Search results for "LSA"
showing 10 items of 832 documents
Orbital Evolution of an Accreting Millisecond Pulsar: Witnessing the Banquet of a Hidden Black Widow?
2007
We have performed a timing analysis of all the four X-ray outbursts from the accreting millisecond pulsar SAX J1808.4-3658 observed so far by the PCA on board RXTE. For each of the outbursts we derived the best-fit value of the time of ascending node passage. We find that these times follow a parabolic trend, which gives an orbital period derivative $\dot P_{\rm orb} = (3.40 \pm 0.18) \times 10^{-12}$ s/s, and a refined estimate of the orbital period, $P_{\rm orb} = 7249.156499 \pm 1.8 \times 10^{-5}$ s (reference epoch $T_0 = 50914.8099$ MJD). This derivative is positive, suggesting a degenerate or fully convective companion star, but is more than one order of magnitude higher than what is…
X-ray bursts and burst oscillations from the slowly spinning X-ray pulsar IGR J17480-2446 (Terzan 5)
2011
The newly discovered 11-Hz accreting pulsar, IGR J17480-2446, located in the globular cluster Terzan 5, has shown several bursts with a recurrence time as short as a few minutes. The source shows the shortest recurrence time ever observed from a neutron star. Here we present a study of the morphological, spectral and temporal properties of 107 bursts observed by the Rossi X-ray Timing Explorer. The recurrence time and the fluence of the bursts clearly anticorrelate with the increase in the persistent X-ray flux. The ratio between the energy generated by the accretion of mass and that liberated during bursts indicates that helium is ignited in a hydrogen-rich layer. Therefore, we conclude th…
Emo-dramatic Robotic Stewards
2010
In this paper will be presented an heterogeneous colony of robots capable to cooperate with people as effective partners to provide different kind of support among various working environments, such as museums, offices or trade fairs. Many systems have been integrated in order to develop robots capable to assists humans during the visit of the site, to guide them and to give information about the environment. According to the drama’s theory, each robot has a different character, something like a personality, so, each of them will interact with people in a different way. Robots show also emotional, non trivial, behaviours using an LSA conceptual space capable to synthesize the different emot…
TSVD as a Statistical Estimator in the Latent Semantic Analysis Paradigm
2015
The aim of this paper is to present a new point of view that makes it possible to give a statistical interpretation of the traditional latent semantic analysis (LSA) paradigm based on the truncated singular value decomposition (TSVD) technique. We show how the TSVD can be interpreted as a statistical estimator derived from the LSA co-occurrence relationship matrix by mapping probability distributions on Riemanian manifolds. Besides, the quality of the estimator model can be expressed by introducing a figure of merit arising from the Solomonoff approach. This figure of merit takes into account both the adherence to the sample data and the simplicity of the model. In our model, the simplicity…
A combined semantic-syntactic sentence analysis for students assessment
2010
TutorJ is an Intelligent Tutoring System able to fulfill the requests of a student with a learning path inside didactical materials. To this aim, it must assess the level of training of the learner. In the first version of TutorJ this goal was reached through a conversational agent whose linguistic interaction enriched by a LSA-based text analysis. This approach suffers from the limitations of LSA as a bag-of- words approach. Next, morphosyntactic comparison of sentences' structures was implemented. In this paper we present a new version of the assessment procedure involving both semantic, and morphosyntactic analysis user's sentences.
Sentence Induced Transformations in Conceptual Spaces
2008
The proposed work illustrates how "primitive concepts" can be automatically induced from a text corpus. The primitive concepts are identified by the orthonormal axis of a "conceptual" space induced by a methodology inspired to the latent semantic analysis approach. The methodology represents a natural language sentence by means of a set of rotations of an orthonormal basis in the "conceptual"space. The rotations, triggered by the sequence of words composing the sentence and realized by means of geometric algebra rotors, allow to highlight "conceptual" relations that can arise among the primitive concepts.
Licenziamento disciplinare per falsa attestazione di presenza in servizio: prevalenza della legge sulla contrattazione collettiva e margini valutati …
2019
Il saggio analizza la fattispecie della falsa attestazione in servizio e la rilevanza del principio di proporzionalità nel procedimento disciplinare
La vita e le strane sorprendenti avventure di Arturo. Per un confronto con Robinson Crusoe
2020
he life and strange surprising adventures of Arturo. Cues for a comparison with Robinson Crusoe · The article displays a comparative reading between L’isola di Arturo and Defoe’s Robinson Crusoe, inspired by a statement made by Elsa Morante in a 1957 interview after the awarding of the ‘Strega’ prize. In the first place, the press coverage of the novel is studied with particular attention to confrontations with Robinson. Secondly, I aim to trace the steps of the possibility that Morante actually took into account Defoe’s novel. Afterward, a short, comparative study concerning a possible impact of Robinson on Arturo is proposed. The confrontation goes through several issues: narrative patter…
Al-Ġazālī ed Ibn Taymiyya: la questione dei pii antenati
2019
Abstract The purpose of this article is to read, under a different light, the relationship between al-Ġazālī and Ibn Taymiyya thanks to the analysis of their writings (from Iḥyāʾ ʿulūm al-dīn to Ilǧām al-ʿawāmm ʿan ʿilm al-kalām) in order to find commonalities and differences in the ideological proposal of the two authors. In line with Michot, Hoover, Anjum and Rapoport, this article includes Ibn Taymiyya in the ideological debate of the Islamic thought and provides evidences in order to not consider him only as the forefather of radicalism and fundamentalism, but rather a complex and sophisticated jurist, theologue, thinker. A man of his time. This aim is reached by investigating the conce…
Effetti della Terapia con Sacubitril/Valsartan sulla Capacità di Esercizio dei pazienti con Scompenso Cardiaco a Frazione di Eiezione Ridotta (HFrEF)…
2021
Introduzione: La terapia con Sacubitril/Valsartan nei pazienti con scompenso cardiaco a frazione di eiezione ridotta (HFrEF) si è dimostrata superiore alla singola terapia con Enalapril nella riduzione del rischio di morte ed ospedalizzazione per scompenso cardiaco. Obiettivo del presente studio è stato quello di valutare, nei pazienti con HFrEF, gli effetti della terapia con sacubitril/valsartan sulla capacità di esercizio valutata mediante Test Cardiorespiratorio e l’eventuale correlazione con il grado di fibrosi miocardica valutata mediante Risonanza Magnetica Cardiaca (CMR). Metodi: E’ stato condotto uno studio osservazionale, prospettico. 134 pazienti ambulatoriali con HFrEF sono stati…