternal HIVdisclosure. This differs from previous research which has focused predominantly on accessing adolescent’s experiences via their parents and in particular, their mothers. Data of only three participants was included following in-depth interviews being conducted. Data was analysed via Interpretive Phenomenological Analysis (IPA) which enabled an enhanced understanding and meaningful interpretation of the adolescent’s experiences following maternal HIV-disclosure. From the findings it became apparent that most concerns had already been addressed and were similar when compared to previous research that had been conducted. However one notable different finding was that instead of adolescent’s acting in ways that would lead to them self-sabotaging their lives they instead portrayed themselves to be living in a responsible manner. It became apparent rather that it was the adolescent’s mother rather that became more inclined to engage in self-sabotaging behaviours.
- Full Text:
- Date Issued: 2014
A phenominological study of young adults' experiences of facebook
- Authors: Prince, Inge
- Date: 2014
- Subjects: Teenagers -- Social networks , Online social networks , Internet -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9979 , http://hdl.handle.net/10948/d1021116
- Description: Social networking sites are a recent phenomenon and have experienced tremendous growth in popularity especially among young people. Social networking sites are changing the way individuals communicate with each other and the world. Social networking sites (SNS) provide users with a unique computer-mediated environment where individuals are able to disclose their thoughts, feelings, and experiences within their own social network. The present study aims to explore the experiences of young adults regarding Facebook. A transcendental phenomenological approach was used to elicit the essence of the experiences of the participants. Theoretical sampling ensured relevant participants were selected through haphazard sampling procedures. Data was collected through the use of biographical questionnaires and individual, semi-structured interviews. The data was processed according to the four phenomenological principles epoche, phenomenological reduction, imaginative variation and synthesis using Tesch’s eight steps. Lincoln and Guba’s model was used to assess the trustworthiness of the data obtained. The participants described their experiences of Facebook by highlighting how they use Facebook as a communication tool which assists them in their relationship maintenance with others. Participants use self-presentation on Facebook to manage how they are perceived. The participants experience Facebook as having many privacy risks. They indicated that Facebook has addictive qualities and facilitates cyber stalking behaviour.
- Full Text:
- Date Issued: 2014
- Authors: Prince, Inge
- Date: 2014
- Subjects: Teenagers -- Social networks , Online social networks , Internet -- Social aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9979 , http://hdl.handle.net/10948/d1021116
- Description: Social networking sites are a recent phenomenon and have experienced tremendous growth in popularity especially among young people. Social networking sites are changing the way individuals communicate with each other and the world. Social networking sites (SNS) provide users with a unique computer-mediated environment where individuals are able to disclose their thoughts, feelings, and experiences within their own social network. The present study aims to explore the experiences of young adults regarding Facebook. A transcendental phenomenological approach was used to elicit the essence of the experiences of the participants. Theoretical sampling ensured relevant participants were selected through haphazard sampling procedures. Data was collected through the use of biographical questionnaires and individual, semi-structured interviews. The data was processed according to the four phenomenological principles epoche, phenomenological reduction, imaginative variation and synthesis using Tesch’s eight steps. Lincoln and Guba’s model was used to assess the trustworthiness of the data obtained. The participants described their experiences of Facebook by highlighting how they use Facebook as a communication tool which assists them in their relationship maintenance with others. Participants use self-presentation on Facebook to manage how they are perceived. The participants experience Facebook as having many privacy risks. They indicated that Facebook has addictive qualities and facilitates cyber stalking behaviour.
