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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.
91

Heuristic network generator : an expert systems approach for selection of alternative routes during incident conditions /

Krishnaswamy, Vijay. January 1994 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 97-100). Also available via the Internet.
92

Improving traffic flow conditions for interstate work-zones evaluation of three traffic control devices /

Shaik, Nawaz M. January 2005 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 11, 2006) Includes bibliographical references.
93

EFFECT OF MAJOR FACTORS ON BIOSWALE PERFORMANCE AND HYDROLOGIC PROCESSES FOR THE CONTROL OF STORMWATER RUNOFF FROM HIGHWAYS

Akhavan Bloorchian, Azadeh 01 May 2018 (has links)
Highways and roadways are the major source of stormwater runoff due to their prevalence and large non-permeable surface area. Best Management Practices (BMPs) such as bioswale provide effective on-site management and control of stormwater runoff from linear infrastructure such as highways. Many factors affect the performance of bioswales for stormwater volume reduction. The ratio of the installed BMP area to its service drainage area, characteristics of precipitation and the amount of sediment build-up over the surface of the BMP area are among the most important factors. Earlier studies have indicated that volume reductions in stormwater runoff from bioswale application range from 50% to 94%. However, the reported research lacks adequate information for a full understanding of how bioswales perform under various conditions. Consequently, additional systematic and in-depth research to better understand and the potential of bioswales as a method of controlling stormwater runoff is indicated. This research examined the effect of the following factors on bioswale performance: the ratio of the BMP area to the service drainage area, precipitation amounts and intensity, and sediment build-up. Hydraulic and hydrological processes were developed and analyzed through conceptual and physical models using appropriate governing equations including the Green-Ampt method. Field study of discrete rainfall events was conducted to collect information to calibrate and validate the numerical models. The field study tested various bioswale conditions with different levels of sediment accumulation. It also considered expected soil loss in the study area using the Universal Soil Loss Equation (USLE) method. In addition to field study, extensive simulations were conducted considering various contributing areas, rainfall depth and intensity, and sediment accumulation. These variables were manipulated to evaluate their effect on runoff volume reduction. Findings indicate that, for a given rainfall depth and duration, increasing the ratio of the BMP area to the service drainage area from 4% to16% results in increased bioswale efficiency ranging from 84% to 99%. The results revealed that input flowrate to the bioswale ranged from 0.04 to 4.7 in./min. depending on the rainfall intensity and soil type in the area. The runoff reduction performance of a newly constructed bioswale ranged from 44% for the highest input flowrate to 99% for the lowest input flowrate rainfall events. On the low end of rainfall volume/intensity, a 4% increase in the BMP area ratio results in a 34% improvement in efficiency (50% to 84%). On the high end of rainfall volume/intensity, a 16% increase in the area ratio results in only a 5% increase in efficiency (94% to 99%). Results also show that sediment accumulation has a substantial negative effect on infiltration rate. The observed efficiency of a bioswale in runoff reduction ranged from 13% to 100%. According to the USLE, the expected amount of soil loss occurring in the right-of-way area of a highway is approximately 1 ton/acre annually. The research revealed that for a given rainfall depth, duration, and area ratio; increasing the amount of sediment accumulation from 0 lbs./sq. ft. (equivalent to a newly constructed bioswale) to 2.7 lbs./sq. ft. (equivalent to a 10-year old bioswale) results in a 52% reduction in the runoff effectiveness of the bioswale sub-catchment from 98% to 46%. Finally, the physical model and associated governing equations were analyzed to describe the process of each studied factor. These results can be used for further study where the sediment accumulation rates differ from those modeled in this research.
94

Calibration of the Highway Safety Manual and development of new safety performance functions for rural multilane highways in Kansas

