Archivio Istituzionale della Ricerca- Università del Salento
Not a member yet
80217 research outputs found
Sort by
On Surfaces of Exceptional Lorentzian Lie Groups with a Four-Dimensional Isometry Group
No full textIn total, geodesic surfaces and their generalizations, namely totally umbilical and parallel surfaces, are well-known topics in Submanifold Theory and have been intensively studied in three-dimensional ambient spaces, both Riemannian and Lorentzian. In this paper, we prove the non-existence of parallel and totally umbilical (in particular, totally geodesic) surfaces for three-dimensional Lorentzian Lie groups, which admit a four-dimensional isometry group, but are neither of Bianchi–Cartan–Vranceanu-type nor homogeneous plane waves. Consequently, the results of the present paper complete the investigation of these fundamental types of surfaces in all homogeneous Lorentzian manifolds, whose isometry group is four-dimensional. As a byproduct, we describe a large class of flat surfaces of constant mean curvature in these ambient spaces and exhibit a family of examples
Combined use of web scraping and AI-based models for business applications: research evolution and future trends
No full textSearch for boosted low-mass resonances decaying into hadrons produced in association with a photon in pp collisions at sqrt(s) = 13 TeV with the ATLAS detector
No full textMany extensions of the Standard Model, including those with dark matter particles, propose new mediator particles that decay into hadrons. This paper presents a search for such low mass narrow resonances decaying into hadrons using 140 fb-1 of proton-proton collision data recorded with the ATLAS detector at a centre-of-mass energy of 13 TeV. The resonances are searched for in the invariant mass spectrum of large-radius jets with two-pronged substructure that are recoiling against an energetic photon from initial state radiation, which is used as a trigger to circumvent limitations on the maximum data recording rate. This technique enables the search for boosted hadronically decaying resonances in the mass range 20–100 GeV hitherto unprobed by the ATLAS Collaboration. The observed data are found to agree with Standard Model predictions and 95% confidence level upper limits are set on the coupling of a hypothetical new spin-1 Z′ resonance with Standard Model quarks as a function of the assumed Z′-boson mass in the range between 20 GeV and 200 GeV
Multimodality and second language phonetic learning: preliminary evidence from two experimental studies
No full textLanguage learning is inherently multimodal, combining auditory, visual, and textual inputs that reflect the complexity of natural language
and communication. Multimodality can also promote second language (L2)
acquisition by enhancing perceptual and productive language skills. This
study explores how multimodal inputs support Salentino Italian (L1) speakers
in perceiving and producing Southern Standard British English (L2) vowels /e/, /æ/, /6/, and /2/. In Experiment 1, we compared audiovisual and
audio-only High Variability Phonetic Training (HVPT). Audiovisual input
temporarily improved perception of visually salient sounds but failed to stabilize auditory representations. Experiment 2 examined vowel production after
exposure to TV series clips with L2 (English), L1 (Italian), or no subtitles.
