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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.
1

Redefining Horizons: A Study on Business Model Innovation for the Commercialization of Services within Urban Air Mobility / Nya Horisonter: Affärsmodellssinnovation för Kommersialiseringen av Tjänster inom Uraban Air Mobility

Landberg, Otto, Blomgren, Jacob January 2023 (has links)
Urban air mobility has gained increased attention in recent years due to the emergence of novel technologies. Several use cases within different industries exist. These services can substitute existing services as well as offering entirely new ones. Previous research has focused on novel technologies and changes needed to be made in order for the technology to be established in the market. However, non-technological aspects are lacking, specifically concerning suitable business models. Thus, the role of business models, and changes related to these, required for a commercialization of urban air mobility services constitutes a research gap and are of interest for further exploration. To understand how actors are changing their business models to commercialize urban air mobility three different case studies were conducted on three projects focusing on use cases connected to urban air mobility. Interviews were used as the primary data gathering method, and in total 13 were conducted. The theoretical STOF framework, which delimits the business model into four domains, was used to identify potential changes. The main results indicate important future actors in a commercialization, the degree of change of these actors and potential challenges for them. Due to the uncertainty of the role business models play in a commercialization of urban air mobility services, this thesis will contribute to bridging this research gap. Concrete changes are identified, as well as specific business model areas in need of more attention. Furthermore, the thesis contributes to the literature concerning challenges related to urban air mobility services, as well as suggesting how they can be handled. Finally, the thesis evaluates and explains how the STOF framework can be extended to new industries. / Urban air mobility har fått ökad uppmärksamhet de senaste åren på grund av uppkomsten av nya teknologier. Flera användningsområden inom olika branscher existerar. Dessa tjänster kan ersätta befintliga tjänster samt erbjuda helt nya. Tidigare forskning har främst fokuserat på nya teknologier och förändringar som behöver göras för att tekniken ska etableras på marknaden. Emellertid saknas aspekter som inte är teknologiska, särskilt lämpliga affärsmodeller. Därmed är inte affärsmodellens roll samt nödvändiga förändringar relaterade till den för en kommersialisering av urban air mobility tillräckligt belysta och är därför intressant för vidare forskning. För att förstå hur aktörer ändrar sina affärsmodeller för att kommersialisera urban air mobility genomfördes tre olika fallstudier på tre projekt som fokuserar på användningsområden kopplade till urban air mobility. Den teoretiska STOF modellen, som avgränsar affärsmodellen i fyra områden, användes för att identifiera potentiella förändringar för de olika projektaktörernas affärsmodeller. De främsta resultaten indikerar vilka de viktiga framtida aktörerna i en kommersialisering är, graden av affärsmodellsförändring för dem, samt potentiella utmaningar. På grund av osäkerheten kring vilken roll affärsmodeller har vid kommersialisering av tjänster relaterade till urban air mobility bidrar denna avhandling till att ytterligare belysa detta forskningsområde. Konkret identifierar avhandlingen nödvändiga affärsmodellsförändringar för de olika aktörerna, samt specifika områden inom affärsmodellen som behöver mer uppmärksamhet. Dessutom bidrar avhandlingen till forskningslitteraturen om utmaningar relaterade till urban air mobility tjänster, samt föreslår hur de kan hanteras. Slutligen utvärderar och förklarar avhandlingen hur STOF modellen kan utökas till fler branscher än internetbaserade tjänster.
2

