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Publicações

2024

Context-Aware System for Information Flow Management in Factories of the Future

Autores
Monteiro, P; Pereira, R; Nunes, R; Reis, A; Pinto, T;

Publicação
APPLIED SCIENCES-BASEL

Abstract
The trends of the 21st century are challenging the traditional production process due to the reduction in the life cycle of products and the demand for more complex products in greater quantities. Industry 4.0 (I4.0) was introduced in 2011 and it is recognized as the fourth industrial revolution, with the aim of improving manufacturing processes and increasing the competitiveness of industry. I4.0 uses technological concepts such as Cyber-Physical Systems, Internet of Things and Cloud Computing to create services, reduce costs and increase productivity. In addition, concepts such as Smart Factories are emerging, which use context awareness to assist people and optimize tasks based on data from the physical and virtual world. This article explores and applies the capabilities of context-aware applications in industry, with a focus on production lines. In specific, this paper proposes a context-aware application based on a microservices approach, intended for integration into a context-aware information system, with specific application in the area of manufacturing. The manuscript presents a detailed architecture for structuring the application, explaining components, functions and contributions. The discussion covers development technologies, integration and communication between the application and other services, as well as experimental findings, which demonstrate the applicability and advantages of the proposed solution.

2024

Eight Weeks of Intermittent Exercise in Hypoxia, with or without a Low-Carbohydrate Diet, Improves Bone Mass and Functional and Physiological Capacity in Older Adults with Type 2 Diabetes

Autores
Kindlovits, R; Sousa, AC; Viana, JL; Milheiro, J; Oliveira, BMPM; Marques, F; Santos, A; Teixeira, VH;

Publicação
NUTRIENTS

Abstract
In an increasingly aging and overweight population, osteoporosis and type 2 diabetes (T2DM) are major public health concerns. T2DM patients experience prejudicial effects on their bone health, affecting their physical capacity. Exercise in hypoxia (EH) and a low-carbohydrate diet (LCD) have been suggested for therapeutic benefits in T2DM, improving bone mineral content (BMC) and glycemic control. This study investigated the effects of EH combined with an LCD on body composition and functional and physiologic capacity in T2DM patients. Older T2DM patients (n = 42) were randomly assigned to the following groups: (1) control group: control diet + exercise in normoxia; (2) EH group: control diet + EH; (3) intervention group: LCD + EH. Cardiopulmonary tests (BRUCE protocol), body composition (DEXA), and functional capacity (6MWT, handgrip strength) were evaluated. Body mass index (kg/m(2)) and body fat (%) decreased in all groups (p < 0.001). BMC (kg) increased in all groups (p < 0.001) and was significantly higher in the EH and EH + LCD groups (p < 0.001). VO2peak improved in all groups (p < 0.001), but more so in the hypoxia groups (p = 0.019). Functional capacity was increased in all groups (p < 0.001), but more so in the EH group in 6MWT (p = 0.030). EH with and without an LCD is a therapeutic strategy for improving bone mass in T2DM, which is associated with cardiorespiratory and functional improvements.

2024

COMBINING BATTERIES AND SYNCHRONOUS CONDENSERS: THE CASE STUDY OF MADEIRA ISLAND

Autores
Fernandes, F; Lopes, JP; Moreira, C;

Publicação
IET Conference Proceedings

Abstract
This paper investigates the stability of a converter-dominated islanded power system when the island’s battery energy storage converters are operated in different control modes (Grid Forming and Grid Following) and combined with different volumes of synchronous compensation. The study is conducted in a realistic simulation model of the future Madeira island, where no thermal generation is present, and the share of converter-based Renewable Energy Sources is large (75 to 80 % of instantaneous penetration). The impact of the different combinations of synchronous condensers and BESS converter control modes on the system stability is evaluated using a stability index-based approach that accounts for multiple operation scenarios. In this procedure, the system’s dynamic response to the reference disturbances (short-circuits in the Transmission and Distribution Network) is obtained via RMS dynamic simulation and is then analyzed to extract two stability indices (Nadir and Rocof). Such indices are computed for the synchronous generator speed and the grid electrical frequency (measured in different points using a PLL) and are later used as the basis for discussion and conclusion drawing. © Energynautics GmbH.

