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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.
181

An analysis of transport policy in Hong Kong: the case of the public light buses

Leung, Sik-huen., 梁錫壎. January 1981 (has links)
published_or_final_version / Public Administration / Master / Master of Social Sciences
182

[en] VOLTAGE STABILITY ASSESSMENT CONSIDERING PRIMARY FREQUENCY CONTROL AND FREQUENCY-DEPENDENT LINE PARAMETERS / [pt] AVALIAÇÃO DAS CONDIÇÕES DE ESTABILIDADE DE TENSÃO CONSIDERANDO A REGULAÇÃO PRIMÁRIA E PARÂMETROS DA REDE VARIÁVEIS COM A FREQUÊNCIA

DIANA MARGARITA GARCIA MARTINEZ 05 January 2016 (has links)
[pt] A crescente demanda de energia elétrica faz com que a complexidade dos sistemas elétricos de potência seja cada vez maior, associado às limitações na expansão do sistema de transmissão, resulta na operação dos sistemas elétricos mais próximos de seus limites, tornando-os vulneráveis a problemas de estabilidade de tensão. Nesse contexto, faz-se necessário o desenvolvimento de ferramentas computacionais capazes de representar os sistemas elétricos mais adequadamente, melhorando assim as condições de análise. Neste trabalho são apresentadas três modelagens do fluxo de carga mais completas que a modelagem clássica, a saber: a modelagem de múltiplas barras swing, a modelagem com regulação primária e a modelagem com parâmetros da rede de transmissão variáveis com a frequência. Uma vez utilizadas na solução do problema do fluxo de carga estas modelagens são estendidas para a realização do cálculo dos índices de estabilidade de tensão das barras de carga, barras de tensão controlada e barras swing. Testes numéricos com um sistema-teste de 6 barras são apresentados para a verificação da aplicabilidade e adequação dos modelos analisados. / [en] The growing demand for electricity increases the complexity of electric power systems which, when combined with limitations in the expansion of transmission systems, results in the operation of electrical systems closer to their limits, making them vulnerable to voltage stability problems. In this context, there is a gap in the market for the development of computational tools that can represent the electrical systems more appropriately, thereby improving the conditions of analysis. The present study formulates three non-classical load flow representations: multiple swing buses, primary frequency control, and frequency dependent transmission network parameters. Once used in the load flow problem solving, these models are also extended to allow the calculation of voltage stability indices of load buses, controlled voltage buses and swing buses. Numerical tests with a 6-bus test system are presented to verify the applicability and adequacy of the proposed models.
183

[en] A VISUAL ANALYSIS OF BUS GPS DATA IN RIO / [pt] UMA ANÁLISE VISUAL DOS DADOS DE GPS DOS ÔNIBUS NO RIO

BRUNO GUBERFAIN DO AMARAL 19 July 2016 (has links)
[pt] O tema Cidades Inteligentes é um assunto de interesse para gestores públicos e pesquisadores. Desenvolver cidades mais inteligentes é um dos desafios para o futuro próximo devido à crescente demanda por serviços públicos. Em particular, o transporte público é um dos aspectos mais visíveis de uma cidade viva e, portanto, a sua implementação deve ser muito eficiente. O sistema de transporte público da cidade do Rio de Janeiro é historicamente deficiente, principalmente porque ele é baseado em um antigo sistema de ônibus. Para melhorá-lo, a Prefeitura tomou algumas ações, como o desenvolvimento de um projeto de dados aberto que mostra, a quase a cada minuto, a posição instantânea de todos os ônibus na cidade. Embora não seja uma nova tecnologia, esta é a primeira iniciativa a ser desenvolvida no Rio. Neste trabalho, são aprsentadas ferramentas simples para a exploração visual deste grande conjunto de dados com base em informações históricas, que chega a um total de mais de um bilhão de amostras. Com essas ferramentas, um usuário será capaz de verificar as tendências, identificar padrões e localizar anomalias nesta grande quantidade de dados de GPS dos ônibus. / [en] Smart cities is a current subject of interest for public administrators and researchers. Getting the cities smarter is one of the challenges for the near future, due to the growing demand for public services. In particular, public transportation is one of most visible aspects of a living city and, therefore, its implementation must be very efficient. The public transportation system of the City of Rio de Janeiro is historically deficient, mostly because it is based on an old bus system. To change it, the City Hall took some actions, such as the development of an open data project that shows, at about every minute, the GPS instant position of all buses in the city. Although it is not a new technology, it is the first initiative to be developed in Rio. This work presents simple tools for the visual exploration of this big dataset based on the historical information from this service, which reaches a total of more than one billion samples. With these tools one is able to discover trends, identify patterns, and locate abnormalities within the massive collection of the buses GPS data.
184

