Thèses sur le sujet « Virtual rider »

The Optimal Maneuver Method is a package for optimal control problem simulations based on the mathematical formulation of a vehicle model capable of getting the dynamics of the system and on the concept of ideal rider. The work presented in this thesis covers different purposes: the development of the current methodology applied to motorcycles in order to improve matching between experimental evidence results and lap-time simulations, second to formulate different single, two, four-wheeled vehicle models for different application cases. Third to create flexible libraries to manage components that are communal between the different models and require a particular formulation. Fourth to apply the Optimal Maneuver Method for studying the optimality of some specialized driving techniques that are nowadays under investigation, as aggressive maneuvers outside the linear behavior of tires, which knowledge are at the base of modern active chassis control systems.
Il Metodo della Manovra Ottima è un pacchetto software per simulazioni basate su problemi di controllo ottimo. Esso consiste nella formulazione matematica di un modello di veicolo capace di cogliere la dinamica del sistema a cui è associato e si basa sul concetto di pilota ideale. Il lavoro presentato in questa tesi copre diversi aspetti: lo sviluppo della già esistente metodologia applicata in campo motociclistico al fine di migliorare la corrispondenza tra prove sperimentali e risultati delle simulazioni, secondo la formulazione di diversi modelli di veicolo ad una, due e quattro ruote per diverse applicazioni. Terzo lo sviluppo di un pacchetto di librerie in grado di gestire alcuni componenti comuni a più modelli di veicolo che richiedono una particolare formulazione. Quarto l’applicazione del Metodo della Manovra Ottima per lo studio dell’ottimalità di certe tecniche di guida adottate da piloti professionisti che sono al momento oggetto di studio, come manovre aggressive oltre il comportamento lineare degli pneumatici, la cui comprensione è alla base dei moderni sistemi di controllo attivo del veicolo.

A number of diseases can be prevented through active lifestyles. Yet, despite technological and non-technological interventions, many people do not engage in exercise. Immersive virtual reality (iVR) offer the opportunity for highly engaging and entertaining experiences. Their designs affects how people are motivated (or not) to engage and exercise. To maximise the benefits of these technologies a model of motivation that can help designers is needed. There is need to investigate psychological constructs of wellbeing: how do users engage with wellbeing technology’s designs? What motivates or demotivates them? And how can constructs borrowed from psychology aid better technological designs? This thesis introduces a framework for comparing designs in VR exergames and use technologies as instruments to study motivation. An iVR exergaming platform – VR-Rides – was developed to explore designs for wellbeing over an iterative design, development and evaluation process. The thesis addresses challenges by understanding users’ perceptions, evaluating iVR designs based on psychological constructs and informing future designs based on findings to promote wellbeing goals. Furthermore, various designs, game narratives and mechanics were developed to engage players in activities that purportedly lead to wellbeing. The research applied a quantitative research methodology, facilitated across five studies conducted in diverse social settings. Four studies particularly explored VR-Rides’ designs for participants’ engagement and motivation in an exergaming setup. In the fifth study we tested the feasibility of the VR-Rides platform to assess memory for age-related cognitive decline. The findings show psychological constructs have a central role in understanding users’ enjoyment and motivation with wellbeing platform, highlight motivating factors, and bridge the gap between technology designs and wellbeing constructs.

Pre-Trip Inspection of the truck and trailer is one of the components of the current Commercial Driver's License (CDL) test. This part of the CDL test checks the ability of the student to identify the important parts of the commercial vehicle and their potential defects. The Virtual Check Ride System (VCRS), a computer-based application, is an assessment and feedback tool that mirrors the inspection component of the actual CDL. The VCRS has provided an after action review (AAR) via a feedback session that helps in identifying and correcting drivers' skill in inspecting parts and for overall safety. The purpose of this research is to determine the effectiveness of the VCRS in truck driving training programs. An experimental study was conducted with truck driving students at Mid Florida Tech, located in Orlando, Florida. The students were divided into control and experimental groups. Students in the both groups received regular training provided by Mid Florida Tech. The experimental group received additional training by making use of the VCRS. A total of three paper-based tests were given to all subjects during first three weeks; one test at the end of a week. Both groups were given the same paper-based tests. A two-way analysis of variance was conducted to evaluate the effect of the VCRS in the experimental group. This analysis found a significant difference between control and experimental groups. This effect showed that the students in the experimental group increased their performance by using VCRS. Moreover, there was a main effect in the scores of each week. However, there was not an interaction between the two factors. Follow up Post Hoc tests were conducted to evaluate the pair-wise differences among the means of the test week factors using a Tukey HSD test. These Post Hoc comparisons indicated that the mean score for the third week's test scores were significantly better than the first week's test score in the experimental group. It was concluded that the VCRS facilitated learning for the experimental group and that learning also occurred for both groups as a result of repeated testing.
Ph.D.
Other
Other
Modeling and Simulation PhD

