286 research outputs found
Integrating Foundational Data Management Course into STEM
This presentation was delivered at the IOLUG conference-Tackling Data in Libraries: Opportunities and Challenges in Serving User Communities in Indianapolis, IN in May 2019. Data literacy is critical for today’s college graduates. Data science education is fundamentally an interdisciplinary endeavor. Since summer 2018, the presenters, information professionals from the libraries, have been working with instructors from Philosophy and Computer and Electrical Engineering to develop three interlocking one-credit courses at the Midwest, public research university, Purdue University. Spring 2019, the courses are offered to engineering sophomore and junior students to explore three key areas of data literacy: management; ethics; and analysis. In this session, participants learned how we developed the libraries’ one-credit course on data management and we discussed how this course could be interlocked with two other courses. Welcome to contact and work with the presenters for class implementation and research collaboration
Search for Lambda^2/p^2 corrections to the QCD running coupling
We investigate the occurrence of power terms in the running
QCD coupling by analysing non-perturbative measurements of at
quite low momenta obtained from the lattice three-gluon vertex. Our study
provides some evidence for such a contribution. The phenomenological
implications of such a presence are reviewed.Comment: 3 pages, 1 figure, LaTeX, LATTICE98(Confinement
Monopole clusters at short and large distances
We present measurements of various geometrical characteristics of monopole
clusters in SU(2) lattice gauge theory. The maximal Abelian projection is
employed and both infinite, or percolating cluster and finite clusters are
considered. In particular, we observe scaling for average length of segments of
the percolating cluster between self-crossings, correlators of vacuum monopole
currents, angular correlation between links along trajectories. Short clusters
are random walks and their spectrum in length corresponds to free particles. At
the hadronic scale, on the other hand, the monopole trajectories are no longer
random walks. Moreover, we argue that the data on the density of finite
clusters suggest that there are long-range correlations between finite clusters
which can be understood as association of the clusters with two-dimensional
surfaces, whose area scales.Comment: 9 pages, 11 figure
Valley Bifurcation in an Model: Implications for High-Energy Baryon Number Violation
The valley method for computing the total high-energy anomalous cross section
is the extension of the optical theorem to the case of
instanton-antiinstanton backgrounds. As a toy model for baryon number violation
in Electroweak theory, we consider a version of the model in
which the conformal invariance is broken perturbatively. We show that at a
critical energy the saddle-point values of the instanton size and
instanton-antiinstanton separation bifurcate into complex conjugate pairs. This
nonanalytic behavior signals the breakdown of the valley method at an energy
where is still exponentially suppressed.
(Figures replaced 5/3/93).Comment: (14 pages, Los Alamos Preprint LA-UR-93-811). 3 uuencoded figures
include
Stopping Light on a Defect
Gap solitons are localized nonlinear coherent states which have been shown
both theoretically and experimentally to propagate in periodic structures.
Although theory allows for their propagation at any speed , ,
they have been observed in experiments at speeds of approximately 50% of .
It is of scientific and technological interest to trap gap solitons. We first
introduce an explicit multiparameter family of periodic structures with
localized defects, which support linear defect modes. These linear defect modes
are shown to persist into the nonlinear regime, as {\it nonlinear defect
modes}. Using mathematical analysis and numerical simulations we then
investigate the capture of an incident gap soliton by these defects. The
mechanism of capture of a gap soliton is resonant transfer of its energy to
nonlinear defect modes. We introduce a useful bifurcation diagram from which
information on the parameter regimes of gap soliton capture, reflection and
transmission can be obtained by simple conservation of energy and resonant
energy transfer principles.Comment: 45 pages, Submitted to Journal of the Optical Society
HAAR: Text-Conditioned Generative Model of 3D Strand-based Human Hairstyles
We present HAAR, a new strand-based generative model for 3D human hairstyles.
Specifically, based on textual inputs, HAAR produces 3D hairstyles that could
be used as production-level assets in modern computer graphics engines. Current
AI-based generative models take advantage of powerful 2D priors to reconstruct
3D content in the form of point clouds, meshes, or volumetric functions.
However, by using the 2D priors, they are intrinsically limited to only
recovering the visual parts. Highly occluded hair structures can not be
reconstructed with those methods, and they only model the ''outer shell'',
which is not ready to be used in physics-based rendering or simulation
pipelines. In contrast, we propose a first text-guided generative method that
uses 3D hair strands as an underlying representation. Leveraging 2D visual
question-answering (VQA) systems, we automatically annotate synthetic hair
models that are generated from a small set of artist-created hairstyles. This
allows us to train a latent diffusion model that operates in a common hairstyle
UV space. In qualitative and quantitative studies, we demonstrate the
capabilities of the proposed model and compare it to existing hairstyle
generation approaches.Comment: For more results please refer to the project page
https://haar.is.tue.mpg.de
Homogeneous AlGaN/GaN superlattices grown on free-standing (1(1)over-bar00) GaN substrates by plasma-assisted molecular beam epitaxy
Two-dimensional and homogeneous growth of m-plane AlGaN by plasma-assisted molecular beam epitaxy has been realized on free-standing (1 (1) over bar 00) GaN substrates by implementing high metal-to-nitrogen (III/N) flux ratio. AlN island nucleation, often reported for m-plane AlGaN under nitrogen-rich growth conditions, is suppressed at high III/N flux ratio, highlighting the important role of growth kinetics for adatom incorporation. The homogeneity and microstructure of m-plane AlGaN/GaN superlattices are assessed via a combination of scanning transmission electron microscopy and high resolution transmission electron microscopy (TEM). The predominant defects identified in dark field TEM characterization are short basal plane stacking faults (SFs) bounded by either Frank-Shockley or Frank partial dislocations. In particular, the linear density of SFs is approximately 5 x 10(-5) cm(-1), and the length of SFs is less than 15 nm. (C) 2013 AIP Publishing LLC
Flux-Tube Formation and Holographic Tunneling
We consider correlator of two concentric Wilson loops, a small and large ones
related to the problem of flux-tube formation. There are three mechanisms which
can contribute to the connected correlator and yield different dependences on
the radius of the small loop. The first one is quite standard and concerns
exchange by supergravity modes. We also consider a novel mechanism when the
flux-tube formation is described by a barrier transition in the string
language, dual to the field-theoretic formulation of Yang-Mills theories. The
most interesting possibility within this approach is resonant tunneling which
would enhance the correlator of the Wilson loops for particular geometries. The
third possibility involves exchange by a dyonic string supplied with the string
junction. We introduce also t'Hooft and composite dyonic loops as probes of the
flux tube. Implications for lattice measurements are briefly discussed.Comment: 15 pages, 3 figure
A novel probe of the vacuum of the lattice gluodynamics
We introduce a notion of minimal number of negative links on the lattice for
a given original configuration of SU(2) fields. Negative links correspond to a
large potential, not necessarily large action. The idea is that the minimal
number of negative links is a gauge invariant notion. To check this hypothesis
we measure correlator of two negative links, averaged over all the directions,
as function of the distance between the links. The inverse correlation length
coincides within the error bars with the lightest glueball mass.Comment: 6 pages, 2 figure
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