1,372 research outputs found
Low temperature dephasing saturation from elastic magnetic spin disorder and interactions
We treat the question of the low temperature behavior of the dephasing rate
of the electrons in the presence of elastic spin disorder scattering and
interactions. In the frame of a self-consistent diagrammatic treatment, we
obtain saturation of the dephasing rate in the limit of low temperature for
magnetic scattering, in agreement with the non-interacting case. The magnitude
of the dephasing rate is set by the strength of the magnetic scattering rate.
We discuss the agreement of our results with relevant experiments.Comment: This paper supersedes cond-mat/021022
A large-scale evaluation framework for EEG deep learning architectures
EEG is the most common signal source for noninvasive BCI applications. For
such applications, the EEG signal needs to be decoded and translated into
appropriate actions. A recently emerging EEG decoding approach is deep learning
with Convolutional or Recurrent Neural Networks (CNNs, RNNs) with many
different architectures already published. Here we present a novel framework
for the large-scale evaluation of different deep-learning architectures on
different EEG datasets. This framework comprises (i) a collection of EEG
datasets currently including 100 examples (recording sessions) from six
different classification problems, (ii) a collection of different EEG decoding
algorithms, and (iii) a wrapper linking the decoders to the data as well as
handling structured documentation of all settings and (hyper-) parameters and
statistics, designed to ensure transparency and reproducibility. As an
applications example we used our framework by comparing three publicly
available CNN architectures: the Braindecode Deep4 ConvNet, Braindecode Shallow
ConvNet, and two versions of EEGNet. We also show how our framework can be used
to study similarities and differences in the performance of different decoding
methods across tasks. We argue that the deep learning EEG framework as
described here could help to tap the full potential of deep learning for BCI
applications.Comment: 7 pages, 3 figures, final version accepted for presentation at IEEE
SMC 2018 conferenc
Power Converters of the Main Dipole and Quadrupole Magnet Strings of the Antiproton Decelerator at CERN
The two main power converters for the dipoles (D) and quadrupoles (Q) are presented as part of the complex power converter system of the Antiproton Decelerator. The operational requirements and the performance specifications for deceleration from 3.5 to 0.1 GeV/c are discussed. The layout and design of the power part, consisting of a 12-pulse thyristor rectifier and a switch-mode parallel active filter (AF), and of the precision regulation are described. The alternatives for integrating the AF into the current and voltage regulation loops are outlined. Problems encountered and results of tests are reported
Side-entrainment in a jet embedded in a sidewind
Numerical simulations of HH jets never show side-entrainment of environmental
material into the jet beam. This is because the bow shock associated with the
jet head pushes the surrounding environment into a dense shell, which is never
in direct contact with the sides of the jet beam. We present 3D simulations in
which a side-streaming motion (representing the motion of the outflow source
through the surrounding medium) pushes the post-bow shock shell into direct
contact with the jet beam. This is a possible mechanism for modelling well
collimated "molecular jets" as an atomic/ionic flow which entrains molecules
initially present only in the surrounding environment.Comment: 8 pages, 12 figures, 1 table, accepted for publication in Ap
EFFECT OF DIFFERENT LOW BACK TRAINING PROGRAMS ON LUMBAR SPINE KINESTHESIA
Reduced kinesthetic perceptions can impair lower back sensorimotor functions and result in increased injury risk. The effect of low back training programs on lumbar spine kinesthetic sensibility is undetermined. There was a back strengthening exercise group (with low back pain; training 4.4 h/wk), a “classical” back training program group (with low back pain; training 4.9 h/wk) and a control group (training 5.4 h/wk). During an active reproduction test, subjects performed trunk positions in random order: flexion [A(0°-20°), B(20°-40°)], lateral flexion [C(0°-30°)], Using a 3D-ultrasound motion analysis system the repositioning error was calculated from the given target position to the subject perceived target position, before and after a 5 week training period. Results show decreased repositioning error after the training for both training groups
SPECIFIC TRAINING CAN IMPROVE SENSORIMOTOR CONTROL IN TYPE 2 DIABETIC PATIENTS
Diabetes mellitus often is associated with proprioceptive and sensory deficits as a result of distal diabetic polyneuropathy (DPN). The aim of this prospective controlled longitudinal trial was to evaluate a specific sport intervention program regarding sensorimotor capabilities in type 2 diabetic patients compared to healthy controls. A higher incidence of fall-related injuries is given in the literature (Allet et al.2008; Allet et al 2009)
Towards Quantum Sensing of Chiral-Induced Spin Selectivity: Probing Donor-Bridge-Acceptor Molecules with NV Centers in Diamond
Photoexcitable donor-bridge-acceptor (D-B-A) molecules that support
intramolecular charge transfer are ideal platforms to probe the influence of
chiral-induced spin selectivity (CISS) in electron transfer and resulting
radical pairs. In particular, the extent to which CISS influences spin
polarization or spin coherence in the initial state of spin-correlated radical
pairs following charge transfer through a chiral bridge remains an open
question. Here, we introduce a quantum sensing scheme to measure directly the
hypothesized spin polarization in radical pairs using shallow nitrogen-vacancy
(NV) centers in diamond at the single- to few-molecule level. Importantly, we
highlight the perturbative nature of the electron spin-spin dipolar coupling
within the radical pair, and demonstrate how Lee-Goldburg decoupling can
preserve spin polarization in D-B-A molecules for enantioselective detection by
a single NV center. The proposed measurements will provide fresh insight into
spin selectivity in electron transfer reactions.Comment: 7 pages and 4 pages appendix including an extensive description of
the initial spin state of photo-generated radical pair
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