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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.
161

A percepção da inovação em chassis de ônibus rodoviários sob as óticas de clientes e usuários do sistema brasileiro de transporte

Stival, Idam Lauren January 2009 (has links)
Esta pesquisa trata da percepção da inovação por parte dos usuários e clientes no mercado rodoviário brasileiro de transporte de pessoas, mais especificamente das tecnologias e inovações presentes nos chassis de ônibus rodoviário. Recentemente, este setor sofreu forte transformação voltando-se à simplificação de ceículos e componentes e a uma consequentemente redução das inovações e tecnologias utilizadas nos veículos. O objetivo geral desta pesquisa foi identificar os aspectos ligados à percepção da inovação em chassis de ônibus rodoviários sob as óticas de clientes e usuários finais do sistema de transporte. Esta pesquisa tembém identificou quais fatores presentes nos ônibus rodoviários foram apontados como significativos sob a ótica dos usuários e quais inovações e tecnologias são conhecidas da maioria dos passageiros. Este trabalho também identificou quais fatores levam as empresas de transporte rodoviário adquirir determinados modelos de chassis em detrimento a outros mais especificados, com maior número de tecnologias e inovações embarcadas. Para a realização desta pesquisa foi adotado o procedimento de documentação direta de uma situação de mercado, com a coleta de dados realizada junto a 159 usuários - passageiros - de transporte rodoviário de passageiros, mais especificamente aqueles que utilizam a cidade de Curitiba como rota para seus itinerários de viagem. Também foram entrevistados 28 clientes pertencentes a 20 empresas do sistema de transporte, definidos nesta pesquisa como empresas de transporte rodoviário de pessoas e as empresas que fabricam a carroçaria dos ônibus rodoviários. Como resultado, a pesquisa disgnosticou a falta de percepção de inovação e a consequente indiferença por parte dos usuários no momento de escolher uma empresa ou veículo de transporte para viajar. Com relação às empresas de transporte de passageiros foi identificada uma forte tendência à aquisição de veículos que ofereçam tão somente um custo atrativo. Por mais que os clientes de chassis de ônibus identifiquem e reconheçam os benefícios de algumas inovações e tecnologias disponíveis no setor, o fator custo é determinante para a quisição da frota na maioria das empresas. Essa estratégia adotada pode, inclusive, ter sido responsável pelo recente aumento no número de acidentes envolvendo ônibus rodoviários nas estradas brasileiras. / This research becomes to the innovation perception of users - passengers - and clients - people transportation companies and bodybuilder companies - within Brazilian transportation market, specifically technologies an innovations applied in the coaches. Recently this field has suffered a hard change becoming to low end vehicles and components. As consequence this market presents a reduction of innovations and technologies applied in the coaches. The main research achievement was to identify by lens of clients and passengers of Brazilian transportation sytem the aspects relative to innovation perception at coach chassis. This research has identified which faactors or features embodied in the vehicles were appointed as strongly significant according to passenger vision and also which sort of innovations are recognized by them. The research also identified the factors that lead the transport companies to acquire some simplified chassis instead of other ones with technologies and innovations embarked. The research accomplishment required adopts a methodology based ondirect market documentation. Its data acquisition was done with 159 passengers of Brazilian road transporte system; specifically those are using the Curitiba city bus station as part of trip journey. Also were interviewed 28 clients from 20 companies of transportation system, which are defined as companies of passengers transport, as well as, body builder factories. As expected results the research showed the complete lack of awareness and insensibility regarding to users when they are choosing a bus or company to travel. However, result identified by passenger transportation companies shows a strong trend to acquire products based on low end attractiveness or appeal. No matter how much the coach clients have been identified and even recognized some innovations and technologies benefits available in this market, the cost issue is determining factor to fleet acquisition in the majority of the companies. Thiss strategy adopted by passenger transport companies could contribute for the recent raise of accidents involving coaches at Brazilizn roads. / 5000-11-25
162