- Full Text:
- Date Issued: 2014
A preliminary assessment linking altered catchment land-cover to the health of four temporarily open/closed South African estuaries
- Authors: Masefield, Vincent Antony
- Date: 2014
- Subjects: Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4877 , http://hdl.handle.net/10962/d1013096
- Description: Estuaries worldwide are being subjected to various degrees of catchment degradation, which is having severe consequences on the integrity of these aquatic ecosystems and their ability to function properly. This thesis investigated the relationship between catchment land-cover and estuarine health in four temporarily open/closed estuarine systems (TOCEs) in South Africa, namely the Groot Brak, East Kleinemonde, Mdloti and Tongati. GIS techniques were employed to delineate catchments, lower sections of catchments, 1 km and 100 m buffer zones, and to quantify the extent of land-cover classes present within these delineations. Anthropogenic activities outlined by the Department of Water Affairs and Forestry (DWAF) Resource Directed Measures (RDM) studies and their associated land-cover classes were described. The possible links between catchment and buffer zone land-cover class composition and health of the estuaries were explored. Results indicated that there was a relationship between catchment and estuarine health within the Coastal Protection Zone (CPZ) (1 km and 100 m) buffers, but not at a broader catchment level. Out of natural, urban built-up and cultivation land-cover classes, natural land was determined to be the best predictor of estuarine health within the CPZs. A method of rapidly assessing South African TOCE condition was applied and could be used to prioritise these estuaries for rehabilitation and/or conservation.
- Full Text:
- Date Issued: 2014
- Authors: Masefield, Vincent Antony
- Date: 2014
- Subjects: Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4877 , http://hdl.handle.net/10962/d1013096
- Description: Estuaries worldwide are being subjected to various degrees of catchment degradation, which is having severe consequences on the integrity of these aquatic ecosystems and their ability to function properly. This thesis investigated the relationship between catchment land-cover and estuarine health in four temporarily open/closed estuarine systems (TOCEs) in South Africa, namely the Groot Brak, East Kleinemonde, Mdloti and Tongati. GIS techniques were employed to delineate catchments, lower sections of catchments, 1 km and 100 m buffer zones, and to quantify the extent of land-cover classes present within these delineations. Anthropogenic activities outlined by the Department of Water Affairs and Forestry (DWAF) Resource Directed Measures (RDM) studies and their associated land-cover classes were described. The possible links between catchment and buffer zone land-cover class composition and health of the estuaries were explored. Results indicated that there was a relationship between catchment and estuarine health within the Coastal Protection Zone (CPZ) (1 km and 100 m) buffers, but not at a broader catchment level. Out of natural, urban built-up and cultivation land-cover classes, natural land was determined to be the best predictor of estuarine health within the CPZs. A method of rapidly assessing South African TOCE condition was applied and could be used to prioritise these estuaries for rehabilitation and/or conservation.
- Full Text:
- Date Issued: 2014
A promising biological control agent for the invasive alien plant, Pereskia aculeata Miller (Cactaceae), in South Africa
- Paterson, Iain D, Mdodana, Lumka A, Mpekula, Ongezwa, Mabunda, Bheki D, Hill, Martin P
- Authors: Paterson, Iain D , Mdodana, Lumka A , Mpekula, Ongezwa , Mabunda, Bheki D , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416806 , vital:71387 , xlink:href="https://doi.org/10.1080/09583157.2014.919439"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien plant from Central and South America that has become a problematic environmental weed in South Africa. A potential biological control agent, the stem-wilter, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), was collected in southern Brazil and imported into quarantine in South Africa. Field host range data suggested that C. schaffneri has a host range restricted to P. aculeata. No-choice nymph survival tests were then conducted on 27 test plant species in 9 families. Survival to the adult stage was only recorded on P. aculeata and the closely related Pereskia grandifolia Haw. (Cactaceae). Mortality was significantly higher on P. grandifolia with only 3% of the nymphs reaching the adult stage compared with 74% on P. aculeata indicating that P. aculeata is the primary host plant. P. grandifolia is native in South America and is of no agricultural importance in South Africa so any feeding on P. grandifolia in South Africa would have no negative environmental or economic consequences. In other tests, adult survival on P. aculeata [25.8 days (SE ± 3.74)] was significantly longer than on other test plant species [4.3 days (SE ± 0.36)] further confirming the host specificity of the species. Impact studies conducted in quarantine indicated that C. schaffneri is damaging to P. aculeata, significantly reducing the number of leaves and the shoot lengths of plants, even at relatively low insect densities. C. schaffneri is safe for release in South Africa and is likely to be a damaging and effective agent.
