Notre thèse porte sur l’analyse du gouvernement de la circulation urbaine pour la période allant des années 1910 aux années 1960. Elle s’appuie sur un travail de terrain constitué principalement d’une monographie du cas lyonnais que nous avons enrichie à partir d’autres exemples urbains (Marseille, Lille, Bordeaux, Nice, Saint-Étienne, Villeurbanne). Nos sources sont principalement constituées de fonds d’archives municipaux, mais également nationaux (des ministères concernés), internationaux (SdN, ONU) et d’autres documents de première main (archives privées et consulaires, périodiques). Notre travail se structure autour de deux grandes questions concernant l’analyse de l’action publique urbaine : la construction et l’identification d’un problème public ; la régulation d’un secteur d’intervention publique. Ces deux niveaux d’analyse sont appréhendés au niveau des scènes locales, nationales ou transnationales, de discussion des problèmes automobiles. En questionnant la structuration des pouvoirs urbains, on peut mettre en évidence l’existence d’un gouvernement par commissions, rassemblant des institutions et des acteurs divers et éclatés, et concourant à une co-production de l’expertise et de l’action publique en matière de circulation urbaine. Cette étude sur un temps long permet de montrer que, dans ce secteur, des formes de « gouvernance » articulant intérêts privés et enjeux publics ont émergé progressivement et se sont structurés au moment même où l’automobile devenait un enjeu urbain et un problème public central pour les villes du XX° siècle. Le gouvernement de la circulation urbaine constitue un excellent observatoire de la dynamique de constitution des pouvoirs urbains autour de dispositifs d’action publique pluralistes et largement participatifs qui renvoient au final à des débats situés au cœur même de la science politique contemporaine (pluralisme, gouvernance, réseaux, interfaces public/privé, démocratie participative...). / Our thesis investigates the expansion of urban traffic from the early 1910s to the late 1960s. Initially built around the case of Lyon, one of the major French cities nowadays, the study also refers to the situation of others places -namely Marseille, Lille, Bordeaux, Nice, Saint-Etienne and Villeurbanne- in order to further underline the specificities -or lack of- of the city of Lyon. Not only does it rely on municipal archives, but also on national and international archives and periodicals issued by either public authorities or private bodies. Two main themes of interest structure the dissertation: the social construction of a public problem and the related regulation of public intervention. We investigate them through the study of local, as well as national and international, debates over the place of the car in the city. By focusing more precisely on urban governance, we shed light on a « government by commissions » that creates spaces for the co-production of expertise and public intervention by various public and private actors otherwise isolated. Most interestingly, we found that both the topic –how to accommodate the car in the city- and its means of governance –which implication should follow from private as well as public actors- structured progressively through the twentieth century. The study of transportation thus works as a great lens to observe and analyze the reshaping of urban government around the themes of empowerment and governance, at the very heart of political science and public policy analysis.

University of Macau / Faculty of Science and Technology / Department of Electromechanical Engineering

This thesis comprises a programme of work investigating the use of active human computer models and the effects of forthcoming automotive safety features on vehicle occupants; more specifically, their unbelted kinematics and sustained injuries. Since Hybrid III anthropometric crash test dummies are unable to replicate human occupant kinematics under severe braking, the thesis highlighted the need to research the most appropriate occupant computer model to simulate active safety scenarios. The first stage of the work focussed on occupant kinematics and developed unique human occupant reflex response target curves describing the head and torso relative angle change as a function of time, based on human volunteers’ low deceleration sled tests. These biomechanics curves were, subsequently, used to validate an active human model, asserting its torso response, while confirming that further development in its neck response was necessary. The sled test computer validation proved that only an active human model was suitable to model a pre-braking phase. The second stage of the work combined the occupant’s kinematics of the pre-braking phase, followed by a subsequent frontal crash into a rigid barrier inducing an airbag deployment. The results suggested that, in a 1g frontal deceleration pre-braking phase, the kinematics of an unbelted occupant within the vehicle compartment was complex and in some cases extreme. With the parameters adopted within this unique study, it was observed that occupant motion and position relative to the airbag system varied depending on awareness level, seat friction, braking duration and posture. Additionally, it was observed that a driver holding the steering wheel with one hand could be out of the airbag deployment reach due to extreme Out-Of-Position (OOP). Results also concluded that the dynamic OOP scenario was intricate and would yield to higher occupant injuries. Future studies, into brake dive, seat geometry, seat stiffness and cabin packaging, are recommended to capture the vehicle configuration providing the highest dynamic OOP safety risk. Finally, the investigations conducted, as part of this doctoral programme, led to the provision of new knowledge in the validation of active human models, a unique demonstration of the importance using human computer models, rather than crash test dummies, as well as the potential for the evaluation of future restraint systems in dynamics unbelted OOP, considering various posture scenarios.

