2,165 research outputs found

    The role of answer fluency and perceptual fluency in the monitoring and control of reasoning: Reply to Alter, Oppenheimer, and Epley

    Get PDF
    In this reply, we provide an analysis of Alter et al. (2013) response to our earlier paper (Thompson et al., 2013). In that paper, we reported difficulty in replicating Alter, Oppenheimer, Epley, and Eyre’s (2007) main finding, namely that a sense of disfluency produced by making stimuli difficult to perceive, increased accuracy on a variety of reasoning tasks. Alter, Oppenheimer, and Epley (2013) argue that we misunderstood the meaning of accuracy on these tasks, a claim that we reject. We argue and provide evidence that the tasks were not too difficult for our populations (such that no amount of “metacognitive unease” would promote correct responding) and point out that in many cases performance on our tasks was well above chance or on a par with Alter et al.’s (2007) participants. Finally, we reiterate our claim that the distinction between answer fluency (the ease with which an answer comes to mind) and perceptual fluency (the ease with which a problem can be read) is genuine, and argue that Thompson et al. (2013) provided evidence that these are distinct factors that have different downstream effects on cognitive processe

    Use of credit by farm families in southern Iowa and northern Missouri

    Get PDF
    Changing economic and social conditions necessitate adjustment by farm families. For many families, increased farm size and rising levels of consumption have resulted in larger outlays for the farm business as well as for family living. Increasingly, farm families have turned to credit to augment their own funds. Therefore, more information is needed about the extent to which credit is used, the uses to which credit is put and the association, if any, between credit use and selected family and economic characteristics. Such information should be useful to extension educators working with farm families in educational programs, to governmental policymakers or legislators who influence the legal framework affecting lending practices and to lending institutions interested in providing greater service to their clientele.https://lib.dr.iastate.edu/specialreports/1032/thumbnail.jp

    Almost-Euclidean subspaces of 1N\ell_1^N via tensor products: a simple approach to randomness reduction

    Get PDF
    It has been known since 1970's that the N-dimensional 1\ell_1-space contains nearly Euclidean subspaces whose dimension is Ω(N)\Omega(N). However, proofs of existence of such subspaces were probabilistic, hence non-constructive, which made the results not-quite-suitable for subsequently discovered applications to high-dimensional nearest neighbor search, error-correcting codes over the reals, compressive sensing and other computational problems. In this paper we present a "low-tech" scheme which, for any a>0a > 0, allows to exhibit nearly Euclidean Ω(N)\Omega(N)-dimensional subspaces of 1N\ell_1^N while using only NaN^a random bits. Our results extend and complement (particularly) recent work by Guruswami-Lee-Wigderson. Characteristic features of our approach include (1) simplicity (we use only tensor products) and (2) yielding "almost Euclidean" subspaces with arbitrarily small distortions.Comment: 11 pages; title change, abstract and references added, other minor change

    Spin Structure of the Proton and Large p_T Processes in Polarized pp Collisions

    Get PDF
    QCD motivated polarized parton distributions, evolved directly in x-space, are used to predict rates for prompt photon and Jet production at RHIC and HERA-N center of mass energies. Various scenarios for the polarized gluon distributions are considered and compared, and the possibility of using large p_T processes in polarized pp collision experients to choose between them is analyzed.Comment: 34 pages, including 18 postscript figures, REVTe

    The central limit problem for random vectors with symmetries

    Full text link
    Motivated by the central limit problem for convex bodies, we study normal approximation of linear functionals of high-dimensional random vectors with various types of symmetries. In particular, we obtain results for distributions which are coordinatewise symmetric, uniform in a regular simplex, or spherically symmetric. Our proofs are based on Stein's method of exchangeable pairs; as far as we know, this approach has not previously been used in convex geometry and we give a brief introduction to the classical method. The spherically symmetric case is treated by a variation of Stein's method which is adapted for continuous symmetries.Comment: AMS-LaTeX, uses xy-pic, 23 pages; v3: added new corollary to Theorem

    Charmless two-body B decays: A global analysis with QCD factorization

    Full text link
    In this paper, we perform a global analysis of BPPB \to PP and PVPV decays with the QCD factorization approach. It is encouraging to observe that the predictions of QCD factorization are in good agreement with experiment. The best fit γ\gamma is around 7979^\circ. The penguin-to-tree ratio Pππ/Tππ|P_{\pi \pi}/T_{\pi \pi}| of π+π\pi^+ \pi^- decays is preferred to be larger than 0.3. We also show the confidence levels for some interesting channels: B0π0π0B^0 \to \pi^0 \pi^0, K+KK^+ K^- and B+ωπ+B^+ \to \omega \pi^+, ωK+\omega K^+. For BπKB \to \pi K^\ast decays, they are expected to have smaller branching ratios with more precise measurements.Comment: 20 pages, 4 figures, version to appear in Phys. Rev.

    X-ray and Radio Variability of M31*, The Andromeda Galaxy Nuclear Supermassive Black Hole

    Get PDF
    We confirm our earlier tentative detection of M31* in X-rays and measure its light-curve and spectrum. Observations in 2004-2005 find M31* rather quiescent in the X-ray and radio. However, X-ray observations in 2006-2007 and radio observations in 2002 show M31* to be highly variable at times. A separate variable X-ray source is found near P1, the brighter of the two optical nuclei. The apparent angular Bondi radius of M31* is the largest of any black hole, and large enough to be well resolved with Chandra. The diffuse emission within this Bondi radius is found to have an X-ray temperature ~0.3 keV and density 0.1 cm-3, indistinguishable from the hot gas in the surrounding regions of the bulge given the statistics allowed by the current observations. The X-ray source at the location of M31* is consistent with a point source and a power law spectrum with energy slope 0.9+/-0.2. Our identification of this X-ray source with M31* is based solely on positional coincidence.Comment: 25 pages, 8 figures, submitted to Ap
    corecore