Självkörande elbussar - Framtidens miljölösning

Tauberman, Klas, Olausson, Pontus January 2018 (has links)
Enligt (Regeringskansliet, 2017a) ska nettoutsläppen från Sveriges växthusgaser år 2045 inte påverka atmosfären vartefter Sveriges utsläpp ska bli negativa, vilket innebär att det används mer koldioxid än vad som släpps ut. För att uppnå klimatmålen kommer det krävas många nya lösningar i samhället. En allt mer drivande transportsektor med mer bilar på vägarna och fler parkeringsplatser är inte hållbart för framtida svensk trafik och arbetet mot klimatmålen. Att avlägsna oljedrivna fordon från transportsektorn skulle bidra till ett renare och mer attraktivt stadsklimat.   Studien syftar till att ta reda på hur en implementering av elektrisk-, även självkörande kollektivtrafik i Varberg ser ut, energimässigt, miljömässigt och ekonomiskt för tre stycken upplagda scenarier. I studien ingår även att undersöka ifall övertoner kan komma att inverka på elnätet. Projektet som är ett samarbete med Varberg Energi har uppkommit i samband med planeringen av det nya stadsområdet Västerport. I scenarierna finns tre olika bussar: en dieselbuss som återfinns i Varberg idag, en generell elbuss samt en självkörande elbuss som kallas Navya.   Den mängd passagerare som ska transporteras och vilken miljöpåverkan bussarna ger har stor inverkan på slutsatsen i rapporten. Med en svensk fossilfri bussflotta år 2020 visar denna rapport att Navyan är primärt rekommenderad upp till 15 personer och därefter är elbussen sekundärt rekommenderad. Implementering av elbussar är fullt möjlig och gör ingen betydande inverkan på det befintliga elnätet idag. / According to (Regeringskansliet, 2017a) Sweden’s greenhouse gas emissions shall not affect the atmosphere by the year 2045, which then becomes negative, this means that more carbon dioxide will be consumed rather than released into the atmosphere. In order to reach the climate goals, many new solutions to the society are required. A bigger transport sector with more cars and parking spaces is not sustainable for neither the future transport sector, nor the progressive work toward the climate goals. By removing oil-operated vehicles from the streets, a significant contribution to a cleaner city climate would be achieved.   The study aims to find out if an implementation of electric buses is possible in Varberg. A couple of key questions are raised: how much energy is required to support the buses? What are the costs of the various scenarios proposed? Will there be any problems with supporting many buses, in terms of harmonics and the electric power grid? The project, which is a cooperation with Varberg Energi, is proposing a realization of a new city area called Västerport, which would start construction 2020. The report constitutes three scenarios with a diesel bus, which is used in Varberg today, an electric bus and an autonomous electric minibus called Navya.   The number of passengers to be transported and the environmental effect of the buses has a big impact on the conclusion of the report. With a fossil free bus fleet by 2020, this report shows that the Navya is primarily recommended up to 15 passengers, and the electric bus for more passengers. The report concludes that the implementation of electric buses is possible. It will not have a considerable impact on the existing power grid and will contribute to a cleaner and more attractive city.
185

