162 research outputs found
Non-perturbative Renormalization of Bilinear Operators with Improved Staggered Quarks
We present renormalization factors for the bilinear operators obtained using
the non-perturbative renormalization method (NPR) in the RI-MOM scheme with
improved staggered fermions on the MILC asqtad lattices (). We use
the MILC coarse ensembles with geometry and . We obtain the wave function renormalization factor from the
conserved vector current and the mass renormalization factor from the
scalar bilinear operator. We also present preliminary results of
renormalization factors for other bilinear operators.Comment: 7 pages, 4 figures, Lattice 2013 Proceedin
Non-Perturbative Renormalization for Staggered Fermions (Self-energy Analysis)
We present preliminary results of data analysis for the non-perturbative
renormalization (NPR) on the self-energy of the quark propagators calculated
using HYP improved staggered fermions on the MILC asqtad lattices. We use the
momentum source to generate the quark propagators. In principle, using the
vector projection operator of and the
scalar projection operator , we should be able to
obtain the wave function renormalization factor and the mass
renormalization factor . Using the MILC coarse lattice, we
obtain a preliminary but reasonable estimate of and from
the data analysis on the self-energy.Comment: 7 pages, 4 figures, Contribution to proceedings of 30th International
Symposium on Lattice Field Theory (Lattice 2012), June 24-29, 2012; Cairns,
Australi
Dual Formulation and Phase Diagram of Lattice QCD in the Strong Coupling Regime
We present the computation of invariants that arise in the strong coupling
expansion of lattice QCD. These invariants are needed for Monte Carlo
simulations of Lattice QCD with staggered fermions in a dual, color singlet
representation. This formulation is in particular useful to tame the finite
density sign problem. The gauge integrals in this limiting case
are well known, but the gauge integrals needed to study
the gauge corrections are more involved. We discuss a method to evaluate such
integrals.
The phase boundary of lattice QCD for staggered fermions in the
plane has been established in the strong coupling limit. We present numerical
simulations away from the strong coupling limit, taking into account the higher
order gauge corrections via plaquette occupation numbers. This allows to study
the nuclear and chiral transition as a function of .Comment: 16 pages, 10 figures, Proceedings of the 35th International Symposium
on Lattice Field Theory, Granada, Spai
FickleNet: Weakly and Semi-supervised Semantic Image Segmentation using Stochastic Inference
The main obstacle to weakly supervised semantic image segmentation is the
difficulty of obtaining pixel-level information from coarse image-level
annotations. Most methods based on image-level annotations use localization
maps obtained from the classifier, but these only focus on the small
discriminative parts of objects and do not capture precise boundaries.
FickleNet explores diverse combinations of locations on feature maps created by
generic deep neural networks. It selects hidden units randomly and then uses
them to obtain activation scores for image classification. FickleNet implicitly
learns the coherence of each location in the feature maps, resulting in a
localization map which identifies both discriminative and other parts of
objects. The ensemble effects are obtained from a single network by selecting
random hidden unit pairs, which means that a variety of localization maps are
generated from a single image. Our approach does not require any additional
training steps and only adds a simple layer to a standard convolutional neural
network; nevertheless it outperforms recent comparable techniques on the Pascal
VOC 2012 benchmark in both weakly and semi-supervised settings.Comment: To appear in CVPR 201
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