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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

"It is no accident that this is called an accident"- vehicular negligence : a socio-legal study of crime, law, and public safety

Badh, Varinder 16 April 2014 (has links)
Criminality takes many forms; a homicide may be defined as criminal activity, as would identity theft--both acts are criminal, yet the responses garnered are quite different. What makes the response for these two acts different? Perhaps societal reaction and tolerance towards these behaviours. Why is it that popular socio-legal discourse takes the position that societal reaction is the result of the information it receives? The focus of my research was to determine whether language affects perception and whether this impacts police and judicial practice. The focus was on the discourse of legal and popular language used to describe motor vehicle incidents that encompass a criminal component of injury and or fatality. I examined the impact of terminology on public and legal perception, as well as societal reactions and tolerance, which were the underlying issues of examination. However, in order to understand reaction and tolerance, I found it important to study the factors that contributed towards public and legal perception. The method of analysis was to examine the terminology used to depict and deliver the news of such incidents. For the purposes of this investigation vehicular negligence is defined as any act or behaviour that contravenes the British Columbia Motor Vehicle Act or is a Criminal Code of Canada offence related to the operation of a motor vehicle. Under the law, a negligent act does not require mens rea, which literally means to have a guilty mind. Therefore, in order to be considered guilty, a person does not necessarily need to have the mental culpability of forecasting or have the intention of inflicting harm. I restricted my area of focus to the region of British Columbia for two primary reasons. First, British Columbia has a higher than average injury and fatality rate resulting from motor vehicle incidents when compared to other provinces in Canada. Second, the area of focus was limited to this province as the result of my direct personal experiences in this provincial context. The parameters of my case study, as indicated above, included only those incidents of vehicular negligence that resulted in bodily injury and or fatality. The form of negligence assessed was not restricted to a specific type of act; rather it included any act that would be considered negligent behaviour on the roads, including but not limited to, driving in excess of the posted speed limit, impaired driving, carelessness, hit and runs, and so forth. My interest was to examine the ways in which these acts are perceived and addressed in public (media) and legal (court) discourse. Focusing on five randomly selected cases involving vehicular negligence, thematic analysis of face-to-face interviews, discourse analysis, and autoethnography were the primary methodologies used for the investigation. At present, there is no shortage of literature examining the cause and effect of specific behaviours in relation to motor vehicle incidents. The shortcoming, however, is that the focus of the literature is primarily centred on the consequences of drunk driving as it relates to the mismanagement of vehicles and the subsequent legal and civil litigations. Some of the literature also addresses social and health costs related to the severity of vehicle negligent incidents. However, there is a dearth of research examining the role of public and legal perceptions as they pertain to vehicular negligence and the impacts on the way in which vehicular negligent incidents are addressed within the courts. The results of this research indicated that terminology does in fact have an impact on perception, and thus negligent incidents on the roads should be referred using terms that are accurate descriptions. Terms such as accidents construe an incorrect understanding of the implications from these types of acts that are a leading health and safety epidemic globally.
32

Video Streaming and Multimedia Broadcasting Over Vehicular Ad Hoc Networks

Naeimipoor, Farahnaz 30 January 2013 (has links)
Video dissemination capabilities are crucial for the deployment of many services over VANETs. These services range from enhancing safety via the dissemination of video from the scene of an accident, to advertisement of local services or businesses. This work considers the infrastructure-less scenario of VANETs and dissemination of video content over this network environment, which is extremely challenging mainly due to its dynamic topology and stringent requirements for video streaming. This study discusses issues and challenges that need to be tackled for disseminating high-quality video over VANETs. Furthermore it surveys and analyzes the suitability of different existing solutions aimed towards effective and efficient techniques for video dissemination in vehicular networks. As a result, a set of the most promising techniques are selected, described in detail and evaluated based on standard terms in quality of service. This thesis also discusses efficiency and suitability of these techniques for video dissemination and compares their performance over the same network condition. In addition, a detailed study on the effect of network coding on video dissemination protocols has been conducted to guide how to employ this technique properly for video streaming over VANETs. From this study, a summary of the observations was obtained and used to design a new hybrid solution by deploying robust and efficient techniques in number of existing protocols in an optimal manner. The proposed hybrid video dissemination protocol outperforms other protocols in term of delivery ratio and complies with other quality-of-service requirements for video broadcasting over vehicular environments.
33

