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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.
1

The Effect Of In-vehicle Warning Systems On Driverresponse In Work Zones

Whitmire, James James, II 01 January 2007 (has links)
This research investigated the effectiveness of in-vehicle information technologies on driver behavior in work zones. In-vehicle information devices can increase driver awareness to an oncoming change in traffic flow and provide specific guidelines for driving speed requirements, lane merging strategies, or unexpected changes in the roadway (e.g., detours and lane shifts). The overall conditional effects for vehicle speed are significant; that is, both the audio and visual groups out performed the control group within the simulated work zone. Participants in audio group did outperform the visual group, not significantly though. The overall conditional effects for total time in violation are significant; that is, both the audio and visual groups out performed the control group. The test session results for Total Time in Violation were statistically significant, F(2, 57) = 7.17, p ≤ .01. The strength of relationship between the warning messages and the Total Time in Violation with regular road signage, as assessed by η2 , was strong, the warning message factor accounting for 20% of the variance of the dependent variable.
2

Range Modulation Strategy for Minimizing Interference in Vehicle-to-Vehicle Safety Communication

Parrish, Mason D. 22 April 2022 (has links)
No description available.
3

The effect of ambient lighting combined with EVA warning on driver reaction

Ondomisi, Petr January 2023 (has links)
Emergency vehicles are at increased traffic risk due to legal exemptions like speeding or running red lights during emergencies. These exemptions can cause delays and complications in their response. The study explored if warning messages to passenger car drivers, particularly the EVA (Emergency Vehicle Approaching) message, with or without ambient lighting, could improve safety and response. A driving simulator experiment with 60 participants tested the impact of different levels of warning, including the EVA message and augmented ambient lighting (AEL). Participants also completed pre- and post-experiment questionnaires. The test involved a rural road scenario with background music to challenge emergency vehicle detection. Results showed significant behavioural differences between drivers receiving no warning and those receiving either form of warning, but no significant difference between the two warned groups. While attitudes towards this technology were positive, further research on the effectiveness of ambient lighting is needed. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
4

An Informed System Development Approach to Tropical Cyclone Track and Intensity Forecasting

Roy, Chandan January 2016 (has links)
Introduction: Tropical Cyclones (TCs) inflict considerable damage to life and property every year. A major problem is that residents often hesitate to follow evacuation orders when the early warning messages are perceived as inaccurate or uninformative. The root problem is that providing accurate early forecasts can be difficult, especially in countries with less economic and technical means. Aim: The aim of the thesis is to investigate how cyclone early warning systems can be technically improved. This means, first, identifying problems associated with the current cyclone early warning systems, and second, investigating if biologically based Artificial Neural Networks (ANNs) are feasible to solve some of the identified problems. Method: First, for evaluating the efficiency of cyclone early warning systems, Bangladesh was selected as study area, where a questionnaire survey and an in-depth interview were administered. Second, a review of currently operational TC track forecasting techniques was conducted to gain a better understanding of various techniques’ prediction performance, data requirements, and computational resource requirements. Third, a technique using biologically based ANNs was developed to produce TC track and intensity forecasts. Systematic testing was used to find optimal values for simulation parameters, such as feature-detector receptive field size, the mixture of unsupervised and supervised learning, and learning rate schedule. Five types of 2D data were used for training. The networks were tested on two types of novel data, to assess their generalization performance. Results: A major problem that is identified in the thesis is that the meteorologists at the Bangladesh Meteorological Department are currently not capable of providing accurate TC forecasts. This is an important contributing factor to residents’ reluctance to evacuate. To address this issue, an ANN-based TC track and intensity forecasting technique was developed that can produce early and accurate forecasts, uses freely available satellite images, and does not require extensive computational resources to run. Bidirectional connections, combined supervised and unsupervised learning, and a deep hierarchical structure assists the parallel extraction of useful features from five types of 2D data. The trained networks were tested on two types of novel data: First, tests were performed with novel data covering the end of the lifecycle of trained cyclones; for these test data, the forecasts produced by the networks were correct in 91-100% of the cases. Second, the networks were tested with data of a novel TC; in this case, the networks performed with between 30% and 45% accuracy (for intensity forecasts). Conclusions: The ANN technique developed in this thesis could, with further extensions and up-scaling, using additional types of input images of a greater number of TCs, improve the efficiency of cyclone early warning systems in countries with less economic and technical means. The thesis work also creates opportunities for further research, where biologically based ANNs can be employed for general-purpose weather forecasting, as well as for forecasting other severe weather phenomena, such as thunderstorms.
5