Urban Air Mobility Network Asset Acquisition Optimization

Seejay Romello Patel (16997985) 18 September 2023 (has links)
<p dir="ltr">Urban air mobility (UAM) has the potential to revolutionize the transportation industry, offering fast, convenient, and sustainable travel options for passengers and cargo. The development and operation of UAM networks, however, face significant challenges, including the need for infrastructure investments and the management of grid electricity usage. In this thesis, we present a comprehensive model of UAM network operations based on system-of-systems engineering principles and employ a data-driven simulation framework to analyze the expected performance of a UAM operation. Our approach optimizes the composition of the UAM network, including the number of vehicles, chargers, and sizing of solar microgrids, to minimize total acquisition costs while adhering to operational constraints such as maximum average passenger delay and grid usage for each vertiport. Through the application of our methodology to diverse case studies, we provide valuable insights into the optimal design and integration of on-site microgrids for UAM vertiport networks, highlighting their impact on carbon emissions, operating costs, and grid electricity usage. This research contributes to the development of sustainable and efficient UAM systems, supporting informed decision-making among stakeholders involved in the planning, deployment, and operation of urban air mobility networks.</p>
3

Exploring Gymnasielagen (New law on upper secondary education) from professionals’ perspective – A way to integrate or segregate?

Buller, Minna, Rono, Jamine January 2019 (has links)
Swedish parliament in a bid to curb the large numbers of unaccompanied minors who are denied asylum status – came up with a law which is famously known as Gymnasielagen. The aim of the study was to explore how professionals in upper secondary schools setting and social services perceive the implementation of this law and how it contributes to integration of unaccompanied minors in Sweden concerning school environment.  Through semi structured interviews, professionals in contact with unaccompanied minors (UAMs) expressed their perception on the Gymnasielagen and its impacts on the lives of UAMs. The advantages and disadvantages of the law together with its contribution to integration of UAMs were investigated.  The results showed that the law renewed hope for UAMs and gave them the chance to start life afresh after the long wait for asylum. There were however significant discrepancies in the law that makes it difficult for UAMs. The condition to get permanent employment after school completion does not seem achievable and puts pressure on them. They are forced to choose courses from a limited number of technical courses that would possibly get them permanent employment.  Integration was also found not to be optimum because of uncertainty among the UAMs.
4

State and Church involvement in Aboriginal reserves, missions and stations in NSW, 1900-1975 and a translation into French of Custodians of the Soil

Djenidi, Valerie January 2009 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / In this study, we examine the involvement of Churches and Government in New South Wales Aboriginal Reserves and Stations during the twentieth century (1900-1975). Two non-denominational Missions, the United Aborigines’ Mission (UAM) also called the Australian Aborigines’ Mission (AAM) and the Australian Inland Mission (AIM) were particularly active and they both started their work in New South Wales before extending it into other Australian States. Their action in New South Wales was distinctive because it mostly involved women and the missionaries were sent to live with Aboriginal communities. Therefore, unlike the ‘strictly authoritarian’ approach adopted in Northern Territory or Western Australia, missionaries in NSW lived by themselves among people who had settled in Reserves and maintained as much as possible a sense of community. The establishment of Aboriginal Schools gave Missions the opportunity to strengthen their influence among the communities. Elementary education was at the core of the intervention of the Government and the Missions. While the Missions’ involvement was accepted and even encouraged by the State Government at first, as soon as its agency, the Aborigines’ Protection Board was given the legislative power to control Aboriginal people, the Missions were induced to confine themselves to the religious sphere. The study demonstrates that while the White institutions sought to extend their authority over Aboriginal people, the latter were asserting their agency. Thus, some communities appear to have embraced evangelical forms of Christianity when the control of the administration was reaching its peak. As government managers were sent in Aboriginal reserves, in the 1930s, exclusive Native Church Conventions gained momentum. In 1940, the new agency of the Government, the Aborigines’ Welfare Board, aimed at implementing a new policy: the assimilation of Aboriginal people. From that time, the Government became reluctant about the involvement of the Missions and encouraged town local denominational churches to open their congregations to accept Aborigines. This attempt failed as neither the Black nor the White congregations were disposed to integrate. Thus the study highlights how the relations between the Church and the Government ebbed and flowed as both institutions wanted to assert their control over New South Wales Aboriginal communities. The research also demonstrates how Aboriginal people were able to resist within the constraints, revealing a constant negotiation - overt but also concealed - between these three groups. The translation into French of an Australian history book about the relations between Aboriginal people and Europeans is closely related to the historical research. Indeed, the Manning Valley was one of the places where the Missions and later on the Native Churches were particularly influential. Therefore some people like Ella Simon and Bert Marr are present in both works - the thesis and the history book. It seems appropriate to end the thesis with the translation of an interview given by Ella Simon. As always she talks proudly of her Aboriginal culture and at times continues without addressing the interviewer’s question. Thus when the interviewer asked if she is telling a ‘true story and not a legend’, her only answer is: ‘it’s about Forster.' The translation will hopefully offer a more informed view of Australian history and more specifically Aboriginal-European relations to a francophone readership. Although aware that ‘rewriting is a manipulation undertaken in the service of power’, we would like to think that ‘in its positive aspect’, rewriting or translating ‘can help in the evolution of a literature and a society.’
5

