71 research outputs found

    Perceptually-Motivated Coded Apertures

    Get PDF
    Computational perception techniques are gaining increasing importance in all different steps of the imaging pipeline, from data capture to final display. The goal of these techniques is usually the same: to minimize visible errors in the final image. We present a method to compute coded apertures for defocus deblurring that takes into account human perception to obtain the optimal aperture pattern. We pose the problem of finding the optimal aperture as an optimization, and -to our knowledge- propose the first algorithm that makes use of perceptual quality metrics in its objective function. We explore the performance of different quality metrics for the design of such coded apertures, including the well-established SSIM, the state-of-the-art HDR-VDP-2, which features a comprehensive model of the HVS, as well as the L2 norm, previously used in related works.Our results outperform both conventional circular apertures and a previously published aperture pattern specifically designed for defocus deblurring [1], both in simulated and real scenarios (see Figures 1 and 2). The best apertures are obtained when a combination of the three metrics is used in the objective function. This work has been recently accepted for publication at the Computer Graphics Forum [2]

    Gender gap in STEM: a cross-sectional study of primary school students’ self-perception and test anxiety in mathematics

    Get PDF
    Contribution: Significant gender differences are observed on primary school students’ perception of self-efficacy and test anxiety in mathematics. Girls perceive themselves to be significantly worse than boys in mathematics and report higher test anxiety toward mathematics exams. Gender differences in self-efficacy become more pronounced as students grow up, and test anxiety increases for all students. However, the present study shows that teachers’ do not perceive differences in self-efficacy in mathematics between boys and girls. Background: The low presence of women in science, technology, engineering, and mathematics (STEM) might be explained by the attitude of young students toward mathematics. Different studies show that girls are less interested in STEM areas than boys during secondary school. A study on the reasons for this fact pointed out that the early years of education can provide a relevant insight to reverse the situation. Research Questions: Is there any age-dependent gender difference in primary school students in aspects related to mathematics? Are teachers aware of students’ perceptions? Methodology: This work presents a study of over 2000 primary school students (6–12 years old) and 200 teachers in Aragón (Spain). The study consists of a survey on aspects that influence the experience of female and male students with mathematics and Spanish language for comparison purposes and teacher’s awareness of students’ perception. Findings: The present study shows that during primary school, girls are more likely to experiment a negative attitude toward mathematics than boys as they grow up, and teachers may not perceive girls’ situation. La baja presencia de mujeres en ciencia, tecnología, la ingeniería y las matemáticas (STEM) podrían explicarse por la actitud de las niños y niñas hacia las matemáticas. Diferentes estudios muestran que las niñas están menos interesadas en las áreas STEM que niños cuando cursan educación secundaria. Además, un estudio sobre los motivos para este hecho señaló que los primeros años de educación podrían proporcionar una visión relevante para revertir la situación. Por ello, este trabajo parte de las siguientes preguntas de investigación, ¿Existe alguna diferencia de género que sea dependiente de la edad en estudiantes de educación primaria en aspectos relacionados con las matemáticas? ¿Conoce el profesorado la autopercepción de sus estudiantes? Las principales contribuciones de este trabajo son que las diferencias significativas de género se observan en la percepción de autoeficacia de los estudiantes de primaria y ansiedad ante los exámenes en matemáticas. Las niñas se perciben a sí mismas significativamente peor que los niños en matemáticas e indican mayor ansiedad ante los exámenes de matemáticas. Las diferencias de género en la autoeficacia se vuelven más pronunciada a medida que los estudiantes crecen, mientras que la ansiedad ante los exámenes aumenta para todos los estudiantes. Pese a estos resultados, el presente estudio muestra que los profesores no perciben diferencias en la autoeficacia en matemáticas entre niños y niñas. Este estudio se basa en las encuestas realizadas a más de 2000 escolares (6-12 años) y 200 profesores en Aragón (España). El estudio consiste en una encuesta a los estudiantes sobre aspectos que pueden influir en la experiencia de los niños y niñas con las matemáticas, así como con la lengua española para disponer de una materia que permita establecer comparaciones y una encuesta al profesor que incluye cuestiones sobre su percepción de los estudiantes. El principal hallazgo del estudio es que, durante la escuela primaria, es más probable que las niñas experimenten una actitud negativa hacia matemáticas que los niños a medida que crecen, y que los maestros pueden no ser conscientes de la situación de las niñas

    Larger visual changes compress time: The inverted effect of asemantic visual features on interval time perception; 35316292

