4,357 research outputs found

    Crossmodal content binding in information-processing architectures

    Get PDF
    Operating in a physical context, an intelligent robot faces two fundamental problems. First, it needs to combine information from its different sensors to form a representation of the environment that is more complete than any of its sensors on its own could provide. Second, it needs to combine high-level representations (such as those for planning and dialogue) with its sensory information, to ensure that the interpretations of these symbolic representations are grounded in the situated context. Previous approaches to this problem have used techniques such as (low-level) information fusion, ontological reasoning, and (high-level) concept learning. This paper presents a framework in which these, and other approaches, can be combined to form a shared representation of the current state of the robot in relation to its environment and other agents. Preliminary results from an implemented system are presented to illustrate how the framework supports behaviours commonly required of an intelligent robot

    Nonperturbative Vertices in Supersymmetric Quantum Electrodynamics

    Get PDF
    We derive the complete set of supersymmetric Ward identities involving only two- and three- point proper vertices in supersymmetric QED. We also present the most general form of the proper vertices consistent with both the supersymmetric and U(1) gauge Ward identities. These vertices are the supersymmetric equivalent of the non supersymmetric Ball-Chiu vertices.Comment: seventeen pages late

    Systematic Review of Risk and Protective Factors for Externalizing Problems in Children Exposed to Intimate Partner Violence

    Get PDF
    Intimate partner violence (IPV) is a serious public health issue with innumerable costs to the victims, children, and families affected as well as society at large. The evidence is conclusive regarding a strong association between exposure to IPV and children’s externalizing problems. Moving forward, the next step is to enhance our understanding of risk and protective factors associated with these outcomes in order to tailor treatments to meet the needs of both parents and children. The databases Medline, PubMed, and PsyINFO were searched combining variations of the key words such as parent*, child*, mother, partner abuse, domestic abuse, spousal abuse, interpersonal violence, domestic violence, or intimate partner violence. This search were combined with child externalizing behaviors specifically conduct*, oppositional defiant disorder, externaliz*, aggress*, hyperactivity, and ADHD. A total of 31 studies from all three databases were reviewed following application of inclusion and exclusion criteria. The main findings were that child age and gender, callous–unemotional traits, cognitive appraisals, maternal mental health, and quality of parenting emerged as key mediating and moderating factors of the relationship between IPV exposure and child externalizing problems. These findings suggest that interventions provided to families exposed to IPV need to target both maternal and child risk factors in order to successfully reduce child externalizing problems

    Running coupling and fermion mass in strong coupling QED

    Full text link
    Simple toy model is used in order to exhibit the technique of extracting the non-perturbative information about Green's functions in Minkowski space. The effective charge and the dynamical electron mass are calculated in strong coupling 3+1 QED by solving the coupled Dyson-Schwinger equations for electron and photon propagators. The minimal Ball-Chiu vertex was used for simplicity and we impose the Landau gauge fixing on QED action. The solution obtained separately in Euclidean and Minkowski space were compared, the latter one was extracted with the help of spectral technique.Comment: 23 pages, 4 figures, v4: revised and extended version, one introductory section adde

    Vehicle Logo Recognition by Spatial-SIFT Combined with Logistic Regression

    Get PDF
    An efficient recognition framework requires both good feature representation and effective classification methods. This paper proposes such a framework based on a spatial Scale Invariant Feature Transform (SIFT) combined with a logistic regression classifier. The performance of the proposed framework is compared to that of state-of-the-art methods based on the Histogram of Orientation Gradients, SIFT features, Support Vector Machine and K-Nearest Neighbours classifiers. By testing with the largest vehicle logo data-set, it is shown that the proposed framework can achieve a classification accuracy of 99.93%, the best among all studied methods. Moreover, the proposed framework shows robustness when noise is added in both training and testing images

