386 research outputs found

    Edge- and Node-Disjoint Paths in P Systems

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    In this paper, we continue our development of algorithms used for topological network discovery. We present native P system versions of two fundamental problems in graph theory: finding the maximum number of edge- and node-disjoint paths between a source node and target node. We start from the standard depth-first-search maximum flow algorithms, but our approach is totally distributed, when initially no structural information is available and each P system cell has to even learn its immediate neighbors. For the node-disjoint version, our P system rules are designed to enforce node weight capacities (of one), in addition to edge capacities (of one), which are not readily available in the standard network flow algorithms.Comment: In Proceedings MeCBIC 2010, arXiv:1011.005

    Eye Status Based on Eyelid Detection: A Driver Assistance System

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    Fatigue and driver drowsiness monitoring is an important subject for designing driver assistance systems. The measurement of eye closure is a fundamental step for driver awareness detection. We propose a method which is based on eyelid detection and the measurement of the distance between the eyelids. First, the face and the eyes of the driver are localized. After extracting the eye region, the proposed algorithm detects eyelids and computes the percentage of eye closure. Experimental results are performed on the BioID database. Our comparisons show that the proposed method outperforms state-of-the-art methods

    Social Media in Southeast Italy

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    Why is social media in southeast Italy so predictable when it is used by such a range of different people? This book describes the impact of social media on the population of a town in the southern region of Puglia, Italy. Razvan Nicolescu spent 15 months living among the town’s residents, exploring what it means to be an individual on social media. He pays special attention to the ability of users to craft their appearance in relation to collective ideals, values and social positions, and how this feature of social media has, for the residents of the town, become a moral obligation

    New measures of the quality and of the reliability of fits applied to forward hadronic data at t=0

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    We develop five new statistical measures of the quality of fits, which we combine with the usual confidence level to determine the models which fit best all available data for total cross sections and for the real part of the forward hadronic amplitude.Comment: 7 pages, presented by J.R. Cudell on behalf of the COMPETE collaboration at the 6th workshop on non-perturbative QCD, American University of Paris, 5-9 June 200

    Analytic parametrizations of the non-perturbative Pomeron and QCD-inspired models

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    We consider several classes of analytic parametrizations of hadronic scattering amplitudes, and compare their predictions to all available forward data (proton- proton, antiproton-proton, pion-proton, kaon-proton, photon-proton, photon- photon, sigma-proton). Although these parametrizations are very close for energy larger than 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term ~(ln s)**2 enables one to extend the fit down to 4 GeV.Comment: 11 pages, 2 tables, Presented at the 9th Blois Workshop on Elastic and Diffractive Scattering, Pruhonice, Czech Republic, 9-15 June 200

    Analytic Amplitude Models for Forward Scattering

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    We report on fits of a large class of analytic amplitude models for forward scattering against the comprehensive data for all available reactions. To differentiate the goodness of the fits of many possible parametrizations to a large sample of data, we developed and used a set of quantitative indicators measuring statistical quality of the fits over and beyond the typical criterion of the X2/dof\Chi^2 /dof. These indicators favor models with a universal log2s log^2 s Pomeron term, which enables one to extend the fit down to s=4\sqrt s = 4 GeV.Comment: 13 pages, COMPETE Collaboration, talk presented at the 9th International Conference (Blois Workshop) on Elastic and Diffractive Scatterin

    Forward observables at RHIC, the Tevatron run II and the LHC

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    We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude (rho parameter) for present and future pp and pbar p colliders, and on total cross sections for gamma p -> hadrons at cosmic-ray energies and for gamma gamma -> hadrons up to sqrt(s)=1 TeV. These predictions are based on a study of many possible analytic parametrisations and invoke the current hadronic dataset at t=0. The uncertainties on total cross sections, including the systematic theoretical errors, reach 1% at RHIC, 3% at the Tevatron, and 10% at the LHC, whereas those on the rho parameter are respectively 10%, 17%, and 26%.Comment: 11 pages, 2 figures, LaTeX, presented at the Second International "Cetraro" Workshop & NATO Advanced Research Workshop "Diffraction 2002", Alushta, Crimea, Ukraine, August 31 - September 6, 200

    A natural fuzzyness of de Sitter space-time

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    A non-commutative structure for de Sitter spacetime is naturally introduced by replacing ("fuzzyfication") the classical variables of the bulk in terms of the dS analogs of the Pauli-Lubanski operators. The dimensionality of the fuzzy variables is determined by a Compton length and the commutative limit is recovered for distances much larger than the Compton distance. The choice of the Compton length determines different scenarios. In scenario I the Compton length is determined by the limiting Minkowski spacetime. A fuzzy dS in scenario I implies a lower bound (of the order of the Hubble mass) for the observed masses of all massive particles (including massive neutrinos) of spin s>0. In scenario II the Compton length is fixed in the de Sitter spacetime itself and grossly determines the number of finite elements ("pixels" or "granularity") of a de Sitter spacetime of a given curvature.Comment: 16 page

    Eye status based on eyelid detection a driver assistance system

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    Fatigue and driver drowsiness monitoring is an important subject for designing driver assistance systems. The measurement of eye closure is a fundamental step for driver awareness detection. We propose a method which is based on eyelid detection and the measurement of the distance between the eyelids. First, the face and the eyes of the driver are localized. After extracting the eye region, the proposed algorithm detects eyelids and computes the percentage of eye closure. Experimental results are performed on the BioID database. Our comparisons show that the proposed method outperforms state-of-the-art methods. Document type: Part of book or chapter of boo

    Spin asymmetries for elastic proton scattering and the spin dependent couplings of the Pomeron

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    This paper serves as a report on the large amount of analysis done in conjunction with the polarized proton program at RHIC. This comprises elastic scattering data of protons on protons in colliding beam or fixed target mode and proton beams on carbon targets. In addition to providing a model for the energy dependence of the analyzing power of elastic scattering needed for proton polarimetry, it also provides some significant information about the spin dependence of dominant Regge poles. Most notably, the data indicates that the Pomeron has a significant spin-flip coupling. This allows the exploration of the double spin flip asymmetry A_{NN} for which some data over a wide energy range is now available, along with a concrete realization of a proposed Odderon search.Comment: final reference modife
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