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Publicações

2024

A century on diameter measurement techniques in cylindrical structures

Autores
Cardoso, VHR; Caldas, P; Giraldi, MTR; Cernadas, ML; Fernandes, CS; Frazao, O; Costa, JCWA; Santos, JL;

Publicação
MEASUREMENT SCIENCE AND TECHNOLOGY

Abstract
This work addresses the historical development of techniques and methodologies oriented to the measurement of the internal diameter of transparent tubes since the original contributions of Anderson and Barr published in 1923 in the first issue of Measurement Science and Technology. The progresses on this field are summarized and highlighted the emergence and significance of the measurement approaches supported by the optical fiber.

2024

Development of a Controller for the FANUC S-420FD Industrial Robot: A Description of the Graphical User Interface

Autores
Grilo, V; Ferreira, E; Barbosa, A; Chaves, F; Lima, J;

Publicação
ROBOT 2023: SIXTH IBERIAN ROBOTICS CONFERENCE ADVANCES IN ROBOTICS, VOL 1

Abstract
This paper describes the development of a complete controller for the FANUC S-420FD 6-axis industrial robot. The original controller of the robot presented failures that made it impossible to operate and that negatively impacted the academic and research activities. To solve this problem, it was proposed the development of a new open-technology controller and also the design of an intuitive and functional graphical interface, allowing the programming, control and monitoring of the robot parameters. The developed interface offers advanced features such as trajectory programming, custom parameter configuration, and real-time visualization of the robot's state. This work highlights the importance of efficient and affordable solutions for the maintenance of industrial robots in university environments, encouraging scientific and technological advancement in these areas of study.

2024

Pylung: A Supporting Tool for Comparative Study of ViT and CNN-Based Models Used for Lung Nodules Classification

Autores
Marques, F; Pestana, P; Filipe, V;

Publicação
Lecture Notes in Networks and Systems

Abstract
Lung cancer is a significant global health concern, and accurate classification of lung nodules plays a crucial role in its early detection and treatment. This paper evaluates and compares the performance of Vision Transformer (ViT) and Convolutional Neural Network (CNN) models for lung nodule classification using the Pylung tool proposed in this work. The study aims to address the lack of research on ViT in lung nodule classification and proposes ViT as an alternative to CNN. The Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) dataset is utilized for training and evaluation. The Pylung tool is employed for dataset preprocessing and comparison of models. Three models, ViT, VGG16, and ResNet50, are analyzed, and their hyperparameters are optimized using Optuna. The results show that ViT achieves the highest accuracy (99.06%) in nodule classification compared to VGG16 (98.71%) and ResNet50 (98.46%). The study contributes by introducing ViT as a model for lung nodule classification, presenting the Pylung tool for model comparison, and suggesting further investigations to improve the accuracy. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

2024

GLITCH: Polyglot Code Smell Detection in Infrastructure as Code

Autores
Saavedra, N; Ferreira, JF; Mendes, A;

Publicação
ERCIM NEWS

Abstract
GLITCH is a versatile tool designed for detecting code smells in Infrastructure as Code (IaC) scripts across multiple technologies. Developed by researchers from INESC-ID (Lisbon), INESC TEC (Porto), Instituto Superior T & eacute;cnico / University of Lisbon, and the Faculty of Engineering / University of Porto, GLITCH automates the detection of both security and design flaws in scripts written in Ansible, Chef, Docker, Puppet, and Terraform. By using a technology-agnostic framework, GLITCH aims to improve the consistency and efficiency of code smell detection, making it valuable resource for DevOps engineers and researchers focused on software quality.

2024

Heuristics for online three-dimensional packing problems and algorithm selection framework for semi-online with full look-ahead

Autores
Ali, S; Ramos, AG; Carravilla, MA; Oliveira, JF;

Publicação
APPLIED SOFT COMPUTING

Abstract
In online three-dimensional packing problems (3D-PPs), unlike offline problems, items arrive sequentially and require immediate packing decisions without any information about the quantities and sizes of the items to come. Heuristic methods are of great importance in solving online problems to find good solutions in a reasonable amount of time. However, the literature on heuristics for online problems is sparse. As our first contribution, we developed a pool of heuristics applicable to online 3D-PPs with complementary performance on different sets of instances. Computational results showed that in terms of the number of used bins, in all problem instances, at least one of our heuristics had a better or equal performance compared to existing heuristics in the literature. The developed heuristics are also fully applicable to an intermediate class between offline and online problems, referred to in this paper as a specific type of semi-online with full look-ahead, which has several practical applications. In this class, as in offline problems, complete information about all items is known in advance (i.e., full look-ahead); however, due to time or space constraints, as in online problems, items should be packed immediately in the order of their arrival. As our second contribution, we presented an algorithm selection framework, building on developed heuristics and utilizing prior information about items in this specific class of problems. We used supervised machine learning techniques to find the relationship between the features of problem instances and the performance of heuristics and to build a prediction model. The results indicate an 88% accuracy in predicting (identifying) the most promising heuristic(s) for solving any new instance from this class of problems.

2024

Observation of Surface Plasmon Polaritons and Bloch Surface Waves in a Metal-Dielectric Photonic Crystal

Autores
Dias, BS; de Almeida, JMMM; Coelho, LCC;

Publicação
IEEE SENSORS JOURNAL

Abstract
The excitation of two different electromagnetic surface waves-surface plasmon polaritons (SPPs) and Bloch surface waves (BSWs)-is demonstrated in a 1-D metal-dielectric photonic crystal with numerical and experimental studies. The discussed structure consists of an Ag-TiO2 thin-film stack forming a metal-insulator-metal-insulator device. The thickness of the TiO2 layer placed between the metals is tested for two different values (50 and 300 nm), which also allows the excitation of guided-mode resonances. It is observed that BSWs in this metal-dielectric structure behave similar to the case of all-dielectric photonic crystals, whereas the SPP modes display similar properties to those excited in metal-insulator-metal cavities. The sensitivity of these surface states to variations in the refractive index (RI) of the external dielectric is characterized. For the case of the plasmonic modes, a maximum sensitivity of (7.2 +/- 0.3) x 10(3) nm/RIU was measured, while for the BSW the maximum sensitivity was (1.20 +/- 0.05) x 10(2) nm/RIU. Due to the large field enhancement and penetration on external media, these surface states display exceptional properties for application in optical sensors, and the presented results provide interesting possibilities in the design of novel sensing structures with a flexible selection of surface states for interrogation.

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