4,268 research outputs found

    Introducing a Human Activity Recognition Dataset Gathered on Real-Life Conditions

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    Cursos e Congresos, C-155[Abstract] Human activity recognition (HAR) has garnered significant scientific interest in recent years. The widespread use of smartphones enabled convenient and cost-effective data collection, eliminating the need for additional wearables. Given that, this paper introduces a novel HAR dataset in which participants had freedom in choosing smartphone orientation and placement during activities, ensuring data variability. It also includes contributions from diverse individuals, reflecting unique smartphone usage habits. Moreover, it comprises measurements from accelerometer, gyroscope, magnetometer, and GPS, corresponding to one of four activities: inactive, active, walking, or driving. Unlike other datasets, the collected data in this study were obtained from smartphones used in real-life scenariosThis work was funded by CITIC is funded by the Xunta de Galicia through the collaboration agreement between the Consellería de Cultura, Educación, Formación Profesional e Universidades and the Galician universities for the reinforcement of the research centres of the Galician University System (CIGUS), Xunta de Galicia/FEDER-UE (ConectaPeme, GEMA: IN852A 2018/14), MINECO-AEI/FEDER-UE (Flatcity: TIN2016-77158-C4-3-R) and Xunta de Galicia/FEDER-UE (AXUDAS PARA A CONSOLIDACION E ESTRUTURACION DE UNIDADES DE INVESTIGACION COMPETITIVAS.GRC: ED431C 2017/58 and ED431C 2018/49).Xunta de Galicia; ED431C 2017/58Xunta de Galicia; ED431C 2018/4

    Quality-Based Conditional Processing in Multi-Biometrics: Application to Sensor Interoperability

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    As biometric technology is increasingly deployed, it will be common to replace parts of operational systems with newer designs. The cost and inconvenience of reacquiring enrolled users when a new vendor solution is incorporated makes this approach difficult and many applications will require to deal with information from different sources regularly. These interoperability problems can dramatically affect the performance of biometric systems and thus, they need to be overcome. Here, we describe and evaluate the ATVS-UAM fusion approach submitted to the quality-based evaluation of the 2007 BioSecure Multimodal Evaluation Campaign, whose aim was to compare fusion algorithms when biometric signals were generated using several biometric devices in mismatched conditions. Quality measures from the raw biometric data are available to allow system adjustment to changing quality conditions due to device changes. This system adjustment is referred to as quality-based conditional processing. The proposed fusion approach is based on linear logistic regression, in which fused scores tend to be log-likelihood-ratios. This allows the easy and efficient combination of matching scores from different devices assuming low dependence among modalities. In our system, quality information is used to switch between different system modules depending on the data source (the sensor in our case) and to reject channels with low quality data during the fusion. We compare our fusion approach to a set of rule-based fusion schemes over normalized scores. Results show that the proposed approach outperforms all the rule-based fusion schemes. We also show that with the quality-based channel rejection scheme, an overall improvement of 25% in the equal error rate is obtained.Comment: Published at IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Human

    In-Depth Assessment of the EU Member States’ Submissions for the Marine Strategy Framework Directive under articles 8, 9 and 10 on Hydrographical Conditions Descriptor 7

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    According to the Marine Strategy Framework Directive (MSFD), in 2012 Member States had to report on the initial assessment of their marine waters (art. 8), on the determination of good environmental status (art. 9) and on the establishment of environmental targets and associated indicators (art. 10). At the request of DG Environment, the Joint Research Centre of the European Commission has carried out an in-depth assessment (IDA) of the reporting done by Member States. This document presents the result of this IDA for MSFD Descriptor 7 (Permanent alteration of hydrographical conditions does not adversely affect marine ecosystems), carried out on the basis of reporting from the following Member States (MS): Belgium, Bulgaria, Cyprus, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Malta, Netherlands, Portugal, Romania, Slovenia, Spain, Sweden, United Kingdom. The aims of the IDA were: i) to evaluate comparability and coherence of methods and in particular their relation to the assessments under other European and international frames and the latest scientific evidence, ii) to provide recommendations for improved implementation of the MSFD in the second cycle (2018) and iii) to support the review and the possible revision of the Commission Decision (2010/477/EU). In this IDA document, relevant issues are addressed, followed by suggestions and potential actors regarding the MSFD Descriptor 7.JRC.H.1-Water Resource

    3D numerical simulation of slope-flexible system interaction using a mixed FEM-SPH model

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    Flexible membranes are light structures anchored to the ground that protect infrastructures or dwellings from rock or soil sliding. One alternative to design these structures is by using numerical simulations. However, very few models were found until date and most of them are in 2D and do not include all their components. This paper presents the development of a numerical model combining Finite Element Modelling (FEM) with Smooth Particle Hydrodynamics (SPH) formulation. Both cylindrical and spherical failure of the slope were simulated. One reference geometry of the slope was designed and a total of 21 slip circles were calculated considering different soil parameters, phreatic level position and drainage solutions. Four case studies were extracted from these scenarios and simulated using different dimensions of the components of the system. As a validation model, an experimental test that imitates the soil detachment and its retention by the steel membrane was successfully reproduced.The FORESEE project has received funding from the EuropeanUnion’s Horizon 2020 research and innovation program undergrant agreement No 769373

    The influence of sensor placement on in-situ ultrasound wave velocity measurement.

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    Ultrasound wave velocity was measured in 30 pieces of Spanish Scots pine (Pinus sylvestris L.), 90 x 140 mm in cross-section and 4 m long. Five different sensor placement arrangements were used: end to end (V0), face to opposite face, edge to opposite edge, face to same face and edge to same edge. The pieces were successively shortened to 3, 2 and 1 m, in order to obtain these velocities and their ratios to reference value V0 for different lengths and angles with respect to the piece axis for the crossed measurements. The velocity obtained in crossed measurements is lower than V0. A correction coefficient for crossed velocities is proposed, depending on the angle, to adjust them to the V0 benchmark. The velocities measured on a surface, are also lower than V0, and their ratio with respect to V0 is close to 0.97 for distances equal to or greater than 18 times the depth of the beam

    3D numerical simulation of slope-flexible system interaction using a mixed FEM-SPH model

    Get PDF
    Flexible membranes are light structures anchored to the ground that protect infrastructures or dwellings from rock or soil sliding. One alternative to design these structures is by using numerical simulations. However, very few models were found until date and most of them are in 2D and do not include all their components. This paper presents the development of a numerical model combining Finite Element Modelling (FEM) with Smooth Particle Hydrodynamics (SPH) formulation. Both cylindrical and spherical failure of the slope were simulated. One reference geometry of the slope was designed and a total of 21 slip circles were calculated considering different soil parameters, phreatic level position and drainage solutions. Four case studies were extracted from these scenarios and simulated using different dimensions of the components of the system. As a validation model, an experimental test that imitates the soil detachment and its retention by the steel membrane was successfully reproduced
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