31,770 research outputs found
A Quarkyonic Phase in Dense Two Color Matter?
We present results from simulations of Two Color QCD with two Wilson quark
flavors in the presence of a quark chemical potential mu at two different
lattice spacings. The equation of state, conformal anomaly, superfluid order
parameter and Polyakov line are all discussed. Our results suggest that the
transition from hadronic to quark matter, and that from confined to deconfined
matter occur at distinct values of mu, consistent with the existence of a
quarkyonic phase in this model.Comment: 5 pages, 4 figures, references added and discussion of conformal
anomaly extende
Limit Your Consumption! Finding Bounds in Average-energy Games
Energy games are infinite two-player games played in weighted arenas with
quantitative objectives that restrict the consumption of a resource modeled by
the weights, e.g., a battery that is charged and drained. Typically, upper
and/or lower bounds on the battery capacity are part of the problem
description. Here, we consider the problem of determining upper bounds on the
average accumulated energy or on the capacity while satisfying a given lower
bound, i.e., we do not determine whether a given bound is sufficient to meet
the specification, but if there exists a sufficient bound to meet it.
In the classical setting with positive and negative weights, we show that the
problem of determining the existence of a sufficient bound on the long-run
average accumulated energy can be solved in doubly-exponential time. Then, we
consider recharge games: here, all weights are negative, but there are recharge
edges that recharge the energy to some fixed capacity. We show that bounding
the long-run average energy in such games is complete for exponential time.
Then, we consider the existential version of the problem, which turns out to be
solvable in polynomial time: here, we ask whether there is a recharge capacity
that allows the system player to win the game.
We conclude by studying tradeoffs between the memory needed to implement
strategies and the bounds they realize. We give an example showing that memory
can be traded for bounds and vice versa. Also, we show that increasing the
capacity allows to lower the average accumulated energy.Comment: In Proceedings QAPL'16, arXiv:1610.0769
Quark Matter in QC(2)D
Results are presented from a numerical study of lattice QCD with gauge group
SU(2) and two flavors of Wilson fermion at non-zero quark chemical potential mu
>> T. Studies of the equation of state, the superfluid condensate, and the
Polyakov line all suggest that in addition to the low density phase of
Bose-condensed diquark baryons, there is a deconfined phase at higher quark
density in which quarks form a degenerate system, whose Fermi surface is only
mildly disrupted by Cooper pair condensation.Comment: 3 pages, 4 figures, contributed talk at "Quarks and Nuclear Physics",
Madrid, 5th-10th June 200
Free-stream turbulence and concave curvature effects on heated, transitional boundary layers, volume 1
An experimental investigation of the transition process on flat-plate and concave curved-wall boundary layers for various free-streem turbulence levels was performed. Where possible, sampling according to the intermittency function was made. Such sampling allowed segregation of the signal into two types of behavior: laminar-like and turbulent-like. The results from the investigation are discussed. Documentation is presented in two volumes. Volume one contains the text of the report including figures and supporting appendices. Volume two contains data reduction program listings and tabulated data
Unsupervised patient representations from clinical notes with interpretable classification decisions
We have two main contributions in this work: 1. We explore the usage of a
stacked denoising autoencoder, and a paragraph vector model to learn
task-independent dense patient representations directly from clinical notes. We
evaluate these representations by using them as features in multiple supervised
setups, and compare their performance with those of sparse representations. 2.
To understand and interpret the representations, we explore the best encoded
features within the patient representations obtained from the autoencoder
model. Further, we calculate the significance of the input features of the
trained classifiers when we use these pretrained representations as input.Comment: Accepted poster at NIPS 2017 Workshop on Machine Learning for Health
(https://ml4health.github.io/2017/
Limited Angle Acousto-Electrical Tomography
This paper considers the reconstruction problem in Acousto-Electrical
Tomography, i.e., the problem of estimating a spatially varying conductivity in
a bounded domain from measurements of the internal power densities resulting
from different prescribed boundary conditions. Particular emphasis is placed on
the limited angle scenario, in which the boundary conditions are supported only
on a part of the boundary. The reconstruction problem is formulated as an
optimization problem in a Hilbert space setting and solved using Landweber
iteration. The resulting algorithm is implemented numerically in two spatial
dimensions and tested on simulated data. The results quantify the intuition
that features close to the measurement boundary are stably reconstructed and
features further away are less well reconstructed. Finally, the ill-posedness
of the limited angle problem is quantified numerically using the singular value
decomposition of the corresponding linearized problem.Comment: 23 page
- …