9,999 research outputs found

    Assessing the Effectiveness of Automated Emotion Recognition in Adults and Children for Clinical Investigation

    Get PDF
    Recent success stories in automated object or face recognition, partly fuelled by deep learning artificial neural network (ANN) architectures, has led to the advancement of biometric research platforms and, to some extent, the resurrection of Artificial Intelligence (AI). In line with this general trend, inter-disciplinary approaches have taken place to automate the recognition of emotions in adults or children for the benefit of various applications such as identification of children emotions prior to a clinical investigation. Within this context, it turns out that automating emotion recognition is far from being straight forward with several challenges arising for both science(e.g., methodology underpinned by psychology) and technology (e.g., iMotions biometric research platform). In this paper, we present a methodology, experiment and interesting findings, which raise the following research questions for the recognition of emotions and attention in humans: a) adequacy of well-established techniques such as the International Affective Picture System (IAPS), b) adequacy of state-of-the-art biometric research platforms, c) the extent to which emotional responses may be different among children or adults. Our findings and first attempts to answer some of these research questions, are all based on a mixed sample of adults and children, who took part in the experiment resulting into a statistical analysis of numerous variables. These are related with, both automatically and interactively, captured responses of participants to a sample of IAPS pictures

    Charm meson resonances in DPνD \to P \ell \nu decays

    Full text link
    Motivated by recent experimental results we reconsider semileptonic DPνD \to P \ell \nu_{\ell} decays within a model which combines heavy quark symmetry and properties of the chiral Lagrangian. We include excited charm meson states, some of them recently observed, in our Lagrangian and determine their impact on the charm meson semileptonic form factors. We find that the inclusion of excited charm meson states in the model leads to a rather good agreement with the experimental results on the q2q^2 shape of the F+(q2)F_+(q^2) form factor. We also calculate branching ratios for all DPνD \to P \ell \nu_{\ell} decays.Comment: 9 pages, 4 figures; minor corrections, added some discussion, version as publishe

    A New Method for Obtaining Binary Pulsar Distances and its Implications for Tests of General Relativity

    Get PDF
    We demonstrate how measuring orbital period derivatives can lead to more accurate distance estimates and transverse velocities for some nearby binary pulsars. In many cases this method will estimate distances more accurately than is possible by annual parallax, as the relative error decreases as t^-5/2. Unfortunately, distance uncertainties limit the degree to which nearby relativistic binary pulsars can be used for testing the general relativistic prediction of orbital period decay to a few percent. Nevertheless, the measured orbital period derivative of PSR B1534+12 agrees within the observational uncertainties with that predicted by general relativity if the proper-motion contribution is accounted for.Comment: 4 pages, latex, uuencoded compressed postscript + source, no figures, uses aaspptwo.sty and dec.sty, accepted for publication in ApJL, omitted reference now include

    Extending Elliptic Curve Chabauty to higher genus curves

    Full text link
    We give a generalization of the method of "Elliptic Curve Chabauty" to higher genus curves and their Jacobians. This method can sometimes be used in conjunction with covering techniques and a modified version of the Mordell-Weil sieve to provide a complete solution to the problem of determining the set of rational points of an algebraic curve YY.Comment: 24 page

    Are the distributions of Fast Radio Burst properties consistent with a cosmological population?

    Get PDF
    High time resolution radio surveys over the last few years have discovered a population of millisecond-duration transient bursts called Fast Radio Bursts (FRBs), which remain of unknown origin. FRBs exhibit dispersion consistent with propagation through a cold plasma and dispersion measures indicative of an origin at cosmological distances. In this paper we perform Monte Carlo simulations of a cosmological population of FRBs, based on assumptions consistent with observations of their energy distribution, their spatial density as a function of redshift and the properties of the interstellar and intergalactic media. We examine whether the dispersion measures, fluences, inferred redshifts, signal-to-noises and effective widths of known FRBs are consistent with a cosmological population. Statistical analyses indicate that at least 50 events at Parkes are required to distinguish between a constant co-moving FRB density, and a FRB density that evolves with redshift like the cosmological star formation rate density.Comment: 11 pages, 7 figures, 3 table

