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Publicações

2024

Digital Factory for Product Customization: A Proposal for a Decentralized Production System

Autores
Castro, H; Câmara, F; Câmara, E; Avila, P;

Publicação
FLEXIBLE AUTOMATION AND INTELLIGENT MANUFACTURING: ESTABLISHING BRIDGES FOR MORE SUSTAINABLE MANUFACTURING SYSTEMS, FAIM 2023, VOL 1

Abstract
The digitalization and evolution of information technologies within the industry 4.0 have allowed the creation of the virtual model of the production system, called Digital Twin, with the capacity to simulate different scenarios, providing support for better decision-making. This tool not only represents a virtual copy of the physical world that obtains information about the state of the value chain but also illustrates a system capable of changing the development of productive activity towards personalized production, extending product versatility. Decentralized production seeks to respond to these needs because it allows the agglomeration of several services with different geographic locations, promoting the sharing of resources. This paper proposes an architecture for the development of a digital platform of personalization and decentralization of production based on sharing of sustainable resources. With a single tool, it is possible to define the entire production line for a product.

2024

Assessing the Reliability of AI-Based Angle Detection for Shoulder and Elbow Rehabilitation

Autores
Klein, LC; Chellal, AA; Grilo, V; Gonçalves, J; Pacheco, MF; Fernandes, FP; Monteiro, FC; Lima, J;

Publicação
OPTIMIZATION, LEARNING ALGORITHMS AND APPLICATIONS, PT II, OL2A 2023

Abstract
Angle assessment is crucial in rehabilitation and significantly influences physiotherapists' decision-making. Although visual inspection is commonly used, it is known to be approximate. This work aims to be a preliminary study about using the AI image-based to assess upper limb joint angles. Two main frameworks were evaluated: MediaPipe and Yolo v7. The study was performed with 28 participants performing four upper limb movements. The results showed that Yolo v7 achieved greater estimation accuracy than Mediapipe, with MAEs of around 5 degrees and 17 degrees, respectively. However, even with better results, Yolo v7 showed some limitations, including the point of detection in only a 2D plane, the higher computational power required to enable detection, and the difficulty of performing movements requiring more than one degree of Freedom (DOF). Nevertheless, this study highlights the detection capabilities of AI approaches, showing be a promising approach for measuring angles in rehabilitation activities, representing a cost-effective and easy-to-implement solution.

2024

An Object-based Detection Approach for Automating City Accessibility Constraints Mapping

Autores
Moita, S; Moreira, RS; Gouveia, F; Torres, JM; Gerreiro, MS; Ferreira, D; Sucena, S; Dinis, MA;

Publicação
2024 INTERNATIONAL CONFERENCE ON SMART APPLICATIONS, COMMUNICATIONS AND NETWORKING, SMARTNETS-2024

Abstract
There is a widespread social awareness for the need of adequate accessibility (e.g. missing ramps at crosswalks, obstacles and potholes at sidewalks) in the planning of safe and inclusive city spaces for all citizens. Therefore, municipal authorities responsible for planning urban spaces could benefit from the use of tools for automating the identification of areas in need of accessibility improving interventions. This paper builds on the assumption that it is possible to use Machine Learning (ML) pipelines for automating the detection of accessibility constraints in public spaces, particularly on sidewalks. Those pipelines rely mostly on Deep Learning algorithms to automate the detection of common accessibility issues. Current literature approaches rely on the use of traditional classifiers focused on images' datasets containing single-labelled accessibility classes. We propose an alternative approach using object-detection models that provide a more generic and human-like mode, as it will look into wider city pictures to spot multiple accessibility problems at once. Hence, we evaluate and compare the results of a more generic YOLO model against previous results obtained by more traditional ResNet classification models. The ResNet models used in Project Sidewalk were trained and tested on per-city basis datasets of images crowd-labeled with accessibility attributes. By combining the use of the Project Sidewalk and Google Street View (GSV) service APIs, we re-assembled a world-cities-mix dataset used to train, validate and test the YOLO object-detection model, which exhibited precision and recall values above 84%. Our team of architects and civil engineers also collected a labeled image dataset from two central areas of Porto city, which was used to jointly train and test the YOLO model. The results show that training (even with a small dataset of Porto) the cities-mix-trained YOLO model, provides comparable precision values against the ones obtained by ResNet per-city classifiers. Furthermore, the YOLO approach offers a more human-like generic and efficient pipeline, thus justifying its future exploitation on automating cataloging accessibility mappings in cities.

