The use of gabions as a tool for ecological engineering
- Authors: Seath, Jessica Lauren
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434987 , vital:73121
- Description: Anthropogenic activities are centred in coastal ecosystems, including the development of harbours and/or marinas. The artificial structures used in coastal development typically has a different composition, orientation and level of complexity to that of natural ecosystems contributing to loss of biodiversity and increased incidence of invasive species. Ecological engineering research is attempting to identify different types of structures and materials that can increase species diversity and target species of conservation concern in coastal systems. The aim of this study was to investigate the efficacy of gabions (rock filled structures) as an ecological engineering tool by comparing community structure on these structures with pre-existing seawall structures within a small harbour and marina in South Africa (Knysna Harbour). The objectives of the study were to compare the differences in; 1) fish and; 2) colonising organisms’ diversity and composition between two artificial structures. Thirteen gabion boxes were deployed in Knysna Harbour and together with corresponding seawalls, monitored quarterly over a period of 12 months (August 2020 – August 2021) to assess taxon and functional richness, diversity, abundance and composition of fish, invertebrate and algal species. Physico-chemical characteristics of the water body were also monitored quarterly. Remote underwater video systems were used to quantify MaxN (maximum number of a fish species in the frame at any one time during each set that gives an indication of relative abundance) and identify fish species. The results of the two-way crossed ANOVAs indicated that gabion habitats recruited greater numbers and more types of fish species and from more functional groups than the seawalls, especially omnivorous and carnivorous fish. Additionally, photoquadrats were used to quantify percentage cover, counts and to identify colonising taxa. The results of the two-way crossed ANOVAs indicated that gabions hosted greater numbers of species resulting in a higher overall diversity and abundance of colonising organisms than seawalls. By contrast, the seawalls supported more types of functional groups of colonising organisms than gabions, largely due to abundances of different algal species. The results from the crossed PERMANOVAs indicated that the composition of fish and colonising organisms were vastly different from one another, and that each habitat was supporting very different functional groups. Results indicate that whilst both gabions and seawalls contain several alien species, that the ratio of native to alien species is higher in gabion habitats. Additionally, this research observed that gabion structures hosted four species listed on the IUCN Red List of Threatened Species. This study has highlighted that the use of gabions (with their natural increased complexity) could be important to consider for the future of urban coastal development in harbours such as in Knysna Harbour. Ecological engineering projects using gabions have the potential to be used in South Africa in projects that aim at increasing biodiversity in urban coastal environments. As well as increasing the settlement and abundance of habitat-forming ecosystem engineers to ensure the long-term stability of these ecosystems. They can be used both in the development of new costal development projects as well as in an ad-hoc fashion where they can be interspersed on seawalls in harbours. Additionally, gabions have the potential to be used in projects that target species of conservation concern such as the endangered Knysna Seahorse (Hippocampus capensis). It is, however, important to monitor the invasion by non-native species in future ecological engineering projects in South Africa as well as their potential for creating ecological traps (a situation in which an organism may be convinced to settle in a low-quality habitat) for certain species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Seath, Jessica Lauren
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434987 , vital:73121
- Description: Anthropogenic activities are centred in coastal ecosystems, including the development of harbours and/or marinas. The artificial structures used in coastal development typically has a different composition, orientation and level of complexity to that of natural ecosystems contributing to loss of biodiversity and increased incidence of invasive species. Ecological engineering research is attempting to identify different types of structures and materials that can increase species diversity and target species of conservation concern in coastal systems. The aim of this study was to investigate the efficacy of gabions (rock filled structures) as an ecological engineering tool by comparing community structure on these structures with pre-existing seawall structures within a small harbour and marina in South Africa (Knysna Harbour). The objectives of the study were to compare the differences in; 1) fish and; 2) colonising organisms’ diversity and composition between two artificial structures. Thirteen gabion boxes were deployed in Knysna Harbour and together with corresponding seawalls, monitored quarterly over a period of 12 months (August 2020 – August 2021) to assess taxon and functional richness, diversity, abundance and composition of fish, invertebrate and algal species. Physico-chemical characteristics of the water body were also monitored quarterly. Remote underwater video systems were used to quantify MaxN (maximum number of a fish species in the frame at any one time during each set that gives an indication of relative abundance) and identify fish species. The results of the two-way crossed ANOVAs indicated that gabion habitats recruited greater numbers and more types of fish species and from more functional groups than the seawalls, especially omnivorous and carnivorous fish. Additionally, photoquadrats were used to quantify percentage cover, counts and to identify colonising taxa. The results of the two-way crossed ANOVAs indicated that gabions hosted greater numbers of species resulting in a higher overall diversity and abundance of colonising organisms than seawalls. By contrast, the seawalls supported more types of functional groups of colonising organisms than gabions, largely due to abundances of different algal species. The results from the crossed PERMANOVAs indicated that the composition of fish and colonising organisms were vastly different from one another, and that each habitat was supporting very different