Aziz, Syeda Rubaiyat January 1900 (has links)
Doctor of Philosophy / Civil Engineering / Sunanda Dissanayake / Rural roads account for 90.3% of the 140,476 total centerline miles of roadways in Kansas. In recent years, rural fatal crashes have accounted for about 66% of all fatal crashes. The Highway Safety Manual (HSM) provides models and methodologies for analyzing the safety of various types of highways. Predictive methods in the HSM were developed based on national trends and data from few states throughout the United States. However, these methodologies are of limited use if they are not calibrated for individual jurisdictions or local conditions. The objective of this study was to analyze the HSM calibration procedures for rural multilane segments and intersections in Kansas. The HSM categorizes rural multilane segments as four-lane divided (4D) and four-lane undivided (4U) segments and rural multilane intersections as three-legged intersections with minor-road stop control (3ST), four-legged intersections with minor-road stop control (4ST), and four-leg signalized intersections (4SG). The number of predicted crashes at each segment was obtained according to the HSM calibration process. Results from calibration of rural segments indicated that the HSM overpredicts fatal and injury crashes by 50% and 65% and underpredicts total crashes by 48% and 64% on rural 4D and 4U segments, respectively. The HSM-given safety performance function (SPF) regression coefficients were then modified to capture variation in crash prediction. The adjusted models for 4D and 4U multilane segments indicated significant improvement in crash prediction for rural Kansas. Furthermore, Kansas-specific safety performance functions (SPF)s were developed following the HSM recommendations. In order to develop Kansas-specific SPF, Negative Binomial regression was applied to obtain the most suitable model. Several additional variables were considered and tested in the new SPFs, followed by model validation on various sets of locations. The Kansas-specific SPFs are capable of more accurately predicting total and fatal and injury crashes on multilane segments compared to the HSM and the modified HSM models. In addition to multilane segments, rural intersections on multilane highways were also calibrated according to the HSM methodology. Using crash modification factors for corresponding variables, SPFs were adjusted to obtain final predicted crash frequency at intersections. Obtained calibration factors indicated that the HSM is capable of predicting crashes at intersections at satisfactory level. Findings of this study can be used for improving safety of rural multilane highways.
95

An evaluation of wrong-way driving crashes on Kansas freeways.

Cunningham, Jack R. IV January 1900 (has links)
Master of Science / Department of Civil Engineering / Eric J. Fitzsimmons / Transportation officials continuously seek to prevent and reduce wrong-way crashes on interstate highways in the United States. These crashes typically have a high probability of head-on vehicle crashes, resulting in fatalities or serious injuries due to excessive vehicle speeds, and decreased room to maneuver because of fixed barriers or rough shoulders. This research project studied wrong-way crashes on interstate highways in Kansas in order to determine what, if any, statistically significant variables contribute to wrong-way driving crashes. Although these crashes represented only 0.05 percent of all vehicle crashes in Kansas in 2015, wrong-way crashes were found to have a higher rate of fatalities and injuries. In Kansas, 22.6 percent of all crashes and 56 percent of all wrong-way crashes resulted in fatalities and injuries, even though typical vehicle crashes in Kansas occur at non-intersection locations in daylight or in the presence of streetlights without negative factors of adverse weather conditions or drivers influenced by alcohol or drugs. Using crash data provided by the Kansas Department of Transportation from the years 2005 to 2015, the research team examined 372 wrong-way crashes. A cumulative logit statistical model was developed to identify significant characteristics of variables associated with each wrong-way crash. Results showed that driver not under the influence of alcohol or drugs was a significant characteristic in fatal and injury wrong-way crashes. Additionally, certain days of the week were associated with decreased vehicle crash rates when compared to the reference category.
96

Extração semi-automática de rodovias no espaço-objeto: uso integrado de um estéreo par de imagens aéreas e um MDT

