4,204 research outputs found
On-line speaker diarization for smart objects
No full textLa diarisation du locuteur en temps réel vise à détecter "qui parle maintenant" dans un flux audio donné. La majorité des systèmes de diarisation en ligne proposés a mis l'accent sur des domaines moins difficiles, tels que l’émission des nouvelles et discours en plénière, caractérisé par une faible spontanéité. La première contribution de cette thèse est le développement d'un système de diarisation du locuteur complètement un-supervisé et adaptatif en ligne pour les données de réunions qui sont plus difficiles et spontanées. En raison des hauts taux d’erreur de diarisation, une approche semi-supervisé pour la diarisation en ligne, ou les modèles des interlocuteurs sont initialisés avec une quantité modeste de données étiquetées manuellement et adaptées par une incrémentale maximum a-posteriori adaptation (MAP) procédure, est proposée. Les erreurs obtenues peuvent être suffisamment bas pour supporter des applications pratiques. La deuxième partie de la thèse aborde le problème de la normalisation phonétique pendant la modélisation des interlocuteurs avec petites quantités des données. Tout d'abord, Phone Adaptive Training (PAT), une technique récemment proposé, est évalué et optimisé au niveau de la modélisation des interlocuteurs et dans le cadre de la vérification automatique du locuteur (ASV) et est ensuite développée vers un système entièrement un-supervise en utilisant des transcriptions de classe acoustiques générées automatiquement, dont le nombre est contrôlé par analyse de l'arbre de régression. PAT offre des améliorations significatives dans la performance d'un système ASV iVector, même lorsque des transcriptions phonétiques précises ne sont pas disponibles.On-line speaker diarization aims to detect “who is speaking now" in a given audio stream. The majority of proposed on-line speaker diarization systems has focused on less challenging domains, such as broadcast news and plenary speeches, characterised by long speaker turns and low spontaneity. The first contribution of this thesis is the development of a completely unsupervised adaptive on-line diarization system for challenging and highly spontaneous meeting data. Due to the obtained high diarization error rates, a semi-supervised approach to on-line diarization, whereby speaker models are seeded with a modest amount of manually labelled data and adapted by an efficient incremental maximum a-posteriori adaptation (MAP) procedure, is proposed. Obtained error rates may be low enough to support practical applications. The second part of the thesis addresses instead the problem of phone normalisation when dealing with short-duration speaker modelling. First, Phone Adaptive Training (PAT), a recently proposed technique, is assessed and optimised at the speaker modelling level and in the context of automatic speaker verification (ASV) and then is further developed towards a completely unsupervised system using automatically generated acoustic class transcriptions, whose number is controlled by regression tree analysis. PAT delivers significant improvements in the performance of a state-of-the-art iVector ASV system even when accurate phonetic transcriptions are not available
VOLTAMMETRIC DETERMINATION OF SOME ORGANIC COMPOUNDS OF ARSENIC REDUCED AT THE MERCURY ELECTRODE
No full textCyclic voltammetric scans for methylarsonic acid, dimethylarsinic acid and 3-acetamido-4-hydroxyphenylarsonic acid at amercuryelectrode in an acidic medium show anodic adsorption waves when the starting potential is sufficiently negative; the related arsines are formed on the electrode. Detection limits are at the micromolar level for the absorption peak found at about −0.1 V vs. SCE for all three compounds. Interferences are discussed
Le «buone letture». 2. Giovanni Casati
No full textIl saggio è costituito da due parti, la prima delle quali, dedicata alla fondazione della Federazione italiana delle biblioteche circolanti cattoliche, è stata pubblicata nel precedente numero dei «Nuovi Annali», XXVII (2013), pp. 137-163. In questa seconda parte viene delineata la figura intellettuale di Giovanni Casati, che diresse la «Rivista di letture» dal 1912 al 1944, trasformando il periodico della Federazione in una rivista impegnata nella divulgazione della cultura cattolica. A questo impegno militante Casati fece corrispondere un intenso programma editoriale, che trovò espressione nella pubblicazione di saggi letterari, di manuali e opere repertoriali.The study consists of two parts; the first is dedicated to the history of the Federazione italiana delle biblioteche circolanti cattoliche since its foundation (1904) up to 1912 and was published in the previous volume of the «Nuovi Annali », XXVII (2013), pp. 137-163. In this second part, the author outlines the intellectual figure of Giovanni Casati, who directed the «Rivista di letture» from 1912 to 1944, transforming the magazine of the Federation in a journal engaged in the spreading of Catholic culture. To this militant engagement Casati matched an intense publishing program, which found its expression in the publication of literary essays, manuals and reference works
