342 research outputs found

    On the Four Types of Weight Functions for Spatial Contiguity Matrix

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    This is a "spatial autocorrelation analysis" of spatial autocorrelation. I use the 1-dimension spatial autocorrelation function (ACF) and partial autocorrelation function (PACF) to analyze four kinds of weight function in common use for the 2-dimensional spatial autocorrelation model. The aim of this study is at how to select a proper weight function to construct a spatial contiguity matrix for spatial analysis. The scopes of application of different weight functions are defined in terms of the characters of their ACFs and PACFs.Comment: 8 pages, 5 figures, 2 table

    Effects of integrated physical exercises and gestures on preschool children’s foreign language vocabulary learning

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    Research suggests that integrating human movement into a cognitive learning task can be effective for learning due to its cognitive and physiological effects. In this study, the learning effects of enacting words through whole-body movements (i.e., physical exercise) and part-body movements (i.e., gestures) were investigated in a foreign language vocabulary task. Participants were 111 preschool children of 15 childcare centers, who were randomly assigned to one of four conditions. Participants had to learn 14 Italian words in a 4-week teaching program. They were tested on their memory for the words during, directly after, and 6 weeks after the program. In the integrated physical exercise condition, children enacted the actions indicated by the words to be learned in physical exercises. In the non-integrated physical exercise condition children performed physical exercises at the same intensity, but unrelated to the learning task. In the gesturing condition, children enacted the actions indicated by the words to be learned by gesturing while remaining seated. In the conventional condition, children verbally repeated the words while remaining seated. Results confirmed the main hypothesis, indicating that children in the integrated physical exercise condition achieved the highest learning outcomes. Implications of integrated physical exercise programs for preschool children’s cognition and health are discussed

    Spatial weights : constructing weight-compatible exchange matrices from proximity matrices

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    Exchange matrices represent spatial weights as symmetric probability distributions on pairs of regions, whose margins yield regional weights, generally well-specified and known in most contexts. This contribution proposes a mechanism for constructing exchange matrices, derived from quite general symmetric proximity matrices, in such a way that the margin of the exchange matrix coincides with the regional weights. Exchange matrices generate in turn diffusive squared Euclidean dissimilarities, measuring spatial remoteness between pairs of regions. Unweighted and weighted spatial frameworks are reviewed and compared, regarding in particular their impact on permutation and normal tests of spatial autocorrelation. Applications include tests of spatial autocorrelation with diagonal weights, factorial visualization of the network of regions, multivariate generalizations of Moran's I, as well as "landscape clustering", aimed at creating regional aggregates both spatially contiguous and endowed with similar features

    Brane-Antibrane Inflation in Orbifold and Orientifold Models

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    We analyse the cosmological implications of brane-antibrane systems in string-theoretic orbifold and orientifold models. In a class of realistic models, consistency conditions require branes and antibranes to be stuck at different fixed points, and so their mutual attraction generates a potential for one of the radii of the underlying torus or the 4D string dilaton. Assuming that all other moduli have been fixed by string effects, we find that this potential leads naturally to a period of cosmic inflation with the radion or dilaton field as the inflaton. The slow-roll conditions are satisfied more generically than if the branes were free to move within the space. The appearance of tachyon fields at certain points in moduli space indicates the onset of phase transitions to different non-BPS brane systems, providing ways of ending inflation and reheating the corresponding observable brane universe. In each case we find relations between the inflationary parameters and the string scale to get the correct spectrum of density perturbations. In some examples the small numbers required as inputs are no smaller than 0.01, and are the same small quantities which are required to explain the gauge hierarchy.Comment: 30 pages, 2 figures. Substantial changes on version 1. New cosmological scenarios proposed including the dilaton as the inflaton. Main conclusions unchange

    Beauty in the Eye of the Home-Owner: Aesthetic Zoning and Residential Property Values

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    This article empirically confirms one core motivation for architectural zoning: Shape homogeneity among neighboring homes increases the value of residential buildings. Drawing on large-scale shape and transaction data, this study first develops a data-driven measure of architectural similarity, condensing three-dimensional shapes to univariate shape distributions. These algorithm-based similarity estimates are good predictors of human perceptions of shape similarity and are linked to property attributes and transaction prices. For the city of Rotterdam, a price premium of approximately 3.5% is estimated for row houses within very homogeneous ensembles over buildings facing heterogeneous neighbors

    A Geographer Looks at Spatial Information Theory

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    Abstract. Geographic information is defined as a subset of spatial information, specific to the spatiotemporal frame of the Earth’s surface. Thus geographic information theory inherits the results of spatial information theory, but adds results that reflect the specific properties of geographic information. I describe six general properties of geographic information, and show that in some cases specialization has assumed other properties that are less generally observed. A recognition of the distinction between geographic and spatial would allow geographic information theory to achieve greater depth and utility.

    Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

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    The Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb−1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2ÎČ\beta measurement from B0→J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0→J/ψKS0)=(1.83±0.28)×10−5BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date

    Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

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    Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201

    Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

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    A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

    Absolute luminosity measurements with the LHCb detector at the LHC

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    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex
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