196,484 research outputs found
L'italiano tra le lingue d'Europa, Atti del Convegno Internazionale, (Firenze-Bologna 3-4.7.2007)
No full textI parte - La politica linguistica dell'Unione Europea attraverso i commenti del Commisario Ue al Multilinguismo, Leonard Orban, e dei funzionari della Commissione e del Dipartimento di Italiano; II parte - Traduzione e Interpretazione nella Ue: esperienze delle istituzioni europee e delle sedi universitarie di formazion
Environmental stress and flowering time: the photoperiodic connection
No full textPlants maximize their chances to survive adversities by reprogramming their development according to environmental conditions. Adaptive variations in the timing to flowering reflect the need for plants to set seeds under the most favorable conditions. A complex network of genetic pathways allows plants to detect and integrate external (e.g., photoperiod and temperature) and/or internal (e.g., age) information to initiate the floral transition. Furthermore different types of environmental stresses play an important role in the floral transition. The emerging picture is that stress conditions often affect flowering through modulation of the photoperiodic pathway. In this review we will discuss different modes of cross talk between stress signaling and photoperiodic flowering, highlighting the central role of the florigen genes in this process.Matteo Riboni, Alice Robustelli Test, Massimo Galbiati, Chiara Tonelli & Lucio
Cont
Structure-from-Motion 3D Reconstruction of the Historical Overpass Ponte della Cerra: A Comparison between MicMac® Open Source Software and Metashape®
No full textIn recent years, the performance of free-and-open-source software (FOSS) for image processing has significantly increased. This trend, as well as technological advancements in the unmanned aerial vehicle (UAV) industry, have opened blue skies for both researchers and surveyors. In this study, we aimed to assess the quality of the sparse point cloud obtained with a consumer UAV and a FOSS. To achieve this goal, we also process the same image dataset with a commercial software package using its results as a term of comparison. Various analyses were conducted, such as the image residuals analysis, the statistical analysis of GCPs and CPs errors, the relative accuracy assessment, and the Cloud-to-Cloud distance comparison. A support survey was conducted to measure 16 markers identified on the object. In particular, 12 of these were used as ground control points to scale the 3D model, while the remaining 4 were used as check points to assess the quality of the scaling procedure by examining the residuals. Results indicate that the sparse clouds obtained are comparable. MicMac® has mean image residuals equal to 0.770 pixels while for Metashape® is 0.735 pixels. In addition, the 3D errors on control points are similar: the mean 3D error for MicMac® is equal to 0.037 m with a standard deviation of 0.017 m, whereas for Metashape®, it is 0.031 m with a standard deviation equal to 0.015 m. The present work represents a preliminary study: a comparison between software packages is something hard to achieve, given the secrecy of the commercial software and the theoretical differences between the approaches. This case study analyzes an object with extremely complex geometry; it is placed in an urban canyon where the GNSS support can not be exploited. In addition, the scenario changes continuously due to the vehicular traffic
A low-cost multi-GNSS PPP-RTK solution for precision agriculture: a preliminary test
No full textThe agriculture and food sector will increasingly play a major role in the well-being of humanity. World-scale events, such as wars, climate changes, desertification, pandemic, etc., revealed how fragile humanity is from the point of view of food supply. Therefore, precision farming can provide a remarkable positive contribution to the primary sector globally at various levels. Nowadays, the employment of platforms for product data capture related to farming production and management is extensively available in several fields through local devices. Those systems comprehend sensors, automatic guidance systems with Global Navigation Satellite Systems (GNSSs), and central processing systems. Specifically, GNSS technology plays a central role in the autonomous guidance of tractors and farming robots. Until some years ago, high accuracy was a prerogative of expensive geodetic receivers whereas today high accuracy can be achieved also with low-cost receivers thanks to several factors, among all: the increased availability of GNSS interoperable constellations as well as the accessibility to several augmentation techniques both satellite-and ground-based. These factors are triggering the diffusion of autonomous machinery for farming purposes. This research aims to investigate the performance of a commercial Precise Point Positioning-Real Time Kinematic (PPP-RTK) correction service, employing a low-cost receiver. Two tests have been carried out with two different-grade antennas (a geodetic and a low-cost one). The tests showed that the employment of cost-effective equipment along with the exploitation of correction services allows reaching subdecimetre-level precision in less than one minute when employing a geodetic antenna; accuracy slightly degrades to decimetre-level with the low-cost antenna but the integer ambiguity is resolved in less time. Mean time-to-fix attests to 57 s for test 1 (geodetic antenna) and 30 s for test 2 (low-cost antenna). The times to obtain the first float ambiguity solution are equal to about 15 s for both tests. Integer ambiguity fixed solutions reveal a DRMS of 0.09 m and 0.012 m for test 1 and test 2, respectively. Float solutions reach a DRMS of 0.45 m and 0.63 m for test 1 and test 2, respectively. Lastly, when corrections are not available at all, single point positioning solutions reveal a DRMS of 1.36 m for test 1 and 3.15 m for test 2
Low-Cost Hardware PPP-RTK AR Time-to-Fix and Positioning Performance Assessment: A Preliminary Static Test