Martins, Érico Fernando de Oliveira [UNESP] 09 December 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-09Bitstream added on 2014-06-13T19:27:42Z : No. of bitstreams: 1 martins_efo_me_prud.pdf: 7697728 bytes, checksum: 0a4768f80fcc4184fcaa8a4d6ead444b (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Nesta pesquisa é proposta uma metodologia semi-automática para extração de rodovias a partir de um estéreo par de imagens aéreas de baixa resolução e do respectivo Modelo Digital de Terreno, tendo por base a otimização por programação dinâmica no espaço-objeto. A metodologia consiste em um processo iterativo iniciado com pontos sementes fornecidos pelo operador no espaço-imagem, que após transformação para o espaço-objeto passam por ciclos de otimização via Programação Dinâmica até descreverem o eixo da rodovia. O desempenho da metodologia foi testado por meio de experimentos com dados reais, cujos resultados foram avaliados tanto na forma visual (qualitativamente) como numérica (quantitativamente). Os resultados alcançados nos experimentos demonstraram a robustez da metodologia diante de problemas de caráter geométrico e radiométrico comuns na extração semi-automática de rodovias a partir de imagens aéreas. Problemas de oclusão e baixa resposta radiométrica foram minimizados pelo uso de injunções globais, de natureza geométrica, bem como pela redundância e complementação de dados radiométricos provenientes das imagens que compõem o estéreo par. As linhas de busca multiresolução e os critérios de parada das iterações se mostraram como sendo importantes recursos na tentativa de conciliar extração de qualidade com baixo esforço computacional / This research proposes a semi-automatic methodology for road extraction by using a stereo pair of aerial images with low resolution, as well as Digital Terrain Model and dynamic programming in object-space. The methodology consists of an interactive process that starts with seed points provided by the operator in the space-image, which are later projected onto the space-object. Next, cycles of optimization are accomplished by the dynamic programming algorithm until the axis of the highway is correctly described. The performance of the methodology was tested with experiments by using real data, and results were evaluated both visually and numerically. The results achieved in the experiments have demonstrated the robustness of the methodology in face of geometrical and radiometric problems which are common in road extraction. Occlusions and low radiometric responses were minimized by the use of global geometric constraints, as well as the redundancy and complementation of radiometric data from the images that build the stereo pair. The line of multi-resolution search and stopping criteria of the interactions have showed themselves that they have been an important resort in the attempt to reconcile the extraction of high quality with low consumption of computational resources
97

Estimates of changes time space adjacent to roads in the amazon: case study BR 422 / Estimativas de mudanÃas espaÃo temporais adjacentes à rodovias na AmazÃnia: estudo de caso BR 422

Andrà Luis Fonseca Fontana 21 November 2011 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / This paper presents a method for generating estimates of temporal changes in the surrounding area of a highway located in the Amazon, using the technique Cellular Automata and explanatory variables, only attributes of the land. The proposed model uses vector images (obtained from the National Institute for Space Research in Brazil), which are converted to grid type files â raster image, representing a series of spatial changes in the region of study. With this proposition, it is expected to assist decision makers in order to meet the requests of CONAMA Resolution 01, relating to environmental impacts, more specifically, as regards the construction of models which consider scenarios with and without the project, and that the process of construction / rehabilitation of roads can be made in view of the legal norms in order to minimize potential environmental and social impacts. The model generated from the CAs showed promise in generating future estimates of deforestation and a good quantitative and qualitative indicators to support the decision making process to consider future deforestation being caused by construction and / or paving of road in the Amazon. / Este trabalho apresenta um mÃtodo para a estimativa de mudanÃas espaÃo temporais no entorno de uma rodovia localizada na AmazÃnia, utilizando para tanto a tÃcnica AutÃmatos Celulares adaptada em ambiente SIG, onde as variÃveis explicativas do modelo serÃo somente os atributos do terreno. O modelo proposto usa imagens vetoriais (obtidas junto ao Instituto Nacional de Pesquisas Espaciais) que posteriormente sÃo convertidas para arquivos tipo grid â em formato raster, com a sÃrie histÃrica das mudanÃas espaciais na regiÃo objeto de estudo. Espera-se auxiliar os tomadores de decisÃo no atendimento das solicitaÃÃes da resoluÃÃo CONAMA 01/86 relativas à concepÃÃo de modelos que considerem cenÃrios com e sem o empreendimento, e que os processos de construÃÃo/recuperaÃÃo de rodovias possam ser realizados atendendo Ãs normas legais, visando minimizar os potenciais impactos sÃcio ambientais. O modelo gerado a partir dos ACs mostrou-se promissor na geraÃÃo de estimativas futuras de desmatamento e um bom indicador quantitativo e qualitativo para suporte no processo de tomada de decisÃo que pondere o desmatamento futuro a ser causado pela construÃÃo e/ou pavimentaÃÃo de uma rodovia na AmazÃnia.
98

