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An accurate, high-speed, fully differential difference amplifier for current sensing utilizing the chopper approach was implemented in a 0.18 μm complementary metal-oxide-semiconductor (CMOS) technology. Unlike state-of-the-art solutions, we use a higher chopping frequency in the MHz range due to the bandwidth requirements of the introduced circuits for the latter application, namely, low-side phase-current measurement in motor control circuits. Except the low-pass filter (LPF) effect of the output stage, no additional LPF was integrated in hardware at the output of the circuits. We show that on the other hand a digital LPF, which can be integrated in the field-programmable gate-array (FPGA) logic or microcontroller used for the motor control, offers a higher flexibility in terms of filter design. Weak input signals of only few mV can be reconstructed with a high accuracy. This is demonstrated for a 500 kHz rectangular signal and a chopping frequency of 20 MHz. Note that an input-signal frequency of several hundreds of kHz with harmonics in the MHz region is very challenging for chopper amplifiers. Still, a significant decrease of the input-referred noise is demonstrated, especially cancelling out the 1/f-noise achieving a remaining noise floor of approximately 8.5 nV/√Hz. Overall, the input-referred noise level can be pushed far below 50 μV (root mean square). Moreover, using a quite relaxed second-order Butterworth filter with a 3 dB corner frequency of 1 MHz, input-referred noise levels of 10 μV (root mean square) can be easily achieved at the costs of reduced bandwidth. The lowest achieved input offset is 50 μV. The gain is adjusted by resistive feedback and is approximately 40 dB. Hence, the amplifier is suitable for current sensing in motor control circuits, and a significant reduction of the shunt resistance typically used for this purpose will be possible.

Virtual Reality is rapidly growing in popularity. This new medium offers manypossibilities for those who wish to explore what the technology provides in the 3Denvironment. However, the design principles that have been used for decades revolvearound 2D surfaces and applying them in the 3D space can cause severalincompatibility issues that diminishes the user experience.This study aimed to help highlight what aspects of virtual reality need to be improvedcompared to non-virtual reality platforms to enhance the user experience. To do this,VRChat, a virtual reality platform was chosen, which can be used by both VR, and nonVR headset users alike. By comparing these two user bases it could help highlight thepros and cons of the current system and help give guidelines on how to create futureVR platforms. During the test period, 58 people participated who did specific tasks onthe platform and filled out the quantitative data gathering survey, based on the UserExperience Questionnaire (UEQ) test.After comparing the two user bases, the result shows that there is no significantdifference between using VRChat either way allowing both user bases to enjoy theplatform equally. However, because of these results, the work failed to highlight whataspects of a VR platform need to be changed to fit the needs of VR headset users. Itimplies the need for further research and experimenting with the medium. In the future,further research, testing and experimentation are needed to improve the current designmodels and make the systems more pleasant for VR headset users.