No full textOver the last years, researchers are struggling to develop solutions and services for smart and sustainable urban mobility creating dynamic shared spaces for both vehicles and pedestrians. Also, the deployment of autonomous vehicles has boosted the interest in precise, accurate, and robust position, navigation, and timing (PNT). Most of these services will be based primarily on the location of the vehicle relative to other vehicles, objects, and pedestrians in its vicinity. Therefore, the importance of a robust, ubiquitous, and reliable PNT can’t be overlooked. In the mass-market scenario, the challenge will be developing low-cost navigation equipment capable of providing navigation solutions that meet the accuracy, integrity, continuity, and availability requirements. This paper reports some preliminary tests aiming to investigate the phase-ambiguity fixing performance of a commercial precise point positioning real-time kinematic (PPP-RTK) correction service, employing a low-cost receiver. To assess the ambiguity resolution performance, we forced the receiver to restart the ambiguity search generating enough samples for statistic analysis. In this test, PPP-RTK has revealed a promising technique for decimetre-level accuracy positioning with low-cost receivers. Integer ambiguity fixed solutions reveal a DRMS of 0.09 m whereas float solutions reveal a DRMS of 0.45 m. When PPP-RTK corrections are not available, SPP/DGNSS solutions reveal a DRMS of 1.36 m. The test showed that the employment of cost-effective equipment along with the exploitation of correction services allows reaching decimetre/sub-metre accuracy in about 20 s and sub-decimetre accuracy in about 2 min once the integer ambiguity is fixed
A Reference Grammar of Modern Italian
No full textThis grammar makes effective use of current assumptions in linguistics and of recent advances in the description of the Italian language. It also includes original observations and analysis not avilable elsewhere. This second edition provides scholars, students and teachers with a comprehensive and accessible guide to the forms and structures of Italian. It has been completely revised, largely rewritten and contains a new section of the differences in registers between written and spoken Italian, updates to the sections on causatives and on conjunctions and an extended glossary
Introduzione [Le lingue d'Europa patrimonio comune dei cittadini europei]
No full textCommento ai temi trattati nel volume:- applicazione concreta del multilinguismo nella politica interna e estera- promozione della comunicazione multilingue nei singoli stati della Ue- adozione erispetto del multilinguismo a livello locale e regional
Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits
No full textOn August 2016, the Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. As the Galileo constellation is not yet complete. It is very important to have two more satellites available since the position accuracy increases as the number of visible satellites increases. In this article, we examine how the inclusion of the Milena (E14) and Doresa (E18) satellites impacts the position accuracy. The analysis was carried out on 20 days of 1-Hz observations collected by a receiver placed in YEL2IGS (International GNSS service) station. Two different scenarios are considered: the first excludes the measurements coming from the analyzed satellites, while the second one includes them. The analysis was conducted by using a suitable software tool developed in the MATLAB® environment able to compute satellites position from both the broadcast and precise ephemerides, to assess DOP (Dilution Of Precision) parameters and to compute single-point positioning for all Galileo frequencies. The analyses are conducted by using both broadcast and precise ephemeris. The inclusion of the two satellites improves the system availability, varying it from 94.1–97.94%, the DOP parameters, and the percentages of achieved positioning solutions by about 5% regardless of the frequency used. Nevertheless, in the positioning domain, when the broadcast ephemerides are used, the inclusion of the satellites worsens both the horizontal and vertical accuracy of the solution. The deterioration of the horizontal accuracy goes from 0.17 m with E5a frequency measurements to 0.74 m with E1 measurements. The reduction of vertical accuracy goes from 0.68 m for E5a to 1.2 m for E1 measurements. However, if precise ephemerides are used, both the horizontal and the vertical accuracy remain stable, actually for the E5b frequency, the DRMS (Distance Root Mean Squared) improves by almost 0.5 m. The results achieved show that the real drawback to overcome is related to the quality of broadcast ephemeris as, when precise ephemeris are used, the number of solutions achieved is increased by about 5% with an accuracy similar to that obtained when the satellites are excluded
Realizzazione di un sistema di geolocalizzazione web-based in ambiente open source mediante l’impiego dell’infrastruttura tecnologica della rete gsm-sms
No full textOggetto di questa tesi è stato la realizzazione di un sistema integrato che consente la localizzazione in tempo reale degli utenti ad un
pubblico vasto come quello di internet, senza la necessità di utilizzare alcun software se non un semplice browser, ad un costo molto
ridotto.
Il principio di funzionamento è il seguente: un utente munito di un ricevitore GPS integrato con un modem GSM invia la propria
posizione ad un server WEB attraverso la rete GSM mediante l’invio di un messaggio di testo (SMS) nel formato NMEA0183.
Questa informazione viene inserita in un geodatabase consentendo al software di rendering cartografico l’interpretazione del dato ed
il posizionamento corretto su di una cartografia di sfondo.
Tutti coloro che sono abilitati (mediante una procedura di autenicazione) possono localizzare l’utente del sistema che ha inviato
l’SMS collegandosi semplicemente ad un sito internet. Da questa breve descrizione si evince come l’architettura con la quale è stato
progettato il sistema di geolocalizzazione riduca drasticamente i costi di gestione in quanto è sufficiente inviare un solo SMS per
poter localizzare la posizione di un utente. Va sottolineato che tra gli obbiettivi che ci si è posti durante la realizzazione del sistema
integrato non è presente sicuramente un elevata accuratezza posizionale. Infatti questo sistema è orientato ad un utilizzazione in real
time, da parte di un numero elevato utenti, quindi una accuratezza posizionale 10 m è stata giudicata più che sufficiente
La costruzione della lingua unitaria
No full textIl lungo lavoro di revisione e arricchimento che Pellegrino Artusi compie sulla sua opera maggiore, "La Scienza in cucina e l’Arte di mangiar bene. Manuale pratico per le famiglie", viene qui riletto alla luce della costruzione in dimensione unitaria della lingua italiana, lungo quei vent’anni (1891-1911) che vedranno sostanziarsi di contenuti le fondamenta dell’unità nazionale, disegnate sul piano politico ma non ancora incise nel pensiero e nelle consuetudini di vita dei suoi abitanti
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