153 research outputs found

    A Cluster-Matching-Based Method for Video Face Recognition

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    Face recognition systems are present in many modern solutions and thousands of applications in our daily lives. However, current solutions are not easily scalable, especially when it comes to the addition of new targeted people. We propose a cluster-matching-based approach for face recognition in video. In our approach, we use unsupervised learning to cluster the faces present in both the dataset and targeted videos selected for face recognition. Moreover, we design a cluster matching heuristic to associate clusters in both sets that is also capable of identifying when a face belongs to a non-registered person. Our method has achieved a recall of 99.435% and a precision of 99.131% in the task of video face recognition. Besides performing face recognition, it can also be used to determine the video segments where each person is present.Comment: 13 page

    MRI laxity assessment

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    Knee laxity, by definition, is a dynamic and multifactorial condition. MRI evaluation, due to its known capacity in achieving high soft tissue contrast (e.g., meniscus, synovia, ligaments, cartilage) and multiplanar joint assessment without ionizing radiation, has contributed to its popularity in the last decades. However, “traditional�? MRI studies provide static evaluation, thus requiring careful correlation to clinical findings, particularly when dealing with functional ligament stability. This work aims to describe the most important features of current MRI studies when dealing with anterior cruciate ligaments injuries, while also presenting the evolving possibilities of dynamic and objective MRI assessment of knee instability.(undefined

    Physical and morphological characterization of reactively magnetron sputtered TiN films

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    The present paper reports the influence of growth conditions on the properties of TiN thin films deposited by rf reactive magnetron sputtering in the low-pressure range. The effects of rf power at the Ti target and the negative bias voltage at the substrate in the morphology, structure, electrical resistivity and colour of the samples were studied in detail. X-Ray diffraction results showed that the delta-TiN phase (a(0) similar to 0.430 nm) is detected in all the samples. The sample prepared with grounded substrate revealed a lattice parameter close to the bulk value (0.424 nm), which is a consequence of a low stress state, due to the absence of ion bombardment. The sample deposited at 1000 W has a lattice parameter of 0.426 nm, close to that of the stress-free material (a(0) =0.424 nm), probably due to some stress relief. All films have a columnar-type structure, lying in the T and I zone of the Thornton Model. The resistivity of the TiN films is almost constant and close to 60 muOmega cm independently of the preparation conditions, except for the films deposited at 1000 W, p similar to 215 muOmega cm, and for the grounded sample, p similar to 153 muOmega cm. These values are probably due to cracks associated with stress relieves, in the first case, and the lack of ion bombardment that leads to films with lower density and higher number of defects in the second. No significant variations in colour were observed

    Alimentação, estilos de vida, prática desportiva, composição corporal e competência motora em crianças do ensino Pré-escolar e 1.º CEB (FORMIGA - Montemor-o-Velho)

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    The importance given in fitness according to the participants income

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    A participação em health clubs e academias de fitness tem ganho prevalência nos índices de prática desportiva em Portugal ao longo dos últimos anos, e os proprietários dos ginásios e health clubs competem, para atrair para as suas instalações, cada vez mais clientes. O conhecimento acerca do que os clientes esperam do serviço desempenha um papel-chave na adequação do serviço prestado em função do público-alvo. O objetivo deste estudo é caracterizar e comparar a importância atribuída à qualidade dos instrutores, qualidade dos serviços e motivos para a prática, segundo o rendimento líquido mensal. Participaram no estudo 560 praticantes de atividades de fitness, divididos em 7 grupos. Foi utilizado o questionário «Importância Atribuída no Fitness - Motivos de Prática, Qualidade do Serviço e Qualidade do Instrutor». Em termos gerais, os resultados mostram que os praticantes com maior rendimento apresentam valores mais altos de importância atribuída, nas três dimensões do questionário, particularmente nos Motivos de Prática. «Para melhorar a minha saúde em termos gerais» é mais importante para os clientes com rendimento superior (F = 2.440; p = 0.025; η2 = 0.027), como «para relaxar em termos mentais» (F = 3.815; p = 0.001; η2 = 0.042). Na dimensão Qualidade do Instrutor, «empatia» é mais relevante para clientes com maior rendimento (F = 2.196; p = 0.042; η2 = 0.024). Os proprietários de ginásios e health clubs podem utilizar estes resultados para adaptar o serviço às necessidades e expectativas dos clientes.info:eu-repo/semantics/publishedVersio

