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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.
311

Desenho do sistema de solução de conflito: sistemas indenizatórios em interesses individuais homogêneos / Dispute system design: indemnity systems in class interest.

Ostia, Paulo Henrique Raiol 16 April 2014 (has links)
Por mais que os cientistas separem e classifiquem os elementos da realidade para melhor compreendê-la, ele preserva a sua natureza complexa e multidisciplinar. O mesmo raciocínio pode ser aplicado aos conflitos. A sociedade de massa, por sua vez, potencializou o surgimento de conflitos complexos. As peculiaridades e os diferentes aspectos destas situações tornam improvável que sejam adequadamente tratados e solucionados por mecanismos genéricos. Considerando isso e em uma perspectiva de meios adequados de solução de conflito, o método do desenho de sistemas de solução de conflito (Dispute System Design DSD) propõe que sejam criados sistemas personalizados a partir de princípios e técnicas. Dessa forma, seriam dadas as respostas processuais aos diferentes aspectos do conflito. Com o intuito de analisar a aplicação dos princípios e técnicas do DSD à realidade, estudar-se-ão os casos da Câmara de Indenização Voo 3054 (CI3054) e do Programa de Indenização Voo 447 (PI447). Estes sistemas tinham como escopo solucionar os conflitos provenientes de acidentes aéreos que ocorreram em 2007 e 2009, com aeronaves das companhias TAM e Air France, respectivamente. Nas duas tragédias não houve sobreviventes. / Although the scientists separate and classify the elements of reality to understand it better, it preserves its complex and multidisciplinary nature. The same reasoning can be applied to conflicts. The mass society, in its turn, increased the emergence of complex conflicts. The peculiarity and the different aspects of these situations makes it unlikely to be adequately processed and solved by generic mechanisms. Considering this and the perspective of adequate conflict resolution, the Dispute System Design - DSD suggests that custom systems can be created from principles and technical. Therefore would be given the procedural responses to the different aspects of the conflict. In order to examine the application of the principles and techniques of DSD to reality, will be studied the cases of the Câmara de Indenização Voo 3054 (CI3054) and Programa de Indenização Voo 447 (PI447). These systems were scoped to resolve conflicts arising from plane crashes that occurred in 2007 and 2009, with TAM and Air France aircraft. In the two tragedies there were no survivors.
312

Relationship between traffic operations and road safety / Relações entre a operação de tráfego e segurança viária

Gustavo Riente de Andrade 18 December 2018 (has links)
Since before the release of the Highway Safety Manual research has been indicating the need to incorporate mobility and control aspects to road safety analysis. The first part of this work developed and implement in an existing computational engine a signal timing optimization method that considers mobility, safety, and emissions measures simultaneously. A sensitivity analysis was conducted to provide insight on the practical effects and order of relevance of 20 key input variables. Mobility improvement performance usually coincides with emissions improvements, but sometimes at the expense of safety. The second part of this work investigated the relationship between hourly traffic density and crash rates on Brazilian expressways with different characteristics, based on a database containing over 20,000 crashes and more than 35 million traffic volume observations and. The resulting curves for urban expressways follow a U shape, with minimum values associated with LOS B to C, while the relationships for rural expressways were found to be continuously increasing, suggesting that low volume rural roads are safer than the higher volume ones. The analysis of other influencing factors revealed that nighttime conditions, weaving segments and urban multilane highways could be related to higher crash rates. The third part of the project extends the analysis to crash severity modeling, using an ordered response choice model. The framework that better fit this database led to the development of two different models: single-vehicle crashes (SV) and multiple-vehicle crashes (MV), since the factors that explain the severity of crashes varies widely between these models. For instance, guardrails and barriers proved to effectively reduce severity for SV crashes, for which run-offs are the most severe crash type. The unique database used in this study also allowed for an investigation of the influence of prevailing traffic conditions on crash severity, while still controlling for all other factors. The results suggested that multiple-vehicle crash severity is negatively related with traffic density, while single-vehicle crashes are more closely related to speed. The findings of this work have implications to policy and design decisions, and the produced equation could be incorporated to active traffic management (ATM) and HCM reliability analysis. / Desde antes da publicação do Highway Safety Manual, vários pesquisadores indicam a necessidade de se incorporar aspectos de operação de tráfego à análise de segurança viária. A primeira parte deste trabalho desenvolveu e implementou em uma ferramenta computacional existente um método de otimização de tempos semafóricos que considera medidas de desempenho de operação, segurança e emissões simultaneamente. Uma análise de sensibilidade foi realizada para produzir conhecimento sobre os efeitos práticos e a ordem de relevância de 20 variáveis de entrada principais. O desempenho da programação semafórica em termos de redução dos atrasos geralmente coincide com redução das emissões, embora às vezes às custas da segurança. A segunda parte deste trabalho investigou a relação entre a densidade horária de tráfego e as taxas de acidentes em autoestradas e rodovias de pista dupla brasileiras com características diversas, com base em um banco de dados contendo mais de 20.000 registros de acidentes e mais de 35 milhões de observações de tráfego. As curvas resultantes para rodovias urbanas seguem um formato em U, com valores mínimos associados aos níveis de serviço B a C, enquanto que as relações para as rodovias rurais são contínuas e crescentes, sugerindo que rodovias rurais de baixo volume são mais seguras do que as de maior volume. A análise de outros fatores revelou que condições noturnas, segmentos de entrelaçamento e rodovias de pista dupla convencionais urbanas estariam relacionadas a maiores taxas de acidentes. A terceira parte deste projeto amplia a análise para modelagem de severidade dos acidentes, usando um modelo de escolha discreta ordenado. A estrutura que melhor se adequa a esse banco de dados levou ao desenvolvimento de dois modelos diferentes: acidentes com um veículo e acidentes com múltiplos veículos, já que os fatores que explicam a severidade dos acidentes variam muito entre esses modelos. Por exemplo, defensas e barreiras se mostraram efetivas para a redução da severidade de acidentes com um veículo, para as quais a saída de pista é o tipo de acidente mais grave. O amplo banco de dados usado neste estudo também permitiu uma investigação da influência das condições de tráfego na severidade do acidente, em comparação com todos os outros fatores. Os resultados sugeriram que a severidade de acidentes de múltiplos veículos está negativamente relacionada com a densidade de tráfego, enquanto colisões com um único veículo estão mais relacionadas à velocidade. As descobertas deste trabalho têm implicações nas decisões sobre políticas e projetos de transportes, e a equação produzida pode ser incorporada à análise de confiabilidade do gerenciamento ativo do tráfego (ATM) e do Highway Capacity Manual.
313

