63 research outputs found
LLM Based Multi-Agent Generation of Semi-structured Documents from Semantic Templates in the Public Administration Domain
In the last years' digitalization process, the creation and management of
documents in various domains, particularly in Public Administration (PA), have
become increasingly complex and diverse. This complexity arises from the need
to handle a wide range of document types, often characterized by
semi-structured forms. Semi-structured documents present a fixed set of data
without a fixed format. As a consequence, a template-based solution cannot be
used, as understanding a document requires the extraction of the data
structure. The recent introduction of Large Language Models (LLMs) has enabled
the creation of customized text output satisfying user requests. In this work,
we propose a novel approach that combines the LLMs with prompt engineering and
multi-agent systems for generating new documents compliant with a desired
structure. The main contribution of this work concerns replacing the commonly
used manual prompting with a task description generated by semantic retrieval
from an LLM. The potential of this approach is demonstrated through a series of
experiments and case studies, showcasing its effectiveness in real-world PA
scenarios.Comment: Accepted at HCI INTERNATIONAL 2024 - 26th International Conference on
Human-Computer Interaction. Washington Hilton Hotel, Washington DC, USA, 29
June - 4 July 202
Fall Detection using NAO Robot Pose Estimation in RoboCup SPL Matches
RoboCup is an International robotics initiative whose aim is to promote robotics and AI research. RoboCup's long-term goal is to create a fully autonomous humanoid robot team capable of competing and winning a soccer game against the human World champion team, in compliance with the official rules of FIFA, by 2050. In this paper, we describe a two-step method for action recognition. In the first step, we extract the pose of the robots using a pose detector trained on a novel dataset for pose estimation called UNIBAS NAO Pose Dataset, which is a contribution of this work. In the second step, a Spatial-Temporal Graph Convolutional Network is used for modeling the gameplay, with particular regard to fall-down detection. Experimental results show the effectiveness of our approach in detecting falls for humanoid robots
Development, manufacturing, and testing of Ariel’s structural model prototype flexure hinges
The Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (Ariel) is the M4 mission adopted by ESA's "Cosmic Vision" program. Its launch is scheduled for 2029. The mission aims to study exoplanetary atmospheres on a target of ∼ 1000 exoplanets. Ariel's scientific payload consists of an off-axis, unobscured Cassegrain telescope. The light is directed towards a set of photometers and spectrometers with wavebands between 0.5 and 7.8 μm and operating at cryogenic temperatures. The Ariel Space Telescope consists of a primary parabolic mirror with an elliptical aperture of 1.1· 0.7 m, all bare aluminum. To date, aluminum mirrors the size of Ariel's primary have never been made. In fact, a disadvantage of making mirrors in this material is its low density, which facilitates deformation under thermal and mechanical stress of the optical surface, reducing the performance of the telescope. For this reason, studying each connection component between the primary mirror and the payload is essential. This paper describes, in particular, the development, manufacturing, and testing of the Flexure Hinges to connect Ariel's primary Structural Model mirror and its optical bench. The Flexure Hinges are components already widely used for space telescopes, but redesigning from scratch was a must in the case of Ariel, where the entire mirror and structures are made of aluminum. In fact, these flexures, as well as reducing the stress due to the connecting elements and the launch vibrations and maintaining the alignment of all the parts preventing plastic deformations, amplified for aluminum, must also have resonance frequencies different from those usually used, and must guarantee maximum contact (tolerance in the order of a micron) for the thermal conduction of heat. The entire work required approximately a year of work by the Ariel mechanical team in collaboration with the industry
Aluminum based large telescopes: the ARIEL mission case
