University of Udine
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Energy-efficient motion planning for robotic systems using polynomials in the Chebyshev basis
No full textMotion profile optimization is a powerful technique for enhancing the efficiency of robotic systems without necessitating hardware modifications. Nonetheless, the prevailing usage of piecewise or polynomial position functions can often require a high number of design parameters or result in unbounded optimization problems. This paper presents a novel approach employing polynomials expressed in the Chebyshev basis for the position function of multi-degree-of-freedom (DOF) systems, enabling substantial performance improvements with a minimal number of design parameters while enabling the use of a bounded design space. More specifically, this work focuses on reducing energy consumption while maintaining a fixed motion time. Moreover, by symbolically formulating the motion profile, it is demonstrated that kinematic constraints can be linearized, leading to accelerated convergence in the optimization process. To illustrate the robustness of the proposed method under different operational conditions, optimizations were executed on three distinct motion tasks and a range of payload values, and compared to a state-of-the-art method. Experimental results strongly validate the effectiveness of the proposed approach, demonstrating a reduction in root mean square (rms) torque by up to-47.6% with a limited number of design parameters for each joint
Innovative Multi-Stage Power Conversion Architecture with Enhanced Transient Response for Data Center Applications.
No full textGRB 221009A: Observations with LST-1 of CTAO and Implications for Structured Jets in Long Gamma-Ray Bursts
Get PDFGRB 221009A is the brightest gamma-ray burst (GRB) observed to date. Extensive observations of its afterglow emission across the electromagnetic spectrum were performed, providing the first strong evidence of a jet with a nontrivial angular structure in a long GRB. We carried out an extensive observation campaign in very-high-energy (VHE) gamma rays with the first Large-Sized Telescope of the future Cherenkov Telescope Array Observatory starting on 2022 October 10, about 1 day after the burst. A dedicated analysis of the GRB 221009A data is performed to account for the different moonlight conditions under which data were recorded. We find an excess of gamma-like events with a statistical significance of 4.1σ during the observations taken 1.33 days after the burst, followed by background-compatible results for the later days. The results are compared with various models of afterglows from structured jets that are consistent with the published multiwavelength data but entail significant quantitative and qualitative differences in the VHE emission after 1 day. We disfavor models that imply VHE flux at 1 day considerably above 10−11 erg cm−2 s−1. Our late-time VHE observations can help disentangle the degeneracy among the models and provide valuable new insight into the structure of GRB jets
The molecular landscape of hereditary ataxia: a single-center study
Get PDFHereditary ataxia (HA) is a heterogeneous group of complex neurological disorders, which represent a diagnostic challenge due to their diverse phenotypes and genetic etiologies. Next-generation sequencing (NGS) has revolutionized the field of neurogenetics, improving the identification of ataxia-associated genes. Notwithstanding, repeat expansions analysis remains a cornerstone in the diagnostic workflow of these diseases. Here we describe the molecular characterization of a consecutive single-center series of 70 patients with genetically uncharacterized HA. Patients’ samples were analyzed for known HA-associated repeat expansions as first tier and negative ones were analyzed by whole exome sequencing (WES) as second tier. Overall, we identified pathogenic/likely pathogenic variants in 40% (n = 28/70) and variants of unknown significance (VUS) in 20% (n = 14/70) of cases. In particular, 10 patients (14.3%, n = 10/70) presented pathogenic repeat expansions while 18 cases (30%, n = 18/60) harbored at least a single nucleotide variant (SNV) or a copy number variant (CNV) in HA or HSP-related genes. WES allowed assessing complex neurological diseases (i.e., leukodystrophies, cerebrotendinous xanthomatosis and atypical xeroderma pigmentosum), which are not usually referred as pure genetic ataxias. Our data suggests that the combined use of repeat expansion analysis and WES, coupled to detailed clinical phenotyping, is able to detect the molecular alteration underpinning ataxia in almost 50% cases, regardless of the hereditary pattern. Indeed, NGS-based tests are fundamental to acknowledge novel HA-associated genes useful to explain the remaining wide fraction of negative tests. Nowadays, this gap is problematic since these patients could not benefit from an etiological diagnosis of their disease that allows prognostic trajectories and prenatal/preimplantation diagnosis
Bell’s Inequalities and Entanglement in Corpora of Italian Language
Get PDFWe analyse the results of three information retrieval tests on conceptual combinations that we have recently performed using corpora of Italian language. Each test has the form of a ‘Bell-type test’ and was aimed at identifying ‘quantum entanglement’ in the combination, or composition, of two concepts. In the first two tests, we studied the Italian translation of the combination The Animal Acts, while in the third test, we studied the Italian translation of the combination The Animal eats the Food. We found a significant violation of Bell’s inequalities in all tests. Empirical patterns confirm the results obtained with corpora of English language, which indicates the existence of deep structures in concept formation that are language independent. The systematic violation of Bell’s inequalities suggests the presence of entanglement, and indeed, we elaborate here a ‘quantum model in Hilbert space’ for the collected data. This investigation supports our theoretical hypothesis about entanglement as a phenomenon of ‘contextual updating’, independent of the nature, micro-physical or conceptual-linguistic, of the entities involved. Finally, these findings allow us to further clarify the mutual relationships between entanglement, Cirel’son’s bound, and no-signalling in Bell-type situations
[Recensione a:] Madeleine MONETTE, L’Amérique est aussi un roman québécois. Vues de l’intérieur, Montréal, Nota bene, 2022, 250 pp.
No full textL’ouvrage se veut un recueil d’essais, de fragments, de témoignages, de discours et d’entretiens que l’écrivaine montréalaise vivant à New York Madeleine Monette a conçus, écrits ou livrés au fil des années
Diagnostic Accuracy of Polarized and Ultraviolet Fluorescence-Induced Dermoscopy in Scarring and Nonscarring Alopecias: a Retrospective Observational Multicentric Study
Get PDFIntroduction: There is growing evidence that ultraviolet-induced fluorescence (UVF) dermoscopy may improve diagnostic accuracy in non-neoplastic dermatoses, yet data on hair disorders are scarce. The aim of this observational retrospective study was to compare the accuracy of polarized dermoscopy and UVF-dermoscopy in characterizing and distinguishing scarring and nonscarring alopecias. Methods: A total of 84 patients were enrolled, with 43 and 41 patients suffering from nonscarring and scarring alopecias, respectively. Analyzed variables included scarring findings (i.e., dotted/globular, structureless or perifollicular bright white areas on both polarized and UVF-dermoscopy) and follicular unit (i.e., hair or follicular ostia, with the latter appearing as empty follicular openings and follicular red/blue fluoresce on polarized and UVF-dermoscopy, respectively). Comparative analysis between polarized and UVF-dermoscopy in detecting the abovementioned features and differentiating scarring from nonscarring alopecias were performed, also assessing possible differences according to the skin tone. Interobserver agreement was evaluated for both dermoscopic settings. Results: UVF-dermoscopy was superior (p < 0.01) to polarized dermoscopy in detecting follicular ostia and white bright areas in general and fair-skinned patients, while only follicular ostia were better seen under this setting in skin of color. Additionally, UVF-dermoscopy was found to be more accurate (p < 0.01) in differentiating nonscarring from scarring alopecias when considering all and light phototypes. Finally, Kappa values were 0.57 and 0.83 for polarized and UVF-dermoscopy, respectively. Conclusions: UVF-dermoscopy may be a valuable and reliable complementary tool in differentiating scarring and nonscarring alopecias, especially in light phototypes