Video Streaming in Vehicular Ad Hoc Networks: Challenges, Protocols and The Use of Redundancy

Rezende, Cristiano 30 April 2014 (has links)
Vehicular Ad Hoc Networks (VANETs) are no longer a futuristic promise but rather an attainable technology. Vehicles are already equipped with a variety of computational devices that control or assist drivers in many tasks such as localization, safely breaking, parking and passengers entertainment. The majority of services envisioned for VANETs either require the provision of multimedia support or have it as an extremely beneficial additional feature. In particular, video streaming capabilities over VANETs are crucial to the development of interesting and valuable services. However,VANETs’ highly dynamic topology poses as a demanding challenge to the fulfillment of video streaming’s stringent requirements. The main goal on this thesis is the development of feasible solutions that support the streaming of video content over VANETs. Initially, the main issues of VANETs are explained through both a discussion of its characteristics and the results of some preliminary conclusions. Based on this understanding of VANETs’ peculiarities, three distinguishing solutions are designed REACT-DIS, REDEC and VIRTUS; the two first for video dissemination and the later for video unicast. These solutions offer a great advancement towards the provision of video streaming capabilities but packet loss is still an issue at high data rates. In order to improve the delivery ratios reached by the previous solutions, redundancy is used as an error correction mechanism. The use of redundancy is ideal for VANETs in handling packet loss as they do not require any interaction between source and receivers nodes. Sophisticated coding techniques were used for an efficient use of the increase on entropy of the information sent by the source node. It was also evaluated the selective use of redundancy solely on packets carrying the crucial information of I-frames. Although this selective approach obtained lower overall delivery ratios than when redundancy is used for all packets, the video quality obtained similar improvements under a much lower cost. The evaluation on the use of redundancy has considered the impact on the rate by which unique video content is received at end-users which is fundamental to understand the resolution of videos that can be displayed. This thesis provides several contributions as it advances the knowledge in the peculiarities of VANETs, solutions for video streaming over VANETs and the use of redundancy as an error correction mechanism for video streaming over VANETs.
34

Performance enhancement in VANET with admission control and contention window adjustment

Tiwari, Vivek 10 September 2012 (has links)
Vehicular Ad Hoc Networks (VANET), a derivative of mobile networks, has the capability to increase the safety, e ciency and comfort of transportation systems, and provide users on-the-road Internet connectivity. Because of its impetus and signi cance in practical scenarios, it becomes a sought after topic in both industry and academia. In this thesis, we focus on the vehicle-to-infrastructure (V2I) drive-thru Internet services in a highway scenario. The road side unit (RSU) along a highway can provide network services for vehicles within the coverage. To enhance the network performance, we propose two strategies. First, to ensure a high network throughput, the RSU uses an admission control strategy to limit the competition among vehicles, and avoid the waste of channel time to the low-data-rate users. Second, based on the vehicle density, we also propose a contention window (CW) adjustment strategy which can reduce the collision probability when the network is congested, and reduce the idle time otherwise. Extensive simulations using network simulator (NS-2) are given, which demonstrate the e ectiveness of the proposed solutions. / Graduate
35

Estudio Comparativo de Actividad Vehicular y Modelación de Emisiones para Santiago y Buenos Aires