Ariel (Atmospheric Remote-Sensing Infrared Exoplanet Large Survey) is the adopted M4 mission of ESA “Cosmic Vision” program. Its purpose is to conduct a survey of the atmospheres of known exoplanets through transit spectroscopy. Launch is scheduled for 2029. Ariel scientific payload consists of an off-axis, unobscured Cassegrain telescope feeding a set of photometers and spectrometers in the waveband between 0.5 and 7.8 µm, and operating at cryogenic temperatures. The Ariel Telescope consists of a primary parabolic mirror with an elliptical aperture of 1.1 m of major axis, followed by a hyperbolic secondary, a parabolic recollimating tertiary and a flat folding mirror. The Primary mirror is a very innovative device made of lightened aluminum. Aluminum mirrors for cryogenic instruments and for space application are already in use, but never before now it has been attempted the creation of such a large mirror made entirely of aluminum: this means that the production process must be completely revised and fine-tuned, finding new solutions, studying the thermal processes and paying a great care to the quality check. By the way, the advantages are many: thermal stabilization is simpler than with mirrors made of other materials based on glass or composite materials, the cost of the material is negligeable, the shape may be free and the possibility of making all parts of the telescope, from optical surfaces to the structural parts, of the same material guarantees a perfect alignment at whichever temperature. The results and expectations for the flight model are discussed in this paper
Consolidation of surface charging analyses on the Ariel payload dielectrics in the early transfer orbit and L2 space environments
Ariel (Atmospheric Remote Sensing Infrared Exoplanet Large Survey) [1] [2] is the fourth Mission (M4) of the ESA’s Cosmic Vision Program 2015-2025, selected in March 2018 and officially adopted in November 2020 by the Agency, whose aim is to characterize the atmospheres of hundreds of diverse exoplanets orbiting nearby different types of stars and to identify the key factors affecting the formation and evolution of planetary systems. The Mission will have a nominal duration of four years and a possible extension of two years at least. Its launch is presently scheduled for mid 2029 from the French Guiana Space Centre in Kourou on board an Ariane 6.2 launcher in a dual launch configuration with Comet Interceptor. The baseline operational orbit of the Ariel is a large amplitude halo orbit around the second Lagrangian (L2) virtual point located along the line joining the Sun and the Earth-Moon system at about 1.5 million km (~236 RE) from the Earth in the anti-Sun direction. Ariel’s halo orbit is designed to be an eclipse-free orbit as it offers the possibility of long uninterrupted observations in a fairly stable environment (thermal, radiation, etc.). An injection trajectory is foreseen with a single passage through the Van Allen radiation belts (LEO, MEO and GEO near-Earth environments). This is approximated by a worst-case half orbit, prior the injection and transfer to L2, with a duration of 10.5 hours, a perigee of 300 km (LEO), an apogee of 64000 km (GEO and beyond), and an inclination close to 0 degrees. During both the injection trajectory and the final orbit around L2, Ariel will encounter and interact mainly with the Sun radiation and the space plasma environment. In L2 the Ariel spacecraft will spend most of its time in the direct solar wind and the Earth’s magnetosheath with passages through the magnetotail. These three environments, along with LEO and GEO, can lead to the build-up of a net electric charge on the spacecraft and payload conductive and dielectric surfaces leading to the risk of Electro Static Discharges (ESD), potentially endangering the whole Payload integrity and telecommunications to Ground
The electrical design of the thermal control systems of the all-aluminum ARIEL telescope
The Atmospheric Remote-sensing InfraRed Large-survey (ARIEL) is a medium-class mission of the European Space Agency whose launch is planned by late 2029 whose aim is to study the composition of exoplanet atmospheres, their formation and evolution. The ARIEL’s target will be a sample of about 1000 planets observed with one or more of the following methods: transit, eclipse and phase-curve spectroscopy, at both visible and infrared wavelengths simultaneously. The scientific payload is composed by a reflective telescope having a 1m-class primary mirror, built in solid aluminum, and two focal-plane instruments: 1. FGS (Fine Guidance System), performing photometry in visible light and low resolution spectrometry over three bands (from 0.8 to 1.95 µm) 2. AIRS (ARIEL InfraRed Spectrometer) that will perform infrared spectrometry in two wavelength ranges between 1.95 and 7.8 µm. This paper depicts the status of the TA (Telescope Assembly) electric section whose purpose is to deploy sensors, managed by the Telescope Control Unit, for the precise monitoring of the Telescope’s temperatures and the decontamination system, used to avoid the contamination of the optical surfaces (mirrors in primis)
In-flight calibration system of imaging x-ray polarimetry explorer