M.Ing. / Vehicles used in military, agricultural, forestry, or construction applications often encounter different road surfaces during a single journey. In order to optimise the mobility of these vehicles, different tyre pressures are required for different types of terrain (sand, mud, cross country, tar road, etc.). An in-motion tyre pressure control system will enable the vehicle's operator to change the tyre pressures without leaving the vehicle. Such a system will not only allow optimum surface contact between the tyres and the terrain - thus improving vehicletraction, but it can also increase the lifespan of the tyres and reduce fuel consumption. The key design criteria for such a system are: quick reaction times, an effective operator interface, and reliability. In case of system failure, the operator must be able to override the control, and the tyres should be inflated to a pre-set default pressure. When the fault had been corrected, the system can be restarted from within the cabin, to inflate or deflate the tyres as required. The focus of this thesis is on the design criteria of a tyre pressure control system, receiving inputs from the driver and from onboard vehicle sensors; and then adjusting individual tyre pressures if necessary, while the vehicle is on the move. Based on the inputs to the control system, the optimum setting for the tyre pressure is determined from a look-up table stored in memory of an onboard computer. This table contains the pressure-speed and pressure-axle load relationship. A unique relation is programmed into the microprocessor for each different vehicle. To install a tyre pressure control system on a vehicle, a computer program is used to control the following hardware which are necessary to inflate or deflate tyres: An air compressor and storage tank. Pneumatic valve. Rotating seal. Pressure and speed sensing elements. Electronic control unit. An experimental set-up was built, from various components or sub-systems, which were integrated systematically until the system was working as a unit. The functionality of the system was tested, and although the results obtained do not yet justify the commercial manufacturing of such systems, it is trusted that this research has contributed towards the increased emphasis that is placed upon vehicle safety and comfort systems.

M.Com. / The purchasing and maintenance cost of a company car has increased dramatically due to factors such as worldwide high inflation rates and drastic increases in fuel costs. This increase in operating costs is magnified according to fleet size and has a direct bearing Upon company expenses and product costs ...

Mobility has become a substantial part in our society. Since we spend a lot of our available time on the road, we expect the automotive environment to provide similar comfort levels than residential buildings. Within this context, this research thesis especially focuses on automotive thermal comfort control. The automotive cabin is a very special environment, which is characterized by extreme inhomogeneity and overall transient behavior. Thermal comfort is a very vague and a very subjective term, which depends on physiological and psychological variables. Theories for thermal comfort in transient environments have not been fully established yet and researchers are still busy with its investigation. At present, automotive industry relies on extensive thermal comfort models, manikins and powerful simulation tools to assess and control thermal comfort. This thesis studies the application of artificial intelligence and proposes a blackbox approach which aims for extracting thermal comfort knowledge directly from human's interaction with the HVAC controls. This methodology avoids the use of human physiological and psychological thermal comfort models and does not require any a-priori knowledge. A novel comfort acquisition tool has been developed and has been integrated into a research vehicle in order to gather the required data for system learning. Data has been collected during spring, autumn and summer conditions in Southern Africa. Methods of data mining have been applied and an intelligent implementation using artificial neural networks has been proposed. The achieved results are promising and allow for about 87 perecent correct classification. It is concluded that methods of artificial intelligence perform well and are far superior compared to conventional approaches. These methods can be used as a powerful tool for the development process of vehicle air-conditioning controls and have great potential for time and cost reduction.

The following work describes all knowledge required in the creation of new automotive optical Photogrammetrical adaptors, which allow the user thereof to measure a fully assembled vehicle in its natural position, i.e. on its wheels for the PQ25 platform at Volkswagen of South Africa. The system is the only method available to the manufacturing plant to measure a fully assembled vehicle in this manner. The FlexMess system allows for a quick portable measurement of a vehicle at all stages of Vehicle manufacturing, aligned via the Volkswagen RPS standards. In the first part of the work, the problem of establishing a system capable of measuring the PQ25 platform is achieved by redesigning the PQ24 platform (previous generation Polo) to the new PQ25 vehicle platform. Once the system was redesigned a prototype adaptor system was created. In the second part of the work, the redesigned adaptor system is checked for its accuracy and repeatability. In a statistical analysis of the adaptors ability to measure the reference points needed for alignment of a vehicle, the system is compared to a CMM and verified that the limits fall within the limits of the original FlexMesśs certified accuracy limits. The last part of the work looks at addressing some of the problems of the FlexMess system by creating concepts for an ideal future FlexMess adaptor system.

