• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • 7
  • 1
  • 1
  • Tagged with
  • 22
  • 22
  • 12
  • 11
  • 10
  • 10
  • 10
  • 10
  • 10
  • 8
  • 8
  • 6
  • 6
  • 5
  • 5
  • 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.
11

Mobility and Transnationalism: Travel Patterns and Identity among Palestinian Canadians

Zaidan, Esmat 25 January 2011 (has links)
Increased urban diversity in the metropolises of North America urges us to examine the different forms of mobility of transnational communities in cosmopolitan societies. Recent technological advancements, including developments in transport and communication networks, have significantly influenced participation in transnational activities and belonging to transnational social spaces. This study examines the relationships between long-term mobility (migration) and short-term mobility (tourism) by investigation the “visiting friends and family” travel of immigrants that best exemplifies the nexus between the two contemporary phenomena. As increasing levels of globalization and international migration are likely to be accompanied by increased transnationalism, the research uses transnationalism as a conceptual framework to study immigrants’ overseas travel. Research into the relationship between tourism and migration requires engaging with issues of citizenship as different categories of migrants have different rights in the country of settlement. This has implications for travel as revealed in the movements that occur between the places of origin of immigrants (which become destinations) and the new places of residence (which become new origins). These movements are likely to be influenced by the rights and duties of immigrants as citizens living within and moving around different states. This study examines the relationship between the overseas travel patterns of immigrants and their citizenship status. It also examines the role of ethnic and family reunion in shaping these travel patterns. The study also provides a deeper theoretical and empirical analysis of the role of ethnic reunion in shaping the travel patterns of immigrants and of the social and cultural meanings associated with the travel to the ancestral homeland. All of these issues are tackled by examining Palestinian immigrants in the Greater Toronto Area (GTA) and by employing a mixed methods approach engaging both quantitative and qualitative data collection and analysis. Major research methods that are employed in the research include key informant interviews, questionnaire surveys, in-depth interviews, observation and field notes, and the use of secondary data. The study explored the politics of mobility for Palestinian-Canadians, an understudied population in terms of transnational practices and issues of identity and hybridity. It also explored issues of citizenship and belonging using extensive interview data with Palestinian-Canadians in the GTA. Throughout the thesis the highly politicized aspect of mobility/immobility, national identity, and national autonomy in the Palestinian case was present. The research highlighted the continuing role of state actors in determining mobility and rights, despite the increasing rhetoric of borderless mobility. The study reveals that the majority of the Palestinian Canadians travel overseas regularly and their outbound travel patterns demonstrate a significant ethnic component. Palestinian Canadians travel to their country of birth as their dominant outbound travel destination for the purposes of visiting friends and relatives and maintaining social and cultural ties, indicating strong ties with homeland that have ethnic links. However, Palestinians holding Canadian citizenship have a higher propensity to travel overseas than permanent resident. The return visits have social and cultural significance to the first and second generations. However, these return visits do not facilitate return migration.
12

Mobility and Transnationalism: Travel Patterns and Identity among Palestinian Canadians

