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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.
391

A prática educativa e o estudo do meio: o Amapá como estudo de caso na construção do conceito de sustentabilidade / The educational practice and the field project: Amapá as a case study in the construction of the concept of sustainability

Fernandes, Maria Lidia Bueno 12 March 2009 (has links)
O presente trabalho apresenta um estudo do meio sobre o tema desenvolvimento sustentável que teve trabalho de campo em maio de 2001 no Estado do Amapá para analisar a implantação do Programa de Desenvolvimento Sustentável daquele Estado. Nasceu a partir de uma proposta do currículo de Geografia e envolveu alunos e alunas do 3º ano do Ensino Médio de uma escola privada da cidade de São Paulo. O objetivo desta tese é analisar a metodologia do estudo do meio na construção de uma aprendizagem significativa para alunos e alunas envolvidos no processo, com base nos Parâmetros Curriculares Nacionais e em teóricos como Pontuschka, Bittencourt e Castellar. Discorre sobre o processo de aquisição do espírito científico, a partir da utilização do método dialético. Discute a concepção de ensino/aprendizagem tendo como base Vigotsky a partir dos conceitos de Zona de Desenvolvimento Proximal e do caráter Interacionista de uma prática educativa escolar. Fundamenta-se em teóricos como Zabala, Coll e Solé no que diz respeito ao papel do professor, à aquisição de conteúdos conceituais, procedimentais e atitudinais e à adoção de um enfoque globalizador, entendido como sinônimo de interdisciplinaridade. Aborda importantes temas da Geografia tais como: Diversidade Cultural, Amazônia, Segregação Espacial, Paisagem, Território, Meio Ambiente, Desenvolvimento Sustentável, entre outros. Trata-se de pesquisa qualitativa, realizada a partir da metodologia de análise documental, considerando a produção dos alunos e alunas registrada nos cadernos de campo, diários de viagem, em entrevistas concedidas a periódicos no Amapá, nos testemunhos para o site da escola e nas monografias elaboradas. / This thesis presents a field project on sustainable Development. The objective of the field trip, which took place in May 2001 in the state of Amapá, was to examine the implementation of the Program for Sustainable Development in the State. The project involved students who study in a private school in the city of Sao Paulo and who were in their final year at high school. The aim of this thesis is to examine the methodology of field work to create a meaningful learning experience for students involved in the process based on the National Curriculum Parameters and theorists such as Pontuschka, Bittencourt and Castellar. The thesis examines the process of acquiring scientific spirit through the use of a dialectical method. It discusses the design of teaching / learning based on Vigotskys concepts of Zone of Proximal Development and on the integrationist character of an educative scholarly practice. It is based on theorists such as Zabala, Coll and Solé with regard to the role of teacher, the acquisition of conceptual, procedural and attitudinal content and to the adoption of a globalizing focus, regarded as synonymous with interdisciplinary focus. This is qualitative research, which was achieved through the methodology of documentary analysis. It took into consideration the production of students registrations in their field notebooks, their travel diaries, interviews held and testimony given to the school web site and monographs.
392

Técnicas de sensoriamento remoto para identificação de áreas de concentração de polos geradores de viagens. / Remote sensing techniques to the identification of the concentration áreas of trip generators hubs.