Autonomous Bus Passenger Experience

Lundquist, Martin January 2018 (has links)
Time keeps on changing our perception of what is possible in our personal life and around us. Over time, jobs such as elevator operator was essential to make the elevator keep its speed, stop parallel to the floor and keep passengers safe in case of emergency. Nowadays elevator passengers just have to enter their destination and wait to be transported there. An operator would be superfluous for this, today, simple procedure. This paper aims to create a set of interaction strategies to provide an efficient and pleasurable journey for the passenger traveling with an autonomous bus, as well as evaluate concepts where these strategies have been applied. The strategies and concepts will be developed from an extensive user- and literature research where the situation of today will be analysed and looked upon with the eyes of tomorrow, to find challenges and needs. Findings shows that passengers have to trust the vehicle and service. At the same time vehicle and service providers have to provide a reliable and consistent service. Four design directions were created to establish this trust between the user and vehicle and service. To enable control and give passengers an efficient journey, passengers have to be provided with adequate and reliable information. The information regarding the bus’s behaviour should be communicated in a transparent way so the bus’s intentions and actions are understandable from a passenger point of view. Also, passengers have to be enabled to stay safe when using the bus, during commuting and emergency, through giving them cues in how an emergency should be handled.
163

Desenvolvimento de ciclos de teste para banco de provas representativos da condução de ônibus urbanos da cidade de São Paulo. / Development of test bench cycles representative of actual driving patterms of transit buses in São Paulo city.

Leonardo de Oliveira Costa 03 April 2018 (has links)
Em vigência desde Janeiro de 2012, a regulamentação Proconve P7 para veículos comerciais pesados exige que a demonstração de emissões de poluentes do motor seja realizada no ciclo de teste transiente europeu (ETC), desenvolvido de acordo com perfil de condução tipicamente europeu e assim pouco representativo de diversas situações de tráfego no Brasil. Especialmente quanto a aplicações de ônibus urbanos, altamente dinâmicas e submetidas a perfis de baixa velocidade e média carga, não é possível correlacionar plenamente o funcionamento do motor e seus sistemas de controle de emissões baseando-se apenas neste ciclo. Com essa motivação, o principal objetivo deste estudo é desenvolver ciclos de teste compactos para banco de provas de chassis e de motores que representem as condições reais de condução de ônibus urbanos da cidade de São Paulo. Estes ciclos de teste específicos possibilitam avaliações mais precisas não apenas das emissões de poluentes, mas também do consumo de combustível, além de proporcionarem melhor compreensão do real desempenho de motores e novas tecnologias dos sistemas de propulsão usados em frotas de ônibus urbanos no Brasil. A metodologia aplicada para construção dos ciclos utiliza o conceito de potência específica veicular (VSP), variável que apresenta alta correlação com emissões de poluentes e consumo de combustível e é calculada a partir de dados coletados em condições reais de condução de ônibus (velocidade, aceleração e inclinação das vias). A seleção dos veículos e linhas para realização das aquisições de dados considera tanto as especificações de trem-de-força e de chassis disponíveis na frota, como também os índices operacionais e a topografia dos trajetos como métodos para determinação de linhas com perfil operacional mais representativo. Como resultado do estudo foram propostos cinco ciclos de teste, um para cada tipo de ônibus selecionado (miniônibus, midiônibus, básico, padron e articulado), e as análises comparativas com o ciclo ETC quanto ao comportamento do motor mostram claramente a falta de representatividade do ciclo europeu adotado pela regulamentação brasileira. / Since January 2012, the Proconve P7 regulation is mandatory for heavy duty commercial vehicles requiring that the demonstration of pollutant gases emissions must be carried out by submitting the engine to the European transient test cycle (ETC), which has been developed according to European driving patterns and therefore is not representative of several driving situations in Brazil. Particularly for driving patterns of urban buses, which are highly dynamic with low vehicle speed and medium load profiles, it is not possible to fully correlate the operating conditions of the engine and its emission control systems based only on this test cycle. With this motivation, the main objective of this study is to develop compact test cycles for use in both chassis and engine test benches that represent the actual driving pattern of transit buses in São Paulo city. These specific test cycles may allow more accurate assessment of pollutant gases emissions and fuel consumption, as well as provide a better understanding concerning the real performance of engines and new propulsion technologies used in urban bus fleets in Brazil. The methodology used for construction of the cycles is based on the concept of vehicle specific power (VSP), a variable that is highly correlated with pollutant emissions and fuel consumption and is calculated from data collected under real-world driving conditions (vehicle speed, acceleration and road grade). The selection of the buses and routes for the on-board data collection considers the specifications of powertrain and chassis that are available in the bus fleet of São Paulo\'s public transportation system, operational indexes and route topography as a method for determining the bus routes with a more representative operational pattern. As the result of this study five test cycles were proposed, one for each bus type (minibus, midibus, basic, padron and articulated), and an analysis of the engine\'s operating behavior in comparison to the ETC cycle clearly shows the lack of representativeness of the European cycle adopted by the Brazilian regulation.
164