Zaidan, Esmat 25 January 2011 (has links)
Increased urban diversity in the metropolises of North America urges us to examine the different forms of mobility of transnational communities in cosmopolitan societies. Recent technological advancements, including developments in transport and communication networks, have significantly influenced participation in transnational activities and belonging to transnational social spaces. This study examines the relationships between long-term mobility (migration) and short-term mobility (tourism) by investigation the “visiting friends and family” travel of immigrants that best exemplifies the nexus between the two contemporary phenomena. As increasing levels of globalization and international migration are likely to be accompanied by increased transnationalism, the research uses transnationalism as a conceptual framework to study immigrants’ overseas travel. Research into the relationship between tourism and migration requires engaging with issues of citizenship as different categories of migrants have different rights in the country of settlement. This has implications for travel as revealed in the movements that occur between the places of origin of immigrants (which become destinations) and the new places of residence (which become new origins). These movements are likely to be influenced by the rights and duties of immigrants as citizens living within and moving around different states. This study examines the relationship between the overseas travel patterns of immigrants and their citizenship status. It also examines the role of ethnic and family reunion in shaping these travel patterns. The study also provides a deeper theoretical and empirical analysis of the role of ethnic reunion in shaping the travel patterns of immigrants and of the social and cultural meanings associated with the travel to the ancestral homeland. All of these issues are tackled by examining Palestinian immigrants in the Greater Toronto Area (GTA) and by employing a mixed methods approach engaging both quantitative and qualitative data collection and analysis. Major research methods that are employed in the research include key informant interviews, questionnaire surveys, in-depth interviews, observation and field notes, and the use of secondary data. The study explored the politics of mobility for Palestinian-Canadians, an understudied population in terms of transnational practices and issues of identity and hybridity. It also explored issues of citizenship and belonging using extensive interview data with Palestinian-Canadians in the GTA. Throughout the thesis the highly politicized aspect of mobility/immobility, national identity, and national autonomy in the Palestinian case was present. The research highlighted the continuing role of state actors in determining mobility and rights, despite the increasing rhetoric of borderless mobility. The study reveals that the majority of the Palestinian Canadians travel overseas regularly and their outbound travel patterns demonstrate a significant ethnic component. Palestinian Canadians travel to their country of birth as their dominant outbound travel destination for the purposes of visiting friends and relatives and maintaining social and cultural ties, indicating strong ties with homeland that have ethnic links. However, Palestinians holding Canadian citizenship have a higher propensity to travel overseas than permanent resident. The return visits have social and cultural significance to the first and second generations. However, these return visits do not facilitate return migration.
13

Understanding the Linkages between Urban Transportation Design and Population Exposure to Traffic-Related Air Pollution: Application of an Integrated Transportation and Air Pollution Modeling Framework to Tampa, FL

