14,665 research outputs found
Pigment Melanin: Pattern for Iris Recognition
Recognition of iris based on Visible Light (VL) imaging is a difficult
problem because of the light reflection from the cornea. Nonetheless, pigment
melanin provides a rich feature source in VL, unavailable in Near-Infrared
(NIR) imaging. This is due to biological spectroscopy of eumelanin, a chemical
not stimulated in NIR. In this case, a plausible solution to observe such
patterns may be provided by an adaptive procedure using a variational technique
on the image histogram. To describe the patterns, a shape analysis method is
used to derive feature-code for each subject. An important question is how much
the melanin patterns, extracted from VL, are independent of iris texture in
NIR. With this question in mind, the present investigation proposes fusion of
features extracted from NIR and VL to boost the recognition performance. We
have collected our own database (UTIRIS) consisting of both NIR and VL images
of 158 eyes of 79 individuals. This investigation demonstrates that the
proposed algorithm is highly sensitive to the patterns of cromophores and
improves the iris recognition rate.Comment: To be Published on Special Issue on Biometrics, IEEE Transaction on
Instruments and Measurements, Volume 59, Issue number 4, April 201
The Most Irrational Rational Theories
We propose a two-parameter family of modular invariant partition functions of
two-dimensional conformal field theories (CFTs) holographically dual to pure
three-dimensional gravity in anti de Sitter space. Our two parameters control
the central charge, and the representation of . At large
central charge, the partition function has a gap to the first nontrivial
primary state of . As the representation
dimension gets large, the partition function exhibits some of the qualitative
features of an irrational CFT. This, for instance, is captured in the behavior
of the spectral form factor. As part of these analyses, we find similar
behavior in the minimal model spectral form factor as approaches .Comment: 25 pages plus appendices, 11 figure
Quantum multiple gray scale images encryption scheme in the bit plane representation model
After introducing a bit-plane quantum representation for a multi-image, we
present a novel way to encrypt/decrypt multiple images using a quantum
computer. Our encryption scheme is based on a two-stage scrambling of the
images and of the bit planes on one hand and of the pixel positions on the
other hand, each time using quantum baker maps. The resulting quantum
multi-image is then diffused with controlled CNOT gates using a sine
chaotification of a two-dimensional H\'enon map as well as Chebyshev
polynomials. The decryption is processed by operating all the inverse quantum
gates in the reverse order.Comment: 19 pages, 5 figures, 2 appendice
Revealing quantum chaos with machine learning
Understanding properties of quantum matter is an outstanding challenge in
science. In this paper, we demonstrate how machine-learning methods can be
successfully applied for the classification of various regimes in
single-particle and many-body systems. We realize neural network algorithms
that perform a classification between regular and chaotic behavior in quantum
billiard models with remarkably high accuracy. We use the variational
autoencoder for autosupervised classification of regular/chaotic wave
functions, as well as demonstrating that variational autoencoders could be used
as a tool for detection of anomalous quantum states, such as quantum scars. By
taking this method further, we show that machine learning techniques allow us
to pin down the transition from integrability to many-body quantum chaos in
Heisenberg XXZ spin chains. For both cases, we confirm the existence of
universal W shapes that characterize the transition. Our results pave the way
for exploring the power of machine learning tools for revealing exotic
phenomena in quantum many-body systems.Comment: 12 pages, 12 figure
- …