325 research outputs found
Abnormal Rolls and Regular Arrays of Disclinations in Homeotropic Electroconvection
We present the first quantitative verification of an amplitude description
for systems with (nearly) spontaneously broken isotropy, in particular for the
recently discovered abnormal-roll states. We also obtain a conclusive picture
of the 3d director configuration in a spatial period doubling phenomenon
involving disclination loops (CRAZY rolls). The first observation of two
Lifshitz frequencies in electroconvection is reported.Comment: 4 pages; 4 figure
Modeling the growth of fingerprints improves matching for adolescents
We study the effect of growth on the fingerprints of adolescents, based on
which we suggest a simple method to adjust for growth when trying to recover a
juvenile's fingerprint in a database years later. Based on longitudinal data
sets in juveniles' criminal records, we show that growth essentially leads to
an isotropic rescaling, so that we can use the strong correlation between
growth in stature and limbs to model the growth of fingerprints proportional to
stature growth as documented in growth charts. The proposed rescaling leads to
a 72% reduction of the distances between corresponding minutiae for the data
set analyzed. These findings were corroborated by several verification tests.
In an identification test on a database containing 3.25 million right index
fingers at the Federal Criminal Police Office of Germany, the identification
error rate of 20.8% was reduced to 2.1% by rescaling. The presented method is
of striking simplicity and can easily be integrated into existing automated
fingerprint identification systems
Breaking the resilience of a two-dimensional Bose-Einstein condensate to fragmentation
A two-dimensional Bose-Einstein condensate (BEC) split by a radial potential
barrier is investigated. We determine on an accurate many-body level the
system's ground-state phase diagram as well as a time-dependent phase diagram
of the splitting process. Whereas the ground state is condensed for a wide
range of parameters, the time-dependent splitting process leads to substantial
fragmentation. We demonstrate for the first time the dynamical fragmentation of
a BEC despite its ground state being condensed. The results are analyzed by a
mean-field model and suggest that a large manifold of low-lying fragmented
excited states can significantly impact the dynamics of trapped two-dimensional
BECs.Comment: 5+eps pages, 4 figure
Adversarial Diffusion Distillation
We introduce Adversarial Diffusion Distillation (ADD), a novel training
approach that efficiently samples large-scale foundational image diffusion
models in just 1-4 steps while maintaining high image quality. We use score
distillation to leverage large-scale off-the-shelf image diffusion models as a
teacher signal in combination with an adversarial loss to ensure high image
fidelity even in the low-step regime of one or two sampling steps. Our analyses
show that our model clearly outperforms existing few-step methods (GANs, Latent
Consistency Models) in a single step and reaches the performance of
state-of-the-art diffusion models (SDXL) in only four steps. ADD is the first
method to unlock single-step, real-time image synthesis with foundation models.
Code and weights available under
https://github.com/Stability-AI/generative-models and
https://huggingface.co/stabilityai/
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