64 research outputs found
Low-cost and distributed health monitoring system for critical buildings
In this paper we present a low-cost distributed embedded system for Structural Health Monitoring (SHM) that uses very cost-effective MEMS accelerometers, instead of more expensive piezoelectric analog transducers. The proposed platform provides online filtering and fusion of the collected data directly on-board. Data are transmitted after processing using a WiFi transceiver. Low-cost and synchronized devices permit to have more fine-grained measurements and a comprehensive assessment of the whole building, by evaluating their response to vibrations. The challenge addressed in this paper is to execute a quite computationally-demanding digital filtering on a low-cost microcontroller STM32, and to reduce the signal-to-noise ratio typical of MEMS devices with a spatial redundancy of the sensors. Our work poses the basis for low-cost methods for elaborating complex modal analysis of buildings and structures
IDENTIFICAZIONE SIMULTANEA DI PARAMETRI IN SISTEMI LINEARI
Studio di un sistema per l’identificazione simultanea di parametri in sistemi lineari.
I controllori Proporzionali-integrali-derivativi (PID) continuano ad essere ampiamente impiegati nei processi industriali per la loro semplicità e robustezza. Nel caso di processi di ordine basso (primo, secondo, terzo con ritardo) la tecnica classica per la sincronizzazione dei parametri del regolatore si basa sulle regole di Ziegler – Nichols nella loro forma originale o secondo le numerose varianti proposte. Esistono inoltre altre tecniche ( ATV – SATV ) con le quali è possibile individuare alcuni parametri caratteristici di un processo assegnato. Queste tecniche però sono in grado di poter stimare solamente un criterio alla volta. In questa tesi viene illustrata una tecnica automatica con la quale, utilizzando l’algoritmo di Fast Fourier Trasform, si riescono ad individuare alcuni parametri caratteristici di un procedimento dinamico assegnato ( margine di ampiezza, margine di fase, sensibilità e banda passante a ciclo chiuso) in modo rapido e simultaneo. La validità della tecnica adottata è dimostrata mediante simulazioni.
Study of simultaneous identification system of typical parameters of linear processes.
Proportional-integrative-derivative controllers (PID) still are the most used controllers in industrial processes due to their simplicity and robustness. For low order’s processes (first, second, third with delay process) the classic method of regulator’s parameters tuning is the method of Ziegler – Nichols and other methods based on his hypotheses. There are also others techniques ( ATV – SATV ) witch can identify some typical parameters of an assigned process. The limitation of these techniques is that can only identify one parameter at a time. This graduation thesis faces the problem of an automatic and simultaneous identification, of multiple typical parameters (Gain margin, Phase margin, sensitivity in a closed loop) of a dynamic process utilizing the Fast Fourier Transform. The validity of this technique is verified with simulations
Cluster-based Vibration Analysis of Structures with GSP
This article describes a divide-and-conquer strategy suited for vibration monitoring applications. Based on a low-cost embedded network of microelectromechanical accelerometers, the proposed architecture strives to reduce both power consumption and computational resources. Moreover, it eases the sensor deployment on large structures by exploiting a novel clustering scheme, which
consists of unconventional and nonoverlapped sensing configurations. Signal processing techniques for inter- and intracluster data assembly are introduced to allow for a fullscale assessment of the structural integrity. More specifically, the capability of graph signal processing is adopted for the first time in vibration-based monitoring scenarios to capture the spatial relationship between acceleration data. The experimental validation, conducted on a steel beam perturbed with additive mass, reveals high accuracy in damage detection tasks. Deviations in spectral content and mode shape envelopes are correctly revealed regardless of environmental factors and operational uncertainties. Furthermore, an additional key advantage of the implemented architecture relies on its compliance with blind modal investigations, an approach that favors the implementation of autonomous smart monitoring systems
Author Correction: 3D measurement techniques for the hindfoot alignment angle from weight-bearing CT in a clinical population
Cone-beam CT (CBCT) scans now enable accurate measurements on foot skeletal structures with
