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- A subjective quality estimation tool for the evaluation of video communication systemsPublication . Monteiro, Jânio; Nunes, Mário S.This paper presents a quantification tool for the evaluation of scalable and non-scalable video communication systems. The proposed mechanism estimates the subjective quality of experience (QoE) of a human viewer according to the temporal resolution, the spatial resolution and the Root Mean Square of the Error (RMSE) between the original image and the encoded one. According to these three dimensions of quality it enables an encoder and server to search for the best combination of each of these scalability factors in order to deliver the best quality. The proposed quantification tool was obtained through subjective tests using a panel of evaluators and a new methodology which have shown good correlation factors between measurement data and estimating functions.
- Anomaly detection of consumption in Hotel Units: A case study comparing isolation forest and variational autoencoder algorithmsPublication . Mendes, Tomás; Cardoso, Pedro; Monteiro, Jânio; Raposo, JoãoBuildings are responsible for a high percentage of global energy consumption, and thus, the improvement of their efficiency can positively impact not only the costs to the companies they house, but also at a global level. One way to reduce that impact is to constantly monitor the consumption levels of these buildings and to quickly act when unjustified levels are detected. Currently, a variety of sensor networks can be deployed to constantly monitor many variables associated with these buildings, including distinct types of meters, air temperature, solar radiation, etc. However, as consumption is highly dependent on occupancy and environmental variables, the identification of anomalous consumption levels is a challenging task. This study focuses on the implementation of an intelligent system, capable of performing the early detection of anomalous sequences of values in consumption time series applied to distinct hotel unit meters. The development of the system was performed in several steps, which resulted in the implementation of several modules. An initial (i) Exploratory Data Analysis (EDA) phase was made to analyze the data, including the consumption datasets of electricity, water, and gas, obtained over several years. The results of the EDA were used to implement a (ii) data correction module, capable of dealing with the transmission losses and erroneous values identified during the EDA’s phase. Then, a (iii) comparative study was performed between a machine learning (ML) algorithm and a deep learning (DL) one, respectively, the isolation forest (IF) and a variational autoencoder (VAE). The study was made, taking into consideration a (iv) proposed performance metric for anomaly detection algorithms in unsupervised time series, also considering computational requirements and adaptability to different types of data. (v) The results show that the IF algorithm is a better solution for the presented problem, since it is easily adaptable to different sources of data, to different combinations of features, and has lower computational complexity. This allows its deployment without major computational requirements, high knowledge, and data history, whilst also being less prone to problems with missing data. As a global outcome, an architecture of a platform is proposed that encompasses the mentioned modules. The platform represents a running system, performing continuous detection and quickly alerting hotel managers about possible anomalous consumption levels, allowing them to take more timely measures to investigate and solve the associated causes.
- A digital twin of charging stations for fleets of electric vehiclesPublication . Francisco, André; Monteiro, Jânio; Cardoso, PedroThe increasing concern over the environmental impact of fossil fuels and associated CO2 emissions created a growing interest on the use of electric vehicles (EVs) and green energy utilization. In this context, the widespread adoption of EVs should be accompanied by the introduction of generation from renewable energy sources (RES). That insertion, at the distribution level, presents challenges that result from their intermittent nature, requiring demand-response measures that can be addressed by adjusting the charging processes to match the available power. In the framework of EVs renting companies, it is essential to have an efficient charging management that allows achieving high levels of self-consumption and self-sufficiency, lower operational costs and lower payback periods for the investments made. The utilization of digital twins (DTs) can be key to achieve those goals, providing accurate simulations and predictions. Their use in the context of EV charging can offer valuable insights into optimizing charging scheduling and predicting energy demands, taking into consideration distinct scenarios. This paper presents the work done to implement DTs of a set of charging stations (CSs) and EVs, which allow the modeling and improved management of the charging processes of EV fleets, for a set of CSs, integrating RES. In this charging context, experimental results using the DT were applied considering a predicted mobility. The applied scenarios supported an effective and optimized managing performance, reaching low paybacks and high self-sufficiency values. The obtained results show that this method is a viable and cost-effective solution for companies renting EVs.
