This research introduces a high-performance electric taxiing system (ETS) as a modern solution to improve the on-ground operations of today’s aircraft, which are conventionally powered through the main engines. The presented ETS is propelled by electric motors, integrated into the main landing gear of a state-of-the-art midsize commercial aircraft, and powered by an additional not quantified electrical energy storage system. The proposed system can therefore operate autonomously from any aircraft-internal power source, i.e. Auxiliary Power Unit or equivalent. The main objective of this work is to assess the energy consumption of the introduced ETS while considering energy recuperation due to regenerative braking. The ETS powertrain is sized to match modern conventional taxi performances that were seen in 36 self-recorded takeoff- and landing taxi driving profiles. A custom ETS simulation model was developed and simulated across all available driving profiles to confirm the desired powertrain performance and to predict the system’s energy consumption. For the purpose of enhancing the validity of these energy consumption predictions, a suitable motor controller is then designed by the use of MATLAB Simulink. An easy-to-implement switch loss model was created to predict the ETS motor controller efficiency map. Finally, the former energy consumption predictions were revised for the implementation of the motor controller and an estimated traction motor efficiency map. The results exhibit that the revised ETS simulation model was capable of refining the energy consumption. It was found that the ETS will consume up to 9.89 kWh on average if the full potential of the traction motors energy recuperation capabilities are being used. The simulation outcomes further demonstrate that regenerative braking offers great potential in ETS applications since more than 14 % of required traction energy could be regenerated to yield the above mentioned average energy consumption. / Thesis / Master of Applied Science (MASc)

Text in English / An improved roads and public transport system also referred to in this research as road-transport, is strategic to economic growth in countries worldwide. This is why the improvements relating thereto have been prioritised by governments in developing economies such as South Africa. The problem that therefore informed the research in this study is that ever since the improvements on road-transport in South Africa, the implications thereof on the role of the Tshwane Metropolitan Police Department (TMPD) have not been studied, to understand the associated dynamics. The dynamics relate to how the road-transport improvements have swayed the role of law enforcement in the City of Tshwane. To unpack the dynamics, the study posed the question: What are the implications of the road-transport improvements on the role of the TMPD? In an attempt to answer this question, the study premised itself on exploring one primary aim, which is: to explore the implications of the road-transport improvements, on the role of the TMPD. To operationalise this aim, the study used three research objectives, which are: to describe the road-transport improvements In South Africa; to explain the role of the Tshwane Metropolitan Police Department; as well as to identify factors that hinders the effectiveness of the TMPD. The research used a qualitative approach wherein primary data was collected using interviews. The research showed that road-transport improvements in South Africa can be summarised into two categories. These are traffic improvements and improvements in public transport. The research also found that the role of the TMPD include traffic policing, by-law enforcement, crime prevention, crime Investigation and crowd management. Although the role of the TMPD is regulated properly, the study shows that this law enforcement agency was constrained by a number of challenges. The challenges include: lack of clarity in their crime prevention mandate; limited investigative powers; balancing their enforcement and crime prevention mandates; poor training in crowd management; staff shortages; resource problems; and administrative challenges. To deal with the problems thus requires strong management and leadership within the institution. / Police Practice / M. Tech. (Policing)