    Phosphorus sources residual effects on tifton 85 production and nutritive value cultivated in a tropical weathered soil

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    Acid reactions and low available phosphorus in tropical soils limit forage yield. The aim was to evaluate soil chemical characteristics pH, P and Mg, forage nutritive values, critical soil and plant P levels and the residual effect of each source. The experiment was in a greenhouse with a Rhodic Haplustox, loam texture. Experimental design was a 5 x 4 factorial with five replicates which phosphate fertilizers were triple superphosphate, reactive rock phosphates Gafsa and Arad, and fused magnesium phosphate powder and coarse, applied at rates of 30, 60, 90 and 120 mg kg-1 P and a control treatment without P. The effectiveness of rock phosphates increased due to their residual effect. The coarse fused magnesium phosphate resulted in the lowest efficiency. The P critical level in soil and plant were 18 mg kg-1 and 2.4 g kg-1, respectively. The increase of phosphorus rates provided an increase in crude protein content

    Deep learning-based detection of anthropometric landmarks in 3D infants head models

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    Deformational plagiocephaly (DP) is a cranial deformity characterized by an asymmetrical distortion of an infant's skull. The diagnosis and evaluation of DP are performed using cranial asymmetry indexes obtained from cranial measurements, which can be estimated using anthropometric landmarks of the infant's head. However, manual labeling of these landmarks is a time-consuming and tedious task, being also prone to observer variability. In this paper, a novel framework to automatically detect anthropometric landmarks of 3D infant's head models is described. The proposed method is divided into two stages: (i) unfolding of the 3D head model surface; and (ii) landmarks' detection through a deep learning strategy. In the first stage, an unfolding strategy is used to transform the 3D mesh of the head model to a flattened 2D version of it. From the flattened mesh, three 2D informational maps are generated using specific head characteristics. In the second stage, a deep learning strategy is used to detect the anthropometric landmarks in a 3-channel image constructed using the combination of informational maps. The proposed framework was validated in fifteen 3D synthetic models of infant's head, being achieved, in average for all landmarks, a mean distance error of 3.5 mm between the automatic detection and a manually constructed ground-truth. Moreover, the estimated cranial measurements were comparable to the ones obtained manually, without statistically significant differences between them for most of the indexes. The obtained results demonstrated the good performance of the proposed method, showing the potential of this framework in clinical practice.The present submission corresponds to original research work of the authors and has never been submitted elsewhere. Moreover, this work was funded by the project NORTE-01-0145-FEDER-024300, supported by Northern Portugal Regional Operational Programme (Norte2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). Moreover, this work has been also supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. Furthermore, the authors acknowledge FCT, Portugal, and the European Social Found, European Union, for funding support through the "Programa Operacional Capital Humano" (POCH) in the scope of the PhD grants SFRH/BD/136670/2018 (Helena R. Torres), SFRH/BD/136721/2018 (Bruno Oliveira), and SFRH/BD/131545/2017 (Fernando Veloso)

    Tree canopy enhances Collembola functional richness and diversity across typical habitats of the Gorongosa National Park (Mozambique)

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    ABSTRACT: The role of tree canopies in protecting soil functional diversity is essential for ecosystems threatened by the longer lasting periods of drought, which are predicted to increase in the southern afro-tropical region. Nonetheless, biodiversity inventories of soil mesofauna are scarce in afro-tropical ecosystems, even in emblematic and well-studied protected areas, such as the Gorongosa National Park (GNP). Understanding the interrelationships between tree canopies and soil fauna functional diversity can provide insightful information for future adaptive management to protect wildlife and ecosystem services in the GNP, in the context of climate change. Here we assessed collembolan functional type richness and functional diversity in the dry period and during the rainfall across major GNP habitat types: miombo forests, mixed forests, and open savanna/floodplains. Besides the significant positive influence of rainfall, habitat types also influenced functional type’ richness and diversity of collembolan life-forms. Environmental gradients across habitat types, namely the area of tree canopy cover and its indirect effect on soil local conditions (pH and nutrient availability), explained collembolan functional parameters. Calcium concentrations and soil alkalinity significantly enhanced collembolan functional type richness and functional diversity, respectively. Collembola survival across GNP habitats depended on the canopy buffering in the dry sampling period. These results highlight the key role of tree canopies in creating suitable microhabitat conditions supporting soil functional diversity and the sustainability of soil processes and ecosystem services in GNP.info:eu-repo/semantics/publishedVersio
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