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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.
281

Diferenças entre a retórica e a prática na implantação do Metrô de São Paulo / Differences between rhetoric and practice in the implementation of the São Paulo Metro

Geraldo José Calmon de Moura 13 June 2016 (has links)
O discurso que vincula as políticas de transporte às de uso e ocupação do solo data, no caso do metrô paulistano, da década de 1970, momento da implantação dos primeiros exemplos desses equipamentos na cidade, e foi acompanhado da constatação dos fortes impactos e das profundas alterações no uso do solo que essa infraestrutura causava no entorno. No entanto, contrariando o discurso corrente e oficial, a prática cotidiana mostrou que essa integração não se verificou enquanto política pública ou, quando muito, apenas buscou considerar os impactos da valorização imobiliária como estratégia de captura/ transferência de recursos de parte dessa valorização nas cercanias do metrô para financiar a ampliação daquela infraestrutura. O presente trabalho procura entender as razões que motivaram essa larga diferença entre a retórica governamental e a prática nos processos de implantação da malha metroviária paulistana. Busca, ainda, analisar as razões que levaram ao insucesso desse vínculo, apesar da vontade explicitada nos discursos do poder público e da existência, mais recentemente, de elementos técnicos e urbanísticos que, em tese, facilitariam a viabilização dessas intenções. Para isso, analisaremos ao longo das quatro últimas décadas, os projetos metroviários paulistanos, o arcabouço legal urbanístico, os planos urbanos e de transporte, comparando o conteúdo expresso nas respectivas formulações com a dinâmica ocorrida ao longo dos processos de implantação. / The discourse that links transport policies to those of land use and occupation date, in the case of the São Paulo subway, in the 1970s, when the first examples of such equipment were installed in the city, and it was accompanied by the strong impacts and the deep Changes in land use that this infrastructure caused in the environment. However, contrary to current and official discourse, daily practice showed that this integration did not take place as a public policy or, at most, only sought to consider the impacts of real estate valuation as a strategy for capturing / transferring resources from part of this valuation in the neighborhoods Of the subway to finance the expansion of that infrastructure. The present work tries to understand the reasons that motivated this wide difference between the governmental rhetoric and the practice in the processes of implantation of the São Paulo metro network. It also seeks to analyze the reasons that led to the failure of this link, despite the will expressed in the speeches of the public power and the existence, more recently, of technical and urban elements that, in theory, would facilitate the viability of these intentions. To do so, we will analyze over the last four decades, São Paulo\'s subway projects, urban legal framework, urban and transportation plans, comparing the content expressed in the respective formulations with the dynamics that occurred throughout the implementation processes.
282

Densidades urbanas econômicas: a influência do transporte público / Economical urban densities: the influence of urban public transportation

Antônio Nélson Rodrigues da Silva 02 March 1990 (has links)
Neste trabalho é enfocado o problema das densidades urbanas econômicas. É feita uma análise de alguns estudos existentes sobre a questão da densidade urbana ideal, sob o ponto de vista econômico, e avaliada, através de um modelo especialmente desenvolvido, qual a influência do custo do transporte coletivo na definição da densidade ideal. Também são discutidos, ainda que de forma não aprofundada, os limites de densidade populacional suportados pelo homem. As conclusões a que se chega são que as densidades econômicas, sob vários critérios, estão, seguramente, acima de 200 habitantes por hectare e que, os limites humanos situam-se em torno de 500 habitantes por hectare. Esses valores, quando comparados às densidades em torno de 40 habitantes por hectare apresentados pelas cidades médias brasileiras, comprovam a forma irracional com que o solo urbano vem sendo ocupado no país, constituindo, o fato, um dos graves problemas que hoje o Brasil enfrenta. / The issue of economical urban densities is analyzed in this study. Related studies about ideal urban densities under the economic point of view are initially discussed, leading to the development of a model designed to evaluate the influence of urban public transportation on the definition of economical densities. Some considerations about density population limits that human beings can bear are also presented. The results suggest that economical densities are over 200 persons/ha whereas the human limits are around 500 persons/ha. The comparison of these values with the density values of Brazilian medium-sized cities (around 40 persons/ha) shows that the urban land occupation in Brazil is not rational, which is currently a serious problems for the country.
283