Machado, Cláudia Aparecida Soares 06 June 2013 (has links)
O objetivo desta Tese é a proposição de uma metodologia alternativa para planejamento de transportes que contempla as ferramentas disponíveis na ciência do sensoriamento remoto. A perspectiva adotada analisa aspectos do planejamento de transportes urbanos, tendo como embasamento os dados e informações advindos das imagens de satélite com alto poder de resolução espacial. A metodologia usa a abordagem baseada em objetos para classificar imagens de satélite de sensoriamento remoto. Através do processo de classificação, identificam-se feições urbanas úteis para o planejamento de transporte, em especial áreas de concentração de polos geradores de viagens do município de João Pessoa no estado da Paraíba, Brasil. A proposta é que com base nesses dados, e outros provenientes de uma pesquisa de campo (pesquisa domiciliar origem/destino), é possível caracterizar o uso do solo e a correspondente demanda por transportes. O estudo se justifica por propor uma alternativa mais ágil e menos onerosa, em comparação aos métodos tradicionais de construção e atualização da base de dados para análises de transportes. Ao identificar as regiões da cidade com as maiores quantidades de viagens geradas, os resultados obtidos auxiliam nas ações de planejamento do sistema de transportes, visando alcançar o equilíbrio entre oferta e demanda de transporte com o uso do solo urbano. / The objective of this Thesis is to propose an alternative method of transportation planning that considers the tools available in the science of remote sensing. The perspective adopted examines aspects of urban transportation planning, having as basis the data and information coming from satellite images with high spatial resolution. The methodology uses the object-based approach to classify remote sensing satellite imagery. Through the classification process, urban features useful for transportation planning are identified, mainly areas of concentration of trip generation in the city of João Pessoa, state of Paraíba, Brazil. The proposal is that, based on these data, and others from a field research (origin/destination home-interview survey), it is possible to characterize the land use and the corresponding demand for transport. The study is justified because it proposes a more agile and less costly alternative, compared to traditional methods of building and updating the database for transport analysis. By identifying areas of the city with the largest amounts of trips generated, the results support planning actions on the transportation system, in order to achieve a balance between transport supply and demand with urban land use.
393

Kopplungen am Arbeitsort

Köhler, Hadia Sabine 17 May 2013 (has links)
In dieser Arbeit werden außerberufliche Tätigkeiten von Erwerbstätigen in ihrem Arbeitsortumfeld untersucht. Es wird erforscht, welche Aktivitäten Erwerbstätige dort koppeln. Als Einflussfaktoren werden die funktional-räumliche Ausstattung des Arbeitsortumfeldes, deren Wahrnehmung und Bewertung durch die Erwerbstätigen und Merkmale der beruflichen Tätigkeit, Verkehrsmittelwahl und soziodemographische Merkmale betrachtet. Nahmobilität im Arbeitsortumfeld wurde bislang in Deutschland noch nicht explizit untersucht. Damit wurden bisher aus theoretischer Sicht ein bedeutsamer Pol des Aktionsraumes von Personen sowie ein wesentlicher Ansatzpunkt zur planerischen Stärkung der Nahmobilität bzw. der Umsetzung des Leitbildes der Stadt der kurzen Wege vernachlässigt. Eine quantitative Befragung von Angehörigen der Humboldt-Universität zu Berlin (N = 565) zeigte die Bedeutung des Arbeitsortumfeldes für die Alltagsorganisation in den Bereichen Freizeit, Dienstleistungen und Einzelhandel auf. Zur Beschreibung des Kopplungsverhaltens dienen die Begriffe „Nutzerakzeptanz“, „objektives Nutzungsspektrum“ und „subjektives Nutzungsspektrum“. Es üben 96 % der Personen Aktivitäten im Arbeitsortumfeld aus (Nutzerakzeptanz). Sie konzentrieren ihre Nutzung meist auf wenige Gelegenheiten aus dem Spektrum aller vorhandenen Gelegenheiten (objektives Nutzungsspektrum). Neu eingeführt wird in der vorliegenden Studie das subjektive Nutzungsspektrum als Anteil der genutzten an den subjektiv bekannten Angeboten im Arbeitsortumfeld. Im Vergleich zum objektiven ist das subjektive Nutzungsspektrum deutlich größer. Es konnte ein deutlicher Zusammenhang der Nutzung von Angeboten im Arbeitsortumfeld mit der Stadtstruktur, mit der Verkehrsmittelwahl und mit soziodemographischen Merkmalen der Befragten aufgezeigt werden. Der Zusammenhang des Nutzungsverhaltens mit Merkmalen der Erwerbstätigkeit ist hingegen nicht eindeutig interpretierbar. / The present work investigates what non-work activities are trip chained by employees nearby their places of work. As influencing factors the facility mix close to the places of work, its perception and evaluation, occupational characteristics, mode of transport, and sociodemographic factors are taken into account. So far, in (German) research there is a strong tendency to focus on the residential area end of the trip when exploring short-distance mobility patterns. Thus, research left an important part of action space unattended and disregarded an aspect of land use that might be susceptible to successful planning control in order to promote short-distance mobility patterns. A quantitative survey among members of Humboldt-Universität zu Berlin (N = 565) revealed the importance of the proximity of the place of work for non-work activities in the fields of recreation, services and shopping. The utilisation of facilities is described by the terms “acceptance of facilities by users” (1; “Nutzerakzeptanz”), “objectively used share of facilities” (2; “objektives Nutzungsspektrum”) and “subjectively used share of facilities” (3; “subjektives Nutzungsspektrum”). 96 % of the respondents carry out activities nearby their place of work (1). In doing so, most people concentrate only on a few facilities out of the whole range of facilities offered (2). A new aspect in the present work is the focus on the “subjectively used share of facilities” which describes the portion of used facilities of all facilities known to a person. In comparison to the “objectively used share of facilities” the “subjectively used share of facilities” is bigger. An interrelationship of the utilisation of facilities with facility mix, perception and evaluation of the facilities, choice of transport mode, and sociodemographic characteristics, respectively, was found. The interrelation between the utilization of facilities and occupational characteristics is less clear.
394

