16 research outputs found

    Interval Temporal Random Forests with an Application to COVID-19 Diagnosis

    Get PDF
    Symbolic learning is the logic-based approach to machine learning. The mission of symbolic learning is to provide algorithms and methodologies to extract logical information from data and express it in an interpretable way. In the context of temporal data, interval temporal logic has been recently proposed as a suitable tool for symbolic learning, specifically via the design of an interval temporal logic decision tree extraction algorithm. Building on it, we study here its natural generalization to interval temporal random forests, mimicking the corresponding schema at the propositional level. Interval temporal random forests turn out to be a very performing multivariate time series classification method, which, despite the introduction of a functional component, are still logically interpretable to some extent. We apply this method to the problem of diagnosing COVID-19 based on the time series that emerge from cough and breath recording of positive versus negative subjects. Our experiment show that our models achieve very high accuracies and sensitivities, often superior to those achieved by classical methods on the same data. Although other recent approaches to the same problem (based on different and more numerous data) show even better statistical results, our solution is the first logic-based, interpretable, and explainable one

    Il ruolo della Corte di giustizia nella definizione della politica economica e monetaria europea

    Get PDF
    Il ruolo giocato dalla Corte di giustizia nel campo della politica economica e della politica monetaria è stato importante quanto sottostimato. Le due competenze dell’Unione sono profondamente differenti - ciascuna dotata di significative peculiarità - e tuttavia strettamente interconnesse. Definire i confini incerti tra politica economica e politica monetaria è stato il ruolo più importante svolto dalla Corte in questo campo. Questo ha comportato una precisazione dei ruoli delle istituzioni chiamate ad agire - Commissione, Consiglio, Banca centrale - così come dei limiti all’indipendenza dell’istituto di emissione, ma anche della ripartizione di competenze tra Stati e Unione. Dal 2012, un’ulteriore funzione è stata esercitata dalla Corte: la verifica della legittimità dell’intervento straordinario della BCE nell’economia per gestire le crisi. L’assenza nei trattati europei di disposizioni specifiche che contemplassero un ruolo della Banca come prestatore di ultima istanza o nella gestione delle crisi economiche e finanziarie spiega bene le contestazioni dell’ultimo decennio, così come la necessità di pronunce autorevoli da parte della Suprema Corte europea. Queste si collocano a buon diritto nel solco della giurisprudenza in tema di rule of law e di garanzia del rispetto dei principi generali nell’ordinamento europeo

    Statistical and Symbolic Neuroaesthetics Rules Extraction From EEG Signals

    No full text
    Neuroaesthetics, as defined by Zeki in 1999, is the scientific approach to the study of aesthetic perceptions of art, music, or any other experience that can give rise to aesthetic judgments. One way to understand the processes of neuroaesthetics is studying the electroencephalogram (EEG) signals that are recorded from subjects while they are exposed to some expression of art, and study how the differences among such signals correlate to the differences in their subjective judgments; typically, such studies are conducted on limited data with a purely statistical signal analysis. In this paper we consider a larger data set which was previously used in an experiment on beauty perception; we apply a novel machine learning-based data analysis methodology that allows us to extract symbolic like/dislike rules on the voltage at the most relevant frequencies from the most relevant electrodes. Our approach is not only novel in this particular area, but it is also reproducible and allows us to treat large quantities of data

    A narrative of historical, methodological, and technological observations in marine science

    No full text
    Over the years, tools and methods to measure ocean characteristics have evolved with some of the early instruments being rather curious-looking while others have anticipated the current approaches to observations. Information contained in historical books from the 17th to the beginning of the 20th century, from Boyle and Hooke to Nansen and Ekman, demonstrate the evolution of instruments and methods used to investigate the marine environment. This chapter offers a summary of the changes in technologies and methods for the measurements of ocean depth, temperature, salinity, sea water gravity, and zoological observations. It also presents examples of historical data collected in the Arctic compared with present observations in this geographic region. The chapter provides a general view of the rapid evolution in methods and technology resulting in new observational procedures

    Numerical analysis of the rheological behaviour of the Socompa debris avalanche, Chile

    No full text
    Socompa Volcano provides one of the world’s best-exposed example of a sector collapse that generated debris avalanche deposit. The debris avalanche, occurred about 7000 years ago, involved 25 km3 of fragmented rock that formed a thin but widespread (500 km2) deposit. Numerical model of this event was already performed using a shock-capturing method based on double upwind Eulerian scheme in order to provide information for investigating, within realistic geological context, its dynamic and run-out (Kelfoun and Druitt 2005). This paper analyses an important aspect of the continuum numerical modeling of rapid landslides as debris avalanche: the interchangeability of rheological parameter values. The main question is: by using the same rheological parameter values, are the results, obtained with codes that implement the same constitutive equations but different numerical solvers, equal? Answering this question has required to compare the previous back analysis results with new numerical analyses performed using RASH3D code. Different rheological laws were selected and calibrated in order to identify the law that better fits the characteristics of the final debris deposit of the Socompa landslide