functional groups. Results indicate that whilst both gabions and seawalls contain several alien species, that the ratio of native to alien species is higher in gabion habitats. Additionally, this research observed that gabion structures hosted four species listed on the IUCN Red List of Threatened Species. This study has highlighted that the use of gabions (with their natural increased complexity) could be important to consider for the future of urban coastal development in harbours such as in Knysna Harbour. Ecological engineering projects using gabions have the potential to be used in South Africa in projects that aim at increasing biodiversity in urban coastal environments. As well as increasing the settlement and abundance of habitat-forming ecosystem engineers to ensure the long-term stability of these ecosystems. They can be used both in the development of new costal development projects as well as in an ad-hoc fashion where they can be interspersed on seawalls in harbours. Additionally, gabions have the potential to be used in projects that target species of conservation concern such as the endangered Knysna Seahorse (Hippocampus capensis). It is, however, important to monitor the invasion by non-native species in future ecological engineering projects in South Africa as well as their potential for creating ecological traps (a situation in which an organism may be convinced to settle in a low-quality habitat) for certain species. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-04
Natural Language Processing with machine learning for anomaly detection on system call logs
- Authors: Goosen, Christo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424699 , vital:72176
- Description: Host intrusion detection systems and machine learning have been studied for many years especially on datasets like KDD99. Current research and systems are focused on low training and processing complex problems such as system call returns, which lack the system call arguments and potential traces of exploits run against a system. With respect to malware and vulnerabilities, signatures are relied upon, and the potential for natural language processing of the resulting logs and system call traces needs further experimentation. This research looks at unstructured raw system call traces from x86_64 bit GNU Linux operating systems with natural language processing and supervised and unsupervised machine learning techniques to identify current and unseen threats. The research explores whether these tools are within the skill set of information security professionals, or require data science professionals. The research makes use of an academic and modern system call dataset from Leipzig University and applies two machine learning models based on decision trees. Random Forest as the supervised algorithm is compared to the unsupervised Isolation Forest algorithm for this research, with each experiment repeated after hyper-parameter tuning. The research finds conclusive evidence that the Isolation Forest Tree algorithm is effective, when paired with a Principal Component Analysis, in identifying anomalies in the modern Leipzig Intrusion Detection Data Set (LID-DS) dataset combined with samples of executed malware from the Virus Total Academic dataset. The base or default model parameters produce sub-optimal results, whereas using a hyper-parameter tuning technique increases the accuracy to within promising levels for anomaly and potential zero day detection. , Thesis (MSc) -- Faculty of Science, Computer Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Goosen, Christo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424699 , vital:72176
- Description: Host intrusion detection systems and machine learning have been studied for many years especially on datasets like KDD99. Current research and systems are focused on low training and processing complex problems such as system call returns, which lack the system call arguments and potential traces of exploits run against a system. With respect to malware and vulnerabilities, signatures are relied upon, and the potential for natural language processing of the resulting logs and system call traces needs further experimentation. This research looks at unstructured raw system call traces from x86_64 bit GNU Linux operating systems with natural language processing and supervised and unsupervised machine learning techniques to identify current and unseen threats. The research explores whether these tools are within the skill set of information security professionals, or require data science professionals. The research makes use of an academic and modern system call dataset from Leipzig University and applies two machine learning models based on decision trees. Random Forest as the supervised algorithm is compared to the unsupervised Isolation Forest algorithm for this research, with each experiment repeated after hyper-parameter tuning. The research finds conclusive evidence that the Isolation Forest Tree algorithm is effective, when paired with a Principal Component Analysis, in identifying anomalies in the modern Leipzig Intrusion Detection Data Set (LID-DS) dataset combined with samples of executed malware from the Virus Total Academic dataset. The base or default model parameters produce sub-optimal results, whereas using a hyper-parameter tuning technique increases the accuracy to within promising levels for anomaly and potential zero day detection. , Thesis (MSc) -- Faculty of Science, Computer Science, 2023
- Full Text:
- Date Issued: 2023-10-13
The mathematical and pedagogical content knowledge that Namibian senior primary teachers draw on to develop their learners’ computational estimation
- Authors: Shigwedha, Emilia Ndilimeke
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424108 , vital:72124