Gurram, Sashikanth 17 November 2017 (has links)
Rapid and unplanned urbanization has ushered in a variety of public health challenges, including exposure to traffic pollution and greater dependence on automobiles. Moreover, vulnerable population groups often bear the brunt of negative outcomes and are subject to disproportionate exposure and health effects. This makes it imperative for urban transportation engineers, land use planners, and public health professionals to work synergistically to understand both the relationship between urban design and population exposure to traffic pollution, and its social distribution. Researchers have started to pay close attention to this connection, mainly by conducting observational studies on the relationship between transportation, urban form, and air quality. However, research on this topic is still nascent. Further, most studies do not predict exposures under alternative urban design scenarios. Hence, to understand the relationship between urban design and population exposures, there is a need to build and apply integrated modeling tools that can predict exposures under alternative urban design scenarios. Within this context, the overarching goal of this dissertation is to understand how the transportation infrastructure of cities can be designed for improved urban air quality and mitigation of population exposure to traffic pollution. The study area is Hillsborough County, Florida, a sprawling region with limited transit availability and a diverse population along with a mix of urban, suburban, and rural areas. The rank of the county for sprawl and congestion metrics (i.e., yearly delay and travel time index) fall in the mid-range in comparison with other US urban regions. Thus, the study area may be representative of other US urban regions with medium sprawl and above-average congestion levels. Oxides of nitrogen (NOx), a surrogate for traffic pollution, is the focus pollutant. The Health Effects Institute’s report on traffic-related air pollution identifies NOx as a potential surrogate due to its relative ease of measurement and the abundance of epidemiologic studies that characterize exposures to NOx. Because exposures are dependent on the spatial and temporal distributions of both people and pollution, this study first sought to understand the importance of activity and travel patterns of individuals for exposure estimation. To estimate exposures, the 2009 National Household Travel Survey (NHTS) data containing daily individual activity records, ArcGIS-estimated shortest-time travel route profiles, and the annual-average diurnal cycle of NOx derived from hourly CALPUFF dispersion model results from 2002, were combined. Two exposure measures were estimated: activity-based exposure that considers the daily activity and travel patterns of individuals, and residence-based exposure that considers only the pollutant concentrations at the residences. Exposure estimation without inclusion of activity and travel patterns was found to slightly underestimate activity-based exposures on average. Additionally, disproportionately-high exposures were found for blacks, Hispanics, below poverty groups, urban residents, and people whose daily travel time is greater than one hour. Finally, urbanicity and travel time variables were found to be the strongest predictors of daily exposure. Following this, a modeling framework was developed to predict population exposure by integrating activity-based travel demand modeling (DaySim), dynamic traffic assignment simulation (MATSim), mobile-source emission estimation (EPA MOVES), and pollutant dispersion modeling (R LINE). This modeling framework was used to predict daily population and subgroup exposures by estimating the high-resolution spatial and temporal distributions of both pollution and individual activities for the year 2010. Persistent exposure inequalities were found at the population-level; blacks, Hispanics, active age groups (19-65 years), below-poverty and middle-income groups, urban residents, and individuals with daily travel times above one hour had higher estimated exposures than the population mean. These inequalities for blacks, Hispanics, and below-poverty non-white groups worsened at higher exposure levels. Use of low-resolution activity and pollution data as opposed to high-resolution data led to underestimation of exposures (by 10% on average). Finally, the integrated modeling framework was employed to understand the relationship between urban transportation and land use design, air quality, and population exposure. Three scenarios that are based on a combination of diesel-bus transit services and residential distribution were simulated. Specifically, the low-transit scenario used the 2040 base residential distribution and the 2010 bus services. The enhanced-transit scenario applied the 2040 bus services proposed for the county instead. The compact-growth scenario added an increase of residential density to this latter scenario. Specifically, about 37% of total households were redistributed from locations with low accessibility to jobs and transit to locations near employment and bus stops. Results indicate slight higher non-car travel mode shares in the enhanced-transit and compact-growth scenarios compared to the low-transit scenario (with a 7.1% increase for walking, 0.2% for bicycle, and 1.8% for transit for the compact-growth scenario versus the low-transit scenario). The enhanced-transit scenario resulted in slightly lower daily total travel distances and times compared with the low-transit scenario, but daily total emissions and winter mean concentration of NOx were higher, i.e., the increase in bus transit services did not induce sufficient shifts in travel mode to overcome the concomitant increase in diesel-bus emissions. The compact-growth scenario resulted in lower daily total travel distance (9%) and travel time (2.1%) and daily total emissions of NOx (11%) and its winter mean concentration (9%), compared with both the low-transit and enhanced-transit scenarios. Although the compact-growth scenario improved the air quality of the region on average, daily population mean exposure was higher compared with both the low-transit (29%) and enhanced-transit scenarios (25%). This is largely due to the redistribution of population to urban core locations that had higher pollutant levels. Overall, neither the bus-transit improvements nor residential compaction strategies alone were sufficient to mitigate population exposures. Combining them with transit that services both origins and destinations, uses clean fuel technologies, and separates major roadways from dense residential pockets may be needed for greater exposure reductions. Overall, this dissertation has implications for population exposure to traffic pollution and public health through transportation and land use interventions. Results presented here may be applicable to other study regions that have similar composite sprawl scores as the Tampa Bay area. Future studies should exploit spatially-and temporally-resolved data on human activities and travel, vehicular activities, and air quality for better characterization of population exposure. Engineers and planners should pay greater attention to integrated land use and transport planning; lone, disjointed, and ill-planned design interventions may exacerbate population exposure to air pollution. The integrated modeling framework presented here may be applied in a wide variety of urban contexts to further explore the nexus between travel demand, air quality, and exposures. However, before such an exercise is undertaken, a preliminary analysis should be conducted to assess the transferability of the framework. Policies that could be studied include mixed land use design, urban compaction with controlled sociodemographic distributions (to assess exposure inequality), and inclusion of additional types of transit and fuel technologies.
14

Artificial Environments and Spatial Travel Implications: The case of Madrid Snow Zone

Lipasti, Johannes January 2017 (has links)
Place has been a fundamental topic for geographers (Agnew, 1987). It stands both for a study object and a manner of perceiving the world. This thesis departs from the theoretical debate regarding places and how places are considered as being spatially fixed in the sense that places cannot be reproduced or imitated elsewhere. However, technological innovations have extraordinary significance in all the realms of leisure and lifestyle (Godbey, 1997) whereas, leisure activities increasingly are being simulated and reproduced exemplifying the new postmodern culture and the ‘post-tourist’ (Urry, 1990). Thus, challenges the spatial fix of places (Shaw & Williams, 2004). There has been little empirical research regarding artificial environments and therefore, the research problem contributes to understand how artificial environments are altering habitual travel patterns regarding the ‘genuine’ or as previous authors have stated, regarding the ‘real thing’. The research questions proposed for the study, directed the researcher to a quantitative approach using the questionnaire as a main source of data collection. The simulated environment that was investigated in the study was the indoor ski slope located in Madrid (Spain). The results showed that the simulated environment is enhancing and intervening the ski activity. For most of the skiers the indoor ski slope is complementing their ski activity in front of the outdoor ski resorts. Furthermore, the facility is recruiting every year a great number of new skiers that after skiing indoors desire to experience the ‘real thing’. Due to the proximity of the facility to the major urban areas, the indoor ski slope is acting as an intervening opportunity and boosting the visitors towards outdoor skiing.
15