An analysis of non-white transport requirements in an Eastern Cape urban area

Viljoen, John January 1978 (has links)
From Preface: The following research is centred around the Grahamstown non-white urban transportation problem. The bus service under consideration is owned and operated by the Grahamstown Municipality and is attached to the City Fire Department. It caters only for non-white commuters by operating fourteen buses, which carry approximately 1 200 000 people per year. As such, the difficulties encountered by this transport service should be generally, though not entirely, applicable only to relatively small non-white transport undertakings. The aims of this research are threefold: 1. to establish the environment within which transport undertakings operate, the structure of the undertaking in response to this environment and the problems which such undertakings encounter in their daily operations ; 2. by analysing in detail a specific transport service, an attempt has been made to delineate problem areas in both the cost and revenue structures, and to ascertain the degree of management awareness of the existence of these problems ; and 3. to determine the social impact of this transport operation and to evaluate all aspects of the service in relation to commuters, business and social needs and wants. Unfortunately, an attempt to extend this type of research to further Eastern Cape urban areas was unsuccessful due to the refusal by certain transport undertakings and government bodies to provide essential information.
165

Investigating end-user acceptance of autonomous electric buses to accelerate diffusion

Herrenkind, Bernd, Brendel, Alfred Benedikt, Nastjuk, Ilja, Greve, Maike, Kolbe, Lutz M. 08 September 2021 (has links)
To achieve the widespread diffusion of autonomous electric buses (AEBs) and thus harness their environmental potential, a broad acceptance of new technology-based mobility concepts must be fostered. Still, there remains little known about the factors determining their acceptance, especially in the combination of vehicles with alternative fuels and autonomous driving modes, as is the case with AEBs. In this study, we first conducted qualitative research to identify relevant factors influencing individual acceptance of autonomously driven electric buses. We then developed a comprehensive research model that was validated through a survey of 268 passengers of an AEB, operated in regular road traffic in Germany. The results indicate that a mix of individual factors, social impacts, and system characteristics determine an individual’s acceptance of AEBs. Notably, it is important that users perceive AEBs, not only as advantageous, but also trustworthy, enjoyable, and in a positive social light. Our research supplements the existing corpora by demonstrating the importance of individual acceptance and incorporating it to derive policy implications.
166

Vyhodnocovaní komplexních situací z údajů letecké avioniky / Evaluation of complex situations from airplane’s avionics

Vysloužil, Ondřej January 2009 (has links)
Tento projekt se podrobně zaměřuje na data z avioniky a může být chápán jako horní vrstva nad systémy monitorujícími poruchy, která poskytuje dodatečné informace o letu. Pro konkrétní návrh byly vybrány Airbus A320 a A340 jako zástupci moderních a rozšířených dopravních letadel. Vyvíjená aplikace analyzuje dvě vybrané komplexní situace z toku dat palubní avioniky a hledá podmínky, které vedou k abnormálnímu chování letadla (nikoliv poruchám). Práce je primárně zaměřena na letové fáze, strukturu dat (a jejich kategorizaci) a na vývoj aplikace na bázi fuzzy systému s expertní znalostí uloženou v jeho pravidlech.
167

Fossilfri kollektivtrafik : En företags- och samhällsekonomisk kostnadsjämförelse av förnybara drivmedel för stadsbussar i Uppsala utifrån tre skattescenarier / Fossil free public transport : A socio-economic and business administration cost comparison of renewable fuels for city buses in Uppsala based on three tax scenarios

Nordström, Eeva-Liisa January 2015 (has links)
No description available.
168

The South Africa-Zimbabwe remittance corridor: an analysis of its characteristics and the cost of remittance payments