Henríquez Salazar, Pilar Ivonne January 2008 (has links)
Hoy en día, los centros urbanos se caracterizan por tener gran cantidad de vehículos, los cuales tienen un alto grado de responsabilidad en el deterioro de la calidad del aire presente en muchas de estas ciudades. Reducir la contaminación, producida por las emisiones vehiculares de una región, es un proceso complejo que requiere conocer en detalle y cuantitativamente la actividad vehicular asociada a la localidad en cuestión. El presente trabajo de memoria tiene como objetivo determinar experimentalmente los patrones dinámicos de la actividad vehicular en Santiago y Buenos Aires, mediante una metodología común, y estimar las emisiones vehiculares asociadas a través de un modelo internacional (IVE, International Vehicle Emissions). En ambas localidades se aplico la misma metodología para determinar la actividad vehicular característica de cada ciudad. Se realizaron campanas de medición en terreno en tres sectores socioeconómicos distintos: alto ingreso, bajo ingreso y comercial. Posteriormente, la información generada en las campanas experimentales fue revisada y procesada, para luego ingresarla al modelo IVE y estimar las emisiones diarias y anuales de CO2, CO, NOx, MP, COV y gases toxicos. Los resultados de este trabajo son, por una parte, determinar la actividad vehicular de Santiago y Buenos Aires, la que contempla composición de flujo vehicular, distribución tecnológica de la flota, distribución de partidas en frío y caracterización de patrones de conducción. Por otra parte, los resultados de emisiones asociadas a dicha actividad vehicular, para Santiago y Buenos Aires, son: 31,8 y 21,7 kTon/día de CO2; 2,9 y 3,6 kTon/día de CO; 0,2 y 0,3 kTon/día de NOx; 10,4 y 10,9 Ton/día de MP; y 0,2 y 0,3 kTon/día de COV, respectivamente. La conclusión general de esta memoria es que se obtuvieron los inventarios de emisión para fuentes móviles en ruta correspondientes al año 2007, para Santiago y Buenos Aires, luego de determinar experimentalmente la actividad vehicular propia de cada localidad. La ciudad de Santiago resulto tener una flota ´ vehicular mas numerosa y con mayor actividad que Buenos Aires, pero con menor nivel de emisiones, principalmente debido al mejor estándar tecnológico que posee el parque vehicular de Santiago, en relación a Buenos Aires.
36

Approaches to the Design and Implementation of Roadside Units in Vehicular Networks

