Resposta acústica de artes de pesca para captura de lula e ocultação à sondagem por golfinhos

Barreto, M., Gatta, M., & Lobo, V. (2022). Resposta acústica de artes de pesca para captura de lula e ocultação à sondagem por golfinhos. In I. H. (Ed.), Atas das 7.as Jornadas de Engenharia Hidrográfica / 2. as Jornadas Luso-Espanholas de Hidrografia (pp. 38-40). Instituto Hidrográfico. https://jornadas.hidrografico.pt/recursos/files/documentos/2022/7JEH-Livro_Atas.pdfA depredação por golfinhos das lulas ferradas nas toneiras da frota de pesca artesanal Micaelense, nos Açores, constitui um problema sócio-económico e de conservação marinha. Na hipótese da resposta das toneiras à sondagem acústica (ecolocalização) por parte dos golfinhos ser significativa, estas seriam um elemento auxiliar que lhes facilitaria a detecção e identificação. Uma mudança nas artes de pesca podia assim ajudar a minimizar os prejuizos causados. Para compreender a detectabilidade através de acústica submarina, caracterizámos a impedância dos materiais e a resposta das toneiras a sinais sonoros de banda curta percorrendo o intervalo espectral dos cliques de golfinhos. Dos ensaios realizados em configuração bi-estática no tanque anecóico, resultam sonogramas, curvas de resposta em frequência e valores quantitativos (target strength) que nos permitem hierarquizar reflectividades e distâncias de detecção. Permitem também comparar comportamento de ecos e sugerir medidas para atenuar a reflectividade (aumentando a furtividade), originando recomendações aos pescadores.publishersversionpublishe

a cascading classifier approach

Mentzingen, H., Antonio, N., & Lobo, V. (2023). Joining metadata and textual features to advise administrative courts decisions: a cascading classifier approach. ARTIFICIAL INTELLIGENCE AND LAW . https://doi.org/10.1007/s10506-023-09348-9Decisions of regulatory government bodies and courts affect many aspects of citizens’ lives. These organizations and courts are expected to provide timely and coherent decisions, although they struggle to keep up with the increasing demand. The ability of machine learning (ML) models to predict such decisions based on past cases under similar circumstances was assessed in some recent works. The dominant conclusion is that the prediction goal is achievable with high accuracy. Nevertheless, most of those works do not consider important aspects for ML models that can impact performance and affect real-world usefulness, such as consistency, out-of-sample applicability, generality, and explainability preservation. To our knowledge, none considered all those aspects, and no previous study addressed the joint use of metadata and text-extracted variables to predict administrative decisions. We propose a predictive model that addresses the abovementioned concerns based on a two-stage cascade classifier. The model employs a first-stage prediction based on textual features extracted from the original documents and a second-stage classifier that includes proceedings’ metadata. The study was conducted using time-based cross-validation, built on data available before the predicted judgment. It provides predictions as soon as the decision date is scheduled and only considers the first document in each proceeding, along with the metadata recorded when the infringement is first registered. Finally, the proposed model provides local explainability by preserving visibility on the textual features and employing the SHapley Additive exPlanations (SHAP). Our findings suggest that this cascade approach surpasses the standalone stages and achieves relatively high Precision and Recall when both text and metadata are available while preserving real-world usefulness. With a weighted F1 score of 0.900, the results outperform the text-only baseline by 1.24% and the metadata-only baseline by 5.63%, with better discriminative properties evaluated by the receiver operating characteristic and precision-recall curves.publishersversionepub_ahead_of_prin

