Escola Superior de Tecnologia e Gestão
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- A 1.2V 900nW conductance converterPublication . Miranda, Nuno; Morais, RaulThis article describes a new electrical conductance converter method suitable for very low power applications, where energy constraints prevails over speed and measurement accuracy. Method idea gather voltage time integration and shopper stabilization techniques to process noisy low amplitude signals and to overcome severe limitations of weak inversion channel CMOS circuitry. Main features and tradeoffs are exploited. A 1.2V ASIC implementation on standard 0.35μm CMOS schematics is also presented. Post-layout simulations shows a total power consumption lower than 900nW including current source excitation inherent to the conductance measurement. Such low power consumption allows the measurement of several physical parameters on self-powered wireless networks.
- 12º Congresso Nacional de Mecânica Experimental - Livro de ResumosPublication . Capela, Carlos; Correia, Mário Simões; Ruben, Rui
- A 130 nm CMOS LNA for 30 GHz applicationsPublication . Ribeiro, R.; Moreira Mendes, Luís Miguel; Vaz, J. C.; Rosario, M. J.; Freire, J. C.This paper presents the design of a 30 GHz low noise amplifier in a 130 nm CMOS technology. The amplifier is based on a cascode topology. The circuit uses autotransformers in the input and output matching networks. This design approach eliminates the necessity of the use of source degeneration and allows obtaining an ultra compact LNA. The amplifier presents a forward gain (S21) of 7.4 dB at 30 GHz with a bandwidth of 10 GHz, input and output VSWRs better than 1.22:1 and a noise figure of 3.7 dB. The LNA is unconditionally stable and consumes only 7 mW when supplied with 1.2 V. The amplifier fits an area of 0.08 mm2, which is one of the smallest areas reported.
- 2-Hydroxy-4-methoxybenzaldehyde fromHemidesmus indicusis antagonistic toStaphylococcus epidermidisbiofilm formationPublication . Kannappan, Arunachalam; Durgadevi, Ravindran; Srinivasan, Ramanathan; Lagoa, Ricardo José Lucas; Packiavathy, Issac Abraham Sybiya Vasantha; Pandian, Shunmugiah Karutha; Ravi, Arumugam VeeraStaphylococcus epidermidis (SE) is an opportunistic nosocomial pathogen that accounts for recalcitrant device-related infections worldwide. Owing to the growing interest in plants and their secondary metabolites targeting bacterial adhesion, this study was intended to uncover the anti-biofilm potential of Hemidesmus indicus and its major constituent 2-hydroxy-4-methoxybenzaldehyde (HMB) against SE. The minimum biofilm inhibitory concentration (MBIC) of H. indicus root extract and HMB were found to be 500 and 250 µg ml−1, respectively. The results of time-dependent biofilm inhibition and mature biofilm disruption assays confirmed that HMB targets initial cell adhesion. Furthermore, interference by HMB in the expression of adhesin genes (icaA, aap and bhp) and biofilm components was associated with an increased susceptibility of SE to oxidative stress and antibiotics. To conclude, this study reports for the first time HMB as a potential drug against SE biofilms.
- 2ARTs – Decision Support System for Exercise and Diet Prescriptions in Cardiac Recovery PatientsPublication . Pereira, Andreia Alexandra Sousa; Martinho, Ricardo Filipe Gonçalves; Rijo, Rui Pedro Charters Lopes; Grilo, Carlos Fernando de AlmeidaThe global health care system is faced with a variety of complicated challenges, ranging from limited access and increasing expenses to an aging population causing increased pressure on healthcare systems. Healthcare professionals are seeking alternative approaches to provide fair access and sustain high-quality care for everyone as a result of these challenges. Patients have historically been restricted from accessing essential healthcare services due to traditional barriers like geographic distance, financial and resource limitations. Innovative solutions to these problems are starting to take shape, thanks to the growth of eHealth platforms that use technology to improve patient care. Through a comprehensive study of existing solutions in the healthcare domain, particularly in cardiology, we identified the need for a Decision Support System (DSS) that would empower physicians with valuable insights and facilitate informed physical and diet prescribing practices into Cardiac Rehabilitation Programmes (CRPs). The major goal of 2ARTs’ project is to create and implement a cardiac rehabilitation platform into a hospital's infrastructure. A key aspect of this platform is the integration of a decision support system designed to provide physicians with valuable information when prescribing individualized treatment prescriptions for each patient, minimizing the potential of human error. The DSS uses algorithms and predictive models to classify patients into distinct groups based on their features and medical history. This classification provides critical insights and additional knowledge to doctors, allowing them to make informed judgments regarding the most effective treatment options for each patient's cardiac rehabilitation journey. By using the power of data-driven analytics and machine learning, the DSS enables doctors to better understand each patient's needs and personalize treatment actions accordingly. In order to achieve the best possible results aligned with the goals of the project, a variety of approaches based on comprehensive studies were explored, specifically feature selection and feature reduction methods, where their performance metrics were evaluated, seeking the most effective solution. It was through this thorough analysis that Principal Component Analysis (PCA) emerged as the standout choice. PCA not only demonstrated superior outcomes in evaluation metrics, but also showcased excellent compatibility with the selected clustering algorithm along with the best results after an expert analysis. Moreover, with the analysis of the data types and features the dataset had, the K-Means algorithm produced the best results and was more adaptable to our dataset. We were able to identify useful insights and patterns within the data by employing both PCA and K-Means, opening the way for more accurate and informed decision-making in the 2ARTs project.