    Get PDF
    Time perception is fluid and affected by manipulations to visual inputs. Previous literature shows that changes to low-level visual properties alter time judgments at the millisecond-level. At longer intervals, in the span of seconds and minutes, high-level cognitive effects (e.g., emotions, memories) elicited by visual inputs affect time perception, but these effects are confounded with semantic information in these inputs, and are therefore challenging to measure and control. In this work, we investigate the effect of asemantic visual properties (pure visual features devoid of emotional or semantic value) on interval time perception. Our experiments were conducted with binary and production tasks in both conventional and head-mounted displays, testing the effects of four different visual features (spatial luminance contrast, temporal frequency, field of view, and visual complexity). Our results reveal a consistent pattern: larger visual changes all shorten perceived time in intervals of up to 3min, remarkably contrary to their effect on millisecond-level perception. Our findings may help alter participants'' time perception, which can have broad real-world implications

    Evaluation of the passive safety in cars adapted with steering control devices for disabled drivers

    Full text link
    The purpose of this research is to analyse the influence of steering control devices for disabled people on passive safety. It is based on the advances made in the modelling and simulation of the driver position and in the suit verification test. The influence of these devices is studied through airbag deployment and/or its influence on driver safety. We characterise the different adaptations that are used in adapted cars that can be found mounted in vehicles in order to generate models that are verified by experimental test. A three-dimensional design software package was used to develop the model. The simulations were generated using a dynamic simulation program employing LS-DYNA finite elements. This program plots the geometry and assigns materials. The airbag is shaped, meshed and folded just as it is mounted in current vehicles. The thermodynamic model of expansion of gases is assigned, and the contact interfaces are defined. Static tests were carried out on the deployment of the airbag to contrast with and to validate the computational models and to measure the behaviour of the airbag when there are steering adaptations mounted in the vehicle. © 2011 Taylor & Francis.Masiá Vañó, J.; Eixerés Tomás, B.; Dols Ruiz, JF. (2011). Evaluation of the passive safety in cars adapted with steering control devices for disabled drivers. International Journal of Crashworthiness. 16(1):75-83. doi:10.1080/13588265.2010.514772S7583161Bedewi, N. E., Marzougui, D., & Motevalli, V. (1996). Evaluation of parameters affecting simulation of airbag deployment and interaction with occupants. International Journal of Crashworthiness, 1(4), 339-354. doi:10.1533/cras.1996.0025Chawla, A., Mukherjee, S., & Sharma, A. (2005). Development of FE meshes for folded airbags. International Journal of Crashworthiness, 10(3), 259-266. doi:10.1533/ijcr.2005.0343Cheng, Z., Rizer, A. L., & Pellettiere, J. A. (2003). Modeling and Simulation of OOP Occupant-Airbag Interaction. SAE Technical Paper Series. doi:10.4271/2003-01-0510Crandall, J. R., Bass, C. R., Pikey, W. D., Miller, H. J., Sikorski, J., & Wilkins, M. (1996). Thoracic response and injury with belt, driver side airbag, and force limited belt restraint systems. International Journal of Crashworthiness, 2(1), 119-132. doi:10.1533/cras.1997.0039Dalrymple, G. (1996). Effects of Assistive Steering Devices on Air Bag Deployment. SAE Technical Paper Series. doi:10.4271/960223Khan, M. U., & Moatamedi, M. (2008). A review of airbag test and analysis. International Journal of Crashworthiness, 13(1), 67-76. doi:10.1080/13588260701731674Khan, M. U., Moatamedi, M., Souli, M., & Zeguer, T. (2008). Multiphysics out of position airbag simulation. International Journal of Crashworthiness, 13(2), 159-166. doi:10.1080/13588260701788385Richert, J., Coutellier, D., Götz, C., & Eberle, W. (2007). Advanced smart airbags: The solution for real-life safety? International Journal of Crashworthiness, 12(2), 159-171. doi:10.1080/13588260701433461Ruff, C., Jost, T., & Eichberger, A. (2007). Simulation of an airbag deployment in out-of-position situations. Vehicle System Dynamics, 45(10), 953-967. doi:10.1080/0042311070153830

    Transcriptomic, biochemical and individual markers in transplanted Daphnia magna to characterize impacts in the field.