Water is the source of life. Leonardo da Vinci, constructor of the drainage system of a swamp area north of Rome, said that “water is the blood of the soil”. Without water there is not fertile soil and without any of them there is no harvest. Sustainable Agriculture Management is all about how to develop and improve the use of different resources to make agriculture more sustainable. This study is about how to apply this concept into the study area. The Balkhash Lake is among the biggest lakes on earth, but due to unreasonable water utilization, the lake is facing the same fate as the Aral Sea. The lake belongs to the Ili Balkhash Basin IBB that is shared by two countries; Kazakhstan and China. Most of the water (around 80%), that feed the lake, come with the Ili River that is born on the Chinese side. Most of the water is used for agriculture purposes. Now the Chinese Government want to increase the irrigated area and develop more projects that require more water. If this is done without any improvement in the agriculture management, the IBB is under threat. The irrigation systems in the study area are very precarious. The farmers are isolated with almost no possibility to participate in the development process. The government is not interested in any research in water issues and the information that can be found about water consumption and cultivated area are proven to be far from reality. A difficult situation facing the above mention problematic. The agriculture area can grow but the water management in the Upper Ili Basin needs to be reviewed and improved. Just by doing small changes like changing rice cultivation for a crop with a higher water productivity the amount of water that can be saved is considerable. Or by importing virtual water from a region with a higher water productivity. But first a general recognition from the Chinese side about water shortage is necessary. The Ili Balkhash Basin can be sustainable if it is treated as a whole. The boundaries of the system need to be set around the whole basin. A partial view of the basin can be dangerous and jeopardize the subsistence of the natural environment of the area. When the carrying capacity of the basin is measured, the only way to grow is under this threshold. In this case, by improving water productivity with better agriculture management.

Satellite derived data has become an essential input in hydraulic modelling. Digital ElevationModels (DEMs) derived from different sources through remote sensing techniques have become a powerful tool for poorly gauged regions. This paper analyses the capabilities of DEMS derived from Shuttle Radar Topography Mission (SRTM) and a Light Detection and Ranging (LiDAR) and compares their accuracy against each other in a 1D hydraulic model. The study tests two different methods for inferring the river bathymetry under the water surface level for the SRTM derived DEM in order to enhance its performance, the study further analyze the reliability of remotely sensed altimetry data derived from different satellite missions (TOPEX and ENVISAT) and its suitability to complement spaceborne topographic data in hydraulic modelling.

This dissertation encompasses two studies: one developing virtual field trips for mobile devices for an innovative approach to lower-division geoscience education, and the other examining the role of rock strength in river erosion and landscape evolution. The education study involves the development of three virtual field trip modules (Geologic Time, Geologic Structures, and Hydrologic Processes, all free on iTunes and Google Play) that lead students down a virtual Colorado River through Grand Canyon by physically moving around their campus quad, football field or other location, using their GPS-equipped smart phone or tablet. As students reach each location in the scaled down and geo-referenced virtual Grand Canyon, an informative video appears with a themed geological question and an interactive touchscreen activity. The effectiveness of these three modules in terms of student engagement and learning was tested at five U.S. Colleges with a range of missions and student demographics. Results show that the virtual field trip modules are effective at increasing student interest across races and genders in the geosciences, do not detract from student learning, and have the potential to increase content comprehension. The second study is the examination of the relation between rock strength and topography in the Colorado Plateau. This work contributes empirical data to the age-old debate over the mechanisms and patterns of stream erosion through statistical relations between rock strength and stream power, river steepness, and valley width along the Green-Colorado River system. Estimates of an “effective” tensile strength were calculated for units too incompetent to test directly, such as the shales prevalent in the region. Results indicate bedrock strength is a first-order control on river erosion in this landscape, as suggested by John Wesley Powell in 1896: “where the rocks are firm and stable, corrasion [sic] of the stream is slow; where the rocks are soft, corrasion [sic] is more rapid,” which is intuitive yet frequently overlooked.

