Hall effect encoding of brushless dc motors

Encoding mechanism integral to the motor and using the permanent magnets embedded in the rotor eliminates the need for external devices to encode information relating the position and velocity of the rotating member

A Theory of Sampling for Continuous-time Metric Temporal Logic

This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to "flat" formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete-time, resulting in an automated partial practically-efficient discretization technique.Comment: Revised version, 43 pages

The engineering roles of requirements and specification

The distinction between requirements and specification is often confused in practice. This obstructs the system validation process, because it is unclear what exactly should be validated, and against what it should be validated. The reference model of Gunter et al. addresses this difficulty by providing a framework within which requirements can be distinguished from specification. It separates world phenomena from machine phenomena. However, it does not explain how the characterization can be used to help assure system validity. In this paper, we enhance the reference model to account for certain key elements that are necessary to expose and clarify the distinction and the link between requirements and specification. We use the enhanced version to present a more refined picture of validity, where validation has two steps that can be undertaken separately. We use this picture to question whether the “what the system will do, not how it will do it ” paradigm is useful in describing how to construct a specification, and propose an alternative. Finally, we present the requirements and specification for an illustrative example based on a runway incursion prevention system, with the ArchiTRIO formal language in a UML-like environment, to show how this might be done in practice.

A computational search for box C/D snoRNA genes in the Drosophila melanogaster genome

Abstract Motivation: In eukaryotes, the family of non-coding RNA genes includes a number of genes encoding small nucleolar RNAs (mainly C/D and H/ACA snoRNAs), which act as guides in the maturation or post-transcriptional modifications of target RNA molecules. Since in Drosophila melanogaster (Dm) only few examples of snoRNAs have been identified so far by cDNA libraries screening, integration of the molecular data with in silico identification of these types of genes could throw light on their organization in the Dm genome. Results: We have performed a computational screening of the Dm genome for C/D snoRNA genes, followed by experimental validation of the putative candidates. Few of the 26 confirmed snoRNAs had been recognized by cDNA library analysis. Organization of the Dm genome was also found to be more variegated than previously suspected, with snoRNA genes nested in both the introns and exons of protein-coding genes. This finding suggests that the presence of additional mechanisms of snoRNA biogenesis based on the alternative production of overlapping mRNA/snoRNA molecules. Availability: Additional information is available at http://www.bioinformatica.unito.it/bioinformatics/snoRNA

Appropriateness of frequent use of emergency departments: A retrospective analysis in Rome, Italy

Background: Frequent users (FUs) are patients who repeatedly and inappropriately visit the emergency department (ED) for low-grade symptoms that could be treated outside the hospital setting. This study aimed to investigate the phenomenon of the FU in Rome by profiling such users and analyzing ED attendance by FUs. Methods: The analysis was carried out for attendance in 2021 at 15 EDs in the Local Health Authority Roma 1 geographical area. A digital app collected data, including information on the following variables: number of attendance, demographic characteristics, emergency medical service (EMS) usage, triage code, and appropriateness of attendance. COVID-19 diagnosis was also studied to analyze any possible influence on ED attendance. Differences between FUs and non-FUs were investigated statistically by t-test and chi-square test. Univariate analysis and multivariable logistic regression were performed to analyze the associated factors. Results: A total of 122,762 ED attendance and 89,036 users were registered. The FU category represented 2.9% of all users, comprising 11.9% of total ED attendance. There was a three times higher frequency of non-urgent codes in attendance of FU patients (FU: 9.7%; non-FU: 3.2%). FUs were slightly more likely to have used the EMS (13.6% vs. 11.4%) and had a lower frequency of appropriate ED attendance (23.8% vs. 27.0%). Multivariate logistic analysis confirmed a significant effect of triage code, gender, age, EMS usage, and COVID-19 diagnosis for the appropriateness of attendance. The results were statistically significant (p < 0.001). Conclusion: The FU profile describes mostly non-urgent and inappropriate attendance at the ED, including during the COVID-19 pandemic. This study represents an important tool for strengthening preventive policies outside the hospital setting. The Italian National Recovery and Resilience Plan represents an excellent opportunity for the development of new strategies to mitigate the phenomenon of FUs

Robustness Testing of Intermediate Verifiers

Program verifiers are not exempt from the bugs that affect nearly every piece of software. In addition, they often exhibit brittle behavior: their performance changes considerably with details of how the input program is expressed-details that should be irrelevant, such as the order of independent declarations. Such a lack of robustness frustrates users who have to spend considerable time figuring out a tool's idiosyncrasies before they can use it effectively. This paper introduces a technique to detect lack of robustness of program verifiers; the technique is lightweight and fully automated, as it is based on testing methods (such as mutation testing and metamorphic testing). The key idea is to generate many simple variants of a program that initially passes verification. All variants are, by construction, equivalent to the original program; thus, any variant that fails verification indicates lack of robustness in the verifier. We implemented our technique in a tool called "mugie", which operates on programs written in the popular Boogie language for verification-used as intermediate representation in numerous program verifiers. Experiments targeting 135 Boogie programs indicate that brittle behavior occurs fairly frequently (16 programs) and is not hard to trigger. Based on these results, the paper discusses the main sources of brittle behavior and suggests means of improving robustness

