776 research outputs found
Spatial anomaly detection in InSAR data
LAUREA MAGISTRALELa rappresentazione dell’andamento dei fenomeni nel corso del tempo può essere ottenuta
mediante l’utilizzo delle serie temporali. La loro analisi consente di individuare eventuali
situazioni critiche, identificando i cambiamenti che si registrano all’interno delle stesse
serie temporali. Il rilevamento di tali cambiamenti, anche noto come "rilevamento dei
punti di cambiamento". L’andamento del suolo terrestre viene studiato attraverso le
serie temporali di deformazione del terreno, ottenute attraverso immagini satellitari che
orbitano attorno alla Terra. I metodi attualmente esistenti che si occupano di rilevamento
di cambiamenti eseguono unicamente un’analisi temporale sulle singole serie. Il nostro
obbiettivo è introdurre un analisi spaziare nello studio delle serie temporali InSAR al
fine di migliorare le prestazioni dei modelli esistenti. Questo è possibile dato che a ogni
serie temporale InSAR corrisponde un punto fisso sulla superficie terrestre. Dato che un
cambiamento si propaga nel suolo, è possibile combinare i punti che presentano lo stesso
cambiamento. L’oggetto di questo lavoro è l’implementazione di modelli di correlazione
spazialenel campo del rilevamento dei cambi di comporamento nelle immagini InSAR.
Viene riportata la teoria fondamentale sui modelli matematici impiegati, una spiegazione
su cosa sia una immagine SAR e come viene utilizzata al fine di rilevari cambiamenti di
moto nel terreno. Dalla nostra ricerca si osserva che trovare una implementazione corretta
non è un problema da sottovalutare, il costo massiccio di risorse richiesto dai modelli
rocorrenti rende complicata la ricerca di una architettura funzionale ai fini preposti. La
soluzione da noi proposta si basa su una rete Graph Neural Network capace di combinare
le caratteristiche di ogni nodo sia nel tempo che nello spazio.The representation of phenomena over time can be achieved using time series, with their
analysis identifying critical situations or identifying changes within the same time series,
known as "change point detection." Land surface deformation is studied through InSAR
time series obtained from satellite imagery orbiting the Earth. Existing methods for
change detection only perform temporal analysis on individual time series. Our objective
is to introduce spatial analysis in the study of ground deformation time series to improve
existing model performance. This is possible as each InSAR time series corresponds to a
fixed point on the Earth’s surface, and a change can propagate through the ground, al-
lowing for the combination of points with the same change. The focus of this work is the
implementation of spatial correlation models for detecting changes in behavior in InSAR
images. The fundamental theory on mathematical models used is provided, along with
an explanation of what a SAR image is and how it is used to detect changes in ground
motion. Our research highlights that finding the correct implementation is not a problem
to be underestimated, as the massive resource cost required by recurrent models makes it
complicated to find an architecture functional for the identified purposes. Our proposed
solution is based on a Graph Neural Network that can combine each node’s features in
both space and time
Detection of avian influenza virus in the alien invasive African sacred ibis (Threskiornis aethiopicus) in Italy
The African sacred ibis (Threskiornis aethiopicus), a non-native bird species in Europe, has rapidly expanded its range in Italy, prompting the adoption of national control measures due to ecological and epidemiological concerns. As part of this management plan, 20 ibises were culled in February 2025 in Tuscany (Central Italy), and tested for pathogens relevant to wildlife and public health. RT-PCR and molecular analyses on tracheal and cloacal swabs, revealed the presence of low pathogenic avian influenza virus (LPAIV) subtype H5N2 in 1 out of 20 specimens. Phylogenetic analysis showed that the virus was closely related to recent European LPAIV strains, with the PA gene segment clustered with Asian and Russian isolates from 2021–2022. Two mammalian adaptation markers (S155N and T156A) were identified in the HA protein. Although the detected strain poses minimal zoonotic risk, its presence in a highly adaptable invasive species, raises concerns about the potential role of T. aethiopicus as a bridge host in avian influenza transmission cycles. Given the increasing overlap between this species and poultry farming areas, and its scavenging behavior, continued surveillance is essential to assess its epidemiological role. Targeted control actions may be crucial in preventing the establishment of novel wildlife reservoirs and limiting viral evolution towards highly pathogenic forms. Surveillance of alien invasive species should be integrated into broader avian influenza monitoring strategies to protect public health and agricultural biosecurity
