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Publications

2023

A Review on the Video Summarization and Glaucoma Detection

Authors
Correia, T; Cunha, A; Coelho, P;

Publication
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST

Abstract
Glaucoma is a severe disease that arises from low intraocular pressure, it is asymptomatic in the initial stages and can lead to blindness, due to its degenerative characteristic. There isn’t any available cure for it, and it is the second most common cause of blindness in the world. Regular visits to the ophthalmologist are the best way to prevent or contain it, with a precise diagnosis performed with professional equipment. From another perspective, for some individuals or populations, this task can be difficult to accomplish, due to several restrictions, such as low incoming resources, geographical adversities, and traveling restrictions (distance, lack of means of transportation, etc.). Also, logistically, due to its dimensions, relocating the professional equipment can be expensive, thus becoming inviable to bring them to remote areas. As an alternative, some low-cost products are available in the market that copes with this need, namely the D-Eye lens, which can be attached to a smartphone and enables the capture of fundus images, presenting as major drawback lower quality imaging when compared to professional equipment. Some techniques rely on video capture to perform summarization and build a full image with the desired features. In this context, the goal of this paper is to present a review of the methods that can perform video summarization and methods for glaucoma detection, combining both to indicate if individuals present glaucoma symptoms, as a pre-screening approach. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

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 H.I.; Silva E.;

Publication
Advances in Science, Technology and Innovation

Abstract
This work addresses reconstructing an ancient mining site in three-dimensional (3D) modelling with robotic systems, processing the information from two visible spectrum cameras. The developed solution, GeoTec System, was validated in an underground environment in the Monastery of Tibães (Braga, NW Portugal). This study was developed under the MineHeritage project's scope, aiming to attain society on the importance of raw materials across a historical approach. The outputs acquired from the datasets developed in a successful 3D reconstruction of the main gallery and secondary tunnels of the Aveleiras mine in Tibães. However, the investigation is still ongoing to contribute to applying 3D reconstruction technologies, GIS-based mapping and geovisualization techniques in the underground heritage environment.

2023

tieval: An Evaluation Framework for Temporal Information Extraction Systems

Authors
Sousa, H; Jorge, A; Campos, R;

Publication
PROCEEDINGS OF THE 46TH INTERNATIONAL ACM SIGIR CONFERENCE ON RESEARCH AND DEVELOPMENT IN INFORMATION RETRIEVAL, SIGIR 2023

Abstract
Temporal information extraction (TIE) has attracted a great deal of interest over the last two decades. Such endeavors have led to the development of a significant number of datasets. Despite its benefits, having access to a large volume of corpora makes it difficult to benchmark TIE systems. On the one hand, different datasets have different annotation schemes, which hinders the comparison between competitors across different corpora. On the other hand, the fact that each corpus is disseminated in a different format requires a considerable engineering effort for a researcher/practitioner to develop parsers for all of them. These constraints force researchers to select a limited amount of datasets to evaluate their systems which consequently limits the comparability of the systems. Yet another obstacle to the comparability of TIE systems is the evaluation metric employed. While most research works adopt traditional metrics such as precision, recall, and..1, a few others prefer temporal awareness - a metric tailored to be more comprehensive on the evaluation of temporal systems. Although the reason for the absence of temporal awareness in the evaluation of most systems is not clear, one of the factors that certainly weighs on this decision is the need to implement the temporal closure algorithm, which is neither straightforward to implement nor easily available. All in all, these problems have limited the fair comparison between approaches and consequently, the development of TIE systems. To mitigate these problems, we have developed tieval, a Python library that provides a concise interface for importing different corpora and is equipped with domain-specific operations that facilitate system evaluation. In this paper, we present the first public release of tieval and highlight its most relevant features. The library is available as open source, under MIT License, at PyPI1 and GitHub(2).

2023

Optical Fiber Flowmeter Based on a Michelson Interferometer

Authors
Monteiro, CS; Ferreira, M; Mendes, JP; Coelho, LCC; Silva, S; Frazão, O;

Publication
EPJ Web of Conferences

Abstract
In this work, an optical fiber flowmeter based on a Michelson interferometer is presented. The Michelson interferometer uses a long period fiber grating (LPFG) to couple light to the cladding modes followed by a section of a GO-coated single mode fiber (SMF). By radiating the GO thin film, it will increase its temperature changing the effective refractive index of the optical cavity of the Michelson interferometer. By placing the sensor on a gas flow, its temperature surface will decrease in a proportional manner to the flow rate. The sensor was studied in both static and dynamic dry nitrogen flow, attaining an absolute sensitivity of 17.4 ± 0.8 pm/(L.min-1) and a maximum response time of 1.1 ± 0.4 s.

2023

Automated Assessment of Simple Web Applications (Short Paper)

Authors
Costa, LM; Leal, JP; Queirós, R;

Publication
ICPEC

Abstract
Web programming education is an important component of modern computer science curricula. Assessing students’ web programming skills can be time-consuming and challenging for educators. This paper introduces Webpal, an automated assessment tool for web programming exercises in entry-level courses. Webpal evaluates web applications coded in HTML, CSS, and Javascript, and provides feedback to students. This tool integrates with Virtual Learning Environments (VLEs) through an API, allowing the creation, storage, and access to exercises while assessing student attempts based on the created exercises. The evaluation process comprises various subcomponents: static assessment, interface matching, functional testing, and feedback management. This approach aims to provide feedback that helps students overcome their challenges in web programming assignments. This paper also presents a demo showcasing the tool’s features and functionality in a simulated VLE environment.

2023

UAV-Assisted Wireless Communications: An Experimental Analysis of A2G and G2A Channels

Authors
Shafafi, K; Almeida, EN; Coelho, A; Fontes, H; Ricardo, M; Campos, R;

Publication
SimuTools

Abstract
Unmanned Aerial Vehicles (UAVs) offer promising potential as communications node carriers, providing on-demand wireless connectivity to users. While existing literature presents various wireless channel models, it often overlooks the impact of UAV heading. This paper provides an experimental characterization of the Air-to-Ground (A2G) and Ground-to-Air (G2A) wireless channels in an open environment with no obstacles nor interference, considering the distance and the UAV heading. We analyze the received signal strength indicator and the TCP throughput between a ground user and a UAV, covering distances between 50 m and 500 m, and considering different UAV headings. Additionally, we characterize the antenna’s radiation pattern based on UAV headings. The paper provides valuable perspectives on the capabilities of UAVs in offering on-demand and dynamic wireless connectivity, as well as highlights the significance of considering UAV heading and antenna configurations in real-world scenarios.

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