7,546 research outputs found
RED: Deep Recurrent Neural Networks for Sleep EEG Event Detection
The brain electrical activity presents several short events during sleep that
can be observed as distinctive micro-structures in the electroencephalogram
(EEG), such as sleep spindles and K-complexes. These events have been
associated with biological processes and neurological disorders, making them a
research topic in sleep medicine. However, manual detection limits their study
because it is time-consuming and affected by significant inter-expert
variability, motivating automatic approaches. We propose a deep learning
approach based on convolutional and recurrent neural networks for sleep EEG
event detection called Recurrent Event Detector (RED). RED uses one of two
input representations: a) the time-domain EEG signal, or b) a complex
spectrogram of the signal obtained with the Continuous Wavelet Transform (CWT).
Unlike previous approaches, a fixed time window is avoided and temporal context
is integrated to better emulate the visual criteria of experts. When evaluated
on the MASS dataset, our detectors outperform the state of the art in both
sleep spindle and K-complex detection with a mean F1-score of at least 80.9%
and 82.6%, respectively. Although the CWT-domain model obtained a similar
performance than its time-domain counterpart, the former allows in principle a
more interpretable input representation due to the use of a spectrogram. The
proposed approach is event-agnostic and can be used directly to detect other
types of sleep events.Comment: 8 pages, 5 figures. In proceedings of the 2020 International Joint
Conference on Neural Networks (IJCNN 2020
Invariant and polynomial identities for higher rank matrices
We exhibit explicit expressions, in terms of components, of discriminants,
determinants, characteristic polynomials and polynomial identities for matrices
of higher rank. We define permutation tensors and in term of them we construct
discriminants and the determinant as the discriminant of order , where
is the dimension of the matrix. The characteristic polynomials and the
Cayley--Hamilton theorem for higher rank matrices are obtained there from
Violencia de género en las universidades o la necesidad de una intervención educativa
En la Universidad de Burgos se ha llevado a cabo un estudio piloto entre un grupo de alumnas
y alumnos en que se pone de manifiesto que hay indicios de Violencia de Género, pero también que
algunas conductas no se reconocen como Violencia de Género. Por otra parte, sus fuentes de
Comunicación, la Opinión Pública e Internet.At the University of Burgos has been conducted a pilot study among a group of students. The
result shows there is evidence of Gender Violence, but also that some behaviors are not recognized
as Gender Violence. Moreover, sources of information on this subject are fundamentally Media,
Public Opinion and the Internet
Optimal scheme for estimating a pure qubit state via local measurements
We present the optimal scheme for estimating a pure qubit state by means of
local measurements on N identical copies. We give explicit examples for low N.
For large N, we show that the fidelity saturates the collective measurement
bound up to order 1/N. When the signal state lays on a meridian of the Bloch
sphere, we show that this can be achieved without classical communication.Comment: Version to appear in PRL (minor changes, title changed
Wave localization in strongly nonlinear Hertzian chains with mass defect
We investigate the dynamical response of a mass defect in a one-dimensional
non-loaded horizontal chain of identical spheres which interact via the
nonlinear Hertz potential. Our experiments show that the interaction of a
solitary wave with a light intruder excites localized mode. In agreement with
dimensional analysis, we find that the frequency of localized oscillations
exceeds the incident wave frequency spectrum and nonlinearly depends on the
size of the intruder and on the incident wave strength. The absence of tensile
stress between grains allows some gaps to open, which in turn induce a
significant enhancement of the oscillations amplitude. We performed numerical
simulations that precisely describe our observations without any adjusting
parameters.Comment: 4 pages, 5 figures, submitted for publicatio
Standardization of molecular monitoring for chronic myeloid leukemia in Latin America using locally produced secondary cellular calibrators
Residual disease in chronic myeloid leukemia (CML) patients undergoing therapy with tyrosine kinase inhibitors (TKIs) is measured by assessing the quantity of transcripts of the BCR-ABL1 fusion gene in peripheral white blood cells. This analysis is based on reverse-transcription quantitative PCR (RT–qPCR) technology; however, the wide array of methods used worldwide has led to large variation in quantitative BCR-ABL1 measurements, which hamper inter-laboratory comparative studiesFil: Ruiz, María Sol. Fundación Cáncer. Centro de Investigaciones Oncológicas; ArgentinaFil: Medina, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Tapia, I.. Fundación Cáncer. Centro de Investigaciones Oncológicas; ArgentinaFil: Mordoh, Jose. Fundación Cáncer. Centro de Investigaciones Oncológicas; ArgentinaFil: Cross, N. C. P.. Universidad de Southampton Uk; Reino UnidoFil: Larripa, Irene Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Bianchini, Michele. Fundación Cáncer. Centro de Investigaciones Oncológicas; Argentin
Multi-copy programmable discrimination of general qubit states
Quantum state discrimination is a fundamental primitive in quantum statistics
where one has to correctly identify the state of a system that is in one of two
possible known states. A programmable discrimination machine performs this task
when the pair of possible states is not a priori known, but instead the two
possible states are provided through two respective program ports. We study
optimal programmable discrimination machines for general qubit states when
several copies of states are available in the data or program ports. Two
scenarios are considered: one in which the purity of the possible states is a
priori known, and the fully universal one where the machine operates over
generic mixed states of unknown purity. We find analytical results for both,
the unambiguous and minimum error, discrimination strategies. This allows us to
calculate the asymptotic performance of programmable discrimination machines
when a large number of copies is provided, and to recover the standard state
discrimination and state comparison values as different limiting cases.Comment: Based on version published in Physical Review A, some errors in
appendix A corrected. 13 pages, 4 figure
On the geometry of four qubit invariants
The geometry of four-qubit entanglement is investigated. We replace some of
the polynomial invariants for four-qubits introduced recently by new ones of
direct geometrical meaning. It is shown that these invariants describe four
points, six lines and four planes in complex projective space . For
the generic entanglement class of stochastic local operations and classical
communication they take a very simple form related to the elementary symmetric
polynomials in four complex variables. Moreover, their magnitudes are
entanglement monotones that fit nicely into the geometric set of -qubit ones
related to Grassmannians of -planes found recently. We also show that in
terms of these invariants the hyperdeterminant of order 24 in the four-qubit
amplitudes takes a more instructive form than the previously published
expressions available in the literature. Finally in order to understand two,
three and four-qubit entanglement in geometric terms we propose a unified
setting based on furnished with a fixed quadric.Comment: 19 page
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