Spatial Clustering Using Hierarchical SOM

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Classe de Ciências

info:eu-repo/semantics/publishedVersio

Implementation of a Passive Acoustic Barrier for Surveillance

Dias, A. R., Santos, N. P., & Lobo, V. (2023). Implementation of a Passive Acoustic Barrier for Surveillance. In OCEANS 2023 - Limerick (pp. 1-6). IEEE Computer Society. https://doi.org/10.1109/OCEANSLimerick52467.2023.10244682With the end of the cold war, the interest in underwater warfare decreased dramatically. However, recent developments have brought underwater warfare back to center stage. Anti-submarine warfare is always one of the major concerns of a navy since it is difficult to detect an enemy submarine in the vast ocean. Conjugating the recent developments in unmanned vehicles and active and passive acoustic surveillance, we can perform better data fusion and increase our knowledge about the events occurring in our waters. The processed data originating from acoustic surveillance can potentially be an essential source of naval intelligence. An acoustic barrier can perform this detection with success. Still, these systems require highly qualified personnel to operate, present a costly infrastructure, and are hard to implement and maintain. Data fusion from multiple sources, and even from low-cost sensors with noisy measures, are a promising solution, especially if resource optimization is a priority. The implementation described in this paper is intended to be proof of concept of a low-cost implementation in shallow waters that can be easily expanded and evolved to different scenarios. The preliminary results obtained confirm that this is a viable solution.authorsversionpublishe

A Portuguese Case Study with Unmanned Vehicles Fighting Spills

Santos, N. P., Moura, R., Antunes, T. L., & Lobo, V. (2024). Revolutionizing Ocean Cleanup: A Portuguese Case Study with Unmanned Vehicles Fighting Spills. Environments - MDPI, 11(10), 1-19. Article 224. https://doi.org/10.3390/environments11100224 --- The research carried out by Nuno Pessanha Santos was supported by national funds through Fundação para a Ciência e a Tecnologia (FCT) under the projects—LA/P/0083/2020, UIDP/50009/2020 and UIDB/50009/2020—Laboratory of Robotics and Engineering Systems (LARSyS). National funds funded the research conducted by Ricardo Moura through FCT, I.P., Center for Mathematics and Applications (NOVA Math) under the scope of the projects UIDB/00297/2020 and UIDP/00297/2020. The research carried out by Victor Lobo was supported by national funds through FCT under the project—UIDB/04152/2020—Centro de Investigação em Gestão de Informação (MagIC)/NOVA IMSIt is of the utmost importance for every country to monitor and control maritime pollution within its exclusive economic zone (EEZ). The European Maritime Safety Agency (EMSA) has developed and implemented the CleanSeaNet (CSN) satellite monitoring system to aid in the surveillance and control of hydrocarbon and hazardous substance spills in the ocean. This system’s primary objective is to alert European Union (EU) coastal states to potential spills within their EEZs, enabling them to take the necessary legal and operational actions. To reduce operational costs and increase response capability, the feasibility of implementing a national network (NN) of unmanned vehicles (UVs), both surface and aerial, was explored using a Portuguese case study. The following approach and analysis can be easily generalized to other case studies, bringing essential knowledge to the field. Analyzing oil spill alert events in the Portuguese EEZ between 2017 and 2021 and performing a strengths, weaknesses, opportunities, and threats (SWOT) analysis, essential information has been proposed for the optimal location of an NN of UVs. The study results demonstrate that integrating spill alerts at sea with UVs may significantly improve response time, costs, and personnel involvement, making maritime pollution combat actions more effective.publishersversionpublishe

Permeation of water as a tool for characterizing the effect of solvent, film thickness and water solubility in cellulose acetate membranes

Cellulose acetate membranes have been used in many applications; of particular interest are reverse osmosis systems, and as a neutral matrix for incorporation of different polymers (e.g., conducting polymers), inorganic ions (e.g., lanthanides) and organic (e.g., pharmaceutical) compounds. The properties of the new polymers derived from cellulose acetate or blends depend on those of cellulose acetate. This work presents an attempt to find links between thermodynamic and kinetic properties of cellulose acetate membranes in equilibrium with water. Water diffusion coefficients in cellulose acetate membranes are reported, measured with a simple water permeation technique. The comparison of these values with the percentage of water uptake and polymer thickness leads to interesting conclusions related with different polymer properties.http://www.sciencedirect.com/science/article/B6TWW-4DVBFCN-7/1/63e48f8aac1513c35feeaa6c746621e