    Relativistic spin precession in the binary PSR J1141-6545

    Full text link
    PSR J1141-6545 is a precessing binary pulsar that has the rare potential to reveal the two-dimensional structure of a non-recycled pulsar emission cone. It has undergone 25deg\sim 25 \deg of relativistic spin precession in the 18\sim18 years since its discovery. In this paper, we present a detailed Bayesian analysis of the precessional evolution of the width of the total intensity profile, to understand the changes to the line-of-sight impact angle (β\beta) of the pulsar using four different physically motivated prior distribution models. Although we cannot statistically differentiate between the models with confidence, the temporal evolution of the linear and circular polarisations strongly argue that our line-of-sight crossed the magnetic pole around MJD 54000 and that only two models remain viable. For both these models, it appears likely that the pulsar will precess out of our line-of-sight in the next 353-5 years, assuming a simple beam geometry. Marginalising over β\beta suggests that the pulsar is a near-orthogonal rotator and provides the first polarization-independent estimate of the scale factor (A\mathbb{A}) that relates the pulsar beam opening angle (ρ\rho) to its rotational period (PP) as ρ=AP0.5\rho = \mathbb{A}P^{-0.5} : we find it to be >6 deg s0.5> 6 \rm~deg~s^{0.5} at 1.4 GHz with 99\% confidence. If all pulsars emit from opposite poles of a dipolar magnetic field with comparable brightness, we might expect to see evidence of an interpulse arising in PSR J1141-6545, unless the emission is patchy.Comment: Accepted for publication in Astrophysical Journal Letter

    M Dwarfs from Hubble Space Telescope Star Counts. IV

    Get PDF
    We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2 fields are newly analyzed. The method of maximum likelihood is applied to derive the luminosity function and the Galactic disk parameters. At first, we use a local color-magnitude relation and a locally determined mass-luminosity relation in our analysis. The results are consistent with those of previous work but with considerably reduced statistical errors. These small statistical errors motivate us to investigate the systematic uncertainties. Considering the metallicity gradient above the Galactic plane, we introduce a modified color-magnitude relation that is a function of Galactic height. The resultant M dwarf luminosity function has a shape similar to that derived using the local color-magnitude relation but with a higher peak value. The peak occurs at MV12M_V \sim 12 and the luminosity function drops sharply toward MV14M_V \sim 14. We then apply a height-dependent mass-luminosity function interpolated from theoretical models with different metallicities to calculate the mass function. Unlike the mass function obtained using local relations, which has a power-law index α=0.47\alpha = 0.47, the one derived from the height-dependent relations tends to be flat (α=0.10\alpha = -0.10). The resultant local surface density of disk M dwarfs (12.2 +/- 1.6 M_sun pc^{-2}) is somewhat smaller than the one obtained using local relations (14.3 +/- 1.3 M_sun pc^{-2}). Our measurement favors a short disk scale length, H = 2.75 +/- 0.16 (statistical) +/- 0.25 (systematic) kpc.Comment: 20 pages, 10 ps figures, accepted for publication in Ap

    Preventing and responding to depression, self-harm, and suicide in older people living in long term care settings: a systematic review

    Get PDF
    Abstract Objective: The well documented demographic shift to an aging population means that more people will in future be in need of long term residential care. Previous research has reported an increased risk of mental health issues and suicidal ideation among older people living in residential care settings. However, there is little information on the actual prevalence of depression, self-harm, and suicidal behavior in this population, how it is measured and how care homes respond to these issues. Method: This systematic review of international literature addressed three research questions relating to; the prevalence of mental health problems in this population; how they are identified and; how care homes try to prevent or respond to mental health issues. Results: Findings showed higher reported rates of depression and suicidal behavior in care home residents compared to matched age groups in the community, variation in the use of standardised measures across studies and, interventions almost exclusively focused on increasing staff knowledge about mental health but with an absence of involvement of older people themselves in these programmes. Conclusion: We discuss the implications of these findings in the context of addressing mental health difficulties experienced by older people in residential care and future research in this area
    corecore