8,353 research outputs found

    Environmental psychology must better integrate local cultural and sociodemographic context to inform conservation

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    This is the final version. Available on open access from Wiley via the DOI in this recor

    A 4D Light-Field Dataset and CNN Architectures for Material Recognition

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    We introduce a new light-field dataset of materials, and take advantage of the recent success of deep learning to perform material recognition on the 4D light-field. Our dataset contains 12 material categories, each with 100 images taken with a Lytro Illum, from which we extract about 30,000 patches in total. To the best of our knowledge, this is the first mid-size dataset for light-field images. Our main goal is to investigate whether the additional information in a light-field (such as multiple sub-aperture views and view-dependent reflectance effects) can aid material recognition. Since recognition networks have not been trained on 4D images before, we propose and compare several novel CNN architectures to train on light-field images. In our experiments, the best performing CNN architecture achieves a 7% boost compared with 2D image classification (70% to 77%). These results constitute important baselines that can spur further research in the use of CNNs for light-field applications. Upon publication, our dataset also enables other novel applications of light-fields, including object detection, image segmentation and view interpolation.Comment: European Conference on Computer Vision (ECCV) 201

    Boundaries of Disk-like Self-affine Tiles

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    Let T:=T(A,D)T:= T(A, {\mathcal D}) be a disk-like self-affine tile generated by an integral expanding matrix AA and a consecutive collinear digit set D{\mathcal D}, and let f(x)=x2+px+qf(x)=x^{2}+px+q be the characteristic polynomial of AA. In the paper, we identify the boundary T\partial T with a sofic system by constructing a neighbor graph and derive equivalent conditions for the pair (A,D)(A,{\mathcal D}) to be a number system. Moreover, by using the graph-directed construction and a device of pseudo-norm ω\omega, we find the generalized Hausdorff dimension dimHω(T)=2logρ(M)/logq\dim_H^{\omega} (\partial T)=2\log \rho(M)/\log |q| where ρ(M)\rho(M) is the spectral radius of certain contact matrix MM. Especially, when AA is a similarity, we obtain the standard Hausdorff dimension dimH(T)=2logρ/logq\dim_H (\partial T)=2\log \rho/\log |q| where ρ\rho is the largest positive zero of the cubic polynomial x3(p1)x2(qp)xqx^{3}-(|p|-1)x^{2}-(|q|-|p|)x-|q|, which is simpler than the known result.Comment: 26 pages, 11 figure

    Suppression of photoconductivity by magnetic field in epitaxial manganite thin films

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    The erasure of photoinduced resistance (PR) by the magnetic field was investigated in manganite films. The PR was significantly suppressed when a magnetic field was introduced at low temperature. The decrease (or increase) of PR with increment of magnetic field was observed in ferromagnetic (or paramagnetic) phases of films, respectively. Our results are suggested to be the coaction of two effects under magnetic fields: (i) the reorientation of domains and spin directions of photoexcited carriers and (ii) electrons trapped around oxygen vacancies released and recombined with majority carriers in films. The interplay of the external fields is a good demonstration of the strong coupling between spins and charges in colossal magnetoresistance materials. © 2012 American Institute of Physics.published_or_final_versio

    Reducing Energy Consumption and Improving Comfort by Retrofitting Residential Buildings in the Hot Summer and Cold Winter Zone of China

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    China's Hot Summer and Cold Winter zone, with a 550 million population, accounts for 45% of China's building energy consumption; as such, building retrofits could offer substantial energy savings. This paper presents results from a dynamic thermal modeling study of a typical urban multistory residential building under three types of air conditioning (A/C) operating schedules. Seven energy-saving retrofit measures (external wall insulation, roof insulation, double-glazing, air infiltration control, window shading, communal staircase design, and energy-efficient A/C) were evaluated, and the retrofit strategy with the highest annual energy savings and lowest thermal discomfort was identified. This retrofit strategy was subsequently evaluated for other flats (apartments) with different orientations and positions in the typical building. The annual space-conditioning energy could be reduced by 59%-68%, depending on the flat location, orientation and A/C operating schedule. The findings were then scaled up to estimate the potential energy savings in the city of Chongqing. More than 320 multistory residential buildings were represented by 12 archetypes. Space-conditioning energy consumption was reduced by up to 58% (18.8 TWh). This work provides evidence of the potential energy savings of city-scale retrofit that could aid China in reducing building energy consumption and achieving net-zero carbon emissions by 2050

    Vibration suppression and angle tracking of a fire-rescue ladder

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    This paper mainly considers vibration suppression and angle tracking of a fire-rescue ladder system. The dynamical model is regarded as a segmented Euler–Bernoulli beam with gravity and tip mass, described by a set of motion equations and boundary conditions. Based on the nonlinear Euler–Bernoulli beam model, two active boundary controllers are proposed to achieve the control objectives. The elastic deflection and the angular error in the closed-loop system are proven to converge exponentially to a small neighborhood of zero. Numerical simulations based on finite difference method verify the effectiveness and the ascendancy of active boundary controllers