2024

Enhancing ROP plus form diagnosis: An automatic blood vessel segmentation approach for newborn fundus images

Autores
Almeida, J; Kubicek, J; Penhaker, M; Cerny, M; Augustynek, M; Varysova, A; Bansal, A; Timkovic, J;

Publicação
RESULTS IN ENGINEERING

Abstract
Background: ROP Plus Form is an eye disease that can lead to blindness, and diagnosing it requires medical experts to manually examine the retinal condition. This task is challenging due to its subjective nature and poor image quality. Therefore, developing automatic tools for Retinal Blood Vessel Segmentation in fundus images could assist healthcare experts in diagnosing, monitoring, and prognosing the disease. Objective: This study focuses on developing a novel pipeline for automatically segmenting retinal blood vessels. The main requirements are that it can correctly identify the blood vessels in fundus images and perform well on different systems used for newborn evaluation. Methods: The pipeline uses different methods, including CIELAB Enhancement, Background Normalization, BellShaped Gaussian Matched Filtering, Modified Top-Hat operation, and a combination of vesselness filtering composed of Frangi and Jerman Filters. The segmentation is done by determining a threshold using the Triangle Threshold algorithm. A novel filter is also proposed to remove the Optical Disc artifacts from the primary segmentation based on the Circular Hough Transform. The segmentation pipeline is combined with different pretrained Convolution Neural Network architectures to evaluate its automatic classification capabilities. Results: The pipeline was tested with newborn fundus images acquired with Clarity RetCam3 and Phoenix ICON systems. The results were compared against annotations from three ophthalmologic experts. Clarity RetCam3 images achieved an accuracy of 0.94, specificity of 0.95, and sensitivity of 0.81, while Phoenix ICON images achieved an accuracy of 0.94, specificity of 0.97, and sensitivity of 0.83. The pipeline was also tested for the DRIVE Database, achieving an accuracy of 0.95, specificity of 0.97, and sensitivity of 0.82. For the classification task, the best results were achieved with the DenseNet121 architecture with an accuracy of 0.946. Conclusion: The segmentation scores were auspicious and confirmed the clinical relevance of the proposed pipeline. It has also proven to have a good generalization performance, essential for easier clinic integration. Finally, preliminary results on using CNNs showed how our work can be used to develop fully automatic tools for diagnosing ROP Plus form disease.

2024

Analysis of the experimental absorption spectrum of the rabbit lung and identification of its components

Autores
Pinheiro, MR; Tuchin, VV; Oliveira, LM;

Publicação
JOURNAL OF BIOPHOTONICS

Abstract
The broadband absorption coefficient spectrum of the rabbit lung presents some particular characteristics that allow the identification of the chromophores in this tissue. By performing a weighted combination of the absorption spectra of water, hemoglobin, DNA, proteins and the pigments melanin and lipofuscin, it was possible to obtain a good match to the experimental absorption spectrum of the lung. Such reconstruction provided reasonable information about the contents of the tissue components in the lung tissue, and allowed to identify a similar accumulation of melanin and lipofuscin. The broadband absorption coefficient spectrum of the rabbit lung was reconstructed from the absorption spectra of tissue components. The similar accumulation of melanin and lipofuscin was retrieved from the broadband baseline in the absorption coefficient spectrum, and the calculation of the absorption fold ratios for proteins, DNA and hemoglobin provided good results. The method used is innovative and can be improved to allow the quantification of tissue components concentrations directly. image

2024

Optimal Sizing and Energy Management of Battery Energy Storage Systems for Hybrid Offshore Farms

Autores
Varotto, S; Trovato, V; Kazemi Robati, E; Silva, B;

Publicação
2024 IEEE 22ND MEDITERRANEAN ELECTROTECHNICAL CONFERENCE, MELECON 2024

Abstract
This paper investigates the financial benefits stemming from the potential installation of battery energy storage systems behind the meter of a hybrid offshore farm including wind turbines and floating photovoltaic panels. The optimal investment and operation decisions concerning the energy storage system in the hybrid site are assessed by means of a mixed integer linear programming optimization model. The operation is also subject to technical constraints such as limitations on the connection capacity and ramping constraints imposed by the grid operator at the point of common coupling. Three design configurations for the battery system are analysed: I) offshore with the hybrid farm, II) onshore where the grid connection point is, III) both offshore and onshore. The results indicate the financial value of installing battery storage units, and other benefits deriving from this investment, as the reduction of curtailment.

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