18,761 research outputs found

    Adaptive Airborne Separation to Enable UAM Autonomy in Mixed Airspace

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    The excitement and promise generated by Urban Air Mobility (UAM) concepts have inspired both new entrants and large aerospace companies throughout the world to invest hundreds of millions in research and development of air vehicles, both piloted and unpiloted, to fulfill these dreams. The management and separation of all these new aircraft have received much less attention, however, and even though NASAs lead is advancing some promising concepts for Unmanned Aircraft Systems (UAS) Traffic Management (UTM), most operations today are limited to line of sight with the vehicle, airspace reservation and geofencing of individual flights. Various schemes have been proposed to control this new traffic, some modeled after conventional air traffic control and some proposing fully automatic management, either from a ground-based entity or carried out on board among the vehicles themselves. Previous work has examined vehicle-based traffic management in the very low altitude airspace within a metroplex called UTM airspace in which piloted traffic is rare. A management scheme was proposed in that work that takes advantage of the homogeneous nature of the traffic operating in UTM airspace. This paper expands that concept to include a traffic management plan usable at all altitudes desired for electric Vertical Takeoff and Landing urban and short-distance, inter-city transportation. The interactions with piloted aircraft operating under both visual and instrument flight rules are analyzed, and the role of Air Traffic Control services in the postulated mixed traffic environment is covered. Separation values that adapt to each type of traffic encounter are proposed, and the relationship between required airborne surveillance range and closure speed is given. Finally, realistic scenarios are presented illustrating how this concept can reliably handle the density and traffic mix that fully implemented and successful UAM operations would entail

    SymbioCity: Smart Cities for Smarter Networks

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    The "Smart City" (SC) concept revolves around the idea of embodying cutting-edge ICT solutions in the very fabric of future cities, in order to offer new and better services to citizens while lowering the city management costs, both in monetary, social, and environmental terms. In this framework, communication technologies are perceived as subservient to the SC services, providing the means to collect and process the data needed to make the services function. In this paper, we propose a new vision in which technology and SC services are designed to take advantage of each other in a symbiotic manner. According to this new paradigm, which we call "SymbioCity", SC services can indeed be exploited to improve the performance of the same communication systems that provide them with data. Suggestive examples of this symbiotic ecosystem are discussed in the paper. The dissertation is then substantiated in a proof-of-concept case study, where we show how the traffic monitoring service provided by the London Smart City initiative can be used to predict the density of users in a certain zone and optimize the cellular service in that area.Comment: 14 pages, submitted for publication to ETT Transactions on Emerging Telecommunications Technologie

    Human Motion Trajectory Prediction: A Survey

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    With growing numbers of intelligent autonomous systems in human environments, the ability of such systems to perceive, understand and anticipate human behavior becomes increasingly important. Specifically, predicting future positions of dynamic agents and planning considering such predictions are key tasks for self-driving vehicles, service robots and advanced surveillance systems. This paper provides a survey of human motion trajectory prediction. We review, analyze and structure a large selection of work from different communities and propose a taxonomy that categorizes existing methods based on the motion modeling approach and level of contextual information used. We provide an overview of the existing datasets and performance metrics. We discuss limitations of the state of the art and outline directions for further research.Comment: Submitted to the International Journal of Robotics Research (IJRR), 37 page

    Drones for parcel and passenger transportation: A literature review

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    Delivery drones and ‘air taxis’ are currently among the most intensely discussed emerging technologies, likely to expand mobility into the ‘third dimension’ of low-level airspace. This paper presents a systematic literature review of 111 interdisciplinary publications (2013 - 03/2019). The review systematizes the current socio-technical debate on civil drones for transportation purposes allowing for a (critical) interim assessment. To guide the review process four dimensions of analysis were defined. A total of 2581 relevant quotations were subdivided into anticipated barriers (426), potential problems (1037), proposed solutions (737) and expected benefits (381). We found that the debate is characterized by predominantly technical and regulatory problems and barriers which are considered to prevent or impede the use of drones for parcel and passengers transportation. At the same time, definite economic expectations are juxtaposed with quite complex and differentiated concerns regarding societal and environmental impacts. Scrutinizing the most prevalent transportation-related promises of traffic reduction, travel time saving and environmental relief we found that there is a strong need to provide scientific evidence for the promises linked to the use of drones for transportation. We conclude that the debate on drones for transportation needs further qualification, emphasizing societal benefits and public involvement more strongly.TU Berlin, Open-Access-Mittel - 201

    Shared-Use Bus Priority Lanes On City Streets: Case Studies in Design and Management, MTI Report 11-10

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    This report examines the policies and strategies governing the design and, especially, operations of bus lanes in major congested urban centers. It focuses on bus lanes that operate in mixed traffic conditions; the study does not examine practices concerning bus priority lanes on urban highways or freeways. Four key questions addressed in the paper are: How do the many public agencies within any city region that share authority over different aspects of the bus lanes coordinate their work in designing, operating, and enforcing the lanes? What is the physical design of the lanes? What is the scope of the priority use granted to buses? When is bus priority in effect, and what other users may share the lanes during these times? How are the lanes enforced? To answer these questions, the study developed detailed cases on the bus lane development and management strategies in seven cities that currently have shared-use bus priority lanes: Los Angeles, London, New York City, Paris, San Francisco, Seoul, and Sydney. Through the case studies, the paper examines the range of practices in use, thus providing planners and decision makers with an awareness of the wide variety of design and operational options available to them. In addition, the report highlights innovative practices that contribute to bus lanes’ success, where the research findings make this possible, such as mechanisms for integrating or jointly managing bus lane planning and operations across agencies

    Assessing Laws and Legal Authorities for Obesity Prevention and Control

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    This is the first paper in a two part series on the laws and legal authorities for obesity prevention and control, which resulted from the National Summit on Legal Preparedness for Obesity Prevention and Control in 2008. In this paper, the authors apply the “laws and legal authorities” component of the Centers for Disease Control and Prevention (CDC) legal framework on public health legal preparedness to demonstrate the essential role that law can play in the fight against obesity. Their analysis identified numerous laws and policies in the three vital domains of healthy lifestyles, healthy places, and healthy societies. For example, in terms of healthy lifestyles, governments can impact nutrition through: food subsidies, taxation, and bans; food marketing strategies; and nutritional labeling and education. With regard to healthy places, state and local governments can apply zoning laws and policy decisions to change the environment to encourage healthy eating and physical activity. Governments can promote healthy societies through laws and legal authorities that affect the ability to address obesity from a social perspective (such as antidiscrimination law, health care insurance and benefit design, school and day care for children, and surveillance). This paper describes instances of how current laws and legal authorities affect the public health goal of preventing obesity in both positive and negative ways. It also highlights the progressive use of laws at every level of government (i.e., federal, state, and local) and the interaction of these laws as they relate to obesity prevention and control. In addition, general gaps in the use of law for obesity prevention and control are identified for attention and action. (These gaps serve as the basis for the companion paper, which delineates options for policymakers, practitioners, and other key stakeholders in the improvement of laws and legal authorities for obesity prevention and control.
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