Comico e tragico del diritto nella novellistica italiana: il novelliere di Giovanni Sercambi
No full textNelle novelle di età tardomedievale ed umanistica, a causa del loro carattere fortemente realistico, il diritto ha un posto importante, poiché rappresenta un elemento centrale e ineliminabile della vita della comunità. Il novelliere di Giovanni Sercambi da Lucca non fa eccezione, anche se l’autore non ha una cultura giuridica né s’interessa in modo specifico al diritto. Il presente saggio vuole analizzare sotto tale profilo queste novelle per verificare quale concezione del diritto emerge da esse e come la narrazione ne risulti arricchita.In the late medieval and humanistic novellas, owing to their very realistic character, the right is an important central and inevitable element in community life. Giovanni Sercambi’s novelliere is no exception even if the author lacks a legal culture, nor is specifically interested in right. This essay intends to analyze these novellas under this profile to verify what kind of right they consider and how the stories are enriched
Characterization of the resistance to the anorectic and endocrine effects of leptin in obesity-prone and obesity-resistant rats fed a high fat diet
No full textLeptin produced by adipocytes controls body weight by
restraining food intake and enhancing energy expenditure
at the hypothalamic level. The diet-induced increase in fat
mass is associated with the presence of elevated circulating
leptin levels, suggesting the development of resistance to
its anorectic effect. Rats, like humans, show different
susceptibility to diet-induced obesity. The aim of the
present study was to compare the degree of leptin resistance
in obesity-prone (OP) vs obesity-resistant (OR) rats
on a moderate high-fat (HF) diet and to establish if the
effects of leptin on hypothalamo–pituitary endocrine functions
were preserved. Starting from 6 weeks after birth,
male Sprague–Dawley rats were fed on either a commercial
HF diet (fat content: 20% of total calorie intake) or a
standard pellet chow (CONT diet, fat content: 3%). After
12 weeks of diet, rats fed on HF diet were significantly
heavier than rats fed on CONT diet. Animals fed on HF
diet were ranked according to body weight; the two tails
of the distribution were called OP and OR rats respectively.
A polyethylene cannula was implanted into the
right ventricle of rats 1 week before central leptin administration.
After 12 weeks of HF feeding, both OR and OP
rats were resistant to central leptin administration (10 μg,
i.c.v.) (24 h calorie intake as a percent of vehicle-treated
rats: CONT rats, 62 [50; 78]; OR, 93 [66; 118]; OP, 90
[70; 120] as medians and 95% confidence intervals (CIs) of
six rats for each group). Conversely, after 32 weeks of diet
both OR and OP rats were partially responsive to 10 μg
leptin i.c.v. as compared with CONT rats (24 h calorie
intake as a percent of vehicle-treated rats: CONT rats, 60
[50; 67]; OR, 65 [50; 80]; OP, 80 [60; 98] as medians and
95% CIs of six rats for each group); the decrease of food
intake following 200 μg leptin i.p. administration was
similar in all the three groups (calorie intake as a percent of
vehicle-treated rats: 86 [80; 92] as median and 95% CI).
The long-term intake of HF diet caused hyperleptinemia,
hyperinsulinemia and higher plasma glucose levels in OP
rats as compared with CONT rats. Plasma thyroxine (T4)
was lower in all the rats fed the HF diet as compared with
CONT. i.c.v. administration of leptin after 32 weeks of
diet restored normal insulin levels in OP rats. Moreover,
leptin increased plasma T4 concentration and strongly
enhanced GH mRNA expression in the pituitary of OP as
well as OR rats (18010% vs vehicle-treated rats). In
conclusion, long-term intake of HF diet induced a partial
central resistance to the anorectic effect of leptin in both
lean and fat animals; the neuroendocrine effects of leptin
on T4 and GH were preserved
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