Uma proposta de carregamento incremental de fluxos veiculares para a estimação de matriz O-D sintética / A proposal for incremental loading in traffic flows for synthetic O-D matrix estimation

Bertoncini, Bruno Vieira 08 March 2007 (has links)
Neste trabalho é proposto um método de carregamento incremental dos fluxos veiculares para a estimação de matriz O-D sintética. A principal motivação para o desenvolvimento deste trabalho está na complexidade dos métodos de estimação de matriz sintética pelo método iterativo, que tem conduzido a resultados não satisfatórios. O método de carregamento incremental, ora proposto neste trabalho, pode ser definido como o inverso do método de alocação incremental de viagens aos arcos de uma rede viária. A matriz O-D obtida com este método é o resultado da soma sucessiva das sub-matrizes estimadas através das parcelas dos fluxos observados nos arcos da rede. Este método pode ser aplicado em qualquer tipo de rede viária: congestionada ou não congestionada e com ou sem continuidade de fluxo. Para verificação do desempenho do método foram realizados testes experimentais, nos quais os resultados obtidos foram comparados com os valores observados. O desempenho do método incremental não se mostrou satisfatório. Assim, com o intuito de verificar a sua utilidade como um método alternativo os mesmos dados foram processados através de dois métodos iterativos. Os resultados mostraram que os erros são ainda maiores do que os obtidos pelo método proposto. A principal conclusão deste trabalho é que o método incremental pode ser usado como uma alternativa aos métodos iterativos. / A synthetic O-D matrix estimation method, based on incremental loading of traffic flow, was proposed in this work. This research was motivated because of the complexity of the iterative methods for synthetic matrix estimation that might produce bias accumulation in the results. The referred incremental loading method could be defined as the inverse of the incremental assignment method for trips to links of a traffic network. The O-D matrix is gathered by successively summing the sub-matrices obtained from parts of the traffic flow counted on the links of the traffic network. This method could be applied to any traffic networks: congested or uncongested and with or without volumetric continuity. As a part of verification proceeding, several experimental tests were carried out to evaluate the method performance. In these tests the estimated results were compared with the real values. These results show that the incremental loading method performance was not satisfactory. Thus, aiming to test the utility of the incremental method, a second round of experimental tests was conducted to evaluate two iterative methods. In these second round tests, the results show that theses methods performance was worse those of the incremental method. The main conclusion of this work is that the incremental loading method for synthetic matrices estimation could be used as an alternative to the iterative methods.
395

Uma proposta de carregamento incremental de fluxos veiculares para a estimação de matriz O-D sintética / A proposal for incremental loading in traffic flows for synthetic O-D matrix estimation