An Entropy-based Low Altitude Air Traffic Safety Assessment Framework

Hsun Chao (11819519) 18 December 2021 (has links)
<div>The National Aeronautics and Space Administration (NASA) has a vision for Advanced Air Mobility (AAM) based on safely introducing aviation services to missions that were previously not served or under-served. Many potential AAM missions lie in metropolitan areas that are beset by various types of uncertainty and potential constraints. Radio interference from other electronic devices can render unreliable communication between flying vehicles to ground operators. Buildings have irregular surfaces that degrade GPS localization performance. Skyscrapers can induce spontaneous turbulence that degrades vehicles' navigational accuracy. However, the potential market demands for aerial passenger-carrying and package delivery services have attracted investments. For example, Google WingX, Amazon Prime Air, and Joby Aviation are well-known companies developing AAM systems and services. If the market visions are realized, how will safety be assessed and maintained with high-density AAM operations?</div><div><br></div><div>While there are multiple technology candidates for realizing high-density AAM operations in urban environments, the means to accomplish the requisite first step of assessing the airspace safety of an integrated AAM eco-system from the candidate technologies is crucial but as yet unclear. This dissertation proposes an entropy-based framework for assessing the airspace safety level for low-altitude airspace in an AAM setting. The framework includes a conceptual model for depicting the information flows between air vehicles and an air traffic authority (ATA) and the use of a probability distribution to represent the traffic state. Subsequently, the framework embeds three airspace-level metrics for assessing airspace safety and uncertainty levels. The traffic safety severity metric quantifies the traffic safety level. The traffic entropy quantifies the uncertainty level of the traffic state distribution. Finally, the temperature is the ratio of the traffic safety severity to the traffic entropy. The temperature is similar to the traffic safety severity but gives a higher weight to the instance with a safe traffic state. </div><div><br></div><div>Simulation studies show that the combined use of the three metrics can evaluate relative airspace safety levels even if the unsafe conditions do not occur. The use cases include using the metrics for real-time airspace safety level monitoring and comparing the design of airspace systems and operational strategies. Additionally, this study demonstrates using a heat map to visualize vehicle-level metrics and assess designs of UAM airspace structures. The contribution of this study includes two parts. First, the temperature metric can heuristically assess a probability function. Based on the definition of the cost function, the temperature metric gives a higher weighting to the instance of the probability function with a lower cost value. This study constructs several triggers for predicting if a near-miss event would happen in the airspace. The temperature-based trigger has a better prediction accuracy than the cost-function-based trigger. Secondly, the temperature can visualize the safety level of an airspace structure with the considerations of the environmental and vehicle state measurement uncertainty. The locations with high-temperature values indicate that the regions are more likely to have endangered vehicles. Although this framework does not provide any means of resolving the unsafe conditions, it can be powerful in the comparison of different airspace design concepts and identify the weaknesses of either airspace design or operational strategies. </div>
6