Performance of a spaghetti calorimeter prototype with tungsten absorber and garnet crystal fibres
A spaghetti calorimeter (SPACAL) prototype with scintillating crystal fibres
was assembled and tested with electron beams of energy from 1 to 5 GeV. The
prototype comprised radiation-hard Cerium-doped GdAlGaO
(GAGG:Ce) and YAlO (YAG:Ce) embedded in a pure tungsten
absorber. The energy resolution was studied as a function of the incidence
angle of the beam and found to be of the order of ,
in line with the LHCb Shashlik technology. The time resolution was measured
with metal channel dynodes photomultipliers placed in contact with the fibres
or coupled via a light guide, additionally testing an optical tape to glue the
components. Time resolution of a few tens of picosecond was achieved for all
the energies reaching down to (18.5 0.2) ps at 5 GeV.Comment: 14 pages, 8 figures, published on NIM
Prototyping a Cloud Ecosystem for a Regional Public Administration
In this paper we present the lessons learned in the deployment of a Cloud solution in the Marche Region Local Public Administration, which represents one of the pilot experiences at National level. The MarcheCloud (MCloud) pilot Project, started in mid-2012 as a joint collaboration among the Marche Region, National Institute of Nuclear Physics (INFN), University of Camerino and Polytechnic University of Marche
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
INDIGO-DataCloud: A data and computing platform to facilitate seamless access to e-infrastructures
This paper describes the achievements of the H2020 project INDIGO-DataCloud. The project has provided e-infrastructures with tools, applications and cloud framework enhancements to manage the demanding requirements of scientific communities, either locally or through enhanced interfaces. The middleware developed allows to federate hybrid resources, to easily write, port and run scientific applications to the cloud. In particular, we have extended existing PaaS (Platform as a Service) solutions, allowing public and private e-infrastructures, including those provided by EGI, EUDAT, and Helix Nebula, to integrate their existing services and make them available through AAI services compliant with GEANT interfederation policies, thus guaranteeing transparency and trust in the provisioning of such services. Our middleware facilitates the execution of applications using containers on Cloud and Grid based infrastructures, as well as on HPC clusters. Our developments are freely downloadable as open source components, and are already being integrated into many scientific applications
Enhancing Light Extraction of Inorganic Scintillators Using Photonic Crystals
Inorganic scintillators are commonly used as sensors for ionizing radiation detectors in a variety of applications, ranging from particle and nuclear physics detectors, medical imaging, nuclear installations radiation control, homeland security, well oil logging and a number of industrial non-destructive investigations. For all these applications, the scintillation light produced by the energy deposited in the scintillator allows the determination of the position, the energy and the time of the event. However, the performance of these detectors is often limited by the amount of light collected on the photodetector. A major limitation comes from the fact that inorganic scintillators are generally characterized by a high refractive index, as a consequence of the required high density to provide the necessary stopping power for ionizing radiation. The index mismatch between the crystal and the surrounding medium (air or optical grease) strongly limits the light extraction efficiency because of total internal reflection (TIR), increasing the travel path and the absorption probability through multiple bouncings of the photons in the crystal. Photonic crystals can overcome this problem and produce a controllable index matching between the crystal and the output medium through an interface made of a thin nano-structured layer of optically-transparent high index material. This review presents a summary of the works aiming at improving the light collection efficiency of scintillators using photonic crystals since this idea was introduced 10 years ago
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