Estudo da incorporação da acessibilidade à atividade na análise da demanda por viagens encadeadas / Incorporation of accessibility to opportunities on the activity-based travel demand analysis

Silva, Mateus Araújo e 25 November 2011 (has links)
O objetivo desta pesquisa é validar a hipótese de que a acessibilidade à oportunidades influencia o comportamento dos padrões de viagens desempenhados pelos indivíduos. Para realizar a verificação desta hipótese foi formulado um procedimento (um teste de hipótese) baseado em um estudo de caso realizado na cidade de Uberlândia, utilizando informações sobre: (i) as características dos deslocamentos dos indivíduos, suas características demográficas e de participação em atividades; (ii) informações sobre o sistema de transportes, e; (iii) informações sobre a distribuição espacial das atividades. Para atingir a finalidade proposta na tese, foram elaborados procedimentos que constituem no processo de verificação da hipótese nula, constituído pelas seguintes etapas: (i) tratamento dos dados; (ii) construção das variáveis (iii) proposta para avaliação da acessibilidade no contexto da formação dos padrões de viagens; (iv) escolha de técnicas de modelagem do comportamento individual referente às decisões sobre padrões de viagens; (v) seleção das técnicas estatísticas para avaliação da significância das variáveis e desempenho dos modelos; (vi) modelagem para simulação do comportamento individual em três níveis de decisão da programação diária de atividades, modo de viagem, destino da atividade primária e padrão de viagens, e; (vii) análise dos resultados obtidos e conclusão sobre a hipótese. Após a realização do experimento realizado com as informações da cidade de Uberlândia, concluiu-se que pela verificação realizada não há elementos para rejeitar a hipótese nula, ou seja, a acessibilidade a oportunidades influencia o comportamento dos padrões de viagens encadeadas desempenhados pelos indivíduos. / The main aim of this work is to submit to a validation test the hypothesis that the accessibility to opportunities influences individuals\' trip chaining behavior. To perform the hypothesis test a procedure was developed on a study case in the city of Uberlandia, using data about: (i) characteristics of the individuals\' trips, their demographic features and activity participation; (ii) transportation system information, and; (iii) information about the spatial distribution of activities. To achieve the purpose of the thesis, it was developed procedures which consist in the hypothesis test, made by the following stages: (i) data processing; (ii) setting of the variables; (iii) a proposal to evaluate the accessibility on the context of trip chaining patterns; (iv) choosing modeling techniques to represent individual behavior regarding to its decisions on trip chaining patterns; (v) selection of statistical techniques for measures of model and variable performance; (vi) modeling individual behavior on three decision levels of the daily activity schedule, mode choice, destination choice and trip chaining patterns, and; (vii) discussion of the results and conclusion about the hypothesis. The main conclusion is that the hypothesis cannot be rejected, i.e., accessibility to opportunities influences individuals\' trip chaining behavior.
284

Estudo da influência da acessibilidade no valor de lotes urbanos através do uso de redes neurais. / A study of the influence of accessibility on urban land values using artificial neural networks.