Emissões do transporte urbano : da quantificação à mitigação

Arioli, Magdala Satt January 2014 (has links)
Uma das principais externalidades dos transportes na dimensão urbana é a emissão de poluentes locais e a geração de gases de efeito estufa (GEE). O estudo tem por finalidade quantificar as emissões da frota de ônibus urbano de uma cidade brasileira e propor um mecanismo de mitigação de GEE. Para atingir o objetivo, o estudo apresenta os combustíveis e tecnologias disponíveis no Brasil, e através de uma meta-análise identifica as combinações de combustível e tecnologia que proporcionam a maior redução das emissões de CO, HC, NOx, MP e CO2e. Os resultados da análise mostram que algumas das opções de combustível e tecnologia que apresentam melhor desempenho são: B100 associado ao DPF e SCR, GNV associado ao 3WC, B20 associado ao DPF e SCR, e D15 associado ao DPF e SCR. A seguir, as contribuições dos mecanismos de mitigação de GEE para o setor de transportes são analisadas. O impacto do Mecanismo de Desenvolvimento Limpo (MDL) no setor é limitado, e não há muitas perspectivas de atuação. As Ações de Mitigação Nacionalmente Apropriadas (NAMAs), têm potencial para atuar na redução de GEE, e devem proporcionar apoio financeiro oriundo dos fundos climáticos para as ações implantadas nos países em desenvolvimento. Um estudo de caso foi desenvolvido para avaliar a possibilidade de elaboração de uma NAMA para a renovação da frota de ônibus urbano de uma cidade. Os resultados obtidos na meta-análise foram aplicados para avaliar o combustível e tecnologia que proporcionam maior redução das emissões. Os resultados mostram que a renovação da frota tem potencial de desenvolvimento de uma NAMA, visto que reduz emissões de GEE e proporciona co-benefícios; contudo, deve-se estabelecer um sistema de MRV (Monitorar, Reportar, Verificar) capaz de quantificar as emissões na mitigação. / One of the main externalities from urban transportation is the emission of local pollutants and greenhouse gases (GHG). The study aims to quantify the emissions from the urban bus fleet of a Brazilian city and propose a GHG mitigation mechanism. First, the study presents the fuels and technologies available in Brazil, and through a meta-analysis identifies combinations of fuel and technology that provide the greatest reduction in emissions of CO, HC, NOx, PM and CO2e. Results show the fuel and technology that perform best are: B100 associated with DPF and SCR, CNG associated with 3WC, B20 associated with DPF and SCR, and D15 associated with DPF and SCR. The contribution of GHG mitigation mechanisms for the transport sector was analyzed. The impact of the Clean Development Mechanism (CDM) in the sector is limited, and there are not many perspectives for the future. The Nationally Appropriate Mitigation Actions, named NAMAs, have the potential to act in reducing GHG in transport sector, and should provide financial cooperation through climate funds for implementation of actions in developing countries. A case study was developed to evaluate the possibility of developing a NAMA for the renewal of the fleet of urban buses in a Brazilian city. The results obtained in the meta-analysis were applied to evaluate which fuel and technology provide greater reductions in emission. The results show that the renewal of the fleet has the potential for developing a NAMA, since it reduces greenhouse gas emissions and provide co-benefits; however it requires a serious MRV (Monitor, Report, Verify) capable of quantifying the mitigation of emissions.
186

En öde ö som flyter runt : en kvalitativ studie av hur mobila och stationära förskolepedagoger uppfattar de organisatoriska förutsättningarna för att hantera en dubbel enhet / A deserted island floating around : a qualitative study about how mobile and stationary preschool pedagogues perceive the organizational condition for managing a dual unit

Wickholm, Jennie January 2017 (has links)
The purpose of this study is to examine how mobile and stationary pedagogues experience the cooperation between the two units and how the pedagogues perceive the organizational conditions for managing a dual unit. Furthermore is the study also examine whether there are any different perceptions of working methods in each other's activities and if this has an impact on the children at preschool. In order to be able to answer these questions, I have chosen to make qualitative interviews at two different stationary preschools and two different mobile units/buses. I have interviewed four pedagogues, two from stationary units and two from mobile units. In my study I can see patterns in that bus pedagogues perceive themselves as be an ”own preschool” or ”own island” where they express "take care" of themselves. Nor do they perceive that they need to adapt to what’s happening on the preschool, for example, in case of illness. But they have a need to belong to the "house" when it comes to getting help during planning times. The stationary pedagogues perceive as the bus pedagogues do not see the entire preschool as a common organization that the bus pedagogues only cares for their own needs. The stationary pedagogues perceive that the mobile pedagogues exclude themselves but the mobile pedagogues perceive that they get excluded. The result of this study points that management should be aware of the strong impact of previous traditions and approaches in a working group or individual. Without clear leadership, too much space is given to the pedagogues own "profit-making" purposes, which can have an impact on the children's opportunities and to become in the preschool environment.
187

