60 research outputs found
Constrained reconstruction of 3D curves and surfaces using integral spline operators
In the context of direct/reverse engineering processes one of the main problem is the reconstruction of curves and surfaces starting from a cloud of points. Most of the times the (re)constructed curves and surfaces have to satisfy some particular geometric constraints and functional properties related to the desired shapes. In this paper, referring to 3D curves and surfaces, we propose an algorithm based on an interpolatory variation diminishing integral spline operator characterized by the presence of shape parameters. In order to choose the best value for the shape parameters different functionals can be adopted. Some test cases are presented in order to show the effectiveness of the proposed algorithm: both academic and real world test cases are considered
Age at Onset Influences Progression of Motor and Non-Motor Symptoms during the Early Stage of Parkinson’s Disease: A Monocentric Retrospective Study
The interactions between the age at onset with other pathogenic mechanisms and the interplays between the disease progression and the aging processes in Parkinson’s disease (PD) remain undefined, particularly during the first years of illness. Here, we retrospectively investigated the clinical presentation and evolution of the motor and non-motor symptoms and treatment-related complications during the first 5 years of illness in subjects categorized according to age at onset. A total of 131 subjects were divided into “Early-Onset-PD” (EOPD; onset ≤49 years), “Middle-Onset-PD” (MOPD; onset 50–69 years) and “Late-Onset-PD” (LOPD; onset ≥70 years). The T0 visit was set at the time of the clinical diagnosis; the T1 visit was 5 years (±5 months) later. At T0, there were no significant differences in the motor features among the groups. At T1, the LOPD patients displayed a significantly higher frequency of gait disturbances and a higher frequency of postural instability. Moreover, at T1, the LOPD subjects reported a significantly higher frequency of non-motor symptoms; in particular, cardiovascular, cognitive and neuropsychiatric domains. The presented results showed a significantly different progression of motor and non-motor symptoms in the early course of PD according to the age at onset. These findings contribute to the definition of the role of age at onset on disease progression and may be useful for the pharmacological and non-pharmacological management of PD
Fully convolutional neural networks for polyp segmentation in colonoscopy
Colorectal cancer (CRC) is one of the most common and deadliest forms of cancer, accounting for nearly 10% of all forms of cancer in the world. Even though colonoscopy is considered the most effective method for screening and diagnosis, the success of the procedure is highly dependent on the operator skills and level of hand-eye coordination. In this work, we propose to adapt fully convolution neural networks (FCN), to identify and segment polyps in colonoscopy images. We converted three established networks into a fully convolution architecture and fine-tuned their learned representations to the polyp segmentation task. We validate our framework on the 2015 MICCAI polyp detection challenge dataset, surpassing the state-of-the-art in automated polyp detection. Our method obtained high segmentation accuracy and a detection precision and recall of 73.61% and 86.31%, respectively
An Interdisciplinary Approach for the Experimental Assessments of the Seismic Safety of Artworks
Recent seismic events occurred in areas rich of ancient remains and full of cultural and artistic heritage in terms of artworks. Earthquakes may damage buildings, but the vibrations may also induce the uplift and overturning of their content, implying irreparable loss of cultural values. The seismic assessment of objects is usually tackled modelling them as rigid blocks. This paper focuses on statues, which generally present a very complicated geometry, and proposes a general methodology involving different disciplines, for their experimental seismic assessment. The methodology is here applied to the masterpiece of “Paolo Orsi” museum in Syracuse (Italy), that is the “Venere Landolina”. Due to the complexity of statues, traditional techniques cannot be considered reliable for a proper geometry reconstruction; therefore, Terrestrial Laser Scanner (TLS) and Unmanned Aerial System (UAS) technologies are here employed to obtain a highly detailed and complete digital model. Aiming at providing a low-cost scaled physical model of the statue, a wooden specimen has been arranged employing a Computer Numerical Control (CNC) milling machine, cutting off disks from flat panels which are then superimposed and glued, progressively reconstructing the actual geometry of the statue. The specimen, able to approximately reproduce the scaled actual geometry, was then tested on a shaking table with ground motions compatible with those expected for the site where the statue is located. The obtained results are finally correlated with those expected for the real scale statue