the advantage of observing these in 3D and in weight-bearing. Among the most common skeletal
deformities, the varus/valgus of the hindfoot is the most complex to be represented, and a number
of measure proposals have been published. This study aims to analyze and to compare these
measurements from CBCT scans in a real clinical population with large such deformity. Ten patients
with severe acquired adult fatfoot and indication for surgery underwent CBCT scans (Carestream,
USA) while standing on that leg, before and after surgical correction. Corresponding 3D shape of each
bone of the distal shank and hindfoot were defned (Materialise, Belgium). Six diferent techniques
from the literature were used to calculate the varus/valgus deformity, i.e. the inclination of the
hindfoot in the frontal plane of the shank. Standard clinical measurements by goniometers were taken
for comparison. According to these techniques, and starting from a careful 3D reconstruction of the
relevant foot skeletal structures, a large spectrum of measurements was found to represent the same
hindfoot alignment angle. Most of them were very diferent from the traditional clinical measures. The
assessment of the pre-operative valgus deformity and of the corresponding post-operative correction
varied considerably. CBCT fnally allows 3D assessment of foot deformities in weight-bearing.
Measurements from the diferent available techniques do not compare well, as they are based on
very diferent approaches. It is recommended to be aware of the anatomical and functional concepts
behind these techniques before clinical and surgical conclusions
A scoping review of scientific concepts concerning motor recovery after stroke as employed in clinical trials
The scientific literature on poststroke rehabilitation is remarkably vast. Over the last decades, dozens of rehabilitation approaches have been investigated. However, sometimes it is challenging to trace new experimental interventions back to some of the known models of motor control and sensorimotor learning. This scoping review aimed to investigate motor control models' diffusion among the literature on motor recovery after stroke. We performed a literature search on Medline, Cochrane, Web of Science, Embase, and Scopus databases. The last search was conducted in September 2023. This scoping review included full-text articles published in English in peer-reviewed journals that provided rehabilitation interventions based on motor control or motor learning frameworks for at least one individual with stroke. For each study, we identified the theoretical framework the authors used to design the experimental treatment. To this aim, we used a previously proposed classification of the known models of motor control, dividing them into the following categories: neuroanatomy, robotics, self-organization, and ecological context. In total, 2,185 studies were originally considered in this scoping review. After the screening process, we included and analyzed 45 studies: 20 studies were randomized controlled trials, 12 were case series, 4 were case reports, 8 were observational longitudinal pilot studies, and 1 was an uncontrolled trial. Only 10 studies explicitly declared the reference theoretical model. Considering their classification, 21 studies referred to the robotics motor control model, 12 to the self-organization model, 8 to the neuroanatomy model, and 4 to the ecological model. Our results showed that most of the rehabilitative interventions purposed in stroke rehabilitation have no clear theoretical bases on motor control and motor learning models. We suggest this is an issue that deserves attention when designing new experimental interventions in stroke rehabilitation
Carbon Fiber-Reinforced PolyEtherEtherKetone (CFR-PEEK) Instrumentation in Degenerative Disease of Lumbar Spine: A Pilot Study
: CFR-PEEK is gaining popularity in spinal oncological applications due to its reduction of imaging artifacts and radiation scattering compared with titanium, which allows for better oncological follow-up and efficacy of radiotherapy. We evaluated the use of these materials for the treatment of lumbar degenerative diseases (DDs) and considered the biomechanical potential of the carbon fiber in relation to its modulus of elasticity being similar to that of bone. Twenty-eight patients with DDs were treated using CRF-PEEK instrumentation. The clinical and radiographic outcomes were collected at a 12-month FU. Spinal fusion was evaluated in the CT scans using Brantigan scores, while the clinical outcomes were evaluated using VAS, SF-12, and EQ-5D scores. Out of the patients evaluated at the 12-month FU, 89% showed