“ALLA SCOPERTA dei TESORI del MARE” - Scienza e Tecnologia, Memoria Popolare e Identità Culturale di una città della costa ligure

“Il dovere degli scienziati non è quello di educare il pubblico, ma piuttosto di interagire con esso. Il pubblico è la vera forza trainante dietro decisioni con conseguenze sociali, e deve essere coinvolto su base paritaria nei dibattiti inerenti queste decisioni” . La comunicazione scientifica e tecnologica fra scienza e società, da anni, non è più un mero scambio di informazioni e risultati (spesso fra determinate élite), ma è diventata il veicolo privilegiato per insegnare, formare ed ispirare un pubblico sempre più ampio. Ma non si parla solo di trasmissione uni-direzionale: il dibattito fra scienza, tecnologia e società (amministratori locali, politici, imprenditori, giornalisti, studenti e semplici cittadini) sta guadagnando una partecipazione di interlocutori sempre più numerosi e preparati su temi dalle complesse caratteristiche ed implicazioni (etiche, sociali, economiche, politiche). Questo è in parte dovuto ai cambiamenti avvenuti negli ultimi anni nella scienza (e all’impatto che essa sta avendo in molti ambiti della vita sociale. Tali cambiamenti stanno determinando nuove forme di comunicazione scientifica e cooperazione con la società e l’aumento, nell’ultimo decennio, di iniziative e percorsi di formazione, spesso organizzati dalle stesse istituzioni scientifiche. Uno dei risultati più tangibili della cambiata interazione fra scienza e società è la nuova generazione di ricercatori-comunicatori, dotati di una maggiore abilità nel comunicare la scienza in modo efficace e ad un pubblico più ampio e diversificato. In questo contesto diventa importante capire l’efficacia di ogni azione di comunicazione scientifica, impostando uno studio che analizzi, volta per volta, i punti di successo e le criticità emerse nei due comparti causa-effetto. Causa – gli elementi di base della comunicazione scientifica e tecnologica:  i valori sociali e culturali di riferimento (ad es. protezione ambientale, sicurezza, salute); - i contenuti (formato di presentazione, tematiche scelte); - i canali usati (web, social networks, stampa cartacea etc.); - i modelli di relazione con il pubblico (scienza vs pubblico, peer education). Effetto - la risposta della società:  diretta (affluenza; questionari di gradimento)  indiretta (visualizzazioni web; like se tweet dei social network). Questo lavoro presenta una relazione illustrativa (per la prima volta sul territorio della Spezia) dell’efficacia di un evento specifico inserito all’interno di una manifestazione di portata locale, la “Festa della Marineria 2013 ”, destinato al grande pubblico e caratterizzato da diverse attività (tra le quali quelle di tipo ludico-educativo) concepite con l’obiettivo di puntare l’attenzione sui ‘tesori’ scientifici e culturali di una ‘Città di Mare’qual'è La Spezia

The SUCCESSO-TERRA project: A lesson of sustainability from the terramare culture, middle bronze age of the po plain (Northern Italy)

This backstory article deals with the SUCCESSO-TERRA Project (2017–2020), an interdisciplinary research program aiming at reconstructing the land-use transformations that occurred during the development of the Terramare culture in the southern-central Po Plain of Northern Italy. Topics include climate-environment changes, human impact and exploitation of natural resources that are interconnected topics in human ecology and environmental sciences. These topics can only be understood in a long-term perspective integrating archaeology, geology, botany and other sciences. The text includes the theoretical basis, the research strategy and the main methodological approaches given by geoarchaeology and palynology, the two research sides constituting the partnership of the project

Integrating discrete- and continuous-time metric temporal logics through sampling

Abstract. Real-time systems usually encompass parts that are best described by a continuous-time model, such as physical processes under control, together with other components that are more naturally formalized by a discrete-time model, such as digital computing modules. Describing such systems in a unified framework based on metric temporal logic requires to integrate formulas which are interpreted over discrete and continuous time. In this paper, we tackle this problem with reference to the metric temporal logic TRIO, that admits both a discrete-time and a continuous-time semantics. We identify sufficient conditions under which TRIO formulas have a consistent truth value when moving from continuous-time to discrete-time interpretations, or vice versa. These conditions basically involve the restriction to a proper subset of the TRIO language and a requirement on the finite variability over time of the basic items in the specification formulas. We demonstrate the approach with an example of specification and verification

A timeband framework for modelling real-time systems

Complex real-time systems must integrate physical processes with digital control, human operation and organisational structures. New scientific foundations are required for specifying, designing and implementing these systems. One key challenge is to cope with the wide range of time scales and dynamics inherent in such systems. To exploit the unique properties of time, with the aim of producing more dependable computer-based systems, it is desirable to explicitly identify distinct time bands in which the system is situated. Such a framework enables the temporal properties and associated dynamic behaviour of existing systems to be described and the requirements for new or modified systems to be specified. A system model based on a finite set of distinct time bands is motivated and developed in this paper