4,032 research outputs found
Laplacian-Steered Neural Style Transfer
Neural Style Transfer based on Convolutional Neural Networks (CNN) aims to
synthesize a new image that retains the high-level structure of a content
image, rendered in the low-level texture of a style image. This is achieved by
constraining the new image to have high-level CNN features similar to the
content image, and lower-level CNN features similar to the style image. However
in the traditional optimization objective, low-level features of the content
image are absent, and the low-level features of the style image dominate the
low-level detail structures of the new image. Hence in the synthesized image,
many details of the content image are lost, and a lot of inconsistent and
unpleasing artifacts appear. As a remedy, we propose to steer image synthesis
with a novel loss function: the Laplacian loss. The Laplacian matrix
("Laplacian" in short), produced by a Laplacian operator, is widely used in
computer vision to detect edges and contours. The Laplacian loss measures the
difference of the Laplacians, and correspondingly the difference of the detail
structures, between the content image and a new image. It is flexible and
compatible with the traditional style transfer constraints. By incorporating
the Laplacian loss, we obtain a new optimization objective for neural style
transfer named Lapstyle. Minimizing this objective will produce a stylized
image that better preserves the detail structures of the content image and
eliminates the artifacts. Experiments show that Lapstyle produces more
appealing stylized images with less artifacts, without compromising their
"stylishness".Comment: Accepted by the ACM Multimedia Conference (MM) 2017. 9 pages, 65
figure
Environmental and social determinants of leisure-time physical activity in children with autism spectrum disorder
Background: It is increasingly recognized that children\u27s physical activity behaviors are shaped by neighborhood environment factors and their parent\u27s support. However, these factors have been scarcely studied among children with autism spectrum disorder (ASD), a population at risk of inactivity. Objective: This cross-sectional survey study was designed to examine how neighborhood environmental factors and parental support are related to physical activity levels of children with ASD. Also, this study examined if the relationship between the environment and physical activity is modified by demographic factors and COVID-19 related concerns. Methods: An online survey was completed by parents of children with ASD aged 10–17 years. The questionnaire included items related to environmental factors (i.e., distance to school, distance to park, existence of sidewalks, walkability), parent support for physical activity (i.e., encouraging, watching, and providing transportation), child\u27s physical activity, and demographic characteristics. The instrument also queried parental concerns about COVID-19 and their child\u27s physical activity participation. Results: The results indicate that proximity to a local park and to school is positively associated with physical activity. Parent\u27s encouraging behavior correlated with and predicted children\u27s physical activity levels. Also, higher levels of COVID-19 related concerns among parents were related to decreased physical activity supporting behaviors. Conclusions: This study demonstrated that the neighborhood environment, in particular the distance between home and parks and schools, and parent support behavior are influential factors that may shape physical activity behaviors for children with ASD
A Massive Yang-Mills Theory based on the Nonlinearly Realized Gauge Group
We propose a subtraction scheme for a massive Yang-Mills theory realized via
a nonlinear representation of the gauge group (here SU(2)). It is based on the
subtraction of the poles in D-4 of the amplitudes, in dimensional
regularization, after a suitable normalization has been performed. Perturbation
theory is in the number of loops and the procedure is stable under iterative
subtraction of the poles. The unphysical Goldstone bosons, the Faddeev-Popov
ghosts and the unphysical mode of the gauge field are expected to cancel out in
the unitarity equation. The spontaneous symmetry breaking parameter is not a
physical variable. We use the tools already tested in the nonlinear sigma
model: hierarchy in the number of Goldstone boson legs and weak power-counting
property (finite number of independent divergent amplitudes at each order). It
is intriguing that the model is naturally based on the symmetry SU(2)_L local
times SU(2)_R global. By construction the physical amplitudes depend on the
mass and on the self-coupling constant of the gauge particle and moreover on
the scale parameter of the radiative corrections. The Feynman rules are in the
Landau gauge.Comment: 44 pages, 1 figure, minor changes, final version accepted by Phys.
Rev.
