5,551 research outputs found
Multigranular scale speech recognition: tehnological and cognitive view
We propose a Multigranular Automatic Speech Recognizer. The hypothesis is that
speech signal contains information distributed on more different time scales.
Many works from various scientific fields ranging from neurobiology to speech
technologies, seem to concord on this assumption. In a broad sense, it seems
that speech recognition in human is optimal because of a partial
parallelization process according to which the left-to-right stream of
speech is captured in a multilevel grid in which several linguistic analyses take
place contemporarily. Our investigation aims, in this view, to apply these new
ideas to the project of more robust and efficient recognizers
Testing Convolutional Neural Networks for finding strong gravitational lenses in KiDS
Convolutional Neural Networks (ConvNets) are one of the most promising
methods for identifying strong gravitational lens candidates in survey data. We
present two ConvNet lens-finders which we have trained with a dataset composed
of real galaxies from the Kilo Degree Survey (KiDS) and simulated lensed
sources. One ConvNet is trained with single \textit{r}-band galaxy images,
hence basing the classification mostly on the morphology. While the other
ConvNet is trained on \textit{g-r-i} composite images, relying mostly on
colours and morphology. We have tested the ConvNet lens-finders on a sample of
21789 Luminous Red Galaxies (LRGs) selected from KiDS and we have analyzed and
compared the results with our previous ConvNet lens-finder on the same sample.
The new lens-finders achieve a higher accuracy and completeness in identifying
gravitational lens candidates, especially the single-band ConvNet. Our analysis
indicates that this is mainly due to improved simulations of the lensed
sources. In particular, the single-band ConvNet can select a sample of lens
candidates with purity, retrieving 3 out of 4 of the confirmed
gravitational lenses in the LRG sample. With this particular setup and limited
human intervention, it will be possible to retrieve, in future surveys such as
Euclid, a sample of lenses exceeding in size the total number of currently
known gravitational lenses.Comment: 16 pages, 10 figures. Accepted for publication in MNRA
A collimation system for ELI-NP Gamma Beam System - design and simulation of performance
The purpose of this study was to evaluate the performance and refine the design of the collimation system for the gamma radiation source (GBS) currently being realised at ELI-NP facility. The gamma beam, produced by inverse Compton scattering, will provide a tunable average energy in the range between 0.2 and 20 MeV, an energy bandwidth 0.5% and a flux of about 108 photons/s. As a result of the inverse Compton interaction, the energy of the emitted radiation is related to the emission angle, it is maximum in the backscattering direction and decreases as the angle increase [1,2]. Therefore, the required energy bandwidth can be obtained only by developing a specific collimation system of the gamma beam, i.e. filtering out the radiation emitted at larger angles. The angular acceptance of the collimation for ELI-NP-GBS must be continuously adjustable in a range from about 700 to 60 μrad, to obtain the required parameters in the entire energy range. The solution identified is a stack of adjustable slits, arranged with a relative rotation around the beam axis to obtain an hole with an approximately circular shape. In this contribution, the final collimation design and its performance evaluated by carrying out a series of detailed Geant4 simulations both of the high-energy and the low-energy beamline are presented
Inspections of accredited workshops: Some Italian experiences
Among the activities established by the Directive 128/09 and by NAP (National Action Plan), a periodical inspection by authorities is addressed to official workshops in charge of sprayer inspections.In this paper we describe activities carried out by two Italian regions (Umbria and Campania) that have recently started a regular activity for the inspection of workshops. An inspection procedure according to technical national guidelines (ENAMA documents) was prepared in collaboration with regional authorities and CRA-ING, that is in charge of technical aspects of inspections. The approach, the key elements and some results of inspections are reported in the paper
Biliary injuries after pancreatic surgery: Interventional radiology management
Bile duct injuries are among the most feared complications after pancreatic surgery. Most of these surgical complications are related to iatrogenic injuries and include bile leakage, biliary duct obstruction or stricture and infection. A wide range of Interventional Radiology treatment options are currently available. The options include percutaneous transhepatic cholangiography (PTC), percutaneous transhepatic biliary drainage (PTBD), percutaneous balloon dilatation and stenting, image-guided percutaneous abscess drainage. The purpose of this review is to describe the current evidence in this continuously evolving field
High repetition rate and coherent Free-Electron Laser in the tender X-rays based on the Echo-Enabled Harmonic Generation of an Ultra-Violet Oscillator pulse
Fine time-resolved analysis of matter - i.e. spectroscopy and photon
scattering - in the linear response regime requires a fs-scale pulsed, high
repetition rate, fully coherent X-ray source. A seeded Free-Electron Laser
(FEL) driven by a Super-Conducting Linac, generating -
coherent photons at 2-5 keV with abou 0.5 MHz of repetition rate, can address
this need. The seeding scheme proposed is the Echo-Enabled Harmonic Generation,
alimented by a FEL Oscillator working at 13.6 nm with a cavity based on Mo-Si
mirrors. The whole chain of the X-ray generation is here described by means of
start-to-end simulations. Comparisons with the Self Amplified Spontaneus
Emission and a fresh-bunch harmonic cascade performed with similar electron
beams show the validity of this scheme
Discharge estimation in open channels by means of water level hydrograph analysis
A new methodology, based on the synchronous measurement of stage hydrographs in two river sections located some kilometers from each other, was developed to estimate the discharge hydrograph in the upstream section. The methodology is based on the one-parameter calibration of a numerical flow routing algorithm, solving the Saint-Venant equations in diffusive or complete form. The methodology was validated using results of laboratory experiments carried out at the Polytechnic of Bari University. A known discharge hydrograph was generated in the upstream tank of a rectangular flume, where two water level sensors were located. Two different bed materials have been used, to account for different roughness coefficients. Eight measured discharge hydrographs have been compared with the hydrographs computed using both a diffusive and a fully dynamic model. The diffusive model provides a good estimate of the measured discharge in the experiments with the highest roughness value
Sars-cov-2 detection in fecal sample from a patient with typical findings of covid-19 pneumonia on ct but negative to multiple sars-cov-2 rt-pcr tests on oropharyngeal and nasopharyngeal swab samples
Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests’ results on samples from the upper respiratory tract
The impact of COVID-19 lockdown on admission to gynecological emergency departments: Results from a multicenter Italian study
Objective: To evaluate the impact of the COVID-19 lockdown on admissions to gynecological emergency departments (ED) of three Italian university hospitals with different rates of COVID-19 incidence. Methods: A retrospective study was conducted in the gynecological EDs of Modena (Emilia-Romagna), Sassari and Cagliari (Sardinia) regarding all admissions to gynecological EDs during November 1 to 30, 2019, and March 11 to April 9, 2020 (lockdown period). Results: A total of 691 women (mean age 38.3 \ub1 14.3 years) who were admitted to the gynecological EDs were included. The relative decrease in women evaluated from March 11 to April 9, 2020, was 1256.6% (95% confidence interval [CI] 52.2\u201361.1). Time spent in the ED was also significantly shorter during this period (P=0.02) in comparison to November 1 to 30, 2019. The most evident decrease was observed for pelvic pain ( 1268.9% [95% CI 60.3\u201376.7]; 1291 cases). The management of women suggests a more effective use of the ED, with higher rates of hospitalization (P=0.001) and recourse to emergent surgeries (P=0.005) and lower rates of discharge to home (P=0.03). Conclusion: The COVID-19 lockdown greatly reduced the rate of admission to gynecological EDs, but the real emergencies were filtered from the more deferrable ones
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