Bothnian Disparity Routes : A qualitative study on travel patterns between Umeå and Vaasa

Schulman, William January 2024 (has links)
Finland and Sweden share a common history that dates back to the 12thcentury, when the two countries were one. Sweden has throughout time, for numerous reasons, been a more well-developed country and has had a larger economy than Finland, which has made moving and travelling to Sweden amongst Finns a rather common demographic feature. The effects of this historical relationship, and of these events, still to this day influencethe travel patterns between the two countries; More Finns visit Sweden than Swedes visit Finland.Throughout this thesis I analyse and describe the uneven passenger transportation patterns between the Swedish city of Umeå and the Finnish city Vaasa. By analysing inhabitants personal background together with the motives for travelling to-, the knowledge about-, and the perceived mental distance between Umeå and Vaasa of inhabitants in both cities, I strive to find answers to the Bothnian disparity routes. The results of the study points towards social bonds, various cultural factors, possession of knowledge, and perceived mental distance playing asignificant role in shaping the travel patterns between the two cities. Furthermore, the result of the study also provides a perspective on how geography is not just a physical structure but also a significant factor in understanding human mobility and interaction in cross-border contexts.
16

Urban design quality, neighbourhood urban form and travel behaviour: case studies of four Adelaide suburbs

Soltani, Ali January 2007 (has links)
This thesis presents the results from a comparative study of travel patterns among residents of four suburban residential areas in metropolitan Adelaide. Using existing datasets together with inventory data of urban environment characteristics from original fieldwork, this research examines to what extent there are associations between various attributes of a particular urban location as they relate to travel behaviour and household socio-economics. The findings derived from quantitative and qualitative methods suggest that urban form/design must be taken into consideration in policy making for mobility reduction.
17

Estudos de relações entre variáveis socioeconômicas, de uso do solo, participação em atividades e padrões de viagens encadeadas urbanas / Study of relationships between socioeconomic, land use, activity participation variables and trip-chaining urban patterns