Bruno Vieira Bertoncini 08 March 2007 (has links)
Neste trabalho é proposto um método de carregamento incremental dos fluxos veiculares para a estimação de matriz O-D sintética. A principal motivação para o desenvolvimento deste trabalho está na complexidade dos métodos de estimação de matriz sintética pelo método iterativo, que tem conduzido a resultados não satisfatórios. O método de carregamento incremental, ora proposto neste trabalho, pode ser definido como o inverso do método de alocação incremental de viagens aos arcos de uma rede viária. A matriz O-D obtida com este método é o resultado da soma sucessiva das sub-matrizes estimadas através das parcelas dos fluxos observados nos arcos da rede. Este método pode ser aplicado em qualquer tipo de rede viária: congestionada ou não congestionada e com ou sem continuidade de fluxo. Para verificação do desempenho do método foram realizados testes experimentais, nos quais os resultados obtidos foram comparados com os valores observados. O desempenho do método incremental não se mostrou satisfatório. Assim, com o intuito de verificar a sua utilidade como um método alternativo os mesmos dados foram processados através de dois métodos iterativos. Os resultados mostraram que os erros são ainda maiores do que os obtidos pelo método proposto. A principal conclusão deste trabalho é que o método incremental pode ser usado como uma alternativa aos métodos iterativos. / A synthetic O-D matrix estimation method, based on incremental loading of traffic flow, was proposed in this work. This research was motivated because of the complexity of the iterative methods for synthetic matrix estimation that might produce bias accumulation in the results. The referred incremental loading method could be defined as the inverse of the incremental assignment method for trips to links of a traffic network. The O-D matrix is gathered by successively summing the sub-matrices obtained from parts of the traffic flow counted on the links of the traffic network. This method could be applied to any traffic networks: congested or uncongested and with or without volumetric continuity. As a part of verification proceeding, several experimental tests were carried out to evaluate the method performance. In these tests the estimated results were compared with the real values. These results show that the incremental loading method performance was not satisfactory. Thus, aiming to test the utility of the incremental method, a second round of experimental tests was conducted to evaluate two iterative methods. In these second round tests, the results show that theses methods performance was worse those of the incremental method. The main conclusion of this work is that the incremental loading method for synthetic matrices estimation could be used as an alternative to the iterative methods.
396

Effectiveness of a Speed Advisory Traffic Signal System for Conventional and Automated vehicles in a Smart City

Anany, Hossam January 2019 (has links)
This thesis project investigates the state-of-the-art in traffic management "Green Light Optimal Speed Advisory (GLOSA)" for vehicles in a smart city. GLOSA utilizes infrastructure and vehicles communication through using current signal plan settings and updated vehicular information in order to influence the intersection approach speeds. The project involves traffic microscopic simulations for a mixed traffic environment of conventional and automated vehicles (AVs) both connected to the intersection control and guided by a speed advisory traffic management system. Among the project goals is to assess the effects on traffic performance when human drivers comply to the speed advice. The GLOSA management approach is accessed for its potential to improve traffic efficiency in a full market penetration of connected AVs with absolute compliance. The project also aims to determine the possible outcome resulting from enhancing the AVs capabilities such as implementing short time headways between vehicles in the future.  The best traffic performance results achieved by operating GLOSA goes for connected AVs with the lowest simulated time headway (0.3 sec). The waiting time reduction reaches 95% and trip delay lessens to 88 %.
397

Spot Welding of Advanced High Strength Steels (AHSS)

Khan, Mohammad Ibraheem 20 April 2007 (has links)
Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced. The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone. Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.
398

Spot Welding of Advanced High Strength Steels (AHSS)

Khan, Mohammad Ibraheem 20 April 2007 (has links)
Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced. The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone. Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.
399

The impact of Stellenbosch Square on retail buying patterns in Paradyskloof

Van der Merwe, J. M. P. 12 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2006. / The retail sector provides geographers with a major area of analysis where they can apply their specialist knowledge to solve and explain real-world problems. Over the years there have been significant changes in the locations where South Africans shop. Retail shops are moving from city centres (CBDs) to more accessible and attractive locations on the city’s edge. This phenomenon is also evident in the retail structure of Stellenbosch. Stellenbosch Square is a multi-million-rand shopping centre that has been erected on the edge of Stellenbosch. The retail buying patterns of the Paradyskloof neighbourhood (in Stellenbosch) was analysed and placed in context with Stellenbosch Square. Paradyskloof is situated between Stellenbosch Square and Die Boord shopping centre, which is situated more closely to the CBD. The null hypothesis states that: “The buying patterns of the residents of Paradyskloof did not change significantly after the building of Stellenbosch Square, a shopping centre situated between Stellenbosch and the Somerset West shopping centre.” The overarching aim is to describe and explain the extent of the current retail buying patterns of the Paradyskloof population and compare them to the predicted results of the Flowmap 7.2 origin-constrained gravity model with regards to Stellenbosch Square shopping centre. The Paradyskloof retail buying patterns was determined by a random distributed questionnare survey. The modelled results are compared to the actual buying patterns and the findings are placed in context. Various types of data (primary and secondary) were collected. The origin-constrained gravity model was calibrated with the mean trip lengths (MTL). The modelled results predicted that all of the Paradyskloof residents shop at Stellenbosch Square. To determine the actual buying patterns, 250 questionnaires were spatially distributed with the aid of a random sampling of erven within the Paradyskloof neighbourhood. The survey indicated that only 44% of the respondents shop at Stellenbosch Square. Some of the reasons for why some of the residents still shop closer to the CBD are: high mobility, high number of scholars, multi-functional trips, banking and postal services etc. The rationale behind Stellenbosch Square and the role it plays within the Stellenbosch retail market has also been provided.
400