- Energy transition process and community engagement on geographic islands: the case of Culatra Island (Ria Formosa, Portugal)Publication . Pacheco, André; Monteiro, Jânio; Santos, Joni; Sequeira, Claudia; Nunes, J.Islands have the potential to be precursors in the transition to clean energy, by adopting new technologies and applying innovative solutions that can serve as showcases at an international level. This paper is a contribution towards understating the importance of community engagement on energy transition processes. It covers multiple aspects of a green transition process, including technical, environmental, social, and economic issues. Starting by a participatory diagnosis process, the community of a small island located in Portugal (Culatra Island, Algarve), was challenged to lead the transition process and define different pillars of energy transition. The process brought together local authorities, academia, citizens and companies. Using practical examples, it is shown how the community is succeeding in tailoring new technological solutions for a green transition, according with the specific needs of the island, as expressed by the islanders themselves, including batteries, electric vehicles, retrofitting of homes, or heat pumps, which, when combined, could lay the foundations for the creation of a Renewable Energy Community and leverage socioeconomic benefits.
- A Gray Code model for the encoding of grid cells in the Entorhinal CortexPublication . Monteiro, Jânio; Pedro, André; Silva, AntónioIn the brains of humans and mammals, the formation of episodic memories results from the association between objects, space and time. Both the hippocampus and the entorhinal cortex have shown to play an essential role in the formation of these memories. The hippocampus may be considered as an indexer of the pattern of neocortical activity produced by an episode, while the entorhinal cortex is characterized as performing time and space integration, conveying that information to the hippocampus, in the form of grid cells. Although these grid cells are biological based, non-biological grid cells are used in discrete global grid systems that currently support the indexing of assets across the globe, allowing a more adequate partitioning of the Earth into logical structures that take into account the heterogeneity of the scales of the associated geospatial data. The reasons that led to the definition of these grid systems at macro-levels may have led to the formation of similar structures inside our brains. In this paper, we investigate a representation that unifies these views, creating new types of Gray encodings for both one- and two-dimensional spaces. We start by defining a multilayer ternary encoder based on an equilateral triangular coordinate system. After defining a space filling method for this two-dimensional architecture, two Gray codes for one-dimensional signals are defined, for both circular/periodic and non-circular representations of signals. An algorithm is defined to build the two-dimensional Gray encoding of grid cells, which is then successfully applied in a navigation system of a robot, generating patterns of grid cells similar with the ones observed in neuroscience.
- Improving energy efficiency in smart-houses by optimizing electrical loads managementPublication . Cabrita, Cristiano Lourenço; Monteiro, Jânio; Cardoso, PedroIn this work, the Genetic Algorithm is explored for solving a predictive based demand side management problem (a combinatorial optimization problem) and the main measures lbr performance evaluation are evaluated. In this context, we propose a smart energy scheduling approach for household appliances in real-time to achieve minimum consumption costs and a reduction in peak load. We consider a scenario of selfconsumption where the surplus from local power generation can be sold to the grid, and the existence of appliances that can be shiftable from peak hours to off-peak hours. Results confirm the importance of the tuning procedure and the structure of the genome and algorithm's operators determine the performance of such type of meta-heuristics. This fact is more decisive when there are several operational constraints on the system, as for example short-term optimal scheduling decision, time constraints and power limitations. Details about the scheduling problem, comparison strategies, metrics, and results are provided.
