Utilização de dados de mobilidade para prever o tempo de chegada de autocarros em cidades inteligentes

Connected cities use pervasive information and communication technologies, especially sensing and data analysis, to offer new decision support tools and services. One of the key use cases of connected cities is smart mobility, which addresses the use of computational tools to enhance transportation systems and private mobility. In this context, reliable information systems concerning bus arrival times provide useful services for end-users. Porto is often presented as a smart city, which has deployed a Vehicular Ad-Hoc Network with more than 600 vehicles (buses, taxis and garbage trucks) generating data regarding the GPS location of the (moving) nodes. Traces of buses location offer new possibilities to understand the city mobility patterns. The goal of this work is to develop a system for estimating bus arrival times, using Machine Learning techniques in the data available from the existing vehicular network. The developed system has three main modules: (1) line detection, responsible for inferring possible lines on which a bus may be operating; (2) machine learning model capable of predicting travel times between two bus stops and (3) service linking the current context of buses’ locations with the historical prediction model that returns predictions for a given destination stop. The prediction results obtained are in line with those reported in the literature. A proof-of-concept mobile application for the citizen was also developed, demonstrating the real-life applicability of the system.As cidades inteligentes utilizam informação pervasiva e tecnologias de comunicação, nomeadamente a detecção e a análise de dados, para fornecer novas ferramentas e serviços de apoio à decisão. Um dos principais casos de uso é a mobilidade inteligente, que aborda o uso de ferramentas computacionais para melhorar os sistemas de transporte e a mobilidade privada. Neste contexto, os sistemas de informação fiáveis relativos a tempos de chegada dos autocarros proporcionam serviços úteis para os utilizadores finais. A cidade do Porto é frequentemente apresentada como uma cidade inteligente, que tem implementada uma rede veicular que incorpora mais de 600 veículos (autocarros, táxis e camiões do lixo) gerando dados sobre a localização GPS dos nós (móveis). Os registos de localização dos autocarros oferecem novas possibilidades para compreender os padrões de mobilidade da cidade. O objetivo desta dissertação é o desenvolvimento de um sistema capaz de estimar o tempo de chegada dos autocarros, utilizando técnicas de aprendizagem automática sobre os dados disponíveis da rede veicular existente. O sistema desenvolvido tem três módulos principais: (1) deteção de linhas, responsável por inferir possíveis linhas que um autocarro possa estar a operar; (2) modelo de aprendizagem automática capaz de prever o tempo de viagem de um autocarro entre duas paragens e (3) serviço que liga o contexto atual da localização dos autocarros com o modelo de previsão histórica que devolve as previsões para uma dada paragem de destino. Os resultados de previsão obtidos estão em linha com os relatados na literatura. Como prova de conceito, também foi desenvolvida uma aplicação móvel para os passageiros, demonstrando a aplicabilidade prática do sistema.Mestrado em Engenharia Informátic

The economics of crowding in urban rail transport

Crowding is a major source of inconvenience for public transport users in densely populated metropolitan areas globally, while eliminating crowding requires costly investments. Crowding can be considered as a cornerstone phenomenon of public transport theory, as the interaction between demand and supply side policies. This PhD thesis aims to improve our understanding of the mechanics behind crowding, using microeconomic modelling techniques. From a demand perspective, the crucial precondition of any objective economic analysis is to reliably quantify the inconvenience caused by crowding. In pursuit of this goal, the thesis develops a statistical model to infer the user cost of crowding from metro passengers' route choice decisions. As an important intermediate research outcome, the thesis delivers a novel passenger-to-train assignment algorithm that recovers the network-level crowding pattern of a metro system. Our method is a unique contribution in the sense that it is based on large-scale automated datasets: we use smart card and automated vehicle location data only. The theoretical part of the thesis provides new insights into crowding pricing and capacity optimisation. One of the key messages of the thesis is that crowding in certain time periods and network segments is an unavoidable feature of optimal public transport provision, when demand fluctuates by time and space, but capacity cannot be differentiated between jointly served markets. We show that pricing can be an efficient tool to tackle the deficiency caused by this technological constraint. The thesis devotes special attention to two policy relevant applications: (i) the external cost of seat occupancy, an externality inversely proportional to the density of crowding, and (ii) the inefficiency of unlimited-use travel passes. Our conclusions may assist researchers and practitioners in better understanding the true cost of public transport usage and the related aspects of optimal policy design, including pricing, subsidisation and capacity provision.Open Acces

