25,293 research outputs found
Fractal Location and Anomalous Diffusion Dynamics for Oil Wells from the KY Geological Survey
Utilizing data available from the Kentucky Geonet (KYGeonet.ky.gov) the
fossil fuel mining locations created by the Kentucky Geological Survey
geo-locating oil and gas wells are mapped using ESRI ArcGIS in Kentucky single
plain 1602 ft projection. This data was then exported into a spreadsheet
showing latitude and longitude for each point to be used for modeling at
different scales to determine the fractal dimension of the set. Following the
porosity and diffusivity studies of Tarafdar and Roy1 we extract fractal
dimensions of the fossil fuel mining locations and search for evidence of
scaling laws for the set of deposits. The Levy index is used to determine a
match to a statistical mechanically motivated generalized probability function
for the wells. This probability distribution corresponds to a solution of a
dynamical anomalous diffusion equation of fractional order that describes the
Levy paths which can be solved in the diffusion limit by the Fox H function
ansatz.Comment: : 8 pages, 3 figures, AIPG Conference Meeting, Grand Junction CO,
Oct. 200
The Coronal Analysis of SHocks and Waves (CASHeW) Framework
Coronal Bright Fronts (CBF) are large-scale wavelike disturbances in the
solar corona, related to solar eruptions. They are observed in extreme
ultraviolet (EUV) light as transient bright fronts of finite width, propagating
away from the eruption source. Recent studies of individual solar eruptive
events have used EUV observations of CBFs and metric radio type II burst
observations to show the intimate connection between low coronal waves and
coronal mass ejection (CME)-driven shocks. EUV imaging with the Atmospheric
Imaging Assembly(AIA) instrument on the Solar Dynamics Observatory (SDO) has
proven particularly useful for detecting CBFs, which, combined with radio and
in situ observations, holds great promise for early CME-driven shock
characterization capability. This characterization can further be automated,
and related to models of particle acceleration to produce estimates of particle
fluxes in the corona and in the near Earth environment early in events. We
present a framework for the Coronal Analysis of SHocks and Waves (CASHeW). It
combines analysis of NASA Heliophysics System Observatory data products and
relevant data-driven models, into an automated system for the characterization
of off-limb coronal waves and shocks and the evaluation of their capability to
accelerate solar energetic particles (SEPs). The system utilizes EUV
observations and models written in the Interactive Data Language (IDL). In
addition, it leverages analysis tools from the SolarSoft package of libraries,
as well as third party libraries. We have tested the CASHeW framework on a
representative list of coronal bright front events. Here we present its
features, as well as initial results. With this framework, we hope to
contribute to the overall understanding of coronal shock waves, their
importance for energetic particle acceleration, as well as to the better
ability to forecast SEP events fluxes.Comment: Accepted for publication in the Journal of Space Weather and Space
Climate (SWSC
Subleading Shape-Function Effects and the Extraction of |V_ub|
We derive a class of formulae relating moments of B -> Xu l nu to B -> Xs
gamma in the shape function region, where m_X^2 ~ m_b Lambda_QCD. We also
derive an analogous class of formulae involving the decay B -> Xs l+ l-. These
results incorporate Lambda_QCD/m_b power corrections, but are independent of
leading and subleading hadronic shape functions. Consequently, they enable one
to determine |V_ub|/|V_tb V_ts*| to subleading order in a model-independent
way.Comment: 23 page
Some Revised Observational Constraints on the Formation and Evolution of the Galactic Disk
A set of 76 open clusters with abundances based upon DDO photometry and/or
moderate dispersion spectroscopy has been transformed to a common [Fe/H] scale
and used to study the local structure and evolution of the galactic disk. The
metallicity distribution of clusters with R_GC is best described by two
distinct zones. Between R_GC = 6.5 and 10 kpc, the distribution has a mean
[Fe/H] = 0.0 and a dispersion of 0.1 dex; there is only weak evidence for a
shallow abundance gradient over this distance range. Beyond R_GC = 10 kpc, the
metallicity distribution has a dispersion between 0.10 and 0.15 dex, but with a
mean [Fe/H] = -0.3, implying a sharp discontinuity at R_GC = 10 kpc. After
correcting for the discontinuity, no evidence is found for a gradient
perpendicular to the plane. Adopting the clusters interior to 10 kpc as a
representative sample of the galactic disk over the last 7 Gyr, the cluster
metallicity range is found to be about half that of the field stars. When
coupled with the discontinuity in the galactocentric gradient, the discrepancy
in the metallicity distribution is interpreted as an indication of significant
diffusion of field stars into the solar neighborhood from beyond 10 kpc. These
results imply that the sun is NOT atypical of the stars formed in the solar
circle 4.6 Gyr ago. It is suggested that the discontinuity reflects the edge of
the initial galactic disk as defined by the disk globular cluster system and
the so-called thick disk; the initial offset in [Fe/H] created by the
differences in the chemical history on either side of the discontinuity has
carried through to the current stage of galactic evolution. If correct,
diffusion coupled with the absence of an abundance gradient could make the
separation of field stars on the basis of galactocentric origin difficult.Comment: 41 pages, 9 figure files, LaTex. Appendix section and tables (tex or
postscript) available at http://kubarb.phsx.ukans.edu/ ~twarog/ Submitted to
Astronomical Journal July 199
Three-point density correlation functions in the fractional quantum Hall regime
In this paper we consider the three-particle density correlation function for
a fractional quantum Hall liquid. The study of this object is motivated by
recent experimental studies of fractional quantum Hall systems using inelastic
light scattering and phonon absorption techniques. Symmetry properties of the
correlation function are noted. An exact sum-rule is derived which this
quantity must obey. This sum-rule is used to assess the convolution
approximation that has been used to estimate the matrix elements for such
experiments. PACS Numbers: 73.40.Hm, 73.20.Mf, 72.10.DiComment: 12 pages + 1 (PS) figur
Environmental Dependence of Masses and Coupling Constants
We construct a class of scalar field models coupled to matter that lead to
the dependence of masses and coupling constants on the ambient matter density.
Such models predict a deviation of couplings measured on the Earth from values
determined in low-density astrophysical environments, but do not necessarily
require the evolution of coupling constants with the redshift in the recent
cosmological past. Additional laboratory and astrophysical tests of \Delta
\alpha and \Delta(m_p/m_e) as functions of the ambient matter density are
warranted.Comment: 20 pages, no figures, references added, minor editorial change
Accelerating Training of Deep Neural Networks via Sparse Edge Processing
We propose a reconfigurable hardware architecture for deep neural networks
(DNNs) capable of online training and inference, which uses algorithmically
pre-determined, structured sparsity to significantly lower memory and
computational requirements. This novel architecture introduces the notion of
edge-processing to provide flexibility and combines junction pipelining and
operational parallelization to speed up training. The overall effect is to
reduce network complexity by factors up to 30x and training time by up to 35x
relative to GPUs, while maintaining high fidelity of inference results. This
has the potential to enable extensive parameter searches and development of the
largely unexplored theoretical foundation of DNNs. The architecture
automatically adapts itself to different network sizes given available hardware
resources. As proof of concept, we show results obtained for different bit
widths.Comment: Presented at the 26th International Conference on Artificial Neural
Networks (ICANN) 2017 in Alghero, Ital
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