2022
Autores
Reis Pereira, M; Tosin, R; Martins, R; dos Santos, FN; Tavares, F; Cunha, M;
Publicação
PLANTS-BASEL
Abstract
Pseudomonas syringae pv. actinidiae (Psa) has been responsible for numerous epidemics of bacterial canker of kiwi (BCK), resulting in high losses in kiwi production worldwide. Current diagnostic approaches for this disease usually depend on visible signs of the infection (disease symptoms) to be present. Since these symptoms frequently manifest themselves in the middle to late stages of the infection process, the effectiveness of phytosanitary measures can be compromised. Hyperspectral spectroscopy has the potential to be an effective, non-invasive, rapid, cost-effective, high-throughput approach for improving BCK diagnostics. This study aimed to investigate the potential of hyperspectral UV-VIS reflectance for in-situ, non-destructive discrimination of bacterial canker on kiwi leaves. Spectral reflectance (325-1075 nm) of twenty plants were obtained with a handheld spectroradiometer in two commercial kiwi orchards located in Portugal, for 15 weeks, totaling 504 spectral measurements. Several modeling approaches based on continuous hyperspectral data or specific wavelengths, chosen by different feature selection algorithms, were tested to discriminate BCK on leaves. Spectral separability of asymptomatic and symptomatic leaves was observed in all multi-variate and machine learning models, including the FDA, GLM, PLS, and SVM methods. The combination of a stepwise forward variable selection approach using a support vector machine algorithm with a radial kernel and class weights was selected as the final model. Its overall accuracy was 85%, with a 0.70 kappa score and 0.84 F-measure. These results were coherent with leaves classified as asymptomatic or symptomatic by visual inspection. Overall, the findings herein reported support the implementation of spectral point measurements acquired in situ for crop disease diagnosis.
2022
Autores
Ibrahim, B; Rabelo, L; Gutierrez-Franco, E; Clavijo-Buritica, N;
Publicação
ENERGIES
Abstract
A smart grid is the future vision of power systems that will be enabled by artificial intelligence (AI), big data, and the Internet of things (IoT), where digitalization is at the core of the energy sector transformation. However, smart grids require that energy managers become more concerned about the reliability and security of power systems. Therefore, energy planners use various methods and technologies to support the sustainable expansion of power systems, such as electricity demand forecasting models, stochastic optimization, robust optimization, and simulation. Electricity forecasting plays a vital role in supporting the reliable transitioning of power systems. This paper deals with short-term load forecasting (STLF), which has become an active area of research over the last few years, with a handful of studies. STLF deals with predicting demand one hour to 24 h in advance. We extensively experimented with several methodologies from machine learning and a complex case study in Panama. Deep learning is a more advanced learning paradigm in the machine learning field that continues to have significant breakthroughs in domain areas such as electricity forecasting, object detection, speech recognition, etc. We identified that the main predictors of electricity demand in the short term: the previous week's load, the previous day's load, and temperature. We found that the deep learning regression model achieved the best performance, which yielded an R squared (R-2) of 0.93 and a mean absolute percentage error (MAPE) of 2.9%, while the AdaBoost model obtained the worst performance with an R-2 of 0.75 and MAPE of 5.70%.
2022
Autores
Almeida, F;
Publicação
INTERNATIONAL JOURNAL OF ENTREPRENEURSHIP AND INNOVATION
Abstract
The entrepreneurs responsible for establishing university spinoffs are incessantly looking for new ways to leverage existing technology or create an entirely new product or service market. The creation of disruptive innovative solutions has assumed a key role in enhancing the role of university spinoffs in the global marketplace. This study aims to characterize and explore the phenomenon of disruptive innovation in university spinoffs and identify how university spinoffs recognize and evaluate low-end and new-market disruptive technologies. The findings reveal that university spin-offs have essentially privileged new-market disruptive technologies. Participation in trade fairs, conferences and journals have been the main methods adopted by these organizations to identify disruptive technologies, while the evaluation of the potential of these disruptive technologies is essentially based on the experience and scientific knowledge of the founders of the university spin-offs. Furthermore, the size and number of years of activity of university spinoffs are two factors that allow us to understand the greater proximity of the younger and smaller spinoffs with universities and research centers, whereas the larger organizations prioritize mainly market analysis and product research techniques.
