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Urban Air Mobility: Deconstructing the Next Revolution in Urban Transportation - Feasibility, Capacity and Productivity
Full text linkOwing to a century of innovation in aircraft design, for the first time in history, air transport presents a potential competitive alternative to road, for hub-to-door and door-to-door urban services. In this dissertation, we first study the feasibility of uncongested air transport, for moving people and goods in an urban area, based on three metrics - enroute travel time, fuel cost and carbon dioxide (CO2) emissions. We estimate the metrics from emission standards and operational assumptions on vehicles based on current market data and compare electric air travel of near future to predominantly gasoline road travel of today. For passenger movement, air is faster than road for all distances. It fares better on fuel cost and emissions for longer distances (specific transition distances are stated in the main text). For consolidated movement of goods, air is at par or better than road dependent on the type of aircraft used. Finally, for movement of unconsolidated goods, air far outperforms road on all three metrics. To enable the feasible air-based services, a typical metropolitan region's airspace needs to accommodate traffic orders of magnitude higher than the manned airspace of today, while staying uncongested to deliver the afore-mentioned benefits. Hence we also develop methods to study the urban airspace capacity. We use our methods to evaluate the airspace capacity for a specific use case of goods movement under 400 feet (low altitude airspace) and find that with today's technologies at least 10,000 free routed small Unmanned Aircraft Systems (sUAS) flights per day can be safely enabled in the San Francisco Bay area. Better onboard technologies would only improve this number. Furthermore, our methods can be extended to evaluate the metropolitan airspace capacity to accommodate other use cases including movement of passengers and goods in a much wider band of airspace.Finally, we look at the energy efficiency, travel time and throughput trade-off between speed and direction control. We find that while maintaining a similar decent throughput, direction control is more energy efficient for enroute tactical resolution unless aircraft can be built with very high hover energy efficiency. However, speed control has a lower impact on travel time extension. Hovering capability additionally offers high flexibility for the type of operations that can be enabled in an urban airspace. Hence, the findings of this dissertation also have policy implications for the aircraft design industry for enabling Urban Air Mobility (UAM). It is quite noteworthy that all our results are based on a road-friendly urban design. Changes in design that facilitate easier access to air-based hub-to-door and door-to-door services, would only make the case stronger for UAM as the next revolution in urban transportation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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Urban Air Mobility: Viability of Hub-Door and Door-Door Movement by Air
Full text linkOwing to a century of innovation in connected and automated aircraft design, for the rst time in history, air transport presents a potential competitive alternative to road, for hub-to-door and door-to-door urban services. In this article, we study the viability of air transport, for moving people and goods in an urban area, based on three metrics - enroute travel time, fuel cost and carbon dioxide (CO2) emissions. We estimate the metrics from emission standards and operational assumptions on vehicles based on current market data and compare electric air travel to gasoline road travel. For passenger movement, air is faster than road for all distances. It fares better on fuel cost and emissions only for longer distances (specic transition distances are stated in the text). For consolidated movement of goods, air is at par with road. Finally, for movement of unconsolidated goods, air again fares better than road on all three metrics. It is also noteworthy that these results are based on a road friendly urban design. Changes in design that facilitate easier access to air based hub-to-door and door-to-door services, would only make the case stronger for Urban Air Mobility (UAM), especially with connected and automated aircraft, as the next revolution in urban transportation
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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