323 research outputs found
Fuzzy spectral and spatial feature integration for classification of nonferrous materials in hyperspectral data
Hyperspectral data allows the construction of more elaborate models to sample the properties of the nonferrous materials than the standard RGB color representation. In this paper, the nonferrous waste materials are studied as they cannot be sorted by classical procedures due to their color, weight and shape similarities. The experimental results presented in this paper reveal that factors such as the various levels of oxidization of the waste materials and the slight differences in their chemical composition preclude the use of the spectral features in a simplistic manner for robust material classification. To address these problems, the proposed FUSSER (fuzzy spectral and spatial classifier) algorithm detailed in this paper merges the spectral and spatial features to obtain a combined feature vector that is able to better sample the properties of the nonferrous materials than the single pixel spectral features when applied to the construction of multivariate Gaussian distributions. This approach allows the implementation of statistical region merging techniques in order to increase the performance of the classification process. To achieve an efficient implementation, the dimensionality of the hyperspectral data is reduced by constructing bio-inspired spectral fuzzy sets that minimize the amount of redundant information contained in adjacent hyperspectral bands. The experimental results indicate that the proposed algorithm increased the overall classification rate from 44% using RGB data up to 98% when the spectral-spatial features are used for nonferrous material classification
Significance of Gravitational Nonlinearities on the Dynamics of Disk Galaxies
The discrepancy between the visible mass in galaxies or galaxy clusters, and
that inferred from their dynamics is well known. The prevailing solution to
this problem is dark matter. Here we show that a different approach, one that
conforms to both the current Standard Model of Particle Physics and General
Relativity, explains the recently observed tight correlation between the
galactic baryonic mass and its observed acceleration. Using direct calculations
based on General Relativity's Lagrangian, and parameter-free galactic models,
we show that the nonlinear effects of General Relativity make baryonic matter
alone sufficient to explain this observation.Comment: Accepted for publication in the Astrophysical Journa
The spectrum for Higgs production via heavy quark annihilation at NLL+aNLO
We study the transverse momentum () spectrum of the Higgs boson produced
via the annihilation of heavy quarks () in proton-proton collisions.
Using soft-collinear effective theory (SCET) and working in the five-flavour
scheme, we provide predictions at three-loop order in resummed perturbation
theory (NLL). We match the resummed calculation to full fixed-order
results at next-to-next-to-leading order (NNLO), and introduce a decorrelation
method to enable a consistent matching to an approximate NLO (aNLO)
result. Since the -quark initiated process exhibits large nonsingular
corrections, it requires special care in the matching procedure and estimation
of associated theoretical uncertainties, which we discuss in detail. Our
results constitute the most accurate predictions to date for these processes in
the small region and could be used to improve the determination of Higgs
Yukawa couplings from the shape of the measured Higgs spectrum.Comment: 25 pages + 11 appendix + references, 18 figure
Wideband Super-resolution Imaging in Radio Interferometry via Low Rankness and Joint Average Sparsity Models (HyperSARA)
We propose a new approach within the versatile framework of convex
optimization to solve the radio-interferometric wideband imaging problem. Our
approach, dubbed HyperSARA, solves a sequence of weighted nuclear norm and l21
minimization problems promoting low rankness and joint average sparsity of the
wideband model cube. On the one hand, enforcing low rankness enhances the
overall resolution of the reconstructed model cube by exploiting the
correlation between the different channels. On the other hand, promoting joint
average sparsity improves the overall sensitivity by rejecting artefacts
present on the different channels. An adaptive Preconditioned Primal-Dual
algorithm is adopted to solve the minimization problem. The algorithmic
structure is highly scalable to large data sets and allows for imaging in the
presence of unknown noise levels and calibration errors. We showcase the
superior performance of the proposed approach, reflected in high-resolution
images on simulations and real VLA observations with respect to single channel
imaging and the CLEAN-based wideband imaging algorithm in the WSCLEAN software.
Our MATLAB code is available online on GITHUB
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