Accounting transactions are becoming more complex, and more extensive accounting guidance is provided on a continuous basis in the accounting standards. In addition, accounting guidance changes often and additional guidance is added to the standards regularly. In view of this immense amount of accounting knowledge that an accountant can be expected to have, exacerbated by often multifaceted structures in accounting problems, it can be challenging and onerous to solve certain accounting problems. The premise of this study is that accounting problems can also be solved in a less complex manner with reference to the foundational accounting concepts included in the Conceptual Framework for Financial Reporting (CF). The solution to the accounting problem using the CF should result in a similar answer had the detailed, complex accounting guidance been consulted. This is based on the understanding that the detailed guidance is consistent with the CF and that the CF is not underdeveloped. In the experience of the author of this dissertation, however, the CF is rarely used to consider the accounting treatment of specific transactions and the first point of reference is usually the detailed, specific guidance. In order to impart a practice of incorporating the CF in problem-solving, the study in this dissertation is underpinned by educational philosophies rooted mainly in constructivism, and specifically in Ausubel’s subsumption theory. Applied to accounting education, this theory suggests a frameworkbased approach whereby educators first instil a detailed knowledge of the CF in an Accounting course and thereafter present details of specific accounting transactions by building and crossreferencing to the foundational concepts in the CF. In addition, the paradigm in Accounting courses should also incorporate problems and experiments through which students can construct their own knowledge, rather than being passive recipients of an educator’s teaching style. Recent literature on framework-based teaching suggests that such an approach is beneficial as it enhances lifelong learning. This study reported on a framework-based approach incorporated in an Accounting course and aimed to determine students’ ability to solve complex accounting problems by referring only to the CF, as well as to determine the factors that could influence their ability to solve the problems and the preferred problem-solving approach of students in facing future accounting problems. In order to address the broad aim of this study, it was divided into two sections, each to identify and analyse a different aspect of accounting problem-solving that incorporated the CF. The study in this dissertation focused mainly on an interpretive research paradigm. The first project had the primary objective of determining whether students have the ability to solve complex accounting problems by using only the CF and determining which factors could influence their ability. This was established by analysing the content and results of an assignment administered to third-year Accounting students at a South African university in which students were required to solve problems using only the CF. The second project had the objective of determining the preferred future approach students will take in solving accounting problems after they have been exposed to a framework-based assignment. This was established through qualitative measures and augmented by a questionnaire to analyse the students’ perceptions. The contributions of this dissertation are manifold and include, but are not limited to, the realisation that a conceptual approach to accounting education is beneficial in Accounting courses. The results in this study indicate that the ability of students to solve complex accounting problems by referring only to the CF may depend on the complexity of the scenario and the students’ familiarity with the problem. In addition, after being exposed to a framework-based assignment, students may tend to prefer a mixed approach in solving accounting problems, which entails a combination of the concepts in the CF and specific accounting guidance governing a particular transaction. The author also believes that this study makes a practical contribution by providing an actual framework-based assignment which can be used or adapted by other Accounting educators to use in similar courses, or to help them develop similar assignments or case studies or to replicate the study. From an educational perspective, it is recommended that Accounting educators incorporate an emphasis on the CF in their teaching approach. As students are exposed to opportunities to exercise their judgement using the concepts included in the CF, they will gain experience in this and be able to exercise better judgement in future. Each time a student is exposed to a problem requiring to be solved using the CF, or is required to make necessary judgements with regard to the CF, it will lead to the creation of new knowledge which the student can constantly link and cross-reference to existing knowledge and experiences. It also appears that, when students are exposed to problem-solving using the CF, it may lead to accountants adopting a more balanced approach by considering more CF constructs in solving future accounting problems. Although the study in this dissertation was conducted at only one university, its implications are by no means limited to this institution. Extrapolation of results cannot be attempted due to the nature of the research design, but the results in this study are valuable and enhance accounting education literature in better understanding students’ problem-solving abilities and their preferred problemsolving approach. The research is therefore valuable to any Accounting educator, as well as the institutional bodies guiding accounting education and its syllabi. It is hoped also that some of the findings will inspire other educational institutions to promote a framework-based approach in an innovative manner. / MCom (Accountancy), North-West University, Potchefstroom Campus, 2015