Brondino, Nair Cristina Margarido 21 December 1999 (has links)
Um dos problemas freqüentes em modelos de avaliação de imóveis é identificar quais de suas características devem ser levadas em consideração e o quanto cada uma destas influencia no valor final das propriedades. Além disso, é necessário um critério de avaliação bem estruturado, baseado em modelagem matemática adequada. A partir das constatações acima, foram estabelecidos os objetivos deste trabalho: após identificar as principais variáveis que interferem no valor das propriedades, avaliar o uso de Redes Neurais Artificiais para fins de avaliação e estudar a influência de uma medida de acessibilidade no valor de terrenos urbanos. Quanto às variáveis a serem empregadas nos modelos de avaliação, chegou-se a conclusão que um banco de dados misto, onde tanto variáveis de natureza espacial quanto física pudessem ser incluídas, parecia ser uma opção interessante. Desta forma, após a inclusão no banco de dados de uma variável de natureza espacial, a distância ao centro da cidade, este trabalho comparou dois métodos de avaliação: as Redes Neurais Artificiais e o modelo de regressão múltipla, este último muito usado na prática. Foram abordados dois estudos de caso, as cidades de Araçariguama e São Carlos. A primeira é uma cidade dormitório, de pequeno porte (cerca de 6000 habitantes), localizada nas proximidades da capital do estado, São Paulo. A segunda, por sua vez, é uma cidade de porte médio (cerca de 160000 habitantes), localizada no centro do estado e pólo industrial e tecnológico. A escolha destas cidades ofereceu a oportunidade de estudar a influência de uma variável como a acessibilidade em contextos diferentes. Os resultados obtidos para Araçariguama indicaram que a medida de acessibilidade empregada, distância ao centro, era uma das variáveis mais importantes na formação do preço de propriedades. Quanto aos resultados obtidos pelos modelos empregados, pôde-se observar que, ao utilizar regressão múltipla, o efeito da variável distância ao centro não pode ser estudado sozinho, pois esta variável interage com a área. A utilização de Redes Neurais, por sua vez, também forneceu estimativas adequadas de valor, verificando-se através dela que a acessibilidade apresentou um peso superior a 34% no valor final. Ao se comparar os dois métodos pode-se observar que as Redes Neurais (RN) demonstraram um desempenho superior, quando este foi avaliado pelo valor do erro relativo total. Com o objetivo de analisar a distribuição espacial dos erros, estes foram agrupados em cinco clusters, podendo-se constatar que os maiores erros fornecidos pelas RN se concentraram em um único bairro. Na análise para São Carlos pôde-se verificar também, através dos resultados obtidos por ambos os métodos, que a distância ao centro foi um dos fatores preponderantes na avaliação dos imóveis. A análise da distribuição espacial dos erros apontou uma concentração de erros maiores em um dos bairros, o que pôde ser observado para os dois métodos empregados e dois dos três conjuntos de dados. Um fato que chamou a atenção foi o de que para Araçariguama, que é uma cidade de porte menor, a importância relativa da variável acessibilidade foi maior que para a outra cidade. / A common problem in the use of land valuation models is the identification of the real estate features that should be incorporated in the models and how they influence the final property price. In addition, a well structured approach based in consistent mathematical models is also required. Based on the aforementioned assertions, the following objectives have been drawn for this work: after identifying the main variables that have a strong influence on land values, the use of Artificial Neural Networks (ANN) for land valuation have be tested and the influence of an accessibility measure on urban land values have been studied. Regarding the variables that should been part of the valuation models, we reached the conclusion that a mixed database containing physical and spatial attributes seemed to be an interesting option for this sort of problem. Therefore, after the addition of a spatial variable, the distance to the city center, to our database, two valuation methods have been compared: the ANN approach and a multiple regression model, the latter quite common in practice. Two case studies have been then analyzed: the cities of Araçariguama and São Carlos. The first one is a small bedroom town (around 6,000 inhabitants) not far from the state capital, the city of São Paulo. The second one is a medium-sized city (around 160,000 inhabitants) located in the middle of the state and a technological and industrial center. The particularities of these two cities made possible a comparison of the influence that such a variable as accessibility could have on the land values under two different conditions. The results obtained for the city of Araçariguama indicated that the accessibility measure used, the distance from the city center, was one of the main variables influencing land prices. Although both models gave good estimates, their results were not exactly the same. While the influence of the variable distance to the city center could not be individually taken in the multiple regression model, because of its interaction with the variable area, the same variable has a strong weight on the ANN model, in which it appears as responsible for over 34% of the land value. The ANN performed better in a direct comparison of the two approaches, specially when looking to the total relative error. With the purpose of analyzing the spatial distribution of the estimation errors, they have been grouped into clusters, which have stressed that the worst cases are concentrated in a specific area of the city. Both methods showed that the distance to the city center has a strong influence on land values also in the city of São Carlos. The highest estimation errors were also concentrated in a specific neighborhood for two out of three data sets in both valuation methods. Another interesting outcome is the fact that the relative weight of the accessibility variable used was higher in Araçariguama than in São Carlos, although the former city is smaller than the latter.
285