Structural health monitoring with fiber Bragg grating sensors embedded into metal through ultrasonic additive manufacturing

Chilelli, Sean Kelty 23 December 2019 (has links)
No description available.
7

Design, Fabrication, and Analysis of a Multi-Layer, Low-Density, Thermally-Invariant Smart Composite via Ultrasonic Additive Manufacturing

Pritchard, Joshua D. 04 November 2014 (has links)
No description available.
8

Passenger Flight Experience of Urban Air Mobility

Persson, Daniel January 2019 (has links)
The first part of a study of passenger flight experience of Urban Air Mobility was completed. This first part included the design of different Urban Air Mobility vehicle models, in which the passenger flight experience would be quantitatively measured. A first version of a simulator setup, in which the measurements were performed, was also developed. Three concept vehicle models, a single main rotor, a side-by-side rotor and a quadrotor, were designed in the conceptual design software NDARC. The vehicles were electrically propelled with battery technology based on future technology predictions and were designed for autonomous flight with one passenger. The emissions of the vehicles were analyzed and compared with an existing turboshaft helicopter. The interface between NDARC and the flight dynamics analysis and control system software FlightCODE, which was used to create control systems to the NDARC models,  was developed to fit the vehicle configurations considered. The simulator setup was created with a VR headset, the flight simulation software X-Plane, an external autopilot software and stress sensors. Trial runs with the simulator setup were performed and gave important data for the continued development. Planned upgrades of the simulation station were presented and the continuation of the study was discussed.
9

Automated Contingency Management for Passenger-Carrying Urban Air Mobility Operations

Sai V Mudumba (12295691) 19 April 2022 (has links)
<p>As Urban Air Mobility (UAM) is developed and brought into fruition via electric vertical takeoff and landing (eVTOL) vehicles, contingencies associated with this new distributed electric propulsion technology in metropolitan areas must be considered. On the state of knowledge on contingencies for eVTOL vehicles, these can be Epistemological Risks or Ontological Risks. Epistemological Risks include known-knowns (probabilistic risks) and known-unknowns (gaps in knowledge). Ontological Risks include, unknown-knowns (hidden knowledge), unknown-unknowns (fog of ignorance). As UAM operations at large scale do not have as much historical accidents data as General Aviation or Commercial Aviation, it is challenging to estimate its accident failure rate per 100,000 flight hours. While battery thermal runaway, battery energy uncertainty, software issues, and common mode power failures are some failure cases listed in this thesis, it is the undiscovered contingency (i.e., unknown-unknown) or unprepared contingency (i.e., unknown-known), along with other external factors, that can lead to an accident. UAM is expected to operate at 1500 feet AGL and at high frequencies over dense metropolitan areas. In an in-flight emergency at these altitudes, any startle response experienced by on-board or remote pilots can lead to longer response times. This study aims to create a framework for contingency planning and risk mitigation using a Reachable Ground Footprint model for eVTOL aircraft under 100% power failure scenarios in-flight. This framework utilizes all existing, public aerodrome infrastructures in metropolitan areas as potential contingency landing sites. Metrics such as Contingency Landing Assurance Percentage and Cruise Altitude Floor requirement are introduced to quantitatively measuring the safety of any UAM trip and provide recommendations on safe cruising altitudes. A demonstration case in the Chicago Metropolitan Area between DuPage Regional Airport and John H. Stroger Hospital Helipad is shown and discussed. Furthermore, aggregate analysis of 434 UAM trips in Chicago Metropolitan Area between Regional Airports, between Regional and Heliports, and between Heliports is performed, along with sensitivity studies involving wind and turn control restrictions. The results discuss variations in Cruise Altitude Floor, Flight Time, and Energy Consumption of these trips using an eVTOL vehicle.</p>
10

Process Modeling of Ultrasonic Additive Manufacturing

Venkatraman, Gowtham 19 September 2022 (has links)
No description available.

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