- Description: Computational estimation is important in the development of learners’ number sense. It is through the process of finding an approximate (but satisfactory) that learners can check the reasonableness of their answers to calculations, develop an understanding of place value and by implication the four number operations. It is the role of teachers to develop the computational estimation skills of learners. To do this, teachers need to have a sound knowledge of computational estimation, its value and how to teach it. This study thus seeks to explore and understand Namibian senior primary teachers’ mathematical and pedagogical content knowledge to develop their learners’ computation estimation knowledge. The research is guided by the following question: What mathematical and pedagogical content knowledge do senior primary mathematics teachers draw on to develop their learners’ computational estimation skills? The research is a qualitative interpretivist case study. Eight senior primary teachers of Mathematics from the Ohangwena region in Namibia participated in the study. Data was generated through questionnaires, a focus group interview and lesson observations. The Mathematics Knowledge for Teaching (Ball et al., 2008) and the Knowledge Quartet (Rowland, 2005) frameworks were used as both analytic and explanatory tools for the study. Key findings from the research are that teachers have knowledge of and use a variety of strategies for estimation, however, they only use the ‘rounding off’ strategy when teaching learners computational estimation. The teachers appear to teach computational estimation by first focusing on place value before moving on to ‘rounding off’ to the nearest 10s, 100s, 1000s and so forth. My research recommends that the National Institute of Educational Development together with the Ministry of Education, Art and Culture in Namibia, provide teachers with professional development opportunities on how to develop learners’ computational estimation. Such professional development will further develop teachers’ mathematical and pedagogical content knowledge. Furthermore, the Namibian syllabus should include a variety of strategies for computational estimation. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Shigwedha, Emilia Ndilimeke
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424108 , vital:72124
- Description: Computational estimation is important in the development of learners’ number sense. It is through the process of finding an approximate (but satisfactory) that learners can check the reasonableness of their answers to calculations, develop an understanding of place value and by implication the four number operations. It is the role of teachers to develop the computational estimation skills of learners. To do this, teachers need to have a sound knowledge of computational estimation, its value and how to teach it. This study thus seeks to explore and understand Namibian senior primary teachers’ mathematical and pedagogical content knowledge to develop their learners’ computation estimation knowledge. The research is guided by the following question: What mathematical and pedagogical content knowledge do senior primary mathematics teachers draw on to develop their learners’ computational estimation skills? The research is a qualitative interpretivist case study. Eight senior primary teachers of Mathematics from the Ohangwena region in Namibia participated in the study. Data was generated through questionnaires, a focus group interview and lesson observations. The Mathematics Knowledge for Teaching (Ball et al., 2008) and the Knowledge Quartet (Rowland, 2005) frameworks were used as both analytic and explanatory tools for the study. Key findings from the research are that teachers have knowledge of and use a variety of strategies for estimation, however, they only use the ‘rounding off’ strategy when teaching learners computational estimation. The teachers appear to teach computational estimation by first focusing on place value before moving on to ‘rounding off’ to the nearest 10s, 100s, 1000s and so forth. My research recommends that the National Institute of Educational Development together with the Ministry of Education, Art and Culture in Namibia, provide teachers with professional development opportunities on how to develop learners’ computational estimation. Such professional development will further develop teachers’ mathematical and pedagogical content knowledge. Furthermore, the Namibian syllabus should include a variety of strategies for computational estimation. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Technological pedagogical content knowledge development: investigating secondary school teachers' integration and use of technology during emergency remote teaching in Endola education circuit
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10
- Authors: Munyanyo, Johanna
- Date: 2023-10
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/423882 , vital:72101
- Description: The Covid-19 pandemic has created the largest disruption of education systems in human history. The closure of schools and other learning spaces has impacted billions of learners worldwide. The mitigative measures and many new standard operating procedures have brought restrictions and many challenges. The face-to-face traditional teaching method lost its value, and teaching shifted to distance through the integration of technologies. The integration of technologies necessitated the emergency remote teaching process, as it is one of the distance teaching modes that can make teaching possible even for less technologically privileged nations. Literature has shown that the integration and usage of technology during teaching support the development of technological pedagogical and content knowledge (TPACK) of teachers. This study, therefore, sought to investigate how the integration and use of technology during the emergency remote teaching of Covid-19 developed the secondary school teachers’ technological pedagogical and content knowledge. The study is underpinned by an interpretive paradigm, and a qualitative case study approach was employed. It was conducted in seven secondary schools in the Endola education circuit, Ohangwena region, with the purposeful participation of twenty-six secondary school teachers. Data was collected using semi-structured questionnaires and semi-structured interviews. The study was informed by Vygotsky’s (1978) sociocultural theory together with the TPACK framework of Thompson and Mishra (2007) as both theoretical and analytical frameworks. The study's results showed that teachers made use of existing technological resources to sustain their teaching efforts during ERT. They encountered various challenges, including a lack of technological expertise (knowledge) among both teachers and learners. The shift to virtual instruction during ERT supported teachers in developing proficient technological pedagogical content knowledge. This research concludes that schools possess the necessary technological infrastructure to enable teachers to incorporate technology into their teaching methods. Furthermore, it highlights that teachers generally hold favourable attitudes toward integrating technology into their instruction. Nevertheless, it recommends that there is a need for improving both in-service and pre-service teachers’ training and support for effectively teaching in online and blended learning environments. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10
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