- A QoS Solution for Three-Dimensional Full-HD H.264/MVC Video Transmission over IP NetworksPublication . Bento, Diogo M.; Monteiro, JânioTridimensional video streaming has recently drawn significant attention from users and content providers. This has led to an implementation of 3D transmission over IP networks that extend the legacy 2D solution to support multiple views within each image. More recently, a Multiview Video Coding amendment of the H.264 standard has been approved which, among other applications, is being used on the encoding of 3D content in Blu-ray discs. This latter solution has shown to be capable of improving the compression ratio when compared with the Side-by-Side encoding, by exploring inter-view redundancies. In this paper, we evaluate the challenges of encoding and transmitting 3D content in MVC, for Full HD content distribution over IP networks. We also design and evaluate a Weighted RED queuing mechanism for QoS capable networks based on the MVC structure is capable of improving the quality of the received video.
- GyGSLA: A portable glove system for learning sign language alphabetPublication . Sousa, Luis; Rodrigues, João; Monteiro, Jânio; Cardoso, Pedro J. S.; Lam, RobertoThe communication between people with normal hearing with those having hearing or speech impairment is difficult. Learning a new alphabet is not always easy, especially when it is a sign language alphabet, which requires both hand skills and practice. This paper presents the GyGSLA system, standing as a completely portable setup created to help inexperienced people in the process of learning a new sign language alphabet. To achieve it, a computer/mobile game-interface and an hardware device, a wearable glove, were developed. When interacting with the computer or mobile device, using the wearable glove, the user is asked to represent alphabet letters and digits, by replicating the hand and fingers positions shown in a screen. The glove then sends the hand and fingers positions to the computer/mobile device using a wireless interface, which interprets the letter or digit that is being done by the user, and gives it a corresponding score. The system was tested with three completely inexperience sign language subjects, achieving a 76% average recognition ratio for the Portuguese sign language alphabet.
- On a new method to design solar photovoltaic systems in renewable energy communities: The case of Culatra Island (Ria Formosa, Portugal)Publication . Ewart, M.; Santos, J.; Pacheco, A.; Monteiro, Jânio; Sequeira, ClaudiaIslands must reach sustainable lifestyles by improving resources management and by getting accustomed to renewable energy sources. Culatra, a small Portuguese island, is actively increasing renewable energy penetration into local processes in order to be the first 100% sustainable Portuguese territory by 2030. Based on the electric consumption of Culatra, the objective of the present study is to project a photovoltaic unit composed of several sub-fields, each with a distinct orientation, in order to increase the self-consumption ratio while at the same time reducing the surplus of energy production, assessed by the self-sufficiency ratio criteria, resulting in a lower levelised cost of energy of the power system. To achieve this, MATLAB's implementation of a genetic algorithm was used to find the optimised set of orientations for a given load profile. The results indicate that it is possible to optimise the photovoltaic plant to reach a more continuous electricity generation through daytime, reducing the storage needs and increasing the value of photovoltaic systems. The method can be extended to other locations or demand curves, assisting on comparing different energy management strategies, and their respective advantages and disadvantages.
- Livro de Atas, 9.º Congresso Nacional de Práticas Pedagógicas no Ensino Superior, 6 e 7 de julho de 2023Publication . Esteves, Eduardo; Estêvão, Maria Dulce da Mota Antunes de Oliveira ; Monteiro, Jânio; Correia, MarisolJá com a próxima edição do CNaPPES no horizonte, temos uma enorme satisfação de vos apresentar o Livro de Atas do 9.º Congresso Nacional de Práticas Pedagógicas no Ensino Superior, CNaPPES.23, onde poderão encontrar todos os artigos completos que os autores entenderam partilhar connosco, também sujeitos a revisão antes desta sua publicação. O CNaPPES nasceu para permitir e promover a partilha pedagógica no Ensino Superior e esta é a melhor forma de refletirmos juntos sobre o que funcionou (e não funcionou) em contexto real de prática pedagógica, nas diversas áreas do Ensino Universitário e o Ensino Politécnico. Neste livro poderão reencontrar os contactos dos diversos autores, o que poderá permitir uma maior proximidade entre elementos da comunidade académica que têm interesses comuns.