Scaling methods, health preferences and health effects

Cubí Mollá, Patricia 16 March 2009 (has links)
No description available.
314

EFFECT OF SOCIOECONOMIC AND DEMOGRAPHIC FACTORS ON KENTUCKY CRASHES

Cambron, Aaron Berry 01 January 2018 (has links)
The goal of this research was to examine the potential predictive ability of socioeconomic and demographic data for drivers on Kentucky crash occurrence. Identifying unique background characteristics of at-fault drivers that contribute to crash rates and crash severity may lead to improved and more specific interventions to reduce the negative impacts of motor vehicle crashes. The driver-residence zip code was used as a spatial unit to connect five years of Kentucky crash data with socioeconomic factors from the U.S. Census, such as income, employment, education, age, and others, along with terrain and vehicle age. At-fault driver crash counts, normalized over the driving population, were used as the dependent variable in a multivariate linear regression to model socioeconomic variables and their relationship with motor vehicle crashes. The final model consisted of nine socioeconomic and demographic variables and resulted in a R-square of 0.279, which indicates linear correlation but a lack of strong predicting power. The model resulted in both positive and negative correlations of socioeconomic variables with crash rates. Positive associations were found with the terrain index (a composite measure of road curviness), travel time, high school graduation and vehicle age. Negative associations were found with younger drivers, unemployment, college education, and terrain difference, which considers the terrain index at the driver residence and crash location. Further research seems to be warranted to fully understand the role that socioeconomic and demographic characteristics play in driving behavior and crash risk.
315

Adapting Crash Modification Factors for the Connected and Autonomous Vehicle Environment

Lause, Federico Valentin, III 01 January 2019 (has links)
The Crash Modification Factor (CMF) clearinghouse can be used to estimate benefits for specific highway safety countermeasures. It assists safety professionals in the allocation of investments. The clearinghouse contains over 7000 entries of which only 446 are categorized as intelligent transportation systems or advanced technology, but none directly address connected or autonomous vehicles (CAVs). Further, the effectiveness of highway safety countermeasures is assumed to remain constant over time, an assumption that is particularly problematic as new technologies are introduced. For example, for the existing fleet of human-driven vehicles, installation of rumble strip can potentially reduce “run-off-road” crashes by 40%. If specific CAV technologies, e.g., lane-tracking, can work without rumble strips, and say, half of all cars are so equipped, only half of the fleet will benefit, reducing the benefits of rumble strips by a commensurate amount. Benefits of the two improvements, e.g., rumble strips and automated vehicles, should not be double-counted. As there will still be human-driven and/or non-connected vehicles in the fleet, conventional countermeasures are still necessary, although returns on conventional safety investments may be significantly overestimated. This is important as safety investments should be optimized and geared to future, not past fleets. Moreover, as CMFs are based on historical events, the types of crashes experienced by human-driven, un-connected cars are likely to be much different in the future. This research presents methods to estimate the safety benefits that autonomous vehicles have to offer and the changes needed in CMFs as a result of their adoption. This will primarily be achieved by modifying and enhancing a tool co-developed by the Fellow that estimates the safety benefits of different levels of autonomy. This tool, ddSAFCAT, estimates CAV safety benefits using real-world data for crashes, market penetration, and effectiveness.
316