    Get PDF
    Daphnia magna individuals were transplanted across 12 sites from three Spanish river basins (Llobregat, Ebro, Jucar) showing different sources of pollution. Gene transcription, feeding and biochemical responses in the field were assessed and compared with those obtained in re-constituted water treatments spiked with organic eluates obtained from water samples collected at the same locations and sampling periods. Up to 166 trace contaminants were detected in water and classified by their mode of action into 45 groups that included metals, pharmaceuticals, pesticides, illicit drugs, and other industrial compounds. Physicochemical water parameters differentiated the three river basins with Llobregat having the highest levels of conductivity, metals and pharmaceuticals, followed by Ebro, whereas the Jucar river had the greatest levels of illicit drugs. D. magna grazing rates and cholinesterase activity responded similarly than the diversity of riparian benthic communities. Transcription patterns of 13 different genes encoding for general stress, metabolism and energy processes, molting and xenobiotic transporters corroborate phenotypic responses differentiated sites within and across river basins. Principal Component Analysis and Partial Least Square Projections to Latent Structures regression analyses indicated that measured in situ responses of most genes and biomarkers and that of benthic macroinvertebrate diversity indexes were affected by distinct environmental factors. Conductivity, suspended solids and fungicides were negatively related with the diversity of macroinvertebrates cholinesterase, and feeding responses. Gene transcripts of heat shock protein and metallothionein were positively related with 11 classes of organic contaminants and 6 metals. Gene transcripts related with signaling paths of molting and reproduction, sugar, protein and xenobiotic metabolism responded similarly in field and lab exposures and were related with high residue concentrations of analgesics, diuretics, psychiatric drugs, β blockers, illicit drugs, trizoles, bisphenol A, caffeine and pesticides. These results indicate that application of omic technologies in the field is a promising subject in water management

    Barrier Tissue Macrophages: Functional Adaptation to Environmental Challenges

    Get PDF
    Macrophages are found throughout the body, where they have crucial roles in tissue development, homeostasis and remodeling, as well as being sentinels of the innate immune system that can contribute to protective immunity and inflammation. Barrier tissues, such as the intestine, lung, skin and liver, are exposed constantly to the outside world, which places special demands on resident cell populations such as macrophages. Here we review the mounting evidence that although macrophages in different barrier tissues may be derived from distinct progenitors, their highly specific properties are shaped by the local environment, which allows them to adapt precisely to the needs of their anatomical niche. We discuss the properties of macrophages in steady-state barrier tissues, outline the factors that shape their differentiation and behavior and describe how macrophages change during protective immunity and inflammation

    International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures

    Get PDF
    Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries

    Effect of the anti-retroviral drug, rilpivirine, on human subcutaneous adipose cells and its nutritional management using quercetin

    Get PDF
    Rilpivirine, a recently developed drug of choice for initial treatment of HIV-1 infection, can greatly reduce HIV-related inflammation, but in turn, may be associated with adverse secondary effects, including disturbances in lipid metabolism and ultimately in adipose tissue distribution and function. In recent years, research findings on the benefits of anti-oxidant foods and supplements have been employed in counter-acting both oxidative stress as well as inflammation in order to reduce the adverse side effects of anti-retroviral therapy. One such natural flavonoid which possesses anti-inflammatory and anti-oxidative properties is quercetin. This study investigated the effect of quercetin in overcoming the side effects incurred due to rilpivirine administration. The results show substantial reduction in the accumulation of triglyceride levels in a dose- and time- dependent manner for adipose cells treated with either rilpivirine or quercetin alone and in combination, as evidenced by morphological pictures and quantitative measurement of triglycerides throughout the differentiation process. Levels of inflammatory markers such as resistin and IL-8 were increased as compared to the untreated cells. No significant changes in leptin were observed on treatment of adipose cells with rilpivirine alone and its levels were almost comparable to control. Levels of oxidative markers like superoxide dismutase, catalase and glutathione were also decreased. Treatment with quercetin showed a decrease in the inflammatory status and an increase in the oxidative status of adipose cells, thereby, exhibiting its anti-inflammatory and anti-oxidative properties. However, further assessment of lipid metabolism and adipose tissue function in patients administered with rilpivirine-based regimes is advisable considering that totally neutral effects of rilpivirine on lipid homeostasis cannot be anticipated from the current study in vitro. It is concluded that rilpivirine causes an anti-adipogenic and pro-inflammatory response pattern but only at high concentrations, whereas quercetin has been observed to decrease inflammation and restore the levels of anti-oxidant enzyme

    Passive safety evaluation in driving adapted vehicles

    No full text
    [EN] Driving a private vehicle represents nowadays one of the most viable ways by which disabled drivers can maintain their mobility and transport conditions. To do so it is necessary to adapt a vehicle to the user's residual capabilities. Nevertheless the technical aids installed in the vehicles must fulfill the same safety requirements as standard vehicles. This paper shows the results of a research project held at the Automobile Laboratory of the Technical University of Valencia (Spain), the main objective being to generate basic design criteria for improving the passive safety behaviour of the adapted vehicle under different impact conditions. The research project whose partial results are shown in this paper was developed by the Automobile Laboratory of the Technical University of Valencia (Spain), under the auspices of the Spanish Ministry of Science and Innovation (Ref. TRA2005-08649) during the years 2006–2008. Dols Ruiz, JF.; Masiá Vañó, J.; Eixerés Tomás, B. (2012). Passive Safety evaluation in driving adapted vehicles. International Journal of Vehicle Safety. 6(1):77-89. doi:10.1504/IJVS.2012.048534 S 77 89 6
    • …
    corecore