12,141 research outputs found

    “The Fall of the House of Usher”: Poe’s perverted perspective on the “Maimed King”

    Get PDF
    The themes of medieval literature had a profound effect on the works that would follow in later generations regardless of the writer’s recognition of this influence, and one can see the way Poe leaves traces of the popular medieval motif of the “Maimed King” in his short story, “The Fall of the House of Usher”. This thematic device, which predates the medieval period, gained prominence in the tales of King Arthur and the Grail Quest. Although there is no clear indication that Poe intentionally set out to create a gothic rendition of this traditional theme, that does not discount the possibility of “Usher” having been conditioned in some respect by this medieval notion. Through implementing a close reading of the story and comparing it to a framework of this conception of the “Maimed King”, this paper points out a number of striking similarities between the two, as well as demonstrates the far-reaching influence of medievalism in one of nineteenth-century America’s preeminent fiction writers, Edgar Allan Poe

    Phase Transitions and Duality in Adiabatic Memristive Networks

    Full text link
    The development of neuromorphic systems based on memristive elements - resistors with memory - requires a fundamental understanding of their collective dynamics when organized in networks. Here, we study an experimentally inspired model of two-dimensional disordered memristive networks subject to a slowly ramped voltage and show that they undergo a first-order phase transition in the conductivity for sufficiently high values of memory, as quantified by the memristive ON/OFF ratio. We investigate the consequences of this transition for the memristive current-voltage characteristics both through simulation and theory, and uncover a duality between forward and reverse switching processes that has also been observed in several experimental systems of this sort. Our work sheds considerable light on the statistical properties of memristive networks that are presently studied both for unconventional computing and as models of neural networks.Comment: 12 pages, 9 figure

    Ringing the initial Universe: the response of overdensity and transformed-density power spectra to initial spikes

    Full text link
    We present an experiment in which we 'ring' a set of cosmological N-body-simulation initial conditions, placing spikes in the initial power spectrum at different wavenumber bins. We then measure where these spikes end up in the final conditions. In the usual overdensity power spectrum, most sensitive to contracting and collapsing dense regions, initial power on slightly non-linear scales (k ~ 0.3 h/Mpc) smears to smaller scales, coming to dominate the initial power once there. Log-density and Gaussianized-density power spectra, sensitive to low-density (expanding) and high-density regions, respond differently: initial spikes spread symmetrically in scale, both upward and downward. In fact, in the power spectrum of 1/(1 + {\delta}), spikes migrate to larger scales, showing the magnifying effect of voids on small-scale modes. These power spectra show much greater sensitivity to small-scale initial features. We also test the difference between an approximation of the Ly-{\alpha} flux field, and its Gaussianized form, and give a toy model that qualitatively explains the symmetric power spreading in Gaussianized-density power spectra. Also, we discuss how to use this framework to estimate power-spectrum covariance matrices. This can be used to track the fate of information in the Universe, that takes the form of initial degrees of freedom, one random spike per initial mode.Comment: Accepted to MNRAS Letters. 6 pages, 5 figure

    THE INDUSTRY HAS CHANGED, HAVE YOU? THE AGCO STORY

    Get PDF
    AGCO Corporation is a success story in the agricultural machinery sector. Utilizing marketing strategies of out-sourcing, cross-over selling, and a full line of products, AGCO markets its own way. In 7 years, AGCO has 18 brands sold through 7,000 dealerships in 140 countries. Acquisition and consolidation powered the growth of AGCO using nontraditional buyout financing. Herein lies its real success.Agribusiness, Industrial Organization,

    The 8-13 micron observations of Titan

    Get PDF
    Narrow band observations of Titan at selected wavelengths in the 8-13 micron range show evidence for a strong temperature inversion and the existence of at least one more spectroscopically active component in the atmosphere in addition to H2 and CH4

    Specific heat of Ba0.59_{0.59}K0.41_{0.41}Fe2_{2}As2_{2}, and a new method for identifying the electron contribution: two electron bands with different energy gaps in the superconducting state

