Signal to Noise Studies on Thermographic Data with Fabricated Defects for Defense Structures

There is a growing international interest in thermal inspection systems for asset life assessment and management of defense platforms. The efficacy of flash thermography is generally enhanced by applying image processing algorithms to the observations of raw temperature. Improving the defect signal to noise ratio (SNR) is of primary interest to reduce false calls and allow for easier interpretation of a thermal inspection image. Several factors affecting defect SNR were studied such as data compression and reconstruction using principal component analysis and time window processing

Implémentation d'une méthode d'identification de l'occupation électronique d'une boîte quantique grâce à des techniques d'apprentissage profond

Ce mémoire présente une nouvelle méthode d'identification des lignes de transition sur un diagramme de stabilité, étape cruciale pour l'automatisation d'une boîte quantique dans le régime à un électron. Le programme implémenté est constitué d'un générateur de données expérimentales, et d'un algorithme d'apprentissage s'entraînant à l'aide de ces données. Ce dernier se veut général et indépendant du dispositif mesuré, étant basé uniquement sur la reconnaissance de transitions électroniques sur un diagramme de stabilité préalablement transformé en base deux (0 et 1). Pour ce faire, un simulateur par éléments finis ainsi que diverses fonctions de traitement d'images ont été implémentés afin de créer rapidement la base de données d'entraînement d'un algorithme d'apprentissage identifiant les lignes de transition sur de véritables diagrammes de stabilité. Le rôle de ce programme se veut un module robuste d'identification, pixel à pixel, de diagrammes de stabilité, bénéficiant des avantages de l'apprentissage automatique. Un tel module permet, en plus de générer facilement des données d'entraînement personnalisées et générées de toutes pièces par ordinateur, d'identifier sans perdre de temps supplémentaire l'entièreté des pixels d'un diagramme de stabilité. Le développement de ces outils constitue d'abord une nouvelle expertise dans le groupe du professeur Pioro-Ladrière, lesquels pouvant être directement appliqués aux travaux en cours. De plus, il s'agit de techniques encore jamais utilisées pour la création de données d'entraînement d'algorithme d'apprentissage, ainsi que de toutes nouvelles applications aux réseaux neuronaux, élargissant ainsi le champ d'expertise de ce récent domaine. Ce travail est une avancée importante pour l'automatisation de l'initialisation d'un qubit de spin, rendant robuste et complète l'analyse du signal provenant d'une boîte quantique. Il permettra aussi de faciliter la généralisation à plusieurs boîtes quantiques et d'être indépendant du dispositif utilisé. Les expérimentateurs pourront donc sauver de nombreuses heures de tests visant à déterminer si un dispositif est fonctionnel, et à en trouver le régime d'opération, le cas échéant

Atrial natriuretic factor during atrial fibrillation and supraventricular tachycardia

Plasma immunoreactive atrial natriuretic factor was measured in 10 patients with chronic atrial fibrillation before and after cardioversion to sinus rhythm, and in 14 patients during electrophysiologic evaluation of paroxysmal supraventricular tachycardia. The mean plasma concentration of atrial natriuretic factor in atrial fibrillation was 138 ± 48 pg/ml and decreased to 116 ± 45 pg/ml 1 hour after cardioversion to sinus rhythm (p < 0.005). The mean plasma concentration of atrial natriuretic factor increased from 117 ± 53 pg/ml in sinus rhythm to 251 ± 137 pg/ml during laboratory-induced supraventricular tachycardia (p < 0.005). Right atrial pressures were recorded in 12 patients; the baseline atrial pressure was 4.3 ± 1.9 mm Hg and increased to 7.4 ± 3.6 mm Hg during supraventricular tachycardia (p < 0.005). A modest but significant linear relation was noted between the changes in plasma atrial natriuretic factor and right atrial pressure measurements during induced supraventricular tachycardia (r = 0.60, p < 0.05).In conclusion, changes in atrial rhythm and pressure may be an important factor modulating the release of atrial natriuretic factor in the circulation and raised levels of this hormone may be a contributing factor for the polyuria and the hypotension associated with paroxysmal supraventricular tachyarrhythmias

Comparative study of microlaser excitation thermography and microultrasonic excitation thermography for submillimeter porosity in carbon fiber reinforced polymer composites

Stitching is used to reduce incomplete infusion of T-joint core (dry-core) and reinforce T-joint structure. However, it may cause new types of flaws, especially submillimeter flaws. Thermographic approaches including microvibrothermography, microlaser line thermography, and microlaser spot thermography on the basis of pulsed and lock-in techniques were proposed. These techniques are used to detect the submillimeter porosities in a stitched T-joint carbon fiber reinforced polymer composite specimen. X-ray microcomputed tomography was used to validate the thermographic results. Finally an experimental comparison of microlaser excitation thermography and microultrasonic excitation thermography was conducte

How to reveal subsurface defects in Kevlar® composite materials after an impact loading using infrared vision and optical NDT techniques?