Pitombo, Cira Souza 27 April 2007 (has links)
Um dos tópicos mais importantes na análise de demanda por transportes é a relação entre as necessidades individuais de realização de atividades geograficamente distribuídas, a estrutura urbana, as características individuais e domiciliares, o sistema de transporte e as diferenças no comportamento relacionado a viagens. Isto motivou o desenvolvimento desta pesquisa, que tem como objetivo principal analisar o comportamento individual subjacente ao encadeamento de viagens sob a perspectiva de três grupos de variáveis: (1) participação em atividades; (2) características socioeconômicas; e (3) uso do solo. Há dois objetivos secundários, fundamentais para se atingir a finalidade do trabalho: (a) propor um conjunto de variáveis de uso do solo; e (b) testar a significância do grupo de variáveis ora proposto. Este trabalho baseou-se nos dados da pesquisa origem-destino de 1997 da região metropolitana de São Paulo, sendo extraídas e analisadas seis amostras finais que foram caracterizadas por setor econômico (no caso de trabalhadores) e grau de instrução (no caso de estudantes). Com utilização conjunta de técnicas de análise multivariadas, confirmatórias e exploratórias, foi possível representar a variável dependente (Análise de Cluster), bem como encontrar relações entre variáveis envolvidas (Árvore de Decisão) e, finalmente, mensurar a significância estatística das variáveis independentes (Regressão Linear Múltipla). Através dos resultados obtidos, foi possível analisar a influência dos três grupos de variáveis na seqüência de viagens: (1) variáveis socioeconômicas (renda familiar, usa vale transporte, nº provável de carteiras de habilitação no domicílio, idade, nº de automóveis no domicílio) afetam principalmente a seqüência de modos de transporte utilizados durante as viagens; (2) participação em atividades (estuda, trabalha) interfere na seqüência de motivos de viagem; e, enfim, (3) variáveis de uso do solo (parcela acumulada de empregos ou escolas por faixas de distância a partir do centróide da zona de residência) influenciam a seqüência de destinos escolhidos. Espera-se que o presente trabalho constitua uma contribuição ao meio acadêmico, tanto em termos de representação da intensidade e distribuição geográfica das atividades no meio urbano (variáveis de uso do solo), quanto em relação à influência de tais variáveis nos deslocamentos dos indivíduos. / One of the most important topics in transportation demand is the relationship between individual needs to carry out geographically distributed activities, urban configuration, individual and household characteristics, transportation system and travel behavior. For that reason, the main aim of this work is to analyze the individual trip-chaining behavior in terms of three variables groups: (1) activity participation; (2) socioeconomic characteristics; and (3) land use. There are also two secondary objectives derived from the main objective: (a) to propose one set of land use variables; and (b) to verify the statistical significance of the created land use group variables. This work was based on the origin-destination survey carried out in the São Paulo metropolitan area in 1997, from which six final samples were extracted, analyzed and characterized by economic sector (for workers) and level of education (for students). Applying multivariate analysis techniques, confirmatory and exploratory, it was possible to represent the dependent variable (Cluster Analysis), as well as to find relationships between the concerned variables (Decision Tree) and, finally, to measure the statistical significance of the independent variables (Multiple Regression). From the results, it was possible to analyze the influence of the three variables groups on trip-chaining: (1) socioeconomic variables (household income, transit voucher use, probable number of driver licenses per household, age, car-ownership) affect the travel mode sequence used for the trips; (2) activity participation (study, work) has an effect on the trip purpose sequence; and (3) land use variables (accumulated proportion of jobs or schools by distance buffers starting from the residence zone centroid) influence the sequence of chosen destinations. It is expected that the present work could be a contribution to the scientific community for the representation of the activities level and their geographic distribution in the urban configuration (land use variables), and the influence of such variables on individuals displacements.
18

Estudos de relações entre variáveis socioeconômicas, de uso do solo, participação em atividades e padrões de viagens encadeadas urbanas / Study of relationships between socioeconomic, land use, activity participation variables and trip-chaining urban patterns

Cira Souza Pitombo 27 April 2007 (has links)
Um dos tópicos mais importantes na análise de demanda por transportes é a relação entre as necessidades individuais de realização de atividades geograficamente distribuídas, a estrutura urbana, as características individuais e domiciliares, o sistema de transporte e as diferenças no comportamento relacionado a viagens. Isto motivou o desenvolvimento desta pesquisa, que tem como objetivo principal analisar o comportamento individual subjacente ao encadeamento de viagens sob a perspectiva de três grupos de variáveis: (1) participação em atividades; (2) características socioeconômicas; e (3) uso do solo. Há dois objetivos secundários, fundamentais para se atingir a finalidade do trabalho: (a) propor um conjunto de variáveis de uso do solo; e (b) testar a significância do grupo de variáveis ora proposto. Este trabalho baseou-se nos dados da pesquisa origem-destino de 1997 da região metropolitana de São Paulo, sendo extraídas e analisadas seis amostras finais que foram caracterizadas por setor econômico (no caso de trabalhadores) e grau de instrução (no caso de estudantes). Com utilização conjunta de técnicas de análise multivariadas, confirmatórias e exploratórias, foi possível representar a variável dependente (Análise de Cluster), bem como encontrar relações entre variáveis envolvidas (Árvore de Decisão) e, finalmente, mensurar a significância estatística das variáveis independentes (Regressão Linear Múltipla). Através dos resultados obtidos, foi possível analisar a influência dos três grupos de variáveis na seqüência de viagens: (1) variáveis socioeconômicas (renda familiar, usa vale transporte, nº provável de carteiras de habilitação no domicílio, idade, nº de automóveis no domicílio) afetam principalmente a seqüência de modos de transporte utilizados durante as viagens; (2) participação em atividades (estuda, trabalha) interfere na seqüência de motivos de viagem; e, enfim, (3) variáveis de uso do solo (parcela acumulada de empregos ou escolas por faixas de distância a partir do centróide da zona de residência) influenciam a seqüência de destinos escolhidos. Espera-se que o presente trabalho constitua uma contribuição ao meio acadêmico, tanto em termos de representação da intensidade e distribuição geográfica das atividades no meio urbano (variáveis de uso do solo), quanto em relação à influência de tais variáveis nos deslocamentos dos indivíduos. / One of the most important topics in transportation demand is the relationship between individual needs to carry out geographically distributed activities, urban configuration, individual and household characteristics, transportation system and travel behavior. For that reason, the main aim of this work is to analyze the individual trip-chaining behavior in terms of three variables groups: (1) activity participation; (2) socioeconomic characteristics; and (3) land use. There are also two secondary objectives derived from the main objective: (a) to propose one set of land use variables; and (b) to verify the statistical significance of the created land use group variables. This work was based on the origin-destination survey carried out in the São Paulo metropolitan area in 1997, from which six final samples were extracted, analyzed and characterized by economic sector (for workers) and level of education (for students). Applying multivariate analysis techniques, confirmatory and exploratory, it was possible to represent the dependent variable (Cluster Analysis), as well as to find relationships between the concerned variables (Decision Tree) and, finally, to measure the statistical significance of the independent variables (Multiple Regression). From the results, it was possible to analyze the influence of the three variables groups on trip-chaining: (1) socioeconomic variables (household income, transit voucher use, probable number of driver licenses per household, age, car-ownership) affect the travel mode sequence used for the trips; (2) activity participation (study, work) has an effect on the trip purpose sequence; and (3) land use variables (accumulated proportion of jobs or schools by distance buffers starting from the residence zone centroid) influence the sequence of chosen destinations. It is expected that the present work could be a contribution to the scientific community for the representation of the activities level and their geographic distribution in the urban configuration (land use variables), and the influence of such variables on individuals displacements.
19