    Full text link
    We report measurements of the specific heat of Ba0.59_{0.59}K0.41_{0.41}Fe2_{2}As2_{2}, an Fe-pnictide superconductor with TcT_c = 36.9 K, for which there are suggestions of an unusual electron pairing mechanism. We use a new method of analysis of the data to derive the parameters characteristic of the electron contribution. It is based on comparisons of α{\alpha}-model expressions for the electron contribution with the total measured specific heat, which give the electron contribution directly. It obviates the need in the conventional analyses for an independent, necessarily approximate, determination of the lattice contribution, which is subtracted from the total specific heat to obtain the electron contribution. It eliminates the uncertainties and errors in the electron contribution that follow from the approximations in the determination of the lattice contribution. Our values of the parameters characteristic of the electron contribution differ significantly from those obtained in conventional analyses of specific-heat data for five similar hole-doped BaFe2_{2}As2_{2} superconductors, which also differ significantly among themselves. They show that the electron density of states is comprised of contributions from two electron bands with superconducting-state energy gaps that differ by a factor 3.8, with 77%\% coming from the band with the larger gap. The variation of the specific heat with magnetic field is consistent with extended ss-wave pairing, one of the theoretical predictions. The relation between the densities of states and the energy gaps in the two bands is not consistent with a theoretical model based on interband interactions alone. Comparison of the normal-state density of states with band-structure calculations shows an extraordinarily large effective mass enhancement, for which there is no precedent in similar materials and no theoretical explanation.Comment: 30 pages, 7 figures, submitte

    SMS text pre-notification and delivery of reminder e-mails to increase response rates to postal questionnaires in the SUSPEND trial : a factorial design, randomised controlled trial

    Get PDF
    Acknowledgements SUSPEND was funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project 80/71/01) and will be published in full in Health Technology Assessment. The Health Services Research Unit of the University of Aberdeen is funded in part by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Chief Scientist Office, HTA programme, NIHR, National Health Service, or Department of Health. The authors thank the SUSPEND staff and participants, without whom this study would not have been possible.Peer reviewedPublisher PD

    Space shuttle electromagnetic environment experiment. Phase A: Definition study

    Get PDF
    Methods for carrying out measurements of earth electromagnetic environment using the space shuttle as a measurement system platform are herein reported. The goal is to provide means for mapping intentional and nonintentional emitters on earth in the frequency range 0.4 to 40 GHz. A survey was made of known emitters using available data from national and international regulatory agencies, and from industry sources. The spatial distribution of sources, power levels, frequencies, degree of frequency re-use, etc., found in the survey, are here presented. A concept is developed for scanning the earth using a directive antenna whose beam is made to rotate at a fixed angle relative to the nadir; the illuminated area swept by the beam is of the form of cycloidal annulus over a sphere. During the beam's sojourn over a point, the receiver sweeps in frequency over ranges in the order of octave width using sweeping filter bandwidths sufficient to give stable readings

    Critical branching processes in digital memcomputing machines

    Full text link
    Memcomputing is a novel computing paradigm that employs time non-locality (memory) to solve combinatorial optimization problems. It can be realized in practice by means of non-linear dynamical systems whose point attractors represent the solutions of the original problem. It has been previously shown that during the solution search digital memcomputing machines go through a transient phase of avalanches (instantons) that promote dynamical long-range order. By employing mean-field arguments we predict that the distribution of the avalanche sizes follows a Borel distribution typical of critical branching processes with exponent τ=3/2\tau= 3/2. We corroborate this analysis by solving various random 3-SAT instances of the Boolean satisfiability problem. The numerical results indicate a power-law distribution with exponent τ=1.51±0.02\tau = 1.51 \pm 0.02, in very good agreement with the mean-field analysis. This indicates that memcomputing machines self-tune to a critical state in which avalanches are characterized by a branching process, and that this state persists across the majority of their evolution.Comment: 5 pages, 3 figure

    PERFORMANCE OF ALTERNATIVE COMPONENT PRICING SYSTEMS FOR PORK

    Get PDF
    One method of implementing value-based marketing is a component pricing system. This research develops and evaluates alternative component pricing systems for pork. Two electronic technologies for estimating carcass components (optical probe and electromagnetic scanner) were evaluated on two sets of data representing different populations. Model accuracy increased as additional components were added.Carcass merit, Component pricing, Electromagnetic scanning, Pork, Marketing,
    corecore