Improving Vehicular ad hoc Network Protocols to Support Safety Applications in Realistic Scenarios

Martínez Domínguez, Francisco José 20 January 2011 (has links)
La convergencia de las telecomunicaciones, la informática, la tecnología inalámbrica y los sistemas de transporte, va a facilitar que nuestras carreteras y autopistas nos sirvan tanto como plataforma de transporte, como de comunicaciones. Estos cambios van a revolucionar completamente cómo y cuándo vamos a acceder a determinados servicios, comunicarnos, viajar, entretenernos, y navegar, en un futuro muy cercano. Las redes vehiculares ad hoc (vehicular ad hoc networks VANETs) son redes de comunicación inalámbricas que no requieren de ningún tipo de infraestructura, y que permiten la comunicación y conducción cooperativa entre los vehículos en la carretera. Los vehículos actúan como nodos de comunicación y transmisores, formando redes dinámicas junto a otros vehículos cercanos en entornos urbanos y autopistas. Las características especiales de las redes vehiculares favorecen el desarrollo de servicios y aplicaciones atractivas y desafiantes. En esta tesis nos centramos en las aplicaciones relacionadas con la seguridad. Específicamente, desarrollamos y evaluamos un novedoso protocol que mejora la seguridad en las carreteras. Nuestra propuesta combina el uso de información de la localización de los vehículos y las características del mapa del escenario, para mejorar la diseminación de los mensajes de alerta. En las aplicaciones de seguridad para redes vehiculares, nuestra propuesta permite reducir el problema de las tormentas de difusión, mientras que se mantiene una alta efectividad en la diseminación de los mensajes hacia los vehículos cercanos. Debido a que desplegar y evaluar redes VANET supone un gran coste y una tarea dura, la metodología basada en la simulación se muestra como una metodología alternativa a la implementación real. A diferencia de otros trabajos previos, con el fin de evaluar nuestra propuesta en un entorno realista, en nuestras simulaciones tenemos muy en cuenta tanto la movilidad de los vehículos, como la transmisión de radio en entornos urbanos, especialmente cuando los edificios interfieren en la propagación de la señal de radio. Con este propósito, desarrollamos herramientas para la simulación de VANETs más precisas y realistas, mejorando tanto la modelización de la propagación de radio, como la movilidad de los vehículos, obteniendo una solución que permite integrar mapas reales en el entorno de simulación. Finalmente, evaluamos las prestaciones de nuestro protocolo propuesto haciendo uso de nuestra plataforma de simulación mejorada, evidenciando la importancia del uso de un entorno de simulación adecuado para conseguir resultados más realistas y poder obtener conclusiones más significativas. / Martínez Domínguez, FJ. (2010). Improving Vehicular ad hoc Network Protocols to Support Safety Applications in Realistic Scenarios [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/9195
6

Adolescent Interest in Alcohol Responsibility Messages: The Message Matters

John, Kevin Kimball 12 November 2009 (has links) (PDF)
Adolescents are especially vulnerable to image-based messages, which place them directly in line with the lifestyle messages presented in numerous alcohol advertisements. Research has shown that teenagers encounter alcohol advertisements from a variety of sources, prompting concern over the consequences of exposure and the risks associated with teen drinking. Warning messages contained within these alcohol advertisements are often vague in their wording and targeted to promote responsible drinking among adults, making them wholly inadequate for teen deterrence. This thesis explores the problems with current alcohol responsibility messages when dealing with teens, and proposes the development of new, modified messages, that are more direct and consequence-based. The Elaboration Likelihood Model of persuasion was used to describe teen processing of alcohol warning messages, and eye-tracking technology was used to determine how this processing can be examined visually. The purpose of this research was to aid in the development of new messages that have been modified by type size, type contrast, and message content (a 2x2x2 factorial design). Results indicated that modifying message content to include direct language and a consequence enhances visibility and attention to alcohol responsibility messages. Larger type and higher contrast can be applied to the message to further enhance visibility, but the change in attention for these factors was shown to be minimal and nonsignificant. Overall, the greatest power lies in changing the message itself, irrespective of all other variables.

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