Professional development (PD) of teachers is part of the Department of Basic Education‘s (DBE) initiative to encourage school communities to use of information and communication technology (ICT) to improve the quality of Mathematics teaching and learning. The South African Council of Educators stipulates that PD programmes should align with system-wide needs, strengthen learning area content and outcomes, and promote system transformation. Imbedded in this system-wide criterion is The White Paper on e-Education to employ a fully ICT integrated system at all levels of education: management, teaching and learning, and administration by 2013. Mathematics teachers require PD that develops their technological pedagogical and content knowledge (TPACK) and their social professional identity (SPI). The PD of Mathematics teachers for ICT integration can assist the DBE to achieve the aims of The White Paper on e-Education and bridge the technology gap between South Africa and international education systems. Open distance learning (ODL) could be a viable method to deliver PD to Mathematics teachers to address their zone of proximal development, develop their TPACK, and establish and maintain their SPI. This study made use of a fully mixed sequential equal status multi-mode research design and methodologies to develop guidelines for the PD of Mathematics teachers in the pedagogical use of ICT in ODL. The qualitative phase (Phase I) was rooted in the interpretivist paradigm. Through an adjustable exploration of a systematic literature review, the researcher identified 23 core documents, analysed them with Atlas.ti™, and conceptualised four themes according to Engeström‘s third generation activity theory (AT). Phase II (radical exploration phase) of the research design was rooted in the radical structuralist paradigm. In the context of transformation, it developed, validated, and standardised a research instrument for the measurement of Mathematics teachers‘ PD requirements. The instrument was distributed to 300 senior phase (grades 7-9) Mathematics teachers in eight education management district centres of the WCED. The analyses of the quantitative data conceptualised a fifth activity system. The five activity systems from the adjustable and radical exploration phases were symbiotic, and co-dependent. Expansive learning was used for boundary crossing and network building during six phases of this study. The findings from the six phases of the expansive learning cycle indicated that PD of Mathematics teachers in ODL for Phase III implementation of the e-Education policy should be a joint initiative. Fundamentally ICT integration and implementation should start with Department of Basic Education (DBE) initiatives. The DBE and Provincial Departments of Education (PDEs) should conduct a needs analysis of ICT implementation, evaluate previous ICT PD programmes, plan ICT PD strategies aligned with the ICT development plan, as well as with the requirements of the Mathematics teachers. The DBE and PDE should invest in the provision of ICT equipment, afford human capital, reinstate the laptop initiative for teachers, and supply schools with networked-computer facilities to explore online platforms for PD. Mathematics teachers should assess their professional knowledge to construct new philosophies, create a subject network group, and interact as participants and members within their social environments. The standardised instrument could be used to determine and compare the PD of Mathematics teachers in other provinces and contexts. / PhD (Training and development), North-West University, Potchefstroom Campus, 2014

Accounting transactions are becoming more complex, and more extensive accounting guidance is provided on a continuous basis in the accounting standards. In addition, accounting guidance changes often and additional guidance is added to the standards regularly. In view of this immense amount of accounting knowledge that an accountant can be expected to have, exacerbated by often multifaceted structures in accounting problems, it can be challenging and onerous to solve certain accounting problems. The premise of this study is that accounting problems can also be solved in a less complex manner with reference to the foundational accounting concepts included in the Conceptual Framework for Financial Reporting (CF). The solution to the accounting problem using the CF should result in a similar answer had the detailed, complex accounting guidance been consulted. This is based on the understanding that the detailed guidance is consistent with the CF and that the CF is not underdeveloped. In the experience of the author of this dissertation, however, the CF is rarely used to consider the accounting treatment of specific transactions and the first point of reference is usually the detailed, specific guidance. In order to impart a practice of incorporating the CF in problem-solving, the study in this dissertation is underpinned by educational philosophies rooted mainly in constructivism, and specifically in Ausubel’s subsumption theory. Applied to accounting education, this theory suggests a frameworkbased approach whereby educators first instil a detailed knowledge of the CF in an Accounting course and thereafter present details of specific accounting transactions by building and crossreferencing to the