- 2ARTs: A Platform for Exercise Prescriptions in Cardiac Recovery PatientsPublication . Pereira, Andreia; Martinho, Ricardo; Pinto, Rui; Rijo, Rui; Grilo, CarlosDue to limited access, increasing costs and an ageing population, the global healthcare system faces significant coverage problems that call for innovative approaches. Health professionals are actively seeking alternative methods to provide care to an increasingly needy population, without increasing human effort and associated costs. eHealth platforms, which use technology to provide patient care, are emerging as transformative solutions for addressing these problems. This study is centered on the demand for a Decision Support System (DSS) in cardiology to enable doctors to prescribe individualized care inside Cardiac Rehabilitation Programmes (CRPs). The 2ARTs project’s main objective is to include a cardiac rehabilitation platform with a DSS within the hospital infrastructure. This DSS uses models to classify patients into different groups, delivering crucial information to assist with decisions regarding treatment. Regarding the DSS, Principal Component Analysis (PCA) emerged as a standout technique for dimensionality reduction, due to its interoperability with clustering algorithms and superior evaluation metrics. The most appropriate clustering technique was determined to be the K-means algorithm, which was supported by the experts analysis. In accordance with the goals of the 2ARTs project, this integration of PCA and K-means provides meaningful insights that improve reasoned decision-making.
- 2D and 3D Digital Image Correlation in Civil Engineering – Measurements in a Masonry WallPublication . Ramos, Tiago; Furtado, André; Eslami, Shayan; Alves, Sofia; Rodrigues, Hugo; Arêde, António; Tavares, Paulo J.; Moreira, P.M.G.P.Reinforced concrete structures play an important role in modern buildings, and common architectural designs often include RC frames strengthened with infill masonry panels. Due to their brittle nature, these components' failure and collapse have been subject of studies which can lead to proper structural diagnose and design in order to decrease their risk to human lives during seismic activities. Digital image correlation was used in two of these studies, in order to validate its ability for large specimens monitoring and future structural health monitoring applications. It enabled spatial reconstruction of the wall movement, characterization of its rigid body motion and measurement of both displacements and strain fields in in-plane and out-of-plane load applications. Data post-processing allowed the identification of common in-plane damages in the wall such as corner crushing and separation between infill and resistant structure.
- A 2D ray-tracing based model for wave propagation through forests at micro-and millimeter wave frequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo; Caldeirinha, Rafael F. S.This paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees’ re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- A 2D Ray-Tracing Based Model for Wave Propagation Through Forests at Micro-and Millimeter Wave FrequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo, Telmo Rui Carvalhinho Cunha, Telmo R.; Caldeirinha, RafaelThis paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees' re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- 2nd Leiria Young Scholars International Conference on Enterprise Law (Leiria-YSICEL). Proceedings.Publication . Cañete, Alejandro de Rosa; Panocca, Alfredo Jhunior Lazarte; Martínez, Irene Martínez; Castilho, Marília Vieira; Serrão, Marta; Zayas, Sandys Menoya; Conceição, Ana Filipa; Lambelho, Ana; Almeida, SusanaA II Young Scholars International Conference on Enterprise Law (YSICEL) pretendeu dar continuidade ao projeto que se iniciou com a primeira conferência, e que assenta em três pilares fundamentais: ser um espaço de acolhimento e de partilha para estudantes de mestrado e doutoramento e jovens investigadores (até 5 anos após a conclusão do doutoramento); promover a discussão sobre diferentes eixos do Direito Empresarial, como sejam o Direito dos Negócios, o Direito Laboral, o Direito da Insolvência, o Direito do Consumo, o Direito dos Contratos Comerciais ou da Propriedade Industrial e Direitos de Autor; criar uma conferência anual de qualidade, que possa trazer não só estudantes do Mestrado em Solicitadoria de Empresa da Escola Superior de Tecnologia e Gestão do Politécnico de Leiria, mas de todo o mundo. Estas são as atas do evento, que representam diferentes ordenamentos e realidades jurídicas.