Estimating the bed material transport in large gravel-bed rivers represents a challenging task. Among the alternatives to achieve estimates of such key process, the virtual velocity approach represents one of the most promising possibilities. The research aims at improving the virtual velocity approach and at evaluating the reliability of its transport estimates using an independent and robust procedure as the morphological method applied at the same dam-regulated study sector of the Parma River (Italy). After field and remote sensing data collection, we performed the coarse sediment transport calculations using the two selected approaches and compared the estimates obtained at the same river cross-sections. Since the two methods provided remarkably similar transport results over the period April 2016 - April 2017, the virtual velocity approach can be considered as a viable tool for achieving reliable bed material load estimates in large gravel-bed rivers.
La stima del trasporto del materiale grossolano costituente il letto dei corsi d’acqua ghiaiosi di grandi dimensioni rappresenta un’attività complessa. Fra le diverse possibilità per conseguire tale obiettivo il metodo della “velocità virtuale” costituisce una delle opzioni più promettenti. Il presente lavoro di ricerca mira al miglioramento di tale approccio e alla valutazione dell’affidabilità delle stime da esso fornite utilizzando quale termine di confronto i risultati forniti dall'applicazione di un robusto “metodo morfologico” applicando entrambi le metodologie al medesimo settore studio posto a valle di una diga che regola il flusso del Torrente Parma (Italia). A seguito della raccolta di dati in campo e attraverso tecniche di telerilevamento è stato eseguito il calcolo del trasporto solido grossolano mediante le due metodologie selezionate e sono state confrontate le stime ottenute in corrispondenza di quattro sezioni-studio. I risultati ottenuti risultano essere significativamente simili per il periodo Aprile 2016 - Aprile 2017, permettendo di concludere che il metodo della velocità virtuale rappresenta un’alternativa affidabile per stimare il trasporto solido grossolano in corsi d’acqua ghiaiosi di grandi dimensioni.

Operating hydropower reservoirs with small storage capacity is a challenging task due to the fact that in a watershed system there usually exist multiple stakeholders with different and conflicting preferences and values. Consequently the process of planning for reservoir operation must be carried out with consideration of several, usually competing, objectives. This process becomes even more challenging during a high inflow or flooding event for three main reasons. First, the objective of minimizing adverse consequences of such an event is added to the set of objectives that the operator must deal with. Second, inflow forecast uncertainty-driven risks are highly intensified due to the high sensitivity of the outcomes to inflow forecasts. And third, the available time for making a decision is very short while comprehensive analysis is a necessity in order to make an informed decision regarding the best operational alternative. Under these circumstances, the best approach to confront this challenge could be developing a Risk-Informed Decision Making (RIDM) framework that provides operation planning engineers with a solid and pre-designed guideline to deal with the task of identifying the best operational alternative in an efficient and timely manner. The current study is an attempt to apply the virtual structure of a RIDM framework for the Cheakamus River system in British Columbia. The framework is a coherent assembly of a number of methods and tools we have either developed or utilized from the existing widely used methods and techniques in practice. The product of our work is an example of the necessary tools that need to be used to develop recommendations for operating Daisy Lake reservoir during a high inflow event in a manner that all the operational objectives are served in the best possible way. This is done while taking into account making trade-offs among competing objectives. We illustrate the practical applicability and merits of the framework through applying it to a historical high inflow period in October 2003. The outcome is near real-time decisions with less dependency on only planners’ judgement and more dependency on thorough and systematic analysis with consideration of human judgement and possible risk tolerances.

