Due to the uncertainty of material properties of plate-like structures, many traditional methods are unable to locate the impact source on their surface in real time. It is important to study the impact source-localization problem for plate structures. In this paper, a data-driven machine learning method is proposed to detect impact sources in plate-like structures and its effectiveness is tested on three plate-like structures with different material properties. In order to collect data on the localization of the impact source, four piezoelectric transducers and an oscilloscope were utilized to construct an experimental platform for impulse response testing. Meanwhile, the position of the impact source on the surface of the test plate is generated by manually releasing the steel ball. The eigenvalue of arrival time in the time domain signal is extracted to build data sets for machine learning. This paper uses the Back Propagation (BP) neural network to learn the difference in the arrival time of each sensor and predict the location of the impact source. The results demonstrate that the machine learning method proposed in this paper can predict the location of the impact source in the plate-like structure without relying on the material properties, with high test accuracy and robustness. The research work in this paper can provide experimental methods and testing techniques for locating impact damage in composite material structures.
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http://dx.doi.org/10.3390/ma18020449 | DOI Listing |
J Infect Dev Ctries
December 2024
Infectious Diseases Research Group, School of Medicine, Universidad Nacional de Colombia (National University of Colombia), Bogotá, Colombia.
Introduction: Coronavirus disease 2019 (COVID-19) is a life-threatening disease that was declared a pandemic in March 2020. Organ transplant recipients are vulnerable to infection and complications from COVID-19. The objective of this study was to investigate the rates of infection, mortality, and case-fatality ratios (CFR) in solid organ transplant recipients and patients on the waiting list for organ allocation in the period prior to the availability of specific vaccines.
View Article and Find Full Text PDFMol Ther
January 2025
Brown Center for Immunotherapy. Indiana University School of Medicine. 975 W. Walnut St., IB554A, Indianapolis, IN 46202. Electronic address:
Chimeric Antigen Receptor (CAR) T cell therapy has revolutionized cancer treatment and is now being explored for other diseases, such as autoimmune disorders. While the tumor microenvironment (TME) in cancer is often immunosuppressive, in autoimmune diseases, the environment is typically inflammatory. Both environments can negatively impact CAR T cell survival: the former through direct suppression, hypoxia, and nutrient deprivation, and the latter through chronic T cell receptor (TCR) engagement, risking exhaustion.
View Article and Find Full Text PDFBiol Res
January 2025
Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Tabriz, Iran.
Fluoride (F), as a natural element found in a wide range of sources such as water and certain foods, has been proven to be beneficial in preventing dental caries, but concerns have been raised regarding its potential deleterious effects on overall health. Sodium fluoride (NaF), another form of F, has the ability to accumulate in reproductive organs and interfere with hormonal regulation and oxidative stress pathways, contributing to reproductive toxicity. While the exact mechanisms of F-induced reproductive toxicity are not fully understood, this review aims to elucidate the mechanisms involved in testicular and ovarian injury.
View Article and Find Full Text PDFNat Commun
January 2025
Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany.
The evolutionary impact of epigenetic variation depends on its transgenerational stability and source - whether genetically determined, environmentally induced, or due to spontaneous, genotype-independent mutations. Here, we evaluate current approaches for investigating an independent role of epigenetics in evolution, pinpointing methodological challenges. We further identify opportunities arising from integrating epigenetic data with population genetic analyses in natural populations.
View Article and Find Full Text PDFBMJ Open
January 2025
Department of Public Health, Policy and Systems, University of Liverpool, Liverpool, UK.
Objectives: How are socioeconomic inequalities modified by, or how do they interact with, preterm birth?
Design: Narrative systematic review of quantitative observational studies of an interaction, or effect modification, between preterm birth and socioeconomic status.
Data Sources: Five databases were searched for studies published between January 2000 and June 2020. Title and abstract were reviewed to identify articles for dual screening.
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