1,463 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
Infrared propagators of Yang-Mills theory from perturbation theory
We show that the correlation functions of ghosts and gluons for the pure
Yang-Mills theory in Landau gauge can be accurately reproduced for all momenta
by a one-loop calculation. The key point is to use a massive extension of the
Faddeev-Popov action. The agreement with lattice simulation is excellent in
d=4. The one-loop calculation also reproduces all the characteristic features
of the lattice simulations in d=3 and naturally explains the pecularities of
the propagators in d=2.Comment: 4 pages, 4 figures
Hi ha una història social de la llengua catalana?
La lingĂĽĂstica històrica ha produĂŻt al llarg de l'Ăşltimsegle estudis notables sobre l'evoluciĂł formal
de la llengua catalana. A mĂ©s, en les Ăşltimes dècades s'ha desenvolupat una sociolingĂĽĂstica
catalana que connecta la teoria i la descripciĂł empĂrica amb la polĂtica lingĂĽĂstica. No
obstant això, no s'ha gestat una història social de la llengua, o una sociolingĂĽĂstica històrica en
sentit estricte, més enllà d'alguns esforços individuals. Les raons d'aquest dèficit són internes
(les limitacions de l'objecte d'estudi, la inèrcia i l'estancament dels estudis filològics...) i externes
(els condicionants sociopolĂtics i de mercat que pesen sobre el catalĂ ). Per això es proposa
avançar cap a un nou paradigma en què la diacronia lingĂĽĂstica s'integri dins de les
ciències socials, obertes a l'autocrĂtica i la superaciĂł de l'apriorisme ideològic.Does the Catalan language have a social history?. Over the last century, historical linguistics has produced notable studies on the formal evolution
of the Catalan language.Moreover, in recent decades Catalan sociolinguistics has been
developed, connecting theory and empirical description to language policy. However, a social
history of the Catalan language has not been developed nor historical sociolinguistics,
strictly speaking, bar a few random examples. The reasons for this deficit are both internal
(the limitations of the subject matter, the inertia and the stagnation of philological studiesÂ…)
and external (the socio-political andmarket constraints imposed on the Catalan language).
We therefore propose to move towards a new paradigm in which the linguistic diachrony
is integrated within social sciences, open to self-criticism and to overcoming ideological
apriorism
Transport and invariant manifolds near L3 in the Earth-Moon Bicircular model
This paper focuses on the role of to organise trajectories for a particle going from Earth to Moon and viceversa, and entering or leaving the Earth-Moon system. As a first model, we have considered the planar Bicircular problem to account for the gravitational effect of the Sun on the particle. The first step has been to compute a family of hyperbolic quasi-periodic orbits near . Then, the computation of their stable and unstable manifolds provides connections between Earth and Moon, and also generates trajectories that enter and leave the Earth-Moon system. Finally, by means of numerical simulations based on the JPL ephemeris we show that these connections can guide the journey of lunar ejecta towards the Earth
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