Reis, Andre Braga 01 December 2017 (has links)
The traffic safety and efficiency applications made possible by vehicular communications have the potential to improve the lives of millions of people who, every day, use automobiles as their primary means of transportation. To be well connected and fully functional, these networks of cars require a minimum number of active nodes, which often may not happen due to a lack of radio-equipped vehicles on the road. These same networks can also be overwhelmed with traffic and signaling in the presence of too many cars, requiring careful coordination between all nodes to ensure proper operation. One way to overcome both these problems is to supplement vehicle-to-vehicle (V2V) communications with vehicle-to-infrastructure (V2I) systems by deploying Roadside Units (RSUs) along the road to support the network of moving cars. RSUs are infrastructure nodes that can supplement sparse networks in low-density scenarios, and help coordinate and move data in denser networks. RSUs have an associated cost, however, and so their numbers need to be minimized while still maintaining a significant improvement to the vehicular network. he work presented in this thesis quantities the benefits of Roadside Unit deployments and proposes innovative approaches that can reduce and even eliminate the need for RSUs altogether.he first part of the thesis focuses on highway networks: first, an analytical model is developed to analyze communication delay in scenarios with sparse bi-directional traffic, considering both disconnected and connected RSUs.hen, a study on connectivity and message dissemination in these networks reveals how significant benefits of RSUs are only achieved when the deployed RSUs are interconnected. Extensive simulation work paired with sets of experimental measurements validate both model and study. Supplementing the work on sparse highway networks, an infrastructure-less approach is then proposed, consisting of two methods to improve communication delays in these scenarios: decelerate disconnected vehicles as they receive safety messages, and boost the same vehicles’ radio transmit power, to shorten the time to restore connectivity. Both techniques are modeled analytically, and data from a simulation study validate the models and show significant improvements in the connectivity of sparse highway networks with this infrastructure-less approach. he second part of the thesis sets its sights on urban vehicular networks. High costs associated with RSUs prevent their deployment at scale, and therefore finding alternative solutions to this longstanding problem is very important. A novel, low-cost self-organizing network approach to leveraging parked cars as RSUs in urban areas is proposed here, enabling parked cars to create coverage maps based on received signal strength and to decide whether to become RSUs from that knowledge. Initial simulation work reveals significant benefits to emergency message broadcasting delay in sparse scenarios and shows the ability of the self-organizing approach in providing robust and widespread coverage to dense urban areas, using only a small fraction of the cars parked in a city. he parking behaviors of individual drivers are then studied, by analyzing and gathering statistics on travel survey data from various metropolitan areas. Daily and hourly analytical models of parking events are provided, along with important derivations.he statistical data show that parking events can be classified into two major groups based on the time a car spends parked, and that these patterns vary substantially throughout the day while being markedly similar across different cities. he last part of the thesis focuses on self-organization for parked car RSUs. Novel mechanisms for self-organization are introduced that are innovative in their ability to keep the network of parked cars under continuous optimization, in their multicriteria decision process, and in their control of each car’s battery usage, rotating roadside unit roles between vehicles as required.he first comprehensive study of the performance of such approaches is presented, via realistic modeling of mobility, parking, and communication, thorough simulations, and an experimental verification of concepts that are key to self-organization. his analysis leads to strong evidence that parked cars can serve as an alternative to fixed roadside units, and organize to form networks to support smarter transportation and mobility.
37

Implementación de olas verdes para la reducción del nivel de congestionamiento desde el jirón Huancas hasta la avenida Huancavelica en la avenida Giráldez y Paseo la Breña

Meza Apaza, Kheyko Annsherly Carmen 18 May 2017 (has links)
El problema de la congestión vehicular en la ciudad de Huancayo se acrecienta cada vez más, esto debido a algunos factores que desmejoran la situación. El principal factor es el crecimiento del parque automotor en contraste con la infraestructura vial; es decir, que la infraestructura vial colapsa debido a la gran demanda que existe, y como consecuencia se genera la congestión vehicular. Una de las vías más transitadas a causa de los centros comerciales, institutos, universidades, entre otros, es la Avenida Giráldez y Paseo la Breña, que a simple vista muestra un nivel de congestionamiento alto. Es por eso, que esta tesis busca reducir el nivel de congestionamiento en la línea de estudio. Para lo cual, se realizó el análisis de los niveles de congestionamiento de las intersecciones de la línea de estudio, que facilitó la solución del problema. Además, se determinó el tiempo de traslado desde el Jirón Huancas hasta la Avenida Huancavelica, el cual nos indicó que sí existía demora al transitarla. Asimismo, se determinó el ciclo del semáforo para cada una de las intersecciones. Todo esto, con el fin de reducir el nivel de congestionamiento desde el Jirón Huancas hasta la Avenida Huancavelica en la Avenida Giráldez y Paseo la Breña. / Tesis
38

