12,141 research outputs found
“The Fall of the House of Usher”: Poe’s perverted perspective on the “Maimed King”
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
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
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
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
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 BaKFeAs, and a new method for identifying the electron contribution: two electron bands with different energy gaps in the superconducting state
We report measurements of the specific heat of
BaKFeAs, an Fe-pnictide superconductor with
= 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
-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 BaFeAs 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 -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
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
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
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 . 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 , 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
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,
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