PV system with maximum power point tracking: modeling, simulation and experimental results

This paper focuses on the five parameters modeling, consisting on a current controlled generator, single-diode, a shunt and series resistances. Also, a simulation, identification of the parameters for a photovoltaic system and the maximum power point tracking based on VP„g„g is presented. The identification of parameters and the performance of the equivalent circuit model for a solar module simulation are validated by data measured on the photovoltaic system

Scintillation efficiency of liquid xenon for nuclear recoils with the energy down to 5 keV

The scintillation efficiency of liquid xenon for nuclear recoils has been measured to be nearly constant in the recoil energy range from 140 keV down to 5 keV. The average ratio of the efficiency for recoils to that for gamma-rays is found to be 0.19+-0.02.Comment: 13 pages, 5 figure

Impact of malocclusion, tooth loss and oral hygiene habits on quality of life in orthodontic patients: A cross-sectional study

We aimed to assess the impact of malocclusion on oral health-related quality of life (OHRQoL) in a sample composed of adolescents, younger adults and adults seeking orthodontic treatment. Participants were consecutively enrolled from January 2019 to March 2020. The oral health impact profile (OHIP-14) was used to measure the OHRQoL. The index of complexity, outcome and need (ICON) was used to assess malocclusion. Sociodemographic, medical, and clinical questionnaires were recorded. Statistical analyses were performed according as a function of sex and age range (15–30 or >30 years old). Linear and logistic regression models were applied to assess the association between OHIP-14 total score, malocclusion, and other relevant confounding variables. In a final sample of 93 participants (60 females and 33 males, aged 15 to 60 years), men reported significantly better OHRQoL (p = 0.005). Participants aged 30 years or older reported significantly worse OHRQoL (p = 0.042). OHIP-14 was significantly correlated with age (¿ = 0.259, p < 0.05) and the number of missing teeth (¿ = 0.369, p < 0.001). Multivariable regression showed OHIP-14 being associated with the number of missing teeth (B = 1.48, SE = 0.57, p < 0.05) and the presence of missing teeth (B = 1.38, SE = 0.65, p < 0.05). Malocclusion showed no association with OHRQoL. Age and the number of missing teeth may be key factors on self-perceived OHRQoL in adult patients seeking orthodontic treatment

Knee surgery complications related to biomaterials

Recent years have seen a growing interest in biomaterials and use of these materials in the clinical setting is increasing. Despite their advantages, they have also been cited as the source of specific complications and/or fail- ures. Problems such as screw breakage, tunnel enlargement, allergic or foreign body reactions, cyst and abscess formation, or even delayed migration of supposedly biodegradable screws/implants have been reported. This chapter aims to review the basic science and clinical experience with biomaterials currently employed in fixation devices for knee surgery. Information on the clinical implications of biodegradable screws is still limited. Surgeons tend to focus more on the emerging successes of innovations than on the complications and failures (publication bias) of older devices, making it difficult to reliably assess the incidence of such events. More- over, the complexity of possible reactions occurring in the human body cannot be reproduced under controlled laboratory conditions.Neverthe- less, surgeons and patients must be aware of both the advantages and the complications of these devices. Only in this way can informed choices be made, so that both parties are prepared to face and overcome the unde- sired complications, and the improvement of future implants can become a reality

Co-designed FreeRTOS deployed on FPGA

Most embedded systems are bound to real-time constraints. Two of the critical metrics presented in these systems are determinism and latency. Due to growing in complexity of embedded applications, real time operating systems (RTOS) are needed, not only to hide the increasingly complex hardware, but also to provide services to the system’s running tasks. Unfortunately, this new layer on an embedded system puts more pressure on the aforementioned metrics. One of the ways to cope with this problem is to offload RTOS run-time services to the hardware layer. This paper presents a hybrid hardware/software implementation of this technique upon the well known FreeRTOS, improving system’s latency and predictability, by migrating critical runtime services to hardware. The developed hardware accelerators were synthesized on a field-programmable gate array (FPGA), exploiting the point-to-point bus Fast Simplex Link (FSL) to interconnect to the Xilinx’s Microbaze soft-core processor.This work has been supported by FCT - Foundation for Science and Technology within the Project Scope: PEst-OE/EEI/UI0319/2014