    Insulin resistance is an independent risk factor for atherosclerosis in rheumatoid arthritis

    No full text
    The objective of this study was to investigate the relationship between insulin resistance (IR) and subclinical atherosclerosis in patients with rheumatoid arthritis (RA). Carotid artery intima media thickness (IMT), using ultrasound evaluation, and other clinical and laboratory variables were investigated in 45 RA outpatients and in 48 controls with soft tissue disorders. IR was assayed by homeostasis model assessment (HOMA2) and metabolic syndrome by National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) criteria. Insulin resistance, as defined by HOMA2-IR>1, was seen in 40 (88.9%) RA patients and in three (6.2%) controls (p<0.001). No significant difference was detected in the prevalence of metabolic syndrome. The median IMT was greater in RA patients (0.76 mm; interquartile range [IQR] 0.65, 0.85) than in the controls (0.66 mm; IQR 0.60, 0.72) (p<0.001). Dividing the RA patients according to the cut-off IMT value (0.72 mm), a difference was detected in both systolic (p=0.04) and diastolic blood pressure (p=0.02), disease activity score (DAS28) (p=0.008), HOMA2-IR (p<0.001) and cumulative oral steroid dose (p=0.001). Moreover, the frequency of cases with increased IMT was higher in glucocorticoid users than in non-users (21/23 vs. 9/22, respectively) (p<0.001). Spearman's rho correlation showed a significant positive relationship between IMT and HOMA2-IR (p<0.001). Multivariate stepwise analysis selected HOMA2-IR plus diastolic BP plus glucocorticoid exposure as the best predictive model for subclinical atherosclerosis (R2c=0.577, F=21, p<0.001). In conclusion, this study showed a significantly higher prevalence of IR in RA patients and pointed out a significant association between IR and subclinical atherosclerosis. This relationship may be driven primarily by exposure to steroid therapy

    Measuring the sea: Marsili's Oceanographic Cruise (1679-80) and the roots of oceanography

    No full text
    The first in situ measurements of seawater density that referred to a geographical position at sea and time of the year were carried out by Count Luigi Ferdinando Marsili between 1679 and 1680 in the Adriatic Sea, Aegean Sea, Marmara Sea, and the Bosporus. Not only was this the first investigation with documented oceanographic measurements carried out at stations, but the measurements were described in such an accurate way that the authors were able to reconstruct the observations in modern units. These first measurements concern the \u201cspecific gravity\u201d of seawaters (i.e., the ratio between fluid densities). The data reported in the historical oceanographic treatise Osservazioni intorno al Bosforo Tracio (Marsili) allowed the reconstruction of the seawater density at different geographic locations between 1679 and 1680. Marsili\u2019s experimental methodology included the collection of surface and deep water samples, the analysis of the samples with a hydrostatic ampoule, and the use of a reference water to standardize the measurements. A comparison of reconstructed densities with present-day values shows an agreement within 10%\u201320% uncertainty, owing to various aspects of the measurement methodology that are difficult to reconstruct from the documentary evidence. Marsili also measured the current speed and the depth of the current inversion in the Bosporus, which are consistent with the present-day knowledge. The experimental data collected in the Bosporus enabled Marsili to enunciate a theory on the cause of the two-layer flow at the strait, demonstrated by his laboratory experiment and later confirmed by many analytical and numerical studies

    Measuring the Sea: Marsili’s Oceanographic Cruise (1679–80) and the Roots of Oceanography

    No full text
    The first in situ measurements of seawater density that referred to a geographical position at sea and time of the year were carried out by Count Luigi Ferdinando Marsili between 1679 and 1680 in the Adriatic Sea, Aegean Sea, Marmara Sea, and the Bosporus. Not only was this the first investigation with documented oceanographic measurements carried out at stations, but themeasurements were described in such an accurateway that the authorswere able to reconstruct the observations in modern units. These first measurements concern the ‘‘specific gravity’’ of seawaters (i.e., the ratio between fluid densities). The data reported in the historical oceanographic treatise Osservazioni intorno al Bosforo Tracio (Marsili) allowed the reconstruction of the seawater density at different geographic locations between 1679 and 1680. Marsili’s experimental methodology included the collection of surface and deep water samples, the analysis of the samples with a hydrostatic ampoule, and the use of a reference water to standardize the measurements.Acomparison of reconstructed densities with present-day values shows an agreement within 10%–20% uncertainty, owing to various aspects of the measurement methodology that are difficult to reconstruct from the documentary evidence. Marsili also measured the current speed and the depth of the current inversion in the Bosporus, which are consistent with the present-day knowledge. The experimental data collected in the Bosporus enabledMarsili to enunciate a theory on the cause of the two-layer flow at the strait, demonstrated by his laboratory experiment and later confirmed by many analytical and numerical studies.American Meteorological Society.Published845 - 8604A. Oceanografia e climaJCR Journa
    corecore