Onyango, Beryl Morine Achieng' 08 March 2022 (has links)
Zimbabwean migrants in South Africa often send financial support to their relatives in Zimbabwe. This financial support is known as remittances and is sent as cash or in-kind. This study investigated the characteristics of the South African-Zimbabwe remittance corridor. A critical investigation of the remittance channels used, the type of remittances sent, and the remittance transaction costs involved was done. Data for use in this study was collected through interviews with remittance service providers and by actual remittance transfers to Zimbabwe. A qualitative and quantitative analysis of data using statistical analysis techniques was done. From the analyzed data, it was observed that remittance service providers fall into two channels: formal and informal. The informal remittance channels were found to be the most popular in this corridor. The popularity of informal channels can be attributed to lower transaction costs and a lack of documentation needed from the sender. Informal remittance channels do not require the remittance sender to provide any identification document, therefore, undocumented Zimbabwean migrants opt for them. Long-distance buses that serve the South Africa-Zimbabwe route were found to be a popular channel of sending remittances - both cash and in-kind - to Zimbabwe. In-kind remittances have gained popularity due to the perennial lack of household consumer goods in Zimbabwe. Due to the national lockdown imposed in South Africa as a response to the Covid19 global pandemic, the study was unable to find the volume of remittances that is sent through the informal longdistance buses and trucks. The lockdown resulted in the closure of borders and non-essential travel was not permitted. The study found that the remittance transaction cost in the South AfricaZimbabwe corridor was higher than the global average cost of 6.84% (for formal channels) and the United Nations Sustainable Development Goal of 3% by the year 2030.
169

Bus Replacement Modeling and the Impacts of Budget Constraints, Fleet Cost Variability, and Market Changes on Fleet Costs and Optimal Bus Replacement Age, A Case Study

Boudart, Jesse Alexander 01 January 2011 (has links)
Overwhelming evidence throughout the literature has shown that bus overhead and maintenance (O&M) costs increase as buses age. This has implications toward a fleet manager's decision of when one should buy, use, or sell buses to minimize total fleet costs. Unfortunately, there are uncertain market conditions associated with bus fleets that cloud the manager's ability to make appropriate decisions. Using integer programming (IP), O&M trends and changing market conditions are integrated into a model to better analyze bus fleets. Due to recent budget constraints of transit agencies, needs for a bus fleet replacement model have arisen. King County in Washington State has supplied cost aggregated data of their New Flyer (NF) and NF hybrid buses. These data have been analyzed to create statistical relationships based on rising O&M costs per mile with age, which are then integrated with the IP model to determine the impact of changing diesel prices, potential carbon dioxide (CO2) emissions costs, uncertain maintenance costs, and bus purchase cost subsidies. The goal is to aid fleet managers to determine the costs of early or delayed suboptimal bus replacement timing and the impacts of market variability on fleet costs and optimal replacement timing. The optimal replacement age for NF and NF hybrid buses based on King County data and current fuel prices of $3.99/gal are 16.7 and 18.3 years, respectively. It has been consistently observed that greater expense is incurred when buses are replaced earlier rather than later from optimal. To minimize total CO2 emissions (including operation and construction emissions), buses should be replaced slightly before the optimal replacement time without considering CO2 emissions. High diesel prices and CO2 emissions had little or no effect, on when buses should be replaced. However, higher maintenance costs reduced the optimal replacement time by almost two years. Although NF hybrid buses have been found to have no economic advantage over conventional buses, this finding may be a consequence of the different costs associated to the different routes operated by hybrid and conventional buses. Due to the lack of detailed King County's route level historical data, a study of the economic competitiveness of NF hybrids against conventional buses is outside the scope of this thesis. If buses are used less with age, the optimal replacement age is reduced. The optimal replacement age also dropped significantly when the Federal Transit Agency's procurement assistance is applied into the model. The procurement assistance can be up to 80% of the capital costs and can be considered a purchase subsidy from the transit agency viewpoint. If purchase subsidies decrease bus purchase prices by 1%, the optimal replacement age drops approximately 1.5%. When the bus purchase price is reduced by 80%, the optimal bus replacement age is less than 12 years, the FTA's minimum replacement age.
170