Virtual Machine Management for Dynamic Vehicular Clouds

Refaat, Tarek January 2017 (has links)
Vehicular clouds involve a dynamic environment where virtual machines are hosted on moving vehicles, leading to frequent changes in the data center network topology. These frequent topological changes require frequent virtual machine migrations in order to meet the service level agreements with cloud users. Such topology changes include fluctuations in connectivity, signal strength and quality. Few studies address vehicles as potential virtual machine hosts, while there is a significant opportunity in capitalizing on underutilized resources. Due to the rapidly changing environment of a vehicular cloud, hosts frequently change or leave coverage. As such, virtual machine management and migration schemes are necessary to ensure cloud subscribers have a satisfactory level of access to the resources. This thesis addresses the need for virtual machine management for the vehicular cloud. First, a mobility model is proposed and utilized to test a set of novel Vehicular Virtual Machine Migration (VVMM) schemes: VVMM-U (Uniform), VVMM-LW (Least Workload), VVMM-MA (Mobility Aware) and MDWLAM (Mobility and Destination Workload Aware Migration). Their performance is evaluated with respect to a set of metrics through simulations with varying levels of vehicular traffic congestion, virtual machine sizes and load restriction levels. The most advanced scheme (MDWLAM) takes into account the workload and mobility of the original host as well as those of the potential destinations. By doing so a valid destination will both have time to receive the workload and migrate the new load when necessary. The behavior of various algorithms is compared and the MDWLAM has been shown to demonstrate the best performance, exhibiting migration drop rates that are negligibly small. Finally, an integer linear program formulation based on a modified single source shortest path problem is presented, tested and successfully shown to be a benchmark that can be used in comparison to the proposed heuristics.
39

Video Streaming in Vehicular Ad Hoc Networks: Challenges, Protocols and The Use of Redundancy

Rezende, Cristiano January 2014 (has links)
Vehicular Ad Hoc Networks (VANETs) are no longer a futuristic promise but rather an attainable technology. Vehicles are already equipped with a variety of computational devices that control or assist drivers in many tasks such as localization, safely breaking, parking and passengers entertainment. The majority of services envisioned for VANETs either require the provision of multimedia support or have it as an extremely beneficial additional feature. In particular, video streaming capabilities over VANETs are crucial to the development of interesting and valuable services. However,VANETs’ highly dynamic topology poses as a demanding challenge to the fulfillment of video streaming’s stringent requirements. The main goal on this thesis is the development of feasible solutions that support the streaming of video content over VANETs. Initially, the main issues of VANETs are explained through both a discussion of its characteristics and the results of some preliminary conclusions. Based on this understanding of VANETs’ peculiarities, three distinguishing solutions are designed REACT-DIS, REDEC and VIRTUS; the two first for video dissemination and the later for video unicast. These solutions offer a great advancement towards the provision of video streaming capabilities but packet loss is still an issue at high data rates. In order to improve the delivery ratios reached by the previous solutions, redundancy is used as an error correction mechanism. The use of redundancy is ideal for VANETs in handling packet loss as they do not require any interaction between source and receivers nodes. Sophisticated coding techniques were used for an efficient use of the increase on entropy of the information sent by the source node. It was also evaluated the selective use of redundancy solely on packets carrying the crucial information of I-frames. Although this selective approach obtained lower overall delivery ratios than when redundancy is used for all packets, the video quality obtained similar improvements under a much lower cost. The evaluation on the use of redundancy has considered the impact on the rate by which unique video content is received at end-users which is fundamental to understand the resolution of videos that can be displayed. This thesis provides several contributions as it advances the knowledge in the peculiarities of VANETs, solutions for video streaming over VANETs and the use of redundancy as an error correction mechanism for video streaming over VANETs.
40

Study of Connectivity Probability in Vanets by a Two-Dimensional Platoon-Based Model

Liu, Donglin 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / With the fast development of 5G networks and the advancement in networking technologies, more and more new technologies such as internet of vehicles (IoV) is catching our eyes. With technologies of artificial intelligence and automatic control, IoV is transformed into an intelligent transportation system (ITS). The object of this thesis is to analyze the connectivity probability issues in vehicle ad hoc networks (VANETs), which is a subset of ITS. This will be achieved by a platoon-based two dimensional model. In order to make the results more accurate and more close to real scenario, different situations will be analyzed separately, and different types of platoon will be included. In addition, other system parameters are also discussed and stimulated. The results show that many parameters like the increases of traffic density, ratio of platoon, and lane numbers will improve connectivity probability. No-leader based platoons are easier to connect to the base stations compared to leader based platoons.

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