94 research outputs found
Coherent Change Detection for repeated-pass interferometric SAR images: An application to earthquake damage assessment on buildings
During disaster response, the availability of relevant information, delivered in a proper format enabling its use among the different actors involved in response efforts, is key to lessen the impact of the disaster itself. Focusing on the contribution of geospatial information, meaningful advances have been achieved through the adoption of satellite earth observations within emergency management practices. Among these technologies, the Synthetic Aperture Radar (SAR) imaging has been extensively employed for large-scale applications such as flood areas delineation and terrain deformation analysis after earthquakes. However, the emerging availability of higher spatial and temporal resolution data has uncovered the potential contribution of SAR to applications at a finer scale. This paper proposes an approach to enable pixel-wise earthquake damage assessments based on Coherent Change Detection methods applied to a stack of repeated-pass interferometric SAR images. A preliminary performance assessment of the procedure is provided by processing Sentinel-1 data stack related to the 2016 central Italy earthquake for the towns of Amatrice and Accumoli. Damage assessment maps from photo-interpretation of high-resolution airborne imagery, produced in the framework of Copernicus EMS (Emergency Management Service - European Commission) and cross-checked with field survey, is used as ground truth for the performance assessment. Results show the ability of the proposed approach to automatically identify changes at an almost individual building level, thus enabling the possibility to empower traditional damage assessment procedures from optical imagery with the centimetric change detection sensitivity characterizing SAR. The possibility of disseminating outputs in a GIS-like format represents an asset for an effective and cross-cutting information sharing among decision makers and analysts
Development of an advanced modular setup for the on beam characterization of oriented crystals
Recently, the particle physics community has put an increasing effort in developing radiation detectors and equipment based on oriented crystals. A key feature that distinguishes an oriented crystal from the ordinary matter is the reduction of the radiation length (X0) seen by electrons, positrons and photons crossing the lattice along one of its symmetry axes. This effect has been experimentally observed only in the last few decades and with samples limited in number, composition and length. In order to characterize a variety of oriented crystals with a standardized procedure, the STORM Collaboration has developed an advanced modular setup, which allows to study the features of any crystal sample with both electron (or
positron) and photon beams. This contribution describes the key elements of this setup, namely silicon strip tracking detectors, plastic scintillators, Silicon PhotoMultipliers (SiPMs) coupled to the crystal under test, a photon calorimeter and an electromagnetic spectrometer
First results of the ALOS PALSAR verification processor
Among the several applications that will take advantage of the newly available data from the ALOS PALSAR instrument, considerable interest is in the peculiar features that derive from the penetration and polarimetric capabilities of the system.
These capabilities, new for a single spaceborne sensor, need specific software tools for the processing of the different acquisition modes. This paper presents a verification processor, developed under ESA contract, for the generation of polarimetric, interferometric and polarimetric-interferometric geocoded products derived from ALOS PALSAR data.
The processor, developed with a modular approach, contains the following main elements:
- Phase-preserving fine resolution processor; - Phase-preserving ScanSAR processor;
- Interference removal tools;
- Polarimetric calibration tools;
- Polarimetric analysis tools;
- Fine resolution interferometric processor; - ScanSAR interferometric processor;
- Polarimetric-interferometric processor;
- Geocoding;
- Atmospheric modelling tools.
The processor architecture is presented; highlights are given on specific modules and algorithms. Early results are shown, in particular of the processing of polarimetric and polarimetric-interferometric data over different test sites
Beam test, simulation, and performance evaluation of PbF and PWO-UF crystals with SiPM readout for a semi-homogeneous calorimeter prototype with longitudinal segmentation
Crilin (Crystal Calorimeter with Longitudinal Information) is a
semi-homogeneous, longitudinally segmented electromagnetic calorimeter based on
high-, ultra-fast crystals with UV-extended SiPM readout. The Crilin design
has been proposed as a candidate solution for both a future Muon Collider
barrel ECAL and for the Small Angle Calorimeter of the HIKE experiment. As a
part of the Crilin development program, we have carried out beam tests of small
(~mm) lead fluoride (PbF) and ultra-fast lead
tungstate (PbWO, PWO) crystals with 120~GeV electrons at the CERN SPS to
study the light yield, timing response, and systematics of light collection
with a proposed readout scheme. For a single crystal of PbF, corresponding
to a single Crilin cell, a time resolution of better than 25~ps is obtained for
3 GeV of deposited energy. For a single cell of \pwo, a time resolution of
better than 45~ps is obtained for the same range of deposited energy. This
timing performance fully satisfies the design requirements for the Muon
Collider and HIKE experiments. Further optimizations of the readout scheme and
crystal surface preparation are expected to bring further improvements
Development of an advanced modular setup for the on beam characterization of oriented crystals
