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Efficient and Low-Cost 3D Structured Light System Based on a Modified Number-Theoretic Approach

  • Pribanic, Tomislav
  • Dzapo, Hrvoje
  • Salvi, Joaquim
3D scanning based on structured light (SL) has been proven to be a powerful tool to measure the three-dimensional shape of surfaces, especially in biomechanics. We define a set of conditions that an optimal SL strategy should fulfill in the case of static scenes and then we present an efficient solution based on improving the number-theoretic approach (NTA). The proposal is compared to the well-known Gray code (GC) plus phase shift (PS) technique and the original NTA, all satisfying the same set of conditions but obtaining significant improvements with our implementation. The technique is validated in biomechanical applications such as the scanning of a footprint left on a “foam box” typically made for that purpose, where one of the ultimate goals could be the production of a shoe insole
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Bringing Funds of Family Knowledge to school. The Living Morocco Project (“برغملا شيعلا”)

  • Saubich, Xènia
  • Esteban Guitart, Moisès
The purpose of the study, grounded in sociocultural theory, is to describe the funds of knowledge of a Moroccan family living in Catalonia (Spain) in order to document how teachers can use these funds of knowledge to make direct links between students' lives and classroom teaching. The funds of knowledge approach is based on a simple premise: regardless of any socio-economical and sociocultural "deficit" that people may or may not have all families accumulate bodies of beliefs, ideas, skills and abilities based on their experiences (in areas such as their occupation or their religion). The challenge consists in connecting these bodies of educational resources with teaching practice in order to connect the curriculum with students' lives. In doing so, qualitative research can be carried out using several techniques such as self portraits, self-definition tasks, assessment of family artefacts, documenting routines through photographs, or the analysis of a person's significant circle. The results in terms of teaching practices illustrate the variety of ways teachers can make connections between home and school in ways that assist learners in their academic development. In this article, we propose using the term funds of identity to complement the concept of funds of knowledge
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A noninvasive method for measuring the velocity of diffuse hydrothermal flow by tracking moving refractive index anomalies

  • Mittelstaedt, Eric
  • Davaille, Anne
  • Keken, Peter Edwin van‏
  • Grácias, Nuno Ricardo Estrela
  • Escartín, Javier
Diffuse flow velocimetry (DFV) is introduced as a new, noninvasive, optical technique for measuring the velocity of diffuse hydrothermal flow. The technique uses images of a motionless, random medium (e.g.,rocks) obtained through the lens of a moving refraction index anomaly (e.g., a hot upwelling). The method works in two stages. First, the changes in apparent background deformation are calculated using particle image velocimetry (PIV). The deformation vectors are determined by a cross correlation of pixel intensities across consecutive images. Second, the 2-D velocity field is calculated by cross correlating the deformation vectors between consecutive PIV calculations. The accuracy of the method is tested with laboratory and numerical experiments of a laminar, axisymmetric plume in fluids with both constant and temperaturedependent viscosity. Results show that average RMS errors are ∼5%–7% and are most accurate in regions of pervasive apparent background deformation which is commonly encountered in regions of diffuse hydrothermal flow. The method is applied to a 25 s video sequence of diffuse flow from a small fracture captured during the Bathyluck’09 cruise to the Lucky Strike hydrothermal field (September 2009). The velocities of the ∼10°C–15°C effluent reach ∼5.5 cm/s, in strong agreement with previous measurements of diffuse flow. DFV is found to be most accurate for approximately 2‐D flows where background objects have a small spatial scale, such as sand or gravel
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Repensando la formación inicial del profesorado para abordar el tratamiento a la diversidad cultural y lingüística en el aula = Rethinking initial teacher education for linguistic and cvltural diversity in the classroom

  • Coelho, Elizabeth
  • Oller, Judith
  • Serra i Bonet, Josep Maria
In recent decades, European educational systems are facing many challenges related to the treatment of cultural and linguistic diversity. The need to address this diversity requires new approaches to education; this in turn requires changes in the way we prepare teachers for the new reality they face in their classrooms. In this article we highlight some of the major problems that initial teacher training has to address in order to enable teachers to deal effectively, respectfully, and fairly with students whose linguistic and cultural background is different from their own. We also present several models for teacher education from Europe and North America based on clearly identified teacher competences for linguistic and cultural diversity, Los sistemas educativos europeos están afrontando en las últimas décadas numerosos retos relacionados con el tratamiento de la diversidad cultural y lingüística. La necesidad de afrontar dicha diversidad requiere de planteamientos globales dirigidos al conjunto de la población en aras de construir una sociedad cohesionada lingüística, social y culturalmente. En este artículo exponemos algunos de los principales problemas que afectan a la formación inicial del profesorado por lo que se refiere a la gestión y el tratamiento de la diversidad cultural y lingüística así como diferentes proyectos y enfoques que justamente tienen por objetivo establecer su formación competencial
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Una Interpretación de la psicología cultural: aplicaciones prácticas y principios teóricos