Influence de la transformation martensitique induite par la déformation sur le comportement mécanique d’aciers inoxydables duplex / Influence of strain induced martensitic transformation on the mechanical behavior of duplex stainless steels

Lechartier, Audrey 15 December 2015 (has links)
Les aciers inoxydables duplex présentent une combinaison intéressante entre des propriétés mécaniques élevées, une faible conductivité thermique et un coût relativement faible. Ils sont couramment employés dans le domaine du bâtiment comme rond à béton, application qui requière notamment une résistance élevée (Rm > 950 MPa) et une ductilité importante (A% > 15). Cette thèse a pour objectif d’améliorer le compromis résistance / allongement, en développant de nouvelles nuances duplex présentant une transformation martensitique induite par la plasticité (effet TRIP) aux caractéristiques contrôlées. L’optimisation de ce compromis a nécessité en particulier une compréhension détaillée des mécanismes de transformation et de déformation plastique associés à chaque phase : la ferrite (BCC), l’austénite (FCC) et la martensite (BCC).L’influence de la transformation martensitique sur le comportement mécanique est étudiée pour quatre alliages duplex de stabilité variable de la phase austénitique en fonction de leur composition chimique. L’influence d’une microstructure multiphasée sur la cinétique de transformation est déterminée grâce à l’élaboration de trois nuances modèles représentant respectivement une nuance duplex et es deux compositions représentatives de ses constituants austénite et ferrite. L’utilisation de plusieurs techniques de caractérisation à différentes échelles a permis de décrire à la fois les mécanismes de transformation de phase et leur cinétique en fonction de la déformation, donnant ainsi accès à leur influence sur le comportement mécanique. L’étude des champs cinématiques a mis en évidence l’impact de la phase martensitique sur la répartition des déformations dans la microstructure multi-phasée. Finalement l’utilisation d’un modèle mécanique prenant en compte explicitement la transformation martensitique a permis de reproduire le comportement mécanique d’un alliage duplex. / Duplex stainless steels offer an attractive combination of high mechanical properties, low thermalconductivity and a relatively low cost. They are increasingly used as structural materials such as inthe construction sector as concrete reinforcement bars, where both high strength (Rm > 900 MPa)and high elongation to failure (A% > 15 %) are required. This thesis aims at improving the strength/ elongation compromise by developing new duplex stainless steel compositions experiencing a wellcontrolledmartensitic transformation induced by plasticity (TRIP effect). The optimisation of thiscompromise has required a good understanding of the transformation mechanisms and of plasticdeformation associated with each phase : ferrite (BCC), austenite (FCC) and martensite (BCC).The influence of martensitic transformation on mechanical behavior has been studied in four duplexgrades of variable austenite stability as a function of their chemical composition. The influence ofmultiphase microstructure on martensitic transformation kinetics has been determined by makingthree alloys respectively representative of a duplex grade and its two constituents (austenite andferrite). Using multiple characterization techniques at different scales has allowed determiningboth the transformation mechanisms and its kinetics as a function of strain, giving thus accessto the influence of transformation on the mechanical behavior. The study of kinematic fields hashighlighted the impact of the martensitic phase on the distribution of deformations. Finally, theuse of a mechanical model taking explicitly into account the phase transformation has allowed theduplication of the mechanical behavior of a duplex stainless steel.

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