2,478 research outputs found
Robust Transcoding Sensory Information With Neural Spikes
Neural coding, including encoding and decoding, is one of the key problems in neuroscience for understanding how the brain uses neural signals to relate sensory perception and motor behaviors with neural systems. However, most of the existed studies only aim at dealing with the continuous signal of neural systems, while lacking a unique feature of biological neurons, termed spike, which is the fundamental information unit for neural computation as well as a building block for brain-machine interface. Aiming at these limitations, we propose a transcoding framework to encode multi-modal sensory information into neural spikes and then reconstruct stimuli from spikes. Sensory information can be compressed into 10% in terms of neural spikes, yet re-extract 100% of information by reconstruction. Our framework can not only feasibly and accurately reconstruct dynamical visual and auditory scenes, but also rebuild the stimulus patterns from functional magnetic resonance imaging (fMRI) brain activities. More importantly, it has a superb ability of noise immunity for various types of artificial noises and background signals. The proposed framework provides efficient ways to perform multimodal feature representation and reconstruction in a high-throughput fashion, with potential usage for efficient neuromorphic computing in a noisy environment
Exploiting Radio Fingerprints for Simultaneous Localization and Mapping
Simultaneous localization and mapping (SLAM) is paramount for unmanned
systems to achieve self-localization and navigation. It is challenging to
perform SLAM in large environments, due to sensor limitations, complexity of
the environment, and computational resources. We propose a novel approach for
localization and mapping of autonomous vehicles using radio fingerprints, for
example WiFi (Wireless Fidelity) or LTE (Long Term Evolution) radio features,
which are widely available in the existing infrastructure. In particular, we
present two solutions to exploit the radio fingerprints for SLAM. In the first
solution-namely Radio SLAM, the output is a radio fingerprint map generated
using SLAM technique. In the second solution-namely Radio+LiDAR SLAM, we use
radio fingerprint to assist conventional LiDAR-based SLAM to improve accuracy
and speed, while generating the occupancy map. We demonstrate the effectiveness
of our system in three different environments, namely outdoor, indoor building,
and semi-indoor environment.Comment: This paper has been accepted by IEEE Pervasive Computing with DOI:
10.1109/MPRV.2023.327477
Pairing in the iron arsenides: a functional RG treatment
We study the phase diagram of a microscopic model for the superconducting
iron arsenides by means of a functional renormalization group. Our treatment
establishes a connection between a strongly simplified two-patch model by
Chubukov et al. and a five-band- analysis by Wang et al.. For a wide parameter
range, the dominant pairing instability occurs in the extended s-wave channel.
The results clearly show the relevance of pair scattering between electron and
hole pockets. We also give arguments that the phase transition between the
antiferromagnetic phase for the undoped system and the superconducting phase
may be first order
form factors with 2+1 flavors
Using the MILC 2+1 flavor asqtad quark action ensembles, we are calculating
the form factors and for the semileptonic decay. A total of six ensembles with lattice spacing from
to 0.06 fm are being used. At the coarsest and finest lattice
spacings, the light quark mass is one-tenth the strange quark mass
. At the intermediate lattice spacing, the ratio ranges from
0.05 to 0.2. The valence quark is treated using the Sheikholeslami-Wohlert
Wilson-clover action with the Fermilab interpretation. The other valence quarks
use the asqtad action. When combined with (future) measurements from the LHCb
and Belle II experiments, these calculations will provide an alternate
determination of the CKM matrix element .Comment: 8 pages, 6 figures, to appear in the Proceedings of Lattice 2017,
June 18-24, Granada, Spai
form factors for new-physics searches from lattice QCD
The rare decay arises from flavor-changing
neutral currents and could be sensitive to physics beyond the Standard Model.
Here, we present the first - QCD calculation of the
tensor form factor . Together with the vector and scalar form factors
and from our companion work [J. A. Bailey , Phys. Rev. D
92, 014024 (2015)], these parameterize the hadronic contribution to
semileptonic decays in any extension of the Standard Model. We obtain the total
branching ratio in
the Standard Model, which is the most precise theoretical determination to
date, and agrees with the recent measurement from the LHCb experiment [R. Aaij
, JHEP 1212, 125 (2012)]. Note added: after this paper was submitted
for publication, LHCb announced a new measurement of the differential decay
rate for this process [T. Tekampe, talk at DPF 2015], which we now compare to
the shape and normalization of the Standard-Model prediction.Comment: V3: Corrected errors in results for Standard-Model differential and
total decay rates in abstract, Fig. 3, Table IV, and outlook. Added new
preliminary LHCb data to Fig. 3 and brief discussion after outlook. Replaced
outdated correlation matrix in Table III with correct final version. Other
minor wording changes and references added. 7 pages, 4 tables, 3 figure
decay form factors from three-flavor lattice QCD
We compute the form factors for the semileptonic decay
process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea
quark, generated by the MILC Collaboration. The ensembles span lattice spacings
from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the
chiral extrapolation. The asqtad improved staggered action is used for the
light valence and sea quarks, and the clover action with the Fermilab
interpretation is used for the heavy quark. We present results for the form
factors , , and , where is the momentum
transfer, together with a comprehensive examination of systematic errors.
Lattice QCD determines the form factors for a limited range of , and we
use the model-independent expansion to cover the whole kinematically
allowed range. We present our final form-factor results as coefficients of the
expansion and the correlations between them, where the errors on the
coefficients include statistical and all systematic uncertainties. We use this
complete description of the form factors to test QCD predictions of the form
factors at high and low . We also compare a Standard-Model calculation of
the branching ratio for with experimental data.Comment: V2: Fig.7 added. Typos text corrected. Reference added. Version
published in Phys. Rev.
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