Patterns of Freight Flow and Design of a Less-than-Truckload Distribution Network

Dave, Devang Bhalchandra 12 April 2004 (has links)
A less-than-truckload (LTL) carrier typically delivers shipments less than 10,000 pounds (classified as LTL shipment). The size of the shipment in LTL networks provides ample opportunities for consolidation. LTL carriers have focused on hub-and-spoke based consolidation to realize economies of scale. Generally, hub-and-spoke systems work as follows: the shipment is picked up from the shipper and brought to an origin terminal, which is the entry point into the hub-and-spoke system. From the terminal, the freight is sent to the first hub, where it is sorted and consolidated with other shipments, and then sent on to a second hub. It is finally sent from the second hub to the destination terminal, which is the exit point of the hub-and-spoke system. However, the flow of shipments is often more complicated in practice. In an attempt to reduce sorting costs, load planners sometimes take this hub-and-spoke infrastructure and modify it considerably to maximize their truck utilization while satisfying service constraints. Decisions made by a load planner may have a cascading effect on load building throughout the network. As a result, decentralized load planning may result in expensive global solutions. Academic as well as industrial researchers have adapted a hierarchical approach to design the hub-and-spoke networks: generate the hub-and-spoke network, route shipments within this hub-and-spoke network (generate a load plan) and finally, balance the empty trailers. We present mathematical models and heuristics for each of the steps involved in the design of the hub-and-spoke network. The heuristics are implemented in a user-friendly graphical tool that can help understand patterns of freight flow and provide insights into the design of the hub-and-spoke network. We also solved the load planning sub-problem in a parallel computation environment to achieve significant speed-ups. Because of the quick solution times, the tool lays the foundation to address pressing further research questions such as deciding location and number of hubs. We have used data provided by Roadway Parcel Services, Inc. (RPS), now FedEx Ground, as a case-study for the heuristics. Our solutions rival the existing industry solutions which have been a product of expensive commercial software and knowledge acquired by the network designers in the industry.
286

Planning Robust Freight Transportation Operations

Morales, Juan Carlos 20 November 2006 (has links)
This research focuses on fleet management in freight transportation systems. Effective management requires effective planning and control decisions. Plans are often generated using estimates of how the system will evolve in the future; during execution, control decisions need to be made to account for differences between actual realizations and estimates. The benefits of minimum cost plans can be negated by performing costly adjustments during the operational phase. A planning approach that permits effective control during execution is proposed in this dissertation. This approach is inspired by recent work in robust optimization, and is applied to (i) dynamic asset management and (ii) vehicle routing problems. In practice, the fleet management planning is usually decomposed in two parts; the problem of repositioning empty, and the problem of allocating units to customer demands. An alternative integrated dynamic model for asset management problems is proposed. A computational study provides evidence that operating costs and fleet sizes may be significantly reduced with the integrated approach. However, results also illustrate that not considering inherent demand uncertainty generates fragile plans with potential costly control decisions. A planning approach for the empty repositioning problem is proposed that incorporates demand and supply uncertainty using interval around nominal forecasted parameters. The intervals define the uncertainty space for which buffers need to be built into the plan in order to make it a robust plan. Computational evidence suggests that this approach is tractable. The traditional approach to address the Vehicle Routing Problem with Stochastic Demands (VRPSD) is through cost expectation minimization. Although this approach is useful for building routes with low expected cost, it does not directly consider the maximum potential cost that a vehicle might incur when traversing the tour. Our approach aims at minimizing the maximum cost. Computational experiments show that our robust optimization approach generates solutions with expected costs that compare favorably to those obtained with the traditional approach, but also that perform better in worst-case scenarios. We also show how the techniques developed for this problem can be used to address the VRPSD with duration constraints.
287

Transportation asset management systems: a risk-oriented decision making approach to bridge investment