L2 subtitles improved /æ/ production, demonstrating the value of textual
input in linking visual, phonetic, and orthographic information. However,
the L2 vowel /2/ showed limited improvement, suggesting multimodality’s
effectiveness depends on the phonetic salience and relevance of features
within the L1 system. These findings highlight multimodality’s potential to
enhance L2 learning while underscoring how L1 phonological traits shape
its impact
Space-time blind source separation and linear coregionalization modeling: a critical comparison
No full textIn many fields of science, multivariate spatio-temporal data can exhibit quite complex dependence structures between the variables and over the domain. Many approaches exist to model such data and usually their starting point is the matrix-valued covariance function (CF). The well-established space-time linear coregionalization model (ST-LCM) and more recently the space-time blind source separation-based model (ST-BSS) can easily support the modeling stage, since they rely on the univariate analysis of latent components. Although they have been developed within distinct backgrounds and some differences between them can be highlighted, they also share various similarities from a theoretical and practical point of view. A critical review of the hypothesis, properties and characteristics of the two approaches is then proposed and a comparison of their performances is provided through a real dataset analysis and a simulation study
Walking patterns and cognitive performance in Tai Chi experts: Exploring the connection to motor control
No full textPurpose. Tai Chi is an ancient Chinese martial art known for its physical and mental health benefits. This study explores the potential of Tai Chi to improve motor abilities and cognitive functions, with particular attention to the integration between movement and executive control processes. Given its emphasis on controlled, deliberate movements coordinated with attention and breath, Tai Chi may foster a deeper awareness of body mechanics and enhance neurocognitive functioning. Methods. We enrolled a group of individuals who regularly practiced Tai Chi and a control group of healthy individuals with no prior Tai Chi experience or involvement in comparable mind-body practices. Gait was assessed using the harmonic ratio, a widely recognized measure of movement smoothness, stability, and motor control ability derived from trunk acceleration during walking. Participants’ cognitive condition was evaluated using a battery of standardized assessments targeting domains such as executive functioning, attention, and working memory, alongside self-report measures capturing perceived cognitive performance and daily functioning. Results. The results revealed lower harmonic ratio values (i.e., higher motor control) in Tai Chi practitioners compared to the healthy controls. The enhanced motor ability observed in the Tai Chi group may be attributed to the attentional focus operated on movement through the practice, which promotes enhanced cognitive-motor integration. These findings suggest that Tai Chi may lead to measurable changes in neuromuscular coordination. Conclusions. Furthermore, the study demonstrated a positive correlation between harmonic ratio values and executive functions’ scores in the Tai Chi group, supporting the hypothesis that regular Tai Chi practice contributes to improved cognitive efficiency and sensorimotor performanc
Il linguaggio identitario della Sacra Corona Unita, un codice salentino nel panorama delle mafie tradizionali
No full textL’intervento intende tracciare gli elementi linguistici d’originalità della comunicazione della Sacra Corona Unita, organizzazione mafiosa sviluppatasi a Mesagne (BR), fino ad assorbire le province di Brindisi, Lecce e Taranto. La nascita della SCU, nel 1983, rappresenta un fenomeno antropologico e socio-culturale senza precedenti: camorra, ’ndrangheta e Cosa nostra entrano a contatto, linguisticamente e affaristicamente. Oggetto dell’analisi è il linguaggio come forma identitaria della consorteria: i simboli (icone religiose e tatuaggi); le gerarchie (gradi e cariche); i codici (le regole per il buon mafioso); il lessico delle pene (per le punizioni); l’antilingua funzionale alla circolazione dei messaggi; l’onomastica (i soprannomi di celebri capibastone e capizona); la toponomastica (luoghi entrati nell’immaginario collettivo). Un approfondimento, infine, è riservato al giuramento d’affiliazione, nel quale ritroviamo riferimenti dotti all’Inferno dantesco e al Risorgimento italiano
Oggetti di ornamento personale. Le fibule
No full textIl contributo passa in rassegna le fibule rinvenute probabilmente nel deposito votivo di Cascia, Valle Fuino, sulla base della documentazione d'archivio
Time-Based EIS Approach for State-of-Charge Assessment of Li-Ion Battery Cells in Automotive Applications: A Simulation Study
No full textThis paper presents a simulation-based study on a time-domain electrochemical impedance spectroscopy (EIS) approach for the state-of-charge (SoC) assessment of lithiumion battery (LIB) cells in automotive applications. The proposed methodology is validated within a MATLAB simulation environment by implementing an equivalent circuit model and analyzing impulse response (IR) measurements under varying SoC and temperature conditions. The IR obtained from the simulated measurement system is compared against the ideal battery's equivalent circuit model, demonstrating a strong correlation. Despite lower accuracy at elevated temperatures, the approach remains effective in SoC estimation. To further validate its robustness, a narrow neural network (NN) model is trained on temperature-dependent IRs, achieving reliable SoC classification. These results confirm the feasibility of the proposed method for real-time battery monitoring, offering a potential alternative to conventional frequency-domain EIS techniques