Emissões do transporte urbano : da quantificação à mitigação

Arioli, Magdala Satt January 2014 (has links)
Uma das principais externalidades dos transportes na dimensão urbana é a emissão de poluentes locais e a geração de gases de efeito estufa (GEE). O estudo tem por finalidade quantificar as emissões da frota de ônibus urbano de uma cidade brasileira e propor um mecanismo de mitigação de GEE. Para atingir o objetivo, o estudo apresenta os combustíveis e tecnologias disponíveis no Brasil, e através de uma meta-análise identifica as combinações de combustível e tecnologia que proporcionam a maior redução das emissões de CO, HC, NOx, MP e CO2e. Os resultados da análise mostram que algumas das opções de combustível e tecnologia que apresentam melhor desempenho são: B100 associado ao DPF e SCR, GNV associado ao 3WC, B20 associado ao DPF e SCR, e D15 associado ao DPF e SCR. A seguir, as contribuições dos mecanismos de mitigação de GEE para o setor de transportes são analisadas. O impacto do Mecanismo de Desenvolvimento Limpo (MDL) no setor é limitado, e não há muitas perspectivas de atuação. As Ações de Mitigação Nacionalmente Apropriadas (NAMAs), têm potencial para atuar na redução de GEE, e devem proporcionar apoio financeiro oriundo dos fundos climáticos para as ações implantadas nos países em desenvolvimento. Um estudo de caso foi desenvolvido para avaliar a possibilidade de elaboração de uma NAMA para a renovação da frota de ônibus urbano de uma cidade. Os resultados obtidos na meta-análise foram aplicados para avaliar o combustível e tecnologia que proporcionam maior redução das emissões. Os resultados mostram que a renovação da frota tem potencial de desenvolvimento de uma NAMA, visto que reduz emissões de GEE e proporciona co-benefícios; contudo, deve-se estabelecer um sistema de MRV (Monitorar, Reportar, Verificar) capaz de quantificar as emissões na mitigação. / One of the main externalities from urban transportation is the emission of local pollutants and greenhouse gases (GHG). The study aims to quantify the emissions from the urban bus fleet of a Brazilian city and propose a GHG mitigation mechanism. First, the study presents the fuels and technologies available in Brazil, and through a meta-analysis identifies combinations of fuel and technology that provide the greatest reduction in emissions of CO, HC, NOx, PM and CO2e. Results show the fuel and technology that perform best are: B100 associated with DPF and SCR, CNG associated with 3WC, B20 associated with DPF and SCR, and D15 associated with DPF and SCR. The contribution of GHG mitigation mechanisms for the transport sector was analyzed. The impact of the Clean Development Mechanism (CDM) in the sector is limited, and there are not many perspectives for the future. The Nationally Appropriate Mitigation Actions, named NAMAs, have the potential to act in reducing GHG in transport sector, and should provide financial cooperation through climate funds for implementation of actions in developing countries. A case study was developed to evaluate the possibility of developing a NAMA for the renewal of the fleet of urban buses in a Brazilian city. The results obtained in the meta-analysis were applied to evaluate which fuel and technology provide greater reductions in emission. The results show that the renewal of the fleet has the potential for developing a NAMA, since it reduces greenhouse gas emissions and provide co-benefits; however it requires a serious MRV (Monitor, Report, Verify) capable of quantifying the mitigation of emissions.
188

Mockup einer Betriebsleitstelle für automatisierte Shuttlebusse - Konzeption und Design eines universellen, visuellen und auditiven Interfaces

Franke, Ingmar S., Beckmann, Sönke, Biletska, Olga, Zadek, Hartmut 07 September 2021 (has links)
Derzeit sind automatisierte Shuttlebusse beim Einsatz auf einen Operator an Bord angewiesen. Damit sich dies nicht erst beim vollständig autonomen Fahren ändert, bedarf es weiterer Lösungsansätze. Eine Möglichkeit ist die Überwachung der Busse aus einer Betriebsleitstelle. Allerdings können mit den Betriebsleitstellen von Verkehrsgesellschaften nach heutigem technologischem Stand keine Fahrfunktionen übernommen werden. Um diese Forschungslücke zu schließen, wurde im Rahmen dieses Beitrags ein Mockup für eine Betriebsleitstelle von automatisierten Shuttlebussen entwickelt. Das Hauptaugenmerk bei der Konzeption dieses Interfaces liegt in der Anforderungsanalyse. Zu diesem Zweck wurden Experten aus Wirtschaft und Wissenschaft eingebunden. Als Ergebnis ist ein Mockup mit einer interaktiven Karte, einer Ereignisliste und einer Ansicht zur Übernahme der Fahrfunktionen entstanden.
189