foundational concepts in the CF. In addition, the paradigm in Accounting courses should also incorporate problems and experiments through which students can construct their own knowledge, rather than being passive recipients of an educator’s teaching style. Recent literature on framework-based teaching suggests that such an approach is beneficial as it enhances lifelong learning. This study reported on a framework-based approach incorporated in an Accounting course and aimed to determine students’ ability to solve complex accounting problems by referring only to the CF, as well as to determine the factors that could influence their ability to solve the problems and the preferred problem-solving approach of students in facing future accounting problems. In order to address the broad aim of this study, it was divided into two sections, each to identify and analyse a different aspect of accounting problem-solving that incorporated the CF. The study in this dissertation focused mainly on an interpretive research paradigm. The first project had the primary objective of determining whether students have the ability to solve complex accounting problems by using only the CF and determining which factors could influence their ability. This was established by analysing the content and results of an assignment administered to third-year Accounting students at a South African university in which students were required to solve problems using only the CF. The second project had the objective of determining the preferred future approach students will take in solving accounting problems after they have been exposed to a framework-based assignment. This was established through qualitative measures and augmented by a questionnaire to analyse the students’ perceptions. The contributions of this dissertation are manifold and include, but are not limited to, the realisation that a conceptual approach to accounting education is beneficial in Accounting courses. The results in this study indicate that the ability of students to solve complex accounting problems by referring only to the CF may depend on the complexity of the scenario and the students’ familiarity with the problem. In addition, after being exposed to a framework-based assignment, students may tend to prefer a mixed approach in solving accounting problems, which entails a combination of the concepts in the CF and specific accounting guidance governing a particular transaction. The author also believes that this study makes a practical contribution by providing an actual framework-based assignment which can be used or adapted by other Accounting educators to use in similar courses, or to help them develop similar assignments or case studies or to replicate the study. From an educational perspective, it is recommended that Accounting educators incorporate an emphasis on the CF in their teaching approach. As students are exposed to opportunities to exercise their judgement using the concepts included in the CF, they will gain experience in this and be able to exercise better judgement in future. Each time a student is exposed to a problem requiring to be solved using the CF, or is required to make necessary judgements with regard to the CF, it will lead to the creation of new knowledge which the student can constantly link and cross-reference to existing knowledge and experiences. It also appears that, when students are exposed to problem-solving using the CF, it may lead to accountants adopting a more balanced approach by considering more CF constructs in solving future accounting problems. Although the study in this dissertation was conducted at only one university, its implications are by no means limited to this institution. Extrapolation of results cannot be attempted due to the nature of the research design, but the results in this study are valuable and enhance accounting education literature in better understanding students’ problem-solving abilities and their preferred problemsolving approach. The research is therefore valuable to any Accounting educator, as well as the institutional bodies guiding accounting education and its syllabi. It is hoped also that some of the findings will inspire other educational institutions to promote a framework-based approach in an innovative manner. / MCom (Accountancy), North-West University, Potchefstroom Campus, 2015

Professional development (PD) of teachers is part of the Department of Basic Education‘s (DBE) initiative to encourage school communities to use of information and communication technology (ICT) to improve the quality of Mathematics teaching and learning. The South African Council of Educators stipulates that PD programmes should align with system-wide needs, strengthen learning area content and outcomes, and promote system transformation. Imbedded in this system-wide criterion is The White Paper on e-Education to employ a fully ICT integrated system at all levels of education: management, teaching and learning, and administration by 2013. Mathematics teachers require PD that develops their technological pedagogical and content knowledge (TPACK) and their social professional identity (SPI). The PD of Mathematics teachers for ICT integration can assist the DBE to achieve the aims of The White Paper on e-Education and bridge the technology gap between South Africa and international education systems. Open distance learning (ODL) could be a viable method to deliver PD to Mathematics teachers to address their zone of proximal development, develop their TPACK, and establish and maintain their SPI. This study made use of a fully mixed sequential equal status multi-mode research design and methodologies to develop guidelines for the PD of Mathematics