Geomagnetic Compensation for Low-Cost Crash Avoidance Project

Torres, John C 01 April 2011 (has links)
The goal of this work was to compensate for the effects of the Earth’s magnetic field in a vector field magnetic sensor. The magnetic sensor is a part of a low-cost crash avoidance system by Stephane Roussel where the magnetic sensor was used to detect cars passing when it was mounted to a test vehicle. However, the magnetic sensor’s output voltage varied when it changed orientation with respect to the Earth’s magnetic field. This limited the previous work to only analyze detection rates when the test vehicle travelled a single heading. Since one of the goals of this system is to be low-cost, the proposed solution for geomagnetic compensation will only use a single magnetic sensor and a consumer-grade GPS. Other solutions exist for geomagnetic compensation but use extra sensors and can become costly. In order to progress the development of this project into a commercial project, three separate geomagnetic compensation algorithms and a calibration procedure were developed. The calibration procedure compensated for the local magnetic field when the magnetic sensor was mounted to the test vehicle and allowed for consistent magnetic sensor voltage output regardless of the type of test vehicle. The first algorithm, Compensation Scheme 1 (CS1), characterized the local geomagnetic field with a mathematical function from field calibration data. The GPS heading was used as the input and the output is the voltage level of the Earth’s magnetic field. The second algorithm, Compensation Scheme 1.5, used a mathematical model of the Earth’s magnetic field using the International Geomagnetic Reference Field. An algorithm was developed to take GPS coordinates as an input and output the voltage contributed by the mathematical representation of the Earth’s magnetic field. The output voltages from CS1 and CS1.5 were subtracted from the calibrated magnetic sensor data. The third algorithm, Compensation Scheme 2 (CS2), used a high pass filter to compensate for changes of orientation of the magnetic sensor. All three algorithms were successful in compensating for the geomagnetic field and vehicle detection in multiple car headings was possible. Since the goal of the magnetic sensor is to detect vehicles, vehicle detection rates were used to evaluate the effectiveness of the algorithms. The individual algorithms had limitations when used to detect passing cars. Through testing, it was found that CS1 and CS1.5 algorithms were suitable to detect vehicles while stopped in traffic while the CS2 algorithm was suitable vehicle detection while the test vehicle is moving. In order to compensate for the limitations of the individual algorithms, a fused algorithm was developed that used a combination of CS1 and CS2 or CS1.5 and CS2. The vehicle speed was used in order to determine which algorithm to use in order to detect cars. Although the goal of this project is not vehicle detection, the rate of successful vehicle detection was used in order to evaluate the algorithms. The evaluation of the fused algorithm demonstrated the value of using CS1 and CS1.5 to detect vehicles when stopped in traffic, which CS2 algorithm cannot do. For a study conducted in traffic, using the fused algorithm increased vehicle detection rates by 51%-62% from using the CS2 algorithm alone. Since this work successfully compensated for geomagnetic effects of the magnetic sensor, the low-cost crash avoidance system can be further developed since it is no longer limited to driving in a single direction. Other projects that experience unwanted geomagnetic effects in their projects can also implement the knowledge and solutions used in this work.
317

Seat Belt Fit a Mechanism of Injury During a Motor Vehicle Crash

Viljoen, Jacoba Hendrika 01 January 2018 (has links)
Seat belts save lives; however, unintentional injuries are still the leading cause of death for those between 1 and 44 years in the United States. Seat belts also cause injuries during motor vehicle crashes (MVCs) and obesity changes how seat belts fit. The purpose of this retrospective causal inference quantitative study was to reduce the knowledge gap in scholarly research on seat belt fit in relation to blunt cerebrovascular injuries (BCVI) during MVCs and seat belt compliance. The theoretical framework used was based on H.W. Heinrich's domino theory. The research questions focused on the following dependent variables: BCVI, compliance, and seat belt fit; and independent variables: the size of the individual and seat belt fit. Secondary and primary data were used and analyzed using Spearman's Rank-Order Correlation. The results yielded no relationship between seat belt fit and BCVI in the secondary data (n = 97). In the primary data (n = 138), there was significance found between seatbelt fit and a) seat belt use, and b) BMI. The study contributed to positive social change by enhancing the awareness of the knowledge deficit regarding seat belt fit, and BCVIs sustained during MVCs, and that comfort was influenced by seat belt fit and had a role in compliance. Seat belts were not used by 5.3% and 9.5% or used incorrectly by 3.2% and 2.9% of the people in the primary data and secondary data sets. This knowledge may contribute to a) future seat belt testing to ensure it is done in such a manner that seat belts fit everyone; b) new seat belt laws to ensure that they are consistent across all states, and c) medical care focusing on seat belt fit as a mechanism of injury (blunt) to ensure screenings are done with the appropriate diagnostic tools.
318