2024

Early plant disease diagnosis through handheld UV-Vis transmittance spectrometer with DD-SIMCA one-class classification and MCR-ALS bilinear decomposition

Autores
Reis-Pereira, M; Mazivila, SJ; Tavares, F; dos Santos, FN; Cunha, M;

Publicação
SMART AGRICULTURAL TECHNOLOGY

Abstract
A novel non-destructive analytical method for early diagnosis of two bacterial diseases, Pseudomonas syringae and Xanthomonas euvesicatoria, in tomato plants, using ultraviolet-visible (UV-Vis) transmittance spectroscopy and chemometric models, is developed. Plant-pathogen interactions caused tissue damage that generated non-linear data patterns compared to the control set (healthy samples), which challenges traditional discrimination models, even when employing non-linear discriminant approaches. Alternatively, an authentication task to conduct oneclass classification relying on a data-driven version of soft independent modeling of class analogy (DD-SIMCA) is a wise choice due to its quadratic approach, proper to deal with non-linear data. DD-SIMCA detached the target class (control healthy plant leaflet tissues) from all other samples (target class and non-target class of plant leaflet tissues inoculated with two bacteria, even before the manifestation of macroscopic lesions associated with the diseases) by capturing the main similarities within the samples of the target class through the full distance that acts as a classification analytical signal, reaching 100 % sensitivity in the training and validation sets. Multivariate curve resolution - alternating least-squares (MCR-ALS) constrained analysis allowed the description of the bacterial inoculation process on diseased tissues through pure spectral signatures. DD-SIMCA results indicate that non-target class of samples with higher proximity to the acceptance boundary suggested that they were at earlier stages of infection when compared to more distant ones, presenting lower full distance values. These findings reveal that a handheld UV-Vis transmittance spectrometer is sufficiently sensitive to be used in acquiring biological data with suitable chemometric models for early disease diagnosis and prompt intervention.

2024

Impact of EMG Signal Filters on Machine Learning Model Training: A Comparison with Clustering on Raw Signal

Autores
Barbosa, A; Ferreira, E; Grilo, V; Mattos, L; Lima, J;

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

Abstract
Our current society faces challenges in integrating individuals with disabilities, making this process difficult and painful. People with disabilities (PwD) are often mistakenly considered incapable due to the difficulties they face in daily tasks due to the lack of adapted means and tools. In this context, assistive technologies play a crucial role in improving the quality of life for these individuals. However, assistive technologies still have various limitations, making research in this area essential to enhance existing solutions and develop new approaches that meet individual needs, aiming to promote inclusion and equal opportunities. This paper presents a research project that focuses on the study of electromyography (EMG) signal processing generated by individuals who have undergone amputations. These signals are essential in assistive technologies, such as myoelectric prostheses. The study focuses on the impact of different filters and machine learning training methods on this processing. The results of this study have the potential to provide relevant findings for the development of more efficient assistive technologies. By understanding the processing of EMG signals and applying machine learning techniques, it is possible to improve the accuracy and response speed of prosthetics, increasing the functionality and naturalness of movements performed by users, as well as paving the way for the emergence of new technologies.

2024

Optimized Design Methodology and Maximum Efficiency Tracking Algorithm for Static IPT Chargers in Electric Vehicles

Autores
Viera, LAB; Pascoal, P; Rech, C;

Publicação
Eletrônica de Potência

Abstract
In recent years, technologies related to the electrification of transportation have attracted significant attention. Among these, wireless charging stands out, even facing numerous challenges concerning design and parameter optimization. Consequently, this article introduces a novel design methodology to improve the performance of inductive power transfer (IPT) systems for wireless charging applications in electric vehicles. The methodology considers operational limits of switches and passive components. By using a combination of Newton-Raphson and Particle Swarm Optimization (PSO) algorithms, the proposed approach efficiently determines both electrical and physical parameters of converters and coils to achieve maximum efficiency at a chosen operational point. Furthermore, a Maximum Efficiency Point Tracking (MEPT) algorithm is employed for optimal system operation. The proposed methodology is validated through experimental analysis using a 3.6 kW setup. Results demonstrate a power transfer efficiency around 89.4 %, while ensuring that current and voltage levels remain within safe operating areas for the components.

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