Transition Towards Fixed-Line Autonomous Bus Transportation Systems

Hatzenbühler, Jonas January 2020 (has links)
In the last years the steady development of autonomous driving technology has enabled the deployment of more mature autonomous vehicles. These vehicles have been applied in several pilot projects worldwide, most commonly in the form of small buses. At the same time, the amount of people traveling in especially urban areas is continuously growing, resulting in more trips in the transportation system. An efficient transportation system is therefore required to serve the growing passenger demand. Autonomous buses (AB) are assumed to have lower operational costs and with that public transport (PT) systems can potentially be designed more efficiently to facilitate the increased demand better. In this study, an AB specific simulation-based optimization framework is proposed which allows analyzing the impacts AB have on line-based PT systems. The thesis focuses on the transition from existing PT systems towards line-based PT systems operated partially or exclusively by AB. Existing work on PT service design is extended so that realistic AB systems can be investigated. This is achieved by (i) using AB specific operator cost formulations, (ii) integrating infrastructure costs required for AB operations, (iii) utilizing a dynamic, stochastic and schedule-based passenger assignment model for the simulation of PT networks and by (iv) formulating a multi-objective optimization problem allowing to investigate the stakeholder-specific impacts of AB. In Paper I the effects of AB, concerning service frequency and vehicle capacity, on fixed-line PT networks are investigated. Among other metrics, the changes are evaluated based on differences in level of service and passenger flow. Additionally, the sequential introduction of AB in existing PT systems is studied. The framework addresses a case study in Kista, Sweden. The study confirmed the initial hypothesis that the deployment of AB leads to an increase in service frequency and a marginal reduction in vehicle capacity. Furthermore, it could be seen that the deployment of AB increases the passenger load on AB lines and that passengers can shift from other PT modes towards the AB services. Paper II incorporates a multi-objective heuristic optimization algorithm in the simulation framework. The study investigates changes in transport network design based on the deployment of AB. The differences in user-focused and operator-focused network design are analyzed and the impact of AB on these is quantified. This study is applied to a case study in Barkarby, Sweden where a full-sized, line-based PT network is designed to exclusively operate AB. Among other findings, we show that the autonomous technology reduces the number of served bus stops and reduces the total PT network size. Additionally, average passenger waiting time can be reduced when deploying AB on user-focused PT networks, which in turn leads to a further reduction of user cost. / De senaste årens framsteg inom autonom körteknik har lett till mer mogna autonoma fordon. Dessa fordon har setts tillämpas i flera pilotprojekt över hela världen, oftast i form av små bussar. Samtidigt växer mängden människor som reser, särskilt i stadsområden, kontinuerligt vilket resulterar i fler resor i transportsystemet. Därför krävs ett effektivt transportsystem för att tillgodose det växande antalet passagerare. Autonoma bussar (AB) antas ha lägre driftskostnader och därmed kan system för kollektivtrafik (public transport, PT) potentiellt utformas mer effektivt för att underlätta den ökade efterfrågan bättre. I denna studie föreslås ett AB-specifikt simuleringsbaserat optimeringsramverk som gör det möjligt att analysera effekterna AB har på linjebaserade PT-system. Avhandlingen fokuserar på övergången från befintliga PT-system till linjebaserade PT-system som delvis eller uteslutande drivs av AB. Befintligt arbete med PT-tjänstdesign utvidgas så att realistiska AB-system kan undersökas. Detta uppnås genom att (i) använda AB-specifika operatörskostnadsformuleringar, (ii) integrera infrastrukturkostnader som krävs för AB-verksamhet, (iii) använda en dynamisk, stokastisk och schemabaserad modell för att tilldela passagerare vid simulering av PT-nät samt genom att (iv) formulera ett multifunktionellt optimeringsproblem som gör det möjligt att undersöka AB: s intressespecifika effekter. I artikel I undersöks effekterna av AB, med avseende på servicefrekvens och fordonskapacitet, på fasta linjer i PT-nät. Förändringar utvärderas bland annat utifrån skillnader i servicenivå och passagerarflöde. Dessutom studeras den sekventiella introduktionen av AB i befintliga PT-system. Det föreslagna ramverket tillämpas på en fallstudie i Kista, Sverige. Studien bekräftade den initiala hypotesen att utplaceringen av AB leder till en ökning av servicefrekvensen och en marginell minskning av fordonens kapacitet. Vidare kunde man se att utplaceringen av AB ökar passagerarbelastningen på AB-linjer och att passagerare kan skifta från andra PT-former mot AB-tjänsterna. Artikel II integrerar en multifunktionell heuristisk optimeringsalgoritm i ramverket för simuleringen. Studien undersöker förändringar i transportnätverkets design baserat på implementeringen av AB. Skillnaderna i användarfokuserad och operatörsfokuserad nätverksdesign analyseras och AB: s inverkan på dessa kvantifieras. Denna studie tillämpas på en fallstudie i Barkarby, Sverige, där ett fullstort linjebaserat PT-nät är utformat för att exklusivt driva AB. Vi visar bland annat att den autonoma tekniken reducerar antalet använda busshållplatser och reducerar den totala PT-nätstorleken. Dessutom kan implementeringen av AB på användarfokuserade PT-nät ytterligare förbättra servicenivån främst genom att minska den genomsnittliga väntetiden per passagerare.

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