An integrated system between infrared vision and optical non-destructive testing techniques can be considered a viable, robust and reliable approach for both aerospace manufacturing and in-service inspections. In this paper, infrared vision is applied in different spectral bands on two impacted panels made of aramid–phenolic composite by applying two different methods, respectively: (1) near and short-wave infrared reflectography and transmittography, and (2) mid-wave active infrared thermography. Furthermore, optical methods, namely digital speckle photography and holographic interferometry, are used as well to highlight the damages due to the impacts on the samples. Some techniques provide more straightforward detection capabilities than others for different defect types

Clinical practice guideline recommendations to improve the mental health of adult trauma patients:protocol for a systematic review

Introduction Mental disorders are common in adult patients with traumatic injuries. To limit the burden of poor psychological well-being in this population, recognised authorities have issued recommendations through clinical practice guidelines (CPGs). However, the uptake of evidence-based recommendations to improve the mental health of trauma patients has been low until recently. This may be explained by the complexity of optimising mental health practices and interpretating CGPs scope and quality. Our aim is to systematically review CPG mental health recommendations in the context of trauma care and appraise their quality. Methods and analysis We will identify CPG through a search strategy applied to Medline, Embase, CINAHL, PsycINFO and Web of Science databases, as well as guidelines repositories and websites of trauma associations. We will target CPGs on adult and acute trauma populations including at least one recommendation on any prevention, screening, assessment, intervention, patient and family engagement, referral or follow-up procedure related to mental health endorsed by recognised organisations in high-income countries. No language limitations will be applied, and we will limit the search to the last 15 years. Pairs of reviewers will independently screen titles, abstracts, full texts, and carry out data extraction and quality assessment of CPGs using the Appraisal of Guidelines Research and Evaluation (AGREE) II. We will synthesise the evidence on recommendations for CPGs rated as moderate or high quality using a matrix based on the Grading of Recommendations Assessment, Development and Evaluation quality of evidence, strength of recommendation, health and social determinants and whether recommendations were made using a population-based approach. Ethics and dissemination Ethics approval is not required, as we will conduct secondary analysis of published data. The results will be disseminated in a peer-reviewed journal, at international and national scientific meetings. Accessible summary will be distributed to interested parties through professional, healthcare quality and persons with lived experience associations.</p

Drone-based non-destructive inspection of industrial sites: a review and case studies

Using aerial platforms for Non-Destructive Inspection (NDI) of large and complex structures is a growing field of interest in various industries. Infrastructures such as: buildings, bridges, oil and gas, etc. refineries require regular and extensive inspections. The inspection reports are used to plan and perform required maintenance, ensuring their structural health and the safety of the workers. However, performing these inspections can be challenging due to the size of the facility, the lack of easy access, the health risks for the inspectors, or several other reasons, which has convinced companies to invest more in drones as an alternative solution to overcome these challenges. The autonomous nature of drones can assist companies in reducing inspection time and cost. Moreover, the employment of drones can lower the number of required personnel for inspection and can increase personnel safety. Finally, drones can provide a safe and reliable solution for inspecting hard-to-reach or hazardous areas. Despite the recent developments in drone-based NDI to reliably detect defects, several limitations and challenges still need to be addressed. In this paper, a brief review of the history of unmanned aerial vehicles, along with a comprehensive review of studies focused on UAV-based NDI of industrial and commercial facilities, are provided. Moreover, the benefits of using drones in inspections as an alternative to conventional methods are discussed, along with the challenges and open problems of employing drones in industrial inspections, are explored. Finally, some of our case studies conducted in different industrial fields in the field of Non-Destructive Inspection are presented

Le FORUM, Vol. 37 No. 2

https://digitalcommons.library.umaine.edu/francoamericain_forum/1037/thumbnail.jp