On Fault Tolerance Methods for Networks-on-Chip

Technology scaling has proceeded into dimensions in which the reliability of manufactured devices is becoming endangered. The reliability decrease is a consequence of physical limitations, relative increase of variations, and decreasing noise margins, among others. A promising solution for bringing the reliability of circuits back to a desired level is the use of design methods which introduce tolerance against possible faults in an integrated circuit. This thesis studies and presents fault tolerance methods for network-onchip (NoC) which is a design paradigm targeted for very large systems-onchip. In a NoC resources, such as processors and memories, are connected to a communication network; comparable to the Internet. Fault tolerance in such a system can be achieved at many abstraction levels. The thesis studies the origin of faults in modern technologies and explains the classification to transient, intermittent and permanent faults. A survey of fault tolerance methods is presented to demonstrate the diversity of available methods. Networks-on-chip are approached by exploring their main design choices: the selection of a topology, routing protocol, and flow control method. Fault tolerance methods for NoCs are studied at different layers of the OSI reference model. The data link layer provides a reliable communication link over a physical channel. Error control coding is an efficient fault tolerance method especially against transient faults at this abstraction level. Error control coding methods suitable for on-chip communication are studied and their implementations presented. Error control coding loses its effectiveness in the presence of intermittent and permanent faults. Therefore, other solutions against them are presented. The introduction of spare wires and split transmissions are shown to provide good tolerance against intermittent and permanent errors and their combination to error control coding is illustrated. At the network layer positioned above the data link layer, fault tolerance can be achieved with the design of fault tolerant network topologies and routing algorithms. Both of these approaches are presented in the thesis together with realizations in the both categories. The thesis concludes that an optimal fault tolerance solution contains carefully co-designed elements from different abstraction levelsSiirretty Doriast

Technical Workshop: Advanced Helicopter Cockpit Design

Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration

Coordinated Transit Response Planning and Operations Support Tools for Mitigating Impacts of All-Hazard Emergency Events

This report summarizes current computer simulation capabilities and the availability of near-real-time data sources allowing for a novel approach of analyzing and determining optimized responses during disruptions of complex multi-agency transit system. The authors integrated a number of technologies and data sources to detect disruptive transit system performance issues, analyze the impact on overall system-wide performance, and statistically apply the likely traveler choices and responses. The analysis of unaffected transit resources and the provision of temporary resources are then analyzed and optimized to minimize overall impact of the initiating event

Electronic/electric technology benefits study

The benefits and payoffs of advanced electronic/electric technologies were investigated for three types of aircraft. The technologies, evaluated in each of the three airplanes, included advanced flight controls, advanced secondary power, advanced avionic complements, new cockpit displays, and advanced air traffic control techniques. For the advanced flight controls, the near term considered relaxed static stability (RSS) with mechanical backup. The far term considered an advanced fly by wire system for a longitudinally unstable airplane. In the case of the secondary power systems, trades were made in two steps: in the near term, engine bleed was eliminated; in the far term bleed air, air plus hydraulics were eliminated. Using three commercial aircraft, in the 150, 350, and 700 passenger range, the technology value and pay-offs were quantified, with emphasis on the fiscal benefits. Weight reductions deriving from fuel saving and other system improvements were identified and the weight savings were cycled for their impact on TOGW (takeoff gross weight) and upon the performance of the airframes/engines. Maintenance, reliability, and logistic support were the other criteria

Mu2e Technical Design Report

The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- N with a sensitivity approximately four orders of magnitude better than the current world's best limits for this process. The experiment's sensitivity offers discovery potential over a wide array of new physics models and probes mass scales well beyond the reach of the LHC. We describe herein the preliminary design of the proposed Mu2e experiment. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2 approval.Comment: compressed file, 888 pages, 621 figures, 126 tables; full resolution available at http://mu2e.fnal.gov; corrected typo in background summary, Table 3.