Brain-computer interface (BCI) aims to establish communication paths between the brain processes and external devices. Different methods have been used to extract human intentions from ...electroencephalography (EEG) recordings. Those based on motor imagery (MI) seem to have a great potential for future applications. These approaches rely on the extraction of EEG distinctive patterns during imagined movements. Techniques able to extract patterns from raw signals represent an important target for BCI as they do not need labor-intensive data pre-processing.
We propose a new approach based on a 10-layer one-dimensional convolution neural network (1D-CNN) to classify five brain states (four MI classes plus a 'baseline' class) using a data augmentation algorithm and a limited number of EEG channels. In addition, we present a transfer learning method used to extract critical features from the EEG group dataset and then to customize the model to the single individual by training its late layers with only 12-min individual-related data.
The model tested with the 'EEG Motor Movement/Imagery Dataset' outperforms the current state-of-the-art models by achieving a99.38%accuracy at the group level. In addition, the transfer learning approach we present achieves an average accuracy of99.46%.
The proposed methods could foster the development of future BCI applications relying on few-channel portable recording devices and individual-based training.
We report an experimental test of the photodetection mechanism in a nanowire superconducting single photon detector. Detector tomography allows us to explore the 0.8-8 eV energy range via multiphoton ...excitations. High accuracy results enable a detailed comparison of the experimental data with theories for the mechanism of photon detection. We show that the temperature dependence of the efficiency of the superconducting single photon detector is determined not by the critical current but by the current associated with vortex unbinding. We find that both quasiparticle diffusion and vortices play a role in the detection event.
The development of performant integrated detectors, which are sensitive to quantum fluctuations of coherent light, are strongly desired to realize a scalable and determinist photonic quantum ...processor based on continuous variables states of light. Here, we investigate the performance of hot electron bolometers (HEBs) fabricated on top of a silicon-on-insulator (SOI) photonic circuit showing responsivities up to 8600 V/W and a record noise equivalent temperature of 1.1 dB above the quantum limit. Thanks to a detailed analysis of the noise sources of the waveguide integrated HEB, we estimate 14.8 dBV clearance between the shot noise and electrical noise with just 1.1µW of local oscillator power. The full technology compatibility with superconducting nanowire single photon detectors (SNSPDs) opens the possibility of nonclassical state engineering and state tomography performed within the same platform, enabling a new class of optical quantum processors.
Silicon carbide (SiC) is a promising candidate as a material platform for photonic quantum technologies due to the coexistence of quantum emitters and a non-centrosymmetric crystal structure. The ...realization of a single-photon detector was hampered from both the poor surface quality and the difficulties in micromachining this material. In this work, we realized superconducting nanowire single-photon detectors (SNSPDs) integrated on top of high-quality 3C SiC whose electro-optical characterization was performed thanks to a novel alignment method. We demonstrate that SNSPDs with high internal efficiency can be fabricated which is a fundamental building block toward the realization of complex architectures in this platform.
The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous
measurements from two spacecraft, offering an unprecedented opportunity to investigate
magnetospheric and exospheric particle ...dynamics at Mercury as well as their interactions
with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA
(Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space
on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for
ion and neutral particle detection aboard the MPO. It comprises four independent sensors:
ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for
planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA
is managed by a System Control Unit located inside the ELENA box. In the present paper
the scientific goals of this suite are described, and then the four units are detailed, as well
as their major features and calibration results. Finally, the SERENA operational activities
are shown during the orbital path around Mercury, with also some reference to the activities
planned during the long cruise phase.
We present an experimental method to characterize multi-photon detectors with a small overall detection efficiency. We do this by separating the nonlinear action of the multiphoton detection event ...from linear losses in the detector. Such a characterization is a necessary step for quantum information protocols with single and multiphoton detectors and can provide quantitative information to understand the underlying physics of a given detector. This characterization is applied to a superconducting multiphoton nanodetector, consisting of an NbN nanowire with a bowtie-shaped subwavelength constriction. Depending on the bias current, this detector has regimes with single and multiphoton sensitivity. We present the first full experimental characterization of such a detector.
In this work we present the results of the fabrication and characterization of a large area Superconducting Nanowire Single Photon Detector (SNSPD). A particular geometry was adopted to enhance the ...coupling with the Lidar system MALIA (Multiwavelength Lidar Apparatus), a setup used for atmospheric aerosols observations from ultraviolet to infrared. The devices realized are very promising as they exhibit a very low dead time despite the large sensitive area.
•In laryngeal oncology it is crucial to assess mobility of vocal cord-arytenoid unit.•Current mobility assessment is flawed by weak inter-observer agreement.•Tumor extension assessment by dedicated ...radiologists is recommended.
In clinical practice the assessment of the “vocal cord-arytenoid unit” (VCAU) mobility is crucial in the staging, prognosis, and choice of treatment of laryngeal squamous cell carcinoma (LSCC). The aim of the present study was to measure repeatability and reliability of clinical assessment of VCAU mobility and radiologic analysis of posterior laryngeal extension.
In this multi-institutional retrospective study, patients with LSCC-induced impairment of VCAU mobility who received curative treatment were included; pre-treatment endoscopy and contrast-enhanced imaging were collected and evaluated by raters. According to their evaluations, concordance, number of assigned categories, and inter- and intra-rater agreement were calculated.
Twenty-two otorhinolaryngologists evaluated 366 videolaryngoscopies (total evaluations: 2170) and 6 radiologists evaluated 237 imaging studies (total evaluations: 477). The concordance of clinical rating was excellent in only 22.7% of cases. Overall, inter- and intra-rater agreement was weak. Supraglottic cancers and transoral endoscopy were associated with the lowest inter-observer reliability values. Radiologic inter-rater agreement was low and did not vary with imaging technique. Intra-rater reliability of radiologic evaluation was optimal.
The current methods to assess VCAU mobility and posterior extension of LSCC are flawed by weak inter-observer agreement and reliability. Radiologic evaluation was characterized by very high intra-rater agreement, but weak inter-observer reliability. The relevance of VCAU mobility assessment in laryngeal oncology should be re-weighted. Patients affected by LSCC requiring imaging should be referred to dedicated radiologists with experience in head and neck oncology.
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