complete or almost certain fusion (Brantigan score D and E) and presented a significant improvement in all clinical parameters; the patients also presented VAS scores ranging from 6.81 ± 2.01 to 0.85 ± 1.32, EQ-5D scores ranging from 53.4 ± 19.3 to 85.0 ± 13.7, SF-12 physical component scores (PCSs) ranging from 29.35 ± 7.04 to 51.36 ± 9.75, and SF-12 mental component scores (MCSs) ranging from 39.89 ± 11.70 to 53.24 ± 9.24. No mechanical complications related to the implant were detected, and the patients reported a better tolerance of the instrumentation compared with titanium. No other series of patients affected by DD that was stabilized using carbon fiber implants have been reported in the literature. The results of this pilot study indicate the efficacy and safety of these implants and support their use also for spinal degenerative diseases
Genetic Testing and Counselling in Hypertrophic Cardiomyopathy: Frequently Asked Questions
Genetic counselling and genetic testing in hypertrophic cardiomyopathy (HCM) represent an integral part of the diagnostic algorithm to confirm the diagnosis, distinguish it from phenocopies, and suggest tailored therapeutic intervention strategies. Additionally, they enable cascade genetic testing in the family. With the implementation of Next Generation Sequencing technologies (NGS), the interpretation of genetic data has become more complex. In this regard, cardiologists play a central role, aiding geneticists to correctly evaluate the pathogenicity of the identified genetic alterations. In the ideal setting, geneticists and cardiologists must work side by side to diagnose HCM as well as convey the correct information to patients in response to their many questions and concerns. After a brief overview of the role of genetics in the diagnosis of HCM, we present and discuss the frequently asked questions by HCM patients throughout our 20-year genetic counselling experience. Appropriate communication between the team and the families is key to the goal of delivering the full potential of genetic testing to our patients
SARS-CoV-2 vaccination modelling for safe surgery to save lives: Data from an international prospective cohort study
Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population
bioNMF: a versatile tool for non-negative matrix factorization in biology
BACKGROUND: In the Bioinformatics field, a great deal of interest has been given to Non-negative matrix factorization technique (NMF), due to its capability of providing new insights and relevant information about the complex latent relationships in experimental data sets. This method, and some of its variants, has been successfully applied to gene expression, sequence analysis, functional characterization of genes and text mining. Even if the interest on this technique by the bioinformatics community has been increased during the last few years, there are not many available simple standalone tools to specifically perform these types of data analysis in an integrated environment. RESULTS: In this work we propose a versatile and user-friendly tool that implements the NMF methodology in different analysis contexts to support some of the most important reported applications of this new methodology. This includes clustering and biclustering gene expression data, protein sequence analysis, text mining of biomedical literature and sample classification using gene expression. The tool, which is named bioNMF, also contains a user-friendly graphical interface to explore results in an interactive manner and facilitate in this way the exploratory data analysis process. CONCLUSION: bioNMF is a standalone versatile application which does not require any special installation or libraries. It can be used for most of the multiple applications proposed in the bioinformatics field or to support new research using this method. This tool is publicly available at
Results from the kaonic hydrogen X-ray measurement at DAFNE and outlook to future experiments
The system at rest plays a key role for the understanding of strong interaction of hadrons with strangeness involved. The experiment SIDDHARTA used X-ray spectroscopy of kaonic atoms to measure the strong interaction induced shift and width of the ground state. It was the first experiment on kaonic He3 and deuterium ever, kaonic hydrogen was measured with improved precision resulting in \epsilon_{1s} = -283 \pm 36 \mbox{(stat)} \pm 6 \mbox{(syst)} eV and \Gamma_{1s} = 541 \pm 89 \mbox{(stat)} \pm 22 \mbox{(syst)} eV. Additionally a scheme for an improved future experiment on kaonic deuterium is introduced in this contribution
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