The Colossi of Memnon are a prominent feature of the constructed landscape at ancient Thebes (modern day Luxor, Egypt). They were built on the West Bank during the later years of Amenhotep III reign and they stood in front of his royal cult temple, Mansion of Millions of Years, known today colloquially as Kôm el-Hetan. There is no consensus on the purpose of the statues and it is plausible that they were meant to represent multiple things. However, what all the theories surrounding their purpose have in common is that they are all reliant on the visibility of the statues. The Theban Harbours and Waterscapes Survey led by Angus Graham (Uppsala University) discovered that the royal cult temple and colossi statues was built on top of an elevated area of what is believed to be have been a pre-existing wadi fan (Toonen et al.2018; 2019). To the east of the temple, a minor channel of the Nile river was also discovered. The aim of this thesis was to analyse the visibility and visual experience of the Colossi of Memnon during the 18thDynasty. By analysing the boreholes from the Theban Harbours and Waterscapes Survey, I have (re)constructed the geological features of the surrounding landscape in a game engine (Unity). The visual analysis was done by a combined GIS spatial analysis and a VR based phenomenological approach. I concluded that the levees of the minor channel of the Nile were not elevated high enough to create any substantial blocking of the view from the floodplain or from inside of the channel during the low season. It was only when you got up close to the levees and kneeled on the ground that you would lose sight of parts of the colossi. As the surface level of the Nile rose during its annual cyclethe, it would be easier to observe the statues from any part of the minor channel. As for the visual experience of observing the Colossi of Memnon from different parts of the model, the experience only changed slightly from viewing the statues from the view of the floodplain or the channel. What changed the experience drastically was if you approached the statues from the front of from the side. As you approached the statues from the front you had the statues standing symmetrically in front of the temple and they are in turn facing you. Being in front of the Colossi statues creates a feeling of being part of the statues’ experience. Not only where the humans meant to see the statues, I believe that the statues were meant to see us. This as the most ideal location to observe and visually experience the statues, is where we are in the view of both the Colossi of Memnon. The experience of the statues fades as you approach them from their side where you become the observer rather than the observed. The visual experience from the side also results in that you do not get to fully take part in the experience that both statues provide. This is because one of them becomes slightly blocked by the other.

På grund av pandemi utfördes opponering på distans över Zoom

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais
INCT-EIE - Instituto Nacional de Ciência e Tecnologia De Estruturas Inteligentes em Engenharia
Os sistemas de suspensão automotivos são projetados para permitir que o condutor tenha controle total do veículo. Esses sistemas devem garantir com eficiência o isolamento de vibração para o interior do automóvel, a aderência entre os pneus e o solo e a estabilidade do veículo durante a execução de manobras que envolvam mudança de direção. Neste trabalho foi conduzida uma investigação experimental sobre o comportamento dinâmico de um veículo de passeio da categoria hatch compacto premium. Manobras específicas de handling e ride foram consideradas nos testes físicos, a fim de avaliar a resposta do sistema de direção e o conforto dos passageiros. Handling se refere ao modo como o veículo se comporta durante a execução de manobras de mudança de direção e ride se relaciona à forma como a suspensão do veículo responde as irregularidades de pista durante o ato de dirigir. O trabalho de pesquisa contempla a definição de uma metodologia aplicada ao desenvolvimento de um modelo completo de veículo, através do método de multicorpos. Na modelagem matemática, a maioria dos componentes de suspensão foram considerados como rígidos, visto que as deformações elásticas são suficientemente pequenas, podendo assim serem consideradas desprezíveis. No entanto, é considerada a presença de alguns elementos flexíveis, em particular a barra estabilizadora e o eixo de torção, que se revelam essenciais na tentativa de construção de um modelo capaz de reproduzir adequadamente os efeitos não lineares. Nesse sentido, a barra estabilizadora foi representada como um corpo flexível, com o objetivo de incluir a sua não linearidade geométrica no modelo. Já a modelagem do eixo de torção foi baseada em uma técnica de cossimulação que utiliza um solver de multicorpos e um solver externo de elementos finitos para análise não linear. Simulações do comportamento dinâmico foram realizadas a fim de verificar a abrangência do modelo e correlação com os dados experimentais. O estudo de ride é apresentado enfatizando a métrica necessária para quantificar o conforto do veículo, de acordo com a norma ISO 2631-1. Os dados coletados experimentalmente foram processados no domínio da frequência e do tempo utilizando o software LMS Test.Lab. O processo de construção e simulação do modelo virtual foi realizado utilizando o software LMS Virtual.Lab Motion para a simulação de multicorpos e o LMS Samcef MECANO para a simulação de elementos finitos.
Automotive suspension systems are designed to allow the driver full control of the vehicle. These systems must efficiently ensure the vibration insulation of the car cabin, the tire grip on the road and the vehicle’s stability during turning maneuvers. In this study, an experimental investigation of the dynamic behavior of a subcompact premium car was conducted. Typical ride and handling maneuvers were considered in the physical tests in order to evaluate the steering response and passengers comfort. Vehicle handling refers to the way that the vehicle performs during turning maneuvers, and ride to how the vehicle suspension responds to the track irregularities during the act of driving. This work describes the methodology used for the development of a full vehicle model through the multibody method. In mathematical modeling, the majority of vehicle suspension components were included in the model as rigid bodies, due to the fact the elastic deformations are sufficiently small and hence negligible. However, there is the presence of some flexible elements, in particular the stabilizer bar and the twist beam, which are essential in the attempt to build a model capable of properly reproducing the nonlinear effects. Accordingly, the stabilizer bar was represented as a flexible body, in order to include geometric non-linearity into the model. The modeling of the twist beam was based on a co-simulation technique that uses a multibody solver and an external nonlinear solver for finite element method analysis. Dynamic behavior simulations were performed to verify the scope of the model and correlated with the experimental data. The ride comfort study was carried out emphasizing the required metric to quantify the vehicle comfort according to ISO 2631-1. The data collected were processed and analyzed in frequency and time domain using the LMS Test.Lab software. The building and simulation of the virtual model was performed using the LMS Virtual.Lab Motion software for the multibody simulation and LMS Samcef MECANO software for the finite element simulation.
Dissertação (Mestrado)