O'Har, John Patrick 08 July 2011 (has links)
Transportation Asset Management (TAM) systems are in use at a significant number of transportation agencies. These systems can be used to effectively allocate resources and continuously inventory and monitor the condition of transportation infrastructure assets. Risk-oriented decision making is becoming an increasingly important component of the management process at many organizations, including transportation agencies. TAM systems can be used to incorporate risk assessment and risk management techniques at transportation agencies. To demonstrate the value of incorporating risk in TAM systems, an examination of the literature was performed, and a case study was conducted. This case study incorporated risk in bridge project prioritization through the utilization of data from the National Bridge Inventory (NBI), and application of Multi Attribute Decision Making (MADM) concepts to address uncertainty and prioritize selected bridges in the state of Georgia. The case study examines the impacts of data aggregation and disaggregation, and the incorporation of uncertainty on bridge project prioritization. Results of this analysis show that when available, disaggregate data on bridge condition should be used. In addition, uncertainty, in terms of performance risk, should be incorporated when past bridge condition data is available. Furthermore, decision-maker input is an important component of the Multi Attribute Utility Theory (MAUT) prioritization methodology used in this analysis. Decision-makers determine the relative importance of certain attributes, which is one of the strengths of this type of prioritization effort.
288

Transportation planning via location-based social networking data : exploring many-to-many connections

Cebelak, Meredith Kimberly 17 September 2015 (has links)
Today’s metropolitan areas see changes in populations and land development occurring at faster rates than transportation planning can be updated. This dissertation explores the use of a new dataset from the location-based social networking spectrum to analyze origin-destination travel demand within Austin, TX. A detailed exploration of the proposed data source is conducted to determine its overall capabilities with respect to the Austin area demographics. A new methodology is proposed for the creation of origin-destination matrices using a peer-to-peer modeling structure. This methodology is compared against a previously examined and more traditional approach, the doubly-constrained gravity model, to understand the capabilities of both models with various friction functions. Each method is examined within the constructs of the study area’s existing origin-destination matrix by examining the coincidence ratios, mean errors, mean absolute errors, frequency ratios, swap ratios, trip length distributions, zonal trip generation and attraction heat maps, and zonal origin-destination flow patterns. Through multiple measures, this dissertation provides initial interpretations of the robust Foursquare data collected for the Austin area. Based upon the data analytics performed, the Foursquare data source is shown to be capable of providing immensely detailed spatial-temporal data that can be utilized as a supplementary data source to traditional transportation planning data collection methods or in conjunction with other data sources, such as social networking platforms. The examination of the proposed peer-to-peer methodology presented within this dissertation provides a first look at the potential of many-to-many modeling for transportation planning. The peer-to-peer model was found to be superior to the doubly-constrained gravity model with respect to intrazonal trips. Furthermore, the peer-to-peer model was found to better estimate productions, attractions, and zone to zone movements when a linear function was used for long trips, and was computationally more proficient for all models examined.
289

Light rail impacts on property values : analyzing Houston's METRORail

Campbell, Elizabeth Cochrane 13 July 2011 (has links)
Light rail transit (LRT) systems are tools to help reduce traffic congestion and air pollution, promote high-density development and more affordable housing, and curtail urban sprawl in metropolitan cities throughout the United States. The impact of transit system services on property values has been studied from various perspectives using many statistical approaches. There are two general categories of effects that proximity to a light rail system can have on the value of residential properties: accessibility benefits (experienced in close proximity to the LRT stations) might increase property values, while nuisance qualities (experienced in both proximity to the LRT line and stations) could have a negative effect on residential property values. Due to the opposing nature of these coexisting effects, results from many empirical studies have been contradictory or inconclusive. This report reviews the spectrum of results found by the growing body of literature focusing on the capitalization effects of rail stations on property values. The economic effect of one particular LRT system, the 7.5 mile long METRORail line located in Houston, Texas, on the value of properties within close proximity to rail stations has not been thoroughly examined, as it only opened for service in 2004. This study utilizes property data acquired from the Harris County Appraisal District (HCAD), Geographic Information System (GIS) techniques, and Hedonic Price Models to analyze the impact of the LRT system in the city of Houston, Texas, on the value of residential properties that lie within close proximity to the line’s rail stations. / text
290

The privatisation of car parking facilities in Hong Kong

Yip, Kwok-ching., 葉國正. January 1983 (has links)
published_or_final_version / Public Administration / Master / Master of Social Sciences

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