Visual intrusions are a consequence of the presence of motor vehicles in urban residential areas. Measuring the community's level of annoyance to the negative images of vehicles, determining the capacity of the visual environment to accommodate vehicles, and introducing standards of visual quality for the appearance of a neighbourhood are tasks in which urban planners should become involved. In the study of visual vehicular disturbances, literature was reviewed and a case study was undertaken. A questionnaire was organized and administered in three Vancouver residential areas so as to obtain attitudinal and factual information. Attitudinal responses were elicited in regard to the resident's actual environment and to certain standard environments portrayed in photographs. A data analysis involved correlations between variables which were hypothesized to be associated. The main conclusions from the research were, first that residents, when asked directly, do appear to be annoyed by the unattractiveness of vehicles in the residential environment. However, residents do not appear to be sensitive to the importance of visual intrusions as a problem when compared to other adverse vehicular effects. Second, the correlation coefficients were either not statistically significant or not high enough to be conclusive in support of the hypothesized associations between levels of annoyance and (l.) socio-economic status, (2) motor vehicle activity, and (3) effectiveness of visual screening structures. Third, and finally, the visual-capacity of the residential environment to accommodate motor vehicles was perceived to be higher by communities of lower socio-economic status. Because of the uncertain future use of motor vehicles, particularly in light of fuel shortages and rising insurance costs for vehicles, and the high public expenditures required for physical alterations to reorganize vehicular movements and parking facilities, "short-term", "wait and see", "bandaid" type approaches are recommended to mitigate the problem of visual intrusions. A planning alternative whereby accessibility is maintained while measures are -taken to enhance the visual quality leads to an implementing proposal such as visual screening structures. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

In this study, experimental tests and Computational Fluid Dynamics are used to investigate the aerodynamic performance of two types of track-based racing cars. After the literature study, where automotive aerodynamics is discussed in very general terms, the air flow beneath a Formula One Grand Prix Racing Car is investigated. This is achieved by fitting the under-tray of a 30% scale model of the Parmalat Forti Ford FGO 1-95 with surface-static pressure ports and testing the model in a rolling-road wind tunnel. By varying a number of model parameters, it is found that the wheels significantly alter the pressure distribution under the floor of the racing car at positions away from the centre-line. It is shown that the front or rear wheel sets are independently sufficient to induce the flow changes. The addition of the other set then only produces milder and more local changes. The numerical part of the floor investigation is aimed at reproducing the centre-line flow pattern by solving the full Reynolds-Average Navier-Stokes equations over a two-dimensional curvilinear grid of the isolated floor. Two algorithms, Roe's flux-difference splitting method and the commercial package, STAR-CD which employs the SIMPLE algorithm and a two-equation turbulence model, are used to solve the governing equations. It is found that although the correct trends are observed when two different ride heights are simulated, absolute correlation is inadequate despite the use of experimentally-controlled boundary conditions. The simulations are however used to demonstrate the saturation in downforce with increasing vehicle speed. In order to improve numerical accuracy, a second study was launched where the effect of including the centre-line profile of the complete vehicle is investigated. To reduce the amount of detail a 1/12th scale model of a generic BMW Touring Car is used. Experimental data in the form of centre-line surface-static pressure coefficients are used for numerical correlation. The data is obtained by testing the three-dimensional model in a wind tunnel fitted with a stationary-road raised-platform floor. To establish continuity, the experimental data is used to show the similarities between the pressure distribution on the centre line of the open-wheel and the closed-wheel racing car. The effect of a rear-mounted aerodynamic device on the downforce is also discussed. The numerical investigation using the SIMPLE algorithm of STAR-CD and three high Reynolds-Number turbulence models, is based on the centre-line profile of the experimental model. It is seen that although qualitative correlation exists in areas around the car, quantitative agreement is less positive. Discrepancies are found to be most significant under the floor. It is shown that the influence of the three dimensional flow field on the experimental results are unlikely to cause satisfactory correlation. It is suggested that, in order to improve correlation, a new investigation is launched aimed at refining the numerical model. An outline for the new study is presented and includes simulations indicating the dependence of the computational solution on the density of the grid and on the user-definable turbulence parameters. / Dissertation (M Eng (Mechanical Engineering))--University of Pretoria, 1999. / Mechanical and Aeronautical Engineering / unrestricted

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