Monitoring of architectural heritage with machine learning methods

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Effect of noise in the time-frequency estimate of the peridynamic bond elastic constant parameter

The Peridynamic (PD) theory is a modern nonlocal (nonlinear, elastic /inelastic, with-out/with memory) theory able to deal with long-range forces and discontinuity in materials. For this reason the theory is suitable for the monitoring of masonry structures. Starting from a special case of PD formulation, named Bond-Based Peridynamic (BBPD), a feature ob-tained by the idealization of real systems with BBPD is used for SHM purposes: the bond elastic constant parameter. To characterize the damage (i.e. permanent deterioration of ma-terial and/or geometric properties of the systems) occurring in systems idealized with PD models, a joint time-frequency direct estimate of the parameter values is performed using a Short Time Fourier Transform (STFF) of the systems response and the input acceleration at the base of the systems. The method is applied numerically and the effect of noise in the time-frequency evaluation of the parameter values is analyzed. The study concludes that PD can provides simply and strong information on the health of simulated systems, allowing at the same time an easy and scalable parametrization of civil, especially masonry, structures, while the bond elastic constant parameter can be used for the damage characterization, i.e. to detect, quantify and localize the damage in a generic system

Combining satellite geophysical data with continuous on-site measurements for monitoring the dynamic parameters of civil structures

One key issue in the Structural Health Monitoring (SHM) of buildings is the influence of the soil on the dynamics of the system. The lack of accurate information on soil-structure interaction represents a source of significant uncertainty and generates difficulties in assessing the state of structural health. In this respect, satellite data could represent a valuable tool for soil knowledge. This paper presents the first study of satellite data coming from the environmental Copernicus program of the European Space Agency (ESA) for the alternative application in the field of SHM. In particular, Land Surface Temperature (LST) and Soil Water Index (SWI) data are elected to study surface temperature and moisture condition of the soil. Once examined and processed, these records have been statistically analyzed, crossed with on-site experimental quantities (natural frequencies and environmental variations), and given as input to a Finite Element (FE) model. The final goal is to understand the actual structural behavior, but also to monitor the evolution of the dynamic parameters for the purposes of structural and seismic monitoring. The largest oval masonry dome in the world was chosen as a prominent case study to demonstrate this novel approach to SHM

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

Reply to Lanari, R., et al. comment on “pre-collapse space geodetic observations of critical infrastructure: The morandi bridge, Genoa, Italy” by Milillo et al. (2019)

We would like to thank our colleagues for their comment, as we believe that this discussion further highlights the importance of innovative research in the emerging field of InSAR applications to civil engineering structures. We discuss the statement from Lanari et al. (2020): “Our analysis shows that, although both the SBAS and the TomoSAR analyses allow achieving denser coherent pixel maps relevant to the Morandi bridge, nothing of the pre-collapse large displacements reported in Milillo et al. (2019) appears in our results”. In this reply we argue that (1) they cannot detect the pre-collapse movements because they use standard approaches and (2) the signals of interest become observable by changing the point of view.</p

Sensitivity Analysis of the Environmental Effect on the Dynamics of Concrete Historical Architectures with Structural Joints

A large part of the 20th century architectural heritage is approaching the end of its useful service life and issues related to its conservation should be therefore addressed. In that period, the use of concrete as a building material spread considerably, favoring experimentation in geometries and structural schemes. If on one hand the innovativeness and uniqueness of these buildings have made them an essential part of our architectural heritage, on the other hand they make their study challenging. The complexity of these structures' dynamic behavior results in the uncertainty on the sensitivity to possible damage scenarios and environmental factors, which represent a relevant aspect in Structural Health Monitoring (SHM). This paper reports the results of a sensitivity analysis of changing environmental conditions on a concrete historical building, composed by blocks divided by structural joints. The case study is the Pavilion V of Turin Exhibition Center, built by Riccardo Morandi in the late 50s. The research conducted on the pavilion's Finite Element Model (FEM) allowed to show the effects of the variation of the elastic modulus of the structure's components on the modal parameters for different temperature sensitivity scenarios and, consequently, to extract useful information for an upcoming permanent monitoring

Pre-Collapse Space Geodetic Observations of Critical Infrastructure: The Morandi Bridge, Genoa, Italy

We present a methodology for the assessment of possible pre-failure bridge deformations, based on Synthetic Aperture Radar (SAR) observations. We apply this methodology to obtain a detailed 15-year survey of the Morandi bridge (Polcevera Viaduct) in the form of relative displacements across the structure prior to its collapse on August 14th 2018. We generated a displacement map for the structure from space-based SAR measurements acquired by the Italian constellation COSMO-SkyMed and the European constellation Sentinel-1A/B over the period 2009&ndash;2018. Historical satellite datasets include Envisat data spanning 2003&ndash;2011. The map reveals that the bridge was undergoing an increased magnitude of deformations over time prior to its collapse. This technique shows that the deck next to the collapsed pier was characterized since 2015 by increasing relative displacements. The COSMO-SkyMed dataset reveals the increased deformation magnitude over time of several points located near the strands of this deck between 12th March 2017 and August 2018

Reply to Lanari, R., et al. comment on “pre-collapse space geodetic observations of critical infrastructure: The morandi bridge, Genoa, Italy” by Milillo et al. (2019)

We would like to thank our colleagues for their comment, as we believe that this discussion further highlights the importance of innovative research in the emerging field of InSAR applications to civil engineering structures. We discuss the statement from Lanari et al. (2020): “Our analysis shows that, although both the SBAS and the TomoSAR analyses allow achieving denser coherent pixel maps relevant to the Morandi bridge, nothing of the pre-collapse large displacements reported in Milillo et al. (2019) appears in our results”. In this reply we argue that (1) they cannot detect the pre-collapse movements because they use standard approaches and (2) the signals of interest become observable by changing the point of view.Geo-engineerin

Morphological and immunophenotypical changes of human bone marrow adipocytes in marrow metastasis and myelofibrosis

The bone marrow adipose tissue constitutes more than two-thirds of the bone marrow volume in adult life and is known to have unique metabolic and functional properties. In neoplastic disorders, bone marrow adipocytes (BMAds) contribute to create a favorable microenvironment to survival and proliferation of cancer cells. Many studies explored the molecular crosstalk between BMAds and neoplastic cells, predominantly in ex-vivo experimental systems or in animal models. However, little is known on the features of BMAds in the human neoplastic marrow. The aim of our study was to analyze the in situ changes in morphology and immunophenotype of BMAds in two different types of neoplastic marrow conditions. We selected a series of archival iliac crest and vertebral bone biopsies from patients with bone marrow metastasis (MET), patients with myeloproliferative neoplasia with grade-3 myelofibrosis (MPN-MF) and age-matched controls (CTR). We observed a significant reduction in the number of BMAds in MET and MPN-MF compared to CTR. Accordingly, in the same groups, we also detected a significant reduction in the mean cell diameter and area. Immunolocalization of different adipocyte markers showed that, compared to CTR, in both MET and MPN-MF the percentages of adiponectin- and phosphorylated hormone sensitive lipase-positive BMAds were significantly reduced and increased respectively. No statistically significant difference was found between MET and MPN-MF. Interestingly, in one MET sample, “remodeled” BMAds containing a large lipid vacuole and multiple, smaller and polarized lipid droplets were identified. In conclusion, our data show that in different types of marrow cancers, BMAds undergo significant quantitative and qualitative changes, which need to be further investigated in future studies