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Publicações

2023

Leveraging Social Media as a Source of Mobility Intelligence: An NLP-Based Approach

Autores
Fontes, T; Murcos, F; Carneiro, E; Ribeiro, J; Rossetti, RJF;

Publicação
IEEE OPEN JOURNAL OF INTELLIGENT TRANSPORTATION SYSTEMS

Abstract
This work presents a deep learning framework for analyzing urban mobility by extracting knowledge from messages collected from Twitter. The framework, which is designed to handle large-scale data and adapt automatically to new contexts, comprises three main modules: data collection and system configuration, data analytics, and aggregation and visualization. The text data is pre-processed using NLP techniques to remove informal words, slang, and misspellings. A pre-trained, unsupervised word embedding model, BERT, is used to classify travel-related tweets using a unigram approach with three dictionaries of travel-related target words: small, medium, and big. Public opinion is evaluated using VADER to classify travel-related tweets according to their sentiments. The mobility of three major cities was assessed: London, Melbourne, and New York. The framework demonstrates consistently high average performance, with a Precision of 0.80 for text classification and 0.77 for sentiment analysis. The framework can aggregate sparse information from social media and provide updated information in near real-time with high spatial resolution, enabling easy identification of traffic-related events. The framework is helpful for transportation decision-makers in operational control, tactical-strategic planning, and policy evaluation. For example, it can be used to improve the management of resources during traffic congestion or emergencies.

2023

Sizing of Urban Power Systems Based on Renewable Sources

Autores
Vidal, D; Pinto, T; Baptista, J;

Publicação
Distributed Computing and Artificial Intelligence, Special Sessions I, 20th International Conference, Guimaraes, Portugal, 12-14 July 2023.

Abstract
In recent years, sustainable power supply has become a necessary asset for the daily survival and development of populations. The incentive to the use of renewable energies has been increasing worldwide. Solar energy, in particular, is widespreading fast in countries whose location allows to obtain excellent radiation conditions. In this work, autonomous photovoltaic (PV) systems are studied, having as main aim its application in the supply of urban loads. For this purpose, a PV system is designed to supply the decorative lighting of a monument. Particular emphasis is given to studying the behavior of the energy storage system. The achieved results demonstrate that the use of this type of systems is a very efficient solution for the municipalities to supply several urban loads such as fountains, traffic lights, decorative lighting, among others. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

2023

Risk-Averse Stochastic Programming for Planning Hybrid Electrical Energy Systems: A Brazilian Case

Autores
Kitamura, D; Willer, L; Dias, B; Soares, T;

Publicação
ENERGIES

Abstract
This work presents a risk-averse stochastic programming model for the optimal planning of hybrid electrical energy systems (HEES), considering the regulatory policy applied to distribution systems in Brazil. Uncertainties associated with variables related to photovoltaic (PV) generation, load demand, fuel price for diesel generation and electricity tariff are considered, through the definition of scenarios. The conditional value-at-risk (CVaR) metric is used in the optimization problem to consider the consumer's risk propensity. The model determines the number and type of PV panels, diesel generation, and battery storage capacities, in which the objective is to minimize investment and operating costs over the planning horizon. Case studies involving a large commercial consumer are carried out to evaluate the proposed model. Results showed that under normal conditions only the PV system is viable. The PV/diesel system tends to be viable in adverse hydrological conditions for risk-averse consumers. Under this condition, the PV/battery system is viable for a reduction of 87% in the battery investment cost. An important conclusion is that the risk analysis tool is essential to assist consumers in the decision-making process of investing in HEES.

2023

Data Stream Analytics

Autores
Aguilar Ruiz, S; Bifet, A; Gama, J;

Publicação
Analytics

Abstract
[No abstract available]

2023

Misalignment-Resilient Propagation Model for Underwater Optical Wireless Links

Autores
Araujo, JH; Tavares, JS; Marques, VM; Salgado, HM; Pessoa, LM;

Publicação
SENSORS

Abstract
This paper proposes a multiple-lens receiver scheme to increase the misalignment tolerance of an underwater optical wireless communications link between an autonomous underwater vehicle (AUV) and a sensor plane. An accurate model of photon propagation based on the Monte Carlo simulation is presented which accounts for the lens(es) photon refraction at the sensor interface and angular misalignment between the emitter and receiver. The results show that the ideal divergence of the beam of the emitter is around 15 degrees for a 1 m transmission length, increasing to 22 degrees for a shorter distance of 0.5 m but being independent of the water turbidity. In addition, it is concluded that a seven-lense scheme is approximately three times more tolerant to offset than a single lens. A random forest machine learning algorithm is also assessed for its suitability to estimate the offset and angle of the AUV in relation to the fixed sensor, based on the power distribution of each lens, in real time. The algorithm is able to estimate the offset and angular misalignment with a mean square error of 5 mm (6 mm) and 0.157 rad (0.174 rad) for a distance between the transmitter and receiver of 1 m and 0.5 m, respectively.

2023

In-Field Hyperspectral Proximal Sensing for Estimating Grapevine Water Status to Support Smart Precision Viticulture

Autores
Erica David; Renan Tosin; Igor Gonçalves; Leandro Rodrigues; Catarina Barbosa; Filipe Santos; Hugo Pinheiro; Rui Martins; Mario Cunha;

Publicação
The 3rd International Electronic Conference on Agronomy

Abstract

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