碩士
國立臺北科技大學
互動設計系碩士班（碩士在職專班）
104
The technology of virtual reality has been evolving greatly in recent years, applied to all kinds of fields. Virtual reality differs from the traditional media, for it is beyond the limitation of screen playing. Immersion into virtual reality is a first-person perspective experience, allowing users to experience a wider range of feelings and emotions, thefore, be fully absorbed in the multi-seonsry experiences. This research adopted a user experience design and analyzed the multi-sensory experience on Gogoro virtual ride received by all participants. Datas are collected by using a research method- in depth interview. Result shows that multi-sensory virtual ride model is able to enhance the positive impression of Gogoro given to the participants. Also, the project designers will have a better understanding on product attributes and therefore increase the customer satisfaction. We provide insight on how virtual reality can be applied to wider application of multi-sensory experience, which hopefully can be the future reference for developers and researchers.

碩士
國立花蓮教育大學
科技藝術研究所
96
For the recent years, the government has been investing in National Digital Archives Program constructively, it makes Digital Content become rising and flourishing, and inject a new tidal current of medium into Taiwan’s culture. Additionally, scholars and experts have brought up an idea that the initial decade would be an era of Virtual Reality in the Twenty-first century, and Virtual Reality has some qualities like immersing, imagination, and interaction; in consequence, the manifestation of integrating Digital Content with Virtual Reality will be an innovative technique. Through putting in use of this fresh-technique, users can experience different notions and feelings with regard to the information that tangible objects convey. This research has been applied to interpret the substantiality of the renowned painting “Along the River During the Ching-Ming Festival” in a originative way by skills of Virtual Reality, with collecting the reference, and the related studies researched by experts. Furthermore, this research is estimated for the content of system in terms and ways of Usability Engineering, which can enhance the objectivity and follow-up progression. This research has been introduced the art of Virtual Reality into “Along the River During the Ching-Ming Festival,” which is taken the famous parts like “The Bridge of Rainbow”, “Scenery”, and “the Torii In front Of Tai-Jih Pond” as the scenes. By means of operating virtual characters, switching viewpoints, auxiliary documents, and routes of video cameras, along with Conversational System, users can play the roles of general viewers, who would be able to wander in the virtual scenes by acting as virtual characters, and gain dissimilar awareness and cognition as regards the Traditional Art Collection. Basing on the principle of user-centered design, carry the result of this research out with Usability Test, and administer Expert-Focused method twice, along with once User-Focused. It has been linked up Coach method, Interviewing as well as Questionnaires in the course of assessment, and the assessing items in questionnaires have been brought into practice for Satisfaction Questionnaire with Likert Scale, then get the result into operation for Significance Test, the twice Expert-Focused among which would be separately assessed the situations before improving the system and after it. Turns out, as the items of this research, “Sense of Design” and “Functionality” have achieved the Significance Level, which shows that the tacks advanced before improvement assist the consequence after improvement with upgrading the usability of entirety interface. However, it has been respectively proceeded assessment by users with different backgrounds of art and technology in User-Focused. As a result, compassing the Significance Level in “Sense of Design” and “Functionality” reveals that users with diverse backgrounds have cognitive diversity of interface operation.

