40,289 research outputs found

    Non BPS topological defect associated with two coupled real field

    Full text link
    We investigate a stability equation involving two-component eigenfunctions which is associated with a potential model in terms of two coupled real scalar fields, which presents non BPS topological defect.Comment: Revtex, 6 pages, no figures. This work was presented in the XXII Brazilian National Meeting on Particles and Fields (October/2001), to appear at http://www.sbf.if.usp.b

    Rank-1 Tensor Approximation Methods and Application to Deflation

    Full text link
    Because of the attractiveness of the canonical polyadic (CP) tensor decomposition in various applications, several algorithms have been designed to compute it, but efficient ones are still lacking. Iterative deflation algorithms based on successive rank-1 approximations can be used to perform this task, since the latter are rather easy to compute. We first present an algebraic rank-1 approximation method that performs better than the standard higher-order singular value decomposition (HOSVD) for three-way tensors. Second, we propose a new iterative rank-1 approximation algorithm that improves any other rank-1 approximation method. Third, we describe a probabilistic framework allowing to study the convergence of deflation CP decomposition (DCPD) algorithms based on successive rank-1 approximations. A set of computer experiments then validates theoretical results and demonstrates the efficiency of DCPD algorithms compared to other ones

    Discriminação baseada no peso: representações sociais de internautas sobre a gordofobia

    Get PDF
    The concept of fat phobia has been usually used to define ways of discrimination towards overweight bodies. The present work aimed to know the social representations of fat phobia elaborated by internet users. A documental research was conducted based on internet comments on an article about fat phobia published by the Superinteressante magazine. Selected opinions comprised a textual corpus which was submitted to a lexical analysis through IRAMUTEQ, revealing five thematic classes: (i) "Health as discourse to justify discrimination", (ii) "Fat versus Slim: instituting differences", (iii) "Weight loss: reinforcement versus deconstruction of the standard", (iv) "Fat phobia: invention or reality?" and (v) "Fat phobia and the (in)appropriateness of affirmative actions". Anchored on the technical and scientific argument which affirms that obesity is an epidemic disease, the representations of internet users legitimized discrimination and prejudice processes against overweight people. Moreover, ironic propositions against quota policy for overweight people showed a dissatisfaction about the existence of affirmative actions that promote equality among social groups, ratifying the idea that the privileges cannot be granted to “inferior groups” or depreciated groups, and these groups, in order to be respected by society, should try to fit their bodies into the refined standard. In this context, aiming to make fat phobia an irrelevant topic, disqualifying the magazine’s approach on this topic, representational strategies directed to deny its existence by comparing suffering between groups or setting differences (fats x thins) was observed. Considering the lack of researches about discrimination against overweight in Brazil, other studies on this topic are suggested

    A Representation of the Virasoro Algebra via Wigner-Heisenberg Algebraic Technique to Bosonic Systems

    Full text link
    Using the Wigner-Heisenberg algebra for bosonic systems in connection with oscillators we find a new representation for the Virasoro algebra.Comment: Revised version. Revtex, 7 pages, no figures. This work was presented in the XXII Brazilian National Meeting on Particles and Fields (October/2001), to appear in Braz. J. of Phys., 33, 1 (2003

    US Current Account Deficit and Exchange Rate Tax

    Get PDF
    We examine the relationship between the US current account deficit, the international value of the dollar, and the dollar reserves of foreign central banks. We find that the international value of the dollar impacts the US current account and also that dollar depreciations are accompanied by reductions in the inflow of foreign reserves. The inflow reductions are indicative that the US levies an exchange rate tax on foreigners because the foreign stock of reserves loses value.US current account; exchange rate tax

    Statistical Mechanics Characterization of Neuronal Mosaics

    Full text link
    The spatial distribution of neuronal cells is an important requirement for achieving proper neuronal function in several parts of the nervous system of most animals. For instance, specific distribution of photoreceptors and related neuronal cells, particularly the ganglion cells, in mammal's retina is required in order to properly sample the projected scene. This work presents how two concepts from the areas of statistical mechanics and complex systems, namely the \emph{lacunarity} and the \emph{multiscale entropy} (i.e. the entropy calculated over progressively diffused representations of the cell mosaic), have allowed effective characterization of the spatial distribution of retinal cells.Comment: 3 pages, 1 figure, The following article has been submitted to Applied Physics Letters. If it is published, it will be found online at http://apl.aip.org
    corecore