2,176 research outputs found

    Preface

    Get PDF
    The Tenth Labour, Employment and Work (LEW) Conference, which took place on Thursday, November 21st, and Friday, November 22nd, 2002, was, for the first time in the history of this Conference, held at Victoria University of Wellington's Downtown Campus. Papers were invited on all topics related to labour, employment and work in New Zealand. In addition, a special invitation was sent out prior to the Conference to those conducting research on the impact of the Employment Relations Act 2000, ageing of the labour force, the future of work in New Zealand, regional issues in labour, employment and work, and new employment institutions

    Field Theory And Second Renormalization Group For Multifractals In Percolation

    Full text link
    The field-theory for multifractals in percolation is reformulated in such a way that multifractal exponents clearly appear as eigenvalues of a second renormalization group. The first renormalization group describes geometrical properties of percolation clusters, while the second-one describes electrical properties, including noise cumulants. In this context, multifractal exponents are associated with symmetry-breaking fields in replica space. This provides an explanation for their observability. It is suggested that multifractal exponents are ''dominant'' instead of ''relevant'' since there exists an arbitrary scale factor which can change their sign from positive to negative without changing the Physics of the problem.Comment: RevTex, 10 page

    Diluted Networks of Nonlinear Resistors and Fractal Dimensions of Percolation Clusters

    Full text link
    We study random networks of nonlinear resistors, which obey a generalized Ohm's law, VIrV\sim I^r. Our renormalized field theory, which thrives on an interpretation of the involved Feynman Diagrams as being resistor networks themselves, is presented in detail. By considering distinct values of the nonlinearity r, we calculate several fractal dimensions characterizing percolation clusters. For the dimension associated with the red bonds we show that dred=1/νd_{\scriptsize red} = 1/\nu at least to order {\sl O} (\epsilon^4), with ν\nu being the correlation length exponent, and ϵ=6d\epsilon = 6-d, where d denotes the spatial dimension. This result agrees with a rigorous one by Coniglio. Our result for the chemical distance, d_{\scriptsize min} = 2 - \epsilon /6 - [ 937/588 + 45/49 (\ln 2 -9/10 \ln 3)] (\epsilon /6)^2 + {\sl O} (\epsilon^3) verifies a previous calculation by one of us. For the backbone dimension we find D_B = 2 + \epsilon /21 - 172 \epsilon^2 /9261 + 2 (- 74639 + 22680 \zeta (3))\epsilon^3 /4084101 + {\sl O} (\epsilon^4), where ζ(3)=1.202057...\zeta (3) = 1.202057..., in agreement to second order in ϵ\epsilon with a two-loop calculation by Harris and Lubensky.Comment: 29 pages, 7 figure

    Critical Exponents for Diluted Resistor Networks

    Full text link
    An approach by Stephen is used to investigate the critical properties of randomly diluted resistor networks near the percolation threshold by means of renormalized field theory. We reformulate an existing field theory by Harris and Lubensky. By a decomposition of the principal Feynman diagrams we obtain a type of diagrams which again can be interpreted as resistor networks. This new interpretation provides for an alternative way of evaluating the Feynman diagrams for random resistor networks. We calculate the resistance crossover exponent ϕ\phi up to second order in ϵ=6d\epsilon=6-d, where dd is the spatial dimension. Our result ϕ=1+ϵ/42+4ϵ2/3087\phi=1+\epsilon /42 +4\epsilon^2 /3087 verifies a previous calculation by Lubensky and Wang, which itself was based on the Potts--model formulation of the random resistor network.Comment: 27 pages, 14 figure

    Neural Correlates of Verb Argument Structure Processing

    Get PDF
    This fMRI study examined the neural correlates of verbs controlled for argument structure complexity and nouns controlled for semantic class. Participants showed activation of left inferior frontal and posterior temporal regions for verbs as compared to nouns, and more widespread, non-perisylvian activation for nouns as compared to verbs. Verbs with more complex argument structure entries activated posterior temporal regions bilaterally. These findings suggest that posterior perisylvian regions are crucial for processing the argument structure information associated with verbs

    Noisy random resistor networks: renormalized field theory for the multifractal moments of the current distribution

    Full text link
    We study the multifractal moments of the current distribution in randomly diluted resistor networks near the percolation treshold. When an external current is applied between to terminals xx and xx^\prime of the network, the llth multifractal moment scales as MI(l)(x,x)xxψl/νM_I^{(l)} (x, x^\prime) \sim | x - x^\prime |^{\psi_l /\nu}, where ν\nu is the correlation length exponent of the isotropic percolation universality class. By applying our concept of master operators [Europhys. Lett. {\bf 51}, 539 (2000)] we calculate the family of multifractal exponents {ψl}\{\psi_l \} for l0l \geq 0 to two-loop order. We find that our result is in good agreement with numerical data for three dimensions.Comment: 30 pages, 6 figure

    Studying neuroanatomy using MRI

    Get PDF
    The study of neuroanatomy using imaging enables key insights into how our brains function, are shaped by genes and environment, and change with development, aging, and disease. Developments in MRI acquisition, image processing, and data modelling have been key to these advances. However, MRI provides an indirect measurement of the biological signals we aim to investigate. Thus, artifacts and key questions of correct interpretation can confound the readouts provided by anatomical MRI. In this review we provide an overview of the methods for measuring macro- and mesoscopic structure and inferring microstructural properties; we also describe key artefacts and confounds that can lead to incorrect conclusions. Ultimately, we believe that, though methods need to improve and caution is required in its interpretation, structural MRI continues to have great promise in furthering our understanding of how the brain works

    Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron

    Get PDF
    The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of s=1.96\sqrt s =1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is AFBttˉ=0.128±0.025A_{\mathrm{FB}}^{t\bar{t}} = 0.128 \pm 0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions
    corecore