碩士
國立臺北教育大學
社會科教育學系碩士班
97
With the rise of living standards, people became more aware of ecological and environmental protection, and rethought the usage of the rivers. Thus, how to give back what has been lost, by river restoration, sustainable utilization of the ecosystems and space, as well as leisure management, has become salient to urban and country development. This research focused on the River Dahan in Dahan region. The analyses of the river in terms of geographical, hydrogeological and anthropological conditions as well as the theories of river restoration had been collected with field research to ascertain substantial components of river restoration. The river restoration project of the river Dahan in Dahan region proposed in this research was based on the literature findings. This project was demonstrated through 3D virtual reality model, which was generated by using Remote Sensing technology and Digital Terrain Model (DTM). The environment in this 3D terrain model was enhanced with 3D graphic programs, and demonstrated the features after the amendment of the riverside. With the demonstration in 3D virtual reality environment, this project ccould be adequately comprehended and discussed by the government as well as the public. This project benefited designers, administrators, and users in terms of instant communication, analysis, evaluation, and amendment. It also provided the tool, which was most economical, well-interactive, genuinely-simulated, user-involved and highly-efficient, for river restoration.

博士
國立彰化師範大學
電機工程學系
104
An image based water information measurement of river flow is studied in this dissertation. For long-term investigation, this study had proposed some methods for solving water flow velocity estimation in the recorded images without artificial seeding particles, multiple weather and flow conditions. An adaptive LS-PIV with DADR approach was proposed that was utilized to dynamically determine the better detection region for measurement of river surface velocity under multiple conditions. The adaptable IA determining algorithm was applied to automatically correct the IA size and overcome the lower SNR and higher errors produced by the measurement with the conventional fixed IA size under variable environments. In this study, the MVWLP method was proposed which can be applied to any river environments without staff ruler. This approach mainly applies the color space adjustable technique to reduce noises and uses the adaptive edge detection with morphological processes to extract the current water line. Then, it sets some virtual probes on the discovered water line to detect its height and compare with the pre-set reference based water line to obtain the current water level. The velocity area method was applied to estimate flow discharge in this study. The depth-averaged velocity of sampling verticals in the designated transection can be obtained by the LS-PIV surface velocity with the velocity correction coefficient. Finally, this study takes experiments in three sites which have different flow conditions to verify the LS-PIV measurement. The MVWLP water level measurement is also validated by the graduated rod or the depth gauge. Based on the experimental results, the proposed approaches are accurate, robust and adaptable enough to overcome multiple flow and weather conditions. Furthermore, this water flow information is implemented on the Internet Website and smart phone APP system to improve the information readability and mobile efficiency. This mobile system is a useful interface of river information for the water resource management and hazard rescue.

To aid the tuning and optimization of the truck seat design to specific trucks and road profiles during the design phase, this study presents the development and validation of a virtual seat model. This study also assess the utility of the model for whole body vibrations evaluation. The virtual dynamic seat model was developed in MSC. ADAMS/VIEW. The critical elements like the suspension mechanism, the airspring, dampers and seat cushion were modeled using tested data. To validate the performance of the virtual model, prototype tests were performed using the MTS 6-axis simulator. The modeling process was targeted to achieve a good correlation between measured and simulated data around the 5Hz frequency zone. For validation of the complete system, three test sessions were carried out. The first session collected the vibration data for validating the simulator model and the suitability of the data processing methods used. The second, collected the force-displacement data for the airspring modeling. The third test session involved the testing of the entire seat and simulator system. Validation of the virtual model is based on comparison of the tested and simulated data. The results are presented for steady-state sinusoidal inputs in the range 1,5 and 8Hz and also random inputs of 0.5-20Hz. Analysis of the whole body vibration evaluation parameters like peaks, crest factor, rms, rmq (root-mean-quad), VDV (vibration dose value) and eVDV (estimated VDV) is also included. The results obtained in this study indicate that the virtual model is able to reproduce the vibration behavior of the prototype fairly accurately in the 5Hz target region. With higher frequencies, the results shown that the model is not able to capture the nonlinearities observed in the prototype’s response. The model, however, did exhibit its ability to predict the behavioral trends in the seat response which can prove to be very beneficial for seat design. Based on the level of agreement between the tested and simulated values for the whole body vibration parameters, the use of this model for whole body vibration evaluations looks promising.

Southern Africa generally has an arid climate and many hydrologists are predicting an increase in water scarcity over time. This research seeks to understand the implications of this in socio-political terms. The study is cross-disciplinary, examining how policy interventions can be used to solve the problem caused by the interaction between hydrology and demography. The conclusion is that water scarcity is not the actual problem, but is perceived as the problem by policy-makers. Instead, water scarcity is the manifestation of the problem, with root causes being a combination of climate change, population growth and misallocation of water within the economy due to a desire for national self-sufficiency in agriculture. The solution lies in the trade of products with a high water content, also known as 'virtual water'. Research on this specific issue is called for by the White Paper on Water Policy for South Africa.
Political Sciences
M.A. (International Politics)