    Field-testing of the revised, draft South African Paediatric Food-Based Dietary Guidelines amongst mothers/caregivers of children aged 0–12 months in the Breede Valley sub-district, Western Cape province, South Africa

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    Objectives: To assess the appropriateness and understanding of the revised, draft South African Paediatric Food-Based Dietary Guidelines (SA-PFBDGs) amongst mothers/caregivers of children aged 0–12 months. Exposure to guidelines with similar messages, barriers and enablers to following of the guidelines were also assessed. Design: Qualitative data were collected from 14 focus-group discussions (FGDs), conducted in isiXhosa (n = 5), English (n = 4) and Afrikaans (n = 5), totalling 73 mother/caregiver participants. Setting: Worcester, Breede Valley sub-district, Western Cape province. Subjects: The study population included mothers/caregivers who were older than 18 years. Results: The majority of participants had previous exposure to variations of messages similar to the revised, draft SA-PFBDGs. Health platforms and practitioners (community health centres, antenatal classes, nurses, doctors) and social networks and platforms (family, magazines, radio) were mentioned as primary sources of information. Barriers to following the messages included: inconsistent messages (mainly communicated by healthcare workers), contrasting beliefs and cultural/family practices, limited physical and financial access to resources, poor social support structures and the psycho-social and physical demands of raising a child. Conclusion: The revised, draft SA-PFBDGs for the age range 0–12 months have been field-tested in English, Afrikaans and isiXhosa. The messages in some of the revised, draft SA-PFBDGs were not understood by the participants, indicating that a degree of rewording should be considered to facilitate understanding of the guidelines by the public. The National Department of Health should consider the findings of this study, and use these standardised message/s to optimise infant and young child feeding

    Probing Shadowed Nuclear Sea with Massive Gauge Bosons in the Future Heavy-Ion Collisions

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    The production of the massive bosons Z0Z^0 and W±W^{\pm} could provide an excellent tool to study cold nuclear matter effects and the modifications of nuclear parton distribution functions (nPDFs) relative to parton distribution functions (PDFs) of a free proton in high energy nuclear reactions at the LHC as well as in heavy-ion collisions (HIC) with much higher center-of mass energies available in the future colliders. In this paper we calculate the rapidity and transverse momentum distributions of the vector boson and their nuclear modification factors in p+Pb collisions at sNN=63\sqrt{s_{NN}}=63TeV and in Pb+Pb collisions at sNN=39\sqrt{s_{NN}}=39TeV in the framework of perturbative QCD by utilizing three parametrization sets of nPDFs: EPS09, DSSZ and nCTEQ. It is found that in heavy-ion collisions at such high colliding energies, both the rapidity distribution and the transverse momentum spectrum of vector bosons are considerably suppressed in wide kinematic regions with respect to p+p reactions due to large nuclear shadowing effect. We demonstrate that in the massive vector boson productions processes with sea quarks in the initial-state may give more contributions than those with valence quarks in the initial-state, therefore in future heavy-ion collisions the isospin effect is less pronounced and the charge asymmetry of W boson will be reduced significantly as compared to that at the LHC. Large difference between results with nCTEQ and results with EPS09 and DSSZ is observed in nuclear modifications of both rapidity and pTp_T distributions of Z0Z^0 and WW in the future HIC.Comment: 13 pages, 21 figures, version accepted for publication in Eur. Phys. J.

    FMRI resting slow fluctuations correlate with the activity of fast cortico-cortical physiological connections

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    Recording of slow spontaneous fluctuations at rest using functional magnetic resonance imaging (fMRI) allows distinct long-range cortical networks to be identified. The neuronal basis of connectivity as assessed by resting-state fMRI still needs to be fully clarified, considering that these signals are an indirect measure of neuronal activity, reflecting slow local variations in de-oxyhaemoglobin concentration. Here, we combined fMRI with multifocal transcranial magnetic stimulation (TMS), a technique that allows the investigation of the causal neurophysiological interactions occurring in specific cortico-cortical connections. We investigated whether the physiological properties of parieto-frontal circuits mapped with short-latency multifocal TMS at rest may have some relationship with the resting-state fMRI measures of specific resting-state functional networks (RSNs). Results showed that the activity of fast cortico-cortical physiological interactions occurring in the millisecond range correlated selectively with the coupling of fMRI slow oscillations within the same cortical areas that form part of the dorsal attention network, i.e., the attention system believed to be involved in reorientation of attention. We conclude that resting-state fMRI ongoing slow fluctuations likely reflect the interaction of underlying physiological cortico-cortical connections
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