A platform with combined environmental and physiological wireless data acquisition for AAL applications

http://isami2010.di.uminho.pt/Ambient Assisted Living is based on a set of technologies with the aim to provide an enhanced support to people’s daily life. One important field deals with the offer of new solutions for healthcare. Those solutions intend to improve the population quality of life and reduce costs associated with healthcare. Before that happens, new platforms, hardware and software, must be available in order to acquire and store the required signals, to process and extract information from those signals, and to detect a set of features required to fire alarms and/or electronic assistance. This paper presents a platform (hardware and software) that was designed to acquire data from a subject, or from a device, and send it to a remote hub. It was designed taking into account its size, power autonomy, and quality of sfor one day

Pre-training autoencoder for lung nodule malignancy assessment using CT images

Lung cancer late diagnosis has a large impact on the mortality rate numbers, leading to a very low five-year survival rate of 5%. This issue emphasises the importance of developing systems to support a diagnostic at earlier stages. Clinicians use Computed Tomography (CT) scans to assess the nodules and the likelihood of malignancy. Automatic solutions can help to make a faster and more accurate diagnosis, which is crucial for the early detection of lung cancer. Convolutional neural networks (CNN) based approaches have shown to provide a reliable feature extraction ability to detect the malignancy risk associated with pulmonary nodules. This type of approach requires a massive amount of data to model training, which usually represents a limitation in the biomedical field due to medical data privacy and security issues. Transfer learning (TL) methods have been widely explored in medical imaging applications, offering a solution to overcome problems related to the lack of training data publicly available. For the clinical annotations experts with a deep understanding of the complex physiological phenomena represented in the data are required, which represents a huge investment. In this direction, this work explored a TL method based on unsupervised learning achieved when training a Convolutional Autoencoder (CAE) using images in the same domain. For this, lung nodules from the Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) were extracted and used to train a CAE. Then, the encoder part was transferred, and the malignancy risk was assessed in a binary classification—benign and malignant lung nodules, achieving an Area Under the Curve (AUC) value of 0.936. To evaluate the reliability of this TL approach, the same architecture was trained from scratch and achieved an AUC value of 0.928. The results reported in this comparison suggested that the feature learning achieved when reconstructing the input with an encoder-decoder based architecture can be considered an useful knowledge that might allow overcoming labelling constraints.This work is financed by National Funds through the Portuguese funding agency, FCT—Fundação para a Ciência e a Tecnologia within project UIDB/50014/2020

Manejo de irrigação para cafeeiros propagador por embriogênese somática

A irrigação do cafeeiro tem se tornado prática cada vez mais frequente e necessária, uma vez que a cafeicultura tem migrado para regiões antes consideradas não aptas ao cultivo do café. Mesmo em regiões consideradas aptas quanto a deficiência hídrica como a região do sul de Minas, o uso da irrigação vem se tornando prática crescente. Porém, ainda são escassos os estudos sobre a adaptabilidade de cafeeiros provenientes de embriogênese somática a irrigação em condições de campo. Dessa maneira o objetivo desse trabalho foi determinar os níveis adequados de reposição de água de irrigação para cafeeiros oriundos de mudas propagadas por embriogênese somática. O experimento foi instalado no setor de cafeicultura da Universidade Federal de Lavras, onde foram plantadas mudas de Siriema, clone 03 resistente a ferrugem e ao bicho mineiro. O experimento foi instalado em blocos casualizados, com quatro repetições e seis tratamentos. Os tratamentos foram compostos de seis lâminas de irrigação baseadas em frações do Kc, constituídas de 0,4 (T2); 0,7 (T3); 1,0 (T4); 1,3 (T5); 1,6 (T6) e não irrigado (T1). Sendo aplicadas 75,22; 131,63; 188,05; 244,46 e 300,88 mm respectivamente aos tratamentos T2, T3, T4, T5 e T6. Foram avaliados durante o período de um ano após a implantação da lavoura a altura e o diâmetro de copa dos cafeeiros, sendo a parcela constituída por oito plantas e avaliada as seis plantas centrais. Os resultados mostraram que as parcelas irrigadas apresentaram aumento do Índice de área foliar (IAF) até uma lâmina máxima de 225,25 mm, correspondente a fração de 1,2 do Kc. Este crescimento correspondeu a 1,46 m².m-2 do IAF, cerca de 43,13% a mais que as parcelas não irrigadas