  • Esteban Guitart, Moisès
En el siguiente trabajo se exponen las bases teóricas y se ilustran algunas aplicaciones de una visión de la psicología cultural alrededor del concepto de “vivencia” y “geografía vital”. Según esta perspectiva, el desarrollo humano es el resultado de la participación en prácticas educativas a través de las cuales nos apropiamos de los “signos”, “tecnología cultural” o formas explícitas e implícitas de vida compartida. Se postulan dos supuestos y tres características. Los supuestos son que la experiencia psicológica se debe estudiar en el contexto o situación donde ésta se expresa y construye, siendo la “dieta cultural” el alimento de nuestra mente (nuestros recuerdos, temores, percepciones, sentimientos, pensamientos). Las características nos remiten a considerar la vivencia humana como unidad de análisis, en tanto realidad dinámica situada y distribuida y, finalmente, en tanto producto o resultado de la participación en particulares geografías o contextos de vida. Se esbozan aplicaciones en el campo de la psicología clínica y la rehabilitación, en el terreno socioeducativo y en el ámbito de las organizaciones o psicología del trabajo, como ejemplos de prácticas acordes a una psicología orientada culturalmente. Finalmente, se concluye considerando la necesidad de vertebrar la dimensión subjetiva, social y política de la cultura con el objetivo de ofrecer vías de comprensión ecológicas de la mente y conducta humana
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Ethnic Identity among Indigenous and Mestizos from Intercultural University of Chiapas = Identidad étnica entre los indígenas y los mestizos de la Universidad Intercultural de Chiapas

  • Esteban Guitart, Moisès
  • Nadal, Josep Maria
This study explored ethnic identity among 662 students (326 mestizos and 336 indigenous) from the Intercultural University of Chiapas (IUCh). Scholars suggest that ethnicity is more salient for ethnic minority adolescents than for adolescents who are members of the ethnic majority. The aims for this study were: 1) to determine the structure and validity of ethnic identity as measured by the Multigroup Ethnic Identity Measure in a sample of majority and minority ethnic groups from Intercultural University in Chiapas, and 2) to examine the variability of ethnic identity across ethnic groups. Specifically, it was hypothesized that the Multigroup Ethnic Identity Measure would show two factors, and that ethnic groups would differ on ethnic identity. The results supported the hypotheses, Este estudio explora la identidad étnica en un grupo de 662 estudiantes (326 mestizos y 336 indígenas) de la Universidad Intercultural de Chiapas (IUCh). Algunos autores señalan que la identidad étnica es más acusada en los adolescentes que pertenecen a una minoría étnica que en los que son miembros de una mayoría étnica. Los objetivos de este trabajo fueron: 1) determinar la estructura y la validez de la Medida de Identidad Étnica Multigrupo en una muestra de grupos étnicos mayoritarios y minoritarios de la Universidad Intercultural de Chiapas y 2) estudiar la variabilidad de la identidad étnica entre ambos grupos. Concretamente, se postuló que se pueden distinguir dos factores en la Medida de Identidad Étnica Multigrupo y que ambos grupos diferirían significativamente en su identidad étnica. Los resultados apoyaron estas hipótesis
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Trinocular System for 3D motion and Dense Stucture Estimation

  • Campos Dausà, Ricard
  • Ferrer Vila, Jordi
  • Villanueva Canalda, Miquel
  • Magí Carceller, Lluís
  • García Campos, Rafael
The relief of the seafloor is an important source of data for many scientists. In this paper we present an optical system to deal with underwater 3D reconstruction. This system is formed by three cameras that take images synchronously in a constant frame rate scheme. We use the images taken by these cameras to compute dense 3D reconstructions. We use Bundle Adjustment to estimate the motion of the trinocular rig. Given the path followed by the system, we get a dense map of the observed scene by registering the different dense local reconstructions in a unique and bigger one
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Small scale underwater change detection

  • Delaunoy, Olivier
  • Grácias, Nuno Ricardo Estrela
  • García Campos, Rafael
In this paper, we present a method to deal with the constraints of the underwater medium for finding changes between sequences of underwater images. One of the main problems of underwater medium for automatically detecting changes is the low altitude of the camera when taking pictures. This emphasise the parallax effect between the images as they are not taken exactly at the same position. In order to solve this problem, we are geometrically registering the images together taking into account the relief of the scene
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Identification of geometrically consistent interest points for 3D scene reconstruction

  • Nicosevici, Tudor
  • García Campos, Rafael
  • Grácias, Nuno Ricardo Estrela
We propose an algorithm that extracts image features that are consistent with the 3D structure of the scene. The features can be robustly tracked over multiple views and serve as vertices of planar patches that suitably represent scene surfaces, while reducing the redundancy in the description of 3D shapes. In other words, the extracted features will off er good tracking properties while providing the basis for 3D reconstruction with minimum model complexity
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An approach to costs and energy consumption in private urban Spanish Mediterranean landscapes from a simplified model in sprinkle irrigation

  • Arbat Pujolràs, Gerard
  • Pujol Planella, Joan
  • Pelegrí Sabater, Marc
  • Puig Bargués, Jaume
  • Duran i Ros, Miquel
  • Ramírez de Cartagena Bisbe, Francisco
The number of private gardens has increased in recent years, creating a more pleasant urban model, but not without having an environmental impact, including increased energy consumption, which is the focus of this study. The estimation of costs and energy consumption for the generic typology of private urban gardens is based on two simplifying assumptions: square geometry with surface areas from 25 to 500 m2 and hydraulic design with a single pipe. In total, eight sprinkler models have been considered, along with their possible working pressures, and 31 pumping units grouped into 5 series that adequately cover the range of required flow rates and pressures, resultin in 495 hydraulic designs repeated for two climatically different locations in the Spanish Mediterranean area (Girona and Elche). Mean total irrigation costs for the locality with lower water needs (Girona) and greater needs (Elche) were € 2,974 ha-¹ yr-¹ and € 3,383 ha-¹ yr-¹, respectively. Energy costs accounted for 11.4% of the total cost for the first location, and 23.0% for the second. While a suitable choice of the hydraulic elements of the setup is essential, as it may provide average energy savings of 77%, due to the low energy cost in relation to the cost of installation, the potential energy savings do not constitute a significant incentive for the irrigation system design. The low efficiency of the pumping units used in this type of garden is the biggest obstacle and constraint to achieving a high quality energy solution
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