2022
Autores
Rocha, R; Retorta, F; Mello, J; Silva, R; Gouveia, C; Villar, J;
Publicação
TECHNOLOGIES, MARKETS AND POLICIES: BRINGING TOGETHER ECONOMICS AND ENGINEERING
Abstract
This paper proposes an energy community management system for local energy sharing with grid flexibility services to solve the potential grid constraints of the local distribution network. A three-stage model is proposed. Stage 1 is the individual minimization of the energy bill of each prosumer by optimizing the schedules of its battery. The second stage optimizes the energy bill of the energy community by sharing internally the prosumers energy surplus and re-dispatching their batteries, while guaranteeing that each new individual prosumer energy bill is always equal or less than its stage 1 bill. The third stage is performed by the DSO to solve the grid constraints by re-dispatching the batteries, curtailing local generation or reducing consumption. Stage 3 minimizes the impact on stage 2 by minimizing the loss of profit or utility of every prosumer which is compensated accordingly.
2022
Autores
Longras, A; Mendes Pereira, TS; Amaral, A;
Publicação
Internet of Everything - The First EAI International Conference, IoECon 2022, Guimarães, Portugal, September 16-17, 2022, Proceedings
Abstract
Medical devices are rapidly evolving and becoming more interconnected with healthcare networks, overcoming resource constraints, and increasingly focused on patient well-being and needs. This work intends to identify future research themes in the area of cybersecurity in health by surveying the articles being developed and identifying their current limitations and future work. The developed analysis was based on the publications with the highest number of citations, enabling us to find several challenges and restrictions such as integrating devices in systems. Innovations and the emergence of new technologies with inherent security vulnerabilities, will continue to evolve, escalating the attackers interest in exploiting unknown cybersecurity risks within healthcare. It is mandatory to consider cybersecurity risks since the conception of the devices to reduce security flaws, ensure the patients with a better quality of life, and guarantee information security properties. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.
2022
Autores
Neto, PC; Oliveira, SP; Montezuma, D; Fraga, J; Monteiro, A; Ribeiro, L; Goncalves, S; Pinto, IM; Cardoso, JS;
Publicação
CANCERS
Abstract
Simple Summary Nowadays, colorectal cancer is the third most incident cancer worldwide and, although it can be detected by imaging techniques, diagnosis is always based on biopsy samples. This assessment includes neoplasia grading, a subjective yet important task for pathologists. With the growing availability of digital slides, the development of robust and high-performance computer vision algorithms can help to tackle such a task. In this work, we propose an approach to automatically detect and grade lesions in colorectal biopsies with high sensitivity. The presented model attempts to support slide decision reasoning in terms of the spatial distribution of lesions, focusing the pathologist's attention on key areas. Thus, it can be integrated into clinical practice as a second opinion or as a flag for details that may have been missed at first glance. Colorectal cancer (CRC) diagnosis is based on samples obtained from biopsies, assessed in pathology laboratories. Due to population growth and ageing, as well as better screening programs, the CRC incidence rate has been increasing, leading to a higher workload for pathologists. In this sense, the application of AI for automatic CRC diagnosis, particularly on whole-slide images (WSI), is of utmost relevance, in order to assist professionals in case triage and case review. In this work, we propose an interpretable semi-supervised approach to detect lesions in colorectal biopsies with high sensitivity, based on multiple-instance learning and feature aggregation methods. The model was developed on an extended version of the recent, publicly available CRC dataset (the CRC+ dataset with 4433 WSI), using 3424 slides for training and 1009 slides for evaluation. The proposed method attained 90.19% classification ACC, 98.8% sensitivity, 85.7% specificity, and a quadratic weighted kappa of 0.888 at slide-based evaluation. Its generalisation capabilities are also studied on two publicly available external datasets.
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