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Publications

Publications by Eduardo Silva

2022

Hyperspectral Imaging Zero-Shot Learning for Remote Marine Litter Detection and Classification

Authors
Freitas, S; Silva, H; Silva, E;

Publication
REMOTE SENSING

Abstract
This paper addresses the development of a novel zero-shot learning method for remote marine litter hyperspectral imaging data classification. The work consisted of using an airborne acquired marine litter hyperspectral imaging dataset that contains data about different plastic targets and other materials and assessing the viability of detecting and classifying plastic materials without knowing their exact spectral response in an unsupervised manner. The classification of the marine litter samples was divided into known and unknown classes, i.e., classes that were hidden from the dataset during the training phase. The obtained results show a marine litter automated detection for all the classes, including (in the worst case of an unknown class) a precision rate over 56% and an overall accuracy of 98.71%.

2022

A SMACC based mission control system for autonomous underwater vehicles

Authors
Carvalho, D; Martins, A; Almeida, JM; Silva, E;

Publication
2022 OCEANS HAMPTON ROADS

Abstract
Scientific and environmental focused deep sea exploration is being expanded and as such a new class of Autonomous Underwater Vehicle (AUV) capable of accessing deep underwater sea bed environment for long periods of time is being deployed. This type of vehicle and the mission environment poses challenges to the mission development as these operations contain many systems that must work together to ensure that the mission requirements are met and that the vehicle is operated safely. As such, a solution based on the SMACC library for Robotic Operating System (ROS) was proposed and tested using a simulator. The results shown were based on the simulation of three missions representative of different scenarios for a deep sea exploration AUV and they were evaluated on the completion of the mission plan.

2022

Unmanned Aerial Vehicle for Wind-Turbine Inspection. Next Step: Offshore

Authors
Dias, A; Almeida, J; Oliveira, A; Santos, T; Martins, A; Silva, E;

Publication
2022 OCEANS HAMPTON ROADS

Abstract
Offshore wind turbine application has been widespread in the last years, with an estimation that in 2030 will reach a total capacity of 234GW. Offshore wind farms introduce advantages in terms of environmental impact (noise, impact on birds, disrupted landscapes) and energy production (34% onshore and 43% offshore). Still, they also introduce scientific challenges in developing methodologies that allow wind farm inspection (preventive maintenance) safety for humans. This paper presents a UAV approach for autonomous inspection of inland windturbine and describes the field tests in Penela, Portugal. From the state-of-the-art available wind turbine inspection, in 2015, we carried out the first autonomous inspection with a UAV. The inspection of wind blades offshore is an ongoing project; therefore, the paper also presents the preliminary results with a simulation environment to validate the 3D LiDAR and the inspection procedure with new challenges effects: floating platform, wind gusts, and unknown initial blade position.

2023

Precipitation-Driven Gamma Radiation Enhancement Over the Atlantic Ocean

Authors
Barbosa, S; Dias, N; Almeida, C; Silva, G; Ferreira, A; Camilo, A; Silva, E;

Publication
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES

Abstract
Gamma radiation over the Atlantic Ocean was measured continuously from January to May 2020 by a NaI(Tl) detector installed on board the Portuguese navy's ship NRP Sagres. Enhancements in the gamma radiation values are identified automatically by an algorithm for detection of anomalies in mean and variance as well as by visual inspection. The anomalies are typically +50% above the background level and relatively rare events (similar to<10% of the days). All the detected anomalies are associated with simultaneous precipitation events, consistent with the wet deposition of scavenged radionuclides. The enhancements are detected in the open ocean even at large distances (+500 km) from the nearest coastline. Back trajectories reveal that half of these events are associated with air masses experiencing continental land influences, but the other half do not display evidence of recent land contact. The enhancements in gamma radiation very far from land and with no evidence of continental fetch from back trajectories are difficult to explain as resulting only from radionuclides with a terrestrial source such as radon and its progeny. Further investigation and additional measurements are needed to improve understanding on the sources of ambient radioactivity in the open ocean and assess whether gamma radiation in the marine environment is influenced not only by radionuclides of terrestrial origin, but also cosmogenic radionuclides, like Beryllium-7, formed in the upper atmosphere but with the ability to be transported downward and serve as a tracer of the aerosols to which it attaches. Plain Language Summary Radioactive elements such as the noble gas radon and those produced by its radioactive decay are naturally present in the environment and used as tracers of atmospheric transport and composition. In particular, the noble gas radon, being inert and of predominantly terrestrial origin, is used to identify pristine marine air masses with no land contamination. Precipitation over land typically brings radon from the atmosphere to the surface, enhancing gamma radiation on the ground, but such enhancements have not been identified before nor expected over the ocean due to the low amount of radon typical of marine air masses. Here we report, for the first time, gamma radiation enhancements associated with precipitation in the oceanic environment, using measurements performed over the Atlantic Ocean in a campaign onboard the Portuguese navy ship NRP Sagres.

2023

GeoTec: A System for 3D Reconstruction in Underground Environment (Aveleiras Mine, Monastery of Tibães, NW Portugal)

Authors
Pires, A; Dias, A; Rodrigues, P; Silva, P; Santos, T; Oliveira, A; Ferreira, A; Almeida, J; Martins, A; Chaminé, I; Silva, E;

Publication
Advances in Science, Technology and Innovation

Abstract

1995

A dynamically configurable control architecture for autonomous mobile robots

Authors
Sousa, JB; Pereira, FL; daSilva, EP;

Publication
PROCEEDINGS OF THE 34TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-4

Abstract
This paper presents a dynamically configurable architecture for the control of autonomous mobile robots based on hierarchic structure whose three levels, organization, coordination and functional layer, are organized linguistically. The main contribution is the concept of dynamic reconfigurability where the notion of architecture coordinator plays a crucial role. The design of the functional layer establishes the primitives for dynamic configuration.

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