The NASA/ASI Imaging X-ray Polarimetry Explorer, which will be launched in 2021, will be the first instrument to perform spatially resolved X-ray polarimetry on several astronomical sources in the 2-8 keV energy band. These measurements are made possible owing to the use of a gas pixel detector (GPD) at the focus of three X-ray telescopes. The GPD allows simultaneous measurements of the interaction point, energy, arrival time, and polarization angle of detected X-ray photons. The increase in sensitivity, achieved 40 years ago, for imaging and spectroscopy with the Einstein satellite will thus be extended to X-ray polarimetry for the first time. The characteristics of gas multiplication detectors are subject to changes over time. Because the GPD is a novel instrument, it is particularly important to verify its performance and stability during its mission lifetime. For this purpose, the spacecraft hosts a filter and calibration set (FCS), which includes both polarized and unpolarized calibration sources for performing in-flight calibration of the instruments. In this study, we present the design of the flight models of the FCS and the first measurements obtained using silicon drift detectors and CCD cameras, as well as those obtained in thermal vacuum with the flight units of the GPD. We show that the calibration sources successfully assess and verify the functionality of the GPD and validate its scientific results in orbit; this improves our knowledge of the behavior of these detectors in X-ray polarimetry
The Demonstration Model of the ATHENA X-IFU Cryogenic AntiCoincidence Detector
The Cryogenic AntiCoincidence detector (CryoAC) of ATHENA X-IFU is designed to reduce the particle background of the instrument and to enable the mission science goals. It is a 4-pixel silicon microcalorimeter sensed by an Ir/Au TES network. We have developed the CryoAC demonstration model, a prototype aimed to probe the critical technologies of the detector, i.e., the suspended absorber with an active area of 1 cm2; the low energy threshold of 20 keV; and the operation connected to a 50 mK thermal bath with a power dissipation less than 40 nW. Here, we report the test performed on the first CryoAC DM sample (namely, the AC-S10 prototype), showing that it is fully compliant with its requirements
FEA testing the pre-flight Ariel primary mirror
Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is an ESA M class mission aimed at the study of exoplanets. The satellite will orbit in the lagrangian point L2 and will survey a sample of 1000 exoplanets simultaneously in visible and infrared wavelengths. The challenging scientific goal of Ariel implies unprecedented engineering efforts to satisfy the severe requirements coming from the science in terms of accuracy. The most important specification – an all-Aluminum telescope – requires very accurate design of the primary mirror (M1), a novel, off-set paraboloid honeycomb mirror with ribs, edge, and reflective surface. To validate such a mirror, some tests were carried out on a prototype – namely Pathfinder Telescope Mirror (PTM) – built specifically for this purpose. These tests, carried out at the Centre Spatial de Liège in Belgium – revealed an unexpected deformation of the reflecting surface exceeding a peek-to-valley of 1µm. Consequently, the test had to be re-run, to identify systematic errors and correct the setting for future tests on the final prototype M1. To avoid the very expensive procedure of developing a new prototype and testing it both at room and cryogenic temperatures, it was decided to carry out some numerical simulations. These analyses allowed first to recognize and understand the reasoning behind the faults occurred during the testing phase, and later to apply the obtained knowledge to a new M1 design to set a defined guideline for future testing campaigns
The Cryogenic AntiCoincidence Detector for ATHENA X-IFU: The Project Status
The ATHENA observatory is the second large class ESA mission to be launched on 2031 at L2 orbit. One of the two onboard instruments is X-IFU, a TES-based kilo-pixel array able to perform simultaneous high-grade energy spectroscopy (FWHM 2.5 eV@7 keV) and imaging over the 5' field of view. The X-IFU sensitivity is degraded by primary particle background of both solar and galactic cosmic ray (GCR) origins, and by secondary electrons produced by primaries, interacting with the materials surrounding the detector: These particles cannot be distinguished by the scientific photons, thus degrading the instrument performance. Results from studies regarding the GCR component performed by Geant4 simulations address the necessity to use background reduction techniques to enable the study of several key science topics. This is feasible by combining an active Cryogenic AntiCoincidence detector (CryoAC) and a passive electron shielding to reach the required residual particle background of 0.005 cts/cm2/s/keV inside the 2-10 keV scientific energy band. The CryoAC is a four-pixel detector made of Si-suspended absorbers sensed by a network of IrAu TESes and placed at a distance < 1 mm below the TES array. Here we will provide an overview of the CryoAC program, starting with some details on the background assessment having impacts on the CryoAC design; then, we continue with its design concept including electronics and the Demonstration Model results, to conclude with programmatic aspects
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