Uma análise descritiva histórica dos materiais utilizados na pavimentação: a história da pavimentação no município de Porto Velho/Rondônia no período de 1978 a 2014

Moraes, Gilson Castro de 10 June 2016 (has links)
Submitted by Adriely Bruce (adriely_bruce@hotmail.com) on 2016-12-02T15:17:12Z No. of bitstreams: 1 Dissertação - Gilson Castro de Moraes.pdf: 6811083 bytes, checksum: a8a15535e7682fe2dedbede2e12db103 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-02T19:29:12Z (GMT) No. of bitstreams: 1 Dissertação - Gilson Castro de Moraes.pdf: 6811083 bytes, checksum: a8a15535e7682fe2dedbede2e12db103 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-02T19:31:47Z (GMT) No. of bitstreams: 1 Dissertação - Gilson Castro de Moraes.pdf: 6811083 bytes, checksum: a8a15535e7682fe2dedbede2e12db103 (MD5) / Made available in DSpace on 2016-12-02T19:31:47Z (GMT). No. of bitstreams: 1 Dissertação - Gilson Castro de Moraes.pdf: 6811083 bytes, checksum: a8a15535e7682fe2dedbede2e12db103 (MD5) Previous issue date: 2016-06-10 / This thesis aims to present a Historicaldescriptive analysis of paving in the city of Porto Velho / Rondônia from 1978 to 2014. Starting from the history of civilizations, from Brazil’s history comes to the history of the region and consequently the history of Porto Velho and regional paving. The paving should walk along with a region’s development, especially when it is far from the major decision-making centers of the country. It sought to achieve the proposed objectives through literature review, historical research and lived expertise along the delimiter of the study period. Aspects of social economy, regional physicalindications, formation and occupation of Rondônia, the history of paving in the state and in the capital, emphasizing the 36 year period marked out this work. The territorial occupation of the city of Porto Velho is detailed since the beginning, in the early twentieth century to the present. Through this study we found that from the beginning there was a tremendous influence of economic cycles on all that occurred in Rondônia, with the paving was no different, having an influence on each cycle. It is also worth mentioning that despite the difficulties, over these thirty-six years, there was an improvement in the quality of materials used in paving. With the knowledge of history, the experiences in the past, the settings are carried out in the present for a future development is achieved. / A presente dissertação visa apresentar uma Análise Descritiva Histórica da pavimentação no município de Porto Velho/Rondônia no período de 1978 a 2014. A partir da história das civilizações, da história do Brasil chega-se a história da região e consequentemente a história de Porto Velho e a pavimentação regional. A pavimentação deve caminhar junto com o desenvolvimento de uma região, principalmente quando essa região está distante dos grandes centros decisórios do país. Buscou-se alcançar os objetivos propostos através de revisão bibliográfica, pesquisas históricas e conhecimento técnico vivencial ao longo do período delimitador do estudo. Os aspectos de sócio economia, índices físicos regionais, a formação e ocupação de Rondônia, a história da pavimentação no estado e na capital, com ênfase no período de 36 anos balizaram esse trabalho. A ocupação territorial do município de Porto Velho é detalhada desde os primórdios, no inicio do século XX, até a atualidade. Através do presente trabalho constatamos que desde os primórdios houve uma tremenda influência dos ciclos econômicos sobre tudo que ocorreu em Rondônia, com a pavimentação não foi diferente, havendo uma influência em cada ciclo. Ressalte-se também que apesar das dificuldades, ao longo desses trinta e seis anos, houve um avanço na qualidade dos materiais utilizados na pavimentação. Com o conhecimento da história, as experiências vividas no passado, efetuam-se os ajustes no presente para que um futuro de desenvolvimento seja alcançado.
99

Seção transversal de rodovias vicinais, qualidade de viagens e comportamento de pavimentos / Cross section, quality of trip and pavement performance in local highways