Barns perspektiv på framtidens resor med autonom buss / Children’s perspective on future travels by autonomous bus

Larsson, Kristina January 2021 (has links)
Barns mobilitet och möjlighet att på egen hand ta sig runt i staden har minskat och begränsas idag i stor utsträckning av otrygga trafiksituationer. I och med sin begränsade oberoende mobilitet exkluderas barn från stadsrummet och dess faciliteter. Oberoende mobilitet kan relateras till flera dimensioner av barns sociala, fysiska, psykiska och kognitiva välmående. Syftet med studien är att undersöka om och på vilket sätt autonoma bussar kan bidra till barns oberoende mobilitet och med hjälp av barns upplevelser och erfarenheter bidra med insikter i detta inför införandet av autonoma bussar i städer och kollektivtrafiksystem. För att göra det besvaras frågeställningarna “Hur kan autonoma bussar i transportsystemet bidra till barns oberoende mobilitet?” och “Vilka förutsättningar är nödvändiga för att autonoma bussar ska bidra till barns oberoende mobilitet?”. Undersökningen utgår från ett fall av införande av autonoma bussar i stadsmiljö och för att besvara frågeställningarna genomfördes med elever på en grundskola fokusgrupper med syfte att inhämta deltagarnas upplevelser och erfarenheter. Resultatet tyder på att införandet av autonoma bussar i ett urbant område kan bidra till barns oberoende mobilitet på flera sätt och att bussarna har vissa egenskaper som gör att de kan anpassas till barns förutsättningar. Insikter från studien kan bidra till en förståelse för hur, från barns eget perspektiv, oberoende mobilitet kan gynnas av autonoma bussar i kollektivtrafiken, samt hur tjänsten behöver utvecklas för att anpassas till denna användargrupp när autonoma bussar i större utsträckning ska implementeras i staden. / Children's mobility and the opportunity to get around the city on their own has decreased and is today limited to a large extent by unsafe traffic situations. Due to their limited independent mobility, children are excluded from the urban space and its facilities. Independent mobility can be related to several dimensions of children's social, physical, mental and cognitive wellbeing. The purpose of the study is to investigate if and in what way autonomous buses can contribute to children's independent mobility and, using children's experiences, provide insights into this before the introduction of autonomous buses in cities and public transport systems. To do so, the two research questions "How can autonomous buses in the transport system contribute to children's independent mobility?"and "What prerequisites are necessary for autonomous buses to contribute to children's independent mobility?" are answered. The survey is based on a case of introduction of autonomous buses in urban environments and to answer the questions three focus groups with students in a primary school were conducted with the aim of gaining the participants' experiences. The results indicate that the introduction of autonomous buses in an urban area can contribute to children's independent mobility in several ways and that the buses have certain characteristics that enable them to be adapted to children's conditions. Insights from the study can contribute to an understanding of in what way, from children's own perspective, independent mobility can benefit from autonomous buses in public transport, and how the service needs to be developed to adapt to this user group when autonomous buses are to be implemented to a greater extent in the city.
190

Analýza ztráty zisku dopravní organizace v důsledku opravy po nehodě u autobusů s obsaditelností nad 30 míst / Analysis of Profit Loss for a Transport Organization as a Result of Repair Work After an Accident Involving Buses with a Carrying Capacity of over 30 Passengers

Pitaš, Martin January 2011 (has links)
The main aim of this master's thesis is preparation of economic and technical data for analysis of profit loss for a transport organization as a result of repair work after an accident involving buses with a carrying capacity of over 30 passengers. Master's thesis has three main parts. First part deals with technical data of buses SOR C 9,5, SOR C 10,5 a MAN Lion's Regio C, theirs equipment and service operation. Economic data about these buses are processed and evaluated in second part. Last part is devoted to the creation of methodology for calculation of profit loss of buses after an accident. It concerns about each model and category of buses with a carrying capacity of over 30 passengers as a whole.

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