A Profile of Nonresident Travelers through Missoula: Winter 1993
Describes travel characteristics of nonresident visitors to Montana who passed through, made expenditures, or stayed overnight in Missoula during the 1993 winter season. Characteristics are compared to statewide winter travel characteristics
Effect of age on the prognostic value of left ventricular function in patients with acute coronary syndrome:a prospective registry study
Objective: This study aims to study the prognostic impact of LV function on mortality and examine the effect of age on the prognostic value of left ventricular function. Methods: We examined the Myocardial Ischaemia National Audit Project (MINAP) registry (2006-2010) data with a mean follow up of 2.1 years. LV function was categorized into good (ejection fraction (EF) ≥50%), moderate (EF 30-49%) and poor (EF <30%) categories. Cox-proportional hazards models were constructed to examine the prognostic significance of LV function in different age groups (<65, 65-74, 75-84 and ≥85 years) on all-cause mortality adjusting for baseline variables. Results: Of 424,848 patients, LV function data available for 123,609. Multiple imputations were used to impute missing values of LV function and the final sample for analyses were drawn from 414,305. After controlling for confounders, 339,887 participants were included in the regression models. For any age group, mortality was higher with worsening degree of LV impairment. Increased age reduced the adverse prognosis associated with reduced LV function (hazard ratios (HRs) of death comparing poor LV function to good LV function were 2.11 95%CI 1.88-2.37 for age <65 years and 1.28 95%CI 1.20-1.36 for age ≥85 years. Older patients had a high mortality risk even in those with good LV function. HRs of mortality for ≥85 compared to <65 years (HR=1.00) within good, moderate and poor ejection fractions groups were 5.89, 4.86 and 3.43, respectively. Conclusions: In patients with ACS, clinicians should interpret the prognostic value of LV function taking into account patient’s age
Non-saturating large magnetoresistance in semimetals
The rapidly expanding class of quantum materials known as {\emph{topological
semimetals}} (TSM) display unique transport properties, including a striking
dependence of resistivity on applied magnetic field, that are of great interest
for both scientific and technological reasons. However, experimental signatures
that can identify or discern the dominant mechanism and connect to available
theories are scarce. Here we present the magnetic susceptibility (), the
tangent of the Hall angle () along with magnetoresistance in four
different non-magnetic semimetals with high mobilities, NbP, TaP, NbSb and
TaSb, all of which exhibit non-saturating large MR. We find that the
distinctly different temperature dependences, and the values of
in phosphides and antimonates serve as empirical criteria to
sort the MR from different origins: NbP and TaP being uncompensated semimetals
with linear dispersion, in which the non-saturating magnetoresistance arises
due to guiding center motion, while NbSb and TaSb being {\it
compensated} semimetals, with a magnetoresistance emerging from nearly perfect
charge compensation of two quadratic bands. Our results illustrate how a
combination of magnetotransport and susceptibility measurements may be used to
categorize the increasingly ubiquitous non-saturating large magnetoresistance
in TSMs.Comment: Accepted for publication at Proc. Natl. Acad. Sci., minor revisions,
6 figure
Theory of a Continuous H Normal-to-Superconducting Transition
I study the transition within the Ginzburg-Landau model, with
-component order parameter . I find a renormalized fixed point free
energy, exact in limit, suggestive of a nd-order
transition in contrast to a general belief of a st-order transition. The
thermal fluctuations for force one to consider an infinite set of
marginally relevant operators for . I find , predicting
that the ODLRO does not survive thermal fluctuations in . The result is
a solution to a critical fixed point that was found to be inaccessible within
-expansion, previously considered in E.Brezin, D.R.Nelson,
A.Thiaville, Phys.Rev.B {\bf 31}, 7124 (1985), and was interpreted as a
st-order transition.Comment: 4 pages, self-unpacking uuencoded compressed postscript file with a
figure already inside text; to appear in Phys. Rev. Lett
Bathymetric Mapping and Sonar Imaging of Tufa at Green Lakes: Fayetteville, New York
The Fayetteville Green Lakes State Park, located in Fayetteville, New York, consists of two deep (48 m+), meromictic (non-mixing) lakes with unique limnological, bacterial, and chemical characteristics. These lakes, named Round Lake and its larger companion Green Lake, have been extensively studied for nearly 200 years because of their unique character. The lake water contains two distinct layers, the oxygen-rich mixolimnion and the anoxic monimolimnion divided by the chemocline (a chemical compositional boundary). Tufa deposits exist along the shorelines of both lakes at various depths and are a product of groundwater output into the lakes, as well as the lakes’ unique water chemistry and microbial communities. Here, we use sonar imaging techniques to produce updated bathymetric maps of Green and Round Lake, and provide the first detailed characterization of the near-shore environment using side-scanning sonar imagery to determine the locations and morphologies of tufa deposits. We also document shoreline debris specifically large tree trunks and branches which have fallen into the lake over time and are frequently encrusted. We identified fourteen locations of tufa ranging from large formations (10s of meters long) to small tufa heads (~1 m) in Green Lake. Our updated bathymetry and documentation of tufa locations and geometry expand on an extensive history of prior work, will aid future investigators by revealing lesser-known tufa localities, and will assist the Fayetteville Green Lakes State Park with monitoring and conservation efforts for this ecologically unique area
Quasiparticle density of states in dirty high-T_c superconductors
We study the density of quasiparticle states of dirty d-wave superconductors.
We show the existence of singular corrections to the density of states due to
quantum interference effects. We then argue that the density of states actually
vanishes in the localized phase as or depending on whether time
reversal is a good symmetry or not. We verify this result for systems without
time reversal symmetry in one dimension using supersymmetry techniques. This
simple, instructive calculation also provides the exact universal scaling
function for the density of states for the crossover from ballistic to
localized behaviour in one dimension. Above two dimensions, we argue that in
contrast to the conventional Anderson localization transition, the density of
states has critical singularities which we calculate in a
expansion. We discuss consequences of our results for various experiments on
dirty high- materials
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