Rubem Ribeiro de Freitas 29 February 2000 (has links)
Relatam-se e discutem-se resultados obtidos em ações de uma tentativa para mostrar que o formato da seção transversal de rodovias pode ser usado para explicar uma parcela do comportamento de pavimentos e qualidade de viagens em estradas vicinais. Incluiu-se o uso de medidas sobre variáveis para explicação de estado de equipamentos para drenar água das vias. O tipo de variável usada para explicar o comportamento de pavimentos e qualidade de viagens foi a distribuição de notas atribuídas a viagens por segmentos de rodovias por um grupo de avaliadores treinados. A técnica estatística usada para análise dos dados foi a regressão linear múltipla passo a passo. Relata-se resultados de aplicação a um estudo de caso sobre um conjunto de rodovias vicinais próximo à Araraquara, estado de São Paulo. / lt is related and discussed the results from actions in an attempt to show that the format of the cross section of highways can be used to explain the behavior of the pavements and quality of trips in local highways. Measures on variables to explain the state of drainage equipments was taking into account. The variable used to explain the behavior of pavements and quality of trips was the distribution of scores attributed to the highway segments trips by a group of trained appraisers. The statistical technique used to analyze the data was the multiple linear step-by-step regressions. lt is told the application results to a case study on a set of local highway segments near the city of Araraquara, State of Sao Paulo.
100

Avaliação da capacidade operacional rodoviária de uma passagem em nível / Operational Capacity Evaluation of Highway-rail grade crossing

Benzi, Joyce Felisbina Carpanez, 1984- 25 August 2018 (has links)
Orientador: Cassio Eduardo Lima de Paiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-25T18:39:41Z (GMT). No. of bitstreams: 1 Benzi_JoyceFelisbinaCarpanez_M.pdf: 4589963 bytes, checksum: d5c188f05dc140935277219394181843 (MD5) Previous issue date: 2014 / Resumo: As passagens em nível são formadas pela interseção de vias de dois modais de transporte terrestres com características físicas e operacionais distintas. Estas travessias são gargalos no sistema de transportes rodoviário. Os motoristas são obrigados a parar seus veículos antes de atravessar um cruzamento rodoferroviário, devido ao direito de passagem adquirido pela ferrovia, que por sua vez, também reduz a sua velocidade para evitar colisões, principalmente no perímetro urbano. Estas interseções são trechos de descontinuidade para a via, onde o fluxo rodoviário e o Nível de Serviço ficam reduzidos consideravelmente. Com base nessa situação foi realizado um levantamento de campo, em seis passagens em nível, na região Sudeste do país para a avaliação dos fluxos operacionais dos veículos rodoviários existentes. Através destes dados pretende-se desenvolver uma análise crítica dos volumes escoados através de métodos que estimam o fluxo de saturação e o atraso veicular. Para valores referentes ao tempo de espera dos usuários são encontrados Níveis de Serviço correspondentes, onde é possível classificar a viabilidade das vias existentes. Enquanto para novas vias foi desenvolvido um gráfico dinâmico exibindo os números máximos de veículos e trens que podem utilizar o sistema de acordo com o nível de serviço exigido, consequentemente a viabilidade da via / Abstract: The highway-rail grade crossings are constituted by the intersection of two modals of transportation with distinct physical and operational characteristics. These crossings are the bottlenecks in the highway transportation system. The drivers are required to stop their vehicles before cross a grade crossing, due the right-of-way acquired by the railroad, which in turn also reduce your speed to avoid collisions, principally in the urban perimeter. Theses intersections are points of discontinuity for the way, where the flow is reduced and the road service level is reduced considerably. Based on this situation was conducted a field survey in six level crossings in the Southern Brazil for the evaluation of operational flows of existing road vehicles. Through these information, will be develop a critical analysis of the volumes disposed of by methods that estimate the saturation flow and vehicular delay. Amounts related to the waiting time for users are found corresponding Level of Service where you can sort the viability of existing roads. While for new roads was develop a dynamic graphic showing the maximum numbers of vehicles and trains that can use the system according to the level of service required, hence the viability of the road / Mestrado / Transportes / Mestra em Engenharia Civil

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