teachers in the pedagogical use of ICT in ODL. The qualitative phase (Phase I) was rooted in the interpretivist paradigm. Through an adjustable exploration of a systematic literature review, the researcher identified 23 core documents, analysed them with Atlas.ti™, and conceptualised four themes according to Engeström‘s third generation activity theory (AT). Phase II (radical exploration phase) of the research design was rooted in the radical structuralist paradigm. In the context of transformation, it developed, validated, and standardised a research instrument for the measurement of Mathematics teachers‘ PD requirements. The instrument was distributed to 300 senior phase (grades 7-9) Mathematics teachers in eight education management district centres of the WCED. The analyses of the quantitative data conceptualised a fifth activity system. The five activity systems from the adjustable and radical exploration phases were symbiotic, and co-dependent. Expansive learning was used for boundary crossing and network building during six phases of this study. The findings from the six phases of the expansive learning cycle indicated that PD of Mathematics teachers in ODL for Phase III implementation of the e-Education policy should be a joint initiative. Fundamentally ICT integration and implementation should start with Department of Basic Education (DBE) initiatives. The DBE and Provincial Departments of Education (PDEs) should conduct a needs analysis of ICT implementation, evaluate previous ICT PD programmes, plan ICT PD strategies aligned with the ICT development plan, as well as with the requirements of the Mathematics teachers. The DBE and PDE should invest in the provision of ICT equipment, afford human capital, reinstate the laptop initiative for teachers, and supply schools with networked-computer facilities to explore online platforms for PD. Mathematics teachers should assess their professional knowledge to construct new philosophies, create a subject network group, and interact as participants and members within their social environments. The standardised instrument could be used to determine and compare the PD of Mathematics teachers in other provinces and contexts. / PhD (Training and development), North-West University, Potchefstroom Campus, 2014

Given satellite images with accompanying pixel classifications and elevation data, we propose different solutions to object detection. The first method uses hierarchical clustering for segmentation and then employs different methods of classification. One of these classification methods used domain knowledge to classify objects while the other used Support Vector Machines. Additionally, a combination of three Support Vector Machines were used in a hierarchical structure which out-performed the regular Support Vector Machine method in most of the evaluation metrics. The second approach is more conventional with different types of Convolutional Neural Networks. A segmentation network was used as well as a few detection networks and different fusions between these. The Convolutional Neural Network approach proved to be the better of the two in terms of precision and recall but the clustering approach was not far behind. This work was done using a relatively small amount of data which potentially could have impacted the results of the Machine Learning models in a negative way.

Ce travail de recherche a été principalement motivé par les avantages importants apportés par la technologie UTBB FDSOI aux applications analogiques et RF de faible puissance. L'objectif principal est d'étudier le comportement dynamique du transistor MOSFET du type UTBB FDSOI et de proposer des modèles prédictifs et des recommandations pour la conception de circuits intégrés RF, en mettant un accent particulier sur le régime d'inversion modérée. Après une brève analyse des progrès réalisés au niveau des architectures du transistor MOSFET, un état de l’art de la modélisation du transistor MOSFET UTBB FDSOI est établi. Les principaux effets physiques impliqués dans le transistor à double grille avec une épaisseur du film de 7 nm sont passés en revue, en particulier l’impact de la grille arrière, à l’aide de mesures et de simulations TCAD. La caractéristique gm/ID en basse fréquence et la caractéristique ym/ID proposée pour la haute fréquence sont étudiées et utilisées dans une conception analogique efficace. Enfin, le modèle NQS haute fréquence proposé reproduit les mesures dans toutes les conditions de polarisation y compris l’inversion modérée jusqu’à 110 GHz. / This research work has been motivated primarily by the significant advantages brought about by the UTBB FDSOI technology to the Low power Analog and RF applications. The main goal is to study the dynamic behavior of the UTBB FDSOI MOSFET in light of the recent technology advances and to propose predictive models and useful recommendations for RF IC design with particular emphasis on Moderate Inversion regime. After a brief review of progress in MOSFET architectures introduced in the semiconductor industry, a state-of-the-art UTBB FDSOI MOSFET modeling status is compiled. The main physical effects involved in the double gate transistor with a 7 nm thick film are reviewed, particularly the back gate impact, using measurements and TCAD. For better insight into the Weak Inversion and Moderate Inversion operations, both the low frequency gm/ID FoM and the proposed high frequency ym/ID FoM are studied and also used in an efficient first-cut analog design. Finally, a high frequency NQS model is developed and compared to DC and S-parameters measurements. The results show excellent agreement across all modes of operation including very low bias conditions and up to 110 GHz.