使用熱物理中臨界點現象來預測金融危機 / Using critical phenomena to predict financial crashes

李嘉文, Lee, Grant Unknown Date (has links)
在此篇論文之前, 已經有許多學者指出在金融市場奔盤之前的價格波動與熱物理學中的臨界現象有所類似. 其價格會呈現Power law的形式迅速加速上升, 同時伴隨著log-periodic震盪. 藉由first-order Landau expansion和second-order Landau expansion, 我們使用了50個隨機樣本, 分別從五個不同的指數來驗證其正確性. 結果發現該模型很難運用在高波動的市場, 但是對於中級波動的市場卻有不錯的預測能力, 比方說S&P500與Nikkei 225指數. / Before this paper, many scholars indicated that market price movement before a crash is similar to critical phenomena. It can be described by a power law acceleration of the market price decorated with log-periodic oscillations. By first-order Landau expansion and second-order Landau expansion, we use 50 random samples from each of 5 different indices to test the model. It is hard to adapt Landau expansion to high volatility indices, but fit pretty well for medium volatility indices, such as S&P 500 and Nikkei 225.
319

Mécanismes de rupture des côtes et critères de tolérance thoracique en choc automobile

Diet, Stéphane 19 January 2005 (has links) (PDF)
La mise en évidence d'une divergence entre l'accidentologie et les crashs tests demande de revisiter les critères de tolérance thoracique. En parallèle, l'émergence des mannequins numériques de crash permet d'appréhender des lésions particulières ; ce que ne permet pas le mannequin physique Hybrid III. Parmi ces lésions, il y a la fracture de côte. Dans ce contexte, ce travail s'est centré sur la réalisation et la validation d'un modèle numérique lésionnel personnalisé des côtes en choc automobile. Se référant à la bibliographie, il a été choisi de faire des essais de flexion trois points, en incluant des mesures de déformations par jauges et un suivi cinématique par vidéo. Les conditions d'essais ont été définies à partir de plusieurs modèles : système masse-ressort ; RDM ; calculs en éléments finis ; et des mesures réalisées sur SHPM. En amont des essais, chaque côte a été scannée pour étudier la géométrie et pouvoir générer son maillage personnalisé en éléments finis. Les essais statiques, utilisant les côtes 6, 8 et 10, montrent un effort maxi croissant des côtes 6 vers 10 et un déplacement à l'effort maxi nettement supérieur pour la côte 10. Les essais dynamiques, avec une vitesse par niveau de côte et un impacteur différent par côté (impacteurs cylindrique et type ceinture) donnent une influence très nette de la vitesse ainsi que de la géométrie de l'impacteur. Il existe une vitesse optimum concernant cet essai, en terme d'effort maxi, comprise entre 0,10 et 0,25 m.s-1. Alors que la ruine de la côte a lieu pour un même déplacement, l'impacteur ceinture permet de supporter un effort maximum supérieur de 30% ; ce qui est cohérent avec les observations en accidentologie. L'étude géométrique montre que les caractéristiques de la côte évoluent avec le niveau, mais pas la concentration linéique de minéraux. Enfin, les premiers modèles numériques lésionnels personnalisés, visant dans un premier temps à reproduire les essais, valident la faisabilité de la démarche et ouvrent des perspectives de développement.
320

Evaluation of Roadside Collisions with Utility Poles and Trees at Intersection Locations

Mattox, Todd Berry 15 November 2007 (has links)
The United States averages 40,000 traffic fatalities annually. The American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide cites run-off-the-road crashes as contributing greatly to this statistic, with about one-third of all traffic deaths [1]. This number has remained relatively constant over the past four decades, and despite a major increase in vehicle miles traveled (VMT), the rate of fatalities per 100 million vehicle miles traveled has declined. However, this relatively large number of run-off-the-road crashes should remain a major concern in all roadway design. The Highway Safety Act of 1966 marks a defining moment in the history of roadside safety [ ]. Before this point, roadways were only designed for motorists who remained on the roadway, with no regard for driver error. As there was no legislation or guidelines concerning roadside design, roadways constructed prior to 1966 are littered with fixed objects directly off of the edge of pavement. Fortunately, many of these roads have reached their thirty year design lives and have become candidates for improvement. The following report examines roadside crashes on nine Atlanta urban arterial roadways. Accident type, severity, and location for all crashes on these were evaluated. It is found roadside collisions with utility poles and trees were more prone to occur at intersection locations than midblock locations. Also for the studied roadway corridors, on average, roadside collisions were more likely to result in serious injury or fatality. Based on these findings initial recommendations are offer for improving clear zone requirements.

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