Recently, the particle physics community has put an increasing effort in developing radiation detectors and equipment based on oriented crystals. A key feature that distinguishes an oriented crystal from the ordinary matter is the reduction of the radiation length (X0) seen by electrons, positrons and photons crossing the lattice along one of its symmetry axes. This effect has been experimentally observed only in the last few decades and with samples limited in number, composition and length. In order to characterize a variety of oriented crystals with a standardized procedure, the STORM Collaboration has developed an advanced modular setup, which allows to study the features of any crystal sample with both electron (or positron) and photon beams. This contribution describes the key elements of this setup, namely silicon strip tracking detectors, plastic scintillators, Silicon Photo-Multipliers (SiPMs) coupled to the crystal under test, a photon calorimeter and an electromagnetic spectrometer
Development of an advanced modular setup for the on beam characterization of oriented crystals
Recently, the particle physics community has put an increasing effort in developing radiation detectors and equipment based on oriented crystals. A key feature that distinguishes an oriented crystal from the ordinary matter is the reduc-tion of the radiation length (X0) seen by electrons, positrons and photons crossing the lattice along one of its symmetry axes. This effect has been experimentally ob-served only in the last few decades and with samples limited in number, composition and length. In order to characterize a variety of oriented crystals with a standardized procedure, the STORM Collaboration has developed an advanced modular setup, which allows to study the features of any crystal sample with both electron (or positron) and photon beams. This contribution describes the key elements of this setup, namely silicon strip tracking detectors, plastic scintillators, Silicon Photo -Multipliers (SiPMs) coupled to the crystal under test, a photon calorimeter and an electromagnetic spectrometer
A highly-compact and ultra-fast homogeneous electromagnetic calorimeter based on oriented lead tungstate crystals
Progress in high-energy physics has been closely tied to the development of high-performance electromagnetic calorimeters. Recent experiments have demonstrated the possibility to significantly accelerate the development of electromagnetic showers inside scintillating crystals typically used in homogeneous calorimeters based on scintillating crystals when the incident beam is aligned with a crystallographic axis to within a few mrad. In particular, a reduction of the radiation length has been measured when ultrarelativistic electron and photon beams were incident on a high-Z scintillator crystal along one of its main axes. Here, we propose the possibility to exploit this physical effect for the design of a new type of compact e.m. calorimeter, based on oriented ultra-fast lead tungstate (PWO-UF) crystals, with a significant reduction in the depth needed to contain electromagnetic showers produced by high-energy particles with respect to the state-of-the-art. We report results from tests of the crystallographic quality of PWO-UF samples via high-resolution X-ray diffraction and photoelastic analysis. We then describe a proof-of-concept calorimeter geometry defined with a Geant4 model including the shower development in oriented crystals. Finally, we discuss the experimental techniques needed for the realization of a matrix of scintillator crystals oriented along a specific crystallographic direction. Since the angular acceptance for e.m. shower acceleration depends little on the particle energy, while the decrease of the shower length remains pronounced at very high energy, an oriented crystal calorimeter will open the way for applications at the maximum energies achievable in current and future experiments. Such applications span from forward calorimeters, to compact beam dumps for the search for light dark matter, to source-pointing space-borne Îł-ray telescopes, to decrease the size and the cost of the calorimeter needed to fully contain e.m. showers initiated by GeV to TeV particles
Adherence to antibiotic treatment guidelines and outcomes in the hospitalized elderly with different types of pneumonia
Background: Few studies evaluated the clinical outcomes of Community Acquired Pneumonia (CAP), Hospital-Acquired Pneumonia (HAP) and Health Care-Associated Pneumonia (HCAP) in relation to the adherence of antibiotic treatment to the guidelines of the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) in hospitalized elderly people (65 years or older). Methods: Data were obtained from REPOSI, a prospective registry held in 87 Italian internal medicine and geriatric wards. Patients with a diagnosis of pneumonia (ICD-9 480-487) or prescribed with an antibiotic for pneumonia as indication were selected. The empirical antibiotic regimen was defined to be adherent to guidelines if concordant with the treatment regimens recommended by IDSA/ATS for CAP, HAP, and HCAP. Outcomes were assessed by logistic regression models. Results: A diagnosis of pneumonia was made in 317 patients. Only 38.8% of them received an empirical antibiotic regimen that was adherent to guidelines. However, no significant association was found between adherence to guidelines and outcomes. Having HAP, older age, and higher CIRS severity index were the main factors associated with in-hospital mortality. Conclusions: The adherence to antibiotic treatment guidelines was poor, particularly for HAP and HCAP, suggesting the need for more adherence to the optimal management of antibiotics in the elderly with pneumonia
Wake-active neurons across aging and neurodegeneration: a potential role for sleep disturbances in promoting disease
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