7,880 research outputs found
Mass formulae and strange quark matter
We have derived the popularly used parametrization formulae for quark masses
at low densities and modified them at high densities within the
mass-density-dependent model. The results are applied to investigate the lowest
density for the possible existence of strange quark matter at zero temperature.Comment: 9 pages, LATeX with ELSART style, one table, no figures. Improvement
on the derivation of qark mass formula
(k,q)-Compressed Sensing for dMRI with Joint Spatial-Angular Sparsity Prior
Advanced diffusion magnetic resonance imaging (dMRI) techniques, like
diffusion spectrum imaging (DSI) and high angular resolution diffusion imaging
(HARDI), remain underutilized compared to diffusion tensor imaging because the
scan times needed to produce accurate estimations of fiber orientation are
significantly longer. To accelerate DSI and HARDI, recent methods from
compressed sensing (CS) exploit a sparse underlying representation of the data
in the spatial and angular domains to undersample in the respective k- and
q-spaces. State-of-the-art frameworks, however, impose sparsity in the spatial
and angular domains separately and involve the sum of the corresponding sparse
regularizers. In contrast, we propose a unified (k,q)-CS formulation which
imposes sparsity jointly in the spatial-angular domain to further increase
sparsity of dMRI signals and reduce the required subsampling rate. To
efficiently solve this large-scale global reconstruction problem, we introduce
a novel adaptation of the FISTA algorithm that exploits dictionary
separability. We show on phantom and real HARDI data that our approach achieves
significantly more accurate signal reconstructions than the state of the art
while sampling only 2-4% of the (k,q)-space, allowing for the potential of new
levels of dMRI acceleration.Comment: To be published in the 2017 Computational Diffusion MRI Workshop of
MICCA
r-Process Nucleosynthesis in Shocked Surface Layers of O-Ne-Mg Cores
We demonstrate that rapid expansion of the shocked surface layers of an
O-Ne-Mg core following its collapse can result in r-process nucleosynthesis. As
the supernova shock accelerates through these layers, it makes them expand so
rapidly that free nucleons remain in disequilibrium with alpha-particles
throughout most of the expansion. This allows heavy r-process isotopes
including the actinides to form in spite of the very low initial neutron excess
of the matter. We estimate that yields of heavy r-process nuclei from this site
may be sufficient to explain the Galactic inventory of these isotopes.Comment: 11 pages, 1 figure, to appear in the Astrophysical Journal Letter
Editorial: Security of cloud service for the manufacturing industry
With the rapid development of the industrial Internet, cloud service-based manufacturing has emerged as a next generation manufacturing paradigm that has potential to revolutionize the manufacturing industry. It is foreseeable that cloud services will be popular in the next generation manufacturing industry. In recent years, more and more manufacturing companies have recognized the benefits of cloud service and have developed cloud-based manufacturing models. However, the security problems need to be researched and solved for the cloud services in the manufacturing industry, especially the data security issues are important, and restrict the cloud application in the manufacturing industry. Regarding the security of data, some people believe that when data are stored in the cloud, manufacturing companies lose control of the data. The manufacturing companies focus on how to secure the data from the top-level management and how to minimize the security risks, such as those caused by data security or service migration challenges. The manufacturing companies select the reliable cloud service while consider function and budget feasibility. How to ensure security in cloud service for the manufacturing industry has become a topic of increasing interest for both academic researchers and developers from the industry. This special issue addresses this emerging and fast developing research area on cloud security in manufacturing industry. The summary of these papers is as follows. [...
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