2024
Authors
Reiz, C; Leite, JB; Gouveia, CS; Javadi, MS;
Publication
ELECTRIC POWER SYSTEMS RESEARCH
Abstract
Microgrids are able to improve several features of power systems, such as energy efficiencies, operating costs and environmental impacts. Nevertheless, microgrids' protection must work congruently with power distribution protection to safely take all advantages. This research contributes to enable their protection by proposing a bilevel method to simultaneously solve the allocation and coordination problems, where the proposed scheme also includes local protections of distributed energy resources. The uncertainties associated with generation and loads are categorized by the k-means method, as well. The non-dominated sorting genetic algorithm II is employed in the upper-level task to solve the protection and control devices allocation problem with two opposing objectives. In the lower-level task, a genetic algorithm ensures their coordination. Protection devices include reclosers and fuses from the network, and directional relays for the point of common coupling of microgrids, while control devices consist of remote-controlled switches. In contrast to related works, local devices installed at the point of coupling of distributed generation units are considered as well, such as voltage-restrained overcurrent relays and frequency relays. The optimal solution for the decision-maker is achieved by utilizing the compromise programming technique. Results show the importance of solving the allocation and coordination problems simultaneously, achieving up to $25,000 cost savings compared to cases that solve these problems separately. The integrated strategy allows the network operator to select the optimum solution for the protective system and avoid corrective actions afterward. The results also show the viability of the islanding operation depending on the decision maker's criteria.
2024
Authors
Machado, J; Amorim, E;
Publication
SBBD
Abstract
2024
Authors
Rebelo, PM; Féliz, MC; Oliveira, PM; Sobreira, H; Costa, P;
Publication
ROBOT 2023: SIXTH IBERIAN ROBOTICS CONFERENCE ADVANCES IN ROBOTICS, VOL 1
Abstract
The need for interoperability between robots of different brands and navigation typologies, graph-based and free navigation, is increasing and this has led to the development of a new approach to empower a graph and ROS-based robot fleet manager for the management of free navigation mobile robots. For this implementation and validation, in real tests, the OMRON LD-90 was the mobile robot platform chosen, which has the particularity of not allowing the execution of a waypoints sequence. A software module was developed to exchange data between a non-ROS-based mobile robot and a specific ROS-based robot fleet manager. This is an approach applicable to any free navigation Autonomous Mobile Robot (AMR) with the necessary adaptations regarding the information provided by the different robot brands.
2024
Authors
A. Augusto de Sousa; Vlastimil Havran; Alexis Paljic; Tabitha Peck; Christophe Hurter;
Publication
Abstract
2024
Authors
Ukil, A; Majumdar, A; Jara, AJ; Gama, J;
Publication
2024 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING WORKSHOPS, ICASSPW 2024
Abstract
Deep neural networks (DNN) are used to analyze images, videos, signals and texts require a lot of memory and intensive computing power. For example, the very successful GPT4 model contains more than a few trillion parameters. Although such models are of great impact, but they have been used very little in real-world applications, including industrial Internet of Things, self-driving cars, algorithmic health monitoring for use in limited mobile or edge devices. The requirement to run large models on resource-constrained peripherals has led to significant research interest in compressing DNN models. Signal processing researchers have traditionally advocated data (image/video/audio) compression, and by the way, many of these techniques are used for DNN compression. For example, source coding is a basic technique that has been widely used to compress various DNN models. In this paper, we present our views on the use of signal processing methods for DNN model compression.
2024
Authors
Figueiredo, AMS; Figueiredo, FO;
Publication
Research in Statistics
Abstract
Abstract.: We consider the headline indicators of the Europe 2020 agenda for the European Union countries for several years of the period 2010–2019 and their own national targets for these indicators. The indicators belong to five thematic areas: employment; education; research, development, and innovation; poverty and social exclusion; climate change; and energy. The main objective of this article is to analyze the dynamics and evolution of the EU countries and the Agenda Europe 2020 indicators over the period, taking into account the relations between the indicators for the EU countries along the years. In order to analyze the different data tables, we have used a three-way data methodology, the STATIS methodology. The results obtained show that the countries of the European Union as a whole have made progress towards the global targets set for the different indicators, with some countries making more significant progress than others. The indicators related to research, development, and innovation, as well as climate change and energy, are the ones where the most improvement is needed. The targets set individually for each country, less demanding for some and more daring for others, were generally already achieved in 2019 or are very close to being achieved. © 2025 Elsevier B.V., All rights reserved.
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