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This study aimed at examining the social and economic effects of the Rea Vaya Bus Rapid Transit system (BRT) on various stakeholders in Johannesburg. The objective of the study was to investigate the effect the Rea Vaya has had on users and non-users of the Rea Vaya system. The findings of this study suggest that the Rea Vaya is beneficial in that it provides an option in modes of transport for commuters, particularly for people who were historically disadvantaged and were not permitted to reside in the city during the apartheid era. BRT systems are designed to provide a safe, reliable and accessible public transport system. The Rea Vaya system is aimed at providing better public transport, reducing congestion, on public roads, improving the roads and creating jobs. The findings have shown that the Rea Vaya has not been successful in meeting all its aims. The Rea Vaya has not managed to provide an accessible transport system thus far. Traffic in the inner city has not been reduced as a modal shift has not yet occurred. Since the inception of the Rea Vaya system there has been resistance from the Taxi Industry. Despite negotiations and attempts made by the Municipality of the City of Johannesburg to include the Taxi Industry in the Rea Vaya system, by making them shareholders of the system, the findings presented affirms that there is still resentment and resistance from the Taxi Industry towards the Rea Vaya system. The loss of revenue since the introduction of the Rea Vaya has caused a challenge for Taxi owners. Not only is it alleged that the Rea Vaya has affected the Taxi Industry, but the Rea Vaya infrastructure has caused a number of problems for private car users in the City. Private car users are inconvenienced by the designated bus lanes and lack of road signage in the city. These conclusions affirm that the Rea Vaya is not beneficial to all stakeholders in the City of Johannesburg. The experiences and opinions of users and non-users suggest that the system has a number of deficiencies. However some users of the system have benefited socially and economically. For some of the users the Rea Vaya has created a few opportunities; however the poor customer service from bus drivers and station staff was seen as a setback. Transit Orientated development in Johannesburg has not yet taken off. The government’s attempts to create mixed land use through the implementation of corridors of freedom are in its infant stages. Businesses across the Rea Vaya station found the Rea Vaya to have both positive and negative effects on their businesses. Some businesses found that the development of stations have added aesthetic value, however due to the frequency of Rea Vaya buses at stations, commuters would not wait for long periods of time and this resulted in fewer customers for businesses across the Rea Vaya station. The Rea Vaya system has provided a safe and reliable transport system in Johannesburg. However, the system is in its infant stages and has a number of deficiencies as presented in the findings of this study. / Geography / M. Sc. (Geography)

This study aimed at examining the social and economic effects of the Rea Vaya Bus Rapid Transit system (BRT) on various stakeholders in Johannesburg. The objective of the study was to investigate the effect the Rea Vaya has had on users and non-users of the Rea Vaya system. The findings of this study suggest that the Rea Vaya is beneficial in that it provides an option in modes of transport for commuters, particularly for people who were historically disadvantaged and were not permitted to reside in the city during the apartheid era. BRT systems are designed to provide a safe, reliable and accessible public transport system. The Rea Vaya system is aimed at providing better public transport, reducing congestion, on public roads, improving the roads and creating jobs. The findings have shown that the Rea Vaya has not been successful in meeting all its aims. The Rea Vaya has not managed to provide an accessible transport system thus far. Traffic in the inner city has not been reduced as a modal shift has not yet occurred. Since the inception of the Rea Vaya system there has been resistance from the Taxi Industry. Despite negotiations and attempts made by the Municipality of the City of Johannesburg to include the Taxi Industry in the Rea Vaya system, by making them shareholders of the system, the findings presented affirms that there is still resentment and resistance from the Taxi Industry towards the Rea Vaya system. The loss of revenue since the introduction of the Rea Vaya has caused a challenge for Taxi owners. Not only is it alleged that the Rea Vaya has affected the Taxi Industry, but the Rea Vaya infrastructure has caused a number of problems for private car users in the City. Private car users are inconvenienced by the designated bus lanes and lack of road signage in the city. These conclusions affirm that the Rea Vaya is not beneficial to all stakeholders in the City of Johannesburg. The experiences and opinions of users and non-users suggest that the system has a number of deficiencies. However some users of the system have benefited socially and economically. For some of the users the Rea Vaya has created a few opportunities; however the poor customer service from bus drivers and station staff was seen as a setback. Transit Orientated development in Johannesburg has not yet taken off. The government’s attempts to create mixed land use through the implementation of corridors of freedom are in its infant stages. Businesses across the Rea Vaya station found the Rea Vaya to have both positive and negative effects on their businesses. Some businesses found that the development of stations have added aesthetic value, however due to the frequency of Rea Vaya buses at stations, commuters would not wait for long periods of time and this resulted in fewer customers for businesses across the Rea Vaya station. The Rea Vaya system has provided a safe and reliable transport system in Johannesburg. However, the system is in its infant stages and has a number of deficiencies as presented in the findings of this study. / Geography / M. Sc. (Geography)