Redução no tamanho da amostra de pesquisas de entrevistas domiciliares para planejamento de transportes: uma verificação preliminar / Reduction in sample size of household interview research for transportation planning: a preliminary check

Aguiar, Marcelo Figueiredo Massulo 11 August 2005 (has links)
O trabalho tem por principal objetivo verificar, preliminarmente, a possibilidade de reduzir a quantidade de indivíduos na amostra de Pesquisa de Entrevistas Domiciliares, sem prejudicar a qualidade e representatividade da mesma. Analisar a influência das características espaciais e de uso de solo da área urbana constitui o objetivo intermediário. Para ambos os objetivos, a principal ferramenta utilizada foi o minerador de dados denominado Árvore de Decisão e Classificação contido no software S-Plus 6.1, que encontra as relações entre as características socioeconômicas dos indivíduos, as características espaciais e de uso de solo da área urbana e os padrões de viagens encadeadas. Os padrões de viagens foram codificados em termos de sequência cronológica de: motivos, modos, durações de viagem e períodos do dia em que as viagens ocorrem. As análises foram baseadas nos dados da Pesquisa de Entrevistas Domiciliares realizada pela Agência de Cooperação Internacional do Japão e Governo do Estado do Pará em 2000 na Região Metropolitana de Belém. Para se atingir o objetivo intermediário o método consistiu em analisar, através da Árvore de Decisão e Classificação, a influência da variável categórica Macrozona, que representa as características espaciais e de uso de solo da área urbana, nos padrões de viagens encadeadas realizados pelos indivíduos. Para o objetivo principal, o método consistiu em escolher, aleatoriamente, sub-amostras contendo 25% de pessoas da amostra final e verificar, através do Processamento de Árvores de Decisão e Classificação e do teste estatístico Kolmogorov - Smirnov, se os modelos obtidos a partir das amostras reduzidas conseguem ilustrar bem a freqüência de ocorrência dos padrões de viagens das pessoas da amostra final. Concluiu-se que as características espaciais e de uso de solo influenciam os padrões de encadeamento de viagens, e portanto foram incluídas como variáveis preditoras também nos modelos obtidos a partir das sub-amostras. A conclusão principal foi a não rejeição da hipótese de que é possível reduzir o tamanho da amostra de pesquisas domiciliares para fins de estudo do encadeamento de viagens. Entretanto ainda são necessárias muitas outras verificações antes de aceitar esta conclusão. / The main aim of this work is to verify, the possibility of reducing the sample size in home-interview surveys, without being detrimental to the quality and representation. The sub aim of this work is to analyze the influence of spatial characteristics and land use of an urban area. For both aims, the main analyses tool used was Data Miner called the Decision and Classification Tree which is in the software S-Plus 6.1. The Data Miner finds relations between trip chaining patterns and individual socioeconomic characteristics, spatial characteristics and land use patterns. The trip chaining patterns were coded in terms of chronological sequence of trip purpose, travel mode, travel time and the period of day in which travel occurs. The analyses were based on home-interview surveys carried out in the Belém Metropolitan Area in 2000, by Japan International Cooperation Agency and Pará State Government. In order to achieve the sub aim of this work, the method consisted of analyzing, using the Decision and Classification Tree, the influence of the categorical variable \"Macrozona\", which represents spatial characteristics and urban land use patterns, in trip chaining patterns carried by the individuals. Concerning the main aim, the method consisted of choosing sub-samples randomly containing 25% of the final sample of individuals and verifying (using Decision and Classification Tree and Kolmogorov-Smirnov statistical test) whether the models obtained from the reduced samples can describe the frequency of the occurrence of the individuals trip chaining patterns in the final sample well. The first conclusion is that spatial characteristics and land use of the urban area have influenced the trip chaining patterns, and therefore they were also included as independent variables in the models obtained from the sub-samples. The main conclusion was the non-rejection of the hypothesis that it is possible to reduce the sample size in home-interview surveys used for trip-chaining research. Nevertheless, several other verifications are necessary before accepting this conclusion.
20