- Full Text:
- Date Issued: 2014
- Authors: Paterson, Iain D , Mdodana, Lumka A , Mpekula, Ongezwa , Mabunda, Bheki D , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416806 , vital:71387 , xlink:href="https://doi.org/10.1080/09583157.2014.919439"
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien plant from Central and South America that has become a problematic environmental weed in South Africa. A potential biological control agent, the stem-wilter, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), was collected in southern Brazil and imported into quarantine in South Africa. Field host range data suggested that C. schaffneri has a host range restricted to P. aculeata. No-choice nymph survival tests were then conducted on 27 test plant species in 9 families. Survival to the adult stage was only recorded on P. aculeata and the closely related Pereskia grandifolia Haw. (Cactaceae). Mortality was significantly higher on P. grandifolia with only 3% of the nymphs reaching the adult stage compared with 74% on P. aculeata indicating that P. aculeata is the primary host plant. P. grandifolia is native in South America and is of no agricultural importance in South Africa so any feeding on P. grandifolia in South Africa would have no negative environmental or economic consequences. In other tests, adult survival on P. aculeata [25.8 days (SE ± 3.74)] was significantly longer than on other test plant species [4.3 days (SE ± 0.36)] further confirming the host specificity of the species. Impact studies conducted in quarantine indicated that C. schaffneri is damaging to P. aculeata, significantly reducing the number of leaves and the shoot lengths of plants, even at relatively low insect densities. C. schaffneri is safe for release in South Africa and is likely to be a damaging and effective agent.
- Full Text:
- Date Issued: 2014
A psychobiographical study of Antwone Fisher
- Authors: Wannenburg, Nicola
- Date: 2014
- Subjects: Fisher, Antwone Quenton , Psychology -- Biographical methods , Psychoanalysis , Abused children -- Biography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3219 , http://hdl.handle.net/10962/d1012939
- Description: Psychobiographical researchers methodically formulate life histories and interpret them by means of psychological theories. The research typically focuses on exemplary and completed lives. The cases that are studied are usually of individuals who are of particular interest to society as a result of excelling in their particular fields, be they to society’s benefit or detriment. Antwone Fisher was chosen for this study using purposive sampling as he meets the psychobiographical requirement of being an extraordinary individual. Fisher grew up in the Foster Care System and faced many abusive experiences as child. Despite difficult beginnings, Fisher developed into a stable and creative adult who excels as a poet, screenwriter and film director. The primary aim of this study is to describe and interpret the life of Antwone Fisher through Erikson’s theory of psychosocial development. The data was processed and analysed using Miles and Hubermans’ general view of qualitative analyses as well as Alexander’s method of asking the data questions. This study contributes to the development of psychobiographical research in South Africa as well as to personality and developmental theory.
- Full Text:
- Date Issued: 2014
- Authors: Wannenburg, Nicola
- Date: 2014
- Subjects: Fisher, Antwone Quenton , Psychology -- Biographical methods , Psychoanalysis , Abused children -- Biography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3219 , http://hdl.handle.net/10962/d1012939
- Description: Psychobiographical researchers methodically formulate life histories and interpret them by means of psychological theories. The research typically focuses on exemplary and completed lives. The cases that are studied are usually of individuals who are of particular interest to society as a result of excelling in their particular fields, be they to society’s benefit or detriment. Antwone Fisher was chosen for this study using purposive sampling as he meets the psychobiographical requirement of being an extraordinary individual. Fisher grew up in the Foster Care System and faced many abusive experiences as child. Despite difficult beginnings, Fisher developed into a stable and creative adult who excels as a poet, screenwriter and film director. The primary aim of this study is to describe and interpret the life of Antwone Fisher through Erikson’s theory of psychosocial development. The data was processed and analysed using Miles and Hubermans’ general view of qualitative analyses as well as Alexander’s method of asking the data questions. This study contributes to the development of psychobiographical research in South Africa as well as to personality and developmental theory.
- Full Text:
- Date Issued: 2014