preliminary results of principe predictors of resistance to immunotherapy with nivolumab niv study in advanced pretreated non small cell lung cancer apnsclc investigating the role of an immune genomic signature igs including jak2 jak3 pias4 ptpn2 stat3 ifnar2 alterations
n/
Investigating the seismic response of URM walls with irregular opening layout through different modeling approaches
TThe façade and internal walls of unreinforced masonry (URM) buildings often present an
irregular opening layout, due to architectural reasons or modifications to the structure, which
make the expected seismic damage pattern less predictable a priori. Therefore, the
discretization of the walls in structural components is not standardized, conversely to cases
with a regular opening layout for which the available modeling methods are corroborated by
seismic damage surveys reporting recurrent failure patterns. The structural component
discretization is a relevant step for the code-conforming seismic assessment, typically based
on comparing the internal forces and drifts of each component to strength criteria and drift
thresholds. Therefore, the lack of well-established approaches can significantly influence the
assessment. The issue is even more evident when the structural components must be identified
a priori in the modeling stage, namely for equivalent frame models. The applicability of
available methods for discretization of URM walls with irregular opening layout has been
already investigated in literature, but a conclusive judgment requires further studies.
In this context, this paper presents an overview of the preliminary results addressing the
numerical modeling of this type of walls within the framework of the DPC-ReLUIS 2022-2024
project (Subtask 10.3), funded by the Italian Department of Civil Protection. The Subtask
aims to propose consensus-based recommendations for researchers and practitioners which
can contribute to harmonize the use of different modeling approaches. Seven research groups
are involved in the research, adopting different modeling approaches and computer codes,
but similar assumptions and the same analysis method (pushover) are used. The benchmark
URM structure illustrated in the paper is a two-story wall from which four configurations
with increasing irregularity of opening layout were derived. The results of four modeling
approached are presented. Three of them reproduce the mechanical response of masonry at
the material scale by means of FE models implemented in OpenSees, DIANA and Abaqus
software, while the remaining approach describes the mechanical response of masonry at the
macro-element scale in 3DMacro software. Results were compared in terms of capacity
curves, predicted failure mechanisms and evolution of internal forces in piers. The adoption
of consistent assumptions among the different approaches led to an overall agreement of
predictions at both wall and pier scales, particularly in terms of damage pattern with higher
concentration of damage at the ground story. Despite that, differences on the pushover curves
have been highlighted. They are mainly due to some deviations of the internal forces in squat
piers deriving from a complex load flow in these elements.DPC - Dipartimento della Protezione Civile, Presidenza del Consiglio dei Ministri(LA/P/0112/2020
Castiglione di Paludi: nuove ricerche nel sito della città antica
Ricostruzione ed esame critico dell'impianto urbano del sito anonimo di Castiglione di Paludi
Mesoporous Matrices as Hosts for Metal Halide Perovskite Nanocrystals
Several works have recently demonstrated that perovskite nanocrystals can be controllably formed within a variety of porous matrices employing diverse synthetic strategies. By means of the fine tuning of the pore size distribution, the thickness and composition of the walls, the geometry of the void network and its topology, strict control over the structural and morphological parameters of the hosted semiconductor can be achieved, determining its optical absorption and emission properties. Furthermore, porous hosts provide the guest semiconductor with enhanced stability and versatility in terms of processing, which favors its integration in devices. This article provides a comprehensive review of the different approaches proposed, as well as a discussion on the relevance they may have for the development of nanostructured perovskite¿based optoelectronics. A critical assessment of the optical quality of the hybrid perovskite nanomaterials so obtained is presented, as well as an analysis of the fundamental and applied aspects of the nanocrystal¿matrix interaction and a projected prospect of their impact in the fields of artificial lighting and renewable energy
- …