Side-scan sonar imaging data of underwater vehicles for mine detection

Santos, N. P., Moura, R., Torgal, G. S., Lobo, V., & Neto, M. D. C. (2024). Side-scan sonar imaging data of underwater vehicles for mine detection. Data in brief, 53, 1-8. Article 110132. https://doi.org/10.1016/j.dib.2024.110132, https://doi.org/10.6084/m9.figshare.24574879 --- This work was supported by the national project MArIA - Plataforma Integrada de desenvolvimento de modelos de Inteligência artificial para o mar, with grant number POCI-05-5762-FSE-000400. The research conducted by Ricardo Moura was funded by the Fundação para a Ciência e a Tecnologia (FCT) - Center for Mathematics and Applications (NOVA Math) under the projects UIDB/00297/2020 (https://doi.org/10.54499/UIDB/00297/2020) and UIDP/00297/2020 (https://doi.org/10.54499/UIDP/00297/2020). The research carried out by Victor Lobo and Miguel de Castro Neto was supported by national funds through FCT under the project - UIDB/04152/2020 - Centro de Investigação em Gestão de Informação (MagIC)/NOVA IMS.Unmanned vehicles have become increasingly popular in the underwater domain in the last decade, as they provide better operation reliability by minimizing human involvement in most tasks. Perception of the environment is crucial for safety and other tasks, such as guidance and trajectory control, mainly when operating underwater. Mine detection is one of the riskiest operations since it involves systems that can easily damage vehicles and endanger human lives if manned. Automating mine detection from side-scan sonar images enhances safety while reducing false negatives. The collected dataset contains 1170 real sonar images taken between 2010 and 2021 using a Teledyne Marine Gavia Autonomous Underwater Vehicle (AUV), which includes enough information to classify its content objects as NOn-Mine-like BOttom Objects (NOMBO) and MIne-Like COntacts (MILCO). The dataset is annotated and can be quickly deployed for object detection, classification, or image segmentation tasks. Collecting a dataset of this type requires a significant amount of time and cost, which increases its rarity and relevance to research and industrial development.publishersversionpublishe

HOPS - Hamming-Oriented Partition Search for production planning in the spinning industry

In this paper, we investigate a two-stage lot-sizing and scheduling problem in a spinning industry.A new hybrid method called HOPS (Hamming-Oriented Partition Search), which is a branch-and-bound based procedure that incorporates a fix-and-optimize improvement method is proposedto solve the problem. An innovative partition choice for the fix-and-optimize is developed. The computational tests with generated instances based on real data show that HOPS is a goodalternative for solving mixed integer problems with recognized partitions such as the lot-sizing and scheduling problem

Intrathoracic gastric volvulus: an autopsy case report

First described by Berti in 1866, gastric volvulus (GV) is an uncommon and potentially lethal entity. GV occurs when the stomach twists by more than 180º resulting in obstruction of the alimentary tract, visceral ischemia, necrosis, and perforation. It is classified according to the rotation axis in organoaxial, mesenteroaxial or a combination of both. The clinical presentation can be acute, and is usually severe or chronic, which sometimes may be asymptomatic. It predominantly occurs in the fifth decade of life, but children, mainly those under the age of 1 year, may be affected. No ethnicity or gender was observed to show predominance. This entity is related to gastric, diaphragmatic disorders as well as laxity of gastric ligaments. Acute GV may complicate with incarceration and strangulation of the stomach when gastric necrosis ensues. These cases show a mortality rate of 60%. The authors report the fatal case of a surgically treated GV in a 43-year-old female patient who looked for medical care only after 1 month of initial symptoms. Diagnosis was confirmed with a thoracic and abdominal axial computed tomography. Besides the entire stomach being herniated and twisted into the thoracic cavity, the pancreas was pulled up through the hiatal orifice, provoking acute pancreatitis. Because of gastric necrosis and perforation, gastroenteric fluid drained into the mediastinum and left pleural space. The postoperative outcome was unfavorable resulting in the patient’s death. The authors call attention to the severeness of the disease, and therefore the need of precocity of diagnosis and surgical treatment