Redes neurais artificiais aplicadas na modelagem individual de padrões de viagens encadeadas a pé / Artificial neural networks applied in individual modeling of trip-chaining patterns by walk

Gonzales Taco, Pastor Willy 25 July 2003 (has links)
O objetivo deste trabalho foi desenvolver um modelo para reconhecer e reproduzir padrões de viagens encadeadas a pé. O processo de modelagem foi conduzido através da aplicação das técnicas das Redes Neurais Artificiais (RNAs), utilizando-se de uma rede estática MLP e de rede dinâmica Elman. A análise do desempenho do modelo foi baseada nos dados de uma pesquisa de Origem-Destino realizada, em 1987, pelo METRÔ-SP na Região Metropolitana de São Paulo. Na modelagem foi fixado o modo de viagem a pé, e, na abordagem seqüencial, padrões de viagens individuais foram representados em termos de dois componentes: duração da viagem e tipo de atividades. A análise foi realizada partindo da classificação geral e específica para cada segmento do encadeamento de viagens, o que permitiu a comparação dos resultados entre padrões de viagens observados e os reproduzidos pelas redes. Na classificação geral, cinco dos padrões previstos com maior freqüência pelas RNAs representaram em média 58,9% dos indivíduos no conjunto de dados usado para testar o desempenho do modelo. Para o vetor de duas e quatro viagens, as redes neurais reproduziram 50% das durações de viagem e 90% das atividades, tais como Trabalho e Escola. Embora esses resultados não pareçam muito robustos, não significa que eles estejam errados. As porcentagens acima representam a probabilidade de uma pessoa realizar viagens com aquelas durações ou tipo de atividades. / The main objective of this work was to develop a model for recognizing and reproduzing trip-chaining patterns by walk. The process of modeling was conducted applying the techniques of Artificial Neural Networks (ANNs), by using one of the static networks MLP and the Elman dynamic network. The analysis of the performance of the model was based on the origin-destination home-interview survey carried out by METRÔ-SP in São Paulo Metropolitan Area in 1987. The mode of trip by walk was fixed in the model, and, in the sequential approach, individual travel patterns were represented in terms of two components: trip duration and activity type. The analysis was accomplished starting from the general and specific classifications for each segment of the chained trips, which allowed the comparison of the results between the observed travel patterns and reproduced ones through ANNs. In general classification, 5 of the patterns most frequently predicted by the ANNs represented 58.9% of the individuals in the dataset used for testing the model performance. For the vectors of two and four trips, the neural networks reproduced 50% of trip durations and 90% of the activities, such as work and school. Although those results seem not so robust, it does not mean that they are wrong. The percentages above represent the probability of a person making trips with those durations or type of activities.

Page generated in 0.0587 seconds