    Mean field exponents and small quark masses

    Full text link
    We demonstrate that the restoration of chiral symmetry at finite-T in a class of confining Dyson-Schwinger equation (DSE) models of QCD is a mean field transition, and that an accurate determination of the critical exponents using the chiral and thermal susceptibilities requires very small values of the current-quark mass: log_{10}(m/m_u) < -5. Other classes of DSE models characterised by qualitatively different interactions also exhibit a mean field transition. Incipient in this observation is the suggestion that mean field exponents are a result of the gap equation's fermion substructure and not of the interaction.Comment: 13 pages, 3 figures, REVTEX, epsfi

    Chiral symmetry breaking in dimensionally regularized nonperturbative quenched QED

    Get PDF
    In this paper we study dynamical chiral symmetry breaking in dimensionally regularized quenched QED within the context of Dyson-Schwinger equations. In D < 4 dimensions the theory has solutions which exhibit chiral symmetry breaking for all values of the coupling. To begin with, we study this phenomenon both numerically and, with some approximations, analytically within the rainbow approximation in the Landau gauge. In particular, we discuss how to extract the critical coupling alpha_c = pi/3 relevant in four dimensions from the D dimensional theory. We further present analytic results for the chirally symmetric solution obtained with the Curtis-Pennington vertex as well as numerical results for solutions exhibiting chiral symmetry breaking. For these we demonstrate that, using dimensional regularization, the extraction of the critical coupling relevant for this vertex is feasible. Initial results for this critical coupling are in agreement with cut-off based work within the currently achievable numerical precision.Comment: 24 pages, including 5 figures; submitted to Phys. Rev.

    Entometabolomics: applications of modern analytical techniques to insect studies

    Get PDF
    Metabolomic analyses can reveal associations between an organism's metabolome and further aspects of its phenotypic state, an attractive prospect for many life-sciences researchers. The metabolomic approach has been employed in some, but not many, insect study systems, starting in 1990 with the evaluation of the metabolic effects of parasitism on moth larvae. Metabolomics has now been applied to a variety of aspects of insect biology, including behaviour, infection, temperature stress responses, CO2 sedation, and bacteria–insect symbiosis. From a technical and reporting standpoint, these studies have adopted a range of approaches utilising established experimental methodologies. Here, we review current literature and evaluate the metabolomic approaches typically utilised by entomologists. We suggest that improvements can be made in several areas, including sampling procedures, the reduction in sampling and equipment variation, the use of sample extracts, statistical analyses, confirmation, and metabolite identification. Overall, it is clear that metabolomics can identify correlations between phenotypic states and underlying cellular metabolism that previous, more targeted, approaches are incapable of measuring. The unique combination of untargeted global analyses with high-resolution quantitative analyses results in a tool with great potential for future entomological investigations

    Intermittent aeration to improve wastewater treatment efficiency in pilot-scale constructed wetland

    Get PDF
    Forced aeration of horizontal subsurface flow constructed wetlands (HSSF CWs) is nowadays a recognized method to improve treatment efficiency, mainly in terms of ammonium removal. While numerous investigations have been reported testing constant aeration, scarce information can be found about the efficiency of intermittent aeration. This study aims at comparing continuous and intermittent aeration, establishing if there is an optimal regime that will increase treatment efficiency of HSSF CWs whilst minimizing the energy requirement. Full and intermittent aeration were tested in a pilot plant of three HSSF CWs (2.64 m2 each) fed with primary treated wastewater. One unit was fully aerated; one intermittently aerated (i.e. by setting a limit of 0.5 mg/L dissolved oxygen within the bed) with the remaining unit not aerated as a control. Results indicated that intermittent aeration was the most successful operating method. Indeed, the coexistence of aerobic and anoxic conditions promoted by the intermittent aeration resulted in the highest COD (66%), ammonium (99%) and total nitrogen (79%) removals. On the other hand, continuous aeration promotes ammonium removal (99%), but resulted in nitrate concentrations in the effluent of up to 27 mg/L. This study demonstrates the high potential of the intermittent aeration to increase wastewater treatment efficiency of CWs providing an extreme benefit in terms of the energy consumption
    corecore