17,307 research outputs found

    Event-by-Event Search for Charged Neutral Fluctuations in Pb - Pb Collisions at 158-A-GeV

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    Results from the analysis of data obtained from the WA98 experiment at the CERN SPS have been presented. Some events have been filtered which show photon excess in limited η−ϕ\eta-\phi zones within the overlap region of the charged particle and photon multiplicity detectors.Comment: 6 pages, 4 figure

    Early Recognition of Human Activities from First-Person Videos Using Onset Representations

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    In this paper, we propose a methodology for early recognition of human activities from videos taken with a first-person viewpoint. Early recognition, which is also known as activity prediction, is an ability to infer an ongoing activity at its early stage. We present an algorithm to perform recognition of activities targeted at the camera from streaming videos, making the system to predict intended activities of the interacting person and avoid harmful events before they actually happen. We introduce the novel concept of 'onset' that efficiently summarizes pre-activity observations, and design an approach to consider event history in addition to ongoing video observation for early first-person recognition of activities. We propose to represent onset using cascade histograms of time series gradients, and we describe a novel algorithmic setup to take advantage of onset for early recognition of activities. The experimental results clearly illustrate that the proposed concept of onset enables better/earlier recognition of human activities from first-person videos

    Empirical Evaluation of the Parallel Distribution Sweeping Framework on Multicore Architectures

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    In this paper, we perform an empirical evaluation of the Parallel External Memory (PEM) model in the context of geometric problems. In particular, we implement the parallel distribution sweeping framework of Ajwani, Sitchinava and Zeh to solve batched 1-dimensional stabbing max problem. While modern processors consist of sophisticated memory systems (multiple levels of caches, set associativity, TLB, prefetching), we empirically show that algorithms designed in simple models, that focus on minimizing the I/O transfers between shared memory and single level cache, can lead to efficient software on current multicore architectures. Our implementation exhibits significantly fewer accesses to slow DRAM and, therefore, outperforms traditional approaches based on plane sweep and two-way divide and conquer.Comment: Longer version of ESA'13 pape

    Determination of Freeze-out Conditions from Lattice QCD Calculations

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    Freeze-out conditions in Heavy Ion Collisions are generally determined by comparing experimental results for ratios of particle yields with theoretical predictions based on applications of the Hadron Resonance Gas model. We discuss here how this model dependent determination of freeze-out parameters may eventually be replaced by theoretical predictions based on equilibrium QCD thermodynamics.Comment: presented at the International Conference "Critical Point and Onset of Deconfinement - CPOD 2011", Wuhan, November 7-11, 201

    Effect of Finite Granularity of Detectors on Anisotropy Coefficients

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    The coefficients that describe the anisotropy in the azimuthal distribution of particles are lower when the particles are recorded in a detector with finite granularity and measures only hits. This arises due to loss of information because of multiple hits in any channel. The magnitude of this loss of signal depends both on the occupancy and on the value of the coefficient. These correction factors are obtained for analysis methods differing in detail, and are found to be different.Comment: 11 pages including 2 figure

    Event anisotropy in 4.2A GeV/c C+C collisions

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    The directed and elliptic flow of protons and negative pions in 4.2A GeV/c C+C collisions is studied using the Fourier analysis of azimuthal distributions. It is found that the protons exhibit pronounced directed flow, while the flow of pions is either non existent or too weak to be detected experimentally. Also, it is found that in the entire rapidity interval the elliptic flow is very small if not zero. These results are confirmed by the Quark-Gluon-String Model (QGSM) and the relativistic transport model (ART 1.0), except that these models predict very weak antiflow of pions. The more detailed comparison with the QGSM suggests that the decay of resonances and rescattering of secondaries dominantly determine the proton and negative pion flow at this energy.Comment: 7 pages, 3 figures, TeX file changed from double to single-spacin

    Use of Topographic Data on Land-Use Land-Cover Delineation by ERTS Imagery

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    The use of ERTS imagery for estimating land-use land-cover is of particular importance for the Canadian Department of the Environment for many reasons, one of which is the fact that this Department is using a lands-wide data bank of river basins characteristics for interpolation of hydrologic information in which land-use land-cover is an important one. Initially data on land-use land-cover were obtained by abstracting them by hand from 1/200,000 topographic maps, and were limited to the following elements: forested area, lake covered areas, swamp covered areas, and urbanized areas. The roughness of the information thus obtained, together with the fact that the data obtained could not be updated, resulted in significant difficulties in using the data in the interpolation of hydrologic information. This is particularly true when the technique of interpolation was a spatially distributed hydrologic model, recently developed and applied with success where detailed information on land-use and land-cover was available

    Simple Pendulum Revisited

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    We describe a 8085 microprocessor interface developed to make reliable time period measurements. The time period of each oscillation of a simple pendulum was measured using this interface. The variation of the time period with increasing oscillation was studied for the simple harmonic motion (SHM) and for large angle initial displacements (non-SHM). The results underlines the importance of the precautions which the students are asked to take while performing the pendulum experiment.Comment: 17 pages with 10 figure
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